Sharp Z-87 Service Manual page 24

1) Mirrors (No.4/No.5) mirror unit
This unit is employed to control the optical distance by means of the
cam.
2) Lens
A through type fixed focus lens is used.
3) Blank lamp PWB
The blank lamp PWB consists of the side lamps (SL1, 2, 3, 4) and the
void lamp (VL).
In the reduce mode, light from the side lamp is exposed to the drum
to prevent toner from applied on the non-image area.
Light from the void lamp is exposed over the remover contact area on
the drum to discharge the area to prevent toner from applied on the
void area.
Magnification ratio SL1 SL2
0.95 OFF OFF OFF OFF
0.75 ON ON
2. Optical system drive
A. Drive operation in the optical system
In the optical system, the light source unit and the No. 2 and the No.
3 mirror unit are driven by the scanner motor with the wire provided in
the rear frame side according to the speed corresponding to each
magnification ratio.
To move the lens unit and the No. 4 and No. 5 mirror unit, the
stepping motor is used.
(Drive section)
No.4/5 mirror unit
SL3 SL4
ON OFF
No.1 mirror unit
Light source unit
Copy lamp
To the photocondactor
drum
Th lens and mirrors (No. 4 and No. 5) are moved and stopped at
positions corresponding to maginifcation ratios by the mechanism
composed of the carriage rack and the magnification ratio shift cam.
No.2/3 mirror unit
Original table
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No.6 mirror unit