JPS59188804A - Rotary head type magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To attain the signal transmission with high stability and high reliability with no effect of magnetic noise generated from a motor, etc. even in case a drum is revolved by a direct drive system, by transmitting optically signals between a magnetic head and a recording/reproducing circuit. CONSTITUTION:A hollow shaft 4 and a rotary drum 5 are revolved with revolutions of a motor 15. Then magnetic heads 6 and 7 scan helically the surface of a magnetic tape at high speed to reproduce the recorded signal. This reproduced signal is amplified by preamplifiers 19 and 20 and converted into the optically modulated signal by optical modulators 21 and 22 respectively. This modulated signal is supplied to the 1st and 2nd light emitting elements 8 and 16 respectively. Thus the elements 8 and 16 emit light in response to the signals reproduced by magnetic heads 6 and 7, and these emitted light are received by the 1st and 2nd photodetecting elements 9 and 17 and turned into electrical signals. These electrical signals are demodulated by optical demodulators 23 and 24 to the signals obtained before modulation and then processed by signal processing circuits 25 and 26 to be turned into reproduction outputs.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a rotary head type magnetic recording/reproducing device, and more particularly to an improvement in signal transmission means between a magnetic head and a recording/reproducing circuit.

[Technical background of the invention]

A rotary transformer is generally used as a signal transmission means between a magnetic head and a recording/reproducing circuit in a rotary head type magnetic recording/reproducing device. As is well known, this rotary transformer utilizes electromagnetic contact between conductors disposed on opposing surfaces of a rotating drum and a fixed drum.

[Problems with background technology]

Those using such a rotary transformer have the following problems. In other words, in video teso recorders and the like, a so-called direct drive system is adopted in which a rotating drum equipped with a magnetic spatula is directly driven by a motor, so the magnetic force of the motor is applied to the signal transmitted via the rotary transformer. Intervening as magnetic noise. For this reason, there is a problem in that it is difficult to avoid deterioration of the SLN product due to an increase in magnetic noise. In addition, the so-called belt-drive φ type, which transmits the rotation of the motor to the rotating drum via a belt, is less stable and reliable than the direct drive type, so it is rarely used these days. not being used.

[Purpose of the invention]

An object of the present invention is to be able to perform stable and reliable signal transmission without being affected by magnetic noise generated from a motor etc. even when a rotating drum is rotated using a direct drive method. An object of the present invention is to provide a rotary head type magnetic recording/reproducing device.

[Summary of the invention]

In order to achieve the above object, the present invention is characterized in that signal transmission between the magnetic head and the recording/reproducing circuit is carried out optically, thereby preventing interference of magnetic noise from a motor or the like.

[Embodiments of the invention]

FIG. 1 is a side view showing the structure of an embodiment of the present invention, cut away from the right half.

In FIG. 1, 1 is a chassis, on which a fixed drum 2 is installed and fixed. A hollow shaft 4 is rotatably inserted into the center of the fixed drum 2 via a bearing 3. A center portion of a rotating drum is fitted and fixed to one end (upper end in the figure) of the hollow shaft 4, and rotates together with the hollow shaft 4. A pair of magnetic heads 6.7 are attached to one side of the rotating drum 5 facing the fixed drum 2. The pair of magnetic heads 6.7 are connected to the rotating drum 5 and the fixed drum 2.
The magnetic tape (not shown) is wound around the circumferential surface of the magnetic tape at an angle, and the magnetic tape is rotated at high speed while making contact with the magnetic tape (not shown), thereby performing so-called edge scanning and reproducing the signals on the magnetic tape. be. rotating drum 5
A base end portion of a first light emitting element 8 is buried and fixed in the center of the other side surface not facing the fixed drum 2 . This first light emitting element 8 has one side of the magnetic head 6.7, for example 6.
A reproduced signal from the is provided via a serial amplifier and an optical modulator, which will be described later. A first light-receiving element 9 is attached to a fixed portion 11 while being surrounded by a light-shielding hood 10 so as to face the light-emitting end of the first light-emitting element 8. A donut-shaped solar cell 12 is attached to one side of the rotating drum 5 on which the light emitting element 8 is attached. A pair of rungs 13 and 14 are attached to the fixed portion 1 so as to face the light-receiving surface of the solar cell 12. Note that the solar cell 12
is connected to a preamplifier, optical modulator, etc., which will be described later.

A central portion of one end surface of a rotor 15a of a direct drive motor 15 is coupled to the other end (lower end in the figure) of the hollow shaft 4. A base end portion of a second light emitting element 160 is embedded and fixed in the center of the other end surface of the rotor 15a. This second light emitting element 16 receives a reproduction signal from the other magnetic head 6, 7, for example, from a serial amplifier, which will be described later.
Provided via a light modulator. In this case, the optical modulator and “
Signal transmission between the second light emitting element 16 and the hollow shaft 4
This is done through a signal line (not shown) inserted into the .

A second light receiving element 17 is attached to the fixing member 18 so as to face the light emitting end of the second light emitting element 16.

FIG. 2 is a block diagram showing the circuit configuration of the same embodiment.

As shown in FIG. 2, the magnetic head 6.7 has a serial amplifier 1.
The output terminals of the serial f19.20 are connected to the input terminals of optical modulators 21.22, respectively. The first and second light emitting elements 8.16 are connected to the output ends of the optical modulators 21.22, respectively. Preamplifier 19.20 and optical modulator 21
, ;l'2 is supplied with power from the solar cell 12.

On the other hand, the first. The second light receiving element 9.17 is connected to the light adjuster 23.
The output ends of the optical demodulators 23 and 24 are connected to the input ends of signal processing circuits 25 and 26, respectively.

Next, the operation of the apparatus configured as described above will be explained. When power is supplied to the lamps 13.14 from the main body of the apparatus, the lamps l'3.14 emit light.

The light energy emitted from the lamps 13 and 14 is converted into electrical energy by the solar cell 12.
, 191.20 and the optical modulator 21.22.

When power is supplied to the motor 15 in this state, the motor 15
rotates, and the hollow shaft 4 and rotating drum 5 are rotationally driven. Therefore, the magnetic head 6.7 helically skins the magnetic tape at high speed to reproduce the recorded signal. The reproduced signals are each amplified by preamplifiers 7619.20 and then converted into optical modulation signals by optical modulators 21.22, which are supplied to the first and second light emitting elements 8.16. Therefore, the first and second light emitting elements 8.16 emit light in accordance with the signal reproduced by the magnetic head 6.7. Light emitted from the first and second light emitting elements 8.16 is received by the first and second light receiving elements 9.17, respectively, and becomes an electrical signal. These electrical signals are demodulated into unmodulated signals by optical demodulators 23 and 24, and then signal processing circuits 2 and 24 respectively demodulate the electrical signals.
The signal is processed in step 5.26 and becomes a reproduced output.

In this way, in this device, the reproduced signal obtained by the magnetic head 6.7 is converted into an optical signal by the first and second light emitting elements 8.16, and the first and second light emitting elements installed on the fixed side are converted into optical signals. Since the signal is transmitted to the second light receiving element 9.17, there is no possibility that magnetic noise generated from the direct drive motor 15 or the like will interfere with the signal transmission section. Therefore, S/Nb-=e
There is no deterioration in performance, and stable playback operation can be performed.

In addition, in this device, unnecessary power is supplied to the optical modulators 21, 22, etc. by optical transmission between the lamps 13, 14 and the solar cell 12, so compared to mechanical transmission means such as brushes and commutators. , no noise or noise generation, and high reliability.

Note that the present invention is not limited to the embodiments described above. For example, in the above embodiment, two 1-heads 6
．． 7 to the first and second light emitting elements 8.7, respectively.
16 and the first and second light-receiving elements 9.17 independently transmit light, but it is also possible to transmit light by a common set of light-emitting element and light-receiving element. It's okay. However, in this case, it is necessary to modulate the signals from each magnetic head 6.7 at different frequencies and to transmit them in a superimposed manner. Further, in the above embodiment, the present invention was applied to a signal reproducing device, but it can also be applied to a signal recording device. In this case, a light modulator, a light emitting element, etc. may be mounted on the fixed side, and a light receiving element, a light demodulator, etc. may be provided on the rotating drum side. It goes without saying that various other modifications can be made within the scope of the invention without departing from the gist of the invention.

[Effects of the Invention] According to the present invention, signal transmission between the magnetic head attached to the rotating drum and the recording/reproducing circuit provided on the fixed leg is carried out using a magnetic head installed at the axial center of the rotating drum. Even in the case of a light-emitting element or a light-receiving element and a light-receiving element installed facing it, a stable and reliable signal can be obtained without being affected by magnetic noise generated from the motor, etc. A rotary head type magnetic recording/reproducing device capable of transmitting data can be provided.

[Brief explanation of drawings]

1 and 2 are diagrams showing one embodiment of the present invention. FIG. 1 is a side view showing the structure of the main part cut away from the right half, and FIG. 2 is a block diagram showing the circuit structure. 1... Chassis, 2... Okiya drum, 3... Bearing, 4... Hollow shaft, 5... Rotation! Param, 6.
7...Magnetic head, 8...First light emitting element, 9...
1st light receiving element, 10... Shade hood, 12... Solar cell, 13.14... Lamp, 15... Motor,
16... Second light emitting element, 17... Second light receiving element. Applicant's agent Takehiko Suzue, Commissioner of the Patent Office
Kazuo Wakasugi 1. Display of the case Japanese Patent Application No. 58-63322 2, Name of the invention Rotating head type magnetic recording reciprocating device 3, Person making the amendment Relationship to the case Patent applicant (037) Olympus Optical Industry Co., Ltd. 11, Agent 6, Target of correction

Claims (1)

[Claims] The apparatus comprises a motor, a rotating drum rotationally driven by the motor, a magnetic head attached to the rotating drum, and means for optically transmitting signals between the magnetic head and the recording/reproducing circuit, The means for optically transmitting signals includes a rotating side light emitting element and/or a light receiving element installed at the axial center of the rotating drum and connected to the magnetic head via an optical modulator and/or an optical image modulator; A stationary side light receiving element and/or light emitting element is arranged opposite to the rotating side light emitting element and/or the light receiving element with a predetermined gap and connected to the recording/reproducing circuit via an optical demodulator and an optical modulator. A rotating head type magnetic recording and reproducing device with special features.