Patent ID: 7764575

Claim:
A tracking error detecting method comprising the steps of: causing an intensity distribution of a single light introduced into an objective lens to have symmetry with respect to an oblique direction, which is oblique to a track direction of an optical recording medium, and a direction perpendicular to said track direction, before said single light having said intensity distribution is irradiated on said optical recording medium; irradiating said single light having said intensity distribution on said optical recording medium; detecting a reflection light, which is a reflection of the single light from the optical recording medium, by a light-receiving unit having first and second groups of light receiving sections, which are arranged in said track direction, and having third and fourth groups of light receiving sections, which are arranged in said direction perpendicular to said track direction; and detecting a tracking error signal based on difference between a sum of signals from said first group of light receiving sections and a sum of signals from said second group of light receiving sections, and difference between a sum of signals from said third group of light receiving sections and a sum of signals from said fourth group of light receiving sections.