CompTIA®A+ Exam Notes : Compare And Contrast Types Of Display Devices And Their Features

1. PC Hardware

1.10 Compare and contrast types of display devices and their features.

1. When you are installing a different SVGA monitor, it is unlikely that the new monitor has the same capabilities as the old one. As a result, the image on the screen may not be readable. In such instances, change the video resolution to Standard VGA before installing the new monitor. You can change the resolution appropriately after the image on the screen is readable with the new monitor. It may also be necessary to load appropriate device driver, if you are installing a different display adapter.

2. If the LCD screen changes colors, like turning green and then blue or red, it is likely that you have a cable problem. First check the monitor cable whether it is loose. Then try to twist the monitor and see if there is any problem. If the problem occurs, it may be necessary to replace the LCD monitor cable.

3. You need more brightness when a projector is used in environment where there is plenty of light in the room. Higher lumens provide more brightness, but more expensive.

4. TFT LCDs, also known as "active matrix", were developed as a variant of LCD. TFT LCDs improved the color, contrast and response times of passive matrix LCDs. FT LCD stands for "Thin Film Transistor" and "Liquid Crystal Display".

5. The two most common types of TFT LCDs are IPS TFT LCD and TN TFT LCD. TN generally has a faster response time, which provides better entertainment experiences for watching sports or gaming, but IPS was designed to solve TN display flaws, such as a poor viewing angle and low-quality color reproduction.

6. LCD display can't be viewed by itself. It requires back lighting, just like your digital watch requires a back light to view the time. At present, there are two main methods of backlighting in LCD flat-panels: Cold-Cathode Fluorescent Lamp (CCFL) and LED (light-emitting diode). LCD with CCFL back lighting were widely used in TVs and computer monitors. However, they are becoming obsolete these days. LCD with LED back lighting is widely used in TVs and computer monitors. Now a days. LED back lighting is most popular as it requires less power, and lasts longer. Note that the back lighting technologies should not be confused with LCD display technologies. The popular term LED TV is a bit misleading as it is actually an LCD TV, but with LED back lighting instead of CCFL.

7. Plasma display is entirely a different technology when compared with LCD. In plasma display each pixel on the screen is illuminated by a tiny bit of plasma or charged gas, somewhat like a tiny neon light. Plasma displays offer high refresh times, better viewing angles and color schemes when compared with LCD displays. However, they consume more power, and bulkier.

Some of the most widely known LCD panel types are:

1. TN (Twisted Nematic): The advantages of these panels are low manufacturing cost and a relatively high level of responsiveness; the pixels change their state quickly which helps make moving images appear smoother. Some Twisted Nematic displays have double the usual refresh rate (120Hz instead of 60Hz) allowing them to take advantage of 'active 3D shutter' technologies and allowing them to display twice as much information every second for a smoother gaming experience. Even 144Hz refresh rates have become possible using this technology.

2. VA panels (Vertical Alignment panels: These panels are more like TN panels, the main advantage is its efficiency at blocking light from the backlight when it's not wanted. This gives deeper blacks and higher contrast ratios of around 2000:1 - 5000:1 Another key advantage of VA is the improved viewing angles and colour reproduction compared to TN. The main disadvantage is its slow responsiveness.

3. IPS and PLS: IPS is short for In-Plane Switching is a technology developed chiefly by LG Display, PLS (Plane to Line Switching) technology by Samsung and AHVA by AUO. These are sometimes simply referred to collectively as 'IPS-type' panels. The main advantage is their superior colour accuracy, consistency and viewing angles when compared to the other LCD technologies. Usually, you can get contrast ratios of 1:1000 on these panels.


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