Sony UP-D70XR, Руководство по обслуживанию

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4-11
UP-D70XR
3. Thermal Head Control Section
Data current of thermal head control section is as follows.
Memory
→
Gray correction
→
Picture quality correction IC
→
Resistance value correction
→
Drive
IC
→
Thermal head
a) Gray correction IC
When printing, gray balance correction curve of number that is set at [GRAY ADJUST] of ordinary
menu is stored at gray correction SRAM (IC203).
Self diagnosis of address and data bus of gamma SRAM peripheral can be performed.
b) Picture quality correction
IC204 outputs request signal to the memory at rising edge of PRINT_PLS0 from CPU. And receives
the gray corrected data.
IC204 performs gamma correction edge emphasis and heat store correction and outputs to the next
with 1 line delayed. Gamma correction curve is stored at flash memory (IC112).
When printing, gamma curve is selected and stored at IC204 by temperature of the time and a kind of
paper.
c) Resistance value correction
This is composed by two ROMs, IC205 (Resistance value data of the head) and IC206 (Resistance
value correction curve).
d) Drive IC
IC208 to 210 output request signal to IC204 at rising edge of PRINT_PLS1 from IC204. And
receive the resistance value corrected data, and send PWM converted data to the head with 1 line
delayed.
Output data of IC208 : CN7-1 to 8
Output data of IC209 : CN7-9 to 16
Output data of IC210 : CN7-17 to 20
Furthermore, IC208 outputs HED_CLK (CN7-22) and HED_LATCH (CN7-24) to the head.
Data
Data
From IC204
Clock
Counter
A0
to
A10
D0
to
D7
27C256
A8
to
A15
A0
to
A7
D0
to
D7
27C512
To IC208-210