| 摘要 |
PURPOSE:To obtain a uniform brightness having a high contrast by placing an optical diffusion plate and a light control film between a light source for illuminating a transmission type liquid crystal display plate and the display plate, and irradiating a light of a good visual angle direction. CONSTITUTION:Three fluorescent lamps 2 are placed on the back of a twist nematic type liquid crystal display plate 1 of a time division driving, and an optical diffusion plate 4 is placed in front of the display plate 1. A light control film 5 and an optical diffusion plate 6 are placed between the display plate 1 and the fluorescent lamp 2. As for the light control film 5, its passing layer 5a and an absorbing layer 5b of a light are laminated by a smaller pitch than a pitch of a dot of a matrix, only a light between prescribed incident angles (phi1- phi2) is made to pass through, and its direction is made to coincide with a good visual angle direction. A light of the fluorescent lamp 2 is distributed uniformly by the diffusion plate 6, and only a light of a good visual angle direction in said light passes through the film 5, transmits through the display plate 1, and is diffused by the diffusion plate 4. In this way, a device which is thin and high in its contrast is formed. |
