2 - G - 6
DEVELOPING UNIT
[7] Gradation Correction Control
Gradation correction control is performed by the TCSB
(toner control sensor board), M2 (drum), M3
(developing), and so on. These parts are controlled
by the PRCB (printer control board).
1.
Operation
The gradation characteristics of the toner density
versus exposure amount at the image forming
section (drum area) are detected to obtain a linear
relation between the image density on a
document and the copying image density (toner
density).
(1) Method
Exposure is performed with the laser PWM varied
in several steps, and development is performed
at the toner transfer sleeve speed obtained by
Dmax correction.
Next, each density is read by
γ
sensor (PD2) on
the TCSB to detect the gradation characteristics
of image density.
The gradation characteristics obtained here are
used as the values for correcting the laser
exposure amount.
PRCB
DCPS2
DCPS1
DPSB
DPS
TCSB
24VDC
24VDC
PGND
12VDC
5VDC
SGND
M2 CONT
M2 F/R
SGND
M2 EM
M3 CONT
M3 CLK
M3 EM
DPS DRIVE A
DPS DRIVE B
DPS ANG 1
DPS ANG 2
DPS ANG
AGND
5VDC
MS2
MS1
M2
M3
/Dmax LED Vref
LED CONT
SIG/MONI
(2) Timing
a) When the fixing temperature is lower than 50°C
at power ON
b) At the end of job after every 20,000 copies.
2.
Signals
a.
PRCB Input signals
(1)
γ
SIG/MONI (TCSB to PRCB)
Output voltage from the
γ
sensor (PD2) on the
TCSB. This signal monitors the light reflected
by the drum surface (without toner).
The voltage applied to the gradation detection
LED is corrected by
γ
/Dmax LED Vref so that the
output voltage becomes 4.5V (calibration).
Reference voltage: 4.5V
<Timing>
Before gradation correction.
Содержание 7075/FORCE 75
Страница 1: ...FEBRUARY 2003 CSM 7075 F75 7085 F85 SERVICE MANUAL MODELS 7075 FORCE 75 7085 FORCE 85...
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Страница 3: ...7075 FORCE 75 7085 FORCE 85 SERVICE MANUAL FEBRUARY 2003...
Страница 39: ...OUTLINE 1...
Страница 40: ...Blank page...
Страница 55: ...1 15 MAIN BODY 11 Paper Exit Drive Section FRONT Paper exit roller Paper exit motor M10...
Страница 56: ...1 16 MAIN BODY 12 Toner Supply Drive Toner supply motor 1 M11 FRONT Toner supply motor 2 M15 Toner cartridge...
Страница 58: ...1 18 MAIN BODY 14 Web Drive Section FRONT Web drive motor M16 Cleaning web...
Страница 59: ...UNIT EXPLANATION 2...
Страница 60: ...Blank page...
Страница 62: ...2 A 2 EXTERNAL SECTION Blank page...
Страница 120: ...2 K 6 TRAY 3 PAPER FEED UNIT Blank page...
Страница 126: ...2 L 6 BY PASS TRAY Blank page...
Страница 130: ...2 M 4 VERTICAL PAPER CONVEYANCE SECTION Blank page...
Страница 154: ...2 O 8 FIXING UNIT Blank page...
Страница 165: ...DISASSEMBLY ASSEMBLY 3...
Страница 216: ...3 H 4 TONER SUPPLY UNIT Blank page...
Страница 224: ...3 I 8 CLEANING TONER RECYCLE UNIT Blank page...
Страница 232: ...3 J 8 PAPER FEED UNITS OF TRAYS 1 AND 2 Blank page...
Страница 240: ...3 K 8 TRAY 3 PAPER FEED UNIT Blank page...
Страница 292: ...3 O 18 FIXING UNIT Blank page 3 O 16...
Страница 293: ...MODELS 7075 FORCE 75 7085 FORCE 85 SERVICE SECTION FEBRUARY 2003...
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Страница 315: ...ADJUSTMENT 1...
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Страница 372: ...1 44 25 ADJUSTMENT 1 ADJUSTMENT Blank page...
Страница 458: ...1 114 OTHER ADJUSTMENT Blank page 1 112 2...
Страница 497: ...ISW 2...
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Страница 511: ...SERVICE 3...
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Страница 550: ...3 18 SERVICE Blank page...
Страница 551: ...ELECTRICAL PARTS LIST WIRING DIAGRAMS 4...
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Страница 610: ...4 40 Blank page METHOD ADDITION MODEL 7075 7085 MANUAL SERVICE HANDBOOK REVISED EDITION 3 DATE Jan 2002 PAGE 4 34 6...
Страница 611: ...JAM ERROR CODE LIST 5...
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Страница 625: ...5 13 JAM CODE LIST Blank page 5 11 2...
Страница 659: ...TIMING CHARTS 6...
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Страница 678: ...6 18 TIMING CHARTS Blank page...
Страница 679: ...INSTALLATION INSTRUCTIONS 7...
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Страница 833: ...APPENDIX 7085 OVERALL WIRING DIAGRAM...
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