JPS6329330A - Optical information recording and reproducing device - Google Patents

Abstract

PURPOSE:To facilitate the replacement of a semiconductor laser by freely attaching and detaching a semiconductor laser and a laser unit composed of an optical type to make a light beam emitted from the semiconductor laser into a parallel light to and from an optical type information recording reproducing device. CONSTITUTION:For an optical head 10, a laser unit 6 having a semiconductor laser 16 and a collimator lens 18 is fitted, and a beam light radiated from the semiconductor laser is made into a parallel light through the collimator lens 18. At the collimator lens 18, a cylinder-shaped fitting shaft 36, in which the surface is finished with a good accuracy, is provided, and a circular fitting hole 38, in which the inner circumference is finished with excellent accuracy, is provided at the optical head 10 side. When the difference between the shaft and the diameter of the hole is suppressed to about >=30mum, the head can be inserted into the prescribed size accuracy requested as a laser unit. In short, when the laser unit 6 is fitted to the optical head 10, the adjustment such as the swinging adjustment is not necessary, the laser unit 6 can be easily fixed to the optical head 10 with a machine screw, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [1] The first field of industrial application is recording, reproducing, or erasing information by irradiating the surface of a disk-shaped recording medium (hereinafter simply referred to as a disk) with a conductor laser. Regarding the optical information recording and reproducing device, here, what is the optical information recording and reproducing device?
This includes all devices that perform only recording, devices that only reproduce, and devices that perform both.

[Conventional techniques are now available] As a recording medium capable of recording, reproducing, and erasing information using a light beam, a 75 disk made of disk-shaped glass, plastic, etc., and a conventional disk set on this base. A so-called magneto-optical disk memory consisting of a qi direct magnetization film with a thickness of 100 to 500 nm is known. The river surface magnetization film is made of an amorphous alloy or the like, and has a characteristic of being magnetized in a direction perpendicular to the If1 plane.

To record information on such a magneto-optical disk memory, first, a perpendicular magnetic field is applied to the magneto-optical disk memory to align the magnetization direction of the east-face magnetized film in advance. A laser beam spot subjected to eW is irradiated onto the east face magnetized film to raise the temperature of the river face magnetized film in that area to a temperature higher than the Curie point. Then, the area illuminated by the laser beam spot is colored by the surrounding magnetic field! The magnetization direction is reversed and becomes logic “1”.
' (or "0") is recorded to form a recording bit.

In this way, in order to obtain a perpendicularly magnetized film with a Curie pattern, the laser power must be 8 to 1 oa at the disk hill.
Due to the efficiency of various optical components, the laser main body requires a laser power of about 30 mW.

Currently, many optical head units use small semiconductor lasers, and when such semiconductor lasers are used, there is a problem with their service life. In conventional information reproduction-only devices such as optical disk devices, the lifespan of semiconductor lasers is not a big problem because a large amount of laser power is required for initial recording, or a very large amount of laser power is not required for playback. Ta.

[Problems that IJ+ tries to solve] However,
In rewritable disk devices such as magneto-optical disks, large laser power is required for long periods of time for recording and erasing.
1) Due to the lifespan of the conductor laser, it becomes unnecessary to replace the laser unit. Since replacing the laser unit is a cumbersome task, it has traditionally been done by a professional service person, but in the future it will be desirable to be able to do it by the user himself.

"["] This Q+51 was developed in view of the problems of the prior art mentioned above, and its purpose is to provide an optical information recording and reproducing device that allows the user to easily replace the semiconductor laser. Our goal is to provide the following.

[Means for solving the problem] According to Kiuke 11, the above purpose is to reduce T° to the information recording medium.
Optical information recording +Ij' that records and/or reproduces information by irradiating a light beam from a conductive laser
l: In the apparatus: A laser unit consisting of the semiconductor laser and an optical system that directs the light beam emitted from the semiconductor laser is detachable from the optical information recording recoating. This is achieved by an optical information recording/reproducing device having the following characteristics.

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

：JS1 Figure 1 is a schematic side view (A) showing an embodiment of a disc triad device having an optical information recording/reproducing system according to the present invention.

As shown in the figure, the disk drive unit 712 of this embodiment has a rectangular main body cover 4. The lower part of the main body cover has an opening 8 for attaching and detaching a laser unit 6 provided with a conductor laser. Further, as shown in the figure, the main body cover 4 includes an optical head 10, an objective lens 12, and a disk 14 as an information recording medium. The objective lens 12 is moved to the disk 1 by an objective lens drive device (actuator) not shown.
4, it is movable in the focusing direction and the tracking direction. Further, the disk 14 is rotatably supported by a rotary drive means (not shown) (e.g. spintlemorph).

Further, as shown in the figure, a laser unit 6 having a semiconductor laser 16 and a collimator lens 18 is attached to the optical head IO.

The light beam emitted from the semiconductor laser is converted into a beam of light through a collimator lens 18. Furthermore, the beam destination is a beam shaping prism 2 provided in the optical head 10.
After passing through the polarizing beam splitter 22 and the polarizing beam splitter 22, the beam is irradiated onto the disk 14 in the form of a spot by the objective lens 12, which is supported by an nf sheet that moves in the orcus direction and the tracking direction by an actuator (not shown).

The beam light reflected by the disk 14 passes through the objective lens 12.
It is reflected in the right angle direction by the polarizing beam breaker 22, passes through the condensing lens 24, and is reflected by the half mirror 26.
incident on . The beam light incident on the half mirror is separated into two directions as shown in the figure, and one side is incident on the detector 30a via the analyzer 28a, and the other side is incident on the detector 30b via the analyzer 28b. Detector 28a.

The signals detected separately in 28b are detected as signals in the focusing direction on one side and in the tracking direction on the other side. Then, the detected signal is fed back to the actuator mentioned above, and based on the signal, autofocus and autotracking control of the objective lens is performed.
0a.

30b may be detected.

The following is an explanation of the Disc Trilife device.

Next, the laser unit 6 attached to the optical head IO will be described in more detail using FIG. 2. Incidentally, FIG. 2 is an exploded perspective view of the laser unit 6.

[4] As shown in FIG. 4, since the laser unit 6 is a semiconductor laser, the semiconductor laser substrate 32 is exposed to 4T. A flexible substrate 34, which is electrically connected to the semiconductor laser and has flexibility, is fixed to the substrate. Furthermore, the laser unit 6 includes a collimator lens 18 that converts the beam light emitted by the semiconductor laser into parallel light. As shown, the collimator lens 18 has a flange shape, and a screw hole is provided in the flange portion. A screw hole is also provided in the substrate 32, and the collimator lens S plate 32 and the collimator lens 18 are fixedly connected with screws or the like after optical adjustment. In addition, the l′-conductor laser board 32 and the collimator lens 1
8 cannot be connected or disconnected by the user. This is because very delicate work is required to convert the beam emitted by a semiconductor laser into parallel light.

Further, the laser unit 6 as described above is detachably attached to the optical head lO. Also, the collimator lens 18 has a cylindrical fitting shaft 36 whose surface is precisely finished, and the optical head 10 side has a circular fitting hole 38 whose inner periphery is finished with good viscosity. are doing. If the difference between the diameters of this shaft and the hole is kept to about 30 gm or less, it is possible to insert and mount the laser unit with the predetermined recess accuracy required for the laser unit. In other words, when attaching the laser unit 6 to the optical head 10, there is no need to make adjustments such as A/E'), and the laser unit 6 is inserted into the cylinder with screws etc.
It is necessary to fix the optical head 10 to the optical head 10 on the ITT.

Furthermore, as mentioned above, the disk drive equipment? Since the main body cover 4 of t2 is provided with an opening 8 for attaching and detaching the laser unit 6, the laser unit 6 can be easily replaced or dyed even from outside the 'At.

Furthermore, if the flexible board 34 connected to the semiconductor laser is used as a control board for only the semiconductor laser, it can be replaced at the same time by removing and inserting it when replacing the laser unit.

As explained above, in the first embodiment, even the user can easily replace the semiconductor laser.

Also, 7 (in case of +g1, the semiconductor laser is attached from below, or it can be attached from the side in the same way. However, in that case, the opening is also on the side)j
Is it necessary to install it in the opposite direction? Furthermore, even if the optical head is located toward the top of the disk and the laser unit is installed from one direction, if the opening is provided in the 11th direction, it can be replaced easily. By opening an opening corresponding to the +t direction, the laser unit can be easily replaced.

Furthermore, even if a high-frequency superimposition circuit is attached to the semiconductor laser, if it is fixed together with the semiconductor laser, the laser unit can be replaced without removing the high-frequency superposition circuit.

[Effects of Equation 11] As mentioned above, according to the present invention, even when the life of a semiconductor laser provided in an optical information recording/reproducing device reaches the end of its life, it is possible to replace the laser. The work can be easily done by the user himself.

[Brief explanation of the drawing]

1t''A is a schematic side view showing an embodiment of the optical information recording IIf raw coating disc tryz device according to the present invention;
FIG. 2 is an exploded perspective view of the laser unit constituting the end 14. FIG. 6...Laser unit 8...Aperture IO--Optical head l2...Objective lens 14...Disk 16...Semiconductor laser 18--Collimator lens Agent Patent attorney Minoru Yamashita Mo. Figure 1

Claims (1)

[Claims] (1) In an optical information recording and reproducing device that records and/or reproduces information by irradiating a light beam from a semiconductor laser onto an information recording medium, the semiconductor laser and the light beam emitted from the semiconductor laser are 1. An optical information recording and reproducing apparatus, characterized in that a laser unit comprising an optical system for collimating light is removably attached to the optical information recording and reproducing apparatus.