Magnetic recording and reproduction apparatus

A magnetic recording and reproduction apparatus includes a pivotable arm section; an arm pivoting center shaft for supporting the pivoting center of the arm section; a capstan section for driving a magnetic tape so as to run; a pinch roller provided on the arm section for pressing the magnetic tape to the capstan section; and an extendable and compressable section extendable so as to be wound around the arm pivoting center shaft in accordance with the pivoting of the arm section and compressable so as to retract from the arm pivoting center shaft in accordance with the pivoting of the arm section.

This non-provisional application claims priority under 35 U.S.C., §119(a), on Patent Application No. 2003-078009 filed in Japan on Mar. 20, 2003, the entire contents of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a magnetic recording and reproduction apparatus which has a reduced size with a simple structure.

2. Description of the Related Art

Recently, the reduction of the weight, production cost and power consumption of magnetic recording and reproduction apparatuses has become desirable.

Hereinafter, a conventional magnetic recording and reproduction apparatus will be described.

A conventional magnetic recording and reproduction apparatus as described in Japanese Laid-Open Publication No. 11-273184 is known.

The above-mentioned magnetic recording and reproduction apparatus has the following problem. As shown inFIGS. 13 through 17of Japanese Laid-Open Publication No. 11-273184, the pivoting range of a pinch arm53is large, and a tension spring58extends and compresses, and moves right and left in a large area in accordance with the movement of the pinch arm53. Therefore, the tension spring58occupies quite a large area when in operation, which hinders size reduction of the magnetic recording and reproduction apparatus.

SUMMARY OF THE INVENTION

A magnetic recording and reproduction apparatus according to the present invention includes a pivotable arm section; an arm pivoting center shaft for supporting the pivoting center of the arm section; a capstan section for driving a magnetic tape so as to run; a pinch roller provided on the arm section for pressing the magnetic tape to the capstan section; and an extendable and compressable section extendable so as to be wound around the arm pivoting center shaft in accordance with the pivoting of the arm section and compressable so as to retract from the arm pivoting center shaft in accordance with the pivoting of the arm section.

In one embodiment of the invention, the magnetic recording and reproduction apparatus further includes a pressure-contact section provided on the pivoting center of the arm section, the pressure-contact section being pressure-contactable to the arm section so as to press the magnetic tape to the capstan section. The extendable and compressable section is extendable so as to be wound around the pressure-contact section in accordance with the pivoting of the arm section and is compressable so as to retract from the pressure-contact section in accordance with the pivoting of the arm section.

In one embodiment of the invention, the magnetic recording and reproduction apparatus further includes a chassis section accommodating the arm pivoting center shaft. One end of the extendable and compressable section is connected to the chassis section, and another end of the extendable and compressable section is connected to the arm section.

In one embodiment of the invention, the extendable and compressable section exerts a force on the arm section for pulling the arm section in such a direction so as to separate the pinch roller from the capstan.

In one embodiment of the invention, the extendable and compressable section is a tension coil spring, and the pressure-contact section is a twisted coil spring.

In a magnetic recording and reproduction apparatus according to the present invention, the return spring for the pinch roller arm is extended in an arc along the outer circumference of the contact-pressure spring. Owing to this structure, the return spring can be provided in a very small space.

Thus, the invention described herein makes possible the advantages of providing a magnetic recording and reproduction apparatus having a reduced size.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

A magnetic recording and reproduction apparatus according to the present invention includes a rotatable capstan shaft for transporting a magnetic tape; a pinch roller to be pressed to the capstan shaft to sandwich the magnetic tape with the capstan shaft; a pinch arm section pivotably supporting the pinch roller; a chassis section for pivotably supporting the pinch arm section; a pressure-contact spring section provided so as to be pivotable about the pivoting center shaft of the pinch arm section, thus pressure-contacting the pinch roller to the capstan shaft; and a return spring extended between the pinch arm section and the chassis section for separating the pinch roller away from the capstan shaft. The return spring is extendable in an arc along the outer circumference of the pressure-contact section. Thus, the return spring can be provided in a very small space.

Also according to the present invention, the pressure-contact spring is a twisted coil spring, and the return spring is a tension coil spring. The return spring can be provided in a very small space, and the noise generated by the extension and compression of the return spring can be reduced.

FIGS. 1 and 2show a structure of a shrink mechanism of a magnetic recording and reproduction apparatus according to the present invention.

In the shrink mechanism, a movable chassis referred to as a sub chassis moves with respect to the main chassis. When the magnetic recording and reproduction apparatus is in the state of allowing a magnetic tape cassette to be mounted thereon or taken out therefrom, the sub chassis projects from the main chassis. When the magnetic recording and reproduction apparatus operates after tape loading, the sub chassis retracts so as to be substantially nested in the main chassis.

The main chassis accommodates components such as a tape guide drum, a capstan motor, a pinch roller and the like, and the sub chassis accommodates reel stands, a cassette holder, a tape pull-out post and the like.

InFIGS. 1 and 2, some of the components are omitted for simplicity.

A structure and an operation of the magnetic recording and reproduction apparatus will be described.

Reference numeral60represents a main chassis (chassis section). The main chassis60accommodates a tape guide drum62, a capstan motor64, a pinch roller unit66, and the like which are required for tape running.

Reference numeral68represents a sub chassis. The sub chassis68accommodates two reel stands70aand70b, a cassette holder (not shown) and the like. On the sub chassis68, a magnetic tape cassette (not shown) is mountable.

The sub chassis68is supported by the main chassis60via guide sections72aand72b, and are relatively movable in directions represented by arrows A and B.

A cam gear74is provided on the main chassis60and is pivotable in directions represented by arrows C and D about a cam gear shaft75by a motor (not shown).

A cam pin76is provided on a top surface of the cam gear74and is engageable with a cam portion78provided in the sub chassis68.

Owing to this engagement, the sub chassis68is movable in the direction of arrow A or B in accordance with the pivoting of the cam gear74.

The cam gear74has a contact (not shown) for detecting a pivoting angle thereof, such that the position of the cam pin76can be found.

In the state ofFIG. 2, the sub chassis68has moved to the utmost position in the direction of arrow B.

A kick arm80is provided between the cam gear74and the sub chassis68. The kick arm80is pivotably supported by an arm shaft82provided on the main chassis60. A cam groove84of the kick arm80is in engagement with the cam pin76.

The kick arm80moves In association with the movement of the cam pin76, and pivots about the arm shaft82in a direction represented by arrow E or F at the timing which is determined by the shape of the cam groove84.

Reference numeral86represents a stopper pin, which restricts the pivoting of the kick arm80in the direction of arrow F.

A pinch roller unit66includes a pivotable pinch roller arm90(arm section) and a pinch roller98, an axis of which is supported by the pinch roller arm90. The pinch roller unit66has a boss67at the pivoting center thereof.

The pinch roller arm90supports a pressure-contact spring100(pressure-contact section) in a flexible state around an outer circumference of the boss67. The pivoting center of the pinch roller arm90is supported by a pinch roller pivoting shaft88(arm pivoting center shaft). The pressure-contact spring100is, for example, a twisted coil spring.

A tip portion101of the pressure-contact spring100is bent at a right angle and is engageable with a kick portion104of the kick arm80.

A spring hanger65is provided on the pinch roller arm90in the vicinity of the boss67. On the spring hanger65hangs a hook93of a return spring96(extendable and compressable section). The return spring96is, for example, a tension coil spring.

The return spring96is extended so as to be wound around the pinch roller pivoting shaft88in accordance with the pivoting of the pinch roller arm90, and is compressed so as to retract from the pinch roller pivoting shaft88also in accordance with the pivoting of the pinch roller arm90. The return spring96acts on the pinch roller arm90so as to pull the pinch roller arm90in such a direction so as to separate the pinch roller98from a capstan shaft102(capstan section).

A hook91at the other end of the return spring96is in engagement with a spring hanger61(FIG. 2) provided on the main chassis60. This engagement can be achieved in the state where the pinch roller unit66is outserted into the pinch roller pivoting shaft88.

The spring hanger61is provided at such a position that the return spring96is extended in an arc around an outer periphery of the pressure-contact spring100.

In this example, the two ends of the return spring96are hung on the spring hangers93and61. Alternatively, one end of the return spring96may be connected to the pinch roller arm90in any other manner, and the other end of the return spring96may be connected to the main chassis60in any other manner.

The pressure-contact spring100is a pressure-contact section which is pressure-contactable to the pinch roller arm90so as to press the magnetic tape to the capstan section. As described above, the pressure-contact spring100is provided around the pinch roller pivoting shaft88. In this case, the return spring96is extended so as to be wound around the pressure-contact spring100in accordance with the pivoting of the pinch roller arm90, and is compressed so as to retract from the pressure-contact spring100also in accordance with the pivoting of the pinch roller arm90.

A bent portion92of the pinch roller arm90is located so as to face a bent portion94of the sub chassis68.

An operation of the magnetic recording and reproduction apparatus will be described with reference toFIGS. 2 through 6.

When the cam gear74pivots from the state inFIG. 2in the direction of arrow C, the sub chassis68moves in the direction of arrow A by the engagement of the cam pin76and the cam groove84as shown inFIG. 3.

At this point, the bent portion92of the pinch roller arm90is pressed by the bent portion94of the sub chassis68. Thus, the pinch roller unit66pivots in a direction represented by arrow J against the force of the return spring96providing a pivoting torque in a direction represented by arrow H.

The distance between the hook91and the hook93of the return spring96are increased as the pinch roller arm90pivots in the direction of arrow J, and thus the return spring96is extended. The area occupied by the return spring96can be very small although the angle over which the return spring96is wound around the pressure-contact spring100is increased.

When the cam gear74further pivots in the direction of arrow C to the position shown inFIG. 4, the sub chassis68stops moving in the direction of arrow A. After this, the sub chassis68does not move owing to the shape of the cam portion78.

In this state, the pinch roller unit66is at a stop position where the pinch roller98is in a wait state at a position which is a slight distance from the capstan shaft102.

When the cam gear74further pivots in the direction of arrow C, the kick arm80pivots in the direction of arrow E owing to the shape of the cam groove84while the sub chassis68is paused.

As a result, the kick portion104of the kick arm80is engaged with the tip portion101of the pressure-contact spring100, thereby pivoting the pinch roller unit66in the direction of arrow J. Even after the pinch roller98contacts the capstan shaft102, the pinch roller unit66still pivots. This operation causes an end portion of the pressure-contact spring100to flex, generating a pressure-contact force in the pinch roller98. Thus, the magnetic recording and reproduction apparatus is placed into play mode shown inFIG. 5.

In this state, the pinch roller98presses the magnetic tape (not shown) to the capstan shaft102for driving the magnetic tape so as to run. Thus, the magnetic tape sandwiched between the pinch roller98and the capstan shaft102is transported by the rotation of the capstan motor64.

The cam groove84of the kick arm80is a positive motion cam having a width which is substantially equal to the outer diameter of the cam pin76, except for a portion thereof represented by letter G (FIG. 2). The portion G has a wider width for the following reason.

While the cam pin76is outside the portion G (FIGS. 2,4and5), the pressure angle between the cam pin76and the cam groove84does not hinder any movement of the cam pin76in the cam groove84. While the cam pin76is in the portion G, the pressure angle between the cam pin76and the cam groove84is very large. Especially in the state shown inFIG. 3where the cam gear shaft75, the cam pin76and the arm shaft82are arranged in a straight line, the pressure angle is 90 degrees. The width of the portion G is slightly wider than the rest of the cam groove84in order to prevent the cam pin76from being immovably stuck in the cam groove84.

While the cam pin76is in the portion G, the kick arm80is movable in the directions of arrows E and F about the arm shaft82, except that the movement in the direction of arrow P is restricted by the stopper pin86.

The kick arm80needs to be pivotable in the direction of arrow E until the magnetic recording and reproduction apparatus is placed into play mode shown inFIG. 5. However, if the kick arm80was excessively pivoted in the direction of arrow E in the state shown inFIG. 3, the pressure angle between the cam pin76and the cam groove84would become too large to place the kick arm80into a self-locked state.

In order to restrict the pivoting of the kick arm80in the direction of arrow E, the kick arm80has a pivoting stop portion106(FIG. 1). While the tip portion101of the pressure-contact spring100of the pinch roller unit66moves facing the pivoting stop portion106, the pivoting of the kick arm80in the direction of arrow E is restricted, Therefore, as shown inFIG. 6, the kick arm80can only move between the position represented by the one-dot chain line and the position represented by the solid line. As a result, the pressure angle between the cam pin76and the cam groove84is as presented by letter K inFIG. 6. Thus, the self-lock state of the kick arm80is not generated.

The pivoting stop portion106is provided so as to cover the area of movement of the tip portion101of the pressure-contact spring100while the cam pin76moves in the portion G. The pivoting of the kick arm80is restricted by stopper pin86and the tip portion101of the pinch roller unit66.

As described above, in a magnetic recording and reproduction apparatus according to the present invention, the extendable and compressable section extends so as to be wound around the arm pivoting center shaft in accordance with the pivoting of the arm section, and compresses so as to retract from the arm pivoting center shaft in accordance with the pivoting of the arm section.

Since the extendable and compressable section is extendable in accordance with the pivoting of the arm section with no need to pivot the extendable and compressable section, no extra area is necessary for accommodating the pivoting of the extendable and compressable section. Thus, the size of the magnetic recording and reproduction apparatus can be reduced.

As described above, according to the present invention, even when the return spring96is extended in accordance with the pivoting of the pinch roller arm90, the area occupied by the return spring96is very small; although the angle over which the return spring96is wound around the pressure-contact spring100is enlarged. This significantly reduces the size of the magnetic recording and reproduction apparatus.

In general, an outer circumference of a spring is smooth. The outer circumference of the return spring96is always in contact with the pressure-contact spring100. The return spring96does not cause any large noise when rapidly extended or compressed. This prevents the magnetic recording and reproduction apparatus from generating a disturbing noise.