Hitachi, Ltd.

Hitachi Microcomputer Engineering, Ltd.

Hitachi Microcomputer System, Ltd.

Hitachi Video and Information System, Inc.

Makoto Goto

Kunio Seki

Hirotaka Mochizuki

Kenichi Onda

Yasuhiro Nunogawa

Soichiro Ogawa

Makoto Kobayashi

Kenji Kawabata

Motohiro Sugino

Ryuichi Ikeda

Susumu Iijima

An information processing apparatus employs a liquid crystal display and a fluorescent lamp for backlighting the screen of the liquid crystal display. A lighting circuit for supplying alternating current lighting power to the fluorescent lamp receives input power from either a commercial alternating current power source or from a direct current battery. The level of the lighting power supplied to the fluorescent lamp is determined based upon a determination of whether the input power is being supplied from the commercial power source or from the battery.

Information processing apparatus including a control circuit for

When a current that flows into a power output element is greater than a predetermined value, pulse width-modulated signals are formed which vary in inverse proportion to the current value in order to drive the power output element. When an excess current flows into the power output element, therefore, the power output element is allowed to intermittently operate for only short periods of time, and the current can be decreased during the current-limiting operation.

Power switching circuit

Growing community of inventors

Takasaki, Japan

Makoto Goto