JPH0477395B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to detecting the end of a tape by optically detecting a leader tape provided at the end of a tape body housed in a tape cassette. The present invention relates to a tape cassette with a tape end detection device that makes it possible to detect the end of a tape.

[Prior Art] Conventionally, a transparent leader tape having optical transparency is provided at an end in the running direction of a magnetic tape housed in a tape cassette. This leader tape is made of a material that is mechanically stronger than the magnetic tape. And the magnetic tape
The leader tape is clamped to a reel hub rotatably supported within the cassette half and housed within the cassette half.

Focusing on the fact that a transparent leader tape is provided at the end of the magnetic tape, the end of the magnetic tape is detected by detecting this leader tape using an optical detection means. Detection devices have been used in the past. This conventionally used tape end detection device connects a light emitting element such as an LED to a light emitting device, which is placed across the running path of the magnetic tape inside the cassette half or the running path of the magnetic tape pulled out from the cassette half and running. It is composed of a light receiving element that receives light from the element. That is, the above light emitting element is
When the tape cassette is installed in a tape recorder, it is placed in a position where it can be inserted into a light emitting element storage portion formed in the cassette half at a position opposite to one side of the tape running path in the cassette half. On the other hand, the light-receiving element is provided at a position facing a through hole formed in the side surface of the cassette half facing the tape running path within the cassette half, or at a position facing the magnetic tape that is pulled out from the cassette half and runs.

The leader tape is detected by using a light receiving element to detect the light transmitted from the light emitting element when the leader tape passes through the optical path from the light emitting element to the light receiving element. The tape end is detected.

[Problem that the invention seeks to solve]

However, in the above-mentioned tape end detection device, it is necessary to provide a light emitting element storage section within the cassette half, making it difficult to further reduce the size of the tape cassette while improving the magnetic tape storage density. ing.

In addition, in order to make the light emitting element face into the tape cassette, it is necessary to erect a support pillar on the tape cassette placement surface of the recording and reproducing apparatus and install the light emitting element through this support pillar. This has become a problem when trying to miniaturize the device.

Furthermore, since the light-emitting element is located inside the tape cassette and the light-receiving element is located outside the tape cassette, the electrical connection wires drawn out from the light-emitting element and the light-receiving element become long.
The mounting space for the light-emitting element and the light-receiving element becomes large, which poses a problem in reducing the size of a recording/reproducing apparatus in which this leader tape detection device is installed.

SUMMARY OF THE INVENTION Therefore, the present invention aims to solve the above-mentioned problems, and provides a tape cassette that can be further miniaturized while improving the storage density of magnetic tapes, and which also enables further miniaturization of recording and reproducing devices. It was proposed for the purpose of providing a cassette.

[Means for solving problems]

The present invention solves the problems of the conventional methods as described above, and in order to achieve the above objects,
A light guide is provided that guides light from the lower edge of the tape body in the tape running path in the cassette half to a position facing at least a part of the plane of the tape body, and the light guide A first reflecting section that reflects the light at right angles, and a second reflecting section that is provided opposite to the first reflecting section and further reflects the light reflected by the first reflecting section at right angles, The optical path of the light incident on the light guide is U-shaped,
In addition, the second reflecting section is positioned so as to face at least a part of the plane of the tape body on the tape running path.

[Effect]

In the tape cassette according to the present invention, when light is incident on the light guide, the light is reflected at a right angle by the first reflecting part, and then further reflected at right angles by the second reflecting part. , and are led out to the outside through a U-shaped optical path, across the tape running path inside the cassette half.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

A tape cassette with a tape end detection device according to the present invention, as shown in FIGS. 1 and 2,
A pair of tape reels (not shown) are rotatably supported in a cassette half 4 formed by butting together a pair of upper and lower halves 2 and 3, and a tape body 5 is wound and stored between these tape reels. .
This tape body 5 is composed of a magnetic tape 5a and a transparent leader tape 5b having a predetermined length and having optical transparency connected to the fixed end of the tape reel which is the longitudinal end of the magnetic tape 5a.

The cassette half 4 in which the tape body 5 is wound and stored is made of opaque synthetic resin that does not have light transmittance, and has openings on both sides of the front side through which the tape body 5 is drawn out. Sections 6 and 7 are provided. The tape body 5 is pulled out from the openings 6 and 7, extends to the front side of the cassette half 4, and runs from one tape reel to the other tape reel. Also,
On the front side of the cassette half 4, there is a recess 8 into which a loading mechanism, etc., which hooks the tape body 5 extending on the front side of the cassette half 4 and loads it onto a predetermined tape running path in the recording/reproducing apparatus, enters. It is provided. Furthermore, a front cover 9 is rotatably attached to the front side of the cassette half 4 to cover and protect the tape body 5 extending to the front side. This front cover 9 is constructed by engaging rotating pins 10 protruding from the inner surfaces of rotating pieces 9b, 9b provided on both sides of the lid portion 9a into engagement holes 11 formed on both sides of the cassette half 4. It is rotatably mounted. When the front side of the cassette half 4 is closed, the front cover 9 is locked by a locking mechanism (not shown) to prevent the cover from being opened inadvertently.

By the way, in the vicinity of each opening 6, 7 of the cassette half 4, at a position covered by the rotating pieces 9b, 9b of the front cover 9, there is a light guide 12 made of a transparent synthetic resin having light transmittance. 12 are provided so as to be buried respectively. These light guides 12,1
2 is formed in a substantially L-shape and is provided extending from the bottom side of the lower half 3 to the inner side surface of the cassette half 4 of each of the openings 6 and 7. That is, the light guide 12, as shown in FIGS. 1 and 2,
It is provided from the lower edge of the tape body 5 in the tape running path of the openings 6 and 7 to a position facing the plane of the tape body 5. A horizontal portion 12 extending on the bottom surface of the lower half 3 of the light guide 12 is provided.
As shown in FIG. 2, one end of a is fitted into a notched recess 13 formed by cutting out the side surface of the lower half 5, and its end face is exposed to the outside of the cassette half 4. Further, as shown in FIG. 3, the horizontal part 12a of the light guide 12 and the vertical part 12b rising on the inner side surfaces of the openings 6 and 7 intersect with each other on the outer surface of the bent part. A first reflecting surface 14 is provided which has an inclination angle of 45 degrees to reflect the light transmitted through the portion 12a at right angles and guide it to the vertical portion 12b. Further, a tip of the vertical portion 12b is provided with a second reflective surface that faces the first reflective surface 14 and reflects the light passing through the vertical portion 12b at a right angle toward the outside of the cassette half 4. 2
A reflective surface 15 is provided. By forming the light guide 12 in this way, the light guide 12 passes from the horizontal part 12a to the vertical part 12b, intersects with the tape body 5 on the tape running path in the openings 6 and 7, and goes to the outside of the cassette half 4. A U-shaped optical path 1 is formed.

Note that the first reflective surface 14 is formed on the cassette half 4
Since it faces the recess 8, there is a risk that the loading mechanism etc. may come into contact with it. Therefore, in order to prevent damage from these loading mechanisms and the like, a protective film 16 is formed on the outer surface.

The end surface of the horizontal portion 12a fitted into the notched recess 13 of the lower half 3 of the light guide 12 faces the side surface of the cassette half 4 and serves as a light introducing portion 17. In addition, the light guide 12 of the cassette half 4
The second reflective surface 1 provided at the end of the vertical portion 12b of
A light transmission opening is formed on the side surface facing 5 in parallel with the horizontal portion 12a, and this opening serves as a light guide portion 18.

On the other hand, on the side of the recording/reproducing apparatus into which the tape cassette 1 is installed, a light emitting element 20 consisting of an infrared light emitting element or the like is provided facing the light introducing section 17 of the installed tape cassette 1, and A light receiving element 21 made of an infrared detecting element or the like is provided opposite to the portion 18 . In this way, the light emitting element 20
By providing the light receiving element 21, the light emitted from the light emitting element 20 is transmitted to the tape cassette 1.
The light passes through the optical path 1 formed by the light guide 12 and is detected by the light receiving element 21.

Then, the tape body 5 in the tape cassette 1 travels in the forward direction of arrow A in FIG. Then, the transparent leader tape 5b provided at one end of the tape body 5 reaches the tape running path corresponding to the light guide 12 provided near one opening 6 of the cassette half 4. In this way, the light guide 12
When the leader tape 5b reaches the tape running path corresponding to the opaque magnetic tape 5a, the light from the light emitting element 20 that has been blocked by the opaque magnetic tape 5a passes through the leader tape 5b and intersects with the leader tape 5b. The light passes through the optical path 1 and is detected by the light receiving element 21. By detecting the light from the light emitting element 20 by the light receiving element 21, the leader tape 5b at the end of the tape body 5 is detected, and one tape end of the tape body 5 is detected.

Also, the tape body 5 in the tape cassette 1 travels in the opposite direction to the direction of arrow B in FIG. Then, the leader tape 5b provided at the other end of the tape body 5 reaches the tape running path corresponding to the light guide 12 provided near the other opening 7 of the cassette half 4, and the same process as described above is carried out. The light from the light emitting element 20 is detected by the light receiving element 21, the leader tape 5b at the end of the tape body 5 is detected, and the other tape end of the tape body 5 is detected.

Note that the leader tapes 5b provided at each end of the tape body 5 are connected to the respective light guides 12, provided on both sides of the cassette half 4, when the tape body 5 is wound onto one or the other tape reel. The length does not exceed 12.

In the above embodiment, the cassette half 4 is made of a material that does not transmit light, and a part of the cassette half 4 is used to constitute the second reflective surface 15. In the case where the light guide 12 is made of a material having light transmittance, the light guide 12
The second reflective surface 15 may be constructed by forming a light reflective film on the surface.

Furthermore, the light guide 12 faces the plane of the tape body 5 from the lower end side of the tape body 5 located in the tape running path in the tape half 4 along which the tape body 5 unreeled from the tape reel runs, and is connected to the tape running path. A light introduction section 17 and a light guide section 18 form intersecting optical paths and are opposed to the light emitting element 20 and the light emitting element 21 provided outside the cassette half 4, respectively.
It is not necessary to provide the tape in the vicinity of the openings 6 and 7 of the cassette half 4 as long as the tape can be configured to have a tape running path within the cassette half 4. .

〔Effect of the invention〕

As described above, the present invention provides a light guide in a part of the cassette half, forms an optical path that intersects the tape body on the tape running path inside the cassette half through the light guide, and extends the tape outside the tape cassette. Since the leader tape can be detected by a light emitting element and a photodetecting element placed on one side, it is necessary to provide a part in the tape cassette for positioning the light emitting element, etc., which reduces the storage density of the magnetic tape. Further miniaturization of the tape cassette can be achieved while improving the tape cassette.

Furthermore, since the light-emitting element and the light-detecting element can be located outside the tape cassette, there is no need to route wires connecting the light-emitting element and the light-detecting element, and the light-emitting element can be placed inside the tape cassette. Since there is no need for supporting columns or the like, the installation space for configuring the leader tape detection device can be reduced, and the recording/reproducing device itself can be downsized.

[Brief explanation of the drawing]

FIG. 1 is a schematic perspective view showing a tape cassette with a leader tape detection device according to the present invention;
The figure is a perspective view of a main part of the tape cassette, and FIG. 3 is a sectional view of a main part showing a light guide and an optical path formed by the light guide. 1... Tape cassette, 4... Cassette half, 5... Tape body, 5a... Magnetic tape, 5b
... Leader tape, 12 ... Light guide, 14 ... First
reflective surface, 15... second reflective surface, 17... light introducing section, 18... light guiding section.

Claims (1)

[Claims] 1. In a tape cassette which stores a tape body in which a light-transmitting leader tape is provided at at least one end in the running direction of the recording tape in the cassette half, the tape body located under the tape running path in the cassette half is A light guide that guides light from the side edge side to a position opposing at least a part of the plane of the tape body is provided, and the light guide includes a first reflecting portion that reflects the light at right angles; a second reflecting section that is provided opposite to the first reflecting section and further reflects the light reflected by the first reflecting section at right angles;
a reflecting part, the optical path of the light incident on the light guide is U-shaped, and the second reflecting part is arranged to face at least a part of the plane of the tape body in the tape running path. A tape cassette with a tape end detection device located at the end of the tape.