Ricoh B064 Service Manual page 617

Here is a summary of the skew correction methods.
Skew correction sensor/entrance roller
Duplex Scanning
Simplex Scanning
NOTE: Skew is always corrected with method
paper size and mode.
Interval sensor/pre-scanning roller stop correction
Duplex Scanning
Simplex Scanning
NOTE: Use SP6020 (ADF Contact Mode In/Out) to enable skew correction method
for all jobs to ensure accurate original feeding. However, switching this
feature on slows original feed slightly.
Interval sensor/pre-scanning roller slow-down correction
Duplex Scanning
Simplex Scanning
SM
ADF (B140 SERIES/B064 SERIES ONLY)
B6, A5, HLT Larger Than A5
Yes
Yes
for every job, regardless of the
B6, A5, HLT Larger Than A5
Yes
Yes
B6, A5, HLT Larger Than A5
No
No
6-19
Yes
Yes
Yes
No
No
Yes
B064 Series/B140 Series/G126