| 摘要 |
PURPOSE:To make it possible to perform highly accurate displacement measurement, by using a target whose brightness and darkness are inverted twice, and measuring the amount of the displacement or a position. CONSTITUTION:Light from a lamp 14 is made to be parallel light, which forms theta deg. with the surface of a body to be measured 16 by a collimator lens 15 and inputted to the target 17. The target 17 is arranged at a position so that the luminous flux is shielded by a sharp edge. The configuration of the target 17 is formed so that the brightness and darkness are inverted twice as shown in Figures (a) and (b). The light which has passed the target is converged by the lens 15, and an image is formed at a point P on the surface of the body 16. The light from the image P, which is reflected by the body 16, is inputted to an image forming lens 2. A virtual image P' of the image P is projected and formed on the detecting surface of a sensor 3. The signal from the sensor 3 is sent to a computer, where the position of the edge is computed. The result of the displacement measurement is displayed on a display device. |
