Post on 24-Oct-2014
transcript
Training Manual of Panel(CCFL & LED)
CCFL Lamps Appearance
U-shapes lamps
straight lampsM-shapes lamps
Inverter Board
Power supply voltage board and inverter board is one PCB
Inverter board
TFT-LCD Imaging Principle1: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 filterenlarge
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 SymbolValues
UnitMin Type Max
Operating Voltage VBL 655 685 805 VRMS
Operating Current IBL 3.0 5.0 6.0 mARMS
Starting Voltage(at 0 C) Vs 1370 VRMS
Operating Frequency FBL 45 58 80 kHz
Power Consumption PBL 3.43 3.77 Watt
Inverter parameters(size:24)
Item symbol unitvalue
remarkMIN 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
Imaxinverter
fbVadj outout
Duty cycle regarding large dimming
fbVadj
inverter
out
Duty cycle regarding small dimming
Imax
LED dimming pricinple(PWM mode)
inverter
fbVadj out
Imax
inverter
fb Vadj 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 series-parallel hybrid) connected•A single light on one or more strings of LED•Require specialized multi-string LED constant current driver circuit to drive
LED TV Structure
LED vs CCFL• Brightness and the startup time
CCFL LED
LED vs CCFLLight remote control interference
CCFL Spectrum LED Spectrum
LED vs CCFL
CCFL : need additional start-up high –voltage,stimulate mercury vapor.
LED : The use of stable DC power supply, no additional start-up high-voltage
LED TV And LCD TV Differences
• LED TV and LCD TV's biggest difference is the different use of the backlight
• LCD TV uses CCFL (Cold Cathode Fluorescent Lamp) lamps, CCFL drawback is that lifetime
is short compared with LED and CCFL using raw materials containing mercury, mercury
pollution of the environment is a big injury
• LED TV: LED backlight that is used LED lamps. The disadvantage is higher the cost of LED
than CCFL , but lifetime is longer compared than the CCFL, and the mercury-free, less
environmental damage
CCFLLED
LED and CCFL Backlight Compare
• Environmental protection(Material does not contain mercury)
• Currently CCFL light efficiency of 60 to 100lm / w
• Currently LED light effect can be achieved about120lm / w
• Low power, Follow-up development can be achieved higher
• long lifetime(Up to 100,000 hours)
• support collor is very wide:excellent display color
• DC driver, Easy to dynamically adjust the brightness
• safety: CCFL high-voltage drivers, LED drivers only need low-voltage
• CCFL for the fragile glass products, LED chips for the semiconductor solid-state
LCD Panel Block Diagram
T-CON Board Introduction
Inverter Board Introduction
TFT-LCD Block Diagram
Power Converter(DC/DC Converter)
TimingController
VcomGamma
ReferenceVoltages
Source Drivers
Gat
e D
river
sTFT-LCD Panel
Data In(LVDS)
Backlightinverter Lamps
Power Infor
signal
Power Infor
Inverter
RSDS
Timing Controller
LVDSRx
ACC DCC
DataController
MemoryController
PLL
T-CON
RSDSRx
RSDSRx
SSCEEPROM
Memory(DDR)
LVDS Tx
FrontRSDSData
BackRSDSData
ACC : Accurate Color Capture DCC : Dynamic Capacitance Compensation
Control Signal&
Gate Signal
SSC : Spread Spectrum Clock
Input Signal DE Mode Only RGB 24bit Data Clock
LVDS Signal Input Data VESA JEIDA
RxIN0
RxOUT0 R0 R2RxOUT1 R1 R3RxOUT2 R2 R4RxOUT3 R3 R5RxOUT4 R4 R6RxOUT6 R5 R7RxOUT7 G0 G2
RxIN1
RxOUT8 G1 G3RxOUT9 G2 G4
RxOUT12 G3 G5RxOUT13 G4 G6RxOUT14 G5 G7RxOUT15 B0 B2RxOUT18 B1 B3
RxIN2
RxOUT19 B2 B4RxOUT20 B3 B5RxOUT21 B4 B6RxOUT22 B5 B7RxOUT24 HSYNC HSYNCRxOUT25 VSYNC VSYNCRxOUT26 DE DE
RxIN3
RxOUT27 R6 R0RxOUT5 R7 R1
RxOUT10 G6 G0RxOUT11 G7 G1RxOUT16 B6 B0RxOUT17 B7 B1RxOUT23
LVDS Signal Format
Resolution Aspect Ratio No. of Pixel Panel Size
HD15:9 1280 x 768 17”, 19”
16:9 1366 x 768 23”, 26”, 32”, 40”, 46”
FHD 16:9 1920 x 1080 40”, 46”, 5X”
Resolution of LCD TV
Signal Item Symbol Min Typ Max Unit
Clock
Frequency
Fclk 60 80 85 MHz
Hsync Fh 43 50 53 KHz
Vsync Fv 48 60 66 Hz
Horizontal timing
Display period
Thd - 1366
(1280)*- Clocks
Total Th 1368 1600 1800 Clocks
Vertical timing
Display period
Tvd - 768 - Lines
Total Tv 773 838 1200 Lines
Input Timing
Resolution : 1366 x 768
LVDS Format Option High : VESA, Low : JEIDA
No Signal No Signal
1 Vin(+5V) 11 GND
2 Vin(+5V) 12 Rclk-
3 Rx0- 13 Rclk+
4 Rx0+ 14 GND
5 GNN 15 Rx3-
6 Rx1- 16 Rx3+
7 Rx1+ 17 GND
8 GND 18 GND
9 Rx2- 19 LVDS Option
10 Rx2+ 20 N.C
Connector: DF14A-20P-1.25H(HIROSE) or Compatable
Model : 17”, 19”, 23” - HD
Input Pins Assignment
LVDS cable
No Signal No Signal
1 N.C(#1) 16 GND
2 N.C(#2) 17 Rx3-
3 N.C(#3) 18 Rx3+
4 GND 19 GND
5 Rx0- 20 N.C(#4)
6 Rx0+ 21 LVDS Option
7 GND 22 N.C(#5)
8 Rx1- 23 GND
9 Rx1+ 24 GND
10 GND 25 GND
11 Rx2- 26 Vdd(+5Vdc)
12 Rx2+ 27 Vdd(+5Vdc)
13 GND 28 Vdd(+5Vdc)
14 RxCLK- 29 Vdd(+5Vdc)
15 RxCLK+ 30 Vdd(+5Vdc)
Input Pins Assignment Connector: FI-E30S(JAE) or Compatible
Model : 23”, 26”, 32”, 40” - HD
LVDS Format Option High : VESA, Low : JEIDA
LVDS cable
Input Pin Assignment Connector: FI-E30S(JAE) or Compatable
Model : 40”, 46 - FHD
No Signal No Signal
1 Odd Rx0 - 16 Even Rx2 +
2 Odd Rx0 + 17 Even RxCLK -
3 Odd Rx1 - 18 Even RxCLK +
4 Odd Rx1 + 19 Even Rx3 -
5 Odd Rx2 - 20 Even Rx3 +
6 Odd Rx2 + 21 Ground
7 Odd RxCLK - 22 Ground
8 Odd RxCLK + 23 Ground
9 Odd Rx3 - 24 Ground
10 Odd Rx3 + 25 Ground
11 Even Rx0 - 26 5V Input
12 Even Rx0 + 27 5V Input
13 Even Rx1 - 28 5V Input
14 Even Rx1 + 29 5V Input
15 Even Rx2 - 30 5V Input
LVDS Cable
Connector : S14B-PH-SM3(JST) or Compatible
No Pin Name Pin Configuration
1 Vin Typ 24V
2 Vin Typ 24V
3 Vin Typ 24V
4 Vin Typ 24V
5 Vin Typ 24V
6 GND Ground
7 GND Ground
8 GND Ground
9 GND Ground
10 GND Ground
11 NC No Connection
12 B/L On/Off Inverter Enable
13 ADIM Analog Dimming
14 PDIM PWM Dimming
B/L On/Off 3.3V : On, 0V : Off
Analog Dimming 3.3V : Max, 0V : Min
PWM Dimming Duty 30% : Min, Duty 100% : Max
Input Pin Assignment(Inverter)
Inverter cable
19” 23” 26” 32” 40”
Lamp 6 U-Lamps 6 U-Lamps 8 U-Lamps 16 Lamps 20 Lamps
Input Voltage 24V 24V 24V 24V 24V
Output Current 4.5/~ /6.5 4.0/~ /7.0 4.5/5.5/6.5 4.0/5.5/7.0 4.0/5.5/7.0
PWM Dimming 30% 30% 30% 30% 30%
Analog Dimming O O O O O
PWM Frequency
170Hz 170Hz 170Hz 170Hz 170Hz
Lamp Frequency 60KHz 60KHz 60KHz 60KHz 60KHz
PowerConsumption
50W 70W 80W 110W 180W
Inverter Specifications
LED Backlight Driving Principle
Control Signal
It is panel ( part NO.:LC420WUE-SBA) power sequence
LCD Driving Circuit
It is panel ( part NO.:LC420WUE-SBA) power sequence
Power Sequence
TCL 26D20 LED drive circuit
26D20—MP3389 is step-up control for 12 strings LED driver
DC=24V to DC=12V converter
24Vconverter 38V DC-DC and Multi-channel constant current control output voltage
divider resistor
Adobe Acrobat Document
backlight ON/OFF control signal
PWM dimming signal
MP3389’s Circuit
Fromt mounting bracket
Panel serial NO.
After taking out open cell,we can see protection sheet
Take care braket
12
3
4
protection sheet
prim sheet(vertical)
prim sheet(horizontal)
Diffuser sheet
Cable
LED Panel Structure IntroductionFront LCD PANEL
Inverter board
T-con board
Open cell
Source board
Take care Tape Carrier Package
CCFL’S Socket
LED Panel Structure Introduction
LED lamp
Inverter board
Panel Serial NO.
T-CON board
LED poower supply socket
Front mounting bracket
Flexible printed cable
12
3
4
protection sheetprim sheet(vertical)
prim sheet(horizontal)
Diffuser sheet
LED panel
Open cell
After taking out open cell,we can see protection sheet
Backlight Structure Introduction
Power supply socket
Qty’s LED lamps:18 unit Qty’s LED lamps:18 unit
Two LED modules are parallel If Vinput=57V,Vone led=57/18=3.2v,so that one LED’s voltage is very low
For example:Part NO.: 4A-LCD32T-AUC panel,there are 36 LED lamp each LED unit
Two LED diodes,if one diode is defetive,the other diode can keep LED to light,two diodes is defetive,all LED cannot light
Solder on the PCB
LED Panel Module Introduction
The Others Introduction Front cabinet Panel
Power supply board
Main board
Stand base component
Rear cabinet
Front cabinet Panel
Power supply board
Main board
Rear cabinet
Open cellBacklight module
Common LCD TV structure
The other LCD TV structure
Gate TCP
Explain: 1 、 Gate PCB and Source PCB and FPC in the Board
( FPC=Flexible Printed Cable , PCB=Printed Circuit Board )
2 、 TCP=Tape Carrier Package
Open Cell Structure
Source TCP
Source PCB+Gate PCB
Working Instruction of The Panel
CCFL bracket
Take care flexible printed cable
Reflector sheet
Assembly CCFL,take careCCFL not breaking
Take care :ccfl and socket connect
Assembly protection sheet\prim sheet(two\diffuser sheet
Assembly protection sheet\prim sheet(two\diffuser sheet
Finishing assemblying backliht module
Connect ground cable
Bring open cell to assembly
Put the open cell on the backlihgt module
Take care source gate board
Assembly bracket
Check here it is ok or not
Check panel it is ok or not
Tool’s moving opencell
LCD Trouble Shooting
Check power supply V=24V or 12V
CCFL is not light
Check power supply board
Check backlight on/off
Check main board Check backlihgt board
CCFL flash
Check backlight board
Check Vblihgt-dimming
or dimming
Check main board
N
N
N
Y
Y
Y
Y
( 1)
( 2)
N
Y
Check power supply V=24V
Check power supply board
N
N
Y
Check Vt-con?(power supplyof T-con board Vt-con)
Check Vt-con?(powersupply of T-con board Vt-con)
LCD Trouble Shooting
Check power supply V=24V or 12V
CCFL is light and then not light
Check power supply board
Check backlight on/offCheck main board
Check backlight board
check CCFL or connect to
CCFL cable or socket
checkCCFL or cable
N
NN
Y
Y
Y
ReplacePWM IC
N
NY
Y
CCFL is light to keep 2S,and then is
not light
Check CCFL socket Check CCFL’S socket or plug
Check transformer or feedback circuit
Check transformer’s voltage
Check OPV and OPC’s circuit
N
Check transformer’s feedback circuit
Check PWM’s OPV
and feedback circuit
Check MOS’S circuit
and feedback circuit
N
Y
Check transformer or capacitor
YY
Check OPC’s circuit
N
LCD Trouble Shooting
High Speed— megabits/second (Mbps) through gigabits/second (Gbps)
Low Power— x3.5mA current loop/output
Low Noise— low demands on power/ground— radiated electric fields tend to cancel
Low Cost— pure CMOS implementations
What is LVDS?
LVDS Timing
picture
HostSystemGraphic
Controller
T-conCMOS/TTL CMOS/TTL
Data(LVDS)
Clock(LVDS)
LVDS InterfaceData 4pair + Clock 1pair = 10 line
CMOS/TTL InterfaceData 24 line
Control 3 lineClock 1 line
CMOS/TTL InterfaceData 24 line
Control 3 lineClock 1 line
LCDModule
LVDS Tx LVDS Rx
▶ LVDS(Low Voltage Differential Signaling) - Interface between TV set and LCD module - 340mV swing - 7:1 Muxing - 100 ohm R-Termination - Reduce Data Bus Width
What is LVDS?
LVDS Signal Mapping
▶ RSDS( Reduced Swing Differential Signaling) - Interface between T-con and Source Drive IC - 200mV Swing - 2:1 Muxing - 100 ohm R-Termination - Reduce Data Bus Width
Driver
TFT - LCD
PANEL..
RowDriver
Timing Control
ColumnDriver
N
ColumnDriver
NColumnDriver
NSourceDriver
N
Driver
NSource
N
ONLY 24 Data Lines,RSDS (200mV) @ 80MHz
Row
. . . . . . . .
RGB Data(RSDS)Timing/Control
Clock(RSDS)
RSDSTx
TimingController
D0 D1 D0 D1 D0 D1 D0 D1 D0 D1
D2 D3 D2 D3 D2 D3 D2 D3 D2 D3
RSDS00
RSDS01
RSDSCLK
DIO
RSDS Signal Mapping
What is RSDS?
picture
TFT—Thin Film Transistor
LCD—Liquid Crystal Display
CCFL---Cold Cathode Fluorescent Lamp
LED-----Light Emitting DiodesHCFL -----Hot Cathode Fluorescent LampFMB ------Front mounting bracketFPC--------Flexible Printed Cable(It is the circuit that applies to printing circuit with LC driver IC and COG circuit interface.)TCP--------Tape Carrier Package BLU --------Back Light Unit CELL------- Cell( It is the panel of liquid crystal that fill into the micro meter gap formed by combining two glasses substrates.)Cell gap-----Cell Gap(It is the gap between ITO film on color filter substrate and TFT substrate.The size of the gap affects the transmittance of LCD display substrate and response time of liquid crystal.)CF-----------Color Filter (In order for LCD to generate colors,there is a pattern with Red,Green and Blue,which is one of the parts in the LC cell.Color filter is structured by 4 major components:Black Matrix to block light, pattern to display colors,transparent protection film made from protection pattern and transparent electrode film used for driver LC).CIE chromaticity diagram--------- CIE chromaticity diagram shows the graph of 2 dimensional color coordinate.On the XYZ color graph and X10Y10Z10 color graph,it uses x,y or x10y10 direct coordinate,and they are called CIE1931 color graph or CIE 1964 color graph.It is also known as xy or x10 y10 chromaticity diagram.
Appendix
Appendix COF-------Chip On Film(It is a simplified termof chip on film,which is a method of connecting IC chip to the electrode terminal of flexible printed circuit board.The specialty of this IC package method can thinner the flexible printed circuit board,which is about one third of thickness of TCP.It also increases the reliability of the liquid crystal display module.The current connecting processes used are:conductivity film,conductivity paste and eutectic conjunction.)
COG-------Chip On Glass(It is a process of connecting electrode terminal of idisplay glass sub strate and I/O of Driving IC directly to each other.The Driving IC must have bumping,and the material used for liquid crystal substrate bumping is Au.The manufacturing process,which uses ACF as its connecting material,is more matred.)
COP--------Chip On Plastic(It is a simplified term of Chip On Plastic,which is a method of connecting IC chip to the electrode terminal of plastic substrate.It is used for setting the driver IC onto the liquid crystal panel of plastic substrate.
Contrast ratio-----The ratio between the maximum and minmum brightness when the LC is On/Off.The contrast changes with different viewing angles,and therefore,maximum contrast ratio is used for display.Generally,STN is 10:1 and TFT is 100:1 for display.
Data line------It is the perpendicular wiring used in TFT substrate to transfer display signals.Because it is connected with the Source electrode or Drain electrode on each pixel in TFT,it is also known as Source line or Drain line.The width of the line is often between few um to 10 um.
Appendix Driver IC-------It is the IC that drives the LCD.There two types of display matrix:Scanning electrode(column electrode)Driver and Signal electrode(row electrode)Driver.The package of driver changes from QFP to TCP.The Driver IC of poly-silicon LCD panel forms directly in the display screen.
Gray scale----- Gray scale is for tuning the display between maximum and minimum brightness.When digital signal is input to it,according to2,3,4,6 and 8 bit,there are 4,8,16,64 and 256 different gray levels.Analogue input can be used for infinity level tuning display.There are two ways of gray scale:LCD driving voltage tuning and frame rate control.
LCD Driver--------LCD Driver is for driving LC panel circuit or IC.In matrix terms,it can be differentiated into column electrode Driver and row electrode Driver.
Scanning line------It is the horizontal wiring line,which transfers signal to the gate electrode in TFT board,It is also known as gate line.It also has the function to select horizontal pixels.When the pixels are selected by the scanning line,the TFT is in a conductivity status,and signals can be written into each pixel from Data line.The signal delay in the scanning line causes great impact to the quality of the screen image,and therefore,low resisto scanning line should be used.