JPH01122012A - Magnetic tape cassette - Google Patents

Abstract

PURPOSE:To always keep the sliding surface of a magnetic head clean without using a cleaning tape by storing such a magnetic tape that a cleaning part to clean the head sliding surface 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, the prescribed length of the cleaning tape part 41 to clean the head sliding surface is connected. The tape part 41 consists of a cleaning layer whose principal component is the Cr2O3 particle of mesh #10000, and its thickness is made more or less 15mum. By the cleaning action of this cleaning tape part 41, magnetic powder or abnormal attachment, impossible to be wiped away by the ordinary tape 16, can be removed, and the head sliding surface can be always kept clean without using the cleaning tape.

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. Figure 6 (
6(a) is a perspective view of a magnetic tape cassette 10 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. 2 is an explanatory diagram of a magnetic tape built into the magnetic tape cassette shown in FIG.

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-railer tape 14 and a leader tape 15 are connected to 13a, and a magnetic tape section 16 made of a magnetic layer section 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.

The tape portion 16 is wound and stored in the cassette case 13a, and this tape portion 16 forms a predetermined tape bus 16a on the front surface of the cassette case 11 having notches 17, 18, and 19. 2
0.21 is 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). 22
is a front cover for protecting the tape path 16a when not in use. In use, when the magnetic tape cassette 10 is attached to the device, the front cover 22 is automatically opened and the notch 18 is opened.
．． The loading mechanism on the device side fitted with 19 is activated,
The magnetic tape is pulled out of the cassette case 11 and loaded so as to be wound around a rotating drum containing a magnetic head 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 23 is located between both reels 12 and 13.
A light emitting element fitting part 24 is formed into which the light receiving elements 25 and 26 are fitted, and openings 27 and 28 are formed in the left and right side walls of the cassette case 11, respectively, to face the light receiving elements 25 and 26. 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.

Light from the light emitting element 23 in the first medical school department 24 exits from the window 30 and heads towards the opening 27 as shown by a ray 32, and also exits from the window 31 and heads towards the opening 28 as shown by a ray 33.

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 beam passes through the trailer tape 14 and passes through the opening 27 to reach the light receiving element 25, and the light receiving element 25 receives the light beam 32. When the magnetic tape runs in the opposite direction and the transparent leader chip 715 is pulled out, the light beam 33 passes through the leader tape 15 and passes through the opening 28 to reach the light receiving element 26, 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.

(Problems 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 action between the magnetic head and the magnetic tape, and this causes damage to the magnetic head. It may adhere to sliding surfaces or cause clogging.

When these phenomena occur, the magnetic gap located at the tip R of the tape sliding movement lifts up from the magnetic tape, resulting in insufficient recording of signals on the magnetic tape during recording, and during playback due to spacing loss. Output decreases,
In either case, there was a problem that good images could not be obtained.

In recent years, the performance of magnetic tapes and magnetic heads has improved significantly.
VTRs with higher resolution and higher image quality are now on the market, but this was made possible by significantly shifting the conventional carrier frequency to higher frequencies and improving the recording and reproducing characteristics of shorter wavelengths. Therefore, it is expected that the decrease in output due to the above-mentioned spacing loss will cause more deterioration in image quality than in the past. 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 complication of installing a cleaning tape cassette each time, the user must judge whether or not to perform cleaning by looking at the TV white screen. If overlooked and left unattended, in the worst case scenario, good recording and playback may not be possible, leading to inconveniences such as being mistaken for failure.

(Means for Solving the Problems) The present invention has been made in order to solve the above problems, and is intended to clean the magnetic tape part consisting of a transparent tape part and a magnetic layer, and also the sliding surface of the magnetic head. An object of the present invention is to provide a magnetic tape cassette characterized in that a magnetic tape having a cleaning groove section is housed in a cassette case.

(Embodiment) FIG. 1 is an explanatory diagram for explaining the structure of a magnetic tape built in a magnetic tape cassette 4o 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.

The first embodiment of the present invention differs from the conventional magnetic tape cassette 10 in that a cleaning tape section 41 for cleaning abnormal deposits on the tape active surface of the magnetic head is attached to a winding hub 13a. Connected leader Qi 1
15 and one end of the ordinary magnetic tape section 16 by a certain length (for example, in the first embodiment, the length that runs for several seconds in the standard mode) is provided.

The cleaning tape 41 is made of a cleaning layer mainly composed of mesh #10000 Cr2O3 particles, the total thickness of which is about 15 μm, and the transmittance of light at a wavelength of 9000 is 2% or less.

The magnetic layer of the ordinary magnetic tape section 16 includes, for example, CO-
7Fe 203 particles (coercive force t1c = 9000e,
Magnetic particles with a particle size of Jl-0, 18 μI and an acicular ratio of 10) were used.

As a comparative example to the first embodiment, a conventional magnetic tape cassette without a leaning tape section 41 was prepared, and a predetermined VTR with a built-in magnetic head that had problems with adhesion to sliding surfaces and clogging was prepared. Recording and playback was performed by attaching the camera to the camera, and the image quality and other conditions were visually evaluated, and the S/N of the lli degree signal 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 permissible limit, but edge noise and overall image quality are within the permissible range. Both image quality is unacceptable, and the luminance signal S/N is 3 dB to 4 compared to that of the first embodiment.
It has gotten worse by about dB.

Furthermore, when the sliding surfaces of these magnetic heads were observed under a microscope after the experiment, it was found that the sliding surfaces of the magnetic heads of the first example recovered to a nearly clean state, but the residual abnormal deposits were observed in the magnetic heads of the comparative example.

The reason for this is that there are six magnetic tape sections 16 and a leader tape 15.
A cleaning tape 41 for cleaning the sliding surface of the magnetic head is provided between the magnetic tape parts 16 and 16, so that it is thick enough to remove abnormal deposits that cannot be removed by a normal magnetic tape part 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.
fa, and between the end of the trailer tape 14 and the end of the ordinary magnetic tape section 16.

In the third embodiment shown in FIG. 3, a cleaning tape section 41 is provided between the end of the trailer tape 14 and the end of the ordinary magnetic tape section 16.

In the fourth embodiment shown in FIG. 4, a cleaning tape section 41 is provided approximately at the center of a normal magnetic tape section 16 so as to divide the 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.

The basic functions and effects of these components are substantially the same as those of the first embodiment, so their explanations will be omitted. Since the leader tape 15 is located between the tape portion 16 or approximately in the center of the ordinary tape portion 16, the leader tape 15
The light rays 32 and 33 passing through the trailer tape 14 are received by the light receiving elements 25 and 26 to detect the end of the tape, and even when used in conventional video tape recorders, etc., there will be no problems. In addition to maintaining compatibility, since the tape end detection mechanism does not operate in the cleaning tape section 41, the cleaning tape section can be reliably run along the drum and the sliding surface of the magnetic head can be cleaned, so that it is always good. Recording and playback can be performed in the same state. - (Effects of the Invention) As described above, the magnetic tape cassette of the present invention includes a magnetic tape section consisting of a transparent tape section and a magnetic layer, and a cleaning tape section for cleaning the sliding surface of the magnetic head section. Since the magnetic tape is housed in a cassette case, during use, the cleaning tape part and the sliding surface of the magnetic head perform relative sliding movement, resulting in abnormal deposits adhering to the sliding surface of the magnetic head. The wiped magnetic head is able to maintain a clean sliding surface at all times, preventing clogging and therefore eliminating the need to prepare a separate cleaning tape, allowing you to always enjoy good images. have

[Brief explanation of the drawing]

Figure 1 shows the magnetic tape force set 1 of the first embodiment of the present invention.
Figures 2 to 5 are explanatory diagrams for explaining the configuration of the magnetic tape built in the magnetic tape cassettes of the second to fifth embodiments, respectively. Explanatory drawing, Fig. 6 (a) is a perspective view of a magnetic tape cassette used in a VTR, Fig. 6 (b'I is the same figure (a)
FIG. 7 is a plan view showing the lower half of the magnetic tape cassette shown in FIG. 11...Cassette case, 12.13...Reel,
14...Transparent trailer tape, 15...Transparent leader tape, 16...Ordinary magnetic tape (second magnetic tape section), 40.50.60.70.80...Magnetic tape cassette, 41 ...Cleaning tape. T old; J Yu =

Claims (3)

[Claims] (1) A magnetic tape comprising a transparent tape section, a magnetic tape section consisting of a magnetic layer, and a cleaning tape section for cleaning the sliding surface of the magnetic head is housed in a cassette case. magnetic tape cassette. (2) Claim 1, characterized in that the cleaning tape section is provided at at least one end of the magnetic tape section.
Magnetic tape cassette described in section. (3) The magnetic tape cassette according to claim 1 or 2, wherein the cleaning tape portion has a transmittance of 2% or less for light having a wavelength of 9000 Å.