Optical film with partially coated structure array and manufacturing method thereof
The present invention relates to an optical film comprising a substrate on which an array of structures is formed, wherein a material having a different refractive index, absorbancy or reflectivity from that of a surface of the structures is partially coated on the surface of the structures, and a manufacturing method thereof. Specifically, the optical film according to one embodiment of the present invention may have a different transparency depending on the direction or can transmit light asymmetrically. Further, the optical film may be applicable to image devices, which need to change brightness or images depending on the angle of view or to display three-dimensional images.
1. An optical film for use on a display device or a light source for photolithography, comprising a substrate on which an array of structures is formed, wherein a material having a different refractive index, absorbency or reflectivity from that of a surface of the structures is partially coated on the surface of the structures, and a period, selected from a distance from a trough to a next trough and a distance from a crest to a next crest, of the array of structures provides a change in brightness, image, or light strength according to the viewing angle or the direction in which light passes through, or for representing a three-dimensional image.
2. The optical film according to claim 1 , wherein each of the structures is in a triangular prism form, the bottom of the triangular form is attached to the substrate, and the material is partially coated on the left and right sides, or the left or right sides of an upper surface of the triangular form.
3. The optical film according to claim 2 , wherein the material is coated on either one of the left or right sides.
4. The optical film according to claim 2 , wherein the material is coated on a portion of either one of the left or right sides.
5. The optical film according to claim 2 , wherein the material is coated on a portion of each of the left and right sides.
6. The optical film according to claim 1 , wherein the material is a metal.
7. The optical film according to claim 2 , wherein the material is coated on either one of the left or right sides, and the case in which the material is coated on the left sides and the case in which the material is coated on the right sides are periodically changed.
8. A method of manufacturing an optical film for use on a display device or a light source for photolithography, characterized in that the method comprises the steps of:
a) forming an array of structures on a substrate;
b) partially coating a surface of the structures with a material having a different refractive index, absorbancy or reflectivity from that of the surface of the structures,
wherein a period, selected from a distance from a trough to a next trough and a distance from a crest to a next crest, of the array of structures is selected to provide a change in brightness, image, or light strength according to the viewing angle or the direction in which light passes through, or for representing a three-dimensional image.
9. The method according to claim 8 , wherein the coating step comprises the step of using a mask blocking the coating of the material.
10. A display device equipped with an optical film according to claim 1 .
11. The device according to claim 10 , wherein the display device is a three-dimensional display device.
12. A directional light source device equipped with an optical film according to claim 1 .
13. A hologram equipped with an optical film according to claim 1 .