Optical pickup for high-density recording/reproducing

An optical pickup for high-density recording/reproducing, comprising:

• a light source for generating a light beam;
• a collimating lens for collimating the generated light beam to form a collimated light beam;
• a first slit member with an aperture for passing the collimated light beam therethrough, thereby to restrict the diameter of the collimated light beam to a predetermined diameter;
• an objective lens, for focusing the collimated light beam which has passed through the aperture of said first slit member, which comprises a first portion for transmitting a zero-order light of reflective beams which are generated by being diffracted and reflected by a light-recording medium in parallel, and second and third portions for respectively transmitting at least a portion of each .+-.1st-order diffracted light components which are diffracted in a jitter direction of the reflective light beams, wherein said first, second and third portions do not overlap;
• a first beam splitter for reflecting the collimated light beams which have passed through the aperture of said first slit member toward said objective lens, and also for transmitting straight through the reflective light beams which have passed through said objective lens;
• a second beam splitter for reflecting a portion of the reflective light beams while transmitting straight through a remainder thereof, in order to divide a light amount of the reflective light beams transmitted straight through said first beam splitter;
• a first focusing lens for focusing the zero-order optical component and .+-.1st-order diffracted optical components of the portion of the reflective light beams reflected by said second beam splitter so as to mutually interfere;
• a first optical detector for receiving the zero-order optical component and .+-.1st-order diffracted optical components of the reflective light beams focused by said first focusing lens and for detecting a signal for reproduction of information recorded on said light-recording medium;
• a second slit member having an aperture for passing the remainder of the zero-order optical component of the reflective light beams transmitted straight through said second beam spitter and intercepting the remainder of the .+-.1st-order diffracted optical components thereof;
• a second focusing lens for focusing the zero-order optical component of the reflective light beams which have passed through the aperture of said second slit member;
• an edge prism for reflecting a portion of the zero-order optical component of the reflective light beams focused by said second focusing lens, and passing a remainder thereof;
• a second optical detector for receiving the zero-order optical component of the reflective beams reflected by said edge prism and for detecting a signal for informing a track location of said objective lens;
• and
• a third optical detector for receiving the zero-order optical component of the reflective light beams which have passed through said edge prism and for detecting a signal for informing a focus location of said objective lens.

An optical pickup for high-density recording/reproducing, comprising:

• a light source for generating a light beam;
• an objective lens for focusing the light beam on a light-recording medium;
• and
• an optical detecting mechanism including a plurality of focusing lenses which focus optical components of reflected light beams, and a plurality of optical detectors which detect optical signals by receiving optical components of reflected light beams diffracted and reflected by the light-recording medium,
• wherein said objective lens includes a first portion for transmitting a zero-order optical component of the reflective light beams and second and third portions for respectively transmitting at least a portion of each .+-.1st-order diffracted optical components of the reflective light beams.