electronic displays explained hitachi europe ltd
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CRT Advantages
Naturally suited to analogue interfaceNative interface is digital (eg. DVI)
Mature technology; cheapMaturing
technology; cost falling
Support multiple resolutions equally wellFixed inherent resolution
Not pixel-based, no problemMissing pixels
Very high (small area) peak brightness possible; gives "sparkle" and "life" to movies/video/photos
Peak brightness limited;
photos look "flat"
Usually portray motion wellMotion-blur
Good black (quality monitor, adjusted)Poor black images
Consistent image irrespective of viewing angle
Contrast/colour change with angle
CRTLCD
LCD Structure (2)
Commonelectrode
Color Filter
TFT ONOFF
IPS ( In Plane Switching )
Back Light
ONOFF
Color Filter
LiquidCrystal
TFTPolarizer
Electricfield Common
electrode
LiquidCrystal
Polarizer
Pixelelectrode
TN
LCD Advantages
Inherently flicker (although peoples sensitivity varies)
No flicker
Poor text contrast (bandwidth limited)Excellent text contrast
Strong bright areas can cause other regions of the picture to dim
Consistent tonal scale
Tend to suffer from geometric distortions, which may be picture (brightness) dependent, and worsen with age
Perfect image geometry
Limited sharpness; tend to blur more at high brightness, and with age
Perfectly sharp
High power (c.150W)Low power (c.20W)
HeavyLightweight
BulkyCompact
CRTLCD
Colour Reproduction
40%40% 45%45% 50%50% 55%55% 60%60% 65%65% 70%70%28%28%
30%30%
32%32%
34%34%
36%36%
38%38%
40%40%
42%42%
44%44%
Better Display Quality
◇
2001
2002
2003
2004
2006
:Notebook PC:Monitor:TV:Mobile Phone: Automotive
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●
▲
■
■ ◇
◇
Tra
nsm
ittan
ce
Color saturation
GAMMA SHIFT PERFORMANCE
NORMAL TFT
Angle
0
0.2
0.4
0.6
0.8
1
0 100 200
-80
-60
-45
-30
-10
0
10
30
45
60
80
Brightness
Grey Level IPS
0
0.2
0.4
0.6
0.8
1
0 100 200
-80
-60
-45
-30
-10
0
10
30
45
60
80
Grey Level
Brightness
IPS TFT
Angle
Half Contrast AngleDefinition:Viewing angle ranges into half of Contrast Ratio(CR) (°)Measuring Condition:Right and left(H),Upper and lower(V) (127G/64G:Gray Scale)
IPS
0%
20%
40%
60%
80%
100%
120%
-80 -60 -40 -20 0 20 40 60 80
Viewing Angle (°)
CR
H
V
>160°
Normal TFT
H
V
59°
0%
20%
40%
60%
80%
100%
120%
CR
-80 -60 -40 -20 0 20 40 60 80
Viewing Angle (°)
LCD Black Level - Horizontal
Brightness is set at 500cd/㎡
Bla
ck L
evel
(cd
/㎡)
Viewing angle (deg)
IPS
Normal TFT
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-50 -40 -30 -20 -10 0 10 20 30 40 50
LCD Black Level - VerticalB
lack
Lev
el (
cd/㎡
)
Viewing angle (deg)
IPS
Normal TFT
Brightness is set at 500cd/㎡
0.0
0.5
1.0
1.5
2.0
2.5
3.0
-50 -40 -30 -20 -10 0 10 20 30 40 50
IPS Display Improvements
(2004~Now)Next GenerationNext Generation
Target(1998~2002) (2002~2004)
Transmittance(a.u.)
新製品
100
1400
New Optical design/New alignment
New LCD material/ New driving method
Improved moving picture(10→8ms)
180
Further superiorityFurther superiority
130 155
350 630 900Contrast
LCD Performance
IPS Normal TFT
Best point is 10
Transmittance(Brightness or Low Power)
Shift Ratio
0
2
4
6
8
10γ
Front DirectionBlack Level
All DirectionBlack Level
ResponseTime(All gray scale)
(IPS-Pro+Super Impulse)
Color Saturation
Half Contrast Ratio
Motion Picture Color shift&
Color Tracking