JP2011107074A - Method and device for inspecting surface of blade for electrophotography device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently detect gentle irregularities, extremely minute scratches and unevenness, and a minute contrast on the surface of a blade for an electrophotography device. <P>SOLUTION: A method of inspecting the surface of a blade for an electrophotography device includes: a first step of lighting the surface of a blade 1 for an electrophotography device, carrying the blade 1 in a direction orthogonal to the lighting, and imaging the surface by a line sensor 11 where a plurality of pixels are disposed; a second step of performing, for each pixel, addition processing for adding each image information signal output by each pixel in a prescribed region comprising a plurality of pixels 4 continuous to one pixel 4 to an image information signal output by the pixel 4 of the line sensor 11 as an addition image information signal in one pixel 4 for image processing; and a third step of determining a surface state of the blade 1, based on the image processing results. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a blade surface inspection method and a surface inspection apparatus used in an electrophotographic apparatus.

  Conventionally, in the appearance inspection of parts for an electrophotographic apparatus, the surface to be inspected is imaged by an image sensor, and image processing such as noise reduction and contour enhancement is performed on the obtained image data. As a result, a technique of extracting defective portions in image data has been widely performed. In the inspection of the electrophotographic apparatus blade, the same method as described above is basically used. The camera used at this time is configured, for example, as shown in FIG. That is, an image of the surface state of the blade 101 is captured by a line sensor in which a plurality of pixels 104 are arranged in a line in the camera 102 through a lens 103 attached to the camera 102. Then, the line sensor outputs an image information signal S1 corresponding to the number of pixels 104, and the plurality of image information signals S1 are sent to the image processing means 5, processed by the image processing unit 105, and then subjected to inspection. The surface state of a certain blade 101 is displayed and can be determined (see, for example, Patent Document 1).

  In the above-described conventional method, the image processing unit 105 performs processing based on the individual image information signal S1 corresponding to each of the plurality of pixels 104 constituting the line sensor. For this reason, for example, when one pixel 104 can detect the lightness of 256 gradations, the lightness gradation detection capability of the line sensor itself is 256 gradations of each lightness gradation of the pixel 104. It is not possible to detect a more subtle contrast that exceeds. Therefore, no matter what image processing the image processing unit 105 performs, the basic inspection capability is limited to within the range of 256 gradations of each pixel 104 and detection is performed.

  When considering using an appearance inspection machine instead of visual inspection, it is said that the lightness gradation by visual inspection is about 150 gradations for a point-like inspection object, so in order to inspect a normal inspection object For this, 256 gradations are sufficient. However, in a visual inspection for a difficult-to-recognize inspection object such as a low-contrast inspection object having a wide spread, a cone corresponding to a pixel accumulates visual information among a plurality of cells with the naked eye, resulting in a maximum of 1600 floors. It can be identified by key. Due to the difference between the visual ability and the inspection machine performance, the subtle brightness gradation existing on the surface of the blade to be inspected in the visual inspection machine is lacking in contrast even if the shape is captured in the same way as the visual inspection. It may be difficult to clearly distinguish the appearance defects. Accordingly, there is a problem in that unevenness having an extremely gentle inclination cannot be detected in a product in which extremely small unevenness is provided on the entire surface of the blade.

JP 7-239304 A

  In view of the above situation, the present invention makes it possible to expand the lightness gradation of each pixel of the line sensor. As a result, the present invention is for an electrophotographic apparatus capable of efficiently detecting subtle contrasts such as unevenness that is apt to be buried in extremely minute irregularities on the surface of a blade for an electrophotographic apparatus and that has an extremely gentle inclination. It is an object of the present invention to provide a surface inspection method and a surface inspection apparatus for a blade.

  In order to achieve the above-described object, a method for inspecting a surface of a blade for an electrophotographic apparatus according to the present invention illuminates the surface of the blade for an electrophotographic apparatus and conveys the blade in a direction orthogonal to the illumination. The image information signal output from each pixel in a predetermined region composed of a plurality of pixels continuous with the one pixel is output to the first step of imaging the surface by the first step and the image information signal output from one pixel of the line sensor. A second step of performing image processing by performing addition processing for each pixel, and a third step of determining the surface state of the blade based on the result of the image processing, Have.

  In the first step for imaging, both the depression angle formed by the optical axis of the imaging unit having the line sensor and the irradiation angle formed by the optical axis of illumination light by the illuminating unit with respect to the surface of the blade are 10 It is desirable that the angle be between 30 ° and 30 °.

  Similarly, in the first step, the illumination light applied to the blade is subjected to slit-shaped masking means covering the illumination means main body, or to the inspection object after diffusion is limited by a light shielding plate or the like in the space near the blade. It is desirable to be irradiated.

  Further, according to the present invention, a conveying unit that conveys a blade for an electrophotographic apparatus in a direction orthogonal to the illumination, an illuminating unit that illuminates the surface of the blade, and an image that images the surface while conveying the blade by a line sensor Means. According to the present invention, the image information signal output from one pixel of the line sensor is added to each image information signal output from each pixel in a predetermined region including a plurality of pixels continuous with the one pixel. Image processing means for performing addition processing for each pixel as an added image information signal in one pixel, and determination means for determining the surface state of the blade based on the result of the image processing means.

  Further, in the present invention, the depression angle formed by the optical axis of the imaging unit having the line sensor and the irradiation angle formed by the optical axis of the illumination light by the illumination unit are both 10 ° or more and 30 ° with respect to the surface of the blade. Desirably, the following is set, and the illumination light applied to the blade has slit-shaped masking means covering the illumination means body or means for limiting diffusion in the space near the blade. However, it is desirable to irradiate the inspection object under the influence.

  According to the present invention, an image in which the contrast on the surface of the blade is emphasized can be obtained, and unevenness with a gentle inclination on the surface of the blade can be detected.

It is the schematic which shows the camera in the surface inspection method which integrates the image information signal from each pixel. It is the schematic which shows the camera arrangement | positioning for conveying a blade and imaging. It is a schematic diagram which shows the support mechanism which can adjust the distance of the camera with respect to a braid | blade, and the angle of an optical axis. It is a schematic diagram for demonstrating the definition of the unevenness | corrugation with a gentle inclination. It is a schematic diagram for demonstrating the difference between the image by a line sensor, and the image by an area sensor. It is a schematic diagram for demonstrating the control method of how to apply light. It is the schematic which shows the shape of a braid | blade. It is a schematic diagram for demonstrating the camera used with the conventional surface inspection method.

  Embodiments of the present invention will be described below with reference to the drawings.

  The blade surface inspection method for an electrophotographic apparatus according to the present invention illuminates the surface of the electrophotographic apparatus blade 1 shown in FIG. 1 and transports the blade 1 in a direction orthogonal to the illumination, while 4 has a first step of imaging the surface by the line sensor 11 in which 4 is arranged. Further, in this method, each image information signal output from each pixel in a predetermined region including a plurality of pixels 4 continuous with the one pixel 4 is output to the image information signal output from one pixel 4 of the line sensor 11. A second step of adding. In this second step, the image information signal from one pixel 4 is added to each image information signal from each pixel 4 in a predetermined area to obtain an added image information signal in one pixel 4 for each pixel. By doing, image processing. The method also includes a third step of determining the surface state of the blade 1 based on the result of image processing.

  In the present invention, for example, when the lightness gradation of one pixel of the line sensor is 256, an image information signal output from one pixel is handled as any one of 256 values. Now, each image information signal output from each pixel in a predetermined area including five pixels including this one pixel and continuing to this one pixel is added to the image information signal output from one pixel. Think. By this addition processing, the image information signal output by one pixel is handled as any value of 256 × 5 = 1280. That is, it is possible to handle the brightness gradation of one pixel as having been increased five times.

  Then, by performing such addition processing for each of the five pixels in the predetermined area, the image data processed is used as one data unit in the predetermined area, and the image data is processed in another predetermined area adjacent to the predetermined area. Compare with other data units. Thereby, a fine state on the surface of the blade is determined.

  The surface inspection apparatus employing the above-described method includes a transport mechanism that transports the electrophotographic blade 1 in a direction orthogonal to the illumination, and an illumination unit that illuminates the surface of the blade 1. . In addition, this apparatus includes an imaging unit as an imaging unit that images the surface with a line sensor 11 while the blade 1 is conveyed by a blade conveyance mechanism. Further, in this apparatus, each image information signal output from each pixel 4 in a predetermined region including a plurality of pixels 4 continuous with the one pixel 4 is output to the image information signal output from one pixel 4 of the line sensor 11. 1 is provided (see FIG. 1). The image processing unit 5 performs an addition process for each pixel by adding each image information signal from each pixel 4 in a predetermined area to the image information signal from one pixel 4 to obtain an added image information signal in one pixel 4. To do. The apparatus also includes a determination unit as a determination unit that determines the surface state of the blade 1 based on the result of the image processing unit 5.

  A camera 2 having a line sensor 11 is used as the imaging unit (FIG. 1). Compared with the area sensor, the line sensor cannot obtain an image as a surface unless the object to be imaged is moved while moving at a constant speed, but is advantageous in increasing the resolution because the number of pixels is relatively large. In addition, since the line sensor does not have a charge transfer portion between pixels, the line sensor has an advantage that it has a high aperture ratio and is suitable for capturing a delicate contrast. Further, assuming that the blade 1 being transported is imaged in the direction of arrow A as shown in FIG. 5A, the data B1, B2, and B3 that can be acquired at once by the line sensor are shown in FIG. Consider that data comparison is performed in a direction orthogonal to the arrangement direction of a plurality of pixels as indicated by an arrow a. At this time, since data obtained by the same pixel is compared, there is no pixel variation. This is also an advantage over the area sensor 12 shown in FIG. Since there is usually about 3% of pixel variation, a contrast difference within 3% is not allowed to be treated as a significant difference in consideration of this pixel variation. When the lightness gradation that can be detected by each pixel is 256 gradations, the variation of pixels that cannot be regarded as a significant difference reaches 7 gradations.

  As will be described later, since the image sensor signals of a plurality of pixels are integrated with respect to the output of the line sensor, the presence itself can be detected even if the structure is considerably smaller than the size of the pixels. Therefore, if the resolution is not particular or if a plurality of cameras are arranged, the line sensor may have 3000 pixels or more. As shown in FIGS. 2A and 2B, the direction in which the plurality of cameras are arranged is preferably aligned with the direction perpendicular to the longitudinal direction of the blade 1 and the optical axis of the lens of the camera 2. At this time, the focal length of the lens attached to the camera 2 is determined by how many cameras the blade 1 is inspected, but if the entire blade 1 is set within the field of view of the lens, the focal length of the surface inspection apparatus is set. This is preferable because the configuration is simplified.

  As for the illumination applied to the blade 1, it is preferable to prevent the light from diffusing through the slit. Alternatively, a light shielding plate may be provided in the vicinity of the blade so that the light is not irradiated onto the blade from different angles at the same time. By doing so, light from a light source having a spread close to the blade 1 is irradiated from many directions, and light is uniformly applied to extremely gentle irregularities to eliminate shadows and prevent detection from becoming difficult. As shown in FIG. 6 (a), if the light from the light source hits the dent as it is, it becomes difficult to make a shadow due to various scattered light. On the other hand, as shown in FIG. If most of the light is cut so that the parallel light strikes the dents, shadows can be easily made and the dents can be seen more easily.

  The line sensor 11 may be a monochrome sensor, but a color sensor may be arranged to process signals of three colors separately. However, some color line sensors have three line sensors arranged simply in parallel. In this case, an optical path difference from the subject (blade) occurs between the individual line sensors. For this reason, in this case, it is necessary to pay attention to whether the defocus of the image sensor of any color does not exceed an allowable level.

  The blade conveyance speed by the conveyance mechanism needs to be set so that the image acquired by the line sensor 11 has sufficient resolution in the conveyance direction of the blade 1. For example, it is desirable that the speed is about 1 cm / sec or more and 20 cm / sec or less. If the capture frequency of the image information signal is 2000 Hz, even if the conveyance speed is 20 cm / sec, the image information signal is expressed with a fineness of 100 μm per data in the blade conveyance direction. It is more desirable if the conveyance speed is 10 cm / sec or less, and the fineness per data in the conveyance direction when the conveyance speed is 1 cm / sec is 5 μm.

  The illumination unit may be a light source that can obtain a uniform amount of light with respect to the longitudinal direction of the blade 1. For example, a line light source 10 disposed substantially parallel to the longitudinal direction of the blade is used.

  In order to obtain an image effective for determining the surface state of the blade 1, the line sensor 11 includes a distance from the surface of the blade 1 and a depression angle overlooking the surface of the blade 1, for example, as shown in FIG. 3. It is desirable to have a structure that is supported by a support mechanism that can be freely adjusted. The support mechanism includes a rotation stage 16 that rotatably supports the camera 2. The support mechanism also supports a vertical guide 15 that slidably supports the rotary stage 16 in a vertical direction orthogonal to the longitudinal direction of the blade 1, and can slide the vertical guide 15 in a horizontal direction orthogonal to the longitudinal direction of the blade 1. And a horizontal guide 14 to be supported.

  In addition, the depression angle θ1 formed by the optical axis of the lens 3 of the camera 2 having the line sensor 11 and the irradiation angle θ2 formed by the optical axis of the illumination light from the illuminating unit with respect to the tangential plane contacting the surface of the blade 1 (FIG. 2 ( Both a)) are preferably set to 30 ° or less. By making the angle of the illumination light by the illumination unit shallow, and viewing the almost totally reflected light with a line sensor, the reflected light that does not transmit or diffuse can be captured efficiently. However, if the angle is too shallow, the point at which the reflected light is brightest becomes difficult to see from the camera, or the camera focus is difficult to focus on the blade surface. For this reason, it is desirable that the lower limit of the angle be 10 °. As described above, the angles θ1 and θ2 are both set to 10 ° to 30 °. In this way, the data for the entire blade is continuously taken in by the line sensor 11 when the blade 1 is conveyed, and is sent to the image processing unit 5.

  The image processing unit 5 adds each image information signal output from each pixel 4 in a predetermined region including a plurality of pixels 4 continuous with the one pixel 4 to the image information signal output from one pixel 4. The image processing unit 5 performs an addition process for each pixel by adding each image information signal from each pixel 4 in a predetermined area to the image information signal from one pixel 4 to obtain an added image information signal in one pixel 4. To perform image processing. The result of such image processing is used for determining the surface state as one data unit in a predetermined area.

As a method of addition processing, for example, the following three methods are conceivable.
(I) Addition processing is performed only in the pixel array direction of the line sensor 11.
(Ii) Addition processing is performed only in the direction orthogonal to the pixel arrangement direction of the line sensor 11. At this time, the data to be added is captured while the blade 1 is transported, so that apparently the pixels are spatially arranged in a direction orthogonal to the pixel arrangement direction of the line sensor 11. Therefore, the addition of each image information signal by these pixels actually means adding the time series information signals by the same pixel.
(Iii) Addition processing is once added only in the direction orthogonal to the pixel arrangement direction of the line sensor 11, and then addition processing is added to the added image information data in the pixel arrangement direction.

  If such an addition process is performed, it is possible to provide the gradation recorded by one pixel × the number of pixels to be added in the data recorded as one pixel. For example, when 10 pixels are added, one pixel can be handled with 256 × 10 = 2560 gradations, and when 50 pixels are added, one pixel is 256 (gradation) × 50. (Pixel) = 12800 gradations can be handled. In addition to obtaining a gradation that is twice the number of accumulated pixels of 256 gradations in the output of a general camera, pixel variations in a general camera are reduced by the central limit theorem on the accumulated data, and 1 / √ (number of added pixels). Specifically, 3% when addition processing is not performed is 0.4% on the integrated data of 50 pixels. The state of the flow of the image information signal at this time is schematically shown in FIG. In FIG. 1, integration for three pixels is performed. The 256 gradation S1 signals are integrated, so that an even more gradation S2 signal is output for determination.

  Regarding the data addition method, it is generally preferable to use the addition process (i) in order to improve the gradation. However, if there is an elongated defect on the surface of the blade 1 along the pixel arrangement direction, the addition process of (i) for this defect will be adjusted in the pixel arrangement direction, making it difficult to understand the defect. There is. In order to particularly emphasize the defects, it is effective to use the addition process (iii). Since the data addition calculation process is performed once in the longitudinal direction of the elongated defect, the accumulated light amount difference between the part having no defect and the part having the defect becomes extremely large. After that, by further performing addition calculation processing in the pixel array direction, the contrast of the defective portion is remarkably increased as compared with the original image data.

  In addition, it is preferable to use the addition process (ii) for a minute defect that easily disappears due to the above-described addition calculation process between pixels. By using the addition process of (ii), even if it is a minute defect, the contrast with the peripheral part is increased by the addition calculation process, and the addition process is not performed until the data between adjacent pixels is added. Even if it is a simple defect, there is an effect that it is not buried.

  The difference between the data of the predetermined area R1 obtained as described above and the data of the predetermined area R2 adjacent to the predetermined area R1 and subjected to the same addition operation processing is calculated for all image areas, and originally Is sent to the determination unit together with the added data.

  In the determination unit, if the difference data calculated for the entire image area has a systematic inclination, the leveling process is performed as necessary, and only a sudden change and a change with a large difference in height are left. Subsequently, in the image subjected to such correction, all the predetermined areas exceeding the predetermined upper limit value and lower limit value are extracted, and any of the areas of the extracted individual areas is extracted. It is determined whether there is something exceeding the amount specified in. When one or more objects exceeding the arbitrarily defined amount exist, it is determined that the region is a defective portion on the surface of the blade. In this way, the acquired image data is subjected to addition calculation processing and leveling processing, and only the intended type of defects are effectively emphasized, and then used to determine the fine state on the blade surface. .

  As described above, in the surface inspection method according to the embodiment, each pixel 4 in a predetermined region including a plurality of pixels 4 continuous with the one pixel 4 is included in the image information signal output from one pixel 4 of the line sensor 11. Each image information signal to be output is added. Then, the image information signal from one pixel 4 is added to each image information signal from each pixel 4 in a predetermined region to obtain an added image information signal in one pixel 4 for each pixel. To process. By using a surface inspection apparatus that realizes such a surface inspection method, it is possible to efficiently detect a surface defect of an electrophotographic blade that includes unevenness having a delicate contrast and a gentle slope as a defect portion.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and the effect of invention is clarified more, this invention is not restrict | limited to a following example.

A blade 1 for an electrophotographic apparatus having a plurality of defect portions including at least unevenness having a gentle inclination is prepared as a measurement sample. An elastic blade is used as a sample for inspection this time. As shown in FIG. 7, the blade 1 is mainly composed of a flat plate-like elastic blade body 25 and a sheet metal 24 for fixing it. The blade body is translucent, the flat elastic body portion has a width of 10 mm and a length of 215 mm, and the metal sheet metal bonded to the end of the elastic body along the longitudinal direction has a width of 6 mm and a total length of 10 mm. 250 mm. Specific item names of the unevenness are classified as “dent”, “distortion”, and “back-up”. When viewed from the inspection surface of the blade, each defect has the following characteristics.
“Dent”: A spherical dimple made in a position that does not reach the inside or end of the blade.
“Distortion”: A depression similar to a “dent”, which occurs at the blade end, and therefore the end shape is distorted.
Contrary to “back up” and “dent”, it is a shape that is pushed up from the back and gently rises to the top.

  None of these irregularities with a gentle inclination could be identified by the conventional automatic visual inspection method.

  Here, the present invention has been described with reference to the blade 1 having an elastic body part for an electrophotographic apparatus, but the constituent elements of the present invention are appropriately adjusted in accordance with the width, length, and variety of materials of the blade. It goes without saying that the same measurement is possible with other blades.

  With respect to these irregularities, it is very difficult to discriminate because the inclination, which is the amount of displacement, is particularly gentle. These displacement amounts are as follows.

As shown in FIG. 4A to FIG. 4D, the maximum value of the length b in the AB cross section and the CD cross section from one end to the other end in the longitudinal direction of the defective portions D1 and D2 is set to bmax ( Width), when the maximum value in the height difference t in the depth direction perpendicular to the longitudinal direction is tmax,
tmax / bmax ≦ 0.15
It refers to the unevenness that satisfies.

As a surface inspection apparatus having the illumination unit, the imaging unit, the image processing unit, and the determination unit described above, Super 5000K manufactured by Technos Co., Ltd. was used. The illumination light is available with or without a slit masking / shielding effect. The blade 1 is held by a transport mechanism, and the surface is imaged while being transported at a speed of 5 cm / sec, and data of the entire blade is acquired. The camera 2 has a line sensor 11 of 5120 pixels, is arranged at a distance of 450 mm from the surface of the blade 1, and the lens 3 attached to the camera 2 is FA50 mm, F1.4 manufactured by Pentax. Using. At this time, the field of view of the lens 3 is about 315 mm with respect to the longitudinal direction of the blade 1, and the portion of the elastic body of the blade 1 is captured by about 3500 pixels. Therefore, the length expressed by one pixel 4 in the longitudinal direction of the blade 1 is 61 μm. The data acquisition frequency of the camera 2 is 2 kHz, and a fluorescent lamp driven by a high frequency power source is used as the line light source 10. The frequency of the fluorescent lamp is 20 kHz, and the ripple is 0.4%. The acquired image data was subjected to the following addition process, and image determination was performed.
(Addition process 1) The number of added pixels is set to 30 using the addition process (i) described above.
(Addition process 2) The addition pixel number is set to 50 by using the above-described addition process (ii).
(Addition process 3) The addition process of (iii) mentioned above is used, and it is set as the addition pixel number 20 in the direction orthogonal to a pixel arrangement direction, and the addition pixel number 30 in a pixel arrangement direction.
(Addition Process 4) Using the above-described addition process (iii), the number of added pixels is 30 in the direction orthogonal to the pixel array direction and the number of added pixels is 60 in the pixel array direction.

  The results are shown in Table 1. Items that can be detected in the original image that has not been subjected to addition processing or in addition processing 1 to 4 are indicated by “◯”. When it cannot be detected, it is indicated by “x”. The original image is a comparative example, and an example in which addition processes 1 to 4 are performed is an example. In the original image, if the surface state cannot be determined at least at the light amount level, a defective portion can be determined by performing an appropriate addition process among the four types of addition processes.

  As can be seen from the above examples, by using the surface inspection method and the surface inspection apparatus, it was possible to efficiently detect unevenness with a delicate contrast and a gentle inclination on the surface of the electrophotographic blade. .

  In the present embodiment, a translucent elastic blade has been described as an example as the blade 1 for an electrophotographic apparatus. However, the present invention may be suitably used for blades of other materials. .

DESCRIPTION OF SYMBOLS 1 Blade 2 Camera 3 Lens 4 Pixel 5 Image processing part 10 Line light source 11 Line sensor 12 Blade conveyance direction 14 Horizontal guide 15 Vertical guide 16 Rotating stage 17 Blade conveyance mechanism θ1 Depression angle θ2 Irradiation angle 18 Defect defective part 19 Non-parallel scattered light 20 Parallel scattered light 21 Slit 22 Light shielding plate 23 Shadow portion 24 Sheet metal 25 Blade body 101 Blade 102 Camera 103 Lens 104 Pixel 105 Image processing portion A Order of image capture B Direction in which dents and distortion are formed C Back-up is formed Direction D1 dent defect occurrence part D2 convex defect occurrence part

Claims (10)

A first step of illuminating the surface of a flat blade for an electrophotographic apparatus, and imaging the surface by a line sensor in which a plurality of pixels are arranged while conveying the blade in a direction orthogonal to the illumination;
The image information signal output from one pixel of the line sensor is added to each image information signal output from each pixel in a predetermined area composed of a plurality of pixels continuous with the one pixel, and added in the one pixel. A second step of performing image processing by performing addition processing for each pixel as an image information signal;
A third step of determining a surface state of the blade based on the image processed result;
A method for inspecting the surface of a blade for an electrophotographic apparatus.   2. The surface inspection method for a blade for an electrophotographic apparatus according to claim 1, wherein, in the second step, the addition process is performed in the predetermined region in the pixel arrangement direction.   The said addition process is performed in the said 2nd step in the said predetermined area | region of the direction orthogonal to the arrangement direction of the said pixel in which the said pixel is arranged spatially with conveyance of the said blade. Method for inspecting the surface of a blade for an electrophotographic apparatus.   In the second step, after the addition process is performed in the predetermined region in a direction orthogonal to the pixel arrangement direction, the pixels appear to be spatially arranged as the blade is conveyed, The method for inspecting a surface of a blade for an electrophotographic apparatus according to claim 1, wherein the addition process is performed in the other predetermined region in the arrangement direction.   In the first step, the depression angle formed by the optical axis of the imaging unit having the line sensor and the irradiation angle formed by the optical axis of the illumination light by the illumination unit are both 10 ° or more and 30 ° with respect to the surface of the blade. The blade surface inspection method for an electrophotographic apparatus according to any one of claims 1 to 4, which is as follows.   In the first step, the illumination light to be irradiated to the blade is irradiated after the main body of the illumination unit is covered with a slit-like masking unit or after diffusion is limited by a shielding plate in the vicinity of the blade. The blade surface inspection method for an electrophotographic apparatus according to any one of claims 1 to 5, wherein:   The blade surface inspection method for an electrophotographic apparatus according to any one of claims 1 to 6, wherein, in the first step, the blade is transported at a speed of 1 cm / sec or more and 20 cm / sec or less. Illumination means for illuminating the surface of a blade for an electrophotographic apparatus;
Conveying means for conveying the blade in a direction orthogonal to the illumination means;
Imaging means for imaging the surface by a line sensor in which a plurality of pixels are arranged while conveying the blade;
The image information signal output from one pixel of the line sensor is added to each image information signal output from each pixel in a predetermined area composed of a plurality of pixels continuous with the one pixel, and added in the one pixel. Image processing means for performing addition processing for each pixel as an image information signal;
A determination unit that determines a surface state of the blade based on a result of the image processing unit;
A surface inspection apparatus for a blade for an electrophotographic apparatus.   The said surface inspection apparatus WHEREIN: The said illumination means has a slit-shaped masking means which covered the main body of the said illumination means, or a means to restrict | limit diffusion in the vicinity of the said braid | blade, The characterized by the above-mentioned. Blade surface inspection device for electrophotographic equipment.   10. The blade surface inspection apparatus for an electrophotographic apparatus according to claim 8, wherein the conveying means conveys the blade at a speed of 1 cm / sec or more and 20 cm / sec or less.

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