Portable DVD Player Buying Guide

Benefits of a DVD Player (back to top)

Fed up with the regular fungus attacks that Video Home System (VHS) cassettes are prone to? Don't want to go to the movie theater to catch a movie after a hard days work and relax at home with a high quality reproduction of your favorite flick?

The DVD player, launched in 1996, is now the panacea for all celluloid ailments. The DVD, even though it is sized the same as a normal CD has a much greater storage capacity. A single sided, single layer DVD can store 4. 5 Gigabytes (GB) of data while a double layered, double density DVD can contain as much as 17 GB of data. This immense storage capacity allows as many as five full length movies to be stored on a single DVD along with footage of the shooting process, background facts of the included movies, and even interviews with the director and the stars - a treat for any movie fan.

Built-in LCD screens provide the viewer with the freedom to watch movies at anyplace and anytime, even while traveling. Most DVD players are backward compatible and can play audio CDs and even Video CDs (VCDs).

The biggest drawback of DVD players is the region code, which has been eliminated in certain new DVD players. This implies usage of a 'Region 0', which enables the player to be compatible with a DVDs from all six regions. Thus, almost any DVD from anywhere in the world can be played on these players.

In order to understand how DVD players function, we would need to get familiar with the media from which data is read by the player, the DVD, and the way data is written onto the disc. A DVD has the same diameter and thickness as a conventional CD and is also composed of the same materials, which are multiple layers of polycarbonate plastic. Data is written onto the DVD in the form of miniscule bumps or pits running in a single spiraling track from the center of the disc radiating towards the outer edge on each layer. After the bumps are created, a thin reflective material is spread over the surface, with aluminum being used beneath the inner layers and reflective gold coating the outer layers. This infrastructure permits the laser head of the DVD player to reach the inner layers. After completion of all the layers, each is exposed to infrared light after receiving a coating of lacquer. Now is the time for the label of the DVD to be printed. In single sided discs, the label is printed on the non-readable side, while in double sided discs the label is printed on the small non-readable patch near the center hole.

Now, when the DVD is inserted into the drive of the DVD player, a laser beam is focused on the surface of the disc to read the bumps. The video data, which is commonly Moving Picture Expert Group-2 (MPEG-2) encoded, is decoded into a recognizable video signal. The audio data too is passed through a Dolby or a DTS decoder and transmitted to the speakers after amplification.

Taking into consideration the infinitesimally small size of the data track, having a pitch of around 700 nanometers, along with the length of a particular bump being approximately 440 nanometers, it goes without saying that the reading head of the DVD player has to be extremely sensitive. This requires precision and perfect coordination between the three key components mentioned below:

• Drive Motor: This is the motor that is responsible for rotating the disc. Rotational speeds vary between 200 to 500 rpm, depending on the track being read.

 

• Lens and Laser Apparatus: The light beam from this laser emitter has a wavelength of around 640 nanometers which enables the laser to detect even the smallest bumps.

 

• Tracking Assembly: This is the mechanism that moves the laser apparatus along the spiral track of the DVD. This movement happens in increments of microns.

We will now take a look on how the data on the DVD is interpreted by the player. The laser beam that bypasses the polycarbonate layer of the DVD and gets reflected from the reflective layer beneath is detected by an opto-electronic contraption, which is sensitive to light intensity variations. Thus, the light reflected from the bumps is read differently than that reflected from flat surfaces. These variable light readings are converted into digital format consisting of the binary numbers 0 and 1.

To ease the movement of the laser apparatus, those DVDs which incorporate a second layer, have the data track starting from the edge of the disc moving towards the middle. Thus, the laser head can start reading the bumps continuously after finishing the first layer, without having to move to the center again for the second layer.

With a wide array of DVD players available in the market today, it can be a time consuming and tedious process choosing the player you want. Listed below are a few points you need to consider when making a purchase of this versatile machine:

• Multi-Region Compatibility: As mentioned earlier, this is one of the most important parameters you need to consider when buying a DVD player, as you would not want to get stuck with a player that will not play all DVDs. A multi-region DVD player is the safest option, ensuring that no DVDs you buy or rent will go to waste due to incompatibility. This is all the more relevant if you have friends or relatives in foreign countries that may send you DVDs, or if you are a frequent traveler.

 

• Single Disc Player or Multi-Disc Player: A single disc player plays only one disc at a time, while a multi disc player can store 5, 50, 100 or even as many as 403 discs at a time. For a normal home user, a single disc or a 2 to 3 disc player is sufficient. The DVD players having greater disc capability are normally used as DVD jukeboxes in restaurants and other public places.

 

• DVD Players with a Built-In LCD Screen (Portable DVD Players): This option is suitable for those users who intend to use their players outdoors or while traveling. With a built-in screen of approximately 10 inches or more, these players are a beneficial for movie buffs on the go.

 

• Compatibility with your Television: Before purchasing, it is necessary to confirm that your DVD player is compatible with your television. This depends on the inputs provided by both your television and the DVD player. Below are listed a few of the commonly used connectivities:

 

• S-Video: The separate video (S-video) output mode splits the video data into two separate analog signals.

 

• Composite Video: This connectivity enables transmission of analog signals between the television and devices such a game console, video cassette player, as well as the DVD player. The three pronged cable consists of the yellow female RCA jack and two red and white audio jacks.

 

• Component Video: The output from this connectivity is of superior quality and if your television can support this input, it is advisable to go in for a DVD player having component video outputs. This connectivity requires three RCA jacks, colored: red, green, and blue.

 

• Coaxial Digital Output: The audio output from this connectivity is of good quality and is suited if you happen to have a Dolby Digital receiver.

 

• Stereo Output: This is applicable for televisions having two speakers.

 

• 5. 1 Channel Output: This output, using the Dolby Digital technology, offers 5 full bandwidth channels. These are: the front-left, front-right, middle, surround left, and surround right. Low frequency bass output is provided by a subwoofer. DVD players having the 5. 1 channel output have built-in Dolby Digital decoders as well as a DAC to convert digital output to an analog signal.

 

• Remote Control: A remote control is a very user friendly accessory that enables you to control the DVD player from across the room without needing to get up and walk towards the player. Almost all the functions of the system can be utilized through the remote control.

 

• Size: Depending on the space available to place your DVD player as well as whether you intend to carry the device around, the dimensions of the player needs to be considered prior to your purchase.

3. Making the Decision (back to top)

After analyzing your requirements and preferences with regards to the various features mentioned above, you should compare various DVD players in the market that match those requirements offered by leading brands at a comparison shopping site such as www.smarter.com. A DVD player is one of the most advanced audio and video output devices today and buying one requires careful consideration. It is advisable to examine the features of players from different brands as well as consult with friends who already own a DVD player to help you reach your decision.

Service is of paramount importance for any sophisticated electronic gadget as well as the warranty offered by the manufacturer. We also suggest that you read the instruction manual thoroughly as it is a known fact that maintenance and usage of the device plays a big part in ensuring long life and trouble free performance.

Buying a good DVD player requires investment of a reasonable amount of time in researching and evaluating the various contenders. The trick is to strike the perfect balance between price and functionality and the best way to begin is to find out exactly what your needs are. Hopefully now you have more information to help make your purchasing decision more informed, now go find a great DVD player!