| 摘要 |
PURPOSE:To correct the displacement of a light receiving element caused by a temperature variation, so that exact distance measured data can always be obtained even if a temperature is varied. CONSTITUTION:Infrared rays are projected to an object 4 to be photographed through a lens from a light projecting element 2, and its reflected light is received by a light receiving element 6 through a lens 5. The light receiving element 6 is fixed to a fitting plate 7, and displaced by a fitting plate displacing means 8. To the fitting plate displacing means 8, a voltage is supplied from its driving circuit 10. To a control circuit 12, temperature information is provided in a temperature measuring instrument 15, and data for deriving a driving voltage of the fitting plate displacing means 8 required for negating the displacement of the fitting plate 7 caused by a temperature variation is stored in a storage device 16. Before measuring a distance, a temperature is measured by the temperature measuring instrument 15, a temperature variation is derived by the control circuit 12 and a driving voltage corresponding to this temperature variation is read out of the storage device 16, the fitting plate displacing means 8 is driven through the driving circuit 10, and the light receiving element 6 is displaced to a correct position in which a temperature varied portion is corrected. Thereafter, the distance measuring operation is executed, and a focusing operation is executed. |
