The power source (VHD) is supplied to the thermal head when the plotting
signal turns on. When the plotting signal turns off, a relay (RA701) on the
thermal head drive PCB cuts the power line.
The energy applied to the thermal heating elements is determined by the
length of the time (t) when power is applied. This time in turn is controlled by
the pulse (ENR) length generated in the main PCB. The pulse signal (ENR) is
sent to the thermal head drive PCB through the image processing PCB. The
pulse signal is split into four pulse signals (ENR 1 to 4) in the thermal head
drive PCB. Then, they are separately applied to the four blocks (1152
elements each) of the thermal head.
The thermistor on the thermal head detects the thermal head temperature.
The detected temperature is sent to the pulse generator in the main PCB,
and the pulse generator controls the length of the pulse (ENR) based on the
temperature. (See graph.)
5120
t
ENR
ENR 1
ENR 2
ENR 3
ENR 4
LSYNC
1 line
Long
Low
High
Short
ENR
Pulse
Length (t)
Thermal Head Temperature
1 December 1993
2-134
Содержание VT3500
Страница 8: ...2 6 USER CODE MODE 4 27 2 6 1 User Codes 4 27 2 6 2 How To Use a User Code 4 27...
Страница 15: ...SECTION 1 OVERALL MACHINE INFORMATION...
Страница 19: ...2 GUIDETOCOMPONENTSANDTHEIRFUNCTION 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 1 December 1993 1 5...
Страница 21: ...16 17 18 19 20 21 22 23 24 25 26 27 28 1 December 1993 1 7...
Страница 37: ...SECTION 2 SECTIONAL DESCRIPTION...
Страница 89: ...E H D G F D C A B C I J K 1 December 1993 2 53...
Страница 123: ...1 December 1993 2 87...
Страница 127: ...1 December 1993 2 91...
Страница 161: ...Background Patterns The 40 background patterns shown below can be selected 1 2 3 4 5 6 7 8 9 1 December 1993 2 125...
Страница 162: ...13 14 15 16 17 18 10 11 12 1 December 1993 2 126...
Страница 163: ...19 20 21 22 23 24 25 26 27 1 December 1993 2 127...
Страница 164: ...28 29 30 31 32 33 34 35 36 1 December 1993 2 128...
Страница 165: ...37 38 39 40 1 December 1993 2 129...
Страница 192: ...SECTION 3 INSTALLATION...
Страница 206: ...SECTION 4 SERVICE TABLES...
Страница 209: ...Q Fig 4 R S Fig 5 T U Fig 6 V Fig 7 1 December 1993 4 3...
Страница 234: ...SECTION 5 REPLACEMENT AND ADJUSTMENT...
Страница 317: ...SECTION 6 TROUBLESHOOTING...