| 摘要 |
PURPOSE:To make it possible to shorten a range finding time by dispensing with the detection of a summed signal at every operation of range finding information, by providing an unchangeability detection means and a summed signal holding means to a signal processing means. CONSTITUTION:A computer 9 being a signal processing means, analogue switches 14, 15, an integration circuit 17 and a comparator 19 operate range finding information on the basis of the sum of two kinds of signals inputted from a light receiving means 5 and either one of said signals. An operational processing part 9b being an unchangeability detection means for detecting that the sum signal does not continuously changes and memories (d), (e) are provided to the signal processing means. Further, memories (a), (c) each being a summed signal holding means storing the sum signal detected as unchangeability and outputting the same at every operation of range finding operation are provided. By this mechanism, the detection of the summed signal, when the summed signal is continuously unchangeable, is not performed and, therefore, a range finding time can be shortened. |
