Display With Focussed Illumination

• US 20080225205A1
• Filed: 03/12/2008
• Published: 09/18/2008
• Est. Priority Date: 03/13/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Travis, Adrian Robert Leigh
• Granted Patent: US 8,085,364 B2
• Time in Patent Office: Days
• US Class Current: 349/65
• CPC Class Codes: G02B 6/0018 Redirecting means on the surface of the light guide
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0046 Tapered light guide, e.g. wedge-shaped light guide
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0068 Arrangements of plural sources, e.g. multi-colour light sources
• CPC Class Codes: G02B 6/0073 Light emitting diode [LED]
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• 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 1/133613 characterized by the sequence of light sources
• 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
• CPC Class Codes: G02F 1/133622 Colour sequential illumination
• CPC Class Codes: G02F 2203/34 Colour display without the use of colour mosaic filters

Abstract

A liquid crystal display with focused illumination is described. In an example, a light-source emitting a plurality of discrete colors is focused onto a liquid crystal display panel. The liquid crystal display panel has a plurality of pixels and each pixel has regions corresponding to the colors emitted by the light-source. Light of each color is focused onto the regions of the pixels corresponding to that color.

Claims

1. A display apparatus, comprising

a backlight emitting a plurality of colors of light,

a liquid crystal panel comprising a plurality of pixels, each pixel having a plurality of regions, each region corresponding to one of the colors emitted by the backlight, and

a focusing element, configured to focus the light of each of the colors emitted by the backlight onto regions corresponding to each of the colors.

2. A display apparatus according to claim 1, wherein

the colors are red, green and blue.

3. A display apparatus according to claim 1, wherein

the focusing element is a lenslet array having a plurality of lenslets.

4. A display apparatus according to claim 3, wherein

the lenslets of the lenslet array are columns to focus the light in a plane perpendicular to the columns.

5. A display apparatus according to claim 4, wherein

one column of pixels corresponds to one of the lenslets.

6. A display apparatus according to claim 1, wherein

the backlight comprises a plurality of groups of light-sources, each group emitting at least one of the colors.

7. A display apparatus according to claim 6, wherein

the focusing element is a lenslet array, and

a plurality of lenslets of the lenslet array focus light of a particular color onto a particular pixel.

8. A display apparatus according to claim 1, further comprising one or more mirrors arranged in a plane perpendicular to the liquid crystal panel between the backlight and the focusing element.

9. A display apparatus according to claim 3, wherein

the lenslets of the lenslet array focus light in two planes.

10. A display apparatus according to claim 1, further comprising

a tapered light-guide to guide light from the backlight to the focusing element, the backlight being arranged to inject light into a thick-end of the tapered light-guide, and the tapered light-guide being arranged to eject light from a face of the light-guide to the focusing element.

11. A display apparatus according to claim 10, further comprising a prismatic sheet between the face of ejection of the tapered light-guide and the focusing element such that light enters the focusing element perpendicular to the plane of the focusing element.

12. A display apparatus according to claim 10, wherein

the tapered light-guide comprises a tapered region and an extension region, wherein the extension region extends from the thick end of the tapered region.

13. A display apparatus according to claim 12, wherein

the tapered light-guide is a folded light-guide and comprises a prismatic region to guide light around the folded light-guide.

14. A display apparatus according to claim 10, wherein a pitch of the focusing element varies over the area of the focusing element.

15. A display apparatus according to claim 1 wherein the focusing element is a hologram.

16. A display apparatus, comprising

a backlight emitting red, green and blue light,

a liquid crystal panel comprising a plurality of pixels, each pixel comprising red, green and blue regions, and

a focusing element configured to focus the red, green and blue light onto a corresponding region of each pixel.

17. A display apparatus according to claim 16, wherein the focusing element is a lenslet array.

18. A display apparatus, comprising

a backlight comprising red, green and blue light-sources,

a liquid crystal display comprising a plurality of pixels arranged in columns, each pixel comprising red, green and blue regions, and

a lenslet array comprising a plurality of lenslet columns, wherein the lenslet array focuses light from the red, green and blue light-sources onto columns of regions corresponding to the color of the light-source.