Chapter 6
6-9
F-6-10
Bk is used to detect the reference BD signal and, as such, laser light is directed to the surface of the polygon mirror. In other words, the write start position in main
scanning direction for Bk is determined based on actual measurement and, for this reason, the possible presence of variation in the angle of the polygon mirror
surface will not lead to variation of Bk write start position.
The laser driver for C is found directly under the Bk laser driver and, for this reason, the C laser driver directs laser light against the same polygon mirror surface
as the Bk laser driver, eliminating the effects of variation in the angle of the polygon mirror surface. The write start position of C, for this reason, is also free of
variation as in the case of Bk.
6.2.2 Controlling the Intensity of Laser Light
6.2.2.1 APC Control
0013-9608
/ / / / iR C3380i / iR C3380 / iR C2880i / iR C2880
The machine uses APC control to make sure that the intensity of laser light remains at a specific level.
The machine uses 2 laser driver PCBs, each with a laser driver IC taking care of 2 colors and performing APC control for individual colors.
The following is an outline of APC control operation, executed each time the machine is turned on and for each print job:
1) The DC controller sends the laser control signal (LC_CTL_X(0)=0, LC_CTL_X(1)=1) to the laser driver IC on the laser driver PCB. (X differs depending on
the color.)
2) The laser driver IC is set to APC mode, thus forcing the laser diode (LD) to go on.
3) The laser driver IC monitors the laser diode (LD) by means of a photo diode (PD), adjusting the output of the laser diode until its light is a specific level of
intensity.
4) The laser driver IC stores the laser output in memory for use in the next print job.
Scanner motor constant
speed of rotation detection
START
BD interval
measurement
Write start correction
value computation
Write start
position correction
END
BD1
BD2
BD3
BD4
Short interval
Specific interval
Specific interval
Specific interval
BD1
BD2
BD3
BD4
BD1
T1
BD2
BD3
BD4
VDO
T1
VDO
T1
VDO
T1
VDO
Summary of Contents for iR C3380 series
Page 1: ...Aug 29 2006 Service Manual iR C3380 2880 Series...
Page 2: ......
Page 6: ......
Page 23: ...Chapter 1 Introduction...
Page 24: ......
Page 26: ......
Page 52: ......
Page 53: ...Chapter 2 Installation...
Page 54: ......
Page 127: ...Chapter 3 Basic Operation...
Page 128: ......
Page 130: ......
Page 136: ......
Page 137: ...Chapter 4 Main Controller...
Page 138: ......
Page 160: ......
Page 161: ...Chapter 5 Original Exposure System...
Page 162: ......
Page 188: ...Chapter 5 5 24 F 5 68 4 Remove the original sensor 2 hook 1 F 5 69...
Page 189: ...Chapter 6 Laser Exposure...
Page 190: ......
Page 192: ......
Page 206: ......
Page 207: ...Chapter 7 Image Formation...
Page 208: ......
Page 256: ......
Page 257: ...Chapter 8 Pickup Feeding System...
Page 258: ......
Page 262: ......
Page 303: ...Chapter 9 Fixing System...
Page 304: ......
Page 306: ......
Page 321: ...Chapter 10 Externals and Controls...
Page 322: ......
Page 326: ......
Page 336: ...Chapter 10 10 10 F 10 10 2 Remove the check mark from SNMP Status Enabled...
Page 337: ...Chapter 10 10 11 F 10 11...
Page 359: ...Chapter 11 MEAP...
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Page 362: ......
Page 401: ...Chapter 12 RDS...
Page 402: ......
Page 404: ......
Page 411: ...Chapter 13 Maintenance and Inspection...
Page 412: ......
Page 414: ......
Page 416: ...Chapter 13 13 2 F 13 1 8 9 1 2 3 3 5 6 7 10 11 12 13 14 4...
Page 421: ...Chapter 14 Standards and Adjustments...
Page 422: ......
Page 424: ......
Page 431: ...Chapter 15 Correcting Faulty Images...
Page 432: ......
Page 434: ......
Page 459: ...Chapter 16 Self Diagnosis...
Page 460: ......
Page 462: ......
Page 481: ...Chapter 17 Service Mode...
Page 482: ......
Page 484: ......
Page 571: ...Chapter 18 Upgrading...
Page 572: ......
Page 574: ......
Page 603: ...Chapter 19 Service Tools...
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Page 606: ......
Page 609: ...Aug 29 2006...
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