JPH09180102A - Rotary magnet head drum device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a magnetic drum device allowing a video tape recorder to have both of multi-channels and high picture quality compatibly and also permitting easy replacing of parts. SOLUTION: A signal amplifier 121 is arranged adjacently to a magnetic head 120 in the same space as the magnetic head 120. Therefore, a path for a microscopic signal which easily picks up noise is shortened. Also, a rotor 109b of a coaxial rotary trans 109 and slip rings 105 are fixed to common fixing member 110 with a shaft hole, and the fixing member 110 is coupled with the rotary drum 101 and the shaft hole of the fixing member 110 is fitted to a rotary shaft 103 of the rotary drum 101. The rotary shaft 103 is precisely finished, and a high precision fitting of the fixing member to the rotary shaft 103 improves the assembling accuracy of a B-axis rotary trans 109 and enables to suppress cross-talk and makes part replacing easier.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a head drum device such as a video tape recorder.

[0002]

2. Description of the Related Art A rotary magnetic head drum device such as a VTR which has been conventionally used has a structure shown in FIG. That is, reference numeral 201 in FIG.
Reference numeral denotes a rotary drum, 202 is a fixed drum, 203 is a shaft, 205 is a slip ring, 207 is a brush, 208 is a flat plate rotary transformer, 208a is a flat plate rotary transformer stator, 208b is a flat plate rotary transformer rotor, and 209 is Coaxial rotary transformer,
209a is a coaxial rotary transformer stator, 209b
Is a coaxial rotary transformer rotor, 220 is a magnetic head, and 221 is a signal amplifier circuit.

In the magnetic head drum device, a magnetic head 220 for reproducing a signal from the magnetic tape or conversely recording a signal on the magnetic tape, and a signal amplifier circuit 221 for amplifying the signal. And the signal amplification circuit 2
21 is provided with a brush 207 and a slip ring 205 for supplying power for driving, and rotary transformers 208 and 209 for transmitting the amplified signal to the outside. The signal amplification circuit 221 is a magnetic head of the rotary drum 201. 220 is mounted in a space facing the surface opposite to the mounting surface.

[0004]

However, the number of magnetic heads has increased along with the recent trend of noiseless and high image quality at the time of reproduction, and the number of channels of the rotary transformer has increased accordingly, resulting in crosstalk between channels. Since the number of signals increases and the signal from the magnetic tape becomes weak, the image quality and performance deteriorate.

As described above, there is a problem in that it is difficult to achieve both multi-channel and high image quality.

SUMMARY OF THE INVENTION An object of the present invention is to provide a rotary magnetic head drum device which can achieve both high channel number and high image quality of a video tape recorder and whose parts can be easily replaced.

[0007]

A rotary magnetic head drum device of the present invention transmits a signal between a rotary drum supported by a rotary shaft and rotating in contact with a magnetic tape, and a magnetic tape fixed to the rotary drum. A magnetic head, a signal amplifier circuit for amplifying a weak signal from the magnetic head to a sufficient level at the time of reproduction, a brush and a slip ring for supplying power to the signal amplifier circuit, and a non-contact external signal. In a rotary magnetic head drum device provided with two types of coaxial and flat plate rotary transformers for transmitting the electric power, and a fixed drum that holds the rotary shaft and faces the rotary drum, a signal amplification circuit is close to the magnetic head. The magnetic head is disposed in the space between the fixed rotary drum and the fixed drum.

Therefore, a weak signal section in which noise is easily picked up has been shortened.

In the rotary magnetic head drum device of the present invention, the rotor and the slip ring of the coaxial rotary transformer are fixed to a common fixing member having an axial hole, and the fixing member is attached to the rotating drum. The shaft hole of the fixed member is fitted to the rotary shaft of the rotary drum.

The rotary shaft is finished with high precision, and by assembling the fixing member with high precision on the rotary shaft, the assembly precision of the coaxial rotary transformer is improved, crosstalk can be suppressed, and replacement is easy.

[0011]

Next, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view of a rotary magnetic head drum device according to a first embodiment of the present invention. That is, the reference numeral 101 in FIG. 1 is a rotary drum, 102 is a fixed drum, 103 is a shaft, 105 is a slip ring, 107 is a brush, 108 is a flat plate rotary transformer, 108a is a flat plate rotary transformer stator, and 108b is a flat plate. Rotary transformer rotor, 109 is a coaxial rotary transformer, 109a is a coaxial rotary transformer stator, 109b is a coaxial rotary transformer rotor, 110 is a fixing member, 120 is a magnetic head, 121
Is a signal amplifier circuit.

In the magnetic head drum device, a magnetic head 120 for reproducing a signal from the magnetic tape, or conversely for recording a signal on the magnetic tape, and a signal amplifier circuit 121 for amplifying the signal. And the signal amplification circuit 1
21 a brush 107 and a slip ring 105 for supplying power for driving, rotary transformers 108 and 109 for transmitting an amplified signal to the outside, a rotary drum 101 to which a magnetic head 120 is fixed, and a rotary drum 101. The rotary drum 101 is provided with a fixed drum 102 that holds the shaft 103 of FIG.

In this embodiment, the conventional magnetic head 12 is used.
The signal amplification circuit 121 provided in the space on the opposite side of the rotary drum 101 away from 0 is built in the same space between the rotary drum 101 and the fixed drum 102 as the magnetic head 120.

Further, conventionally, the coaxial rotary transformer 20 is used.
Coaxial rotary transformer rotor 2
09b and slip ring 205 were attached to different fixing members and fixed to rotary drum 201 (FIG. 2). In the present embodiment, the coaxial rotary transformer rotor 109b and the slip ring 105 are the common fixed member 1
10, the fixed member 110 is attached to the rotary drum 1
01 is fixed to the rotary drum 101 by being fitted to the shaft 103 for mounting the rotary drum 101.

When recording a signal on a magnetic tape, the signal from the circuit first enters the coaxial rotary transformer stator 109a through the cable, is transmitted to the coaxial rotary transformer rotor 109b, and is transmitted via the relay board and the cable to the magnetic field. It is transmitted to the head 120 and recorded on the magnetic tape.

At the time of reproduction, the signal from the magnetic tape is transmitted to the magnetic head 120 and then to the signal amplifying circuit 121 arranged on the same surface of the rotary drum 101 to amplify a weak signal, and then to a flat plate. From the rotary transformer rotor 108b to the flat plate rotary transformer stator 108b
Is transmitted to the external circuit via the cable.

As described above, the magnetic head 120 and the signal amplification circuit 121 are fixed to the rotating drum 101, and the fixing member 110 is screwed onto the rotating drum 101. The fixing member 110 includes a coaxial rotary transformer rotor 109b for transmitting a signal from the outside when recording the signal on the magnetic tape, and a slip ring 105 for supplying power to operate the signal amplifying circuit 121 during reproduction. A hole which is positioned and fixed, and which is bored at the center is fitted to the tip of a shaft 103 which supports the rotating drum 101.

The shaft 103 is finished with a high precision of 1 μm or less, and the holes of the fixing member 110 are fitted with a high precision, so that the coaxial rotary transformer rotor 109b and the stator 109a are fixed even if the positioning is not performed. Spatial distance is maintained and stable signal transmission can be performed.

[0019]

As described above, according to the present invention, since the fixing member attached at the time of recording is fitted to the tip of the shaft for fixing the rotary drum, the rotary rotary transformer can maintain a constant spatial distance. After recording on the magnetic tape via the transformer and reproducing the signal from the magnetic tape with the magnetic head at the time of reproduction, it is transmitted to the signal amplification circuit in the same space as the magnetic head and in the close proximity to the magnetic head,
After the weak signal is amplified, it is transmitted from the rotor of the flat plate rotary transformer to the flat plate rotary transformer stator and is transmitted to the outside. Therefore, the effect of noise is small, the crosstalk between channels is small, and high image quality can be obtained.

Further, the coaxial rotary transformer rotor and the slip ring are positioned and fixed to the fixing member,
Since the hole drilled in the center is fitted to the tip of the shaft that fixes the rotating drum, and the shaft is finished with high precision,
Since the coaxial rotary transformer rotor and the slip ring can be easily fixed in place without special positioning by fitting the holes of the fixing member with high accuracy, the replacement time at the time of component replacement can be shortened. There is.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a rotary magnetic head drum device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a conventional rotary magnetic head drum device.

[Explanation of symbols]

101, 201 rotating drum 102, 202 fixed drum 103, 203 shaft 105, 205 slip ring 107, 207 brush 108, 208 flat plate rotary transformer 108a, 208a flat plate rotary transformer stator 108b, 208b flat plate rotary transformer rotor 109, 209 coaxial rotary transformer 109a , 209a Coaxial rotary transformer stator 109b, 209b Coaxial rotary transformer rotor 110 Fixing member 120, 220 Magnetic head 121, 221 Signal amplification circuit

Claims (2)

[Claims] 1. A rotary drum supported by a rotary shaft to rotate in contact with a magnetic tape, a magnetic head fixed to the rotary drum for transmitting signals between the magnetic tape, and a weak signal from the magnetic head during reproduction. Amplification circuit for amplifying the signal to a sufficient size, a brush and a slip ring for supplying power to the signal amplification circuit, and a coaxial type and a flat plate for transmitting signals to the outside in a non-contact manner. In a rotary magnetic head drum device including a rotary transformer and a fixed drum that holds the rotary shaft and faces the rotary drum, the signal amplification circuit is fixed to the magnetic head in proximity to the magnetic head. A rotary magnetic head drum device, wherein the rotary magnetic head drum device is arranged in a space between the rotary drum and the fixed drum. 2. A rotary drum supported by a rotary shaft and rotating in contact with a magnetic tape, a magnetic head fixed to the rotary drum for transmitting a signal between the magnetic tape, and a weak signal from the magnetic head during reproduction. Amplification circuit for amplifying the signal to a sufficient size, a brush and a slip ring for supplying power to the signal amplification circuit, and a coaxial type and a flat plate for transmitting signals to the outside in a non-contact manner. In a rotary magnetic head drum device including a rotary transformer and a fixed drum that holds the rotary shaft and faces the rotary drum, the rotor and the slip ring of the coaxial rotary transformer have a common fixing member having a shaft hole. And the fixing member is fixed to the rotating drum, and the shaft hole of the fixing member is fitted to the rotating shaft of the rotating drum. Rotary magnetic head drum apparatus characterized by being.