Detecting the Size of Originals
Overview
The machine identifies the original size by the combination of measurement result of reflection light from the reflection sensor and specific points of CCD. Also to identify it accurately even though an original moves when ADF is closed, the machine measures 2 points for each size.
Main scanning direction: CCD (AB type: 12 points measurement, inch type: 6 points measurement)
Sub scanning direction: Reflection type photo sensor (AB type: 1 point, inch type: 1 point, AB/inch type: 2 point)
The followings are the procedures of original size identification.
1) External light search (main scanning direction only)
According to the LED status, the machine identifies the CCD level of each detection position in main scanning direction.
2) Output level detection of each sensor
The machine turns on the LED on CCD unit and measures the CCD level of each detection position in main scanning direction.
Also, turns on the LED on reflection type photo sensor in sub scanning direction and measures the sensor output.
The original size is identified by the combination of these output result.