Technical information

CHAPTER 3
OPERATIONS AND TIMING
Inoutlinediagrams,-- representsmechanícaldrivepaths,andmindicateselectricalsignal
paths.
Signals in digital circuits are identified as ‘1’ for High and ‘0’ for Low. The voltage of signals,
however, depends on the circuit.
Nearly all operations of the copier are controlled by microprocessors; the interna1 workings of
these processors are not relevant to the serviceman’s work and, therefore, left out of the
discussions. By the same token, no repairs are prescribed for the PCBs at the user’s premises;
for this reason, PCBs are discussed by means of block diagrams rather than circuit diagrams.
Forthe purpose of explanation, discussions are divided into the following: from sensors to DC
controllerPCBinputports;fromDCcontrolleroutputportstoloads;andminorcontrolcircuitsand
functions.
1. BASIC MECHANISMS..
........................
3-1
V.
POWER SUPPLY
.................................
3-52
II.
EXPOSURE SYSTEM
..........................
3-13
VI.
SERVICE MODES
................................
3-55
III.
IMAGE FORMATION SYSTEM
............
3-24
VII.
SELF DIAGNOSTIC MECHANISM..
..... 3-57
IV.
PICK-UP/FEED SYSTEM
.................... 3-39
COPYRIGHT 0 1992 CANON ING.
CANON HPZl20/2GZO RN.0 MAY 1990 PAINTEU IN JAPAN [IMPRIME AU JAPON]