JP7697354B2 - Method and apparatus for inspecting the surface of a cylindrical body - Google Patents

Description

The present invention relates to a method and apparatus for detecting defects on a cylindrical surface.

In the manufacturing process of cylindrical objects such as rubber rollers, defects such as scratches and dents can occur on the surface, which is a problem. The required surface properties vary depending on the application of the cylindrical object, but for applications such as rollers for film production where scratches and dents are unacceptable, an inspection method and inspection device that can inspect the surface with high precision is required.

Conventionally, when inspecting for such defects, in addition to visual inspection by human eyes, the surface of the cylinder has been detected in some way to determine whether or not there is a defect. For example, there is a technology in which a distance sensor is used to measure the surface of a cylinder, as described in Patent Document 1, and a technology in which light leaking from a gap between a cylinder and two measuring cylinders is detected to confirm the presence or absence of surface irregularities, as described in Patent Document 2.

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

However, the technologies of Patent Documents 1 and 2 have the following problems. Patent Document 1 uses a distance meter that uses laser light or the like, so if the material of the cylinder surface is transparent or nearly so, light passes through and detects information about the inside of the cylinder surface, such as reflected light from internal foreign objects, and the distance to the surface cannot be measured accurately, resulting in a large number of false positives. Patent Document 2 also detects light leakage from defective areas, but if the material of the cylinder surface is transparent rubber or the like, light will leak from areas other than defective areas of the cylinder, making it impossible to detect unevenness.

The present invention solves the problems of the conventional technology by providing a cylinder surface inspection device and a cylinder inspection method that can detect minute defects even when the cylinder surface is made of a transparent or nearly transparent material, and can also identify the type of defect detected.

The method for inspecting a surface of a cylindrical body according to the present invention, which solves the above problems, is a method for inspecting a surface of a cylindrical body, comprising the steps of:
a first step of irradiating the cylinder with light while rotating the cylinder, receiving light reflected from a surface of the cylinder by a one-dimensional imaging means, and stopping the rotation of the cylinder when a defect on the surface of the cylinder is detected from an image captured by the one-dimensional imaging means;
Next, a second procedure is performed in which, while the cylinder is stopped, light is irradiated onto the cylinder from an angle relative to the surface of the cylinder that is different from the angle of irradiation of the light irradiated onto the surface of the cylinder in the first procedure, the reflected light of the irradiated light reflected on the surface of the cylinder is received by a two-dimensional imaging means, and the position of the defect detected in the first procedure is imaged by the two-dimensional imaging means.

The cylindrical body surface inspection device of the present invention, which solves the above problems, is
The imaging device includes a support mechanism that supports a cylindrical body rotatably around an axis, a light source that irradiates light onto the cylindrical body supported by the support mechanism, a means for moving the light source, the light irradiation angle changing means being capable of changing the irradiation angle of the light irradiated from the light source with respect to the surface of the cylindrical body, a one-dimensional imaging means, a two-dimensional imaging means, and a control means,
a first step in which the control means, while rotating the cylinder by the support mechanism, irradiates the cylinder with light from the light source, receives light reflected from the surface of the cylinder by the one-dimensional imaging means, and, when a defect on the surface of the cylinder is detected from an image captured by the one-dimensional imaging means, stops the support mechanism to stop the rotation of the cylinder;
Next, while the rotation of the cylinder is stopped, the light source is moved by the irradiation angle changing means so that the irradiation angle of the light irradiated from the light source to the surface of the cylinder is different from the irradiation angle in the first procedure, light is irradiated from the light source to the cylinder, the reflected light of the irradiated light reflected on the surface of the cylinder is received by the two-dimensional imaging means, and a second procedure is performed in which the position of the defect detected in the first procedure is imaged by the two-dimensional imaging means.

Another embodiment of the present invention for solving the above problems is an inspection device for a cylindrical body surface,
The present invention comprises a support mechanism for supporting a cylindrical body rotatably around an axis of the cylindrical body, a first light source for irradiating light onto the cylindrical body supported by the support mechanism, a second light source for irradiating light onto the cylindrical body from an angle with respect to a surface of the cylindrical body that is different from an angle of irradiation of light irradiated from the first light source, one-dimensional imaging means, two-dimensional imaging means, and control means,
a first step in which the control means, while rotating the cylinder by the support mechanism, irradiates the cylinder with light from the first light source, receives light reflected from the surface of the cylinder by the one-dimensional imaging means, and, when a defect on the surface of the cylinder is detected from an image captured by the one-dimensional imaging means, stops the support mechanism to stop the rotation of the cylinder;
Next, while the rotation of the cylinder is stopped, light is irradiated onto the cylinder from the second light source, the irradiated light is reflected off the surface of the cylinder and received by the two-dimensional imaging means, and a second procedure is performed in which the position of the defect detected in the first procedure is imaged by the two-dimensional imaging means.

In addition, since the cylinder is the object to be inspected, in the inspection device for the surface of a cylinder of the present invention, the cylinder itself is not included in the configuration of the inspection device.

Each term in the present invention is defined as follows.
The term "cylinder" refers to, for example, rollers used in industrial machinery and cylindrical parts before assembly, including cylindrical parts with shafts attached. It also includes solid cylindrical rollers and their components.

"Light source" refers to a device that generates light, such as an LED, organic electroluminescence (EL), fluorescent lamp, halogen lamp, or HID lamp.

A "one-dimensional imaging means" is a device that has elements arranged in a straight line that convert the brightness of light into an electrical signal, and is generally referred to as a line camera or line scan camera.

"Two-dimensional imaging means" refers to a plane array of elements that convert the brightness of light into electrical signals, and generally refers to what are called area cameras, area scan cameras, or microscopes.

"Illumination angle change means" refers to a mechanism that supports the light source so that it can be moved, and that can move the light source using a driving means such as a motor or 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, such as a programmable logic controller (hereinafter sometimes referred to as a PLC), a personal computer (hereinafter sometimes referred to as a PC), a smartphone, a tablet terminal, and an image processing device that includes an electric circuit combined with these or a function equivalent thereto.

"Stopping the rotation of the cylinder when a defect is detected on the surface of the cylinder" includes not only the procedure of stopping the cylinder at the same time as detecting the defect, but also the procedure of rotating the cylinder for a specified time or amount of rotations after detecting the defect and then stopping it.

The cylindrical body surface inspection method and cylindrical body surface inspection device of the present invention can detect defects even if the cylindrical body surface is made of a transparent or nearly transparent material.

1 is a schematic diagram of a first embodiment of an inspection device for a surface of a cylindrical body according to the present invention, viewed from the central axial direction of the cylindrical body. 5A to 5C are schematic diagrams illustrating an example of a support mechanism and an illumination angle of light from a light source. 1 is a schematic diagram of a second embodiment of the surface inspection device for a cylindrical body of the present invention, viewed from the central axial direction of the cylindrical body. FIG. 11 is a schematic diagram showing a third embodiment of the cylindrical body surface inspection device of the present invention as viewed from a plan view. FIG.

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

[First embodiment]
Please refer to Fig. 1. Fig. 1 is a schematic diagram of a first embodiment of an inspection device for a cylindrical body surface according to the present invention, viewed from the central axis direction of the cylindrical body. The inspection device 1a of the first embodiment (hereinafter, simply referred to as "inspection device 1a") includes a support mechanism (not shown in Fig. 1) that supports a cylindrical body 2 rotatably around an axis, a light source 5 that irradiates light onto the cylindrical body 2, a one-dimensional imaging means 3 that receives light reflected from the surface of the cylindrical body 2 by the light irradiated by the light source 5, an irradiation angle changing means (not shown) that changes the position of the light source 5, a two-dimensional imaging means 4 that receives light reflected from the surface of the cylindrical body 2 by the light irradiated by the light source 5' whose position has been changed, and a control means (not shown) that controls the support mechanism, the light source 5 (5'), the one-dimensional image means 3, the two-dimensional image means 5, and the irradiation angle changing means.

The inspection device 1a can be used to inspect any cylinder 2, but is preferably used for cylinders with an outer diameter of 100 mm to 1000 mm and a face length of 0.5 m to 10 m. Examples include papermaking equipment, plastic film production equipment, metal rolling equipment, post-processing equipment such as web coating and deposition, and rollers used in printing and copying equipment. In particular, the inspection device 1a can detect minute surface defects even in large cylinders, making it suitable for applications in which minute defects on the surface of a cylinder directly lead to product defects, such as minute surface defects on rollers used in film production equipment that clamps and cools thermoplastic resin between two rollers to obtain a plastic film.

The control means controls the first procedure to perform: first, while rotating the cylinder 2 with the support mechanism, light is irradiated from the light source 5 onto the cylinder 2, the irradiated light is reflected by the surface of the cylinder 2 and received by the one-dimensional imaging means 3, and defects on the surface of the cylinder 2 are detected from the image captured by the one-dimensional imaging means 3, and at the same time, the support mechanism is stopped to stop the rotation of the cylinder 2.

Refer to FIG. 2. 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 points of the cylindrical body 2. There is no particular limitation on the method of rotatably supporting the two points, but for example, a method in which two bearings are supported by fitting a shaft into the inner ring of the bearing, and the cylindrical body 2 is placed on the outer ring of the bearing, and a method in which a bearing is simply fitted into the shaft of the cylindrical body 2 and supported by the bearing, may be used. There is no particular limitation on the method of rotating the cylindrical body 2, but for example, a general motor such as an AC motor or a DC motor may be used, and a speed change mechanism may be provided as necessary. By rotating the cylindrical body 2 at a constant speed by the support mechanism 6 and imaging it with the one-dimensional imaging means 3, it is possible to image the cylindrical body 2 at a constant scale with respect to the rotation direction Dr. In addition, it is possible to prevent measurement omissions due to the rotation speed being too fast and exceeding the measurable speed of the one-dimensional imaging means 3.

Refer back to Figure 1. There are no particular limitations on the method of irradiating light from the light source 5, but it is preferable that the light is irradiated in such a way that the relative positions of the light source 5, the one-dimensional imaging means 3, and the surface of the cylinder 2 imaged by the one-dimensional imaging means 3 do not change during imaging by the one-dimensional imaging means 3, since this allows imaging to be performed with a consistent appearance.

The relative positions of the light source 5, the one-dimensional imaging means 3, and the surface of the cylinder 2 imaged by the one-dimensional imaging means 3 are appropriately adjusted and determined depending on the surface material of the cylinder 2, the shape of the defect to be detected, the type of light source, etc. In particular, when inspecting a cylinder 2 whose surface is made of a transparent or nearly transparent material, it is preferable to image the one-dimensional imaging means 3 toward the central axis direction of the cylinder 2 as shown in FIG. 1, and to arrange the one-dimensional imaging means 3 so that the angle θ between the tangent direction of the surface of the cylinder 2 in the part imaged by the one-dimensional imaging means 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, since this makes it easier to detect even minute defects. In addition, the one-dimensional imaging means 3 may be oriented toward the central axis direction of the cylinder 2, or may be tilted by about 0 to 10 degrees.

The light source 5 can be selected from commonly available light sources such as LEDs, organic electroluminescence (EL), fluorescent lamps, halogen lamps, and HID lamps. LEDs and organic electroluminescence (EL) are preferably used because the shape of the illumination range and the color of the irradiated light can be changed to match the imaging means and the material of the cylinder 2.

The one-dimensional imaging means 4 is a linear arrangement of elements (hereinafter sometimes referred to as imaging elements) that convert the brightness and darkness of light into electrical signals, and generally refers to what is called a line camera or line scan camera. CCDs, CMOSs, etc. are generally used as imaging elements, and the number of elements is appropriately selected depending on the required resolution and field of view. For example, if it is desired to detect defects of 100 μm or less in size with a field of view of 10 mm or more, the number of elements is preferably 2000 or more, and more preferably 4000 or more. It is also preferable to adjust the magnification and field of view using lenses suitable for the required resolution and field of view.

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

The control means then controls the second procedure to stop the rotation of the cylinder 2, move the light source 5 to the position indicated by the symbol 5' using the irradiation angle changing means so that the irradiation angle of the light emitted from the light source 5 on the surface of the cylinder 2 is different from the irradiation angle in the first procedure, irradiate light from the light source 5' onto the cylinder 2, receive the reflected light reflected by the surface of the cylinder 2 with the two-dimensional imaging means 4, and image the position of the defect detected in the first procedure with the two-dimensional imaging means 4.

The above-mentioned irradiation angle includes the angle θ between the tangent direction of the surface of the cylinder 2 in the portion imaged by the one-dimensional imaging means 3 shown in FIG. 1 and the line connecting the surface portion imaged by the one-dimensional imaging means 3 and the position of the light source 5, as well as the angle φ between the axial direction of the cylinder 2 around the normal to the imaging portion of the surface of the cylinder 2 shown in FIG. 2 and the irradiation direction of the light of the light source 5.

The irradiation angle changing means can change the angle at which light is irradiated onto defects on the surface of the cylinder 2 by moving the light source 5 to the position indicated by the symbol 5'. The irradiation angle changing means is not particularly limited, but can be one that supports the light source 5 in a movably manner and moves it with a linear actuator or servo motor.

The two-dimensional imaging means 4 is an arrangement of imaging elements on a plane, and generally refers to what is called an area camera or area scan camera, or what is called a microscope. The imaging elements generally used are CCD or CMOS, and the number of elements is appropriately selected depending on the required resolution and field of view. For example, if it is desired to detect defects of 100 μm or less in size with a field of view of 10 mm or more, the number of elements is preferably 2 million or more, and more preferably 4 million or more. It is also preferable to adjust the magnification and field of view using lenses suitable for the required resolution and field of view.

Since the two-dimensional imaging means 4 captures images while the positional relationship between the two-dimensional imaging means 4, the defect, and the light source 5 is fixed, the size of the defect can be easily measured from the obtained imaging data.

By comparing the imaging data obtained in the first and second steps, i.e. imaging data obtained at different angles of light irradiation on the defect, it becomes easy to identify the type of defect. For example, the way in which the shadow moves when the light irradiation angle is changed differs between convex defects such as protrusions or deposits and concave defects such as scratches and dents. Similarly, if the cylinder 2 is transparent or translucent, the shadows of surface defects and internal defects will look different, making it possible to distinguish between them.

Also, before the second step, a step of capturing images using the two-dimensional imaging means 4 at the same light irradiation angle as in the first step may be added, or after the second step, a step of capturing images using the two-dimensional imaging means 4 while changing the light irradiation angle once or multiple times may be added, and the resulting image data may be compared, which is preferable since it allows for even more accurate identification of the type of defect.

The control means controls the operation 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. The control means is not particularly limited, but can be, for example, a PLC, a PC, a smartphone, a tablet terminal, an electric circuit combined with these, or an image processing device including equivalent functions.

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

In the inspection device 1a, in the first step, the support mechanism is stopped at the same time as the defect is detected, and the rotation of the cylinder 2 is stopped, and in the second step, a position roughly corresponding to the imaging position imaged by the one-dimensional imaging means 3 is imaged by the two-dimensional imaging means 4 while irradiating it with the light source 5', but this method does not have to be limited to this. In the first step, after the defect is detected, the cylinder 2 may be rotated for a predetermined time or amount of rotation, and then the support mechanism may be stopped, and in the second step, the location of the defect detected by the one-dimensional imaging means 3, i.e., 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 irradiating it with the light source 5'.

Second Embodiment
Please refer to FIG. 3. FIG. 3 is a schematic diagram of a second embodiment of the inspection device for a cylindrical body surface of the present invention, viewed from the central axis direction of the cylindrical body. The inspection device 1b of the second embodiment (hereinafter, simply referred to as "inspection device 1b") is provided with a first light source 51 and a second light source 52 that irradiates light from an angle different from that of the first light source, instead of the light source 5 provided in the inspection device 1a of the first embodiment. In addition, since the inspection device 1b does not mechanically move the light source, it does not need to be provided with the irradiation angle changing means provided in the inspection device 1a. Therefore, since the inspection device 1b does not need the irradiation angle changing means, it is not necessary to control the irradiation angle changing means with the control means. The inspection device 1b has the same configuration as the inspection device 1a except for these differences.

The second light source 52 irradiates the cylinder 2 with light from an angle that is different from the angle of irradiation of the light irradiated from the first light source 51 with respect to the surface of the cylinder 2.

The control means controls the first procedure to perform, while rotating the cylinder 2 with the support mechanism, irradiating the surface of the cylinder 2 with light from the first light source 51, receiving the light reflected by the surface of the cylinder 2 with the one-dimensional image means 3, detecting a defect from the image captured by the one-dimensional imaging means 3, and then rotating the cylinder 2 for a predetermined time or amount of rotation before stopping the support mechanism.

The control means then controls to perform a second procedure in which, with the rotation of the cylinder 2 stopped, the first light source 51 is turned off and the second light source 52 is turned on to change the irradiation angle with respect to the cylinder 2, the irradiated light is reflected by the surface of the cylinder 2, and the reflected light is received by the two-dimensional image means, and the defective portion detected in the first procedure is imaged by the two-dimensional imaging means 4. Note that the first light source 51 may remain on as long as it does not interfere with imaging by the two-dimensional imaging means 4.

As with the inspection by the inspection device 1a, in the inspection by the inspection device 1b, the type of defect can be easily identified by comparing the imaging data obtained in the first and second procedures, i.e., imaging data with different angles of light irradiation on the defect. An additional procedure may be added in which imaging is performed by the two-dimensional imaging means 4 before the first light source 1 is turned off, or a procedure may be added in which multiple second light sources 52 are provided and imaging is performed by the two-dimensional imaging means 4 multiple times for each irradiation of light from the second light source.

At least one second light source 52 is sufficient, but multiple light sources may be provided. For example, as shown in FIG. 3, the second light source 52 may be a ring-shaped LED that can be turned on and off in a divided manner, with the irradiation area divided into four parts at 90 degrees each, and the irradiation angle can be changed by switching between the four parts.

In the inspection device 1b, after detecting a defect in the first step, the cylinder 2 is rotated for a predetermined time or amount of rotation and then the support mechanism is stopped, and in the second step, the location of the defect detected by the one-dimensional imaging means 3, i.e., a position different from the position imaged by the one-dimensional imaging means 3, is imaged by the two-dimensional imaging means 4 while irradiating it with the second light source 52, but this method is not limited to this. At the same time as detecting the defect in the first step, the support mechanism is stopped to stop the rotation of the cylinder 2, and in the second step, a position roughly corresponding to the imaging position imaged by the one-dimensional imaging means 3 may be imaged by the two-dimensional imaging means 4 while irradiating it with the second light source 52.

In addition, the inspection device 1b is equipped with two light sources, the first light source 51 and the second light source 52, but the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 may be aligned and illuminated with one light source that can be turned on in separate steps. In this case, the portion that is turned on in the first procedure is the first light source 51, and the portion that is turned on in the second procedure is the second light source 52. An example of such a light source that can be turned on in separate steps is a ring-shaped LED light that can be turned on in separate steps.

[Third embodiment]
Please refer to Fig. 4. Fig. 4 is a schematic diagram of a third embodiment of the inspection device for a cylindrical body surface of the present invention, as viewed from a plan direction. The inspection device 1c of the third embodiment (hereinafter, simply referred to as "inspection device 1c") is an embodiment in which the configuration of the inspection device 1b of the second embodiment is changed.

In the inspection device 1c, the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 are aligned, and instead of having two light sources, a first light source 51 and a second light source 52, this imaging portion is irradiated with a single light source 5 that can be turned on separately. By turning on different parts of the light source 5 in the first and second procedures, the first light source 51 is used in the parts that are turned on in the first procedure, and the second light source 52 is used in the parts that are turned on in the second procedure.

In the inspection device 1c, the imaging portions of the one-dimensional imaging means 3 and the two-dimensional imaging means 4 are aligned, so in the first step, the support mechanism 6 is stopped at the same time as the defect is detected, thereby stopping the rotation of the cylinder 2.

The inspection device 1c is also provided with a moving support mechanism 7, and the entire inspection device 1c is fixed to the moving support mechanism 7, so that the entire inspection device 1c can be moved parallel to the central axis of the cylinder 2. By moving the inspection device 1c parallel to the rotation axis of the cylinder 2 by the moving support mechanism 7 while rotating the cylinder 2, the inspection device 1c can scan the surface of the cylinder 2 diagonally with respect to the rotation direction Dr of the cylinder 2, and the entire surface of the cylinder 2 can be smoothly inspected. The moving support mechanism 7 also has a mechanism for moving in conjunction with the rotation angle of the cylinder 2, so that the imaging mechanism 7 advances in a direction parallel to the rotation axis of the cylinder 2 by a distance equal to or less than the measurement range of the rotation axis direction Dp of the cylinder 2 of the one-dimensional imaging means 3 during one rotation of the cylinder 2, so that the entire surface of the cylinder 2 can be thoroughly measured. As the moving support mechanism 7, a commercially available linear guide, linear actuator, a combination of a linear bearing and a shaft, a rack and pinion, a ball screw, etc. can be suitably used.

[others]
In the inspection devices 1a, 1b, and 1c, the support mechanism 6 rotates the cylinder 2 under automatic control, but both ends of the cylinder 2 may be supported by a rotatable support method such as bearings and rotated manually. However, it is preferable to rotate the cylinder by a driving means because rotating the cylinder at a constant speed makes it possible to capture an image at a constant scale, and the labor required for rotation can also be reduced.

Using the inspection device 1c shown in FIG. 4, a roller having an outer diameter of 300 mm, a face length of 2 m, and a surface material of transparent silicone rubber was inspected as the cylinder 2. A Keyence line camera (XG-HL04M) was used as the one-dimensional imaging means 3, and an ANMO digital microscope (Dino-Lite Edge AMR) was used as the two-dimensional imaging means 4. A ring-shaped LED light was used as the light source 5, and when the one-dimensional imaging means 3 took an image, 1/4 of the circumference was lit, and the lit part was used as the first light source 51. The angle θ between the tangent direction of the surface of the cylinder 2 in the part imaged by the one-dimensional imaging means 3 and the line connecting the part imaged by the one-dimensional imaging means 3 and the position of the light source 5 was 10 degrees, and the angle φ between the axial direction of the cylinder 2 around the normal line of the imaging part of the surface of the cylinder 2 and the irradiation direction of the light of the light source 5 was 90 degrees. When photographing with the one-dimensional imaging means 3, the roller rotation speed was set to 2 rpm, and the moving support mechanism 7 was set to move 15 mm parallel to the axial direction of the cylinder 2 per one rotation of the cylinder 2. The measurement results of the one-dimensional imaging means 3 were aligned by a computer program to create a planar image, and bright areas in the image were determined to be defects and detected. At the same time as the detection, the rotation of the cylinder 2 and the parallel movement by the moving support mechanism 7 were stopped, and the defect was imaged using the two-dimensional imaging means 4. At this time, the ring-shaped LED was switched on and off at ¼ of the circumference, and the angle φ between the axial direction of the cylinder 2 around the normal line at the imaging part on the surface of the cylinder 2 and the irradiation direction of the light of the light source 5 was changed by 90 degrees, and a total of four images were taken for one defect.

Four images were checked for each defect, and defects with a shadow extending inside the defect were determined to be scratches or dents, defects with a shadow extending outside the defect were determined to be protrusions or foreign objects attached, and defects with barely visible shadows were determined to be internal foreign objects. However, the characteristics of the defect were not clear from the images taken by the one-dimensional imaging means 3, and it was not possible to determine the defect.

Next, to confirm the defect, each defective part of the silicone rubber roller was cut out and observed with an Olympus laser microscope (LEXT OLS4000) to identify the type of defect. As a result, the correct judgment was made for 14 out of 15 defects detected.

The present invention is not limited to cylindrical surface shape measuring devices that measure industrial rollers such as film production rollers, but can also be applied to measuring devices that measure rollers used in consumer devices such as printers, but the scope of application is not limited to these.

Reference Signs 1a, 1b, 1c Cylinder surface inspection device 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 Cylinder central axis direction θ Angle φ between tangent of cylinder and light irradiation direction Angle between axis of cylinder and light irradiation direction

Claims (3)

1. A method for inspecting a surface of a cylindrical body, comprising the steps of:
With the cylinder rotating,
Irradiating the cylindrical body with light;
The irradiated light is reflected on the surface of the cylindrical body and the reflected light is received 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 an image captured by the one-dimensional imaging means;
Next, with the cylindrical body stopped,
Irradiating the cylinder with light from an angle that is different from the angle of irradiation of the light irradiated onto the surface of the cylinder in the first step;
The irradiated light is reflected on the surface of the cylindrical body, and the reflected light is received by a two-dimensional imaging means;
a second step of imaging the position of the defect detected in the first step by the two-dimensional imaging means;
A method for inspecting a cylindrical body surface. 1. An apparatus for inspecting a surface of a cylindrical body, comprising:
a support mechanism that supports the cylindrical body so as to be rotatable around an axis of the cylindrical body;
a light source that irradiates light onto the cylindrical body supported by the support mechanism;
an illumination angle changing means for moving the light source and for changing an illumination angle of the light emitted from the light source with respect to the surface of the cylindrical body;
One-dimensional imaging means and two-dimensional imaging means;
A control means,
The control means
a first step of irradiating light from the light source onto the cylinder while rotating the cylinder with the support mechanism, receiving light reflected by the surface of the cylinder from the one-dimensional imaging means, and stopping the support mechanism to stop the rotation of the cylinder when a defect on the surface of the cylinder is detected from an image captured by the one-dimensional imaging means;
a second step of moving the light source with the irradiation angle changing means while stopping the rotation of the cylinder so that the irradiation angle of the light irradiated from the light source with respect to the surface of the cylinder becomes an angle different from the irradiation angle in the first step, irradiating the cylinder with light from the light source, receiving the reflected light of the irradiated light reflected on the surface of the cylinder with the two-dimensional imaging means, and imaging the position of the defect detected in the first step with the two-dimensional imaging means;
3. Control the device to perform the following steps:
Cylindrical surface inspection device. 1. An apparatus for inspecting a surface of a cylindrical body, comprising:
a support mechanism that supports the cylindrical body so as to be rotatable around an axis of the cylindrical body;
a first light source that irradiates light onto the cylindrical body supported by the support mechanism;
a second light source that irradiates the cylinder with light from an angle that is different from an irradiation angle of the light irradiated from the first light source with respect to the surface of the cylinder;
One-dimensional imaging means and two-dimensional imaging means;
A control means,
The control means
a first step of irradiating light from the first light source onto the cylinder while rotating the cylinder with the support mechanism, receiving light reflected by the surface of the cylinder with the one-dimensional imaging means, and stopping the support mechanism to stop the rotation of the cylinder when a defect on the surface of the cylinder is detected from an image captured by the one-dimensional imaging means;
a second step of irradiating the cylinder with light from the second light source while the rotation of the cylinder is stopped, receiving the light reflected by the surface of the cylinder with the two-dimensional imaging means, and imaging the positions of the defects detected in the first step with the two-dimensional imaging means;
3. Control the device to perform the following steps:
Cylindrical surface inspection device.

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