| 摘要 |
<p>The photoelectric measurement appts. determines the posn of the edge of a sheet of paper on a rotary print machine surface, e.g. a feeder plate (1). It measures to an accuracy of 0.01 millimetres or better and produces a digitally evaluated measurement increment without needing an analogue to digital convertor. The flat ends (7) of a row of light conducting fibres (5) are directed at the edge of the paper via a hole (2) in the plate. The light (9) from a source (8) passes along unobscured fibres to individual fibre analysis units (10) producing corresp. electrical signals. The analyser signals can be fed to a counter or similar circuit. Two rows of fibres may be used at the measurement plane (7) in which case sensitivity can be doubled by staggering them by half a circular fibre end dia.</p> |
