Laserdisc

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Contents

History

Laserdisc Is Here!

Early optical Laserdisc technology was invented by David Paul Gregg in 1958. By the time Gregg had patented his transparent videodisc system in 1961 and again in 1969 he decided to sell the patents to electronics manufacturer Philips. Philips had already been working on a reflective videodisc system at the time and gaining ownership of Gregg’s invention helped them push technology forward. Philips’ main goal with the Laserdisc was to sell feature films on them to consumers, so they teamed up with MCA, an entertainment company that owned the rights to the largest catalog of films at the time, to bring the Laserdisc technology to market. Collaboratively, Philips and MCA demonstrated the technology in 1972 and made it available for consumers on December 15, 1978. Philips manufactured the hardware players and MCA made the discs. The format went by many names including DiscoVision, but most referred to it as Laserdisc. The first Laserdisc title to release in North America was Jaws (1978); the two last titles were Paramount’s Sleepy Hollow and Bringing out the Dead in 2000. Laserdiscs continued to sell in Japan until the end of 2001. In the mid-1980s Pioneer Electronics purchased the format from Philips and MCA and would go on to manufacture Laserdisc players until 2009. One of the latest hybrid players could read LD, DVD, and CD. CNET reported the format’s death on January 16, 2009. However, discs can still be purchased today; the Laserdisc Vault has a wide variety of genres to choose from.

Disc Technology

Laserdisc

Video and audio are stored on a Laserdisc (LD) as an analog signal. Just like a compact disc (CD) the surface of a LD is covered with pits and lands but it uses frequency modulation of an analog signal, not digital. Pits are essentially tiny indentations on a disc that store the data and lands are the areas between them. The discs themselves are 12 inches in diameter, about the size of a LP record, and they were made up of two single-sided discs glued together. The format would evolve to eventually replace mono audio with digital stereo sound support.

Two major encoding formats based on a disc’s rotation speed were implemented. (1) CLV (Constant Linear Velocity) was known as Extended Play to consumers and these discs were the most popular because they could store 60 minutes of video per side. A slow rotational speed of 1800-600rpm allowed for more storage space. Movies with a runtime of 120 minutes or less had no trouble fitting on these discs. (2) CAV (Constant Angular Velocity) was known as Standard Play to consumers and these discs were not as popular for mainstream consumers because they could only store 30 minutes of video per side. The frames of CAV discs correspond to actual film frames, and a faster rotational speed allowed owners to play around with unique features like pause, frame-by-frame advance, freeze frame, and variable slow motion. These discs usually stored movie extras or bonus material because of its smaller storage capacity. Since these discs gave the user the ability to reference content frame-by-frame, they proved to be a hit with film students and critics. Pioneer experimented with higher capacity discs that could hold up to 70 minutes of content but they never made it to market.

Hardware

Magnavision

Up until the mid-1980s Laserdisc players used Helium-neon laser tubes to read discs, and when Pioneer came along they adopted consumer players with solid-state lasers. Unlike the older players like the Magnavox Magnavision, Pioneer’s new models featured front-loaders instead of top-loaders for discs. The solid-state laser diode players had many advantages over the older players. For example, they featured a tilt-servo mechanism that physically tilted the player’s laser table base so that it would stay parallel with the disc at all times, even if an external vibration source sat below the player.

The majority of players only supported single-sided playback, meaning owners were forced to get up and manually turn the disc over to watch content when one side finished playing. Towards the end of its run, some LD players were able to automatically make the switch; when one side ended the player would reverse the direction of the disc’s roation, move the laser head to the proper side of the disc, and resume playback.

Ports-wise, LD players included S-Video and composite outputs.

Modern LD Player

Starting in the late-1980s into the 1990s, Pioneer and other manufacturers starting making LD combination players that could read LD, CD, and DVD formats. In 1992, Sony invented the Muse Laserdisc format for the Japanese market. Also known as Hi-Vision, the Muse format boasted high-definition video playback and required a 16x9 aspect ratio and a dedicated Muse player.

Advantages & Disadvantages

VHS & DVD

During its time on the market, Laserdisc went head-to-head with VHS competing to become the first widely adopted standard for home entertainment. LD had a far superior picture over VHS (400 horizontal lines vs. 250 lines), random access allowed owners to quickly navigate to any point on the disc (as opposed to rewinding a cassette tape, which is a lengthier process), and discs could carry four audio channels making room for “special edition” releases that included commentary tracks in addition to the movie. During the later part of its lifecycle, LD also competed against the newly adopted DVD format. Since LD video is not digital like DVD, it did not experience playback issues such as artifacting and color banding. LD supporters say that Laserdiscs maintain a smoother image, while DVDs come off as more artificial.

LD disadvantages were obvious. The physical Laserdisc was huge in size, fragile, and heavy compared to VHS and DVD. LDs could only hold 30 to 60 minutes of content. Storage capacity was inferior to the competition; VHS could hold up to 3.5 hours of video and today DVDs can store anywhere from 4.7 to 9.4GB of data. Other LD problems include laser-rot and crosstalk. Due to manufacturing issues, some Laserdiscs sold with their 2 sides glued together incorrectly; this caused discs to “laser-rot”, or delaminate and allow oxygen to seep in and eat away at the reflective metallic parts of the disc. Crosstalk, or distorted video playback, happened when the laser inside a player accidentally picked up the picture on an adjacent track. The biggest disadvantage of all was that all Laserdiscs could only playback content and could not be recorded on. This is a staple feature of the video cassette tape and DVD formats.

Other uses

The Laserdisc format was more popular in Japan than it was in North America because it was a big force in the anime market. Collectors of anime content helped drive the sales of the format in Japan.

The instant-seeking functionality of Laserdiscs allowed developers to create interactive video games for LD players. The most popular LD game was Dragon’s Lair and it used pre-recorded animated scenes to tell a story. A user would use a remote or joystick to command the story to move forward and make decision for the on-screen characters. Gameplay was similar to current RPGs.

Legacy

Although Laserdisc is a dead format today, it was a major stepping stone for the industry to reach modern technologies such as the CD, DVD, and MiniDisc. Many of David Paul Gregg’s early patents were licensed by companies to create these formats we know today.

References

http://moesrealm.com/home-theater/guides/laserdisc-guide/

http://www.wordiq.com/definition/Laserdisc

http://www.laserdiscplanet.com/

http://www.mediacollege.com/video/format/laserdisc/

http://www.mediacollege.com/video/format/laserdisc/patents.html

http://www.ehow.com/about_5336010_laserdisc-history.html

http://www.gizmohighway.com/history/laserdisc.htm

http://news.cnet.com/8301-17938_105-10144431-1.html

http://www.thedoteaters.com/p2_stage6.php

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