Optical disk apparatus and optical head

An optical disk apparatus, comprising:

• an optical head including a finite conjugate optical system for converging diffused light emitted from a light source onto an optical disk to thereby perform at least data writing, said optical head including a beam spitter for leading the diffused light emitted from the light source to an objective lens and a .lambda./4 polarization plate for polarizing the light on an optical path between the beam spitter and the objective lens;
• means for rotating said disk;
• means for suppressing disk displacement of said disk taking place in accompanying said rotation of the disk;
• means for accommodating said disk holding data at a location bearing a predetermined relation to said head;
• and
• a drive circuit for controlling operations of said optical head and said rotating means.

An optical disk apparatus, comprising:

• an optical head including a finite conjugate optical system working on a rotating optical disk holding data, said disk undergoing displacement not greater than 0.25 mm during rotation, said optical head performing at least data writing on said disk by converging diffused light from a light source through a lens, wherein a working distance between said lens and said light source being 5 to 20 mm;
• means for rotating said disk;
• and
• means for accommodating said disk at a position bearing a predetermined relation to said head.

An optical disk apparatus, comprising:

• an optical head including a finite conjugate optical system working on a rotting optical disk holding data, said disk undergoing disk displacement not greater than 0.25 mm during rotation, said optical head performing at least data writing on said disk by converging diffused light from a light source through a lens having a diameter of 1 to 4 mm to thereby illuminate said disk with 25 to 50% of the light emitted from said light source for performing at least data writing operation onto said disk;
• means for rotating said disk;
• and
• means for accommodating said disk at a position bearing a predetermined relation to said head.

An optical disk apparatus, comprising:

• an optical head including a finite conjugate optical system for performing operation on a rotating optical disk holding data, said disk undergoing disk displacement not greater than 0.25 mm during rotation, said optical head performing at least data writing operation on said disk by converging diffused light from a light source through a lens located at a working distance in a range of 0.25 to 1.0 mm from said light source;
• means for rotating said disk;
• and
• means for accommodating said disk at a position bearing a predetermined relation to said head.

An optical disk apparatus, comprising;

• an optical head including a finite conjugate optical system for performing operation on a rotating optical disk holding data, said optical head performing at lest data writing on said disk by converging diffused light from a light source through a single objective lens having a numerical aperture of 0.5 to 0.6 and a working distance of 0.25 to 1.0 mm from the light source;
• means for rotating said disk;
• and
• means for accommodating said disk at a position bearing a predetermined relation to said head.