Abstract: The present invention relates to a low level, high resolution imager of the type comprising a light-amplifier tube (300) including a photocathode (310), at least one microchannel slab (330) serving as an electron amplifier, and a light-emitting phosphor screen (340) provided with a metal layer (342), an electron camera (400) comprising a photosensitive matrix array (410) suitable for transforming a received photon into an electron, and control means (700) for the electron camera, characterized by the fact that the control means (700) comprise an amplifier (710) responsive to the electrons collected on the metal layer (342) of the light-emitting phosphor screen (340) to control integration cycles of the photosensitive matrix array (410) in repetitive one-shot mode synchronized on the appearance of photons at the input of the light-amplifying tube (300).

Abstract: A direct conversion X-ray photo-electron cathode has specially designed secondary electron emission layers which provides high efficiency, low noise, high speed and broad band X-ray photon detection. The X-ray photocathode is integrated with a micro channel plate and an output phosphor display screen to form a panel type X-ray intensifier. The X-ray intensifier is combined with a micro-focus X-ray source to provide projection type X-ray microscope for use in X-ray microscopic diagnostic applications.

Abstract: A night sight for a missile launcher has an objective lens with a field of view of at least 22 degrees. The output image of the objective lens is intensified by a variable gain light intensifier tube and the output of the intensifier is viewed through an eyepiece. A reticle pattern etched on a glass substrate and filled with titanium dioxide is illuminated by adjustable brightness LED's positioned at points on the periphery of the substrate. The reticle is disposed between the light intensifier and the eyepiece and substantially duplicates the function of reticles used in daysights.

Abstract: A laser warning receiver (LWR) having an ability to not only detect a low power level laser source, such as a pulse train emitted by a laser beam rider, but to also provide a high angular resolution in determining the angle of arrival of that pulse train. The receiver includes a lens/filter arrangement for a large area photodetector to detect an incoming signal from an emitting source and a high gain amplifier to amplify the signal which is then applied to a synchronization generator that generates a digital pulse train with pulses corresponding to peaks in the incoming signal. The digital pulse train is applied to a code breaker where the code is analyzed and a further code is generated anticipating the arrival of further pulses in order to verify the code. That further code is applied to a time gate generator which generate a code, synchronized with the incoming signal, that controls the high voltage of a gated image intensifier which is coupled to a video camera.

Abstract: A streak camera having improved time resolving capacity in the femtosecond regime. The streak camera uses magnetic and/or electric fields in such a way as to minimize the adverse effects of angular distribution and energy distribution of photoelectrons simultaneously emitted from a photocathode in response to the impinging of light thereon.

Abstract: An improved photocathode for use in a night vision system, comprising a glass face plate, an AlInAs window layer having an anti-reflection and protective coating bonded to the face plate, an InGaAs active layer epitaxially grown to the window layer, and a chrome electrode bonded to the face plate, the window layer, and the active layer providing an electrical contact between the photocathode and the night vision system, whereby an optical image illuminated into the face plate results in a corresponding electron pattern emitted from the active layer.

Abstract: A method for fabricating a stripe color filter for the input of an image intensifier having a color-interpretive CCD output includes ascertaining CCD subpixel-to input coordinate correlation by test illumination with a positioning laser having low power. Based upon the correlation data assembled, light sensitive filter media, such as color tinted photoresist is exposed at those locations corresponding to like-color CCD subpixels. The media is then developed to form filter media. Subsequent coatings of photoresist of the next color are applied and exposed etc.

Abstract: A helmet-mounted night vision system that is compact, light in weight and ejection-safe. The system incorporates a night vision goggles apparatus for receiving incoming infrared and/or visible light from a viewed object and for converting the incoming light to an intensified visible light for presentation to an eye of a user, a visor mounted to a helmet to be worn by the user and adapted to be positioned in front of the night vision goggles apparatus, and connecting structure for connecting the visor to the night vision goggles apparatus for retaining the visor in position in front of the night vision goggles apparatus. By ensuring that the visor is safely retained in front of and substantially fully covers the goggles apparatus at all times, the system of the invention is rendered ejection-safe. The system also provides the user with numerous other structural and operational advantages.

Abstract: A feeble light measuring device comprising a photon counting tube, an image detector and a signal processor. The photon counting tube includes a photocathode for generating an electron upon an incidence of light to be measured, an MCP for multiplying the photoelectron from the photocathode and a phosphor screen for converting the photoelectrons multiplied by the MCP into a light image such as luminous spots. The MCP is not saturated by an incidence of single photoelectron. Thus the spread of the luminous spot corresponding to the single photoelectron is very small. The image detector converts the light image from the photon counting tube to electric outputs the signal processor removes noise components of the electric outputs from the image detector to extract signal components of the electric outputs.

Abstract: A image intensifier tube, having its brightness curve corrected in a simple way. The image intensifier tube comprises an input window (3), and an output window (4) at which the brightness is measured. The output window (4) bears a device for the attenuation of light (20), the opacity of this device being greater in a central zone (0) than it is towards the edges (21).

Abstract: A cathode-ray tube comprises an evacuated envelope which includes a faceplate panel joined to a funnel. A steel shrinkfit implosion protection band having a metallic protective coating thereon is fitted around the periphery of the panel to apply a compressive force thereto. The corrosion resistance of the band is enhanced by providing a metallic barrier layer between the steel band and the metallic protective coating.A method of forming the enhanced corrosion resistant band also is disclosed.

Abstract: A fiber optic viewing device has in a first embodiment, a color-preserving image intensifier positioned at the viewing end thereof. In a second embodiment, an input light source is sequentially modulated through a cycle of wavelength sets. The resulting image is intensified and recolored by an output recoloring filter which is synchronized with the input light modulation. In yet another embodiment, a set of red, green and blue LEDs are sequentially modulated by a controller to provide input light. A CCD camera receives the resultant intensified image and converts it to video format. A video processor stores frames during a cycle of modulation and then integrates the frames for viewing in full color.

Abstract: An image intensifier device for producing a color output image includes in a proximity focused intensifier tube, an RGB color filter matrix screen printed upon a glass wafer which is laminated to the input faceplate of the tube and sandwiched between the faceplate and the photocathode. The RGB matrix filters incident light into RGB components which are amplified by the tube. The output image is colorized in a first embodiment by passing white light fluorescing from a phosphor layer through an RGB output filter matrix which is functionally aligned in an operating tube with the input matrix. In a second embodiment, a UV emanating phosphor layer excites an RGB matrix of secondary phosphors. In a third embodiment, IR filters are included in the RGB input matrix and a narrow band output filter is assigned to represent IR information in the RGB output matrix. In a fourth embodiment a plurality of RGB phosphors replace the phosphor layer of the previous embodiments and directly fluoresce color information.

Abstract: For the acquisition of data for determining the duration and chirp (frequency modulation) of a single ultrashort laser radiation pulse said pulse is split into two partial pulses which are each conducted through one of two TREACY compressors having different group delay dispersions and then recorded in succession on the same time basis with a streak camera.

Abstract: Night vision apparatus, particularly night vision goggles, having a wide field of view. The apparatus includes an objective optical system having a selected field of view for collecting visible and/or infrared light from an object to be viewed and for providing an input image of the object; image intensifying and magnifying means for receiving the input image and for providing a visible, intensified and magnified output image of the input image, and an eyepiece optical system for receiving the visible, intensified and magnified output image and for presenting a visible intensified image of the object to an eye of a user at unity magnification. The image intensifying and magnifying means preferably comprises an image intensifier tube having a fiber optic bundle beam expander therein. The image intensifying and magnifying means permits the eyepiece optical system to have a longer focal length and, hence, to provide greater eye relief than would otherwise be possible.

Abstract: A color preserving image intensifier having synchronously reciprocating input and output multi-segmented, multi-color filter slides. To compensate for differences in exposure time of the segments of the filters arising from varying reciprocation velocity due, e.g. to sinusoidal motion, either the intensity of the output image is variably filtered or the intensifier gain is varied. In one embodiment, polarizing filters rotated in synchronicity with the reciprocation of the color preserving filters vary image intensity. In another embodiment, intensifier gain is varied based upon a velocity indicator.

Abstract: High quantum efficiency (.gtoreq.5%) ultrafast (.ltoreq.100 picosecond) and broad band (30 KeV to 80 KeV for medical application) X-ray photo-electron cathode, high gain X-ray real time image intensifier and portable low intensity real time projection type X-ray imagescope use new vacuum photo-electron devices. A new type X-ray photo-electron cathode has a specially designed alkali halide electron emission layer that makes possible high quantum efficiency, high speed and broad band X-ray photon detection. An X-ray photo-electron cathode followed by a direct coupled micro channel plate and an output phosphor display screen form a new type panel shaped direct view X-ray intensifier tube which can have both high spatial resolution (.gtoreq.10 lp/mm) and high gain (.gtoreq.10.sup.4). The thickness of this panel shaped disc X-ray intensifier can be less than 1 cm.

Abstract: In a streak tube wherein a photocathode and an acceleration electrode are disposed in confronting relation to each other for accelerating a photoelectron beam emitted from the photocathode, at least one of the photocathode and the acceleration electrode is formed on a strip-like electrode. A pulse voltage is applied to the strip-like electrode, whereby a very intensive pulsed electric field is developed between the photocathode and the acceleration electrode with the application of a relatively low pulse voltage. Interactive regions of the photocathode and the acceleration electrode are closely position with high accuracy. The streak tube can thus generate a streaked image with a very high time resolution without an increase in the background emission on a phosphor screen.

Abstract: An integrated LIDAR receiver includes a single detection element to provide both imaging and ranging functions. The single detection element includes an opaque photocathode, a microchannel plate (MCP) electron multiplier, and a phosphor coated anode covered with a metalized layer. The metalized layer on the phosphor anode allows electrons striking the anode to be detected as a prompt electrical current. The prompt electrical current is detected through a transformer that couples the anode to a power supply. The power supply biases the anode relative to the MCP and photocathode such that the MCP is grounded. The use of a transformer allows the prompt anode current to be detected without having to ground the anode, thereby simplifying the power supply circuitry. The detection of the prompt electrical current provides a first output signal useful for ranging information.

Abstract: The improved power supply of the present invention adjusts the voltages applied to an image tube to provide automatic brightness control and automatically compensate for temperature changes. A first oscillator, transformer and multiplier supply DC high voltage to a microchannel plate (MCP) electron multiplier of an image tube. The oscillator is controlled via control circuitry to modify the voltage applied to the MCP to automatically compensate for temperature changes associated with an image tube and to provide an automatic brightness control mode of operation. A second oscillator, transformer and individual multipliers are used to supply appropriate DC voltages to the cathode and screen of an image tube; these voltages are also automatically adjusted for temperature changes associated with the image tube. The screen current is detected and is used by additional control circuitry as feedback for the first oscillator to provide the automatic brightness control mode of operation.

Abstract: In a brightness intensifier tube there is provided, preferably in the exit screen or, in the case of a brightness intensifier comprising a channel plate intensifier, on an input electrode thereof, a fixed alignment marker, for example by local burning in of screen material by photoelectrons from the entrance screen which are liberated therefrom by irradiation by a laser beam. For tubes comprising a fixed entrance optical system the alignment marker is preferably provided by focused application of light via the optical system.

Abstract: There is disclosed a method for driving a photoelectric device comprising a photocathode, and controller for controlling electrons emitted from the photocathode, wherein gate voltages are applied respectively to the photocathode and the controller so that the electrons from the photocathode are not outputted from the controller.

Abstract: There is provided an improved night vision goggle having a housing containing an objective lens assembly, an image intensifier tube, a collimator assembly, a splitter member, and a pair of afocal telescopes. The optical axis of the afocal telescopes are offset from the optical axis of the collimator and objective lens assemblies. A pair of achromatic doublet lens assemblies are mounted side-by-side on the exit side of the collimator and near the entrance pupils of the telescopes. The optical axes of the doublet lens assemblies are coaxial with the optical axes of the telescopes. The achromatic doublet lens assemblies thus collect light from a sub-diameter, decentered aperture of the collimator assembly, and correct axial chromatic aberration in the telescopes.

Abstract: An integrated LIDAR receiver includes a single detection element to provide both imaging and ranging functions. The single detection element includes an opaque photocathode, a microchannel plate (MCP) electron multiplier, and a phosphor coated anode covered with a metalized layer. The metalized layer on the phosphor anode allows electrons striking the anode to be detected as a prompt electrical current and used as a first output signal to provide ranging information. Visible light (photons) is also output from the anode in response to electrons striking the phosphor in the anode, and is used to provide an intensified image of a scene. The visible light may thereafter be detected by an imaging sensor, such as a CCD camera. The phosphor anode is biased at ground potential. A transimpedance amplifier is coupled to the metalized layer on the phosphor anode and, with the anode being at ground potential, operates with a virtual null input.

Abstract: The invention relates to an X-ray imaging system, comprising an X-ray image intensifier tube in which the electron-optical system can be adjusted to a number of different image formats. By making the image format increase or decrease visibly on the exit screen in the event of a change of image format, annoying visual adjustment effects are avoided and a patient can be continuously observed also in the event of a change of format. Because of the gradual high-voltage variation of the power supply for the electron-optical system, associated with a visible variation of the image format, the output resistance of the power supply circuit may be high. Furthermore, due to the gradual change of the mean intensity on the exit screen of the X-ray image intensifier tube, the control behavior of the automatic exposure control and the automatic gain control of the X-ray imaging system are influenced in a positive sense.

Abstract: An X-ray detector including a photocathode arranged to receive X-ray radiation and being operative to provide in response thereto an output of electrons, and at least one electron multiplier operative at subatmospheric pressure and in response to the output of electrons from the photocathode to provide an avalanche including an increased number of electrons.

Abstract: To permit in-flight inspection of an aircraft engine, an imager views the front of the engine, and includes an image intensifier which is gated on and off at the engine speed. Small variations about the engine speed may be used to sweep all the blades into the field of view of an imager which does not view the whole of the front of the engine.

Abstract: An X-ray imaging tube comprising an vacuum envelope, and input screen located in the input end of the envelope, an output screen located in the output end of the envelope, an anode located in the output end of the envelope, and a plurality of beam-converging electrodes located in the envelope and arranged along the inner surface of the envelope. The tube has an magnification of used input field size of 2.3 or more. The components of the tube have such positions and sizes, thus satisfying the following relations:3.5.ltoreq.G3.sub.D /A.sub.D .ltoreq.5.0-3.65.times.MAG+1.00.ltoreq.G3.sub.L /L.ltoreq.-3.65.times.MAG+1.05where L is the distance between the input and output screens, A.sub.D is the inside diameter of the anode or one of the beam-converging electrodes set at the same potential as the anode, which is closer to the input screen than any other beam-converging electrodes set at the same potential as the anode, G3.sub.

Abstract: Time-dependent information such as light whose intensity varies with time is converted into positional information representing the change of the time-dependent information. A series of photoelectrons provided as the time-dependent information are accelerated or decelerated when passing through a region defined by first and second electrode to which a ramp voltage is applied so that the photoelectrons are accelerated or decelerated and are released at speeds varying depending on times. A speed analyzer analyzes the speeds of the photoelectrons and provides the positional information. The positional information is applied to a phosphor screen on which the positions of the photoelectrons applied thereto are displayed. The positions thereof represents the times involved with the photoelectrons.

Abstract: An apparatus for electrically insulating viewing windows in an image intensifier tube is disclosed. The mechanical parts which are located close to the window are electrically insulated with the metal parts being held at a high voltage and electrically insulated on the outside of the image intensifier by an insulating screen. The insulating screen includes electrically conductive layer 36 and an insulating layer 37 which separates the metal parts 20, 26 from the conductive layer. The conductive layer also forms an equipotential layer which is opposite the metal parts and thereby "freezes" the distribution of the electrical lines of force in the insulating screen 35.

Abstract: A night vision apparatus 10 includes a first focusing refracting lens 28 which focuses light rays 29 from distant scene 14 onto a light intensifier 30. The kinoform 40 or bifringent lens 78 are disposed in the light path to allow light rays 35 from near scene 18, 20, 22 and 24 to be focused onto light intensifier 30 to form a multi-focus night vision apparatus with increased depth of focus.

Abstract: When sampling light and light to be measured each having a wavelength longer than an upper wavelength limit of the sensitivity of a photocathode are incident on the photocathode of a multiphoton absorption-type electron tube, light-light sampling is enabled by two-photon absorption and one-photoelectron emission. A delaying unit adjusts an incident timing of the sampling light from an optical pulse generating unit on the elctron tube in synchronism with an incident timing of the light to be measured on the electron tube. A half mirror causes the sampling light and the light to be measured to coincide on the photocathode of the electron tube. A controlling unit controls the delaying unit to sequentially shift the incident timing of the sampling light on the electron tube.

Abstract: An X-ray imaging tube which comprises a vacuum envelope, an input screen comprising a substrate located in the input end of the envelope, an input phosphor layer formed on the substrate and comprising a number of columnar phosphor crystals, and a photoelectric layer formed directly or indirectly on the input phosphor layer, an anode and an ouput screen located in the output end of the envelope, and a beam-converging electrode located in the envelope and extending along the inner surface of the envelope. The tube further comprising optically opaque layers which are formed in each columnar crystal and extending from the surface thereof.

Abstract: A detector for the image brightness which is present at the output screen of an x-ray image intensifier is formed by a combination of individual detector elements, the detector elements having different shapes and/or sizes. The detector elements in combination form a matrix which enables an optimum selection of a desired measurement field by selecting defined combinations of individual detector elements.

Abstract: An image intensifier tube is provided with a channel plate. The channel plate's channels are open both at the cathode side and at the anode side. A high frequency alternating electric field is generated in the space between the cathode and the channel plate. Thereby during a first period of the cycles of the alternating electric field the photoelectrons emitted by the photocathode traverse the space between the photocathode and the channel plate. During a second period of the cycles of the alternating electric field, in which second periods the polarity of the electric field is reversed with respect to the polarity during the first period, any ions that may have emerged from the channels into the space between the photocathode and the channel plate are drawn back to the channel plate.

Abstract: A color image intensifier device combines an image intensifier tube providing monochrome output with input and output color members each having a plurality of color portions for passing respective different light frequencies. The input color member filters the incoming light to the tube for each light spectrum band in timed succession, and the monochrome output of the tube passes through the output color menber to produce a corresponding color component output. The color component outputs are perceived by the eye as a complete color image if the timed modulation of the incoming image is above the threshold level for flicker. In a mechanical version, the color members are input and output color wheels rotated in tandem at the input and output ends of the image intensifier tube. The filter members may also be arranged in the form of linearly reciprocating slides or planes movable in two dimensions. The color members can also be stationary filters which change color by electronic control.