The scanner assembly has three motors and three fans. The motors are stepping motors, which drive the components inside the scanner assembly. The fans cool various motors and components in the system.
Name | Purpose | Type | Rotation | Failure detection |
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Scanner motor (flatbed | Drives the scanner | Stepping motor | Varies | No |
motor) | carriage unit |
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Feed motor | Drives the pickup, the | Stepping motor | Varies | No |
| separation, and |
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| registration rollers |
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Read motor | Drives the feed and | Stepping motor | Varies | No |
| delivery rollers |
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Scanner base fan | Cools the power supply | Fan | Exhaust | No |
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Scanner motor fan | Cools the scanner lamp | Fan | Intake | Yes |
| and the CCD |
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ADF fan | Cools the feed motor | Fan | Exhaust | Yes |
| and the read motor |
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The optical assembly contains the lamp, five mirrors, a lens, and the charged coupled device (CCD).
Document
Scanning lamp | reflector | Fourth mirror | Third mirror | Glass |
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Inverter circuit
Fifth mirror
Lens | CCD |
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CPU
Scanner | First mirror | |
Second mirror | ||
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Controller |
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Figure
The scanner lamp illuminates a small strip of the document that is called the raster line. The mirrors direct the light through the lens to the CCD. The CCD senses and records the light, creating an analog representation of the raster line. If the ADF is being used, the document then advances in the ADF to the next raster line. If the flatbed is being used, the carriage advances to the next raster line. This advancing and collection process continues to the end of the sheet.
30 Chapter 4 Theory of operation | ENWW |