发明名称 SPACE FILTER FOR GROUND SPEED SENSOR
摘要 PURPOSE:To enable the highly precise detection of a ground speed at all times by method wherein sensitivity patterns of a plurality of light-detectors are varied symmetri cally from the central parts thereof to the longitudinal direction in relation to the direction of transfer of an image. CONSTITUTION:Light-receiving lattices 109 and 110 are so combined alternately as to be paired with each other and are arranged continuously, while they are so patterned that the light-receiving area of each of the them increases gradually in the longitudinal direction, becomes maximum in the center and then decreases gradually. By shaping a space filter 1 to be protuberant on both sides in this way the quantity of the light taken in the filter 1 increases gradually and then decreases gradually even when the direct-current intensity of a reflected light varies sharply with a sharp change in the circumstances of a road surface. Therefore a low-frequency component obtained through differential processing of signal of the filter 1 and superposed on an output of a differential amplifier becomes so small that it can be neglected. As the result, the missing of a central frequency component in a zero cross detector is eliminated, and thus an instantaneous state wherein a ground speed can be measured when the circumstances of the road surface changes sharply can be prevented from occurring.
申请公布号 JPS63233375(A) 申请公布日期 1988.09.29
申请号 JP19870064252 申请日期 1987.03.20
申请人 HITACHI LTD 发明人 SUZUKI KIYOMITSU;TSUCHIYA SHIGEKI;KAYANO MITSUO;MATSUMOTO MASAHIRO
分类号 G01P3/36;B60T8/66 主分类号 G01P3/36
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