APPARATUS TO MATCH THE COLOR OF A MONOCHROME DISPLAY TO AVERAGE COLOR OF AN ADJACENT FULL COLOR DISPLAY

• US 3,699,244 A
• Filed: 08/23/1971
• Issued: 10/17/1972
• Est. Priority Date: 08/23/1971
• Status: Expired due to Term

• Current Assignee: Link Flight Simulation Corporation Kirkwood Industrial Park Binghamton NY 13902-1237
• Original Assignee: Edwin Cohen, John C. Altmiller
• Inventors: Cohen, Edwin, Altmiller, John C.
• Primary Examiner(s): Richardson, Robert L.
• Application Number:
  US05/173,843
• Time in Patent Office: 421 Days
• Field of Search: 178/5.4R,7.3R,7.5R,5.2R,5.4ML,5.4HE,DIG.35,DIG.23,DIG.13,7.3D,7.5D 35/12R,12N
• US Class Current: 348/779
• CPC Class Codes: H04N 9/31 Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]

Abstract

Apparatus, for use in a display system wherein a central high resolution color image is supplemented by crude monochrome display, which senses the average color in the high resolution display and adds that color to the monochrome display is shown. Two embodiments for use with projected images are described. One in which the sensed color is provided by passing the light through a C.I.E. diagram positioned by the sensed color signals to obtain a matching color and a second in which controlled amounts of light are mixed to obtain the color. An embodiment for use with a CRT displays in which the three color video signals are averaged of a line on the high resolution display and the average provided to the monochrome displays is also shown.

Claims

1. In a visual display system having a central high resolution color display and one or more monochromatic displays adjacent thereto, apparatus to add color to the monochromatic displays which will approximate the average color of the high resolution color display, or a portion thereof, comprising:

a. means to sense the average color of at least a portion of the high resolution display; and

b. means to provide said sensed average color to the monochromatic displays.

2. The invention according to claim 1 wherein said sensing means sense the three primary colors in said display and provide outputs corresponding thereto.

3. The invention according to claim 2 wherein said displays are obtAined by projecting images on a screen.

4. The invention according to claim 3 wherein said means to provide said sensed color comprise a color filter containing all possible color combinations on different sections thereof interposed in the projection path of said monochromatic displays, the color of said filter being a function of its position, and means to position said filter in response to said sensing means.

5. The invention according to claim 4 wherein said color filter is in the form of a C.I.E. diagram and said positioning means is a servo driven X - Y table whereby said diagram will provide the proper color when x of the table equals X/(X+Y+Z) and y of the table equals Y/(X+Y+Z) where X is the amount or red, Y the amount of green and Z the amount of blue sensed by said sensing means.

6. The invention according to claim 5 and further including a neutral density filter, having a density which varies as a function of position, interposed in said projection path, and means to control the position of said filter in accordance with the total of all light sensed by said sensing means.

7. The invention according to claim 6 wherein said filter is in the form of a disk with its density varying as a function of angle and said position control means comprise a position servo adapted to rotate said disk.

8. The invention according to claim 3 wherein said means to provide said sensed color comprise:

a. red, green and blue light sources;

b. variable neutral density filters interposed in the paths of said light sources;

c. means to control the density of said filters as a function of the color sensed by said sensing means; and

d. means to combine the light from said sources for projection on said monochromatic display.

9. The invention according to claim 8 wherein said filters are disks having a density which is a function of angle, said control means are position servos controlling the angular position of said disks and said combining means comprise beam splitters.

10. The invention according to claim 3 wherein said sensing means comprise:

a. a first beamsplitter placed in the projection path of said high resolution display arranged to direct a portion of the light in a first deflected path essentially perpendicular to the axis of said projection path;

b. a red dichroic mirror placed in said first deflected path and arranged to deflect red light in a second deflected path;

c. a green dichroic mirror placed in said first deflected path and arranged to deflect green light in a third deflected path;

d. a blue dichroic mirror placed in said first deflected path and arranged to deflect blue light in a fourth deflected path; and

e. first, second and third photo-multipliers arranged to intersect respectively said second, third and fourth deflected paths whereby the outputs of said photomultipliers will respectively indicate the amounts of red, green and blue light.

11. The invention according to claim 10 and further including a second beam splitter interposed in said first deflected path between said first beamsplitter and said dichroic mirrors to deflect a portion of the total light along a fifth deflected path and a fourth photomultiplier arranged to intersect said fifth deflected path to develop an output corresponding to said total light.

12. The invention according to claim 11 and further including first, second, third and fourth lenses interposed in said second, third, fourth and fifth deflected paths to image the light in said paths on said first, second, third and fourth photomultipliers.

13. The invention according to claim 2 wherein said displays are color television displays, said high resolution display having a color input and said monochromatic displays having a monochromatic input, and said sensing means comprise means to detect the red, green, and blue video signals of said high resolution color display and said means To provide said sensed color comprise first, second and third averaging means having said red, green and blue video signals as an input and providing color outputs to said monochromatic displays which are the average of each of the respective inputs.

14. The invention according to claim 13 wherein said output is the average color for a single horizontal line on said high resolution display.

15. The invention according to claim 14 wherein each of said averaging means comprise:

a. an integrator having a respective one of said video signals as an input;

b. a sample and hold circuit connected to the output of said integrator and having an output to be provided to said monochromatic displays; and

c. means to reset said integrator once during each horizontal line and to cause said sample and hold circuit to hold the integrated value present at the time of each reset.

16. The invention according to claim 15 wherein said reset is activated by horizontal blanking, whereby a whole line will be integrated.

17. The invention according to claim 15 wherein said reset is activated by a signal set to occur a predetermined time after start each of horizontal scan, whereby only a portion of each line will be integrated.