JPH0896306A - Magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE: To record a desirable signal under the optimum condition by variably controlling a recording level range to be set by a setting means based on a detecting result of a using time detecting means. CONSTITUTION: The device is equipped with a switch 1 as the setting means for setting the recording level of a recording signal in a prescribed range, a recording amplifier 2 for recording the recording signal on a recording track based on the recording level set by the switch 1 and a regenerative FM detector 9 as a detecting means for detecting the recording signal as a reproduced FM signal. Moreover, the device is equipped with a using time detecting means 12 for detecting the using time of a rotary magnetic head and a microcomputer 10 as a control means for variably controlling the recording level range to be set by the setting means based on a detecting result of this detecting means 12 and also for setting a recording level when a detecting result of the detecting means becomes a max. value, to be at an optimum recording level. Since the optimum recording level can be set from a small number of recording level detecting points, a desired signal can be recorded under the optimum condition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic recording / reproducing apparatus which always sets an optimum signal recording level.

[0002]

2. Description of the Related Art FIG. 4 is a diagram for explaining a conventional magnetic recording / reproducing apparatus, and FIG. 5 is a diagram for explaining a conventional method for setting an optimum recording level.

In a conventional magnetic recording / reproducing apparatus, as shown in FIG. 4, first, a changeover switch 1 for supplying a normal input signal (video / audio signal supplied to the magnetic recording / reproducing apparatus) and a recording signal at the time of recording, Recording amplifier 2 that amplifies the signal output from the changeover switch 1 to a predetermined level, changeover switch 3 that supplies the signal output from the recording amplifier 2 to the head changeover switch 7, and changeover switch 3
A head changeover switch 7 for supplying the signal output from the magnetic heads to the magnetic heads (rotary magnetic heads) 4a and 4b mounted on the rotary head 5, and a recording track formed on the magnetic tape 6 with the signal supplied from the head changeover switch 7. Magnetic heads 4a, 4b for recording on,
The reproduction signal reproduced by the preamplifier 8 is supplied through the changeover switch 3, and the reproduction FM detector 9 for converting the reproduction signal (reproduction FM signal) amplified by the preamplifier 8 to a predetermined level into a DC signal. And a microcomputer 10 for comparing the reproduction level of the DC signal output from the device 9 with a predetermined level.

When an input instruction from a user (not shown) is supplied to the microcomputer 10, the microcomputer 10 supplies a switch control signal (A) to the changeover switch 1 and changes the output of the changeover switch 1 to the a side. A DC signal output supplied from a detection signal generator (not shown) is supplied to the a side in a FM-modulated form.

The signal output from the changeover switch 1 is supplied to the recording amplifier 2 and is amplified to a predetermined recording level in the recording amplifier 2. The recording amplifier 2 uses the microcomputer 10 similarly to the switch control signal (A) described above.
The recording level of the signal is changed by the gain control signal (B) output from the.

The recording amplifier 2 gradually changes the recording level preset by the gain control signal (B) (here, the levels A to E), and uses the amplified signal as the recording signal on the R side of the changeover switch 3. Supply to.
The microcomputer 10 uses the switch control signal (A) described above.
Similarly, by supplying the switch control signal (C) output to the changeover switch 3, the recording signal is supplied to the head changeover switch 7.

The head changeover switch 7 supplies the supplied recording signal to the magnetic heads 4a and 4b mounted on the rotary drum 5, and the magnetic heads 4a and 4b record the recording signal on a recording track on the magnetic tape 6. . When this recording signal is recorded on the magnetic tape 6 for a predetermined period, the running system of the magnetic tape 6 (not shown) is controlled by the microcomputer 10 to rewind the magnetic tape 6 by the amount corresponding to the recording of the recording signal.
This recorded signal is reproduced.

The magnetic heads 4a and 4b obtain a reproduction signal by scanning the recording track on which the recording signal is recorded, and supply this to the P side of the changeover switch 3 via the head changeover switch 7. The changeover switch 3 supplies the reproduction signal supplied to the P side to the preamplifier 8 by the switch control signal (C) output from the microcomputer 10 simultaneously with the control of the running system of the magnetic tape 6.

The reproduction signal amplified by the preamplifier 8 to a predetermined level is reproduced by the reproduction FM detector 9 as a reproduction DC signal (see FIG. 5).
(A) Reproduced FM detection output (shown)
Supplied to 10. The reproduced DC signal supplied to the microcomputer 10 has the above-mentioned recording levels A to E as shown in FIG.
, The microcomputer 10 detects the recording level (recording level D at this time) when the maximum value of the reproduced DC signal is obtained.

Then, the microcomputer 10 uses this recording level D
Gain control signal (B)
Is supplied to the recording amplifier 2 and the recording level of the recording amplifier 2 is set.

By the way, in a magnetic recording / reproducing apparatus using a rotating magnetic head, a magnetic tape is wound around a rotating drum rotating at a high speed to run the magnetic tape. Causes head wear. Therefore, even if a recording signal of the same recording level is supplied to a magnetic head that has been used for some time, the recording current level actually recorded on the magnetic tape changes depending on the degree of wear of this magnetic head.

When the recording current curve of the magnetic head used up to a certain time is represented as shown in FIG. 5 (a), when the magnetic head is used for a longer time, the recording current is affected by the wear of the magnetic head. The curve changes as shown in FIG. That is, the above-mentioned optimum recording level was the recording level D (shown in FIG. 5A) until a certain time.
The use of this magnetic head for a longer time causes the influence of abrasion, and the optimum recording level changes to the recording level B (shown in FIG. 5B).

Further, even if the same magnetic head material is used, there is a difference in solids, so that the predetermined recording level is not always the optimum recording level.

Therefore, in consideration of the influence of the wear of the magnetic head or the difference in characteristics (solid difference), an image quality recording / reproducing apparatus capable of always recording a high quality image even when the suitable recording current fluctuates (JP-A-6-76212). No. gazette) was proposed.

[0015]

However, in the above-mentioned magnetic recording / reproducing apparatus, since the fluctuation of the optimum recording level due to the wear of the magnetic head is largely predicted and the variation in the performance of the magnetic tape is taken into consideration, at least the above-mentioned is required. Since it is necessary to detect the reproduced FM signals at the recording levels A to E, there is a disadvantage that the operation of setting the optimum recording level takes time.

Further, since the above-mentioned recording levels A to E are preset recording levels, when a signal is actually recorded on the magnetic tape at this recording level, it exceeds the optimum recording level of the magnetic tape. In this case, the recording level may be saturated and the recorded signal may be distorted and reproduced. Therefore, it is necessary to provide a limiter unit for setting the recording level.

Further, the above-mentioned image quality recording / reproducing apparatus has the following problems. That is, in order to record an image for a long time, a method of recording only one of several frames to several hundreds of frames by intermittently feeding a tape is adopted, and a video signal (also called a video signal) is recorded at regular intervals. The signal for recording current adjustment is recorded / reproduced during the recording pause period of intermittent recording to optimally adjust the recording current. Therefore, if the next video signal is recorded as it is, the video signal for one frame becomes discontinuous. .
In order to prevent this, the magnetic tape is rewound for one frame and continuous video signals are recorded, so that the control of rewinding the magnetic tape is complicated.

Further, since the recording / reproducing of the signal for adjusting the recording current is performed during the recording pause period of the above-described intermittent recording every fixed time, there is an inconvenience that there is much waste. That is, since the recording / reproducing time is detected by the reproducing time detecting circuit (28) at regular time intervals and the recording current setting changeover switch (24) is set in accordance therewith, the predetermined recording current adjustment is performed. Since the recording / reproducing of the signal for use is performed each time, there is a disadvantage that the operation of optimally adjusting the recording current is wasteful.

Therefore, it is desired to eliminate the above-mentioned inconvenience and to provide a magnetic recording / reproducing apparatus that always adjusts the recording current optimally according to the usage state of the magnetic head, not only when the video signal is recorded for a long time. It was

[0020]

Therefore, the present invention provides the following configurations (1) to (3) in order to solve the above-mentioned problems. (1) A reproduction signal obtained by recording a recording signal on a recording track formed on the magnetic recording medium 6 by the rotary magnetic heads 4a and 4b in a stopped state of the magnetic recording medium 6 and reproducing the recording signal. A magnetic recording / reproducing apparatus for setting an optimum recording level at which the level of
Setting means 10 for setting the recording level of the recording signal in a predetermined range, and recording means 1, 2, 3 for recording the recording signal on the recording track based on the recording level set by the setting means 10, Detecting means 3, 8, 9 for detecting the recording signal as a reproduced FM signal, and the rotary magnetic head
4a, 4b use time detection means 12 for detecting the use time, the control means variably control the range of the recording level set by the setting means 10 based on the detection result of the use time detection means 12, the detection means 3, Control means 10 for setting the recording level when the detection results of 8 and 9 reach the maximum value to the optimum recording level
And a magnetic recording / reproducing apparatus. (2) A reproduction signal obtained by recording a recording signal on a recording track formed on the magnetic recording medium 6 by the rotary magnetic heads 4a and 4b and reproducing the recording signal while the magnetic recording medium 6 is stopped. A magnetic recording / reproducing apparatus for setting an optimum recording level at which the level of
Setting means 10 for setting the recording level of the recording signal in a predetermined range, and recording means 1, 2, 3 for recording the recording signal on the recording track based on the recording level set by the setting means 10, Based on the detection means 3, 8, 9 for detecting the recording signal as a reproduction FM signal, the usage time detection means 12 for detecting the usage time of the rotary magnetic head, and the detection result of the usage time detection means 12. Recording when the range of the recording level set by the setting means 10 is variably controlled immediately before the desired signal is recorded on the magnetic recording medium 6 and the detection result of the detecting means 3, 8, 9 takes the maximum value. A magnetic recording / reproducing apparatus comprising: a control means (10) for setting the level to an optimum recording level. (3) The magnetic recording / reproducing apparatus according to the above (1) or (2), further comprising a storage means 11 for storing the optimum recording level set by the control means 10.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a block diagram for explaining an embodiment of the magnetic recording / reproducing apparatus, FIG. 2 is a view for explaining setting means which is a main part of the magnetic recording / reproducing apparatus, and FIG. 3 is a book. It is a figure for explaining a setting means which is an important section of a magnetic recording and reproducing device. A magnetic recording / reproducing apparatus according to the present invention will be described below with reference to the drawings. The same components as those described above are designated by the same reference numerals, and the description thereof will be omitted.

As shown in FIG. 1, the magnetic recording / reproducing apparatus according to the present invention includes a changeover switch 1 for supplying a normal input signal (video / audio signal supplied to the magnetic recording / reproducing apparatus) and a recording signal at the time of recording. A recording amplifier 2 for amplifying the signal output from the changeover switch 1 to a predetermined level,
A changeover switch 3 for supplying the signal output from the recording amplifier 2 to the head changeover switch 7, a head changeover switch 7 for supplying the signal output from the changeover switch 3 to the magnetic heads 4a, 4b mounted on the rotary head 5,
A magnetic head for recording the signal supplied from the head changeover switch 7 on a recording track formed on the magnetic tape 6.
4a, 4b, a reproduction signal reproduced by the magnetic heads 4a, 4b at the time of reproduction is supplied through the changeover switch 3, and a reproduction signal (reproduction FM signal) amplified to a predetermined level by the preamplifier 8 is a direct current signal. Play F to convert to
M detector 9, reproduction microcomputer A microcomputer 10 for comparing the reproduction level of the DC signal output from the FM detector 9 with a predetermined level, and a magnetic head 4 for recording / reproducing operation.
It is composed of a usage time detection circuit 12 for detecting the usage time of the magnetic heads 4a, 4b by supplying a current to a, 4b.

When an instruction (recording instruction) for recording a desired signal (video / audio signal) is supplied from the user to the microcomputer 10 by input means (not shown), the magnetic recording / reproducing apparatus is switched to the recording mode, and the microcomputer 10 is switched to the recording mode. Supplies the switch control signal (A) to the changeover switch 1,
The output of the changeover switch 1 is changed over to the a side. A DC signal output supplied from a detection signal generator (not shown) is supplied to the a side in a FM-modulated form.

At this time, the microcomputer 10 also performs servo control of a capstan (not shown) that drives the running system of the magnetic tape 6, and holds the running of the magnetic tape 6 in a stopped state. At the same time, the servo control of the rotary drum 5 is performed and this is rotationally driven.

The signal output from the changeover switch 1 is supplied to the recording amplifier 2 and set to a predetermined recording level in the recording amplifier 2. The recording amplifier 2 uses the microcomputer 10 similarly to the switch control signal (A) described above.
The recording level of the signal is changed by the gain control signal (B) output from the.

The recording amplifier 2 changes the recording level stepwise by the gain control signal (B) (levels B to B).
Then, the amplified signal is supplied to the R side of the changeover switch 3 as a recording signal. Microcomputer
Reference numeral 10 supplies a switch control signal (C), which is output in the same manner as the above-mentioned switch control signal (A), to the changeover switch 3, thereby supplying the above recording signal to the head changeover switch 7.

Here, in the microcomputer 10, for example, empirically accumulated information on the recording current characteristic of the magnetic head is stored in advance according to the usage time (shown in FIG. 2A).
Then, the microcomputer 10 sets a high recording level (three levels of the recording levels B to D described above) according to the recording current characteristic, for example.

The head changeover switch 7 supplies the supplied recording signal to each rotary magnetic head (magnetic head mounted on the rotary drum 5) 4a, 4b in synchronization with a drum pulse described later, and these magnetic heads 4a are supplied. , 4b is magnetic tape 6
This recording signal is recorded on the upper recording track.

At this time, since the running of the magnetic tape 6 is stopped, the above recording signal is recorded on one recording track. Therefore, for example, the rotary drum is rotated in synchronism with the drum pulse generated from the synchronizing signal inserted in the above-mentioned input signal (in this case, the video signal) to erase the signal on the recording track. Record and play back. Here, the signal erasure on this recording track is
For example, it is a signal obtained by FM-modulating a DC signal output from the above-mentioned detection signal generator to a sufficiently high frequency. When such a signal is recorded on a recording track on the magnetic tape 6, this signal is Even if the signal is reproduced by the magnetic head, the signal is not reproduced in the frequency band of the video signal or audio signal to be modulated and recorded, and it is as if the signal on the recording track is erased. After the erasing, at least one of the magnetic heads records the above-mentioned recording signal, and the same magnetic head (at least a magnetic head having the same azimuth angle) reproduces the recorded signal.

At this time, for example, by supplying the above-mentioned drum pulse to the microcomputer 10,
When the voltage value of the DC signal output from the detection signal generator and the output of the changeover switch 3 are switched to the R side at a timing synchronized with the drum pulse, the above signal erasing and recording of the recording signal can be performed. .

Then, for example, immediately after the above recording signal is recorded, the microcomputer 10 switches the output of the changeover switch 3 to the P side at the timing synchronized with this drum pulse. When the same magnetic head scans the recording track again, a reproduction signal is obtained and supplied to the preamplifier 8.

The reproduction signal amplified to a predetermined level by the preamplifier 8 is reproduced by the reproduction FM detector 9 as a reproduction DC signal (see FIG. 2).
It is converted into a reproduction FM detection output shown in (a) and supplied to the microcomputer 10. At this time, the microcomputer 10 detects the recording level when the maximum value is obtained in the reproduction DC signal by comparing the detected reproduction DC signal with the above-mentioned recording current characteristic of the magnetic head.

Here, the recording current characteristic obtained by using the magnetic head made of the same material is previously stored in the microcomputer 10 in correspondence with the wear stage of the magnetic head according to the operating time. For example, the boundary at which the recording current characteristic changes due to wear of the magnetic head is set to a predetermined time T ₁ , and the recording level is set according to the predetermined recording current characteristic until the operating time of the magnetic head reaches this time T _1. However, when the usage time of the magnetic head exceeds this time T ₁ , it is judged that the wear of the magnetic head has progressed and the recording current characteristic has changed, and the recording level can be set according to the changed recording current characteristic. .

The operating time of the magnetic head may be measured, for example, from the time when the power source of the magnetic recording / reproducing apparatus is turned on to the time when it is turned off. Further, for example, in a state where the magnetic tape 6 is wound around the rotary drum 5, the time from the start of rotation of the rotary drum 5 to the stop of rotation may be counted from the drum pickup pulse.
Here, the drum pickup pulse is a pulse signal output in synchronization with the rotation of the rotary drum 5 used for controlling the rotation of the rotary drum 5.

The reproduced DC signal supplied to the microcomputer 10 is
As shown in FIG. 2A, since the values are obtained corresponding to the recording levels B to D, the microcomputer 10 compares the recording current characteristic of the magnetic head with the reproduction DC signal,
The recording level (recording level D at this time) corresponding to the reproduction DC signal having the maximum value is detected.

The microcomputer 10 supplies the above-mentioned gain control signal (B) to the recording amplifier 2 and switches the switch control signal (A) so that the gain of the recording amplifier 2 is set to the detected recording level D. Then, the changeover switch 1 outputs a normal input signal (video / audio signal supplied to the magnetic recording / reproducing apparatus).

Then, this normal input signal is subjected to a well-known signal recording process (not shown), set to the above-mentioned optimum recording level D by the recording amplifier 2, and the changeover switch 3,
Data is recorded on the magnetic tape 6 by being supplied to the magnetic heads 4a and 4b via the head changeover switch 7.

Thus, the desired signal can be recorded at the optimum recording level and the recorded signal can be reproduced.

[0039] Now, for example, repeats the recording operation by the magnetic recording and reproducing apparatus, a case where the magnetic head 4a, the operating time of the 4b exceeds a predetermined time T ₁ described above.
At this time, if the user's recording instruction is input,
The above-mentioned usage time detection circuit 12 supplies the microcomputer 10 with detection information indicating that the usage time of the magnetic heads 4a, 4b has exceeded the predetermined time T ₁ . As a result, the microcomputer 10 causes the magnetic head 4a,
It is determined that the current of the recording currents of the magnetic heads 4a and 4b has changed due to wear of 4b, for example, as shown in FIG. 2B.

The microcomputer 10 uses this recording current characteristic (see FIG.
The above-described gain control signal (B) is supplied to the recording amplifier 2 so as to set a recording level (levels A to C) that is a high recording level according to (b)). Then, the switch control signal (A) for controlling the changeover switch 1 so as to output the detection signal from the detection signal generator is output.

In the same manner as described above, the microcomputer erases the recording track on the magnetic tape 6 and records and reproduces the recording signal when the magnetic tape 6 is in the stopped state.
10 obtains a reproduced DC signal as shown in FIG. Therefore, the microcomputer 10 compares these reproduction DC signals, detects the recording level (recording level B in this case) when the reproduction DC signal showing the maximum output level is obtained, and records by the gain switch control signal (B). The recording level of the amplifier 2 is set to this recording level B.

Thus, the optimum recording level is set in the recording amplifier 2 according to the wear of the magnetic heads 4a, 4b due to the use time of the magnetic heads 4a, 4b exceeding the predetermined time T ₁ . Then, by supplying a normal input signal to the recording amplifier 2 by the above-mentioned switch control signal (A), the input signal is recorded on the magnetic tape 6 at an optimum recording level according to the wear of the magnetic heads 4a, 4b. can do.

[0043] The optimum recording level detection by the recording current characteristics of the magnetic head described above, for example, as shown in FIG. 3, until a predetermined time T ₁ of the above-described recording current characteristics of the magnetic head is the maximum value in the "range a" If the predetermined time T ₁ is exceeded, the recording current characteristic of the magnetic head has the maximum value in the “range b”, and if the usage time of the magnetic head is longer, it has the maximum value in the “range c”. Of course, the level may be detected. That is, the above-mentioned recording levels do not have to be limited to the three recording levels as described above, and it is sufficient that the maximum reproduction DC signal can be obtained from the recording current characteristics of the magnetic heads 4a and 4b.

Further, since the above-mentioned optimum recording level is obtained from the level according to the recording current characteristic of the magnetic head, as described above, the recording level set by erroneously saturates the recording level. It is possible to prevent the signal from being distorted and reproduced. That is, the above-mentioned limiter means is not required, and the optimum recording level can always be obtained.

In addition, the microcomputer 10 can be prepared in advance for the variation of the optimum recording level due to the individual difference of the magnetic head.
By obtaining the reproduction DC signal of this magnetic head from the recording current characteristics of the magnetic head of the same material stored in the table, and obtaining the optimum recording level, the almost ideal optimum recording level that absorbs this individual difference is obtained. You can

Further, since the recording signal is actually recorded on the magnetic tape 6 and the optimum recording level is obtained from the reproduced DC signal obtained by reproducing the recording signal, the optimum recording level in consideration of the performance of the magnetic tape 6 is also obtained. be able to.

The above-mentioned recording level detection may be performed from any of the recording levels A to E, and it is needless to say that the order is not limited.

The optimum recording level obtained as described above changes according to the usage time of the magnetic head, but it does not change greatly in 1 hour or 2 hours, and therefore, Of course, the same recording level may be used for some time after the optimum recording level is set. That is, for example, the microcomputer 10
The value of the recording level detected as described above is stored in the memory 11. Of course, the recording level value stored in the memory 11 may be continuously used until a certain time (for example, the time T ₁ described above) detected by the usage time detection circuit 12. .

[0049]

As described above, according to the configuration of the present invention as set forth in claim 1, the range of the recording level set by the setting means can be varied based on the detection result of the usage time detection means with a simple configuration. By controlling it, it is possible to set the optimum recording level from a small number of recording level detection points, so even if the head wear progresses according to the operating time of the magnetic head and the recording current characteristics change, the optimum recording level There is an effect that the recording level can be obtained. That is,
There is an effect that a desired signal can be recorded in an optimum state according to the recording current characteristic of the magnetic head.

Further, by obtaining the optimum recording level from the level in accordance with the recording current characteristic of the magnetic head, it is possible to prevent the reproduced signal from being distorted and reproduced due to saturation of the recording level. There is an effect that the limiter means can be omitted.

As described above, according to the second aspect of the present invention, in addition to the effects described above, it is possible to set the optimum recording level described above each time a desired recording operation is performed. There is an effect that a desired signal can always be recorded in an optimum state according to the recording current characteristic of the magnetic head.

As described above, according to the configuration of the present invention as set forth in claim 3, in addition to the above-mentioned effect, the optimum recording level according to the recording current characteristic of the magnetic head is stored in the memory, and thus the magnetic head is stored. Since it is possible to store and use the optimum recording level obtained at each stage in which the wear of the head progresses according to the usage time, there is an effect that the optimum recording level can be detected by a simple operation.

[Brief description of drawings]

FIG. 1 is a block diagram for explaining an embodiment of the present magnetic recording / reproducing apparatus.

FIG. 2 is a diagram for explaining setting means which is a main part of the magnetic recording / reproducing apparatus.

FIG. 3 is a diagram for explaining setting means that is a main part of the magnetic recording / reproducing apparatus.

FIG. 4 is a diagram for explaining a conventional magnetic recording / reproducing device.

FIG. 5 is a diagram for explaining a conventional method for setting an optimum recording level.

[Explanation of symbols]

 1 Changeover Switch (Recording Means) 2 Recording Amplifier (Recording Means) 3 Changeover Switch (Recording Means / Detecting Means) 4a, 4b Magnetic Head 6 Magnetic Recording Medium 8 Preamplifier (Detecting Means) 9 Reproducing FM Detector (Detecting Means) 10 Control Means 11 Memory (Storage Means) 12 Usage Time Detection Means

Claims (3)

[Claims] 1. A level of a reproduction signal obtained by recording a recording signal on a recording track formed on the magnetic recording medium by a rotating magnetic head in a stopped state of the magnetic recording medium and reproducing the same. A magnetic recording / reproducing apparatus for setting the maximum optimum recording level, comprising: setting means for setting the recording level of the recording signal within a predetermined range; and the recording signal based on the recording level set by the setting means. Recording means for recording on the recording track, detection means for detecting the recording signal as a reproduction FM signal, usage time detection means for detecting usage time of the rotary magnetic head, and detection result of the usage time detection means And variably control the range of the recording level set by the setting means,
A magnetic recording / reproducing apparatus comprising: a control unit that sets a recording level when the detection result of the detection unit takes a maximum value to an optimum recording level. 2. A level of a reproduction signal obtained by recording a recording signal on a recording track formed on the magnetic recording medium by a rotary magnetic head and reproducing the recorded signal when the magnetic recording medium is in a stopped state. A magnetic recording / reproducing apparatus for setting the maximum optimum recording level, comprising: setting means for setting the recording level of the recording signal within a predetermined range; and the recording signal based on the recording level set by the setting means. Recording means for recording on the recording track, detection means for detecting the recording signal as a reproduction FM signal, usage time detection means for detecting usage time of the rotary magnetic head, and detection result of the usage time detection means And variably controlling the range of the recording level set by the setting means immediately before recording a desired signal on the magnetic recording medium, Magnetic recording and reproducing apparatus, characterized in that the detection result of the serial detection means and control means for setting the optimum recording level recording level when taking the maximum value. 3. A storage means for storing the optimum recording level set by the control means.
3. The magnetic recording / reproducing apparatus according to any one of items 1 to 3.