JPS5848208A - Sound recording method to magnetic tape - Google Patents

Abstract

PURPOSE:To execute recording with good quality, by dividing a frequency band of an input sound signal, opposing an iron core of a magnetic head in 1 track width of a magnetic tape, setting air-gap length and air-gap depth of the iron core, and a sound recording bias current, and recording them in parallel. CONSTITUTION:To a track 5 of a magnetic tape 1, iron cores 7, 8 of a magnetic head are opposed, and to a track 6, iron cores 9, 10 are opposed and placed. Air-gap length of the iron cores 7, 10 is set longer than air-gap length of the iron cores 8, 9, and also air-gap depth of the iron cores 7, 10 is set shorter than air-gap depth of the iron cores 8, 9. To input terminals Ti1, Ti2 of a recording amplifier 11, signals of the tracks 5, 6 are applied, respectively, and a frequency- divided signal is applied to coils of the iron cores 7-9 together with a bias current given by a sound recording bias oscillator 12. In this way, distortion and a frequency characteristic can be improved as a whole. Also, drop of a reproducing level can be reduced by selecting the width of the iron cores 7-9.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for recording a ringing sound on a magnetic tape that can be used in a device that records an uninvented line audio signal on a magnetic tape.

The relationship between the magnetic tape 6 magnetic heads and the iron core in Suzune machines that record audio signals on magnetic tape, such as conventional cassette tape recorders, open reel tape recorders, and 4-microphone cassette tape recorders, is as shown in Figure 1. Full-band recording is performed on each track using a magnetic head 3 in which iron cores 2 having a width equal to one track width filled with fi are juxtaposed. The track arrangement varies depending on the type of tape recorder, but FIG. 1 shows an example of a four-track, two-channel stereo sound system, in which the gaps between the iron cores 2 of the four magnetic expansion heads 3 are used.

However, if one iron core corresponds to one track of a magnetic tape, and the entire band is to be recorded on one track, the bell bias current should be set to a value that minimizes distortion with a reference level signal of 400 Hs + 1, or 315 Hz. As a result, there is a problem in that overbiasing occurs for signals of several kilohertz or more, leading to deterioration of frequency characteristics. For this reason, when emphasis is placed on frequency characteristics, the optimum bell sound bias that produces the lowest distortion is often ignored, and the sound bias current value is often set so that the width of the frequency response is as wide as possible within a predetermined distortion. . If the bell bias current value is set in this way, the distortion in the pregnant region will naturally worsen.

As mentioned above, in the conventional case, the optimal bell tone bias current value determined from distortion and the ninth Q tone bias current value that widens the frequency characteristics do not match, and it is important to minimize distortion and widen the frequency characteristics. There was a drawback that it was impossible to satisfy both Jin and Jin at the same time.

Previously, since the length of the air gap in the iron core of the magnetic head was adjusted to the short wavelength of the recording signal, there was a drawback that distortion increased when the signal current was large and a long wavelength signal was recorded.

The present invention has been made in view of the above, and an object of the present invention is to provide a method for attaching bells to a magnetic tape, which eliminates the above-mentioned drawbacks.

The present invention will be explained below using examples.

FIGS. 2 and 4 show 7'? after applying the method of the present invention. 1 is a diagram showing the relationship between the iron core and the magnetic tape of a magnetic head and a block diagram of a chime/playback circuit according to an embodiment, and this embodiment shows an example in which the frequency band end is divided into two.

In this embodiment, two independent iron cores of a magnetic head are disposed within one track width of the magnetic tape 1 in the width direction of the magnetic tape, facing the magnetic tape 1.

FIG. 2 shows an example of a 4-track 2-channel system, in which the first track 5 of the magnetic head is
The iron core 7 and the second iron core 8 of the magnetic head are opposed to each other, and the third iron core 9 and the fourth iron core 1 of the magnetic head are placed opposite to each other with respect to the second track 6.
0 and are placed facing each other.

Further, the first iron core 10 and the fourth iron core 10 are used for low frequencies, and the second iron core 8 and the third iron core 9 are used for high frequencies.

First, second, third and fourth cores 7.8.9517
, "8, heat 9 and ale, and the gap between the first iron core 7 and the second iron core 8 in the magnetic tape width direction and the gap between the third iron core 9 and the fourth iron core 10 in the magnetic tape width direction. If the gap between the second core 8 and the third core 9 in the width direction of the magnetic tape is C, then the width of the core 20 shown in FIG. Between C and l'==117+Jl-1-b='a@
-)11@-)bSC'=:C.
, third and fourth cores 7.8.9 and 100 width a? , Hatake S, a., Maro 1G and the gap bSc between them are set. Further, the gap is preferably b=c/2G-C1509 degrees.

Therefore, this embodiment is mechanically compatible with the conventional system.

Next, the gap lengths of the first to fourth cores 7 to 9 will be explained. Figure 3 (Maro) and -) Second and third iron cores 8.
9 and a plan view of a portion of the first and fourth iron cores 7.10. FIG. Gap length L of the first and fourth cores
t, LIO and the gap length L8 of the second and third iron cores,
Unlike L9, for example, Lt”Llo>Ls=L・
It is set to . Also, the air gap imposition of the first and fourth cores ``I, '10'' is different from the air gap imposition dll, 'll of the second and third iron cores, for example, dy = dto.
< da = ds K' Constantly, the core with shorter void length has a deeper void depth, and the core with longer void length has a shallower void depth.

Incidentally, one magnetic head may be constituted by the first to fourth iron cores 7-10, and each of the first to fourth iron cores 7-10 may constitute one magnetic head. . Iron core 1
0 may constitute another magnetic head.

Next, the bell sound and reproduction when the first to fourth iron cores 7 to 10 are not used will be explained.

Figure 4: Suzune in an example of applying the method of the present invention.
FIG. 3 is a psek diagram of a reproducing circuit.

11 - pre-amplifier, 12 - Suzune bias oscillator, 1
3a indicates a Suzune/No. 1 student selector switch, and 14 indicates a regenerative amplifier.

The recording amplifier 11 includes an input amplifier group 15 consisting of amplifiers 151 and 152 that amplify the signals of each channel input separately to the input terminals Tix and Ti2, and a four-pass filter 16 that divides the frequency band of the output signal of the amplifier 151. 'l and a low pass 7 that divides the frequency band of the output signal of the bypass filter 162 and the amplifier 152.
- frequency band division filter group 16 consisting of filter 163 and bypass filter 164;
Equalizers 171 and 172 for flattening the frequency characteristics during reproduction near the p-over frequency, and the bypass filter 162 and the low-pass filter 163 and bypass filter 164 flatten the frequency characteristics during reproduction near the p-over frequency. Evely f for
l? 3. Evelyz group 17 consisting of 174 and I′:1
It has a recording equalizer into which the output signals of the risers 1 to 174 are separately input, and inputs the output signals of the risers 1 to 174 separately through the bias traps to the respective recording equalizers 6 and 174 to input the output signals to the first to fourth iron cores 7 to 10. Switch 1 to change the coil of
3 and a drive circuit group 18 consisting of drive circuits 1'81 to 184, which are driven through the drive circuits 1'81 to 184.

On the other hand, the recording bias oscillator 12 branches its output signal and connects the capacitor 19 and resistor 23, the capacitor 20 and resistor 24, the capacitor 21 and resistor 25, and the capacitor 22.
and the resistor 26, and are superimposed on the output signals of the corresponding drive circuits 181 to 184 and sent to the first to fourth iron cores 7 via the changeover switch 13'.
~10 coils each separately. Note that each of the first to fourth iron cores 7 to 1 corresponding to each series circuit line consisting of capacitors 19 to 22 and resistors 23 to 26
The recording bias current value is set to be the optimum value for 0.

In the nine embodiments configured as described above, the input terminal Ti1
The audio signal of the first channel is applied to the input terminal T.
The audio signal of the '20th channel is applied to I2.

The first channel audio signal is amplified by amplifier 151 and applied to low pass filters 161 and 162.

'The amplitude characteristic lines of the filters 162 and 164 are set as shown by the solid lines in FIG. It was divided into two parts,
The low frequency side is output from the -p-pass filter 161, and the high frequency side is output from the 11-pass filter 162.

The output signal from the pass filter 161 and the output signal from the bypass filter 162 are inputted separately to 1.172, respectively, to flatten the frequency characteristics near the crossover frequency when the contents of the magnetic tape 10 are played back. 1811182, and are individually input to the drive circuit 1811182. The input signals of the drive circuits 181 and 1820 are level-adjusted in the drive circuits 181 and 182, respectively, and sent to the coil of the second iron core 7 and the second iron core via the recording/playback switch set to ``return''. 8
is applied to the coil. At the same time, a recording bias current set to an optimal value is passed through the fill of the first iron core 7 by a series circuit of a capacitor 19 and a resistor 23, and a recording bias current set to an optimum value is passed through the fill of the second iron core 8. A recording bias current set to an optimal value is passed through the series circuit.

Therefore, the frequency band of the audio signal of the first channel is divided and carried, and the high-frequency audio signal is transmitted to the second iron core 8, and the low-frequency audio signal is transmitted to the first iron core 7 of the magnetic tape 1. A low-frequency audio signal and a high-frequency audio signal are recorded in parallel on the track in the width direction of the magnetic tape 10. In this pigeon house, the frequency band of the audio signal of the first channel is divided into a low frequency side and a high frequency side, and a series circuit of a recording bias current line capacitor 19 and a resistor 23, and a series circuit of a condenser 20 and a resistor 24 are used. Because they can be set independently by the series circuit of A low-frequency audio signal and a high-frequency audio signal are respectively recorded on the first track 5 of the magnetic tape 1.

Similarly, the audio signal of the second channel applied to the input terminal Tit is divided into a low-frequency audio signal and a high-frequency sidetone signal on the second track 6 of the magnetic tape 1. Then, independent optimal recording bias currents are applied to each, and recording is performed in parallel.

Next, when reproducing the recorded content, switch the chime/reproduction selector switch 13 to the reproduction side, and select the first to fourth cores 7 to 1.
The voltage induced in the zero coil is input to the regenerative amplifier 14. In the regenerative amplifier 14, the voltages induced in the coils of the first and second iron cores 7 and 8 are mixed at a predetermined level, and then amplified to a predetermined level through a regenerative standard equalizer and output to the output terminal TOI. The audio signal of the first channel is obtained, and the third and fourth iron cores 9
The voltages induced in the coils 1 and 10 are similarly processed to obtain the second channel audio signal from the output terminal 'I'oz.

On the other hand, the gap length and gap depth in the iron core are generally related to strain, and the gap length is usually set to 172 or less of the recorded signal wavelength, taking into consideration the instantaneous electromotive force during reproduction. If the length is narrow, distortion increases during recording, and if the gap length is the same, the shallower the gap depth, the more distortion increases.

However, in this embodiment, as described above, the frequency band of the audio signal of each channel is divided by the first iron core 2, the second iron core 8, the third iron core 9, and the fourth iron core 10, and the magnetic tape 1- In addition to recording in parallel, the gap length L7, LIG of the eleventh and fourth cores 7.10 and the gap lengths 15Ls, Le of the second and third cores 8.9 are recorded in parallel.
In addition, the gap depths d7,dlo of the first and fourth cores 7.10 and the gap depths 'lI,' of the second and third cores 8.9 are made different. , this gap length L? (LIO) and Lm (Le) are set corresponding to the wavelength of each band-divided recording signal, and the optimum gap depth dt (dlo)・ds (
By setting ds), it is possible to improve the frequency characteristics of the scan more comprehensively than k.

Furthermore, the frequency characteristics and saturation characteristics are improved so that recording bias current values can be set at appropriate values for nine iron cores 7 (10) and 8 (9) K in response to each expanded band. Because of Kadeki.

Also, since there is an increase in the recording signal level based on the vowel bias current, the iron core □ #, L? 4,
. 46, 84, 7.1, the widths a8 and ms of cores 7 and 1b, which handle the low frequency side, are widened, and the widths a8 and ms of cores 8 and 9, which handle the high frequency side, can be made narrower. Possible, width at (ato) of iron core 7 (10)
>The width of the iron core 8 (9) ms (11G) can reduce the reduction in the reproduction level due to the division of the magnetic tape 10 in the width direction.

In addition, in a magnetic tape on which an audio signal is recorded by dividing the frequency by the first and second iron cores 7 and 8 and the third and fourth iron cores 9 and 1O, the information line on the track is As shown in FIG. Since the track is mechanically compatible with the magnetic head of the present invention, it is possible to normally obtain audio signal output even if the magnetic head that generates the sound of this embodiment is reproduced by a conventional magnetic head. It is compatible with traditional recording methods.

゛In addition, in the embodiment described above, the frequency 1 of the input audio signal is
This is an example of a case where the area is divided into two, and the gap length of the iron core is also set corresponding to the low-frequency side and the high-frequency side, respectively. Almost the same effect can be obtained by setting either one of them.

Furthermore, the embodiment described above can handle input audio signals.

Also, the magnetic head was explained as being used for both recording and playback purposes, but
The present invention can also be applied to a case where bell sounds and playback are respectively dedicated.

As explained above, according to the present invention, the frequency band of an input audio signal is divided, and one part of the magnetic tape is divided corresponding to the number of divisions.
This is achieved by arranging the iron cores of the magnetic heads to face each other within the track width and optimally setting the gap length and/or the gap depth of the iron cores in accordance with the wavelength of each band-divided recording signal. can improve distortion and frequency characteristics,
Furthermore, by optimally setting the recording bias current for each core, it is possible to improve the frequency characteristics and saturation characteristics.

(9) By selecting the width of the iron core, it is possible to reduce the decrease in the regeneration level.

It is also compatible with the conventional Suzune method.

[Brief explanation of drawings]

FIG. 1 is a relationship diagram showing the positional relationship between the core of the magnetic head and the magnetic tape when using a conventional recording method. FIG. 2 is a relationship diagram showing the positional relationship between the core of the magnetic head and the magnetic tape in an embodiment to which the method of the present invention is applied. FIGS. 3(1) and 3(b) are plan views of the iron core in FIG. 2. FIG. 14 is a block diagram of a bell sound reproduction circuit in one embodiment to which the method of the present invention is applied; FIG. 5 is an amplitude characteristic diagram of the p-pass filter and bypass filter in FIG. 4. l...magnetic tape, 5 and 6...track, 7.8.9 and 10...first, second, third and fourth iron cores of magnetic head , 11...
・Recording amplifier, 12...Suzune bias oscillator,
13...Bell tone/playback switch, 14...
...Regenerative amplifier, 161 and 163...
-One bus filter, 163! 164...Bypass filter, 171-174...Equalization, 181-184...Drive circuit. Patent applicant: Trio Co., Ltd.

Claims (3)

[Claims] (1) A magnetic head in which the frequency band of an input signal as a recorded signal is divided into a plurality of frequency bands, and at least one of the gap length and the gap depth is changed in accordance with each frequency band. An iron core is provided, and the iron core is arranged in the width direction of the magnetic tape so that it is located within one track width of the magnetic tape, and the band is divided into each of the coils wound around the iron core. 1. A method for producing bells on a magnetic tape, characterized in that each signal having a frequency band divided within the one track width is recorded in parallel by flowing an optimum bias current corresponding to the track width. (2) The method for producing bells on a magnetic tape according to claim 1, wherein the method differs depending on the width line frequency band of the iron core of the magnetic head. (3) The method for producing bells on a magnetic tape according to claim 1, wherein the widths of the cores of the magnetic heads are the same.