Color night vision goggles capable of providing anti-jamming protection against pulsed and continuous wave jamming lasers

• US 5,756,989 A
• Filed: 11/22/1996
• Issued: 05/26/1998
• Est. Priority Date: 11/22/1996
• Status: Expired due to Term

• Current Assignee: Regents of the University of California (University of California)
• Original Assignee: Mcdonnell Douglas Corporation (The Boeing Co.)
• Inventors: Bear, Philip D., Walrath, Larry C.
• Primary Examiner(s): Allen, Stephone B.
• Application Number:
  US08/755,213
• Time in Patent Office: 550 Days
• Field of Search: 250/207, 250/214 VT, 250/216, 250/226, 313/525-528, 348/216, 348/217
• US Class Current: 250/214.0VT
• CPC Class Codes: A61F 9/022 Use of special optical filters, e.g. multiple layers, filters for protection against laser light or light from nuclear explosions, screens with different filter properties on different parts of the screen; Rotating slit-discs optical filters per se G02B5/20
• CPC Class Codes: G02B 23/125 head-mounted
• CPC Class Codes: H01J 31/56 for converting or amplifying images in two or more colours

Abstract

Color night vision goggles (NVG), e.g., binocular-style or monocular-style NVG, which include at least one channel. Each channel includes an objective lens for receiving input radiant energy from a low-luminance scene within the field-of-view of the NVG, an input tunable electro-optical filter positioned in front of the objective lens, an image intensifier device for amplifying input radiant energy transmitted by the input electro-optical filter and the objective lens, and for generating output radiant energy which constitutes an amplified image of the low-luminance scene, an eyepiece lens, an output tunable electro-optical filter disposed between the image intensifier device and the eyepiece lens, and a control circuit for generating a control signal having a prescribed frequency. The input and output electro-optical filters sequentially and synchronously transmit successive ones of a plurality of different spectral bands (e.g., the blue, green, and red color bands) of the input and output radiant energy, respectively, in response to the control signal, during each successive cycle of the control signal, whereby a viewer can perceive a full-color image of the low-luminance scene when looking through the eyepiece lens. The prescribed frequency of the control signal is preferably sufficiently high to ensure that the full-color image is flicker-free. The color NVG are preferably further provided with a gated power supply for supplying current to the image intensifier device, a detector for detecting laser light that may enter the field-of-view of the NVG and for producing a train of electrical output pulses in response to detection of laser light, even when the detected laser light is generated by a continuous wave laser, and a pulse-following circuit responsive to the train of electrical output pulses produced by the detector for producing a corresponding train of gating pulses. The gated power supply is responsive to the gating pulses for selectively interrupting the current supplied by the gated power supply in synchronism with the detected laser pulses, to thereby protect the color NVG from all possible jamming laser threats.

Claims

1. Color night vision goggles, comprising:

at least one channel, each said channel including;

an objective lens for receiving input radiant energy from a low-luminance scene within a field-of-view of the goggles;

an input tunable electro-optical filter positioned in front of said objective lens;

image intensifier means for amplifying portions of said input radiant energy transmitted by said input electro-optical filter and said objective lens, and for thereby producing an amplified electron image of the low-luminance scene;

display screen means for generating output radiant energy constituting an amplified visible image of the low-luminance scene, in response to said amplified electron image;

an eyepiece lens;

an output tunable electro-optical filter disposed between said display screen means and said eyepiece lens;

a control circuit for generating a control signal having a prescribed frequency;

wherein said input electro-optical filter and said output electro-optical filter sequentially and synchronously transmit successive ones of a plurality of different spectral bands of said input and output radiant energy, respectively, in response to said control signal, during each successive cycle of said control signal, whereby a viewer can perceive a full-color image of the low-luminance scene when looking through said eyepiece lens.

2. The color night vision goggles as set forth in claim 1, wherein said prescribed frequency of said control signal is sufficiently high to ensure that said full-color image is flicker-free.

3. The color night vision goggles as set forth in claim 2, wherein said prescribed frequency of said control signal is in the range of between 20 Hz-180 Hz.

4. The color night vision goggles as set forth in claim 1, wherein said image intensifier means comprise an image intensifier device which includes:

an image intensifier tube having a first face upon which said portions of said input radiant energy transmitted by said input electro-optical filter are incident, said image intensifier tube having a photocathode composed of a photosensitive material which releases electrons in response to said input radiant energy incident upon said first face; and

,

a microchannel plate provided with a multiplicity of microchannels through which pass said electrons released by said photosensitive material of said photocathode, whereby said electrons which pass through said microchannels stimulate the emission of a cascade of additional electrons, to thereby produce said amplified electron image of the low-luminance scene.

5. The color night vision goggles as set forth in claim 4, wherein said display screen means comprises a phosphor-coated second face of said image intensifier tube.

6. The color night vision goggles as set forth in claim 1, wherein said plurality of different spectral bands of said input radiant energy comprise first, second, and third spectral bands I1, I2, and I3, respectively, and said plurality of different spectral bands of said output radiant energy comprise blue, green, and red color bands, respectively.

7. The color night vision goggles as set forth in claim 6, wherein:

said first spectral band I1 of said input radiant energy is transmitted by said input electro-optical filter during a first time interval;

said second spectral band I2 of said input radiant energy is transmitted by said input electro-optical filter during a second time interval;

said third spectral band I3 of said input radiant energy is transmitted by said input electro-optical filter during a third time interval;

said blue color band of said output radiant energy is transmitted by said output electro-optical filter during said first time interval;

said green color band of said output radiant energy is transmitted by said output electro-optical filter during said second time interval; and

,

said red color band of said output radiant energy is transmitted by said output electro-optical filter during said third time interval.

8. The color night vision goggles as set forth in claim 7, wherein said control signal comprises a ramp-shaped voltage waveform.

9. The color night vision goggles as set forth in claim 1, wherein said ramp-shaped control signal comprises a ramp-shaped voltage waveform.

10. The color night vision goggles as set forth in claim 1, wherein said at least one channel comprises first and second substantially parallel channels.

11. The color night vision goggles as set forth in claim 1, further comprising:

a gated power supply for supplying current to said image intensifier means; and

,

an anti-laser jamming subsystem which selectively interrupts said current supplied by said gated power supply in synchronism with radiant energy from a pulsed or continuous wave jamming laser source within the field-of-view of the goggles.

12. The color night vision goggles as set forth in claim 1, further comprising:

a gated power supply for supplying current to said image intensifier means; and

,

an anti-laser jamming subsystem which includes;

detector means for detecting input radiant energy which lies within a particular one of said different spectral bands of said input radiant energy and which has a magnitude greater than a prescribed threshold, and for producing a detection signal in response thereto;

means for selectively interrupting said current supplied by said gated power supply in synchronism with the transmission of said particular one of said different spectral bands of said input radiant energy by said input electro-optical filter, in response to said detection signal.

13. The color night vision goggles as set forth in claim 12, wherein said input radiant energy which lies within a particular one of said different spectral bands of said input radiant energy and which has a magnitude greater than a prescribed threshold, includes laser light generated by a continuous wave laser.

14. The color night vision goggles as set forth in claim 1, further comprising:

a gated power supply for supplying current to said image intensifier means; and

,

a detector for detecting laser light that may enter the field-of-view of the goggles and for producing a train of electrical output pulses in response to detection of laser light, even when the detected laser light is generated by a continuous wave laser;

a pulse-following circuit responsive to said train of electrical output pulses produced by said detector for producing a corresponding train of gating pulses; and

,

wherein said gated power supply is responsive to said gating pulses for selectively interrupting said current supplied by said gated power supply in synchronism with the detected laser pulses.

15. Color night vision goggles, comprising:

at least one channel, each said channel including;

an objective lens for receiving input radiant energy from a low-luminance scene within a field-of-view of the goggles;

an input tunable electro-optical filter positioned in front of said objective lens;

an image intensifier device for receiving and amplifying input radiant energy transmitted by said input electro-optical filter and said objective lens, and for generating output radiant energy which constitutes an amplified visible image of the low-luminance scene;

an eyepiece lens;

an output tunable electro-optical filter disposed between said image intensifier device and said eyepiece lens;

a control circuit for generating a control signal having a prescribed frequency;

wherein said input electro-optical filter and said output electro-optical filter sequentially and synchronously transmit successive ones of a plurality of different spectral bands of said input and output radiant energy, respectively, in response to said control signal, during each successive cycle of said control signal, whereby a viewer can perceive a full-color image of the low-luminance scene when looking through said eyepiece lens.

16. The color night vision goggles as set forth in claim 15, wherein said prescribed frequency of said control signal is sufficiently high to ensure that said full-color image is flicker-free.

17. The color night vision goggles as set forth in claim 15, wherein said plurality of different spectral bands of said input radiant energy comprise first, second, and third spectral bands I1, I2, and I3, respectively, and said plurality of different spectral bands of said output radiant energy comprise blue, green, and red color bands, respectively.

18. The color night vision goggles as set forth in claim 17, wherein:

said first spectral band I1 of said input radiant energy is transmitted by said input electro-optical filter during a first time interval;

said second spectral band I2 of said input radiant energy is transmitted by said input electro-optical filter during a second time interval;

said third spectral band I3 of said input radiant energy is transmitted by said input electro-optical filter during a third time interval;

said blue color band of said output radiant energy is transmitted by said output electro-optical filter during said first time interval;

said green color band of said output radiant energy is transmitted by said output electro-optical filter during said second time interval; and

,

said red color band of said output radiant energy is transmitted by said output electro-optical filter during said third time interval.

19. The color night vision goggles as set forth in claim 15, wherein said at least one optical channel comprises first and second substantially parallel optical channels.

20. The color night vision goggles as set forth in claim 15, further comprising:

a gated power supply for supplying current to said image intensifier device; and

,

a detector for detecting laser light that may enter the field-of-view of the goggles and for producing a train of electrical output pulses in response to detection of laser light, even when the detected laser light is generated by a continuous wave laser;

a pulse-following circuit responsive to said train of electrical output pulses produced by said detector for producing a corresponding train of gating pulses; and

,

wherein said gated power supply is responsive to said gating pulses for selectively interrupting said current supplied by said gated power supply in synchronism with the detected laser pulses.