JPH03125359A - Reel turntable controller - Google Patents

Abstract

PURPOSE:To prevent a tape from being wound irregularly or traveling unstably by performing feedback control over a tape-width directional moving device according to the quantity of displacement of the tape if a sensor detects the width directional position shift of the tape when the tape is sent out or taken up. CONSTITUTION:When the tape 56 is wound irregularly around a reel 55, the tape 56 shifts in position on a back tension post 57. In this case, the post 57 is irradiated with specific light centering on the reference travel position of the tape 56 and its reflected light is detected by a photodetecting element 64. The specularly finished white post 57 differs in reflection factor from the black tape 56, so the tape displacement is measured as variation in the quantity of reflected light from the post surface. Namely, when a detected distance is constant, the quantity of reflected light from the post 57 is reduced and the detected quantity decreases as the tape edge moves down from the reference travel position. Then when the post 57 stops while abutting on a stopper 60, the tape 56 is held at a constant distance to the sensor 61. Then a reel turntable 9 is moved so that the width directional displacement of the tape 56 is eliminated.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to an improvement of a reel stand portion of an apparatus for recording and reproducing using a tape-shaped magnetic recording medium. More specifically, the present invention relates to a control device that controls the tape running position by moving a reel stand in the tape width direction.

(Prior Art) Currently, in magnetic recording and reproducing devices using magnetic tape such as video tape recorders (VTRs) and digital audio tape recorders (DATs), the volumetric recording density of video data, audio data, and other data is limited. Improvement is required. Taking a tape cassette type device as an example, technology is progressing in the direction of increasing areal recording density and volumetric recording density in order to record a large amount of information in a cassette whose standard has been determined. For the former, concrete measures such as narrowing the track can be considered, and for the latter, measures such as making the tape thinner can be considered.

However, when the track is narrowed, if the tape moves in the tape width direction, playback output fluctuations occur, causing problems. If there are variations in the dimensions of the tape (including the reel) or if the height of the reel stand varies depending on the device, the tape will not run at the reference position, and recording and playback will not be performed accurately with such unstable running. When tapes are made thinner, conventional tape guiding methods that suppress variations in the width direction of the tape by mechanically contacting the tape edges may damage or deform the tape edges. To solve this problem, instead of restricting the tape edge, it is effective to move the entire tape in the width direction and control it so that it runs at a fixed position, or to wrap the tape around the cassette without disturbance. .

Conventionally, as shown in FIG. 9, a device for preventing uneven winding of a tape has been used, in which vibration is applied to a reel stand 102 in a cassette 101 by an excitation device using a cam mechanism 103, and the tape 105 to be wound is moved onto a reel 104. There is a device in which the winding is deflected to one side (Japanese Patent Application Laid-open No.
2-298817).

(Problems to be Solved by the Invention) However, since this device moves the reel stand 102 up and down by the cam 103, it becomes very large as a reel stand device including the configuration for vertical movement, and it is not suitable for VTRs. It is practically difficult to incorporate it into the reel stand of a DAT or a DAT. Furthermore, since the tape 105 is only moved to one side of the reel 104 by vibrating the reel stand 102, it cannot be said that irregular winding can be reliably prevented, and the vibration is uniformly constant regardless of the actual amount of tape fluctuation. When using a cassette that has already been wound irregularly, it is not possible to run it at a fixed position, that is, the standard running position.For this reason, the running position in the tape width direction may vary due to variations in the tape cassette, tape width, etc. change or
If the reel stand device and the tape running reference position vary from tape deck to tape deck, the above-mentioned position regulation by applying a constant vibration cannot be used satisfactorily.

The present invention provides a reel stand control device that allows the tape to run approximately at a predetermined position even when using a cassette in which the tape is randomly wound, and to wind the tape onto the cassette without randomly winding the tape. With the goal. Another object of the present invention is to provide a reel stand control device with a simple configuration.

(Means for Solving the Problem) In order to achieve the above object, the present invention provides a reel that feeds or winds the tape while moving the reel stand in the width direction of the tape based on the output of a sensor that detects the position of the tape in the width direction. In the table control device, the rotor part of the rotary M motor for rotationally driving the reel table and the reel table are rotated integrally in the rotation direction, but the rotation transmission allows the reel table to freely move in the direction orthogonal to the rotation direction. A reel shaft portion connected by a member and rotating integrally with the reel stand is configured to move integrally with the reel stand in the tape width direction, and a movable portion of the tape width direction moving means is attached to the reel shaft portion, While the reel stand is rotated by the rotary drive motor, the movable section is moved by the sensor output, and the tape is sent out or wound up while correcting the tape position.

Further, in the reel stand control device of the present invention, the reel shaft portion is provided with a load reducing means for reducing the load from the reel side of the cassette.

Further, the reel stand control device of the present invention is provided with a reel original position sensor for detecting the position of the reel stand, and the movable portion of the axial movement means is set to a reference position based on the output of the sensor.

(Function) Therefore, when a positional change in the width direction of the tape is detected during tape feeding or winding, only the movable part of the tape width direction moving means, the reel shaft, and the reel stand move in the axial direction according to the amount of displacement. The tape is moved, giving the required displacement in the width direction to the tape, and running at a fixed position.

(Example) Hereinafter, the configuration of the present invention will be described in detail based on an example shown in the drawings.

FIGS. 1A and 1B show an embodiment of the reel stand control device of the present invention. This reel stand control device includes a sensor 61 that detects the position in the width direction of the tape 56 immediately after being pulled out from the cassette 51. and a reel stand device 65 that feeds out or winds up the tape 56 while giving widthwise movement to the tape 56 based on the output of the sensor 61. In addition, the sensor 61
is installed to face the pack tension post 57, for example, at the tape loading end position of the pack tension post 57 for pulling out the tape 56 from the cassette 51. In addition, the reference numeral 52 in the figure is a cassette holder that positions the cassette 51 on the reference surface when the cassette 51 is set in the tape running device, and the reference numeral 54 is a sensor that detects this.

The reel stand device 65 includes a rotary drive motor 67 for rotating the reel stand 9, a tape width direction moving means 68 for displacing the reel stand 9 in the tape width direction, and a reel original position sensor for detecting the position of the reel stand 9 in the tape width direction. The reel shaft 7, which is the center of rotation of the reel stand 9, and the rotation drive motor 67 are connected by a rotation transmission member 66 which rotates integrally in the rotation direction but can freely move relative to each other in the tape width direction. The reel shaft 7 is connected to the movable parts 35, 36, 19 of the tape width direction moving means 68, and the rotating reel shaft 7 and reel stand 9 are displaced in the tape width direction by the tape width direction moving means 68. ing. still,
In this embodiment, a voice coil motor is used as the tape width direction moving means 68 for moving the reel stand 9 in the tape width direction.

As shown in FIG. 2, the rotary drive motor 67 is composed of a rotor magnet 13 supported by magnet receivers 11 and 12 and a stator coil 38 mounted on a printed circuit board 15. The rotor side consisting of .12 is rotatably supported by a plate 14.17 which is a part of the chassis of the VTR via a bearing 32 about the reel shaft 7. This rotor side magnet 13 is attracted to the plate 17 side and applies a certain preload to the bearing 32.

The reel shaft 7 and the reel stand 9 are fixed with a screw 42 and are provided so as to move integrally. The reel shaft 7 is supported by the yoke 31 of the voice coil motor so as to be linearly movable and rotatable, with the linear slider 34 as a bearing. A reel hub 5 is fitted into the reel stand 9 with a spring 8 interposed therebetween so as to be movable in the reel axial direction, and is prevented from coming off by a cap 6. The cap 6 is fixed to the reel shaft 7 with a screw 42. Therefore, the reel hub 5 is movable in the reel axis direction.

The reel stand 9 is connected to the magnet receiver 12 via a rotation transmission member 66.The zero rotation transmission member 66 is made by connecting two leaf springs 1 and 4 with a collar 2.3 and a screw 41. The first side is fixed to the bottom surface of the reel stand 9, and the leaf spring 4 side is fixed to the magnet receiver 12 side, respectively, so that the rotational force of the motor 67 can be transmitted to the reel stand 9. The shapes of these two leaf springs 1 and 4 are not particularly limited and can be selected as appropriate. The springs 1 and 4 have a rectangular shape, and the leaf springs 1 and 4 are connected to each other on one diagonal, and the leaf spring 4 is fixed to the magnet receiver 12 and the leaf spring 1 is fixed to the reel stand 9 on the other diagonal. has been done. Therefore, the rotational force of the rotary drive motor 67 is the magnetic receiver 12 (rotor)→
It is transmitted from the leaf spring 4 to the connecting means 2, 3, and 41 to the leaf spring 1 to the reel stand 9.

The tape width direction moving means/voice coil motor 68 includes one bobbin to which a drive coil 35 is attached, and a magnet 3.
0. Yoke 31 that supports this - Linear slider 3 that supports reel shaft 7 movably in the axial direction with respect to yoke 31
4. Rotation prevention pin 2 for preventing rotation of the bobbin 19
0, a sliding bearing 21 and a bearing 33 that rotatably supports the reel shaft 7 on the bobbin 19. The magnet 30 of this voice coil motor is radially magnetized, and the bobbin 19 is moved in the axial direction of the reel shaft 7 by energizing the drive coil 35 wound in the circumferential direction. That is, the reel shaft 7 rotatably attached to the bobbin 19 via the bearing 33 is moved in the axial direction.

The movable part of the tape widthwise moving means constituted by the bobbin 19 around which the drive coil 35 is wound is fixed to the yoke 31 in the rotational direction by the rotation prevention pin 20, but is movable in the axial direction. It is set in. Further, in this embodiment, a speed detection coil 36 is attached to the bobbin 19, and its output is used to perform speed servo control to improve accuracy. In addition, numeral 18 is a bush for fixing the bearing 33 to the reel shaft 7, 37 is an O-ring for a damper for absorbing shock when the reel stand 9 moves upward,
16 is a printed circuit board.

A reel original position sensor 69 is provided between the yoke 31 of the voice coil motor and the bobbin 19 to detect the reel original position, that is, the axial reference original position of the bobbin 19 interlocked with the reel stand 9. The reel original position sensor 69 includes a Hall element 26 attached to the yoke 31 and a magnet 27 attached to the bobbin 19 side.

The Hall element 26 is housed in a Hall element holder 29 fixed to the yoke 31, and the magnet 27 is housed in the yoke 28 to the magnet holder 22 fixed to the bobbin 19 with a screw 39.
- this reel original position sensor 69
detects the reference position on the reel stand 9 of the tape 56 sent out from the reel stand 9 or the tape 56 wound on the reel stand 9. The voice coil motor 68 only applies axial displacement to the reel stand 9 via the reel shaft 7, and cannot determine the position of the voice coil motor 68 itself.

Therefore, the reference position is confirmed by the reel original position sensor 69, and the amount and direction of movement are determined by the output of the sensor 61.

Further, the yoke 31 is provided with a counterbalance spring 43 that urges the lower end of the reel shaft 7 upward. In current general household VTRs, the cassette is on the reel stand9.
It is configured to be placed on top of. The cassette 51 has a built-in leaf spring 53 that presses the lever 56. Therefore, the weight of the cassette 51 and the load of the spring 53 are applied to the reel stand 9 and the reel shaft 7. Therefore,
A counterbalance spring 43 is provided to reduce these loads and lighten the burden on the tape width direction moving means.

In this embodiment, the device for detecting the tape position is as follows:
It is composed of a pack tension post 57 that pulls out the tape 56 from the cassette 51, and a reflective sensor 61 that emits light toward the post 57 and receives the reflected light.
The widthwise position of the tape 56 wound around the post 57 is measured based on changes in reflected light.

In this embodiment, the pack tension post is used as the tape drawer post 57, but a special post for drawing out the tape is installed near a point where the tape running position needs to be controlled separately from the conventional tape loading mechanism. In either case, a post is used that is not provided with a flange, etc. that mechanically restricts the edge of the tape, at least in the area where the tape is likely to fluctuate. A rotating post is used in which the contact surface rotates. Here, the pack tension post 57 is fixed to a lever-shaped post support block 59, and is installed on the frame (chassis) 14 of the VTR so as to be pivotable about a support shaft 58. The post support block 59 is provided so as to come into contact with the stopper 60 at the tape loading end position to fix the position and stop. The sensor 61 is attached to a sensor support stand 62,
It is fixed on a frame (chassis) 14. When the sensor 61 pulls out the tape, the sensor 61 moves the tape 56 so that it faces the post 57 whose position is fixed by the stopper 60.
It is installed outside the tape, that is, outside the side from which the tape is pulled out, and detects the widthwise displacement of the tape.

As the sensor 61, as shown in FIG.
It is preferable to use a reflective sensor in which the light-emitting part 63 and the light-receiving element 64 are integrated into one, and the light-emitting part 63 and the light-receiving element 64 are arranged so that the light is incident on the post centering on the tape reference running position and the reflected light can be received. It is located. Light emitting part 6 of this sensor
3 is generally a light emitting diode (LED), but a light bulb, laser, etc. can also be used. In addition, the light receiving element 6
4 is generally a phototransistor, but a photodiode, a solar cell, etc. can also be used.

Furthermore, in a tape running system in which the tape 56 is not pulled out from the cassette 51, a light emitting part and a light receiving element may be embedded in sensor posts facing each other while sandwiching the tape. Either one of the transistor or the light emitting diode may be buried, and the other may be placed opposite to the tape loading position.

According to this control block, an example of which is shown in FIG. 6, the output of the tape position sensor 61 and the reel position sensor 69 are
The output of the voice coil motor 68 is selectively introduced into the driver 73 by operating analog switches 71 and 72 to drive the voice coil motor 68. The sensor signal is input to the driver 73 via an amplifier 74 and a compensation circuit 75. At the start of operation, the voice coil motor 68 is set at a predetermined original position by passing the output from the reel original position sensor 69 by inputting a sensor switching signal.

In the operating state, through the output from the tape position sensor 61,
The voice coil motor 68 is moved up and down based on the output.

The reel stand control device configured as described above operates as follows.

For example, the cassette 51 is loaded with a loading mechanism (not shown).
The cassette is inserted into the cassette receiver 52 and set in a fixed position. At this time, an external force F is applied to the cassette tape 51 so that no gap is generated between the cassette reference surface and the cassette receiver 52. Further, a pack tension post 57 and a tape loading post (not shown) are located at predetermined positions within the cassette 51 in order to pull out the tape 56. When the sensor 54 detects that the cassette is not set in the normal position, the reel original position detection sensor 69 is used to control the coil 35 of the voice coil motor 68 in order to set the reel stand 9 to the reference position before starting the operation. An offset voltage for setting a reference position is applied to move the reel stand 9 to the original position. or mechanically set in place. When the movable part (bobbin 19) of the voice coil motor 68 does not move to the original position, it means that the reel 55 is set at the standard position with respect to the cassette reference plane. When the loading of the cassette is completed through the above operations, the tape loading mechanism is activated to sequentially move the tape loading post and pack tension post 57. Once they reach and are positioned, the tape loading operation is complete.

Thereafter, operations such as recording and reproduction are performed by mode operation, and the tape 56 runs. At this time, for example, the tape 56 may be wound randomly on the reel 55. For this reason, variations in the width direction of the tape 56 may occur on the pack tension post 57, but this can be accurately detected as follows. A predetermined light is irradiated onto the post 57 centered on the reference running position of the tape 56 indicated by 0 in FIG. 3(B), and the reflected light is detected by the light receiving element 64. Since the mirror-finished whitish post 57 and the dark tape 56 have different reflectances, the tape displacement is measured as a change in the amount of reflected light on the post surface. That is, when the detection distance (distance M between the post and the sensor) is constant, when the tape edge moves below (to the positive side) from the reference running position (measurement center) 0 in FIG. Since the amount of reflected light increases, the detection current (relative collector current) increases, and as it moves upward (minus II!l), the amount of reflected light from the post 57 decreases and the detection current also becomes smaller. Here, when the post 57 is stopped in contact with the stopper 60, the post 57 and the tape 56 wound around it are maintained at a constant distance from the sensor 61, so that accurate detection can be performed.

Therefore, this detected current is input to a control circuit as shown in FIG. 6 to control the voice coil motor 68 of the reel stand device 65, and move the reel stand 9 so that the widthwise displacement of the tape 56 becomes 0. . By executing this at the time of rewinding, uneven winding is prevented, and by executing this at the time of playback, the fluctuation of the tape in the tape width direction of the fed tape is suppressed.

FIG. 7 shows the results of a tape stable running experiment using such a reel stand control device. In this experiment, as shown in Figure 7 (A), sensors A and B are placed at the position immediately after being fed out of the cassette and after passing through the tape guide, and the displacement in the width direction of the tape is measured at each point. It was done by As is clear from the graph in Figure 7 (B) showing the results of this experiment, tape deviation was severe at both sensor A and sensor B positions before the control was applied, but when the control was applied, the deviation decreased. kept extremely small,
In particular, the displacement of sensor A near the reel stand 9 was so small that it could be ignored.

Although the above-mentioned embodiment is an example of a preferred embodiment of the present invention, it is not limited thereto, and various modifications can be made without departing from the gist of the present invention.6For example, in FIG. Although a voice coil motor is used as the moving means 68, a DC motor, stepping motor, piezoelectric actuator, etc. can also be used depending on accuracy and performance.

Additionally, cams, gears, etc. can also be used as a driving method for the axial movement means.

FIG. 5 shows another embodiment of the reel stand device 65. This reel stand device 65 has a bearing 44 built into the reel stand 9, and the reel stand 9 is rotatably attached to the reel shaft 7.

In this case, the linear slider 34 shown in FIG.
1 becomes unnecessary.

Further, reference numeral 45 is a bush for fixing the bearing 44.

FIG. 4 shows another embodiment of the rotation transmission member 66.

In FIG. 4(A), a connecting bin 46 that engages with the reel stand 9 only in the rotational direction is vertically installed on the magnet receiver 12 of the rotation drive motor (reel motor) 67, and the connecting bin 46 and the reel stand 9 are vertically installed. are connected via a linear bearing 47, and the reel stand 9 is connected by sliding between the connecting bin 46 and the linear bearing 47.
The rotation is transmitted while allowing the reel shaft 7 to move in the axial direction. In FIG. 4(B), the magnet receiver 12 and the reel stand 9 are connected by a bendable link 48, and the link 48
By bending, rotation is transmitted while allowing axial movement of the reel stand 9 and reel shaft 7.

In addition, FIG. 4(C) shows the magnet receiver 12 and the reel stand 9.
are connected by a bellows 49, and rotation is transmitted while allowing the reel stand 9 and the reel shaft 7 to move in the axial direction by expanding and contracting the bellows 49. In either case, the reel stand 9 is fixed to the reel shaft 7, and the magnet receiver 12 is not in contact with the reel shaft 7 and is fixed in position in the axial direction.

(Effects of the Invention) As is clear from the above description, when a sensor detects a positional change in the tape width direction during tape feeding or winding, the tape moves in the width direction according to the amount of displacement. Since the means is subjected to feedback control, irregular winding of the tape and unstable running of the tape can be prevented.

Further, the reel stand control device of the present invention moves only the reel stand, the reel shaft portion connected thereto, and the movable portion of the tape width direction moving means in the tape width direction based on the output of the tape width direction position detection sensor. As a result, the weight and load of the movable part of the tape width direction moving means are reduced, and the device can be prevented from increasing in size and has a simple structure. Moreover, this weight reduction reduces power consumption, requires smaller circuit components, generates less heat, and improves frequency response.

Further, as is clear from the comparison with the conventional reel motor shown in FIG. 8, there is an advantage that most of the parts can be shared, and it is also possible to make the motor thinner.

Furthermore, if a load reduction means such as a counterbalance is provided, the load on the tape width direction moving means is reduced, so that the operating current can be reduced and the structure can be made more compact.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the reel stand control device of the present invention, in which (A) is a front view and (B) is a plan view. Fig. 2 is a central vertical sectional view showing an embodiment of the reel stand device, and Fig. 3 (
A) is a perspective view showing an example of the sensor, (B) is a graph showing the relationship between the tape position of the phototransistor and the output voltage, and Figures 4 (^) (B) and (C) are other views of the rotation transmission member. A schematic diagram showing an embodiment, FIG. 5 is a central vertical sectional view showing another embodiment of the reel stand device, FIG. 6 is a control block diagram, and FIGS. 7 (A) and (B) are the reel stand of the present invention. A schematic diagram showing an experimental method of the control device and a graph showing the experimental results, FIG. 8 is a central vertical sectional view showing a conventional reel stand device, and FIG. 9 is a principle diagram showing the conventional reel stand control device. 67...Rotation drive motor, 68...Tape width direction moving means, 6...Reel original position sensor.

Claims (1)

[Scope of Claims] (1) A reel stand control device that feeds or winds the tape while moving the reel stand in the width direction of the tape based on the output of a sensor that detects the position of the tape in the width direction. A rotor part of a rotary drive motor for rotational driving and a reel stand are connected by a rotation transmission means that rotates integrally in the rotational direction but allows the reel stand to freely move in the axial direction,
A reel shaft that rotates integrally with the reel stand is configured to move in the tape width direction together with the reel stand, a movable part of a tape width direction moving means is attached to the reel shaft, and the reel stand rotates as described above. A reel stand control device characterized in that the movable part is moved by the sensor output while being rotated by a drive motor, and the tape is sent out or wound up while correcting the tape position. (2) The reel stand control device according to claim 1, wherein the reel shaft portion is provided with a load reducing means for reducing the load from the reel side of the cassette. (3) A reel original position sensor for detecting the position of the reel stand is provided, and the movable part of the tape width direction moving means is set to a reference position based on the output of the sensor. The reel stand control device described.