Directional backlight

• US 9,835,792 B2
• Filed: 10/07/2015
• Issued: 12/05/2017
• Est. Priority Date: 10/08/2014
• Status: Active Grant

• Current Assignee: Reald Spark, LLC
• Original Assignee: Reald Spark, LLC
• Inventors: Harrold, Jonathan, Woodgate, Graham J.
• Primary Examiner(s): Neils, Peggy
• Application Number:
  US14/877,196
• Publication Number:
  US 20160131825A1
• Time in Patent Office: 790 Days
• CPC Class Codes: G02B 6/0048 with stepwise taper
• CPC Class Codes: G02B 6/0055 Reflecting 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: G02B 6/0083 Details of electrical connections of light sources to drivers, circuit boards, or the like
• CPC Class Codes: G02B 6/0085 Means for removing heat created by the light source from the package heat extraction or cooling elements for semiconductor light sources in general H01L33/64
• CPC Class Codes: G02B 6/0086 Positioning aspects
• CPC Class Codes: G02F 1/1323 Arrangements for providing a switchable viewing angle
• CPC Class Codes: G02F 1/133601 for spatial active dimming
• CPC Class Codes: G02F 1/133603 with LEDs
• CPC Class Codes: G02F 1/133612 Electrical details
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 1/133628 with cooling means
• CPC Class Codes: H01L 25/00 Assemblies consisting of a plurality of individual semiconductor or other solid state devices ; Multistep manufacturing processes thereofdevices consisting of a plurality of solid state components formed in or on a common substrate H01L27/00; photovoltaic modules or arrays of photovoltaic cells H01L31/042 ; panels or arrays of photo electrochemical cells H01G9/2068
• CPC Class Codes: H05K 1/05 Insulated conductive substrates, e.g. insulated metal substrate
• CPC Class Codes: H05K 2201/10106 Light emitting diode [LED]

Abstract

An electrical connection assembly for a directional display comprising a directional backlight may include stack of flat connectors and a strip comprising an end portion with an array of light sources and a base portion with an array of connectors. The end portion and base portion may be shaped so that the base portion extends outwardly from the end portion. Light sources of the directional display may be individually addressable by means of a highly compact arrangement of connections, achieving low thickness and small bezel width.

Claims

1. A light source array parallel connection assembly for a directional backlight, the assembly comprising:

a mounting strip including an electrical insulator layer extending in a lateral direction, the mounting strip including an end portion and a base portion;

an array of light sources mounted to the end portion of the mounting strip arrayed in said lateral direction, and arranged to output light in a forward direction;

separate conductive tracks connected to each respective light source formed on the electrical insulator layer of the mounting strip and extending from the end portion onto the base portion; and

plural flat connectors, each comprising an array of separate conductive tracks, the flat connectors being mounted in a stack on the base portion of the mounting strip, each conductive track on the mounting strip being electrically connected to a respective conductive track of one of the flat connectors, the flat connectors extending in said lateral direction along the base portion to outside the base portion, allowing electrical connection to be made to the conductive tracks of the flat connectors outside the base portion.

2. An assembly according to claim 1, wherein each conductive track on the mounting strip is directly electrically connected to a respective conductive track of one of the flat connectors.

3. An assembly according to claim 1, wherein the mounting strip further comprises a heat sink layer extending at least across said end portion on the opposite side of the electrical insulator layer from the conductive tracks.

4. An assembly according to claim 3, wherein the heat sink layer extends across the end portion and the base portion.

5. An assembly according to claim 3, wherein the heat sink layer comprises a layer of metal.

6. An assembly according to claim 5, wherein the metal is copper.

7. An assembly according to claim 3, comprising a further heat sink element thermally connected to the heat sink layer adjacent the end portion.

8. An assembly according to claim 1, further comprising respective connector blocks connected to each flat connector outside the base portion, which connector blocks allow electrical connection to be made to the conductive tracks of the flat connectors.

9. An assembly according to claim 1, wherein the conductive tracks of each flat connector are exposed outside the base portion to allow electrical connection to be made to them.

10. An assembly according to claim 1, wherein the end portion is planar and base portion is planar.

11. An assembly according to claim 1, wherein the base portion extends in the forward direction from the light sources.

12. An assembly according to claim 1, wherein the light sources are mounted to the mounting strip on a face of the end portion in a top-emitting configuration so that the forward direction is outwardly of the face.

13. An assembly according to claim 12, wherein the mounting strip is shaped so the base portion extends in the forward direction.

14. An assembly according to claim 12, wherein the mounting strip is shaped so that the base portion is disposed on the rearward side of the end portion.

15. An assembly according to claim 14, wherein the mounting strip is shaped so that the base portion is disposed on the rearward side of the end portion extending parallel to the end portion.

16. An assembly according to claim 1, wherein the light sources are mounted to the mounting strip on a face of the end portion in a side-emitting configuration so that the forward direction is across the face.

17. An assembly according to claim 16, wherein the base portion extends in the forward direction.

18. An assembly according to claim 16, wherein the base portion extends in the rearward direction.

19. A directional backlight comprising:

a waveguide comprising an input end for receiving input light and first and second, opposed guide surfaces for guiding input light along the waveguide, wherein the second guide surface is arranged to deflect light guided through the waveguide out of the waveguide through the first guide surface as output light, and the waveguide is arranged to direct the output light into optical windows in output directions that are distributed laterally in dependence on the input position of the input light laterally along the input end; and

an assembly according to claim 1 arranged with the light sources disposed at different input positions laterally along the input end of the waveguide, facing the input end of the waveguide for supplying said input light.

20. A directional display device comprising:

a directional backlight according to claim 19; and

a transmissive spatial light modulator comprising an array of pixels arranged to receive the output light from the waveguide and to modulate it to display an image.

21. A directional display apparatus comprising:

a directional display device according to claim 20; and

a control system connected to the flat connectors outside the base portion for providing connection to the light sources, the control system being arranged to control the light sources to direct light into optical windows for viewing by an observer.