SHAPED FRONTLIGHT REFLECTOR FOR USE WITH DISPLAY

• US 20100226118A1
• Filed: 03/06/2009
• Published: 09/09/2010
• Est. Priority Date: 03/06/2009
• Status: Active Grant

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: Qualcomm MEMS Technologies Incorporated (Qualcomm, Inc.)
• Inventors: Baar, Kenneth W.
• Granted Patent: US 8,172,417 B2
• Time in Patent Office: Days
• US Class Current: 362/97.100
• CPC Class Codes: G02B 26/001 based on interference in an adjustable optical cavity interference filters G02B5/28; devices or arrangements using multiple reflections in spectrometry or monochromators G01J3/26
• CPC Class Codes: G02B 6/0028 Light guide, e.g. taper
• CPC Class Codes: G02B 6/0031 Reflecting element, sheet or layer

Abstract

In order to minimize the footprint of a display module, a frontlight system positioned over a first surface of a substrate may be used. The frontlight system may include an edgebar positioned over the first surface of a display substrate, and a Z-shaped reflector having a first planar portion overlying the edgebar and a second planar portion adhered to the first surface of the substrate or layers overlying the first surface of the substrate. Such a reflector may be located wholly within the footprint of the display substrate, minimizing the footprint of the display module.

Claims

1. A display module, comprising:

a light-transmissive substrate comprising a first surface and a second surface;

an edgebar in optical communication with a light source, wherein the edgebar is located over the first surface of the substrate;

a frontlight film adjacent the edgebar and in optical communication with the edge bar, wherein the frontlight film is configured to direct light through the light-transmissive substrate; and

a reflector, the reflector comprising a first substantially planar portion overlying the edgebar and a second substantially planar portion located over the first surface of the substrate and laterally displaced from the edgebar.

2. The display module of claim 1, wherein the edgebar comprises a front surface facing a side surface of the frontlight film and a second surface oriented substantially orthogonally to the front surface.

3. The display module of claim 2, wherein the first planar portion of the reflector extends over the front surface of the edgebar.

4. The display module of claim 3, wherein the first planar portion of the reflector is oriented substantially orthogonally to the front surface of the edgebar.

5. The display module of claim 2, further comprising a light source located adjacent the second surface of the edgebar and configured to emit light into the edgebar.

6. The display module of claim 5, wherein the light source comprises at least one LED.

7. The display module of claim 6, wherein said at least one LED is supported by a stiffener which extends over at least a portion of the first planar portion of the reflector.

8. The display module of claim 1, wherein the reflector comprises at least one aperture extending therethrough, and wherein the edgebar comprises a connector portion which extends through said aperture.

9. The display module of claim 8, wherein the connector portion comprises a distal section located on the opposite side of the reflector from the remainder of the edgebar, and wherein at least a portion of the distal section has a cross-sectional size which is larger than the cross-sectional size of the aperture.

10. The display module of claim 8, wherein the connector portion comprises a heat stake.

11. The display module of claim 1, further comprising a layer of reflective material located between the edgebar and the substrate.

12. The display module of claim 11, further comprising a driver IC located over the second surface of the substrate, wherein the layer of reflective material is disposed between the edgebar and the driver IC.

13. The display module of claim 1, further comprising a display array disposed over the second surface of the substrate, wherein the display array is positioned opposite the frontlight film.

14. The display module of claim 13, wherein the display array comprises an array of interferometric modulators.

15. The display module of claim 13, further comprising:

a processor that is configured to communicate with said display array, said processor being configured to process image data; and

a memory device that is configured to communicate with said processor.

16. The display module of claim 15, further comprising a driver circuit configured to send at least one signal to said display array.

17. The display module of claim 16, further comprising a controller configured to send at least a portion of said image data to said driver circuit.

18. The display module of claim 15, further comprising an image source module configured to send said image data to said processor.

19. The display module of claim 18, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

20. The display module of claim 15, further comprising an input device configured to receive input data and to communicate said input data to said processor.

21. An edgebar subassembly configured for use in a display module, the edgebar subassembly comprising:

an edgebar configured to receive light through a first surface and reflect light through a second surface orthogonal to said first surface; and

a reflector configured to retain the edgebar, the reflector comprising;

a first substantially planar portion configured to overlie the edgebar; and

a second substantially planar portion configured to be adhered to an underlying layer;

wherein a lower surface of the second substantially planar portion is substantially coplanar with a lower surface of the edgebar, and the edgebar is retained by the reflector.

22. The edgebar subassembly of claim 21, wherein the second planar portion of the reflector is laterally displaced with respect to the edgebar.

23. The edgebar subassembly of claim 21, wherein the lower surface of the edgebar is substantially orthogonal to each of the first and second surfaces of the edgebar.

24. The edgebar subassembly of claim 21, wherein the reflector comprises an aperture extending through the reflector, additionally comprising a heat stake extending from the edgebar through said aperture to retain the edgebar relative to the reflector.

25. A method of assembling a display module, comprising:

providing a substrate having a first and second surface, the substrate comprising a display array formed over said first surface and a light-guiding layer located over said second surface, wherein the light-guiding layer is located opposite the display array;

positioning an edgebar relative to the substrate such that a first surface of the edgebar is positioned adjacent a side surface of the light-guiding layer; and

providing a reflector over said first surface of the substrate such that the reflector retains the edgebar in place, the reflector comprising a first substantially planar portion overlying the edgebar and a second substantially planar portion displaced from the edgebar and adhered to an underlying layer.

26. The method of claim 25, additionally comprising forming a reflective layer over the first surface of the substrate prior to securing the reflector over the first surface of the substrate, wherein the reflective layer is disposed between the edgebar and the substrate.

27. The method of claim 25, additionally comprising positioning a light source adjacent to a second surface of the edgebar, wherein the second surface of the edgebar is substantially orthogonal to the first surface of the edgebar.

28. The method of claim 27, wherein positioning a light source adjacent to a second surface of the edgebar comprises adhering an LED subassembly to an upper surface of the first planar portion of the reflector, wherein the LED subassembly comprises:

at least one LED;

a flexible circuit board in electrical communication with the LED; and

a stiffener overlying the flexible circuit board.