JP2824181B2 - Rotating magnetic head device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a VTR (Video
Used in magnetic recording / reproducing devices such as Tape Recorder, etc., and a movable magnetic head using a bimorph on a head base portion is attached to the lower end surface of a rotating drum.
The present invention relates to a rotating magnetic head device having a drum structure including a rotating drum and a fixed drum, and more particularly to a device provided with electrodes for detecting and controlling the position of the movable magnetic head on a side of the fixed drum facing a head base.

[0002]

2. Description of the Related Art FIGS. 4, 5, 6 and 7 show conventional examples. FIG. 4 is a half sectional view showing the entire drum, FIG. 5 is a perspective view of a movable magnetic head using a bimorph as a head base incorporated therein, and FIG. 6 is a view showing the movable magnetic head disposed on a rotating drum. FIG. 7 is a perspective view showing the appearance
FIG. 3 is a schematic explanatory view showing a positional relationship between a normal magnetic head and a movable magnetic head in a height direction.

[0003] In Fig. 4, reference numeral 1 denotes a fixed drum, and bearings 2 and 3 are incorporated in upper and lower portions, respectively.

Reference numeral 4 denotes a shaft serving as a rotating shaft. A disk 6 for supporting the rotating drum 5 is fixed by shrink fitting or the like. The shaft assembly is inserted into upper and lower bearings 2 and 3, and a collar 7 is provided. Thus, the required pressure is applied to the bearings 2 and 3 so as to be fixed.

[0005] Reference numeral 8 denotes a rotary transformer on the fixed drum 1 side. In this example, a cylindrical rotary transformer is used.

Reference numeral 9 denotes a rotary drum-side rotary transformer, which is provided on the rotary drum 5.

Reference numeral 10 denotes a plurality of magnetic heads mounted on the rotating drum 5, and a plurality of magnetic heads 11 include a movable magnetic head using a bimorph as a head base. In consideration of versatility on a rotating drum, the movable magnetic head 11 is the same as the head base of another magnetic head in which a bimorph is not used for the head base (hereinafter referred to as a normal magnetic head).

Reference numeral 12 denotes a pressing plate for fixing the head base of the bimorph to the rotary drum 5 and is fixed by screws 13.

Reference numeral 14 denotes an electrode of a sensor for detecting and controlling the height position of the movable magnetic head 11.
And is opposed to one surface of a bimorph head base with a gap shown in FIG. Although not shown in the figure, the electrodes are connected to an appropriate circuit.

The reason why the electrode 14 is made to face the head base and the height of the head chip attached to the tip of the head base is detected and controlled is to use the movable magnetic head for recording. If it is used exclusively for reproduction as in the past, it can be controlled by the reproduction output, etc., but at the time of recording, it is necessary to reduce the mechanical step between the head pair to 0, so a sensor etc. for detecting this step is necessary. It is becoming. The detection sensor has a bimorph itself as an electrode by applying silver or the like to one side of the bimorph, another electrode is made to face this, and a potential is applied to the two electrodes facing each other, so that the electrostatic generated between the electrodes is generated. The position of the head is controlled by detecting the capacitance with an appropriate circuit.

FIG. 5 is a perspective view showing the movable magnetic head 11 taken out for easy understanding. In FIG. 5, reference numeral 15 denotes a bimorph head base, and a head chip 16 is fixed to the tip by a method such as adhesion. The electrodes 14 of the sensor are arranged on the head base 15 so as to face each other with a small gap as shown in FIG. Reference numeral 17 denotes a pressing plate for the head base 15, through which the head base 15 is fixed to the rotating drum by screws.

The electrode 14 determines the height displacement of the head chip 16 at the tip of the head base from the amount of displacement of the gap between the electrode 14 and the head base 15 when the electrode 14 is bent around the portion where the head base 15 of the bimorph is located. Because of the conversion, a position as close to the head chip 16 as possible enables more accurate position detection and control.

FIG. 6 is a perspective view for explaining the structure of the rotary drum and the movable magnetic head, and shows the rotary drum alone viewed from the back side for easy understanding. In FIG. 6, the upper side in the figure corresponds to the lower end face of the rotating drum 5, and the arrows in the figure indicate the rotating direction after assembly with the fixed drum. The ordinary magnetic head 10 is fixed to the rotating drum 5 by screws 18 and the movable magnetic head 1
Numeral 1 is fixed to the rotating drum 5 by screws 13, and an electrode 14 of a sensor is opposed to a head base 15 of the movable magnetic head 11.

FIG. 7 is a diagram showing a positional relationship between the normal magnetic head 10 and the movable magnetic head 11 in the height direction. The normal magnetic head 10 and the movable magnetic head 11 are on the same surface on the rotating drum. However, as shown in the figure, the head base of the movable magnetic head base 11 made of bimorph is thinner than the head base of the normal magnetic head 10 as shown in FIG.
0 to the dimension a of the movable magnetic head 11 to the electrode 14 facing the head base from the dimension b to the top surface of the head base.
Becomes smaller.

[0015]

When the movable magnetic head 11 of the bimorph is formed in the same shape as the ordinary magnetic head 10, the thickness of the head base of the movable magnetic head 11 becomes thin due to its characteristics, and therefore, the fixed drum opposing the head base. The sensor electrode 14 on one side protrudes toward the head base of the movable magnetic head 11. Therefore, when the rotary drum 5 rotates as it is, there is a problem that the electrode 14 of the sensor attached to the fixed drum 1 hits a part of the rotary drum 5 other than the movable magnetic head 11. This problem can be solved by increasing the thickness of the head base,
The thickness of the normal magnetic head 1
It cannot be as thick as the 0 head base.

An object of the present invention is to solve the above-mentioned problems without increasing the thickness of the head base of the movable magnetic head 11, and to provide a rotary magnetic head device which has solved the above-mentioned problems. .

[0017]

A rotary magnetic head device according to the present invention has a drum structure comprising a rotary drum and a fixed drum, wherein a movable magnetic head using a bimorph for a head base portion is mounted on the lower end surface of the rotary drum. A rotating magnetic head device, wherein a position detection and control electrode of the movable magnetic head is provided on a side of the fixed drum facing a head base, wherein an electrode facing the electrode is also provided on the head base side. In addition, the dimension of the electrode in the fixed drum direction is higher than other components provided on the rotating drum.

[0018]

According to the rotary magnetic head device of the present invention, the electrode of the sensor on the fixed drum side can escape from other parts of the rotary drum side in height, so that the sensor electrode of the fixed drum rotates when the rotary drum rotates. It is possible to prevent collision with parts on the drum side.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the rotary magnetic head device of the present invention will be described below with reference to FIGS.

In the following description, the same parts as in the conventional example will not be described.

FIG. 1 is a perspective view of a movable magnetic head using a bimorph as a head base incorporated in a rotary magnetic head device according to the present invention, and FIG. 2 is a diagram illustrating the movable magnetic head disposed on a rotating drum. FIG. 3 is a schematic explanatory view showing a positional relationship between a normal magnetic head and a movable magnetic head in the height direction in the rotary magnetic head device of the present invention.

In FIG. 1, reference numeral 20 denotes a movable magnetic head having a head base 21 made of a bimorph, and reference numeral 22 denotes a pressing plate for fixing the movable magnetic head 20 to a rotating drum. 23 is a head base 21 of the movable magnetic head 20
A head chip 24 attached to the tip of the head is an electrode fixed to the head base 21. An electrode 25 attached to a fixed drum is installed opposite to the electrode 24 with the same gap as that of the related art, and a sensor is mounted. Make up. Electrode 24 attached to movable magnetic head 20
The height of the head chip 23 at the tip of the head base is determined from the amount of displacement of the gap between the electrode 24 and the electrode 25 when the electrode 25 attached to the side of the fixed drum bends about the portion where the head base 21 of the bimorph is located as a fulcrum. , The position of the head chip 23 is detected and controlled, so that a position as close to the head chip 23 as possible can perform position detection and control with higher accuracy.

FIG. 2 shows the relationship between the ordinary magnetic head 27 and the movable magnetic head 20 on the rotating drum 26, and the arrows in the figure indicate the rotating direction of the rotating drum 26. Normal magnetic head 2
7 is fixed to the rotating drum 26 by a screw 28, and the movable magnetic head 20 is fixed to the rotating drum 26 by a screw 29.
It is fixed to.

FIG. 3 is a schematic explanatory view showing the positional relationship in the height direction between the ordinary magnetic head 27 and the movable magnetic head 20 in the rotary magnetic head device of the present invention. The movable magnetic head having a bimorph head base 21 is shown. As described above, the electrode 24 of the sensor is fixed on the electrode 20, and there is a gap between the electrode 24 and the electrode 2 of the fixed drum.
5 are installed facing each other. At this time, the dimension a, which is the sum of the height and the gap size of the electrode 24 on the bimorph head base 21, that is, the dimension a from the mounting surface of the head base 21 to the electrode 24 of the fixed drum is set to the normal magnetic head 2.
7 is set higher than the dimension b up to the upper surface of the head base, that is, the highest dimension. Therefore, it is possible to prevent components on the normal magnetic head 27 from hitting the electrode 25 of the fixed drum.

[0025]

According to the rotary magnetic head device of the present invention, the electrode of the sensor on the fixed drum side can be made to escape from other parts on the rotary drum side in height, and thus the rotary drum head has the above-described configuration. During rotation, it is possible to prevent the electrode of the stationary drum from hitting the component on the rotating drum. Therefore, the movable magnetic head can be mounted without changing the shape of other parts, which brings about a cost advantage of the entire drum and versatility of equipment in an assembling process.

[Brief description of the drawings]

FIG. 1 is a perspective view of a movable magnetic head using a bimorph as a head base incorporated in a rotary magnetic head device according to the present invention.

FIG. 2 is a perspective view showing a state in which a movable magnetic head is arranged on a rotating drum in the rotating magnetic head device of the present invention.

FIG. 3 is a schematic explanatory view showing a positional relationship in a height direction between a normal magnetic head and a movable magnetic head in a rotary magnetic head device according to the present invention.

FIG. 4 is a half sectional view showing the entire drum of the conventional rotary magnetic head device.

FIG. 5 is a perspective view of a movable magnetic head using a bimorph as a head base incorporated in a drum of a conventional rotary magnetic head device.

FIG. 6 is a perspective view showing a state in which a movable magnetic head is arranged on a rotating drum in a conventional rotating magnetic head device.

FIG. 7 is a schematic explanatory view showing a positional relationship in a height direction between a normal magnetic head and a movable magnetic head in a conventional rotary magnetic head device.

[Explanation of symbols]

 Reference Signs List 1 rotating drum 5 fixed drum 20 movable magnetic head 21 head base 24 electrode 25 electrode 27 normal magnetic head (an example of other parts)

Claims (1)

(57) [Claims] A movable magnetic head using a bimorph for a head base portion is attached to a lower end surface of a rotating drum.
A rotary magnetic head device having a drum structure including a rotary drum and a fixed drum, wherein a position detection and control electrode of the movable magnetic head is provided on a side of the fixed drum facing a head base. A rotating magnetic head device, wherein an electrode facing the electrode is provided also on the base side, and the dimension of the electrode in the fixed drum direction is higher than other components provided on the rotating drum.