Optical element and display device using the same
An optical element including a first pattern is provided. The first pattern includes 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 amplitudes.
1. 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, and the diffraction structure has two or more than two amplitudes.
2. The optical element according to claim 1 , wherein the diffraction structure further has two or more than two grating periods.
3. The optical element according to claim 1 , wherein the amplitudes progressively increase or progressively decrease towards two lateral sides from a central region of the diffraction structure.
4. The optical element according to claim 1 , wherein the amplitudes progressively increase or progressively decrease from one side towards another side of the diffraction structure.
5. The optical element according to claim 2 , wherein each ratio of the amplitudes to corresponding grating periods of the diffraction structure is constant.
6. The optical element according to claim 3 , wherein each ratio of the amplitudes to corresponding grating periods of the diffraction structure is constant.
7. The optical element according to claim 4 , wherein each ratio of the amplitudes to corresponding grating periods of the diffraction structure is constant.
8. The optical element according to claim 2 , wherein each ratio of the amplitudes to corresponding grating periods of the diffraction structure ranges from 0.1 to 10.
9. The optical element according to claim 2 , wherein each ratio of full widths at half maximum (FWHM) to corresponding grating periods of the diffraction structure ranges from 0.1 to 0.9.
10. The optical element according to claim 2 , wherein the diffraction structure comprises at least two grating groups, and a variation of the grating periods between two closest grating groups is equivalent to at least 1% of a largest grating period C or is smaller than 90% of the largest grating period C.
11. A display device, comprising:
a display; and
the optical element according to claim 1 disposed on a light output surface of the display.