JPH11148806A - Reader for three-dimensional body and its susrface image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately make respective pieces of information correspond by reducing a read dead angle when obtaining distance information and luminance information on a body to be measured. SOLUTION: This is a reader for a three-dimensional body and its surface image which has a slit light projection part 20 for irradiating the body 11 to be measured with slit light and an image pickup part 30 for picking up an image of the surface of the object body and is equipped with a rotating mechanism (rotary part 12) moving the image pickup part 30 around the object body 11 relatively. The image pickup part 30 receives visible light reflected light from the front part of the object body 11 by a 1st image pickup element to read a luminance image of the surface and receives slit light reflected light of the slit light irradiating the same area with the front part of the object body 11 to measure the surface shape (distance image), thus obtaining image data of high quality by reading the respective pieces of image information at the same time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reading apparatus for obtaining data by imaging the surface of an object to be measured in a personal computer, an engineering workstation, or the like. The present invention relates to a three-dimensional object that can simultaneously read luminance information such as density information and color information on a surface, and a reading device for a surface image of the three-dimensional object.

[0002]

2. Description of the Related Art Conventionally, in order to obtain a three-dimensional shape (distance image) of an object to be measured, measurement is generally performed using a slit projection method. In the slit light projection method, as shown in FIG. 10, light from a light projector 1 is converted into slit light 3 through a slit 2, the slit light 3 is irradiated on an object 4 to be measured, and the reflected light is used as a distance image detection camera. 5 (see JP-A-1-195303).

When measuring the three-dimensional shape of the object 4 from one direction, as shown in FIG. 11, the direction of irradiation of the slit light 3 from the slit light source is controlled by controlling the rotation of the support 5 (or Adjustment by controlling the angle of a mirror (not shown) arranged in the slit light source), changing the irradiation position of the slit light on the object to be measured, sequentially scanning, and measuring the object that can irradiate the slit light The distance image of the entire object portion is read by the distance image detection camera 5.

Accordingly, as a device for simultaneously reading the three-dimensional shape (distance image) of the object to be measured and the luminance information (luminance image) of the surface of the object, a slit light source for measuring the three-dimensional shape, a camera for detecting a distance image, This can be realized by a configuration including a light source and an image pickup device for obtaining luminance information. In this case, a light source (not shown) for obtaining a luminance image
Are separately arranged, the direction of the optical axis of an image pickup device (not shown) is fixed, the whole object to be measured is imaged in one frame, and then mapping with the distance image is performed, so that the luminance at each pixel is obtained. Images and range images can be obtained.

In the above-mentioned reading apparatus, different light sources are used as a light source for obtaining a luminance image and a light source for obtaining a distance image. For example, a semiconductor laser light is used as a light source for slit light, and a visible light is used as a light source for luminance image. Used. Therefore, in order to obtain each image, it is necessary to switch the light source and image the object to be measured.

[0006]

According to the above reading apparatus, when the irradiation position of the slit light on the object to be measured is changed and the irradiation is performed sequentially, the slit light is scanned from one end to the other end of the object to be measured. The optical path length from the slit light source to the irradiation position on the measurement object differs depending on the positional relationship between the left and right of the measurement object. Therefore, there is a problem in measurement accuracy that an error in the position in the depth direction to be measured differs depending on the irradiation position of the object to be measured. As a result, there is a problem in that the measurement accuracy decreases as the distance from the center part approaches the both ends at the left and right positions in the measurement area in the three-dimensional shape measurement.

[0007] Further, since the positions of the slit light source and the camera for detecting a distance image are fixed, blind spots are easily generated depending on the shape of the object to be measured, and there is a high possibility that an unmeasurable portion is generated. That is, the larger the angle of the optical axis of the optical system with respect to the normal on the measurement point where the slit light of the measured object is irradiated, the more unmeasurable parts are generated depending on the shape of the measured object. was there.

Further, in a portion where measurement is impossible or in a portion where a step is generated in the depth direction, information on the density of the image on the side cannot be obtained, and it is necessary to perform interpolation by analogy with surrounding image information. Will be different from the shade information.

On the other hand, the luminance image (two-dimensional image) obtained by the image pickup device is obtained by projecting the object to be measured on a two-dimensional plane, and cannot accurately correspond to the unevenness of the distance image. Depending on the shape of the object, there is a problem that the position of the distance image and the position of the luminance image are shifted, resulting in unnatural image information (a distance image with a luminance image).

Furthermore, it is necessary to switch the light source between the time of obtaining the distance image and the time of obtaining the luminance image, and this causes an increase in the processing time of the entire reading.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. In a reading apparatus for reading distance information of an object to be measured and luminance information on the surface of the object to be measured, the reading apparatus obtains distance information and luminance information of the object to be measured. It is an object of the present invention to provide a three-dimensional object capable of reducing blind spots and accurately associating each piece of information by reading each piece of information at the same time, and a reading device for a surface image of the three-dimensional object.

[0012]

In order to achieve the above object, the present invention comprises a slit light projecting section for irradiating slit light to an object to be measured, and an imaging section for imaging the surface of the object to be measured. A three-dimensional object provided with a rotation mechanism in which the imaging unit relatively moves around the object to be measured, and a device for reading a surface image of the three-dimensional object, characterized by including the following configuration. The imaging unit includes an image reading unit and a three-dimensional object reading unit. The image reading means receives the reflected visible light from the front part of the object to be measured by the first imaging element and reads the luminance information on the surface. The three-dimensional object reading means measures the surface shape by receiving the slit light reflected light of the slit light applied to the same area as the front part of the measured object by the second image sensor.

[0013] The imaging unit relatively moves around the object to be measured when the imaging unit is fixed and the object to be measured is arranged on a rotatable stage. This means a case where the imaging unit is rotated with respect to the object to be measured by rotating the imaging unit while rotating around the object while fixing the object to be measured.

According to a second aspect of the present invention, in the first aspect, a visible light transmitting filter is provided on the light receiving surface side of the first image pickup device.

According to a third aspect of the present invention, in the apparatus for reading a three-dimensional object and its surface image, the first imaging element of the imaging section is disposed so as to face a front portion of the object to be measured. It is characterized by becoming.

According to the present invention, since the imaging section is provided with a rotation mechanism that relatively rotates around the object to be measured, the imaging position of the object to be measured with respect to the imaging section is sequentially rotated by a predetermined angle. By reading later, luminance information and distance information on the entire periphery of the measured object can be obtained. Since the imaging unit detects the visible light reflected light and the slit light reflected light from the front part of the measured object, respectively, it is possible to simultaneously read the luminance information and the distance information of the same area of the measured object.

Further, by providing a visible light transmitting filter on the light receiving surface side of the first image pickup device for reading a luminance image in the image pickup section, it is possible to transmit and detect only visible light.

Further, by arranging the first image pickup device so as to face the front part of the object to be measured, the position of the first image pickup element is closest to the front part of the object to be measured, and the visible light reflected light Can be shortened.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a three-dimensional object and an apparatus for reading a surface image of the three-dimensional object according to the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of the reading device, FIG. 2 is a plan view showing the entire reading device, and FIG. 3 is a layout explanatory diagram showing the positional relationship between the imaging section of the reading device and the object to be measured.

This three-dimensional object and its surface image reading apparatus simultaneously and simultaneously read a luminance image (shade information and color information) and a distance image (three-dimensional shape) of an object to be measured, as shown in FIG. As described above, the measurement unit 10 on which the measurement object 11 is placed, the slit light projection unit 20 that irradiates the measurement object 11 with slit light, the visible light reflected light and the slit light reflection light from the measurement object 11 Imaging unit 30 that receives and detects light
Measurement target section 10, slit light projecting section 20, imaging section 30
And a control unit 40 for performing the above control.

The part to be measured 10 is constituted by providing a circular stage (rotating part) 12 on which a to-be-measured object 11 is mounted on one end of a support plate 14 (FIG. 2). The stage (rotating unit) 12 includes a rotating mechanism that rotates about its center 15 as an axis. The rotation of the stage (rotating unit) 12 by the rotating mechanism rotates intermittently by a predetermined fixed angle. Is controlled by the rotation control unit 13 as described above.

The slit light projecting section 20 includes a slit light generating section 21 for generating slit light, a galvano mirror 22a for changing the traveling direction of the slit light, and the object 11 to be measured.
And a mirror control unit 23 that controls the angle of each galvanomirror. The slit light generator 21 includes a semiconductor laser that emits laser light, and a cylindrical lens that converts the laser light into slit light that is elongated in the vertical direction. Further, a slit light may be obtained by using a liquid crystal shutter for the semiconductor laser.

Galvanometer mirrors 22a and 22b (FIG. 3)
The optical axis of an image pickup device (drive processing circuit) 321 for reading a luminance image of a 2D image pickup unit 32 (to be described later) is controlled by making the rotation angle controllable by the mirror control unit 23. (A position where the object and the object 11 intersect) with slit light, and the slit light reflected light is made incident on an image sensor (drive processing circuit) 311 for reading a distance image of the 3D shape measuring unit 31. .

The image pickup section 30 includes a 2D image pickup section (image reading means) 32 for reading a luminance image of an object to be measured, and a 3D shape measuring section (three-dimensional object reading means) 31 for reading a distance image.
It is composed of The positional relationship between the measured object section 10 and the imaging section 30 will be described with reference to FIG. 2. The rectangular imaging section 30 has the other end side with respect to the stage (rotating section) 12 provided on one end side of the support plate 14. Installed on the support plate 14 of
The light emitting surface and the light receiving surface located on the long side of the imaging unit 30 are arranged so as to face the measured object 11 placed on the stage (rotating unit) 12. Therefore, when the stage (rotating unit) 12 rotates, the imaging unit 30 moves the object 1 to be measured.
1 will relatively move.

3D shape measuring unit (three-dimensional object reading means) 3
Reference numeral 1 denotes an imaging device (drive processing circuit) 311 for receiving slit light reflected light from the measured object 11, an optical imaging system 312 for guiding the slit light reflected light to the imaging device (drive processing circuit) 311, It comprises a slit light detection circuit 313 that receives an image signal from the image sensor 311 and detects the position of slit light in the image, and a 3D coordinate calculation circuit 314 that calculates the position of each pixel of the image signal in the depth direction. I have. The imaging element (drive processing circuit) 311 uses a two-dimensional imaging element, and its imaging region has several pixels in the horizontal direction and is equal to the width of the slit light in the vertical direction so as to correspond to the irradiation range of the slit light. It is a rectangular area having pixels.

The control unit 40 includes an image memory 41 for storing distance image data from the 3D coordinate calculation circuit 314, an image memory 42 for storing luminance image data from an image pickup device (drive processing circuit) 321, and a microcomputer 43. It is composed of The microcomputer 43 associates the distance image data and the luminance image data from the image memories 41 and 42 for each pixel, and outputs an image signal as distance information on which luminance information is mapped. The microcomputer 43 also controls the rotation control unit 1 of the measured object unit 10.
3, a rotation control signal for intermittent rotation, an angle control signal for controlling the angle of the galvanometer mirror 22 to the mirror control unit 23 of the slit light projecting unit 20, and a 2D image to the drive processing circuit 321 of the 2D image capturing unit 32. A reading control signal, a 3D image reading control signal to the drive processing circuit 311 of the 3D shape measuring unit 31, a slit light detecting signal to the slit light detecting circuit 313,
The information on the set angle of the galvanometer mirror 22 is output to the 3D coordinate calculation circuit 314.

In the slit light detection circuit 313 described above,
A highlight portion in the binarized image signal is extracted, and the position of the slit light in the image of the imaging region is determined by thinning processing. In the 3D coordinate calculation circuit 314,
Position of slit light in image and microcomputer 43
The position of each pixel in the depth direction is determined from the set angles of the galvanometer mirrors 22a and 22b controlled by the control. The position in the depth direction is calculated for pixels at regular intervals in the imaging region from the top to the bottom of the slit light.

Therefore, the slit light emitted from the slit light generator is reflected by the galvanomirror whose rotation angle is controlled, and irradiates the front area (the same area as the area where the luminance image is read) of the measured object. The reflected light is reflected by the galvanomirror on the light receiving side and is received by the image sensor, so that the distance image in the front area can be read. Since the slit light is light having a width in the vertical direction as described above,
The imaging area of the imaging element (drive processing circuit) 311 is also a rectangular area for reading a plurality of images.

The 2D image pickup section 32 includes an image pickup device (drive processing circuit) 321 such as a CCD camera for receiving visible light reflected light from the object 11 to be measured, and an image pickup device (drive processing circuit) 321 for receiving visible light reflected light. Imaging system 322 for guiding to
, A visible light transmitting filter (laser light removing filter) 323 disposed on the light receiving surface side of the image sensor 321, and a light source 324 for emitting illumination light. Light source 324
May be omitted by using light of natural light or indoor light. Therefore, the visible image from the light source 324 illuminates the front portion of the measurement target 11, and the image sensor 321 receives the reflected visible light, so that the luminance image of the front portion can be read. The image pickup device 321 uses a two-dimensional image pickup device, and its image pickup area is a 3D shape measurement unit 3
In order to read the same imaging region as 1, a rectangular region (a region having several pixels in the horizontal direction and pixels having a width equal to the width of the slit light in the vertical direction) corresponding to the irradiation range of the slit light is used.

Next, the reading operation of the luminance image and the distance image of the object to be measured by the reading device will be described with reference to the flowchart of FIG. First, the DUT 1
1 is placed on a stage (rotating section) 12 of a support plate 14 (FIG. 2). In this state, the image sensor 321 and the visible light transmitting filter 323 of the 2D image capturing unit 32 of the image capturing unit 30 mounted on the support plate 14 are located facing the front of the measured object 11 (FIG. 3). Stage (rotating part) 12
Is controlled to rotate intermittently at a small angle, and the imaging unit 30 is positioned at the front position of the measured object 11.

When the start of reading is selected, the rotating unit rotates by a predetermined angle and stops (step 401), and receives a 2D image reading control signal and a 3D image reading signal from the microcomputer 43 to capture a 2D image. Part 21 and 3D
Reading by the shape measuring unit 31 is started at the same time. That is, in the 3D shape measuring unit 31, the slit light is emitted from the slit light generating unit 21 (step 40).
2) The light reflected from the galvanomirror 22a on the irradiation side whose rotation angle is controlled by the microcomputer 43 is irradiated with slit light on the front part of the object 11 to be measured.

The slit light reflected by the front part is reflected by the galvanomirror 22b on the light receiving side, guided to the image pickup device (drive processing circuit) 311 via the optical image forming system 312, and converted into an image of the slit light. Reading is performed (step 403). The microcomputer controls the mirror control unit 23 that controls the galvanometer mirrors 22a and 22b so that the slit light irradiates the front part of the measured object 11 and the slit light reflected light is guided to the image sensor (drive processing circuit) 311. 43 outputs a control signal.

The image data read by the image pickup device (drive processing circuit) 311 is converted into a digital image by an A / D converter in the drive processing circuit, and the slit light detection circuit 31
3 is sent. In the slit light detection circuit 313, 2
A highlight portion is extracted from the digitized image data, and the position of the slit light in the image is determined by thinning processing. For example, as shown in FIG. 5, when the image data (two-dimensional image read by the image sensor) by the slit light in the image capturing area extends over a plurality of pixels (shaded area), the One pixel is determined as the position of the slit light, and image data like a solid line is obtained (thinning processing).

Subsequently, the 3D coordinate calculation circuit 314 calculates the position in the depth direction corresponding to one pixel from the position of the slit light in the image and the information on the set angles of the galvanometer mirrors 22a and 22b input from the microcomputer 43. It is calculated (step 404). That is, galvanometer mirror 2
The horizontal and vertical distances l and m between the galvanometer mirrors in FIG. 6 and the angles α and β between the horizontal direction and the horizontal direction are obtained from the set angles 2a and 22b and the imaging position of the slit light in the slit light detection circuit 313 in FIG. . Therefore, the distance z in the depth direction to be obtained from the geometric shape in the figure can be calculated by the following equation (Equation 1). The position in the depth direction is calculated for all the pixels in the slit light imaging area, and the result is stored as a distance image in the image memory 4.
1 and stored.

[0034]

[Formula 1] z = (ltanα · tanβ−mtanβ) /
(Tanα + tanβ)

On the other hand, in the 2D image pickup section 32, the light source 324 is turned on (step 405), and the object 11 is irradiated with illumination light at the same position (front part) as the slit light. When the reflected light of the illumination light passes through the visible light transmitting filter 323, the laser wavelength component is removed, and only the visible light reflected light passes through the optical imaging system 322 of the 2D image capturing unit 32 and the imaging device ( (A drive processing circuit) 321 to read a luminance image (step 40).
6). The luminance image detected by the imaging element (drive processing circuit) 321 is A / D-converted in the drive processing circuit, and is output to the image memory 42 as a luminance image of a digital image and stored. The image area to be stored is a rectangular area corresponding to the width of the slit light (the same area as the imaging area of the slit light).

Then, in the microcomputer 43, the distance image data and the luminance image data from the image memories 41 and 42 are associated with each other for each pixel, and the three-dimensional position (x, y, z) of the surface image is Brightness information (R, G,
Image information is output as distance information to which the luminance information having B) is mapped (step 407).

Next, it is determined whether or not the stage (rotating unit) 12 has made one round (step 408). If less than one round, the stage (rotating unit) 1 is rotated by a predetermined angle.
2 rotates, and the measurement by the 3D shape measuring unit 31 and the reading by the 2D image capturing unit 32 described above are repeated.
When the measurement and reading of one round of the surface of the measurement object 11 are completed, a connection process is performed for the image information (distance information to which the luminance information is mapped) of each of the measured and read imaging regions (rectangular regions). (Step 40
9), the image information on the entire surface of the measured object 11 is obtained, and the process ends.

FIGS. 7 and 8 show another embodiment of the reading apparatus. That is, while the above-described reading apparatus has a configuration in which the imaging unit 30 is fixed and the measurement target 11 is disposed on a rotatable stage (rotating unit) 12, this reading apparatus The imaging unit 30 is configured to be fixed and move while rotating around it. 7 and 8, parts having the same configuration as those of the reading apparatus shown in FIGS. 1 to 3 are denoted by the same reference numerals, description thereof will be omitted, and parts having different configurations will be described.

In this reading apparatus, the stage 12 has a rotation mechanism 50 for rotating the support 14 around the rotation shaft 15 without rotating the stage 12. This rotation mechanism 5
Numeral 0 indicates that the support section (rotating section) 14 is rotated with respect to the stage 12 by the rotation control section 51 which receives a control signal from the microcomputer 43. Therefore, the luminance information and the distance information are detected while the slit light projecting unit 20 and the imaging unit 30 rotate around the measured object 11 placed on the stage 12.

FIG. 9 shows another embodiment of the reading apparatus, in which the optical path of the slit light from the slit light projecting section and the illumination light from the light source are partially shared. Portions having the same configuration as in FIG. 3 are denoted by the same reference numerals. That is, the light projecting device 60 has a light source 61 that emits slit light and illumination light having the same optical axis. And is reflected. The reflected light is split into slit light reflected light and illumination light reflected light by the half mirror 70 (the slit light reflected light is reflected and the illumination light reflected light is transmitted), and the illumination light reflected light passes through the visible light transmission filter 323. The reflected light becomes visible light reflected light, and is guided to the image sensor 321 of the 2D image pickup unit 32. The slit light reflected light is reflected by the galvanometer mirror 22b to change the optical path.
It is guided to the image sensor 311 of the 3D shape measuring unit 31. 3D
The processing of the image data in the shape measuring unit 31 and the 2D image capturing unit 32 is the same as that of the reading apparatus shown in FIGS.

[0041]

According to the present invention, the luminance information on the entire periphery of the object to be measured is read by sequentially rotating and moving the image pickup position of the object to be measured with respect to the image pickup unit by a predetermined angle with the rotation mechanism. And distance information can be obtained,
The blind spot of the imaging unit can be reduced, and reading with high positional accuracy in the depth direction can be performed.

Since the imaging section reads the respective reflected lights of the visible light and the slit light applied to the front portion of the object to be measured, it can simultaneously read the luminance information and the distance information of the same area of the object to be measured. The distance image and the luminance image can be accurately associated with each other, and the processing speed can be increased by the simultaneous reading processing.

Further, the first image pickup device and the front portion of the object to be measured are disposed so as to face each other, the position of the first image pickup device is closest to the front portion of the object to be measured, and the optical path length of visible light Can be shortened, and highly accurate image information can be obtained.

Therefore, according to the reading apparatus of the present invention,
High-quality image data in which the luminance image and the distance image are associated with each other can be obtained.

[Brief description of the drawings]

FIG. 1 is a block diagram showing an example of an embodiment of a reading device according to the present invention.

FIG. 2 is an explanatory view illustrating the appearance of the reading device of FIG. 2;

FIG. 3 is a layout explanatory diagram illustrating a positional relationship between an object to be measured, an imaging unit, and a slit light projecting unit in the reading device.

FIG. 4 is a flowchart for explaining a flow of a reading operation in the reading device.

FIG. 5 is a partial explanatory diagram of an imaging region showing a part of an example of image data detected by an imaging element of a 3D shape measurement unit of the reading device.

FIG. 6 is an optical ray explanatory diagram for explaining calculation of a depth of a pixel from a set angle of a galvanomirror.

FIG. 7 is a block diagram showing another example of the embodiment of the reading device.

FIG. 8 is an external view of the reading device shown in FIG.

FIG. 9 is a layout explanatory diagram illustrating a positional relationship between an object to be measured, an imaging unit, and a slit light projecting unit in another example of the embodiment of the reading device.

FIG. 10 is a diagram illustrating the principle of a reading apparatus that measures a distance image by a slit projection method.

FIG. 11 is a layout diagram illustrating a positional relationship between an object to be measured, an imaging unit, and an image sensor by a conventional reading apparatus.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Measurement object part, 11 ... Measurement object, 12 ... Stage (rotation part), 13 ... Rotation control part, 14 ... Support,
Reference numeral 20: slit light projecting section, 21: slit light generating section, 22a, 22b: galvano mirror, 23: mirror control section, 30: imaging section, 31: 3D shape measuring section,
32: 2D image capturing unit, 40: control unit, 41, 4
2 ... Image memory 43 ... Microcomputer 3
11 ... second image sensor (drive processing circuit) 321 ... first image sensor (drive processing circuit) 323 ... visible light transmitting filter

Claims (3)

[Claims] An object has a slit light projecting unit for irradiating slit light on an object to be measured, and an imaging unit for imaging the surface of the object to be measured, and the imaging unit relatively moves around the object to be measured. A reading device provided with a rotating mechanism that moves, wherein the imaging section receives visible light reflected light from the front portion of the measured object by a first imaging element and reads luminance information of a surface; Three-dimensional object reading means for measuring the surface shape by receiving the slit light reflected light of the slit light applied to the same area as the front portion of the measurement object by the second imaging element. 3D object and its surface image reading device. 2. The three-dimensional object and the surface image reading device according to claim 1, further comprising a visible light transmitting filter provided on a light receiving surface side of the first image sensor. 3. The apparatus for reading a three-dimensional object and its surface image according to claim 1, wherein said first image pickup device is arranged so as to face a front part of said object to be measured.