The LaserDisc Video Format
LaserDisc (LD) is the grandfather of optical disc storage media. The underlying technology was proposed in 1958 (by David Paul Gregg) and patented in 1961 and 1969. During it's development it was known as Reflective Optical Videodisc System and Disco-Vision.
Philips and MCA teamed up to produce LaserDiscs in the 1970s, launching the first commercial model in 1978. The format found favour amongst serious enthusiasts and provided many of the features of DVD, years ahead of it's time.
However LaserDisc had drawbacks which kept it from becoming mainstream:
- It could only playback, not record.
- The discs were large and inconvenient.
- The discs could only hold about an hour of video. Although some players could automatically flip the laser to play the second side (making a total of two hours), this was still too short for a movie.
LaserDisc was more popular in Japan, thanks in part to collectors of Anime content.
LaserDisc used very similar technology to CDs and DVDs. The most obvious difference is that the video signal was not digital — it was analogue using frequency modulation (FM).
The disc looked like a DVD but much larger at 30cm (12 inches) in diameter. The disc had two sides made of stamped aluminium glued between plastic sheets.
LaserDiscs included chapters which are similar to DVD chapters.
See also: Other video formats