Televisions Product Guide

Televisions
DTV - A New Beginning, A New Era in Television

In June 2009, the United States made a move that simplified television broadcasting and advanced it to a new age. With a flick of a switch, broadcast TV switched from analog to digital. All televisions that have ATSC TV tuners (integrated into most televisions made after 2006) can receive the new signals. Older televisions with analog NTSC tuners require a converter box to receive digital signals and convert them to analog. The Federal Communications Commission ran a special promotion on these converter boxes since 2008. Every TV sold today must have a digital ATSC TV tuner and will receive digital TV.

Now Digital TV (DTV) doesn't automatically mean that all television stations broadcast in High Definition TV (HDTV). Most still don't. Most still don't fill the wide screens of the newer television models. The shows still appear with squarish images, as in the older 4:3 perspectives that most people born before 2000 remember. That's because older shows (especially those in rerun syndication) were set in 4:3. In addition, not all local broadcasters can afford to upgrade equipment to broadcast in widescreen HDTV.

Now the USA just didn't arbitrarily decide to switch to DTV to be kind to major TV networks. There was a broader reason. The government wanted to free up some of these old analog frequencies. An important benefit of the switch to all-digital broadcasting is that it will free up parts of the valuable broadcast spectrum for public safety communications (such as police, fire departments, and rescue squads). Also, some of the spectrum will be auctioned to companies that will be able to provide access to more advanced wireless services, such as wireless broadband and improved WiFi network standards.

While smaller broadcasters may be struggling to upgrade their standard definition screens to high-definition, using DTV is extremely beneficial in the long term. A broadcaster is able to offer a super sharp "high definition" (HD) digital program or multiple "standard definition" (SD) digital programs simultaneously through a process called "multicasting." Multicasting allows broadcast stations to offer several channels of digital programming at the same time, using the same amount of spectrum required for one analog program. So, for example, while a station broadcasting in analog on channel 7 is only able to offer viewers one program, a station broadcasting in digital on channel 7 can offer viewers one digital program on channel 7-1, a second digital program on channel 7-2, a third digital program on channel 7-3, and so on. This means more programming choices for viewers. Further, DTV can provide interactive video and data services that are not possible with analog technology.



DTV to HDTV


The conversion to DTV makes HDTV possible. Analog signals consist of loops of waves of different sizes and lengths. These waves couldn't be controlled to meet the demands of new television displays. For one thing, waves needed certain cycles to be on and to be off. Digital signals are in the form of numbers, streams of 1 and 0 in infinite combinations. Those streams could be constant and consistent. Thus, they could be on at any cycle. The result was a better, deeper, fluid color image. This is known as Progressive display.

Older television displays had about 720x480 pixels, standard definition. A pixel is a dot of light. HDTV requires 1366x768 (720p) up to 1920x1080 (1080p). These resolutions are designed to simulate the appearance of a movie theater screen and follow the image-standard ratio that most movies comply with. That is a 16:9 aspect ratio.

USA DTV high definition standards broadcast at 720p. So televisions with 1366x768 resolutions can view HDTV easily. At this time, only Blu-ray discs will provide 1080p resolution and requires a 1920x1080 screen for best viewing.

What this means is that on a TV screen, there are 1920 pixels (dots of light) on a line from left to right. There are 1080 pixels from top to bottom, each row intersecting with 1920. This means there are over 2 million pixels on a screen. Larger size screens require larger sized pixels, delivering more light (brightness) to the image. Compared to 720x480 (analog standard definition), screen resolution is over 7 times higher in HDTV. In the comfort of your living room, you can view movies and television shows in widescreen format that (given the home viewing distance from the screen) rival movie theater imaging.

HDTV also adds a new level of sound. Sometimes referred as Dolby Digital, when a TV is connected to a home theater sound system, it can deliver 5.1 channels of surround sound. That's 1 center channel front speaker, 1 left front speaker, 1 right front speaker, 1 left rear speaker, 1 right rear speaker, and 1 subwoofer. Any show designed for HDTV is 5.1 compatible. Pre-HDTV shows will not follow unless they are upgraded.

See HDTV PDF Guide


Types of TV Screens


Over the past ten years, as manufacturers hurries to create a wide range of affordable widescreen televisions, many technologies came and went. Although it appeared, at one time, that projector systems might dominate, over 90 percent of the consumer market selects flat-panel television models. There are three technologies: Plasma, LCD, and LED. Of the three, LCD is the most popular. Let's go over the flat screen technologies.

Plasma

Plasma is the oldest of the flat screen technologies, emerging in the mid 1990's in the USA. Philips Electronics was one of the key developers. This thin panel used phosphor based gas that, when electronically charged, delivered very sharp images. The concept of phosphor wasn't new. Those older picture-tube CRT displays also used phosphor. Plasma screens can be found at sizes from 32-inch up to (over) 120-inch.

Plasma is an organic method of using gas and electricity to control electrons for the purest images. Fundamentally, a plasma display must illuminate tiny colored fluorescent lights to form an image. Each pixel is made up of three fluorescent lights -- a red light, a green light and a blue light. The central element in a fluorescent light is plasma, a gas made up of free-flowing ions (electrically charged atoms) and electrons (negatively charged particles). Under normal conditions, a gas is mainly made up of uncharged particles. When the display is off, the gas is in a stable state. Introducing free electrons into the gas by establishing an electrical voltage across it, the situation changes very quickly. The free electrons collide with the atoms, knocking loose other electrons. With a missing electron, an atom loses its balance. It has a net positive charge, making it an ion. The phosphors in a plasma display give off colored light when they are excited. Every pixel is made up of three separate subpixel cells, each with different colored phosphors. The phosphors deliver the Red, Green, and Blue colored lights, the prime palette of light on a color screen. From these, a plasma TV can deliver tens of millions of colors throughout the visual spectrum.

A plasma TV will perform exceedingly well under most ambient light conditions. A very bright light does not "wash out" its picture, nor does backlighting cause a glare on your TV screen. Most plasma screens are capable of displaying 16.77 million colors and has an average lifespan of up to 30,000 hours. That's equivalent to approximately 3.5 years of around-the-clock operation.

Because the wide spectrum of colors is derived organically through controlled excitation of electrons in gases, colors are extremely vivid and precise. Blacks and whites are more pronounced offering a contrast ratio that extends from true black to true white.

When compared side-by-side with an LCD screen, the range of colors and the contrast ratio of blacks to whites, Plasma images are purer and deeper. They provide wide viewing angles up to 160 to 170 degrees.

LCD

LCD represents liquid crystal display and is similar to the type of displays you'd find on a digital watch or MP3 player screen. It is mostly used in computer monitors. Unlike the gaseous plasma screens, LCD is perceived to be more stable because it is a solid-state. LCD panels are made of two layers of transparent material, which are polarized, and are "glued" together. One of the layers is coated with a special polymer that holds the individual liquid crystals. Current is then passed through individual crystals, which allow the crystals to pass or block light to create images. LCD crystals do not produce their own light, so an external light source, such as florescent bulb is needed for the image created by the LCD to become visible to the viewer.

Since LCD uses a backlight, the nature of that backlight can contribute to a diluted appearance in color saturation and to a reduced contrast. At home, however, LCD screens (like those seen on computer displays) offer excellent color integrity and extremely wide viewing angles at up to 178 degrees.

LCD screens are also structurally lighter and more energy efficient than plasma screens. Whereas it's possible for an average person to hand-carry a 32" LCD TV from a store, a similar plasma screen might weigh up to 50 percent more. LCD screen sizes can go from less than 3 inches to about 70 inches in size. The abundance of available liquid crystal material help make these screens very affordable.

Manufacturers of LCD screens are somewhat sensitive to a specification called contrast ratio. A contrast ratio deals with the shades and purity from black to white. A higher ratio represents a greater range and is favored over a lower ratio. A typical plasma screen may have a true (static) contrast ratio of greater than 20,000 to 1. A typical LCD screen might have a static contrast ratio of about 2,000 to 1. Over a few years another rating system, Dynamic Contrast Ratio, sprang up among specifications on LCD HDTV screens.

Dynamic contrast ratio is a measurement of the brightest white the HDTV can produce as compared to the blackest black, not at the same time or in the same scene. It's more what the screen can produce in the best conditions. For example, some LCD screens use technology that brightens the overall picture in well-lit scenes to achieve very bright whites, and dims the overall picture in low-lit scenes to achieve truer, darker blacks. A measurement of the whitest white in the brightly lit scene compared to the darkest dark in the low-lit scene results in the dynamic contrast ratio specification.

Static contrast ratio measures dark and light in a static shot, or the highest contrast ratio achievable within the same scene at the same time. This is a smaller number but a truer measurement in terms of the overall image quality. It's the measurement a shopper should take into account more so, perhaps, than the dynamic contrast ratio. But because the dynamic contrast ratio is a higher number, it's often the number used on the specification card of the HDTV. The difficulty arises when manufacturers hide the static contrast ration in lieu of the dynamic contrast ratio.

The general anecdotal wisdom indicates that getting an LCD screen with a dynamic ratio of 10,000 to 1 or more will deliver an excellent picture.

Most people enjoy their LCD HDTV screens. They are relatively inexpensive to buy, inexpensive to run, easy to use, and offer excellent image quality, especially in a dimly lit room. For the average viewer, LCD is the favored technology.

LED

LED represents Light Emitting Diode and is the newest of the flat panel HDTV technologies. As the name implies, an LED is a diode that emits light. The diode is the most basic semiconductor whose purpose is to conduct electrical current with some form of controlled variability. It is a purer light source delivering exceptional brightness for its small size.

An LED HDTV is structurally very similar to an LCD TV. The significant difference is that an array of LEDs is used as a backlight. The results include more vivid color and a contrast ratio that is superior to plasma. It's very evident when you view some of the new LED cell phone displays or Apple monitors.

When comparing screens, the LED screen delivers the most vivid image available. It is also slightly thinner than LCD flat panels. Pricewise, they run about 2 to 3 times the price of LCD.

The major manufacturers of LED HDTV are Samsung and LG. This helps keep LED HDTV prices at a premium level. Within the 50-inch screen size category, the LED is about twice the price of the LCD. Some say it really is worth it.



Refresh Rates/Response Times


Refresh Rates

You may hear terms like ClearScan 240Hz when referring to LCD or LED screens. This is associated with something called a Refresh Rate. You may have heard about Response Time. People often confuse these terms. They offer similar results but use two completely different measuring sticks.

Refresh rates refer to the number of times per second a TV screen is updated with a new image. The typical refresh rate for US TVs is 60 times per second (60 Hz). Using 110-volts AC at 60 Hz, your TV went off and on at around 60 times each second. LCD TVs suffer from motion blur. One technique used to help reduce motion blur is to increase the refresh rate to 120 times per second (120 Hz) or 240 times per second (240 Hz). Using these faster refresh rates allow action films, sports, and fast video games appear better on LCD and LED screens. Most televisions available in the market today, especially LCDs, have a 120Hz refresh rate. This 120Hz refresh rate is preferred to 60Hz because it doubles the image speed and produces smooth video with better clarity. Newer major brand televisions now are adding 240 Hz refresh rates for even better motion clarity.

Response Time

Refers to the time that it takes to change the state of on an individual LCD pixel. A pixel is a dot on your screen that contributes to the overall image. A screen that has 1920x1080 resolution has a surface of 1920x1080 pixels. Response times may specify the time it takes a pixel to change state from black-to-white-to-black. This also has something to do with AC voltage. Alternating current works with very rapid on/off cycles. Response is measured in milliseconds. In this case, the lower number means a better screen response. Typical LCD response times have been around 8 milliseconds. Newer LCD TVs now have pixels that operate lower than 5 milliseconds. Response times also affect motion blur and jitter. So if you play action games, connect to the PC, or watch action movies and sports, you're looking for the lowest response number possible.



How Big a Screen?


Space is often a consideration but most HDTV owners subscribe to getting the largest possible screen size you can afford.

How far do you plan to sit from the screen? This is a very important consideration. Remember those pixels that are on the screen? As screens increase in size so do the pixel sizes. So a 1080p 32-inch screen has smaller size pixels than a 60-inch screen. If you sit about 8 feet from a 60-inch screen, clarity may be compromised by the pixel size and your closeness to the screen. There are various calculators available to determine the best-sized screen for proper viewing distance. Here are our recommendations:

Screen SizeBest Viewing Distance
325 to 7 feet
377 to 8 feet
42 to 468 to 10 feet
50 to 5610 to 13 feet
60 to 6511 to 14 feet
70 and over13 to 20 feet

These recommendations are approximate guidelines.



Wall Mounts


Many people are eager to get TV onto their walls - almost like picture frames. There are some key things you should be aware of:

  1. Mount Compatibility

    Though many TV models are starting to follow a standard wall mounting format (VESA), several manufacturers still do not and require special dedicated mounts or adapters. VESA is short for Video Electronics Standards Association. It originated as a consortium to define standards in the computer industry. In 2003, VESA became active in designing mount standards for LCD and Plasma flat panel screens. VESA standards correspond to a number which specifies the space in millimeters between the TV mounting holes. Current standards are VESA 75, VESA 100, and VESA 200. VESA 400 is anticipated. VESA is also examining a mount called the DisplayPort that is expected to offer a more diversified mount to enable easier connection of various peripherals. Buying a TV that is VESA compatible means that it complies with a mounting standard and offers a wider choice of compatible mounts. It also allows easier installation.

    It's likely that your TV will have a standard VESA (Video Electronics Standards Association) hole layout. The VESA standard configuration might be given in inches (e.g., fits 3" x 3" or 4" x 4" VESA hole pattern) (e.g., fits VESA 75 or 100 or 200) where the hole pattern is 75 millimeters apart.

    Some mounts claim to be "Universal". Unfortunately, those universal standards may be manufacturer specific. It may include some VESA mounting holes as well as others. It's important to double check that your TV fits into the manufacturer's definition of universal.

  2. Where do all those wires go?

    Wall mounted TVs in store showrooms appear neat and clean. That's because all the wiring has been enclosed in the wall. Since many TVs share an antenna, cable connection, or video source, it's all wired in behind the mount. If you plan to connect your wall-mounted TV to a sound system or other peripherals, it is recommended that you discuss this with a qualified TV mount installer. You may want to wire everything inside the wall to some hidden junction box (at your baseboard, for example) to create a junction box onto which you can connect other devices. Needless to say, as you require more complex needs, expect higher installation costs. When doing inside-wall wiring, we advise asking installer if licensed to do so.

  3. Mounts for every size

    Not all mounts are compatible with your flat-panel's size and screen size or weight. Some flat-panel TV models have speakers at the bottom while others have them at the sides. This affects the overall size of the panel. So screen size alone is not the only factor determining the suitability of a particular wall mount. Weight of the panel also requires serious consideration. If you've a display that weighs 41 pounds, it is advisable to get a mount that can effectively hold 30 to 75 pounds instead of one that could hold 25 to 45 pounds. Both will probably do the job, but the one with the heavier capacity may be more structurally supportive. Determine whether the mount has uses a single or multiple stud mounting to the wall. Make sure your mounting hardware (screws, hangers) is designed to safely support all the weight of the mount plus your TV. You should also consider shifts in weight when using a movable mount.

  4. Fixed or Moveable Mounts

    A fixed mount keeps TV on wall in one fixed position. Moveable mounts may tilt the screen at different angles or even move it left or right on a hinge. These possibilities should be considered when deciding on your wall mount purchase. You should note, that as you move the screen from the wall, the wiring behind it might no longer be hidden at that position. Panel size is very important there to make certain that it can be moved easily with the mount. Moveable mounts are also called Articulating or Cantilever mounts. Some use arms to extend further into the room and at different angles.

There are several types of moveable mounts. Here are some of the popular types:

Tilt

The screen can move forward, tilting towards the floor, or backwards, tilting towards the ceiling. This type of motion is useful for screens mounted fairly high on a wall or above a fireplace.

Swivel or Pan

The screen can be turned to face towards the left or right, or around a corner. Perfect for mounting on kitchen cabinets, or in a room where your main seating doesn't face directly towards the TV.

Extension

The screen can be pulled out from the wall.



Home Theater - HDTV and Sound


Digital TV also adds refinements to sound. Many new TV shows are broadcast in 5-channel surround sound. That means there are separate channel for front - left, right, and center - and for rear - left and right. Blu-Ray, when you have a Blu-ray disc player, is capable of delivering up to 7 channels of surround sound.

While the sound of the television's speakers is usually very good, you're only receiving 2-channel stereo. You're missing the encompassing surround sound. Upgrading to 5 channels is really the best way to really start enjoying the more meaningful scope of what digital TV delivers.

5 Channels means 5.1 channels. There are 6 speakers. 3 are at the front and 2 are at the rear. The ".1" represents a powered subwoofer. The 5 speakers are usually very small and most can be hung on a wall. The subwoofer can be large, often the size of an end table, but doesn't need to be positioned in any defined spot. It's there to assure very low frequencies, like the movement of a truck or tractor, are heard accurately.

You can go through the component route and select your receiver and speakers individually. The better option, I believe, is to start with a complete home theater sound system. They are priced from about $300 to $2000. Generally, you can find a decent one for around $500. Each has a 5.1 channel amplifier, some have a DVD player, a few may have a Blu-ray player, and a radio. They all come with the required speakers, perfectly matched for uniform audio quality, with a supply of speaker wire. Some home theater audio systems may include (or have options for) rear wireless speakers.

It may be recommended that the sound system be the same brand as your TV. There are some built-in features that a "same brand" solution delivers. Sony uses Bravia. Panasonic uses Viera.



Connections


Televisions currently offer a variety of connections for DVD recorders and players, Digital Media players, digital-camera memory cards, computers, camcorders, and several audio/video components. Here's a list of popular connecting ports and their applications:

Analog Audio and Video

Sometimes referred as Composite or RCA jacks, these are among the oldest ports used for audio and video connections. Though they have high-performance abilities, they are not suggested for use in transmitting HDTV signals because they have limited bandwidth (capacity) for handling high information signals efficiently.

Component Video

This connection became popular when TV signals were capable to display in Progressive standards than the older Interlace (flicker) standards. The problem of transmitting color signals (of red, green, and blue hues) at a faster transmission rate for better images required greater bandwidth while complying with analog issues. Analog information isn't as succinct or detailed as digital so the component-video connection approximates for improved image integrity. Component video consists of three signals. The first is the luminance signal, which indicates brightness or black & white information that is contained in the original RGB signal. It is referred to as the "Y" component. The second and third signals are called "color difference" signals, which indicate how much blue, and red there is relative to luminance. The blue component is "B-Y" and the red component is "R-Y". The color difference signals are mathematical derivatives of the RGB signal. Green doesn't need to be transmitted as a separate signal since it can be inferred from the "Y, B-Y, R-Y" combination. The display device knows how bright the image is from the Y component, and since it knows how much is blue and red; it figures the rest must be green so it fills it in. These allow connection of video components such as DVD and Blu-ray but only to display in 720p or 1080i HDTV

DVI

(Digital Video Interface) was designed by leading computer manufacturers primarily to connect a computer to an LCD flat panel monitor. With the emergence of HDTV, the DVI found a presence on several LCD-based TV models. One drawback for DVI is the length of the connection. DVI is limited to about 20 feet. Longer connections may show evidence of signal degradation. Another drawback is that it is primarily suited for digital video. There have been several generations of DVI. DVI-A is used to send a digital signal to an analog display. DVI-D transfers uncompressed digital video. The DVI interface that you're likely to find is the DVI-I, which integrates the functions of the DVI-A and DVI-D. The reason why this computer based connection bears great significance on TV is that single-link DVI currently approaches optimal HDTV standards. DVI uses a digital information format called Transition Minimized Differential Signaling (TMDS). Single link cables use one TMDS connector, while dual link cables use two. A single link DVI connection can support a 1920 x 1080 image at 60fps. A dual link connection supports up to a 2048 x 1536 image. Yet DVI is associated with video performance. Another connector designed for HDTV connections, HDMI, also adds audio signal transfer into the mix.

HDMI

(High Definition Multimedia Interface) - was developed by a consortium of consumer electronics manufacturers. Among them, you'll find Sony, Panasonic, Toshiba, and RCA. It is one of the most recent connections and is geared for use with digital video and multichannel audio applications. Prior to HDMI, video connections and audio connections used several wires. HDMI integrates up to 8 channels of audio and digital video channels into one cable. In addition, HDMI is also fully compatible for connecting PC computers to compatible TV displays as it incorporates the Digital Visual Interface (DVI) standard. Based on copper cables (as opposed to optical fibers), HDMI makes few demands as to cable length and bend radius. Runs to 50 feet or more are very possible without loss of signal integrity.

Digital Media Slot

A reader that accepts memory cards used by digital cameras and camcorders. It allows easy viewing of photo and video images.

IEEE 1394

(also known as Firewire and as iLink) is a true digital connection originally designed for speedy data transfer using computers. At a maximum transfer rate of 800,000 bits of information per second, it is capable of transmitting video at progressive scan. It is used in many digital camcorders and some digital audio sources. It's less likely to be found as a television connector but you may find it where digital-camcorder connectivity is an issue.

USB

(Universal Serial Bus) is found on most computers, as well as digital-media players (MP3) and digital cameras. It is more common than Firewire and has the potential of slightly faster information transfer. Again, this connector is less common for use on an HDTV.

USB Wireless

A technology in evolution. It offers wireless connectivity for computer devices. It's mentioned here because it is likely that wires might be replaced for neater and more manageable connections. If this technology succeeds, it may be available for use in HDTV models around 2008.

Ethernet Networking

Some televisions have Ethernet networking capabilities. These allow access to outside video provider services. Household should have broadband Internet service and a router.



HDMI


HDMI represents High-Definition Multimedia Interface. This is the connection pathway to 1080p. Many televisions have several HDMI inputs. HDMI is the only way to upconvert DVD and other video sources for optimal view on a 1080p screen. HDMI offers more than any previous audio/video connect cable:

All Digital - No conversion or compression needed

Large Bandwidth - up to 10.2 gigabits per second, more than twice the bandwidth needed to transmit a 1080p signal, such as the output from a Blu-ray Disc player.

HDMI transmits all types of audio and video through one digital link, eliminating "cable clutter" by replacing as many as eleven older cables.

HDMI makes it easier to install to an all-digital home entertainment system.

HDMI makes it simpler to connect other HDMI compatible devices to your home theater system. PCs, gaming consoles, and video cameras can all be connected with the same one-plug convenience.

All HDMI versions are backward compatible to previous versions of HDMI .

Devices connected with HDMI have the ability to scan each other's capabilities and automatically configure certain settings. An HDTV and a DVD player, for instance, can auto-negotiate settings like resolution and aspect ratio to correctly match the format of the incoming content to the highest capabilities of the TV.

Consumer Electronics Control (CEC) is another intelligent HDMI feature set that provides for integrated, "one-touch" commands across multiple linked components. When enabled by the manufacturer, CEC allows system-wide behaviors such as one-touch play or one-touch record, where pressing a single button on a remote launches a series of coordinated commands.

Almost all electronic devices that plan to connect to an HDTV are adding HDMI to their list of connectors.



PC Connectivity


Almost all LCD and LED HDTV have a connection port to allow connectivity with a PC or a Macintosh computer. This lets you browse the web and explore other video opportunities from various websites and libraries. Many have an analog VGA connector while some also offer a DVI (Digital Video Interface) digital connector. A rising number of PC's have HDMI connectors which permit digital connectivity at full 1080p resolution.

LCD flat-panel displays offer the fastest response times for extreme graphics performance. If you'd like to use high-performance video and computer games, please choose a TV that has a screen response time of 20 milliseconds or less for best fast-action, gaming performance.



Summary


There are more commercial carriers (CableTV, Satellite TV, and Communication companies) setting up ways to feed HDTV to HDTV-capable television models. Almost all widescreen TV models have ATSC TV tuners that are capable of receiving free off-the-air HDTV broadcasts when you use an optional HD antenna. HDTV is accessible and all major TV broadcast networks are offering HDTV versions of, at least, major prime time shows.

As many HDTV capable TVs may also be used as PC monitors, there may actually be an eventual move when the PC will be integral to your home entertainment center. Then, of course, there's home-theater sound. Once you hear it, you'll never go back to listening to regular TV again.

It's all here, with more coming soon.





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