JP2012237613A - Shape measuring device and shape measuring method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shape measuring device and a shape measuring method which measure a three-dimensional shape of an object using a plurality of reference planes constituting two-dimensional planes.SOLUTION: A shape measuring device 100 comprises: a first light source 20 which irradiates an object; a second light source 30 which irradiates the object; a camera 10 which has a plurality of pixels to image the object; a memory 70 which preliminarily stores a luminance ratio by pixel to three dimensional coordinate conversion table where the luminance ratios of the respective pixels obtained through the first light source as well as the second light source 30 are associated with heights of respective reference planes; and a control unit 50 which calculates the luminance ratio of each pixel of an image signal obtained by imaging the object and determines a three-dimensional coordinate of the object from values of the luminance ratio by referring to the luminance ratio by pixel to three dimensional coordinate conversion table.

Description

  The present invention relates to a shape measuring apparatus and a shape measuring method using a large number of reference planes that can perform shape measurement of an object without contact and with high accuracy.

  Conventionally, there is a technique for measuring the shape of an object based on a plurality of reference planes using a camera and a projector. For example, a plurality of reference planes having X and Y axis planes orthogonal to each other are set at predetermined intervals in the normal direction of the reference plane (that is, the Z axis direction perpendicular to the X and Y axis planes) and measured. The line of sight of the camera that images the point S on the object in order to determine the coordinates of the point S on the surface of the object by arranging the power object between the reference surfaces located at both ends of the plurality of reference surfaces And a point where each of the light rays from the projector passing through the point S on the object intersects the plurality of reference planes, and a line formed by the intersecting points on the line of sight of the camera and the intersecting point on the light rays from the projector A technique is known in which an intersection point with a straight line is obtained, two reference planes closest to the point are selected from the Z coordinate of the intersection point, and the shape of the object is measured using the two selected reference planes. (For example, refer to Patent Document 1).

  On the other hand, as another technique for measuring the shape of an object on the basis of a plurality of reference planes using a camera and a projector, a reference plane having X and Y axis planes is translated by a minute amount in the normal direction. By using a two-dimensional pattern or a spatial division pattern, which will be described later, for a plurality of reference planes, the pitch of the spatial division pattern projected onto the object is not affected even if the luminance distribution of the spatial division pattern projected onto the object is not cosine-like. 2. Description of the Related Art A shape measuring apparatus that can accurately measure a shape even at regular intervals is known (see, for example, Patent Document 2).

  Hereinafter, the technique of Patent Document 2 will be described in more detail. In the technique of Patent Document 2, for example, a liquid crystal display is used as a reference flat plate constituting the reference plane. Such a reference flat plate (liquid crystal display) is installed on the moving stage, and can be set at a predetermined interval in the normal direction of the reference plane (that is, the Z-axis direction perpendicular to the X and Y axis planes). .

  The reference flat plate (liquid crystal display) can display a predetermined two-dimensional pattern (for example, an equidistant grid). This two-dimensional pattern is used for associating pixels of an image captured by a camera with x and y coordinates on the X and Y axis planes.

  On the other hand, the projector can also project a spatial division pattern (for example, a grid-like light and shade pattern) in the X and Y axis directions while shifting the phase with respect to a reference plane at each position that translates in the Z axis direction of the moving stage. . However, this space division pattern is projected onto the object when the object to be measured is placed on the reference flat plate (liquid crystal display).

  The camera is installed in front of the reference plane, and is a first photographed image obtained by photographing a two-dimensional pattern in the X and Y axis directions formed on the reference plane at each position that translates in the Z axis direction of the moving stage. The first captured image signal corresponding to the second captured image signal corresponding to the second captured image obtained by capturing the space division pattern projected on the reference plane, and the object placed on the reference plate and projected onto the object A third captured image signal corresponding to the third captured image obtained by capturing the space division pattern is generated.

  A PC (Personal Computer) is provided as an analysis device that analyzes the shape of the object using the first captured image signal, the second captured image signal, and the third captured image signal. The analysis apparatus includes a calibration processing unit, a continuous photographing unit, a real time analysis unit, and a precision analysis unit.

  The calibration processing unit performs a calibration process in which a correspondence relationship between the phase of the projected grating and the three-dimensional coordinates to be measured is obtained for each pixel of the camera in advance. Specifically, the calibration processing unit uses the first captured image signal and the second captured image signal to acquire and associate the phase of the lattice displayed on the reference plane with the x coordinate and the y coordinate. As for the z coordinate, the position (the amount of movement of the reference flat plate) where the reference plane moves corresponds to the z coordinate. Accordingly, the calibration processing unit creates a table (hereinafter referred to as “phase / coordinate table”) in which the phase of the spatial division pattern and the three-dimensional spatial coordinates are associated one-to-one, and the created phase / coordinate table is stored in the memory. Save to.

  In order to measure the shape of the object in real time, the continuous shooting unit performs continuous shooting in synchronization with inputting as a projection image while shifting the phase of a space division pattern image (for example, a lattice image) in the projector, 3 is a functional unit that acquires captured image signals.

  The real-time analysis unit obtains the phase of the spatial division pattern pixel by pixel from the four consecutive frames of the third captured image signal continuously captured in synchronization with the phase shift of the spatial division pattern image. Using the phase / coordinate table created by the calibration processing unit, the x-coordinate or y-coordinate and the z-coordinate are obtained from the obtained phase, display image processing is performed, and the object is obtained using the x-coordinate, y-coordinate, and z-coordinate. Repeatedly displaying the shape data on the monitor.

  In addition to the real-time analysis unit, the precision analysis unit separates the spatial division pattern pixel by pixel from the four consecutive frames of the third captured image signal that are continuously captured in synchronization with the phase shift of the spatial division pattern image. And the object shape data is stored in the memory.

  As described above, in the techniques disclosed in Patent Document 1 and Patent Document 2 described above, since the shape of an object is measured based on a plurality of reference planes using a camera and a projector, projection by a projector is indispensable. is there.

On the other hand, a simpler technique for measuring the shape of an object without using a projector is conventionally known. As shown in FIG. 8, the shape of an object can be measured by photographing an object illuminated by _two light sources L ₁ and L ₂ (represented by point light sources 20 and 30, respectively) with a camera 10. . A reference flat plate 40 is placed perpendicular to the optical axis of the camera 10 and is used as a reference plane. On this reference plane, the X and Y axes orthogonal to each other are taken, and the Z axis is taken perpendicular to the X and Y axes. An object is placed on the reference flat plate 40, and the height of the point S on the object from the reference flat plate 40 is defined as z (variable).

When the illuminated object by a point light source is photographed by the camera 10, 2 of the distance between the value of the luminance I obtained from the captured image is proportional to the emission intensity I _S of the point light source, a point light source and the object Inversely proportional to the power. When the reflectance of the light of the object on the image plane by the camera 10 is r, the luminance of the reflected light is proportional to the reflectance r. Eventually, the luminance I of the image of the object photographed by the camera 10 can be expressed by Expression (1). Here, k is a proportional coefficient specific to the optical system including camera parameters such as sensitivity.

As shown in FIG. 8, it is assumed that a reference plate 40 is installed perpendicular to the optical axis of the camera 10, and light sources L ₁ and L ₂ are installed on the optical axis of the camera 10. The positions d ₁ and d ₂ having different distances from the point S on the object are the height z of the point S on the object from the reference plate 40 and the distances D ₁ and L ₂ from the reference plate 40 to the light sources L ₁ and L ₂ . Using D ₂ (D ₂ > D ₁ ), it can be expressed as shown in Formula (2) and Formula (3).

On the other hand, two light sources L ₁ and L ₂ at different positions d ₁ and d ₂ from the point S on the object are caused to emit light, and an image of the object at that time is taken by the camera 10 installed above. The light emission luminances of the light sources L ₁ and L ₂ are denoted as I _S1 and I _S2 , respectively. The two light sources L ₁ and L ₂ are turned on separately, and the luminances I ₁ and I _{2 at the} point S of each image photographed by the camera 10 can be expressed as in equations (4) and (5). it can.

  When Expression (2) and Expression (3) are substituted into Expression (4) and Expression (5), respectively, Expression (6) and Expression (7) are obtained.

By using the equations (6) and (7), the height z at the point S on the object can be obtained from the luminances I ₁ and I _{2 of} the captured image. That is, z is an unknown to be obtained. The distances D ₁ and D ₂ are known numbers determined from the dimensions of the optical system. The luminances I ₁ and I ₂ are luminance values measured by the camera 10. The coefficient k and the coefficient r are also unknown numbers, but it is not necessary to obtain them. If k · r is one unknown, the number of unknowns is two, k · r and z, and since there are two equations, they can be solved.

  On the other hand, when equation (6) is divided by equation (7), equation (8) is obtained.

  That is, Expression (8) is expressed as Expression (9).

  When this quadratic equation for z is solved, z can be obtained as shown in equation (10).

When the expression (10) is set as I ₁₂ = I ₁ / I ₂ and I _S12 = I _S1 / I _S2 , the expression (11) is obtained.

  When the quadratic equation of Equation (11) is solved, z is obtained as shown in Equation (12).

  In this way, the shape of an object can be measured by using two light sources and a camera without using a projector.

Japanese Patent No. 3446020 JP 2008-281491 A

  As described above, the techniques of Patent Literature 1 and Patent Literature 2 read the fine phase change generated from the spatial division pattern or the lattice pattern itself or the fine phase change generated from the spatial division pattern or the lattice pattern projected by the projector. Since it is a technique for measuring the shape of an object, high-accuracy measurement is possible, but there are drawbacks in that the apparatus configuration becomes large and the cost increases in that a projector is used.

  On the other hand, as described above, in the conventional technique of measuring the shape of an object by using two light sources and a camera without using a projector, the point to be measured on the object and the two light sources are arranged on the optical axis of the camera. It is basically on the same straight line. For this reason, when actually measuring the shape of the object, it is necessary to scan the camera and the two light sources in parallel with the reference plane (X and Y axis planes). In terms of providing a mechanism for maintaining the parallel scanning, there is a disadvantage that the apparatus configuration becomes large and a cost increases.

In the technique of measuring the shape of an object by using two light sources and a camera, assuming that the measured point on the object and the two light sources are not on the same straight line, the distance between the light source and the object is vertical. In addition to the position z, the function is a function of the positions x and y on the X- and Y-axis planes, and the functions expressed by the equations (10) and (12) are further complicated. In this case, the light emission luminances I _S1 and I _S2 of the light sources are required to be uniform with respect to all the irradiation directions of the two light sources. However, since the actual light source has uneven emission luminance depending on the direction, accurate measurement becomes difficult. Even when the calculation considering the unevenness of the light emission luminance can be performed, it becomes a complicated expression, and the calculation takes time.

That is, as shown in FIG. 9, consider a case where the positions of the _two light sources L ₁ and L ₂ and the point S on the object are not on the same straight line. Again, the brightness I of the captured image is proportional to the emission intensity I _S from the point light source is inversely proportional to the square of the distance d between the light source and the object. Here, it is assumed that there is no unevenness in the light emission luminance of the light source and the luminance distribution is uniform in all directions. In this case, the three-dimensional positions of the light sources L ₁ and L ₂ and the point S on the object are respectively (x _L1 , y _L1 , z _L1 ), (x _L2 , y _L2 , z _L2 ) and (x, y, z ) In this case, d in Expression (1) can be expressed as Expression (13) and Expression (14).

When Expression (13) and Expression (14) are substituted into Expression (2) and Expression (3), the luminances I ₁ and I _{2 at} the S point of each image captured by the camera 10 are expressed by Expression (15) and Expression It is expressed as (16).

Dividing equation (15) in equation (16), luminance ratio _{R 12} at the point S of the respective images taken by the camera 10 becomes equation (17). Here, R _S12 represented by the equation (18) is a luminance ratio of the two light sources at the point S, and is generally a function of location in consideration of unevenness of the light emission luminance of the light source.

Expression (17) is a quadratic equation regarding x, y, and z. Considering the line of sight of the pixel of the camera 10 viewing the point S on the photographed object, the line of sight is a straight line, and x and y are linear functions of z on this line of sight. When this linear function is substituted into equation (17), x and y are eliminated, but equation (17) becomes a complex quadratic equation of z. For this reason, it takes time to calculate this complicated expression. In addition, since the directions of the two light sources as viewed from the point S are different, if the emission luminance is uneven depending on the direction from the optical axis of the light source, I _S1 and I _S2 are not constant, and the calculation is very difficult. It becomes complicated. Therefore, the point S to be measured on the object and the positions of the _two light sources L ₁ and L ₂ are basically on the same straight line of the optical axis of the camera 10, and when actually measuring the shape of the object, In general, the camera 10 and the two light sources L ₁ and L ₂ are scanned in parallel to the reference plane (X and Y axis planes).

  As described above, the conventional techniques have a drawback that the apparatus configuration is large and a cost is increased.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a shape measuring device and a shape measuring method using a large number of reference surfaces that can perform object shape measurement with high accuracy without contact. And

  A shape measuring apparatus according to the present invention is a shape measuring apparatus that measures a three-dimensional shape of an object using a plurality of reference planes constituting a two-dimensional plane, the first light source for irradiating the object, and the first light source A second light source for illuminating an object, fixed in a three-dimensional spatial position different from the light source of the camera, a camera having a plurality of pixels for imaging the object, and coordinates and density of a two-dimensional plane are defined When each of the two-dimensional planes when the reference plate is translated at a predetermined interval in the normal direction of the reference plate is a reference plane in the height direction, the plurality of reference planes are Obtained by each of the first light source and the second light source from the luminance of each pixel of the image signal obtained by imaging each reference plane irradiated by each of the first light source and the second light source. The luminance ratio for each pixel is the height of each reference plane. Memory obtained by preliminarily storing a pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table for each associated pixel, and an object irradiated with each of the first light source and the second light source by the camera. The luminance ratio obtained by each of the first light source and the second light source is calculated from the luminance of each pixel of the image signal, and the pixel-specific luminance ratio / three-dimensional coordinate conversion table is calculated from the luminance ratio value. And a control unit that determines a three-dimensional shape of the object with reference to the control unit.

  In the shape measuring apparatus of the present invention, the first light source is composed of one or a plurality of LED light sources, the second light source is composed of one or a plurality of LED light sources, and the control unit includes the first light source. And a light source determination unit that performs dimming control by controlling lighting and extinguishing of the LED light sources constituting each of the light source and the second light source.

  In the shape measuring apparatus of the present invention, the control unit calculates an average of image signals obtained by imaging a plurality of times when calculating a luminance ratio obtained by each of the first light source and the second light source. A luminance ratio calculation unit for each pixel that calculates the luminance ratio from the value is provided.

  In the shape measuring apparatus of the present invention, the second light source has a higher light source luminance than the first light source, and the first light source and the second light source have substantially the same wavelength distribution. It is characterized by.

  In the shape measuring apparatus of the present invention, the control unit determines a three-dimensional shape of the object and determines brightness and color information of the object.

  Furthermore, the shape measurement method of the present invention is a shape measurement method for measuring the three-dimensional shape of an object using a plurality of reference planes constituting a two-dimensional plane, the first light source for irradiating the object, the first light source, A second light source for illuminating an object, a camera having a plurality of pixels for imaging the object, and a control unit, which are fixed at a three-dimensional spatial position different from the one light source, The processing procedure of the control unit is that the respective two-dimensional planes when the reference plate is translated at a predetermined interval in the normal direction of the reference plate where the coordinates and concentration of the two-dimensional plane are defined are When a reference plane is used, the luminance of each image signal obtained by imaging each reference plane irradiated by each of the first light source and the second light source by the camera with respect to the plurality of reference planes. From the first light And pre-holding, in a memory, a pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table for each pixel in which the luminance ratio for each pixel obtained by each of the second light sources is associated with the height of each reference plane; From the luminance for each pixel of the respective image signals obtained by imaging the object irradiated with each of the first light source and the second light source, the first light source and the second light source are obtained. Calculating a luminance ratio to be obtained, and determining a three-dimensional shape of the object by referring to the pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table from the value of the luminance ratio.

  According to the present invention, the shape of an object is canceled while canceling the influence of a light source position error, a target object position error, a light source luminance variation, a light source luminance distribution unevenness, a camera lens aberration, a camera lens stain, and the like. Measurement can be performed in a non-contact and highly accurate manner. Furthermore, at the time of object measurement, there is no need for a mechanism or a projector that translates the optical system (camera, first light source, and second light source) relative to the object, and the camera, first light source, and second light source are straightened. Since an object can be measured with a fixed optical system without being arranged on a line, the apparatus configuration can be made smaller than before, and the cost of the apparatus can be further reduced.

It is the schematic of the shape measuring device of 1st Embodiment by this invention. It is a block diagram of the control unit in the shape measuring device of a 1st embodiment by the present invention. It is a figure which shows the calibration processing flow of the control unit in the shape measuring apparatus of 1st Embodiment by this invention. It is a figure which shows the shape measurement process flow of the control unit in the shape measuring apparatus of 1st Embodiment by this invention. It is a figure which shows an example of the luminance ratio / height coordinate conversion table for converting from the luminance ratio to the height coordinate in the shape measuring apparatus according to the first embodiment of the present invention. It is a figure for demonstrating the concept of the luminance ratio and the three-dimensional coordinate conversion table classified by pixel in the shape measuring apparatus of 1st Embodiment by this invention converted into the three-dimensional coordinate. It is the schematic of the shape measuring apparatus of 2nd Embodiment by this invention. It is the schematic of the measurement principle in the conventional shape measuring apparatus. It is the schematic of the measurement principle in the shape measuring device which concerns on this invention. It is a figure which shows an example of the actual value of the conversion table converted into the height coordinate from the luminance ratio in the shape measuring apparatus which concerns on this invention.

  Hereinafter, a shape measuring apparatus according to each embodiment of the present invention will be described with reference to the drawings. The shape measuring device of the first embodiment is an example of measuring an object placed on a reference plate, and the shape measuring device of the second embodiment measures an object without using the reference plate when measuring the shape of the object. Will be described in order.

<First Embodiment>
〔Device configuration〕
FIG. 1 is a schematic diagram of a shape measuring apparatus according to a first embodiment of the present invention. The shape measuring apparatus 100 according to the present embodiment is an apparatus that measures a three-dimensional shape of an object using a plurality of reference planes that form a two-dimensional plane, and includes a camera 10 and light sources 20 and 30 (first light source L ₁ and A second light source L ₂ ), a control unit 50, and a memory 70. At the time of optical system calibration processing in the shape measuring apparatus 100, the optical system calibration processing is performed using a mechanism including the reference flat plate 40, the reference surface guide 80, and the motor 90. Note that the following description shows an example of a mechanism including the reference flat plate 40, the reference surface guide 80, and the motor 90 during the calibration process of the optical system. The monitor 60 is used to display measurement results as necessary.

The shape measuring apparatus 100 according to the present embodiment measures the shape of an object by photographing an object illuminated by _two light sources L ₁ and L ₂ (respectively represented by point light sources 20 and 30) with the camera 10. . On the other hand, in order to perform the calibration process of the optical system, a reference flat plate 40 is placed perpendicular to the optical axis of the camera 10, and this is used as a reference plane. On this reference plane, the X and Y axes orthogonal to each other are taken, and the Z axis is taken perpendicular to the X and Y axes. When an object is placed on the reference flat plate 40, the height of the point S on the object from the reference flat plate 40 is z (variable).

When the illuminated object by a point light source is photographed by the camera 10, 2 of the distance between the value of the luminance I obtained from the captured image is proportional to the emission intensity I _S of the point light source, a point light source and the object Inversely proportional to the power. When the reflectance of the light of the object on the image plane by the camera 10 is r, the luminance of the reflected light is proportional to the reflectance r.

The light source 20 (first light source L ₁ ) is a light source for irradiating an object, and has a light emission luminance I _S1 . The light source 20 (first light source L ₁ ) is preferably configured as a point light source composed of a plurality of LED light sources, and thus light control can be performed by a combination of turning on and off each LED light source. The first light source L ₁ is turned on and off, or dimming control is performed by a control signal (light source L ₁ control signal) from the control unit 50.

The light source 30 (second light source L ₂ ) is a light source for irradiating an object, which is fixed at a three-dimensional space position different from that of the first light source L _1, and has a light emission luminance I _S2 . The light source 30 (second light source L ₂ ) is preferably configured as a point light source composed of a plurality of LED light sources, and thus light control can be performed by a combination of turning on and off each LED light source. The light source 30 (second light source L ₂ ) is preferably configured so that the light emission luminance of the light source is higher than that of the first light source L ₁ (I _S2 > I _S1 ), more preferably It is desirable that the S / N ratio is made uniform by setting the luminance balance in consideration of being inversely proportional to the square of the distance to the reference flat plate 40 for the _first light source L ₁ and the second light source L ₂ . The second light source L ₂ is turned on and off, or dimming control is performed by a control signal (light source L ₂ control signal) from the control unit 50.

  The camera 10 has a plurality of pixels for imaging an object, and uses a camera using an imaging device such as a CCD sensor or a CMOS sensor. Such a camera may be either monochromatic imaging or multicolor imaging. For example, if a camera for a single color (no filter) is used, the sensitivity is improved. In the case of a camera having an RGB color filter, the RGB output value is set to luminance. Can be converted to a value. Imaging control of the camera 10 and acquisition of an image signal are performed by a control signal (camera control signal / image signal) from the control unit 50.

The reference flat plate 40 constitutes a two-dimensional plane with X and Y axes. The reference flat plate 40 may be used only during the calibration process. At the time of the calibration process, on the surface of the reference flat plate 40, a grid for measuring the x and y coordinates of the measurement result (a grid that is parallel to the X-axis direction and is equally spaced and parallel to the Y-axis direction) ) For example, a sheet having a black grid line drawn on a white surface, or a sheet having a constant density (for example, reflectivity is determined) for determining the luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel. Although there is a method of placing a known white sheet), in the following explanation, a sheet in which a grid line is drawn in black on a white surface (hereinafter, a sheet displaying a calibration image collectively) will be calibrated. An example of performing an optical system calibration process using a “sheet” will be described. If the error factor can be ignored, a liquid crystal display can be used. That is, it is possible to display a lattice image for making the scale of the x and y coordinates of the measurement result on the surface of the liquid crystal display constituting the reference flat plate 40 and shift the phase thereof.

The reference plane guide 80 moves the reference flat plate 40 at a predetermined interval of Δz (z = z ₀ , z ₁ , z ₂ ) in the normal direction (Z-axis direction) of the reference flat plate 40 in which the coordinates and density of the two-dimensional plane are defined. ,..., Z _n : n is an arbitrary integer, the resolution of the height distribution and the measurement range are determined by z _n , and z = z ₀ is, ie, the height coordinate of the object is 0) It is a guide rail for making each said two-dimensional plane when making it the reference plane of a height direction. The motor 90 is a drive source for translating the reference flat plate 40 along the reference plane guide 80. A known technique may be used for the mechanism, and further detailed description is omitted. Control for translating the reference flat plate 40 at a predetermined interval (z = z ₀ , z ₁ , z ₂ ,..., Z _n ) is performed by a control signal (reference surface position control signal) from the control unit 50. The

During the calibration process, the control unit 50 converts each two-dimensional plane when the reference flat plate 40 is translated at a predetermined interval in the normal direction (Z-axis direction) of the reference flat plate 40 to a reference plane in the height direction. when, for the plurality of reference planes, the luminance I of each pixel of each image signal obtained each reference surface that is irradiated by the first of each of the light source L ₁ and the second light source L ₂ by the camera 10 and imaging ₁ and I ₂ , a pixel in which the luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel obtained by each of the first light source L ₁ and the second light source L ₂ is associated with the height of each reference plane A luminance ratio / three-dimensional coordinate conversion table for each pixel is created and stored in the memory 70 in advance. Further, the control unit 50, when the shape measurement process, the luminance I of each pixel of each image signal obtained by the object irradiated by the first light source L ₁ and the second of each of the light source L ₂ by the camera 10 and imaging ₁ , I ₂ , the luminance ratio R ₁₂ obtained by each of the first light source L ₁ and the second light source L ₂ is calculated, and the pixel-specific luminance ratio and tertiary stored in the memory 70 in advance from the value of the luminance ratio The three-dimensional shape of the object is determined with reference to the original coordinate conversion table.

  The monitor 60 is a device for displaying the three-dimensional shape of the object determined by the control unit 50. Instead of displaying the measurement result on the monitor 60, an output from a printer may be used, or a recording medium may be used.

  Note that the control unit 50, the monitor 60, and the memory 70 of the present embodiment can be configured as a computer device 110. When the control unit 50 is configured as a computer, each computer of the control unit 50, which will be described later, is configured in the computer. A program for realizing the constituent elements is stored in the memory 70. A central processing unit (CPU) provided in the computer reads a program or processing data in which processing content for realizing the function of each component is described from the memory 70 as appropriate, and each component of the control unit 50 Can be realized on a computer. Here, it goes without saying that the function of each component may be realized by a part of hardware.

〔Controller unit〕
FIG. 2 is a block diagram of a control unit in the shape measuring apparatus according to the first embodiment of the present invention. The control unit 50 includes a calibration processing unit 510, a shape measurement unit 520, and a display control unit 530 that performs control to display a measurement result on the monitor 60.

  The calibration processing unit 510 includes a reference plane variable position setting unit 511, a light source determination unit 512, a camera imaging processing unit 513, a pixel-by-pixel luminance ratio calculation unit 514, a luminance ratio / height coordinate processing unit 515, and pixel-by-pixel A luminance ratio / three-dimensional coordinate conversion table generation unit 516;

The reference surface variable position setting unit 511 translates the reference flat plate 40 in the Z-axis direction along the reference surface guide 80 at a predetermined interval (z = z ₀ , z ₁ , z ₂ ,..., Z _n ). In addition, it is a functional unit that generates a reference surface position control signal for the motor 90. The reference surface variable position setting unit 511 obtains the motor control value and a predetermined interval (z = z ₀ , z ₁ , z ₂ ,..., Z _n ) if necessary for controlling the parallel movement. Control is performed by referring to the reference plane position data 710 associated in advance from the memory 70.

The light source determination unit 512 uses the camera 10 to generate a first light source L ₁ and a second light source L for a plurality of reference planes at predetermined intervals (z = z ₀ , z ₁ , z ₂ ,..., Z _n ). ₂ , the first light source L ₁ and the second light source L ₂ are switched on / off (including dimming control) and off in synchronization with the imaging of the camera 10. a light source L ₁ control signal and the light source L ₂ function unit for generating a control signal for performing. Source determination unit 512, the height from the first light source L ₁ or the second if necessary dimming control of the light source L _2, the first light source L ₁ and the second reference flat 40 of the light source L ₂ The light source dimming data 730 determined in advance according to (Z-axis direction) and the type of light source (such as a point light source composed of a plurality of LED light sources) is controlled by referring to the memory 70.

The camera imaging processing unit 513 sets the first light source L ₁ or the second light source L ₂ for a plurality of reference planes at predetermined intervals (z = z ₀ , z ₁ , z ₂ ,..., Z _n ). This is a functional unit that generates a camera control signal / image signal for acquiring an image signal by controlling imaging of the camera 10 in synchronization with lighting.

The luminance ratio calculation unit 514 for each pixel uses each two-dimensional plane when the reference flat plate 40 is translated at a predetermined interval in the normal direction (Z-axis direction) of the reference flat plate 40 as a reference plane in the height direction. when, the plurality of reference surfaces for (surface mounted with the calibration sheet), respectively obtained by each of the reference surface illuminated by the first light source L ₁ and the second of each of the light source L ₂ by the camera 10 and imaging The luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel obtained from each of the first light source L ₁ and the second light source L ₂ is calculated from the luminance I ₁ and I _{2 for} each pixel of the image signal. It is a functional part to do. The pixel-specific luminance ratio calculator 514, in calculating the first light source L ₁ and second respectively in the resulting luminance ratio of the light source L _2, the average value of the image signal obtained by a plurality of times imaging The luminance ratio can also be calculated.

The luminance ratio / height coordinate processing unit 515 converts the calculated luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel on the plurality of reference planes into height coordinates (z = z ₀ , z ₁ , z ₂ , .., Z _n ) is a functional unit that generates a luminance ratio / height coordinate conversion table associated with each other. The luminance ratio / height coordinate processing unit 515 can store the generated luminance ratio / height coordinate conversion table 740 (see FIG. 5) in the memory 70.

The pixel-specific luminance ratio / three-dimensional coordinate conversion table generation unit 516 generates a height coordinate (z coordinate) in the calculated luminance ratio / height coordinate conversion table 740 for each pixel on a plurality of reference planes, and a calibration image (or lattice). X obtained by capturing the image), the Y-axis plane (x, y-coordinate), x of each pixel in a plurality of reference surfaces relative to the luminance ratio R _12, y, pixel by the luminance ratio, the z-coordinate A three-dimensional coordinate conversion table is generated and stored in the memory 70. For example, as shown in FIG. 6, the luminance I ₁ and I ₂ by the uniform image portion on each reference plane can be obtained for each pixel, and the x and y coordinates by the grid line portion can be determined. Since the ratio R ₁₂ (= I ₁ / I ₂ ) is associated with the height coordinate, a pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table can be created. For pixels on the grid line (pixels straddling a plurality of x and y coordinate values), the x and y coordinates can be determined from the grid image. For pixels not on the grid line, the luminance value is calculated. Can be used. In FIG. 6, the grid lines are exemplarily represented with a size of one pixel or less, but the same processing can be performed even if the grid line portion is configured to be imaged across a plurality of pixels.

  The shape measurement unit 520 includes a reference plane initial position setting unit 521, a light source determination unit 522, a camera imaging processing unit 523, a pixel-by-pixel luminance ratio calculation unit 524, and a pixel-by-pixel three-dimensional coordinate determination processing unit 525.

The reference plane initial position setting unit 521 moves the reference flat plate 40 in the Z-axis direction along the reference plane guide 80 so as to be the initial position (z = z ₀ ). It is a functional unit that generates a control signal. The size of the object to be measured is in the range of z = z _{0 to} z _{n and is in} the range of x and y coordinates by the lattice image drawn on the reference plane. It is placed on the reference flat plate 40 at the position (z = z ₀ = 0). The reference plane initial position setting unit 521 determines the motor control value and a predetermined interval (z = z ₀ , z ₁ , z ₂ ,..., Z _n ) if necessary for the control of the parallel movement. Control is performed by referring to the reference plane position data 710 associated in advance from the memory 70. However, when the shape of the object is measured without using the reference flat plate 40, it is only necessary to place the object within the range of the plurality of reference surfaces (within the range of z = z _{0 to} z _n ). The processing of the position setting unit 521 is processing when an object is placed on the reference flat plate 40.

The light source determination unit 522 uses the camera 10 for each of the first light source L ₁ and the second light source L ₂ for an object shape that is within the range of the plurality of reference planes (z = z _{0 to} z _n ). in in order to image the illuminated object, respectively, the first light source L ₁ and the second lighting of the light source L ₂ (dimming control included) and the light source for switching off in synchronism with the imaging of the camera 10 L ₁ is a control signal and a light source L ₂ control signal function unit for generating a. Source determination unit 522, the height from the first light source L ₁ or the second if necessary dimming control of the light source L _2, the first light source L ₁ and the second reference flat 40 of the light source L ₂ The light source dimming data 730 determined in advance according to (Z-axis direction) and the type of light source (such as a point light source composed of a plurality of LED light sources) is controlled by referring to the memory 70.

Camera imaging processing unit 523, the object shape within the range of the plurality of reference surfaces (in the range of _{z = z} 0 _{~z n),} the first light source _{L 1} or the second light source _{L 2} of the lighting in the synchronization This is a functional unit that generates a camera control signal / image signal for controlling the imaging of the camera 10 and acquiring an image signal.

-Pixel luminance ratio calculator 524, the object shape within the range of the plurality of reference surfaces (in the range of _{z = z} 0 _{~z n),} the first light source _{L 1} and the second light source L by the camera 10 the object was irradiated with ₂ each from the luminance I _1, I ₂ for each pixel of each image signal obtained by imaging, for each pixel obtained by the first light source L ₁ and the second of each of the light source L ₂ This is a functional unit that calculates the luminance ratio R ₁₂ (= I ₁ / I ₂ ). The pixel-specific luminance ratio calculator 524, in calculating the first light source L ₁ and second respectively in the resulting luminance ratio of the light source L _2, the average value of the image signal obtained by a plurality of times imaging The luminance ratio can also be calculated.

Pixel-dimensional coordinate determination processing unit 525, a first light source L ₁ and previously held the pixel-in the memory 70 in the calibration process the value of the luminance ratio R ₁₂ obtained by the second respective light source L ₂ calculated The three-dimensional shape of the object is determined with reference to the luminance ratio / three-dimensional coordinate conversion table, the measurement result is stored in the memory 70, and the three-dimensional coordinates of the object are displayed on the monitor 60 in cooperation with the display control unit 530. It is a functional part to do.

[Device operation]
Next, the operation of the shape measuring apparatus according to the first embodiment of the present invention will be described.

(Calibration process)
FIG. 3 is a diagram showing a calibration processing flow of the control unit in the shape measuring apparatus according to the first embodiment of the present invention. In the following description of the operation, a case will be described in which a calibration sheet of one calibration image (consisting of a uniform image portion having a constant density and a lattice line portion) is used as a lattice image and a uniform image having a constant density.

First, the reference flat plate 40 is set to the initial position (z = z ₀ ) by the reference surface variable position setting unit 511 (step S1). A calibration sheet of a calibration image composed of a grid for making the scale of x and y coordinates and a uniform image of a constant density for the luminance ratio for each light source is set on the reference flat plate 40 (step S2).

Next, the first light source _{L 1} and turning off the second light source _{L 2} lit by the light source determining unit 512 (step S3). Subsequently, the camera imaging processing unit 513 images the reference flat plate 40, and holds the correspondence between the x and y coordinates of the grid and the pixels in the calibration image and the luminance value for each pixel as data (step S4).

Next, the light source determination unit 512 turns on the _second light source L2 and turns off the _first light source L1 (step S5). Subsequently, the camera imaging processing unit 513 captures the reference flat plate 40, and holds the correspondence between the x and y coordinates of the lattice in the calibration image and the pixels and the luminance value for each pixel as data (step S6). X grid at the calibration image, for correspondence between the y-coordinate and the pixel, the first light source L ₁ and may be used second data acquired only in one of the light source L _2, but a plurality of The accuracy can be improved by averaging the data.

Next, each image signal obtained by imaging the reference plane (a portion of a uniform image with a constant density) of the reference flat plate 40 set at the initial position (z = z ₀ = 0) by the pixel-by-pixel luminance ratio calculation unit 514. The luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel obtained by each of the first light source L ₁ and the second light source L ₂ is calculated from the luminances I ₁ and I ₂ for each pixel (step). S7). Subsequently, the luminance ratio / height coordinate processing unit 515 associates the calculated luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel on the reference plane with the height coordinate (step S 8), A separate luminance ratio / three-dimensional coordinate conversion table generation unit 516 generates a pixel-specific luminance ratio / three-dimensional coordinate conversion table on the reference plane of the reference plate 40 set to the initial position (z = z ₀ ) and stores it in the memory 70. (Step S9).

Steps S1 to S9 are repeatedly performed for a plurality of reference planes at predetermined intervals (z = z ₀ , z ₁ , z ₂ ,..., Z _n ), and the luminance ratio and three-dimensional coordinate conversion for each pixel on the plurality of reference planes is performed. A table is generated and stored in the memory 70 (steps S10 and S11).

  In this way, the shape measuring apparatus 100 generates a pixel-specific luminance ratio / three-dimensional coordinate conversion table for a plurality of reference planes and stores it in the memory 70 as a calibration process before measuring the shape of the object.

(Shape measurement process)
FIG. 4 is a diagram showing a shape measurement processing flow of the control unit in the shape measuring apparatus according to the first embodiment of the present invention.

First, the reference plane initial position setting unit 521 sets the reference flat plate 40 to the initial position (z = z ₀ ) (step S21). It is assumed that the object is placed on the reference flat plate 40 set at the initial position (z = z ₀ = 0). However, when the shape of the object is measured without using the reference flat plate 40, the object is placed within the range of the plurality of reference surfaces (in the range of z = z _{0 to} z _n ).

Next, the first light source _{L 1} and turning off the second light source _{L 2} lit by the light source determining unit 522 (step S22). Subsequently, an object placed on the reference flat plate 40 is imaged by the camera imaging processing unit 523, and the luminance value for each pixel is held as data (step S23).

Next, the light source determination unit 522 turns on the _second light source L2 and turns off the _first light source L1 (step S24). Subsequently, an object placed on the reference flat plate 40 is imaged by the camera imaging processing unit 523, and the luminance value for each pixel is held as data (step S25).

Next, the luminance I _{1 for} each pixel of each image signal obtained by imaging the object placed on the reference plate 40 set to the initial position (z = z ₀ = 0) by the pixel-specific luminance ratio calculation unit 524. , I ₂ , the luminance ratio R ₁₂ (= I ₁ / I ₂ ) for each pixel obtained from each of the first light source L ₁ and the second light source L ₂ is calculated (step S 26).

Subsequently, previously held in the memory 70 in the calibration process the value of the pixel-dimensional coordinates by the determination processing section 525, first light source L ₁ and the second luminance ratio R ₁₂ obtained in each of the light source L ₂ calculated Referring to the pixel-specific luminance ratio / three-dimensional coordinate conversion table (step S27), the three-dimensional shape of the object is determined (step S28), the measurement result is stored in the memory 70, and the display control unit 530 cooperates. Then, the three-dimensional coordinates of the object are displayed on the monitor 60 (step S29).

  In addition, it can comprise so that the result of averaging the measurement result of the three-dimensional coordinate of the object of multiple times may be displayed.

  In this manner, the shape measuring apparatus 100 can measure the shape of an object with a structure that is smaller in size and lower in cost than the conventional apparatus.

  Non-contact measurement of object shape while canceling effects of light source position error, target object position error, light source brightness variation, light source brightness distribution unevenness, camera lens aberration, camera lens dirt, etc. And it can be performed with high accuracy.

  Next, a shape measuring apparatus according to a second embodiment of the present invention will be described. Unlike the first embodiment, the shape measuring apparatus of the second embodiment is an example of measuring an object without using a reference flat plate.

Second Embodiment
〔Device configuration〕
FIG. 7 is a schematic view of a shape measuring apparatus according to the second embodiment of the present invention. Components similar to those in the first embodiment are denoted by the same reference numerals. The shape measuring apparatus 100 according to the present embodiment does not use the reference flat plate when measuring the shape of the object, and the three-dimensional object is placed within the range of the plurality of reference surfaces 40b (within the range of z = z _{0 to} z _n ). It is a device for measuring a shape, and includes a camera 10, light sources 20 and 30 (first light source L ₁ and second light source L ₂ ), a control unit 50, and a memory 70.

  Also in the second embodiment, as in the case of the first embodiment, as a calibration process before measuring the shape of the object, a luminance ratio / three-dimensional coordinate conversion table for each pixel on a plurality of reference planes is generated and stored in the memory 70. Keep it.

When measuring the three-dimensional shape of the object, the object shape within the range of the plurality of reference planes 40b (z = z _{0 to} z _n ) may be processed in the same manner as in the first embodiment. The control unit 50 performs luminance I _{1 for} each pixel of each image signal obtained by imaging an object irradiated with each of the first light source L ₁ and the second light source L ₂ by the camera 10 during the shape measurement process. , I ₂ , the luminance ratio R ₁₂ obtained by each of the first light source L ₁ and the second light source L ₂ is calculated, and the pixel-specific luminance ratio / three-dimensional value previously stored in the memory 70 from the value of the luminance ratio The three-dimensional shape of the object is determined with reference to the coordinate conversion table. Therefore, in 2nd Embodiment, the reference plane initial position setting part 521 is unnecessary among the function parts in the control unit 50 demonstrated in FIG.

  According to the second embodiment, since it is not necessary to use the reference flat plate 40 at the time of object measurement, for example, when measuring the three-dimensional shape of a human face, a handy type device configuration can be realized. It becomes like this.

  Hereinafter, with respect to the shape measurement of the object to be measured, the principle that the shape of the object can be measured from the pixel-by-pixel brightness ratio / three-dimensional coordinate conversion table on multiple reference planes by calculating the “brightness ratio” Explained.

  In the shape measuring apparatus 100 of the present invention, in order to be able to find the value of the height coordinate z of the object in the calculation of Expression (17), x, y based on the pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table. , Z-coordinate whole space tabulation method is used.

(Table of each pixel of the relationship between z and _{R 12)}
As a specific example of the equation (17), a calculation will be made with numerical values. From FIG. 9, for the pixel viewing the data on the line of sight represented by Expression (19), for example, the case of y = 0 will be calculated.

Here, _{z C} is the intersection of the line of sight and the camera optical axis, _{x R} is the reference plane and the intersection of the line of sight when the reference surface is the _{z C, z C} = _400mm, and x R = 10 mm.

The positions (x _L1 , y _L1 , z _L1 ), (x _L2 , y _L2 , z _L2 ) of the two light sources L ₁ and L ₂ and the luminance ratio R _S12 of each light source itself are set to the following values.
(X _L1 , y _L1 , z _L1 ) = (30 mm, 0 mm, 200 mm)
(X _L2 , y _L2 , z _L2 ) = (20 mm, 0 mm, 300 mm)
R _S12 = I _S1 / I _S2 = 0.5

When these values are substituted into equation (17), the relationship between R ₁₂ and z becomes equation (20), and when this relationship is graphed, FIG. 10 is obtained.

Thus, even if the first light source L ₁ and the second light source L ₂ is not the optical system on the optical axis of a camera 10 shown in FIG. 9, without scanning the optical system relative to the object, As shown in FIG. 10, z is a monovalent function of R ₁₂ for each pixel of the camera 10, and z is uniquely determined when the value of R ₁₂ is determined. That is, even in the case of the optical system as shown in FIG. 9, in order to accurately solve the expression (17) without scanning the optical system with respect to the object, the relationship between R ₁₂ and x, y, z is previously set. to previously obtain a pixel-luminance ratio, the three-dimensional coordinate transformation table for the pixels, and seen that pixel by referring to the pixel luminance ratio R _12-pixel luminance ratio, the three-dimensional coordinate transformation table from the upon shooting object The x, y and z coordinates of the point are obtained. Therefore, it is possible to determine the three-dimensional shape of an object by obtaining luminance ratio R ₁₂ of the pixels upon shooting object for all the pixels.

Note that the luminance ratio R _{S12 of the} light source can also be a function of each pixel, and this value can be generated as a pixel-specific luminance ratio / three-dimensional coordinate conversion table.

  Next, an example of a procedure for generating a pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table will be described.

(1) Creating a table of the relationship between x, y and z coordinates using a reference plane that moves in the z direction A grid that is parallel to the x direction and equally spaced in parallel to the x direction and a grid that is parallel to the y direction and equally spaced on the reference surface By drawing or displaying using a liquid crystal display or the like, the scale of the x and y coordinates can be obtained.

First, a reference plane in which the reference flat plate 40 is set at the origin of z (z = z ₀ = 0) is set, this image is taken by the camera 10, and the reference plane of the grid on which the pixel is viewed from the captured grid image is set. X coordinates and y coordinates are obtained, and the pixels are associated with the x and y coordinates. When obtaining the x coordinate and the y coordinate from the captured lattice image, the coordinate may be analyzed by, for example, a Fourier transform method or a phase shift method.

Next, a reference plane in which the reference flat plate 40 is moved in the vertical direction by a predetermined interval Δz is set, one or both of the light sources L ₁ and L ₂ are turned on, this image is taken by the camera 10, and the taken grid The x coordinate and the y coordinate on the reference plane of the lattice that the pixel is viewing are obtained with respect to the z position of the reference plane moved by a predetermined interval Δz from the image, and the pixel is associated with the x and y coordinates. In this way, while increasing the z coordinate of the reference plane by a constant interval Δz, the relationship between z and x, y in each pixel is generated as a table and stored in the memory 70. This operation is repeated until z is desired to be measured (z _{0 to} z _n ). Thereby, the correspondence of the x, y coordinate and the z coordinate in each pixel can be generated as a table.

(2) a table of the relationship between the luminance ratio R ₁₂ and z coordinates of each pixel then the display of the lattice of the reference surface, to change the reference plane uniform brightness of the white. A reference plane in which the reference flat plate 40 is set at the origin of z (z = z ₀ = 0) is set, the light sources L ₁ and L ₂ are sequentially turned on, and respective images are taken. And obtaining the luminance ratio R ₁₂ of the image at each pixel. Next, a reference plane in which the reference flat plate 40 is moved in the vertical direction by a fixed interval Δz is set, and the light sources L ₁ and L ₂ are sequentially turned on again to capture respective images. Then, a luminance ratio R ₁₂ of the image at each pixel. This operation is repeated while moving the reference flat plate 40 in the vertical direction by a constant interval Δz, and the relationship between the z coordinate and the luminance ratio R ₁₂ in each pixel is generated as a table and stored in the memory 70.

By combining the table generated in the above (1) and (2), generated when the luminance ratio R ₁₂ sought, x, y, a pixel-luminance ratio, the three-dimensional coordinate conversion table is required z-coordinate at each pixel can do. Once this pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table is created, it can be used forever as long as the configuration and arrangement of the optical system are not changed.

  Also, if you want to increase the resolution of the pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table, the pixel-specific luminance ratio with a large number of elements can be obtained by interpolation using data in the vicinity of each element in the pixel-specific luminance ratio / three-dimensional coordinate conversion table. The ratio / three-dimensional coordinate conversion table can be generated to improve the resolution.

  Next, an example of shape measurement using the pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table will be described.

A reference plane in which the reference flat plate 40 is placed at the origin of z (z = z ₀ = 0) is set, and the object is placed on the reference flat plate 40. At the time of shape measurement, the two light sources L ₁ and L ₂ are sequentially turned on to capture respective images. And obtaining the luminance ratio R ₁₂ of the image at each pixel. By comparing the intensity ratio R ₁₂ and pixel-luminance ratio, the three-dimensional coordinate conversion table, x, y, z coordinate it will be immediately apparent. As calculation can be obtained three-dimensional coordinates of the object by simply obtaining the luminance ratio R _12. Note that idea to create a table that can be determined luminance ratio from the value of the luminance by the luminance ratio light source L ₁ calculated also two of R _12, L ₂ are suitable to improve processing speed.

(Mapping of object brightness information and color information)
In the measurement method according to the present invention, since the luminances I ₁ and I ₂ of the captured image are so-called photographic images, three-dimensional CG image data can be generated if the luminance values are directly mapped to the obtained coordinates. it can.

(Cancellation of errors by using a total space table based on the pixel-specific luminance ratio and 3D coordinate conversion table)
When using the whole space tabulation method based on the brightness ratio by pixel and 3D coordinate conversion table, when the optical system at the time of creating the brightness ratio by pixel and 3D coordinate conversion table is the same as the optical system at the time of object measurement, Errors due to the influence of the optical system are basically canceled. Specifically, the positional error of the light source, the positional error of the target object, the variation in the luminance of the light source, the luminance distribution unevenness of the light source, the aberration of the camera lens, the contamination of the camera lens, etc. are cancelled. Further, the difference in reflectance (color) of the object to be measured is also deleted in principle.

(Cancellation of luminance variation in each pixel of the camera)
If the temporal variation in luminance of each pixel of the camera cannot be ignored, it is preferable to take an image a plurality of times, perform an average process, and use this average luminance value. Further, the object is measured in a dark room so that it is not affected by so-called external light other than the light from the _two light sources L ₁ and L ₂ , or the optical system including the object is made of a non-reflective cloth. Although it can be considered to be housed in a covered dark box, it is preferable to provide a black hood for preventing external light in order to enhance the portability of the apparatus.

In addition, since the influence by which the reflectance differs when the wavelengths of the _two light sources L ₁ and L ₂ are different cannot be removed by the method based on the pixel-specific luminance ratio / three-dimensional coordinate conversion table, the two light sources forming a pair The wavelength distributions of L ₁ and L ₂ are substantially the same wavelength distribution (the substantially same wavelength distribution is an error given as an imaging resolution of the camera 10 due to a difference between the wavelength distributions of the _two light sources L ₁ and L ₂ . It is preferable that the wavelength distribution is equal to or less than the resolution of the y and z coordinates. As the light source, a point light source is desirable, but a surface light source or a number of point light sources may be used. For example, the first light source L ₁ and the second light source L _2, the above pixel even constituted x, a plurality of different light sources in the y-coordinate as the first light source L ₁ and the second light source L _2, respectively Since it is tabulated like a separate luminance ratio / three-dimensional coordinate conversion table, no measurement problems occur. A light source using an LED chip is more suitable because it has a small area, high output, and little influence of luminance unevenness. Further, according to the LED light source, it is easy to adjust the light emission time, it is possible to cope with high speed, and the imaging processing of the camera 10 is easily synchronized. The LED light source has high luminous efficiency and energy saving.

Further, in order to increase the intensity resolution when shooting, the second light emission luminance of the light source L ₂ may be set higher than the first light emission luminance of the light source L _1, an image having a maximum luminance range which does not cause Sachireshon it is preferable to set the imaging parameters of the first light source L ₁ and the second light-emitting luminance and the camera 10 of the light source L ₂ so as to obtain. For this reason, methods such as changing the shooting time of the camera 10, changing the number of light sources using a plurality of LEDs, and changing the applied current of the LEDs are conceivable. In addition, the shooting time of the camera 10 may be determined so that an image shot with the _first light source L1 closer to the object has the highest luminance in a range where no saturation occurs.

  The present invention can reduce the size of the apparatus and reduce the cost, and thus is useful for applications in which object shape measurement is performed in a non-contact and highly accurate manner.

10 camera 20 first light source L1
30 Second light source L2
40 Reference Plate 50 Control Unit 60 Monitor 70 Memory 80 Reference Surface Guide 90 Motor 100 Shape Measuring Device

Claims (6)

A shape measuring device that measures a three-dimensional shape of an object using a plurality of reference planes constituting a two-dimensional plane,
A first light source for illuminating an object;
A second light source for illuminating an object, which is fixed at a different three-dimensional spatial position from the first light source;
A camera having a plurality of pixels for imaging an object;
When each two-dimensional plane when the reference plate is translated at a predetermined interval in the normal direction of the reference plate in which the coordinates and density of the two-dimensional plane are defined is used as a reference plane in the height direction, For a plurality of reference planes, the first light source is determined from the luminance of each pixel of each image signal obtained by imaging each reference plane irradiated with each of the first light source and the second light source by the camera. And a memory that holds in advance a pixel-by-pixel luminance ratio and a three-dimensional coordinate conversion table for each pixel in which the luminance ratio for each pixel obtained by each of the second light sources is associated with the height of each reference plane;
Each of the first light source and the second light source is determined from the luminance of each pixel of the image signal obtained by imaging the object irradiated with each of the first light source and the second light source by the camera. A control unit for calculating the luminance ratio obtained in step (a) and determining the three-dimensional shape of the object with reference to the pixel-specific luminance ratio / three-dimensional coordinate conversion table from the value of the luminance ratio;
A shape measuring device comprising:   2. The shape measuring apparatus according to claim 1, wherein the first light source includes one or more LED light sources, the second light source includes one or more LED light sources, and the control unit includes the first light source. A shape measuring apparatus comprising: a light source determining unit that performs dimming control by controlling turning on and off of an LED light source that constitutes each of one light source and the second light source.   The shape measurement apparatus according to claim 1, wherein the control unit obtains an image obtained by imaging a plurality of times when calculating a luminance ratio obtained by each of the first light source and the second light source. A shape measuring apparatus comprising a pixel-by-pixel luminance ratio calculating unit that calculates the luminance ratio from an average value of signals.   4. The shape measuring apparatus according to claim 1, wherein the second light source has a higher light source luminance than the first light source, and the first light source and the second light source are A shape measuring apparatus having substantially the same wavelength distribution.   5. The shape measuring apparatus according to claim 1, wherein the control unit determines a three-dimensional shape of the object and determines brightness and color information of the object. Shape measuring device. A shape measurement method for measuring a three-dimensional shape of an object using a plurality of reference planes constituting a two-dimensional plane,
A first light source for illuminating the object, a second light source for illuminating the object, which is fixed in a three-dimensional spatial position different from the first light source, and a plurality of pixels for imaging the object A camera and a control unit are provided,
The processing procedure of the control unit is as follows:
When each two-dimensional plane when the reference plate is translated at a predetermined interval in the normal direction of the reference plate in which the coordinates and density of the two-dimensional plane are defined is used as a reference plane in the height direction, For a plurality of reference planes, the first light source is determined from the luminance of each pixel of each image signal obtained by imaging each reference plane irradiated with each of the first light source and the second light source by the camera. And pre-holding, in a memory, a pixel-by-pixel luminance ratio / three-dimensional coordinate conversion table for each pixel in which the luminance ratio for each pixel obtained by each of the second light sources is associated with the height of each reference plane;
Each of the first light source and the second light source is determined from the luminance of each pixel of the image signal obtained by imaging the object irradiated with each of the first light source and the second light source by the camera. Calculating the luminance ratio obtained in step (b), determining the three-dimensional shape of the object by referring to the luminance ratio by pixel and the three-dimensional coordinate conversion table from the value of the luminance ratio;
A shape measuring method comprising: