About Record Disk
A record is a kind of the media which recorded sound information, including music etc., on disk-like resin etc. by mincing unevenness, and refers to the thing in which the information on sound was actually recorded. It may be called a record. A record player and a needle are used for reproduction of sound. With rotation of a record, unevenness of the slot minced by the record will give vibration to a needle, it will be changed into an electric signal, and sound will be uttered from a speaker through an amplification circuit. It was reproduced with the gramophone before the appearance of a record player. In recent years, if there is also a player (laser turntable) which carries out non-contact reproduction not using a needle but using laser and this is used, the broken board and a board with a crack are also renewable. The origin of a word is English "record" of the meaning "record." It is called an analog record, an analog disk, etc. so that it may not be mixed up with the meaning of "record." It may call by SP-LP gas-EP and a standard, may be called 78 rotations, 45 rotations, 33 rotations, and 16 rotations by rpm (number of rotations), or may call in the size of 7 inches, 10 inches, 12 inches, and a board.