JP2018105839A - Imaging device, inspection device, and imaging device control program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an imaging device, inspection device and imaging device control program that can improve an image quality of shot images.SOLUTION: An X-ray reception device as an imaging device comprises a plurality of reception elements that receives electromagnet waves from an imaging area PA. The imaging area PA is virtually partitioned into a plurality of segment areas s1 to s6 along a conveyance direction shown by an arrow AR1. The X-ray reception device is configured to shoot images of the imaging area PA using the plurality of reception elements at a timing when an object exists in the segment area s1; and extract a segment image IM11 of the segment area s1 from the image of the imaging area PA. The X-ray reception device is configured to shoot images of the imaging area PA using the plurality of reception elements at a timing when the object exists in the segment area s2; and extract a segment image IM22 of the segment area s2 from the image of the imaging area PA. The X-ray reception device is configured to: overlap at least the segment image IM11 and the segment image IM22; and output an obtained output image.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an imaging device, an inspection device, and a control program for the imaging device. More specifically, the present invention relates to an imaging device, an inspection device, and a control program for the imaging device.

  An X-ray inspection apparatus is known as an apparatus that inspects an inspection object without destroying it. In general, an X-ray inspection apparatus includes a transport unit such as a belt conveyor that transports an object to be inspected, and an X-ray generator and an imaging device (X-ray light receiving device) arranged so as to sandwich the transport path. Yes. The X-ray generator generates X-rays and irradiates the inspection object conveyed by the conveyance unit. X-rays irradiated on the inspection object pass through the inspection object and are imaged by an imaging apparatus. The X-ray inspection apparatus inspects the inside of an object to be inspected based on an image captured by an imaging apparatus.

  Patent Document 1 below discloses an X-ray light receiving device including an image intensifier, an optical lens, and a detection unit including a TDI (Time Delay Integration) camera. The detection unit includes five light receiving elements arranged in the conveyance direction of the inspection object. From the same portion of the object to be inspected, the detection unit is configured to receive each of the first row light receiving element, the second row light receiving element, the third row light receiving element, the fourth row light receiving element, and the fifth row light receiving element. The intensity distribution in the one-dimensional direction of the received light is detected by integrating the amount of received light. As a result, the amount of light received by the X-ray light receiving device is increased.

Japanese Patent Laid-Open No. 2006-145793

  In the TDI camera, electrons generated in the row of light receiving elements on the upstream side in the transport direction are sequentially moved to the row of light receiving elements on the downstream side in the transport direction, whereby the amount of received light is integrated. For this reason, the amount of received light can be increased by using a TDI camera as a detection part like patent document 1. FIG. On the other hand, when a TDI camera is used as a detector as in Patent Document 1, an amplifier is used to convert a signal into a voltage when outputting accumulated electrons as a signal from the TDI camera. Noise (random noise, white noise) due to heat received by the TDI camera from this amplifier is integrated once with the amount of received light. As a result, there was a problem that there was a lot of noise and the quality of the captured image was poor.

  The problem that the image quality of the photographed image is poor is not limited to the X-ray light receiving device that receives X-rays that have passed through the object to be inspected, but is a problem that occurs in all photographing devices that receive electromagnetic waves from the photographing region. .

  SUMMARY An advantage of some aspects of the invention is that it provides an imaging device, an inspection device, and a control program for the imaging device that can improve the quality of a captured image.

  An imaging apparatus according to one aspect of the present invention is an imaging apparatus that includes a plurality of receiving elements that receive electromagnetic waves from an imaging area, and that captures an object that moves in the imaging area in one direction. An electromagnetic wave that is virtually divided into a plurality of divided areas along one direction and is received using a plurality of receiving elements at a timing when an object is present in the first divided area among the plurality of divided areas. A first image capturing unit that captures an image of the image capturing area based on the image data; and a first extraction that extracts a first segmented image that is an image of the first segmented region from the image of the image capturing region captured by the first image capturing unit. And taking an image of an imaging region based on electromagnetic waves received using a plurality of receiving elements at a timing when an object is present in a second segmented region different from the first segmented region among the plurality of segmented regions. Second photographing means and second photographing A second extracting means for extracting a second segmented image that is an image of the second segmented region from the image of the imaged region photographed at the stage, and at least the first segmented image and the second segmented image are superimposed. The image forming apparatus further includes superimposing means and output means for outputting an output image obtained by superimposing by the superimposing means.

  Preferably, in the imaging apparatus, the superimposing unit does not superimpose an image of the imaging region captured at a timing when the object is present in the segmented regions at both ends along one direction among the plurality of segmented regions.

  Preferably, the imaging apparatus further includes focusing means for focusing electromagnetic waves from the imaging area, and each of the first and second imaging means takes an image of the imaging area based on the electromagnetic waves focused by the focusing means. .

  Preferably, in the imaging apparatus, the electromagnetic wave includes at least one of X-rays, infrared rays, and ultraviolet rays, and further includes conversion means for converting the electromagnetic waves into visible light.

  In the photographing apparatus, the conversion unit is preferably an image intensifier.

  Preferably, in the imaging apparatus, the plurality of receiving elements generate electrons corresponding to the received light, and the electrons generated by the receiving elements used for capturing the first segmented image are used for capturing the second segmented image. Does not move to the light receiving element.

  An inspection apparatus according to another aspect of the present invention includes an electromagnetic wave generation source that generates an electromagnetic wave, and any one of the imaging apparatuses described above.

  An imaging device control program according to still another aspect of the present invention includes a plurality of receiving elements that receive electromagnetic waves from an imaging region, and is an imaging device control program that images an object that moves in an imaging region. The imaging area is virtually divided into a plurality of divided areas along one direction, and a plurality of receiving elements are provided at a timing when an object is present in the first divided area among the plurality of divided areas. A first photographing step for photographing an image of a photographing region based on an electromagnetic wave received using the first image, and a first partitioned image that is an image of a first partitioned region from the image of the photographing region photographed in the first photographing step Based on electromagnetic waves received using a plurality of receiving elements at a timing when a target is present in a second segmented region different from the first segmented region among a plurality of segmented regions Shoot A second photographing step for photographing an image of the region; a second extracting step for extracting a second partitioned image that is an image of the second partitioned region from the image of the photographing region photographed in the second photographing step; The computer executes a superposition step of superposing at least the first segment image and the second segment image and an output step of outputting an output image obtained by superposition in the superposition step.

  ADVANTAGE OF THE INVENTION According to this invention, the imaging device which can improve the image quality of the image | photographed image, an inspection apparatus, and the control program of an imaging device can be provided.

It is sectional drawing which shows typically the structure of the X-ray inspection apparatus 1 in one embodiment of this invention. It is sectional drawing which shows typically the structure of the X-ray light-receiving device 10 in one embodiment of this invention. It is a top view which shows typically the structure of the detection part 40 in one embodiment of this invention. It is a 1st figure which shows typically the image which the detection part 40 image | photographs in one embodiment of this invention. It is a 2nd figure which shows typically the image which the detection part 40 image | photographs in one embodiment of this invention. It is a figure which shows typically the output image OI of the workpiece | work WK which the image generation part 83 produces | generates in one embodiment of this invention. It is a figure which shows typically the imaging conditions of the detection part 40 in one embodiment of this invention. It is a flowchart which shows operation | movement of the control part 80 in one embodiment of this invention. 2 is a diagram schematically showing the principle of a TDI camera 400. FIG. It is a figure which shows typically the output image OI of the workpiece | work WK which the image generation part 83 produces | generates in the 1st modification of one embodiment of this invention. It is a flowchart which shows operation | movement of the control part 80 in the 1st modification of one embodiment of this invention. It is a top view which shows typically the structure of the detection part 40 in the 2nd modification of one embodiment of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  [Schematic configuration of X-ray inspection apparatus]

  First, a schematic configuration of an X-ray inspection apparatus according to an embodiment of the present invention will be described.

  FIG. 1 is a cross-sectional view schematically showing a configuration of an X-ray inspection apparatus 1 according to an embodiment of the present invention. Note that the x axis, the y axis, and the z axis are orthogonal to each other.

  Referring to FIG. 1, X-ray inspection apparatus 1 (an example of an inspection apparatus) according to the present embodiment is a workpiece WK (an example of an object) that moves imaging area PA in a direction (x-axis direction) indicated by arrow AR1. Are irradiated with X-rays, and the workpiece WK is inspected based on the X-rays from the workpiece WK. The X-ray inspection apparatus 1 includes an X-ray light receiving device 10 (an example of an imaging device), a transport unit 60, an X-ray irradiation device 70 (an example of an electromagnetic wave generation source), a control unit 80, and the like.

  The X-ray irradiation device 70 generates X-rays therein and irradiates the imaging area PA with X-rays as indicated by an arrow AR2. The X-ray irradiation apparatus 70 may be a reflection type using X-rays reflected by a target (X-ray generation source) or a transmission type using X-rays transmitted through the target. Good.

  The transport unit 60 transports the workpiece WK arranged on the table 61 in the direction indicated by the arrow AR1. The conveyance part 60 consists of a belt conveyor etc., for example.

  The X-ray light receiving device 10 images the workpiece WK that moves in the imaging area PA. As indicated by an arrow AR3, the X-ray light receiving device 10 receives X-rays that have passed through the imaging area PA (X-rays that have passed through the workpiece WK), and transmits a signal indicating the intensity of the received X-rays to the control unit 80. To do.

  The control unit 80 is electrically connected to each of the X-ray light receiving device 10, the transport unit 60, and the X-ray irradiation device 70, and controls the entire X-ray inspection apparatus 1. The control unit 80 is, for example, a PC (Personal Computer), a CPU (Central Processing Unit) that operates based on a control program, a ROM (Read Only Memory) that stores the control program, and a RAM that is a work area of the CPU ( Random Access Memory). The control unit 80 includes an X-ray generation control unit 81, a table control unit 82, an image generation unit 83, a display unit 84, and an operation unit 85.

  The X-ray generation control unit 81 controls X-rays generated from the X-ray irradiation apparatus 70 by controlling a voltage applied to the X-ray irradiation apparatus 70 and the like.

  The table control unit 82 controls the movement of the table 61 by the transport unit 60.

  The image generation unit 83 generates an image based on the signal received from the X-ray light receiving device 10 and displays the image on the display unit 84. The image generation unit 83 controls the voltage, timing, clock, and the like applied to the X-ray light receiving device 10.

  The display unit 84 displays various information.

  The operation unit 85 accepts various operations.

  Since the position of the work WK moves in the direction indicated by the arrow AR1 with the passage of time, the position at which the X-ray passes through the work WK also moves in the direction indicated by the arrow AR1 with the passage of time. Therefore, the X-ray inspection apparatus 1 can inspect different positions along the arrow AR1 in the work WK with time.

  In the present specification, the moving direction of the table 61 (the direction indicated by the arrow AR1) is the positive direction of the x axis. The traveling direction of X-rays received by the X-ray light receiving device 10 (the direction indicated by the arrow AR3) is the positive z-axis direction. The x axis and the z axis are orthogonal to each other. Furthermore, the direction perpendicular to each of the x-axis and z-axis (the direction perpendicular to the paper surface) is the y-axis direction.

  FIG. 2 is a cross-sectional view schematically showing the configuration of the X-ray light receiving device 10 in one embodiment of the present invention.

  Referring to FIG. 2, the X-ray light receiving device 10 includes an image intensifier 20 (an example of a conversion unit), an optical lens 30 (an example of a focusing unit), and a detection unit 40. The image intensifier 20, the optical lens 30, and the detection unit 40 are arranged in this order along the direction away from the workpiece WK along the X-ray traveling direction (the positive direction of the z-axis indicated by the arrow AR3). Has been.

  The image intensifier 20 converts the X-rays that have passed through the imaging area PA into visible light, and multiplies the intensity of the visible light after conversion to output. The image intensifier 20 includes an input phosphor screen 21, a photocathode 22, a focusing electrode 23, an anode 24, an output phosphor screen 25, a casing 26, a focusing power source 27, and an acceleration power source 28. Yes. The focusing electrode 23, the anode 24, the focusing power source 27, and the acceleration power source 28 constitute an acceleration focusing unit and function as an electrostatic lens system.

  The housing | casing 26 has the hollow part decompressed. Inside the housing 26, an input phosphor screen 21, a photocathode 22, a focusing electrode 23, an anode 24, and an output phosphor screen 25 are arranged. The photocathode 22 is disposed close to the input phosphor screen 21 on the side farther from the workpiece WK than the input phosphor screen 21 (the z-axis positive direction side). The output phosphor screen 25 is arranged at a large distance from the photocathode 22 on the side farther from the work WK than the photocathode 22 (the positive z-axis direction side). Each of the input phosphor screen 21, the photocathode 22, and the output phosphor screen 25 extends in the x-axis direction. The focusing electrode 23 has a cylindrical shape, for example, and extends in the z-axis direction. The focusing electrode 23 is disposed between the photocathode 22 and the output phosphor screen 25. The anode 24 is disposed in the vicinity of the output phosphor screen 25. The anode 24 has a cylindrical shape, for example, and extends in the z-axis direction. The output phosphor screen 25 is disposed inside the anode 24. The focusing power supply 27 applies a voltage between the photocathode 22 and the focusing electrode 23. The acceleration power supply 28 applies a voltage between the photocathode 22 and the anode 24.

  The optical lens 30 is a convex lens, and focuses visible light output from the image intensifier 20.

  Under the control of the control unit 80, the detection unit 40 receives the visible light focused by the optical lens 30 and images the imaging area PA.

  The X-rays that have passed through the workpiece WK enter the image intensifier 20 as indicated by an arrow AR3. X-rays incident on the image intensifier 20 are converted into visible light (fluorescence) by the input phosphor screen 21. Visible light converted by the input phosphor screen 21 is converted into photoelectrons by the photocathode 22. Photoelectrons converted by the photocathode 22 are accelerated and focused by the focusing electrode 23, the anode 24, the focusing power source 27, and the acceleration power source 28. The accelerated and focused photoelectrons collide with the output phosphor screen 25 and are emitted (output) to the outside of the image intensifier 20 as visible light (fluorescence) by the output phosphor screen 25. The visible light output from the image intensifier 20 has an intensity corresponding to the intensity of X-rays incident on the image intensifier 20. Visible light output from the image intensifier 20 is focused by the optical lens 30 and enters the detection unit 40.

  FIG. 3 is a plan view schematically showing the configuration of the detection unit 40 in the embodiment of the present invention.

  Referring to FIG. 3, detection unit 40 includes a plurality of light receiving elements 41 (an example of a receiving element) and a substrate 42. The plurality of light receiving elements 41 and the substrate 42 constitute a two-dimensional camera (area camera) and can detect a two-dimensional intensity distribution of visible light. Each of the plurality of light receiving elements 41 is disposed on the substrate 42. Each of the plurality of light receiving elements 41 configures n2 columns in the x-axis direction, and each column includes n1 light receiving elements 41 arranged in the y-axis direction. The plurality of light receiving elements 41 receive visible light (that is, X-rays from the imaging area PA) focused by the optical lens 30.

  [Work shooting method]

  Next, a method for photographing the workpiece WK by the detection unit 40 in the present embodiment will be described.

  4 and 5 are diagrams schematically showing images taken by the detection unit 40 in the embodiment of the present invention. 4 and 5, the case where a workpiece WK having a planar shape of alphabet “M” is a detection target will be described. 4 and 5 show the position of the work WK that passes through the imaging area PA. The dotted line in the right diagram shows a captured image, and the solid line in the right diagram shows a segmented image extracted from the captured image. Here, a case where the cumulative number M of shooting of the workpiece WK is 6 is shown.

  Hereinafter, the upstream side (lower part in FIG. 4) of the work WK in the transport direction is referred to as a work lower part e1, and the downstream side (upper part in FIG. 4) of the work WK in the transport direction is referred to as a work upper part e3. The part between e1 and the workpiece | work upper part e3 may be described as the workpiece | work center part e2.

  Referring to FIG. 4A, the imaging area PA is virtually divided into a plurality (six here) of divided areas s1 to s6 along the conveyance direction indicated by the arrow AR1. Each of the divided regions s1 to s6 is arranged in this order along the direction indicated by the arrow AR1.

  At time T = t0, conveyance of the workpiece WK is started. When time T = t1, the work lower part e1 enters the imaging area PA and reaches the segmented area s1. Under the control of the control unit 80, the detection unit 40 obtains the image IM1 of the entire imaging area PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 exists in the divided area s1. Take a picture. The detection unit 40 transmits the captured image IM1 to the image generation unit 83.

  When receiving the image IM1, the image generation unit 83 divides the image IM1 into each of the divided images IM11 to IM16 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts the segment image IM11 corresponding to the segment area s1 from the image IM1.

  Referring to FIG. 4B, when time T = t2 after time Δt (s) from time T = t1, work lower part e1 reaches segmented region s2. The work center e2 enters the imaging area PA and reaches the segmented area s1. Under the control of the control unit 80, the detection unit 40 obtains the image IM2 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 exists in the divided region s2. Take a picture. The detection unit 40 transmits the captured image IM2 to the image generation unit 83.

  When receiving the image IM2, the image generation unit 83 divides the image IM2 into each of the divided images IM21 to IM26 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM21 corresponding to the partitioned region s1 and a partitioned image IM22 corresponding to the partitioned region s2 from the image IM2.

  Referring to FIG. 4C, when time T = t3 after time Δt (s) from time T = t2, workpiece lower part e1 reaches segmented region s3, and workpiece center e2 reaches segmented region s2. To do. The upper part e3 of the work enters the imaging area PA and reaches the divided area s1. Under the control of the control unit 80, the detection unit 40 obtains the image IM3 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 is present in the divided region s3. Take a picture. The detection unit 40 transmits the captured image IM3 to the image generation unit 83.

  When receiving the image IM3, the image generation unit 83 divides the image IM3 into the divided images IM31 to IM36 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM31 corresponding to the partitioned region s1, a partitioned image IM32 corresponding to the partitioned region s2, and a partitioned image IM33 corresponding to the partitioned region s3 from the image IM3.

  Referring to FIG. 4D, when time T = t4 after time Δt (s) from time T = t3, the work lower part e1 reaches the sorting area s4, and the work center part e2 reaches the sorting area s3. Then, the workpiece upper part e3 reaches the divided area s2. Under the control of the control unit 80, the detection unit 40 obtains an image IM4 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 is present in the divided region s4. Take a picture. The detection unit 40 transmits the captured image IM4 to the image generation unit 83.

  When receiving the image IM4, the image generation unit 83 divides the image IM4 into each of the divided images IM41 to IM46 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM42 corresponding to the partitioned region s2, a partitioned image IM43 corresponding to the partitioned region s3, and a partitioned image IM44 corresponding to the partitioned region s4 from the image IM4.

  Referring to FIG. 5A, when time T = t5 after time Δt (s) from time T = t4, the work lower part e1 reaches the sorting area s5, and the work center e2 reaches the sorting area s4. Then, the workpiece upper part e3 reaches the divided area s3. Under the control of the control unit 80, the detection unit 40 obtains the image IM5 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 exists in the divided region s5. Take a picture. The detection unit 40 transmits the captured image IM5 to the image generation unit 83.

  When receiving the image IM5, the image generation unit 83 divides the image IM5 into each of the divided images IM51 to IM56 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM53 corresponding to the partitioned region s3, a partitioned image IM54 corresponding to the partitioned region s4, and a partitioned image IM55 corresponding to the partitioned region s5 from the image IM5.

  Referring to FIG. 5B, when time T = t6 after time Δt (s) from time T = t5, the work lower part e1 reaches the sorting area s6, and the work center e2 reaches the sorting area s5. Then, the workpiece upper part e3 reaches the divided area s4. Under the control of the control unit 80, the detection unit 40 obtains an image IM6 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the work lower part e1 is present in the divided region s6. Take a picture. The detection unit 40 transmits the captured image IM6 to the image generation unit 83.

  When receiving the image IM6, the image generation unit 83 divides the image IM6 into each of the divided images IM61 to IM66 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM64 corresponding to the partitioned region s4, a partitioned image IM65 corresponding to the partitioned region s5, and a partitioned image IM66 corresponding to the partitioned region s6 from the image IM6.

  Referring to FIG. 5C, when time T = t7 after time Δt (s) from time T = t6, the work lower part e1 deviates from the imaging area PA, and the work center part e2 reaches the section area s6. The work upper part e3 reaches the section area s5. Under the control of the control unit 80, the detection unit 40 detects the image IM7 of the entire imaging area PA based on the light received using the plurality of light receiving elements 41 at the timing when the work center part e2 is present in the divided area s6. Shoot. The detection unit 40 transmits the captured image IM7 to the image generation unit 83.

  When receiving the image IM7, the image generation unit 83 divides the image IM7 into each of the divided images IM71 to IM76 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a partitioned image IM75 corresponding to the partitioned region s5 and a partitioned image IM76 corresponding to the partitioned region s6 from the image IM7.

  Referring to FIG. 5D, when time T = t8 after time Δt (s) from time T = t7, the work center part e2 deviates from the imaging area PA, and the work upper part e3 reaches the divided area s6. . Under the control of the control unit 80, the detection unit 40 obtains the image IM8 of the entire imaging region PA based on the light received using the plurality of light receiving elements 41 at the timing when the workpiece upper part e3 is present in the divided region s6. Take a picture. The detection unit 40 transmits the captured image IM8 to the image generation unit 83.

  When receiving the image IM8, the image generation unit 83 divides the image IM8 into each of the divided images IM81 to IM86 corresponding to the divided regions s1 to s6. Then, the image generation unit 83 extracts a segment image IM86 corresponding to the segment area s6 from the image IM8.

  FIG. 6 is a diagram schematically showing an output image OI of the work WK generated by the image generation unit 83 in the embodiment of the present invention.

  Referring to FIG. 6, the image generation unit 83 sequentially superimposes the extracted segmented images on one of the segmented images extracted from the image captured at the next timing, for a total of six images. The segmented images are overlaid. Then, the image generation unit 83 combines the superimposed images of the workpiece lower portion e1, the workpiece central portion e2, and the workpiece upper portion e3 in the conveyance direction of the workpiece WK. Thereby, an output image is generated.

  Specifically, the image generation unit 83 includes a segmented image IM11 (captured at T = t1), a segmented image IM22 (captured at T = t2), a segmented image IM33 (captured at T = t3), and a segmented image IM44. The output image OI of the work lower part e1 is generated by superimposing the segmented image IM55 (captured at T = t5) and the segmented image IM66 (captured at T = t6).

  Similarly, the image generation unit 83 includes a segmented image IM21 (captured at T = t2), a segmented image IM32 (captured at T = t3), a segmented image IM43 (captured at T = t4), and a segmented image IM54 (T = Photographed at t5), the segmented image IM65 (photographed at T = t6), and the segmented image IM76 (photographed at T = t7) are overlapped to generate the output image OI of the work center e2.

  Similarly, the image generation unit 83 includes a segmented image IM31 (captured at T = t3), a segmented image IM42 (captured at T = t4), a segmented image IM53 (captured at T = t5), and a segmented image IM64 (T = Photographed at t6), the segmented image IM75 (photographed at T = t7) and the segmented image IM86 (photographed at T = t8) are overlapped to generate an output image OI of the workpiece upper part e3. The image generation unit 83 displays (outputs) the generated output image OI on the display unit 84.

  FIG. 7 is a diagram schematically showing imaging conditions of the detection unit 40 in the embodiment of the present invention. FIG. 7A is a diagram illustrating the imaging area PA, and FIG. 7B is a diagram illustrating the detection unit 40.

  Referring to FIG. 7, the speed V (mm / s) of the image of the workpiece WK passing over the light receiving element 41, the length L1 (mm) in the y-axis direction of the imaging area PA, and the x-axis direction of the imaging area PA. Length L2 (mm), the number n1 (number) of light receiving elements 41 arranged in the y-axis direction, the number n2 (number) of light receiving elements 41 arranged in the x-axis direction, and the number of photographing per unit time of the detection unit 40 (Frame rate) C (times / s) is a variable and can be set freely. Further, by appropriately setting these variables, the number of integrations M can be set to an arbitrary value as follows. The image speed V (mm / s) of the workpiece WK is a value defined as the product of the conveyance speed (mm / s) of the workpiece WK by the table 61 and the magnification of the optical lens 30.

  Since the movement amount of the workpiece WK per frame is expressed as “V / C (= V × Δt) (mm)”, the number of times M of the workpiece WK is shot is “M = L2 / (V / C ) = (L2 × C) / V (times) ”.

  From the above equation, it can be seen that the number of integrations M of the output image OI and the speed V of the image of the work WK are in a trade-off relationship. That is, if the speed V of the image of the work WK is decreased, the light quantity of the output image OI can be increased by increasing the number of integrations M, and a high-quality output image can be obtained. On the other hand, if the number of times of integration M is decreased, the imaging speed can be increased by increasing the speed V of the image of the work WK. Further, when the frame rate C is increased, a high-quality output image OI can be obtained by increasing the number of integrations M.

  Further, since the number of light receiving elements existing per 1 mm in the conveyance direction of the work WK is expressed as “n2 / L2 (pieces)”, the number of the light receiving elements arranged in the conveyance direction in the light receiving element that captures one segmented image. The number N (pieces) is expressed as “N = (V / C) × (n2 / L2) = (V × n2) / (C × L2) (pieces)”.

  FIG. 8 is a flowchart showing the operation of the control unit 80 according to the embodiment of the present invention. Note that FIG. 8 shows an operation when generating an output image for one segmented region.

  Referring to FIG. 8, when the conveyance of the workpiece WK is started, the control unit 80 sets the number of shootings k to 1 (S101), and determines whether or not the time Δt has elapsed since the previous shooting (S103). . The controller 80 repeats the process of step S103 until it is determined that the time Δt has elapsed.

  If it is determined in step S103 that the time Δt has elapsed since the previous shooting (YES in S103), the control unit 80 takes an image of the shooting area (S105), and divides the taken image into segmented images (S107). ). Subsequently, the control unit 80 extracts a segmented image corresponding to the kth segmented region from the upstream side in the transport direction from the segmented segmented images (S109), and determines whether there is a superimposed image (S111). ).

  If it is determined in step S111 that there is no superimposed image (NO in S111), the control unit 80 sets the extracted segmented image as a superimposed image (S113), and proceeds to the process of step S117.

  If it is determined in step S111 that there is a superimposed image (YES in S111), the control unit 80 superimposes the extracted segmented image on the superimposed image (S115), and proceeds to the process of step S117.

  In step S117, the control unit 80 determines whether or not the number of shootings k has reached the number of integrations M (S117).

  If it is determined in step S117 that the number of shootings k does not reach the number of integrations M (NO in S117), the control unit 80 increments the number of shootings k (S119), and proceeds to the process of step S103.

  If it is determined in step S117 that the number of shootings k has reached the number of integrations M (YES in S117), the control unit 80 outputs the superimposed image as an output image (S121) and ends the process.

  Next, the effect of this embodiment will be described.

  FIG. 9 is a diagram schematically showing the principle of the TDI camera 400.

  Referring to FIG. 9, TDI camera 400 includes n light receiving element rows LN <b> 1 to LNn arranged in the workpiece conveyance direction indicated by arrow AR <b> 11. The row LN1 arranged on the most upstream side in the transport direction receives light from the workpiece when the workpiece passes through the corresponding detection region, and electrons corresponding to the light amount are generated in the row LN1. The electrons present in the column LN1 are moved to the adjacent downstream column LN2.

  The column LN2 receives light from the workpiece when the workpiece passes through the corresponding detection area, and electrons corresponding to the amount of light are generated in the column LN2. Electrons present in column LN2 are moved to adjacent downstream column LN3.

  In this way, the electrons generated in the rows LN1 to LNn sequentially move LN1 to LNn toward the downstream side in the transport direction, and finally accumulate in the row LNn. The electrons accumulated in the column LNn are amplified by an amplifier (not shown) and detected by a detector.

  In the TDI camera 400, the electrons generated in each of the light receiving element columns LN1 to LNn reflect noise included in the light received by each of the light receiving element columns LN1 to LNn, and therefore exist in the column LNn. The image represented by the electrons is obtained by integrating noise caused by heat received by the TDI camera 400 from the amplifier generated in each row of the light receiving elements. As a result, there is a problem that there is a lot of noise and the quality of the captured image is poor.

  In the present embodiment, the plurality of light receiving elements 41 generate electrons corresponding to the received light, similarly to the light receiving elements of the TDI camera. Each segmented image includes various noises caused by fluctuations in amplifiers and X-rays, conversion efficiency of the scintillator, fluctuations included in the received light, and the like. However, in the present embodiment, electrons generated in the light receiving element 41 used for capturing one segmented image do not move to the light receiving elements used for capturing another segmented image. For this reason, the noise of each divided image is not integrated. In the present embodiment, by overlapping a plurality of segmented images, noise generated in each segmented image is canceled out, so that the S / N ratio of the output image can be improved. As a result, the image quality of the captured image can be improved. Further, by superimposing a plurality of segmented images, the amount of light in the output image can be increased and the captured image can be brightened.

  In addition, by switching the usage method of the X-ray light receiving device 10 between the usage method of overlapping the segment images in the present embodiment and the normal usage method of using the image captured without overlaying the segment images as they are. The state of the workpiece WK can be inspected using both an output image generated by superimposing the segmented images and an image (still image) captured by a normal method.

  Furthermore, compared to a conventional line camera, even when a workpiece moving at a high speed is photographed, the amount of light can be increased while the afterimage is suppressed, and the quality of the photographed image can be improved.

  [Modification]

  FIG. 10 is a diagram schematically showing an output image OI of the work WK generated by the image generation unit 83 in the first modification of the embodiment of the present invention.

  4, 5, and 10, the divided areas s <b> 1 and s <b> 6 are located at both ends along the conveyance direction indicated by the arrow AR <b> 1 in the imaging area PA. In the present modification, the image generation unit 83 does not superimpose images of the shooting area PA that are shot at timings that exist in the divided areas s1 and s6 among the multiple divided areas s1 to s6.

  Specifically, when generating the output image of the workpiece lower part e1, the image generation unit 83 generates the divided image IM66 of the image IM1 (taken at T = t1) and the image IM6 (taken at T = t6) of the image IM1. Do not extract. The image generation unit 83 includes a segmented image IM22 (captured at T = t2), a segmented image IM33 (captured at T = t3), a segmented image IM44 (captured at T = t4), and a segmented image IM55 (captured at T = t5). The output image OI of the lower part e1 of the workpiece is generated by superimposing the (shooting).

  Similarly, when generating the output image of the work center part e2, the image generation unit 83 generates the segment image IM21 (captured at T = t2) of the image IM2 and the segment image IM76 (captured at T = t7) of the image IM7. Do not extract. The image generation unit 83 includes a segmented image IM32 (captured at T = t3), a segmented image IM43 (captured at T = t4), a segmented image IM54 (captured at T = t5), and a segmented image IM65 (captured at T = t6). The output image OI of the work center part e2 is generated by superimposing the (photographing).

  Similarly, when generating the output image of the workpiece upper part e3, the image generation unit 83 extracts the segment image IM31 (captured at T = t3) of the image IM3 and the segment image IM86 of the image IM8 (captured at T = t8). do not do. The image generating unit 83 includes a segmented image IM42 (captured at T = t4), a segmented image IM53 (captured at T = t5), a segmented image IM64 (captured at T = t6), and a segmented image IM75 (captured at T = t7). The output image OI of the workpiece upper part e3 is generated.

  FIG. 11 is a flowchart showing the operation of the control unit 80 in the first modification of the embodiment of the present invention. Note that FIG. 11 shows an operation when generating an output image for one segmented region.

  Referring to FIG. 11, in the present modification, control unit 80 performs steps S <b> 101 to S <b> 107 in the flowchart shown in FIG. 8. In step S107, after dividing the photographed image into segmented images, the control unit 80 determines whether the number of photographing times k is 1 or M (S201).

  In step S201, when it is determined that the number of shootings k is 1 or M (YES in S201), the control unit 80 is a timing at which the object is positioned in the divided areas at both ends along the conveyance direction of the workpiece WK. Judge. The control unit 80 does not extract the kth segment image (S203), and proceeds to the process of step S117.

  When it is determined in step S201 that the number of times of photographing k is not 1 and M (NO in S201), the control unit 80 is not at a timing when the object is positioned in the divided regions at both ends along the conveyance direction of the workpiece WK. Judge. The control unit 80 extracts the kth segment image (S109), and proceeds to the process of step S111.

  As shown in FIG. 2, the light from the imaging area PA is usually focused by a condensing unit such as an optical lens 30 and enters the detection unit 40. Thereby, more light can be received by the detection unit 40. On the other hand, since the light received by the detection unit 40 is focused by the optical lens 30 or the like, distortion occurs in the image formed by the light received by the detection unit 40. This distortion is particularly noticeable at the end of the imaging area PA.

  According to the present modification, the images of the photographing area PA photographed at the timings present in the divided areas s1 and s6 at both ends along the conveyance direction of the work WK in the photographing area PA are not overlapped. The influence of image distortion on the output image OI can be reduced. As a result, the image quality of the captured image can be improved.

  FIG. 12 is a plan view schematically showing the configuration of the detection unit 40 in the second modification of the embodiment of the present invention.

  Referring to FIG. 12, in the present modification, detection unit 40 captures a plurality of segment images and transmits them to image generation unit 83, and image generation unit 83 superimposes the plurality of segment images received from detection unit 40. .

  The detection unit 40 in the present modification further includes a scanning circuit 43 and a plurality of amplifiers 44a to 44l. The plurality of light receiving elements 41 include n2 (in this case, 12) light receiving element rows 40a to 40l arranged in the x-axis direction. Each of the plurality of light receiving element arrays 40a to 40l is configured by n1 light receiving elements 41 arranged in the y-axis direction. Each of the plurality of light receiving element arrays 40a to 40l is connected to the image generation unit 83 via the x-axis direction scanning circuit 43 and each of the plurality of amplifiers 44a to 44l. The scanning circuit 43 is made of, for example, an FPGA (Field-Programmable Gate Array).

  The plurality of light receiving element arrays 40 a to 40 l capture an image of the imaging area PA and transmit data of the captured image to the scanning circuit 43. The scanning circuit 43 creates segmented images corresponding to the segmented regions s1 to s6 shown in FIG. 4 based on the image data received from the plurality of light receiving element arrays 40a to 40l.

  Specifically, the scanning circuit 43 creates a segmented image corresponding to the segmented region s1 based on the image data received from the light receiving element arrays 40a and 40b, and converts the image data received from the light receiving element arrays 40c and 40d into the image data. Based on the image data received from the light receiving element rows 40e and 40f, the divided image corresponding to the divided area s3 is created based on the image data received from the light receiving element rows 40g and 40h. A segmented image corresponding to the segmented region s4 is created based on the image data, a segmented image corresponding to the segmented region s5 is created based on the image data received from the light receiving element rows 40i and 40j, and the light receiving element row 40k and Based on the image data received from 40l, a partitioned image corresponding to the partitioned region s6 is created.

  The scanning circuit 43 transmits the created segmented image data to the image generation unit 83. Each of the segmented image data is amplified by any one of the amplifiers 44a to 44l.

  For example, when generating the output image of the workpiece lower part e1, the image generation unit 83 captures the segment image IM11 taken by the light receiving element rows 40a and 40b at time T = t1, and the light receiving element rows 40c and 40d at time T = t2. , A segmented image IM33 captured by the light receiving element arrays 40e and 40f at time T = t3, a segmented image IM44 captured by the light receiving element arrays 40g and 40h at time T = t4, and a time T = t5. Then, the segment image IM55 captured by the light receiving element arrays 40i and 40j and the segment image IM66 captured by the light receiving element arrays 40k and 40l at time T = t6 are overlapped to generate the output image OI of the work lower part e1. The output images OI of the work center part e2 and the work upper part e3 are also output in the same manner.

  The number of segmented areas in the imaging area PA (in other words, the number of segmented images created by the scanning circuit 43 based on the image of one imaging area PA) is changed by the setting that the image generation unit 83 performs on the scanning circuit 43. Is possible.

  According to this modification, the clock frequency of the detector 40 can be lowered.

  That is, the number of light receiving elements 41 arranged in the y-axis direction in the entire detector 40 is n1 (pieces), and the number of light receiving elements 41 arranged in the x-axis direction (in other words, the number of light receiving element arrays) is n2 (pieces). ), And the number of times of photographing per unit time (frame rate) of the detection unit 40 is C (times / s), the entire detector 40 (when the detection unit 40 is not divided into a plurality of light receiving element arrays). ) The pixel clock (number of pixels drawn per second) is expressed as “n1 × n2 × C (Hz)”.

  On the other hand, the pixel clock when the shooting area PA is divided into k (piece) divided areas as in the present modification is represented as “n1 × n2 × C / k (Hz)”. Therefore, the clock frequency decreases as the number of segmented regions increases. As an example, n1 is 1000 (pieces), n2 is 500 (pieces), and C is 280 (times / s).

  As described above, since the clock frequency of the detector 40 can be lowered, generation of high frequency noise and heat generation of the light receiving element 41 can be suppressed. As a result, noise included in the output image can be reduced, and the life of the detection unit 40 can be increased.

  [Others]

  The imaging device of the present invention only needs to be provided with a plurality of receiving elements that receive electromagnetic waves from the imaging region and image an object that moves in the imaging region in one direction. The electromagnetic wave received from the imaging region may be not only X-rays but also visible light, infrared light, or ultraviolet light. In particular, when the electromagnetic wave received by the imaging apparatus from the imaging area is visible light or the like, the imaging apparatus may receive light reflected by the object instead of light transmitted through the object.

  In the present invention, when the electromagnetic wave received from the imaging region contains at least one of X-rays, infrared rays, and ultraviolet rays, the imaging apparatus converts the electromagnetic waves into visible light (in the above-described embodiment, An image intensifier is preferably provided. In addition, instead of providing an image intensifier, the imaging device is a scintillator that emits fluorescence upon incidence of radiation, an optical filter that selectively transmits a wavelength, or converts the wavelength of incident light to another wavelength and outputs light. A wavelength converter or the like may be provided. Furthermore, the imaging apparatus may have a structure having both a function of focusing electromagnetic waves and a function of adjusting the wavelength of electromagnetic waves by fixing them to the lens.

  In the above-described embodiment, the case where the image speed V of the work WK and the number of integrations M of the output image OI satisfy a predetermined relationship has been described. However, in the photographing apparatus of the present invention, the work WK is at an arbitrary speed V. When passing through the shooting area PA, shooting is performed an arbitrary number of times M, and a section image of the work WK is extracted from each of the plurality of captured images using a technique such as feature extraction, and the plurality of section images extracted are extracted. You may superimpose.

  The above-described embodiments and modifications can be combined as appropriate.

  The processing in the above-described embodiment may be performed by software or by using a hardware circuit. It is also possible to provide a program for executing the processing in the above-described embodiment, and record the program on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, or a memory card and provide it to the user. You may decide to do it. The program is executed by a computer such as a CPU. The program may be downloaded to the apparatus via a communication line such as the Internet.

  The above-described embodiment is to be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

DESCRIPTION OF SYMBOLS 1 X-ray inspection apparatus 10 X-ray light-receiving device 20 Image intensifier 21 Input fluorescent screen 22 Photoelectric surface 23 Focusing electrode 24 Anode 25 Output fluorescent screen 26 Case 27 Focusing power supply 28 Acceleration power supply 30 Optical lens 40 Detection part 40a-40l Image Element array 41 Light receiving element 42 Substrate 43 Scanning circuit 44a to 44l Amplifier 60 Transport unit 61 Table 70 X-ray irradiation device 80 Control unit 81 X-ray generation control unit 82 Table control unit 83 Image generation unit 84 Display unit 85 Operation unit 400 TDI ( Time Delay Integration) Camera e1 Work bottom e2 Work center e3 Work top IM1 to IM8 Images IM11 to IM16, IM21 to IM26, IM31 to IM36, IM41 to IM46, IM51 to IM56, IM61 to IM66, IM71 M76, column OI output image PA imaging area s1~s6 segmented region WK work IM81~IM86 segmented image LN1~LNn receiving element

Claims (8)

An imaging apparatus comprising a plurality of receiving elements for receiving electromagnetic waves from an imaging area, and imaging an object moving in one direction in the imaging area,
The shooting area is virtually divided into a plurality of divided areas along the one direction,
First imaging means for capturing an image of the imaging region based on the electromagnetic wave received using the plurality of receiving elements at a timing when the object is present in a first partitioned region of the plurality of partitioned regions; ,
First extraction means for extracting a first segmented image that is an image of the first segmented region from an image of the imaged region captured by the first imaging unit;
An image of the imaging region based on the electromagnetic wave received using the plurality of receiving elements at a timing when the object is present in a second segmented region different from the first segmented region among the plurality of segmented regions. A second photographing means for photographing
Second extraction means for extracting a second segmented image that is an image of the second segmented region from an image of the imaging region captured by the second imaging unit;
Superimposing means for superimposing at least the first segmented image and the second segmented image;
An imaging apparatus, further comprising output means for outputting an output image obtained by superimposing by the superimposing means.   The superimposing unit does not superimpose an image of the imaging region captured at a timing when the object is present in a segmented region at both ends along the one direction among the plurality of segmented regions. The imaging device described. A focusing means for focusing the electromagnetic wave from the imaging region;
3. The photographing apparatus according to claim 1, wherein each of the first and second photographing units photographs an image of the photographing region based on the electromagnetic wave focused by the focusing unit. The electromagnetic wave includes at least one of X-rays, infrared rays, and ultraviolet rays,
The imaging device according to claim 1, further comprising a conversion unit that converts the electromagnetic wave into visible light.   The photographing apparatus according to claim 4, wherein the conversion unit is an image intensifier. The plurality of receiving elements generate electrons according to the received light,
The imaging device according to claim 1, wherein electrons generated in a receiving element used for capturing the first segmented image do not move to a light receiving element used for capturing the second segmented image. An electromagnetic wave generating source for generating the electromagnetic wave;
An inspection apparatus comprising the imaging apparatus according to claim 1. A control program for an imaging apparatus that includes a plurality of receiving elements that receive electromagnetic waves from an imaging area, and that captures an object that moves in the imaging area in one direction,
The shooting area is virtually divided into a plurality of divided areas along the one direction,
A first photographing step of photographing an image of the photographing region based on the electromagnetic wave received using the plurality of receiving elements at a timing when the object is present in a first partitioned region of the plurality of partitioned regions; ,
A first extraction step of extracting a first segmented image that is an image of the first segmented region from an image of the imaged region captured in the first capturing step;
An image of the imaging region based on the electromagnetic wave received using the plurality of receiving elements at a timing when the object is present in a second segmented region different from the first segmented region among the plurality of segmented regions. A second shooting step for shooting
A second extraction step of extracting a second segmented image that is an image of the second segmented region from the image of the imaged region captured in the second imaging step;
A superposition step of superposing at least the first segment image and the second segment image;
An imaging device control program that causes a computer to execute an output step of outputting an output image obtained by superposition in the superposition step.

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