JPH03141089A - Tape cassette - Google Patents

Abstract

PURPOSE:To simplify the manufacturing process and to remarkably reduce the cost by forming integrally a window plate and a detecting member by a transparent resin by a two-color forming method with respect to the upper half formed by an opaque resin. CONSTITUTION:By a first lower metallic mold 30 and the upper metallic mold 31, a half 2 is formed by injecting a molten opaque resin into a cavity 32 for forming the upper half 2. Thereafter, as shown in the figure B, by combining a second metallic mold 33 to the metallic mold 31 and the half 2, an injecting a molten transparent resin into a cavity 34 for forming an integrated transparent member 29, a member 29 is formed. In this case, by heat and injection pressure of the molten transparent resin, a contact part with this molten transparent resin of the half 2 hardened already becomes a semi-molten state. By hardening again the half 2 in this semi-molten state, and also, hardening the transparent resin, the member formed by the transparent resin is formed integrally with the half 2. In such a way, it is unnecessary to assemble a window plate of a separate body, a prism, etc., and the manufacturing process can be simplified.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tape cassette suitable for use in recording digital signals, such as PCM signals.

[Summary of the invention]

The tape cassette of the present invention greatly simplifies the manufacturing process by forming the viewing window plate and the detection member from transparent resin using a two-color molding method on the upper half of the cassette case made from opaque resin. This enabled cost reduction.

[Conventional technology]

BACKGROUND ART Currently, a PCM recording and reproducing apparatus has been proposed that converts an analog signal such as an acoustic signal into a digital signal, such as a PCM signal, and records (or reproduces) the converted signal on a magnetic tape. Some PCM recording and reproducing apparatuses use a rotating head to achieve a relatively high recording density. In a PCM recording/reproducing apparatus using this rotary head, during recording or reproduction, a magnetic tape is pulled out from a tape cassette and loaded onto a rotating drum provided with a rotary head, and then recording or reproduction is performed.

By the way, in the tape cassette in which this magnetic tape is loaded, if a finger touches the magnetic tape and oil or fat or dust gets on it, a dropout occurs in the playback signal. It is necessary to seal the magnetic tape as tightly as possible to prevent it from sticking. Furthermore, a space is required for inserting a guide system so that the magnetic tape can be pulled out from the tape cassette during recording or reproduction.

For this reason, a tape cassette as shown in FIG. 3 and subsequent figures has been proposed. That is, in the figure, (1) indicates a cassette case, and this cassette case (1) is composed of a pair of upper half (2) and lower half (3) that are joined together by a snap stopper. (2a) is a transparent window plate provided on the upper surface of the upper half (2), and the inside of the cassette case (1) can be seen through this window plate (2a). (4
a) and (4b) are housed in the cassette case (1) and are rotatably fitted into a pair of reel shaft insertion holes (5a) and (5b) provided at predetermined positions in the lower half (3). This pair of reel hubs (4
A magnetic tape (6) is wound around a) and (4b).

(7a) and (7b) are tape guide columns provided near the left and right side walls facing the front surface, respectively, and the magnetic tape (6) is wound around these tape guide columns (7a) and (7b). This allows the vehicle to travel at a predetermined position on the front surface. (3a) is the tape guide column (7a) and (
The lower half (3) on the back side of the magnetic tape (6) wound on the magnetic tape (7b) is a notch cut out in a substantially rectangular shape over a predetermined width, and this notch (3a) is cut out over a predetermined width. A guide system for pulling out a magnetic tape from a recording/reproducing device is inserted into the inside.

(8) are arm parts (8a) and (8) provided on both left and right sides.
b) is a front cover that is pivotally supported so as to be able to rotate toward the front side of the cassette case (1), and the front side of the cassette case (1) is opened and closed by this front cover (8).

(9) is a substantially U-shaped slider that faces the lower surface and left and right side walls of the lower half (3) and slides in the front-rear direction. Further, (9a) and (9b) indicate that the slider (9) corresponds to the reel shaft insertion hole (5a) and (5b) when the slider (9) is slid backward to open the notch (3a). 9) is a hole for inserting the reel shaft. Note that (10a) and (10b) are positioning holes provided on the lower surface side corresponding to the tape guide columns (7a) and (7b), respectively.

As shown in Fig. 5, such a tape cassette consists of an upper half (2) and a lower half (2) made of synthetic resin, such as ABS resin.
3) is obtained by respectively arranging a front cover (8), a slider (9), and a brake body (11) to be described later at predetermined positions.

Here, the lower half (3) will be explained. This lower half (3) is divided into a substantially rectangular flat plate portion where the reel shaft insertion holes (5a) and (5b) are provided, and left and right side walls and rear wall portions excluding the front portion where the front lid (8) is arranged. It consists of a frame part consisting of. In this case, the left and right side walls and the lower surface of the lower half (3) other than the sliding range of the slider (9) are made thicker by the plate thickness of the slider (9), and the slider (9)
Steps are provided on the left and right side walls and the bottom surface of the lower half (3) corresponding to the sliding range of the lower half (3), so that when the slider (9) is placed on the lower half (3), Avoid creating a step between the slider (9) and the slider (9).

A support wall (12) is provided near the front of the left and right side walls with a step inward by the thickness of the arms (8a) and (8b) of the front cover (8), respectively. ) will be described later: A rectangular notch (12a) is provided to form a shaft hole for pivotally supporting the rotating shaft of the front cover (8), and a rectangular notch (12a) is provided at an intermediate position in the vertical direction behind this notch (12a). Notch (
12b), and the lower ends of the arms (8a) and (8b) of the front cover (8) on the rear side cover the support wall (12) when the front cover (8) is rotated upward. That is, a rectangular operator insertion hole (13) is provided near the upper end of the front side of the support wall (12).

In this case, the notches (12a) and (12b) are formed so that when the lower half (3) and the upper half (2) are combined, this support wall (12) and the support wall of the upper half (2), which will be described later, are connected to each other. By abutting against each other, a shaft hole and a through hole for tape end detection are respectively formed.

Furthermore, shielding walls (14a), (14b), and (14c) are provided on the left and right sides of the notch (3a) and on the rear side, respectively, so as to shield the notch (3a) and the inside of the cassette cassette body (1). Eggplant. Further, lateral grooves (15) parallel to the front-rear direction are provided at the upper ends of the left and right side walls, and the lateral grooves (15) are parallel to each other in the front-back direction.
) is provided with a rectangular sliding guide groove (16) corresponding to the sliding range of the slider (9). In this case, the horizontal groove (15
) and the sliding guide groove (16) are shallower than the thickness of the arms (8a) and (8b) of the front cover (8).

Furthermore, (17a) and (17b) are collar portions provided annularly around the pair of reel shaft insertion holes (5a) and (5b).

(18) is a rectangular spring storage part provided in parallel in the front-rear direction at an intermediate position between the reel shaft insertion holes (5a) and (5b);
(19) is a spring locking post installed near the front side of this spring storage part (18), and a tension coil spring for biasing the slider (9), which will be described later, is stored in this spring storage part (18). and one end of this tension coil spring is connected to the spring locking post (19).
is locked.

Next, the upper half (2) will be explained with reference to FIGS. 5 and 6. This upper half (2) is connected to the lower half (3)
), it is composed of a substantially rectangular flat plate portion on which the window plate (2a) is placed, and a frame portion consisting of left and right side walls and a back wall portion excluding the front portion where the front surface M (8) is placed. . In this case, the external dimensions of this upper half (2) should be changed to the lower half (3).
The outer dimensions should be approximately equal to the outer dimensions when the slider (9) is placed on the upper half (2), the lower half (3), and the slider (9) when assembled, so that there is no difference in level between the upper half (2), the lower half (3), and the slider (9). . (20) corresponds to the support wall (12) of the lower half (3), and the front lid (8) is attached to the front side of the left and right side walls, respectively.
This is a support wall provided with a step on the inside corresponding to the thickness of the arm portions (8a) and (8b), and this support wall (20
) and the support wall (12) on the lower half (3) side have complementary shapes. (20a) is this supporting wall (
20) is a through hole for tape end detection provided near the rear upper surface. (21) is an abbreviated transparent transparent plate for tape end detection arranged inside the support wall (20) corresponding to the notch (12b) and through hole (20a) for tape end detection, as shown in FIG. Showing a prism, this prism (21)
An optical path of detection light for tape end detection is formed at .

(14d) shows a shielding wall provided corresponding to the shielding wall (14c) behind the notch (3a) of the lower half (3), and the upper half (2) and lower half (3) are combined. Sometimes the shielding wall (14d) on the upper half (2) side and the lower half (3
) side is butted against the shielding wall (14c) to form a notch (3a).
and the inside of the nine cassette boxes (1) are shielded. (22a)
.

(22b), (22c) and (22d) indicate arc-shaped flanges provided corresponding to the annular flanges (17a) and (17b) of the lower half (3), respectively;
) side flange (22a), (22b) and (22c)
, (22d) and the flange (17a) on the lower half (3) side
and (17b), the reel hubs (4a) and (4b) around which the magnetic tape (6) is wound are loosely fitted so as to be rotatable.

In this case, the collar parts (22a), (22b), (2
The heights of brake body (1) and (22d) will be described later.
The thickness of the brake body (11) is approximately equal to the thickness of the part along this upper half (2) of 1), and the brake body (11) has a thickness of 1.
2b), (22c), and (22d) so as not to protrude further than the reel hubs (4a), (4b) so as not to adversely affect the magnetic tape (6) wound around the reel hubs (4a), (4b). (22e) is the spring locking post (19) of the lower half (3)
This is a U-shaped fixed boss that corresponds to the upper half (
2) and the lower half (3), the spring locking post (19) is located within the opening of this fixed boss (22e),
A spring locking column (19) is located at the end of this fixed boss (22e).
One end of a tension coil spring, which will be described later, is fixed. In addition, (23) is a non-slip uneven part provided near the back side of the left and right side walls, and (24) is a substantially ■-shaped support recess provided at approximately the center of the left and right side walls, respectively. When the tape cassette is loaded into the recording/reproducing apparatus, this support recess (24) is held by support claws from both left and right directions.

Furthermore, the brake body (11) will be explained here.

This brake body (11) is connected to a sliding guide plate (lla) along the inner surface of the upper half (2), and an L-shaped arm (flb) that is vertically installed below both left and right ends of this sliding guide plate (lla). )
and (llc). In this case, the reel hub (4a) and (4b) are placed on the back side of the sliding guide plate (lla).
) corresponding to the brake pawls (lid) and (lie), respectively.
are provided respectively. Furthermore, this brake claw (lid), (
reel hub (4a), (4b) corresponding to
A ratchet wheel is provided on the outer periphery of the upper half (2).

In addition, a spring locking portion (lla) is provided at the center of the sliding guide plate (lla).
f), and manipulators (l1g) and (llh) are provided at the ends of the arms (llb) and (llc), respectively.

In this case, the brake body (11) is attached to the spring locking part (llf).
The biasing spring (25) is locked so that the free end of this spring (25) presses the shielding wall (14d) of the upper half (2), and the biasing force of this spring (25) is used to apply the brake. nail(
lid).

(lie) is caught on the pawl wheels of the reel hubs (4a) and (4b), and the reel hubs (4a) and (4b) are locked so that they cannot rotate. Also, the brake body (11
) is placed in the cassette case (1), the operator (l)
1g) and (llb) protrude a predetermined amount to the outside of the support wall (12) through the operator hole (13) of the lower half (3), and the front surface M (8) When rotated in the direction, this protruding control element (l1g), (ll
b) is the arm part (8a) of the front cover (8).

(8h), the brake body (11) is slid forward against the biasing force of the spring (25), and the brake pawl (lid) (lie) (lie) is pressed by the end of the reel hub (
4a), (4b), move away from the pawl wheel, and move the reel hub (
4a) and (4b) are made rotatable.

Furthermore, the front cover (8) will be explained here. A plate part (8c) for closing the front part of the cassette case (1) with this front cover (8), and arm parts (8a) provided at both left and right ends of this plate part (8c) so as to face each other. and (8b) to form a substantially U-shape. In this case, when the front cover (8) is rotated to the position where the front part is closed, the front cover (8)
The arms (8a) and (8b) of the upper half (2) are made to cover the left and right support walls (12) of the upper half (2), and when the front cover (8) is at the 20-turn position, the slider (9) (8
a) and (8b), and a rotating wheel (8d) is provided at a substantially central position inside the arm portions (8a) and (8b). (8e) and (8f
) are U-shaped cut-out portions in the plate portion (8c) corresponding to both left and right sides of the cut-out portion (3a) of the lower half (3).

Further, the slider (9) will now be explained with reference to FIGS. 5 and 8. This slider (9) is connected to a flat plate part (9c) along the lower surface of the lower half (3) and a side plate part (9c) located at both left and right ends of the flat plate part (9c) and along the left and right side walls of the lower half (3). 9d) and (9e) are formed into a substantially U-shape when viewed from the front and rear directions. (9f) and (9g)
(9f) and (9g
) is located in the lateral groove (15) as shown in FIG. 8 when the slider (9) is placed in the cassette case (1). or,
Squeezed portions (26) protruding toward the cassette case (1) are provided at predetermined positions on the left and right side plates (9d) and (9e) corresponding to the sliding guide groove (16) of the lower half (3). The cassette case (1) side of this constricted portion (26) is formed into a smooth curved surface so that the contact angle with the sliding guide groove (16) is an obtuse angle as shown in FIG. ) is in contact with the bottom of the slide guide groove (16), causing the slider (
The slider (9) is positioned so that the cassette case (1) (9) is positioned in the left-right direction, and the slider (9) is ) to position the cassette case (1) in the upper direction, and (27) is a flat plate part (9c).
A protrusion is provided parallel to the front-rear direction near both left and right sides of the cassette case, and the protrusion (27) and the constriction part (26) come into sliding contact with the cassette case (1).

(9h) is a spring locking piece provided corresponding to the spring storage part (18) of the lower half (3), and (28) is a tension coil spring for biasing the slider (9).
) by locking one end with the spring locking post (29) of the lower half (3) and locking the other end with this spring locking piece (9h), the slider (9) locks the notch (3a). Forced forward to close. (9i) and (9j) are the front lid (
This is an abutment piece that is vertically provided at the front end of the flat plate part (9C) corresponding to the cutouts (8e) and (8f) of 8).

The operation of the tape cassette constructed in this way will be explained with reference to FIGS. 9 to 12.

First, during storage, the front part of the cassette case (1) is closed by the front cover (8) as shown in FIG. 9 and FIG. be slid forward. At this time, the brake body (11) is biased backward by the spring (25), and the brake claws (lid) and (lie) are pressed against the reel hub (4a).
) and (4b), and the reel hub (4a
) and (4b) are locked so that they cannot be rotated.

Also, the reel shaft insertion hole (5a) of the cassette case (1),
(5b) and the reel shaft insertion hole (9) of the slider (9).
a) and (9b) are rendered incompatible, and the notch (3a) of the cassette casing (1) is closed by the slider (9), causing dust to enter the reel shaft insertion hole (5a), (
5b) and the notch (3a), and the magnetic tape (6) can be sealed well without the fingers or the like touching the magnetic tape (6). Furthermore, the side plates (9d) and (9e) of the slider (9) are connected to the front cover (8).
) is located below the arms (8a) and (8b) of
The upper end surfaces of the side plates (9d) and (9e) of the slider (9) and the lower end surfaces of the arm sections (8a) and (8b) of the front cover (8) collide, causing the front cover (8) to rotate. The front lid (
8) will not rotate inadvertently. Therefore, during storage, the front cover (8) may inadvertently rotate and the magnetic tape (6) may be exposed on the front surface of the cassette case (1).
) can be prevented from touching with fingers, etc.

Next, during use, the tape cassette is loaded into the recording/reproducing device. In other words, when inserting a tape cassette into a recording/playback device, the fixing claw on the side of the recording/playback device will touch the front cover (8).
) contact the abutment pieces (9i) and (9j) of the slider (9) through the cutouts (8e) and (8f), and in this state, the tape cassette is further inserted to a predetermined position in the recording/reproducing device. As a result, while the slider (9) is fixed by the fixed claw, the cassette case (1) side is moved against the biasing force of the tension coil spring (28), and is moved relative to the cassette case (1). The slider (9) is slid backwards. In this case, the sliding guide groove (16) of the cassette case (1)
Since the aperture part (26) having a smooth curved surface is in sliding contact with )
will not be scratched or scraped. Moreover, since the slider (9) is supported so as to be able to slide with respect to the cassette case (1) by the constriction part (26) and the protruding part (27), the cassette case (1) and the slider (9) are supported so that they can slide. ) is relatively small, and the sliding resistance of the slider (9) with respect to the cassette case ( ) can be reduced accordingly.

By sliding the slider (9) backward in this manner, the notch (3a) and the positioning hole (10a), (
10b) is opened, and the reel shaft insertion holes (9a), (9b) of the slider (9) and the cassette case (1) are opened.
The reel shaft insertion holes (5a) and (5b) are made to correspond, and the reel shaft insertion holes (5a) and (5b) are opened. Then, from this state, the front cover (8) is rotated upward by the cover opening member of the recording/reproducing apparatus, resulting in the state shown in FIGS. 11 and 12. In this case, the front M
When (8) is rotated upward, the arm part (8a),
The operator (l) of the brake body (11) is inserted from the lower end of (8b).
1g), (llb) are pushed forward, and the brake body (
11) is slid forward against the biasing force of the spring (25). At this time, the brake pawl (li) of the brake body (11)
d), (lie) and reel hub (4a), (4
b) The connection with the pawl wheel is released and the reel hub (4a)
, (4b) are made rotatable.

In such a state, the positioning hole (LOA), (1
The positioning bin and reel shaft are inserted into the reel shaft insertion holes (5a) and (5b), respectively, and the magnetic tape (6) is exposed on the front surface of the cassette case (]), and the notch (3a) is inserted into the reel shaft insertion hole (5b). ) A guide system is inserted into the magnetic tape (6), and the magnetic tape (6) is pulled forward and loaded by this guide system, and predetermined recording or reproduction is performed.

It should be noted that, as described above, when the process is performed from the time of use to the time of storage, the operation opposite to that described above is performed when the process is performed from the time of use to the time of storage.

[Problem to be solved by the invention]

In the conventional tape cassette constructed as described above, the window plate (2a) and the prism (21) are separately molded from transparent resin on the upper half (2) made from opaque resin, and these are glued together during assembly. Upper half (2)
I was trying to assemble it.

For this reason, conventionally, many manufacturing processes were required, especially for prisms (2
Since 1) is a very small part, it is a very difficult task to attach this small prism (21) to the inside of the left and right support walls (20) corresponding to the through hole (20a) for tape end detection. This results in high costs.

The present invention has been made in view of the above, and an object of the present invention is to provide an inexpensive tape cassette with fewer manufacturing steps.

[Means to solve the problem]

In order to achieve the above-mentioned object, the present invention includes a reel hub for winding a tape that is housed in a cassette case, a window plate (2a) that allows the inside of the cassette case to be seen through, and a prism as a transparent member for detection. In a tape cassette in which (21) is provided at a predetermined position inside the cassette case, the window plate (2a') and the prism (21' ) are formed together (by integral two-color molding).

[Effect]

By integrally molding the window plate (2a') and prism (21') for the upper half (2) using a two-color molding method, it is possible to create a separate window plate for the upper half during manufacturing, unlike conventional methods. There is no need to assemble the prism, reducing the manufacturing process.
This makes it possible to significantly reduce costs.

〔Example〕

Hereinafter, one embodiment of the tape cassette of the present invention will be described with reference to FIGS. 1 and 2.

In this example, as shown in FIG. 2, the window plate (2a') and the prism (21') are integrally formed using a transparent synthetic resin, such as acrylic, via the connecting portion (29a), and the integrated transparent member ( 29) and eggplant.

This integrated transparent member (29) is formed integrally with the upper half (2) during manufacturing. In other words, during injection molding, the
As shown in the figure, the first lower mold (30) and the upper mold (31)
After injection molding the upper half (2) by injecting molten opaque resin into the cavity (32) forming the upper half (2) through the gate (31a), the first lower mold ( 30) and remove the upper mold (3) as shown in Figure B.
1) and the formed upper half (2) with a second lower mold (
33), and the second lower mold (33), upper mold (31), and upper half (2) are combined to form an integrated transparent member (2).
A molten transparent resin is injected into the cavity (34) forming the cavity (34) through the gate (31b) to form an integrated transparent member (29). In this case, when the molten transparent resin is injected into the cavity (34), the heat and injection pressure of the molten transparent resin cause the molten transparent resin to be removed from the upper half (2), which has already solidified. The contact point with the resin becomes semi-molten, and the upper half (2) in this semi-molten state solidifies again and the transparent resin solidifies, thereby forming an integrated transparent member ( 29) is formed integrally with the upper half (2) (two-color molding method).

According to this embodiment, the integrated transparent member (29
) and the upper half (2) are integrally formed,
It is no longer necessary to assemble the separate window plate (2a) and prism (21) to the upper half (2) by adhesive or the like as in the past, which simplifies the manufacturing process and reduces the number of parts. Therefore, parts management becomes easier, and as a result, there is the benefit of being able to achieve significant cost reductions.

In the above embodiment, the tape end detection prism (21') was described as a transparent member for detection, but other transparent members for detecting the type of tape etc. can also have the same effect as in the above embodiment. It's easy to see what you can get. Furthermore, it goes without saying that the present invention is not limited to the above-described embodiments, and can take various other configurations without departing from the gist of the present invention.

〔Effect of the invention〕

As described above, in the tape cassette of the present invention, the upper half is molded from opaque resin, and the window plate and detection member are integrally formed from transparent resin using a two-color molding method.
The manufacturing process is simplified and the cost can be significantly reduced, so that an inexpensive tape cassette can be provided.

[Brief explanation of the drawing]

1 and 2 show an embodiment of the present invention, FIGS. 1A and 2B are explanatory views of the two-color molding method, and FIG. 2 is a perspective view of the upper half. 3 to 12 are views for explaining conventional examples. FIG. 3 is a perspective view showing an example of a tape cassette having a rotatable front cover and a slidable slider, and FIG. FIG. 5 is an exploded perspective view of FIG. 3; FIG. 5 is an exploded perspective view of FIG. 3;
6 is a perspective view showing the inside of the upper half of FIG. 5, FIG. 7 is a sectional view for explaining the prism in FIG. 5, FIG. 8 is a diagram for explaining the slider in FIG. 5, and FIG. The figure is a perspective view showing the state in storage of Fig. 5, Fig. 1O is a route map for explaining Fig. 9, Fig. 11 is a perspective view showing the state in use of Fig. 5, and Fig. 12 is a perspective view showing the state in use of Fig. 12 is a route map for explaining FIG. 11. FIG. In the figure, (1) is the cassette case, (2) is the upper half, and (2) is the cassette case.
a) and (2a') are window plates, and (21) and (21') are prisms as transparent members for detection. 2...-1 bar 2 2d--% root 21'... Ass.29.

Claims (1)

[Scope of Claims] A reel hub for winding a tape is housed in a cassette casing, and a window plate and a transparent member for detection are provided at predetermined positions of the cassette casing, respectively, to enable the inside of the cassette casing to be seen through. In the tape cassette, the upper half is molded from an opaque resin, and the window plate and the detection member are integrally molded in two colors from a transparent resin.