Transcript LCD Monitors

LCD Monitors
IS 311 Group Presentation
Topics to be covered
• Beatrice - CRT & LCD Monitor History
• Sici - LCDs Advantages & Disadvantages
• Gil - Current LCDs
• Jerry - Future Trends
• Julio - Buyer’s Guide
CRT & LCD Monitor History
How it all started
Monitor Overview
• The most-used output device on a computer.
• Most desktop displays use a cathode ray tube
(CRT).
• Laptops use liquid crystal display (LCD), lightemitting diode (LED), and gas plasma or other
image projection technology.
• Monitors using LCD technologies are beginning to
replace CRT.
LCD History
• Liquid crystals were first discovered in 1888 by
Austrian botanist Friedrich Reinitzer.
• Melt cholesterol-like substance.
• When cooled, the liquid turned blue before finally
crystallizing.
• RCA made the first experimental LCD in (1968).
• Manufacturers have been developing creative
variations and improvements since on LCDs.
What is Being Used Today?
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The most popular display today remains CRT.
It has been available for more than 70 years.
CRTs:
1. Vivid colors and detailed images and text.
2. Cost less than LCD monitors.
3. Continue to evolve.
LCD Market Trend
• Market for flat screen LCDs grew rapidly during
the ‘90s.
• Huge success of the laptop computer.
• It has still been slow in matching the market share
of the CRT.
• Color LCDs hit the market in the early ‘90s.
• Has only now become popular enough for vendors
to mass-produce.
From CRT to LCD
• CRT
– Bulky, heavy, use vacuum tube
technology.
– Using technology that was
developed in the 19th century.
• LCD
– First LCD laptop monitors were
very small due to manufacturing
costs.
– Light, sleek, energy-efficient,
have sharp picture.
How Monitors Work
• Most use a cathode-ray tube as a
display device.
• CRT: Glass tube that is narrow at
one end and opens to a flat screen
at the other end.
• Narrow end contains electron
guns.
– Single gun for monochrome and
three guns for color.
– Display screen is covered with tiny
phosphor dots that emit light when
struck by the electron gun.
Monitor Classifications
• Monochrome: Display two colors, one for the
background and one for the foreground.
• Gray-Scale: A special type of monochrome monitor
capable of displaying different shades of gray.
• Color: Can display anywhere from 16 to over 1 million
different colors. Sometimes called RGB monitors.
Monitor Quality and Resolution
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•
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Quality:
Manufacturers describe quality by dot pitch.
Smaller dot pitches mean pixels are closely spaced
which will yield a sharper image.
Most monitors have dot pitches that range from
0.22mm to 0.39mm.
Resolution:
Indicates how densely packed the pixels are.
Most modern monitors can display 1024x768 pixels.
High end models can display 1280x1024.
LCD Technology
• Used for displays in notebooks, small computers,
pagers, phones and other instruments.
• Uses a combination of fluorescent-based backlight,
color filters, transistors, and liquid crystal to create
and illuminate images.
• Until recently, was only used on notebook computers
and other portable devices.
• In 1997, manufactures began to offer full size LCD
monitors as alternatives to CRT monitors.
IBM Advances in
Display Technology
• In 1981, IBM introduced the Color Graphics Adapter
(CGA) display, able to display 4 colors and max
resolution of 320x200.
• In 1984, Enhanced Graphics Adapter (EGA) display,
able to display 16 colors and resolution of 640x350.
IBM Advances in Display
Technology (cont.)
• In 1987, Video Graphics Array (VGA) display.
– Most computers today support the VGA standard.
• In 1990, Extended Graphics Array (XGA) display,
capable of resolutions 800x600 in true color ( 16.8
million colors) and 1024x768 in 65,536 colors.
Pre-IBM
Apple II
• Released in 1977
• First true “personal computer”
• Based on the Apple I design
with some additions
– Plastic case
– Able to display color graphics
• Able to display 6 colors at
280x192 resolution.
Apple II Control Panel
Pre-IBM (cont.)
TRS-80
• Developed in late 1970s
by Radio Shack.
• First product in store
history to fetch more than
$500.
• Monitor was basically an
RCA TV with the tuner
removed.
• Became a direct
competitor to the Apple
computer.
TRS-80
Heath Desktop
• One of the first
computers designed as
complete desktop
machines.
• Included monitor,
floppy disks and
keyboard.
• Was eventually bought
by Zenith.
IBM PC-1981
• IBM’s 5150 model
introduced in 1981.
• The PC featured a 5MHz Intel processor,
18K of memory and
an optional color
monitor.
• Starting price: $1,565
Windows Screen Shots Throughout Time:
MS-DOS
Windows 3.1
Windows Screen Shots Throughout Time:
Windows 98
Windows 2K
Windows Screen Shots Throughout Time:
Windows XP
Advantages of LCDs
• Physical Size
– Compact and Lightweight
– Space saving
– Can be mounted on a wall or panel
Advantages of LCDs
• Display Size
– Available at comparable in screen size as traditional
CRT
– Shown on the next slide, a 12.1" LCD display (left) has
only a slightly smaller viewing area than a typical 14"
CRT monitor. Newer, larger LCD monitors are also
appearing that have 15", 17", and even larger screen
sizes that are comparable to the largest CRT monitors.
(One thing to note is that LCD monitors are typically
sized by their actual viewable diagonal measurement,
but CRTs typically are not.)
Advantages of LCDs
Advantages of LCDs
• Power Consumption and Radiation Emission
– Consume less energy and more durable
• A typical CRT losses approximately 50% of its brightness
after 10,000 hours. An LCD bulb will maintain its brightness
anywhere from 25,000 to 50,000 hours.
• LCD consumes fewer watts than a CRT. LCD will use an
average 30 watts compared to 120 watts for the CRT.
• Can reduce electric bill by 40-85%.
• Uses a combination of fluorescent-based backlight, color
filters, transistors, and liquid crystal to create and illuminate
images. It blocks light rather emit light
Advantages of LCDs
• Power Consumption and Radiation Emission
– Doest not emit Radiation
– Not subject to Electromagnetic Interference
Advantages of LCDs
• Viewing
– Cause less eyestrain
– Does not flicker or glare
(Source: Dailey News – June 2, 2002, TouchScreens.com, unicomplabs.com,
TheVisualLink.com)
Advantages of CRT
• Color
– Most are capable of displaying unlimited
colors.
• Resolution
– Multiple video Resolutions.
Advantages of CRT
• Response Time
– Faster response time. Critical to people who
watch videos or play games on their PC’s.
– The fastest LCD’s offer a response time of
about 25 milliseconds as apposed to CRT’s that
have a response time of about 13 milliseconds.
Advantages of CRT
• Viewing Angle
– Look @ a very wide angle
(Source: PCWorld.com, TouchScreens.com)
Disadvantages of LCDs
• Resolution
• Displays Native Resolutions (Resolution that it
displays best)
• Viewing Angle
• Smaller, needed to be viewed more directly from
the front.
• From the side the images on an LCD screen can
seem to disappear, or invert colors.
• Newer displays that are coming out have a wider
viewing angle so this is not as much of an issue as it
has been in the past.
Disadvantages of LCDs
• Price
– Upfront cost it is more costly but long-term
cost but will conserve energy in the long run.
– The energy savings may not be much for an
individual use, but for a corporate office where
50 displays or more are in use, the energy
savings might be more of an issue.
Disadvantages of LCDs
• Installation
– Need a plug interface to connect to the
computer.
– Some require a special digital plug-interface in
order to work .
– Problem: is that this plug is not available on
most computers, so another video card or
adapter must be purchased to plug these LCD
monitors into the computer.
Disadvantages of LCDs
• Response Time
– It is much slower. The delay can cause a
ghosting effect on images it displays.
(Source: TechRepublic.com, PCWorld.com, TouchScreens.com)
Disadvantages of CRTs
• Physical size
– Takes more desktop space.
(Source: TechRepublic.com)
Disadvantages of CRTs
• Power Consumption and Radiation Emission
– Consumes more energy
– Emits harmful radiation. The metal shield behind the
glass of your monitor protects your body from a flood
of radiation.
– It holds a dangerous electrical charge even after turned
off and can last up to several years and be hazardous
and even deadly to anyone who opens a CRT monitor
casing.
– Know to cause fires due to electrical malfunctions and
excessive heat if the ventilation holes are accidentally
covered up.
(Source: TechRepublic.com)
CURRENT LCD’s
Current Technology and Trends
Business Aspect
1. Reasons for a sensitive market:
I. Price sensitive demand – As price drops
slightly sales go up sharply.
II. Long time for production facilities to
form.
Recent History
• 1999 – Very high demand for LCD
• 2000 – Crash of computer market causes
surplus.
• Prices are slashed.
Average 17” LCD Monitor Street price
Quarter
Average Price
1Q 2001
$1,148
2Q 2001
$1,003
3Q 2001
$887
4Q 2001
$781
1Q 2002
$773
2Q 2002
$757
3Q 2002
$735
4Q 2002
$676
Technology Aspect
• 1. Display addressing.
• 2. Analog VS digital signal handling.
• 3. Display Uniformity and Viewing Angle .
Active VS. Passive Display
Active Display
Passive Display
TFT (Thin Film Transistor)
Analog VS Digital signal handling
• On most graphic card signal goes through
DAC (digital to analog converter) to
convert to Analog signal.
• LCD must convert the signal back to digital
to determine which pixel to light.
• If conversion has error the result is "pixel
jitter", in which the image seems to
shimmer or move.
Improved Signal Handling
• 1. DVI (digital video interface) standard
was adopted.
• i. DVI handles both analog and digital
signals with separate connectors
• 2. controlling circuitry became substantially
better in a very short time.
Display Uniformity
Backlight
• Early LCD backlight wasn’t uniform and
“hot spots” were created.
• Display manufacturers developed more
sophisticated diffusing materials.
Viewing Angles
• Improving Viewing angels can be done by
changing cell design.
• Three different cell designs.
1. Vertical alignment (VA).
2. In-plane switching (IPS).
3. Multi-domain.
LCD Future Trends
LCD Future Trends
• Short & Long Term Prices
• 3 Important Ergonomic Features
• LCD Monitor Quality
• New Technologies
LCD Future Trends
• Lower LCD Prices in the Short Term
– The Dock Works Strike
– The Slow Economy
– More Factories Online
LCD Future Trends
• Lower Prices in the Long-Term
– Calculators, CRTs, VCRs and DVD Players
were all very expensive at first
– They now sell at lower prices because of the
laws of supply and demand
– What do they have in common with LCDs?
– The are all electronic devices
– So if the laws of supply and demand continue to
apply, LCDs will sell for less in the long-term
LCD Future Trends
• Lower Prices in Long-Term (continued)
– Example of an LCD going down in price
• IBMs T220 LCD monitor cost about
$50,000 when it first came out
• Oct 2001 – it costs: $22,000
• Dec 2001 – it costs: $15,999
• May 2002 – it costs: $8,400 (T221)
LCD Future Trends
• Three Important Ergonomic Features
– Large Viewing Angles
• All LCDs approaching 170° both horizontal & vertical
– Minimal Reflection and Glare
• Sharp’s AGLR screen coating which forms a quarterwavelength filter that cancels reflection rather than
diffusing it as other do.
– Thin Bezels
• When working with multiple monitors, your eyes don’t
jump past wide gaps – thus less eye strain
LCD Future Trends
A workstation where all three of
these ergonomic features are useful
LCD Future Trends
• LCD Monitor Quality
– Backlights
• The only thing that can wear out
• There are more LCDs with 50,000 hour life
spans
– Zero-Voltage Black
• lessens impact of non-functioning subpixals
LCD Future Trends
• New Technologies
– On-Glass Circuitry unveiled Oct. 22, 2002
• The new screens use Sharp’s CGS
(continuous grain silicon)
• Microprocessor circuitry applied directly on
the glass, enabling it to function like a
computer
• Produces ultra fine resolutions
LCD Future Trends
• New Technologies (continued)
– ThinCRTs from Candescent Technologies
• quarter-inch thin form factor: a "thin CRT."
• Thousands of emitters instead of a single
large cathode tube
• Has the best of both CRTs and LCDs
LCD Future Trends
• ThinCRT from Candescent Technologies
Buyer’s Guide To LCD Monitors
• What to consider when buying a LCD
monitor
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What applications are going to be used
How much room you have on your desk
How much space you need on a virtual desktop
How much you want to spend
Buyer’s Guide To LCD Monitors
• Key features or things to look for when
deciding what to buy and how much to
spend
– Native Resolution
• LCD uses a matrix of cells to display its
image, causing it to have a fixed or native
resolution at which the display looks best
Buyer’s Guide To LCD Monitors
• Viewing angles
– indicates how you can move to the sides
or below the center of the screen before
image is being displayed
– an angle of 160 degrees is recommended
• Dot Pitch
– another indicator of image quality
– the smaller the better; more expensive
Buyer’s Guide To LCD Monitors
• Contrast ratio
– is the difference in light intensity between the
brightest white and the darkest black that an
LCD can produce
– helps determine how rich the color will be in
on-screen images
– recommend a contrast ratio of 300:1 or better
Buyer’s Guide To LCD Monitors
• Digital vs. Analog
– if you have a graphics card with a digital videoout, choose LCD that has digital input
– image will be clearer because it won’t have to
convert from analog to digital and back and
forth
Buyer’s Guide To LCD Monitors
• Prices
– $200 - $500 range: panel size – 15 inches;
native resolution – 120/100 to 140/120 degrees;
contrast ratio – 200:1 to 300:1
– $500 - $800: panel size – 15 to 17 inches;
native resolution – 120/100 to 140/120 degrees;
contrast ratio – 300:1 to 350:1
– $800 and up: panel size – 17 to 19 inches;
native resolution – 150/140 to 170/170 degrees;
contrast ratio – 300:1 to 400:1
Buyer’s Guide To LCD Monitors
• Buying Tips
– Stick to 15 inch monitors
• balances screen size and price together well
• Cheapest
– Look for a wide viewing angle
• good for making presentations and working with
partners
• indicates a higher quality panel with better
brightness and color effectiveness
• less tendency to leave trails on screen
Buyer’s Guide To LCD Monitors
• Buying Tips
– Try before you buy
• actually looking at your desired monitor is
always best
• do not buy online or by mail unless the seller
has a return policy
Buyer’s Guide To LCD Monitors
• Comparison with CRT buying tips
– Stick with a 17 inch monitor
• is big enough and doesn’t take up too much
space
• is cheaper
• if you work with allot of graphics and image
editing, go with the $300-$400 19 inch
CRT’s
Buyer’s Guide To LCD Monitors
• Comparison with CRT buying tips
– Need to consider power cost
• uses more power than LCD monitors
• can find low power CRT monitors that have a
TCO’99 seal
– Do not throw away CRT monitors
• contain large amounts of toxins and lead that destroy
soil and water
• Recycle
Buyer’s Guide To LCD Monitors
• Where To Buy
– Electronic stores (reasonable prices)
• Fry’s Electronics, Circuit City, Compaq,
Best Buy
– Websites – low prices, but can’t see what
you are buying
• tomshardware.bizrate.com
• www.dealtime.com
• tigerdirect.com
Buyer’s Guide To LCD Monitors
• Conclusion
– Prices have been falling over the past two years
• more affordable for consumers
– Key features and buying tips mentioned should
lead consumers in purchasing the right LCD
monitor for the lowest price
Conclusion
Q&A