Display

• US 8,262,271 B2
• Filed: 07/14/2009
• Issued: 09/11/2012
• Est. Priority Date: 07/17/2008
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Tillin, Martin David, Mather, Jonathan, Walton, Emma Jayne
• Primary Examiner(s): Neils, Peggy A.
• Application Number:
  US12/502,317
• Publication Number:
  US 20100014313A1
• Time in Patent Office: 1,155 Days
• Field of Search: 362/606, 362/626, 362/629, 362/327, 362/268, 362/331, 349/57, 349/95, 349/15, 359/619, 359/463, 345/32, 348/59
• US Class Current: 362/606
• CPC Class Codes: G02B 2027/0129 comprising devices for correcting parallax
• CPC Class Codes: G02B 27/0101 characterised by optical features G02B27/0172 takes precedence
• CPC Class Codes: G02B 3/0006 Arrays G02B3/02, G02B5/188 take precedence
• CPC Class Codes: G02B 6/00 Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings

Abstract

A display comprises: a single-view image display panel (6); and a parallax optic (8) disposed over a display face of the image display panel for restricting the angular spread of light output from the display face of the image display panel. This enables light to be concentrated in a desired viewing angle range (66), and avoids a user (56) seeing unwanted reflections that may occur as a result of a greater viewing angle range (64) if the parallax optic (8) is not provided. The display may be used, as an example, in a motor vehicle to prevent unwanted reflections from the windscreen (62) of the vehicle.

Claims

1. A display comprising:

a single-view image display panel; and

a parallax optic disposed over a display face of the image display panel for restricting an angular spread of light output from the display face of the image display panel;

wherein the display panel is a pixelated display panel and wherein an element of the parallax optic is associated with no more than one pixel of the display panel or with no more than one line of pixels of the display panel,

the elements of the parallax optic restrict the angular spread of light output from the display face of the image display panel in two orthogonal directions,

the elements of the parallax optic substantially collimates light output from the display face of the image display panel in a first of the orthogonal directions, and

the elements of the parallax optic restrict the angular spread of light output from the display face of the image display panel in a second of the orthogonal directions into a first angular range centered on an angle of approximately −

30°

with respect to a normal to the display and a second angular range centered on an angle of approximately +30°

with respect to the normal.

2. A display as claimed in claim 1 wherein a pitch of elements of the parallax optic is equal to the pitch of pixels of the display.

3. A display as claimed in claim 2 wherein each element of the parallax optic is offset with respect to an associated pixel of the display, in a direction parallel to the display face of the display.

4. A display as claimed in claim 1 wherein a pitch of elements of the parallax optic is less than the pitch of pixels of the display.

5. A display as claimed in claim 1 wherein a pitch of elements of the parallax optic is greater than the pitch of pixels of the display.

6. A display as claimed in claim 1 wherein a pitch of elements of the parallax optic is constant across the display.

7. A display as claimed in claim 1 wherein a pitch of elements of the parallax optic is not constant across the display.

8. A display as claimed in claim 1 wherein the parallax optic is a microlens array.

9. A display as claimed in claim 8 and wherein a spacing between the microlens array and the pixels of the image display panel is approximately equal to a focal length of the microlens array.

10. A display as claimed in claim 8 wherein the microlens array is integral with the display face of the image display panel.

11. A display as claimed in claim 8 and comprising a layer of material having a refractive index lower than the refractive index of the microlens array, the layer of material being disposed directly adjacent to the microlens array.

12. A display as claimed in claim 8 wherein the microlens array is spaced from the image display panel by material having a refractive index lower than the refractive index of the microlens array.

13. A display as claimed in claim 8 and wherein the parallax optic comprises light-absorbing material provided between lenses of the microlens array.

14. A display as claimed in claim 8 wherein the lenses are selected from the group consisting of cylindrical lenses, spherical lenses, rectangular lenses and square lenses.

15. A display as claimed in claim 8 wherein the lenses are plano-convex lenses.

16. A display as claimed in claim 8 wherein the lenses are bi-convex lenses.

17. A display as claimed in claim 1 wherein the elements of the parallax optic restrict the angular spread of light output from the display face of the image display panel in one direction.

18. A display as claimed in claim 1 and comprising a reflective material provided behind non-transmissive portions of the image display panel.

19. A display as claimed in claim 8 wherein the microlens array comprises an array of cylindrical lenses, each lens associated with a line of pixels.

20. A display as claimed in claim 1 where the image display panel is an emissive image display panel.

21. A display as claimed in claim 1 where the image display panel is a non-emissive image display panel.

22. A display as claimed in claim 21 wherein the image display panel is a liquid crystal display panel.

23. A display as claimed in claim 1 and for use in a motor vehicle.

24. A display as claimed in claim 1 and for use in an aircraft.

25. A parallax optic comprising:

an aperture array;

a microlens array for restricting an angular spread of light transmitted through the aperture array;

non-light transmissive material disposed between microlenses of the microlens array; and

a layer of material having lower refractive index than the microlens array, the layer of material being disposed directly adjacent to the microlens array,

wherein light transmitted through the aperture array passes through the layer of material having the lower refractive index.

26. A parallax optic as claimed in claim 25 wherein the aperture array is disposed on a first face of a substrate and the microlens array is disposed on a second face of the substrate, the first face being opposed to the second face.

27. A parallax optic as claimed in claim 25 wherein the aperture array is disposed on a first substrate and the microlens array is disposed on a second substrate, the first substrate being opposed to the second substrate.

28. A parallax optic as claimed in claim 25 and comprising reflective material disposed between the apertures of the aperture array for reflecting light incident on non-aperture portions of the aperture array.

29. A parallax optic as claimed in claim 25 and comprising an array of optical elements, the optical elements being disposed in respective apertures of the aperture array.

30. A parallax optic as claimed in claim 29 and wherein the array of optical elements comprises a second array of microlens.

31. A parallax optic as claimed in claim 25 and adapted to restrict in two orthogonal directions the angular spread of light transmitted through the aperture array.

32. A parallax optic as claimed in claim 31 and adapted to substantially collimate light in a first of the orthogonal directions.

33. A parallax optic as claimed in claim 32 and adapted to restrict the angular spread of light in a second of the orthogonal directions into a first angular range centred on an angle of approximately −

30°

with respect to a normal to the parallax optic and a second angular range centred on an angle of approximately +30°

with respect to the normal.

34. An illumination system comprising:

(a) an illumination panel comprising;

at least one light source;

a lightguide having first and second facing major surfaces, the first of which comprises an output surface for light, and a minor edge surface through which the at least one light source is arranged to introduce light into the lightguide; and

(b) a parallax optic as defined in claim 28 disposed over the output surface of the lightguide.

35. An illumination system as claimed in claim 34 wherein the parallax optic comprises an array of optical elements, the optical elements being disposed in respective apertures of the aperture array;

and wherein the optical elements make contact with the output surface of the lightguide thereby to provide light outcoupling points.

36. A parallax optic comprising:

an aperture array;

a microlens array for restricting an angular spread of light transmitted through the aperture array;

non-light transmissive material disposed between microlenses of the microlens array; and

a layer of material having lower refractive index than the microlens array, the layer of material being disposed directly adjacent to the microlens array,

wherein the parallax optic is adapted to restrict in two orthogonal directions the angular spread of light transmitted through the aperture array,

the parallax optic is adapted to substantially collimate light in a first of the orthogonal directions, and

the parallax optic is adapted to restrict the angular spread of light in a second of the orthogonal directions into a first angular range centered on an angle of approximately −

30°

with respect to a normal to the parallax optic and a second angular range centered on an angle of approximately +30°

with respect to the normal.