Patent ID: 6850472

Claim:
An optical pickup device, comprising: a light source for emitting a light; a condenser lens for focusing a reflected light from a recording medium of the light emitted from said light source; dividing means for dividing a light passed through said condenser lens into a light passed through a high numerical aperture region of said condenser lens and a light passed through a low numerical aperture region of said condenser lens; light receiving means including at least a first light receiving element for detecting the light passed through said high numerical aperture region and a second light receiving element for detecting the light passed through said low numerical aperture region; and focus control means which prepares a first focus error signal based on an output signal at least from said first light receiving element and a second focus error signal based on an output signal from said second light receiving element, and which performs a focus control based on either the first focus error signal or the second focus error signal according to an output value from said light receiving means.