JPS6020222Y2 - magnetic tape cartridge - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic tape cartridge case, and more particularly to a magnetic tape cartridge that can optically detect the edge of the magnetic tape.

In this type of magnetic tape cartridge, transparent leader tapes are connected to both ends of the magnetic tape.

The bottom surface of the cartridge case is provided with an insertion hole for inserting the light source, and the side wall of the cartridge case is provided with a transparent portion for allowing the emitted light from the light source to pass through.

On the other hand, the recording and reproducing apparatus is provided with an end detection means having a light source and a light receiving section, and when a magnetic tape cartridge is installed in this recording and reproducing apparatus, the magnetic tape runs between the light source and the light receiving section. It is supposed to be done.

Then, as the recording/reproducing operation is performed, the leader tape and the magnetic tape pass between the light source and the light receiving section in order, and when the leader tape passes, the emitted light from the light source passes through the data tape and is received by the light receiving section, and then passes through the magnetic tape. Sometimes, the emitted light is blocked by the magnetic tape and is not received by the light receiving section.

The optical change caused by the transmission and blocking of such radiation light is detected by the presence or absence of an output signal from the light receiving section, thereby providing a mechanism for detecting the beginning and end of the magnetic tape.

On the other hand, the magnetic tape cartridge is provided with a window made of a transparent synthetic resin plate so that the amount of winding of the magnetic tape can be viewed from the outside.

Therefore, in conventional magnetic tape cartridges, the light receiving section may receive external light that enters the cartridge case through the window, and even when the magnetic tape passes between the light source and the light receiving section, the light receiving section sends a light reception signal. was output, causing malfunction.

The purpose of the present invention is to eliminate such drawbacks of the conventional technology,
To provide a magnetic tape cartridge capable of accurately detecting tape ends.

In order to achieve this object distantly, the present invention provides a reel winding amount of the magnetic tape on, for example, the upper surface of a cartridge case that houses a magnetic tape whose end portion is made of polyester film or the like and has a translucent adhesive tape connected thereto. The cartridge case is provided with a window made of a transparent synthetic resin plate that can be seen through from the outside, and an insertion hole for inserting either the light source or the light receiving part of the end detection means, which is equipped with a light source and a light receiving part, is provided in the cartridge case. For example, a light-transmitting part may be formed on the bottom of the cartridge case and on a peripheral wall such as a side wall of the cartridge case to allow the emitted light from the light source to pass through, so that when the magnetic tape cartridge is installed in a recording/reproducing device, there is a gap between the light source and the light-receiving part. In a cartridge case in which a magnetic tape is installed in advance in a cartridge case so that the magnetic tape crosses a light transmission path formed in the window, outside light entering the cartridge case through the window is prevented from entering the light transmission path. The cartridge case is characterized by a light-blocking wall provided inside the cartridge case.

Next, embodiments of the present invention will be described in detail.

A cartridge case is composed of a lower case 1 and an upper case 2, and a rotary member M3 is rotatably supported on the front side of the cartridge case, and these lower case 1, upper case 2, and rotary lid 3 are Both are molded from synthetic resin.

At approximately the center of the lower case 1, two drive shaft insertion holes 4 are bored at a predetermined interval, as shown in FIGS. 4 and 6.

Above the drive shaft insertion hole 4, a pair of glue wheels 6 for winding the magnetic tape 5 are arranged, respectively.

On the outer periphery of reel 6, there is a front inner wall with a slight gap. A,
7B and rear inner walls 8A, 8B, and 8G are provided, and these inner walls 7 and 8 are formed integrally with the lower case 1.

The front inner walls 7A, 7B are connected to each other and also to the front walls 9A, 9B, 9C.

In FIG. 4, the rear inner walls 8A and 8C at the left and right ends are connected to the side wall 10 and rear wall 11 of the lower case 1, and the rear inner wall 8B at the center is connected to the rear wall 11, respectively.

The central rear inner wall 8B is higher than the rear wall 11, and when the lower case 1 and the upper case 2 are joined, the upper end of the rear inner wall 8B extends to near the inner surface of the upper case 2.

An erroneous erasure prevention piece 13 is integrally formed on the bottom surface of the lower case 1 so as to face the inside of the chamber 12B defined by the rear inner wall 8B and the rear wall 11 at the center.

As shown in FIG. 7, the root portion of the accidental erasure prevention piece 13 is slightly thinner and can be easily separated from the lower case 1.

When the accidental erasure prevention piece 13 is folded up, it is separated from the lower case 1 and stored in the chamber 12B, so that the magnetic tape 5 is not damaged by the accidental erasure prevention piece 13 separated from the lower case 1, and the rotation of the reel 6 is prevented. There is no need for support.

Inside the chamber 12A defined by the left rear inner wall 8A, the side wall 10, and the rear wall 11, a screw tightening boss portion 14A and a pivot shaft 15A protrude, and a slightly elongated reference pin insertion hole 16A is provided.
is open toward the lower surface of the lower case 1, and an arcuate guide groove 17A centered on the pivot 15A is formed on the upper surface of the lower case 1.

On the other hand, a chamber 12B defined by the rear inner wall 8C, the side wall 10, and the rear wall 11 on the right side has a boss portion 14B, a pivot 15B, a protruding circular reference pin insertion hole 16B, and an arc-shaped reference pin insertion hole 16B. A guide groove 17B is formed, which is connected to the left boss portion 1.4A, the pivot shaft 15A, and the reference pin insertion hole 16A.
, and are arranged symmetrically with the guide R17A.

A rotation stopper member 18B is rotatably fitted to the pivot 15B.

The rotation stopper 18B is made of synthetic resin with a small coefficient of friction 1, and includes a sleeve 19B that fits around the pivot shaft 15B, a receiving portion 20B extending in one direction from the outer periphery of the sleeve 19B, and a receiving portion 20B provided at the tip of the receiving portion 20B. 21B.

The lower end of the claw portion 21B protrudes slightly from the lower ends of the sleeve 19B and the receiving portion 20B, so that when the rotation stopper 18B is fitted to the pivot shaft 15B, the lower end of the claw portion 21B protrudes slightly from the lower ends of the sleeve 19B and the receiving portion 20B.
It is meant to go inside.

With the rotation stopper 18B pivotally attached to the pivot 15B,
A bent portion 22B having a dogleg shape in plan view is provided in a portion of the receiving portion 20B that faces the reference pin insertion hole 16B.

Moreover, the inside of the lower end of the receiver 20B has an inclination angle of about 30 to
An inclined portion 23B of about 60 degrees is formed.

The rotation stopper 18A pivotally connected to the left pivot 15A is the first rotation stopper member 18A.
As shown in Figure 0, the aforementioned right rotation stopper member 18B
It has a symmetrical shape with the sleeve 19A.
It consists of a receiving part 20A and a claw part 21A, and a bent part 22A is provided at the middle part of the receiving part 20A, and an inclined part 2 is provided at the lower end.
3A is formed.

A spring member 24B made of a coil spring is loosely fitted onto the pivot shaft 15B from above the rotation stopper 18B.

As shown in FIG. 8, this spring member 24B has an annular part 25 formed by multiple windings in the middle, and both ends extending from the annular part 25 are bent in the same direction as the height direction of the annular part 25. Resilient contact ends 26A and 26B are formed.

With the elastic contact ends 26A and 26B pressed against each other slightly against the elasticity of the spring member 24B, the annular portion 25 is loosely fitted into the head of the pivot shaft 15B, and both elastic contact ends 26A and 26B are pushed against the side wall. 10 and the receiving part 2OB, and then release the elastic contact ends 26A and 26B.

Then, the resilient end 26A of the spring member 24B is resiliently engaged with the outer surface of the receiving portion 20B, and the resilient end 26B is elastically engaged with the inner surface of the side wall 10, and the spring member 24B engages the claw portion 21B of the rotation stopper member 18B. is elastically biased toward the reel 6 side.

With this structure, the spring member 24 can be easily mounted and supported.

As shown in FIG. 11, the reel 6 is composed of a lower flange 28 and an upper flange 29 from which a bub 27 is integrally provided.

The lower flange 28 is made of opaque synthetic resin, and has a large number of tooth grooves 30 at predetermined intervals around its outer periphery.
is formed.

As shown in FIGS. 12 and 14, the outer circumferential portion of the bub 27 is formed with a concave tape fitting portion 31 that is open toward the outer circumferential surface of the bub 27.

One or more tape clamping parts 32 are protruded from the bottom of the tape fixing piece fitting part 31, and locking protrusions 33 are formed on both sides.

On the other hand, a tape fixing piece 34 (fourteenth
(see figure) has a flat lower end surface 35 at least in the portion facing the tape clamping part 32, and elastic protrusions 36 having some flexibility are provided on both sides of the lower end surface 35. .

Therefore, when the tape fixing piece 34 is pushed into the tape fixing piece clamping part 31 through the end of the magnetic tape 5, the elastic protrusions 36 on both sides are pressed inwardly and deformed while climbing over the respective locking protrusions 33. Then, the tape fixing piece 34 fits into the tape fixing piece clamping part 31.

Once the tape fixing piece 34 is fitted in this way, the stopper action of the locking protrusion 33 causes the tape fixing piece 34 to
will not come off from the tape fixing piece clamping part 31.

Then, the magnetic tape 5 is moved between the tape clamping part 32 and the lower end surface 35 of the tape fixing piece 34 by pushing the tape fixing piece 34 into place.
and between the elastic protrusion 36 and the locking protrusion 33 due to the elastic force of the elastic protrusion 36, so that the end of the magnetic tape 5 is locked to the bub 27.

As shown in FIGS. 11 and 12, a welding protrusion 37 for fixing the upper flange 29 to the bub 27 and a central protrusion 38 of the reel 6 are provided on the upper part of the bub 27.

On the other hand, the upper flange 29 made of transparent synthetic resin has protrusion insertion holes 39 into which the welding protrusions 37 and the center protrusion 38 are inserted.

(See Figure 11).

The fusion protrusion 37 and the central protrusion 38 are inserted into the protrusion insertion hole 39, respectively.
The upper flange 29 is fixed to the bub 27 by thermally melting the upper end of the welding protrusion 37.

The central protrusion 38 passes through the protrusion insertion hole 39 and projects from the upper flange 29.

As shown in FIG. 13, a drive shaft insertion recess 40 for inserting a drive shaft of a recording/reproducing device is formed on the underside of the bub 27, and a drive shaft insertion recess 40 for transmitting driving force is formed on the circumferential surface of the drive shaft insertion recess 40. A plurality of locking protrusions 41 are provided at predetermined intervals.

By placing the reel 6 in a predetermined position on the lower case 1, the second
As shown in the figure, the drive shaft insertion recess 40 is arranged above the drive shaft insertion hole 4 of the lower case 1.

Next, stopping and releasing the rotation of the reel 6 will be explained.

As described above, the reel 6 is placed at a predetermined position on the upper case 1, and the rotation stopper member 18 and the spring member 24 are respectively attached to the pivot shaft 15.
The claws 21 of the rotation stopper 18 are fitted into the outer tooth grooves 30 of the reel 6 by using the elasticity of the spring member 24.
The rotation of the reel 6 is stopped by fitting into the reel 6, and the bent portion 22 provided in the receiving portion 20 of the rotation stopping member 18 is located above the reference pin insertion hole 16.

This state is shown in FIGS. 4, 9, and 15, respectively.

(Magnetic tape car) When inserting the IJ screw into the recording/reproducing device and lowering it, the tip of the reference pin 42 (see FIGS. 9 and 16) protruding from the recording/reproducing device will fit into the reference pin insertion hole 16. It passes through and abuts against the lower end of the receiving portion 20 in the rotation stopper member 18 .

Since the lower end of the receiving part 20 is provided with the inclined part 23, the pushing up of the reference pin 42 causes the receiving part 20 to move up against the spring member 24.
The rotation stopper 18 is pushed away against the elasticity of the lower case 1, thereby rotating the rotation stopper 18 about the pivot 15 toward the rear wall 11 of the lower case 1.

With this rotation, the claw portion 21 is rotated by the outer circumferential tooth groove 3 of the reel 6.
0, and the reel rotation stop is released (16th
(see figure).

By providing the bent portion 22 in a portion of the receiving portion 20 that is symmetrical to the reference pin insertion hole 16, the rotation stopper 18 can be smoothly and reliably engaged with the reference pin 42.

Also, the reference pin 42 is connected to the reference pin insertion hole 16 of the lower case 1.
By being inserted into A and 16B, the magnetic tape cartridge is placed at a predetermined position (reference position) of the recording/reproducing device.
will be installed in

At this time, the left and right rotation stoppers 18A, 18B are brought into elastic contact with the outer circumferences of the respective reference pins 42 due to the elasticity of the spring member 24, so that the positioning of the magnetic tape cartridge becomes more reliable.

When taking out the magnetic tape cartridge from the recording and reproducing apparatus, the reference pin 42 comes out of the reference pin insertion hole 16, so the rotation stopper 18 is rotated toward the reel 6 by the restoring force of the spring member 24, and the claw portion 21 is rotated again. is fitted into the outer peripheral tooth groove 30 of the reel 6, and the rotation of the reel 6 is stopped.

In this embodiment, the receiving portion 20 of the rotation stopper 18 is provided with a bent portion 22 having a dogleg shape in plan view, but other bent portions having a substantially Ω-shaped plan view may also be provided.

Further, in the embodiment, the inclined portion 23 is provided over almost the entire length of the lower end of the receiving portion 20, but the inclined portion 23 may be provided only at the bent portion 22 and the lower end in the vicinity thereof.

As shown in FIG. 3, FIG. 5, and FIG. ) is provided with an erroneous insertion prevention piece fitting groove 43 into which the piece is fitted.

In order to provide the one-piece fitting groove 43 to prevent incorrect insertion, a mountain-shaped protuberance 44 is formed at the bottom of the lower case 1.

The portion of this raised portion 44 that protrudes forward from the front wall 9B is
It serves as a support protrusion to prevent the magnetic tape 5 from sagging, and when the magnetic tape 5 is stopped, the middle portion of the magnetic tape 5 extending along the front surface of the magnetic tape cartridge is slightly lifted by the raised portion 44. (See Figures 3 and 17).

At the rear of the front wall 9B of the raised portion 44, two bearing ridges 45 extending substantially parallel to the front wall 9B are protruded.
A groove-shaped bearing portion 46 is formed on the upper surface of the shaft 5, and a lock lever 47 is rotatably mounted between the bearing projections 45.

Further, a release pin insertion hole 48 having a slightly elongated hole shape is bored near the raised portion 44 .

The lock lever 47 is molded from synthetic resin,
As shown in FIG. 18, FIG. 19, and FIG. 20, a rotating pin 49 is protruded from approximately the center of each side surface, and this rotating pin 49 is fitted into the bearing portion 46 of the supporting bulge 45. Ru.

Since the depth of the bearing portion 46 is designed to be approximately the same as the diameter of the pivot pin 49, the pivot pin 49 is accommodated within the bearing portion 46 without protruding from the upper surface of the support ridge 45.

Two bearing ridges 62 are also protruded from the inner surface of the upper case 2 so as to face the bearing ridges 45 of the lower case 1.
(See FIG. 30), the lower surface of this bearing jetty 62 is flat.

By joining the lower case 1 and upper case 2,
The pivot pin 49 is rotatably supported between the bearing projections 45 and 62 (see FIG. 19).

The lock lever 47 is integrally formed with a pressing portion 50 that is stepped down in front of the pivot pin 49 and extends to the upper end opening of the release pin insertion hole 48 .

On the other hand, behind the rotation pin 49 of the lock lever 47,
A stopper portion 51 is provided that projects upward.

A leaf spring 63 bent into an accordion shape is inserted between the stopper portion 51 of the lock lever 47 and the retreated portion of the front wall 9B.

Due to the pressing force of the plate spring 63, the lock lever 47 is elastically biased by the pressing portion 50 in a direction to close the release pin insertion hole 48.

In addition, the stopper part 51 of the lock lever 47 and the leaf spring 6
The joint portion 3 is slidable, and the stopper part 51 can be pushed down onto the leaf spring 63 while compressing the leaf spring 63.

This lock lever 47 prevents the rotating lid (opening) disposed on the front side of the cartridge case consisting of the lower case 1 and the upper case 2, and prevents the rotating lid 3 from closing the front surface of the magnetic tape cartridge. Used for locking.

As shown in FIGS. 21, 22, and 23, the rotating lid 3 is composed of a front plate 52, a top plate 53, and end plates 54 on both sides. A pin 55 and a second pivot pin 56 are provided on the right end plate 54 and project inward, respectively.

By fitting these second pivot pins 55 and 56 into support holes 57 (see FIG. 36) protruding from both sides of the upper case 2, the rotation M3 is rotatably supported by the upper case 2. Ru.

Further, the rotating lid 3 has a first pivot pin 5 as shown in FIG.
5, and is always elastically biased in the closing direction by a coil spring 65 whose one bent end 64A is fixed to the rotating lid 3 and the other bent end 64B is fixed to the upper case 2.

As shown in FIGS. 2 and 21, an erroneous insertion prevention piece fitting notch 58 is formed at the lower end of the front plate 52 and in a portion facing the erroneous insertion prevention piece fitting groove 43 of the lower case 1. ing.

Also, on both sides of the lower end of the front plate 52, there are stoppers (
A stopper fitting notch 59 into which a stopper (not shown) is fitted is formed respectively.

As shown in FIGS. 22 and 23, the top plate 53
A hook-shaped hanging portion 60 is provided protruding from a side end of the lock lever 47 at a position facing the lock lever 47 .

As shown in FIGS. 1 and 25, this hanging portion 60 is
It passes through a hanging part insertion hole 61 formed in the upper case 2 and extends toward the stopper portion 51 of the lock lever 47 .

Next, the order of operation of the rotating lid 3 and the lock lever 47 will be explained.

FIG. 18, FIG. 19, FIG. 25, and FIG. 27 are diagrams for explaining the state when the rotating lid 3 is closed.

Due to the pressing force of the leaf spring 63 as described above, the lock lever is
The opening of the release pin insertion hole 48 is covered by the pressing portion 50 of 47.

As shown in FIG. 25, the stopper portion 51 is disposed forward in the rotational direction of the hanging portion 60 of the rotating lid 3 to prevent the hanging portion 60 from rotating.

Therefore, due to the engagement between the stopper part 51 and the hanging part 60,
The rotating lid 3 is held in a state where it will not open even if external force is applied.

When a magnetic tape cartridge is inserted into a recording/reproducing apparatus and then lowered, the release pin 66 (see FIG. 19) is first inserted from the release pin insertion hole 48 and presses against the pressing portion 50 against the elasticity of the leaf spring 63. Push up to lock the lever.
47 rotates clockwise around a rotation pin 49 as shown by the arrow in FIG.

With this rotation, the leaf spring 63 is compressed, and the stopper portion 51 descends toward the lower case 1 as shown in FIGS. 25 and 26.

By this lowering, the stopper part 51 is disengaged from the hanging part 60, moves out of the rotation path of the hanging part 60, and the rotating lid 3 can be rotated (opened).

Next, as shown in FIG. 27, the inclined side provided on the end plate 54 of the rotary lid 3 is pushed up by the opening piece 67, and the coil spring 65, which biases the rotary lid 3 in the closing direction, is pushed up. Rotation M3 can be opened against elasticity.

The open state of the rotating lid 3 is shown in broken lines in FIG.

Note that flat portions 102 are provided at both left and right ends of the lower surface of the rotating lid 3 to ensure that the opening piece 67 pushes up the rotating lid 3 and opens it.
A recessed hole 101 is formed in the center of the flat part 102 to the vicinity of the top plate 53 in order to prevent the end plate 54 constituting the flat part 102 from warping due to shrinkage during molding. It is formed.

When closing and locking the rotating lid 3, the opening operation is completely opposite to the above-mentioned opening operation, and the opening piece 67 first separates from the end plate 54, and then, due to the restoring force of the coil spring 65, the rotating M3 moves in the closing direction. Rotate.

Next, the release pin 66 is removed from the release pin insertion hole 48, and the restoring force of the leaf spring 63 causes the stopper part 51 to move to the hanging part 60.
is pushed up forward in the rotational direction and comes into contact with the hanging portion 60, while the pressing portion 50 closes the opening of the release pin insertion hole 48, thereby completing the locking operation.

Note that the side surface 6 that comes into contact with the hanging portion 60 of the stopper portion 51
8 may be sloped or rounded to make it easier for the stopper portion 51 to enter the hanging portion 60 forward in the direction of rotation.

In this embodiment, a leaf spring 63 is attached to the back of the stopper part 51.
However, a spring member such as a coil spring may be interposed between the pressing portion 50 and the upper case 2 to elastically bias the pressing portion 50 toward the release pin insertion hole 48 side.

As shown in FIGS. 2 and 4, a circular through hole 69 is formed on the front side of the lower case 1 at a predetermined distance from the release pin insertion hole 48.

A pair of auxiliary positioning pins (not shown) can be inserted into the release pin insertion hole 48 and the through hole 69 to mount the magnetic tape cartridge in a predetermined position in the recording/reproducing apparatus. There is.

As shown in FIG. 4, bosses 14C and 14D for screw tightening are provided at both ends of the front surface of the lower case 1, and a similar boss portion 14 is located approximately in the center of the front surface in front of the joint between the front inner walls 7A and 7B.
E is provided protrudingly.

Hollow pins 70 are fitted onto the boss portions 14C and 14D, respectively, and also serve to support the hollow pins 70 used as tape guides.

An inter-light source insertion hole 72 is provided behind the hollow pin 70 into which a light source tube 71 for detecting the start and end ends of the magnetic tape 5 is inserted.

In addition, as shown in FIG. 30, the upper case 2 has a lower case 1.
The light source tube insertion recess 7 is located at a position facing the inter-light source insertion hole 72.
3 are provided respectively.

A semicircular light-transmitting portion 75 is provided in a portion of the side wall 10 of the lower case 1 facing the inter-light source insertion hole 72 and a portion of the side wall 74 of the upper case 2 facing the light source tube insertion recess 73, respectively. As shown in FIG.
is formed.

When the magnetic tape cartridge is installed in the recording/reproducing device, the light source tube 71 is inserted into the light source tube insertion recess 7 from the inter-light source insertion hole 72.
3, and a light receiving section 76 equipped with a photodiode is arranged on the side surface of the magnetic tape cartridge, facing the light source tube 71 (see FIG. 4).

The magnetic tape 5 extends in a direction crossing between the light source cylinder 71 and the light receiving section 76, and a transparent leader tape (made of polyester film) is provided at the starting and ending ends of the magnetic tape 5.
(not shown) are connected.

In FIG. 4, the starting end of the magnetic tape 5 is connected to the light source 71 inserted through the light source insertion hole 72 on the left side and the light receiving section 76, while the light source tube 71 inserted through the light source insertion hole 72 on the right side
The end of the magnetic tape 5 is detected by the light receiving section 76 and the light receiving section 76, respectively.

That is, the starting end of the magnetic tape 5 is determined by detecting the optical change from transmission to blocking of the radiation light irradiated toward the leader tape and the magnetic tape 5 by the light receiving unit 76, and in the case of the trailing end of the magnetic tape 5. , is detected by capturing an optical change in the contrast light from being blocked to being transmitted by the light receiving unit 76.

In order to accurately detect the start and end of the magnetic tape 5 using this optical stage without noise, this magnetic tape cartridge is designed as follows.

The first is that a part of the sensor (the light source tube 71 and the light receiving part 76) is divided into two parts, one for detecting the start end and the other for detecting the end, respectively.

Second, in order to shorten the optical path distance from the light source tube 71 to the light receiving section 76 as much as possible, the inter-light source insertion hole 72 is inserted into the side wall 10.
It was installed near the.

The third is the light source insertion hole 72 and the light source tube insertion recess 7.
By leaving a part of the side facing the light-transmitting part 75 of No. 3 and standing the light-shielding peripheral wall 77 in the other part, dispersion of the emitted light was avoided and directivity was imparted.

Fourthly, in order to eliminate the influence of external light entering through the window 78 provided in the upper case 2 for detecting the amount of magnetic tape winding, the front inner walls 7A and 7B of the lower case 1 are connected to the side walls 10 and 10.
and the front inner walls 79A, 7 of the upper case 2.
9B are each continuously extended to near the side wall 74,
External light entering through the window 78 is blocked from reaching the light receiving section 76.

The fifth is a pin-shaped first guide member 80 and a roller-shaped second guide between the hollow pin 70 serving as one of the guide members of the magnetic tape 5 and the reel 6 along the running direction of the magnetic tape. members 81 are sequentially provided, and the magnetic tape 5 is connected to the first guide member 80, the second guide member 81, and the hollow pin 70.
(third guide member), and the magnetic tape 5 is inserted into the inter-light source insertion hole 72 by the middle second guide member 81.
The light source tube 71 is guided close to the outer periphery of the light source tube insertion recess 73 to shorten the distance between the light source tube 71 and the magnetic tape 5 as much as possible.

In particular, by passing the magnetic tape 5 in a meandering manner between the first guide member 80, the second guide member 81, and the hollow pin 70 over a relatively short distance, the light source tube insertion hole 72 Sagging in the vicinity can be prevented, and the end of the magnetic tape 5 can be accurately detected at the same time as the magnetic tape 5 starts running.

In this embodiment, a pin-shaped one was used as the first guide member 80, a roller-shaped one was used as the second guide member 81, and a hollow pin 70 was used as the third guide member.
The shape of the guide member is appropriately selected depending on the tension applied to the magnetic tape 5 when it runs, and the key point is that the arrangement of each guide member and the manner in which the magnetic tape 5 is hung therebetween have characteristics.

In the embodiment, the front inner walls 7A, 7B, and 79 serve as light shielding members.
A and 79B are provided in the lower case 1 and the upper case 2, respectively, but either one of the cases may be provided with a front inner wall extending close to the inner surface of the other case.

As shown in FIG. 4, the boss portion 14E of the lower case 1, unlike the other boss portions 14A-D, is disposed between the reels 6 and has a relatively short distance from the reel 6.

Therefore, the synthetic resin shavings generated when the tapping screw 82 is screwed in to join the lower case 1 and the upper case 2 enter the inside of the cartridge case through the gap between the joint of the lower case 1 and the upper case 2. The magnetic tape 5 may be damaged due to the intrusion of this shavings.

In order to eliminate such a problem, the front inner walls 7A and 7B are continuously extended toward the reel 6 side of the boss portion 14E.
E is provided in a chamber 83 defined by the front inner walls 7A, 7B and the front wall 9B, and the reel 6 is
Isolate from the side.

By looking at the difference in the amount of magnetic tape winding between the reel 6 on the feeding side and the reel 6 on the take-up side, it is possible to more accurately grasp the usage condition of the magnetic tape 5, as well as the number of parts of the window 78 and the adhesion to the case 2. In order to reduce the number of steps and design requirements, as shown in FIGS. 29 and 30, a window 78 made of one relatively long transparent synthetic resin plate that spans both reels 6 is installed in the upper case 2. It is set in.

Conventionally, a window for viewing the amount of tape winding on the feed-out reel and a window for viewing the amount of tape winding on the take-up reel were provided separately.
A presser spring for the reel press was fixed to the inner surface of the upper case between the windows, but for the reasons mentioned above, the window 7
If 8 is reduced to one, it is necessary to change the installation position of the presser spring 84.

Therefore, in this embodiment, as shown in FIG.
4 was installed between the window 78 and the rear wall 85 of the upper case 2.

The presser spring 84 is used to press the reel 6 to the lower case 1 side when the magnetic tape cartridge is not in use.
For example, it is made of a stainless steel thin plate, and has a substantially U-shaped planar shape as shown in FIGS. 87 are provided.

A flat portion 88 is formed on the holding portion 87 and comes into contact with the tip of the central protrusion 38 of the reel 6.

As shown in FIG. 30, a recess 89 is formed on the inner surface of the upper case 2 facing the presser spring 84 in order to increase the permissible range of vertical movement of the presser spring 84.

FIGS. 34 and 35 are diagrams showing modified examples of the presser spring 84, in which the planar shape of the presser spring 84 is substantially square-shaped.

As described above, since the presser spring 84 is installed between the window 78 and the rear wall 85 of the upper case 2, the central rear inner wall 8B for regulating the position of the reel 6 cannot be provided on the upper case 2 side. As mentioned above, it is provided on the lower case 1 side.

Therefore, especially the central part of the rear wall 85 of the upper case 2 is weak in impact resistance, and the central part of the rear wall 85 is easily deformed when the upper case 2 is molded in a mold and taken out. As shown in FIGS. 30 and 31, reinforcing ribs 90 are integrally formed inside the rear wall 85.

In addition, in order to increase the impact resistance of the boss portion 14E or the light-shielding peripheral wall 77 of the lower case 1 and upper case 2, and to prevent deformation when taking them out from the mold, reinforcing ribs 9 are provided, respectively.
0 is integrally formed.

Furthermore, by providing the reinforcing ribs 90, the fluidity of the synthetic resin within the mold during molding is improved.

Next, the assembly order of the magnetic tape cartridge will be explained.

A feed reel 6 and a take-up reel 6 are installed in the lower case 1, and the magnetic tape 5 is placed in a predetermined state.

Then, the upper case 2 is placed on top of it (see FIG. 36), and the lower case 1 and the upper case 2 are joined with tapping screws 82.

In addition, the winding part 91 of the coil spring 65 for elastically biasing the rotating lid 3 in the closing direction is loosely fitted into the first pivot pin 55 of the rotating lid 3.

As shown in FIG. 38, the coil spring 65 has a winding part 91 in the middle, and its ends protruding from both sides extend horizontally to opposite sides, and both of their tips are bent downward. Ends 64A and 64B are formed.

As described above, the winding portion 91 is first attached to the coil spring 65.
The pivot pin 55 is loosely fitted, one bent end 64A is fitted into the locking hole 92A provided at the end of the top plate 53 of the rotating lid 3, and the other bent end 64B is fitted against the elasticity of the coil spring 65. and lift it upward.

In this state, as shown in FIG. 37, the first pivot pin 55 of the rotating lid 3 is fitted into the support hole 57 provided in the side wall 74 of the upper case 2, and the other bent end 64B of the coil spring 65 is pushed upward. Locking hole 92 provided on the top surface of case 1
B (see Figures 29 and 38).

Next, while slightly bending the rotating lid 3, insert the second pivot pin 5.
6 is fitted into the other support hole 57 provided in the side wall 74 of the upper case 2.

In order to facilitate insertion of the second pivot pin 56, the rotating lid 3 is made of acrylonitrile-butadiene-styrene copolymer resin (AS resin) or acrylonitrile-butadiene-styrene copolymer resin (ABS resin). It is made from acrylonylylic resin to give it flexibility,
As shown in FIGS. 39 and 40, a fitting guide groove 93 can be provided from the edge of the side wall 73 of the upper case 2 toward the support hole 57.

As shown in FIG. 40, the insertion guide groove 93 has an inclined bottom so that the end edge side of the side wall 73 is deeper than the support hole 57 side.

By fitting this second pivot pin 56 into the support 57,
A hanging portion 60 protruding from the rotating lid 3 is inserted into the cartridge case through a hanging portion insertion hole 61 provided in the upper case 2.

In this manner, the rotation M3 is rotatably supported by the upper case 2, and the elastic force of the coil spring 65 biases the rotation lid 3 in the closing direction, completing the assembly of the magnetic tape cartridge.

In addition, in order to securely hold the coil spring 65 installed from the rotating lid 3 to the upper case 2 in a predetermined position without protruding from the rotating M3 or the upper surface of the upper case 2, a coil spring 65 is installed near each of the locking holes 92A and 92B. are each provided with a housing groove 94.

Since nothing is protruding from the outer peripheral surfaces of the pivot pins 55 and 56, after the lower case 1 and the upper case 2 are joined as described above, they can be respectively fitted into the support holes 57 of the cartridge case. .

As shown in FIG. 3, when the magnetic tape cartridge is not in use, the approximately central portion of the magnetic tape 5 exposed at the front of the cartridge case is slightly raised by the chevron-shaped protuberance 44 provided on the lower case 1. This helps prevent the magnetic tape 5 from sagging.

When a magnetic tape cartridge is installed in a recording/reproducing device, the reel 6 is inserted into the drive shaft insertion recess 40 of the reel 6, and the drive shaft lifts the reel 6 slightly upward against the elasticity of the presser spring 84. Since the magnetic tape 5 also moves upward, the lower end of the magnetic tape 5 forms a raised portion 44.
move away from

When the magnetic tape 5 runs along the front surface of the cartridge case, there is a tendency for the magnetic tape 5 to move up and down considerably, especially at the center. This enables stable tape running and reduces damage to the edges of the magnetic tape due to shaking.

In the above embodiment, a light source insertion hole is provided in the cartridge case, and the light receiving section is placed outside the cartridge case. It is also possible to place the light source on the outside of the screen.

As described in the embodiment, if the inner wall for regulating the reel position, which is provided to surround the outer peripheral surface of the reel, also serves as a light blocking wall, there is no need to provide a special light blocking wall, and the structure becomes simpler. This is advantageous in terms of space and allows the magnetic tape cartridge to be made smaller.

Further, as explained in the embodiment, the cartridge case inner opening of the insertion hole into which the light source or the light receiving section is inserted is surrounded by a light-shielding peripheral wall, leaving a part of the side facing the light-transmitting part, and the light-shielding peripheral wall and the light-shielding wall are connected to each other. If the shielding wall is integrally connected with the auxiliary rib, the mechanical strength of the light shielding peripheral wall and the light shielding wall will increase, and the flow of the synthetic resin in the mold during molding will be good, and it will also be easier to remove it from the mold during molding. , deformation of the light-shielding peripheral wall and the light-shielding wall can be prevented, and the light-shielding function can be reliably exhibited.

The present invention has the above-mentioned structure, and the light blocking wall installed inside the cartridge case prevents external light entering through the window from entering the light transmission path formed between the light source and the light receiving section. Therefore, the end of the magnetic tape can be detected optically and accurately, and a highly reliable magnetic tape cartridge is provided.

In the above embodiment, a reel-to-reel type magnetic tape cartridge has been described, but the present invention can also be applied to an endless type magnetic tape cartridge.

[Brief explanation of the drawing]

1 to 40 are diagrams for explaining a magnetic tape cartridge according to an embodiment of the present invention. Figures 1 and 2 are a top view and bottom view of the magnetic tape cartridge, Figure 3 is a front view of the magnetic tape cartridge with the rotating lid removed, and Figure 4 is a view of the magnetic tape cartridge with one reel installed. 5 and 6 are plan views and bottom views of the lower case, FIG. 7 is a sectional view taken along line I-I in FIG. 4, and FIG. 8 is an exploded perspective view of the reel rotation stopper. 9 is a partial sectional view of the reel rotation stopper, FIG. 10 is a perspective view of the left rotation stopper member, FIG. 11 is an exploded front view with a part of the reel in cross section, FIG. Fig. 13 is a plan view and a bottom view of the lower flange of the reel, Fig. 14 is an enlarged sectional view of the main part to explain the fitting state of the tape stopper on the reel, and Fig. 15 shows that the reel is stopped from rotating. FIG. 16 is an enlarged plan view of the rotation stopper in a state where the rotation stopper is released, FIG. 17 is a cross-sectional view along the line ■-■ in FIG. Fig. 18 is an enlarged plan view of the main part showing the installed state of the lock lever, Fig. 19 is a sectional view taken along line IV-IV in Fig. 18, Fig. 20 is a perspective view of the lock lever, and Figs. 21 and 22 are rotational views. A front view and a plan view of the moving lid, Figure 23 is a sectional view along the line ■-■ in Figure 22, Figure 24 is Figure 22 VI
25 is an enlarged sectional view of the main part showing the state where the rotating lid is closed, FIG. 26 is an enlarged sectional view of the main part showing the state where the rotating lid is open, and FIG. A side view of the magnetic tape cartridge for explaining the state in which the moving lid opens and moves, FIG. 28 is a sectional view taken along the line ■-■ in FIG. 4, FIGS. 29 and 30 are a plan view and a bottom view of the upper case, Fig. 31 is a sectional view taken along the line ■-■ in Fig. 30, Fig. 32 and Fig. 3''3 are a plan view and side view of the presser spring, Fig. 34 and Fig. 3
Fig. 5 is a plan view and a side view showing a modified example of the presser spring, Figs. 36 and 37 are a side view and a plan view illustrating the assembled state of the magnetic tape cartridge, and Fig. 38 is a diagram showing the cartridge case and rotation. FIG. 39 is an enlarged side view of the vicinity of the support hole in the upper case, and FIG. 40 is a sectional view taken along the line ■-■ in FIG. 39. 1...Lower case, 2...Upper case, 6
...Reel, 7A, 7B, 79A, 79B...
...Anterior inner wall, 10.74...Side wall, 71.
...Light source tube, 72...Light source insertion recess 73
...... Light source insertion recess, 75... Transparent part,
76... Light receiving section, 77... Shading peripheral wall,
78...Window, 90...Reinforcement rib.

Claims (3)

[Scope of utility model registration request] (1) A cartridge case that stores a magnetic tape with a translucent leader tape connected to the end is provided with a window through which the amount of winding of the magnetic tape can be seen from the outside, and the end is equipped with a light source and a light receiving section. An insertion hole is formed in the cartridge case for inserting either one of the light source and the light receiving part of the detection means, and a transparent part is provided in the peripheral wall of the cartridge case to allow the emitted light from the light source to pass through. A magnetic tape is installed in a cartridge case in advance so that the magnetic tape crosses a light-transmitting path formed between a light source and a light receiving section when the magnetic tape cartridge case is mounted on a recording/reproducing device. . A magnetic tape cartridge, characterized in that a light blocking wall is provided inside the cartridge case to prevent external light entering the cartridge case from entering the light transmission path through the window. (2) Utility model registration Claim (1), wherein the light blocking wall is also used as an inner wall for regulating the reel position provided so as to surround the outer periphery of the reel around which the magnetic tape is wound. A magnetic tape cartridge characterized by: (3) Utility model registration Claim (1), wherein the cartridge case inner opening of the insertion hole is surrounded by a light-shielding peripheral wall except for a part of the side facing the light-transmitting part, and the light-shielding peripheral wall and A magnetic tape cartridge characterized in that the light blocking wall is integrally connected with a reinforcing rib.