JPH03212823A - Head transfer device - Google Patents

Abstract

PURPOSE:To improve the dynamic characteristic of a movable part by making the movable part of a head transfer device light weight, and making a driving coil approach the center of gravity of the movable part. CONSTITUTION:A slide supporting part is provided at the movable board 32a of the movable part 32, and is connected freely slidably to a guide part 27 fixed at a base 21. Also, a supporting part which supports the connecting member 33 of the movable part 32 is provided at the base 21, and the movable part 32 can be freely moved in the radius direction of a recording medium 29 by energizing the driving coil 35 of the movable part 32. In other words, miniaturization and light weight can be realized by providing only one driving coil 35 for the movable part 32, and also, moment due to the unbalance of a driving force can be suppressed by making the driving coil 35 approach the center of gravity of the movable part 32. In such a way, it is possible to form the head transfer device with superior dynamic characteristic responsive to fast access.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a recording/reproducing head moving device used in an information recording/reproducing apparatus that records and reproduces information on a disk-shaped recording medium.

[Conventional technology]

2. Description of the Related Art There is a strong demand for information recording and reproducing devices that record and reproduce information on recording media to shorten data access time and to downsize them. Data access time is achieved by moving the recording/playback head to a desired position on the surface of the recording medium at high speed. It is necessary to reduce the weight of the movable part itself and make the thrust more efficient. In a conventional head transfer device, for example, as shown in FIG. 5, an optical disk 2 is rotatably held on top of a spindle motor 1. A movable part 3 is held movably in the radial direction of the optical disc 2 along a pair of guide shafts 4. The central portion 3a of the movable portion 3 has a rectangular parallelepiped shape, and rollers 5 are rotatably attached to the front and rear sides of the movable portion 3 so as to sandwich the guide shaft 4 therebetween. A drive coil bobbin 7, around which a drive coil 6 is wound, is provided on both sides of the center portion 3a.
It is fixed by eight upper and lower protrusions extending laterally from a. Further, an optical head 8 is fixed on the central portion 3a of the movable portion 3. A pair of rectangular parallelepiped magnetic corks 10 having a hollow center yoke 9 parallel to the guide shaft 4 are fixed on both sides of the movable part 3. In this figure, a part of the magnetic yoke 10 is shown cut away. A rectangular cylindrical drive coil bobbin 7 is fitted around the center yoke 9. Further, a permanent magnet 11 is attached to the inner surface of the hollow upper part of the magnetic yoke 10. And this permanent magnet 1
1, a magnetic yoke 10, and a drive coil 6 fixed to the movable part 4 constitute a linear motor, which enables the optical head 8 on the movable part 4 to be moved in the radial direction of the optical disk 2.

(Problem to be solved by the invention) However, in such a conventional head transfer device, two
Two magnetic circuits are disposed on both sides of the two guide shafts 4, and therefore two drive coils 6 must be disposed at positions surrounding the center yokes of the magnetic circuits on both sides.

Therefore, since the distance between the drive coils 6 is larger than the distance between the two guide shafts 4, the moment due to the imbalance of the driving forces of the two magnetic circuits increases, and the dynamic characteristics of the movable part deteriorate. There were drawbacks. Also, there are 2 moving parts
Since it has two drive coils, the mass of the movable part is large, and there are problems in that it is difficult to reduce power consumption.

The present invention has been made in view of the problems of the conventional head transfer device.The present invention reduces the weight of the movable portion of the head transfer device and moves the drive coil closer to the center of gravity of the movable portion, thereby increasing the movement of the movable portion. The technical challenge is to improve the characteristics.

[Means to solve the problem]

The present invention is used in an information recording and reproducing device in which a drive means for rotationally driving a disk-shaped information recording medium is held on a base,
A head moving device that moves a head for recording and reproducing information in the radial direction of an information recording medium, which comprises at least two heads arranged parallel to each other along a predetermined radial direction of the recording medium and fixed to a base. a guide part, a movable base to which the head is fixed on the upper surface, a drive coil, a connecting member fixed to the center of the side surface of the movable base and connecting the movable base and the drive coil;
and a movable part that is fixed to the movable base and has a sliding support part that slides the movable base in a predetermined radial direction of the recording medium while holding the guide part, and a connecting member of the movable part that is fixed to the base. a support part that holds the medium movably in the radial direction; and a magnetomotive force means that is fixed on the base along the sliding direction of the movable part and drives the movable part in the radial direction of the recording medium by energizing a drive coil. It is characterized by comprising the following.

[Effect]

According to the present invention having such characteristics, the movable base of the movable part is provided with a sliding support part, and is slidably connected to the guide part fixed to the base.

The base is also provided with a support part that holds the connecting member of the movable part, and by energizing the drive coil of the movable part, the movable part can be freely moved in the radial direction of the recording medium.

〔Example〕

An embodiment of the head transfer device of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view of a head transfer device in one embodiment of the present invention.

In this figure, the base 21 consists of three rectangular parallelepipeds 21a to 21c.
It has a U-shaped shape in which the central rectangular parallelepiped 21a and the side rectangular parallelepipeds 21b and 21C are connected, and rectangular parallelepiped-shaped shaft fixing parts 21d and 21e are formed to protrude from the upper surface portion. has been done. Furthermore, a partition plate 22 is fixed at right angles to the center of the rectangular parallelepipeds 21b and 2IC on the sides of the base 21. The partition plate 22 has rectangular parallelepiped-shaped shaft fixing parts 22a and 22b that protrude from above the base 21.

Further, a roller 23 fixed to the upper surface of the central portion of the partition plate 22 is provided so that its rotation axis is perpendicular to the base 21.

Also, one shaft fixing portion 22b of the partition plate 22 is a rectangular parallelepiped 21c.
It is fixed in such a way that it rides on the top surface of the. Partition plate 2
A notch is provided in the protrusion 22c extending perpendicularly from 2 in the front direction, and a roller 24 is fixed to this notch so that its rotation axis is parallel and horizontal to the partition plate 22. Further, a preload leaf spring 25 is fixed on the shaft fixing part 22b of the partition plate 22, and its rotation axis is fixed to the shaft fixing part 22b of the partition plate 22.
A roller 26 is mounted at an angle with respect to the horizontal plane of 2. These rotatably held rollers 23, 24, 26
This constitutes a support section that supports a guide section, which will be described later. A pair of fixed guide shirts) 27a and 2Tb are attached to the side surfaces of the respective shaft fixing parts 21d and 22a and the shaft fixing part 21e.
, 22b, and the pair of fixed guide shafts 27a, 27b constitute a guide section. As shown, a spindle motor 28 is fixed to a central rectangular parallelepiped 21a of the base 21, and the optical disc 29 is held by its flange 28a so that the disc surface thereof is horizontal. Further, the spindle motor 28 is a driving means for rotationally driving the optical disk 29. On the other hand, the magnetic yoke 30 has a comb shape with three gaps cut into it, and is fixed to an end on the base 21 with the cut surface facing the spindle motor 28 side.

Rectangular parallelepiped permanent magnets 31 are attached to the inner surfaces on both sides of the two outer gaps of the magnetic yoke 30.
The magnetic yoke 30 and the permanent magnet 31 constitute magnetomotive force means for driving a movable part 32, which will be described later.

FIG. 2 shows the movable part 32 of the head transfer device in this embodiment.
FIG. In this figure, the movable part 32 includes a rectangular parallelepiped movable base 32a and an optical disc 2 on the front side of the movable base 32a.
9 radially mounted movable guide shaft 33;
and a drive coil bobbin 34 attached to the movable guide shaft 33. The movable guide shaft 33 is a connecting member that connects the movable base 32a and the drive coil bobbin 34. Further, the drive coil bobbin 34 has a third
A drive coil 35 is wound as shown in the figure. Fourth
The figure is a front view of the movable table 32a, and an optical head 36 is fixed to the upper part of the movable table 32a. The movable table 32a has a cutout at the lower right corner, and a rectangular parallelepiped cutout at the left corner from the center, and a roller 37 is rotatably attached to the cutout surface. A preload plate spring 38 with one end bent is fixed to the bottom portion thereof, and a roller 39 is rotatably attached to the bent portion 38a.

Above the rollers 37 and 38, rollers 40 and 41 are rotatably attached to the side surface of the movable base 32a, respectively. These rollers 37, 39, 40° 41 constitute a sliding support section that holds the aforementioned guide section. That is, the fixed guide shaft 27a is held between the rollers 40 and 37, and the fixed guide shaft 27b is held between the rollers 41 and the roller 39 of the preload leaf spring 38 with a pressurized state.

Next, FIG. 3 shows a partial front view of the movable part 32. In this figure, the drive coil bobbin 34 has a rectangular cylindrical shape and has a column extending from the upper center to the center and fixing the movable guide shaft 33, and an opening having an Ω-shaped notch 34a on the lower surface is provided at the center of the column. This opening allows the movable guide shaft 33 to pass through, and the notch 34a allows the drive coil bobbin 34 to pass through the roller 2 when the movable part 32 moves.
This is to avoid contact with 4. The drive coil bobbin 34 is fixed at a position at least three or more lengths Ll from the axial end of the movable guide shaft 33 within the movement range of the movable portion 32. Also, the movable base 32a and the drive coil bobbin 3
The interval L2 of 4 needs to be at least longer than the movement range of the movable part 32.

In the head transfer device configured as described above, when the coil 35 is energized, the movable part 32 is integrated with the attraction or repulsion force with the permanent magnet 31 attached to the magnetic yoke 30, and moves the optical disk 29 on the base 21. The optical head 36 on the movable part 32 can be moved by sliding in the radial direction.

In this embodiment, the sliding support part was a rolling bearing using rollers, but if the fixed guide shaft is made of a plate-like member or a square cylindrical member, a groove in the direction of movement can be provided there to prevent sliding. It may also be a sliding bearing.

Further, although the supporting portion is a rolling bearing using rollers fixed on the base, it may be a sliding bearing using a plate-like member or the like. Furthermore, it goes without saying that the same operation and effect can be obtained even if a plate-shaped member or the like is used as the connecting member consisting of the movable guide shaft attached to the movable table.

〔Effect of the invention〕

As described above in detail, according to the present invention, the drive/coil of the movable part is integrated into one, simplifying the structure, and at the same time realizing reduction in size and weight. Furthermore, by bringing the drive coil close to the center of gravity of the movable part, it is possible to suppress the moment due to imbalance in the drive force, and it is possible to provide a head transfer device with excellent dynamic characteristics that can handle high-speed access.

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view of a head transfer device according to an embodiment of the present invention, Fig. 2 is a perspective view of a movable part of this embodiment, and Fig. 3 is a partial front view showing the drive coil and base of this embodiment. , FIG. 4 is a front view of the movable base of this embodiment, and FIG. 5 is a perspective view of a conventional head transfer device. 21-...-base 23 24,25.37,3
9, 40, 41-=-・Roller 27a,
27b-=Ide shaft 28-- Spindle motor 29-- Optical disk 30--
Magnetic Yaw 32--Movable part 32 a----
--- Movable base 33 --- Movable guide shaft 34
--- Drive coil bobbin 35 --- --- Drive coil 36 --- --- Optical head

Claims (4)

[Claims] (1) A head used in an information recording/reproducing device in which a driving means for rotationally driving a disk-shaped information recording medium is held on a base, and the head for recording/reproducing information is moved in the radial direction of the information recording medium. A transfer device, comprising: at least two guide portions arranged parallel to each other along a predetermined radial direction of the recording medium and fixed to the base; a movable table for fixing a head on an upper surface; a drive coil; a connecting member fixed to the center of a side surface of the movable base to connect the movable base and the drive coil; and a connecting member fixed to the movable base to slide the movable base in a predetermined radial direction of the recording medium while holding the guide part. a movable part having a sliding support part for moving the movable part; a support part fixed on a base and holding a connecting member of the movable part movably in a radial direction of a recording medium; and a movable part having a sliding support part for moving the movable part on the base. 1. A head transfer device comprising: magnetomotive force means fixed along a direction, and driving the movable portion in a radial direction of the recording medium by energizing the drive coil. (2) The head transfer device according to claim 1, wherein the connecting member is constituted by either an axial guide shaft or a plate-shaped member. (3) The head transfer device according to claim 1, wherein the sliding support portion is configured by either a rolling bearing or a sliding bearing. (4) The head transfer device according to claim 1, wherein the support portion is configured by either a rolling bearing or a sliding bearing.