Anisotropic optical film
AssigneeTomoegawa Co., Ltd.
InventorMasahide Sugiyama
Life of this patent
Estimating the term…
Abstract
Provided is an anisotropic optical film which is capable of diffusing and condensing light in a wide incident angle range even when this film merely has a single anisotropic diffusion layer, which gives no unnatural impression, and which does not easily generate any light interference (rainbow). An anisotropic optical film having a diffusing property which varies in accordance with the incident angle of light radiated thereinto. The film has rectangularly columnar region, and a matrix region. At an incident angle of the light at which a maximum linear transmittance is exhibited, the maximum linear transmittance is 30% or more and less than 95%; and at an incident angle of the light at which a minimum linear transmittance is exhibited, the minimum linear transmittance is 20% or less.
Claims8
A single layer anisotropic optical film having two plain surfaces that are a top surface and a bottom surface, of which a diffusing property varies in accordance with an incident angle that is formed between an incident light, which is incident on the top surface, and a normal direction of the top surface, the film being composed with a plurality of rectangularly columnar regions that extends from the top surface to the bottom surface and a matrix region that surrounds the columnar regions, wherein
- the columnar regions and the matrix region are composed of an identical compound that is a photocurable compound, being formed by phase separation with a light irradiation, and having different absolute refractive indexes,
- surface shapes of each of the rectangularly columnar regions on the top surface and the bottom surface has have a short diameter (SA) and a long diameter (LA),
- the long diameter of the columnar regions ranges from 3.0 μm to 50 μm,
- the long diameter of the columnar regions is shorter than a width of the film, the width being determined in the same direction as the long diameter is oriented,
- aspect ratio (SA/LA), which is determined by the short diameter per the long diameter, ranges from 2 to 40,
- a thickness of the columnar regions, which is determined between the top surface and the bottom surface in a perpendicular direction to these top and bottom surfaces, is larger than the long diameter of the columnar region,
- the optical film is configured to have an optical profile, which illustrates a relationship of the linear a linear transmittance with respect to the incident angle, is created based on values of the linear transmittance that are observed when the incident angle varies from −75° to +75°,
- the optical profile having two peak regions and one valley region that intervenes between the peak regions, and
- the optical film is configured to have a maximum linear transmittance that is 30% or more and less than 95%, and the minimum linear transmittance that is 20% or less.
Dependencies are inferred from the claim text.