JPS63155403A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute various controls to a signal processing circuit on a rotary drum from the outside of the rotary drum without providing a transmission line of a control signal especially, by transmitting a control signal by using the same rotation coupling means for transmitting a recording signal or a reproducing signal in a format drop-out period. CONSTITUTION:A rotary drum 1 is provided with signal processing circuits 10a-10d, a control signal receiving circuit 11, and a control signal storing circuit 12, and also, a control signal transmitting circuit 16 is provided on a fixing part side for supporting the rotary drum 1. Also, this device is provided with a control signal transmission means for transmitting a control signal from a control signal transmitting circuit 16 to a control signal receiving circuit 11 by using a rotation coupling means for transmitting a recording signal or a reproducing signal, in a period (format drop-out period) 8 in which a magnetic transducer does not abut on a magnetic recording medium wound round extending over a prescribed angle range in the periphery of the rotary drum 1. In such as way, various control signals can be transmitted from the outside of the rotary drum 1 to the signal processing circuit 10a-10d on the rotary drum 1 without giving any disturbance to a recording signal and a reproducing signal, without providing especially an exclusive transmission line for a control signal.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Application Field) The present invention is directed to a magnetic recording device that controls a signal processing circuit built into a rotating drum during a period when a magnetic transducer is not in contact with a magnetic recording medium. The present invention relates to a playback device.

(Prior Art) In a magnetic recording and reproducing device that records or reproduces at least a wideband signal such as a video signal or a PCM audio signal, a magnetic transducer (hereinafter referred to as a magnetic head) is placed approximately on the circumference of a rotating drum. A magnetic recording medium (
Currently, the most common type of device is the so-called helical scan type, in which a tape (hereinafter referred to as "tape") is wound around a rotating drum within a predetermined angle range, and the relative speed between the magnetic head and the tape is increased to enable recording and playback of high-frequency signals. It is widely used for both commercial and consumer use.

In recent years, there has been an increasing demand for smaller, more multi-functional and longer V 1' R, as well as higher frequency and higher density recording such as recording of high definition television signals and recording of PCM video signals. Along with this trend, the wavelength of recording signals is becoming shorter, recording tracks are becoming narrower, and recording channels are becoming more multi-channeled.

However, shorter wavelengths of recording signals and narrower recording tracks result in lower reproduction signal levels and S/N
There is a problem of deterioration of the material, so it is not preferred in practice.

In addition, in a so-called helical scan type magnetic recording and reproducing device, the magnetic head is installed on a rotating drum, so signals to be recorded on the tape and signals read from the tape are transferred to a rotating coupling means such as a slip ring or a rotary transformer. It is transmitted via.

An example of the construction of one part of this magnetic recording/reproducing device is shown in FIG. There is a recording amplifier 103 on the side. playback amplifier 10
4. A recording/reproduction changeover switch 105 is provided, and the magnetic head 10 is connected to the magnetic head 10 via a rotary transformer 106.
Recording signals and reproduction signals are transmitted between the recording amplifier 103 and the reproduction amplifier 104.

However, the magnetic head 102 and both amplifiers 103 and 104
If the rotary transformer 106 is interposed between the two, signal transmission quality will be significantly degraded, and this will become an obstacle to recording and reproducing high frequency signals.

In order to solve this problem, Japanese Patent Application Laid-Open No. 60-24501
No. 61-42701, etc., a recording amplifier, a reproduction amplifier, and an associated switching circuit are provided on a rotating drum, and the magnetic head and the recording amplifier or reproduction amplifier are directly connected to improve the recording and reproduction characteristics of high-frequency signals. An improved version has been disclosed.

As shown in FIG. 6, this magnetic recording/reproducing apparatus includes a rotating drum 201 and a magnetic head 202, which is not indicated by a chain double-dashed line in the figure. Reproduction amplifier 203. The recording amplifier 204 has built-in recording/reproduction changeover switches 205 and 206, and transmits and receives recording signals and reproduction signals via a rotary transformer 207. At this time, the reproduction amplifier 203. Recording amplifier 204
The power is supplied from outside the rotating drum 201 to the slip ring 208.
It is supplied via the changeover switch 205゜206.
is designed to operate when power is supplied to the recording amplifier 204. In this device, a linear amplifier is used as the recording amplifier 204, and the recording current flowing to the magnetic head 202 is determined by the level of the recording signal sent via the rotary transformer 207.

By directly connecting the reproducing amplifier 203 and the recording amplifier 204 to the magnetic head 202 in this way, it was possible to improve the broadband characteristics and S/N as compared to the conventional example shown in FIG.

However, as is well known, when a linear amplifier is used, its broadband characteristics are inferior to that of a recording amplifier driven by a constant current switch, and it also generates a large amount of heat, making it difficult to miniaturize.

Therefore, a method using a recording amplifier driven by a constant current switch has been proposed, but in this case, a control line is required to externally control the recording current.

To solve this problem, a dedicated line for recording current control is added to the slip ring 208, or a control signal is transmitted using another dedicated rotary transformer.

However, in a multi-channel recording/reproducing device that uses a large number of magnetic heads, the number of control lines increases in proportion to the number of magnetic heads, making the mechanism complex and making it easier to downsize and lower costs. Additionally, there is a problem in that the number of channels that can be mounted on the rotary drum 201 is limited due to restrictions on the mechanism for transmitting control signals.

On the other hand, in cases where advanced editing operations are required, such as in professional VTRs, it is impossible to make the slip ring 208 serve both as a power source and a recording/playback switching control signal as shown in Figure 6, so the power source is It is necessary to send and receive control signals independently. Furthermore, when other signal processing circuits such as a reproduction equalizer are mounted on the rotating drum, the number of control signals that must be applied to the rotating drum from outside the rotating drum increases considerably.

In this way, when performing broadband high-density recording, the playback amplifier 203. When installing the recording amplifier 204 and its accompanying switching circuit on the rotating drum to improve its performance, the method of transmitting the control signals that control the circuits on the rotating drum becomes an important issue, and the number of control signals increases. There is a problem that the mechanism becomes even more complicated as the number increases.

(Problems to be Solved by the Invention) As mentioned above, in the prior art, in order to transmit control signals, a dedicated transmission line is provided or a transmission line for power supply to the circuit on the rotating drum is used. It is being used for both purposes. The former is problematic when a large number of control signals are required, such as in a multi-channel recording/reproducing device, and the latter is problematic when advanced control is required, such as in editing.

The present invention has been made in view of the above-mentioned problems, and it is possible to significantly improve performance in wideband, high-density recording, and to downsize the device.

It is an object of the present invention to provide a magnetic recording/reproducing device that can have multiple channels and multiple functions.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a rotating drum with a signal processing circuit, a control signal receiving circuit, and a control signal storage circuit, and transmits a control signal to a fixed part that supports the rotating drum. A circuit is provided to transmit a recording signal or a reproduction signal during a period when the magnetic transducer is not in contact with a magnetic recording medium wound over a predetermined angle range around a rotating drum (hereinafter referred to as a format dropout period). The present invention is characterized in that a control signal transmitting means is provided for transmitting a control signal from the control signal transmitting circuit to the control signal receiving circuit using the rotational coupling means.

(Function) In the magnetic recording and reproducing apparatus of the present invention, the control signal transmission circuit on the fixed part side modulates the control signal to be given to the signal processing circuit on the rotating drum, and this modulated control signal is transmitted to the rotating drum during the format dropout period. The signal is sent to the control signal receiving circuit via the coupling means and demodulated. Here, the demodulated control signal is held in the control signal storage circuit for a predetermined period and then sent to the signal processing circuit.

In this way, the control signal can be transmitted using the same rotary coupling means that transmits the recording or reproduction signal during the format dropout period, when the magnetic transducer is not in contact with the magnetic recording medium, so that the recording or reproduction signal can be transmitted using the same rotary coupling means. A wide variety of controls can be performed on the signal processing circuit on the rotary drum from outside the rotary drum without causing similar interference to signals and without providing a special transmission line for control signals.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. Figure 1 shows a high-definition VT using a 1-inch tape according to the present invention.
1 is a rotating drum, and on one surface of this rotating drum, four recording/reproducing magnetic heads 2a to 2d and four simultaneous reproducing magnetic heads are shown. A tape 7 is wound by an entrance guide 5 and an exit guide 6 in an angular range of about 350° around the zero-rotation drum 1 on which the rotary erasing magnetic heads 3a to 3d and the rotary erasing magnetic head 4 are provided. At this time, the angular range of about 10° in which the tape 7 does not come into contact with the rotating drum 1, indicated by 8, becomes the format dropout period, and during that time, the rotating drum 1 is
When rotating at 0 Hz, the time is approximately 500 μs.

Next, FIG. 2 is a circuit diagram showing the electric circuit of this embodiment. For convenience of explanation, parts related to the transmission of control signals, which is the gist of the present invention, are mainly shown, and unnecessary parts are omitted. , on this rotating drum 1 is the signal processing date #11.
0a-10d.

Control signal receiving circuit 11. A control signal storage circuit 12 is mounted. Each of the above-mentioned signal processing units B 10a to 10d is composed of a recording amplifier, a reproduction amplifier, and an associated switching circuit, and the recording/reproduction dual magnetic field 2a to
2d and the rotary transformers 13a to 13d. A control signal receiving circuit 11 is connected to the first channel line, and a control signal storage circuit 12 is connected to the output terminal thereof. The output end of this control signal storage circuit 12 is connected to each signal processing circuit 10a to 10d.

In addition, the rotary transformer 13 of the first channel line
a is connected to the electric circuit 15 on the fixed part side via the switching circuit H14, and is connected to the rotary transformer 1 of the other channel line.
3b to 13d are directly connected to the electric circuit 15. A control signal transmitting circuit 16 is connected to the output end of the electric circuit B15, and the output end is connected to the other fixed terminal of the switching circuit 14.

The electric circuit 15 is a rotary transformer 13a to 13d.
It processes the recording signal and reproduction signal sent and received via the , and also gives a control signal and timing pulse to control signal transmission day #116. This control signal and timing pulse are the control signal transmission date F! Modulated by @16.

Then, when the control signal transmitting circuit 16 is switched and connected to the rotary transformer 13a for the format dropout period by the switching circuit 14, the modulated control signal is transmitted to the control signal receiving port B11 via the rotary transformer 13a. . Here, except for the format dropout period, the rotary transformer 13a and the electric circuit 15 are connected by the switching circuit #114, and the recording signal and the reproduction signal are transmitted to the signal processing circuit n10a via the rotary transformer 13a. . Regarding other channel lines, signal processing circuits 10b to 10d and electric circuit 1
Recording signals and playback signals are directly transmitted and received between the controller 5 and the controller 5.

The control signal transmitted via the rotary transformer 13a during the format dropout period described above is demodulated by the control signal receiving circuit 11, stored once in the control signal storage circuit 12, and then sent to the signal processing circuits 10a to 10d. It will be done.

Next, transmission of control signals will be explained using specific circuits shown in FIGS. 3 and 4. Figure 3 shows the control signal transmission date R16.
The 18th ellipse diagram, Figure 1, shows the details of the functions of
1 is a circuit configuration diagram without showing the details of the functions of the control signal storage circuit 120 and the control signal storage circuit 120.

In FIG. 3, 21a to 21d are trimmers that adjust the recording current of each channel, and an A/D converter 22a.
~22d"C" PCM-converted control signals S1a-Sld
is sent to the parallel/serial converter 23 and converted into serial data. Also, from the electric circuit 1!315, the recording/reproduction switching control signals S2a to S2d of each channel are sent in parallel, 7
'It is sent to the serial converter 23 and converted into serial data. The operation timing of the parallel/serial converter 23 is determined by the timing pulse S3 from the electric circuit H15 and the format dropout timing pulse S4. Control signals Sla to Sld and recording/reproduction switching control signals S2a to
S2d is sent to the amplitude modulator 24 as a time division multiplexed output signal S5 within a format dropout period;
Here, the signal is amplitude modulated and sent to the rotary transformer 13a.

The control signal S6 transmitted via the rotary transformer 13a is transmitted to the demodulator 3 of the control signal receiving circuit 11 shown in FIG.
1 is input. The demodulator 31 demodulates the amplitude demodulated control signal S6 into time division multiplexed serial data S7 similar to that shown by the parallel/serial converter 23 in FIG. This serial data S7 is parallelized by a serial/parallel converter 32, and an independent control signal S8a%S8d
, S 9 a - S 9 d. At this time, the timing pulse generator 33 outputs the serial data S7.
A clock signal and a timing signal are extracted from the output signal and sent to the serial/parallel converter 32 and the control signal storage circuit 12.

The control signal storage circuit 12 stores each control signal 58a-38d, 5 extracted by the serial/parallel converter 32 based on the timing pulse sent from the timing pulse generator 33.
9a-89d.

The outputs 510a and 510d of the control signal storage circuit 12 are control signals for setting the recording current of each channel, and are converted into analog voltages by D/A in the control signal storage circuit 12. These are channel recording/playback switching control signals.51 of these control signals
0a and 5lla are connected to the signal processing circuit 10a shown in FIG. 2, 5IOb and 5llb are connected to the signal processing circuit FI@I Ob,
510c and 5llc are in the signal processing circuit 10c, 510d
and 5lld are sent to the signal processing day R10d, respectively, to control the operation of each signal processing circuit 10a to 10d.

According to such a configuration, the control signal can be transmitted via the rotary coupling means that transmits the recording signal and the reproduction signal during the format dropout period, so that the control signal can be transmitted without causing any interference to the recording signal or the reproduction signal. , signal processing day F#110a~ on the rotating drum 1 from outside the rotating drum 1
A wide variety of controls can be performed on 10d.

Moreover, by using the rotary coupling means for both recording and playback signal transmission and control signal transmission, the number of parts can be reduced, making it easier to make equipment smaller, lighter, and simpler, and reducing man-hours. Because it can be done, it is very advantageous in terms of price.

Note that the present invention is not limited to the above-mentioned embodiments, and can be implemented with various modifications without changing the gist. Although an example in which the present invention is applied to is shown, the present invention can also be applied to a transverse scan type magnetic recording/reproducing device. Furthermore, in the above embodiment, a rotary transformer is used as a rotary coupling means for transmitting and receiving recording and reproduction signals between the signal processing circuit on the rotating drum and the circuit on the fixed side, but a slip ring or an optical coupler may also be used. I don't mind.

[Effects of the Invention] As described above, according to the configuration of the present invention, a wide variety of control signals can be transmitted from outside the rotating drum to the signal processing circuit on the rotating drum without providing a special transmission line exclusively for control signals. Since recording and playback signals can be transmitted without any interference, it is possible to mount various signal processing circuits, including recording amplifiers and playback amplifiers, on the rotating drum, enabling wideband, high-density recording. It is possible to significantly improve the performance of the device, and it is also possible to make the device smaller, have more channels, and have more functions.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing a rotating drum section of a magnetic recording/reproducing apparatus according to the present invention, FIG. 2 is a circuit configuration diagram showing an embodiment of the present invention, and FIGS. 3 and 4 are diagrams showing the same embodiment. FIGS. 5 and 6 are circuit configuration diagrams embodying different main parts of the examples, respectively, and are circuit configuration diagrams illustrating different conventional recording/reproducing apparatuses. 1...Rotating drum 2a-2d...Magnetic head for both recording and reproduction 7...Tape 8...Format dropout period 10a-10
d... Signal processing circuit 11... Control signal receiving circuit 12... Control signal storage circuits 13a to 13d... Rotary transformer 14... Switching circuit 15... Electric circuit 16... Control signal transmission Circuit diagram 1 diagram 2

Claims (1)

[Claims] A magnetic recording medium wound around a rotating drum over a predetermined angle range is used to record or reproduce at least a signal using a magnetic transducer installed on the rotating drum, and the rotating drum and this drum are connected to each other. A magnetic recording and reproducing device in which at least a recorded signal or a reproduced signal is transmitted between supporting fixed parts by a rotary coupling means, comprising: a signal processing circuit for processing at least one of the recording signal or the reproduced signal on the rotary drum; A fixed part that supports the rotating drum, further comprising a control signal receiving circuit for receiving a control signal for controlling the operation of the circuit from the rotation coupling means, and a control signal storage circuit for storing the control signal received by the control signal receiving circuit. A control signal transmitting circuit is provided on the side, and a control signal is transmitted from the control signal transmitting circuit to the control signal receiving circuit via the rotational coupling means during a period when the magnetic transducer is not in contact with the magnetic recording medium. A magnetic recording/reproducing device characterized by being provided with a transmission means.