JPS6263816A - Displacement sensor - Google Patents

Abstract

PURPOSE:To obtain a displacement sensor of a non-sliding type, having a wide measuring range, by using an optical position detecting element, and also piercing a slender slit of a linear shape or a curved shape on a light shielding plate. CONSTITUTION:An optical position detecting element 10 is irradiated by a light emitting element 14. Between them a light shielding plate 12 on which a slit 12a has been pierced is placed, and it becomes a structure for moving in the direction of a displacement to be measured, together with an object to be measured, through an arm 16. A housing for supporting each part and obstructing an influence of peripheral light is omitted. The detecting direction of the optical position detecting element 10 is orthogonal to the moving direction of the light shielding plate 12. Light is projected to only the part for crossing the slit 12a in a photosensitive part 10a which has been provided on the optical position detecting element 10, and in accordance with its position, an output voltage is obtained. When the light shielding plate 12 moves in the direction as indicated with an arrow as the object to be measured is displaced, the part irradiated by light on the photosensitive part 10a also moves, therefore, a linear input/output relation is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a displacement sensor that converts one-dimensional displacement into an electrical signal.

KPrior Art 1 Conventionally, a typical sensor of this type has been an MvJ type potentiometer. This sensor can obtain a voltage proportional to displacement simply by applying a voltage, and can be said to be an easy-to-use sensor, but it also has the following drawbacks.

(1) Because it is a sliding type, it generates frictional force, which affects the movement of the object to be measured.

(2) Because it is a sliding type, its lifespan is short.

(3) The practical measurement range is several hundred mm at most.

(4) It is expensive.

Non-sliding displacement sensors include differential transformer type and
There are also devices that use inductance and capacitance, which eliminates the drawbacks of (1) and (2) above, but these
The four-piece construction is more complicated and therefore more expensive, and the measurement range is not wide enough.

As a device that does not use sliding contacts and can be manufactured at low cost, the first
As shown in FIGS. 1 and 12, a light shielding plate 22 with a slit 22a is disposed between the light source 24 and the optical position detection element 20 that detects the position of the light spot. There is a displacement sensor in which a light shielding plate 22 is configured to move integrally with the object to be measured via an arm 26 in the detection direction of the optical position detection element 20, that is, in the direction of the displacement to be measured.Optical position detection element 2o Examples include semiconductor device sensors, dog breeds, landscapes, electronic materials, Vol. 19.
NO, 2, ρp, 119-124.1980) and the 1st
A photoelectric potentiometer 30 as shown in FIG. 3 is used. However, in this device, the measurement range is determined by the detection range of the optical position detection element 20,
The practical limit was several tens of millimeters when using a photoelectric potentiometer, and several millimeters when using a semiconductor device sensor. Furthermore, for example, in order to obtain the same degree of accuracy and resolution for a sensor that measures a displacement of 1011111 and a sensor that measures a displacement of 50m1+1, optical position detection elements with different detection ranges must be used. First, it was not possible to standardize parts. Furthermore, the first
As shown in Figure 4, the input/output characteristics had a linear relationship, and it was impossible to set any characteristics other than the linear relationship.

KObjective and main configuration of the invention It is an object of the present invention to provide a displacement sensor that can be freely set and manufactured at low cost.

This invention uses an optical position detection element to achieve a non-sliding type, and the detection direction of the element is arranged so as to be different from the direction of measurement (bevel displacement), and the measurement is performed on a light shielding plate. By drilling a long and narrow slit in a direction that is different from the direction of the desired displacement, the moving direction of the light shielding plate, and the detection direction of the element, it is possible to freely measure a wide range by simply replacing one part (the light shielding plate). By making the shape of the slit linear or curved, it is possible to freely set the relationship between displacement and output other than a linear relationship. It is characterized by being able to be manufactured at low cost from where it is available.

K Specific Embodiments The present invention will be described in detail below with reference to drawings showing embodiments.

FIG. 1 is a side view showing the main parts of a first embodiment of the present invention, and FIG. 2 is a view taken along the line A--A showing the main parts of the first embodiment. The optical position detection element 10 is irradiated with light by the light emitting element 14. A light shielding plate 12 having a slit 12a is disposed between them, and is configured to move together with the object to be measured via an arm 16 in the direction of the displacement to be measured. In this drawing, the casing for supporting each component and preventing the influence of ambient light is omitted.

The detection direction of the optical position detection element 10 is perpendicular to the moving direction of the light shielding plate 12. Photosensitive section 10 of optical position detection element 10
Light is irradiated only to the portion of a that intersects with the slit 12a, and an output voltage corresponding to that position is obtained. Now, when the light shielding plate 12 moves in the direction of the arrow due to the displacement of the object to be measured, the portion of the photosensitive portion 10a that is hit by the light also moves.
An input/output relationship as shown in FIG. 3 is obtained.

When changing the measurement range, the angle and quality of the slit 12a with respect to the moving direction of the light shielding plate 12 may be changed. As an example in which the measurement range is widened, FIG. 4 shows a second embodiment, and FIG. 5 shows the input/output relationship.

By making the shape of the slit 12a non-linear,
Any input/output relationship can be obtained. As an example of a non-linear shape, FIG. 6 shows a third embodiment, and FIG. 7 does not show the input/output relationship.

In the above embodiments, the direction of the displacement to be measured, that is, the moving direction of the light shielding plate 12 and the detection direction of the optical position detection element 10 are orthogonal to each other, but they do not necessarily need to be orthogonal to each other. the direction of the displacement to be measured, the detection direction of the optical position detection element 10,
It is sufficient that J5 and the slit 12a are different from each other in the long axis direction. As an example in which they are not orthogonal, FIG. 8 shows a fourth embodiment, and FIG. 9 shows the input/output relationship.

Furthermore, the measurement range can also be changed by changing the detection direction of the optical position detection element 10.

[Effects of the Invention] This invention is configured as described above, and has the following advantages:
You can obtain the following effects.

(1) Since it is not a sliding type, it does not affect the movement of the object being measured and has a long life.

(2)! You can freely change and set the measurement range by replacing only the tip plate. Furthermore, the measurement range can also be changed by changing the detection direction of the optical position detection element.

<3) The relationship between displacement and output can be freely set.

(4) Can be manufactured at low cost.

[Brief explanation of drawings]

FIG. 1 is a side view showing the main parts of a first embodiment of the present invention;
FIG. 2 is a view taken along the arrow 8-A' showing the main parts of the first embodiment, FIG. 3 is a graph showing the relationship between displacement and output of the first embodiment, and FIG. 4 is a diagram showing the relationship between displacement and output of the first embodiment. FIG. 5 is a graph showing the relationship between displacement m and output of the second embodiment. FIG. 6 is a front view showing the main parts of the third embodiment of the present invention. 7 is a graph showing the relationship between the displacement amount and the output of the third embodiment, FIG. 8 is a front view showing the main part of the fourth embodiment of the present invention, and FIG. 9 is a graph showing the relationship between the displacement amount and the output of the third embodiment. A graph showing the relationship between the displacement amount and the output in the example, Fig. 11 is a side view showing the main parts of the conventional example, and Fig. 12 shows the main parts of the conventional example.B-8'''
13 is a perspective view showing a photoelectric potentiometer, and FIG. 14 is a graph showing the relationship between displacement and output of a conventional example. 10 is an optical position detection element, 10a is a photosensitive portion, 12 is a light shielding plate, 12a is a slit, and 14 is a light emitting element. Patent applicant Jeko Co., Ltd. Figure 1 Figure 3 Figure 12a Slit Figure 4 Figure 5 Figure 6 Procedure correction method July 23, 1986 2, Name of invention Displacement sensor 3, Case of person making correction Relationship with Patent Applicant Address 1-4 Fujimi-cho, Gyoda City, Tama Prefecture
11, 14, date of dispatch of the amendment order) June 24, 1985 (1) "Figure 11 is" in the fourth line of page 8 of the same window is amended as follows. "Figure 10 is," (2) Revise Figure 12 (Yo, l in the 5th line of page 8) as follows. "Figure 11 is," (3) Doubt 8 Amend ``Figure 13 (yo'') on the 6th line of the page as follows. "Figure 13 is" (5) The figure number "Figure 11" in Figure 11 of the drawings is amended as follows: "Figure 10" (6) Figure 11 of the drawings The figure number ``Figure 12'' in Figure 12 has been corrected as follows: ``Figure 11'' (7) The figure number ``Figure 13'' in Figure 13 of the drawing has been corrected as follows. "Figure 12" (8) The figure number "Figure 14" in Figure 14 of the drawings is corrected as follows. "Figure 13"

Claims (1)

[Claims] An optical position detection element arranged so that the detection direction does not match the direction of the displacement to be measured, a light emitting element arranged opposite to illuminate the photosensitive part of the optical position detection element, and an optical position It is disposed between the detection element and the light emitting element so as to be movable in the direction of the displacement to be measured, and has an elongated slit bored in a direction different from the direction of the displacement to be measured and the detection direction of the optical position detection element. A displacement sensor consisting of a light shielding plate.