JPS5857603A - Rotary magnetic head device - Google Patents

Abstract

PURPOSE:To obtain a rotary transformer having excellent characteristics, by introducing the optical signal from the single side of an annular light guide provided to a rotor and a stator respectively and converting the optical signal photoelectrically at an optical output terminal. CONSTITUTION:A light source driving circuit 2r is driven by an output signal 11 of a magnetic reproducing head 1 attached to a rotor 10, and a modulated optical signal 12 is irradiated from a light source 3. The optical signal 12 made incident to an annular light guide 21 goes into the guide 21 with repetitive reflection and undergoes a photoelectric conversion 22 at the edge of the guide 21 to deliver a signal 31. While an input signal 32 undergoes a photoelectric conversion 5 and an amplification 6 through a light source driving circuit 23, a light source 24 and a light guide 4 to be recorded on a tape by a recording head 7. The light guides 4 and 21 transmits the light with high efficiency since a part of the circular section of a ring in parallel to the surface forming the ring is scraped off to obtain a plane 40 which is then polished. In such way, a rotary transformer of a rotary magnetic head having excellent characteristics is obtained with a simple assembly.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a rotary magnetic head device used in a storage device @rc using magnetic tape. In order to improve the recording density without increasing the relative speed between the head and the medium and without increasing tape consumption, the cylindrical drum to which the magnetic head is attached is rotated, and the drum is rotated in a direction diagonal to the direction of travel of the magnetic tape. Alternatively, there is a method in which recording and reproduction are performed by scanning a magnetic tape with a magnetic head in a perpendicular direction. In the rotary magnetic head devices used in such devices, a rotary transformer is often used as a means for transmitting recording and reproducing signals between the rotor on the rotating side and the stator on the stationary side. In signal transmission using such a rotary transformer, due to its electrical characteristics, the passing frequency characteristic is narrow band, and since it is transformer coupled, it is difficult to pass low frequency components. Therefore, a code with as few reduction components as possible is generally selected as the modulation code used during recording. However, for this reason, it is not always necessary to use Nt as a recording/reproducing system.
The situation is that an appropriate modulation code cannot be selected. In addition, there are structural problems such as variations in the gap size between the 1 medical coil and the secondary coil of the rotary transformer, an increase in the capacitance between the coils when the gap size is small, and the rotor + J coil. Due to the narrow band nature of the transformer, the signal passing through the rotor IJ lance is adversely affected by phase shifts and level fluctuations.

Various types of waveform compensation have been implemented to deal with such deterioration of No. 48, but there are limits to this, and as the signal frequency handled increases, transformer coupling tends to become capacitive coupling, etc. It also comes with difficulties.

As described above, there are various problems in the rotary magnetic head device using a single rotary transformer, and some kind of solution is desired in order to improve the performance and stabilize the performance of the magnetic recording device.

The purpose of the present invention is to effectively solve the following problems, ensure more accurate and high quality signal transmission, and provide a rotary magnetic device that is easy to manufacture and easy to manufacture. It is in.

According to the present invention, the rotary type device 9. optically transmits recording and reproducing information between the rotor and the stator in a rotary type respiration recording and reproducing device. In the head device, a light guide is formed in a ring shape, has one side as a light receiving surface, receives original information from the rotor or stake, and has its light output end connected to a photodetector. Explain in detail.

FIG. 1 is a schematic diagram showing a first embodiment of the present invention, and FIG. 2 is a diagram showing the shape of a link-shaped light guide used in the embodiment of the present invention. FIG. 3 is a schematic diagram showing a second embodiment of the present invention.

The rotary magnetic head/node device of the present invention shown in the first embodiment has a rotor 10, a reproducing magnetic head 1, a first light source drive circuit 2, a first light source 3, and a first ring-shaped light guide. A second ring-shaped light guide 21 and a second photodetector 22 are attached to the stator 4, the first photodetector 5 and the recording head 1, and the stator 6 and the recording magnetic head 7. and a second light source driving circuit and a second light source 2a, the first link-shaped light guide 4 and the second ring-shaped intelligent light body 21 are respectively arranged on a concentric circle of the rotor rotation axis. The first light source 3 and the first link-shaped light guide 4 are configured to rotate together with the rotor 10. The operation of each part will be explained below. A weak reproduction signal 11 from a reproduction magnetic head 1 attached to the rotor W is amplified by a first light source drive circuit 2, and a first light source 3 such as a light emitting diode or a laser diode attached to the stator.
supplied to The reproduced information light 12 corresponding to the weak reproduced signal 11 emitted from the first light source 3 is irradiated onto a second ring-shaped light guide 21 attached to the stator microscope, and further propagates therein. The light is guided by a second photodetector 221 attached to one end of the second ring-shaped light guide 21, photoelectrically converted, and output as a reproduced electric signal 31. The recording electric signal 32 supplied to the rotary magnetic head device of this embodiment passes through the second light source drive circuit section and is emitted from the second light source 24 as recording information light toward the rotor IO. Further, the recording information light 33 is irradiated onto the first ring-shaped light guide 4 attached to the rotor lO, further propagates therein, and is attached to one end of the first ring-shaped light guide 4. The signal is guided to the first photodetector 5, becomes a recording signal 13, is inputted to the recording amplifier 6, and is supplied to the recording magnetic head 7 as a recording current signal 14.

The rotary magnetic head device of this embodiment is constructed as described above, but the electric power required for the electronic circuits such as the first light source drive circuit 2 and the recording amplifier 6 that are connected to the rotor is It is supplied from the stator side using a slip ring, rotary transformer, etc.

Also, the first and second ring-shaped light guides used in this example will be explained.

Figure 2 is a diagram showing the shape of the ring-shaped light guide;
is a front view, and the same figure (b) is the same figure (A shown in the figure al).

A cross-sectional view taken along a line connected by A', and FIG. 6(c) is a schematic diagram showing the state of propagation of information light in the ring-shaped light guide. The first or second ring-shaped light guide 4 or 21 used in this embodiment is made of a transparent material such as glass or plastic and has a donut shape as shown in FIG. 2(a). As shown in FIG. Alternatively, the second ring-shaped light guide 4 or 21 is
A suitable amount is removed from one side of the ring parallel to the surface formed by the link to form the light receiving surface 40, and the surface is sufficiently polished, and its cross-sectional shape is as shown in Fig. 2(b). is formed in the shape of a partially cut out circle. In the first or second ring-shaped light guide 4 or 21 formed in this way, the light-receiving surface 40 has a photodetector facing toward one end of the ring-shaped light guide to which the ear Z is attached. The recording/reproducing information light 12 or 33 is irradiated by selecting an incident angle such that the recording/reproducing information light 12 or 33 propagates while repeating total reflection inside the light guide, thereby ensuring that the recording/reproducing information light 12 or 33 is transmitted to the first or second light guide. can be transmitted to the photodetector 5 or 22. The width of the light receiving surface 40 formed on the ring-shaped light guide is equal to the width of the light receiving surface 40 formed on the ring-shaped light guide.
In order to prevent the information light incident from 0 from being emitted from the light receiving surface 40 again before reaching the other end, that is, from 11
In order to have a wide degree of freedom in the angle of incidence of the telegraph light on the light receiving surface, it is better to make it as narrow as possible. Furthermore, the degree of freedom in the angle of incidence can be further widened by curving the ring-shaped light guide excluding the light-receiving surface 40.

In the rotary magnetic head device of this embodiment configured as described above, since signals are transmitted between the rotor 10 and the stator 20 optically, essentially the frequency band of the recording/reproducing signal is This eliminates the need to set restrictions on the modulation method for magnetic recording, and also eliminates signal deterioration in the transmission path that occurs when rotary transformers are used, allowing stable and high-quality recording and reproduction signals to be transmitted. obtain.

In addition, the present invention can also perform high-precision assembly work that is necessary when assembling a rotary magnetic head device using a rotary transformer, such as setting the gap size between the primary coil and the secondary coil of the rotary transformer. This invention is not necessary for assembling a rotary magnetic head device, and can be easily assembled, resulting in a reduction in manufacturing costs. The above-mentioned channels can also be easily formed, and the effects of the present invention are very large. 0 Next, the second aspect of this saturation, the shaft side, will be explained.

Figure 3 is a schematic cross-sectional diagram of the second Sζζ reference example of Hondo Akira,
In the figure (a), three ring-shaped light guides are arranged on a plane, and in the same figure (color), three link-shaped light guides are arranged three-dimensionally overlapping each other.

The rotary magnetic head device according to the second embodiment of the present invention shown in FIG. light body 4
The stator 20 has a second ring-shaped light guide 21 and a second photodetector. 22 and 2nd
In the rotary magnetic head device, the three first links shown in FIG. The same figure (b ) In the magnetic head device, the three first ring-shaped light guides 4'J3 and the three second ring-shaped light guides 21 are rotated around the rotation axis of the rotor lO. Three stages are arranged on the cylindrical surface and on the cylindrical inner surface of the stator facing thereto.

The operation of each circuit, the method of supplying power to the rotor, and the shape of the ring-shaped light guide in this embodiment are the same as those in the first embodiment of the present invention, and therefore will not be described here.

In the rotary mountain head device of this embodiment configured as described above, simultaneous recording and reproduction of multiple channels can be performed. In particular, when the ring-shaped light guide is arranged on a cylindrical surface, the rotor 10 or The number of optical transmission systems can be easily increased without imposing restrictions on the diameter of the stator. The other effects are the same as those of the first embodiment, so they will be omitted. The present invention has been explained above with reference to the drawings, but the signals transmitted between the rotor and stator of this device may be analog or digital. Either is fine. Also, although not specified in the shape of the magnetic head, the system of each electronic circuit, or the embodiments of the present invention, the number of ring-shaped light guides is It is only necessary to determine the number of IJ signals according to the number of necessary signals, and it is not necessarily necessary to set the number of IJs, and changes can be made without departing from the gist of the present invention.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a first embodiment of the present invention. FIGS. 2(b) and 2(c) are schematic diagrams showing the shape of a ring-shaped light guide used in an embodiment of the present invention. Figure 3 (a
), (b)! FIG. 3 is a schematic cross-sectional view showing a second embodiment of the present invention. In each figure, 1... read magnetic head, 2... first
a light source drive circuit; 3...first light source;
4...First link-shaped light guide, 5...
...first photodetector, 6...recording amplifier,
7... Recording magnetic head, 10...
Rotor, 11... Weak reproduction signal, 12...
...Reproduction information light, 13...Record signal, 14.
... Recording current signal, 20 ... Stator,
2]...Second ring-shaped light guide, 22...
...Second photodetector, Imperial order...Second light source drive signal, 32...Record electrical signal, 33...
Recording information light, 40... indicates a light receiving surface. Sai I Minister=22- Sai 2 figure or22 ”) 5or22 (C) O 3 figure (α) O 3 figure (b) 0 23

Claims (1)

[Claims] In a rotary magnetic head device in which recording and reproduction information is optically transmitted between a rotor and a stator in a rotary magnetic head device 1, a rotary magnetic head device is formed in a ring shape and has one side as a light receiving surface to receive optical information from the rotor or stator. A rotary magnetic head device characterized in that a light guide body having a light output end connected to a photodetector is disposed on a rotary stator or rotor with the same center axis.