Patent ID: 9678264
Date: 2017-06-13
CPC Classifications: G02B

Claim:
1. A light guide plate, comprising: a light guide plate member comprising: a light incident surface on an end face of the light guide member, and a light emitting surface on a front surface of the light guide plate member, wherein the light incident surface is structured to have light incident thereon, and wherein the light emitting surface is structured to widen and emit light incident thereon out of the light guide plate member; and a directivity changing unit arranged on a light incident end portion of the light guide plate member on the front surface or a back surface of the light guide plate member, wherein the directivity changing unit comprises a first inner inclined surface and a second inner inclined surface that change a directivity of the incident light within the directivity changing unit to widen the light laterally with respect to a direction perpendicular to the light incident surface, wherein the directivity changing unit comprises a first outer inclined surface that has a first meeting line with the first inner inclined surface and a second outer inclined surface that has a second meeting line with the second inner inclined surface, wherein the first outer inclined surface changes the directivity of the light widened laterally by the first inner inclined surface to a directivity of light forming a smaller angle with respect to the direction perpendicular to the light incident surface, wherein the second outer inclined surface changes the directivity of the light widened laterally by the second inner inclined surface to a directivity of light forming a smaller angle with respect to the direction perpendicular to the light incident surface, wherein a distance between the first meeting line and the second meeting line becomes greater at positions farther away from the light emitting surface as viewed in a direction perpendicular to the front surface or the back surface of the light guide plate member, wherein the first inner inclined surface and the second inner inclined surface are inclined to be nearer the front surface or the back surface of the light guide plate member at positions nearer to a midpoint between the first inner inclined surface and the second inner inclined surface in a plane including the light incident surface, wherein the first outer inclined surface and the second outer inclined surface are inclined to be nearer to the front surface or the back surface of the light guide plate member at positions farther away from a midpoint between the first inner inclined surface and the second inner inclined surface in a plane including the light incident surface, and wherein a meeting line between the first inner inclined surface and the second inner inclined surface is inclined to be farther away from the front surface or the back surface of the light guide plate member at positions nearer to the light incident surface.