Abstract: In a liquid crystal display device, a light quantity control portion b 4a is formed to a dot shape by print or the like on a diffusion plate 4 interposed between lens sheets 3 and a light transmission member 5 on the side thereof near to a backlight source 8 composed of a cold cathode fluorescent lamp or the like. Since the dots of the light quantity control portion 4a have a light transmitting property to a certain extent, they reflect a part of the light from the backlight source 8 and permit the remaining light to pass therethrough. With this arrangement, there can be provided the liquid crystal display device capable of brightly and uniformly irradiating the entire surface of the effective display area of a liquid crystal panel from the backside thereof without emission lines.

Abstract: The screen of a liquid crystal panel is divided into two portions. In the divided screens (upper screen and lower screen), the corresponding common electrodes (each for one divided screen) are simultaneously driven. The driving signal (common signal C1) of the upper screen and the driving signal (common signal C2) of the lower screen change in one cycle of four frame periods. More specifically, in the above-mentioned cycle, the common signal C1 changes in a pattern (1→1→1→−1), and the common signal C2 changes in a pattern (1→−1→1→1) in synchronization with each other. Accordingly, upon comparison of the common signals C1 and C2, it appears that the signal having the same waveform is applied to the common electrodes while being out of phase with each other. Thus, a difference of the drive frequency between the upper screen and the lower screen is eliminated.

Abstract: There is provided a small size and low price driving voltage generator (of a liquid crystal display unit) which can easily adjust output voltages. In this driving voltage generator, a DC-DC converter raises an input voltage (5 [V]) and produces voltages VH and VL. Resistors divide a voltage difference between the voltages VH and VL with resistors. Operational amplifiers output through current amplification each voltage divided by resistance. In the present invention, the external size can be reduced because only two output terminals are required for the DC-DC converter. In addition, manufacturing cost can be lowered because only two output terminals are required for the DC-DC converter. Moreover, since the resistors R1 to R6 are provided in the outside of the DC-DC converter (hybrid IC), these resistors can be exchanged easily. Therefore, the voltages V HCOM, V HSEG, V M, V LSEG, V LCOM can be adjusted easily.

Abstract: A liquid crystal display device contains a liquid crystal panel and a light transmission member disposed below the liquid crystal panel. A reflection sheet is disposed below the light transmission member and a light source is disposed adjacent to one end of the light transmission member. A reflector encases the light source. The periphery of the reflector has reflection walls and forms an opening continuous with the reflection walls. Light direction control walls are formed near the opening of the reflector to control the direction of the light from the light source. The light direction control walls cut off light directed in directions other than a predetermined set of directions. An inner surface of the light direction control walls is composed of reflection layers formed from a different material from the material that forms the reflection walls.