JPH01143003A - Device for impressing external magnetic field for magneto-optical disk device - Google Patents

Abstract

PURPOSE:To drive an electromagnet by a single turning type driving power source and to reduce the size, weight and cost of the title device by linearly moving a moving base which is screwed to a screw shaft parallel with a magneto-optical disk surface and moving a rotating and rectilinearly advancing unit downward by rotating the screw shaft. CONSTITUTION:The moving base 2 screwed with the screw shaft 1 advances rectilinearly in one way along the shaft 1 when a motor is started in accordance with a 1st command and the shaft 1 is rotated forward. A pinion 6a engaged with a stationary rack 7 is rotated by the rectilinear advance of the moving base 2 and a spur gear 5b of the rotating and rectilinearly advancing unit 5 is rotated via a spur gear 6b coaxial therewith. A mounting frame 3 and the electromagnet 4 are thereby turned as well within the horizontal plane. A lever 8 is rotated counterclockwise by engagement of a pin 8c and cam groove upon further rectilinear advance of the mowing base 3. The unit 5 is then pushed downward by engagement of a connecting part 8b and a part 5c to be connected. The electromagnet 4 is thereby moved to the prescribed point opposite to the disk 19 surface in proximity thereto.

Description

[Detailed description of the invention] [Industrial application field]

The present invention is a device for moving an electromagnet serving as an external magnetic field applying means from an initial position near the outer periphery of a magneto-optical disk to a predetermined location close to and facing the surface of the disk based on a command, and returning the electromagnet to a predetermined location that closely opposes the surface of the disk. An external magnetic field application device in a magneto-optical disk drive driven by a magnetic power source.

[Conventional technology]

A conventional example will be explained with reference to the following drawings. FIG. 6 is a perspective view of the main part of the conventional example. In this figure, the electromagnet 35 is rotated by a motor 32 and is rotated by another motor 3.
It is configured to be lowered and raised by 6. An arm 34 extending laterally is fixed to the tip of a shaft 33 that is directly connected to the output shaft of the motor 32. An electromagnet 35 is fixed to the side surface of this arm 34. Further, the motor 32 is fixed on the moving table 31. The movable table 31 is guided so as to be movable upward and downward by a guide mechanism (not shown), and is connected via a motor 36 and a belt 37 so as to be capable of being driven downward and upward. Therefore, electromagnet 3
5 is rotated around its axis by a motor 32 based on a command, and is lowered and raised by a motor 36. The operation of this external magnetic field applying device will be explained with reference to FIGS. 7 to 9. Fig. 7 shows its operation; Fig. 7 (a) is a plan view when the cartridge is installed and before the electromagnet moves; Fig. 7 (b) is a side view thereof; Fig. 8 is similar; ) is a plan view at an intermediate stage of electromagnet movement, FIG. FIG. First, Kartli. When attaching the azalea 20, as shown in FIG. 7(b), first move it to the right as shown by the arrow from the position indicated by the dashed-dot line, then move downwards as indicated by the arrow from the position indicated by the two-dot chain line, A magneto-optical disk (hereinafter simply referred to as a disk) 19 is mounted at the solid line display position with its lower surface facing the optical head 18 in close proximity. At this time, as shown in FIG. 7(b), the moving device including the electromagnet 35 is located near the outer periphery of the cartridge 20 and does not interfere with the mounting of the cartridge 20, that is, it is in the retracted position. Next, based on the command, the motor 32 first operates as shown in FIG. 8(a).
As shown in the figure, the electromagnet 35 rotates 90 degrees counterclockwise, and the electromagnet 35, which was initially at the position indicated by the two-dot chain line, pivots to the position indicated by the solid line. At this time, the electromagnet 35 is connected to the cartridge 20.
It is located opposite to and above the hollow portion 20a (see FIG. 8(b)). Subsequently, the motor 36 rotates counterclockwise in FIG. Bring it close to a predetermined position facing the surface. At this time, the motor 32 remains stopped.

[Problems to be solved by the invention]

As described above, in the prior art, two motors 32 and 36 are used to move the electromagnet 35, and it is necessary to increase the rigidity of the arm 34 as a rotating member that holds the electromagnet 35. Therefore, ■2 motors and arm rigidity measures increase space, weight, and cost, making the device compact and
■The need to take measures to strengthen the arm, which is an obstacle to reducing weight and cost, means that the electromagnet is susceptible to external vibrations and shocks, which impedes proper recording and erasing.02 Using multiple motors causes problems such as □ which makes timing control troublesome. The purpose of this invention is to solve the problems of the conventional technology, to have a simple structure, small size, and light weight. It is an object of the present invention to provide an external magnetic field application device for a magneto-optical disk device, which can be manufactured at low cost and is driven by a single rotary power source.

[Means to solve the problem]

In order to achieve this object, an external magnetic field applying device in a magneto-optical disk device according to the present invention is provided, in which an electromagnet serving as an external magnetic field applying means is moved from an initial position near the outer periphery of the magneto-optical disk to its surface based on a command. In a device that is moved to a predetermined location close to each other and then moved back, (a) a screw shaft parallel to the surface of the magneto-optical disk is rotated in the normal direction based on a first command and reversed based on a second command; and (b) a pinion that is threadedly engaged with the screw shaft, is guided so as to be linearly movable, and is rotatable around an axis perpendicular to a plane containing the magneto-optical disk surface, and includes the magneto-optical disk surface. (c) a moving platform provided with a gear that is capable of moving straight in a direction of another axis perpendicular to the plane and rotatable around the other axis in conjunction with the rotation of the binion; a fixed rack parallel to the axis of the screw shaft; (d) a mounting frame fixed to the gear and provided with the electromagnet; and (e) a displacement device capable of displacing the gear in its axial direction in response to the straight movement of the movable platform. A mechanism, for example, a mechanism comprising a lever rotatably mounted on the translation platform, one end of which engages with the fixed cam and the other end of which engages with the shaft of the second gear; and a mechanism □ having a cam that engages with the shaft, first rotationally moves the electromagnet from the initial position to an intermediate location based on the first command, and then rotates the electromagnet from the intermediate location to the predetermined location. The electromagnet is displaced in a direction perpendicular to a plane including the disk surface, and the electromagnet is moved from the predetermined location through the intermediate location and back to the initial position based on the second command.

[For use]

Based on the first command, the screw shaft rotates in the normal direction, and the movable table screwed therewith moves straight. As the moving table moves straight, a pinion provided on the moving table and meshing with the fixed rack is rotated.
The rotation of this pinion causes the gears that mesh with it to
As a result, the mounting frame and electromagnet fixed thereto are rotated. Therefore, the electromagnet is moved from its initial position to an intermediate position by the combination of the linear movement of the moving table and the rotation of the gear as described above. When the moving table moves further straight, the gear is displaced in its axial direction via the displacement mechanism, and the electromagnet is moved from the intermediate position to a predetermined position,
In other words, it is moved to a position where it closely faces the surface of the magneto-optical disk. When the screw shaft is reversed based on the second command, the electromagnet is returned from the predetermined position to the initial position via the opposite path.

【Example】

DESCRIPTION OF THE PREFERRED EMBODIMENTS An external magnetic field application device for a magneto-optical disk device, which is an embodiment of the present invention, will be described below with reference to the drawings. Fig. 1 is a plan view of this first external magnetic field applying device, Fig. 2 is the same (its front view), and Fig. 3 is the same (its side view). , this first device basically consists of a screw shaft 1 as a driving member, a moving table 2 which moves straight by this movement, and a mounting frame 3 which rotates and moves straight by this movement and is provided with an electromagnet 4.The mounting frame 3 is formed as a plate-like member with a large surface area and has a heat dissipation function.In addition, supporting/guiding means for each of these members and a transmission means including a power source are auxiliary provided. .A guide frame 9 for the movable base 2, and a rotation/linear unit 5 provided to the movable base 2 so as to be rotatable and linear for the mounting frame 3.The movable base 2 has rollers 2a on its lower surface and supports on its upper surface. Shaft 2b and bearing 2c
(See Figure 2). The guide frame 9 is a plate-like member formed in a frame shape, and includes a bearing 9a (see FIG. 1) that supports one end of the screw shaft 1, and a U-shaped guide rail 9b that guides the moving platform 2 in a straight line. (see Figure 2), and cam groove 9c (
(see Figure 3). The movable table 2 is movable along a guide rail 9b via rollers 2a (see FIG. 2). In FIG. 2, the transmission means include a rotation/linear unit 5,
These are a gear unit 6, a fixed rack 7, a lever 8 and a motor 10 as a power source. The rotation/linear unit 5 includes a movable shaft 5a, a spur gear 5b provided at one end of the movable shaft 5a, and a groove-shaped connected portion 5c provided at the other end. rotation about its axis via the and bearing 2c,
It is set up so that it can go straight. Note that the spring 11 urges the rotation/linear unit 5 upward in its axial direction. The gear unit 6 includes a coaxial pinion 6a and a spur gear 6b, and is provided to be rotatable about the axis of the movable base 2 via a support shaft 2b. In FIG. 2, the rack 7 is fixed parallel to the screw shaft 1, meshes with the pinion 6a, and the spur gear 6b is connected to the spur gear 5.
meshes with b. The lever 8 is rotatably provided on the movable table 2 via a support shaft 8a, and has a bifurcated connecting portion 8b that engages with the connected portion 5c at one end and a cam groove 9c at the other end.
A pin 8c is provided to engage with the respective pins 8c. The motor 10 is
Its output shaft is coaxially and directly connected to one end of the screw shaft 1. The operation of this external magnetic field application device is as follows. 1st
In the figure, based on the first command, the motor 10 starts, the screw shaft 1 rotates in the forward direction, and the movable table 2 screwed therewith moves to -
Go straight to the bottom of the diagram from the position indicated by the dotted chain line. As the moving table 2 moves straight, a pinion 6a provided thereon and meshing with the fixed rack 7 is rotated, and a spur gear 6 coaxial with the pinion 6a is rotated.
b, the spur gear 5b of the rotary/linear unit 5 is rotated clockwise, and at the same time the mounting frame 3 and electromagnet 4 fixed to the spur gear 5b are also rotated clockwise. Therefore, the electromagnet 4 moves from its initial position indicated by the dashed line to
The cartridge 20 is moved to an intermediate location substantially opposite the hollow portion 20a of the cartridge 20, which is indicated by a two-dot chain line. Next, when the moving table 2 further moves straight downward in FIG. 1, the lever 8 is moved between the pin 8c and the cam groove 9c in FIG.
It rotates counterclockwise through engagement with the connecting portion 8b and the connected portion 5c, and pushes down the rotation/linear unit 5 in its axial direction. That is, electromagnet 4
moves from an intermediate position indicated by a two-dot chain line to a position closely facing the surface of the disk 19 as a predetermined position indicated by a solid line. When the screw shaft 1 is reversed via the output shaft of the motor 10 based on the second command, the electromagnetic stone 4 travels from the predetermined location indicated by the solid line to the predetermined location indicated by the - dotted chain line through the opposite path to the above. Move back to the initial position. As described above, since the electromagnet 4 takes a combination of linear movement and rotation, it requires a smaller movement space than simple rotational movement, which contributes to miniaturization of the device. The second external magnetic field applying device will be explained with reference to FIGS. 4 and 5. FIG. 4 is a front view thereof, and FIG. 5 is a side view thereof. This second device differs from the first device described above in the method of the displacement mechanism, in that the rotation/linear unit is directly displaced by a cam using the linear movement of the screw shaft. That is, the member corresponding to the lever 8 in the first device is unnecessary in this second device. Further, the rotation/linear unit 15 has a movable shaft 15a that is the same as the movable shaft 5a and the spur gear 5b in the first device. It consists of a spur gear 15b and a roller-shaped driven end 15c corresponding to the connected portion 5c. Note that the spring 12 rotates and
The linear unit 15 is urged downward in its axial direction. The guide frame 16 is a bearing 9a in the first device. It consists of a bearing 16a that is the same as the guide rail 9b, a guide rail 16b1, and a plate cam 16c corresponding to the cam groove 9c. The plate cam 16c and the driven end 15c engage with each other (the fifth
(see figure), the rotation/straight movement unit 15 is displaced in its axial direction in accordance with the movement of the moving table 2 in a straight line.

【Effect of the invention】

As explained above, in this invention, the screw shaft rotates in the normal direction based on the first command, and the movable base screwed therewith moves straight, and as the movable base moves straight, the screw shaft provided on the screw shaft is fixed. The pinion that meshes with the rack is rotated, and the rotation of this pinion rotates the gear that meshes with it, and in turn, the mounting frame and electromagnet that are fixed to it.
This combined movement of the moving carriage in a straight line and the rotation of the gear moves the electromagnet from its initial position to an intermediate position; as the moving carriage moves further straight, the gear is displaced in its axial direction via the displacement mechanism. , the electromagnet is moved from the intermediate location to a predetermined location, that is, to a location that closely opposes the surface of the magneto-optical disk; when the screw shaft is reversed based on the second command, the electromagnet travels through the opposite path to the predetermined location. It is moved back from the point to the initial position. Therefore, the present invention has the following superior effects compared to the conventional technology. (1) Since the electromagnet can be placed close to the surface of the magneto-optical disk, it can be made smaller and consume less power. (2) As with the previous item, since the space in which the electromagnet moves is small, the external magnetic field application device and, by extension, the magneto-optical disk device that houses it can be downsized. (3) Based on screw mechanisms, gear mechanisms, and cam mechanisms, the electromagnet moves in a combination of linear motion and rotation, so the space required for a given movement of the electromagnet is small, and the device can be made more compact. I can figure it out. (4) Since there is only one power source and the electromagnet is moved by a predetermined amount by forward and reverse rotation of the power source, reliability can be improved and costs can be reduced.

[Brief explanation of the drawing]

Fig. 1 is a plan view of one embodiment of the present invention, Fig. 2 is a front view thereof, Fig. 3 is a side view thereof, Fig. 4 is a front view of another embodiment, and Fig. 5 is the same. FIG. 6 is a perspective view of the main parts of the conventional example, and FIG. 7 similarly shows its operation. FIG.
b) is a side view of the same, Fig. 8 shows the same operation, Fig. 8(a) is a plan view at an intermediate stage of electromagnet movement, Fig. 2) is a side view of the same, Fig. 9 is the same (the The operation is shown, and the figure (a) is a plan view when the electromagnet movement is completed, and the figure (b) is the same side view. Symbol explanation 1: screw shaft, 2: moving table, 3: mounting frame, 4: Electromagnet, 5
, 15: Rotation/linear unit, 6: Gear unit, 7:
Rack, 8 levers, 9.16: Guide frame, 10: Motor, 19: Disk, 20: Cartridge, 20a: Hollow part. 1st bacterium 2nd figure 4th old 6th 7th fertilizer (?i) Hikari 8th record

Claims (1)

[Scope of Claims] 1) An apparatus in which an electromagnet serving as an external magnetic field applying means is moved based on a command from an initial position near the outer periphery of the magneto-optical disk to a predetermined position close to and opposite to the surface of the disk, and then moved back, (a) A screw shaft that is rotated forward based on the first command and reversed based on the second command, and is parallel to the surface of the magneto-optical disk; (b) Screwed with this screw shaft and guided so as to be able to move in a straight line. a pinion rotatable around an axis perpendicular to a plane containing the magneto-optical disk surface; and a pinion capable of moving straight in the direction of another axis perpendicular to the plane containing the magneto-optical disk surface; (c) a fixed rack that meshes with the pinion and is parallel to the axis of the screw shaft; (d) a gear that is rotatable around the other axis in conjunction with the rotation of the pinion; (e) a displacement mechanism capable of displacing the gear in its axial direction in accordance with the straight movement of the movable base; The electromagnet is rotated from the predetermined location to the intermediate location, and then displaced from the intermediate location to the predetermined location in a direction perpendicular to the plane containing the magneto-optical disk surface, and based on the second command, the electromagnet is moved from the predetermined location to the intermediate location. 1. An external magnetic field applying device for a magneto-optical disk device, characterized in that the external magnetic field applying device is configured to return to the initial position after returning to the initial position. 2) In the device according to claim 1, the displacement mechanism has one end engaged with the fixed cam and the other end engaged with the shaft of the gear, and is rotatably provided on the movable table. 1. An external magnetic field applying device in a magneto-optical disk device, characterized in that the external magnetic field applying device is provided with a lever that can be applied to a magneto-optical disk device. 3) An external magnetic field applying device in a magneto-optical disk drive, wherein the displacement mechanism includes another fixed cam that engages with the shaft of the gear.