| 摘要 |
<p>A radiation source (10) projects an optical pattern on the surface (17) of the workpiece (18) and the radiation (26) reflected by the surface (17, 22) is reproduced on a radiation receiver (30). Different distances (16, 19) result in different positions of the images (27, 28) of the reproduced surface (17, 22) on a perspective plane (25). The distances (16, 19) are derived from the position of the images (27, 28) by a signal processing device (32). This process is particularly suitable for measuring the depth of drilled holes. A desired depth can be preset with the help of an input means (33). The depth of the drilled hole is continuously measured during the work process and displayed on an optical output means. Once the desired depth is attained, an acoustic signal is given and the driving motor (37) is switched off.</p> |
