| 摘要 |
PURPOSE:To reduce a change in distance measuring accuracy at the time of changing the distance of an object by finely moving an optical line sensor in its optical axis direction so that an image formation state on the optical line sensor is always in a high contrast state. CONSTITUTION:In a reference side optical system, a light beam passing an image forming lens 11A is reflected by a total reflection mirror 12A vertically to the optical axis and then reflected by a mirror prism 13 arranged between the mirror 12A and the optical line sensor 15 to form the image of an object on the sensor 15. A reference side optical system also similarly forms an object image on the line sensor 15 through an image forming lens 11B. Then distance measuring is started and the image of the object is projected to the line sensor 15. The line sensor 15 is finely moved in the optical axis direction to calculates the contrast in the image formation state. When the contrast is a maximum, the fine movement is stopped and phase difference operation is executed to calculate distance data. |
