JPH0413799Y2 - - Google Patents

Description

[Detailed description of the invention] Industrial application field The present invention relates to tape cassettes, and in particular, a prism is provided at a predetermined position within the casing, and the light guided by the prism is used to detect the end of the tape. The present invention relates to a tape cassette which performs the following operations.

〓Summary of the invention〓 The present invention forms a prism for optically detecting the end of the tape separately from the casing, and provides extensions on both sides of one end in the optical axis direction. The prism is fixed to the casing by the protrusion, and the prism is fixed stably and in the correct posture.

〓Prior Art〓 It has been conventionally practiced to optically detect the tape end of a tape cassette. This method detects the tape end by utilizing the optical difference between an opaque magnetic tape and a transparent leader tape connected to the end of the magnetic tape. When detecting such a tape end, it is necessary to guide light across the magnetic tape, and for this purpose, as disclosed in Japanese Patent Laid-Open No. 59-20179, the running path of the magnetic tape is A prism is placed inside the cassette casing to guide light across the cassette.

Problems to be Solved by the Invention When the prism used for optical tape end detection is provided separately from the cassette casing, the installation area of the prism relative to the cassette casing is small. Therefore, it becomes very difficult to install the prism in the correct orientation.
Furthermore, in terms of mounting strength, the prism is likely to fall in the lateral direction. If the prism is not installed correctly, it will not be able to guide light accurately, resulting in incorrect tape end detection and malfunction.

The present invention was devised in view of these problems, and is designed to ensure that the prism, which is separate from the cassette casing, is installed at a predetermined position within the casing, and is also placed in the correct orientation. The purpose of this invention is to provide a tape cassette.

〓Means for solving the problem〓 The present invention has an L
In a tape cassette in which a letter-shaped prism is attached and the tape end is detected using the light guided by the prism, a tape cassette is provided on both sides of one end in the optical axis direction of the prism, which intersects with the optical axis direction. The prism is integrally provided with extending portions extending in the direction, and the prism is welded and fixed to the casing by means of these extending portions.

〓Effect〓 Therefore, according to the present invention, extending portions extending to cross the optical axis direction are used on both sides of one end portion of the prism in the optical axis direction, and the prism is controlled by these extending portions. By welding to the casing, the prism is fixed to the cassette casing.

〓Example〓 The present invention will be described below with reference to an illustrated example.
Figures 4 to 6 are PCMs according to an embodiment of the present invention.
This shows an audio tape cassette, and this tape cassette consists of cassette casing 1.
It is equipped with 0. The cassette casing 10 is composed of an upper shell 11 and a lower shell 12, and by combining these, a flat rectangular parallelepiped-shaped cassette casing 10 is assembled. A pair of reels 13 are disposed within the casing 10, and a magnetic tape 14 is wound around these reels 13 with both ends fixedly attached. Magnetic tape 14 is Loisiel 1
The tape is guided by a pair of tape guides 15 formed in the lower shell 12, and is stretched across the bottom opening 16 formed by the notch also formed in the lower shell 12 and the front side opening formed by this bottom opening. Become.

A cassette lid 17 is attached to the front side of the casing 10 consisting of the pair of shells 11 and 12, and the cassette lid 17 covers the opening on the front side of the casing and also covers a pair of tapes. The magnetic tape 14, which is guided and wrapped around the guide 15, is protected. The cassette lid 17 is provided with pins 18 at both ends thereof, and the pins 18 are received in step portions 19 formed on both sides of the lower shell 12, so that the cassette lid 17 is rotatably supported by the casing 10. .

A reel brake 20 is disposed below the top shell 11 of the casing 10, and this brake 20 is connected to a brake spring 21.
The brake piece 22 contacts the reel 13 and performs braking.
The reel brake 20 has protrusions 23 on both ends.
As shown in Figure 5, the cassette lid 1
7 is opened, the reel brake 20 moves forward by the protruding piece 23, and the brake piece 22
is separated from the reel 13, and the brake is released.

A slide plate 24 is slidably attached to the lower side of the lower shell 12 constituting the cassette casing 10, and engaging portions 25 formed on both sides of the slide plate 24 engage the cassette casing 10. It is engaged with engagement grooves 26 formed on both sides of. The slide plate 24 is biased by a spring so as to close the bottom opening 16 of the lower shell 12. That is, a spring hook 27 is provided at the front end of the slide plate 24, and the tip of a spring 28 is locked to this spring hook 27.

The slide plate 24, which is biased in the closing direction by the spring 28, is locked when the bottom opening 16 is opened and closed. That is, as shown in FIG. 6, a slit 2 is provided on one side of the lower shell 12.
A lock lever 30 is formed in a part of the lower shell 12 by this slit 29. The lower surface of the distal end side of the lock lever 30 is constituted by a lock portion 31 consisting of a protrusion.
This lock portion 31 is connected to the engagement hole 3 of the slide plate 24.
2 and 33.

Furthermore, this tape cassette has a prism 3 inside the casing 10 for detecting the end of the tape.
5. To explain this structure with reference to FIGS. 1 to 3, the prism 35
is integrally molded from transparent synthetic resin and includes a horizontal portion 36 and a vertical portion 37. Furthermore, inclined surfaces 38 constituting reflective surfaces are provided above and below the vertical portion 37. Furthermore, protective ribs 3 are provided at the edges of the light incident surface, light exit surface, and reflection surface of the prism 35, respectively.
9 is formed. Such a protective rib 39
This is to prevent damage to the surface through which light is transmitted or reflected, and to ensure that the tape end is always detected accurately.

Furthermore, this prism 35 is shown in FIGS.
As shown in the figure, extension parts 40 extending in a direction intersecting the optical axis direction on both sides of one end in the optical axis direction.
It is equipped with The extending portion 40 is configured in a plate shape and is provided with a notch 41 . A protrusion 42 protruding from the inner surface of the top shell 11 constituting the cassette casing 10 is received in this notch 41, and the upper end of the protrusion 42 is crushed by welding.
5 is fixed to the inner surface of Atupashiel 11.

In the above configuration, when this tape cassette is installed in a tape player, the cassette lid 17 on the front side is opened, as shown in FIG. The magnetic tape 14 stretched between the pair of tape guides 15 is exposed. At the same time, by opening the cassette lid 17, the protruding piece 23 of the reel brake 20 is pushed forward, the brake piece 22 is separated from the reel 13, and the reel brake is released. Further, as the tape cassette is mounted on the tape player, the slide plate 24 moves backward against the spring 28, and the bottom opening 16 formed in the lower shell 12 is opened.

Therefore, the tape pull-out means is inserted into the area between the pair of tape guides 15 from the bottom opening 16, and the tape pull-out means moves forward to pull out the magnetic tape 14 between the tape guides 15. It is then wrapped around the rotating head drum of the tape player. In this state, as the magnetic head rotates, the magnetic tape 14 runs so as to be fed out from one reel 13 and wound onto the other reel 13, thereby performing high-density recording and/or reproduction. You will be able to do it.

Furthermore, this tape cassette is equipped with a prism 35 as described above. As shown in FIG. 3, the prism 35 is fixed to the lower surface of the upper shell 11 constituting the cassette casing 10. As shown in FIG. Light 43 incident through the window 44 of the casing 10 is guided to the horizontal portion 36 of this prism 35, reflected by the upper inclined surface 38, and is reflected by the vertical portion 37.
and is further reflected by the lower inclined surface 38. The reflected light is then emitted from the back side of the vertical portion 37 of this prism 35, and is emitted from the magnetic tape 1.
It is designed to intersect with the road No. 4. Therefore, if an opaque magnetic tape 14 is present at this location, light 43 is blocked. On the other hand, if a transparent leader tape is present at the running position of the magnetic tape 14, the light passes through the leader tape and exits the casing 10 through the lower window 44. Therefore, by utilizing such blocking and transmission of the light 43, it is possible to detect the end of the tape.

As shown in FIGS. 1 and 2, this prism 35 is fixed to the atsushiel 11 by extensions 41 formed on both sides of one end in the optical axis direction. That is, the protrusion 42 of the atsushiel 11 is received in the notch 41, and the top of the protrusion 42 is crushed by welding to fix the extension part 40. Therefore, with such a configuration, the prism 35 can be reliably attached to the casing 10. Moreover, since the prism 35 is fixed by the extending portions 40 extending on both sides of one end in the optical axis direction, the prism 35 does not wobble from side to side in FIG. Since it is held in the casing 10 in the correct posture, it becomes possible to accurately detect the tape end.
Furthermore, since this prism 35 is provided with protective ribs 39 at the edges of its light incident surface, reflective surface, and light exit surface, it is possible to prevent these surfaces from being damaged.

Next, a modification of the above embodiment is shown in FIGS. 7 and 8.
This will be explained with reference to the diagram. In this modification, the extending portions 40 formed on both sides of one end in the optical axis direction of the prism 35 are arranged so as to be inserted between the pair of regulating protrusions 46, and the extending portions 40 are The lower surface is brought into contact with a welding rib 47 formed on the inner surface of the atsupashiel 11. In this state, the horn 48 for ultrasonic welding is lowered from the top as shown in FIG.
8 applies ultrasonic vibration, and the welding rib 47 and the extension part 40 are coupled by ultrasonic welding. Note that the prism 35 is attached to the horn 48.
An escape recess 49 that escapes the horizontal portion 36 is formed.

Even in this modified example, since the prism 35 is fixed to the atsushiel 11 by the extending portions 40 that protrude on both sides in the width direction, it is possible to securely fix the prism 35. Not only is this possible, but it also becomes possible to attach the prism 35 to the cassette casing 10 in the correct orientation, similar to the above embodiment. Therefore, even with this modification, the tape end can be detected correctly.

Next, another modification of the above modification will be explained with reference to FIGS. 9 and 10. In this modification, the extending portions 40 formed on both sides of one end in the optical axis direction of the prism 35 are formed to be a plane continuous with the upper surface of the horizontal portion 36. Then, as shown in FIG. 10, the horizontal portion 36 of the prism 35, which is formed to protrude downward, is inserted between a pair of regulating ridges 46, and these regulating ridges 46 A welding rib 47 formed on the upper surface of the welding member is brought into contact with the extension portion 40, and ultrasonic vibrations are applied by a horn 48 mounted from above. Therefore, in this modification as well, as in the above embodiment, the prism 35 can be properly fixed and its posture can be maintained stably.

Effects of the invention As described above, the present invention integrally provides detection parts extending in a direction intersecting the optical axis direction on both sides of one end of the prism in the optical axis direction, and detects The prism is fixed to the casing by welding. Therefore, according to the present invention, it is possible to securely fix the prism to the casing in the correct posture, and by using such a prism, it is possible to correctly guide light and accurately detect the tape end. .

[Brief explanation of drawings]

Fig. 1 is an exploded perspective view showing the installed state of a prism according to an embodiment of the present invention, Fig. 2 is a front view of the same installed state, and Fig. 3 is an optical tape end detection operation using a prism. FIG. 4 is an external perspective view of the tape cassette, FIG. 5 is an external perspective view of the tape cassette with the lid open, FIG. 6 is an exploded perspective view of the tape cassette, and FIG. 7 is an exploded perspective view showing the installation of a prism according to a modification, FIG. 8 is a longitudinal sectional view of the same, FIG. 9 is an exploded perspective view showing the installation of a prism according to another modification, and FIG.
The figure is a longitudinal sectional view of the same. In addition, in the codes used in the drawings, 10...Cassette casing, 11...Atsupashiel, 14...
...Magnetic tape, 35... Prism, 40... Extension, 41... Notch, 42... Protrusion, 43...
Light, 46...Regulation protrusion, 47...Welding rib,
It is.

Claims (1)

[Claims for Utility Model Registration] A tape cassette in which a substantially L-shaped prism is installed at a predetermined position within the casing, and the tape end is detected using light guided by the prism, as described above. Extending portions extending in a direction intersecting the optical axis direction are integrally provided on both sides of one end portion in the optical axis direction of the prism, and the prism is welded and fixed to the casing by these extending portions. A tape cassette with this feature.