JPS6260396A - Time base compression and expansion device for recording and reproducing device - Google Patents

Abstract

PURPOSE:To simplify a circuit constitution by compressing two types of information signals in terms of time base so as to make a sequential signal, recording and reproducing said signal and conversely expanding it in terms of time base. CONSTITUTION:A color difference signal R-Y arriving at an input terminal 1 is switched and connected to 1.5H at a repeated frequency fH/3, while a color difference signal B-Y arriving at an input terminal 2 is supplied to switches 41-43 through a 0.5H delay circuit 6. CCDs 71-73 execute writing actions at every 0.5H, and two CCDs simultaneously execute reading actions without fail. In such a way, a 0.5H delay circuit 12 is installed on the transmission line of the reproduced color difference signal R-Y, whereby the color difference signal R-Y synthesized with its time base returned can be taken out of an output terminal 13. Simultaneously, from a changeover switch 10 to an output terminal 14 the color difference signal B-Y is taken out whose time base is returned to its original and which is synthesized in time series in the original order. In terms of two types of color difference signals, signals on the same line are simultaneously taken out.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a time axis compression/expansion device for a recording/reproducing device.
In particular, in a magnetic recording/reproducing device, two information signals are compressed on the time axis and then recorded sequentially as signals, and during playback, this sequential signal is expanded on the time axis to separate the original two information signals. This invention relates to a compression and decompression device.

Conventional technology Two information signals whose time axes have been expanded are synthesized alternately in time series at regular intervals to create a sequential signal, which is modulated using a predetermined modulation method and then recorded on a recording medium. As a recording and reproducing method, the time axis of the sequential signal obtained by demodulating the signal is extended, thereby returning it to the original time axis, and obtaining two separated information signals. In some broadcasting camera-integrated VTRs and the like, a color signal recording and reproducing system of a component recording type in which a luminance signal and a color signal are recorded on separate tracks is used.

This device is transmitted at the same time as the luminance signal schematically shown in Fig. 5 (△), and the two
After compressing the time axes of the species color difference signals (R-Y) and (B-Y) by 1/2, they are synthesized alternately in time series and are schematically shown in the same figure (C). Sequential signals such as FIG. 6(A) shows the waveform of the above luminance signal, and FIG. 6(B) shows the waveform of the above luminance signal.
shows the waveform of the above sequential signal, and the start point of time axis compression is located 5.3 μs after the 40th edge of the horizontal synchronization signal 1''S. Advantageously, the above-mentioned sequential signals are frequency modulated and then recorded on the magnetic tape by a rotating head. Also,
During this recording, a brightness signal frequency-modulated by another rotary head is recorded simultaneously with the frequency-modulated sequential signal (FM sequential signal) and forming a separate track.

During reproduction, two recording track groups are scanned separately and simultaneously, and the above-mentioned FM sequential signal and FM luminance signal are reproduced separately and simultaneously.

After the above-mentioned FM sequential signal is FM demodulated, the time axis is expanded twice and returned to the original time axis, and the reproduced color difference signals RY and BY are extracted in parallel by being separated.

Problems to be Solved by the Invention However, in the above-mentioned conventional magnetic recording and reproducing apparatus, the recording system is provided with means for sequentially compressing the two types of color difference signals in the time axis, expanding the reproduced signal in the time axis, and , it is necessary to provide a means for separating two types of color difference signals in the reproduction system, which requires a large number of parts, and the circuit configuration is complex and expensive because it uses digital memory to compress and expand the time axis. There were some problems.

Therefore, the present invention provides a time axis compression/expansion device for a recording/reproducing device that solves the above problems by using three analog delay elements to perform both time axis compression and time axis expansion in one circuit. The purpose is to provide.

Means for Solving the Problems The time axis compression/expansion device of the recording/reproducing device according to the present invention is as follows:
a first switching means for selectively outputting one of the two types of information signals and the reproduction sequential signal to each of the three transmission lines; and after writing the signal from the first switching means based on a clock pulse of a first frequency. a time base conversion circuit having a total of three analog delay elements, one for each transmission line, which read out each other in a time-divisional manner based on clock pulses of a second frequency, and one of the three analog delay elements;
a second switching means for selectively outputting the readout output signals of the three analog delay elements; and a second switching means for selectively outputting the read output signals of the three analog delay elements, and the two signals that are time-axis expanded and read simultaneously from the three analog delay elements 212a are switched in parallel at regular intervals. a third switching means to output, one of the transmission paths for the two types of information signals supplied to the first switching means, and the other of the transmission paths for the two types of information signals taken out from the third switching means. It consists of a delay circuit for phase matching provided respectively.

At the time of action recording, the first switching means selectively outputs two types of information signals to three transmission paths separately, and the second
frequency is n times the first frequency (n is a natural number)
is selected, and the time base conversion circuit performs time base compression by a factor of 1/n. As a result, the time axis of the 22 types of information signals from the second switching means is compressed to 1/n times, and sequential signals obtained by being alternately synthesized in time series are extracted. On the other hand, during reproduction, the first switching means selectively outputs the sequential signals to the three transmission paths, and the second frequency is selected to be 1/n times the first frequency, and the time axis is The conversion circuit performs n-fold time axis expansion. As a result, the two types of information signals returned to the original time axis by the third switching means are separated and output.

Embodiment Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a block system diagram of an embodiment of the apparatus of the present invention. In the figure, input terminals 1 and 2 have color difference signals RY as an example of two types of information signals.

B-Y are respectively inputted, while sequential signals to be described later are inputted to the input terminal 3. The color difference signal RY is sent to the first switching means S.
1, the color difference signals B-YG and tO15H are supplied to the switches 41-43 through the delay circuit 6, and the sequential signals is I71
! It is supplied to opening switches 51 to 53, respectively. here,
The time axis compression/expansion device of the present invention is used, for example, in a recording/reproducing apparatus having a configuration as shown in FIG. 4. First, the configuration of this recording/reproducing apparatus will be explained.

In FIG. 4, during recording, a luminance signal is input to the input terminal 20, and color difference signals R-Y,
B and Y come in respectively. The luminance signal that has entered the input terminal 20 is sent to the switch 2 connected to the contact REC side during recording.
3 to the synchronization signal separation circuit 24, while F
MI adjuster 25. Recording amplifier 26. During recording, the rotating head 28 is
supplied to On the other hand, the color difference signal R-Y that has entered the input terminal 21 is supplied to the synchronization signal addition circuit 29, where it is added with the horizontal synchronization signal from the synchronization signal separation circuit 24.
The signal is supplied to the input terminal 1 of the time axis compression/expansion circuit 30, which constitutes the main part of the present invention. Further, the color difference signal B-Y from the input terminal 22 is supplied to the input terminal 2 of the time axis compression/expansion circuit 30.

On the other hand, the horizontal synchronization signal taken out from the synchronization signal separation circuit 24 is supplied to a clock generator 31 and a control pulse generator 32, respectively. A clock generator 31 generates a high frequency clock that is phase-synchronized with the horizontal synchronizing signal and supplies it to a control pulse generator 32 and a clock controller 33, respectively. The control pulse generator 32 generates control pulses for controlling the switching of second and third switching means S2 and S3, which will be described later, of the time axis compression/expansion circuit 30, respectively, to the time axis compression/expansion circuit 30 and the clock controller 33. supply clock controller 3
3 are four types of clock pulses CK1.3 to be described later. GK2. C
K3 and CK4 are generated respectively, and the frequency is set to f.
S or fs/2 at a predetermined timing and supplies it to the time axis compression/expansion circuit 30. Further, a switching control signal from the input terminal 34 is supplied to a time axis compression/expansion circuit 30, which switches a first switching means S1, which will be described later, depending on whether recording or reproduction is being performed.

As will be described later, during recording, the time axis compression/coupling circuit 30 compresses the time axis of the color difference signals R-Y and B-Y by 1/2, and then sequentially compresses them in time series every 1/2 horizontal scanning period. are combined to generate a sequential signal, and this sequential signal is output to the output terminal 9.
Output to. This sequential signal is sent to the FM modulator 35. Recording amplifier 36. During recording, the signals are supplied to the rotary head 38 through the switches 37 connected to the contact REC side.

The rotating heads 28 and 38 each consist of a pair of rotating heads mounted opposite to each other on the rotating surface of a rotating body such as a rotating drum, and are mounted close to each other. Further, the magnetic tape 39 is wound diagonally around the above-mentioned rotating body over an angular range of over 180 degrees, and is caused to travel at a predetermined constant speed. As a result, a track in which a frequency modulated luminance signal (FM luminance signal) is recorded by the rotary head 28 and a track in which an FM sequential signal is recorded by the rotary head 38 are simultaneously and separately formed on the magnetic tape 39. , and thereafter two tracks are formed for each field.

Next, the operation during reproduction will be explained. During reproduction, the switches 23, 27 and 37 are respectively connected to the contact PR side. As the rotary heads 28 and 38 scan the two tracks separately, the rotary head 28 reproduces an FM luminance signal, and at the same time, the rotary head 38 reproduces an FM sequential signal. The FM 1 degree signal reproduced by the rotary head 28 is sent to the switch 27. preamplifier 40
The signal is supplied to the FM demodulator 41 through the FM demodulator 41, where it is FM demodulated into a reproduced luminance signal and then output to the output terminal 42. On the other hand, the FM sequential signal reproduced by the rotary head 38 is transmitted to the switch 37. FM demodulator 4 through preamplifier 43
4, where it is FM demodulated and made into a reproduction sequential signal, and then supplied to the input terminal 3 of the time axis compression/expansion circuit 30, while the synchronizing signal is sent to the m circuit 2 through the switch 23.
4, where the horizontal synchronizing signal added during recording is separated and extracted, and then supplied to a clock generator 31 and a control pulse generator 32, respectively.

Control pulse generator 32. clock con l-mouth-
Each output pulse of the controller 33 is supplied to a time axis compression/expansion circuit 30, respectively.

As a result, the time axis compression/expansion circuit 30 doubles the time axis of the input reproduction sequential signal, as will be described later, and separates the reproduction color difference signals R-Y and B-Y from the output terminal 1.
3.14 respectively in parallel and continuously. The reproduced color difference signal R-Y taken out from the output terminal 13 is supplied to a synchronization signal sampling circuit 45, where the horizontal synchronization signal added during recording is extracted, and then outputted to the output terminal 46. In addition, the reproduced color difference signal B taken out from the output terminal 14
-Y is output to the output terminal 47.

Returning to FIG. 1 again, during recording, the changeover switches 41 to 43 constituting the first changeover means S+ are activated by a symmetrical square wave (control pulse) with a repetition frequency fH/3 for a 1.5 horizontal scanning period. The opening/closing switches 51 to 53 are connected at all times (1, 5l-1), and the opening/closing switches 51 to 53 are always open. Color difference signal R-Y coming into input terminal 1
is supplied to the switches 41 to 43, while the color difference signal B-Y input to the input terminal 2 is delayed to 0 by the 0.5 day delay circuit 6.
．． After being delayed for 5 days, it is supplied to switches 41-43.

The switch 41 is the (3 to -2)th switch (k is 1, 2)
．． 3. ...) line color difference signal R-Y and (3 to -1
) is switched every 1.5 days to alternately select and output the color difference signals B-Y of the th line.

Similarly, the switch 42 alternately selects and outputs the color difference signal B-Y of the (3rd -1)th line and the color difference signal R-Y of the 3rd line, and the switch 43 selects and outputs the color difference signal B-Y of the (3rd -1)th line. The color difference signal R-Y of the th line and the color difference signal B-Y of the third line are alternately selected and output.

The output color difference signal of the switch 41 is a charge coupled device (COD) as an example of an analog delay element.
7+, and each output color difference signal of the switches 42 and 43 is supplied to C0D72.7s. These three C's
0D7+ to 73 are the control pulse generators 3 described above.
2. Together with the clock controller 33, it constitutes a time axis conversion circuit. CCD7+, 72 and 73 are supplied with clock pulses CK1. The delay time is variable in inverse proportion to the repetition frequency of CK2 and CK3, and the capacity (number of stages) is selected to have a delay time of, for example, 0.5H when the clock pulse frequency is fs. - As an example, change the number of stages from C0D7+ to 730 to 455
step, the frequency fs is the horizontal scanning frequency f l-
Approximately 14M, which is a frequency 910 times 1 (=455X2)
Hz.

During recording, the clock pulses CKI, CK2, and CK3 have a frequency of fs/2 for the 1H period and fS for the next 0.5H period, as schematically shown in Figure 2 (A>, (B), and (C)). and f s /
The timing of switching from 2 to fS is clock pulse C.
K2 is 0.5H slower than CK1 and 0.5H slower than CK3.
) (selected at an early timing. Now, the color difference signal RY from input terminal 1 is shown in Figure 2 (D) as A in 1H units.
1. The output color difference signal QB-Y of the 0.5 day delay circuit 6 is schematically shown as A2゜..., and the output color difference signal QB-Y of the 0.5 day delay circuit 6 is shown schematically as B+, B2,... in 1l1 units in the same figure (E). shall be. The signal A1 of the first 1H period of the color difference signal R-Y is supplied to C0D7+ through the changeover switch 41, where it is supplied to C0D7+ by the clock pulse CKI of frequency f s /2.
When the contents of CD7+ (all stages) are completely written, the frequency of the clock pulse CKI switches to fS, so the time axis is multiplied by 1l2 during the 0.5H period in the first half of the 2H when CK1 is fS. It is compressed and read out as signal A+'.

Further, the signal B1 between the first 1l and Ill of the input color difference signal B-Y is taken out from the 0.5-day delay circuit 6 with a delay of 0.5H after the signal A1, and is supplied to the C0D72 through the switching switch f/42. Then, after the clock pulse CK2 of frequency fs/2 has completely written to the full capacity ω of the CCD 72 over 1H, the clock pulse OK2 reaches t'
The time axis is compressed by 1l2 times during the 0 and 5H periods, which is s, and all are read out as the signal B+'. Furthermore, at a point delayed by 0.5)-1 from the above signal B+, that is, CCD7+
The 2H-th signal Δ2 of the color difference signal R-Y, which has entered the input terminal 1 for a period of 11'' from the point in time when the signal A+' starts reading out the signal A+', is supplied to the CCD 73 through the changeover switch 43, where the frequency fs/ When all data is written to the full capacity of the CCD 73 by IH using the clock pulse CK3 of 2, the frequency of CK3 is switched to fS.
The time axis is compressed by 1l2 times from the CCD 73, and all the signals are read out as a signal Δ2' over 0.5 days.

Thereafter, in the same manner as above, changeover switch 41 is used to select C0.
D7+ has B2. △a, Bs, Aa.

B8. . . . Color difference signals for each 1H period are supplied to the CCD 72 by the changeover switch 42. Δ3°B4,
The color difference signals of As, By, A9, . . . for each 1H period are supplied, and the CCD 7 is
3 has B3, As, B6, As, 89
, . . . are supplied with color difference signals for each 1H period, and the CC
D7+ to 73 perform a write operation based on a clock pulse of frequency fs/2 for a period of 1H, and then perform a read operation based on a clock pulse of frequency fS for a period of 0.5H, and repeat the above read operation. is performed in a time-sharing manner in the order of CCD 71→72→73→71→...

Figure 2 (F), (G) and (H) are CCD7+.

The above-mentioned operations of 72 and 73 are schematically shown, where W indicates between 1H)11] where a write operation is performed, and R indicates between 0 and 5Hjl1 where a read operation is performed.

As can be seen from Figure 2 (F), (G) and (+-1), the time axis is changed from CCD 7+ to 73 by 1l every 0.5)-1.
The color difference signal compressed twice and read out in a time-division manner is
The signal is supplied to the changeover switch 8 constituting the second changeover means S2.

The changeover switch 8 is switched and connected every 0.5 days by a control pulse of frequency fH so as to selectively output the read output signal of one COD whose clock pulse frequency is fS among the CCDs 7+ to 73 to the output terminal 9. As a result, as schematically shown in FIG. 2 (1), the output terminal 9 is
The two types of color difference signals have their time axes compressed by 1l2, and
Sequential signals synthesized in time series are output alternately every 0.5 days.

Next, to explain the operation during playback, during playback, the open/close composition switches Er+~53 are always closed, and no color difference signals are input to input terminals 1 and 2, so CCD7+
, 72 and 73 have input terminals 3 (D
) is the reproduction sequential signal schematically shown in the opening/closing switch 5+.
, 52 and 53, respectively. Clock pulse CKI.

CK2 and CK3 are shown in FIG. 3 (Δ) during playback.

As schematically shown in (8) and (C), the frequency is switched at every 1.5H period, such that the frequency during 05H is fs and the next 1H period is fs/2.
And the switching timing from frequency fs to fs/2 is C
K2 is generated 0.5H later than CK1 and 0.5H earlier than CK3. In addition, clock pulse GK2
The timing at which the frequency changes from fs to fs/2 is the time axis compressed color difference signal B+' that constitutes the reproduction sequential signal.
The timing is set to match the timing of switching from A2' to A2'. CCD7+ reads out the input reproduction sequential signal based on clock pulse CK1, and similarly reads C0.
D72 and 73 convert the input reproduction sequential signal into a clock pulse C.
Read after writing based on K2 and CK3. C0
The output signal of D7+ is supplied to the contacts 10a and 11a of the changeover switches 10 and 11 constituting the third changeover means S3, and the output signal of the CCD72 is supplied to the changeover switches 10 and 11.
The output signal of C0D73 is supplied to contacts 10G and 11C, respectively. The changeover switches 10 and 11 are controlled by control pulses of frequency fH/2, and both of them change the CCD'l every 1H.
It is cyclically switched to selectively output each readout signal in the order of 1→72→7I→73→..., and the changeover switch 1o is set to C where the changeover switch 11 outputs the readout signal.
The same COD as the OD is connected at a timing delayed by 1.5H.

That is, the changeover switch 10 is connected to select and output the CCD7+ output signal 1.58 times after the changeover switch 11 starts selectively outputting the output signal of the CCD7+, for example.

As a result, the signal A+' of the first 0.5H period of the incoming horn playback sequential signal is written to the full capacity of CCD7+ by clock pulse CK1 of frequency fS at 0.51-1 or rep, and then CK1 is Since the frequency is switched to fs/2, the time axis is expanded twice and read out, and 1
Read in days. During one day when the CCD 7+ doubles the time axis of the signal A+' and reads it out as the signal △1, the changeover switch 11 is connected to the contact 11a, so the output signal A1 becomes 0 through the changeover switch 11.
．． The signal is supplied to the 5H delay circuit 12. The signal B+' for the next 0.5H period of the input reproduced sequential signal is written to the CCD 72 by the clock pulse CK2 of frequency fS, and then read out at frequency fs/2. CCD 72 receives signal B+'
Since the changeover switch 10 is connected to the contact 10b during the 1H period in which the time axis is expanded twice and read out as the signal B1, this signal B1 is outputted to the output terminal 14 through the changeover switch 10.

The signal △2' that comes in the next 0.5H period of the input reproduction sequential signal is clocked by the clock pulse CK3 of frequency fS.
After everything is written to CD73, CK3 becomes frequency f.
s/2, the time axis is expanded twice, and the signal is read out from the CCD 73 for 1H period as signal @A2.

1H period during which this output signal A2 is read out (that is, 1H period immediately after CCD7+ reads out signal A1)
Since the changeover switch 11 is connected to the contacts 11a to 11c, the signal A2 passes through the changeover switch 11 and becomes 0.
．． The signal is supplied to the 5H delay circuit 12. Hereinafter, in the same manner as above, C0D71 is shown in FIG. 3(E), CCD72 is shown in FIG. 3(F), and C0D7r is shown in FIG.
After performing the write operation for a period of 0.5H, the signal whose time axis has been expanded twice is read out repeatedly for a period of one day indicated by R. As can be seen from (E) to (G) in the same figure, the CCD
7+ to 73 time-divisionally perform a write operation every 0.5i-1, and two CODs always perform a read operation simultaneously.

In this way, from the 0.5H delay circuit 12 to the output terminal 1
3, as schematically shown in FIG. 3(H), the time axis is returned to the original position, and the color difference signal R-Y which is chronologically synthesized in the original order is extracted, and this and the color difference signal R-Y are extracted. At the same time, as schematically shown in FIG. 3(I), the color difference signal B-Y is returned from the changeover switch 10 to the output terminal 14 and is returned to the later time axis and synthesized chronologically in the original order. is taken out.

In addition, when recording, the color difference signal B-Y is compared to R-Y by 0.5
Since there is a delay of
As for the different color difference signals, the signals of the same line are taken out at the same time.

Note that the present invention is not limited to the above-mentioned embodiments, and for example, when recording, the input clock frequency may be selected to be 1/m times the read clock frequency (where m is any integer greater than or equal to 3). Alternatively, a signal whose time axis has been compressed by a factor of 1/m may be taken out, and a signal whose time axis has been expanded by a factor of m may be obtained by selecting the read clock frequency to be 1/m times the write clock frequency during reproduction. Other charge transfer devices (eg, packet, brigade devices) can also be used as analog delay devices. Furthermore, the two signals to be compressed and expanded in the time axis are color difference signals RY.

It is not limited to B-Y, but may also be an I signal and a Q signal, and furthermore, combinations of ■ a brightness signal and a color signal, ■ a frequency division multiplexed signal consisting of an audio signal and a color signal and a brightness signal, ■ a color video signal and an audio signal, and other combinations. Two types of information signals may be used.

Further, the present invention can be applied to all recording and reproducing systems in which two types of information signals are compressed in the time axis and sequentially recorded and reproduced.

Effects of the Invention As described above, according to the present invention, time axis compression and time axis expansion can be performed with one circuit using an analog delay element, so the number of parts can be reduced, and moreover, it is possible to reduce the number of components and use an analog memory instead of a digital memory. Since a delay element is used, the circuit configuration is simpler, and there is no need for a separate circuit other than the analog delay element, and as a result, it can be configured at a significantly lower cost than conventional methods. It has the following.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the device of the present invention;
2 and 3 are time charts for explaining the operation of the block system illustrated in FIG. 1 during recording and reproduction, respectively; FIG. 4 is a block system diagram showing an example of a recording/reproducing apparatus having the device of the present invention; and FIG. The figure is a diagram illustrating an example of time axis compression in a conventional device, and FIG. 6 is a diagram showing waveforms of a luminance signal and a sequential signal in the conventional device. 1.2... Color difference signal input terminal, 3... Sequential signal input terminal, 51-53... Open/close switch, 6. '12・
...0.5) 11 extension circuit, 71-73...Charge...
Coupled device (COD), 9... Sequential signal output terminal, 13.14... Reproduction color difference signal output terminal, 2
0... Luminance signal input terminal, 21.22... Color difference signal input terminal, 28.38... Rotating head, 30... Time axis compression/expansion circuit, 32... Control pulse generator, 33 ... Clock controller, 34... Switching signal input terminal, 39... Magnetic tape, 46.47.
... reproduced color difference signal output terminal, Sl... first switching means, Sl... second switching means, S3... third switching means. Patent applicant Victor Company of Japan Ltd. Figure 2 Figure 3 BI B2 B3 84 85 Figure 5 Figure 6 Indication of 1985 Patent Application No. 200325@2, Title of Invention Time Axis Compression/Expansion Device for Recording and Reproducing Device 3, Relationship to the Amendment Case Address of Patent Applicant: Moriya-cho, Kanayō-ku, Yokohama-shi, Kanagawa Prefecture, 221 3-12 Name (432) Victor Japan Co., Ltd. Representative Director and President Michi Shishi - Department 4, Agent Address 5-7-6 Kojimachi, Chiyoda-ku, Tokyo 102
, Detailed description of the invention in the specification to be amended. 7. Details of the correction [Expansion J is corrected as ``compression J'' as stated in page 3, line 13 of M.

Claims (1)

[Claims] During recording, two types of information signals are supplied, and the time axis is
/n (where n is a natural number) times, and then output the sequential signals obtained by synthesizing them alternately in time series as a recording signal, and at the time of reproduction, the reproduced sequential signals are supplied,
In a time axis compression/expansion device of a recording/reproducing apparatus that expands the time axis by n times, branches into two, and separates and outputs the two types of information signals in parallel, the two types of information signals and the reproduction sequential signal are separated. a first switching means for selectively outputting one signal to each of the three transmission paths; and a first switching means for selectively outputting one signal to each of the three transmission paths; A time base conversion circuit having a total of three analog delay elements, one for each transmission path, which read out each other in a time-sharing manner based on a clock pulse of a second frequency after writing, and among the three analog delay elements. a second switching means for selectively outputting a read output signal of one analog delay element to which a clock pulse of a second frequency is supplied; a third switching means for switching and outputting two signals in parallel at regular intervals, which are simultaneously time-extended and read out by clock pulses of two frequencies; and the two types of information supplied to the first switching means. One of the information signal transmission paths and the second information signal taken out from the third switching means.
The first switching means selectively outputs the two types of information signals at the time of recording, and the second information signal is selectively outputted by the first switching means. selects a frequency n times as high as the first frequency, and the second switching means compresses the time axis of the two types of information signals to 1/n times, and synthesizes them alternately in time series. The first switching means selects and outputs the sequential signal at the time of reproduction, and the second
is configured to select a frequency 1/n times as high as the first frequency, and separate and output the two types of information signals returned to the original time axis by the third switching means. A time axis compression/expansion device for recording/playback equipment.