Surface light source device, elements therefor and apparatus using the same
First Claim
1. A surface light source device comprising:
- a single light conducting plate having a light incident side surface which is perpendicular to an incident direction, a light emitting surface and an opposite surface which is opposite to said light emitting surface;
a light source disposed adjacent to said light incident side surface of said light conducting plate, at least one surface of said light conducting plate being shaped with a deflection pattern serving to deflect light from said light source inside said light conducting plate gradually toward a perpendicular direction to said light emitting surface and to diffuse light from said light source inside said light conducting plate more strongly in a transverse direction, which is parallel to both said light incident side surface and said light emitting surface, than in said incident direction; and
a converging pattern serving to cause emitted light from said light emitting surface to be converged in said transverse direction and to thereby improve directionality of said emitted light;
said deflection pattern being on at least either of said light emitting surface and said opposite surface, and said converging pattern being on at least either of said fight emitting surface and said opposite surface.
1 Assignment
0 Petitions
Accused Products
Abstract
A surface light source device has a light conducting plate with a light source disposed adjacent to one of its side surfaces. At least one pattern is formed on the upper light emitting surface of the light conducting plate and/or the lower surface. The pattern is provided such that the sum of average slope angles of the light emitting surface and the opposite surface on a first sectional surface which is perpendicular to both the light incident surface and the light emitting surface is greater than the sum of average slope angles of the light emitting surface and the opposite surface on a second sectional surface which is parallel to the light incident side surface. Image display apparatus incorporating such a surface light source device have improved brightness and other characteristics.
102 Citations
16 Claims
-
1. A surface light source device comprising:
-
a single light conducting plate having a light incident side surface which is perpendicular to an incident direction, a light emitting surface and an opposite surface which is opposite to said light emitting surface;
a light source disposed adjacent to said light incident side surface of said light conducting plate, at least one surface of said light conducting plate being shaped with a deflection pattern serving to deflect light from said light source inside said light conducting plate gradually toward a perpendicular direction to said light emitting surface and to diffuse light from said light source inside said light conducting plate more strongly in a transverse direction, which is parallel to both said light incident side surface and said light emitting surface, than in said incident direction; and
a converging pattern serving to cause emitted light from said light emitting surface to be converged in said transverse direction and to thereby improve directionality of said emitted light;
said deflection pattern being on at least either of said light emitting surface and said opposite surface, and said converging pattern being on at least either of said fight emitting surface and said opposite surface.
-
-
2. A surface light source device comprising:
-
a single light conducting plate having a light incident side surface which is perpendicular to x-direction, a light emitting surface and an opposite surface which is opposite to said light emitting surface yz-direction being parallel to said light emitting surface and perpendicular to said x-direction; and
a light source disposed adjacent to said light incident side surface of said light conducting plate;
at least either of said light emitting surface and said opposite surface being shaped with a deflection pattern consisting of sectional surfaces sum of average slope angles of said sectional surfaces in said x-direction, being greater than sum of average slope angles of said sectional surfaces in said y-direction. - View Dependent Claims (3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
-
Specification