WEDGE BACKLIGHT WITH DIFFRACTION GRATING

• US 20110216266A1
• Filed: 05/14/2010
• Published: 09/08/2011
• Est. Priority Date: 03/02/2010
• Status: Abandoned Application

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Travis, Adrian
• Application Number:
  US12/780,671
• Publication Number:
  US 20110216266A1
• Time in Patent Office: Days
• US Class Current: 349/62
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02F 1/1335 Structural association of cells with optical devices, e.g. polarisers or reflectors
• CPC Class Codes: G02F 1/133504 Diffusing, scattering, diffracting elements associated to illuminating devices G02F1/133606
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133621 providing coloured light G02F1/133617, G02F1/133533 take precedence

Abstract

Embodiments are disclosed herein that relate to backlighting a display panel comprising color filters via an optical wedge. For example, one disclosed embodiment provides a display panel comprising a plurality of pixels, and also comprising an optical wedge disposed optically upstream of the display panel such that light emerging from the light output interface backlights the display panel. The display system further comprises one or more light sources configured to introduce light into the optical wedge, and a diffraction grating disposed optically between the light sources and the display panel.

Claims

1. A display panel system, comprising:

a display panel comprising a plurality of pixels;

an optical wedge disposed optically upstream of the display panel such that light emerging from the optical wedge backlights the display panel;

one or more light sources configured to introduce light into the optical wedge; and

a diffraction grating disposed optically between the one or more light sources and the display panel.

2. The display panel system of claim 1, wherein the diffraction grating is located optically between the optical wedge and the display panel.

3. The display panel system of claim 2, wherein the optical wedge is configured to emit internally reflected light from the one or more light sources through a major surface that faces the display panel, wherein a turning film is coupled to the optical wedge at the major surface that faces the display panel, and wherein the diffraction grating is formed on the turning film.

4. The display panel system of claim 2, wherein the optical wedge is configured to emit internally reflected light from the light sources through a major surface of the optical wedge that faces away from the display panel, wherein a turning film is coupled to the optical wedge at the major surface that faces away from the display panel, and wherein the diffraction grating is formed on the turning film.

5. The display panel system of claim 2, wherein the diffraction grating serves as a turning film that redirects light emitted from the optical wedge toward the display panel.

6. The display panel system of claim 1, wherein the one or more light sources comprise white light sources.

7. The display panel system of claim 6, wherein the display panel further comprises a plurality of color filters arranged in columns that run parallel to a short dimension of the display panel, and wherein the lines of the diffraction grating run in a direction parallel to the color filters.

8. The display panel system of claim 1, wherein the display panel is a liquid crystal display panel.

9. The display panel system of claim 1, wherein the optical wedge has a direction of taper that is parallel to a long dimension of the display panel.

10. The display panel system of claim 1, wherein the display panel further comprises a plurality of color filters, and wherein the display panel system further comprises a lens array configured to focus colored light from the diffraction grating through the color filters.

11. The display panel system of claim 1, wherein the display panel system is configured to utilize a first order of diffracted light and one or more higher orders of diffracted light for image production.

12. The display panel system of claim 1, wherein the display panel system is configured to utilize only a first order of diffracted light for image production.

13. A liquid crystal display system, comprising:

a liquid crystal display panel comprising a plurality of pixels, each pixel comprising a plurality of color filters;

an optical wedge disposed optically upstream of the liquid crystal display panel such that light emerging from the optical wedge backlights the liquid crystal display panel;

a plurality of white light sources each configured to introduce white light into the optical wedge;

a diffraction grating located optically between the optical wedge and the color filters of the liquid crystal display panel; and

a lens array located optically between the diffraction grating and the color filters of the display panel.

14. The display system of claim 13, wherein the optical wedge is configured to emit internally reflected light from the light sources through a major surface that faces the liquid crystal display panel, wherein a turning film is coupled to the optical wedge at the major surface that faces the liquid crystal display panel, and wherein the diffraction grating is formed on the turning film.

15. The display system of claim 13, wherein the optical wedge is configured to emit internally reflected light from the light sources through a major surface of the optical wedge that faces away from the liquid crystal display panel, wherein a turning film is coupled to the optical wedge at the major surface that faces away from the liquid crystal display panel, and wherein the diffraction grating is formed on the turning film.

16. The display system of claim 13, wherein the diffraction grating serves as a turning film that redirects light emitted from the optical wedge toward the liquid crystal display panel.

17. The display system of claim 13, wherein the diffraction grating comprises a plurality of lines, and wherein the color filters are arranged in columns that run parallel to the lines of the diffraction grating.

18. The display system of claim 13, wherein the optical wedge has a direction of taper that is parallel to a long dimension of the display panel.

19. A method of operating a display system, comprising:

introducing white light from a light source into an optical wedge;

emitting the white light from the optical wedge;

turning the white light toward a display panel;

diffracting the white light to produce a plurality of bands of colored light; and

passing the plurality of bands of colored light through the display panel such that the plurality of bands of colored light pass through corresponding color filters of the display panel.

20. The method of claim 19, further comprising focusing the plurality of bands of colored light through the corresponding color filters of the display panel via a lens array.