| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an optical head which is compact and has inexpensive constitution and in which spherical aberration can be corrected highly accurately. <P>SOLUTION: In the optical head having an objective lens 7 converging a light beam emitted from a light source 1 on an optical recording medium 8, a spherical aberration correcting means 11 arranged at an optical path between the light source 1 and the objective lens 7 and provided with lens groups 11a, 11b correcting spherical aberration of the light beam, the spherical aberration correcting means 11 has a lens holder 12 holding at least one lens 11a out of the lens groups, a yoke 13 comprising a magnetic substance supporting the lens holder 12 movably in the direction of optical axis, coils 15a-15d attached to the lens holder 12, and magnets 14a, 14b attached to the yoke 13 so that a magnetic field operates to the coils 15a-15d, and the lens holder 12 is moved in the direction of optical axis by electromagnetic operation of magnets 14a, 14b by making current to flow through the coils 15a-15d, and then spherical aberration is corrected. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
