Content-adaptive parallax barriers for automultiscopic display

Patent metadata

Field	Value
Publication number	US-9335553-B2
Application number	US-201514836212-A
Country	US
Kind code	B2
Filing date	Aug 26, 2015
Priority date	Dec 1, 2010
Publication date	May 10, 2016
Grant date	May 10, 2016

Abstract

In exemplary implementations of this invention, two LCD screens display a multi-view 3D image that has both horizontal and vertical parallax, and that does not require a viewer to wear any special glasses. Each pixel in the LCDs can take on any value: the pixel can be opaque, transparent, or any shade between. For regions of the image that are adjacent to a step function (e.g., a depth discontinuity) and not adjacent to a sharp corner, the screens display local parallax barriers comprising many small slits. The barriers and the slits tend to be oriented perpendicular to the local angular gradient of the target light field. In some implementations, the display is optimized to seek to minimize the Euclidian distance between the desired light field and the actual light field that is produced. Weighted, non-negative matrix factorization (NMF) is used for this optimization.

First claim

What is claimed is:

1. A method that comprises a pair of spatial light modulators displaying time-multiplexed mask pairs, wherein:
(a) the pair of modulators comprises a rear modulator and a front modulator;
(b) each mask pair comprises a rear mask and a front mask, such that the rear mask is displayed by the rear modulator while the front mask is displayed by the front modulator;
(c) the pair of modulators generate an auotomultiscopic display;
(d) light from a backlight passes first through the rear modulator and then through the front modulator;
(e) the automultiscopic display has a refresh rate of at least 13 Hz; and
(f) during each refresh of the automultiscopic display, the pair of modulators display a set of time-multiplexed mask pairs that produce a pattern of light that would, if integrated by a viewer's eye, comprise an approximation of a target light field, which approximation has a matrix rank higher than one.

2. The method of claim 1 , wherein each of the mask pairs, respectively, produces a light field that is an approximation of the target light field, which approximation has a matrix rank of one.

3. The method of claim 1 , wherein method further comprises optimizing the display to minimize Euclidean distance between the target light field and a light field produced by the pair of modulators.

4. The method of claim 3 , further comprising performing non-negative matrix factorization to minimize the Euclidean distance.

5. The method of claim 4 , wherein the non-negative matrix factorization is weighted.

6. The method of claim 1 , wherein the target light field is a 4D light field.

7. The method of claim 1 , wherein the display has a refresh rate that is between 13 Hz and 120 Hz.

8. The method of claim 1 , wherein the automultiscopic display has that has horizontal motion parallax and vertical motion parallax.

9. The method of claim 1 , wherein the spatial light modulators are LCDs.

10. The method of claim 1 , wherein each pixel, out of a majority of pixels in the front modulator, varies in opacity over a range, which range includes more than two opacity levels.

11. A method that comprises a pair of spatial light modulators displaying time-multiplexed mask pairs, wherein:
(a) the pair of modulators comprises a rear modulator and a front modulator;
(b) each mask pair comprises a rear mask and a front mask, such that the rear mask is displayed by the rear modulator while the front mask is displayed by the front modulator;
(c) the pair of modulators generate a display that has motion parallax;
(d) light from a backlight passes first through the rear modulator and then through the front modulator; and
(e) the pair of modulators display a set of time-multiplexed mask pairs that produce a pattern of light that would, if summed by a viewer's eye, comprise an approximation of a target light field, which approximation has a matrix rank higher than one.

12. The method of claim 11 , wherein each of the mask pairs, respectively, produces a light field that is an approximation of the target light field, which approximation has a matrix rank of one.

13. The method of claim 11 , wherein method further comprises optimizing the display to minimize Euclidean distance between the target light field and a light field produced by the pair of modulators.

14. The method of claim 13 , further comprising performing non-negative matrix factorization to minimize the Euclidean distance.

15. Apparatus comprising a pair of spatial light modulators, which pair of modulators comprises a front modulator and a rear modulator and is configured, when backlit by light that passes through the rear and front modulators, to display time-multiplexed mask pairs, such that:
(a) the pair of modulators generates an automultiscopic display;
(b) each mask pair comprises a rear mask displayed by the rear modulator and a front mask simultaneously displayed by the front modulator; and
(c) a set of multiple mask pairs produces a time-multiplexed light pattern that would, if integrated by a viewer's eye, comprise an approximation of a target light field, which approximation has a matrix rank higher than one.

16. The apparatus of claim 15 , wherein the display is optimized to minimize Euclidean distance between the target light field and a light field produced by the pair of modulators.

17. Apparatus comprising a pair of LCDs, which pair of LCDs comprises a front LCD and a rear LCD and is configured, when backlit by light that passes through the rear and front LCDs, to display time-multiplexed mask pairs, such that:
(a) the pair of LCDs displays an image that changes over time and that has horizontal and vertical parallax;
(b) each mask pair comprises a rear mask displayed by the rear layer and a front mask displayed by the front layer, the front mask being displayed while the rear mask is displayed;
(c) the image has a refresh rate that is between 13 Hz and 120 Hz; and
(d) during each refresh of the image, a set of multiple mask pairs produces a time-multiplexed light pattern that would, if integrated by a viewer's eye, comprise an approximation of a target light field, which approximation has a matrix rank higher than one.

18. The apparatus of claim 17 , wherein the display is optimized to minimize Euclidean distance between the target light field and a light field produced by the pair of modulators.

19. The apparatus of claim 17 , wherein each of the mask pairs, respectively, is configured, when backlit, to produce a light field that is an approximation of the target light field, which approximation has a matrix rank of one.

20. The apparatus of claim 17 , wherein each pixel, out of a majority of pixels in the front LCD, is configured to vary in opacity over a range, which range includes more than two opacity levels.

Assignees

• Lanman Douglas
• Hirsch Matthew
• Kim Yun Hee
• Jakubczak Szymon
• Raskar Ramesh
• Massachusetts Inst Technology

Inventors

• Lanman Douglas
• Hirsch Matthew
• Kim Yun Hee
• Jakubczak Szymon
• Raskar Ramesh

Classifications

• G02B30/24

  involving temporal multiplexing, e.g. using sequentially activated left and right shutters · CPC title

• H04N13/32 Primary

  using arrays of controllable light sources; using moving apertures or moving light sources · CPC title

• H04N13/315

  the parallax barriers being time-variant · CPC title

• H04N13/307

  using fly-eye lenses, e.g. arrangements of circular lenses · CPC title

• G02B27/225

  Physics · mapped topic