JP2010145253A - Method for imaging cylindrical surface and obtaining rectangular plane image - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for imaging a cylindrical surface and obtaining a rectangular plane image which obtains a normal rectangular image without distortion in an extended state. <P>SOLUTION: A scanning apparatus is accelerated, runs at a fixed speed, is decelerated, and stops during a scanning movement. In imaging data at an acceleration region, the imaging data at an end of a fixed speed region are considered as a start point. The imaging data at one probe attainable position are selected among positions approximate to each allocated position when it is allocated at a pitch interval at the probe attainable position in the fixed speed region in the direction of the acceleration of 0. In the imaging data at a deceleration region, the imaging data at an end of the fixed speed region which is a border of the deceleration region are considered as the start point. The imaging data at one probe attainable position are selected among the positions approximate to each allocated position when the data are allocated at the pitch interval at the probe attainable position in the fixed speed region in the direction of the deceleration and the stop. The rectangular plane image is obtained by vertically aligning the selected imaging data during the acceleration, the obtained imaging data during the fixed speed, and the selected imaging data during the deceleration in imaging order. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for photographing a cylinder surface and obtaining a square planar image, and is applied to, for example, a surface inspection for detecting whether there are scratches, dents, or the like on internal and external surfaces of a female screw or a male screw. The present invention relates to a method for capturing a square plane image by photographing a cylinder surface.

  For example, it is required to automatically inspect for scratches on the inner peripheral surface or foreign matters on the surface of a cylindrical shape such as an engine cylinder, a brake cylinder, a compressor cylinder, and other various operating cylinders. In addition, it is required to automatically inspect whether a thread or the like is scratched on a part having a substantially cylindrical surface such as a female screw or a male screw.

  Conventionally, for example, Patent Documents 1 to 5 have been proposed as surface inspection apparatuses for inspecting an inner peripheral surface of a cylindrical inspection object. The surface inspection apparatus of Patent Document 1 includes an inspection head in which a light projecting fiber for projecting inspection light onto a cylindrical inspection object and a light receiving fiber for receiving reflected light from the inspection object are housed in a fiber holding cylinder. An optical path changing means and a condensing means for changing the optical path of the laser light as the inspection light from the light projecting fiber at a right angle from the projecting fiber while being rotated around the axis and being sent out in the axial direction and inserted into the inspection object. Irradiates the inspection object through the inner circumferential surface of the inspection object sequentially from one end to the other end in the axial direction, and receives the reflected light from the inspection object corresponding to the scanning through the receiving fiber. In this configuration, the state of the inner peripheral surface of the object to be inspected, for example, the presence or absence of a defect (such as a scratch or a foreign object) is determined based on the amount of the received reflected light.

  In the surface inspection apparatuses of Patent Document 2 and Patent Document 3, a shaft-shaped inspection head (probe) provided with a mirror (optical path changing means) at the tip is scanned and rotated by a driving mechanism, and is moved into the inspection head. The optical path of the incident inspection light is changed by a mirror, the inspection light whose optical path is changed is irradiated on the inspection object, reflected by the inspection object, and the inspection object based on the amount of the inspection light incident again into the inspection head The basic principle is the same as that of the surface inspection apparatus of Patent Document 1. In the surface inspection apparatus of Patent Document 2, all the cylinders having different inner diameters are set by setting the relationship between the distance from the sensor head to the inner surface of the cylinder through the reflecting member and the focal length of the sensor head to be constant. The surface inspection device of Patent Document 3 is configured to be able to clean and replace the mirror at low cost and easily.

  In the surface inspection apparatus of Patent Document 4, the configuration of the inspection head (probe) is slightly different, a plurality of light receiving fibers are arranged around the light projecting fiber, and the diameter of the light receiving fiber is larger than the diameter of the light projecting fiber. The reflected light of the light projected from the light source to the inner surface of the object to be inspected through the light projecting fiber is received through the light receiving fiber, and the light corresponding to the surface of the object to be inspected based on the amount of the received light. This is a configuration for generating a three-dimensional image, which can inspect minute-size defects on the surface of the object to be inspected and is not easily affected by surface roughness or dirt.

  In the surface inspection apparatus of Patent Document 5, laser light emitted from a light source and focused by a lens is passed through an optical path at the center of a moving body and a rotating body, and the optical path is changed by 90 ° with a mirror provided in the rotating body. The reflected light is received by a number of optical fibers arranged in parallel around the optical path of the laser light that rotates with the rotating body, and further transmitted to the optical fiber on the fixed side. In this configuration, light passing through the fiber is detected by a photodetector to detect a surface flaw on the surface to be inspected.

  In any of the in-pipe surface flaw inspection apparatuses of Patent Documents 1 to 5, the probe of the imaging apparatus is kept facing the surface to be inspected (inner peripheral surface), the probe is scanned and rotated, and the probe is scanned in the axial direction. In this configuration, imaging of one round of the surface to be inspected is performed at regular intervals, and a rectangular planar image is obtained by arranging the images of each round in the order of imaging.

JP-A-11-281582 JP 2005-164398 A JP 2007-315821 A JP 2007-147324 A JP 2005-140679 A

  The present inventors cut a female screw into a bottomed hole by a method of photographing a cylindrical surface and acquiring a rectangular planar image on the basis of the photographing principle substantially the same as that of the in-pipe surface flaw inspection apparatus of Patent Documents 1 to 5. An attempt was made to inspect at high speed whether there were any scratches or foreign objects on the surface of the internal thread of the cylindrical body.

  The inspection is performed by precisely aligning the center of rotation of the inspection head with the center of the hole in the cylindrical body, and rotating the inspection head (probe) at 3000 rpm to position the inlet in the hole in the cylindrical body. The inspection head that is used for photographing can be stopped by scanning and moving to the back of the hole with a 0.1 mm width as a feed pitch per revolution, thereby photographing the cylinder surface and obtaining a rectangular planar image. As a result, the image was distorted into a stretched state near the upper end and near the lower end of the rectangular planar image.

  By changing the conditions, the inspection head is rotated at 30000 rpm and positioned at the entrance of the hole in the cylindrical body. From here, the 0.1 mm width is scanned and moved to the back of the hole as a feed pitch per rotation. When stopped, the surface of the cylinder was photographed to obtain a square planar image and displayed on the display device. As a result, the image was distorted into a more prominent extension near the upper and lower ends of the rectangular planar image.

When the present inventors have eagerly searched for the cause, in the case of the above-described test inspection, regarding the scanning movement of the inspection head, one round is photographed at a constant time with a width of 0.1 mm as a feed pitch per rotation. In the test and inspection described above, the acceleration region until the probe starts scanning movement and accelerates to a constant speed and the deceleration region where the scanning movement of the probe changes from constant speed to deceleration and stops are respectively constant. Since the number of shots is increased compared to the speed region, and all the captured line image data is displayed on the display device in the order of shooting, it is more prominent near the upper end and lower end of the rectangular planar image. It was found that the image was distorted in a stretched state. In addition, the faster the scanning rotation of the inspection head, the more time is required for the acceleration and deceleration areas, thereby increasing the number of times of shooting compared to the constant speed area, and thus the vicinity of the top and bottom edges of the rectangular planar image. It was found that the image was distorted into a more prominent state in the vicinity.
In order to improve productivity, high-speed surface inspection is required for mass-produced products such as female screws and male screws.

  The present invention has been devised in view of the above-mentioned points. The object of the present invention relates to the scanning movement of the inspection head, and the scanning movement with either acceleration on the front side of the constant speed movement and deceleration on the rear side. Even when a square image is obtained by shooting at high speed, it is possible to obtain a normal square image that does not cause distortion that causes the image to expand on the shooting start side and shooting end side of the square image obtained by shooting. An object of the present invention is to provide a method for capturing a surface and acquiring a rectangular planar image.

  In order to solve the above-described problem, according to the first invention of the present application, a method for photographing a cylindrical surface and obtaining a rectangular planar image is obtained by determining the light incident / incident direction of the tip of the probe of the image photographing device as the inner periphery of the subject. The distance between the probe and the inner peripheral surface or outer peripheral surface of the object to be imaged is suppressed by suppressing the swinging of the probe or the object to be imaged while keeping the surface facing the surface or the outer peripheral surface. A scanning rotation that can be kept constant is relatively given, a scanning movement is relatively given to one of the probe and the subject, and the scanning movement is a constant speed rotation. The scanning movement per rotation is made to coincide with the imaging width of the probe in the scanning movement direction, and the intensity of the reflected light input to the probe by irradiating the probe with the inspection light from the probe on the inner or outer peripheral surface of the subject. Convert the pixel to digital When the probe moves by a distance equal to the imaging width in the scanning movement direction per rotation with the scanning movement set at a constant speed, the imaging for acquiring the data is made one round from the origin position in the scanning rotation direction. And the required shooting area on the inner or outer peripheral surface of the object to be shot, the shooting data is stored in the memory, and the shooting data for each round is arranged in the vertical direction in the shooting order as a line image. A method for acquiring a rectangular planar image, a method for acquiring a rectangular planar image by capturing a cylindrical surface, wherein the imaging of the imaging start side portion of the imaging area on the inner peripheral surface or outer peripheral surface of the subject is accelerated. When there is a scanning movement that stops at a constant speed and decelerates, the photographing data that is shot in the acceleration area of the scanning movement and stored in the memory is shot in the constant speed area and stored in the memory. In the shadow data, at the position closest to each allocation position when allocating at the pitch interval of the probe arrival position in the constant speed area in the direction of zero acceleration starting from the imaging data at the boundary with the acceleration area The imaging data at a certain probe arrival position is selected, and the imaging data captured in the deceleration area of the scanning movement and stored in the memory is captured in the constant speed area and stored in the memory. 1 which is the closest to each allocation position when it is allocated at the pitch interval of the probe arrival position in the constant speed area in the direction of decelerating and stopping with the imaging data at the end bordering the deceleration area as the starting point The imaging data at the two probe arrival positions are selected, the selected imaging data at the time of acceleration, the imaging data acquired at the constant speed, and the selected imaging data at the time of deceleration. The rectangular planar images are obtained by arranging them in the vertical direction in the shooting order.

  In order to obtain the starting point of the imaging data at the end bordering the acceleration area or the deceleration area, or to allocate it at the pitch interval of the probe arrival position in the constant speed area, the probe arrival position in the scanning movement direction at the start of imaging every rotation Is recorded in association with imaging data, the interval between the probe arrival positions in the constant speed region is obtained, and processing is performed based on this interval.

  The first invention of the present application having the above configuration acquires the line image data by causing the scanning movement of the probe of the image photographing apparatus to perform scanning movement accompanied by acceleration on the photographing start side and deceleration on the photographing end side, A rectangular planar image is acquired. Since the acceleration region and the deceleration region are configured to perform correction, it is possible to remove the distortion in which the image extends.

  As a specific example involving acceleration at the front side of the constant speed scanning movement and deceleration at the rear side, for example, the object to be imaged has a female screw whose upper end is open and whose lower side is closed, and the female screw is photographed and square image data is taken. Applicable when you want to get

  More specifically, the probe of the image capturing apparatus is positioned above the object to be scanned, for example, in a range of 3000 rpm to 30000 rpm and starts to descend accurately, starts to descend, and moves in the middle of descending. When the origin position of the direction is detected and the actual stroke of the probe is further measured from this position and further descends and the imaging start position near the entrance in the hole of the subject is reached, the scanning movement (downward movement) is stopped once. At this time, it is assumed that the rotation center of the probe and the center of the hole of the object to be photographed exactly coincide with each other and the probe does not swing. From this point, the scanning movement (lowering) is resumed and imaging is started at the same time, and the line image data obtained per rotation and the arrival position of the actual stroke of the probe are related and stored in the memory. When it is detected by measuring the actual stroke that the imaging position of the tip of the probe has come to the lower end of the female screw, imaging and memory storage are stopped, and scanning movement is stopped.

  When the scanning movement, imaging, and memory storage of the probe are performed as described above, there is an acceleration area in which imaging is performed in front of the constant speed scanning movement, and deceleration in which imaging is performed after the constant speed scanning movement. The line image data obtained by photographing has an area, and the elapsed time per rotation at acceleration is longer than the elapsed time per revolution at constant speed, so the number of times of imaging in the acceleration area and the deceleration area is constant. More than the number of shots.

Therefore, in the first invention of the present application, the shooting data captured in the acceleration region of the scanning movement and stored in the memory is the boundary between the acceleration region in the shooting data captured in the constant speed region and stored in the memory. The position closest to each allocation position (specifically, 75% or more (preferably 80% or more preferably) when allocated at the pitch interval of the probe arrival position in the constant speed region in the direction of zero acceleration starting from the imaging data of The imaging data of one probe arrival position at the position approximated at a ratio of% or more) is selected.
In addition, for the shooting data shot in the deceleration area of scanning movement and stored in the memory, the shooting data at the boundary with the deceleration area in the shooting data shot in the constant speed area and stored in the memory is the starting point. In the direction to decelerate and stop, the position closest to each allocation position (specifically, 75% or more (preferably 80% or more)) when allocated at the pitch interval of the probe arrival position in the constant speed region. Imaging data at one probe arrival position at an approximate position) is selected.
Then, by selecting the shooting data at the time of acceleration, the shooting data shot at a constant speed, and the shooting data at the time of deceleration selected in the vertical direction in the shooting order, a rectangular planar image is acquired, thereby enabling shooting. It is possible to avoid the occurrence of distortion in which the image is stretched on the imaging start side of the obtained square image, and it is possible to obtain a normal square image having no step feeling.
Therefore, according to the first invention of the present application, it is suitable for the cylindrical surface inspection method for inspecting the presence or absence of scratches or dents on the surface based on square image data.

  In order to solve the above-mentioned problem, according to the second invention of the present application, a method for capturing a cylindrical surface and acquiring a rectangular planar image is characterized in that the light exit / incident direction of the tip of the probe of the image capturing apparatus is determined within the object to be imaged. The distance between the probe and the inner peripheral surface or the outer peripheral surface of the object to be imaged is kept by keeping the peripheral surface or the outer peripheral surface facing each other and suppressing swinging of the probe and the object to be imaged. When the scanning rotation is relatively applied, the scanning movement is relatively applied to one of the probe and the object to be imaged, and the scanning rotation is a constant speed rotation. The scanning movement per rotation of the probe is made to coincide with the imaging width of the probe in the scanning movement direction, the inspection light is irradiated from the probe to the inner peripheral surface or the outer peripheral surface of the object, and the intensity of the reflected light input to the probe is increased. Digitally convert The imaging for obtaining the raw data is performed once from the origin position in the scanning rotation direction every time when the probe scans and moves by a distance equal to the imaging width in the scanning movement direction per rotation with the scanning movement as a constant speed. And the required shooting area on the inner or outer peripheral surface of the object to be shot, the shooting data is stored in the memory, and the shooting data for each round is arranged in the vertical direction in the shooting order as a line image. A method for obtaining a rectangular planar image, which is a method for obtaining a rectangular planar image by photographing a cylindrical surface, and for photographing an imaging end side portion of the subject area on the inner peripheral surface or outer peripheral surface of the subject. When accompanied by a scanning movement that decelerates from the speed and stops, the imaging data that is shot in the deceleration area of the scanning movement and stored in the memory is shot in the constant speed area and stored in the memory. The position in the data that is closest to each allocation position when allocating at the pitch interval of the probe arrival position in the constant speed area in the direction to decelerate and stop starting from the imaging data at the edge that borders the deceleration area To obtain a rectangular planar image by arranging the photographing data taken at the constant speed and the photographing data taken at the constant speed and the selected photographing data at the deceleration in the vertical direction in the photographing order. Features.

  Compared with the first invention of the present application, the second aspect of the present invention configured as described above performs the scanning movement of the probe of the imaging apparatus without acceleration on the imaging start side but with deceleration on the imaging end side. The difference is that line image data is acquired and a rectangular plane image is acquired. With respect to the deceleration region, the same correction as that of the first invention of the present application can be applied, so that distortion in which the image extends can be removed.

  As a specific example of scanning movement with deceleration without acceleration, for example, the hole of the object to be imaged has a shape in which the upper end of the female screw is open and the lower end is closed, and the female screw is photographed and square image data is to be acquired. Applicable to the case.

  More specifically, the probe of the image capturing apparatus is positioned above the object to be scanned, for example, in a range of 3000 rpm to 30000 rpm and starts to descend accurately, starts to descend, and moves in the middle of descending. Detecting the origin position of the direction and further descending while measuring the actual stroke of the probe, and when it reaches the shooting start position near the entrance in the hole of the object to be scanned, the scanning movement (falling) is continued without stopping. The imaging is started and the line image data obtained per rotation is related to the arrival position of the actual stroke of the probe and stored in the memory. At this time, it is assumed that the center of rotation of the probe and the center of the hole of the object to be photographed exactly coincide with each other. When it is detected by measuring the actual stroke that the imaging position of the tip of the probe has come to the step portion between the female screw and the cylindrical portion, the imaging and memory storage are stopped and the scanning movement is stopped.

  When the scanning movement of the probe, imaging, and storage of the memory are performed as described above, there is no acceleration area on the front side of the constant speed scanning movement, and there is a deceleration area on the back side of the constant speed scanning movement. In the obtained line image data, the elapsed time per rotation at the time of deceleration is longer than the elapsed time per rotation at the constant speed, so that the number of times of imaging in the deceleration region is larger than the number of imaging at the constant speed.

  Therefore, in the second invention of the present application, the shooting data captured in the deceleration area of the scanning movement and stored in the memory is the boundary between the imaging data captured in the constant speed area and stored in the memory. The position closest to each allocation position (specifically 75% or more (specifically, 75% or more)) The imaging data at one probe arrival position at a position approximated at a ratio of preferably 80% or more) is selected, and the imaging data taken at the constant speed and the selected imaging data at the deceleration are arranged in the vertical direction in the order of photography. By arranging to obtain a rectangular planar image arranged side by side, it is possible to avoid the occurrence of distortion that causes the image to expand on the shooting end side of the square image obtained by shooting, and there is no step difference You can obtain the normally square image.

  Furthermore, in order to solve the above-described problem, according to the third aspect of the present invention, a method for photographing a cylindrical surface and obtaining a rectangular planar image is obtained by determining the light incident / incident direction of the tip of a probe of an image photographing device. The distance between the probe and the inner peripheral surface or the outer peripheral surface of the object to be imaged is kept by keeping the peripheral surface or the outer peripheral surface facing each other and suppressing swinging of the probe and the object to be imaged. When the scanning rotation is relatively applied, the scanning movement is relatively applied to one of the probe and the object to be imaged, and the scanning rotation is a constant speed rotation. The scanning movement per rotation of the probe is made to coincide with the imaging width of the probe in the scanning movement direction, the inspection light is irradiated from the probe to the inner peripheral surface or the outer peripheral surface of the object, and the intensity of the reflected light input to the probe is increased. Digitally convert The imaging for obtaining pixel data is performed once from the origin position in the scanning rotation direction every time when the probe scans and moves by a distance equal to the imaging width in the scanning movement direction per rotation with the scanning movement as a constant speed. And the required shooting area on the inner or outer peripheral surface of the object to be shot, the shooting data is stored in the memory, and the shooting data for each round is arranged in the vertical direction in the shooting order as a line image. A method for acquiring a rectangular planar image, a method for acquiring a rectangular planar image by capturing a cylindrical surface, wherein the imaging of the imaging start side portion of the imaging area on the inner peripheral surface or outer peripheral surface of the subject is accelerated. When the scanning movement is performed at a constant speed, the imaging data captured in the acceleration area of the scanning movement and stored in the memory is captured in the constant speed area and stored in the memory. In the data, the position is the closest to each allocation position when the imaging data at the edge that borders the acceleration area is used as the starting point and is allocated in the direction of zero acceleration at the pitch interval of the probe arrival position in the constant speed area. The imaging data at one probe arrival position is selected, and the rectangular plane image is obtained by arranging the selected imaging data at the time of acceleration and the imaging data acquired at the constant speed in the vertical direction in the imaging order. To do.

  Compared with the first invention of the present application, the third invention of the present application is configured such that the scanning movement of the probe of the image photographing apparatus is accelerated on the photographing start side and not decelerated on the photographing end side. The difference is that line image data is acquired and a rectangular planar image is acquired. The acceleration region is configured to perform the same correction as that of the first invention of the present application, so that it is possible to remove the distortion in which the image extends.

  As a specific example of scanning movement that accompanies acceleration and not deceleration, for example, the hole of the object to be imaged has a female screw with an upper end open at the top, and is continuously provided below the female screw and has a larger diameter than the female screw. This is a two-stage hole having a cylindrical portion, and can be applied to a case where only a female screw is photographed to obtain square image data.

  More specifically, the probe of the image photographing apparatus is positioned above the object to be photographed, and, for example, the rotation is accurately rotated at a constant speed in the range of 3000 rpm to 30000 rpm, and the descent starts. When the origin position in the moving direction is detected and the actual stroke of the probe is further lowered from this position, and further reaches the imaging start position near the entrance in the hole of the object to be imaged, unlike the second invention of the present application, the scanning movement ( (The descent) is temporarily stopped, and from here, scanning movement (descent) is started and imaging is started and the line image data obtained per rotation and the arrival position of the actual stroke of the probe are related and stored in the memory, When it is detected by actual stroke measurement that the imaging position of the tip of the probe has come to the lower end of the female screw, the imaging and storage of the memory are stopped, the scanning movement is continued at a constant speed, and stopped in the middle of the cylindrical part. The

  When the scanning movement of the probe, imaging, and storage of the memory are performed as described above, there is an acceleration area in which imaging is performed in front of the constant speed scanning movement, and the line image data obtained by imaging has the number of imaging at the time of acceleration. More than the number of shots at constant speed.

  Therefore, in the third invention of the present application, when the photographing of the photographing start side portion of the photographing area on the inner peripheral surface or the outer peripheral surface of the subject is accelerated and accompanied by the scanning movement at the constant speed, the scanning movement is performed. For the shooting data shot in the acceleration area and stored in the memory, from the shooting data shot in the constant speed area and stored in the memory, the shooting data at the boundary with the acceleration area is set as the starting point in the direction of zero acceleration. 1 that is closest to each allocation position (specifically, a position approximated at a ratio of 75% or more (preferably 80% or more)) when allocated at the pitch interval of the probe arrival position in the constant speed region. By selecting the imaging data at the probe arrival position, and the configuration of acquiring the rectangular plane image by arranging the imaging data at the time of the acceleration and the imaging data captured at the constant speed in the vertical direction in the imaging order, Prevents the distortion of a state where the image is expanded in the shooting start side of the rectangular image obtained by the shadow caused, it can obtain normal rectangular image is not stepped sense.

  According to the first to third aspects of the present invention, capturing a rectangular planar image by capturing the outer peripheral surface, not the inner peripheral surface of the object to be imaged is also included. Specifically, the probe of the image capturing apparatus does not rotate, but opposes the outer peripheral surface of the object to be imaged, and the object to be imaged is chucked by the chuck rotating apparatus so as not to cause a whirling and is rotated at a high speed. It is possible to scan and move in the generatrix direction of the object to be photographed to capture the surface of the cylinder and obtain a square planar image.

  According to the method for acquiring a square planar image by photographing the cylinder surface of the present invention, the scanning movement of the inspection head is performed at a high speed by performing scanning movement with either acceleration on the front side of constant speed movement and deceleration on the rear side. Even if a square image is obtained by shooting, the acceleration area on the shooting start side and the deceleration area on the shooting end side of the rectangular image obtained by shooting are corrected by selecting appropriate line image data and eliminating excess. The normal square image with no sense of level difference can be acquired without causing distortion, and the image data of the acceleration region and the deceleration region can be obtained normally, which can contribute to speeding up the surface inspection. .

  Hereinafter, an embodiment of a method for acquiring a square planar image by photographing a cylinder surface according to the present invention will be described with reference to the drawings.

  FIG. 1 shows a surface inspection apparatus 10 using a method for capturing a square plane image by photographing a cylinder surface according to the present invention. This surface inspection apparatus 10 is substantially the same as FIG. 3 of Patent Document 5, and an object to be imaged (inspected object) W such as a processed metal part supplied from a parts feeder is provided on a base 11. Positioned and chucked by a chuck mechanism 12 having a high-precision automatic centering function, the center of the object to be imaged (inspected object) W and the center of a rotating body (probe) 14 that is rotationally driven by a motor 13 for scanning rotation. Are configured to match with high precision. The rotating body (probe) 14 is precisely rotated at an appropriate constant speed in the range of, for example, 3000 rpm to 30000 rpm by the motor 13 driven by the control signal set and output by the controller 15. As a result, the rotating body (probe) 14 is pivoted with high precision so as not to swing.

  The surface inspection apparatus 10 passes laser light (inspection light) emitted from a light source 27 and focused by a lens (not shown) through the optical path at the center of the moving body 16 and the rotating body (probe) 14, and the lower end of the rotating body 14. The optical path is turned 90 ° by a mirror (optical path changing means) 17 provided in the inspection head 18 and irradiated to the inner peripheral surface of an object to be imaged (inspected object) W such as a metal part substantially perpendicularly, and the reflected light thereof Is received by a number of optical fibers (not shown) arranged in parallel around the optical path of the laser beam in the rotating body 14 and the inspection head 18, further transmitted to the optical fiber 19 on the fixed side, and reflected through the optical fiber 19. The pixel intensity is stored in the memory 20 by converting the light intensity to the controller 15 and digitally converting it.

  The moving body 16 is supported by a boss portion 23 at the tip of an arm 22 extending horizontally from the elevator 21, the elevator 21 is engaged and guided by the elevator guide 24 and screwed to the ball screw shaft 25, and further the ball screw shaft. 25 is rotated and driven by the motor 26, thereby being scanned (lowered). A sensor for detecting the origin of the rotational position of the rotating body 14 and the origin of the lift start reference position of the lift 21 is provided, and these origin signals are input to the controller 15.

  The surface inspection apparatus according to this embodiment is configured to perform the configuration of the method for acquiring a square planar image by photographing the cylinder surface according to the first invention of the present application (assuming that the operation is programmed). ). It should be noted that the image capturing apparatus and the surface inspection apparatus are different in the presence or absence of a determination program for scratches and the like, and reference numeral 10 indicates that the image capturing apparatus and the surface inspection apparatus overlap each other. Details will be described below.

  The light exit / incident direction of the mirror (optical path changing means) 17 provided in the inspection head 18 at the tip of the probe 14 of the image capturing apparatus 10 is kept facing the inner peripheral surface of the object W, and the probe 14 For example, a constant speed scanning rotation of 30000 rpm is given and the swinging is suppressed to keep the facing distance between the probe 14 and the inner peripheral surface of the object W to be precisely constant, and the imaging in the scanning movement direction of the probe 14 is performed. When the width is assumed to be 0.1 mm, the probe 14 is given a scanning movement (downward) of 0.1 mm per time lapse of one rotation of the constant speed scanning rotation.

  After moving the probe 14 to the upper movement limit, it is rotated at a constant speed of 30000 rpm and starts to descend, and the origin position in the scanning movement direction is detected during the lowering, and the actual stroke of the probe 14 is measured from here. As shown in FIG. 2, when the imaging start position near the entrance in the hole h of the object W is reached, the scanning movement (lowering) is temporarily stopped. From this point, the scanning movement (lowering) of the probe 14 is resumed and imaging is started at the same time, and the line image data obtained per rotation and the arrival position of the actual stroke of the probe 14 are related and stored in the memory 20. As shown in FIG. 3, when it is detected by measuring the actual stroke that the imaging position of the tip of the probe 14 has come to the lower end of the hole h of the object W, the imaging and storage of the memory 20 are stopped and the scanning movement is performed. Stop.

When the scanning movement of the probe 14 and the storage of the memory 20 are performed as described above, as shown in FIG. 4, there is an acceleration area b in front of the constant speed scanning movement area a, and the constant speed scanning movement. There is a deceleration area c in which imaging is performed on the rear side of the area a. As shown in Table 1, the line image data obtained by imaging has an elapsed time per rotation at the time of acceleration per rotation at a constant speed. Therefore, the number of times of shooting in the acceleration region is larger than the number of times of shooting at a constant speed.
If the rectangular plane image is acquired by arranging the shooting data at the time of acceleration, the shooting data shot at the constant speed, and the shooting data at the time of deceleration in the vertical direction in this order, as shown in FIG. Distortion occurs in which the image is stretched on the image capturing start side and the image capturing end side. If the square image data is used to inspect a scratch or the like, the quality of the inspection deteriorates. FIG. 5 is an example of a square image diagram formed and displayed by all line image data including extra line image data acquired by the surface inspection apparatus of FIG.

  Therefore, in this embodiment, as shown in Table 1, the shooting data captured in the acceleration area of the scanning movement and stored in the memory 20 is accelerated among the shooting data captured in the constant speed area and stored in the memory 20. 75% or more (preferably 80% or more) with respect to each allocation position when the imaging data at the edge that is the boundary with the region is assigned as the starting point in the direction of zero acceleration at the pitch interval of the probe arrival position in the constant speed region Imaging data at one probe arrival position at a position approximated by a ratio is selected, and excess line image data is removed. In addition, for the shooting data shot in the deceleration area of scanning movement and stored in the memory, the shooting data at the boundary with the deceleration area in the shooting data shot in the constant speed area and stored in the memory is the starting point. One probe arrival at a position approximating 75% or more (preferably 80% or more) to each allocation position when allocating at a pitch interval of the probe arrival position in the constant speed region in the direction of deceleration and stopping. Select the shooting data at the position and remove the extra line image data.

  Then, by adopting a configuration in which the selected shooting data at the time of acceleration, shooting data shot at a constant speed, and selected shooting data at the time of deceleration are arranged in the vertical direction in the shooting order to obtain a rectangular planar image, FIG. As shown in FIG. 5, it is possible to avoid the occurrence of distortion that causes the image to be stretched on the shooting start side of the square image obtained by shooting, and it is possible to obtain a normal square image without a sense of level difference. Therefore, this embodiment is suitable for a cylindrical surface inspection method for inspecting the presence or absence of scratches or dents on the surface based on square image data. FIG. 6 shows a correction that is formed and displayed by line image data obtained by removing the extra line image data in the acceleration region and the extra line image data in the deceleration region from the line image data acquired by the surface inspection apparatus in FIG. It is an example of a rectangular image diagram.

  As described above, according to the method of photographing the cylinder surface of this embodiment and acquiring a rectangular planar image, the scanning movement is performed together with the scanning movement of the probe of the image photographing apparatus, and the scanning movement is accelerated on the photographing start side. Scanning movement with deceleration is performed at the end of imaging at a constant speed, and line image data from the entrance to the depth end in the hole of the object to be imaged (inspected object) W is acquired, and the acceleration area and the deceleration area are As for the line image data, a correction for removing the excess line image data can be performed to obtain a rectangular planar image that can remove the distortion of the image. Further, according to the surface inspection method of this embodiment, Since it is configured to identify defect identification using square plane image data and detect surface scratches on the surface to be inspected, it can accurately acquire data on square plane images, so it is possible to accurately detect surface scratches Ukoto can. As a defect identification method, for example, as disclosed in Japanese Patent Application Laid-Open Nos. 2008-076322 and 2008-076322, data of a rectangular plane image is input to a defect identification unit, and Although it can be configured to detect a surface flaw on the surface to be inspected by identifying the defect based on the density value of the pixel included in the data, other defect identification methods can be applied.

  According to the method for capturing a cylindrical planar image by photographing the cylinder surface of this embodiment, when accompanied by a scanning movement that accelerates to a constant speed and decelerates and stops, the end of the constant speed area The imaging data of one probe arrival position at a position approximating each allocation position when assigned at the pitch interval of the probe arrival position in the constant speed region in the direction of zero acceleration starting from the imaging data of For each of the allocation positions when the data is allocated at the pitch interval of the probe arrival position in the constant speed area, starting from the imaging data at the end of the constant speed area, which is the boundary with the deceleration area, in the direction of deceleration and stopping Select the imaging data at the probe arrival position of the approximate position, select the imaging data at the time of acceleration, the imaging data taken at the constant speed, and the imaging data at the selected deceleration Arranged longitudinally capturing order is configured to obtain a square planar image, it can be acquired normal rectangular image never distortion condition occurs extending.

  According to the method of photographing the cylinder surface of this embodiment and obtaining a rectangular planar image, it can be obtained as rectangular planar image data that is not distorted and photographed in a through-hole (including a screw hole) of the object to be photographed. It can contribute to surface inspection that accurately detects the presence or absence and types of sharp scratches such as dents and depressions, rolling marks, tool marks, and scratches in a planar image.

[Other Embodiments]
The present invention is not limited to the above-described embodiment, but includes variously modified forms within the technical scope without departing from the gist of the invention described in the claims.

  In the above embodiment, the case where acceleration is performed on the front side of the constant-speed scanning movement and the deceleration is accompanied on the rear side is shown. However, the case where acceleration is performed on the front side of the constant-speed scanning movement and deceleration is not performed on the rear side is performed. The present invention includes a case where acceleration is not performed on the front side of movement and deceleration is performed on the rear side. In the above embodiment, the case where the probe is rotated and moved to photograph the inner peripheral surface of the hole of the object to be photographed to obtain a two-dimensional image is shown. However, the object to be imaged is rotated and moved. The present invention also includes a case where a two-dimensional image is acquired by photographing the inner peripheral surface of the hole of the subject. Furthermore, in the above-described embodiment, the present invention also includes a case where a two-dimensional image is acquired by photographing the outer peripheral surface of the subject. Furthermore, the method of photographing the cylinder surface of the present invention and obtaining a rectangular planar image can be mounted on any of the surface inspection apparatuses of Patent Documents 1 to 5, and by the surface inspection apparatus of Patent Documents 1 to 5, The method of acquiring a square planar image by photographing the cylinder surface included in the present invention can be implemented.

It is a schematic front view which shows the surface inspection apparatus using the method which image | photographs the cylinder surface which concerns on embodiment, and acquires a square plane image. It is a schematic front view which shows the state at the time of the imaging | photography start of the surface inspection apparatus of FIG. It is a schematic front view which shows the state at the time of completion | finish of imaging | photography of the surface inspection apparatus of FIG. It is a figure for demonstrating the speed change of the scanning movement of the probe of the surface inspection apparatus of FIG. It is an example of the square image figure before the correction | amendment containing the excess line image data acquired by the surface inspection apparatus of FIG. It is an example of the square image figure which correct | amended the line image data acquired by the surface inspection apparatus of FIG.

Explanation of symbols

10 Surface inspection device (image capture device)
W Subject (inspection object)
14 Rotating body (probe)
17 Mirror (light path changing means)
18 Inspection head 20 Memory

Claims (3)

Keeping the light incident / incident direction of the tip of the probe of the image capturing apparatus facing the inner or outer peripheral surface of the object to be photographed, and suppressing swinging of either the probe or the object to be imaged Accordingly, a scanning rotation capable of maintaining a constant distance between the probe and the inner peripheral surface or the outer peripheral surface of the object to be imaged is relatively applied, and a scanning movement is relatively applied to one of the probe and the object to be imaged. And the scanning movement per rotation when the scanning rotation is a constant speed rotation is made to coincide with the imaging width in the scanning movement direction of the probe,
The scanning movement is performed at a constant speed for imaging in which the inner peripheral surface or outer peripheral surface of the object to be imaged is irradiated from the probe to obtain pixel data by digitally converting the intensity of reflected light input to the probe. For each time that the probe scans and moves by a distance equal to the imaging width in the scanning movement direction per rotation, the inner circumferential surface or the outer circumference of the subject to be scanned for one round from the origin position in the scanning rotation direction. Perform the required shooting area of the surface, store the shooting data in the memory,
A rectangular plane image is obtained by arranging the shooting data for each round as a line image in the vertical direction in the shooting order.
A method for capturing a square plane image by photographing a cylinder surface,
For shooting of the shooting start side portion of the shooting area on the inner peripheral surface or outer peripheral surface of the subject to be photographed, when accompanied by a scanning movement that accelerates to a constant speed and decelerates to stop,
For the shooting data captured in the acceleration area of the scanning movement and stored in the memory, the shooting data at the boundary with the acceleration area in the shooting data captured in the constant speed area and stored in the memory is the starting point. And select imaging data of one probe arrival position that is closest to each allocation position when allocating at a pitch interval of the probe arrival position in the constant speed region in the direction of zero acceleration,
Further, regarding the shooting data shot in the deceleration area of the scanning movement and stored in the memory, the shooting data at the boundary with the deceleration area in the shooting data shot in the constant speed area and stored in the memory Select the imaging data of one probe arrival position that is the closest to each allocation position when allocating at the pitch interval of the probe arrival position in the constant speed region in the direction of decelerating and stopping as the starting point,
The selected shooting data at the time of acceleration, shooting data shot at the constant speed, and the selected shooting data at the time of deceleration are arranged in the shooting direction in the vertical direction to obtain a rectangular planar image,
A method of acquiring a rectangular planar image by photographing a cylindrical surface characterized by the above. Keeping the light incident / incident direction of the tip of the probe of the image capturing apparatus facing the inner or outer peripheral surface of the object to be photographed, and suppressing swinging of either the probe or the object to be imaged Accordingly, a scanning rotation capable of maintaining a constant distance between the probe and the inner peripheral surface or the outer peripheral surface of the object to be imaged is relatively applied, and a scanning movement is relatively applied to one of the probe and the object to be imaged. And the scanning movement per rotation when the scanning rotation is a constant speed rotation is made to coincide with the imaging width in the scanning movement direction of the probe,
The scanning movement is performed at a constant speed for imaging in which the inner peripheral surface or outer peripheral surface of the object to be imaged is irradiated from the probe to obtain pixel data by digitally converting the intensity of reflected light input to the probe. For each time that the probe scans and moves by a distance equal to the imaging width in the scanning movement direction per rotation, the inner circumferential surface or the outer circumference of the subject to be scanned for one round from the origin position in the scanning rotation direction. Perform the required shooting area of the surface, store the shooting data in the memory,
A rectangular plane image is obtained by arranging the shooting data for each round as a line image in the vertical direction in the shooting order.
A method for capturing a square plane image by photographing a cylinder surface,
When photographing with the photographing end side portion of the photographing area on the inner peripheral surface or outer peripheral surface of the subject to be photographed, accompanied by a scanning movement that decelerates from the constant speed and stops.
For the photographic data captured in the deceleration area of the scanning movement and stored in the memory, the photographic data at the boundary with the deceleration area in the photographic data captured in the constant speed area and stored in the memory is the starting point. In the direction of decelerating and stopping, select imaging data of one probe arrival position that is closest to each allocation position when allocated at the pitch interval of the probe arrival position in the constant speed region,
A rectangular planar image is obtained by arranging the shooting data shot at the constant speed and the selected shooting data at the time of deceleration in the shooting direction in the vertical direction.
A method of acquiring a rectangular planar image by photographing a cylindrical surface characterized by the above. Keeping the light incident / incident direction of the tip of the probe of the image capturing apparatus facing the inner or outer peripheral surface of the object to be photographed, and suppressing swinging of either the probe or the object to be imaged Accordingly, a scanning rotation capable of maintaining a constant distance between the probe and the inner peripheral surface or the outer peripheral surface of the object to be imaged is relatively applied, and a scanning movement is relatively applied to one of the probe and the object to be imaged. And the scanning movement per rotation when the scanning rotation is a constant speed rotation is made to coincide with the imaging width in the scanning movement direction of the probe,
The scanning movement is performed at a constant speed for imaging in which the inner peripheral surface or outer peripheral surface of the object to be imaged is irradiated from the probe to obtain pixel data by digitally converting the intensity of reflected light input to the probe. For each time that the probe scans and moves by a distance equal to the imaging width in the scanning movement direction per rotation, the inner circumferential surface or the outer circumference of the subject to be scanned for one round from the origin position in the scanning rotation direction. Perform the required shooting area of the surface, store the shooting data in the memory,
A rectangular plane image is obtained by arranging the shooting data for each round as a line image in the vertical direction in the shooting order.
A method for capturing a square plane image by photographing a cylinder surface,
When shooting with respect to the shooting start side portion of the shooting area on the inner peripheral surface or outer peripheral surface of the subject to be photographed, accompanied by a scanning movement that accelerates to the constant speed,
For the shooting data captured in the acceleration area of the scanning movement and stored in the memory, the shooting data at the boundary with the acceleration area in the shooting data captured in the constant speed area and stored in the memory is the starting point. And select imaging data of one probe arrival position that is closest to each allocation position when allocating at a pitch interval of the probe arrival position in the constant speed region in the direction of zero acceleration,
A rectangular planar image is obtained by arranging the shooting data at the selected acceleration and the shooting data shot at the constant speed in the vertical direction in the shooting order.
A method of acquiring a rectangular planar image by photographing a cylindrical surface characterized by the above.

Images