Display panel mount for projection dislay system

• US 5,653,522 A
• Filed: 08/04/1994
• Issued: 08/05/1997
• Est. Priority Date: 08/25/1993
• Status: Expired due to Fees

• Current Assignee: Kopin Corporation
• Original Assignee: Kopin Corporation
• Inventors: Loucks, Bryan E.
• Primary Examiner(s): DOWLING, WILLIAM C
• Application Number:
  US08/285,955
• Time in Patent Office: 1,097 Days
• Field of Search: 353/122, 353/33, 353/34, 353/81, 359/83
• US Class Current: 353/122
• CPC Class Codes: G02B 27/1073 characterized by manufacturing or alignment methods
• CPC Class Codes: G02B 27/144 using partially transparent surfaces without spectral selectivity G02B27/147 takes precedence
• CPC Class Codes: G02B 27/145 having sequential partially reflecting surfaces
• CPC Class Codes: G02B 27/149 using crossed beamsplitting surfaces, e.g. cross-dichroic cubes or X-cubes
• CPC Class Codes: G02F 1/133308 Support structures for LCD panels, e.g. frames or bezels
• CPC Class Codes: G02F 2201/46 Fixing elements
• CPC Class Codes: H04N 9/3105 for displaying all colours simultaneously, e.g. by using two or more electronic spatial light modulators simultaneous projection in colour photography G03B33/10; beam splitting or combining systems per se G02B27/10
• CPC Class Codes: H04N 9/317 Convergence or focusing systems electronic adjustment of convergence H04N9/3185; convergence or focusing arrangements for cathode ray tubes H04N9/28; means for automatic focusing of projectors not peculiar to the presence of an electronic spatial light modulator G03B21/53

Abstract

Liquid crystal display panels are mounted to a beam combining prism such that each display panel can flex in the place of the display panel as a result of thermal stresses. A three-point clip mount for each display panel is bonded between the prism and the display panels.

Claims

1. A display system comprising:

a plurality of N display panels for generating respective images;

an N-to-1 beam combiner having a plurality of unitary reflective surfaces and an optical axis for optically combining the N generated images to form a synthesized image; and

a plurality of three-point mounts, each display panel fixed in an image plane relative to the optical axis of the beam combiner by a respective three-point mount, each three-point mount arranged to permit movement of the respective display panel relative to the beam combiner during operation of the display system.

2. The display system of claim 1 wherein N equals three, a first display panel generating a red-color image, a second display panel generating a green-color image, and a third display panel generating a blue-color image.

3. The display system of claim 1 wherein the display panels are active matrix liquid crystal display panels.

4. The display system of claim 1 wherein the beam combiner is a Philips-type prism.

5. The display system of claim 1 wherein the three-point mounts permit thermal expansion of the display panels in a respective image plane.

6. The display system of claim 5 wherein, for each display panel, a first mount point is rigid in three orthogonal directions relative to the image plane, a second mount point is flexible in a first direction along the respective image plane and rigid in all other directions, and a third mount point is flexible in a second direction along the respective image plane and rigid in all other directions.

7. The display system of claim 6 wherein the first mount point is adjacent to both the second and the third mount points.

8. The display system of claim 1 wherein the three-point mounts are fixed to the beam combiner.

9. The display system of claim 1 wherein the three-point mounts are fixed to a supporting frame of the display system.

10. The display system of claim 1 wherein the beam combiner comprises at least two optical elements, each optical element interacting with an adjacent optical element at a unitary reflective surface.

11. A liquid crystal projection display system comprising:

a plurality of liquid crystal display panels for generating respective images;

a light source to direct light through each display panel;

a beam combiner having a plurality of unitary reflective surfaces and an optical axis for optically combining the generated images to form a synthesized image;

a plurality of mounts, each display panel fixed in an image plane relative to the optical axis of the beam combiner by a respective mount that permits thermal expansion of the display panel in the respective image plane; and

an optical system for projecting the synthesized image onto a display surface.

12. The projection display system of claim 11 wherein there are three display panels, a first display panel generating a red-color image, a second display panel generating a green-color image, and a third display panel generating a blue-color image.

13. The projection display system of claim 11 wherein the display panels are active matrix liquid crystal display panels.

14. The projection display system of claim 11 wherein the beam combiner is a Philips-type prism.

15. The projection display system of claim 11 wherein the mounts are three-point mounts.

16. The projection display system of claim 15 wherein, for each display panel, a first mount point is rigid in three orthogonal directions relative to the image plane, a second mount point is flexible in a first direction along the respective image plane and rigid in all other directions, and a third mount point is flexible in a second direction along the respective image plane and rigid in all other directions.

17. The projection display system of claim 11 wherein a cavity between each display panel and the beam combiner is selected such that the displacement between the display panel and a position at optimal focus is less than 0.5 mm.

18. The projection display system of claim 15 wherein the three-point mounts are fixed to the beam combiner.

19. The projection display system of claim 15 wherein the three-point mounts are fixed to a supporting frame of the projection display system.

20. The display system of claim 11 wherein the beam combiner comprises at least two optical elements, each optical element interacting with an adjacent optical element at a unitary reflective surface.

21. A display panel registration apparatus comprising:

a plurality of display panels for generating respective images;

an optical combiner having an optical axis for optically combining the generated image to form a synthesized image; and

a plurality of flexible mounts, each mount fixing a respective display panel in an image plane relative to the optical axis of the optical combiner so the generated images are registered to form the synthesized image, each mount arranged to permit movement of the respective display panel relative to the optical combiner during operation of the display panels.

22. A method of fixing a plurality of display panels which generate respective images relative to an optical combiner having an optical axis which forms a synthesized image from the generated images, comprising the steps of:

providing a plurality of flexible mounts;

aligning each display panel in a respective image plane relative to the optical axis of the optical combiner so the generated images are registered to form the synthesized image; and

fixing the aligned display panels in the respective image planes using respective flexible mounts so that each mount permits movement of the respective display panel relative to the optical combiner during operation of the display panels.