就光说一下液晶显示器吧
What is a LCD Monitor?
LCD displays were used on laptop computers before the technology improved enough to make the jump to desktop monitors. An LCD monitor consists of five layers: a backlight, a sheet of polarized glass, a "mask" of colored pixels, a layer of liquid crystal solution responsive to a wired grid of x, y coordinates, and a second polarized sheet of glass. By manipulating the orientations of crystals through precise electrical charges of varying degrees and voltages, the crystals act like tiny shutters, opening or closing in response to the stimulus, thereby allowing degrees of light that have passed through specific colored pixels to illuminate the screen, creating a picture.
As LCD technology evolves, different techniques for producing color emerge. Active-matrix or TFT (thin film transistor) technology produces color and images as sharp as any CRT and is generally considered superior to passive-matrix technologies.
Important specifications to consider when shopping for an LCD monitor include contrast ratio, brightness (or "nits"), viewing angle, and response time.
Contrast ratio relates to the display's comparative difference between its brightest white values and its darkest black values. A higher contrast ratio will have truer colors with less "wash out." The standard offering for lower end models is commonly 350:1. Many experts recommend a contrast ratio of 500:1 or better.
An LCD monitor is brighter than a CRT, giving the consumer little reason to hunt for an especially bright model. Brightness is measured in nits, or one candela per square meter. Anywhere from 250 - 300 nits is standard. If the nits are much higher you'll likely end up adjusting the brightness way down.
The viewing angle is an especially important consideration if you plan to have multiple people viewing the LCD monitor at any given time. There is a vertical and a horizontal viewing angle specification, which refers to the degree you can stray from dead center before the picture starts to wash out. High contrast levels usually go hand-in-hand with wider viewing angles. Many recommend a viewing angle of at least 140 degrees horizontal and 120 degrees vertical. The wider the viewing angles, the better.
Response time is measured in milliseconds (ms) and refers to how long it takes pixels to turn from completely white to black and back again. Smaller values represent a faster response time and are more desirable, especially for gaming or viewing video. If the response time is slow, "ghosting" or "trailing" can occur with fast-moving images, as repaints of the screen overlap. A maximum response time should be no more than 25ms for general use, and 17ms is better. Many gamers report no ghosting using an LCD monitor with a response time of 16ms or less.
LCDs use only one-third to one-half the electricity of their CRT counterparts. They are much easier on the eyes, take up 90% less space, and only weigh a few pounds. They also emit far less low-frequency radiation than CRTs. This makes LCDs a great choice for nearly everyone, and ideal for people who work all day in front of the screen. Colors may change hue as one moves to the outer limits of the viewing angle, particularly on displays with narrow viewing angles and low contrast ratios. For this reason graphics professionals that require exacting color consistency regardless of viewing angle generally use CRTs, though LCDs have improved in this regard.
An LCD monitor comes in standard sizes from 15-inches to 21-inches, and larger. The viewing screen is the same size as the rated display, unlike CRT monitors. Therefore a 15-inch LCD will have a 15-inch viewing screen.
A potential weak link of an LCD monitor is the backlight. Many monitors come with a 3-year warranty, but stipulate 1 year for the backlight. Models with 3-year warranties that cover the backlight usually cost a little more but may be worth the extra investment.
How LCD Monitors Work
LCD monitors, as their name suggests, use liquid crystal display (LCD) technology, making it far different from the ordinary CRT monitor. An LCD is a thin and flat display device composed of pixels arrayed in front of a light source or reflector.
LCDs, in turn, use liquid crystals, which were first discovered in 1888. These crystals are actually liquid chemicals that align perfectly when subjected to electrical fields; when they're properly aligned, they allow light to pass through them. LCDs use this property by using electrical currents to align the crystals and allow varying levels of light to pass through and create the desired images and colors.
To be more technical, the liquid crystals are sandwiched between two pieces of polarized glass ("substrate"). The fluorescent light source, also known as the backlight, emanates light that passes through the first substrate. The electrical currents then cause the crystals to align, allow varying levels of light to pass through to the second substrate. The end result is what you see onscreen.
LCDs can use either active-matrix or passive-matrix structure. Most LCD monitors, along with LCD TVs, use active-matrix.
Any discussion regarding LCD monitors won't be complete without the word "pixel". A pixel is a single point in a graphic image, and stands for "picture element". Each pixel on an LCD monitor comprises of three cells -- one for the color red, one for green, and the last one for blue. Electric currents are used to straighten the liquid crystals within each cell so that light is not bent at this level. An active matrix thin-film transistor is used to activate each cell.
LCD Monitor Advantages：
LCD monitors have lots of things going for them. These traits entice millions of consumers to buy an LCD monitor every year:
Uses Less Power. LCDs also produce less heat, which means less load on air conditioning. Takes up less space. LCD monitors are small, thin, and weigh less. Highly adjustable. Many LCD models can be rotated 90 degrees, allowing you to view websites in portrait mode. LCDs can also be mounted on the wall or on an arm. No flicker. LCDs don't have lines that need to be scanned like in CRTs. No flicker = a lot less eye strain. Less glare. Due to the material of the LCD screen, less light is reflected at the user. Same with "no flicker", this results in less eye strain. Brightness. LCD monitors are brighter than the traditional CRTs. Less distortion. Using a direct digital input from the graphics card produces cleaner 'output'. The monitor's perfect geometry means images aren't distorted, which is a boon for graphic designers and the like.
LCD Monitor Disadvantages:
While LCD monitors have a lot of strengths, they still have weaknesses that might turn off potential buyers. However, it's our opinion that these disadvantages don't really detract from the benefits of using an LCD monitor.
More expensive than CRTs. You pay for what you get; LCDs look good and are good for your eyes (see Advantages article). Dead pixels. When the electrical current to one or more pixels does not operate properly, one or more cells are permanently aligned, resulting in a dead pixel. Screen care and fragility. LCD monitors may be slim and sexy, but they're also more prone to damage and screen breakage. Native resolution. LCD monitors can only display information well at the resolution they were designed for. At any other resolution, image quality will suffer. Pixel response time. In videos and fast-paced video games, LCDs suffer from the ghosting effect. Viewing angles. Looking at an LCD monitor from an angle causes the image to look dimmer or even disappear completely. Colors. The color accuracy of an LCD monitor does not match that of a CRT monitor's.
LCD Monitor Sizes:
When shopping for an LCD monitor, the issue of how large a monitor you'll buy always pops up. Usually it's just a question of budget -- thrifty consumers go for the smaller monitors, while those who can afford go for the giants. However, you should also consider your work space; if it's cramped, then there's no use in buying a 22-inch LCD monitor!
One thing you need to remember about the different LCD monitor sizes: they display information well at only the resolution they were designed for, which is known as the "native resolution". CRT monitors don't have this problem. If you change your LCD monitor's resolution settings, the display scales the image and the quality suffers (but not by much, though). Listed below with each monitor size is its respective native resolution.
15 InchThe smallest LCD monitors you'd usually find nowadays would be the 15 inch LCDs. These monitors are available for only a few hundred dollars, and they have done well in flooding the market with LCDs and bringing down prices.
15 inch LCD monitors have a 1024x768 native resolution. These monitors are great for CRT switchers, but not for gamers, graphic designers, and serious computer users.
17 Inch17 inch LCD monitors are a step up the ladder. These monitors have a native resolution of 1024x768 to 1280x960, and are more comfortable for older people. However, they're also a tad more expensive than smaller monitors.
There are also high quality 17" LCDs that are good for gamers; some models feature pixel response times as low as 12ms. This allows gamers to enjoy their games without the ghosting/blurring problem that plague lower end LCDs.
19 InchThe larger it becomes, the more expensive it gets. But if you've got the money, 19 inch LCD monitors are worth it -- they can take the burden off the eyes greatly. These models are excellent for those who need to read and write a lot as well as concerned about eye strain.
19 inch LCDs usually sport a native resolution of 1280x1024 or 1600x1200.
20+ Inch20 inch and larger LCD monitors are for those demanding the best and can afford to shell out the money. These massive screen real estate monitors are the top choice for avid gamers, graphic designers, CAD designers, and movie makers/fanatics.
20 inch LCD monitors usually boast of 1600x1200 native resolution, and screens above 22 inches can easily reach 1900x1220 resolution.
These extremely large LCD screens pose some problems, though. For example, the 30-inch Apple Cinema HD Display requires two DVI inputs to properly function. If you're prepared to spend cash on large LCDs, be prepared to shell out more for powerful。
温馨提示：答案为网友推荐，仅供参考