JPS60147926A - Magnetic head drive element - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a technology for recording devices such as VTRs and other magnetic recording devices. It is about king technology.

BACKGROUND TECHNOLOGY Nowadays, VTRs are capable of recording and playing back for long periods of time even for general home use. The reason for this is that it has become possible to make the recording density extremely high. However, on the other hand, the recording track width has been set to be extremely narrow, so especially in the case of reproduction, the magnetic head can accurately read the narrow track 1. The output signal of the servo drive system of the recording medium is used to scan along the
Troubleshooting and kinging are performed to correct the position of the magnetic head. That is, as shown in FIG. 1, 1. The base plate 2 to which the head 1 is fixed is attached to the rotating drum 4 of the VTR via the flat ring-shaped bimorph piezoelectric element 3, and a signal voltage from the heather drive system is applied to the piezoelectric element 3 to displace the magnetic head 1. A mechanism has been set up to make this happen. Note that the use of the piezoelectric element 3 is disclosed in, for example, Japanese Patent Application Laid-Open No. 52-117603 and Japanese Patent Application Laid-Open No. 58-13932.
It has been publicly known in Publication No. 9, etc., and its own explanation will be omitted.

Now, by adopting the above-mentioned tracking mechanism,
VTRs are capable of variable-speed, noiseless playback in the conventional playback mode, and are unsuitable when higher-speed variable playback is required, as is the case these days. In this case, it is necessary to increase the medium feeding speed to 5 times or more, and the response of the bimollev piezoelectric transducer is at its limit.Moreover, as the amount of displacement increases, the operating voltage becomes cylindrical, making it unnecessary when applying it. Pulse-like noise may occur.

Furthermore, there was a defect in that the displacement hysteresis characteristic of the bimorph piezoelectric element increased and the control accuracy decreased.Purpose of the InventionThe present invention eliminates the above-mentioned conventional defects and provides good high-speed variable reproduction. The purpose is to realize this.

That is, the present invention is a technology that not only satisfies the functions of a conventional tracking mechanism using a piezoelectric element, but also provides a tracking function that satisfies the requirements even in the playback mode.

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present invention provides an apparatus for displacing a head chip by applying a voltage to a piezoelectric element of an actuator equipped with a base plate having a (1a) head chip. The piezoelectric layer is a laminated piezoelectric element, and a displacement magnification mechanism is provided that cooperates with the laminated piezoelectric element.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a schematic side view of a magnetic head drive element showing a first embodiment of the present invention. It is something. ``First of all, this element is used for VTR rotation 1.'ram-in.

A block piece 10 is fixed to the block piece 10, one end is fixed to the block piece 10, and a base plate 2 is attached to the released other end,
It consists of a bendable leaf spring type arm 11. The arm 11 has a rigid wall portion 12 on the fixed end side of its back.
, and then the notch part 13 and the protrusion gl (1
4 is formed.

Furthermore, the four parts 1 between the rigid wall part 12 and the projection part 13 are
5 and the recess flj z 6 between the projections 13 and 14, elongated prismatic laminated piezoelectric elements 17 and 18 are fitted.

Here, the laminated piezoelectric elements 17 and 18 have a schematic configuration as shown in FIG. That is, in FIG. 3, 19, 1.9. . . . is a piezoelectric ceramic sheet 1- such as 'pbzro or PbT 03 which has extremely large magnetostriction, and has a conductive layer 20 on its upper and lower surfaces.
,20. ... is formed. Furthermore, piezoelectric ceramic rift sheet 19.1'9. ... are laminated and bonded together to form a laminated column 21. The laminated column 2゛1 formed in this way has the terminal side surfaces of the conductive layers 20, 20°... on every other side on both sides 22, 23, and the side surfaces 22 and 23 are alternated. Insulators 24, 24°...and 25, 25.・・・
... is covered with. Then, on the exposed side surface 22.28 of the laminated column 21, the outer t'; IS conductive 4? i26,2
7 are provided, and are connected to the electrodes of the drive power source 28, respectively.

Now, regarding the magnetism of the structure explained above, 1. Next, a case will be described in which high-speed variable reproduction is performed in a VTR using a drive element. First, as shown in Figure 4, 171'! , residence
;-+"f-seat carpet tlr\earth;;'7Jfo'aj-
+/--'Jy3J'' ゎb璽ThWhen variable to high speed, the amount of movement of the magnetic head gradually changes to arrows 29, 80,
This will increase to 31.82. In FIG. 4, 33 indicates the position of the magnetic head in normal running condition, 84,
84 degrees... is the entire position of the bidet rack 1 on the magnetic tape. Therefore, the output signal for high-speed running is V
']' When sent from the servo system of
The drive source 18, that is, the drive power supply 28 shown in FIG. 3 is turned on. Then, in FIG. 3 again, the laminated piezoelectric elements 17, 18 are connected to every other conductive layer 20, 20°, which is connected to the external conductive type 4'711-26, and to the external conductive electrode 27, respectively. Every other conductive idiot 2
0', 20. . . . 1.11 electric current is applied between each piezoelectric ceramic leaf sheet 19. '19. Electric fields E, w', w, E' are generated alternately in opposite directions. Then each piezoelectric ceramic, comb -1-19°, 19
Buddha distortion 4 due to electric fields E and E' in ゜...
) Mi, -1':r^+lff-51/Iyama 艮.

Therefore, the magnetic nodal drive element in FIG.
The laminated piezoelectric elements 17, 18 extend as shown by arrows 35, 36 and act on the protrusions 1b18, 14, causing the arm 11 to curve. Therefore, the magnetic field attached to the tip of the arm 11 causes the dot 1 to be displaced along the arrow 37, increasing the amount of movement. If the magnetic head drive gear described above is installed in January in this way, and the paulownia material of the arm 11 is made of high-speed steel and the voltage of the drive power source 28 is about 100V, the amount of displacement is about 40 times the amount of movement. 5 and 6 show a magnetic head drive according to a second embodiment of the invention. It is a top view and a side view of IL11 element. In this case, the base plate 2 has a fixed plate 1"
One end is fixed to the spring 41, and the other end is attached to the release end of the leaf spring 41, which is the release end. The flat spring 41 is supported by a flat spring 42 which intersects with the flat spring 41 at a curved angle. Further, the leaf spring 42 has its both ends parallel to the leaf spring 41, and each release tip 45 of the L-shaped arms 43 and 44, which are oppositely arranged
and 46, and is constructed. Then, the other ends 47 and 48 of the arms 43 and 44 are opposed to each other with a small distance between them, and are connected to a thin hinge 441S 49.
, 50, and is connected to a U-shaped holding portion 51.

Moreover, each of the other ends 47 and 48 is held fully even at the closest part.
(The hinge jXl extends to the recessed space 55 surrounded by 51!
58 and 54, and the hinge portions 53 and 54 are joined together to form a protrusion 56 at the point where they enter the recessed space 55. And 51j:, concave j1.1! , N: 1/Ck4? between the holding part 51 and the protrusion 56 at the u interval 55? It is a laminated piezoelectric element that is inserted into the body. This (L') layer Jy1.J piezoelectric crystal 57 operates on the same principle as that shown in the first embodiment, and has 4E'tλ heads per peak, which will be explained next. It is possible to enlarge and move 1.

In other words, the pressure applied to the drive layer 57 is 1.
11, since the holding portion 51 is fixed by the fixed block 40, it presses the protrusion 56 by the amount of expansion of the 8d type pressure element-r57. Then, the pressing force applied by the protrusion 56 is applied to the arm 48 via the tip s5g, 54.
．． The arrow 58.59 separating the other ends 47, 48 of 44 and the direction of the arrow 60.61 in which the hinge portions 49+, 50 contract are dispersed and act. As a result, the free tips 45 and 46 of arms 43 and 44 move toward each other with arrows 68.
64, and the leaf spring 42 moves in the direction of 64 as seen in FIG.
As a result, the leaf spring 41 is pushed up, and the magnetic head 1 is displaced as shown by the arrow 65.

In this second embodiment, due to the design of the arms 43 and 44, the displacement of the laminated piezoelectric element 57 is approximately 200 times larger than that of the housing.
It is possible to move the magnetic head 1 in an enlarged manner.

Furthermore, FIGS. 7 and 8 are a plan view and a side view of a magnetic head driving element showing the third performance (n pieces) of the present invention;
This is, so to speak, the amount of design change in the embodiment.

The base plate 2 is attached to the tip of the temporary spring 7o,
The leaf spring 70 is cantilevered onto a fixed block 71. Furthermore, the handling spring 7o is supported at its center by holding. The arm 73 is connected at its rear end 75 to a traction piece 76 .

Then, the pulling piece 76 is held by the hinge part 77, and the pulling piece 76 is held by the hinge part 77.
2, and is connected to one end of the stacking pressure element 79 at the hinge portion 78. In addition, the laminated pressure “Ichihaya Motoko 79”
The other end is connected to a hinge 80 of the retainer 72. Therefore, in this case as well, when the laminated piezoelectric element 79 is set to 1111, the arrows 81, 82, 88
, 84 directions are applied 1 to cause the magnetic head 1 to expand and move.

Effects of the Invention As is clear from the above embodiments, when the present invention is carried out, the dynamic voltage is significantly lower than when using a conventional bimorph piezoelectric element, since a laminated piezoelectric element is used. In fact, it only takes a few minutes of -1 electricity. Further, according to the present invention, by cooperating the stacked Ay pressure, the accumulation j' and the expansion mechanism, the media speed (!'i speed IJ,
It can be confirmed that sufficient responsiveness can be obtained even when the speed is 1. Furthermore, the displacement hysteresis characteristic of fl"F layer (Su1 Yotoyo Tekata 18 settlements, Mu af1 force's t lower layer T4+'73, Kusheet's displacement hysteresis characteristic is small, and it goes without saying that the tracking control accuracy will not decrease. It is.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a rotating drum for explaining the magnetic head attachment in a conventional V and TR, and FIG. 2 is a schematic one-dimensional view of a magnetic head drive element showing a first embodiment of the present invention.
FIG. 3 is a conceptual diagram showing the schematic structure of a laminated piezoelectric element, which is one of the components of the present invention, and FIG. 4 is a schematic plan view of the medium showing the high-speed feeding state of the recording medium related to the present invention. 85 and 6 are a plan view and a side view of a magnetic head driving element showing a second embodiment of the invention, and FIGS. 7 and 8 are a top view and a side view of a magnetic head drive element showing a third embodiment of the invention. - A plan view and a side view of the horizontal drive element. 1...Magnetic head, 2...Base plate,
lO...Block piece, 11...Arm, 1
7.18...Laminated piezoelectric element, 19.19.・・・
・・・・・・Piezoelectric ceramic sheet, 21 ・・・・・・
Laminated column, 41.42...
, 48.44...Arm, 51...Holding part, 5
7... Laminated piezoelectric element, 70... Handling/Knead, 72... Holding professional, Tsuk, 73...-Arm, 79... Laminated piezoelectric element. Figure 1 Figure 3 Figure 4, 5:5 Figure Figure 5

Claims (1)

[Claims] In a device for displacing a magnetic head chip by applying voltage to a piezoelectric element of an actuator to which a base plate to which a magnetic hesode tip is fixed is attached, the piezoelectric element is a laminated piezoelectric element, and the piezoelectric element cooperates with the laminated piezoelectric element. An emotional head drive element characterized by being provided with a displacement magnifying mechanism.