Sony UP895 Service Manual - Page 27

Circuit Operation Description, A/D and D/A converters - up 895 paper

Page 27 highlights

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. UP-895/(E) 4-1

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 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.