Panasonic DP-CL18 Technical Manual page 22

DP-CL18
3.5.3. LSU Drive Circuit
nVIDEO_K, nVIDEO_C, nVIDEO_M, nVIDEO_Y :
NENB :
NADJUSTK, NADJUSTC, NADJUSTM, NADJUSTY : Prior to scanning each color horizontal line ( Black, Cyan, Magenta, Yellow ), the output
PSEL :
NBDK :
PMCLK :
PMCTL :
NPMLD :
These signals are the actual raster image data being printed for each color ( nVIDEO :
Black, nVIDEO_C : Cyan, nVIDEO_M : Magenta, nVIODE_Y : Yellow ).
When the signal nVIDEO_K ( pin 3 of IC13 ) is a low, the laser for black color is turned on.
When the signal nVIDEO_C ( pin 6 of IC13 ) is a low, the laser for cyan color is turned on.
When the signal nVIDEO_M ( pin 8 of IC13 ) is a low, the laser for magenta color is turned
on.
When the signal nVIDEO_Y ( pin 11 of IC13 ) is a low, the laser for yellow color is turned
on.
When the signal NENB ( pin 2 of IC19 ) is a low, the laser scanning unit is activated.
power of the laser diode is adjusted.
When the signal ( NADJUSTK : Black, NADJUSTC : Cyan, NADJUSTM : Magenta,
NADJUSTY : Yellow ) is a low, each color auto power circuit inside the laser scanning unit
is activated to keep the laser power constant. After adjusting the laser power, the signal
becomes a high.
This is the laser optical power selection signal.
When printing at 600 dpi, the signal PSEL ( pin 4 of IC19 ) is a low and the laser power
is a high.
When printing at 1200 dpi, the signal PSEL ( pin 4 of IC19 ) is a high and the laser power
is a low.
This is a horizontal signal sent from the laser scanning unit, which detects the horizontal
position of laser beam across the OPC ( photoconductive belt ) roller.
The relation between this signal and video signals ( nVIDEO_, nVIDEO_C, nVIDEO_M
and nVIDEO_Y ) is indicated in the following Timing Chart.
This is the external clock signal for the polygon motor.
At printing, the frequency of signal PMCLK ( base of transistor Q31 ) is 1,771.7 Hz for color
mode, and 2,196.9 Hz for monochrome mode.
This is the control signal for the polygon motor. When this PMCTL signal ( base of Q30 )
is a high, the polygon motor rotates.
This is the polygon motor lock detection signal sent from the polygon motor driver board
in the LSU. The polygon motor speed is kept at 17,717 rpm for color printing, and 21,969
rpm for monochrome printing. When the polygon motor is rotating at 17,717 rpm or 21,969
rpm, this signal NPMLD is a low. If the polygon motor speed is not 17,717 rpm or 21,969
rpm, this signal is a high. The call service code " Printer Error 10 " is displayed on the LCD
display.
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