Fitzpatrick, Cella, Harper & Scinto
Optical head for recording, reproducing, or erasing information having fixed and movable head units
 An optical head for recording, reproducing, or erasing information by projecting a light beam onto a disk-like recording medium. The optical head includes a fixed head unit having a light source for generating the light beam and a sensor for receiving light reflected from the disk-like recording medium which was generated by the light source and projected onto the disk-like recording medium. The head also includes a movable head unit movable in the radial direction of the disk-like recording medium toward the fixed head unit. The movable head unit has an objective lens for condensing the light beam generated by the light source and projecting the light beam generated by the light source and projecting the light beam onto the disk-like recording medium. The fixed head unit and movable head unit each include a wall having an optical path window therein positioned in the optical path between the first head unit and the movable head unit. Each wall also includes a portion surrounding the optical path window and projecting in the direction of the optical path between the fixed head unit and the movable head unit. 
Canon Kabushiki Kaisha
G
G11B
inventional
Nobuaki Yasuo
Date Suzuki