JPH10275317A - Rotating head device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high reproducing output of a high frequency by the device used in a magnetic recording system. SOLUTION: A rotary part including a magnetic head chip 1 on an outer circumferential part is driven to rotate by a motor. Electric power for this power source is transmitted from a fixed part via a rotary transformer to the rotary part, and also a regenerative signal voltage amplifier circuit (IC) 3 is fixedly connected onto base members 7 and 26a where the magnetic head chip 1 and its lead wires 25 are fixed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention belongs to the technical field of a rotary head device used in a video tape recorder or a data cartridge drive device for a computer.

[0002]

2. Description of the Related Art In recent years, in a data cartridge drive or the like used for an external storage device for a computer or the like, a channel clock frequency of several tens MHz (megahertz) to several hundreds MHz is increased due to an increase in a transfer speed of an information signal. It has risen greatly. Therefore, in a magnetic head device, the input capacitance of a voltage amplifier (reproducing amplifier), the output capacitance of a current amplifier (recording amplifier), or the electrostatic stray capacitance between wiring between a magnetic head chip and these amplifiers. Reducing the reproduction output of a high-frequency signal due to resonance with the inductance of the magnetic head chip (LC resonance) has become a major problem.

In order to reduce the deterioration of reproduction output of a high-frequency signal due to such LC resonance, the capacitance of a signal amplifier, the electrostatic stray capacitance between wiring between a magnetic head chip and an amplifier, and the inductance of a magnetic head are reduced. At least one
It is known that reducing the number is effective.

In particular, in a recording / reproducing system using a rotary head device, there is usually a rotary transformer for transmitting a recording / reproducing signal between the magnetic head chip and its signal amplifier. The wiring distance between them ranges from several tens of millimeters (mm). Therefore, in such a recording / reproducing system, it is difficult to reduce the electrostatic stray capacitance between the wirings, and the signal-to-noise ratio of the reproduced signal (S
/ N ratio) is degraded.

A signal reproducing portion of a recording / reproducing system in which a rotary transformer (rotary transformer) exists between a magnetic head chip and a signal amplifier (voltage amplifier) generally used in the prior art is shown in FIG. The signal reproduced from the reproducing magnetic head chip 101 is supplied to the signal amplifier 103 via the rotary transformer 102. The signal amplifier 103 is supplied with power from a DC power supply 104. Then, the signal amplifier 103 outputs the amplified reproduction voltage from the reproduction output terminals 105a and 105b.

As a configuration of a rotary head device capable of reducing electrostatic stray capacitance between wires between a magnetic head chip and a signal amplifier, a rotary head device described in Japanese Patent Application Laid-Open No. 60-5406 is disclosed. The signal amplifier is provided on the rotating side, and the power for the signal amplifier is transmitted from the fixed side to the rotating side via a rotating transformer. In this rotary head device, the wiring distance between the magnetic head chip and the signal amplifier is shortened, the electrostatic stray capacitance between the wirings is reduced, and the quality deterioration at the time of transmitting the reproduction signal by the rotating transformer having a gap is reduced. Is prevented.

In such a rotary head device, as shown in FIG. 8, the magnetic head chip is attached to a tip portion 107a of a base plate 107b fixed on a rotating portion. The base plate 107b has a screw hole 109, and is fixed on a rotating part of the rotary head device by a screw inserted into the screw hole 109. Magnetic head chip 1
Numeral 01 is bonded to the tip of the tip portion 107a of the base plate 107b with an adhesive. The magnetic head chip 101 is patterned on a terminal board 108 disposed on the base plate 107b via lead wires 106, 106 of a head winding adhered on the base plate 107b with an adhesive. It is soldered to the connection terminals 111 and 112. Necessary wiring and reproduction output terminals 110a and 110b are patterned on the terminal board 108. These reproduction output terminals 110a and 110b are connected to connection terminals 111 and 112 via wiring.

Normally, contact pins or lead wires are connected to the reproduction output terminals 110a and 110b, and are connected to input terminals of a signal amplifier via these contact pins and lead wires.

The base plate 107a shown in FIG. 8 is viewed from the upper surface side having a large area.
cm ^{2 to} 2 cm ² , and the thickness seen from the side is usually 1 m
m. The base plate 107a is formed of a material such as brass. In addition, the components in the state shown in FIG. 8, that is, the magnetic head chip 101, the base plate 107a, and the terminal board 108 are usually one "magnetic head component".
Will be shipped as The “magnetic head component” having such a configuration is, for example, a digital audio tape recorder (R-DAT), a digital data storage system (DDS), an “8 mm video” (trade name) tape recorder (8 mm-VCR), a digital video It is widely used in many tape-based systems such as a tape recorder (DVC).

[0010]

By the way, in the rotary head device as described above, it is possible to reduce the electrostatic stray capacitance due to wiring compared to the rotary head device having the configuration shown in FIG. Is the magnetic head chip 10
There is still 3 between the 1 and the input terminal of the voltage amplifier.
Wiring having a length of about 0 mm to 100 mm is required.
This is because the wiring between the magnetic head chip 101 and the voltage amplifier is performed via contact pins or lead wires connected to the terminal substrate 108 as shown in FIG.

Therefore, particularly in a system using a channel clock frequency of 100 MHz or more, the reduction of the electrostatic stray capacitance due to the wiring between the magnetic head chip 101 and the voltage amplifier is insufficient.

When the power for the power supply of the signal amplifier is transmitted through the rotary transformer, the power for the power supply is very large compared to the power of the reproduction signal from the magnetic head chip 101. There is a problem that a signal is mixed from a wiring between the magnetic head chip 101 and the signal amplifier, and the quality of a reproduced signal is easily deteriorated.

Accordingly, the present invention has been proposed in view of the above-mentioned circumstances, and the electrostatic stray capacitance between a magnetic head chip and a signal amplifier has been sufficiently reduced, so that a reproduced signal has a high frequency band. An object of the present invention is to solve the problem of providing a rotary head device in which a decrease in reproduction output is prevented even in a certain case, and the quality of a reproduction signal is prevented from being deteriorated by a transmission signal for a power supply of a signal amplifier.

[0014]

In order to solve the above-mentioned problems, in a rotary head device according to the present invention, a reproduced signal voltage amplifying circuit for amplifying a reproduced signal from a magnetic head chip has a magnetic head chip mounted thereon. Fixedly connected to the base member.

Therefore, in the rotary head device according to the present invention, a high reproduction output can be obtained especially at the time of reproducing a high-frequency signal, and the mixing of noise into the reproduction signal due to the power transmission into the rotating section can be reduced. .

[0016]

Embodiments of the present invention will be described below with reference to the drawings. The rotary head device according to the present invention has a magnetic head chip on a rotatable rotatably supported rotating unit, and rotates the rotating unit by a motor to record an information signal on a magnetic tape by the magnetic head chip. And a device for performing reproduction.

In this rotary head device, as shown in FIG. 1, an AC signal generated from a current signal generator 6 installed on a fixed side is supplied to a rotary transformer (rotary transformer) 2b for power transmission for power supply. After being transmitted to the rectifier circuit 4 on the rotating side via the rectifier circuit 4, the reproduced signal is supplied to the first-stage amplifier 3 as a DC power supply. On the other hand, the reproduction signal output from the magnetic head chip 1 provided on the rotating unit is amplified by the first-stage amplifier 3 to a voltage of about 100 to 1000 times, and then is transmitted through the rotating transformer 2a for transmitting the reproduction signal. It is output from the reproduction output terminals 5a and 5b.

As shown in FIG. 2, the rotary head device has a central rotating shaft 21 for supporting a rotating portion. This center rotating shaft 21 is provided with ball bearings 14, 1
It is rotatable by being supported by the fixed drum 17 via the support 4. The fixed drum 17 has a substantially cylindrical outer peripheral surface, and is fixedly disposed on a chassis of a recording / reproducing device or the like to form a fixed portion.

The rotating drum 11 having a cylindrical outer peripheral surface is attached to the center rotating shaft 21. Further, a flange 23 is attached to the rotary drum 11 by a screw 24 for fixing the rotary drum. These rotating drums 1
The 1 and the flange 23 constitute a rotating part. Also,
The magnetic head chip 1 is attached to the rotating drum 11. The magnetic head chip 1 is fixed to a base plate 26b serving as a base member.
b is fixed to the rotating drum 11 by fixing screws 8, and thus is attached to the rotating drum 11.

On the rotating part, the reproduced signal is transmitted via a rotary transformer 2b for transmitting power supply, which comprises a rotary coil 9 attached to the rotary drum 11 and a fixed coil 15 attached to the fixed drum 17. Power supply power for the amplifier circuit is transmitted. In addition, between the rotating part and the fixed part of the rotary head device, a rotary transformer for transmitting a recording / reproducing signal, comprising a rotary coil 10 mounted on a rotary drum 11 and a fixed coil 16 mounted on a fixed drum 17. 2
A reproduction signal and a recording signal are transmitted and received via a.

The rotary head device has a motor for rotating the rotary unit. The motor comprises a rotor 12 mounted on a center rotating shaft 21 and a rotor 1
2 and a stator coil board 18 attached to the fixed drum 17 and facing the magnet 13. This motor rotates the rotor 12 by supplying a drive current to the stator coil on the stator coil substrate 18. When the rotor 12 is operated to rotate, the rotating unit is operated to rotate together with the central rotation shaft 21.

A preload spring 19 is provided between each of the ball bearings 14 so that the rotation of the rotating portion is performed smoothly. In addition, fixed drum 1
7 is provided with a fixed-side rotating board 20 for transmitting a recording / reproducing signal.

In this embodiment, the rotary transformer for transmitting power is separated from the rotary transformer for transmitting recording / reproducing signals. However, these rotary transformers are integrally formed. It may be.

In this rotary head device, the base member to which the magnetic head chip 1 is attached is composed of a base plate 26b and a base number 26b as shown in FIG.
And a terminal board 7 attached to the terminal board 7. The base plate 26b has a screw hole 36, and is fixed to the rotating drum 11 by a screw inserted into the screw hole 36. The magnetic head chip 1 is adhered to the tip of the tip side 26a of the base plate 26b with an adhesive. The magnetic head chip 1 is patterned on the terminal board 7 disposed on the base plate 26b via the lead wires 25, 25 of the head winding bonded to the base plate 26b with an adhesive. It is soldered to the connection terminals 27 and 28. On the terminal board 7, necessary wiring is patterned.
A circuit for reproducing voltage amplification (integrated circuit (I
C)) 3 is fixedly disposed. The reproduction voltage amplifying circuit 3 is connected to connection terminals 27 and 28 via a patterned wiring. On the terminal board 7, reproduction output terminals 33 and 34 are patterned. These reproduction output terminals 33 and 34 are connected to the reproduction voltage amplification circuit 3 via patterned wiring. Normally, contact pins or lead wires 35a, 35b and the like are connected to the reproduction output terminals 33, 34.

The power supply chip capacitor 4 is fixed on the terminal board 7. The power supply chip capacitor 4 is connected to the reproduction voltage amplifying circuit 3 via a patterned wiring. A power supply terminal (VCC) 31 and a grounding ground terminal (GND) 32 are patterned on the terminal board 7.
The power supply terminal 31 and the grounding ground terminal 32 are connected to the power supply chip capacitor 4 via a patterned wiring. Normally, contact pins or lead wires 29 and 30 are connected to the power supply terminal 31 and the grounding ground terminal 32. In the terminal board 7, the reproduction output terminals 33 and 34, the power supply terminal 31, and the grounding ground terminal 32 are provided on opposite sides via the screw holes 36.

The base plate 26b shown in FIG. 3 is viewed from the upper surface having a large area, and its area is usually 1c.
m ^{2 to} 2 cm ² , the thickness seen from the side is usually 1 mm
Before and after. The base plate 26b is formed of a material such as brass.

On the terminal board 7 attached to the base plate 26b, as shown in FIG. 4, only the reproduction voltage amplifying circuit 3 and necessary patterning are provided without providing the power supply chip capacitor 4. It may be.
In this case, the power supply terminal 31 and the grounding ground terminal 3
2 is connected to a reproduction voltage amplification circuit 3 via a patterned wiring.

Further, as shown in FIG. 5, instead of the power supply terminal 31 and the grounding ground terminal 32, a power supply connector 37 is provided on the terminal board 7 attached to the base plate 26b.
May be attached. Power can be easily supplied to the pattern on the terminal board 7 via the power connector 37.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS As an embodiment of a rotary head device according to the present invention, a track width of 14 .mu.
m, gap length 0.18μm, inductance 1.5μ
Using a stacked amorphous magnetic head chip of H, an IC amplifier having an input capacitance of 5 pF as a reproduction signal amplifier,
As the base member for fixing the magnetic head chip, a base member having the configuration shown in FIG. 3 was employed. Each of the IC amplifier and the power supply capacitor having a capacity of 0.1 μF was fixedly connected to the terminal board on the base plate by soldering.

On the other hand, as a comparative example, a magnetic head chip and a reproduction signal amplifier which were the same as those in the above-described embodiment were used, and a base plate having the conventional structure shown in FIG. 8 was used. The IC amplifier was fixedly connected by solder to a circuit board provided on a rotating drum.

In the experiment for measuring the reproduction output, "AIT (adva
The data cartridge drive system "SDX-300C" using a magnetic tape having a width of 8 mm, which is commercially available under the format name of "nced intelligent tape) 1", was modified and used. That is, this drive usually has a relative speed between the magnetic head chip and the tape of 10.03 m /.
sec (drum rotation speed 4800 rpm) and the channel clock frequency is 57.3 MHz (Nyquist frequency 2
8.7 MHz), but this relative speed is 13.8 m /
1 (drum rotation speed 6600 rpm) and a signal input from an external signal generator is possible. As shown in FIG. 1, the rotating drum has a rotating transformer for power transmission for power supply as a rotating drum. By changing to a drum, it was modified so that it could be used for experiments in higher frequency bands.

That is, in this embodiment and the comparative example, FIG.
, And the circuit block of the rotary transformer has the configuration shown in FIG.

However, in this embodiment, the channel clock frequency is 100 MHz (the Nyquist frequency is 50 MHz).
MHz).
Using a recording frequency in the 60 MHz range, the reproduction signal is 1 ch
(Ach).

The winding ratio of the rotary transformer used was 1: 1 for power transmission and recording / reproduction, and the power supply frequency for power transmission was 75 kHz.

The recording medium was cut into a width of 8 mm.
A single-frequency rectangular wave signal was recorded on a CoO vapor-deposited tape having a magnetic layer thin film of 200 nm, and the fundamental wave voltage of the signal output was measured using a spectrum analyzer.

The recording magnetic head has a track width of 36 μm.
m, gap length 0.25μm, inductance 1.0μ
A recording current amplifier having an output capacitance of 9 pF was used using a metal-in-gap magnetic head of H type. At this time, the magnetomotive force during recording was 1 Ap-p · turns at a frequency of 27 MHz.

As shown in FIG. 6, in the frequency characteristics of the fundamental wave reproduction output when the signals are reproduced using the rotary head devices of the embodiment and the comparative example, the reproduction signal amplifying IC is mounted on the base plate 26b (see FIG. 6). By using the rotary head device according to the present invention fixedly connected to (on the terminal substrate 7), compared with the rotary head device of the comparative example in which the reproducing amplifier is fixedly connected to another substrate, a high frequency of at least 20 MHz or more is used. It can be seen that the reproduction output is significantly improved in the frequency band. For example, at a recording frequency of 50 MHz, the reproduction output is improved by about 3 dB.

This is because, in the rotary head device according to the present invention, the distance between the magnetic head chip 1 and the reproduction signal amplifier circuit 3 is remarkably reduced. This is because the electrostatic stray capacitance between the first and third capacitors is greatly reduced.

Further, in the comparative example, the dive noise of the AC signal for power transmission was observed on the spectrum analyzer with respect to the reproduced signal, but in the example, it was hardly observed.

This is because, in the rotary head device according to the present invention, since the distance between the magnetic head chip 1 and the reproduction signal amplifying circuit 3 is remarkably shortened, external noise is mixed into the reproduction signal. This is because it has been significantly reduced.

The configuration of the base member of the rotary head device according to the present invention shown in FIG. 3 to FIG. 5 is such that in the rotary head device, the power supply for the reproduction signal amplifier circuit 3 is transferred from the fixed portion to the rotary portion. It can only be put to practical use by transmitting.

The reproduction signal amplifier circuit 3 used in the rotary head device according to the present invention is desirably a highly integrated (LSI) circuit in order to minimize the volume.

The magnetic head chip 1 used in the rotary head device according to the present invention may be any type of magnetic head chip usually used for magnetic recording and reproduction, such as a bulk type ferrite head and a thin film head. .

Further, the magnetic head chip 1 and the reproduction signal amplifier circuit 3 used in the rotary head device according to the present invention.
Is preferably 30 mm or less. The distance between the magnetic head chip 1 and the reproduction signal amplifier circuit 3 is 3
If it is 0 mm or more, there is a possibility that a reproduction signal having sufficiently good high-frequency characteristics cannot be obtained.

[0045]

As described above, in the rotary head device according to the present invention, a high reproduction output can be obtained even in a high frequency band. As a result, it becomes possible to reproduce a signal in a higher frequency band than before, and it is possible to increase the transfer speed.

That is, according to the present invention, the electrostatic stray capacitance between the magnetic head chip and the signal amplifier is sufficiently reduced,
It is possible to provide a rotary head device in which a decrease in reproduction output is prevented even when the reproduction signal is in a high frequency band, and a deterioration in the quality of the reproduction signal due to a transmission signal for a power supply of a signal amplifier is prevented. is there.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a rotary head device according to the present invention.

FIG. 2 is a longitudinal sectional view showing a configuration of the rotary head device.

FIG. 3 is a plan view conceptually showing a configuration of a base member of the rotary head device.

FIG. 4 is a plan view conceptually showing another form of the configuration of the base member.

FIG. 5 is a plan view conceptually showing still another embodiment of the configuration of the base member.

FIG. 6 is a characteristic diagram for comparing frequency characteristics of a fundamental wave reproduction output between the rotary head device according to the present invention and a comparative example.

FIG. 7 is a block diagram showing a configuration of a conventional rotary head device.

FIG. 8 is a plan view conceptually showing a configuration of a base member of a conventional rotary head device.

[Explanation of symbols]

Reference Signs List 1 magnetic head chip, 3 reproduction voltage amplifier circuit, 4 power supply capacitor, 7 terminal board, 25 lead wires, 26a
Base plate, 27, 28 connection terminal,

Claims (3)

[Claims] A rotating portion rotatably supported; a magnetic head chip mounted on an outer peripheral portion of the rotating portion via a base member; and a reproduction signal voltage amplifier circuit fixedly connected to the base member. A rotary head device, comprising: a rotary transformer that transmits power supply power supplied from a fixed unit side to the reproduction signal voltage amplifier circuit; and a motor that rotates the rotary unit. 2. The rotary head device according to claim 1, wherein the power input terminal is provided on the base member, and a lead wire of the magnetic head chip is fixed on the base member. 3. The rotary head device according to claim 2, wherein the power supply capacitor is fixedly connected to the base member.