Original Size Detection - Ricoh U-C1 B051 Service Manual

26 July 2002

6.5.3 ORIGINAL SIZE DETECTION

[A]
The original width sensors [A] detect the original width, and the original length
sensors [B] detect the original length.
The on/off signals received from the sensors are used to detect the original size.
The SBU board checks each sensor signal at the following times:
• Just after the platen cover is closed
• When the start key is pushed, if the platen cover stays open.
When the by-pass tray is used, the machine assumes that the paper is set
lengthwise. So, if A4 paper is set sideways on the by-pass tray, the machine
assumes it is A3 paper (set lengthwise) and scans the whole A3 area, disregarding
the original size sensors. However, when the registration sensor detects that the
paper is not A3 but only A4 sideways, paper feed stops and a jam occurs. This is to
prevent large amounts of toner transferring from the transfer belt to the transfer
roller. (Also see SP 1-940.)
NOTE: Original size detection using the ARDF is described in the manual for the
ARDF.
The table (next page) shows the sizes that are detected for various sensor outputs.
B051D004.WMF
6-21
SCANNING
[B]