JPH01122013A - Magnetic tape cassette - Google Patents

Abstract

PURPOSE:To always keep the sliding surface of a magnetic head clean by storing such a magnetic tape that a tape part with a magnetic layer consisting of chromium dioxide is connected to the ordinary tape. CONSTITUTION:Between a transparent leader tape 15 to be connected to the winding reel hub 13a of a tape cassette and the ordinary magnetic tape 16, a tape part 41 with the magnetic layer consisting of chromium dioxide as a magnetic particle is connected by prescribed length. Since this chromium dioxide particle is ferromagnetic material, at the same time that ordinary recording and reproducing can be performed, the hardness of it is larger compared with the magnetic particle of iron oxide of the ordinary tape. As the result, a cleaning action is elevated by the hard particle, and magnetic powder or abnormal attachment can be wiped away, and the head sliding surface can be always kept clean.

Description

DETAILED DESCRIPTION OF THE INVENTION (Prior Art) Conventionally, magnetic tape cassettes have been used in magnetic recording and reproducing devices such as household VTRs. FIG. 6(b) is a perspective view of the cassette 10, and FIG. 6(b) is a plan view showing the lower half of the magnetic tape cassette shown in FIG. 6(a). FIG. This is an explanatory diagram, and the following description will be made using the same diagram.

Reference numeral 11 denotes a cassette case consisting of an upper half 11a and a lower half 11b, and a supply reel 12 and a take-up reel 13 are rotatably arranged side by side inside the cassette case.

These supply reel 12 and take-up reel 13 are connected to a hub 12a.
, 13a, and these hubs 12a.

One end of a transparent 1-leader tape 14 and a leader arp 15 are connected to 13a, and a magnetic tape section 16 made of a magnetic layer is connected to the other end of these trailer tape 14 and leader tape 15. Hub 12a of supply reel 12 and take-up reel 13.

Although it is wound and stored in i3a, this tab part 16 has a cutout part 17, 18, 19 on the right side of the case 11.
A predetermined tape path 16a is formed on the front surface of the tape. Reference numeral 20.21 denotes a bearing portion formed at the center of the hubs 12a, 13a, and is fitted with a drive shaft on the device side (not shown).

Reference numeral 22 denotes a front cover for protecting the tape bus 16a when not in use. When using, magnetic tape cassette 10
When inserted into the cassette case 11, the front cover 22 is automatically opened and the loading mechanism of the device fitted into the notch 18, 19 is activated to pull out the magnetic tape to the outside of the cassette case 11, and the rotating drum containing the magnetic head is opened. Loading is performed so as to wrap the wire over a predetermined angle range. Recording and reproduction are performed by relative sliding movement between the magnetic head and the magnetic tape as the rotating drum rotates.

Furthermore, inside the cassette case 11 of the magnetic tape cassette 10, a light emitting element 2 is located between both reels 12.1'3.
A light emitting element insertion part 24 into which the light receiving element 3 is inserted is formed, and openings 27.degree. 28 facing the light receiving elements 25 and 26 are formed in the left and right side walls of the cassette case 11. The light emitting element fitting portion 24 is made of a cylindrical wall 29 formed to surround the opening on the damaged surface of the cassette case 11 . A window 30.31 is formed in this cylindrical wall 29 at a position opposite to the opening 27.28.

The light from the light emitting element 23 in the fitting part 24 exits from the window 3o as a light ray 32 and heads towards the opening 27, and also exits from the window 31 as shown by a light ray 33 and heads towards the opening 28.

In a normal state, the light beams 32, 33 are blocked by the tape portion 16 and do not reach the light receiving elements 25, 26, so that both of the light receiving elements 25, 26 are in a non-light receiving state, and the tape end detection means detects the magnetic tape cassette 10. It is determined that the magnetic tape inside is in the normal winding state. When the magnetic tape runs in the forward direction and the transparent trailer tape 14 is pulled out, the light beam 32
The light a32 passes through the trailer tape 14, passes through the opening 27, and reaches the light receiving element 25, and the light receiving element 25 receives the light a32. When the magnetic tape runs in the opposite direction and the transparent leader tape 15 is pulled out, the light beam 33 passes through the league tape 15 and reaches the light receiving element 26 through the opening 28, and the light receiving element 26 receives the light beam 33.

When the light-receiving elements 25 and 26 enter the light-receiving state, the detection means determines that the magnetic tape is wound onto one reel, and stops the tape running system. The end of the magnetic tape is detected in the manner described above. (Problem to be solved) When the magnetic tape cassette 10 is installed in a device and recording and reproduction are repeated many times, powder falls off the magnetic tape due to the relative sliding contact between the magnetic head and the magnetic tape, and this may adhere to the sliding surfaces of the machine or cause clogging.

When these phenomena occur, the magnetic gap located at the tip R of the training surface of tape 1 rises from the magnetic tape, and as a result,
During recording, the signal is not sufficiently recorded on the magnetic tape, and
During reproduction, the reproduction output decreases due to spacing loss, and in either case there is a problem in that good images cannot be obtained.

In recent years, the performance of magnetic tapes and magnetic heads has improved significantly.
VTRs with higher image quality and higher resolution are now on the market, but this was made possible by significantly shifting the conventional carrier frequency to higher frequencies and improving single-wavelength recording and playback characteristics. Therefore, it is expected that the decrease in output J due to the above-mentioned spacing loss will cause more deterioration of image quality than before. Conventionally, when such adhesion or clogging phenomenon occurred on the sliding surface, a commercially available cleaning tape cassette containing a built-in cleaning tape was installed in the VTR to remove the adhesion from the surface of the magnetic head and restore it to its original condition. However, with this method, in addition to the tedious work of installing a cleaning tape cassette each time, the user must judge whether or not to perform cleaning by looking at the TV screen. In the worst case scenario, if the device is dropped and left unattended, it may no longer be possible to perform good recording or playback, leading to inconveniences such as being mistaken for failure.

(Means for Solving the Problems) The present invention has been made to solve the above-mentioned problems, and includes a first magnetic tape portion having a magnetic layer portion made of aluminum dioxide as magnetic particles, and magnetic particles. Another object of the present invention is to provide a magnetic tape cassette characterized in that a magnetic tape having a second magnetic tape section having a magnetic layer section made of magnetic particles other than chromium dioxide is housed in a cassette case. be.

(Embodiment) FIG. 1 is an explanatory diagram for explaining the structure of a magnetic tape built in a magnetic tape cassette 40 in a first embodiment of the present invention. 6
Components that are the same as those of the conventional magnetic tape cassette 10 shown in FIGS.

In the first embodiment of the present invention, the difference from the conventional magnetic tape cassette 10 is that chromium dioxide (chromium dioxide) is used as the magnetic particles.
A first magnetic groove portion 41 having a magnetic layer portion made of Cr203) is connected to the winding reel hub 13a, and the other end of the transparent leader tape 15 is connected to a magnetic layer made of iron oxide or a ferromagnetic metal as magnetic particles. The point is that a fixed length (for example, a length that runs for about several seconds in the standard mode) is provided between one end of an ordinary magnetic tape 16 having a section.

Since the Cr 02 particles (coercive force Hc -7500e, particle length f = 0.3 μm, acicularity ratio 15) used as the magnetic particles of the first magnetic tape section 41 are ferromagnetic, normal recording and reproduction can be performed. Its hardness is also greater than that of magnetic particles such as iron oxide or ferromagnetic metal, and its ability to clean the moving surface of the magnetic head is extremely high.

The magnetic layer of the ordinary magnetic tape section 16 contains CO-7F203.
Particles (retention square (C = 9000e, particle size, i;
= 0.18 μm, acicular ratio 10) was used.

As a comparative example for this first embodiment, a conventional magnetic tape cassette without the first magnetic tape section 41 was prepared,
It is attached to a specified VTR with a built-in magnetic head that has problems with adhesion to sliding surfaces and clogging, and performs recording and playback to visually evaluate the image quality, etc., and to check the S of the luminance signal.
/N was compared. The results are shown in Table 1.

However, ○ mark indicates that it is within the allowable range, Δ mark indicates that it is within the allowable range, and
The mark indicates that it is not acceptable.

As is clear from Table 1, the first embodiment of the present invention has inversion noise, edge noise, and overall image quality within the permissible range, while the comparative example has inversion noise within the allowable limit, but edge noise and overall image quality are within the allowable range. Both the image quality is unacceptable and the luminance signal S/N is 3 d [3 to 4] compared to that of the first embodiment.
It has gotten worse by about d13.

Furthermore, when the sliding θJ surfaces of these magnetic heads were observed under a microscope after the experiment, it was found that the first example recovered to a nearly clean state, but the comparative example had residual abnormalities A.14. . The reason for this is that Cr02 particles with high hardness are used as magnetic particles in the magnetic layer portion of the first magnetic tape portion 41, so that the first magnetic tape portion 41 removes abnormal deposits from the magnetic head moving surface. This is thought to be because it has a cleaning effect.

Furthermore, the first magnetic tape section 41 does not necessarily need to be provided next to the leader chip 115, and the location, length, etc. of the first magnetic tape section 41 may be determined as appropriate. This first magnetic tape section 41 can perform almost the same recording and reproduction as the ordinary magnetic tape section 16.

FIGS. 2 to 5 are explanatory diagrams for explaining the structure of the magnetic tapes of the magnetic tape cassettes 50, 60, 70.degree. 80 in the second to fifth embodiments, respectively.

In the second embodiment shown in FIG. 2, the first magnetic tape section 41 is arranged between the leader tape 15 end and the iris magnetic tape section 16 end, and between the trailer tape 14 end and the circulating magnetic tape section 16.
They are installed in two places between the ends.

In the third embodiment shown in FIG.
It is provided between the six ends.

In the fourth embodiment shown in FIG.
It is provided in the middle so as to divide this magnetic tape into two.

This is effective for the latter half of the magnetic tape when used as a tape for a long time.

The fifth embodiment shown in FIG. 5 is a combination of the second embodiment and the fourth embodiment.

These glue-like functions and effects are substantially the same as those of the first embodiment, so explanations will be omitted. However, as described above, the first magnetic tape section 41 is
- between the railer tape 14 and the ordinary magnetic tape section 16;
Alternatively, since it is provided approximately at the center of this ordinary magnetic tape section 16, the light rays 32.degree. It is possible to detect the edge of an arp by receiving light, and it can be used with a conventional video arp recorder etc. to maintain compatibility for years without causing problems. Since the detection mechanism does not operate, the first tape section can be reliably prevented from running in contact with the drum and the sliding surface of the magnetic head can be cleaned, so that recording and reproduction can always be performed in good conditions.

(Effects of the Invention) As described above, the magnetic tape force hit according to the present invention has a first magnetic layer having a magnetic layer portion made of chromium dioxide as magnetic particles.
Since the magnetic tape comprising the magnetic tape and the second magnetic tape part having the magnetic layer part made of iron oxide or ferromagnetic metal as magnetic particles was housed in the cassette case, when it is used, the first magnetic tape part and As a result of the relative sliding movement between the magnetic head and the magnetic head, the cleaning effect of the first magnetic tape section wipes away abnormal deposits on the sliding surface of the magnetic head, and the magnetic head cleans the sliding surface. It is possible to keep it constant, and there is no clogging.
Therefore, there is no need to prepare a cleaning tape, and good images can always be enjoyed, and further, recording and reproduction can be performed even on the first magnetic tape section.

[Brief explanation of the drawing]

Figure 1 shows the magnetic tape force set 1 of the first embodiment of the present invention.
2 to 5 are explanatory diagrams for explaining the structure of the magnetic tape built in the magnetic tape cassettes of the second to fifth embodiments, respectively. 6(a) is a perspective view of a magnetic tape cassette used in a VTR, FIG. 6(b) is a plan view showing the lower half of the magnetic tape cassette in FIG. 6(a), and FIG. FIG. 6 is an explanatory diagram of the magnetic tape built into the 1VAK disk drive shown in FIG. 6; 11... Cavit case, 12.13... Reel,
14...Transparent trailer tape, 15...Transparent leader tape, 16...Ordinary magnetic tape section (second magnetic tape section), 40,50,60,70.80...Magnetic tape J t cut, 41...first magnetic tape section. ! '7ffi::'Δ=

Claims (3)

[Claims] (1) A magnetic tape comprising a first magnetic tape portion having a magnetic layer portion made of chromium dioxide as magnetic particles and a second magnetic tape portion having a magnetic layer portion made of magnetic particles other than the chromium dioxide as magnetic particles. A magnetic tape cassette characterized by being stored in a cassette case. (2) The magnetic tape cassette according to claim 1, wherein the first magnetic tape section is provided at at least one end of the second magnetic tape section. (3) A magnetic tape cassette according to claim 1, wherein the first magnetic tape section is provided between the second magnetic tape sections so as to separate the first magnetic tape section.