JPH04205948A - Tape recorder device - Google Patents

Abstract

PURPOSE:To diminish disturbance of servo gain owing to eccentricity of a supply reel in simple constitution by providing a tension servo mechanism with plural brake pads to come into contact with a circumferential surface of the supply reel in different positions and giving braking force against rotation of the supply reel through these brake pads. CONSTITUTION:The subject device possesses plural brake pads 56a and 56b to be in contact with the circumferential surface of the supply reel 50 in different positions respectively, and is equipped with the tension servo mechanism for mechanically detecting the tension of a tape 2 on a tape traveling course and giving braking force corresponding to the above tension to the supply reel 50 through the individual brake pads 56a and 56b. That is, a brake arm 56 is provided with two brake pad parts 56a and 56b to be in contact with the circumferential surface of the tape supply reel 50 in different positions respectively. By this method, the servo gain can be promoted, and moreover the tension servo mechanism with high performance having little turbulence of the servo gain against eccentricity of the supply reel 50 can be obtained.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a compact cassette tape recorder, a VT
The present invention relates to tape recorder devices such as R (video tape recorder) and DAT (digital audio tape recorder).

(Prior Art) In recent years, tape recorder devices that record and play back signals using audio/visual video cassettes have become popular, and recently tape recorders that can record and play back digital signals using DAT cassettes have become popular. The device has also been commercialized.

In this tape recorder device, the tape in the DAT cassette is pulled out from the DAT cassette by a loading mechanism, wound around a rotating head drum at a predetermined angle, and then signals are recorded or reproduced.

By the way, in order to keep the tension of the tape constant during signal recording and playback, such tape recorder devices mechanically detect the tension of the tape on the tape running path and adjust the tape supply reel according to the tension. It is equipped with a mechanical tension servo AM that applies braking.

Traditionally, this tension servo mechanism
As shown in FIG.
As shown in FIG. 1, two types of one-pad braking methods are known, in which a brake pad 112 is brought into contact with the peripheral surface of a tape supply reel 111.

(Problem to be Solved by the Invention) However, the band brake method is susceptible to spatial constraints, is expensive, and has the disadvantage that the braking force varies greatly depending on the eccentricity of the tape supply reel. . In addition, with the one-butt brake system, it is difficult to ensure a sufficient servo gain, and since the load is concentrated on one point, the brake pad surface tends to change over time due to wear. Furthermore, like the band brake system, this one-pad brake system was susceptible to the eccentricity of the tape supply reel.

The present invention was made to solve such problems,
The purpose of the present invention is to provide a high-performance tape recorder device which has a simple configuration, has a high servo gain, and has little disturbance in the servo gain due to eccentricity of a supply reel.

[Structure of the Invention (Means for Solving the Problems)] In order to achieve the above object, the tape recorder device of the present invention includes a rotating head for recording and reproducing signals on and from a tape housed in a tape cassette; a loading mechanism that pulls out the tape from the tape cassette to a position where it contacts the rotating head to form a tape running path;
A supply reel for supplying the tape stored in the tape cassette to the tape running path, a reel motor that rotationally drives the supply reel, and a plurality of brakes that contact the circumferential surface of the supply reel at different positions, respectively. The apparatus includes a tension servo mechanism that mechanically detects the tension of the tape on the tape running path and applies a braking force corresponding to the tension to the supply reel through each of the brake pads.

(Function) In the tape recorder device of the present invention, the tension servo mechanism is provided with a plurality of brake pads that contact the circumferential surface of the supply reel at different positions, and a braking force is applied to the rotation of the supply reel through these brake pads. I made it.

This makes it possible to increase the servo gain and realize a high-performance tension servo mechanism in which there is little disturbance in the servo gain due to eccentricity of the supply reel.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 are plan views for explaining the configuration of a tape recorder device according to an embodiment of the present invention, respectively.

In these figures, 1 indicates the main chassis. On this main shaft 1, there is a cylinder drum 3 equipped with a rotating head drum for recording and reproducing digital signals on a tape 2 stored in a DAT cassette (not shown), a capstan shaft 4, and a cylinder drum 3. a loading mechanism equipped with a guide roller 5 of 1 and a group of various rollers that pull out the tape 2 from the DAT cassette to a position where it contacts the peripheral surface of the cylinder drum 3 at a predetermined angle and length, and then maintain the running path of the tape 2; are supported respectively.

This loading mechanism can be broadly divided into first and second loading mechanisms.
It consists of a movable mechanical section and a control mechanism section that controls each of these movable mechanical sections.

The first movable mechanical part has a pinch roller 6 attached to the capstan shaft 4 at one end, and a pinch roller support lever 8 rotatable around a shaft 7 fixed to the main chassis 1.
, a pinch roller pressurizing lever 10 which is rotatable around the shaft 7 and applies pressurization in the direction of arrow A1 to the pinch roller support lever 8 by the force of a coil spring 9; and a second guide roller 11 at one end. Prepared main chassis 1
The pinch roller support lever 8 is centered around the shaft 12 fixed to the
and a guide roller support lever 13 that rotates as the roller rotates.

In this first movable mechanical section, a guide shaft 10a is fixed to one end of the pinch roller pressurizing lever 10, and this guide shaft 10a slides in directions of arrows Bl and B2 on a mechanical chassis (not shown). It engages with a cam groove 22a of a movably supported control slider 22.

Thereby, the pinch roller pressurizing lever 10 is rotated about the shaft 7 by the movement of the control slider 22.

The second movable mechanical part includes loading arms 32A and 3 that support at one end a pair of loading gears 31A and 31B that mesh with each other on the back side of the main chassis 1, respectively.
2B, and a guide groove IA provided in the main chassis 1,
The guide rollers 33A, 33B and the inclined pin 34A are movable along the IB.
Slide bases 35A and 35B equipped with , 34B
and loading links 36A, 36B that connect loading arms 32A, 32B and slide bases 35A, 35B, respectively.

In addition, in this second movable part, loading arms 32A, 32B and loading links 36A, 36B1
The slide bases 35A, 35B and the loading links 36A5, 36B are rotatably connected via rotating shafts, respectively.

Further, as shown in FIG. 2, one of the pair of loading gears 31A and 31B (31B) has a loading lever 42 rotatably supported on a mechanical chassis (not shown) about a shaft 41. The gears are in mesh. The loading lever 42 and the control slider 22 are rotated and slid by a mode switching cam 44 rotatably supported on a mechanical chassis (not shown) about a shaft 43.

That is, this mode switching cam 44 is provided with cam grooves 44a and 44b corresponding to the loading lever 42 and the control slider 22, respectively.
Guide shafts 42a and 22b of the loading lever 42 and the control slider 22 are respectively engaged with the guide shafts 4a and 44b. The mode switching cam 44 is also provided with a cam groove (not shown) for controlling switching of a tension servo mechanism, which will be described later.

As a result, the first movable part operates through the sliding movement of the control slider 22, and moves to a position where the pinch roller 6 on the pinch roller support lever 8 is pressed against the capstan shaft 4. At the same time, the second movable part operates through the rotation of the loading lever 42, and the slide bases 35A and 35B slide toward the cylinder drum 3 along the guide grooves IA and IB provided in the main chassis 1. do. As a result, the tape 2 is wound around the circumferential surface of the cylinder drum 3 at a predetermined angle and length, making it possible to record and reproduce signals.

Note that the mode switching cam 44 is rotationally driven by a motor (not shown) through a driving force transmission means (not shown) such as a connecting gear or a worm gear.

Furthermore, although not shown, a reel motor base on which two reel motors are mounted is fixed between the main chassis 1 and a mechanical chassis (not shown). A tape supply reel 50 and a tape take-up reel 51 are attached to each reel motor via a reel rotation support shaft, and the tips of these tape supply reels 50 and tape take-up reels 51 are connected to the main chassis 1, respectively. protrudes from the surface of

Further, 52 indicates a tension detection arm for detecting the tension of the tape 2 on the tape running path.

This tension detection arm 52 is rotatably supported by a rotating shaft 53 supported by the main chassis 1.

A tension ball 54 that is in pressure contact with the surface of the tape 2 is rotatably supported at one end of the tension detection arm 52. On the other hand, the other end of a tension spring 55 whose one end is fixed is locked to the other end of the tension detection arm 52, so that the tension detection arm 52 is always biased with a constant force in the rotational direction of arrow C1. has been done.

Furthermore, a brake arm 56 for applying a braking force to the rotation of the tape supply reel 50 is rotatably supported on the tension detection arm 52 through a rotation shaft 57. This brake arm 56 is attached to the tape supply reel 50
It has two brake pad portions 561% 56b that abut the circumferential surface of the brake pad at different positions.

Next, the operation of this tape recorder device will be explained.

FIG. 3 shows a state in which a DAT cassette is installed in this tape recorder device.

As shown in the figure, at this time, each slide base 35A
, 35B, the inclined pins 34A, 34B, the pinch roller 6, and the second guide roller 11 are housed in a loading mechanism insertion opening (not shown) in the DAT socket 60.

After this, in FIG. 2, when the mode switching cam 44 is rotated in the direction of arrow D1 by the drive of a motor (not shown),
When the loading lever 42 rotates in the direction of the arrow E1 and each loading gear 31A, 31B rotates from their respective meshes, the rotational force is applied to each loading arm 3.
2A, 32B and each loading link 36A, 36
is transmitted to the slide bases 35A and 35B through B,
As a result, the slide bases 35A and 35B move toward the cylinder head 3 along the guide grooves IA and IB provided in the main chassis 1, as shown in FIGS. 4 to 6.

Also, in parallel with this operation, the arrow D of the mote switching cam 44
By rotating in one direction, the control slider 22 moves in the direction of arrow B1, and as a result, the pinch roller support lever 8 rotates in the direction of arrow A1, and the pinch roller 6 pinches the tape 2 and comes into pressure contact with the capstan shaft 4. .

As a result, the tape 2 is wound around the circumferential surface of the cylinder head 3 at a predetermined angle and length, and the running path of the tape 2 runs from the tape supply reel 50 side to the first guide roller 5 and the guide on the slide base 35B. Roller 33B
The slope is formed by the id pin 34B1, the sloped guide pin 33A on the slide base 35A, the guide roller 34A1, the capstan shaft 4, the pinch roller 6, and the second guide roller 11.

Further, when the mode switching cam 44 rotates in the direction of the arrow Dl, the tension detection arm 52 rotates in the direction of the arrow C1,
As a result, the tension pole 54 on the tension detection arm 52 is brought into pressure contact with the surface of the tape 2, and the chin-jo servo function is activated.

Thereafter, the tape supply reel 50, tape take-up reel 51, and capstan shaft 4 are each rotated to start tape running, and signals are recorded and reproduced on the tape 2.

During this time, the tension of the tape 2 is detected by the tension detection arm 52, and a braking force corresponding to the detected tension is applied to the tape supply reel 50 through the brake arm 56.
Servo control of the tape tension is performed by applying this to .

Next, details of the tension servo mechanism, which is a characteristic part of the tape recorder device of this embodiment, will be explained.

FIG. 7 is a diagram for explaining the principle of the tension servo mechanism using a conventional one-pad brake type tension servo mechanism as an example.

In the figure, fl is the force applied as tape tension to one end of the tension sensor 113, f2 is the repulsive force applied to the brake arm 112 or the tape supply reel 111, and f3 is the force of the tension spring 114. It is.

Here, the clockwise moment about the rotating shaft 115 generated in the tension detection arm 113 by the force f3 of the tension spring 114 and the other forces (fl, f2
) is always in balance with the counterclockwise moment generated in the tension detection arm 113. Therefore, when the tape tension f1 increases, the pressure applied to the brake arm 113 or the tape supply reel 111 decreases, and as a result, the pressure applied to the brake arm 113 or the tape supply reel 111 decreases.
The load rotating torque decreases, and the tape tension f1 also decreases. Conversely, when the tape tension f1 decreases, the pressure applied to the brake arm 112 or the tape supply reel 111 increases accordingly, and as a result, the tape supply reel 11
1 increases, and the tape tension f1 also increases.

In this way, the tape tension f1 is kept constant.

By the way, the important point in the tension servo function is:
The servo gain characteristic is such that the detected tape tension can be converted into sufficient braking force to the tape supply reel, and the servo gain does not vary much with respect to eccentricity of the tape supply reel.

Therefore, in the tape recorder device of this embodiment, the brake arm 56 has two brake pad portions 56a and 5 that abut the circumferential surface of the tape supply reel 50 at different positions.
6b was installed. As a result, it was possible to realize a tension servo mechanism that substantially satisfies each of the above conditions. The details will be explained below.

First, consider the servo gain in the tension servo mechanism of this embodiment.

In the case of the one-pad brake type tension servo mechanism shown in FIG. 7, the pressure applied to the tape supply reel 111 is exactly f2. On the other hand, in this embodiment, the pressure applied to the tape supply reel 50 by each brake pad section 56a, 56b is set to fr, brake arm 5,
If the inclination angle of each arm with respect to the line connecting the support shaft 57 of No. 6 and the center of the tape supply reel 50 is θ, then f2-2Xfr-sinθ, and for example, if Eva is 45
'', the pressure applied to the tape supply reel 50 (
2Xfr) is approximately 1.4X f3.

In other words, the servo gain is about 1.4 times that of the conventional one-pad brake type tension servo mechanism. Note that this servo gain is increased by further reducing θ.

Figure 9 also shows that when the tape supply reel is eccentric,
This figure shows the results of an experiment to confirm how the position of the tension pole of each tension servo mechanism of the present method, the one-pad brake method, and the band brake method changes within one rotation of the tape supply reel. Note that the lever ratio of the tension detection arm (the ratio of the rotation radius of the brake arm to the rotation radius of the tension pole) is 10 in both cases.

As can be seen from the figure, the displacement of the tension pole is approximately 1 in the one-pocket brake system compared to the band brake system.
/2, and it was confirmed that this method requires an even smaller amount of displacement (approximately 15% reduction) than the one-pad brake method. Therefore, it has been confirmed that fluctuations in servo gain caused by eccentricity of the tape supply reel are also reduced.

Furthermore, since the tension servo mechanism of this embodiment is of a type that contacts the tape supply reel 50 at two points, one
Compared to the pad brake system, the brake pad part 56a,
56b also has the advantage of being less likely to wear out.

In the above embodiment, a tape recorder device using a DAT cassette was described, but the present invention can also be applied to a tape recorder device using a videotape.

[Effects of the Invention] As explained above, according to the tape recorder device of the present invention, a high-performance tension servo mechanism with a simple configuration, high servo gain, and little disturbance of the servo gain due to eccentricity of the supply reel is provided. It can be realized.

[Brief explanation of the drawing]

1 and 2 are plan views for explaining the configuration of a tape recorder device according to an embodiment of the present invention, and FIG. 3 shows a state in which a DAT cassette is installed in the tape recorder device of FIG. 1. 4 to 6 are plan views showing the flow of operation of the loading mechanism in the tape recorder device shown in FIG. 1, and FIG. FIG. 8 is a plan view for explaining the servo mechanism as an example; FIG. 8 is a plan view for explaining the servo gain of the tension servo mechanism in the tape recorder device of FIG. 1;
The figures are diagrams for explaining the effects of the tape recorder device shown in Fig. 1, Fig. 10 is a plan view showing a tension servo mechanism using a conventional band brake system, and Fig. 11 is a plan view showing a tension servo mechanism using a conventional one-pad brake system. FIG. 3 is a plan view showing the mechanism. 2...Tape, 3...Cylinder drum, 6...Pinch roller, 8...Pinch roller support lever, 10.
...Pinch roller pressure lever, 11...Second guide roller, 13...Guide roller support lever, 22...
・Control slider, 31A, 31B...Loading gear, 32A, 32B...Loading arm, 33A
133B...Guide roller, 34A, 34B...Inclination is flat, 35A, 35B...Slide base,
36A, 36B...Loading link, 42...Loading lever, 44...Mode switching cam, 50...
...Tape supply reel, 52...Tension detection arm, 54...Tension pole, 55...Tension spring, 56...Brake arm, 56a, 56b...
・Brake band part. Applicant Toshiba Corporation Representative Patent Attorney Suyama Sa − To' Figure 7, No. 8 D

Claims (1)

[Scope of Claims] A rotating head that records and reproduces signals on a tape stored in a tape cassette, and a loading mechanism that pulls out the tape from the tape cassette to a position where it contacts the rotating head to form a tape running path. a supply reel for supplying the tape stored in the tape cassette to the tape running path; a reel motor that rotationally drives the supply reel; and a plurality of reel motors that contact the circumferential surface of the supply reel at different positions. brake pads, and a tension servo mechanism that mechanically detects the tension of the tape on the tape running path and applies a braking force corresponding to the tension to the supply reel through each of the brake pads. Characteristic tape recorder device.