| 摘要 |
PROBLEM TO BE SOLVED: To to enhance the measurement accuracy of distance without reducing the measuring range by synchronizing the sensitivity modulation of a plurality of two-dimensional image pickup elements with the brightness modulation of a plurality of light sources having different wavelength and modulation frequency and then measuring the two-dimensional distance of an object simultaneously. SOLUTION: Based on control signalsΦLD1 ,ΦLD2 from a control signal generation circuit 8, a light source drive section. 10 performs brightness modulation of two light sources 11a, 11b having different modulation frequency and, at the same time, a sensitivity modulation drive section 6 performs sensitivity modulation of two-dimensional image pickup elements 4, 5 at a same frequency by control signalsΦSM1 ,ΦSM2 . An object 13 located at a distance Z is then projected with light from two light sources 11a, 11b and the reflected light thereof is split through a half mirror 1. Subsequently, they are selected by means of optical bandpass filters 2, 3 and focused on image pickup elements 4, 5 thus accumulating the image information (signal charge). The distance Z to the object 13 is grasped roughly based on a signal charge ratio measured through a power supply 11a having lower modulation frequency, for example, and then it is determined precisely based on a signal charge ratio measured through the power supply 11b having higher modulation frequency.
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