| 摘要 |
1, 065, 270. Determining position photo - electrically. ERNST LEITZ G. m. b. H. June 29, 1965 [July 3, 1964], No. 27582/65. Heading G1A. In an arrangement for determining the position of a mark (10) Fig. 1 (not shown) on a transparent plate (1Oa) with respect to two co-ordinates, an image (16) of the mark is formed in a light beam by a plate (11), and the image is made to traverse a circular path by a rotating refractive element such as a prism or an oblique plate (12). The pulses produced in a photo-cell (17) by the recurring coincidences of the respective pairs of mark and image axes are fed to a flip-flop (18), and the leading and trailing edges of the output pulses from flip-flop (18) are fed to respective flip-flops (19), (20), which provide X and Y co-ordinate signals through integrating circuits (21), (22). The image and mark may both be cruciforms, or one may be a cruciform, and one a spot. |
