摘要 |
An apparatus for measuring the distance between an extremum or object and the apparatus comprises a scanning system for scanning the entire distance range to be measured, the scanning system detecting objects at different distances from the apparatus within the range and producing in a time series an output which assumes an extremal value upon the detection, apparatus for producing a distance signal representing the scanned distance in a time series, a distance selecting device extraneously operable to select a desired distance range within the entire distance range to be measured, extremal value detecting apparatus for detecting the extremal value of the output of the scanning system corresponding to the selected distance range by the output of the distance selecting device, and apparatus for providing an output representing the distance between an object within the selected distance range and the apparatus from the output of the extremal value detecting apparatus and the distance signal. |