JPH0229582Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a recording/reproducing device for a magnetic disk used as a recording terminal device in an electronic computer, a word processor, etc.

[Prior art and problems]

Conventionally, a so-called steel belt system has been frequently used for the intermittent feed mechanism that transports a carriage equipped with a magnetic head in the radial direction of the magnetic disk, but the steel belt system is troublesome to attach and adjust the tension of the belt, and takes up a lot of space. As an alternative to this, a screw shaft type carriage transfer mechanism has recently begun to be used in disk recording and reproducing devices because it is suitable for downsizing the device.

FIG. 1 is a plan view showing such a conventional screw shaft type carriage feeding mechanism. In the figure, 1 is a stepping motor attached to a chassis 2, 3 is a screw shaft having a spiral groove 3a on its outer periphery;
A cylindrical permanent magnet (not shown) serving as the rotor of the stepping motor 1 is fixed through the cylindrical permanent magnet, one end of which is supported by a bearing (not shown) of the casing of the stepping motor 1, and the other end supported by a bearing 4. has been done. Reference numeral 5 denotes a carriage equipped with a magnetic head 6 for writing and reading, which is transported along two guide shafts 7 and 8.
Reference numeral 9 denotes an engaging element attached to the carriage 5, and its conical tip 9a is engaged with the spiral groove 3a of the screw shaft 3.

In the above configuration, when the screw shaft 3 is rotated in the forward and reverse directions by the stepping motor 1, the pointed end 9a fitted into the spiral groove 3a moves in the direction of the arrow shown in the figure, and as a result, the carriage 5 moves toward the guide shaft 7. , 8 by an amount corresponding to the amount of rotation of the screw shaft 3.

By the way, the spiral groove 3a of the screw shaft 3 in the above configuration has the same advance angle θ over the entire circumference, as shown in FIG. 2, and is formed in a straight line when expanded. For this reason, for example, the rotation angle of the screw shaft 3 is 0°, 45°, 90°,
When the movement of the carriage 5 is intermittently stopped at 8 points of 135°, 180°, 225°, 270°, and 315°, the influence of the inertia of the carriage 5, the damped vibration of the stepping motor 1, and the rotation control Due to variations, etc., the carriage 5 may be slightly misaligned, which tends to impede the accurate writing and reading of the magnetic tracks on the disk by the magnetic head 6.

[Purpose of invention]

The present invention has been developed in view of the above points, and its purpose is to provide a disk recording and reproducing apparatus that is capable of accurately feeding and positioning a carriage to stop.

[Structure of the idea]

In order to achieve the above object, the present invention has an engaging element of a carriage equipped with a magnetic head for writing and reading engaged with a screw shaft, and the screw shaft is rotated by the driving force of a stepping motor. In a configuration in which the carriage is linearly fed at a predetermined pitch, the permanent magnet serving as the rotor of the stepping motor and the screw shaft are configured to rotate together, and the screw shaft has an advance angle of approximately 0° on the outer periphery of the shaft. and forming a plurality of grooves having substantially linear groove bottoms at equal intervals along the circumferential direction, and forming one spiral groove by sequentially displacing these grooves in the axial direction, On the other hand, the permanent magnet is characterized in that magnetization points are set at equal intervals corresponding to the circumferential intervals of the grooves.

[Example of idea]

The details of the present invention will be explained below with reference to the embodiments shown in FIGS. 3 to 8.

FIG. 3 is a partially cutaway plan view showing the carriage transfer mechanism, in which members that are the same or equivalent to those in FIG. 1 are given the same symbols. The stepping motor 1 has a casing 10 fixed to a chassis 2 of the main body of the device by screws 11, and inside the casing 10 there are a coil 13 wound around a coil bobbin 12 and a comb-like yoke 14 integrated with the casing 10. , is provided as the stator side of the motor, and a ring-shaped permanent magnet 15 is provided as the rotor. The permanent magnet 15 is fixed to the screw shaft 16,
The small diameter conical ends at both ends of the screw shaft 16 are
Bearings 17 each with a built-in ball pairing,
It is rotatably supported by 18. The bearing 17 is held in place by the chassis 2 through a holder 19, and the holder 19 is always pressed toward the screw shaft 16 by a built-in spring 20, and as a result, the screw shaft 16
is constantly pressed toward the bearing 18 side. Further, the bearing 18 is attached to an adjustment screw 22 that is screwed onto a support 21 attached to the stepping motor 1. Therefore, by turning the adjustment screw 22, the screw shaft 16 can be adjusted. The position can be adjusted by a small amount in the thrust direction.

FIG. 4 is an enlarged view of the main part showing details of the screw shaft 16 with which the engaging element 9 made of a plate spring engages. The screw shaft 16 has a predetermined range on its outer periphery that is parallel to the perpendicular Y that is orthogonal to the axis X of the screw shaft, that is, the lead angle θ is 0° A plurality of grooves 23 are provided along the circumferential direction of the screw shaft 16, and the groove bottoms 23a are substantially straight (see FIG. 5). , this groove 23 is connected to the screw shaft 1 so that the inside of each groove 23 communicates with each other.
As a result, these grooves 23 form one spiral groove 2.
4 is formed.

In this embodiment, as shown in FIG. 5, eight grooves 23 are equally spaced over one circumference (360 degrees) of the screw shaft 16, and the rotation angle of the screw shaft 16 is 0.゜，45°，135゜，
Rotation stop positions of the stepping motor 1 are set corresponding to eight positions of 180°, 225°, 270°, and 315°, and the rotation stop angle is set so as to be at the center of each groove portion 23. ing.

That is, the permanent magnet 15 fixed to the screw shaft 16 and the groove 23 of the shaft 16 are connected to the sixth
As shown in the figure, the magnetization point of the permanent magnet 15 is set on a straight line connecting the center point A of each groove bottom 23a and the center 0 of the shaft 16, and corresponds to the center point A of each groove bottom 23a. and alternately N, S
The poles are magnetized. Therefore, the rotation stop angle of the stepping motor 1 at which the magnetized point of the permanent magnet 15 stops facing the yoke 14 always corresponds to the center of the groove 23.
The pointed end 9a of the engaging member 9 of the carriage 5 that engages with the carriage 5 is located at the center of the groove 23 at the stop position.

In the above configuration, the stepping motor 1
is rotated by a desired number of steps and stopped at the above-mentioned stopping angle, the engaging member 9, that is, the carriage 5 is transferred by an amount corresponding to the amount of rotation of the screw shaft 16, and then stopped. At this time, each stop position is at the center of the groove 23 with an advance angle of 0°, which is indicated by a dashed line as shown in FIG. 7, so the stop position is always accurate.

In the above embodiment, the screw shaft 16 and the permanent magnet 15 are fixed together, but it is sufficient that the screw shaft 16 and the permanent magnet 15 rotate together through separate members.
The point is that the center point of the groove 23 of the screwshaft 16 and the magnetization point of the permanent magnet 15 only need to correspond one-to-one, and the number of yokes can be selected depending on the difference in phase excitation. Further, although not described in detail in the embodiment, the shape of the permanent magnet 15 can be changed in various ways, and the pre-magnetized permanent magnet 15 can be easily aligned by fitting it into the slotted part of the screw shaft 16. It is. Furthermore, the engaging element 9 can also be deformed into a double-sided beam type instead of a cantilever type as in the embodiment, and if the tip portion 9a is also made straight, the groove portion 23
This makes the engagement relationship even more stable.

[Effect of idea]

As described above, according to the present invention, the magnetization point of the permanent magnet of the stepping motor corresponds to the center of each groove of the screw shaft.
The stop position of the engaging element that engages with the groove is precisely regulated at the center of the groove with an advance angle of approximately 0°, and the carriage stops at an accurate and reliable position, which significantly improves the reliability of writing and reading of the magnetic head. It has a remarkable effect.

[Brief explanation of drawings]

1 and 2 relate to a conventional example, where FIG. 1 is an explanatory diagram of the carriage transfer mechanism, FIG. 2 is an explanatory diagram showing the relationship between the screw shaft and the moving distance of the carriage, and FIGS. 3 to 7. The figure relates to one embodiment of the present invention, and FIG. 3 is an explanatory diagram showing a carriage transfer mechanism;
Figure 4 is an enlarged view of the main parts of the screw shaft, Figure 5
FIG. 6 is an explanatory diagram showing the relationship between the groove of the screw shaft and the permanent magnet, and FIG. 7 is an explanatory diagram showing the relationship between the rotation angle of the screw shaft and the transport distance of the carriage. . DESCRIPTION OF SYMBOLS 1... Stepping motor, 5... Carriage, 6... Magnetic head, 9... Engagement element, 9a...
Point, 15... Permanent magnet, 16... Screw shaft, 23... Groove, 23a... Groove bottom, 2
4...Spiral groove.

Claims (1)

[Scope of utility model registration request] A disk recording device in which an engaging element of a carriage equipped with a magnetic head for writing and reading is engaged with a screw shaft, and the screw shaft is rotated by the driving force of a stepping motor to linearly feed the carriage at a predetermined pitch. In the reproducing device, a permanent magnet serving as a rotor of the stepping motor and the screw shaft are configured to rotate together, and a shaft having an advance angle of approximately 0° and a substantially linear shape is provided on the outer circumference of the axis of the screw shaft. A plurality of grooves each having a groove bottom are formed at equal intervals along the circumferential direction, and these grooves are sequentially shifted in the axial direction to form one spiral groove. The disc recording/reproducing device is characterized in that magnetization points are set at equal intervals corresponding to circumferential intervals of the grooves.