Prism sheet and display device using the same
AssigneeFUJIFILM Corporation
InventorKimitoshi Nagao
Life of this patent
Estimating the term…
Abstract
A prism sheet for emitting an incident light in an even distribution state of light quantity even in the case of using an irradiating light source such as a point light source having an emission of narrow band. A display device for deflecting and displaying the light from the light source evenly and efficiently without deteriorating the display quality by applying the prism sheet thereto. A prism sheet for deflecting and emitting a light introduced into a transparent substrate, with a prism formed on the substrate. The prism sheet includes: a circular prism having a plurality of annular grooves arrayed concentrically from a center axis; and a radial prism having a plurality of straight grooves arrayed radially from the center axis.
Claims1
A display device comprising:
- a light source;
- a prism sheet for deflecting and emitting light introduced into a transparent substrate, comprising:
- a transparent substrate;
- a circular prism formed on the transparent substrate, the circular prism having a plurality of annular grooves arrayed concentrically from a center axis;
- and
- a radial prism formed on the transparent substrate, the radial prism having a plurality of straight grooves arrayed radially from the center axis;
- wherein the center axis is aligned with an optical axis of the light source;
- an array of transmission type optical modulation elements arranged on a light emission side of the prism sheet for modulating light emitted from the prism sheet;
- and
- a reflecting member including a plurality of circular reflecting faces arrayed concentrically from a center line for reflecting light from the light source arranged on the center axis, on the circular reflecting faces thereby to introduce the reflected lights into the prism sheet;
- wherein the reflecting member is arranged on an opposite side of the prism sheet with respect to the light source;
- wherein the reflecting member includes inner annular slopes and outer annular slopes for forming a plurality of annular ridgelines concentrically from a center of a curvilinearly recessed substrate,
- wherein the inner annular slopes are formed to reflect the light emitted from the light source into substantially collimated lights, and
- wherein the outer annular slopes are formed substantially in parallel with an emission optical path from the light source.
Dependencies are inferred from the claim text.