MX-1800N (serv.man28). Details of each Section - H LSU Section - Sharp Copying Equipment Service Manual (repair manual). Page 2

MX-1800N  LSU SECTION  H – 2

Image data sent from the image process circuit through the mother
are converted into laser beams to be radiated onto the OPC drum
surface. The LSU unit is composed of the primary system including
optical elements such as lasers and the polygon mirror and the mir-
ror which assures the optical path and the scan system which
includes the optical elements including the polygon mirror and the
mirror which assures the optical path. 

(Primary system)

(Scan system)

(On the polygon mirror)

PGM

Polygon motor

Laser beam is reflected at the constant speed rotation.

1

LD PWB (K)

Controls laser beam flashing and the output value.

2

LD  PWB  (C)

3

LD PWB (M)

4

LD  PWB  (Y)

5

Cylindrical lens

Converges laser beams and focus. 

6

f

θ lens 1

Laser beams are refracted so that the laser scan speed on the OPC drum is even in both ends and at the center.

7

f

θ lens 2

8

Reflection mirror

Secures the path for laser beams.

9

Cylindrical lens

Converges laser beams, and focus on the OPC drum.

10

OPC drum

Forms electrostatic latent images according to laser beams.

11

Convergence lens for BD

Converges laser beams to the BD PWB.

12

BD PWB

Detects the timing for starting laser scanning.

13

LSU CNT PWB

Laser beams are controlled and the polygon motor control signal is generated according to the PCU PWB control 
signal and image data. 

14

LSU therminstor

Measures the temperature in LSU.

MX-1800N

7 surfaces

25106rpm

OIL

Effective scan width:

307mm

Resolution:

600dpi

Beam diameter:

Main scan = 50 to 65µm,  Sub scan =  60 to 75µm

Laser power:

Max. 0.65mW

LD wavelength:

770 to 795nm