Sharp Kabushiki Kaisha Corporation

Kazuyoshi Izumi

Takashi Yoshii

Yutaka Inoue

Kohji Ohtsuka

Masayuki Eto

Fuyuki Kobayashi

Mamoru Kawagishi

Masahiro Oosawa

A backlight unit includes a fluorescent lamp to illuminate a liquid crystal panel, a reflection unit for causing the light from the fluorescent lamp to exit toward a certain direction, and a diffusion unit for diffusing the light from the fluorescent lamp and reflection unit, and reflectance or transmittance in the horizontal and vertical directions is controlled by applying a dot pattern that gradually increases densities from the central portion toward the peripheral portion to the reflection unit or diffusion unit, or by applying a dot pattern that gradually increases densities from the central portion toward the both ends in the longitudinal direction on the surface of the fluorescent tube of the fluorescent lamp. By doing this, brightness gradient is formed in the horizontal and vertical directions so that the brightness in the central portion of the liquid crystal panel is relatively higher than the brightness of the peripheral portion thereof.

Backlight unit and liquid crystal display device using the backlight unit

A backlight unit includes a fluorescent lamp to illuminate a liquid crystal panel, a reflection unit for causing the light from the fluorescent lamp to exit toward a certain direction, and a diffusion unit for diffusing the light from the fluorescent lamp and reflection unit, and reflectance or transmittance in the horizontal and vertical directions is controlled by applying a dot pattern that gradually increases densities from the central portion toward the peripheral portion to the reflection unit or diffusion unit, or by applying a dot pattern that gradually increased densities from the central portion toward the both ends in the longitudinal direction on the surface of the fluorescent tube of the fluorescent lamp. By doing this, brightness gradient is formed in the horizontal and vertical directions so that the brightness in the central portion of the liquid crystal panel is relatively higher than the brightness of the peripheral portion thereof.

This invention provides a RAM data selection circuit in which the screen data from the graphic display RAM and the text display RAM incorporated in the personal computer are simultaneously outputted and a data selection means adapted to output either of the two screen data preferentially by the dot unit to the monitor TV is provided, thereby rapidly enabling the superimposing of graphic and text data on the screen.

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Yaita, Japan

Kazuyoshi Izumi