4-18 Product Principle
4.7 Touch Screen Unit
Main control board
Touch
screen
control
board
Parameter boardDisplay
Back-end motherboard
+12V
+5V VGA I2C
LVDS
+12V
3.3V
Parameter
communication
brightness feedback
Touch
screen unit
USB +5V
Control panel
Touch
screen
Backlight
control
Fig 4-22 Schematic diagram of touch screen
Touch screen unit mainly consists of main control board, parameter board, LCD, touch screen,
touch screen control board, etc.
Function:
 Touch screen: 10.4 inches, 5-line resistor
 The touch screen control board controls the touch screen, responds to the touch screen
operation, and communicates with the main system through USB port.
 The main control board transfers the VGA input into LVDS signal output to the LCD screen, and
monitors other boards or signal.
 The parameter board communicates with the main control board, controls the parameters and
brightness feedback.
4.8 Power Supply Unit
Power supply unit provides power to the system (front-end, back-end, peripherals, etc.). The power
supply unit consists of power connecting board/isolation transformer, AC-DC power board,
front-end power board, back-end power board, and battery module, etc. Of which, the front-end
power board consists of front-end power main board and front-end auxiliary board.