| 摘要 |
<p>A positioning device is used for a record card which is to be subjected to a line scan. It operates by means of a pressurised medium operating a piston drive and the drive system is provided with a multi-stage set of pistons with binary coding in whole multiples of the line spacing. A coding signal corresponding to the line to be scanned is used to produce a relative lateral movement between the card carrier and the drive mechanism so that any desired line can be scanned and the appropriate binary code signal may be used for selective feed of the pressure medium to the appropriate piston cylinder.</p> |
