JPS58215508A - Detector - Google Patents

Abstract

PURPOSE:To obtain a detector which is small in size or thickness and has large outputs with reference to a detector which detects the speed or the extent of movement of an object to be measured with magneto-electric transducers by using the object which is arranged with materials having different magnetic permeability at a predetermined pitch. CONSTITUTION:Magneto-electric transducers 8, 9 are so installed relatively at a certain size that when the transducer 8 is at the position facing a base member 6 or a fitting member 7, the transducer 9 faces the member 7 or the member 6. Therefore, when, for example, the transducer 8 faces the member 6 and the transducer 9 faces the member 7, the magnetic fluxes to be applied from a permanent magnet on the transducers 8, 9 differ respectively on account of a difference in the magnetic permeability that the member 6 and the member 7 possess. As a result, the electric resistance values of the transducers 8, 9 change individually. Outputs are drawn out differentially from the transducers 8, 9 in such a way, whereby the extent of the movement, etc. of an object 5 to be measured are detected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a detector that detects the speed or amount of movement of an object to be measured using a magnetoelectric transducer, and particularly relates to an improvement of the object to be measured.

A conventional detector of this type will be explained with reference to FIGS. 1 and 2.

The conventional detector shown in FIG. 1 is composed of an object to be measured 1 having a concave portion 1a and a convex portion 1b, a magnetoelectric conversion element 2.6, and a permanent magnet 4.

In this detector, the magnetic flux that reaches the object to be measured 1 from the permanent magnet 4 via the magnetoelectric transducer 2.degree.
The amount of change in electrical resistance of the magnetoelectric transducer 2.3 is differentially extracted and detected by utilizing the change in resistance due to the difference in level between the magnetoelectric transducer 2.3 and the convex portion 1b.

In this way, by utilizing the fact that the magnetic flux changes due to the difference in level between the concave portion 1as and the convex m1b provided in the object to be measured 1, the magnetoelectric conversion element 2
．． In the detector for detecting the amount of change in electrical resistance in No. 6, if the step between the concave portion 1a and the convex portion 1b is small, the output will be small, and in order to increase the output, this step must be increased. .

In order to widen the level difference between the concave portion 1a and the convex portion 1b,
Since the object to be measured 1 had to be very thick, it was considered difficult to provide a small or thin detector.

In addition, if the thickness is thin and the height difference is small, the magnetoelectric transducer and the object to be measured must be placed very close to each other in order to obtain an output.
There is also a risk of damage to the magnetoelectric transducer due to contact.

The conventional detector shown in FIG. 2 consists of a plate-shaped object to be measured 11 which is magnetized at equal pitches than the object to be measured 1 having irregularities shown in FIG.
It has been changed to .

Such an object to be measured 1' is very expensive, and it is difficult to accurately determine the pitch.

Therefore, if the pitch of the magnetic poles is made too small, manufacturing becomes difficult and extremely expensive, which is disadvantageous, and the desired coercive force cannot be secured unless the measured object 11 is made thicker to some extent. It also had the disadvantage of not being able to.

The present invention eliminates the drawbacks of the conventional example by using a measured object in which materials with different magnetic permeability are arranged at a predetermined pitch, and provides a detector that is small or thin and has a large output. The purpose is to

The present invention will be described in detail below based on the drawings.

FIG. 3 is a diagram showing an embodiment of the present invention.

Reference numeral 5 denotes an object to be measured, which includes a base member 6 having recesses 6a provided at a predetermined pitch, and a fitting member 7 fitted into the recesses 6a and having a magnetic permeability different from that of the pace member 6.

8.9 is a magnetoelectric conversion element such as a magnetoresistive element, a Hall element, a magnet diode, etc., and 10 is a permanent magnet.

The magnetic flux from the permanent magnet 10 reaches the object to be measured 5 via the magnetoelectric conversion element 8.9.

The magnetoelectric transducers 8 and 9 are arranged such that the magnetoelectric transducer 8 is connected to the pace member 6.
Alternatively, when in a position facing the insertion member 7, the magnetoelectric transducer 9 is installed with a certain dimension relatively so as to face the insertion member 7 or the pace member 6. For this reason, for example, when the magnetoelectric transducer 8 faces the base member 6 and the magnetoelectric transducer 9 faces the fitting member 7, the material of the pace member B and the material of the fitting member 7 may have different magnetic permeabilities. The magnetic fluxes applied from the permanent magnets to the magnetoelectric transducers 8 and 9 are different, and as a result, the magnetoelectric transducers 8 and 9
The electrical resistance value of varies individually.

By utilizing the fact that the resistance values of the magnetoelectric transducers 8 and 9 change in this way, it is possible to extract the output differentially from the magnetoelectric transducers 8 and 9 to detect the amount of movement of the object to be measured 5, etc. .

Next, an example of the combination of the material of the pace member B and the material of the fitting member 7 is shown in the front work.

Table I As long as the fitting member 7 has a higher magnetic permeability than the base member 6, combinations other than those shown in the above-mentioned surface work may be used. Materials with high magnetic permeability may also be used. The fitting member 7 is fixed to the recess 6a of the base member 6 by appropriate means such as adhesion or welding. ' Fig. 4 shows another embodiment of the object to be measured 5 shown in Fig. 3, and 11 is a plate-shaped pace member! 0. ．． Reference numeral 12 denotes a ladder-shaped member having a string 12a provided at a predetermined pitch and having a higher magnetic permeability than the base member 11.

Next, the manufacturing process of the object to be measured 5 of this embodiment will be explained using the combination of Ni and steel shown in Table 2 as an example.

(1) A photosensitive resin is applied to the surface of the substrate of the ladder-like member 12 made of Ni.

(2) On a nickel substrate coated with a photosensitive resin, a photographic original plate with a ladder-like transparent part formed by alternating light-shielding parts and transparent parts at a predetermined pitch is placed on top of the nickel substrate, and then exposed to light. .

As a result, the photosensitive resin corresponding to the light-blocking areas of the photographic original plate does not change, but the photosensitive resin corresponding to the light-transmitting areas undergoes a photochemical reaction.

(3) The exposed nickel substrate is developed with a developer.

The photosensitive resin undergoing a photochemical reaction forms a film by developing, and the other portions of the surface of the nickel substrate are exposed.

(4) Perform etching on the nickel substrate after development.

Only the exposed surface of the nickel substrate is corroded and comes off, leaving the nickel substrate shaped like a ladder.

(5) A nickel substrate (ladder-like member 12) formed in a ladder shape is fixed to a base member 11 made of a steel plate.

Although the object to be measured 5 of this example is formed through such a process, there is another similar method of forming the ladder-like member 12 completely separately from the base member 11 and fixing it to the base member 11. There is also a method of forming a ladder-like member by a method.

In addition to the method of separately forming and fixing the base member 11
It is also possible to form the object to be measured 5 by processing a steel plate on which Ni or the like is fixed by vapor deposition or sputtering on the upper surface of the plate. Alternatively, a ladder-like structure formed by connecting a plurality of rod-shaped members having high magnetic permeability may be fixed to the surface of the base member 110.

FIG. 6 is a diagram showing another embodiment of the object to be measured 5 shown in FIG. 3.

13 is a base member, and 14 is a fixed member fixed to the upper surface of the base member 16 at a predetermined pitch and having a higher magnetic permeability than the base member 16.

This fixing member 14 is made by fixing a material with high magnetic permeability to the bare surface of the base member 13 by vapor deposition or sputtering, and then forming a photosensitive resin film in the same way as the ladder-like member 12 shown in FIG. 4, followed by etching. It is formed by applying

According to the present invention described above, since changes in magnetic flux caused by differences in magnetic permeability are detected, a large output can be obtained. As a result, high output can be obtained even if the object to be measured is made thinner, and the detector itself can be made smaller or thinner.

Furthermore, since the output is high, a large air gap can be created between the magnetoelectric transducer and the object to be measured, eliminating damage caused by contact between the two.

In addition, since slits can be formed with a predetermined pitch by etching, etc., the pitch can be made finely and accurately. No need to worry seriously.

Furthermore, any material can be used as the object to be measured, as long as it is not specially magnetized like the conventional object shown in Figure 2 and has a different magnetic permeability. Since it can be used, the price can be kept low.

As described above, the present invention provides a thin and compact detector capable of obtaining high output.

[Brief explanation of the drawing]

1 and 2 are views showing a conventional detector, FIG. 3 is a view showing an embodiment of the present invention, and FIG. 4 is a center view showing another embodiment of the object to be measured shown in FIG. 3. 5 is a top view of the object to be measured shown in FIG. 4, and FIG. 6 is a diagram showing another embodiment of the object to be measured shown in FIG. 3. 1.1', 5...-object to be measured, 2, 3, 8.9... magnetoelectric exchange element, 4, 10. ...Permanent magnet, 6,11.13
- Base member's 6a... Recessed portion, 7... Fitting member, 12... Ladder-like member, 12a... Slit, 14... Fixing member. Patent applicant: Kawaguchiko Precision Co., Ltd. No. 1
mouth! Figure 3 Figure 6 Figure '13 Figure 2 Figure 4 Figure 5

Claims (4)

[Claims] (1) In a detector in which a magneto-electric transducer and a measured object are arranged facing each other at a distance, and output is differentially output from the magneto-electric transducer, the measured objects have different magnetic permeabilities. 1. A detector comprising a plurality of members having: (2) Claim 1, wherein the member is a base member having a plurality of recesses arranged at a predetermined pitch, and a fitting member fitted into the recesses of the base member. Detector as described. (3) The member is a ladder-like member having a plate-like base member and slits fixed to the base member and arranged at a predetermined pitch. detector. (4) The detector according to claim 1, wherein the member is a plate-shaped base member and a fixing member fixed to the upper surface of the base member at a predetermined pitch. .