Patent ID: 7210152

Claim:
An optical head comprising: a laser light source; a collimator lens for converting a beam emitted from said laser light source into a parallel beam; a lens frame holding said collimator lens; a beam shaping device for shaping the parallel beam passing through said collimator lens; an objective lens for converging the parallel beam passing through said beam shaping device on an optical recording medium formed with a track; and a photodetector for detecting a reflected light or transmitted light from said optical recording medium, wherein said lens frame is designed to hold said collimator lens in such a manner that a straight line extending in a direction of the parallel beam having the largest ratio of the diameter of the parallel beam outgoing from said beam shaping device to the diameter of the parallel beam incoming into said beam shaping device at an entrance surface is located on the same plane together with a straight line extending in a direction along the displacement in a radial direction of said collimator lens.