Canon ImageRunner iR8500 Series, Service Manual, Page: 271 / 1122

Chapter 5
5-19
T-5-14
5.3.3.7 Outline
0008-7405
/ iR8070
The system used to control the scanning lamp is constructed as follows and the items of control include the following:
[1] Turning on and off the scanning lamp.
[2] Monitoring the scanning lamp for errors.
F-5-28
5.3.3.8 Scanning Lamp
0008-7406
/ iR8070
The machine's scanning lamp is a xenon lamp of a non-electrode discharge type, in which xenon gas is sealed in a tube.
On the outside of the glass tube, two electrodes are arranged parallel to the tube axis, and the inner side of the glass tube is coated with fluorescent material.
The internal gas discharges and, as a result, the fluorescent material glows when a high-frequency voltage is applied across the electrodes.
F-5-29
5.3.3.9 Turning On/Off the Lamp
0008-7407
/ iR8070
The scanning lamp is turned on/off in response to the drive signal (LAMP_ON) from the CPU on the reader controller PCB. When the signal is generated,
the inverter generates a high-frequency, and high-voltage using the drive voltage (+24 V) supplied by the reader controller PCB to turn on the xenon tube.
5.3.3.10 Detecting an Error
0008-7408
/ iR8070
The reader controller circuit generates the error signal (INV_ERR) in response to an error
Related Error Code
E220
(activation error) [1] While in standby, the scanning lamp turns on. (detected in
reference to the voltage of FL-DTCT)
[2] During scanning, the scanning lamp turns off. (detected in
reference to the voltage of FL-DTCT)
E222
(fluorescent lamp heater error) [1] When the main power switch is turned on, the temperature does
not reach 70 deg C or higher 5 min after the scanner heater has
turned on (HEAT-ON=1).
[2] While power is supplied, the temperature does not reach 75 deg
C or more 3 min after the fluorescent lamp heater has turned on.
E211
(thermistor open circuit) [1] When the main power switch is turned on, the temperature does
not reach 10 deg C or higher 2 min after the fluorescent heater has
turned on (HEAT-ON=1).
[2] While power is supplied, a temperautre of 0 deg C or lower is
detected.
E215
(thermistor short circuit) While the scanning lamp is off, a temperature of 170 deg C or more
is detected.
E219
(scanning lamp end of life) While the scanning lamp is on, a temperature of 170 deg C or higher
is detected by the thermistor.
Inverter PCB
Xenon lamp
Activation
control
circuit
J5101 J5007
+24V
Reader controller
PCB
1
3
4
2
5
3
2
4
LAMP_ON
INV_ERR
LA101
CPU
Fluorescent
material
Electrode
Opening
Electrode
Electrode Electrode
Glass tube