Abstract: A backlight source device including a transparent light guiding plate, a diffusing piece on the transparent light guiding plate, a reflecting piece below the transparent light guiding plate and a lateral light source. Diffusing units are installed on either a front surface or a rear surface of the transparent light guiding plate. The diffusing units have respective light guiding surfaces with different areas which are extendedly and continuously arranged. The light reflected on the diffusing units by the lateral light source becomes substantially uniform such that light and dark regions of a backlight source device can be avoided. The light guiding surfaces of the backlight source device can be formed such that different illuminations of emitted light are easily formed and illuminated.

Abstract: A backlight source device with circular arc diffusion units includes a transparent guide plate with circular arc diffusion units on the front or rear surface of the plate. A diffusion piece above the guide plate, a reflecting piece below the guide plate, and a lateral light source. Therefore, the dark and light regions in the backlight source device may be removed so that the illumination of the backlight becomes stronger and more uniform.