JPH0142816Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention is a tape cassette used for example in VTRs, tape recorders, and other various magnetic recording and reproducing devices. This invention relates to a tape cassette that can be identified by color-coding the tape.

As a conventional example 1 (Japanese Utility Model Application Publication No. 128503/1983) regarding the leader tape of this kind of tape cassette,
A leader tape is disclosed in which a soft synthetic resin film base is polymerized on both sides of a conductive metal.
In this leader tape, a metal foil for detecting the end of the tape by a magnetic detection method is protected with a film base to prevent the metal foil from being bent or wrinkled.

Conventional Example 2 (Japanese Utility Model Publication No. 51-63705) and Conventional Example 3 (Japanese Utility Model Application Publication No. 51-77115) disclose leader tapes having a transparent portion and a colored portion. In this leader tape, the end of the tape is detected by an optical detection method in the transparent part, and the type of magnetic tape, such as length and characteristics, can be identified in the colored part.

However, in Conventional Example 1, it is completely impossible to identify the type of magnetic tape, such as length or characteristics. In addition, in Conventional Examples 2 and 3, due to the tightening action of the magnetic tape wound around the outer periphery of the reel, the colored parts were directly and strongly rubbed against each other on the front and back sides.
When the colored portion comes into direct sliding contact with another object during tape running, etc., the colored portion is likely to peel off in a short period of time, causing discoloration. If discoloration occurs in the colored part, not only will it be difficult to identify the length, characteristics, etc. of the magnetic tape, but the discolored colored powder will adhere to the magnetic head, causing dropouts during recording and playback. This will cause serious adverse effects.

The present invention was devised to correct the above-mentioned defects, and it is a tape cassette in which a leader tape having a structure in which two soft synthetic resin film bases are laminated on both sides of a metal foil is connected to both ends of a magnetic tape. The above-mentioned flexible synthetic resin film base is formed of a film base formed so as to be transparent, and a colored layer is provided by printing or the like on the metal foil surface or the laminated surface of the above-mentioned film base, so that the colored layer is It is constructed so that it is covered with a film base.

Since the present invention is constructed in this manner, the soft synthetic resin film base formed so as to be transparent constitutes a protection means that protects both the metal foil and the colored layer at the same time.

An embodiment in which the present invention is applied to a tape cassette for a VTR will be described below with reference to the drawings.

As is conventionally known, a VTR tape cassette 1 is a cassette housing constructed by fitting an upper half 2 and a lower half 3 molded from synthetic resin into each other from above and below and securing them with screws, as shown in FIG. 4, and a substantially U-shaped lid 6 rotatably attached to the front opening 5 of the cassette housing 4 to open and close it.
It is composed of. A bottom opening 7 is formed on the front end side of the bottom of the cassette housing 4 and is connected to the front opening 5. A pair of tape reels 8 and 9 are rotatably housed in the tape cassette 1, and a magnetic tape 10 has a pair of leader tapes 11 and 12 connected to both ends thereof as shown in FIG. Through these tape reels 8,
9 and is stored wrapped.

As is conventionally known, a plurality of tape guides 13, 14, etc. are provided in the tape cassette 1 at positions on both left and right sides of the front end of the tape cassette 1.
is guided by these tape guides 13 and 14 and is initially stretched across both openings 5 and 7 in the left-right direction along the inner surface of the lid 6 within the tape cassette 1 as shown by the chain line in FIG. has been done.

Then, as is conventionally known, the tape cassette 1 is
When it is attached to the VTR main body, the lid 6 is opened as shown in FIG. The magnetic tape 10 is then pulled out of the tape cassette 1 from the front opening 5 as shown by the solid line in FIG. 1, and loaded onto a predetermined tape running path.

A pair of leader tapes 11 and 12 fixed to both ends of the magnetic tape 10 have a structure as shown in FIG.

That is, polyester film bases 16a and 16b, which are examples of soft synthetic resin film bases and can be seen through (transparent or translucent), are laminated (laminated) in a sandwich pattern on both sides of aluminum foil 15, which is an example of conductive metal foil. The aluminum foil 15 and the polyester film base 16 are coated with colored layers 17a and 17b for color-coding to identify the structure, length, characteristics, etc. of the magnetic tape 10.
The structure is formed by printing or the like on either one of the mutually laminated surfaces of a and 16b.

In this case, as shown in FIG.
A method of printing colored layers 17a, 17b on the sides 6a', 16b', and a method of printing colored layers 17a, 17b on the laminated surfaces 15a', 15b' of the aluminum foil 15 as shown in FIG.
There are two methods: printing etc.

According to the leader tapes 11 and 12 having the above structure, flexibility and restorability are very high, and these leader tapes 11 and 12 are not easily bent or wrinkled. In addition, both surfaces of the aluminum foil 15 are coated with both polyester film bases 1.
6a and 16b, the corrosion resistance of this aluminum foil 15 is extremely high.

Furthermore, the printing of the colored layers 17a and 17b is extremely simple, and the productivity is extremely high. Furthermore, since the surfaces of the colored layers 17a and 17b are covered with both polyester film bases 16a and 16b, the colored layers 17a and 17b may come into direct contact with other objects and peel off when the tape is running. There is no such thing, and the colored layers 17a, 1
7b is fully protected and extremely durable.

Normally, when the magnetic tape 10 is completely wound up on one of the tape reels 8 and 9, either the leader tape 11 or 12 is exposed through the front opening 5 of the tape cassette 1. Exposed leader tape 11 or 12
By distinguishing the colors of the colored layers 17a, 17b through the polyester film bases 16a, 16b, the length, characteristics, etc. of the magnetic tape 10 can be determined.

Note that, in relation to the ease of manufacturing the tape cassette 1 (particularly the incorporation of the magnetic tape into the cassette housing), in the above embodiment, the colored layers 17a and 17b were printed on both sides of the aluminum foil 15. Essentially, when the magnetic tape 10 is assembled in the cassette housing 4, it is sufficient that the colored layer 17a or 17b is provided only on one of the outer surfaces of the leader tapes 11 and 12. Further, the aluminum foil 15 can be changed to, for example, copper foil or other various conductive metal foils, and both polyester film bases 16a and 16b can also be changed to, for example, polyamide film, polyimide film, acetate film, or various other synthetic resin film bases. It is possible.

Next, FIGS. 6 and 7 show tape end detection during recording or playback by a VTR using a resonant circuit (parallel resonant circuit) consisting of a coil 19 and a capacitor 20.
A method using the inductance change of No. 21 is explained. In the figure, 22 is an oscillation circuit connected to the input end of the resonant circuit 21, and always supplies a predetermined frequency signal to the resonant circuit 21. 23 is a detection circuit connected to the output end of the resonant circuit 21. Further, 24 is a shut-off mechanism that controls the tape drive system based on the output from the detection circuit 23 and the like. Also, 26 is a rotating head drum, 2
7 is a tape loading pin, 28 is a capstan, 29 is a pinch roller, 30 is a group of tape guide pins, and the magnetic tape 10 is loaded onto a tape running path constituted by these members.
It is then run at a predetermined speed to perform desired recording or playback, fast forwarding, or rewinding.

Normally, when the frequency signal applied from the oscillation circuit 22 to the resonance circuit 21 passes through the coil 19, a predetermined amperage is generated in the coil 19 portion.
Magnetic lines of force are generated in response to turns.

During normal tape running, the magnetic tape 10 runs close to the coil 19, and the S
The magnetic permeability from the pole to the north pole remains constant, and a signal of a predetermined frequency, for example, is output to the detection circuit 23. In this state, the detection circuit 23, for example,
Retains OFF state.

When the tape ends during recording or playback or fast forwarding, and the leader tape 11 at the end of the magnetic tape 10 approaches the coil 19 of the resonant circuit 21 on the supply reel 8 side, the aluminum foil 15 causes the magnetic field lines of the coil 9 to The magnetic permeability of is rapidly increased. As a result, the inductance of the coil 19 changes rapidly, the resonance point of the resonant circuit 21 constituted by the coil 19 and the capacitor 20 changes, and the frequency signal supplied from the oscillation circuit 22 to the detection circuit 23 changes. For example, it is attenuated and this detection circuit 23 is switched to an ON state, for example. This operation performs a tape end detection operation, and from then on, at the above-mentioned moment, a control signal is supplied from the detection circuit 23 to the shut-off mechanism 24, and this shut-off mechanism 24 is activated.
is operated, the drive system for the magnetic tape 10 is momentarily stopped, and the running of the magnetic tape 10 is stopped.

When the tape end is reached during rewinding, the leader tape 12 at the leading end of the magnetic tape 10 approaches the coil 19 of the resonant circuit 21 on the take-up reel 9 side, and the same tape end detection and shut-off operation as described above is performed. .

According to the above-described method of detecting the tape end using the inductance change of the resonant circuit 21, there is no need to expose the conductive metal foils such as the aluminum foil 15 of the leader tapes 11 and 12 to the outside.

In the practical example described above, the present invention was applied to a tape cassette for a VTR, but the present invention is not limited to this, but can also be applied to tape cassettes for tape recorders and other various magnetic recording and reproducing devices. For example, in the case of a compact cassette for a tape recorder, a pair of leader tapes are secured to a pair of reel hubs and wound.

As mentioned above, in the present invention, the transparent soft synthetic resin film base constitutes a protective means that protects both the metal foil and the colored layer at the same time, so that the metal foil does not bend or wrinkle. It is a material that can prevent fading of the colored layer to identify the type of magnetic tape such as length and characteristics (strong rubbing due to tight winding of magnetic tape and tape running). It is possible to prevent the discoloration caused by peeling off due to direct sliding with other objects at times. Therefore, the colored layer, which does not fade, makes it possible to reliably identify the length, characteristics, etc. of the magnetic tape over a long period of time, and prevents colored powder from adhering to the magnetic head due to discoloration of the colored layer. Therefore, there is no serious adverse effect such as causing dropout during recording or playback.

[Brief explanation of the drawing]

The drawings show an embodiment in which the present invention is applied to a leader tape of a tape cassette for a VTR. Fig. 1 is a perspective view of the tape cassette, and Fig. 2 is a perspective view showing the relationship between the magnetic tape and the leader tape. 3 is an enlarged sectional view of the leader tape, FIGS. 4 and 5 are exploded perspective views of the leader tape illustrating the printed surface of the colored layer, and FIG. 6 is a loading state of the tape. The plan view and FIG. 7 are block diagrams illustrating the tape end detection circuit. In addition, in the symbols used in the drawings, 1... tape cassette, 4... cassette housing, 5... front opening, 8, 9... tape reel, 10... magnetic tape, 11, 12... leader tape, 15... ……
Aluminum foil, 15a', 15b'... Laminated surface of aluminum foil, 16a, 16b... Polyester film base, 16a', 16b'... Laminated surface of polyester film base, 17a, 17b... Colored layer. It is.

Claims (1)

[Claims for Utility Model Registration] In a tape cassette in which a leader tape having a structure in which two soft synthetic resin film bases are laminated on both sides of a metal foil is connected to both ends of a magnetic tape, A tape cassette characterized in that a colored layer is provided on the laminated side with the metal foil surface, and the film base is made of the above-mentioned soft synthetic resin so that the above-mentioned colored layer can be visually observed through the above-mentioned film base.