JP2017173273A - Method of inspecting protrusions of cylindrical member, associated inspection device, and method of manufacturing cylindrical member including inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of inspecting protrusions of a cylindrical member, associated inspection device, and method of manufacturing a cylindrical member including the inspection method.SOLUTION: A method is provided for inspecting a cylindrical member having protrusions that are formed on an outer circumferential surface thereof to extend along a circumferential direction, the method comprising steps of; (1) irradiating the outer circumferential surface of the cylindrical member with light from a light irradiation device; (2) capturing images of at least a portion of the outer circumferential surface of the cylindrical member from a side opposite the light illumination device with respect to the cylindrical member using an image capturing device; (3) computing luminance of the images acquired by the image capturing device in each of two areas split by an axis of the cylindrical member: and (4) identifying the circumferential direction in which the protrusions extend based on a result of comparison between luminance of the first area and luminance of the second area.SELECTED DRAWING: Figure 11

Description

  The present invention relates to a method for inspecting a protrusion of a cylindrical member, an inspection apparatus therefor, and a method for manufacturing a cylindrical member including the inspection method.

  A copying machine or the like is provided with a paper feed roller so that paper can be separately fed and discharged. The paper feed roller needs to have a desired frictional force between the paper and the paper in order to convey the paper separately. Therefore, a polishing process is provided in the manufacturing process of the paper feed roller, and a protrusion is formed on the outer peripheral surface of the paper feed roller along a predetermined direction by polishing. The manufactured paper feed roller is attached to a copying machine or the like with a shaft inserted at the center of rotation. At this time, the paper feed roller needs to be correctly mounted so that the direction of the protruding portion is the direction in which the paper can be conveyed.

  Patent Document 1 discloses a paper feed roller in which a mark indicating the direction of a protruding portion is attached to an outer peripheral surface. When the operator attaches the paper feed roller to the copying machine or the like, the operator visually confirms this mark and attaches the paper feed roller in a predetermined direction.

  Patent Document 2 discloses a configuration in which a protruding member corresponding to the direction of the protruding portion is provided on the inner peripheral surface of the paper feed roller. When the operator attaches the paper feed roller to the copying machine or the like, the operator visually confirms the protruding member and attaches the paper feed roller in a predetermined direction.

JP 2003-267582 A JP2015-59026A

  However, in both Patent Document 1 and Patent Document 2, confirmation of the mark indicating the direction of the protruding portion of the paper feed roller, the protruding member, and the like is performed by visual observation of the operator. Therefore, if the operator makes an erroneous determination, there is an unavoidable possibility that the paper feed roller is attached in the wrong orientation in a copying machine or the like. Then, an object of this invention is to provide the manufacturing method of the cylindrical member containing the inspection method of the projection part of a cylindrical member, its inspection apparatus, and its inspection method.

The inspection method according to the first aspect of the present invention is a cylindrical member having a plurality of protrusions on the outer peripheral surface, and the plurality of protrusions extend along the circumferential direction. And includes the following steps.
(1) A step of irradiating the outer peripheral surface of the cylindrical member with a light beam by a light irradiation device.
(2) A step of photographing at least a part of the outer peripheral surface of the cylindrical member with an imaging device from the side facing the light irradiation device with the cylindrical member interposed therebetween.
(3) A step of calculating the luminance of each of the first region and the second region which are divided based on the axis of the cylindrical member in the image acquired by the imaging device.
(4) A step of determining a circumferential direction in which the protrusions extend based on a comparison result between the luminance of the first region and the luminance of the second region.

  An inspection method according to a second aspect of the present invention is the inspection method according to the first aspect, wherein the outer periphery of the protrusion is based on a comparison result between the luminance of the first region and the luminance of the second region. The method further includes a step of determining a rising state from the surface.

  The inspection method according to a third aspect of the present invention is the inspection method according to the first or second aspect, wherein in the step of determining a circumferential direction in which the protrusion extends, the luminance of the first region is the second region. When the brightness is larger than the brightness, the circumferential direction in which the protrusion extends is determined to be a direction along the first circumferential direction from the first area toward the second area.

The inspection method according to a fourth aspect of the present invention is the inspection method according to any one of the first to third aspects, wherein in the step of determining the circumferential direction in which the protrusion extends, the luminance of the second region is When the luminance of the first region is greater than the luminance, it is determined that the circumferential direction in which the protrusion extends is a direction along the second circumferential direction from the second region toward the first region.
The inspection method according to the fifth aspect of the present invention is the inspection method according to any one of the first to fourth aspects, wherein the light beam applied to the outer peripheral surface of the cylindrical member is parallel light.

  An inspection apparatus according to a sixth aspect of the present invention is a cylindrical member inspection apparatus that is a cylindrical member having a plurality of protrusions on an outer peripheral surface, and the plurality of protrusions extend along the circumferential direction. is there. The inspection device includes a light irradiation device, an imaging device, and an inspection unit. The light irradiation device irradiates the outer peripheral surface of the cylindrical member with a light beam. The imaging device photographs at least a part of the outer peripheral surface of the cylindrical member from the side facing the light irradiation device with the cylindrical member interposed therebetween. The inspection unit inspects the protrusion based on the image acquired by the imaging device. The inspection unit includes a luminance calculation unit and a determination unit. The luminance calculation unit calculates the luminance of each of the first region and the second region that are divided based on the axial center of the cylindrical member in the image acquired by the imaging device. The determination unit determines a circumferential direction in which the protrusion extends, based on a comparison result between the luminance of the first region and the luminance of the second region.

An inspection apparatus according to a seventh aspect of the present invention is the inspection apparatus according to the sixth aspect, further comprising a transport device that transports a plurality of cylindrical members. The light irradiation device and the imaging device are arranged to face each other in a direction intersecting with a conveyance direction of the plurality of cylindrical members with the conveyance device interposed therebetween.
The manufacturing method according to the eighth aspect of the present invention includes the following steps (1) to (5).

(1) A step of forming a cylindrical member which is a cylindrical member having a plurality of protrusions on the outer peripheral surface, and the plurality of protrusions extend along the circumferential direction.
(2) A step of irradiating the outer peripheral surface of the cylindrical member with a light beam by a light irradiation device.
(3) A step of photographing at least a part of the outer peripheral surface of the cylindrical member with an imaging device from the side facing the light irradiation device with the cylindrical member interposed therebetween.
(4) In the image acquired by the imaging device, calculating the luminance of each of the first region and the second region that are divided based on the axis of the cylindrical member.
(5) A step of determining a circumferential direction in which the protrusions extend based on a comparison result between the luminance of the first region and the luminance of the second region.

  A manufacturing method according to a ninth aspect of the present invention is the manufacturing method according to the eighth aspect, wherein the cylinder is based on the circumferential direction in which the protruding portion determined in the step of determining the circumferential direction in which the protruding portion extends. The method further includes the step of adjusting the vertical direction of the shaped member.

  A manufacturing method according to a tenth aspect of the present invention is the manufacturing method according to the ninth aspect, for supporting the rotation of the cylindrical member on the axis of the cylindrical member after the adjusting step. The method further includes the step of inserting a support bar.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the cylindrical member containing the inspection method of the projection part of a cylindrical member, its inspection apparatus, and its inspection method can be provided.

FIG. 3 is a perspective view of the paper feed roller 10. FIG. 2 is a cross-sectional view of the paper feeding roller 10 when a plurality of protrusions 12 extend in a first circumferential direction A, which is a cross section taken along the line II of FIG. 1. FIG. 2 is a cross-sectional view of the paper feeding roller 10 when a plurality of protrusions 12 extend in a second circumferential direction B, which is a cross section taken along the line II of FIG. 1 is a schematic diagram showing an inspection apparatus 100 that inspects a paper feed roller 10 according to the present embodiment. FIG. 4 is a top view of the light irradiation device 31, the imaging device 32, and the transport device 33 of the inspection apparatus 100. The front view of the light irradiation apparatus 31, the imaging device 32, and the conveying apparatus 33 of the test | inspection apparatus 100. FIG. 1 is a block diagram of an inspection apparatus 100. FIG. FIG. 3 is a schematic diagram showing an image 60 of a paper feed roller 10 taken by an imaging device 32. FIG. 2 is an explanatory diagram illustrating a state in which a light beam 70 is irradiated on a paper feed roller 10 that is a cross section taken along the line I-I in FIG. FIG. 2 is an explanatory diagram illustrating a state in which a light flux 70 is irradiated on a paper feed roller 10 which is a II cross section of FIG. 6 is an example of a flowchart illustrating an inspection method for the paper feed roller 10. An example of the flowchart which shows the manufacturing method of the paper feed roller. Explanatory drawing which shows another brightness | luminance calculation method in the brightness | luminance calculation part 41. FIG. Explanatory drawing which shows another brightness | luminance calculation method in the brightness | luminance calculation part 41. FIG. An image taken when the circumferential direction in which the protrusion 12 extends is along the second circumferential direction B of the paper feed roller 10 having a large rising angle of the protrusion 12. The result of binarizing the image of FIG. 15A. An image taken when the circumferential direction in which the protrusion 12 extends is along the first circumferential direction A for the paper feed roller 10 having a large rising angle of the protrusion 12. The result of binarizing the image of FIG. 16A. An image taken when the circumferential direction in which the protrusion 12 extends is along the second circumferential direction B for the paper feed roller 10 having a small rising angle of the protrusion 12. The result of binarizing the image of FIG. 17A. An image of the paper feed roller 10 having a small rising angle of the protrusion 12 taken when the circumferential direction of the protrusion 12 extends along the first circumferential direction A. The result of binarizing the image of FIG. 18A.

Hereinafter, a method and apparatus for inspecting a protrusion of a cylindrical member according to an embodiment of the present invention will be described with reference to the drawings. Moreover, the manufacturing method of the cylindrical member using the same inspection method is also demonstrated. Below, the cylindrical member which is the inspection target in the present embodiment will be described first, and then the inspection apparatus will be described.
<1. Cylindrical member>

  In the following embodiments, the paper feed roller 10 will be described as an example of a cylindrical member. The paper feed roller 10 is used in devices such as a copying machine, a facsimile, and a printer. Examples of the paper feed roller 10 include, but are not limited to, a paper feed roller that feeds paper into the device, a transport roller that transports paper in the device, and a paper discharge roller that ejects paper from the device. Further, the cylindrical member is not limited to the paper feed roller 10.

  FIG. 1 is a perspective view of the paper feed roller 10. FIG. 2 is a cross-sectional view taken along the line II of FIG. 1 and is a cross-sectional view of the paper feed roller 10 when a plurality of protrusions 12 extend in the first circumferential direction A. The first circumferential direction A is one circumferential direction along the cylindrical surface 11 a of the paper feed roller 10. FIG. 3 is a cross-sectional view taken along the line II of FIG. 1, and is a cross-sectional view of the paper feed roller 10 when the plurality of protrusions 12 extend in the second circumferential direction B facing the opposite side to the first circumferential direction. .

  As shown in FIG. 1, the paper feed roller 10 includes a cylindrical main body 11 and a plurality of protrusions 12. The cylindrical main body 11 is a cylindrical structure, has a cylindrical surface 11a on the side surface, and has a circular flat first flat surface 11b and a second flat surface 11c at both ends in the direction of the axis 13a. A cylindrical hole 13 is formed in the cylindrical main body 11 so as to penetrate the cylindrical main body 11 along the axis 13a. When used in each device described above, a support bar 19 is inserted into the cylindrical hole 13, and the rotation of the paper feed roller 10 is supported by the support bar 19.

  As will be described later, the plurality of protrusions 12 are formed when the paper feed roller 10 is manufactured, and are formed so as to protrude from the cylindrical surface 11 a of the cylindrical main body 11. More specifically, the protrusion 12 protrudes from the cylindrical surface 11a toward the outside of the paper feed roller 10 and extends along the circumferential direction of the cylindrical surface 11a. By forming the plurality of protrusions 12, a predetermined frictional force is generated between the paper feed roller 10 and the paper, and the paper can be fed one by one. Hereinafter, the outer peripheral surface 14 of the paper feed roller 10 is a generic term for the cylindrical surface 11 a and the protrusion 12.

  Such a paper feed roller 10 has a protruding portion 12 depending on which of the first and second flat surfaces 11b and 11c at both ends is placed with the first flat surface 11b or the second flat surface 11c facing down. The circumferential direction in which is extended differs. Therefore, an example in which the circumferential direction in which the protrusion 12 extends is different will be described with reference to FIGS. 2 and 3.

  In FIG. 2, the paper feed roller 10 is placed with the first flat surface 11 b facing down, for example, and a plurality of protrusions 12 extend along the first circumferential direction A. More specifically, the protrusion 12 in FIG. 2 is formed so as to protrude from the cylindrical surface 11 a toward the outer side in the radial direction of the paper feed roller 10. Further, the protrusion 12 in FIG. 2 is inclined so as to extend along the cylindrical surface 11a in the first circumferential direction A.

  On the other hand, in FIG. 3, the paper feed roller 10 is placed with the second flat surface 11 c facing down, and a plurality of protrusions 12 extend along the second circumferential direction B. More specifically, the protrusion 12 in FIG. 3 is formed so as to protrude from the cylindrical surface 11 a toward the outer side in the radial direction of the paper feed roller 10. Furthermore, the protrusion 12 in FIG. 3 is inclined so as to extend in the second circumferential direction B along the cylindrical surface 11a. In addition, the protrusion part 12 is not formed in the 1st and 2nd flat surfaces 11b and 11c.

  The paper feed roller 10 is made of, for example, a rubber composition having elasticity. For example, the paper feed roller 10 is made of natural rubber, ethylene-propylene-diene copolymer, urethane rubber, silicone rubber, polynorbornene, or the like. Although the manufacturing method is not particularly limited, for example, it is formed by extruding a rubber composition into a tube shape with an extruder to form a cylindrical body and polishing the outer peripheral surface thereof. The protrusion 12 is formed in the process of polishing the cylindrical body.

<2. Inspection device>
Next, the inspection apparatus 100 that inspects the paper feed roller 10 according to the present embodiment will be described. In this inspection apparatus 100, the direction of the protrusion 12 of the paper feed roller 10 is detected. First, the external configuration of the inspection apparatus 100 will be described.
(1) External configuration of the inspection apparatus 100 FIG. 4 is a schematic diagram illustrating the inspection apparatus 100 that inspects the paper feed roller 10 according to the present embodiment. FIG. 5 is a top view of the light irradiation device 31, the imaging device 32, and the transport device 33 of the inspection apparatus 100. FIG. 6 is a front view of the light irradiation device 31, the imaging device 32, and the transport device 33 of the inspection apparatus 100. FIG. 7 is a block diagram of the inspection apparatus 100.

  As illustrated in FIGS. 4 to 7, the inspection device 100 includes a control device 20, a light irradiation device 31, an imaging device 32, a transport device 33, a robot arm 34, and a manufacturing equipment 35. The control device 20 controls the light irradiation device 31, the imaging device 32, the transport device 33, the robot arm 34, and the manufacturing equipment 35.

  The transport device 33 is configured by a belt conveyor or the like, and transports the plurality of paper feed rollers 10 to a predetermined position based on the control of the control device 20. On the transport device 33, a plurality of paper feed rollers 10 with the first flat surface 11b or the second flat surface 11c down are arranged in a substantially straight line, and are transported along a predetermined transport direction C.

  The paper feed roller 10 transported to the downstream end of the transport device 33 is irradiated with light by the light irradiation device 31 for inspection of the protrusion 12 and is imaged by the imaging device 32. Thereafter, the paper feed roller 10 is removed from the transport device 33 by a robot arm 34 (not shown in FIG. 4).

  In the present embodiment, the light irradiation device 31, the paper feed roller 10, and the imaging device 32 are arranged substantially in a straight line, for example, in a direction D that intersects the transport direction C, as shown in FIG. 5. That is, the light irradiation device 31 and the imaging device 32 are disposed to face each other in a direction D substantially perpendicular to the transport direction C with the transport device 33 and the paper feed roller 10 interposed therebetween. Here, the light irradiation device 31 side with respect to the paper feed roller 10 is a back side, and the imaging device 32 side is a front side.

  When the paper feed roller 10 is transported to the downstream end of the transport device 33, the light irradiation device 31 irradiates the light flux on the back side of the outer peripheral surface 14 of the paper feed roller 10. On the other hand, the imaging device 32 photographs from the front side the outer peripheral surface 14 of the paper feed roller 10 irradiated with the light beam on the back side. The light beam applied to the paper feed roller 10 is, for example, parallel light whose incident optical axes are parallel to each other. Further, the imaging device 32 may be a color image imaging device or a monochrome image imaging device.

  Here, the paper feed roller 10 may be transported while being shifted from a prescribed position within the range of the transport device 33 along the light irradiation device 31 side or the imaging device 32 side, that is, along the direction D intersecting the transport direction C. is there. Thus, even if the position of the paper feed roller 10 is shifted in the direction D that intersects the transport direction C, the paper feed roller 10 is irradiated with the light flux from the direction D according to the above arrangement. Therefore, the irradiation range of the light flux on the paper feed roller 10 is substantially constant regardless of the presence / absence of the positional deviation. Therefore, according to the above arrangement, when the determination unit 42 described later determines the circumferential direction in which the protrusion 12 extends, it is possible to suppress an error in determination due to a difference in the irradiation range of the light flux and improve the determination accuracy.

  The manufacturing equipment 35 includes all equipment for manufacturing a paper feed roller. In addition to the equipment for manufacturing the paper feed roller on the upstream side of the transport device, the support bar 19 is provided in the cylindrical hole 13 of the paper feed roller after the inspection. Includes equipment to be inserted.

(2) Functional Configuration and Inspection Method of Control Device 20 Next, a functional configuration of the control device 20 included in the inspection device 100 will be described. As shown in FIG. 7, the control device 20 includes an inspection unit 40 and a device control unit 50. In addition, the apparatus control part 50 controls the light irradiation apparatus 31, the imaging device 32, the conveying apparatus 33, the robot arm 34, and the manufacturing apparatus 35, and makes each perform the above-mentioned process. Hereinafter, the configuration of the inspection unit 40 and the inspection method will be described in detail.

  First, the inspection unit 40 for inspecting the circumferential direction in which the protrusion 12 of the paper feed roller 10 extends will be described. The inspection unit 40 includes a luminance calculation unit 41 and a determination unit 42.

(2-1) Luminance calculation unit 41
A luminance calculation method performed by the luminance calculation unit 41 will be described with reference to FIG. FIG. 8 is a schematic diagram showing an image 60 of the paper feed roller 10 taken by the imaging device 32. The luminance calculation unit 41 acquires the image 60 of the paper feed roller 10 taken by the imaging device 32. This image 60 is an image of one side of the paper feed roller 10. That is, as described above, the paper feed roller 10 is photographed from the front side. As shown in FIG. 8, the image 60 includes a first area 60 a and a second area 60 b that are divided to the left and right around the axis 13 a of the paper feed roller 10. Then, the luminance calculation unit 41 calculates the luminance of each of the first region 60a and the second region 60b.

  The method for calculating the luminance of the first region 60a and the second region 60b is not particularly limited. For example, the luminance calculation unit 41 performs binarization processing on the image 60 with reference to predetermined luminance.

  In addition, since the imaging device 32 has acquired the image 60 of the entire region of the paper feed roller 10 in a side view, the areas of the first region 60a and the second region 60b, which are the targets for luminance comparison, can be maximized. Therefore, a region with high luminance can be acquired without omission. Further, it is possible to increase the difference in luminance that occurs when the circumferential directions in which the protrusions 12 extend in the first region 60a and the second region 60b are different. Thereby, the discrimination | determination precision of the circumferential direction where the projection part 12 is extended by the below-mentioned discrimination | determination part 42 can be improved.

(2-2) Discriminating unit 42
The determination unit 42 acquires the luminance of each of the first region 60a and the second region 60b from the luminance calculation unit 41. Further, the determination unit 42 determines the circumferential direction in which the protrusion 12 extends based on the comparison result between the luminance of the first region 60a and the luminance of the second region 60b.

(2-3) Inspection Method Next, an inspection method for the protrusion 12 will be described with reference to FIGS. FIG. 9 is a cross-sectional view taken along the line I-I in FIG. FIG. 10 is a cross-sectional view taken along the line I-I in FIG. FIG. 11 is an example of a flowchart illustrating an inspection method for the paper feed roller 10.

  First, the relationship between the paper feed roller 10 to be photographed and the acquired image 60 will be described. 9 and 10, the paper feed roller 10 is roughly divided into two equal parts on the left and right by an equipartition E passing through the axis 13 a and parallel to the light beam 70. Here, the right region is referred to as a first vertical region 80a, and the left region is referred to as a second vertical region 80b. The first vertical region 80a corresponds to the first region 60a when viewed from the imaging device 32 side, and the second vertical region 80b corresponds to the second region 60b when viewed from the imaging device 32 side. More specifically, on the basis of a line segment F that passes through the axis 13 a and is orthogonal to the equipartition line E, the imaging device 32 captures a side surface of the paper feed roller 10 on the imaging device 32 side as an image 60. get. Therefore, the imaging device 32 captures, as the first region 60a, the side surface corresponding to the first vertical region 80a and closer to the imaging device 32 than the line segment F. Further, the imaging device 32 captures the side surface on the imaging device 32 side of the line segment F corresponding to the second vertical region 80b as the second region 60b.

  As processing of the inspection method, first, as shown in FIG. 11, the light irradiation device 31 irradiates the paper feed roller 10 to be inspected with a light beam from the back side (step S24a). Next, the imaging device 32 photographs the paper feed roller 10 irradiated with the light beam from the front side (step S24b). Subsequently, the luminance calculating unit 41 acquires the image 60 of the paper feed roller 10 taken by the imaging device 32, and calculates the luminance of each of the first region 60a and the second region 60b in the image 60 (step S24c).

  Next, in describing the step of determining the direction in which the circumferential direction of the protrusion 12 extends (step S24d), the difference in the inspection processing depending on the direction of the protrusion 12 in FIGS. 9 and 10 will be described. First, the case where the protrusion part 12 is extended along the 1st circumferential direction A is demonstrated. In FIG. 9, the plurality of projections 12 of the paper feed roller 10 extend along the first circumferential direction A from the first region 60a toward the second region 60b. In this case, as shown in enlarged views IIa and IIb, the circumferential direction in which the protrusion 12 of the first region 60a extends is along the irradiation direction of the light beam 70, whereas as shown in enlarged views IIIa and IIIb. The circumferential direction in which the protrusion 12 of the second region 60b extends is along the opposite direction to the irradiation direction of the light beam 70.

  Thus, when observing on the basis of the irradiation direction of the light beam 70, the circumferential direction in which the protrusion 12 of the first region 60a extends is different from the circumferential direction in which the protrusion 12 of the second region 60b extends. This is because the circumferential direction in which the protrusions 12 in the first region 60a extend and the circumferential direction in which the protrusions 12 in the second region 60b extend are inversely symmetric with respect to the equipartition E.

  In this case, in the first region 60a, since the circumferential direction in which the protrusions 12 extend is along the irradiation direction of the light beam 70, the degree to which the progress of the light is hindered is small. On the other hand, in the second region 60b, the circumferential direction in which the protrusions 12 extend is along the direction opposite to the irradiation direction of the light beam 70, so that the progress of the light is largely obstructed. Therefore, in the first region 60a and the second region 60b, the irradiated light beam 70 travels along the light irradiation direction, or the irradiated light beam 70 travels along the light irradiation direction. The difference arises. As a result, a difference occurs between the luminance of the first region 60a and the luminance of the second region 60b. Specifically, the brightness of the first area 60a is greater than the brightness of the second area 60b. As a result, by comparing the luminance of the first region 60a and the luminance of the second region 60b, the determination unit 42 can determine that the circumferential direction in which the protrusion 12 extends is the first circumferential direction A (step S24d). .

  Next, the case where the projection part 12 is extended along the 2nd circumferential direction B is demonstrated. In FIG. 10, the circumferential direction in which the protrusion 12 extends is different from that in FIG. 9, and the rest is the same. Therefore, as shown in the enlarged views IVa and IVb, the circumferential direction in which the protrusion 12 of the first region 60a extends is in the opposite direction to the irradiation direction of the light beam 70, whereas the enlarged views Va and Vb. As shown, the circumferential direction in which the protrusion 12 of the second region 60 b extends is along the irradiation direction of the light beam 70.

  In this case, in the first region 60a, the circumferential direction in which the protrusions 12 extend is along the direction opposite to the irradiation direction of the light beam 70, so that the progress of the light is largely disturbed. On the other hand, in the second region 60b, since the circumferential direction in which the protrusion 12 extends is along the irradiation direction of the light beam 70, the degree to which the light travels is obstructed is small. Therefore, similarly to the description of FIG. 9, a difference occurs between the luminance of the first region 60a and the luminance of the second region 60b, and the luminance of the second region 60b is larger than the luminance of the first region 60a. As a result, by comparing the luminance of the first region 60a and the luminance of the second region 60b, the determination unit 42 can determine that the circumferential direction in which the protrusion 12 extends is the second circumferential direction B (step S24d). .

  According to the above inspection method, the circumferential direction in which the protruding portion 12 extends can be automatically determined instead of the visual and touch of the operator. Therefore, it is possible to accurately determine the circumferential direction in which the protrusion 12 extends. As a result, in which direction the paper feed roller 10 is arranged, for example, on the transport device 33, that is, the paper feed roller 10 is arranged with the first flat surface 11b down, or the second flat surface 11c down. It is possible to determine whether it is arranged.

  “Along the direction” and “... direction” include not only “parallel to the direction” but also “almost along the direction”. Therefore, for example, when the circumferential direction in which the protrusion 12 extends is the first circumferential direction A, the circumferential direction in which the protrusion 12 in the first region 60a extends may be a direction substantially along the irradiation direction of the light flux 70, and the second region The circumferential direction in which the protrusion 12 of 60b extends may be substantially in the opposite direction to the irradiation direction of the light beam 70. Further, the circumferential direction in which the protrusion 12 of the first region 60a extends may be along the irradiation direction of the light flux 70 as a whole or on average. The same applies when the circumferential direction in which the protrusion 12 extends is the second circumferential direction B.

<3. Manufacturing Method of Paper Feed Roller 10>
Hereinafter, a method for manufacturing the paper feed roller 10 using the above-described inspection method will be described with reference to FIG. However, the above-described inspection method is not limited to the example here, and can be used for any application that requires inspection of the paper feed roller 10.

  FIG. 12 is an example of a flowchart illustrating a method for manufacturing the paper feed roller 10. First, the manufacturing device 35 inputs the material of the paper feed roller 10 into a kneader to generate a rubber composition (step S21), and the rubber composition is extruded into a tube shape by an extruder to generate a cylindrical body. (Step S22). Next, the manufacturing device 35 polishes the cylindrical body along the circumferential direction to form the protrusion 12 (step S23). For the paper feed roller 10 on which the protrusions 12 are formed, an inspection process consisting of the aforementioned steps S24a to S24d is performed (step S24).

  When the inspection process is completed, processing according to the inspection result in the inspection process is performed (step S25). For example, when the rotation direction of the paper feed roller 10 is different from the circumferential direction in which the protrusions 12 extend, the robot arm 34 adjusts the top and bottom of the paper feed roller 10 upside down, and the first flat surface 11b or the second flat surface. Adjust so that 11c faces downward. For example, when the rotation direction of the paper feed roller is defined in advance as the first circumferential direction A, but the circumferential direction in which the protrusion 12 extends is determined as the second circumferential direction B, the robot arm 34 The feed roller 10 is adjusted upside down. Thereby, the direction of the paper feed roller 10 can be adjusted to the correct direction along the first circumferential direction A, which is the rotational direction.

  On the other hand, when the rotation direction of the paper feed roller 10 coincides with the circumferential direction in which the protrusion 12 extends, the paper feed roller 10 is transported to a predetermined position by the robot arm 34 or the like, for example, and the paper feed roller 10 is kept up and down. Proceed to the next process.

Finally, with respect to the paper feed roller 10 that has proceeded to the next process, the manufacturing device 35 inserts the support bar 19 that supports the rotation of the paper feed roller 10 into the cylindrical hole 13 at the center (step S26).
Thus, the manufacturing process of the paper feed roller 10 is completed.

According to the manufacturing process described above, the support rod 19 can be attached to the paper feed roller 10 in a correct state in which the rotation direction of the paper feed roller 10 corresponds to the circumferential direction in which the protrusions 12 extend.
<4. Features>
According to the present embodiment, as described above, the protrusion 12 is formed along the circumferential direction of the paper feed roller 10. The paper feed roller 10 is irradiated with a light beam 70 to inspect the circumferential direction in which the protrusion 12 extends. In this case, when observing on the basis of the irradiation direction of the light beam 70 irradiated on the paper feed roller 10, for example, the circumferential direction in which the protrusion 12 of the first region 60a on the right side view extends and the second region 60b on the left side view. The direction is different from the circumferential direction in which the protrusion 12 extends.
Here, for example, on the outer peripheral surface 14 of the paper feed roller 10, it is assumed that the plurality of protrusions 12 extend along the first circumferential direction A from the first region 60a toward the second region 60b. In this case, the circumferential direction in which the protrusion 12 in the first region 60a extends is along the irradiation direction of the light beam 70, whereas the circumferential direction in which the protrusion 12 in the second region 60b extends is the irradiation direction of the light beam 70. Is in the opposite direction. This is because the circumferential direction in which the protrusions 12 in the first region 60 a extend and the circumferential direction in which the protrusions 12 in the second region 60 b extend are reversed symmetrical with respect to the axis 13 a of the paper feed roller 10. It is.
And in the 1st field 60a, since the peripheral direction where projection part 12 extends is along the irradiation direction of light beam 70, the extent to which the progress of the light is obstructed is small. On the other hand, in the second region 60b, the circumferential direction in which the protrusions 12 extend is along the direction opposite to the irradiation direction of the light beam 70, so that the progress of the light is largely obstructed. Therefore, in the first region 60a and the second region 60b, the irradiated light beam 70 travels along the light irradiation direction, or the irradiated light beam 70 travels along the light irradiation direction. The difference arises. As a result, there is a difference between the luminance of the first region 60a imaged by the imaging device 32 and the luminance of the second region 60b. Specifically, when the protrusion 12 extends along the first circumferential direction A, the luminance of the first region 60a is greater than the luminance of the second region 60b. As a result, by comparing the luminance of the first region 60a with the luminance of the second region 60b, it is possible to determine the circumferential direction in which the protrusion 12 extends.
Contrary to the above, for example, on the outer peripheral surface 14 of the paper feed roller 10, the plurality of protrusions 12 extend along the second circumferential direction B from the second region 60b toward the first region 60a. To do. In this case, the circumferential direction in which the protrusion 12 in the first region 60a extends is in the opposite direction to the irradiation direction of the light beam 70, whereas the circumferential direction in which the protrusion 12 in the second region 60b extends is Along the irradiation direction of the light beam 70. In this case, based on the same principle as described above, the luminance of the second region 60b is larger than the luminance of the first region 60a. As a result, by comparing the luminance of the first region 60a with the luminance of the second region 60b, it is possible to determine the circumferential direction in which the protrusion 12 extends.
According to the inspection method described above, the circumferential direction in which the protruding portion 12 extends can be automatically determined instead of the operator's visual inspection and touch. Therefore, it is possible to accurately determine the circumferential direction in which the protruding portion 12 extends, and as a result, it is possible to determine the vertical direction of the paper feed roller 10.
<5. Modification>

As mentioned above, although one Embodiment of this invention was described, this invention is not limited to the said embodiment, A various change is possible unless it deviates from the meaning. For example, the following changes can be made. Moreover, the gist of the following modifications can be combined as appropriate.
<5-1>

In the above embodiment, the determination unit 42 determines the circumferential direction in which the protrusion 12 extends. However, the determination unit 42 may determine the rising state of the protrusion 12 from the cylindrical surface 11a instead of or in addition to the determination of the circumferential direction in which the protrusion 12 extends. The discrimination result of the rising state of the protrusion 12 is also based on a comparison result between the luminance of the first region 60a and the luminance of the second region 60b.
Hereinafter, a method for determining the rising state of the protrusion 12 will be described.

  In the image 60 of FIG. 8, when the difference between the luminance of the first region 60a and the luminance of the second region 60b is small, or when there is no difference, the rising angle of the protrusion 12 with respect to the cylindrical surface 11a may be small. I understand. That is, it can be seen that the protrusion 12 has fallen along the cylindrical surface 11a of the paper feed roller 10, and as a result, the frictional force when the protrusion 12 comes into contact with another surface is reduced.

  For example, when the protrusion 12 rises from the cylindrical surface 11a at a certain large angle, there is a certain large difference between the luminance of the first region 60a and the luminance of the second region 60b. For example, the circumferential direction in which the protrusion 12 extends in the first region 60 a is along the irradiation direction of the light beam 70, and the circumferential direction in which the protrusion 12 extends in the second region 60 b is in the opposite direction to the irradiation direction of the light beam 70. Suppose that In this case, in the first region 60a, the light is less disturbed by the protrusions 12 extending along the irradiation direction.

  On the other hand, in the second region 60b, the light is largely prevented from advancing by the protrusion 12 extending along the direction opposite to the irradiation direction. Therefore, when the protrusion 12 rises from the cylindrical surface 11a at a certain large angle, a certain large luminance difference is generated between the first region 60a and the second region 60b. However, when the rising angle of the protrusion 12 is small, the difference between the degree to which the light travels in the first region 60a is disturbed and the degree to which the light travels in the second region 60b is small. Therefore, the difference between the luminance of the first region 60a and the luminance of the second region 60b is small.

Therefore, the determination unit 42 can determine the rising state of the protrusion 12 from the cylindrical surface 11a by comparing the magnitude of the magnitude relationship between the luminance of the first region 60a and the luminance of the second region 60b. Thereby, the good and bad of the rising state of the projection part 12 can be inspected.
<5-2>

  In the above embodiment, the image 60 in FIG. 8 is an image of the entire area of the paper feed roller 10 that can be viewed from the side. The image 60 is divided into two equal parts, the first region 60a and the second region 60b, with the axis 13a as a reference. However, the first region 60a and the second region 60b may be limited to predetermined regions.

  FIG. 13 is an explanatory diagram showing another luminance calculation method in the luminance calculation unit 41. For example, the luminance calculation unit 41 calculates an area Aa of a region having a predetermined luminance α or higher in the first region 60a of the image 60 in FIG. Similarly, the luminance calculation unit 41 calculates the area Ab of a region having a predetermined luminance α or higher in the second region 60b of the image 60 in FIG. The determination unit 42 compares the sizes of the area 60Aa and the area 60Ab to determine the circumferential direction in which the protrusion 12 extends. For example, when the area 60Aa is larger than the area 60Ab, the determination unit 42 determines that the circumferential direction in which the protrusion 12 extends is the first circumferential direction A from the first region 60a toward the second region 60b. In this determination method, the protrusion 12 is along the irradiation direction of the light beam in a region where the high luminance area is wide, and the protrusion 12 is along the direction opposite to the irradiation direction of the light beam in a region where the high luminance area is small. Is based on being. According to such a calculation method, the luminance region to be calculated can be limited, so that the calculation amount by luminance calculation can be reduced and the luminance calculation can be speeded up.

FIG. 14 is an explanatory diagram showing another luminance calculation method in the luminance calculation unit 41. The luminance calculation unit 41 extracts the first extraction area 61a from the first area 60a. For example, the first extraction region 61a is a region having a high luminance in the first region 60a. In addition, the luminance calculation unit 41 extracts a second extraction region 61b at a position symmetrical to the first extraction region 61a from the second region 60b with reference to the axis 13a. The first extraction area 61a and the second extraction area 61b have the same area. The luminance calculation unit 41 calculates the luminance of the first extraction area 61a and the luminance of the second extraction area 61b. The determination unit 42 compares the luminance of the first extraction region 61a with the luminance of the second extraction region 61b, and determines the circumferential direction in which the protrusion 12 extends. For example, when the luminance of the first extraction region 61a is higher than the luminance of the second extraction region 61b, the determination unit 42 determines that the circumferential direction in which the protrusion 12 extends is the first direction from the first region 60a toward the second region 60b. The circumferential direction A is determined. Thereby, since the area | region of the luminance which should be calculated can be limited, the calculation amount by luminance calculation can be reduced and the calculation of luminance can be sped up.
<5-3>

  In the above-described embodiment, the light irradiation device 31, the paper feed roller 10, and the imaging device 32 are arranged substantially in a straight line, for example, in a direction D that intersects the conveyance direction C, as shown in FIG. However, it suffices that the paper feed roller 10 is irradiated with the light flux 70 and the imaging device 32 can photograph at least a part of the side surface of the paper feed roller 10. Therefore, for example, when the imaging device 32 and the paper feed roller 10 are positioned on a straight line, the light irradiation device 31 may irradiate the paper feed roller 10 with the light flux 70 from an oblique direction with respect to the straight line. Good. Further, when the light irradiation device 31 and the paper feed roller 10 are located on a straight line, the imaging device 32 may photograph the paper feed roller 10 from an oblique direction with respect to the straight line.

When the imaging device 32 and the light irradiation device 31 are on the same side with respect to the paper feed roller 10, the light flux 70 is irradiated from the imaging device 32 side. In this case, the imaging device 32 directly captures irregular reflection by the protrusion 12 on the side facing the imaging device 32. In this way, when the light flux 70 is irradiated from the imaging device 32 side, the circumferential direction in which the protrusion 12 extends with respect to the axis 13a of the paper feed roller 10 is a region where the circumferential direction is opposite to the light irradiation direction. It is considered that irregular reflection is likely to occur. This irregular reflection also proceeds to the remaining region, that is, the region in which the circumferential direction in which the protrusion 12 extends is along the light irradiation direction with the axis 13a as a reference. Therefore, the difference between the luminance of the first region 60a and the luminance of the second region 60b may be reduced. Alternatively, the relationship between the luminance of the first region 60a and the luminance of the second region 60b may not be quantitative due to irregular reflection. By arranging the image pickup device 32, the paper feed roller 10, and the light irradiation device 31 in order on a straight line, the paper feed roller 10 is irradiated with light from a different direction from the image pickup device 32 side. Therefore, the imaging device 32 can capture an image of the paper feed roller 10 in a state where irregular reflection is suppressed. Thereby, the difference between the luminance of the first region 60a and the luminance of the second region 60b can be acquired more accurately, and the circumferential direction in which the protrusion 12 extends can be determined more accurately.
<5-4>

  In the above embodiment, the luminance calculation unit 41 performs binarization processing on the image 60. The luminance calculation unit 41 may perform processing for enhancing the luminance contrast of the image 60 in addition to the processing of the above embodiment.

  Examples of the process for enhancing the brightness contrast include the following processes. When the imaging device 32 is a color image imaging device, the luminance calculation unit 41 removes saturation and hue, and acquires an image based on brightness. Note that this processing is not necessary when the imaging device 32 is a monochrome image imaging device. In addition, the luminance calculation unit 41 may clarify the feature amount corresponding to the luminance using an FFT (Fast Fourier Transform) filter. Further, the luminance calculation unit 41 may mask a region other than the image 60 corresponding to the paper feed roller 10 and remove a signal from an unnecessary region. The luminance calculation unit 41 may combine these processes to acquire a monochrome image 60, process it with an FFT filter, mask an area other than the image 60, and perform a binarization process.

  In addition, the luminance calculation unit 41 may perform a gray filter process between the FFT filter process and the mask process other than the image 60. The process using the gray filter is a process for making the colors in the image 60 inconspicuous. Thereby, the feature amount corresponding to the luminance can be further clarified.

As described above, by enhancing the luminance contrast in the image 60 and then calculating the luminance of the first region 60a and the second region 60b, the difference between the luminance of the first region 60a and the luminance of the second region 60b is obtained. growing. Therefore, the determination unit 42 can more accurately determine the circumferential direction in which the protrusion 12 extends.
<5-5>

In the above embodiment, the paper feed roller 10 is a cylindrical body. However, the cylindrical body as the paper feed roller 10 may include a member that is entirely cylindrical and a member that is at least partially cylindrical. The member having at least a part of a cylindrical shape includes a member in which a part is cut out in a whole cylindrical member. For example, in a cross-sectional view intersecting with the axis 13a, a member in which a ¼ portion is cut out with respect to the axis 13a and only a ¾ portion is formed in a cylindrical shape can be used.
The cylindrical body includes not only a cylindrical body but also an elliptical cylindrical body when viewed from above and a polygonal cylindrical body that can approximate a cylindrical shape when viewed from above.

In the case of a member having a cylindrical shape as a whole, for example, when the paper feed roller 10 is attached to a copying machine or the like, the paper feed function can be realized by rotating the paper feed roller 10 in one direction. The paper feed direction can be changed by rotating in the direction. Further, when a member having at least a part of a cylindrical shape is attached to a copying machine or the like, the paper feeding direction can be changed by rotating forward or backward using the cylindrical part.
<5-6>

  In the above embodiment, the positional relationship between the central axis of the light beam 70 irradiated from the light irradiation device 31 to the paper feed roller 10 and the axis 13a of the paper feed roller 10 is not particularly defined. However, the position of the central axis of the light beam 70 and the axis 13a of the paper feed roller 10 may overlap in a side view of the paper feed roller 10.

In this case, since the axial center 13a of the paper feed roller 10 and the central axis of the light beam 70 are superimposed in a side view, the light flux 70 can be irradiated to the paper feed roller 10 substantially uniformly left and right around the axis 13a. . That is, in the image 60, the first region 60a and the second region 60b can be irradiated with the light flux 70 substantially uniformly. Therefore, the unevenness of the irradiated light beam 70 can be eliminated, and the circumferential direction in which the protrusion 12 extends can be more accurately determined.
<5-7>

  In the above embodiment, in the transport device 33, the paper feed roller 10 is placed with the first flat surface 11b or the second flat surface 11c facing down. In this case, as shown in FIG. 8, in the image 60, the first region 60 a and the second region 60 b are regions adjacent to the longitudinal axis 13 a of the paper feed roller 10 in the left-right direction.

However, the paper feed roller 10 may be conveyed in the lateral direction. For example, the paper feed roller 10 is conveyed in a state where the first flat surface 11b and the second flat surface 11c at both ends are sandwiched and floated so that the axis 13a is in the horizontal direction, and the light flux 70 is irradiated. The imaging device 32 captures images of the first region 60 a and the second region 60 b that are adjacent in the vertical direction with respect to the lateral axis 13 a of the paper feed roller 10. Then, as in the above embodiment, the protrusion 12 is inspected by comparing the luminance of the first region 60a and the luminance of the second region 60b.
<5-8>

  In the above embodiment, the paper feed roller 10 is taken as an example of the cylindrical member, but the cylindrical member is not limited to this. Any cylindrical member may be used as long as it has a plurality of protrusions 12 formed on the outer circumferential surface 14 extending from the inside to the outside of the cylindrical member and extending along the circumferential direction. Good. In addition, examples of the cylindrical member include a member for transporting a predetermined object by rotation and friction by the protrusion 12 such as a rotating roller used for rotation of the belt conveyor.

  Further, the shape and size of the protruding portion 12 of the cylindrical member are not limited as long as it extends from the inside of the cylindrical member to the outside and extends along the circumferential direction. Therefore, the protrusion 12 may be, for example, a brush hair. Moreover, the hardness of the projection part 12 should just be according to the target object which contacts the projection part 12, and is not limited.

  Moreover, in the said embodiment, although the cylindrical member and the projection part 12 are formed with rubber | gum, such as natural rubber, the material of a cylindrical member and the projection part 12 is not limited to this. For example, the cylindrical member and the protrusion 12 may be made of a resin such as a thermosetting resin, wooden, plastic, metal, or the like. Further, the cylindrical member and the protruding portion 12 do not need to be integrally formed of one type of material. For example, the inside of the cylindrical member is made of plastic or the like, the outside of the cylindrical member covering the inside of the cylindrical member is made of a material such as rubber, and the protrusion 12 is formed on the outside of the cylindrical member. May be.

Further, in the paper feed roller 10 of the above embodiment, the cylindrical hole 13 is formed at the center thereof, but the cylindrical hole 13 is not necessarily formed. Further, even when the cylindrical hole 13 is formed in the cylindrical member, the cylindrical hole 13 does not need to be formed in the central portion, and may be formed at a position off the central portion. .
<5-9>
In the above embodiment, the light irradiation device 31 irradiates the paper feed roller 10 with parallel light whose incident optical axes are parallel to each other. However, the irradiated light beam is not limited to parallel light, and may be diffused light. However, in the case of parallel light, compared to the case of diffused light, the paper feed roller 10 is irradiated with substantially uniform light with reduced illuminance unevenness. Therefore, it is possible to suppress a decrease in inspection accuracy due to illuminance unevenness.
<5-10>
In the above embodiment, the paper feed roller 10 to be inspected is located at the downstream end of the transport device 33, and the light irradiation device 31 and the imaging device 32 are arranged corresponding to the paper feed roller 10. . However, the position of the paper feed roller 10 to be inspected is not limited to this, and may be any position in the transport device 33. In addition, the light irradiation device 31 and the imaging device 32 may be disposed corresponding to the paper feed roller 10 to be inspected, and do not need to be disposed at the downstream end of the transport device 33 as described above. .

Examples of the present invention will be described below. However, the present invention is not limited to the following examples.
As an inspection object, a substantially cylindrical paper feed roller 10 having a width of about 30 mm and a diameter of about 25 mm was prepared. Further, as the inspection object, the paper feed roller 10 in which the projection 12 rises from the cylindrical surface 11a at a certain large angle, and the paper feed roller in which the projection 12 rises at a small angle with respect to the cylindrical surface 11a. 10 was used. Further, as the inspection, for each of the paper feeding rollers 10 described above, when the circumferential direction in which the protruding portion 12 extends is along the first circumferential direction A, the circumferential direction in which the protruding portion 12 extends is along the second circumferential direction B. And if you went about.

  The inspection results of the inspection method using the present invention will be described below with reference to FIGS. 15A to 18B. FIG. 15A is an image taken when the circumferential direction in which the protruding portion 12 extends is along the second circumferential direction B for the paper feed roller 10 in which the rising angle of the protruding portion 12 is large. FIG. 15B shows the result of binarizing the image of FIG. 15A. FIG. 16A is an image taken for the paper feed roller 10 having a large rising angle of the protrusion 12 when the circumferential direction in which the protrusion 12 extends is along the first circumferential direction A. FIG. FIG. 16B shows the result of binarizing the image of FIG. 16A. FIG. 17A is an image taken when the circumferential direction in which the protrusion 12 extends is along the second circumferential direction B for the paper feed roller 10 with a small rising angle of the protrusion 12. FIG. 17B shows the result of binarizing the image of FIG. 17A. FIG. 18A is an image taken when the circumferential direction in which the protrusion 12 extends is along the first circumferential direction A for the paper feed roller 10 having a small rising angle of the protrusion 12. FIG. 18B shows the result of binarizing the image of FIG. 18A.

  Referring to FIG. 15B obtained by binarizing FIG. 15A, the luminance of the second region 60b is larger than the luminance of the first region 60a. That is, the second area 60b has a higher luminance and a white area. Therefore, the determination unit 42 determines that the circumferential direction in which the protrusion 12 of the paper feed roller 10 extends is along the second circumferential direction B. The determination result corresponds to the inspection target in FIGS. 15A and 15B being the paper feed roller 10 in which the circumferential direction in which the protruding portion 12 extends is along the second circumferential direction B. You can see that

  Referring to FIG. 16B obtained by binarizing FIG. 16A, the luminance of the first region 60a is larger than the luminance of the second region 60b. That is, the first region 60a has a higher brightness and a white region. Therefore, the determination unit 42 determines that the circumferential direction in which the protrusion 12 of the paper feed roller 10 extends is along the first circumferential direction A. This discrimination result corresponds to the paper feed roller 10 in which the circumferential direction in which the protrusion 12 extends in FIG. 16A is along the first circumferential direction A, and it can be seen that the discrimination is performed accurately. .

  Referring to FIG. 17B obtained by binarizing FIG. 17A, the luminance of the second region 60b is larger than the luminance of the first region 60a. That is, the second area 60b has a higher luminance and a white area. Therefore, the determination unit 42 determines that the circumferential direction in which the protrusion 12 of the paper feed roller 10 extends is along the second circumferential direction B. This discrimination result corresponds to the paper feed roller 10 in which the circumferential direction in which the protrusion 12 extends in FIG. 17A is along the second circumferential direction B, and it can be seen that the discrimination is performed accurately. .

  Referring to FIG. 18B obtained by binarizing FIG. 18A, the luminance of the first region 60a is larger than the luminance of the second region 60b. That is, the first region 60a has a higher brightness and a white region. Therefore, the determination unit 42 determines that the circumferential direction in which the protrusion 12 of the paper feed roller 10 extends is along the first circumferential direction A. This discrimination result corresponds to the paper feed roller 10 in which the circumferential direction in which the protrusion 12 extends in FIG. 18A is along the first circumferential direction A, and it can be seen that the discrimination is accurately performed. .

DESCRIPTION OF SYMBOLS 10 Paper feed roller 11 Cylindrical surface 14 Outer peripheral surface 31 Light irradiation apparatus 32 Imaging device 40 Inspection part 41 Luminance calculation part 42 Discriminating part 50 Device control part 60a 1st area | region 60b 2nd area | region

Claims (10)

It is a cylindrical member having a plurality of protrusions on the outer peripheral surface, and the plurality of protrusions extend along the circumferential direction.
Irradiating the outer peripheral surface of the cylindrical member with a light beam by a light irradiation device;
Photographing at least a part of the outer peripheral surface of the cylindrical member from the side facing the light irradiation device across the cylindrical member with an imaging device;
Calculating the luminance of each of the first region and the second region divided on the basis of the axis of the cylindrical member in the image acquired by the imaging device;
Determining a circumferential direction in which the protrusion extends, based on a comparison result between the luminance of the first region and the luminance of the second region;
An inspection method comprising:   The inspection method according to claim 1, further comprising: determining a rising state of the protrusion from the outer peripheral surface based on a comparison result between the luminance of the first region and the luminance of the second region.   In the step of determining the circumferential direction in which the protrusion extends, when the luminance of the first region is higher than the luminance of the second region, the circumferential direction in which the protrusion extends extends from the first region to the second region. The inspection method according to claim 1, wherein the inspection method is determined to be a direction along a first circumferential direction toward the head.   In the step of determining the circumferential direction in which the protrusion extends, when the luminance of the second region is higher than the luminance of the first region, the circumferential direction in which the protrusion extends extends from the second region to the first region. The test | inspection method in any one of Claims 1-3 which discriminate | determines that it is a direction along the 2nd circumferential direction which goes to.   The inspection method according to claim 1, wherein the light beam applied to the outer peripheral surface of the cylindrical member is parallel light. It is a cylindrical member having a plurality of protrusions on the outer peripheral surface, and the plurality of protrusions extend along the circumferential direction.
A light irradiation device for irradiating the outer peripheral surface of the cylindrical member with a light beam;
An imaging device that photographs at least a part of the outer peripheral surface of the cylindrical member from the side facing the light irradiation device across the cylindrical member;
An inspection unit for inspecting the protrusion based on an image acquired by the imaging device;
With
The inspection unit
In the image acquired by the imaging device, a luminance calculation unit that calculates the luminance of each of the first region and the second region that are divided based on the axis of the cylindrical member;
A discriminating unit for discriminating a circumferential direction in which the protrusion extends, based on a comparison result between the luminance of the first region and the luminance of the second region;
Including inspection equipment. A transport device for transporting a plurality of cylindrical members;
The inspection apparatus according to claim 6, wherein the light irradiation device and the imaging device are disposed to face each other in a direction intersecting a conveyance direction of the plurality of cylindrical members with the conveyance device interposed therebetween. A cylindrical member having a plurality of protrusions on the outer peripheral surface, the plurality of protrusions extending along the circumferential direction, forming a cylindrical member;
Irradiating the outer peripheral surface of the cylindrical member with a light beam by a light irradiation device;
Photographing at least a part of the outer peripheral surface of the cylindrical member from the side facing the light irradiation device across the cylindrical member with an imaging device;
Calculating the luminance of each of the first region and the second region divided on the basis of the axis of the cylindrical member in the image acquired by the imaging device;
Determining a circumferential direction in which the protrusion extends, based on a comparison result between the luminance of the first region and the luminance of the second region;
A manufacturing method comprising:   The manufacturing method according to claim 8, further comprising the step of adjusting the vertical direction of the cylindrical member based on the circumferential direction in which the protruding portion determined in the step of determining the circumferential direction in which the protruding portion extends.   The manufacturing method according to claim 9, further comprising a step of inserting a support rod for supporting the rotation of the cylindrical member into the axial center of the cylindrical member after the adjusting step.