D-Phase Adjustment - Ricoh U-C1 B051 Service Manual

LASER UNIT

D-Phase Adjustment

This adjustment corrects the difference in density on the left and right sides of the
paper. The data sheet (distributed with the laser unit) is necessary for this
adjustment. After replacing the laser unit, do the following adjustment.
NOTE: 1) If the D-phase adjustment is not made, a difference in the density may
be seen. This difference can be conspicuous when the gray scale in the
Color Chart C-4 is copied or when an original is repeatedly copied.
2) The D-phase adjustment is necessary whenever a difference in the
density is seen. Keep the data sheet inside the front cover for future
use.
1. Print out the test pattern with SP5-
955-6 (☛ 5.1.3).
2. Check if horizontal black stripes can
be seen.
a) If stripes cannot be seen
(Figure 2), the D-phase
adjustment is not required.
b) If stripes can be seen (Figure
1), the D-phase adjustment is
required. Go on to the next
step.
3. See the value of "Mag. Shift Error:
LD1-2" below the bar code on the
data sheet, and find the range in
Table 1 which includes the value.
4. Find the corresponding values of
"Adjustment" in Table 1, and input
them in SP2-951-1 and SP2-951-2
respectively.
For example, when the value of
"Mag. Shift Error: LD1-2" on the
data sheet is "–4.0", enter "3" in
SP2-951-1 and enter "0" in SP2-
951-2.
5. Print out the test pattern with SP5-
955-6.
6. Check if vertical black stripes can
be seen.
Feed direction
Figure 1
Mag. Shift
Error: LD1-2
–11.8 ∼ –10.4
–10.3 ∼ –9.0
–8.9 ∼ –7.6
–7.5 ∼ –6.2
–6.1 ∼ –4.8
–4.7 ∼ –3.4
–3.3 ∼ –2.0
–1.9 ∼ –1.0
–0.9 ∼
1.0
1.1 ∼
2.0
2.1 ∼
3.4
3.5 ∼
4.8
4.9 ∼
6.2
6.3 ∼
7.6
7.7 ∼
9.0
9.1 ∼ 10.4
10.5 ∼ 11.8
3-16
26 July 2002
Figure 2
B051R902.WMF
Adjustment
SP2-951-1 SP2-951-2
8 0
7 0
6 0
5 0
4 0
3 0
2 0
1 0
0 0
0 1
0 2
0 3
0 4
0 5
0 6
0 7
0 8
Table 1