Ricoh A156 - Page 14

1.3 IMAGE DENSITY CONTROL ....................................................2-10
1.3.1 Overview.................................................................................................2-10
1.3.2 V
SP
and V
SG
Detection .........................................................................2-11
1.3.3 ID Correction for the V
SP
Pattern ...........................................................2-12
1.3.4 Toner Supply Control During Copying....................................................2-14
1.3.5 Toner Supply in Abnormal Sensor Conditions........................................2-16
1.4 DRUM POTENTIAL CONTROL.................................................2-18
1.4.1 V
R
Pattern Correction ...........................................................................2-18
1.4.2 V
L
Pattern Correction ...........................................................................2-20
1.4.3 T/H Correction ......................................................................................2-23
1.5 PROCESS CONTROL DURING ABNORMAL CONDITIONS ..2-25
1.6 SUMMARY.................................................................................2-26
1.6.1 Process Control and Sensor Detection Timing.......................................2-26
1.6.2 Process Control Checks During Machine Operation ..............................2-27
2. DRUM ............................................................................. 2-32
2.1 DRUM UNIT...............................................................................2-32
2.2 DRIVE MECHANISM ...............................................................2-33
3. DRUM CHARGE .............................................................. 2-34
3.1 OVERVIEW ..............................................................................2-34
3.2 DRUM CHARGE ROLLER DRIVE MECHANISM ..................2-35
3.3 DRUM CHARGE ROLLER CLEANING ....................................2-37
3.4 TEMPERATURE COMPENSATION .....................................2-38
4. OPTICS............................................................................. 2-39
4.1 OVERVIEW .............................................................................2-39
4.2 SCANNER DRIVE ...................................................................2-41
4.3 LENS DRIVE..............................................................................2-41
4.4 HORIZONTAL LENS POSITIONING .......................................2-43
4.4.1 Original Alignment Position ....................................................................2-43
4.4.2 Paper Size .............................................................................................2-43
4.4.3 Reproduction Ratio ................................................................................2-43
4.5 3RD SCANNER DRIVE ...........................................................2-45
Rev. 7/95
A156/A160/A162 ii STM