*CCD unit
Images (light) is converted into an electrical signal (analog signal) by the CCD.
The image signal read by the CCD is converted into a digital signal b the A/D convertor in the MCU PWB and outputted to the ASIC, where the image is processed.
*Scanner motor
The scanner unit is driven by the scanner drive motor.
*Scanner home position sensor
The scanner home position sensor senses the scanner position. The copy image position control is performed by the sensing timing of this sensor.
*Zooming
Zooming is performed by changing the copy magnification ratio in the sub scanning direction or changing the scanning speed.
The copy magnification ratio in the main scanning direction is changed by the software in the ASIC.
C. Scanner (writing) section
(1) Outline
In this section, the dot image data sent from the MCU PWB are converted into laser beams (ON/OFF), which are scanned to form latent electrostatic images on the OPC drum. It is composed of the laser beam generating section (where dot image data signals are converted into laser beams (ON/OFF)), the laser beam correction section, the laser beam scanning section, and the laser beam detect- ing section. The major parts and their functions are described in the following.
(2) Block diagram
Scanning motor drive signal (PMD, PMCLK)
MCU | VIDEO | Laser diode | Laser | Collimator | No. 1 | |
cylinder | ||||||
(PCU) |
| control circuit | diode | lens | ||
| lens | |||||
|
|
|
|
| ||
SYNC | Laser beam | No. 2 | No. 1 | Motor | ||
reflection mirror | reflection | |||||
|
| sensor | mirror | |||
|
| (curved mirror) | mirror | |||
|
|
|
| |||
Drum
No. 2 cylinder lens
No. 3 reflection mirror
Signal
Laser beam
(3) Major parts
2)
1) SYNC
3)
8)
7)
4)
6)5)
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