OSE-6820
Lecture 11:
Introduction to Plasma Display
Prof. Shin-Tson Wu
College of Optics & Photonics
University of Central Florida
Email: swu@mail.ucf.edu
Acknowledgment: Dr. Kung-Lang Chen of CPT
UCF
College of Optics & Photonics
CREOL & FPCE
Photonics & Display Group1
Outline
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What is Plasma?
PDP history
Applications of PDP
Discharge physics of PDP
Process technology of PDP
Driving technology of PDP
Electronics system of PDP
Performance improvement
PDP vs. LCD & OLED
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The fourth state of matter
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PDP History
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Early DC PDP TV at Bell System
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The early AC PDP in UI: 1964
The monochrome plasma
video display was coinvented in 1964 at the
University of Illinois at
Urbana-Champaign by
Profs. Donald Bitzer, H.
Gene Slottow, and
graduate student Robert
Willson for the PLATO
Computer System.
In 2007, SID established SlottowOwaki Prize, which is awarded for
outstanding contributions to the
education and training of students
and professionals in the field of
information display.
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Recent Advances of PDP
Samsung’s 102” PDP
Pioneer 60” PDP
Resolution: 1920x1080
Contrast ratio: 20,000:1
Brightness: 1000 Nits
Surface reflection: 7.5%
Large pixel size; burn-in?
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Applications of PDP
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Gas Discharge Physics
MgO
95% Ne + 5% Xe
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Gas Volume Reaction
Main mechanism: 95% Ne + 5% Xe
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Ne-Xe Energy Levels
UV for excitation, near IR for inspection
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Luminescence Mechanism
Triode Electrodes: Surface discharge between top
2 electrodes (not phosphors) →Longer lifetime
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Total Efficiency of PDP
95% Ne and 5% Xe
Higher Xe → Higher V
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Color PDP Structure
Gas discharge→ UV → Phosphors →RGB lights
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PDP: Cross-Section
Scan Electrode
Sustain Electrode
Front Plate
Plasma
UV Light
Barrier Rib
Visible Light
Back Plate
Phosphor (R)
Phosphor (G)
Data Electrode
Phosphor (B)
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Color Formation
Yellow
R = 100%
G = 100%
B = 0%
White
R = 100%
G = 100%
B = 100%
Purple
R = 70%
G = 30%
B = 80%
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Fabrication Process
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AC-PDP Structure
ITO
(Ag; high conductivity)
MgO meets these 3 conditions
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ITO Process
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Bus Electrode Process
(Photo-polymer+
Ag particles)
(Beta printing: Main stream approach)
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Dielectric Process
(Steel net)
(Very thin dielectric)
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MgO Protection Layer
(Or electron beam:
low I, high V)
(Ion beam
High I)
Evaporation method
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Address Electrode Process
(Ag particles/binder)
Bottom substrate
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Dielectric Process
Mesh: tension change after each use
Resolution degradation
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Rib Process: Early Days
Rib height~150 μm:
Each layer is ~15 μm; Needs 10 times
Not practical!
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New Rib Process
(150 μm)
New methods: Etching, printing, ..
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Phosphor Process
New methods: Dispensing, ..
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Sealing Process
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Panel Assembly
Stainless steel clips: handled by robots
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Sealing & Exhausting
Ne+Xe
Pressure: 450-500 torrs <1 ATM
Thermal sealing
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Block Diagram of PDP TV Set
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Scanning Technique
HDTV: n=1080
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DC & AC Discharges
Capacitor
Simple grayscale control
But resistors:
3M resolution → 6M contacts
No resistors
Mainstream approach:
Grayscale: # of pulses
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Memory Effect: AC-PDP
If the 1st writing pulse is on,
the remaining 3 are on
If the 1st writing pulse is off,
the remaining 3 are off.
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Driving Waveforms
Set-up: To erase memory; Address: determine which one ON
These 3 periods repeat.
Driving voltage ~ ±200 V for 95% N + 5% Xe
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Gray Levels
R and G: Kept at same width
B: varies from 1, 2, 4, 8, 16, 32, 64, 128
Total gray levels: 256
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Integration of weighted gray-level
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PDP vs. LCD
Plasma
Emissive
LCD
Non-emissive
Light
Light
Polarizer
Front
Plate
（R）
Electrode
（G）
Visible
Light
（B）
Color
Filter
Electrodes
UV
Rear
Plate
Electrode
Phosphors
LCD
Shutter
Glass
Plates
Polarizer
Backlight
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Contrast Ratio
Bright ambient (600 Lux)
Dark Ambient (<1 lux)
LCD
~800:1
~2000:1
~80:1
2000:1
PDP
Surface reflection: LCD<2%; PDP~7.5%
Reflection reduction: Film filter
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PDP: Cost Structure
Materials: 52%, Processing: 37%, Filter: 11%
PDP cost: 70% driver & 30% panel
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TV Market Forecast
DisplaySearch: Q4, 2008
2009: LCD/PDP/CRT~73/15/12
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Efficacy Improvement: Example 1
KW Whang et al, SID’05, p. 1130
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Ex. 2: Volume vs. Surface Discharge
• TFCS: thick film ceramic sheet
T. Sato, et al., Proc. IDW, 1761 (2006)
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Example 3: Phosphor Deposition
TRANSMISSIVE
REFLECTIVE
HYBRID
Fluorescent lamps use the hybrid type
Homework
1. Read the following article and then
compare/analyze the pros and cons
between PDP, LED-lit LCD, and OLED
TVs.
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Recently, improvements in LCD TV has given substantial advantages to the consumer. One improvement is
in the area of LED backlighting. This improvement alone yielded enhancement in image quality with respect
to contrast and color gamut. Additional benefits of LED backlight is in the reduction in power consumption
and reduction in thickness of TV. Plasma TV has been claiming higher contrast than LCD TV in dark
environment. With the use of LED backlight with image adaptive dimming, this advantage is gradually being
lost. The color gamut of RGB-LED- lit LCD TV is the highest of all types of TV including OLED TV. OLED
panels are supposed to be thin because there is no backlight involved. The 11" OLED TV on the market is
cautiously quoted to be 3mm at the "thinnest point of TV". Here is a quote from Samsung that appeared in
December of 2008- "Even if the OLED panel is only 3mm thick, the TV will need to be 25mm or so – we are
getting close to that with LCD technology." (In fact the thickness of recent models of LCD TVs is likely to
be far less than 25 mm). This is true for LED-lit LCD TV as long as the backlight is fabricated in the 'edge-lit'
mode. But the edge-lit mode will not be giving the advantage of high color gamut. In the 'direct-lit' mode of
LED backlight, OLED TV has the advantage of slimness but has to face a stiff competition in power
consumption because of the 'image adaptive dimming' employed in 'direct-lit' mode. Having said this. the
competition in power consumption that OLED TV has to face is not that simple even with 'edge-lit' mode of
LCD TV because of the impressive efficacy of white LEDs employed in 'edge-lit' mode. Plasma TV will also
face the stiff competition in terms of power consumption.
In December of 2008, 11" OLED TV by Sony consumed a power of around 45W. Recent development on 46"
LCD TV employing 'image adaptive dimming‘ has demonstrated power consumption of 50W. So with the
introduction of LED-lit LCD TV, the power consumption has been substantially dropping. 'White
pixel‘ approach is another route available for both OLED technology and LCD technology to decrease the
power further. What is significant here is that OLED technology has the inherent advantage of the 'absence'
of backlight. Under this condition one would normally expect a significant drop in power consumption and low
price. But it is not happening in the real world. (With 'but' and 'if' condition an extrapolation of OLED power
and life can be arrived at). Any new technology will take time to reveal its full potential in the market place.
OLED technology has the potential of low power consumption through its well demonstrated 'harvesting of
triplet states'. The materials developed in the phosphorescent OLED family have demonstrated even
200,000 hours at lab level except for blue-emitting material. Blue is till a problem even at lab level. In terms of
low cost of manufacturing, solution-based processes and 'roll-to-roll' manufacturing processes hold the key in
OLED technology. None of
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these are validated at the commercial product level in mass manufacturing. Substantial generation of learning
curve in large area OLED mass manufacturing will start with the introduction of >32" OLED TV. Establishing
infrastructure similar to LCD is capital intensive. In addition to all these barriers, LED backlight is imposing
another barrier.
Both OLED and LED have potential application in TV and Lighting. The R&D and manufacturing activity in LED
is far higher than OLED. Big giants like, GE, Osram, Philips are taking the lead in LED lighting. The price of LED
is coming down substantially. Efforts are underway to introduce 6" wafer in mass manufacturing and low cost
substrates including glass are being experimented. Low power white LEDs in mass manufacturing have shown
efficacy as high as 150 lm/w and lab level demonstration for white has revealed 247 lm/w. Medium power white
LEDs have shown mass manufacturing level efficacy of 110 lm/w. What is important is that the efficacy of LEDs
quoted is in higher range of brightness compared to OLED. OLEDs have also demonstrated 100 lm/w at lab
level (1000 nits) but not yet at manufacturing level. Correlated color temperature for white is another question
that needs to be looked in to precisely for comparison. It appears that LED efficacies are not saturating and is
galloping. This is likely to keep pressure on OLED TV and plasma TV.
Samsung, AUO, ChiMei, LG Display, Sony, Sharp, Panasonic are all in LCD/LCD TV activity and are exploiting
LED backlight for low power consumption and enhancement in image quality. Sony and Samsung are leading in
OLED manufacturing with Sony leading in OLED TV but Samsung delaying the introduction of large size OLED
TV. All other things being equal (with LCD), theoretically OLED technology should be advantageous both from
the price angle and power angle. This advantage is delayed due to various factors and one of the recent factors
is the pressure from LED backlight.
One area that OLED holds the key is in its potential to have 'roll-to-roll‘ manufacturing resulting in a dominant
advantage of flexibility, slimness and low weight. In this aspect there will not be any threat from LCD TV or
plasma TV. But in the next 10 years this is not likely to happen.
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