JP2016148787A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device that appropriately supplies a lubricant to a cleaning blade, and prevents warpage of the cleaning blade.SOLUTION: In an image formation device in which a photoreceptor drum 1 and intermediate transfer belt 6 are fixed to a device main body, a trestle including a secondary transfer belt 9 and a cleaning blade 96A eliminating a foreign matter on the secondary transfer belt 9 is insertable/drawable into/from the device main body, and on the secondary transfer belt 9, lubricant supply means is provided that supplies the lubricant, and a cleaning blade 96A scrapes the lubricant to thereby prevent warpage of the cleaning blade 96A, the image formation device comprises: a position detection sensor 97 that detects an attachment position of the trestle with respect to the device main body; and a correction unit that corrects a supply position by the lubricant supply means on the basis of a detection result of the position detection sensor 97.SELECTED DRAWING: Figure 4

Description

  The present invention relates to an image forming apparatus having a cleaning unit including a cleaning blade.

  In an electrophotographic color image forming apparatus, toner images of different colors are formed on a plurality of photosensitive drums, the formed toner images are primarily transferred onto an intermediate transfer belt and superimposed, and an intermediate transfer belt is further formed. The toner image is secondarily transferred from the toner to the paper.

  In such an image forming apparatus, a cleaning unit is provided for removing foreign matters (untransferred toner, paper powder, etc. remaining after image formation) on a member to be cleaned such as a photosensitive drum and an intermediate transfer belt. As the cleaning means, there is a means for removing a foreign matter on the object to be cleaned by bringing a flat cleaning blade made of an elastic body into contact with the surface of the object to be cleaned and rubbing the surface.

  Since the photosensitive drum and the intermediate transfer belt carry toner images, untransferred toner remains on these image carriers. On the other hand, since the secondary transfer belt transfers the toner image onto the conveyed paper and the secondary transfer belt itself does not carry the toner image, there is almost no untransferred toner on the secondary transfer belt. Since there is almost no untransferred toner and there is almost no foreign matter to be removed, it is generally unnecessary to provide a cleaning blade in the secondary transfer unit.

  On the other hand, in order to stabilize the density, there is an image forming apparatus that forms a density detection patch, detects the density of the patch formed using the density detection unit, and adjusts the density based on the detection result. In such an image forming apparatus, when the patch is transferred onto the intermediate transfer belt, the patch is transferred to an area outside the paper so that the patch is not transferred to the paper in the subsequent secondary transfer. The patch is later transferred directly to the secondary transfer belt. Therefore, the secondary transfer unit may be provided with a cleaning blade in order to remove the patch transferred to the secondary transfer belt.

  However, since the patch is formed only once for thousands of prints, the cleaning blade of the secondary transfer belt scrapes the toner less frequently than the cleaning blade of the photosensitive drum or the intermediate transfer belt scrapes the toner. . For this reason, in the cleaning blade of the secondary transfer unit, the toner at the edge of the cleaning blade that comes into contact with the secondary transfer belt tends to be lost because the toner is scraped less frequently. The toner adhering to the cleaning blade has the effect of reducing the frictional resistance between the cleaning blade and the secondary transfer belt. Therefore, if the amount of toner adhering to the cleaning blade is small, the friction between the cleaning blade and the secondary transfer belt will be reduced. The rubbing resistance increases and the cleaning blade is likely to be turned over.

  As means for preventing the cleaning blade from turning over, means for supplying a lubricant to the edge of the cleaning blade is known in order to reduce the frictional resistance between the cleaning blade and the secondary transfer belt.

  In the image forming apparatus disclosed in Patent Document 1, a supply patch (toner band supplied as a lubricant) is formed in an area between sheets when images are continuously formed on a sheet, and the shape of the supply patch is changed to a sheet size. This is set based on the information, the paper conveyance position information, and the detection result by the toner charge amount detection means.

JP 2011-53515 A

  However, in an image forming apparatus in which the secondary transfer unit is arranged on a pedestal that can be taken in and out of the apparatus main body, when the cradle is pulled out at the time of occurrence of jam (paper jam) or maintenance, and then the gantry is attached to the apparatus main body. In addition, the attachment position may deviate from the original position. Due to this displacement of the attachment position, the relative position of the supply patch with respect to the cleaning blade is shifted. At this time, if the supply patch to be supplied to the end portion in the longitudinal direction of the cleaning blade is shifted to the center side of the cleaning blade, a portion that does not scrape the supply patch is generated at the end portion of the cleaning blade. As a result, the cleaning blade is turned over.

  In view of the above circumstances, an object of the present invention is to provide an image forming apparatus that appropriately supplies a lubricant to a cleaning blade and prevents the cleaning blade from being turned up.

  In order to achieve the above object, an aspect of the present invention includes an image forming unit that forms a toner image, an image carrier that carries a toner image formed by the image forming unit, and an image forming unit and an image carrier. The apparatus main body includes a fixed apparatus main body, a transfer member that transfers a toner image onto a sheet, and a cleaning blade that contacts the transfer member and removes foreign matter on the transfer member as the transfer member rotates. A stand that can be taken in and out of the main body of the apparatus, and a lubricant supply means for supplying a lubricant onto the transfer member, and the cleaning blade scrapes off the lubricant supplied onto the transfer member by the lubricant supply means. In an image forming apparatus that prevents the cleaning blade from turning up, an attachment position detection unit that detects the attachment position of the gantry with respect to the apparatus main body, and a detection result of the attachment position detection unit. Te is a correction unit for correcting the position of supplying the lubricant by a lubricant supply means, that the image forming apparatus characterized by comprising a gist.

  Here, the image carrier is composed of, for example, a photosensitive drum or an intermediate transfer belt. A configuration in which an intermediate transfer belt is not provided and the image is directly transferred from a photosensitive drum to a sheet is also included. As the lubricant, a general lubricant may be used, and a lubricant added to the toner may be used, or the toner itself may be used as the lubricant.

  According to the present invention, it is possible to appropriately supply the lubricant to the cleaning blade and prevent the cleaning blade from turning up.

2 is a diagram illustrating a main part of the image forming apparatus 100. FIG. It is a figure which shows the case where the lubricant is appropriately supplied to the cleaning blade 96A. It is a figure which shows the case where the lubrication agent has shifted | deviated and supplied with respect to the cleaning blade 96A. It is a figure which shows a secondary transfer unit periphery. It is a perspective view of a secondary transfer unit. It is sectional drawing of a secondary transfer unit. It is a flowchart which shows an example of the process which supplies a position detection patch. It is a flowchart which shows an example of the process which supplies a supply patch. It is a figure which shows the example which supplies a position detection patch with a mass pattern. It is a figure which shows the example which supplies a position detection patch with a small amount pattern. It is a figure which shows the example which supplies a supply patch with a mass pattern. It is a figure which shows the example which supplies a supply patch with a small amount pattern. 6 is a flowchart illustrating an example of processing for supplying a supply patch when a paper position detection sensor is used.

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

  FIG. 1 is a diagram illustrating a main part of the image forming apparatus 100.

  The image forming apparatus 100 is called a tandem color image forming apparatus, and includes a plurality of sets of image forming units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 6, a paper feeding device 20, a fixing device 30, and the like. .

  A scanner 110 is installed on the upper part of the image forming apparatus 100. The document placed on the document table is scanned and exposed by the optical system of the document image scanning exposure apparatus of the scanner 110 and read by the line image sensor. The analog signal photoelectrically converted by the line image sensor is subjected to analog processing, A / D conversion, shading correction, image compression processing, and the like in the control means, and then input to the exposure units 3Y, 3M, 3C, and 3K.

  The image forming units 10Y, 10M, 10C, and 10K form yellow (Y), magenta (M), cyan (C), and black (K) images, respectively. The image forming unit 10Y includes a photoconductor drum 1 as an image carrier, a strip electrode 2, an exposure unit 3Y, a developing device 4, and a photoconductor cleaning unit 5. The same applies to the image forming units 10M, 10C, and 10K.

  The photosensitive drum 1 is configured, for example, by forming a photosensitive layer made of a resin containing an organic photoconductor on the outer peripheral surface of a drum-shaped metal base, and the width direction of the sheet S to be conveyed (FIG. 1). In FIG. 2, the direction is extended in the direction perpendicular to the paper surface. As the resin constituting the photosensitive layer, for example, polycarbonate can be used. In addition, although the structural example using the photoconductive drum 1 was demonstrated, it is not restricted to this, You may use a belt-shaped photoconductor.

  The band electrode 2 gives an electric charge to the photosensitive member of the photosensitive drum 1 and uniformly charges the surface of the photosensitive drum 1.

  The exposure units 3Y, 3M, 3C, and 3K perform photosensitivity by performing an exposure operation on the surface of the photosensitive drum 1 based on image data read from an original by the scanner 110 or image data transmitted from an external device. An electrostatic latent image is formed on the body drum 1.

  The developing device 4 contains a two-component developer composed of a toner having a small particle size (YMCK) corresponding to the image forming means and a carrier, and the electrostatic latent image formed on the photosensitive drum 1 is subjected to toner. To attach. As a result, a toner image is formed on the surface of the photosensitive drum 1.

  The photoconductor cleaning unit 5 removes toner remaining on the surface of the photoconductor drum 1 after the toner image carried on the photoconductor drum 1 is transferred to the intermediate transfer belt 6.

  The intermediate transfer belt 6 is rotatably supported by a plurality of rollers. The intermediate transfer belt 6 is an endless belt, and has a thickness of 0.04 to 0. 0 in which a conductive material is dispersed in engineering plastics such as modified polyimide, thermosetting polyimide, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride, and nylon alloy. 10 mm semi-conductive seamless belt.

  The respective color toner images formed on the photosensitive drum 1 by the image forming units 10Y, 10M, 10C, and 10K are sequentially transferred onto the rotating intermediate transfer belt 6 by the primary transfer rollers 7Y, 7M, 7C, and 7K ( (Primary transfer), a synthesized color image is formed. On the other hand, the residual toner is removed from the photosensitive drums 1Y, 1M, 1C, and 1K after the image transfer by the cleaning blades of the cleaning units 5 for the respective colors.

  The paper S stored in the paper storage unit 21 of the paper supply device 20 is supplied by the first paper supply unit 22 and is supplied with paper supply rollers 23, 24, 25A, 25B, a registration roller 26 (second paper supply unit). After that, the color image is transferred onto the sheet S (secondary transfer).

  The fixing device 30 sandwiches the paper S on which the color image is transferred on the secondary transfer belt 9 and fixes the color image on the paper S by applying heat and pressure. The sheet S is nipped and conveyed by the conveyance roller pair 37, is discharged from the sheet discharge roller 27 provided in the sheet discharge conveyance path, and is placed on a sheet discharge tray 90 outside the apparatus.

  On the other hand, after the color image is transferred to the paper S by the secondary transfer belt 9, the intermediate transfer belt 6 separates the curvature of the paper S, and the residual toner on the intermediate transfer belt 6 is removed by the cleaning blade 66 A of the cleaning unit 66. . Further, the toner (patch) or the like attached to the surface of the secondary transfer belt 9 is removed by the cleaning blade 96A of the cleaning unit 96.

  When copying on both sides of the sheet S, after fixing the image formed on the first side of the sheet S, the sheet S is branched from the discharge conveyance path by the branch plate 29 and introduced into the duplex conveyance path 28. The paper is reversed and conveyed again from the paper feed roller 25B. On the sheet S, images of the respective colors are formed on both sides by the image forming means 10Y, 10M, 10C, and 10K, heated and fixed by the fixing device 30, and discharged to the outside by the paper discharge roller 27.

  The control unit 50 includes a CPU and a memory, and executes various controls when the CPU executes a program stored in the memory.

  FIG. 2 is a view showing the periphery of the cleaning blade 96A. The secondary transfer belt 9 extends in the vertical direction in FIG. 2 in parallel with the paper surface, and the lubricant L is supplied onto the secondary transfer belt 9. The lubricant L is carried from the top to the bottom in FIG. 2 as the secondary transfer belt rotates, and is scraped off by the cleaning blade edge 96B.

  The cleaning blade edge 96B contacts the secondary transfer belt 9 in a direction (counter direction) opposite to the rotation of the secondary transfer belt 9, and scrapes off toner or the like on the secondary transfer belt 9.

  The cleaning blade end seal 96C is provided so that toner or the like does not leak outside the cleaning blade 96A (a position where the cleaning blade 96A cannot scrape foreign matter).

  The lubricant L is supplied to the secondary transfer belt 9 by the lubricant supply means and scraped off by the cleaning blade edge 96B. As a result, the lubricant is supplied to the cleaning blade edge 96B, the frictional resistance between the cleaning blade edge 96B and the secondary transfer belt 9 is reduced, and the cleaning blade 96A can be prevented from being turned over.

  In FIG. 2, the position of the lubricant L with respect to the cleaning blade edge 96B is a position where the lubricant is supplied to the entire end from one end to the other end. Can be supplied.

  FIG. 3 is a view showing the periphery of the cleaning blade 96A when the mounting position is deviated from the original position when the mount is attached to the apparatus main body. 4 to 6 are diagrams for explaining the secondary transfer unit. FIG. 4 is a view showing the periphery of the secondary transfer unit. FIG. 5 is a perspective view of the secondary transfer unit (a view in substantially the same direction as FIG. 4). FIG. 6 is a cross-sectional view of the secondary transfer unit (a view in the same direction as FIG. 1).

  In the image forming apparatus according to the present embodiment, the secondary transfer unit includes the secondary transfer belt 9 and the cleaning unit 96, and at least the secondary transfer unit is disposed on a pedestal that can be taken in and out of the apparatus main body.

  When the stand is pulled out at the time of jam occurrence or maintenance, and the stand is subsequently attached to the apparatus main body, the attachment position may be shifted from the original position. When the gantry is displaced with respect to the apparatus main body, the cleaning blade 96A disposed on the gantry is also displaced accordingly. For example, when the gantry is displaced in the direction of arrow D in FIG. 4, the cleaning blade 96A is also displaced in the direction of arrow D in FIG.

  On the other hand, since the lubricant supply means is attached to the apparatus main body, the lubricant is supplied onto the secondary transfer belt 9 regardless of the displacement of the gantry. Therefore, the lubricant L is not supplied to an appropriate position with respect to the cleaning blade 96A. Accordingly, the portion surrounded by the dotted line in FIG. 3 is not supplied with the lubricant, and the cleaning blade 96A is easily turned over.

  The image forming apparatus according to the present embodiment corrects the position of the lubricant L so that the lubricant L is supplied to an appropriate position even if the gantry is displaced (from the state of FIG. 3 to the state of FIG. 2). Correction).

  Specifically, the mounting position (relative position) of the gantry with respect to the apparatus main body is detected by the position detection sensor 97, and the supply position of the lubricant L by the lubricant supply means is corrected based on the detection result.

  As a method for detecting the attachment position, for example, a position detection sensor 97 is provided at the position shown in FIGS. 4 and 5 so as to be pulled out together with the gantry, and the lubricant L is placed on the secondary transfer belt 9 so that the attachment position can be detected. There is a method in which the position of the lubricant L is detected by the position detection sensor 97 and the mounting position of the gantry is detected by this detection (position of the lubricant L) (described in FIG. 7 and thereafter). ). This method utilizes the fact that the position of the lubricant L does not depend on the displacement of the gantry (the position of the lubricant L is determined by the position of the apparatus main body).

  As a sensor used as the position detection sensor 97, for example, a line sensor or an area sensor can be used. When the line sensor is used, it is necessary to provide the line sensor at least in a direction perpendicular to the sheet conveyance direction (drawing / attaching direction of the mount) in order to detect the attachment position.

  The attachment position detection method is not limited to the lubricant L, and the position of a member on the apparatus main body side (for example, the intermediate transfer belt 6) may be detected. A position detection sensor 97 is provided on the apparatus main body side to provide a member on the gantry side. May be detected. Any configuration that can detect the relative position of the gantry with respect to the apparatus main body may be used.

  The detection result by the position detection sensor 97 is transmitted to the control unit 50, and the control unit 50 corrects the supply position of the lubricant L by the lubricant supply unit based on the received detection result. For example, the reference position is determined in advance with respect to the position of the lubricant L, and the control unit 50 calculates the difference from the reference position based on the position of the lubricant L detected by the position detection sensor 97. Then, the correction amount of the supply position may be calculated based on the calculated difference, and the supply position of the lubricant supply unit may be shifted by the calculated correction amount.

  By adopting the above-described configuration, the supply position of the lubricant L is corrected even if a position shift occurs between the apparatus main body and the mount due to the insertion / removal of the mount, so that the lubricant is appropriately applied to the cleaning blade 96A. It is possible to prevent the cleaning blade 96A from being turned over. As a result, the foreign matter on the secondary transfer belt 9 can be reliably removed, so that a good image can be formed.

  When the position of the lubricant L supplied on the secondary transfer belt 9 by the lubricant supply means is detected by the position detection sensor 97 as a method for detecting the mounting position of the gantry with respect to the apparatus main body, the reference of the lubricant L is used. Since the deviation from the position can be directly grasped, the supply position of the lubricant L can be corrected more accurately.

  Further, the lubricant supply means needs to supply at least the lubricant L having a length longer than the length of the cleaning blade 96A in the longitudinal direction. When the lubricant L shorter than the cleaning blade 96A is used, the lubricant cannot be supplied to the end of the cleaning blade 96A. Further, the lubricant supply means supplies the lubricant L with the same length as the length of the cleaning blade 96A in the longitudinal direction, and supplies the lubricant L so that the lubricant is supplied from one end to the other end. It is preferable to correct the position. By adopting such a configuration, it is possible to suppress the consumption of the lubricant as compared with the case where the lubricant L longer than the cleaning blade 96A is used, and the lubricant leaks from the cleaning blade end seal 96C. This can be prevented.

  Next, the present embodiment will be described more specifically with reference to FIG.

  Hereinafter, a case where a toner image is used as the lubricant will be described, but other lubricants may be used. When a toner image is used as the lubricant, the lubricant supplying means can be constituted by the image forming means 10Y, 10M, 10C, and 10K (at least one of them), the photosensitive drum 1, and the intermediate transfer belt 6. The lubricant L (toner image) can be supplied onto the secondary transfer belt 9 without increasing the toner.

  In addition to supplying a toner image for the lubricant, a patch for density detection may be used as the lubricant. In this case, the toner consumption can be reduced compared to the case where the density detection patch is not used as a lubricant.

  In the following embodiments, a toner image (position detection patch) whose position is detected by the position detection sensor 97 and a toner image (supply patch) supplied with its supply position corrected based on the position of the position detection patch are used. The supply of two types of toner images (hereinafter, the position detection patch and the supply patch are collectively referred to as a cleaning patch) will be described. In the present embodiment, the position detection patch and the supply patch are not density detection patches but toner images to be supplied onto the secondary transfer belt 9 for position detection and lubricant supply, respectively.

  FIG. 7 is a flowchart illustrating an example of processing for supplying a position detection patch.

  In step S101, the control unit 50 determines whether it is detected that the power of the apparatus main body is turned on or the front door is opened and closed. The front door is a door that is provided in the apparatus main body and that opens and closes when the mount is taken in and out of the apparatus main body.

  When the power of the apparatus main body is turned off, there is a possibility that the gantry is put in and out for the purpose of maintenance. By detecting the mounting position of the gantry when the power source of the apparatus main body is turned on, the mounting position of the gantry can always be grasped, so that the lubricant can be reliably supplied to the cleaning blade 96A.

  Further, when the front door is opened and closed, there is a possibility that the gantry is put in and out for the purpose of jam processing or the like. By detecting the mounting position of the gantry when the front door is opened and closed, the mounting position of the gantry can always be grasped, so that the lubricant can be reliably supplied to the cleaning blade 96A.

  When the control unit 50 detects that the power of the apparatus main body is turned on or the front door is opened or closed (“YES” in step S101), the control unit 50 proceeds to step S102.

  In step S102, the control unit 50 determines whether or not the life of the cleaning blade 96A has exceeded a predetermined value. The life of the cleaning blade 96A indicates the usage status (usage period, etc.) of the cleaning blade 96A. Here, the life of the cleaning blade 96A is estimated from the number of prints after the cleaning blade 96A is started to be used (from the shipment of the image forming apparatus or the replacement of the cleaning blade 96A). That is, in step S102, it is determined whether or not the number of prints since the use of the cleaning blade 96A has reached a predetermined number. The number of prints used as the threshold can be set to 2000, for example.

  The life of the cleaning blade 96A may be any information as long as the usage status is known. For example, the determination may be made based on the number of rotations or elapsed time of a roller (for example, a roller on which the secondary transfer belt 9 is suspended) after the cleaning blade 96A is started to be used.

  When the life of the cleaning blade 96A has not passed the predetermined time ("NO" in step S102), the cleaning blade 96A has a short use period and the cleaning blade edge 96B is in a new state. The cleaning blade edge 96B is designed so that the foreign matter on the secondary transfer belt 9 is scraped without any leakage, so that the sliding resistance with the secondary transfer belt 9 is increased in a new state. Therefore, when the life of the cleaning blade 96A has not passed the predetermined time or more, the sliding resistance with the secondary transfer belt 9 is large, and it is easy to turn over. Accordingly, since it is necessary to supply a large number of cleaning patches in order to prevent turning-up, the control unit 50 supplies position detection patches in a large number of patterns (step S103).

  On the other hand, when the life of the cleaning blade 96A has exceeded a predetermined time ("YES" in step S102), the cleaning blade edge 96B is shortened in the paper transport direction due to wear compared to the new state. Therefore, the rubbing resistance between the cleaning blade edge 96B and the secondary transfer belt 9 is small, and it is difficult to turn over. Accordingly, since a small amount of cleaning patch is required to prevent turning, the control unit 50 supplies the position detection patch in a small amount pattern (step S104).

  Here, the amount of the cleaning patch is different between the large amount pattern and the small amount pattern. As a method of changing the amount of the cleaning patch, in addition to changing the shape (area), the density may be changed. However, the position detection patch needs to be detectable by the position detection sensor 97. Further, at least the large-scale pattern needs to supply the lubricant L having a length longer than the length of the cleaning blade 96A in the longitudinal direction.

  After supplying the position detection patch (after step S103 or step S104), the control unit 50 causes the position detection sensor 97 to detect the position of the position detection patch (step S105).

  In subsequent step S <b> 106, the control unit 50 calculates and stores the supply position correction amount of the supply patch based on the detection result of the position detection sensor 97.

  FIG. 8 is a flowchart illustrating an example of processing for supplying a supply patch.

  The process of supplying the supply patch starts with the conveyance of the sheet when performing an image forming job. The supply patch is supplied to the outside of the sheet in the front and rear direction of the sheet in the sheet conveyance direction (between sheets when a plurality of sheets are conveyed) or in the direction perpendicular to the sheet conveyance direction.

  In step S201, the control unit 50 determines whether or not the life of the cleaning blade 96A has exceeded a predetermined value.

  If the life of the cleaning blade 96A has not passed the predetermined time (“NO” in step S201), the control unit 50 supplies the supply patches in a large pattern (step S202).

  When the life of the cleaning blade 96A has exceeded a predetermined time ("YES" in step S201), the control unit 50 causes the supply patch to be supplied in a small amount pattern (step S203).

  In the supply patch supply (step S202 or step S203), the supply position correction amount stored in step S106 in FIG. 7 is called, and the supply patch is supplied after correcting the supply position.

  When the supply patch is supplied, the control unit 50 determines whether or not the job is finished (step S204).

  If the job has ended ("YES" in step S204), the process of supplying the supply patch ends.

  If the job has not ended ("NO" in step S204), the processing is repeated from step S201 (if the pattern is a small amount, it is supplied between papers (FIG. 12). 11)). Thus, the supply patch can be continuously supplied while the secondary transfer belt 9 is rotating (while the secondary transfer belt 9 and the cleaning belt 96A are rubbed).

  As a method of changing the amount of the cleaning patch with the supply patch, the supply frequency may be changed (when supplying between sheets, how many sheets are supplied may be changed).

  Further, in the process of supplying the supply patch (flowchart in FIG. 8), the position of the supply patch is not detected by using the position detection sensor 97, but the position of the gantry is not changed after the gantry is set on the apparatus main body. If the situation is deviated, the position of the supply patch may be detected as in the process of supplying the position detection patch (the flowchart of FIG. 7).

  9 to 12 are diagrams showing an example of a shape when supplying the cleaning patch. The arrow indicates the paper conveyance direction (the rotation direction of the secondary transfer belt 9). 9 to 12 are views of FIG. 5 viewed from above. The secondary transfer belt 9 extends parallel to the paper surface, and a lubricant L (cleaning patch) is supplied thereon. A position detection sensor 97 is provided above the secondary transfer belt 9.

  FIG. 9 is a diagram illustrating an example of a shape when supplying a large number of patterns (step S103 in FIG. 7) in supplying the position detection patch.

  When the life of the cleaning blade 96A has not exceeded a predetermined time, the cleaning blade 96A is likely to be turned over, so that the lubricant can be supplied to the entire cleaning blade edge 96B (from the state shown in FIG. 9 by the secondary transfer belt 9). When the lubricant is carried to the blade edge 96B, the position detection patch is supplied in the longitudinal direction of the cleaning blade 96A (as shown in FIG. 2). That is, it is preferable to supply the position detection patch with the same length as the length of the cleaning blade 96A in the longitudinal direction.

  In addition, the position detection patch supplied in a linear form in the paper conveyance direction in FIG. 9 is supplied to cause the position detection sensor 97 to detect the position of the position detection patch reliably and accurately. Here, the position detection patch is supplied in a linear shape, but may have a width in a direction perpendicular to the sheet conveyance direction. By reducing the width of the position detection patch in the direction perpendicular to the sheet conveyance direction, toner consumption can be suppressed.

  Further, depending on the position detection method of the position detection sensor 97, there may be no position detection patch supplied linearly in the paper conveyance direction in FIG. That is, even when there is no position detection patch supplied linearly in the paper conveyance direction, the position detection sensor 97 can detect the position of the position detection patch only with the position detection patch supplied in the longitudinal direction of the cleaning blade 96A. The position detection patch that is linearly supplied in the paper conveyance direction can be eliminated. Further, the length in the paper conveyance direction of the position detection patch supplied linearly in the paper conveyance direction may be appropriately changed within a range in which the position detection sensor 97 can detect the position of the position detection patch.

  Further, in FIG. 9, the position detection patch supplied linearly in the paper conveyance direction is supplied to a position corresponding to the longitudinal end portion of the cleaning blade 96A, but corresponds to the vicinity of the longitudinal center of the cleaning blade 96A. You may supply to the position to do. The position in the longitudinal direction of the cleaning blade 96A of the position detection patch supplied linearly in the sheet conveyance direction can be appropriately changed according to the position where the position detection sensor 97 is provided.

  Further, the position detection patch supplied linearly in the paper conveyance direction starts from the position detection patch supplied in the longitudinal direction of the cleaning blade 96A, and is upstream in the paper conveyance direction (in the rotation of the secondary transfer belt 9). Although it extends linearly toward the upstream side, it may extend linearly toward the downstream side (downstream side in the rotation of the secondary transfer belt 9) in the paper transport direction. Moreover, you may extend to both the upstream and downstream sides.

  Note that the position detection patch supplied linearly in the paper conveyance direction is not limited to a linear shape, and may be various shapes as long as the position detection sensor 97 can detect the position. By making it linear, the position detection sensor 97 can detect the position of the position detection patch more reliably and accurately.

  FIG. 10 is a diagram illustrating an example of a shape in the case of supplying the position detection patch in a small amount pattern (step S104 in FIG. 7). FIG. 10 corresponds to the case where there is no position detection patch supplied in the longitudinal direction of the cleaning blade 96A of FIG.

  When the life of the cleaning blade 96A has exceeded a predetermined period, the cleaning blade 96A is unlikely to be turned over, so that a position detection patch for the longitudinal direction of the cleaning blade 96A is not necessary. For this reason, the position detection patch is supplied linearly in the sheet conveyance direction for the purpose of suppressing toner consumption. However, as in the case of supplying a large number of patterns in the supply of position detection patches (FIG. 9), the position detection sensor 97 determines the shape and position of the position detection patches supplied linearly in the paper transport direction. The position can be appropriately changed within a range where the position can be detected.

  Further, in the supply of position detection patches, when the large amount pattern (FIG. 9) is compared with the small amount pattern (FIG. 10), the amount of the position detection patch may be smaller in the small amount pattern than in the large amount pattern. Therefore, in addition to eliminating the position detection patch supplied in the longitudinal direction of the cleaning blade 96A, the area of the position detection patch supplied in the longitudinal direction of the cleaning blade 96A may be reduced or supplied in the longitudinal direction of the cleaning blade 96A. The density of the position detection patch to be applied may be lowered.

  FIG. 11 is a diagram illustrating an example of a shape in the case of supplying a supply pattern in a large amount pattern (step S202 in FIG. 8).

  The supply patch is supplied when the sheet is conveyed to the secondary transfer belt 9. When the supply patch is supplied in a large pattern, the supply patch is supplied so as to surround the sheet conveyed on the secondary transfer belt 9. By supplying the supply patch to the outside of the sheet in the direction perpendicular to the sheet conveyance direction, more lubricant can be supplied to the end of the cleaning blade edge 96B. As in the supply patch shown in FIG. 11, the four sides of the paper do not necessarily have to be completely surrounded by the supply patch (the four sides of the paper may not be surrounded by the supply patch).

  However, it is preferable to supply the supply patch to the outside of the sheet when the sheet is included on a straight line perpendicular to the sheet conveyance direction (not between sheets). When the life of the cleaning blade 96A does not elapse for a predetermined time or more, the cleaning blade 96A is likely to be turned over. Thus, as compared with the case where the supply patch is supplied only between the sheets, the cleaning blade 96A can be turned over. More lubricant can be supplied to the position corresponding to the end, and the cleaning blade 96A can be prevented from turning up.

  In FIG. 11, the supply patch is supplied for each sheet (the supply patch is divided between sheets), but the supply patch may be continuously supplied in the sheet conveyance direction without being divided.

  FIG. 12 is a diagram illustrating an example of a shape in the case where the supply patch is supplied in a small amount pattern (step S203 in FIG. 8).

  When the life of the cleaning blade 96A has passed a predetermined time or more, the cleaning blade 96A is not easily turned over, so that the supply patch is supplied only between the sheets for the purpose of suppressing toner consumption.

  However, in the supply of the supply patch, when the large amount pattern (FIG. 11) is compared with the small amount pattern (FIG. 12), the amount of the supply patch may be smaller than the large amount pattern. Therefore, as shown in FIG. 12, in addition to eliminating the supply patch outside the sheet in the direction perpendicular to the sheet conveyance direction, the area of the supply patch may be reduced (the outside of the sheet in the direction perpendicular to the sheet conveyance direction). The supply patch density may be lowered).

  When supplying the cleaning patches in a large pattern (FIGS. 9 and 11), it is preferable to supply the cleaning patches at as high a density as possible in order to supply as many cleaning patches as possible. If the maximum density value (maximum density) is determined for the image forming apparatus, the maximum density is preferable. It should be noted that any number of colors can be used. The maximum density for only one color may be used, or the maximum density for a plurality of colors (two colors, three colors, four colors) may be used.

  FIG. 13 shows a case where the processing for supplying the supply patch (see FIG. 8) is further performed by detecting the paper position by the paper position detection sensor and correcting the supply position of the supply patch based on the detected paper position. It is an example of a flowchart. The sheet position detection sensor may be provided anywhere as long as the sheet position can be detected. For example, the sheet position detection sensor is provided at a position away from the secondary transfer belt 9 such as the vicinity of the position detection sensor 97.

  Steps S301 to S304 are the same as steps S201 to S204 in FIG.

  After supplying the supply patches in a large pattern (after step S302), in step S305, the control unit 50 causes the paper position detection sensor to detect edges on both sides of the paper (edges parallel to the paper conveyance direction).

  In step S <b> 306, the control unit 50 calculates and stores a correction amount of the supply position when supplying the supply patch in a large pattern based on the edge of the paper detected using the paper position detection sensor. In this correction, the supply position is corrected from the outside of the sheet toward the edge of the sheet in a direction perpendicular to the sheet conveyance direction. By this correction, the width to which the cleaning patch is supplied widens in the direction perpendicular to the sheet conveyance direction, and a larger amount of cleaning patch can be supplied.

  After the supply patch is supplied, if the job is not completed in the determination in step S304 and the next supply patch is supplied in a large pattern (when the process proceeds to step S302), the correction calculated and stored in step S306 is stored. A supply patch (mass pattern) is supplied after correcting the supply position based on the amount.

  The correction of the supply position is preferably performed by repeatedly increasing the width until reaching a predetermined distance from the edge of the sheet, and gradually moving closer to the edge of the sheet. By doing so, it is possible to prevent the supply patch from being erroneously supplied onto the paper.

  Here, the predetermined distance may be determined as an absolute value based on the performance and specifications of the image forming units 10Y, 10M, 10C, and 10K, the image carrier, or the edge of the paper detected using the paper position detection sensor. May be determined relatively based on the difference (distance) between the patch and the supply patch detected using the position detection sensor 97 (may be determined as a ratio to the difference).

  The paper position detection sensor may be configured to detect the edge of the paper, and may be the same member as the position detection sensor 97. When the position detection sensor 97 is also used for detecting the sheet position, it is possible to save space and reduce the number of parts (cost reduction).

  As described above with reference to FIGS. 7 to 13, the cleaning patch is supplied by correcting the supply position based on the position detection patch (position detection sensor 97 detects the position) and the supply patch (position detection patch 97). ), The lubricant can be supplied to the cleaning blade 96A in an appropriate and efficient manner.

  Further, by making the shape of the position detection patch different from the shape of the supply patch, the shape of the patch can be changed according to the use of each cleaning patch, so that the lubricant is efficiently supplied to the cleaning blade 96A. can do.

  Also, by making the amount of supplied patch larger than the amount of position detection patch, a sufficient amount of lubricant can be supplied at the time of image formation, and consumption of the lubricant can be kept to the minimum necessary for position detection. it can.

  Here, the method of increasing the amount of the supply patch more than the amount of the position detection patch may increase the density of the cleaning patch in addition to increasing the area of the shape. Therefore, the area of the shape of the position detection patch may not be larger than the area of the shape of the supply patch. Even if the area is the same, it is sufficient that the concentration is high.

  In addition, the position detection patch is configured to be supplied when the power supply of the apparatus main body is detected or when the installation / removal of the installation base is detected, so that the installation position of the installation base can be always grasped. The lubricant can be reliably supplied to 96A.

  Further, the supply patch is configured to be supplied when the sheet is conveyed to the secondary transfer belt 9, so that the secondary transfer belt 9 is rotating (the secondary transfer belt 9 and the cleaning belt). The supply patch can be supplied while 96A is rubbing.

  Further, since the amount of the cleaning patch supplied onto the secondary transfer belt 9 is changed according to the life of the cleaning blade 96A, only the necessary amount of the cleaning patch can be supplied, and the consumption of toner can be suppressed. it can. The method for changing the amount of the cleaning patch can change the area and density in the same manner as the method for increasing the amount of the supply patch more than the amount of the position detection patch.

  In this embodiment, the amount of the cleaning patch is changed into two patterns, a small amount pattern and a large amount pattern. However, the amount of the cleaning patch is divided into three or more patterns according to the life of the cleaning blade 96A. May be changed. Further, the amount of the cleaning patch may be gradually reduced according to the life of the cleaning blade 96A.

  Further, when a paper position detection sensor for detecting the position of the paper conveyed on the secondary transfer belt 9 is provided, the shape of the supply patch can be corrected based on the detection result of the paper position detection sensor. The lubricant can be supplied to the cleaning blade 96A more appropriately than in the case where the paper position detection sensor is not used.

  Further, the supply patch is supplied to a position as close as possible to the edge of the paper in the area outside the paper by widening the width of the supply patch supplied from the outside of the paper toward the edge of the paper detected by the paper position detection sensor. The width of the lubricant supplied to the cleaning patch 96A can be increased.

  In the present embodiment, the paper position detection sensor is configured to detect the edges on both sides of the paper, but may be configured to detect (at least one of) the leading edge and the trailing edge of the paper. In the configuration for detecting the leading edge of the paper and the trailing edge of the paper, the supply position is corrected based on the detected positional information of the leading edge of the paper and the trailing edge of the paper so that the width of the supply patch supplied between the papers is widened in the paper conveyance direction. Can do. In this way, the width of the supply patch may be widened, or the supply patch may be moved in the paper conveyance direction based on the detected positional information on the leading edge and the trailing edge of the paper. Thereby, when supplying a supply patch between paper, a possibility that a supply patch may adhere to paper can be reduced. Further, all four edges may be detected together with the edges on both sides of the sheet. An arbitrary edge may be selected and detected from the four edges.

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 3 Exposure part 4 Developing device 6 Intermediate transfer belt 9 Secondary transfer belt 10 Image forming means 20 Paper feeding device 30 Fixing device 50 Control part 66, 96 Cleaning part 66A, 96A Cleaning blade 97 Position detection sensor

Claims (14)

An image forming unit for forming a toner image;
An image carrier for carrying a toner image formed by the image forming unit;
An apparatus main body to which the image forming unit and the image carrier are fixed;
The apparatus attached to the apparatus main body, comprising: a transfer member that transfers the toner image onto a sheet; and a cleaning blade that contacts the transfer member and removes foreign matter on the transfer member as the transfer member rotates. A stand that can be taken in and out of the main body,
Lubricant supply means for supplying a lubricant onto the transfer member;
With
In the image forming apparatus that prevents the cleaning blade from turning up by scraping the lubricant supplied onto the transfer member by the lubricant supply means,
An attachment position detector for detecting an attachment position of the gantry with respect to the apparatus main body;
A correction unit that corrects the supply position of the lubricant by the lubricant supply unit based on the detection result of the attachment position detection unit;
An image forming apparatus comprising: The mounting position detector is
Provided on the mount,
The image forming apparatus according to claim 1, wherein the mounting position of the gantry with respect to the apparatus main body is detected by detecting a position of the lubricant supplied onto the transfer member by the lubricant supply unit. . The lubricant supply means includes
A first shape for detecting the position by the mounting position detection unit, and a second supply for which the supply position is corrected by the correction unit based on the position of the first shape detected by the position detection unit. The image forming apparatus according to claim 2, wherein the lubricant is supplied onto the transfer member by dividing the shape into shapes. The image forming apparatus according to claim 3, wherein the first shape and the second shape are different shapes. The image forming apparatus according to claim 3, wherein the second shape is configured by a larger amount of lubricant than the first shape. The first shape is:
6. The image forming apparatus according to claim 3, wherein the image forming apparatus is supplied onto the transfer member when a power-on of the apparatus main body is detected or a loading / unloading of the mount is detected. The second shape is:
The image forming apparatus according to claim 3, wherein the sheet is supplied onto the transfer member when the sheet is conveyed to the transfer member. The lubricant supply means includes
The image forming apparatus according to claim 1, wherein the image forming apparatus includes the image forming unit and the image carrier, and the toner image is used as a lubricant. The image forming unit includes:
Forming a patch for density detection on a region on the image carrier to be transferred to the outside of the sheet on the transfer member;
The toner image used as the lubricant is
The image forming apparatus according to claim 8, wherein the image forming apparatus is a patch transferred onto the transfer member outside the sheet. The lubricant supply means includes
Supplying the lubricant with the same length as the cleaning blade in the longitudinal direction of the cleaning blade,
The correction unit is
The lubricant supply position by the lubricant supply means is corrected so that the lubricant is supplied from one end to the other end in the longitudinal direction of the cleaning blade. The image forming apparatus according to claim 1. A paper position detector that detects the position of the paper conveyed on the transfer member;
The correction unit is
The image forming apparatus according to claim 1, wherein the shape of the lubricant supplied by the lubricant supply unit is corrected based on a detection result of the paper position detection unit. The lubricant supply means includes
Supply lubricant to the outside of the paper at least in the direction perpendicular to the paper transport direction,
The correction unit is
12. The image forming apparatus according to claim 11, wherein the width of the lubricant supplied from the outside of the sheet in a direction perpendicular to the sheet conveyance direction is increased toward the edge of the sheet detected by the sheet position detection unit. apparatus. The image forming apparatus according to claim 9, wherein the attachment position detection unit and the sheet position detection unit are the same member. The correction unit is
14. The information on the usage status of the cleaning blade is acquired, and the amount of the lubricant supplied onto the transfer member is changed according to the information on the usage status of the cleaning blade. The image forming apparatus according to claim 1.

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