JPH04366489A - Service frequency alarm for magnetic tape - Google Patents

Abstract

PURPOSE:To judge aging of a magnetic tape corresponding to both of the frequency of repeating the recording and reproduction and a running speed of a magnetic tape. CONSTITUTION:A position detector 1 outputs a position detection signal (a) when a magnetic tape reaches a specified position. A speed control circuit 4 outputs a speed signal (b) indicating a running speed. A detection counter 2 counts the frequency at which the position detection signal (a) is outputted from the position detector 1 to output a detection frequency signal (c) to an alarm 5. A limit frequency setting device 3 determines the limit of the frequency at which the position detection signal (a) passes by the speed signal (b) when the position detection signal (a) is inputted. The alarm 5 gives an alarm when the frequency indicated by the detection frequency signal (c) exceeds the frequency indicated by the limit frequency signal (d). This enables judgment of aging of the magnetic tape corresponding to both of the frequency of repeating the recording and reproduction and a running speed of the magnetic tape.

Description

[Detailed description of the invention]

[Object of the invention]

0002

[Field of Industrial Application] The present invention relates to a magnetic tape use count warning device for a videotape recorder, and in particular, the present invention relates to a magnetic tape use count warning device for a videotape recorder, and in particular, it is capable of appropriately setting the time to replace the magnetic tape and the time to check the degree of deterioration. Regarding warning devices.

0003

[Prior Art] Generally, video tape recorders (hereinafter referred to as V
(TR), the magnetic head and magnetic tape are in contact, so recording or playback may cause the magnetic material on the surface of the magnetic tape to peel off, or the magnetic material on the magnetic tape or on the tape may peel off. The binder that holds it in place peels off,
It can stick to the magnetic head and cause clogging. Such a phenomenon causes deterioration of the magnetic tape and the magnetic head, which causes problems such as deterioration of image quality and, in the worst case, the inability to perform recording and reproduction.

For example, a VHS type VTR has two magnetic heads attached to a cylindrical cylinder that rotates at a constant speed, and records and plays back while running a magnetic tape wound around the cylinder at a low speed. Therefore, during normal recording and reproduction, each magnetic head contacts the magnetic tape alternately, but since the magnetic tape is running, they do not contact the same position. However, when the running speed of the magnetic tape slows down, such as during slow playback, the contact areas overlap. Therefore, the deterioration of a magnetic tape is determined by the running speed of the magnetic tape, that is, the recording and reproducing speed.

[0005] Many surveillance VTRs perform intermittent recording to enable long-term recording. The surveillance VTR also has a function to repeatedly record a single magnetic tape from beginning to end. In this case VTR
Users often set the recording mode to repeat recording until a situation arises in which they need to check the recorded video. For this reason, when playing back for confirmation after a long period of repeated recording, if the magnetic tape or magnetic head has deteriorated, the reproduced image may become difficult to view or may not be output. Such a phenomenon causes a fatal functional decline in a surveillance VTR that requires confirmation of the details of the video.

[0006] As a protection measure against the deterioration of magnetic tapes as described above, a function is used to record the number of recordings and reproductions performed on a single magnetic tape. Among VTRs having such a function of recording the number of times a magnetic tape has been used and a function of repeating playback, some have a function of limiting the number of times of repeat playback. However, such a number-limiting function is a function that automatically stops when the number of repeated reproductions exceeds a set value, regardless of the reproduction speed, and therefore does not cope with deterioration of the magnetic tape that changes with speed.

[0007] On the other hand, VTRs for business use, including those used for monitoring purposes, are often equipped with a total usage time meter, but this does not indicate deterioration of the magnetic tape, but rather indicates the time required to replace magnetic heads, motors, etc. It is used as a guideline. In this case, when starting to use a new magnetic tape, it is necessary to memorize the value of the cumulative usage time meter and compare it with the value of the current usage time meter, and the length of the magnetic tape must also be considered, which is very troublesome. .

[0008]

[Problem to be solved by the invention] The above-mentioned conventional VTR
In order to protect magnetic tapes from deterioration, the measures to protect against deterioration of magnetic tapes include recording the number of recordings and playbacks performed on a single magnetic tape, and using the cumulative usage time meter as a guide, and checking the cumulative usage time when starting to use a new magnetic tape. There is a method that stores the value and compares it with the value of the current usage time meter, but the former cannot cope with the deterioration of the magnetic tape that changes with speed, and the latter also takes into account the length of the magnetic tape. It is very troublesome to set the time.

The present invention eliminates the above-mentioned problems and provides a magnetic tape use number warning device that can judge the deterioration of a magnetic tape in accordance with both the number of repetitions of recording and playback and the running speed of the magnetic tape. purpose.

[Configuration of the invention]

[0011]

[Means for Solving the Problems] A magnetic tape use count warning device according to the present invention includes a position detection means for detecting passage of a specific position of the magnetic tape, and a speed detection means for detecting the running speed of the magnetic tape. , a detection counter for counting the number of detections of passage of the specific position by the position detection means; a limit number setting circuit for setting a limit for the number of detections counted by the detection counter; , a warning means for issuing a warning when the limit of the number of detections set by the limit number setting circuit is exceeded; and a number of detections counted by the detection counter and the limit number setting according to the detection result of the speed detecting means. The present invention is characterized by comprising circuit means for correcting at least one of the limits of the number of detections set by the circuit.

0012

[Operation] According to such a configuration, the detection counter counts the number of times the position detection means detects passage of a specific position, and the number of detections counted by the detection counter corresponds to the detection result of the speed detection means. Since at least one of the detection number limit set by the limit number setting circuit and the number of detection times is corrected, deterioration of the magnetic tape can be determined in accordance with both the number of repetitions of recording and playback and the running speed of the magnetic tape. .

[0013]

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a magnetic tape use count warning device according to the present invention.

In FIG. 1, a position detector 1 detects the position of the magnetic tape by measuring the number of revolutions of a reel that winds the magnetic tape (not shown), and detects a position detection signal a when the magnetic tape reaches a specific position. It is output to the counter 2 and the limit number setting circuit 3. The speed control circuit 4 controls the running speed of the magnetic tape during recording, and also has a function as speed detection means, and outputs a speed signal b indicating the running speed to the limit number setting circuit 3. The detection counter 2 counts the number of times the position detection signal a is output from the position detector 1 (the number of detections) and outputs a detection number signal c to the warning device 5. The limit number setting device 3 determines the limit of the number of passes based on the speed signal b when the above-mentioned position detection signal a is input from the position detector 1, and outputs a limit number signal d to the warning device 5. The warning device 5 provides a visual display using a liquid crystal display, a light emitting diode, etc., or issues a warning with a sound such as a buzzer when the number of times indicated by the detection number signal c exceeds the number indicated by the limit number of times signal d.

The operation of this embodiment will be explained below.

When the magnetic tape is being recorded at a standard speed (standard mode), the position detector 1 outputs a position detection signal a when the magnetic tape reaches a specific position. The limit number setting circuit 3 receives the position detection signal a and the speed signal b output by the speed control circuit 4, and sets and outputs the limit number signal d to 300 times at the standard speed. Here, the number of detections by the detection counter 2 at this time is assumed to be 1. After this, when the magnetic tape is recorded to the end, the magnetic tape is rewound to the beginning. Then, when recording is performed again and the position detector 1 detects a specific position and outputs the position detection signal a, the detection counter 2 sets the number of detections to 2 and outputs the detection number signal d. When this is repeated and the number of detections indicated by the detection number signal c exceeds 300, the warning device 5 issues a warning.

When the magnetic tape is running at 1/3 the standard speed (3x mode), the position detector 1 outputs a position detection signal a when the magnetic tape reaches a specific position. The limit number setting circuit 3 receives the position detection signal a and the speed signal b outputted by the speed control circuit 4, and sets the standard one.
When the speed is /3, the limit number of times signal d is set to 100 times and output. Here, the detection counter 2 at this time assumes the number of detections to be 1. After recording the magnetic tape to the end, rewind the magnetic tape to the beginning. Then, when recording is performed again and the position detector 1 detects a specific position and outputs the position detection signal a, the detection counter 2 sets the number of detections to 2 and outputs the detection number signal d. When this is repeated and the number of detections indicated by the detection number signal c exceeds 100, the warning device 5 issues a warning.

As described above, by changing the limit of the number of passes according to the running speed of the magnetic tape when passing a specific position, and issuing a warning when the pass exceeds the above limit, Deterioration of the magnetic tape can be determined based on both the number of repetitions of recording and playback and the running speed of the magnetic tape, and the time to replace the magnetic tape and the time to check the degree of deterioration can be appropriately set and notified to the user. Can be done.

In the embodiment shown in FIG. 1, the position detector 1 for detecting the position of the magnetic tape was designed to detect a specific position between the beginning and end of the magnetic tape.
The position detector 1 may detect the beginning of the magnetic tape, and the limit number setting circuit 3 may make the determination based on the speed signal b after the detection.Also, when the position detector 1 detects the end of the magnetic tape, , the limit number setting circuit 3 may make the determination based on the speed signal b before detection.

FIG. 2 is a block diagram showing another embodiment of the magnetic tape use count warning device according to the present invention, in which the same components as in FIG. 1 are given the same reference numerals.

In one embodiment shown in FIG. 1, a limit on the number of passes is set according to the running speed of the magnetic tape, but in another embodiment shown in FIG. By weighting the number of passes, it is possible to change the limit on the actual number of passes.

In FIG. 2, the position detector 1, speed control circuit 4 and warning device 5 are the same as in the embodiment of FIG. The difference in this embodiment is that the limit number setting circuit 13 outputs a fixed limit number d1 regardless of the speed signal b, and the detection counter 12 weights one position detection signal a by the speed signal b. This is because the system is configured to perform the counting process. Specifically, the detection counter 12 multiplies the number of detections of the position detection signal a by a coefficient half proportional to the running speed of the magnetic tape indicated by the speed signal b, and outputs the detection number signal c1. do.

The operation of this embodiment will be explained below.

For example, if the number limit is set to 300 times at the standard speed, and the running speed of the magnetic tape is 1/3 of the standard speed, the detection counter 12 will respond to one position detection signal a. The number of detections is counted assuming that it has been detected three times. As a result, if the vehicle is traveling at 1/3 speed, the warning device 5 issues a warning after passing 100 times, so the result is the same as a change in the limit of the number of passes. In addition, with this method, even if the traveling speed is changed every time a specific position is detected, the number of passes will depend on the traveling speed, that is, the wear of the magnetic tape, so a warning corresponding to the wear of the magnetic tape will be issued. will be held.

In this embodiment as well, the deterioration of the magnetic tape can be determined in accordance with both the number of repetitions of recording and reproduction and the running speed of the magnetic tape, and the same effects as in the embodiment of FIG. 1 can be obtained.

In one embodiment shown in FIG. 1, a limit on the number of passes is set in accordance with the running speed of the magnetic tape, and in another embodiment shown in FIG. However, at the same time, we set a limit on the number of times the magnetic tape passes depending on the running speed of the magnetic tape.
The number of detections may be weighted depending on the standard speed of the magnetic tape.

[0028]

[Effects of the Invention] According to the present invention, it is possible to judge the deterioration of a magnetic tape based on both the number of repetitions of recording and playback and the running speed of the magnetic tape, thereby confirming the time to replace the magnetic tape and the degree of deterioration. The timing can be set appropriately and notified to the user.

[0029]

[Brief explanation of drawings]

[0030]

FIG. 1 is a block diagram showing an embodiment of a magnetic tape use count warning device according to the present invention.

[0031]

FIG. 2 is a block diagram showing another embodiment of the magnetic tape use count warning device according to the present invention.

[0032]

[Explanation of symbols]

1 Position detector 2 Detection counter 3. Limit number of times setting circuit 4 Speed control circuit 5 Warning device

Claims (1)

[Claims] 1. A position detecting means for detecting passage of a specific position of a magnetic tape, a speed detecting means for detecting a running speed of the magnetic tape, and a detection number of times of passage of the specific position by the position detecting means. a detection counter that counts, a limit number setting circuit that sets a limit on the number of detections counted by the detection counter, and a number of detections counted by the detection counter that exceeds a limit on the number of detections set by the limit number setting circuit; and a warning means for issuing a warning when the speed is detected, and at least one of the number of detections counted by the detection counter and the limit of the number of detections set by the limit number setting circuit is corrected in accordance with the detection result of the speed detecting means. What is claimed is: 1. A magnetic tape use count warning device, comprising circuit means.