JPH02300613A - Measuring instrument - Google Patents

Abstract

PURPOSE:To constitute an irradiation means compactly and to increase the width of a measurement range without increasing the diameter nor focal length of a convex lens by cutting off elliptic light only in the minor-axis direction by a slit formation member without cutting off the light in the major-axis direction. CONSTITUTION:An irradiation means 3 shape the light from a light source into slit light L3, which is projected on the measured surface of an object 1 to be measured. An image pickup means 4 picks up the projection image drawn on the measured surface of the object 1 with the slit light L3, converts the image into the quantity of electricity, and outputs it. Further, a measurement unit 2 moves at right angles to the lengthwise direction of the slit light L3 while holding the constant distance to the object 1 by driving the arm 5 of an industrial robot to measure the whole shape of the object 1. Thus, the elliptic light emitted by a laser light source 10 is cut off by the slit formation member 30 only in the minor-axis direction without being cut off in the major-axis direction, so that the slit light is formed.

Description

[Detailed description of the invention] Industrial applications The present invention relates to a measuring device, in particular to the structure of an irradiation means.

Conventional technology When measuring the shape of a measurement target such as a press-formed panel using the principle of triangulation, a measurement unit is attached to the arm of an industrial robot, and the measurement unit is measured by driving the arm of the industrial robot. While moving relative to the object, a slit light is irradiated and projected from the measurement unit onto the measurement part of the measurement object, and this projected image is captured by the imaging means of the measurement unit to measure the overall three-dimensional shape of the measurement object. A measuring device using a so-called optical cutting method is known (see Japanese Patent Laid-Open No. 62-299708).

Problems to be Solved by the Invention In the irradiation means, generally, as shown in FIG. 6 (Y3), light emitted from a light source (not shown) is transmitted through a collimator lens (not shown) and a convex lens (not shown). This circular light is transmitted through a cylindrical concave lens (not shown) and a convex lens (not shown) to form an elliptical shape, and this elliptical light L
2 is passed through the slit & of the slit forming member A to form the slit light L1. However, in order to widen the measurement range by increasing the longitudinal width of the slit beam I-3, it is necessary to increase the diameter and focal length of the convex lens that passes behind the cylindrical concave lens. For this reason, if the width of the measurement range is widened, the diameter and focal length of the convex lens are increased, and the irradiation means will not only become larger, but also
As shown by the hatching in A), the amount of light that is blocked by the slit forming member is large, resulting in a large power loss, and when it passes through the slit forming member, it causes halation due to diffraction.
Slit light■21. It is difficult to use this method in general because it causes blurring.

Means to Solve the Problem In a measuring device that measures the shape of an object using an optical cutting method, the object to be measured is irradiated with slit light.

A laser light source that emits an elliptical laser beam onto the projection irradiation means, a lens system that transmits the elliptical light emitted from the laser light source while expanding it in the long axis direction; A slit forming member having a slit extending in the long axis direction of the elliptical light is provided.

A slit light is formed by blocking only the short axis direction of the elliptical light emitted from the working laser light source with the slit forming member without blocking the long axis direction of the elliptical light with the slit forming member.

EMBODIMENTS As shown in FIGS. 1 to 3, reference numeral 1 indicates an object to be measured, for example, a pile press-formed into a desired shape. Reference numeral 2 denotes a measurement unit, which includes an irradiation means 3 and an imaging means 4. The irradiation means 3 forms the light from the light source into a slit light L3, and irradiates and projects this slit light 53 onto the measurement surface of the measurement object I. The imaging means 4 is structured to capture a projected image drawn by the slit light 1-3 on the measurement surface of the measurement object I, convert it into an electrical quantity, and output it. In addition, the measurement unit 1-2 is driven by the arm 5 of the industrial robot, and moves in a direction perpendicular to the longitudinal direction of the slit beams 1 and 9 while maintaining a constant distance from the measurement object 1. It is designed to measure the entire shape of.

Here, the irradiation means 3 is composed of a laser light source 10, a lens system 20, and a slit forming member 30, as shown in FIG. 1.2.

As shown in FIG. 3, the laser light source IO is composed of a semiconductor laser and emits an elliptical light L2.

The lens system 20 is composed of a collimator lens 2, a cylindrical concave lens 22, and a convex lens 23, which are arranged in order from the laser light source 10 side. The concave axis of the cylindrical concave lens 22 is arranged along the long axis of the elliptical light 172.

The slit forming member 30 is arranged within the lens system 20, and the longitudinal width of the slit 31 is arranged along the long axis of the elliptical light L2, and the short width of the slit 30a is arranged along the short axis of the elliptical light. is located along.

According to the structure of the second embodiment, the longitudinal width of the slit light L3 emitted from the irradiation means 3 is set parallel to the Y-axis direction of the industrial robot, and the slit light L3 is set parallel to the X-axis direction of the industrial robot. While driving the arm 5 of the industrial robot so as to move in parallel, the slit light L3 is irradiated and projected onto the measurement object I, and this projected image is captured by the imaging means 4 to measure the overall shape of the measurement object 1. .

Here, the elliptical light emitted from the laser light source 10,
2 is formed into parallel beams 1-4 by a collimator lens 21,
When this parallel light 174 passes through the convex lens 23 via the cylindrical concave lens 22 and the slit 3I of the slit forming member 30, the concave axis of the cylindrical concave lens 22 and the longitudinal width of the slit 3I of the slit forming member 30 form an ellipse. Since it is arranged along the long axis of the shaped light T,2,
As shown in FIG. 1, when viewed from the short axis direction of the elliptical light, it is not blocked by the slit 31, and reaches the convex lens 23 while undergoing a diverging effect by the cylindrical concave lens 22, and is then converged by the convex lens 23. It becomes parallel light and is irradiated and projected onto the measurement object 1.

On the other hand, the light is emitted in an elliptical shape (not shown in Figure 2), and when viewed from the long axis direction, the parallel light L4 reaches the slit forming member 30 as the parallel light L4 and is blocked by the slit 3I, without being diverging by the cylindrical concave lens 22. The light reaches the convex lens 23 with the required width, receives a focusing action by the convex lens 23, and is then irradiated and projected onto the measurement object 1'' as slit light 1-3. In other words, since the concave axis of the lindrical concave lens 22 is arranged along the long axis of the elliptical light [7°, the slit light 7
3 becomes larger in length, thereby widening the measurement range. Moreover, since the longitudinal width of the slit 31 is arranged along the long axis of the elliptical light L2, the amount of light blocked by the slit forming member 30 is reduced, as shown in FIG. 5(B), and power loss is small. As shown in FIG. 5(A, ), since no halation occurs due to diffraction when the light passes through the slit forming member 30, a sharp image without blur can be formed.

Effects of the Invention As described above, according to the present invention, only the short axis direction of the elliptical light emitted from the laser light source is blocked by the slit forming member without blocking the long axis direction of the elliptical light emitted by the slit forming member. As a result, a slit light can be formed.
There is no need to increase the diameter and focal length of the convex lens,
The irradiation means can be configured compactly, the measurement range can be widened, and a projected image without blur can be formed. .

[Brief explanation of drawings]

Fig. 1 is a block diagram of the main part of an embodiment of the present invention viewed from the short axis direction of the elliptical light, and Fig. 2 is a block diagram of the main part of the same embodiment seen from the long axis direction of the elliptical light. , FIG. 3 is a perspective view of the laser light source of the same embodiment, FIG. 4 is a block diagram showing the entire structure of the same embodiment, FIG. 5 is an explanatory diagram of the operation of the same embodiment, and FIG. 6 is an explanatory diagram of the conventional operation. It is. I...Measurement target, 2. Irradiation means, IO/laser light source,
20 Lens system, 30 - Slit forming member. −8= @l Δ Δ to section m

Claims (1)

[Claims] (1) In a measuring device that measures the shape of a measurement target using the optical cutting method, a laser light source that emits an elliptical laser beam is provided to an irradiation means that irradiates and projects a slit light onto the measurement target, and a laser light source that emits an elliptical laser beam is emitted from the laser light source. The present invention is characterized by comprising a lens system that transmits the elliptical light while expanding it in the major axis direction, and a slit forming member disposed within the lens system and having a slit extending in the major axis direction of the elliptical light. measuring device.