JP2002093112A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape cassette in which a laminated light shielding plate provided near the opening part of the case side wall is inserted and held for shielding effectively excessive light when light for tape end detection is received by a light receiving part and for obtaining an effective light shielding effect. SOLUTION: In a tape cassette 1 provided with opening parts for transmitting light used for the purpose of detecting a tape end on both right and left side walls of a cassette main body, in which light shielding plates having light transmitting holes are inserted and stuck near the opening parts, the light shielding plates 30a and 30b have a height corresponding to the inner side size of the case, and are formed of a sheet having a thickness of 80-200 μm and obtained by adding carbon black to polyethylene terephthalate. The addition of carbon black is also suitable by 3-5 wt.%, furthermore, the surface roughness of the polyethylene terephthalate sheet in which the carbon black is added may be 7 μm or more in the ten-point average of roughness height (Rz).

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 detecting an end portion of a tape by an optical sensor, and more particularly, to a case in which a case main body is made of a transparent resin, a translucent resin, or opaque, and has a high light transmittance (5). %)
The present invention relates to a tape cassette provided with a sheet-shaped light shielding plate inside a case body.

[0002]

2. Description of the Related Art In a conventional tape cassette used in a recording / reproducing apparatus using a magnetic tape as a recording medium, for example, a tape cassette type audio tape recorder, a tape cassette type video tape recorder, a tape cassette type digital audio tape recorder, etc. In order to reliably detect the end of the tape, cut off extraneous light from outside, and to prevent extra light from being reflected inside the tape cassette and incident on the light receiving part of the device, most tapes The cassette case was colored dark, such as black, except for a transparent window for checking the remaining amount of tape, and a light-shielding wall was provided at an appropriate place in the case. More recently, there has been a demand for a tape cassette that is more colorful than black in design. Of the portions, the portion near the light receiving portion is colored with a low light reflectance color to prevent extra light from being incident on the light receiving portion, and the majority of the remaining colored portion of the case is the colored color. There is proposed a tape cassette which is colored in a different color and is rich in colorful colors and excellent in decorativeness.

As shown in Japanese Utility Model Laid-Open No. 63-161487, in order to prevent extra light from being incident on the light receiving section, light from the light emitting section located in the case of the tape cassette is received. A light-shielding wall, which is located between an opening formed in the side wall of the case and a window for checking the remaining amount of tape provided on the upper surface of the case and has at least one of upper and lower sides opened, is integrated with the case. Has been proposed.

[0004]

In a tape cassette using a case composed of an upper case and a lower case, the tape cassette which is rich in colorful colors and has excellent decorativeness, or at least the upper case is made of a material having a high light transmittance, For example, in a tape cassette using a case molded of a transparent, colored transparent, translucent or colored translucent resin, in order to obtain a necessary light shielding effect, the vicinity of the light receiving portion is coated with a different color from the other case body. The method of applying and coloring is problematic in that the number of manufacturing steps is longer, time is required, and the manufacturing cost is higher than in the case of manufacturing a conventional single-color case body.

In a tape cassette in which a light-shielding wall is formed integrally with a lower case in a case near a light-receiving portion, the light-shielding wall is opaque if at least the upper case is formed of the material having a high light transmittance. Even if it is formed integrally with the lower case, there is no light-blocking effect because the upper case side of the light-blocking wall is open, and if the light-blocking wall is formed integrally with the upper case, the light-blocking wall transmits light. Even if the case is opaque, there is a problem that the light shielding wall has no light shielding effect.

A necessary light-shielding effect can be obtained by providing a light-shielding plate having a height from the lower surface to the upper surface in the case near the opening formed in the side wall of the case for receiving the light from the light emitting section. Therefore, a malfunction at the time of detecting the end of the tape can be prevented, but since the conventional case was formed of an opaque resin and did not require a light shielding plate, there was no space for the light shielding plate. . Therefore, from the viewpoint of space, a sheet-shaped light-shielding plate is more preferable than a thick plate-shaped light-shielding plate, but there is a problem in the material of the sheet that can provide an effective light-shielding effect.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to provide a tape cassette using a case formed of a material through which light can pass. The manufacturing time is shorter and the manufacturing cost is lower than with the conventional method of applying a different color paint to a part. In addition, when the light for detecting the end of the tape is received by the light receiving section, extra light is effective. It is an object of the present invention to provide a tape cassette provided with a light-shielding plate provided in the vicinity of an opening of a case side wall for light-shielding and capable of obtaining an effective light-shielding effect.

[0008]

According to the present invention, a pair of tape reels each having a tape-shaped medium wound thereon are rotatably accommodated in a cassette body composed of upper and lower cases, and tape end portions are provided on left and right side walls of the cassette body. In a tape cassette provided with a light-transmitting opening used to detect the light-transmitting portion, and a light-shielding plate having a light-transmitting hole in the vicinity of the opening, the light-shielding plate corresponds to an inner dimension of a case. It is formed of a sheet having a height of 80 to 200 μm and a thickness of 80 to 200 μm in which carbon black is added to polyethylene terephthalate.

Further, the amount of the carbon black added is
The polyethylene terephthalate sheet to which the carbon black is added may have a surface roughness of 7 μm or more in ten-point average roughness (Rz).

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is an exploded perspective view of a VHS tape cassette showing an embodiment of the present invention.
FIG. 2 is a plan view of the tape cassette of FIG. 3A and 3B are enlarged views of the light shielding plate accommodating portion shown in FIG. 2, wherein FIG.
Indicates the take-up side tape reel side. FIG. 4 is a plan view of a light-shielding plate according to an embodiment of the present invention, wherein FIG.
(B) shows an L-shape expanded.

As shown in FIG. 1, a tape cassette 1 has a pair of tape reels 3a and 3b around which a tape-shaped medium 8 is wound. Opening 2 on the front of lower case 20
The tape-shaped medium 8 fed from the supply-side tape reel 3a exits the case through the opening 21a, returns into the case through the opening 21b, and is wound on the winding-side tape reel 3b. A front lid 7 is rotatably mounted to protect the tape-shaped medium 8 outside the case.

Inside the lower case 20, there are provided a lock member 5 for locking the front cover 7 in the closed position, and a reel brake member 6 for preventing the tape reels 3a and 3b from rotating unnecessarily when the cassette is not used. Have been. Upper case 1
A spring member 4 for pressing the tape reels 3a, 3b toward the lower case 20 is attached to the center of the inner surface of the inner case 0.

The upper and lower cases 10, 20 are made of a transparent resin, a translucent resin, or a resin that is opaque and has a high light transmittance (5% or more). Near the left and right side walls on the front side of the lower case 20, light blocking plates 30a and 30b having heights substantially equal to the inner dimensions of the case are mounted. The light shielding plate is formed of a polyethylene terephthalate sheet to which carbon black has been added.

As shown in FIG. 2, a cylindrical portion 22 having an open bottom surface is provided at the center of the front side of the lower case 20. When the tape cassette 1 is mounted on the recording / reproducing apparatus, the light emitting section ( (Not shown) enters the tubular portion 22. The light emitting portion enters the cylindrical portion 22, and light from the light emitting portion proceeds in the direction of arrow r. Outside the light transmission openings 25a, 25b provided in the side walls 24a, 24b of the case, there is a light receiving section (not shown) of the recording / reproducing apparatus for detecting the light. While the tape-shaped medium 8 is running, the light emitted from the light-emitting portion does not pass through the portion of the tape-shaped medium 8 on which the magnetic material is applied, so that the light is not detected by the light-receiving portion, and the magnetic material approaches the tape end. When a transparent leader tape is connected to the tape-shaped medium, the light passes through the leader tape, is detected by the light receiving unit, and the end of the tape is detected.

The light shielding plates 30a and 30b are connected to the side wall 2 in the case.
Arranged in the vicinity of 4a and 24b, light is shielded so that light from other than the light emitting unit does not enter the light receiving unit, thereby preventing a malfunction in tape end detection. Supply tape reel 3
The light-shielding plate 30a on the a-side is a flat type, and the light-shielding plate 30b on the winding-side tape reel 3b side is bent into an L-shape.

As shown in FIG. 3, the light shielding plate 30a is provided on the inner side of the light transmitting opening 25a in the side wall 24a. The light shielding plate 30a is provided with the light transmitting holes 3 shown in FIG.
The lower case 20 is sandwiched and fixed by a rib 26a and a projection 26a formed on the side wall 24a of the lower case 20 so that 1a coincides with the light transmitting opening 25a of the side wall 24a.

The light-shielding plate 30b is provided at a position slightly away from the side wall 24b because the lid lock member 5 is provided on the inner side of the side wall 24b. Since the light-shielding plate 30b is separated from the light-transmitting opening 25b, the light-shielding plate 30b is formed in a size larger than that of the light-shielding plate 30a so that light is effectively shielded, so that light is effectively shielded. In the recording / reproducing apparatus, a light emitting unit is provided behind the take-up tape reel 3b of the tape cassette mounted in the recording / reproducing apparatus in order to detect whether the tape cassette is mounted in the recording / reproducing apparatus. Some have a light receiving part in front. Since the tape cassette blocks light from the light-emitting unit to the light-receiving unit, it is detected that the tape cassette is mounted. In the recording / reproducing apparatus as described above, malfunction can be prevented. Light shield plate 3
Ob is pinched and fixed by protruding portions 26b that alternately protrude from the walls on both sides where the Ob is installed. The light shielding plate 30b
It is bent at the bending line 32b shown in FIG.

The light-shielding plates 30a and 30b are formed of a polyethylene terephthalate sheet having a thickness of 80 to 200 μm in which the addition amount of carbon black is 3 to 5% by weight.
Light unnecessary for tape end detection can be sufficiently shielded. Further, the polyethylene terephthalate sheet is strong and relatively inexpensive, and thus is suitable for a light shielding plate.

When the thickness of the polyethylene terephthalate sheet to which carbon black has been added is less than 80 μm, the sheet loses its stiffness, easily falls down after being incorporated into the lower case 20, and causes problems such as pinching when the upper case 10 is covered. Is not preferred. On the other hand, if the thickness is more than 200 μm, the workability of punching and cutting becomes worse, and the material cost per shield plate increases. On the other hand, if the amount of carbon black is small, light is transmitted and there is no light-blocking effect, and if the amount is too large, the light-shielding plate becomes brittle and the bendability decreases, making it difficult to use.

Further, roughening the surface of the light-shielding plate is more preferable because it has the effect of reducing the light transmittance and the effect of reducing the light reflected by the light-shielding plate and suppressing the adverse effect on the light shielding. As the surface roughness of the light-shielding plate, the ten-point average roughness (Rz) is preferably 7 μm or more.

Therefore, when the light shielding plate of the present invention is used in a tape cassette using upper and lower cases formed of a transparent resin, a translucent resin, or an opaque resin having a light transmittance of 5% or more. This is effective for light shielding relating to the detection of the tape end. Also, in the case of a tape cassette having an opaque case, when the light incident from a transparent window or the like provided in the upper case cannot be sufficiently shielded and there is a problem in detecting the end of the tape, the light-shielding plate of the present invention is used. Thus, a sufficient light-shielding effect can be obtained.

As described above, by using a light-shielding plate made of a polyethylene terephthalate sheet to which carbon black has been added, a light-shielding effect necessary for detecting the end of the tape can be obtained.

[0023]

According to the present invention, there is provided a light shielding plate of the present invention in a tape cassette using upper and lower cases formed of a transparent resin, a translucent resin, or an opaque resin having a light transmittance of 5% or more. The light shielding can be effectively performed simply by inserting the tape cassette into the case, so that the tape cassette can be easily manufactured and assembled at low cost.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a VHS tape cassette showing an embodiment of the present invention.

FIG. 2 is a plan view of the tape cassette of FIG. 1 with the front side partially cut away.

FIG. 3 is an enlarged view of a light shielding plate housing shown in FIG. 2;
(A) shows the supply side tape reel side, (b) shows the winding side tape reel side.

FIG. 4 is a plan view of a light shielding plate according to the embodiment of the present invention;
(A) shows a flat type, and (b) shows an L-shaped type.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tape cassette 3a Supply side tape reel 3b Take-up side tape reel 4 Spring member 5 Lock member 6 Reel brake member 7 Front lid 8 Tape medium 10 Upper case 20 Lower case 21a, 21b Opening 22 Tubular part 24a, 24b Side wall 25a , 25b Light transmission openings 26a, 26b Projections 27a Ribs 30a, 30b Light shields 31a, 31b Light transmission holes 32b Bending lines

Claims (3)

[Claims] 1. A cassette body comprising upper and lower cases,
A pair of tape reels around which a tape-shaped medium is wound are rotatably accommodated, and light-transmitting openings used to detect tape ends are provided on both right and left side walls of the cassette main body. In a tape cassette in which a light-shielding plate having a light-transmitting hole is inserted and held, the light-shielding plate has a height corresponding to an inner dimension of a case, and has a thickness of 80 to 200 μm in which carbon black is added to polyethylene terephthalate. A tape cassette characterized by being formed by: 2. The addition amount of the carbon black is 3 to 3.
The tape cassette according to claim 1, which is 5% by weight. 3. The polyethylene terephthalate sheet to which the carbon black is added has a surface roughness of 7 μm or more in ten-point average roughness (Rz).
The tape cassette according to the above.