JPH04313837A - Detector on beginning/end of magnetic tape - Google Patents

Abstract

PURPOSE:To detect the beginning and/or the end of a magnetic tape wound around one pair of reels by using an optical signal giving and receiving means consisting of one set of light emitting element and a light receiving element. CONSTITUTION:A hub part 6a of a supply reel 6 is formed with a material for transmitting light emitted from the light emitting element 40, and moreover, the supply reel 6 is rotatively supported by fitting a rotary driving body 30 into a hole 6a1 of an inner circumferential part of the hub part 6a. A reel engagement member 35 of the rotary driving body 30 is formed with a reflecting surface 35b, providing a function of changing directions of an optical path of the light from the light emitting element 40. Then, the light emitting element 40 is arranged outside flange parts 6b and 6c of the supply reel 6, while the light receiving element 41 is fixed to a chassis 21 fitted with the rotary driving body 30. Then, when the magnetic tape is not wound around the hub part 6a, the light from the light emitting element 40 is transmitted through the hub part 6a and received by the light receiving element 41 via the reflecting surface 35b of the reel engagement member 35.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention is directed to detecting the starting end and/or the ending end of a magnetic tape wound on a pair of reels using an optical signal transmitting/receiving means including a light emitting element and a light receiving element. -Relates to termination detection device.

0002

[Prior Art] Video tape recorder (VTR),
2. Description of the Related Art There is a conventional magnetic tape start/end detection device employed in a digital audio tape recorder (DAT) as shown in FIG.

This magnetic tape start/end detection device 10
0, the tape cassette 101 is in the upper and lower halves 101a.
, 101b (only the lower half 101b is shown) are assembled into a box shape, and a magnetic tape 104 is wound around a supply reel 102 and a take-up reel 103 mounted inside this tape cassette 101. Further, a transparent leader tape 105 is connected to the starting end and the ending end of the magnetic tape 104, that is, to the starting end side of the magnetic tape 104, and a transparent leader tape 105 is connected to the take-up reel 1.
On the other hand, a transparent leader tape 106 is connected to the terminal end of the magnetic tape 104, and a transparent leader tape 106 is connected to the supply reel 1.
It is wound around 02.

Furthermore, when the tape cassette 101 is loaded into a VTR, DAT, etc. (not shown), the tape cassette 1
The front lid 107 (shown by the two-dot chain line) of No. 01 is opened. At this time, a light emitting element 108 such as a lamp is inserted into a hole 101b1 made in the lower half 101b of the tape cassette 101, and the light emitted from this light emitting element 108 is transmitted to the lower half 101b.
Holes 101b2 and 101b3 drilled on both left and right sides of 01b
The light passes through the lower half 101b and is received by light receiving elements 109 and 110 such as CdS, which are disposed outside the left and right sides of the lower half 101b. Here, in both cases where the magnetic tape 104 is pulled out from the tape cassette 101 and made to run, and when it is made to run within the tape cassette 101 without being pulled out, the light emitting element 108 and the light receiving element 109
, 110 does not transmit the light emitted from the light emitting element 108, while the transparent leader tape 10 connected to the start and end ends of the magnetic tape 104
5 and 106 transmit the light emitted from the light emitting element 108, so that the beginning and end of the magnetic tape 104 can be detected.

[0005]

By the way, the magnetic tape start/end detection device 100 shown in FIG. magnetic tape 1
Transparent leader tape 105,
106 has to be connected, which increases the number of work steps when manufacturing the magnetic tape 104, increases the cost of materials for the transparent leader tapes 105 and 106, and consumes the magnetic tape 104 or the tape cassette 101 loaded with the magnetic tape 104. This prevents the provision of products at low prices to customers. Furthermore, since the connection points between the magnetic tape 104 and the transparent leader tapes 105 and 106 are connected by an adhesive, the magnetic tape 104 and the transparent leader tape 105 and
There is also a problem that the adhesive with 106 comes off.

[0006]

[Means for Solving the Problems] The present invention has been made in view of the above-mentioned problems, and the first invention uses a reel having a hub portion that transmits light at the center of a circular flange portion. , the starting end or the ending end of the magnetic tape is fixed to the hub part and then wound, and the starting end and/or the ending end of the magnetic tape is wound around the hub part by an optical signal transmitting/receiving means including a light emitting element and a light receiving element as a set. A magnetic tape start/end detection device for detecting magnetic tape, the device having a reflective surface for changing the direction of the optical path of light emitted from the light emitting element, and engaging with a hole in the hub portion to rotate the reel. disposing the light-emitting element at a position outside the flange portion and near a mounting portion of the rotational driving body;
and a set of the optical signal transmitting and receiving means in which the light receiving element is disposed on the other side, and when a portion where the starting end or the ending end of the magnetic tape is not wound appears on the outer circumferential surface of the hub portion, The magnetic tape is characterized in that the light emitted from the light emitting element is received by the light receiving element via the reflective surface of the rotary drive body to detect whether it is a starting end or a terminal end of the magnetic tape. This is a start/end detection device.

Further, the second invention uses a reel having a hub portion that transmits light in the center of a circular flange portion,
The starting end or the ending end of the magnetic tape is fixed to the hub part and then wound, and the starting end and/or the ending end of the magnetic tape wound around the hub part is fixed to the hub part and then wound. The magnetic tape start/end detection device includes a rotary drive body that engages with a hole in the hub portion to rotationally drive the reel, and a rotary drive body that rotates the reel at a position outside the flange portion and within the hole in the hub portion. a pair of optical signal transmitting/receiving means, the light emitting element being disposed at one position above the rotary drive body, and the light receiving element being disposed at the other position, the outer periphery of the hub portion; When a portion of the magnetic tape in which the start or end of the magnetic tape is not wound appears on the surface, the light emitted from the light emitting element is received by the light receiving element to detect that it is the start or end of the magnetic tape. This is a magnetic tape start/end detection device characterized by having the following configuration.

[0008]

[Embodiment] An embodiment of the magnetic tape start/end detection device according to the present invention will be described below with reference to FIGS. 1 to 6.
Tape cassette>>, <<first embodiment>>, and <<second embodiment>> will be described in detail in this order.

In the first and second embodiments of the magnetic tape start/end detection device according to the present invention, the light emitting element and the light receiving element are connected to one another without connecting the transparent leader tape to the start and end ends of the magnetic tape. The common technical idea is that the start and/or end of the magnetic tape is detected by optically detecting the state of the outer circumferential surface of the hub portion of the reel using a set of optical signal transmitting and receiving means. be.

<<Tape Cassette>> FIG. 1 is a perspective view of a tape cassette used in a magnetic tape start/end detection device according to the present invention, viewed from the lower half side, and FIG. 2 is a perspective view of the tape cassette with the upper half removed. FIG.

First, a tape cassette used in the magnetic tape start/end detection device according to the present invention will be explained. This tape cassette includes the first embodiment and the second embodiment.
This is used together with the examples.

The tape cassette 1 shown in FIG.
Tape recorder (VTR), digital audio
It has a well-known structure used in tape recorders (DAT), etc., and is formed by combining a lower half 2 and an upper half 3 to form a box 4 in the shape of a rectangular parallelepiped. A lid 5 is attached so that it can be opened and closed freely. In addition, the lower half 2 has a pair of reel shaft holes 2a1 and 2a2, and a hole 2a2.
b, 2c are bored.

Furthermore, as shown in FIG. 2, a supply reel 6 and a take-up reel 7 are installed inside the lower half 2, and tape guides 8 are provided at both left and right ends of the front side of the lower half 2.
, 9 have been planted. A magnetic tape 10 is wound between the supply reel 6 and the take-up reel 7.
It is wound onto the take-up reel 7 while being attached to the winding reel 7. At this time, the start end side of the magnetic tape 10 is wound on the take-up reel 7.
A transparent leader tape as shown in the conventional example is not wound around the hub portion 7a of the supply reel 6 and the hub portion 6a of the supply reel 6 around which the end side of the magnetic tape 10 is wound, and the starting end of the magnetic tape 10 is wound on the take-up reel 7. The end of the magnetic tape 10 is directly fixed to a part of the outer peripheral surface 6a1 of the hub part 6a of the supply reel 6 and then wound.

Here, the supply reel 6 and the take-up reel 7
The structure of is briefly explained. Since the supply reel 6 and the take-up reel 7 have the same structure, only the supply reel 6 will be described, and the same auxiliary symbols will be used as appropriate in each figure for the constituent members of the take-up reel 7 that are the same as the supply reel 6. .

A circular upper flange portion 6b and a lower flange portion 6c are provided above and below the central hub portion 6a of the supply reel 6.
(Only the upper flange portion 6b is shown) are fixed to face each other, and when the hub portion 6a and the upper and lower flange portions 6b and 6c are combined, they are formed into an "E" shape as shown in FIG. 4. Further, a plurality of uneven engagement portions 6a3 are formed in the hole 6a2 in the inner peripheral portion of the hub portion 6a. Furthermore, the hub portion 6a
As will be described later, the light emitting element 40 (FIG. 4) is made of a material that can transmit light emitted from the light emitting element 40 (FIG. 4), and is made of a substantially transparent resin material, for example. The flange portions 6b and 6c fixed to the hub portion 6a may be molded using the same material as the hub portion 6a, or may be molded using a different material from the hub portion 6a.

A well-known reel brake mechanism member 11 is provided at the center of the rear side of the lower half 2, and is constantly connected to the outer periphery of the lower flange portion 6c of the supply reel 6 and the lower flange portion 7c of the take-up reel 7. A reel brake mechanism member 11 is in contact with the outer periphery to prevent the magnetic tape 10 from loosening, and when the tape cassette 1 is loaded into a VTR, DAT, etc., a reel brake release member (not shown) protrudes from below through the hole 2c and releases the reel. The brake mechanism member 11 is configured to be released.

Furthermore, the hole 2b of the tape cassette 1 described above
A light emitting element 40 (FIG. 4) or a light receiving element 41 (FIG. 4), which will be described later, can be inserted from below.

In the description of the magnetic tape start/end detection device of this embodiment, the tape cassette 1 having the above structure will be described.
Although the description below will be made using the following, the invention is not limited to this, and a pair of well-known open reels may be used.Although this open reel is not shown, the hub portion is similarly connected to the light emitting element 40 (FIG. 4).
) may be made of a material that can transmit the light emitted from it.

<<First Embodiment>> FIG. 3 is a plan view showing a magnetic tape start/end detection device according to a first embodiment of the present invention, and FIG. 4 is a diagram taken along the line X--X in FIG. FIG. 5 is a vertical sectional view showing the configuration of the magnetic tape start/end detection device of the first embodiment, and FIG. It is a figure for explaining.

In the magnetic tape start/end detection device 20A of the first embodiment shown in FIGS. 3 and 4, the supply reel 6 side and the take-up reel 7 side have the same configuration. The 6 side will be explained using FIGS. 3 and 4, and the take-up reel 7 side will be explained as necessary.

In FIGS. 3 and 4, tape cassette 1
is automatically loaded in advance into a predetermined reel mounting position of a video tape recorder (VTR), digital audio recorder (DAT), etc.

As shown in FIG. 4, a rotation drive body 30 that rotatably supports a supply reel 6 is rotatably mounted on a stepped reel shaft 22 fixed to a chassis 21 of a VTR, DAT, or the like. In the first embodiment, this rotary drive body 30 mainly includes a gear 31, a reel stand 32, a reel engaging member 35, and the like. Incidentally, the rotary drive body 30 does not necessarily need to be constructed from the above-mentioned structural members, and for example, it may be one provided with a reflective surface 35b of a reel engaging member 35, which will be described later, and the corresponding members of the reel engaging member 35 are not shown. It is also possible to directly fix it to the shaft of a motor and use it as a rotational drive body.

That is, the rotary drive body 30 shown in the embodiment
Here, a gear 31 and a reel stand 32 are pivotally attached to the narrow diameter portion 22a of the reel shaft 22. Furthermore, a friction member 33 such as felt is interposed between the gear 31 that is pivoted below the narrow diameter portion 22a of the reel shaft 22 and the reel stand 32 that is pivoted above.

Further, the large diameter portion 32a of the reel stand 32 protrudes into the hole 2a1 from below the lower half 2 and is in contact with the lower surface of the hub portion 6a of the supply reel 6. A compression spring 34 is fitted into the narrow diameter portion 32b of the reel stand 32 inserted into the hole 6a2, and a reel engaging member 35, which is a main component of the rotary drive body 30, is inserted from above the compression spring 34. are mated. Further, a reel shaft 2 is provided at the upper end of the narrow diameter portion 32b of the reel stand 32.
A cap 36 fitted into the narrow diameter portion 22a of No. 2 is in contact with the cap 36, and upward movement of the cap 36 is restricted by an E washer 37.

Here, the narrow diameter portion 32b of the reel stand 32 is shown in FIG.
It is formed in a hexagonal shape as shown in FIG.
The reel engaging member 35 is fitted into the reel engaging member 3 b.
5 is always urged upward by the urging force of the compression spring 34, and although upward movement is restricted by the cap 36, downward movement is permitted.

Further, as shown in FIG. 3, an engaging portion 35a protrudingly provided at a position where the outer periphery of the reel engaging member 35 is divided into three equal parts.
can be engaged at appropriate positions with a plurality of uneven engagement parts 6a3 formed in the hole 6a2 of the hub part 6a of the supply reel 6, and when the supply reel 6 rotates, the reel engagement The engaging portion 35a of the mating member 35 and the supply reel 6
The driving force is transmitted between the engaging portion 6a3 and the engaging portion 6a3. Note that when loading the tape cassette 1, the reel engaging member 3
When the engaging part 35a of the reel engaging member 35 cannot engage with the engaging part 6a3 of the supply reel 6, the engaging part 35a of the reel engaging member 35 is pushed by the engaging part 6a3 and moves downward; When either the supply reel 35 or the supply reel 6 rotates, they can engage with each other, thereby causing the engaging portion 35a to move upward while engaging with the engaging portion 6a3. Furthermore, the biasing force of the compression spring 34 also acts downward, and the biasing force of the compression spring 34 acting on the reel stand 32 pushes the reel stand 32 toward the gear 31 via the friction member 33, so that the reel is always The stand 32 and the gear 31 are integrated with each other via a friction member 33. Further, the gear 31 is meshed with a gear of a drive transmission member connected to a drive source (not shown), so that the gear 31 and the reel stand 32 can rotate as one, and furthermore, the gear 31 and the reel stand 32 can rotate together. The reel engaging member 35 fitted into the diameter portion 32b can also rotate together, so that driving force can be transmitted to the supply reel 6.

Furthermore, the engaging portion 35a of the reel engaging member 35
A conical reflecting surface 35b inclined at an angle of approximately 45 degrees is formed below. This reflective surface 35b is processed into a mirror surface by depositing an aluminum material or the like using a well-known vapor deposition technique. This reflective surface 35b has a function of changing the direction of the optical path of light emitted from the light emitting element 40, which will be described below.

Further, the reel stand 32 and the gear 31 are made of a material that can transmit the light emitted from the light emitting element 40 described below, similar to the hub portion 6a of the supply reel 6 described above, such as a substantially transparent resin material. It is formed of.

[0029] Here, an optical signal exchange means including a light emitting element 40 and a light receiving element 41 as a set will be explained.

The light emitting element 40 and the light receiving element 41 of the optical signal transmitting/receiving means use well-known photosensors, and the light emitting element 4
0 and the light receiving element 41 are not particularly limited, but the light emitting element 40 may be a lamp or a light emitter (
(LED, EL, etc.) are used. Furthermore, light emitting element 4
The light emitted from 0 is visible light or infrared light. In addition, the light emitting element 40 is pulse-modulated, the light is received by the light receiving element 41, and the synchronization state and level of the received light and the original light emitted from the light emitting element 40 are compared to accurately distinguish it from external light. Although other methods can also be adopted, detailed description thereof will be omitted here.

The light emitting element 40 as described above is inserted into the hole 2b from below the lower half 2 when the tape cassette 1 is loaded, and the position of the light emitting element 40 is determined as shown in the figure. They are disposed outside the upper and lower flange portions 6b and 6c of the reel 6. Furthermore, the light emitting element 40 serves as a common light source for the supply reel 6 side and the take-up reel 7 side, as shown in FIG. Returning to FIG. 4, the light receiving element 41 is fixed to the chassis 21 to which the rotary drive body 30 is attached, that is, it is disposed below the gear 31 and near the reel shaft 22.
is arranged at a position where it can receive the light emitted from the reflective surface 35b of the reel engaging member 35. Then, the light emitted from the light emitting element 40 travels straight along the optical path indicated by the arrow, which is almost parallel to the flanges 6b and 6c of the supply reel 6, and passes through the hub section 6a of the supply reel 6 to pass through the reel engaging member. 35 is incident on the reflective surface 35b. Almost 45 more
The light incident on the reflective surface 35b tilted at an angle of 100 degrees is converted into an optical path almost at right angles and is emitted from the reflective surface 35b, and this light travels straight downward along the optical path indicated by the arrow and is received by the light receiving element 41. be done. Note that the light emitting element 40 and the light receiving element 4
Even if the arrangement position of 1 is changed from the above, the light emitting element 40 is fixed to the chassis 21 to which the rotary drive body 30 is attached, and the light receiving element 41 is inserted into the hole 2b of the lower half 2, there is no problem. No hindrance will occur. However, in this case, considering that the take-up reel 7 side has the same configuration, two sets of the light emitting element 40 and the light receiving element 41 are required. Therefore, the optical signal transmitting/receiving means has a light emitting element 40 disposed at one of the outer side of the flange part of the reel 6 (7) and a position near the attachment part of the rotary drive body 30, and a light receiving element 41 disposed at the other position. It is a good idea to set it up.

Next, the operation of the magnetic tape start/end detecting device 20A of the first embodiment having the above configuration will be explained.

First, the operating principle of the magnetic tape start/end detection device 20A of the first embodiment having the configuration shown in FIG. When not being rotated, the light emitted from the light emitting element 40 passes through the hub portion 6a and enters the reflective surface 35b of the reel engaging member 35 as described above, and is further converted in optical path by the reflective surface 35b to the light receiving element 41. The light is received by On the other hand, when the magnetic tape 10 is wound around the hub portion 6a of the supply reel 6, the light emitted from the light emitting element 40 is blocked by the magnetic tape 10 and cannot pass through the hub portion 6a. Since the light emitted from the light receiving element 40 does not reach the light receiving element 41, the light receiving element 41 is unable to receive the light.

The above operating principle can be applied not only to the supply reel 6 side but also to the take-up reel 7 side having the same configuration.If the state shown in FIG. 3 is explained according to this operating principle, the light emitted from the light emitting element 40 The light receiving elements 41, 41 are arranged at the illustrated positions where the light receiving elements 41, 41 on the supply reel 6 side and the take-up reel 7 side can receive the light, respectively. Furthermore, although the starting end of the magnetic tape 10 is directly fixed to a part of the outer circumferential surface 7a1 of the hub portion 7a of the take-up reel 7 on the take-up reel 7 side, the magnetic tape 10 is A portion where the starting end is not wound appears, and the light emitted from the light emitting element 40 is transmitted through the hub portion 7a and is transmitted to the light receiving element 41 via the reflective surface 35b (FIG. 4) of the reel engaging member 35. Light is received. This results in
The light receiving element 41 detects the beginning of the magnetic tape 10.

On the other hand, on the supply reel 6 side, the magnetic tape 10
Since the magnetic tape 10 is wound many times after the end of the magnetic tape 10 is directly fixed to a part of the outer peripheral surface 6a1 of the hub portion 6a of the supply reel 6, the light emitted from the light emitting element 40 is The light is blocked and cannot reach the light receiving element 41. As a result, the light receiving element 41 does not detect the end of the magnetic tape 10.

After that, when the magnetic tape 10 is run in the direction of the arrow and is completely wound onto the take-up reel 7 side, the above is reversed. A portion where the terminal end is not wound appears, and the light emitted from the light emitting element 40 is transmitted through the hub portion 6a and received by the light receiving element 41 via the reflective surface 35b (FIG. 4) of the reel engaging member 35. The end of the magnetic tape 10 is detected, while the start end of the magnetic tape 10 is not detected on the take-up reel 7 side.

As described in detail above, in the magnetic tape start/end detection device 20A of the first embodiment, the light emitting element 40 is The hub portions 6 of the reels 6 and 7 are
The start and/or end of the magnetic tape 10 is detected by optically detecting the states of the outer circumferential surfaces 6a1, 7a1 of the magnetic tapes 6a, 7a. This eliminates the work of connecting transparent leader tapes as in the past, and it becomes possible to provide consumers with the magnetic tape 104 or the tape cassette 101 loaded with the magnetic tape 104 at a low cost. Further, since an adhesive for connecting the transparent leader tape is not required and the adhesive does not change over time, the magnetic tape 104 or the magnetic tape 1
The reliability and quality of the tape cassette 101 equipped with 04 are significantly improved. Furthermore, according to the configuration of the first embodiment, the outer peripheral surface 6 of the hub portion 6a of the reel 6 (7)
Since there is no need to increase the diameter of a1, there is an advantage that the amount of winding of the magnetic tape 10 can be increased.

Next, a case where the light emitting element 40 and the light receiving element 41 are disposed at positions different from those described above in the magnetic tape start/end detecting device 20A of the first embodiment will be described with reference to FIG.

In FIG. 5, it is a necessary condition that either one of the light emitting element 40 and the light receiving element 41 be disposed near the attachment part of the rotary drive body 30, but the other one must be disposed at a position near the attachment part of the rotary drive body 30. Can be placed at any location. That is, the other light-emitting element 40 or light-receiving element 41 may be disposed at, for example, the positions from ■ to ■ within the tape cassette 1, or at an appropriate position ranging from ■ to ■ on the outside of the tape cassette 1. is also possible. At this time, it is necessary to consider mutual directions when arranging the light emitting elements 40 so that the light emitted from the light emitting element 40 can be received by the light receiving element 41 without fail. Furthermore, when the tape cassette 1 is used and placed at an appropriate position ranging from ■ to ■ on the outside of the tape cassette 1, the material of the box body 4 (FIG. 1) of the tape cassette 1 is emitted from the light emitting element 40. It is necessary to limit it to materials that can transmit light. However, when a well-known open reel is used without using the tape cassette 1, the position where the other light emitting element 40 or light receiving element 41 is disposed has further increased flexibility.

<<Second Embodiment>> FIG. 6 is a vertical sectional view showing the structure of a magnetic tape start/end detection device according to a second embodiment of the present invention.

In the magnetic tape start/end detection device 20B of the second embodiment, transparent leader tapes are placed at the start and end ends of the magnetic tape 10 in the magnetic tape start/end detection device 20A of the first embodiment described above. without connecting
The technical idea is to optically detect the state of the outer circumferential surface of the hub portion of the reel using an optical signal transmitting/receiving means including a light emitting element 40 and a light receiving element 41 as a set to detect the start end and/or end end of the magnetic tape 10. However, some of the configurations are different from the first embodiment, and only the different points from the first embodiment will be explained here.

In the magnetic tape start/end detection device 20B of the second embodiment shown in FIG. 6, the constituent members of the rotary drive body 50 are partially different from those of the rotary drive body 30 of the first embodiment. The reel engaging member 51 does not have the reflective surface 35b of the reel engaging member 35 (FIG. 4) described above. Furthermore, a light receiving element 41 is provided above the reel engaging member 51 within the hole 6a2 of the hub portion 6a of the supply reel 6.

That is, a wiring hole 52a for the light receiving element 41 is formed in a stepped reel shaft 52 fixed to a chassis 21 of a VTR, DAT, or the like. Further, a light receiving element 41 is fixed to the upper end of the reel shaft 52 in the hole 6a2 of the hub portion 6a of the supply reel 6.
is fixed within the hole 6a2 of the hub portion 6a without rotating. A rotary drive body 50 that rotatably supports the supply reel 6 is rotatably attached to the reel shaft 52 below the light receiving element 41 . In the second embodiment, this rotary drive body 50 mainly includes a gear 31, a reel stand 53, a reel engaging member 51, and the like.

The reel stand 53 is similar to the reel stand 32 described above.
(Fig. 4), and this reel stand 5
3 and a gear 31 are pivotally attached to a reel shaft 52. Here, the thickness of the narrow diameter portion 53b of the reel stand 53 is the same as that of the reel shaft 52.
The hole 52a is only thicker than the hole 52a. Further, the reel engaging member 51 is fitted into the hexagonal narrow diameter portion 53b of the reel stand 53.
is always urged upward by the urging force of the compression spring 34, and its upward movement is restricted by the light receiving element 41, but its downward movement is permitted. Further, an engaging portion 51 protrudingly provided at a position where the outer periphery of the reel engaging member 51 is divided into three equal parts.
a can be engaged at an appropriate position with a plurality of uneven engaging portions 6a3 formed in the hole 6a2 of the hub portion 6a of the supply reel 6, and when the supply reel 6 rotates, the reel Driving force is transmitted between the engaging portion 51a of the engaging member 51 and the engaging portion 6a3 of the supply reel 6. Note that, as in the first embodiment, the light emitting element 40 is inserted into the hole 2b from below of the lower half 2.

In the magnetic tape start/end detection device 20B of the second embodiment configured as described above, the light emitted from the light emitting element 40 is almost parallel to the flange portions 6b, 6c of the supply reel 6 and follows the optical path indicated by the arrow. The light travels straight along the supply reel 6, passes through the hub portion 6a of the supply reel 6, and is directly received by the light receiving element 41. The operation and effects of the magnetic tape start/end detection device 20B of the second embodiment can be easily inferred from the above-described first embodiment, so a description thereof will be omitted here.

Furthermore, in the configuration of the magnetic tape start/end detection device 20B of the second embodiment described above, the light emitting element 4
0 and the light-receiving element 41 are replaced with the above, the light-emitting element 40 is provided in the hole 6a2 of the hub portion 6a of the supply reel 6 at a position above the rotary drive body 50, and the light-receiving element 41 is placed in the lower half 2. Even if it is inserted into the hole 2b, no problem will occur. However, in this case, considering that the take-up reel 7 side has the same configuration, the light emitting element 40 and the light receiving element 4
Two sets of 1 are required. Therefore, the optical signal transmitting/receiving means arranges the light emitting element 40 either outside the flange parts 6b, 6c of the reel 6 (7) or above the rotary drive body 50 in the hole 6a2 of the hub part 6a, It is only necessary to arrange the light receiving element 41 on the other side.

Furthermore, if the light emitting element 40 and the light receiving element 41 are disposed at different positions from those in the second embodiment, FIG. 5 can be applied in the same way as in the first embodiment, and the explanation will be omitted.

Further, as a modification of the second embodiment, the diameter of the outer circumferential surface 6a1 of the hub portion 6a of the reel 6 (7) is formed to be larger than the diameter of the large diameter portion 53a of the reel stand 53, and the outer circumferential surface 6a1 is A recess is formed in the nearby hub part 6a, and one of the light emitting element 40 and the light receiving element 41 is disposed from the outside of the large diameter part 53a of the reel stand 53 into the recess of the hub part 6a, and the other is placed on the reel. It is also possible to detect the start and/or end of the magnetic tape 10 by arranging it outside the flange parts 6b and 6c of 6(7), but in this case, the diameter of the outer circumferential surface 6a1 of the hub part 6a becomes extremely large, which causes problems such as a decrease in the amount of winding of the magnetic tape 10 and a shortening of recording and/or reproduction time. On the other hand, the second embodiment has the advantage that the amount of winding of the magnetic tape 10 can be increased because there is no need to increase the diameter of the outer circumferential surface 6a1 of the hub portion 6a due to the above-described configuration.

[0049]

Effects of the Invention According to the magnetic tape start/end detection device according to the present invention detailed above, claims 1 and 2 are obtained.
In the description, the state of the outer circumferential surface of the hub portion of the reel is determined using an optical signal transmitting/receiving means including a light emitting element and a light receiving element as a set, without connecting the transparent leader tape explained in the conventional example to the start and end ends of the magnetic tape. The magnetic tape is configured to optically detect the start and/or end of the magnetic tape. This eliminates the conventional work of connecting transparent leader tapes, and it becomes possible to provide consumers with magnetic tapes or, for example, tape cassettes loaded with magnetic tapes, at low cost. Furthermore, according to the above configuration, there is no need for an adhesive to connect the transparent leader tape, and the adhesive does not change over time, so the reliability and quality of magnetic tape or tape cassettes equipped with magnetic tape, for example, are significantly improved. There are advantages to doing so. Further, according to the above configuration, there is no need to increase the diameter of the outer circumferential surface of the hub portion of the reel, so there is an advantage that the amount of winding of the magnetic tape can be increased.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a tape cassette used in a magnetic tape start/end detection device according to the present invention, viewed from the lower half side.

FIG. 2 is a plan view with the upper half of the tape cassette used in the magnetic tape start/end detection device according to the present invention removed.

FIG. 3 is a plan view of a magnetic tape start/end detection device according to a first embodiment of the present invention.

4 is a vertical sectional view taken along the line XX in FIG. 3 and showing the configuration of the magnetic tape start/end detection device of the first embodiment; FIG.

FIG. 5 is a diagram for explaining a case where a light emitting element and a light receiving element are disposed at a different location from the first embodiment.

FIG. 6 is a vertical sectional view showing the configuration of a magnetic tape start/end detection device according to a second embodiment of the present invention.

FIG. 7 is a diagram showing the configuration of a conventional magnetic tape start/end detection device.

[Explanation of symbols]

6... Supply reel, 6a... Hub part, 6b... Upper flange part,
6c...lower flange portion, 6a1...outer circumferential surface, 6a2...hole, 6
a3...Engagement part, 7...Take-up reel, 7a...Hub part, 7b
...Upper flange part, 7c...Lower flange part, 7a1...Outer peripheral surface, 7a2...Hole, 7a3...Engagement part, 10...Magnetic tape, 20A...Magnetic tape start/end detection device of the first embodiment, 20B...No. Magnetic tape start/end detection device of 2nd embodiment, 30...rotary drive body, 35...reel engaging member, 35
a... Engaging portion, 35b... Reflective surface, 40... Light emitting element, 41...
Light receiving element, 50...Rotation drive body, 51...Reel engaging member.

Claims (2)

[Claims] [Claim 1] Using a reel equipped with a hub part that transmits light in the center of a circular flange part, the starting end or the ending end of a magnetic tape is fixed to the hub part and then wound, and a light emitting element and a light receiving element are formed. A magnetic tape start/end detection device for detecting the start and/or end of the magnetic tape wound around the hub portion using a set of optical signal transmitting/receiving means, the device detecting the start and/or end of the magnetic tape wound around the hub portion, a rotary drive body that has a reflective surface that changes the direction of the optical path and that engages with a hole in the hub portion to rotationally drive the reel; a pair of optical signal transmitting/receiving means in which the light emitting element is disposed at one position and the light receiving element is disposed at the other position; When a portion where the starting end or the ending end is not wound appears, the light emitted from the light emitting element is received by the light receiving element via the reflective surface of the rotary driver, and the part is the starting end or ending end of the magnetic tape. 1. A magnetic tape start/end detection device, characterized in that it is configured to detect. 2. Using a reel equipped with a hub part that transmits light in the center of a circular flange part, the starting end or the ending end of a magnetic tape is fixed to the hub part and then wound, and a light emitting element and a light receiving element are formed. A magnetic tape start/end detection device that detects the start and/or end of the magnetic tape wound around the hub using an optical signal transmitting/receiving means including a pair of a rotary drive body that rotationally drives the reel; the light emitting element is disposed at one of an outer position of the flange portion and an upper position of the rotary drive body within a hole of the hub portion; 1 in which the light receiving element is arranged
when a portion of the outer peripheral surface of the hub portion where the starting end or the ending end of the magnetic tape is not wound, the light emitted from the light emitting element 1. A magnetic tape start/end detection device, characterized in that it is configured to detect a start or end of the magnetic tape by receiving light with a light-receiving element.