BLUNT TIP PRISM FILM AND METHODS FOR MAKING THE SAME

• US 20090214828A1
• Filed: 02/26/2008
• Published: 08/27/2009
• Est. Priority Date: 02/26/2008
• Status: Abandoned Application

• Current Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Original Assignee: SABIC Global Technologies BV (Government of Saudi Arabia)
• Inventors: Watkins, Vicki Herzl, Miller, Scott Michael, Coyle, Dennis Joseph, Garg, Nitin, Olczak, Eugene George
• Application Number:
  US12/037,416
• Publication Number:
  US 20090214828A1
• Time in Patent Office: Days
• US Class Current: 428/156
• 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 6/0065 Manufacturing aspects; Material aspects
• 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 2201/50 Protective arrangements
• CPC Class Codes: Y10T 428/24479 including variation in thickness

Abstract

In one embodiment, a film can comprise a transparent substrate comprising a plurality of prism structures, wherein the prism structures have a blunt tip having a tip length of 250 nm to 2,000 nm. The film can be used in various applications, such as back light displays. In one embodiment, a method for forming a master for a film can comprise ion beam etching a diamond tip to form a blunt tip having a tip length of 250 nm to 2,000 nm, and forming negatives of prism structures into a master using the diamond tip.

Claims

1. A film, comprising:

a transparent substrate comprising a plurality of prism structures, wherein the prism structures have a blunt tip having a tip length of 250 nm to 2,000 nm.

2. The film of claim 1, wherein the tip length is 500 nm to 1,300 nm.

3. The film of claim 1, wherein the tip length is 500 nm to 1,000 nm.

4. The film of claim 1, wherein the tip length is 500 nm to 800 nm.

5. The film of claim 1, further comprising a relative abrasion damage of less than 50%, as compared to the same composition film with the same characteristic except without blunt prism tips, and determined in accordance with Equation 2.

6. The film of claim 5, further comprising a relative abrasion damage of less than 30%, as compared to the same composition film with the same characteristic except without blunt prism tips, and determined in accordance with Equation 2.

7. The film of claim 1, wherein prism has a virtual tip angle of the prism (Θ

) of 70°

to 120°

.

8. The film of claim 1, further comprising a luminance reduction of less than or equal to 3% as compared to a luminance of an equivalent film with sharp prism tips.

9. The film of claim 8, wherein the luminance reduction is less than or equal to 2%.

10. The film of claim 1, wherein the load required to create a visible scratch (as is determined with the unaided eye in a dark room, from a viewing distance of 0.1 to 1 meters), is increased by greater than or equal to 80%, as compared to the same composition film with the same characteristic except without blunt prism tips.

11. The film of claim 1, wherein each prism structure has a lateral modulation in the w direction.

12. The film of claim 11, wherein each prism structure has the lateral modulation in the w direction of ±

2% to ±

20% of an average pitch of the prism structures.

13. The film of claim 1, wherein the prism structures have a valley with a rounded radius of 100 nm to 1,000 nm.

15. A backlight display comprising a light source and the film of claim 1.

14. A film, comprising:

a transparent substrate comprising a plurality of prism structures, wherein the prism structures have a blunt tip having a tip length of 250 nm to 2,000 nm;

wherein the film has a relative abrasion damage of less than 30%, as compared to the same composition film with the same characteristic except without blunt prism tips, and determined in accordance with Equation 2; and

wherein a luminance of the film is reduced less than or equal to 5% as compared to a luminance of an equivalent film with sharp prism tips.

16. A method for forming a master for a film, comprising:

ion beam etching a diamond tip to form a blunt tip having a tip length of 250 nm to 2,000 nm; and

forming negatives of prism structures into a master using the diamond tip.

17. The master of claim 16, wherein each prism structure has a lateral modulation in the w direction.

18. The master of claim 17, wherein each prism structure has a lateral modulation in the w direction of ±

2% to ±

20% of an average pitch of the prism structures.

19. A method for forming prism structures into the surface of a transparent substrate, comprising:

contacting the master of claim 16 with a transparent substrate to form a light directing film having the prism structures with a blunt tip having a tip length of 250 nm to 2,000 nm.