Skew Correction - Ricoh B246 Series Manual

Skew Correction

Entrance Sensor
Roller
Feed
Roller
Interval
Sensor
Pre-scanning
Roller
Skew correction is done at the two circled locations.
Skew correction sensor/entrance roller: When the sensor detects the leading
edge of the original, the roller stops for a certain period. This buckles the
original and corrects the skew.
Interval sensor/pre-scanning roller: The actual method depends on the paper
size, and whether both sides will be scanned.
For single-sided scans larger than A5, the pre-scanning roller slows, while
the feed roller is still at the same speed. This is an attempt to keep the
copy speed as high as possible even for larger original sizes. If SP6020 is
changed from the default, the roller will stop (like for other job types), for
more precise skew correction. However, copy speed will be reduced.
For other types of job, the pre-scanning roller stops. All duplex scans are
stopped at this roller, for the best possible skew correction. This is
because both sides are scanned at the same time, by sensors on opposite
sides of the paper. Any skew in the ADF would therefore be noticeable on
the copy.
The rollers are driven by different motors, which makes it possible for one roller to
stop or be slower while the other one is still going.
Entrance roller: Driven by the feed motor
Feed roller (1st transport roller): Also driven by the feed motor
Pre-scanning roller: Driven by the transport motor
Note that the amount of buckle at each location can be adjusted with SP 6006.
6006 005: Corrects the amount of buckle at the entrance roller
6006 006: Corrects the amount of buckle at the pre-scanning roller
Skew Correction
112
Service manual, section 6.4.7
112