Original Scan Process; Main Scan Direction; Sub Scan Direction - Ricoh A193 Service Manual

4. ORIGINAL SCAN PROCESS

The machine scans at 400 dpi. The other end may have a different paper
size or may not be able to print at 400 dpi. The base copier's scanner and
BiCU work together to get the required resolution and size for transmission.

4.1 MAIN SCAN DIRECTION

The base copier's scanner always scans at 400 dpi (main scan direction).
Then, the BiCU processes the scanned data to get the required resolution
and data width. This is the same process as Reduction in copy mode.
Reduction
No reduction
A3 to B4
A3 to A4
B4 to A4

4.2 SUB SCAN DIRECTION

In the sub scan direction, the base machine's scanner changes the motor
speed to get the required resolution. However, if the reduction rate requires a
faster speed than the scanner motor's maximum (37% reduction rate when
using the ADF), the scanner and the BiCU (IPU) work together to get the
required resolution as shown in the second table below.
Reduction
No reduction
A3 to B4
A3 to A4
B4 to A4
lpi: lines per inch, lpm: lines per mm
Notes
Case 1 (35.2%)
Case 2 (25.0%)
Case 3 (21.6%)
Case 4 (17.6%)
Case 5 (20.4%)
Case 6 (34.5%)
Case 7 (24.5%)
Case 8 (21.2%)
Case 9 (17.3%)
Case 10 (19.9%)
(A639)
dpi: dots per inch, dpm: dots per mm
400 dpi
100.0%
86.5%
70.5%
81.5%
400 lpi 200 lpi 100 lpm
100.0% 50.0% 25.0%
86.5% 43.2% 21.6%
1
70.5% 35.2% 17.6%
81.5% 40.8% 20.4%
Mode Reduction by Scanner
52.8%
ADF 50.0%
Book 25.0%
43.2%
52.8%
40.8%
51.9%
ADF 48.9%
Book 36.8%
42.4%
51.9%
39.8%
2-9
ORIGINAL SCAN PROCESS
200 dpi 16 dpm
50.0% 101.5%
43.0% 88.0%
35.0% 71.5%
41.0% 83.0%
15.4 lpm 7.7 lpm
2
97.8% 48.9%
3
84.6% 42.3%
4
69.0% 34.5%
5
79.7% 39.8%
Reduction by BiCU
8 dpm
51.0%
44.0%
36.0%
41.5%
3.85 lpm
7
24.5%
8
21.2%
6 9
17.3%
10
19.9%
66.7%
50.0%
50.0%
33.3%
50.0%
66.7%
50.0%
66.7%
50.0%
33.3%
50.0%
SM