JPH04122809A - Shape recognition device - Google Patents

Abstract

PURPOSE:To obtain a high-speed and a compact device by aligning a plurality of linear PSD arrays along a longer direction of a reflection light as a light- receiving element for receiving reflection light by an object to be inspected. CONSTITUTION:Light from a light source 1 is scanned two-dimensionally on a surface of an object to be inspected in a direction crossing illumination light by a scanning means 3 through a projection optical system 2 and then a reflection light is received by a light-receiving element 5. A linear PSD array, where a plurality of linear PSDs1 - sn are aligned in a direction cutting a light image, is used as the element 5, signal processing circuits c1 - cn are provided for each linear PSDsi, and two-dimensional shape in one light-cutting image is identified simultaneously with reception light-cutting image. The result of two-dimensional scanning is taken into a memory 11 as a data corresponding to a distance to a surface of the object to be inspected and a three-dimensional shape can be identified based on this data, thus enabling a shape to be recognized at high speed with a compact device.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shape recognition device that recognizes the three-dimensional shape of an object in a non-contact manner.

[Prior Art] Many proposals have been made in the past for non-contact recognition of the three-dimensional shape of an object, and some of these techniques have been realized and put into practical use.

One of the most widely used sensors is a spot light scanning type distance sensor that applies the so-called triangulation principle.

This distance sensor is the 16th [! As shown in FIG. 1, light from a light source 1 such as a semiconductor laser is condensed onto an object to be inspected by a projection optical system 2° such as a condensing lens, and a scanning means 3 comprising a reflecting mirror or the like. There is a distance sensor that scans the above light in one direction and focuses the reflected light from the object onto a light receiving element 5' such as a PSD using a light receiving optical system 4 such as a condensing lens. The condensing position of the reflected light on the light receiving element 5 is read in synchronization with , the distance to the point where the spot light is irradiated is calculated, and the two-dimensional shape on the scanning line is thereby determined. Then, as shown in FIG. 17(a) or (b), the distance sensor A° or the object to be inspected I was trying to find the three-dimensional shape of the surface.

In addition, as shown in FIG. 18, another method is adopted in which the scanning means 3 is composed of two scanning sections 3a and 3b, and one scanning section 3a is arranged in a direction perpendicular to the scanning direction of the other scanning section 3a. As the scanning unit 3b performs scanning, the distance sensor A°
There is also one that is capable of scanning a certain range two-dimensionally without moving either the object X to be inspected or the object X to be inspected.

[Problems to be Solved by the Invention] However, all of the above-mentioned shape recognition devices have the following problems. That is, in the above-described shape recognition device, since the object to be inspected X is scanned point by point, the scanning speed becomes slow, and there is a problem in that the shape cannot be recognized at high speed. Moreover, in order to scan the light two-dimensionally on the object surface, two scanning mechanisms are always required, which makes it difficult to miniaturize.

The present invention has been made in view of the above points, and its purpose is to be able to recognize shapes at high speed,
Another object of the present invention is to provide a compact shape recognition device.

(Means for solving the s! problem) In order to achieve the above object, the present invention includes a planar light generating means that generates planar light, and a light projecting optical system that condenses the light linearly onto the object to be inspected. The light-receiving element comprises a scanning means for scanning plane light in a direction perpendicular to the irradiation light, and a light-receiving element for receiving reflected light from an object to be inspected that is linearly focused through a light-receiving optical system, and the light-receiving element includes: A one-dimensional PSD array is used in which a plurality of one-dimensional PSDs are arranged in a plurality of rows along the longitudinal direction of the reflected light, with each one-dimensional PSD oriented perpendicular to the longitudinal direction of the reflected light.

In addition, in order to reduce the number of components of the signal processing section, the above 1.
One-dimensional PS of each photodetector consisting of a dimensional PSD array
D is divided into multiple groups, and 1 for each group.
A signal processor 1 that includes a selector that selectively outputs the output of the dimensional PSD in a time-sharing manner, and also performs signal processing on the output of each selector to calculate distance data for each one-dimensional PSD! A circuit may also be provided.

In addition, if the presence of an invalid light-receiving area of a one-dimensional PSD affects shape recognition accuracy, a plurality of one-dimensional PSDs constituting the one-dimensional PSD array may be arranged in a staggered manner in two vertical stages. , the invalid light-receiving areas at both ends of the one-dimensional PSD, which are arranged diagonally above and below, are arranged in a vertically overlapping manner,
It is possible to reduce the apparent ineffective light receiving area.

Furthermore, a light-receiving element consisting of a one-dimensional PSD array is moved by a minute displacement in the longitudinal direction of the focused reflected light, and a signal processing circuit performs signal processing at each moving position to calculate the two-dimensional shape at each moving position. If determined, it is possible to improve the resolution in the longitudinal direction of the reflected light that is focused.

Furthermore, a light-receiving element made of one one-dimensional PSD or a plurality of one-dimensional PSDs arranged in a row at a predetermined interval is provided, and the light-receiving element is scanned within a condensing plane of a light-receiving optical system to perform scanning. If the distance data is calculated for each step, it becomes possible to obtain the light reception output in any range in the longitudinal direction of the condensed reflected light with any resolution.

[Function] By configuring as described above, the present invention enables linear reflected light to be simultaneously received by a light receiving element consisting of a one-dimensional PSD array, and furthermore, the scanning means is one [
IIJ, it is only necessary to scan in the direction perpendicular to the irradiated light, thereby reducing the time required for scanning and making it possible to recognize the shape at high speed.

Moreover, by making it sufficient for the scanning means to scan in only one direction, the scanning means can be made smaller without affecting the shape of the apparatus.

[Example 1] An embodiment of the present invention is shown in FIGS. 1 to 5.

As shown in FIG. 1, the shape recognition device of this embodiment includes a light source 1 such as a semiconductor laser, and a cylindrical lens that converts the light from the light source 1 into planar light (hereinafter referred to as planar light). A light projecting optical system 2 like this, and this light projecting optical system 2
scanning means 3 for scanning the object to be inspected with plane light transmitted through the The surface of the object to be inspected is scanned by the scanning means 3 in a direction orthogonal to the irradiated light as shown by the arrow in the figure, and the surface of the object to be inspected is scanned by the scanning means 3 consisting of one scanning mechanism. This allows for two-dimensional scanning.

Then, the light receiving element 5 receives the reflected light from the object to be inspected of the irradiation light emitted from the light projection system at a predetermined angle α with respect to the light projection direction.

Here, the image obtained by receiving light with the light-receiving element 5 as described above is generally called a light section image, and is widely known for obtaining the three-dimensional shape of the object to be inspected.
This type of method is used to identify three-dimensional shapes,
For example, a CCD camera or the like was used as the light receiving element 5.

However, in order to input one light section image in a CCD camera, at least the ITV scanning period (#16
ee) is required, and therefore there is a problem in that it takes time to perform two-dimensional scanning.

Therefore, in this embodiment, as shown in FIG. 2, a one-dimensional PSD array in which a plurality of one-dimensional PSDs+-sn are arranged in the direction of the optically sectioned image is used as the light-receiving element 5. As shown in FIG. 4, signal processing circuits c1 to Cfl are provided for each one-dimensional PSDsi, so that the two-dimensional shape in one optically sectioned image can be identified at the same time as the optically sectioned image is received. . Here, as shown in FIG. 3, the signal processing circuit cr includes I/V converters 6 + and 62 that respectively convert the outputs yL and Vi2, which are current signals of the one-dimensional PSDsj, into voltage signals. Amplifiers 71, 7 that amplify the voltage signals, respectively! , an adder 8 that adds the amplified output, a subtracter 9 that subtracts the amplified output, and a divider 10 that divides the addition output and the subtraction output. Then, the data data 1 to data n as the outputs of each signal processing circuit (1 to cn) having the above configuration are stored in a memory 11 that stores nXm data. Here, the number of columns m of the memory is the number of scanning steps. , and the number of rows 11 is made to match the number of one-dimensional PSDs. Therefore, for example, j
Signal processing circuit CI"-Cn in the second scanning step
data data 1 to data n 4. t Stored in the jth column, then dat when scanning advances one step
a1 to datan are stored in the j+1st column. The results of the two-dimensional scanning in this way are taken into the memory 11 as data corresponding to the distance to the surface of the target object, and the three-dimensional shape can be identified based on the data stored in the memory 11. I can do it.

FIG. 5 shows a configuration diagram when a control section is added to a detection system consisting of a light emitting and receiving system.The three-dimensional shape based on the data in the memory 11 is obtained by the arithmetic processing of the CPU 12, and the scanning means 3 is controlled by the CPU 12. The rotation is controlled by a scanning step controller 13 operating at the base.

[Example 2] Other embodiments of the present invention are shown in FIGS. 6 and 7.

In the case of the above-mentioned embodiment, as shown in FIG.
+~cn are provided, and each P S Ds+ ~ nail has two outputs (ff+++Vz+, yi+,...JI+
+...L+)(Y+zJ2t+Yko2...J12
+...ye2), and each signal processing circuit C1 to C
n requires an I/V converter 61, 62 and an amplifier 7 + , 72 for each output, so that the signal outside II!
The number of components of IT paths C1 to cn increases. Therefore, in this embodiment, the number of components of the signal processing circuits C2 to cn is reduced.

Specifically, as shown in FIG. 6, one-dimensional PSDs, -
Divide sn into groups of n pieces each, provide a signal processing circuit C1=Cv for each group, and output one-dimensional P S Ds, ~sr+ through selectors ^S, ~^S5 consisting of analog switches, etc. is selectively input to the signal processing circuits (1 to Ck. Here, the switching control of the output selection means ^S, to ^Sk is performed by the CPUI 2. However, in this case, the time required for signal processing is Although there is a slight increase in the amount, it is not large enough to cause a problem.

[Example 3] FIGS. 8 to 10 show still other embodiments of the present invention, a one-dimensional PSD in which a plurality of one-dimensional PSDS, ~sn of each of the above-mentioned embodiments are arranged in the direction of the optically sectioned image. In the array, there are ineffective light receiving areas (dead zones) (A) indicated by diagonal lines in FIG. existence is 3
In some cases, the influence on the detection accuracy of dimensional shapes cannot be ignored. Therefore, in this embodiment, the 911th! As shown in l, one-dimensional PSDs, = sn are arranged in a staggered manner in two stages, upper and lower, and corresponding one-dimensional PSs are arranged diagonally in upper and lower positions.
The invalid light-receiving areas (A) of Ds and =sn are arranged so as to be vertically overlapped. Then, the optically sectioned images are converted into upper and lower one-dimensional PSs.
A branching optical system 4' is used which branches into two upper and lower optical paths so as to irradiate DS, to sn. In this way, the influence of the width of the invalid light receiving area (a) can be approximately halved.

[Example 4] Figures 11 and 12 are still another example of the present invention, and in this example, the light receiving element 5 made of the one-dimensional PSD array is moved by a minute displacement in the direction of the light section image. Meanwhile, at each position, signal processing circuits c1 to C11 perform signal processing to obtain a two-dimensional shape in one optically sectioned image,
By repeating this process, the resolution in the direction of the optically sectioned image is increased.

Specifically, as shown in FIG. 11, for example, one-dimensional PSD
When s,=sn are arranged at pitch l, the signal sampling is repeated by moving 0 times with a displacement of 1/n.In this way, the resolution in the direction of the optically sectioned image can be increased by n times. I can do it.

In order to realize this, as shown in FIG. 12, vibrations are applied to the light receiving element 5 using a vibration element 14, such as a piezo element, which vibrates at a constant period with a minute amplitude, and the vibration of the vibration element 14 is Signal processing port Net in synchronization with the cycle
It is sufficient to repeat the signal processing at ~Cn, however,
In this case, the timing controller 15 is used to control the overall timing.

[Embodiment 5] Still another embodiment of the present invention is shown in FIGS. 13 to 155ff. In this embodiment, as shown in FIG. 13, for example, one
(The scanning state is shown in FIG. 14), so that a light sectioned image in an arbitrary range can be detected with an arbitrary resolution. In addition, at this time, as shown in FIG.
Dimensional PSD (Figure 15 f) jl combination g:: Ha4
II f) P S D s + −s 4 ) The scanning may be performed on the condensing surface of the light receiving optical system 4.

[Effects of the Invention] As described above, the present invention includes a planar light generating means that generates planar light, and a planar light generating means that generates planar light in a direction perpendicular to the irradiation light linearly focused on the object to be inspected by the projection optical system. It consists of a scanning means for scanning light, and a light-receiving element for receiving reflected light from an object to be inspected that is focused linearly through a light-receiving optical system. Since the method uses a plurality of one-dimensional PSD arrays arranged perpendicularly to the longitudinal direction of the reflected light, the linear reflected light can be simultaneously received by a light receiving element consisting of a plurality of one-dimensional PSD arrays. In addition, the scanning means only needs to scan the surface light in a direction perpendicular to the linear irradiation light, so scanning does not take much time and it is possible to recognize the shape at high speed. Furthermore, since the scanning means only needs to scan in one direction, the device can be made smaller without affecting its shape.

Further, the one-dimensional PSD of each of the light-receiving elements comprising the one-dimensional PSD array is divided into groups, and a selector is provided for selectively outputting the output of the one-dimensional PSD in a time-sharing manner for each group, By providing a signal processing circuit that processes the output of each selector and calculates distance data for each one-dimensional PSD, the signal processing circuit can be shared by multiple one-dimensional PSDs, and for this reason, the components of the signal processing section can be can be reduced.

Furthermore, if the existence of an invalid light-receiving area of a one-dimensional PSD affects the shape recognition accuracy, the plurality of one-dimensional PSDs constituting the one-dimensional PSD array may be arranged in a staggered manner in two vertical stages. By arranging the invalid light-receiving areas at both ends of the one-dimensional PSD, which are arranged diagonally above and below, one above the other, it is possible to reduce the apparent invalid light-receiving area. The existence of the shape no longer affects shape recognition accuracy.

Furthermore, a light-receiving element consisting of a one-dimensional PSD array is moved by a minute displacement in the longitudinal direction of the focused reflected light, and a signal processing circuit performs signal processing at each moving position to determine the value at each moving position. If a two-dimensional shape is determined, it becomes possible to detect the shape in a fine range, and it becomes possible to improve the resolution in the longitudinal direction of the collected reflected light.

The scanning step includes a light-receiving element consisting of one one-dimensional PSD or a plurality of one-dimensional PSDs arranged in a row at a predetermined interval, and the light-receiving element is scanned within the light-converging plane of the light-receiving optical system. By calculating the distance data for each time, it becomes possible to obtain the light reception output in any range in the longitudinal direction of the focused reflected light with any resolution.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing the configuration of a detection system according to an embodiment of the present invention, Fig. 2 is an explanatory diagram showing a one-dimensional PSD array used as a light receiving element, and Fig. 3 is an explanatory diagram showing the output signals of each one-dimensional PSD. Block diagram showing the configuration of a signal processing circuit that performs processing, No. 4
5 is an explanatory diagram showing the overall configuration of the signal processing section, FIG. 5 is an explanatory diagram showing the overall configuration of the same as above, FIG. 6 is an explanatory diagram showing the configuration of the signal processing section of another embodiment, and FIG. 1 is an explanatory diagram showing the overall configuration of the same as above, FIG. 8 is an explanatory diagram showing the arrangement state of a one-dimensional PSD array, and 9th f! I is an explanatory diagram showing the arrangement state of a one-dimensional PSD array in yet another embodiment, FIG. 10 is an explanatory diagram showing the configuration of the same detection system, and FIG. 11 is an explanatory diagram showing the operation control of the light receiving element in yet another embodiment. Explanatory diagram of method 5. Figure 12 is an explanatory diagram showing the overall configuration of the same as above, and 13th t! I is an explanatory diagram showing the overall configuration of another embodiment, FIG. 14 is an explanatory diagram of the scanning method of the same one-dimensional PSD, Section 15 is an explanatory diagram of the case where a plurality of one-dimensional PSDs are scanned, and FIG. Figure 16 is a configuration diagram of a conventional detection system, No. 1711! l (a), (b)
18 is an explanatory diagram of a scanning method for detecting a three-dimensional shape according to the same method as above, and FIG. 18 is a configuration diagram of still another conventional detection system. 1 is a light source, 2 is a light projecting optical system, 3 is a scanning means, 4 is a light receiving optical system, 5 is a light receiving element, 51 to S11 are one-dimensional PSDs, c
, ~cn are signal processing circuits. Agent Patent Attorney Ishi 1) Chief 7 Figure 2 Figure 6 Figure 7 Figure 11 Figure 12 Figure 13 Figure 14 Figure 15 Figure 16 Figure 18 Self-motivated to write procedural amendments) November 1, 1990 Japan Patent Application No. 245349 of 1990 2, name of the invention shape recognition device 3, relationship with the case of the person making the amendment Patent Applicant Address 1048 Kadoma, Kadoma City, Osaka Prefecture Name (58
3) Matsushita Electric Works Co., Ltd. Representative: Toshio Miyoshi 4, Agent postal code: 530 Address: 1-12-17 Oval, Kita-ku, Osaka (Oval Building 5th floor) -m-8 Contents of amendment No. 9 in the attached drawing Correct the figure as shown in the attached sheet.

Claims (5)

[Claims] (1) A planar light generating means that generates planar light, a scanning device that scans the planar light in a direction perpendicular to the irradiation light linearly focused on the object to be inspected by the projecting optical system, and a light receiving optical system. and a light receiving element that receives reflected light from the object to be inspected that is linearly focused through the system, and as the light receiving element,
A plurality of one-dimensional PSDs are arranged in a row along the longitudinal direction of the reflected light, with each one-dimensional PSD oriented perpendicular to the longitudinal direction of the reflected light.
A shape recognition device characterized by using an SD array. (2) The one-dimensional PSD of each of the light receiving elements comprising the one-dimensional PSD array is divided into groups, and a selector is provided for selectively outputting the output of the one-dimensional PSD in a time-sharing manner for each group. 2. The shape recognition apparatus according to claim 1, further comprising a signal processing circuit for signal processing the outputs of the respective selectors to calculate distance data for each one-dimensional PSD. (3) A plurality of one-dimensional PSDs constituting the one-dimensional PSD array are arranged in a staggered manner in two stages vertically, and the invalid light receiving areas at both ends of the one-dimensional PSDs arranged diagonally up and down are arranged vertically. The shape recognition device according to claim 1, characterized in that the shape recognition device is arranged in an overlapping manner. (4) A light-receiving element consisting of a one-dimensional PSD array is moved by a minute displacement in the longitudinal direction of the focused reflected light, and a signal processing circuit performs signal processing at each moving position to obtain a two-dimensional shape at each moving position. 2. The shape recognition device according to claim 1, wherein the shape recognition device calculates the following. (5) A light-receiving element consisting of one one-dimensional PSD or a plurality of one-dimensional PSDs arranged in a row at a predetermined interval is provided, and the light-receiving element is scanned within the condensing plane of the light-receiving optical system to perform scanning. A shape recognition device characterized by calculating distance data for each step.