Xerox WORKCENTRE PE 220, Service Manual

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General Procedures and Information
6-16 11/05 Workcentre PE 220
• Parallel interface control.
• UART(2-Channel)
• Synchronous Serial Interface Control.
• A/D Converter(10-bit, 2channel).
• General I/O Port control.
• Tone Generator.
• RTC with calendar function.
• S/W Assistant function (Rotator)
- Flash Memory: Stores system program and can be updated to the newer system program
code through the PC interface. It stores the FAX Journal List, One Touch dial number, speed
dial number, and machine configuration setup data.
•
Capacity: 2 Mbyte
• Access Time: 70 nsec
- SDRAM: SDRAM is used for Print Buffer, Scan buffer when scanning, ECM Buffer when
FAX Receiving, and system working memory.
•
Capacity: 16 Mbyte
• Access Time: 66MHz based on system bus clock.
• Data Backup: 72 Hours
• Backup Battery Charging Time: 100hours when completely discharged.
Scanner
1) Image Signal Input
- Image Signal from CIS has a level of about 1.2V and is goes to ADC of Chorus2.
After ADC, CIS analog signal will be converted to 8-bit Digital signal.
2) Image Processing
- On the surface of the original paper, the light from the CIS LED reflected and goes to the
CIS Sensor.
Then the light is converted to the appropriate voltage suitable for ADC input. Analog signal
from CIS sensor is used for ADC input then is converted to 8-bit digital data. Image processor
of the Chorus2 will do the Shading correction function at first, then Gamma correction func-
tion next. After then, the data goes to different module according to the copy or FAX resolu-
tion mode. When Text mode, the image data goes to LAT module, when Photo mode, the
image data goes to Error Diffusion module, when PC-Scan mode, the image data goes
directly to the PC through DMA access.
•
Summary of the Image sensor interface is as below;
- Minimum Scan Line Time:1.5ms
- Scan Resolution: 600*600 dpi
- Scan Width: 208mm
- Function
• White Shading Correction
• Gamma Correction
• CIS Interface