JPH0450616A - Slant sensor - Google Patents

Abstract

PURPOSE:To obtain a slant sensor which is resistant to electromagnetic disturbance by providing a rectangular paralleopiped container wherein liquid is contained, a lower light emitting element and a two-dimensional light-position detector which detects a reflected plate that is floating on the liquid and detects the position of the reflected wave. CONSTITUTION:For example, a liquid layer 1 comprises liquid such as a water. The liquid layer 1 is contained in a rectangular paralleolopiped container 2. Homogenous gas 3 is contained in the container 2. A laser diode (LD hereinafter) 4 as a light emitting element emits the light on the lower surface along the central axis of the container 2. A reflecting plate 5 is formed by the vapor deposition of metal on the surface of, e.g. plastic. The plate 5 has a spectic gravity smaller than the specific gravity of the liquid layer 1. The plate 5 is arranged in the upward facing direction at the boundary between the gas 3 and the liquid layer 1 so that the light emitted from the Ld 4 can be reflected. The light receiving surface of a two-dimensional-position detector (two-dimensional PSD hereinafter) 6 is located at the inside of the upper surface of the container 2. The PSD 6 is arranged at a right angle with respect to the central axis of the container 2 in the downward facing pattern. The PSD receives the light which is emitted from the LD 4 and reflected from the reflecting plate 5. The PSD 6 detects the position of the light in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a tilt sensor, and particularly to a tilt sensor that can be applied to detect the tilt of a device.

[Conventional technology]

As a conventional technique, for example, equity
As shown in Japanese Patent No. 5, there is a tilt sensor using a magnetic fluid and an open magnetic path magnetic core.

A conventional tilt sensor has an open magnetic path magnetic core with an excitation winding,
and a container containing a magnetic fluid placed on the open magnetic path magnetic core.

Next, a conventional tilt sensor will be explained with reference to the drawings.

The third section is a sectional view showing an example of a conventional tilt sensor.

The excitation winding 7 is connected to the central body of the U-shaped magnetic core 8, and the output winding 9.1
0 is applied to each leg 11.12. The container 13 rests on the U-shaped magnetic core 8, and contains the magnetic fluid 14 inside.

First, the magnetic fluid 14 is excited by the U-shaped magnetic core 8. When the magnetic fluid 14 is tilted, the magnetic flux of the U-shaped magnetic core 8 changes due to the change in the magnetic flux passing through the inside thereof, and a differential output voltage is generated in the a-shaped winding 9.10, thereby changing the tilt angle. .

[Problem to be solved by the invention]

The conventional inclination sensor described above detects inclination by changes in magnetic flux due to the inclination of the magnetic fluid, so it is vulnerable to electromagnetic disturbances.
Another drawback is that it is difficult to use in devices that dislike magnetism because it generates magnetism itself.

[Means to solve the problem]

The inclination sensor of the present invention includes a rectangular parallelepiped container containing a liquid, a light emitting element that irradiates light onto the lower surface along the central axis of the container, and a light emitting element having a specific gravity smaller than that of the liquid. It includes a floating reflector and a second-dimensional optical position detector that detects the position of the reflected light from the front reflector.

〔Example〕

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the present invention.

The tilt sensor shown in FIG. 1 includes a liquid layer 1 made of a liquid such as water, and a rectangular parallelepiped container 2 containing the liquid layer 1.
, a homogeneous gas 3 placed inside the container 2, a laser diode (hereinafter referred to as LD) 4 as a light emitting element that irradiates light onto the bottom surface along the central axis of the container 2, and a metal on the surface of, for example, plastic. A reflector plate that is made by vapor deposition, has a specific gravity smaller than that of the liquid layer 1, and is placed on the dirt floor so that it can reflect the light irradiated from the LD 4 at the boundary between the gas 3 and the liquid layer 1. 5, the light-receiving surface is on the inside of the upper surface of the container 2, and is arranged downward so as to be perpendicular to the central axis of the container 2, and receives the light emitted from the LD 4 and reflected by the reflector 5, and determines the position. It is configured to include a two-dimensional position detector (hereinafter referred to as two-dimensional PSD) 6 for detection.

FIG. 2 is a principle diagram in which a two-dimensional slope is divided into components in two directions that intersect at right angles, and only one of the slope components is shown.

Here, the inclination angle of the container 2 with respect to the horizontal is θ, and from the intersection of the reflection surface of the reflection plate 5 and the light irradiated from the LD 4,
The distance to the light receiving surface of 2D PSD 6 is D, 2D PSD
Let X be the distance of the light received at step 6 from the central axis of the container 2.

The angle of incidence of the light emitted from the LD 4 on the reflecting plate 5 is geometrically θ, and the angle of reflection of the light reflected on the reflecting plate 5 is θ according to the law of reflection. From these facts, equation (1) holds for the inclination angle θ.

Solving for θ yields equation (2).

θ = tan-t (1) ...Although D in (2) is known, X
By measuring , the inclination angle θ can be determined.

Another slope component can be obtained in the same manner, and thereby a two-dimensional slope can be measured.

〔Effect of the invention〕

The inclination sensor of the present invention is resistant to electromagnetic disturbance because it determines the inclination by detecting changes in the reception position of reflected light generated by the inclination of the liquid instead of detecting the magnetic flux due to the inclination of the magnetic fluid. Since it does not generate magnetism, it has the advantage that it can be used in devices that dislike magnetism.

The figure shows the principle of dividing a two-dimensional inclination into components in two directions intersecting at right angles and shows only one of the inclination components, and FIG. 3 is a cross-sectional section showing an example of the conventional technique.

1...liquid, 2...container, 3...homogeneous gas, 4...
...LD, 5...Reflector, 6...2D PSD.

Claims (1)

[Claims] a rectangular parallelepiped container containing a liquid; a light emitting element that irradiates light onto the bottom surface along the central axis of the container; and a reflecting plate having a specific gravity smaller than the specific gravity of the liquid and floating on the liquid; a second detecting the position of the reflected light from the reflecting plate;
and a dimensional optical position detector.