JP4837538B2 - End position measuring method and dimension measuring method - Google Patents

Description

  The present invention relates to a method for measuring the position of an end portion of a photoconductor drum substrate of a copying machine as an object to be measured, and a method for measuring a dimension of a body to be measured based on the method.

  It is conceivable to measure the shape, dimensions, etc. of various measured objects based on images obtained by photographing the measured object with a camera.

  When a three-dimensional object is photographed with a lens, distortion occurs in which the periphery is larger or bent than the center of the image. In order to cope with such distortion, for example, Patent Document 1 below proposes a method of removing distortion by changing the magnification between the center and the periphery of an image. In Patent Document 2 below, a method is proposed in which a laser is projected onto a measurement object parallel to the camera axis, and the positional relationship between captured images is measured using the laser information as a reference.

In Patent Document 3 below, image collation is performed by comparing a camera image of a target object in a real space and an image verification data data that is a database of a plurality of model images obtained by imaging various three-dimensional postures of the target object. A method for correcting a three-dimensional posture in model image matching for estimating a three-dimensional posture of a target object in real space is disclosed. In this document, it is proposed to rotationally correct a provisionally estimated three-dimensional posture based on a line-of-sight difference between the center of gravity of a camera image and a model image.
JP-A-11-161779 JP 2006-23262 A JP 2004-362128 A

  However, conventionally, the position of the end of the object to be measured and the distance (dimensions) between the ends are accurate based on the image captured by the camera, without using a relatively expensive three-dimensional measurement apparatus that uses trigonometry. No method has been proposed for measuring.

  In other words, if the object to be measured does not have a height in the camera axis direction, the position of the edge can be obtained simply by correcting the distortion of the lens and the like by detecting the position of the contour line of the object to be measured in the captured image. be able to.

  However, in the case of a camera having a normal angle of view, the shooting angle differs depending on the position in the shot image. Therefore, in the case of a measured object having a height in the camera axis direction, depending on the relationship between the shooting angle and the shape of the end, There is a possibility that parts having different height positions constituting the image are photographed.

  For this reason, when the position to be measured for each object to be measured is not constant, or when the size or shape is different, the photographing angle condition differs for each photographing opportunity, and depending on the condition, the error becomes large and accurate position measurement cannot be performed. The problem arises.

  The present invention has been made in view of the above problems, and even if the object to be measured has a height in the camera axis direction, the position of the end portion is accurately measured, and the dimensions of the object to be measured are determined. It aims at providing the method etc. which can be measured correctly.

In order to solve the above problems, the present invention provides the following means. That is,
[1] A subject having a height in the camera axial direction of the camera is photographed by a camera having an angle of view,
Detect the outermost contour of the measured object from the captured image,
In accordance with the position of the detected outermost contour line in the captured image, the height position of the end of the measurement object being photographed as the outermost contour line is determined,
Wherein the position of the most outer profile in the photographed image, the by correcting depending on the height of the most outer profile line, the camera of the end of the object to be measured has been taken as the most outer profile A method for measuring an end position, comprising calculating a position in a direction crossing an axial direction.

  [2] The end position measurement method according to item 1 above, wherein the correction is performed using a different correction calculation formula according to the height position of the end of the measurement object photographed as the outermost contour line.

  [3] End position according to item 1 or 2, wherein height information is set in advance for a finite number of candidate parts that can be imaged as the outermost contour line in accordance with the shape of the end of the measurement object. Measuring method.

[4] For the candidate site, an area in the captured image when being captured as the outermost contour is set in advance,
The preceding item 3 which determines which candidate part is imaged as the outermost contour line according to which region in the captured image the outermost contour line detected from the captured image belongs, and determines its height position. The end position measuring method as described in 2.

  [5] The method for measuring an end position according to item 3 or 4 above, wherein the candidate site includes an upper side edge and a lower side edge of a surface constituting the end part.

  [6] The end position measuring method according to any one of the preceding items 1 to 5, wherein the object to be measured is irradiated with backlight illumination to perform imaging.

  [7] The edge position measuring method according to any one of items 1 to 6 above, in which photographing is performed with a one-dimensional camera.

  [8] The edge position measuring method according to any one of items 1 to 6 above, in which shooting is performed with a two-dimensional camera.

  [9] Calculate the position in the direction intersecting the camera axis of the end of the measured object by the end position measuring method according to any one of 1 to 8 above, and based on the calculated position of the end A dimension measuring method characterized by calculating a dimension of an object to be measured.

  [10] The dimension measuring method according to item 9, wherein the positions of the measurement object are photographed to calculate each position, and the dimensions of the measurement object are calculated based on the calculated positional relationship of the plurality of edges. .

  [11] The dimension measuring method according to item 10, wherein a plurality of ends of the measured object are photographed with different cameras and each position is calculated.

  [12] The dimension measuring method according to [10], wherein the plurality of ends of the measurement object are sequentially photographed by moving the camera to calculate each position.

  [13] The dimension measuring method according to the above item 10, wherein the position to be calculated is calculated by moving the object to be measured and sequentially photographing a plurality of ends with a camera.

  [14] In a state where a predetermined part of the measurement object is brought into contact with a predetermined position reference part, the measurement object is photographed to calculate the position of the end part, and the position of the position reference part is calculated. 10. The dimension measuring method according to item 9, wherein the dimension of the measured object is calculated based on the position of the part.

  [15] The dimension measuring method according to any one of items 9 to 14, wherein the object to be measured is a cylindrical body.

  [16] The dimension measuring method according to any one of items 9 to 14, wherein the member to be measured is a photosensitive drum substrate.

[17] An imaging means for imaging a measurement object having a height in the camera axial direction of the camera with a camera having an angle of view;
Contour detection means for detecting the outermost contour of the measured object from the captured image;
A height position discriminating means for discriminating the height position of the end of the measured object imaged as the outermost contour line according to the position of the detected outermost contour line in the captured image; By correcting the position of the outermost contour line in accordance with the height position of the outermost contour line, it intersects the camera axis direction of the end of the measured object being photographed as the outermost contour line An end position calculating means for calculating a position in a direction to perform;
An end position measuring device comprising:

[18] The end position measuring device according to item 17,
Dimension calculating means for calculating the dimension of the measured object based on the calculated position of the end;
A dimension measuring device comprising:

  According to the above invention [1], the height position of the end of the measured object photographed as the outermost contour line is determined according to the position in the photographed image, and is corrected according to the height position. Even when the measurement object has a height in the camera axis direction and there is a possibility that a part having a different height position constituting the end portion may be imaged depending on the imaging angle, the position of the end portion is accurately measured. be able to. In addition, since the outermost contour line is used as an end position detection target, it can be detected with high reliability.

  According to the above invention [2], an appropriate correction calculation can be performed according to the height position of the end.

  According to the invention [3], since the height information of the candidate part is set in advance, it is possible to accurately determine the height position of the end portion of the measured object photographed as the detected outermost contour line.

  According to the above invention [4], a region to be imaged as the outermost contour line is set in advance, and the candidate region being imaged is determined according to which region it belongs to. Thus, the height position of the end portion of the measured object can be quickly determined.

  According to the above invention [5], the height position is accurately determined in correspondence with the case where either the upper edge or the lower edge of the surface constituting the end portion is photographed as the outermost contour line depending on the photographing angle. Can be determined.

  According to the invention [6], the outermost contour line can be detected more accurately.

  According to the above invention [7], the position of the outermost contour line can be determined with high accuracy with high resolution.

  According to the above invention [8], the position of the end of the measured object can be measured in the two-dimensional direction in the captured image.

  According to the said invention [9], the dimension of a to-be-measured body can be measured correctly based on the position of the edge part of a to-be-measured body.

  According to the invention [10], since the dimensions of the measured object are calculated based on the positional relationship calculated by photographing a plurality of end portions, the dimensions are measured regardless of the position of the measured object at the time of photographing. be able to.

  According to the above invention [11], each camera can be fixed at a position where each end of the measured object is included in the imaging range, so that the camera position can be stabilized and accurate measurement can be performed.

  According to the said invention [12], the dimension of a to-be-measured body can be obtained from the position measurement result of the some edge part by one camera.

  According to the said invention [13], the dimension of a to-be-measured body can be obtained from the position measurement result of the some edge part by one camera.

  According to the above invention [14], the dimension of the measured object can be obtained from the position measurement result of the end by one camera. In addition, since the camera can be fixed at a position where the end of the object to be measured is included in the imaging range, the camera position can be stabilized and accurate measurement can be performed.

  According to the above invention [15], it is possible to accurately measure the length of the cylindrical body and contribute to the supply of the cylindrical body with the required dimensional accuracy, for example.

  According to the above invention [16], it is possible to accurately measure the length of the photosensitive drum substrate and contribute to the supply of the photosensitive drum substrate with the required dimensional accuracy, for example.

  According to the above invention [17], the height position of the end of the measured object photographed as the outermost contour line is determined according to the position in the photographed image, and is corrected according to the height position. Even when the measurement object has a height in the camera axis direction and there is a possibility that a part having a different height position constituting the end portion may be imaged depending on the imaging angle, the position of the end portion is accurately measured. be able to. In addition, since the outermost contour line is used as an end position detection target, it can be detected with high reliability.

  According to the above invention [18], the dimension of the measurement object can be accurately measured based on the position of the end of the measurement object.

  Hereinafter, the present invention will be described based on embodiments.

  FIG. 1 is an explanatory view of a dimension measuring apparatus that performs a dimension measuring method of a measurement object according to the present invention.

  Here, a case where a cylindrical body used as a substrate for a photosensitive drum is a measurement object 90 and its length is measured is taken as an example. Both end surfaces of the cylindrical body as the measurement target 90 are flat and perpendicular to the length direction of the measurement target 90. Such a three-dimensional object to be measured 90 has a height in any shooting direction.

  The dimension measuring apparatus includes cameras 10 and 10 that respectively capture both end portions 91 and 91 of the measured object 90, and an image processing apparatus 20 that calculates the dimensions of the measured object 90 based on images captured by the cameras 10 and 10. Illuminating devices 30 and 30 for irradiating backlight illumination from behind the object to be measured 90 when viewed from the camera 10 and 10 side are provided.

  The cameras 10 and 10 have an angle of view θ. For this reason, the photographing angle with respect to each part of the subject (measured object) 90 can be changed depending on the position of the photographed image. In this embodiment, a two-dimensional camera that captures a two-dimensional image is employed as the cameras 10 and 10.

  The cameras 10 and 10 capture a captured image that can detect the outermost contour lines of the end portions 91 and 91 of the measurement object 90. Here, in the present invention, the outermost contour line means that the outermost contour line as viewed from the camera 10 is formed by each part constituting the measured object 90.

  In this embodiment, the cameras 10 and 10 are provided with a plurality of units (two units) at positions aiming at both end portions 91 and 91 of the measured object 90, respectively, while the length dimension measurement is performed on the measured objects 90. The position is designed to be fixed.

  The cameras 10 and 10 aim at both end portions 91 and 91 of the measured object 90 from directly above when the measured object 90 according to the ideal design dimensions is placed at an ideal position. Placed in position. Specifically, it is a position where each camera axis 11, 11 is located on a plane including each end face of the measurement object 90. Here, in the present invention, the camera axis 11 refers to a straight line connecting the center of the camera 10 and the center of the captured image.

  Thus, in the case of the ideal measured object 90, the position setting of the cameras 10 and 10 that the end surfaces of the measured objects coincide with the camera axes 11 and 11 of both the cameras 10 and 10 is, for example, an ideal master work. Can be realized by adjusting the camera position so that both ends thereof are on the camera axes 11 and 11.

  Further, since the cameras 10 and 10 are arranged at positions where the both end portions 91 and 91 of the measured object 90 are aimed from directly above, the position and length dimension of the end portion 91 of the measured object 90 to be measured are determined. The direction is orthogonal to the camera axes 11 and 11.

  The cameras 10 and 10 function as photographing means for photographing the measured object 90 having a height in the camera axial direction.

  The illuminating devices 30 and 30 are configured using an arbitrary light source such as a fluorescent lamp or an LED, and in the captured images of the cameras 10 and 10, the outermost contour lines of the end portions 91 and 91 of the measured object 90 are used as silhouette images. It is something that can clearly emerge. By using such backlight illumination, the outermost contour line of the measurement object 90 can be detected more accurately.

  The image processing apparatus 20 includes, for example, a computer having a CPU, a memory, an external storage device, an input unit such as a keyboard and a mouse, an output unit such as a monitor, and an input / output interface with other devices. As will be described later, the image processing apparatus 20 functionally includes an outline detection unit, a height position determination unit, an end position calculation unit, and a dimension calculation unit.

  The image processing apparatus 20 calculates these positions based on the captured images of the both ends 91 and 91 of the measurement object 90, and further calculates both ends 91 and 91 based on the calculated positions of both ends 91 and 91. The distance between them is calculated as the length dimension of the measurement object 90 and output.

  The normal cameras 10 and 10 having an angle of view as used in the present invention have different shooting angles with respect to the subject depending on the position in the shot image. For this reason, in the case of the measurement object 90 having a height in the camera axis direction, the parts having different height positions constituting the end portions 91 and 91 are photographed depending on the relationship between the photographing angle and the shape of the end portions 91 and 91. There is a possibility.

  For example, as in the example of the present embodiment, when the end portions 91 and 91 of the measured object 90 have end faces parallel to the camera axis 11, there are shooting angles at which the end faces can be seen and shooting angles at which the end faces cannot be seen. When the end surface is visible, the lower edge (the side far from the camera 10) of the end surface is photographed as the outermost contour line of the end portion. On the other hand, when the end face cannot be seen, the outermost contour line being photographed is photographed with the upper edge (side closer to the camera 10) of the end face as the outermost contour line of the end portion. However, the height position in the camera axis direction differs between the upper edge and the lower edge of the end face. For this reason, even if the upper edge and the lower edge are detected at the same distance from the center of the screen in the shooting screen, the position of the edge in each case (distance from the camera axis) in the real space Are not identical.

  In the image processing apparatus 20 according to the present embodiment, it is determined whether or not such a portion having a different height position that constitutes the end of the measurement object 90 is detected, and is detected in the captured image according to each case. The position of the outermost contour line thus corrected is corrected, and the measurement of the end position of the measured object and the measurement of the length dimension obtained by bundling the position measurement results of both end portions 91 and 91 of the measured object 90 are accurately performed. Is what you do.

  Hereinafter, the calculation processing of the position of the end portion 91 performed in the image processing apparatus 20 will be described based on an example in which the left end portion of the measurement object 90 is a measurement target.

  FIG. 2A is an explanatory diagram illustrating a case where the end 91 of the measurement target 90 is photographed in a positional relationship where the camera shaft 11 is positioned on a plane including the end surface 92 of the measurement target 90. FIG. b) is an example of the captured image 12 in that case.

  The positional relationship in which the camera shaft 11 is positioned on a plane including the end surface 92 of the measured object 90 is a state in which the camera 10 is positioned directly above the end surface 92 as shown in FIG.

  At this time, as shown in FIG. 4B, the end surface 92 of the measured object 90 is in a straight line shape on the photographed image 12 so that all the portions including the upper edge and the lower edge at different height positions are aligned. Thus, it is shown as the outermost contour that forms the silhouette of the measurement object 90. That is, the outermost contour line is located at the exact center in the captured image 12.

  FIG. 3A is an explanatory diagram illustrating a case where the end 91 of the measurement target 90 is photographed in a positional relationship in which the camera shaft 11 is positioned outside a plane including the end surface 92 of the measurement target 90. FIG. (B) is an example of a photographed image in that case.

  The positional relationship in which the camera shaft 11 is positioned outside the plane including the end surface 92 of the measured object 90 is the longitudinal direction of the measured object 90 from directly above the end surface 92 as shown in FIG. It is in a state where it is located on the outside of the direction (further left outside the left end) and at a shooting angle at which the end face 92 can be seen.

  At this time, as shown in FIG. 5B, the end surface 92 of the measured object 90 appears in the captured image 12 as an ellipse having a certain area, and the lower edge 93 of the end surface 92 is the silhouette of the measured object 90. Is shown on the right half side of the photographed image 12 as the outermost contour line. That is, the outermost contour line is located in the right half surface area in the captured image 12.

  Here, in the captured image 12, the conversion of the positional relationship between the position in the image 12 and the real space is based on the center height of the measured object 90 (hereinafter, this height is referred to as a reference height). Then, it can be said that the position of the end surface 92 in the length direction of the measurement object 90 (left and right direction in FIG. 3) should be detected as the line 95 in FIG.

  4A is an explanatory diagram illustrating a case where the end 91 of the measurement target 90 is photographed in a positional relationship in which the camera shaft 11 is positioned inside a plane including the end surface 92 of the measurement target 90. FIG. (B) is an example of a photographed image in that case.

  The positional relationship in which the camera shaft 11 is positioned on the inner side of the plane including the end surface 92 of the device under test 90 is the longitudinal direction of the device under test 90 from directly above the end surface 92 as shown in FIG. This is a state where the photographing angle is located inside the direction and the end face 92 is not visible.

  At this time, as shown in FIG. 4B, the end surface 92 of the measurement object 90 is not shown in the photographed image 12, and the upper edge 94 of the end surface 92 is the outermost contour line that forms the silhouette of the measurement object 90. This is shown on the left half side of the photographed image 12. That is, the outermost contour line is located in the left half surface area in the captured image 12.

  Here, in the captured image 12, assuming that the conversion of the positional relationship between the position in the image 12 and the real space is based on the center height (reference height) of the measured object 90, the length of the measured object 90. It can be said that the position of the end surface 92 with respect to the vertical direction (the left-right direction in FIG. 4) should be detected as the line 95 in FIG.

  In this way, depending on the positional relationship between the position of the end 91 of the measured object 90 and the camera axis 11, the measured object 90 detected as the outermost contour line in the right half and the left half of the captured image 12 is shown. The site | parts of the edge part 91 differ, and the height position of these each site | part differs.

  Therefore, in this embodiment, the height position of the part detected as the outermost contour line is determined based on the region in the captured image where the outermost contour line is detected, and correction according to the height position is performed. The exact position of the end is calculated by.

  Next, an example of a specific formula for calculating the end position will be described.

  FIG. 5 illustrates a method for calculating the end position when the end 91 of the measured object 90 is photographed in a positional relationship where the camera shaft 11 is positioned outside the plane including the end surface 92 of the measured object 90. It is explanatory drawing. In the figure, the captured image 12 of the camera 10 is represented below the measured object 90.

  In this example, the measured object 90 is in a position in which the end surface 92 of the measured object 90 is away from the measured object 90 by a distance L from the camera axis 11. In this positional relationship, as described above, the lower edge 93 of the end surface 92 is imaged as the outermost contour line of the end portion 91 in the captured image 12.

  However, as described above, if the conversion of the positional relationship between the position in the captured image 12 and the real space is based on the center height of the measurement object 90 as the reference height, the image is originally captured as the end portion 91. The region to be power is a point P on the center height of the end face 92.

  That is, as shown in FIG. 5, the lower edge 93 is detected as the outermost contour line at a distance X from the camera axis 11 on the photographed image 12, but originally to the photographed image 12 at the point P. It can be said that the position of the distance Xans should have been detected from the camera axis 11 which is the projection point.

  Therefore, if the position X of the outermost contour line in the photographed image 12 is corrected to be converted into the original position Xans, the accurate position of the end 91 can be obtained. Therefore, the ratio of the position Xans that should have been detected from the position X of the detected outermost contour line is examined.

  The vertex of the angle of view of the camera 10 is O, the point on the end surface 92 at the center height (reference height) 95 of the measured object 90 is P, and the camera axis 11 is also at the center height (reference height) 95. , A is the lower edge 93 of the end face detected as the outermost contour line, C is the intersection of the horizontal straight line 96 and the straight line OP at the height of the lower edge 93, and A point on the camera axis 11 is B, and a height dimension of the measurement object 90 is D.

Since the straight line 96 and the surface of the captured image 12 are parallel,
BC: BQ = X: Xans
Since the distance between the camera shaft 11 and the end face 92 is the same regardless of the height position,
AP = BC
Here, triangle OAP and triangle OBQ are similar,
OA: OB = AP: BQ
H: (H + D / 2) = X: Xans
Therefore,
Xans = (1 + D / 2H) · X (1)
It becomes.

  When the outermost contour line is seen in the region on the right side of the photographed image 12, the lower edge 93 of the end face 92 is detected as the outermost contour line. Therefore, the position X of the outermost contour line in the photographed image 12 is detected. Is converted and corrected to Xans by the calculation formula (1), and this Xans is converted into a distance from the camera axis 11 on the reference height 95, whereby the distance L indicating the position of the end in the real space can be calculated. .

  FIG. 6 illustrates a method for calculating the end position when the end 91 of the measurement target 90 is photographed in a positional relationship in which the camera shaft 11 is positioned inside a plane including the end surface 92 of the measurement target 90. It is explanatory drawing. In the figure, the captured image 12 of the camera 10 is represented below the measured object 90.

  In this example, the measured object 90 is in a position in which the end surface 92 of the measured object 90 is separated from the camera axis 11 by a distance L to the inside of the measured object 90. In this positional relationship, as described above, the upper edge 94 of the end surface 92 is photographed as the outermost contour line of the end portion 91 in the photographed image 12.

  However, as described above, if the conversion of the positional relationship between the position in the captured image 12 and the real space is based on the center height of the measurement object 90 as the reference height, the image is originally captured as the end portion 91. The region to be power is a point P on the center height of the end face 92.

  That is, as shown in FIG. 6, the upper edge 94 is detected as the outermost contour line at a distance X from the camera axis 11 on the photographed image 12, but originally the point P onto the photographed image 12 is detected. It can be said that the position of the distance Xans should be detected from the camera axis 11 which is the projection point.

  Therefore, if the position X of the outermost contour line in the photographed image 12 is corrected to be converted into the original position Xans, the accurate position of the end 91 can be obtained. Therefore, the ratio of the position Xans that should have been detected from the position X of the detected outermost contour line is examined.

  The vertex of the angle of view of the camera 10 is O, the point on the end surface 92 at the center height (reference height) 95 of the measured object 90 is P, and the camera axis 11 is also at the center height (reference height) 95. Is the point A, C is the upper edge 94 of the end face detected as the outermost contour line, Q is the intersection of the horizontal straight line 97 and the straight line OP at the height position of the upper edge 94, and the camera axis on the straight line 97 A point on 11 is B, and a height dimension of the measurement object 90 is D.

Since the straight line 97 and the surface of the captured image 12 are parallel,
BC: BQ = X: Xans
Since the distance between the camera shaft 11 and the end face 92 is the same regardless of the height position,
AP = BC
Here, triangle OAP and triangle OBQ are similar,
OA: OB = AP: BQ
H: (HD / 2) = X: Xans
Therefore,
Xans = (1-D / 2H) · X (2)
It becomes.

  When the outermost contour line appears in the left region of the photographed image 12, the upper edge 94 of the end face 92 is detected as the outermost contour line. Therefore, the position X of the outermost contour line in the photographed image 12 is determined. The distance L indicating the position of the end portion in the real space can be calculated by converting and correcting to Xans by the calculation formula (2) and converting this Xans into the distance from the camera axis 11 on the reference height 95.

  Next, the function of the image processing apparatus 20 that calculates the end position by the above calculation method and further calculates the length dimension of the measurement object 90 will be described.

FIG. 7 is a functional block diagram of the image processing apparatus 20. As shown in the figure, the image processing apparatus 20, the contour detection unit 21, the height position determining means 22, the edge position calculating means 23, and a dimension calculation hand stage 2 4 functional.

  The contour line detecting means 21 detects the outermost contour lines of the end portions 91 and 91 of the measured object 90 from the captured images 12 of the end portions 91 and 91 of the measured object 90 by the cameras 10 and 10. I do. As described above, since the measured object 90 is illuminated by the backlight from behind, the measured object 90 appears as a silhouette in the captured image 12, and the outermost contour line can be detected from the brightness difference. .

  The height position discriminating means 22 discriminates the height position of the end portion of the measured object 90 photographed as the outermost contour line according to the position of the detected outermost contour line in the captured image 12. Is.

  As described above, when the end surface 92 parallel to the camera axis 11 is to be measured, whether or not the end surface 92 is visible depending on the positional relationship between the end surface 92 and the camera axis 11 and, as a result, the upper edge 94 as the outermost contour line. And which of the lower edges 93 is visible is different.

  Therefore, in this embodiment, the upper edge 94 and the lower edge 93 are set in advance as candidate parts that are parts that can be detected as the outermost contour line, and their reference height (the center of the object 90 to be measured) is set. Height information from (height) is set in advance.

  Further, regarding the upper edge 94 and the lower edge 93 which are candidate parts, the areas on the right half surface and the left half surface centered on the camera axis 11 as the areas in the captured image 12 when being photographed as the outermost contour line. Is set in advance.

  As a result, if the outermost contour line is detected from the photographed image 12, the upper edge 94 and the bottom edge are detected from whether the photographed image 12 is in the right half surface area or the left half surface area obtained by dividing the photographed image 12 into two. It is possible to easily and quickly determine which side edge 93 is visible, and obtain height information thereof.

The end position calculation unit 23 corrects the position of the outermost contour line in the captured image 12 according to the height position of the outermost contour line, thereby measuring the object 90 to be measured as the outermost contour line. The position of the end portion 91 in the direction intersecting the camera axis 11 direction is calculated.

  In this embodiment, as described above, since it is determined whether the portion detected as the outermost contour line is the upper edge 94 or the lower edge 93 of the end surface 92, the above correction formula ( According to 1) or (2), the position of the outermost contour line in the captured image 12 is corrected.

In this embodiment, for taking respective opposite ends 91, 91 of the object to be measured 90 by two cameras 10, 10, contour detection on than, the height position determination, and ends the position calculation The processing is performed for both end portions 91 and 91, respectively.

  The dimension calculating means 24 calculates the dimension of the measured object 90 based on the calculated position of the end.

  In this embodiment, the dimension of the measured object 90 is calculated based on the positions of both end portions 91 and 91 of the measured object 90 measured from the captured images 12 of the two cameras 10 and 10 described above.

  Specifically, since these two cameras 10 and 10 are both ideal measurement objects 90, they are arranged at positions where the end portions 91 and 91 are captured at the center of the captured image 12. It is possible to calculate the length dimension of the measured object 90 to be measured by adding or subtracting the deviation amount from the ideal position of 91, 91 to the ideal length dimension of the measured object 90. it can.

  As described above, according to the dimension measuring apparatus according to the present embodiment, the height position of the end of the measurement object that is imaged as the outermost contour line is determined according to the position in the captured image, and the height position is determined. Even if there is a possibility that the part to be measured has a height in the camera axis direction and a part having a different height position constituting the end depending on the imaging angle may be imaged, Can be measured accurately.

  In addition, since the outermost contour line is used as an end position detection target, it can be detected with high reliability.

  In particular, the dimension measuring apparatus according to the present embodiment can measure the position of the end of the measured object with high accuracy from an image taken by a camera having a general angle of view, and is an expensive three-dimensional shape measurement. Functions equivalent to those of the apparatus can be realized at a lower cost.

  In addition, since a different correction calculation formula is used depending on the height position of the end, an appropriate correction calculation can be performed.

  Further, since the height information of the candidate part is set in advance, the height position of the end of the measured object that is imaged as the detected outermost contour line can be accurately determined.

  In addition, a region to be imaged as the outermost contour line is set in advance, and a measured object imaged as the detected outermost contour line is determined in order to determine a candidate region being imaged according to which region belongs to It is possible to quickly determine the height position of the end portion.

  Moreover, since the measurement is performed by irradiating the measurement object 90 with backlight illumination, the outermost contour line can be detected more accurately.

  In addition, since the length dimension of the measurement object 90 is calculated based on the positional relationship calculated by imaging both end portions 91 and 91 of the measurement object 90, the measurement object 90 is not dependent on the position of the measurement object 90 at the time of imaging. The dimension can be measured.

  In addition, since each end 91, 91 of the object to be measured is photographed by different cameras 10, 10 and the respective positions are calculated, each camera 10.10 uses each end 91, 91 of the object 90 to be imaged. The position of the camera can be fixed, and the camera position can be stabilized and accurate measurement can be performed.

  In addition, the length of the cylindrical body (photosensitive drum substrate) serving as the measurement target 90 can be accurately measured, which can contribute to the supply of a cylindrical body with the required dimensional accuracy, for example.

  Next, a second embodiment of the present invention will be described.

  FIG. 8 is an explanatory diagram of the dimension measuring apparatus according to the second embodiment.

As shown in the figure, in the dimension measuring apparatus according to the second embodiment, one end (right side) of the measurement object 90 is brought into contact with a predetermined position reference portion 40 that is predetermined in advance. In this state, similarly to the above-described embodiment, the other (left side) end portion is photographed by the camera 10 having the angle of view θ, and the position thereof is measured. Then, based on the position of the end and the calculated position of the position reference portion, and calculates the size of the object to be measured.

  According to such a dimension measuring apparatus, the dimension of the measurement object 90 can be obtained from the position measurement result of the end by one camera 10. In addition, since the camera 10 can be fixed at a position where one end 91 of the measurement object 90 is included in the imaging range, the camera position can be stabilized and accurate measurement can be performed.

  As mentioned above, although this invention was demonstrated based on embodiment, this invention is not limited above, You may comprise as follows.

  (1) In the above embodiment, candidate parts that can be imaged as the outermost contour line are set in advance. However, the candidate part is not set, and the height position is determined from the position in the captured image of the outermost contour line. It may be calculated from a calculation formula or the like. For example, when the end surface of the object to be measured is composed of a curved surface and there are portions that can be imaged as the outermost contour line continuously in the height direction, the position and end of the outermost contour line in the captured image A part being photographed may be specified from the shape information of the part, and the height position may be determined.

  (2) In the above embodiment, only two of the upper edge and the lower edge of the end face of the measurement object are set in advance as candidate parts that can be photographed as the outermost contour line, but there are three or more candidate parts. Also good. For example, when the end surface of the measured object is composed of a combination of a plurality of planes and has a plurality of edge portions, each edge portion can be set as a candidate site.

  (3) In the above embodiment, the horizontal position of the outermost contour line, that is, the horizontal position orthogonal to the camera axis placed in the vertical direction is calculated. However, the position of the outermost contour line to be calculated is horizontal. It does not have to be a position in the direction. Further, the position may not be the position in the direction orthogonal to the camera axis as long as the position is in the direction intersecting the camera axis.

  (4) In the above-described embodiment, imaging is performed by irradiating backlight illumination from behind the object to be measured. However, imaging that can detect the outermost contour line at the end of the object to be measured without using backlight illumination or the like. May be performed.

  (5) In the above embodiment, the measurement device is configured as a dimension measurement device that calculates the length dimension after measuring the positions of both ends of the object to be measured. However, the present invention does not calculate the length dimension and does not calculate the length dimension. You may apply to the edge position measuring apparatus which only measures the position of the 1 or several edge part of a body.

  (6) In the above-described embodiment, the cylindrical photosensitive drum substrate is used as the measurement target. However, the measurement target is not limited to this, and the measurement target having an arbitrary height is the target. be able to.

  (7) In the above embodiment, a two-dimensional camera is used as the camera. However, by adopting a one-dimensional camera that can be expected to have a higher resolution, the position of the outermost contour line can be obtained with higher accuracy. Also good.

  (8) In the above embodiment, the end position and length are measured only in the one-dimensional direction called the length direction of the measurement object 90. However, if a two-dimensional camera is used as the camera, For each of the two-dimensional directions, the position of the end of the measured object may be measured.

  (9) In the above embodiment, each position is measured by photographing both ends of the measured object with different cameras, but each end is photographed sequentially by moving one camera, and each position is calculated. By doing so, you may make it perform the dimension measurement of a to-be-measured body. Alternatively, the position of the object to be measured may be calculated by moving the object to be measured with respect to one camera and sequentially photographing each end. If it does in this way, the dimension of a to-be-measured object can be obtained from the position measurement result of a plurality of ends by one camera.

It is explanatory drawing of the dimension measuring apparatus which performs the dimension measuring method of the to-be-measured object concerning this invention. (A) is explanatory drawing which shows the case where the edge part of a to-be-measured object was image | photographed by the positional relationship to which a camera axis is located on the plane containing the end surface of a to-be-measured object, (b) is the imaging | photography image in that case It is an example. (A) is explanatory drawing which shows the case where the edge part of a to-be-measured object was image | photographed with the positional relationship to which a camera axis is located outside the plane containing the end surface of a to-be-measured object, (b) is a picked-up image in that case It is an example. (A) is explanatory drawing which shows the case where the edge part of a to-be-measured object was image | photographed with the positional relationship to which a camera axis is located inside the plane containing the end surface of a to-be-measured body, (b) is a picked-up image in that case It is an example. It is explanatory drawing explaining the calculation method of an edge part position when the edge part of a to-be-measured object is image | photographed by the positional relationship in which a camera axis is located outside the plane containing the end surface of a to-be-measured object. It is explanatory drawing explaining the calculation method of an edge part position when the edge part of a to-be-measured object is image | photographed by the positional relationship to which a camera axis is located inside the plane containing the end surface of a to-be-measured object. It is a functional block diagram of an image processing apparatus. It is explanatory drawing of the dimension measuring apparatus concerning 2nd Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Camera 11 Camera shaft 12 Captured image 20 Image processing apparatus 30 Illumination apparatus 90 Measurement object 91 End part 92 End surface 93 Upper edge 94 Lower edge

Claims (18)

Using a camera having an angle of view, photograph the object to be measured having a height in the camera axis direction of the camera,
Detect the outermost contour of the measured object from the captured image,
In accordance with the position of the detected outermost contour line in the captured image, the height position of the end of the measurement object being photographed as the outermost contour line is determined,
Wherein the position of the most outer profile in the photographed image, the by correcting depending on the height of the most outer profile line, the camera of the end of the object to be measured has been taken as the most outer profile A method for measuring an end position, comprising calculating a position in a direction crossing an axial direction.  The end position measuring method according to claim 1, wherein the correction is performed using a different correction calculation formula according to a height position of the end of the measured object photographed as the outermost contour line.  The end position measuring method according to claim 1 or 2, wherein height information is set in advance for a finite number of candidate parts that can be imaged as the outermost contour line in accordance with the shape of the end of the measurement object. . For the candidate part, a region in the photographed image when photographing as the outermost contour line is set in advance,
The candidate position is determined as an outermost contour line according to which region in the captured image the outermost contour line detected from the captured image belongs, and the height position is determined. 4. The end position measuring method according to 3.  The end position measuring method according to claim 3, wherein the candidate portion includes an upper side edge and a lower side edge of a surface constituting the end part.  The end position measuring method according to claim 1, wherein photographing is performed by irradiating a measurement object with backlight illumination.  The end part position measuring method according to claim 1, wherein photographing is performed by a one-dimensional camera.  The edge part position measuring method according to claim 1, wherein photographing is performed by a two-dimensional camera.  A position in the direction intersecting the camera axis of the end of the measured object is calculated by the end position measuring method according to any one of claims 1 to 8, and based on the calculated position of the end A dimension measuring method characterized by calculating a body dimension.  The dimension measuring method according to claim 9, wherein each position is calculated by photographing a plurality of ends of the measured object, and the dimension of the measured object is calculated based on the calculated positional relationship between the plurality of ends.  The dimension measuring method according to claim 10, wherein each position is calculated by photographing a plurality of ends of the measurement object with different cameras.  The dimension measuring method according to claim 10, wherein each position is calculated by sequentially photographing a plurality of ends of the measurement object by moving the camera.  The dimension measuring method according to claim 10, wherein each position is calculated by moving the object to be measured and sequentially photographing a plurality of ends with a camera.  In a state where a predetermined part of the measurement object is in contact with a predetermined position reference portion, the measurement object is photographed to calculate the end position thereof, and the position reference portion position and the calculated end position are calculated. The dimension measuring method according to claim 9, wherein the dimension of the measurement object is calculated based on the above.  The dimension measuring method according to claim 9, wherein the measurement object is a cylindrical body.  The dimension measuring method according to claim 9, wherein the member to be measured is a photosensitive drum substrate. An imaging means for imaging a measured object having a height in the camera axial direction of the camera with a camera having an angle of view;
Contour detection means for detecting the outermost contour of the measured object from the captured image;
A height position discriminating means for discriminating the height position of the end of the measured object imaged as the outermost contour line according to the position of the detected outermost contour line in the captured image; By correcting the position of the outermost contour line in accordance with the height position of the outermost contour line, it intersects the camera axis direction of the end of the measured object being photographed as the outermost contour line An end position calculating means for calculating a position in a direction to perform;
An end position measuring device comprising: An end position measuring device according to claim 17,
Dimension calculating means for calculating the dimension of the measured object based on the calculated position of the end;
A dimension measuring device comprising:

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