JP4135919B2 - Conductive roller surface discrimination method - Google Patents

Description

  The present invention relates to a method for determining the surface of a conductive roller for determining whether the surface state of the manufactured conductive roller is good or bad.

  Recently, in an electrophotographic apparatus such as an electronic printer apparatus or an electronic facsimile apparatus, it is necessary to apply toner uniformly on the surface of the photosensitive drum in order to improve image quality. For this reason, the photosensitive surface of the developing roller or the photosensitive drum is charged. The quality of a conductive roller such as a charging roller is attracting attention. That is, if there is a defective part on the surface of these conductive rollers, the image quality of the copy transferred from the photosensitive drum is directly affected by the defective part, so it is necessary to ensure the quality of the surface state of the conductive roller quite strictly. Is done.

  For this reason, the manufacturing side of the conductive roller strictly inspects the surface state of the manufactured conductive roller, and the electrophotographic apparatus manufacturing side of the delivery destination also performs a strict acceptance inspection.

  In the inspection of the conductive roller, an appearance inspection in which the conductive roller is visually observed, and a measurement of an outer diameter and a variation thereof by a measuring device are performed. However, visual inspection alone is not sufficient, and it is necessary to inspect the surface state of the conductive roller over the entire outer peripheral surface. For this reason, a contact inspection in which an inspection probe with a sharp tip is brought into contact with the outer peripheral surface has been proposed. In this case, a non-defective conductive roller has undergone a contact inspection, resulting in a rough surface, resulting in a defective product. Therefore, practical use was difficult.

  Therefore, Patent Document 1 proposes a surface inspection method for a conductive roller that can inspect the surface state over the entire outer peripheral surface without roughening the surface state.

  In this inspection method, the manufactured conductive roller is brought into rolling contact with an inspection roller whose outer peripheral surface is finished with a predetermined roundness, and the conductive roller is driven to be driven by rotation of the inspection roller. Light was irradiated, and whether or not the surface state of the conductive roller was acceptable was determined based on the light leakage from the rolling contact portion.

  In other words, when the rolling contact part of the inspection roller and the conductive roller is photographed with a CCD camera and light is not leaked from the image displayed on the image display device, it is a non-defective product, and light is leaking even a little. It was judged as a defective product.

JP 2003-149168 A

  However, in such an inspection method, since the inspector pays attention to the image displayed on the image display device and judges it, it is left to the inspector to judge whether the product is non-defective or defective based on the amount of light leakage. Judgment criteria became ambiguous and accurate pass / fail judgment could not be made. In addition, due to the fatigue of the inspector, inspection for a long time was not possible, and the inspection quantity was limited.

  Therefore, the present invention rolls the manufactured conductive roller onto the inspection roller whose outer peripheral surface is finished with a predetermined roundness, and drives the conductive roller to be driven by the rotation of the inspection roller. In the method for discriminating the surface state of the conductive roller by irradiating light on the surface and judging whether or not the surface state of the conductive roller is based on the light leakage from the rolling contact portion, the light leakage is quantitatively analyzed by digital image processing. A surface that can accurately determine the quality of the conductive roller by grasping the amount of leakage and determining the quality from this amount of light leakage, and can significantly increase the number of inspections limited by the inspector's image gaze. The purpose is to provide a discrimination method.

In order to solve the above-mentioned problems and achieve the object, the surface determination method for a conductive roller according to the present invention is as follows. According to the first aspect, the manufactured conductive roller has an outer peripheral surface having a predetermined roundness. A first step of rolling contact on the finished inspection roller, a second step of rotating the inspection roller and drivingly driving the conductive roller in contact with the inspection roller, the rotating inspection roller and the conductive roller Whether or not the surface state of the conductive roller is determined based on the third step of irradiating the rolling contact portion of the conductive roller with light and the occurrence of light leakage from the rolling contact portion of the inspection roller and conductive roller. In the method for discriminating the surface of the conductive roller comprising the fourth step of judging, the fourth step is a step of photographing the rolling contact portion of the inspection roller and the conductive roller so that the light leakage portion can be photographed. 1 sub-process and this first sub-process A second sub-process for measuring the height and width of the light leakage portion from the photographed image, and the surface of the conductive roller based on the height and width information measured in the second sub-process. A third sub-process for determining whether or not the state is acceptable , wherein the third sub-process is a product in which the product of the width of the light leakage portion and the height of the light leakage portion is equal to or less than a first predetermined value. The width of the light leaking portion is equal to or greater than a second predetermined value from among a first determination process that is determined to be possible and other than possible is determined to be impossible, and from the first determination process that is determined to be impossible by the first determination process. In addition, when the height of the light leakage part is equal to or less than the third predetermined value, it is determined as possible, and a second determination process for determining other than possible is impossible, and this second determination process determines that it is impossible. The width is less than or equal to the second predetermined value and the height is A third determination process for further determining that a value that is less than or equal to a fourth predetermined value that is smaller than a predetermined value is acceptable, and among those that are determined to be acceptable by the third determination process, what value of the ratio is the fifth predetermined value or more, characterized in that Ru and a fourth determination process of determining improper.

  According to a second aspect of the present invention, there is provided a method for discriminating the surface of the conductive roller. According to the second aspect of the present invention, in the fourth step, the surface state of the conductive roller is excellent when no light leakage occurs. In addition, even if the light leakage occurs, the surface condition of the conductive roller is also determined to be good even if it is determined to be acceptable in the third sub-process.

  According to a third aspect of the present invention, there is provided a method for determining a surface of a conductive roller, wherein in the first sub-step, the digital image information of the rolling contact portion is obtained by the photographing. .

  According to a fourth aspect of the present invention, there is provided a method for discriminating the surface of a conductive roller from the number of pixels corresponding to the height and width in the digital image information in the second sub-step. And width information are defined respectively.

According to a fifth aspect of the present invention, in the first determination process, the first predetermined value is preferably an actually measured value of the light leakage portion. In the second determination process, the second predetermined value is preferably a value corresponding to about 30 mm as an actual measurement value of the light leakage portion, and The predetermined value is preferably a value corresponding to about 1.6 mm as an actual measurement value of the light leakage portion, and in the third determination process, the fourth predetermined value is preferably an actual measurement value of the light leakage portion. as a value corresponding to 1 mm, the predetermined value of the fifth characterized in that preferably about 0.2.

According to a sixth aspect of the present invention, there is provided a method for discriminating the surface of a conductive roller. According to the sixth aspect of the present invention, the traveling direction of the conductive roller and the inspection roller is directed to the light photographing unit. Thus, it is characterized by being rotated.

According to a seventh aspect of the present invention, there is provided a method for determining the surface of a conductive roller, wherein the conductive roller is a charging roller for charging a photosensitive member in an electrophotographic apparatus. .

The surface discriminating method of the conductive roller according to the present invention, according to claim 8, wherein the conductive roller, a developing roller for supplying the developer to the photosensitive surface of the photosensitive member in an electrophotographic apparatus It is characterized by being.

  According to the surface determination method of the conductive roller of the present invention, the amount of light leakage is quantitatively grasped by digital image processing of the light leakage, and the quality determination of the conductive roller is accurately performed by the quality determination processing. It is possible to provide a surface discriminating method capable of making the inspection quantity limited by the inspector's image gaze almost unlimited.

  Hereinafter, the procedure in one embodiment of the surface discrimination method of the conductive roller according to the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a front view schematically showing a discriminating apparatus for realizing the surface discriminating method of the conductive roller according to the present invention. The discriminating device includes a base 12, both side plates 14 and 16 mounted on the base 12 in a standing state at a predetermined interval, and an inspection roller 18 rotatably spanned on the both side plates 14 and 16. And. Here, the roundness and straightness of the outer peripheral surface of the inspection roller 18 are both set within a predetermined range, for example, within a range of 5 μm to 10 μm.

  In addition, recesses 20 and 22 for receiving shaft portions SH1 and SH2 provided at both ends of the conductive roller DR are formed at the upper end edges of the side plates 14 and 16, respectively. Here, the conductive roller DR is a manufactured roller that undergoes a surface condition inspection. Each of the recesses 20 and 22 has a diameter slightly larger than the diameter of the corresponding shaft portions SH1 and SH2, and the outer peripheral surface of the conductive roller DR is in a state where the corresponding shaft portions SH1 and SH2 are loosely fitted. It is formed so as to have a depth sufficient for rolling contact with the outer peripheral surface of the inspection roller 18 from above.

  In this discrimination device, since the conductive roller DR is in rolling contact with the inspection roller 18, the conductive roller DR that is in rolling contact with the rotational driving of the inspection roller 18 is also rotated. In this state, if there are fine dents, scratches, or protrusions on the outer peripheral surface of the conductive roller DR, a gap is generated in the rolling contact portion 19 between the inspection roller 18 and the conductive roller DR.

  FIG. 2 is a side view schematically showing a discriminating apparatus for realizing the surface discriminating method of the conductive roller according to the present invention. The discriminating apparatus includes a light emitting device 24 for irradiating light to the rolling contact portion 19 between the inspection roller 18 and the conductive roller DR, and the irradiation light from the light emitting device 24 is rolled between the conductive roller DR and the inspection roller 18. The unit 19 is set to irradiate.

  The rotation direction 25 of the inspection roller 18 is driven so as to be in the same direction as the direction of light irradiated from the light emitting device 24 to the rolling contact portion 19 and reaching the CCD camera 28. Further, the rotation direction 26 of the conductive roller DR is driven so as to be the same direction as the direction of light irradiated from the light emitting device 24 to the rolling contact portion 19 and reaching the CCD camera 28.

  A CCD camera 28 for photographing is disposed on the opposite side of the light emitting device 24 in order to photograph light leakage from the rolling contact portion 19 caused by fine dents, scratches or protrusions on the outer peripheral surface of the conductive roller DR. ing. Further, the image information from the CCD camera 28 is sent to the signal processing device 30.

  A discrimination method that is a feature of the present invention will be described using the discrimination device configured as described above. First, the shaft portions SH1 and SH2 of the manufactured conductive roller DR are respectively loosely fitted into the recesses 20 and 22 formed at the upper end edges of the both side plates 14 and 16 of the inspection device, respectively, and the conductive roller DR is connected to the inspection roller. Roll contact is made on 18 from above (first step). As a result, the outer peripheral surfaces of the inspection roller 18 and the conductive roller DR are brought into rolling contact with each other, and the conductive roller DR is driven and rotated in accordance with the rotation of the inspection roller 18.

  Thereafter, the inspection roller 18 is rotated, and the conductive roller DR that is in rolling contact with the inspection roller 18 is driven to rotate at least once (second step). By this driven rotation, the entire outer peripheral surface of the manufactured conductive roller DR is brought into contact with the inspection roller 18.

  On the other hand, the light from the light emitting device 24 is continuously applied to the rolling contact portion 19 between the rotating inspection roller 18 and the conductive roller DR (third step).

  The state where the light emitted from the light emitting device 24 leaks from the rolling contact portion 19 is photographed by the CCD camera 28. The obtained image information is sent to the signal processing device 30. Based on this image information, the signal processing device 30 determines whether or not the surface state of the conductive roller DR is possible (fourth step).

  Specifically, as shown in FIG. 3, the signal processing device 30 quantitatively determines the light leakage from the image transfer unit 31 that converts image information from the CCD camera into digital image information and the digital contact information 19 from the digital image information. The image processing unit 32 measures the quality of the surface of the conductive roller DR based on the quantitatively measured data.

  The image conversion unit 31 converts the image information of the light leakage from the rolling contact portion 19 between the inspection roller 18 and the conductive roller DR, which is captured by the CCD camera 28, into digital image information (first sub-process). ).

  The image processing unit 32 measures the width and height of the light leakage portion in the rolling contact portion 19 acquired as digital image information as the number of pixels (second sub-process).

  The quality determination processing unit 33 determines the quality of the surface state of the conductive roller DR from the pixel number data regarding the width and height of the light leakage portion in the rolling contact portion 19 obtained by the image processing unit 32 by a quality determination algorithm. (Third sub-process).

  FIG. 4 is a step chart showing a pass / fail judgment algorithm. Details of this step chart are shown below.

  First, if the product of the width (W) and the height (H) of the light leakage portion expressed by the number of pixels obtained by the image processing unit 32 is 15 or less, the conductive roller DR is determined to be a good product (first). 1 determination process: S10).

  Further, among products that are determined as defective products with a product of width (W) and height (H) of the light leakage portion of 16 or more, the width (W) is 150 or more and the height (H) is 8 If the following, the conductive roller DR is determined to be a non-defective product (second determination process: S12).

  If the width (W) is 149 or less and the height (H) is 5 or less from those determined as defective products in the second determination process, the conductive roller DR is determined to be a non-defective product. Others are determined as defective (third determination process: S14).

  Further, in the third determination process, the width (W) is 149 or less, the height (H) is 5 or less, and the conductive roller DR is determined to be a non-defective product, the width with respect to the height (H). If the ratio of (W), that is, W / H is 0.2 or more, the conductive roller is determined as a defective product (fourth determination process: S16).

  The determination performance of the determination device was evaluated using the pass / fail determination algorithm including the above-described determination processes. Evaluation of the judgment performance is made by preparing 47 target conductive rollers, creating a solid image by incorporating the target conductive roller DR into the printer as a result of machine judgment for judging pass / fail by a discrimination device, This was carried out by a method of comparing the results of image determination determined from image quality.

  FIG. 5 shows the comparison results. FIG. 5A shows that 25 out of the 47 conductive rollers determined to be non-defective by machine determination, 25 were determined to be non-defective by image determination, and 0 were determined to be defective by image determination. This shows that, among the 22 items determined by the machine determination as defective products, two are determined as image non-defective by image determination and 20 are determined as image defective by the image determination. FIG.5 (b) shows the result of Fig.5 (a) in the percentage which made 47 lines 100%.

  As a result, if the discriminating device is judged to be a good product and a defective product is mixed, the reliability of the pass / fail judgment is remarkably impaired. In this experiment, however, the defective product due to the image judgment is 0%, and there is no problem at all. In addition, if a non-defective product is mixed while the machine judgment is determined to be a defective product, the non-defective product is treated as a defective product and discarded, resulting in an economic waste and a reduction as much as possible. This time, while the machine judgment was judged as a defective product, the product that was judged good by the image judgment was an extremely low value of about 4%.

  According to this embodiment, the manufactured conductive roller is brought into rolling contact with the inspection roller whose outer peripheral surface is finished to a predetermined roundness, and the conductive roller is driven and driven by rotation of the inspection roller. In a method for determining the surface of a conductive roller by irradiating the contact part with light and judging whether or not the surface state of the conductive roller is based on the light leak from the rolling contact part, digitally image processing the light leak condition The pass / fail judgment processing unit 33 equipped with the pass / fail judgment algorithm can be quantitatively grasped, and the pass / fail judgment of the conductive roller can be made accurately, and the surface state can be discriminated without limitation of the inspection quantity.

  It goes without saying that the present invention is not limited to the procedure of the above-described embodiment and can be variously modified without departing from the gist of the present invention.

  For example, in the above-described embodiments, the case where the conductive roller is applied to the developing roller and the charging roller has been described. However, it goes without saying that the present invention can be applied to any roller having an elastic body on the outer peripheral surface. .

  In the above-described embodiment, the case where the image information from the CCD camera 28 is converted into the digital image information by the data conversion unit 31 has been described. However, the present invention can also be applied to the case where the digital image information is directly acquired from the CCD camera 28. Needless to say.

  Further, the discriminating apparatus of the present invention is configured such that the conductive roller is in contact with the upper part of the inspection roller so as to come into contact with its own weight, and the irradiation light from the light emitting device is irradiated almost horizontally on the contact part. However, it can also be applied to a configuration in which a conductive roller is placed close to the inspection roll and is brought into rolling contact with the pressure of a spring or the like so that irradiation light from the light emitting device is irradiated onto the rolling contact portion substantially vertically from below. Needless to say.

  If the signal processing device 30 determines that the product is defective, an NG lamp (not shown) is turned on to inform the inspector that the surface state of the conductive roller DR under inspection is defective. In parallel, the reject mechanism (not shown) is operated to discharge the conductive roller DR determined to be defective into a defective box (not shown). On the other hand, if it is determined to be non-defective, the OK lamp (not shown) is turned on. Then, the inspector is informed that the surface state of the conductive roller DR being inspected is good, and in parallel with this, the conveyance mechanism (not shown) is operated to show the conductive roller DR judged to be good. It may be configured to discharge into a non-defective box.

  In the above-described modification, the conductive roller DR determined to be a defective product is directly turned into a defective product box, and the conductive roller DR determined to be a good product is directly put into a good product box without turning on the lamp. Each of them may be automatically discharged, and if it is determined to be defective, the NG lamp is turned on, and if it is determined to be non-defective, the OK lamp is turned on to inform the inspector. Only by informing the inspection result, the inspector may put the inspected conductive roller DR into the non-defective product box or the defective product box by his / her hand based on the notification result.

  In the above-described embodiment, the rolling contact portion between the inspection roller 18 and the conductive roller DR has been described as being photographed via the CCD camera 28. However, the present invention is limited to such a procedure. Needless to say, any configuration can be used as long as the rolling contact portion can be taken in as an image, and the configuration is not limited thereto.

  In the above-described embodiment, the inspection roller 18 is described as being rotated. However, the present invention may be configured such that the inspection roller 18 is rotationally driven by a drive mechanism (not shown).

It is a front view which shows roughly the structure of the discrimination | determination apparatus for enforcing the surface discrimination method of an electroconductive roller. It is a side view which shows roughly the structure of the discrimination | determination apparatus for enforcing the surface discrimination | determination method of an electroconductive roller. It is a systematic diagram which shows the function of a signal processing apparatus. It is a step chart which shows the quality determination algorithm mounted in the quality determination process part. It is an experimental evaluation result for evaluating the discriminating device performance of a conductive roller.

Explanation of symbols

12 Base 14, 16 Side plate 18 Inspection roller 19 Rolling contact portion 20, 22 Recess 24 Light emitting device 25 Direction of rotation of inspection roller 26 Direction of rotation of conductive roller 28 CCD camera 30 Signal processing device 31 Image conversion unit 32 Image processing unit 33 Pass / fail judgment processing section
DR Conductive roller SH1, SH2 Shaft of conductive roller

Claims (8)

A first step of rolling the manufactured conductive roller onto an inspection roller whose outer peripheral surface is finished to a predetermined roundness, and rotating the inspection roller to drive the conductive roller that is in contact with the roller A second step of driving, a third step of irradiating the rolling contact portion of the rotating inspection roller and conductive roller with light, and light leakage from the rolling contact portion of the inspection roller and conductive roller. A method for determining the surface of the conductive roller, comprising: a fourth step of determining whether or not the surface state of the conductive roller is acceptable based on the occurrence of the portion;
The fourth step includes
A first sub-process for photographing the rolling contact portion of the inspection roller and the conductive roller so that the light leakage portion can be photographed;
A second sub-step of measuring the height and width of the light leakage portion from the image taken in the first sub-step;
A third sub-process for determining whether or not the surface state of the conductive roller is based on the height and width information measured in the second sub-process ,
The third sub-process includes
A first determination process for determining that the product of the width of the light leakage portion and the height of the light leakage portion is equal to or less than a first predetermined value, and determining that the product other than acceptable is impossible;
Among those determined to be impossible in the first determination process, the width of the light leakage portion is equal to or greater than a second predetermined value and the height of the light leakage portion is equal to or less than a third predetermined value. A second determination process that determines that is acceptable and other than acceptable
Among those determined to be impossible in the second determination process, the width is equal to or smaller than the second predetermined value, and the height is equal to or smaller than a fourth predetermined value smaller than the third predetermined value. A third determination process for determining whether or not
Among variable to that determined by the third determination process, those values of the ratio to the width of the height is the fifth predetermined value or more, Ru and a fourth determination process of determining impossible A method for discriminating the surface of a conductive roller.     In the fourth step, it is determined that the surface state of the conductive roller is good in the case where the light leakage does not occur, and it is determined in the third sub-step that even if the light leakage occurs. 2. The method of determining a surface of a conductive roller according to claim 1, wherein the surface state of the conductive roller is also determined as good. Wherein the first sub-step, the surface determination method of the conductive roller according to claim 1 or 2, characterized in that the said shooting obtain digital image information of the rolling contact portion.   4. The surface determination of the conductive roller according to claim 3, wherein in the second sub-step, height and width information are respectively defined from the number of pixels corresponding to the height and width in the digital image information. Method. In the first determination process, the first predetermined value is preferably a value corresponding to about 15 as an actual measurement value of the light leakage portion, and in the second determination process, the first predetermined value is Preferably, it is a value corresponding to about 150 as an actual measurement value of the light leakage portion,
The second predetermined value is preferably a value corresponding to about 8 as an actual measurement value of the light leakage portion,
In the third determination process, the fourth predetermined value is preferably a value corresponding to about 5 as an actual measurement value of the light leakage portion,
Wherein the fourth determination process, the fifth predetermined value surface determination method of the conductive roller according to claim 4, characterized in that preferably about 0.2. The conductive roller according to any one of claims 1 to 5, wherein the conductive roller and the inspection roller are rotated so that a traveling direction of the rolling contact portion of the conductive roller and the inspection roller is directed to the light imaging unit. To distinguish the surface of the adhesive roller. The conductive roller, a surface determination method of the conductive roller according to any one of claims 1 to 6, characterized in that a charging roller for charging the photosensitive member in an electrophotographic apparatus. The surface of the conductive roller according to claim 1, wherein the conductive roller is a developing roller for supplying a developer to a photosensitive surface of a photosensitive member in an electrophotographic apparatus. How to determine.

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