JPH05217332A - Tape cassette - Google Patents

Abstract

PURPOSE:To lower the cost in simple constitution with a small number of parts and to prevent the occurrence of dust by integrally forming a shutter and a prescribed protrusion out of a synthetic resin and engaging the protrusion with a gear of a reel hub at the time of closing the shutter. CONSTITUTION:The shutter 4 having a U-shaped cross section is slidably provided in the direction of connecting one pair of reel base inserting holes 2 and 3 on the side of a front face part of a case 1, and also the shutter 4 is formed out of a thermoplastic resin. Then, two bends and protrusions 17a and 17b at their tips are provided on the shutter 4 in their prescribed positions, and the reels are locked by engaging the protrusion parts with the gears 16a and 16b provided on the reel hubs 15a and 15b at the time of closing the shutter. Thus, since the shutter 4 is integrally formed out of the synthetic resin, the number of parts is reduced, and the assembly man-hour is simplified, and also the occurrence of dust is suppressed because the sliding parts are all made of the synthetic resin, and drop out can also be suppressed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette for storing a tape capable of recording and reproducing information such as music and images, and more particularly to a shutter structure of a tape cassette and a reel hub locking mechanism.

[0002]

2. Description of the Related Art With the spread of tape cassettes in recent years,
Manufacturing cost is low, dust generation is suppressed, drapout,
There is an increasing demand for tape cassettes that can suppress an increase in error rate.

In a tape cassette containing a tape-shaped recording medium (hereinafter referred to as a tape) as disclosed in JP-A-3-214484, a magnetic head insertion window and a pinch roller insertion window are covered with an openable shutter. This is to prevent the increase of the error rate due to the dust entering from the insertion window and adhering to the recording / reproducing surface of the tape, or the hand touching the recording / reproducing surface of the tape It was to prevent damage.

Further, there is a tape cassette having a reel hub lock mechanism in which the rotation of the reel hub is forcibly stopped in a state where the shutter is closed in order to prevent the winding of the tape from loosening due to vibration during transportation.

[0005]

In such a conventional tape cassette, when the recording / reproducing or the fast-forward rewinding, etc., which is loaded in the recording / reproducing apparatus or the like is carried out in a state where the tape winding is loose, There was a problem that the tape was caught in the tape and stretched, wrinkled, or the tape was broken. In order to solve this, for example, digital audio tapes have a reel hub lock mechanism that uses synthetic resin parts and coil springs, but they require large parts and metal springs. Also, there is a problem that the number of assembling steps increases and the manufacturing cost increases.

When a metal shutter is used, a part of which is bent to form a protrusion, and the protrusion is engaged with a gear provided on the reel hub to lock the reel hub, the reel hub is usually made of synthetic resin. Since the projections formed by bending a part of the metal shutter of the provided gear are scraped, dust is generated, and there is a problem that dropout, error rate, etc. increase.

The present invention solves such a conventional problem, has a simple structure, a small number of parts, is easy to assemble, does not require a manufacturing cost, and can further suppress generation of dust. An object of the present invention is to provide a tape cassette having a shutter structure and a reel hub locking mechanism capable of suppressing an increase in dropout and error rate.

[0008]

In order to achieve the above object, a tape cassette of the present invention has a housing having a tape-shaped recording medium and a reel base insertion hole and an insertion window such as a magnetic head. The window of the housing is slidable so that it opens and closes in the direction connecting the centers of the pair of reel stand insertion holes with a U-shaped cross section consisting of two surfaces parallel to the magnetic head insertion direction and a surface perpendicular to the magnetic head insertion direction. A shutter and a spring stretched between the housing and the shutter so as to close the window of the housing at all times, the shutter is formed of a thermoplastic resin, and is parallel to the head insertion direction of the shutter. On one surface, there are two bent portions that move in the center line direction of the two reel stand insertion holes at right angles toward the inside of the housing, and at this bent portion, there are two bent portions that are arranged inside the housing. Provided on one reel hub Has a projection that engages the gear, and the bent portion and the protrusion are configured integrally molded.

[0009]

According to the present invention, the projection is integrally formed on the bent portion provided on the synthetic resin shutter, and the projection provided on the shutter is engaged with the gear provided on the reel hub to lock the reel hub. With a simple configuration, the number of parts is small, the assembly is easy, the manufacturing cost is low, the generation of dust can be suppressed, and the dropout and the increase in error rate can be suppressed.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
Will be described with reference to. As shown in the figure, a housing 1 in which the tape is housed is provided with a shutter 4 which is substantially U-shaped in cross section and which can be opened and closed in a direction connecting the centers of a pair of reel stand insertion holes 2 and 3, and a window for inserting a magnetic head 5 and windows 6 and 7 for inserting pinch rollers are provided. Then, the spring 8 has one end engaged with the housing 1 and the other end engaged with an L-shaped spring stopper 9 provided on the shutter 4, and windows 5, 6, facing the housing 1.
It is stretched to close 7.

Further, the housing 1 is provided with a sliding portion 10 having a step slightly deeper than the thickness of the shutter 4 within the range in which the shutter 4 slides, and the shutter 4 is larger than the size of the housing 1 in the thickness direction. Also prevents it from going outside. And the shutter 4
The surface 4a is provided with a hole 11 and a notch 12 for opening and closing the reel base insertion holes 2 and 3 of the housing 1, and a bent portion perpendicular to the surface 4a so as to contact the hole 11 and the notch 12. 13a and 13b are provided.

Further, at the tips of the bent portions 13a and 13b, the reel hubs 15a and 15b for winding the magnetic tape 14 contained in the housing 1 are locked, so that the gears 16a and 16b provided on the reel hubs 15a and 15b are locked. Are provided with substantially U-shaped projections 17a and 17b. When the shutter 4 is detached from the housing 1, the surfaces 4a and 4b are brought closer to each other toward the tip. Therefore, when the shutter 4 is assembled and inserted into the housing 1, the surfaces 4a and 4b of the surfaces 4a and 4b are removed. The back side is in close contact with the surface of the housing 1,
It is possible to prevent dust from entering the housing 1.
Further, as the material of the shutter 4, a thermoplastic resin excellent in elasticity and slidability is preferable, and for example, a polyacetal resin or a polyamide resin is suitable. The shutter 4 has a plate thickness of 0.3 mm or more and 0.4 mm in order to have elasticity.
The following range is preferable. When the plate thickness is smaller than this range, the rigidity of the shutter 4 becomes too low and the shutter 4 is easily broken or deformed. If the plate thickness is thicker than this range, the rigidity becomes too high,
The proper elasticity required when the shutter 4 is inserted into the housing 1 is lost.

The folds 13a and 13b and the substantially U-shaped projections 17a and 17b have a curved wall-like thickness near the base for reinforcement, and the folds 13a and 1b for reinforcement.
3b and the substantially U-shaped projections 17a and 17b may have a structure in which the wall thickness increases in an inclined manner as they approach the root.
Further, the folds 13a and 13b may be reinforced by a structure such as a rib provided on the surface on the side having no substantially U-shaped projection.

When the shutter 4 is closed by the tension force of the spring 8, the substantially U-shaped projections 17a and 17b provided on the shutter 4 are provided on the reel hubs 15a and 15b housed in the housing 1. Gears 16a and 16b
And a reel hub 15a on which the magnetic tape 14 is wound.
And 15b are locked.

When the shutter 4 is opened by a force greater than the tension force of the spring 8, the substantially U-shaped projections 17a and 17b provided on the shutter 4 are reel hubs 15a and 15b housed in the housing 1. Gears 16a and 16 provided on the
When the reel hubs 15a and 15b are separated from b, the reel hubs 15a and 15b can freely rotate.

Further, the gears 16a and 16b provided on the reel hubs 15a and 15b have substantially U-shaped projections 17a and 17b.
Are engaged and the reel hubs 15a and 15b are locked.

As described above, when the shutter 4 is assembled and inserted into the housing 1, the back side of the surfaces 4a and 4b is the housing 1.
It is possible to adhere to the surface and prevent dust from entering the housing 1. Further, the shutter 4, the substantially U-shaped projections 17a and 17b provided on the shutter 4, and the reel hub 1
Since 5a and 15b are made of synthetic resin, the shutter 4 slides on the housing 1, and gears 16a and 16b provided on the reel hubs 15a and 15b have substantially U-shaped projections 17a and 17b.
When they are engaged with or disengaged from each other, dust generation due to the sliding parts scraping each other is suppressed.

The results of measuring the tape dropout using the tape cassette constructed as described above are shown in Table 1.

[0019]

[Table 1]

The above-mentioned measurement is carried out after sliding the shutter 4 0 times, 200 times, and 400 times, respectively, and the dropout is 1 msec as a reproduction output and -6 dB or more. The size was detected.

The results of the comparative example are obtained by measuring the shutter made of stainless steel in the same manner as described above.
As shown in (Table 1), it can be seen that the tape cassettes according to the examples of the present invention have an excellent effect of suppressing the occurrence of dropout.

[0022]

As is apparent from the above embodiments, according to the present invention, a casing having a substantially U-shaped cross section, which is composed of two surfaces parallel to the magnetic head insertion direction and a surface perpendicular to the magnetic head insertion direction, is provided. The shutter is slidable to open and close the window in the direction connecting the centers of the pair of reel stand insertion holes, and the shutter is molded with synthetic resin, so the manufacturing process is simplified and the cost is reduced. Made possible. Furthermore, since the shutter is molded from synthetic resin, it does not drop off when the shutter is attached to the housing or when the shutter slides on the housing so that the housing does not scrape and dust is generated. It has become possible to suppress the occurrence of.

Further, since the projection for engaging with the gear provided on the reel hub for locking the reel hub is integrally formed with the synthetic resin on the shutter, the number of parts can be reduced, the number of assembling steps is small, and the manufacturing cost is low. Moreover, since the sliding portion is made of all synthetic resin and dust is suppressed, it is possible to provide a tape cassette that can suppress dropout and increase in error rate.

[Brief description of drawings]

FIG. 1 is a plan view showing an internal structure when a shutter of a tape cassette according to an embodiment of the present invention is closed.

FIG. 2 is a perspective view showing a state in which a shutter of the tape cassette is closed.

FIG. 3 is a perspective view showing a state where the shutter of the tape cassette is opened.

FIG. 4A is a plan view of a shutter of the tape cassette, FIG. 4B is a side view of a shutter of the tape cassette, and FIG. 4C is a front view of a shutter of the tape cassette.

FIG. 5 is a perspective view of a protruding portion of a shutter of the tape cassette.

FIG. 6 is a plan view showing the internal structure of the tape cassette shutter when the shutter is opened.

FIG. 7 is a sectional view of the tape cassette.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 case 2, 3 reel stand insertion hole 4 shutters 4a, 4b surface 5, 6, 7 window 8 springs 13a, 13b bent portion 14 magnetic tape 15a, 15b reel hub 16a, 16b gear 17a, 17b protrusion

Claims (6)

[Claims] 1. A casing having a reel base insertion hole and an insertion window such as a magnetic head for accommodating a tape-shaped recording medium, two surfaces parallel to the magnetic head insertion direction and perpendicular to the magnetic head insertion direction. And a shutter that is substantially U-shaped in cross section and is slidable so as to open and close a window of the housing in a direction connecting the centers of the pair of reel base insertion holes, and the housing is always provided between the housing and the shutter. And a spring stretched so as to close the window of the shutter, the shutter is formed of a thermoplastic resin, and the shutter moves in the direction of the center line of the two reel stand insertion holes on one surface parallel to the head insertion direction of the shutter. And two bent portions that are perpendicular to the inside of the housing, and the bent portions have protrusions that engage with gears provided on two reel hubs arranged in the housing, and The folds and protrusions When the integrally molded tape cassette. 2. The tape cassette according to claim 1, wherein the shutter plate has a thickness of 0.3 mm or more and 0.4 mm or less. 3. The tape cassette according to claim 1, wherein the shape of the protrusion as viewed from the direction perpendicular to the head inserting direction is substantially U-shaped. 4. The tape cassette according to claim 1, wherein one or a plurality of ribs are provided on the surface of the bent portion on the side not having the protrusion. 5. The tape cassette according to claim 1, wherein the wall thickness of the bent portion is increased in an inclined shape or a curved shape as it approaches the shutter surface. 6. The tape cassette according to claim 3, wherein the wall thickness of the projection is increased in a slanted or curved shape as the thickness approaches the surface of the bent portion.