JPH0574070A - Magnetic head positioning mechanism - Google Patents

Abstract

PURPOSE:To prevent a read/write error by the off-tracking of the magnetic head caused by the transitional damped vibration of the magnetic head occurring immediately after the optional position of a cylinder on a magnetic disk is decided by the magnetic head position deciding mechanism. CONSTITUTION:A viscoelastic plate 12 is adhered on a borderline between an R/WFP 10 formed in a convex shape and whose one part is fixed to the side of an arm 2 and the side of a magnetic circuit 7 and the bending and fixing parts of a coil FPC 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head positioning mechanism in a magnetic disk device.

[0002]

2. Description of the Related Art As shown in FIG. 3, a magnetic head positioning mechanism of a conventional magnetic disk device includes a magnetic head 1 for recording / reproducing data, an arm 2 for supporting the magnetic head 1,
A holder 3 for loading the arms 2 at a predetermined interval, a bearing 4 for rotatably supporting the holder 3, a central shaft 5 for supporting an inner ring of the bearing 4, and a holder 3 fixed to the holder 3 and driven integrally with the arm 2. Coil 6, a magnetic circuit 7 disposed above and below the coil 6, a lower substrate 8 that supports the central axis 5 and a lower portion of the magnetic circuit 7, an upper substrate 9 that supports the central axis 5 and an upper portion of the magnetic circuit 7, and an arm. Of the read / write flexible printed board (hereinafter referred to as R / WFPC) 10 and the arm 2 which are fixed to the side surface of 2 and the side surface of the magnetic circuit 7 and are formed in a convex shape to transmit recording / reproducing signals from the magnetic head 1. The coil flexible printed board (hereinafter referred to as coil FPC) 11 is fixed to the side surface and the side surface of the magnetic circuit 7 and is formed in a convex shape to supply a control current to the coil 6. R / WFPC10 bend and coil F
As shown in FIG. 4, the PC 11 is composed of a polyimide 13, an adhesive layer 14 and a copper foil 15.

In the conventional example shown in FIG. 3, an external control circuit (not shown) applies a control current to the coil 6 via the coil FPC 11 to cause interference between the magnetic field generated in the coil 6 and the magnetic field of the magnetic circuit 7. The coil 6, the holder 3, the bearing 4, the arm 2 and the magnetic head 1 (hereinafter referred to as the movable portion) are rotated around the central axis 5 by the force (hereinafter referred to as the driving force) generated by the above, and are rotated at high speed. The magnetic head 1 is positioned on a designated cylinder on a magnetic disk (not shown) to magnetically record and reproduce data. The recording / reproducing signal from the magnetic head 1 is R / WFPC.
It is transmitted to the external control circuit via 10. Furthermore, the R / WFPC1 is rotated according to the rotational movement of the movable part around the central axis 5.
0 and the convex bent portion of the coil FPC11 are deformed.

[0004]

The above-mentioned conventional magnetic head positioning mechanism, according to an instruction from the external control circuit,
As the magnetic head is continuously and repeatedly positioned between the inner cylinder and the outer cylinder on the magnetic disk, the bending portions of the R / WFPC and the coil FPC are continuously deformed, so that the driving force is increased. Other forces (hereinafter referred to as external forces) are generated and act on the movable portion of the magnetic head positioning mechanism. Therefore, immediately after the magnetic head is positioned in the inner cylinder or the outer cylinder on the magnetic disk by the command from the control circuit, the magnetic head transiently attenuates and vibrates off the track due to the external force described above. There is a problem that the magnetic head causes a read / write error.

[0005]

A magnetic head positioning mechanism according to the present invention has a plurality of arms for fixing and supporting a magnetic head for recording and reproducing data at its tip, and a plurality of arms at predetermined intervals. A holder for holding and loading, a bearing for rotatably supporting the holder, a central shaft for supporting an inner ring of the bearing, a coil fixed to the holder and driven integrally with the plurality of arms, Magnetic circuits arranged above and below the coil, a lower substrate supporting the central axis and a lower portion of the magnetic circuit, an upper substrate supporting the central axis and an upper portion of the magnetic circuit, and the plurality of arms. A first flexible printed board for fixing a part to a side surface of the magnetic circuit and a side surface of the magnetic circuit and having a convex bent portion between the fixed portions and transmitting a recording / reproducing signal from the magnetic head; A magnetic head having a second flexible printed board, a part of which is fixed to the side surface of each arm and the side surface of the magnetic circuit and which has a convex bent portion between the fixed portions and supplies a control current to the coil. The positioning mechanism includes a viscoelastic plate disposed on at least one of a fixing portion of the first and second flexible printed boards to a side surface of the plurality of arms and a fixing portion to a side surface of the magnetic circuit. ..

The first and second flexible printed boards may be integrated.

[0007]

The present invention will be described below with reference to the drawings.

1A and 1B are a front view and a vertical sectional view of an embodiment of a magnetic head positioning mechanism of the present invention, respectively. In this embodiment, magnetic recording and reproduction of data is performed at the tip. An arm 2 that fixes and supports the magnetic head 1, a holder 3 that holds and mounts the arm 2 at a predetermined interval, a bearing 4 that rotatably supports the holder 3 and a central shaft 5 that supports an inner ring of the bearing 4. And a coil 6 fixed to the holder 3 and driven integrally with the arm 2, and a magnetic circuit 7 arranged above and below the coil 6.

The upper and lower parts of the central shaft 5 and the magnetic circuit 7 are fixed by an upper substrate 9 and a lower substrate 8, respectively. The R / WFPC 10 that transmits a recording / reproducing signal from the magnetic head 1 to an external control circuit (not shown) and the coil FPC 11 that supplies a control current to the coil 6 from the external control circuit,
R / WFPC10 and coil FPC11 formed in a convex shape
A part is fixed to the side surface of the arm 2 and the side surface of the magnetic circuit 7 by the metal fittings bonded to each. Further, a viscoelastic plate 12 is adhered to a boundary between the fixed portion and the bent portion of the R / WFPC 10 and the coil FPC 11 on the side surface of the arm 2 and the side surface of the magnetic circuit 7.

The viscoelastic plate 12 has a characteristic of moving the resonance frequency of the adhered object to the high frequency side of the frequency band to attenuate the amplitude. FIG. 2 shows a comparison of changes over time in the damping vibration of the position signal of the magnetic head 1 before and after bonding the viscoelastic plate 12.
The upper diagram (a) is before the viscoelastic plate is bonded, and the lower diagram (b)
Shows the state after adhesion of the viscoelastic plate, the dotted line in the figure is the standard, and the voltage is converted as displacement. As shown in FIG. 2, the magnetic head 1 is bonded by bonding the viscoelastic plate 12.
The transient damped oscillation of the position signal is suppressed within the standard.

[0011]

As described above, according to the present invention, the first and second flexible printed boards are adhered to the boundary between the bent portion and the fixed portion to move the resonance frequency to the high frequency side of the frequency band and vibrate. Since the viscoelastic plate that suppresses the magnetic head is provided, transient damping vibration of the magnetic head that occurs immediately after the magnetic head is positioned on the inner cylinder or outer cylinder on the magnetic disk is suppressed, and the magnetic head is turned off. This has the effect of avoiding read / write errors due to tracks.

[Brief description of drawings]

1A and 1B are a front view and a vertical sectional view, respectively, of an embodiment of the present invention.

FIG. 2 is a waveform diagram of a position signal of the magnetic head before and after bonding the viscoelastic plate in the embodiment of FIG.

3A and 3B are a front view and a vertical sectional view of a conventional magnetic head positioning mechanism.

FIG. 4 is an R / WFPC and a coil FPC in FIG.
It is sectional drawing of the bending part.

[Explanation of symbols]

 1 Magnetic Head 2 Arm 3 Holder 4 Bearing 5 Center Shaft 6 Coil 7 Magnetic Circuit 8 Lower Substrate 9 Upper Substrate 10 R / WFPC 11 Coil FPC 12 Viscoelastic Plate

Claims (2)

[Claims] 1. A plurality of arms for fixing and supporting a magnetic head for recording and reproducing data at the tip, a holder for mounting the plurality of arms at a predetermined interval, and a rotatable holder. A bearing that supports the bearing, a central shaft that supports the inner ring of the bearing, a coil fixed to the holder and driven integrally with the plurality of arms, and magnetic circuits arranged above and below the coil. A lower substrate supporting the central axis and the lower part of the magnetic circuit, an upper substrate supporting the central axis and the upper part of the magnetic circuit, and a part fixed to side surfaces of the plurality of arms and side surfaces of the magnetic circuit. A first flexible printed board having a convex bent portion between these fixed portions and transmitting a recording / reproducing signal from the magnetic head, and a part of the side surface of the plurality of arms and the side surface of the magnetic circuit. To A magnetic head positioning mechanism comprising: a second flexible printed board that is fixed and has a convex bent portion between these fixed portions and supplies a control current to the coil. A magnetic head positioning mechanism comprising: a viscoelastic plate disposed on at least one of a side surface fixing portion and a magnetic circuit side surface fixing portion of the plurality of arms. 2. The magnetic head positioning mechanism according to claim 1, wherein the first and second flexible printed boards are integrated.