JPH07161009A - Magnetic recording / reproducing device - Google Patents

Abstract

(57) [Abstract] [Purpose] When using a magnetic tape for which optimum recording characteristics have been set once for recording, save the trouble of setting optimum recording characteristics again. Before the recording operation, the optimum recording characteristic is set in an optimum recording characteristic setting block 10 by recording / reproducing a test signal output from a test signal generating block. After that, an information signal corresponding to the optimum recording characteristic is recorded together with the main signal during a normal recording operation. When recording again on the magnetic tape on which the information signal is recorded,
The optimum recording characteristics are read from the memory block 12 and the recording characteristics are optimized. [Effect] The optimum recording characteristics can be set by recording an information signal at a position that does not interfere with normal recording / reproduction of the main signal of the magnetic tape and reading it out at the time of recording again.

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 such as a VTR, and more particularly to a magnetic recording / reproducing apparatus for optimizing recording characteristics before recording.

[0002]

2. Description of the Related Art Generally, in a VTR, recording characteristics are constant regardless of the type of magnetic tape.

However, the characteristics of the magnetic tape are not constant depending on the type and grade. Therefore, it is conceivable that at the time of recording / reproducing, the ability of the magnetic tape is not used up, or the reproduced image is broken due to a reversal phenomenon or the like. Even in the same type of VTR, a magnetic head, a recording amplifier,
It is conceivable that the characteristics of the reproduction amplifier and the like may vary to some extent.

As one of the methods for solving such a problem,
Magazine "Audio Video" (published by Denpa Shimbun);
As described in the June 1992 issue, pages 48 to 49, a technique of recording / reproducing a test signal and changing the frequency characteristic at the time of recording based on the result is disclosed.

[0005]

In the above-mentioned prior art, by checking the recording / reproducing characteristics of the VTR for each magnetic tape and changing the recording frequency characteristics, it is possible to obtain good results regardless of the difference in characteristics between the magnetic tapes. It is possible to obtain a reproduced image.

However, the above-mentioned conventional technique does not consider re-recording by using a magnetic tape whose recording / reproducing characteristic is once checked and the frequency characteristic of recording is set so as to obtain a good reproduced image. That is, in order to obtain a good reproduced image, it is necessary to record / reproduce the test signal again and set the recording characteristic again even though the test signal is set once.

An object of the present invention is to solve such a problem and to obtain a good reproduced image regardless of the difference in the characteristics of the magnetic tape, and to record / reproduce a test signal in order to obtain a good reproduced image once. It is an object of the present invention to provide a VTR that sets optimum recording characteristics without performing recording / reproduction of a test signal again when the magnetic tape having the recording characteristics set is used for recording again.

Further, although the above-mentioned conventional technique is configured to optimize the recording characteristics, there is a problem that the setting of the reproducing characteristics at the time of reproducing is not taken into consideration.

A second object of the present invention is to solve such a problem and to provide a VTR which sets an optimum reproduction characteristic according to the reproduction characteristic of a recorded test signal.

[0010]

In order to achieve the above object, the present invention provides means for setting optimum recording characteristics by recording / reproducing a test signal, means for storing the set recording characteristics, and recording thereof. Recording means for recording an information signal for reading the characteristic on the magnetic tape, means for reading the information signal from the magnetic tape, means for reading the recording characteristic from the information signal, and means for setting the read recording characteristic .

In order to achieve the above second object, the present invention comprises means for detecting the C / N of a reproduced test signal,
A means for changing the reproduction frequency characteristic according to the detected C / N is provided.

[0012]

The VTR records / reproduces the test signal before recording the video signal, the audio signal, and the like. The means for setting the optimum recording characteristic sets the optimum recording characteristic from the reproduction state. The recording characteristic storing means stores the set optimum recording characteristic. The stored recording characteristics are numbered, for example, 1 magnetic tape and 2 magnetic tape for each magnetic tape. The recording means for recording the information signal on the magnetic tape uses the assigned number, for example, "1" as the information signal, to perform normal recording / reproduction of these signals together with the video signal, the audio signal, etc. during normal recording. Record in a position that does not interfere. The means for reading the information signal from the magnetic tape reads the information signal recorded on the magnetic tape before the recording operation. The recording characteristic reading unit reads the recording characteristic corresponding to the read information signal (“1”) from the recording characteristic storage unit. The means for setting the read recording characteristic operates so as to set the read recording characteristic. After that, the recording operation is performed with the set optimum recording characteristics.

Further, the means for detecting the C / N of the test signal operates so as to detect the C / N of the reproduced test signal, and the means for changing the frequency characteristic of the reproduction reproduces the detected reproduction signal. When the C / N is good, the frequency characteristic of the reproduction is extended so as to extend, and when the C / N is bad, the frequency characteristic of the reproduction is controlled to be lowered.

[0014]

The present invention will be described below with reference to the illustrated embodiments.

First, a first embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a block diagram of a VTR according to this embodiment.

In FIG. 1, 1 is a magnetic tape, 2 is a rotary magnetic head, 3 is a REC / PB changeover switch, 4 is a reproduction amplifier, 5 is a PB / TEST changeover switch (I
I), 6 is a PB / TEST switch (I), 7 is a reproducing circuit block, 8 is an output terminal, 9 is a recording characteristic judgment block for judging recording / reproducing characteristics from a test signal described later, and 10 is recording characteristic judgment. Based on the recording / reproducing characteristics determined in block 9, an optimum recording characteristic setting block for setting an optimum recording characteristic for obtaining an optimum reproducing characteristic, and 11 is an information signal reading block for reading an information signal described later. Reference numeral 12 is a memory block for storing the recording characteristics set by the optimum recording characteristic setting block 10 in association with the numbers (tape 1, tape 2 ... Or tape A, tape B ...) Assigned to each magnetic tape. The numeral 85 reads the number assigned to each magnetic tape from the information signal read by the information signal reading block 11, and the number,
Alternatively, it is an information signal recording block for outputting the recording characteristic corresponding to the number to the optimum recording characteristic setting block 10. Reference numeral 13 is a timing at which a number assigned to each magnetic tape output from the memory block 12 is recorded at a position where it does not interfere with normal recording / reproduction of a main signal (a video signal, an audio signal, etc. in a VTR). It is a means for recording the number assigned to each magnetic tape together with the main signal, and is a switch for switching the main signal and the number assigned to each magnetic tape according to the timing and supplying them to the REC / PB changeover switch 3. The switch 13 may be an adder as long as it satisfies the condition of "not disturbing normal recording / reproduction". 14 is a test signal generation block for generating a test signal described later, 15 is a recording amplifier, 16 is a recording system circuit block, 17 is REC / TEST switching for switching between normal recording (= main signal recording) and test signal recording A switch, 18 is an input terminal. The position of the switch 13 shown in the above-mentioned configuration is not limited to the above-mentioned place, and it is effective even if it is placed in front of the recording system circuit block 16.

The operation of the VTR in the above structure will be described with reference to FIGS.

FIG. 2 is a flow chart when each block in FIG. 1 operates.

First, the operation of FIG. 1 will be described with reference to the flow indicated by the broken line 20 in FIG.

When the user causes the VTR to perform a recording operation, an external switch (for example, TEST recording switch I) different from a general recording switch is controlled, or the recording switch is controlled in an unusual procedure.

At that time, the VTR, before performing normal recording,
Record the test signal described later for a certain period of time.
This is referred to as test recording), rewound and then reproduced (this operation is hereinafter referred to as test reproduction I). That is, the test signal output from the test signal generation block 14 is the REC / TEST changeover switch 1 which is turned to the test side.
7 through the recording system circuit block 16 to the recording amplifier 15
After being amplified in (1), it is recorded on the magnetic tape 1 by the rotary magnetic head 2 through the switch 13 and the REC / PB changeover switch 3 which is turned to the REC side.

The recorded test signal passes through the rotary magnetic head 2 from the magnetic tape 1 and the REC / PB changeover switch 3 which is tilted to the PB side, is amplified by the reproducing amplifier 4 and is then tilted to the TEST 1 side. It is inputted from the TEST changeover switch (I) 6 to the recording characteristic judgment block 9. In the recording characteristic judgment block 9, the optimum recording characteristic setting block 10 is selected from the reproduction state of the input test signal.
To set the optimum recording characteristics. The recording system circuit block 16 is controlled to the recording characteristic set in the optimum recording characteristic setting block 10, and the optimum recording characteristic is numbered for each magnetic tape and stored in the memory block 12 in association with the numbered number.

At the time of recording the main signal, the information signal (the number assigned to each magnetic tape + the recording VTR unique number indicating the recording VTR) is optimally passed through the switch 13, the REC / PB changeover switch 3 and the rotary magnetic head 2. It is recorded on the magnetic tape 1 together with the main signal that has passed through the recording system circuit block 16 having a recording characteristic and the reproducing amplifier 15.

Next, the operation of FIG. 1 will be described with reference to the flow indicated by the alternate long and short dash line 21 in FIG.

When the user causes the VTR to perform a recording operation, an external switch (for example, TEST recording switch II) different from a general recording switch is controlled, or the recording switch is controlled in a procedure different from usual.

At that time, the VTR, before performing normal recording,
After the magnetic tape 1 is rewound for a certain time (within the range where the information signal can be read), a reproducing operation is performed to confirm the presence of the information signal (this operation is hereinafter referred to as test reproduction II). That is, the signal read from the magnetic tape 1 by the rotary magnetic head 2 is amplified by the reproducing amplifier 4 after passing through the REC / PB changeover switch 3 tilted to the PB side, and then the TES.
PB / TEST selector switch (I
I) Input from 5 to the information signal reading block 11. The information signal reading block 11 checks for the presence or absence of an information signal. When the information signal exists, it is determined from the number unique to the recording VTR in the information signal whether the recorded VTR and the VTR to be reproduced are the same (hereinafter referred to as self-recording / reproduction). When it is determined to be self-recording / reproducing, the number assigned to each magnetic tape in the information signal is read, the recording characteristic corresponding to the number is called from the memory block 12, and the recording system circuit block is output by the optimum recording characteristic setting block 10. 16 is set to the optimum recording characteristic. After that, the numbers assigned to the respective magnetic tapes are passed through the information signal recording block 85, the switch 13, the REC / PB changeover switch 3 and the rotary magnetic head 2, and then the recording system circuit block 16 and the reproducing amplifier 15 having the optimum recording characteristics. It is recorded again on the magnetic tape 1 together with the main signal passed through.

Next, an example of the test signal output from the test signal generation block 14 and the recording characteristic determination by the recording characteristic determination block 9 in the configuration of FIG.
Will be described as an example.

Since the signal input from the input terminal 18 in the configuration of FIG. 1 is a video signal, the signal output from the test signal generation block 14 is similar to the video signal. This test signal is, for example, 0 MHz to 5M
At the time of test reproduction I, the recording characteristics determination block 9 determines the frequency characteristics based on the frequency / amplitude, and the optimum recording characteristics setting block 10 corrects the frequency characteristics by the sweeping at Hz. Control 16

At this time, in FIG. 1 of the present embodiment, the recording characteristic determination is performed by the signal before the reproduction system circuit block 7, but after the FM system signal processing in the reproduction system circuit block 7, the FM is performed. It is also useful to use the signal before the demodulator.

Next, recording of the information signal will be described.

The optimum characteristics set by performing the test recording and the test reproduction I are stored in the memory block 12 with a number unique to the magnetic tape. Then, the number unique to the magnetic tape and the number unique to the recording VTR are recorded at a position (eg, vertical blanking period) that does not prevent normal recording / reproduction of the main signal during normal recording, and the information signal recording block 85 and the switch 13 are provided. To record.

According to this embodiment having such a configuration / operation, after the test recording / test reproduction is performed once and the optimum recording characteristics are set, the optimum recording is performed without taking time when recording on the same magnetic tape. Can be done.

In this embodiment, the information signal is recorded on the magnetic tape, but the present invention is not limited to this.
For example, the same effect can be obtained even in the case of recording in a cassette case containing a magnetic tape, and a series of operations of rewinding at the time of reproduction and test reproduction can be omitted.

Next, a second embodiment of the present invention will be described with reference to FIGS. 3 to 7 and 2. FIG. 3 is an example of a block diagram of the VTR according to this embodiment. From the block diagram of FIG. 1, the input form of the test signal and the control of the recording circuit system are different. In other words, the test signal is the FM of the luminance signal system.
After the modulator, put in the color signal system, control the recording circuit system,
The configuration is such that a luminance signal and a color signal are respectively performed. Here, in FIG. 3, parts corresponding to those in FIG. 1 are denoted by the same reference numerals, and when the same operation is performed, the description thereof will be omitted to avoid duplication. (Note that this is the same hereafter, the same parts as those in the previous drawing are also given the same reference numerals in the subsequent drawings, and the description thereof will be omitted.) The flowchart of FIG. 3 is the same as that of FIG. .

First, the test recording operation will be described.
(The flow indicated by the broken line 20 in the flowchart of FIG. 2) As in the first embodiment, when the user causes the VTR to perform a recording operation, an external switch (for example, a TEST recording switch) different from a general recording switch is used. Control I) or control the recording switch in an unusual procedure.

At that time, the VTR performs test recording before performing normal recording, and performs test reproduction I after rewinding. In other words, the test signal output from the test signal generation block 14 is the luminance signal side REC / TES that has been tilted to the test side.
After passing through the FM recording system circuit block 30 via the T changeover switch 28, it is added to the output of the color signal recording system circuit block 31 in the adder 32, amplified by the recording amplifier 15, and then turned to the switch 13 and REC side. REC
Data is recorded on the magnetic tape 1 by the rotary magnetic head 2 through the / PB switch 3. Similarly, the test signal output from the test signal generation block 14 passes through the color signal side REC / TEST changeover switch 29 turned to the test side, passes through the color signal recording system circuit block 31, and is added to the FM recording system in the adder 32. After being added to the output of the circuit block 30 and amplified by the recording amplifier 15, it is recorded on the magnetic tape 1 by the rotary magnetic head 2 through the switch 13 and the REC / PB changeover switch 3 turned to the REC side.

The recorded test signal passes through the rotary magnetic head 2 from the magnetic tape 1, the REC / PB changeover switch 3 tilted to the PB side, is amplified by the reproduction amplifier 4 and then tilted to the TEST 1 side. It is inputted from the TEST changeover switch (I) 6 to the recording characteristic judgment block 9. In the recording characteristic judgment block 9, the optimum recording characteristic setting block 10 is selected from the reproduction state of the input test signal.
To set the optimum recording characteristics. The FM recording system circuit block 30 and the color signal system circuit block 31 are controlled according to the recording characteristics set in the optimum recording characteristic setting block 10, and the optimum recording characteristics are numbered and attached to the memory block 12 for each magnetic tape. It is stored in correspondence with the number.
At the time of recording the main signal, the number is recorded together with the number unique to the recording VTR together with the main signal at a position in the information signal recording block 85 and the switch 13 that does not prevent normal recording / reproduction of the main signal.

The main signal input from the input terminal 18 is Y
The / C separator 25 distributes the luminance signal and the color signal. The distributed luminance signal is supplied to the pre-emphasis circuit 26.
R, after being FM-modulated in the FM modulator 27,
It passes through the luminance signal side REC / TEST changeover switch 28 turned to the EC side, through the FM recording system circuit block 30, and then the color signal side REC / TEST changeover switch 29,
The color signal that has passed through the color signal system circuit block 31 and the adder 3
Is added at 2. After that, the REC / PB which was added to the above-mentioned number in the switch 13 and pushed down to the REC side
Data is recorded on the magnetic tape 1 by the rotary magnetic head 2 through the changeover switch 3.

Next, the flow indicated by the alternate long and short dash line 21 in the flowchart of FIG. 2 will be described.

When the user causes the VTR to perform a recording operation, an external switch (for example, TEST recording switch II) different from a general recording switch is controlled, or the recording switch is controlled in an unusual procedure.

At that time, the VTR, before performing normal recording,
Perform test playback II and check for the presence of information signals. That is, the signal read from the magnetic tape 1 by the rotary magnetic head 2 is amplified by the reproduction amplifier 4 after passing through the REC / PB changeover switch 3 tilted to the PB side, and then TEST.
PB / TEST selector switch (II) turned over to the 2 side
The data is input to the information signal reading block 11 from 5.
The information signal reading block 11 checks for the presence or absence of an information signal. If there is an information signal, it is determined from the number unique to the recording VTR in the information signal whether the recording / reproduction is performed. When it is determined to be self-recording / reproducing, the number given to each magnetic tape in the information signal is read, the recording characteristic corresponding to the number is called from the memory block 12, and the FM recording system circuit is output by the optimum recording characteristic setting block 10. Block 3
0, the color signal system circuit block 31 is set to the optimum recording characteristic. After that, the number and recording VTR attached to each magnetic tape
The unique number is the information signal recording block 85, switch 1
3, the REC / PB changeover switch 3, the rotary magnetic head 2, and the main signal passed through the recording amplifier 15 and are recorded again on the magnetic tape 1.

Next, control of the FM recording system circuit block 30 and the color signal system circuit block 31 will be described with reference to FIGS.

FIG. 4 is an example of a block diagram showing the FM recording system circuit block 30, the color signal system circuit block 31, and the periphery thereof. Although the test signal is input from the front of the color signal system circuit block 31 in FIG. 3 for convenience of description, it is input after the LPF in the color signal system circuit block 31 in FIG.

First, the operation of test recording will be described.

The test signal output from the test signal generation block 14 is the luminance signal side REC which is tilted to the test side.
/ TEST switch 28 and color signal side REC / T
It is input to the EST changeover switch 29. The signal output from the brightness signal side REC / TEST switch 28 has its frequency characteristics set by the REC equalizer 36 that changes the frequency characteristics by an external control voltage (shown as V1 in the figure), and the recording current of the brightness signal is changed. Volume 3 changed by external control voltage (shown as V2 in the figure)
After 7 times, in the adder 32, REC / T on the color signal side
The EST changeover switch 29 is added to the output of the volume control 41 for changing the recording current of the color signal by an external control voltage (shown as V3 in the figure), amplified by the recording amplifier 15, and then passed through the switch 13 to rotate the magnetic field. Data is recorded on the magnetic tape 1 by the head 2.

After that, the test reproduction I operation is performed to set the optimum recording characteristics (in this embodiment, V1, V2, and V3 are set), and the main signal recording operation is performed. The signal input from the input terminal 18 is amplitude-adjusted by the AGC 35 and then separated into a luminance signal and a color signal in the Y / C separator 25. The luminance signal distributed in the Y / C separator 25 passes through the pre-emphasis circuit 26, is FM-modulated in the FM modulator 27, and then passes through the luminance signal-side REC / TEST changeover switch 28 which is tilted to the REC side to control the luminance signal. RE for changing frequency characteristics by voltage V1
The optimum frequency characteristic is set by the C equalizer 36, and the optimum recording current is input to the adder 32 by the volume 37 that changes the recording current of the luminance signal by the control voltage V2. On the other hand, the chrominance signal is made to have a constant amplitude by the ACC circuit 38, then frequency-converted into a low frequency band by a frequency converter 39, an unnecessary component is removed by a low-pass filter 40 to become a low-frequency band conversion color signal, and it is brought down to the REC side. Color signal side REC
An optimum recording current is input to the adder 32 by the volume 41 that changes the recording current of the color signal by the control voltage V3 via the / TEST switch 28. The FM luminance signal and the low-frequency converted color signal added by the adder are amplified by the recording amplifier 15 and then output to the magnetic tape 1 by the rotary magnetic head 2 together with the output of the information signal recording block 85 input to the switch 13. Will be recorded.

FIG. 5 is an example of a block diagram showing the reproduction system circuit block 7 and its periphery.

First, the operation of the test reproduction I will be described with reference to FIG.

The test signal recorded on the magnetic tape 1 is
After being read by the rotary magnetic head 2 and amplified by the reproduction amplifier 4, it passes through the PB / TEST switch (II) 5 which is tilted to the PB side, and the PB / T which is tilted to the test side.
It is inputted from the EST changeover switch (I) 6 to the switch 54 in the recording characteristic judgment block 9. Switch 54
Accordingly, the frequency characteristic detection block 55, the envelope detection block 56, and the distortion detection block 57 are respectively input, and the frequency characteristics, the envelope, and the distortion are detected by the respective detection blocks. Based on the detection result, the optimum FM frequency characteristic setting block 58, the optimum luminance signal recording current setting block 59, and the optimum color signal recording current setting block 60 in the optimum recording characteristic setting block 10 have a control voltage ( V1, V2, V3) are output.

The operation of the blocks of FIG. 5 during normal reproduction will be described.

The main signal recorded on the magnetic tape 1 is read by the rotary magnetic head 2, amplified by the reproducing amplifier 4, and then turned to the PB side, and the PB / TEST selector switch (II) 5 and the PB / TEST selector switch (II) are also used. PB / TEST pushed down to the side
An FM luminance signal (Y
FM) is an FM equalizer 45, low-frequency conversion color signal (CL)
Is input to the low-pass filter 49. The FM luminance signal having the FM frequency characteristic set by the FM equalizer 45 is balanced in the upper and lower sidebands by the limiter circuit 46, demodulated to the baseband luminance signal by the FM demodulation circuit 47, and S // by the de-emphasis circuit 48. After being improved by N, it is input to the adder 53. Further, the low-pass conversion color signal separated by the low-pass filter 49 is made to have a constant amplitude by the ACC circuit 50, then frequency-converted to a high-frequency by the frequency converter 51, and an unnecessary portion is removed by the band-pass filter 52, and an adder is added. It is added to the luminance signal by 53 and output from the output terminal 8.

FIG. 6 shows the test signal generation block 14-1.
Here is an example.

Reference numeral 65 is for detecting the frequency characteristic.
FM carrier center frequency (4M in VHS mode)
Hz) and upper and lower sidebands (eg, 1.5 MHz, 6.5)
A test signal generation block for detecting an FM frequency characteristic for generating three frequencies of (MHz), 66 for detecting an optimum luminance signal recording current, for example, a test signal generation block for detecting an optimal luminance signal recording current for generating an FM carrier center frequency,
Reference numeral 67 detects the Y-2C component, which is the maximum intermodulation component in the frequency band of the FM luminance signal when the FM luminance signal and the low-frequency conversion color signal are mixed and recorded and reproduced, and sets the optimum color signal recording current. Therefore, the distortion detection test signal generation block generates two frequencies of the FM carrier center frequency and the frequency of the low-frequency conversion color signal (629 kHz in VHS). The test signal from each detection block is selected by the switch 68 and is input to each REC / TEST switch 28, 29 from the output terminal 69. It should be noted that this diagram shows the concept, and if the configuration is such that a signal required for detection can be generated at a required timing, it is not necessary to provide a block for each test signal for detection, and those that can be used commonly That is also effective.

FIG. 7 shows an example of FM frequency characteristic detection and distortion detection for test signal recording and reproduction, respectively. The upper stage is FM frequency characteristic detection and the lower stage is distortion detection. In each graph, the horizontal axis represents frequency and the vertical axis represents level.

First, the FM frequency characteristic detection will be described. As mentioned in the description of FIG. 6, the FM carrier center frequency (4 MHz in the VHS mode) and the upper and lower sidebands at a level smaller by α and β from the FM carrier center frequency level (for example, ± ± than the carrier center frequency).
Two frequencies of 1.5 MHz and 6.5 MHz, which are 2.5 MHz. Of course, the number of frequencies is not limited to two, and may be three or four. ) As the test signal. At the time of reproduction shown on the upper right side, when the levels of the upper and lower sidebands are smaller than the level of the FM carrier center frequency by α ′ and β ′, respectively, α ′,
The recording / reproducing characteristic (FM frequency characteristic) is determined by the absolute value of β ′, | α′−β ′ |, or the like.

Next, the distortion detection will be described. As mentioned in the description of FIG. 6, the center frequency of the FM carrier (V
A signal having a frequency of 4 MHz in the HS mode) and a frequency of the low-frequency conversion color signal (629 kHz in the VHS mode) is recorded as a test signal. At this time, the difference (Y / C mixing ratio) between the level of the signal having the center frequency of the FM carrier and the level of the signal having the frequency of the low-frequency conversion color signal is set by the volume 41 in FIG. At the time of reproduction shown on the lower right side, the Y-2C component (f1: in the present embodiment, which is the maximum intermodulation component in the frequency band of the FM luminance signal when the FM luminance signal and the low-frequency converted color signal are mixed and recorded and reproduced.
The level difference γ between the FM carrier center frequency (Y: 4 MHz in this embodiment) is detected. This γ is set to an optimum value (for example, -23 dB) that maximizes the S / N of the color within the range where the cross beat does not occur.
Set by 1.

In order to set the optimum luminance signal recording current, a signal having a frequency equal to the FM carrier center frequency is test recorded / reproduced. The volume 37 in FIG. 4 is controlled so that the reproduction level at that time is maximized.

According to this embodiment, after the test recording / test reproduction is performed once and the optimum recording characteristics are set, the optimum recording can be performed without taking time when recording on the same magnetic tape.

Also in this embodiment, the information signal is recorded on the magnetic tape, but the present invention is not limited to this.
For example, the same effect can be obtained even in the case of recording in a cassette case containing a magnetic tape.

Next, a third embodiment of the present invention will be described with reference to FIGS.

FIG. 8 is a block diagram of the VTR according to the present embodiment. From the block diagram of FIG.
The value of the optimum recording characteristic (control voltage for controlling the recording system circuit) is removed and the value is directly coded and written on the magnetic tape.

The operations of test recording and test reproduction I are the same as those of the first and second embodiments. The operation of recording the main signal according to the set recording characteristics after the optimum recording characteristics are set through the test recording and test reproduction I will be described.

The main signal input from the input terminal 18 is R
REC / TEST changeover switch 1 which was pushed down to the EC side
7 through the recording system circuit block 16 which has been set to the optimum recording characteristic by the test recording and the test reproduction I, and is amplified by the recording amplifier 15 to be switched to the information signal (the optimum recording characteristic from the optimum recording characteristic setting block 10). After (the control voltage for controlling the recording system circuit) is added to the coded one and the recording VTR's unique number), the REC
After passing through the / PB switch 3 and the rotary magnetic head 2,
It is recorded on the magnetic tape 1.

Next, the operation of FIG. 8 will be described with reference to the flow indicated by the alternate long and short dash line 21 in FIG. The flowchart of this embodiment is based on the "read out optimum recording characteristics from memory" in FIG.
2 is taken, and the block of "Record on magnetic tape" is placed instead of the block of "Record on memory". Although it is partially different from FIG. 2, it does not hinder the explanation.
This will be described with reference to FIG.

When the user controls the VTR to perform a recording operation, by controlling an external switch (for example, TEST recording switch II) different from a general recording switch, or by controlling the recording switch in an unusual procedure, the VTR becomes ,
Before performing normal recording, after rewinding the magnetic tape 1 for a certain time (within the range where the information signal can be read), test reproduction II
I do. That is, from the magnetic tape 1, the rotary magnetic head 2
The signal read out in (1) passes through the REC / PB changeover switch 3 tilted to the PB side, is amplified by the reproduction amplifier 4, and then is pushed to the TEST 2 side by the PB / TEST changeover switch (II) 5 to read the information signal reading block. 11 is input. The information signal reading block 11 checks for the presence or absence of an information signal. If there is an information signal, it is determined from the number unique to the recording VTR in the information signal whether the recording / reproduction is performed. If it is determined to be self-recording / reproducing, the optimum recording characteristic (control voltage for controlling the recording system circuit) in the information signal is
Then, the recording system circuit block 16 is set to the optimum recording characteristic. After that, the coded optimum recording characteristic (control voltage for controlling the recording system circuit) in the information signal has the optimum recording characteristic after passing through the switch 13, the REC / PB changeover switch 3 and the rotary magnetic head 2. The main signal that has passed through the recording system circuit block 16 and the recording amplifier 15 is recorded again on the magnetic tape 1.

According to this embodiment, since the control voltage is directly recorded, it is not necessary to use the main body memory. That is, it is not necessary to consider the memory capacity, and the same effects as those of the first and second embodiments can be obtained for an infinite number of magnetic tapes.

Next, a fourth embodiment will be described with reference to FIG.

In FIG. 9, a C / N detection block 75 is added to the recording characteristic judgment block 9 of FIG. 5, and an optimum reproduction frequency characteristic setting block 76 for setting the optimum reproduction frequency characteristic for the function of the optimum recording characteristic setting block 10. The optimum characteristic setting block 77 to which is added is replaced with the optimum recording characteristic setting block 10 to optimize not only the recording characteristics but also the reproduction characteristics.

The operation of the test reproduction I will be described. The test signal recorded at the time of test recording passes from the magnetic tape 1 through the rotary magnetic head 2 and after being amplified by the reproducing amplifier 4, T
From the PB / TEST selector switch (I) 6 which has been pushed to the EST 1 side, the switch 5 in the recording characteristic determination block 9
4 is input. The signal is input from the switch 54 to the frequency characteristic detection block 55, the envelope detection block 56, the distortion detection block 57, and the C / N detection block 75, respectively. Each characteristic is detected by the frequency characteristic detection block 55, the envelope detection block 56, and the distortion detection block 57, and the optimum FM frequency characteristic setting block 58 and the optimum luminance signal recording current setting block 59 in the optimum characteristic setting block 77 are detected based on the detection results. The optimum color signal recording current setting block 60 controls the control voltage (V
The output of (1, V2, V3) is the same as in the second embodiment.

Here, the newly added C / N detection block 75 detects the C / N in recording / reproduction from the test signal during normal reproduction, and when the C / N value is good, the frequency is detected. The optimum reproduction frequency characteristic setting block 76 in the optimum characteristic setting block 77 outputs a control voltage (V4) for forming the optimum reproduction characteristic so as to extend the characteristic and not to extend when the characteristic is bad. The FM equalizer 45 is set to the optimum frequency characteristic by the control voltage (V4).

In the present embodiment, the detection control is performed in the FM system, but the present invention is not limited to this, and it is effective to perform it in the video system.

Next, a fifth embodiment will be described with reference to FIG.

FIG. 10 shows a flowchart for recording a VTR.

First, the operation 1 which is different from the flow of FIG.
The flow 80 indicated by the dotted line will be described.

When the user causes the VTR to perform a recording operation, an external switch (for example, TEST recording switch II) different from a general recording switch (denoted by REC in the drawing) is controlled.

At that time, the VTR performs a rewinding operation for a certain period (within a range where the information signal can be read), and then performs a reproducing operation to confirm the presence or absence of the information signal, unless it is the first end of the tape. When the information signal exists and self-recording / reproduction is performed, the reproduction state of the information signal is determined.

In determining the reproduction state, for example, the output level of the information signal is checked. When the output level is normal, the optimum recording characteristic is set according to the information signal, and the normal recording operation is performed.
If the output level is lower than the set value, it is possible that the tape or head is deteriorated and the optimum recording characteristics that were set previously may not be met, so test recording and test reproduction (I) should be performed again. Set the optimum recording characteristics. If the output level is lower than a set value, the head may be clogged. Therefore, the function for cleaning the head is activated before performing the above operation, and then the operation for determining the reproduction state of the information signal is performed again. Etc. are also effective.

According to this embodiment, when the optimum recording characteristics are changed by changing the characteristics of the tape, head, etc., it is possible to prevent recording with non-optimal recording characteristics and detect clogging of the head. You can do it.

Next, a sixth embodiment will be described with reference to FIG.

FIG. 11 shows a flow chart at the time of tape loading of the VTR.

When the cassette tape for VTR is inserted into the VTR and the magnetic tape is loaded, the test operation (reading of information signal) is performed at that point.

At that time, when the information signal is not recorded or when the self recording / reproduction is not performed, the standard recording characteristic is set. The subsequent operation (indicated by A in the figure) is the same as in the above-described first to fourth embodiments.

On the other hand, when the information signal is recorded and the recording / reproduction is self-recording, the recording system circuit is set to the optimum recording characteristic based on the information signal. Further, a display portion is provided and displayed to show the user that the information signal is recorded.

The operation indicated by B in the figure will be described. A user controls the VTR so as to perform a normal recording operation, or an external switch (for example, TES) different from a general recording switch which is an operation shown by a chain line in FIG.
When the T recording switch II) is controlled or the recording switch is controlled in a procedure different from the normal one, the recording operation is immediately started according to the optimum recording characteristics set above.

If the user wants to perform test recording and test reproduction again even if the information signal is recorded by the display on the display section, that is, even if the optimum recording characteristic is set, the broken line in FIG. If an external switch (for example, a TEST recording switch I) different from a general recording switch that operates as described above is controlled or the recording switch is controlled in a procedure different from the normal operation, test recording and test reproduction I are performed again.
To determine the optimum recording characteristics.

According to this embodiment, the test reproducing operation can be omitted, so that the time until the optimum recording characteristic is set can be shortened.

In addition to the operation of this embodiment, the information signal read operation is always performed when the rotary magnetic head is in contact with the magnetic tape regardless of the operation of the VTR such as reproduction, still, and search. This is also effective for shortening the time to set the optimum recording characteristics.

[0088]

As described above in detail, according to the present invention, in the magnetic tape whose optimum recording characteristics are once set by the test recording / test reproducing (I), the test recording / test reproducing (I) is performed again at the time of recording again. The recording operation can be performed with the optimum recording characteristic without performing the above.

According to this embodiment, in addition to the above effects,
When reproducing the magnetic tape in which the information signal is written, optimum reproduction characteristics are set.

Further, according to this embodiment, when the optimum recording characteristics are changed by changing the characteristics of the tape, head, etc., recording with non-optimal recording characteristics can be prevented, and head clogging is detected. You can do it.

Further, according to the present embodiment, the test reproducing operation can be omitted, so that the time until the optimum recording characteristic is set can be shortened.

[Brief description of drawings]

FIG. 1 is a block diagram of a VTR according to a first embodiment of the present invention.

FIG. 2 is a flowchart according to first and second embodiments of the present invention.

FIG. 3 is a block diagram of a VTR according to a second exemplary embodiment of the present invention.

FIG. 4 is a recording system block diagram of a VTR according to a second embodiment of the present invention.

FIG. 5 is a playback system block diagram of a VTR according to a second embodiment of the present invention.

6 is a test signal generation block diagram in FIG. 4. FIG.

FIG. 7 is a diagram for explaining the operation in the recording characteristic determination block in FIGS. 3 and 5.

FIG. 8 is a block diagram of a VTR according to a third embodiment of the present invention.

FIG. 9 is a playback system block diagram of a VTR according to a fourth embodiment of the present invention.

FIG. 10 is a flowchart according to a fifth embodiment of the present invention.

FIG. 11 is a flowchart according to a sixth embodiment of the present invention.

[Explanation of symbols]

9 ... Recording characteristic determination block, 10 ... Optimal recording characteristic setting block, 11 ... Information signal reading block, 12 ... Memory block, 14 ... Test signal generating block, 55 ... Frequency characteristic detecting block, 56 ... Envelope detecting block, 57 ... Distortion Detection block, 58 ... Optimal FM frequency characteristic setting block, 59 ... Optimal luminance signal recording current setting block, 60 ... Optimal color signal recording current setting block, 65 ... FM frequency characteristic detection test signal generation block, 66 ... Optimal luminance signal recording Current detection test signal generation block, 67 ... Distortion detection test signal generation block, 75 ... C / N detection block, 76 ... Optimal reproduction frequency characteristic setting block, 85 ... Information signal recording block.

Claims (5)

[Claims] 1. An apparatus for recording a signal on a magnetic tape by a magnetic head, a means for recording a test signal on the magnetic tape, a means for reading the test signal from the magnetic tape, and a reading means for reading the test signal. From the test signal
Means for setting the optimum recording characteristics, means for storing the recording characteristics set by the setting means, and recording for recording an information signal for reading the set recording characteristics from the storage means on a magnetic tape Means, a means for reading the information signal recorded by the recording means from a magnetic tape, a means for reading the recording characteristics stored in the storage means from the information signal read by the reading means, and a reading means. A magnetic recording / reproducing apparatus comprising: means for setting the read recording characteristics. 2. The first recording means according to claim 1, wherein signals having two or more kinds of frequencies are recorded as the test signal, and the test signal recorded by the first recording means is reproduced. From the first determination means for determining the frequency characteristic and the frequency characteristic determined by the first determination means,
First setting means for setting an optimum recording frequency characteristic, and second recording means for recording a signal having a frequency within a frequency band used for normal recording / reproducing as the test signal while changing the recording current. In reproducing the test signal recorded by the second recording means, the second judging means for judging the recording current that maximizes the output amplitude, and the second setting for the recording current judged by the judging means.
Setting means, a luminance signal recorded by the recording current set by the second setting means, and a low-frequency-converted color signal having two kinds of frequencies, and the low-frequency-converted color signal changes the recording current. However, third recording means for recording as the test signal, third determining means for determining the level of the intermodulation component appearing by reproducing the test signal recorded by the third recording means, and the third Third, the optimum recording current for the low-frequency conversion color signal is set based on the level of the intermodulation component determined by the determination unit
And a setting means for the magnetic recording / reproducing apparatus. 3. An apparatus for recording a signal on a magnetic tape by a magnetic head, a means for recording a test signal on the magnetic tape, a means for reading the test signal from the magnetic tape, and a reading means for reading the test signal. From the test signal
Means for setting the optimum recording characteristics, recording means for recording a control signal for controlling the circuit on the recording characteristics set by the setting means on the magnetic tape, and the information signal recorded by the recording means for the magnetic tape A magnetic recording / reproducing apparatus comprising: a means for further reading and means for setting an optimum recording characteristic based on the control signal read by the reading means. 4. The information signal recorded on a magnetic tape during reproduction according to claim 2 or 3,
It is characterized in that a detection means for detecting the C / N of the information signal and a setting means for setting an optimum reproduction frequency characteristic from the C / N of the information signal detected by the detection means are provided. Magnetic recording / reproducing device. 5. The means according to claim 2, wherein the information signal is read from a magnetic tape, a detecting means for detecting the level of the information signal read by the reading means, and a level detected by the detecting means. A determining means for determining a change in the characteristics of the magnetic tape or the magnetic head,
A magnetic recording / reproducing apparatus provided with.