JPS63131375A - Rotary head type recording and reproducing device - Google Patents

Abstract

PURPOSE:To realize a reproducing signal equivalent to an original audio signal by providing a data rate converter and a data rate inverse converter and converting a data being digitized audio signal into a data synchronously with a field period of a video signal. CONSTITUTION:The data rate converter 11 and the data rate inverse converter 12 are provided to convert an audio data not synchronously with the field period of the video signal into the data synchronously with the field period of the video signal. Then data number information in a data frame formed with section at conversion is recorded and reproduced altogether. Thus, even if the field period of the video signal is fluctuated and a processing speed deviation is caused between the processing speed of the video signal and the digitized processing speed of the audio signal, the audio signal is digitally processed in following to the deviation and recorded to reproduce a signal equivalent to the original audio signal.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a rotary head type recording/reproducing device.

BACKGROUND ART Conventionally, a rotary head type recording/reproducing means has at least two heads, one for video and one for audio, and the video head performs analog modulation (such as frequency modulation and two-phase modulation) of the video signal. In a rotary head type recording and reproducing device that records and reproduces the audio signal by digitally modulating the audio signal using the audio head, the audio head is installed on a rotating cylinder that rotates in synchronization with the field period of the video signal. When recording and playing back audio signals with the head, at least 2
In order to avoid missing playback signals due to head switching between two audio heads, it is necessary to compress and record the digitized audio data in integer units during the head switching period, and the sampling period of the audio signal is changed depending on the head switching period. It was necessary to set it to an integer fraction of the period.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A two-head rotary head type recording and reproducing apparatus will be described below as an example of the above-mentioned conventional rotary head type recording and reproducing apparatus with reference to the drawings and FIGS. 6 and 7.

FIG. 6 shows the configuration of a conventional rotary head type recording/reproducing apparatus, and FIG. 7 shows the -1st signal waveforms of each part in FIG. In FIG. 6, the field period of the video signal (this is the field period Tf shown in FIG. 7).The vertical line shown in the waveform diagram of input signal 1 in FIG. 7 is the boundary point of the field period. It operates by simultaneously recording and reproducing a video signal with a periodicity and an analog audio signal without periodicity. First, send the video signal you want to record to the video modulator 1.
input to generate a video recording signal. The video modulator 1 detects the field boundary points of the input video signal and generates pulses in which the field boundary points alternately coincide with the rising and falling edges, and the head of the rotating head type recording/reproducing means 1° is generated. It is output as a first rotation reference pulse which is used as a rotation reference. During recording, this first rotational reference pulse is applied to the motor 9 via the switch 8 to rotate the head and synchronize the rotational phase with the field period of the video signal. Next, the video recording signal is applied to the switch 36, and the output signal of the switch 8 causes the head 1, which is the video head, to
Recording is performed while switching to heads 1a and 1b.

On the other hand, the head switching pulse, which is the output of the switch 8, is input to the edge detector 40, and the rising and falling edges of the head switching pulse are detected, and pulses are generated at these edges, and the first field is Output as a pulse. The first field pulse output of this edge detector is input to a multiplier 25 and multiplied to generate a first word clock having a frequency that is an integral multiple of the frequency of the first field pulse.

Also, the first field pulse is sent to the second clock generator 2.
6 and multiplies it to generate a clock which has a higher frequency than the first word clock and is synchronized with the period of the first field pulse, and outputs it as the second word clock. The first word clock and the analog audio signal are input to an analog/digital converter 3 and digitized using the period of the first word clock as a time reference for sampling. The data output of the analog/digital converter 3 is then input to the time compressor 38 at the period of the first word clock, at a rate synchronized to the period of the second word clock using the first field pulses and the second word clock, and The length is shorter than the period of the first field pulse, and the pulse is compressed to a section where there is no pulse waveform of the first field pulse (a section shorter than the period of the first field pulse that avoids the rise and fall of the head switching pulse). do. Subsequently, the output data of the time compressor 38 is input to the digital modulator 4, where it is digitally modulated and output as an audio recording signal. This audio recording signal is switched via a switch 37 to heads 2a and 2b, which are audio heads provided in the rotary head type recording/reproducing means 1o, and is added thereto for recording.

Conversely, when reproducing, the rotary head type recording/reproducing means 10
In order to make the playback speed of the playback signals from the two sets of heads equal to the processing speed of the video demodulator 6, the video demodulator 5 outputs a rotation reference pulse 2 indicating head switching timing, 9, two sets of heads of the rotary head type recording/reproducing means 10 are rotated. The above operation provides the field period (field period Tf shown in FIG. 7) in the demodulation process of the video demodulator 6.

Further, the vertical line shown in the waveform diagram of the video reproduction signal in FIG. 7 is the head switching point. ) with rotating head type recording/reproducing means 1
The time of switching of the video reproduction signal reproduced from the head 1a and the head 1b of the rotary head 10 via the switch 36 is synchronized with the time of head switching during recording, and The time point at which the audio reproduction signal reproduced via the switch 37 is switched is also synchronized with the time point at which the head is switched during recording. continue,
Heads 1a and 1b of rotating head type recording and reproducing means 1o
The reproduced signal is input to the video demodulator 5 through the switch 36 and processed in the opposite manner to that of the video modulator 1, thereby obtaining an output equivalent to the video signal input to the video modulator 1. On the other hand, the head 2a and head 2 of the rotary head type recording/reproducing means 10
The audio reproduction signal reproduced from B is inputted to the digital demodulator 6 via the switch 37, and processed in the opposite manner to that of the digital modulator 4 to produce reproduced digital data equivalent to the first recorded digital data inputted to the digital modulator 4. demodulates to. This reproduced digital data is input to the third clock generator 27, which generates a clock synchronized with the period of the data and outputs it as a third word clock. Next, the first field pulse and the third word clock are input to the time expander 39 to expand the reproduced digital data, which is the output data of the digital demodulator 6, to a length matching the period of the first field pulse, and convert the analog/digital An audio data signal equivalent to the output of the converter 3 is output. Subsequently, this audio data signal is input to the digital/analog converter 7 to obtain an output equivalent to the audio signal input to the analog/digital converter 3.

Problems to be Solved by the Invention However, in the above-mentioned configuration, the input audio data signal is
Since it is necessary to avoid the switching point of the audio head and arrange an integer number of data in each field period, the input speed of the output data of the analog/digital converter 3 is an integer multiple of the field frequency of the video signal. There is a need.

That is, since the sampling frequency of the audio signal needs to be an integral multiple of the field frequency of the video signal, the disadvantage is that the sampling frequency of the audio signal cannot be set to a frequency that does not match an integral multiple of the field frequency of the video signal. It had

In view of the above drawbacks, the present invention provides a rotary head type recording and reproducing device that can digitally record and reproduce an audio signal in synchronization with a video signal even when the sampling period of the audio signal does not match an integral multiple of the field frequency of the video signal. It is something to do.

Means for Solving the Problems In order to solve the above-mentioned problems, the rotary head type recording and reproducing apparatus of the present invention is provided with one set of video heads and one set of audio heads, each set of at least two heads, and for recording and reproducing video signals. a rotary head type recording and reproducing means for recording and reproducing video signals and audio signals in synchronization with the field period of the video signal;
inputting a head switching pulse that mutually switches between a first clock generator that generates a first clock that generates a clock and at least two heads for audio from the rotary head type recording and reproducing means; an edge detector that detects the rising and falling edges and outputs a pulse at the time of these edges; , a second clock generating a second clock having a frequency equal to an integral multiple of the field frequency of the video signal.
a clock generator, an analog/digital converter that pulse code modulates an input analog audio signal using the first clock, an output of the edge detector and a second
a data rate converter inputting a second clock and converting the data output of the analog/digital converter into data having a data rate equal to the second clock and arranged in a manner that avoids the switching point of the audio head; The output of the data rate converter is digitally modulated by inputting the second clock and the head switching pulse for audio, and the output is applied to the audio head switching pulse provided in the rotary head type recording/reproducing means. a digital modulator that inputs to one set of heads and outputs it as a signal for recording; and at the time of said reproduction,
An audio head switching pulse and a second clock from the rotary head type recording/reproducing means are input, and the reproduced signal from the set of audio heads is processed inversely by the digital modulator to be converted to the digital signal. a digital demodulator that demodulates a signal equivalent to the input signal of the modulator; a third clock generator that generates a clock whose cycle matches the reproduction cycle of the output data of the digital demodulator; and the third clock. A data rate inverse converter inputs the output of the edge detector and processes the input output data of the digital demodulator in the opposite manner to that of the data rate converter, and converts the output data of the data rate inverse converter. The configuration includes a digital/analog converter that converts input into digital/analog data.

Effect of the Invention With the above-described configuration, the present invention generates a sampling clock with a frequency that does not match an integer multiple of the field frequency of the video signal with a sampling clock, and uses the sampling clock. converts the audio signal from analog to digital, inputs the analog/digital converted data output to a data rate converter, and divides each field period of the video signal between the sampling points closest to the field period of the video signal. Converts to data that synchronizes with switching of the audio head, adds the value of the number of data words to the audio signal data as information indicating the format at the time of conversion, and records it in synchronization with the video recording signal every time the head is switched. do. Conversely, during playback, the signal played back from the audio head is demodulated by a digital demodulator, then input to a data rate inverter and output together with the audio data.The value of the number of data words added during recording is output together with the audio data. A clock whose average frequency matches the original sampling frequency and is cyclically continuous is regenerated, and only the audio data is extracted from the audio data that is intermittently reproduced every field period and is cyclically continuous. By reconverting the data into data, inputting it to a digital/analog converter, and performing digital/analog conversion, it is possible to reproduce a reproduced signal equivalent to the original audio signal.

Embodiment A rotary head type recording/reproducing apparatus according to an embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 shows the configuration of a rotary head type recording/reproducing device according to an embodiment of the present invention, and FIG. 2 shows a data rate converter 1 shown in FIG. 1.
1 shows the detailed configuration of 1.

Further, FIG. 3 shows a detailed configuration of the data rate inverter 12 shown in FIG. 1.

In Fig. 1, numeral 1 inputs a video signal to be recorded, performs modulation such as low carrier frequency modulation, outputs a video recording signal, and adjusts the head switching timing of the rotary head type recording/reproducing means to output the video recording signal. 2 is a first clock generator that generates a word clock b whose frequency is not equal to an integer multiple of the field frequency of the video signal; 3 is a first clock generator that generates a word clock b that is not equal to an integral multiple of the field frequency of the video signal; This is an analog/digital converter that inputs it as a time reference for sampling, converts the analog audio signal into analog/digital data, and outputs recorded digital data C. Reference numeral 4o designates an edge detector which inputs the head switching pulse which is the output of the switch 8, detects its rising and falling edges, generates a pulse at the time of these edges, and outputs it as a field pulse a. 26
is a second clock generator which inputs field pulse a and outputs word clock b which has a frequency that is an integral multiple of the frequency of field pulse a and is synchronized with field pulse a.

11 is the recording digital data C output from the analog/digital converter 3, the word clock b from the first clock generator 2, the field pulse a which is the output of the edge detector 40, and the first clock generator. Data rate recording conversion which inputs the word clock b from 2 and converts the recorded digital data C having the period of the word clock b into data having the data rate of the period of the word clock b and outputs it as the recorded digital data U. The device has the configuration of a data rate converter shown in FIG. 4 is a digital modulator which inputs recording digital data U, digitally modulates it, and outputs it as an audio recording signal. 8 is rotation reference pulse I and rotation reference pulse
is input and outputs the rotation reference pulse I during recording, and the rotation reference pulse X during playback.
36 is a motor which inputs the output of the switch 8 and rotates synchronously. During recording, the output of the video modulator 1 is switched between head 1a and head 1b by the head switching pulse which is the output of switch 8, and during playback. 37 is a switch that switches and outputs the output signals of the heads 1a and 1b using the head switching pulse that is the output of the switch 8, and 37 switches the output of the digital modulator 4 to the head switching pulse that is the output of the switch 8 during recording. head 2 by pulse
Output is switched between head a and head 2b, and head 2a is used during playback.
This is a switch that switches and outputs the output signals of the head 2b and the head 2b in accordance with the head switching pulse that is the output of the switch 8.

10 is a 2m head for video and audio (head 1a
, head 1b, head 2a, head 2b), and these two sets of heads are rotated by the motor 9, and the video recording signal is added to the heads 1a and 1b via the switch 36 for recording.At the same time, the audio recording signal is recorded. switch 37
Head 2a.

In addition to head 2b, recording is performed, and head 1a, head 1
The video playback signal from the head 2a is outputted as one playback signal via the switch 36, and the head 2a.

The audio reproduction signal from the head 2b is passed through the switch 37 to
This is a rotary head type recording/reproducing means that outputs as one signal. 6 outputs a rotation reference pulse X as a reference for the reproduction speed of the reproduction signal from the rotary head type recording and reproduction means 1o,
Heads 1a and 1b of rotating head type recording/reproducing means 10
A video demodulator inputs the video playback signal reproduced from the video signal via a switch 36, performs processing opposite to that of the video modulator 1, and outputs a video signal equivalent to the original video signal. 6 is a rotary head. This is a digital demodulator that inputs the reproduced audio signal from the heads 2a and 2b of the type recording/reproducing means 1o via the switch 37, demodulates it in the reverse process of the digital modulator 4, and outputs reproduced digital data U. . 27
is a third clock generator which inputs the reproduced digital data U which is the output of the digital demodulator 6, generates a clock synchronized with the period of the reproduced digital data U, and outputs it as a word clock N.

12 inputs the field pulse a which is the output of the edge detector 40 and the word clock N which is the output of the third clock generator 27, and inputs reproduced digital data U which is intermittently input in synchronization with the word clock N. This is a data rate inverse converter that performs the opposite process to the data rate converter 11 of inversely converting the data into periodically continuous reproduced digital data C, and has the configuration of the data rate inverse converter 12 shown in FIG. It is something.

7 is a digital/L/Bunalog converter which inputs reproduced digital data C and outputs an audio signal equivalent to the original audio signal.

In FIG. 2, 13 is a first counter that inputs the output of the timing corrector and word clock b as a clear input and a count clock input, respectively, and 14 is a first counter that inputs the output of the first counter 13 and the first shift input. Input data for each output of register 15.

The shift register 16 is a first latch that is input as a latch clock input, and the shift register 16 is a first shift register that inputs a field pulse a and a word clock b, which are the outputs of the edge detector 40 in FIG. 1, and outputs a clear pulse d. The register 16 is a first register that inputs recording digital data C, a word clock b, a first color address, a write clock, a read address, and a read clock to read out time axis conversion data. 17, a word clock n and a clear pulse m, which is the second pulse output from the first pulse generator 19, respectively.
A second counter 18 inputs as a count clock and a clear pulse, and 18 inputs a switching pulse, which is the first pulse output from the first pulse generator 19, as a switching control pulse, and two data inputs. 19 is a second selector that switches and outputs the time axis conversion data and recording word number data that are the output of the first memory circuit 16, and 19 inputs the field pulse a and switches it as the first pulse output. This is a first pulse generator that outputs a clear pulse m as a second pulse output.

In FIG. 3, 28 is a second delay device that inputs and delays field pulse A, which is the output of edge detector 4o in FIG. 1, and outputs it as field pulse M.
21 is a second latch which inputs the field pulse M, which is the output of the second delay device 28, as a latch clock and latches the reproduced word number data from among the reproduced digital data U input as data input; The output field pulse M and word clock N of the latch 2o of 2 are input as the number of outputs and the clear pulse is input, respectively.

22 is a third counter that is input as a count clock, and numeral 22 is a input signal between the reproduced digital data U and the third counter 21.
The count output of the fourth counter 23 and the word clock B which is the output of the voltage controlled oscillator 30 are used as write data input and write address, respectively.

A second memory circuit inputs a write clock, a read address, and a read clock, and reads and outputs reproduced digital data C, and 36 inputs a field pulse M, which is the output of the second delay device 28. 29 is a third latch that inputs the field pulse 2 as a latch clock and uses the data output of the second latch 20 as a data input and latches it. , 23 is a fourth counter that inputs the output of the second latch 20 as a count input and continuously counts the word clock B, which is the output of the voltage controlled oscillator 30, as a count input;
1 is a phase comparator which inputs the carry pulse output of the fourth counter 23 and the field pulse Z which is the output of the third delay device 35 and outputs a voltage signal proportional to the phase difference; 30 is a phase comparator; This is a voltage controlled oscillator which inputs the output of the generator 31, oscillates a clock having a frequency proportional to the input voltage, and outputs it as a word clock B.

The operation of the rotary head type recording/reproducing apparatus constructed as described above will be explained below with reference to FIGS. 4 and 5.

First, Figure 4 shows each part of Figure 1, a, b, c,
This shows a waveform diagram of the signals marked with d..., and Figure 6 shows the waveforms of each part of Figure 1, such as λ, B, C, D...
This shows a waveform diagram of signals marked with . In FIG. 1, a first clock generator 2 generates a word clock b shown in FIG. 4 having a frequency that is not equal to an integral multiple of the field frequency of the video signal, and this word clock b is As a reference, the audio signal is digitized by analog/digital converter 3, and
The data is converted into recorded digital data C shown in the figure. The read and recorded digital data C, word clock b, and field pulse a are input to the data rate converter 11. On the other hand, the rotational reference pulse X from the video modulator 1 is input to the edge detector 40 via the switch 8, the rising and falling edges of the rotational reference pulse X are detected, and a pulse is generated at the point of the edge. A field pulse a shown in FIG. 4 a is output. The field pulse a, which is the output of the edge detector 49, is input to the second clock generator 26 to generate a word clock n shown in FIG. 4, in which the edges of the field pulse a are synchronized by frequency multiplication.

The detailed operation of the data rate converter 11 shown in FIG. 1 will be explained using FIG. 2.

Mass, field pulse a 1st shift register 1
6 and input the field pulse a as shown in FIG.
A clear pulse e is generated at a certain point in time when the word clock b located immediately after the word clock b generates a clear pulse e. Each time this clear pulse e occurs, the first counter 13 is cleared, and the word clock b is set to the first counter 13.
It is counted by the counter 13. The count output of the first counter 13 is input as data to the first latch 14, and the first counter 13 uses the clear pulse e as the latch clock.
latches the count value immediately before being cleared by the clear pulse e. The output of the first latch is equal to the number of word clocks b within the generation interval Ti of the clear pulse e. That is, as shown in FIG. 4, during the Ti-1 period, n0+1. Ti
n in period. , no-1 in Tt+1 period...
・The value is .

On the other hand, the field pulse a is input to the first pulse generator 19 at the position shown in the clear pulse m and the switching pulse t in FIG. 4 within the recording field period Tf, and is synchronized with the word clock n. A clear pulse m and a switching pulse are generated and output. Clear pulse m and word clock n are respectively input as clear pulses to the second counter 17.

As a clock pulse input, count while the clear pulse m is at a high level, and read the record address 0 as shown in Figure 4.
occurs. The word clock b and the count output of the second counter 17 are input as the write clock and write address of the first memory circuit 16 to write the recording digital data C, and the word clock n and the output of the second counter 17 are inputted as the write clock and write address of the first memory circuit 16, respectively. each of the first memory circuit 16
is input as a read clock and a read address, the data is read out, and time axis conversion data r shown in FIG. 4 within the recording field period Tfr is output. The time axis conversion data r and the word count data V, which is the output of the first latch 14, are input to the second selector 18, and the first
Using the switching pulse, which is the first pulse output of the pulse generator 19, as a switching control pulse, the word number data V is added to the time axis converted data r at the beginning, as shown in the waveform of the recorded digital data U shown in FIG. The recorded digital data U is output in addition to the recorded digital data U.

The explanation will be continued by returning to FIG. Subsequently, the recording digital demodulator U which is the data output of the data rate converter 11
is input to the digital modulator 4 to form the audio recording signal W shown in FIG. 4, which is input to the two audio heads 2a and 2b provided in the rotary head type recording/reproducing means 1o for recording.

Conversely, in the case of reproducing, the video demodulator 5 generates a rotation reference pulse X shown in FIG. In addition to the motor 9 via the switch 8, the rotating head type recording/reproducing means 1 is connected to the processing speed of the video demodulator 6.
The rotation of the two sets of heads provided at
The video reproduction signal W shown in FIG. In addition, the audio reproduction signal reproduced from the heads 2a and 2b provided in the rotary head type recording/reproducing means 1o is inputted to the digital demodulator 6 and processed in the opposite manner to that of the digital modulator 4.
output as reproduced digital data U with a waveform equivalent to the input signal.

Furthermore, this reproduced digital data U is input to a third clock generator 27 to generate a clock synchronized with the reproduced digital data U, and a word clock N shown in FIG.
Output as . Subsequently, the reproduced digital data U, word clock N, and field pulse a are input to the data rate inverter 12.

The data rate inverter 12 in FIG. 1 will be explained using FIG. 3.

First, as shown in the waveform diagram of the reproduced digital data U in FIG. 6, in order to detect the number of words in the reproduced digital data U (the hatched part in the reproduced digital data U in FIG. 6). , field pulse A
is input to the second delay device 28, and the field pulse A is delayed until the time point indicated by the field pulse M in FIG. Let it be field pulse M.

The field pulse M output from the second delay device 28 is inputted to the second latch 2o as a latch clock, and the reproduced digital data U is inputted to the data input of the second latch 20 to latch the word number data V. . Next, the third counter 2 uses the output of the second latch 2o as the count number.
1, field pulse M and word clock N are respectively input as the clear input and count clock input of the third counter 21, and the audio data ( Fifth
n0 pieces of reproduced digital data U in the figure.

The reproduction write address 0 shown in FIG. 5 is generated as the output of the counter 21 in FIG. 3 in synchronization with the data portions marked with n0+1, n0, no-1, etc.).

On the other hand, the output of the second delay device 28 is input to the third delay device 35, delayed until the time point shown as field pulse 2 in FIG. 6, and outputted as field pulse Z. Furthermore, the second
The output of the latch 2o is input to the data input of the third latch 29, and the field pulse Z, which is the output of the third delay device 36, is latched as a latch clock. The field pulse Z and the carry pulse output of the fourth counter 23, which will be described later, are input to the phase comparator 31 and converted into a voltage signal proportional to the phase difference, and the voltage signal output of this phase comparator 31 is input to the voltage controlled oscillator. 3o, the reproduction field period (Tf) indicated by the field pulse Z is input.

A periodically continuous word clock B shown in FIG. 5 is generated which is proportional to the phase difference between the period of the carry pulse and the period of the carry pulse. This word clock B is inputted to the fourth counter 23 as a count clock, and is further inputted to the third latch 23.
The output of step 9 is input as a count number, and the clock count is repeated a number of times corresponding to the value of the input count number to perform a periodic continuous count. At the same time, the fourth counter 23 generates and outputs a carry pulse E shown in FIG. 6 at the end of counting every time it repeats a count equal to the output value of the third latch 29.

By the configuration of the fourth counter 23, the phase comparator 31, and the voltage controlled oscillator 30 that operate as described above, a word clock whose frequency is the time average value of the time series values of the reproduced word count data is created. B is generated, and the frequency of the word clock B is approximately equal to the frequency of the word clock b generated by the first clock generator 2. Subsequently, the output of the third counter 21 and the word clock N are input to the second memory circuit 22 as a write address and a write clock, respectively, and the data input to the data input of the second memory circuit 22 is shown in FIG. The output of the fourth counter 23 and the word clock 8 are written.
are respectively input to the second memory circuit 22 as a read address and a read clock, and the data is read out and output.

The data read from the second memory circuit 22 is periodically continuous data synchronized with the word clock B, and becomes reproduced digital data C shown in FIG.

Next, referring back to FIG. 1, the explanation will be continued. The reproduced digital data C outputted from the data rate inverse converter 12 as described above is input to the digital/analog converter 7 to obtain a reproduced output equivalent to the original audio signal.

As described above, according to this embodiment, the first clock generator 2 is provided independently to generate the first clock having a frequency that is not equal to an integral multiple of the field frequency of the video signal, and to generate the first clock. The audio signal QzL '2j, knee') is transformed, and the audio data signal that is the conversion output is the fourth
As shown in the recorded digital data C in the figure, the data rate converter 1
1 and divides it at the boundary point of the audio data word that is closest to the period of field pulse 1 of the video signal, creating a new data group (hereinafter referred to as a data frame), and at the same time dividing the data for each data frame. As information indicating the number of words of data in a frame, the number of words data is placed at the beginning, followed by audio data corresponding to the value of the number of words data, and the frequency is set at an integral multiple of the field pulse a and a frequency higher than the word clock b. The data is converted into data whose word period is matched to the period of the second clock. Therefore, the output data of the data rate converter 11 is transferred to the rotary head type recording/reproducing means 1 which synchronously records the video signal.
Since the phase matches the switching of the two audio heads installed at 0, the output data of the data rate converter 11 is input to the digital recording processor, converted to an audio recording signal, and then converted into a video signal and an audio signal. are recorded at the same time.

Conversely, when reproducing an audio signal, the audio reproduction signal, which is reproduced in synchronization with the video reproduction signal, is demodulated in the same manner as in the conventional example to create the same time sequence as the output data signal of the data rate converter 11. After the data has been reproduced, it is input to the data rate inverse converter 12, and the number of words data added to the data reproduced every field period is detected.
A cyclically continuous fourth clock is generated from that value, and the audio data reproduced every field period is inversely converted into cyclically continuous data with the word period matched to the period of the fourth clock. The output data of the data rate converter 11 is input to the digital/analog converter 7 to reproduce the original audio signal.

By providing the data rate converter 11 and the data rate inverse converter 12 as described above, it is possible to convert data obtained by digitizing an audio signal into data synchronized with the field period of the video signal, record it, and reverse convert it during playback. It is possible to record and play back video signals and digitally record and play back audio signals.

Effects of the Invention As described above, the present invention provides a data rate converter and a data rate inverse converter to convert audio data that is not synchronized with the field period of a video signal into data that is synchronized with the field period of the video signal. By recording and reproducing the data number information in the data frame formed with a break at the same time, the field period of the video signal fluctuates, resulting in a difference between the video signal processing speed and the audio signal digitization processing speed. Even if a processing speed deviation occurs, the audio signal is digitally processed and recorded by following the deviation,
It is possible to reproduce a signal equivariant to the original audio signal.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a rotary head type recording/reproducing apparatus according to an embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of a data rate converter according to this embodiment, and FIG. A block diagram showing the detailed configuration of the data rate inverter of the same embodiment, FIG. 4 is a signal waveform diagram of each part shown in FIG. 1, FIG. 5 is a signal waveform diagram of each part shown in FIG. 1, and FIG. The figure is a block diagram of a conventional rotary head type recording/reproducing device, and a signal waveform diagram of each part in FIG. DESCRIPTION OF SYMBOLS 1...Video modulator, 2...First clock generator, 3...Analog/digital converter, 4...Digital modulator, 5・・・・・・
Video demodulator, 6...Digital demodulator, 7...
...Digital/analog converter, 8...
Switch, 9... Motor, 10... Rotating head type recording/reproducing means, 11... Data rate converter, 12... Data rate inverse converter, 1
3...First counter, 14...First counter
latch, 16... field first shift register, 16.
...First memory circuit, 17...Second counter, 18...First selector, 19...
...First pulse generator, 2°...Second latch, 21...Third counter, 22...
... second memory circuit, 23 ... fourth counter, 24 ... phase-locked loop oscillator, 26 ... second clock generator, 27.・
...Third clock generator, 28...Second
delay device, 29...Third latch, 3o...
...Voltage controlled oscillator, 31... Phase comparator,
32... Second shift register, 33...
...Second R8-flip-flop, 34...
1st R3-Free, Pflop, 35...3rd
delay device, 36...switch, 37...
·switch.

Claims (3)

[Claims] (1) A rotary head type recording/reproducing means that includes a set of at least two heads for video and one set for audio, and records and plays back video signals and audio signals in synchronization with the field period of the video signal. , a first clock generator for generating a first clock having a period not equal to an integer fraction of the field period of the video signal, and at least two heads for audio from the rotary head type recording/reproducing means. an edge detector which inputs a switching pulse to the mutually switching head, detects its rising and falling edges, and outputs a pulse at the time of those edges; a second clock generator that generates a second clock having a frequency higher than the oscillation frequency of the first clock generator and equal to an integral multiple of the field frequency of the video signal; an analog/digital converter for pulse code modulating an analog audio signal obtained by pulse code modulation, and inputting the output of the edge detector and the second clock, and making the data output of the analog/digital converter equal to the second clock. a data rate converter that converts the data into data having a data rate and having an arrangement that avoids the switching point of the audio head; a digital modulator that digitally modulates the output of the converter and outputs the output as a signal for inputting and recording to a set of audio heads provided in the rotary head type recording and reproducing means; An audio head switching pulse and a second clock from the rotary head type recording/reproducing means are input, and the reproduced signals from the set of audio heads are processed inversely by the digital modulator to be converted to the digital signal. a digital demodulator that demodulates a signal equivalent to the input signal of the modulator; a third clock generator that generates a clock whose cycle matches the reproduction cycle of the output data of the digital demodulator; and the third clock. A data rate inverse converter inputs the output of the edge detector and processes the input output data of the digital demodulator in the opposite manner to that of the data rate converter, and converts the output data of the data rate inverse converter. A rotary head type recording and reproducing device comprising a digital/analog converter for inputting data and converting it into digital/analog. (2) The data rate converter includes a first shift register which inputs the clock output of the first clock generator and the output of the first pulse generator as a shift clock and a shift input, respectively, and the first shift register. a first clock that counts the first clock output with the output of the register as a clear input;
a first latch that uses the output of the first shift register as a latch pulse and the count output of the first counter as a data input, and a head switching pulse for audio from the rotary head type recording/reproducing means. and the output of the first latch, and each time an output pulse of the edge detector comes, a first pulse is generated after the output pulse, and a second pulse is generated after the second pulse. a first pulse generator that takes a first pulse output of the first pulse generator as a clear input, and a second counter that counts a clock output of the second clock generator; the count output of the counter, the first clock, the count output of the second counter, and the second
a first memory circuit into which the output data of the analog/digital converter is written by inputting the clocks of the analog/digital converter as a write address, a write clock, a read address, and a read clock, respectively; Input the pulse output of 2 as a switching control pulse,
a first selector that switches and outputs the data output of the first latch and the read data output of the first memory circuit, and the output of the first selector is set as the output of the data rate converter. A rotary head type recording/reproducing device as claimed in claim 1. (3) The data rate inverse converter includes a first delay device that inputs and delays the output pulse of the edge detector, uses the output of the first delay device as a latch clock, and uses the data output of the digital demodulator as a latch clock. a second latch as a data input, a clear input for the output of the first delay device, the clock output of the third clock generator, and the output of the second latch, respectively;
a third counter that has a clock input and a preset data input, starts counting the clock input every time a clear input is input, and stops counting when the count value matches the value of the preset data input; and the first delay. a second delay device that inputs and delays the output of the third delay device; a third latch that latches the data output of the second latch using the output of the third delay device as a latch clock; and the second delay device. a phase comparator that inputs the output of the counter and the carry pulse output of the fourth counter and outputs a voltage signal proportional to the phase difference; and a clock that inputs the output of the phase comparator and has a frequency proportional to the input voltage. a voltage controlled oscillator that oscillates;
The output of the voltage controlled oscillator and the data output of the third latch are respectively used as a clock input and a preset data input, and when the count value matches the value of the preset data input, a carry pulse is output and at the same time the next preset data is input. a phase-locked loop oscillator configured with a fourth counter that presets a value and repeats counting; a second memory circuit that writes the output data of the digital demodulator using the count output of the digital demodulator and the output of the voltage controlled oscillator as a write address, a write clock, a read address, and a read clock, respectively; 2. The rotary head type recording and reproducing apparatus according to claim 1, wherein the read data output is the output of the data rate inverse converter.