JPS62236103A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To execute the recording and reproducing of a high quality signal by connecting a coil as the load of a recording amplifier to supply a recording signal to a primary side of a recording system output transformer, raising the high area of the frequency characteristic of a recording electric current and obtaining a flat frequency characteristic over all recording bands. CONSTITUTION:At the time of a wide band recording action mode to close one side switch 5 and open other switch 7, by opening the switch 7, a variable resistance 6 to give a damping characteristic at the time of the recording action mode is usually separated from a recording system, the frequency characteristic of the recording system is set by the parallel circuit of a variable resistance 3 and a coil 4 and the recording action is executed. The parallel circuit of the variable resistance 3 and the coil 4 is operated so that the variable resistance 3 can give the damping characteristic and the coil 4 can raise the high area of the frequency characteristic and gives the flat frequency characteristic to the recording system over all recording bands. Thus, the signal with a high quality can be recorded and reproduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a magnetic recording and reproducing device such as a video tape recorder that transmits and receives recording signals and reproduced signals via a rotary transformer, and particularly relates to a magnetic recording and reproducing device such as a video tape recorder that transmits and receives recording signals and reproduced signals via a rotary transformer. Short-circuit switches are provided on the primary side and the secondary side of the input transformer of the reproduction system, respectively, and the secondary coil of the output transformer of the recording system, the primary coil of the input transformer of the reproduction system, and the rotary coil of the electric-magnetic-electric conversion system are provided. The present invention relates to a magnetic recording and reproducing device in which fixed coils of a transformer are connected in series and recording operation and reproducing operation are switched by controlling the reciprocal operation of each shorting switch.

[Summary of the invention]

The present invention provides a short circuit switch on the primary side of the output transformer of the recording system and on the secondary side of the input transformer of the reproduction system, so that the secondary coil of the output transformer of the recording system and the primary coil of the input transformer of the reproduction system are connected. Rotor IJ of an electric-magnetic-electric conversion system) In a magnetic recording/reproducing apparatus in which the fixed side coils of the lance are connected in series and the recording operation and reproducing operation are switched by reciprocal operation control of each shorting switch, the above-mentioned recording By connecting a coil as the load of the recording amplifier that supplies the recording signal to the primary side of the output transformer of the system, it is possible to widen the band of the recording system without changing the impedance characteristics of the electric-magnetic-electric conversion system seen from the reproduction system side. It was designed to achieve this.

[Conventional technology]

Conventionally, in a video tape recorder (VTR), a video signal is supplied from a recording processing system to a video head via a rotary transformer and recorded on an inclined recording trunk on a magnetic tape. It is widely known that a so-called rotary magnetic recording system is adopted in which a reproduced signal obtained by tracing is supplied to a reproduction processing system via a rotary transformer. Furthermore, a ferrite head is generally used as the video head.

As a VTR employing the above-mentioned rotating magnetic recording method, one having a configuration as shown in the circuit diagram of FIG. 3, for example, is known.

In the conventional example shown in FIG. 3, a recording amplifier 32 that amplifies a frequency-modulated luminance signal supplied from a signal input terminal 31 as a recording signal has an output terminal connected to a primary coil 38 of an output transformer 37. The recording signal is about to be outputted via this output transformer 37.

The output transformer 37 of the recording system has a secondary coil 38.
The center tap is connected to the power supply terminal 35 and grounded via a capacitor 36, and both ends of the above-mentioned secondary coil 38 are connected via a variable resistor 33 and a short circuit switch 34 is connected. It is designed to be shorted through. Further, in the output transformer 37, one end of the secondary coil 39 is connected to one end of the fixed side coil 41 of the rotary transformer 40, and the other end of the secondary coil 39 is connected to the input transformer 50 of the regeneration system. It is connected to one end of the stationary coil 41 of the rotary transformer 40 via the primary coil 51 .

The rotary transformer 40 is connected to the rotary coil 42 side thereof with a video controller 45 for both recording and reproducing purposes, which traces recording tracks on the magnetic tape 47.

Further, the input transformer 50 of the regeneration system has one end of its secondary coil 52 connected to the signal output terminal 5 via the regeneration amplifier 54.
5, the other end of the secondary coil 52 is grounded, and both ends of the secondary coil 52 are short-circuited via a short-circuit switch 53.

A VTR configured as described above has a recording system output transformer 38.
By opening the short-circuit switch 34 provided on the primary side and closing the short-circuit switch 53 provided on the secondary side of the input transformer 51 of the reproduction system, a recording operation state is entered, and the recording supplied to the signal input transformer 31 is activated. The signal is amplified by the recording amplifier 32 and transferred from the output transformer 37 to the rotary transformer 40.
The video signal can be supplied to the video head 45 via the video head 45 and recorded on the magnetic tape 47. Conversely, by closing the recording system short-circuit switch 34 and closing the reproduction system short-circuit switch 54, a reproduction operation state is entered, and the reproduction signal is reproduced from the magnetic tape 47 by the video controller 45. is supplied from the rotary transformer 40 to the regenerative amplifier 54 via the input transformer 50, and the regenerative signal can be amplified by the regenerative amplifier 54 and output from the signal output terminal 55.

Here, the variable resistor 33 provided on the primary side of the output transformer 37 of the recording system is for adjusting the frequency characteristics of the recording system, and damps the resonance characteristics of the recording system as shown in FIG. In this way, frequency characteristics corresponding to the electric-magnetic-electrical conversion characteristics of the ferrite head used as the video head 47 are obtained. for example,
In the above conventional example, the resonant frequency fo of the recording system is 8MH.
This is damped by the variable resistor 33 and recorded with a slope of about 2MH2:8MH2=2:l.

Note that the ferrite head used as the video head 45 has an electric-magnetic-electrical conversion characteristic that deteriorates in a high frequency range, so for example, the operating frequency band required for recording and reproducing color video signals including telefrequency components is limited. Improvements have been made in the past to ensure this.

In addition, progress is being made in improving magnetic recording media, and iron oxide (iron oxide)
Various magnetic tapes have been provided, such as T-Fe2O2)-based tapes, Co-iron oxide-based tapes, and metal tapes using ferromagnetic metal powders with high coercive force. As magnetic heads that enable high-density recording using metal tapes with high coercive force, we have developed amorphous heads and sendust heads that use amorphous metals and sendust that have good electro-magnetic conversion characteristics up to high frequency ranges. etc. are provided.

[Problem that the invention seeks to solve]

-m, in a magnetic recording/reproducing device, such as a video tape recorder, which transmits a frequency-modulated luminance signal via an electric-magnetic-electrical conversion system, the problem is caused by distortion of the electric-magnetic-electrical conversion system. It is known that in order to reduce the so-called overmodulation phenomenon, in which the frequency modulated signal cannot be properly demodulated in the reproduction system, it is sufficient to use a recording system that has flat frequency characteristics over a wide band. There is.

However, as mentioned above, a short-circuit switch is provided on the primary side of the output transformer of the recording system and the secondary side of the input transformer of the reproduction system, so that the secondary coil of the output transformer of the recording system and the primary coil of the input transformer of the reproduction system are provided. A magnetic recording/reproducing device connects a coil and the primary coil of a rotary transformer of an electric-magnetic-electrical conversion system in series, and switches between recording and reproducing operations by controlling the reciprocal operation of each shorting switch. In order to ensure flat frequency characteristics across the board, changing the turns ratio of the output transformer in the recording system to raise the resonance frequency will lower the resonance frequency during playback operation, so the turns ratio of the input transformer in the playback system should also be changed. Must be changed. In this case, the turns ratio of the input transformer of the reproduction system is reduced, resulting in a poor S/N ratio.

Therefore, in view of the above-mentioned conventional problems, the present invention provides a short circuit switch on the primary side of the output transformer of the recording system and the secondary side of the input transformer of the reproduction system. The coil, the primary coil of the input transformer of the reproduction system, and the primary coil of the rotary transformer of the electric-magnetic-electric conversion system are connected in series, and recording operation and reproduction operation are switched by reciprocal operation control of each shorting switch. In the magnetic recording/reproducing device, we achieved a wide band recording system and improved the overmodulation characteristics without degrading the S/N ratio of the reproduction output obtained by the reproduction system, and recorded extremely high quality signals. The purpose is to enable regeneration.

[Means for solving problems]

In order to achieve the above-mentioned object, the present invention provides a short circuit switch on the primary side of the output transformer of the recording system and the secondary side of the input transformer of the reproduction system, and connects the secondary coil of the output transformer of the recording system with the A magnetic recording system in which the primary coil of the input transformer for the playback system and the primary coil of the rotary transformer for the electric-magnetic-electric conversion system are connected in series, and the recording operation and playback operation are switched by reciprocal operation control of each shorting switch. In the playback device, a coil is connected as a load of the recording amplifier that supplies the recording signal to the primary side of the output transformer of the recording system, and the high range of the frequency characteristic of the recording current is raised to maintain a flat frequency over the entire recording band. It is characterized by the fact that it has certain characteristics.

[Effect]

In the magnetic recording and reproducing apparatus according to the present invention, the frequency of the recording current is increased by the coil connected as a load of the recording amplifier that supplies the recording signal to the primary side of the output transformer of the recording system, without changing the impedance characteristics seen from the reproduction system. A flat frequency characteristic is obtained over the entire recording band by increasing the high frequency range of the characteristic, and a signal is recorded in a wideband recording system and reproduced in the above-mentioned reproduction system.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a magnetic recording and reproducing apparatus according to the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a circuit diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a characteristic diagram showing the recording operation characteristics of the above embodiment.

In the embodiment shown in FIG. 1, a frequency-modulated luminance signal is supplied to the signal input terminal 1 as a recording signal.

The recording amplifier 2 that amplifies this recording signal has its output end connected to the primary coil 11 of the output transformer 11.
A recording signal is outputted via the output transformer 11.

The output transformer 11 of the recording system has a secondary coil 12.
The center tap of is connected to the power terminal 9, and
It is grounded via a capacitor 10, and furthermore, between both ends of the secondary coil 12 are connected a parallel circuit of the variable resistor 3 and the coil 4, a series circuit of the switch 5, a series circuit of the variable resistor 6 and the switch 7, and a short circuit. They are connected via switch 8.

Further, in the output transformer 11, one end of the secondary coil 13 is connected to one end of the fixed side coil 16 of the rotary transformer 15, and the other end of the secondary coil 13 is connected to the input transformer 20 of the regeneration system. It is connected to one end of the stationary coil 16 of the rotary transformer 15 via the primary coil 21 .

The rotary transformer 15 is connected to the rotating coil 17 side thereof with a video head 18 for both recording and reproducing purposes, which traces recording tracks on the magnetic tape 19. As the video head 18, an amorphous head or the like having good electric-magnetic-electrical conversion characteristics up to high frequencies is used.

Further, the input transformer 20 of the regeneration system has one end of its secondary coil 22 connected to the signal output terminal 2 through the regeneration amplifier 24.
5, and the other end of the secondary coil 22 is grounded, and both ends of the secondary coil 22 are short-circuited via a short-circuit switch 23.

In the embodiment configured as described above, the shorting switches 7 and 23 provided on the primary side of the output transformer 10 of the recording system and the secondary side of the input transformer 21 of the reproducing system are set reciprocally in conjunction with the operation mode. The operation is controlled, and in the recording operation mode, the recording system short-circuit switch 8 is opened and the reproduction system short-circuit switch 23 is closed, and in the reproduction operation mode, the recording system short-circuit switch 8 is closed, and the reproduction system is closed. The short circuit switch 23 of the system is closed.

Furthermore, the respective switches 5, 7 provided in the recording system are controlled to operate reciprocally in conjunction with the switching of the recording mode, and in the normal recording operation mode, one switch 5 is opened and the other switch 7 is closed. In contrast, one switch 5 is closed and the other switch 7 is opened in the broadband recording operation mode.

Therefore, in the embodiment with the above-described configuration, in the normal recording operation mode in which one of the switches 5 is opened and the other switch 7 is closed, the variable resistor 3 and the coil 4 are connected in parallel by opening the switch 5. The circuit is separated from the recording system, and the variable resistor 6 connected in series with the switch 7 provides damping characteristics similar to those of the conventional example shown in FIG. 4, and recording operation is performed.

In addition, during the broadband recording operation mode in which one switch 5 is closed and the other switch 7 is opened, opening the switch 7 causes the variable resistor 6 to provide the damping characteristics during the normal recording operation mode. It is separated from the system, the frequency characteristics of the recording system are set by the parallel circuit of the variable resistor 3 and the coil 4, and a recording operation is performed. In the parallel circuit of the variable resistor 3 and the coil 4, the variable resistor 3 provides damping characteristics, and the coil 4 acts to increase the high range of the frequency characteristics, so that, for example, as shown in FIG. To provide a recording system with flat frequency characteristics over a band.

As in this embodiment, if the coil 4 for frequency characteristic adjustment is connected in parallel to the primary coil 12 of the output transformer 11 without changing the turns ratio of the output transformer 11 of the recording system, it is possible to By increasing the high frequency characteristics of the recording system without changing the impedance characteristics, flat frequency characteristics are obtained over the entire recording band, and the S/N ratio of the reproduction output obtained by the reproduction system is degraded. The recording system can be made to have a high bandwidth and the overmodulation characteristics can be improved without any problems, and the recording system can be made to have a high bandwidth and the overmodulation characteristics can be improved. Signals can be recorded and played back.

〔Effect of the invention〕

As is clear from the description of the above-mentioned embodiments, according to the present invention, short-circuiting switches are provided on the primary side of the output transformer of the recording system and on the secondary side of the input transformer of the reproduction system, so that the output of the recording system The secondary coil of the transformer, the primary coil of the input transformer of the playback system, and the primary coil of the rotary transformer of the electric-magnetic-electric conversion system are connected in series, and recording and playback operations are performed by reciprocal operation control of each shorting switch. In a magnetic recording/reproducing device that switches the recording current, a coil connected as a load of the recording amplifier that supplies the recording signal to the primary side of the output transformer of the recording system can change the recording current without changing the impedance characteristics seen from the reproduction system. Since the high frequency characteristics are raised and flat frequency characteristics are obtained over the entire recording band, the S of the reproduction output obtained from the reproduction system is
It is possible to widen the band of the recording system and improve overmodulation characteristics without deteriorating the /N ratio, and it is possible to record and reproduce extremely high quality signals.

[Brief explanation of drawings]

FIG. 1 is a circuit diagram showing an embodiment of a magnetic recording/reproducing apparatus according to the present invention, and FIG. 2 is a characteristic diagram showing the recording operation characteristics of the above embodiment. FIG. 3 is a circuit diagram showing a conventional example of a magnetic recording/reproducing device, and FIG. 4 is a characteristic line diagram showing recording operation characteristics of the above-mentioned conventional example. 1... Signal input terminal 2... Recording amplifier 3.6.
...Variable resistance 4...Coil 5.7...Switch 8.23... -Short thread each switch 11...Output transformer 15...Rotary transformer 18...Video connection 19...Magnetic Tape 20・
...Input transformer 24...Regeneration booster 25...Signal output terminal

Claims (1)

[Claims] Short circuit switches are provided on the primary side of the output transformer of the recording system and on the secondary side of the input transformer of the reproduction system, and the secondary coil of the output transformer of the recording system and the primary of the input transformer of the reproduction system are provided. In a magnetic recording/reproducing device in which a coil and a primary coil of a rotary transformer of an electric-magnetic-electrical conversion system are connected in series, and recording operation and reproducing operation are switched by reciprocal operation control of each shorting switch, the above-mentioned recording system is provided. A coil is connected as the load of the recording amplifier that supplies the recording signal to the primary side of the output transformer, and the high range of the frequency characteristic of the recording current is increased to obtain a flat frequency characteristic over the entire recording band. A magnetic recording/reproducing device characterized by: