液晶显示器驱动IC原理和介绍.pdf

Source Driver
Source Driver
from Notebook
LVDS
from Desktop PC
Or
LCD Controller (Panel Link
Or ADC)
LCD Control ASIC
Reference generator
WFP2373 Gate Driver
258
VEE Vss
Output Stage
To STN Common
LP V1~V4
Data Latch Output Stage
To STN segme
STN LCD Driving waveform
Column 1 Column 2
Common Signal
Line1 Line2 Line3 Column 1 Column 2
Segment Driver
Common Driver
STN LCD Driver Block
STN Common Driver
STN Segment Driver
EI/O
Shift Register
EO/I
EI/O
Shift Register
EO/I
Dcl
Dcl
k
k
D0~D8
Data Latch
F
0ቤተ መጻሕፍቲ ባይዱ
-F D -D
F+D D -D
-(F+D)
IAPT
F+D F
D Common
2D 0 Segement
F+D
LCD pixel
D -D
0 F+D
F-D
-(F+D)
Color on STN LCD - FRC
Frame rate control
=
4/4
=
3/4
=
2/4
=
1/4
=
0/4
Time
Color on STN LCD - PWM
CAP1+ CAP1CAP2+ CAP2CAP3+ COUT
Power Supply Circuit
SEG0~SEG131
SEG Drivers
Display data latch circuit
Display data RAM 132x65
COM0~COM63
COM Drivers
Com Output Status select circuit
I. 液晶 驅動 原 理 介紹
液晶 驅動 原 理
Field OFF
Field ON
Twist Nematic (TN)
Field OFF
Field ON
TN & STN V-T Transfer Curve
STN
T
DV2
TN
V
DV1
PS: TN more suitable for more gray levels STN for black & white
A pixel
M Common
A B
A pixel
B pixel
B pixel
Horizontal Cross talk of STN LCDs
A
SEG
L Line
A B
Common
Pixel Waveform
B L
CMO S
Epson SED1565 Block Diagram
Vss
VDD V1 V2 V3 V4
WFP2373 258 Gate Driver
1024x768 260K LCD panel
TFT LCD Market Forecast
45 40 35 30 25 20 15 10 5 0
2000
2001
LCD 靜態驅動 法
Vsig
Vc
ON Vsig Vc Vs Vc - Vs
Vs LC Cell
OFF
ON
II. STN LCD Driver introduction
Mobile Phone Market Forecast
Mobile Phone 600
Msets
500
400
300
200
100
0 2000 2001 2002 2003
Pulse Width Modulation
Segment Common
Pixel
Vertical Cross talk of STN LCDs
M Common
A B
A pixel
B A
B pixel
Reduce Vertical Crosstalk of STN LCDs
M Common
A B
F+D
+D -D F-D +D -D F+D
+D -D
Segment Signal
Limitation on STN LCD Resolution
ON =
2
2
(F+D) + (N-1)D
N
OFF =
2
2
(F-D) + (N-1)D
N
ON SR =
OFF
F =N
D
SR =
N +1 N -1
N
Bias
STN Mono STN Color LTPS Color
STN PDA Market Forecast
PDA
12000
Ksets
10000
8000
6000
4000
2000
0 2000 2001 2002 2003
STN Mono STN Color
STN LCD Driver Introduction
Line address circuit Display Timing generation circuit
Page address circuit I/O buffer
Column address circuit
OSC
Bus holder
Command decoder
Status
MPU interface
Epson Voltage Reference Block
Vdd
Vout (from charge pump)
Vdd V1
V2 To Segment&
V3
Common
V4
V5
Epson OSC Block
V= VTn + VTp
Power for OSC
VI. TFT LCD Block Diagram
液晶顯示器驅動IC原理和介紹
主講人 : 黃雲朋
Content
I. 液晶 驅動 原 理 介紹 II. STN LCD Driver Introduction III. STN Case Study VI. TFT LCD Driver Introduction V. TFT Driver IC Consideration
SR
2
1:2
2.23
4
1:3
1.73
8
1:4
1.45
16
1:5
1.29
32
1:7
1.2
64
1:9
1.15
100
1:11
1.11
128
1:12
1.09
200
1:15
1.08
240
1:16
1.06
400
1:17
1.06
1.3
1.2
1.1
1.
0
100
200
STN LCD Driving Method
APT