Patent ID: 8970807
Filing Date: 2015-03-03
Classification: G02B,G02F

Abstract:
1. A backlight module, having light sources and a light guide plate, and the light guide plate has an incident side with a first refractive index, and the lights emitted by the light sources pass through a medium and the incident side and enter into the light guide plate, and the medium has a third refractive index, characterized in that: a distance between the light source and a light direction changing layer is a light coupling distance, and the light coupling distance is a predetermined distance for all the lights emitted by the light sources to enter into the light direction changing layer; the light direction changing layer is positioned at the incident side and is laminated to the incident side of the light guide plate, and the light direction changing layer has a second refractive index, and the second refractive index is smaller than the first refractive index and larger than the third refractive index; wherein the light direction changing layer is a transparent film, and material of the transparent film is silicon dioxide or calcium fluoride, and the light direction changing layer is employed for changing progress directions of the lights entering the incident side to shorten a distance perpendicular to the incident side from an intersection point of the lights emitted by adjacent light sources to the light sources.