SURFACE-LIGHT-SOURCE ILLUMINATION DEVICE

摘要

The purpose of the present invention is to provide a surface-light-source illumination device that yields the requisite directional control for backlight applications and yields operation that is stabilized against vibration and significant temperature changes in the service environment. In this surface-light-source illumination device, linear light that is incident from a light source unit (2a) is caused to enter the end surface (1L) of a light guide plate (1) through a light entry part (3a) that has a light entry lens and a louver part; therefore, reliability can be kept high even under temperature changes and vibration in the service environment. Furthermore, in the light guide plate (1), the emission direction is set so that light reflected by a first light guide pattern (4A) provided on the rear surface is reflected by a second light guide pattern (4B) provided in the same manner on the rear surface; and the light is emitted with the desired distribution characteristics from the front surface of the light guide plate (1).