JPH0935452A - Tape cassette - Google Patents

Abstract

(57) Abstract: In a tape cassette having a tape guide portion for guiding the traveling of an exposed tape on the front surface of a cassette body, when the tape is traveling at a high speed, the tape faces the tape guiding portion. To prevent the tape from being scratched or scratched. SOLUTION: In the tape cassette, a plurality of step portions are provided in a tape guide portion 20 so that a tape facing surface 21 thereof is stepwise inwardly higher than both ends of the tape guide portion 20 in the tape running direction. It has a raised shape with 21a-21g. The height of the highest step 21d is
The highest stepped portion 21 of the tape T1 during normal high speed running
The tape T1 is set to contact only d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette mainly used for video tape recorders and the like.

[0002]

2. Description of the Related Art FIG. 7 is a perspective view showing a conventional tape cassette for a general video tape recorder, and FIG. 8 is its internal configuration diagram. With reference to these figures, the conventional tape cassette has a magnetic tape T wound around reels 1 and 2.
Is accommodated in a tape cassette body 5 composed of an upper casing 3 and a lower casing 4, and a part of the tape T is supported by the tape guide portion 6 and exposed to the front surface portion of the tape cassette body 5. When the tape cassette is not used, the guard panel 7 is rotatably supported by the tape cassette body 5.
Covers the exposed portion.

When the above-mentioned tape cassette is loaded into a video tape recorder and recording or reproduction is performed, the tape T is pulled out and mounted on a rotary head drum in the video tape recorder. Further, at the time of high-speed tape feeding or high-speed tape rewinding, the tape T is pulled back into the tape cassette, while the exposed portion of the tape T is the tape guide portion 6
High-speed feeding or high-speed rewinding is performed while being supported by.

In recent years, due to the demand for shortening the feeding time and the rewinding time, the feeding and rewinding are performed at a very high speed of 200 times or 250 times. By the way, there is a phenomenon that the tape T sticks to the tape facing surface 6a of the tape guide portion 6 due to static electricity generated by friction between the tape T and the tape facing surface 6a of the tape guide portion 6 during the high speed tape running. Various measures have been taken to prevent this.

Specifically, there has been proposed a tape-opposing surface 6a having fine irregularities such as a satin finish (hereinafter referred to as "prior art 1"). Further, as shown in FIG. 9, Japanese Patent Laid-Open No. 61-5487 proposes that the tape-opposing surface 6a is provided with a concave portion 9 partitioned by a projecting edge 8 in the tape traveling direction (hereinafter, referred to as "tape"). , "Prior Art 2").

[0006]

The following problems are pointed out in the above prior art. That is, (1) In the prior art 1 in which the tape facing surface 6a of the tape guide portion 6 is subjected to the satin finish, if the surface roughness of the satin finish is not so rough, the tape facing surface 6 of the tape guide portion 6 of the tape T will be described.
If the effect of preventing sticking to a is not sufficiently exerted, while the surface roughness of the satin finish is too rough, the release resistance at the time of molding and removal from the mold becomes large, resulting in difficulty in releasing the mold. Will be difficult.

(2) The tape facing surface 6a of the tape guide portion 6
In the prior art 2 in which the protruding edge 8 and the recessed portion 9 are provided, when the number of the protruding edges 8 is small at the time of high-speed rewinding, the contact area between the tape T and the protruding edges 8 is small, so that the protruding edges 8 are caused by static electricity. However, since the tape T runs at a high speed on the concave portion 9 while being stretched between the projecting edges 8, sticking of the tape T to the concave portion 9 due to static electricity cannot be completely removed. The air in the recess 9 is
The concave portion 9 flows out from the projecting edge 8 in the traveling direction and has a negative pressure in the concave portion 9, and as a result, the tape T is attracted to the bottom surface of the concave portion 9 due to the differential pressure. If the tape running continues with the suction thus generated, the tape T may be damaged because the friction between the projecting edge 8 and the tape T is very large. Also, for example, when the winding speed of the take-up reel and the sending speed of the delivery reel are unbalanced, and the tape flaps, which causes a momentary slack in the tape, etc. The tape T sticks to the bottom surface of the recess 9.

The present invention has been made in view of the above technical problems, and prevents the tape from being adsorbed on the tape-opposing surface of the tape guide portion or scratched when the tape is running at a high speed. However, it is an object of the present invention to provide a tape cassette that allows the tape to run smoothly and is easy to manufacture.

[0009]

In order to achieve the above object, the problem solving means according to the invention of claim 1 accommodates a reel around which a tape is wound, and a part of the tape is a cassette body. In the tape cassette, which is exposed along the front surface and has a tape guide portion for guiding the traveling of the exposed tape on the front surface portion of the cassette body, the tape guide portion includes:
The tape-opposing surface has a raised shape having a plurality of steps so that the tape-facing surface is stepwise higher inward than both ends of the tape guide portion in the tape running direction, and the height of the highest step is It is characterized in that the tape is set so as to come into contact only with the highest step portion when the tape is normally running at high speed.

In the above structure, the tape is in contact with only the highest step portion during normal high speed running in which the running tape does not flutter, and both sides of this highest step portion in the tape running direction are open. When moving the tape in either direction, the high-speed running tape makes it easier for air to be drawn between the tape and the highest step, and as a result, a thin air layer is easily formed between the tape and the highest step. Become. In addition, even if the running tape flaps and the tape is momentarily loosened, the tape contacts the edge of each step except the highest step, so make sure that there is a gap in the step between each step. By forming the ridge, it is possible to receive the momentary slack in the tape at the edge of each step and immediately return to the normal high-speed running state. In addition, the mold release resistance from the mold at the time of molding does not become large as compared with the case where the surface roughness is roughened by the satin finish.

In the embodiment, FIGS. 3 and 4 are used.
As shown in FIG. 3, the edge of each step is rounded to make the contact with the tape softer. According to a second aspect of the present invention, in the tape cassette according to the first aspect, at least the highest step portion has a curved shape protruding toward the tape side.

In the above structure, since the highest step portion has a curved shape projecting to the tape side, the contact area with the tape is reduced, and the high-speed running tape further draws air between the tape and the highest step portion. Acts to facilitate. According to a third aspect of the present invention, in the tape cassette according to the first or second aspect, the portion connecting the adjacent step portions is inclined in the same direction as the inclination direction of the stairs. It is what

In the above structure, the tape softly hits the edge of each step even when fluttering occurs at high speed. According to a fourth aspect of the present invention, in the tape cassette according to any one of the first to third aspects, at least one stepped portion has a cutout concave portion that is open to a lower stepped portion side at an edge portion. It is characterized by having.

In the above structure, the area of the edge portion where the tape comes into contact when fluttering can be reduced, the generation of static electricity due to friction can be suppressed, and the adsorption of the tape can be prevented.
In addition, since the cutout recess is open to the lower step side, air can always be supplied, and the cutout recess does not become negative pressure.

[0015]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a perspective view showing a tape cassette according to a first embodiment of the present invention, in which a guard panel covering a front surface portion and a tape exposed at the front surface portion are omitted. Referring to FIG. 1, the tape cassette according to the present exemplary embodiment includes a cassette body 10 in which a reel (not shown) around which a tape is wound and a front portion of the cassette body 10 are formed. 10
And a tape guide portion 20 for guiding the running of a part of the tape exposed on the front surface of the tape.

The cassette body 10 comprises an upper casing 11 and a lower casing 12 made of synthetic resin, which are connected to each other. 2A is an enlarged bottom view of the tape guide portion, FIG.
(B) is an enlarged front view of the same. With reference to these drawings, the tape guide portion 20 has a plurality of step portions 21a such that the tape facing surface 21 is stepwise higher inward than both ends of the tape guide portion 20 in the tape running direction. , 21b, 21c, 21d, 21e, 21f,
It has a raised shape having 21 g and has a step 21 at the center.
d is the highest. The height of the central step portion 21d is set so that the tape comes into contact with only the step portion 21d during normal running in which fluttering of the tape does not occur. In the following description, the step portion 21d at the central portion where the protrusion is highest is referred to as the "highest step portion 21d".
Called.

FIG. 3 is an enlarged cross-sectional view of the main part of the tape guide portion, showing a normal high speed running state of the tape. Referring to the figure, when the tape T1 is running at a high speed such as fast forward and rewind, the tape T1 mounted on the rotary head drum in the video tape recorder is pulled into the cassette body 10. And only part of it is the cassette body 1
The tape is transferred from one reel in the cassette body 10 to the other reel while being supported by the tape guide portion 20 exposed on the front surface of the cassette 0. At this time, the tape T1 exposed on the front surface of the cassette body 10 travels while being supported only by the highest step portion 21d of the tape facing surface 21 of the tape guide portion 20 during normal high speed running without fluttering of the tape. Therefore, as compared with the case where the tape facing surface 21 of the tape guide portion 20 is a flat surface that does not have a raised shape, the contact area with the tape T1 is smaller, and the attraction to the tape facing surface 21 due to static electricity is reduced. Since both sides of the highest step portion 21d in the tape traveling direction are open, air is drawn between the tape T1 and the highest step portion 21d by the high speed traveling tape during tape traveling in either direction. Tape T1 and the highest step 2
A thin air layer is easily formed between 1d and 1d. As a result, friction between the tape T1 and the tape guide portion 20 is further reduced, generation of static electricity is suppressed, and the tape T1 can be smoothly run without damaging the tape T1.

FIG. 4 is an enlarged cross-sectional view of the main part of the tape guide portion, showing a state where the tape flaps occur. Referring to the figure, even if the running tape flutters and the tape T1 is momentarily loosened, the tape T1
1 is each step 21a, 21b, 21 excluding the highest step 21d
Since it contacts the edge D of c, 21e, 21f, 21g,
Since the gap A is always formed in the step between the step portions 21a to 21g, the edge D of each step portion 21a to 21g receives the momentary slack of the tape T1 and immediately becomes the normal high-speed running state. Can be returned. As a result, the tape TI does not adhere to the step portions 21a to 21g, and the tape T1 does not stick.

In addition, the release resistance from the mold at the time of molding does not become large unlike the conventional case where the surface roughness is roughened by the satin finish. As a result, the mold is easily released, and the manufacturing is easy. FIG. 5 is an enlarged cross-sectional view of the main parts of the tape guide portion of the tape cassette according to the second embodiment of the present invention. Referring to the figure, the feature of the tape cassette of the present embodiment is that the outer surface of the highest step portion 21d has an R shape protruding toward the tape T1 side to further reduce the contact area with the tape T1. Adjacent steps 21a-2
The part C connecting between 1g is inclining in the same direction as the inclining direction of the stairs, and other configurations are substantially the same as in the first embodiment.

In the embodiment of FIG. 5, the step portion 21
The edges D of a to 21 g are rounded to make the contact with the tape T1 softer. In the above configuration, since the highest step portion 21d has the R shape protruding toward the tape side, the high-speed running tape acts so that the air is more easily drawn between the tape T1 and the highest step portion 21d. Further, even if fluttering occurs at high speed running, the tape T1 is softly received by the edge D of each of the step portions 21a to 21g. As a result, each step 2
Damage to the tape from the edge D of 1a to 21g can be further reduced.

FIG. 6 (a) is an enlarged front view of the main portion of the tape guide portion of the tape cassette according to the third embodiment of the present invention, FIG.
(A) is an enlarged cross-sectional view of the main part of the same. With reference to these figures, the feature of the tape cassette of the present embodiment is that the edge of each step 21b, 21c, 21e, 21f in the tape running direction is the same except for the highest step 21d and the lowest steps 21a, 21g. In the central part including the part D, approximately V opened to the lower step part side
The point is that a V-shaped notch recess 30 is formed, and other configurations are substantially the same as those in the first embodiment.

In the above structure, the area of the edge portion D where the tape contacts when fluttering can be reduced, the generation of static electricity due to friction can be suppressed, and the adsorption of the tape can be prevented. Since the cutout recess 30 is open to the lower step portion side, air can always be supplied and the cutout recess does not become negative pressure. As a result, when the tape flutters while the tape is running, the gap formed by the step between the steps 21a to 21g becomes larger. Therefore,
Adhesion of the tape during flapping can be prevented more reliably.

The present invention is not limited to the above-described embodiment. For example, in the second embodiment, a curved shape (for example, an arc shape) in which the step portions other than the highest step portion 21d also protrude toward the tape T1 side. ). Further, the cutout recess 30 in the third embodiment is not limited to the substantially V-shape, but any shape such as a semicircle, a semi-oval, a rectangle, etc. that is open to the lower step side can be used. It may have such a shape.

Of course, various design changes and modifications can be made within the scope of the claims of the present invention.

[0025]

As is apparent from the above description, claim 1
According to the invention described above, when the tape is running normally, the running tape is supported only by the highest step portions that are open on both sides in the tape running direction, so that air is drawn between the running tape and the highest step portion to reduce the thickness between the two. An air layer can be formed. As a result, it is possible to reduce friction on the tape, suppress the generation of static electricity, and smoothly run the tape without damaging the tape. In addition, even if the running tape flaps and the tape is momentarily loosened, the loosened tape is received only at the edge of each step with a gap provided between the loose tape and the tape. Then, it is possible to immediately return to the normal high-speed running state in which only the highest step portion comes into contact with the tape. In addition, unlike the conventional method in which the surface roughness is roughened by the satin finish, the mold release resistance from the mold at the time of molding does not increase, so the mold release is easy,
Easy to manufacture.

According to the second aspect of the invention, air is more easily drawn in between the high-speed running tape and the highest step portion, and the friction against the tape can be further reduced. According to the third aspect of the present invention, even if the tape flaps during high-speed running, the tape is softly received by the edge of each step, resulting in damage to the tape from the edge of each step. Can be less.

According to the fourth aspect of the present invention, the area of the edge portion where the tape comes into contact when fluttering can be reduced, the occurrence of static electricity due to friction can be suppressed, and the adsorption of the tape can be prevented. As a result of the open notched recess not being negative pressure, it is possible to further reliably prevent the tape from being sucked.

[Brief description of drawings]

FIG. 1 is a perspective view showing a tape cassette according to a first embodiment of the present invention, in which a guard panel covering a front surface portion and a tape exposed at the front surface portion are omitted.

FIG. 2 (a) is an enlarged bottom view of the tape guide portion, FIG.
(B) is the enlarged front view.

FIG. 3 is an enlarged cross-sectional view of a main part of a tape guide portion, showing a normal high-speed running state of the tape.

FIG. 4 is an enlarged cross-sectional view of a main part of the tape guide portion, showing a state where fluttering has occurred in the high-speed running tape.

FIG. 5 is an enlarged sectional view of an essential part of a tape guide portion of a tape cassette according to a second embodiment of the present invention.

FIG. 6 (a) is an enlarged front view of an essential part of a tape guide portion of a tape cassette according to a third embodiment of the present invention, FIG.
(A) is an enlarged cross-sectional view of the relevant part.

FIG. 7 is a perspective view showing a conventional tape cassette for a general video tape recorder.

FIG. 8 is likewise an internal configuration diagram thereof.

FIG. 9 is an enlarged bottom view of the tape guide portion of the tape cassette according to the related art 2.

[Explanation of symbols]

 10 cassette body 20 tape guide portion 21 tape facing surface 21a to 21g step portion 21d highest step portion 30 notch concave portion T1 tape C connecting portion D edge portion

Claims (4)

[Claims] 1. A tape guide part for accommodating a reel around which a tape is wound, a part of the tape being exposed along the front surface of the cassette body, and guiding the exposed tape to the front surface of the cassette body. In the tape cassette, the tape guide portion has a raised shape having a plurality of steps so that the tape-opposing surface is stepwise higher inward than both ends of the tape guide portion in the tape running direction. The tape cassette is characterized in that the height of the highest step portion is set so that the tape only comes into contact with the highest step portion when the tape is normally running at high speed. 2. The tape cassette according to claim 1, wherein at least the highest step portion has a curved shape protruding toward the tape side. 3. The tape cassette according to claim 1, wherein the portion connecting the adjacent step portions is inclined in the same direction as the inclination direction of the stairs. 4. The tape cassette according to any one of claims 1 to 3, wherein at least one step portion has a cutout concave portion which is open to a lower step portion side at an edge portion. .