Epson PhotoPC 850Z, Руководство по обслуживанию, Страница: 44 / 127

EPSON PhotoPC 850Z Revision A
Operating Principles Operating Principles of Circuit Boards 44
Figure 2-7. IC904 Block Diagram
2.2.1.3 Lens Drive Block
Shutter Drive
The shutter drive signal (PCTRL) which is output from the ASIC expansion
port (IC108) is moved regular current drive for shutter, and the shutter
plunger is opened and closed.
The iris stepping motor drive signals (ACTRL1, ACTRL2, ACTRL3,
ACTRL4) which are output from the ASIC expansion port (IC108) are
driven by the motor driver (IC957), and the iris is moved six times.
Detection of the standard iris positions is carried out by means of the
photointerrupter (P12) inside the lens block.
Focus Drive
The focus stepping motor drive signals (LDIN1, LDIN2, LDIN3, LDIN4)
which are output from the ASIC expansion port (IC107) are driven by the
motor driver (IC954). Detection of the standard focusing positions is carried
out by means of the photo interrupter (PI) inside the lens block.
Zoom Drive
The zoom stepping motor drive signals (ZIN1, ZIN2, ZIN3, ZIN4) which are
output from the ASIC expansion port (IC107) are driven by the motor driver
(IC953). Detection of the standard zooming positions is carried out by
means of the photoreflectors (PR1, PR2) inside the lens block.
1
18
10
9
8
7
6
5
4
3
2
14
15
16
17
20
19
11
12
13
SHT
V3B
V
L
V3A
V
H
V1B
V1A
GND
V4
V2
XV2
V
DD
XSHT
XSG3B
XSG3A
XV1
XSG1B
XSG1A
XV4
Input
Buffer
XV3