JPS6281514A - Radius of curvature gauge - Google Patents

Abstract

PURPOSE:To make measurement of a curvature of a specimen surface only by opposed arrangement of the specimen and three and more light projectors, by constructing in such a way that they are operated in time sequence. CONSTITUTION:A light source 11a of a light projector 11 is turned on by an output signal of a timing generator 17 and a light spot 4a of proper size is directed onto a specimen 3 by a light-projecting lens 11a. An image of this light spot 4a is developed on the light-receiving plane of a light-receiving element 14b by a light-receiving lens 14a. Next, source 12a of a light-projector 12, source 13a of a light-projector 13 are operated in time sequence and light spots 4a, 4b, 4c formed onto 3 and more points of the specimen by each projector 11, 12, 13 are received in a light-receiver 14 alternately and from distance outputs to each point oriented by outputs of this light-receiver 14, the curvature of the measurement surface of the specimen 3 can calculated.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a curvature measuring device that measures the curvature of a surface to be measured of a target object in a non-contact manner.

[Conventional technology]

Figure @2 shows a non-contact distance measuring device that is conventionally used to measure the curvature of target objects such as a sphere, 2 cylinders, and a cylinder. This is a projection lens that focuses the emitted light beam and projects it onto the target object 3 to be measured. Above light source 1, light projection lens 2
．． The target object 3 is located on the axis A, and the light emitted from the light source 1 is irradiated onto the target object 3 by the projection lens 2.
Photospora of the luminous flux) 4t- forms.

5 is a light receiving lens that forms an image of the light spot 4; 6 is a position P of the image of the original spot 4 formed by the light receiving lens 5;
Electrical output iA, iBf corresponding to: the light receiving element that generates the light spot 4. Light receiving lens 5. The light receiving element 6 is located on the axis B, and in this case, the axis B makes an angle θ with the axis A.

Then, two electrical signals iA, t output from the light receiving element 6
B is input to an adder T and a subtracter 8, respectively, and the adder 7 calculates the sum of both signals (iA+iB), and the subtracter 8 calculates the difference between the two signals (tA-iB). .

9 is a divider that divides the output of the subtracter 8 by the output of the adder T;
10 is a converter that converts the position output pt of the divider 9 into a distance output t.

Next, the operation will be explained. The light emitted from the light source 1 is originally a spot 4 of an appropriate size by the projection lens 2.
The target object 3 is irradiated with the light. The light-receiving lens 5 images this original spot 4, and forms an image of the original spot 4 on the light-receiving portion of the light-receiving element 6.

Such a light receiving element 6 includes, for example, an original position detector that outputs an optical signal proportional to the imaging position of the spot image toward both ends, and an original position detector arranged at both ends of this original position detector and arranged on the light receiving surface. It is composed of a photodetector that generates electrical signals t, , iB according to the input original signal. Therefore, the imaging position P of the one-dimensional spot image is determined by the values of the electric signals t, , tB.
teeth.

tA+tB It can be found as

By the way, the output of the light receiving element 6 produces an output signal proportional to the imaging position P of the original spot image and its intensity. Therefore, in Equation (1) above, the term (iA+iB), which is a signal that changes in proportion to the intensity change of the one-dimensional spot image, is introduced into the denominator, and a signal that is proportional only to the imaging position of the original spot image is introduced into the denominator. I'm trying to get it.

The adder 7, subtracter 8, and divider 9 are circuits for implementing the calculation shown in the above equation (1) based on the output signals i A and i B of the light receiving element 6, and in this way, At the output of the divider 9, an output value P corresponding to the imaging position of the original spot image is obtained.

On the other hand, the distance to the target object 3 is t-t, and the projection lens 2
and the installation interval tL of the light-receiving lenses 5.

t can be determined as t=-...(21-θ). Here, θ is the light receiving lens 5.
It is determined by the installation position and focal length of , the installation interval between the light-receiving element 6 and the light-receiving lens 5, and the output P related to the imaging position of the original spot image. Since all of these except the position output P can be determined as fixed values, in the end, the target object 3
The distance t is.

t=to-P...
...obtained as 131. In this case, % is a constant determined by each of the above fixed values, and is set by prior calculation or experiment. The converter 10 implements the above equation (3) and 1
The position output Pft is inputted and outputted to the distance output 11.

Therefore, the distance measuring device is moved horizontally by a moving mechanism (not shown), the distance is measured for at least three points on the target object 3, and the distance output for each point is input to a curvature calculator (not shown) for calculation processing. Then, the curve ``4'' of the measurement surface of the target object 3 is determined.

[Problem that the invention seeks to solve]

Conventionally, the curvature of the measurement surface is measured as described above, so the distance measuring device must be moved horizontally, and this moving device 2 and a control device to control the moving device are required, resulting in a complicated configuration. The problem was that it was expensive.

This invention was made to solve the above-mentioned problems, and provides an inexpensive curvature measuring device with a simple configuration that can measure the curvature of a measurement surface in a fixed state without horizontal movement. The purpose is to

[Means for solving problems]

The curvature measuring device according to the present invention has one light receiving section and three or more light projecting sections operated in one time series.

[Effect]

The three or more light projecting sections in the second aspect of the present invention operate in chronological order, so that original spots formed at three or more points on the target object by each light projecting section are alternately received by one light receiving section,
The curvature of the measurement surface of the target object is calculated based on the distance output to each point determined based on the output of the light receiving section.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

2 in FIG. 1, 11 is a light source 11a and a light projection lens 11b.
12 is a light source 12a and a light projecting lens 12.
13 is a light emitting unit consisting of a light source 13a and a light emitting unit 13;
3b, and 14 is a light receiving section consisting of a light receiving lens 14a and a light receiving element 14b. The assembly is fixed to the case 15. 16 is a distance calculator that generates a distance output based on the output of the light receiving section 14, and is the adder and subtracter shown in the above-mentioned diagram Wc2.

It is composed of a divider, a converter, 2, and a memory for storing the calculation result 'f. 17 is the three light projecting parts 11~
13 in time series.

Next, the operation will be explained. First, the source 11a of the light projector 110 is turned on using the output signal of the timing generator 17,
A suitable size original socket) 4 using the projection lens 11a
At-target object 3 is irradiated.

This original spot 4aF) image is formed on the light-receiving surface of the light-receiving element 14b by the light-receiving lens 14a.

The electric signals iA, LB outputted from the light receiving element 14b corresponding to this imaging position are inputted to the distance calculator 16,
The calculated distance output is stored in -H memory (not shown).

Next, the light source 11'a of the light projecting section 11 is turned off using the output signal of the timing generator 1T, and the light projecting section 12 is turned off.
The light source 12a'i is turned on, the distance to the original spot 4b irradiated onto the target object 3 is measured by the same operation as described above, and this distance output is stored in the -H memory.

Subsequently, the output signal of the timing generator 17 causes the light emitting unit 1 to
The light source 12a'jz of the light projector 13 is turned on while the light source 12a'jz of the light projector 13 is turned on, and the distance of the light irradiated onto the target object 3 is measured at 4cf, and this distance output is stored in the memory.

After that, the original spots on the target object 3) 4a, 4b.

Each distance output at 4el is read out from the memory and input to the curvature calculator 1B to calculate the curvature of the measurement surface of the target object 3.

In the above embodiment, there are three light projecting units, but three or more light projecting units may be provided, and the same effects as in the above embodiment can be obtained.

〔Effect of the invention〕

As described above, according to the present invention, three or more light projectors are configured to operate in chronological order just in case.

The curvature of the measurement surface of a target object can be measured simply by arranging it facing the target object. ! ! Note that since the light projecting section operates in a time-series manner, it is possible to obtain a single curvature measuring device with a simple configuration and at low cost by using only one light receiving section.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram of a curvature measuring device showing an embodiment of the present invention, and FIG. 2 is a block diagram of a distance measuring device conventionally used for measuring curvature. 11 to 13 are light projecting parts, and 11a to 13a are light sources. 11b to 13b are projecting lenses, 14 is a light receiving section, 14a is a light receiving lens, 14b is a light receiving element, 16 is a distance calculator, 1
7 is a timing generator, and 1B is a curvature calculator. In Figure 21, the same reference numerals indicate the same or equivalent parts. Patent applicant Mitsubishi Electric Co., Ltd. agent Patent attorney 1) Hiroshi Fuchi Showa procedural amendment (voluntary) Showa 6 Akira 1゛1B

Claims (1)

[Claims] At least three or more light projecting parts each consisting of a light source and a light projecting lens that irradiates the light from the light source onto a target object as a light spot of an appropriate size, and a light receiving lens that forms an image of the light spot. and a light receiving element that outputs a plurality of electrical signals proportional to the imaging position of the image;
a timing generator that operates the three or more light projectors in chronological order; a distance calculator that generates a distance output based on the electrical signal; A curvature measuring device comprising a curvature calculator that calculates the curvature of a measurement surface of a target object.