摘要 |
Disclosed is a method and an apparatus for detecting the leading edge of a sheet which is on the way to the scanning-and-reading station of an image read-out system. Detection is performed by exposing, just ahead of the scanning-and-reading station, the traveling sheet to the same scanning beam of light as used at the scanning-and-reading station, and by detecting the sudden change in the amount of reflection on arrival of the sheet at the station due to the difference between the reflection coefficients of the sheet and the underlying conveyer belt. Preferably, the scanning for detecting the leading edge of the sheet is at a higher frequency and smaller amplitude than the scanning for reading an image on the sheet.
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