Recording and/or reproducing apparatus for using magneto-optical disc

Abstract

A magneto-optical disc recording and/or reproducing apparatus having an external magnetic field generating means for supplying an external magnetic field to a magneto-optical disc, a spacer sheet disposed relative to the magneto-optical disc at its surface side opposing to the external magnetic field generating means and a moving means for moving the external magnetic field generating means in the direction in which the external magnetic field generating means is isolated from and brought in contact with the magneto-optical disc, in which the moving means moves the external magnetic field generating means to the position at which the external magnetic field generating means comes in contact with the magneto-optical disc via the spacer sheet when an information signal is recorded on the magneto-optical disc, whereas the moving means moves the external magnetic field generating means to the position distant from the magneto-optical disc when the information signal recorded on the magneto-optical disc is reproduced.

I claim as my invention: 
     
       1. A magneto-optical disc recording and reproducing apparatus comprising: (a) an optical recording and reproducing head for recording and reproducing signals on a magneto-optical disc;   (b) external magnetic field generating means for supplying an external magnetic field to the magneto-optical .Iadd.disc and used to record signals on the magneto-optical disc with the optical .Iaddend.recording and reproducing head .[.is recording signals on the magneto-optical disc.].;   (c) a spacer .[.sheet disposed relative to the magneto-optical disc at its surface side opposing to the external magnetic field generating means.]. .Iadd.means provided between the external magnetic field generating means and a surface of the magneto-optical disc opposing to the external magnetic field generating means.Iaddend.;   (d) wherein the external magnetic field generating means is movable and is positioned at a first position which is distant from the magneto-optical disc and the spacer .[.sheet.]. .Iadd.means .Iaddend.when the optical recording and reproducing head is reproducing signals from the magneto-optical disc and at a second position at which the external magnetic field generating means comes in contact with the magneto-optical disc .[.via.]. .Iadd.through .Iaddend.the spacer .[.sheet.]. .Iadd.means .Iaddend.when the optical recording and reproducing head is recording signals on the magneto-optical disc; and   (e) moving means for moving the external magnetic field generating means between the first position and the second position and keeping the external magnetic field generating means distant from the magneto-optical disc and the spacer .[.sheet.]. .Iadd.means .Iaddend.when the information signal recorded on the magneto-optical disc is reproduced.   
     
     
       2. A magneto-optical disc recording and reproducing apparatus according to claim 1, wherein the external magnetic field generating means is unitarily coupled to the optical recording and reproducing head disposed across the magneto-optical disc and can be freely moved in the radial direction of the magneto-optical disc in unison with the optical recording and reproducing head. 
     
     
       3. A magneto-optical disc recording and reproducing apparatus according to claim 2, wherein the moving means is disposed so as to become movable in the radial direction of the magneto-optical disc in unison with the external magnetic field generating means. 
     
     
       4. A magneto-optical disc recording and reproducing apparatus according to claim 1, wherein the external magnetic field generating means is comprised of a pivotally mounted arm member and an external magnetic field generating unit provided on a free end side of the arm member and wherein the arm member raises and lowers the magnetic field generating means relative to the spacer .[.sheet.]. .Iadd.means.Iaddend.. 
     
     
       5. A magneto-optical disc recording and reproducing apparatus comprising: (a) an optical head for recording signals on a magneto-optical disc and reproducing signals from the magneto-optical disc;   (b) external magnetic field generating means for supplying an external magnetic field to the magneto-optical disc whereby signals are recorded on the magneto-optical disc by the external magnetic field generating means and the optical head, the external magnetic field generating means being arranged on one side of the magneto-optical disc which is opposite to the optical head and wherein the external magnetic field generating means is positioned coaxially with respect to the optical head;   (c) spacer means for generating a distance between the magneto-optical disc and the external magnetic field generating means, the spacer means being provided on a surface of the one side of the magneto-optical disc, the spacer means being contacted by the external magnetic field generating means;   (d) wherein the external magnetic field generating means is movable and is positioned at a first position which is distant from the magneto-optical disc and the spacer means when the optical head is reproducing signals from the magneto-optical disc and at a second position at which the external magnetic field generating means comes in contact with the magneto-optical disc via the spacer means when signals are being recorded on the magneto-optical disc;   (e) an arm member for supporting the external magnetic field generating means, the arm member being movable between the first position and the second position; and   (f) moving means for moving the arm member between the first position and the second position and keeping the external magnetic field generating means distant from the magneto-optical disc and the spacer means when the signals recorded on the magneto-optical disc are reproduced.