JPH1011939A - Tape cassette - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a tape cassette which reduces consumed power for driving of a tape and has good recording/reproducing characteristics, by forming a pressure pad which follows a magnetic head well and shows a small slide resistance to the magnetic tape. SOLUTION: Zigzag parts 42b1 , 42c1 are formed to be point symetric at leaf spring parts 42b, 42c extending to both lateral directions from a pad felt- fitting face part 42a of a leaf spring 42 supporting a pad felt 41 of a pressure pad member 36, thereby to constitute narrow parts 42b2 , 42c2 of a required angle to a longitudinal main axis 1 of the leaf spring parts 42b, 42c. Because of this, a spring constant of the leaf spring 42 is decreased and, the pad felt- fitting face part 42a can be rotationally deformed and consequently follows a magnetic head well. The obtained pressure pad member shows a small slide resistance to a magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape cassette in which a magnetic head is inserted and pressed against a magnetic tape housed so as to be able to run to perform recording and reproduction.

[0002]

2. Description of the Related Art Conventionally, as shown in FIGS. 9 and 10, a tape cassette for audio or the like has a cassette main body 2 of a tape cassette 1 formed by combining an upper half 3 and a lower half 4, and has an inside. The magnetic tape T is a pair of reel hubs 5,
A pair of guide rollers 9 and 10 and guide pins 11 and 1 disposed on both sides of the front portion of the cassette body 2 are wound around and housed between a pair of upper and lower slip sheets 7 and 8.
2 and tape pass pins 13, 1 along the front opening.
4 is formed so as to be led out to a tape path section 2a formed by the tape path section 4.

[0003] The cassette body 2 includes
Corresponding to the head insertion opening 2b of the front opening as shown in FIG.
The leaf spring 1 is located inside the tape path 2a.
5, a pressure pad member having a head pad 16 attached thereto and a U-shaped shield plate 17 in a plan view are arranged. The leaf spring 15 to which the head pad 16 is attached is formed in a flat shape as shown in FIGS. 11 and 12 by a copper alloy plate of phosphor bronze or the like having a thickness of about 0.08 mm, and shield plates 17 are provided at both ends 15a and 15b. Abuts against the front edge surfaces of both side portions 17a and 17b of
The inner edges of the front edge surfaces of the a and 17b are supported as support points so that the head pad 16 is brought into sliding contact with the back surface of the magnetic tape T.

[0004] The tape cassette 1 thus configured
Is loaded in the recording / reproducing apparatus, and when the magnetic head is inserted into the head insertion slot 2b and pressed against the magnetic tape T, the leaf spring 15 is bent via the head pad 16,
The reaction force due to the elastic deformation caused by this bending becomes a pressure that presses the magnetic tape T against the head, whereby the magnetic tape T is pressed by the magnetic head and the head pad 16.

[0005] In this conventional tape cassette 1, as shown in FIG. 13, the magnetic head H is moved from a reference line in the X direction to a head pad 16 supported and arranged by a leaf spring 15 inside a head insertion opening 2 b. The leaf spring 15 is inserted at a predetermined distance a, that is, at a position of 3.10 to 3.80 mm in the International Electrotechnical Commission Standard (hereinafter referred to as IEC standard), whereby the leaf spring 15 is bent inward to generate a pressing force. And this pressing force is 0.5-1.
5 g / cm ² (5 to 15 N ⁻³ / mm ² )
It is stipulated by EC standard and leaf spring 15
Is positioned on the back surface of the spring with respect to the head insertion direction, and does not deform when the magnetic head H is not inserted. In FIG. 13, E denotes an erasing head, C denotes a capstan, and P denotes a pinch roller.

As described above, the bending deformation of the leaf spring 15 due to the insertion of the magnetic head H is the bending deformation of the fulcrum beam at both ends, and its dynamic behavior can be approximated.

That is, as shown in FIG. 14, the amount of deflection δ of the leaf spring 15 and the reaction force F generated by the leaf spring
Is approximated by the following equation. Here, 1 is the distance between the fulcrums (see FIG. 11), E is the Young's modulus, and I is the second moment of area. As is apparent from this equation, the amount of deflection δ and the reaction force F are in a proportional relationship, and the material and shape are proportional constants (spring constants). FIG.
In FIG. 13 and FIG. 13, the distance 1 between the support points is 18.8 m.
m, the length d of the leaf spring 13 is set to 20.8 mm, and the thickness t is set to 0.08 mm.

In order to satisfy the head pad pressure force defined by the IEC standard, the pressure force is proportionally increased in the specified magnetic head insertion position range according to the spring constant. When the head protrusion amount is large, a large pad pressure force is generated. When the magnetic tape is driven, a frictional force is generated between the magnetic tape and the magnetic head, and between the magnetic tape and the head pad, and this frictional force affects a motor current required for driving the tape.

On the other hand, since the frictional force is given by the product of the friction coefficient and the normal pressure, the motor current increases as the pressure of the head pad, which is the normal pressure, increases, which affects the motor current.

As described above, since the head pad needs to satisfy the specified pad pressing force in the head insertion dimension range of the IEC standard, conventionally, as described above, the leaf spring, which is a supporting component for supporting the head pad, is unloaded. State (Fig. 1
1) to bend from a state without initial deformation to a prescribed position.

[0011]

As described above, in the tape cassette in which the magnetic head is inserted and brought into pressure contact with the magnetic tape, the magnetic tape is attached to the magnetic head by the head pad so that the magnetic tape and the magnetic head come into close contact with each other. If the pressing force is insufficient, the contact between the magnetic head and the magnetic tape will be insufficient if the pressing force is insufficient, causing problems during recording and reproduction. This increases the motor current of the recording / reproducing device required to drive the magnetic tape, and such an increase in power consumption is caused by the continuous use time of a small tape recorder that operates on a battery. This is undesirably reduced in use.

Also, the setting range of the spring constant of the leaf spring supporting the head pad is restricted, so that a pressing force higher than the originally required lower limit pressure is normally exerted. Is not preferable from the viewpoint of power consumption described above.

Further, when the dimensional accuracy of the cassette body or the tape recorder is poor and the magnetic head and the head pad are inclined and come into contact with each other, the contact state between the magnetic tape and the head becomes non-uniform, and the recording / reproducing characteristics are deteriorated. This nonuniform contact state may cause a shift in the width direction when the tape is running, and may damage the tape.

In view of the foregoing, the present invention has been made in view of the above circumstances, and has reduced the torque of the head pad by the leaf spring supporting the head pad so as to approach the lower limit of the IEC standard. It is intended to provide a tape cassette.

[0015]

According to the present invention, a head pad for pressing a magnetic tape housed in a cassette body against a magnetic head inserted from a front opening is supported by a spring member. A tape cassette provided with a pressure pad member, wherein the spring member comprises a head pad mounting portion, and a plate-like support portion extending in both directions from the mounting portion, and a longitudinal main spindle is provided on both plate-like support portions. It is formed by forming a narrow portion having a minimum cross section in a direction forming a required angle with the line.

As described above, by forming the spring member for supporting the head pad, the spring member generates a necessary reaction force in the vicinity of the predetermined insertion position of the magnetic head with respect to the tape cassette, and the magnetic head exerts a magnetic force on the magnetic head. A tape which brings the tape into uniform contact and reduces the spring constant of the spring member, thereby reducing the sliding resistance generated by the head pad, and generating a substantially constant head pad pressing force at a predetermined insertion position of the magnetic head. A cassette can be realized.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. 1 to 8. The present invention is directed to a tape cassette in which a pressure pad member is improved. By reducing the spring constant of the spring member supporting the magnetic head compared to the conventional leaf spring, the change in the head pad pressure force due to the amount of protrusion of the magnetic head is reduced, and the sliding resistance is reduced. The drive current is kept low and good contact between the magnetic head and the magnetic tape can be obtained.

FIG. 1 shows a first example. Also in this example, a cassette body 22 of a tape cassette 21 is formed by combining an upper half 23 and a lower half 24, and a magnetic tape T is provided inside the pair of magnetic tapes T. A pair of guide rollers 29, 30 and a guide pin 31, which are wound between the reel hubs 25, 26, sandwiched and accommodated by a pair of upper and lower slip sheets 27, 28, and arranged on both front corners of the cassette body 22. , 32 to a tape path 22b formed along the inside of the front opening 2a.

The opening at the center of the front opening 22a is a head insertion opening 22c.
A shield plate 33 having a substantially U-shape in plan view is disposed inward of the head opening 33, and both front edges 33a and 33b are disposed on both inner sides of the head insertion opening 22c to guide the tape path portion 2b. In this example, the positioning engagement pins 38 and 39 of the pressure pad member 36 are disposed outside the space between the tape path pins 34 and 35. .

As shown in FIGS. 2 and 3, the pressure pad member 36 of this embodiment supports a pad felt 41 as a head pad and the pad felt 41, and positions the pad felt 41 between the positioning engagement pins 38 and 39 described above. And a leaf spring 42 as a spring member which is engaged and stretched. The leaf spring 42 is formed by pressing a sheet metal, and has a rectangular pad felt mounting surface 42a, plate springs 42b and 42c extending in both directions from the mounting surface 42a, and leaf springs 42b and 42c. 42c is bent at the end of the rear surface direction,
Engaging portion 42 engaged with positioning engagement pins 38 and 39
d and 42e, and the pad felt 41 is attached to the mounting surface portion 42a by bonding with an adhesive sheet 43.

The leaf spring 42
The serpentines 42b and 42c have a plurality of bent portions.
Shape part 42b₁And 42c₁Is formed, and the meandering shape portion 4 is formed.
2b ₁And 42c₁Means the center of the mounting surface portion 42a as the center point.
The meandering shape portion 42
b₁, 42c₁The intermediate portion between the bent portions of the
a required angle θ with respect to the longitudinal main axis l of
Narrow portion 42b with the smallest cross section in the direction_Two, 42c_TwoTo
Is formed. Leaf spring formed in this way
In the plate 42, the plate width dimension a of the plate spring portions 42b and 42c
And narrow portion 42b_Two, 42c_TwoWidth dimension b is a> b
For example, 0.7a 設定 b is set.

As shown in FIG. 1, the pressure pad member 36 of this embodiment constructed as described above is
The engaging portions 42d and 42e of the leaf spring 42 are disposed between the head insertion opening 22c and the shield plate 33 by engaging the positioning engaging pins 38 and 39, respectively.
1 is opposed to the head insertion port 22c with the magnetic tape T interposed therebetween.

In this manner, the tape cassette 21 provided with the pressure pad member 36 is loaded into the recording / reproducing apparatus, and the magnetic head is inserted into the head insertion port 2 of the cassette body 22.
2c, the pressure pad member 36
The leaf spring 42 is pressed through the magnetic tape T and
Is bent inward, but the leaf spring portion 42
b and 42c are the most flexible parts, that is, the narrow parts 42.
Since b ₂ and 42c ₂ have a required angle with respect to the longitudinal main axis l, the pad felt mounting surface portion 42a is liable to be rotationally deformed with respect to the longitudinal main axis.
Meandering portions 42b ₁ and 42c of leaf spring portions 42b and 42c
_{Since 1} is formed point-symmetrically, the same operation is performed in both front and rear directions.

As a result, when the magnetic head and the pad felt 41 are inclined, for example, when the magnetic head is inserted in an inclined state, imbalance in contact with the pad felt 41 occurs, and the leaf spring 42 is attached to the pad felt mounting surface. 4
A force causing a torsional deformation is generated between the pad felt 41a and the supporting points of the leaf spring portions 42b and 42c.
Satisfactorily follows the magnetic head, and the magnetic tape T can be reliably and stably pressed against the magnetic head.

The leaf spring portion 4 of the leaf spring 42
2b, 42c so substantial length becomes longer by meandering parts 42b _1, 42c ₁ is formed, the leaf spring 42 is a spring constant becomes small. As described above, by reducing the spring constant of the leaf spring 42, a tape cassette in which the sliding resistance of the pad felt 41 with respect to the magnetic tape T is reduced can be realized.

FIGS. 4 and 5 show a second example of the pressure pad member.
Similarly to the pressure pad member 36 of the first example described above, a pad felt 51 as a head pad and a leaf as a spring member which supports the pad felt 51 and is stretched by being positioned and engaged with a positioning engagement pin. The leaf spring 52 includes a pad felt mounting surface portion 52a, plate spring portions 52b and 52c extending in both directions from the mounting surface portion 52a, and a back surface at the ends of the plate spring portions 52b and 52c. Portions 52d and 52 bent in the direction and engaged with the positioning engagement pins
e is formed.

Then, the pressure pad member 5 of this embodiment
0 leaf springs 52 are leaf springs 52b, 52c.
Notch-shaped recesses on the upper and lower edges facing each other
Part 52b₁, 52c₁To form a plurality of
Recesses 52b at upper and lower edges₁, 52c₁The space between the leaf springs 52
b, 52c make a required angle with respect to the longitudinal main axis l.
Narrow portion 52b_Two, 52c_TwoIs formed in the book
Also in the case of the example, the concave portions 5 at the upper and lower edges of the plate spring portions 52b and 52c.
2b₁And 52c₁Is the center of the mounting surface 52a
Is formed symmetrically. Formed in this way
In the leaf spring 52, the leaf spring portions 52b, 52
c width width a and narrow portion 52b_Two, 52c _TwoWidth dimension b
Are set so that a> b.

Also in the pressure pad member 50 of the present embodiment formed as described above, when the pad felt 51 is pressed via the magnetic tape by the magnetic head inserted into the head insertion port while being mounted on the cassette body. The leaf springs 52 are bent inward, but the two leaf spring portions 52b and 52c are most easily bent, that is, the narrow portions 52b ₂ and 52c ₂ are in the longitudinal main axis l.
, The pad felt mounting surface portion 52a is likely to be rotationally deformed with respect to the longitudinal main axis, and this deformation is caused by the concave portions 52 of the plate spring portions 52b and 52c.
Since b ₁ and 52c ₁ are formed point-symmetrically,
The same operation is performed in both front and rear directions.

With this arrangement, when the pad felt 51 and the pad felt 51 are inclined, for example, the magnetic head is inserted in an inclined state and imbalance occurs in the contact between the pad felt 51 and the magnetic head, the leaf spring 52 is turned on. The torsion deformation occurs between the pad felt mounting surface portion 52a and the supporting points of the leaf spring portions 52b and 52c, so that the pad felt mounting surface portion 52a is rotationally deformed and the pad felt 51 follows the magnetic head well. Thus, the magnetic tape can be reliably and stably pressed against the magnetic head.

The leaf spring 5 of the leaf spring 52
2b and 52c are upper and lower concave portions 52b ₁ and 52c ₁ , respectively.
By forming the narrow portions 52b ₂ and 52c ₂ between them, the spring constant is reduced, and a cassette tape having a small sliding resistance of the pad felt 41 with respect to the magnetic tape T can be realized.

FIGS. 6 and 7 show a third example of the pressure pad member.
Is composed of a pad felt 61 and a leaf spring 62 supporting the pad felt 61 in the same manner as the pressure pad members 36 and 50 of the first and second examples described above. Leaf spring portion 62 extended from pad felt mounting surface portion 62a to both sides
b and 62c are the leaf springs 42b, 42c and 52b of the leaf springs 42 and 52 of the first and second examples, respectively.
It is formed to have a dimension longer than 52c. This leaf spring portion 62
b, the 62c by the switching lacking recess 62b _1, 62c ₁ opposed by staggered each other in the upper and lower edge portions similarly to the second example forming a plurality of recesses 62b ₁ of each of the upper and lower edges, 62c
₁ while is formed on the narrow portion 62b _2, 62c ₂ which forms the required angle relative to the longitudinal main axis l of the leaf spring portion 62b, 62c.

Also in the case of this embodiment, the leaf spring portions 62b and 62b
c is formed point-symmetrically with the center of the mounting surface portion 62a as a center point, and the ends of the plate spring portions 62b and 62c are also bent rearward and engaged with the positioning engagement pins. The engaging portions 62d and 62c are formed.

Then, the pressure pad member 6 of this embodiment
Reference numeral 0 denotes a leaf spring portion such that the leaf spring 62 is in the initial state and the pad felt mounting surface portion 62a is at the center of the convex shape.
b and 62c are curved.

In order to incorporate the pressure pad member 60 into the cassette body 22, as shown in FIG. 8, the leaf spring 62 is bent concavely against the convex curving biasing force, and both ends, that is, the leaf spring portions are formed. The engaging portions 62d, 62c at the ends of the 62b, 62c are positioned with the positioning engaging pins 38, 39.
The leaf springs 62 are held in a concave shape by holding the inner ends of the tape abutting against the inner surfaces of the tape pass pins 34 and 35, and the pad felt 61 is inserted into the head. It faces the tape path portion 22b of the opening 22c and is pressed against the inner surface of the magnetic tape T,
The interval c between this state (the state shown by the solid line in FIG. 8) and the convex curved state (the state shown by the two-dot chain line in FIG. 8) which is the shape at the time of formation is the initial deflection amount.

As described above, the pressure pad member 60 of the present embodiment can take a large initial deflection amount of the leaf spring 62, so that the spring constant can be further reduced, and the leaf constant can be reduced similarly to the second embodiment described above. The pad felt mounting surface portion 62a of the spring 62 is likely to be rotationally deformed with respect to the main shaft of the spring, so that the magnetic tape T can always be brought into uniform contact with the magnetic head, and stable and good recording and reproduction can be performed. Further, since the sliding resistance applied to the magnetic tape becomes uniform, it is possible to realize a tape cassette having characteristics such that running damage of the magnetic tape can be reduced, sliding resistance is reduced, and power consumption is reduced.

In the third example, meandering portions may be formed in the leaf spring portions 62b and 62c of the leaf spring 62 to form narrow portions.

Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments. For example, a leaf spring as an elastic supporting member for supporting a head pad of a pressure pad member may be used. The shape, that is, the shape forming the narrow portion may be any shape as long as the narrow portion has a required angle with respect to the main axis in the longitudinal direction. The shape, arrangement position, and the like of the positioning engagement pin as a member for positioning and holding the spring can be changed according to the configuration inside the cassette body.

Further, since the shield plate provided inside the pressure pad member does not need to support the leaf spring, the shield plate may not be formed in a U-shape in plan view, but may be formed simply in a flat plate shape. Can be used.

[0039]

As described above, according to the present invention, in the tape cassette, the spring member for supporting the head pad of the pressure pad member is formed with a narrow portion which forms a required angle with the longitudinal main axis, so that the center portion is formed. The head pad mounting part of the part can be rotationally deformed, the head pad can follow the magnetic head satisfactorily, and the magnetic tape can always contact the magnetic head uniformly In addition, since the sliding resistance applied to the magnetic tape becomes uniform, traveling damage of the magnetic tape can be reduced, and stable recording and reproduction can be performed stably.

Further, the spring constant of the spring member supporting the head pad can be reduced, the sliding resistance of the head pad to the magnetic tape can be reduced, and the power consumption at the time of driving the tape can be reduced. The continuous use time of the small-sized recording / reproducing apparatus which operates by the built-in power supply can be extended.

[Brief description of the drawings]

FIG. 1 is a partially cutaway plan view of an example of a tape cassette according to the present invention.

FIG. 2 is a front view of a first example of a pressure pad member used for the tape cassette according to the present invention.

FIG. 3 is a plan view of the pressure pad member shown in FIG. 2;

FIG. 4 is a front view of a second example of the pressure pad member used for the tape cassette according to the present invention.

FIG. 5 is a plan view of the pressure pad member shown in FIG.

FIG. 6 is a front view of a third example of the pressure pad member used for the tape cassette according to the present invention.

FIG. 7 is a plan view of the pressure pad member shown in FIG.

8 is an enlarged plan view of a main part of the tape cassette shown in FIG. 1 in a state where the pressure pad member shown in FIG. 6 is incorporated.

FIG. 9 is a partially cutaway plan view of a conventional tape cassette.

FIG. 10 is an exploded perspective view of a conventional tape cassette.

FIG. 11 is a plan view of a pressure pad member supporting portion of a conventional tape cassette.

FIG. 12 is a front view of a pressure pad member used for a conventional tape cassette.

FIG. 13 is a partial plan view illustrating a tape driving state of a conventional tape cassette.

FIG. 14 is a diagram illustrating a reaction force of a leaf spring.

[Description of Signs] 21 tape cassette, 22 cassette body, 22b
Tape pass portion, 22c head insertion port, 34, 35 Tape pass pin, 38, 39 Positioning engagement pin, 36, 5
0,60 Pressure pad member, 41,51,61
Pad felt, 42, 52, 62 Leaf spring, 42a, 52a, 62a Pad felt mounting surface, 42b, 42c, 52b, 52c, 62b, 62c
Leaf spring portion, 42b ₂ , 42c ₂ , 52b ₂ , 52
c ₂ , 62b ₂ , 62c ₂ narrow portion, 42d, 42e,
52d, 52e, 62d, 62e engaging portion, 1 longitudinal main axis, T magnetic tape

Claims (4)

[Claims] 1. A tape cassette provided with a pressure pad member supported by a spring member for pressing a magnetic tape housed in a cassette body against a magnetic head inserted from a front opening by a spring member, wherein said spring member Consists of a mounting portion for the head pad, and a plate-like spring portion extending in both directions from the mounting portion. The cross-section of the two plate-like spring portions at a required angle with the longitudinal main axis is the smallest. A tape cassette having a narrow portion formed therein. 2. A meandering portion is formed in each of said plate-like spring portions of said spring member, and a narrow portion having a minimum cross-section in a direction forming a required angle with a longitudinal main axis is formed. The tape cassette according to claim 1, wherein 3. A plurality of recesses are formed at both edges of the two plate-like spring portions of the spring member so as to be staggered from each other, so that a cross section in a direction making a required angle with the longitudinal main axis is minimized. The tape cassette according to claim 1, wherein a portion is formed. 4. The apparatus according to claim 1, wherein the spring member is formed by bending forward to form a convex curve, and the spring member is elastically deformed inward and supported on the head insertion opening side of the cassette body. The tape cassette according to claim 1, wherein