Electrophotographic process (EP process)
Printhead
The printhead scans the photo conductor drum surface with a laser beam. It consists of the following components:
•
Laser diode (LD) card assembly
•
Oscillator
•
Start of scan card assembly
When a laser beam is scanned across the photoconductor drum surface from one end to the other while turning on
and off the beam, one line of latent image is created. If the scanning by the laser beam is repeated while rotating the
drum, a two-dimensional image is created. The resolution in the scanning direction (from right to left) is determined
by the rotational speed of the printhead motor, depending on how quickly the laser is adjusted. The resolution in the
process direction (from top to bottom) is determined by the rotational speed of the printhead motor. The higher the
scanning speed becomes, the sooner the scanning of the next row can be started.
Step 1: Charge
During the charge step, voltage is sent from the HVPS to the charge roll beside the photoconductor. The charge roll
applies a uniform negative charge over the entire surface of the photoconductor to prepare it for the laser beam.
HVPS
(-VDC)
(-VDC)
Ground
Conductive Tube
Photoconductive
Surface
0V
-VDC value
DRUM
Drum Surface
Voltage
Drum Surface
Image
Ground
Charge roll
4514
Appendix C: Theory of operation
283
Summary of Contents for M1140
Page 18: ...4514 18 ...
Page 20: ...4514 20 ...
Page 142: ...4514 142 ...
Page 197: ...b Set the spring over the plunger 4514 Repair information 197 ...
Page 204: ...3 Squeeze the latches B to release the left and right links B 4514 Repair information 204 ...
Page 228: ...10 Remove the screw C and then detach the trailing edge sensor A 4514 Repair information 228 ...
Page 229: ...11 Disconnect the two springs D 4514 Repair information 229 ...
Page 246: ...3 Swing the right cover backward to remove 4 Remove the screw D 4514 Repair information 246 ...
Page 248: ...4514 248 ...
Page 253: ...4514 253 ...
Page 255: ...Assembly 1 Covers 4514 Parts catalog 255 ...
Page 257: ...Assembly 2 Electronics 1 4514 Parts catalog 257 ...
Page 259: ...Assembly 3 Electronics 2 4 3 2 1 6 5 4514 Parts catalog 259 ...
Page 261: ...4514 Parts catalog 261 ...
Page 262: ...Assembly 4 Frame 4514 Parts catalog 262 ...
Page 264: ...4514 Parts catalog 264 ...
Page 265: ...Assembly 5 Option trays 3 4 5 6 1 2 4514 Parts catalog 265 ...
Page 268: ...4514 Parts catalog 268 ...
Page 270: ...4514 270 ...
Page 274: ...4514 274 ...
Page 276: ...4514 276 ...
Page 298: ...4514 Part number index 298 ...
Page 302: ...4514 Part name index 302 ...
Page 303: ......