This is the measurement, in inches, of the displayable area of the screen from the bottom left corner to the top right corner of the display.
While another confusing aspects with LCD's is their aspect ratio of the screen. Most CRT displays have a 4:3 ratio of horizontal to vertical measurement. Some LCD screens are marketed as a wide screen display that still have the marketed diagonal measurement, but its aspect ratio can be similar to the 16:9 displays used by wide screen TVs.
All LCD screens can actually display only a single given resolution referred to as the native resolution. This is the physically number of horizontal and vertical pixels that make up the LCD matrix of the display. Setting a computer display to a resolution lower than this resolution will either cause the monitor to use a reduced visible area of the screen or it will have to do extrapolation. This extrapolation attempts to blend multiple pixels together to produce a similar image to what you would see if the monitor were to display it at the given resolution but it can result in fuzzy images.
Here are some of the common native resolutions found in LCD monitors:
14-15" : 1024 × 768 (XGA)
17-19" : 1280 × 1024 (SXGA)
20"+ : 1600 × 1200 (UXGA)
19" (Widescreen) : 1440 × 900 (WXGA+)
20" (Widescreen) : 1680 × 1050 (WSXGA+)
24" (Widescreen) : 1920 × 1200 (WUXGA)
30" (Widescreen) : 2560 × 1600
This is a measurement of the difference in light intensity between the brightness white and darkest black. The contrast ratio of a LCD flat panel is the rating of how distinguishable various shades of color are. The higher the contrast ratio of the screen, the better the color representation is by the monitor. An LCD monitor with 450:1 rate, for instance, is better than a monitor with a 400:1 one.
LCD's produce their image by having a film that when a current runs through the pixel, it turns on that shade of color. The problem with the LCD film is that this color can only be accurately represented when viewed straight on. The further away from a perpendicular viewing angle, the color will tend to wash out. The LCD monitors are generally rated for their visible viewing angle for both horizontal and vertical. This is rated in degrees and is the arc of a semicircle whose center is at the perpendicular to the screen. A theoretical viewing angle of 180 degrees would mean that it is fully visible from any angle in front of the screen. A higher viewing angle is preferred over a lower angle unless you happen to want some security with your screen.
In order to achieve the color on a pixel in an LCD panel, a current is applied to the crystals at that pixel to change the state of the crystals. Response times refer to the amount of time it takes for the crystals in the panel to move from an on to off state. A rising response time refers to the amount of time it takes to turn on the crystals and the falling time is the amount of time it takes for the crystals to move from an on to off state. Rising times tend to be very fast on LCDs, but the falling time tends to be much slower. This tends to cause a slight blurring effect on bright moving images on black backgrounds. The lower the response time, the less of a blurring effect there will be on the screen.
With LCD monitor with a response time of approximately 25ms you won't have many problems, but we would suggest to look for 16 ms or less for gamers.
Monitor brightness is measured in nits (candelas per meter squared - cd/m²). A typical CRT monitor brightness is 100 nits, whereas most LCD monitors vary between 200 to 300 nits. LCD monitors can have their brightness increased by simply making the backlight stronger.
Most LCD panels still use the traditional analog VGA connector known as the DSUB-15 or HD15 connector. This is the same connector that is used on all CRT monitors and on most PC video cards. Newer LCD displays and video cards are starting to use the DVI connector. This is a digital interface that is supposed to allow for a cleaner and brighter picture compared to standard VGA connectors. Check to see what type of connector your video card can use before buying a monitor to ensure you get a compatible monitor. Some monitors may also come with composite video connectors to allow them to function as a TV screen.
The LCD screen is manufactured using high precision technology. Due to the nature of the complex manufacturing process, the screen may have defects that appear as (bright and dark) dots on the screen cosmetically. This does not impair the performance of the LCD monitor and is not considered defective in the LCD industry. FIDA International (S) Pte Ltd reserves the right to refuse a warranty claim for repair or replacement of the LCD monitor if the number of defective pixels falls within the specification stated below.
LCD Monitor Pixel Specs
The specifications for the number of the defects that are deemed to be acceptable for all size of LCD are:
Bright Pixels: 3
Dark Pixels: 3
Total Pixels: 5
A pixel or picture element is a composition of three sub-pixels in the primary colors of red, green, and blue. Three cells of liquid crystal material formed the red, green and blue sub-pixels that together allow the full range of colors to be displayed at each pixel position in an active matrix LCD monitor.
To control each sub-pixel, the individual transistors are arranged in an array on the rear glass. An anomaly on any of these individual transistors will cause a bright or dark pixel to appear. Generally, these anomalies will only appear during the process of manufacturing. In such, additional bright or dark pixels should not appear over time.
The number allow for the non-performing pixels has a direct impact on the yield of the process. The cost of an LCD display would be many times higher if the industry attempts to set a zero standard for the non-performing pixel today.
Fortunately, majority of the customers and applications allow a low level of non-performing pixels and enjoy the luxury of owning the active matrix LCD monitor at a lower cost.