Ricoh LDD250, Service Manual

Page: 336 / 459

SCANNER AND OPTICS
C262/C265 6-14 SM
- Book mode -
In full size mode, the 1st scanner speed is 42.33 mm/s during scanning. The 2nd
scanner speed is half that of the 1st scanner.
In reduction or enlargement mode, the scanning speed depends on the
magnification ratio. The returning speed is always the same, in both full size and
magnification modes. Changing the scanner drive motor speed changes the image
length in the sub-scan direction. Image processing on the ECU board
accomplishes reduction and enlargement in the main scan direction.
SP6-1-5 changes the motor speed and therefore adjusts the magnification ratio in
the sub-scan direction.
- ADF mode -
During scanning, the scanners are always in their home positions (when the
scanner H.P sensor [H] detects the 1st scanner). The ADF motor feeds the original
through the ADF. In reduction/enlargement mode, changing the ADF motor speed
changes the image length in the sub-scan direction. Magnification in the main scan
direction is done on the ECU board, in the same manner as book mode.
SP6-1-6 changes the ADF motor speed and therefore adjusts the magnification
ratio in the sub-scan direction.
6.2.3 ORIGINAL SIZE DETECTION IN PLATEN MODE
The two width sensors [A] and four length sensors [B] are reflective photosensors.
These sensors detect the size of the original.
The size is detected at these times:
•
Immediately after the platen cover sensor [C] detects that the cover was just
closed
•
When the start key is pushed while the platen cover sensor is open.
C262D003.WMF
[B]
[A]
[C]