Hitachi, Ltd.

Fumio Tsujii

Akira Endo

Takanori Shibata

Jiro Takezaki

Hiroshi Shirai

Yoji Matsuoka

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

A navigation apparatus mounted on a vehicle comprises a distance sensor sensing the travelled distance of the vehicle, a direction sensor sensing the advancing direction of the vehicle, an information storage unit storing map data, a signal processor computing the present position of the vehicle on the basis of the output signals from the distance sensor and direction sensor for displaying the computed present position of the vehicle on a color cathode-ray tube together with a map read out from the information storage unit. In the navigation apparatus, the map data are provided by position coordinate information or font information of division points dividing a road map into sections that can be linearly interpolated.

Navigation apparatus for automotive

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.

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Mito, Japan

Fumio Tsujii