JPS6281509A - Distance measuring apparatus - Google Patents

Abstract

PURPOSE:To measure quickly distance between specimens and groove width etc., allowing measuring light fluxes to be emitted in 2 back-to-back directions and simultaneous measurements of 2 points. CONSTITUTION:Light fluxes 25 transmitted through lenses 16, 17 other emission from a light source 15 have its part 25a reflected by a half-mirror 18 and this reflected beam is directed to a light spot Pa on specimen 19a from the second light emission opening 14a. The balance of the fluxes 25 after transmitted through the half-mirror 18, is reflected by a mirror 20 to reach the half-mirror 18 again and after reflection by the half-mirror 18, they are directed on a specimen 19b to a light spot Pb from the aperture 14a. Light-receiving lenses 21a, 22b photograph images of said light spots Pa, Pb and pick up these images on light-receiving surfaces of light-receiving elements of 22a, 22b and electric signals depending upon these image positions are subjected to arithmetic operations by distance-calculating units 23a, 23b and a distance D between the specimens 19a, 19b can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a distance measuring device that measures the distance to a target object.

[Conventional technology]

FIG. 2 shows a conventional non-contact distance measuring device. In the figure, 1 is a light source, and 2 is a projection that focuses the luminous flux emitted from the light source 1 and projects it onto the target object 3 to be measured. It is a light lens.

The light source 1, the light projection lens 2, and the target object 3 are located on the axis A, and the light emitted from the light source 1 is irradiated onto the target object 3 by the light projection lens 2 to form a light spot 4 of a luminous flux.

5 is a light receiving lens that forms an image of the light spot 4; 6 is a light receiving element that generates an electric signal corresponding to the imaging position P of the image of the light spot 4 formed by the light receiving lens 5; , the light-receiving lens 5, and the light-receiving element 6 are located on the axis B, and in this case, the axis B makes an angle θ with the axis A.

Then, the two electrical signals 'A+' output from the light receiving element 6
B is input to an adder 7 and a subtracter 8, respectively, the adder 7 calculates the sum of both signals (iA+in), and the subtracter 8 calculates the difference between the two signals (iA-iB). 9 is a divider that divides the output of the subtracter 8 by the output of the adder 7, and 10 is a converter that converts the position output P of the divider 9 into a distance output.

In the above, a light source 1, a light projecting lens 2, a light receiving lens 5,
The light receiving element 6 constitutes a detection head 11, and the adder 7, subtracter 8, divider 9, and converter 10 constitute a processing section 12.

Next, the operation will be explained. The light beam emitted from the light source 1 is converted into a light spot 4 of an appropriate size by a projection lens 2.
The target object 3 is irradiated with the light. The light spot 4 is imaged by the light receiving lens 5, and an image of the light spot 4 is formed on the light receiving surface of the light receiving element 6.

The light-receiving element 6 includes, for example, an optical position detector that outputs an optical signal proportional to the imaging position of the spot image toward both ends, and a light-receiving surface arranged at both ends of the optical position detector. and a photodetector that generates an electrical signal iA*ist' in response to an incident optical signal. Therefore, from the values of the electrical signals IA and 1B, the imaging position P of the optical spot image can be determined as follows.

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

The adder 7, the subtracter 8, and the divider 9 are circuits for implementing the calculation shown in equation (1) above based on the output signal iA+iB of the light receiving element 6. An output value P corresponding to the imaging position of the light spot image is obtained as the output.

On the other hand, if the distance to the target object 3 is 2 and the installation interval between the light emitting lens 2 and the light receiving lens 5 is L, then L is L-□ (2)
It can be obtained as tanθ. 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 light 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 to 2 is 1- to -P
It is obtained as (3). in this case,
K is a constant determined by each of the above fixed values, and is set by prior calculation or experiment. The converter 10 is
), inputs the position output P=i, and outputs the distance output λ.

[Problem that the invention seeks to solve]

Since the conventional non-contact distance measuring device is configured as described above, there is only one exit point for the measurement light beam, and when measuring the groove width of the target object or the distance between the target objects, there are multiple exit points. The distance measuring devices may be placed back to back, or the distance measuring devices may be arranged, for example, with a light emitting lens 2 and a light receiving lens 5.
It was necessary to measure by rotating the distance measuring device around a line O connecting the centers of . Furthermore, arranging a plurality of distance measuring devices back to back makes the entire configuration complicated and large. Additionally, rotating the distance measuring device requires a special rotary drive device, which is expensive.

This invention was made to solve the above-mentioned problems, and is a simple and inexpensive distance measurement system that can quickly measure the groove width of a target object or the distance between target objects in a fixed state. The purpose is to obtain equipment.

[Means for solving the problem] The distance measuring device according to the present invention has first
．． a second light entrance aperture and a first light entrance; The light from one light source is divided into a case provided with a second light exit opening facing the first one. a mirror for irradiating a target object as a light spot from a second light exit; The above-mentioned light spot image incident from the second light entrance is converted into the first light spot image. The first position imaged onto the second position detector. a second light-receiving lens; Each output signal from the second position detector is processed to obtain a distance output.

[Effect]

In this invention, the light from one light source is split into two directions by a mirror, so that measurement light beams are simultaneously emitted in opposite directions of 180 degrees to measure the groove width of the target object or the distance between the target objects.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In the figure, reference numeral 12 denotes a case, and there are first casings on the left and right walls. Second
The light entrance ports 13a, 13b and the first and second light exit ports 14
a and 14b are provided facing each other. 15 is a light source, 1
6 is a condenser lens that condenses the light from the light source 15; 17 is a lens that converts the light from the condenser lens 16 into parallel light; and 18 is a lens that directs a portion of the parallel light from the second light exit port 14a to the target object. 1
A half mirror 20 is configured to irradiate the target object 19b with the light transmitted through the half mirror 18 from the first light exit port 14b as a light spot Pb. The mirror 218.21b that reflects the light toward the first. The target object 198. which entered from the second light entrance ports 13a and 13b.
The first light spot images Pa and Pb are formed on 19b. The second light receiving lenses 22a and 22b output a signal proportional to the imaging position of the light spot image. The second light receiving elements 23a and 23b are respectively connected to the first light receiving elements 23a and 23b. Second light receiving element 2
2a and 22b to generate a distance output. The second distance computing unit is composed of, for example, the adder, subtracter, divider, and converter shown in FIG. 2 above. 24 is the first and second distance calculators 23a and 23b.
Distance output 1. .

This is an adder that adds l.

Next, the operation will be explained. The drawing shows the target object 19a,
This exemplifies the case where the distance between the objects 19b is measured, and the tip of the case 12 is disposed between the objects as shown.

A portion 25a of the light beam 25 emitted from the light source 15 and transmitted through the lens 16.17 is reflected by the half mirror 18, and is irradiated from the second light exit aperture 14a onto the target object 19a as a light spot (Pa).

The remaining light flux 25b that has passed through the half mirror 18 is reflected by the mirror 20, reaches the half mirror 18 again, is reflected by the half mirror 18, and is irradiated from the second light exit port 14b onto the target object 19b as a light spot PB. be done.

The light-receiving lenses 21a and 21b detect the light spots Pa and P.
b is imaged and formed on the light-receiving surfaces of the light-receiving elements 22a and 22b. For this reason, the light receiving element 22a.

From 22b, two electric signals 'A-1 and 'B-a, i A-b and iB are generated, respectively, according to the imaging position of the optical spot.
−.

are generated, and these electrical signals i□,・1B−,,1A−
b·i B−b are input to distance calculators 23a and 23b, respectively.

The distance calculators 23a and 23b produce distance outputs 1 . . . based on the input electrical signals. , lb is calculated and output, and this distance output 1. Ib is added by an adder 24 (t, +1.) to obtain the distance between the target objects 19a and 19b.

Further, when the distal end of the case 12 is inserted into the groove of the target object, the groove width can be measured by the same operation as described above.

〔Effect of the invention〕

As described above, according to the present invention, since the measurement light beam is emitted in two directions back to back and the measurement of two points can be performed at the same time, it is possible to quickly measure the distance between objects and the groove width. can.

Further, since the light from one light source is divided into two by using a half mirror to form measurement light beams in two directions, the distance measuring device can be constructed simply, compactly, and inexpensively.

[Brief explanation of drawings]

FIG. 1 is a block diagram of a distance measuring device showing an embodiment of the present invention, and FIG. 2 is a block diagram of a conventional distance measuring device. 12 is a case, 13a, 13b are entrance ports, 14a, 14
b is an exit port, 15 is a light source, 18 is a half mirror 119a
, 19b is a target object, 20 is a mirror, 21a, 21b are light receiving lenses, 22a, 22b are light receiving elements, 23a, 23
b is a distance calculator. In the drawings, the same members indicate the same or equivalent parts.

Claims (1)

[Claims] A case in which first and second light entrance ports and first and second light exit ports are provided facing each other on left and right walls; a half mirror that irradiates the target object as a light spot from a first light exit port; and a half mirror that directs the light transmitted through the half mirror to the half mirror so that the light that has passed through the half mirror is irradiated as a light spot from the second light exit port to the target object. a mirror that reflects the light, first and second light receiving lenses that form images of the light spot on the target object that have entered from the first and second light entrances; A distance measuring device comprising first and second light receiving elements that output proportional signals, and first and second distance calculators that process the output signals to generate a distance output.