JPH09145339A - Surface defect inspection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a surface flaw inspection method in which two kinds of surface having different properties can be checked for flaw at the time of inspecting an object having two kinds of surface having different properties. SOLUTION: A CCD camera 13 is arranged at such light receiving angle βas the regular reflection, light has higher light receiving angle than a regular reflected light from the CCD camera 13 when light is irradiated from the CCD camera 13 to the surface of a photosensitive drum 11 having a coated face 11a and metal faces 11b, 11c and the quantity of light reflected from the coated face 11a and metal faces 11b, 11c is reversed. Flaw on the photosensitive drum 11 is detected based on a reflected light received by the CCD camera 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for inspecting surface defects, and particularly to an inspection having two types of surfaces having different surface states such as a photoconductor having metal surfaces at both ends and a coated surface at the center. The present invention relates to a surface defect inspection method capable of simultaneously inspecting two types of surfaces when inspecting an object.

[0002]

2. Description of the Related Art One example of an object to be inspected is a photoconductor drum of a copying machine. First, in FIG. 11, the copying process is briefly described to clarify the structure of the inspection target. Figure
In FIG. 11 (a), 1 is a photoconductor drum built in the copying machine, and around the photoconductor drum 1, a corona charger 2, an exposure device 3, a developing device 4, a transfer device 5, and a separator 6 are provided. A cleaner 7, a static eliminator 8 and a fixing device 9 are arranged.

With such an apparatus configuration, first, the surface of the photosensitive drum 1 is uniformly charged by the corona charger 2 in the dark portion, and the light corresponding to the image information of the original is provided on the portion other than the image forming portion by the exposure device 3. Is radiated to remove the charged electric charge in the light-irradiated portion to form an electrostatic latent image in which the electric charge remains in the image forming portion. The developing device 4 supplies and attaches the toner T, which is the colored fine particles charged in the opposite magnetic field to the electrostatic latent image, to the electrostatic latent image from the developing roller 4a to form a visible image. Then
The recording paper P is attached to the toner image, and the transfer device 5 applies a charge having a magnetic field opposite to the magnetic pole of the toner T to the recording paper P from the back surface of the recording paper P, and the toner image is transferred to the recording paper P by electrostatic force. At the same time, the recording paper P after transfer is separated from the photosensitive drum 1 side by the separator 6. The transferred toner image is subjected to heat or pressure by the fixing device 9, and the toner image is fused on the recording paper P to become a permanent image.

On the other hand, the toner remaining on the photosensitive drum 1 without being transferred is removed from the photosensitive drum 1 by the cleaner 7. The electrostatic latent image on the photosensitive drum 1 is neutralized by the neutralizer 8. By repeating a series of processes from charging to discharging in this manner, copying is continuously performed on the succeeding recording paper. By the way, in such a photosensitive drum 1, since the gap between the developing roller 4a and the photosensitive drum 1 needs to be kept constant in order to properly attach the toner T to the surface, the rotation axis of the developing roller 4a. The guide plates 10 are provided at both ends of the photosensitive drum 1, and the guide plates 10 are brought into contact with both ends of the photosensitive drum 1 to rotate the drum 1.

Therefore, both end portions 1a of the photosensitive drum 1 are
As shown in FIG. 1B, 1b has a metal surface of about 10 mm, and the photoreceptor is not applied. It should be noted that each dimension in FIG. 3B represents an actual dimension of the photosensitive drum 1. As a device for inspecting such scratches on the surface of the photosensitive drum 1, for example, Japanese Patent Laid-Open No. 4-169 is known.
The one described in Japanese Patent No. 840 is known. This is because when the coated surface (photosensitive surface) of the photosensitive drum 1 is irradiated with light, the light reflected from the surface without scratches is specularly reflected. The line sensor is arranged at a position where the generated light is received.

Further, as a device for inspecting the surface of a metal surface (or plastic, paper, etc.) for scratches, for example, the one disclosed in Japanese Patent Laid-Open No. 5-280958 is known. This one irradiates a metal surface with light, receives the reflected light with a line sensor, converts the image signal obtained by converting it into a potential signal, and after spatial filtering processing including a differential filter to obtain a differential image, An area including a scratch on the metal surface is extracted using this differential image.

[0007]

However, in both of these surface defect inspection methods, only scratches on the surface having the same properties such as the coated surface and the metal surface of the photoconductor drum 1 can be obtained. Since it cannot be detected, there is a problem that defects such as scratches on the surface having different properties cannot be detected at the same time.

Therefore, the present invention aims to provide a surface defect inspection method capable of simultaneously inspecting the presence or absence of defects on two types of surfaces when inspecting an inspection object having two types of surfaces having different properties. I am trying.

[0009]

According to the first aspect of the present invention,
In order to solve the above-mentioned problems, an inspection target having two types of surfaces having different properties is uniformly irradiated with light from a light source, and reflected light from the surface of the inspection target is received by a line sensor, and the line sensor A surface defect inspection method for detecting a defect of an inspection object based on the reflected light received by, wherein specularly reflected light is reflected by a line sensor when the inspection object is irradiated with light. One line sensor is arranged at a light receiving angle that is larger than the angle and the amount of light reflected from a surface having different properties is reversed, and a defect to be inspected is detected based on the reflected light received by the line sensor. It is characterized by having done.

In this case, if one of the surfaces to be inspected is a metal surface and the other is a coated surface (photosensitive surface), when the inspection object is irradiated with light, specularly reflected light is received by the line sensor. If the line sensor is arranged at an angle, it is not suitable for inspection because it is greatly affected by unevenness of the light source, vibration of the surface of the inspection target, etc. When the line sensor is arranged at a position larger than the regular reflection light reception angle where this effect does not appear, the amount of light received by the line sensor decreases and the inspection is performed as the reception angle becomes closer to the incident angle, as shown in FIG. The light receiving sensitivity with respect to minute irregularities on the surface of the object is increased.

Here, considering the difference between the metal surface and the coated surface, when receiving specularly reflected light, the output is large because the reflectance of the metal surface is high. Further, when the light receiving angle is largely changed from the regular reflection light receiving angle, the coated surface diffuses light, so that a diffused light region having a substantially flat output continues on both sides of the regular reflection light receiving region. On the other hand, in the case of metal, since it has no diffusivity, the range of light that can be received is narrow. Therefore, the output is reversed on the metal surface to be larger than the output on the coated surface at a certain light receiving angle.

Therefore, in order to increase the sensitivity to minute unevenness defects on the coated surface, the light receiving angle is made closer to the incident angle so that the influence of unevenness of the light source or the vibration of the surface of the inspection object does not appear. Also, one line sensor is placed at the light-receiving angle where the amount of light reflected from the coated surface and the metal surface is reversed, and the reflected light from the metal surface and the reflected light from the coated surface are processed by a simple binarization process. It is possible to separate and easily detect defects such as surface protrusions and scratches from the amount of change in this signal. As a result, one line sensor can simultaneously inspect for two types of surface defects.

In order to solve the above-mentioned problems, the invention according to claim 2 uniformly irradiates an inspection object having two kinds of surfaces having different properties with light from a light source and reflects the light from the surface of the inspection object. A surface defect inspection method of receiving light by a line sensor and detecting a defect of an inspection object based on reflected light received by the line sensor, wherein specular reflection light is generated when the inspection object is irradiated with light from the light source. One line sensor is arranged so that the light receiving angle is larger than the light receiving angle of the specularly reflected light reflected by the line sensor, and between the surface having the large amount of reflected light and the light source of the two types of surfaces. Further, a polarizing plate is arranged between the surface and the line sensor, and the reflected light received by the line sensor is detected as a defect of the inspection object.

In that case, as shown in FIG. 2, even if the line sensor is arranged at a light receiving angle γ1 which is larger than the regular reflected light receiving angle and exceeds the saturation level of the line sensor, the reflected light from the normal surface is transmitted. Instead, if a deflecting plate configured to transmit only the reflected light when there is a defect such as a protrusion or a scratch on the surface and the deflection direction of the reflected light changes, the reflected light can be detected. It can be detected as a surface defect.

In order to solve the above-mentioned problems, the invention described in claim 3 uniformly irradiates a test object having two kinds of surfaces having different properties with light from a light source and reflects the light from the surface of the test object. A surface defect inspection method of receiving light by a line sensor and detecting a defect of an inspection object based on reflected light received by the line sensor, wherein specular reflection light is generated when the inspection object is irradiated with light from the light source. Is arranged such that the light receiving angle is larger than the light receiving angle of the specularly reflected light reflected by the line sensor, and the surface and the line sensor of the two types of surfaces having a large amount of reflected light An optical filter for reducing the amount of light is arranged between them, and the defect of the inspection object is detected based on the reflected light received by the line sensor.

In this case, as shown in FIG. 2, even if the line sensor is arranged at a light receiving angle γ1 that is larger than the regular reflected light receiving angle and exceeds the saturation level of the line sensor, the light quantity of the reflected light is reduced by the optical filter. By doing so, the presence or absence of defects on the surface of the inspection object can be inspected from the change in the light received through this filter. In order to solve the above-mentioned problems, the invention according to claim 4 is, in the invention according to any one of claims 1 to 3, reflected from an inspection object between two types of surfaces having different properties and a line sensor. It is characterized in that separate reflecting mirrors are arranged at different angles so as to guide the reflected light to the line sensor.

In this case, even if the position of the line sensor is set to any position with respect to the inspection object, the light reflected from the surface of the inspection object is received by the reflection mirror provided for each surface having different properties. The light can be guided to the line sensor so that the light receiving angle is larger than the angle, and the presence or absence of defects on the two types of surfaces to be inspected can be inspected.

In order to solve the above-mentioned problems, the invention described in claim 5 uniformly irradiates a test object having two kinds of surfaces having different properties with light from a light source and reflects the light from the surface of the test object. A surface defect inspection method of receiving light by a line sensor and detecting a defect of an inspection target based on reflected light received by the line sensor, wherein specular reflection is performed when the inspection target is irradiated with light from the line sensor. Line sensors are provided one by one according to the surface having different properties so that the light is larger than the reception angle of the specularly reflected light reflected by the line sensor, and the defect to be inspected is detected based on the reflected light received by the line sensor. The feature is that it is detected.

In that case, even if the mechanical and structural accuracy of the line sensor or the shaft center of the inspection object is not sufficient,
By providing one line sensor for each surface having different properties, the presence or absence of defects on the two types of surfaces to be inspected can be inspected with high accuracy. In order to solve the above problems, the invention according to claim 6 is characterized in that, in the invention according to any one of claims 1 to 5, one surface having different properties is irradiated with diffused light.

In this case, when one surface is a metal surface, the influence of irregular reflection on the metal surface can be eliminated, and the presence or absence of defects on the two types of surfaces to be inspected can be inspected with high accuracy. . In order to solve the above-mentioned problems, the invention according to claim 7 irradiates an inspection object having two types of surfaces having different properties with light, and detects defects of the inspection object based on the reflected light from the surface of the inspection object. In the surface defect inspection method to detect, if the width direction length of one surface having different properties is long, the specular reflection light has a light-receiving angle larger than the specular reflection light reception angle reflected by the line sensor. A line sensor is arranged on the line sensor, a defect on one surface is detected based on the reflected light received by this line sensor, and when the width direction length of the other surface having different properties is short, a scanning laser displacement meter is used. It is characterized by using it to detect a defect on the other surface.

In this case, one of the surfaces can be inspected by detecting the light emitted from the light source with a line sensor, and the other surface is provided with a scanning laser displacement meter. Therefore, it is possible to simultaneously inspect for defects of two types of surfaces. In addition, since the surface with a short width in the width direction is inspected by the scanning laser displacement meter, the size of the protrusion or scratch can be measured in addition to the inspection of the presence or absence of a defect such as a protrusion or scratch on the surface. .

In order to solve the above-mentioned problems, the invention according to claim 8 irradiates an inspection object having two kinds of surfaces having different properties with light, and the inspection object is based on the reflected light from the surface of the inspection object. In the surface defect inspection method for detecting defects of No. 3, when the width direction length of one surface having different properties is long, the light receiving angle larger than the light receiving angle of the regular reflected light reflected by the line sensor The line sensor is arranged so that the defect on one surface is detected based on the reflected light received by this line sensor. It is characterized in that the surface is scanned with a laser beam and a defect on the other surface is detected based on the reflected light of the laser beam.

In this case, one surface can be inspected by detecting the light emitted from the light source by the line sensor, and the other surface can be scanned by the laser light source. The inspection can be performed based on the reflected light, and as a result, the presence or absence of defects on the two types of surfaces can be inspected at the same time.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described below based on Examples. 1 and 2 are diagrams showing a first embodiment of an inspection apparatus for achieving a surface defect inspection method according to the present invention, and correspond to claim 1. First, the configuration will be described. In FIG. 1, reference numeral 11 denotes a photosensitive drum to be inspected, the central portion of the photosensitive drum 11 has a coating surface 11a coated with a photosensitive member, and both end surfaces of the photosensitive drum 11 and the developing device are provided. A metal surface that is in sliding contact with the guide plate to keep the gap with the developing roller uniform
It has 11b and 11c. That is, the photosensitive drum 11 has two types of surfaces having different properties.

A line-shaped light source 12 such as a halogen lamp is provided on the outer peripheral surface of the photosensitive drum 11 in the axial direction thereof, and light is emitted from the light source 12. A one-dimensional CCD camera 13 as a line sensor is provided at a position orthogonal to the center of the photosensitive drum 11 in the axial direction, and the reflected light from the photosensitive drum 11 is received by the CCD camera 13. Has become.

The CCD camera 13 has a photosensitive drum 11 with respect to an angle α at which light is incident on the photosensitive drum 11 from the light source 12.
It is arranged at a position (α <β) where the light receiving angle β reflected by the CCD camera 13 and received by the CCD camera 13 increases.
That is, in the CCD camera 13, the specular reflection light
It is arranged at an angle larger than the light receiving angle of the specular reflection light reflected from the coating surface 11 as described later.
a and the metal surfaces 11b and 11c are arranged at a light-receiving angle at which the amounts of light reflected are reversed.

Further, the optical signal received by the CCD camera 13 is subjected to noise removal, filter calculation processing, binarization processing and labeling processing by an image processing means (not shown), so that the coating surface 11a has a dot shape and an uneven shape. Defects, such as protrusions and scratches on the metal surfaces 11b and 11c, are detected. Next, the operation will be described.

In order to inspect the surface of the photosensitive drum 11 for defects, the surface of the photosensitive drum 11 is uniformly irradiated with light at an incident angle α while rotating the photosensitive drum 11, and the light receiving angle β This reflected light is received by the CCD camera 13 disposed in the above, and the optical signal is subjected to noise removal, filter calculation processing, binarization processing and labeling processing, and dot-shaped and uneven defects on the coated surface 11a, metal surface 11b. , 11c, defects such as protrusions and scratches are detected.

The present embodiment is characterized in that the CCD camera 13 is arranged so that the optical signal from the surface having this different property can be easily processed by the image processing means. explain. First, the relationship between the light receiving angle β and the output of the CCD camera 13 will be considered. Light receiving angle β
The reflected light intensity is highest when is equal to the incident angle α.
At this time, the incident angle α is equal to the light receiving angle β, and the specular reflection light is received, and the influence of unevenness of the light source 12 and the vibration of the surface of the photoconductor drum 11 greatly appears in the image. Don't pick it up.

As shown in FIG. 2, the amount of light received by the CCD camera 13 decreases as the light receiving angle β moves away from the incident angle α, and the photosensitive drum 11 becomes closer as the light receiving angle β approaches the incident angle α. Has the property of increasing sensitivity to minute irregularities on the surface of the. Here, the coated surface 11a and the metal surface
Considering the difference in the properties of 11b and 11c, when the CCD camera 13 receives the regular reflection angle,
Since 11b and 11c have higher reflectance, the output is larger. When the light receiving angle β is changed, the coated surface 11
Since a has a function of diffusing light, a diffused light receiving area having a substantially flat output continues on both sides of the specularly reflected light receiving area, while metal surfaces 11b and 11c have no diffusivity.
The light receiving range is narrow.

Therefore, the output of the coated surface 11a exceeds the output of the metal surfaces 11b and 11c and is reversed at a certain light receiving angle. In this embodiment, the CCD camera 13 is arranged at this reverse position. An explanation will be given by comparing those in which the CCD cameras 13 are arranged at the respective positions γ1 to γ4 based on FIG.

In order to increase the sensitivity to minute unevenness defects on the coated surface 11a, the light receiving angle β should be set to the incident angle α as much as possible so that the influence of unevenness of the light source 12 and vibration of the surface of the photosensitive drum 11 does not appear. Get closer. At that time, the light receiving angle β is γ1
Then, the reflected light intensity from the metal surfaces 11b and 11c is CCD.
It is considered that the saturation level of the camera 13 will be exceeded. Therefore, the light receiving angle β will be changed further. If the metal surfaces 11b and 11c are not mirror-finished, the reflected light is diffusely reflected, and even on a normal surface having no defect, the optical signal has a very large variation in density, and it becomes difficult to extract the defect. .

Therefore, the light receiving angle β is further changed so that the reflected light intensity from the coated surface 11a becomes equal to the reflected light intensity from the metal surfaces 11b and 11c (the light receiving angle β is set to γ3). At this time, the variation in the density due to the irregular reflection of the metal surfaces 11b and 11c becomes small, but it becomes impossible to separate the metal surfaces 11b and 11c and the coated surface 11a by simple binarization.

Further, consider a case where the light receiving angle β is greatly changed and the intensity of the reflected light from the metal surfaces 11b and 11c becomes smaller than the intensity of the reflected light from the coated surface 11a (the light receiving angle β is set to γ4). Considering the coated surface 11a, the sensitivity to minute irregularities decreases, but if there is a density difference between defects, this can be sufficiently detected. Meanwhile, metal surface
Since the angles 11b and 11c are such that the reflected light is hardly received, the output of the CCD camera 13 is small on a normal surface having no defects, and there is no influence of irregular reflection. If there is a defect such as a protrusion or a scratch, the light is scattered and only that part becomes bright, and the defect can be detected based on this light. That is, the defect can be detected in the dark field. Further, the output signals of the coated surface 11a and the metal surfaces 11b and 11c are subjected to simple binarization processing by the image processing device, so that the coated surface 11a and the metal surfaces 11b and 11c can be separated. Specifically, the coated surface 11a and the metal surface 11
If a threshold value is set for a predetermined intensity between the reflected light intensities from b and 11c and the reflected light intensity is smaller than this threshold, a metal surface
11b and 11c are detected, and when the reflected light intensity is higher than the threshold, the coated surface 11a is detected.

Since the metal surfaces 11b and 11c can be extracted from the intensity of the reflected light, it is possible to detect the area of the pixel of the camera 13 where the light received by the CCD camera 13 is detected. It is possible to measure the width of the metal surfaces 11b and 11c. As described above, in this embodiment, the photosensitive drum 11 having the coated surface 11a and the metal surfaces 11b and 11c.
When light is irradiated from the CCD camera 13 to the surface of the, the regular reflection light is larger than the regular reflection light reception angle reflected by the CCD camera 13, and the amount of light reflected from the coating surface 11a and the metal surfaces 11b and 11c is CCD camera 13 at the light receiving angle β that reverses
Is arranged and the defect of the photoconductor drum 13 is detected based on the reflected light received by the CCD camera 13,
With one CCD camera 13, it is possible to inspect for two types of surface defects at the same time.

In this embodiment, the photosensitive drum 11 is the object to be inspected, but the present invention is not limited to this, and any object having two types of surfaces having different properties may be inspected. 3 is a diagram showing a second embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention.
It corresponds to. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 3, reference numerals 15a and 16a denote deflecting plates. The deflecting plates 15a and 16a are arranged between the photoconductor drum 11 and the light source 12, and irradiate the metal surfaces 11b and 11C with light. ing. Further, the deflecting plates 15b and 16b are provided on the photosensitive drum 11.
The deflecting plates 15a, 15b, 16a, 16b are arranged between the metal surfaces 11b, 11c having a large quantity of reflected light and the CCD camera 13 and the deflecting plates 15a, 15b, 16a, 16b are normal surfaces without defects. When a defect is detected and the deflection direction of the reflected light is deviated without transmitting the reflected light from the device 1, only the portion is transmitted to the CCD camera 13 as a defect signal.

In this embodiment, the light receiving angle β is set to the metal surface 11b,
An angle that is larger than the regular reflection light reception angle and that can detect minute unevenness defects on the coated surface 11a without considering the reflected light of 11c,
For example, the angle is set to γ1 in FIG. In this case, the reflected light intensity on the metal surfaces 11b and 11c is CCD.
The saturation level of camera 13 has been exceeded. In this embodiment, the light from the light source 12 is directly applied to the coating surface 11a of the photoconductor drum 11, and the deflecting plates 15a and 16 are provided on the metal surfaces 11b and 11c.
Light reflected from the metal surfaces 11b and 11c, which is emitted through a, is reflected by the deflection plates 15b and 16b. These deflection plates 15b and 16a
Does not allow the reflected light from a normal surface having no defect to pass through, but when the defect is detected and the deflection direction of the reflected light is deviated, only that part is transmitted as a defect signal to the CCD camera 13. When the signal is received by the CCD camera 13, it can be detected as a defect on the surface of the metal surfaces 11b and 11C. The method of detecting the defects on the coated surface 11a is the same as that in the first embodiment, and thus the description thereof is omitted.

FIG. 4 is a diagram showing a third embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention.
It corresponds to. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 4, reference numeral 17 is an optical filter such as an ND filter or an interference filter having a property of reducing the amount of light, and the optical filter 17 is arranged between the photosensitive drum 11 and the CCD camera 13.

Also in this embodiment, the light receiving angle β is set to the metal surface 11b,
An angle that is larger than the regular reflection light reception angle and that can detect minute unevenness defects on the coated surface 11a without considering the reflected light of 11c,
For example, the angle γ1 in FIG. 2 at which the reflected light intensity on the metal surfaces 11b and 11c exceeds the saturation level of the CCD camera 13 is set. Also in this embodiment, when the light from the light source 12 is applied to the coated surface 11a and the metal surfaces 11b and 11c of the photoconductor drum 11, the reflected light from the coated surface 11a is received by the CCD camera 13 and the metal surface The reflected light from 11b and 11c is received by the CCD camera 13 through the optical filter 17.

When the metal surfaces 11b and 11c are mirror surfaces, the reflected light does not diffusely reflect. Therefore, if the intensity of the optical filter 17 is set to be equal to or lower than the saturation level of the CCD camera 13, the surface from the normal surface having no defects can be obtained. The reflected light becomes small without variations in density, and due to this change in reflected light, the metal surface 11b,
Defects on the surface of 11c can be easily detected. FIG.
FIG. 9 is a diagram showing a fourth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, and corresponds to claim 4.
In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In FIG. 5, reference numeral 18 is a reflection mirror, and this reflection mirror 18 is arranged between the coating surface 11 a and the CCD camera 13. Further, 19 is a first reflecting mirror, 20 is a second reflecting mirror, and these mirrors 19 and 20 are metal surfaces 11b and 11b.
A pair is provided between c and the CCD camera 13. The mirrors 18, 19 and 20 reflect the reflected light from the coating surface 11a and the metal surfaces 11b and 11c into the CCD camera 13.
Are arranged at different angles so as to lead to.

In this embodiment, as shown in FIG. 5 (a), regarding the imaging of the coated surface 11a, the light receiving angle β is the metal surface 11b,
The position is set so that a minute unevenness defect on the coated surface 11a can be detected without considering the reflected light of 11c. At this time, β
The reflected light in the direction is guided to the CCD camera 13 by the reflection mirror 18, and when the setting on the coating surface 11a is completed, the positions of the photoconductor 11, the light source 12 and the CCD camera 13 are fixed.

On the other hand, it is considered that reflected light from the metal surfaces 11b and 11c is imaged at a light receiving angle δ different from that of the coated surface 11a. In this case, the reflected light in the δ direction is reflected by the two reflecting mirrors 19 and 20 as shown in FIG.
Lead to. Since the angle ω formed with the horizontal direction of the CCD camera 13 is already set by the above-mentioned setting, if the light receiving angle δ is determined, the final deflection angle ε is determined (ε = δ + ω). Further, if the incident angle of the first reflecting mirror 19 to the point B1 is ρ and the incident angle of the second reflecting mirror 20 to the point B2 is θ, the deflection angle ε can be expressed as ε = π-2 (θ + ρ). .

When the angle formed by the first and second reflection mirrors 19 and 20 is σ, σ = θ + ρ, and thus the deflection angle ε is ε = π-2σ. That is, if the light receiving angle δ is determined, the angle σ formed by the first and second reflecting mirrors 19 and 20 is also determined. By the way, in order to capture the reflected light from the coated surface 11a and the metal surfaces 11b and 11c with one CCD camera 13, the optical path length AB of the reflected light from the coated surface 11a is used.
+ BC and the optical path length AB1 of the reflected light from the metal surfaces 11b and 11c
+ B1B2 + B2C must be the same.

Therefore, the angle ψ formed by the horizontal direction of the first reflecting mirror 19 and the reflecting point B1, and further, the point D (the surface of the first and second reflecting mirrors 19 and 20) shown in FIG. By adjusting the position of the point on the line), the metal surfaces 11b, 11c
The optical path length of the reflected light from the can be made equal to the optical path length of the reflected light from the coated surface 11a. As a result, the light reflected from the surface of the photoconductor drum 11 is provided on each of the coating surface 11a and the metal surfaces 11b and 11c regardless of the position of the CCD camera 13 relative to the photoconductor drum 11. Reflecting mirrors 18, 19,
It is possible to guide the light to the CCD camera 13 so that the light reception angle is larger than the light reception angle of the specular reflection light by 20, and it is possible to inspect the presence or absence of defects on the two types of surfaces of the photosensitive drum 11.

The light receiving angle δ from the reflected light from the metal surfaces 11b and 11c may be determined by the state of the metal surfaces 11b and 11c. If the metal surfaces 11b and 11c are mirror-finished surfaces, the light quantity is reduced if the light reception intensity is close to the saturation level of the CCD camera 13 as in the third embodiment and the light reception intensity is equal to or higher than the saturation level. The optical filter may be arranged at the optimum position. Further, the defect may be imaged in a dark-field manner, as in the first embodiment, at a great distance from the regular reflection light receiving angle. Further, as in the second embodiment, the deflection plate is attached to the metal surface 11
It may be arranged at a predetermined position between b and 11c and the CCD camera 13.

FIG. 6 is a diagram showing a fifth embodiment of the surface defect inspection method according to the present invention and corresponds to claim 5. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 6, reference numerals 21 and 22 denote one-dimensional CCD cameras as additional line sensors, and the additional CCD cameras 21 and 22 are arranged so as to face the metal surfaces 11b and 11c. Therefore, in this embodiment,
Three CCDs corresponding to the coated surface 11a and the metal surfaces 11b and 11c
Cameras 13, 21, 22 are provided, and coated surface 11a and metal surface 11
Reflected lights of b and 11c are received by different CCD cameras 13, 21 and 22, respectively.

In this way, the plurality of CCD cameras 13, 21, 22
The reason for providing will be described. The metal surfaces 11b and 11c are provided at both ends of the photosensitive drum 11, and the influence of the light receiving angle is larger than that of the coated surface 11a as shown in FIG. For this reason,
When one CCD camera 13 takes an image of the entire area of the photosensitive drum 11 in the axial direction as in each of the above-described embodiments, the mechanical and structural accuracy such as the tilt of the rotation axis of the CCD camera 13 and the photosensitive drum 11 is sufficient. If not, the metal surfaces 11b at both ends,
With 11c, it is not possible to set the same light receiving angle.

For this reason, the CCD camera 13 is adjusted and arranged at an optimum position for picking up an image of a defect on the coated surface 11a, and an additional CCD camera is installed at an optimum light receiving position for picking up an image of a defect on the metal surfaces 11b and 11c. By adjusting and arranging 21 and 22, even if the mechanical and structural accuracy such as the tilt of the rotation axis of the CCD camera 13 or the photosensitive drum 11 is not sufficient, the two types of surfaces of the photosensitive drum 11 The presence or absence of defects can be inspected with high accuracy.

FIG. 7 is a diagram showing a sixth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention.
It corresponds to. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted. In FIG. 7, diffused light sources 23 and 24 are provided at both ends of the light source 12, and the diffused light sources 23 and 24 direct diffused light to the metal surfaces 11b and 11b.
It is designed to irradiate c. In addition, this diffused light source 2
3 and 24 are composed of one that guides light from a halogen lamp with an optical fiber to irradiate the diffusion surface, and one that uses a fluorescent lamp for image processing. In addition, diffused light sources 23, 24
The size of is not a line shape, but a plane shape is preferable so that it can be illuminated from any angle without directivity.

In this embodiment, the coated surface (one surface) 11a
To the metal surface (the other surface) 11b,
11c is irradiated with diffused light from diffused light sources 23 and 24. Diffuse incident light 25 from the diffuse light sources 23 and 24 is a metal surface from all angles.
Irradiation with 11b and 11c eliminates unevenness in image density due to diffused reflection, and a very uniform image can be obtained even when the metal surfaces 11b and 11c are not mirror-finished.

If the intensity of reflected light from a normal surface having no defects is set to about half of the camera saturation level, point-like defects such as scratches, protrusions, and foreign matters due to changes in density in a minute area, and in a wide area. It is possible to detect uneven defects such as stains and poor cleaning from the change in density. In this way, the influence of irregular reflection on the metal surfaces 11b and 11c can be removed, so that the presence or absence of defects on the two types of surfaces of the photosensitive drum 11 can be inspected with high accuracy.

The light receiving angle of the CCD camera 12 is the coated surface.
The optimum angle may be set to detect the defect on 11a. The reason is that the diffused light sources 23 and 24 have metal surfaces 11b,
This is because there is little influence of the light receiving angle because 11c is emitted. 7 and 8 are views showing a seventh embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention.
It corresponds to. In this embodiment, the same components as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In this embodiment, as in the first embodiment, the coating surface 11a having a long width direction is longer than the regular reflection light receiving angle at which the regular reflection light emitted from the light source 12 is reflected by the CCD camera 13. The light source 12 by arranging the CCD camera 13 so that
From the metal surface 11b, 11b that is short in the width direction
Is characterized in that the scanning laser displacement meter 30 is used to irradiate the metal surfaces 11b and 11c with laser light as shown in FIG. 8 and the defects on the metal surfaces 11b and 11c are detected based on the reflected light. Is.

First, the principle of the scanning laser displacement meter 30 is shown in FIG.
It will be described based on. The scanning laser displacement meter 30 includes a semiconductor laser 31 as a light source, a lens 32, a scanner 33, a half mirror 34, a position detecting element 35, a light receiving lens 36 and a semiconductor position detecting element 37. The projection beam from the semiconductor laser 31 is guided to the scanner 33 via the lens 32, and the scanner 33 scans the inspection target 38. The spot light reflected by this irradiation is the semiconductor position detecting element 37.
The height Z of the object to be inspected is received by the principle of triangulation.
The direction is measured.

Further, when the projection beam scanned by the scanner 33 is scanned on the inspection object 38 via the half mirror 34 and the position detecting element 35, the position detecting element 35 detects the position information in the X direction. . The position detecting element 35 is provided with pixels extending in the X direction, such as a line sensor, and is configured to detect the position in the X direction by detecting the projected beam at a predetermined position of the pixel. Also,
For the Y direction, the inspection target 38 (photosensitive drum 11) is moved in the Y direction. As a result, the three-dimensional shape of the inspection object 38 can be measured. This semiconductor position detector 37
The output in the Z direction is as shown in FIG. 9B, and since the amount indicated by the step indicates a size corresponding to the 38 steps of the inspection target, the shape data can be obtained. In addition to this, it is possible to detect a defect in the inspection target 38 based on the amount of reflected light received by the semiconductor detection element 37.

In this embodiment, this scanning laser displacement meter 30 is used.
The metal surface 11b, 11c can be irradiated with laser light by using, and the presence / absence of defects and stains on the metal surface 11b, 11c can be detected based on the reflected light. ) Can also be obtained at the same time. The method of detecting the defects on the coated surface 11a is the same as that in the first embodiment, and thus the description thereof is omitted.

FIG. 9 is a diagram showing an eighth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention.
It corresponds to. In this embodiment, the same components as those in the first and seventh embodiments are designated by the same reference numerals and the description thereof will be omitted. In this embodiment, as shown in FIG. 9A, the reflected light from the metal surfaces 11b and 11c is received by the photodiode 41 instead of the semiconductor position detecting element.

The reason is that the scanning cycle of the metal surfaces 11b and 11c by the semiconductor detection element 38 of the scanning laser displacement meter is generally slower than the scanning cycle of the one-dimensional CCD camera 13 that inspects the coated surface 11a. In the seventh embodiment, the inspection time is delayed. In the present embodiment, by using the photodiode 41 having a high response frequency as the light receiving element,
The scanning cycle of the dimensional CCD camera 13 is not delayed.

To inspect the metal surfaces 11b and 11c, the semiconductor laser 31 scans the metal surfaces 11b and 11c with laser light, and the reflected light is received by the photodiode through the lens 36. Then, when the surface of the metal surface 11b, 11c has a defect d such as a protrusion, a scratch or a stain, the light reflected from this defect is scattered and reflected from the normal surface as shown in FIG. 9 (b). Since the output is larger or smaller than the flat output that is generated, the metal surface 11
The defects of b and 11c can be detected quickly, and the effect that the inspection time can be shortened can be obtained.

[0062]

According to the first aspect of the present invention, one line sensor is arranged at a light receiving angle which is larger than the light receiving angle of specularly reflected light and in which the amount of light reflected from a surface having different properties is reversed. The reflected light from the surface of the other surface and the reflected light from the other surface are separated by a simple binarization process, and defects such as protrusions and scratches on the two types of surfaces can be easily detected from the amount of change in this signal. . As a result, one line sensor can
It is possible to simultaneously inspect for types of surface defects.

According to the second aspect of the invention, even if the line sensor is arranged at a light receiving angle larger than the regular reflection light receiving angle and exceeding the saturation level of the line sensor, the reflected light from the normal surface is transmitted. If there is a defect such as a protrusion or a scratch on the surface and the deflection direction of the reflected light changes, the deflector that is configured to transmit only this reflected light can be placed at the reflected light passing position. The light can be detected as a defect on the surface to be inspected.

According to the third aspect of the present invention, even if the line sensor is arranged at a light receiving angle larger than the regular reflection light receiving angle and exceeding the saturation level of the line sensor, the light quantity of the reflected light is reduced by the optical filter. By doing so, the presence or absence of defects on the surface of the inspection object can be inspected from the change in the light received through this filter. According to the invention described in claim 4, no matter which position the line sensor is set with respect to the inspection target, the light reflected from the surface of the inspection target is reflected by the reflection mirrors provided for each surface having different properties. It is possible to guide the light to the line sensor so that the light receiving angle is larger than the light receiving angle of the specular reflection light, and it is possible to inspect whether there are defects on the two types of surfaces to be inspected.

According to the fifth aspect of the present invention, even if the mechanical and structural accuracy of the line sensor or the axis of the inspection target such as tilting is not sufficient, one line sensor is provided according to the surface having different properties. By providing each, the presence or absence of defects on the two types of surfaces to be inspected can be inspected with high accuracy. According to the invention of claim 6, when one surface is a metal surface, the influence of irregular reflection on the metal surface can be removed, and the presence or absence of defects on the two types of surfaces to be inspected can be inspected with high accuracy. can do.

According to the seventh aspect of the invention, one surface can be inspected by detecting the light emitted from the light source with the line sensor, and the other surface can be a scanning laser displacement meter. It is possible to carry out an inspection by using it, and as a result, it is possible to simultaneously inspect for the presence or absence of defects on two types of surfaces. In addition, since the surface with a short width in the width direction is inspected by the scanning laser displacement meter, the size of the protrusion or scratch can be measured in addition to the inspection of the presence or absence of a defect such as a protrusion or scratch on the surface. .

According to the eighth aspect of the invention, one surface can be inspected by detecting the light emitted from the light source with the line sensor, and the other surface is scanned from the laser light source. The inspection can be performed based on the laser reflected light, and as a result, the presence or absence of defects on the two types of surfaces can be inspected at the same time.

[Brief description of the drawings]

1A and 1B are diagrams showing a first embodiment of an inspection apparatus for achieving a surface defect inspection method according to the present invention, in which FIG. 1A is a top view thereof, and FIG. 1B is a side view thereof.

FIG. 2 is a diagram showing a relationship between a sensitivity (amount of received light) of a CCD camera and a light receiving angle due to surface irregularities of a coated surface and a metal surface of a photosensitive drum.

3A and 3B are diagrams showing a second embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, in which FIG. 3A is a top view thereof, and FIG. 3B is a side view thereof.

4A and 4B are diagrams showing a third embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, in which FIG. 4A is a top view thereof, and FIG. 4B is a side view thereof.

FIG. 5 is a view showing a fourth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, and FIG. 5 (a) is a side view showing how reflected light from a coated surface is received by a CCD camera. , (B) are side views showing how the reflected light from the metal surface is received by the CCD camera.

6A and 6B are views showing a fifth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, in which FIG. 6A is a top view thereof, and FIG. 6B is a side view thereof.

7A and 7B are diagrams showing a sixth embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, in which FIG. 7A is a top view thereof, and FIG.

FIG. 8 is a view showing a seventh embodiment of the inspection apparatus for achieving the surface defect inspection method according to the present invention, and is a view showing a laser beam projected / reflected on the metal surface of the photosensitive drum.

FIG. 9A is a diagram for explaining the principle of the scanning laser displacement meter of the seventh embodiment, and FIG. 9B is a diagram showing the received light amount data and Z direction displacement data.

FIG. 10 is a view showing an eighth embodiment of the inspection device for achieving the surface defect inspection method according to the present invention, and FIG. 10 (a) is a view showing a state where a laser beam from the laser light source is received by a photodiode; (B) is a figure which shows the light reception amount data of the photodiode.

11A is a diagram showing a copying mechanism for carrying out a copying process of a general copying machine, and FIG. 11B is an external view of the photosensitive drum.

[Explanation of symbols]

 11 Photoconductor drum (inspection target) 11a Coating surface (one surface) 11b, 11c Metal surface (other surface) 12 Light source 13 One-dimensional CCD camera (line sensor) 15a, 15b, 16a, 16b Polarizing plate 17 Optical mirror 18 Reflection mirror 19 First reflection mirror 20 Second reflection mirror 21, 22 1-dimensional CCD camera (line sensor) 23, 24 Diffuse light source 30 Scanning laser displacement meter

Claims (8)

[Claims] 1. A test object having two kinds of surfaces having different properties is uniformly irradiated with light from a light source, and reflected light from the surface of the test object is received by a line sensor and received by the line sensor. A surface defect inspection method for detecting a defect of an inspection object based on reflected light, wherein when the inspection object is irradiated with light from the light source, the regular reflection light is reflected by the line sensor more than the regular reflection light receiving angle. One line sensor is arranged at a light receiving angle at which the amount of light reflected from a large surface having different properties is reversed, and a defect to be inspected is detected based on the reflected light received by the line sensor. Characteristic surface defect inspection method. 2. A light source uniformly irradiates an inspection object having two types of surfaces having different properties, and the reflected light from the surface of the inspection object is received by the line sensor and received by the line sensor. A surface defect inspection method for detecting a defect of an inspection object based on reflected light, wherein when the inspection object is irradiated with light from the light source, the regular reflection light is reflected by the line sensor more than the regular reflection light receiving angle. One line sensor is arranged so that the light receiving angle is large, and a polarizing plate is arranged between the surface having a large amount of reflected light and the light source among the two kinds of surfaces and between the surface and the line sensor. A surface defect inspection method, characterized in that reflected light received by the line sensor is detected as a defect of an inspection target. 3. An inspection object having two types of surfaces having different properties is uniformly irradiated with light from a light source, and reflected light from the surface of the inspection object is received by a line sensor and received by the line sensor. A surface defect inspection method for detecting a defect of an inspection object based on reflected light, wherein when the inspection object is irradiated with light from the light source, the regular reflection light is reflected by the line sensor more than the regular reflection light receiving angle. One line sensor is arranged so as to have a large light-receiving angle, and an optical filter for reducing the light amount is arranged between the surface of the two types of surfaces having a large amount of reflected light and the line sensor. A surface defect inspection method characterized in that a defect of an inspection target is detected based on reflected light received by a sensor. 4. A reflection mirror is arranged between the two types of surfaces having different properties and the line sensor at different angles so as to guide the reflected light reflected from the inspection object to the line sensor. The surface defect inspection method according to claim 1. 5. A light source uniformly irradiates an inspection target having two types of surfaces having different properties, and the light reflected from the surface of the inspection target is received by the line sensor and received by the line sensor. A surface defect inspection method for detecting a defect of an inspection target based on reflected light, wherein when the inspection target is irradiated with light from the line sensor, the regular reflection light is received from the regular reflection light receiving angle reflected by the line sensor. The surface defect inspection method is characterized in that line sensors are provided one by one according to surfaces having different properties, and defects of an inspection object are detected based on reflected light received by the line sensor. . 6. The surface defect inspection method according to claim 1, wherein one surface having different properties is irradiated with diffused light. 7. A surface defect inspection method for irradiating an inspection object having two types of surfaces having different properties with light, and detecting a defect of the inspection object based on the reflected light from the surface of the inspection object. When the width direction length of one surface is different,
The line sensor is arranged so that the regular reflected light has a light receiving angle larger than the regular reflected light receiving angle reflected by the line sensor, and a defect on one surface is detected based on the reflected light received by the line sensor, A surface defect inspection method characterized by detecting a defect on the other surface using a scanning laser displacement meter when the widthwise length of the other surface having different properties is short. 8. A surface defect inspection method for irradiating an inspection object having two types of surfaces having different properties with light, and detecting a defect of the inspection object based on the reflected light from the surface of the inspection object. If the width direction length of one of the different surfaces is long, arrange the line sensor so that the regular reflection light has a larger light receiving angle than the regular reflection light reception angle reflected by the line sensor. A defect on one surface is detected based on the received reflected light, and when the length in the width direction of the other surface having different properties is short, the surface is scanned with a laser light using a laser light source, and this laser light is used. A surface defect inspection method, characterized in that a defect on the other surface is detected based on the reflected light of.