JP2001155301A - Detecting method of degradation of magnetic recording tape and degradation detector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the degradation detecting method of a magnetic recording tape and the degradation detector, which are capable of accurately detecting the degradation of the magnetic recording tape while making it correspond to the recording position and also capable of surely and easily judging the degrading condition of the magnetic recording tape. SOLUTION: After the high frequency component is removed from an information signal of a recording source by a low-pass filter 2 at the time of recording to the magnetic recording tape, a high frequency signal from a high frequency signal generator 3, which is formed to a reference signal for judging the tape deterioration, is always superimposed in a superimposing circuit 4 and recorded by a voice head 6, then the detector is constituted so as to judge the deterioration by detecting the degradation of the magnetic recording tape with a system controller 10 by using the high frequency signal separated from the reproduced signal by a high-pass filter 8 as the reference signal for judging the tape deterioration, at the time of reproduction from the magnetic recording tape with the voice head 6, and by this constitution, the degradation of the magnetic recording tape is detected in the manner of comparing the reproduction level of the high frequency signal actually recorded on the magnetic recording tape with the signal level at the time of recording this high frequency signal.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for detecting the degree of deterioration of a magnetic recording tape for detecting the degree of deterioration of a magnetic recording tape in order to determine the degree of deterioration.

[0002]

2. Description of the Related Art In recent years, magnetic recording / reproducing devices of various specifications corresponding to various recording media have been used by general users for recording and reproducing information signals such as sound and images. , Can record for a long time,
Conventionally, magnetic recording tapes have been widely used because they are systematically inexpensive and easy to handle.

[0003] In this magnetic recording tape, the characteristics of an information signal, which is a recording source, during recording and reproduction are generally degraded depending on the frequency of use and the state of use, and for example, the recording level of the recorded signal is reduced. is there. Conventionally, in order to determine that such a magnetic recording tape is in a deteriorated state in which it is not ready for use, conventionally, a user of the magnetic recording tape requires a video reproduction signal from the magnetic recording tape to be viewed on a monitor or an audio reproduction signal. To recognize the progress of the degree of deterioration, and finally judge that the magnetic recording tape in use is in a deteriorated state.

[0004] In such a method, there arises a problem that a criterion for judging that the magnetic recording tape is in a deteriorated state varies from user to user and the recording / reproducing characteristics of the magnetic recording tape determined to be in a deteriorated state become unstable. In order to solve such a problem, some methods have been conventionally proposed. First, a system configuration of a conventional magnetic recording / reproducing apparatus will be described.

FIG. 6 is an explanatory diagram of a form of recording information on a magnetic recording tape conventionally used in a magnetic recording and reproducing apparatus. In FIG. 6, J1 is a magnetic recording tape which is a recording medium on which information signals such as sound and images are recorded and reproduced,
Reference numeral 15 denotes an audio signal recording unit which is a recording portion of an audio information signal, 16 denotes a video signal recording unit which is a recording portion of a video signal which is an image information signal, and 17 denotes a phase control when the magnetic recording tape J1 runs. This is a CTL signal recording unit which is a recording part of a control signal (hereinafter, abbreviated as a CTL signal) as a reference.

FIG. 7 is a block diagram showing only a portion corresponding to recording and reproduction of an audio signal as a part of the configuration of a conventional magnetic recording and reproducing apparatus. In FIG. 7, reference numeral 18 denotes an audio input unit, 19 denotes an audio signal processing device, 20 denotes an audio head, 2
1 is an audio output unit, 22 is a system controller, 23,
24 and 25 are internal devices of the system controller 22, 23 is a software controller, 24 is a CTL signal generator, 2
5 is a CTL signal reading unit, 26 is a control (CT
L) Head.

Normally, an audio signal input from an audio input unit 18 passes through an audio signal processing unit 19 and passes through an audio head 20.
Is recorded on the audio signal recording unit 15 of the magnetic recording tape J1. At the time of reproduction, the audio signal recorded in the audio signal recording unit 15 is read by the audio head 20, passes through the audio signal processing device 19, and is output from the audio output unit 21 as a reproduction signal.

At the time of recording / reproducing such an audio signal, the system controller 22 outputs various instructions relating to recording and reproduction to the audio signal processing device 19 in response to an instruction from the software control unit 23, The processing device 19 is controlled. Further, at the time of recording, the CTL signal output from the CTL
6, the CTL signal is recorded on the CTL signal recording unit 17 at the time of reproduction, and the CTL signal recorded on the CTL signal recording unit 17 is read by the CTL head 26 and input to the CTL signal reading unit 25 at the time of reproduction.

The above is the system configuration of a normal magnetic recording / reproducing apparatus. With this configuration, it is not possible to detect the degree of tape deterioration indicating the state of deterioration of the magnetic recording tape. Therefore, a conventional method for detecting the degree of deterioration of a magnetic recording tape will be described below. As the first conventional example, in the case of the VHS format, a method of recording the number of times of reproduction using the VASS signal standard in the CTL signal recording unit 17 and indirectly determining the degree of deterioration of the magnetic recording tape based on the number of times of reproduction recorded. There is.

In the magnetic recording / reproducing apparatus shown in FIG. 7, normally, the CTL signal is output from the video signal recording section 16 at a constant ratio (hereinafter referred to as a duty ratio) and a constant period in the Hi section and the Lo section. Are recorded in the CTL signal recording section 17 in synchronization with the video signal recorded in the CTL signal recording section. This CT
The recording is performed by changing the duty ratio of the L signal.
A signal that is assigned 0 or 1 depending on the difference in duty ratio and can be handled as data is called a VASS signal.

As described above, the prior art 1 is a method of recording the number of times of reproduction in the CTL signal recording unit 17 using the above method, and judging the degree of deterioration of the magnetic recording tape J1 according to the number of times of reproduction. I have. As a second conventional example, there is a method of irradiating the magnetic recording tape J1 with light and determining the degree of deterioration of the magnetic recording tape J1 based on a change in reflected light due to deformation or scratches from the magnetic recording tape J1.

[0012]

However, in the method for detecting the degree of deterioration of a magnetic recording tape as in the above-mentioned conventional example 1,
As described above, the number of reproductions and the reproduction time of the magnetic recording tape are used as the information of the criteria for judging the deterioration of the magnetic recording tape. It cannot be determined only by itself, and is actually affected by the operating state of the magnetic recording / reproducing apparatus for recording / reproducing to / from the magnetic recording tape and the ambient temperature, humidity, etc. which are the surrounding environmental conditions at the time of the recording / reproducing. .

In addition, the condition other than the number of times of reproduction and the reproduction time of the magnetic recording tape, such as deterioration while the magnetic recording tape is left in a place affected by magnetism, not in the state where the magnetic recording tape is actually recorded and reproduced, is used. No degradation is detected that is affected by. Therefore, it cannot be said that the number of times of reproduction or the reproduction time of the magnetic recording tape does not always coincide with the deterioration state, and the degree of deterioration of the magnetic recording tape cannot be detected in accordance with the recording position, and the deterioration of the magnetic recording tape cannot be detected. There was a problem that the state could not be reliably determined.

In the method for detecting the degree of deterioration of a magnetic recording tape as in the above-mentioned conventional example 2, the degree of deterioration corresponding to physical deformation and scratches on the magnetic recording tape can be detected. Only the degree of deterioration can be detected,
Since the degree of electrical deterioration such as a decrease in the recording level of the magnetic recording tape cannot be detected, the deformation and scratches of the magnetic recording tape do not always match the deterioration state, and the deterioration of the magnetic recording tape does not always match. There has been a problem that the degree cannot be accurately detected, and the state of deterioration of the magnetic recording tape cannot be reliably determined.

The present invention solves the above-mentioned conventional problems, and it is possible to detect the degree of deterioration of a magnetic recording tape accurately and in correspondence with a recording position, so that the state of deterioration of the magnetic recording tape can be reliably and reliably determined. Provided are a magnetic recording tape deterioration degree detection method and a deterioration degree detection device that can be easily determined.

[0016]

SUMMARY OF THE INVENTION In order to solve the above problems, a method and an apparatus for detecting the degree of deterioration of a magnetic recording tape according to the present invention provide an information signal of a recording source when recording on a magnetic recording tape. After removing the high-frequency component from, a high-frequency signal serving as a tape deterioration determination reference signal is always superimposed and recorded, and when reproducing from the magnetic recording tape,
By using the high-frequency signal separated from the reproduction signal as a tape deterioration judgment reference signal, the degree of deterioration of the magnetic recording tape is detected and the deterioration is judged, so that the high-frequency signal actually recorded on the magnetic recording tape is The signal reproduction level is compared with the signal level at the time of recording the high-frequency signal to detect the degree of deterioration of the magnetic recording tape.

As described above, regardless of the running position of the magnetic recording tape, the rate of decrease in the recording level of the high-frequency signal is always obtained from the actual reproduced signal, and the degree of deterioration of the magnetic recording tape is accurately associated with the recording position. Can be detected,
The deterioration state of the magnetic recording tape can be reliably and easily determined.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for detecting the degree of deterioration of a magnetic recording tape according to the first aspect of the present invention is a method for determining the deterioration of a magnetic recording tape as a recording medium by using a recording source for the magnetic recording tape. After removing the high-frequency component from the information signal, a high-frequency signal serving as a tape deterioration determination reference signal for determining the deterioration of the magnetic recording tape is superimposed and recorded on the magnetic recording tape. A method of separating the high-frequency signal from a reproduced signal and using the high-frequency signal as the tape deterioration determination reference signal to detect a degree of deterioration of the magnetic recording tape for determining deterioration of the magnetic recording tape.

According to a second aspect of the present invention, there is provided a magnetic recording tape deterioration degree detecting apparatus for detecting a deterioration degree of a magnetic recording tape as a recording medium in order to determine the deterioration degree. A first low-pass filter that outputs a signal obtained by removing a high-frequency component from an information signal that is a recording source on the magnetic recording tape; and a high-frequency signal generator that generates a high-frequency signal having an arbitrary frequency among the high-frequency components. Device, a high-frequency signal from the high-frequency signal generator is superimposed on an output signal from the first low-pass filter as a tape deterioration determination reference signal for determining deterioration of the magnetic recording tape, and the signal is superimposed. A superimposing circuit for outputting as a recording signal for the magnetic recording tape, and a c for outputting the reproduced signal from the magnetic recording tape by passing the high frequency component therefrom. A high-frequency signal measuring unit that separates a high-frequency signal due to the superposition of high-frequency components from the high-pass filter and measures the same as the tape deterioration determination reference signal; Based on the measurement result of the high-frequency signal measured as the deterioration determination reference signal, the degree of deterioration of the magnetic recording tape is detected, the deterioration is determined, and the magnetic recording tape is warned of deterioration.

A magnetic recording / reproducing apparatus according to a third aspect is a magnetic recording / reproducing apparatus including the magnetic recording tape deterioration degree detecting apparatus according to the second aspect, wherein the magnetic recording / reproducing apparatus is lower than a reproduction signal from the magnetic recording tape. A second low-pass filter that separates and outputs a frequency component is provided, and a low-frequency component from the second low-pass filter is output as an information signal.

According to these methods and configurations, the degree of deterioration of the magnetic recording tape is detected by comparing the reproduction level of the high-frequency signal with the signal level at the time of recording the high-frequency signal. Hereinafter, a method and an apparatus for detecting a degree of deterioration of a magnetic recording tape according to an embodiment of the present invention will be specifically described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a magnetic recording / reproducing apparatus provided with a magnetic recording tape deterioration degree detecting apparatus according to the present embodiment. In FIG. 1, reference numeral 1 denotes an audio input unit, 2 denotes a low-pass filter (hereinafter abbreviated as LPF), 3 denotes a high-frequency signal generator, 4 denotes a superimposing circuit, 5 denotes an audio signal processing device, and 6 denotes an audio signal. Head, 7
Is a low-pass filter (LowPassFilter: hereinafter abbreviated as LPF), 8 is a high-pass filter (Hi
ghPassFilter: H.P. P. F), 9 is an audio output unit, and 10 is a system controller.

Reference numerals 11, 12, and 13 denote internal devices of the system controller 10, and 11 denotes an A / D converter,
2 is a pulse counter section, 13 is a software control section, 14 is an on-screen display (OnScreenDisp).
layer: hereinafter referred to as OSD). An outline of a magnetic recording / reproducing apparatus having the above-described components will be described below mainly with a focus on a magnetic recording tape deterioration degree detecting apparatus.

In the magnetic recording / reproducing apparatus, the degree of deterioration detecting apparatus performs L.O.M. on the basis of an input audio signal, which is an information signal input from the audio input unit 1, when recording on a magnetic recording tape. P.
The signal from which the high frequency component has been removed in F2 is superimposed on
At all times, a high-frequency signal serving as a tape deterioration determination reference signal generated by the high-frequency signal generator 3 is superimposed and then recorded on a magnetic recording tape, and separated from the reproduced reproduction signal when reproducing the magnetic recording tape. The high-frequency signal is compared with the high-frequency signal at the time of recording.
It is configured to detect the degree of deterioration of the magnetic recording tape and determine the state of deterioration.

In this configuration, at the time of recording on the magnetic recording tape J1, the audio signal recording unit 15 of the magnetic recording tape J1 uses a high frequency signal having a constant frequency and a constant amplitude as a tape deterioration determination reference signal, and the audio input unit 1 A composite signal superimposed on a signal from which a high-frequency component has been removed from the input audio signal from the input audio signal is recorded as a recording signal on the magnetic recording tape J1.

When the magnetic recording tape J1 is reproduced, a high-frequency signal separated from the composite signal recorded in the audio signal recording section 15 and taken out is input to the system controller 10 as a tape deterioration judgment reference signal.
At the same time, extract the low frequency signal part from the above composite signal,
It is output from the audio output unit 9 as a normal audio signal. Then, the high-frequency signal input as a tape deterioration determination reference signal to the system controller 10 is compared with the high-frequency signal output from the high-frequency signal generator 3 at the time of recording with respect to their amplitude and frequency. If deterioration of the magnetic recording tape J1 is recognized based on the change or the missing pulse,
1 outputs a warning that it is in a degraded state.

The above is described in detail below.
First, the flow of signals during recording will be described. In order to superimpose a high-frequency signal of an arbitrary frequency among high-frequency components as a tape deterioration determination reference signal on an audio signal which is an information signal of a recording source, an input audio signal input from the audio input unit 1 is subjected to L.P. P. The high frequency component is removed through F2. This signal has a high frequency component of about 2 inaudible to human ears.
To cut and remove the frequency range above 0KHz,
Use as an audio signal does not affect its characteristics.

The software control unit 13 issues a command to output a high-frequency signal serving as a reference signal for tape deterioration determination from the system controller 10 to the high-frequency signal generator 3, and in accordance with this command, the high-frequency signal generator 3 A high frequency signal having a constant frequency and a constant amplitude having a frequency is output as a reference signal for judging tape deterioration. P. The signal from F2 is superimposed and compounded by the superimposing circuit 4. This composite signal passes through the audio signal processing device 5,
It is recorded on the audio signal recording section 15 of the magnetic recording tape J1 through the audio head 6.

Next, the flow of signals during reproduction will be described. An audio signal, which is a reproduction signal fetched from the magnetic recording tape J1 by the audio head 6, passes through the audio signal processing device 5, and one of the signals is transmitted to the L.P. P. An L.F. in which a cutoff frequency similar to that of F.2 is set. P. F7, which outputs only a signal in a frequency range of about 20 KHz or more in order to extract a high-frequency signal as a tape deterioration determination reference signal superimposed during recording from the audio signal. P. Output to F8.

L. P. The output signal from F7 is only a signal component of about 20 KHz or less that can be heard by human ears,
Output from the audio output unit 9. On the other hand, H. P. The signal from which the low-frequency component of about 20 KHz or less has been cut by F8 is input to the A / D conversion unit 11 and the pulse counter unit 12 in the system controller 10 while including the high-frequency signal superimposed during recording. .

The signal level A / D-converted by the A / D converter 11 and the count value of the pulse counter 12 are stored in the L.P. P. The amplitude and frequency of the high-frequency signal superimposed on the signal from F2 are compared with the amplitude and frequency at the time of recording, and the values obtained by quantifying the decrease in the amplitude level, the frequency fluctuation, and the state of missing pulses are integrated and evaluated. The degree of deterioration is detected, and it is determined whether the state is the deterioration state. When it is determined that the magnetic recording tape J1 is in the deteriorated state in this way, a warning message for notifying the user of the tape deteriorated state is displayed on the OSD display unit 14.

Next, the operation of the software control section 13 in the system controller 10 will be described with reference to the drawings. FIG. 2 is a flowchart showing the operation of the software control unit 13 in the system controller 10 for realizing the magnetic recording tape deterioration degree detecting method according to the embodiment of the present invention. FIG. 3 is an explanatory diagram of the signal level degradation judgment in the A / D converter 11, FIG. 4 is an explanatory diagram of frequency fluctuation and pulse missing judgment in the pulse counter 12, and FIG. FIG.

First, as shown in FIG. 2, in the tape deterioration judging process (step S200), at the time of recording, the system controller 10 outputs a command to select the recording side to the audio signal processing device 5 (step S201, S21
2), a high-frequency signal generation command is output to the high-frequency signal generator 3, and a high-frequency signal generated by the high-frequency signal generator 3 and used as a tape deterioration determination reference signal is superposed by the superimposing circuit 4 on the L.P. P. F2
(Step S213).

Next, at the time of reproduction, the system controller 1
0 outputs a command to select the reproduction side to the audio signal processing device 5 (steps S201 and S202). The loop setting is performed N times so that the determination can be made based on the average of the A / D value in the A / D conversion unit 11 and the pulse count value in the pulse counter unit 12 (step S203). This is because if the determination is made based on one measurement value, it is determined at a certain location on the magnetic recording tape, and the evaluation is prevented from being OK or NG by accident.

A predetermined timer is set (step S20).
4), every predetermined period (step S205), P. F
The A / D value input through the A / D converter 11 from 8 and the pulse count input through the pulse counter 12 are stored (step S206). After N loops (step S207), the average of the A / D value and the count value is averaged (step S208), and the average value of the A / D value and the count value and the high frequency used as the tape deterioration determination reference signal. The deterioration of the magnetic recording tape J1 is determined by comparing the difference between the signal and the threshold value (step S209) (step S210).

An example of the tape deterioration evaluation method at this time will be described below. First, as shown in FIG. 3, an average value of A / D conversion values for each fixed period set by a timer is calculated, and a down rate X (%) from a reference value is obtained. Next, as shown in FIG. 4, similarly to the case of the A / D conversion value, the average value of the pulse count value for each fixed period is calculated, and the down rate Y (%) from the reference count value is obtained. . The result is
Apply to the tape deterioration judgment table in FIG.
Judge whether it is K or not.

As a result, when deterioration of the magnetic recording tape is recognized, a display instruction of a tape deterioration warning message is issued to the OSD display unit 14 (step S211). As described above, the degree of deterioration of the magnetic recording tape can be detected by comparing the reproduction level of the high-frequency signal actually recorded on the magnetic recording tape with the signal level at the time of recording the high-frequency signal. .

As a result, irrespective of the running position of the magnetic recording tape, the reduction rate of the recording level of the high-frequency signal is always obtained from the actual reproduced signal, and the degree of deterioration of the magnetic recording tape is accurately and corresponded to the recording position. Thus, the deterioration state of the magnetic recording tape can be reliably and easily determined. Further, when the deterioration of the magnetic recording tape is recognized as described above, it is possible to output a warning that the magnetic recording tape is in a deteriorated state.

As a result, the user of the magnetic recording / reproducing apparatus
It is possible to prevent erroneous recording on a deteriorated portion of the magnetic recording tape.

[0040]

As described above, according to the present invention, when recording on a magnetic recording tape, a high-frequency signal which is always a reference signal for judging tape deterioration after removing a high-frequency component from an information signal of a recording source. Is superimposed and recorded, and at the time of reproduction from the magnetic recording tape, the degree of deterioration of the magnetic recording tape is detected by detecting the degree of deterioration of the magnetic recording tape by using a high frequency signal separated from the reproduced signal as a tape deterioration determination reference signal. By comparing the reproduction level of the high-frequency signal actually recorded on the magnetic recording tape with the signal level at the time of recording the high-frequency signal, the degree of deterioration of the magnetic recording tape is detected. be able to.

Therefore, regardless of the running position of the magnetic recording tape, the reduction rate of the recording level of the high-frequency signal is always obtained from the actual reproduced signal, and the degree of deterioration of the magnetic recording tape is detected accurately and in correspondence with the recording position. The deterioration state of the magnetic recording tape can be reliably and easily determined. Further, when the deterioration of the magnetic recording tape is recognized as described above, it is possible to output a warning that the magnetic recording tape is in a deteriorated state.

Therefore, the user of the magnetic recording / reproducing apparatus
It is possible to prevent erroneous recording on a deteriorated portion of the magnetic recording tape.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a partial configuration of a magnetic recording / reproducing apparatus including a magnetic recording tape deterioration degree detecting apparatus according to an embodiment of the present invention;

FIG. 2 is a flowchart showing a procedure of a magnetic recording tape deterioration degree detecting method according to the embodiment;

FIG. 3 is an explanatory diagram for judging a decrease in a signal level according to the embodiment;

FIG. 4 is an explanatory diagram for calculating a down rate of a pulse counter value in the embodiment.

FIG. 5 is an explanatory diagram of a tape deterioration determination criterion in the embodiment.

FIG. 6 is an explanatory diagram of an information recording form of a magnetic recording tape conventionally used;

FIG. 7 is a block diagram showing a partial configuration of a conventional magnetic recording / reproducing apparatus.

[Explanation of symbols]

1 Voice input unit 2, 7 Low-pass filter (LowPassFilter)
er: L. P. F) 3 high frequency signal generator 4 superposition circuit 5 audio signal processing device 6 audio head 8 high pass filter (HighPassFilter)
r: H. P. F) 9 audio output unit 10 system controller 11 A / D conversion unit 12 pulse counter unit 13 software control unit 14 on-screen display (OnScreen)
nDisplay (OSD) display unit 15 audio signal recording unit 16 video signal recording unit 17 control signal recording unit

Claims (3)

[Claims] When judging deterioration of a magnetic recording tape as a recording medium, a high frequency component is removed from an information signal as a recording source on the magnetic recording tape, and then the deterioration of the magnetic recording tape is judged. A high-frequency signal serving as a tape deterioration determination reference signal is superimposed and recorded on the magnetic recording tape, the high-frequency signal is separated from a reproduction signal from the magnetic recording tape, and the high-frequency signal is converted to the tape deterioration determination reference signal. A method for detecting the degree of deterioration of the magnetic recording tape for detecting the degree of deterioration of the magnetic recording tape. 2. A deterioration detecting device for a magnetic recording tape for detecting deterioration of a magnetic recording tape as a recording medium, the information signal being a recording source for the magnetic recording tape. A first low-pass filter that outputs a signal from which a high-frequency component has been removed, a high-frequency signal generator that generates a high-frequency signal having an arbitrary frequency among the high-frequency components, and an output signal from the first low-pass filter. A superimposing circuit that superimposes a high-frequency signal from the high-frequency signal generator as a tape deterioration determination reference signal for determining deterioration of the magnetic recording tape, and outputs the signal as a recording signal for the magnetic recording tape, A high-pass filter that passes and outputs the high-frequency component from a reproduction signal from the magnetic recording tape; and a high-frequency filter from the high-pass filter. High-frequency signal measuring means for separating the high-frequency signal due to the superposition of the components and measuring the same as the tape deterioration determining reference signal, and the high-frequency signal measured as the tape deterioration determining reference signal by the high-frequency signal measuring means. A magnetic recording tape deterioration degree detecting device configured to detect the deterioration degree of the magnetic recording tape based on the measurement result, determine the deterioration degree, and warn of the deterioration of the magnetic recording tape. 3. A magnetic recording / reproducing apparatus comprising the magnetic recording tape deterioration degree detecting device according to claim 2, wherein a second low frequency component is separated from a reproduction signal from the magnetic recording tape and output. A magnetic recording / reproducing apparatus configured to output the low frequency component from the second low pass filter as an information signal.