Directional display apparatus

• US 7,796,318 B2
• Filed: 05/28/2008
• Issued: 09/14/2010
• Est. Priority Date: 09/30/2003
• Status: Active Grant

• Current Assignee: AU Optronics Corporation
• Original Assignee: AU Optronics Corporation
• Inventors: Harrold, Jonathan, Woodgate, Graham John
• Primary Examiner(s): Mack; Ricky L
• Assistant Examiner(s): Tra; Tuyen Q
• Application Number:
  US12/128,064
• Publication Number:
  US 20080273242A1
• Time in Patent Office: 839 Days
• Field of Search: 359/237, 359/245, 359/248, 359/254, 359/463, 359/462, 359/455, 359/494, 359/642, 359/733, 359/622, 359/624, 345/32, 345/33, 345/204, 345/419, 348/40, 348/41, 348/42, 348/51, 396/324, 349/15
• US Class Current: 359/237
• CPC Class Codes: G02B 3/0037 characterized by the distribution or form of lenses
• CPC Class Codes: G02B 3/0056 arranged along two different directions in a plane, e.g. honeycomb arrangement of lenses G02B3/0043 takes precedence; miniaturised objectives for electronic devices employing wafer level optics G02B13/0085
• CPC Class Codes: G02B 3/0068 arranged in a single integral body or plate, e.g. laminates or hybrid structures with other optical elements G02B5/1885, G02B17/002, G02B30/27 take precedence
• CPC Class Codes: G02B 30/27 involving lenticular arrays
• CPC Class Codes: G02B 30/29 characterised by the geometry of the lenticular array, e.g. slanted arrays, irregular arrays or arrays of varying shape or size
• CPC Class Codes: H04N 13/31 using parallax barriers
• CPC Class Codes: H04N 13/359 Switching between monoscopic and stereoscopic modes

Abstract

A directional display apparatus, comprising a spatial light modulator comprising an array of pixels and a lens array in which each respective section of the lens array is capable of directing light from a group of pixels aligned with the respective section into nominal viewing windows, is arranged such that each respective section is also capable of directing light from at least one adjacent group of pixels aligned with a section adjacent the respective section into the same nominal viewing windows. This may be achieved by a deflection element, such as a prism element or a hologram, or by each respective section of the lens array having at least one lens surface providing: at least one first region capable of directing light from said group of pixels aligned with the respective section into said nominal viewing windows; and at least one second region capable of directing light from said at least one adjacent group of pixels into the same nominal viewing windows. By mixing light from adjacent groups of pixels, striped visual artefacts are reduced.

Claims

1. A directional display apparatus comprising:

a spatial light modulator comprising an array of pixels; and

a lens array having a structure which repeats substantially at a predetermined pitch,

wherein the lens array is arranged such that each respective section of the lens array at said pitch is formed to provide;

a plurality of first lens facets operable for directing first light beams from at least one pixel aligned with the respective section into at least one nominal viewing window; and

a plurality of second lens facets operable for directing second light beams from at least one adjacent pixel aligned with a section adjacent the respective section into the same at least one nominal viewing window,

wherein each of the first lens facets is arranged alternately with each of the second lens facets to form a continuous lens surface, the first and second lens facets are all of no vertical facets,

wherein all the light beams outputted from all the lens facets are substantially in parallel with one another.

2. A directional display apparatus according to claim 1, wherein the lens array is a birefringent lens array.

3. A directional display apparatus according to claim 2, wherein the birefringent lens array is a passive element and the directional display apparatus further comprises a switchable polariser arranged to control the polarisation component of all the light beams passing through the lens array and output from the directional display apparatus.

4. A directional display apparatus according to claim 2, wherein the birefringent lens array is an active element which is switchable to control the effect of the lens array.

5. A directional display apparatus according to claim 2, wherein the directional display apparatus is arranged such that each respective section is also operable for directing light from at least one adjacent pixel aligned with sections adjacent the respective section on opposite sides of said respective section into the same at least one nominal viewing windows.

6. A directional display apparatus comprising:

a spatial light modulator comprising an array of pixels; and

a lens array having a refractive structure which repeats substantially at a predetermined pitch,

wherein the lens array is arranged such that each respective section of the lens array at said pitch is formed to provide;

at least one first region operable for directing light from at least one pixel aligned with the respective section into at least one nominal viewing window; and

at least one second region operable for directing light from at least one adjacent pixel aligned with a section adjacent the respective section into the same at least one nominal viewing window,

wherein the first region is arranged alternately with the second lens region to form a continuous lens surface, the first and second regions are both of no vertical facets.

7. A directional display apparatus according to claim 6, wherein the lens array is a birefringent lens array.

8. A directional display apparatus according to claim 7, wherein the birefringent lens array is a passive element and the directional display apparatus further comprises a switchable polariser arranged to control the polarisation component of all the light beams passing through the lens array and output from the directional display apparatus.

9. A directional display apparatus according to claim 7, wherein the birefringent lens array is an active element which is switchable to control the effect of the lens array.

10. A directional display apparatus according to claim 7, wherein the directional display apparatus is arranged such that each respective section is also operable for directing light from at least one adjacent pixel aligned with sections adjacent the respective section on opposite sides of said respective section into the same at least one nominal viewing windows.