JPH0817165A - Tape cassette - Google Patents

Abstract

PURPOSE:To prevent a special type tape cassette from being loaded onto a standard magnetic recording/reproducing apparatus for a standard tape cassette. CONSTITUTION:When a magnetic tape 48 wound on a pair of tape reels 41 and 41 is housed in the cassette housing 3 of a tape cassette 40 so as to rotate freely, the outside shape of the cassette housing 3 is formed so as to be approximately the same as the shape of a standard tape cassette and, further, the depth of the reel shaft insertion hole 44 of the tape reel 41 is designed to be approximately the same as the depth of the hole of the standard tape cassette. Further, a protrusion 47 is provided at the center of the top plane inside the reel shaft insertion hole 44 of the tape cassette 40. The protrusion 47 touches the tip of the center part of a reel driving shaft 7 on the side of a standard magnetic recording/reproducing apparatus onto which a standard tape cassette can be loaded and hence the tape cassette is loaded onto the apparatus incompletely.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette (high-density tape cassette) formed in substantially the same shape as, for example, a standard tape cassette compliant with the VHS standard. Type magnetic recording / reproducing apparatus.

[0002]

2. Description of the Related Art Recently, a magnetic tape housed in a tape cassette is required to record and reproduce HDTV images such as high-definition images and landscape screen TV images with high density and high image quality. Further, at the present stage where digital recording / reproduction is possible on a magnetic tape, a high-density type tape cassette and a high-density type magnetic recording / reproducing apparatus corresponding thereto are demanded.

On the other hand, a standard type magnetic recording / reproducing apparatus to which a standard type tape cassette compliant with the VHS standard can be mounted, for example, has already been widely used in the world, and along with this, a large amount of standard type tape cassettes have been produced. Standard tape cassettes are available at low cost.

Therefore, in developing the above-mentioned high-density tape cassette, if the outer shape of the cassette housing is formed to be substantially the same as that of the standard tape cassette, not only the mold of the cassette housing can be shared but also the tape cassette Since the automatic assembling equipment can be shared, it is possible to provide the high-density tape cassette at a low cost.

However, if the outer shape of the high-density tape cassette is formed to be substantially the same as that of the standard-type tape cassette, the high-density tape cassette can be installed in the standard-type magnetic recording / reproducing apparatus. The magnetic tape of this type not only has different recording / playback performance from the magnetic tape in the standard type tape cassette, but also has a different recording / playback format. appear. In order to solve this problem, a special tape cassette equipped with almost the same technical idea is used.
No. 3 publication.

First, a standard tape cassette and a standard magnetic recording / reproducing apparatus adopting, for example, the VHS standard will be described with reference to FIGS.

FIG. 5 is a sectional view showing a state in which a conventional standard tape cassette compliant with the VHS standard is completely mounted in a standard magnetic recording / reproducing apparatus, and FIGS. 6A and 6B are conventional standard tapes. 7A and 7B are a side view and a top view for explaining the reel drive shaft on the standard type magnetic recording / reproducing apparatus side.

As shown in FIG. 5, the standard type tape cassette 1 has a pair of tape reels 4 and 4 in a cassette housing 3 assembled by capping an upper half 2U and a lower half 2L.
Rotatably accommodates a pair of tape reels 4, 4
A magnetic tape 5 is wound around. Also, the lower half 2
A pair of round holes 6 and 6 are formed in L so as to face the pair of tape reels 4 and 4. Through the pair of round holes 6 and 6, the reel drive shaft 7 on the standard magnetic recording / reproducing apparatus side is formed. , 7
Engage with the respective tape reels 4, 4. Further, a leaf spring 8 is provided on the inner surface of the upper half 2U of the standard type tape cassette 1, and the left and right end portions of the leaf spring 8 urge the respective tape reels 4, 4 in the arrow Y ₁ direction. ing.

Further, as shown in FIGS. 6 (A) and 6 (B),
The tape reel 4 has an upper flange 9, a lower flange 10,
Reel hub 11 integrally formed in the center of the lower flange 10
It is formed in a "V" shape from. Further, the reel hub 11 has a reel shaft insertion hole 12 formed deeply from the lower surface at the center thereof, and a total of nine ridges 13 are formed on the inner wall of the reel shaft insertion hole 12. Further, a leaf spring contact portion 14 is formed on the upper center of the reel hub 11 so as to project upward. In addition, in FIG. 6 (A), the protrusion 13 is 2
Only the book is shown and the others are omitted.

Further, as shown in FIGS. 5 and 7A and 7B, the reel drive shaft 7 on the standard magnetic recording / reproducing apparatus side.
Is a reel disc 16 rotatable with respect to a fixed shaft 15 erected on a chassis base (not shown) and the reel shaft 1 integrally projecting upward from the reel disc 16.
Have 7. Further, the reel shaft 17 has the reel shaft 1
A reel feather 18 is provided which can be vertically moved while being fitted and rotated integrally with 7. The reel feather 18 has three ribs 19 on the outer circumference, is urged upward by the compression coil spring 20, and comes into contact with the lower surface of the head portion 21 attached to the upper end of the reel shaft 17 to move the upper position. It is regulated.

Therefore, when the standard tape cassette 1 is mounted on the standard magnetic recording / reproducing apparatus, the pair of tape reels 4 and 4 are opposed to the reel drive shafts 7 and 7, and the standard tape cassette 1 is pushed down. The standard type tape cassette 1 is completely (normally) mounted in the state shown in FIG.
That is, the head portion 21 attached to the top end of the reel shaft 17 is inserted into the reel insertion hole 12 from the lower surface of the reel hub 11, and the rib 19 of the reel shaft 17 and the reel insertion hole 12 are provided.
Surely meshes with the ridges 13 on the inner wall of the. Further, since the lower surface of the reel hub 11 abuts on the upper surface of the reel disk 16, the tape reel 4 floats in the direction of the arrow Y ₂ against the pressing force of the leaf spring 8 and the pair of tape reels 4, 4.
4 is held at the central position in the up-down direction that does not contact either the upper half 2U or the lower half 2L. In this state, the lower surface of the lower half 2L of the standard type tape cassette 1 is
Since the actuator 23 of the switch 22 provided on the side of the standard type magnetic recording / reproducing apparatus is pushed, the side of the standard type magnetic recording / reproducing apparatus determines that the standard type tape cassette 1 is completely (normally) mounted.

Next, the conventional special type tape cassette and special type magnetic recording / reproducing apparatus disclosed in Japanese Utility Model Publication No. 2-37193 will be described with reference to FIGS. 8 to 11.
For convenience of explanation, the standard tape cassette 1 shown above is used.
The same reference numerals will be given to the same constituent members as those in FIG.
Only the points different from the above will be described.

FIG. 8 is a sectional view showing a state in which the conventional special type tape cassette is imperfectly mounted on the standard type magnetic recording / reproducing apparatus, and FIGS. 9A and 9B are tapes of the conventional special type tape cassette. Sectional view and bottom view showing the reel, FIG.
(A) and (B) are side and top views for explaining the reel drive shaft on the special type magnetic recording / reproducing apparatus side, and FIG. 11 is a conventional special type tape cassette completely attached to the special type magnetic recording / reproducing apparatus. It is sectional drawing which showed the state.

In the special type tape cassette 25 shown in FIG. 8, the cassette housing 3 assembled by covering the upper half 2U and the lower half 2L together is the cassette housing 3 of the standard tape cassette 1 described above. The recording / reproducing format is adopted so that the magnetic tape 5 housed in the cassette housing 3 can be recorded / reproduced with high image quality and high quality for business use. Therefore,
The special-type tape cassette 25 cannot be recorded / reproduced by the standard-type magnetic recording / reproducing apparatus described above, but needs to be recordable / reproducible by the special-type magnetic recording / reproducing apparatus.

Therefore, as shown in FIGS. 9A and 9B, the tape reel 26 around which the magnetic tape 5 is wound is integrally formed at the center of the upper flange 9, the lower flange 27, and the lower flange 27. The reel hub 28 and the formed reel hub 28 are formed in an "E" shape. Further, the reel hub 28 has a reel shaft insertion hole 29 formed in the central portion of the reel hub 28 so as to have a shallow depth from the lower surface. That is, the reel shaft insertion hole 29 of the tape reel 26 accommodated in the special type tape cassette 25 is deeper than the reel shaft insertion hole 12 of the tape reel 4 accommodated in the standard type tape cassette 1 described in FIG. Is shallowly formed. Further, a total of nine ridges 30 are formed on the inner wall of the reel shaft insertion hole 29. Further, a leaf spring contact portion 32 is formed at the upper center of the reel hub 28 so as to project upward. Note that, in FIG.
Only the book is shown.

When the conventional special type tape cassette 25 having the above-mentioned structure is mounted on the standard type magnetic recording / reproducing apparatus, the reel driving shaft 7 on the standard type magnetic recording / reproducing apparatus side has a high height. The head portion 21 comes into contact with the top surface 31 of the reel shaft insertion hole 29 of the special type tape cassette 25. Therefore, attach the special type tape cassette 25 to the arrow Y ₁
Even if the tape reel 26 is pushed downward, the downward movement position of the tape reel 26 is regulated, and then the leaf spring contact portion 32 of the tape reel 26 passes through the leaf spring 8 and the special type tape cassette 25.
The downward movement of the special-type tape cassette 25 is restricted by contacting the back surface of the upper half 2U. That is, in this state, the lower surface of the lower half 2L of the special-type tape cassette 25 does not come into contact with the actuator 23 of the switch 22 provided on the standard-type magnetic recording / reproducing apparatus side, so that the switch 22 does not operate. As a result, the standard type magnetic recording / reproducing apparatus performs an operation such as notifying the user that the special type tape cassette 25 is incompletely mounted or forcibly ejecting the special type tape cassette 25. There is.

On the other hand, when the conventional special-type tape cassette 25 is mounted in the special-type magnetic recording / reproducing apparatus, FIG.
As shown in FIGS. 11A and 11B and FIG. 11, the reel drive shaft 33 on the special type magnetic recording / reproducing apparatus side is rotatable with respect to the fixed shaft 24 that is erected on a chassis base (not shown) or the like. It has a reel disc 34 and a reel shaft 35 integrally projecting upward from the reel disc 34. Also,
The reel shaft 35 is fitted and rotated integrally with the reel shaft 35, and can be vertically moved up and down while being reeled up and down 36.
It has. The reel feather 36 has three ribs 37 on its outer circumference, is biased upward by a compression coil spring 38, and comes into contact with the lower surface of a head portion 39 attached to the upper end of the reel shaft 35 to move the upper moving position. It is regulated.
Here, the heights of the fixed shaft 24 and the reel drive shaft 33 are reduced by the depth of the reel shaft insertion hole 29 of the special-type tape cassette 25. Therefore, as shown in FIG. 11, the special type tape cassette 25 can be completely (normally) attached to the special type magnetic recording / reproducing apparatus.

[0018]

By the way, as described above, the reel shaft insertion hole 29 of the tape reel 26 accommodated in the conventional special type tape cassette 25 is accommodated in the standard type tape cassette 1 described above. Since the tape reel 4 is formed to be shallower than the reel shaft insertion hole 12 of the tape reel 4, the special-type tape cassette 25 cannot be applied to the standard-type magnetic recording / reproducing apparatus, and can be applied to the special-type magnetic recording / reproducing apparatus. As shown in FIG. 11, when the special-type tape cassette 25 is mounted on the special-type magnetic recording / reproducing apparatus, since the reel shaft insertion hole 29 has a shallow depth, a total of nine reel shaft insertion holes 29 are formed on the inner wall of the reel shaft insertion hole 29. The amount of meshing between the ridge 30 and the three ribs 37 formed on the outer periphery of the reel feather 36 becomes small, and the meshing of the both 30, 37 is disengaged, and the tape reel 26 is There may not be rotated by the reel drive shaft 33 of Koto-type magnetic recording and reproducing apparatus, has become a problem.

Therefore, in developing a high-density tape cassette capable of high-density and high-quality digital recording / reproducing, the high-density tape cassette cannot be applied to a standard magnetic recording / reproducing apparatus, It is desired that the tape reel in the high-density tape cassette can be reliably rotated and driven by the reel drive shaft on the high-density magnetic recording / reproducing apparatus side while being applicable to the recording / reproducing apparatus.

[0020]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and rotatably stores a tape reel wound with a magnetic tape in a cassette housing, and a reel shaft insertion hole of the tape reel. In a tape cassette configured to engage the reel drive shaft of the magnetic recording / reproducing device to drive the tape reel to rotate, the outer shape of the cassette housing is formed to be substantially the same as that of a standard tape cassette, and The depth of the reel shaft insertion hole is set to be approximately the same as that of the standard type tape cassette, and a protrusion is provided at the center of the top surface in the reel shaft insertion hole, and the protrusion forms the standard type tape cassette. A tape cassette characterized in that the tape cassette is configured so as to be in an incompletely mounted state by abutting on the center end of the reel drive shaft on the side of the standard type magnetic recording / reproducing apparatus that can be mounted. It is intended to provide.

[0021]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the tape cassette according to the present invention will be described in detail below with reference to FIGS.

FIG. 1 is a sectional view showing a state in which the tape cassette according to the present invention is imperfectly mounted in a standard type magnetic recording / reproducing apparatus, and FIGS. 2A and 2B are tapes of the tape cassette according to the present invention. 3A to 3C are side views, a top view, a cross-sectional view and FIG. 4 showing a reel drive shaft on the side of the high-density magnetic recording / reproducing apparatus. FIG. 3 is a cross-sectional view showing a state in which the tape cassette according to the present invention is completely attached to a high-density magnetic recording / reproducing apparatus.
For convenience of explanation, the standard tape cassette 1 shown above is used.
The same reference numerals will be given to the same constituent members as those of (1) and (2) will be described.

In the tape cassette (hereinafter referred to as a high density type tape cassette) 40 according to the present invention shown in FIG.
The cassette housing 3 assembled by covering the upper half 2U and the lower half 2L with each other is formed to have substantially the same external dimensions as the cassette housing 3 of the standard tape cassette 1 described above. Magnetic tape 4 stored in body 3
A digital recording / reproducing format is adopted so that 8 can be recorded / reproduced with high density and high image quality. Therefore, the high-density tape cassette 40 cannot be recorded / reproduced by the standard magnetic recording / reproducing apparatus described above, but must be recorded / reproduced by the high-density magnetic recording / reproducing apparatus. .

Therefore, the pair of tape reels 41, 41 rotatably housed in the cassette housing 3 is shown in FIG.
As shown in (B), the upper flange 9 and the lower flange 4
2 and a reel hub 43 which is integrally formed in the center of the lower flange 42, are formed in an "E" shape. Further, the reel hub 43 has a reel shaft insertion hole 44 formed deeply from the lower surface at the center thereof, and the reel shaft insertion hole 4 is formed.
A total of nine ridges 45 are formed on the inner wall of No. 4. At this time, the reel shaft insertion hole 4 of the high-density tape cassette 40
The depth of 4 and the length of the ridge 45 are set to have substantially the same dimensions as the reel shaft insertion hole 12 and the ridge 13 of the standard tape cassette 1 described above with reference to FIG. 2A, only two ridges 45 are shown and the others are omitted.

A protrusion 47, which is an essential part of the present invention, hangs downward at the center of the top surface 46 in the reel shaft insertion hole 44 of the high-density tape cassette 40. The reason for providing the protrusion 47 is that the high-density tape cassette 40 is incompletely attached to the standard-type magnetic recording / reproducing apparatus as described later, while it is complete to the high-density-type magnetic recording / reproducing apparatus. It is provided to be mounted. Further, the leaf spring contact portion 4 is provided on the upper center of the reel hub 43.
8 is formed so as to project upward.

Returning to FIG. 1, the pair of tape reels 41, 41 housed in the cassette housing 3 are formed with a tape width of, for example, 1/2 inch, and a thin base film is made of a magnetic material such as chrome. A magnetic tape (metal tape) 48 on which a material is applied or vapor-deposited is wound, and the magnetic tape 48 has a recording / reproducing performance capable of recording / reproducing with high density and high image quality.

Further, the lower half 2L is provided with a pair of round holes 6, 6 facing the pair of tape reels 41, 41, and a high-density type described later through the pair of round holes 6, 6. Reel drive shafts 50, 50 (FIGS. 3, 4) on the magnetic recording / reproducing apparatus side are adapted to engage with the respective tape reels 41, 41. When the high-density tape cassette 40 is erroneously inserted into the standard magnetic recording / reproducing apparatus, the reel drive shafts 7, 7 on the side of the standard magnetic recording / reproducing apparatus are connected to the respective tape reels through the pair of round holes 6, 6. 41, 41 can be engaged. Further, a leaf spring 8 is provided on the inner surface of the upper half 2U of the high-density tape cassette 40, and the left and right end portions of the leaf spring 8 are respectively attached to the tape reels 41, 41.
Is urged in the direction of the arrow Y ₁ .

High-density tape cassette 4 having the above structure
When 0 is mounted on the standard type magnetic recording / reproducing apparatus, since the reel drive shaft 7 on the side of the standard type magnetic recording / reproducing apparatus is high, the central portion of the top surface 46 in the reel shaft insertion hole 44 of the tape reel 41. The protrusion 47 provided at the end abuts on the tip of the center of the head 21, which is the tip of the center of the reel drive shaft 7. Therefore, even if the high-density tape cassette 40 is pushed down in the direction of the arrow Y ₁ , the downward movement position of the tape reel 41 is restricted and it cannot move further downward. That is, in this state, the lower surface of the lower half 2L of the high-density tape cassette 40 has the switch 22 provided on the standard magnetic recording / reproducing apparatus side.
Since it does not contact the actuator 23 of the switch 22,
Does not work. As a result, the standard type magnetic recording / reproducing apparatus side informs the user that the high-density tape cassette 40 is incompletely mounted, or performs operations such as forcibly ejecting the high-density tape cassette 40. Since it does, the user immediately knows that the tape cassette was erroneously inserted.

On the other hand, when the high-density tape cassette 40 is mounted in the high-density magnetic recording / reproducing apparatus, FIG.
(C) and FIG. 4, the reel drive shaft 50 on the side of the high-density magnetic recording / reproducing apparatus is a reel disc that is rotatable with respect to a fixed shaft 49 that is erected on a chassis base (not shown) or the like. 51, and a reel shaft 52 integrally projecting upward from the reel disk 51. In addition, the reel shaft 52 is provided with a reel feather 53 which is fitted and rotated integrally with the reel shaft 52 and which is vertically movable. The reel feather 53 has three ribs 54 on the outer circumference, is biased upward by a compression coil spring 55, and is attached to the head 56 attached to the top end of the reel shaft 52.
The upper moving position is restricted by contacting the lower surface of the.

Here, the head 56 attached to the tip of the reel drive shaft 50 on the high-density magnetic recording / reproducing apparatus side corresponds to the protrusion 47 formed in the reel shaft insertion hole 44 of the high-density tape cassette 40. A concave portion 57 into which the protrusion 47 can be inserted is formed in the central portion of, and the height of the fixed shaft 49 erected in a chassis base (not shown) or the like is also set low due to the formation of the concave portion 57. .

However, the height of the reel drive shaft 50 on the side of the high density type magnetic recording / reproducing apparatus is set to be substantially the same as the height of the reel drive shaft 7 on the side of the standard type magnetic recording / reproducing apparatus described in FIG. Accordingly, the three ribs 54 provided on the outer circumference of the reel feather 53 are also the three ribs 19 provided on the outer circumference of the reel feather 18 on the standard magnetic recording / reproducing apparatus side.
It is almost at the same height position.

Therefore, as shown in FIG. 4, when the high-density tape cassette 40 is mounted in the high-density magnetic recording / reproducing apparatus, the protrusion 47 formed in the reel shaft insertion hole 44 of the tape reel 41 is Since it enters into the recess 57 formed in the center of the head 56 attached to the tip of the reel drive shaft 50 on the side of the high-density magnetic recording / reproducing apparatus, the high-density tape cassette 40 is completely (normally) operated as shown in the figure. Since the reel shaft insertion hole 44 can be mounted, and the depth of the reel shaft insertion hole 44 is deep, a total of nine ridges 45 formed on the inner wall of the reel shaft insertion hole 44 and three ribs formed on the outer circumference of the reel feather 53. The amount of meshing with 54 becomes large, and both 45,
The tape reel 41 is securely engaged with the reel drive shaft 50 of the high-density magnetic recording / reproducing apparatus side and is rotationally driven without disengagement of 54.

When a high-density magnetic recording / reproducing apparatus capable of digital recording / reproducing is newly developed, the high-density magnetic recording / reproducing apparatus has an upward compatibility so that the standard tape cassette described above can be mounted. Even if it is configured to have it, there is no problem even if the concave portion 57 is formed in the central portion of the head portion 56 attached to the tip of the reel drive shaft 50 on the high-density magnetic recording / reproducing apparatus side.

[0034]

According to the tape cassette of the present invention described in detail above, the outer shape of the cassette housing is formed to be substantially the same as that of the standard type tape cassette, and the depth of the reel shaft insertion hole is the same as that of the standard type tape cassette. Approximately the same size is set, and a protrusion is provided at the center of the top surface inside the reel shaft insertion hole, and this protrusion allows the standard tape cassette to be mounted. The standard type magnetic recording / reproducing apparatus side informs the user that the tape cassette according to the present invention is in an imperfectly mounted state, or the tape cassette is imperfectly mounted. Since an operation such as forcibly ejecting can be performed, the user can immediately know that the tape cassette has been erroneously inserted.

Further, when the tape cassette according to the present invention developed for high density is mounted on the high density type magnetic recording / reproducing apparatus, the depth of the reel shaft insertion hole is made substantially the same as that of the standard type tape cassette. Since the setting is made, the amount of meshing between the protrusion formed on the inner wall of the reel shaft insertion hole and the rib formed on the outer periphery of the reel feather becomes large, and the meshing of the two does not disengage, and the tape reel according to the present invention Has an advantage in that it is reliably engaged with the reel drive shaft on the high-density magnetic recording / reproducing apparatus side to be rotationally driven.

[Brief description of drawings]

FIG. 1 is a sectional view showing a state in which a tape cassette according to the present invention is imperfectly mounted in a standard magnetic recording / reproducing apparatus.

2A and 2B are a sectional view and a bottom view showing a tape reel of a tape cassette according to the present invention.

3A to 3C are a side view, a top view, and a cross-sectional view for explaining a reel drive shaft on the high-density magnetic recording / reproducing apparatus side.

FIG. 4 is a cross-sectional view showing a state in which the tape cassette according to the present invention is completely attached to a high-density magnetic recording / reproducing apparatus.

FIG. 5 is a cross-sectional view showing a state in which a conventional standard-type tape cassette compatible with the VHS standard is completely mounted in a standard-type magnetic recording / reproducing apparatus.

6A and 6B are a sectional view and a bottom view showing a tape reel of a conventional standard type tape cassette.

7A and 7B are a side view and a top view for explaining a reel drive shaft on a standard magnetic recording / reproducing apparatus side.

FIG. 8 is a sectional view showing a state in which a conventional special-type tape cassette is imperfectly attached to a standard-type magnetic recording / reproducing apparatus.

9A and 9B are a sectional view and a bottom view showing a tape reel of a conventional special-type tape cassette.

10A and 10B are a side view and a top view for explaining a reel drive shaft on the special type magnetic recording / reproducing apparatus side.

FIG. 11 is a cross-sectional view showing a state in which a conventional special-type tape cassette is completely attached to a special-type magnetic recording / reproducing apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Standard type tape cassette, 3 ... Cassette housing, 7 ... Standard type magnetic recording / reproducing apparatus side reel drive shaft, 40 ... Tape cassette (high density type tape cassette), 41 ... Tape reel, 44 ... Reel shaft insertion hole , 46 ... Top surface, 47 ... Protrusion, 48 ... Magnetic tape, 50 ... High-density magnetic recording / reproducing apparatus side reel drive shaft.

Claims (1)

[Claims] 1. A tape reel in which a magnetic tape is wound is rotatably housed in a cassette housing, and a reel drive shaft on the magnetic recording / reproducing apparatus side is engaged with a reel shaft insertion hole of the tape reel to form the tape reel. In a tape cassette configured to be driven to rotate, the outer shape of the cassette housing is formed to be substantially the same shape as the standard type tape cassette, and the depth of the reel shaft insertion hole is set to be substantially the same size as the standard type tape cassette. A protrusion is provided at the center of the top surface in the reel shaft insertion hole, and the protrusion is provided at the tip of the center of the reel drive shaft on the side of the standard type magnetic recording / reproducing device on which the standard type tape cassette can be mounted. A tape cassette characterized in that the tape cassette comes into contact with the tape to be in an incompletely mounted state.