Hitherto, there have been proposed magneto-optical recording/reproducing apparatuses adapted to selectively use, as a recording medium for information signals, the magneto-optical disc capable of carrying out overwrite recording of information signals and the reproduction only (type) optical disc.
The magneto-optical disc or the optical disc used for a magneto-optical recording/reproducing apparatus as described above is accommodated within the disc cartridge in order to prevent damage of at least the signal recording surface and/or attachment of dust thereto, and is loaded into the magneto-optical recording/reproducing apparatus in the state where it remains to be accommodated within the disc cartridge.
The magneto-optical recording/reproducing apparatus (unit) using the disc cartridge comprises holder for holding the disc cartridge, and is adapted so that this holder is rotated from the rising position for carrying out insertion or ejection of the disc cartridge toward the falling position side for carrying out recording and/or reproduction with respect to the magneto-optical disc within the disc cartridge, whereby the disc cartridge inserted and held within the holder is loaded into the recording/reproduction unit.
The recording/reproduction unit for carrying out recording and/or reproduction with respect to the magneto-optical disc within the disc cartridge comprises a magnetic head disposed above the holder and adapted to be rotated following rotation of the holder, and an optical head disposed at the position opposite to this magnetic head. Further, at the recording/reproduction unit, there is provided a cartridge loading section within which disc cartridge held within the holder is loaded after undergone positioning, and there is provided a disc rotational operation mechanism for allowing the magneto-optical disc or the optical disc accommodated within the disc cartridge loaded at the cartridge loading portion to undergo rotational operation.
In order to carry out recording of information signals such as music signal, etc. by the magneto-optical recording/reproducing unit constituted as described above, the disc cartridge within which the magneto-optical disc which permits overwrite recording of information signals is accommodated is held into the holder to rotate this holder toward the falling position side where recording and/or reproduction of information signals are carried out with respect to the magneto-optical disc to allow the disc cartridge to undergo loading with respect to the cartridge loading portion. When the disc cartridge is loaded with respect to the cartridge loading portion, the magneto-optical disc accommodated within the disc cartridge is clamped with respect to the disc rotational operation mechanism. At this stage, the disc rotational operation mechanism is driven to allow the magneto-optical disc to undergo rotational operation, and to allow the magnetic head and the optical head to undergo movement operation in the radial direction of the magneto-optical disc in a manner synchronous with each other. Then, light beams emitted from the optical head are irradiated onto the magneto-optical disc caused to experience rotational operation to heat the portion where light beams have been irradiated so that its temperature becomes equal to the Curie temperature or more, and to apply, to the heated portion, external magnetic field which has been magnetically modulated in accordance with information signal to be recorded from the magnetic head. Thus, recording of desired information signal is carried out.
Meanwhile, the magnetic head disposed above the holder and rotated along with the holder is caused to become close to the magneto-optical disc in a manner to slidably come into contact therewith when recording of information signals is carried out with respect to the magneto-optical disc.
Moreover, when reproduction of information signals recorded on the magneto-optical disc or the reproduction only type optical disc accommodated within the disc cartridge is carried out, since it is unnecessary to apply external magnetic field onto the magneto-optical disc or the optical disc, the magnetic head is moved to the position spaced from the magneto-optical disc or the optical disc. Also when the recording/reproduction unit is in stopped state where no recording of information signals is carried out, the magnetic head is moved to the position spaced from the magneto-optical disc.
When there is no necessity of using the magnetic head as described above, the magnetic head is moved to the position spaced from the magneto-optical disc, etc. in order to prevent abrasion of the magnetic head, or the magneto-optical disc or the optical disc.
Meanwhile, since the magneto-optical discs or the optical discs can carry out high density recording of information signals, discs of which diameter is caused to be small are used. For example, magneto-optical discs or optical discs of which diameter is caused to be about 64 mm are used. Magneto-optical recording/reproducing units themselves using such magneto-optical discs or optical discs which have been compact as recording medium are caused to become compact. Thus, magneto-optical recording/reproducing units which have been compact into portable size are proposed.
In the magneto-optical recording/reproducing units permitted to undergo carrying (caused to be portable) of this kind, realization of thinner thickness and more compact structure is required in order to improve convenience of portability.
Meanwhile, in order to realize thinner thickness structure of the magneto-optical recording/reproducing unit, it is conceivable to reduce movement quantity of the magnetic head which comes into contact with the magneto-optical disc caused to undergo rotational operation by the disc rotational operation mechanism or becomes away therefrom.
However, in magneto-optical recording/reproducing units in which the magnetic head is disposed above the holder for holding the disc cartridge, when the movement quantity of the magnetic head is simply reduced, a portion of the magnetic head is placed in the state close to the portion within the holder when the holder is rotated so that it is located (placed) at the position where insertion or ejection of the disc cartridge is carried out. For this reason, there is the possibility that when insertion/withdrawal of the disc cartridge is carried out with respect to the holder, a portion of the disc cartridge may come into contact with the magnetic head to damage the magnetic head.
In addition, when the holder and the magnetic head are close to each other, there is also the possibility that in such cases that impact is applied to the magneto-optical recording/reproducing unit, the magnetic head may come into contact with a portion of the disc cartridge so that it is damaged.