Abstract: An optical device inclination angle adjuster for adjusting an optical axis of an optical device. The optical device has an optical axis and a peripheral portion, and is held by a holder. The adjuster includes an annular plate inserted between the optical device and the holder. The annular plate is in alignment with the peripheral portion of the optical device, and has an opening with an axis in alignment with the optical axis of the optical device to permit passage of light through the opening of the annular plate and through the optical device. A first pair of projections are formed between the annular plate and the optical device. The first pair of projections are disposed diametrically opposite to each other with respect to the optical axis and project in a direction parallel to the optical axis. A second pair of projections are formed between the annular plate and the holder.

Abstract: The second harmonic wave of a solid laser light which is emitted from a second harmonic wave light source is divided into a plurality of laser beams by a diffraction grating. The divided laser beams are converged on a record carrier into a plurality of light spots by an optical head. Magnetic field generating coils for applying magnetic fields to the respective light spots in accordance with the recording signals from a signal line are disposed under the record carrier. Part of the solid laser light is reflected and input to a beam splitter. Since part of the light input to the beam splitter is taken out, a stabilizer controls the output of the solid laser light from the second harmonic wave light source, parallel recording/reproduction using the plurality of light spots which are arranged on the record carrier is enabled and the formation of the plurality of light spots is effectively controlled.

Abstract: A lens actuating system for an optical disk drive has an objective lens movably mounted in a movable frame with orthogonal X-, Y-, and Z-axes. A seeking servo moves the frame in the X-direction. A tracking servo moves the objective lens in the X-direction. A focusing servo moves the objective lens in the Z-direction. An optoelectronic sensor detects the relative position of the objective lens and frame in the X-direction, so that the tracking servo can maintain a fixed relative position during track-seeking, or in the Z-direction, to establish a neutral point on the Z-axis for the focusing servo. Force applied by the focusing servo or tracking servo to move the objective lens in one direction can be opposed by an equal and opposite force applied to a driven mass, so that a net zero force is transmitted to the frame.

Abstract: A lens actuating system for an optical disk drive has an objective lens movably mounted in a movable frame with orthogonal X-, Y-, and Z-axes. A seeking servo moves the frame in the X-direction. A tracking servo moves the objective lens in the X-direction. A focusing servo moves the objective lens in the Z-direction. An optoelectronic sensor detects the relative position of the objective lens and frame in the X-direction, so that the tracking servo can maintain a fixed relative position during track-seeking, or in the Z-direction, to establish a neutral point on the Z-axis for the focusing servo. Force applied by the focusing servo or tracking servo to move the objective lens in one direction can be opposed by an equal and opposite force applied to a driven mass, so that a net zero force is transmitted to the frame.

Abstract: An optical head for recording, reproducing or erasing data by emitting a light beam irradiated from a light source onto a recording medium. To reduce the height of the optical head, an optical axis shifting device is disposed between a light beam emitting device and a condensing device for condensing the light beam onto the recording medium. This optical axis shifting device shifts the first optical axis of the light beam from the light beam emitting device to a second optical axis positioned in parallel and spaced apart from each other. As the optical axis shifting device, there is preferable employed a prism having two reflecting faces lying in parallel, and the optical axis, after shifting is to be positioned downwardly of the position of the optical axis before shifting, thereby reducing the height of the optical head.

Abstract: An optical head apparatus wherein a lens holder which holds an objective lens for condensing a light beam on an optical recording medium is turned in a plane perpendicular to an optical axis of the objective lens and one portion of construction members of turning unit for performing a tracking control for the optical recording medium is fixed to a fixed body. One or some of construction members of the turning unit for tracking control is not mounted to a moving body for supporting the lens holder but is mounted to the fixed body, as a result, weight of a movable unit including the moving body and its loading members is to be reduced to realize high-speed access with respect to the optical recording medium.

Abstract: An optical read-write apparatus for reading and writing information in tracks on an optical medium such as an optical disk has two or more beam sources for producing light beams with different wavelengths, and corresponding dichroic mirrors mounted in the path of the beams. Each of the dichroic mirrors reflects light of the wavelength of one of the beams and transmits light of other wavelengths. Piezoelectric transducers are provided for tilting one or more of the dichroic mirrors to adjust the tracking of the beams. An objective lens receives the beams after reflection from the dichroic mirrors and focuses them onto the optical medium.