JPS61175930A - Tape recorder - Google Patents

Abstract

PURPOSE:To make a sound recording equalizer element of a sound recording amplifier unnecessary at the time of a high speed by setting a low band turnover frequency of the time of a high speed so as to become the same quantity as a reproducing frequency compensating quantity of the time of a constant speed, at a frequency point of an integer multiple against a low band turnover frequency of the time of a constant speed, when a tape speed is high. CONSTITUTION:A signal magnetic flux which is picked up by a reproducing head 12 is voltage- amplified by an amplifier and appears in an output terminal 14, after a reproducing frequency compensation determined by the first reproducing equalizer element 6 is executed. Also, the reproducing signal which is voltage-amplified by the amplifier 13 is applied to an input side of a sound recording amplifier 11, too, and after a sound recording compensation determined by a sound recording equalizer element 12 is executed, said signal is superposed onto a bias current from a bias oscillator 20 and applied to a sound recording head 4, and recorded in a tape. Also, when a tape speed is set to 28.8cm/s of a high speed by a tape speed switching means 5, a reproducing equalizer element changeover switch 9 which is switched in accordance with said setting is switched to a side (b), and the signal is recorded in a tape in the same way as the time of 4.8cm/s of a constant speed, therefore, a signal which is reproduced by the first mechanism part can be sound-recorded by the second mechanism part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention has a plurality of mechanism parts, and is used for so-called dubbing, in which a signal reproduced by a playback head of a first mechanism part is recorded by a recording head of a second mechanism part. The present invention relates to a tape recorder having such functions.

2. Description of the Related Art In recent years, in order to shorten the dubbing time, tape recorders capable of dubbing have increasingly adopted a high-speed dubbing method in which the tape speed is made faster than the normal speed (constant speed) only during dubbing.

An example of the conventional tape recorder capable of high-speed dubbing will be described below with reference to the drawings.

FIG. 4 shows a block diagram of a conventional tape recorder capable of high-speed dubbing, in which 1 is the mechanism of the playback tape recorder including the playback head 2, and 3 is the mechanism of the recording tape recorder including the recording head 4. 5 is a tape speed switching means, 6 is a reproducing amplifier that amplifies the signal from the reproducing head 2, and 7 and 8 are a negative feedback circuit system of the reproducing amplifier 6, which controls the reproduction frequency equalization characteristic (reproduction equalizer characteristic). The first and second reproduction equalizer elements to determine, 9 is a reproduction equalizer characteristic changeover switch that is switched in accordance with the set speed of the tape speed changeover means 6;
The second regenerative equalizer element 7 is connected to the terminal 9a, the second regenerative equalizer element 8 is connected to the terminal 9b, and the common terminal 9C is connected to the output end of the regenerative amplifier 6.

One end of 1o and 11 is grounded, and the other end is connected to the regenerative amplifier 6.
Terminals 12a and 12b of a level changeover switch 12 whose movable end is a semi-fixed volume connected to the output end of the level changeover switch 12 and whose movable end is changed over in accordance with the set speed of the tape speed changeover means 5.
is connected to the input end of the amplifier 13 via the common terminal 12c.

14 is an output terminal to which the output terminal of the amplifier 13 is connected; 15
is a recording amplifier whose input terminal is connected to the output terminal of the amplifier 13; 16 and 17 are in the negative feedback circuit system of the recording amplifier 15; 1 and a second recording equalizer element; 18 is a recording equalizer characteristic changeover switch that is switched in accordance with the set speed of the tape speed switching means 5; the first recording equalizer element 16 is connected to the terminal 18a; 17 is connected to the terminal 18b, and the common terminal 18c is connected to the output end of the recording amplifier 16.

19 is a bias trap, 20 is a bias oscillator, the output of the recording amplifier 15 is connected to the recording head 4 via the bias trap 19, and the recording signal passing through the bias trap 19 is superimposed on the bias current from the bias oscillator 2o. It is connected to be added to the recording head 4.

The operation of the conventional tape recorder configured as described above will be described below.

Now, suppose that the tape speed is conditioned to be a constant speed of 4.8 crn/' r high speed of 28.8 α/8, and when this is changed by the tape speed switching means 6, the reproduction equalizer characteristic changeover switch 9 and the level changeover will be changed accordingly. The switch 12 and the recording equalizer characteristic changeover switch 18 each have a constant speed of 4.8 cm/8 on the a side.
Assume that the b side has a high speed of 28.8 cm/II.

First, the tape speed is set to 4. When set to BCWl/B, the signal magnetic velocity picked up by the reproducing head 2 is converted into a voltage and applied to the regenerative amplifier 6, which is determined by the first reproducing equalizer element 7 selected by the reproducing equalizer characteristic changeover switch 9. After reproduction frequency compensation is performed, the signal passes through a semi-fixed volume 11, is amplified in voltage by an amplifier 13, and appears at an output terminal 14.

Note that the semi-fixed volume 11 is adjusted so that the level at the output terminal 14 becomes a predetermined value.

Furthermore, the playback signal voltage amplified by the amplifier 13 is also applied to the input terminal of the recording amplifier 16, and after being subjected to recording compensation determined by the first recording equalizer element 16 selected by the recording equalizer characteristic changeover switch 18,
It passes through the bias trap 19, is superimposed with the bias current from the bias oscillator 20, and is applied to the recording head 4,
The sound is converted electromagnetically and recorded on tape.

Further, when the tape speed is set to a high speed of 28.8 cm/II by the tape speed switching means 5, the three switches corresponding to this are switched to the b side, and the above-mentioned constant speed of 4.8 cm/II is set. Since it is recorded on tape in the same way as in the case of cm/8, the signal reproduced by the first mechanism section can be recorded by the second mechanism section. In other words, even at a constant speed of 4.8 cm/s, a high speed of 28.8 cm
A dubbing operation will also be performed at /B.

Furthermore, the reproduction equalizer characteristics and recording equalizer characteristics of a conventional tape recorder will be explained using FIGS. 5 and 6.

FIG. 6 is a reproduction equalizer characteristic curve diagram showing the relationship between frequency and gain of the reproduction amplifier 6 in FIG.
．． The characteristics of the conventional example are shown at 8 Cnl/H and at a high speed of 28.8 cm/s, which is an integral multiple of that speed.

In FIG. 5, curve A is the characteristic when the constant speed is 4.8 trn/s, and curve B is the characteristic when the high speed is 28.8 cm/s.

The characteristics of curve A are a straight line with a middle range of 6dB10at and a low range of 5
It is bent at two places: 0Hz and high M, 1326Hz.

Furthermore, the characteristic of curve B is that the mid-range is e, similar to the characteristic to the curve.
dBloat straight line, low range 300 yen and high range 7951 yen
It is bent at two places.

In other words, when switching the tape speed from a constant tape speed to a high speed that is an integral multiple of that speed, the turnover frequencies of the low and high frequencies are each shifted to an integral multiple of the high frequency range, and the tape is recorded with the same recording magnetic flux density. For the frequency of the reproduction band, the reproduction amplifier 6
The output level is always kept constant.

Figure 6 is a recording equalizer characteristic curve diagram showing the relationship between the recording current flowing to the recording head 4 in Figure 4 versus frequency, when the tape speed is 4.8 m/8 and at an integral multiple of that speed. This shows the use of low-frequency recording equalizer characteristics at a high speed of 28.8 cm/s.

Note that for convenience of explanation, only the middle and low range portions are shown.

In Fig. 6, when the curve A is at a constant speed of 4.8 cm/'',
Curve B is the low frequency recording equalizer characteristic when the high speed is 28.8 cm/+i.

The characteristic of curve A is that the frequency increases by 3 dB at 50 yen, and the characteristic of curve B is such that the frequency increases by 3 dB at 300 Hz.

The concept of the playback equalizer characteristics and recording equalizer characteristics explained above is based on considering a recording amplifier with recording characteristics such that flat characteristics can be obtained through the reproduction amplifier 6 having the frequency characteristics as explained in Fig. 6. be.

That is, the sdB decrease in gain at the low-pass turnover frequency points of curves A and B shown in FIG. 6 is compensated for during recording as shown in FIG.

Problems to be Solved by the Invention However, in the conventional configuration described above, by providing a plurality of tape speeds such as constant speed and high speed, the reproduction equalizer element of the reproduction amplifier and the recording equalizer element of the recording amplifier (especially low frequency It is also necessary to provide one for constant speed and one for high speed, respectively, which increases the number of parts and complicates the switching circuit, resulting in higher costs. was.

In view of the above-mentioned problems, the present invention compensates for the playback frequency at a frequency point that is an integral multiple of the low turnover frequency at constant speed when the tape speed is high. By setting the same wave number for low-frequency turnover at high speeds, a recording equalizer element of the recording amplifier is not required at high speeds, and the table recorder that can be dubbed at high speed solves the above drawbacks.In order to solve the above problems, the tape of the present invention The recorder includes a playback head and a playback amplifier placed on a first mechanism section, a recording head and a recording amplifier placed on a second mechanism section, and the first mechanism section and the second mechanism section. tape speed switching means for switching the tape speed between a constant speed and a high speed that is an integer multiple of the tape speed; Dubbing recording is enabled by the recording head of the second mechanism unit via an amplifier, and equalization is performed by the reproduction frequency compensation means of the reproduction amplifier in accordance with the set speed of the tape speed switching means. The turnover frequency of the characteristic is configured to be switched between a low range and a high range, and when the set speed is the high speed, the turn over frequency of the characteristic is set at a frequency point that is an integral multiple of the low range turnover frequency at the constant speed. The low turn over frequency at high speed is set to be the same amount as the reproduction frequency compensation amount at constant speed. It is possible to implement a design that omits the "purpose of operation", and it is possible to add a high-speed dubbing function with a simple configuration.

Embodiment Hereinafter, a tape recorder according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 shows a block diagram of a tape recorder in one embodiment of the present invention.

In FIG. 1, the same components as those in FIG. Mechanism section, 5 is tape speed switching means, 9 is a playback equalizer characteristic changeover switch, 13 is an amplifier, 14 is an output terminal, 19 is a bias trap, 2o
is a bias oscillator, which has the same configuration and connection relationship as the conventional example shown in FIG.

8 is a reproducing amplifier that amplifies the signal from the reproducing head 2;
and 7 are in the negative feedback circuit system of the regenerative amplifier 8, and are the first
and a second reproduction equalizer element, the first reproduction equalizer element 6 is connected to the terminal 9a of the reproduction equalizer changeover switch 9, and the second reproduction equalizer element 7 is connected to the first child 9b.
are connected to each other, and the common terminal 9c is connected to the output terminal of the regenerative amplifier 8.

11 is a recording amplifier whose input terminal is connected to the output terminal of the amplifier 13; 12 is a negative feedback circuit system of the recording amplifier 11;
Recording frequency equalization characteristics (especially low frequency recording equalizer characteristics)
It consists of a recording equalizer element, which determines the

The operation of the tape recorder of the embodiment configured as described above will be explained below.

Now, let's assume that the tape speed is set to constant speed 4.
8Lyn/s, melting speed 28.8 cm/B, and when these are switched by the tape speed switching means 5, the playback equalizer characteristic switch 9, which is correspondingly switched, sets the a side to a constant speed of 4.8 on/II.
Assume that the b side has a high speed of 28.8 rm/B.

First, the tape speed is set to 4 by the tape speed switching means 5.
．． 8 cm/', playhead 2
The signal magnetic flux picked up at and appears at the output terminal 14.

Furthermore, the playback signal voltage amplified by the amplifier 13 is also applied to the input side of the recording amplifier 11, and is applied to the recording equalizer element 1.
After the recording compensation determined by 2 is performed, the signal passes through the bias trap 19, is superimposed with the bias current from the bias oscillator 20, is applied to the recording head 4, is electromagnetically converted, and is recorded on the tape.

Further, when the tape speed is set to a high speed of 28.8 cm/s by the tape speed switching means 5, the reproduction equalizer element selection switch corresponding to this is switched to the b side, and the above-mentioned constant speed 4 is set. .8 cm
/ Since it is recorded on tape in the same way as in 8,
The signal reproduced by the first mechanism part can be recorded by the second mechanism part. That is, constant speed 4.8om/B
However, the dubbing operation will be performed even at a high speed of 28.8 cm/8.

In the example, the recording amplifier was operated at a constant speed of 4.8 crn/
s and a high speed of 28.8 cm/', and its operation is also explained.
ffi / 8 times the speed of 11 o'clock (3s, 4cm/s
) etc., it may be more convenient in terms of design to provide separate recording amplifiers for constant-speed and high-speed use, but it goes without saying that such a configuration may be used.

Furthermore, the playback equalizer characteristics and recording equalizer characteristics of the tape recorder of one embodiment will be explained using FIGS. 2 and 3.

FIG. 2 is a reproduction equalizer characteristic curve diagram showing the relationship between frequency and gain of the reproduction amplifier 8 in FIG. This is shown as an example characteristic at 28.8 cm/s.

In Fig. 2, when the curve A is at a constant speed of 4.86n/B,
Curve B is the characteristic at 28.8 cm/s.

The characteristic of curve A is a straight line with a middle range of 6 ciB/oCt, which is bent at two points: low M, 60-, and high range 1326 Hz.

Furthermore, the characteristic of curve B is similar to the characteristic of curve A, with a midrange of 6.
The low frequency turn-over frequency on the straight line of dB10C1 is a frequency point (300 Hz) that is an integral multiple (6 times) of the turnover frequency 508 at constant speed, and is the same as the reproduction frequency compensation amount at constant speed. The high frequency turn over frequency is a frequency point (79618E) that is an integral multiple (six times) of the constant speed turnover frequency &1326Hz.

In other words, when switching the tape speed between a constant speed and a high speed that is an integer multiple of that speed, the turnover frequency in the high range is shifted by an integer multiple, and the turnover frequency in the low range is the same as the low one at constant speed. At a frequency point that is an integer multiple of the area turnover frequency,
Turnover frequency &4 where the amount of playback frequency compensation is the same
By lowering the frequency in the reproduction band recorded with the same recording magnetic flux density, the output level of the reproduction amplifier 8 is always kept constant in the high range, and in the low frequency range, the output level of the reproduction amplifier 8 is kept constant at constant speed. It is designed to become 3 dB higher at frequency points that are integral multiples.

Fig. 3 is a recording equalizer characteristic curve diagram showing the relationship between the recording current flowing to the recording head 4 in Fig. 1 and the frequency when the tape speed is 4.8 crn/8 and at an integer multiple of that speed. Even at high speed of 28.8 crn/s, there is no change in the mid-low range.

Note that for convenience of explanation, only the middle and low range portions are shown.

In FIG. 3, the characteristic of curve A is such that the output increases by 3 dB at 50 outputs.

In other words, the gain decreases by 3 dB at the low turnover frequency point of curve A (at constant speed) shown in Figure 2, which requires compensation during recording as shown in Figure 3. By setting the turn over frequency as shown in B (at high speed), it is now possible to perform the low frequency compensation that was conventionally compensated during recording without increasing the number of parts during playback, making it possible to compensate for low frequency recording at high speed. It is possible to implement a circuit design that omits the .

Effects of the Invention In the present invention, when the tape speed is an integer multiple of the constant speed, at a frequency point that is an integer multiple of the low turnover frequency at the constant speed, the amount of compensation for the playback frequency at the constant speed is the same as that at the constant speed. By setting the low frequency turnover frequency at high speeds so that the
Furthermore, it is possible to realize a tape recorder that can obtain a number of excellent effects such as being able to add a high-speed dubbing function at low cost with a simpler circuit configuration.

[Brief explanation of the drawing]

A block diagram of a conventional tape recorder, FIG. 5 shows a conventional reproduction equalizer characteristic curve, and FIG. 6 shows a conventional recording equalizer characteristic curve. 2... Playback head, 4... Recording head, 5... Tape speed switching means, 6, 7...
...Reproduction equalizer element, 8...Reproduction amplifier, 9...Reproduction equalizer characteristic selection switch, 1
1... Recording amplifier. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure 2 Figure yfI Jiyu Iyu (I (ln Figure 3) 14 Figure 5 Figure M Shiojo tH'zNo. 6 Figure TrI Calculation CH71]

Claims (1)

[Claims] A playback head and a playback amplifier placed on a first mechanism section, a recording head and a recording amplifier placed on a second mechanism section, and tape speeds of the first mechanism section and the second mechanism section. tape speed switching means for switching between a constant speed and a high speed that is an integer multiple of the tape speed, and a reproduction signal reproduced by the reproduction head of the first mechanism section, amplified by the reproduction amplifier, and transmitted through the recording amplifier. The recording head of the second mechanism section enables dubbing recording, and the equalization characteristic is turned over by the reproduction frequency compensation means of the reproduction amplifier in accordance with the set speed of the tape speed switching means. The frequency is switched between a low range and a high range, and when the set speed is the high speed, the reproduction at the constant speed is performed at a frequency point that is an integral multiple of the low range turnover frequency at the constant speed. A tape recorder in which the low frequency turnover frequency at the high speed is set to be the same amount as the frequency compensation amount.