JP3536862B2 - Reel base brake mechanism of magnetic recording / reproducing device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reel stand brake mechanism of a magnetic recording / reproducing apparatus suitable for loading a magnetic tape around a rotary head drum of a video tape recorder (VTR).

[0002]

2. Description of the Related Art For example, in a VTR as a magnetic recording / reproducing apparatus using a magnetic tape, a take-up reel table side is locked by a brake lever or the like, and a magnetic tape is pulled out or taken up from a supply reel table side for loading. /
It is common to unload. In this loading method, the magnetic tape is pulled out or wound up on the side of the supply reel table having a large limiter torque. That is, since the limiter torque of the supply reel base must be sent out from the capstan and take up the magnetic tape wrapped around the rotary head drum and many tape guides, the limit of the take-up reel base is taken into account in consideration of the traveling loss. It is larger than the torque.

In order to solve the above-mentioned drawbacks, VTRs in which the supply reel base is locked with a brake lever or the like and the magnetic tape is pulled out or wound on the take-up reel base having a small limiter torque are becoming widespread.

[0004]

However, in a VTR that pulls out or winds up a magnetic tape from the take-up reel base, the tape is not wound on the take-up reel base (tape reel of the tape cassette). In the case of a so-called tape top (including when the number of windings is small), the state of the tape top is detected by an optical sensor or the like, and the loading is temporarily stopped, and the magnetic tape is wound on the winding reel table side (in the tape cassette). The method of winding the tape on a take-up reel) and then reloading the tape takes a long time for the tape top processing, and a complicated and expensive mechanism for the tape top processing is indispensable. .

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a reel base brake mechanism of a magnetic recording / reproducing apparatus which can prevent tape damage and can load / unload a tape easily and in a short time.

[0006]

A pendulum gear for swinging and meshing with one of a supply reel table and a take-up reel table rotatably mounted on a chassis to drive the one reel table is provided. When the tape is loaded around a rotating head drum rotatably mounted on a chassis, the reel is provided with a brake member for braking the supply reel base so that the tape does not flow out of the supply reel base. In the reel table brake mechanism of the magnetic recording / reproducing apparatus which pulls out the tape from the reel table side, when loading the tape, the tape is moved to the winding reel table side.
Detects when the tape is not wound or the number of turns is small.
When the can, the supply reel base by the pendulum gear
The brake state of the supply reel base by the brake member that brakes the supply reel base by rotating the tape in the winding direction is released , and then the pendulum gear is raised.
In order to engage the teeth of the take-up reel base,
It was configured so that the tape could be pulled out from the supply reel table side .

[0007]

When loading the tape of the magnetic recording / reproducing apparatus, the tape is guided by the tape guide from the take-up reel table side in a state where the rack section of the brake member is engaged with the teeth of the supply reel table to brake the supply reel table. When the tape is pulled out and the tape is unloaded, the pendulum gear is meshed with the teeth of the take-up reel base, and the take-up reel base is rotated to take up the tape to the take-up reel base. As described above, since the tape is pulled out or taken up on the take-up reel table side having a small limiter torque, there is no tape damage at the time of loading / unloading the tape.

Further, when the tape is not wound on the take-up reel table side (so-called tape top), the pendulum gear meshes with the teeth of the supply reel table to rotate the supply reel table. Let it. When the supply reel base rotates, the brake member that has meshed with the tooth part of the supply reel base via the rack part slides to separate the rack part of the brake member from the tooth part of the supply reel base and brake the supply reel base. Release the state. This released state is held by the elastic member and the stopper member. Next, the pendulum gear is engaged with the teeth of the take-up reel base, and the tape is pulled out from the supply reel base. Thereby, the tape can be pulled out easily and in a short time.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below in detail with reference to the drawings.

In FIGS. 1, 10 and 11, reference numeral 1 denotes a so-called 8 mm type VTR (magnetic recording / reproducing apparatus) which pulls out and winds up a magnetic tape 10 on a take-up reel base 4 '. . As shown in FIGS.
A movable chassis 2B is arranged on a fixed chassis 2A of the VTR 1 via a plurality of support pins 2C projecting from both sides thereof so as to be capable of reciprocating sliding movement (so-called linear skate) by a drive mechanism (not shown).

A rotary head drum 3 driven by a motor (not shown) is rotatably supported on the fixed chassis 2A. The rotary head drum 3 includes a fixed drum 3a and a rotary drum 3b. A supply reel table 4 and a take-up reel table 4 'are rotatably supported on the movable chassis 2B at a predetermined interval. Reel base bodies 4 of the pair of reel bases 4 and 4 'to be described later.
One of the magnetic tapes 0, 40 'is wound around a magnetic tape 10 in a tape cassette (not shown) by a pendulum gear (swinging gear) 20 which is driven from the capstan motor 5 via a timing belt 9 and swings right and left. It is designed to rotate in the direction in which it is taken. Incidentally, in FIG.
Is a pinch roller for pressing against the capstan motor 5. Reference numerals 12, 13 and 15, 16 denote tape guides for loading the magnetic tape 10, and sliders 14 and 17 which slide on the fixed chassis 2A.
Thus, the rotary head 3 reciprocates around the rotary head drum 3 via a loading mechanism (not shown).

An annular belt 9 is extended between a drive pulley 6 connected to the capstan motor 5 and a driven pulley 8 supported on a fixed chassis 2A via a support shaft 7. Further, as shown in FIGS. 1 and 2, a base of a swing plate 22 made of a metal plate is rotatably supported on a support shaft 21 provided in parallel with the support shaft 7 of the fixed chassis 2A. The pendulum gear 20 made of a synthetic resin is rotatably supported on the lower surface side of the center of the rocking plate 22 via a shaft 23. A disc-shaped felt mat 24 is interposed between the pendulum gear 20 and the swinging plate 22, and a compression coil spring 2 interposed between the pendulum gear 20 and the shaft 23.
5, the pendulum gear 20 is urged toward the felt mat 24 to generate a loss torque. Accordingly, the pendulum gear 20 swings and meshes with one of the reel bases 4 (4 ') depending on the rotation direction of the capstan motor 5. Also, this pendulum gear 2
Reference numeral 0 is meshed with an intermediate gear 27 rotatably supported by a bearing 26 of the support shaft 21, and the intermediate gear 27 is meshed with a tooth portion 8 a formed on a part of the outer peripheral surface of the driven pulley 8. ing.

A brake lever (brake member) for applying a brake to the supply reel table 4 when rewinding (unloading) the magnetic tape 10 is provided on one end side (on the supply reel table 4 side) of the movable chassis 2B. 30 is rotatably supported via a shaft 31 erected on the movable chassis 2B. As shown in FIG. 3, the brake lever 30 is made of synthetic resin such that a long slot 30a is formed in the center, an inverted substantially T-shaped engagement hole 30b is formed in the front end, and a base 30c is formed in a cylindrical shape. And a limiter gear 45 of the supply reel base 4 is provided on the end side surface on the supply reel base 4 side.
The rack portion 30d meshing with the tooth portion 45c is integrally formed. The shaft 31 is loosely fitted in the long groove 30a of the brake lever 30. Thus, the brake lever 30 is rotatably supported in a direction in which the rack portion 30b on the distal end side engages with or separates from the tooth portion 45c of the limiter gear 45 of the supply reel base 4, and the long groove hole portion 3 is provided.
It is slidable vertically in the figure by the length of 0a.

As shown in FIGS. 10 and 11, an upright piece 2D standing on the movable chassis 2B and a brake lever 3 are provided.
0 between the rack 30d of the brake lever 30 and the teeth 45c of the limiter gear 45 of the supply reel base 4 and above the brake lever 30 between the projecting piece 30e integrally formed on the substantially central side surface of the brake lever 30. The tension coil spring (elastic member) 32 for urging the sliding state of the above is interposed.
When a force as shown by an arrow Y in FIG. 11 is applied to the base end portion 30c of the brake lever 30 by an arm member or the like (not shown), the rack portion 30d of the brake lever 30 is supplied against the urging force of the tension coil spring 32. The reel unit 4 is moved away from the teeth 45c of the limiter gear 45 to release the meshing state.

A brake lever 30 is provided between one end of the movable chassis 2B and the tip of the brake lever 30.
Rack part 30d and the limiter gear 45 of the supply reel base 4
A stopper arm (stopper member) 33 for holding a meshing state and a separating state with the tooth portion 45c is rotatably supported. The stopper arm 33 is integrally formed with a shaft 33a rotatably supported on the movable chassis 2B by outsert molding of a synthetic resin and protruding from the upper end of the shaft 33a along the upper surface of the movable chassis 2B. The upper arm portion 33b and the lower arm portion 33b integrally formed so as to protrude from the lower end portion of the shaft portion 33a along the lower surface side of the movable chassis 2B are formed in a flat rectangular shape. A pin 33d integrally formed at the end of the upper arm 33b of the stopper arm 33 is inserted into and engaged with the engaging hole 30b of the brake lever 30. Also, a pin portion 33e integrally formed by projecting downward at the tip of the lower arm portion 33c of the stopper arm 33 is engaged with a cam groove 34a of a cam 34 integrally formed on the upper surface of the fixed chassis 2A by forming a mold outsert. Have been combined. The brake lever 30, the tension coil spring 32, the stopper arm 33 and the cam 34 constitute a reel base brake mechanism 35.

The supply reel base 4 includes a substantially disc-shaped reel base body 40 rotatably supported by a shaft 29 erected on the movable chassis 2B via a cylindrical shaft portion 40a, and a reel base body 40. A reel claw 42 constantly urged upward by a compression coil spring 41 to a shaft portion 40a of the shaft 40, a yoke plate 43 supported by insert molding on the lower surface side of the disk portion 40b of the reel base body 40, Yoke plate 4
3 and a limiter gear 45 rotatably supported below the shaft 29 via a substantially cylindrical shaft portion 45a. The limiter gear 45 is integrated with the limiter gear 45 by outsert molding. And a thrust washer 47 interposed between the plastic magnet 44 and the shaft portion 45a of the limiter gear 45.

As shown in FIG. 4, the reel base body 40 is formed of a synthetic resin, and a disk-shaped yoke plate 43 is supported on the lower surface side of the disk portion 40b by insert molding. A plastic magnet 44 having anisotropy is attached to the lower surface of the yoke plate 43 by suction. A reel claw 42 made of a synthetic resin shown in FIG. 6 is slidably fitted in the upper part of the shaft portion 40a of the reel base body 40 in the axial direction. The limiter gear 45 is formed of a synthetic resin, and is formed by outsert molding.
6 are integrated. Further, a tooth portion 45c is integrally formed on an outer peripheral portion of the limiter gear 45. The thrust washer 47 is formed of a non-magnetic material in the shape of an annular plate, and reduces and stabilizes frictional sliding when the relative rotation between the reel base body 40 and the limiter gear 45 occurs.

The yoke plate 43, the plastic magnet 44, the magnetic plate 46 and the thrust washer 47 constitute a torque limiter mechanism 50. This magnetic plate 46
(Limiter gear 45) and plastic magnet 44
When relative rotation occurs with the (reel base body 40), a steady loss torque is generated during the relative rotation. In order to prevent the wear of the plastic magnet 44, the plastic magnet 44 and the magnetic plate 46
And a predetermined clearance is provided between them. This clearance is achieved by connecting the plastic magnet 44 to the yoke plate 4.
3 and a stepped horizontal portion 4 of the shaft portion 45a of the limiter gear 45
5b is always maintained at a predetermined value by being sandwiched between the shaft 5a and the shaft 5b via a thrust washer 47. Then, the reel base body 40 and the limiter gear 45 rotate together about the shaft 29 by magnetic attraction generated between the plastic magnet 44 and the magnetic plate 46.
Incidentally, the torque limiter mechanism 50 is about 2 mN · m to 3 m.
A limiter torque of N · m (about 20 g · cm to 30 g · cm) is generated.

FIGS. 8 and 9 show a take-up reel table 4 '. The take-up reel base 4 ′ is formed by the point that the tooth part 40 c is formed on the outermost peripheral surface of the disc part 40 b of the reel base body 40 ′ and the magnetic force of the plastic magnet 44
The parts are the same as those of the supply reel base 4 except for the weaker points. Incidentally, the torque limiter mechanism 50 of the take-up reel base 4 'generates a limiter torque of about 1 mN · m (about 10 g · cm). Thus, the limiter torque on the supply reel base 4 side is larger than the limiter torque on the take-up reel base 4 'side.

According to the reel base brake mechanism 35 of the VTR 1 configured as described above, the supply reel base 4 and the take-up reel base 4 ′
Before loading the magnetic tape 10 around the rotary head drum 3 from a tape cassette (not shown) loaded above via a predetermined means, the movable chassis 2B is larger than the fixed chassis 2A as shown in FIG. The movable chassis 2B is located at a position where the movable chassis 2B is lowered before the loading. As a result, the pin 33e of the stopper arm 33 is engaged with the tip end of the cam groove 34a of the cam 34 on the fixed chassis 2A side, and the stopper arm 33 is controlled to the state shown in FIG. Further, the brake lever 30 generates two forces, a rotational force in a direction in which the rack portion 30d meshes with the tooth portion 45c of the limiter gear 45 of the supply reel base 4 and a force sliding upward in the drawing by the tensile force of the tension coil spring 32. In the position shown in FIG. As a result, the supply reel base 4 is locked by the brake lever 30, and the magnetic tape 10 does not come out of the supply reel base 4 when the magnetic tape 10 is loaded.

That is, when the magnetic tape 10 is loaded, the rack portion 30d of the brake lever 30 is engaged with the teeth 45c of the limiter gear 45 of the supply reel base 4 so that the supply reel base 4 is braked. Next, each pair of tape guides 12, 13 and 15, 16 is
By moving the magnetic tape 10 around the rotary head drum 3 by 4 and 17, the magnetic tape 10 is pulled out from the take-up reel table 4 'side (the take-up reel of the tape cassette) and loaded. At this time, since the supply reel table 4 is stopped by the brake lever 30, the magnetic tape 10 does not flow out from the supply reel table 4 side (the supply reel of the tape cassette).

When the movable chassis 2B is completely slid toward the fixed chassis 2A (this position is referred to as a position after loading of the movable chassis), the fixed chassis 2A moves relative to the stopper arm 33 of the movable chassis 2B.
The cam 34 on the side relatively moves downward as shown in FIG. For this reason, the stopper arm 33 is rotated by the cam groove 34a of the cam 34 to be in a state shown in FIG. In this state, the brake lever 30 is driven by the tension force of the tension coil spring 32 so that the rack portion 30d has a rotational force in a direction in which the rack portion 30d meshes with the teeth 45c of the limiter gear 45 of the supply reel base 4, and a sliding force upward in the drawing. , But is not restricted by the pin portion 33d of the stopper arm 33 (because it escapes at the wide portion of the engagement hole portion 30b of the brake lever 30). By pressing the arm 30c with another arm member (not shown) as shown by an arrow Y in FIG. 11, the rack portion 30d of the brake lever 30 is separated from the tooth portion 45c of the limiter gear 45 of the supply reel base 4, and the magnetic tape 10
In the traveling state of, the supply reel base 4 can be made free.

Further, when unloading (rewinding) the magnetic tape 10 into the tape cassette, the capstan motor 3 is rotated counterclockwise (CCW direction) in FIG. The take-up reel base 4 'is rotated by meshing with the teeth 45c of the limiter gear 45 of the reel base 4'. Thus, the magnetic tape 10 is wound on the take-up reel table 4 'side (the take-up reel of the tape cassette) as shown by the dotted arrow in FIG. At this time, the supply reel table 4 is braked by engaging the rack section 30d of the brake lever 30 with the teeth 45c of the limiter gear 45 of the supply reel table 4 so that the supply reel table 4 is braked.
Excessive leakage of the magnetic tape 10 from the side can be prevented.

Before or during the loading of the movable chassis 2B, the magnetic tape 10 is not wound around the take-up reel table 4 '(take-up reel of the tape cassette) (including when the number of turns is small), so-called tape top. , The rack portion 30d of the brake lever 30
Must be separated from the teeth 45c of the limiter gear 45 of the supply reel base 4. In the reel stand brake mechanism 35 of the VTR 1, the movable chassis 2B slides simultaneously with the detection of the tape top by the swingable pendulum gear 20 disposed between the supply reel stand 4 and the take-up reel stand 4 '. The supply reel table 4 is forcibly rotated in the direction indicated by the arrow in FIG. 12B without interruption. Since the rotation of the brake lever 30 is restricted by the pin portion 33 d of the stopper arm 33, when the supply reel base 4 rotates, the brake lever 30 resists the tensile force of the tension coil spring 32 along the rack portion 30 d of the brake lever 30. Then, it slides in the direction of the arrow in FIG. When the brake lever 30 slides to some extent (the position shown in FIG. 12C), the brake lever 30 is no longer restricted by the pin 33d of the stopper arm 33 due to the hole shape of the engagement hole 30b. Thereby, the brake lever 30
As shown in FIG. 12D, the tension coil spring 32 rotates clockwise about the shaft 31 by the tensile force. Further, due to the hole shape of the engagement hole portion 30b of the brake lever 30, the brake lever 30 is held at a position where the rack portion 30d is separated from the tooth portion 45c of the limiter gear 45 of the supply reel base 4.

That is, at any point before or during the loading of the movable chassis 2B, the movable chassis 2B
Since the state of the brake lever 30 that locks the supply reel table 4 can be released without interrupting the slide operation of B, when the tape top is pulled out, the capstan motor 5 is turned in the counterclockwise (CCW) direction in FIG. By rotating, the pendulum gear 20 swings and meshes with the teeth 45c of the limiter gear 45 of the take-up reel base 4 ', and the magnetic tape 10 can be easily and quickly transmitted from the supply reel base 4 side (the supply reel of the tape cassette). Can be pulled out and loaded.

Incidentally, after the movable chassis 2B continues to slide, and after the sliding operation is completely completed,
Since the stopper arm 33 is rotated by the cam 34, the brake lever 30 in which the locked state of the supply reel base 4 is released slides upward in the drawing by the pin portion 33d of the stopper arm 33, and returns to the normal state shown in FIG. You can go back.

As described above, since the supply reel base 4 is locked by the brake lever 30 so that the magnetic tape 10 is pulled out or taken up from the take-up reel base 4 ', no tape damage occurs. In the case of a tape top, the brake of the supply reel base 4 is released and the magnetic tape 10 is pulled out from the supply reel base 4 side, so that a frequent tape top can be instantaneously loaded. Further, since the stopper arm 33 is formed on the movable chassis 2B and the cam 34 is formed on the fixed chassis 2A by mold outsert molding, respectively, and the brake lever 30 and the tension coil spring 32 are only used to change the shape of those used for a normal brake mechanism. It is possible to provide the reel stand brake mechanism 35 with low cost and high reliability.

Although the above embodiment uses a reel base having a torque limiter mechanism using a magnet, it may be applied to a reel base having a torque limiter mechanism using a felt mat. In addition, V of 8mm system
The reel base brake mechanism of TR has been described.
The present invention may be applied to a reel base brake mechanism of various magnetic recording / reproducing apparatuses such as an S type VTR.

[0029]

As described above, according to the present invention, one of the supply reel table and the take-up reel table, which is rotatably mounted on the chassis, swings and engages with the other to drive the one reel table. while having a pendulum gear to the tape from the supply reel mount upon loading the tape around the rotary head drum mounted rotatably on the chassis
In reel base braking mechanism of a magnetic recording and reproducing apparatus but you draw tape from the take-up reel table side a brake member for braking the supply reel mount so as not to flow out, the when loading the tape
The tape is not wound on the take-up reel base or
When a small state is detected, the supply reel table is released from the braking state of the supply reel table by the brake member that brakes the supply reel table by rotating the supply reel table in a direction of winding the tape by the pendulum gear , and then,
Mesh the pendulum gear with the teeth of the take-up reel base
Pull out the tape from the supply reel base side
The tape can be pulled out or wound up on the take-up reel table side with a small limiter torque, so that tape damage is surely prevented when loading or unloading the tape. be able to. Also, when the tape is not wound on the take-up reel table side, the supply reel table is rotated by the pendulum gear to easily release the braking state of the supply reel table by the brake member, and the tape is wound from the supply reel side. Since the tape can be pulled out, even when the tape is not wound on the take-up reel table side, the tape can be pulled out and loaded more easily and in a shorter time than the supply reel table side.

[Brief description of the drawings]

FIG. 1 is an overall schematic plan view showing a VTR according to an embodiment of the present invention.

FIG. 2 is a sectional view of a pendulum gear used in the VTR.

3A is a plan view of a brake lever used in the VTR, and FIG. 3B is a cross-sectional view taken along a line BB in FIG.

FIG. 4 is a sectional view of a supply reel base used in the VTR.

FIG. 5 is a plan view of a reel base used in the supply reel base.

FIG. 6 is a plan view of a reel claw used for the supply reel base.

FIG. 7 is a sectional view of a limiter gear used in the supply reel base.

FIG. 8 is a sectional view of a take-up reel table used in the VTR.

FIG. 9 is a plan view of a reel base used in the take-up reel base.

FIG. 10 is a schematic plan view showing a state before loading of a movable chassis of the VTR.

FIG. 11 is a schematic plan view showing a state after loading of a movable chassis of the VTR.

12 (a) to 12 (d) are explanatory diagrams sequentially showing a release state of the brake member.

[Explanation of symbols]

1. VTR (magnetic recording / reproducing device) 2A ... fixed chassis 2B ... movable chassis 3. Rotating head drum 4: Supply reel base 4 '... take-up reel stand 10 ... Magnetic tape 20 ... pendulum gear 30 ... Brake lever (brake member) 30d ... rack part 32 ... Tension coil spring (elastic member) 33 ... Stopper arm (stopper member) 35 ... Brake mechanism for reel base 45c: Tooth 50: Torque limiter mechanism

Continuation of the front page (72) Inventor Hideto Jimbo 6-7-35 Kita-Shinagawa, Shinagawa-ku, Tokyo Inside Sony Corporation (56) References JP-A-2-172051 (JP, A) JP-A-63- 117360 (JP, A) JP-A-2-166650 (JP, A) JP-A-2-14450 (JP, A) JP-A-3-37433 (JP, A) JP-A-4-319555 (JP, A) JP-U 3-98726 (JP, U) JP-A 62-98029 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G11B 15/22 G11B 15/665

Claims (5)

(57) [Claims] 1. A pendulum gear that swings and meshes with one of a supply reel table and a take-up reel table rotatably mounted on a chassis to drive the one reel table, and is rotatable on the chassis. Supply when loading the tape around the rotating head drum attached to the
In the reel base brake mechanism of the magnetic recording / reproducing apparatus, provided with a brake member for braking the supply reel base so that the tape does not flow out of the reel base, the tape is loaded from the take-up reel base. When the above take-up reel stand
Check that no tape is wound on the side
When the supply reel table is released, the brake state of the supply reel table by the brake member that brakes the supply reel table by rotating the supply reel table in the direction of winding the tape by the pendulum gear is released , and then the pendulum gear
To engage with the teeth of the take-up reel base,
A reel base brake mechanism for a magnetic recording / reproducing apparatus, wherein a tape can be pulled out from the supply reel base . 2. The brake member is rotatably and slidably supported with respect to a chassis, and the brake member is provided with a rack portion which meshes with and separates from the teeth of the supply reel base. 2. A reel base brake mechanism for a magnetic recording / reproducing apparatus according to claim 1, wherein stopper members for holding a meshed state and a separated state of the rack part and the tooth part of the supply reel base are rotatably supported. 3. An elastic member for urging a meshing state between a rack portion of the brake member and a tooth portion of the supply reel base and a sliding state of the brake member are interposed between the chassis and the brake member. 3. A reel stand brake mechanism for a magnetic recording / reproducing apparatus according to claim 2. 4. The chassis comprises a fixed chassis and a movable chassis reciprocating with respect to the fixed chassis. The rotating head drum is disposed on the fixed chassis, and each of the reels is mounted on the movable chassis. 3. A reel base brake mechanism for a magnetic recording / reproducing apparatus according to claim 2, wherein a base, a brake member, and a stopper member are provided. 5. A reel base for a magnetic recording / reproducing apparatus according to claim 1, wherein a supply reel base including a torque limiter mechanism for generating a limiter torque larger than the limiter torque on the take-up reel base side is used. Brake mechanism.