Patent ID: 7126889

Claim:
A tracking error detector being a tracking error detector for detecting a positional error in the radial direction perpendicular to the track direction of a beam spot on a recording plane of an optical disk as a tracking error, comprising: a photo-detection circuit which receives a beam of light reflected by the signal recording plane of the optical disk using a first and a second set of light receiving areas provided in inverse phases and outputs multiple electric signals according to the light intensities of the light beam reflected at the light receiving areas of the respective sets, bottom envelope detection circuit which detect bottom envelopes of the multiple electric signals and generate multiple bottom envelope signals representing the waveforms of the respective bottom envelopes, a first adding circuit which takes the sum of the multiple bottom envelope signals obtained from the first set of light receiving areas in order to generate a first added signal, a first adding circuit which takes the sum of the multiple bottom envelope signals obtained from the second set of light receiving areas in order to generate a second added signal, and a tracking error generating circuit which takes the difference between the first added signal and the second added signal in order to generate a tracking error signal representing the tracking error.