Ricoh DD 5450, Руководство по обслуживанию на месте, Страница: 164 / 403

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Chapter 3 Drum Section
Description
Usually, the ink roller is separated from the inner surface of the drum by a fixed clearance. During
printing, however, the press roller rises and presses the ink roller into contact with the drum inner
surface, so that ink is supplied via the drum inner surface to the printing paper. This mechanism
prevents ink from being supplied to the drum inner surface if the printer is run without any paper.
When the master is detached in the master making process, ink on the drum surface is removed
along with the document, which means that in the first printing after the master is attached, there is
a possibility of insufficient ink on the drum surface, resulting in faint images.
To prevent such ink sufficiency when in the first printing, the machine is equipped with a mechanism
raising and lowering the ink roller. Before paper is fed in, this mechanism pushes the ink roller
against the drum inner surface. As a result, the images on the first sheet printed after master
making are sufficiently bold.
Ink roller up and down movements are included as elements in the Fine Start mode, and therefore
are optimally controlled in accordance with room temperature, length of time out of use, number of
printed sheets in the last run, etc.
(2) Ink Roller Up/Down Mechanism
Circuit
2
1
1
2
1
2
3
4
11
23
12
24
15
14
13
1
1
2
3
4
CN6-22
-23
CN6-24
-25
+24V CN6-26
-27
-28
1
2
3
1
2
3
17
18
19
CN11-1
-2
-3
CN16-1
-40
CN15-1
-40
CN1-1
-40
CN9-1
-40
1
2
3
4
5
6
7
Ink pump motor
Ink detection PCB unit
Ink roller up/down motor
Ink roller up/down sensor
Drive PCB unit
Main PCB unit
Photopassing: 0V
Photointerrupting: 5V
No ink: 0V
Ink supplied: 5V
White
Brown
Green
Brown
Brown
Black
Blue
Blue
Purple
Red
7