Canon PC720 Service Manual - Page 55

Operations

Get Canon PC720 PDF manuals and user guides View all Canon PC720 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 55 highlights

OPERATIONS AND TIMING= 2. Relationship between the Scanner Sensor and Signals Scanner sensor Scanner home position sensor (PS1) Signal SCHP Scanner Forward Reverse Description Reference used to determine the forward 5 travel distance. The scanner stops traveling in reverse in 0.1 sec. Table 3-202 3. Basic Sequence of Scanner Operations Power switch Copy Start key ON ON STBY V INTR I SCFW SCRV I SCFW SCHV LSTR STBYc Scanner home position sensor (PS1) Registration sensor (Q751) Scanner Scanner lamp (FL1) 0 rz/• rem •mm wym Pre-heat reverse C) : detects scanner home position C) : detects lens home position Figure 3-206 NE= The microprocessor on the DC controller PCB controls the forward travel distance of the scanner with reference to the rising edge of the scanner home position signal. The forward travel distance varies depending on the length of copy paper* and the selected reproduction ratio in ENLARGE: if the ratio is less than 130%, the scanner is moved forward for A4 (297 mm); if the ratio is 130% or more, the scanner is moved for LTR (279 mm). *For a discussion of how the length of copy paper is checked, see p. 3-44. COPYRIGHT © 1994 CANON INC. CANON PC720174017501170REV.O AUG.1994 PRINTED IN JAPAN (MPRIME AU JAPAN) 3 - 15

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
  • 94
  • 95
  • 96
  • 97
  • 98
  • 99
  • 100
  • 101
  • 102
  • 103
  • 104
  • 105
  • 106
  • 107
  • 108
  • 109
  • 110
  • 111
  • 112
  • 113
  • 114
  • 115
  • 116
  • 117
  • 118
  • 119
  • 120
  • 121
  • 122
  • 123
  • 124
  • 125
  • 126
  • 127
  • 128
  • 129
  • 130
  • 131
  • 132
  • 133
  • 134
  • 135
  • 136
  • 137
  • 138
  • 139
  • 140
  • 141
  • 142
  • 143
  • 144
  • 145
  • 146
  • 147
  • 148
  • 149
  • 150
  • 151
  • 152
  • 153
  • 154
  • 155
  • 156
  • 157
  • 158
  • 159
  • 160
  • 161
  • 162
  • 163
  • 164
  • 165
  • 166
  • 167
  • 168
  • 169
  • 170
  • 171
  • 172
  • 173
  • 174
  • 175
  • 176
  • 177
  • 178
  • 179
  • 180
  • 181
  • 182
  • 183
  • 184
  • 185
  • 186
  • 187
  • 188
  • 189
  • 190
  • 191
  • 192
  • 193
  • 194
  • 195
  • 196
  • 197
  • 198
  • 199
  • 200
OPERATIONS
AND
TIMING=
2.
Relationship
between
the
Scanner
Sensor
and
Signals
Scanner
sensor
Signal
Scanner
Description
Forward
Reverse
Scanner
home
position
sensor
(PS1)
SCHP
5
Reference
used
to
determine
the
forward
travel
distance.
The
scanner
stops
traveling
in
reverse
in
0.1
sec.
Table
3-202
3.
Basic
Sequence
of
Scanner
Operations
Power
switch
Copy
Start
key
ON
ON
V
Scanner
home
position
sensor
(PS1)
Registration
sensor
(Q751)
STBY
INTR
I
SCFW
SCRV
I
SCFW
SCHV
LSTR
STBYc
Scanner
Scanner
lamp
(FL1)
0
rz/•
rem
•m
m
wym
Pre
-heat
NE=
reverse
C)
:
detects
scanner
home
position
C)
:
detects
lens
home
position
Figure
3-206
The
microprocessor
on
the
DC
controller
PCB
controls
the
forward
travel
distance
of
the
scanner
with
reference
to
the
rising
edge
of
the
scanner
home
position
signal.
The
forward
trav-
el
distance
varies
depending
on
the
length
of
copy
paper*
and
the
selected
reproduction
ratio
in
ENLARGE:
if
the
ratio
is
less
than
130%,
the
scanner
is
moved
forward
for
A4
(297
mm);
if
the
ratio
is
130%
or
more,
the
scanner
is
moved
for
LTR
(279
mm).
*For
a
discussion
of
how
the
length
of
copy
paper
is
checked,
see
p.
3-44.
COPYRIGHT
©
1994
CANON
INC.
CANON
PC720174017501170REV.O
AUG.1994
PRINTED
IN
JAPAN
(MPRIME
AU
JAPAN)
3
-
15