Film, backlight displays, and methods for making the same

• US 7,859,759 B2
• Filed: 06/18/2008
• Issued: 12/28/2010
• Est. Priority Date: 05/20/2002
• Status: Expired due to Fees

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: Sabic Innovative Plastics IP BV (Government of Saudi Arabia)
• Inventors: Yamada, Masako, Garg, Nitin, Miller, Scott Michael, Coyle, Dennis Joseph, Olczak, Eugene George
• Primary Examiner(s): Harrington; Alicia M
• Application Number:
  US12/141,674
• Publication Number:
  US 20090052045A1
• Time in Patent Office: 923 Days
• Field of Search: 359/619, 359/620, 359/625, 359/626, 359/454, 359/455, 359/459
• US Class Current: 359/625
• CPC Class Codes: G02B 5/045 Prism arrays
• CPC Class Codes: G02B 6/0053 Prismatic sheet or layer; Brightness enhancement element, sheet or layer
• CPC Class Codes: G02B 6/0061 to provide homogeneous light output intensity
• CPC Class Codes: G02F 1/133606 including a specially adapted diffusing, scattering or light controlling members
• CPC Class Codes: G02F 1/133607 the light controlling member including light directing or refracting elements, e.g. prisms or lenses
• CPC Class Codes: G02F 1/133611 including means for improving the brightness uniformity

Abstract

In one embodiment a film can comprises a surface comprising a plurality of prism structures. Each prism structure has a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures. The plurality of prism structures can have a variation in the w direction of prism peak height that is discrete and/or continuous. In one embodiment, a method for making a film can comprise forming a plurality of prism structures on a surface. The plurality of prism structures can have a lateral modulation in the w direction of less than or equal to ±20% of an average pitch of the prism structures, and wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous.

Claims

1. A film, comprising:

a surface comprising a plurality of prism structures, wherein each prism structure has a lateral modulation in a w direction of ±

2% to ±

20% of an average pitch of the prism structures;

wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous; and

wherein with a highest prism peak height is periodic at an interval measured in the w direction of greater than or equal to five times an average pitch, wherein the average pitch is determined over a sample length in the w direction of 100 mm, wherein the interval w direction is perpendicular to the l direction.

2. The film of claim 1, wherein a majority of prism peaks are greater than or equal to 0.5 micrometers below the highest prism peak height for any profile taken in the w direction.

3. The film of claim 2, wherein there is a cluster of peaks, as determined in the w direction, wherein the cluster contains less than or equal to 3 peaks and each cluster is separated by greater than or equal to 5 lower peaks being, and wherein the cluster is a group of adjacent peaks with a height within 0.25 micrometers of the highest prism peak height.

4. The film of claim 1, wherein there is a cluster of peaks, as determined in the w direction, wherein the cluster contains less than or equal to 3 peaks and each cluster is separated by greater than or equal to 5 peaks, and wherein the cluster is a group of adjacent peaks with a height within 0.25 micrometers of a highest prism peak height.

5. A film, comprising:

a surface comprising a plurality of prism structures, wherein each prism structure has a lateral modulation in a w direction of ±

2% to ±

20% of an average pitch of the prism structures;

wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous;

wherein the modulation is ±

2% to ±

15% of the average pitch wherein the average pitch is determined over a sample length in the w direction of 100 mm, wherein the interval w direction is perpendicular to the l direction.

6. The film of claim 5, wherein the modulation is ±

5% to ±

10% of the average pitch.

7. The film of claim 5, wherein prism structures have a height modulation in the 1 direction.

8. The film of claim 7, wherein the height modulation is random.

9. The film of claim 5, wherein the lateral modulation comprises a variable prism spacing.

10. The film of claim 5, wherein the lateral modulation is random.

11. The film of claim 5, wherein the variation is periodic and sinusoidal.

12. A backlight display comprising a light source and the film of claim 5.

13. A film, comprising:

a surface comprising a plurality of prism structures;

wherein each prism structure has a lateral modulation in the w direction of ±

2% to ±

15% of an average pitch of the prisms;

wherein the plurality of prism structures has a variation in the w direction of prism peak height that is discrete and/or continuous; and

wherein with a highest prism peak height is sinusoidal and periodic at an interval measured in the w direction of greater than or equal to five times an average pitch, wherein the average pitch is determined over a sample length in the w direction of 100 mm, wherein the interval w direction is perpendicular to the l direction.

14. A film, comprising:

a surface comprising a plurality of prism structures, wherein each prism structure has a lateral modulation in a w direction of ±

2% to ±

20% of an average pitch of the prism structures;

wherein the plurality of prism structures have a variation in the w direction of prism peak height that is discrete and/or continuous;

wherein there is a cluster of peaks, as determined in the w direction, wherein the cluster contains less than or equal to 3 peaks, and wherein the cluster is a group of adjacent peaks with a height within 0.25 micrometers of a highest prism peak height; and

wherein the cluster is separated by greater than or equal to 8 lower peaks.

15. The film of claim 14, wherein the average pitch is determined over a sample length in the w direction of 100 mm, wherein the interval w direction is perpendicular to the l direction.