Sony UP-895, Руководство по обслуживанию

Страница: 27 / 84

4-1
UP-895/(E)
Section 4
Circuit Operation Description
Outline
The electrical circuit of UP-895 mainly consists of the following blocks.
*
Video circuit
The input video signal is amplified using a video amplifier circuit to perform brightness, contrast, trap
filter, and AGC processing.
*
A/D and D/A converters
The analog signal output from a video circuit is converted from analog to digital. The A/D-converted
data is converted from digital to analog to output it to the outside.
*
Memory and head control G/A
Print data is fetched to frame memory (DRAM). Image data on the memory is also PWM-converted for
image processing and sent to the thermal head.
*
CLK generator
This block generates the operation clock of memory and head control G/A.
*
Frame memory (SDRAM)
This block memorizes print data.
*
Motor drive
Each motor of a head, platen, and fan is driven according to the command from system control CPU.
*
Sensor circuit
This block detects the sensor values of a head, paper, cutter, door, and head temperature.
*
System control CPU
This block supervises and controls each block.