Sharp FO-3150 Service Manual page 94

FO-3150U/C
k. Top margin control
Top margin is set according to the number of lines (the number of HSYNC
interrupt) from detail paper Pin On to LASER input.
The interval between Pin On and point D is 52.6747 mm.
The interval between Point D and point B is: 27.33 (C-D) + 8.3769 (B-C)
= 35.7069 mm
If top margin is 4 mm,
52.6747 - 35.7069 + 4 = 20.9678 m
In case of the actual software processing, chattering of the sensor is
considered to be observed for 9 msec.
The processing speed is 50 mm/sec; while chattering is being observed,
paper is fed by 0.45 mm (9 x 50/1000 = 0.45 mm).
In order to gain top margin of 4 mm, printing data should be processed
after paper is fed by 20.5178 mm (20.9678 – 0.45 = 20.5178 mm) fol-
lowing PIN On detection.
The base machine resolution in the sub-scanning direction is 391.16
dpi; If the value 20.5178 mm is converted into the number of lines, 315.9
lines are obtained from 391.16 x 20.5178/25.4. Accordingly the soft-
ware set value is considered to be based on 316 lines.
Similarly, considering from the fact that resolution of PC printing is 600
dpi, the number of lines is 484.6 lines (600 x 20.5178/25.4=484.6).
The software set value is based on 485 lines.
Pout sensor
Paper exit roller
Discharge
9.3389mm(A-B)
brush
nip 5.7523mm
A
Fusing
30.3522mm(D-A)
Transfer
roller
ø13.4(13.7)
100.4mm(from Pin On)
123.8410mm(from Pin On until Pout On)
207.875mm(from Pin Off)
Process speed 50mm/sec
LASER
OPC drum speed 49mm/sec=(50x0.98)
8.3769mm(B-C)
B
C
OPC drum
nip 2.7693mm
Diameter ø24mm
27.33mm(C-D)
D
52.6747mm(from Pin On)
40.0697mm(from Pin Off)
Fig. 26
5 – 21
Pin sensor
Developing
roller
Paper feed
roller
37.2mm
(until Pin On)