Canon PC400 Service Manual - Page 51

Ii. Controlling The Scanning Lamp

Get Canon PC400 PDF manuals and user guides View all Canon PC400 manuals
Add to My Manuals
Save this manual to your list of manuals

Page 51 highlights

CHAPTER 3 EXPOSURE SYSTEM II. Controlling the Scanning Lamp A. Outline Figure 3-201A shows the circuit that controls the scanning lamp (fuse lamp), and the circuit has the following functions: • Turns the scanning lamp ON and OFF. • Controls the intensity of the scanning lamp. An intensity sensor (PD601) is provided to ensure that the original will be illuminated after the intensity of the scanning lamp has stabilized. The intensity of the scanning lamp is checked by the lamp intensity detection signal (LID) to make sure that the intensity has reached the specified value. In addition, a rush current protection circuit is provided to prevent rush current occurring when the lamp turns on. J621 -4 Scanning lamp (LA1-LA8) J108-1 +24VU - + Intensity sensor -3 (PD601) J108-2 (-1) Q143 Rush current protection circuit Lamp driver circuit Lamp ON signal (LAPWM) Microprocessor VR604 - + 5V Amplifier circuit J601 -10 (-5) J202 -13 Lamp intensity sensor signal (LID) Control panel PCB DC controller/DC power supply PCB The number within parentheses represents the PC400/FC200. FIgure 3-201A COPYRIGHT © 1998 CANON INC. CANON PC400/420/430,FC200/220 REV.0 JAN.1998 PRINTED IN JAPAN (IMPRIME AU JAPON) 3-7

  • 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
COPYRIGHT © 1998 CANON INC.
CANON PC400/420/430,FC200/220 REV.0 JAN.1998 PRINTED IN JAPAN (IMPRIME AU JAPON)
CHAPTER 3 EXPOSURE SYSTEM
3-7
II. Controlling the Scanning Lamp
A. Outline
Figure 3-201A shows the circuit that controls the scanning lamp (fuse lamp), and the
circuit has the following functions:
• Turns the scanning lamp ON and OFF.
• Controls the intensity of the scanning lamp.
An intensity sensor (PD601) is provided to ensure that the original will be illuminated
after the intensity of the scanning lamp has stabilized.
The intensity of the scanning lamp is checked by the lamp intensity detection signal
(LID) to make sure that the intensity has reached the specified value.
In addition, a rush current protection circuit is provided to prevent rush current
occurring when the lamp turns on.
FIgure 3-201A
Scanning lamp
(LA1-LA8)
J621
-4
-3
(-1)
+
-
+
-
Intensity sensor
(PD601)
VR604
5V
Control panel PCB
Amplifier circuit
J601
-10
(-5)
J108-2
+24VU
Q143
Lamp
driver
circuit
Rush current
protection circuit
Lamp ON
signal
(LAPWM)
Lamp intensity sensor signal (LID)
The number within parentheses represents the PC400/FC200.
J202
-13
DC controller/DC power supply PCB
Microprocessor
J108-1