Hitachi, Ltd.

Hiroshi Shirai

Akira Endo

Fumio Tsujii

Yoji Matsuoka

Takanori Shibata

Norio Minami

Isao Fukushima

Jiro Takezaki

Yoshimi Iso

Isao Akitake

Yoshitomo Kuwamoto

Osamu Numata

Shinichi Hagiya

A necessary signal portion of a control signal transmitted from a land station of a mobile telecommunication system during an idle period thereof is received intermittently by a mobile station, with an initial unstable operation period of the mobile station occurring in a period of an unnecessary signal portion of the control signal and a subsequent stable operation period thereof occurring in a period of the necessary signal portion of the control signal.

Control signal receiving system

A navigation system for displaying, on a display screen, road map information and running traces of a car superimposed thereon comprises a cathode ray tube for displaying the road map information and information regarding the car running traces and the like, bearing sensors for detecting a running direction of the car, a detector for detecting a running distance of the car by detecting a revolution of the car wheel, and a controller receiving outputs from the bearing sensors and the running distance detector, for computing a current position of the car and selecting road map information corresponding to the current position for display thereof on the cathode ray tube. The controller sets specified circular areas centered on respective crossings on the road map information, detects arrival of the car at an entrance to a specified area, determines an angular difference between an approaching running direction of the car and a destination bearing at the entrance, and gives, on the basis of the determined angular difference, a voice instruction for running of the car at the crossing to the driver.

Navigation system with capability of instructing running direction

In a navigation apparatus for automobile having a distance-travel detection sensor for detecting the distance traveled by a vehicle a direction detection sensor for detecting the direction of travel of the vehicle, data memory for holding map data and etc., a micro processing unit for calculating the present position of the vehicle from the signals of the distance-traveled detection sensor and the direction detection sensor and for outputting display signals for the present position of the vehicle and display signals for map data read out from the data memory to correspond to the present position of the vehicle and display means for display the display signals thereon, wherein the point, at which an update of the map data corresponding to the movement of the vehicle starts, is variable in accordance with the speed of the vehicle.

Navigation apparatus for automobile

In an FM receiver having an amplifier for amplifying an FM signal of intermediate frequency applied to an input terminal, and a phase multiplier type FM demodulator for demodulating the FM signal of intermediate frequency amplified by the amplifier, a noise muting circuit is disposed between the demodulator and the amplifier for muting noise transmitted from the amplifier to the demodulator when no FM signal input appears at the input terminal. This noise muting circuit comprises a pair of diodes connected in inverse-parallel with each other.

Noise muting circuit in FM receiver

Growing community of inventors

Katsuta, Japan

Hiroshi Shirai