JPS6030003B2 - Signal recording method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a signal recording method, in which recording is performed by dividing a recording signal according to its frequency band and supplying the divided signals to a pair of gaps each having a different cross-sectional area of a single magnetic head. Conduct,
An object of the present invention is to provide a signal recording method capable of recording with high fidelity.

Conventional signal recording methods typically record recorded signals such as audio signals on magnetic tape using a gap in the core of a magnetic head. In order to obtain good multi-band signal characteristics, the above-mentioned gap must be made small. However, a small gap size causes manufacturing technology difficulties and a reduction in playback sensitivity, and even if the best technology to date is used, the relative speed of the magnetic head and magnetic tape is 1 node/min. In the case of low-speed recording on the order of seconds, the upper limit of the recording frequency characteristics is as low as approximately 5kHz.
Upper limit frequency required for faithful reproduction of audio signals, etc. 1ok
The drawback was that it was impossible to record at or above HZ.

Therefore, it is an object of the present invention to provide a signal recording method in which a magnetic head has a normal gap, and can particularly record high-frequency band signals particularly well in cooperation with a circuit attached to the head. . 1 and 2 are a plan view showing a schematic configuration of a magnetic head applied to one embodiment of the signal recording system according to the present invention, and an enlarged partial plan view showing a tape attached state in the gap portion thereof, respectively. .

In each figure, 1 is a magnetic head, and its core 2 is made by joining a pair of core halves 3, 32, each made of a magnetic material such as ferrite or permalloy, into a C-shape. A relatively large-shaped magnetic plate 4 such as ferrite or permalloy is inserted into the tip gap to form a pair of first and second magnetic plates.
gaps 5 and 6 are formed. In particular, the gap forming surface of the core half body 3 is formed by integrally bonding a magnetic core portion 3a, which is made of the same material as the core half body 3 and has the same shape as the magnetic plate 4, to the core half body 3 in advance. ing. Therefore, magnetic plate 4
As shown in FIG. 2, the first and second gaps 5 and 6 are spaced apart from each other to face the distal end surface 3b of the magnetic core portion 3a and the core half body 32 through a non-magnetic material 7 such as glass filled in the first and second gaps 5 and 6, respectively. However, since the gap depth dimension of the magnetic plate 4 is more than three times that of the tip surface 3b (the dimensions in this gap are each about 0.5r), the magnetic The road cross section is three times or more larger than that of the second gap 6. 8 has coil terminals 8a and 8b which are wound around the core half 3 in FIG. 1 and connected to a circuit 101 which will be described later.

The coil 9 is similarly wound around the core half 32 and has coil terminals 9a and 9b. In the circuit 101 shown in FIG. 3, the audio signal supplied to the input terminal 11 is
(Automatic gain control) After being subjected to desired signal processing in a recording signal processing circuit 12 including a circuit intensifier, an equalizer circuit, etc., the signals are supplied to a low-frequency wave generator 13 and a high-frequency wave generator 15, respectively.

The low frequency band signal passed through the low frequency wave generator 13 and generated at a predetermined cutoff frequency is superimposed with a deep high frequency bias current supplied from the bias circuit 14 and sent to the coil terminals 9a, 9b.
is supplied to the coil 9 via. On the other hand, Takagi Rowaki 15
The high frequency band signal which has been subjected to waveforming at a predetermined cut-off frequency is amplified by an amplifier 21 with a desired gain.

Although the function of this intensifier 21 will be described later, the intensifier 21 is not necessarily necessary, and is configured so that an equalizer circuit constituting the recording signal processing circuit 12 emphasizes the high-frequency band signal. It's okay. Subsequently, the increased high frequency band signal is delayed for a predetermined time by the delay circuit 22, and then supplied to the coil 8 via the coil terminals 8a, 8b in a non-biased state. When the coils 8 and 9 are energized, the magnetic flux passes through a magnetic path consisting of the core half 3, the first gap 5, the magnetic plate 4, the second gap 6, and the core half 32 in FIG. At this time, the first and second gaps 5
, 6 and the vicinity thereof, the distribution and generation direction of the magnetic flux 24 are as shown by the dotted line in FIG. In FIG. 2, if we first focus on the magnetic flux caused by the high-frequency bias current from the bias circuit 14, the frequency is usually 50 to 200 kHz, and the magnetic flux density is sparse in the first gap 5 and sparse in the second gap, as shown in the figure. It is relatively dense in gap 6, and is inversely proportional to the magnetic path cross-sectional area of gaps 5 and 6, respectively.
As mentioned above, since the gap cross-sectional area of the first gap 5 is three times or more that of the second gap 6, the magnetic flux density ratio is also three times or more.

Therefore, as shown in the figure, the magnetic flux 24a generated in front of the first gap 5 by the high frequency bias current magnetizes a relatively shallow portion of the magnetic layer 23a. Further, the magnetic flux 24b generated in front of the second gap 6 is relatively large and magnetizes the magnetic layer 23a to a deep portion. Thus, the recording signal is generated in the second gap 6 based on the deep high frequency bias current.
By using the first gap 5, recording is performed with a deeper bias, and recording with a shallower bias is performed with the first gap 5. Next, paying attention to the recording signal, in the first gap 5, the coil 8
A high frequency band signal supplied with no bias is recorded with a shallow bias as described above.

The level of the high frequency band signal supplied to the coil 81 is set to be higher than the level of the low frequency band signal by the high frequency bias method which is amplified by the above-mentioned intensifier and supplied to the coil 9, thereby compensating for various losses during recording as known in the art. In addition, especially when the magnetic flux density for recording is small due to the sparse magnetic flux density of the first gap 5 as described above, this is compensated for. Therefore, in the first gap 5, due to the shallow bias method in the first gap 5, recording can be performed satisfactorily without producing the demagnetizing effect, which will be described later. second gap 6
In this case, the low frequency band signal supplied from the coil 9 is recorded. In this case, the low frequency band signal superimposed on the deep high frequency bias current as described above enters the coil 9, but the level of the low frequency band signal is set in advance to be relatively 4. Therefore, the low frequency band signal is recorded in the second gap 6 where the magnetic flux density is high, but not in the first gap 5 where the magnetic flux density is low. The reason why only the low frequency band signal is recorded in the second gap 6 and the high frequency band signal is not recorded is that if the recording signal is recorded using the normal deep high frequency bias method as in the case of the second gap 6, This is because the high frequency band signal of the recording signal is demagnetized, making it impossible to record.

This is thought to be because the higher the signal frequency of the recording signal is, the more the surface portion of the magnetic layer 23a of the magnetic tape 23 is used, so the demagnetization effect becomes more effective. It is known that demagnetization largely depends on the magnitude of the bias current, and the larger the bias current, the greater the demagnetization. Here, a pair of gaps 5, 6
Therefore, if the high frequency band signal and the low frequency band signal are simultaneously recorded on the magnetic tape 23, a recording position error will occur between the two signals on the tape 23. However, in reality, the magnetic plate It has been confirmed that if the thickness of the gap 4 is sufficiently thin, the delay time between the gaps 5 and 6 becomes, for example, 3 seconds or less, which poses no problem in practice.

However, in this embodiment, the above-mentioned disadvantage is eliminated by the delay circuit 22. That is, as shown in FIG. 3, after the low frequency band signal of the recording signal is recorded on the magnetic tape 23 with a deep bias by the second gap 6, the high frequency band signal is transferred to the delay circuit by the first gap 5. 2
2, the signal is instantaneously delayed and recorded with a shallow bias on the same track as the recorded low frequency band signal. Thus, the audio signal is first divided into a high frequency band and a low frequency band at a predetermined crossover frequency, and then the low frequency band signal is recorded with a normal deep bias by the second gap 6, and the first gap 5 As a result, high-frequency band signals are recorded with a shallow bias,
This eliminates the disadvantage that the signal level of high frequency band signals is reduced due to the condensation effect caused by deep high bias currents.
When reproducing the signal recorded on the magnetic tape 23, a commonly used reproducing magnetic head composed of a single magnetic gap may be used, or a reproducing magnetic head composed of a single magnetic gap may be used. The reproduced signal may be extracted from the coil 9 using the following.

Further, in the above embodiment, a pair of gaps 5 and 6 are formed by one magnetic plate 4, but the invention is not limited to this, and three or more gaps may be formed by two or more magnetic plates. It is also possible to have a configuration in which more than one coil is wound.

As described above, according to the signal recording method of the present invention, at least one pair of gaps with equal gap dimensions are formed by interposing the gap magnetic plate at the tip end of the core, and each gap has a cross-sectional area in the direction of magnetic path formation. A magnetic head is formed by making the magnetic flux densities different from each other and winding coils corresponding to the respective gaps around the core, and dividing the recorded signal at a predetermined crossover frequency to generate a high frequency band signal and a known frequency signal. dividing means for dividing the low-frequency band signal into band signals; supply means for supplying the low-frequency band signal to a coil corresponding to the gap with a small cross-sectional area using a predetermined high-frequency bias method; The high-frequency bias current of the high-frequency bias method is used to supply high-density and low-density coils to the gaps with small and large cross-sectional areas, respectively. Since magnetic flux is generated to produce the effects of deep bias recording and shallow bias recording, respectively, the low frequency band signal and high frequency band signal divided by the above dividing means each have a cross-sectional area of 4.
・And the large gap enables good recording with the deep via and shallow bias, respectively, eliminating the disadvantages such as signal level drop due to demagnetization effect when recording high frequency signals with deep bias. For example, even when the relative speed between the magnetic head and the magnetic tape is small, it is possible to record particularly high-frequency band signals, and it is possible to reduce the tape speed, perform long-time recording based on this, and perform high-fidelity recording. In addition, the gap can be maintained as usual, and the structure is simple and easy to manufacture, as it is a structure that only requires adding a magnetic plate to a normal magnetic head. It has the features of being extremely practical as it has the functions of two heads with the structure of approximately one head.

[Brief explanation of the drawing]

FIG. 1 and FIG. 2 each show one of the signal recording methods according to the present invention.
A plan view showing a schematic configuration of a magnetic head obtained by applying the embodiment, and an enlarged partial plan view showing a state in which a tape is attached to the gap portion thereof, and FIG. 3 is a block of an external circuit connected to the magnetic head. It is a system diagram. 1...Magnetic head, 2...Core, 3. ,3
2... Core half, 3a... Magnetic core part, 4... Magnetic plate, 5, 6... Gap, 8, 9
... Coil, 8a, 8b, 9a, 9b ... Coil terminal, 10 ... External circuit, 12 ... Recording signal processing circuit, 13 ... Low range furnace Wave equipment, 14...
...Bias circuit, 15...Takagi Resonator,
21... Multiplier, 22... Delay circuit,
23...magnetic tape. Figure 1 Figure 2 Figure 3

Claims (1)

[Claims] 1 A magnetic plate is interposed in the gap at the end of the core to form at least one pair of gaps having the same gap width, and each gap has a different cross-sectional area in the magnetic path forming direction to make the magnetic flux densities different from each other. a magnetic head formed by winding a coil corresponding to each gap around a core; a dividing means for dividing the recorded signal at a predetermined crossover frequency into a high frequency band signal and a low frequency band signal; and the low frequency band. supply means for supplying a signal to the coil corresponding to the gap with a small area using a predetermined high frequency bias method; and supply means for supplying the high frequency band signal without bias to the coil corresponding to the gap with a large cross-sectional area. A signal recording method characterized by comprising: