TCL LED and LCD Panel Training Schematic
Training Manual of Panel
(CCFL & LED)
CCFL Lamps Appearance
U-shapes lamps
straight lamps
M-shapes lamps
Inverter Board
Power supply voltage board and
inverter board is one PCB
Inverter board
TFT-LCD Imaging Principle
1:Scan IC transmission signal
2:Driver IC transmission imaging control signal
3:When one sub-pixel cut-off, the sub-pixel cannot get light to show black.
4:If sub-pixel cut-off ,but light through the color filter and display color
5:After the synthesis of light effects, the display can produce color effects.
Color filter
enlarge
TFT-LCD Imaging Principle
TFT-LCD Imaging Principle
CCFL backlight LCD TV
4unit CCFL
small size
LCD TV
Lots of CCFL
big size LCD
TV
CCFL is not produce display signals , only provide light source.
Inverter board is a DC to AC converter. It is low-voltage DC convert into high-
voltage AC, and supply to light up CCFL lamps.
CCFL Parameters
Parameter Symbol
Values
Unit
Min Type Max
Operating Voltage V
BL
655 685 805 V
RMS
Operating Current I
BL
3.0 5.0 6.0 mA
RMS
Starting Voltage(at 0 C)
Vs 1370 V
RMS
Operating Frequency F
BL
45 58 80 kHz
Power Consumption P
BL
3.43 3.77 Watt
Inverter parameters(size:24)
Item symbol unit
value
remark
MIN TYP. MAX
输入电压input voltage
Vin V 9 12 16
工作频率operate
frequency
foper kHz 40 50 80
调光电压dimming
voltage
Vdim V 0 5 Anode or
cathode
dimming
灯管电流lamp current
Ilamp mArms 3.0 7.5 8.0
工作电压
Operating voltage
Vlamp Vrms 700 880 I lamp=7.5mA
启动电压
Start-up voltage
Vopen Vrms 1250 Ta = 25 ºC
1650 Ta = 0 ºC
启动时间start-up time
Ts S 1 3
CCFL Operate Voltage Waveform
• CCFL lamp light, the
voltage drop large,
sine waveform change
some distortion
CCFL operate voltage
is 765V,normal CCFL
operate voltage is
600V---800V,start
voltage is as high as
1500V—1800V
Distortion sine waveform
765V
Block Inverter Diagram
Brightness
adjustment
Input
CCFL and LED Dimming
Imax
inverter
fb
Vadj out
Duty cycle regarding large dimming
fb
Vadj
inverter
out
Duty cycle regarding small dimming
Imax
LED dimming pricinple(PWM mode)
inverter
fbVadj
out
Imax
inverter
fbVadj
out
Imax
Duty cycle regarding large dimming
Duty cycle regarding small dimming
CCFL dimming pricinple(Analog mode)
LED Chip Structure
LED Chip Structure
White LED structure
From phosphor layer
From LED
Large area phosphor layer
High Brightness LED Structure
LED Advantages
•Low power consumption
• Extremely long lifetime
• Very low early failure rate
• Smallest
• Shockproof
• Does not produce UV radiation
Or intermediate frequency
interference
• Low power
• Light through the optical lens
transmitted out
• High color efficiency
•Low voltage
LED Bar of LED TV
•By a number of independent
white LED light strip solder into
the PCB (or aluminum plate)
Installed in the frame on the
screen (the side, both sides or
multilateral)
•Light of the length and the
number of LED lamps according
to the size of screen size varies
•The LED light on the many uses
of the series (some machines will
be used in parallel or seriesparallel hybrid) connected
•A single light on one or more
strings of LED
•Require specialized multi-string
LED constant current driver circuit
to drive
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