JPH0351830Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Industrial Application) The present invention relates to tape cassettes, and is particularly applicable to magnetic tape cassette recording and reproducing devices to which standard tape cassettes for general household use are applied. This invention relates to a tape cassette erroneous mounting prevention means which prevents the device from operating even if a tape cassette (special tape cassette) is erroneously mounted.

(Prior Art) Generally, there are two types of video tape recorders (hereinafter referred to as VTRs): general home VTRs and commercial VTRs.
Since the requirements for high image quality and quality are more stringent than those for VTRs, the recording method is naturally different from that for home use.

For example, the recording method of this type of professional VTR is β
There are two methods called the Cam (registered trademark) method and the M format method. For example, when recording signals using a standard type tape cassette of the former method, the luminance signal and color signal are recorded at a predetermined azimuth angle. In this method, each track is recorded alternately through guard bands using a magnetic head having a magnetic head.

The latter method, called the M format method, uses a standard VHS (registered trademark) tape cassette to alternately record luminance signals and color signals via a guard band. It is. Both of these types are VTRs for general home use.
This is different from the guard bandless recording method in which a luminance signal and a color signal are superimposed on each track and a magnetic head having a predetermined azimuth angle is used.

Therefore, for example, tape cassettes on which signals are recorded using the above two recording formats for business use are not suitable for general household use because their external shapes are the same.
It is easy to be mistaken for a tape cassette used in a VTR (hereinafter sometimes referred to as a standard VTR), and when it is installed in a standard VTR, the recording format and signal playback processing system are different, as mentioned above. Naturally, this results in various inconvenient situations, such as making it impossible to play back previously recorded signals and making the user think that the device (VTR) is broken and creating a sense of distrust.

In addition, as the image quality and quality have become higher, magnetic tape materials have changed from those whose main components are Fe ₂ O ₃ and CrO ₂ to tapes that use metal materials, and the former material is now being used. Ferrite heads are generally used for magnetic tape recording/reproducing heads, and tape recording/reproducing heads using the latter material are made of materials such as sendust and , an amorphous head, which has been in the spotlight in recent years, is used. Therefore, if a tape cassette that uses metal tape is attached to a standard VTR that uses a ferrite head for recording, the saturation magnetic flux density will be insufficient due to the composition of the ferrite head, and the signal will not be recorded properly. The problem arises that this is not possible.

Generally, this type of tape cassette consists of an upper half and a lower half that are divided into two halves, the lids of which are joined together with screws, etc., and the magnetic tape is wound inside the tape cassette. A supply reel and a take-up reel are rotatably housed at predetermined positions in the cassette body with a predetermined interval between them. And when recording/playing,
The opening/closing lid provided on one side of the case body is a VTR.
The cassette is opened by a lid opening mechanism, and the magnetic tape is pulled out from the cassette body by a magnetic tape pull-out means and brought into contact with a magnetic head.

Here, a standard tape cassette used in a conventional standard VTR will be explained. FIG. 4 is a sectional view showing how a conventional standard tape cassette is attached to a standard VTR.

In the figure, tape cassette 1 is connected to upper half 2.
A take-up side tape reel and a supply side tape reel 4, 4 are rotatably housed (built-in) in a cassette housing consisting of a lower half 3 and a magnetic tape 5 (on at least one of them). It is wrapped.

Further, two openings 6, 6 are provided in the lower half 3 of the tape cassette 1, and through these openings 6, 6, reel drive shafts 7, 7 on the winding side and the supply side of the VTR are connected to the respective tape reels 4. , 4. Further, a leaf spring 8 is provided on the inner surface of the upper half 4 of the tape cassette 1, and the left and right tips of the leaf spring 8 move the respective tape reels 4, 4 (the protrusion at the top of the center) in the direction of arrow A in the figure. It is energizing.

FIG. 5a shows a sectional view of the tape reel 4, and FIG. 5b shows a bottom view of the tape reel 4.

The tape reel 4 has an upper flange 9 and a lower flange 1.
0, and the reel hub 11 is attached to the lower flange 10.
are integrally formed. Further, this reel hub 11 has a reel shaft insertion hole 12 in its center,
A total of nine protrusions 13 are formed on the inner wall. Furthermore, in addition to this, there is a protrusion 14 formed integrally with the reel hub 11 at the top of the center of the tape reel 4.
protrudes, and comes into contact with the left and right tips of the leaf spring 8 provided on the upper half 2 after the tape cassette 1 is assembled.

Figure 6a shows a side view of the reel drive shaft;
Figure b shows a top view of the reel drive shaft.

The reel drive shaft 7 includes a reel disk 16 that is rotatable with respect to a fixed shaft 15 (shown in the fourth figure) mounted on a VTR base (not shown), and a reel shaft 17 that is integrally formed with the disk 16. has. Further, the reel shaft 17 is provided with a reel feather 18 that is fitted and rotated integrally with the reel shaft 17 and is also movable up and down. The reel feather 18 has three ribs 19 on its outer periphery, is biased upward by a compression coil spring 20, and comes into contact with the lower surface of the head 2 of the reel shaft 17 to restrict its upward movement position. There is.

As described above, in the standard tape cassette 1 for a standard VTR, the number of protrusions 13 provided on the tape reel 4 is nine, and on the other hand, the number of protrusions 13 provided on the tape reel 4 is nine.
Since there are three ribs 19 provided in the
Since the number of protrusions 13, 9, is an integral multiple of the number of protrusions 13, 3, it is possible for both of these to mesh.

Therefore, when attempting to mount this standard tape cassette 1 on a standard VTR, the tape cassette 1 is pushed down with the respective tape reels 4, 4 facing the pair of reel drive shafts 7, 7 on the standard VTR side. , the tape cassette 1 is properly loaded into the VTR in the state shown in FIG. That is, in this state, the head 21 of the reel shaft 17 is inserted into the insertion hole 12 of the reel hub 11, and the rib 19 of the reel shaft 17 and the protrusion 13 on the inner wall of the insertion hole 12 are engaged.

Further, since the lower surface of the reel hub 11 comes into contact with the upper surface of the reel disk 16, the tape reel 4 is floating in the direction of arrow B in the figure against the pressing force of the leaf spring 8, and both tape reels 4, 4 upper half 2
It is held at the center position in the vertical direction so that it does not come into contact with any of the lower half 3 and the lower half 3.

Furthermore, in the state shown in the fourth figure, the actuator 23 of the switch 22 provided on the VTR base (not shown)
Since the lower surface (lower half surface) of the tape cassette 1 presses the tape cassette 1, this switch 22 is activated, and a cassette loading completion signal from this switch 22 causes operations such as tape loading and tape running drive to be performed via the control circuit. It will be in a standby state to move.

(Problems to be solved by the invention) By the way, as mentioned above, in addition to standard VTRs for general home use, special purpose VTRs have recently appeared.

That is, for example, special VTRs called β-cam (registered trademark) system or M-format system used for commercial purposes such as news reports use tape cassettes for standard VTRs, but have a different recording method, and also have a tape running speed. Since the specifications are different, they are not compatible with standard VTRs at all (because the standards are different).

In addition, in terms of the material of the magnetic tape,
When metal tapes, vapor-deposited tapes, etc. are used for high-density recording, they are not compatible because the recording current and erasing current are different.

Therefore, it has been strongly desired to provide a tape cassette with a means for preventing a tape cassette recorded with such a special purpose VTR from being installed in a general standard VTR.

Note that the tape cassettes of these special VTRs also use standard cassettes for the cassette housing and tape protection lid, so even though they are special cassettes, their external dimensions and shape are almost standard. They are the same as the type, and if they were differentiated by mere markings, it would cause confusion during use, and there was a risk of arousing distrust among users.

Therefore, the present invention has been developed so that even if a tape cassette other than the standard type tape cassette mentioned above (special tape cassette) is inserted (inserted) into the cassette insertion slot of a standard type VTR by mistake, it will not be installed properly. The reel drive shaft on the VTR side is not inserted into the insertion hole of the cassette reel to the specified position, and therefore the tape cassette is prevented from moving at a position in the middle of being attached to the VTR, and subsequent operations such as tape loading and tape running drive etc. An object of the present invention is to provide a tape cassette which prevents this from occurring.

(Means for Solving the Problems) In order to achieve the above object, the present invention rotatably stores a tape reel 26 on which magnetic tape 5 is wound in the cassette casings 2 and 3. In the tape cassette 25, the reel shaft insertion hole 29 of the tape reel 26 is configured to engage the reel drive shaft 32 of a magnetic tape cassette recording/reproducing device to rotationally drive the tape reel 26. The number of protrusions 30 formed on the inner wall of the tape cassette 29 is different from the number of protrusions 13 formed on the inner wall of the reel shaft insertion hole 12 of the tape reel 4 of the standard tape cassette 1, and To provide a tape cassette characterized in that the number of ribs 19 provided on the reel feather 18 of the reel drive shaft 7 of a standard type magnetic tape cassette recording and reproducing device used with a magnetic tape cassette mounted thereon is set to a number that is not an integral multiple of the number of ribs 19. be.

(Function) In the tape cassette configured as described above, the reel drive shaft is provided with a number of ribs corresponding to the number of protrusions 30 formed on the inner wall of the reel shaft insertion hole 29 of the tape reel 26 of this tape cassette. This feature is only available when attached to a VCR equipped with
VTR operation becomes possible.

As a result, the recording mode based on the signal recording method of one VTR always matches the signal recording mode on the magnetic tape housed in the tape cassette loaded in this VTR.

(Embodiment) An embodiment of the tape cassette according to the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a state in which a tape cassette other than the standard type tape cassette (special tape cassette), which is an embodiment of the tape cassette according to the present invention, is incompletely attached to a standard type VTR. Note that the following description is the same as that of the standard tape cassette (shown in the fourth figure) except as otherwise specified.

In the figure, a tape cassette 25 has tape reels 26, 26 on the take-up side and the supply side rotatably stored (built-in) in a cassette housing consisting of an upper half 2 and a lower half 3. A magnetic tape 5 is wound (at least on one side).

Further, the lower half 3 of the tape cassette 1 is provided with two openings 6, 6, through which the reel drive shafts on the take-up side and the supply side of the VTR connect to the respective tape reels 26, 26. It's starting to engage.

Furthermore, the tape reels 26, 26 are rotated by a leaf spring 8 provided on the inner surface of the upper half 2 of the tape cassette 1.
is biased in the direction of arrow A in the figure.

FIG. 2a shows a cross-sectional view of the tape reel 26,
FIG. 2b shows a bottom view of the tape reel 26. FIG.

The tape reel 26 consists of an upper flange 9 and a lower flange 27, and a reel hub 28 is integrally formed on the lower flange 27. Further, the reel hub 28 has a reel shaft insertion hole 29 at its center, and a total of eight protrusions 30 are formed on the inner wall of the reel shaft insertion hole 29.

In addition, the top of the center of the tape reel 26 has a protrusion 31 similar to the standard tape cassette, and the left and right tips of the leaf springs 8 provided on the inner surface of the upper half 2 of the tape cassette 25 are attached to the protrusion 31. The tape reel 26 is urged in the direction of arrow A in the figure.

FIG. 3a shows a side view of the reel drive shaft for the above-mentioned special tape cassette (tape cassette of the present invention), and FIG. 3b shows a top view of the reel drive shaft.

The reel drive shaft 32 for the special tape cassette according to the present invention is a reel disk 16 that is rotatable about a fixed shaft installed on a VTR base (not shown).
and a reel shaft 17 formed integrally with this reel disk 16. Further, the reel shaft 17 is provided with a reel feather 33 that is fitted and rotated integrally with the reel shaft 17 and is also movable up and down. Four ribs 34 are formed on the outer periphery of this reel feather 33.

Further, the reel feather 33 is urged upward by the relatively weak compression coil spring 20, and the reel feather 33 is urged upward by the relatively weak compression coil spring 20,
The upward movement is regulated by the head 21 of 7.

As described above, in the special tape cassette 25 for a special VTR according to the present invention, the number of protrusions 30 provided on the tape reel 26 is eight;
Reel feather 33 of reel drive shaft 32 for VTR
Since there are 4 ribs 34, the number 8 of the protrusions 30 is an integral multiple of the number 4 of the ribs 34, so
Both of these meshes are possible.

However, if the tape cassette 25, which is the above-mentioned special tape cassette, is mistakenly attached to a standard VTR, the reel feather 18 of the reel drive shaft 7 of the standard VTR (see Figures 6a and 6b) Since the number of ribs 19 (3) and the number (8) of protrusions 30 in the reel shaft insertion hole 29 of the tape cassette 25, which is a special tape cassette, is not an integral multiple, the two do not mesh with each other.

Therefore, when the tape cassette 25, which is a special tape cassette, is pushed down in the direction of arrow A as shown in FIG. 20 in the same direction.

Note that since the coil spring 20 has a relatively small biasing force, the tape reel 26
The projection 31 at the top of the center is pressed by the leaf spring 8, and the lower surface of the reel hub 28 comes into contact with the upper surface of the reel disk 6.

In other words, the tape cassette 25 is a standard VTR.
This means that the VTR is installed in its normal position, but even if you perform recording or playback operations on the VTR in this state, the reel feather 18 of a standard VTR will not work.
Since the rib 19 of the tape cassette 25, which is a special tape cassette, and the protrusion 30 of the reel shaft insertion hole 29 of the tape cassette 25 do not mesh with each other, one reel drive shaft 7 (drive side) of the standard VTR only rotates idly, and the tape reel 26 does not rotate.

As a result, a reel shaft rotation detection device (not shown) provided on the other reel drive shaft 7 (driven side) is activated, and the VTR is automatically stopped. Furthermore, at this time,
Generates an eject signal in the control circuit to control the VTR.
The tape cassette 25 once installed (inserted) in
It is also possible to configure it so that it is automatically discharged outside the VCR (outside the machine).

As described above, a tape cassette according to an embodiment of the present invention, that is, a special VTR for commercial use, which has the same external shape as a standard tape cassette, but has a recording method different from that of the standard tape cassette.
The number of protrusions provided on the inner wall of the reel shaft insertion hole of the tape reel is as follows:
Foreign species that should be prohibited from operating this tape cassette
By setting the number of ribs to a number that is not an integral multiple of the number of ribs on the reel drive shaft of a VTR (for example, a standard VTR), the operation of this tape cassette should be prohibited. It is possible to make it impossible to transmit the driving force of this tape cassette to the tape reel, and to prevent malfunctions such as accidentally using this tape cassette in a different type of VTR such as a standard VTR. This can be prevented and, therefore, the user will not feel distrustful.

Furthermore, the tape cassette of one embodiment of the present invention differs from the standard tape cassette only in the tape reel, and other cassette housing parts, tape protection lids, etc. are the same as those of the standard tape cassette. Therefore, the cost of molds and the like required for manufacturing this tape cassette is small, and the manufacturing cost can be reduced.

(Effects of the Invention) As described above, the tape cassette of the present invention has the number of protrusions 30 formed on the inner wall of the reel shaft insertion hole of the tape reel to be smaller than the number of protrusions 30 formed on the inner wall of the reel shaft insertion hole of the tape reel 4 of the standard tape cassette 1. The number of ribs 19 is different from the number of protrusions 13 formed on the inner wall of the magnetic tape cassette, and the ribs 19 are provided on the reel feather 18 of the reel drive shaft 7 of the standard type magnetic tape cassette recording and reproducing apparatus which is used with the standard type tape cassette 1 installed. A tape that stores magnetic tapes on which signals are recorded in a manner different from the recording manner based on the signal recording method executed (playback operation, etc.) by the magnetic tape cassette recording and reproducing device by setting the number to a number that is not an integral multiple of the number of tapes. It has features such as being able to prevent the cassette from being erroneously mounted (erroneously inserted) into the recording/reproducing apparatus.

Further, according to the present invention, the above-mentioned effects can be achieved with a tape cassette having external dimensions approximately equal to those of conventional tape cassettes.

[Brief explanation of the drawing]

Fig. 1 is a sectional view of a tape cassette other than the standard tape cassette, which is an embodiment of the tape cassette of the present invention, showing a state in which it is incompletely installed in a standard VTR, and Fig. 2a and b are the tape cassettes of the present invention. A side view and a bottom view showing a tape reel constituting an embodiment of the tape cassette, FIGS. 3a and 3b.
4 is a side view and a top view showing the reel drive shaft of a special VTR using one embodiment of the tape cassette of the present invention, and FIG.
5a and 5b are side and bottom views showing the tape reel constituting a conventional tape cassette, and FIGS. 6a and 6b are the reels of a standard VTR. It is a side view and a top view which show a drive shaft. 2... Upper half, 3... Lower half, 5... Magnetic tape, 1, 25... Tape cassette, 18, 3
3... Reel Fueza, 19, 34... Rib, 26
...Tape reel, 29...Reel shaft insertion hole, 3
0... Projection, 7, 32... Reel drive shaft.

Claims (1)

[Scope of Claim for Utility Model Registration] A tape reel 26 on which magnetic tape 5 is wound is rotatably housed in the cassette casings 2 and 3, and a magnetic tape cassette recording and reproducing device is inserted into the reel shaft insertion hole 29 of the tape reel 26. The reel drive shaft 32 of the tape reel 26 is engaged with the protrusion 30 formed on the inner wall of the reel shaft insertion hole 29 and the rib 34 provided on the reel feather 33 of the reel drive shaft 32. In the tape cassette 25 configured to be rotationally driven, the reel shaft insertion hole 2 of the tape reel 26
The number of protrusions 30 formed on the inner wall of the tape cassette 9 is different from the number of protrusions 13 formed on the inner wall of the reel shaft insertion hole 12 of the tape reel 4 of the standard tape cassette 1, and A tape cassette characterized in that the number of ribs 19 provided on a reel feather 18 of a reel drive shaft 7 of a standard type magnetic tape cassette recording and reproducing device used by mounting a tape cassette is set to a number that is not an integral multiple of the number of ribs 19.