User Guide

6.1.1 Block Diagram6.2 Scanner Cartridge Structure

1) LED

Red, green and blue LEDs are used to illuminate the scanning document. To

compensate for the low intensity of the red and green LED's, two red and green

LEDs have been incorporated and a total of five LEDs are mounted on the scanner.

Only the green LED is used for monochrome scanning.

2) Illumination lens

This "D" shaped lens converges the light from the LED light source.

3) Diffusion board

The light intensity of the LED is brighter at the center than at the ends. The

diffusion board allows even distribution of light onto the document.

4) Field lens

This lens prevents any magnification reduction caused by paper gaps when scanning

a lifted or bent document.

5) Imaging lens

This lens is used for forming an image of the light rays converged by the field lens

onto the CCD.

6) Shading board

The shading board with a slit at the front surface of the CCD is used to prevent

crosstalk generated in areas adjacent to high contrast areas.

7) CCD

The scanner cartridge uses a semiconductor type, one-line 128 pixel CCD (Charge

Coupled Device). Depending on the light amount of the image formed on the CCD,

electric voltage signals are sent to the scanner controller as image signals.

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BJC-2000

Part 4: Technical Reference

Scanning

Document

CCD

Mirror

Field Lens

LEDs

Platen

Slit

PCB

Imaging Lens

LEDs

Field Lens

Mirror

Illumination Lens

CCD

Diffusion Board

Imaging Lens

Figure 4-26 Scanner Cartridge