Optical element and display device using the same
An optical element including a first pattern is provided. The first pattern includes a plurality of light deflection regions arranged along at least one set of first tracks in a first direction, and each first track is a waveform track having a first period T 1 and a first amplitude A 1 .
1. An optical element, comprising:
a first pattern, comprising:
a plurality of light deflection regions arranged along at least one set of first tracks in a first direction, wherein each first track is a waveform track having a first period T 1 and a first amplitude A 1 , wherein the light deflection regions have a characteristic dimension D, and T 1 , A 1 and D satisfy the following expressions:
A
1
≧
2
D
;
(
1
)
T
1
≧
2
D
;
and
(
2
)
0
<
A
1
T
1
≦
10.
(
3
)
2. The optical element according to claim 1 , wherein each first track is a sine function or a Fourier series represented as the sum of a plurality of sine functions.
3. The optical element according to claim 1 , wherein the light deflection regions are arranged along at least one set of second tracks in a second direction different from the first direction.
4. The optical element according to claim 3 , wherein each second track is a straight line.
5. The optical element according to claim 3 , wherein each second track is a waveform track having a second period T 2 and a second amplitude A 2 .
6. The optical element according to claim 5 , wherein each second track is a sine function or a Fourier series represented as the sum of a plurality of sine functions, and T 2 , A 2 and a characteristic dimension D of the light deflection regions satisfy the following expressions:
A
2
≧
2
D
;
(
1
)
T
2
≧
2
D
;
and
(
2
)
0
<
A
2
T
2
≦
1.
(
3
)
7. The optical element according to claim 6 , wherein
A
1
T
1
>
A
2
T
2
.
8. The optical element according to claim 3 , wherein the first tracks are arranged with a first pitch P 1 in the second direction, and 0.1D≤P 1 ≤25D; and the second tracks are arranged with a second pitch P 2 in the first direction, and 0.1D≤P 2 ≤25D.
9. The optical element according to claim 8 , wherein
0.1
≦
P
1
P
2
≦
10.
10. The optical element according to claim 1 , wherein each of the light deflection regions comprises a diffraction structure having two or more than two types of periods.
11. The optical element according to claim 1 , wherein each of the light deflection regions comprises a diffraction structure having two or more than two types of amplitudes.
12. The optical element according to claim 1 , wherein each of the light deflection regions comprises a diffraction structure arranged according to at least one of a gradient period and a gradient amplitude.
13. A display device, comprising:
a display; and
the optical element according to claim 1 disposed on a light output surface of the display.
14. An optical element, comprising:
a film; and
a plurality of light deflection regions arranged on the film, wherein each light deflection region comprises a diffraction structure having two or more than two types of periods, wherein the diffraction structure include at least two grating groups, and a variation of the grating period between two closest grating groups ranges from 5% to 100% of the variation ΔC, wherein the ΔC is a variation between a largest grating period and a smallest grating period of the diffraction structure.
15. The optical element according to claim 14 , wherein each of the light deflection regions comprises a diffraction structure having two or more than two types of amplitudes.
16. The optical element according to claim 14 , wherein each of the light deflection region comprises a diffraction structure arranged according to at least one of a gradient period and a gradient amplitude.
17. A display device, comprising:
a display; and
the optical element according to claim 14 disposed on a light output surface of the display.
18. An optical element, comprising:
a film; and
a plurality of light deflection regions arranged on the film, wherein each light deflection region comprises a diffraction structure having two or more than two types of periods, wherein the diffraction structure include at least two grating groups, and a variation of the grating period between two closest grating groups is equivalent to at least 1% of the largest grating period C or is smaller than 90% of the largest grating period C.