Frequently Asked Questions About Electronics
What Is Plasma?
What Is LCD?
What Is DLP?
What Is HDTV?
What Is EDTV?
What Is Burn-in?
What Is Response Time?
What Is Plasma?
Plasma Television/Monitors apply voltage to any of more than a million tiny chambers filled with neon, xenon, krypton, or argon, or a combination of these gasses. Using a matrix of wires to "address" each of the chambers, the gasses ionize into plasma that emits ultraviolet light. Light strikes red, green, or blue phosphors coated on the inside of the chambers, and a pixel emits that respective colored light.
- Max Resolution: 1366 x 768
- Burn-in Can occur
- Side-view image remains the same
- Lifespan: 50,000 hours
What Is LCD?
LCD (Liquid Crystal Display) televisions work passively, shining a light behind the LCD panel. They include the same number of pixels as a plasma display, but the pixels are colored red, green, and blue. When voltage is applied to a pixel, via a matrix of wires, the pixel become dark and light cannot show through it.
- Max Resolution: 1600 x 1200
- Burn-in Can Not occur
- Side-view looses contrast and brightness
- Lifespan: 60,000 hours
What Is DLP?
The technology inside DLP is often referred to as either "micro-mirrors" or DMD. It works this way: Build a few hundred thousand tiny mirrors, then line them up in 800 rows of 600 mirrors each. Now attach a hinge to the 480,000 mirrors. Attach each of those mirrors to it's own very tiny motor! Power each motor with electrostatic energy! The motors tilt their mirrors up to 20 degrees at incredible speeds. This allows the mirrors to modulate light from a lamp, and send the "modulated signal" out through a lens onto a screen. The most amazing part about DLP micro-mirrors, is the scale of size. The 480,000 mirrors (actually 580,000 are used), hinges and motors are packed into a "wafer" a bit larger than your thumbnail.
- Max Resolution: 1280 x 720
- 5ms Refresh Rate
- Sharper Image
What Is HDTV?
HDTV provides pictures with several times the clarity of DVD's and over 5 times the resolution of regular television picture.
HDTV provides vivid color, including a wide range of hues (such as subtle purples and reds) without any bleeding at the edge of the image.
HDTV images are as detaild as a high-resolution photograph. It's like looking through a window. When watching TV programs in HD, you will be amazed at the sharpness of the picture. You can even pick out the specks of color in the actor's eyes, or see individual sweat drops on a football player -- details you could never see through regular television.
All HDTV can deliver 5.1 channel Dolby Digital Suround Sound -- just like true theater sound.
HDTV refers to a complete product/system with the following minimum performance attributes:
- Display Scanning Format: Has active vertical scanning lines of 720 progressive (720p), 1080 interlaced (1080i), or higher
- Receiver: receives ATSC terrestrial digital transmission and decodes all ATSC Table 3 video formats
- Audio: Receives and reproduces, and/or outputs Dolby Digital audio
What Is EDTV?
EDTV refers to a complete product/system with the following minimum performance attributes:
- Display Scanning Format: Has active vertical scanning lines of 480 progressive (480p), or higher
- Receiver: receives ATSC terrestrial digital transmission and decodes all ATSC Table 3 video formats
- Audio: Receives and reproduces, and/or outputs Dolby Digital audio
What Is Burn-in?
Burn-in occurs when an image is left on the screen too long. For instance, when you pause a DVD for a long time. Once burn-in occur, you will always see a ghost of the burnt-in image no matter what you are watching. This is because some of the pixels on the TV can no longer produce as much light as others, so they will always appear darker. Most commonly this occurs from playing video games too long or from watching letterbox material too often. The easiest way to avoid this problem is to limit video game time and watch material in a full screen format as much as possible.
Burn-in is a consideration with plasma TVs, but not LCDs. Plasma TVs, like traditional CRT TVs create their own light. They make light by exciting a chemical coating inside the screen called "phosphors". The burn-in issue happens when you continually ask some of these phosphors to make light while others nearby are basically sleeping. LCDs on the other hand make a picture by blocking light from and outside source (basically a powerful lightbulb). This makes it impossible for burn-in to happen on a LCD screen.
What Is Response Time?
Response time is the time it takes for a liquid crystal cell to go from active (black) to inactive (white) to active (black) again. It is measured in milliseconds or (ms). Lower numbers mean faster transitions (i.e. 16ms is faster than 25ms.) and therefore less visible image artifacts.
