Mindray BeneVision N19 - Display Brightness Control

BeneVision N22/BeneVision N19 Patient Monitor Service Manual 2-11
2.4.3 Display Brightness Control
The physical architecture is as shown below:
N22/N19 System
Secondary display
Front interface board (all-in-one or split type)
Main board
Brightness
control
module
Backlight
Current
or voltage
USB&DP
DC-DC board
UART
Power
management
firmware
AC / Power
switching
test
System
software
Firmware of
the front
interface
board
Front interface board (all-in-one or split type)
Firmware of
the front
interface
board
USB&DP
Ambient light
detection
Brightness
control
module
Backlight
Current
or voltage
Ambient light
detection
As shown in the figure above, the dashed line indicates the fast hardware channel reserved for the AC battery switching
event.
During operation, the system software adjusts the display brightness of the primary screen or secondary screen by
directly sending command to the primary screen or secondary screen, and the CPU within the primary screen or
secondary screen adjusts the backlight accordingly.
When using AC power supply, the main unit automatically identifies the power switch if the power switches to the
battery in case of sudden AC power off. The main unit sends command to the primary screen, and the brightness of the
primary screen is set down automatically.