Alps Electric Co., Ltd.

Junichi Ohouchi

Kazuo Hasegawa

Hiroaki Sasaki

The coordinate detecting device according to this invention processes a plurality of detected adjoining input values scanned from an optical inputting grid and creates a single average value from the plurality which single value it provides to a host computer. It also evaluates data received from said optical inputting grid and restarts the scanning of the optical inputting grid independent of processing through a host computer when no input value is detected. It also receives and stores each input value received from said optical inputting grid, but does not provide an output to a host computer as long as an input value is detected, when an input value is no longer detected the last input value stored is outputted to a host computer. It also receives and stores each input values received from said optical inputting grid and compares each new value with the previous value which has been stored and when a difference between the new and the previous signals is detected the previous value stored is outputted to a host computer. It also receives and evaluates each input value received from said optical inputting grid and compares each new value with one or more valid value ranges previously stored and when an input value is in the valid range a range identifying signal corresponding to the range in which the valid signal is detected is outputted to a host computer, but when the evaluation shows that the value is not in a valid value range scanning is restarted and no signal is output to the host computer. Each of these functions relieves the amount of processing that the host computer is required to perform and thereby frees it for other tasks.

Coordinate detecting device

An optical position input device wherein an influence of disturbant light can be practically eliminated. The device includes a large number of light emitting elements and a large number of light receiving elements arranged in an opposing relationship along two sides and the other two sides, respectively, of directions of the X- and Y-axes. During driving scanning of the light emitting elements and the light receiving elements in the direction of the X-axis, a light reception signal developed in response to incident disturbant light from a selected one of the light receiving elements in the direction of the Y-axis is stored into a memory, and then the light reception signal is subsequently read out from the memory and is subtracted on a subtractor from a light reception signal developed from a light receiving element selected upon driving scanning for the direction of the Y-axis. The subtractor thus provides a position signal from which an influence of disturbant light has been eliminated assuredly. An influence of disturbant light is eliminated in a similar manner from a light reception signal developed from a light receiving element in the direction of the X-axis.

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Furukawa, Japan

Junichi Ohouchi