An surface light emitting device that is capable of emitting light of high luminance with higher uniformity is disclosed. The surface light emitting device comprising; a light guide plate, a reflector on the under surface of the light guide plate and, an LED light source having at least one LED element and provided so that a light emitted by the LED element is incident on at least one end face of the light guide plate, wherein the light guide plate has a light diffusing portion on the one end face so that a light emitted from the LED light source enters the light guide plate while being diffused therein, and the light diffusing portion has the top end being space from the top surface.
A prism member is interposed between an LED board and a light incidence surface of a light guide plate. The prism member includes a prism sheet consisting of minute prisms that are arranged along the LED board and that have a function of refracting light that is emitted from each LED and thereby inputting, to the light incidence surface, refracted light that is scattered to both sides in the longitudinal direction of the light incidence surface. As a result, chrominance or luminance unevenness can be prevented even if the distance between the LED board and the light incidence surface is short.
An optical waveguide plate for a surface light emitting apparatus and a surface light emitting apparatus using the optical waveguide plate that provides excellent uniformity in surface emission is disclosed. The optical waveguide plate comprises an end face introducing light emitted from a light source, and a light emitting surface outputting light introduced from the end face. The end face has a light introducing portion comprising a plurality of notched prisms which disperse incident light. The intervals between two adjacent prisms are set to become greater in proportion to the distance from the center of the light introducing portion. The angles of the prisms are also adjusted to provide uniform surface emission.
An optical waveguide plate for a surface light emitting apparatus and a surface light emitting apparatus using the optical waveguide plate that provides excellent uniformity in surface emission is disclosed. The optical waveguide plate comprises an end face introducing light emitted from a light source, and a light emitting surface outputting light introduced from the end face. The end face has a light introducing portion comprising a plurality of notched prisms which disperse incident light. The intervals between two adjacent prisms are set to become greater in proportion to the distance from the center of the light introducing portion. The angles of the prisms are also adjusted to provide uniform surface emission.
An illumination device is provided to solve locally high luminance near point-shaped light sources, while preventing overall decrease in luminance at the light-emitting face of a light guide member. The illumination device includes a light source for generating light, and a light guide member which receives light from the light source at a light input face and emits light from a light emitting face. A continuous optical pattern with prism faces and flat faces is provided on the light input face. Light emitted from the light source is diffused in the plane direction by the optical pattern, so there is no occurrence of locally-high-luminance areas near the LEDs in the light guide member. Moreover, the luminance of the light emitted in a planar manner from the light-emitting face does not decrease.
A plurality of light sources are provided at a front side of a lighting panel made of a transparent resin. The lighting panel has a light discharge side, and a reflection side opposite to the light discharge side. A plurality of refracting recesses are formed in the front side disposed to receive light emitted from the light source. The refracting recess has a sectional shape so as to cause the light to refract close to the front side in the lighting panel.
