JP2001165868A - Inspection device for and inspection method of cylindrical surface - Google Patents

Abstract

PROBLEM TO BE SOLVED: To accurately inspect an existence of a defect on a peripheral surface of an object to be inspected even in the case where the object to be inspected is displaced without causing a large size of device and a complexity of processing. SOLUTION: A half mirror 2 is disposed such that an inclination angle of 45 deg. is imparted to an optical axis of an illumination light in a direction parallel to a tangent direction at an illumination position on a peripheral surface of an object 4 to be inspected and an optical axis of a normal reflection light in a normal direction at the illumination position. After an illumination light irradiated from a halogen lamp 3 is reflected at the half mirror 2, it is incident to the peripheral surface of the object 4 to be inspected in the normal direction. The normal reflection light of the illumination light at the peripheral surface of the object 4 to be inspected is passed through the half mirror 2 and is received by a light sensor 1. An incident angle and an emission angle of the illumination light at the illumination position on the peripheral surface of the object 4 to be inspected are 0. A reflection direction of the reflection light from the peripheral surface of the object 4 to be inspected is not largely varied even if the object 4 to be inspected is displaced by a variation of radius and a rotation disperse. The reflection light at the near state to the normal reflection light on the peripheral surface of the object 4 to be inspected is certainly received by the light sensor 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cylindrical surface inspection apparatus and an inspection method for inspecting a peripheral surface of a cylindrical body such as a photosensitive drum for use in an image forming apparatus for forming an image by an electrophotographic system. .

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus which forms an electrostatic latent image based on image light on the surface of a photosensitive drum and visualizes the electrostatic latent image into a toner image, a peripheral portion of the photosensitive drum is used. Defects such as irregularities on the surface greatly affect the image formation state. Such a defective processing operation due to a defect generated on the peripheral surface is a problem generally occurring not only in the photosensitive drum of the image forming apparatus but also in a member having a cylindrical shape.

Therefore, Japanese Patent Application Laid-Open Nos. Hei 3-206949 and Hei 7-239304 disclose optically detecting defects such as scratches and unevenness existing on the peripheral surface of an inspection object having a cylindrical shape such as a photosensitive drum. A configuration adapted to detect is disclosed. In these configurations, as shown in FIG. 4, the illumination device 13 irradiates the peripheral surface of the inspection target 14 with illumination light, which is slit light, while rotating the inspection target 14 at a predetermined speed. The light receiving device 11 receives the scattered light and the specularly reflected light of the illumination light on the surface, thereby inspecting the entire surface of the inspection object 14 for defects.

[0004]

However, in the configuration disclosed in Japanese Patent Application Laid-Open No. 7-239304, FIG.
As shown in (A), the illumination light of the illumination device 13 is obliquely applied to the peripheral surface of the inspection target 14 from a direction other than the normal direction (oblique illumination), and scattered light or positive light on the peripheral surface of the inspection target 14 is emitted. The reflected light is received by the light receiving device 11, and the presence or absence of a defect on the peripheral surface of the inspection target 14 is detected by a change in the light receiving state of the light receiving device 11, but a superficial pattern formed on the surface of the inspection target In order to inspect the light, it is necessary to receive the specular reflection light on the peripheral surface of the inspection object by the light receiving device 11. Must be on-axis. For this reason, as shown in FIG. 5B, when displacement x and y are generated in the inspection object 14 due to a change in radius or rotation unevenness in the inspection object 14, x is inspected in a direction perpendicular to the incident direction of the illumination light. The displacement of the object 14, y is the displacement of the inspection object 14 in a direction parallel to the incident direction of the illumination light, θ
Is the incident angle of the illumination light, and R is the radius of the object 14 to be inspected. On the optical axis of the specularly reflected light, dα / dx = 1 / (R · cos θ)... There is a problem that the reflected light on the peripheral surface of the object 14 cannot be received by the light receiving device 11 and the inspection performance is reduced. In addition, for the same reason, there is a problem that it is not possible to inspect the presence or absence of a defect on a peripheral surface of an inspection object whose radius changes.

On the other hand, in the configuration disclosed in Japanese Patent Application Laid-Open No. 3-206949, an image of the peripheral surface of the inspection target is read using an area sensor. An optical member such as a lens is required to correct the distortion, and there has been a problem that the size of the apparatus is increased and the cost is increased. In addition, when reading an image of a peripheral surface of a cylindrical inspection target using an area sensor, there is a problem in that the process of joining the read images to form an image for the entire circumference becomes complicated.

SUMMARY OF THE INVENTION An object of the present invention is to provide a cylindrical surface inspection apparatus capable of accurately inspecting a peripheral surface of an inspection object for a defect even when the inspection object is displaced, without increasing the size of the apparatus and complicating the processing. Is to provide.

[0007]

The present invention has the following arrangement as means for solving the above-mentioned problems.

(1) Illumination means for illuminating the peripheral surface of a cylindrical inspection object with illumination light, and light receiving means for receiving reflected light of the illumination light emitted from the illumination means on the peripheral surface of the inspection object. In the cylindrical surface inspection apparatus, the illuminating means irradiates the illumination light in a normal direction to a peripheral surface of the inspection target via a half mirror, and the light receiving means reflects the illumination light in a normal direction from the peripheral surface of the inspection target. The reflected light is received via a half mirror.

In this configuration, the peripheral surface of the inspection object is irradiated with the illumination light in the normal direction, and the light reflected from the peripheral surface of the inspection object in the normal direction is received by the light receiving means. Therefore, dα / d representing the change amount α of the reflection angle, where x is the displacement in the direction perpendicular to the normal direction of the inspection object
θ at x = 1 / (R · cos θ) becomes “0”,
The value of α becomes minimum from cos0 ° = 1. Further, the reflection angle of the light reflected in the normal direction on the peripheral surface of the inspection target does not change depending on the displacement y in the normal direction of the inspection target. For this reason, when an error or rotation unevenness from a perfect circle of the inspection object occurs, and even when the radius of the inspection object changes, regular reflection light in a state close to regular reflection light is reliably received by the light receiving unit, The presence or absence of a defect on the peripheral surface of the inspection target is always accurately inspected. Further, since a single half mirror is arranged in the optical path of the illumination light and the reflected light, the configuration of the device does not become significantly complicated and large.

(2) The half mirror reflects the illumination light emitted from the illumination means in a direction normal to the peripheral surface of the inspection object,
It is characterized by transmitting reflected light in the normal direction on the peripheral surface of the inspection object.

In this configuration, the illuminating light emitted from the illuminating means is reflected on the half mirror in the normal direction of the peripheral surface of the inspection object, and the reflected light reflected on the peripheral surface of the inspection object in the normal direction is reflected on the half mirror. Transmitted through. Therefore, the illumination light is incident on the illumination position on the peripheral surface of the inspection target in the normal direction, and the regular reflection light in the normal direction on the illumination position on the inspection object peripheral surface is received by the light receiving unit,
Even when an error or rotation unevenness from the true circle of the inspection object occurs, and when the radius of the inspection object changes, reflected light in a state close to regular reflection light is reliably received by the light receiving unit, and the inspection object The presence or absence of a defect on the peripheral surface is always accurately inspected.

(3) The half mirror transmits illumination light emitted from the illumination means in a direction normal to the peripheral surface of the inspection object,
It is characterized by reflecting reflected light in the normal direction on the peripheral surface of the inspection object.

In this configuration, the illuminating light emitted from the illuminating means in the normal direction of the peripheral surface passes through the half mirror,
The reflected light reflected in the normal direction on the peripheral surface of the inspection target is reflected on the half mirror in parallel to a direction orthogonal to the normal direction. Therefore, the illumination light is incident on the illumination position on the peripheral surface of the inspection target in the normal direction, and the specular reflection light in the normal direction on the illumination position on the peripheral surface of the inspection target is received by the light receiving unit. When an error from a perfect circle or rotation unevenness occurs, and even when the radius of the inspection target changes, reflected light in a state close to regular reflection light is reliably received by the light receiving means, and the peripheral surface of the inspection target The presence or absence of a defect is always accurately inspected.

(4) In a cylindrical surface inspection method for irradiating the peripheral surface of a cylindrical inspection object with illumination light and receiving the reflected light on the peripheral surface of the inspection object, the illumination light is transmitted through a half mirror to the peripheral surface of the inspection object. The surface is irradiated in the normal direction, and reflected light reflected in the normal direction from the peripheral surface of the inspection target is received via the half mirror.

In this configuration, the peripheral surface of the inspection object is irradiated with the illumination light in the normal direction, and the reflected light reflected in the normal direction from the peripheral surface of the inspection object is received by the light receiving means. Therefore, dα / d representing the change amount α of the reflection angle, where x is the displacement in the direction perpendicular to the normal direction of the inspection object
θ at x = 1 / (R · cos θ) becomes “0”,
The value of α becomes minimum from cos0 ° = 1. Further, the reflection angle of the light reflected in the normal direction on the peripheral surface of the inspection target does not change depending on the displacement y in the normal direction of the inspection target. For this reason, when an error or rotation unevenness from a perfect circle of the inspection object occurs, and even when the radius of the inspection object changes, regular reflection light in a state close to regular reflection light is reliably received by the light receiving unit, The presence or absence of a defect on the peripheral surface of the inspection target is always accurately inspected.

(5) The illumination light is reflected by the half mirror and radiated in the normal direction to the peripheral surface of the inspection object, and the reflected light reflected in the normal direction from the peripheral surface of the inspection object is transmitted through the half mirror. And receiving light.

In this configuration, the illuminating light emitted from the illuminating means is reflected on the half mirror in the normal direction of the peripheral surface of the inspection object, and the reflected light reflected on the peripheral surface of the inspection object in the normal direction is reflected on the half mirror. Transmitted through. Therefore, the illumination light is incident on the illumination position on the peripheral surface of the inspection target in the normal direction, and the regular reflection light in the normal direction on the illumination position on the inspection object peripheral surface is received by the light receiving unit,
Even when an error or rotation unevenness from the true circle of the inspection object occurs, and when the radius of the inspection object changes, reflected light in a state close to regular reflection light is reliably received by the light receiving unit, and the inspection object The presence or absence of a defect on the peripheral surface is always accurately inspected.

(6) Illumination light is transmitted through the half mirror to irradiate the peripheral surface of the inspection target in the normal direction, and reflected light reflected in the normal direction from the peripheral surface of the inspection target is reflected by the half mirror. And receiving light.

In this configuration, the illuminating light emitted from the illuminating means in the normal direction of the peripheral surface passes through the half mirror,
The reflected light reflected in the normal direction on the peripheral surface of the inspection target is reflected on the half mirror in parallel to a direction orthogonal to the normal direction. Therefore, the illumination light is incident on the illumination position on the peripheral surface of the inspection target in the normal direction, and the specular reflection light in the normal direction on the illumination position on the peripheral surface of the inspection target is received by the light receiving unit. When an error from a perfect circle or rotation unevenness occurs, and even when the radius of the inspection target changes, reflected light in a state close to regular reflection light is reliably received by the light receiving means, and the peripheral surface of the inspection target The presence or absence of a defect is always accurately inspected.

[0020]

FIG. 1 is a diagram showing a configuration of a cylindrical surface inspection apparatus according to a first embodiment of the present invention. The cylindrical surface inspection device 10 according to the first embodiment of the present invention includes:
As shown in FIG. 1A, an inspection object 4 such as a photosensitive drum
, A line sensor 1 which is a light receiving means of the present invention for imaging the peripheral surface of the present invention, a halogen lamp 3 which is an illuminating means of the present invention for irradiating the peripheral surface of the inspection object 4 with illumination light, and illumination radiated from the halogen lamp 3 A half mirror 2 that reflects light in a direction normal to the peripheral surface of the inspection target 4 and transmits specularly reflected light in a direction normal to the peripheral surface of the inspection target 4. Note that the line sensor 1 includes a lens that forms regular reflection light on the peripheral surface of the inspection target 4 into an image on a light receiving unit of the line sensor 1.

The cylindrical surface inspection apparatus 10 according to this embodiment
Reflects the illumination light on the half mirror 2 and irradiates the peripheral surface of the inspection object 4 in the normal direction, and transmits the regular reflection light reflected in the normal direction from the peripheral surface of the inspection object 4 through the half mirror 2 This is to implement a cylindrical surface inspection method for receiving light.
That is, the cylindrical surface inspection apparatus 10 rotates the inspection object 4 at a predetermined speed around the longitudinal direction as a rotation axis, and reflects the reflected light of the illumination light emitted from the halogen lamp 3 on the peripheral surface of the inspection object 4 as the inspection object. 4 is read by the line sensor 1 over the entire circumference, and the presence or absence of a defect on the peripheral surface of the inspection target 4 is inspected based on the light receiving signal of the line sensor 1.

FIG. 1B is a view showing the arrangement position of each member in the cylindrical surface inspection apparatus and the optical axis direction of illumination light and reflected light. The halogen lamp 3 irradiates the illumination light in a direction perpendicular to the normal direction of the illumination position on the peripheral surface of the inspection target 4, that is, in a direction parallel to the tangent direction of the illumination position. The line sensor 1 is arranged on the normal line of the illumination position on the peripheral surface of the inspection target 4. Half mirror 2
It is arranged in the optical path of the illumination light and the optical path of the reflected light at an angle of 45 degrees with respect to the irradiation direction of the illumination light and the reflection direction of the reflected light.

As described above, the half mirror 2 reflects the illumination light emitted from the halogen lamp 3 in the normal direction of the peripheral surface of the inspection object 4. Therefore, the illumination light emitted from the halogen lamp 3 is reflected by the half mirror 2 and is incident on the peripheral surface of the inspection object 4 in the normal direction. The half mirror 2 transmits specularly reflected light in the normal direction on the peripheral surface of the inspection target 4. Therefore, the regular reflection light of the illumination light on the peripheral surface of the inspection object 4 passes through the half mirror 2 and is received by the line sensor 1.

In the configuration shown in FIG. 1B, since the incident angle θ of the illumination light is “0”, when the inspection object 4 is displaced x and y due to a change in radius or rotation unevenness, cos 0 °.
= 1, the above equation 1 becomes dα / dx = 1 / R, and when the displacement x of the inspection object 4 in the direction orthogonal to the incident direction of the illumination light is fixed, the angle change α of the optical axis of the reflected light is the minimum. Value. Further, there is no change in the angle of the optical axis of the reflected light depending on the displacement y of the inspection object 4 in the direction orthogonal to the incident direction of the illumination light.

Therefore, according to the above configuration, even when the radius of the inspection object 4 changes or the rotation becomes uneven, the direction of reflection of the reflected light from the peripheral surface of the inspection object 4 does not greatly change. The reflected light in a state close to the regular reflected light on the peripheral surface of the inspection target 4 can be reliably received by the line sensor 1.

FIG. 2 is a block diagram showing the configuration of the processing unit of the above-mentioned cylindrical surface inspection apparatus. The detection signal of the line sensor 1 that has received the reflected light on the peripheral surface of the inspection target 4 is input to the processing unit 5. The processing unit 5 includes an image processing unit 6, an image memory 7, a defect inspection unit 8, and an actual processing unit 9. The image processing unit 6 outputs image data subjected to predetermined image processing after A / D conversion of the detection signal of the line sensor 1. The image memory 7 stores the image data of the entire circumference of the inspection target 4 output from the image processing unit 6. Defect inspection unit 8
Reads the image data stored in the image memory 7, determines the presence or absence of a defect, and detects the position of the defect if it exists. The actual processing unit 9 performs processes such as displaying the inspection result in the defect inspection unit 8 and sorting the inspection target 4 based on the inspection result.

FIG. 3 is a view showing a configuration of a cylindrical surface inspection apparatus according to a second embodiment of the present invention. The cylindrical surface inspection apparatus 20 according to the second embodiment of the present invention transmits illumination light through the half mirror 2 to irradiate the peripheral surface of the inspection object 4 in the normal direction, and from the peripheral surface of the inspection object 4 This is to implement a cylindrical surface inspection method in which reflected light reflected in the normal direction is reflected by the half mirror 2 and received. For this reason, as shown in FIG. 3A, the cylindrical surface inspection device 20 includes the line sensor 1 and the half mirror 2 as in the configuration shown in FIG.
And a halogen lamp 3.

A cylindrical surface inspection apparatus 2 according to a second embodiment
0 differs from the cylindrical surface inspection apparatus 10 according to the first embodiment in that the arrangement positions of the line sensor 1 and the halogen lamp 3 with respect to the half mirror 2 and the inspection object 4 are interchanged. That is, as shown in FIG. 3B, the halogen lamp 3 as the illumination means of the present invention irradiates the illumination light in the normal direction of the illumination position on the peripheral surface of the inspection object 4. The line sensor 1 is arranged in a direction orthogonal to the normal direction of the illumination position on the peripheral surface of the inspection object 4, that is, on a line parallel to a tangent to the illumination position. The half mirror 2 is arranged in the optical path of the illumination light and the optical path of the reflected light at an angle of 45 degrees with respect to the irradiation direction of the illumination light and the reflection direction of the reflected light.

As described above, the half mirror 2 transmits the illumination light emitted from the halogen lamp 3. Therefore, the illumination light emitted from the halogen lamp 3 is reflected by the half mirror 2 and is incident on the peripheral surface of the inspection object 4 in the normal direction. The half mirror 2 reflects light reflected in the normal direction on the peripheral surface of the inspection target 4 in a direction orthogonal to the normal direction. Therefore, the reflected light of the illumination light on the peripheral surface of the inspection target 4 is reflected by the half mirror 2 and received by the line sensor 1.

Note that the cylindrical surface inspection device 20 according to the second embodiment is the same as the cylindrical surface inspection device 10 according to the first embodiment.
The processing unit 5 is provided in the same manner as described above, and performs processing according to the inspection result of the inspection target 4 based on the detection signal output from the line sensor 1 that has received the reflected light on the peripheral surface of the inspection target 4.

Also in the configuration shown in FIG. 3B, the incident angle θ of the illumination light is “0”, so that when the inspection object 4 is displaced x and y due to a change in radius or uneven rotation, cos 0 °.
= 1, the above equation 1 becomes dα / dx = 1 / R, and when the displacement x of the inspection object 4 in the direction orthogonal to the incident direction of the illumination light is fixed, the angle change α of the optical axis of the reflected light is the minimum. Value. Further, there is no change in the angle of the optical axis of the reflected light depending on the displacement y of the inspection object 4 in the direction orthogonal to the incident direction of the illumination light.

Therefore, according to the above configuration, even when a change in radius or rotation unevenness occurs in the inspection object 4, the direction of reflection of light reflected from the peripheral surface of the inspection object 4 does not greatly change. The reflected light in a state close to the regular reflected light on the peripheral surface of the inspection target 4 can be reliably received by the line sensor 1.

[0033]

According to the present invention, the following effects can be obtained.

(1) Illumination light is radiated in the normal direction on the peripheral surface of the inspection object, and reflected light reflected in the normal direction from the peripheral surface of the inspection object is received by the light receiving means. Dα / dx = 1 / (R · cos) representing the change amount α of the reflection angle, where x is the displacement in the direction orthogonal to the linear direction.
Since θ in (θ) becomes “0”, the value of α becomes minimum from cos0 ° = 1. Further, the reflection angle of the light reflected in the normal direction on the peripheral surface of the inspection target does not change depending on the displacement y in the normal direction of the inspection target. For this reason, when an error from a perfect circle to be inspected or rotation unevenness occurs, and
Even when the radius of the inspection object changes, the regular reflection light in a state close to the regular reflection light can be reliably received by the light receiving means, and the presence or absence of a defect on the peripheral surface of the inspection object can always be accurately inspected. it can. In addition, since a single half mirror is arranged in the optical path of the illumination light and the reflected light, it is possible to prevent the configuration of the apparatus from becoming complicated and large.

(2) The illuminating light emitted from the illuminating means is reflected on the half mirror in the normal direction of the peripheral surface of the inspection object, and the reflected light reflected on the peripheral surface of the inspection object in the normal direction is transmitted to the half mirror. This allows the illumination light to enter the illumination position on the peripheral surface of the inspection object in the normal direction, and receives the regular reflection light in the normal direction at the illumination position on the peripheral surface of the inspection object by the light receiving unit. Even when an error from the perfect circle of the inspection object or rotation unevenness occurs, or when the radius of the inspection object changes, reflected light in a state close to regular reflection light is reliably received by the light receiving unit. And the presence or absence of a defect on the peripheral surface of the inspection object can always be inspected accurately.

(3) The illuminating light emitted from the illuminating means in the normal direction of the peripheral surface is transmitted through the half mirror, and the reflected light reflected in the normal direction on the peripheral surface to be inspected is reflected in the normal direction on the half mirror. By reflecting the light parallel to the orthogonal direction, the illumination light can be made to enter the illumination position on the peripheral surface of the inspection target in the normal direction, and the normal light in the illumination position on the peripheral surface of the inspection target can be reflected in the normal direction. The reflected light can be received by the light receiving means, and the reflected light is close to the regular reflected light even when an error from the perfect circle of the inspection object or rotation unevenness occurs, or when the radius of the inspection object changes. Can be reliably received by the light receiving means, and the presence or absence of a defect on the peripheral surface of the inspection object can always be inspected accurately.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a cylindrical surface inspection device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a configuration of a processing unit of the cylindrical surface inspection device.

FIG. 3 is a diagram showing a configuration of a cylindrical surface inspection device according to a second embodiment of the present invention.

FIG. 4 is a diagram showing a configuration of a conventional cylindrical surface inspection device.

FIG. 5 is a diagram showing an arrangement position of each member and an optical path of illumination light and reflected light in a conventional cylindrical surface inspection device.

[Explanation of symbols]

 1-Line sensor (light receiving means) 2-Half mirror 3-Halogen lamp (illuminating means) 4-Inspection object 5-Processing unit 6-Image processing unit 7-Image memory 8-Defect inspection unit 9-Real processing unit 10,20 −Cylinder surface inspection device

Claims (6)

[Claims] An illumination means for irradiating illumination light to a peripheral surface of a cylindrical inspection object, and a light receiving means for receiving reflected light of the illumination light emitted from the illumination means on the peripheral surface of the inspection object. In the cylindrical surface inspection apparatus, the illumination unit irradiates the illumination light in a normal direction to a peripheral surface of the inspection target via a half mirror, and the light receiving unit reflects in a normal direction from the peripheral surface of the inspection target. A cylindrical surface inspection apparatus characterized by receiving reflected light via a half mirror. 2. The method according to claim 1, wherein the half mirror reflects the illumination light emitted from the illumination means in a direction normal to the peripheral surface of the inspection target, and transmits the reflected light in a direction normal to the peripheral surface of the inspection target. The cylindrical surface inspection device according to claim 1, wherein 3. The half mirror transmits illuminating light emitted from the illuminating means in a direction normal to the peripheral surface of the inspection target, and reflects reflected light in a direction normal to the peripheral surface of the inspection target. The cylindrical surface inspection device according to claim 1, wherein 4. A cylindrical surface inspection method for irradiating a peripheral surface of a cylindrical inspection object with illumination light and receiving reflected light on the peripheral surface of the inspection object, wherein the illumination light is transmitted through a half mirror to the peripheral surface of the inspection object. A cylindrical surface inspection method comprising: irradiating a light beam in a normal direction with respect to an object, and receiving reflected light reflected in a normal direction from a peripheral surface of the inspection object through a half mirror. 5. An illumination light is reflected by a half mirror and radiated in a normal direction to a peripheral surface of the inspection object, and reflected light reflected in a normal direction from the peripheral surface of the inspection object is transmitted through the half mirror. The cylindrical surface inspection method according to claim 4, wherein light is received. 6. An illumination light is transmitted through a half mirror to irradiate the peripheral surface of the inspection object in a normal direction, and reflected light reflected in a normal direction from the peripheral surface of the inspection object is reflected by the half mirror. The cylindrical surface inspection method according to claim 4, wherein light is received.