1600/2000/2500 SCANNER
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December 2000 © TOSHIBA TEC
7.6 General Description of CCD control
7.6.1 Photo-voltaic conversion
The purpose of photo-voltaic conversion is to form electrical signals corresponding to the intensity of light
reflected from the original. A CCD (Charge Coupled Device) is used for photo-voltaic conversion. CCDs
are single-chip photo-voltaic conversion device in which several thousands of photosensing elements
several microns square are arranged in a single line. This copier uses a CCD having 7,450 of these
photosensing elements.
The photosensor comprises a P-layer, N-layer semiconductor. Optical energy generates a (-) (minus)
charge on the P-layer proportional to the optical energy and irradiation time. The charge generated at the
photosensor is transferred to the transfer area, shifted from right to left in the figure below according to the
transfer clock, and is output from the CCD. During this operation, the reaction speed of the CCD is slow (it
takes time for the charge to be transferred by the shift register), so even-numbered and odd-numbered
image signals are output in parallel.
1
2
3
4
7447 7448
7449 7450
Transfer area
Transfer area
Photosensor area
Transfer clock
Optical energy
Detailed photosensor
P-layer
N-layer
Transfer clock
Shift register
08-06-01
Principle of CCD Photo-Voltaic Conversion
Summary of Contents for DP1600
Page 1: ...DIGITALPLAINPAPERCOPIER DP1600 2000 2500 File No 31100011 R0111216600 TTEC ...
Page 2: ...Copyright 2000 TOSHIBA TEC CORPORATION ...
Page 232: ...1600 2000 2500 PCB BOARD 16 2 December 2000 TOSHIBA TEC 16 2 PWA F RLY 16 02 01 ...
Page 233: ...December 2000 TOSHIBA TEC 16 3 1600 2000 2500 PC BOARD 16 3 PWA F PIF 16 03 01 ...
Page 237: ...17 WIRE HARNESS CONNECTION DIAGRAMS 17 1 ...
Page 264: ...1 1 KANDA NISHIKI CHO CHIYODA KU TOKYO 101 8842 JAPAN ...