JPH04337413A - Displacement measurement device - Google Patents

Abstract

PURPOSE:To obtain a displacement measurement device by which displacement of the bottom part of such as a deep hole can be also measured. CONSTITUTION:End sides of first prism 11 as well as of a second prism 12 are inserted into a deep hole 22 of an objective 21 to be measured. The ends of the first as well as of the second prisms 11, 12 will not be in contact with a bottom part 23 of the deep hole 22. A light shaft is irradiated on a reflection surface 13 of the first prism 11 from a light emitter 2 through a lens 3. The light shaft is bent on the reflection surface 13 by 90 deg., and is linearly transmitted in the first prism 11, and is irradiated from am output end 14 and is reflected on the bottom part 23. The reflected light is input from an input end 16 of the second prism 12, and is repeatedly reflected in the second prism 12 while reflected on a reflection surface 15, and the light is converged by a lens 5, and an image is formed on a line sensor 6.

Description

[Detailed description of the invention]

[Object of the invention]

0002

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a displacement measuring device for measuring displacement at the bottom of a hole, for example.

0003

2. Description of the Related Art As a conventional displacement measuring device of this type, for example, a device having a configuration shown in FIG. 3 is known.

The displacement measuring device 1 shown in FIG. 3 applies the principle of triangulation to easily detect minute surface irregularities using light in a non-contact manner with high precision and high speed.

The displacement measuring device 1 is provided with a light projector 2 for emitting light, and a lens 3 for condensing the light emitted from the light projector 2. Further, a lens 5 is provided which scatters and reflects the light irradiated through the lens 3 on the object to be measured 4 and focuses the reflected light again, and receives the light focused by the lens 5. A line sensor 6 is provided as a light receiver.

Then, light is emitted from the projector 2, focused by the lens 3, and reflected by the object to be measured 4. The reflected light is focused by the lens 5, and the position of the object to be measured 4 is determined. The optical axis is changed depending on the difference, an image is formed by the line sensor 6, an electric signal corresponding to the light receiving position of the line sensor 6 is outputted, and the position of the object 4 to be measured is detected by triangulation.

That is, if the distance between the displacement measuring device 1 and the object to be measured 4 is short, the angle of incidence and reflection angle of the optical axis reflected by the object to be measured 4 will be relatively wide; When the distance between the device 1 and the part to be measured 4 is long, the angle between the incident angle and the reflection angle of the optical axis becomes relatively narrow, and the difference in these angles causes a difference in the position where the image of the line sensor 6 is formed.

[0008]

[Problems to be Solved by the Invention] However, when detecting the position of the object to be measured 4 using the conventional displacement measuring device 1 shown in FIG. The space must be such that both the optical axis and the optical axis reflected by the object to be measured 4 and imaged on the line sensor 6 via the lens 5 can pass through.

For this reason, using the conventional triangulation method,
In the case of the displacement measuring device 1 shown in FIG. 1, when the object to be measured 4 is a deep hole, the optical axis is blocked by the periphery of the deep hole, and the problem is that displacement at the bottom of the deep hole cannot be detected.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a displacement measuring instrument that can also measure displacement at the bottom of a deep hole or the like.

[Configuration of the invention]

0012

[Means for Solving the Problems] The displacement measuring device of the present invention has the following features:
a first prism that irradiates the object to be measured with the light emitted from the projector; and a first prism that receives the reflected light emitted from the first prism and reflected by the object to be measured. This device is equipped with a second prism and a light receiver that receives light from the second prism and measures the displacement of the object according to the light receiving position.

[0013]

[Operation] In the present invention, the light emitted from the projector is directed to the part to be measured through the first prism, and the light reflected from the part to be measured is sent to the receiver through the second prism. By receiving light and measuring the displacement of the part to be measured using the triangulation method, the light can be reflected by the part to be measured without blocking the light, regardless of the presence or absence of surrounding light obstructions. It is also possible to measure the displacement at the bottom of a deep hole containing an object.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the displacement measuring device of the present invention will be described below with reference to the drawings.

[0015] Note that the same parts as the conventional example shown in Fig. 3 include:
The description will be given using the same reference numerals.

The displacement measuring instrument 1 shown in FIG. 1 is provided with a light projector 2 for emitting light, and a lens 3 for condensing the light emitted from the light projector 2.

On the opposite side of the lens 3 from the optical axis from the projector 2, there are first and second prisms 11 and 12.
is provided. The first prism 11 has an elongated shape, and one end thereof is formed with a reflective surface 13 cut into a slope at 45° with respect to the longitudinal direction, and the other end is formed with an output end 14 perpendicular to the longitudinal direction. Then, this first prism 11 is perpendicular to the optical axis from the projector 2, and the reflective surface 1
The inner surface of 3 faces the projector 2, and the optical axis is set at 9 with the reflective surface 13.
It is refracted by 0°. Further, the second prism 12 is also
The second prism 12 is elongated like the prism 11 of
is longer than the first prism 11. Furthermore, like the first prism 11, one end of this second prism 12 is formed with a reflective surface 15 cut out on an inclined surface at an angle of 45 degrees with respect to the longitudinal direction, and the other end is formed with an input end 16. . This second prism 12 is the same as the first prism 11.
The first prism 11 contacts the first prism 11 in parallel with the first prism 11, and is located below the optical axis of the first prism 11.

Furthermore, the reflective surface 1 of this second prism 12
5 is provided with a lens 5 that refocuses the reflected light,
A line sensor 6 is provided as a light receiver that receives the light focused by the lens 5.

Next, the operation of the above embodiment will be explained.

First, the other ends of the first prism 11 and the second prism 12 are inserted into the deep hole 22 of the object to be measured 21 . At this time, the first and second prisms 11 and 12
A gap is provided so that the tip of the other end does not come into contact with the bottom 23 of the deep hole 22.

Then, the optical axis is irradiated from the projector 2 through the lens 3 onto the reflective surface 13 of the first prism 11 . The optical axis is refracted by 90 degrees at this reflective surface 13, and the first prism 1
1 and is irradiated from the output end 14 to the bottom 2.
It is reflected at 3. This reflected light is input from the input end 16 of the second prism 12, is repeatedly reflected within the second prism 12, is reflected by the reflective surface 15, is focused by the lens 5, and is condensed to the line sensor 6. Image.

The image forming position on this line sensor 6 changes in proportion to the depth of the bottom 23, similar to the optical path of the object to be measured 4 equivalently shown in FIG. 6 outputs an electric signal according to the light receiving position, and can detect the depth, which is the displacement, by triangulation.

That is, the deeper the bottom 23 is, the smaller the reflection angle is, and conversely, the shallower the bottom 23 is, the larger the reflection angle is. Therefore, the deeper the bottom 23 is, the closer the light receiving position of the line sensor 6 is to the projector 2; Move away from floodlight 2.

Note that in the displacement measuring device 1 shown in FIG.
Since the optical path of -R and the optical path of P0-R are set equal, the first and second prisms 1 can be adjusted without calibration.
1 and 12, the displacement can be measured in the same manner as in the case without the 1 and 12.

Further, the projector may use laser light, such as semiconductor laser light, or other highly convergent light in general.

Furthermore, in the embodiment, an example was described in which the light is emitted below the optical axis, but the direction of the emitted light is not limited to this.

Further, the case of setting the distance between the cathode of the electron gun assembly of a cathode ray tube and the second grid using the displacement measuring device 1 shown in FIG. 1 will be described with reference to FIG. 3.

This electron gun assembly 30 has a first grid 32
, a second grid 33, a third grid 34, a fourth grid 35, a fifth grid 36, and a sixth grid 37 are connected linearly, and the cathode 31 is connected to the first grid 32 side. The inner diameters 41, 42 of the first and second grids 32, 33 are about 0.5 mm, the inner diameter 43 of the third grid 34 is about 2 mm, and the inner diameters of the fourth to sixth grids 35, 36, 37 are about 5 mm. It is set.

[0029] Then, the cathode 31 and the first grid 3
2, for example, when setting the interval to 0.1 mm ± 5 μ, the first to sixth grids 32, 33, 34, 35, 36,
37, the displacement of the cathode 31 with respect to the second grid 33 is measured and aligned.

[0030]

Effects of the Invention According to the displacement measuring device of the present invention, the light emitted from the projector is irradiated onto the part to be measured via the first prism, and the light reflected from the part to be measured is transmitted to the second prism. The light is received by the receiver through the prism, and the displacement of the measured part is measured using the triangulation method.The light is reflected by the measured object without blocking the light, regardless of the presence or absence of surrounding light obstructions. This allows for non-contact, high-precision, and high-speed measurement of displacement at the bottom of a deep hole with surrounding optical obstructions.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a displacement measuring device of the present invention.

FIG. 2 is an explanatory diagram of measuring an electron gun of a cathode ray tube using the displacement measuring device.

FIG. 3 is an explanatory diagram showing a conventional displacement measuring device.

[Explanation of symbols]

1 Displacement measuring device 2 Floodlight 6 Photo receiver 11 First prism 12 Second prism 21 Object to be measured

Claims (1)

[Claims] 1. A projector that irradiates light, a first prism that irradiates the object to be measured with the light irradiated from the projector, and reflected light that is irradiated from the first prism and reflected by the object to be measured. A displacement measuring device comprising: a second prism into which light is incident; and a light receiver that receives light from the second prism and measures the displacement of the object according to the light receiving position.