| 摘要 |
<p>A position measuring instrument comprising photodetector means including linear arrays, each containing the same number of detector elements at regular intervals; and light source means for irradiating the photodetector means. The light source means includes variations, such as a single light source system, a multiple light source system, a minute difference system, an interference system and an in interference minute difference system. The outputs from the corresponding detector elements of the arrays are summed and the results are arranged at regular intervals to obtain a periodic function. The relative position between the photodetector means and the light source means in the actual space can be precisely determined by calculating the phase of this periodic function.</p> |
