JPH04109479A - Tape cassette - Google Patents

Abstract

PURPOSE:To detect both the head end and the tail end of a tape by the same light emitting element by incorporating a winding and a feeding reels to which transparent head and tail end tapes are anchored respectively as separating them by prescribed distance, and forming plural optical paths with a magnetic tape traveling path between. CONSTITUTION:A sensor hole 11 into which the light emitting element 46 to detect detection tapes different in light transmittance from the tape 4 and provided at the end and the tail ends of the tape 4, and send tape head and tail end information is inserted is provided, and the light emitting element 46 forms the optical paths 12a, 13a. When a loading base plate 62 is moved, the light emitting element 46 supported by an element lever 77 is pressed against the end part 88a of a U groove 88 constituted at one end of a loading guide 63, and is rotated clockwise around the center of a supporting shaft 76, and the light emitting element 46 is positioned by a V groove 61a formed at a part of a driving base plate 61, and simultaneously, the position of the light emitting element 46 for a short-time cassette 30 is stored in a recessed part 39a. Thus, since each optical path 12a, 13a is formed, the head and the tail ends of the tape can be detected by the single light emitting element 46.

Description

[Detailed description of the invention]

[0001]

[Industrial application field]

The present invention relates to a tape cassette used in a recording and reproducing apparatus, such as a video tape recorder, which records or reproduces signals by winding a tape at a predetermined angle around a tape guide drum incorporating a transducer. [0002]

[Conventional technology]

Video tape recorders (hereinafter referred to as VTRs) have become rapidly popular, and the weight and size of the devices have become an issue in order to enjoy outdoor shooting using portable VTRs. Video cameras and electrical circuits are becoming smaller year by year due to smaller components and the extensive adoption of semiconductor components, and will continue to become smaller in the future. On the other hand, the size limit of the VTR mechanism is determined by the size of the tape cassette and the diameter of the tape guide drum. That is, the size is determined by the design, such as by arranging both on a plane at positions separated by a predetermined pressure, and then pulling out the tape from the tape cassette and winding it around the tape guide drum. Therefore, in order to reduce the size of this mechanism, a short-time recording cassette called [VH3-Cl] was proposed in the VH3 system, and an attempt was made to reduce the size of the mechanism by making the cassette smaller. Furthermore, by devoting the tape guide drum exclusively to recording, we have developed the so-called 1
, a 5-head system, or a 4-head system has been proposed. In this way, by downsizing both the tape guide drum and tape cassette, the mechanism is being downsized. Hereinafter, the miniaturization of the mechanism due to the miniaturization of the cassette will be explained. [0003] A VH3-C system cassette 102 (hereinafter referred to as a C cassette) is shown in FIG. 31. The distance between the tapes and the tape stretching position are also different. However, in order to make both compatible, by inserting the C cassette into the adapter cassette 101 whose maximum external dimensions are the same as the standard cassette, the C cassette has the same reel axis distance and the same tape as the standard cassette. The tension position is obtained. In this way, C cassette)
102 can be inserted into a VTR capable of recording and reproducing standard cassettes for recording and reproducing in the same manner. It is impossible to insert a Nekron standard cassette into the recording/reproducing VTR of the C cassette 102. The advantage of the adapter cassette system, typified by the VH3-C system, is the miniaturization of the mechanism mentioned above, but the following disadvantages arise due to this. (1) In order to insert the C cassette 102 into a standard cassette VTR, an expensive adapter cassette 101 is required, and the user is forced to purchase this adapter cassette 101 and perform a complicated process of inserting and removing it into the adapter cassette 101. . [0004] (2) The C cassette 102 is the adapter cassette 101
In order to insert the tape into the adapter cassette 101 and pull out the tape to the same tape tensioning position as the standard cassette, the front lid of the C cassette 102 must be left open inside the adapter cassette 101. Therefore, the lid is not allowed to protrude from the adapter cassette 101 in the open state. This places a significant restriction on the front lid structure of the C cassette 102, and in reality, the C cassette 102 cannot have a completely sealed structure for the tape and does not have a lid locking mechanism. [0005] (3) Since the C cassette 102 has the supply reel 103 at the same position as the standard cassette in order to give priority to tension characteristics, the take-up reel 104 is constructed by installing a shaft inside the C cassette 102. Adapter cassette 1
A method has been selected in which the gears are connected and driven with the relay gears 105 and 106 of o1. In this method, this gear 105.10
Due to the influence of the uneven engagement of No. 6, problems such as playback image vibration and wow and flutter occur in the tape running system, leading to performance deterioration. [0006] Adapter cassette 1 that is the basis of these problems
There is a system that achieves a compatible small tape cassette (hereinafter referred to as a small cassette) without using 01. This is a 374-inch cassette used for broadcasting, etc., as shown in Fig. 32. The /J1 cassette 107 in this case has the same distance between the reel axes and the same tension tape tensioning position as the standard cassette 108. However, since the diameter of the reel flange 109 is reduced by reducing the recording time, the width W of the cassette and the length D from the reel axis to the rear surface of the cassette are shortened to make the cassette /JN type. . [0007] Although this method does not have the above-mentioned drawbacks compared to the former adapter cassette method, it does have the following drawbacks. [0008] (1) A force plate that forms a concave guide groove 110 as shown by the broken line in Figure 32 on the bottom of the cassette as a guide when inserting two cassettes with different external dimensions into a VTR. This causes the film to thicken. [0009] (2) It is necessary to provide a convex projection on the cassette holder of the VTR corresponding to the guide groove 110. Furthermore, when inserting the small cassette 107 into a standard cassette VTR, since the length D from the reel axis to the rear surface of the cassette is short, it is necessary to insert the small cassette 107 more than the standard cassette 108, resulting in poor operability. [00101 (3) On the contrary, when trying to take out the small cassette 107 from the cassette holder under the above-mentioned conditions, it is more difficult to take it out than when it is inserted. Therefore, the small cassette 107 is provided with a recess 111 in the center of the rear surface of the cassette, and the cassette can be taken out by hooking the finger thereon.Although it is not easy to operate, it is possible to insert the finger into the cassette holder and hook the small cassette 107. There is a natural limit to the size of the small cassette 107,
This was possible because of the thickness and width of the cassette, which has a tape width of 374 inches. [0011] (4) Since the distance between the reel axes and the tape stretching position are also the same, there is a limit to the miniaturization of the small cassette (107) compared to the standard cassette, and it does not contribute as much to the miniaturization of the mechanism as the VH3-C system. [0012]

[Problem to be solved by the invention]

The above describes two approaches to miniaturization of cassettes, and both plate-side methods have advantages and disadvantages, and should never be satisfied. [0013] On the other hand, in both types, both ends of the tape are respectively latched to the reel in the tape cassette via a detection tape having a different light transmittance from the tape in order to detect the beginning and end of the tape and stop the tape from running. are doing. In a 374-inch VTR, a receiver 9 light-emitting element is provided outside the tape cassette in order to form an optical path through the tape after the tape cassette is pulled out from the tape. In this case, it is necessary to insert one of the two receiving and emitting elements into the drawn-out tape loop, requiring a relatively complicated mechanism in which the tape loop is escaped during formation and then inserted after formation. There is also a method that simplifies this and involves installing the light emitting element through a tape and fixing it at an angle with respect to the width direction of the tape. However, in this case as well, it is necessary to arrange the tape pull-out member outside the moving path of the tape loop in the process of forming the tape loop, so an extremely large arrangement size is required. These problems place significant limitations on devices using short-time recording tape cassettes aimed at miniaturization. On the other hand, in the VH3 system VTR,
As shown in Japanese Patent No. 30889, a sensor hole is provided in the bottom of the tape cassette to communicate optically with the inside, a light emitting element is inserted into the sensor hole, and a light receiving element is inserted at a predetermined position outside the tape cassette. By providing a pair of optical paths, a pair of optical paths are formed through the tape stretched inside the tape cassette, corresponding to the beginning and end of the tape. [0014] In this case, the receiver 2 light-emitting element, which is the tape start/end detecting means, can function only when an adapter cassette for a long-time recording tape cassette and a short-time recording tape cassette (C-cassette) is used. However, the C-cassette does not have a sensor hole, and after pulling the tape out of the tape cassette, the beginning and end ends are detected through the tape inside and outside the tape loop, causing the same problem as 374-inch VTRs. It has points. In particular, when the tape cassette and tape guide drum are placed close to each other in order to achieve ultra-compact C-cassette, the start and end ends are detected outside the tape cassette, so the mode shifts to stop mode rather than fast forward or fast reverse. When the tape is overrun, the joint between the tape and the detection tape reaches the top of the tape guide drum, causing crawling of the video head. [0015] In view of these conventional drawbacks, the present invention improves / of the mechanism.
The object of the present invention is to provide a tape cassette which greatly contributes to the J1 type and which makes it possible to detect the start and end ends of the tape contained in the tape cassette using start and end end detection means comprising the same light receiving and emitting elements. [0016]

[Means to solve the problem]

A take-up reel and a supply reel each locking transparent starting and ending tapes formed at both ends of a magnetic tape, and the take-up and supply reels are built in at a predetermined distance apart, and one of the starting and ending tapes is detected. In order to achieve this, a tape cassette is constituted of a housing portion in which a plurality of optical paths formed by light transmitting holes or transparent light transmitting members are formed with the magnetic tape running path sandwiched therebetween. [0017]

[Effect]

According to the above configuration, in a short-time cassette in which the light-emitting element and the light-receiving element for detecting the start and end of a tape are formed so that three optical paths are possible, for example, the light-emitting element, which is a component of the same start-and-end end detection means, is connected to the cassette. Starting and ending points can be detected in the same way even when moving backwards. If the light-emitting element can be moved rearward, there will be no restriction on the amount of entry of the guide drum due to the light-emitting element being in the front, and the range of openings into which the guide drum can enter will be increased. [0018] If three optical paths are formed in the short-time cassette, including an optical path common to the optical path of the long-time cassette, the short-time cassette can be attached to a conventional VTR exclusively for long-time cassettes, and the beginning and end can be detected. It becomes possible to ensure mutual compatibility of different types of tape cassettes. As a result, instead of a VTR exclusively for short-time cassette use as in the past, the VT can be used for both short-time and long-time use.
If the cassette is installed in the VTR for a short time, the light emitting element can be moved to the rear of the cassette, the guide drum can be moved deeply into the opening of the tape cassette, and the mechanism can be made smaller. [0019]

【Example】

Hereinafter, one embodiment of the present invention will be described in detail with reference to the drawings. Figures 2 to 49 Figures 6 and 7 show a standard cassette capable of long-term recording and playback according to the present invention, and Figure 2 is a perspective view from above, showing a pair of built-in reels when the standard cassette is not in use. 2, 3 (see Figure 3),
A tape 4a (indicated by a dotted chain line in FIG. 3) stretched over the front surface of the standard cassette 1 is covered by a rotatable front cover 5 and a back cover 6, respectively. FIG. 3 is a perspective view of the standard cassette 1 shown in FIG. 2 flipped 180 degrees.
The lower surface 1a of the standard cassette 1 has an opening 7 (an opening 39 of a short-time recording tape cassette (described later) in FIG. The opening is within the range covered by Figure 26), and is called a relatively small opening.)
will be provided. Then, the standard cassette 1 is opened and closed by the front lid 5. FIG. 4 shows a state in which the back cover 6 is opened. FIG. 6 is a plan view schematically showing the internal structure of the standard cassette 1. By engaging with claws formed on the outer periphery of the flanges 2a and 3a of the reels 2 and 3 around which the tape 4 is wound, the tape It is equipped with a reel lock 8 that prevents the occurrence of slack in the reel. Also, the thickness of tape 4 is 1
Information such as type, length, etc. is expressed in an information window 9 formed on the bottom surface 1a of the standard cassette, depending on whether the hole is open or closed. 1
0 is a positioning hole for positioning the standard cassette 1 in the main unit, and 11 is a detection tape provided at the beginning and end of the tape 4, which has a different light transmittance from the tape 4, and detects tape start and end end information. This is a sensor hole into which a light emitting element is inserted to transmit information. This light-emitting element forms an optical path 12, 13 indicated by an arrow, and a light-receiving element is provided on the opposing surface in correspondence with the light-emitting element. [00201 FIGS. 8 to 10, front lid 5. The details of the opening/closing operation of the back cover 6 are shown in cross-sectional view, and the fork 8 is the A-A cross section in FIG. 6, and FIG.
FIG. 10 is a cross section taken along line BB in FIG. The front lid 5 is rotatably supported at both front ends of the side surfaces of the standard cassette 1. 5C
is a support shaft around which the front cover 5 rotates, and 5a is an arm that rotatably supports a support shaft 6a of the back cover 6. This back cover 6 has a protrusion 6b, and this protrusion 6b is the standard cassette 1.
It engages with a guide groove 14 formed in the side wall 7a of the opening 7. The lid mechanism with the above configuration is biased to the state shown in FIG. 8 by an elastic member, but due to an external force,
The lid opening/closing trajectory is shown in Figure 10. At this time, the back cover 6 is guided by a guide groove 14 for the purpose of opening and closing smoothly without contacting the tape 4a contained therein. [002] FIG. 12 is a schematic cross-sectional view of FIG. 11 and a side view.
2 is a view of the vicinity of the left side surface 5b of the front cover 5 in FIG. 2, and is a detailed view of the locking mechanism of the front cover 5 and the back cover 6 described above. The front cover 5 can be rotated around the support shaft 5C to the position shown by the two-dot chain line, but the front cover 5 can be rotated around the support shaft 5C around the protrusion piece 15 formed on the inside of the left side surface 5b of the front cover 5. It engages with one end of the lid lock pawl 17, which can rotate, and prevents the front lid 5 from rotating. Hatching part in FIG. 12 and arrow 18 in FIG. 11
When the protrusion (not shown) that is the release member of the lid lock claw 17 enters in the direction of the arrow, the release piece 17 of the lid lock claw 17 that is biased clockwise by an elastic member (not shown)
a, and rotate the lid lock claw 17 counterclockwise. This unlocks the front lid 5 and allows it to be opened and closed freely. The square hole 19 provided on the left side surface 5b of the front lid 5 forms the optical path 12 of the light emitting element shown in FIG. 6 when the front lid 5 is open. The optical path is blocked by the left side surface 5b of the front lid 5. Both sides: Since this standard cassette is almost symmetrical, it has the same functions on the left and right sides, including closing and opening the optical path. However, the lid locking mechanism is only on one side. [0022] FIG. 139 is a perspective view of the lid opening/closing operation. In FIG. 13, the release piece 17a of the lid lock claw 17 is attached to a slide plate 2 provided on the main unit side and movable relative to the standard cassette 1.
0. The lid is intended to be unlocked by rotating it counterclockwise using the slide pin 21. [0023] FIG. 14 also shows the lid release pin 2 provided on the main device side.
2. Front lid 5. This shows a state in which the back cover 6 is opened. [0024] The operation of the reel lock 8 will be explained with reference to FIGS. 14 to 16. Reel lock 8 when standard cassette 1 is not in use
is slid forward by the lock spring 22, and the lock piece 8a at the tip of the reel lock 8 engages with the claws of the flanges 2a, 3a of the reels 2, 3. reel 2,3
The claw portions of the flanges 2a and 3a are configured so that the tape 4 rotates only in the winding direction in this state. 23
As shown in FIG. 15, the projection functions as a stopper when the reel lock 8 is urged forward by the lock spring 22. 24 is a lock guide, and its tip 24a is connected to the lock spring 2 by the reel lock 8.
2, when the lock piece 8a at the tip of the reel lock 8 is moved backward as shown in FIG.
It is forcibly separated from the claw portions a and 3a. Further, the left and right side walls of the lock guide 24 are lock guides that form sliding guides for the reel lock 8. Although not shown, the reel lock 8 is guided by front lock guides 24 on its left and right sides, its lower surface is guided by the bottom surface of the lower half of the standard cassette 1, and its upper surface is guided by the upper half. A cross-sectional view is shown in FIG. 17, and the reel lock release pin 25 is provided in the main unit, and by moving from the position shown by the imaginary line to the position shown by the solid line, the state shown in FIG. 15 changes to that shown in FIG. 2 and 3 are released from the reel lock 8 and can freely rotate. [0025] What has been described above is an overview of the standard cassette that is the basis of the present invention. This cassette has a back cover compared to existing cassettes such as the VH3 system and the Beta system, so that it has excellent complete airtightness when the cassette is not in use. Without sacrificing the excellence of the standard cassette, which is represented by its complete sealing, it is possible to miniaturize the mechanism, which cannot be achieved with current standard cassettes, to ensure compatibility with this standard cassette, and to make it a tape cassette. It is an object of the present invention to provide a cassette for short-time recording in which the start and end ends of a built-in tape can be detected by start and end end detection means comprising the same light receiving and emitting elements. [0026] FIG. 18 is a plan view schematically showing the internal structure of this short-time recording cassette (hereinafter referred to as short-time cassette), and FIG. 5 is a perspective view from the back side. Compared to the standard cassette 1, the short-time cassette 30 has almost the same external shape. Only the different parts of the configuration will be explained below. First, the reels 31 and 32 have flanges 31a and 3 because the recording time is short.
The diameter of 2a can be small. Since the flanges 31a and 32a are functionally the same except for their smaller diameters, they also have a claw portion (see FIG. 22) on the outer periphery that engages with the reel lock 33.
). The structure and operation of the reel lock 33 are shown in FIGS. 19 to 22 (XJ). Figure 22 shows reel lock 3 when the cassette is not used for a short time.
In state 3, flanges 31a, 3 are similar to standard cassette 1.
A lock pawl 33a is engaged with the pawl portion 2a. Since the diameters of the reel flanges 31a and 32a are reduced, the reel lock 33. Lock spring 34° protrusion 3
5. Although the lock guide 36 is changed in shape and position, the functions of the lock guides 36 are exactly the same. [0027] As shown in FIG. 21, the lock claw part 37 ensures that the lock claw 33a is released from the reel flanges 31a and 32a when the reel 31.32 is unlocked by the reel lock release pin 38 provided on the device side. It is forcibly bent so that it separates. [0028] FIG. 19 is a cross section taken along line CC in FIG. 22, and FIG. 20 is a cross section taken along line D in FIG.
-D cross-sectional view is shown. The reel lock 33 slides back and forth with its side surface guided by the lock guide 36, its upper surface guided by the upper half of the cassette, and its lower surface guided by the bottom surface of the lower half of the cassette. [0029] Returning to FIG. 17 again, as mentioned above, reel 3
Since the diameters of the flanges 31a and 32a of 1.32 have become smaller, the opening 39 is significantly enlarged compared to the standard cassette 1 in order to insert a post etc. inside the tape 4a stretched on the front and pull out the tape 4a. has been done. The expanded range is called the large opening because it covers the opening 7 (small opening) of the standard cassette 1 shown in FIGS. 37 and 6. Furthermore, the previously described sensor hole 11 (Fig. 39, Fig. 6, Fig. 23, 24) opened at the bottom of the standard cassette 1 is provided at a predetermined position on the front side from the position where the sensor hole 11 is opened. Stretched tape 4, 4
A recess 39a that is continuous with the opening 39 (large opening) and opened to the bottom at a corresponding position approximately perpendicularly rearward to a.
is provided. [0030] The hatching part 41 may be used for the opening 39 since the diameters of the flanges 31a and 32a are smaller, but the cassette support area by the standard cassette 1 device shown by dots in Fig. 40 is also considered. 40, so from the viewpoint of ensuring compatibility, the configuration is as shown in FIG. [C)0311 FIG. 23 is a right side perspective view of the front cover 42. Compared to the standard cassette 1, the front cover 42 of the short-time cassette 30 has a structure in which the dot 42a on the right side is cut out. This is used when it is necessary to detect the standard cassette 1 and the short-time cassette 30, which will be described later. For example, in the case of the standard cassette 1, a switch is arranged at a position resisting this notch 42a of the garage holder of the main unit, and in the case of the power plate short-time cassette 30, the switch does not operate. If you think about it, you can use it effectively. In the case of this embodiment, this switch mechanism is not shown, but
This detection is used to switch the mechanism's operation. Details will be described later. [0032] Now, what has been explained above is the short-time cassette 30. This tape cassette has all the main items necessary for the standard cassette 1, such as functions, configuration, distance between reel axes, tape stretching position, cassette external dimensions, etc. Since they have the same specifications, they are perfect in terms of compatibility.On the other hand, the tape cassette itself is a cassette that cannot be miniaturized at all. However, the purpose of the present invention is not to miniaturize the tape cassette, but to miniaturize the entire mechanism using the tape cassette, and to detect the beginning and end of the tape in a short time when using a tape cassette for long-term recording. This is possible with the same start and end detection means when using a tape cassette, and a specific example thereof will be described with reference to FIGS. 24 to 29. Note that this embodiment employs a new system that cannot be realized by the conventional concept of miniaturizing the mechanism by miniaturizing the cassette. This system uses a standard cassette for long-term recording in a single VTR, and a short-time cassette for short-term recording, which requires the same size mechanism as a standard VTR. By using this, the size of the mechanism can be greatly reduced. [0033] FIG. 24 shows 1. When trying to record for a long time using the standard cassette 1, the standard cassette 1 is set in the VTR 43. Reference numerals 44 and 45 indicate light receiving elements corresponding to the light emitting elements 46 inserted into the sensor holes 11, which form the optical paths 12 and 13 and detect the beginning and end of the tape 4. Therefore, in the cassette side wall in this optical path, lla is transparent and llb is formed with a notch. 47.48.
49, 50, 51, and 52 are rotating posts forming a tape path, 53 is a fixed post, and 54 is a pinch roller. 55 is a fixed post I., 56.57 is a rotary post 58 is an erase head, 59 is a capstan, and 60 is a tape guide drum. With the standard cassette 1 attached to the VTR 43, the loading motor (not shown) switches to ○N, and the post 47 in the opening 7 of the standard cassette 1
~53 The pinch roller 54 is the stretched tape 4a.
Pull it out and continue the loading operation until it reaches the specified position. The loading completion state is the state shown in FIG. 25. The tape 4 is wound around a tape guide drum 60 at a predetermined angle, and is then wound around a capstan 59. It is pinched by the pinch roller 54 and can be driven. Now, this VTR43 has the short-time cassette 3 of the present invention.
0 is installed, the state will be as shown in FIG. 26. Since the opening 39 of the short-time cassette 30 covers the range of the opening 7 of the standard cassette 1, the posts 47 to 53 and the pinch roller 54 can be accommodated thermally enough. The optical path connecting the light emitting element 46 and the light receiving element 44.45 is also the same as that of the standard cassette 1, and the cassette side wall 11b on the optical path is a transparent body.
Since b is a notch, it is transparent. If the standard cassette 1 is loaded to the predetermined position as in the case of the standard cassette 1, the mechanism will be exactly the same as that shown in FIG. 25, and there will be no problem between the two. This is a short time cassette 3
This means that cassette 0 is compatible with standard cassette 1. [0034] In this embodiment, when this short-time cassette 30 is used, a tape path is formed as shown in FIG. 1. The tape path centered on the tape guide drum 60 is no different from that of the standard cassette 1, but each post between the post 47 and the post 51, the capstan, and the tape guide drum are relatively close to the short-time cassette 30. , the entire tape path, including the tape guide drum 60, is briefly included in the opening 39 of the cassette 30. At this time, the light emitting element 46 that was in the center of the tape cassette before loading entered the tape guide drum 60 into the opening 39 of the tape cassette, and when the standard tape cassette 1 shown in FIGS. Sensor hole 11
, that is, the light emitting element 46 shown in FIG.
From the position shown in Fig. 26, the tape 4 stretched on the front side is
It is located approximately perpendicularly rearward with respect to a(4), and moves into a recess 39a opened in the bottom surface of the cassette 30 for a short time following the opening 39 as shown in FIG. Therefore, the optical path is also 12
a, the position and shape of the square hole 19 in the front cover 42 of the force plate short-time cassette (13a) 30 are the same as that of the standard cassette 1.
The new optical paths 12a and 13a also use the square hole 19 and the light receiving elements 44 and 45 set at the same position with respect to the tape cassette. The side wall 11c of the opening 39 of the short-time cassette 30 on this optical path is made transparent so as to be transparent, and llb is provided with a cutout like the standard cassette 1. As described above, even if the short-time cassette 30 is used and the tape guide drum 60 without the exterior is brought relatively close to the short-time cassette 30, the size of the VTR 43 can be reduced by downsizing the mechanism, but if the standard cassette 1 is adopted. It can be configured without any loss in necessary functionality. [0035] Next, FIGS. 27 to 29 show examples of the VTR mechanism for completing the tape path shown in FIGS. 25 to 1. VT
R is composed of a drive board 61, a loading board 62, and a loading guide 63 that is mounted on top of the loading board 62. [0036] The drive board 61 connects the reels 2, 3, 31 and 32 of the cassette.
a reel stand 64, 65 that engages with and drives the tape 4; element holders 66, 67 that fix the light receiving element 44, 45;
Positioning pin 68 that engages the cassette positioning hole 10.
69, cassette support area 40 in Figure 30 (Figure 30)
cassette support pins 70 and 71 that support the tape cassette, cassette information switches 72 and 73 that detect whether or not the six holes are opened or closed in correspondence with the information window 9 of the tape cassette, and a cassette information switch that is rotatable around a support shaft 74. Reel lock lever 7 equipped with reel lock release pin 25 of cassette reel lock 8, 33
5. An element lever 77 that supports the light emitting element 46 so as to be rotatable about a support shaft 76, and a post arm A80. Each of them has a post arm B81. [0037] The loading board 62 is composed of a tape guide drum 60, a capstan 59, posts 55, 56, 57, an erase head 58, a V stopper A82 for positioning the posts 49, 50, a post 51, and a pinch roller 54. V stopper B8 for positioning the pinch roller boat
3. A V stopper C84 for positioning the post 47 is provided. The pinch roller 54 is rotatable around a shaft 85. [0038] FIG. 29 shows a side view of this VTR mechanism, and the loading board 62 is supported by U-shaped board guides 86 and 87 provided on both sides of the drive board 61. It is possible to slide back and forth along 87. [0039] In a VTR having this configuration, the loading board 62 and the driving board 61 are normally locked in the positional relationship shown in FIG. 27, although not shown. [0040] When the standard cassette 1 is installed in this VTR, the loading motor (not shown) operates to move the post arm A.
, 80, the post arm B81 rotates counterclockwise and nine clockwise around the support shafts 78 and 79, and the post 47 moves along the guide groove 92 of the loading guide board 63. The other posts 49, 50, 53, 51 and the pinch roller 54 similarly move along the guide grooves 89, 90, 91. As a result, the tape path shown in FIG. 25 is completed. [0041] Now, when the cassette 30 is attached to this VTR for a short time, this cassette is different from the standard cassette 1 as shown in FIG. 23 because it has a notch in the front cover 42 so that it can be detected. It is possible to determine that the loaded cassette is the cassette 30 for a short time using a configured microswitch or the like. [0042] When this switch (not shown) is determined to be a short-time cassette (30), the above-mentioned loading board 62 and drive board 6
1 is unlocked and can be slid. Next, when the loading motor starts, the loading board 62 moves to the board guide 8 of the drive board 61 as each post moves as described above.
6.87 to the drive board side 61. When the loading board 62 is moved to a predetermined position, the loading board 62 is locked again with respect to the drive board 61, and the loading motor is stopped. At this time, each post also reaches each stopper and is positioned. [0043] The light emitting element 46 supported by the element lever 77 is normally shown in FIG.
When the loading board 62 moves, the loading guide 63 attached to the loading board 62 is moved.
It is pressed by the end 88a of the U groove 88 formed at one end of the U groove 88, and rotates clockwise about the support shaft 76. In the loading completed state, the light emitting element 46 is positioned by the V groove 61a formed in a part of the drive board 61. At the same time, the position of the light emitting element 46 with respect to the short time cassette 30 is such that it is housed in the previously described recess 39a, as shown in FIG. [0044] Even if two types of tape cassettes are used in this way, by providing and housing the recess 39a in the short-time cassette 30 in succession with the opening 39, each light path 13 can be illuminated by a single light emitting element 46. , 13a (FIG. 259, FIG. 1) makes it possible to detect the beginning and end of the tape 4. At the same time, compared to the case where each dedicated light emitting element is provided, -
When using one tape cassette, it is necessary to remove the light emitting element for the other by sinking it downwards, etc., which increases the thickness of the VTR itself, increases the number of parts, and creates a complicated mechanism. points have been resolved. Through the above operations, the mechanism is locked in the positional relationship as shown in FIG. 28, and the tape path shown in FIG. 1 is completed. [0045] When it is desired to take out the tape cassette 1 or 30, it can be easily taken out by reversing the operations described above and returning to the relationship shown in FIG. [00461] [Effects of the Invention] According to the present invention, the optical paths of the light emitting element and the light receiving element for detecting the beginning and end of the tape are formed so that three optical paths are possible in the short-time cassette, and the constituent elements of the same start and end end detection means are formed. For example, even if the light emitting element is moved to the rear of the cassette, the beginning and end ends can be detected in the same way. If the light emitting element can be moved rearward, there will be no restriction on the amount of entry of the guide drum due to the light emitting element being in the front, and the range of the opening into which the guide drum can enter will be increased. [0047] If the short-time cassette forms three optical paths, including the optical path common to the long-time cassette, the short-time cassette can be attached to a conventional VTR exclusively for long-time cassettes, and the beginning and end can be detected. It becomes possible to ensure mutual compatibility of different types of tape cassettes. As a result, instead of a conventional VTR that only uses short-time cassettes, a VTR that can be used for both short-time and long-term use can be configured, and if a short-time cassette is attached to the VTR, the light emitting element can be moved to the rear of the cassette, and the guide drum can be moved to the rear of the cassette. The mechanism can be downsized by entering deeply into the tape cassette opening. Furthermore, if the cassette is mounted for a long period of time, the light emitting element can be positioned in front of the cassette, and the beginning and end of the tape can be detected using the optical path of a conventional long-duration cassette. At this time, the amount of advance of the guide drum is smaller than that of a short-time cassette, so the size of the mechanism becomes larger than when a short-time cassette is installed, and the mechanism becomes the smallest size that can be obtained with a long-time cassette.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a state in which loading is completed in a short-time recording tape cassette according to an embodiment of the present invention.

FIG. 21 is a top perspective view of a standard cassette in one embodiment of the present invention. FIG. 3 is a rear perspective view of the standard cassette.

[Figure 4] It is a sectional view of the same standard cassette.

FIG. 5 is a rear perspective view of a short-time recording tape cassette according to an embodiment of the present invention.

[Figure 6] FIG. 3 is a plan view showing the standard cassette of FIG. 2 in use.

[Figure 7] It is a side view of the same standard cassette.

FIG. 8 is a sectional view for explaining opening and closing of the front cover and back cover of the tape cassette in the embodiment of the present invention.

FIG. 9 is a cross-sectional view for explaining opening and closing of the front and back covers of the tape cassette in the embodiment of the present invention.

FIG. 10 is a sectional view for explaining opening and closing of the front and back covers of the tape cassette in the embodiment of the present invention.

FIG. 11 is a cross-sectional view for explaining the lid locking and lid opening of the tape cassette in the embodiment of the present invention.

FIG. 12 is a cross-sectional view for explaining the lid locking and lid opening of the tape cassette in the embodiment of the present invention.

FIG. 13 is a perspective view for explaining the lid locking and lid opening of the tape cassette in the embodiment of the present invention.

FIG. 14 is a perspective view for explaining the lid locking and lid opening of the tape cassette in the embodiment of the present invention.

FIG. 15 is a diagonal plan view illustrating a reel locking operation in the case of a standard cassette in an embodiment of the present invention.

FIG. 16 is a plan view for explaining a reel locking operation in the case of a standard cassette in an embodiment of the present invention.

FIG. 17 is a sectional view for explaining a reel locking operation in the case of a standard cassette in an embodiment of the present invention.

FIG. 18 is a plan view of a short-time recording tape cassette in an embodiment of the present invention.

FIG. 19 is a cross-sectional view for explaining a reel locking operation in the short-time recording tape cassette according to the embodiment of the present invention.

FIG. 20 is a sectional view for explaining the locking operation in the case of the short-time recording tape cassette according to the embodiment of the present invention.

FIG. 2 is a plan view for explaining the reel locking operation in the short-time recording tape cassette according to the embodiment of the present invention. FIG. 22 Tape force set I for short-time recording in the embodiment of the present invention.
FIG. 3 is a plan view for explaining a reel locking operation in the case of FIG.

[Figure 23] It is a front lid perspective view of the same short-time recording tape cassette.

FIG. 24 is a plan view of the standard cassette according to the embodiment of the present invention installed in a VTR.

FIG. 25 is a plan view showing a state in which tape loading is completed in the same standard cassette.

FIG. 26 is a plan view of the short-time recording tape cassette according to the embodiment of the present invention installed in a VTR.

FIG. 27 is a plan view of a VTR using a cassette before loading.

[Figure 28] FIG. 3 is a plan view of the VTR after loading has been completed.

[Figure 29] It is a side view of a VTR.

[Figure 30] It is a back view of a standard cassette.

FIG. 31 is a plan view showing a tape cassette in the conventional VH3-C system.

FIG. 32 is a plan view showing a conventional 374-inch tape cassette.

[Explanation of symbols]

11b Cassette side wall 11c Side wall 12a Optical path 13a Optical path 19 square hole 30 Short time cassette 31 Reel 32 reel 39a Recessed part 44 Photo-receiving element 45 Photo receiving element 46 Light emitting element

【Document name】

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Claims (1)

[Claims] Claims: 1. A take-up reel and a supply reel, each having a transparent start and end tape formed at both ends of a magnetic tape, are housed in a casing part at a predetermined distance apart, and the casing part includes: A tape cassette in which a plurality of optical paths formed by light-transmitting holes or transparent light-transmitting members are formed across the running path of the magnetic tape in order to detect one of the starting and ending tapes.