Patent ID: 7595472

Claim:
An optical head device which reproduces information recorded in an optical disk including recording layers, comprising: a light source which emits a light beam, the light source being capable of selectively emitting a high-output light beam and a low-output light beam; an objective lens which condenses the light beam on the optical disk; a condensing lens which condenses reflected light from the optical disk; a shielding element disposed near a focal point of the condensing lens and having a pinhole, the shielding element including a transparent substrate and a thin film disposed on the transparent substrate, the thin film being partially melted by application of the high-output light beam to form the pinhole which passes the reflected light from a reproduction layer of the optical disk and partially interrupts the reflected light from a non-reproduction layer of the optical disk; and a photodetector which detects light passed through the pinhole of the shielding element.