JPH0362368A - Actuator for magnetic recording and reproducing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) This invention relates to an actuator for a magnetic recording/reproducing device.

(Prior art) In recent years, magnetic recording and reproducing devices using small magnetic disks with media sizes of 5 inches, 3.5 inches, and even smaller media sizes have been used in desktop-type or laptop-type personal computers, handheld word processors, etc. It has become lightweight, small or thin, and requires fewer assembly steps.
There is a demand for cost reduction by reducing the number of component parts.

For this reason, in small magnetic recording and reproducing devices, the rotary type is the mainstream actuator, which is a component of the mechanism for moving the magnetic head relative to the magnetic disk surface, because it is easier to downsize than the linear type. occupies . Among these, actuators that use a voice coil motor with a large force coefficient and good response are widely used for those that require high-speed seeking.

In a thin type magnetic recording/reproducing device where the height of the device is particularly limited, a voice coil motor is used, as shown in FIG. 4 to FIG.

FIG. 4 shows a lower yoke 10 attached to the base 101 of the main body of the device.
3 is attached, an upper yoke 105 is provided facing this yoke 103, magnets 107 and 109 are attached to the upper and lower yokes 105 and 103, respectively, and this magnet 1
A flat coil 111 is provided between 07 and 109. The flat coil 111 is wound around the proximal end of an actuator arm that is swingably supported in parallel to the base 101 on a pivot shaft (not shown) fixed to the base 101, and a magnet is attached to the tip of the actuator arm. A head is provided.

The flat coil 111, magnets 107, 109, and yokes 103, 105 constitute a voice coil motor that swings the actuator arm.
The actuator arm swings by controlling the current flowing through the magnetic head 1, and accordingly the magnetic head moves over a magnetic disk (not shown) to perform a recording/reproducing operation at a predetermined data track position.

FIG. 5 shows the lower magnet 10 in the one shown in FIG.
9 is omitted to make the device thinner.

In order to further reduce the thickness of the structure shown in FIGS. 4 and 5, it is necessary to reduce the thickness of the magnet, yoke, coil, etc. As for the magnet, it is being made thinner by using a highly efficient magnet with a large maximum energy product.

On the other hand, even if the magnet thickness is reduced in this way, in order to maintain the same total magnetic flux and form an equivalent magnetic circuit, a yoke with a predetermined cross-sectional area is required. Since there is a limit to the magnetic permeability of the yoke, it cannot be expected that the yoke will become much thinner.

Further, in order to reduce the thickness of the drive coil portion, bobbinless coils that do not require a bobbin for holding the coil are widely used.

In the conventional example shown in FIG. 6, the lower yoke 103 in the one shown in FIG. has the function of the lower yoke 103.

(Problems to be Solved by the Invention) In addition to these problems related to thinning, the conventional device has a read/write circuit that processes signals for recording and reproducing the magnetic head attached to the actuator arm.
Since it is provided on a wiring board (not shown) adjacent to the actuator arm, the wiring work between the magnetic head of the actuator arm, which is a moving member, and the read/write circuit of the wiring board, which is a stationary member, is troublesome and the wiring length is long. Therefore, there is a problem in that the production cost increases.

This invention was proposed to solve the above-mentioned conventional problems, and by forming a metal core printed wiring board equipped with a read/write circuit using a magnetic head as the yoke and actuator arm of the drive motor, it is possible to improve the device. The purpose is to simplify and reduce the thickness of the device.

[Structure of the invention]

(Means for Solving the Problem) In order to solve the above-mentioned problem, the present invention provides a metal core printed wiring board on the leading end side on which part or all of a read/write circuit for recording and reproducing data by a magnetic head is mounted. A magnetic head is installed on the base end, a coil is installed on one side of the base end, and this metal core printed wiring board is used as an actuator arm, and magnetic flux is transmitted through the coil to the side of the device body opposite to the metal core printed wiring board. A configuration in which a yoke to be magnetized is provided, a magnet is provided between the yoke and the coil, and is attached to the yoke, and the actuator arm is swingable by the action of the magnetic field generated in the coil and the magnetic field generated in the magnet. And so.

(Operation) When a current is supplied to the coil, the metal core printed wiring board that constitutes the actuator arm swings in a predetermined direction due to the magnetic field generated by this and the magnetic field formed by the magnet, metal core printed wiring board, and yoke, and the magnetic Data is recorded and reproduced by the head.

Since the actuator arm functions as a yoke that transmits magnetic flux, the drive unit is thinner than the conventional type in which a yoke is provided separately.

Since part or all of the data read/write circuit is provided on the metal core printed wiring board that forms the actuator arm, there is no need to provide a separate read/write circuit board, which reduces the number of parts. Moreover, the wiring between this circuit and the magnetic head is shortened and simplified, which greatly helps in reducing costs.

(Example) Next, embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a plan view of the mechanism section of the magnetic recording/reproducing apparatus, and FIG. 2 shows a longitudinal side view of the actuator drive section of FIG. 1, that is, the voice coil motor.

This magnetic recording/reproducing device has a structure in which a magnetic disk 5 is rotated by a spindle motor 3 attached to a base 1 of the device body made of aluminum die-casting or synthetic resin.

A shaft 7 is installed upright on the base 1, and this shaft 7
The inner race of the bearing 9 is fitted onto the inner race of the bearing 9, and the intermediate portion of the actuator arm 13 is attached to the outer race side of the bearing 9 with a screw 11. Therefore, the actuator arm 13 can swing around the shaft 7 along the surface of the magnetic disk 5. This actuator arm 13 is made of a metal core printed wiring board based on a magnetic metal plate, and has a sufficiently large value of magnetic permeability.

A head arm 15 is attached to the tip side of the actuator arm 13 with a screw 17.
One magnetic head is attached to the tip.

A read/write circuit 21 that processes a recording/reproduction signal generated by one magnetic head moving on the magnetic disk 5 is mounted on a metal core printed wiring board that constitutes the actuator arm 13, and one magnetic head has a read/write circuit.・
It is connected to the write circuit 21 by a lead wire 23.

A coil 25 is attached to the base end side of the actuator arm 13 opposite to the side where the helad arm 15 is attached.

Coil 25 and actuator arm 13 near this side
A yoke 27 is located above and straddles these.
Attached to the base 1 by screws 29 and yoke 27
and the magnet 31 interposed between the coil 25 and the coil 25.
It is attached to the lower surface of the yoke 27. These yokes 27
, the magnet 31, the coil 25, and the actuator arm 13 constitute a voice coil motor that drives the actuator arm 13. By controlling the current flowing through the coil 25, the actuator arm 13 swings around the shaft 7 and performs a predetermined seek. Action will be taken.

In this way, since the actuator arm 13 around which the coil 25 is wound is formed from a metal core printed wiring board which is a magnetic material, this actuator arm 13 can function as a yoke for the coil 25.
The drive unit is thinner than conventional devices in which such a yoke is provided separately from the actuator arm.

Since part or all of the data read/write circuit 21 is provided on the metal core printed wiring board forming the actuator arm 13, there is no need to provide a separate read/write circuit board, which reduces the number of parts. In addition, the lead wire 23 connecting this circuit and one magnetic head is shortened, wiring is simplified, and the mounting cost can be significantly reduced compared to conventional devices.

In the embodiment shown in FIG. 2, the base 1 is made of, for example, aluminum die-casting or a synthetic resin plate in order to reduce weight.
7, and the magnet 31 needs to be attached to the base 1 via this yoke 27.

On the other hand, in the second embodiment, in which the vertical side view of the voice coil motor is shown in FIG. Therefore, the yoke 27 in the first embodiment shown in FIG. 2 is unnecessary in this second embodiment. That is, the base 41, the magnet 31,
The coil 25 and the actuator arm 13 constitute a voice coil motor.

Therefore, in this second embodiment, the yoke 27 of the first embodiment shown in FIG. 2 is unnecessary, and the thickness can be further reduced by this thickness. In FIG. 3, reference numeral 43 is a cover.

The configuration of the embodiment described above can be applied not only to the magnetic disk device illustrated in FIG. 1 but also to other storage devices including actuators having flat coils and transducers for recording and reproducing.

〔Effect of the invention〕

As is clear from the above, according to the configuration of this invention,
Part or all of the data read/write circuit using the magnetic head is provided on the metal core printed wiring board that forms the actuator arm, so there is no need to provide a separate read/write circuit board, which reduces the number of parts. In addition, the wiring connecting the read/write circuit to the magnetic head that moves integrally with the magnetic head is shortened and simplified, thereby reducing manufacturing costs. Since the actuator arm functions as a yoke that transmits magnetic flux, the drive section of the actuator arm can be made thinner than in conventional devices in which the yoke is provided separately from the actuator arm.

[Brief explanation of drawings]

Figure 1 is a plan view of the mechanical part of the magnetic recording and reproducing device, Figure 2 is a longitudinal cross-sectional side view of the voice coil motor in Figure 1, and Figure 3 is a side view of the voice coil motor in Figure 1.
The figure is a longitudinal sectional side view of a voice coil motor in a second embodiment, and FIGS. 4, 5, and 6 are longitudinal sectional side views of a voice coil motor in a conventional device. 13...Actuator arm (metal core printed wiring board) 1...Magnetic head 1...Read/write circuit 5...Coil 7...Yoke...Magnet

Claims (1)

[Claims] A magnetic head is installed on the tip side of a metal core printed wiring board on which part or all of the read/write circuit for recording and reproducing data is mounted using the magnetic head, and a coil is installed on one side of the base side. A printed wiring board is used as an actuator arm, and a yoke is provided to transmit magnetic flux to the device body side opposite to the metal core printed wiring board with respect to the coil, and a magnet is placed between the yoke and the coil and attached to the yoke. An actuator for a magnetic recording and reproducing device, characterized in that an actuator arm is swingable by the action of a magnetic field generated in a coil and a magnetic field generated in a magnet.