Light deflection element and light source apparatus using the same
First Claim
1. A light deflector comprising a light entrance surface on which light is incident and a light exit surface located on an opposite side relative to said light entrance surface and allowing the incident light to exit therefrom, wherein said light entrance surface is formed with a plurality of elongated prisms arrayed substantially parallel to each other and each composed of two prism surfaces, at least one of said prism surfaces of each of the elongated prisms comprises at least three flat reflecting surfaces having mutually different inclination angles, and any one of said flat surfaces located on a side closer to said light exit surface has a larger inclination angle.
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Accused Products
Abstract
A surface light source apparatus includes a primary light source (1), an optical guide (3) for guiding light emitted from the primary light source and having a light incoming surface (31) and a light outgoing surface (32), a light deflection element (4) arranged adjacent to the light outgoing surface of the optical guide and having a light incoming surface (41) and a light outgoing surface (42), and a light diffusion element (6) arranged adjacent to the light outgoing surface of the light deflection element. The light incoming surface (41) of the light deflection element has a plurality of prism strings arranged substantially parallel to each other and each having two prism surfaces. At least one of the prism surfaces of these prism strings has a prism surface consisting of at least two planes having different inclination angles. As the plane approaches the light going surface, the inclination becomes larger.
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Citations
13 Claims
- 1. A light deflector comprising a light entrance surface on which light is incident and a light exit surface located on an opposite side relative to said light entrance surface and allowing the incident light to exit therefrom, wherein said light entrance surface is formed with a plurality of elongated prisms arrayed substantially parallel to each other and each composed of two prism surfaces, at least one of said prism surfaces of each of the elongated prisms comprises at least three flat reflecting surfaces having mutually different inclination angles, and any one of said flat surfaces located on a side closer to said light exit surface has a larger inclination angle.
- 2. A light deflector comprising a light entrance surface on which light is incident and a light exit surface located on an opposite side relative to said light entrance surface and allowing the incident light to exit therefrom, wherein said light entrance surface is formed with a plurality of elongated prisms arrayed substantially parallel to each other and each composed of two reflective prism surfaces, at least one of said reflective prism surfaces of each of the elongated prisms comprises at least two convex reflective curved surfaces having mutually different inclination angles, and any one of said convex curved reflective surfaces located on a side closer to said light exit surface has a larger inclination angle.
- 11. A light deflector comprising one surface serving as a light entrance surface and the other surface located on an opposite side relative to said one surface and serving as a light exit surface, wherein said light entrance surface is formed with a plurality of elongated prisms arrayed parallel to each other, each of said elongated prisms has two prism surfaces being a first prism surface and a second prism surface, and at least said second prism surfaces is formed as a substantially flat surface at one portion thereof located on a sideof a vertex portion of each of said elongated prisms while formed into a convex curved surface at the other portion thereof located on a side of said light exit surface, and wherein a ratio (h/H) of a height (h) from the vertex portion of each of said elongated prisms to a portion of the convex curved surface relative to a height (H) of each of said elongated prisms is 25 to 60%.
Specification