JP2005208422A - Fixing roll streak inspecting device and control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To detect an image defect caused by damage to or deformation of a fixing roll. <P>SOLUTION: A fixing roll streak inspecting device obtains inspection image data created by imaging printed paper fixed by a fixing roll, and the width of the paper (S14 and S16). Further, the device obtains the history of the width of paper which has been fixed in the past (S18). In the case where fixing has been performed on the sheet of paper whose width is smaller than the width of the printed paper relative to the inspection image data (S20) and the number of processed sheets of paper is a predetermined number or more (S22), the fixing roll streak inspecting device obtains a correspondence position in which the contact range boundary of the fixing roll corresponding to the paper that has the paper width corresponds to the printed paper used for the inspection image data (S24). Next, an inspection is carried out for a streak image defect near the correspondence position (S26). <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for inspecting a print image using inspection image data, and more particularly to an inspection technique for a print image that has undergone a fixing process by a fixing roll.

  There is a technique for performing an image quality inspection of a print image using inspection image data generated by imaging a sheet on which a print image is formed by an image forming apparatus. In this image quality inspection, it may be desired to detect streak defects that appear due to defects in the fixing roll.

  Japanese Patent Application Laid-Open Publication No. 2004-228561 discloses a technique for outputting a uniformly gray printed image and detecting white or black low-contrast streaks in the printed image. Patent Document 2 listed below discloses a technique for outputting a white print image uniformly and detecting a stain in the print image.

Japanese Patent Laid-Open No. 6-148096 JP-A-6-168316

  In the technique of the above-mentioned Patent Document 1, streak-like image defects appearing at various locations in a printed image are detected. However, with this technology, it is difficult to improve the inspection efficiency and inspection accuracy of streak-like image defects caused by the fixing roll. This is because, in the fixing roll, scratches and deformation are likely to occur near the boundary portion of the sheet, and the corresponding image defect occurrence location is limited.

  An object of the present invention is to detect a streak-like image defect caused by a fixing roll.

  Another object of the present invention is to improve the efficiency or accuracy of detecting image defects.

  The fixing roll streak inspection apparatus according to the present invention includes inspection image data acquisition means for acquiring inspection image data generated by imaging a printed sheet having a certain sheet width on which a print image is formed through fixing processing by a fixing roll, and Corresponding to the inspection image data, the boundary position of the contact range of the fixing roll used for fixing the paper width of the printed paper and the fixing width of the printed paper having another paper width is acquired. Means for obtaining a position, corresponding position obtaining means for obtaining at least one corresponding position included in the printed sheet having the certain sheet width, and streak-like image quality defects in the printed sheet having the certain sheet width. And inspection means for inspecting the vicinity of the corresponding position of the inspection image data of the printed paper.

  The fixing roll fixes the printed image by applying pressure or heating and pressing while rotating. The inspection image data is generated by optically reading the printed paper that has undergone the fixing process. The fixing roll and the inspection image data generation unit may be included in the fixing roll muscle inspection device or may be provided as an external device. The inspection image data acquisition unit acquires the inspection image data generated in this way. The paper width acquisition unit acquires the paper width based on input from an external device, user input, sensor recognition, inspection image data analysis result, and the like. As the paper, roll paper or cut paper having a paper width of an arbitrary length or a paper width of a predetermined standard is used. The paper width is the length of the fixing roll in the roll axis direction. The contact range in which the fixing roll contacts the paper during the fixing process is usually fixed for each paper width.

  Corresponding position acquisition means associates the position of a printed sheet having another sheet width included inside the boundary of the printed sheet having a certain sheet width on the inspection image data. Specifically, the position of the contact range boundary of the fixing roll used for fixing processing of printed paper having another paper width indicates the corresponding position corresponding to the printed paper having a certain paper width on the inspection image data. get. Thereby, the inspection unit can inspect the vicinity of the corresponding position of the inspection image data. The inspection means inspects streaky image quality defects in the vicinity. That is, for example, the presence or absence of image quality defects is inspected by detecting streak stains, streak density defects or gloss defects in a printed image, and the like. The direction of the streak is not particularly limited, but it is particularly preferable that the inspection in the direction perpendicular to the roll axis of the fixing roll is focused or only the inspection in the direction perpendicular to the roll axis of the fixing roll is performed. In addition, it is possible to inspect streaky image quality defects for other areas, but add sharpness such as high-resolution inspection near the corresponding position or only inspection near the corresponding position. Is also particularly preferred.

  According to this configuration, it becomes possible to inspect the streak-like image defect in a focused manner or with high accuracy in accordance with the generation characteristics thereof. In particular, an image defect often appears at the boundary of the contact range used for fixing a sheet having a different sheet width, and this image defect can be intensively inspected.

  Preferably, in the fixing roll streak inspection apparatus according to the present invention, the inspection unit inspects a streak-like image defect caused by a defect generated near the boundary of the contact range of the fixing roll. Scratches and plastic deformation may occur in the vicinity of the boundary of the contact range of the fixing roll, and image defects are caused by pressurization and heating unevenness due to this, adhesion of dirt, and the like. Therefore, the inspection means had characteristics such as the position of the defect (relationship with the corresponding position, etc.), width, direction (typically a direction perpendicular to the roll axis), quality (gloss characteristics, density characteristics, etc.). Conduct an inspection. These characteristics can be obtained, for example, by repeatedly performing an experiment on statistical processing. The inspection means may perform a type of inspection that positively finds defects of the obtained characteristics, and the fixing roll based on how many elements of such characteristics are included in general-purpose inspection results. You may detect the image defect resulting from this. Note that it is also effective to cause the fixing roll streak inspection apparatus or an external device to take measures for notifying the occurrence of a defect by the fixing roll or prompting the replacement of the fixing roll based on the determination result.

  Preferably, the fixing roll streak inspection device of the present invention includes a record acquisition unit that acquires a record of a sheet width of a printed sheet that has been fixed by the fixing roll, and the inspection unit uses the acquisition result of the record acquisition unit. Based on this, an inspection is performed for the vicinity of the corresponding position with respect to the sheet width fixed in the past. The recording means itself may be included in the fixing roll muscle inspection device or may be provided in an external device. In addition, it is particularly preferable that the corresponding position is acquired only for a target to be inspected, but a target other than the target for inspection may be acquired. As a result, it is not necessary to perform at least a detailed inspection about the corresponding position of the paper width that has not been fixed in the past, or the inspection itself, and an efficient inspection is possible.

  Preferably, in the fixing roll streak inspection apparatus according to the present invention, the inspection unit performs an inspection on the vicinity of the corresponding position with respect to a sheet width in which a quantity fixed in the past satisfies a setting condition. This configuration is adopted in consideration of the fact that defects at the contact area boundary of the fixing roll occur with a large amount of processing. In other words, by inspecting the corresponding position for the paper width that satisfies the appropriate conditions, it is possible to increase the efficiency of the inspection time and to increase the accuracy of the few inspection locations. The setting conditions can be appropriately determined based on the durability quality of the fixing roll. The setting condition may be, for example, a condition in which one or several sheets are inspected only when the quantity reaches a certain value, or an inspection is performed periodically or every time after the quantity reaches a certain value. Condition may be sufficient.

  Desirably, in the fixing roll streak inspection apparatus of the present invention, the setting condition is a condition regarding a quantity subjected to cumulative fixing processing. The cumulatively fixed quantity refers to the total number of printed sheets processed in the past, the total print amount in consideration of the length of the processed sheet in the direction perpendicular to the fixing roll axis, and the like.

  Desirably, in the fixing roll streak inspection apparatus according to the present invention, the setting condition is a condition regarding a quantity subjected to continuous fixing processing. The quantity that has been continuously fixed is the quantity that has been processed continuously without changing to other paper widths, or the fixing processing ratio for other paper widths is low (for example, 10% or 5%). This means the quantity processed with the same paper width almost continuously. In any case, a pause period in which the fixing process is not performed (printing process is not performed) may be included.

  Desirably, in the fixing roll streak inspection apparatus of the present invention, the setting condition is set in at least two stages according to the quantity fixed in the past. For example, until a predetermined number of sheets (for example, 50,000 sheets) has been processed in the past, inspection is performed every predetermined number of sheets (for example, 10,000 sheets). The inspection frequency may be changed such that the inspection is performed every predetermined number of sheets (for example, 1000 sheets). Since the fixing roll generally deteriorates according to the processing quantity, it is effective to change the inspection system according to the processing quantity.

  Preferably, the fixing roll streak inspection apparatus according to the present invention includes a determination unit that determines whether or not a print image is included in the vicinity of the corresponding position of the inspection image data, and the inspection unit determines the determination unit by the determination unit As a result, if the print image is included, the image quality defect is inspected for the printed paper. If the print image is not included, the fixing process is performed after that and the print image is near the corresponding position. The image quality defect is inspected with respect to a printed sheet containing the image. For example, in the case of inspecting based on the density of a print image, the inclusion of the print image is a requirement for enabling the inspection. Therefore, determination means is provided to determine the presence / absence of a print image.

  Desirably, in the fixing roll streak inspection device of the present invention, the accuracy of the inspection by the inspection means is set in at least two stages according to the quantity fixed in the past. The accuracy of the inspection is measured by the number of inspection objects, the resolution for performing the inspection, the number of inspection procedures, and the like. For example, until a predetermined number (for example, 50,000) of the number of pieces that have been processed in the past, one sheet is inspected for every predetermined number (for example, 10,000). Alternatively, the number of inspection objects may be changed such that a plurality of (for example, five) inspections are performed. Alternatively, the length of the printed paper (the length in the direction perpendicular to the roll axis of the fixing roll) is changed from a predetermined amount (for example, half of the paper) to a larger amount (for example, one sheet). The target amount may be changed. It is also effective to change the resolution so that the inspection image data is used at a lower resolution or at the original resolution. Furthermore, the number of procedures is changed so that streak detection is performed based on only one method (for example, gloss difference) or streak detection is performed based on two different methods (for example, gloss difference and density difference). May be.

  Desirably, in the fixing roll streak inspection device of the present invention, when the fixing roll is replaced, the inspection unit performs an inspection based on the records acquired after the replacement acquired by the record acquisition unit. This is because when the fixing roll is replaced, it is not necessary to refer to the previous fixing processing history.

  Preferably, in the fixing roll streak inspection apparatus according to the present invention, the inspection unit performs an inspection on the vicinity of the corresponding position that is not included in a printed sheet of another sheet width fixed immediately before. Normally, the corresponding positions included in a sheet of another sheet width that has been fixed immediately before have already been inspected, so only the corresponding positions that will be newly included are subject to inspection.

  Preferably, in the fixing roll streak inspection device according to the present invention, the contact range is fixed for each sheet width so that a contact range for a small sheet width is included in a contact range for a larger sheet width. The inspection means, when the paper width of the printed paper is larger than the paper width of the printed paper fixed immediately before, the paper width of the printed paper fixed immediately before, or the The inspection is performed in the vicinity of the corresponding position for the paper width smaller than the paper width of the printed paper to be inspected larger than the paper width of the printed paper fixed immediately before. That is, the contact range is fixed so that the contact range for the small paper width does not protrude from the contact range for the larger paper width (the boundary may be common). In this case, the inspection object can be determined based on the size of the paper width.

  The fixing roll streak inspection program according to the present invention includes a procedure for acquiring inspection image data generated by imaging a printed sheet having a certain sheet width on which a print image is formed through a fixing process by a fixing roll. The procedure to obtain the paper width of the printed paper and the corresponding position corresponding to the inspection image data corresponding to the boundary position of the contact range of the fixing roll used for fixing processing of the printed paper having another paper width. A procedure for obtaining at least one corresponding position included in a printed sheet having a certain sheet width, and a streak-like image quality defect in the printed sheet having the certain sheet width. And inspecting the vicinity of the corresponding position of the inspection image data.

  The fixing roll streak inspection method of the present invention is a method executed by a computer, and acquires inspection image data generated by imaging a printed sheet of a certain sheet width on which a printed image is formed through fixing processing by a fixing roll. A step of acquiring a sheet width of the printed sheet, and a boundary position of a contact range of a fixing roll that is fixedly used for fixing a printed sheet having a different sheet width is made to correspond to the inspection image data. Obtaining the corresponding position, the step of obtaining at least one corresponding position included in the printed sheet having the certain sheet width, and the streak-like image quality defect in the printed sheet having the certain sheet width, And inspecting the vicinity of the corresponding position of the inspection image data of the printed paper.

  The control device according to the present invention includes a temporary forming unit that temporarily forms a print image on a paper having a certain paper width based on original image data, and a boundary position is fixed for each paper width with respect to the paper on which the print image is temporarily formed. An image forming unit including a fixing roll that discharges a printed sheet on which a printed image is fixed by performing heating and pressurization using the contact range, and generates inspection image data by imaging the printed sheet An apparatus for controlling at least a part of a system comprising: a generating unit; and an inspection unit that performs an image quality inspection of the printed paper using the inspection image data, wherein the printed paper is A corresponding position acquisition instruction for acquiring a corresponding position on the inspection image data corresponding to the boundary position of at least one contact range for another sheet width whose boundary position is included in the contact range for the other sheet width If, with respect to the inspection unit, a target near the corresponding position of the test image data comprises a test instruction means for checking the stripe-like image defect, the. The control device may be incorporated in the entire system or a part of the system, or may be configured in a separate housing from the system.

  The control program according to the present invention includes a temporary forming unit that temporarily forms a print image based on original image data on a sheet having a certain sheet width, and a boundary position is fixed for each sheet width with respect to the sheet on which the print image is temporarily formed. An image forming unit including a fixing roll that discharges a printed sheet on which a printed image is fixed by performing heating and pressurization using the contact range, and generates inspection image data by imaging the printed sheet A program executed in a system comprising: a generating unit; and an inspection unit that executes an image quality inspection of the printed paper using the inspection image data, the program being executed within a contact range for the paper width of the printed paper A procedure for obtaining a corresponding position on the inspection image data corresponding to the boundary position, and at the inspection means, with respect to at least one contact range for another paper width whose boundary position is included in As a target near the corresponding position of the image data, including a step of checking the stripe-like image defect, the.

  According to the control method of the present invention, a boundary position is fixed for each paper width with respect to a temporary forming unit that temporarily forms a print image on a paper having a certain paper width based on original image data, and a paper on which the print image is temporarily formed. An image forming unit including a fixing roll that discharges a printed sheet on which a printed image is fixed by performing heating and pressurization using the contact range, and generates inspection image data by imaging the printed sheet A method executed by a system comprising: a generating unit; and an inspection unit that executes an image quality inspection of the printed paper using the inspection image data, the method being performed within a contact range for a paper width of the printed paper With respect to at least one contact range for another sheet width including the boundary position, obtaining a corresponding position on the inspection image data corresponding to the boundary position; and in the inspection unit, before the inspection image data As a target near the corresponding position, comprising the steps of checking the stripe-like image defect, the.

  Hereinafter, typical embodiments of the present invention will be described.

  FIG. 1 is a perspective view showing an image defect occurrence situation assumed in the present embodiment. Here, a state is shown in which the paper 14 is conveyed while being sandwiched between the upper roll 10 and the lower roll 12 which are two rotating cylindrical fixing rolls. The upper roll 10 and the lower roll 12 are made of a material such as elastic resin on the surface thereof, and pressurize the paper 14. The upper roll 10 incorporates a heat source such as a halogen lamp to heat the paper 14. For this reason, the fixing roll is sometimes called a heat roll. A printed image 16 is temporarily formed on the paper 14 at a portion not shown. Then, the temporarily formed print image 16 is heated and pressed together with the paper 14 by the upper roll 10 and the lower roll 12, whereby the toner or the like of the temporarily formed print image is melted and fixed on the paper 14.

  A contact range in which heating and pressurization are performed in direct contact with the paper during the fixing process is fixed for each paper width of the paper. For example, the contact range of the upper roll 10 with respect to the paper width of the paper 14 is a range sandwiched between the curve 18 and the curve 20. For this reason, when a large amount of paper having the same paper width is fixed, the inhomogeneous force acting on the portion corresponding to the side edge of the paper (the portion of the curve 18 and the curve 20 for the paper 14) and the correspondence This part may be damaged or plastically deformed due to inhomogeneous deformation.

  In FIG. 1, since a large amount of paper smaller than the paper 14 is fixed, concave deformed portions 22 and 24 are generated near the boundary of the contact range. In the vicinity of the concave deformed portions 22 and 24, the fixing of the printed image as uneven gloss or uneven density due to non-uniform heating when the paper 14 is fixed and unevenness in the melting of the toner occurs. Roll muscles 26 and 28 are generated. Further, the fixing roll stripes 26 and 28 may be generated due to dirt caused by the concave deformation portions 22 and 24. The fixing roll stripes 26 and 28 can also be generated when the lower roll 12 is damaged or deformed. Hereinafter, a technique relating to detection of the fixing roll streaks 26 and 28 will be disclosed.

  FIG. 2 is a schematic functional block diagram relating to the image forming system 30 according to the present embodiment. The image forming system 30 includes an image forming unit 40, an inspection image data generation unit 60, a control unit 70, and a fixing roll streak inspection unit 80 as main components.

  The image forming unit 40 is a multi-color or single-color printer device, copier, or the like, that is, a device that forms a print image on a sheet based on original image data. As a characteristic configuration, the image forming unit 40 includes a temporary forming unit 42, a fixing processing unit 44, a recording unit 46, a clear unit 48 included in the recording unit 46, and a size setting unit 50. The temporary forming unit 42 is a part that temporarily forms a printed image on a sheet based on original image data. For example, in the case of an electrophotographic method, a toner image formed on a photosensitive drum or a transfer belt is formed on a sheet. Borrowing is done by transcription. The fixing processing unit 44 includes a fixing roll, and performs a fixing process for fixing a temporarily formed print image by heating and pressurizing a sheet. The recording unit 46 includes a storage device such as a semiconductor memory or a hard disk, and records the sheet width of the fixed sheet. The clear unit 48 clears the recording of the recording unit 46 at the timing when the fixing roll is replaced. The size setting unit 50 is a part for setting the size of paper on which an image is formed, and is set by user designation or automatic selection.

  The recording unit 46 records the size based on the setting result of the size setting unit 50. An important point in recording the size is recording so that the sheet width of the fixing roll in the roll axis direction can be specified, and more precisely, recording so that the boundary of the contact range of the fixing roll can be specified. Therefore, when a size conforming to the standard is used, recording is performed such as A4 portrait, B5 landscape, postcard portrait, and the like. In general, A4 landscape and A3 portrait have the same sheet width. Therefore, when the amount of processing in the direction perpendicular to the roll axis of the fixing roll is not a problem, both may be handled without distinction.

  The inspection image data generation unit 60 is an apparatus that generates inspection image data, and includes an imaging unit 62 as a configuration for that purpose. The imaging unit 62 optically reads the paper (printed paper) on which the print image has been fixed by the image forming unit 40 and converts it into an electrical signal. The inspection image data generation unit 60 generates inspection image data based on this electrical signal. The inspection image data may be single color data or multicolor data. In general, the fixing roll streak can be clearly grasped in the case of monochromatic data, but even multicolor data can be detected with sufficient accuracy. Therefore, it is only necessary to decide whether to use single color data or multicolor data in combination with other image quality inspections. The inspection image data generation unit 60 may be installed in the same housing as the image forming unit 40 or the fixing roll streak inspection unit 80, or may be configured as a separate housing.

  The control unit 70 controls the image forming system 30. That is, the operations of the image forming unit 40, the inspection image data generation unit 60, and the fixing roll streak inspection unit 80 are controlled, and these are operated as an integrated system. The control unit 70 can perform control by prescribing the operation of hardware such as a PC (personal computer) or an ASIC having a calculation function by software (program). The control unit 70 may be provided in the same housing as at least one of the image forming unit 40, the inspection image data generation unit 60, and the fixing roll muscle inspection unit 80, or may be provided as a separate housing. The functions of the control unit 70 may be distributed and arranged in the image forming unit 40, the inspection image data generation unit 60, the fixing roll stripe inspection unit 80, and the like.

  The fixing roll streak inspection unit 80 is typically configured using a PC, and inspects the fixing roll streak based on a program incorporated in the PC or a command from the control unit 70. The fixing roll streak inspection unit 80 is characterized by an input / output unit 82, a UI unit 84, an inspection image data acquisition unit 86, a paper width acquisition unit 88, a recording acquisition unit 90, a condition determination unit 92, and a corresponding position acquisition unit. 94, an image content determination unit 96, and a muscle detection unit 98.

  The input / output unit 82 is a part that transmits / receives command signals to / from the control unit 70 and transmits / receives data to / from the image forming unit 40 and the inspection image data generating unit 60. In addition, data can be transmitted / received to / from an external device through a network. The UI unit 84 includes an input device such as a keyboard and a display device such as a display, and plays a role of receiving a command signal from the user and transmitting information to the user. The inspection image data acquisition unit 86 inputs inspection image data from the inspection image data generation unit 60 via the input / output unit 82. Further, the paper width acquisition unit 88 acquires information on the paper width corresponding to the inspection image data from the size setting unit 50 via the input / output unit 82.

  The record acquisition unit 90 acquires history information that has been fixed in the past from the recording unit 46 via the input / output unit 82. The history information includes information on the sheet width of the fixed sheet. Based on the acquired history information, the condition determination unit 92 aggregates the paper width printed in the past and the quantity information of the paper of each paper width, and compares it with preset conditions, thereby checking the necessity of inspection and the inspection. The target paper width is determined. The corresponding position acquisition unit 94 acquires the position of the side edge of the paper width determined to be inspected by the condition determination unit 92. In other words, a corresponding position corresponding to the boundary position of the contact range of the fixing roll used in the fixing process for the sheet width determined to be inspected is obtained in the inspection image data. Acquisition of the corresponding position is possible in various ways, for example, by selecting from the corresponding position corresponding to each paper width stored in advance based on user input or sensor detection, or by measuring with a sensor or the like at the time of acquisition. It is. The image inclusion determination unit 96 analyzes the inspection image data and determines whether or not a print image is included in the vicinity of the acquired corresponding position. In general, the fixing roll stripe inspection can be performed with high accuracy when a printed image is included. Therefore, when the print image is appropriately included, the image quality inspection is performed on the portion, and when the print image is not included, the inspection is performed when the included inspection image data is acquired. The determination by the image content determination unit 96 can be quickly executed with a rough resolution or the like.

  The streak detecting unit 98 detects streak-like image defects in the vicinity of the corresponding position of the inspection image data. In the detection, for example, the original image data used for forming the print image is input from the image forming unit 40 via the input / output unit 82 and compared with the inspection image data. It is possible to distinguish between the included muscles. Further, when detecting a line, for example, a filter based on a difference value between neighboring pixel values can be used. In this way, image defects due to the fixing roll are detected. When an image defect is detected, it is transmitted to the user through the display of the UI unit 84, and a warning is given to promptly replace the fixing roll.

  In addition, the fixing roll streak inspection unit 80 may be provided with a configuration for inspecting general image defects. That is, it is possible to provide a general inspection unit that detects density unevenness and color unevenness of a printed image and detects stains on the paper.

  Next, an example of a process in which fixing roll streaks are detected in the image forming system 30 will be described with reference to the flowchart of FIG. In the image forming unit 40, printing is executed based on a print job execution command from the user (S10). At this time, the sheet size selected by the user or automatically is recorded in the recording unit 46 (S12). The image-formed printed paper is imaged by the imaging unit 62, and the inspection image data generation unit 60 generates inspection image data based on the imaging result. Then, the inspection image data acquisition unit 86 of the fixing roll stripe inspection unit 80 acquires this inspection image data (S14).

  When the inspection roll data is input, the fixing roll stripe inspection unit 80 acquires the paper width of the printed paper corresponding to the inspection image data by the paper width acquisition unit 88 (S16). Further, the record acquisition unit 90 acquires the history of the paper width processed in the past print job from the recording unit 46 (S18). The condition determination unit 92 refers to this history and determines whether or not a sheet having a sheet width smaller than the sheet width of the current sheet has been printed in the past (S20). This is based on the fact that the fixing roll of the fixing processing unit 44 is used so that the contact range with respect to a sheet with a small sheet width is included in the contact range with respect to a sheet with a large sheet width (the boundary may be the same). . That is, the contact range boundary of the fixing roll used for the fixing process of the past printed paper is essentially included in the range of the fixing roll used for the fixing process of the printed sheet of the current inspection image data. It is determined whether or not. If it is not included, the fixing roll streak is not inspected.

  On the other hand, if it is included, the condition determination unit 92 further performs determination based on the set condition. Here, as an example, it is inspected whether or not the print processing number of accumulated small paper widths is equal to or greater than a predetermined number (for example, 50,000) (S22). If the predetermined number is not reached, the inspection is not performed. If the predetermined number is exceeded, it is determined that the inspection is necessary from the viewpoint of durability of the fixing roll. When it is determined that there is a need for inspection, the corresponding position acquisition unit 94 acquires a corresponding position corresponding to the contact range boundary of the small paper width on the inspection image data based on data registered in advance (S24). ). Subsequently, the streak detection unit 98 detects a streak-like image defect near the corresponding position using the inspection image data (S26). If necessary, the image inclusion determination unit 96 may be used to inspect only when an image is included near the corresponding position.

  Various conditions other than those shown in step S22 can be set in the condition determination unit 92. For example, by utilizing the fact that the deterioration of the fixing roll does not proceed rapidly, when the past number of processed sheets exceeds a predetermined number, the inspection may be performed every certain number of sheets (for example, 1000 sheets). Further, when a plurality of paper widths are used, it is possible to devise such as reducing the inspection frequency by utilizing the fact that plastic deformation is less likely to proceed than when a single paper width is used. .

  Next, an example of the examination in the muscle detection unit 98 will be described with reference to FIG. FIG. 4 is a diagram illustrating the process of detecting the fixing roll streak using the inspection image data in three stages. FIG. 4A schematically shows the contents represented by the inspection image data before the inspection, and the printed image 112 is included on the printed paper 110. Fixing roll streaks 114 and 116 are formed at positions corresponding to the contact range boundary of the small paper width. The printed paper 110 is carried in and out of the fixing roll in the vertical direction of the paper surface and is processed. Therefore, the fixing roll streaks 114 and 116 extend in the vertical direction on the paper surface, that is, in the direction perpendicular to the roll axis of the fixing roll.

  The streak detecting unit 98 removes the print image component by taking a difference from the original image data used for forming the print image in the examination. FIG. 4B shows the “dirt candidate” component represented by the difference data thus obtained. That is, the print image 112 shown in FIG. 4A is removed, and the fixing roll streaks 114 and 116 are left. This eliminates the risk of erroneous determination when the print image 112 includes a streak-like image component. In general, since other types of stain candidate components are also detected, a filtering process that leaves only the streak components may be performed at this time as necessary.

  Subsequently, as shown in FIG. 4C, the regions 118 and 120 near the corresponding positions are selected as the inspection target regions. Then, it is determined whether or not the stain candidate components in the regions 118 and 120 have streak-like stains. The detection of streak-like dirt is possible in various ways. For example, it may be detected by a filtering process that leaves streak-like components, or a histogram in which pixel values are integrated in a direction perpendicular to the roll axis is created and limited You may detect that there is dirt only in the range. It is also effective to detect a streak component (a relatively large frequency component in the muscle direction) by frequency analysis.

  In the process illustrated in FIG. 4, difference data is created for the entire printed sheet 110. This is because other image quality inspections using the difference data are taken into consideration. When only the fixing roll stripe inspection is performed, the difference processing is performed only on the regions 118 and 120 near the corresponding position from the beginning. Also good. In addition to this, it is possible to detect fixing roll streaks using various methods, but in any case, it is expected that fixing roll streaks appear as shown in FIG. 4C. This is the point where the vicinity is predicted. That is, it is possible to limit the portion where the streak-like dirt is detected to the regions 118 and 120, or to confirm that the detected streak-like stain is included in the regions 118 and 120. It is effective in detection.

  Next, processing when replacing the fixing roll will be described with reference to the flowchart of FIG. The fixing roll is replaced based on a warning display when the fixing roll streak is detected, or simply based on the number of processings (S30). In this case, the clear unit 48 clears the past record recorded in the recording unit 46 (S32), thereby making it possible to leave a history of the sheet width processed by the new fixing roll. The clear unit 48 can grasp the replacement of the fixing roll based on, for example, user input, or may automatically grasp based on an IC tag or the like attached to the fixing roll. According to this configuration, the fixing roll streak inspection unit 80 can proceed with the processing related to the inspection without recognizing the replacement of the fixing roll.

  Various measures other than the procedure shown in FIG. 5 can be taken for the replacement of the fixing roll. As an example, it is possible to cause the fixing roll muscle inspection unit 80 side to recognize the replacement of the fixing roll, and to use the record after the replacement when acquiring or using the recording.

FIG. 6 is a perspective view illustrating generation of fixing roll streaks. 1 is a block diagram illustrating a schematic configuration of an image forming system including a fixing roll streak inspection unit. 5 is a flowchart showing a flow of processing relating to detection of fixing roll stripes. It is a schematic diagram explaining the muscle detection process using test | inspection image data. 6 is a flowchart for explaining processing when a fixing roll is replaced.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Upper roll, 12 Lower roll, 14 Paper, 16 Print image, 18 curve, 20 curve, 22, 24 Concave deformation part, 26, 28 Fixing roll stripe, 30 Image formation system, 40 Image formation part, 42 Temporary formation part , 44 fixing processing unit, 46 recording unit, 48 clearing unit, 50 size setting unit, 60 inspection image data generation unit, 62 imaging unit, 70 control unit, 80 fixing roll muscle inspection unit, 82 input / output unit, 84 UI unit, 86 Inspection image data acquisition unit, 88 Paper width acquisition unit, 90 Record acquisition unit, 92 Condition determination unit, 94 Corresponding position acquisition unit, 96 Image content determination unit, 98 Streak detection unit, 110 Printed paper, 112 Print image, 114 , 116 fixing roll streaks, 118, 120 regions.

Claims (17)

Inspection image data acquisition means for acquiring inspection image data generated by imaging a printed sheet of a certain sheet width on which a print image is formed through a fixing process by a fixing roll;
Paper width acquisition means for acquiring the paper width of the printed paper;
A means for obtaining a corresponding position in which a boundary position of a contact range of a fixing roll that is fixedly used for fixing processing of a printed sheet having another sheet width is made to correspond to inspection image data, and printing the certain sheet width Corresponding position acquisition means for acquiring at least one corresponding position included in the finished paper;
Inspection means for inspecting streaky image quality defects in the printed paper of the certain paper width in the vicinity of the corresponding position of the inspection image data of the printed paper;
A fixing roll muscle inspection device comprising: The fixing roll muscle inspection device according to claim 1,
The fixing roll streak inspection apparatus characterized in that the inspection unit inspects a streak-like image defect caused by a defect generated near a boundary of a contact range of the fixing roll. The fixing roll muscle inspection device according to claim 1,
A record acquisition means for acquiring a record of the sheet width of the printed sheet fixed by the fixing roll;
The fixing roll streak inspection apparatus, wherein the inspection unit performs an inspection on the vicinity of the corresponding position with respect to a paper width that has been subjected to a fixing process in the past, based on an acquisition result of the record acquisition unit. The fixing roll muscle inspection device according to claim 3,
The fixing roll streak inspection apparatus, wherein the inspection unit performs an inspection on the vicinity of the corresponding position with respect to a sheet width in which a quantity fixed in the past satisfies a setting condition. The fixing roll muscle inspection device according to claim 4,
The fixing roll streak inspection apparatus according to claim 1, wherein the setting condition is a condition for a cumulatively fixed quantity. The fixing roll muscle inspection device according to claim 4,
The fixing roll streak inspection apparatus according to claim 1, wherein the setting condition is a condition regarding a quantity subjected to continuous fixing processing. The fixing roll muscle inspection device according to claim 4,
The fixing roll streak inspection apparatus, wherein the setting condition is set in at least two stages according to a quantity fixed in the past. The fixing roll muscle inspection device according to claim 4,
Determination means for determining whether or not a print image is included in the vicinity of the corresponding position of the inspection image data;
The inspection unit inspects the image quality defect with respect to the printed sheet when the print image is included as a result of the determination by the determination unit, and after that when the print image is not included. A fixing roll streak inspection apparatus characterized in that the image quality defect is inspected with respect to a printed sheet that has been subjected to fixing processing and includes a printed image in the vicinity of the corresponding position. The fixing roll muscle inspection device according to claim 3,
The accuracy of the inspection by the inspection means is set in at least two stages according to the quantity fixed in the past. The fixing roll muscle inspection device according to claim 3,
When the fixing roll is replaced, the inspection unit performs an inspection based on a record acquired after the replacement acquired by the record acquisition unit. The fixing roll muscle inspection device according to claim 3,
The fixing roll streak inspection apparatus characterized in that the inspection means inspects the vicinity of the corresponding position that is not included in a printed sheet of another sheet width that has been fixed immediately before. The fixing roll muscle inspection device according to claim 11,
The contact range is fixed for each paper width so that a contact range for a small paper width is included in a contact range for a larger paper width,
When the paper width of the printed paper is larger than the paper width of the printed paper that has been fixed immediately before, the inspection unit determines whether or not the paper width of the printed paper that has been fixed immediately before or A fixing roll streak inspection characterized in that an inspection is performed in the vicinity of the corresponding position with respect to a paper width smaller than the paper width of a printed paper to be inspected larger than the paper width of the printed paper fixed on apparatus. Against the computer
A procedure for acquiring inspection image data generated by imaging a printed sheet of a certain sheet width on which a print image is formed through a fixing process by a fixing roll;
A procedure for obtaining the paper width of the printed paper;
A procedure for obtaining a corresponding position in which a boundary position of a contact range of a fixing roll that is fixedly used for fixing processing of a printed sheet having another sheet width is made to correspond to inspection image data, and printing the certain sheet width A procedure for obtaining at least one corresponding position included in the finished paper;
A procedure for inspecting streaky image quality defects in the printed paper of the certain paper width for the vicinity of the corresponding position of the inspection image data of the printed paper;
The fixing roll muscle inspection program characterized by the above. A method performed by a computer,
Obtaining inspection image data generated by imaging a printed sheet of a certain sheet width on which a printed image is formed through a fixing process by a fixing roll;
Obtaining a paper width of the printed paper;
A step of acquiring a corresponding position in which a boundary position of a contact range of a fixing roll that is fixedly used for fixing processing of a printed sheet having another sheet width is made to correspond to inspection image data, and printing with the certain sheet width Obtaining at least one corresponding position included in the finished paper;
Inspecting streaky image quality defects in the printed paper of the certain paper width for the vicinity of the corresponding position of the inspection image data of the printed paper;
A fixing roll muscle inspection method comprising: Heating using a temporary forming unit that temporarily forms a print image on a sheet of a certain width based on original image data, and a contact range in which a boundary position is fixed for each sheet width on the sheet on which the print image is temporarily formed And a fixing roll that performs pressurization and discharges printed paper on which the printed image is fixed;
Generating means for imaging the printed paper and generating inspection image data;
Inspection means for performing an image quality inspection of the printed paper using the inspection image data;
A device for controlling at least a part of a system comprising:
The corresponding position on the inspection image data to which the boundary position corresponds to at least one contact range for another paper width whose boundary position is included in the contact range for the paper width of the printed paper with respect to the system Corresponding position acquisition instructing means for acquiring
Inspection instruction means for inspecting the image quality defect for the inspection means near the corresponding position of the inspection image data; and
A control device comprising: Heating using a temporary forming unit that temporarily forms a print image on a sheet of a certain width based on original image data, and a contact range in which a boundary position is fixed for each sheet width on the sheet on which the print image is temporarily formed And a fixing roll that performs pressurization and discharges printed paper on which the printed image is fixed;
Generating means for imaging the printed paper and generating inspection image data;
Inspection means for performing an image quality inspection of the printed paper using the inspection image data;
A program executed in a system comprising:
A procedure for acquiring a corresponding position on the inspection image data corresponding to the boundary position of at least one contact range for another sheet width whose boundary position is included in the contact range for the sheet width of the printed sheet; ,
In the inspection means, a procedure for inspecting a stripe-like image quality defect for the vicinity of the corresponding position of the inspection image data,
A control program comprising: Heating using a temporary forming unit that temporarily forms a print image on a sheet of a certain width based on original image data, and a contact range in which a boundary position is fixed for each sheet width on the sheet on which the print image is temporarily formed And a fixing roll that performs pressurization and discharges printed paper on which the printed image is fixed;
Generating means for imaging the printed paper and generating inspection image data;
Inspection means for performing an image quality inspection of the printed paper using the inspection image data;
A method performed by a system comprising:
Obtaining a corresponding position on the inspection image data to which the boundary position corresponds with respect to at least one contact range for another sheet width that includes a boundary position within the contact range for the sheet width of the printed sheet; ,
In the inspection means, inspecting a streak-like image quality defect for the vicinity of the corresponding position of the inspection image data; and
A control method comprising:

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