JP2023078616A - Inspection method and inspection device of cylindrical body surface - Google Patents

Abstract

To provide an inspection method of a cylindrical body surface and an inspection device of the cylindrical body surface which can detect a minute defect even if the cylindrical body surface is made of a material that is transparent or close to transparent or determine the type of the detected defect.SOLUTION: An inspection method of a cylindrical body surface according to the present invention executes: a first step of irradiating a cylindrical body with light in such a state that the cylindrical body is rotated, receiving reflection light, which is the light emitted and reflected on the surface of the cylindrical body, with one-dimensional imaging means, and stopping the rotation of the cylindrical body when a defect on the surface of the cylindrical body is detected from an image captured by the one-dimensional imaging means; and a second step of irradiating the cylindrical body with light from an angle at which the irradiation angle to the surface of the cylindrical body is different from the irradiation angle of the light emitted to the surface of the cylindrical body in the first step in such a state that the cylindrical body is stopped, receiving reflection light, which is the light emitted and reflected on the surface of the cylindrical body, with two-dimensional imaging means and imaging the position of the defect detected in the first step with the two-dimensional imaging means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a method and apparatus for detecting imperfections in a cylinder surface.

In the manufacturing process of cylindrical bodies such as rubber rollers, it is a problem that defects such as scratches and dents occur on the surface thereof. Although the required surface properties of the cylindrical body differ depending on the application, in the case of applications such as rollers for film production where scratches and dents are not desired, an inspection method and inspection apparatus for inspecting the surface with high accuracy is required.

Conventionally, when inspecting for such defects, in addition to visual inspection by human eyes, the inspection was performed by detecting the surface of the cylindrical body by some method and determining the presence or absence of defects. For example, as in Patent Document 1, a technique for measuring the surface of a cylindrical body using a distance sensor, and as in Patent Document 2, light leaking from a gap between a cylindrical body and two cylindrical bodies for measurement is measured. There is a technology for detecting and confirming the presence or absence of unevenness on the surface.

JP-A-4-303702 Japanese Patent Application Laid-Open No. 2003-149168

However, the techniques of Patent Documents 1 and 2 have the following problems. Since Patent Document 1 uses a rangefinder using a laser beam or the like, if the material of the surface of the cylinder is transparent or nearly transparent, the light is transmitted, and information on the inside of the surface of the cylinder, for example, from internal foreign matter, etc., is transmitted. Reflected light is detected, and the distance to the surface cannot be accurately measured, resulting in a large number of false detections. In addition, although Patent Document 2 detects the leakage of light from the defective portion, this also detects irregularities because light leaks from other than the defective portion of the cylindrical body if the material of the surface of the cylindrical body is transparent rubber or the like. can no longer be done.

The present invention is intended to solve the above-described problems of the prior art, and is a cylindrical body that can detect minute defects even if the surface of the cylindrical body is made of transparent or nearly transparent material, and can discriminate the type of the detected defects. A surface inspection apparatus and method for inspecting a cylinder are provided.

A method for inspecting the surface of a cylindrical body according to the present invention for solving the above problems is a method for inspecting the surface of a cylindrical body,
Light is applied to the cylindrical body while the cylindrical body is rotated, and the reflected light reflected by the surface of the cylindrical body is received by a one-dimensional imaging means, and the one-dimensional imaging means receives the reflected light. a first step of stopping the rotation of the cylindrical body when a defect on the surface of the cylindrical body is detected from the captured image;
Next, while the cylindrical body is stopped, the cylindrical body is irradiated at an irradiation angle different from the irradiation angle of the light applied to the surface of the cylindrical body in the first procedure. light is applied to the surface of the cylinder, the reflected light reflected by the surface of the cylindrical body is received by the two-dimensional imaging means, and the position of the defect detected in the first procedure is detected by the two-dimensional imaging means. A second procedure of imaging is performed.

The apparatus for inspecting the surface of a cylindrical body according to the present invention, which solves the above problems,
A support mechanism that supports a cylindrical body rotatably about its axis, a light source that irradiates the cylindrical body supported by the support mechanism with light, and means for moving the light source, wherein the light source emits light. an irradiation angle changing means for changing the irradiation angle of the light to the surface of the cylindrical body, a one-dimensional imaging means and a two-dimensional imaging means, and a control means,
The control means irradiates the cylindrical body with light from the light source while the cylindrical body is being rotated by the support mechanism. a first procedure for receiving light with a one-dimensional imaging means and stopping the rotation of the cylindrical body by stopping the support mechanism when a defect on the surface of the cylindrical body is detected from the image captured by the one-dimensional imaging means;
Next, with the rotation of the cylindrical body stopped, the irradiation angle of the light emitted from the light source with respect to the surface of the cylindrical body is changed to an angle different from the irradiation angle in the first procedure, moving the light source with the irradiation angle changing means, irradiating the cylindrical body with light from the light source, and receiving the reflected light of the irradiated light reflected on the surface of the cylindrical body with the two-dimensional imaging means; Control is performed so that the second procedure of imaging the position of the defect detected in the first procedure by the two-dimensional imaging means is performed.

Another aspect of the present invention for solving the above problems is an inspection apparatus for the surface of a cylindrical body,
A support mechanism that supports a cylindrical body rotatably around the axis of the cylindrical body, a first light source that irradiates the cylindrical body supported by the supporting mechanism with light, and an irradiation angle with respect to the surface of the cylindrical body , a second light source that irradiates the cylindrical body with light from an angle different from the irradiation angle of the light emitted from the first light source, a one-dimensional imaging means and a two-dimensional imaging means, and a control means. , and
The control means irradiates the cylindrical body with light from the first light source while the cylindrical body is rotated by the support mechanism, and the irradiated light is reflected by the surface of the cylindrical body. Light is received by the one-dimensional imaging means, and when a defect on the surface of the cylindrical body is detected from the image captured by the one-dimensional imaging means, the supporting mechanism is stopped to stop the rotation of the cylindrical body. and
Next, while the rotation of the cylindrical body is stopped, the cylindrical body is irradiated with light from the second light source, and the reflected light reflected by the surface of the cylindrical body is reflected by the two-dimensional light source. The light is received by the imaging means, and the position of the defect detected in the first procedure is imaged by the two-dimensional imaging means in a second procedure.

Since the cylindrical body is an object to be inspected, the cylindrical body itself is not included in the structure of the inspection apparatus in the inspection apparatus for the surface of the cylindrical body according to the present invention.

Each term in the present invention is defined as follows.
A "cylindrical body" refers to, for example, a roller used in an industrial machine or a cylindrical part before its assembly, and includes a cylindrical part with a shaft attached. Also included are solid cylindrical rollers and members thereof.

A "light source" refers to a device that generates light, such as an LED, an organic EL, a fluorescent lamp, a halogen lamp, and an HID lamp.

A "one-dimensional imaging means" is a linear array of elements that convert the brightness of light into an electric signal, and generally refers to what is called a line camera or a line scan camera.

"Two-dimensional imaging means" is an arrangement of elements that convert the brightness of light into an electrical signal on a plane, and is generally called an area camera or area scan camera, or a microscope. refers to what is called

The term “irradiation angle changing means” refers to a mechanism that movably supports a light source and can move the light source by driving means such as a motor and an actuator.

"Control means" refers to means for controlling the operation of the light source, one-dimensional imaging means, two-dimensional imaging means, irradiation angle changing means, and support mechanism, for example, a programmable logic controller (hereinafter sometimes referred to as PLC). , personal computers (hereinafter sometimes referred to as PCs), smartphones and tablet terminals, electric circuits combined with them, and image processing devices including functions equivalent to them.

"Stopping the rotation of the cylinder when a defect is detected on the surface of the cylinder" means not only the procedure of stopping the cylinder at the same time as the defect is detected, but also It also includes a procedure for rotating the cylinder by the amount of rotation and then stopping.

According to the cylindrical body surface inspection method and the cylindrical body surface inspection apparatus of the present invention, defects can be detected even if the cylindrical body surface is made of transparent or nearly transparent material.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of a first embodiment of a cylindrical body surface inspection apparatus according to the present invention, viewed from the central axis direction of a cylindrical body; It is a schematic diagram explaining an example of a support mechanism and an irradiation angle of light from a light source. It is the schematic which looked at 2nd Embodiment of the surface inspection apparatus of the cylindrical body of this invention from the center-axis direction of a cylindrical body. It is the schematic which looked at 3rd Embodiment of the test|inspection apparatus of the surface of a cylinder of this invention from the planar direction.

Hereinafter, examples of embodiments of the present invention will be described with reference to the drawings.

[First embodiment]
Please refer to FIG. FIG. 1 is a schematic view of the first embodiment of the inspection apparatus for the surface of a cylindrical body according to the present invention, viewed from the direction of the central axis of the cylindrical body. An inspection apparatus 1a (hereinafter simply referred to as "inspection apparatus 1a") of the first embodiment includes a support mechanism (not shown in FIG. A light source 5 for irradiating light, a one-dimensional imaging means 3 for receiving light reflected by the surface of the cylindrical body 2 from the light emitted by the light source 5, and an irradiation angle changing means (not shown) for changing the position of the light source 5. ), a two-dimensional imaging means 4 for receiving the light emitted by the light source 5' whose position has been changed and reflected by the surface of the cylindrical body 2, a support mechanism, a light source 5 (5'), a one-dimensional imaging means 3, A control means (not shown) for controlling the two-dimensional image means 5 and the irradiation angle changing means is provided.

As the cylindrical body 2 to be inspected by the inspection apparatus 1a, any cylindrical body can be applied, but a cylindrical body having an outer diameter of 100 mm or more and 1000 mm or less and a surface length of 0.5 m or more and 10 m or less is preferably used. Examples include paper manufacturing equipment, plastic film manufacturing equipment, metal rolling equipment, post-processing equipment such as web coating and vapor deposition, and rollers used in printing and copying equipment. In particular, if the inspection device 1a is used, fine surface defects can be detected even on a large cylinder, so that fine defects on the surface of the cylinder directly lead to product defects, such as thermoplastic resin with two rollers. It is possible to preferably detect minute surface defects of a roller used in a film-forming apparatus that performs clamping and cooling to obtain a plastic film.

First, the control means irradiates the cylindrical body 2 with light from the light source 5 while the cylindrical body 2 is being rotated by the support mechanism. The light is received by the imaging means 3, and a defect on the surface of the cylindrical body 2 is detected from the image captured by the one-dimensional imaging means 3. At the same time, the support mechanism is stopped to stop the rotation of the cylindrical body 2. A first procedure is performed. to control.

Please refer to FIG. FIG. 2 is a schematic diagram for explaining the support mechanism. The support mechanism 6 rotatably supports and rotates the cylindrical body 2 around the rotation axis of the cylindrical body 2 . The support mechanism 6 supports at least two portions of the cylindrical body 2 . The method of rotatably supporting the two parts is not particularly limited, but for example, two bearings supported by fitting the shaft to the inner ring are rotatably supported side by side, and the cylindrical body 2 is mounted on the outer ring of the bearing. , or simply fitting a bearing to the shaft of the cylindrical body 2 to support the bearing. A method for rotating the cylindrical body 2 is not particularly limited, but for example, a general motor such as an AC motor or a DC motor can be used, and a transmission mechanism may be provided as necessary. By taking an image with the one-dimensional imaging means 3 while rotating the cylindrical body 2 at a constant speed by the support mechanism 6, it is possible to take an image on a constant scale in the rotating direction Dr of the cylindrical body 2. FIG. In addition, it is possible to prevent omission of measurement due to exceeding the measurable speed of the one-dimensional imaging means 3 due to the rotation speed being too fast.

Refer to FIG. 1 again. The method of irradiating the light from the light source 5 is not particularly limited. It is preferable to irradiate so that the positional relationship does not change, because an image can be captured with a constant appearance.

The mutual positional relationship between the light source 5, the one-dimensional imaging means 3, and the surface of the cylindrical body 2 imaged by the one-dimensional imaging means 3 is appropriately determined depending on the surface material of the cylindrical body 2, the shape of the defect to be detected, the type of light source, and the like. adjusted and determined. In particular, when inspecting the cylindrical body 2 whose surface is transparent or nearly transparent, as shown in FIG. The angle θ formed between the tangential direction of the surface of the cylindrical body 2 in the part imaged by 3 and the line connecting the surface part imaged by the one-dimensional imaging means 3 and the position of the light source 5 is 0 to 30 degrees. It is preferable to arrange so that even a minute defect can be easily detected. Also, the one-dimensional imaging means 3 may be oriented in the direction of the central axis of the cylindrical body 2, or may be tilted by about 0 to 10 degrees.

As the light source 5, generally available light sources such as LEDs, organic ELs, fluorescent lamps, halogen lamps, and HID lamps can be appropriately selected and used. LEDs and organic ELs can be preferably used because the shape of the irradiation range and the color of the irradiated light can be changed according to the imaging means, the material of the cylindrical body 2, and the like.

The one-dimensional imaging means 4 is a linear array of elements that convert the brightness of light into an electric signal (hereinafter sometimes referred to as an imaging element), and is generally a line camera or a line scan camera. refers to what is called CCD, CMOS, etc. are generally used as imaging devices, and the number of elements is appropriately selected according to the required resolution and field of view. 2000 or more are preferable, and 4000 or more are more preferable. Also, it is preferable to adjust the magnification and the field of view by using a lens suitable for the required resolution and field of view.

Defects can be detected by continuously capturing images with the one-dimensional imaging means 3 while rotating the cylindrical body 2 and analyzing the obtained one-dimensional image data. Further, by arranging the obtained one-dimensional image data to obtain two-dimensional image data and analyzing the obtained two-dimensional image data, the defect can be detected. These can be realized by, for example, a commercially available image processing device or computer program, but the means is not particularly limited.

Next, the control means changes the irradiation angle of the surface of the cylindrical body 2 irradiated from the light source 5 to an angle different from the irradiation angle in the first procedure, while the rotation of the cylindrical body 2 is stopped. The light source 5 is moved to the position 5' by the irradiation angle changing means, the light source 5' irradiates the cylindrical body 2, and the reflected light reflected on the surface of the cylindrical body 2 is imaged two-dimensionally. The light is received by the means 4, and the position of the defect detected in the first procedure is imaged by the two-dimensional imaging means 4, and the second procedure is performed.

The irradiation angle is determined by the tangential direction of the surface of the cylindrical body 2 in the portion imaged by the one-dimensional imaging means 3 shown in FIG. In addition to the angle θ formed by the line connecting , the angle φ formed between the axial direction of the cylindrical body 2 and the irradiation direction of the light from the light source 5 around the normal to the imaging portion of the surface of the cylindrical body 2 shown in FIG.

The irradiation angle changing means can move the light source 5 to the position 5 ′ to change the angle at which the defect on the surface of the cylindrical body 2 is irradiated with light. Although the irradiation angle changing means is not particularly limited, a means for movably supporting the light source 5 and moving it by a linear actuator or a servomotor can be used.

The two-dimensional image pickup means 4 is an image pickup device arranged on a plane, and generally refers to what is called an area camera or an area scan camera, or what is called a microscope. CCD, CMOS, etc. are generally used for the imaging device, and the number of elements is appropriately selected according to the required resolution and field of view. 2 million or more are preferable, and 4 million or more are more preferable. Also, it is preferable to adjust the magnification and the field of view by using a lens suitable for the required resolution and field of view.

Since the two-dimensional image pickup means 4 picks up images in a state where the positional relationship between the two-dimensional image pickup means 4, the defect, and the light source 5 is fixed, the size of the defect can be easily measured from the obtained image data.

By comparing the imaging data obtained in the first procedure and the second procedure, that is, the imaging data with different light irradiation angles to the defect, it becomes easy to identify the type of the defect. For example, convex defects such as protrusions and deposits and concave defects such as scratches and dents move differently when the light irradiation angle is changed. Further, when the cylindrical body 2 is transparent or translucent, similarly, since the appearance of the shadow differs between surface defects and internal defects, it is possible to distinguish between them.

In addition, before the second procedure, a procedure of imaging using the two-dimensional imaging means 4 at the same irradiation angle of light as in the first procedure may be added, and after the second procedure, further irradiation of light may be added. It is preferable to add a procedure of imaging with the two-dimensional imaging means 4 while changing the angle once or several times and compare the obtained imaging data, because it is possible to determine the type of defect with higher accuracy.

The control means controls operations of the light source 5 , the one-dimensional imaging means 3 , the two-dimensional imaging means 4 , the irradiation angle changing means, and the support mechanism 6 . Although the control means is not particularly limited, for example, a PLC, a PC, a smart phone, a tablet terminal, an electric circuit combined with them, an image processing device including functions equivalent thereto, or the like can be used.

In the inspection apparatus 1a, the position of the light source 5 is automatically moved by the irradiation angle changing means 5, but the light source 5 may be moved manually. However, automatic control is preferable because the irradiation position by the light source 5 is more accurate.

In the inspection apparatus 1a, the support mechanism is stopped at the same time that the defect is detected in the first procedure to stop the rotation of the cylindrical body 2. The two-dimensional imaging means 4 captures an image of the position roughly corresponding to , while the light source 5' is illuminating the position, but the method is not limited to this method. After detecting the defect in the first procedure, rotate the cylindrical body 2 for a predetermined time or amount of rotation, then stop the support mechanism, and in the second procedure, the location of the defect detected by the one-dimensional image means 3, In other words, a position different from the position imaged by the one-dimensional imaging means 3 may be imaged by the two-dimensional imaging means 4 while being illuminated by the light source 5'.

[Second embodiment]
Please refer to FIG. FIG. 3 is a schematic view of the second embodiment of the cylindrical body surface inspection apparatus of the present invention, viewed from the central axis direction of the cylindrical body. The inspection apparatus 1b of the second embodiment (hereinafter simply referred to as "inspection apparatus 1b") has a first light source 51 and a first A second light source 52 is provided to irradiate light from an angle different from that of the light source of the second light source. Further, since the inspection apparatus 1b does not mechanically move the light source, the irradiation angle changing means provided in the inspection apparatus 1a may not be provided. Therefore, since the inspection apparatus 1b does not require irradiation angle changing means, it is not necessary to control the irradiation angle changing means by the control means. The inspection apparatus 1b has the same configuration as the inspection apparatus 1a except for these differences.

The second light source 52 irradiates the cylindrical body 2 with light from an angle different from the irradiation angle of the light emitted from the first light source 51 with respect to the surface of the cylindrical body 2 .

First, the control means irradiates the surface of the cylindrical body 2 with light from the first light source 51 while the cylindrical body 2 is being rotated by the support mechanism, and the irradiated light is reflected by the surface of the cylindrical body 2. Light is received by the one-dimensional imaging means 3, a defect is detected from the image picked up by the one-dimensional imaging means 3, the cylindrical body 2 is rotated by a predetermined time or amount of rotation, and then the support mechanism is stopped. Control to do the procedure.

Next, the control means turns off the first light source 51 and turns on the second light source 52 while the rotation of the cylindrical body 2 is stopped, thereby changing the irradiation angle with respect to the cylindrical body 2 so that the irradiated light is The light reflected by the surface of the cylindrical body 2 is received by the two-dimensional imaging means, and the two-dimensional imaging means 4 is controlled to perform the second procedure of imaging the defect detected in the first procedure. It should be noted that the first light source 51 may be left on as long as it does not hinder the imaging by the two-dimensional image means 4 .

Similar to the inspection by the inspection apparatus 1a, also in the inspection by the inspection apparatus 1b, by comparing the imaging data obtained in the first procedure and the second procedure, that is, the imaging data with different irradiation angles of light to the defect, , it becomes easier to identify the type of defect. A procedure for imaging with the two-dimensional imaging means 4 before turning off the first light source 1 may be added. You may add the procedure of imaging with the two-dimensional imaging means 4 for several times.

At least one second light source 52 is sufficient, but a plurality of second light sources 52 may be provided. For example, as shown in FIG. 3, the second light source 52 is a ring-shaped LED capable of split lighting, and the irradiation part is divided into four by 90 degrees, and the irradiation angle is changed by switching between them. can be used.

In the inspection apparatus 1b, after detecting a defect in the first procedure, the cylindrical body 2 is rotated by a predetermined time or amount of rotation, and then the supporting mechanism is stopped. The position of the detected defect, that is, the position different from the position imaged by the one-dimensional imaging means 3 is imaged by the two-dimensional imaging means 4 while being illuminated by the second light source 52, but it is necessary to limit this method. no. At the same time when the defect is detected in the first procedure, the support mechanism is stopped to stop the rotation of the cylindrical body 2, and in the second procedure, the position roughly coincides with the image pickup position picked up by the one-dimensional image means 3. may be imaged by the two-dimensional imaging means 4 while being irradiated by the second light source 52 .

Also, the inspection apparatus 1b has two light sources, the first light source 51 and the second light source 52, and the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 can be matched to enable split lighting. A single light source may illuminate the imaged portion. In this case, the first light source 51 is turned on in the first procedure, and the second light source 52 is turned on in the second procedure. As such a light source capable of split lighting, for example, there is a ring-shaped LED light capable of split lighting.

[Third embodiment]
Please refer to FIG. FIG. 4 is a schematic plan view of a third embodiment of the apparatus for inspecting the surface of a cylindrical body according to the present invention. An inspection apparatus 1c of the third embodiment (hereinafter simply referred to as "inspection apparatus 1c") is an embodiment in which the configuration of the inspection apparatus 1b of the second embodiment is changed.

In the inspection apparatus 1c, the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 are matched, and instead of being provided with two light sources, the first light source 51 and the second light source 52, one divided light source capable of split lighting is provided. A light source 5 that can be turned on illuminates this imaging portion. By lighting different parts of the light source 5 in the first and second procedures, the first light source 51 is turned on in the first procedure, and the second light source is turned on in the second procedure. 52 is substituted.

In the inspection apparatus 1c, the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 are matched, so in the first procedure, the support mechanism 6 is stopped at the same time as the defect is detected, and the cylindrical body 2 is inspected. stop the rotation.

Moreover, since the inspection device 1c is provided with a movement support mechanism 7 and the whole inspection device 1c is fixed to the movement support mechanism 7, the whole inspection device 1c can be moved in parallel with the central axis of the cylindrical body 2. . While rotating the cylindrical body 2, the inspection device 1c is moved parallel to the rotation axis of the cylindrical body 2 by the movement support mechanism 7, so that the inspection device 1c moves the surface of the cylindrical body 2 in the rotational direction Dr of the cylindrical body 2. It is possible to scan obliquely with the laser beam, and the entire surface of the cylindrical body 2 can be inspected smoothly. In addition, since the moving support mechanism 7 also has a mechanism that moves in conjunction with the rotation angle of the cylindrical body 2, the imaging mechanism 7 moves in a direction parallel to the rotation axis of the cylindrical body 2 while the cylindrical body 2 rotates once. By setting the distance equal to or less than the measurement range of the one-dimensional imaging means 3 in the rotation axis direction Dp of the cylindrical body 2, the entire surface of the cylindrical body 2 can be measured all over. As the movement support mechanism 7, commercially available linear guides, linear actuators, combinations of linear bearings and shafts, rack pinions, ball screws, and the like can be suitably used.

[others]
In the inspection apparatuses 1a, 1b, and 1c, the support mechanism 6 rotates the cylindrical body 2 by automatic control. Alternatively, both ends of the cylindrical body 2 may be supported by a rotatable support method such as bearings, and rotated by hand. . However, since it is possible to pick up an image at a constant scale by rotating at a constant speed, it is preferable to rotate by a driving means, and the labor required for rotation can be reduced.

Using the inspection device 1c shown in FIG. 4, the surface of a roller having an outer diameter of 300 mm, a surface length of 2 m and a surface material of transparent silicone rubber as the cylindrical body 2 was inspected. As the one-dimensional imaging means 3, a keyence line camera (XG-HL04M) was used, and as the two-dimensional imaging means 4, a digital microscope (Dino-Lite Edge AMR) manufactured by ANMO was used. A ring-shaped LED light is used as the light source 5, and when the one-dimensional imaging means 3 picks up an image, 1/4 of the circumference is lit, and the one-dimensional imaging means 3 picks up the lighted portion as the first light source 51. The angle θ between the tangential direction of the surface of the cylindrical body 2 in the portion where the image is taken and the line connecting the position of the light source 5 and the portion being imaged by the one-dimensional imaging means 3 is 10 degrees, and the surface of the cylindrical body 2 The angle φ between the axial direction of the cylindrical body 2 and the light irradiation direction of the light source 5 around the normal to the imaging unit was set to 90 degrees. When photographing with the one-dimensional imaging means 3, the rotational speed of the roller was set to 2 rpm, and the moving support mechanism 7 was set to move the cylindrical body 2 in parallel with its axial direction by 15 mm while the cylindrical body 2 rotates once. A planar image was obtained by aligning the measurement results of the one-dimensional imaging means 3 by a computer program, and a bright area in the image was determined and detected as a defect. Simultaneously with the detection, the rotation of the cylindrical body 2 and the parallel movement by the movement support mechanism 7 were stopped, and the defect was imaged using the two-dimensional imaging means 4 . At this time, the angle φ between the axial direction of the cylindrical body 2 and the irradiation direction of the light from the light source 5 around the normal to the imaging unit on the surface of the cylindrical body 2 is switched by turning on the 1/4 of the circumference of the ring-shaped LED. was changed by 90 degrees, and a total of four images were taken for one defect.

Four images are checked for each defect, and if the shadow extends inside the defect, it is a scratch or a dent. It was judged as an internal foreign matter and classified. On the other hand, the image of the one-dimensional imaging means 3 did not clearly show the characteristics of the defect, so the defect could not be determined.

Then, for confirmation, each defective portion of the silicone rubber roller was cut out and observed with a laser microscope (LEXT OLS4000) manufactured by Olympus to identify the type of defect. As a result, correct determination was made for 14 out of 15 detected defects.

The present invention is not limited to cylindrical body surface shape measuring devices for measuring industrial rollers such as film-forming rollers, but is also applicable to measuring devices for measuring rollers used in consumer devices such as printers. However, the scope of application is not limited to these.

1a, 1b, 1c cylinder surface inspection apparatus 2 cylinder 3 one-dimensional imaging means 4 two-dimensional imaging means 5, 5' light source 51 first light source 52 second light source 6 support mechanism 7 movement support mechanism Dr cylinder rotation Direction Dp Direction of central axis of cylinder θ Angle between tangent to cylinder and direction of light irradiation φ Angle between axis of cylinder and direction of light irradiation

Claims (3)

A method of inspecting a surface of a cylinder, comprising:
With the cylinder rotated,
irradiating the cylindrical body with light;
receiving reflected light of the irradiated light reflected on the surface of the cylindrical body by a one-dimensional imaging means;
a first step of stopping the rotation of the cylindrical body when a defect on the surface of the cylindrical body is detected from the image captured by the one-dimensional imaging means;
Next, with the cylindrical body stopped,
irradiating the cylindrical body with light from an angle where the irradiation angle with respect to the surface of the cylindrical body is different from the irradiation angle of the light irradiated on the surface of the cylindrical body in the first step;
receiving reflected light of the irradiated light reflected on the surface of the cylindrical body by a two-dimensional imaging means;
a second step of imaging the position of the defect detected in the first step with the two-dimensional imaging means;
A method for inspecting the surface of a cylindrical body. An apparatus for inspecting the surface of a cylinder, comprising:
a support mechanism that supports the cylindrical body so as to be rotatable around the axis of the cylindrical body;
a light source that irradiates the cylindrical body supported by the support mechanism with light;
means for moving the light source, the irradiation angle changing means for changing the irradiation angle of the light emitted from the light source with respect to the surface of the cylindrical body;
a one-dimensional imaging means and a two-dimensional imaging means;
a control means;
The control means is
While the cylindrical body is rotated by the support mechanism, the light source irradiates the cylindrical body with light, and the reflected light reflected by the surface of the cylindrical body is captured by the one-dimensional imaging means. a first step of stopping the rotation of the cylindrical body by stopping the support mechanism when a defect on the surface of the cylindrical body is detected from the image captured by the one-dimensional imaging means;
Next, while the rotation of the cylindrical body is stopped, the irradiation angle of the light emitted from the light source with respect to the surface of the cylindrical body is changed to an angle different from the irradiation angle in the first step. moving the light source by the irradiation angle changing means, irradiating the cylindrical body with light from the light source, and receiving the reflected light of the irradiated light reflected on the surface of the cylindrical body by the two-dimensional imaging means; a second procedure of imaging the position of the defect detected in the first procedure with the two-dimensional imaging means;
control to do
Cylinder surface inspection equipment. An apparatus for inspecting the surface of a cylinder, comprising:
a support mechanism that supports the cylindrical body so as to be rotatable around the axis of the cylindrical body;
a first light source that irradiates the cylindrical body supported by the support mechanism with light;
a second light source that irradiates the cylindrical body with light from an angle different from the irradiation angle of the light emitted from the first light source with respect to the surface of the cylindrical body;
a one-dimensional imaging means and a two-dimensional imaging means;
a control means;
The control means is
In a state where the cylindrical body is rotated by the support mechanism, the cylindrical body is irradiated with light from the first light source, and the reflected light reflected by the surface of the cylindrical body is converted into the one-dimensional light. a first procedure of stopping the rotation of the cylindrical body by stopping the support mechanism when a defect on the surface of the cylindrical body is detected from the image captured by the one-dimensional imaging means;
Next, while the rotation of the cylindrical body is stopped, the cylindrical body is irradiated with light from the second light source, and the reflected light reflected by the surface of the cylindrical body is reflected by the two-dimensional light source. a second procedure of receiving light with an imaging means and imaging the position of the defect detected in the first procedure with the two-dimensional imaging means;
control to do
Cylinder surface inspection equipment.

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