JPH0562345A - Audio magnetic recording/reproducing device - Google Patents

Abstract

(57) [Summary] [Purpose] The objective is to correct both the increase in volume of the playback sound of tape recorders and VTRs during high-speed running and the disruption of the sound quality balance to make the sound easier to hear. [Structure] A high-frequency attenuation circuit is provided in the latter stage of the reproduction equalizer circuit, which is controlled so that the high frequency is attenuated as the traveling speed of the magnetic tape increases. At the time of n times speed, the high-frequency side bend of the reproduction equalizer frequency characteristic is provided. By controlling the frequency equivalently to n times the steady speed, the average sound volume and the sound quality balance during high-speed running are not changed, and the sound is easy to hear.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an audio magnetic recording / reproducing apparatus for an audio tape recorder or a video tape recorder (hereinafter abbreviated as VTR) having audio recording tracks for recording in the longitudinal direction of a magnetic tape.

[0002]

2. Description of the Related Art In recent years, audio tape recorders have been remarkably popularized and various proposals have been made for their uses. In particular, when searching where on the tape surface the recording is performed, it is often requested that the tape be run at a high speed and that a reproduced sound is generated with an appropriate volume and sound quality.

A conventional audio magnetic recording / reproducing apparatus will be described below with reference to the drawings.

As shown in FIG. 4, in the reproducing equalizer circuit used in the conventional audio magnetic recording / reproducing apparatus, the output signal from the magnetic head 1 is amplified by the amplifier 2 and output from the output terminal 7. A feedback circuit composed of the capacitor 3, the resistor 4, the first resistor 5 and the second resistor 6 is provided between the output side of the amplifier 2 and the negative phase input side.

The operation of the reproducing equalizer circuit of the audio magnetic recording / reproducing apparatus configured as described above will be described below.

First, an audio tape recorder and a VT
The reproducing circuit of the R audio track in the longitudinal direction of the tape is basically an integrating circuit. This is because the reproduction output characteristic of the magnetic head has a differential characteristic proportional to the frequency. However, high frequency loss factors such as gap loss and spacing loss exist between the magnetic tape and the magnetic head. In order to correct this, in the reproduction equalizer circuit, as shown by the solid line in FIG. 2, the part above a certain bending frequency f ₂ has a flat characteristic instead of an integral characteristic.

Next, in FIG. 4, the value of the first capacitor 3 is C ₃ , and the values of the resistors 4, 5, 6 are R ₄ , respectively.
When R _5, R _6, the frequency f ₁ in FIG. 2 is a (number 1), f ₂
Can be expressed by (Equation 2).

[0008]

[Equation 1]

[0009]

[Equation 2]

Since R ₄ is usually sufficiently larger than R ₅ and R ₆ , f ₂ can be approximated by (Equation 3).

[0011]

[Equation 3]

Here, when a tape recorder or VTR is used for a search operation, the magnetic tape is run at high speed while listening to the reproduced sound. At this time, when traveling at a speed n times the steady speed, the frequency of the signal reproduced by the magnetic head becomes n times, and since the magnetic head has differential characteristics, the magnetic head reproduction output level of each frequency component is increased. Becomes n times (especially because the gap loss and pacing loss do not change). Therefore, if the reproduction equalizer characteristic is the integral characteristic, the level of each frequency component of the reproduction equalizer output does not change, that is, the balance of the sound quality does not change, and the frequency simply becomes n times. In the reproduction equalizer circuit with such characteristics,
Since f _{2 and} above are not integral characteristics but are flat, frequency components above f ₂ are increased n times to enhance the high frequency range, that is, the sound quality is out of balance, and the average volume is also increased. It becomes a sound. This state is shown in FIG.
Shown in. FIG. 5A shows the frequency characteristic of the reproduced sound when reproduced at a constant speed, and the shaded area shows the energy distribution of the reproduced sound. FIG. 5B shows the frequency characteristics and the energy distribution of the reproduced sound when reproduced at n times speed, and the energy distribution is biased toward the higher frequency as the speed is increased by n times.

In order to eliminate such annoying sound when running at high speed, a method of inserting an attenuator as shown in FIG. 6 on the output side of the reproduction equalizer has been conventionally used. 6, the same components as those in FIG. 4 are designated by the same reference numerals and correspond to each other. The resistors 8 and 9 constitute an attenuator, and a switch 10 is provided, and the switch 10 is closed during high-speed traveling so that the reproduction equalizer output is attenuated. However, although such a method has an effect of suppressing an increase in volume during high-speed traveling reproduction, it has no effect of correcting the balance of sound quality.

[0014]

However, in the above conventional configuration, when performing a search operation with a tape recorder or a VTR, when the magnetic tape is run at a high speed while reproducing a sound, the constant speed is N
When the vehicle is run at double speed, the frequency of the signal reproduced by the magnetic head becomes n times, and the magnetic head reproduction output level of each frequency component becomes n times, so that the sound is remarkably offensive when traveling at high speed. Had a problem.

The present invention solves the above-mentioned problems of the prior art. Audio magnetic recording for reproducing a sound that is easy to listen to by correcting both the increase in the volume of the sound reproduced by the tape recorder and the VTR at high speed and the loss of the sound quality balance. An object is to provide a reproducing device.

[0016]

In order to achieve the above object, in the audio magnetic recording / reproducing apparatus of the present invention, the high frequency band is attenuated as the running speed of the magnetic tape increases in the subsequent stage of the reproducing equalizer circuit. It has a structure for providing a controlled high frequency attenuation circuit.

[0017]

The present invention has the above-described structure,
It is possible to prevent the level of the frequency of f ₂ or higher from increasing n times, and to make the sound easy to hear without changing the average volume and the sound quality balance.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, the same components as those shown in FIG. 4 of the above-mentioned conventional example are designated by the same reference numerals, and the description thereof will be omitted. The characteristic configuration of the present embodiment is that a high-frequency attenuation circuit in which a third resistor 11, a fourth resistor 13, a second capacitor 12 and a switch 14 are newly connected in series is provided.

The operation of the main circuit of the audio magnetic recording / reproducing apparatus having the above structure will be described with reference to FIG.

When the magnetic tape is running at a constant speed, the switch 14 is open, and the frequency characteristic of the reproduction equalizer circuit forming the main circuit of this embodiment is f as shown by the solid line in FIG. _A characteristic of bending at ₂ .

Next, the magnetic tape running speed is increased by n times.
Then, the switch 14 is closed. When switch 14 is closed
The frequency characteristics of the high frequency attenuation circuit of
6 dB above the first bending point frequency, which is the starting point of the decay
/ Oct and descends above the second bending point frequency.
It becomes a rat, but the first bending point frequency is f ₂
And the frequency at the second bending point is nf₂That is, f₃
High-frequency attenuation circuit resistance and capacitor values to
When set to, the playback equalizer times including the high frequency attenuation circuit
The frequency characteristics of the entire road are high frequency side as shown by the broken line in FIG.
Bending frequency is f₂To f₃Is equivalent to rising to
It Here, the value of the third resistor 11 is set to R₁₁, The second conde
The value of sensor 12 to C₁₂, The value of the fourth resistor 13 is R₁₃age,
If you set them to satisfy the above conditions,
f₂, F₃Can be expressed by (Equation 4) and (Equation 5).

[0023]

[Equation 4]

[0024]

[Equation 5]

Substituting the relationship of f ₃ = nf ₂ into (Equation 4) and (Equation 5) gives (Equation 6).

[0026]

[Equation 6]

In order to satisfy these equations, R ₁₁ , C ₁₂ ,
The value of R ₁₃ should be set. In this way, when the magnetic tape running speed is increased n times, the high-frequency bending point frequency is equivalently set to nf ₂ or f ₃ ,
Even if the magnetic tape running speed increases by n times, neither the average volume of the reproduced sound nor the sound quality balance changes. The reason will be described below.

First, when the magnetic tape is running at a constant speed, the reproduction level of the magnetic head becomes n times as high as the n times speed of the components of f ₂ or less, but the characteristics of the reproduction equalizer circuit are f ₃ or nf. _{Since the} integral characteristic extends to 2,
The output of the reproduction equalizer circuit does not change. In addition, the component of f ₂ or more at the steady speed was originally equalized in the flat portion, but at the n-fold speed, the reproduction level of the magnetic head becomes n times, but the portion of the reproduction equalizer circuit at f ₃ or more is equal to or greater than n. That is, since the response is equalized at a flat portion of 1 / n with respect to the steady speed, the output of the reproduction equalizer does not change.

In the present embodiment, the second capacitor 1
Although only one set of the circuit in which the second and fourth resistors 13 and the switch 14 are connected in series is provided, in the case where the speed during high-speed running changes in multiple stages, a plurality of sets of capacitors, resistors and switches may be provided. It may be provided and the switch may be switched depending on the speed.

[0030]

As described above, according to the present invention, a high-frequency attenuation circuit that is controlled so as to attenuate the high frequency as the traveling speed of the magnetic tape increases is provided in the subsequent stage of the reproduction equalizer circuit, and the n-fold speed is provided. At times, the bending point frequency on the high frequency side of the reproduction equalizer frequency characteristic is equivalently controlled to be n times that at steady speed, so that the average volume and sound quality balance during high-speed running do not change and it is easy to listen to. It is possible to realize an excellent audio magnetic recording / reproducing apparatus capable of producing sound.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a main part of an audio magnetic recording / reproducing apparatus according to an embodiment of the present invention.

FIG. 2 Frequency characteristic diagram of the same circuit

FIG. 3 is a frequency characteristic diagram of a high frequency attenuation circuit section of the same embodiment.

FIG. 4 is a circuit diagram of a main part of a conventional audio magnetic recording / reproducing apparatus.

FIG. 5 (a) is a frequency characteristic diagram of a tape in the same circuit at a constant speed, and (b) is a frequency characteristic diagram of a tape in the same circuit at an n-fold speed.

FIG. 6 is another circuit diagram of a main part of a conventional audio magnetic recording / reproducing apparatus.

[Explanation of symbols]

 1 Magnetic Head 2 Amplifier 3 First Capacitor 5 First Resistor 6 Second Resistor 11 Third Resistor 12 Second Capacitor 13 Fourth Resistor 14 Switch

Claims (3)

[Claims] 1. A magnetic head for reproducing an audio signal recorded in a longitudinal direction of a magnetic tape, an amplifier whose output from the magnetic head is input to a positive-phase input terminal, and a negative phase of the output of the amplifier. Regeneration composed of a circuit including a series connection circuit of a first capacitor and a first resistor connected between input terminals, and a second resistor connected between the negative-phase input terminal of the amplifier and the ground After the front part of the equalizer circuit, a high-frequency attenuation circuit that controls the high-frequency attenuation as the traveling speed of the magnetic tape increases is provided. An audio magnetic recording / reproducing apparatus in which the frequency characteristic of the front stage of the equalizer circuit is set near the bending point frequency on the high frequency side. 2. A third resistor connected in series to a signal path, and a second capacitor, a fourth resistor, and a switch connected in series between the output side of the third resistor and the ground. The audio magnetic recording / reproducing apparatus according to claim 1, wherein a high-frequency attenuation circuit is configured with the circuit. 3. A circuit comprising a plurality of series-connected circuits of a second capacitor, a fourth resistor and a switch, wherein predetermined ones of the switches are sequentially switched according to the magnetic tape speed. Item 1. The audio magnetic recording / reproducing apparatus according to Item 1.