Sony UP-D2600, Service Manual

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4-17
UP-D2600/V1(E)
Head Control Block
The head control block proccess the parallel print data for each line from the IF-787 or IF-788 board and
sends it to the thermal head for printing.
The head control block is constituted by the following five sections.
.
γ
ROM that
γ
collects the parallel print data from the IF-787 or IF-788 board.
.
Image processing IC(Picture Quality Control IC) that performs pattern recognition interpolation, edge
emphasis, and heat accumulation correction.
.
Head driving IC that PWM-converts parallel data and sends print data to the thermal head.
.
Line number correction IC (Voltage drop control IC) that corrects voltage drop by common resistor of
the thermal head.
.
Head voltage correction circuit
The print data is received from the IF-787 or IF-788 board as parallel data for
γ
correction. Each signal
processing is added by PQC IC. After that, PWM modulation is performed by head driving IC and the
print data is sent to the thermal head.
16
2
14
ELEMENT DATA
CONTROL
5
5
8
3
9
8
CONTROL
ADDRESS
DATA
LATCH
γ
- ROM
2 1 8 6 8 8
8
8
2
DMA CONTROL
PRINT DATA
DMA CONTROL
PRINT DATA
T h e r m a l
H e a d
D r i v e
I C
V o l t a g e
D r o p
C o n t r o l
I C
PRINT DATA
LATCH
DCX
STROBE
THERMAL HEAD
P i c t u r e
Q u a l i t y
C o n t r o l
IC
DATA
IF-787 or IF-788 board
CPU
CONTROL ADDRESS DATA CONTROL ADDRESS DATA
Image processing block Thermal head driving block
γ
correction block
Line number correction processing block