JPH08180527A - Mechanism for guiding tape - Google Patents

Abstract

PURPOSE: To obtain a tape guide mechanism letting a tape attachment member freely vibrate without restricting the resonance of a guide pipe aimed for an effect to reduce frictions. CONSTITUTION: The mechanism has a shaft 13 having one fixed end 13a and a tape attachment member 14 rigidly secured to a predetermined position of the shaft 13. The tape attachment member 14 is vibrated and shifted by a vibrating means 7 vibrating the shaft 13. A first mass system consisting of the tape attachment member 14, a second mass system 12' set at a free end of the shaft 13 and a third mass system 15 attached to the second mass system 12' are provided. Moreover, the second mass system 12' and third mass system 15 are coupled via an extension member 16' expanding/shrinking in a nearly orthogonal direction to the shaft 13. The extension member 16' is driven by a vibrating/driving means.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tape guide for guiding a tape-shaped recording medium used in a recording or reproducing device (hereinafter, simply referred to as recording / reproducing device).

[0002]

2. Description of the Related Art Of these types of recording / reproducing apparatus, tape guides used in magnetic recording / reproducing apparatuses such as VTRs that use magnetic tapes are roughly classified into two types, so-called fixed guides and rotating guides. The fixed guide has an advantage of being able to guide the tape stably, but avoids a large tape winding angle because the tape tension increases due to the friction caused by the contact with the tape. There is a need. Further, since the friction coefficient between the tape and the tape guide is different when the tape is stationary and when it is running, it is essentially disadvantageous for stabilizing the tape tension. On the other hand, the rotation guide has an advantage that the increase rate of the tape tension is small, but there is a problem that the tape guide becomes unstable due to the rotational runout of the roller and the slip in the tape width direction.

By the way, the recording density of the magnetic recording / reproducing apparatus has been remarkably increased, and accordingly, in the tape-shaped recording medium, smoothing of the surface, thinning of the surface, stabilization of running, and improvement of accuracy have been achieved. Further, as the recording capacity of the tape-shaped recording medium has increased, demands for operability such as searchability have increased, and further speeding up of tape running has been demanded. Therefore, in the magnetic recording / reproducing apparatus, it is necessary to make the tape running stability and the tape tension stability compatible, but as described above, both the fixed guide and the rotating guide essentially meet such requirements. Is difficult.

On the other hand, as a device that can meet such needs, there is a device in which compressed air is ejected from a small hole provided in the surface of the fixed guide, or a device in which the surface of the fixed guide is ultrasonically vibrated. Being developed. According to these tape guides, the tape guides have the characteristics that satisfy the above-mentioned requirements, but of these, the one that uses compressed air is inevitably a very large unit because it requires a compressor and piping. It is not suitable in terms of downsizing of the device. On the other hand, a device utilizing ultrasonic vibration can be made smaller.

Here, FIG. 10 shows a structural example of a conventional tape guide utilizing ultrasonic vibration. In the figure, the guide unit 110 includes a shaft 111 and a screw 116.
Is erected on the base 120 by the upper flange 114, the pipe 112, and the lower flange 11 with respect to the shaft 111.
It has a structure in which 5 is press-fitted and fixed. Magnetic tape 100
The guide pipe 113 that guides (see FIG. 12) the outer peripheral surface of the pipe 112 has two projections 112 a and 112 of the pipe 112.
held by b. The vibrator 101 is composed of a laminated piezoelectric element in this example, and is configured to expand and contract when a voltage is applied. Shaker 1
One end of 01 is adhesively fixed to the surface of the guide pipe 113 and is held by the holding member 103 so as not to come into contact with the magnetic tape 100.

When an AC voltage is applied to the shaker 101, the expansion and contraction thereof causes the guide pipe 113 to vibrate. By vibrating the guide pipe 113 at an appropriate frequency, a resonance state as shown in FIGS. 11 and 12 can be obtained. The resonance mode has two nodes X and Y in the axial direction as shown in FIG. Further, in the radial direction as shown in FIG. 12, an elliptical shape having a long axis in the vertical direction and an elliptical shape having a long axis in the horizontal direction are repeated in the figure, but the phase of the vibration exciter 101 ( A) and phase (ke) are in phase, and phase (e) and phase (s)
Has become an anti-phase belly. Further, in this resonance mode, the outer peripheral surface of the guide pipe 113 is in a state shown in FIG. 13 when viewed in a surface development view.

In the above case, the two axial nodes X and Y (FIG. 11) are the two projections 112a and 112 of the pipe 112.
It is made to correspond to the position corresponding to b, so that the vibration restraining action due to holding the guide pipe 113 can be eliminated, and the efficiency in this resonance mode can be improved. When the magnetic tape 100 is attached to the vibrating guide pipe 113 in this manner, the time in which the magnetic tape 100 and the magnetic tape 100 are in contact with each other is substantially reduced, and the friction can be remarkably reduced especially at rest.

[0008]

However, in the above-mentioned conventional guide unit 110, the magnetic tape 100 is used.
Since the guide pipe 113 that generates a standing wave is formed at the splicing portion of the above and the shaft 111 that supports the guide pipe 113 at the node position of the resonance mode, the following problems occur.

That is, (1) a mechanism for supporting the guide pipe 113 at the node of the resonance mode is required so as not to restrain the displacement of the resonating guide pipe 113. Guide pipe 113
In order to set the positions of the nodes X and Y in
High processing and assembly accuracy are required, and the guide pipe 113
In itself, high processing accuracy is required to obtain a predetermined shape dimension and surface roughness, which makes mass production processing difficult.

(2) The resonance state of the guide pipe 113 is
It is determined by the length, diameter, thickness and material of the guide pipe 113. To reduce the size of the tape guide,
There is a method of reducing the length, diameter, etc. of the guide pipe 113. However, when this is done, the resonance frequency rises, which promotes internal damping. Further miniaturization requires high processing accuracy, which eventually increases the cost and also deteriorates the handleability of parts. Furthermore, the length, diameter, and
Regarding thickness, it is easy to be subject to mechanical restrictions, and it is practically difficult to greatly change the parameter. Also,
For the material of the guide pipe 113, refer to Guide Pipe 1
It does not have such a degree of freedom that the rigidity of 13 can be greatly changed, and therefore, the conventional structure must have a small degree of freedom for setting the resonance frequency. In other words, there is a certain limit to such miniaturization and cost reduction.

(3) The ring-shaped guide pipe 113 having high rigidity is used as the resonance mode for producing the friction reducing effect.
In order to generate a standing wave with a predetermined amplitude by ultrasonic vibration, a large amount of energy is required, and because it is necessary to use a material with small internal damping and good vibration efficiency, such as ceramic, It has to be expensive. (4) A plurality of vibration states can be obtained in which a standing wave is formed in the guide pipe 113 to obtain a friction reducing effect, but in reality, the structure supports a plurality of positions that are nodes of a single resonance mode. , In other resonance modes, the position where the support portion becomes a node does not match, and the guide pipe 1 can be efficiently used depending on the situation.
The 13 resonance modes cannot be used properly. (5) Then, for the above reason, the plurality of resonance states cannot be switched in the tape running state.

An object of the present invention is to realize a tape guide mechanism which has a friction reducing effect by a resonance phenomenon of high efficiency and is suitable for downsizing at low cost.

And, in particular, the present invention does not restrain the resonance phenomenon of the guide pipe for obtaining the friction reducing effect,
It is an object to realize a tape guide mechanism that freely vibrates a tape splicing member. Another object of the present invention is to realize a tape guide mechanism that achieves a stable and effective resonance state without changing the resonance state of the guide pipe for obtaining the friction reducing effect. Further, the present invention provides
An object of the present invention is to realize a tape guide mechanism capable of optimally driving an elastic member.

[0014]

The tape guide mechanism of the present invention has a shaft having one end fixed and a tape attachment member fixed to a predetermined portion of the shaft, and vibrating means for vibrating the shaft. By virtue of the above, the tape splicing member is oscillated and displaced. In particular, a first mass system composed of the tape splicing member and a second mass system provided on the free end side of the shaft are provided.
A third mass system attached to the second mass system is set, and the second mass system and the third mass system are connected via an elastic member that expands and contracts in a direction substantially orthogonal to the axis. A mass system is connected, and the elastic member is driven by a vibration driving means.

Further, in the tape guide mechanism of the present invention, the total sum of the masses of the second mass system and the third mass system is maintained at a constant value, and the mass of the third mass system is adjusted to the second mass system. Is set larger than the mass of the mass system of.

Further, in the tape guide mechanism of the present invention, the elastic member composed of an electro-mechanical conversion element,
A drive circuit for supplying electric power to the electro-mechanical conversion element,
An oscillation circuit that operates near the resonance frequency of the vibrating tape guide including the shaft, a current detection unit of the drive circuit, a voltage detection unit of the drive circuit, and a phase difference between the detected current and voltage of the oscillation circuit. And a control means adapted to change the frequency.

[0017]

According to the present invention, in the above construction, the vibrating means vibrates the second mass system, and simultaneously vibrates the third mass system attached to the second mass system. At this time, the reaction force due to the vibration of the third mass system is
The mass system is subjected to load vibration. As a result, the guide pipe operates so as to cause a resonance phenomenon of the guide pipe, which causes a friction reducing effect.

According to the present invention, the third mass system is further set in addition to the second mass system. In this case, the sum of the masses of both is maintained at a constant value,
It is possible to realize desired vibration fluctuation in the guide pipe.

Further, according to the present invention, the drive circuit for the elastic member causes the phase difference between the current and the voltage for driving the elastic member to be approximately 90 °.
The frequency of the oscillation circuit is controlled as described above to deform and drive the expansion / contraction member.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the tape guide mechanism of the present invention will be described with reference to FIGS. In this example, the tape guide portion has one end 13a fixed to the base 20 and a support shaft 13 having the mass system 12 at the other free end 13b, and a guide pipe 14.
The guide pipe 14 is supported by the central portion 13c of the support shaft 13, and is fixed in a direction orthogonal to the guide pipe 14 so that the vibrator 16 does not contact the tape. The vibrator 16 is configured by using a laminated piezoelectric element. Further, in FIG. 1, 17 and 18 are flange portions for suppressing the vertical shift of the tape,
By forming the flange portion 17 with a light material, it is configured so as not to affect the vibration mode of the tape guide described later.

When an AC voltage is applied to the vibrator 16, the support shaft 13 vibrates. In this case, by vibrating at a frequency outside the appropriate audible band, for example, as shown in FIG.
A resonance state as shown in can be created. next,
The principle of forming this resonance state will be described with reference to FIG.

First, the vibrating tape guide unit 1 is used.
When 0 is approximated by a simple mechanical model, it can be modeled in the form of a cantilever having two mass systems or mass parts 22 and 24 and one end fixed ((A) in FIG. 2) (that is, Beam model with two mass systems). In this beam model, the mass system 12 on the free end side in FIG. 1 corresponds to the mass system 22, and the guide pipe 14 corresponds to the mass system 24. Further, the support shaft 13 of FIG. 1 corresponds to the beam 23,
In the cantilever beam in which the beam 23 is fixed at the fixed end portion 23a, the mass systems 22 and 24 are connected to the tip portion 2 of the beam 23.
3b and the central portion 23c of the beam.

Considering the resonance state of the beam 23, in the model shown in FIG. 2A, due to the rigidity of the two mass systems 22 and 24 and the beam 23, the two mass systems 22 and 24 are shown.
Are considered to be a first-order resonance mode (a) in which the resonance occurs in the same phase, and a second-order resonance mode (c) in which the mass systems 22 and 24 resonate in the opposite phase. In the resonance mode (c), the beam 23
The mass system 22, so that the displacement of the tip portion 23b of the
24 and the supporting position of the mass system 24 (the central portion 23
The resonance state can be realized by setting the position such that c) has the maximum amplitude. If appropriate parameters are set by such a design method, as shown in FIG.
The support position of the guide pipe 14 (center portion 13c) with both ends 13a and 13b of the support shaft 13 as shown in FIG.
Causes a resonance state with the belly.

In this resonance mode (c), since the guide pipe 14 is supported at the position of the antinode (maximum amplitude) of the vibration of the support shaft 13, the guide pipe 14 follows the antinode (central portion 13c) of the support shaft 13, Upper part 14a and lower part 14b of the guide pipe 14
Translational vibrations in which the phase of the displacement is in phase. As described above, since the vibration tape guide unit 10 is small in size and the antinode of the resonance of the support shaft 13 is used, a large amplitude can be obtained with a small amount of energy, so that the friction reducing effect can be easily obtained. it can.

Similarly, by vibrating the vibration exciter 16 at a frequency (ultrasonic wave or the like) outside the appropriate audible range, a resonance state as shown in FIG. 3B can be created. In this third-order resonance mode (d) (FIG. 2), the upper portion 14a and the lower portion 14b of the guide pipe 14 are
A rotational vibration that is displaced in the opposite direction with respect to is obtained.

In the first-order resonance mode (a), the position of the center of gravity of the entire model moves, whereas in the second-order resonance mode (c) and the third-order resonance mode (d). Since the two mass systems 22 and 24 are displaced in opposite phases,
The amount of movement of the center of gravity of the entire model is smaller than that in the first-order resonance mode (a). Therefore, it is possible to reduce not only the influence of the vibration of the tape guide unit on the surroundings but also the energy for vibrating the tape guide unit. As described above, it is possible to efficiently vibrate the guide pipe 14 with a small amount of energy, and to reduce the substantial contact area between the tape and the guide pipe 14 to form an air layer, so that a large friction reducing effect can be obtained with a small amount of energy. can get.

By the way, in the tape guide mechanism utilizing the ultrasonic vibration according to the above-mentioned embodiment, the vibrating means (vibrator 16) for vibrating the guide pipe 14 is
Since the guide pipe 14 for achieving the friction reducing effect is directly pressed by the laminated piezoelectric element and the piezoelectric element is driven by the AC voltage, the following problems may occur.

That is, (1) Since the part that vibrates greatly due to the resonance of the guide pipe 14 is constrained by the attachment of the vibrator 16, the originally set resonance phenomenon of the guide pipe 14 changes and the vibration balance is disturbed. In that case, it becomes difficult to realize an initially erroneous effective friction reduction effect. (2) Since the part that vibrates with a large amplitude is constrained by resonance due to the resonance phenomenon, a structure having sufficiently high rigidity is required as a configuration for supporting the vibrator 16 in order to secure stable displacement constraint. The size of the support mechanism must be increased. (3) When the characteristics of the expansion / contraction member change due to changes in the environment, the efficiency of energy supply by the AC voltage having a constant frequency decreases.

Therefore, a further embodiment of the present invention provides a tape guide mechanism which can effectively solve the above-mentioned problems. Next, a further embodiment of the tape guide mechanism according to the present invention will be described with reference to the drawings.

FIG. 4 is a view best showing the features of this embodiment, and is a cross-sectional view taken along the plane of symmetry of the vibrating tape guide. FIG. 5 is a top view of the vibrating tape guide. FIG. 6 is an external view of FIG. FIG. 7 is an assembly diagram of the vibrating tape guide unit.

4 to 7, 10 is a vibrating tape guide unit, which is a vibrating unit having a support shaft 13, a guide pipe 14 which is a first mass system, and a counterweight 12 'which is a second mass system. 7 and the upper flange 18 and the lower flange 17. Guide pipe 14
Has a function of guiding the tape 1 (FIG. 5) running at the tape contact portion, and is supported by the substantially central portion 13c of the support shaft 13. Further, the upper and lower flanges 18 and 17 suppress the fluctuation of the guided tape 1 in the vertical direction,
It is provided at the position of the support shaft 13 near both ends of the guide pipe 14. The flanges 17 and 18 are made of a light material, so that the vibration tape guide unit 10
Has been devised so as not to affect the vibration state of.

The counterweight 12 'is a mass system provided to maximize the vibration amplitude in the central portion 13c of the support shaft 13 supporting the guide pipe 14 at the time of resonance. Further, as will be described later, a fixed support mechanism capable of finely adjusting and vertically supporting the counterweight 12 ′ in order to balance vibration is provided with a free end 13 of the support shaft 13.
It is provided in b. This fixed support mechanism uses fixed screws 6
And a tapered hole 13k formed in the inner part of the fixing screw 6 at the free end 13b so as to receive the fixing screw 6.
And a notch 131 formed by notching up to near the depth of the tapered hole 13k, and the counterweight 1
Outer peripheral surface 13 fitted so that 2'slide up and down
j and.

When the counterweight 12 'is set to an appropriate position and the fixing screw 6 is pushed in, the end 6a of the fixing screw 6 comes into contact with the tapered hole 13k. As a result, the notch 131 of the free end 13b of the support shaft 13 is expanded and the outer peripheral surface 13j of the support shaft 13 is expanded outward,
The counterweight 12 'is securely fixed at its fitting portion.

The support shaft 13 is made of a material having a small internal damping, and is coupled and supported to the base 20 by a screw portion 13h capable of finely adjusting the vibration tape guide unit 10 up and down. The support shaft 13 further includes a large diameter portion 13f at the step portion 13d.
The shaft portion 13i is press-fitted to form a two-stage structure having the small diameter portions 13e and 13g. Thus, in the support shaft 13, the small diameter portions 13e and 13g and the large diameter portion 13f are formed.
By providing the large diameter portion 13f, the large diameter portion 13f
Since the rigidity is higher than that of 13g, the small diameter portion 13e,
It is more difficult to vibrate than 13g. That is, the large-diameter portion 13f can be regarded as the fixed end of the support shaft 13, so that even if the axial length of the large-diameter portion 13f changes a little, the resonance state of the vibrating tape guide unit 10 is not significantly affected. It has a structure like this.

The vibrating unit 7 of the vibrating tape guide unit 10 has a flat surface 1 of the counterweight 12 'at one end.
2'a is adhered and fixed, and at the other end is a third mass system 1
5 is composed of a fixed elastic member 16 '. The elastic member 16 'is an electromechanical conversion element that expands and contracts in a direction substantially orthogonal to the support shaft 13 by supplying electric power, and is composed of a laminated piezoelectric element.

Here, regarding the second and third mass systems,
This will be described with reference to FIG. 9A is the same as FIG. 2A described above, and is a model of the vibration tape guide of the two-mass system. In FIG.
24 is a first mass system corresponding to the guide pipe 14, 22
Is a second mass system corresponding to the counterweight 12 '. Reference numeral 23 is a beam that supports the second mass system 22 at the tip portion (free end) 23b, the first mass system 24 at the central portion 23c, and is fixedly supported by the fixed end portion 23a. FIG. 9A is a model of FIG. 9A in a spring mass system. In the figure, the rigidity of the beam 23 is shown by springs 23e and 23g.

Further, FIG. 9C is a model of the spring mass system including the vibrator in this embodiment.
In this (c), 32 is a counterweight 12 '
Is a second mass system corresponding to the above, 35 is a mass system corresponding to the third mass system 15 provided on the elastic member 16 ', and 36 is a dynamic rigidity of the elastic member 16'. 9D shows the resonance state in the beam model of FIG. 9C.

Here, the setting of the second and third masses will be described with reference to FIG. As shown, the second mass system 32 has a mass reduced by the mass (mass system 35) increased by adding the third mass system 15, that is, the mass system corresponding to the third mass system 15. The total sum of 35 and the second mass system 32 is approximately equal to the second mass system 22 in the tape guide using the vibration of the shaft having the initially set two mass system as shown in FIG. Is set to. Further, as shown in FIG. 9C, the third mass system 35 corresponds to the counterweight 12 ′ and the mass system 32 corresponding to the counterweight 12 ′.
It is set to be larger than.

Here, the assembly of the vibrating tape guide unit 10 will be described with reference to FIG. First, the guide pipe 14 is press-fitted and supported by the central portion 13c of the support shaft 13. Next, the flanges 17 and 18 are press-fitted and supported from above and below the support shaft 13. Further, the large diameter portion 13f is press-fitted from the lower side of the support shaft 13. Then, the counterweight 12 'provided with the vibrating unit 7 is fitted into the outer peripheral surface 13j at the free end 13b of the support shaft 13, and the fixing screw 6
Temporarily fix by.

The vibrating tape guide unit 10 assembled as described above is fitted into the screw portion of the base 20, and the whole is incorporated into the tape running system. In this case, some adjustment procedure as described below is required. 1) The heights of the flanges 17 and 18 are changed in order to apply a regulation force in the tape width direction when adjusting the tape running.
This can be performed by rotating the support shaft 13 and finely adjusting the overall height of the vibrating tape guide unit 10 in the vertical direction. Therefore, by appropriately rotating the support shaft 13, the screw portion 13h is adhesively fixed at an appropriate position where the running state of the magnetic tape is stable. At this time, the axial length of the large-diameter portion 13f of the support shaft 13 slightly changes, but as described above, it does not substantially affect the resonance state of the vibrating tape guide unit 10.

2) When the vibration tape guide unit 10 is out of balance due to a processing error or the like, the fixing screw 6 is once loosened, the counterweight 12 'is finely adjusted up and down together with the vibration unit 7, and temporarily fixed again. It can be absorbed. Then, the fixing screw 6 is adhesively fixed at a balanced position.

Next, the operation of the vibrating tape guide will be described. In the vibrating tape guide unit 10, when power is supplied to the expansion / contraction member 16 'by the resonance drive circuit, the expansion / contraction member 16' is expanded / contracted to serve as a vibration source. Therefore, first, the operation of the resonance drive circuit will be described with reference to FIG. In FIG. 8, 201 is a piezoelectric element that is an electrically capacitive element, 202 is an equivalent circuit that electrically converts the motion phenomenon of the mechanical system of the vibration tape guide including this piezoelectric element, and 203 is a resistance for current detection. An element, 204 is a voltage waveform detecting unit, 205 is a current waveform detecting unit, 206 is a phase difference between the voltage waveform and the current waveform, and an error signal is calculated so that the phase difference becomes zero at 90 °. An error calculation circuit, 207 is an oscillation circuit, and 208 is an amplification circuit.

The oscillating circuit 207 oscillates at a frequency close to the resonance frequency of the vibrating tape guide, and its output is the amplifying circuit 2.
Sent to 08. Electric power is supplied to the piezoelectric element 201 by the AC voltage of the resonance frequency amplified by the amplifier circuit 208. At this time, the expansion / contraction motion of the piezoelectric element 201 causes the resonance phenomenon of the vibration tape guide unit 10. This is equivalent to the case where the resonance phenomenon of the inductance type element and the capacitance type element occurs in the equivalent circuit 202 of FIG.

On the other hand, the current supplied to the vibrating tape guide is detected by the current detecting resistance element 203 as a voltage value, and the current waveform detecting section 205 detects the current waveform in the form of voltage displacement. The voltage waveform detector 204 detects the voltage waveform of the voltage supplied to the vibrating tape guide. The phase difference between the current waveform and the voltage waveform is calculated by the phase error calculation circuit 206, and a phase error signal that becomes zero when the phase difference is about 90 ° is calculated and sent to the oscillation circuit 207. The oscillator circuit 207 changes the oscillation frequency according to the phase error signal. As in this case, setting the phase difference between the current and the voltage to about 90 ° controls the drive frequency so that the impedance of the vibrating tape guide is maximized, that is, expanding and contracting efficiently with a small amount of power supply. The member 201 can be driven. Especially voltage element 2
Since 01 has a temperature characteristic, the characteristic changes depending on the environment. Therefore, the feedback control in the drive circuit described above can be an extremely effective means in terms of energy saving.

As described above, the expansion / contraction member 16 'which is a laminated piezoelectric element is expanded / contracted. As a result, the third mass system 15 provided on the free end side of the elastic member 16 ′ has the support shaft 13
Oscillates in a plane substantially orthogonal to. The state of vibration at this time is shown in (d) of FIG. 9. This will be explained using the spring mass system ((c) of FIG. 9). 35 and the second mass system (counterweight 12 ') 32 vibrate. In particular, by making the mass of the third mass system 35 larger than that of the second mass system 32, the second mass system 32 vibrates greatly due to the principle of the dynamic vibration reducer.

Here, the principle of the dynamic vibration absorber will be briefly described, but the principle is utilized to vibrate more efficiently. Generally, when considering the vibration of a spring-mass system, there is a dynamic vibration absorber for absorbing the vibration of the vibrating mass system. This is a mechanism in which an auxiliary second spring-mass system is attached to the vibration system of one mass system, and the vibration of the first mass system (main mass system) is absorbed by the reaction force of the vibration of the auxiliary mass system. Is. Therefore, in terms of energy, since the vibration energy of the main mass system is absorbed by the vibration energy of the auxiliary mass system, if the mass of the auxiliary mass system is smaller than that of the main mass system, conversely a large amplitude is generated. be able to.

When the principle of such a dynamic vibration absorber is applied to this embodiment, the mass balance is set so that the second mass system becomes the above-mentioned auxiliary mass system and the third mass system becomes the main mass system. By vibrating the third mass system, the second mass system can be vibrated efficiently and largely.

Further, this vibration causes the first mass system 24 to
It is intended to vibrate the (guide pipe 14). In this way, in the vibrating tape guide unit 10, the third mass system 15 is vibrated in a plane substantially orthogonal to the support shaft 13, and the counterweight 12 ′ is substantially moved to the support shaft 13 by utilizing the reaction force of this vibration. The load can be efficiently excited in the orthogonal direction.

Further, as described above, the total mass of the counterweight 12 'which is the second mass system and the third mass system 15 is the mass of the vibrating tape guide having the mass system at the tip of the support shaft 13 at the tip of the shaft. Since the mass is set to be approximately equal to the mass of the mass system, it is not necessary to change the basic design parameters. Therefore, while maintaining the originally designed resonance state, FIG.
The vibration tape guide unit 10 can be vibrated as in (d).

By vibrating the vibrating tape guide unit 10 in such a stable state and efficiently, it is possible to cause the guide pipe 14 to rotate or translate. By vibrating in this way, the substantial contact area with the guided magnetic tape is reduced, and by forming an air layer, a great friction reducing effect is obtained.

In this embodiment, the elastic member 1
Although a laminated piezoelectric element is used in 6 ', it is possible to use other electrostrictive elements or giant magnetostrictive elements that cause expansion and contraction by supplying electric power to perform load vibration due to expansion and contraction vibrations. It is possible to obtain the same effect as that of the present embodiment.

[0052]

As described above, according to the present invention, the vibrating means for vibrating the shaft is provided with the shaft having one end fixed and the tape attachment member fixed to a predetermined portion of the shaft.
In a tape guide mechanism in which the tape attachment member is oscillated and displaced, a first mass system including the tape attachment member,
A second mass system provided on the free end side of the shaft and a third mass system attached to the second mass system are set, and an elastic member that expands and contracts in a direction substantially orthogonal to the shaft is provided. The second mass system and the third mass system are coupled to each other, and the elastic member is driven by the vibration driving means, so that the second mass system is subjected to load vibration and a friction reducing effect is produced. The vibrating tape guide can be vibrated without restraining the resonance state of the tape contact member to be vibrated, the guide pipe can be freely vibrated efficiently, and significant friction reduction can be realized.

Further, according to the present invention, the total sum of the masses of the second mass system and the third mass system is held at a constant value, and
By setting the mass of the third mass system larger than that of the second mass system, the desired vibration phenomenon with good balance can be achieved without changing the basic parameters of the vibration tape guide having the mass system at the shaft tip. Can be efficiently realized, and the required friction reducing effect can be effectively realized.

Further, according to the present invention, the expansion / contraction member composed of the electro-mechanical conversion element, the drive circuit for supplying electric power to the electro-mechanical conversion element, and the vibrating tape guide including the shaft operate near the resonance frequency. An oscillating circuit, a current detecting unit of the driving circuit, a voltage detecting unit of the driving circuit, and a control unit configured to change the frequency of the oscillating circuit according to the phase difference between the detected current and voltage, Since the resonance circuit is formed so that the phase difference between the current and the voltage for driving the deforming member becomes approximately 90 °, the deforming member can be driven with less electric power, and the electric energy can be efficiently converted into vibration energy. There is an effect that can be converted. Further, there is an advantage that the environmental characteristics of the deformable member can be absorbed.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of a tape guide mechanism of the present invention.

FIG. 2 is a diagram showing an example of vibration modes in a mechanical model of a tape guide mechanism.

FIG. 3 is a diagram showing an example of a vibration mode in an embodiment of the tape guide mechanism of the present invention.

FIG. 4 is a cross-sectional view of another embodiment of the tape guide mechanism of the present invention.

FIG. 5 is a top view of another embodiment of the tape guide mechanism of the present invention.

FIG. 6 is a sectional view taken along the plane of symmetry in another embodiment of the present invention.

FIG. 7 is an exploded perspective view of essential parts in another embodiment of the present invention.

FIG. 8 is a drive circuit diagram of a vibration exciter according to another embodiment of the present invention.

FIG. 9 is a diagram showing an example of vibration modes according to another embodiment of the present invention.

FIG. 10 is a cross-sectional view of a conventional vibrating tape guide.

FIG. 11 is a diagram showing an example of a resonance mode in a conventional vibrating tape guide.

FIG. 12 is a partial plan view showing an example of a resonance mode in a conventional vibrating tape guide.

FIG. 13 is a development view of the surface of the guide pipe in the resonance mode of the conventional vibrating tape guide.

[Explanation of symbols]

 1 magnetic tape 6 fixing screw 7 vibration unit 8 mounting base 10 tape guide unit 12 mass system 12 'canter weight 13 support shaft 13a one end 13b free end 13c central portion 13d step portion 13e small diameter portion 13f large diameter portion 13g small diameter portion 13h screw Part 14 Guide pipe 15 Third mass system 16 Vibrator 16 'Expansion / contraction member 17 Flange part 18 Flange part 20 Base 22 Mass system 23 Beam 24 Mass system 201 Piezoelectric element 202 Equivalent circuit 203 Current detection resistance element 204 Voltage waveform detection Unit 205 Current waveform detection unit 206 Phase error calculation circuit 207 Oscillation circuit 208 Amplification circuit

Claims (3)

[Claims] 1. A tape splicing member having a shaft having one end fixed and a tape splicing member fixed to a predetermined portion of the shaft, wherein the tape splicing member is vibratingly displaced by vibrating means for vibrating the shaft. And a second mass system provided on the free end side of the shaft, and a second mass system attached to the second mass system. And a third mass system is set, and the second mass system and the third mass system are coupled via an elastic member that expands and contracts in a direction substantially orthogonal to the axis, and the elastic member vibrates. A tape guide mechanism characterized by being driven by a driving means. 2. The mass of the second mass system and the mass of the third mass system are held at a constant value, and the mass of the third mass system is larger than the mass of the second mass system. The tape guide mechanism according to claim 1, wherein the tape guide mechanism is set. 3. The tape guide mechanism according to claim 1, wherein the elastic member formed of an electro-mechanical conversion element, a drive circuit for supplying electric power to the electro-mechanical conversion element, and a vibration including the shaft. An oscillation circuit operating near the resonance frequency of the tape guide, a current detection unit of the drive circuit, a voltage detection unit of the drive circuit, and a frequency difference of the oscillation circuit according to a phase difference between the detected current and voltage. And a tape guide mechanism.