Home Theater: TV Technologies

Video: How HDTV is different from Standard

Video: Plasma vs. LCD

Plasma HDTV -

Plasma is a thin flat panel technology that works with using a network of red, green and blue phosphors between two layers of thin glass. Each one of these red, green, and blue elements makes up one single pixel that produces lighting when charged by an electric pulse such as plugging it into an electric outlet. The red, green, and blue phosphors are sensitive to the electric charge, and therefore millions of color combinations can be made by manipulating the pulse. There is no need for rear light projection due to the light-producing phosphors elements. What the lack of a rear light projection does is make it possible for the TV to be thing.

Pros:

• Amazing picture quality.
• Beautiful colors
• Nicely thin and wall mount capable.
• The best in viewing angles
• Excellent brightness for good viewing in a bright sunny room.
• Minimal screen door effect when it comes to close distances.

Cons:

• Burn in problems can occur, but getting better as the new technologies roll out.
• Brightness definitely reduces over time when watching.
• Loves to eat a lot of power.
• Available past a certain, screen size, 42′ and up, you may find some models that go one down.

LCD HDTV

There are two types of LCD, rear projection and flat panel. The differences between the two technologies is how they project the back lightning that’s required for LCDs. As its name shows, rear projection uses little rear projection lamps to provide the lighting that goes through the liquid crystals This allows rear projection LCDs to get 50′ and larger screens, flat panel LCDs are very thin because they use slimmer back lighting techniques to reflect light through the liquid crystals. One huge negative is the size of them, yes they’ll go up to 42′ or more, but if you’re into big televisions you may want to look for a rear projection or a DLP, which I will talk about next.

Pros:

• Available in smaller sizes, unlike plasma.
  
• Thin for easy wall mounting.
• Excellent picture quality.
• Excellent color quality.
• Excellent brightness levels, still easy to see in bright rooms.
  
• No burn-in.

Cons:

• Does not have the best blacks which leads to lack of shadow depth.
• Motion Blur. Newer LCD models have reduced motion bur.
• Not too good with viewing from angles, but definitely getting improved with the newer models.
  
• Limited in size, if you want past 42′ inches, you may have to go with rear projection LCD.

Video: DLP Technology

DLP (Digital Light Processing) is a rear projection that uses a chip technology with hundreds of thousands of little mirrors to reflect light and produce a picture. The technology is produced by Texas Instruments and it’s called Digital Micromirror Device (DMD) chip.

Each mirror in the DMD chip represents one or two pixels. Each mirror can tilt very quickly to reflect light onto the screen and off the screen. When the mirrors are tilted away from the screen, the pixel corresponding to the mirror will be black, when the mirror is tilted towards the screen, the pixel will light up with reflected color. Each mirror can tilt over a thousand times per second, which is too fast for the human eye to see. A matrix of these fast moving mirrors is what produces an image.

A color wheel is required to produce color onto the image.The color wheel is made up of multiple colors making up red, green, and blue that change the reflected light off of the mirror to a specific color. The mirrors tilting with reflected light is timed accurately with a specific color in the fast rotating color wheel, therefore, producing a colored pixel.

There are different DLP chipsets, that will have difference in quality. There is also a difference in price when looking at the different sets. Here are some of the different ones: (brought to you by Wikipedia)

• HD2 – 1280 x 720 mirrors, no wobulation is used to produce a resolution of 720p with a 1500:1 contrast ratio.
• HD3 – 640 x 720 mirrors, wobulation is used to produce a resolution of 720p with a 2000:1 contrast ratio.
• HD2+ – 1280 x 720 mirrors, no wobulation is used to produce a resolution of 720p with a 2500:1 contrast ratio.
• HD4 – 640 x 720 mirrors, wobulation is used to produce a resolution of 720p with a 2500:1 contrast ratio.
• xHD4 – 960 x 1080 mirrors, wobulation is used to produce a resolution of 1080p with a 10,000:1 contrast ratio.

Pros:

• Excellent contrast ratio
• Excellent blacks, important for shadow dept. Also if you’re using for gaming it’s a good TV.
• Excellent colors
• Stunning picture quality.
• No burn-in.
• High horizontal viewing angles
• Great brightness, for viewing or playing in bright room.
  
• No motion blur, which is good if you’re a sports fan.

Cons:

• Rainbows: Quick flashes of colored light on the edge of sharp transitions from black to white. Get’s a little annoying, but does’t happen to often.
  
• Low vertical viewing angles.
• You will have to change the bulb approximately every 4000 hours, could get a little expensive.
• It is thick, so not wall mountable.

CRT HDTV

This technology has been around for a very long time before the slim and dlp televisions came out. They are those early versions of HDTV, the one you and your friend had to help your parents carry into a new home. Great technology for the time being, with excellent blacks and colors, but in quality they are nothing comparing to DLP’s, LCD’s or Plasmas.

Pros:

• One of the best when it comes to blacks.
• Excellent in contrast ratio.
• One of the cheapest technologies.
• Great picture quality.

Cons:

• They are large and heavy.
  
• Brightness levels are low.
  
• Reflections, can be bad.
• There is no native resolution.
• Over time, tubes become misaligned reducing sharpness and picture quality overall.
• Burn in problems.
• Analog conversion of digital video signals introduces sampling noise into the picture.

Front Projection HDTV

If none of the technology above satisfies your needs, than you may want to turn to Projectors. Why would anyone want projectors as their home theater setup up? If you’re into big screens and want to get the most out of that video game you’re playing, or if you want to feel like you’re part of it, Projectors are your friend. You can get big screens to project the video onto. Great if you have a big family and you all want to watch a movie.

Pros:

• You can purchase large screens that go way beyond any other technology.
  
• No reflections or glare, since it doesn’t use glass or plastic.
• The ultimate flat panel. Since it’s only a screen.
• No fixed aspect ratio.

Cons:

• Must keep away from light, or the quality will suffer.
  
• Installation and finding where to place it.
  
• Lamp life is short, and may need constant replacing.
• There is no build-in tuner.

Projector: What to look for when buying one: