Asahi Kogaku Kogyo Kabushiki Kaisha

Tdk Corporation

Tsuyoshi Itoh

Masahiro Oono

Isao Okuda

Toshiyuki Kase

Koichi Maruyama

Hiroshi Yamamoto

Hiroshi Nishikawa

Masahiko Sasaki

Mamoru Usami

Makoto Iki

Junichi Ide

Futoshi Kobayashi

Takeshi Umega

Katsuki Hayashi

Haruhiko Yamaguchi

Yoshimi Yodogawa

Ryota Ogawa

Isao Takahashi

Ryoto Ogawa

Masahiro Ono

There is provided an optical recording medium-manufacturing apparatus that is capable of avoiding breakage of a substrate while avoiding formation of a central hole off-center with respect to the substrate. A control section causes the vertical movement section to move an ultrasonic horn in directions toward and away from the cutting edge of a punching blade section to thereby cause the ultrasonic horn to press the disk-shaped substrate and at the same cause an ultrasonic generator to perform ultrasonic vibration at least from a time point at which the disk-shaped substrate is brought into contact with the cutting edge of the punching blade section to a time point at which the punching of the central hole is completed.

Optical recording medium-manufacturing apparatus

There is provided an optical recording medium-manufacturing apparatus that is capable of accurately transferring a disk-shaped apparatus during a manufacturing process, and at the same time occupies a small installation area. A control section causes a cut-forming machine installed at a cut-forming location to form a cut in a resin layer of a disk-shaped substrate, then causes an indexing mechanism to rotate a transfer stage to thereby transfer the disk-shaped substrate formed with the cut to a central hole-forming location, and then causes a punching machine to punch a central hole.

An optical recording medium-manufacturing apparatus which is capable of reducing wear of a cut-forming blade section used for forming a cut in a resin layer, without increasing the component costs of the apparatus. An ultrasonic horn includes a hollow-cylindrical cut-forming blade section for being pushed into a resin layer formed on one side of a disk-shaped substrate, thereby forming a circular cut in the resin layer. A control section controls motion of the ultrasonic horn caused by a moving mechanism. The control section causes the ultrasonic horn to be pushed in to the resin layer while causing ultrasonic vibration thereof to thereby form the cut, and while maintaining a state of ultrasonic vibration of the abutment section and a pushed-in state of the cut-forming blade section, causes the punching blade section to be pushed into the disk-shaped substrate, to form the central hole.

An apparatus and method for inspecting a beam splitter which is to be used in splitting a laser beam. The apparatus includes laser beam sources (including laser diodes and collimator lenses) for projecting a plurality of images through the beam splitter being inspected and onto a single photo detector. Based on the relative positions of the images on the photo detector, an accuracy characteristic of the beam splitter to be inspected can be determined. Each of the light beams emitted from the beam sources are transmitted through a condenser lens and through a pinhole provided in a diaphragm plate having a ground glass plate on an incident side. The pinhole provides a point source which is converted into a parallel beam by a lens. The beams are then made incident on the beam splitter to be inspected, are transmitted and reflected, and are emitted onto the photo detector in a relationship related to the accuracy characteristic of the splitter. The beams form images on a monitor connected to the photo detector.

Beam splitter inspection apparatus and method

A method of adjusting a beam splitter of an optical information recording/reproducing apparatus is provided. The optical information recording/reproducing apparatus includes a laser light source, an objective optical system for converging the light beam from the laser light source, a guide rail mechanism for moving the objective optical system, a beam splitter mounted in an optical path of the light beam parallel to the transfer direction and photodetectors for detecting the light beam split by the beam splitter. The method of adjusting the beam splitter includes supporting a supplementary laser source for emitting a laser beam on the guide rail mechanism so that the laser beam of the supplementary laser source is incident onto the beam splitter along the optical path. The method further includes adjusting the beam splitter, while observing the split laser beam from the beam splitter at plural points where the photodetectors are to be mounted.

Method for a adjusting a beam splitter in an optical recording and

A device in which an offset is added to a focusing error signal to control an objective lens and thereby reduce the generation of cross-talk when a beam spot that is converged on an optical disk crosses over a wall of a groove of a track of the disk. By adding the offset to the focusing error signal, the objective lens is moved out of focus with the disk. Thus, the shape of a beam spot formed on a photo sensor is changed from a circle to an ellipse. A condenser lens provided for forming the beam spot is moved along the optical axis thereof in such a manner that an output of a recorded signal of the disk is at a maximum value. As a result, the objective lens is brought into focus on the disk. Thereafter, the objective lens is focused on the disk in accordance with the focusing error signal to which the offset is added, while maintaining the beam spot in the shape of an ellipse.

Device for and method of reducing cross talk in optical disk device

An apparatus for measuring a wave front aberration includes a light beam splitter for dividing a parallel laser light beam made incident from a measuring object into two beamfluxes, an image rotator disposed in at least one optical path of the divided beam fluxes for rotating the wave front on the optical axis, an interference device for interfering after superposing the beam fluxes whose wave fronts are rotated relatively, an imaging lens for forming the interfered beam into an image, and an observation device for observing the imaged interference fringes.

Wave front aberration measuring apparatus having means for adjusting

In the magneto-optic recording/reproduction apparatus, a light beam from a semiconductor laser that can be used with two wavelengths, for recording and reproduction is converged by an objective lens on a magneto-optic disk, a predetermined offset is added to this focusing error signal by an offset adjusting circuit, and the objective lens is driven in the direction of the optical axis based on the focusing error signal to which an offset was added.

Magneto-optic recording/reproduction apparatus for minimizing variation

An optical system of an optical disk apparatus having plural optical elements characterized in that the optical element having aberration which can counterbalance the wave front aberration of the whole optical system is disposed, or a direction of aberration of each existing optical element is adjusted in order to correct the wave front aberration.

Optical disk apparatus having a focusing error correcting system

A mechanism for adjusting an optical axis of an optical device, particularly in an optical information recording and reproducing system, in accordance with which the optical axis is movable in two directions, independently of each other. Various parts of the optical system, such as an anamorphic prism and a fixed prism, may be moved to adjust the degree of parallelism and/or displacement of a laser beam. A laser ray source in the system also may be movable independently in different directions.

Optical axis adjusting mechanism and method for optical information

An apparatus for measuring a wave front aberration including a light beam splitter for dividing a parallel laser light beam incident from a measuring object into two beam fluxes, an image rotator disposed in at least one optical path of the divided beam fluxes for rotating the wave from on the optical axis, an interference device for interfering, after superposing the beam fluxes, whose wave fronts are rotated relatively, an imaging lens for forming the interfered beam into an image, and an observation device for observing the imaged interference fringes.

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Tokyo, Japan

Tsuyoshi Itoh