JPH02240802A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To prevent a signal left unerased from being reproduced by judging a signal of a PCM area whether it is the recorded signal in relation with a video image or the signal left unerased irrelevant to the video image. CONSTITUTION:A PCM latter half area setting circuit 5 sets the latter half of a PCM area, detects an error number of a reproduced data at the area latter half and whether the PCM signal recorded in the PCM area is in relation to a video image or a signal left unerased irrelevant to the video image is judged from whether the error number is a prescribed value or over. When a new video image is recorded again on a tape with the PCM signal already recorded by using the 8-mm VCR whose PCM recording system is not set, the latter half in the PCM area is destroyed concentratingly. Thus, when the error of the reproduced data of the latter half of the PCM area is detected, even when the video area with re-recording is slightly overlapped with the PCM area, the PCM signal recorded in the PCM area is surely judged as to whether the signal is in relation with the video image or a signal left unerased.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a magnetic recording and reproducing device in which a time-base compressed PCM audio signal is recorded on an extension of a video track, such as an 8 mm VTR. , especially PCM
It relates to a judgment circuit that detects whether there is an unerased PCM audio signal in the area.

[Summary of the invention]

The present invention provides a magnetic recording and reproducing device that records a time-base compressed PCM audio signal on an extension of a video track, in which the PCM audio signal is reproduced from a portion of the PCM area that corresponds to a position close to a postamble portion. By determining whether there is an unerased PCM audio signal in the PCM area from the error state in the signal,
It is possible to reliably determine whether there is an unerased PCM audio signal in the CM area.

The present invention detects a signal corresponding to a signal recorded in a postamble part in a magnetic recording/reproducing device in which a time-axis compressed PCM audio signal is recorded on an extension of a video track, and leaves the signal unerased in the PCM area. By determining whether there is a PCM audio signal of
This system is designed to ensure that there is an unerased PCM audio signal in the CM area.

The present invention detects an error in a reproduced signal in a portion of the PCM recording area near the postamble portion in a magnetic recording/reproducing device that records a time-axis compressed PCM audio signal on an extension of a video track. At the same time, by detecting the presence or absence of a signal corresponding to the signal recorded in the postamble section and determining whether there is an unerased signal in the PCM recording area, the unerased PCM audio signal is detected in the PCM area. This makes it possible to reliably determine whether or not it exists.

[Conventional technology]

8mm VTRs use an audio recording method (hereinafter referred to as
In addition to the AFM recording method (hereinafter referred to as the AFM recording method), an audio recording method (hereinafter referred to as the PCM recording method) in which a digital audio signal is compressed in the time axis and recorded in a PCM area that is an extension of the video track can be adopted.

That is, when performing PCM recording, the tape is wound, for example, 221 degrees. As shown in FIG. 6, the part where the rotating head begins to come into contact with the tape is defined as a plunge part 101,
The latter half of the entry section 101 is a preamble section 102 which is a part of a clock line synchronized with PCM data. After that is the PCM area 103 where the time axis compressed PCM signal is recorded, and this PCM area 10
After 3 is the postamble section 104, which is followed by 1
80 degrees is the video recording area 105.

A digital audio signal for one field is compressed in the time axis and recorded in the PCM area 103.

Currently, there are 8mm VTs on the market that cannot set PCM recording.
R and an 8mm VTR that can be set to the PCM recording format are on sale.

Against this background, for example, there are users who own camera-integrated 8mm VTRs for which the PCM recording method cannot be set, and stationary 8mm VTRs for which the PCM recording method can be set.

Depending on the situation, such users use either an 8mm VTR that can set the PCM recording format or an 8mm VTR that cannot set the PCM recording format0. If you are using a camera-integrated 8mm VTR for which the PCM recording format cannot be set, and want to record or edit TV programs, use a stationary 8mm VTR that can set the PCM recording format. I am using a VTR.

For such users, the PCM recording method can be set.
8mm VT where mm VTR and PCM recording format cannot be set
The tape is shared with R.

For this reason, such users may re-record new video onto a tape that has already been recorded using the PCM recording method using an 8mm VTR that cannot be set to the PCM recording method.

However, if new video is re-recorded on a tape that has already been recorded using the PCM recording method using an 8mm VTR that cannot be set to the PCM recording method, the video will be re-recorded, but the old video will be recorded in the PCM area. PCM audio signal remains. If the PCM area signal remains, there is a possibility that when the tape is played back on a PCM recordable VTR, audio unrelated to the video will be played back.

In other words, on the tape 111 recorded using the PCM method, the seventh
As shown in Figure A, the tracks T t , T z , T, .
... are recorded with video signals V+, Vz, Vs, etc., and PCM audio signals P1, Pg, Ps, etc. are recorded as an extension thereof.

When a video signal is re-recorded on this tape 111 with an 8mm VTR that cannot be set for PCM recording, as shown in FIG. V, ,V,... are new video signals VNI, Vll! % VH2..., but the PCM audio signal P in the PCM area on the extension
,,P, ,P,... remain.

For 8mm VTRs that can set the PCM recording method, PCM
A function called priority is activated.The PCM priority function automatically puts the PC
This is a function to set the reproduction mode of the M audio signal.

For this reason, as shown in Figure 7B, when a tape on which the video signal has been re-recorded but the PCM audio signal remains unerased is loaded into an 8mm VTR that can be set to the PCM recording format, The PCM priority function is activated, the PCM audio signal playback mode is set, and the old PCM audio signal unrelated to the video is played back.

Therefore, it is determined whether the PCM signal recorded in the PCM area is related to the video, or whether it is unerased and unrelated to the video, and the PCM signal recorded in the PCM area is
If it is determined that the signal is related to the video, this PCM signal is played back, and if it is determined that the PCM signal recorded in the PCM area is an unerased signal that is not related to the video. It is conceivable to reproduce an FM modulated audio signal multiplexed on a video track.

[Problem to be solved by the invention]

In order to determine whether the PCM signal recorded in the PCM area is related to video or unerased data unrelated to video, the number of errors in the PCM signal played from the PCM area is equal to or greater than a predetermined value. It is possible to detect whether

However, if the number of errors in the PCM signal played back from the PCM area is used to determine whether the PCM signal recorded in the PCM area is related to the video or an unerased signal unrelated to the video, You may not be able to make the right decisions.

In other words, if the re-recorded video area 105A slightly overlaps with the PCM area 103, as shown in FIG. The absolute number of errors in the signal will not be very large, so as mentioned above,
If it is determined from the number of errors in the PCM signal reproduced from the PCM area whether the PCM signal recorded in the PCM area is related to a video or an unerased signal unrelated to the video, a misjudgment will result. From the number of PCM signal errors, P
If you reduce the number of errors, which is the standard for determining whether the PCM signal recorded in the CM area is related to the video or the unerased signal unrelated to the video, the PCM signal can be It can be determined whether the PCM signal recorded in the area is related to the video. However, if the standard number of errors is lowered in this way, even if a PCM signal related to video is recorded in the PCM area,
If a normally occurring error occurs, it will be determined that the PCM signal recorded in the PCM area is not related to the video.

In addition, as shown in Figure 8B, the re-recorded video area 1
If 05B does not overlap with PCM area 103, P
The signal in the CM area 103 is not destroyed at all. Therefore, from the number of errors in the PCM signal reproduced from the PCM area 103, the PC recorded in the PCM area 103
It is not possible to determine whether the M signal is related to the video or an unerased signal unrelated to the video.

Please note that the currently used PCM recording cannot be set.
In millimeter VTRs, the tape is wrapped around the drum at 180 degrees, and the tape is wrapped around the drum at an angle α smaller than 180 degrees.
There are some that can be wrapped by a larger angle (180 degrees + α).

The tape is wrapped around the drum by (180 degrees + α) 8
When a video signal is re-recorded with a millimeter VTR, a state as shown in FIG. 8A is obtained. When a video signal is re-recorded with an 8 mm VTR in which the tape is wrapped around the drum by 180 degrees, the state shown in FIG. 8B is obtained.

Therefore, an object of the present invention is to provide a magnetic recording and reproducing device that can reliably determine whether a PCM signal recorded in a PCM area is related to a video or is unerased and unrelated to a video. It's about doing.

[Means to solve the problem]

The present invention detects an error in a signal reproduced from a portion near a postamble part in a PCM area in a magnetic recording/reproducing device in which a time-base compressed PCM audio signal is recorded on an extension of a video track. This magnetic recording and reproducing apparatus determines whether there is an unerased PCM audio signal in the PCM area from an error state in a signal reproduced from a part near the postamble part in the second PCM area.

The present invention detects the presence or absence of a signal corresponding to a signal recorded in a postamble section in a magnetic recording and reproducing device in which a time-axis compressed PCM audio signal is recorded on an extension of a video track, and detects the presence or absence of a signal corresponding to a signal recorded in a postamble section. There may be unerased P in the PCM area depending on the presence or absence of the signal recorded in the PCM area.
This is a magnetic recording and reproducing device that determines whether there is a CM audio signal.

The present invention detects an error in a reproduced signal in a portion near a postamble part in a PCM area in a magnetic recording/reproducing device that records a time-base compressed PCM audio signal on an extension of a video track. At the same time, the presence or absence of a signal corresponding to the signal recorded in the postamble section is detected, and the PC
Check whether there is an unerased PCM audio signal in the PCM area based on the error state in the signal reproduced from the part near the postamble part in the M area and the presence or absence of a signal corresponding to the signal recorded in the postamble part. This is a magnetic recording/reproducing device designed to determine the

[Effect]

By detecting errors in the playback data in the latter half of the PCM area, even if the video area slightly overlaps with the PCM area when re-recorded, the PCM signal recorded in the PCM area will be related to the video. It is possible to reliably determine whether it is something that has been erased or something that has nothing to do with the video.

If it is detected whether there is a signal corresponding to the signal recorded in the postamble part, even if the video area and PCM area do not overlap when re-recording, the PCM
It can be determined whether the PCM signal recorded in the area is related to the video or is unerased and unrelated to the video.

By detecting whether the error in the second half of the PCM area is greater than or equal to a predetermined value and also detecting whether a predetermined pattern of signals is detected from the postamble part, the index can be erased in the part corresponding to the postamble part. Even when a signal is being input, it can be accurately determined whether the signal in the PCM area is recorded in connection with the video or is unerased and unrelated to the video.

〔Example〕

Embodiment 2 of this invention will be explained in the following order.

a. First embodiment Second embodiment C9 third embodiment d. Fourth embodiment a. First embodiment FIG. 1 shows a first embodiment of the invention.

In an 8mm VTR, PCM is added as an extension of the video track.
An area will be established. After the reproduction signal of the second PCM area is subjected to pi-phase demodulation, it is supplied to the PCM reproduction circuit 2 from the input terminal 1 in FIG.

In the PCM recording format of an 8mm VTR, I
The CRC block consists of an 8-bit address code, eight words WO to W7 of 8 bits each, two parities P and Q of 8 bits, and a 16-bit CRC code. CRC indicates whether there is an error in each block
Detected by code. If an error occurs, the PCM reproducing circuit 2 outputs an error detection signal S0°. This error detection signal S elc is PCM
The signal is supplied from the reproducing circuit 2 to the counter 3.

From the input terminal 4 to the PCM second half area setting circuit 5, the PCM
An area signal is provided. This PCM area signal, for example, while the part corresponding to the PCM area is being played,
Become a high level.

The PCM second half area setting circuit 5 generates a detection area setting signal SIIET based on the second PCM area signal. This detection area setting signal s ext becomes high level corresponding to the latter half of the PCM area.

This detection area setting signal SDEW is supplied from the PCM second half area setting circuit 5 to the count enable terminal of the counter 3.

The counter 3 counts the error detection signal S_C1e from the PCM reproduction circuit 2 while the detection area setting signal S_BET is at a high level.

An output terminal 6 is derived from a predetermined bit of the counter 3. When the counter 3 counts a predetermined number or more, this predetermined bit becomes "1" and an output appears from the output terminal 6. The output from this output terminal 6 is used as a signal for determining whether the signal in the PCM area is recorded in connection with the video or is unerased and unrelated to the video.

In this first embodiment, the PCM second half area setting circuit 5 sets the second half of the PCM area, detects the number of errors in the reproduced data in the second half of the PCM area, and determines whether the number of errors is greater than a predetermined value. , it is determined whether the PCM signal recorded in the PCM area is related to the video or is unerased and unrelated to the video.

If a new video is re-recorded on a tape with PCM signals recorded on it using an 8mm VTR that cannot set the PCM recording method,
Data in the latter half of the PCM area is concentrated and destroyed. In contrast, normal errors occur at random locations in the PCM area.

As mentioned above, if an error is detected in the playback data in the latter half of the PCM area, the video area when re-recorded will be
Even if the PCM signal slightly overlaps with the CM area, it can be reliably determined whether the PCM signal recorded in the PCM area is related to the video or is unerased and unrelated to the video.

When re-recording the video signal, if the VTR is of the type that wraps the tape 180 degrees around the drum, the video area when re-recording will slightly overlap with the PCM area, so this first implementation is necessary. For example, it is possible to reliably determine whether the PCM signal recorded in the PCM area is related to the video or is unerased and unrelated to the video.

However, if the 8mm VTR that re-records the video signal is of the type that wraps the tape around the drum (180 degrees ten α), the PCM area will not be destroyed at all. It is not possible to determine whether the PCM signal being displayed is related to the video or is an unerased signal unrelated to the video.

b. Second embodiment FIG. 2 shows a second embodiment of the invention.

In this example, when the video signal is re-recorded, the 8 mm V
TR is the type that wraps the tape 180 degrees,
Even if the video area when re-recording does not overlap with the PCM area, the PC recorded in the PCM area
It is possible to determine whether the M signal is related to the video or is an unerased signal unrelated to the video.

In FIG. 2, a reproduced signal in the PCM area is supplied from an input terminal 11 to a biphase demodulation circuit 12. The output of the biphase demodulation circuit 12 is supplied to the count enable terminal of the counter 13 via the gate circuit 17. The gate circuit 17 is supplied with a signal from a terminal 18 at a timing corresponding to the period of the postamble portion.

A reference clock is supplied to the input terminal 14. This reference clock is supplied to the biphase demodulation circuit 12 and also to the counter 13 via the 1/2 frequency divider circuit 15. The biphase demodulation circuit 12 biphase demodulates the signal from the input terminal 11 based on this reference clock.

When a signal containing consecutive "1"s is output from the reproduction signal of the PCM area, the counter 13 enters the count enable state. With the counter 13, the biphase demodulation circuit 12
While the output of the 1/2 frequency divider circuit 15 is "1", the output of the 1/2 frequency divider circuit 15 is counted.

An output terminal 16 is derived from a predetermined bit of the counter 13. The output from this output terminal 16 is used as a signal for determining whether the signal in the PCM area is recorded in association with the video or is unerased and unrelated to the video.

In this embodiment, it is determined whether the signal in the PCM area is recorded in connection with the video or is unerased and unrelated to the video, depending on whether a predetermined pattern of signals is recorded in the postamble part. It is something.

In other words, if a PCM signal is recorded in the PCM area in association with the video, a predetermined pattern of signals "1 continuous signal" is recorded in the postamble section. If a new video is re-recorded on a tape on which PCM signals have already been recorded using an 8mm VTR that cannot set the PCM recording method, the signals in the postamble section will be destroyed.

A PCM signal is recorded in association with the video in the PCM area, and when a continuous signal of 1 in the postamble section is reproduced, "l" is continuously output from the biphase demodulation circuit 12. Biphase demodulation circuit 1 in the postamble period
When "1" is continuously output from 2 for a predetermined period of time, an output from the output terminal 16 appears.

In this example, the video area and PC when re-recording
Even if the PCM signal does not overlap with the M area, it can be determined whether the PCM signal recorded in the PCM area is related to the video or is unerased and unrelated to the video.

However, in this case, if the erasure signal of the index signal is input into the postamble portion, an erroneous determination will occur.

That is, when an index signal is written into the postamble section, an index erase signal for erasing this index signal at the time of rewriting is recorded in the postamble section. This index signal erasure signal is a continuous signal rl, and has a pattern similar to the pattern of the signal to be recorded in the postamble section.

As in the second embodiment described above, the PCM signal recorded in the PCM area is associated with the video based only on whether a signal with a continuous pattern of "1" in the postamble part is detected. If you try to judge whether it is an object or an unerased item unrelated to the video, if the erase signal of the index signal is input, the PCM signal recorded in the PCM area is always related to the video. It comes to be judged that.

C0 third embodiment FIG. 3 shows a third embodiment of the invention.

In this embodiment/example, there is a PCM second half area error number detection circuit 21 that determines whether the error in the second half of the PCM area is equal to or greater than a predetermined value, and a PCM second half area error number detection circuit 21 that determines whether a predetermined pattern of signals is detected from the postamble portion. An amble detection circuit 22 is provided. In this way, the discrimination accuracy is improved by determining whether the error in the latter half of the PCM area is greater than or equal to a predetermined value and by determining whether a predetermined pattern of signals is detected from the postamble portion. .

In FIG. 3, a reproduction signal of the PCM area is supplied from the input terminal 23.

If a predetermined number of errors are not detected in the reproduction signal of the second half of the PCM area, the output of the PCM second half area error number detection circuit 21 is, for example, "1", and the output of the PCM second half area error number detection circuit 21 is "1", When a predetermined number of errors or more are detected, the output of the PCM second half area error number detection circuit 21 becomes, for example, "O".The output of this PCM second half area error number detection circuit 21 is supplied to the AND gate 24.

The postamble detection circuit 22 determines whether a continuous signal rl is detected from the postamble portion. When a continuous signal of "1" is detected from the postamble part, the output of the postamble detection circuit 22 becomes "1", for example.
”, and if a continuous signal of “1” is not detected from the postamble portion, the output of the postamble detection circuit 22 becomes “0”.

The output of AND gate 24 is taken out from output terminal 25. From the output from the output terminal 25, it is determined whether the signal in the PCM area is recorded in connection with the video or is unerased and unrelated to the video.

If the PCM signal recorded in the PCM area is related to the video, the signal in the second half of the PCM area is not destroyed, so the PCM second half area error number detection circuit 21
The output of becomes rl. Furthermore, if the PCM signal recorded in the PCM area is related to the video, the signal in the postamble portion has not been erased, so the output of the postamble detection circuit 22 becomes rl.

The detection output of the PCM second half area error number detection circuit 21 is r
l, and when the detection output of the postamble detection circuit 22 becomes "1", the output of the AND gate 24 becomes rl.

That is, in this embodiment, only when the number of errors in the latter half of the PCM area is less than a predetermined value and a signal of a predetermined pattern is detected from the postamble part, the AN
The output of the D gate 24 becomes "1", and it is determined that the signal in the PCM area has been recorded in association with the video.

In this way, by detecting whether the number of errors in the latter half of the PCM area is greater than or equal to a predetermined value, and also by detecting whether a signal with a predetermined pattern is detected from the postamble portion, the signal in the PCM area can be This makes it possible to accurately determine whether something was recorded in connection with the image or something left unerased and unrelated to the image.

That is, by doing this, when the video signal is re-recorded, the erasure signal of the index signal is recorded in the postamble part, and the video area and the PCM area at the time of re-recording are not completely overlapped. , P.C.M.
It is possible to correctly determine whether a signal in an area is recorded in connection with a video or is an unerased signal unrelated to a video.

d. Fourth Embodiment FIG. 4 shows a fourth embodiment of the present invention. In FIG. 4, a reproduced signal in the PCM area is supplied from an input terminal 31 to a biphase demodulation circuit 32. A biphase demodulation circuit 32 performs biphase demodulation on the reproduced signal from the input terminal 31.

The output of the biphase demodulation circuit 32 is transmitted to the PCM regeneration circuit 33.
It is also supplied to the postamble detection circuit 37. The postamble detection circuit 37 detects a signal of a pattern corresponding to the postamble signal in the reproduced signal (
This is to detect whether there is a continuous signal of "l". The output of the postamble detection circuit 37 is sent to the gate circuit 3
5.

If there is no error in the reproduced PCM signal, the PCM reproduction circuit 33 outputs an error-free signal CRCox. This error-free signal CRCow is supplied from the PCM reproducing circuit 33 to a retriggerable monostable multivibrator (hereinafter abbreviated as retriggerable monomulti) 34.

The window pulse WP of the gate circuit 35 is formed by the retriggerable monomulti 34. This window pulse W
P is supplied to the gate circuit 35.

The output of gate circuit 35 is taken out from output terminal 36.

If the signal in the PCM area is recorded in conjunction with the video, there will be almost no errors during playback PCM decoding, so as shown in FIG. Continuous output. This error-free signal CRCall allows the retriggerable monomulti 34
continues to be retriggered, and a window pulse WP as shown in FIG. 4B is output. If the signal in the PCM area is recorded in association with video, the window pulse WP is opened until after the delay time τ of the retriggerable monomulti 34 has elapsed after the end of the PCM area.

If the signal in the PCM area is recorded in conjunction with the video, the postamble detection circuit 37 detects a predetermined pattern of signals in the postamble portion after the end of the PCM area, as shown in FIG. 4C. Ru. This signal is output from the output terminal 36 via the gate circuit 35 as shown in the fourth diagram.

The 8mm VTR used to re-record the video signal is of the type that wraps the tape (180 degrees ten α), and the PCM
The signal in the area is unerased and unrelated to the video, and the signal in the latter half of the PCM area is destroyed. Therefore, in this case, the retriggerable monomulti 34
The window pulse WP from is no longer output from the portion corresponding to the latter half area of the PCM area.

Therefore, even if a signal of a predetermined pattern in the postamble portion is detected after the PCM area (in this case, there is a possibility that an erase signal of the index signal is detected), this signal is not output from the output terminal 36.

If the 8mm VTR used to re-record the video signal is of the type that wraps the tape 180 degrees, and the signal in the PCM area is unerased and unrelated to the video, the signal in the PCM area will be destroyed. In this case, the window pulse WP from the retriggerable monomulti 34 is opened until the postamble period after the end of the PCM area. If the signal in the PCM area is an unerased signal that is not related to the video image, no output will appear from the output terminal 36 because the signal of the predetermined pattern in the postamble part will not be detected after the PCM area.

In addition, if the signal in the PCM area is unerased and unrelated to the video, the signal in the latter half of the PCM area is not destroyed, and there is an erased signal of the index signal in the postamble part after the PCM area. , resulting in false detection. However, there is almost no possibility that this will occur, and it does not pose any problem in practice.

【Effect of the invention〕

According to the present invention, it is possible to reliably detect whether the signal in the PCM area is recorded in connection with the video or is unerased and unrelated to the video.

Therefore, even if there is an unerased signal unrelated to the video in the PCM area, this signal can be prevented from being reproduced.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a first embodiment of the invention. FIG. 2 is a block diagram of a second embodiment of the invention. FIG. 3 is a block diagram of a third embodiment of the invention. FIG. 4 shows the fourth example of this invention. FIG. 3 is a block diagram of an embodiment of the invention. FIG. 5 is a timing chart used to explain the fourth embodiment of the present invention, FIG. 6 is a route map used to explain the PCM recording format, and FIGS. 7 and 8 are route maps used to explain the prior art. be. Explanation of major symbols in the drawings 1.11, 23.31! Input terminal. 2.33: PCM regeneration circuit. 21: PCM second half area error number detection circuit. 22.37: Bost amplifier detection circuit. Agent: Patent Attorney Tadashi Sugiura ¥1 award for PCM I-san! To meet the officials of 4 7 no Y Fig. 6 Explanation 1 Fig. 8 A Words eA Live Fig. 8 B Geese 4 Kase Jj Timing ° Total Yard Fig. 7 A vTpt'4 Otsu Ministry A Hi L r--1-7'Figure 7B

Claims (3)

[Claims] (1) PC whose time axis is compressed as an extension of the video track
In a magnetic recording/reproducing device in which an M audio signal is recorded, an error in the signal being played back from a part of the PCM area near the postamble part is detected, and the error is detected from the part of the PCM area near the postamble part. An unerased PCM is detected in the above PCM area due to an error condition in the signal being sent.
A magnetic recording and reproducing device that determines whether there is an audio signal. (2) PC whose time axis is compressed as an extension of the video track
In a magnetic recording and reproducing device in which M audio signals are recorded, the presence or absence of a signal corresponding to the signal recorded in the postamble section is detected, and the presence or absence of the signal corresponding to the signal recorded in the postamble section is used to detect the presence or absence of the signal corresponding to the signal recorded in the postamble section. A magnetic recording and reproducing device is configured to determine whether there is an unerased PCM audio signal in the area. (3) PC compressed in time axis as an extension of video track
In a magnetic recording/reproducing device configured to record an M audio signal, an error in a reproduced signal in a portion near a postamble portion in a PCM area is detected, and a signal corresponding to the signal recorded in the postamble portion is detected. detect the presence or absence of
Depending on the error condition in the signal reproduced from the part near the postamble part in the PCM area and the presence or absence of a signal corresponding to the signal recorded in the postamble part, an unerased PCM audio signal may be left in the PCM area. A magnetic recording and reproducing device that determines whether or not there is a magnetic recording device.