Crosstalk suppression in time sequential liquid crystal stereoscopic display systems

• US 20110164194A1
• Filed: 01/05/2011
• Published: 07/07/2011
• Est. Priority Date: 01/05/2010
• Status: Active Grant

• Current Assignee: RealD Incorporated
• Original Assignee: RealD Incorporated
• Inventors: McKnight, Douglas J., Robinson, Michael G.
• Granted Patent: US 8,766,890 B2
• Time in Patent Office: Days
• US Class Current: 349/15
• CPC Class Codes: G02B 30/24 involving temporal multiplexing, e.g. using sequentially activated left and right shutters
• CPC Class Codes: G02B 30/25 using polarisation techniques
• CPC Class Codes: G09G 2310/062 Waveforms for resetting a plurality of scan lines at a time
• CPC Class Codes: G09G 3/003 to produce spatial visual effects
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336
• CPC Class Codes: G09G 3/3611 Control of matrices with row and column drivers
• CPC Class Codes: H04N 13/341 using temporal multiplexing

Abstract

This disclosure primarily concerns 3D stereoscopic displays that provide alternately polarized left and right eye images encoded with a modulating LC polarization control panel (PCP) attached to the front of the display. Viewers then wear polarization analyzing eyewear to correctly see the different images. More specifically, the disclosure introduces global LC electrical reset during the addressing of liquid crystal time-sequential stereoscopic displays in order to reduce left/right eye contamination. LC materials in general do not respond fast enough with conventional addressing schemes to provide independent left and right eye images at the desired flicker-free, rate of sixty frames per second per eye. This disclosure and its embodiments may overcome this limitation, and also may address motion blur limitations, by driving pixels to a common LC state as part of the addressing cycle.

Claims

1. A method for crosstalk suppression in a time sequential liquid crystal stereoscopic display system, comprising:

after displaying a first eye image, stopping light to a viewer for a dark period;

during the dark period;

writing data sequentially on a liquid crystal (LC) panel, and

applying a reset pulse to an electrode on the LC panel after the last line is written; and

allowing light to the viewer after the reset pulse is applied, for a viewing period.

2. The method of claim 1, wherein writing data sequentially comprises writing data sequentially from top to bottom lines of the LC panel.

3. The method of claim 1, wherein writing data comprises applying voltages to bottom electrodes corresponding to pixels of the LC panel, and wherein applying the reset pulse comprises applying the reset pulse to a top electrode on the LC panel.

4. The method of claim 1, further comprising, during the dark period, globally resetting substantially all pixels in the LC panel to a common LC state.

5. The method of claim 4, wherein the common LC state comprises a common dark state.

6. The method of claim 1, further comprising displaying a second eye image.

7. The method of claim 1, further comprising returning the top electrode to a common voltage level.

8. The method of claim 1, further comprising, during the dark period, switching a polarization converting panel between a first-eye and a second-eye polarization mode.

9. A method for crosstalk suppression in a time sequential liquid crystal stereoscopic display system, comprising:

after displaying a first eye image, turning off a backlight for a dark period;

during the dark period;

writing data sequentially on a liquid crystal (LC) panel, and

applying a reset pulse to an electrode on the LC panel just after the last line is written; and

turning on the backlight just after the reset pulse is applied, for a viewing period.

10. The method of claim 9, wherein writing data sequentially comprises writing data sequentially from top to bottom lines of the LC panel, and wherein writing data further comprises applying voltages to bottom electrodes corresponding to pixels of the LC panel, and wherein applying the reset pulse comprises applying the reset pulse to a top electrode on the LC panel.

11. The method of claim 9, further comprising, during the dark period, globally resetting substantially all pixels in the LC panel to a common LC state.

12. The method of claim 11, wherein the common LC state comprises a common dark state.

13. The method of claim 9, further comprising displaying a second eye image.

14. The method of claim 9, further comprising returning the top electrode to a common voltage level.

15. The method of claim 9, further comprising, during the dark period, switching a polarization converting panel between a first-eye and a second-eye polarization mode.

16. A method for crosstalk suppression in a time sequential liquid crystal stereoscopic display system, comprising:

after displaying a first eye image, blocking light by synchronizing the display system with shutter glasses blocking light from reaching a viewer for a dark period;

during the dark period;

writing data sequentially on a liquid crystal (LC) panel, and

applying a reset pulse to an electrode on the LC panel just after the last line is written; and

allowing light by synchronizing the display system with the shutter glasses allowing light to reach the viewer just after the reset pulse is applied, for a viewing period.

17. The method of claim 16, wherein writing data sequentially comprises writing data sequentially from top to bottom lines of the LC panel, and wherein writing data further comprises applying voltages to bottom electrodes corresponding to pixels associated with the lines of the LC panel, and wherein applying the reset pulse comprises applying the reset pulse to a top electrode on the LC panel.

18. The method of claim 16, further comprising, during the dark period, globally resetting substantially all pixels in the LC panel to a common LC state.

19. The method of claim 18, wherein the common LC state comprises a common dark state.

20. The method of claim 16, further comprising returning the top electrode to a common voltage level to display a second eye image.