JPH01317204A - Information transmitting device - Google Patents

Abstract

PURPOSE:To attain the transmission of information with no influence of the resonance and the magnetic effect by setting the current/light converting elements at the information transmission side in the radiating direction to a rotary shaft together with the ring-shaped photodetectors set at the information reception side to receive the optical signals. CONSTITUTION:The current/light converting elements 10-13 are set at the information transmission side in the radiating direction to a rotary shaft. While the ring-shaped photodetectors 15-18 are set at the information reception side to receive the optical signals. In such a constitution, a four-structure reproduction system is obtained and therefore the heads counter to each other can reproduce two channels at one time. Then the inter-channel crosstalks can be easily reduced by separating the optical paths set between the elements 10-13 and the photodetectors 15-18. Thus it is possible to transmit the information with no influence of the resonance caused by the heads and a rotary transformer as well as the magnetic influence caused by the rotary transformer which supplies the electric power.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording/reproducing device that uses a plurality of rotating magnetic heads to simultaneously record and reproduce multiple pieces of information on a magnetic tape. This relates to a fixed-side information transmission device.

[Prior Art] Conventionally, a recording current is passed from a fixed stator side to a rotating magnetic head on the rotor side during recording, and a minute current is induced in the magnetic head on the rotor side (hereinafter referred to as the head) during playback. A so-called rotary transformer using magnetic coupling has been used as a means for sending a reproduced signal to the stator side.

FIG. 4 shows a conventional rotary transformer, in which a rotor 23 is magnetically coupled to a stator 25. As shown in FIG. This rotor 23 has a coil 21a that transmits signals from two heads 31 and 32.

A coil 22a is embedded. And this coil 2
Coils 21b and 22b embedded in the stator 25 opposite to 1a and 22a mutually constitute a transformer and transmit information.

The rotating head and rotor 23 are fixed to a motor shaft 26, and the stator 25 is fixed to a lower tram 24 of the rotating head assembly.

[Problems to be Solved by the Invention] In general, when digitally recording image signals as an information transmission means for recording/reproduction signals, the amount of information that must be recorded becomes significantly large, so it is difficult to simultaneously record and reproduce images using multiple heads. This requires so-called multi-track simultaneous recording and playback. In addition, in order to have a multi-track configuration and to suppress the cross stroke between channels, coaxially opposed rotary transformers are required, which has the disadvantage of increasing the external dimensions, especially in the axial direction, and increasing the size of the product's housing. there were. Also, record/record per channel.
As the amount of information to be reproduced increases, it is necessary to widen the recording and reproduction band. In order to widen the band, the resonance point of the LC due to the actance component of the rotary transformer and head, the input capacitance of the reproducing amplifier, the stray capacitance around the rotary transformer, etc. must be made higher than the band to which the signal is to be transmitted. Is it necessary to reduce the number of turns in the head or rotary transformer? As a result of reducing the number of turns, there was a drawback that the playback output decreased.

This invention was made in order to solve such conventional problems, and it is possible to transmit information without being affected by crosstalk between channels, resonance between heads and rotary transformers, and magnetic influences caused by rotary transformers. The purpose is to provide a transmission device.

[Means for Solving the Problems] The information transmission device of the present invention is provided with a current-light conversion element that converts information into an optical signal on the information sending side in a radial direction with respect to the rotation axis, and a current-light conversion element that converts information into an optical signal on the information receiving side. A ring-shaped light receiver is provided to receive a signal from the light from the conversion element.

[Function] With the above configuration, the reproduced signal from the rotary head can be transmitted without the effects of resonance or crosstalk due to magnetic coupling.

[Embodiment] FIG. 1 is a diagram showing an embodiment of an information transmission device of the present invention.

Figure 1 shows a case in which a magnetic tape is wound around a rotating cylinder for more than 180 degrees, and two channels are simultaneously played back using two pairs of heads facing each other at 180 degrees, since it is used in the playback system of a digital video recorder. Let me explain using an example. In FIG. 1, l is a rotating rotating drum, 2
, 3 are heads that play back at the same time, 4 and 5 are heads 180 degrees opposite head 2 and 3, 6 is an amplifier that amplifies the minute output from head 2, and 7 is an amplifier that amplifies the minute output from head 3. An amplifier, 8 is an amplifier that amplifies the minute output from the head 4, 9 is an amplifier that amplifies the minute output from the head 5, and IO is a current that converts the output current of the amplifier 6 into light.
An optical converter, 11 is a current-to-optical converter that converts the output current of the amplifier 7 into light, 12 is a current-to-optical converter that converts the output current of the amplifier 8 into light, and 13 is a current that converts the output current of the amplifier 9 into light. - a light converter; 14 is a balance weight for balancing the weight of the current-light converters 10, 11, 12.13 when rotating the rotating drum l; 15 is the light of the rotating current-light converter 10; A ring-shaped light-receiving element that receives the output, 16 a ring-shaped light-receiving element that receives the light output of the rotating current-light converter 11, and 17 a ring-shaped light-receiving element that receives the light output of the rotating current-light converter 12. , 18 is a ring-shaped light receiving element that receives the optical output of the rotating current-light converter 13.

Next, the flow of signals extracted by the head 2 will be explained with reference to FIG. FIG. 2 is a circuit diagram for one channel in the device shown in FIG. In FIG. 2, 19 is a power supply terminal, 20 is a load resistor, 21 is a bias resistor, 22 is a fixed side amplifier, 23 is an output terminal, and 24 is a power supply terminal.

Now, a minute signal extracted from a magnetic tape (not shown) by the head 2 is amplified by an amplifier 6 to a magnitude sufficient to drive a current-to-optical converter 10. A load resistor 20 is connected to the output of the amplifier 6.
A current corresponding to the output voltage of the amplifier 6 is passed through the current-to-optical converter 10. The current-light converter IO is, for example, a semiconductor laser diode or the like, and within a certain current range, emits light with an intensity proportional to the current.

The power for driving the amplifier 6 and the current-to-optical converter lO is provided by a conventional magnetically coupled rotary transformer (not shown).
Supply using.

The light-receiving element 15 is a ring-shaped photodiode in order to receive the light from the rotating current-light converter 10, and can receive information regardless of the rotation of the rotating drum l. The bias resistor 21 is a resistor for causing a bias current to flow through the light receiving element 15, and applies a voltage change to the amplifier 22 in accordance with a change in the received light. The signal applied to the amplifier 22 is amplified to an appropriate level and output to the output terminal 2.
3 is output.

In the apparatus of the embodiment shown in FIG. 1, by having the four reproducing systems shown in FIG. 2, simultaneous reproduction of two channels can be realized in each of the opposing heads. The inter-channel crosstalk can be easily reduced by isolating the optical path from the current-light conversion element to the light receiving element.

By using the configuration described above, crosstalk between channels, resonance between the head and the rotary transformer, and the magnetic influence of the rotary transformer that supplies power can be eliminated, which is a problem when using a rotary transformer with conventional magnetic coupling. It is possible to transmit information without receiving it.

In the above embodiments, the information transmission device according to the present invention is used when reproducing information from a magnetic tape using a rotary head, or contrary to the above embodiments, the recorded signal is reproduced using the information transmission device according to the present invention. Naturally, it is also possible to send it into a rotating drum. In that case, the photoelectric conversion mechanism may be reversed to the above embodiment, thereby eliminating crosstalk between channels, resonance between the head and the rotary transformer, and magnetic influence due to the rotary transformer that supplies power. Of course you can.

FIG. 3 is a diagram showing another embodiment of the information transmission device of the present invention. Similarly to the embodiment shown in Fig. 1, Fig. 3 is also used for the reproduction system of a digital tape recorder, so a magnetic tape is wound around a rotating drum at 180 degrees, and two channels are simultaneously played using two pairs of heads facing each other at 180 degrees. Take for example. In FIG. 3, the same reference numerals as in FIG. 1 indicate the same or corresponding parts.

In the embodiment of FIG. 3, a pair of heads 2 facing each other by 180°
Current-to-optical converters lO and 12 for transmitting information of and 4 are placed at point-symmetrical positions equidistant from the rotation axis.

Similarly, the current that transmits information between the pair of heads 3 and 5 facing each other -
The optical converters 11 and 13 are placed at symmetrical positions equidistant from the axis of rotation. When the magnetic tape is wound 180 degrees around the rotating tram l as in this embodiment, for example, after the head 2 starts contacting the tape and rotates 180 degrees,
If you prepare a light receiving element 15 that receives 180 degrees of light when the information reproduced before leaving the tape is converted by the current-optical converter lO, the remaining 180 degrees of information that is reproduced by the head 4 facing the head 2 is prepared. The information on the current-optical converter 10 180° opposite the current-optical converter 10 can be obtained without changing the head.
The light receiving element 15 can receive light from the optical converter 12. Similarly, regenerate data from head 3 and convert current to light converter 1.
If you prepare a light receiving element 16 for 180 degrees that receives light when converted by head 1, the remaining 180 degrees of information reproduced by head 4, which is opposite to head 3, can be converted from current to light without switching the heads. Light can be received by the light receiving element 16 from the current-light converter 13 which is 180 degrees opposite to the converter 11.

For example, by using the information transmission device according to the present invention, information can be transmitted without being affected by crosstalk between channels, resonance between the head and the rotary transformer, and magnetic influence by the rotary transformer that supplies power. Not only is this possible, but it also makes it possible to switch between 180° opposing heads, reducing the number of components on the receiving side. In this example, we have described a case in which a magnetic tape is wound 180 degrees around a rotating drum and information is switched between two heads facing each other by 180 degrees, or a magnetic tape is wound 120 degrees around a rotating drum and three heads separated by 120 degrees are to be switched. When switching the information on a rotating drum, or when switching the information on four heads spaced 90 degrees apart by winding magnetic tape around a rotating drum at 90 degrees, this can be achieved by arranging the receivers at 120 degrees or 90 degrees, respectively. It is possible to have a similar effect.

[Effects of the Invention] As explained above, in the information transmission device of the present invention, a current-to-light conversion element for converting information into an optical signal is provided on the information sending side in the radial direction with respect to the rotation axis, and the information receiving side is provided with the current-light conversion element that converts information into an optical signal. - By installing a ring-shaped receiver that receives the light signal from the optical conversion element, crosstalk between channels, which is a problem when using a conventional magnetically coupled rotary transformer, and resonance between the head and rotary transformer can be avoided. , and information can be transmitted without being affected by the magnetic influence of the rotary transformer that supplies power.

In addition, on the sending side, n current-light conversion elements that convert information from n information sources (n is an integer of n≧2) into the intensity of light, respectively, are provided on the same plane and shifted by 360/n degrees. By providing a 360/n degree photoreceptor, which is part of a ring-shaped photoreceiver that receives the light from the current-light conversion element, on the receiving side, it is possible to switch between multiple information sources by rotating them. This also has the effect of reducing the number of constituent parts.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1 is a diagram showing an embodiment of the information transmission device of the present invention, FIG. 2 is a circuit diagram for one channel in the device of FIG.
FIG. 3 is a diagram showing another embodiment of the information transmission device of the present invention;
FIG. 4 is a diagram showing a conventional rotary transformer. In the figure. Rotating drums 2.3, 4, 5: Heads 6.7, 8, 9: Amplifiers 18. 11, 12, 13: Current-light converters 14: Balance weights 15. 16, 17, 18: Light receiving elements 19. Power supply terminal 20: Load resistance 21: Bias resistance 22/Amplifier 23: Output terminal 24: Power supply terminal Representative Patent attorney 1) Haru Kitatake Figure 1 Figure 2

Claims (2)

[Claims] (1) In an information transmission device that has a fixed side and a rotating side that are arranged opposite to each other, and the fixed side and rotating side mutually transmit information, an electric current is applied to the information sending side to convert information into an optical signal. - An information transmission device characterized in that a light conversion element is provided in a radial direction with respect to a rotation axis, and a ring-shaped light receiver is provided on an information receiving side to receive an optical signal from the current-light conversion element. (2) On the information sending side, n current-light conversion elements that convert information from n information sources (n≧2 integer) into optical signals are installed on the same rotation plane, shifted by 360/n degrees, 2. The information transmitting device according to claim 1, further comprising a 360/n degree ring-shaped light receiver provided on the information receiving side to receive the optical signal from the current-to-light conversion element.