| 摘要 |
PURPOSE:To surely obtain distance data without affecting by unstable brightness distribution, to surely enable focusing and to accurately and quickly measure a distance to the object even when the plural objects exist. CONSTITUTION:The object is caught by a light receiving sensor consisting of three line sensors 10b, 20b and 30b. The output signal value of the secondary difference of the brightness distribution is divided into three or more level areas. Then, a zero-cross point when a signal is changed to the level areas which are not adjacent and when such change occurs within the range of the prescribed number of picture elements of the light receiving sensor is calculated. Simultaneously, it is detected whether the zero-cross point is one when the secondary difference is changed to negative from positive or one when the secondary difference is changed to the positive from the negative. Then, the coincidence of three zero-cross behavior is detected while two zero-cross behavior among the zero-cross behavior related to three line sensors 10b, 20b and 30b is properly shifted with one line sensor among three line sensors as a reference. Based on the shift quantity of the zero-cross behavior of two line sensors when they coincide, the distance to the object is measured. |
