JPH0460977A - Magnetic recording medium testing device - Google Patents

Abstract

PURPOSE:To facilitate high correlation between a durability test using a VTR for practical use and a tested result and to execute the test in a short time by providing a dummy rotary head drum arranging a grinding tape instead of the rotary head drum of the VTR for practical use. CONSTITUTION:The VTR for practical use is used, and instead of the rotary head drum of the VTR for practical use, the dummy head drum is provided while arranging the grinding tape on the magnetic tape travelling surface of the rotary head drum. Namely, since the tape traveling system of the VTR for practical use is used as it is, it is possible to eliminate problems such as the difference of the tape travelling system to cause the fluctuation in the tested result. Further, the time for test is shortened by using the dummy rotary head drum arranging the grinding tape on the magnetic tape travelling surface where head particles and head drum particles are easily stuck. Thus there is high correlation with the result of the durability test using the VTR for practical use, and the result can be obtained in a short time.

Description

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

BACKGROUND OF THE INVENTION Conventionally, durability tests of magnetic tapes have been carried out using video tape recorders (hereinafter abbreviated as VTRs) that are in practical use. However, such testing methods require a large amount of time for testing, have low productivity, and are not very useful. Therefore, especially in durability tests regarding the coating strength of magnetic layers, methods have been taken to increase the tape running tension of practical VTRs and to use testing machines for accelerated tests to obtain results quickly.

Problems to be Solved by the Invention However, in the above-described method of increasing the tape running tension of a practical VTR, the contact pressure of the tape against the head increases, making it easier for the tape magnetic layer to fall off, and the falling particles to the head. If it adheres to or interposes on the tape sliding surface, the head/tape will be in a non-contact state. When using an acceleration tester that increases running tension, practical V
The effect of tape running tension, which is one of the causes of powder adhesion on the head drum and other particles on the running system, is ignored. It turns out. Due to these reasons, the conventional acceleration method has 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, an object of the present invention is to provide a magnetic recording medium testing device that has a high correlation with durability test results using a practical VTR, particularly with magnetic layer coating strength, and can perform tests in a short time and at low cost. There is a particular thing.

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 polishes the magnetic tape running surface of the rotary head tram instead of the rotary head drum of the practical VTR. It is equipped with a dummy rotating head drum with a tape placed on it.

The results of the durability test of working magnetic tapes 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 head drum.

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 are factors that cause variations in test results, and further reduces the test time, resulting in head dregs adhesion and head drum powder adhesion. Since this is carried out by using a dummy rotating head tram with an abrasive tape placed on the magnetic tape running surface, the results are highly correlated with the durability test results using a practical VTR, and the results can be obtained in a short time.

Example Examples of the present invention will be specifically described below.

Example 1 M made by Nippon Micro Coating ■ whose main component is alumina
An IPOX polishing tape WA-10000 is attached to the magnetic tape running surface of the rotary head drum to obtain a dummy rotary head drum. This dummy rotating head drum has a practical power of 8mmV.
A durability test was conducted using a magnetic recording medium testing apparatus according to the present invention in which the rotating head drum of TR (MVS-5000, manufactured by Kodak) was replaced.

Example 2 The abrasive tape of Example 1 was replaced with WA containing alumina as the main component.
-10000 to GC-80 whose main component is silicon carbide
A durability test was conducted in the same manner as in Example 1 except that the value was changed to 00.

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

Comparative Example 2 The tape running tension of a practical 8mm VTR (MVS-5000, manufactured by Kodak) was changed from 20g to 40g on the normal tape entry side.
Durability tests were conducted by increasing the amount of g.

Example 3 Instead of the practical 8+nm VTR in Example 1, a practical VH3
A durability test was conducted in the same manner as in Example 1 except that a VTR (NV-FS I, manufactured by Matsushita Electric Industrial Co., Ltd.) was used.

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

The magnetic tapes used in the durability test were Example 1 and Example 2.
．． Comparative Examples 1 and 2 are three types of metal video tapes MPI, MP2 and MP3 out of various grades of commonly used commercial products, and Example 3
And for Comparative Example 3, three types of VH3 standard tape SD1. SD2 and SD3.

All durability tests were conducted at a temperature of 40°C and a humidity of 80% R-H.
The magnetic tape was heated for 10 minutes in Examples 1 to 3, and for Comparative Example 1. Comparative Example 2: 150 hours; Comparative Example 3:
Each was run continuously for 200 hours, and then the amount of powder adhesion was observed and the surface roughness of the magnetic layer of the magnetic tape was measured. The amount of powder adhesion was observed by visually observing the polishing tape in the case of Examples, and by observing the running surface of the magnetic tape of the magnetic head with a microscope in the case of Comparative Examples, and was 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 surface roughness of the magnetic layer was measured before and after the durability test using a Christetsub type surface roughness meter manufactured by Taylor-Hobhun. The value was calculated by calculating the root mean square of the peak height in the roughness chart, and the rate of change after the test relative to before the test was determined.

The results obtained are shown in Tables 1 and 2.

Bottom margin) 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 results can be obtained in a short time. I understand. Note that similar effects can be obtained even when using a polishing tape containing iron oxide as a main component or a polishing tape containing chromium oxide as a main component other than those in the examples.

As described in detail, according to the present invention, a practical VTR is used, and head drum dregs and magnetic head powder adhere to the magnetic tape running surface of the rotating head drum instead of the rotating head drum of the practical VTR. By providing a dummy rotating head drum with abrasive tape for ease of use, practical V
Durability tests using TR and test results show a high correlation,
Another advantage is that the test can be conducted in a short time.

Claims (1)

[Claims] A dummy rotary head drum having an abrasive tape arranged on the magnetic tape running surface of the rotary head drum is provided in the video tape recorder, and the magnetic tape is slid onto the dummy rotary head drum and run to test acceleration durability. Features of magnetic recording media testing equipment.