JPH0521319U - Rotating head device - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent changes in spacing loss and azimuth angle due to head movement when the head is displaced using a piezoelectric element for automatic tracking. A plate-shaped piezoelectric element plate 3 having one end supported, and a leaf spring member 4 fixed to the other end of the piezoelectric element plate and having elasticity in the extending direction of the piezoelectric element plate are provided. The other end of the leaf spring member is fixed. And the magnetic head 2
Fixes the magnetic head to the connecting portion between the leaf spring member and the piezoelectric element plate. The fixed portion of the magnetic head is located approximately in the middle of the support portion of the piezoelectric element plate and the support portion of the leaf spring member.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary head device having a head displacement function provided in a video tape recorder or the like.

[0002]

[Prior Art]

 A technique called dynamic tracking, which displaces the magnetic head at a right angle with respect to the trace direction, has been put to practical use in order to eliminate the noise generated during special playback. For example, as shown in FIG. 3, a magnetic head is fixed to the tip of a head support plate by a bimorph, and a voltage is applied to the bimorph to displace the bimorph and displace the position of the magnetic head.

However, in the configuration as shown in FIG. 3, the height of the magnetic head is displaced as shown in FIG. 4, so that the distance between the tape and the head becomes longer, which is disadvantageous in terms of reproduction output (a spacing loss occurs). There is a drawback.

For the purpose of solving this point, Japanese Patent Laid-Open Publication No. 1-232514 (G11 B5 / 592) proposes a configuration as shown in FIG. In the configuration of FIG. 5, the normal line direction of the outer peripheral surface of the rotary drum, that is, the magnetic tape surface at the magnetic head contact position and the boundary line between the support base and the head support plate are substantially parallel. Therefore, as shown in FIG. 6, the gap between the tape and the head is made substantially constant regardless of the head displacement.

[0005]

[Problems to be solved by the device]

 However, in the configuration shown in FIG. 5, as can be seen from the front view shown in FIG. 6, the same result is obtained as the azimuth angle of the magnetic head is changed. May occur.

[0006]

Therefore, in the present invention, in the present invention, a plate-shaped piezoelectric element plate having one end supported, and an elastic member in the extending direction of the piezoelectric element plate fixed to the other end of the piezoelectric element plate. And a other end of the plate spring member is fixed. The magnetic head fixes the magnetic head to the connecting portion of the leaf spring member and the piezoelectric element plate. The fixed portion of the magnetic head is located approximately in the middle between the support portion of the piezoelectric element plate and the support portion of the leaf spring member.

[0007]

[Action]

 When a voltage is applied to the piezoelectric element plate, the piezoelectric element plate tends to deform in a direction orthogonal to the direction from the fixed end to the free end according to the voltage. At this time, since the leaf spring member has elasticity in the extending direction of the piezoelectric element, the deformation of the piezoelectric element plate is allowed and the magnetic head is given a predetermined displacement. The rate of change of the azimuth angle is smaller than that in the conventional example in which the other end is completely free because of the leaf spring member.

[0008]

【Example】

 An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a perspective view showing the structure of the embodiment, and FIG. 2 is an explanatory view for explaining the movement of the magnetic head in the embodiment.

In FIG. 1, a recording / reproducing magnetic head 2 is mounted on a plate spring member of a plate-shaped head support plate 14 composed of a piezoelectric element plate 3 and a plate spring member 4. The respective ends of the piezoelectric element plate 3 and the leaf spring member 4 are adhesively fixed on the support base 6 so as to be sandwiched between the support members 5 as fixed ends.

The support base 6 is installed on a rotary drum 7 such as a video tape recorder. At this time, the magnetic head 2 is mounted so that the tip of the magnetic head 2 slightly projects from the window 8 of the rotary drum 7. .. A magnetic tape (not shown) is wound around the outer peripheral surface 11 of the rotary drum 7 as in the conventional example, and the magnetic head 2 rotates together with the rotary drum 7 to record / reproduce signals on the magnetic tape. ..

A joining line 10 (in the direction of the arrow D) between the piezoelectric element plate 3 and the leaf spring member 4 forming the head support plate 14, an area where the piezoelectric element plate 3 and the leaf spring member 4 and the support base 6 are fixed. Boundary lines 9 and 9 (directions of arrows E and F) are substantially parallel to the normal line direction (direction of arrow A) of the tangent plane to the outer peripheral surface 11 of the rotating drum at the recording position of the magnetic head 2 and the magnetic tape. It The piezoelectric element plate 3 of the head support plate 14 and the plate spring member 4 may be fixed to the support base by screwing the support member 5 to the support base 6.

As shown in FIG. 1, the leaf spring member 4 is devised in shape so as to have elasticity in a direction orthogonal to the joining line 10. That is, the flat spring meanders in the same plane in the extending direction. As another shape, a corrugated leaf spring shape can be considered. In other words, it has a meandering shape in a direction orthogonal to the extending direction.

When the piezoelectric element plate 3 is deformed as a result of the piezoelectric element plate 3 and the above-described plate spring member 4 being joined by adhesion or the like, the movement of the magnetic head 2 is restricted by the regulation of the plate spring member 4. Can be approximately parallel to the axis of the rotating drum. The magnetic head is located approximately in the center between the supports 5.

That is, when a predetermined voltage is applied to the piezoelectric element plate 3, due to the piezoelectric action, bending occurs at the joining line 10 of the leaf spring 4 beyond the boundary line 9 with the support base 6. At this time, the plate spring member 4 connected to the piezoelectric element plate 3 also expands and bends from the joining line 10 to the boundary line 9 with the support base 6, and the magnetic head mounted on the plate spring member 4 also moves.

At this time, as shown in FIG. 2, the piezoelectric element plate 3 constituting the head support plate 14 is surrounded by a boundary line 9 provided in parallel with the normal direction of the magnetic tape surface (direction of arrow A). Since the boundary line 9 (arrow F direction) between the plate spring member 4 and the support 6 joined to the piezoelectric element plate 3 at the boundary line 10 is substantially parallel to the A and D directions, respectively, the magnetic head 2 Drive within a range of substantially equidistant from the magnetic tape surface. Further, by appropriately selecting the deflection amount of the piezoelectric element plate 3 and the mechanical characteristics of the leaf spring 4, the magnetic head 2 mounted on the leaf spring member 4 is driven substantially parallel to the rotation plane of the rotary drum 7. Can be done. Therefore, the distance between the magnetic head 2 and the magnetic tape and the azimuth angle can be made constant even during the automatic tracking operation.

[0016]

[Effect of the device]

 As described above, according to the present invention, the change of the azimuth angle is restricted by the leaf spring member, so that the change of the azimuth angle is suppressed even during the automatic tracking operation, and there is no fear that the reproduction output is lowered.

[Brief description of drawings]

FIG. 1 is a perspective view showing a configuration of an example.

FIG. 2 is an explanatory diagram for explaining the movement of the embodiment.

FIG. 3 is a perspective view showing a configuration of a conventional example.

FIG. 4 is an explanatory diagram for explaining movement in a conventional example.

FIG. 5 is a perspective view showing a configuration of a second conventional example.

FIG. 6 is an explanatory diagram illustrating a movement in a second conventional example.

[Explanation of symbols]

 2 magnetic head 3 piezoelectric element plate 4 leaf spring member 5 support member 6 support base 7 rotating drum

Claims (1)

[Scope of utility model registration request] 1. The other end of a piezoelectric element plate, one end of which is supported,
A rotary head device in which an elastic member whose one end is supported is connected to the other end, and a head is arranged at this connection portion.