Liquid coupled color-television image projector

• US 4,151,554 A
• Filed: 12/07/1977
• Issued: 04/24/1979
• Est. Priority Date: 12/07/1977
• Status: Expired due to Term

• Current Assignee: Electronic Systems Products, Inc. (Ligado Networks, LLC)
• Original Assignee: Arthur R. Tucker
• Inventors: Tucker, Arthur R.
• Primary Examiner(s): Griffin, Robert L.
• Assistant Examiner(s): Orsino, Jr., Joseph A.
• Application Number:
  US05/858,358
• Time in Patent Office: 503 Days
• Field of Search: 358/60, 358/64, 358/55, 358/250, 358/237, 358/238, 358/239, 350/174, 353/54
• US Class Current: 348/749
• CPC Class Codes: H04N 9/31 Projection devices for colour picture display , e.g. using electronic spatial light modulators [ESLM]

Abstract

A color television image projector in which three television projection cathode ray tubes, one for each television primary color, are arranged in a T-shaped array with the face plates of the cathode ray tubes placed in a chamber, and crossed dichroic mirrors are located in the chamber for presenting a single image, composed of the primary color images in superimposed registration, at a window in the chamber. The chamber is filled with a liquid having an index of refraction approximately the same as that of the face plates, the mirror substrates, and the window, and cooling means is associated with the chamber for removing heat from the liquid in the chamber. A projection lens system is associated with the window for projecting the single image presented at the window.

Claims

1. A color-television image projector comprising:

a housing including a wall and an enclosed chamber;

television projection cathode ray tubes having image-producing face plates placed in the housing wall so as to communicate with the chamber, each cathode ray tube being capable of producing a single-color image for projection;

a transparent window in the housing wall;

color-selective mirror means located within the chamber for directing the single-color image from at least one of the cathode ray tubes to the window such that the images of the cathode ray tubes will be in superimposed registration with one another;

a transparent liquid filling the chamber and contacting the face plates, the mirror means, the window, and the housing wall, the transparent liquid having a relatively high index of refraction for bringing the focal plane of the superimposed images in close proximity with the window; and

a projection lens system associated with the window for projecting the superimposed images appearing at the window.

2. The invention of claim 1 including cooling means associated with the housing wall for removing heat from the chamber, through the liquid.

3. The invention of claim 2 wherein the cooling means includes a heat sink associated with the housing wall and communicating with the exterior of the chamber, and means for passing a cooling fluid over the heat sink externally of the chamber.

4. The invention of claim 1 wherein:

the housing is substantially parallelepipedal, having six wall portions;

the cathode ray tubes are placed such that first and second cathode ray tubes are located respectively in opposite first and second wall portions and a third cathode ray tube is located in a third wall portion adjacent to the first and second wall portions; and

the window is located in a fourth wall portion opposite to the third wall portion.

5. The invention of claim 4 including a heat sink associated with at least one of the fifth and sixth wall portions for removing heat from the chamber, through the liquid.

6. The invention of claim 5 wherein the heat sink communicates with the exterior of the chamber and the cooling means includes means for passing a cooling fluid over the heat sink externally of the chamber.

7. The invention of claim 1 wherein:

the mirror means includes a reflective layer carried by a transparent member; and

the liquid has an index of refraction approximately the same as the index of refraction of the transparent member.

8. The invention of claim 7 wherein the transparent member includes transparent plates and the reflective layer is sealed between the plates to preclude direct contact between the liquid and the layer.

9. The invention of claim 7 wherein the index of refraction of the liquid is approximately the same as the index of refraction of the face plates of the cathode ray tubes and the window.

10. The invention of claim 7 wherein:

the number of cathode ray tubes is three, one for each color-television primary color, the cathode ray tubes being placed on axes located in a single plane and perpendicular to one another;

the color-selective mirror means includes two crossed dichroic mirrors, each mirror being placed at an acute angle to the axis of a corresponding cathode ray tube for reflecting only the primary color image projected by the cathode ray tube associated with that mirror; and

the window is placed perpendicular to one of the axes.

11. The invention of claim 10 wherein the acute angle is about 45°

.

12. The invention of claim 10 wherein the transparent member includes transparent plates and the reflective layer is sealed between the plates to preclude direct contact between the liquid and the layer.

13. The invention of claim 12 wherein the window includes a curved surface to serve as an additional optical element in conjunction with the projection lens system.

14. The invention of claim 12 including means for selectively adjusting the position of at least one of the cathode ray tubes relative to the others to assure accurate registration of the superimposed primary color images.

15. The invention of claim 12 including cooling means associated with the housing wall for removing heat from the chamber, through the liquid.

16. The invention of claim 15 wherein the cooling means includes a heat sink associated with the housing wall and communicating with the exterior of the chamber, and means for passing a cooling fluid over the heat sink externally of the chamber.

17. The invention of claim 12 wherein:

the housing is substantially parallelepipedal, having six wall portions;

the cathode ray tubes are placed such that first and second cathode ray tubes are in corresponding opposite first and second wall portions and a third cathode ray tube is in a third wall portion adjacent to the first and second wall portions; and

the window is in a fourth wall portion opposite to the third wall portion.

18. The invention of claim 17 including a heat sink associated with at least one of the fifth and sixth wall portions for removing heat from the chamber, through the liquid.

19. The invention of claim 18 wherein the heat sink communicates with the exterior of the chamber and the cooling means includes means for passing a cooling fluid over the heat sink externally of the chamber.

20. In an image projector in which images from a plurality of image-producing devices are superimposed into a single projected image, the improvement comprising:

a housing including a wall and an enclosed chamber;

the image-producing devices being associated with the housing wall so as to communicate with the chamber;

a transparent window in the housing wall;

color-selective mirror means located within the chamber for directing the image from at least one of the image-producing devices to the window such that the images of the image-producing devices will be in superimposed registration with one another;

a transparent liquid filling the chamber and contacting the image-producing devices, the mirror means, the window, and the housing wall, the transparent liquid having a relatively high index of refraction for bringing the focal plane of the superimposed images in close proximity with the window; and

a projection lens system associated with the window for projecting the superimposed images appearing at the window.

21. The invention of claim 20 including cooling means associated with the housing wall for removing heat from the chamber, through the liquid.

22. The invention of claim 21 wherein the cooling means includes a heat sink associated with the housing wall and communicating with the exterior of the chamber, and means for passing a cooling fluid over the heat sink externally of the chamber.

23. The invention of claim 20 wherein:

the housing is substantially parallelepipedal, having six wall portions;

the image-producing devices are placed such that first and second image-producing devices are in corresponding opposite first and second wall portions and a third image-producing device is in a third wall portion adjacent to the first and second wall portions; and

the window is in a fourth wall portion opposite to the third wall portion.

24. The invention of claim 23 including a heat sink associated with at least one of the fifth and sixth wall portions for removing heat from the chamber, through the liquid.

25. The invention of claim 24 wherein the heat sink communicates with the exterior of the chamber and the cooling means includes means for passing a cooling fluid over the heat sink externally of the chamber.

26. The invention of claim 20 wherein:

the mirror means includes a reflective layer carried by a transparent member; and

the liquid has an index of refraction approximately the same as the index of refraction of the transparent member.

27. The invention of claim 26 wherein the transparent member includes transparent plates and the reflective layer is sealed between the plates to preclude direct contact between the liquid and the layer.

28. The invention of claim 27 including cooling means associated with the housing wall for removing heat from the chamber, through the liquid.

29. The invention of claim 28 wherein the cooling means includes a heat sink associated with the housing wall and communicating with the exterior of the chamber, and means for passing a cooling fluid over the heat sink externally of the chamber.

30. The invention of claim 26 wherein:

the housing is substantially parallelepipedal, having six wall portions;

the image-producing devices are placed such that first and second image-producing devices are in corresponding opposite first and second wall portions and a third image-producing device in a third wall portion adjacent to the first and second wall portions; and

the window is in a fourth wall portion opposite to the third wall portion.

31. The invention of claim 30 including a heat sink associated with at least one of the fifth and sixth wall portions for removing heat from the chamber, through the liquid.

32. The invention of claim 31 wherein the heat sink communicates with the exterior of the chamber and the cooling means includes means for passing a cooling fluid over the heat sink externally of the chamber.