COLOR INFRARED DETECTING SET

• US 3,742,124 A
• Filed: 08/16/1971
• Issued: 06/26/1973
• Est. Priority Date: 08/16/1971
• Status: Expired due to Term

• Current Assignee: Charles B. Weaver, Jesse C. Wilson, Melvin J. Borel
• Original Assignee: Charles B. Weaver, Jesse C. Wilson, Melvin J. Borel
• Inventors: Wilson, Jesse C., Borel, Melvin J., Weaver, Charles B.
• Primary Examiner(s): Murray, Richard
• Application Number:
  US05/171,838
• Time in Patent Office: 680 Days
• Field of Search: 178/5.4R,5.2R,DIG.2 250/83.3H
• US Class Current: 348/33
• CPC Class Codes: H04N 9/43 Conversion of monochrome picture signals to colour picture signals for colour picture display

Abstract

A color infrared detecting set is provided which utilizes the variation of emissivity of objects to add the effect of color to the sensing and presentation format. With color added to brightness a large number of shade combinations are possible and a large visible distinction between objects is realized. Color image signals are obtained by infrared energy passing through filters of different wavelengths (for a range of detection interest) to corresponding detectors which convert the infrared energy to electrical signals. The electrical signals are amplified, weighted and summed in one channel to produce a brightness signal, and processed in another channel to produce a plurality of color-difference signals. The brightness signal drives a plurality of light modulators, and each light modulator receives a color perturbation signal derived from the colordifference signals to obtain a color signal representative of one of the tristimulus values. The color signals are combined to produce an image of brightness equal to a black and white image, but having an apparent hue.

Claims

1. A color infrared detecting set comprising:

a. an infrared receiver for receiving radiating energy from a source thereof and producing a plurality of electrical signals responsive to selected wavelengths;

b. a video signal processing and enhancement control means responsive to the plurality of electrical signals of the infrared receiver for selectively combining the plurality of electrical signals to produce a plurality of enhanced color signals; and

c. display means responsive to the enhanced color signals for producing a color image.

2. An apparatus according to claim 1 wherein the infrared receiver comprises a plurality of infrared filters defining regions for passing radiant energy of selected wavelengths, and a plurality of infrared detectors responsive to radiant energy passing the plurality of infrared filters for producing a corresponding plurality of electrical signals.

3. An apparatus according to claim 2, wherein the said filters define regions among the 8 to 14 micrometer wavelengths.

4. An apparatus according to claim 2, wherein said filters define three regions having wavelengths of about 8-10 micrometers, 10-12 micrometers, and 12-14 micrometers.

5. An apparatus according to claim 1, wherein the infrared detectors are low-energy-gap, high mobility materials of the group consisting of lead tin telluride, lead sulfide, indium antimonide, mercury cadmium telluride, and mercury doped germanium.

6. An apparatus according to claim 1, wherein said display means comprises a system for producing an image in real time responsive to the enhanced color signals of the signal processing and enhancement control means.

7. An apparatus according to claim 6, wherein said display Means includes a color picture producing plate.

8. An apparatus according to claim 1, wherein said display means comprises a system for producing a continuing color image.

9. An apparatus according to claim 8, wherein said display means comprises a plurality of light source means responsive to the enhanced color signals of the signal and enhancement control means for producing primary colors, and light mixing means responsive to the light from the plurality of light source means to combine the light for establishing a match with a given color to produce a color image.

10. An apparatus according to claim 9, wherein said plurality of light source means comprises color light emitting diodes responsive to the enhanced color signal output of the signal and enhancement control means.

11. An apparatus according to claim 9, wherein said plurality of light source means comprises a plurality of glow-tubes, and a corresponding plurality of visible color filters, each filter responsive to the light emitted by its corresponding glow-tube for producing a primary color.

12. An apparatus according to claim 11, wherein said light mixing means further comprises a light focusing means and a light sensitive display means, said light focusing means responsive to the combined light to focus the combined light on the light sensitive recording means, and said display means responsive to the focused mixed light for producing a color image.

13. A method of detecting infrared energy comprising the steps of:

a. receiving infrared energy from a source thereof;

b. converting the infrared energy to a plurality of electrical signals representative of selected wavelengths of the infrared energy;

c. processing by selectively combining the plurality of electrical signals to produce enhanced color signals from said plurality of electrical signals representative of selected wavelengths of the infrared energy, and d. producing from the enhanced color signals a color image of the source of infrared energy.

14. A method according to claim 13, wherein the step of receiving infrared energy from a source thereof comprises scanning the source of infrared energy with an optical system for collecting and focusing radiant energy.

15. A method according to claim 13, wherein the step of converting infrared energy to a plurality of electrical signals representative of selected wavelengths of the infrared energy comprises passing the radiant energy received from the source thereof through a plurality of radiant energy filters to a plurality of radiant energy detectors.

16. A method according to claim 15, wherein the radiant energy is passed sequentially through the plurality of radiant energy filters.

17. A method according to claim 13, wherein the step of processing enhanced color signals comprises amplifying the electrical signals of the detectors, summing the plurality of electrical signals for each of said plurality of radiant energy detectors to produce a signal indicative of the brightness of the source, selectively combining the plurality of signals to produce a plurality of color signals, and summing the signals to produce a plurality of enhanced color of signals.

18. A method according to claim 13, wherein the step of producing a color image of the source of infrared energy comprises converting the enhanced color signals to a plurality of visible colors and combining the colors to produce an image having a hue representative of the source of radiant energy.

19. A method according to claim 18 wherein the image is recorded on color film.

20. An apparatus according to claim 1, wherein said video signal processing and enhancement control system comprises a first signal processing channel operative to produce from the electrical signal output of the infrared receiver a signal to control the total brightness in the display means, and a second signal processing channel operative to produce, from the electrical signal output of the infrared receiver, color-difference signaLs, said first and second signal processing channels operatively coupled to produce the plurality of enhanced color signals for the display means.

21. An apparatus according to claim 20 wherein said video signal processing and enhancement control means comprises a plurality of preamplifiers having input terminals coupled to the detector outputs of the infrared receiver to amplify and balance the output signals of the plurality of detectors to produce signals and for alleviating the introduction of a hue signal with any change in temperature, and output terminals coupled to the first and second signal processing channels.

22. An apparatus according to claim 21 further comprising a delay means selectively coupled to preamplifiers of the plurality of preamplifiers for producing time coincident signals as the output signals of the plurality of preamplifiers.

23. An apparatus according to claim 20, wherein the first signal processing channel includes a summing amplifier, said summing amplifier responsive to the detector outputs of the infrared receiver for producing a signal indicative of the brightness of the source of energy.

24. An apparatus according to claim 20, wherein the second signal processing channel includes a plurality of identical circuits coupled to the detector outputs of the receiver, the first circuit of the plurality of circuits including a first signal inverting and signal noninverting means coupled to a first detector output of the receiver for producing an inverted signal and noninverted signal from the detector output;

a first signal summing means coupled to the signal noninverting output of the first signal inverting and noninverting means and coupled to the signal inverting output terminal of the first signal inverting and signal noninverting means of a second one of said plurality of circuits for combining the noninverted output signal of the first detector with the inverted output of a second detector;

a second signal inverting and signal noninverting means coupled to the output of the first summing means for producing inverted and noninverted signals from the output of the first summing means;

a second signal summing means having an input terminal coupled to the output of the first signal processing channel, an input terminal coupled to the noninverted output of the second signal inverting and noninverting means of the first circuit, and an input terminal coupled to the inverted ouput of a second signal inverting and noninverting means of a third circuit for selectively combining the total brightness signal of the first channel with the noninverted signal of the second signal inverting and noninverting means of the first circuit, and the inverted signal of the second signal inverting and noninverting means of the third circuit, to produce an enhanced color difference signal; and

a light source driver having one input terminal coupled to the output of the second signal summing means for receiving a color-difference signal, and a second input terminal for connection to a pedestal signal.