Line Scanning Mechanism - Ricoh MP C2504 Field Service Manual

7. Detailed Descriptions

Line Scanning Mechanism

[A]: Dust shield glass
[B]: 1st mirror
[C]: F-theta lens
[D]: Polygon mirror motor
1. Mirror, lens
Laser diodes of each color emit light to match the paper transport timing. After passing through the
cylinder lens (laser beam width correction), polygon mirror motor (main scanning line scan), F-
theta lens (dot position correction and optical face tangle error correction), it reaches the drums of
each color.
The F-theta lens has a two-stage integrated construction, and 2 color beam correction is performed
with one lens.
2. Polygon mirror motor
The polygon mirror motor comprises two (upper and lower) 6-faced mirrors formed in an integral
construction (these are combined in one unit).
In this MFP, 4 color simultaneous write is performed by the LD irradiating a polygon mirror.
* The rotation speed of the polygon mirror motor is controlled by LD/ Polygon mirror motor.
3. Synchronization sensor
There are two synchronization sensors, i.e., one on the K-C side, and one on the M-Y side. Each
sensor detects light from one color, and synchronization for two colors is calculated from this.
There is only one sensor for each color. The sensor at the leading edge of the main scan line has
been removed.
4. Scan line inclination and automatic adjustment mechanism
The laser optics positioning motor installed on the 2nd mirror adjusts the scan line inclination.
This is done during automatic image position correction.
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