Display optical films
View Patent ↗There is provided an optical film. The optical film comprises a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light. The optical film may be incorporated into a number of optical devices and structures.
1. An optical film comprising:
a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
2. The optical film of claim 1 , wherein the first surface structure function is one of a cylindrical lens microlens structure, a spherical lens microlens structure, an aspherical lens microlens structure, an elliptical lens microlens structure, and a parabolic lens microlens structure.
3. The optical film of claim 2 , wherein the first surface structure function is a cylindrical lens microlens structure.
4. The optical film of claim 2 , wherein the optical film includes a first plurality of elongated elements, each having a cross-section substantially corresponding to a cylindrical lens, the elongated elements being generally parallel in a first direction on at least the first surface of the film.
5. The optical film of claim 4 , wherein the optical film has a second surface opposite to the first surface, the second surface being smooth.
6. The optical film of claim 4 , wherein the film has a second surface opposite to the first surface, the second surface being defined by the first surface structure function modulated by the second surface structure function, wherein the second surface has a second plurality of elongated elements, each having a cross-section of a cylindrical lens, arranged on the second surface to be generally parallel in a second direction.
7. The optical film of claim 6 , wherein the first direction is generally parallel to the second direction.
8. The optical film of claim 6 , wherein the first direction is generally perpendicular to the second direction.
9. A prism film structure comprising:
a prism; and
a light diffusing film arranged over the prism film, the light diffusing film comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a micro lens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
10. The prism film structure of claim 9 , wherein the first surface structure function is one of a cylindrical lens microlens structure, a spherical lens microlens structure, an aspherical lens microlens structure, an elliptical lens microlens structure, and a parabolic lens microlens structure.
11. The prism film structure of claim 9 , wherein the prism film comprises a plurality of raised prismatic features.
12. An optical structure comprising:
a light source; and
a light diffusing film arranged over the light source, the light diffusing film comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
13. The optical structure of claim 12 , further comprising:
a prism film arranged between the light source and the light diffusing film.
14. The optical structure of claim 13 , wherein the prism film comprises a plurality of raised prismatic features.
15. A backlight display device comprising:
a light source for generating light;
a light guide for guiding the light therealong including a reflective surface for reflecting the light out of the light guide; and
a light diffusing film arranged on the light guide, the light diffusing film comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
16. An optical display device comprising:
a substrate comprising a source of light;
a modulation array comprising a plurality of modulation elements, including liquid crystal material, arranged to modulate light received from the source of light; and
a light diffusing film arranged adjacent the modulation array comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
17. The optical display device of claim 16 , wherein the modulation array comprises a polarizer arranged below the liquid crystal material, the light diffusing film arranged on the polarizer.
18. The optical display device of claim 16 , wherein the modulation array comprises a polarizer arranged above the liquid crystal material, the light diffusing film arranged on the polarizer.
19. A backlight display device comprising:
a light source for generating light;
a light guide for guiding the light therealong including a reflective surface for reflecting the light out of the light guide;
a prism film; and
a light diffusing film arranged above the prism film, the light diffusing film comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
20. A method of forming an optical film, comprising:
forming the optical film, the optical film comprising a first surface defined by a first surface structure function modulated by a second surface structure function such that the first surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
21. The method of claim 20 , wherein the forming the optical film comprises at least one of the techniques of photolithograpy, gray-scale lithography, microlithography, electrical discharge machining and micromachining using hard tools.
22. The optical film of claim 1 , wherein the first surface is defined by one of the following equations:
S 1 =A sin( x+R 1( x,y ))sin( y ),
S 2 =A sin( x )sin( y+R 1( x,y )), and
S 3 =A sin( x+R 1( x,y ))sin( y+R 2( x,y )),
wherein x and y are coordinates in the x-y plane of the film, R 1 (x,y) and R 2 (x,y) are random variables, and A is one of a constant and a random variable.
23. A prism film comprising:
a first surface comprising a plurality of raised prismatic features; and
a second surface opposing the first surface, the second surface defined by a first surface structure function modulated by a second surface structure function such that the second surface acts to diffuse light incident on the film, wherein the first surface structure function has a function of a microlens structure, and the second surface structure function has characteristics to provide the diffuse light, wherein the first surface has a correlation function value of less than about 37 percent in a correlation length of about 1 cm or less.
24. The prism film of claim 23 , wherein the first surface structure function is one of a cylindrical lens microlens structure, a spherical lens microlens structure, an aspherical lens microlens structure, an elliptical lens microlens structure, and a parabolic lens microlens structure.