Optical films for controlling angular characteristics of displays

• US 7,508,571 B2
• Filed: 06/17/2005
• Issued: 03/24/2009
• Est. Priority Date: 09/27/2004
• Status: Expired due to Fees

• Current Assignee: Snaptrack Incorporated (Qualcomm, Inc.)
• Original Assignee: IDC, LLC
• Inventors: Gally, Brian J., Cummings, William J.
• Primary Examiner(s): Mack; Ricky
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US11/156,335
• Publication Number:
  US 20060077123A1
• Time in Patent Office: 1,376 Days
• Field of Search: 359/290, 359/291, 359/292, 359/295, 359/298, 359/220, 359/223, 359/224, 359/320, 359/322, 359/324, 359/900
• US Class Current: 359/291
• 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 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In various embodiments of the invention, an interferometric display device is provided having an external film with a plurality of structures that reduce the field-of-view of the display. These structures may comprise, for example, baffles or non-imaging optical elements such as compound parabolic collectors. The baffles may comprise a plurality of vertically aligned surfaces arranged, e.g., in a grid. In certain preferred embodiments these baffles are opaque or reflective. These vertical surfaces, therefore, can substantially block light from exiting the interferometric display device in a substantially non-perpendicular direction. These vertical surfaces may, however, permit light directed in a substantially vertical direction to exit the display. The non-imaging optical elements, e.g., compound parabolic collectors, redirect light from large incident angles into more normal angles towards the display. As a result, the light reflected by the display to the user is also at a more normal angle.

Claims

1. A display comprising:

a light-modulating array comprising a plurality of light-modulating elements including first and second optical surfaces, the second optical surface movable with respect to the first optical surface; and

a plurality of baffles configured to limit a field-of-view of light provided by the plurality of light-modulating elements of the display,

wherein the plurality of baffles comprise spacings between individual baffles, said spacing having a dimension that provides a view angle of not more than about 40 degrees from a plane normal to a front surface of the display, wherein the angle is measured as a half-angle with respect to the normal plane.

2. The display of claim 1, wherein the plurality of baffles is incorporated in an optical layer formed over the light-modulating array.

3. The display of claim 1, wherein the light-modulating array is in a horizontal plane and the plurality of baffles comprise substantially planar surfaces that are parallel to a vertical plane.

4. The display of claim 1, wherein the plurality of baffles comprise spacings between individual baffles, said spacing having a dimension that provides a view angle of not more than about 20 degrees from a plane normal to a front surface of the display, wherein the angle is measured as a half angle with respect to the normal plane.

5. The display of claim 1, wherein the plurality of baffles are substantially opaque.

6. The display of claim 5, wherein the plurality of baffles comprise substantially planar opaque surfaces.

7. The display of claim 1, wherein the plurality of baffles comprises absorbing material.

8. The display of claim 1, wherein the plurality of baffles comprises a reflecting material.

9. The display of claim 1, further comprising:

a processor that is in electrical communication with the light-modulating array, said processor being configured to process image data; and

a memory device in electrical communication with said processor.

10. The display of claim 9, further comprising:

a first controller configured to send at least one signal to the light-modulating array; and

a second controller configured to send at least a portion of said image data to said first controller.

11. The display of claim 9, further comprising an image source module configured to send said image data to said processor.

12. The display of claim 11, wherein said image source module comprises at least one of a receiver, transceiver, and transmitter.

13. The display of claim 9, further comprising an input device configured to receive input data and to communicate said input data to said processor.

14. A display comprising:

a light-modulating array comprising a plurality of light-modulating elements including first and second optical surfaces, the second optical surface movable with respect to the first optical surface; and

a plurality of elements configured to limit a field-of-view of light provided by the display,

wherein the plurality of elements configured to limit a field-of-view of the display comprise an array of light collectors comprising curved reflective surfaces shaped to collect light incident at a wide range of angles and direct the light into at a narrower range of angles onto the light-modulating elements, and

wherein the plurality of elements restrict the field-of-view of the display to angles no more than about 70 degrees from a plane normal to a front surface of the display, wherein the angle is measured as a half angle with respect to the normal plane.

15. The display of claim 14, wherein said light collectors comprise non-imaging optical elements.

16. The display of claim 15, wherein said non-imaging optical elements comprise compound parabolic collectors.

17. The display of claim 14, wherein said reflective surfaces are symmetric about central optical axes passing through the light collectors.

18. The display of claim 14, wherein said light collectors are circularly symmetric about central optical axes passing through the light collectors.

19. The display of claim 14, wherein said curved reflective surfaces define input and output apertures for said light collectors, said output apertures being larger than said input apertures.

20. The display of claim 14, wherein the curved reflective surfaces are shaped to substantially collimate light.

21. A display comprising:

a light-modulating array comprising a plurality of light-modulating elements including first and second optical surfaces, the second optical surface movable with respect to the first optical surface; and

a plurality of elements configured to limit a field-of view-of light provided by the display,

wherein the plurality of elements configured to limit a field-of-view of the light provided by the display comprise an array of light collectors comprising curved reflective surfaces shaped to collect light incident at a wide range of angles and direct the light into at a narrower range of angles onto the light-modulating elements, and

wherein the plurality of elements restrict the field-of-view of the display to angles no more than about 20 degrees from a plane normal to a front surface of the display, wherein the angle is measured as a half angle with respect to the normal plane.