JPH08129792A - Signal reproducing method - Google Patents

Abstract

PURPOSE: To eliminate inversive information of old recording contents and to prevent a malfunction in inversion by performig inversion processing only when recording identification information stored at a reproducing time coincides with the recording identification information detected at present. CONSTITUTION: In an automatically reversed reproducing device, the inversion information for awaiting inversion operation and the recording identification information updated whenever recording is started newly are beforehand redorded in the vicinity of an inversion position on a recording tape 16. When an inversive information detection circuit 71 detects first the inversion information, the recording identification information from a recording identification information detection circuit 72 is stored in a recording identification information buffer 73, and the recording identification information detected successively are compared with the recorded recording identification information by a comparison circuit 74. Then, only when they coincide with each other, an inversion processing circuit 75 performs the inversive processing using the inversive information from the inversion information detection circuit 71.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a signal reproducing method in a small portable digital tape recorder or the like, and particularly records inversion information in the vicinity of an inversion position and performs a process for an inversion operation based on this inversion information. The present invention relates to a signal reproducing method as performed.

[0002]

2. Description of the Related Art In the case of a signal recording / reproducing apparatus, for example, a tape recorder having a so-called auto-reverse function, the first direction is the forward direction or forward (FW).
The reproduction direction is reversed at the end of the tape in the D) direction, and reproduction is performed in the backward direction or the reverse (REV) direction which is the second direction.

As a method of controlling the reversal of the reproducing direction in the automatic reverse reproduction, a method of detecting that the tape is completely wound up and the rotation of the reel is stopped, a method of detecting a so-called leader tape near the tape end, and the like. Is known, and a quick inversion operation is performed in response to these detections. Further, in recent years, when performing reproduction by automatically reversing the traveling direction, in consideration of the fact that the reproduction signal is interrupted for the time required to perform the mechanical reversing operation, the defect-free reversing using the memory is performed. Technology has been developed. As an example of such a technique, the applicant of the present invention has previously disclosed Japanese Patent Publication No. 5-38379 and Japanese Patent Publication No. 5-4.
The technique proposed in Japanese Patent No. 6022 can be cited. The defect-free inversion techniques proposed in these publications will be briefly described. The delay time from the reproduction signal read by the reproduction head to the actual output as an audio signal or the data storage amount in the memory is compared with that before the inversion. The difference is made afterward, and the output of the audio signal or the like during the running reversal operation is continued by the difference in the delay time or the data storage amount. Specifically, the time T _D (= T _DA −T _DB ) of the difference obtained by subtracting the delay time T _DB after reversal from the delay time T _DA before reversal is the traveling reversal required time T
Each delay time T _DA , T _DB , or the amount of data accumulated in the memory is set so as to be _R or more.

[0004]

By the way, in order to effectively perform such defect-free inversion, an inversion process for preparation of the inversion operation or the like must be performed before the inversion operation is actually performed. It is preferable to carry out. In order to perform this reversal process, it is considered to record predetermined reversal information near the reversal position. That is, this reversal information is detected during reproduction, and the reversal processing is performed according to the detected reversal information.

However, in the case where the same tape is overwritten many times and inversion is performed at almost the same location, the inversion information is overwritten many times in the vicinity of the inversion position. At this time, if the old recording content remains unerased due to head clogging during recording, the inversion information of this old recording content is read during playback, and the inversion processing or inversion operation according to this old inversion information is performed. May occur, and in this case, a reversal malfunction may occur, which is not preferable.

In view of the above-mentioned circumstances, the present invention performs the running reversing process and the reversing operation based on only the effective reversal information even when the old recording contents remain in the vicinity of the reversing position without being erased, and the reversing is performed. It is an object of the present invention to provide a signal reproducing method capable of preventing the malfunction of the.

[0007]

According to a signal reproducing method of the present invention, a recording medium is made to travel relative to a recording head portion, and a medium traveling direction is opposite to the first direction from the first direction. In a signal reproducing method for reproducing a signal from the recording medium by reversing in a second direction, recording identification information updated in the recording medium each time recording is newly started, and the first direction. To at least the reversal information for performing the reversal process in the vicinity of the reversal reference position in the second direction, and the record identification information when the reversal information is detected in the vicinity of the reversal reference position. Is stored, and the inversion processing using the inversion information in the reproduction signal is performed only when the stored recording identification information and the recording identification information detected from the current reproduction signal match. Section of To resolve.

Here, a control code as sub data is recorded together with main data on the recording medium, and it is preferable that the recording identification information is written in the control code when the inversion information is recorded. Further, a rotary magnetic head is used as the recording head portion, a magnetic tape having a reciprocal helical scan recording track formed in half in the tape width direction is used as the recording medium, and the signal to be recorded and reproduced is a digital audio signal. That is.

[0009]

When the reversal information is detected in the vicinity of the reversal position of the recording medium during reproduction, the record identification information is stored, and only when the stored record identification information and the currently detected record identification information match. Since the reversal processing using the reversal information at this time is performed, the reversal information of the old recorded content is eliminated, and the malfunction of the reversal caused by using the reversal information of the old recorded content can be prevented.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a schematic configuration of a signal reproducing apparatus to which the signal reproducing method according to the present invention is applied. Although a small portable digital audio tape recorder using a rotary magnetic head is assumed in the present embodiment, the present invention can of course be applied to various other signal reproducing methods and apparatuses, and recording signals can also be recorded. Of course, not only audio signals but also video signals and computer data signals can be used.

In FIG. 1, a tape-shaped recording medium such as a magnetic tape or a recording tape 16 is a capstan 1
7 and the pinch roller 18 are drivingly driven, and the traveling direction is reversely controlled at a predetermined reverse position. The capstan 17 is rotationally driven by a motor 19, and the motor 19 is drive-controlled by a motor drive circuit 19D.

The signal recorded on the recording tape 16 is reproduced by the reproducing head 61 and sent to the reproduction processing circuit or the demodulation circuit 63 via the reproduction amplifier 62, and the reproduction signal from the reproduction processing circuit 63 is transmitted via the memory 64. Is taken out from the terminal 65 and sent to a decoder circuit or the like (not shown). Writing / reading of the memory 64 is controlled by the memory control circuit 67. A control code or CTL component as sub-data is extracted from the reproduction processing circuit 63 by a control code (CTL) extraction circuit 66 and sent to a control unit 70 such as a system controller.

Here, a reciprocating helical scan track is formed on the recording tape 16 by using the upper and lower halves in the tape width direction by the rotary head, and the signal format for one track is shown in FIG. 2, for example. It is as shown. In the signal format shown in FIG. 2, 80 blocks of audio signal data in one track is divided into 40 blocks, and 12 blocks of sub-data are arranged in the central portion. It is called the main data area. An inner double recording area of 9 blocks and an outer double recording area of 7 blocks are provided on both sides of this essential recording area. These double recording areas are blocks of essential recording areas which are separated by 92 blocks. The same contents are recorded at different addresses, and even if the head contact position is displaced due to the rocking of the tape, they are mutually complementary. The sub-data of the 12 blocks in the central part of the track is composed of a control code (CTL) of 8 blocks, an auxiliary code (AUX) of 2 blocks, and an inter-block gap (IBG) of 2 blocks. The control code (CTL) is composed of two 4-block areas, and a part of the control code (CTL) includes inversion information and recording identification information described later.

As a signal format in one block, one block is composed of 288 bits, for example, 11-bit synchronization and 13-bit address, and 1-bit.
With 2 bits as one word, it has 4 words of P and Q parity, 16 words of data such as audio, and 2 words or 24 bits of error detection code (CRC). Of 13 bits of the address, 6 bits are a track address and 7 bits are a block address.

Here, the 2-word or 24-bit error detection code (CRC) is exclusive with the recording identification information using the count value updated every time new recording is performed, or the overwrite protect (OWP) code. Logical OR is taken. That is, in the tape recorder of this embodiment, since the shift of the recording area is allowed, old data may remain unerased near both ends of the track. In addition, there are cases where overwrite erasure cannot be completed due to dropout during recording, clogging of the head, and the like. It is difficult to distinguish the unerased data from the correct data because it is determined by CRC that there is no error. For this reason, the 12-bit overwrite protect (OWP) code is recorded for each block, and the value is updated at each recording break or each recording start. As a result, at the time of reproduction, the OWP code of each block is compared with a preset reference OWP code, and a block that does not match is determined to be the unerased error and eliminated. Specifically, two OWP codes are arranged in the same word to have 24 bits, and an exclusive OR with the 24-bit CRC is recorded.
At the time of error check at the time of reproduction, the exclusive OR with the CRC regenerated from the reproduction data is used to obtain the OWP.
You can restore the code.

Here, in the present embodiment, the reversal information for performing the reversal processing described later is provided near the reversal reference position for reversing the tape running direction, with the control code (CT).
The recording identification information, for example, the OWP code, is also recorded in the control code (CTL) area at least while the inversion information is recorded.

In order to smoothly perform so-called defect-free reversal, the reversal information is recorded from a time point before the reversal reference position for a fixed time, for example, about 80 seconds.
With this defect-free inversion, since the recording signal on the recording tape cannot be read during the inversion operation in the tape running direction, at least the reproduction data for a predetermined time corresponding to this inversion time is stored in the memory before the inversion. During the inversion operation, the reproduction data from this memory is used to output a final reproduction signal such as an acoustic signal to prevent signal loss such as sound interruption, and the reproduction data for the predetermined time is stored. In order to store the data in the memory before the inversion time, increase the tape speed from the fixed time before the inversion to read more data from the recording tape than the data required for the final output such as sound. The difference data of is stored in the memory. In order to perform such a reversal preparation operation, the reversal information is written to a predetermined position of the control code (CTL) from the predetermined time, for example, 80 seconds before.

Specifically, as shown in FIG. 3, the tape 1
The tape speed is increased from the position x _W, which is a predetermined length before the reversal position x _{R of} 6, and only the difference between the data amount read from the tape 16 and the data amount required for the actual audio signal reproduction is stored in the memory. Inverted position x
At the time when _R is reached, the amount of reproduction data that is longer than the time required for reversal is stored in the memory. Therefore, at the time of recording, the accumulation start position or the inversion preparation operation start position x _W is calculated based on the inversion position x _R, and the inversion instruction information or the inversion information such as the inversion flag is written in this position x _W. To do. A specific example of this reversal information is to write a down count value such that the numerical value decreases from the position x _W to the reversal position x _R. In this case, the predetermined value in the reverse position x _R, for example, by previously writing the down count value such that 1 or 0, it is possible to know the distance or time to the reverse position x _R.

FIG. 3 shows some examples of the inversion position x _R and the accumulation start position x _W in such defect-free inversion. That is, A of FIG. 3 shows an example of reversing at the tape end, the tape remaining amount is obtained by measuring the tape running amount at the time of recording, the time from this tape remaining amount to the planned reversal position x _R is calculated, and at the time of reproduction. The above-mentioned accumulation start position or reversal preparation operation start position x necessary for the accumulation operation
Calculate _W. 3B and 3C show an example in which the planned inversion position x _R is calculated in advance according to the recording time of a music source or the like, and the accumulation start position x _W is calculated based on this position x _R. Inversion information, such as a down count value, may be recorded from this position x _W. This is the case, for example, when recording a 50-minute music source on a 60-minute tape.
By recording for 5 minutes, reversing at this 25 minute position and recording for 25 minutes in the reverse or reverse direction, so-called endless reproduction is possible. In this case, the planned reversal position x _R satisfies the condition that the front recording time T ₁ or the forward recording time T _fwd is longer than the back recording time T ₂ or the reverse recording time T _rev. It is preferable to set as follows.

Next, FIG. 4 is a diagram showing an example of the relationship between the reversal position on the recording tape 16 on which the helical scan recording track is recorded and the count value which is the reversal information, and FIG. It is a figure which shows an example of the inversion information and recording identification information written in the control code (CTL) in the signal format of 2. First, in FIG. 4, a recording track on which the tape is driven in the forward direction and recorded, for example, is arranged in the upper half area 16A of the recording tape 16 in the figure, and the tape is recorded in the lower half area 16B of the figure. Recording tracks that are driven and recorded in the reverse direction are arranged. Numerical values in these recording tracks indicate count values as the above-mentioned inversion information. As shown in FIG. 5, this count value is recorded using 12 bits per word in the block of the control code (CTL) of 8 blocks in FIG. In addition, the control code (CTL)
The table inversion invalid flag, the after-inversion flag, and the before-inversion flag, which will be described later, are recorded by using the other 3 bits of one word in the block. Further, the 12-bit value of the OWP code as the above-mentioned recording identification information is recorded using still another word in the block of the control code (CTL). This OWP code is the same as the 12-bit OWP code which is exclusive ORed with the error detection code CRC of FIG. 2 above, but it should be recorded at least only while the inversion information is recorded. Good.
The three words shown in FIG. 5 may be words of consecutive addresses in the block or words of distant addresses.

In the specific example of FIG. 4, a 12-bit count value 0-4095 is used as the inversion information, and the track 4095 tracks before the inversion position x _R is the accumulation start position or the inversion preparation operation start position x. _W, and the count value that is the reversal information is the reversal position x
It becomes 1 at _R , and 4095 at the above-mentioned accumulation start position or inversion preparation operation start position x _W. Further, when the vehicle is traveling forward, the count value which is the reversal information is 4095 at the position x _W.
The count value is sequentially counted down from 1 to 1 at the reversal position x _R , and after the tape is reversed and the tape running direction is set to the reverse direction, the tape is sequentially counted from 1 to 4095 at the position x _W. The count value, which is the reversal information, is set to 0, for example, except in the vicinity of the reversal position.

By the way, at the time of reproduction, the reproduction data storing operation as described above is performed based on the count value which is the inversion information. The inversion information is recorded at the same place. The old record is excluded because the value of the OWP, which is the record identification information, is different, but for some reason, for example, the head is clogged, a portion that is not overwritten due to so-called head clogs, etc. continues for a relatively long time.
When an old record during this time is read at the time of reproduction, the reproduction side circuit reads OWP which is the record identification information of this old recording portion.
You will recognize the code as correct. This is a technique previously proposed by the applicant of the present application in Japanese Patent Laid-Open No. 63-160062, etc., and when a new signal is recorded in an unrecorded portion of a partially recorded tape, or in a recorded tape. This is because, when a new signal is recorded in an unnecessary recording portion, it is necessary to reproduce both the new recording and the old recording, and it is desired that switching between these is performed without delay. . Therefore, even when the record identification information of the second value different from the previously detected record identification information is detected, if the number of detections of the record identification information of the second value exceeds the predetermined number, The record identification information having the second value is treated as new reference identification information, and the record data having the second record identification information is reproduced. Such a function of changing the record identification information, so-called OW
The P change function causes a problem in the vicinity of the reverse position.

That is, when old recording appears for a predetermined time or more near the above-mentioned inversion position, the above-described recording identification information changing function is activated during reproduction, and the inversion information based on this old recording is adopted. , Effective reversal operation is not performed. Therefore, in the present embodiment, when down counting is started by detecting the count value which is the inversion information after the accumulation start position or the inversion preparation operation start position x _W or when the pre-inversion flag is detected, The recording identification information (OWP) in the control code (CTL) is stored in a memory, and the recording identification information (OWP) in the control code (CTL) of the signal read from the tape thereafter is stored in the memory. The recorded record identification information (OWP) is compared with the recorded record identification information, and the inverted information in the signal is used only when they match.

That is, returning to FIG. 1 again, the control code or CTL data extracted from the reproduction processing circuit 63 by the control code (CTL) extraction circuit 66 is at least the inverted information detection circuit in the control unit 70 such as the system controller. 71 and record identification information (OWP) detection circuit 72
Sent to The reversal information detection circuit 71 detects the count value which is the reversal information recorded from the accumulation start position or the reversal preparation operation start position x _W, and controls the detection start pulse to write the record identification information (OWP) buffer 73. The count value itself, which is the inversion information, is sent to the inversion processing circuit 75. The recording identification information (OWP) detection circuit 72 is an OW which is the 12-bit recording identification information written in the control code area.
The P value is detected, and this OWP value is recorded identification information (OWP).
It is sent to the buffer 73 and the comparison circuit 74. In the recording identification information (OWP) buffer 73, the inversion information detection circuit 7
The OWP value, which is the record identification information from the record identification information detection circuit 72 when the detection start pulse from 1 is input, is written, and the written OWP value is sent to the comparison circuit 74. In the comparison circuit 74, the record identification information (OWP)
The current OWP value detected by the detection circuit 72 and the O written in the record identification information (OWP) buffer 73.
The WP value is compared to determine whether or not they are equal, and the comparison result or the determination result is used as the inversion processing circuit 7.
I am sending to 5. According to the comparison result, the inversion processing circuit 75 selects whether to use the inversion information from the inversion information detection circuit 71, and the current OWP value and the recording identification information (OWP) buffer 73 from the current OWP value. Only when the OWP values match, the current inversion information is used to advance the inversion process.

Although FIG. 1 shows an example in which the function of prohibiting the above-described change of the recording identification information in the vicinity of the inversion position is realized by hardware, it can be realized by software, and an example thereof is shown in FIG. Show. FIG. 6 shows a subroutine called each time the inversion information, for example, the down count value is detected near the inversion position. In FIG. 6, when the inversion information is detected, the process proceeds to step S1, and it is determined whether or not the inversion information detection is performed first. If YES in step S1, that is, when the reverse information is detected for the first time, the process proceeds to step S2, and the recording identification information (OW
P) The OWP value which is the record identification information is written in the buffer 73, and the process proceeds to the next step S3. If NO is determined in the step S1, the process directly proceeds to the step S3. In step S3, the currently detected record identification information (OW
P) is equal to the content stored in the buffer 73, and if YES, that is, if they match, the process proceeds to step S4 to perform the inversion process using the inversion information at this time. After that, return, that is, return to the main routine. If NO in step S3, the process returns without performing the inversion process in step S4. Thus, only when the OWP value stored in the buffer 73 and the OWP value in the currently reproduced signal match, the inversion process using the inversion information at that time is performed.

When the OWP values, which are the recording identification information, do not match, the count value from the down counter, which automatically counts down by 1 each time the tape advances one track, may be used as the reversal information. Next, an example of the signal recording device for recording the above-described inversion information and recording identification information on the tape will be described with reference to FIG.

In the device shown in FIG. 7, the input terminal 1
An analog audio signal is supplied to 1. This input audio signal is sent to the A / D converter 12 and converted into a digital signal, sent to the recording head 15 via the encoder 13 and the recording amplifier 14, and is recorded on a tape-shaped recording medium such as a magnetic tape or recorded. It is recorded on the tape 16. The control code (CTL) output circuit 32 sends a control code or CTL data to the encoder 13, and the encoder 13 outputs a recording signal having the signal format as shown in FIG. The recording tape 16 is driven to run by a capstan 17 and a pinch roller 18, and the running direction is reversely controlled at a predetermined reverse position. The capstan 17 is rotationally controlled by a motor 19.

In the control section 31 including a system controller for controlling the operation of each section of the recording apparatus, the count value from the up / down counter 21 is sent to the reversal information output circuit 22 to be reversal information. The inversion information is sent to the control code (CTL) output circuit 32 to be a part of the control code. The control unit 31 also has a record identification information (OWP) output circuit 27 that outputs the OWP value that is the record identification information. This record identification information (OWP)
The output circuit 27 outputs a 12-bit value that is incremented by 1, for example, each time new recording is started, and is sent to the control code (CTL) output circuit 32 and the encoder 13. In the control code (CTL) output circuit 32, at least while recording the inversion information, the recording identification information (OW
P) The control code (CTL) for recording the record identification information from the output circuit 27 at the position as shown in FIG. 5 is output. The encoder 13 always forms and outputs a recording signal for recording a value obtained by exclusive ORing the recording identification information (OWP) and the CRC at the position of the error detection code CRC in FIG. 2 during signal recording.

Up / down counter 2 in control unit 31
For 1, the down-count operation is started in response to an inversion preparation signal described later. This inversion preparation signal is set in advance depending on the time at which the tape end is detected or the music source to be recorded, etc., but is output a fixed time, for example, 80 seconds before the inversion position or the inversion planned position corresponding to the recording time. That is, with this inversion preparation signal, the remaining amount of the recording tape around which the recording tape 16 is wound is calculated by the tape remaining amount detection circuit 23, and the calculated value is, for example, 80 seconds before the tape end which is known in advance. The remaining amount value of 1 is compared with the comparison circuit 24, and when they match, they are output. Further, at the planned reversal position of about half of the preset recording time, for example, a position of about 25 minutes from the tape start end in the case of 50 minutes recording, for example, 80 seconds before, a reversal preparation signal is supplied to the terminal 28. Supplied. These inversion preparation signals can be switched and selected by the changeover switch 25 according to the inversion mode, and the inversion preparation signal selected by the changeover switch 25 is sent to the up / down counter 21 and the inversion processing circuit 20. .

The inversion processing circuit 20 in the control unit 31 starts the inversion processing by the inversion preparation signal from the changeover switch 25, controls the counting direction of the up / down counter 21 up / down, and turns on the inversion flag. Inversion information output circuit 2 for controlling signals for turning on / off
Send to 2. The count value from the up / down counter 21 is also sent to the comparison circuit 26, which outputs an output when the down count value reaches a value corresponding to the inversion position, for example, "1". Inversion processing circuit 2
0, the reversal processing circuit 20 reversely drives and controls the motor drive circuit 19D and the like to reverse the tape accompanying direction. After the tape running direction is reversed, the reversal processing circuit 20 sends an up-count control signal to the up / down counter 21, and the up / down counter 21 is incremented by 1 from a predetermined value such as "1" for each track. Value to be sent to the inversion information output circuit 22.

According to the embodiment of the present invention described above, even when the record identification information is detected for a predetermined time or longer because old recording remains near the reverse position of the tape, the read is performed at the reverse information detection start position. The stored record identification information is stored, and the stored record identification information is compared with the record identification information in the signal currently read, and only when they match, the inversion information detected at that time is used. Therefore, it is possible to prevent a malfunction from occurring in the reversing operation and the reversing preparation operation, and for example, to realize smooth defect-free reversing.

The present invention is not limited to the above-described embodiments. For example, the tape-shaped recording medium may be an optical tape or the like in addition to a magnetic tape, and the recording / reproducing signal may be an audio signal. A video signal or a computer data signal can be used for. A rotary head or a fixed head can be used as the recording head or the reproducing head. Further, the inversion information may include not only the count value but also a flag before inversion, a flag after inversion, and the like. Further, the signal reproducing device and the recording device are not limited to the examples shown in the figure, and it goes without saying that various other configurations can be adopted.

[0033]

As is apparent from the above description, according to the signal reproducing method of the present invention, the signal reproducing method of reversing the medium from the first direction to the opposite second direction to reproduce the signal is performed. In order to perform the reversal process on the recording medium in the vicinity of the reversal reference position from the first direction to the second direction and the record identification information updated each time recording is newly started. At least the reversal information is recorded, and the record identification information when the reversal information is detected in the vicinity of the reversal reference position is stored and detected from the stored record identification information and the current reproduction signal. The reversal processing using the reversal information in the reproduction signal is performed only when the reconciliation information of the old recording content is eliminated, and the reversal processing is performed by using the reversal information of the old recording content. Malfunction of It can be prevented in advance.

Here, a control code as sub-data is recorded on the recording medium as main data together with the main data. By writing the recording identification information in the control code at the time of recording the reversal information, the control code near the reversal position is recorded. The record identification information can be reliably detected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a signal reproducing apparatus to which an embodiment of a signal reproducing method according to the present invention is applied.

FIG. 2 is a diagram showing a signal format of a recording tape used in an embodiment of a signal reproducing method according to the present invention.

FIG. 3 is a diagram showing an example of an inversion position and a data accumulation start position for performing defect-free inversion.

FIG. 4 is a diagram showing an example of a relationship with a count value as inversion information for a recording track on a recording tape.

FIG. 5 is a diagram showing an example of inversion information and record identification information in a control code.

FIG. 6 is a flowchart showing an example of a processing routine when reverse information is detected.

FIG. 7 is a block circuit diagram showing a schematic configuration of an example of a signal recording device for recording a signal on a recording tape used in an embodiment of the signal recording / reproducing method according to the present invention.

[Explanation of reference numerals] 13 encoder 15 recording head 16 recording tape 17 capstan 18 pinch roller 19 motor 19D motor drive circuit 20 inversion processing circuit 21 up / down counter 22 inversion information output circuit 23 tape remaining amount calculation circuit 24, 26 comparison circuit 27 record identification information output circuit 31 control section 32 control code output circuit 61 reproduction head 63 reproduction processing circuit 64 memory 65 control code extraction circuit 67 memory control circuit 70 control section 71 inversion information detection circuit 72 record identification information detection circuit 73 record identification information Buffer 75 Inversion processing circuit

Claims (3)

[Claims] 1. A recording medium, wherein the recording medium is caused to travel relative to a recording head portion, and the medium traveling direction is reversed from a first direction to a second direction opposite to the first direction. In the signal reproducing method for reproducing a signal from the recording medium, recording identification information updated every time recording is newly started, and a vicinity of an inversion reference position from the first direction to the second direction are recorded on the recording medium. At least the reversal information for performing the reversal process is recorded, and the record identification information when the reversal information is detected in the vicinity of the reversal reference position is stored, and the stored record identification information is stored. And a recording identification information detected from the current reproduction signal, the signal reproduction method is characterized in that the inversion processing using the inversion information in the reproduction signal is performed only when the identification information matches. 2. The control code as sub-data is recorded on the recording medium as main data together with the main data, and the recording identification information is written in the control code when the inversion information is recorded. Signal reproduction method described. 3. A rotary magnetic head is used as the recording head unit, and a magnetic tape having reciprocal helical scan recording tracks formed in halves in the tape width direction is used as the recording medium. The signal reproducing method according to claim 1 or 2, wherein the signal reproducing method is a digital audio signal.