JP2012103371A - Recording material conveyance failure prediction device, image forming apparatus, and state management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a recording material conveyance failure prediction device that predicts the occurrence of recording material conveyance failure before the actual occurrence of the failure, which is due to deterioration of a conveyance member for conveying recording materials from a registration mechanism to a transfer part; and carries out necessary treatment such as maintenance before the occurrence of conveyance failure, as well as an image forming apparatus, and a state management system.SOLUTION: A recording material conveyance failure prediction device includes a tip detection sensor 128 that is tip detection means for detecting a tip of a recording sheet in a conveyance direction in a recording sheet conveyance section, which is from a pair of registration rollers 49 to a secondary transfer nip; and measures time T1, which is from the initiation of a toner image forming by a tandem part 20 to the detection of a tip of a recording sheet by the tip detection sensor 128, to predict conveyance failure of the recording sheet based on the measured time T1.

Description

  The present invention relates to a recording medium conveyance failure prediction apparatus, an image forming apparatus, and a state management system.

  An image forming apparatus that forms an image on a recording sheet by transferring the toner image formed by the image forming unit onto a recording sheet that is a recording medium conveyed along the conveying path from the recording medium stacking unit and then fixing the toner image. Are known. Specifically, the recording sheets fed one by one from the recording material stacking unit are conveyed toward the registration roller pair through the conveyance path by the conveyance force of the conveyance roller pair. The recording paper that is nipped and conveyed by the conveying roller pair temporarily stops when the leading edge abuts against the nip portion of the registration roller pair. The registration roller pair starts driving in accordance with the timing at which the toner image formed by the image forming unit reaches the transfer unit, and feeds the recording paper toward the transfer unit. The recording paper on which the toner image has been transferred at the transfer section is conveyed to a fixing nip that is a contact portion between a fixing roller as a fixing member and a pressure roller as a pressure member, and the toner image on the recording paper is transferred to the recording paper at the fixing nip. To be established.

  In the fixing nip for fixing the toner image on the recording paper, the toner image is softened by heating and its adhesiveness is increased, so that the recording paper wraps around the fixing roller (hereinafter referred to as fixing wrapping) occurs. A conveyance failure such as clogging (hereinafter referred to as jam) may occur.

  For this reason, there is known an image forming apparatus in which a recording sheet that is about to be wound around a fixing roller is forcibly separated from the fixing roller by a separation claw close to the fixing roller. However, even with the separation claw, if the fixing roller loses its smoothness due to the use of the fixing roller over time (when it deteriorates), it will not be possible to maintain good releasability for the adhesive toner, The separation claw could not be peeled off, and there was a possibility that jamming with fixing wrapping occurred.

  Japanese Patent Application Laid-Open No. 2004-228688 detects image behavior sent from the exit of the fixing nip, determines the degree of deterioration of the fixing roller, and based on the result, forms an image that prompts the user to replace the fixing roller. An apparatus is described. If it becomes easier to wind the recording paper along with the deterioration of the fixing roller, the recording paper discharged from the fixing nip exit will not immediately move away from the fixing roller, but will follow the surface of the fixing roller. Start showing. When starting to show such behavior, by prompting the user to replace the fixing roller, it is possible to prevent in advance the occurrence of fixing wrap jam due to continued use of the deteriorated fixing roller.

  However, the cause of occurrence of winding of the fixing roller is not limited to deterioration of the fixing roller that is a member at the jam occurrence location. For example, if the conveying member for conveying the recording paper from the registration roller to the transfer unit deteriorates due to slippage at the time of start-up in the clutch for transmitting the driving force to the registration roller with use over time, the transfer unit transfers to the transfer unit. Delay in the arrival of the recording paper. As described above, when the recording paper arrives at the transfer portion with a delay, the image is transferred to a position shifted to the downstream side in the transport direction with respect to a predetermined position of the recording paper. When the conveyance member for conveying the recording paper from the registration roller to the transfer portion progresses and the recording paper reaches the transfer portion to some extent, the toner image adheres to the leading edge of the recording paper. End up. If there is a toner image at the leading edge of the recording paper, the leading edge of the recording paper will stick to the fixing roller, and the leading edge of the recording paper will enter the gap between the separation claw and the fixing roller located close to the fixing roller. In some cases, the separation function could not be demonstrated. As a result, fixing wrap jams occur.

  The present invention has been made in view of the above background, and its purpose is to predict the occurrence of a recording medium conveyance failure due to deterioration of the conveyance member that conveys the recording medium from the registration mechanism to the transfer unit. Another object of the present invention is to provide a recording medium conveyance defect prediction apparatus, an image forming apparatus, and a state management system capable of performing necessary processing such as maintenance before a conveyance defect occurs.

In order to achieve the above object, the invention of claim 1 includes a transfer unit that transfers a toner image formed by an image forming unit to a recording body conveyed along a conveyance path from a recording material stacking unit, Arranged on the upstream side of the transfer unit with respect to the transfer direction of the recording body, the recording body is transferred to the transfer section of the recording body so that the toner image formed by the image forming section reaches the transfer section at the timing when the toner image reaches the transfer section. Recording medium conveyance failure that predicts conveyance failure of a recording medium in an image forming apparatus comprising a registration mechanism that controls the feeding timing of the recording medium and a fixing section that fixes a toner image on the recording medium transferred by the transfer section In the prediction device, the leading edge detection means for detecting the leading edge in the conveyance direction of the recording medium in the recording medium conveyance section from the registration mechanism to the transfer section, and the leading edge detection means from the start of toner image formation in the image forming section. A time measuring unit that measures a time T1 until the leading edge of the recording material is detected, and predicting a conveyance failure of the recording material based on the time T1 measured by the time measuring device. .
According to a second aspect of the present invention, in the recording medium conveyance failure prediction apparatus according to the first aspect, sufficient measurement is repeatedly performed by the time measuring unit according to an image forming operation for forming an image on the recording body of the image forming apparatus. A measurement result storage means for storing the time T1 of the parameter; and a feature quantity calculation means for performing a statistical calculation on the set of the time T1 stored in the measurement result storage means to obtain a feature quantity, It is characterized in that a conveyance failure of the recording medium is predicted based on the feature amount.
According to a third aspect of the present invention, in the recording medium conveyance failure prediction apparatus according to the second aspect, the feature amount calculating means includes, as the feature amount, an average value, a weighted average value, an index value indicating variation, and a section frequency. At least one of the above, and a conveyance failure of the recording medium is predicted based on one or more feature amounts.
According to a fourth aspect of the present invention, in the recording medium conveyance failure prediction apparatus according to the second or third aspect, the feature amount calculating means performs a statistical calculation on the set of the times T1 to obtain a plurality of different feature amounts. And determining means for determining whether each feature quantity indicates a normal conveyance state or a conveyance defect, and assigns a predetermined weight to each determination result in the determination means. And determining the conveyance failure of the recording medium based on a majority decision of which one of the determination result indicating normality and the determination result indicating failure is greater using the value of the determination result after weighting. is there.
According to a fifth aspect of the present invention, in the recording medium conveyance failure prediction apparatus according to any one of the first to fourth aspects, the fixing portion is a contact portion between a fixing member and a pressure member, and the recording body is the fixing portion. An apparatus for predicting a conveyance failure of a recording medium, wherein a conveyance failure due to winding around a member is predicted.
According to a sixth aspect of the present invention, in the recording medium conveyance failure prediction apparatus according to any one of the first to fifth aspects, a plurality of image forming apparatuses are communicably connected to each other via a communication network, and each image forming apparatus is maintained and managed. The maintenance management apparatus is provided with means for predicting a conveyance failure of the recording medium based on the time measured by the time measuring means.
According to a seventh aspect of the present invention, there is provided a transfer unit that transfers the toner image formed by the image forming unit to a recording body that is conveyed along the conveyance path from the recording body stacking unit, and a recording body that is more than the transfer unit. The feeding timing of the recording medium to the transfer section is controlled so that the recording medium reaches the transfer section in accordance with the timing at which the toner image formed in the image forming section reaches the transfer section. A registration mechanism, a fixing unit for fixing the toner image on the recording material transferred by the transfer unit, a recording material conveyance failure prediction means for predicting a conveyance failure of the recording material, and a recording material conveyance failure are predicted. In the image forming apparatus provided with a notifying means for notifying that maintenance is necessary, the recording medium conveyance defect prediction apparatus according to any one of claims 1 to 6 is used as the recording medium conveyance defect prediction section. Things to do A.
According to an eighth aspect of the present invention, a plurality of image forming apparatuses and a management apparatus are communicably connected to each other via a communication network, and the image forming apparatus is transmitted from each image forming apparatus via the communication network. A status management system that manages the status of each image forming apparatus based on status data with a management device, wherein the management device is a recording material conveyance section from the start of toner image formation to a transfer unit The time T1 until the leading edge detection means for detecting the leading edge of the recording body arranged in the conveyance direction detects the leading edge of the recording body is received from each image forming apparatus, and based on the time T1, each of the image forming apparatuses If it is determined that there is a conveyance failure predicting unit that predicts a conveyance failure that predicts a conveyance failure of the recording medium, and the conveyance failure prediction unit predicts that a conveyance failure of the recording medium will occur, that effect It is characterized in that it has a notification processing unit that performs a notification process for knowledge.

  According to the present invention, the recording medium is conveyed from the registration mechanism to the transfer section by measuring the time T1 from the start of toner image formation in the image forming section until the leading edge detection means detects the leading edge of the recording medium. It is possible to detect whether or not a delay has occurred in the arrival of the recording medium at the transfer portion due to the deterioration of the conveying member. Thereby, based on the time T1, it is possible to predict a recording medium conveyance failure due to deterioration of the conveyance member that conveys the recording medium from the registration mechanism to the transfer unit. As a result, necessary processing such as appropriate maintenance can be performed before a recording medium conveyance failure occurs due to deterioration of the conveyance member that conveys the recording medium from the registration mechanism to the transfer unit.

1 is an explanatory diagram illustrating a schematic configuration of a copier according to an embodiment. FIG. 3 is an explanatory diagram showing a peripheral configuration of an intermediate transfer belt of a printer provided in the copier. FIG. 3 is an explanatory diagram showing a unit configuration of a process unit of a printer provided in the copier. FIG. 2 is a block diagram showing a system configuration of an electrical system of the copier. 6 is a timing chart showing exposure timings of respective colors of the copier, registration roller driving body timings, and detection timing of a leading edge detection sensor. (A) is frequency distribution figure of measurement time T1 at the time of normal. FIG. 6B is a frequency distribution diagram of the measurement time T1 when a sign of occurrence of fixing wrap jam appears. FIG. 2 is a schematic configuration diagram of an operation display unit of the copier. FIG. 5 is a flowchart for determining a sign of occurrence of fixing wrapping based on a discriminant. FIG. 2 is an explanatory diagram showing an example of a copier management system including the copier.

Hereinafter, an embodiment in which the present invention is applied to an electrophotographic copying machine as an image forming apparatus will be described.
FIG. 1 is an explanatory diagram showing an outline of the mechanism of the copying machine 601.
FIG. 2 is an explanatory diagram showing a schematic configuration of the printer unit 100 of the copying machine 601.
FIG. 3 is an explanatory diagram showing a schematic configuration of one process unit provided in the printer unit 100.
The copier 601 includes an image forming unit including a printer unit 100 and a paper feeding unit 200, a scanner 300, and an ADF (automatic document feeder) 400. The scanner 300 is attached on the printer unit 100, and the ADF 400 is attached on the scanner 300. The scanner 300 reads image information of a document placed on the contact glass 32 by a reading sensor (CCD in the present embodiment) 36, and reads the read image information by IPP (Image Processing) of the engine control unit 510 (see FIG. 4). Processor). Based on the image information received from the scanner 300, the engine control unit 510 controls four drum-shaped photoconductors 40K, 40Y, 40D, and the like by controlling lasers and LEDs (not shown) disposed in the exposure device 21 of the printer unit 100. Laser writing light L is irradiated toward 40M and 40C. By this irradiation, electrostatic latent images are formed on the surfaces of the photoconductors 40K, 40Y, 40M, and 40C, and the latent images are developed into toner images through a predetermined development process. In this specification, the subscripts K, Y, M, and C added after the reference numerals indicate members for black, yellow, magenta, and cyan.

In addition to the exposure device 21 as an exposure unit, the printer unit 100 includes primary transfer rollers 62K, 62Y, 62M, and 62C as a transfer unit, a secondary transfer device 22, a fixing device 25, a paper discharge device, and a toner supply device (not shown). Also, a toner disposal device is provided.
The paper feeding unit 200 includes an automatic paper feeding unit disposed below the printer unit 100 and a manual feeding unit disposed on a side surface of the printer unit 100. The automatic paper feed unit separates the three paper feed cassettes 44 arranged in multiple stages in the paper bank 43, the paper feed roller 42 for feeding out the recording paper as a recording medium from the paper feed cassette, and the fed out recording paper. A separation roller 45 and the like are sent to the paper feed path 46. Further, it also has a transport roller 47 for transporting the recording paper to the paper feed path 48 of the printer unit 100. On the other hand, the manual feed section includes a manual feed tray 51 and a separation roller 52 that separates recording sheets on the manual feed tray 51 one by one toward the manual feed path 53.

  A registration roller pair 49 is disposed near the end of the paper feed path 48 of the printer unit 100. The registration roller pair 49 is formed between the intermediate transfer belt 10 as the intermediate transfer body and the secondary transfer device 22 at a predetermined timing after receiving the recording paper sent from the paper feed cassette 44 or the manual feed tray 51. To the secondary transfer nip.

  In this copying machine, an operator sets a document on the document table 30 of the ADF 400 when copying a color image. Alternatively, after the ADF 400 is opened and a document is set on the contact glass 32 of the scanner 300, the ADF 400 is closed and the document is pressed. Then, a start switch (not shown) is pressed. Then, when a document is set on the ADF 400, the scanner 300 starts driving immediately after the document is conveyed on the contact glass 32 and then when the document is set on the contact glass 32. Then, the first carriage 33 and the second carriage 34 travel, and the light emitted from the light source of the first carriage 33 is reflected by the document surface and then travels toward the second carriage 34. Further, after being reflected by the mirror of the second carriage 34, it reaches the reading sensor 36 via the imaging lens 35 and is read as image information.

  When the image information is read in this way, the printer unit 100 rotates the other two support rollers while rotating one of the support rollers 14, 15, and 16 with a drive motor (not shown). Then, the intermediate transfer belt 10 that is an intermediate transfer member stretched around these rollers is moved endlessly. Further, laser writing as described above and a development process described later are performed. Then, while rotating the photoconductors 40K, 40Y, 40M, and 40C, black, yellow, magenta, and cyan single-color images are formed on them. These toners are sequentially superimposed and electrostatically transferred at the primary transfer nips for K, Y, M, and C where the photoreceptors 40K, 40Y, 40M, and 40C and the intermediate transfer belt 10 come into contact with each other, and the four-color superposed toners. Become a statue.

  On the other hand, the paper feed unit 200 operates one of the three paper feed rollers to feed the recording paper having a size corresponding to the image information, and feeds the recording paper to the paper feed path of the printer unit 100. Lead to 48. The recording paper that has entered the paper feed path 48 is sandwiched between the pair of registration rollers 49 and temporarily stops. Then, the intermediate transfer belt 10 and the secondary transfer roller 23 of the secondary transfer device 22 are brought into contact with each other at the appropriate timing. To the secondary transfer nip, which is a part. Then, in the secondary transfer nip, the four-color superimposed toner image on the intermediate transfer belt 10 and the recording paper are in close contact with each other in synchronization. Then, the four-color superimposed toner image is secondarily transferred onto the recording paper due to the influence of the transfer electric field formed at the nip, the nip pressure, etc., and becomes a full-color image combined with the white color of the paper.

  The recording paper that has passed through the secondary transfer nip is fed into the fixing device 25 by the endless movement of the conveying belt 24 of the secondary transfer device 22. Then, after the full color image is fixed by the action of the pressure applied by the pressure roller 27 of the fixing device 25 and the heating by the heating belt, the paper discharge tray 57 provided on the side surface of the printer unit 100 via the discharge roller 56. Discharged to the top.

  As shown in FIG. 2, the printer unit 100 includes a belt unit, a tandem unit 20 as an image forming unit that includes four process units 18K, 18Y, 18M, and 18C that form toner images of respective colors, a secondary transfer device 22, A fixing device 25 and the like are provided. The belt unit moves the intermediate transfer belt 10 stretched around a plurality of rollers endlessly while contacting the photoreceptors 40K, 40Y, 40M, and 40C. In the primary transfer nips for K, Y, M, and C where the photoreceptors 40K, 40Y, 40M, and 40C are brought into contact with the intermediate transfer belt 10, the intermediate transfer belt 10 is moved by the primary transfer rollers 62K, 62Y, 62M, and 62C. Is pressed from the back side toward the photoconductors 40K, 40Y, 40M, and 40C. A primary transfer bias is applied to the primary transfer rollers 62K, 62Y, 62M, and 62C by a power source (not shown). As a result, a primary transfer electric field for electrostatically moving the toner images on the photoreceptors 40K, 40Y, 40M, and 40C toward the intermediate transfer belt 10 is formed in the primary transfer nips for K, Y, M, and C. Has been. Conductive rollers 74K, 74Y, 74M, and 74C that are in contact with the back surface of the intermediate transfer belt 10 are disposed between the primary transfer rollers 62K, 62Y, 62M, and 62C, respectively. These conductive rollers 74 have a primary transfer bias applied to the primary transfer rollers 62K, 62Y, 62M and 62C applied to adjacent process units via the intermediate resistance base layer 11 on the back side of the intermediate transfer belt 10. It prevents the flow.

  The process units 18K, 18Y, 18M, and 18C support the photosensitive members 40K, 40Y, 40M, and 40C and several other devices as a single unit on a common support. Can be removed. Taking the process unit 18K for black as an example, this has a developing unit 61K as developing means for developing the electrostatic latent image formed on the surface of the photoreceptor 40K into a black toner image in addition to the photoreceptor 40K. ing. Further, it also has a photoconductor cleaning device 63K that cleans transfer residual toner adhering to the surface of the photoconductor 40K after passing through the primary transfer nip. In addition, there are a static elimination device (not shown) that neutralizes the surface of the photoreceptor 40K after cleaning, and a charging device that is a charging means (not shown) that uniformly charges the surface of the photoreceptor 40K after static elimination. The process units 18Y, 18M, and 18C for other colors have substantially the same configuration except that the color of the handled toner is different. The copying machine has a so-called tandem type configuration in which these four process units 18K, 18Y, 18M, and 18C are arranged so as to face the intermediate transfer belt 10 along the endless movement direction.

  As shown in FIG. 3, the process unit 18 includes a charging device 60 as a charging unit, a developing device 61 as a developing unit, a primary transfer roller 62 as a primary transfer unit, and a photoconductor cleaning around a photoconductor 40. The apparatus 63, the static elimination apparatus 64, etc. are provided. As the photosensitive member 40, a drum-shaped member is used in which a photosensitive organic layer is applied to a base tube made of aluminum or the like to form a photosensitive layer. However, an endless belt may be used. In addition, as the charging device 60, a charging device that rotates the charging roller of the charging device 60 to which a charging bias is applied while contacting the photoreceptor 40 is used. A scorotron charger or the like that performs a non-contact charging process on the photoreceptor 40 may be used.

  The developing device 61 develops a latent image using a two-component developer containing a magnetic carrier and a nonmagnetic toner. An agitating unit 66 that conveys the two-component developer accommodated in the inside while agitating and supplies the developer sleeve 65 to the developing sleeve 65, and development that transfers toner of the two-component developer attached to the developing sleeve 65 to the photoreceptor 40. Part 67.

  The stirring unit 66 is provided at a position lower than the developing unit 67, and is provided on the bottom surface of the two screws 68 arranged in parallel to each other, the partition plate 69 provided between the screws, and the developing case 70. A toner density sensor 71 and the like are included.

  The developing unit 67 includes a developing sleeve 65 that faces the photosensitive member 40 through the opening of the developing case 70, a magnet roller 72 that is non-rotatably provided inside the developing sleeve 65, a doctor blade 73 that approaches the developing sleeve 65, and the like. ing. The distance at the closest portion between the doctor blade 73 and the developing sleeve 65 is set to about 500 [μm]. The developing sleeve 65 has a non-magnetic rotatable cylindrical shape. In addition, the magnet roller 72 that is prevented from being rotated around the developing sleeve 65 has, for example, five magnetic poles N1, S1, N2, S2, and S3 in the rotation direction of the developing sleeve 65 from the position of the doctor blade 73. ing. Each of these magnetic poles applies a magnetic force to the two-component developer on the sleeve at a predetermined position in the rotational direction. As a result, the two-component developer sent from the stirring unit 66 is attracted and carried on the surface of the developing sleeve 65, and a magnetic brush is formed along the magnetic field lines on the sleeve surface.

  The magnetic brush is regulated to an appropriate layer thickness when passing through the position facing the doctor blade 73 as the developing sleeve 65 rotates, and then conveyed to the developing area facing the photoreceptor 40. Then, due to the potential difference between the developing bias applied to the developing sleeve 65 and the electrostatic latent image on the photoreceptor 40, it is transferred onto the electrostatic latent image and contributes to development. Further, as the developing sleeve 65 rotates, the developing sleeve 65 returns to the developing portion 67 again, and after being separated from the sleeve surface due to the influence of the repulsive magnetic field between the magnetic poles of the magnet roller 72, the developing sleeve 65 is returned to the stirring portion 66. In the stirring unit 66, an appropriate amount of toner is supplied to the two-component developer based on the detection result by the toner density sensor 71. The developing device 61 may employ a one-component developer that does not include a magnetic carrier, instead of the one that uses a two-component developer.

  As the photoconductor cleaning device 63, a system in which a cleaning blade 75 made of polyurethane rubber is pressed against the photoconductor 40 is used, but another system may be used. In order to improve the cleaning property, in this example, a cleaning device 63 having a contact conductive fur brush 76 whose outer peripheral surface is in contact with the photoreceptor 40 is rotatable in the direction of the arrow in the figure. A metal electric field roller 77 for applying a bias to the fur brush 76 is provided so as to be rotatable in the direction of the arrow in the figure, and the tip of the scraper 78 is pressed against the electric field roller 77. The toner removed from the electric field roller 77 by the scraper 78 falls on the collection screw 79 and is collected.

  The photoconductor cleaning device 63 having such a configuration removes residual toner on the photoconductor 40 with a fur brush 76 that rotates counterclockwise with respect to the photoconductor 40. The toner adhering to the fur brush 76 is removed by the electric field roller 77 to which a bias that rotates in contact with the fur brush 76 in the counter direction is applied. The toner adhering to the electric field roller 77 is cleaned by the scraper 78. The toner recovered by the photoconductor cleaning device 63 is brought to one side of the photoconductor cleaning device 63 by the recovery screw 79 and returned to the developing device 61 by the toner recycling device 80 for reuse. The static eliminator 64 includes a static elimination lamp or the like, and removes the surface potential of the photoreceptor 40 by irradiating light. The surface of the photoreceptor 40 thus neutralized is uniformly charged by the charging device 60 and then subjected to optical writing processing.

  Referring to FIG. 2 again, a secondary transfer device 22 is provided below the belt unit in the drawing. In the secondary transfer device 22, a transport belt 24 is stretched between two rollers 23 and moved endlessly. One of the two rollers 23 is a secondary transfer roller to which a secondary transfer bias is applied by a power source (not shown), and the intermediate transfer belt 10 and the conveyance belt 24 are sandwiched between the rollers 16 of the belt unit. It is out. Thus, a secondary transfer nip is formed in which both belts move in the same direction at the contact portion while contacting. On the recording paper fed from the registration roller pair 49 to the secondary transfer nip, the four-color superimposed toner image on the intermediate transfer belt 10 is secondarily transferred collectively under the influence of the secondary transfer electric field and the nip pressure, so that full color is obtained. An image is formed. The recording paper that has passed through the secondary transfer nip is separated from the intermediate transfer belt 10 and is conveyed to the fixing device 25 along with the endless movement of the belt while being held on the surface of the conveyance belt 24. Instead of the secondary transfer roller, secondary transfer may be performed by a transfer charger or the like.

  The surface of the intermediate transfer belt 10 that has passed through the secondary transfer nip approaches a support position by the support roller 15. Here, the intermediate transfer belt 10 is sandwiched between a belt cleaning device 17 that contacts the front surface (loop outer surface) and a support roller 15 that contacts the back surface. Then, after the transfer residual toner adhering to the front surface is removed by the belt cleaning device 17, it sequentially enters the primary transfer nip for K, Y, M, and C, and the next four-color toner The images are superimposed.

  The belt cleaning device 17 has two fur brushes 90 and 91. By rotating a plurality of raised brushes in contact with the intermediate transfer belt 10 in a counter direction with respect to the flocking direction, the transfer residual toner on the belt is mechanically scraped off. In addition, a cleaning bias is applied by a power source (not shown) to electrostatically attract and recover the scraped transfer residual toner.

  With respect to the fur brushes 90 and 91, the metal rollers 92 and 93 are rotating in the forward or reverse direction while being in contact with each other. Among these metal rollers 92 and 93, a negative polarity voltage is applied to the metal roller 92 located on the upstream side in the rotation direction of the intermediate transfer belt 10 by the power source 94. Further, a positive polarity voltage is applied to the metal roller 93 located on the downstream side by the power source 95. The tips of the blades 96 and 97 are in contact with the metal rollers 92 and 93, respectively. In such a configuration, the upstream fur brush 90 first cleans the surface of the intermediate transfer belt 10 with the endless movement of the intermediate transfer belt 10 in the direction of the arrow in the drawing. At this time, for example, when −400 [V] is applied to the fur brush 90 while −700 [V] is applied to the metal roller 92, first, the positive polarity toner on the intermediate transfer belt 10 is moved to the fur brush 90 side. Electrostatic transfer to The toner transferred to the fur brush side is further transferred from the fur brush 90 to the metal roller 92 due to a potential difference, and is scraped off by the blade 96.

  As described above, the toner on the intermediate transfer belt 10 is removed by the fur brush 90, but a lot of toner still remains on the intermediate transfer belt 10. These toners are negatively charged by a negative polarity bias applied to the fur brush 90. This is considered to be charged by charge injection or discharge. Next, by using the fur brush 91 on the downstream side to apply a positive polarity bias and perform cleaning, the toner can be removed. The removed toner is transferred from the fur brush 91 to the metal roller 93 due to a potential difference and scraped off by the blade 97. The toner scraped off by the blades 96 and 97 is collected in a tank (not shown).

  Most of the toner is removed from the surface of the intermediate transfer belt 10 after being cleaned by the fur brush 91, but a little toner is still left. The toner remaining on the intermediate transfer belt 10 is charged with a positive polarity by a positive polarity bias applied to the fur brush 91 as described above. Then, it is transferred to the photoconductors 40K, Y, M, and C by the transfer electric field applied at the primary transfer position, and is collected by the photoconductor cleaning device 63.

  In general, the registration roller pair 49 is often used while being grounded, but it is also possible to apply a bias for removing paper dust from the recording paper fed to the registration roller pair 49.

  A recording paper reversing device 28 (see FIG. 1) is provided below the secondary transfer device 22 and the fixing device 25 so as to extend in parallel with the tandem portion 20 described above. As a result, the recording paper that has undergone the image fixing process on one side is switched by the switching claw to the recording paper reversing device side, where it is reversed and enters the secondary transfer transfer nip again. Then, after the secondary transfer process and the fixing process of the image are performed on the other side, the sheet is discharged onto a discharge tray.

FIG. 4 is a block diagram showing the system configuration of the electrical system of the copying machine 601.
This electrical system includes a controller 501 that controls the entire image forming apparatus, an operation board 500 of the image forming apparatus connected to the controller 501, an HDD 503 that stores image data, and a communication control apparatus interface board 504 that communicates with the outside. , LAN interface board 505, FAX control unit 506, IEEE1394 board, wireless LAN board, USB board, etc. 507 connected to general-purpose PIC bus, engine controller 510, engine controller 510 connected to controller via PCI bus I / O control board 513 for controlling I / O of the image forming apparatus, scanner board (SBU: Sensor Board Unit) 511 for reading a copy document (image), and image light represented by image data The photosensitive drum Projecting upward (light writing) LDB composed (laser diode board) 512 and the like. The communication control device interface board 504 immediately notifies an external remote diagnosis device when a malfunction occurs in the device, enabling the service person to recognize the contents and situation of the abnormal part and repair it suddenly. Yes. In addition, it is also used for sending out the usage status of the device.

  A scanner 300 that optically reads an original scans the original with an original illumination light source, and forms an original image on the CCD 36. An original image, that is, reflected light of light irradiation on the original is photoelectrically converted by the CCD 36 to generate R, G, B image signals. The CCD 36 is a three-line color CCD that generates R, G, and B image signals of EVENch (even pixel channel) / ODDch (odd pixel channel) and uses it as an analog ASIC (Application Specific IC) of SBU (sensor board unit). input. The SBU 511 includes an analog ASIC and a circuit that generates drive timings for the CCD and analog ASIC. The output of the CCD 36 is sampled and held by a sample and hold circuit inside the analog ASIC, then A / D converted, converted into R, G and B image data, shading corrected, and output I / F (interface) At 520, the data is sent to the image data processor IPP via the image data bus.

  IPP is a programmable arithmetic processing means that performs image processing, separation generation (determination of whether an image is a character area or a photographic area: image area separation), background removal, scanner gamma conversion, filter, color correction, scaling, image processing , Perform gamma conversion and gradation processing. The image data transferred from the SBU 511 to the IPP is corrected for signal degradation (signal degradation of the scanner system) accompanying quantization into an optical system and a digital signal by the IPP, and is written in the frame memory 521.

  The controller 501 includes a ROM for controlling the CPU and the system controller board, a RAM as a working memory used by the CPU, a lithium battery, an NV-RAM with a built-in RAM backup and a clock, and a system controller board. An ASIC for controlling the CPU periphery, such as system bus control, frame memory control, and FIFO, and its interface circuit are mounted.

  The controller 501 has functions of a plurality of applications such as a scanner application, a facsimile application, a printer application, and a copy application, and controls the entire system. The input of the operation board 500 is decoded, and the setting of the system and the contents of the state are displayed on the display unit of the operation board 500. Many units are connected to the PCI bus, and image data and control commands are transferred in a time division manner by the image data bus / control command bus.

  The communication control device interface board 504 is a communication interface board between the communication control device and the controller 501. Communication with the controller 501 is connected by full-duplex asynchronous serial communication. The communication control device 522 is multi-drop connected according to the RS-485 interface standard. Communication with the remote management device 630 is performed via the communication control device interface board 504.

  The LAN interface board 505 is a communication interface board between the LAN and the controller 501 connected to the LAN 600, and has a PHY chip mounted thereon. The LAN interface board 505 and the controller 501 are connected by standard communication interfaces of a PHY chip I / F and an I2C bus I / F. Communication with an external device is performed via the LAN interface board 505.

  The HDD 503 is used as an application database that stores system application programs, printer unit, and device activation information of image forming process devices, and an image database that stores image data of read images and written images, that is, image data and document data. It is done. Both the physical interface and the electrical interface are connected to the controller through an interface conforming to ATA / ATAPI-4.

  The operation board 500 is equipped with a CPU, ROM, RAM, LCD, and ASIC (LCDC) for controlling key input. In the ROM, a control program for the operation board 500 that controls input reading and display output of the operation board 500 is written. The RAM is a working memory used by the CPU. Through communication with the controller 501, the panel is operated to input the system settings to be input by the user, and the display and input are controlled to display the system settings and status to the user.

  The K, Y, M, and C color write signals output from the work memory of the controller 501 are input to the LDB (Laser Diode control Board) K, Y, M, and C LD (Laser Diode) write circuits. . The LD write circuit performs LD current control (modulation control) and outputs the result to each LD.

  The engine control unit 510 is a process controller that mainly controls image creation for image formation, and includes a CPU, an IPP that performs image processing, a ROM that incorporates a program necessary to control copying and printout, and control thereof Required RAM and NV-RAM are installed. The NV-RAM is equipped with an SRAM and a memory that detects power-off and stores it in the EEPROM. The I / OASIC that also has a serial interface that sends and receives signals to and from other CPUs that perform control is a nearby I / O (counter, fan, solenoid, motor, etc.) on which an engine control board is mounted. ASIC for controlling The I / O control board 513 and the engine control unit 510 are connected via a synchronous serial interface.

  The I / O control board 513 is equipped with a sub CPU 517, and includes a temperature sensor, a potential sensor, a density sensor (P sensor) on the photoreceptor as a toner amount sensor, and optical sensors 81 and 82 as toner density sensors, and I / O control of the image forming apparatus including reading of detection signals of other various sensors, analog control, jam detection referring to detection signals of the recording paper sensor, and recording paper conveyance control is performed. The interface circuit 515 is an interface circuit with various sensors and actuators (motors, clutches, solenoids). The aforementioned optical sensors 81 and 82 are included in various sensors 516.

  The power supply unit PSU 514 is a unit that supplies power to control the image forming apparatus. When the main SW is turned on (closed), commercial power is supplied. The commercial AC is supplied from the commercial power source to the AC control circuit 540, and the AC control output controlled so as to be rectified and smoothed by the AC control circuit 540 is used to allow the power supply unit PSU 514 to generate a DC voltage necessary for each control board. Supply. The CPU of each control unit operates using a constant voltage generated by the power supply unit PSU.

  The engine control unit 510 is a control unit that controls the entire hardware of the copying machine, and includes a ROM that is a data storage unit that stores a control program, a RAM that is a data storage unit that stores calculation data, control parameters, and the like. It has a CPU as a means.

Next, features of the present embodiment will be described.
In a copying machine as an image forming apparatus, if a recording paper conveyance failure (hereinafter referred to as jam) occurs, printing cannot be continued until the jam processing operation is completed, which causes a serious problem. In addition, the cause of the jam is due to improper use of the recording paper, bending, folding, wrinkling, or other usage of the recording paper, deterioration of the conveyance roller, motor, solenoid, clutch, etc. When the mechanical parts need to be repaired such as a deterioration failure of the drive parts, the process is divided into two. Since the user cannot distinguish between the two cases, it is often the case that when a jam occurs at the same high frequency, it is determined that repair is necessary and maintenance is requested from a service window. Therefore, the user had the problem of repeatedly encountering jams and losing valuable work time until recognizing that maintenance was necessary.

  In an electrophotographic image forming apparatus, in a fixing nip for fixing a toner image on a recording paper, the toner image is softened by heating to increase its adhesiveness. Therefore, the recording paper to the heating belt 26 as a fixing member is used. May be jammed due to winding (hereinafter referred to as fixing winding). In addition to the deterioration of the heating belt 26 that is a member at the jam occurrence position, such a fixing wrap jam is, for example, a recording paper conveyance delay between the registration roller pair 49 and the secondary transfer nip that is a transfer portion ( This also occurs when a resist delay occurs. Therefore, the heating belt 26 where the jam has occurred may not immediately become the cause of failure. As a result, trial and error in repair using the expertise of the customer engineer was required before the cause was identified and the maintenance was completed, resulting in time loss. In addition, although the cause of the fixing wrap jam is erroneously determined as the deterioration of the heating belt 26 in spite of the resist delay, unnecessary part replacement has occurred.

The registration delay is caused by the following problems. When the drive unit that drives the registration roller 49 has a clutch, slippage at the time of starting the clutch occurs due to deterioration of the clutch, and registration delay occurs. Further, when a stepping motor is used as the drive source of the registration roller driving unit, registration delay occurs when a step-out occurs at startup. In addition, registration delay occurs due to slipping of the recording paper at the start-up due to a decrease in gripping force caused by paper dust contamination of the registration roller 49 or the like. Furthermore, due to a decrease in the conveyance speed due to wear of the conveyance roller upstream of the registration roller 49 in the recording sheet conveyance direction, the conveyance load of the recording sheet conveyed from the registration roller 49 is increased, thereby causing a registration delay. To do. Further, in order to reduce the transport load of the upstream transport roller in the recording paper transport direction with respect to the registration roller 49, a clutch is provided in the upstream transport roller drive unit, and in the transport from the registration roller 49 to the secondary transfer nip, the clutch is disengaged. In the configuration in which the upstream conveying roller is brought with the recording paper, a registration delay occurs due to an increase in rotational load when the clutch is turned off due to dirt or the like.
As described above, when the recording paper is conveyed from the registration roller 49 to the secondary transfer nip on the upstream side of the registration roller 49 and the registration roller 49 in the sheet conveyance direction, a conveyance force is applied to the recording paper. This is caused by a tribological phenomenon such as wear and slip of each member constituting a conveyance roller that rotates around the recording paper and a drive unit that rotationally drives these. In many cases, a phenomenon in which the arrival of the transfer nip of the recording paper is delayed in millimeters with respect to an image due to one or a mixture of these factors occurs sporadically at a relatively low frequency.

  An electrophotographic image forming apparatus is always operated with a margin of a few millimeters in order to suppress fixing wrapping. When the registration of the recording paper is normally performed, a leading edge margin necessary for separation of the recording paper, that is, a width that is not bonded to the heating belt 26 by the toner is sufficiently secured as the image prohibition area. However, if the registration delay described above occurs and the arrival of the secondary transfer nip of the recording paper is delayed with respect to the image, an image is formed in the image prohibited area. If an image is formed in the image prohibition area at the leading edge of the recording paper, the leading edge of the recording paper sticks to the heating belt 26 and fixing wrapping occurs. In particular, when a high-density image called a solid image is formed in the image prohibited area, the above-described fixing wrap easily occurs. On the other hand, even if a resist delay occurs, an image may not be formed in the image formation prohibited area due to an image formed on the recording paper, and even if a resist delay occurs, fixing wrapping may not occur.

  As described above, the fixing wrapping due to the resist delay depends on the image formed on the recording paper. For example, office documents are mainly text, and usually there is almost no image data at the top of the image area. Therefore, even if registration delay occurs, an image is not formed in the image prohibition area of the recording paper, and fixing wrapping due to registration delay occurs only suddenly. However, when printing image data created with a presentation tool or the like, fixing wrapping jams frequently occur when a registration delay occurs. This is because an image created with a presentation tool or the like often has a dark background pattern for easy viewing when displayed on a projector, and when a registration delay occurs, a solid image is transferred to the image prohibited area. In fact, jamming with fixing occurs frequently. In recent years, electrophotographic printers have been used for on-demand printing applications. In such applications, high-density and strong impression printing using toner images may be performed on the entire surface. If there are too many resist delays, it will easily lead to jamming around the fixing relatively quickly. As described above, the frequency of occurrence of a fixing wrap jam due to a resist delay differs depending on the environment in which the image forming apparatus is used and the image to be printed. As described above, jamming frequently occurs or does not occur due to a registration delay depending on an image. Therefore, from the phenomenon of fixing winding jam, the registration roller, the roller on the upstream side in the sheet conveying direction from the registration roller, and these Only a skilled engineer who is experienced can recognize the failure of each member constituting the drive unit to be rotated. For this reason, when an inexperienced engineer performs a repair, an appropriate repair may not be performed, and it may take a lot of time to solve the problem, for example, causing the user to repeatedly fail.

  In addition, the problem that an image is formed in the image prohibition area at the leading edge of the recording paper due to a delay in registration has a possibility that the user can visually find it by observing the image formed on the recording paper. . However, there is no need to worry about misalignment of images in millimeters when printing office documents or presentation tools, so you will not notice them first. In print-on-demand applications, the user is also looking at image misalignment in millimeters, but if the frequency of occurrence is low, it will be overlooked unless the eyes of the monitor are strengthened to the extent that all are checked. In on-demand printing applications, an image is often formed at the leading edge of the image area. Therefore, before the image misalignment occurs to a level that can be visually confirmed, it becomes jammed around the fixing roll, and the recording paper is very If you do not observe the leading edge margin carefully, you will miss the sign of jamming due to resist delay. In exceptional cases, when an image is formed on a specific form preprinted with ruled lines or the like, the image position can be easily found visually, and image misalignment due to registration delay can be found. Therefore, in some cases, it is possible to detect a sign of jamming due to registration delay, but this places a great burden on the user.

  As described above, in the conventional image forming apparatus, it is difficult for a user or a service person to know a sign of a jam due to a registration delay. Most of the measures were taken.

  Therefore, in the present embodiment, as shown in FIG. 2, a leading edge detection sensor 128 as a leading edge detecting means for detecting the leading edge of the recording paper is provided in the recording paper conveyance path from the registration roller pair 49 to the secondary transfer nip. Yes. Then, the engine control unit 510 measures a time T1 from when the image forming operation is started until the leading edge detection sensor 128 detects the leading edge of the recording paper, and based on the time T1, the fixing winding due to the resist delay. Predict jams so that the cause of failure can be removed before wrapping jams occur frequently. Specific description will be given below.

FIG. 5 is a timing chart showing the exposure timing of each color, the driving body timing of the registration rollers 49, and the detection timing of the tip detection sensor 128.
As described above, in the present embodiment, the leading edge detection sensor 128 is provided in the recording paper conveyance section from the registration roller pair 49 to the secondary transfer nip. The engine control unit 510 serving as a time measurement unit starts time measurement when the K-color exposure is started, and measures a time T1 until the leading edge detection sensor 128 detects the leading edge of the recording paper. In measuring time, it is desirable to be able to measure image displacement with a resolution of 1 [mm] or less. For example, when the recording paper conveyance speed is 100 [mm / sec], the time resolution is set to be measured at 10 [msec] or less. This can be easily realized at today's CPU processing speed. In the above description, the time measurement start timing is set to the K color exposure start timing. However, the timing is not limited to this. For example, the C, M, and Y color exposure start timing and the K color exposure start timing have a delay of T2. Registration roller driving start timing that is driven in synchronization may be used. Further, the synchronization accuracy may be synchronized so that the leading edge margin can be evaluated. If the time resolution is 10 [msec], the synchronization accuracy may be 1 [msec]. Such time measurement is performed every time printing is performed, and the latest 1000 pieces of time measurement data are stored in a storage unit such as the HDD 503. Specifically, when new time data is acquired, among the 1000 time data stored in the HDD 503, the oldest time data is updated to the latest time data, so that the latest 1000 data is always obtained. The time measurement data can be stored in the HDD 503.

FIG. 6A shows the frequency distribution of the measurement time T1 at the normal time, and FIG. 6B shows the frequency distribution of the measurement time T1 when a sign of occurrence of fixing wrap jam appears.
As shown in FIG. 6A, the frequency distribution is very sharp when normal. On the other hand, as shown in FIG. 6B, there are a registration roller pair 49 and a conveyance roller pair that conveys the recording paper to the secondary transfer nip together with the registration roller 49 upstream of the registration roller pair 49 in the conveyance direction. When the wear deteriorates, a registration delay occurs in rare cases, and the leading edge detection sensor 128 detects the leading edge of the recording paper after the reference detection timing (the measurement time T1 is delayed from the reference). What is detected) will be observed.

  In this embodiment, the 1,000 time data stored in the HDD 503 is used to perform statistical calculation to obtain a feature amount, and based on the feature amount, a sign of fixing winding due to a resist delay is determined. Yes. Examples of the feature amount include an average value (moving average), an index value indicating variation such as standard deviation and variance, and the number of delays (section frequency) with respect to a reference value.

  In the determination of the sign by the average value, based on 1000 normal time measurement data, the calculated average value of the reference is stored in the storage unit, and the average value of the reference and the HDD 503 are stored. If the average value is more than a predetermined value with respect to the reference average value, a fixing wrap jam occurs due to a resist delay. Judge that there is a sign. Also, different weights may be applied to each of the 1000 pieces of measured time data, and a weighted average value may be used (weighted moving average). As the weighting of the time data, the weighting is performed so that the weight for the latest time data is the heaviest, and the weight is decreased as it gets older. The weight may be reduced linearly (linear weighted moving average) or the weight may be decreased exponentially (exponentially weighted moving average). If it is determined that there is a sign of fixing wrapping due to registration delay, the engine control unit 510 controls the operation board 500 via the controller 501, and, as shown in FIG. A message that prompts the engineer to request a service and a code (SC2120) indicating that a failure or a sign of failure of the registration roller or the conveyance roller upstream of the registration roller is detected are detected. When the user makes a service request, the customer engineer can prepare a replacement part before going to the site by transmitting the code displayed on the display unit 500a. It can be performed. In addition, since the customer engineer who performs maintenance management of the device only needs to know, when a sign is detected, a message is sent to the maintenance management information collection server via the network line, and the customer engineer or the operator who issues the command is notified to the terminal. Message display may be performed. Accordingly, it is preferable that maintenance is arranged without bothering the user.

  Further, the sign determination using the index value representing the variation of the time data T1 such as the standard deviation or the variance is performed as follows. That is, the standard deviation or variance is obtained by calculating the sum of squares of the difference between each measurement data and the average value. When this exceeds the reference value, it is determined that there is a sign of occurrence of fixing winding, and a message as shown in FIG. 7 is displayed on the display unit 500a. In addition, in order to increase the weight of occurrence of delay, calculation evaluation may be performed at the fourth power sum or higher order.

For the sign determination based on the number of delays with respect to the reference value, the delay upper limit value of the normal range is obtained in advance through experiments or the like and stored in the storage means. Then, among 1000 data stored in the HDD 503, the number of time measurement data deviating from the above upper limit value is counted, and when the number exceeds a certain number, it is determined that there is a sign of occurrence of fixing wrapping. A message as shown in FIG. 7 is displayed on the display unit 500a. It is desirable to adjust the normal range due to the influence of device geometrical variation and temperature. For this reason, accuracy can be improved and false alarms can be prevented by using an algorithm such as obtaining an average value from a certain amount of time measurement data and automatically updating the upper limit of the normal range delay based on this average value. It is suitable. For example, if a value that is + 1% of the moving average value of the latest 100 time measurement data is used as the upper limit value of the normal range, the upper limit value can be automatically updated. Further, the ratio of the number of times exceeding the upper limit value per 1000 time measurement data (hereinafter referred to as a delay rate) is calculated, and when the value is equal to or greater than a predetermined value, it is determined that there is a sign of occurrence of fixing winding. Also good.
If the upper limit is exceeded even once, it may be determined that there is a sign of occurrence of fixing wrapping. In this case, it is not necessary to store time measurement data in the HDD. That is, when the time is measured, it is determined that there is a sign of occurrence of fixing wrapping when the measured time data exceeds the upper limit value as compared with the upper limit value.

  Alternatively, a discriminant may be created using a machine learning algorithm or the like for a plurality of feature quantities such as an average value, standard deviation, and number of delays, and a sign of occurrence of fixing winding may be determined based on the discriminant. Thereby, it may be possible to issue an accurate message about the deterioration status of a specific member. For example, if the registration delay is caused by, for example, slipping of the clutch that connects the drive to the registration roller, the average value tends to be slightly delayed, and the standard deviation tends to increase due to increased variation each time. Moreover, the frequency of occurrence of delays tends to increase. By creating a discriminant function that comprehensively considers the situation of these feature quantities from the learning data using a machine learning algorithm, the above-described clutch deterioration can be reduced, such as a simple temperature change or a change in the average value due to a difference in the type of recording paper, or a variation change It becomes possible to distinguish and judge the resist delay due to the factor. Machine learning algorithms include boosting method and support vector machine method.

FIG. 8 is a control flowchart for determining a sign of occurrence of fixing wrapping based on the discriminant.
First, when one sheet is printed (YES in S1), the time T1 is measured (S2). When the time T1 is measured, the oldest time T1 (1000) is deleted from the time T1 (1) to T1 (1000) for the latest 1000 sheets stored in the HDD 503, and the time stored in the HDD 503 is one older. Change to time. Specifically, the latest time T1 (1) stored in the HDD 503 is set to the second time T1 (2), and the 999th time T1 (999) is updated to the oldest time T1 (1000). It is. Then, the data for the latest 1000 sheets is updated by substituting T1 measured this time for the latest time T1 (1) (S3). Next, four feature values are calculated using the updated T1 (1) to T1 (1000) (S4). That is, average value AV, variance D, 1% delay rate L, 10% delay rate LT. The function N in the delay rate arithmetic expression shown in S4 of FIG. 8 is a function for obtaining the number of elements that satisfy the conditions in parentheses. That is, it shows how many of T1 (1) to T1 (1000) were delayed by 1% or more or 10% or more of the average value.

  Next, a determination value F is calculated using these four feature amounts (S5). Specifically, the four feature amounts are compared with the respective reference values AVS, DS, LS, and LTS. The function S representing the comparison in the discriminant shown in S5 is a magnitude determination function that is 1 if the operation result in parentheses is 0 or more, and -1 if it is less than 0. This is multiplied by weights A1, A2, A3, and A4, respectively, multiplied by evaluation codes Sgn1 to Sgn4, and added to obtain a determination value F. The weights A1 to A4 are determined by the importance given to the entire determination result of the function S. The evaluation codes Sgn1 to Sgn4 are weighted so as to be positive if normal and negative if abnormal. More specifically, in the present embodiment, since any of the features is abnormal when the feature amount is larger than the reference value, in the case of abnormality, the value of the function S is 1 and becomes positive. Therefore, all Sgn1 to Sgn4 are -1. Conversely, when the value of the function S is 1, Sgn is 1 if it indicates normality. The reference values AVS, DS, LS, LTS, weights A1 to A4, and evaluation codes Sgn1 to Sgn4 can be determined by trial and error. However, a machine learning algorithm based on a boosting method is obtained by obtaining a reference data example. An appropriate value can be obtained quickly if it is determined by using this method, which is preferable.

  Next, when the obtained determination value F is “negative”, it is determined that there is a sign that fixing wrapping due to registration delay occurs as a comprehensive evaluation, and a message as shown in FIG. 7 is displayed (S7).

In the above description, a sign of fixing wrapping is detected in the copying machine, but a sign of fixing wrapping may be detected by a management device that performs maintenance management of the copying machine.
FIG. 9 is an explanatory diagram showing an example of a copier management system including a multi-function copier 601 that is an image forming apparatus.
A copier 601 that is an image forming apparatus and copiers 602 to 605 having functions equivalent to the copier 601 are connected by a LAN 600 and are connected from a gateway apparatus 610 to a management apparatus 630 outside the LAN via the Internet 620. Each copying machine transmits the latest measured time data T1 to the management device 630.

  The management apparatus 630 includes a database as a measurement result storage unit that accumulates time data T1 (1) to T1 (1000) of each copying machine, and receives the latest measured time data T1 sent from each copying machine. The oldest time data T1 (1000) of the corresponding copier is deleted from the database, the data of T (1) to T1 (999) stored in the database is updated to the oldest data, and the received measurement time data Is stored in the database as the latest time data T1 (1). Then, the management device 630 uses the 1000 pieces of time data including the latest received time data T1 (1) to calculate feature values such as an average value and variance, and based on the calculated feature values, It is determined whether or not there is a sign of fixing winding due to a resist delay of the copying machine. In this way, by adopting a configuration in which the algorithm after the feature amount calculation is performed in the management device 630, numerical values (for example, reference values AVS, DS, LS, LTS, weights A1 to 4, and evaluation codes Sgn1 to Sgn1 to 4 are used. ), The feature amount, the discriminant, and the like can be changed by the management device 630. Therefore, if a better judgment formula, a characteristic amount used for discrimination, a reference value, or the like is found than in the initial operation, the user can easily make a change without changing the device in use. Accordingly, when a sign of fixing winding due to a resist delay is positively detected based on a delicate determination criterion, the operational flexibility is increased, which is very suitable.

  When a sign is detected by the management device 630, a message is displayed on the terminal 640 serving as a notification processing means for the customer engineer or an operator who issues the command. Accordingly, it is preferable that maintenance is arranged without bothering the user.

As described above, according to the image forming apparatus of the present embodiment, the toner formed by the tandem unit 20 serving as the image forming unit on the recording sheet serving as the recording unit transported along the transport path from the paper feed cassette 44 serving as the recording unit stacking unit. Arranged on the upstream side of the recording paper conveyance direction from the secondary transfer nip, which is a transfer portion for transferring the image, the recording paper is secondary transferred in accordance with the timing at which the toner image formed in the tandem portion reaches the secondary transfer nip. A registration roller pair 49 as a registration mechanism for controlling the feeding timing of the recording paper to the secondary transfer nip so as to reach the nip; and a fixing nip for fixing the toner image on the recording paper transferred at the secondary transfer nip; It has. The image forming apparatus includes a leading edge detection sensor 128 serving as a leading edge detection unit that detects a leading edge in the conveyance direction of the recording paper in the recording paper conveyance section from the registration roller pair 49 to the secondary transfer nip, and toner image formation of the tandem unit 20. An engine having a function as time measuring means for measuring a time T1 from the start of an image until the leading edge detection sensor 128 detects the leading edge of the recording paper, and a function for predicting a recording paper conveyance failure based on the measured time T1. A recording medium conveyance failure prediction apparatus including a control unit 510 and the like is provided.
By having such a configuration, as described above, it is possible to detect a sign of occurrence of a fixing wrap jam due to a registration delay, and a registration unit pair 49, a driving unit that rotationally drives the registration roller, and a recording sheet 2 from the registration roller. When transporting to the next transfer nip, an appropriate transport roller on the upstream side in the transport direction relative to the registration roller pair 49 that imparts transport force to the recording paper or rotates with the recording paper and a drive unit that rotationally drives the transport roller Can be exchanged at any stage. Thereby, it is possible to suppress the occurrence of a jam due to a resist delay.

The image forming apparatus also includes an HDD 503 serving as a measurement result storage unit that stores the time T1 having a sufficient parameter that is repeatedly measured according to an image forming operation for forming an image on a recording sheet of the image forming apparatus, and functions as a feature amount calculation unit. The engine control unit 510 having the above performs a statistical calculation on the set of times T1 stored in the HDD 503 to obtain a feature amount, and predicts a conveyance failure of the recording medium based on the obtained feature amount. Examples of the feature amount include an average value, a weighted average value, an index value (variance, standard deviation, etc.) indicating variation, and an interval frequency (number of delays with respect to a reference value, delay rate, etc.).
As a result, the registration delay that occurs suddenly due to the usage method such as the folding of the recording paper is transferred to the secondary transfer nip from the registration roller, the driving unit that rotationally drives the registration roller pair 49 and the registration roller, and the recording paper. At this time, it is erroneously determined that the registration delay is caused by deterioration of the conveyance roller on the upstream side of the conveyance direction with respect to the registration roller pair 49 that applies the conveyance force to the recording paper or rotates with the recording paper, and the driving unit that rotationally drives the conveyance roller. Can be suppressed.

  The engine control unit 510 that also functions as a determination unit determines whether each feature value indicates a normal transfer state or a transfer failure, and assigns a predetermined weight to each determination result. In this case, the recording paper conveyance failure may be predicted based on the majority of the determination result indicating normality or the determination result indicating failure using the weighted determination result value. This makes it possible to accurately predict the fixing winding due to the resist delay. In some cases, it is also possible to accurately predict the deterioration state of a specific member.

  Further, means (feature amount calculation means) for predicting a recording paper conveyance failure is provided to a maintenance management apparatus 630 that is connected to a plurality of image forming apparatuses through a communication network so as to be communicable with each other and maintains each image forming apparatus. Or a discriminating means). As a result, when a better determination formula, a characteristic amount used for determination, a reference value, and the like are found than when initially operated, the user can easily change without using a device that is being used.

20: Tandem section 25: Fixing device 26: Heating belt 27: Pressure roller 44: Paper feed cassette 46: Paper feed path 47: Carriage roller 48: Paper feed path 49: Registration roller pair 51: Manual feed tray 52: Separation roller 53 : Paper feed path 128: leading edge detection sensor 500: operation board 500a: display unit 510: engine control unit 601: copier 630: management device T1: time data

JP 2007-108618 A

Claims (8)

A transfer unit that transfers the toner image formed by the image forming unit to the recording material conveyed along the conveyance path from the recording material stacking unit;
The transfer unit of the recording body is arranged upstream of the transfer unit in the recording medium conveyance direction so that the recording body reaches the transfer unit in accordance with the timing at which the toner image formed by the image forming unit reaches the transfer unit. A registration mechanism for controlling the feeding timing to
In a recording medium conveyance failure prediction apparatus for predicting a conveyance failure of a recording medium of an image forming apparatus including a fixing unit that fixes a toner image on the recording medium transferred by the transfer unit,
A leading edge detecting means for detecting a leading edge in the conveyance direction of the recording medium in a recording medium conveyance section from the registration mechanism to the transfer section;
A time measuring unit that measures a time T1 from the start of toner image formation in the image forming unit to when the leading edge detecting unit detects the leading edge of the recording body;
A recording medium conveyance failure prediction apparatus that predicts a conveyance failure of a recording medium based on a time T1 measured by the time measuring means. In the recording medium conveyance failure prediction apparatus according to claim 1,
A measurement result storage unit that stores the time T1 having a sufficient parameter that is repeatedly measured by the time measurement unit according to an image forming operation for forming an image on a recording body of the image forming apparatus;
A characteristic amount is obtained by performing a statistical calculation on the set of times T1 stored in the measurement result storage unit, and a feature amount calculation unit;
A recording medium conveyance failure prediction apparatus that predicts a conveyance failure of a recording medium based on the feature amount. In the recording medium conveyance defect prediction device according to claim 2,
The feature amount calculating means calculates at least one of an average value, a weighted average value, an index value indicating variation, and a section frequency as the feature amount,
A recording medium conveyance failure prediction apparatus that predicts a conveyance failure of a recording medium based on one or more feature amounts. In the recording medium conveyance failure prediction apparatus according to claim 2 or 3,
The feature amount calculating means performs a statistical calculation on the set of the time T1 to obtain a plurality of different feature amounts.
A discriminating means for discriminating whether each feature amount indicates a normal transport state or a transport failure,
Based on the majority decision of which one of the determination result indicating normality and the determination result indicating failure is greater by using a predetermined weighting for each determination result in the determination means and using the value of the determination result after the weighting , A recording medium conveyance failure prediction apparatus for predicting a conveyance failure of a recording medium. In the recording medium conveyance failure prediction apparatus according to any one of claims 1 to 4,
The fixing portion is a contact portion between the fixing member and the pressure member,
An apparatus for predicting a conveyance failure of a recording body, wherein the conveyance failure due to the recording body being wound around the fixing member is predicted. In the recording medium conveyance failure prediction apparatus according to any one of claims 1 to 5,
A maintenance management device connected to a plurality of image forming apparatuses so as to be communicable with each other via a communication network and predicting a conveyance failure of the recording medium based on the time measured by the time measuring means. An apparatus for predicting a conveyance failure of a recording medium, characterized in that means for carrying out the processing is provided. A transfer unit that transfers the toner image formed by the image forming unit to the recording material conveyed along the conveyance path from the recording material stacking unit;
The transfer unit of the recording body is arranged upstream of the transfer unit in the recording medium conveyance direction so that the recording body reaches the transfer unit in accordance with the timing at which the toner image formed by the image forming unit reaches the transfer unit. A registration mechanism for controlling the feeding timing to
A fixing unit for fixing the toner image on the recording material transferred by the transfer unit;
A recording medium conveyance defect prediction means for predicting a conveyance defect of the recording medium;
In an image forming apparatus provided with an informing means for informing that maintenance is necessary when a recording medium conveyance failure is predicted,
An image forming apparatus using the recording medium conveyance defect prediction device according to claim 1 as the recording medium conveyance defect prediction unit. A plurality of image forming apparatuses and a management apparatus are communicably connected to each other via a communication network, and each image forming is performed based on data relating to the state of the image forming apparatus transmitted from each image forming apparatus via the communication network. A state management system for managing the state of a device with a management device,
The management apparatus is configured to start from the toner image formation until the leading edge detection unit that detects the leading edge in the conveyance direction of the recording medium arranged in the recording medium conveyance section from the registration mechanism to the transfer unit detects the leading edge of the recording medium. A conveyance failure prediction unit that receives a time T1 from each image forming apparatus and predicts a conveyance failure of a recording body of each image forming apparatus based on the time T1, and a conveyance failure prediction unit If it is determined that there is a sign that a conveyance failure will occur, the state management system includes notification processing means for performing notification processing to notify that.

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