Depolarizing film having an optically anisotropic volumetric region
Directed to a film having a depolarizing function, in which anisotropic volumetric regions are dispersed in a translucent matrix. For the translucent matrix, a material capable of forming a film itself, a hard coating layer formed on a surface of the film or a layer of an adhesive can be employed. It is therefore possible to provide a film, having a depolarizing function, of a kind in which when the film of the present invention is mounted on a surface of a polarizing plate arranged on a surface of a liquid crystal display device or an organic electroluminescent display device, the polarized state of a display light emerging outwardly from a display screen is partially altered and, hence, even when polarizing eyeglasses are worn on, darkening of the displayed image can be prevented and, also, a considerable shading of the color tone of the image can be reduced.
1. A film having a depolarizing function, which comprises an optically anisotropic volumetric region dispersed in a translucent matrix which is optically isotropic in a plane, that region being liquid crystalline polymer generated from methacrylic ester polymer, wherein a layer of an adhesive formed by the translucent matrix is provided on at least one surface of a translucent base film which is optically isotropic in a plane.
2. The film having the depolarizing function as claimed in claim 1 , in which a hard coat layer formed by the translucent matrix is provided on at least one surface of the translucent base film.
3. A film having a depolarizing function, which comprises, in a process of manufacture of the film as defined in claim 2 , a step of irradiating with a linearly polarized light.
4. A polarizing plate useable as a protective film, which comprises the film having a depolarizing function as defined in claim 2 .
5. A polarizing plate laminated with the film having a depolarizing function as defined in claim 2 .
6. The film as claimed in claim 1 , in which the anisotropic volumetric region has an average particle size not greater than 50 micron.
7. The film as claimed in claim 1 , in which the anisotropic volumetric region comprises a photo-alignment material.
8. A film having a depolarizing function, which comprises, in a process of manufacture of the film as defined in claim 1 , a step of irradiating with a linearly polarized light.
9. The film as claimed in claim 1 , in which the anisotropic volumetric region has an optical axis oriented in a constant direction.
10. A polarizing plate useable as a protective film, which comprises the film having a depolarizing function as defined in claim 1 .
11. A polarizing plate laminated with the film having a depolarizing function as defined in claim 1 .
12. A film having a depolarizing function, which further comprises, in a process of manufacture of the film as defined in claim 8 , a step of heating and cooling the film in addition to the irradiation of the linearly polarized light.
13. A film having a depolarizing function, which further comprises, in a process of manufacture of the film as defined in claim 3 , a step of heating and cooling the film in addition to the irradiation of the linearly polarized light.