Front light module and front light guide plate of high-contrast structure

1. A front light module, comprising:

a reflective display device;

a light emitting unit configured to emit light; and

a front light guide plate located over the reflective display device and includes a micro-structure, and the micro-structure is recessed or convex, wherein a first angle is between a surface of the micro-structure close to the light emitting unit and an upper surface of the front light guide plate, a second angle is between a surface of the micro-structure away from the light emitting unit and the upper surface of the front light guide plate, and a third angle is between the surface of the micro-structure close to the light emitting unit and the surface of the micro-structure away from the light emitting unit, wherein the first angle is in a range between 30 degrees and 60 degrees, the second angle is in a range between 30 degrees and 59 degrees, and the third angle is greater than 90 degrees, wherein a footprint of the micro-structure on the upper surface of the front light guide plate has an asymmetrical and general dumbbell shape in a top view.

2. The front light module of claim 1 , further comprising a first adhesive layer between the front light guide plate and the reflective display device.

3. The front light module of claim 1 , further comprising a cover layer located over the front light guide plate.

4. The front light module of claim 1 , wherein the micro-structure has a depth and a length, and a ratio of the depth to the length is less than 0.3.

5. The front light module of claim 1 , wherein the micro-structure has a depth, a major axis length, and a minor axis length, and a ratio of the depth to the minor axis length or to the major axis length is less than 0.3.

6. The front light module of claim 1 , wherein the micro-structure is located on a side of the front light guide plate away from the reflective display device.

7. The front light module of claim 1 , wherein the micro-structure has a dimple in the top view.

8. The front light module of claim 3 , wherein the cover layer and the reflective display device are disposed on opposite sides of the front light guide plate.

9. The front light module of claim 3 , further comprising a second adhesive layer between the front light guide plate and the cover layer.

10. The front light module of claim 9 , wherein the second adhesive layer is rectangular and hollow in a top view.

11. A front light module, comprising:

a reflective display device;

a light emitting unit configured to emit light;

a front light guide plate located over the reflective display device and includes a micro-structure, and the micro-structure is recessed or convex, wherein a first angle is between a surface of the micro-structure close to the light emitting unit and an upper surface of the front light guide plate, a second angle is between a surface of the micro-structure away from the light emitting unit and the upper surface of the front light guide plate, and a third angle is between the surface of the micro-structure close to the light emitting unit and the surface of the micro-structure away from the light emitting unit, wherein the first angle is in a range between 30 degrees and 60 degrees, the second angle is in a range between 30 degrees and 59 degrees, and the third angle is greater than 90 degrees, wherein a footprint of the micro-structure on the upper surface of the front light guide plate has an asymmetrical and general dumbbell shape in a top view; and

a cover layer located over the front light guide plate.

12. The front light module of claim 11 , wherein the cover layer and the reflective display device are disposed on opposite sides of the front light guide plate.

13. The front light module of claim 11 , further comprising a first adhesive layer between the front light guide plate and the reflective display device.

14. The front light module of claim 11 , further comprising a second adhesive layer between the front light guide plate and the cover layer.

15. The front light module of claim 11 , wherein the micro-structure has a depth and a length, and a ratio of the depth to the length is less than 0.3.

16. The front light module of claim 11 , wherein the micro-structure has a depth, a major axis length, and a minor axis length, and a ratio of the depth to the minor axis length or to the major axis length is less than 0.3.

17. The front light module of claim 11 , wherein the micro-structure is located on a side of the front light guide plate away from the reflective display device.

18. The front light module of claim 14 , wherein the second adhesive layer is rectangular and hollow in a top view.

19. A front light guide plate of high-contrast structure, comprising:

a front light guide plate including a micro-structure, and the micro-structure is recessed or convex, wherein a first angle is between a surface of the micro-structure close to a light emitting unit and an upper surface of the front light guide plate, a second angle is between a surface of the micro-structure away from the light emitting unit and the upper surface of the front light guide plate, and a third angle is between the surface of the micro-structure close to the light emitting unit and the surface of the micro-structure away from the light emitting unit, wherein the first angle is in a range between 30 degrees and 60 degrees, the second angle is in a range between 30 degrees and 59 degrees, and the third angle is greater than 90 degrees, wherein a footprint of the micro-structure on the upper surface of the front light guide plate has an asymmetrical and general dumbbell shape in a top view.

20. The front light guide plate of claim 19 , wherein the micro-structure has a dimple in the top view.