| 摘要 |
1,270,134. Digitizers. GERBER SCIENTIFIC INSTRUMENT CO. 6 Aug., 1969 [27 Jan., 1968], No. 39397/69. Heading G4H. [Also in Division G1] In a system for reducing the lines or edge of, e.g., a map or drawing to digital co-ordinate form, a reticle (20, Fig. 1, not shown) carried by a Y carriage 22 which is itself carried by an X carriage 24 is centred over a line or moved across an edge, the output signal from a photosensor (see Division G1) moved with the reticle then enabling the outputs of X and Y encoders carried with the X and Y carriages to be fed to a recorder 34 (Fig. 2). As described the output of the photo-detector when lines are being digitized is fed direct to a comparator 64 which when the photo-detector output exceeds a reference level primes a gate 84 so that the output from the X and Y encoders are fed to the recorder when minimum difference detectors 86, 88 indicate that a predetermined amount of movement in the X or Y direction has been exceeded. To digitize edge positions the photo-sensor output is connected via differentiator 68 and a negative pulse inverter to the comparator. The photo-sensors may include filters so that differently coloured lines may be separately digitized. |
