JPS5892901A - Angle detector - Google Patents

Abstract

PURPOSE:To correct an error in position matching with simplicity in construction and good accuracy by a method wherein a supporting member is provided with a circular hole for mounting and positioning purposes, while the circular hole is provided with the center conforming to the geometrical center of the detector in a magnetic detection element. CONSTITUTION:A magnetic detection element 2A mounted on a supporting member 3 is fixed to a projection 4-1 on a pedestral 4 via a circular hole 3-1 made in the supporting member 3, a gap being made between the element and a magnetic recording medium. The circular hole 3-1 is made in the supporting member 3 beforehand and the magnetic detection element 2A is mounted and fixed on the supporting member 3 in such a manner that the center of the circular hole 3-1 conforms to the geometrical center relating to a detecting portion 2A-1a of an element pattern 2A-1. The substrate of the magnetic detection element 2A is transparent glass and that matching work can readily be made under a microscope with a reference line. By providing the projection 4-1 fitting into the circular hole 3-1 on the pedestral 4 for installing the whole assembly relating to the magnetic detection element 2A mounted on the supporting member 3, the assembly is turned in the direction of P or Q so as to correct an error in position matching and fixed in position, using an adhesive agent.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an angle detector, and particularly to a mounting structure of a magnetic detection element suitable for a type in which a ferromagnetic metal thin film magnetoresistive element and a magnetic recording medium are opposed to each other for detection. This invention relates to an angle detector aimed at improving the angle.

Conventionally, optical rotary encoders have been widely used as angle detectors, but they have become cheaper.

Various magnetic detection types have been developed which are advantageous in terms of miniaturization and high performance.

For example, those described in Japanese Patent Application Laid-open No. 54-115257, "Nikkei Electronics" No. 1981-6-22,
There is something described in the NE report section on page 88.

According to the content of these publications, the magnetic recording pinch is 6
It is approximately 0 to 350 μm, and since a plurality of magnetic detecting elements are arranged therein, the arrangement pinch of the magnetic detecting elements is required to be very fine, 15 to 90 μm.

Fortunately, magnetic detection elements are the key to this.

Because it can be manufactured by vapor deposition and etching of a ferromagnetic metal thin film,
Coupled with the recent development of photolithography technology, there are no production technology problems.

By the way, one of the important problems that must be solved here is the magnetic detection element that has been miniaturized in this way and the magnetization pattern (which is invisible to the human eye) recorded on the recording medium that is the object to be detected. The key to commercialization is how to achieve accurate alignment with the product, and how to create a mounting structure that allows for easy alignment without taking much time. You can say that you are holding it.

This is because the output signal of the magnetic detection element is at most 25
This is because the output signal drop due to positioning errors must be suppressed as much as possible since it is only about .about.somv.

Under these circumstances, in order to align the invisible magnetization with the turning partner on the order of 1 micron, it is necessary to have a certain degree of freedom in the direction of movement, but it is necessary to have too much freedom. Therefore, the alignment work takes time, resulting in a large cost increase.

In view of the above-mentioned problems, the present invention provides an angle detector equipped with a mounting structure that allows the element pattern of a magnetic detection element to be precisely aligned with the magnetization pattern of a recording medium that is an object to be detected. That is the purpose.

The gist of the present invention is that the output signal (detection ability) of the magnetic sensing element based on the detection principle described above is determined by the gap between the magnetic recording medium and the magnetic sensing element and the magnetization pattern recorded on the magnetic recording medium. It was confirmed that the error in the relative position of the magnetic detection element to the element pattern is the most affected, and in particular,
This makes it possible to easily align the patterns.

The present invention is characterized by an angle detection system that includes a magnetic recording medium on which magnetic recording is performed, and a magnetic detection element that is placed opposite to the magnetic recording medium and reads out and outputs a signal recorded on the magnetic recording medium. In the device, the magnetic detection element is mounted on a support member that is to be attached to the mounting body, and the support member has a center that coincides with the geometric center of the detection part of the magnetic detection element. have,
This angle detector is provided with a circular hole for alignment as well as for mounting.

Next, before describing an embodiment according to the present invention, the configuration of a conventional device and its alignment error will be explained with reference to FIGS. 1 to 3.

Therefore, FIG. 1 is a perspective view of a conventional angle detector, and FIG. 2 is a perspective view showing the arrangement of a magnetic recording medium and a magnetic detection element.
FIG. 3 is a partial enlarged layout diagram when there is no positioning error, and FIG. 3 is a partially enlarged layout diagram when there is a positioning error.

That is, the magnetic recording medium 1 and the magnetic detection element 2 are
As shown in the figure, the magnetic detection element 2 is arranged with a gap t, and the magnetic detection element 2 is fixed to the other mounting body without using any supporting member, and the magnetic detection element 2 is arranged with a gap t.
is an important element that influences the output (detection ability) of the magnetic detection element 2, and is adjusted to the optimum value during assembly.

FIG. 2 shows the magnetization pattern of the magnetic recording medium 1 and the element pattern 2-1 of the magnetic detection element 2.

This indicates the state where the alignment error is eliminated.
Figure 3 shows a state where there is an alignment error α, and in the state shown in Figure 3, the output of the magnetic sensing element 2 further decreases, so that it is no longer normal. It becomes impossible to function.

Next, FIG. 4 is a plan view of a magnetic detection element mounted on a support member according to an embodiment of the present invention, and FIG. 5 is a partial sectional view of the magnetic detection element mounted on a pedestal. It is.

In the figure, 2 people are magnetic detection elements, 2A-1 is element pattern %
2A-18 is a U-shaped detection part, 2A-1b is a terminal part, 3 is a support member, 3-1 is a circular hole, 4 is a pedestal for the attachment body, and 4-1 is a protrusion. be.

The support member 3 can be made of metal or synthetic resin, but is preferably made of a non-magnetic material.

That is, the structure is such that two magnetic detection elements are mounted on a support member 3. That is, the support member 3 has a circular hole 3-1 for positioning and also for mounting.
The center of the element pattern is
Detecting units 2A-1a and 2A-1a arranged on the left and right sides of 1
The positions are equidistant n, n (on the Y-axis in the figure) from the outside of A-1#, and equidistant m, m (on the X-axis in the figure) above and below the detection unit 2A-1a.

That is, it is mounted and fixed so as to coincide with the geometric center of the detection section 2A-1a.

Therefore, in the angle detector according to the present embodiment, the magnetic detection element 2A mounted on the support member 3 is separated from the magnetic recording medium 1 shown in FIG. -1
Accordingly, it is attached and fixed to the protrusion 4-1 of the pedestal 4.

As mentioned above, the two magnetic detection elements are mounted on the support member 3, but in this case, the support member 3 has the elements at positions determined according to the size and external shape of the mounted element putter y2A-1. A circular hole 3-1 is provided in advance, and when mounting two magnetic detection elements on the support member 3, the circular hole 3-1 is provided in advance.
-1 center and.

The geometric center of the detection unit 2A-18 of the element pattern 2-1 is made to coincide with the geometric center and fixed.

Since the substrates of the two magnetic detection elements are made of transparent glass, this can be easily done by using a microscope with a baseline.

If this is done, for example, the pedestal 4 on which the whole of the magnetic detection elements mounted on the support member 3 for two people is attached will be provided with a protrusion 4-1 that extends into the circular hole 3-1. This allows the entire position to be determined, and by rotating it around the protrusion 4-1 in the P and Q directions shown in Figure 1, the positioning error can be corrected and fixed with adhesive or the like. It is.

In actual work, the magnetization pattern is invisible, so the output of the magnetic detection element must be observed and fixed at its maximum point. The degree of freedom of adjustment is 1, and adjustment can be performed extremely easily.

As described above, according to this embodiment, unlike the conventional method, first, the magnetic detection element is fixed in opposition to the magnetic recording medium via the support member, and inseparable from the attachment of the support member, The positioning error can be easily corrected, and unique effects can be obtained for a unique item called an angle detector.

Note that in the above embodiment, the circular hole is provided in advance, but this is because the magnetic detection element is first mounted on the support member, and the hole has a center that coincides with the geometric center of the detection part. This does not preclude the provision of circular holes.

Taking all of the above into account, the present invention provides an angle detector with the simplest configuration and with the most accurate alignment error correction. This can be said to be an invention that can be expected to have excellent effects specific to articles.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a conventional angle detector showing the arrangement of a magnetic recording medium and a magnetic detection element, FIG. 2 is a partially enlarged layout diagram when there is no alignment error, and FIG. FIG. 4 is a partially enlarged layout diagram when there is an alignment error; FIG. 4 is a plan view of a magnetic detection element mounted on a support member according to an embodiment of the present invention; and FIG. 5 is a diagram showing the magnetic detection element. FIG. 1... Magnetic recording medium, 2A... Magnetic detection element, 2A
-1... Element pattern, 2A-1a... Detection section, 2
A-1b...Terminal part, 3...Supporting member, 3-1...
・Circular hole. 4...Pedestal, 4-1...Protrusion. Agent: Patent attorney Kosaku Fukuda (and one other person)

Claims (1)

[Claims] 1. A magnetic recording medium that is magnetically recorded and a magnetic detection element that is placed opposite to the magnetic recording medium and reads out and outputs a signal recorded on the magnetic recording medium. In the angle detector, the magnetic detection element is mounted on a support member that is attached to a mounting body. and the support member is provided with a circular hole for positioning and for mounting, the center of which coincides with the geometric center of the detection part of the magnetic detection element. vessel. 2. In the item described in claim 1. The geometric center of the detection part in the magnetic detection element is An angle detector located at an equal distance from the outside of each of the detection sections arranged on the left and right sides of the element pattern, and at an equal distance above and below the detection sections.