JPH02210639A - Optical information recorder - Google Patents

Abstract

PURPOSE:To reduce an installing space and to obtain a system suitable for systematization with another information equipment by arranging a ferromagnetic material in the neighborhood of an objective lens on an optical head part, providing an electromagnet consisting of a bias coil as enclosing the material, and eliminating the interference of the ferromagnetic material at the time of moving the optical head part. CONSTITUTION:An optical member supporting part 7 incorporating an optical member such as a semiconductor laser, a convergence lens, a beam splitter photodetector, and a driving device (not shown in figure) to drive the objective lens 3 in tracking and focusing directions are provided, and the driving device is protected with a cover 4. The whole of the optical head part is supported slidably with a sliding shaft 10 via a bearing 9, and a core 35 is arranged in the periphery of a beam of light through hole on the cover 4 of the optical head part by protruding in the inside of the bias coil 32. The coil 32 is supported with a nonmagnetic member 29, and also, the interference of the core 35 is eliminated even when the tracking operation of an optical head is performed. Here, the core 35 is comprised of the ferromagnetic material or a member including the same.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to an optical information recording device that records information on a magneto-optical recording medium, which is an information recording medium, by cooperating a light beam and a magnetic field. .

Here, the magneto-optical recording medium can take various forms such as a disk-like shape and a card-like form, but a disk-like magneto-optical recording medium (hereinafter referred to as a magneto-optical disk) will be explained below as an example.

[Prior Art] A magneto-optical disk is formed by forming a magnetic thin film having an axis of easy magnetization perpendicular to the film surface on a substrate, and records information by changing the magnetization direction of this magnetic thin film. During recording, the magnetization direction of the magnetic thin film is first aligned in one direction, and a laser beam that is digitally modulated according to the information signal is irradiated while applying a bias magnetic field in the opposite direction to the magnetization direction. do. As a result, the temperature of the area irradiated by the laser beam increases and the coercive force decreases.
Under the influence of the bias magnetic field, it is magnetized in the opposite direction to the surroundings, forming a magnetization pattern according to information. Information recorded in this manner can be optically read out using the well-known magneto-optic effect by irradiating the medium with a low-power unmodulated beam. Furthermore, recorded information can also be erased by applying a magnetic field in the opposite direction to the bias magnetic field during recording.

FIG. 4 is a schematic cross-sectional view showing an example of the configuration of a conventional magneto-optical recording device. In the example shown in FIG. 4, the bias magnet 47 has a size that covers the recording area of the magneto-optical disk 43 in the radial direction, and is fixed to the upper cover 42 of the apparatus. With the upper lid closed, the bias magnet 47 approaches the magneto-optical disk 43 as shown by the broken line. Although this example has a simple configuration as described above, there is a problem in that the applicable devices are limited to those with an openable and closable top lid. The problem of installing and removing media is very important when considering systemization with other information devices.For example, as an alternative to magnetic disks, there are particular restrictions on the height of the installation space, and it is difficult to open and close the lid. The above-mentioned apparatus, which requires space, could not be used.

[Problems to be Solved by the Invention] However, the conventional example described above has the following problems.

In the conventional example shown in FIG. 4, the bias magnet is fixed to the upper lid of the device. For this reason, there is a problem in that applicable devices are limited to those with an upper lid that can be opened and closed. The problem of loading and unloading such media is very important when considering systemization with other information devices. It was not possible to use the above-mentioned device, which required an opening/closing space. Another possibility is to install a bias magnet in the device and provide a mechanism to move the bias magnet away from the insertion path when inserting the magneto-optical recording medium, but this mechanism is complicated, difficult to downsize, and heavy. There is a problem with this.

[Summary of the Invention] The present invention has been made in view of the problems of the prior art described above, and its purpose is to provide a magneto-optical recording device that requires a small installation space and is suitable for systemization with other information devices. There is a particular thing.

The above object can be achieved by the following optical information recording device.

In an optical information recording device having an optical head section moving mechanism for moving an optical head section having an optical system for irradiating light onto an information recording medium with respect to a base, the optical head section is located near the optical system. 1. An optical information recording device, characterized in that a magnetic body is disposed at the base, and a coil is disposed at the base so as to surround the magnetic body.

[Example] Hereinafter, an example of the present invention will be described specifically and in detail based on the drawings.

FIG. 1 is a perspective view showing an optical information recording device of the present invention. Recording of information used in optical information recording devices,
As shown in the figure, the optical head section for reproducing and erasing includes an optical member support section 7 containing optical members (not shown) such as a semiconductor laser, a condensing lens, a beam splitter, and a photodetector, and an objective. It has an objective lens drive device (not shown) that drives the lens 3 in the focus direction (direction C in the figure) and the tracking direction (direction A in the figure), and the objective lens drive device is protected by a cover 4. The entire optical head section is supported by a sliding glaze lO via a bearing 9 so as to be slidable in the D direction. FIG. 2 is a sectional view showing the optical information recording device.

As shown in FIG. 2, a core 35 is installed around the light beam passage hole on the cover 4 of the optical head section so as to protrude inside the bias coil 32. The bias coil 32 has a base (
The bias coil 32 is supported by a non-magnetic member 29 (a non-movable part relative to the optical head part, which is a movable part of the main body of the optical information recording device), and the bias coil 32 is designed to prevent the core 35 from interfering with the tracking operation of the optical head. It is wound long at least in the direction of movement of the optical head (inward direction in FIG. 1). The core 35 is made of a member containing a ferromagnetic material or a ferromagnetic material. By energizing the bias coil 32, a magnetic field in the direction of the optical axis of the objective lens is formed in the core 35, but a magnetic field is placed between the recording medium and the magnetic material on the recording medium 28 in order to increase the H component. A facing yoke 27 is left on the side facing the objective lens.

[Other Examples] Next, another embodiment according to the present invention will be described.

The present invention can be modified in various ways other than the embodiments described above, and the present invention includes such modifications as long as they do not depart from the scope of the claims.

FIG. 3 is a sectional view showing the optical information recording device.

Regarding the arrangement of the core 35, it may be provided on the movable side (optical system holder 2) of the optical system drive device as shown in FIG. In this case, since the objective lens is always auto-focused with respect to the recording medium 28, the distance between the magnetic flux leakage end of the core 35 and the magnetic surface is always kept constant. This eliminates the need for a bias magnetic field generator with more acoustic power. Furthermore, there are no restrictions on the cross-sectional shape, etc. of the opposing yoke 27.

[Effects of the Invention] As explained above, a ferromagnetic material or a member containing a 5-ferromagnetic material is arranged on the optical head part, especially around the objective lens, and is arranged so as to surround this and to accompany the movement of the optical head part. By adopting a method of generating a bias magnetic field using an electromagnet consisting of a bias coil wound with the ferromagnetic material without interference, there is no need to provide an electromagnet on the opposite side of the optical head section and the recording medium. , a thinner and more compact magneto-optical recording device is provided.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an optical information recording device of the present invention; 2 and 3 are cross-sectional views showing an optical information recording device, FIG. 4 is a diagram showing a conventional magneto-optical recording device. 3...Objective lens 32...bias coil 35...core

Claims (1)

[Claims] (1) In an optical information recording device having an optical head section moving mechanism for moving an optical head section having an optical system for irradiating light onto an information recording medium relative to a base, the above optical system is provided near the optical system. 1. An optical information recording device, characterized in that a magnetic body is disposed in an optical head section, and a coil is disposed in the base section so as to surround the magnetic body.