JP6529248B2 - Inspection system and flexible lighting device - Google Patents

Description

  Embodiments of the present invention relate to inspection systems and flexible lighting devices.

  Conventionally, a technique has been proposed which irradiates light to an object to be inspected, images reflected light from the surface of the object to be inspected as image data, and detects an abnormality of the object to be inspected based on a change in luminance of the image data. It is done.

  At that time, a technique has been proposed in which the intensity of light to be irradiated to the inspection object is periodically changed, and an abnormality is detected based on a change in luminance of captured image data.

JP 2014-2125 A

  In an inspection system using image processing, there are cases where the inspection can be performed more effectively by changing the position and orientation of the illumination unit with respect to the surface to be inspected.

The inspection system according to the embodiment has a curved surface-shaped illumination unit which is arranged to face the surface to be inspected and a plurality of support units which support the sides of the illumination unit so as to be changeable in the support position. A deformation mechanism that deforms the illumination unit by changing the position of the support unit at at least two of the three points while supporting the illumination unit at three or more points along the side of the illumination unit; And an arithmetic processing unit configured to calculate a feature for detecting an abnormality based on the image captured by the imaging unit.

FIG. 1 is a diagram showing a configuration example of an inspection system including the calibration system of the first embodiment. FIG. 2 is a block diagram showing the configuration of the time correlation camera of the first embodiment. FIG. 3 is a conceptual diagram showing frames stored in time series order by the time correlation camera of the first embodiment. FIG. 4 is a view showing an example of a fringe pattern irradiated by the illumination device of the first embodiment. FIG. 5 is a view showing a first example of detection of an abnormality of an object under test by the time correlation camera of the first embodiment. FIG. 6 is a diagram showing an example of the amplitude of light which changes in response to an abnormality shown in FIG. 5 when the object under test has the abnormality. FIG. 7 is a diagram showing a second example of detection of an abnormality of the object under inspection by the time correlation camera of the first embodiment. FIG. 8 is a diagram showing a third example of detection of an abnormality of the object under inspection by the time correlation camera of the first embodiment. FIG. 9 is a view showing an example of a fringe pattern which the illumination control unit of the first embodiment outputs to the illumination device. FIG. 10 is a view showing an example of the shape of a wave representing a stripe pattern after passing through the screen of the first embodiment. FIG. 11 is a flowchart showing the procedure of abnormality detection processing based on the amplitude in the abnormality detection processing unit of the first embodiment. FIG. 12 is a flowchart showing a procedure of abnormality detection processing based on a phase in the abnormality detection processing unit of the first embodiment. FIG. 13 is a flowchart showing a procedure of abnormality detection processing based on amplitude and intensity in the abnormality detection processing unit of the first embodiment. FIG. 14 is a flowchart showing the procedure of the inspection process of the object in the inspection system of the first embodiment. FIG. 15 is a diagram showing an example of switching of a fringe pattern output by the illumination control unit of the second modification. FIG. 16 is a diagram showing an example in which the illumination control unit of Modification 2 irradiates the surface including defects (defects) with a stripe pattern. FIG. 17 is a diagram showing the relationship between an abnormality (defect) and a fringe pattern on the screen when the fringe pattern is changed in the y direction. FIG. 18 is a diagram showing an example of a fringe pattern which the illumination control unit of the modification 3 outputs to the illumination device. FIG. 19 is an exemplary and schematic configuration diagram of the lighting device of the embodiment. FIG. 20 is an exemplary and schematic view of the position and the attitude of the illumination unit according to the embodiment set according to the part of the test subject. FIG. 21 is a schematic perspective view of an example of a deformed state and a fringe pattern of the illumination unit according to the embodiment. FIG. 22 is a schematic perspective view of another example of the deformed state and the fringe pattern of the illumination unit according to the embodiment. FIG. 23 is an exemplary diagram showing the illumination unit of the embodiment deformed corresponding to the surface to be inspected, the fringe pattern outputted by the illumination unit, and the optical path from the illumination unit of the fringe pattern to the time correlation camera. And it is a schematic diagram.

<Basic configuration of time correlation camera>
The inspection system of the present embodiment will be described. The inspection system 1 according to the first embodiment has various configurations in order to inspect a subject. FIG. 1 is a view showing a configuration example of an inspection system of the present embodiment. As shown in FIG. 1, the inspection system of the present embodiment includes a PC 100, a time correlation camera 110, an illumination device 120, and a moving mechanism 140. The time correlation camera 110 is an example of an imaging unit.

  The moving mechanism 140 is used to fix the test object 150, and changes the position and orientation of the surface of the test object 150 that can be photographed by the time correlation camera 110 according to the control from the PC 100.

  The illumination device 120 is a device that irradiates light to the inspection object 150, and can control the intensity of the light to be irradiated in area units in accordance with the stripe pattern from the PC 100. Furthermore, the lighting device 120 can control the intensity of light in the area unit according to the periodic time transition. In other words, the lighting device 120 can provide periodic time variation and spatial variation of the light intensity. A specific light intensity control method will be described later.

  The illumination unit 121 of the illumination device 120 planarly illuminates the inspection object 150. The illumination unit 121 of the present embodiment planarly illuminates the inspection object 150 with the light to which the periodic time change and the spatial change input from the illumination device 120 are given.

  In addition, although this embodiment demonstrates the example which comprises the planar irradiation part which gives a periodic time change of a light intensity, and a space change, it is not restrict | limited to such a combination, For example, LED You may arrange | position in order and comprise an illumination part.

  The time correlation camera 110 includes an optical system 210, an image sensor 220, a data buffer 230, a control unit 240, and a reference signal output unit 250. FIG. 2 is a block diagram showing the configuration of the time correlation camera 110 according to the present embodiment.

  The optical system 210 includes a photographing lens and the like, transmits a light flux from a subject (including a subject to be inspected) outside the time correlation camera 110, and forms an optical image of the subject formed by the light flux.

  The image sensor 220 is a sensor capable of outputting the intensity of light incident through the optical system 210 at high speed for each pixel as a light intensity signal.

  The light intensity signal of the present embodiment is that the illumination device 120 of the inspection system emits light to a subject (including the subject to be inspected), and the image sensor 220 receives the reflected light from the subject.

  The image sensor 220 is, for example, a sensor that can read out at high speed as compared with the conventional one, and is in a two-dimensional planar shape in which pixels are arrayed in two types of row direction (x direction) and column direction (y direction). It shall be constructed. Then, let each pixel of the image sensor 220 be a pixel P (1,1),..., P (i, j),..., P (X, Y) (note that the image size of this embodiment is X). X Y.). Note that the reading speed of the image sensor 220 is not limited, and may be the same as that in the related art.

  The image sensor 220 receives a light flux from an object (including an inspection object) transmitted by the optical system 210 and photoelectrically converts the light flux to a light intensity signal (photographing the light reflected from the object) And generates a two-dimensional planar frame, which is output to the control unit 240. The image sensor 220 of the present embodiment outputs the frame for each readable unit time.

  The control unit 240 according to the present embodiment includes, for example, a CPU, a ROM, and a RAM, and executes the inspection program stored in the ROM to transfer the transfer unit 241, the reading unit 242, and the intensity image superimposing unit 243. A first multiplier 244, a first correlation image superposition unit 245, a second multiplier 246, a second correlation image superposition unit 247, and an image output unit 248 are realized. Note that the present invention is not limited to being realized by a CPU or the like, and may be realized by an FPGA or an ASIC.

  The transfer unit 241 stores, in the data buffer 230, the frames composed of the light intensity signal, which are output from the image sensor 220, in chronological order.

  The data buffer 230 accumulates the frames composed of the light intensity signal output from the image sensor 220 in chronological order.

  FIG. 3 is a conceptual diagram showing frames accumulated in time series order by the time correlation camera 110 of the present embodiment. As shown in FIG. 3, in the data buffer 230 of this embodiment, a plurality of light intensity signals G (1,1, t), for each time t (t = t0, t1, t2,..., Tn) ..., G (i, j, t), ..., G (X, Y, t) composed of a plurality of frames Fk (k = 1, 2, ..., n) are in chronological order It is accumulated. Note that one frame created at time t is the light intensity signal G (1,1, t),..., G (i, j, t),..., G (X, Y, t) Configured

  In the light intensity signals (imaging signals) G (1, 1, t), ..., G (i, j, t), ..., G (X, Y, t) of the present embodiment, the frame image F k ( Each pixel P (1, 1), ..., P (i, j), ..., P (X, Y) which constitutes k = 1, 2, ..., n is associated.

  The frame output from the image sensor 220 is constituted only by the light intensity signal, and in other words, it can be considered as monochrome image data. In the present embodiment, an example in which the image sensor 220 generates monochrome image data in consideration of resolution, sensitivity, cost, and the like will be described. However, if the image sensor 220 is limited to an image sensor for monochrome Alternatively, a color image sensor may be used.

  Returning to FIG. 2, the reading unit 242 of this embodiment receives the light intensity signals G (1,1, t),..., G (i, j, t),. Y, t) are read in chronological order in frame units, and are output to the first multiplier 244, the second multiplier 246, and the intensity image superimposing unit 243.

  The time correlation camera 110 of the present embodiment generates image data for each output destination of the reading unit 242. In other words, the inter-time phase camera 110 creates three types of image data.

  The time correlation camera 110 according to the present embodiment generates intensity image data and two types of time correlation image data as the three types of image data. Note that the present embodiment is not limited to the generation of three types of image data, and may be considered not to generate intensity image data, or to generate one or more types of time correlation image data. .

  As described above, the image sensor 220 of the present embodiment outputs a frame formed of light intensity signals every unit time. However, in order to generate normal image data, light intensity signals for the exposure time necessary for photographing are required. Therefore, in the present embodiment, the strength image superimposing unit 243 generates strength image data by superimposing a plurality of frames for the exposure time required for photographing. In addition, each pixel value (value representing the light intensity) G (x, y) of the intensity image data can be derived from the equation (1) shown below. The exposure time is a time difference between t0 and tn.

  As a result, as in the case of conventional camera imaging, intensity image data in which an object (including an inspection object) is imaged is generated. Then, the intensity image superimposing unit 243 outputs the generated intensity image data to the image output unit 248.

  Temporally correlated image data is image data indicating changes in light intensity depending on time transition. That is, in the present embodiment, for each frame in chronological order, the light intensity signal included in the frame is multiplied by the reference signal indicating time transition, and the reference signal, the light intensity signal, and the time as the multiplication result A temporal correlation value frame composed of correlation values is generated, and temporal correlation image data is generated by superimposing a plurality of temporal correlation value frames.

  By the way, in order to detect an abnormality of a test object using time correlation image data, it is necessary to change the light intensity signal input to the image sensor 220 in synchronization with the reference signal. For this purpose, it was decided that the illumination device 120 performs planar light illumination periodically giving temporal change and spatial movement of stripes.

In the present embodiment, two types of time correlation image data are generated. The reference signal may be a signal representing time transition, but in the present embodiment, a complex sine wave e ^−jωt is used. The angular frequency ω and time t are used. The angular frequency ω is such that the complex sine wave e ^−jωt representing the reference signal is correlated with one period of the exposure time described above (in other words, the time required to generate the intensity image data, the time correlation image) It shall be set. In other words, the planar and dynamic light formed by the illumination device 120 has the temporal irradiation intensity at the first period (time period) at each position on the surface (reflection surface) of the inspection object 150. As well as providing a change, it provides an increasing or decreasing distribution of spatial illumination intensity at a second period (spatial period) along at least one direction along the surface. When this planar light is reflected by the surface, it is complex modulated according to the specs (the distribution of normal vectors, etc.) of the surface. The temporal correlation camera 110 receives complex-modulated light on the surface, and performs quadrature detection (orthogonal demodulation) using a first cycle reference signal to obtain temporal correlation image data as a complex signal. By modulation / demodulation based on such complex time correlation image data, a feature corresponding to the distribution of the surface normal vector can be detected.

The complex sine wave e ^−jωt can also be expressed as e ^−jωt = cos (ωt) −j · sin (ωt). Therefore, each pixel value C (x, y) of the temporal correlation image data can be derived from the equation (2) shown below.

  In this embodiment, in equation (2), two kinds of time correlation image data are divided into a pixel value C1 (x, y) representing a real part and a pixel value C 2 (x, y) representing an imaginary part. Generate

Therefore, the reference signal output unit 250 generates and outputs different reference signals to the first multiplier 244 and the second multiplier 246, respectively. Reference signal output section 250 of this embodiment outputs the first reference signal cosωt corresponding to the real part of the complex sine wave e ^-Jeiomegati the first multiplier 244, the imaginary part of the complex sine wave e ^-Jeiomegati The corresponding second reference signal sin ωt is output to the second multiplier 246. Thus, although the reference signal output part 250 of this embodiment demonstrates the example which outputs two types of reference signals represented as a time function of the sine wave which mutually makes a Hilbert transform pair, and a cosine wave, a reference signal is time It may be a reference signal that changes according to time transition such as a function.

Then, the first multiplier 244 ^sets the real part cosωt of the complex sine wave e ^−jωt input from the reference signal output unit 250 for each light intensity signal of the frame in units of frames input from the reading unit 242. Multiply.

  The first correlation image superimposing unit 245 performs a process of superimposing, for each pixel, the multiplication result of the first multiplier 244 on a plurality of frames for the exposure time necessary for photographing. Thereby, each pixel value C1 (x, y) of 1st time correlation image data is derived | led-out from the following formula | equation (3).

Then, the second multiplier 246 multiplies the light intensity signal of the frame input from the reading unit 242 by the imaginary part sin ^ωt of the complex sine wave e ^−jωt input from the reference signal output unit 250.

  The second correlation image superimposing unit 247 superimposes, for each pixel, the multiplication result of the second multiplier 246 on a plurality of frames for the exposure time necessary for photographing. Thereby, each pixel value C2 (x, y) of 2nd time correlation image data is derived | led-out from the following formula | equation (4).

  By performing the processing described above, it is possible to generate two types of time correlated image data, in other words, time correlated image data having two degrees of freedom.

Also, the present embodiment does not limit the type of reference signal. For example, in this embodiment, two types of time correlation image data of the real part and the imaginary part of the complex sine wave e ^−jωt are created, but two types of image data are generated by the light amplitude and the light phase. You may

  In addition, the time correlation camera 110 of this embodiment enables creation of multiple systems as time correlation image data. Thus, for example, when light in which stripes of a plurality of types of widths are combined is irradiated, it is possible to create two types of time-correlated image data of the real part and the imaginary part described above for each width of stripes. To this end, the time correlation camera 110 is provided with a plurality of combinations of a combination of two multipliers and two correlation image superimposing units, and the reference signal output unit 250 has an angular frequency suitable for each system. It is possible to output the reference signal by ω.

  Then, the image output unit 248 outputs the two types of time correlation image data and the intensity image data to the PC 100. Thereby, the PC 100 detects an abnormality of the object under inspection using two types of time correlation image data and intensity image data. For that purpose, it is necessary to irradiate light to the subject.

  The illumination device 120 of the present embodiment illuminates a fringe pattern moving at high speed. FIG. 4: is the figure which showed an example of the fringe pattern which the illuminating device 120 of this embodiment irradiates. In the example shown in FIG. 4, the stripe pattern is assumed to be scrolled (moved) in the x direction. White areas correspond to bright areas corresponding to stripes, and black areas correspond to spaced areas (dark areas) corresponding to stripes.

  In the present embodiment, the fringe pattern irradiated by the illumination device 120 is moved by one cycle in the exposure time at which the time correlation camera 110 captures intensity image data and time correlation image data. Thus, the lighting device 120 provides periodic time variation of light intensity due to the spatial movement of the fringe pattern of light intensity. In the present embodiment, the time for which the fringe pattern in FIG. 4 moves by one cycle corresponds to the exposure time, so that each pixel of the time-correlated image data relates to at least an intensity signal of light for one cycle of the fringe pattern. Information is embedded.

  As shown in FIG. 4, in the present embodiment, an example in which the illumination device 120 irradiates a stripe pattern based on a rectangular wave will be described, but a device other than the rectangular wave may be used. In addition, the boundary area of the light and dark of a square wave can be blurred by using the diffusion member which diffuses illumination light.

  In the present embodiment, the fringe pattern irradiated by the illumination device 120 is represented as A (1 + cos (ωt + kx), that is, the fringe pattern repeatedly (periodically) includes a plurality of fringes. Let the intensity of the light irradiated to be adjustable between 0 and 2 A, and let it be the phase kx of light, where k is the wave number of stripes, and x is the direction in which the phase changes.

  The fundamental frequency component of the light intensity signal f (x, y, t) of each pixel of the frame can be expressed as the following equation (5). As shown in equation (5), the light and dark of the stripes change in the x direction.

f (x, y, t) = A (1 + cos (ωt + kx))
= A + A / 2 {e ^{j (ωt + kx)} + e- ^{j (ωt + kx)} } (5)

  As shown in equation (5), the intensity signal of the fringe pattern illuminated by the illumination device 120 can be considered as a complex number.

  Then, the light from the illumination device 120 is reflected and input from the subject (including the subject to be inspected) to the image sensor 220.

  Therefore, the light intensity signal G (x, y, t) input to the image sensor 220 can be used as the light intensity signal f (x, y, t) of each pixel of the frame when the illumination device 120 is illuminated. Therefore, equation (6) can be derived by substituting equation (5) into equation (1) for deriving intensity image data. It is assumed that the phase kx.

  From equation (6), it can be confirmed that a value obtained by multiplying the exposure time T by the intermediate value A of the intensity of the light output from the illumination device 120 is input to each pixel of the intensity image data. Furthermore, equation (7) can be derived by substituting equation (5) into equation (2) for deriving time correlation image data. Note that AT / 2 is an amplitude and kx is a phase.

  Thereby, the time correlation image data shown by the complex number shown by Formula (7) can be substituted with two types of time correlation image data mentioned above. That is, the temporal correlation image data composed of the real part and the imaginary part described above includes the phase change and the amplitude change in the light intensity change irradiated to the test object. In other words, the PC 100 according to the present embodiment can detect the phase change of the light emitted from the illumination device 120 and the amplitude change of the light based on the two types of time correlation image data. Therefore, based on the temporal correlation image data and the intensity image data, the PC 100 according to the present embodiment has amplitude image data representing the amplitude of light entering each pixel and phase image data representing the phase change of light entering each pixel. And generate.

  Furthermore, the PC 100 detects an abnormality of the subject based on the generated amplitude image data and phase image data.

  By the way, when the abnormality based on unevenness has arisen in the surface shape of a to-be-inspected object, the change corresponding to the abnormality has arisen in distribution of the normal vector of the surface of a to-be-inspected object. In addition, when there is an abnormality that absorbs light on the surface of the inspection object, the intensity of the reflected light changes. The change in distribution of the normal vector is detected as at least one of phase change and amplitude change of light. Therefore, in the present embodiment, at least one of the phase change and the amplitude change of the light corresponding to the change of the distribution of the normal vector is detected using the temporal correlation image data and the intensity image data. This makes it possible to detect surface shape anomalies. Next, the relationship between the abnormality of the test subject, the normal vector, and the phase change or amplitude change of the light will be described.

  FIG. 5 is a diagram showing a first example of detection of an abnormality of the object under inspection by the time correlation camera 110 of the first embodiment. In the example shown in FIG. 5, it is assumed that there is an abnormality 501 having a projecting shape in the inspection object 500. In this situation, it can be confirmed that the normal vectors 521, 522 and 523 point in different directions in the vicinity of the point 502 of the abnormality 501. Then, when the normal vectors 521, 522, and 523 point in different directions, diffusion (for example, light 511, 512, and 513) occurs in the light reflected from the abnormality 501, and the image sensor 220 of the time correlation camera 110 The width 503 of the stripe pattern entering any pixel 531 of the

  FIG. 6 is a diagram showing an example of the amplitude of light, which changes in accordance with the abnormality when the abnormality 501 shown in FIG. In the example shown in FIG. 6, the amplitude of light is divided into a real part (Re) and an imaginary part (Im) to be represented on a two-dimensional plane. In FIG. 6, the amplitudes 611, 612 and 613 of the light corresponding to the lights 511, 512 and 513 of FIG. 5 are shown. Then, the light amplitudes 611, 612, and 613 cancel each other, and the light having the amplitude 621 is incident on the arbitrary pixel 531 of the image sensor 220.

  Therefore, in the situation shown in FIG. 6, it can be confirmed that the amplitude is small in the region where the abnormality 501 of the test object 500 is imaged. In other words, when there is an area that is darker than the surrounding area in the amplitude image data that shows the amplitude change, it can be inferred that the amplitudes of the light cancel each other out in the area. It can be determined that an abnormality 501 has occurred at the position of the corresponding inspection object 500.

  The inspection system 1 of the present embodiment can detect not only the one having a steep change in slope as in the abnormality 501 of FIG. 5 but also a slowly changing abnormality. FIG. 7 is a diagram showing a second example of detection of an abnormality of the object under inspection by the time correlation camera 110 of the first embodiment. In the example shown in FIG. 7, the surface of the object under inspection becomes flat (in other words, the normals are parallel) in the normal case, but a gentle slope 701 is generated in the object under inspection 700. In such a situation, the normal vectors 721, 722, 723 on the slope 701 also change gradually. Therefore, the lights 711, 712, and 713 input to the image sensor 220 also gradually shift. In the example shown in FIG. 7, since the cancellation of the light amplitude does not occur due to the gentle slope 701, the light amplitude as shown in FIGS. 5 and 6 hardly changes. However, although light originally projected from the illumination device 120 should enter the image sensor parallel as it is, the light projected from the illumination device 120 does not enter the image sensor in a parallel state because of the gentle gradient 701. Phase change occurs in the light. Therefore, by detecting the difference between the phase change of the light and the surroundings, it is possible to detect an abnormality due to the gentle gradient 701 as shown in FIG.

  In addition to the surface shape of the test object (in other words, the distribution of the normal vector of the test object), an abnormality may occur. FIG. 8 is a diagram showing a third example of detection of an abnormality of the object under inspection by the time correlation camera 110 of the first embodiment. In the example shown in FIG. 8, since the dirt 801 adheres to the inspection object 800, the light emitted from the illumination device 120 is absorbed or diffusely reflected, and the dirt 801 of the time correlation camera 110 is photographed. In an arbitrary pixel area, an example in which light hardly changes in intensity is shown. In other words, in an arbitrary pixel area in which the dirt 801 is photographed, the light intensity is phase-cancelled, the vibration component is canceled, and an example in which the brightness is almost DC direct is shown.

  In such a case, in the pixel area where the dirt 801 is captured, there is almost no light amplitude, so when the amplitude image data is displayed, an area that is darker than the surrounding area occurs. Therefore, it can be estimated that there is an abnormality 801 such as dirt at the position of the inspection object 800 corresponding to the area.

  As described above, in the present embodiment, it is possible to estimate that there is an abnormality in the test object by detecting the change in the light amplitude and the change in the light phase based on the time correlation image data.

  Returning to FIG. 1, the PC 100 will be described. The PC 100 controls the entire detection system. The PC 100 includes a moving mechanism control unit 101, a lighting control unit 102, a control unit 103, and a storage unit 109. The storage unit 109 stores data used for arithmetic processing, arithmetic processing results, and the like.

  The movement mechanism control unit 101 controls the movement mechanism 140 in order to change the surface to be imaged by the time correlation camera 110 of the inspection object 150. The moving mechanism 140 is, for example, a robot arm. In the present embodiment, in the PC 100, a plurality of surfaces to be photographed of the inspection object 150 are set. Then, every time when the time correlation camera 110 completes the shooting of the inspection object 150, the movement mechanism control unit 101 can scan the surface on which the time correlation camera 110 is set according to the setting, so that the movement mechanism 140 can The inspection body 150 is moved. In the present embodiment, the moving mechanism 140 is moved each time shooting is completed, and the present invention is not limited to repeating stopping before shooting starts, and the moving mechanism 140 may be driven continuously. . The moving mechanism 140 may also be referred to as a transport unit, a moving unit, a gripping unit, a position changing unit, an attitude changing unit, or the like.

  The illumination control unit 102 outputs a stripe pattern irradiated by the illumination device 120 to inspect the inspection object 150. The illumination control unit 102 according to the present embodiment delivers at least three or more stripe patterns to the illumination device 120 and instructs the illumination device 120 to switch and display the stripe patterns during the exposure time.

  FIG. 9 is a diagram showing an example of a fringe pattern which the illumination control unit 102 outputs to the illumination device 120. As shown in FIG. The illumination control unit 102 performs control such that a stripe pattern in which the black area and the white area illustrated in FIG. 9A are set is output in accordance with the rectangular wave illustrated in FIG. 9B.

  The interval of stripes for each stripe pattern to be irradiated in the present embodiment is set according to the size of the abnormality (defect) to be detected, and the detailed description is omitted here.

  Further, the angular frequency ω of the rectangular wave for outputting the fringe pattern has the same value as the angular frequency ω of the reference signal.

  As shown in FIG. 9, the fringe pattern output from the illumination control unit 102 can be represented as a rectangular wave, but the border region of the fringe pattern is blurred by interposing a diffusion member, that is, bright areas in the fringe pattern It can be made to approximate to a sine wave by slowing down (blunting) the change in light intensity at the boundary between (the area of stripes) and the dark area (the area of intervals). FIG. 10 is a view showing an example of the shape of a wave representing a stripe pattern after passing through a diffusion member. As shown in FIG. 10, when the wave shape approaches a sine wave, the measurement accuracy can be improved. Further, it is also possible to add a gray area in which the lightness changes in multiple steps to the stripes, or to give a gradation. Alternatively, a stripe pattern including color stripes may be used.

  Returning to FIG. 1, the control unit 103 includes an amplitude-phase image generation unit 104 and an abnormality detection processing unit 105, and uses intensity image data input from the time correlation camera 110 and time correlation image data, A process is performed to calculate a feature corresponding to the distribution of the normal vector of the surface to be inspected of the inspection object 150 and detecting an abnormality due to a difference from the surroundings. In this embodiment, in order to perform inspection, instead of time correlation image data (referred to as complex time correlation image data) indicated by complex numbers, two types of real part and imaginary part of the complex correlation image data are divided. Time correlated image data from the time correlated camera 110. The control unit 103 is an example of an arithmetic processing unit.

  The amplitude-phase image generation unit 104 generates amplitude image data and phase image data based on the intensity image data input from the time correlation camera 110 and the time correlation image data.

  The amplitude image data is image data representing the amplitude of light entering each pixel. The phase image data is image data representing the phase of light entering each pixel.

  Although the present embodiment does not limit the method of calculating the amplitude image data, for example, the amplitude-phase image generation unit 104 generates pixel values C1 (x, y) and C2 (x, y) of two types of time correlation image data. Each pixel value F (x, y) of amplitude image data can be derived from y) using equation (8).

  Then, in the present embodiment, it is possible to determine whether there is an area in which an abnormality has occurred, based on the pixel value (amplitude) of the amplitude image data and the pixel value of the intensity image data. For example, in a region where the value obtained by dividing the pixel value (AT) of the intensity image data by 2 and the amplitude of the amplitude image data (it becomes AT / 2 when no cancellation occurs), an abnormality occurs I can guess that it is not. On the other hand, it can be inferred that the cancellation of the amplitude has occurred in the non-coincident region. The specific method will be described later.

  Similarly, from the pixel values C1 (x, y) and C2 (x, y), the amplitude-phase image generation unit 104 calculates each pixel value P (x, y) of the phase image data using Equation (9). Can be derived.

  The abnormality detection processing unit 105 is a feature corresponding to the distribution of the normal vector of the inspection symmetry plane by the amplitude image data and the phase image data generated by the amplitude-phase image generation unit 104, and by the difference with the surroundings. , Detects a feature related to the abnormality of the test object 150. In this embodiment, an example using the distribution of the amplitude of the complex time correlation image will be described as the feature corresponding to the distribution of the normal vector. The distribution of the amplitude of the complex time correlation image is data indicating the distribution of the amplitude of each pixel of the complex time correlation image, and corresponds to amplitude image data.

  Next, the abnormality detection processing based on the amplitude in the abnormality detection processing unit 105 of the present embodiment will be described. FIG. 11 is a flowchart showing the procedure of the process in the abnormality detection processing unit 105 of this embodiment.

  First, the abnormality detection processing unit 105 calculates the average amplitude of the N × N region with reference to the pixel (for example, the center) from (the pixel value representing) the light amplitude value stored in each pixel of the amplitude image data. The values are subtracted (step S1101) to generate average difference image data of amplitude. The average difference image data of the amplitude corresponds to the gradient of the amplitude. The integer N is assumed to be set to an appropriate value according to the embodiment.

  Next, the abnormality detection processing unit 105 performs mask processing on the average difference image data of the amplitude generated by the subtraction using a predetermined threshold value of the amplitude (step S1102).

  Further, the abnormality detection processing unit 105 calculates a standard deviation for each pixel in the mask area of the average difference image data (step S1103). In the present embodiment, a method based on the standard deviation will be described. However, the method is not limited to the case where the standard deviation is used. For example, an average value or the like may be used.

  Then, the abnormality detection processing unit 105 detects a pixel having a value whose amplitude pixel value obtained by subtracting the average is smaller than −4.5σ (σ: standard deviation) as an area having abnormality (defect) (step S1104).

  By the above-described processing procedure, it is possible to detect an abnormality of the object to be inspected from the amplitude value of each pixel (in other words, the distribution of the amplitude). However, the present embodiment is not limited to the detection of an anomaly from the distribution of the amplitude of the complex time correlation image. The gradient of the distribution of the phase may be used as a feature corresponding to the distribution of the normal vector of the test symmetry plane. Then, the example using the gradient of distribution of a phase next is demonstrated.

  Next, abnormality detection processing based on the phase in the abnormality detection processing unit 105 of the present embodiment will be described. FIG. 12 is a flowchart showing the procedure of the process in the abnormality detection processing unit 105 of this embodiment.

  First, the abnormality detection processing unit 105 subtracts the average phase value of the N × N region from the phase value (pixel value representing the light value) of light of each pixel of the phase image data with the pixel as a reference (for example, center). (Step S1201), phase average difference image data is generated. The average differential image data of the phase corresponds to the gradient of the phase.

  Next, the abnormality detection processing unit 105 compares the size (absolute value) of the average difference image data of the phase generated by the subtraction with the threshold, and determines the pixels for which the size of the average difference image data is equal to or larger than the threshold. The pixel is detected as an abnormal (defective) pixel (step S1202).

  Based on the detection result of S1202, the abnormality detection processing unit 105 can determine unevenness by the positive / negative of the average difference image data, that is, the magnitude relationship between the phase value of the pixel and the average phase value (step S1203). Which of the phase value of the pixel and the average phase value is larger changes depending on the setting of each part, but the unevenness is different if the magnitude relationship is different.

  An anomaly can be detected from the gradient of the phase distribution obtained by another method. For example, as another method, as the abnormality detection processing unit 105, the magnitude of the difference between the average vector of the N × N region of the normalized time correlation image data and the vector of each normalized pixel is a threshold If it is larger, it can be detected as an abnormal (defective) pixel. Further, the abnormality of the object to be inspected may be detected based on information corresponding to the distribution of the phase, not limited to the gradient of the distribution of the phase.

  Next, abnormality detection processing based on the amplitude and the intensity in the abnormality detection processing unit 105 of the present embodiment will be described. FIG. 13 is a flowchart showing the procedure of the process in the abnormality detection processing unit 105 of this embodiment.

  First, the abnormality detection processing unit 105 uses the following equation (100) for each pixel from the temporal correlation image data and the intensity image data, and calculates the amplitude (pixel value representing C) x (x, y) 7) The ratio R (x, y) of the reference (see) and the intensity (pixel value representing the) G (x, y) (see the equation (6)) is calculated (step S1301).

R (x, y) = C (x, y) / G (x, y) (100)

  Next, the abnormality detection processing unit 105 compares the ratio R (x, y) with the threshold, and the pixel where the value of the ratio R (x, y) is equal to or less than the corresponding threshold is a pixel with abnormality (defect). Is detected (step S1302). Further, the abnormality detection processing unit 105 compares the ratio R (x, y) with the threshold, and makes the pixel having the value of the ratio R (x, y) equal to or higher than another corresponding threshold It is detected as a certain pixel (step S1303). When the cancellation of the amplitude becomes remarkable due to the abnormality of the distribution of the normal vector, the amplitude decreases more than the intensity. On the other hand, although there is no abnormality in the distribution of the normal vector, when the light absorption becomes remarkable due to the contamination of the surface of the inspection object 150 or the like, the intensity is much lower than the amplitude. Therefore, the abnormality detection processing unit 105 can detect the type of abnormality in steps S1302 and S1303.

  Next, the inspection process of the inspection object in the inspection system of the present embodiment will be described. FIG. 14 is a flowchart showing the procedure of the above-described process in the inspection system of the present embodiment. Here, it is assumed that the inspection object 150 is disposed at the initial position of the inspection in a state of being fixed to the moving mechanism 140 already.

  The PC 100 according to the present embodiment outputs a fringe pattern for inspecting the inspection object to the illumination device 120 (step S1401).

  The lighting device 120 stores the fringe pattern input from the PC 100 (step S1421). Then, the lighting device 120 displays the stored stripe pattern so as to change according to the time transition (step S1422). The condition under which the lighting device 120 starts display is not limited when the fringe pattern is stored, and may be, for example, when the examiner performs the start operation on the lighting device 120.

  Then, the control unit 103 of the PC 100 transmits a shooting start instruction to the time correlation camera 110 (step S1402).

  Next, the time correlation camera 110 starts imaging of the area including the test object 150 according to the transmitted imaging instruction (step S1411). Next, the control unit 240 of the time correlation camera 110 generates intensity image data and time correlation image data (step S1412). Then, the control unit 240 of the time correlation camera 110 outputs the intensity image data and the time correlation image data to the PC 100 (step S1413).

  The control unit 103 of the PC 100 receives the intensity image data and the time correlation image data (step S1403). Then, the amplitude-phase image generation unit 104 generates amplitude image data and phase image data from the received intensity image data and time correlation image data (step S1404).

  Then, the abnormality detection processing unit 105 performs abnormality detection control of the test object based on the amplitude image data and the phase image data (step S1405). Then, the abnormality detection processing unit 105 outputs the abnormality detection result to a display device (not shown) included in the PC 100 (step S1406).

  As an output example of the abnormality detection result, while the strength image data is displayed, the inspector performs abnormality on the area of the strength image data corresponding to the area where the abnormality is detected based on the amplitude image data and the phase image data. It is conceivable to display decoration so that it can be recognized. Further, the output is not limited to the visual output, and it may be output that an abnormality is detected by voice or the like.

  The control unit 103 determines whether the inspection of the subject has been completed (step S1407). When it is determined that the inspection is not completed (step S1407: No), the moving mechanism control unit 101 captures the surface of the inspection object to be the next inspection target by the time correlation camera 110 according to the predetermined setting. Movement control of the arm is performed (step S1408). After the movement control of the arm is completed, the control unit 103 transmits an instruction to start shooting again to the time correlation camera 110 (step S1402).

  On the other hand, when determining that the inspection of the subject has been completed (step S1407: YES), the control unit 103 outputs an end instruction to the time correlation camera 110 (step S1409), and ends the process.

  Then, the time correlation camera 110 determines whether an end instruction has been received (step S1414). If the end instruction has not been received (step S1414: NO), the processing is performed again from step S1411. On the other hand, if the end instruction has been received (step S1414: YES), the process ends.

  In addition, an inspector may perform termination processing of the illumination device 120, and may terminate according to an instruction from another configuration.

  Further, in the present embodiment, an example has been described in which intensity image data generated using the time correlation camera 110 and time correlation image data are generated. However, the present invention is not limited to the use of the temporal correlation camera 110 to generate intensity image data and temporal correlation image data, but may be a temporal correlation camera that can be realized by analog processing or an equivalent operation. An imaging system may be used. For example, the image data generated by a normal digital still camera is output, and the information processing apparatus superimposes the time correlated image data by superposing a reference signal using the image data generated by the digital still camera as frame image data. The time-correlated image data may be generated using a digital camera that may generate a reference signal in a light intensity signal in an image sensor.

(Modification 1)
In the present embodiment, an example of detecting a feature related to an abnormality based on the difference with the surroundings has been described, but the present invention is not limited to detecting the feature based on the difference with the surroundings. The feature may be detected based on the difference with data (reference data, for example, time correlation data, amplitude image data, phase image data, etc.). In this case, alignment and synchronization of spatial phase modulation illumination (fringe pattern) is required in the case of reference data.

  In this modification, the abnormality detection processing unit 105 stores amplitude image data and phase image data obtained from the reference surface, which are stored in advance in the storage unit 109, and amplitude image data and phase image data of the test object 150. To determine whether or not there is a difference of at least one of the light amplitude and the light phase between the surface of the test object 150 and the reference surface.

  In this modification, an inspection system having the same configuration as that of the first embodiment is used, and a surface of a normal inspection object is used as a reference surface.

  While illumination device 120 is illuminating the fringe pattern, time-correlated camera 110 images the surface of a normal subject and generates time-correlated image data. Then, the PC 100 inputs time correlation image data generated by the time correlation camera 110, generates amplitude image data and phase image data, and stores the amplitude image data and phase image data in the storage unit 109 of the PC 100. . Then, the time correlation camera 110 picks up an inspection object to be determined whether or not an abnormality has occurred, and generates time correlation image data. Then, after the PC 100 generates amplitude image data and phase image data from the temporal correlation image data, the PC 100 compares the amplitude image data and phase image data of the normal inspection object stored in the storage unit 109. At that time, the comparison result of the amplitude image data and the phase image data of the normal test object, and the amplitude image data and the phase image data of the test object to be inspected is used as data showing the feature for detecting the abnormality. Output. Then, when the feature for detecting an abnormality is equal to or more than the predetermined reference, it can be estimated that the inspection object 150 has an abnormality.

  Thus, in the present modification, it can be determined whether or not there is a difference from the surface of a normal test object, in other words, whether or not an error is generated on the surface of the test object. In addition, since the comparison method of amplitude image data and phase image data may use what kind of method, description is abbreviate | omitted.

  Furthermore, in the present modification, an example of outputting data indicating a feature for detecting an abnormality based on the difference from the reference surface has been described. However, the difference from the reference surface and the surroundings shown in the first embodiment The feature of detecting an abnormality may be calculated by combining the difference of The method to be combined may use any method, so the description will be omitted.

(Modification 2)
In the first embodiment, an example has been described in which a stripe pattern is moved in the x direction to detect an abnormality (defect) of an inspection object. However, when an abnormality (defect) in which the distribution of the normal changes sharply in the y direction perpendicular to the x direction occurs in the object to be inspected, the stripe pattern is moved in the y direction rather than moving the stripe pattern in the x direction It may be easier to detect defects. Therefore, in the modification, an example in which the stripe pattern moving in the x direction and the stripe pattern moving in the y direction are alternately switched will be described.

  The illumination control unit 102 of the present modification switches the fringe pattern to be output to the illumination device 120 at predetermined time intervals. Thus, the lighting device 120 outputs a plurality of stripe patterns extending in different directions with respect to one inspection target surface.

  FIG. 15 is a diagram showing an example of switching of the stripe pattern output by the illumination control unit 102 of the present modification. In (A) of FIG. 15, the illumination control unit 102 causes the stripe pattern displayed by the illumination device 120 to transition in the x direction. Thereafter, as shown in (B), the illumination control unit 102 causes the stripe pattern displayed by the illumination device 120 to transition in the y direction.

  Then, the control unit 103 of the PC 100 performs abnormality detection based on the time correlation image data obtained from the fringe pattern irradiation of (A) of FIG. 15, and is obtained from the fringe pattern irradiation of (B) of FIG. Anomaly detection is performed based on time correlation image data.

  FIG. 16 is a diagram showing an example in which the illumination control unit 102 of the present modification irradiates the surface including the abnormality (defect) 1601 with a stripe pattern. In the example shown in FIG. 16, an abnormality (defect) 1601 extends in the x direction. In this case, the illumination control unit 102 sets the stripe pattern to move in the y direction intersecting the x direction, in other words, in the direction intersecting the longitudinal direction of the abnormality (defect) 1601. The setting can improve detection accuracy.

  FIG. 17 is a diagram showing the relationship between the abnormality (defect) 1701 and the stripe pattern on the illumination device 120 when the stripe pattern is changed in the y direction, in other words, in the direction orthogonal to the longitudinal direction of the defect 1701. . As shown in FIG. 17, when an abnormality (defect) 1701 occurs in which the width is narrow in the y direction and the x direction intersecting the y direction is a longitudinal direction, the light emitted from the illumination device 120 is The cancellation of the light amplitude becomes large in the y direction crossing the x direction. Therefore, the PC 100 can detect the abnormality (defect) from the amplitude image data corresponding to the stripe pattern moved in the y direction.

  In the inspection system of the present modification, when the longitudinal direction of the defect generated in the inspection object is random, a stripe pattern is displayed in a plurality of directions (for example, the x direction and the y direction intersecting the x direction). Thus, the defect can be detected regardless of the shape of the defect, and the detection accuracy of the abnormality (defect) can be improved. Further, by projecting the stripe pattern in accordance with the shape of the abnormality, it is possible to improve the detection accuracy of the abnormality.

(Modification 3)
Moreover, the modification 2 mentioned above does not restrict | limit to the method of switching a fringe pattern, when performing the abnormality detection of ax direction, and the abnormality detection of ay direction. Therefore, in the third modification, an example will be described in which the stripe pattern output to the illumination device 120 by the illumination control unit 102 is simultaneously moved in the x direction and the y direction.

  FIG. 18 is a diagram showing an example of a fringe pattern output to the illumination device 120 by the illumination control unit 102 of the present modification. In the example shown in FIG. 18, the illumination control unit 102 moves the fringe pattern in the direction 1801.

  The fringe pattern shown in FIG. 18 includes a fringe pattern of one cycle 1802 in the x direction, and includes a fringe pattern of one cycle 1803 in the y direction. That is, the stripe pattern shown in FIG. 18 has a plurality of stripes extending in the cross direction different in width. In addition, it is necessary to make the width of the stripe pattern in the x direction different from the width of the stripe pattern in the y direction. As a result, when generating the time correlated image data corresponding to the x direction and the time correlated image data corresponding to the y direction, the corresponding reference signals can be made different. In addition, since it is only necessary to change the period (frequency) of the change in light intensity due to the stripe pattern, the moving speed of the stripe pattern (stripe) may be changed instead of changing the width of the stripe.

  Then, the temporal correlation camera 110 generates temporal correlation image data corresponding to the fringe pattern in the x direction based on the reference signal corresponding to the fringe pattern in the x direction, and based on the reference signal corresponding to the fringe pattern in the y direction. Time-correlated image data corresponding to the stripe pattern in the y direction is generated. Thereafter, the control unit 103 of the PC 100 performs abnormality detection based on the time correlation image data corresponding to the stripe pattern in the x direction, and then detects the abnormality based on time correlation image data corresponding to the stripe pattern in the y direction. I do. Thereby, in this modification, detection becomes possible regardless of the direction in which the defect has occurred, and the detection accuracy of the abnormality (defect) can be improved.

<Flexible surface emitting lighting>
The illumination device 120 (flexible illumination device), as shown in FIG. 1, includes a flat illumination portion 121 which can be deformed in a curved shape, and a support device 130 which deforms the illumination portion 121 and holds the deformed attitude. And.

  The illumination unit 121 is a flexible display having a thin film shape, and is, for example, an organic electro-luminescent display. The illumination unit 121 is flexible and has a required elasticity, and for example, a smooth curved shape (curved surface shape) can be obtained according to the three-dimensional position of a plurality of grip points separated from one another. Is configured. The illumination unit 121 has an irradiated surface 121 a (front surface, output surface) to emit light, and a back surface 121 b supported by the support device 130. The irradiation surface 121a may be covered with a diffusion film (diffusion member) that diffuses and transmits light. In this case, the diffusion film is at least flexible.

  As illustrated in FIG. 19, the support device 130 includes a support member 131 and a deformation mechanism 132. The support member 131 is a rigid member having, for example, a plate-like, rod-like, frame-like, or lattice-like shape, and supports the plurality of deformation mechanisms 132. The plurality of deformation mechanisms 132 are arranged on the support member 131 at, for example, constant intervals (equal intervals).

  The deformation mechanism 132 has a movable portion 133 and a movable support portion 134. The movable support portion 134 is fixed to the support member 131, and movably supports the movable portion 133. The movable support portion 134 is an example of an actuator. That is, the movable support portion 134 can include, for example, a motor, a motion conversion mechanism (for example, a gear mechanism), and the like, and when the motor is included, the stator of the motor is fixed to the support member 131. The rotation is converted into linear movement of the movable portion 133 via a motion conversion mechanism or the like. Note that various motors can be adopted as the motor. The movement of the movable support 134 as an actuator is controlled by the drive device 123. By being controlled by the drive device 123, the movable support portion 134 can move the movable portion 133 and can hold it at a predetermined position (controlled position).

  The movable portion 133 includes two arms 133a and 133b, and a connecting portion 133c that rotatably connects the arms 133a and 133b. The arm 133a is disposed in a posture along a direction (for example, an orthogonal direction) intersecting the direction in which the support member 131 extends. In FIG. 19, the direction in which the support member 131 extends is the left-right direction, and the direction intersecting the direction in which the support member 131 extends is the up-down direction. Each arm 133a is movably supported by the movable support 134 along the longitudinal direction of the arm 133a. The plurality of arms 133a are arranged in parallel to one another.

  The arm 133 b is interposed between the arm 133 a and the illumination unit 121. One end of the arm 133 b is connected to the movable portion 133 a via a connecting portion 133 c. The connecting portion 133c supports the arm 133b so as to be relatively rotatable around the rotation center along the direction perpendicular to the paper surface of FIG. The other end of the movable portion 133 b is connected to the support portion 121 c of the illumination unit 121 via the connection portion 135. The connecting portion 135 is, for example, configured as a ball joint, and can connect the movable portion 133b and the supporting portion 121c in various directions and angles.

  In the configuration described above, by determining the positions of the plurality of arms 133 a with respect to the movable support 134 or the support member 131, the shape (posture, position) of the illumination unit 121 can be determined. The shape of the illumination unit 121 is determined based on the three-dimensional arrangement of the movable unit 133 a, the connection points 133 c and 135, and the elasticity of the illumination unit 121. In addition, about at least one connection part 133c, 135, it can be made non-rotatable, In that case, an electromagnetic actuator is provided and the possibility of rotation in the said connection part 133c, 135, ie, locking and locking of rotation, is possible. The release can be configured to be electrically switchable.

  As shown in FIG. 1, the illumination control unit 102 of the PC 100 includes a deformation control unit 102 b. The plurality of movable support portions 134 are controlled by the deformation control unit 102 b controlling the drive device 123 shown in FIG. 19, whereby the positions of the plurality of movable portions 133 a are determined, whereby the shape of the illumination unit 121 is obtained. Is determined. As shown in FIG. 1, the PC 100 includes a storage unit 109, and the storage unit 109 stores data of the position of the movable unit 133a corresponding to the required shape of the illumination unit 121. . The data of the position of the movable portion 133a is acquired and stored in advance based on calculation, simulation, experiment, and the like. The deformation control unit 102 b receives, for example, a command indicating the shape of the illumination unit 121 from the control unit 103, acquires data corresponding to the command from the storage unit 109, and outputs the data to the drive device 123. The drive device 123 receives the data, and controls the movable support 134 so that the lighting unit 121 has a shape corresponding to the data, that is, a shape corresponding to an instruction of the control unit 103.

  Further, as shown in FIG. 1, the illumination control unit 102 of the PC 100 includes a light emission control unit 102 a. The light emission control unit 102b controls the drive circuit 122 shown in FIG. 19 to control the light emission pattern of the illumination unit 121, that is, the irradiation pattern on the inspection surface 151 of the inspection object 150.

  As shown in FIG. 20, the deformation mechanism 132 controlled by the deformation control unit 102b turns the illumination unit 121 into a curved surface substantially along the uneven shape of the inspection surface 151 (inspection target surface) of the inspection object 150. It can be deformed. In the example of FIG. 20, the curvature radius of the illumination unit 121 at the position Pd1 corresponding to the region Ad1 having a large curvature radius in the inspection surface 151 is the curvature radius of the illumination unit 121 at a position Pd2 corresponding to the region Ad2 having a small curvature radius. It's bigger than that. That is, the deformation mechanism 132 can deform the illumination unit 121 into different shapes according to the respective portions of the surface to be inspected 151. Such setting tends to reduce the variation in light intensity depending on the position of the inspection surface 151.

  In the configuration described above, the deformation control unit 102b can change the shape of the illumination unit 121, and the light emission control unit 102a can change the stripe pattern as the light emission pattern in the illumination unit 121. 21 and 22 show an example of the shape of the illumination unit 121 and a stripe pattern. In the illumination part 121 shown in FIGS. 21 and 22, the supporting positions (P11, P12, P13, P14, P21) in total 16 places because the corner parts are common to five places each along the four sides of the square shape. , P31, P41, P15, P25, P35, P45, P52, P53, P54, and P55) are set. The connection part 135 and the deformation | transformation mechanism 132 like FIG. 19 are provided corresponding to each support position. The deformation mechanism 132 controlled by the deformation control unit 102b changes the position of the movable unit 133 in the vertical direction in FIGS. It can be set to a shape.

  In the example of FIG. 21, the illumination unit 121 extends straight in the X direction in the drawing, and is bent in a convex curved shape in the Y direction in the drawing toward the lower side in the drawing. That is, the illumination unit 121 is bent in a curved shape having a generatrix along the X direction. Further, in this shape, the light emission control unit 102a controls the illumination unit 121 so as to output a stripe pattern moving along a direction (X direction) along which the generatrix extends and moving along a direction orthogonal to the X direction. . That is, in FIG. 21, the extending direction Dg of the fringe pattern is parallel to the X direction, and the moving direction Dp of the fringe pattern is orthogonal to the X direction.

  Further, in the example of FIG. 22, the illumination unit 121 extends straight in the Y direction in the drawing and is bent in a convex curved shape toward the lower side in the drawing in the X direction in the drawing. That is, the illumination unit 121 is bent in a curved shape having a generatrix along the Y direction. Further, in this shape, the light emission control unit 102a controls the illumination unit 121 so as to output a stripe pattern moving along a direction (Y direction) along which the generatrix extends and moving along a direction orthogonal to the Y direction. . That is, in FIG. 22, the extending direction Dg of the stripe pattern is parallel to the Y direction, and the moving direction Dp of the stripe pattern is orthogonal to the Y direction.

  As is apparent from the above and FIGS. 21 and 22, according to the present embodiment, the deformation mechanism 132 is a phase in which the directions of generatrix cross each other (for example, are orthogonal) when viewed from one direction of one lighting unit 121 It can be deformed in different curved shapes. In addition, the illumination unit 121 can output stripe patterns orthogonal to each other when viewed from one direction, and extends along the generatrix of the curved surface and spatially moves in a direction intersecting the generatrix, for example, a direction orthogonal to the generatrix Can be output.

  In addition, as illustrated in FIG. 23, the light emission control unit 102a sets the width of the stripe pattern in the illumination unit 121 so that the width of the stripe pattern is substantially equal in the image acquired by the time correlation camera 110. . That is, the illumination unit 121 determines that the dispersion (standard deviation) of the widths of the plurality of fringe patterns in the image acquired by the time correlation camera 110 is equal to or less than the dispersion (standard deviation) of the fringe patterns on the irradiation surface 121 a of the illumination unit 121. Output a fringe pattern so that In the case where an inspection is performed for each of a plurality of parts (areas) set by dividing the surface to be inspected 151 for one inspection object 150, the storage unit 109 stores the relevant parts for each part. Data of the position of the movable part 133a corresponding to the shape of the part is stored, and data of the width of the stripe pattern corresponding to the position of the irradiation surface 121a of the illumination part 121 is stored. The width of the stripe pattern according to the position of the irradiation surface 121a of the illumination unit 121 is acquired and stored in advance based on calculations, simulations, experiments, and the like.

  As described above, in the present embodiment, for example, the inspection system 1 includes the planar illumination unit 121 that can be deformed into a curved surface. Further, the deformation mechanism 132 deforms the illumination unit 121 into a curved surface shape substantially along the uneven shape of the inspection surface 151. Further, the deformation mechanism 132 deforms the illumination unit 121 into different shapes according to the portions of the plurality of inspection surfaces 151. Further, the deformation mechanism 132 can change the illumination unit 121 into a plurality of curved surface shapes in which the directions of the generatrix of the deformation of the illumination unit 121 are different from each other when viewed from one direction. Therefore, the shape, posture, position, and the like of the illumination unit 121 can be set in accordance with the position and the shape of the inspection surface 151, so that the variation in the light intensity due to the position of the inspection surface 151 is easily reduced. Thus, for example, a more accurate inspection can be performed.

  Further, in the present embodiment, the illumination unit 121 outputs a stripe pattern of the intensity of light that extends along the generatrix of the deformation of the illuminator 121 and spatially moves in a direction intersecting the generatrix. Therefore, in the curved illumination portion 121, the change of the stripe pattern width depending on the place is suppressed.

  Further, in the present embodiment, the illumination unit 121 switches and outputs a stripe pattern of the intensity of light which extends in different directions and spatially moves. Therefore, the detection accuracy of abnormality can be easily improved as compared to the inspection using the one-direction stripe pattern.

  Further, in the present embodiment, the dispersion (standard deviation) of the widths of a plurality of stripe patterns in the image acquired by the time correlation camera 110 (the imaging unit) is the dispersion of the stripe pattern on the irradiation surface 121 a of the illumination unit 121 (standard The fringe pattern is output so as to be less than or equal to the deviation). Therefore, inspection with the time correlation camera 110 using more appropriate fringe patterns becomes possible.

  The inspection program executed by the PC 100 according to the embodiment described above is a file in an installable format or an executable format, and is a computer such as a CD-ROM, a flexible disk (FD), a CD-R, or a DVD (Digital Versatile Disk). It is recorded and provided on a readable recording medium.

  In addition, the inspection program executed by the PC 100 of the above-described embodiment may be stored on a computer connected to a network such as the Internet and provided by being downloaded via the network. In addition, the inspection program and the calibration program executed by the PC 100 of the above-described embodiment may be configured to be provided or distributed via a network such as the Internet.

  While several embodiments and variations of the present invention have been described, these embodiments and variations are presented as examples and are not intended to limit the scope of the invention. These novel embodiments and modifications can be implemented in other various forms, and various omissions, replacements and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and the gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof. For example, the illumination device 120 of the present invention can also be applied to an inspection system having a regular camera that is not a time-correlated camera. Further, the support position of the illumination unit may be in the form of a grid point, and the illumination unit may be deformed into various shapes and postures. Further, the bending direction (the direction of the generatrix) of the illumination part is not limited to the above embodiment.

  DESCRIPTION OF SYMBOLS 1 ... Inspection system, 103 ... Control part (arithmetic processing part), 110 ... Time correlation camera (imaging part) 120 ... (Flexible) illuminating device, 121 ... Illumination part, 132 ... Deformation mechanism, 151 ... Inspection surface.

Claims (11)

A curved illumination unit arranged opposite to the surface to be inspected;
At least two of the three points having a plurality of support portions that support the sides of the illumination portion so that the support position can be changed, and the illumination portion is supported at three or more points along the sides of the illumination portion A deformation mechanism that deforms the illumination unit by changing the position of the support unit ;
An imaging unit for imaging the surface to be inspected;
An arithmetic processing unit that calculates a feature for detecting an abnormality based on the image captured by the imaging unit;
Equipped with an inspection system. The deformation mechanism changes the position of the support at at least two of the three points while supporting the illumination unit at three or more points along the first side of the illumination unit, and The lighting unit is deformed by changing the position of the supporting unit at at least two of the three points while supporting the lighting unit at three or more points along the second side different from the first side The inspection system according to claim 1. The deformation mechanism, the illumination portion, is deformed into a curved shape substantially along the uneven shape of the surface to be inspected, the inspection system according to claim 1 or 2. The inspection system according to any one of claims 1 to 3, wherein the deformation mechanism deforms the illumination unit into different shapes in accordance with portions of the plurality of inspection surfaces. The deformation mechanism, the illumination unit, when viewed from one direction into a plurality of curved surface direction of the generatrix of the deformation of the lighting unit cross each other, deforming, according to any one of claims 1-4 Inspection system. The lighting unit according to any one of claims 1 to 5 , wherein the lighting unit outputs a stripe pattern of the intensity of light spatially extending in a direction crossing the generatrix, extending along the generatrix of deformation of the lighting unit. Inspection system described in. The inspection system according to any one of claims 1 to 6 , wherein the illumination unit switches and outputs a stripe pattern of the intensity of spatially moving light extending in different directions. The lighting unit is
While having an illuminated surface that outputs a fringe pattern of the intensity of spatially moving light with different widths depending on the location,
Distribution of widths of the plurality of fringe patterns in an image captured by the imaging unit, such as the following dispersion of the width of a plurality of stripe patterns in the irradiated surface, irradiating the fringe pattern, of the claims 1-7 Inspection system according to any one. The inspection system according to any one of claims 1 to 8 , wherein the imaging unit is a time-correlated camera or an imaging system performing an operation equivalent thereto. Periodically changes in response to the time change of the light intensity based on the intensity signal of the reflected light from the inspection surface and the spatial change according to the passage of time of the light intensity given on the inspection surface A time correlation image generation unit that generates a time correlation image by an imaging system that multiplies a reference signal to
The imaging system is configured to be deformable in a curved shape that is disposed to face the inspection surface, and spatially changes light according to continuous time progress on the inspection surface. A planar illumination unit that provides continuous and periodic time change and spatial change of light intensity within one exposure time of
A deformation mechanism that deforms the illumination unit;
An arithmetic processing unit that calculates, from the time correlation image, a feature that corresponds to the distribution of the normal vector of the surface to be inspected, and detects an abnormality by at least one of the difference from the surroundings and the difference from the reference surface. When,
Inspection system equipped with. A flexible illumination device used in the inspection system according to any one of claims 1 to 10 , wherein the illumination unit is a surface-shaped illumination unit that can be deformed in a curved shape that is disposed to face the inspection surface . At least two of the three points having a plurality of support portions that support the sides of the illumination portion so that the support position can be changed, and the illumination portion is supported at three or more points along the sides of the illumination portion in the and a deformation mechanism that deforms the illumination unit by changing the position of the support portion, the flexible lighting device.

Images