JP2002093109A - Method for manufacturing sheet-like light shielding plate for tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a light shielding plate by which a sheet-like light shielding plate provided near the opening parts of both right and left side walls of the case of a tape cassette is formed efficiently and accurately. SOLUTION: The method is for manufacturing a sheet-like light shielding plate which has a height corresponding to the inside dimension of the case and having light transmitting hole 31a and is inserted in and held near the opening parts of the tape cassette provided with the opening parts for light transmission used for detecting a tape end in both right and left side walls of a cassette main body. In the cassette main body consisting of upper and lower cases, a pair of tape reels around which a tape-like medium is wound is housed rotatably. In the method, the width direction of a long-sized sheet which has a width corresponding to the inside dimension of the case is set as a height direction of the light shielding plate, and is cut with a cutting die having a cutting part and a light transmitting hole cutting blade so that the light shielding plate is in a connected state in the width direction through a connecting part 33a. Then, the connecting part 33a is cut to separate the light shielding plate 30a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a light shielding plate used in a tape cassette body for detecting an end of a tape by an optical sensor. The present invention also relates to a method for manufacturing a light-shielding plate having a sheet-like light-transmitting hole which is inserted and held in a main body of a tape cassette formed of a resin having a high light transmittance (5% or more).

[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.

[0003] More recently, there has been a demand for tape cassettes that are more colorful than black in design.
As disclosed in Japanese Patent Application Laid-Open No. 3-25595, a portion near a light receiving portion of a portion near a light path portion of light from a light emitting portion of a device inside a case of a tape cassette is colored in a color having a low light reflectance to a light receiving portion. A tape cassette that prevents excess light from being incident on the main part of the case and has the majority of the colored portion of the case colored in a color different from the colored color, and is rich in colorful colors and excellent in decorativeness has been proposed. ing.

Further, as disclosed in Japanese Utility Model Laid-Open Publication No. 63-161487, in order to prevent extra light from entering 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.

[0005]

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 of the case near the opening formed on 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 thin sheet-shaped light shielding plate is more preferable than a thick plate-shaped light shielding plate.

Therefore, a tape cassette using a sheet-shaped light shielding plate has been proposed. In such a tape cassette, the light shielding plate is mounted in the vicinity of a light transmitting opening provided on each of the right and left side walls of the cassette body. Is retained. Although the heights of these light shields are the same, the widths are significantly different, with one light shield being narrower and the other light shield being wider. Therefore, it is required that these light-shielding plates having greatly different width dimensions be efficiently formed, and that the sheet-shaped light-shielding plates must be formed with high precision in order to insert and hold them at predetermined positions of the upper and lower cases. is there.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem, and a case for effectively shielding extra light when a light receiving portion receives light for detecting a tape end in a tape cassette. It is an object of the present invention to provide a method for manufacturing a light-shielding plate for efficiently and accurately forming a sheet-like light-shielding plate provided in the vicinity of an opening on both left and right side walls of the sheet.

[0010]

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. The tape cassette provided with a light transmission opening used to detect the portion is inserted and held near the opening, has a height corresponding to the inner size of the case, and has a light transmission hole. A method of manufacturing a sheet-like light-shielding plate having a width direction of a long sheet having a width corresponding to the inner dimension of the case is defined as a height direction of the light-shielding plate, and a connection state is provided via a connecting portion in a width direction of the light-shielding plate. Then, a cutting die having a cutting portion and a light transmitting hole cutting blade is punched out, and then the connecting portion is cut to cut and separate the light shielding plate to form. Further, the connecting portion is provided at a portion that can be accommodated in the upper case side of the light-shielding plate.

[0011]

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 provided with a light shielding plate according to 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. 3A illustrates a supply-side tape reel side, and FIG. 3B illustrates a take-up-side tape reel side. FIG. 4 is a plan view of the light shielding plate according to the embodiment of the present invention,
(A) shows a flat type, and (b) shows an expanded L-shaped type having a bent portion. FIG. 5 (a)
(A) shows a light-shielding plate which is punched out by being connected to a raw sheet of a long sheet, and (b) shows a light-shielding plate which is separated by cutting (a). 6A and 6B show the L-shaped light-shielding plate of FIG. 4B, wherein FIG. 6A is a light-shielding plate which is punched out by being connected to a long sheet material, and FIG. 2 shows a separated light shield plate.

A tape cassette 1 provided with a light shielding plate according to an embodiment of the present invention will be described. As shown in FIG. 1, the tape cassette 1 has a pair of tape reels 3a, 3b around which a tape-shaped medium 8 is wound rotatably housed in a cassette body composed of upper and lower cases 10, 20. The front surface of the lower case 20 has openings 21a and 21b, and the tape-shaped medium 8 fed from the supply-side tape reel 3a is
It goes out of the case through the opening 21a, returns into the case through the opening 21b, and is wound up on the take-up 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, a lock member 5, which locks the front lid 7 in the closed position,
A reel brake member 6 is provided to prevent the tape reels 3a and 3b from rotating unnecessarily when the cassette is not used. At the center of the inner surface of the upper case 10, a spring member 4 for pressing the tape reels 3a, 3b toward the lower case 20 is provided.
Is attached.

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, sheet-like light-shielding plates 30a and 30b having heights substantially equal to the inner dimensions of the case are mounted. The light-shielding plates 30a and 30b are made of a light-shielding plastic sheet, for example, a polyethylene terephthalate sheet added with carbon black, or a surface-treated paper, for example, a black-printed paper.

As shown in FIG. 2, a cylindrical portion 22 having an open bottom surface is provided at the front central portion 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 a bent 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.

On the other hand, the light-shielding plate 30b is provided at a position slightly away from the side wall 24b because the lock member 5 of the front lid 7 is provided on the inner side of the side wall 24b. Since the light shielding plate 30b is separated from the light transmission opening 25b, the light shielding plate 30b is formed in a size larger than that of the light shielding plate 30a so as to effectively perform light shielding, and the protrusions 2 project alternately from the walls on both sides where the light shielding plate 30a is installed.
6b. The light-shielding plate 30b is
It is bent at the bent portion 32b shown in FIG. 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 shields the light from the light emitting unit to the light receiving unit by detecting that the tape cassette is mounted, the light shielding plate 30 is bent into an L shape, and the light is shielded by the bent part. In the recording / reproducing apparatus as described above, it is possible to prevent a malfunction of whether or not a cassette is mounted.

Next, the light shielding plate 30 according to the embodiment of the present invention will be described.
The molding of a and 30b will be described. Since the light-shielding plate 30a and the light-shielding plate 30b have the same height corresponding to the inner dimension of the case, the width of the raw sheet of the long sheet is reduced by the light-shielding plate 30.
a, 30b, so that the light-shielding plate 3
The raw material is shared by 0a and the light shielding plate 30b so that the raw material can be efficiently managed. The long sheet is made of a light-shielding plastic sheet, for example, a polyethylene terephthalate sheet to which carbon black is added, or a surface-treated paper, for example, a sheet having a light-shielding property, such as black-printed paper. ing.

The width direction of the raw material is the light shielding plate 30 from the raw material.
a, 30b so as to be in the height direction.
The light shielding plate 30 is formed by a cutting die having cutting portions 35a, 35b and light transmitting holes 31a, 31b so as to be connected to each other through the connecting portions 33a, 33b in the width direction of the light receiving plates 30a, 30b.
a and 30b are cut out, and as shown in FIGS. 5 (a) and 6 (a), the light shielding plate 30a, 30b is continuously arranged on the raw sheet of the long sheet via the connecting portions 33a, 33b. The plates 40a and 40b are formed. The light shielding plates 30a, 30b
The connecting portions 33a, 33b
Is provided. Thereafter, the connecting portions 33a and 33b are cut and separated into light shielding plates 30a and 30b, and the light shielding plate 30a or the light shielding plate 30b is formed.

As shown in FIG. 5A, the light transmitting holes 31a
The light-shielding plate 30a having the connecting portion as described above allows the portion that fits in the lower case 20 to have the light transmitting hole 3
1a is formed with sufficient accuracy, so that the light transmitting hole 3
1a is accurately installed at a predetermined location.

Incidentally, as shown in FIG.
a is cut so that the width between the cut portions 34a of the light shielding plate 30a separated by cutting a is smaller than the width of the cutout portion 35a below the cut portion. This is because the width between the cut portions 34a is smaller than the cut portion 35.
This is because if the width is larger than the width a, the width of the light shielding plate becomes narrower at the upper side, which may cause a malfunction in the detection of the tape end. Also,
Since the cut portion 34a of the light shielding plate 30a is not on the lower case 20 side, there is no effect when the light shielding plate 30a is positioned and incorporated into the lower case 20.

Further, the light shielding plate 30a having a small width is formed so that the width direction of the raw material is in the height direction of the light shielding plate 30a. Although the warpage in the long direction, that is, the formed light shielding plate 30a, corresponds to a narrow warp in the width direction, the warp can be ignored. Therefore, by shaping the light shielding plate 30a from the raw material as described above, the light shielding plate 30a is transferred to the upper and lower cases 10, 20.
Insufficient mounting due to warpage when mounting a is prevented.

As shown in FIG. 6A, the light transmitting holes 31b
Similarly, the light-shielding plate 30b having the
By providing 3b, the portion that fits in lower case 20 is formed with sufficient accuracy together with light transmission hole 31b, so that it is accurately inserted and held in a predetermined location of lower case 20, and light transmission hole 31b Is installed with high accuracy.

Incidentally, as shown in FIG.
The width between the cut portions 34b of the light shielding plate 30b separated by cutting b is cut so as to be smaller than the width of the cutout portion 35b below the same for the same reason as in the case of the light shielding plate 30a.
This is because if the width between the cut portions 34b is larger than the width of the cut portion 35b, the width of the light shielding plate becomes narrower upward, which may cause a malfunction in detecting the tape end. Also, the light shielding plate 30b
Is not on the lower case 20 side, so the light shielding plate 30
There is no effect when the b is positioned and assembled into the lower case 20. Further, the warpage of the original fabric can be ignored since the light shielding plate 30b has the bent portion 32b. The light-shielding plate 30b formed as described above is bent at the bent portion 32b and is inserted into a predetermined location of the lower case.

According to the shading plate molding method described above, a method for manufacturing a shading plate that efficiently and accurately forms the shading plates having the greatly different widths can be obtained. The tape cassette using the light-shielding plate is not limited to the tape cassette using the light-transmitting upper and lower cases described above, but may be a tape cassette having an opaque upper and lower case and insufficient light shielding.

[0026]

According to the present invention, a long sheet having a width corresponding to the inner dimension of the case is prepared, the width direction is set to the height direction of the light shielding plate, and the width direction is set to the width direction of the light shielding plate via the connecting portion. It is punched by a cutting die having a cutting portion and a light transmitting hole cutting blade so as to be in a connected state, and then the connecting portion is cut and the light shielding plate is cut and separated, so that individual light shielding from a wide raw sheet is performed. As compared with the case where a plate is stamped and formed, the production is easier, the waste sheet of the raw sheet is less, and the production can be performed at a reduced cost.

[Brief description of the drawings]

FIG. 1 shows a V provided with a light blocking plate according to an embodiment of the present invention.
FIG. 3 is an exploded perspective view of the HS tape cassette.

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.

4A and 4B are plan views of a light-shielding plate according to an embodiment of the present invention, in which FIG. 4A shows a planar type, and FIG. 4B shows an expanded L-shaped type having a bent portion.

5 (a) is a plan view of the light shielding plate of FIG. 4 (a), wherein FIG.
(B) shows the light-shielding plate separated by cutting (a).

6 (a) and 6 (b) show an L-shaped light-shielding plate shown in FIG. 4 (b), wherein FIG.
(B) shows the light-shielding plate separated by cutting (a).

[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-shaped 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 Bends 33a, 33b Connections 34a, 34b Cuts 35a, 35b Cuts 40a, 40b A light shield plate in which light shield plates are continuously arranged on a raw material via a connecting part

Claims (2)

[Claims] 1. A cassette body comprising upper and lower cases,
A tape cassette in which a pair of tape reels wound with a tape-shaped medium is rotatably accommodated, and a light transmitting opening used for detecting a tape end is provided on both right and left side walls of the cassette body. A method for manufacturing a sheet-like light-shielding plate having a height corresponding to an inner dimension of a case and having a height corresponding to an inner dimension of a case, and a width corresponding to the inner dimension of the case, The width direction of the long sheet having the height direction of the light-shielding plate, and punching out with a cutting die having a cutting portion and a light-transmitting hole cutting blade so as to be connected via a connecting portion in the light-shielding plate width direction, and then A method for producing a sheet-shaped light shielding plate for a tape cassette, comprising cutting a connecting portion and cutting and separating the light shielding plate. 2. The method of manufacturing a light-shielding plate according to claim 1, wherein the connecting portion is provided in a portion that is housed in the upper case side of the light-shielding plate.