Hitachi, Ltd.

Kokusai Electric Co., Ltd.

Isamu Mitomo

Tetsunori Kaji

Nobuo Tsukamoto

Hiroshi Noguchi

Kazuo Yamakido

Arata Nakagoshi

Jiroh Sakaguchi

Atushi Hoshi

A method of controlling the time constant of a filter for use in a radio receiver which receives a signal, transmitted from a transmitting station at a predetermined period, intermittently at the predetermined period and demodulates and delivers the received signal, a filter circuit having the time constant control function based on the method, and a radio receiver having the filter circuit. Preferably, the filter has its time constant switchable stepwise and specifically, parallel connection of capacitors or shortcircuiting of resistors is controlled by turning on/off switches. A controller within the filter circuit or the radio receiver performs control for applying a predetermined periodical signal (or standard pulse signal) to the filter and controlling the time constant of the filter in accordance with an output signal (or triangular pulse) during a first time zone within each operation interval for the intermittent reception and for filtering the signal from the transmitting station and causing a demodulating circuit to demodulate and deliver a filtered signal.

Method of controlling filter time constant and filter circuit having the

In a method of driving a display panel including liquid crystal cells arranged in the form of a matrix and displaying such display information as pictures, characters and numerals, which applies scanning pulse voltages to lateral electrodes of the display panel and applies to longitudinal electrodes of the display panel voltages of the pulse width modulation corresponding to the information to-be-displayed, thus to perform the line progressive scanning, a driving method in which voltages in an address period and in a nonaddress period as applied to the longitudinal electrodes are symmetric in magnitude to a voltage in the nonaddress period as applied to the lateral electrodes, and the difference between voltages in the address period and in the nonaddress period as applied to the lateral electrodes is at least double the difference between the voltages in the address period and in the nonaddress period as applied to the longitudinal electrodes.

Line progressive scanning method for liquid crystal display panel

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Hachioji, Japan

Isamu Mitomo