JPS587469Y2 - playback device - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a playback device that can adjust playback time without changing the pitch of an audio signal or the like.

When playing audio signals with a general audio playback device,
The playback is performed at the same time as when it was recorded.

However, with this playback device, when you want to listen to the content slowly, such as when shorthand while listening to the voice being played back, or conversely, when you want to listen to the voice spoken at a slow pace at high speed, the playback time can be changed. If the recording time is different, the pitch of the sound changes, resulting in a loss of intelligibility, and the above requirements cannot be met.

In order to solve this problem, a method can be considered in which only the playback time is expanded or compressed without changing the pitch of the sound during recording.

One is a method of sampling using a one-rotation head, and the other is a method of sampling a reproduced signal, as previously proposed by the applicant in Japanese Patent Application No. 451,285, titled "Pitch Conversion Device for Audio Signals." , it is further divided into smaller parts, written in a storage means, and read out using a different time relationship than when it was written.

The present invention aims to provide a playback device that belongs to the latter method.

That is, a playback device that keeps the sampling time constant and changes the time width of a signal that is finally expanded or compressed by a signal related to the playback speed, in particular, a playback means that can change the playback speed, and a signal related to the playback speed. sampling means for sampling the signal reproduced by the reproduction means; storage means for storing the signal sampled by the sampling means; and subdividing the signal sampled by the sampling means. It is an object of the present invention to provide a reproducing apparatus having a subdivision means and an output means for outputting a signal subdivided by the subdivision means in accordance with a signal generated by the signal generation means.

1. The principle of the playback device according to the method to which the present invention pertains is that the playback signal is sampled and it is further subdivided.
It will be explained that by writing this into the storage means and reading it out using a different time relationship from that at the time of writing, it is possible to expand or compress only the playback time without changing the pitch of the sound at the time of recording.

1. Consider the case where a signal with a constant frequency f is recorded and reproduced.

Replay the signal at the same speed as when it was recorded. In this case, a reproduced signal with a frequency f as shown in FIG. 1A is obtained.

In the sampling signal sampled from the reproduced signal at a fixed time T, a sine wave exists for Tf cycles during the fixed time T, as shown at the beginning of FIG.

Furthermore, if the reproduction time is made n times the recording time, the frequency during reproduction becomes f/n as shown in FIG.

1. As shown in FIG. 1 and 2, the time T is divided into m equal parts, and the signal level of the sampling signal is written into the storage means every T/m time.

That is, the reproduced signal existing at time T is subdivided into m pieces, and the subdivision signal levels are sequentially stored.

According to the sampling theorem, it is known that the original signal can be heard clearly enough if m/T≧2f in relation to the recording/reproducing frequency f.

Next, when the m subdivision signals written in the storage means as described above are read out every T/m·1/n time as shown in FIG. 1, m signals are read out in T/n time. can be read out.

In other words, the time interval T between the two failed signals is T/n
compressed into

For the time width T of the reproduced signal C, that is, for each sampling signal, the sine wave existed for T·f/n periods, so the T/n of the cuffed signal H read out from the storage means.
There is also a sine wave of Tf/n cycles between them.

Therefore, the frequency of this read signal E becomes f as shown in FIG.

In other words, when the playback time is n times the recording time, the time to read from the storage means is 1 times the time to write to the storage means.
/n, it is possible to expand or compress only the playback time without changing the pitch of the sound during recording.

The fundamental frequency of the human voice is approximately 100-1.70Hz for men.
(cycle about 6-10m5ec), about 250-500 for women
H2 (period: about 2-4 m5ec).

In addition, in order for the fundamental frequency to be heard as a pitch, waves of a certain period must be repeated an appropriate number of times, and this number of times is a frequency of 1-00 to 500 Hz.
It is about 3 times in the range of .

Therefore, the sampling time at the time of storing in the storage means is read out (converted to time T/n at .about.T/n).
= 30? ? By setting it to approximately Z see, it becomes possible to expand or compress the human voice.

Let us now consider the case of recording and reproducing audio in a band of 10 KHz 4.

When reproducing data in a time n times as long as recording time, the highest frequency f of the reproduced signal becomes 10×10 3 ·1/nHz.

Here, from the sampling theorem m/T≧2f, m/T
Considering the case of =2f, let f=10X103・1/n,
If T/n is set to T/n=30X10'sec, m=2X(l0XIO3Xi/n)XT2XIOX103Xi/nX30X10'-Xn00.

That is, when the latter method is implemented as a device, at least 600 memory elements are required as the memory means.

Conventionally, it has been almost impossible to incorporate such a large number of memory elements into a tape recorder or the like in a compact and inexpensive manner.

However, in recent years, with the development of IC technology, large-capacity analog memory devices have been developed, and a packet brigade device (hereinafter abbreviated as BBD), which is one of the charge transfer devices, has been developed.
Alternatively, a charge coupled device (CCD) or the like has been put into practical use.

In particular, BBD has several hundred samples and an S/N ratio of 60 dB. The harmonic distortion is 0.5% or less, the manufacturing cost is low, and it can be made extremely small.

Therefore, as will be described later, it is difficult to use the BBD as the storage means in the playback device of the present invention, and by doing so, the playback device can be fully incorporated into general audio equipment. be.

Next, when reproducing a recorded signal at a time different from the recording time in a reproducing apparatus belonging to the latter method, in order to make the pitch of the reproduced signal the same as the pitch of the recorded signal, it is necessary to write it into the storage means. The frequency f1 of the clock pulse of
and the frequency 12 of the clock pulse when reading from the storage means, the relationship f2n f1 needs to hold true.

Here, n indicates the time ratio between recording time and reproduction time.

Therefore, the reproducing device requires at least two oscillators to separately generate a clock pulse having an oscillation frequency f1 and a clock pulse having an oscillation frequency 12.

In order to keep the sampling time constant, if we keep the frequency 11 of the clock pulse constant when writing to the storage means and set the playback time ratio n to a desired value, then the clock pulse frequency f2 when reading is Inevitably, the f2=
It must be set to a value that satisfies the relationship of nf1.

However, in practice, the setting of the time ratio n and the setting of the frequency f2 are often performed using variable resistors, etc., and in that case, it is difficult to maintain the relationship f2nf1 by operating the two variable resistors. It is technically difficult to continuously change the set value with great difficulty.

Therefore, expansion and compression of playback time cannot be set continuously and arbitrarily.

The present invention has been made in view of the above points.

In other words, the playback device according to the present invention keeps the clock pulse frequency 11 constant during writing, and changes the clock pulse frequency f2 during readout in conjunction with the playback speed of the recording medium, thereby making the playback time continuous. This allows easy expansion and compression.

Hereinafter, one embodiment of the present invention will be described in detail according to the drawings.

FIG. 2 is a block diagram of an embodiment of a reproducing apparatus according to the present invention.

1 is a magnetic tape for recording and reproduction as a recording medium, 2 is a capstan, 3 is a pin roller, 4 is a tape supply reel, and 5 is a tape take-up reel. By doing so, the tape 10 is run.

A reproduction magnetic head 6 detects signals magnetically recorded on the tape 1 and converts them into electrical signals.

7 is a DC motor with an electronic governor, and the rotation speed is controlled by an electronic governor circuit 8.

As the driving means for the reproducing apparatus according to the present invention, it is quite possible to use another motor or the like in addition to the DC motor with an electronic governor.

9 is a variable resistor for varying the rotation speed of the motor 7.

The motor 7 includes a shaft 7a, pulleys 7b and 2e, and a belt 7d.
The capstan 2 is driven by.

10 is an opaque disk having slits at equal intervals on its circumference, and is set to rotate by increasing the rotational speed of the motor 7 via the shaft 7a of the motor 7, the pulley 7e, the belt 7f, and the pulley 10a. has been done.

11 is a lamp, and 12 is a light-receiving element such as a transistor. It performs photoelectric conversion and supplies the electrical output to the amplifier 130 input.

13 amplifies the output of the light receiving element 12 and generates a pulse signal 13a
It is an amplifier that creates

Reference numeral 14 denotes an audio preamplifier, which amplifies the reproduction signal from the reproduction head 6.

15 and 16 are the sampling of the playback signal and the memo described later! It is an electronic switch for circulating the contents of J 17 and 18, and has input terminals 15a and 15b and terminals 16a and 16b, respectively, and is switched by the output of a flip-flop 28, which will be described later.

Further, terminals 15a and 15a are connected to the output terminals of the preamplifier 14, and terminals 15b and 16b are connected to the output terminals of memories 17 and 18, respectively, which will be described later.

Memories 17 and 18 are used to store each level of the subdivided signals, and are constituted by charge transfer devices such as BBDs.

19 is an electronic switch for switching the output of Memo'J 17 and 18, and terminals 19a and 19a are connected to the input side.
19b, and is switched by the output of a flip-flop 28, which will be described later.

In the tape recorder, 20 is an audio amplifier having an equalization circuit for compensating the frequency characteristics required during playback, 21 is a variable resistor for volume adjustment, 22 is an audio main amplifier, and 23 is a loudspeaker. .

24 is a pulse oscillator that oscillates at a constant frequency.

Each step counter 2526 is reset by an electric circuit (not shown) when the tape 1 starts walking.

The counter 25 counts the output signal 34a of the oscillator 34, which will be described later, and the counter 26 counts the output signal 24a of the oscillator 24, and when the value reaches a certain value, the signal 25a is counted.
26a, and continues to hold the output signal until a counter reset signal, which will be described later, arrives.

27 is an AND circuit which outputs a signal 27a when both output signals of 25a and 26a are obtained.

The output signal 27a is applied to each of the counters 25 and 26 as a counter reset signal, and also serves as a trigger pulse for the flip-flop 28.

28 is a flip-flop, and when the tape 10 starts running, an electric circuit (not shown) outputs its output 28a.
becomes the L level, and the output signal 27a of the AND circuit 27
Therefore, the state level of the output is L-)H-+L→...
It changes sequentially as follows.

The output signal 28a of the flip-flop 28 is
5゜16.19 and electronic switch 29a, which will be described later.
and 30.

29 and 30 are clock pulse generation circuits 31 which will be described later.
．． 29a as an input terminal.

29b1, 30a and 30b, and is controlled by the output signal 28a of the flip-flop 28.

The terminals 29a and 30a are connected to the output of an oscillator 34, which will be described later, and the terminals 29b and 30b are connected to the output of the oscillator 24.

31 and 32 are clock pulse generation circuits that generate lock pulses necessary for transferring the contents of Memo 'J 17 and 18, respectively. In this embodiment, since a BBD is used as a charge transfer device, the charge transfer mode is A two-phase clock pulse train for controlling the mode is generated and supplied to the notes 'J 17 and 18, respectively.

As described later, the clock pulse generation circuits 31 and 32
The clock pulses generated by subdivide the sampled signal.

Regarding the relationship between the output 28a of the flip-flop 28 and the state of each switch, when the output 28a of the flip-flop 28 is at L level, the output of the switch 15 is sent to the input terminal 15a, the output of the switch 16 is sent to the input terminal 16b, and the output of the switch 16 is sent to the input terminal 16b. The output of switch 19 is connected to 19b, the output of switch 29 is connected to 29b, and the output of switch 30 is connected to 30a.
When 8a is at H level, the output of switch 15 is 15b,
The output of switch 16 is connected to 16a, the output of switch 19 is connected to 19a, the output of switch 29 is connected to 29a, and switch 3
The outputs of 0 are respectively connected to 30b.

33 is a signal generating means capable of controlling the voltage of an output signal by an input signal, such as a frequency-voltage converter, and the signal 13a from the amplifier 13 applied to its input terminal 33a.
A DC voltage 33b proportional to the frequency of is generated.

34 is an oscillator, and the frequency of the pulse signal 34a generated by the oscillation of the oscillator 34 is transmitted to its input terminal 34b.
is controlled by the DC voltage 33b applied to the signal 13
A pulse signal 34a having a frequency that is inversely proportional to the frequency of a is generated.

The disk 10, lamp 11, light receiving element 12, amplifier 13
, a frequency-voltage converter 33, and an oscillator 34 to obtain a pulse signal 34a with a frequency inversely proportional to the rotation speed of the motor 7.

That is, a pulse signal 34a having a frequency inversely proportional to the tape playback speed of the tape 1 is obtained.

In the above configuration, the tape speed when recording 1 tape 1 is v1, and the tape speed when playing back v1 is v/n, that is, the playback time is n times the recording time.

It is assumed that the speed of the tape during playback can be continuously varied around the speed (2) by adjusting the variable resistor 9.

In the following explanation, the alphabetical numbers attached to each terminal mentioned above also mean the signals that are input to or output from them, and conversely, the alphabetical numbers attached to each signal indicate the signals that are input to or output from them. shall also mean a terminal.

Further, it is assumed that the oscillation frequency 11 of the oscillator 24 is constant.

Since the oscillation frequency 12 of the oscillator 34 is inversely proportional to the tape playback speed, it is a value determined by the relational expression f2-α·n/v.

(α: constant) Therefore, by setting the oscillation frequency 12 of the oscillator 34 so that the constant α becomes α−f1v, the above-mentioned relational expression f2−n f 1 is satisfied.

Also, the counts of counters 25 and 26 are m, (
That is, the counters 25 and 26 start counting from the reset state and output signals 25a and 26a when m pulses have been applied to the human power.

), and the storage capacity (number of elements) of the memories 17 and 18 is similarly set to m.

When the tape 1 starts running, the counters 25 and 26 are reset by an electric circuit (not shown).
The output 28a of the flip-flop 28 becomes L level,
It is assumed that the contents of memories 17 and 18 are cleared.

Regardless of the running of the tape 10, the oscillator 24 generates a pulse signal 24a with a frequency of 11 as shown in FIG.
The input terminal 29b1 of switch 9 is supplied to the input terminal 30b of switch 30.

As shown in FIG.
The counter is reset from the point when f1 time has elapsed1
A signal 26a is output.

On the other hand, as the table 1 runs at a speed v/n, the oscillator 24 generates a pulse signal 34a with a frequency n f 1 as shown in the opening of FIG. power terminal 30a
is supplied to.

As shown in FIG. 32, the counter 25 starts counting when m input cavities are added, i.e., m·1−/
After the nf1 time elapses, the counter is reset to 1 and outputs a signal 25a as shown in FIG. 3-2.

Signal 25a. 26a are output, the AND circuit 27 outputs a signal 27a, the flip-flop 28 is inverted, and the level of its output 28a changes from L to H.

When n=1, output signals 25a and 26a are generated simultaneously.

n ) 1, signal 25a occurs first, signal 26
a occurs later.

n (if 1, signal 25a is generated later, signal 25a
occurs first.

First, the operation in the case of n) 1 will be explained.

FIG. 3 shows the operating waveforms of each part in FIG. 2 when n>1.

Since n>1, when the signal 26a is output, that is, after the counter 26 is reset, m/1. When the time elapses, an output signal 27a is generated in the AND circuit 27, and at the same time as the output signal 28a of the flip-flop 28 is inverted, the counters 25 and 26 are reset.

Here, it is assumed that the signal 28a becomes L level when inverted.

Assume that an audio signal whose fundamental frequency is f when reproduced from 1 to 1 at the same tape speed as the recording speed is recorded on tape 1-L.

The reproduction signal (its fundamental frequency f/n) detected by the reproduction head 6 is amplified by the preamplifier 14, and input to the input terminals 15a of the switches 15 and 16, respectively.

16a.

Since the signal 28a is at the L level, the input terminal of the memory 17 is supplied with the reproduction signal from the reproduction head 6, and the input terminal of the memory 18 is supplied with the output signal of the memory 18 in circulation.

During this period, the reproduced signal is sampled by the switch 15.

Furthermore, the memory 17 receives the clock pulse generation circuit 3 by the output signal 24a of the oscillator 24 via the switch 29.
A clock pulse (frequency 11) generated at 1 is supplied, and the reproduced signal level is stored every 1/f1 time and sequentially transferred in the memory 17.

That is, the reproduction signal (sampling signal) sampled by the switch 15 is subdivided by the clock pulses supplied from the clock pulse generation circuit 31 and stored in the memory 17.

On the other hand, the memory 18 is supplied with the clock pulse (frequency nf1) generated by the clock pulse generation circuit 32 by the output signal 34a of the oscillator 34 via the switch 30.
The contents of the memory 18 are transferred every /nf1.

The output signal from the memory 18 is input to the input terminal 1 of the switch 16.
6b, returns to the memory 18 and is sequentially transferred, and is then sent to the equalization amplifier 8S20 via the switch 19.
The signal is amplified by a variable resistor 21, its volume is adjusted by a variable resistor 21, further amplified by a main amplifier 22, and supplied to a loudspeaker 23, where it is converted into an audible signal.

Since the counter 26 generates an output signal 26a when m pulses arrive at its input terminal, the contents of the memory 17 are transferred m times.

Since the storage capacity of the memory 17 is m, when the contents of the memory 17 are all rewritten, the flip-flop 2
8 is inverted and becomes H level.

When the output signal 28a of the flip-flop becomes H level, the reproduction signal from the reproduction head 6 is supplied to the input terminal of the memory 18, and the reproduction signal from the reproduction head 6 is supplied to the input terminal of the memory 17.
7 output signals are supplied in cycles 1-.

During this period, the reproduced signal is sampled by the switch 16.

Furthermore, the clock pulse generation circuit 3 is stored in the memory 18 by the output signal 24a of the oscillator 24 through the input signal f30.
A clock pulse (frequency f1) generated at 2 and 7 is supplied, and the reproduced signal level is stored every 1/f1 time and sequentially transferred in the memory 18.

That is, the reproduced signal sampled by the switch 16 is subdivided by clock pulses supplied from the clock pulse generation circuit 32 and stored in the memory 18.

On the other hand, the clock pulse (frequency nf1) generated by the clock pulse generation circuit 31 is supplied to the memory 17 by the output signal 34a of the oscillator 34 via the switch 29.
/nf1 The contents of the memory 17 are sequentially transferred every time, and the contents are transferred to the equalizing amplifier 2 via the switch 19.
0, its volume is adjusted by a variable resistor 21, further amplified by a main amplifier 22, supplied to a loudspeaker 23, and converted into an audible signal.

That is, the reproduction signal from the preamplifier 14 (FIG. 3G) with the fundamental frequency f/n is alternately supplied to the memory 17.18 every m711 hours, and is further supplied with the clock generated by the clock pulse generation circuit 32.33. m by pulse
It is divided into equal parts and stored in the memories 17 and 18.

A reproduced signal with a fundamental frequency f/n has a fundamental number m
/f1 time, there are f/n-m/ft cycles.

When reading, 1/n f is stored in memory 1 every time.
Since the contents of 7.18 are transferred, it is possible to read out f-m/nf1 of the fundamental wave at time m/nf1, and the frequency of the fundamental wave of the read signal becomes f.

Here, since n) 1, m/f1>m/nf1,
The writing time to the memory 17, 18 is longer than the reading time.

Therefore, the read signal is converted into an audible signal and at the same time is supplied again to the input side of the memo IJ 17, 18, and the memo! It continues to circulate within J 17 and 18.

Therefore, at time m/f1 at 1 when the output signal 28a of the flip-flop 28 is inverted, the audio reproduction signal is repeatedly reproduced with its fundamental wave set to f.

As mentioned above, by alternately putting the memo IJ 17 and 18 into the writing/reading state in synchronization with the reversal of the flip-flop 28, only the time of the recorded signal is expanded without changing the recorded pitch, and the playback signal is sequentially expanded. It is being regenerated.

Next, the operation when n(1) will be explained.

In this case, even if counters 25 and 26 start counting at the same time, the output signal 26a of counter 26 is higher than that of counter 2.
It should occur earlier than the output signal 25a of No. 5.

At the time when the signal 25a is output, that is, when the counter 25.
26 starts counting and 1/nf1 time elapses, an output 27a is generated in the AND circuit 27, the counters 25 and 26 are reset, and the flip-flop 2
The output 28a of 8 is inverted from L level to H level (provided that the initial state is L level).

Here, since n (1), m/f 1<m/nf 1, and the writing time to the memory 17 and 18 is shorter than the reading time.

Therefore, for example, the signal stored in the memory 17 is
At the time when f·m/nf1 cycle of the fundamental wave of the signal is read out with /nf1, writing of f·m/nf1 cycle of the fundamental wave of the next reproduced signal has been completed in the other memory 18.

Therefore, by reversing the flip-flop 28, the write and read states of the memory 17 and 18 are also reversed.
The reproduced signal from tape 1 is compressed in time and sequentially reproduced without changing the recording power or pitch.

The operations of other parts are exactly the same as in case n)1.

As mentioned above, the frequency of the clock pulse required to read out the memory 17 and 18 is determined by detecting the rotational speed of the motor which is proportional to the tape speed, and by using a signal whose frequency is inversely proportional to the detected signal. .

Therefore, please note when changing the playback time continuously with the variable resistor 9! The frequency f2 of the clock pulse required when reading J 17 and 18 changes continuously.

Therefore, the playback time can be continuously expanded or compressed without changing the pitch during recording.

In the above embodiment, a disk 10 rotates in conjunction with the motor 7 and has slits at equal intervals on the circumference as a detection means for detecting the playback speed of a recording medium such as a tape.
When the disc 10 rotates in conjunction with the motor 7, that is, in conjunction with the running of the tape 10, a lamp 11 and a light-receiving element 12 are provided to sandwich the disc 10. The light from the lamp 11 that reaches the light receiving element 12 is photoelectrically converted by the light receiving element 12, and is used as a detection signal for the reproduction speed of the recording medium.

The detection means is not limited to the embodiments described above, and the purpose can be sufficiently achieved by recording a control signal together with an audio signal on a recording medium such as a tape, and using this as a detection signal. .

FIG. 4 is a diagram showing detection means for detecting the speed of the recording medium by this method.

In FIG. 4, the same parts as those shown in FIG. 2 are given the same reference numerals, and parts other than the detection means are omitted.

35 is a control signal playback head for detecting the control signal recorded on the tape 1 during recording; 36 is an amplifier for amplifying the control signal detected by the playback head 35; its output is based on the frequency - It is connected to the input terminal 33a of the voltage converter 33.

The tape 1 has tracks for recording and reproducing control signals in addition to tracks for recording and reproducing audio signals.

Instead of providing a special recording track for the control signal, a single track can be used for both purposes by setting the frequency fc of the control signal outside the audio signal band on the audio signal recording track.

The control signal is recorded in a sine wave waveform, a pulse waveform, or the like set so that the frequency fc becomes a certain constant value when the tape 1 is reproduced at the same speed as when it was recorded.

Note that the amplifier 36, frequency-voltage converter 33, and oscillator 34
Accordingly, the frequency 12 of the output signal 34a of the oscillator 34 is set to be inversely proportional to the frequency fc of the control signal detected by the control signal reproducing head.

Here, the ``certain constant value'' is assumed to be a value at which a relationship of 12-fl is established between the frequency 12 and the frequency f1 when the tape 1 is reproduced at the same speed as when it was recorded.

In the above configuration, since the frequency fc of the control signal on the tape 1 is constant, if the running speed of the tape 10 during playback is slower than the running speed during recording, that is, in the case of n) 1. The frequency fz (-=nft) of the output signal 34a of the oscillator 34 is equal to the output signal 24 of the oscillator 24.
When the running speed of the tape 1 during playback is higher than the running speed of the tape 1 during recording than the running speed during recording, that is, when n(1), the output signal 3 of the oscillator 34
The frequency 12 of 4a is lower than the frequency 11 of the output signal 24a of the oscillator 24.

The following operations are exactly the same as those in the previous embodiment.

In addition to the above-mentioned embodiments, as a means for detecting a signal proportional to the playback speed of a recording medium such as a tape, there is also a means for detecting an output proportional to the running speed of the recording medium, such as a combination of a magnet and a reed switch. If so, it can be fully used as a detection means for the reproducing apparatus of the present invention.

Furthermore, in the above embodiment, the tape speed during recording was considered to be only one speed, but in the case of a tape recorder that can change the speed to two speeds or two speeds, the oscillation frequency of the oscillator 24 and the counter may be adjusted accordingly. This can be achieved by changing the count numbers 25 and 26, or by changing the speed increasing ratio between the motor 7 and the disc 10 when increasing the rotational speed of the motor 7.

In the above two embodiments, in order to change the clock pulse frequency 12 at the time of reading and the reproduction speed of the recording medium in relation to each other, the reproduction speed of the recording medium is detected and the frequency 12 is controlled by the detected output. In Although,
Alternatively, for example, an oscillator whose frequency can be changed continuously may be provided, and the playback speed may be controlled by its output signal.

FIG. 5 is a diagram showing an example of the method.

The same parts as shown in Figure 2 are designated by the same reference numerals.
Components other than the playback speed control section are omitted.

37 is an oscillator which outputs a pulse signal 37a with a frequency of 12, and the oscillation frequency f2 is set to f by a variable resistor 38.
2-nfI, it can be varied continuously around frequency 11.

39 is a frequency-voltage converter, which converts a DC potential 39a that is inversely proportional to the frequency 12 of the output signal 37a of the oscillator 37.
is generated as an output signal.

The output signal 39a is supplied to the electronic cabana circuit 8.

The electronic governor circuit 8 controls the DC motor I to rotate at a rotation speed proportional to the voltage of the output signal 39a.

In the configuration of the capstan 2, bin roller 3, pulley 2c1 belt 7d1, pulley 7b, motor shaft 7a, motor 7, electronic governor circuit 8, and voltage-frequency converter 39, the tape 1 has a speed V that is inversely proportional to the oscillation frequency f2 of the oscillator 37. '-β/f2 (β: constant), tape 1
By setting the tape speed at the time of recording to be β""flv, V'-fl ・V/f2
-fl ・v/nf1v/n (however, f2-nfl)
becomes.

That is, the oscillation frequency 12 of the oscillator 37 is controlled by the variable resistor 38.
The oscillation frequency 12 changes the tape 1 by
Even if the playback speed is controlled, the same effects as in the two embodiments described above can be obtained.

In the three embodiments described above, the case where the playback device according to the present invention was incorporated into a tape recorder was explained.
It goes without saying that the present invention is not limited to this, and can be implemented with any recording/reproducing apparatus such as a record player.

As is clear from the above explanation, the present invention is a playback device that keeps the sampling time constant and changes the time width of the signal that is finally expanded or compressed depending on the signal related to the playback speed. It is possible to continuously expand or compress only the playback time without changing the pitch of the time.

Furthermore, if the above-mentioned BBD or the like is used as the memory, it can be sufficiently incorporated into general audio equipment.

In this embodiment, an equalization circuit for compensating the frequency characteristics necessary for audio reproduction is connected at the subsequent stage of the switch 19.

If this equalization circuit is installed before the reproduction signal frequency f/n is converted to the recording frequency f, for example after the preamplifier 14, the equalization characteristics must be changed in relation to the value of n. Therefore, it is difficult to obtain sufficient equalization characteristics for continuous values of n.

However, as in the above embodiment, the frequency f/
If the equalization characteristics are specified after n is converted to the recording frequency f, sufficient equalization characteristics can be easily obtained regardless of the value of n.

As mentioned above, the present invention has many advantages and advantages.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle of the present invention, Fig. 2 is a diagram showing an embodiment of the invention, Fig. 3 is a diagram showing waveforms of various parts when n) 1, and Fig. 4 is a diagram showing the detection means. A diagram showing another embodiment, FIG. 5 is a diagram showing an embodiment in which the reproduction speed is controlled by changing the oscillation frequency 12. 1...Magnetic tape for recording and reproduction, 6...
Reproducing magnetic head, 10...Disc with slit, 1
1... Lamp, 12... Light receiving element, 1
5.16,19,29゜30...Switch, 1
718... Memory, 3132... Clock pulse generation circuit, 24, 34° 37... Oscillator, 35... Control signal reproducing head, 33.3
9... Frequency-voltage converter.

Claims (1)

[Scope of utility model registration request] Reproducing means for reproducing a signal recorded on a recording medium, and capable of changing the reproduction speed with a speed corresponding to the speed at which the signal was recorded on the recording medium as the center, and a signal associated with the reproduction speed. a signal generating means for generating a signal, a sampling means for sampling the signal reproduced by the reproducing means, and a storage means for storing the signal sampled by the sampling means while segmenting the signal according to a reference signal having a predetermined constant frequency. and output means for outputting the reproduction signal stored in the storage means according to the signal generated by the signal generation means, thereby expanding or compressing only the reproduction time without changing the pitch of the sound at the time of recording. In the playback device, a speed switching means for switching the center speed to a playback speed corresponding to the two or more different speeds in order to play back a recording medium recorded at two or more different speeds; A reproducing device comprising: means for changing the frequency of the reference signal in accordance with switching of the switching means.