JPS6029053Y2 - Magnetic tape transfer device - Google Patents

Description

[Detailed explanation of the invention] This invention is based on recorded original tape (hereinafter referred to as master tape).
and unrecorded transfer tape (hereinafter referred to as slave tape)
In a device that transfers signals from a master tape to a slave tape by applying a transfer bias such as a magnetic field or heat from the outside with their magnetic surfaces in close contact with each other, the master tape transfers video and audio signals on different tracks. When a signal is recorded, only the video signal is transferred by the contact transfer method, the audio signal is reproduced by a separate head, and the audio signal is recorded onto the slave tape by another head. The present invention relates to an improvement in a transfer device that enables good copying of signals.

Generally, the signal voltage reproduced from a master tape is proportional to the signal frequency.

That is, in an imaginary state where the loss is zero, the frequency characteristics will rise in the octave a.

However, in reality, cap loss, gap loss, angular misalignment loss, etc. occur, and in addition, eddy current loss occurs because the transfer device performs audio copying at high speed.

Similarly, recording demagnetization loss occurs in the slave tape recording head.
In addition to self-demagnetization losses, the signal frequency becomes extremely high because copying is performed at high speed, similar to the above-mentioned reproducing head, and a large amount of eddy current loss occurs.

That is, in the copying apparatus, the high frequency characteristics of the reproduction/recording characteristics of the audio signal deteriorate as shown in FIG.

In order to correct this, a correction circuit having characteristics opposite to those shown in FIG. 1 may be inserted between the reproducing head and the recording head.

However, in a copying machine, if the tape speed when copying the audio signal is constant, the error in the correction circuit will only affect the audio signal frequency characteristics of the slave tape, but if the tape speed is not constant, the level will fluctuate. .

In other words, the tape speed when recording the master tape is 33.3.
mm/sec, and in this case, if the tape speed of the copying machine is 1.5 m/Sec, the tape speed difference will be six times, resulting in a signal of 450 KHz.

However, the tape speed of the copying machine fluctuated, and the tape speed decreased to 1.7 m/s.
ec, the signal will be approximately 510 KHz.

However, as shown in the reproduction/recording characteristics of FIG. 1, the downward slope becomes steeper at higher frequencies, and unless very precise correction is made, there will be differences in copying efficiency and level fluctuations.

By the way, recently, video recording and reproducing devices (hereinafter referred to as VTRs)
With the increase in density, the tape speed has become slower, and a system has been adopted in which the tape speed can be switched and the recording/playback time can be extended using a single VTR.

On the other hand, in recent VTRs, a tape width of 172 inches (12.75 cm) is mainly used, and the audio track position and track width are considered to be almost the same across various systems.

When considered as a transfer device, this means that various types of magnetic tapes can be transferred using the same device.

In other words, since video signals are transferred using the contact transfer method and audio signals are recorded using a magnetic head, once recorded master tapes of various methods are prepared, the transfer device can:
Transfer can be performed using exactly the same device.

However, although the audio signal is copied at a high tape speed as described above, the frequency band of the audio reproduction signal from the recorded master tape required for various types of VTRs varies considerably.

Furthermore, as explained above, frequency correction of the reproduced signal requires very delicate adjustment.

Providing correction circuits for each of these various recorded master tapes would make the audio circuit extremely complicated and require a great deal of effort for adjustment.

The present invention eliminates these drawbacks and furthermore proposes a method that allows slave tapes of various types to be created using the same transfer device.

Hereinafter, details of the present invention will be explained with reference to drawings showing embodiments.

In Figures 2 and 3, 1 is the recorded master tape 2.
The supply reel 1 is a supply reel wound with a motor 3.
6.

Reference numeral 3 denotes a supply reel on which an unrecorded slave tape 4 is wound, and the supply reel 3 is driven by a motor 37.

Reference numeral 5 denotes an air column for controlling the tension of the master tape 2, which sucks the master tape 2 from a vacuum source (not shown) via an air suction lower.

9 is a light emitting element, 10 is a light receiving element, which detects the tape loop position in the air column 5, and via the control circuit 41,
The motor 36 is controlled to keep the tape loop position in the air column 5 constant, and the tension of the master tape 2 is always kept constant.

Reference numeral 6 denotes an air column for controlling the tension of the slave tape 4, which, like the master tape 2, is composed of a light emitting element 11, a light receiving element 12, and an air suction port 8, and keeps the tension of the slave tape 4 constant at all times. There is.

Note that each tension is determined by the air pressure of the vacuum source.

A take-up reel 13 winds up the master tape 2 and slave tape 4 with their magnetic surfaces in close contact with each other.

The take-up reel 13 is driven by a motor 38, and a gear 39 and a magnetic head 40 mounted coaxially with the motor 38 generate a frequency proportional to the number of rotations of the motor 38.

The signal controls the motor 38 via the control circuit 43.

To explain in more detail with reference to FIG. 5, the signal obtained from the magnetic head 40 is transmitted to the comparator 4 via the amplifier
5.

48 to 51 are oscillators that oscillate frequencies f1 to f4, respectively, and one of them is selected by the changeover switch 47 and supplied to the comparator 45.

The output of comparator 45 drives motor 38 via power amplifier 46.

That is, when the change-over switch 47 selects the oscillator 48, the motor 38 is controlled so that the signal frequency obtained from the magnetic head 40 is also fl, that is, the take-up reel 13 is controlled so as to always rotate at a constant rate. be done.

A transfer bias is applied by the magnetic field generator 18 to both tapes 2 and 4 wound on the take-up reel 13, and the signal of the master tape 2 is transferred to the slave tape 4.

After the transfer is completed, each tape 2, 4 is transferred to the supply reel 1.
Rewind to 3.

When rewinding, the motors 36, 37 .
The direction of rotation of the tape 38 is reversed, ie, the supply reel 1 for the master tape and the supply reel 3 for the slave tape will wind up their respective tapes, and the take-up reel 13 will send out both tapes.

The control of each of the motors 36, 37, and 38 is the same as that for winding described above, and the motors 36, 37 are controlled by the tape position in the air column, and the motor 38 is controlled by the output signal of the magnetic head 40. tape tension,
Tape speed can be kept constant.

During this rewinding, the audio signal of the master tape 2 is reproduced by the reproduction head 23 and recorded by the recording head 25. To be more specific, as shown in FIG. supplied to

As mentioned above, the correction circuit 53 corrects the loss caused by the reproducing head 23 and the recording head 25, and has characteristics opposite to the reproducing/recording properties shown in FIG.

As mentioned above, this characteristic requires precise adjustment.

The signal corrected by the correction circuit 53 is recorded on the slave tape 4 by the recording head 25 via the recording amplifier 54.

A bias oscillator 55 drives the recording bias of the recording head 25 and the erasing current of the erasing head 24.

Generally, the frequency of the bias oscillator 55 is 3 to 5 MHz because the tape speed is fast.

The erasing head 24 is for erasing the audio signal of the slave tape 4 transferred by the transfer bias.

As described above, a good transferred slave tape can be obtained by the transfer device.

That is, the oscillator 48 of the transfer device is adjusted in proportion to the tape speed of the VTR of various types when recording the master tape.
51, the tape speed during audio copying by the transfer device is changed, and the frequency band of the reproducing head 23 obtained from the master tape 2 is always kept constant.

That is, since the correction circuit 53 can be shared,
The configuration of the audio circuit becomes very simple and the effort required for adjustment is reduced.

Note that 26 to 33 are guide rollers for running the tape, and 34 and 35 are position regulating rollers for both tapes 2 and 4.

14 and 15 are pressure rollers for pressing and winding both tapes, and are pressed against the take-up reel 13 by springs 16 and 17, respectively.

19.21 is a light emitting element, 20 and 22 are light receiving elements,
The sensing portions of the respective tapes 2 and 4 are provided for detection and automation.

In the above explanation, the number of revolutions of the take-up reel 13 during audio copying is controlled so that the number of revolutions is kept constant. The tape speed changes.

That is, since the accuracy of the correction circuit 53 is required, it is desirable that the tape speed be constant during audio copying.

Other embodiments are shown in FIGS. 6 and 7.

In FIGS. 2 and 6, 56 is a magnetic head for reproducing control signals from the master tape 2, and the reproduced signals are supplied to a comparator 58 via an amplifier 57.

59 is an oscillator, and the oscillation frequency is also supplied to the comparator 58.

The output of comparator 58 is connected to motor 38 via power amplifier 60.
control.

With the above configuration, the frequency of the control signal of the master tape 2 reproduced by the magnetic head 56 is the same as the oscillation frequency of the oscillator 59, that is, the tape speed during audio copying is constant regardless of the tape winding diameter of the take-up reel 13. It can be done.

Since the control signal is a 30 Hz signal when recording the master tape 2 of any of the various systems, synchronizing with the oscillation frequency of the oscillator 59 during audio copying means that the frequency band of the audio signal is the same for any of the various systems. , the audio signal correction circuit 53 can be shared.

Still another embodiment is shown in FIG.

The circuit configuration is the same as that of the first embodiment, but the gear 39 is mounted coaxially with the position regulating roller 34.

Since the roller 34 is driven by the master tape 2, it generates a signal frequency to the magnetic head 40 in accordance with its rotation.

As explained in the first embodiment, the motor 38 is controlled so that the frequency selected by the changeover switch 47 and the frequency obtained from the magnetic head 40 are synchronized, so that the tape speed remains constant during audio copying.

The roller to which the gear 39 is attached is not limited to 34, but also 26.
- 33.35, or even a pressure roller 14.15.

In the above embodiments, a batch winding method was used as the transfer method, but it is easy to understand that the same applies to a parallel transfer method (parallel running method).

It is also well known that heat is used as a transfer bias in parallel transfer systems and the like.

As described above, the present invention changes the frequency of the audio of the copied tape by switching the tape speed in proportion to the tape speed of the various recording methods in the transcription device during audio copying in the transcription device according to the tape speed of the various recording methods of the master tape. The bands are the same, and the correction circuit required for the audio circuit is the same.
Configuration becomes very easy.

[Brief explanation of drawings]

Fig. 1 is an audio signal magnetic head reproduction/recording characteristic diagram of the transfer device, Fig. 2 is an external diagram of the transfer device for explaining the present invention, and Figs. 3 to 7 are main points of the transfer device according to the present invention. FIG. 1.3... Supply reel, 2... Master tape, 4... Slave tape, 13...
... Take-up reel, 23 ... Playback head, 24
... Erasing head, 25 ... Recording head, 36, 37, 38 ... Motor, 39 ...
...Gear, 40...Magnetic head, 41, 42
．． 43... Control circuit, 44, 46...
Amplifier, 45... Comparator, 47... Changeover switch, 48-51... Oscillator.

Claims (1)

[Scope of utility model registration request] A recorded original tape and an unrecorded transfer tape are placed in close contact with each other with their magnetic surfaces, and a transfer bias is applied to the take-up reel by a winding magnetic field. After the transfer bias is applied, both the front and rear tapes are supplied to each other. In a magnetic tape transfer device that reproduces the audio signal recorded on the audio track of the original tape and re-records it on the transfer tape in the process of rewinding it onto the reel, rotation of the take-up reel during re-recording of the audio signal is performed. a detection means for detecting the number; a comparison means which takes the output of this detection means as a first input and selects one of a plurality of rotation reference frequencies as a second input; A magnetic tape characterized in that the magnetic tape is provided with a control drive means for making the number of rotations of the take-up reel match the selected rotation reference frequency, and is configured to obtain a number of rotations of the take-up reel corresponding to the recording speed of the original tape. Transfer device.