Laser disc
A circular sheet carrier for recording audio signals by laser recording. Laser digital records are also called compact records and pocket records. Laser recording and playback is the result of the development of digital recording in the late 1970s. The diameter of laser digital record is 1.20 mm, and it can record on one side, and can play stereo programs at 1 hour with a dynamic range of 90dB. This kind of sound track with extremely high recording density is composed of pits and lands between pits recorded by laser beam according to signal coding. They represent binary 0 and 1 respectively. When playing a record, the binary number is scanned and picked up by a laser beam, and the whole playback equipment adopts a very precise servo control system to ensure good tracking. This disc has been erased and recorded again. Because CD has the advantages of high recording density, good sound quality, small size and easy storage, it is gradually replacing ordinary records and tapes as the main carrier of future audio signals.
Laser disc manufacturing technology
1877 The world's first phonograph was born in Edison's hands! It is the beginning of the development of audio-visual technology. People are not satisfied with the record player. In the early 1940s, Germany developed a tape recorder with high frequency offset and good mechanical transmission performance, which opened up a new channel for recording sound. By 1955, the American radio company announced the success of the experiment with a tape color video recorder, which can record its own and natural images. It has turned a new page in the history of audio-visual technology and opened the door and road for the development of modern audio-visual technology. Three years later, Ampek Company of the United States produced commercial color video recorders. 1970, the first black-and-white video disc was developed by Decca Company in England. Two years later, Philips in the Netherlands developed a color TV video disc with a laser pickup. This is the birth of modern laser disc!
The birth of CD and the application of laser in audio equipment are a revolution in audio. People use "light needles" instead of steel needles and gem needles to make laser discs. A CD can not only record, but also record. Optical discs are used to record and store sounds and images. It can be said that this is a revolution in audio-visual technology and a great pioneering work.
Since the appearance of CD, people have fully tapped its potential and created multifunctional CD players and records. 1983, the United States and Japan developed brand-new digital recordings respectively. This kind of record completely got rid of the traditional way of making and replaying records, and opened up a brand-new realm for records. This kind of digital recording is of great use in storage technology.
With the rapid development of laser disc technology, new records and records with various functions and uses emerge one after another. Therefore, laser disc, computer technology and audio-visual technology have joined hands to enter the field of document storage and retrieval. Information is stored on CD-ROM, and the required information can be quickly retrieved, consulted and printed. Now CD-ROM books have entered family life.