Backlight module and brightness enhancement film thereof

• US 7,411,732 B2
• Filed: 04/17/2007
• Issued: 08/12/2008
• Est. Priority Date: 03/16/2005
• Status: Active Grant

• Current Assignee: Optronic Sciences LLC
• Original Assignee: AU Optronics Corporation
• Inventors: Chen, Chih-Kuang, Kao, Ko-Chia, Huang, Jyh-Haur
• Primary Examiner(s): NGUYEN, THONG Q
• Application Number:
  US11/736,041
• Publication Number:
  US 20070188872A1
• Time in Patent Office: 483 Days
• Field of Search: 359/599, 359/707, 359831-837, 362/31, 362620-627
• US Class Current: 359/599
• 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 6/0068 Arrangements of plural sources, e.g. multi-colour light sources

Abstract

A backlight module includes a light source, a light guide disposed on one side of the light source, a reflector disposed under the light guide, a lower diffuser disposed on the light guide, and a brightness enhancement film, which is disposed on the lower diffuser and includes a main part and several prism structures disposed side by side on a main part plane of the main part. Each prism structure includes first to third triangular prisms. The second triangular prism is adjacent to one side of the first triangular prism, and an adjacent angle adjacent to a base angle of the first triangular prism is a right angle. The third triangular prism is adjacent to another side of the first triangular prism, and an adjacent angle adjacent to another base angle of the first triangular prism is a right angle.

Claims

1. A brightness enhancement structure, comprising:

an upper diffuser and a lower diffuser, for diffusing surface light;

a brightness enhancement film disposed between the upper diffuser and the lower diffuser, for enhancing the surface light passing through the lower diffuser, the brightness enhancement film comprising;

a main part having a main part plane; and

a plurality of prism structures successively disposed side by side on the main part plane, each of the prism structures comprising;

a first triangular prism;

a second triangular prism having a first right angle, adjacent to one side of the first triangular prism, the first right angle being adjacent to one base angle of the first triangular prism; and

a third triangular prism having a second right angle, adjacent to another side of the first triangular prism, the second right angle being adjacent to an other base angle of the first triangular prism, wherein the one base angle and the other base angle of the first triangular prism have different angular magnitudes;

wherein the first triangular prism, the second triangular prism, and the third triangular prism have different orientations and are disposed on the main part plane;

wherein the second triangular prism of one of the prism structures is adjacent to the third triangular prism of an adjacent one of the prism structures, and the second triangular prism of the one prism structure and the third triangular prism of the adjacent one prism structure have different orientations.

2. The brightness enhancement structure according to claim 1, wherein a top angle of the second triangular prism and a top angle of the third triangular prism are not the same.

3. The brightness enhancement structure according to claim 1, wherein a top angle of the second triangular prism and a top angle of the third triangular prism are acute angles.

4. The brightness enhancement structure according to claim 1, wherein a top angle of the first triangular prism is an acute angle.

5. A brightness enhancement structure, comprising:

an upper diffuser and a lower diffuser, for diffusing surface light;

a brightness enhancement film disposed between the upper diffuser and the lower diffuser, for enhancing the surface light passing through the lower diffuser, the brightness enhancement film comprising;

a main part having a main part plane; and

a plurality of prism structures successively disposed side by side on the main part plane, each of the prism structures comprising;

a first triangular prism having a first plane, a second plane and a third plane, wherein the third plane overlaps with the main part plane, the third plane has a long side substantially parallel to and equal to one side of the main part plane, the first plane and the second plane define a first angle, the first plane and the third plane define one base angle, the second plane and the third plane define an other base angle, and the one base angle and the other base angle of the first triangular prism have different angular magnitudes;

a second triangular prism having a fourth plane, a fifth plane and a sixth plane, wherein the sixth plane overlaps with the main part plane, the sixth plane has a long side overlapping with the long side of the third plane, the fourth plane is perpendicular to the main part plane, and the fourth plane and the fifth plane define a second angle; and

a third triangular prism having a seventh plane, an eighth plane and a ninth plane, wherein the ninth plane overlaps with the main part plane, the ninth plane has a long side overlapping with another long side of the third plane, the seventh plane is perpendicular to the main part plane and faces the fourth plane, and the seventh plane and the eighth plane define a third angle;

wherein the first triangular prism, the second triangular prism, and the third triangular prism have different orientations;

wherein the second triangular prism of one of the prism structures is adjacent to the third triangular prism of adjacent one of the prism structures, and the second triangular prism of the one prism structure and the third triangular prism of the adjacent one prism structure have different orientations.

6. The brightness enhancement structure according to claim 5, wherein the second angle and the third angle are not the same.

7. The brightness enhancement structure according to claim 5, wherein the first angle is an acute angle.

8. The brightness enhancement structure according to claim 7, wherein the first triangular prism is a scalene triangular pillar.

9. A backlight module, comprising:

a light source for generating light;

a light guide disposed on one side of the light source, for guiding and mixing the light generated by the light source and outputting surface light;

a reflector disposed under the light guide, for reflecting the light generated by the light source;

an upper diffuser and a lower diffuser, wherein the lower diffuser is disposed on the light guide, for diffusing the surface light outputted from the light guide; and

a brightness enhancement film disposed between the upper diffuser and the lower diffuser, for enhancing the surface light passing through the lower diffuser, the brightness enhancement film comprising;

a main part including a main part plane; and

a plurality of prism structures successively disposed side by side on the main part plane, each of the prism structures comprising;

a first triangular prism having a first plane, a second plane and a third plane, wherein the third plane overlaps with the main part plane, the third plane has a long side substantially parallel to and equal to one side of the main part plane, the first plane and the second plane define a first angle, the first plane and the third plane define one base angle, the second plane and the third plane define an other base angle, and the one base angle and the other base angle of the first triangular prism have different angular magnitudes;

a second triangular prism having a fourth plane, a fifth plane and a sixth plane, wherein the sixth plane overlaps with the main part plane, the sixth plane has a long side overlapping with the long side of the third plane, the fourth plane is perpendicular to the main part plane, and the fourth plane and the fifth plane define a second angle; and

a third triangular prism having a seventh plane, an eighth plane and a ninth plane, wherein the ninth plane overlaps with the main part plane, the ninth plane has a long side overlapping with another long side of the third plane, the seventh plane is perpendicular to the main part plane and faces the fourth plane, and the seventh plane and the eighth plane define a third angle;

wherein the first triangular prism, the second triangular prism, and the third triangular prism have different orientations and are disposed on the main part plane;

wherein the second triangular prism of one of the prism structures is adjacent to the third triangular prism of adjacent one of the prism structures, and the second triangular prism of the one prism structure and the third triangular prism of the adjacent one prism structure have different orientations.

10. The backlight module according to claim 9, wherein the second angle and the third angle are not the same.

11. The backlight module according to claim 9, wherein the first angle is an acute angle.

12. The backlight module according to claim 11, wherein the first triangular prism is a scalene triangular pillar.

13. The backlight module according to claim 9, further comprising a light source reflector disposed on another side of the light source.

14. A backlight module, comprising:

a light source for generating light;

a light guide disposed on one side of the light source, for guiding and mixing the light generated by the light source and outputting surface light;

a reflector disposed under the light guide, for reflecting the light generated by the light source;

an upper diffuser and a lower diffuser, wherein the lower diffuser is disposed on the light guide, for diffusing the surface light outputted from the light guide; and

a brightness enhancement film disposed between the upper diffuser and the lower diffuser, for enhancing the surface light passing through the lower diffuser, the brightness enhancement film comprising;

a main part including a main part plane; and

a plurality of prism structures successively disposed side by side on the main part plane, each of the prism structures comprising;

a first triangular prism;

a second triangular prism having a first right angle, adjacent to one side of the first triangular prism, the first right angle being adjacent to one base angle of the first triangular prism; and

a third triangular prism having a second right angle, adjacent to another side of the first triangular prism, the second right angle being adjacent to an other base angle of the first triangular prism, wherein the one base angle and the other base angle of the first triangular prism have different angular magnitudes;

wherein the first triangular prism, the second triangular prism, and the third triangular prism have different orientations and are disposed on the main part plane;

wherein the second triangular prism of one of the prism structures is adjacent to the third triangular prism of adjacent one of the prism structures, and the second triangular prism of the one prism structure and the third triangular prism of the adjacent one prism structure have different orientations.

15. The backlight module according to claim 14, wherein a top angle of the first triangular prism is an acute angle.