Minolta CF910 Service Manual page 61

PWB-JD
FIFO Memory
γ Correction Circuit
New Screen LIMOS
Processing Circuit
Print Area Control
PWB-JA
Max. LD1 Determines the maximum intensity of the LD1 light according to the PC Drum
Intensity Control sensitivity and applies it to the D/A Converter.
(The higher the sensitivity of the PC Drum, the smaller the maximum inten-
sity.)
D/A Converter Converts digital image data to a corresponding analog voltage.
•
Bias Intensity
Control
•
Adder Adds the image data analog voltage to the bias intensity voltage.
•
Intensity Monitor
•
Differential Compares the voltage specified by the Adder with the monitor voltage pro-
Amplifier vided by the Intensity Monitor to vary the voltage output to the LD1 Driver.
Specified Voltage > Monitor Voltage
Specified Voltage < Monitor Voltage
Controls the intensity of the LD1 light according to the
LD1 Driver
analog voltage of the image data.
IR Digital image data
Corrects the processing speed for the image data transmitted from IR
to match with that of the PH.
•
LIMOS I and New Screen LIMOS processing tables are provided for
each color of C, M, Y, and Bk (thus a total of eight different types of
tables).
•
Any of the processing tables is selected for the image data.
Performs New Screen LIMOS processing only for the image data of dot
and continuous gradation areas and photo.
Generates an HIA signal, HIA inside signal (main scanning direction)
and VIA signal (sub-scanning direction) to set the laser beam area in
the main and sub-scanning directions that varies for different paper
sizes and zoom ratios.
Applies a voltage to LD1 in advance of its emitting a light as LD1 needs to
be very quick in responding to an emission request.
This voltage is called the bias intensity voltage.
A photodiode (PD) is used to convert the actual intensity of the LD1 light to
a current value which is fed back to the Intensity Monitor.
The Intensity Monitor converts this current value to a corresponding volt-
age value and outputs it to the Differential Amplifier.
M-44
Voltage Output to LD1 Driver
Increased
Decreased