Abstract: A proximity-type image intensifier tube has an entrance screen which includes a photocathode which is substantially insensitive to light of wavelengths above 500 nm, and an exit screen having a phosphor layer having a substantial emissivity of notably red light having a wavelength of at least 550 nm. Consequently, optical radiation produced by the exit screen does not produce disturbing feedback radiation from the photocathode. This avoids the need for a reflecting metallic layer on the phosphor layer, as has heretofore been required in order to prevent feedback radiation.

Abstract: An integrated optical system illuminates an ultraviolet spatial detector with an image from a field of interest. The ultraviolet spatial detector is comprised of an electron multiplying microchannel plate and a 100 pixel discrete anode array using a high strip current microchannel plate. The discrete anode array preserves the spatial distribution of the image. The ultraviolet spatial sensor has a wide field of view. The ultraviolet spatial detector has a photon counting sensor capable of detecting ultraviolet sources to determine their position to within plus or minus 4.5 degrees.

Abstract: The invention employs a reverse biased zener diode in the output circuit of a single stage or multistage electron multiplier. In a multistage device, a bypass resistor is employed between stages for increasing the bias current in downstream stages which operates at reduced potential whereby power dissipation is minimized.

Abstract: Night vision goggles that is internally modified such as to provide a reatic simulator without activation of any night vision enhancement and includes a depth perception loss. An assembly is positioned after the objective assembly on the same optical axis for the transfer of the focused incoming light, which light is also color filtered. A fiber optic rod achieves the transfer of the focused incoming light without any use of an image intensifier tube.

Abstract: A night vision visor system that is compact, light in weight, and ejection-safe, and which provides the user with an unobstructed peripheral field of view and other structural and operational advantages. The night vision visor system includes a visor adapted to be mounted to a helmet to be worn by a user and to be positioned substantially in front of the user's face, and a night vision imaging apparatus mounted to the visor for receiving incoming visible and/or infrared light from an object, for converting the incoming light to an intensified visible light, and for presenting the intensified visible light to an eye of the user. The night vision imaging apparatus includes first and second night vision imaging devices mounted in openings in the visor and movable with the visor between a down position in front of the user's face when is use and a raised position away from the user's face when not in use.

Abstract: Reticle apparatus that is affixed to the output surface of an image intensifier tube fiber optic element in a night vision goggle system. One embodiment provides for an illuminated reticle pattern. The reticle pattern is etched into a glass substrate which is then filled by a light reflective material. At least one light emitting diode (LED) is positioned adjacent to the edge of the substrate. Light from the LED is then received by the edge of the substrate which then illuminates the reticle pattern. An alternate embodiment provides for a reticle pattern that is affixed to an output surface of a fiber optic element wherein the output surface is curved. The reticle pattern is formed on a clear, flexible substrate that is able to conform the curvature of the output surface. The substrate is affixed to curved output surface by an adhesive that is coated on the flexible substrate.

Abstract: An improved electrostatically-focused image intensifier tube, and a night vision device having such a tube, is substantially free of the spurious bright spots generally known as "PC Flash". The improved image intensifier tube includes an insulator which resists emission of electrons into the interior cavity of the tube, or a structure to capture such emitted electrons before they can fall into a microchannel plate of the tube and cause the PC Flash. A method of making such an image intensifier tube is also disclosed.

Abstract: A self contained protective shutter assembly for an imager eye piece inclng an eyecup, a powered shutter, switch, power supply and interface coupling.

Abstract: A night vision device with improved user safety includes a head gear support structure which suspends a night vision viewer relative to the head and eyes of the user. The head gear includes a flip up mount allowing the user to flip the night vision viewer up and out of the user's line of sight for an unobstructed natural view of the environment. In order both to save battery power, and to prevent the user from inadvertently revealing his position by forgetting to turn off the night vision viewer before flipping it up, the support structure includes a magnetic flux source cooperable with a magnetically-responsive switch of the night vision viewer to maintain the viewer turned on only when the viewer is in its use position. When the viewer is flipped toward its upward position, the switch of the viewer is carried out of magnetic association with the flux source so that the viewer shuts off.

Abstract: The gain uniformity of sealed microchannel plate image intensifiers (MCPIs) is improved by selectively scrubbing the high gain sections with a controlled bright light source. Using the premise that ions returning to the cathode from the microchannel plate (MCP) damage the cathode and reduce its sensitivity, a HeNe laser beam light source is raster scanned across the cathode of a microchannel plate image intensifier (MCPI) tube. Cathode current is monitored and when it exceeds a preset threshold, the sweep rate is decreased 1000 times, giving 1000 times the exposure to cathode areas with sensitivity greater than the threshold. The threshold is set at the cathode current corresponding to the lowest sensitivity in the active cathode area so that sensitivity of the entire cathode is reduced to this level. This process reduces tube gain by between 10% and 30% in the high gain areas while gain reduction in low gain areas is negligible.

Abstract: An overload protection circuit for a photomultiplier tube. A light source illuminates a photomultiplier tube which produces a signal proportional to the incoming radiation which is sent to photon counting electronics. The photon counting electronics produces a signal in proportion to the input photons to the photomultiplier tube and also provides an output to a frequency to voltage converter. The frequency to voltage converter is used to modulate a high voltage amplifier which controls the output of the photomultiplier tube. When the photon counting electronics indicate to the frequency to voltage converter that the photons produced by the photomultiplier tube exceed a predetermined maximum the high voltage amplifier reduces the gain of the photomultiplier tube. The gain of the photomultiplier tube is gradually reduced in proportion to the incident light level.

Abstract: A circuit for high resolution decoding of multi-anode microchannel array detectors consisting of input registers accepting transient inputs from the anode array, anode encoding logic circuits connected to the input registers, midpoint pipeline registers connected to the anode encoding logic circuits and pixel decoding logic circuits connected to the midpoint pipeline registers. A high resolution algorithm circuit operates in parallel with the pixel decoding logic circuit and computes a high resolution least significant bit to enhance the multi-anode microchannel array detector's spatial resolution by halving the pixel size and doubling the number of pixels in each axis of the anode array. A multiplexer is connected to the pixel decoding logic circuit and allows a user selectable pixel address output according to the actual multi-anode microchannel array detector anode array size.

Abstract: A monocular night vision apparatus employing an infrared energy spectrum source of illumination and a camera lens and night vision image intensifier combined receiver apparatus into a small hand-held portable package that is both low in cost and reliable in nature is described. The night vision transmitter apparatus includes a laser diode energy source that is coupled to an aperture controlled and focus controlled optical system and driven by an electronic closed-loop feedback energization circuit which employs self-contained battery sources of energy. Multiple operating modes and operating intensities of the light source are provided through a plurality of signal inputs to the closed feedback loop of the laser diode energy source. Disturbance of the closed feedback loop by reflected energy within the optical transmitter apparatus is precluded by the use of feedback prevention optical alignment in the transmitter's optical system.

Abstract: An object of this invention is to provide an imaging device which can output distinct images which are not blurred. According to this invention, photoelectrons emitted from a photocathode (2) during a gate period in which a low potential change is given to the photocathode have set energy different from that of photoelectrons during the other period, and are incident on an energy filter (9). Only photoelectrons of the set energy pass through the energy filter (9). The photoelectrons which have passed through the energy filter during a gate period advance to an output surface (3).

Abstract: A microchannel plate (MCP)-based detector of reduced size employs a flexible multilayer printed circuit board as a lead assembly and enjoys increased ease of assembly and improved versatility.

Abstract: An active night vision system capable of viewing a target over long distances utilizes laser illumination in eye-safe, invisible wavelength regions of about 1.52-1.76 .mu.m or about 2.03 .mu.m-2.34 .mu.m for illuminating a target; and electronically receives, intensifies and displays or stores the reflected image.

Abstract: An image intensifier 18 is comprised of an evacuated chamber, an input surface 16 having a florescent material thereon for converting incident radiation into a visible light representative of the incident radiation, a photocathode layer 20 disposed closely adjacent the input surface for emitting a cloud of free electrons 22 into the evacuated chamber in proportion to the intensity of visible light at each point thereon, and an output surface 26 having a scintillating material thereon for converting electrons impinging thereon into a relatively bright light image proportional to the electron energy at each point on the output surface said light image having a first aspect ratio. An electrical potential 24 accelerates the free electrons from the photo-cathode to the output surface. A fiber optic bundle 28 comprised of an input face, positioned outside the chamber to view the bright light image at the output surface, and an output face 34 is provided.

Abstract: A night vision device with a modular assembly includes an image intensifier module or assembly, which includes an image intensifier tube and a power supply. The image intensifier tube receives low-level light from a scene too dark to be viewed with the unaided eye, and provides a visible representative image of the scene in phosphor yellow/green light. The power supply receives low-voltage power from a source, such as a battery, and provides power at voltages appropriate for operation of the image intensifier tube. The module includes a separable high-voltage connector for electrically connecting the power supply to the image intensifier tube. According to a preferred embodiment of the invention, the connector includes structure for physically connecting the power supply and image intensifier tube in separable nested relationship while also providing environmental protection to electrical connector features of the module.

Abstract: An X-ray image amplifier tube designed with an input screen having a photocathode and with a detection screen which is opposite the latter and a short distance away for detection of a photo-electron beam which is generated by X-ray input image signals and is amplified in the tube. The detection screen is provided with a conversion coating for converting an image-carrying photo-electron beam into a potential excursion and to this end contains, for example, an amorphous selenium coating or a porous KCl coating. A variable potential can be applied both over the vacuum gap between the photocathode and the conversion coating and over the conversion coating itself and, as a result of this, high image brightness dynamics can be achieved without image disruption.

Abstract: A low cost image intensifier tube is provided which has an improved vacuum sealing mechanism and improved optical transmission. Glass windows on both the input and output of the tube are vacuum sealed within the housing by a ring of indium that contacts the interface between each of the windows and the housing. A pair of raised pointed flanges each positioned along the inner housing surface interfacing the windows protrude into the adjacent ring of indium for improving the vacuum seal of both input and output windows and for controlling the spacing of the elements within the tube. Sealing the photocathode from the rest of the tube is a ceramic cathode cork. The cathode cork is a solid sealing ring press fit within the tube housing and colocated between the input window at the outer edge of the photocathode and the microchannel plate.

Abstract: In an X-ray image intensifier tube an entrance section is optimized in respect of image quality, optical aberrations and efficiency. To achieve this, notably in order to avoid photocathode charging phenomena, a separating layer having an adapted electrical transverse conduction is provided. In order to reduce scattered radiation, an edge portion of the entrance screen is deactivated for relevant examinations. In order to increase efficiency, use is made of a double phosphor layer having different X-ray absorption properties. In order to compensate for vignetting a radial variation of the thickness or of the radiation properties of a separating layer or of the luminescent layer itself is used.

Abstract: The invention is directed to an x-ray image intensifier having an evacuated housing, an input luminescent screen, electron optics, and an image sensor applied inside the housing at that side thereof lying opposite the input luminescent screen. The side of the image sensor facing toward the input luminescent screen is provided with a layer system that includes at least one semiconductor layer that effects an electron conversion of the incident electrons by ionization with charge carrier multiplication and is composed of amorphous semiconductor material.

Abstract: A light-weight night vision device includes a housing carrying an objective lens through which low-level light from a scene to be viewed is received. The housing carries an image intensifier tube receiving the low-level light from the objective lens, and providing in response an image representative of the scene. An eye piece carried by the housing provides a user of the device with an view of the representative image. The housing includes a light-weight portion which both carries the objective lens and partially houses the image intensifier tube. This light-weight housing portion also serves to shield the image intensifier tube from radio frequency and electrostatic interference.

Abstract: The invention relates to an ultrarapid camera for visualizing the intensity profile of a laser pulse. This camera comprises in vacuum housing a photocathode, an extraction grid, focalization electrodes, deflection plates and a visualization screen. According to the invention, the electron emitting photocathode is constituted by at least one metal tip (3, 12) and means (9, 10) are provided to send said laser pulse (13) into a zone situated in front of said tip.

Abstract: An X-ray image intensifier includes an envelope having an input window consisting of an aluminum alloy, and an input phosphor screen arranged in the envelope to oppose the input window, and including a substrate, an input phosphor layer formed on the substrate, and a photocathode formed on the input phosphor layer, wherein the aluminum alloy contains 3 to 6 wt % of Mg and 0.01 to 0.5 wt % of Zr. This aluminum alloy may further contain at least one metal element selected from the group consisting of 0.1 to 1 wt % of Mn, 0.01 to 0.5 wt % of Cr, 0.01 to 0.5 wt % of Sc, and 0.01 to 0.05 wt % of Ti.

Abstract: A microchannel plate (MCP) apparatus and method in which the output metalization layer or electrode is covered with a thin coating to reduce the number of spurious electron emissions striking the phosphor screen or other collection anode in an image intensifier. Microchannel plates manufactured in this way have the beneficial effect of improving yield in the manufacture of night vision devices.

Abstract: An ionizing radiation converter 10 comprises a vacuum tight enclosure 12; a cathode 16; an anode 18 defining a pinhole 20 and comprising an output phosphor layer facing away from the cathode; and focusing electrodes 26 and 30. The focusing electrodes, anode and cathode, in use, force photoelectrons, emitted by the cathode as a result of input ionizing radiation, to move through the pinhole, and back to the anode, so that the photoelectrons impinge on the output phosphor layer to provide an intensified signal representative of the input radiation.

Abstract: An x-ray image intensifier has an evacuated housing, an input luminescent screen, electron optics, and an image sensor disposed inside the housing at a side of the housing opposite the input luminescent screen. The image sensor is covered by a protective layer which effects a deceleration of the incident electrons, the protective layer being applied on that side of the image sensor facing the input luminescent screen.

Abstract: A night vision device with a holographic reticle ordinarily provides a user with all image of a night time scene unimpaired by any reticle pattern. Such a reticle pattern can interfere with night time observations, or may be distracting to the user. Consequently, the utility of the night vision device for use by observers is improved. However, when the holographic reticle is activated, the user is provided with a clearly visible reticle pattern superimposed on the night time scene. The reticle pattern may be used, for example, to estimate ranges to objects observed, or to aim a weapon.

Abstract: An image intensifier tube that utilizes a photoresponsive layer for producing electrons in response to received radiation, a solid state electron amplifier for multiplying the electrons produced by the photoresponsive layer, a cold cathode for emitting electrons into vacuum, and a phosphor screen for converting impinging electrons into a visible image. The solid state electron amplifier is formed as a semiconductive layer interposed in between a photoresponse layer and a negative electron affinity layer on the photocathode. The solid state electron amplifier receives the electrons produced by the photoresponsive layer, multiplies the electrons and directs the electrons to the negative electron affinity layer. The negative electron affinity layer then directs the electrons through a vacuum to the phosphor screen producing a viewed image.

Abstract: A night vision device with an infrared light usable for covert signaling and reading as well as for illumination of exceedingly dark areas where sufficient ambient light does not exist for the night vision device to provide a view of the area, includes a singular dual-action control switch which allows an operator of the night vision device to operate all of the functions of the device with a singular control. These functions include momentary illumination of the infrared light for signaling and for "quick look" purposes, such as for updating a user's knowledge of map coordinates, for example. The control circuit also allows the infrared light to be maintained on for area illumination, for example, until the user purposely turns it off.

Abstract: An X-ray imaging tube has an input phosphor screen including a substrate, a discontinuous phosphor layer formed on the substrate, and a continuous phosphor layer formed on the discontinuous phosphor layer. The discontinuous phosphor layer consists of a large number of columnar crystals separated from each other and containing a substance for absorbing light emitted from a phosphor upon incidence of an X-ray. Light-absorbing layers containing a compound of the substance and having a concentration of the element higher on outer surfaces thereof than that in interiors thereof are formed on adjacent side surfaces of the columnar crystals such that the light-absorbing layers are not present at an interface between the discontinuous phosphor layer and the continuous phosphor layer. The gap between the adjacent side surfaces of the columnar crystals is 0.1 .mu.m or more.

Abstract: The disclosure relates to image intensifier tubes of the proximity focusing type, wherein it especially concerns the positioning of a primary screen with respect to a slab of microchannels. An image intensifier tube comprises a sealed chamber containing a primary screen and a slab of microchannels. The slab of microchannels is fixed to the body of the chamber. According to one characteristic, the primary screen is fixed to the slab, from which it is kept at a distance by means of at least one insulating shim. The result thereof is greater precision and greater uniformity of the spacing between the primary screen and the slab of microchannels.

Abstract: The photocathode of an image intensifier is pulsed ON and OFF at a rate determined by a thyristor or SCR having the anode to cathode path coupled to the photocathode and the gate electrode triggered by a variable resistor, capacitor (RC) circuit to cause the photocathode to draw or conduct current only during the OFF interval of the SCR. During the ON interval of the SCR, the photocathode is OFF or non-conducting, wherein the controlled image intensifier tube exhibits a relatively constant resolution over a wide range of input light input values as from 10.sup.-6 to 10.sup.1 foot-candles.

Abstract: Process to correct distortion of radiological images by obtaining the image of a regular test chart and assessing the distortions to which the image is subjected. This assessment is used to correct normal images obtained with the installation. One obtains automatically the distortion corrections to be applied to the image elements by eliminating (55) the image background by creating (63) images of similar columns, by labelling (66) the columns detected and by calculating (71) the co-ordinates of the intersections of these columns. The calculation of the intersection co-ordinates is improved by replacing (89) these columns by straight segments whose position is calculated by a regression of least error squares over all the image elements belonging to this column and situated near this intersection. Preferably, all these calculations should be made through implementing mathematical morphology operations.

Abstract: An exit section of an X-ray image intensifier tube, including an the exit phosphor screen, exit window and basic optical system, is optimized so as to achieve a high light yield, low optical aberration and a high resolution. The exit window notably has a pre-compensation geometry for curvature of the image plane of the basic optical system, or the exit window an interference filter, or the exit phosphor layer contains a layer of a comparatively slow phosphor in addition to a layer of a customary phosphor in order to achieve noise-suppressing image integration.

Abstract: An imaging device comprising a vacuum vessel, an electron source arranged in the vessel and a solid-state image sensor arranged to receive signal electrons emitted from the electron source. The solid-state image sensor comprises a charge transferring device, picture element electrodes, an electron multiplier layer, and a surface electrode layer. The picture element electrodes are connected to the charge transferring device and cover the major part of this device. The surface electrode layer and the electron multiplier layer are stacked on the picture element electrodes. The surface electrode layer formed on the electron multiplier layer transmits the incident signal electrons to the electron multiplier layer.

Abstract: An X-ray image intensifier tube includes a scintillator screen for converting ionizing radiation into light radiation or near-visible radiation, a microchannel array for achieving electron multiplication, and a photoelectrode positioned directly on an input face of the microchannel array. The input face of the microchannel array is coated with an electrically conductive layer which directly contacts the photocathode. The present design eliminates strict spacing requirements between the photocathode and the microchannel array and allows the photocathode and the microchannel array to operate at a single potential rather than requiring separate potentials. The requirement of a separate support for the scintillator screen is also obviated since the scintillator screen is formed on the input face of the microchannel array.

Abstract: A method of providing near simultaneous night vision and communication including directing a narrow voice modulated IR laser beam at a distant receiver/demodulator during communication periods, causing the IR laser beam to diverge substantially during scene viewing periods, other than the data communication periods, for illuminating a darkened scene which includes the laser beam receiver, and viewing the darkened scene with an IR viewing device.

Abstract: The disclosure relates to radiological image intensifier tubes, and more particularly to means to improve the image resolution of these tubes and/or correct their brightness curve at output. The image intensifier tube comprises an input screen comprising a scintillator borne by an aluminium substrate. A porous layer of alumina is interposed between the scintillator and the substrate. The alumina layer is dyed so as to absorb the light emitted by the scintillator towards the substrate.

Abstract: A buffer assembly for a gamma-insensitive gas avalanche focal plane array operating in the ultra-violet/visible/infrared energy wavelengths and using a photocathode and an avalanche gas located in a gap between an anode and the photocathode. The buffer assembly functions to eliminate chemical compatibility between the gas composition and the materials of the photocathode. The buffer assembly in the described embodiment is composed of two sections, a first section constructed of glass honeycomb under vacuum and a second section defining a thin barrier film or membrane constructed, for example, of Al and Be, which is attached to and supported by the honeycomb. The honeycomb section, in turn, is supported by and adjacent to the photocathode.

Abstract: An imaging system comprised of a source of penetrative radiation 14, an image intensifier tube 18 and a video camera 38 is provided. The intensifier tube is comprised of a input screen 22 and an output screen 24. The intensifier tube converts radiation 20 impinging on the input screen into a visible light image 36 on the output screen 24. The video camera is operatively positioned to view the output screen of the intensifier. A light sampler 50 is operatively disposed in the visible light path between the image intensifier output screen 24 and the video camera input 38. The light sampler is comprised of a mirror 52, a focusing lens 54, a beam splitter 56, an aperture 58, a light source 78, a photo receptor 60 and an optical aligner 64.

Abstract: Method and apparatus for measuring the time of short events, such as characteristics of a source of short radiation pulses or lifetime of excited states of a sample. The method and apparatus is based on a multi-step photoemission process from an active element target exhibiting superlinear photoemission. A short prompt radiation pulse is used to raise electrons to an excited state, and a following overlapping short probe pulse is used to raise the excited electrons to the vacuum level where they leave the sample, changing its charge state. The number of escaped electrons is measured as a function of the time delay between the prompt and probe pulses to provide the sought after information. Preferably, the charged target is suspended or supported in an electric field, and the voltage needed to restore the charge-changed target to its original position is used.

Abstract: A mounting assembly for a night vision system is provided which allows the night vision system to be easily and rapidly switched from one eye to the next. The night vision system has an optical portion, and a control housing affixed to the optical portion. The control housing has a first and a second mounting plate. The mounting assembly has a first and a second carriage, and each of the carriages are configured to receive a selected one of the mounting plates. The mounting assembly can then be secured to either a face mask worn by the operator, or a helmet worn by the operator. The position of the carriages can be adjusted to compensate for the inter-pupillary distance and elevation relative a normal line of sight of an operator's eyes. The carriages are carried by a threaded rod having two portions threaded in opposite directions, so that rotation of the knob moves the carriages either closer together or further apart, as desired.

Abstract: A large area video camera is suitable for high energy imaging applications. The sensor-target of the camera tube is composed of TlBr, TlI, PbI.sub.2, or PbBr.sub.2 or a two layer structure comprising CsI and a photoconductive layer of materials such as amorphous silicon, amorphous selenium, cadmium sulphide, antimony trisulfide or antimony sulphide oxysulphide. A disclosed tube incorporates various modifications for dealing with problems associated with stray capacitance, premature electron leakage and secondary electron emission.

Abstract: The present invention is an image intensifier assembly that includes a Generation III image intensifier tube and an inverter lens arrangement, such that the present invention image intensifier assembly can be substituted for a Generation II image intensifier tube in a given application. The inverter lens arrangement is adjustably positionable relative to the Generation III image intensifier tube so the image relayed can be focused to optimize the resolution of the complete tube assembly.

Abstract: An electron emission element comprises a P-type semiconductor substrate and electrodes formed on both ends of the semiconductor substrate. A voltage is applied between said electrodes. The P-type semiconductor substrate is irradiated with light to emit the electrons, generated in the P-type semiconductor substrate by photoexcitation, from an electron emitting face at an end of the P-type semiconductor substrate.

Abstract: A photon emitting high speed event detector provides for the optimum detection and location of high speed events such as strobe light sources, pulsed laser, gunfire, and lightning. The detector includes a focal plane array, a control circuit and a cueing sensor. The focal plane array is capable of receiving and storing photons which are emitted from a device. The focal plane array is continuously switched by the control circuit between an integrate (charging) and non-integrate (clearing) state until a high speed event is detected by the cueing sensor. During the charging state, incident photon energy is stored by the focal plane array. Upon detection of an event, the cueing sensor instructs the control circuit to hold the focal plane array in the integrate state and the control circuit reads out the stored charge which can be provided to a video monitor for display.

Abstract: In an X-ray image intensifier tube, a casing for the protection from x-radiation from the X-ray image intensifier tube. The casing according to the present invention comprises a jacket of a thermoplastic material charged with a powder of a material that absorbs the x-radiation and a shielding from outside magnetic fields. The shielding is in contact with the jacket. The screen that absorbs the x radiation thus is at least partially formed of the jacket.

Abstract: An X-ray detector has a transmission type intensifying screen provided on the X-ray incident area of the detector body and a reflection type intensifying screen provided on the inner wall surface of the detector body except for the X-ray incident area. Visible rays from the transmission type intensifying screen and the reflection type intensifying screen are detected by a photomultiplier installed in the detector body. The transmission type intensifying screen and the reflection type intensifying screen use fluorescent materials such as Gd.sub.2 O.sub.2 S:Tb; Gd.sub.2 O.sub.2 S:Tb, Ce; GD.sub.2 O.sub.2 S:Tb, Yb; Gb.sub.2 O.sub.2 S:Pr; BaFCl:Eu; BaFBr:Eu; La.sub.2 O.sub.2 S:Tb; La.sub.2 O.sub.2 S:Tb, Ce; La.sub.2 O.sub.2 S:Tb, Yb; La.sub.2 O.sub.2 S:Pr; Y.sub.2 O.sub.2 S:Tb; Y.sub.2 O.sub.2 S:Tb, Ce; Y.sub.2 O.sub.2 S:Tb, Yb; and Y.sub.2 O.sub.2 S:Pr.