Canon iR3245, Service Manual

Page: 214 / 746

Chapter 7
7-14
7.8.4 Toner Supply Control
0018-9719
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
Supply of Toner from the Toner Bottle to the Sub Hopper
If the "absence of toner inside the sub hopper" is detected while the main motor (M2/M22) is rotating, the toner bottle motor (M5) is rotated intermittently (on for
3 sec, off for 2 sec).
The length of time during which the absence is detected is counted using a soft counter that increases its count for each cycle of intermittent rotation.
When the count reaches 20 (approximately 100 sec), the machine assumes that the sub hopper has become empty, and displays the "Add Toner" message on its
control panel.
The counter is reset when the presence of toner inside the sub hopper is detected during any cycle of intermittent rotation.
Supply of Toner from the Sub Hopper to the Developing Assembly
If the "absence of toner inside the developing assembly" is detected while the main motor (M2/M22) is rotating and the developing clutch is on, the machine rotates
the hopper motor (M12) intermittently (on for 1 sec, off for 1 sec).
The length of time during which the absence is detected is counted using a soft counter that increases its count when the developing sensor (TS1) state is off during
a single cycle of intermittent rotation.
When the count reaches 20 (approximately 40 sec), the machine assumes that the developing assembly is more or less empty (i.e., there is a possibility of a blank
sheet of paper printed if printing continues), and issue a "No Toner" error (prohibition of image formation).
The counter is reset when the "presence of toner inside the developing assembly" is detected during intermittent rotation.
7.8.5 Recovery Sequence
0018-9720
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
The machine is not equipped with a mechanism to detect the replacement of its toner bottle, but is designed to execute toner recovery sequence in response to the
following, assuming that the toner bottle has been replaced:
- The front cover has been opened and closed after the machine has detected the absence of toner inside the toner bottle and the developing assembly.
- The machine has been turned off and then on after it has detected the absence of toner inside the toner bottle and the developing assembly.
The machine's recovery sequence is performed as follows:
1) The machine rotates the toner bottle motor (M5) intermittently (on for 3 sec, off for 2 sec).
2) When the sub hopper toner level sensor (TS2) detects the "presence of toner", the machine stops the recovery sequence.
3) When the sub hopper toner sensor does not detect the "presence of toner" after the foregoing intermittent rotation is repeated 20 times, the machine assumes that
the toner bottle has not been replaced and causes the toner bottle motor to stop.
7.8.6 Toner Level Detection
0018-9721
iR3225 / iR3225N / iR3235 / iR3235N / iR3245 / iR3245N
Detecting the Level of Toner in the Sub Hopper
The machine checks the level of the sub hopper toner sensor (TS2) every 100 msec, and assumes the presence of toner in the sub hopper if the sensor detects the
"presence of toner" twice or more continuously (200 msec or more).
If the machine detects the "absence of toner" 100 times or more continuously (10 sec or more) as the result of its check on the sensor level made every 100 msec,
the machine assumes that there is no toner in the sub hopper.
The machine executes the foregoing detection at all times regardless of the ON/OFF state of the main motor (M2/M22) and the developing cylinder clutch (CL3).
Detecting the Level of Toner in the Developing Assembly
1) The machine samples the output of the toner sensor (TS1) in the developing assembly every 100 msec (only if the developing clutch is on).
2) Considering 1.5 sec (15 times; continuous cumulative sampling when the clutch is on) as the unit of measurement, when the presence of toner is detected 3 times
or more, the machine assumes that there is toner in the developing assembly. When the presence of toner is detected two times or less on the other hand, the
machine assumes that there is no toner in the developing assembly.
However, in the case of iR3225/3230/3235/3245 series machines, the drive of the main motor is controlled to two different speeds.
Since stirring operation in the developing assembly is driven by the main motor, it is necessary to switch over the methods of detection.
Normal Speed Mode:
Considering 1.5 sec (25 times; continuous cumulative sampling when the clutch is on) as the unit of measurement, when the presence of toner is detected three
times or more, the machine assumes that there is toner in the developing assembly.
Low Speed Mode:
Considering 2.5 sec (42 times; continuous cumulative sampling when the clutch is on) as the unit of measurement, when the presence of toner is detected five
times or more, the machine assumes that there is toner in the developing assembly.
The machine converts the number of samplings and the number of times toner detection has been executed when switching over the methods of detection. The
conversion is based on proportional calculation of speed.
Detection of E020-0000
If the "absence of toner" is detected by the developing toner level sensor (TS1) and the "presence of toner" is detected by the sub hopper toner level sensor (TS2), the
route of supply from the sub hopper to the developing assembly may be clogged or the output of these toner sensors may be faulty. This error code (E020-0000) is
displayed when the soft counter reaches 194 (approximately 388 sec). The counter is designed to increase its count when the hopper sensor level is on during a single
cycle of intermittent rotation while toner is being supplied from the sub hopper to the developing assembly.
Detection of E025-0001
The toner bottle motor (M5) becomes unlocked when it rotates over the regular range. The machine detects whether or not the motor is locked for every 100msec
during operation of the toner bottle motor. Considering the occurrence of unlocked status at 15 times or more continuously (1.5 sec or more) as the unit of
measurement, when the unlocked status occurs for 12 units or more, the machine judges that a failure has occurred in the motor or in the drive mechanism and displays
the toner bottle motor error (E025-0001).