JP2000331301A - Magnetic head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable signals to be properly read out by effectively suppressing propagation of noise to a circuit board attached to the rotary drum side. SOLUTION: The ground connection area 34, which is electrically connected to the ground pattern layer of a circuit board 30, is electrically connected to the drum part 3a or flange part 3b of a rotary drum 3 through a connecting means such as a conductive spring member 40. Thus, the circuit pattern layer formed with the power circuit, regeneration circuit, etc., of the circuit board 30 is shielded with the ground pattern layer and the rotary drum 3.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a fixed drum and a rotating drum, and by rotating the rotating drum, a magnetic head element mounted on the rotating drum is slid on the magnetic tape. The present invention relates to a magnetic head device for writing and / or reading signals.

[0002]

2. Description of the Related Art Conventionally, a magnetic head element mounted on a rotating drum is obliquely slid on a running magnetic tape to record and reproduce signals on the magnetic tape. A scanning / recording method has been proposed.

In the helical scan method, the magnetic head element slides on a running magnetic tape at a high speed to write and / or read out signals, so that the relative sliding speed between the magnetic tape and the magnetic head element is reduced. It has the advantage that a high and high data transfer rate can be obtained.

A magnetic head device for writing and / or reading signals to and from a magnetic tape by the helical scan method comprises a device body having a substantially cylindrical outer shape having a fixed drum and a rotating drum, and a rotation device for rotating the device body. And a magnetic head element mounted on the drum side. The magnetic head element is attached to a head base, and is attached to a rotary drum such that a tip end of the magnetic head element projects slightly outward from a peripheral surface of the apparatus main body. On the other hand, when the magnetic tape is tilted at a predetermined tilt angle with respect to a direction orthogonal to the rotation axis of the rotary drum, for example, 180
It is wound around the peripheral surface of the device body at a winding angle of degrees.

In this magnetic head device, the rotating drum is rotated while the magnetic tape is wound around the peripheral surface of the device main body, so that the magnetic head element attached to the rotating drum is inclined on the magnetic tape. It slides and writes and / or reads signals to and from the magnetic tape.

In recent years, in this helical scan type magnetic head device, a magnetoresistive effect type magnetic head element (hereinafter referred to as MR) used as a reproducing magnetic head element in a hard disk device or the like as a reproducing magnetic head element. A technique using a head has been proposed.

An MR head is a magnetoresistive element (hereinafter, referred to as a magnetoresistive element).
It is called an MR element. A) a magnetic head element for reading a signal recorded on a magnetic recording medium by utilizing the magnetoresistive effect. For example, a pair of substrates made of a soft magnetic material are joined and integrated via a gap, and the magnetoresistive An MR element exhibiting an effect is formed as a thin film. In this MR head, the track width is determined by the width of the MR element to be formed as a thin film.
Since the element is exposed from the surface facing the magnetic recording medium, it has a feature that the reproduction sensitivity is high.

In a magnetic head device for writing and / or reading signals by a helical scan method, a recording head can be made narrower by using an MR head having the above-mentioned characteristics as a reproducing magnetic head element. Therefore, it is expected that signal writing and / or reading can be performed at higher density.

In a magnetic head device for writing and / or reading signals by a helical scan method, when an MR head is used as a reproducing magnetic head element, a sense current which is a constant current for driving the MR head is supplied. It is necessary to supply to the MR head. It is desirable that the supply of the sense current to the MR head be performed using a rotary transformer which is a non-contact type transmission device provided between the fixed drum and the rotating drum. This rotary transformer transmits a recording signal supplied from the fixed drum to the rotating drum, and transmits a reproduction signal read by a magnetic head element mounted on the rotating drum to the fixed drum. In the case where an MR head is used as a magnetic head element for reproduction, a magnetic head device supplies a sense current to the MR head by using a rotary transformer for transmitting a signal between a fixed drum and a rotating drum. By doing so, there is no need to add a new transmission device for supplying the sense current, and the configuration can be simplified.

However, since the rotary transformer transmits only alternating current, in order to supply a sense current, which is a constant current, to the MR head, the alternating current transmitted via the rotary transformer is converted to direct current and supplied to the MR head. There is a need. For this reason, in order to supply a sense current to the MR head using a rotary transformer, a circuit board is provided on the rotating drum side, and the alternating current transmitted via the rotary transformer is converted to direct current on the circuit board. Then, it is necessary to form a power supply circuit for supplying a sense current to the MR head.

Further, in order to improve the frequency characteristics of the reproducing system and reduce noise, the readout is performed by a magnetoresistive magnetic head element on a circuit board provided on the rotating drum side. It is desirable to also form a reproduction circuit for amplifying the reproduction signal. In this case, the reproducing circuit is supplied with a constant voltage from the power supply circuit.

[0012]

As described above, when a circuit board on which a power supply circuit and a reproduction circuit are formed is mounted on the rotary drum side, there is a problem that noise is easily transmitted to the circuit board.

That is, since the rotating drum is generally formed of a metal material in a substantially cylindrical shape and has a large surface area, the rotating drum sometimes acts as an antenna for picking up electric or electromagnetic noise in the space. The noise may propagate to a circuit board attached to the rotating drum.

When such noise propagates to the circuit board, the normal operation of the power supply circuit and the reproduction circuit is hindered, and
In some cases, the head cannot read the signal properly.

Accordingly, the present invention effectively suppresses the propagation of noise to a circuit board mounted on the rotating drum side,
It is an object of the present invention to provide a magnetic head device capable of appropriately reading a signal.

[0016]

According to the present invention, there is provided a magnetic head device comprising: a fixed drum; a rotating drum made of a conductive material rotatably provided with respect to the fixed drum; and a magnetic drum attached to the rotating drum. A magnetic head element of a resistance effect type, a rotary transformer for transmitting a signal between the fixed drum and the rotating drum in a non-contact manner, and amplifying a reproduction signal read by the magnetic head element of the magnetoresistance effect type And a power supply circuit for supplying a constant voltage to the reproduction circuit and / or supplying a sense current to the magnetoresistive effect type magnetic head element. A circuit board disposed in a space formed between the drum and the rotor of the rotary transformer, wherein the circuit board is formed with the reproduction circuit and the power supply circuit. A layer that is made of a plurality of layers including an entire surface ground pattern is formed layer, the ground pattern is characterized by being electrically connected to the rotary drum.

In this magnetic head device, the rotary drum is provided rotatably with respect to the fixed drum. A magnetic head element of a magnetoresistive effect type is attached to the rotating drum. The magnetic head element of the magnetoresistive effect slides on a magnetic tape running along the outer peripheral surface of the fixed drum and the rotating drum when the rotating drum is rotated, and transmits a signal recorded on the magnetic tape. read out.

A rotary transformer for transmitting signals between the fixed drum and the rotary drum is provided. The signal read from the magnetic tape by the magnetoresistive head element mounted on the rotating drum is transmitted to the fixed drum via this rotary transformer. The rotary transformer transmits, for example, a drive current for driving a magnetoresistive head element from the fixed drum side to the rotary drum side.

In a space formed between the rotary drum and the rotor of the rotary transformer, a reproducing circuit for amplifying a reproducing signal read out by a magnetoresistive magnetic head element, and a reproducing circuit for this reproducing circuit. In addition to supplying a constant voltage, the AC drive current transmitted from the fixed drum side to the rotary drum side via the rotary transformer is converted into DC, and supplied as a sense current to the magnetoresistive effect type magnetic head element. A circuit board on which a power supply circuit and the like are formed is provided. The circuit board has a multilayer structure including a plurality of layers including a layer on which a reproduction circuit, a power supply circuit, and the like are formed, and a layer on which a ground pattern is formed on the entire surface.
The ground pattern of the circuit board is electrically connected to a rotating drum made of a conductive material.

In the magnetic head device according to the present invention,
As described above, the circuit board is shielded by the electrical connection between the ground pattern formed on the entire surface of one layer of the circuit board and the rotating drum made of a conductive material. Signals can be appropriately read by the magnetoresistive head while avoiding the inconvenience of magnetic or electromagnetic noise propagating to the circuit board.

In this magnetic head device, it is desirable that a coil and a magnet of a drive motor for rotatingly driving the rotary drum are housed in a motor housing provided on the rotary drum.

As described above, the magnetic head device is configured such that the coil of the drive motor and the magnet are housed in the motor housing provided on the rotating drum.
The size of the entire device can be reduced.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

One example of a magnetic head device to which the present invention is applied is shown in FIGS. 1 is a perspective view of the magnetic head device 1, FIG. 2 is a plan view of the magnetic head device 1, and FIG. 3 is a sectional view taken along line A1-A2 in FIG.

The magnetic head device 1 is used in a recording / reproducing device configured to record / reproduce a signal on / from a magnetic tape T by a helical scan method. The magnetic head element is slid on the recording surface of the magnetic tape T traveling along a predetermined path, a signal is written on the magnetic tape T, and a magnetic signal is written on the recording surface of the magnetic tape T on which the signal is written. The head element is slid, and the signal written on the magnetic tape T is read.

As shown in FIGS. 1 to 3, the magnetic head device 1 includes a fixed drum 2 fixedly provided in a recording / reproducing device, and a rotating drum 3 provided coaxially with the fixed drum 2. A drive motor 4 for driving the rotary drum 3 to rotate, and a rotary transformer 5 for transmitting signals between the fixed drum 2 and the rotary drum 3.

The fixed drum 2 is formed by molding a metal material such as aluminum into a substantially cylindrical shape, and has a center hole 6 in the center of which a shaft 14 of the drive motor 4 is inserted. Further, on the outer peripheral surface of the fixed drum 2, an apparatus main body 5 is provided.
The tape guide groove 7 is provided for guiding the winding of the magnetic tape T around the outer peripheral surface of the magnetic tape T and maintaining the posture. The tape guide groove 7 is formed to be inclined at a predetermined angle with respect to a direction perpendicular to the center axis of the fixed drum 2. The magnetic tape T is obliquely wound around the outer peripheral surfaces of the fixed drum 2 and the rotating drum 3 with the lower end supported by the tape guide groove 7 provided on the outer peripheral surface of the fixed drum 2.

As shown in FIG. 3, the rotary drum 3 includes a drum portion 3a formed of a metal material such as aluminum in a substantially cylindrical shape, similarly to the fixed drum 2, and a shaft portion 1 of a drive motor 4.
4 and a flange portion 3b constituting a housing of the bearing 8 is joined and integrated. The flange portion 3b of the rotary drum 3 is made of a metal material such as aluminum similarly to the drum portion 3a, and has a center hole 9 at the center portion through which a shaft portion 14 of the drive motor 4 is inserted via a bearing 8. ing. Further, a drum supporting portion 19 for supporting a lower end portion of the drum portion 3a is provided on an outer peripheral side of the flange portion 3b so as to protrude outward. The flange portion 3b of the rotating drum 3 is connected to the drum portion 3a by the drum support portion 19.
Is joined and integrated with the drum part 3a while supporting the lower end of the drum part 3a.

On the upper end side of the drum portion 3a of the rotary drum 3, a motor accommodating portion 10 for accommodating the main body 13 of the drive motor 4 is provided. Further, the lower end of the drum portion 3a of the rotary drum 3 is provided with a drum support portion 1 of a flange portion 3b.
9 through the head support plate 20 on the outer peripheral side not in contact with
Recording magnetic head element 21 and reproducing magnetic head element 2
2 are installed. The tip of each of the recording magnetic head element 21 and the reproducing magnetic head element 22 is
The rotating drum 3 is attached to the lower end of the drum portion 3a so as to face outward through a window portion 12 provided so as to open on the outer peripheral surface.

The drive motor 4 includes a motor body 13 and a shaft 14. The motor body 13 is housed in a motor housing 10 provided at the upper end of the drum 3 a of the rotary drum 3. Are inserted through the center hole 9 of the flange portion 3 b of the rotating drum 3 and the center hole 6 of the fixed drum 2. Thereby, the fixed drum 2 and the rotating drum 3
The drive motor 4 is connected via a shaft 14. Here, the shaft portion 14 of the drive motor 4 is tightly fitted into the center hole 6 of the fixed drum 2 and is fixed to the fixed drum 2. On the other hand, the shaft portion 14 of the drive motor 4
Is loosely inserted into the center hole 9 of the flange portion 3b of the rotary drum 3 via the bearing 8. For this reason, the rotating drum 3 is provided with the shaft 1 of the drive motor 4.
It is possible to rotate around 4 as a rotation center.

The motor body 13 of the drive motor 4 has a coil 15 and a magnet 16, and the coil 15 is
4, and a magnet 16 is attached to the rotating drum 3 side. Here, since the shaft portion 14 integrated with the coil 15 is fixed to the fixed drum 2, when driving power is supplied to the motor main body portion 13, the rotating drum 3 to which the magnet 16 is attached is driven. The electromagnetic operation of the motor 4 causes the shaft portion 14 to be rotated about the rotation center.

In the magnetic head device 1 of this embodiment, as described above, the motor body 13 is housed in the motor housing 10 provided on the upper end side of the drum 3a of the rotary drum 3, and the shaft 14 rotates. The rotary drum 3, which is inserted through the center hole 9 of the flange 3 b of the drum 3 and the center hole 6 of the fixed drum 2 and has the magnet 16 attached thereto, rotates the shaft 14 by the electromagnetic induction of the drive motor 4. The rotation of the apparatus around the center reduces the size of the entire apparatus.

The rotary transformer 5 includes a recording magnetic head element 2 mounted on the drum portion 3a of the rotary drum 3.
1 for transmitting a signal between the reproducing magnetic head element 22 and the fixed drum 2 side, and includes a rotor 17 and a stator 18 which are arranged to face each other with a small interval. The rotor 17 is provided with a flange portion 3b of the rotating drum 3.
, A plurality of ring-shaped coils are provided concentrically on the surface facing the stator 18. The stator 18 is provided at the upper end of the fixed drum 2, and a plurality of ring-shaped coils are provided concentrically on a surface facing the rotor 17. The rotary transformer 5 configured as described above transmits signals between the rotor 17 and the stator 18 in a non-contact manner by electromagnetic induction. The magnetic head device 1 is configured such that the recording magnetic head element 21 and the reproducing magnetic head element 22 attached to the drum portion 3 a of the rotary drum 3 are electrically connected to the rotor 17 of the rotary transformer 5 so that the recording magnetic head is A signal to be written on the magnetic tape T by the element 21 is transmitted from the fixed drum 2 side to the recording magnetic head element 21 via the rotary transformer 5 or read from the magnetic tape T by the reproducing magnetic head element 22. The signal is sent to the fixed drum 2 via the rotary transformer 5.
It is transmitted to the side.

In the magnetic head device 1 of this embodiment, FIG.
As shown in FIG. 3, two magnetic head elements 21 for recording and two magnetic head elements 22 for reproduction are provided.
The two recording magnetic head elements 21 are attached to the lower end of the drum portion 3a so as to face outward from positions 180 degrees apart from each other on the circumference of the rotating drum 3, and
Two reproducing magnetic head elements 22 are attached to the lower end of the drum portion 3a so as to face outward from positions 180 degrees apart from each other on the circumference of the rotary drum 3. Thereby, in the magnetic head device 1 of the present embodiment, the magnetic tape T
When one is wound at a winding angle of 180 degrees, one recording magnetic head element 21 and one reproducing magnetic head element 22 always come into contact with the magnetic tape T.

The magnetic head device 1 configured as described above
Are provided in a helical scan type recording / reproducing apparatus. As shown in FIG. 1 and FIG. 2, the outer peripheral surfaces of the fixed drum 2 and the rotating drum 3 of the magnetic head device 1 are guided by a tape traveling system and travel along a predetermined path in the recording / reproducing apparatus. The tape T is wound at a winding angle of, for example, 180 degrees. At this time, the magnetic tape T
By being wound along the tape guide groove 7 formed on the peripheral surface of the fixed drum 2, it is obliquely wound around the outer peripheral surface of the apparatus main body 5.

In the magnetic head device 1, the rotating drum 3 is rotated while the magnetic tape T is wound around the outer peripheral surfaces of the fixed drum 2 and the rotating drum 3. The recording magnetic head element 21 attached to the rotary drum 3 such that the tip faces outward with the rotation of the rotary drum 3.
Then, the reproducing magnetic head element 22 moves along the outer peripheral surface of the rotating drum 3 and slides obliquely on the recording surface of the magnetic tape T wound around the outer peripheral surfaces of the fixed drum 2 and the rotating drum 3. As a result, a signal is written on the signal recording surface of the magnetic tape T, and a signal is read from the recording surface of the magnetic tape T on which the signal is written.

In the magnetic head device 1 of this embodiment, an inductive type magnetic head element is used as the recording magnetic head element 21, and a magnetic head element 22 using the magnetoresistive effect is used as the reproducing magnetic head element 22. Tape T
A magnetic head element of a magnetoresistive effect type (hereinafter, referred to as an MR head 22) for reading a magnetic signal recorded in the magnetic head is used.

In the MR head 22, for example, a magnetoresistive effect element (hereinafter, referred to as an MR element) exhibiting a magnetoresistive effect is sandwiched between a pair of soft magnetic ferrite substrates via a gap formed of an insulating film. This is configured as a so-called substrate shield type MR head. This M
When the R head 22 slides on the magnetic tape T wound around the outer peripheral surface of the rotating drum 3 with the rotation of the rotating drum 3, the MR element causes the magnetic field of the magnetic tape T corresponding to the recording signal to change. The resistance value is changed according to. MR
The head 22 supplies a sense current to this MR element,
By detecting the change in resistance, a magnetic signal recorded on the magnetic tape T is read.

The MR head 22 is characterized in that a higher reproduction output can be obtained as compared with an inductive magnetic head element conventionally used as a reproducing magnetic head element in a helical scan recording / reproducing apparatus. I have. Therefore, the recording / reproducing apparatus 1 can improve the recording / reproducing characteristics while supporting high-density recording by applying the MR head 22 as the reproducing magnetic head element.

In the magnetic recording / reproducing apparatus according to the present invention, the kind of the MR head used as the magnetic head element 22 is not limited to the substrate shield type MR head exemplified here. M
Any type of MR head such as an R head and a non-shield type MR head can be applied. Further, a GMR head exhibiting a giant magnetoresistance effect, such as a spin valve type MR head utilizing a spin valve effect or an MR head utilizing a ferromagnetic tunnel effect, may be used.

When the MR head 22 is used as the reproducing magnetic head element, the magnetic tape T
In order to read the signal recorded in the MR head 22, it is necessary to supply a sense current to the MR element of the MR head 22. Therefore, in the magnetic head device 1, a sense current is supplied to the MR element of the MR head 22 using the rotary transformer 5 that transmits a signal between the rotating drum 3 and the fixed drum 2. I have. Magnetic head device 1
As described above, if the supply of the sense current to the MR element of the MR head 22 is performed using the rotary transformer 5, there is no need to add a new configuration for supplying the sense current. The recording / reproducing characteristics can be improved while simplifying the configuration and reducing the size of the entire apparatus.

Here, since the rotary transformer 5 transmits only the alternating current, in order to supply the sense current, which is a constant current, to the MR element of the MR head 22, the alternating current transmitted through the rotary transformer 5 is converted into a direct current. After converting to
It is necessary to supply to the R head 22. Therefore, in the magnetic head device 1, a circuit board 30 on which a power supply circuit for converting an AC driving current transmitted via the rotary transformer 5 to a DC and supplying the DC driving current as a sense current to the MR head 22 is formed. The configuration is provided on the rotating drum 3 side.

In order to improve the frequency characteristics of the reproducing system and reduce noise, a reproducing operation for amplifying a reproducing signal read from the magnetic tape T by the MR head 22 on the rotating drum 3 side. It is desirable that a circuit be provided. Therefore, in the magnetic head device 1, on the circuit board 30 provided on the rotating drum 3 side,
A reproduction circuit is also formed. In this case, the reproducing circuit is supplied with a constant voltage from the power supply circuit.

The circuit board 30 provided on the rotating drum 3 side
As shown in FIG. 4 (a), an annular shape having an outer diameter substantially equal to the rotor 17 of the rotary transformer 5 and an inner diameter substantially equal to the outer diameter of the drum supporting portion 19 of the flange portion 3 b of the rotary drum 3. It is molded. And this circuit board 3
Reference numeral 0 denotes an outer peripheral side of the drum supporting portion 19, which is disposed in a space formed between the rotor 17 of the rotary transformer 5 and the drum portion 3 a of the rotary drum 3 and supported by the head supporting plate 20. Recording magnetic head element 21 and reproducing magnetic head element 2 attached to the lower end of the drum section 3a
2 and the rotor 1 of the rotary transformer 5
7 is attached.

The circuit board 30 is, for example, as shown in FIG.
As shown in FIG. 5, the substrate is configured as a four-layer substrate having four pattern layers. Then, the circuit board 30
The first layer located on the rotor 17 side of the rotary transformer 5 is a ground pattern layer 31 having a ground pattern formed on the entire surface.
And a second layer adjacent via an insulator is a + power pattern layer 32 having a + power pattern formed on the entire surface, and a third layer adjacent to the + power pattern layer 32 via an insulator. The third layer and the fourth layer, which is the uppermost layer adjacent via an insulator, are used as a circuit pattern layer 33. A power supply circuit, a reproduction circuit, and the like are formed on the circuit pattern layer 33. The MR head 22 is electrically connected to a power supply circuit, a reproduction circuit, and the like formed on the circuit pattern layer 33 via a head connection terminal 39.

Circuit board 3 constituting circuit pattern layer 33
As shown in FIG. 5, a ground connection region 34 for connecting the power supply circuit and the reproduction circuit to the ground is formed in the fourth layer, which is the uppermost layer of 0. A through-hole 35 is formed in a place where the ground connection region 34 is formed so as to penetrate in the thickness direction of the circuit board 30. The ground connection region 34 is electrically connected to the ground pattern layer 31 via a conductor pattern 36 formed on the inner peripheral surface of the through hole 35.

Further, in this magnetic head device 1,
The ground connection region 34 is formed by a drum portion 3a or a flange portion 3b of the rotary drum 3 made of a conductive material via a conductive member.
The circuit pattern layer 33 of the circuit board 30 is shielded by the ground pattern layer 33 and the rotating drum 3.

As described above, since the rotating drum 3 is formed of a metal material such as aluminum into a substantially cylindrical shape and has a large surface area, the rotating drum 3 may function as an antenna for picking up electric or electromagnetic noise in a space. When a circuit board 30 on which the power supply circuit, the reproduction circuit, and the like are formed is disposed near the rotary drum 3, noise picked up by the rotary drum 3 propagates to the circuit board 30, and the power supply circuit and the reproduction circuit Etc. may be adversely affected.

Therefore, in the magnetic head device 1 according to the present invention, the ground connection region 34 electrically connected to the ground pattern layer 33 of the circuit board 30 and the drum 3a or the flange 3b of the rotary drum 3 By electrically connecting via a connecting means made of a conductive material, the circuit pattern layer 33 of the circuit board 30 on which the power supply circuit, the reproduction circuit, and the like are formed is shielded by the ground pattern layer 33 and the rotating drum 3, Electrical or electromagnetic noise picked up by the rotating drum 3 is prevented from propagating to the circuit pattern layer 33 of the circuit board 30.

Here, the ground connection area 34 formed on the uppermost layer of the circuit board 30 and the drum portion 3a of the rotating drum 3
Alternatively, a specific example in which the flange portion 3b is electrically connected will be described below.

First, as an example of electrically connecting the ground connection area 34 and the flange portion 3b of the rotary drum 3, as shown in FIGS. 6A and 6B, these are electrically connected. The conductive spring member 4
An example using 0 is given. The conductive spring member 40 is formed by forming a conductive material such as a metal into a plate shape or a linear shape, and cutting it into a predetermined length. Then, the conductive spring member 40
Is formed by bonding one end in the length direction to a ground connection region 34 formed on the uppermost layer of the circuit board 30 with solder 37 or the like, and a portion extending from a middle portion in the length direction to the other end side. By being urged toward the flange portion 3b side of the rotary drum 3 with a predetermined urging force, a part thereof comes into contact with the outer peripheral surface of the drum support portion 19 of the flange portion 3b with a predetermined contact pressure. .

As described above, one end of the conductive spring member 40 in the longitudinal direction is soldered to the ground connection region 34, and one end of the conductive spring member 40 extending from a middle portion in the longitudinal direction to the other end side. The portion contacts the outer peripheral surface of the drum support portion 19 of the flange portion 3b with a predetermined contact pressure, so that the ground connection region 34 and the flange portion 3b of the rotary drum 3 are reliably connected.

As an example of electrically connecting the ground connection area 34 to the flange 3b of the rotary drum 3, as shown in FIGS. 7A and 7B, these are electrically connected. As an example of the connecting means, there is an example in which a paste-like conductive material 41 such as a silver paste is used. When the ground connection region 34 is formed on the inner peripheral side of the uppermost layer of the circuit board 30 and the drum support portion 19 of the flange portion 3b is adjacent to the ground connection region 34, the flange portion By filling the paste-like conductive material 41 over the outer peripheral surface of the drum support portion 3b, the ground connection region 34 and the rotating drum 3 are filled.
Electrical connection with the flange portion 3b can be made very easily.

Next, as an example of electrically connecting the ground connection region 34 to the drum portion 3a of the rotating drum 3,
As shown in FIG. 8, there is an example in which a conductive spring member 42 formed in a substantially U-shape is used as a connecting means for electrically connecting them. The conductive spring member 42 is formed by forming a conductive material such as a metal into a plate shape or a linear shape, cutting it into a predetermined length, and then bending it into a substantially U-shape. The portions can be elastically displaced in the direction in which they approach and separate. One end of the substantially U-shaped conductive spring member 42 is bonded to a ground connection region 34 formed on the uppermost layer of the circuit board 30 by solder 37 or the like, and the other end is rotated. The lower end of the drum portion 3a of the drum 3 is brought into contact with a predetermined contact pressure.

As described above, one end of the substantially U-shaped conductive spring member 42 is soldered to the ground connection region 34, and the other end thereof contacts the lower end of the drum 3a in a predetermined manner. By contacting with pressure, the ground connection area 34
And the drum portion 3a of the rotary drum 3 are securely connected.

The substantially U-shaped conductive spring member 42
Can be elastically displaced in a direction in which one end and the other end are close to or separated from each other. Even if there is a slight change in the distance of
The ground connection region 34 and the drum portion 3a of the rotating drum 3 can be reliably connected.

As an example of electrically connecting the ground connection area 34 to the drum portion 3a of the rotating drum 3,
As shown in FIG. 9, there is an example in which a contact pin 43 is used as a connecting means for electrically connecting them. The contact pins 43 are provided in a movable pin 44 made of a conductive material such as a metal, a pin housing member 45 made of a conductive material such as a metal and housing the base end side of the movable pin 44, and in the pin housing member 45. And a coil spring 46 that movably supports the proximal end of the movable pin 44. The contact pins 43 are connected to the ground connection area 34 where the pin housing members 45 are formed on the uppermost layer of the circuit board 30.
And the tip of the movable pin 44 is brought into contact with the lower end of the drum portion 3a of the rotating drum 3 at a predetermined contact pressure.

As described above, the contact pins 43 are such that the pin housing members 45 are soldered to the ground connection areas 34, and the distal ends of the movable pins 44 contact the lower ends of the drum portions 3a with a predetermined contact pressure. Thereby, the ground connection region 34 and the drum portion 3a of the rotating drum 3 are securely connected.

The contact pin 43 has the base end of the movable pin 44 supported by the coil spring 46, and the movable pin 44 is movable with respect to the pin housing member 45. As in the case where the conductive spring member 42 is used, even when the distance between the drum portion 3a of the rotary drum 3 and the circuit board 30 slightly changes due to, for example, an error in the mounting of the rotary drum 3, the ground may be provided. The connection region 34 and the drum portion 3a of the rotary drum 3 can be reliably connected.

As an example of electrically connecting the ground connection area 34 and the drum portion 3a of the rotating drum 3,
As shown in FIG. 10, there is an example in which an anisotropic conductive contact terminal 47 is used as a connecting means for electrically connecting them. The anisotropic conductive contact terminal 47 is formed by embedding a wire made of a conductive material such as a metal in an elastic insulating material formed into, for example, a rectangular parallelepiped. One end of the anisotropic conductive contact terminal 47 is connected to the circuit board 30.
A predetermined contact pressure, and the other end thereof contacts a lower end of the drum portion 3a of the rotary drum 3 at a predetermined contact pressure. .

As described above, one end of the anisotropic conductive contact terminal 47 is brought into contact with the ground connection region 34 formed on the uppermost layer of the circuit board 30 with a predetermined contact pressure, and the other end is contacted. When the end portion contacts the lower end portion of the drum portion 3a of the rotary drum 3 with a predetermined contact pressure, the ground connection region 3
4 and the drum portion 3a of the rotary drum 3 are securely connected.

The anisotropic conductive contact terminal 47 has a structure in which a wire is embedded in an elastic insulating material and is capable of elastic displacement, so that the above-described U-shaped conductive spring is provided. Similarly to the case where the member 42 and the contact pin 43 are used, even when the distance between the drum portion 3 a of the rotary drum 3 and the circuit board 30 slightly changes due to, for example, an attachment error of the rotary drum 3, The ground connection region 34 and the drum portion 3a of the rotating drum 3 can be reliably connected. The anisotropic conductive contact terminal 47
If a shape is formed such that the area of one end contacting the ground connection region 34 is increased, the plurality of ground connection regions 34 can be simultaneously connected to the drum portion 3 a of the rotating drum 3.

In the magnetic head device 1 according to the present invention, the ground connection region 34 electrically connected to the ground pattern layer 33 of the circuit board 30 and the drum portion 3a or the flange The circuit pattern layer 33 on which the power supply circuit and the reproduction circuit of the circuit board 30 are formed is shielded by the ground pattern layer 33 and the rotating drum 3 by electrically connecting the unit 3b to the unit 3b. Can be prevented from propagating to the circuit pattern layer 33 of the circuit board 30, and good recording / reproducing characteristics can be exhibited.

In particular, in the magnetic head device 1 described above, the motor main body 13 is accommodated in the motor accommodating portion 10 provided on the rotating drum 3 so as to be miniaturized. Is difficult to dispose on the rotating drum 3. Therefore, in this case, the circuit board 30 is provided in a space formed between the rotary drum 3 and the rotor 17 of the rotary transformer 5 while being supported by the rotor 17.

When the circuit board 30 is disposed on the rotating drum 3, the circuit board 30 is fixed to the rotating drum 3 using a screw member made of a conductive material.
The electrical connection between the ground pattern layer 33 and the rotary drum 3 can be easily established, but the circuit board 30 is placed in a space formed between the rotary drum 3 and the rotor 17 of the rotary transformer 5. When the circuit board 30 is provided while being supported by the rotor 17, the electrical connection between the ground pattern layer 33 of the circuit board 30 and the rotating drum 3 is performed in the same manner as when the circuit board 30 is provided on the rotating drum 3. Can not be planned.

However, as described above, the magnetic head device 1 according to the present invention comprises the conductive spring member 40, the paste-like conductive material 41, the U-shaped conductive spring member 42, the contact pin 43, The ground connection area 34 electrically connected to the ground pattern layer 33 of the circuit board 30 and the rotary drum 3 drum portion 3a or the flange portion 3b are electrically connected using connection means such as the conductive contact terminals 47. Thus, the ground pattern layer 3 of the circuit board 30
The electrical connection between the rotary drum 3 and the rotary drum 3 can be reliably and easily made.

[0067]

In the magnetic head device according to the present invention, since the ground pattern of the circuit board is electrically connected to the rotating drum, the layer on which the power supply circuit, the reproduction circuit, and the like of the circuit board are formed is replaced with the circuit board. The ground pattern is shielded by a layer formed on the entire surface and the rotating drum, thereby effectively preventing electric or electromagnetic noise from propagating to the layer of the circuit board on which the power supply circuit, the reproduction circuit, and the like are formed. Signal reading by the resistance effect type magnetic head can be appropriately performed.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an example of a magnetic head device according to the present invention.

FIG. 2 is a plan view of the magnetic head device.

3 is a longitudinal sectional view of the magnetic head device, and is a sectional view taken along line A1-A2 in FIG. 2;

4A and 4B are diagrams illustrating a circuit board included in the magnetic head device, wherein FIG. 4A is a plan view of the circuit board, and FIG.
Is a side view of the circuit board.

FIG. 5 is a sectional view of a main part of the circuit board.

6A and 6B are diagrams illustrating an example of a method of electrically connecting a ground connection region of the circuit board and a flange portion of a rotating drum, and FIG. 6A schematically illustrates a case where a conductive spring member is used. It is a top view, (b) is a longitudinal section showing typically the case where a conductive spring member is used.

7A and 7B are diagrams showing another example of a method of electrically connecting the ground connection region of the circuit board and the flange portion of the rotating drum, and FIG. 7A schematically illustrates a case where a paste-like conductive material is used. FIG. 4B is a plan view schematically showing a case in which a paste-like conductive material is used, and FIG.

FIG. 8 is a diagram illustrating an example of a method of electrically connecting a ground connection region of the circuit board and a drum portion of a rotating drum, and is a schematic diagram illustrating a case where a U-shaped conductive spring member is used. .

FIG. 9 is a diagram showing another example of a method of electrically connecting the ground connection region of the circuit board and the drum portion of the rotating drum, and is a schematic diagram in a case where contact pins are used.

FIG. 10 is a view showing still another example of a method of electrically connecting the ground connection area of the circuit board and the drum section of the rotary drum, and is a schematic view showing a case where an anisotropic conductive contact terminal is used. It is.

[Description of Signs] 1 magnetic head device, 2 fixed drum, 3 rotating drum, 3a drum portion, 3b flange portion, 4 drive motor, 5 rotary transformer, 17 rotor, 18 stator, 22 MR head, 30 circuit board, 31 ground Pattern layer, 33 circuit pattern layer, 34 ground connection region, 40 conductive spring member, 41 paste-like conductive material, 42 U-shaped conductive spring member, 43
Contact pin, 47 Anisotropic conductive contact terminal

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tomohiro Ikegami 6-35, Kita-Shinagawa, Shinagawa-ku, Tokyo Sony Corporation F-term (reference) 5D036 AA02 CC29 5D091 AA04 DD09 EE09 EE26 HH08

Claims (6)

[Claims] A fixed drum; a rotating drum made of a conductive material rotatably provided with respect to the fixed drum; a magnetoresistive effect type magnetic head element mounted on the rotating drum; A rotary transformer for transmitting a signal to and from a rotary drum in a non-contact manner; and a reproducing circuit for amplifying a reproducing signal read by the magnetoresistive effect type magnetic head element. A power supply circuit for supplying a constant voltage to the circuit and / or supplying a sense current to the magnetoresistive magnetic head element is formed, and is formed between the rotary drum and the rotor of the rotary transformer. A circuit board disposed in a space in which the reproduction circuit and the power supply circuit are formed, and a ground pattern is formed on the entire surface of the circuit board. It was made from a plurality of layers including a layer, the magnetic head device in which the ground pattern is characterized by being electrically connected to the rotary drum. 2. The magnetic head device according to claim 1, wherein a coil and a magnet of a drive motor for rotating the rotating drum are housed in a motor housing provided on the rotating drum. 3. The magnetic head device according to claim 1, wherein the ground pattern of the circuit board and the rotary drum are electrically connected via a conductive spring member. 4. The magnetic head device according to claim 1, wherein the ground pattern of the circuit board and the rotating drum are electrically connected via a paste-like conductive material. 5. The magnetic head device according to claim 1, wherein the ground pattern of the circuit board and the rotary drum are electrically connected via contact pins. 6. The magnetic head device according to claim 1, wherein the ground pattern of the circuit board and the rotating drum are electrically connected via an anisotropic conductive contact terminal.