JPH0483133A - Three-dimensional scanner - Google Patents

Abstract

PURPOSE:To allow non-contact form measurement and read of color information by conducting the scanning with a laser beam in which the optical axes of a plurality of laser beams having different wavelength are gathered to one and collecting the reflected scattered light from a material to be measured to a plurality of position detecting elements. CONSTITUTION:Laser beams 103 having different wavelengths from a laser oscillator 101 scan a material to be measured 104 by a laser scanner 102. The reflected lights 106 from a later radiating point 105 are collected to position detecting elements 112a-c through optical filters 109-111 by a light collecting lens 107 and half mirrors 108, respectively. The positions signals from them are subjected to the operation for color brightness data conversion of the radiating point 105 by color information detecting means 116a, b, 117 and outputted to an image memory 119. The above operation is successively repeated, whereby the color brightness information and three-dimensional distance information of the material to be measured 104 surface can be simultaneously obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a three-dimensional scanner that measures the amount of movement or shape of a target object in a non-contact manner.

BACKGROUND OF THE INVENTION Contact-type three-dimensional measuring instruments are often used as conventional three-dimensional object measuring devices, but since measurement takes time, three-dimensional measuring instruments that can perform non-contact and high-speed measurements have been developed.

As an example of a non-contact three-dimensional measuring device, JP-A-63-182
No. 503 proposes a non-contact three-dimensional measuring device using laser light.

FIG. 4 shows the basic configuration of the conventional example. 401 is a laser oscillator, 402 is a laser beam emitted from the laser oscillator 401, 403 is an object to be measured, and 404 is an object to be measured 4
03 is the TV camera that takes pictures, 405 is the TV camera 4
This is an A/D converter that A/D converts the video information of the object to be measured 403 photographed in 04.

406 is a noise removal circuit that removes noise components of A/D converted image information, 407 is an image memory, 408 is an address detector that finds the maximum value in the image information and detects the address information at that time, and 409 is a From among the image information stored in the image memory 407, the address detector 40
This is a barycenter coordinate calculator that extracts image information of a small area based on the address information detected in step 8 and calculates the barycenter coordinates.

410 is a CPU that controls the device, 411 is a CPU
A memory, 412 a CRT controller, and 413 a monitor.

The operation will be explained below.

A laser beam 402 emitted from a laser oscillator 4 is irradiated onto an object to be measured 403, and the object to be measured 403 is photographed by a television camera 404. The video shot by the television camera 404 is A/D converted by the A/D converter 405 and input to the noise removal circuit 406. Image information smaller than a predetermined value is converted to "0" and then stored in the image memory 407. is stored in

The image information from which noise has been removed is input to an address detector 408, which outputs the X and Y coordinates when the image information is at its maximum as an address. This address is the center of gravity coordinate calculator 40
9, the center of gravity coordinates are calculated based on the image information and address information of a small area around this value, and the distance to the object to be measured 403 is calculated using the coordinates of the center of gravity using the principle of triangulation shown in Fig. 5. The shape or amount of movement of the object to be measured 403 is determined by calculation.

That is, FIG. 5 shows the principle of triangulation, in which a laser beam 501 is irradiated to a point P502 on an object, and the reflected light 503 at that time is imaged by a television camera 504 or the like. At this time, by extracting the amount of movement of the image of the television camera 504 on the screen 505 caused by the unevenness of the surface of the object to be measured, the intersection angles θb and θd between the base line AB 506 and the reflected light 503 are determined. Three-dimensional coordinate information of the object surface can be obtained from these values, the irradiation angle of the laser beam 501, that is, the intersection angles θa and θC between the base line AB506 and the laser beam 501, and the length L of the base line AB506.

Problems to be Solved by the Invention However, when the shape of an object is measured and the object is inspected and recognized, color information on the surface of the object may be required. The conventional three-dimensional measuring instrument shown in FIG. 4 can measure the shape of an object without contact, but there is a problem in that it cannot read color information on the surface of the object. In view of the above problems, the purpose of the present invention is to
The aim is to measure the shape of an object without contact and at the same time read color information on the surface of the object.

Means for Solving the Problems In order to solve the above problems, the technical solution of the present invention is a laser beam that scans an object to be measured with a laser beam in which the optical axes of a plurality of laser beams each having a different wavelength are aligned into one. A scanning means condenses the scattered light obtained by being reflected from the object to be measured by scanning the laser beam onto a plurality of position detection elements using a condenser lens and a filter for transmitting each laser wavelength, and generates a photocurrent. A light amount detection means for outputting a signal, a distance calculation means for calculating distance information to the object to be measured based on the photocurrent signal from the light amount detection means, and a reflected light by the photocurrent signals from the plurality of light amount detection means. and color information detection means for outputting color information.

According to the above configuration, the present invention scans the object to be measured with a laser beam in which the optical axes of a plurality of laser beams having different wavelengths are aligned into one, and collects the scattered light obtained by reflection from the object to be measured. Using an optical lens and a transmission filter for each laser wavelength, the light is focused on multiple position detection elements to obtain a photocurrent signal, and the distance information to the object to be measured is calculated using the photocurrent signal. By outputting the color information of the reflected light using the photocurrent signal from the detection means, it is possible to measure the three-dimensional shape of the object to be measured without contact, and at the same time, it is possible to read the color information on the surface of the object to be measured. Since information and color information can be used in one-to-one correspondence for inspection and recognition of the object to be measured, this has a great effect on improving the accuracy of inspection and recognition.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIG.

FIG. 1 is a block diagram showing an embodiment of the three-dimensional scanner of the present invention. In FIG. 1, 101 is a laser oscillator that oscillates laser beams of three different wavelengths; 102
107 is a laser scanner that scans a laser beam 103 from a laser oscillator 101 onto an object to be measured 104; 107 is a condenser lens that focuses reflected light 106 from a laser irradiation point 105 on the object to be measured 104; and 108 is a half mirror. 109,11
0 and 111 are filters that transmit the respective laser wavelengths, 112ab and c are position detection elements, 113.114
and 115 are position detection elements 112 a * b , c
116a, b and 117 are color information detection means, 118 is a distance calculation means, 119 is an image memory,
120 is a synchronization signal generation circuit.

The operation will be explained below.

A laser scanner 102 scans an object to be measured 104 with laser beams 103 having three different wavelengths emitted from a laser oscillator 101 . The wavelengths of the three types of laser beams at this time are 636. Onm, 537.8nm and 4
It was set to 41.6 nm. Reflected light 106 from a laser irradiation point 105 on the object to be measured 104 is focused by a condenser lens 107 and a half mirror 108 onto position detection elements 112a, b, and c through optical filters 109, 110, and 111, respectively. Optical filters 109, 110 and 111 are filters that transmit wavelengths near the respective laser wavelengths.

Position signals 113, 114 and 115 from position detection elements 112a, b and c are output to color information detection means 116a, b and 117.

In the above embodiment, a PSD (position sensitive detector) is used as a position detection element.
The position of incidence on the PSD is determined by the calculation described below, taking advantage of the characteristic that the current flowing through the bipolar electrodes of the element is inversely proportional to the distance between each electrode. .

Next, the color information detection means 116a, b, 117,
II, I2., which are the respective position signals 113-115.
I3 and I4 perform calculations to convert the laser irradiation point 105 on the object to be measured 104 into color luminance data, and output the data to the image memory 119.

In the distance calculation means 118, the position signals 115 from the position detection element 112, If, I2, Ia, and I4
Then, calculation is performed to convert it into distance data to the laser irradiation point 105 on the object to be measured 104, and the data is output to the image memory 119.

By repeating the above operations and performing them in sequence, the object to be measured 1
04 surface color brightness information and three-dimensional distance information can be obtained simultaneously. This series of operations was synchronized using a synchronization signal from the synchronization signal generation circuit 120.

Next, the color information detection means 116 and 117 and the distance calculation means 118 will be explained in more detail using FIGS. 2 and 3.

FIG. 2 is a block diagram showing the detailed configuration of the color information detection means 116a. The color information detection means 116a receives the position signal 113 from the two-dimensional position detection element 112a.
f, I2. I3 and I4 are connected to A/D converter 205~
At 208, each is converted into a digital signal. Here, I
I and I2 indicate position information in the X direction of the two-dimensional position detection element, and I3 and I4 indicate position information in the X direction of the two-dimensional position detection element. The position signals ■l and I2 are added in an adder circuit 209, the position signals I3 and I4 are added in an adder circuit 210, the output values of the adder circuits 209 and 210 are further added in an adder circuit 211, and the luminance data (L
l) Obtain 212. The brightness data (Ll) 212 is based on the filter 1 that transmits wavelengths near the laser wavelength of 636.0 nm.
09, and similarly, green and blue color information can be obtained from brightness data obtained from other laser wavelengths.

FIG. 3 is a block diagram showing the detailed configuration of the color information detection means 117. The color information detection means 117 detects Il, which is the position signal 115 from the two-dimensional position detection element 112C,
I2, Ia and I4 are connected to A/D converter 305
~308, each is converted into a digital signal.

Here, I3 and I2 indicate the position information of the two-dimensional position detection element in the X direction, and I3 and I2 indicate the position information of the two-dimensional position detection element in the X direction.

An addition circuit 309 adds the position signals 1 and I2, and a subtraction circuit 310 subtracts them. Similarly, position signals I3 and I4 are added by an adder circuit 311, and a subtracter circuit 31
Subtract by 2. The output values of the adder circuit 309 and the adder circuit 311 are further added in the adder circuit 313 to obtain luminance data (
I3) 314 and the signal (Il+I2) 316 from the adder circuit 309°311. (I3 + I4
) 317 and signals from subtraction circuits 310 and 312 (engine 2
-11) 315. (I4-13) 318 is output to the distance calculation means 118.

Then, in the distance calculation means 118, the color information detection means 11
Signals from 7 (Il+I2), (I3+I4).

(1) from (I2-II) and (I4-I3)
An operation that calculates the position on the two-dimensional position detection element using the formula and formula (2), and converts it into distance data to the laser irradiation point on the object to be measured based on the principle of triangulation shown in Figure 5. and output to image memory.

Note that K1 and K2 are coefficients that are not used for normalization.

As the position (x, y) on the position detection element, 111 (
I2-If)/(If + I2)...(1)
Y=2・(I4-Ia)/(Ia+I4)
...(2) In this example, a laser oscillator that oscillates laser beams with three different wavelengths was used, but a laser oscillator that oscillates laser beams with one type of wavelength, and each oscillator with a different wavelength. A similar effect can be obtained by providing a plurality of laser beams and aligning the optical axes of the respective laser beams with one using a reflecting mirror.

Effects of the Invention As is clear from the above embodiments, the invention is obtained by aligning the optical axes of multiple laser beams with different wavelengths, scanning the laser beams over the object to be measured, and reflecting them from the object to be measured. The scattered light is focused on multiple position detection elements using a condenser lens and a transmission filter for each laser wavelength, and a photocurrent signal is obtained.
By calculating the distance information to the object to be measured using the photocurrent signal, and at the same time outputting the color information of the reflected light using the photocurrent signals from the multiple light amount detection means, the three-dimensional shape of the object to be measured can be determined without contact. At the same time as measurement, it is also possible to read the color information on the surface of the object to be measured, and the one-to-one correspondence between distance information and color information can be used for inspection and recognition of the object. This has a great effect on improving recognition accuracy.

[Brief explanation of the drawing]

FIG. 1 is a block wiring diagram of a three-dimensional scanner according to an embodiment of the present invention, FIGS. 2 and 3 are detailed block wiring diagrams of the same essential parts, and FIG. 4 is a block wiring diagram of a conventional three-dimensional scanner. FIG. 5 is a geometric layout diagram showing the principle of triangulation. 101... Laser oscillator, 102... Laser scanner, 104... Measured object, 107-... Condenser lens,
108... Half mirror 109-111... Optical filter, 112... Position detection element, 116-117...
... Color information detection means, 118 ... Distance calculation means, 11
9... Image memory. Name of agent: Patent attorney Shigetaka Awano and one other person;

Claims (1)

[Claims] A laser beam scanning means that scans an object to be measured with a laser beam that is made by aligning the optical axes of a plurality of laser beams each having a different wavelength, and scattering that is obtained by being reflected from the object to be measured by scanning the laser beam. A light amount detection means for condensing light onto a plurality of position detection elements using a condensing lens and a transmission filter for each laser wavelength and outputting a photocurrent signal; A three-dimensional scanner comprising distance calculation means for calculating distance information to an object, and color information detection means for outputting color information of reflected light based on photocurrent signals from the plurality of light amount detection means.