Invisible light beam projector and night vision system

Abstract

A relatively large diameter, sharply focused beam of invisible light is produced by a projector (10) for the purpose of lighting up a person, object, etc. to be viewed at night. The projector (10) is used in conjunction with a night vision telescope (12) which includes a light intensifier (88). The projector (10) includes a pulsating infrared LED, or a laser diode, adapted to produce a high intensity narrow beam of invisible light. This beam of invisible light is enlarged by a projection lens assembly (26) adapted to sharply focus the light into a collimated light beam of about the diameter of the projector housing (20). The light source (30) is pulsed on and off, and is on only about 10-20% of the time. When on it is illuminated by a high level current which would quickly burn out the light (30) if operated continuously. The intermittent operation of the light (30) at high current produces a nonflickering high intensity light beam. The projection lens (26) enlarges this beam and clearly focuses it, to produce a relatively large illuminating beam having a substantially large range of use.

What is claimed is: 
     
       1. An invisible light beam projector, comprising: a tubular body having a forward end and a rearward end; an invisible light beam emitting diode having an emitting lens;   mounting means inside of said tubular body mounting the diode at a location within the body, between the two ends of the body, with the lens of the diode directed towards the forward end of the body;   control circuit means for .Iadd.causing .Iaddend.the diode .[.adapted.]. to be repetitiously charged and discharged, and on each discharge causing the diode to light and transmit a narrow beam of invisible light through the emitting lens towards the forward end of the tubular body.Iadd., .Iaddend.said control circuit means functioning to turn the diode on and off at a rate resulting in the diode being on between about 10-20% of the time and off during the remainder of the time, and when on being powered by a current that is substantially larger than the diode could stand if on continuously; and   projection lens means within the tubular body, forwardly of the diode, of a type which is always in focus in a range between a predetermined minimum distance from the light projector and infinity, said projection lens means being positioned and adapted to receive the narrow beam of invisible light from the diode lens and enlarge and collimate this light into a collimated beam of invisible light in sharp focus, to produce a lighting spot having a sharp and definite edge.   
     
     
       2. An invisible light projector according to claim 1, comprising a tubular carrier within said tubular body, said mounting means being in the form of an end wall at an end of the tubular carrier. 
     
     
       3. An invisible light projector according to claim 2, wherein said control circuit means is housed within the tubular carrier. 
     
     
       4. An invisible light projector according to claim 3, wherein said control circuit means comprises a circuit board which extends diametrically within the tubular carrier. 
     
     
       5. An invisible light projector according to claim 1, wherein said circuit means is located within said tubular body between the rearward end of the body and the mounting means for the diode, control switch means for turning the control circuit means on and off, located outside of said tubular body, and conductor means connecting the control switch to the control circuit means. 
     
     
       6. An invisible light projector according to claim 5, wherein the tubular body includes an end wall at the rearward end of the tubular body, and said conductor means comprises a two component connector, one of said components being mounted on the end wall. 
     
     
       7. An invisible light projector according to claim 1, wherein said control circuit means comprises battery means located within said tubular body between the rearward end of the body and the mounting means for the diode. 
     
     
       8. An invisible light projector according to claim 7, wherein said control circuit means also comprises a circuit board which extends diametrically within the tubular body, and wherein the battery means is positioned radially outwardly from the circuit board. 
     
     
       9. An invisible light projector according to claim 1, comprising a tubular carrier within said tubular body, and wherein said control circuit means is housed within the tubular carrier and the control circuit means includes battery means. 
     
     
       10. An invisible light projector according to claim 9, wherein said control circuit means comprises a circuit board which extends diametrically within the tubular carrier and the battery means is positioned radially outwardly of the circuit board. 
     
     
       11. An invisible light projector according to claim 1, wherein the projection lens means comprises a periscopic lens mounted within the tubular body towards the forward end of the tubular body, and a meniscus lens mounted within the tubular body substantially immediately rearwardly of the periscopic lens, said meniscus lens being smaller in diameter than said periscopic lens. 
     
     
       12. An invisible light projector according to claim 11, wherein the lens on the LED is a simple meniscus lens. 
     
     
       13. An invisible light projector according to claim 12, comprising a tubular carrier within said tubular body, adjacent the rearward end of the tubular body, said mounting means being in the form of an end wall at the inner end of the tubular carrier, and wherein the control circuit means is housed within the tubular carrier, between said mounting means and the rearward end of the tubular body. 
     
     
       14. An invisible light projector according to claim 1, wherein the control circuit means comprises battery means for producing a current, transistor means between the battery means and the diode, and integrated circuit means including a capacitor for triggering the transistor means, so that the transistor means functions as a switch to ultimately transmit and interrupt current flow from the battery means to the diode. 
     
     
       15. An invisible light projector according to claim 1, wherein the diode is an infrared LED. 
     
     
       16. An invisible light projector according to claim 1, wherein the diode is a laser diode. 
     
     
       17. A night vision system comprising: an invisible light beam projector comprising:   a tubular body having a forward end and a rearward end;   an invisible light beam emitting diode having an emitting lens;   mounting means inside of said tubular body mounting the diode at a location within the body, between the two ends of the body, with the lens of the diode directed towards the forward end of the body;   control circuit means for .Iadd.causing .Iaddend.the diode .[.adapted.]. to be repetitiously charged and discharged, and on each discharge causing the diode to light and transmit a narrow beam of invisible light through the emitting lens toward the forward end of the tubular body.Iadd., .Iaddend.said control circuit means functioning to turn the diode on and off at a rate resulting in the diode being on between about 10-20% of the time and off during the remainder of the time, and when on being powered by a current that is substantially larger than the diode could stand if on continuously; and   projection lens means within the tubular body, forwardly of the diode, of a type which is always in focus in a range between a predetermined minimum distance from the light projector and infinity, said projection lens means being positioned to receive the narrow beam of invisible light from the diode lens and collimate and focus this light into a collimated, sharp focused beam of invisible light, to produce a lighting spot having a sharp and definite edge; and   a night vision telescope positioned adjacent to said invisible light projector and comprising an objective lens, and an image intensifier means positioned to receive an optical image from the objective lens, said telescope having a line of sight that is substantially parallel to the beam of invisible light.   
     
     
       18. A night vision system according to claim 17, comprising a tubular carrier within said tubular body, said mounting means being in the form of an end wall at an end of the tubular carrier. 
     
     
       19. A night vision system according to claim 18, wherein said control circuit means is housed within the tubular carrier. 
     
     
       20. A night vision system according to claim 19, wherein said control circuit means comprises a circuit board which extends diametrically within the tubular carrier. 
     
     
       21. A night vision system according to claim 17, wherein said circuit means is located within said tubular body between the rearward end of the body and the mounting means for the diode, control switch means for turning the control circuit means on and off, located outside of said tubular body, and conductor means connecting the control switch to the control circuit means. 
     
     
       22. A night vision system according to claim 21, wherein the tubular body includes an end wall at the rearward end of the tubular body, and said conductor means comprises a two component connector, one of said components being mounted on the end wall. 
     
     
       23. A night vision system according to claim 17, wherein said control circuit means comprises battery means located within said tubular body between the rearward end of the body and the mounting means for the diode. 
     
     
       24. A night vision system according to claim 23, wherein said control circuit means also comprises a circuit board which extends diametrically within the tubular body, and wherein the battery means is positioned radially outwardly from the circuit board. 
     
     
       25. A night vision system according to claim 17, comprising a tubular carrier within said tubular body, and wherein said control circuit means is housed within the tubular carrier and the control circuit means includes battery means. 
     
     
       26. A night vision system according to claim 25, wherein said control circuit means comprises a circuit board which extends diametrically within the tubular carrier and the battery means is positioned radially outwardly of the circuit board. 
     
     
       27. A night vision system according to claim 17, wherein the projection lens means comprises a periscopic lens mounted within the tubular body towards the forward end of the tubular body, and a meniscus lens mounted within the tubular body substantially immediately rearwardly of the periscopic lens. 
     
     
       28. A night vision system according to claim 27, wherein the lens on the LED is a simple meniscus lens. 
     
     
       29. A night vision system according to claim 28, comprising a tubular carrier within said tubular body, adjacent the rearward end of the tubular body, said mounting means being in the form of an end wall at the inner end of the tubular carrier, and wherein the control circuit means is housed within the tubular carrier, between said mounting means and the rearward end of the tubular body. 
     
     
       30. A night vision system according to claim 17, wherein the control circuit means comprises battery means for producing a current, transistor means between the battery means and the diode, and integrated circuit means including a capacitor for triggering the transistor means, so that the transistor means functions as a switch to ultimately transmit and interrupt current flow from the battery means to the diode. 
     
     
       31. A night vision system according to claim 17, wherein the diode is an infrared LED. 
     
     
       32. A night vision system according to claim 17, wherein the diode is a laser diode. 
     
     
       33. An invisible light beam projector, comprising: a tubular body having a forward end, a rearward end and a center axis;   a single invisible light beam emitting diode having an emitting lens;   mounting means inside of said tubular body mounting the diode at a location within the body, between the two ends of the body, with the lens of the diode on said center axis, directed towards the forward end of the body;   control circuit means for .Iadd.causing .Iaddend.the diode .[.adapted.]. to be repetitiously charged and discharged, and on each discharge causing the diode to light and transmit a narrow beam of invisible light through the emitting lens towards the forward end of the tubular body.Iadd., .Iaddend.said control circuit means functioning to turn the diode on less than it is off, and when on being powered by a current that is substantially larger than the diode could stand if on continuously; and   projection lens means within the tubular body, forwardly of the diode, of a type which is always in focus in a range between a predetermined minimum distance from the light projector and infinity, said projection lens means being positioned and adapted to receive the narrow beam of invisible light from the diode lens and enlarge and collimate this light into a collimated beam of invisible light in sharp focus, to produce a lighting spot having a sharp and definite edge.   
     
     
       34. A night vision system, comprising: an invisible light beam projector comprising:   a tubular body having a forward end, a rearward end and a center axis;   a single invisible light beam emitting diode having an emitting lens;   mounting means inside of said tubular body mounting the diode at a location within the body, between the two ends of the body, with the lens of the diode on said center axis directed towards the forward end of the body;   control circuit means for .Iadd.causing .Iaddend.the diode .[.adapted.]. to be repetitiously charged and discharged, and on each discharge causing the diode to light and transmit a narrow beam of invisible light through the emitting lens towards the forward end of the tubular body.Iadd., .Iaddend.said control circuit means functioning to turn the diode on less than it is off, and when on being powered by a current that is substantially larger than the diode could stand if on continuously; and   projection lens means within the tubular body, forwardly of the diode, of a type which is always in focus in a range between a predetermined minimum distance from the light projector and infinity, said projection lens means being positioned to receive the narrow beam of invisible light from the diode lens and collimate and focus this light into a collimated, sharp focused beam of invisible light, to produce a lighting spot having a sharp and definite edge; and   a night vision telescope positioned adjacent to said invisible light projector and comprising an objective lens, and an image intensifier means positioned to receive an optical image from the objective lens, said telescope having a line of sight that is substantially parallel to the beam of invisible light. .Iadd.35. A device for illuminating a target with a beam of radiation in an invisible portion of the electromagnetic spectrum to enhance the quality of an image of a target produced by a passive visible light intensifier and image enhancer, said device comprising: a housing; a source of said electromagnetic radiation in said housing; and a lens system in said housing and aligned with said source for forming the energy emitted from said source into a beam with a well defined peripheral edge. .Iaddend. .Iadd.36. A device for illuminating a target as defined in claim 35 in which said lens system includes a meniscus lens and a periscopic lens assembly aligned with, spaced from, and on the downstream side of said meniscus lens, said meniscus lens being sufficiently smaller in diameter than said periscopic lens assembly to enable said lens system to produce a beam of electromagnetic energy with a well defined peripheral edge as aforesaid. .Iaddend. .Iadd.37. A device for illuminating a target as defined in claim 35 which has: an elongated casing housing said source of electromagnetic radiation and said lens system in an optically aligned, spaced apart relationship; a power source for said electromagnetic radiation source housed in said tubular casing; and means for controlling the operation of said source of electromagnetic radiation, said control means including an operator manipulatable switch which is accessible from the exterior of said casing. .Iaddend. .Iadd.38. A system for enhancing the visibility of a target under low light level conditions, said system comprising: a passive visible light intensifier and image enhancer capable of providing a visible image of the target without illumination of the target at levels of light which are too low for wanted details of the target to be discernible to the naked eye; a device for illuminating only a selected area of the target with a focused beam of electromagnetic radiation which has a well defined peripheral edge and is invisible to the naked eye but is usable by said image enhancer to provide an ostensibly continuous image of the selected area of the target that appears brighter to a user of the system than the rest of the target in the field of view of the image enhancer; and operator-engageable switch means for so activating said device that said system can be employed in a first mode with the target illuminating device inactivated to provide an image of the target obtained by the intensification of visible light falling on the target and in a second mode with said device activated to provide an image of said target as aforesaid with an enhanced view of that selected area of the target illuminated by the beam of invisible   
     
     
        electromagnetic radiation projected from said device. .Iaddend. .Iadd.39. A system as defined in claim 38 in which the device for illuminating the target also includes: an elongated casing housing said source of electromagnetic radiation and said lens system in an optically aligned, spaced apart relationship; a power source for said electromagnetic radiation source housed in said tubular casing; and means for controlling the operation of said source of electromagnetic radiation, said control means including an operator manipulatable switch which is accessible from 
     
     
        the exterior of said casing. .Iaddend. .Iadd.40.  A system for enhancing the visibility of a target under low light level conditions, said system comprising: a passive visible light intensifier and image enhancer capable of providing a visible image of the target without illumination of the target at levels of light which are too low for wanted details of the target to be discernible to the naked eye and a selectively activatable device for illuminating only a selected area of the target with a beam of electromagnetic radiation which is invisible to the naked eye but is usable by said image enhancer to provide an obtensibly continuous image of the selected area of the target that appears brighter to a user of the system than the rest of the target in the field of view of the image enhancer, whereby said system can be employed in a first mode with the target illuminating device inactivated to provide an image of the target obtained by the intensification of visible light falling on the target and in a second mode with said device activated to provide an image of said target as aforesaid with an enhanced view of that selected area of the target illuminated by the beam of electromagnetic radiation projected from said device, the device for illuminating the target with a beam of electromagnetic radiation to enhance the quality of the selected area of the image comprising: a housing, a source of said electromagnetic radiation in said housing, and a lens system in said housing and aligned with said source for forming the energy emitted from said source into a beam with a well defined peripheral edge. .Iaddend. .Iadd.41. A system as defined in claim 40 in which the lens system of the device for illuminating the target with a beam of electromagnetic radiation includes a meniscus lens and a periscopic lens assembly aligned with, spaced from, and on the downstream side of said meniscus lens, said meniscus lens being sufficiently smaller in diameter than said periscopic lens assembly to enable said lens system to produce a beam of electromagnetic energy with a 
     
     
        well defined peripheral edge as aforesaid. .Iaddend. .Iadd.42.  A hand held system for enhancing the visibility of a target under low light level conditions, said system comprising: an elongated casing housing a passive, visible light intensifier and image enhancer; a device fixed to and extending in the same direction as said casing for illuminating only a related area of said target with a beam of electromagnetic which is invisible to the naked eye; a handle for supporting said image enhancer casing, said target illuminating device including an electrically powered electromagnetic radiation source and means for forming the energy emitted from said source into a beam with a well defined peripheral edge and said system further comprising operator-controllable means which enables said system to be employed in a first mode with the target illuminating device inactivated to provide an image of the target obtained by the intensification of visible light falling on the target and in a second mode with said device activated to provide an image of said target as aforesaid with an enhanced view of that selected area of the target illuminated by the beam of electromagnetic radiation projected from said device, said target illuminating device further comprising an electrical control circuit for activating and deactivating said source and said operator-controllable means comprising a switch for controlling the source activating and deactivating operation of said circuit and a trigger means supported from and accessible from the exterior of the handle which is displaceable by a user of the system to open and close said switch. 
     
     
        .Iaddend. .Iadd.43.  A system as defined in claim 42 in which the device for illuminating the target also includes: an elongated casing housing said source of electromagnetic radiation and a lens system in an optically aligned, spaced apart relationship; a power supply source for said electromagnetic radiation source housed in said tubular casing; and means for controlling the operation of said source of electromagnetic radiation by connecting said electromagnetic radiation source to said power supply, said control means including an operator manipulatable switch which is 
     
     
        accessible from the exterior of said casing. .Iaddend. .Iadd.44.  A system as defined in claim 43 which includes means so operatively connecting said device-associated switch and said handle-associated switch to the remainder of the control means of said device that either of said switches can be closed to turn on the source of electromagnetic radiation. 
     
     
        .Iaddend. .Iadd.45.  A hand held system for enhancing the visibility of a target under low light level conditions, said system comprising: an elongated casing housing a passive, visible light intensifier and image enhancer; a device fixed to and extending in the same direction as said casing for illuminating only a related area of said target with a beam of electromagnetic radiation which is invisible to the naked eye; a handle for supporting said image enhancer casing, said target illuminating device including an electrically powered electromagnetic radiation emitter, an electrical control circuit for activating and deactivating said source, a housing, a source of said electromagnetic radiation in said housing, and a lens system in said housing and aligned with said source for forming the energy emitted from said source into a beam with a well defined peripheral edge, and said system further comprising a switch for controlling the source activating and deactivating operation of said electrical control circuit and a trigger means supported from and accessible from the exterior of the handle which is displaceable by a user of the system to open and close said switch. .Iaddend. .Iadd.46. A system as defined in claim 44 in which the lens system of the device for illuminating the target with a beam of electromagnetic radiation includes a meniscus lens and a periscopic lens assembly aligned with, spaced from, and on the downstream side of said meniscus lens, said meniscus lens being sufficiently smaller in diameter than said periscopic lens assembly to enable said lens system to produce a beam of electromagnetic energy with a well defined edge as aforesaid. .Iaddend.