| 摘要 |
PURPOSE:To improve the detection sensitivity without increasing the size of the device by arranging the 2nd reflector at the other side of an observation lens, and reflecting light passed through the observation lens and forming its image at relatively close distance from the optical axis of the observation lens. CONSTITUTION:Two plane mirrors 8 are arranged at one side of one observation lens 5 in parallel to the optical axis and two plane mirrors 12 are arranged at the other side of the observation lens 5 in parallel to the optical axis. A light beam 13 is projected through the observation lens 5 of a body to be measured as to its shape, motion, and deformation to form a bright point T on the object body 3. Light from this bright point is reflected by the 1st reflector 8, and passed through the observation lens and reflected by the 2nd reflector 12 to form an image on an observation surface 9 eventually. Consequently, the size at right angles to the optical axis is reduced although the distance detection sensitivity is improved by using an enlargement optical system. |
