Optical head having semiconductor laser

An optical head for reading information simultaneously from a plurality of tracks on an optical record medium by projecting a slit-shaped light spot comprising:

• a semiconductor laser for emitting a laser beam having a substantially elliptical cross section;
• a first optical system for converting said laser beam emitted from the semiconductor laser into a laser beam which is parallel along a track direction in which said information tracks extends and is non-parallel along a direction perpendicular to said track direction;
• a second optical system including an objective lens for projecting said laser beam emanating from said first optical system onto said optical record medium as a slit-shaped laser spot such that a longitudinal direction of the slit-shaped laser spot is substantially aligned with a direction perpendicular to said track direction and a plurality of information tracks are simultaneous illuminated, said second optical system forming images of said simultaneously illuminated plurality of information tracks;
• a photodetector having a plurality of light receiving elements each of which receives respective one of said images of a plurality of information tracks to derive a plurality of information signals;
• and
• a light distribution uniformizing means arranged between said semiconductor laser and said objective lens for extracting a portion of the laser beam impinging upon said objective lens, said portion having a substantially uniform distribution in an amount of light along a direction which is substantially perpendicular to said track direction, said light distribution uniformizing means comprising a stop arranged between said light source and said objective lens, wherein said stop has a circular aperture whose diameter is slightly shorter than a dimension of the elliptical laser beam along a direction of a minor axis thereof.