Sharp SF-1120 - Manual (Page 32)

3) Basic operations
(Cassette paper feed)
When the CPFC (cassette paper feed clutch) is turned on, the paper
feed roller shaft, the paper feed roller, and the take-up roller rotates in
the direction of A, and the roller release arm is moved downward by
the limiter spring. As a result, the take-up roller falls by its weight to
reach the paper surface, feeding the paper. When the CPFC is turned
off, the take-up roller is pushed up to the position by the roller release
arm spring.
(3) Optical section
1. General description
• The optical section of this model is composed of the fixed focus
lens and six mirrors. Since the fixed focus lens is used, No. 4/5
mirror base is shifted according to the shift of the lens to change
the distance between the original and the drum (OID, Original
Image Distance) in reduction or enlargement copy.
The lens and No. 4/5 mirror unit are shifted by driving the stepping
motor with the signals from the main control PWB, allowing zoom-
ing of 151 steps in 1% increment in the range of 0.50 to 2.00. • Exposure is adjusted by changing the copy lamp voltage. The AE
sensor is provided in the zoom base to sense the density of the
original.
The copy lamp light is reflected by the original to the AE sensor,
which senses the density of the original and adjust the copy lamp
light quantity according to the density.
• The exposure system is the slit exposure system by moving light
source.
Stirring roller
MG roller
Proccess
unit
DV drive unit
Main drive unit
Main motor
Fuser unit
PS roller
Multi manual
insertion paper
feed unit
(Option)
Cleaner
unit
Paper exit
roller
Transport
roller(upper)
Transport
rolle r(lowe r)
Paper feed
rive unit
Paper feed
unit
Paper feed
unit
Transport
unit
5 6 9 10
14 8 12
15 1 2 3 7 11 13 16 4 17
1 Copy lamp 2 Reflector 3 No. 1 mirror
4 No. 2 mirror 5 No. 3 mirror 6 Lens
7 No. 4 mirror 8 No. 5 mirror 9 No. 6 mirror
F No. 2/3 mirror base unit G Copy lamp unit H No. 4/5 mirror base unit
I Mirror motor J Lens/No. 4/5 mirror base drive motor K Lens home position sensor
L Mirror home position sensor M Automatic exposure (AE) sensor/
Optical system dirt sensor
5 – 3