JPH097141A - Magnetic head assembly equipment - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a magnetic head assembling apparatus capable of adjusting the positions of two head gaps with respect to a rotating drum while simultaneously observing the two head gaps. [Structure] First head chip 3a to objective lens 5a
Through the first return light obtained through the reference mirror 8a and the second return light obtained through the reference lens 6a, and the second head chip 3b through the objective lens 5b. Through a second interference device 100b for causing an interference between the third return light obtained through the reference mirror 8b and the fourth return light obtained through the reference lens 6b from the reference mirror 8b, and the third interference from the second head chip 3b. To obtain the return light, the first reflection means 4 for changing the optical path, the first photographing means 50a for photographing the tip portion of the first head chip via the first interference device 100a, and the second photographing means 50a. The second imaging unit 50b for imaging the tip portion of the second head chip via the interference device 100b.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head assembling apparatus for adjusting and assembling a magnetic head having a first head chip and a second head chip with respect to a rotary drum.

[0002]

2. Description of the Related Art A rotary magnetic head device is used in a video tape recorder (VTR), a digital audio tape recorder (DAT) and the like. The rotary magnetic head device includes a fixed drum and a rotary drum rotatable with respect to the fixed drum. 2 and 3 show an example of the rotary drum. The rotary drum 1 includes, for example, two magnetic heads H. This magnetic head H
Includes a head base 2 and head chips 3a and 3b attached to the head base 2. In the magnetic head, one head chip is attached to one head base (one base / one chip), and one head base 2 is attached to one head base 2 as shown in FIGS. 2 and 3.
There is a type in which two head chips 3a and 3b are attached (1 base 2 chips). In such a type in which two head chips 3a and 3b are attached to one head base 2, it is necessary to adjust and attach to the rotary drum 1 as follows. The head gap of the reference side head chip 3a is adjusted in the θ direction with respect to the rotary drum 1 and the protruding position in the R direction, and the head gap of the non-reference side head chip 3b is adjusted in the R direction. Adjustments also need to be made.

By the way, when the gap distance between the gap of the reference side head chip 3a and the gap of the non-reference side head chip 3b is 1 mm or less as in a VHS video tape recorder, one Remove the area near the center of the microscope's field of view and set the left and right head gaps to 1
An image is picked up by an image pickup device of a table and displayed on a monitor. This method is called a hollowing-out method of the field of view of one microscope.

However, when the distance between the gaps exceeds 1 mm, the resolution of the gap required for adjustment cannot be obtained by this hollowing method. Therefore, the microscope rotation method as shown in FIGS. 4 and 5 is adopted. FIG. 4 shows how the position of the reference-side head gap is adjusted while observing the head gap of the reference-side head chip 3a with the camera 200. FIG. 5 shows a case where the position of the head gap on the non-reference side is adjusted while observing the head gap of the head chip 3b on the non-reference side with the camera 200. The light from the illumination device 209a is emitted from the beam splitter 207.
It is reflected by a and is irradiated onto the head gap of the reference-side head chip 3a via the objective lens 205a. At the same time, the light from the illuminating device 209a passes through the beam splitter 207a and the reference lens 206a to the mirror 20.
8a is irradiated. Then, the return light from the reference-side head chip 3a is guided to the camera 200 through the objective lens 205a and the beam splitter 207a. Reference mirror 2
The return light from 08a passes through the reference lens 206a, is reflected by the beam splitter 207a, and is guided to the camera 200. As a result, the return light from the reference-side head chip 3a and the return light from the reference mirror 208a interfere with each other in the beam splitter 207a. This interference light can be observed by the camera 200. Next, when observing the head gap of the head chip 3b on the non-reference side, all the optical systems including the camera 200 and the objective lens 205a are tilted from the optical axis OP1 to the optical axis OP2. That is, the optical system including the camera 200 and the objective lens 205a is tilted by a predetermined angle with the center CP of the rotating drum 1 as the center. This is because the microscope rotation type assembling apparatus cannot observe the two head gaps at the same time.

Next, an assembling procedure by the conventional microscope rotating type assembling apparatus shown in FIGS. 4 and 5 will be described with reference to FIG. First, the magnetic head H shown in FIG. 4 is attached to the rotary drum 1 using the screw N and adjustment is started (step S).
1). As shown in FIG. 4, the camera 200 and the objective lens 2
The optical system including 05a is positioned corresponding to the head gap of the head chip 3a on the reference side. As shown in FIG. 3, the reference-side head gap is adjusted in position along the θ direction and is moved along the R-direction to adjust the protrusion amount of the reference-side head gap with respect to the rotary drum 1 (step S2). ). Then, as shown in FIG. 5, the optical system including the camera 200 and the objective lens 205a rotates a predetermined angle α toward the head gap side of the non-reference side head chip 3b (step S3).

The head gap of the head chip 3b on the non-reference side is the rotary drum 1 along the R direction in FIG.
Adjust the amount of protrusion to. When the magnetic head H is thus positioned with respect to the rotating drum 1, the magnetic head H is reliably fixed to the rotating drum 1 with the screw N (step S5). Again, as shown in FIG. 4, the optical system including the microscope 200 and the objective lens 205a is positioned along the optical axis OP1 (step S6). After that, if the position of the reference-side head chip 3a in the θ direction and the protrusion amount in the R direction can be confirmed (step S7), the assembly adjustment of the magnetic head ends (step S8).

[0007]

In this way, after adjusting the position of the reference-side head chip 3a, the protrusion amount of the non-reference-side head chip 3b in the R direction must be adjusted in a groping state, so to speak. Therefore, the assembly adjustment loop shown in FIG. 6 may be repeated many times, which deteriorates the productivity of assembling the magnetic head. Further, a high degree of proficiency is required for the magnetic head assembly work. Therefore, the present invention has been made to solve the above problems, and even if the head gaps of two head chips are set to be narrow,
An object of the present invention is to provide a magnetic head assembling apparatus capable of adjusting the positions of the two head gaps with respect to the rotary drum 1 while simultaneously observing the two head gaps.

[0008]

According to the invention of claim 1, the above object is to adjust and assemble a magnetic head having a first head chip and a second head chip with respect to a rotary drum. In the apparatus for assembling a magnetic head, the first head chip is irradiated with light through an objective lens, and the light is irradiated onto a reference mirror through a reference lens that is equivalent in quality to the objective lens. The first return light obtained through the objective lens and the second return light obtained from the reference mirror through the reference lens are caused to interfere with each other, and light is emitted to the second head chip. Irradiating through the objective lens, and irradiating light to the reference mirror through the reference lens which is of the same quality as this objective lens;
A second interfering device for causing interference between a third returning light obtained from the head chip through the objective lens and a fourth returning light obtained through the reference lens from the reference mirror;
In the second interference device, a reflection for changing the optical path when irradiating the second head chip with light through the objective lens and obtaining the third return light from the second head chip through the objective lens Means for imaging the tip portion of the first head chip via the first interference device.
And a second photographing means for photographing the tip portion of the second head chip via the second interference device. In the invention of claim 2, preferably, the first interference device and the second interference device are Linnik interference devices. In the invention of claim 3, preferably, the first head chip is a reference side head chip, and the second head chip is a non-reference side head chip. According to the invention of claim 4,
Preferably the reflecting means is a mirror.

[0009]

According to the invention of claim 1, the first interfering device is
Light is emitted to the first head chip through the objective lens, and light is emitted to the reference mirror through the reference lens. As a result, the first interference device causes interference between the first return light obtained from the first head chip through the objective lens and the second return light obtained from the reference mirror through the reference lens. ing. The second interfering device is
Light is emitted to the second head chip through the objective lens, and light is emitted to the reference mirror through the reference lens. As a result, the second interference device causes the third return light obtained from the second head chip through the objective lens,
It causes interference with the fourth return light obtained from the reference mirror through the reference lens.

In the second interference device, the reflecting means irradiates the second head chip with light through the objective lens and obtains the third return light from the second head chip through the objective lens. , The optical path can be changed. As a result, even if the gap between the head gap of the first head chip and the head gap of the second head chip is narrow, the objective lens of the first interference device and the objective lens of the second interference device are physically arranged. There is no fear that they will not be able to be placed due to physical interference. The first photographing means is adapted to photograph the tip portion of the first head chip via the first interference device. Similarly, the second photographing means
The tip portion of the second head chip is photographed via the second interference device.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail below with reference to the accompanying drawings. Note that the embodiments described below are
Since it is a preferred specific example of the present invention, various technically preferable limitations are attached, but the scope of the present invention is, unless otherwise stated to limit the present invention, in the following description.
It is not limited to these modes. FIG. 1 shows a preferred embodiment of the magnetic head assembling apparatus of the present invention. In FIG. 1, an embodiment of a magnetic head assembling apparatus according to the present invention is a Linnik interference apparatus 100 which is a first interference apparatus.
a and a Linnik interference device 100b that is a second interference device
And a mirror 4 which is a reflecting means, a camera 50a which is a first photographing means, a camera 50b which is a second photographing means, and the like. The magnetic head assembling apparatus is arranged corresponding to the rotary drum 1. The rotary drum 1 includes two magnetic heads H and H. The rotary drum 1 is, for example, a rotary drum of a rotary magnetic head device of a video tape recorder (VTR). The rotary drum 1 can be rotated with respect to a fixed drum by a motor, and the magnetic heads H and H can record information on the video tape or reproduce information on the video tape by a helical scan method, for example. The magnetic head H is detachably fixed to the rotary drum 1 with a screw N. Magnetic head H
Is the reference side head chip 3a and the non-reference side head chip 3
It has a total of two head chips of b. That is, the reference-side head chip 3a and the non-reference-side head chip 3b are fixed by being attached to the brass head base 2 with an adhesive or the like. The head gap of the reference side head chip 3a and the head gap of the non-reference side head chip 3b are arranged, for example, about 4 mm apart.

The position of the magnetic head H is adjusted with respect to the rotary drum 1 in the following manner. That is, the reference side head gap of the reference side head chip 3a of the magnetic head H is adjusted by the posture adjusting device in the posture direction of the rotary drum 1 along the θ direction.
Moreover, the protrusion amount of the reference-side head gap of the reference-side head chip 3a with respect to the rotating drum 1 is adjusted by the head-gap protrusion amount adjusting device along the R direction. On the other hand, the head gap of the non-reference side head chip 3b is adjusted only by the protrusion amount with respect to the rotary drum 1 by the protrusion amount adjusting device along the R direction.
That is, in adjusting the head gap on the non-reference side, only the protrusion amount adjustment in the R direction is performed, and the attitude adjustment in the θ direction is not performed.

Next, an observation system of the reference side head gap of the reference side head chip 3a will be described. The observation system of the reference-side head gap of the reference-side head chip 3a has an optical axis O
It is arranged along L1. This observation system is composed of a Linnik interference device 100a and a camera 50a. The Linnik interference device 100a includes an illumination device 9a, a beam splitter 7a, an objective lens 5a, a reference lens 6a, and a reference mirror 8a. The beam splitter 7a and the objective lens 5a are arranged along the optical axis OL1. The light L of the illumination device 9a is split into two directions by the beam splitter 7a. One light is applied to the reference side head gap side of the reference side head chip 3a via the objective lens 5a. The other light reaches the reference mirror 8a via the reference lens 6a. The objective lens 5a is a reference lens 6a.
And a lens of the same quality.

The first return light reflected by the reference side head gap of the reference side head chip 3a and its periphery passes through the beam splitter 7a through the objective lens 5a. The second return light reflected by the reference mirror 8a is reflected by the beam splitter 7a through the reference lens 6a. This allows
In the beam splitter 7a, light interference occurs between the first return light reflected by the reference head gap of the reference head chip 3a and its periphery and the second return light reflected by the reference mirror 8a. For example, the phase plane of the light reflected from the reference-side head chip 3a has an arc shape, while the reference mirror 8a
Since the phase plane of the reflected light is linear, the light is strengthened when the difference between the circular arc and the straight line in the traveling direction of the light is even multiples of half wavelength, and at the odd multiples of half wavelength. Is weakened. Since this light interference is due to the first return light of the reference-side head chip 3a, the half wavelength corresponds to 1/4 of the wavelength. That is, the head gap, which is the tip of the reference-side head chip 3a, and its peripheral portion are
It is possible to obtain the interference fringes equivalent to those displayed in contour lines at the wavelength pitch of light. The interference light thus obtained is captured by the camera 50a and displayed on the first monitor 60a. The reference-side head chip 3a is displayed on the first monitor 60a. Interference fringes 31a are displayed on the head gap 30a of the reference side head chip 3a and its peripheral portion.

Next, the observation system of the non-reference side head chip 3b will be described. What is characteristic is that the mirror 4, which is a reflecting means, is arranged in the vicinity of the non-reference side head chip 3b. The mirror 4 is preferably a surface reflection type mirror, and is arranged, for example, at a predetermined angle with respect to the optical axis OL1. As described above, the surface reflection type mirror 4 is used in order to eliminate aberration when the focused light is reflected by the mirror. In other words, they are arranged at a predetermined angle β with respect to the optical axis OL2. A camera 50b and a Linnik interference device 100b are disposed near the mirror 4 along the optical axis OL2. The optical axis OL2 is preferably orthogonal to the optical axis OL1. The observation system of the reference side head gap of the non-reference side head chip 3b is arranged along the optical axis OL2. This observation system includes a Linnik interference device 100b and a camera 50b. Linnik interference device 100
Reference symbol b includes an illumination device 9b, a beam splitter 7b, an objective lens 5b, a reference lens 6b, and a reference mirror 8b.
The beam splitter 7b and the objective lens 5b have an optical axis OL2.
It is arranged along with. The light L of the illumination device 9b is split into two directions by the beam splitter 7b. One of the light beams passes through the objective lens 5b and the non-reference side head chip 3b.
The reference side head gap side is irradiated. The other light reaches the reference mirror 8b via the reference lens 6b. The objective lens 5b is a lens of the same quality as the reference lens 6b.

The third return light reflected at the reference side head gap of the non-reference side head chip 3b and its periphery passes through the beam splitter 7b through the objective lens 5b. The fourth return light reflected by the reference mirror 8b is reflected by the beam splitter 7b through the reference lens 6b. As a result, the beam splitter 7b moves to the reference side head chip 3b.
Light interference occurs between the third return light reflected by the reference side head gap and the periphery thereof and the fourth return light reflected by the reference mirror 8b. For example, the phase plane of the light reflected from the reference-side head chip 3b has an arc shape, whereas the reference mirror 8
Since the phase plane of the light reflected from b is linear,
The difference between the circular arc and the straight line superposed in the traveling direction of the light is strengthened at an even multiple of a half wavelength and weakened at an odd multiple of a half wavelength. Since this light interference is due to the third return light of the reference side head chip 3b, the half wavelength corresponds to ¼ of the wavelength. That is, it is possible to obtain an interference fringe equivalent to that in which the head gap, which is the tip of the reference-side head chip 3b, and the peripheral portion thereof are displayed in contour lines at the wavelength pitch of light. The interference light thus obtained is captured by the camera 50b and displayed on the second monitor 60b. The non-reference side head chip 3b is displayed on the second monitor 60b. The interference fringes 3 are formed in the head gap 30b of the non-reference side head chip 3b and the peripheral portion thereof.
1b is displayed.

Next, an example of a method of assembling and adjusting a magnetic head by the above-described magnetic head assembling apparatus will be described. First, the rotary drum 1 of FIG. 1 is held in a state where one magnetic head H is tilted at a predetermined angle x with respect to the optical axis OL1. In this state, the head gap 30a of the reference side head chip 3a is
And its vicinity are at positions where the light L of the illumination device 9a can irradiate. Moreover, the head gap 30b of the head chip 3b on the non-reference side is also a position where the light L of the illumination device 9b of the Linnik interference device 100b can be emitted.

Thus, the Linnik interference device 100a,
Since two 100b are used, the Linnik interference device 10
In order to avoid the possibility that the objective lens 5a of 0a interferes with the objective lens 5b of the other Linnik interference device 100b in a positional manner and cannot be set, the mirror 4 exerts its function. That is, the mirror 4 is the Linnik interference device 100.
The light L from b is bent at a predetermined angle (for example, an angle larger than 90 °) and irradiated on the head gap side of the non-reference side head chip 3b, and the mirror 4 reflects the third light reflected from the head gap and its peripheral portion. It is possible to return the return light of the above to the Linnik interference device 100b side via the mirror 4. By disposing the mirror 4 corresponding to the non-reference side head chip 3b side, even if the distance between the two head gaps is as small as about 4 mm, the objective lens 5a,
b will not interfere with each other physically, and
The two head gaps are along the optical axes OL1 and OL2,
Can be observed at the same time. Moreover, the head gap of the head chip 3a on the reference side is directly observed by the camera 50a for the following reason. In other words, since high accuracy is required for the attitude adjustment of the head gap 30a of the reference side head chip 3a in the θ direction, the reference side head gap 30a is observed directly by the camera 50a, that is, without being reflected by a mirror or the like. Is desirable.

On the other hand, the non-reference side head chip 3b
In the adjustment of the head gap 30b, the adjustment of the protrusion amount along the R direction is only necessary, and the attitude adjustment in the θ direction is not performed. Therefore, the mirror 4 is attached to the non-reference side head gap 30b.
By using it for the observation of the two head gaps 3
0a and 30b can be observed simultaneously and with high accuracy.

In the embodiment of the present invention, since the two head gaps 30a and 30b can be adjusted while observing at the same time, the magnetic head positioning adjustment work is easy. Further, since the rotation time of the microscope, which is required in the conventional microscope rotation method, can be omitted, the working time can be shortened. Moreover, in the embodiment of the present invention, since the microscope does not rotate and is fixed, the observation accuracy is improved. Since the position of the head gap of the reference side head chip can be directly observed by the camera 50a, highly accurate adjustment is performed. In the embodiment of the present invention, two head gaps can be observed at the same time even when the gap between the head gaps is narrow, for example, wider than about 1 mm and narrower than the diameter of the objective lens. The Linnik interference devices 100a and 100b described above are ultra-long working distance type microscopes, and these are interference microscopes. The present invention is not limited to the above embodiment. Although the reflecting mirror 4 in FIG. 1 is used as the reflecting means, the reflecting mirror 4 is not limited to this and may be a prism or other optical parts. The rotary drum and its magnetic head described above are
Although it is applied to video tape recorders,
The present invention is not limited to this, and the present invention can be applied to magnetic heads used in models in other areas such as digital audio tape recorders and data streamers.

[0021]

As described above, the positions of the two head gaps can be adjusted while observing the two head gaps simultaneously, even if the gaps between the head gaps of the two head chips are set to be narrow. .

[Brief description of drawings]

FIG. 1 is a view showing a preferred embodiment of a magnetic head assembling apparatus of the present invention.

FIG. 2 is a side view showing an example of a rotary drum.

FIG. 3 is a bottom view of the rotary drum.

FIG. 4 is a diagram showing a position at the time of adjusting a reference side head gap in a conventional magnetic head assembling apparatus.

FIG. 5 is a view showing a position at the time of adjusting a non-reference side head chip in the conventional magnetic head assembling apparatus of FIG. 4;

FIG. 6 is a diagram showing a procedure for assembling a conventional magnetic head chip.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating drum 2 head base 3a reference side head chip 3b non-reference side head chip 30a reference side head gap 30b non-reference side head gap 50a camera (first photographing means) 50b camera (second photographing means) 100a Linnik interference device (First interference device) 100b Linnik interference device (second interference device) H Magnetic head

Claims (4)

[Claims] 1. A magnetic head assembling apparatus for adjusting and assembling a magnetic head comprising a first head chip and a second head chip with respect to a rotating drum, wherein a light is emitted to the first head chip. The first return light obtained through the objective lens from the first head chip through the objective lens, and the reference mirror having the same quality as the objective lens, and the reference mirror, and the reference light from the reference mirror. A first interferometer for causing interference with a second return light obtained through the second head chip, and irradiating the second head chip with light through the objective lens, and the light for reference which is of the same quality as the objective lens. Interference between the third return light emitted from the second head chip through the objective lens and the fourth return light obtained through the reference lens by irradiating the reference mirror through the lens. A second interfering device for raising the light, and in the second interfering device, irradiates the second head chip with light through the objective lens and obtains the third return light from the second head chip through the objective lens. At this time, a reflecting means for changing the optical path, a first photographing means for photographing the tip portion of the first head chip via the first interference device, and a first photographing means for photographing the tip part of the first head chip via the second interference device. And a second photographing means for photographing the tip portion of the head chip of No. 2, and a magnetic head assembling apparatus. 2. The magnetic head assembling apparatus according to claim 1, wherein the first interference device and the second interference device are Linnik interference devices. 3. The magnetic head assembling apparatus according to claim 1, wherein the first head chip is a reference side head chip and the second head chip is a non-reference side head chip. 4. The magnetic head assembling apparatus according to claim 1, wherein the reflecting means is a mirror.