Dual-stage high-contrast electronic image display

• US 7,002,533 B2
• Filed: 08/13/2002
• Issued: 02/21/2006
• Est. Priority Date: 08/17/2001
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Michel Sayag
• Inventors: Sayag, Michel
• Primary Examiner(s): Lamarre, Guy
• Assistant Examiner(s): Alphonse, Fritz
• Application Number:
  US10/218,199
• Publication Number:
  US 20030048393A1
• Time in Patent Office: 1,288 Days
• Field of Search: 345/638, 345/636, 345/634, 345/632, 345/629, 345/86, 345/7, 345/1.1, 359/619, 353/38, 349/11
• US Class Current: 345/7
• CPC Class Codes: G09G 2300/023 Display panel composed of stacked panels
• CPC Class Codes: G09G 2320/0209 Crosstalk reduction, i.e. to reduce direct or indirect influences of signals directed to a certain pixel of the displayed image on other pixels of said image, inclusive of influences affecting pixels in different frames or fields or sub-images which constitute a same image, e.g. left and right images of a stereoscopic display
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 5/7441 the modulator being an array of liquid crystal cells
• CPC Class Codes: H04N 5/7458 the modulator being an array of deformable mirrors, e.g. digital micromirror device [DMD]
• CPC Class Codes: H04N 9/3126 for spatial light modulators in series

Abstract

Electronic displays are provided which can reproduce image data with high contrast ratios and a gray scale range comparable to conventional X-ray film viewed on a light box. One such display includes a rear low-resolution LCD or DLP display which projects an image onto a high-resolution LCD display. In such embodiments, the mechanical and optical registration between the two displays is not critical. Therefore, modulation transfer function and distortion of the projection optics are not critical. Accordingly, the brightness of the inventive display can be maximized with high power lamps and high aperture projection optics. Because the display has a high dynamic range, the need for dynamic range compression algorithms is reduced.

Claims

1. A display apparatus, comprising:

a first display disposed in a first plane, having a first area and configured to generate a first image based upon first image data;

a second display disposed in a second plane, having a second area and configured to generate a second image based upon second image data, the first image data comprising lower spatial frequency content than the second image data; and

a projection device for projecting the first image substantially into the second plane, thereby superimposing a projected image and the second image.

2. The display apparatus of claim 1, wherein the first display comprises a transmissive display panel.

3. The display apparatus of claim 2, wherein the first display comprises a transmissive liquid crystal display panel.

4. The display apparatus of claim 1, wherein the first display comprises a reflective display panel.

5. The display apparatus of claim 3, wherein the reflective display panel comprises a digital light processing device.

6. The display apparatus of claim 1, wherein the projection device comprises an optical low-pass filter.

7. The display apparatus of claim 1, wherein the second display comprises a transmissive liquid crystal display panel.

8. The display apparatus of claim 1, wherein the first area is smaller than the second area.

9. The display apparatus of claim 1, further comprising a filter for removing high spatial frequency components from the first image data.

10. The display apparatus of claim 1, further comprising a diffuser disposed in a third plane proximate the second display.

11. The display apparatus of claim 10, wherein the projection device causes the projected image to focus in the third plane.

12. A display method, comprising the steps of:

generating a first image on a first display based upon first image data;

generating a second image on a second display based upon second image data, the first image data comprising lower spatial frequency content than the second image data; and

projecting the first image substantially into the second plane, thereby superimposing a projected image and the second image.

13. The display method of claim 12, further comprising the step of filtering high spatial frequency data from the first image data.

14. The display method of claim 12, further comprising the step of filtering high spatial frequency data from the first image.

15. The display method of claim 12, further comprising the step of filtering high spatial frequency data from the projected image.

16. A display apparatus, comprising:

a filter for filtering high spatial frequency data and low spatial frequency data from image data;

a first liquid crystal display panel disposed in a first plane, having a first area and configured to generate a first image based upon low spatial frequency data received from the filter;

a second liquid crystal display panel disposed in a second plane parallel to the first plane, having a second area larger than the first area and configured to generate a second image based upon high spatial frequency data received from the filter;

a light source for illuminating a first side of the first liquid crystal display panel; and

a projection device disposed proximate a second side of the first liquid crystal display panel for projecting the first image and focusing the first image on the second plane.

17. The display apparatus of claim 16, wherein the projection device comprises a metal halide lamp.

18. The display apparatus of claim 16, wherein an aperture setting of the projection device is greater than f/4 when the projection device projects the first image.

19. The display apparatus of claim 16, wherein the first liquid crystal display panel is configured to receive an eight-bit signal.

20. The display apparatus of claim 16, wherein the second liquid crystal display panel is configured to receive an eight-bit signal.

21. The display apparatus of claim 16, further comprising a diffusing layer disposed upon the second liquid crystal display panel.

22. A display apparatus, comprising:

a filter for filtering high spatial frequency data and low spatial frequency data from image data;

a reflective digital light processing device having a first area and configured to generate a first image based upon low spatial frequency data received from the filter;

a light source for illuminating a first side of the reflective digital light processing device;

a transmissive liquid crystal display panel having a second area larger than the first area and configured to generate a second image based upon high spatial frequency data received from the filter; and

a projection device for projecting a first image from the reflective digital light processing device and for focusing the first image into a plane within which to transmissive liquid crystal display panel is disposed.

23. The display apparatus of claim 22, wherein the projection device comprises a metal halide lamp.

24. The display apparatus of claim 22, wherein an aperture setting of the projection device is greater than f/4 when the projection device projects the first image.

25. The display apparatus of claim 22, wherein the reflective digital light processing device is configured to receive an eight-bit signal.

26. The display apparatus of claim 22, wherein the transmissive liquid crystal display panel is configured to receive an eight-bit signal.

27. The display apparatus of claim 22, further comprising a diffusing layer disposed upon the transmissive liquid crystal display panel.

28. The display apparatus of claim 22, wherein the reflective digital light processing device comprises a digital micromirror device.

29. The display apparatus of claim 28, wherein the digital micromirror device comprises a plurality of pixels and each pixel comprises three separately addressable sub-pixels.

30. A display method, comprising the steps of:

filtering high spatial frequency data and low spatial frequency data from image data;

displaying a first image based upon the low spatial frequency data;

displaying a second image on a liquid crystal display based upon the high spatial frequency data; and

projecting the first image onto the liquid crystal display such that pixel data from the first image are registered with corresponding pixel data from the second image.