Apparatus for generating seek direction detection signal

An apparatus for use with an optical disc:

• a light source;
• an optical branching unit branching incident light into a main light beam and a sub-light beam, forming a main light spot and a sub-light spot, the sub-light spot comprising optical aberration in a radial or tangential direction of the optical disc;
• a main photodetector comprising a plurality of receiving portions receiving and photoelectrically converting the main light beam reflected from the optical disc;
• a sub-photodetector comprising a plurality of receiving portions receiving and photoelectrically converting the sub-light beam reflected from the optical disc;
• a track error signal detector detecting a track error signal from the receiving portions of the main photodetector;
• a track cross signal detector processing output signals from the receiving portions of the main photodetector and from the receiving portions of the sub-photodetector to detect a track cross signal;
• and
• a signal processor comparing the track error signal with the track cross signal to detect a seek direction.

An apparatus for use with an optical disc:

• optical branching means for irradiating a main light beam and a sub-light beam, wherein the sub-light beam comprises an optical aberration in a direction on a track of the optical disc;
• photodetecting means comprising a plurality of portions for receiving and processing the main light beam and a plurality of portions receiving and processing the sub-light beam;
• track error signal detecting means for detecting a track error signal from the portions receiving the main light beam;
• track cross signal detecting means for detecting a track cross signal from the portions receiving the main light beam and from the portions receiving the sub-light beam;
• and
• signal processing means for comparing the track error signal with the track cross signal to detect a seek direction of a light spot formed on the optical disc.

An apparatus for use with an optical disc:

• a light source;
• optical branching means for branching incident light into a main light beam and a sub-light beam, forming a main light spot and a sub-light spot, the sub-light spot comprising optical aberration in a radial or tangential direction of the optical disc;
• main photodetecting means comprising a plurality of receiving portions for receiving and photoelectrically converting the main light beam reflected from the optical disc;
• sub-photodetecting means comprising a plurality of receiving portions for receiving and photoelectrically converting the sub-light beam reflected from the optical disc;
• track error signal detecting means for detecting a track error signal from the receiving portions of the main photodetector;
• track cross signal detecting means for processing output signals from the receiving portions of the main photodetector and from the receiving portions of the sub-photodetector to detect a track cross signal;
• and
• signal processing means for comparing the track error signal with the track cross signal to detect a seek direction.