INTENSITY MODULATED LASER IMAGERY DISPLAY

• US 3,571,493 A
• Filed: 10/20/1967
• Issued: 03/16/1971
• Est. Priority Date: 10/20/1967
• Status: Expired due to Term

• Current Assignee: Charles E. Baker, Jack J. Burch
• Original Assignee: Charles E. Baker, Jack J. Burch
• Inventors: Baker, Charles E., Burch, Jack J.
• Application Number:
  US04/676,786
• Time in Patent Office: 1,243 Days
• US Class Current: 353/85
• CPC Class Codes: G02B 27/46 Systems using spatial filters
• CPC Class Codes: G02F 1/0121 Operation of devices; Circuit arrangements, not otherwise provided for in this subclass
• CPC Class Codes: H04N 9/3129 scanning a light beam on the display screen scanning a light beam on a screen in displays other than projection devices G09G3/02; scanning systems in general G02B26/10; projectors using laser light sources in general H04N9/3161

Abstract

Apparatus for producing a display of imagery including a laser generating a high-intensity collimated light beam which is intensity modulated by means of a light modulator and caused to sweep the image area by a light scanner. After the sweeping light beam passes through the imagery, it is focused by means of a condensing lens and partially reflected by means of a beam splitter to a light-sensitive detector. A signal generated by the detector is amplified and characterized into a control signal for the light modulator. Light passing through the beam splitter is focused by a projection lens on a display raster.

Claims

1. Apparatus for reproducing imagery for display comprising:

laser means for generating a high-intensity collimated light beam to illuminate said imagery and means for optically projecting the data therein to a display surface;

modulating means responsive to a control signal for varying the intensity of the collimated light beam;

scanning means for sweeping said light beam in a pattern across said imagery; and

light responsive means sensitive to at least a portion of the light intensity transmitted through said imagery for generating a control signal to said modulating meaNs proportional to the intensity of the modulated scanned light beam.

2. Apparatus for reproducing imagery as set forth in claim 1 further including a beam splitter positioned after said modulator and scanner for reflecting said portion of the modulated scanned light beam to said light responsive means.

3. Apparatus for reproducing imagery as set forth in claim 2 wherein said light responsive means includes a light detector and a feedback amplifier, said light detector generating a signal to said feedback amplifier having an output signal connected to said modulating means.

4. Apparatus for reproducing imagery for display comprising:

laser means for generating a high-intensity collimated light beam to illuminate said imagery and transmit the data therein to a display surface;

modulating means responsive to a control signal for varying the intensity of the collimated light beam;

scanning means for sweeping said light beam in a pattern across said imagery;

beam splitter means positioned after said modulator and scanner for reflecting a portion of the modulated scanned light beam; and

light responsive means sensitive to said portion of the light intensity transmitted from said beam splitter means for generating a control signal to said modulating means proportional to the intensity of the modulated scanned light beam, said light responsive means including a light detector and feedback amplifier.

5. Apparatus for reproducing imagery as set forth in claim 27 wherein the moving light spot at said display surface has a spot size on the order of about 1/2000 of the display surface.

6. Apparatus for reproducing imagery as set forth in claim 27 wherein the intensity of the light beam at said display surface is given by the equation:

I2 TIoTo / 1+TIok where T is the light intensity transmission of the imagery;

Io is the laser light beam intensity;

To is the light intensity transmitted through said modulating means with zero feedback signal; and

K is a constant.

7. Apparatus for producing an intensity modulated display of imagery comprising:

a laser generating a high-intensity collimated light beam to illuminate said imagery and transmit the data therein to a display surface;

a light modulator for varying the intensity of the laser light beam in accordance with a feedback signal;

a light deflector for moving the modulated laser light beam across said imagery;

a condensing lens in optical relationship with the modulated deflected light beam for generating the Fourier transform of said imagery;

a projection lens for focusing the modulated light beam on said display surface; and

light responsive means sensitive to at least a portion of the light intensity transmitted through said imagery for generating a feedback signal to said light modulator proportional to the modulated scanned intensity of said laser light beam.

8. Apparatus for producing an intensity modulated display as set forth in claim 7 further including a beam splitter positioned after said modulator and scanner for directing said portion of the modulated scanned laser beam to said light responsive means.

9. Apparatus for producing an intensity modulated display as set forth in claim 8 wherein said light responsive means includes a light-sensitive detector and a feedback amplifier, said detector generating an input signal to said feedback amplifier having an output signal connected to said light modulator.

10. Apparatus for producing an intensity modulated display as set forth in claim 7 including a spatial frequency filter positioned in the modulated light beam at the reimaging plane of said condensing lens to filter the data transmitted from said imagery.

11. Apparatus for producing a color coded display of imagery comprising:

means for generating a multiple wavelength high-intensity collimated lighT beam to illuminate said imagery and transmit the data therein to a display surface;

modulating means for independently modulating the intensity of each spectral component of said multiple wavelength light beam in accordance with input signals for each of said components;

scanning means for sweeping said modulated light beam across said imagery;

light responsive means sensitive to at least a portion of the light intensity transmitted through said imagery for generating a signal proportional to the intensity of said modulated scanned light beam; and

a feedback network responsive to the generated signal of said light responsive means for separating said signal into a plurality of control signals individually connected to said modulating means to vary the intensity of one spectral component.

12. Apparatus for producing a color coded display as set forth in claim 11 further including a beam splitter positioned after said modulator and scanner for directing said portion of said modulated scanned light beam to said light responsive means.

13. Apparatus for producing a color coded display as set forth in claim 11 wherein said imagery is an infrared recording and said feedback network separates the signal from said light responsive means into modulator control signals in accordance with the degree of infrared emission recorded on said imagery.

14. Apparatus for producing a color coded display set forth in claim 13 including a condensing lens in optical relationship with the modulated scanned light beam transmitted through said imagery to form the Fourier transform of the recorded data;

a spatial frequency filter for filtering the data recorded on said imagery; and

a projection lens for focusing the filtered modulated scanned light beam on said display surface.

15. Apparatus for producing a color coded display of imagery comprising:

means for generating a multiple wavelength high-intensity collimated light beam to illuminate said imagery and transmit the data therein to a display surface;

means for spectrally separating said multi wavelength light beam into its spectral components;

a plurality of light modulators individually positioned in one component beam for varying the intensity of that spectral component;

means for recombining said modulated spectral components into a single multi wavelength modulated light beam;

scanning means for sweeping said modulated light beam in a pattern across said imagery;

light responsive means for generating a signal proportional to the modulated intensity of said recombined light beams; and

a feedback network responsive to the generated signal of said light responsive means for separating said signal into a plurality of control signals individually connected to one of said light modulators.

16. Apparatus for producing a color coded display of imagery comprising:

a plurality of light generating means each producing a high-intensity collimated light beam at a different wavelength to illuminate said imagery and transmit the data therein to a display surface;

a plurality of light modulators individually positioned in one of said light beams for varying the intensity thereof;

means for combining said plurality of collimated light beam into a single modulated collimated light beam;

scanning means for sweeping said light beam in a pattern across said imagery;

a beam splitter positioned so as to reflect at least a portion of said light beam to said light responsive means;

light responsive means sensitive to said portion for generating a signal proportional to the modulated intensity of said combined collimated light beam; and

amplifying means responsive to the signal generated by said light responsive means and generating a plurality of output signals to control said light modulators.

17. Apparatus for reproducing imagery for display comprising:

a laser generating a high-intensity collimated light beam to illuminate said imagery and transmit the data therein to a display surface;

a light modulator for varying the intensity of the laser light beam in accordance with an input signal;

scanning means for moving said light beam in a pattern across said imagery;

a beam splitter for reflecting a portion of said light beam to be transmitted through said imagery;

light responsive means for generating a signal proportional to the light transmitted through said imagery; and

feedback means responsive to the signal generated by said light responsive means and having an output signal connected to said light modulator.

18. Apparatus for reproducing imagery as set forth in claim 17 including a condensing lens for focusing the light transmitted through said imagery on said light responsive means.

19. Apparatus for reproducing color imagery on a color coded display comprising:

means for generating a multiple wavelength high-intensity collimated light beam to illuminate said imagery and transmit the data therein to a display surface;

a beam splitter positioned so as to reflect a portion of said light beam to be transmitted through said imagery;

scanning means for sweeping the reflected portion of said light beam in a pattern across the area of said imagery;

means for spectrally separating the light beam transmitted through said imagery into its spectral components;

a plurality of light responsive means individually positioned in one component beam for generating a control signal proportional to the intensity of a single spectral component;

means for spectrally separating the unreflected portion of said multiple wavelength light beam transmitted through said beam splitter into its spectral components;

a plurality of light modulators individually positioned in one component beam of said unreflected light beam for varying the intensity of that spectral component in accordance with a respective control signal from one of said light responsive means;

means for recombining said modulated spectral components into a single multiple wavelength modulated light beam; and

second scanning means for sweeping said modulated light beam in a pattern across the display surface.

20. Apparatus for reproducing color imagery as set forth in claim 19 including synchronizing means generating scanning signals to said first and second scanning means to synchronize the operation thereof.

21. Apparatus for reproducing color imagery as set forth in claim 20 indicating a chromatic balance positioned in said multiple wavelength light beam between said means for generating and said beam splitter.

22. Apparatus for reproducing color imagery as set forth in claim 21 wherein said light beam-generating means is a laser-producing multiple spectral components.

23. A method of producing a display of imagery comprising:

generating a high-intensity laser collimated light beam for illuminating said imagery and optically projecting the data therein to a display surface;

modulating said high-intensity collimated light beam in accordance with a feedback signal;

scanning said modulated light beam in a pattern across said imagery; and

generating a feedback signal proportional to the intensity of the modulated light beam transmitted through said imagery.

24. A method of producing a display of imagery as set forth in claim 23 including reflecting a portion of the modulated light beam transmitted through said imagery for generating said feedback signal.

25. A method of producing a display of imagery comprising:

generating a high-intensity collimated light beam for illuminating said imagery and transmitting the data therein to a display surface;

modulating said high-intensity collimated light beam in accordance with a feedback signal;

scanning said modulated light beam in a pattern across said imagery;

reflecting a portion of the modulated light beam transmitted through said imagery for generating a feedback signal proportional to the inteNsity of the modulated light beam transmitted through said imagery; and

generating the Fourier transform of the data recorded on said imagery.

26. A method of producing a display of imagery as set forth in claim 25 including filtering the modulated light beam transmitted through said imagery to remove unwanted data.