High resolution autostereoscopic display apparatus with interlaced image

• US 20080036853A1
• Filed: 04/09/2007
• Published: 02/14/2008
• Est. Priority Date: 05/04/2006
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jung, Sung-yong, Kim, Dae-sik, Shestak, Sergey
• Granted Patent: US 8,284,241 B2
• Time in Patent Office: Days
• US Class Current: 348/51
• CPC Class Codes: H04N 13/305 using lenticular lenses, e.g. arrangements of cylindrical lenses
• CPC Class Codes: H04N 13/32 using arrays of controllable light sources; using moving apertures or moving light sources

Abstract

An autostereoscopic display apparatus includes a backlight unit, a polarizing plate disposed in front of the backlight unit; a display panel displaying a left eye image and a right eye image by interlacing pixel lines of the left and right eye images alternately and sequentially; a lenticular lens sheet, disposed between the polarizing plate and the display panel, separating light emitted from the backlight unit into a left eye zone and a right eye zone; and a polarization switch controlling a polarization direction of light proceeding towards the left eye viewing zone so that light is incident on pixel lines of the display panel displaying the left eye image and a polarization direction of light proceeding towards the right eye viewing zone so that light is incident on pixel lines of the display panel displaying the right eye image, in synchronization with a vertical scanning time of the display panel.

Claims

1. An autostereoscopic display apparatus comprising:

a backlight unit;

a polarizing plate disposed in front of the backlight unit;

a display panel which displays a left eye image and a right eye image by interlacing pixel lines of the left and right eye images alternately and sequentially;

a lenticular lens sheet, disposed between the polarizing plate and the display panel, which separates light emitted from the backlight unit into a left eye viewing zone and a right eye viewing zone; and

a polarization switch which controls a polarization direction of light proceeding towards the left eye viewing zone so that light is incident on pixel lines of the display panel displaying the left eye image and controls a polarization direction of light proceeding towards the right eye viewing zone so that light is incident on pixel lines of the display panel displaying the right eye image, in synchronization with a vertical scanning time of the display panel.

2. The apparatus of claim 1, wherein the polarization switch comprises:

a spatial light modulator disposed between the polarizing plate and the lenticular lens sheet and which switches between first, second, and third statuses in which the polarization direction of incident light changes according to electric control;

a first birefringent element array, disposed between the spatial light modulator and the lenticular lens sheet, comprising a plurality of first and second vertical birefringent elements that alternate in the horizontal direction, and which change the polarization direction of incident light so that the polarization direction of light passing through the first birefringent elements is perpendicular to the polarization direction of light passing through the second birefringent elements; and

a second birefringent element array disposed between the lenticular lens sheet and the display panel, comprising a plurality of third and fourth horizontal birefringent elements that alternate in the vertical direction, and which change the polarization direction of incident light so that the polarization direction of light passing through the third birefringent elements is perpendicular to the polarization direction of light passing through the fourth birefringent elements.

3. The apparatus of claim 2, wherein the third and fourth birefringent elements of the second birefringent element array each correspond to one of the pixel lines of the display panel.

4. The apparatus of claim 2, wherein, the second birefringent element array further comprises an opaque mask having a striped shape disposed between the third and fourth birefringent elements.

5. The apparatus of claim 4, further comprising a black matrix disposed between pixels of the display panel, wherein a width of the black matrix is D2, a width of the opaque mask is D1, a distance between the pixels of the display panel and the second birefringent element array is t, a viewing distance from the display panel is L, and a height H2 of a viewing zone having no cross talk satisfies an equation where

H2=(L/t)(D₁+D₂).

6. The apparatus of claim 2, wherein a pitch in a vertical direction between the third and fourth birefringent elements of the second birefringent element array is greater than a pitch in the vertical direction between pixel lines of the display panel.

7. The apparatus of claim 2, wherein each of the first, second, third, and fourth birefringent elements comprises a polarizer having a predetermined polarization plane such that the polarization plane of the polarizers of the first birefringent elements are perpendicular to the polarization plane of the polarizers of the second birefringent elements, and the polarization plane of the polarizers of the third birefringent elements are perpendicular to the polarization plane of the polarizers of the fourth birefringent elements.

8. The apparatus of claim 2, wherein each of the first, second, third, and fourth birefringent elements comprises a retarder that delays the incident light by a predetermined phase, wherein a phase delay difference between the retarders of the first and second birefringent elements is λ

/2, and a phase delay difference between the retarders of the third and fourth birefringent elements is λ

/2.

9. The apparatus of claim 2, wherein each of the first, second, third, and fourth birefringent elements comprises a rotator that rotates the incident light by a predetermined angle, wherein a rotation angle difference between the rotators of the first and second birefringent elements is 90°

, and a rotation angle difference between the rotators of the third and fourth birefringent elements is 90°

.

10. The apparatus of claim 2, wherein the spatial light modulator switches between the first status in which the polarization direction of the incident light is not changed, the second status in which the polarization state of the incident light is changed to circularly polarized light, and the third status in which the polarization direction of the incident light is changed by 90°

.

11. The apparatus of claim 10, wherein the spatial light modulator is a crystal liquid retarder that is electrically controllable.

12. The apparatus of claim 10, wherein, when the spatial light modulator is in the first status, light passing through the third birefringent elements proceeds towards the first eye viewing zone and light passing through the fourth birefringent elements proceeds towards the second eye viewing zone.

13. The apparatus of claim 12, wherein, when the spatial light modulator is in the third status, light passing through the third birefringent elements proceeds towards the second eye viewing zone and light passing through the fourth birefringent elements proceeds towards the first eye viewing zone.

14. The apparatus of claim 2, wherein the lenticular lens sheet comprises a plurality of vertical lenticular lens elements arranged along the horizontal direction and parallel to the first and second birefringent elements of the first birefringent element array.

15. The apparatus of claim 14, wherein a pitch between the vertical lenticular lens elements of the lenticular lens sheet is note greater than a pitch between pairs of the first and second birefringent elements of the first birefringent element array.

16. The apparatus of claim 14, wherein a distance between the lenticular lens sheet and the first birefringent element array is not less than a focal length of the vertical lenticular lens elements.

17. The apparatus of claim 14, wherein light passing through the first birefringent elements passes through the lenticular lens sheet to proceed towards the first eye viewing zone and light passing through the second birefringent elements passes through the lenticular lens sheet to proceed towards the second eye viewing zone.

18. The apparatus of claim 2, wherein the backlight unit and the spatial light modulator are each divided into a plurality of horizontal segments that are sequentially switched in synchronization with a vertical scanning time of the display panel.

19. The apparatus of claim 18, wherein the backlight unit and the spatial light modulator are divided such that a plurality of horizontal segments that are capable of being independently switched are arranged along the vertical direction, and the number of horizontal segments of the backlight unit is the same as the number of horizontal segments of the spatial light modulator.

20. The apparatus of claim 19, wherein corresponding horizontal segments of the backlight unit and the spatial light modulator are simultaneously switched.

21. The apparatus of claim 18, wherein the horizontal segments of each of the backlight unit and the spatial light modulator correspond to a plurality of pixel lines of the display panel.

22. The apparatus of claim 18, wherein the display panel displays an image for the first eye viewing zone of a first frame in odd pixel lines and an image for the second eye viewing zone of the first frame in even pixel lines and displays an image for the first eye viewing zone of a second frame in the even pixel lines and an image for the second eye viewing zone of the second frame in the odd pixel lines.

23. The apparatus of claim 22, wherein, in each horizontal segment of the spatial light modulator, the first and third statuses of the spatial light modulator are time-sequentially and alternately switched in synchronization with the display panel.

24. The apparatus of claim 1, wherein the polarization switch comprises:

a spatial light modulator, disposed between the polarizing plate and the lens sheet, comprising a plurality of first vertical columns and second vertical columns that change the polarization direction of incident light, are independently controlled and alternately provided; and

a birefringent element array, disposed between the lenticular lens sheet and the display panel, comprising a plurality of first and second horizontal birefringent elements, alternating in the vertical direction, which change the polarization direction of incident light such that a polarization direction of light passing through the first birefringent elements is perpendicular to a polarization direction of light passing through the second birefringent elements.

25. The apparatus of claim 24, wherein the first and second horizontal birefringent elements of the birefringent element array each correspond to one of the pixel lines of the display panel.

26. The apparatus of claim 24, wherein the birefringent element array further comprises an opaque mask having a striped shape disposed between the first and second horizontal birefringent elements.

27. The apparatus of claim 24, wherein a pitch in the vertical direction between the first and second horizontal birefringent elements of the birefringent element array is greater than a pitch in the vertical direction between the pixel lines of the display panel.

28. The apparatus of claim 24, wherein the first and second horizontal birefringent elements each comprise a retarder that delays the phase of the incident light, wherein a phase delay difference of the retarders of the first horizontal birefringent elements and the retarders of the second horizontal birefringent elements is λ

/2.

29. The apparatus of claim 24, wherein the spatial light modulator switches between a first status in which the first vertical columns do not change a polarization direction of incident light and the second vertical columns change a polarization direction of incident light by one of +90°

and −

90°

; and

a second status in which the first vertical columns change a polarization direction of incident light by one of +90° and

−

90° and

the second vertical columns do not change a polarization direction of incident light.

30. The apparatus of claim 24, wherein the lenticular lens sheet comprises a plurality of vertical lenticular lens elements arranged along the horizontal direction and parallel to the vertical columns of the spatial light modulator.

31. The apparatus of claim 30, wherein a pitch between the vertical lenticular lens elements of the lenticular lens sheet is not greater than twice a pitch between the vertical columns of the spatial light modulator.

32. The apparatus of claim 30, wherein a distance between the lenticular lens sheet and the spatial light modulator is not less than a focal length of the vertical lenticular lens element.

33. The apparatus of claim 24, wherein the display panel repeatedly displays an image for the left eye of a first frame in odd pixel lines and an image for the right eye of the first frame in even pixel lines and displays an image for the left eye of a second frame in the even pixel lines and an image for the right eye of the second frame in the odd pixel lines.

34. The apparatus of claim 24, wherein the spatial light modulator comprises a plurality of horizontal segments that are sequentially switched in synchronization with a vertical scanning time of the display panel.

35. The apparatus of claim 34, wherein the spatial light modulator comprises:

a liquid crystal layer;

first and second vertical column electrodes disposed in the vertical direction on a front surface of the liquid crystal layer, facing each other in an interdigit array; and

a common electrode disposed on a rear surface of the liquid crystal layer,

wherein the common electrode comprises a plurality of horizontal segments.

36. An autostereoscopic display apparatus comprising:

a backlight unit;

a lenticular lens sheet which separates light emitted from the backlight unit into a left eye viewing zone and a right eye viewing zone;

a display panel which displays a left eye image and a right eye image by interlacing pixel lines of the left and right eye images alternately and sequentially; and

a spatial light modulator, disposed between the backlight unit and the lenticular lens sheet, comprising a plurality of cells independently switching between a transparent state and an opaque state in synchronization with a vertical scanning time of the display panel,

wherein the cells of the spatial light modulator are arranged in two dimensions along rows and columns.

37. The apparatus of claim 36, wherein the spatial light modulator switches between a first status in which all cells are transparent, a second status in which transparent cells and opaque cells are arranged in a checkered pattern, and a third status in which the transparent cells in the second status are opaque cells and the opaque cells in the second status are transparent cells.

38. The apparatus of claim 37, wherein the display panel repeatedly displays a left eye image of a first frame in odd pixel lines and a right eye image for the first frame in even pixel lines and a left eye image of a second frame in the even pixel lines and a right eye image of the second frame in the odd pixel lines.

39. The apparatus of claim 38, wherein the spatial light modulator switches between the second and third statuses sequentially and line by line in synchronization with a vertical scanning time of the display panel.

40. The apparatus of claim 36, wherein a number of cells in the vertical direction of the spatial light modulator is the same as that of a number of pixel lines of the display panel.

41. The apparatus of claim 36, wherein the lenticular lens sheet comprises a plurality of vertical lenticular lens elements arranged along the horizontal direction and parallel to the spatial light modulator.

42. The apparatus of claim 36, wherein a width of the vertical lenticular lens elements of the lenticular lens sheet is not less than a width of two cells of the spatial light modulator.

43. The apparatus of claim 36, wherein a distance between the lenticular lens sheet and the spatial light modulator is not less than a focal length of the vertical lenticular lens elements.

44. The apparatus of claim 36, further comprising an opaque mask having a striped shape disposed in the horizontal direction between rows of the cells of the spatial light modulator.

45. The apparatus of claim 36, wherein a pitch in the vertical direction between the horizontal opaque mask of the spatial light modulator is greater than a pitch between the pixel lines of the display panel.