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16.2 Flat-Panel Displays

CRT monitors have been the dominant PC
display technology since PCs were invented, but that is beginning to
change. Flat-panel displays (FPDs) are coming on fast. CRTs still
outsell FPDs in retail channels. But in the distribution
channelthose bundled with new PCsFPDs exceeded CRTs in
popularity by late 2002. Considering the high cost and relatively
poor image quality of entry-level FPDsand bundled FPDs are
nearly always entry-level modelswe are amazed that FPDs have
become so popular so quickly.

FPDs are now common on high-end corporate systems, although FPDs are
unlikely to displace CRTs on mainstream systems anytime soon. The
cost and other advantages of CRTs ensure that
they'll remain available for years to come, but the
emphasis is definitely shifting to FPDs. During 2003 and 2004, we
expect this trend to continue and indeed accelerate.

16.2.1 Flat-Panel Display Characteristics

Here
are the important characteristics of FPDs:

FPD panels are available in two broad types:

Passive-matrix panels generally use
Super Twisted Nematic (STN)
technology. These panels are commonly used on notebook systems, where
they provide adequate display quality at a reasonably low price. Only
the least-expensive desktop FPDs use passive-matrix technology, which
should be avoided for its low display quality.

Active-matrix panels generally use
Thin Film Transistor (TFT)
technology, and are superior to passive-matrix in every respect
except price. Most entry-level FPDs and all premium FPDs use TFT
technology, which we consider the minimum acceptable. TFT provides
usable viewing angles of up to 170 degrees horizontally and
vertically. TFT panels are made in what amounts to good, better, and
best grades, with higher grades providing wider viewing angles and
less color shift as the viewing angle moves off-axis. As of July
2003, the best TFT panels use In-Plane Switching
(IPS) or Multi-Domain Vertical
Alignment (MDVA or
MVA), which dramatically improve image quality
when properly implemented. Unfortunately, the converse is not
necessarily true. That an FPD uses IPS or MDVA does not guarantee a
high-quality image, and unfortunately some very low-quality IPS FPDs
are available. We expect IPS and MDVA technology to become a standard
FPD technology later in 2003 and into 2004, with individual
implementations, then as now, varying greatly in display quality.

You will see references to Enhanced Thin Film Transistor technology. In fact, this is not a separate technology, but merely a marketing term used by display makers to differentiate quality levels among TFT panels.

Unlike
CRT monitors, which have a maximum resolution but can easily be run
at lower resolutions, FPDs are designed to operate at one resolution,
called the native resolution. You can run an FPD
at lower than native resolution, but that results in either the image
occupying only part of the screen at full image quality, or, via
pixel extrapolation, the image occupying the full screen area but
with greatly reduced image quality.

FPDs are available in analog-only, digital/analog hybrid, and
digital-only interfaces. Using an analog interface requires
converting the video signal from digital to analog inside the PC and
then from analog to digital inside the monitor, which reduces image
quality, particularly at higher resolutions. Synchronization problems
occur frequently with analog interfaces, and can cause various
undesirable display problems. Finally, analog interfaces are
inherently noisier than digital interfaces, which causes subtle
variations in display quality that can be quite disconcerting. The
following section presents FPD interfaces in more detail.

Whereas
CRT monitors require high vertical refresh rates to ensure stable
images, FPDs, because of their differing display technology, can use
much lower refresh rates. For example, at 1280 x 1024
resolution on a CRT monitor, you'll probably want to
use an 85 Hz or higher refresh rate for good image quality. At the
same resolution on an FPD, 60 Hz is a perfectly adequate refresh
rate. In fact, on FPDs, a lower refresh rate often provides a better
image than a higher refresh rate.

Unlike CRT monitors, whose phosphor-based
pixels respond essentially instantaneously to the electron beam, FPD
panels use transistors, which require time to turn on or turn off.
That means there is a measurable lag between when a transistor is
switched on or off and when the associated pixel changes to the
proper state. That lag, called rise time for
when the transistor is switched on and fall time
for when it is switched off, results in a corresponding lag in image
display. On slow FPDs, even dragging a window can show noticeable
smearing or stuttering as you move the image to its new location.
Even the fastest current FPDs are too slow for the most demanding
video, such as 3D games. The best FPDs have rise and fall times on
the close order of 15 milliseconds (ms). Good FPDs have rise/fall
times of about 30 ms. Inexpensive FPDs may have rise/fall times of 50
ms or more. We consider a rise/fall time of 30 ms acceptable for
general use, but we're much happier with a rise/fall
time of 15 ms.

16.2.2 Flat-Panel Interfaces

CRTs
are an analog technology. The video data inside the PC is manipulated
digitally, converted to an analog signal by the graphics adapter, and
delivered to the CRT monitor, which can use the analog signal
directly. Except for a few high-end models that can use discrete RGB
connectors, CRT monitors universally use the standard 15-pin analog
VGA connector.

Conversely, FPDs are inherently a digital technology. Although most
FPDs can accept both analog and digital signals, using an analog
signal requires converting that signal to digital before the FPD can
display it. This double conversiondigital-to-analog inside the
PC followed by analog-to-digital inside the FPDreduces image
quality and increases complexity and costs, but in a world of analog
video adapters, FPD makers had no choice but to design their displays
to accept analog inputs.

It would obviously be simpler to avoid the
digital-to-analog-to-digital conversion and drive the FPD directly
with the digital signal generated by the PC, and
that's just what is done with new-generation display
adapters and FPDs. But getting to that point was not simple.

The first efforts to standardize a digital interface for video began
in 1996, but made little progress initially. Early efforts centered
on adapting the well-established Low Voltage Differential
Signaling (LVDS) standard in use for notebook systems to
desktop systems. LVDS could not be used as is because it was designed
for the short cable lengths used in notebook systems rather than the
longer cable lengths required for desktop systems. National
Semiconductor developed a modified LVDS it called FlatLink, and Texas
Instruments developed a competing LVDS-based technology called
FPD-Link, neither of which was compatible with the other and neither
of which was widely adopted. Several other proposed standards also
failed to achieve critical mass, including Compaq's
Digital Flat-Panel (DFP), National Semiconductor's
second-generation OpenLDI, and VESA's
Plug-and-Display. Each of these technologies had some advantages
relative to the others, but none was fully compatible with anything
but itself.

By late 1998 it was clear that none of these technologies had
achieved the market dominance needed to establish a de facto standard
digital video interface. As is often the case, Intel stepped in,
having decided that in its own best interests as well as those of the
industry as a whole, a digital video interface standard had to be
established, and sooner rather than later. Intel formed the Digital
Display Working Group (DDWG), which initially included Compaq,
Fujitsu, Hewlett-Packard, IBM, Intel, NEC, and Silicon Image.

That last name is important because in April 1999 the DDWG
(http://www.ddwg.org) released
the draft Digital Visual Interface
(DVI) specification, which was largely based on
the PanelLink Transition Minimized Differential
Signaling (TMDS) technology developed
by Silicon Image. Note that DVI does not stand for Digital

Video Interface, although that is often
mistakenly assumed. DVI is now effectively the main standard to which
FPDs are designed. Because the earlier proprietary DFP and VESA
Plug-and-Display interfaces are PanelLink-based, DVI-based displays
can use these interfaces with only an adapter cable.

DVI provides 165 MHz of bandwidth per DVI link, and the DVI
specification allows one or two TMDS links, for a combined bandwidth
of 330 MHz. Single-link DVI supports up to 1600 x 1200
resolution at a 60 Hz refresh rate. (Although 60 Hz may seem an
impossibly low refresh rate, particularly at 1600 x 1200
resolution, the characteristics of FPDs mean that lower refresh rates
are quite usable, and in fact the image quality is often superior at
lower refresh rates than at higher ones.)

Dual-link DVI is necessary to achieve higher resolutions, such as
1920 x 1080 (HDTV) and 2048 x 1536. Dual-link
DVI devices use a single clock, which means that the two links remain
synchronized, and bandwidth can be shared between them. The system
uses one or both links transparently, depending on the bandwidth
requirements of the connected display. DVI also implements various
display standards that originated with earlier proprietary protocols,
including standardized protocols that allow the computer, video
adapter, and display to negotiate optimum settings.

DVI defines three types of connectors. The
DVI-Analog (DVI-A)
connector, shown in Figure 16-1, supports only
analog displays. The DVI-Digital
(DVI-D) connector, shown in Figure 16-2, supports only digital displays. The
DVI-Integrated (DVI-I)
connector, shown in Figure 16-3, supports digital
displays, but also maintains backward compatibility with analog
displays, although it does require an adapter that converts the
standard 15-pin VGA analog plug to the DVI-I jack. The connectors are
physically keyed so that a digital display cable fits a DVI-D or
DVI-I connector but not a DVI-A connector, while an analog display
cable fits a DVI-A or DVI-I connector but not a DVI-D connector. This
prevents an analog monitor from being connected to a digital-only
interface or vice versa, which could destroy the monitor, the
interface, or both.

Figure 16-1. DVI-A analog-only connector

Figure 16-2. DVI-D digital-only connector

Figure 16-3. DVI-I hybrid digital/analog connector

The DVI-D and DVI-I connectors define 24 pins for digital
connections, which can support two full TMDS channels. The DVI-I and
DVI-A connectors also define four additional signal pins and a ground
pin that add support for analog video. The DVI-D jack accepts a
12-pin (single-link) or 24-pin (dual-link) DVI plug, both of which
are digital-only plugs. The DVI-I jack accepts those two plugs, and
also accepts the new-style DVI analog plug, which has a protruding
cross-shaped key that prevents it from being inserted in a DVI-D
jack. The DVI-I jack has a corresponding hole that allows the DVI
analog plug to seat. The DVI-A jack accepts only the DVI analog plug.

Of course, the ability of DVI to stream unprotected digital content
is of great concern to the

Motion Picture Association of
America (

MPAA ) and the

Recording Industry Association of America
(

RIAA ). The MPAA and RIAA want every cent they
can suck out of consumers' pockets by means fair or
foul. They are deathly afraid that people will steal their products
rather than pay the inflated prices they demand, and so are willing
to spend whatever it takes to buy enough legislators and judges to
ensure passage and enforcement of such deplorable laws as the
Digital Millennium Copyright Act
(DMCA), the real goal of which is to eliminate
our Fair Use rights under copyright law.

To placate the MPAA, Intel developed the High-Bandwidth
Digital Content Protection (HDCP)
specification, which encrypts all data that travels across the DVI
interface. Data is encrypted before being delivered to the DVI cable,
and then decrypted by the DVI monitor prior to displaying it. A DVI
monitor that does not support HDCP can still display protected
content, but only in a degraded form of sufficiently low quality to
pose no threat of providing an acceptable copy for distribution.

Even the MPAA doesn't really believe HDCP can
prevent commercial piracy. The goal of HDCP is to prevent people from
knocking off a copy of a DVD and giving it to a friend. Casual
copying scares the MPAA and RIAA, particularly because many forms of
it are protected under Fair Use and other provisions of copyright
laws. Our sources tell us that HDCP has already been hacked, so it
probably won't be long until casual HDCP exploits
are commonplace.

16.2.3 FPD Versus CRT

Relative to CRT monitors, FPDs have
the following advantages:

FPDs are, on average, brighter than CRTs. A typical CRT might have
brightness of about 100 candelas/square meter, a unit of measurement
referred to as a nit. (Some monitors are rated
in foot Lamberts (fL), where one fL equals about 3.43 nits.) A
high-quality 15-inch FPD might be rated at 300 nits, three times as
bright as a typical CRT. This brightness disparity decreases a bit in
larger sizes. For example, a high-quality 19-inch FPD might be rated
at 235 nits. CRTs dim as they age, although a brightness control with
enough range at the upper end can often be used to set an old CRT to
near-original brightness. The cold cathode ray
tubes (CCRTs) used to backlight FPDs
also dim as they age, but generally fail completely before reduced
brightness becomes a major issue.

Contrast measures the difference in luminance between the brightest
and dimmest portions of an image, and is expressed as a ratio. The
ability to display a high-contrast image is an important aspect of
image quality, particularly for text. An average CRT monitor may have
a contrast ratio of 200:1, and a superb CRT 250:1. An inexpensive FPD
may have a contrast ratio of 200:1, and a superb FPD 500:1. In other
words, even an inexpensive FPD may have a better contrast ratio than
an excellent CRT monitor.

Even good flat-screen CRTs are subject to objectionable reflections
when used in bright environments, such as having the screen facing a
window. Good FPDs are much superior in this respect. Short of direct
sunlight impinging on the screen, a good FPD provides excellent
images under any lighting conditions.

A typical CRT is at least as deep as its nominal screen size. For
example, a 17-inch CRT is often 17 inches or more from front to back.
Large CRTs may be difficult to fit physically in the available space.
Conversely, FPDs are quite shallow. The panel itself typically ranges
from 1.5 to 3 inches deep, and even with the base most FPDs are no
more than 7 to 8 inches deep. Also, where a large CRT may weigh 50 to
100 pounds or more, even large FPDs are quite light. A typical
15-inch FPD might weigh 12 pounds, a 17-inch unit 15 pounds, and even
a 20-inch unit may weigh less than 25 pounds. That small size and
weight means that it's possible to desk- or
wall-mount an FPD with relatively inexpensive mounting hardware,
compared to the large, heavy, expensive mounting hardware needed for
CRTs.

Stated FPD display sizes are accurate. For example, a 15-inch FPD has a display area that actually measures 15 inches diagonally. CRT sizes, on the other hand, are nominal because they specify the diagonal measurement of the entire CRT, part of which is covered by the bezel. For example, a nominal 17-inch CRT might have a display area that actually measures 16.0 inches diagonally. A couple of lawsuits several years ago convinced CRT makers to begin stating the usable size of their monitors. This is stated as VIS (viewable image size or visible image size), and is invariably an inch or so smaller than the nominal size. This VIS issue has given rise to the belief that a 15-inch FPD is equivalent to a 17-inch CRT, a 17-inch FPD to a 19-inch CRT, and so on. In fact, that's not true. The image size of a typical 17-inch CRT is an inch or so larger than that of a 15-inch FPD, as is the image size of a 19-inch CRT relative to a 17-inch FPD.

A typical 17-inch or 19-inch CRT consumes 100 to 125 watts while
operating. A typical 15-inch FPD consumes 35 watts, a typical 17-inch
FPD 50 watts, and a typical 19-inch FPD 70 watts. At 20% to 60% the
power consumption of a typical CRT, FPDs reduce electricity bills
directly by consuming less power, and indirectly by reducing heating
loads on air conditioning systems.

FPDs also have many drawbacks relative to CRT monitors. Note that not
all FPDs suffer from all of these flaws, that newer models are less
likely than older models to suffer from any particular flaw, and that
inexpensive models are much more likely than premium models to suffer
from these flaws, both in number and in degree.

The primary downside of FPDs is their hideously high cost. For
example, for the $300 cost of a good entry-level 15-inch FPD, you
could buy

two good 17-inch CRT monitors or one
excellent 19-inch CRT monitor, either of which provides both a larger
display area and better display quality than the entry-level FPD.
This is one area in which newer, better FPD models suffer much more
than older, less-capable models because a good new FPD
isn't cheap. Don't expect the price
of FPDs to drop anytime soon. Throughout 2002, display manufacturers
and panel manufacturers sold FPDs near or even below cost to gain
market share. In 2003, the need for better margins forced
manufacturers to begin increasing prices. Accordingly, an FPD that
sold for $400 in early 2003 was by July 2003 selling for $500 or
thereabouts. We expect these higher prices to stabilize, but do not
expect any significant price reductions in the next year or so.

FPDs are designed to operate at exactly one resolution, which is
nearly always 1024 x 768 for a 14-inch or 15-inch FPD and
1280 x 1024 for a 17-inch or 19-inch FPD. Although you

can run an FPD at a resolution lower than it was
designed to use, you don't want to. Your choices are
to have a sharp image that occupies only a portion of the FPD screen,
or to use pixel extrapolation, which results in a full-screen image,
but with significantly degraded image quality.

A typical FPD uses an array of four CCRTs, which are similar to
fluorescent tubes and provide the backlight without which the image
cannot be seen. In early FPDs, the CCRTs were often rated at as
little as 10,000 hours of life. That sounds like a long time until
you realize that if you leave such a display on 24 hours a day, the
rated lifetime of the tubes is only about 417 days. And, of course,
components do sometimes fail before their rated lifetime has expired,
and the presence of four tubes quadruples the likelihood of an early
failure. The upshot was that early FPDs were often warranted for
three years, but with only a one-year warranty on the CCRTs. Many
people found that these early models failed within that one-year
period or shortly thereafter. That was disastrous because early
17-inch FPDs cost $2,000 or more and could not be repaired. Instead,
for all practical purposes, they had to be remanufactured at a cost
that was typically one-half to two-thirds the cost of a new display.

The situation is somewhat better with recent-model FPDs. Most
manufacturers now use upgraded CCRTs that are rated for at least
25,000 hours, and better models use CCRTs rated for 50,000 hours.
Also, although some current FPD models have been redesigned to allow
the CCRTs to be replaced without remanufacturing the entire unit,
replacing a backlight properly is a finicky job, even for the
manufacturer. Accordingly, nearly all FDP manufacturers replace the
entire unit rather than attempting to replace the CCRTs. However the
job is done, replacing the CCRTs out of warranty is an expensive
repair, even assuming that replacement parts are still available when
your unit needs to be repaired. Be very conscious of the rated CCRT
lifetime and warranty terms for any FPD you buy. Look for at least a
three-year warranty that covers parts and labor on all components,
specifically including the CCRTs.

Unlike phosphor pixels, which can be turned on or off almost
instantly, transistorized FPD pixels have a rise time and fall time
which may be noticeable when the screen displays fast-action video.
On inexpensive FPDs, this may be noticeable as a
"smearing" effect during operations
as undemanding as dragging a window to another location. More
expensive FPD units deal with this problem better, but even the best
of the current FPD units are not fast enough to deal with demanding
fast-motion video such as 3D gaming.

CRTs present essentially the same image quality regardless of viewing
angle. Conversely, FPDs present their best image quality only within
a relatively small viewing angle, although better FPD units have
larger viewing angles. When comparing viewing angles, make sure
you're comparing apples to apples. Some
manufacturers specify total angles, whereas others specify only
half-angles from the perpendicular. For example, one manufacturer
might specify a viewing angle of 80 degrees above and below the
centerline, while another might specify a total angle of 120 degrees.
The first display, of course, has a total viewing angle of 160
degrees80 above and 80 below the centerlinewhich is 40
degrees greater than the second display, but that may not be clear.
Note that some FPDs specify different horizontal and vertical viewing
angles.

Most graphic artists we've spoken to refuse to use
FPDs because the appearance of colors and the relationship between
colors change depending on the viewing angle. This problem is
particularly acute with inexpensive FPDs, although even premium units
exhibit it at least to some extent. The newest, most-expensive FPD
models, such as the Hitachi S-IPS units, minimize this problem to the
extent that most people will not notice it, but those who insist on
accurate color reproduction will likely still prefer high-end CRT
monitors.

An FPD panel is manufactured as a monolithic item that contains on
the close order of 1 million pixels. Even though current
manufacturing processes are quite good, many FPD panels have one or a
few defective pixels. These defective pixels may be always-on
(white), always-off (black), or, rarely, some color. People vary in
their reaction to defective pixels. Many people
won't even notice a few defective pixels, while
others, once they notice a defective pixel, seem to be drawn to that
pixel to the exclusion of everything else. Most manufacturer
warranties specifically exclude some number of defective pixels,
typically between five and 10, although the number may vary with
display size and, sometimes, with the location of the defective
pixels. As long as the display has that number or fewer defective
pixels, the manufacturer considers the display to meet its standards.
You may or may not find it acceptable.

Image persistence causes an image that has been displayed for a long
time to remain as a ghost-like second image, similar to the burn-in
problem on old monochrome monitors. This effect, although it is not
permanent, can be quite disconcerting, particularly if you are
working with images rather than text. This problem is much more
common with older and inexpensive FPDs than with high-end current
models.

Although the contrast and brightness of recent high-end FPDs are
excellent, most FPDs provide subjectively less-vibrant color than a
good CRT monitor. This is particularly evident in the darkest and
lightest ranges, where the tones seem to be compressed, which limits
subtle gradations between light tones or dark tones that are readily
evident on a good CRT. Also, many FPDs seem to add a color cast to
what should be neutral light or dark tones. For example, dark neutral
tones may appear shifted toward the blue (cooler) or red (warmer)
ranges. Again, this problem is less prevalent in high-quality,
expensive FPDs than in entry-level units, and is also more likely to
occur if you are using an analog interface versus a digital
interface.

16.2.4 Choosing a Flat-Panel Display

If
you have weighed the trade-offs carefully and decided that an FPD is
right for you, use the following guidelines when choosing one:

Regard TFT as a minimum. STN panels are not acceptable for desktop
use.

Current FPDs are available in analog-only, digital-only, and hybrid
analog/digital models. Analog input is acceptable on 15-inch models
running 1024 x 768, but on 17-inch models running 1280
x 1024, analog video noise becomes an issue. At that level
of resolution, analog noise isn't immediately
obvious to most users, but if you use the display for long periods
the difference between using a display with a clean digital signal
and one with a noisy analog signal will affect you on almost a
subconscious level. At 1024 x 768, we regard an analog
signal as acceptable. At 1280 x 1024, we regard a digital
signal as very desirable but not essential for most users. Above 1280
x 1024, we regard digital signaling as essential.

Insist on full 24-bit color support. Most current FPDs support true
24-bit color, allocating one full byte to each of the three primary
colors, which allows 256 shades of each color and a total of 16.7
million colors to be displayed. Many early FPDs and some inexpensive
current models support only 6 bits per color, for a total of 18-bit
color. These models use extrapolation to simulate full 24-bit color
support, which results in poor color quality. If a monitor is
advertised as "24-bit compatible,"
that's probably good reason to look elsewhere.
Bizarrely, many FPDs that do support true 24-bit color
don't bother to mention it in their spec sheets,
while many that support only 18-bit color trumpet the fact that they
are "24-bit compatible."

Most FPD makers produce two or three series of FPDs. Entry-level
models are often analog-only and use standard TFT panels. Midrange
models usually accept analog or digital inputs, and may use enhanced
TFT panels. Professional models may be analog/digital hybrids or
digital-only, and use enhanced TFT panels with IPS or MDVA. Choose an
entry-level TFT model only if you are certain that you will never use
the display for anything more than word processing, web browsing, and
similarly undemanding tasks. If you need a true CRT-replacement
display, choose a midrange or higher enhanced TFT model. For the
highest possible image quality, choose a high-end model that supports
IPS and is made by a top-tier manufacturer.

Decide what panel size and resolution are right for you. Keep in mind
that when you choose a specific FPD model, you are also effectively
choosing the resolution that you will always use on that display.

Verify the rated CCRT life. For an entry-level FPD that will not be
used heavily, a 25,000-hour CCRT life is marginally acceptable. If
you will use the FPD heavily, insist on CCRTs rated at 50,000 hours.

Buy the FPD locally if possible. Regardless of whether you buy
locally, insist on a no-questions-asked return policy. FPDs are more
variable than CRT monitors, in terms of both unit-to-unit variation
and usability with a particular graphics adapter. This is
particularly important if you are using an analog interface. Some
analog FPDs simply don't play nice with some analog
graphics adapters. Also, FPDs vary from unit to unit in how many
defective pixels they have and where they are located. You might
prefer a unit with five defective pixels near the edges and corners
rather than a unit with only one or two defective pixels located near
the center of the screen.

In return for the higher price you pay at a local store, ask them to
endorse the manufacturer's warrantythat is,
to agree that if the FPD fails, you can bring it back to the store
for a replacement rather than dealing with the hassles of returning
the FPD to the manufacturer.

If possible, test the exact FPD you plan to buy (not a floor sample)
before you buy it. Ideally, in particular, if you will use the analog
interface, you should test the FPD with your own system, or at least
with a system that has a graphics adapter identical to the one you
plan to use. We'd go to some extremes to do this,
including carrying our desktop system down to the local store. But if
that isn't possible for some reason, still insist on
seeing the actual FPD you plan to buy running. That way, you can at
least determine if there are defective pixels in locations that
bother you.

Decide which models to consider (but not the specific unit you buy)
based on specifications. Any FPD you consider should provide at least
the following:

Controls





Auto Adjust, Brightness, Contrast, Horizontal Position, Vertical
Position, Phase, Clock, Color Temperature, RGB Color Adjustments,
Saturation, Hue, Recall Default Settings, and Save Custom Settings.




Warranty





Inexpensive FPDs may have a one-year parts and labor warranty, which
is inadequate. Inexpensive models may instead have a three-year
warranty on parts and labor, but warrant the CCRTs for only one year.
In effect, that's just a one-year warranty with
window dressing because the CCRTs are the one component that is by
far the most likely to fail. Insist on a three-year parts and labor
warranty that covers all parts, including CCRTs. If the manufacturer
offers an extended warranty that covers all parts, consider buying
that warranty.




Other specifications vary according to FPD size. For 15-inch models,
the minimum specifications for an analog FPD are listed with
preferable values for an analog/digital FPD in parentheses. For
17-inch and larger models, although analog-only models are available,
we do not recommend those and so list only minimum specifications for
a digital FPD:

15 inches





TFT flat panel; 15-pin VGA analog connector (15-pin analog, DVI-D,
S-video, and RGB composite connectors); pixel pitch, 0.297 mm;
contrast ratio, 300:1 (500:1); brightness, 200 nit typical (300 nit
typical); maximum resolution 1024 x 768 at 60 Hz or 75 Hz
for analog (1024 x 768 at 60 Hz or 75Hz for analog and
1024 x 768 at 60 Hz for digital); viewing angle 120
degrees horizontal by 85 degrees vertical (130 degrees by 110
degrees); autosync range 31.5 to 60 KHz horizontal and 56 to 75 Hz
vertical (same); video clock frequency 80 MHz (same); rise time 40 ms
(25 ms); fall time 40 ms (25ms). As of July 2003, a 15-inch FPD
meeting the minimum specifications can be purchased for about $350.
One meeting the higher specifications costs about $475.




17 inches and larger





TFT flat panel; DVI-D connector; pixel pitch, 0.264 mm; contrast
ratio, 400:1; brightness, 250 nit typical; maximum resolution 1280
x 1024 at 60 Hz digital; viewing angle 150 degrees
horizontal by 140 degrees vertical; autosync range 24 to 80 KHz
horizontal and 56 to 75 Hz vertical; video clock frequency 135 MHz;
rise time 25 ms; fall time 25ms. As of July 2003, a 17-inch FPD
meeting these minimum specifications can be purchased for about $475,
and a 19-inch unit for less than $800.




Choose the specific FPD you buy based on how it looks to you.
Comparing specifications helps narrow the list of candidates, but
nothing substitutes for actually looking at the image displayed by
the FPD. Some people like all FPDs, some dislike all FPDs, and some
have strong preferences for one or another brand of FPD.

In FPDs, the best choices are more limited than for CRT monitors. We
consider the first tier in FPDs to include only Hitachi and Fujitsu,
with Samsung straddling the low first-tier/high second-tier boundary.

There is a distinct difference in image quality between entry-level
and professional models, even those from top-tier makers. For
example, the $325 Hitachi CML152 is one of the best entry-level
15-inch FPDs available, and yet we (and Hitachi) regard its image
quality as suitable only for such undemanding tasks as word
processing, web browsing, and similar general duties. Where image
quality is critical, such as with desktop publishing, CAD/CAM, or
imaging, a professional model is the minimum to consider, and you may
well decide that a CRT monitor is preferable.