SEGMENTED EDGE-LIT BACKLIGHT ASSEMBLY FOR A DISPLAY

• US 20130321496A1
• Filed: 05/29/2012
• Published: 12/05/2013
• Est. Priority Date: 05/29/2012
• Status: Active Grant

• Current Assignee: Gentex Corporation
• Original Assignee: Gentex Corporation
• Inventors: Weller, Andrew D., VanderPloeg, John A., Lee, Ethan J.
• Granted Patent: US 8,878,882 B2
• Time in Patent Office: Days
• US Class Current: 345/694
• CPC Class Codes: G02B 6/0078 Side-by-side arrangements, e.g. for large area displays
• CPC Class Codes: G02F 1/133615 Edge-illuminating devices, i.e. illuminating from the side
• CPC Class Codes: G02F 2201/465 Snap -fit
• CPC Class Codes: G09G 2380/10 Automotive applications
• CPC Class Codes: G09G 3/3406 Control of illumination source illumination devices structurally associated with liquid crystal cells G02F1/1336

Abstract

An edge-lit backlight assembly is provided for backlighting a display. The backlight assembly may include: a light guide having a first segment and a second segment disposed within a common plane; a first light emitting diode disposed along an edge of the first segment of the light guide such that light emitted from the first light emitting diode propagates through the first segment; and a second light emitting diode disposed along an edge of the second segment of the light guide such that light emitted from the second light emitting diode propagates through the second segment. The first segment of the light guide is at least partially optically isolated from the second segment such that light emitted from the first light emitting diode is at least partially blocked from propagating through the second segment.

Claims

1. An edge-lit backlight assembly for backlighting a display, comprising:

a light guide having a first segment and a second segment disposed within a common plane;

a first light source disposed along an edge of said first segment of said light guide such that light emitted from said first light source propagates through said first segment; and

a second light source disposed along an edge of said second segment of said light guide such that light emitted from said second light source propagates through said second segment,

wherein said first segment of said light guide is at least partially optically isolated from said second segment such that light emitted from said first light source is at least partially blocked from propagating through said second segment.

2. The edge-lit backlight assembly of claim 1, wherein said first segment of said light guide is at least partially optically isolated from said second segment by a gap provided therebetween.

3. The edge-lit backlight assembly of claim 2, wherein said first segment includes an opposed edge that opposes said gap and wherein a light blocker is disposed along said opposed edge of said first segment.

4. The edge-lit backlight assembly of claim 1, wherein said first segment includes an outer first edge along which said first light emitting diode is disposed, an outer second edge joining said first edge at an outer corner of said light guide, and an inner third edge joining said second edge, wherein said second and third edges join to form an acute angle, and wherein said third edge extends substantially parallel to a corresponding inner edge of said second segment.

5. The edge-lit backlight assembly of claim 4, wherein said third edge also joins said first edge such that said first segment is shaped as a triangle.

6. The edge-lit backlight assembly of claim 4, wherein said first segment further includes an inner fourth edge extending between and joining said first and third edges and extends substantially parallel to another corresponding inner edge of said second segment such that said first segment is shaped as a quadrangle.

7. The edge-lit backlight assembly of claim 4, wherein a gap is provided between said third edge of said first segment and said corresponding edge of said second segment.

8. The edge-lit backlight assembly of claim 7, wherein a light blocker is disposed on said third edge of said first segment.

9. The edge-lit backlight assembly of claim 7, wherein a light blocker is disposed on said corresponding edge of said second segment.

10. A display, comprising:

a display element having a display area from which information is displayed, a select portion of said display area for displaying select information; and

an edge-lit backlight assembly for backlighting said display element, said edge-lit backlight assembly comprising;

a light guide having a first segment and a second segment, where said first segment backlights said select portion of said display area and said second segment backlights a remaining portion of said display area;

a first light emitting diode disposed along an edge of said first segment of said light guide such that light emitted from said first light emitting diode propagates through said first segment and backlights said select portion of said display area; and

a plurality of second light emitting diodes disposed along an edge of said second segment of said light guide such that light emitted from said second light emitting diodes propagates through said second segment and backlights said remaining portion of said display area,

wherein said first segment of said light guide is at least partially optically isolated from said second segment such that light emitted from said first light emitting diode is at least partially blocked from propagating through said second segment and thereby at least partially blocked from backlighting the remaining portion of said display area.

11. The display of claim 10, wherein video images are displayed over the full display area of said display element.

12. The display of claim 10, wherein the select information includes at least one of:

an alphanumeric character and graphic symbol.

13. The display of claim 10, wherein said display element is a liquid crystal display.

14. The display of claim 10, wherein said first segment of said light guide is at least partially optically isolated from said second segment by a gap provided therebetween.

15. The display of claim 14, wherein said first segment includes an opposed edge that opposes said gap and wherein a light blocker is disposed along said opposed edge of said first segment.

16. A display for a vehicle, comprising:

a display element having a display area from which video images are displayed over the full display area, a select portion of said display area for displaying select information; and

an edge-lit backlight assembly for backlighting said display element, said edge-lit backlight assembly comprising;

a light guide having a first segment and a second segment, where said first segment backlights said select portion of said display area and said second segment backlights a remaining portion of said display area;

at least one first light emitting diode disposed along an edge of said first segment of said light guide such that light emitted from said at least one first light emitting diode propagates through said first segment and backlights said select portion of said display area; and

a plurality of second light emitting diodes disposed along an edge of said second segment of said light guide such that light emitted from said second light emitting diodes propagates through said second segment and backlights said remaining portion of said display area,

wherein said first segment of said light guide is at least partially optically isolated from said second segment such that light emitted from said at least one first light emitting diode is at least partially blocked from propagating through said second segment and thereby at least partially blocked from backlighting the remaining portion of said display area,

wherein, when video images are displayed over the full display area, said at least one first light emitting diode and said plurality of second light emitting diodes are energized to backlight all of said display area, and

wherein, when the select information is displayed on said select portion of said display area, said at least one first light emitting diode is energized to backlight said select portion while said plurality of second light emitting diodes are de-energized such that the remaining portion is not backlit.

17. The display of claim 16, wherein the select information includes at least one of:

an alphanumeric character and graphic indicia.

18. The display of claim 16, wherein the select information includes a compass heading.

19. The display of claim 16, wherein the video images are obtained from a camera having a field of view to the rear of the vehicle.

20. The display of claim 19, wherein the video images are displayed when the vehicle is in reverse gear.

21. The display of claim 16, wherein said display is a liquid crystal display.

22. The display of claim 16, wherein said at least one first light emitting diode includes a white-light-emitting light emitting diode and another light emitting diode that emits light of a non-white color.

23. The display of claim 22, wherein:

said plurality of second light emitting diodes emit white light,

when video images are displayed over the full display area, said white-light-emitting light emitting diode of said at least one first light emitting diode and said plurality of second light emitting diodes are energized to backlight all of said display area with white light, and

when the select information is displayed on said select portion of said display area, another light emitting diode of said at least one first light emitting diode is energized to backlight said select portion with a non-white color while said plurality of second light emitting diodes and said white-light-emitting light emitting diode of said at least one first light emitting diode are de-energized such that the remaining portion is not backlit.

24. The display of claim 16, wherein said at least one first light emitting diode is controlled to emit either white light or light of another color.

25. A rearview assembly for a vehicle comprising the display of claim 16.