JP2008170549A - Image forming apparatus - Google Patents

Abstract

An abnormality detection image that is likely to cause an abnormal image due to a charging unit is automatically output and read according to the use environment of the apparatus so that the abnormal image can be dealt with before the occurrence.
An abnormality detection image in which an abnormal image due to a charging unit is likely to occur is automatically output and read according to the use environment of the apparatus. The input image and the output image are compared to determine whether an abnormal image has occurred. If it has occurred, rank it, notify the user, administrator, and support center via the network, and replace the charging unit etc. before appearing as an abnormal image in the image during normal use Prompt.
[Selection] Figure 1

Description

  The present invention relates to an image forming apparatus, and more particularly to an image forming apparatus capable of detecting an abnormality of a charging unit before occurrence of an abnormality in an image.

  The charging process in the electrophotographic apparatus is a process for uniformly charging a photoconductor, that is, a special dielectric that is a latent image carrier. As described above, there are roughly two methods for charging the photosensitive member: non-contact charging and contact charging. Among the charging methods generally used at present, there are a corona charging system represented by a corotron charging system and a scorotron charging system which are non-contact charging systems. However, since corona charging system chargers generate ozone, in recent years, due to environmental restrictions, the low-to-medium speed electrophotographic apparatus is contacted by roller chargers and brush chargers that generate less ozone. Its mainstream is shifting to electrification. In the scorotron charger, a grid is provided in the vicinity of the wire through which the current flows, and in the roller charger, AC is superimposed on the DC to aim for more uniform charging.

  In Patent Document 1, there is a description that an input image and an output image are divided into n and pattern matching is performed for each divided block to perform image color misregistration correction and color correction. Only the current quality of the forming apparatus can be grasped, and it cannot be predicted that an abnormal image such as a color shift will occur during normal use.

  In addition, Patent Document 2 describes that an abnormal image detection chart is read by an image reading device to specify whether the cause of an abnormal image such as skew is on the printer side or the reading side. Only the current quality can be grasped, and it cannot be predicted that an abnormal image such as a color shift will occur during normal use.

JP 2004-345091 A JP 2005-176045 A

  However, the following problems remain in the charging process. In other words, in non-contact charging or contact charging, a portion of the photosensitive member, such as a wire or a roller, that is directly charged to the photosensitive member is subject to defective charging due to discharge or dirt over time. Appears as a line. It is difficult to recover a portion that has once been poorly charged, and in many cases, this causes the life of the unit to which the charging unit is attached. When an abnormal image due to charging failure occurs, a normal image cannot be obtained. In addition, in order to prevent abnormal images due to defective charging, it is necessary to determine the lifetime of the unit with a certain margin, so that the lifetime cannot be used to the maximum and the cost is increased.

  SUMMARY An advantage of some aspects of the invention is that it provides an image forming apparatus that can sufficiently avoid the above problems.

  The image forming apparatus according to claim 1 includes an image input unit, an image forming unit that forms an output image on a recording medium based on input image data input from the image input unit, and an image formed by the image forming unit. A discharge unit for discharging a recorded recording medium, an image reading unit for outputting read image data obtained by reading the discharged recording medium, and an abnormal image due to the charging unit of the image forming unit are likely to occur. An anomaly detection image generating means for outputting anomaly detection image data, and the image reading obtained by reading a recording medium on which an output image is formed based on the anomaly detection image data generated by the anomaly detection image generating means A comparison means for comparing the output image data from the means and the inputted abnormality detection image data and outputting a determination result, and based on the determination result of the comparison means It characterized by having a detectable determination means the presence or absence of abnormality of the serial charging unit.

  According to a second aspect of the present invention, in the image forming apparatus according to the first aspect, the method of generating the abnormality detection image data by the abnormality detection image generating unit is a difference between a photoreceptor surface potential and a developing bias. Including a method of generating by changing the background potential, and an abnormality of the charging unit can be detected before an abnormality caused by the charging unit occurs in an output image formed on a recording medium.

  According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect, the comparison unit divides the abnormality detection image data and the output image data from the image forming unit into a plurality of blocks. The comparison is performed by pattern matching for each divided block.

  According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the abnormality detection image data generating means converts the abnormality detection image data into temperature and humidity at a place where the image forming apparatus is installed, The abnormality detection image data is output at an output time determined based on a use environment including a color ratio and the number of output sheets.

  According to a fifth aspect of the present invention, in the image forming apparatus according to any one of the first to fourth aspects, the image reading unit is configured to output the recording medium formed on the basis of the abnormality detection image data. It is characterized by automatically reading an image recorded on a recording medium.

  According to a sixth aspect of the present invention, in the image forming apparatus according to any one of the first to fifth aspects, the image forming apparatus includes a communication unit that transmits to at least one of a user, a device manager, and a service center via a network. The comparison means includes conversion means for converting the determination result into a numerical value corresponding to the degree of abnormality, and the communication means outputs a numerical value converted by the conversion means output from the comparison means to a predetermined value. In this case, at least one of the read image data, the determination result, and the numerical value is transmitted to at least one of a user, a device manager, and a service center via the network.

  According to a seventh aspect of the present invention, in the image forming apparatus according to the sixth aspect, the communication unit makes at least a service call as a notification of a determination result by the determination unit.

  According to an eighth aspect of the present invention, in the image forming apparatus according to the sixth or seventh aspect, when the display unit includes a display unit and the determination result by the determination unit is a predetermined value, the information regarding the determination result is displayed in the display unit. It is characterized by displaying on a means.

  According to a ninth aspect of the present invention, in the image forming apparatus according to any one of the first to eighth aspects, an abnormal image caused by charging various values contributing to image formation including a background potential value based on the determination result. The value is automatically reset to a value that is unlikely to appear, and abnormal images due to charging are unlikely to occur in images during normal use until the charging unit or the unit that comes with the charging unit is replaced. And a resetting means for performing the resetting.

  According to a tenth aspect of the present invention, in the image forming apparatus according to any one of the first to ninth aspects, the abnormality detection image generating means is not charged for the output image generated for the abnormality detection image. Is described in a recording medium.

  According to an eleventh aspect of the present invention, in the image forming apparatus according to any one of the sixth to tenth aspects, the charging unit or the device unit to which the charging unit is attached includes an information recording medium and the determination result as the information. A means for writing to a recording medium is provided.

  According to a twelfth aspect of the present invention is the image forming apparatus according to the eleventh aspect, further comprising a reading unit that reads a comparison result written on the information recording medium.

  According to a thirteenth aspect of the present invention, in the image forming apparatus according to the twelfth aspect, based on the comparison result obtained by the reading unit, information on the charging unit or a unit to which the charging unit is attached is displayed on the display unit. It is characterized by displaying.

  According to a fourteenth aspect of the present invention, in the image forming apparatus according to any one of the first to thirteenth aspects, the discharge unit and the image reading unit are arranged close to each other.

  According to a fifteenth aspect of the present invention, in the image forming apparatus according to any one of the first to fourteenth aspects, the output image is read immediately before or after the medium is discharged by the discharge unit.

  In the image forming apparatus using the abnormal image detection method of the present invention, before the abnormal image due to the charging unit is generated during normal use, the occurrence of the abnormal image due to the charging unit is predicted to recover the abnormal image. It is possible to secure time for replacing the charging unit for charging or the unit to which the charging unit is attached. In addition, by detecting abnormal images caused by charging units that have a significant effect on the life of the unit, the life of the charging unit or the unit attached to the charging unit can be used to the maximum and the costs associated with unit replacement can be reduced. It is also possible to do.

  In the embodiment of the present invention, an abnormality detection image in which an abnormal image due to the charging unit is likely to occur is automatically output and read according to the use environment of the apparatus. Then, the input image and the output image are compared, and it is determined whether or not an abnormal image due to the charging unit has occurred in the image. If an abnormal image has occurred, rank the degree, notify the user, administrator, support center via the network according to the rank, the charging unit before appearing as an abnormal image in the image during normal use, Or make it possible to replace the unit with the charging unit.

  Furthermore, depending on the result of the discrimination, it is possible to automatically reset to a setting where abnormal images due to the charging unit are unlikely to occur, such as widening the ground potential, and to reduce the downtime until the unit replacement to zero as much as possible. To do.

  In addition, abnormal images are generated before abnormal images occur in normal use by outputting images that are likely to generate abnormal images due to the charging unit while changing the background potential in steps in the abnormal detection image. It is possible to predict the possibility of

  In addition, by having a means to grasp the unit status, it is possible to grasp the life of the unit, which has been roughly determined in the past, for each device and individual unit, and to reduce the costs associated with unit replacement. Also possible.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. A copying machine 10 as an illustrated image forming apparatus mainly includes a reading unit 11 that reads a document, a paper feeding unit 12 that stores and supplies transfer paper on which an image of the document is formed, and a document that is read by the reading unit 11. An image forming unit 13 that forms a toner image based on the image data of the image, a transfer unit 14 that transfers the toner image formed by the image forming unit 13 to a transfer sheet, a fixing unit 15, and a toner image are formed. And a paper discharge unit 16 for discharging the paper.

  The image forming unit 13 includes four photoconductors 21 that are image carriers that rotate in a predetermined direction (arrow direction), a charging roller 22 that is arranged around each photoconductor 21 and constitutes a charging unit, A writing section 23 for forming a latent image by irradiating the photosensitive member 21 with a laser beam, four developing rollers for developing the latent image with a toner into a visible image, a charge eliminating section, and a cleaning section; Have Each image forming unit 13 includes image forming stations (Y station, C station, M station, and Bk station) that respectively form yellow, cyan, magenta, and black toner images.

  The transfer unit 14 includes an intermediate transfer belt 25 as a transfer member, a roller 26 that drives the intermediate transfer belt 25 so that the intermediate transfer belt 25 is fed in synchronization with the rotation of each photosensitive member 21 at a contact portion (primary transfer portion), and 2 A surface potential sensor 27 as a detecting means for detecting the surface potential of the toner layer on the intermediate transfer belt 25 in the vicinity of the next transfer portion. The secondary transfer portion is a portion that transfers a toner image onto a transfer sheet (not shown) conveyed between the intermediate transfer belt 25 and the transfer roller 28.

  The copying machine 10 uniformly charges each photoconductor 21 and forms an electrostatic latent image on each photoconductor 21 by LD (or LED) light from the writing unit 23. The formed electrostatic latent image is converted into a toner image by the developing unit 15, and the toner image is transferred from the photoreceptor 21 to the transfer member at the primary transfer unit. Then, after being transferred from the transfer member onto the transfer paper at the secondary transfer portion, it is fixed onto the transfer paper at the fixing portion 15.

  The service person outputs an abnormality detection image at an arbitrary time and reads the image with the reading unit 11 automatically or manually. The abnormality detection image output at this time is temporarily set and output under a condition that an abnormal image due to the charging unit is likely to be generated, for example, by changing the background potential which is the difference between the surface potential of each photoconductor 21 and the developing bias. Is done. Thus, by comparing the image data input by the reading unit 11 with the image data formed by the image forming unit, the possibility of the occurrence of an abnormal image due to the charging unit during normal use is detected. It is possible to do.

  The abnormality detection image output time may be any time, but an appropriate output time can be automatically determined according to the environment in which the image forming apparatus is installed and the use situation. In addition, the abnormality detection image output here may be excluded from charging (price collected for one or more times of image formation called performance charge or the like).

  The images read in this way rank the degree of abnormality on the device side, inform the service center via the network of the read contents, and a service person visits based on this, or displays on the device display or PC It is possible to display abnormality prediction information on the driver. Since transmission / reception of data using a network is well known, illustration is omitted.

  In addition, for example, when the unit itself such as the image forming unit 13 has an information recording medium, by storing the information ranked as described above in this medium, Even if the unit is attached to another device, the state of the unit itself can be notified to the device.

  On the other hand, if the abnormality detection image is read here and it is predicted that an abnormality will occur in the near future, it is temporarily set to an imaging condition in which an abnormal image due to charging is unlikely to occur until the predicted time, and the device is used. Can be continued.

  An example of image formation conditions for an anomaly detection image will be described. In addition, although the example demonstrated below is an image output for abnormality detection by changing a background potential, this invention is not limited to this example.

  First, when outputting an abnormality detection image, the charging DC / development bias at the time of image formation or the fixed value charging DC / development bias used at that time is basically used. As an example, the developing bias (Vb) during normal image formation is −700 V, the charging DC bias (Vc) is −840 V, and the charging DC bias setting value is set to a value 140 V lower than the developing bias setting value. It shall be 140V. Then, if writing is not performed with the developing bias (Vb) = − 700 V and the charging DC bias (Vc) = − 840 V, the portion is naturally blank. From the leading edge of the image area, the charging DC bias (Vc) is first gradually increased from −840V to −820V, −800,. Then, the conceptual diagram of the image area is as shown in FIG. 2, and areas having different background potentials are formed stepwise in one sheet of A3 size paper.

  Although the above example is a case where no writing is performed, the bias setting is similarly performed for the case where the entire halftone such as 2by2 is written. In this case, regions having different background potentials are formed stepwise in the entire halftone image.

  Next, the determination means and ranking of the abnormality detection image will be described. The abnormality detection image output as described above is roughly classified into three means: a method of reading the output paper with a scanner, a method of visually judging the output paper by a serviceman, and the like on the image carrier. There is a method for detecting an image with a sensor. Here, a method of reading with a scanner will be described as an example, but the present invention can of course be implemented using other methods.

  First, the abnormality detection image output on the paper as described above is read by a scanner. It is assumed that the image is determined using a determination unit including, for example, a microcomputer built in the copying machine 10 and software having a required function. In the determination, first, for example, numbers from the one with the higher ground potential like numbers 1 to 6 described on the right edge in FIG. 2 are given, and then the image for each area is determined for the read image. Move. At this time, in the order of numbers 1 to 6, it is assumed that the vertical color streak is likely to occur due to the charging roller contamination, and the charging roller has a possibility of generating a color streak in the future image forming process. If it is assumed that color streaks are generated in the subsequent areas, the areas after the number 4 are detected and judged by a pattern matching method, for example. After that, if the near-end threshold of the charging unit life is set to generate color streaks in the area of number 4, an alert is displayed on the display unit of the copying machine 10 or connected to the network. If so, a near-end notification operation such as reporting to other terminals via the network may be performed. Of course, the method, equipment, and the like used for the determination are not limited to the above examples, and various methods can be adopted.

  That is, as described above, an abnormality detection image that is likely to cause an abnormal image due to the charging unit is automatically output and read according to the use environment of the apparatus, thereby comparing the input image and the output image, It is determined whether or not an abnormal image due to the charging unit has occurred in the image, and if so, the degree of the abnormal image that has occurred is ranked, and the user, administrator or support center is ranked according to the rank. You can replace the charging unit or the unit that comes with the charging unit before it appears as an abnormal image in the normal use image, but depending on the result of the discrimination, the background potential may be expanded. For example, it automatically resets the settings so that abnormal images caused by the charging unit are unlikely to occur, reducing the downtime until the unit is replaced. It is possible to Rinaku 0. Furthermore, abnormal images are generated before abnormal images are generated in normal use by outputting images that are likely to generate abnormal images due to the charging unit while gradually changing the background potential in abnormal detection images. It is possible to predict the possibility of Furthermore, by having a means that can grasp the status of the unit, the life of the unit, which has been roughly determined in the past, can be grasped by individual devices and individual units, thus reducing the costs associated with unit replacement. Is possible.

  That is, by using the image forming apparatus having the abnormal image detection method of the present invention, the occurrence of an abnormal image due to the charging unit is predicted before the abnormal image due to the charging unit is generated during normal use. It is possible to secure time for replacing the charging unit for recovering the abnormal image or the unit to which the charging unit is attached. In addition, by detecting abnormal images caused by charging units that have a major impact on the life of the unit, the life of the charging unit or the unit attached to the charging unit can be used to the maximum, and the costs associated with unit replacement can be reduced. It is also possible to do.

Sectional drawing which shows an example of the image forming apparatus (copy machine) used as the application object of this invention Conceptual diagram of an image area in which areas with different ground potentials are formed in stages on a sheet of paper

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Copy machine 11 Reading part 12 Paper feeding part 13 Image forming unit 14 Transfer unit 15 Fixing part 16 Paper discharge part 21 Photoconductor 22 Charging roller 23 Writing part 24 Developing roller 25 Intermediate transfer belt 26 Roller 27 Surface potential sensor 28 Transfer roller

Claims (15)

An image input unit, an image forming unit that forms an output image on a recording medium based on input image data input from the image input unit, and a recording medium on which an image is recorded by the image forming unit An abnormality detection unit that outputs image data for discharging, an image reading unit that outputs read image data obtained by reading the discharged recording medium, and anomaly detection image data that is likely to cause an abnormal image due to the charging unit of the image forming unit Output image data from the image reading means that has read the recording medium on which an output image is formed based on the image data for image generation, the image data for abnormality detection generated by the image generation means for abnormality detection, and the input Comparing means for comparing the abnormality detection image data and outputting a determination result, and determining whether the charging unit is abnormal based on the determination result of the comparison means. Image forming apparatus characterized by having knowledge possible judgment means. The image forming apparatus according to claim 1, wherein the abnormality detection image generation unit generates the abnormality detection image data by changing a background potential that is a difference between a photoreceptor surface potential and a developing bias. An image forming apparatus, comprising: a method for detecting an abnormality of the charging unit before an abnormality caused by the charging unit occurs in an output image formed on a recording medium. 3. The image forming apparatus according to claim 1, wherein the comparison unit divides the abnormality detection image data and the output image data from the image formation unit into a plurality of blocks, and a pattern is formed for each of the divided blocks. An image forming apparatus that performs comparison by matching. 4. The image forming apparatus according to claim 1, wherein the abnormality detection image data generating unit includes the abnormality detection image data including a temperature / humidity of a place where the image forming apparatus is installed, a color ratio, and the number of output sheets. 5. An image forming apparatus that outputs the abnormality detection image data at an output time determined based on an environment. 5. The image forming apparatus according to claim 1, wherein the image reading unit displays an image recorded on the recording medium when the recording medium formed based on the abnormality detection image data is discharged. An image forming apparatus characterized by being automatically read. 6. The image forming apparatus according to claim 1, further comprising a communication unit that transmits to at least one of a user, a device manager, and a service center via a network, and the comparison unit includes the determination result. Is converted into a numerical value corresponding to the degree of abnormality, and the communication means reads the read image data and the determination result when the numerical value converted by the converting means output from the comparing means is a predetermined value. An image forming apparatus, wherein at least one of the numerical values is transmitted to at least one of a user, a device manager, and a service center via the network. The image forming apparatus according to claim 6, wherein the communication unit performs at least a service call as a notification of a determination result by the determination unit. 8. The image forming apparatus according to claim 6, further comprising a display unit, wherein when the determination result by the determination unit is a predetermined value, information regarding the determination result is displayed on the display unit. Image forming apparatus. 9. The image forming apparatus according to claim 1, wherein various values that contribute to image formation including a background potential value are automatically set to values that are unlikely to cause an abnormal image due to charging based on the determination result. Resetting means for resetting and setting so that an abnormal image due to charging is unlikely to occur in an image during normal use until the charging unit or the unit to which the charging unit is attached is replaced. An image forming apparatus. 10. The image forming apparatus according to claim 1, wherein the abnormality detection image generation unit records on the recording medium that the output image generated for the abnormality detection image is not charged. An image forming apparatus. 11. The image forming apparatus according to claim 6, wherein the charging unit or the device unit to which the charging unit is attached includes an information recording medium and a unit for writing the determination result to the information recording medium. An image forming apparatus. 12. The image forming apparatus according to claim 11, further comprising a reading unit that reads a comparison result written on the information recording medium. 13. The image forming apparatus according to claim 12, wherein information on the charging unit or a unit to which the charging unit is attached is displayed on the display unit based on a comparison result obtained by the reading unit. Image forming apparatus. 14. The image forming apparatus according to claim 1, wherein the discharge unit and the image reading unit are arranged close to each other. 15. The image forming apparatus according to claim 1, wherein an output image is read immediately before or after the medium is discharged by the discharge unit.