JPH06249648A - Displacement gauge - Google Patents

Abstract

PURPOSE:To obtain a displacement gauge having high resolution and wide measuring range by providing optical fiber bundles for guiding light beams emitted from a light source. CONSTITUTION:The title gauge M is provided with a laser light source 1, projection lens 2, light receiving lens which receives a light spot farmed on a surface P to be measured, and semiconductor position detecting element (PSD) on which the image of the light spot is formed. The light source 1 emits light beams in tow directions through optical fiber bundles 5. One of the bundles 5 constitutes a first light guiding section 5a through which one of the light beams is emitted perpendicularly to the surface P and the other of the bundles 5 is a second light guiding section 5b through which the other light beam is obliquely emitted. When the distance to the surface P is to be made longer, the displacement of the surface P is measured by irradiating the surface P with the light beam emitted through the first light guiding section 5a and forming the image of the light spot on the PSD 4. When the surface P is, for example, a mirror surface or when the resolution is to be improved, the surface P is irradiated with the light beam emitted through the second light guiding section 5b and the displacement of the surface P is measured from the regular reflected light of the light beam.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement meter for measuring the amount of displacement of a surface to be measured, and more specifically, a semiconductor position detecting device (PSD; Position Sensitivity).
The present invention relates to a displacement meter by a triangulation method using a ve Detector).

[0002]

2. Description of the Related Art As schematically illustrated in FIG.
This type of displacement meter includes a laser light source 1 as a light source. The light emitted from the laser light source 1 is focused into a thin light beam by the light projecting lens 2 and is irradiated onto the surface P to be measured.

This light beam is reflected by the surface of the surface P to be measured and is observed as a light spot on the surface. This spot is
An image is formed on the PSD 4, which is a semiconductor position detecting element, by the light receiving lens 3 having an optical axis forming a predetermined angle α with the light beam.

When the surface P to be measured is displaced from P ₁ to P ₂ , the image formation point on the PSD 4 is also displaced from P ₁ ′ to P ₂ ′, and the displacement of the surface to be measured P from the displacement P ₁ ′ is changed to P ₂ ′. The amount of displacement is calculated.

According to this, the amount of displacement can be measured in a non-contact manner, and the influence of the color of the surface to be measured is less than that in the displacement meter of the reflected and received light type.

[0006]

However, the reference distance (the distance to the intersection of the optical axis of the light receiving lens and the light beam)
The longer the value, the lower the resolution. On the other hand, if the surface to be measured is a flat mirror surface or if the resolution is to be increased, irradiating the surface to be measured with laser light from an oblique direction shortens the reference distance.For example, it is dangerous to approach the surface to be measured. In some cases, you will not be able to separate from it.

[0007] In short, there is a drawback that a single displacement meter has a limited measuring range and resolution.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional circumstances, and its structural features are a laser light source for irradiating a light beam toward a surface to be measured, and a light source for the light beam. A light receiving lens having an optical axis forming a predetermined angle, and a semiconductor position detecting element on which the light spot on the surface to be measured is imaged by the light receiving lens, and the image forming point position on the semiconductor position detecting element In a displacement meter that measures the amount of displacement of the surface to be measured by triangulation based on, an optical fiber bundle that guides the light beam emitted from the laser light source is provided, and the optical fiber bundle has a surface to be measured. On the other hand, the first light guide portion for vertically irradiating the light beam and the light beam for irradiating the arbitrary measurement surface parallel to the measurement surface at a predetermined angle are reflected by the light receiving lens. Through the above semiconductor In that the second light guide portions which are angled is provided so as to be incident 置検 out on the device.

[0009]

When it is desired to increase the distance from the surface to be measured, the first light guide section irradiates the surface to be measured with a light beam perpendicularly, and the light spot is moved to the semiconductor position via the light receiving lens. An image is formed on the detection element (PSD).

On the other hand, when the surface to be measured is a flat mirror surface or when it is desired to increase the resolution, the second light guide unit irradiates the surface to be measured so as to specularly reflect the light beam. Then, the light spot is imaged on the PSD through the light receiving lens.

As described above, by making it possible to switch the irradiation angle to the surface to be measured, for example, in two ways, it is possible to construct a displacement meter having a high resolution and a wide measurement range with one displacement meter.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. According to this, the displacement meter M receives the laser light source 1, the projection lens 2 that narrows the emitted light into a thin light beam, and the light spot on the surface P to be measured, as in the conventional device shown in FIG. Light receiving lens 3 and a semiconductor position detecting element (PS
D) 4 is provided, but in this case, the light beam narrowed down by the light projecting lens 2 is irradiated through the optical fiber bundle 5 in two directions.

That is, according to this embodiment, the light emitting side of the optical fiber bundle 5 is branched into two directions, one of which is the first light guide portion for irradiating the surface to be measured with a light beam perpendicularly. 5a, the other is a second light guide portion 5b for irradiating the surface to be measured with a light beam from an oblique direction.

The irradiation angle of the second light guide portion 5b with respect to the surface to be measured is preferably 45 degrees in the sense of utilizing regular reflection. Therefore, the optical axis of the light receiving lens 3 is also 4 with respect to the light beam emitted from the first light guide portion 5a.
It is preferable to set to intersect at 5 degrees.

Although not shown, the optical fiber bundle 5 is provided with beam switching means for selectively switching the light beam to either the first light guide portion 5a or the second light guide portion 5b. ing.

For example, when it is desired to increase the distance from the surface P to be measured because it is dangerous to approach, the first
A light beam is vertically emitted from the light guide portion 5a of the optical pickup unit 5a onto the surface P to be measured, and the light spot thereof is received in the same manner as in the conventional case.
An image is formed on the PSD 4 via the and the displacement amount is measured.

On the other hand, when the surface P to be measured is, for example, a mirror surface, or when it is desired to improve the resolution, the light beam is switched to the second light guide portion 5b side, and the light beam is changed to the surface to be measured. The amount of displacement can be measured by irradiating P at an angle of 45 degrees and forming an image of the specularly reflected light on the PSD 4 via the light receiving lens 3.

In the above embodiment, the second light guide section 5 is used.
The optical axis of the light receiving lens 3 is set so as to intersect the light beam from the first light guide portion 5a at a light receiving angle of 45 degrees in accordance with the use of regular reflection at the time of measurement by b. According to the measurement mode, the optical axis of the light receiving lens 3 and P
SD4 and the like may be adjustable.

For example, when the first light guide portion 5a is used, the light receiving angle of the light receiving lens 3 is set to 30 degrees, while when the second light guide portion 5b is used, the light receiving angle is set to 30 degrees. The angle can also be adjustable to 45 degrees. Also,
The irradiation angle of the second light guide portion 5b may be arbitrarily adjusted.

[0020]

As described above, according to the present invention, since the irradiation angle of the light beam with respect to the surface to be measured is variable, it is not necessary to select the model according to the object to be measured as in the prior art, and A displacement gauge with high resolution and a wide measurement range can be obtained on a table.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a conventional displacement meter.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 laser light source 2 light projecting lens 3 light receiving lens 4 semiconductor position detecting element (PSD) 5 optical fiber bundle 5a first light guide section 5b second light guide section P P surface to be measured

Claims (1)

[Claims] 1. A laser light source for emitting a light beam toward a surface to be measured, a light receiving lens having an optical axis forming a predetermined angle with respect to the light beam, and light on the surface to be measured by the light receiving lens. A laser beam source, comprising: a semiconductor position detecting element for forming an image of a point; and a displacement meter for measuring a displacement amount of the measured surface by a triangulation method based on an image forming point position on the semiconductor position detecting element. An optical fiber bundle for guiding a light beam emitted from the first optical fiber bundle, the first optical beam bundle emitting the light beam perpendicularly to the surface to be measured.
The light guide section and the surface to be measured parallel to the surface to be measured are irradiated with a light beam at a predetermined angle, and the reflected light is incident on the semiconductor position detecting element via the light receiving lens. And a second light guide portion that is angled so that the displacement meter is provided.