Structured optical film

• US 7,744,263 B2
• Filed: 12/16/2005
• Issued: 06/29/2010
• Est. Priority Date: 12/16/2004
• Status: Expired due to Fees

• Current Assignee: Microsharp Corporation Limited
• Original Assignee: Microsharp Corporation Limited
• Inventors: Bottomley, David John
• Primary Examiner(s): Alavi; Ali
• Application Number:
  US11/721,410
• Publication Number:
  US 20090279280A1
• Time in Patent Office: 1,656 Days
• Field of Search: 362/618, 362/620, 362/627, 362/341, 362/331, 362/332, 359/831, 359/621, 359/837, 359/834, 428/172, 428/156, 349/57
• US Class Current: 362/618
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0038 Linear indentations or grooves, e.g. arc-shaped grooves or meandering grooves, extending over the full length or width of the light guide
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity

Abstract

Disclosed are structured optical films and optical displays incorporating such films. The film has a structured surface including a plurality of substantially parallel and elongate light-directing elements. Each element has a respective peak and defining at a junction with an adjacent element a respective valley. Each of the peaks and valleys define substantially the same dihedral angle and extend substantially uninterrupted across the structured surface. A first sequence defined by successive lateral distances between adjacent peaks is a first non-periodic sequence. A second sequence defined by successive lateral distances between adjacent valleys is a second non-periodic sequence. The second sequence is configured based on the first sequence, such that the peaks are arranged in a substantially coplanar formation. Alternatively, the first sequence is configured based on the second sequence, such that the valleys are arranged in a substantially coplanar formation.

Claims

1. A structured optical film having a structured surface extending longitudinally between a first end and a second end and laterally between a first side face and a second side face, the structured surface comprising a plurality of substantially parallel and elongate light-directing elements, each element having a respective peak and defining at a junction with an adjacent element a respective valley, each of the peaks and valleys defining substantially the same dihedral angle and extending substantially uninterrupted across the structured surface between the first and second ends, wherein a first sequence defined by successive lateral distances between adjacent peaks from the first side face to the second side face is a first non-periodic sequence and a second sequence defined by successive lateral distances between adjacent valleys from the first side face to the second side face is a second non-periodic sequence, the second sequence being configured based on the first sequence, such that the peaks are arranged in a substantially coplanar formation and the valleys are arranged in a substantially non-coplanar formation.

2. The film of claim 1, wherein the peaks are substantially coplanar in that there exists a plane from which each respective peak is distant by no more than about 1.0 μ

m.

3. The film of claim 1, wherein the peaks are substantially coplanar in that there exists a plane from which each respective peak is distant by no more than about 0.5 μ

m.

4. The film of claim 1, wherein the peaks are substantially coplanar in that there exists a plane from which each respective peak is distant by no more than about 0.2 μ

m.

5. The film of claim 1, wherein the lateral distance between each pair of adjacent valleys having a first peak adjacent one side of the pair and a second peak adjacent the other side of the pair is half the lateral distance between the first and second peaks.

6. The film of claim 1, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 1.2 or greater.

7. The film of claim 1, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 1.5 or greater.

8. The film of claim 1, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 2.0 or greater.

9. An optical display assembly comprising:

a display panel;

a backlight assembly; and

a structured optical film according to claim 1, the film being located between the backlight assembly and the display panel.

10. The optical display assembly of claim 9, further comprising a second structured optical film, the second structured optical film being located between the backlight assembly and the first structured optical film and the second structured optical film having a structured optical surface comprising a plurality of elongate prisms, where the films are oriented such that the elongate elements of the second film are substantially crossed with respect to the elongate elements of the first film.

11. An optical display assembly comprising:

a display panel;

a light source; and

a structured optical film according to claim 1, the film being located between the light source and the display panel.

12. The film of claim 1, wherein the first non-periodic sequence is generated based on consecutive decimal digits of pi.

13. The film of claim 1, wherein each value in the second non-periodic sequence equals half the sum of an adjacent pair of peak distances.

14. A structured optical film having a structured surface extending longitudinally between a first end and a second end and laterally between a first side face and a second side face, the structured surface comprising a plurality of substantially parallel and elongate light-directing elements, each element having a respective peak and defining at a junction with an adjacent element a respective valley, each of the peaks and valleys defining substantially the same dihedral angle and extending substantially uninterrupted across the structured surface between the first and second ends, wherein a first sequence defined by successive lateral distances between adjacent peaks from the first side face to the second side face is a first non-periodic sequence and a second sequence defined by successive lateral distances between adjacent valleys from the first side face to the second side face is a second non-periodic sequence, the first sequence being configured based on the second sequence, such that the valleys are arranged in a substantially coplanar formation and the peaks are arranged in a substantially non-coplanar formation.

15. The film of claim 14, wherein the valleys are substantially coplanar in that there exists a plane from which each respective valley is distant by no more than about 1.0 μ

m.

16. The film of claim 14, wherein the valleys are substantially coplanar in that there exists a plane from which each respective valley is distant by no more than about 0.5 μ

m.

17. The film of claim 14, wherein the valleys are substantially coplanar in that there exists a plane from which each respective valley is distant by no more than about 0.2 μ

m.

18. The film of claim 14, wherein the lateral distance between each pair of adjacent peaks having a first valley adjacent one side of the pair and a second valley adjacent the other side of the pair is half the lateral distance between the first and second valleys.

19. The film of any claim 14, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 1.2 or greater.

20. The film of claim 14, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 1.5 or greater.

21. The film of claim 14, wherein a ratio of the largest to the smallest lateral distance between adjacent peaks or adjacent valleys respectively is about 2.0 or greater.

22. An optical display assembly comprising:

a display panel;

a backlight assembly; and

a structured optical film according to any of the preceding claims 14, the film being located between the backlight assembly and the display panel.

23. The optical display assembly of claim 22, further comprising a second structured optical film, the second structured optical film being located between the backlight assembly and the first structured optical film and the second structured optical film having a structured optical surface comprising a plurality of elongate prisms, where the films are oriented such that the elongate elements of the second film are substantially crossed with respect to the elongate elements of the first film.

24. An optical display assembly comprising:

a display panel;

a light source; and

a structured optical film according to claim 14, the film being located between the light source and the display panel.

25. The film of claim 14, wherein the second non-periodic sequence is generated based on consecutive decimal digits of pi.

26. The film of claim 14, wherein each value in the first non-periodic sequence equals half the sum of an adjacent pair of valley distances.