Ricoh J-P2 - Page 16

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2. TROUBLESHOOTING................................................................. 2-1
2.1 SCANNER TEST MODE .......................................................................... 2-1
2.1.1 VPU TEST MODE............................................................................ 2-1
SP4-907-1 VPU Test Pattern: R.......................................................... 2-1
SP4-907-2 VPU Test Pattern: G ......................................................... 2-1
SP4-907-3 VPU Test Pattern: B.......................................................... 2-1
2.1.2 IPU TEST MODE ............................................................................. 2-2
SP4-904-1 Register Write/Read Check Result.................................... 2-2
SP4-904-2 Image Path Check Result .................................................. 2-2
3. DETALED DESCRIPTIONS ........................................................ 3-1
3.1 SCANNING............................................................................................... 3-1
3.1.1 OVERVIEW...................................................................................... 3-1
3.1.2 SCANNER DRIVE ........................................................................... 3-2
3.1.3 ORIGINAL SIZE DETECTION ......................................................... 3-3
3.1.4 OTHERS.......................................................................................... 3-5
DC Power Supply................................................................................. 3-5
Anti-Condensation Heater.................................................................... 3-5
3.2 IMAGE PROCESSING ............................................................................. 3-6
3.2.1 OVERVIEW...................................................................................... 3-6
3.2.2 SBU BLOCK DIAGRAM................................................................... 3-7
Signal Processing ................................................................................ 3-7
A/D Conversion.................................................................................... 3-7
White Level Correction:........................................................................ 3-7
Others .................................................................................................. 3-7
Black Level Correction ......................................................................... 3-8
Adjustments ......................................................................................... 3-8
VPU Test Mode.................................................................................... 3-8
3.2.3 IPU BLOCK DIAGRAM .................................................................... 3-9
Shading Correction .............................................................................. 3-9
Picture Element (Dot Position) Correction.......................................... 3-10
Scan Line Correction.......................................................................... 3-10
Image Separation............................................................................... 3-10
Scanner Gamma Correction (RGB Gamma Correction) .................... 3-11
Filtering .............................................................................................. 3-12
ADS (Auto Image Density Selection) ................................................. 3-12
Color Conversion ............................................................................... 3-13
Main Scan Magnification .................................................................... 3-14
Printer Gamma Correction ................................................................. 3-15
Error Diffusion .................................................................................... 3-17
IPU Board Test................................................................................... 3-17
3.3 PRINTER ENGINE ................................................................................. 3-18
3.3.1 DIFFERENCES IN THE PRINTER MAINFRAME.......................... 3-18
3.3.2 PAPER FEED LINE SPEED .......................................................... 3-18
3.3.3 ENERGY SAVER MODES............................................................. 3-19
Overview ............................................................................................ 3-19
Panel Off Mode .................................................................................. 3-20
Auto Off Mode.................................................................................... 3-21