Magneto-optical head having heat sink layer

Abstract

A magneto-optical recording head comprises a magnetic coil formed on a lower surface of a transparent substrate opposed to a magneto-optical disk. A heat sink layer is provided at the outside of the magnetic coil on the lower surface. An objective lens is supported on an upper surface of the transparent substrate. The heat, which is generated by the magnetic coil, is released via the heat sink layer to the space between the magneto-optical disk and the substrate. The release of the heat is facilitated by the air stream which is generated by the rotation of the magneto-optical disk. The heat can be effectively released from the magnetic coil without inhibiting optical characteristics of the objective lens.

What is claimed is:  
     
         1 . An optical recording and reproducing apparatus for recording information on an information-recording medium, comprising: 
 a light source;    an optical head with which a light beam from the light source is radiated onto the information-recording medium to record the information; and    a detecting system which detects the light beam returning from the information-recording medium, wherein:    the optical head has a lens which collects the light beam onto the information-recording medium and a substrate on which the lens is supported;    NA of the lens is not less than 0.6; and    a projection which protects the lens is formed on the substrate on a side of the substrate facing the information-recording medium.    
     
     
         2 . The optical recording and reproducing apparatus according to  claim 1 , wherein a protective layer is formed on a surface of the projection.  
     
     
         3 . The optical recording and reproducing apparatus according to  claim 2 , wherein the protective layer is formed of silicon oxide, silicon nitride, zirconia, or diamond-like carbon.  
     
     
         4 . An optical recording and reproducing apparatus for recording information on an information-recording medium, comprising: 
 a light source;    an optical head with which a light beam from the light source is radiated onto the information-recording medium to record the information; and    a detecting system which detects the light beam returning from the information-recording medium, wherein:    the optical head has a lens which collects the light beam onto the information-recording medium and a substrate on which the lens is supported;    NA of the lens is not less than 0.6; and    a protective pad which protects the lens is formed on the substrate on a side of the substrate facing a surface of the information-recording medium.    
     
     
         5 . The optical recording and reproducing apparatus according to  claim 4 , wherein the protective pad is formed of resin.  
     
     
         6 . The optical recording and reproducing apparatus according to  claim 4 , wherein the protective pad covers four corners of the side of the substrate facing the information-recording medium.