JPH05234172A - Optical head - Google Patents

Abstract

PURPOSE:To eliminate a magnetic head device, to accelerate access by lightening and to miniaturize a device by providing a coil for generating magnetic field around the beam outgoing from a converging grating coupler. CONSTITUTION:Radiant beams outgoing from a laser diode 2 is converted to the beam of nearly 1mu by the action of the converging grating coupler 3 and emitted from a waveguide head. A return beam from a disk passes through an opposite light path and enters a grating splitter 4 through the converging grating coupler 3 again and is incident on a photodetector 5 separated to the beam for servo and the beam for regenerating signal. By such a constitution, heating and the application of magnetic field from one side direction is possible and the constitution of the device is simplified and an optical head is lightened and accelerated access is achieved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical head mechanism used in an optical disk recording / reproducing apparatus for recording information on a rotating flat disk or reproducing already recorded information.

[0002]

2. Description of the Related Art As a device for optically recording information on a concentric or spiral track formed on a rotating disk, or for optically reading and reproducing already recorded information, There are devices such as compact discs and optical video discs that record in the shape of irregularities, irradiate a light beam on this, and reproduce by utilizing the interference of light, or magneto-optical discs that record and reproduce by utilizing the magneto-optical effect. It has already been put to practical use.

As shown in FIG. 2, a conventional magneto-optical disk device has an optical head 14 and a magnetic head 1 with a disk 17 interposed therebetween.
5 are opposed to each other, and the optical power of the optical head 14 is fixed at a high output, and the magnetic field of the magnetic head 15 is modulated in a pulse shape to perform overwriting.

Since the magnetic head 15 is required to have a magnetic force (200 Oe to 400 Oe) necessary to change the magnetization direction of the recording medium and a high frequency modulation speed is required, a structure close to the disk 17 is required. .

However, since surface wobbling of the disk 17 and mechanical precision of the spindle motor 16 occur, the disk 17 and the magnetic head 15 cannot be so close to each other, and a drive mechanism having a focusing mechanism is required for the magnetic head.
There was a problem of large size of the device and high cost.

Further, as shown in FIG. 3, the optical head 14 and the magnetic head 15 are made of the same member so that a desired magnetic flux is generated even if the magnetic head 15 becomes large, but it is driven along the carriage rail 24. However, the weight of the movable part during tracking access was extremely increased, and it was not suitable for high-speed access.

[0007]

In order to solve the above problems, the present invention provides an optical head device in which a waveguide type optical head is provided with a coil and a yoke around a light beam emitting portion.

[0008]

With the above construction, the magnetic head device can be eliminated, and the device is lightweight, so that high-speed access and downsizing of the device can be achieved.

[0009]

Embodiment An embodiment of the present invention will be described in detail with reference to FIG.

FIG. 1 is a perspective view of the entire magnetic field modulation waveguide type optical head of the present invention.

The optical head includes a substrate 1, a laser diode 2, a condenser grating coupler 3, a grating beam splitter 4, a photodetector 5 and the like in a waveguide.

A coil 6 for generating a magnetic field and a yoke 7 are provided on the surface of the condenser grating coupler 3.

The emitted light from the laser diode 2 is converted into a beam of about 1 μ by the action of the condensing grating coupler 3 and emitted from the waveguide head. The return light from the disk passes through the opposite optical path, goes back through the condensing grating coupler 3 and enters the grating beam splitter 4, is separated into servo and signal reproducing light, and is incident on the photodetector 5.

[0014]

With the above structure, it is possible to heat and apply a magnetic field to the recording medium 8 from one direction, simplifying the structure of the device and reducing the weight of the optical head, and achieving high-speed access. .

[Brief description of drawings]

FIG. 1 is an overall perspective view of a magnetic field modulation type optical head of the present invention.

FIG. 2 is a structural example of a conventional magnetic field modulation type optical head.

FIG. 3 is a magnetic head configuration example of a conventional magnetic field modulation type optical head.

[Explanation of symbols]

 1 substrate 2 laser diode 3 condensing grating coupler 4 grating beam splitter 5 photodetector 6 magnetic field generating coil 7 yoke 8 recording medium 11 reflection mirror 12 irradiation beam, collimated light 13 focusing grating coupler 14 optical head 15 magnetic head 16 spindle motor 17 Disk 18 Magnetic Head Carriage 19 Magnetic Head Carriage Rail 20 Magnetic Head Moving Direction 23 Carriage Roller 21 Lens Actuator 24 Carriage Rail 22 Optical Head Moving Direction 25 Magnetic Head Holding Arm

Claims (1)

[Claims] 1. An integrated optical head having a laser light source, a condensing grating coupler, a grating beam splitter, etc. on a waveguide, wherein a coil for generating a magnetic field is provided around light emitted from the condensing grating coupler. Integrated optical head characterized by