| 摘要 |
PURPOSE:To provide an inexpensive distance measuring device which is capable of discriminating the specified distance zones even with a miniature optical system of relatively low accuracy by providing a circuit which performs distance discrimination when a plurality of photo detectors received the reflected light image from the measuring target. CONSTITUTION:At the time of distance detection, a light source 8 emits light for a short time and radiates light to the object through a projection lens 9. The reflected image from the object is received in an image forming lens 10 and is formed on the photo detecting surface of the plural photo detectors 11 arrayed in array form. E.g., four pieces of photo detectors 11a thru 11d are arrayed to the photo detectors and are so arranged that the adjoining three photo detectors receive light simultaneously. A distance pattern 101 being comb-tooth form electrodes corresponding to the distance zones which the photo detectors receive light is printed on an electrode substrate 100 and is slided with contact piece 102 moving integrally with a photographing lens 1. The pulses from the respective photo detectors 11 are led to the logic circuits consisting of AND, NOT circuits, etc. and the signal indicating the zone of the measuring target is emitted through combination of each photo detector, by which the photographing lens 1 is stopped in the positin corresponding to that distance. |
