LCD optical guide plate with a roughened back surface having projections that support a reflecting sheet
AssigneeNEC Corporation
InventorShoichi Ueda
Life of this patent
Estimating the term…
Abstract
An optical guide plate serves as a surface illuminant in a liquid crystal display, and includes a transparent optical guide body shaped in a trapezoidal prism, a line light source radiating light toward the bottom surface serving as an incident surface and a reflecting sheet opposed to a granulated diffusion surface extending between the incident surface and a top surface and opposed to a light output surface, wherein micro projections are formed on the granulated diffusion surface so as to form an air layer between the granulated diffusion surface and the reflection sheet without any direct contact between the granulated diffusion surface and the reflection sheet, thereby permitting the incident light to be propagated through the air layer.
Claims22
An optical guide plate used in a liquid crystal display, comprising:
- an optical guide body formed of a transparent material, and including an incident surface, a granulated diffusion surface for scattering light components, a light output surface for radiating said light components therefrom and projections formed on said granulated diffusion surface, said projections having peaks with a height dimension of approximately 10 microns to 20 microns, which height dimension is greater than the dimensions of a granulation of the granulated diffusion surface;
- a reflecting sheet supported by said peaks of said projections so as to form an air layer between the reflecting sheet and the granulated diffusion surface;
- and
- a light source opposed to said incident surface for supplying said light components to said optical guide body.
A process for fabricating an optical guide plate, comprising the steps of:
- a) forming a transparent optical guide body having an incident surface, a granulated diffusion surface, a light output surface, and projections formed on said granulated diffusion surface, said projections having peaks with a height dimension of approximately 10 microns to 20 microns, which height dimension is greater than the dimensions of a granulation of the granulated diffusion surface;
- and
- b) assembling a reflecting sheet and a light source with said transparent optical guide body in such a manner that said reflecting sheet is supported by said peaks and that said light source is adjacent to said incident surface.
Dependencies are inferred from the claim text.