JPS6047271A - Floating head - Google Patents

Abstract

PURPOSE:To attain high speed fine positioning due to a drive element in addition to a low speed rough positioning by a slider by inserting a drive element moving minutely a head main body in a parallel direction of an informing track between the slider and the head main body. CONSTITUTION:A laminated type piezoelectric element 22 is mounted to a notch of the slider 21. The element 22 is constituted of plural piezoelectric material layers 23 fixed and overlapped alternately and an electromagnetic layer 24 and an insulation layer 25 is inserted between notched wall faces. Each electromagnetic layer 24 is connected alternately to a power supply via voltage impressing terminals 26, 27 and constituted so that the thickness of the element 22 is changed by nearly 1% by the voltage. An optical head 10 is adhered to the end face in the broadwise direction of the element 22. Through the constitution above, the low speed rough positioning of the optical head 10 is conducted by the movement of a head arm by the drive of actuator and in applying a voltage to the element 22, the element is moved in the broadwise direction and the positioning of the optical head with high speed and accuracy is conducted.

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a method for reproducing the recorded information by floating information on the record carrier optically or magnetically while keeping a desired gap in the air above the record carrier. It is related to floating heads.

[Prior art]

As a type of head used in information recording and reproducing devices,
When the record carrier rotates, the air flow generated on the surface of the carrier is used to float the ax-punching head, which uses the air flow generated on the surface of the record carrier to fly the white part of the secret song. This is a perspective view of the vicinity of the head of an optical recording/reproducing apparatus using this type of floating head. A plurality of annular track guide grooves 2 arranged concentrically in parallel are provided on the surface of the shaped optical disk 1, and a recording material 3 is recorded on the bottom surface of each guide groove 2. The head arm designated by reference numeral 4 is supported horizontally with its tip facing above the outer circumference of the optical disc 1, and is driven by an actuator (not shown) to move in the radial direction of the optical disc 1 as shown by reference numeral B in the figure. A head assembly, generally designated by reference numeral 5, has a gimbal spring 6 fixed thereto by a set screw T at its distal end. The gimbal spring 6 is made of an elastic plate material, and has a narrow support piece 6a and a frame-shaped support member 6b supported at both ends by the support piece 6a, integrally formed at the tip thereof. A slider 8 having a U-shaped cross section is inserted from below into a pair of square holes provided in 6b. Reference numeral 9 denotes a load arm made of a plate spring material having a U-shaped cross section and having its base end fixed to the central projecting piece 6c of the gimbal spring 6, and is pressed from above between both square holes of the support member 6b by elasticity. The slider 8 is urged toward the optical disk 1 together with the support member 6b. A plate-shaped optical head 10 is attached to the side surface of the slider 8. is pasted, and from now on, a light spot 11 is irradiated onto the recording layer 3 within the guide groove 2.

When the optical disk 1 rotates at high speed in the direction of the arrow with respect to the head assembly 5 in a stationary state, the optical spot 11
The recording material 3 is read one after another. In this case, the slider 8 is floated by a compressed air flow generated between the optical disc 1 and the slider 8 as the optical disk 1 rotates, and the elasticity of the load arm 9 restricts a minute gap in the floatation.

During such a reading operation, when the head arm 4 is driven by the actuator and moves back and forth in the direction of arrow B, the slider 8, which is in pressure contact with the gimbal spring 6 by floating, moves in the same direction, and the slider 8 moves in the same direction and presses against the gimbal spring 6, which is integrated with the head arm 4. The optical head 1a selects one of the provided track guide grooves 2 for information, and just focuses the light spot 11 on the information material 3.

However, in the above-mentioned conventional floating head, the optical spot 11 of the optical head 10 is moved and positioned using only a linear or oscillating type actuator, so the l/rack density is extremely high, 0.1 W or less. The drawback is that it is difficult to handle positioning that requires high precision.

[Summary of the invention]

The present invention has been made in view of the above points, and it is possible to perform low-speed coarse positioning by the slider moving together with the head arm by attaching the head body to the slider via a drive element that moves the head body slightly in the parallel direction of the tracks. Another object of the present invention is to provide a floating head that enables high-speed and precise positioning using a driving element and improves positioning accuracy. below,
Embodiments of the present invention will be described in detail with reference to the drawings.

〔Example〕

This embodiment shows an example in which a floating head according to the present invention is implemented in an optical recording/reproducing apparatus, and FIG. 2 is a perspective view of a slider, a laminated piezoelectric element supported by the slider, and an optical head. The support structure for the slider 21 shown in FIG. 2 is the same structure as the conventional device shown in FIG. 1, so a detailed explanation thereof will be omitted, and only an outline will be explained below using the same figure. That is, the support member 6b of the gimbal spring 6, which is fixed to the head arm 4 that moves forward and backward in the direction of arrow B by an actuator, is provided with a pair of square holes, and the slider 21, which has a U-shaped cross section, is The load arm 9 is inserted into a square hole from below and urged toward the optical disk 1 by the elastic force of the load arm 9.

Due to its function, the gimbal spring 6 has low rigidity in the floating direction of the slider 21, that is, in the focal direction of the optical spot 11, and in the parallel direction of the track guide grooves 2 and in the running direction A of the optical disc 1. It has high rigidity. The load arm 9 also has the function of determining the attitude and flying height of the slider 21.

One of the pair of square hole retaining members 21b and 21c that protrudes upward from the slider 210 and the base plate 218 has one end cut out in the shape of a rectangular parallelepiped. A laminated piezoelectric element is installed as a driving element. This laminated piezoelectric element 22 is composed of a plurality of piezoelectric material layers 23 and an electromagnetic layer 24 which are stacked alternately and fixed by sintering or the like, and an insulating layer 25 is provided between the notch wall surface and the plurality of piezoelectric material layers 23 and an electromagnetic layer 24. It is interposed. Each electromagnetic layer 24 is alternately connected to a power source via voltage application terminals 26 and 27, and is configured such that the thickness of the multilayer voltage element 22 changes by about 1% depending on a voltage of about 200 V, for example. . An optical head 1° similar to the conventional one is attached to the end face in the thickness direction of the laminated voltage element 22, and its light spot 11 is irradiated onto the recording material 3 of the optical disc 1.

In the reading operation using the floating head configured as described above, the head arm 4 is driven by the actuator.
When the information head 1 moves forward and backward in the direction of arrow B, the slider 21 moves in the same direction, and the optical head 10 selects one of the guide grooves 2 to just focus the light spot 11 on the information Hamura 3. In this case, low-speed coarse positioning of the optical head 10 is performed by moving the head arm 4 driven by an actuator, and when a voltage is applied to the laminated voltage element 22, it moves slightly in the thickness direction, allowing high-speed and precise positioning of the optical head. It is done.

In this embodiment, the optical head 10 is used as an example of the head body, but a magnetic disk and a magnetic head may be used instead of the optical disk 1 and the optical head 10. This magnetic head is designated by the reference numeral 28 in FIG. Further, in this embodiment, an example was shown in which the optical head 10 was arranged on one side of the slider 21, but the optical head or the magnetic head was placed on the slider 21.
They may be arranged according to the two rules.

FIG. 4 is a perspective view showing another embodiment of the present invention corresponding to FIG. 2, and in this embodiment, a piezoelectric element called a bimorph type is used.

That is, on both sides of the slider 21, there is a metal plate 29 and a pair of piezoelectric plates 30, 3 attached to both sides with the polarization directions aligned.
1 is provided, and the optical head 10 is connected to the tip thereof. The action is second
Although it is the same as the embodiment shown in the figure, the bimorph type piezoelectric element shown in this embodiment is characterized in that the amount of displacement is larger.

〔Effect of the invention〕

As is clear from the above description, according to the present invention, a driving element is interposed between the slider and the head body, and the head body is configured to be slightly moved in the parallel direction of the information tracks by applying a voltage. By doing this, in addition to low-speed coarse positioning using the head arm, the head body can be precisely positioned at high speed, which significantly improves positioning accuracy and can handle information sequences with extremely high track density. Since the head directly drives the head body, no vibration occurs and positioning accuracy is further improved. Furthermore, the drive element can be made lightweight and highly rigid, improving responsiveness.

[Brief explanation of drawings]

Figure 1 shows conventional optical recording using a floating head.
FIGS. 2 to 4 are perspective views of the vicinity of the head of the playback device, and FIG. 4 shows an embodiment of the floating head according to the present invention, and FIG. 2 is a perspective view of the slider, the laminated piezoelectric element supported by the slider, and the optical head. 3 are perspective views of the magnetic head, and FIG. 4 is a perspective view showing another embodiment of the present invention corresponding to FIG. 2. 1--e optical disc, 2--fist track guide groove, 1
0...Optical head, 21...Slider, 22...
・Laminated piezoelectric element, 28...Magnetic head, 32
····Piezoelectric element. Patent Applicant: Masaki Yamakawa, Agent for Nippon Telegraph and Telephone Public CorporationContinued from page 10 Inventor: Kikuji Kato Inside the Communications Research Institute, 3-1 Midoricho, Musashino City

Claims (1)

[Claims] A drive element is interposed between a slider that floats close to the surface of a traveling record carrier and a head body attached to this slider, which moves this head body slightly in a direction parallel to the information tracks on the record carrier. A floating head that is characterized by