JP2695900B2 - Head cleaning device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary head device of a magnetic recording / reproducing device, and more particularly to a head cleaning device for cleaning the rotary head.

[Conventional technology]

In a magnetic tape recording method using a magnetic head (hereinafter, referred to as a rotating head) disposed on a rotating drum,
The rotary head is constantly susceptible to foreign matter, such as dust, dirt and oxide particles on the magnetic tape. If the rotary head continues to scan on the magnetic tape with these foreign substances attached to the rotary head, the recording / reproducing signal is extremely deteriorated. As they proceed further, these foreign substances are strongly attached to the rotating head, causing a so-called clogging phenomenon, and recording and recording on the magnetic tape.
Playback cannot be performed normally.

As described above, the clogging phenomenon is caused by the fact that the rotating speed of the rotating drum is larger and the relative speed between the rotating head and the tape is faster than that of the conventional VHS video tape recorder (VTR).
This is particularly prone to occur in inch-inch high definition VTRs. (Relative speed, VHS: 6m / s, Hi-Vision: 21m / s) Conventionally, the outer peripheral surface of the rotating drum and the rotating head are regularly cleaned by so-called manual work against the adhesion of magnetic powder and foreign matter to the rotating head. I was trying to do it. But,
In this cleaning work, every time the operator tries to perform cleaning, the machine is stopped, the upper case cover of the machine is removed, and the rotary drum is slowly rotated directly by hand, so that, for example, ethyl alcohol is impregnated. The outer peripheral surface of the rotating drum and the rotating head are wiped with a soft dust coat or the like to remove foreign substances such as dust adhering to those surfaces. This is an extremely troublesome operation for the operator, and there is also a risk of failure and damage to the rotary head.

In view of the above circumstances, various devices that can automatically perform cleaning have been proposed, for example, as disclosed in JP-B-63-29329.

Recently, a cleaning cassette with a cleaning tape wrapped around it has been prepared, and the operator regularly removes it.
There is also a way to attach it to a VTR.

[Problems to be solved by the invention]

The above-mentioned conventional technique is to prevent damage to the rotary head or the like, while the rotary drum is not rotating at high speed, that is, before the magnetic tape is wound around the rotary drum by the loading mechanism, or when the magnetic tape wound around the rotary drum is Go after being taken off. The time and pressure for pressing the cleaning member to the rotary drum are selected so as not to damage the rotary head.

However, it is hard to say that the cleaning effect is sufficiently considered.

SUMMARY OF THE INVENTION An object of the present invention is to provide a head cleaning device that sufficiently considers damage to a rotary head and life and has a high cleaning effect.

[Means for solving the problem]

In order to achieve the above object, the present invention has the following configuration.

That is, it has a rotatable rotary drum disposed so that the magnetic head protrudes from the outer peripheral surface. The outer peripheral surface of the rotary drum is located at a position outside a range where the magnetic tape is wound around a predetermined circumference of the rotary drum. A head cleaning device of a magnetic recording / reproducing device provided with a cleaning member arranged in close proximity, comprising: a vibration unit configured to vibrate the cleaning member; and an integrating unit configured to integrate a power-on time of the magnetic recording / reproducing device. When the integration time for integrating the energization time reaches a predetermined time, the vibration unit is driven to vibrate the cleaning member to perform a cleaning operation.

In addition, the rotary drum has a rotatable rotary drum disposed so as to protrude the magnetic head from the outer peripheral surface. The outer peripheral surface of the rotary drum is located at a position outside a range where the magnetic tape is wound on a predetermined circumference of the rotary drum. What is claimed is: 1. A head cleaning device for a magnetic recording / reproducing apparatus provided with a cleaning member arranged in close proximity, comprising: a vibration unit for vibrating the cleaning member; and counting the number of cleanings of the cleaning member, wherein the number of cleanings is predetermined. Cleaning number management means for indicating that the cleaning member should be replaced when the predetermined number is reached.

[Action]

In the present invention, disposing the cleaning member close to the outer peripheral surface of the rotary drum and vibrating the cleaning member allows the cleaning member to remove foreign substances and the like from the rotary head without increasing the pressure force of the cleaning member to the rotary head. Can be done effectively.

The provision of the cleaning member and the second vibrator for moving the vibrator away from the rotary head makes the timing of the cleaning operation free and appropriate, reduces damage to the rotary head, and extends the life. Contribute.

Further, oscillating the cleaning member in a substantially radial direction with respect to the rotation direction of the rotary head and disposing the initial position of the rotary head and the cleaning member at a distance equal to or less than the vibration displacement requires the second vibrator. The timing of performing the above-mentioned cleaning operation can be freely and appropriately adjusted, the damage to the rotary head can be reduced, and the life can be extended.

In addition, since the cleaning member is vibrated substantially in the circumferential direction of the rotary head, and the separation means for separating the cleaning member and the rotary head is provided, the rotation is performed in the circumferential direction, which is the direction in which the strength of the rotary head is increased. Damage to the head is further reduced, and the timing of the cleaning operation can be made appropriate.

Further, contacting the cleaning member with a piezoelectric ceramic such as barium titanate, lead zircon titanate, lead cobalt niobate, or lead bismuth niobate can be used at (1) a practical voltage. (2) High conversion efficiency. (3) Extremely stable characteristics. (4) The setting range of the resonance frequency is wide.
The configuration of the vibration of the cleaning member having such advantages as above can be simplified and made possible.

In addition, contacting a so-called bimorph type vibrator in which one end of the cleaning member is bonded to two piezoelectric ceramic thin plates using a metal elastic plate as a center electrode enables vibration at a lower voltage.

In addition, the cleaning member having a cylindrical shape and the interior of the same cylindrical piezoelectric ceramic have a very simple structure of the cleaning member with the vibrator.

Also, in the magnetic recording / reproducing apparatus, providing an integrator of the energizing time and performing the cleaning operation when the energizing time reaches a predetermined amount can prevent excessive cleaning, and is advantageous for damage to the rotating head, prolonging the service life, and the like. Becomes

In addition, when the rotation of the rotating drum is stopped, the cleaning member is sufficiently displaced when the rotation speed is low, and the displacement of the cleaning member is reduced as the rotation speed increases, which is advantageous for preventing damage to the rotation head. Becomes

In addition, by judging that cleaning is necessary by the above-described integrator, displaying on the operation panel and rotating the rotating drum at a low speed to vibrate the cleaning member prevents damage to the rotating head and effectively performs cleaning. obtain.

In addition, specifying the replacement of the cleaning member after the cleaning member has been vibrated a predetermined number of times is not only convenient for maintenance operation and the like, but also advantageous in preventing damage to the rotating head.

〔Example〕

Hereinafter, an embodiment of the present invention will be described. FIG. 1 is a schematic view of a tape running showing a relationship between a rotating drum, a head, a tape running, and the like in the vicinity of the rotating drum. The rotating drum 1 also includes a magnetic head (hereinafter, a rotating head) 2 that rotates at a high speed. Further, the magnetic tape 5
For example, it is guided by guide rollers 6 and 7 and travels in the direction of arrow 8. The cleaning member 3 is distributed rearward as shown in the drawing without affecting the range of winding the tape around the rotating drum 1. The cleaning member 3 is arranged close to the outer peripheral surface of the rotary drum 1 by an amount of protrusion of the rotary head 2 from the outer peripheral surface of the rotary drum 1, for example, an amount corresponding to 40 μm,
The vibrator 4 is configured, for example, as shown in FIG.

The cleaning member 3 is generally made of a soft material. For example, a porous polyester tape or deerskin is adhered to the surface of the cleaning member 3 and the inside thereof is made of a sponge-like material. If possible, it is supported on a U-shaped support plate 13. Behind the support plate 13, one end of the vibrator 4 is fixed.

As the vibrator 4 , as shown in FIG. 2, a laminated piezoelectric actuator 10 in which, for example, piezoelectric ceramic thin plates are laminated in multiple stages and electrodes 11 and 12 are provided is used. The laminated piezoelectric actuator 10 has a size of about 10 × 10 × 18 mm, can be driven at a practical voltage of 100 V or less, has a displacement of 20 μm, and has a self-resonant frequency of about 100 KHz. The direction of displacement is indicated by arrow 15
Shown in

The cleaning operation is performed by applying a voltage to the laminated piezoelectric actuator 10, and the cleaning member 3 vibrates at a sufficiently high frequency 100KHz with respect to the rotation frequency of the rotary drum 1 (90Hz in 1/2 inch high definition, 30Hz in VHS). I do. Therefore, the cleaning member 3 slides with the rotary head 2 many times, and the cleaning effect is much higher than that of the manual operation described above. Further, by adjusting the voltage applied to the laminated piezoelectric actuator 10, it is possible to make an optimal setting for the damage to the rotary head 2.

Another embodiment according to the present invention will be described with reference to FIGS. FIG. 3 is a schematic view of the tape running near the rotating drum. The cleaning member 3 is arranged as illustrated, and is arranged close to the outer peripheral surface of the rotating drum 1. Further, the vibrator 4 and the second vibrator 16 of the cleaning member 3
It is configured as shown in the figure. Here, the right end of the second vibrator 16 is fixed to a chassis (not shown).

The cleaning member 3 is made of a sponge-like material and has a substantially cylindrical shape with a porous polyester tape or the like affixed to the surface thereof. Is done. Behind the support plate 13, for example, one end of the laminated piezoelectric actuator 10 is fixed. The direction of the displacement is indicated by arrow 15. Further, a center electrode 19 made of a metal elastic plate and a second bimorph vibrator 16 made of piezoelectric ceramics 18 and 20 are fixed to one end of the laminated piezoelectric actuator 10 via an insulating plate 17.

The displacement direction of the second vibrator 16 is indicated by an arrow 21 and is 30 × 10
With a size of about 0.4 mm, a displacement of about 300 μm can be obtained at an applied voltage of 30 V.

The advantages of this embodiment are as follows: (1) The vibration of the vibrator 4 performing the cleaning operation and the contact timing of the rotary head 2 are properly adjusted by matching the driving phase of the second vibrator 16 and the rotation phase of the rotary drum 1. I can do it.

(2) The pressing force of the cleaning member 3 to the rotary head 2 can be adjusted by displacing the second vibrator 16 . Under the above conditions, the pressure can be made variable by varying the driving voltage from about 0 to about 10 g.

(3) The driving by the vibrator 4 and the second vibrator 16 can cause the cleaning member 3 to generate a circular vibration, and the cleaning effect is high.

And so on.

Further, another embodiment will be described with reference to FIG. FIG. 5 shows a rotary drum 1, a rotary head 2, and a cleaning member 3.
FIG. 1 is a schematic view showing the positional relationship, wherein 1 is a rotating drum, which rotates at a high speed in the direction of arrow 9. Also, the rotary drum 1 is provided with a rotary head 2 that also rotates at a high speed, and the amount of protrusion S ₁ of the rotary head 2 from the outer peripheral surface of the rotary drum ₁ is:
For example, it is 40 μm. On the other hand, the cleaning member 3
Is a substantially radial arrow 15 with respect to the rotation direction of the rotary head 2.
Vibrates in the direction of. At this time, the initial position of the cleaning member 3 is placed at a distance of S ₂ from the outer peripheral surface of the rotary drum 1.
Here, the cleaning members 3 are set so that S ₂ > S _1, and if the vibration displacement of the cleaning member 3 is S ₃ , the cleaning members 3 are arranged so that S ₃ > S ₂ .

With the above arrangement, when the cleaning member 3 is not vibrated, the cleaning member is completely separated from the rotary head 2 and the cleaning member 3 and the rotary head 2 come into contact with each other only when the cleaning member 3 is vibrated to perform the cleaning operation. Becomes Therefore, the timing of the cleaning operation can be made appropriate.

Further, another embodiment will be described with reference to FIG. FIG. 6 shows a rotary drum 1, a rotary head 2, and a cleaning member 3.
It is a schematic plan view which shows the positional relationship of. Reference numeral 1 denotes a rotary drum, which rotates at high speed in the direction of arrow 9 and includes a rotary head 2. On the other hand, the cleaning member 3 is vibrated by the laminated piezoelectric actuator 10 in a direction 22 which is a circumferential direction with respect to the rotation direction of the rotary head 2. Further, a side face of the laminated piezoelectric actuator 10 is fixed via an insulating plate 17 to a bimorph-type second vibrator 16 which is a means for separating and contacting the cleaning member 3 from the outer peripheral surface of the rotating drum 1. The displacement of the second vibrator 16 occurs in the direction of arrow 21 with the left end fixed in FIG. This displacement has a bimorph size of 30 × 10 × 0.
The size is about 4 mm and about 300 μm at a driving voltage of 30 V, which is sufficient for the protrusion amount of the rotary head 2 of about 40 μm.

The advantages of this embodiment are as follows: (1) Since the vibration of the cleaning member 3 is in the direction in which the strength of the rotary head 2 is increased, damage to the rotary head is small. In addition, since foreign matter and the like easily adhere to the longitudinal direction of the rotary head 2 and slide the cleaning member 3 in that direction, the cleaning effect is high.

(2) The pressure, timing, and the like of the cleaning member 3 can be appropriately adjusted.

And so on.

Further, another embodiment of the structure of the cleaning member 3 and the vibrator 4 will be described with reference to FIG.

The cleaning member 3 is generally made of a soft material, such as a porous polyester tape, deerskin, flocked fiber,
A woven cloth or the like made of fine fibers is adhered, and the inside is formed of a sponge-like inner cylinder 22. The inner cylinder 22 is impregnated with, for example, a cleaning liquid such as ethyl alcohol.

At one end of the cleaning member 3, barium titanate, lead zirconium titanate, cobalt cobalt niobate, lead bismuth niobate, and other lead metaniobate, which are piezoelectric ceramics,
Polarization treatment of a piezoelectric material such as polyvinylidene fluoride
The vibrators provided with 1, 12 are abutted and fixed. In the illustrated configuration, the vibrator vibrates in thickness and the cleaning member 3 is displaced in the direction of arrow 15. The advantage of this embodiment is that the structure is extremely simple compared to the previous example.

Further, another embodiment will be described with reference to FIG. The cleaning member 3 has the same configuration as that described above, and is in contact with a so-called bimorph vibrator in which one end of the cleaning member 3 is bonded to two thin plates of piezoelectric ceramics 18 and 20 having a metal elastic plate 19 as a center electrode. Fixed. In the illustrated configuration, the vibrator moves the cleaning member 3 in the direction of arrow 21. The advantage of this embodiment is that it can be driven at an extremely low voltage compared to the above-described example.

Further, another embodiment will be described with reference to FIG. The cleaning member 3 has the same configuration as described above, and has a cylindrical shape different from the above-described one.
The interior is decorated. The cylindrical piezoelectric ceramic 23 is provided with electrodes on the inner circumference and the outer circumference and performs respiratory vibration. The advantages of this embodiment are that the structure of the cleaning member 3 is simplified to a circular shape, which is simple, and that the vibration for the above-described cleaning operation is also possible.

FIG. 10 shows another embodiment in which the structure of the vibrator is changed.
This will be described with reference to FIG. In FIG. 10, the cleaning member 3 is
The configuration is the same as that described above, and the laminated piezoelectric actuator 10 is abutted and fixed so that the direction of vibration is substantially circumferential with respect to the rotary head 2.

FIG. 11 shows an example in which a laminated piezoelectric actuator 24 is further fixed as a means for separating and approaching the rotary head 2 from the example of FIG. The advantage of this embodiment is that the cleaning effect is high and fine control is possible.

Further, an embodiment using a vibrating cleaning member according to the present invention and an integrator of energization time in a magnetic recording and reproducing apparatus will be described with reference to FIG.

In general, as described in the section of the related art, the cleaning operation is performed periodically, and may be excessive when performed every time recording and reproduction are performed. Normally, VHS system VTRs are performed every 30 hours, and every 10 hours even if excessive use is considered for business use. Therefore, the energization time integrator 27 informs the drive circuit 28 of the vibrator of the cleaning member 3 that the predetermined amount has been reached, and vibrates the cleaning member 3 only at this time, or the cleaning member 3 is moved by the separation / contact means. The contact with the rotary head 2 is performed.

Next, an embodiment in which the vibration displacement of the cleaning member 3 according to the present invention is applied in accordance with the rotation speed of the rotating drum in the magnetic recording / reproducing apparatus will be described with reference to FIG. As described in the section of the prior art, the cleaning operation must be avoided as much as possible while the rotary drum 1 is rotating at a high speed in order to prevent the rotary head 2 from being damaged. On the other hand, the rotation speed of the rotating drum 1 is
Before the magnetic tape is wound around the rotating drum 1 by the loading mechanism, it rises from 0 and reaches a normal rotation speed as shown in FIG. 13 (1).

Therefore, for example, if the drive voltage to the vibrator of the cleaning member 3 is changed as shown in FIG. 13 (2), the vibration displacement of the cleaning member 3 decreases as the rotation speed of the rotary drum 1 increases. That is, as the rotating head 2 rotates at a higher speed, the cleaning member 3 is lightly moved to the rotating head 2.
, Which is advantageous for preventing damage to the rotary head.

Next, an embodiment in which a cleaning mode is provided in the magnetic recording / reproducing apparatus will be described with reference to FIG.

The integrator 27 counts the energizing time to the magnetic recording / reproducing device, and inputs to the microprocessor 33 that a predetermined amount has been reached. Next, the microprocessor 33 illuminates the indicator 32 provided on the operation panel 31 to clearly indicate that it is in the cleaning mode (performing the cleaning operation). At the same time, the rotating drum 1 is rotated at a low speed. Further, the cleaning member 3 is vibrated. When the above operation reaches a predetermined time, the microprocessor 33 stops the cleaning mode.

When the cleaning mode is repeated a predetermined number of times, the cleaning member 3 becomes soiled.
The indicator 34 provided on the operation panel 31 is turned on to clearly indicate that the cleaning member 3 needs to be replaced.

In the embodiment described above, an example in which the piezoelectric ceramic is used as the vibrator or the separation / contact means is described. However, it goes without saying that a voice coil, a solenoid, a motor, or the like using an electromagnetic force may be used as another actuator. No.

〔The invention's effect〕

As described above, according to the present invention, it is possible to provide a head cleaning device that sufficiently considers damage to the rotating head, life, and the like and has a high cleaning effect.

[Brief description of the drawings]

FIG. 1 is a schematic plan view of tape running according to one embodiment, FIG. 2 is a perspective view showing a cleaning member with a vibrator,
FIG. 3 is a schematic plan view of tape running according to another embodiment,
FIG. 4 is a perspective view showing a cleaning member with a vibrator, and FIG. 5 is a schematic plan view showing the relationship between the amount of protrusion of a rotary head and the vibration displacement of the cleaning member according to another embodiment.
FIG. 6 is a schematic plan view showing the relationship between the vibration and the direction of separation and contact of the cleaning member and the rotary head according to another embodiment, and FIGS.
FIGS. 9, 10, and 11 are perspective views showing a cleaning member with a vibrator according to another embodiment. FIGS. 12 and 14 are block diagrams showing the configuration of a magnetic recording and reproducing apparatus according to an embodiment using an integrator.
FIG. 13 is a time chart showing the relationship between the rotation speed of the rotating drum and the drive voltage applied to the vibrator according to the embodiment. DESCRIPTION OF SYMBOLS 1 ... Rotating drum, 2 ... Rotating head, 3 ... Cleaning member, 4 ... Vibrator, 10 ... Laminated piezoelectric actuator, 16 ... Second vibrator, 27 ... Integrator, 33 ...... Microprocessor.

Claims (2)

(57) [Claims] A rotatable rotary drum disposed so as to protrude a magnetic head from an outer peripheral surface, wherein the rotary drum is located at a position outside a range where a magnetic tape is wound around a predetermined circumference of the rotary drum. What is claimed is: 1. A head cleaning device for a magnetic recording / reproducing device having a cleaning member disposed close to an outer peripheral surface, comprising: a vibrating unit for vibrating the cleaning member; and an integrating unit for integrating an energizing time of the magnetic recording / reproducing device. A head cleaning device comprising: when the integration time for integrating the energization time reaches a predetermined time, the vibration unit is driven to vibrate the cleaning member to perform a cleaning operation. And a rotatable rotary drum disposed so that a magnetic head protrudes from an outer peripheral surface thereof. The rotary drum is provided at a position outside a range where a magnetic tape is wound around a predetermined circumference of the rotary drum. What is claimed is: 1. A head cleaning device for a magnetic recording / reproducing apparatus having a cleaning member disposed close to an outer peripheral surface, wherein a vibration means for vibrating the cleaning member, and the number of cleanings of the cleaning member are counted. And a cleaning number management means for indicating that the cleaning member should be replaced when the number reaches a predetermined number.