Patent ID: 6036328
Filing Date: 2000-03-14
Classification: G02B,G09F,H01L,Y10S

Abstract:
A plane-shaped lighting device comprising:a light-directing plate made of a plate-shaped light-transmitting member; anda light source that is placed close to or in contact with one side face of the light-directing plate and provided outside the directing plate,wherein light, which has been emitted from the light source and made to be incident on a light-incident surface on the one side face of the light-directing plate, is thereafter emitted from a plane section of the light-directing plate, the light source being provided with LED lamps each LED lamp has an LED chip for emitting light and a semispherical lens that directs light from the LED chip to the inside of the light-directing plate, the LED lamp being designed so that the distance from the top of the semispherical lens to the LED chip is set to be not more than 1.8 times the radius of curvature of the semispherical lens.