Lsu Control Circuit - Panasonic DF-1100 Service Manual

6.2.13 LSU Control Circuit

The laser control signals are described below.
nLDON
The LSU is activated when this output signal is LOW. If an error occurs, the nLDON output signal level goes
High and the LSU is deactivated.
nVIDEO
This is the actual Data Signal. The Laser is ON when the nVIDEO output signal level is LOW.
nHSYNC
This horizontal synchronization signal transmitted from the Beam Detection Sensor sets the horizontal
position of the laser beam as it crosses the OPC Drum.
nPMON
This is the Polygon Motor Control Signal. The Polygon Motor rotates when the nPMON output signal level
is LOW.
nPMRDY
A Phased–Lock Loop (PLL) circuit keeps the Polygon Motor speed constant at 10,000 rpm when the
nPMRDY is at a Low output signal level.
VDO Signal
IC51
CPU
IC52
1
3
2
+5V
1
R412
2
36
R409
20
61
LPC PCB
Laser Unit Control Circuit Block Diagram
CN51
5 nVIDEO P101
Laser
4 nLDON
Drive
Circuit
1 nHSYNC
9 nPMON CN1 Polygon
Motor
7 nPMRDY
Drive
Circuit
LSU
System Description
Laser
Timing
Sensor
Polygon
Motor
6–35