JPH03144917A - Magnetic recording medium test instrument - Google Patents

Abstract

PURPOSE:To obtain the result of a test with high correlation with the durability test using a practical use VTR by the use of a practical use VTR and providing a dummy head made of a ceramics material in place of a magnetic head of the practical use VTR. CONSTITUTION:A practical use VTR is used and a dummy head made of a ceramic material easily worn out in place of a magnetic head of the said VTR is provided. The result of th durability test of a magnetic tape and a magnetic head largely depends on conditions of a tape running system such as a tape running tension of a practical use VTR and surface roughness of a cylinder or the like of the practical use VTR used for the test. Thus, the tape running system of the practical use VTR is used as it is to eliminate a problem of the difference from the tape running system being a cause to dispersion in the result of test and the test time is reduced by using a dummy head made of a ceramic material easily worn out, then the test has a high correlation with the result of durability test using the practical use VTR and the result is obtained in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a testing device for magnetic recording media, and more particularly to an accelerated durability testing device for magnetic tapes.

BACKGROUND OF THE INVENTION Conventionally, durability tests for 6R tapes and magnetic tapes are usually conducted using a practical video tape recorder (hereinafter abbreviated as VTR). However, such testing methods require a large amount of time for testing, have low productivity, and are not very useful. Therefore, measures have been taken to increase the tape running tension of practical VTRs and to use testing machines for accelerated testing to obtain results quickly.

Problems to be Solved by the Invention However, in the method of increasing the tape running tension of a practical VTR as described above, the contact pressure of the tape against the head increases, making it easier for the tape (n-type layer) to fall off and the falling powder to fall off. If it adheres to the tape sliding surface of the head, it will prevent the head from wearing out.

Furthermore, when using a testing machine for accelerated testing, the tension that is applied when running the tape of a practical VTR according to the Fl characteristics of the tape, that is, the tape running tension, which is one of the causes of head wear, is ignored. It turns out. Due to these reasons, conventional acceleration methods have a problem in that the correlation between the obtained results and the test results usually performed using actual machines is low.

SUMMARY OF THE INVENTION In view of the above problems, it is an object of the present invention to provide a magnetic recording medium testing device that has a high correlation with the durability test results using a practical VTR and can perform tests in a short time and at low cost.

Means for Solving the Problems In order to solve the above problems, the magnetic recording medium testing device of the present invention uses a practical VTR and provides a dummy head made of a ceramic material that is easily worn out in place of the magnetic head of the practical VTR. It is something.

The results of durability tests on working magnetic tapes and magnetic heads vary greatly depending on the conditions of the tape running system, such as the tape running tension of the practical VTR used in the test and the surface roughness of the cylinder.

By using the tape running system of a practical VTR as is, the present invention eliminates the problem of differences in the tape running system, which causes variations in test results, and further reduces test time by using a dummy head made of a ceramic material that easily wears out. Since it is carried out by using a practical VTR, there is a high correlation with the durability test results using a practical VTR, and the results can be obtained in a short time.

Example Hereinafter, one embodiment of the present invention will be specifically described.

Example 1 A ceramic block containing calcium titanate as a main component was processed by slicing to obtain a .\rad chip with a thickness of 80 μm. Then, a dummy head is obtained by cylindrical polishing the magnetic tape sliding surface of this head chip. The cut surface of this dummy head was attached to the head base with adhesive, and the head was replaced with a magnetic head from a practical 8 mm VTR (MVS-5000, manufactured by Koda Inc.), and the amount of protrusion of the dummy head from the cylinder surface was determined by Same as for head <3
A durability test was conducted using a magnetic recording medium testing apparatus according to the present invention, which was adjusted to 0 μm.

Example 2 A durability test was conducted in the same manner as in Example 1, except that the dummy head material in Example 1 was changed from ceramics containing calcium titanate as a main component to ceramics containing aluminum oxide as a main component.

Comparative Example 1 A durability test was conducted using a practical 8 mm VTR (MVS=5000, manufactured by Kodak).

Comparative Example 2 Practical 8m VTR (MVS-5000,: 2 dy'))
The tape running tension of 20g on the normal tape entry side is 4.
A durability test was conducted by increasing the weight to 0g.

Example 3 The procedure was the same as in Example 1 except that a practical VH3 type VTR (NV-FSI, manufactured by Matsushita Electric Industrial Co., Ltd.) was used instead of the practical 8 mm VTR in Example 1, and the dummy head protrusion amount was set to 45 μm. A durability test was conducted.

Example 4 A durability test was conducted in the same manner as in Example 3, except that the dummy head material in Example 3 was changed from ceramics containing calcium titanate as a main component to ceramics containing aluminum oxide as a main component.

Comparative Example 3 A durability test was conducted using a practical VH3 type VTR (NV-FSI, manufactured by Matsushita Electric Industrial Co., Ltd.).

The magnetic tapes used in the durability test were Example 1 and Example 2.
, Comparative Example 1 and Comparative Example 2 are three types of metal video tapes MPI, MP2 and MP3 among various grades of commonly used commercial products, and Example 3
, Example 4 and Comparative Example 3 are three types of VHS standard tapes SDI, SD2 and SD3 out of various grades of commonly used commercial products.

All durability tests were conducted at a temperature of 40°C and a humidity of 80% R1 (
Continuous writing was performed for 150 hours in each case, and the amount of wear on the head was measured and the amount of powder adhering to the head was observed. The amount of head wear was measured by measuring the distance from the cylinder surface to the tip of the head using a microscope. The amount of powder adhesion was observed using a microscope and evaluated on a five-point scale. The evaluation was rated 5 if there was no practical problem at all, and 1 if there was a problem in practical use. The results obtained are shown in Tables 1 and 2.

(Left below) Table 1 Table 2 From Tables 1 and 2, the test results using the magnetic recording medium testing device according to the present invention show a high correlation with the test results using a practical VTR, and the test results are approximately 115. It can be seen that results can be obtained in a short period of time.

Note that the same effect can be obtained even when any one of an oxide ceramic material, a carbide ceramic material, a silicide ceramic material, and a nitride ceramic material other than the examples is used as the dummy head material.

As described in detail, according to the present invention, a practical VTR is used, and a dummy head made of a ceramic material that is easily worn out is provided in place of the magnetic head of the practical VTR.
This has the advantage that the test results show a high correlation with the durability test using a practical VTR, and the test can be conducted in a short time and at low cost.

Claims (1)

[Claims] 1. A magnetic recording medium testing device for testing acceleration durability by sliding a magnetic tape in contact with and running a dummy head provided on a video tape recorder, characterized in that a ceramic material is used as the dummy head material.