|Publication number||US6121600 A|
|Application number||US 08/901,423|
|Publication date||Sep 19, 2000|
|Filing date||Jul 28, 1997|
|Priority date||Jul 28, 1997|
|Also published as||EP1015848A1, EP1015848A4, WO1999005473A1|
|Publication number||08901423, 901423, US 6121600 A, US 6121600A, US-A-6121600, US6121600 A, US6121600A|
|Inventors||Michael R. Saldana, Rodney Lynn Doster, Roland M. Morley, Joseph Paul Estrera|
|Original Assignee||Litton Systems, Inc.|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (9), Referenced by (13), Classifications (17), Legal Events (7)|
|External Links: USPTO, USPTO Assignment, Espacenet|
The subject matter of this application is technically related to the subject matter of U.S. patent application Ser. No. 08/901,419, filed Jul. 28, 1997, which has the same inventor and is assigned to the same assignee as this application, and the disclosure of which is incorporated herein by reference to the extent necessary for a complete and enabling disclosure of the present invention.
The present invention is generally in the field of night vision devices of the light amplification type. More particularly, the present invention relates to an improved night vision device having an image intensifier tube (I2 T). Also, the present invention is in the field of laser range finders. A method of operating the device and a method of laser range finding (LRF) are disclosed also.
Laser range finders have been known for a considerable time. These devices are used, for example, by surveyors to calculate the distance from a point of observation to an object such as a geological formation in the field of view. Generally, a laser range finder operates by projecting a pulse of laser light at an object. The laser light illuminates the object, and a portion of the laser light is reflected back toward the laser range finder device. The reflected laser light is detected, and the time interval required for the laser light pulse to travel to and from the object is measured. From this time interval measurement and the known speed of light, the distance between the laser range finder and the object is calculated.
Such a conventional laser range finder includes a laser capable of producing laser light pulses of high peak power and very short duration (i.e., less than 50 ns duration). The detector for the reflected laser light may include a high speed photodetector (such as an InGaAs avalanche photodiode), which is coupled to a high gain, high speed amplifier. A high speed digital counter is used as a timer to determine the time interval required for the laser light to travel to the object and for laser light reflecting off of the object to travel back to the device. From this time interval information an internal electronic calculator determines the range to the object, and this range is presented to the user of the device, usually on a visual display screen.
These conventional laser range finders have a disadvantage of a considerable cost and complexity. The laser pulses must be of considerable intensity as well, which requires a high power laser. The conventional laser range finders are subject to optical and electrical problems, such as vulnerability to electromagnetic interference, damage to electrical components and damage to optical components. Reliability of the devices is also adversely impacted by their complexity.
On the other hand, conventional night vision devices of the image intensification type (i.e., light amplification) type have also been known for a considerable time. Generally, these night vision devices include an objective lens which focuses invisible infrared light from the night time scene onto the transparent light-receiving face of an image intensifier tube. At its opposite image-face, the image intensifier tube provides an image in visible yellow-green phosphorescent light, which is then presented to a user of the device via an eye piece lens.
Even on a night which is too dark for diurnal vision, invisible infrared light is richly provided by the stars. Human vision can not utilize this infrared light from the stars because the so-called near-infrared portion of the spectrum is invisible for humans. A night vision device of the light amplification type can provide a visible image replicating the night time scene.
A contemporary night vision device will generally use an image intensifier tube with a photocathode behind the light-receiving face of the tube. The photocathode is responsive to photons of infrared light to liberate photoelectrons. These photoelectrons are moved by a prevailing electrostatic field to a microchannel plate (MCP) having a great multitude of dynodes, or microchannels with an interior surface substantially defined by a material having a high coefficient of secondary electron emissivity. The photoelectrons entering the microchannels cause a cascade of secondary emission electrons to move along the microchannels so that a spatial output pattern of electrons which replicates an input pattern, and at a considerably higher electron density than the input pattern results. This pattern of electrons is moved from the microchannel plate to a phosphorescent screen to produce a visible image. A power supply for the image intensifier tube provides the electrostatic field potentials referred to above, and also provides a field and current flow to the microchannel plate.
Conventional night vision devices (i.e., since the 1970's and to the present day) provide automatic brightness control (ABC), and bright-source protection (BSP). The former function maintains the brightness of the image provided to the user substantially constant despite changes in the brightness (in infrared and the near-infrared portion of the spectrum) of the scene being viewed. BSP prevents the image intensifier tube from being damaged by an excessively high current level in the event that a bright source, such as a flare or fire, comes into the field of view.
The ABC function is conventionally accomplished by providing a regulator circuit monitoring the output current from the phosphorescent screen. When this current exceeds a certain threshold, the field voltage level across the opposite faces of the microchannel plate is decreased to reduce its gain. In other words, for each photoelectron entering a channel of the microchannel plate, the number of secondary-emission electrons exiting this microchannel will be a function of the applied voltage differential across the microchannel plate (as well as the so-called "strip current" of this plate) within a certain range for the operation of the microchannel plate. Reducing the applied voltage differential across a microchannel plate decreases both the number of secondary-emission electrons produced and the strip current of the microchannel plate.
Unfortunately, this reduction in microchannel plate voltage also has the effect of reducing the resolution of the image intensifier tube. That is, the gain versus voltage function of the image intensifier tube at lowered voltages results in a matrix pattern from the microchannel plate appearing in the image. This matrix pattern is sometimes referred to as fixed-pattern noise in the image. As a result, in bright-field conditions with the ABC feature of the conventional night vision device operating the conventional night vision device may drastically lose resolution so that the user of the device is no longer able to discern details of the viewed scene which would be discernable were they viewed under darker field conditions in which ABC function were not applying.
A bright-source protection is provided in conventional night vision devices by decreasing the electrostatic field voltage provided to the photocathode. A BSP function results because the high impedance of the photocathode in combination with a circuit element of high resistance value in series with the photocathode creates a greater voltage drop under the higher current conditions caused by a large number of photons incident on the photocathode when a bright source is present in the viewed field (i.e., with a resulting high number of photoelectrons being provided by the photocathode). The photoelectrons provided by the photocathode represent a current flow increasing in magnitude with increasing light levels in the viewed field, such that the impedance of the photocathode causes an inherent decrease in the voltage level effective at the photocathode to move these electrons to the microchannel plate.
This conventional method of BSP also has the disadvantage of decreasing resolution for the image intensifier tube. The reduced electrostatic field between the photocathode and the microchannel plate input when the BSP function is operational causes a reduced resolution for the tube. That is, photoelectrons liberated within the photocathode are not moved to the microchannel plate as effectively when the field voltage for the photocathode is reduced, and may not reach the microchannel plate at all. This is the case because photoelectrons within the photocathode must overcome a surface potential barrier in order to escape the photocathode and move to the microchannel plate. In order to be liberated into free space and be moved by the prevailing electrostatic field to the input of the microchannel plate, photoelectrons must have a certain effective energy level. As the voltage applied to the photocathode decreases, considered statistically, some photoelectrons will not be able to overcome this surface potential barrier and will not be liberated into free space. The image information represented by these photoelectrons trapped within the photocathode will be lost from the image provided to the user of the night vision device.
Conventional night vision devices which are usable to sight a weapon are found in U.S. Pat. Nos. 5,084,780; and 5,035,472. Neither of these patents is believed to suggest or disclose a night vision device which is combined with a laser range finder using the image intensifier tube of the night vision device as a detector for laser light in the laser range finder.
In view of the deficiencies of the conventional related technology, it would be desirable to provide a single device which provides both night vision imaging and laser range finding functions.
Additionally, it would be desirable to provide a laser range finder which uses an image intensifier tube as a detector for reflected laser light from an object.
Yet another advantage would be to provide such a device which allows both night-time and day-time imaging and laser range finding using the image intensifier tube of the imaging device as the detector for reflected laser light.
Still another advantage could be obtained by provision of such a device which allows both night-time and day-time imaging and laser range finding using the image intensifier tube of the imaging device as the detector for reflected laser light, and which provides improved automatic brightness control and improved bright-source protection functions while avoiding the decrease in photocathode and microchannel plate voltages which conventional night vision devices utilize for these ABC and BSP functions.
Accordingly it is an object for this invention to provide a method of laser range finding using an image intensifier tube as a detector for reflected laser light.
An advantage of the present combined night vision device and laser range finder is that a single device is provided of considerably less expense and of considerably improved durability in comparison to the conventional technology providing these functions in two separate devices. The laser pulses needed for laser range finding can be of lower power than those required by a conventional laser range finder. This further decreases the cost of the device because of the lower cost of a lower power laser, and the energy user of the device is also decreased.
Other objects, features, and advantages of the present invention will be apparent to those skilled in the art from a consideration of the following detailed description of a preferred exemplary embodiment thereof taken in conjunction with the associated figures which will first be described briefly.
FIG. 1 is a schematic representation of an integrated night vision device and laser range finder embodying the present invention, and with a part of this device shown in alternative operative positions by use of solid and dashed lines;
FIG. 2 shows a typical image intensifier tube in longitudinal cross section;
FIG. 3 is a schematic representation of a power supply and laser range finder operation circuit for an integrated night vision device and laser range finder embodying the present invention; and
FIGS. 4 and 5 respectively provide graphical illustrations of an automatic brightness control (ABC) function, and of a bright-source protection (BSP) function of the integrated night vision device and laser range finder embodying the present invention.
While the present invention may be embodied in many different forms, disclosed herein is a specific exemplary embodiment that illustrates and explains the principles of the invention. It should be emphasized that the present invention is not limited to the specific embodiment illustrated.
Referring first to FIG. 1, there is shown schematically the basic elements of one version of an integrated night vision device and laser range finder 10. Particulars of the laser range finding (LRF) operation of the device are presented below. In order to provide night vision, the device 10 generally comprises a forward objective optical lens assembly 12 (illustrated schematically as a single lens, although those ordinarily skilled will understand that the objective lens assembly 12 may include plural lens elements). This objective lens 12 performs at least two functions in the device 10, lens 12 focuses incoming light from a distant scene through the front light-receiving end 14a of an image intensifier tube 14 (as will be seen, this surface is defined by a transparent window portion of the tube--to be further described below). As was generally explained above in the discussion of the related technology, the image intensifier tube 14 provides an image at light output end 14b in phosphorescent yellow-green visible light. This image replicates the scene being viewed by use of the device 10.
The scene being viewed by use of device 10 may be a dark night-time scene which is invisible, or is only poorly visible, to the user of the device 10. On the other hand, as will be explained, the device 10 may be used to view a day-time scene, and to conduct laser range finding (LRF) in both daylight and at night. The visible image from tube 14 is presented by an eye piece lens illustrated schematically as a single lens 16 producing a virtual image of the rear light-output end 14b of the tube 14 at the user's eye 18.
More particularly, image intensifier tube 14 includes a photocathode 20 which is responsive to photons of light at the deep red end of the visible spectrum and in the near-infrared portion of the spectrum to liberate photoelectrons in a pattern replicating the scene being viewed, a microchannel plate (MCP) 22 which receives the photoelectrons in the pattern replicating the scene, and which provides a greatly amplified pattern of electrons also replicating this scene, and a display electrode assembly 24 having an aluminized phosphor coating or phosphor screen 26. A transparent window portion 24a of the assembly 24 conveys the image from screen 26 outwardly of the tube 14 so that it can be presented to the user 18.
Still more particularly, MCP 22 is located just behind photocathode 20, with the MCP 22 having an electron-receiving face 28 and an opposite electron-discharge face 30. This MCP 22 further contains a plurality of angulated microchannels 32 which open on an electron-receiving face 28 and on an opposite electron-discharge face 30. Microchannels 32 are separated by passage walls 34. At least a portion of the surfaces of the walls 34 bounding the microchannels 32 is formed by a material having a high coefficient of emissivity of secondary electrons. Thus, the channels 32 of the MCP 22 are each a dynode, emitting a shower of secondary electrons in response to receipt at face 28 of photoelectrons from photocathode 20.
The display electrode assembly 24, generally has a coated phosphor screen 26, and is located behind MCP 22 with phosphor screen 26 in electron line-of-sight communication with the electron-discharge face 30. This display electrode assembly 24 is typically formed of an aluminized phosphor screen 26 deposited on the vacuum-exposed surface of the optically transparent material of window portion 24a. The eye piece lens 16 is located behind the display electrode assembly 24 and allows an observer 18 to view a correctly oriented image corresponding to the low level image (i.e., dim or invisible, perhaps) of the scene being viewed.
As will be generally appreciated by those skilled in the art (now also viewing FIG. 2), the individual components of image intensifier tube 14 are all mounted and supported in a tube or chamber (to be further explained below) having forward and rear transparent plates cooperating to define a chamber (to be further defined below) which has been evacuated to a low pressure. This evacuation allows electrons liberated into the free space within the tube (i.e., the photoelectrons and secondary-emission electrons) to be transferred by prevailing electro static fields between the various components without atmospheric interference that could possibly decrease the signal-to-noise ratio.
As indicated above, photocathode 20 is mounted immediately behind objective lens 12 on the inner vacuum exposed surface of the window portion of the tube and before MCP 22. It is upon this photocathode that the objective lens 12 actually focuses the image of the distant scene, through the window portion which defines surface 14a. Typically, this photocathode 20 is a circular disk-like structure having a predetermined construction of semiconductor materials, and is mounted on a substrate in a well known manner. Suitable photocathode materials are generally semi-conductors such as gallium arsenide; or alkali metals, such as compounds of sodium, potassium, cesium, and antimony (commercially available as S-20). The photocathode is carried on a readily available substrate which is transparent to light in the wavelength band of interest (i.e., ordinarily in the deep-red and near infrared portion of the spectrum, extending in some cases to the blue portion of the visible spectrum--but which is not necessarily transparent to all visible light). A variety of glass and fiber optic substrate materials are commercially available.
Still referring to FIG. 2, and considering in somewhat greater detail the operation of the image intensifier tube 14 in its mode of operation providing a visible image it is seen that in response to photons 36 entering the forward end of night vision device 10 and passing through objective lens 12, photocathode 20 has an active surface 38 from which are emitted photoelectrons in numbers proportionate to and at locations replicative of the received light from the scene being viewed. In general, at night the image received by the device 10 will be too dim to be viewed with human natural vision, and may be entirely or partially of infrared radiation which is invisible to the human eye. The device may also operate in daylight to provide an image, as will be explained. It is thus to be understood that the shower of photoelectrons emitted from the photocathode are representative of the image entering the forward end of image intensifier tube 14. The path of a typical photoelectron emitted from the photon input point on the photocathode 20 is represented in FIG. 1 by dashed line 40.
Photoelectrons 40 emitted from photocathode 20 gain energy by passage through an applied electrostatic field between the photocathode 20 and the input face 28. The applied electric field is of a predetermined intensity gradient and is established between photocathode 20 and electron-receiving face 28 by a power source diagrammatically depicted in FIG. 1 and indicated by the numeral 42. Typically, power source 42 will apply an electrostatic field voltage on the order of 200 to 800 volts to maintain an electrostatic field of the desired intensity. This field is most negative at photocathode 20 and most positive at the face 28 of MCP 22. Further, an electrostatic field most negative at photocathode 20 and most positive at output electrode 24 is maintained in the image intensifier tube 14, as will be seen. After accelerating over a distance between the photocathode 20 and the input face 28 of the MCP 22, these photoelectrons 40 enter microchannels 32.
As will be discussed in greater detail below, the photoelectrons 40 are amplified by emission of secondary electrons in the microchannels 32 to produce a proportionately larger number of electrons upon passage through MCP 22. This amplified shower of secondary-emission electrons 44, also accelerated by a respective electrostatic field applied by power source 46, then exits from the microchannels 32 of MCP 22 at electron-discharge face 30.
Once in free space again (i.e., in the vacuum environment inside of tube 14), the amplified shower of photoelectrons and secondary emission electrons is again accelerated in an established electrostatic field provided by power source 48. This electrostatic field is established between the electron-discharge face 30 and display electrode assembly 24. Typically, the power source 48 produces a field on the order of 3,000 to 7,000 volts, and more preferably on the order of 6,000 volts in order to impart the desired energy to the multiplied electrons 44.
The shower of photoelectrons and secondary-emission electrons 44 (those ordinarily skilled in the art will know that considered statistically, the shower 44 is almost or entirely devoid of photoelectrons and is made up entirely or almost entirely of secondary emission electrons. This is the case because the statistical probability of a photoelectron avoiding absorption in the microchannels 32 is low). However, the shower 44 is several orders of magnitude more intense than the initial shower of photoelectrons 40, but is still in a pattern replicating the image focused on photocathode 20. This amplified shower of electrons falls on the phosphor screen 26 of display electrode assembly 24 to produce an image in visible light.
Viewing FIG. 2 in order to acquire a greater understanding of the detail of a typical image intensifier tube, the image intensifier tube 14 is seen to include a tubular body 50, which is closed at opposite ends by a front light-receiving window 52, and by a rear fiber-optic image output window 54. The window 54 defines the light output surface 14b for the tube 14, and carries the coating 26, as will be further described. As is illustrated in FIG. 2, the rear window 54 may be an image-inverting type (i.e., with optical fibers bonded together and rotated 180° between the opposite faces of this window 54 in order to provide an erect image to the user 18. The window member 54 is not necessarily of such inverting type. Both of the windows 52 and 54 are sealingly engaged with the body 50, so that an interior chamber 56 of the body 50 can be maintained at a vacuum relative to ambient. The tubular body 50 is made up of plural metal rings, each indicated with the general numeral 58 with an alphabetical suffix added thereto (i.e., 58a, 58b, 58c, and 58d) as is necessary to distinguish the individual rings from one another.
The tubular body sections 58 are spaced apart and are electrically insulated from one another by interposed insulator rings, each of which is indicated with the general numeral 60, again with an alphabetical suffix added thereto (i.e., 60a, 60b, and 60c). The sections 58 and insulators 60 are sealingly attached to one another. End sections 58 and 58d are likewise sealingly attached to the respective windows 52 and 54.
The body sections 58 are individually connected electrically to a power supply and laser range finder circuit 62 (which provides the power sources diagrammatically illustrated in FIG. 1 and indicated with reference numerals 42, 46, and 48, as described above), and which is effective during operation of the image intensifier tube 14 to maintain an electrostatic field most negative at the section 58 and most positive at the section 58d. As will be seen, the circuit 62 is also effective to control the operation of a laser to provide pulses of laser light, and to operate the image intensifier tube 14 as a detector for the reflected laser light in order to allow timing of the light pulses, and calculation of the range to a object illuminated by the laser light pulses.
Further viewing FIG. 2, it is seen that the front window 52 carries on its rear surface within the chamber 56 the photocathode 20. The section 58a is electrically continuous with the photocathode by use of a thin metallization (indicated with reference numeral 58a') extending between the section 58a and the photocathode 20. Thus, the photocathode by this electrical connection and because of its semi-conductive nature, has an electrostatic charge distributed across the areas of this disk-like photocathode structure. Also, a conductive coating or layer is provided at each of the opposite faces 28 and 30 of the MCP 22 (as is indicated by arrowed numerals 28a and 30a). Power supply 46 is conductive with these coatings by connection to housing sections 58b and 58c. Finally, the power supply 48 is conductive with a conductive layer or coating (possibly an aluminum metallization, as mentioned above) at the display electrode assembly 24 by use of a metallization also extending across the vacuum-exposed surfaces of the window member 54, as is indicated by arrowed numeral
Considering now FIG. 3, it is seen that the circuit 62 includes a power source, which in this case is illustrated as a battery 64. It will be appreciated that a battery 64 is generally used as the power source for portable apparatus, such as night vision devices. However, the invention is not limited to any particular power source. For example, a regulated line-power source could be used to provide input power to a power supply implementing and embodying the principles of the present invention. Considered generally, the circuit 62 includes three voltage multipliers, respectively indicated with the numerals 66, 68, and 70. The voltage multiplier 66 for the photocathode 20 includes two multipliers of differing voltage level, and indicated with the numerals 66a and 66b. A tri-stable switching network 72 switches controllably between alternative positions either conducting the photocathode 20 to voltage multiplier 66a, to voltage multiplier 66b, or to an open circuit position, all via the conductive connection 72a. In other words, the switching network 72 alternatingly connects the photocathode 20 of the tube 14 to a voltage source at about -800 volts, or to a source at about +30 volts relative to the front face of the microchannel plate, as will be further seen. The open circuit interval of time employed in the present embodiment between connections of the photocathode 20 to the two voltage sources 66a and 66b is used for purposes of energy efficiency, and is optional. A duty cycle control 74 controls the switching position of the switching network 72, and receives as inputs a square wave gating trigger signal from an oscillator 76, and a control signal via a conductor 78 from an ABC/BSP control circuit 80. Once again, the user of a square wave duty cycle trigger signal is optional. Other forms of duty cycle trigger waves can be employed.
Power supply to the MCP 22 (that is, to the conductive layers or metallizations 28a and 30a) is effected from the voltage multiplier 68 via connections 68a and 68b. Interposed in connection 68a is a series element 82, which in effect is a variable resistor. A high-voltage MOSFET may be used for element 82, and the resistance of this element is controlled over a connection 82a by a regulator circuit 84. Regulator circuit 84 receives a feed back control signal from a summing junction 86, which receives an input from conductor 88 via a level-adjusting resistor 90, and also receives an input via conductor 92 from the ABC/BSP control circuit 80. Conductor 88 also provides a reference voltage signal of the voltage level applied to the input face 28 (i.e., at metallization 28a) of the MCP 22 into the voltage multiplier circuit 66.
The voltage multiplier 70 has connection to the screen 26 via a connection 70a, and provides a feed back of screen current level into ABC/BSP control circuit via conductor 94. Energy flow in the circuit 62 is provided by an oscillator 96 and coupled transformer 98, with output windings 98a providing energy input to voltage multipliers 66 and 70, and a conductor 100 providing energy to voltage multiplier 68. The oscillator 96 receives a control feed back via a regulator 102 and a feed back circuit 104, having an input from a feedback winding 98b of transformer 98.
Having considered the structure of the circuit 66, attention may now be given to its operation, and the cooperation of this circuit operation with the operation of the image intensifier tube 14 to provide imaging. It will be noted that this imaging of a scene for a user of the device 10 may take place at night in conditions of viewing a scene under dark-field conditions, or during the day with the scene illuminated by sun light. It will be noted also that the voltage level produced by voltage multiplier 66a is a substantially constant voltage level. Preferably, this voltage is about negative 800 volts. On the other hand, the voltage multiplier section 66b provides a substantially constant voltage level referenced to the voltage provided by voltage multiplier 68 to the front face 28a of the MCP 22. Preferably, this voltage level is positive 30 volts relative to the front face 28 of the MCP 22.
By operation of the switching network 72, the photocathode 20 is controllably and cyclically changed between connection to the constant voltage source 66a, to an open circuit (i.e., voltage off), and to the lower voltage provided by source 66b (simulating darkness for the photocathode). This gating function is carried on at a constant frequency (preferably at about 50 Hz), with a constant cycle interval, while varying the duty cycle of the applied constant voltage from voltage multiplier 66a as a function of current level sensed at screen 26 (i.e., by feed back over conductor 94). The frequency of the duty cycle for the photocathode is sufficiently fast that no flicker is perceived in the viewed image.
Viewing FIG. 4, it is seen that over a first selected range of screen current the duty cycle of the applied constant voltage from multiplier 66a to the photocathode 20 is fixed at 100%. However, at screen current levels above a selected level of screen current, the duty cycle progressively ramps down substantially linearly to a low level of essentially 10-4% as a function of increasing screen current. For screen current levels above that at which the duty cycle for gating of the constant voltage from source 66a to the photocathode 20 drops to its low level, an additional function of BSP is provided by decreasing the voltage applied to the MCP 22. As FIG. 5 shows, for all screen current levels lower than those necessary to initiate this BSP protection function, the voltage applied across the MCP 22 is a constant. The reduction of voltage level applied across the MCP 22 for BSP is effected by action of the series element 82 increasing its resistance under control of MCP regulator 84.
As noted this regulator 84 receives a summed input from the voltage multipliers 66, and from the ABC/BSP control circuit 80, which is responsive to screen current level sensed by conductor 94. An understanding of the voltage level experienced as a function of time within duty cycle intervals at the photocathode 20 can be obtained by noting that a virtual capacitor exists between the photocathode 20 and the front face 28 of MCP 22. This capacitor exists electrically, but not as a conventional capacitor structure. On FIG. 3, this virtual capacitor is diagrammatically indicated, and indicated by the arrowed reference character "C". When the duty cycle for the application of the constant voltage supplied by voltage multiplier 66a is 100%, or close to this level, then following the opening of the circuit through switching network 72, the voltage across the virtual capacitor "C" decays over a time interval at a natural open-circuit, capacitor-discharge rate. This voltage decay is actually a very small voltage because of the short time interval (i.e., 1/50th second at a 50 Hz frequency for the gating operation of switching network 72).
Next in each duty cycle, the network 72 conducts the photocathode to voltage multiplier 66b, which effectively replicates darkness for the photocathode 20 by dropping the voltage on the photocathode to +30 volts relative to the face 28 of MCP 22. As noted above, this voltage cutoff is provided by having voltage multiplier 66b provide a voltage which is about 30 volts positive with respect to the voltage provided at coating 28a on the front face of the MCP 22 by voltage multiplier 68.
In essence, when the photocathode 20 operates, it always operates at the high constant voltage provided by voltage multiplier 66a. When the photocathode 20 is not operating, it is switched to a voltage which replicates a dark field for the photocathode (i.e., the +30 volts from voltage multiplier 66b). The photocathode 20 operated by the circuit 62 of the present invention is switched between operation at its designed voltage level and dark-field condition at a duty cycle which varies dependent upon the light intensity of the scene being viewed, as indicated by current flow at the screen 26.
This function is carried out in accord with the duty cycle function in order to provide ABC. The result of this ABC operation is a substantially constant brightness for the image presented to a user of the night vision device 10 is achieved, until the scene becomes too dim to produce an image even with image intensification technology. In other words, over the entire operating range of the image intensifier tube 14, its operation by circuit 62 provides substantially constant brightness for the image presented to the user of the device.
Further considering the operation of circuit 62 to provide an image for the user of the device 10, is seen that once the duty cycle is reduced to its low level of 10-4%, in the event that screen current increases further, then as a function of increasing screen current the voltage across the MCP 22 is reduced slightly, viewing now FIG. 5. This reduction of MCP voltage has the effect of providing BSP. That is, after the ABC function has reached its lowest level of duty cycle to the photocathode 20, if light level of the viewed scene continues to increase (indicative of a bright source in the scene), then the duty cycle maintains its low 10-4% level, while the bright-source protection function explained above is effected.
LASER RANGE FINDING
Further considering now FIGS. 1 and 3, the operation of the device and circuit 62 to provide a laser range finder function will be explained. The device 10 further includes a laser 106 capable of projecting a high-energy, short-duration laser light pulse 106a into the scene being viewed by the operator of the night vision and laser range finder device 10. This pulse of laser light is diagrammatically illustrated on FIG. 3 with the arrow 106a, and by the user of appropriate reflective surfaces and lenses (not shown) may be arranged to project outwardly through the objective lens 12 toward the scene being viewed. It will be understood that the laser light 106 need not project outwardly through lens 12. For example, a separate set of projection lenses can be provided for laser 106 in order to project the laser light pulse 106a. As is explained in this disclosure, in the event that the laser pulse is not projected from lens 12, then the hard turn off time interval of operation for image tube 14 in a laser range finding operation need not be employed. In this case, laser range finding operations can be conducted using an image intensifier tube as a sensor for the reflected laser light otherwise as disclosed herein.
Laser 106 is powered by a laser driver circuit, indicated with numeral 108. A laser range finder (LRF) control logic circuit 110 (the operation of which will be further explained below) provides a control input to the driver circuit 108 to effect operation of the laser 106, and also provides a control input to the oscillator 96 via a conductor 112.
Conductor 112 at a branch 112a thereof also provides a control input to an actuator 114, which in response to this control input moves a spatial filter 116 (to be further described below) into and out of the optical pathway between lens 12 and the image intensifier tube 14, as is indicated by dashed lines on FIG. 1. The spatial filter 116 is essentially a shutter or centrally apertured plate, which blocks returning laser light from portions of the viewed scene other than in the central area where the object of interest is located. During a LRF operation, the actuator 114 pauses the spatial filter 116 in the optical pathway of the device 10. That is, this is a controlled momentary pause between the inward and outward movements of these filters. During the pause of the filter(s) in the optical pathway, laser light is projected to an object in the viewed field, and reflected laser light returned from the object for a LRF operation is received at the device 10.
The LRF control logic circuit 110 also has a control output 118a to a gating control circuit 118. This circuit has connection to switching network 72, as is illustrated. An operator-input command switch 120 is provided by which the operator of the device 10 can indicate a command that a LRF operation be carried out be the device 10. The remainder of the elements of the device 10 will be described in connection with a LRF operation.
A LASER RANGE FINDING OPERATION
Considering FIG. 3 still, when the operator of the device 10 wishes to obtain range information to an object in the viewed field, the operator centers the object in the viewed scene, possibly by using a reticule provided by the device 10, and makes a LRF input command at 120. This input command may be effected by use of a simple push-button switch, for example. In response to this input command, the LRF control logic circuit 120 effects the following sequential activities in order:
First, the oscillator 96 is shut down by a command over conductor 112. This command also has the effect of causing actuator 114 to move the selected spatial filter 116a/b into the optical pathway. The shutdown command for the oscillator 96 also is used to cause the voltage multiplier 68 to drive the MCP 22 to a high-gain voltage level. Preferably, this high-gain voltage level is a differential voltage of about 1200 volts across the MCP 22.
Second, the LRF control logic circuit commands the switching network 72 to perform a timed switching operation (as is further described below), first switching photocathode 20 to the voltage from multiplier 66b (i.e., to +30 volts relative to the front face of MCP 22--effecting a hard turn off for the photocathode of the tube 14); and then later in timed relation connecting this photocathode to source 66a.
Third, after a time interval of about 3 ms (which is required to allow the oscillator 76 to stop its operation), the laser light pulse is fired. The photocathode 20 is then effectively switched to the voltage source of multiplier 66a (i.e., to about -800 volts). Actually, the photocathode 20 is switched to voltage source 66a in timed relation before the laser light pulse is fired. The photocathode needs to settle from about 200 μs before the laser is fired. In order to provide a non-responsiveness of the device 10 to the back scatter of laser light which may occur in the optics, amplifier 132 is causes to have a time-dependent gain. One way in which this time-dependent gain may be implemented is to provide a high threshold value which the electron pulse from image intensifier tube 50 must exceed before the signal is provided to stop timer 126. This threshold value would be high immediately after laser pulse 22 is fired, and would decrease as a function of time after the pulse is fired. Another alternative is to have a step-function change in the threshold value at a certain time after the laser light pulse is fired. In this way, the timer 126 will respond to the electron pulse resulting from reflection 24, rather than to the back scatter of laser light from surfaces of the lenses in the device 10.
Fourth, shortly after the time the LRF control logic commands the laser 102 to fire a pulse of laser light into the scene which was being viewed by the user of the device 10, this pulse will actually be fired. A time-zero (t0) detector 122 detects the moment of actual firing of this laser light pulse, and provides a signal on conductor 124 which starts a high-speed digital timer 126. Prior to the moment of firing of this laser light pulse, the photocathode is connected to voltage source 66b (i.e., to the +30 volts relative source) for a purpose to be further explained below.
Fifth, when the laser light reflects from an object in the scene, returning laser light passes through a central aperture 116a or 116b of spatial filter 116, so that reflections of laser light from other objects in the scene are blocked (i.e., having the effect of increasing the signal to noise ratio of the returning light pulse). The optical filter 140 also has a beneficial effect on signal-to-noise level during day time LRF operations, because it removes some of the background light from the day-time scene which is present at frequencies close to that of the laser 106. The returned laser light (still in the form of a pulse) passing to image intensifier tube 14 causes a pulse of photoelectrons to be released by photocathode 20, as is graphically depicted on FIG. 1 and indicated with the character "P1". The pulse P1 of photoelectrons passes to MCP 22, and causes a corresponding pulse of secondary-emission electrons "P2" (produced under "high gain" conditions for the microchannel plate 22), which electrons pass to the output electrode assembly 24. A corresponding pulse in the current from screen 26 is detected at conductor 128 having interposed capacitor 130, and is passed to a high-gain amplifier 132. Amplifier 132 provides a timer-stop command over conductor 134 to high-speed timer 126.
Next, spatial filter 116 is withdrawn from the optical pathway, the oscillator 76 is restarted, and the gating operation of the switching network 72 is resumed (if it was operating before the LRF operation as a result of the light conditions in the field being viewed. In other words, the explanation below concerning daytime operations of the device 10 may be consulted at this time. The image of the scene being viewed is thus restored for the user of the device 10. During the LRF operation, the operator of the device 10 may detect a flicker in the viewed image along with a very brief flash of light (i.e., from the pulse of electrons P2 impacting the screen 26). The LRF operation takes only about 5 ms to complete (although the physical movements of filters 116a/b will be somewhat slower than this) so the user's view of the scene in not significantly interrupted.
The time interval between the to signal and the timer-stop command is provided by the timer 126 to a range calculator 136, which then supplies an output (indicated with arrowed numeral 138) of range information to the object for the operator of the device 10. It will be noted that prior to the firing of the laser light pulse, the photocathode is connected to voltage source 66b, which is about +30 volts positive relative to the face 28 of microchannel plate 22. This positive voltage level on the photocathode 20 has the effect of a "hard turn off" on the photocathode, preparing it to be somewhat insensitive to photons of laser light which may be back scattered from surfaces of the lenses between laser 106 and the projection outwardly of the beam 106a. That is, laser light may be reflected within the device 10 during the firing of this laser light pulse, but the image intensifier tube is momentarily somewhat blinded to this light after the hard turn off effected on photocathode 20, even though voltage source 66a is connected before the actual moment of firing of this laser light pulse in order to provide charge settling on the photocathode.
DAYTIME IMAGING AND LRF OPERATION
It will be noted that for daytime operation of the device 10, the BSP function is disabled, and the ABC function of the device 10 allows imaging to be accomplished in daylight. Accordingly, the ABC function may be operating the photocathode at less than 100% duty cycle. Under these conditions, a LRF operation additionally momentarily interrupts the duty cycle gating operation carried out by switching network 72, and effects the switching of the photocathode 20 to the voltages provided by sources 66b and 66a (in sequence as described above) in order to effect the hard turn off of the photocathode during laser firing, and then to allow the photocathode to be highly responsive to photons of reflected laser light in order to provide the LRF pulses P1, as described above.
Further, it should be noted that spatial filter 116 can be provided with apertures 116a/b of differing sizes. That is, this filter may be provided with a filter blade having an aperture of about 18 mm (for example) for use in night time LRF operations, and with an alternative filter blade having an aperture of about 2 mm for use in day time LRF operations. Also, selection of one or the other of these spatial filters may assist in LRF operations at night or in day time when the user of the device is ranging on objects having high or low reflectivity. A selector 116d allows the user of the device to select which one of the spatial filters 116a or 116b is moved into the optical pathway during LRF operations by the actuator 114.
Further, an optional optical filter 140 may be provided, which functions as a band-pass notch filter to preferentially pass the wavelength of the laser light from laser 106, thus further improving the signal to noise ratio during LRF operations in day time. During day time observation and LRF uses of the device 10, the optical filter 140 is preferably always used. An actuator knob 140a is provided on the device 10 to manually move the filter 140 into and out of the optical pathway leading to the image intensifier tube 14, and is marked as indicated for day and night operations of the LRF function.
Those skilled in the art will appreciate that the embodiment of the present invention depicted and described herein and above is not exhaustive of the invention. Those skilled in the art will further appreciate that the present invention may be embodied in other specific forms without departing from the spirit or central attributes of the invention. For example, it is clear from the description above that a viewing device using an image intensifier tube may also perform laser range finding functions using the image intensifier tube as a sensor for the reflected laser light pulse without using the "hard turn off" technique described herein. Such a device would project the laser light pulse for laser range finding using a separate projection optical system. The image intensifier tube would still be used as a sensor by insuring that the photo cathode and microchannel plate of the tube are in high gain conditions during the interval in which the laser light pulse returns. In this way, the electrical response of the image intensifier tube can be used to initiate the "timer stop" command necessary for measuring the transit time for the laser light pulse to and from the scene and object of to which a range is desired. Because the foregoing description of the present invention discloses only an exemplary embodiment, it is to be understood that other variations are recognized as being within the scope of the present invention. Accordingly, the present invention is not limited to the particular embodiment which has been depicted and described in detail herein. Rather, reference should be made to the appended claims to define the scope and content of the present invention.
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|US8981295||Jul 18, 2012||Mar 17, 2015||Kenneth JAMISON||Night vision device with display of ancillary environmental information|
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|US20060054778 *||Jan 27, 2004||Mar 16, 2006||Klaus Suhling||Photon arrival time detection|
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|DE10341671A1 *||Sep 8, 2003||Apr 7, 2005||Adc Automotive Distance Control Systems Gmbh||Umgebungsüberwachungssystem mit Nachtsichteinheit und Entfernungsmesseinheit|
|WO2004070419A1 *||Jan 27, 2004||Aug 19, 2004||Imp College Innovations Ltd||Photon arrival time detection|
|WO2005052633A1 *||Oct 29, 2003||Jun 9, 2005||Brockherde Werner||Distance sensor and method for distance detection|
|WO2008113872A1 *||Mar 19, 2007||Sep 25, 2008||Leo Jose Munoz||System for artificially improving contrast for displaying images|
|U.S. Classification||250/214.0VT, 313/103.0CM, 348/E05.09|
|International Classification||G01S17/89, G01S7/481, G01S17/02, H01J31/50, H04N5/33|
|Cooperative Classification||H01J31/507, G01S17/023, G01S7/481, H04N5/33, G01S17/89|
|European Classification||G01S7/481, H04N5/33, H01J31/50G2, G01S17/02C|
|Mar 2, 1998||AS||Assignment|
Owner name: LITTON SYSTEMS, INC., CALIFORNIA
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SALDANA, MICHAEL R.;REEL/FRAME:009017/0036
Effective date: 19980124
|Mar 19, 2004||FPAY||Fee payment|
Year of fee payment: 4
|Mar 14, 2008||FPAY||Fee payment|
Year of fee payment: 8
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Owner name: L-3 COMMUNICATIONS CORPORATION, NEW YORK
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:NORTHROP GRUMMAN GUIDANCE AND ELECTRONICS COMPANY, INC.;REEL/FRAME:023180/0962
Effective date: 20080418
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Free format text: CHANGE OF NAME;ASSIGNOR:LITTON SYSTEMS, INC.;REEL/FRAME:023180/0884
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Owner name: L-3 COMUNICATIONS CORPORATION, NEW YORK
|May 16, 2011||AS||Assignment|
Effective date: 20080603
Free format text: CORRECTIVE ASSIGNMENT TO ADD OMITTED NUMBERS FROM THE ORIGINAL DOCUMENT, PREVIOUSLY RECORDED ON REEL 023180, FRAME 0884;ASSIGNOR:NORTHROP GRUMMAN GUIDANCE AND ELECTRONICS COMPANY, INC.;REEL/FRAME:026423/0191
Owner name: L-3 COMMUNICATIONS CORPORATION, NEW YORK
|Mar 15, 2012||FPAY||Fee payment|
Year of fee payment: 12


text:
Author ~ Eli Easton
Narrator ~ Tristan Wright
Publisher ~ Pinkerton Road
Release ~ 16th December 2016
Length ~ 4 hours and 45 minutes
Genre ~ Contemporary M/M Romance
Toby Kincaid loves being the junior librarian in his hometown of Sandy Lake, Ohio. He spends his days surrounded by books and chatting with the library patrons. He especially adores the head librarian, Mr. Miggles, who is kind, witty, knowledgeable about everything, and hopelessly addicted to Christmas. Sean Miggles is also pretty cute - especially for an older guy who wears ties and suit pants every day.
But Sean keeps himself at a distance, and there's a sadness about him that Toby can't figure out. When Sean is accused of a crime he didn't commit, he gives up without a fight. Toby realizes that he alone can save the library - and their head librarian.
Toby will need to uncover the darkness in Sean's past and prove to him that he deserves a second chance at life and at love too. And while Christmas miracles are being handed out, maybe Toby will get his own dearest wish - to love and be loved by Mr. Miggles.
I recently enjoyed the ebook of Merry Christmas, Mr. Miggles and was eager to listen to the audio version narrated by Tristan Wright. He also narrated another favourite Eli Easton story of mine—Superhero—so I had high expectations for this one. I’m pleased to say it’s a delightful production that had me totally immersed in the story the second time around. Eli’s writing style and characters always hold my attention and stir up all sorts of emotions. She creates lovely stories that elicit tingly feelings and angst on behalf of the protagonist and their love interest.
In this case, Sean Miggles and Toby Kincaid are the two adorable and lovelorn characters. They work together in a small town library but don’t socialise outside of the building. Mr. Miggles is devoted to his role as head librarian. He’s a good man, gentle and kind and with a huge heart, a great boss for Toby, and a passionate member of the community, sometimes going above and beyond his duty to help its patrons. He ensures the library is a welcoming place, especially at Christmastime. Yes, he appears rather a stiff and serious head librarian at first, but his friendship and camaraderie with Toby, his junior, is often fun and light-hearted. He’s rather formal in his appearance and his old-fashioned attitude comes across older than he actually is. He wears amusing ties that hint at another side to his personality and that is also seen in his dry wit. He does have a mysterious air to him that Toby gradually uncovers. Plus he’s smoking hot in his jeans and informal clothes!
Toby Kincaid, the POV character, is younger and full of life. He’s also kind and is committed to the job he loves. His boyfriend is obnoxious and takes advantage of Toby’s generosity. Luckily, Toby is coming to realise what a loser he is!
A wonderful slow-build romance develops between Sean and Toby that didn’t look like it was going to get a chance to bloom with all the drama that occurs involving the library and Mr. Miggles. It was nice to see them spending time together outside of the library and start to acknowledge their feelings and attraction for each other. The love interest is a slow burn, but there are a couple of beautiful moments along the way, leading to some sizzling scenes towards the end of the story. There was no miscommunication between these two lovers and I was definitely rooting for them along the way.
There’s a great supporting cast of family members and visitors to the library. The season of goodwill to all men—and children—unfortunately backfires on poor Mr. Miggles. He’s a wonderfully generous man and his kindness is abused. My heart went out to him when he was falsely accused by a few mean-spirited people. But Toby fought for love and his boss. I loved the feel of community that revolves around the library, the appreciation for Mr. Miggles and his important role in the town, all of which makes this such a terrific feel-good story.
Tristan Wright’s narration of this lovely Christmas tale was a pleasure to listen to. His narrative voice as Toby was spot on and he managed to give Mr. Miggles his own distinctive tone that matched his old-fashioned character. He conveyed the emotions and the dialogue between the two main characters very well and clearly portrayed the other characters too. Highly recommended.
Connect with Eli Easton
Having been, at various times and under different names, a minister’s daughter, a computer programmer, a game designer, the author of paranormal mysteries, a fan fiction writer, an organic farmer and a profound sleeper, Eli is happily embarking on yet another incarnation as a m/m romance author.
As an avid reader of such, she is tinkled pink when an author manages to combine literary merit, vast stores of humor, melting hotness and eye-dabbing sweetness into one story. She promises to strive to achieve most of that most of the time. She currently lives on a farm in Pennsylvania with her husband, three bulldogs, three cows and six chickens. All of them (except for the husband) are female, hence explaining the naked men that have taken up residence in her latest fiction writing.
Connect withTristan Wright

domain: library


text:
Being able to demonstrate the impact of a charity’s services is increasingly important. Many large funders, including the Big Lottery Fund, now expect organisations (re)applying to them for existing services to demonstrate the project’s outcomes and impact through an external evaluation. This is an evaluation carried out by someone from outside of the organisation, who can bring a truly objective viewpoint.
As a result, many organisations, consultants and even university departments now offer external evaluation services. However, these evaluations, despite being relatively expensive, can be of variable quality. We have externally evaluated £2.7million worth of programmes, many funded by the Big Lottery. We ensure our external evaluations support both fundraising and future project development, meaning that they can bring ‘maximum benefit’ to charities.
Our evaluations include:
- A quantitative analysis of a project’s progress against its original targets. This enables a charity to accurately report to the funder.
- Qualitative data from project beneficiaries, for example through focus groups and beneficiary case studies. This data is carefully analysed against the expected project outcomes, to fully understand the project’s social impact.
- A cost-benefit analysis of how the per beneficiary cost of the project relates to the costs to society of not providing the support. This is often crucial in persuading funders that an ‘expensive’ project is in fact very good value when considering the millions of pounds ‘saved’ in avoided costs to local services, the NHS and the criminal justice system!
- Recommendations on how the project, and the management and organisational systems that support it, can be improved. This is often missing in other evaluations, but we believe it is crucial. Without this information, charities may understand a project needs to improve, but aren’t given a clear steer on how this can be achieved. Without these recommendations, it is also harder to make clear to a funder how you will develop and improve a project – key information for the majority of funders who may fund an existing service.
This approach has proven to be successful with our clients. Bright Ideas undertook yearly external evaluations of Victim Support’s Young Victims’ Project, over a three year period.
This project was funded by the Big Lottery’s Reaching Communities Fund, and the evaluations supported the reporting process. These evaluations involved focus groups with young people, aged 6 to 21, who had been victims of serious crimes; as part of this we had to be conscious of data protection, ethical issues and other sensitivities.
We had to ask the young people questions about their experiences sensitively to avoid re-traumatising them. The evaluations made clear recommendations to improve the project over its lifetime to secure the best possible outcomes for beneficiaries. The final evaluation also made future recommendations, which formed the foundation of a successful reapplication to the Big Lottery Fund.
Do get in touch if you are considering undertaking an external evaluation of one of your projects.

domain: sociology


text:
Polka Dot Press owner always wanted to open her own business
TCC helped Kim Williams figure out her future
Kim Williams, owner of the Polka Dot Press, was always an entrepreneurial type. She developed an early interest in retail and worked in the industry while still a teenager. After graduating from Lincoln High in 1985, Williams decided to attend Tallahassee Community College.
“I was pretty sure what I wanted to do, but I wasn’t completely sure, so I wanted those two years to figure it out before declaring a major,” she said.
The time at TCC gave Williams the chance to confirm that she was on the right path. She then went on to study fashion merchandising at Florida State University.
In her late 20s, Williams opened her first store in Tallahassee. Three years later, she married her husband, Mike. Williams, wanting to start a family and looking for more stable employment, closed the shop and went to work for a state agency.
“I quickly realized that bureaucracy was not for me,” she said. “I’ve always been a hang-out-shingle kind of girl; I want to do my own thing. So I quit my job. When I told my husband—back then we were young and poor—he asked me, what are you doing? And I said I’d figure it out.”
And she did. While staying at home with her young son, Williams taught herself how to make custom invitations on her computer, planting the seeds for what would become the Polka Dot Press.
“It was all very organic,” she said. “After I started doing my son’s invites, a neighbor down the street asked if I would do hers, and it sort of grew from there.”
Soon, Williams was showcasing her invitation samples at craft shows. Five years ago, she opened her storefront on Market Street in Tallahassee. Though The Polka Dot Press still specializes in custom invites and monograming, the store allows Williams to carry gift items like specialty candles and beauty products.
Williams is grateful for her two years at TCC and hopes her son, now in high school, will start his college career at TCC, too.
“I’m encouraging my son to do it, not because it’s an easier path, but because going to TCC helps focus you for those first couple of years, and I think he and so many others can benefit from that.”
As part of TCC’s 50th anniversary, The Democrat is publishing profiles of 50 notable alumni. Look for them each week in Monday’s paper.

domain: news


text:
Researchers in the United States and China have teamed to develop a speedway for future devices, an exotic type of electrical conductor called a topological insulator (TI). In a new paper in the journal AIP Advances, the international collaborators report that they grew two types of TI materials inside an ultra-high vacuum chamber on both smooth and rough surfaces and then evaluated their abilities to transport electrons.
New work opens the fascinating prospects of single-molecule microscopy and spectroscopy on a smart phone. One can now speculate on the possible applications of such a portable imaging device and on the perspectives it may open in different fields of science and technology.
A breakthrough in photonics that will help create extremely compact optical chips, a hair's width in size and delivering a photon at a time, has been achieved by researchers from the University of Sydney.
Researchers have used an electron microscope to bend, deform and melt the one-molecule-thick glass. These are all things that happen just before glass shatters, and for the first time, the researchers have directly imaged such deformations and the resulting 'dance' of rearranging atoms in silica glass.
Researchers have developed a new model that allows better control of self-assembly, the process through which molecules aggregate by themselves into larger clusters. This model could be used in the production of plastic solar cells, and is an interesting step in the long?term process of developing a synthetic cell.


text:
***CAUTION: Here there be spoilers!***
Marvel’s animated series “What If…?” is quickly drawing to a close, with the final episode set to premiere on Disney+ on Sept. 29. In each 30-minute episode, the series reveals how events might have played out if an MCU character had made a different choice than they did in the “canon” timeline. Although the premise seems harmless and fun, Marvel’s first animated series has proven itself to be one of the darkest MCU installments yet.
The very principle of “What If…?” is that events do not unfold in the same way we have seen previously – and, by the same token, familiar characters do not have the same fates. Main Avengers, such as Iron Man, Thor, Black Widow and Captain America, are no longer “protected” by their status as leading characters. Instead, in “What If…?”, we see these MCU figureheads killed off quickly, repeatedly and often brutally, far from the meaningful sacrifices of “Avengers: Endgame” (2019).
In Episode 6, for example, T’Challa/Black Panther, Rhodey/War Machine and Tony Stark are all murdered by Killmonger in less than five minutes. In Episode 3, an assassin targets the Avengers and kills almost all the core members before they can ever assemble. And, of course, in Episode 5, a zombie apocalypse transforms most of Earth’s mightiest heroes into brain-eating machines.
“What If…?” doesn’t elicit the same stirring, uplifting emotions as a typical MCU production. On the contrary, the animated series has a grim undertone, a pervasive sense of danger and moments of pure horror. No one is safe. Victories, when they do come, are bittersweet, and hope is mixed with fear and grief. Rarely do episodes have happy endings, even more rarely resolved ones. However, “What If…?” brings something different to the MCU – a dose of reality.
Ironically, Marvel’s first animated series delves closer to the complexity, loss and failure of real life than any of the live-action films and shows to precede it. For example, in Episode 4, Dr. Strange becomes consumed by grief after losing the love of his life. He pursues darker and more potent sources of power until he becomes a monstrous version of himself, and, by trying to alter a fixed point in time, he destroys his own reality. Although the episode is horrifying, it emphasizes how easily Dr. Strange could have gone down such a path. In many cases, if our heroes had not chosen the “noble” way, their great power could have devastated the world.
This is one of the most unsettling and thought-provoking aspects of “What If…?”: that the alternate scenarios it proposes are not improbable. In fact, “What If…?” raises the idea that perhaps the events we see in the “canon” MCU films and shows are – like the victory of “Endgame” – the one outcome in fourteen million where our heroes win. In yet another breakthrough for the studio, Marvel’s venture into the realm of animation has brought us the most pragmatic look at the MCU so far.

domain: artistic


text:
Threats to protection officers working at Parliament by a man repeatedly speeding past the front of the building prompted new security measures labelled “ugly” and “cheap” by MPs on all sides of politics.
Large concrete bollards resembling soakwells, or industrial-sized sewerage pipes, have been placed either side of the front steps of the heritage-listed building to thwart vehicles being used in terrorism attacks.
But their appearance was condemned as an “eyesore” yesterday, and ignited debate about the lack of Government funding for a “sophisticated” security solution.
It is understood a man sped through the forecourt entrance to Parliament four times this year, resulting in the $22,000 quick fix.
On one occasion he drove alongside uniformed security staff and warned them to be “very careful today” before speeding away.
The man has been spoken to and assessed by WA Police, and is not considered a terrorism threat.
“With what has been happening in Australia we had to do something,” Lower House Speaker Peter Watson said. “Imagine if we hadn’t put them up and something happened.”
Premier Mark McGowan said he was not aware the bollards were being installed but he understood the need for greater security where the public gathered in large numbers.
Shadow police minister Peter Katsambanis blamed the “cut-price” bollards on the Government not funding Parliament’s security needs.
“People should be able to gather on the steps of their Parliament knowing they are being protected by the best safety measures available, not a cut-price, interim measure that does not appear to be up to the task,” Mr Katsambanis said.
Attorney-General John Quigley agreed that the bollards looked “shocking”.
“I thought it was a joke when I first saw it,” he said. “This amounts to half a dozen sewerage pipes or soakwells standing up to create an obstacle course.”
The head of parliamentary services wanted to provide a long-term solution but did not have the money in his budget, it was revealed recently.
Rob Hunter said the front of Parliament was open to “hostile vehicle attacks” and to do nothing would be “a failing on our part”.
President of the Legislative Council, Labor MP Kate Doust, said the bollards were “an eyesore” and only a “stopgap until funds are found” for a redesign.
“It is planned to beautify the bollards with plants and paint,” she said.
Liberal MP John McGrath said the concrete pipes should be replaced with modern, automated pop-up bollards.
Nationals MP Vince Catania said they looked “horrendous”.
“Parliament House looks like a Pilbara mine construction site,” he said.


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Certified high-visibility, stretch, breathable polyester fabric
Large pocket on the chest


text:
One of the most important rituals to be followed at Seder is those of four questions that are to be answered by the youngest child at the table. The concept originated to make the children feel involved in the Passover celebration and arouse curiosity in them. The ceremony is based mainly on the commandment in the Bible that reads - "And thou shalt tell thy son". The Haggadah, the Book of Exodus also stresses the importance of the Seder to excite the interest of the children. At the Seder, the Haggadah is read and stories narrating the history of the Hebrew slaves of Egypt are told who walked away to freedom and established their own kingdom as Israelites under the guidance of God and Prophet Moses are told. Songs and sung and prayers are told to thank the Lord for the liberation from slavery. The four questions that are asked are given here along with their answers.
The Four Important Questions
1. Why do we eat only Matzoh on Pesach and not all kinds of breads and crackers like other nights?
"She-be-chol ha-lelot anu ochlin chametz u-matza, ha-laila ha-zeh kulo matza?"
When Pharaoh finally ordered Jews to get out of Egypt after the tenth plague, they were in such a hurry to get away from slavery that they hadn't time to let their dough rise and bake their bread. Thus, they took the raw dough with them on their journey and baked it into hard crackers in the hot desert called Matzoh. Thus, we eat only Matzoh on this day to remind us of their struggles.
2. Why do we eat bitter herbs or Maror at our Seder?
"She-be-chol ha-lelot anu ochlin she-ar yetajit, ha-laila ha-zeh moror?"
Maror or the bitter herbs are eaten to remind us of the bitterness of slavery and harsh and cruel ways in which Jewish people were treated as slaves under the Pharaoh in Egypt.
3. At our Seder, why do we dip the parsley in salt water and the bitter herbs in Charoset?
"She-be-chol ha-lelot en anu matbilin afilu pa'am echat, ha-laila ha-zeh shetay fe'amim?"
Parsley represents new life and spring while salt water represents tears of Hebrew slaves and how hard the Jewish slaves worked in Egypt. Parsley dipped in salt water thus represents new life that emerged from the tears and hardship of the Jewish slaves. Bitter herbs dipped into Charoset represent the bitter days of slavery. Charoset the mixture of chopped apples and nuts has a coarse texture like clay used to make bricks for the Pharaoh's buildings.
4. Why do we lean on a pillow while eating tonight and do not sit straight like other nights?
"She-be-chol ha-lelot anu ochlin bayn yoshvin u-vayn mseubin, ha-laila ha-zeh kelanu mesubin?"
Leaning on a pillow signifies the comforts of freedom. As slaves, our ancestors had little comforts. Thus, we lean on a pillow to assert that we are free now we can sit straight or lean on a pillow as much as we like. And because of the efforts and hardships endured by the ancestors, we now enjoy the comforts and leisure's of a relaxed life.
These four questions form the central theme of all Seder meals during Passover Holidays. These qusetions together are called "Mah Nishtana" (Mah Nishtanah, Ma Nishtanah, or Ma Nishtana). It is loosely translated in English as "Why Is It Different", "What Is Different" or "How Is It Different and are referred to how and why the Passover evenings or days are different from all other evenings or days of the year. These questions are traditionally given to the youngest child in the family at the Seder table to be read aloud. The traditional structure of the story is that there is one question with four clauses. The four clauses or answers explain how Passover festival is unique compared to other times of the year. The main question or the introductory question thus is "Ma nishtana ha-laila ha-zeh mi-kol ha-lelot?" Or "why is this night different from all other nights?" This was illustrated by Mishna of the Talmud (Pesachim 10:4) where a child asks the questions to the father. This story is then continued with the story about The Four Sons. This is an effort by early Jewish communities to encourage the future generation children and youth to be aware of their traditions and history.
The Seder rituals are meant to excite the curiosity of children and make them ask why things happen so at Passover. The ritual of four questions at the Seder table is an important one.


Traing Methods And Drills For Sport, Hunting, Selfdefence And Long Ran
Traing Methods And Drills For Sport, Hunting, Selfdefence And Long Range Shooting
Dry Fire Drills
Dry firing is the practice of "firing" a firearm without ammunition or practicing the manipulation of a firearm with an inert training platform such as a MantisX. If done incorrectly, dry firing may be mechanically damaging to some firearms – especially rimfire weapons, where the firing pin in most designs will impact the breech face if the weapon is dry-fired. Because of this, precautions (such as the use of snap caps) need to be taken if such a weapon is to be deliberately dry-fired.
There are many benefits to dry firing. Learning is faster and can be safer with dry fire. It's easier to practice without developing a flinch. Dry fire allows shooters to practice in locations where they couldn't practice with live ammo. You can practice grip, drawing, sight alignment, trigger control, reloads, malfunctions, and more during dry fire practice. The technique allows people to conduct a safe, economical form of training to improve their shooting skills. An emphasis is placed on safety to prevent an accidental discharge. Training should be conducted in an area with no ammunition and with a suitable backstop.
In recent years, a number of companies have developed methods of enhancing dry fire practice to improve skills. Products that fire a laser, as opposed to a solid projectile, have become increasingly popular. These include chamber inserts available for various caliber firearms, as well as dedicated training pistols or replacement AR-15 bolt carrier groups. There are also a number of target systems for these laser dry fire training aides and electronic devices combined with smart application such as MantisX , that are becoming more affordable and popular. These products help people get more from dry fire practice by providing feedback on shot placement and times, and make dry fire a more enjoyable experience. In addition, there are training aids such as training cards that provide shooters a variety of drills to do that will help them develop skills that will carry over to live fire.
Dry practice (dry fire training) can be boring and monotonous if you don't add in new drills once in a while. It's also important that you include new drills to make sure you are preparing for a variety of circumstances. Here is a specially prepared list of some of our favorite dry practice drills, and variations on drills you probably already do. We do these regularly in our dry practice/dry fire training and they've helped us improve.
A MantisX is not necessary to perform these drills, although we highly recommend using one!
List of Dry Fire Drills
Perfect Trigger Control
Take your time pressing the trigger. Watch your sights to make sure they do not move when the shot breaks. (And use a MantisX for instant, actionable feedback!)
Perfect trigger control Take your time, this is to fine tune your trigger control.
Compressed surprise break On the signal from the buzzer, press the trigger smoothly, as quickly as you can while maintaining perfect control.
Primary hand only
Support hand only
Presentation and surprise break
Safely present the gun to the target, acquire your sight picture, and achieve a surprise break. Work on speeding up over time. Only go as fast as you can do it safely.
Target in front All draws can also be performed from concealment.
Target 90 degrees to the right Pivot as desired.
Target 90 degrees to the left
Support hand only (with primary side holster) Draw the firearm with only your support hand.
Draw from sitting, target in front You can stand for the shot or remain seated.
Draw from sitting, target 90 degrees to the right
Draw from sitting, target 90 degrees to the left
Draw from sitting at a table, target to the rear Pivot and stand during presentation, maintaining muzzle control.
Draw from behind cover Use right and left side cover. Practice standing and kneeling.
Draw while laying on your back, targets in all 4 directions
Draw and fire with Harris Flashlight Technique Draw the flashlight and the pistol in the same motion. Make sure not to muzzle your flashlight hand.
Shot from the guard With your firearm in the guard position, bring the gun onto the target and fire.
Shot from hoster to Close Contact Draw only to Close Contact.
Malfunction Clearing and reloading
Use dummy rounds to set up the malfunctions. All of these can and should be practiced one handed as well.
Type I Malfunction (Misfire)
Type II Malfunction (Failure to Eject)
Type III Malfunction (Feedway Stoppage)
In Battery Reload In battery = slide forward.
Out of Battery Reload Out of battery = slide locked to the rear.
Tactical Reload A tactical reload occurs when there is still ammunition in the magazine being removed from the gun.
Malfunction clearing and reloading in the dark
Simulate effective malfunction clearance and reloading in the dark. Use dummy rounds to set up the malfunctions. Close your eyes or blindfold yourself to simulate low light conditions.
Type II malfunction clearance in the dark
Type III Malfunction Clearance in the dark
In Battery Reload in the dark In battery = slide forward.
Out of Battery Reload in the dark Out of battery = slide locked to the rear.
Tactical Reload in the dark A tactical reload occurs when there is still ammunition in the magazine being removed from the gun.
Retrieve a rifle from the safe and fire one shot This drill should be timed.
Transition from rifle Simulate transition to pistol when rifle is no longer operable.


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Should you are going because of it?
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domain: finance


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THE WHITE House is said to be irked after the country's lead Coronavirus expert Anthony Fauci appeared to be "playing politics" during a recent interview.
Speaking to the Washington Post, Dr. Fauci said that Joe Biden's campaign was taking the pandemic "seriously from a public health perspective".
However, the doctor also claimed that Trump's campaign was "looking at a different perspective. Namely that of the economy and reopening the country."
Fauci added: "We're in for a whole lot of hurt. It's not a good situation.
"All the stars are aligned in the wrong place as you go into the fall and winter season, with people congregating at home indoors.
"You could not possibly be positioned more poorly".
Judd Deere, Deputy Press Secretary, and Deputy Assistant to Trump slammed Fauci's criticism of the President and called it "unacceptable".
"It's unacceptable and breaking with all norms for Dr. Fauci, a senior member of the President's Coronavirus Taskforce and someone who has praised President Trump's actions throughout this pandemic, to choose three days before an election to play politics," Mr. Deere said in a statement today.
He added: "As a member of the Task Force, Dr. Fauci has a duty to express concerns or push for a change in strategy, but he's not done that, instead choosing to criticize the President in the media and make his political leanings known by praising the President's opponent."
In response to Fauci's interview, current favorite of the president Scott Atlas posted on Saturday night to Twitter: "#Insecurity #EmbarrassingHimself #Exposed #CantThrowABall #NoTimeForPolitics"
Atlas, a neuroradiologist, has recently been favored by Trump because his guidance is more closely aligned with the President's own views which is to reopen the country and let the virus spread among healthy young people.
However Fauci disagrees.
"I have real problems with that guy," Fauci said.
"He's a smart guy who's talking about things that I believe he doesn't have any real insight or knowledge or experience in.
"He keeps talking about things that when you dissect it out and parse it out, it doesn't make any sense."
The president made the comments during a call with his campaign staff on October 19 that reporters got on.
Despite slamming the coronavirus expert, the president went on to say "Fauci is a nice guy" before saying "he's been here for 500 years."
During the call, Trump also insisted that if he had listened to Fauci's advice there would be "700,000, 800,000 deaths."
Trump also called Fauci a "disaster," who is a "bomb" when he goes on TV, but a "bigger bomb if you fire him."
"If there's a reporter on, you can have it just the way I said it. I couldn’t care less," the president said following the heated comments.
The coronavirus expert dubbed Trump's comments as a "distraction" and revealed he didn't want to get tangled in a “me against the president."
He told the Southern California radio station: "I would prefer not to comment on that and just get on with what we are really trying to do and what we are trying to do is to protect the health and welfare and safety of the American people predominantly and ultimately, of the world."
MORE TRUMP NEWS
Before quoting The GodFather, Fauci insisted that talking about coronavirus issues is "the only thing he really cares about."
Fauci then stated: "That other stuff, it’s like in 'The Godfather': Nothing personal, strictly business as far as I’m concerned.
"I just want to do my job and take care of the people of this country."


Subscriptions are the hot topic lately with three big-name titles opting to go with a subscription based revenue model. In today's Social Hub, we take a look at the potential impact that subscriptions have on today's games. Read on and then leave your thoughts in the comments.
Reading MMO discussions here and elsewhere, it’s common to see complaints about free to play and lists of reasons why subscription games have arguably better communities. Some will argue that subscriptions are good for keeping people out of a game, with assumptions about just who those people are and why they supposedly taint communities. They’re ‘poor’, they’re ‘kids’, they’re ‘newbs’, they’re “freeloaders”, they know nothing about MMOs, or any number of similar comments pop up across gaming communities around the internet.
Read more of Christina Gonzalez's The Social Hub: Do Subscriptions Make a Difference in Community?


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Wild Japan III: Nansei Shoto & Okinawa
Okinawa: The Little Known Sub-tropical Side
To the uninitiated, it is easy to imagine that Japan's four main islands of Hokkaido, Honshu, Shikoku and Kyushu constitute the entirety of the country. Yet that would be to ignore much that is special about the country - its plethora of islands and islets. Japan is truly the ultimate when it comes to island countries, with archipelagos within archipelagos, and with islands and islets galore.
Japan's southern extension is a separate archipelago in its own right - the Nansei Shoto. Justifiably defined as Asia's answer to the Galapagos, the numerous islands in the warm waters between Japan's southern island of Kyushu and the island of Taiwan are fascinatingly different from the rest of Japan.
The Nansei Shoto are astonishingly rich in natural history and provide opportunities for snorkeling, diving, wind-surfing and whale-watching. These though are not the only southern islands of Japan, for head south from Tokyo, out into the Pacific and there lie the Izu, Ogasawara (Bonin) and Iwo islands, the most remote parts of this widespread country.
The Natural Marvels of the Nansei Shoto
Japan's straggling southern archipelago, the Nansei Shoto, is so rich in both flora and fauna, and such a fine example of the effects of isolation that the islands have quite rightly been called the Asian Galapagos. There, the many forces of isolation have contributed to the evolution of many endemic species of plants, insects, birds and even mammals.
The largest of the islands in the chain is Okinawa, but it is far from being the only island of significance. The Nansei Shoto represents Japan's finger in the sub-tropical pie.
Where Hokkaido freezes for half of each year, the Nansei Shoto swelters. Here are flowers, butterflies and trees more commonly associated with the tropics. White coral sand beaches and intense sun add to the image.
Offshore, there are coral reefs with a myriad colourful fish; one may be lucky and find turtles too or even migratory whales here in these warm waters. The local vegetation includes ancient-looking cycads, and forest that is lush, and evergreen with broad glossy leaves. The wildlife here is very different from that in any other part of Japan.
Nansei Shoto Wildlife
Not all the islands share the same species, as the history of each is slightly different. These islands have had a fascinatingly chequered natural history. Connection and isolation have played their part here, such that the Kerama and Tokara straits, effectively divide the archipelago in to three parts.
In times past they have experienced long periods of isolation as islands, but when sea levels have fallen they have been connected to the continent. The northern section retained a connection with Kyushu, whereas the southern section retained a connection via Taiwan to the continent.
At other times, all islands have been connected, and at still other times all have been isolated as higher sea levels have separated them, not only into the islands that exist now, but into even smaller fragments.
When connected, species reached the islands from Asia and moved between the islands. When separated, during prolonged periods of isolation, species have diverged, evolved and unique endemic forms are the result.
Few of Japan's familiar mammals occur here, there are no squirrels, foxes, tanuki, or deer. Instead, the largest mammal is a small sub-species of the wild boar. There are other mammals on the islands though and among them are several endemic rodents such as the Ryukyu Spiny Rat, and Ryukyu Long-haired Rat, and the extraordinary forest-dwelling Amami Black Rabbit. The largest predator of the region, the Iriomote Wildcat, was only discovered as recently as 1965. It only lives on one small island and is no larger than a domestic cat.
Research has shown that the animals of the northern and southern islands of the Nansei Shoto are still genetically, closely related to those of the main islands of Japan, or of southern Asia, from which they have only recently diverged, but the animals living on the central islands of Okinawa and Amami tell a different story.
Genetic research has shown that the spiny and long-haired rats and the rabbit on Amami are so distinct that they are considered not only to belong to distinct species, but also to belong to distinct genera (the next highest category in which species are grouped). These species are living witnesses to the ancient isolation of these fascinating islands.
Birds such as the Cinnamon Bittern reach their northernmost limits here, while Japanese Macaques on Yakushima are at their southern limit. Still other species have evolved or survived in situ and are found no where else in the world, such as the Black Rabbit of Amami Island, and the rare Pryer's Woodpecker of northern Okinawa. New species are still being discovered in this hot-house of biodiversity, and in the early 1980s even a new bird, the Okinawa Rail, was described.
The Natural Marvels of the Izu and Ogasawara Islands
"Archipelagos within archipelagos" is perhaps the best way to sum up Japan's geography. In almost every direction one heads, there are not just islands, but strings of them.
Even metropolitan Tokyo consists of an island chain. On the mainland of Honshu is situated the huge urban island of Tokyo itself, but head south by ship and you can travel for a 1,000 km and more and yet still be within the official metropolitan area!
The first islands encountered are the Izu Islands, which are easily reached overnight by ship from Tokyo itself. Here the climate is warmer, more oceanic, the islands have a delightful world-in-miniature feel, and from a natural history perspective they are home to some unusual endemic species.
Approaching them early in the morning, islands such as Miyake-jima are encircled by swarms of seabirds, for these islands are the breeding haunts of hundreds of thousands of Streaked Shearwaters. The warm waters offshore are popular with dolphins making dolphin watching a distinct possibility, particularly off the island of Mikura.
Onshore, in the evergreen laurel forests that clad the flanks of the local volcanoes there are special birds such as the local Izu Islands Thrush and Ijima's Warbler, both of which can be seen easily seen on the islands of Miyake and Mikura.
Further south still there is a remote volcanic rock jutting from the sea known as Torishima - literally bird island. This spot on the planet is world-famous because each year the beautiful and exceedingly rare Short-tailed Albatross returns here to breed. From near extermination, early in the 20th century, concerted efforts by scientists, local government and conservationists have seen their numbers climb back in to the low hundreds and reach relative security once again.
The island chain does not end here though. Way beyond Torishima, and a 1,000 km south of central Tokyo, lie the Ogasawara Islands, also known as the Bonin Islands. These tropical pacific islands are a far cry from downtown Tokyo, though still linked by local administration and local telephone charges. In their extreme isolation they have few species of birds, though the Bonin Islands Honeyeater is endemic here, but for botanists Chichi-jima and Haha-jima are tropical island paradises.
The islands have now attracted fame as a superb whale-watching destination where Humpback and Sperm whales are both likely, and they offer excellent snorkeling and diving too, and as a place to relax and unwind in tropical warmth, then few places can beat the isolated Ogasawara Islands.

domain: travel