JP2014174198A - Image forming apparatus and controller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus or the like which is capable of calculating the amount of toner accumulated on removal accumulation means for removing and accumulating the toner adhered to transfer means from the toner image of a transfer body.SOLUTION: An image forming apparatus 1 includes a primary transfer part 10 sequentially transferring a plurality of kinds of toner images formed by respective image forming units 2Y, 2M, 2C, and 2K to an intermediate transfer belt 15 and a secondary transfer part 20 collectively transferring toner images for image formation transferred on the intermediate transfer belt 15 to a paper P. A roll cleaner 40 removing and accumulating the toner adhered to a secondary transfer roll 22 is provided below the secondary transfer roll 22 of the secondary transfer part 20. An image formation control part 80 calculates the amount of the toner removed from the secondary transfer roll 22 and accumulated on the roll cleaner 40, from the operation state of the secondary transfer part 20 and the shift rate of the toner shifted to the secondary transfer roll 22.

Description

  The present invention relates to an image forming apparatus and a control apparatus.

  As a prior art described in the publication, an image including an intermediate transfer medium on which a toner image formed on a photoreceptor is primarily transferred, and a secondary transfer unit that secondarily transfers the toner image on the intermediate transfer medium onto transfer paper. In the forming apparatus, a cleaning unit that removes toner remaining on the intermediate transfer medium after the secondary transfer, a waste toner container that stores waste toner removed from the intermediate transfer medium by the cleaning unit, and the toner image Dot counting means for counting the number of pixels to be formed; and accommodation amount determining means for integrating the number of pixels counted by the dot counting means and determining the amount of waste toner contained in the waste toner container based on the accumulated value. There is an image forming apparatus provided (see Patent Document 1).

  Further, as a prior art described in other publications, in an image forming apparatus that transfers a toner image formed on an image carrier onto transfer paper, a waste toner container that contains waste toner removed from the image carrier, A waste amount container for detecting whether or not a waste toner amount in a waste toner container is equal to or greater than a predetermined amount set to be less than full; a dot counting unit for counting the number of pixels forming the toner image; Integration of the number of pixels counted by the dot counting unit is started when the amount of waste toner detected by the storage amount detection unit is greater than or equal to the predetermined amount, and the integrated value is set to a predetermined value. There is an image forming apparatus provided with a full determination means for determining that the waste toner storage capacity has reached full when the value reaches (see Patent Document 2).

  Further, as conventional techniques described in other publications, an image carrier, a toner image forming unit that forms a toner image corresponding to a document image on the image carrier, and a toner supply that replenishes the toner image forming unit Means, toner patch forming means for forming a toner patch on the image carrier, and calculation means for calculating a used toner amount based on an accumulated time required for toner replenishment and an accumulated number of times the toner patch is formed. There exists an image forming apparatus provided with (see Patent Document 3).

  Furthermore, as a conventional technique described in other publications, an image carrier that carries a toner image developed with toner, a transfer unit that transfers the toner image to another medium, and waste that remains on the image carrier. Cleaning means for collecting toner, storage means for storing the recovered waste toner, full proximity position detection means for detecting that the waste toner has been stored to a full proximity position of the storage means, and the image In an image forming apparatus having an image information detecting means for detecting information relating to an image on a carrier and an image forming state recognizing means for recognizing an image forming state, the waste toner is accommodated up to a full proximity position in the accommodating means. Is detected by the full proximity position detection means, based on the detection result by the image information detection means and the recognition result by the image formation state recognition means. Te integrates the image quantity, the multiplication result is an image forming apparatus is present waste toner is provided full determination means determines that full reached when it reaches a predetermined value (see Patent Document 4).

  As another conventional technique described in other publications, an image forming apparatus that transfers a toner image formed on an image carrier to a transfer material, and removes waste toner remaining on the image carrier after the transfer and collects it in a collection unit. However, there is an image forming apparatus that calculates the accumulated amount of the collected waste toner from the consumed toner amount and the transfer efficiency (see Patent Document 5).

JP 2003-270963 A JP 2003-271023 A Japanese Patent Laid-Open No. 9-258620 JP 2005-284012 A JP 2003-316224 A

  An object of the present invention is to provide an image forming apparatus that can calculate the amount of toner accumulated in a removing and accumulating unit that removes and accumulates toner adhering to a transferring unit from a toner image on a transfer body.

The invention according to claim 1 has a plurality of operating states, a toner image forming body on which a toner image is formed, a transfer body onto which the toner image formed on the toner image forming body is transferred, Transfer means for transferring the toner image transferred to the transfer body to a transfer body in a predetermined operation state in a plurality of operation states, and shifting from the toner image transferred to the transfer body to the transfer means A removal accumulation means for removing and accumulating the toner, and a transfer rate at which the toner is transferred from the toner image transferred to the transfer body to the transfer means in correspondence with each of the plurality of operation states of the transfer means Acquired by the transfer rate acquisition means, the image information acquisition means for acquiring image information defining the toner image, and the image information acquired by the image information acquisition means and the transfer rate acquisition means From said transition rate, an image forming apparatus and a toner amount calculating means for calculating an amount of toner accumulated in the removed storage means.
According to a second aspect of the present invention, the transfer rate acquired by the transfer rate acquiring unit is set based on an electric field applied to the toner image in each of the plurality of operating states of the transfer unit. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.
3. The image forming apparatus according to claim 1, further comprising contact / separation means for setting the transfer body and the transfer means in a contacted state or a separated state. It is.
The invention according to claim 4 is characterized in that the plurality of operation states of the transfer means include a state in which the transfer body set by the contact / separation means and the transfer means are separated from each other. The image forming apparatus described.
The invention according to claim 5 includes a first threshold value, and a second threshold value that is larger than the first threshold value and smaller than a capacity at which the removal accumulation means can accumulate toner, When the toner amount accumulated in the removal accumulation unit calculated by the toner amount calculation unit is equal to or larger than the first threshold value, the first notification is performed, and when the toner amount is equal to or larger than the second threshold value. The image forming apparatus according to claim 1, further comprising a notifying unit that performs second notification.
The invention according to claim 6 further includes environmental information acquisition means for acquiring environmental information surrounding the transfer means, and corrects the transition rate based on the environmental information acquired by the environmental information acquisition means. The image forming apparatus according to claim 1, further comprising a unit.
The invention according to claim 7 has a plurality of operating states, a toner image forming body on which a toner image is formed, a transfer body on which the toner image formed on the toner image forming body is transferred, In a predetermined operation state in a plurality of operation states, a transfer unit that transfers the toner image transferred to the transfer body to the transfer target, and a transfer from the toner image transferred to the transfer body to the transfer unit And a removal accumulating unit that removes and accumulates the toner that has been removed, and is connected to the image forming apparatus, and corresponds to each of the plurality of operating states of the transfer unit Transfer rate acquisition means for acquiring a transfer rate at which toner transfers from the toner image transferred to the transfer body to the transfer means, and image information acquisition for acquiring image information defining the toner image And a toner amount calculation unit that calculates the toner amount accumulated in the removal accumulation unit from the image information acquired by the image information acquisition unit and the transfer rate acquired by the transfer rate acquisition unit. Is a control device characterized by
The invention according to claim 8 is the control device according to claim 7, further comprising contact / separation means for setting the transfer body and the transfer means in contact with or separated from each other.
The invention according to claim 9 is characterized in that the plurality of operation states of the transfer means include a state in which the transfer body set by the contact / separation means and the transfer means are separated from each other. It is a control apparatus of description.

According to the first aspect of the present invention, compared to the case where this configuration is not used, it is possible to calculate the amount of toner accumulated in the removing and accumulating unit that removes and accumulates toner adhering to the transfer unit from the toner image on the holder.
According to the second aspect of the present invention, the accuracy of calculating the accumulated toner amount is improved as compared with the case where the toner amount is not set based on the electric field.
According to the third aspect of the present invention, it is possible to suppress the amount of accumulated toner as compared with the case where this configuration is not used.
According to the invention of claim 4, the accuracy of calculating the accumulated toner amount is further improved as compared with the case where this configuration is not used.
According to the fifth aspect of the present invention, the removal accumulating means can be managed more easily than when this configuration is not used.
According to the sixth aspect of the present invention, the accuracy of calculating the accumulated toner amount is further improved as compared with the case where the correction based on the environmental information is not performed.
According to the seventh aspect of the present invention, compared to the case where this configuration is not used, it is possible to calculate the amount of toner accumulated in the removal accumulating unit that removes and accumulates toner adhering to the transfer unit from the toner image on the holding body.
According to the eighth aspect of the present invention, the amount of accumulated toner can be suppressed as compared with the case where this configuration is not used.
According to the invention of claim 9, the accuracy of calculating the amount of accumulated toner is further improved as compared with the case where this configuration is not used.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus to which the exemplary embodiment is applied. FIG. 4 is a diagram illustrating an example of a toner image on an intermediate transfer belt. It is a figure which shows an example of the area | region of MEM of an image formation control part. 6 is an example of a flowchart for managing the roll cleaner by estimating the amount of waste toner accumulated in the accumulation unit of the cleaner housing.

[Image forming apparatus 1]
FIG. 1 is a schematic configuration diagram illustrating an example of an image forming apparatus 1 to which the exemplary embodiment is applied. An image forming apparatus 1 shown in FIG. 1 is an intermediate transfer type image forming apparatus generally called a tandem type, and includes a plurality of image forming units 2Y, 2M, 2C, 2K, toner images of respective colors (components) formed by the image forming units 2Y, 2M, 2C, and 2K are transferred onto the intermediate transfer belt 15 and the primary transfer unit 10 that sequentially transfers (primary transfer) to the intermediate transfer belt 15. Secondary transfer unit 20 that collectively transfers (secondary transfer) toner images (toner images on which toner images of respective colors are superimposed) to paper P, which is an example of a transfer target, and paper P that has been secondarily transferred A fixing unit 60 is provided for fixing on the top. In addition, the image forming control unit 80 that controls the operation of each device (each unit), and a UI (user interface) unit 90 that receives an image forming operation command by the user and notifies the user of the state of the image forming device 1 are provided. Yes. Note that the image formation control unit 80 includes a CPU 81 that executes a calculation and a MEM 82 that stores variables, constants, and the like used by the CPU 81 for the calculation.
The image formation control unit 80 (CPU 81) is an example of a transition rate acquisition unit, an image information acquisition unit, a toner amount calculation unit, a notification unit, and a transition rate correction unit.

  In the present embodiment, each of the image forming units 2Y, 2M, 2C, and 2K includes a charger 12 that charges the photosensitive drum 11 around the photosensitive drum 11 that rotates in the direction of arrow A, and a toner image forming body. As an example, a laser exposure device 13 for writing an electrostatic latent image on the photosensitive drum 11 (exposure beam is indicated by Bm in the figure), each color toner is accommodated and the electrostatic latent image on the photosensitive drum 11 is stored. A developing unit 14 that visualizes the image with toner, a primary transfer roll 16 that transfers the toner images of each color formed on the photosensitive drum 11 to an intermediate transfer belt 15 as an example of a transfer body at the primary transfer unit 10; Electrophotographic devices such as a drum cleaner 17 for removing residual toner on the photosensitive drum 11 are sequentially arranged. These image forming units 2Y, 2M, 2C, and 2K are arranged in the order of yellow (Y), magenta (M), cyan (C), and black (K) from the upstream side of the intermediate transfer belt 15.

The intermediate transfer belt 15 is constituted by a film-like endless belt in which a suitable amount of a conductive agent such as carbon black is contained in a resin such as polyimide or polyamide. And the volume resistivity is formed so that it may become 10 < ⁶ > -10 < ¹⁴ > (omega | ohm) cm, The thickness is comprised by about 0.1 mm, for example. The intermediate transfer belt 15 is circulated and driven (rotated) at a predetermined speed in the direction of arrow B shown in FIG. 1 by various rolls. The various rolls include a drive roll 31 that is driven by a motor (not shown) having excellent constant speed and rotates the intermediate transfer belt 15, and an intermediate transfer belt that extends linearly along the arrangement direction of the photosensitive drums 11. 15, a support roll 32 that supports the intermediate transfer belt 15, a tension roll 33 that functions as a correction roll that applies tension to the intermediate transfer belt 15 and prevents the intermediate transfer belt 15 from meandering, a backup roll 25 provided in the secondary transfer unit 20, an intermediate A cleaning backup roll 34 provided opposite to the intermediate transfer belt cleaner 35 that scrapes residual toner on the transfer belt 15 is provided.

The primary transfer unit 10 includes a primary transfer roll 16 that is disposed to face the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween. The primary transfer roll 16 includes a shaft and a sponge layer as an elastic body layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ⁷ to 10 ⁹ Ωcm. The primary transfer roll 16 is disposed in pressure contact with the photosensitive drum 11 with the intermediate transfer belt 15 interposed therebetween.
Further, a positive voltage (primary transfer bias) having a polarity opposite to the charging polarity of the toner (here, described as negative polarity as an example) is applied to the primary transfer roll 16. As a result, the toner images on the respective photosensitive drums 11 are sequentially electrostatically attracted to the intermediate transfer belt 15, and the toner images are primarily transferred onto the intermediate transfer belt 15.

The secondary transfer unit 20 includes a secondary transfer roll 22 as an example of a transfer unit that is disposed to face the backup roll 25 with the intermediate transfer belt 15 interposed therebetween. The secondary transfer roll 22 is disposed on the toner image holding surface side of the intermediate transfer belt 15 and is grounded (ground voltage GND). A metal power feeding roll 26 is disposed in contact with the backup roll 25.
The secondary transfer roll 22 is disposed in pressure contact with the backup roll 25 with the intermediate transfer belt 15 interposed therebetween.

The power supply roll 26 is connected to a secondary transfer power supply 27. When the secondary transfer power supply 27 supplies a voltage to the power supply roll 26, the voltage is applied to the secondary transfer roll 22. Thereby, an electric field is formed in the secondary transfer part 20 (between the secondary transfer roll 22 and the backup roll 25).
Here, when the secondary transfer power supply 27 supplies a negative voltage to the power supply roll 26, a secondary transfer electric field (secondary transfer bias) is formed in the secondary transfer unit 20. When the paper P is conveyed to the secondary transfer unit 20 in this state, toner images (image forming toner images 101a and 101b in FIG. 2 described later) are electrostatically attracted and secondarily transferred to the paper P.
The secondary transfer bias is an electric field formed between the secondary transfer roll 22 and the backup roll 25 with the intermediate transfer belt 15 in between, and is expressed as the secondary transfer power supply 27 supplies the secondary transfer bias. .

As will be described later, the secondary transfer power supply 27 supplies a positive voltage having a polarity opposite to that of the secondary transfer bias, instead of the secondary transfer bias, depending on the timing. With this positive voltage, a non-transfer electric field (non-transfer bias) is formed in the secondary transfer portion 20. Again, the secondary transfer power supply 27 is described as supplying a non-transfer bias.
The non-transfer bias will be described later.

The backup roll 25 is composed of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and EPDM rubber on the inside. And it is formed so that the surface resistivity may be 10 ⁷ to 10 ¹⁰ Ω / □, and the hardness is set to 70 ° (Asker C), for example.

On the other hand, the secondary transfer roll 22 includes a shaft and a sponge layer as an elastic body layer fixed around the shaft. The shaft is a cylindrical bar made of metal such as iron or SUS. The sponge layer is a sponge-like cylindrical roll formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black and having a volume resistivity of 10 ⁷ to 10 ⁹ Ωcm.

  In the vicinity of the secondary transfer unit 20, an environment measurement unit 28 is provided as an example of an environment information acquisition unit that measures environment information related to environmental conditions such as temperature and / or humidity.

  A roll cleaner 40 as an example of a removing and accumulating unit that removes and accumulates toner attached (transferred) to the secondary transfer roll 22 is provided below the secondary transfer roll 22. The roll cleaner 40 is disposed downstream of the secondary transfer unit 20 in contact with the secondary transfer roll 22 so as to be rotatable, and further downstream of the secondary transfer roll 22 in the rotation direction of the secondary transfer roll 22 than the cleaning brush 41. A cleaning blade 42 is provided. The roll cleaner 40 is disposed so as to be in contact with the cleaning brush 41 and holds a lubricant block 43 that holds the lubricant supplied to the cleaning brush 41, a cleaning brush 41, a cleaning blade 42, and a cleaner block that houses the lubricant block 43. A housing 44 and a support member 45 for fixing and supporting the cleaning blade 42 to the cleaner housing 44 are provided. Further, the cleaner housing 44 is provided with a storage unit 46 for storing waste toner.

The cleaning brush 41 has a hair bundle spirally planted on the surface of a shaft made of metal or the like. The hair is made of insulating polypropylene that is easily charged to the same polarity (negative polarity) as the toner.
The cleaning brush 41 is rotationally driven at a predetermined speed by a drive motor (not shown).

  A lubricant block 43 is arranged so as to contact the cleaning brush 41. The lubricant held by the lubricant block 43 is supplied to the cleaning brush 41 and is supplied onto the secondary transfer roll 22 as the cleaning brush 41 rotates. The lubricant is, for example, zinc stearate.

  The lubricant reduces the friction between the secondary transfer roll 22 and the cleaning blade 42 and prevents the cleaning blade 42 from curling.

The cleaning blade 42 is formed in a long plate shape with a resin such as urethane rubber, and an end portion (one ridge) in the short side direction is in a counter direction with respect to the rotation direction (arrow C direction) of the secondary transfer roll 22. It is provided to touch. Therefore, as the secondary transfer roll 22 rotates, the cleaning blade 42 scrapes off the toner adhering (transferred) onto the secondary transfer roll 22.
The support member 45 fixes the cleaning blade 42 to the cleaner housing 44 so that the cleaning blade 42 contacts the secondary transfer roll 22 at a predetermined pressure.

  The wobbling of the cleaning blade 42 means that the end in the short direction of the cleaning blade 42 that is in contact with the counter transfer direction of the secondary transfer roll 22 loses the rotational force of the secondary transfer roll 22. This means that the secondary transfer roll 22 moves downstream in the rotational direction. The cleaning blade 42 may be bent at a part of the cleaning blade 42, particularly at both ends, in addition to the case of the cleaning blade 42 as a whole.

The toner scraped off by the cleaning blade 42 falls to the accumulation portion 46 in the cleaner housing 44 and is accumulated as waste toner.
The cleaner housing 44 may include a member that smoothes out the waste toner in the accumulating portion 46 so as not to be displaced.

  In the roll cleaner 40 according to the present embodiment, the waste toner accumulated in the accumulating portion 46 of the cleaner housing 44 is not collected but stored. Then, before the waste toner accumulated in the accumulation unit 46 overflows from the accumulation unit 46, the secondary transfer roll 22 and the roll cleaner 40 are replaced together.

  In addition, a mechanism (contacting / separating means) is provided for setting the state in which the secondary transfer roll 22 and the intermediate transfer belt 15 are in contact with each other and the state in which they are separated (retracted) (so as to be able to contact and separate). Then, in a case where the paper P is jammed without being conveyed in the secondary transfer unit 20 (jam), the secondary transfer roll 22 is separated from the intermediate transfer belt 15 integrally with the roll cleaner 40 ( Is configured to retract). This state is referred to as a state in which the secondary transfer roll 22 is retracted (“retract mode”).

  Further, on the downstream side of the secondary transfer portion 20 of the intermediate transfer belt 15, an intermediate transfer belt that removes residual toner and paper dust on the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15. A cleaner 35 is provided so as to be able to contact and separate. On the other hand, on the upstream side of the yellow image forming unit 2Y, there is a reference sensor (home position sensor) 71 that generates a reference signal as a reference for taking image forming timings in each of the image forming units 2Y, 2M, 2C, and 2K. It is arranged. Further, an image density sensor 72 for adjusting image quality is disposed on the downstream side of the black image forming unit 2K.

The reference sensor 71 recognizes a predetermined mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. Each image forming unit 2Y, 2M, 2C, 2K is configured to start image formation according to an instruction from the image formation control unit 80 based on the recognition of the reference signal.
The image density sensor 72 detects a density control toner image (toner patch) described later. The image forming control unit 80 adjusts the operating conditions of the image forming units 2Y, 2M, 2C, and 2K based on the detection result of the density control toner image detected by the image density sensor 72, and the image forming unit described later. The density of toner images (image forming toner images 101a and 101b in FIG. 2 described later) is adjusted.

  Further, in the image forming apparatus 1 according to the present embodiment, as a paper transport system, the paper storage unit 50 that stores the paper P, and the paper P stored in the paper storage unit 50 is taken out and transported at a predetermined timing. The pickup roll 51, the conveyance roll 52 that conveys the sheet P fed out by the pickup roll 51, the sheet conveyance path 53 that feeds the sheet P conveyed by the conveyance roll 52 to the secondary transfer unit 20, and the secondary transfer roll 22 A conveyance belt 55 that conveys the sheet P conveyed after the next transfer to the fixing unit 60 and a fixing entrance guide 56 that guides the sheet P to the fixing unit 60 are provided.

  The fixing unit 60 includes a heating roll 61 containing a heating source such as a halogen lamp, and a pressure roll 62 pressed against the heating roll 61. Fixing is performed by passing the paper P on which the toner image is transferred between the heating roll 61 and the pressure roll 62.

  In the image forming apparatus 1 according to the present embodiment, in addition to the image forming toner image secondarily transferred to the paper P, a density control toner image (toner) formed in the gap between successive image forming toner images. A gap toner image (a patch toner image 102 in FIG. 2 described later), an end toner image (toner band) formed on an end of the intermediate transfer belt 15 (for an end portion in FIG. 2 described later) The toner images 103a and 103b) are formed and used to control the image forming apparatus 1. Note that when the image forming toner image, the density control toner image, and the edge toner image are not distinguished from each other, they are referred to as toner images. An image forming toner image, a density control toner image, an edge toner image, and the like are referred to as a plurality of types of toner images.

Next, a basic image forming process of the image forming apparatus 1 in the present embodiment will be described. Here, an image forming process using the image forming toner image will be described, and the gap toner image and the edge toner image will be described later.
In the image forming apparatus 1 shown in FIG. 1, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to predetermined image processing by an image processing device (not shown). The image forming operation is executed by the image forming units 2Y, 2M, 2C, and 2K. In the image processing apparatus, predetermined images such as shading correction, position shift correction, brightness / color space conversion, gamma correction, frame deletion, color editing, moving editing, and other various image editing are applied to the input image data. Processing is performed. The image data that has undergone image processing is converted into color material gradation data of four colors, Y, M, C, and K, and is output to the laser exposure unit 13.

  The laser exposure unit 13 irradiates each photosensitive drum 11 of the image forming units 2Y, 2M, 2C, and 2K with, for example, an exposure beam Bm emitted from a semiconductor laser according to the input color material gradation data. Yes. In each of the photosensitive drums 11 of the image forming units 2Y, 2M, 2C, and 2K, the surface is charged by the charger 12, and then the surface is scanned and exposed by the laser exposure unit 13 to form an electrostatic latent image. The formed electrostatic latent images are developed as image forming toner images of respective colors Y, M, C, and K by the developing devices 14 of the respective image forming units 2Y, 2M, 2C, and 2K.

  The image forming toner images of the respective colors formed on the photosensitive drums 11 of the image forming units 2Y, 2M, 2C, and 2K are intermediated at the primary transfer unit 10 where the photosensitive drums 11 and the intermediate transfer belt 15 are in contact with each other. Transferred onto the transfer belt 15. More specifically, in the primary transfer unit 10, the voltage (primary transfer bias) of the charging polarity (negative) and the reverse polarity (positive) of the image forming toner is applied to the substrate of the intermediate transfer belt 15 by the primary transfer roll 16. In addition, primary transfer is performed by sequentially superimposing the image forming toner images on the surface of the intermediate transfer belt 15.

  When the image forming toner images of the respective colors are sequentially primary-transferred onto the surface of the intermediate transfer belt 15, the image forming toner images of the respective colors are superimposed and conveyed to the secondary transfer unit 20. The When the superimposed image forming toner image is conveyed to the secondary transfer unit 20, in the paper conveying system, the pickup roll 51 is synchronized with the timing at which the superimposed image forming toner image is conveyed to the secondary transfer unit 20. Rotates, and a paper P having a predetermined size is supplied from the paper storage unit 50. The paper P supplied by the pickup roll 51 is transported by the transport roll 52, and reaches the secondary transfer unit 20 through the paper transport path 53. Before reaching the secondary transfer unit 20, the paper P is temporarily stopped, and a registration roll (not shown) rotates in accordance with the movement timing of the intermediate transfer belt 15 holding the superimposed image forming toner image. Thus, the position of the paper P and the position of the superimposed image forming toner image are aligned.

  In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the backup roll 25 via the intermediate transfer belt 15. At this time, the sheet P conveyed at the same timing is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At that time, a voltage (secondary transfer bias) having the same polarity as the charging polarity (negative) of the toner is supplied from the secondary transfer power supply 27 to the backup roll 25 via the power supply roll 26. Then, a secondary transfer bias is formed between the secondary transfer roll 22 and the backup roll 25, and the unfixed superimposed image forming toner image held on the intermediate transfer belt 15 is transferred to the secondary transfer unit 20. In FIG. 2, the electrostatic transfer is collectively performed on the paper P.

Thereafter, the sheet P on which the superimposed image forming toner image has been electrostatically transferred is transported in a state of being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and downstream of the secondary transfer roll 22 in the sheet transport direction. Is conveyed to a conveyor belt 55 provided on the conveyor. The conveyance belt 55 conveys the paper P to the fixing unit 60 in accordance with the conveyance speed in the fixing unit 60. The unfixed image forming toner image on the paper P conveyed to the fixing unit 60 is fixed on the paper P by being subjected to a fixing process by heat and pressure by the fixing unit 60 and becomes a fixed image. The paper P on which the fixed image is formed is conveyed to a paper discharge storage unit (not shown) provided in the discharge unit of the image forming apparatus 1.
On the other hand, after the transfer onto the paper P is completed, the residual toner remaining on the intermediate transfer belt 15 is conveyed along with the movement of the intermediate transfer belt 15 and removed from the intermediate transfer belt 15 by the intermediate transfer belt cleaner 35. The

[Toner image]
FIG. 2 is a diagram illustrating an example of a toner image on the intermediate transfer belt 15. FIG. 2 shows a part of the surface of the intermediate transfer belt 15 as viewed from the secondary transfer roll 22 side in the secondary transfer portion 20 shown in FIG. The intermediate transfer belt 15 moves in the arrow B direction. When the image forming apparatus 1 corresponds to, for example, a sheet P of A3 Nobi (329 mm × 483 mm or the like), the width of the intermediate transfer belt 15 is set to 380 mm.

  As shown in FIG. 2, on the intermediate transfer belt 15, in addition to the image forming toner images 101a and 101b transferred to the paper P, the density provided between the image forming toner images 101a and 101b (gap). A gap toner image 102 such as a control toner image, and end toner images 103 a and 103 b discretely provided at both ends of the intermediate transfer belt 15 are held.

The image forming toner image 101a and the image forming toner image 101b are shown in different sizes in FIG. Both of these are transferred to the paper P, but here the case where the sizes (sizes) of the paper P are different is shown. For example, the image forming toner image 101a corresponds to an A4 size paper P, and the image forming toner image 101b corresponds to an A3 size paper P.
In this embodiment, the image forming toner images 101a and 101b are formed at the center in the width direction of the intermediate transfer belt 15 as an example.
When the image forming toner images 101 a and 101 b are not distinguished from each other, they are referred to as image forming toner images 101.

The gap toner image 102 is provided in the gap between the continuous image forming toner images 101. The gap toner image 102 may have a density control toner image that can be read by the image density sensor 72 for image quality adjustment. The density control toner image is formed so as to face the image density sensor 72.
It should be noted that the density control toner image is not necessarily required between successive image forming toner images 101. For example, it may be provided for each of a plurality of image forming toner images 101, or may be provided when density control of an image to be formed is required.
However, even in the case where no density control toner image is provided, a toner image for suppressing the wobbling of the secondary transfer roll 22 is provided in the same manner as the edge toner image 103 described later. Since these toner images are provided in the gap between the image forming toner images 101, they are referred to as gap toner images 102.

  In FIG. 2, the gap toner image 102 is continuously provided from the left end portion to the right end portion of the intermediate transfer belt 15. For example, the length of the intermediate transfer belt 15 in the moving direction (arrow B direction) is 3 mm, and the length of the intermediate transfer belt 15 in the width direction is 380 mm. However, the gap toner image 102 may be divided into a plurality of parts.

The end toner images 103 a and 103 b are provided outside the image forming toner image 101 at both ends in the width direction of the intermediate transfer belt 15. That is, the end toner images 103a and 103b are provided at symmetrical positions with a line having the same shape connecting the center in the width direction of the intermediate transfer belt 15 in the movement direction (B direction) as an axis.
The end toner images 103a and 103b are discretely provided with respect to the moving direction (arrow B direction) of the intermediate transfer belt 15.
The lengths of the intermediate transfer belt 15 in the width direction of the end toner images 103a and 103b are provided so as to be different corresponding to the widths of the image forming toner images 101a and 101b. Since the image forming toner image 101a corresponding to the A4 size paper P has a smaller length in the width direction than the image forming toner image 101b corresponding to the A3 size paper P, it corresponds to the image forming toner image 101a. The length in the width direction of the end toner image 103a is set to be longer than the length in the width direction of the end toner image 103b corresponding to the image forming toner image 101b.
That is, the end toner images 103a and 103b are dummy toner images provided so as to cover an area not occupied by the image forming toner image 101 on the intermediate transfer belt 15.
Note that when the edge toner images 103a and 103b are not distinguished from each other, they are referred to as edge toner images 103.

Next, referring to FIG. 2, the electric field (bias) applied by the secondary transfer power source 27 between the secondary transfer roll 22 and the backup roll 25 will be described.
When the image forming toner images 101 a and 101 b transferred to the paper P pass through the secondary transfer unit 20, the secondary transfer power supply 27 supplies a secondary transfer bias that is a negative voltage to the backup roll 25. The secondary transfer bias, which is a negative voltage, acts in the direction of pressing the image forming toner images 101a and 101b with the negative polarity toner on the intermediate transfer belt 15 against the paper P side.
The secondary transfer bias acts on the end toner images 103 a and 103 b in the direction in which the end toner images 103 a and 103 b are pressed against the secondary transfer roll 22. The edge toner images 103a and 103b are directly pressed against the secondary transfer roll 22 because there is no corresponding paper P.

That is, while the negative transfer secondary transfer bias is being applied, the image forming toner images 101a and 101b are transferred onto the paper P at the central portion (sheet passing portion) of the secondary transfer roll 22, and the secondary transfer is performed. At both end portions (non-sheet passing portions) of the roll 22, the end toner images 103 a and 103 b are transferred to the secondary transfer roll 22. Since the sheet P is interposed in the central portion (sheet passing portion), the image forming toner images 101 a and 101 b are not transferred to the secondary transfer roll 22.
On the other hand, the end toner images 103 a and 103 b pressed against the secondary transfer roll 22 are transferred to the secondary transfer roll 22, but a part of the toner images 103 a and 103 b are not transferred on the intermediate transfer belt 15. To remain.
The image forming toner images 101a and 101b also remain on the intermediate transfer belt 15 without being 100% transferred to the paper P.
The state of the secondary transfer unit 20 is a “secondary transfer bias mode” in which the secondary transfer power source 27 supplies a secondary transfer bias having a negative voltage to form a secondary transfer bias in the secondary transfer unit 20. is there.

When the gap toner image 102 such as the density control toner image passes through the secondary transfer unit 20, the secondary transfer power supply 27 supplies a positive voltage non-transfer bias to the backup roll 25. As a result, the non-transfer bias formed in the secondary transfer portion 20 acts in a direction in which the gap toner image 102 formed of negative toner is pressed against the intermediate transfer belt 15 side. That is, the gap toner image 102 remains on the intermediate transfer belt 15.
However, since there is no corresponding paper P in the gap toner image 102, the gap toner image 102 contacts the secondary transfer roll 22. Therefore, a part of the gap toner image 102 adheres (transfers) to the secondary transfer roll 22.
The state of the secondary transfer unit 20 is a “non-transfer bias mode” in which the secondary transfer power supply 27 supplies a non-transfer bias having a positive voltage to form a non-transfer bias in the secondary transfer unit 20.

  As described above, the secondary transfer power supply 27 switches and supplies a positive voltage (secondary transfer bias) and a negative voltage (non-transfer bias).

Here, the reason for providing the edge toner image 103 will be described.
As described above, when the image forming toner image 101 is transferred to the paper P, the secondary transfer bias is applied with the intermediate transfer belt 15 sandwiched between the secondary transfer roll 22 and the backup roll 25.
When the edge toner image 103 is not provided, both ends (non-sheet passing portion) where the paper P of the secondary transfer roll 22 does not pass are discharged compared to the central portion (paper passing portion) through which the paper P passes. Prone to occur. That is, the sheet P is interposed in the sheet passing portion, so that it is difficult for electric discharge to occur. On the other hand, the sheet P is not interposed in the non-sheet passing portion, and the intermediate transfer belt 15 and the secondary transfer roll 22 are directly opposed. Therefore, discharge is likely to occur.

  When discharge occurs, discharge products such as nitrogen oxide (NOx) adhere to the secondary transfer roll 22. The surface energy of the secondary transfer roll 22 increases due to the adhesion of these discharge products, so that the contact friction between the secondary transfer roll 22 and the cleaning blade 42 of the roll cleaner 40 increases, and the cleaning blade 42 becomes secondary. The wobbling occurs due to the rotation force of the transfer roll 22. As a result, a gap is formed between the secondary transfer roll 22 and the cleaning blade 42, and the toner attached (transferred) on the secondary transfer roll 22 is not removed and is attached to the back surface of the paper P.

Therefore, an end toner image 103 is provided at both end portions (non-sheet passing portion) of the intermediate transfer belt 15 where the image forming toner image 101 is not formed, and the toner is attached (transferred) to the secondary transfer roll 22 to form an inorganic material. By supplying toner including an external additive to the cleaning blade 42, the external additive is interposed between the secondary transfer roll 22 and the cleaning blade 42, reducing contact friction of the cleaning blade 42, and adhering discharge. The removal property of the product is improved and the deposition of the discharge product is suppressed.
Note that the end toner image 103 adheres (transfers) onto the secondary transfer roll 22 and is removed by the roll cleaner 40.

  As described above, since the gap toner image 102 and the edge toner image 103 are provided to suppress the wobbling of the cleaning blade 42, they are set based on the effect of suppressing the wobbling of the cleaning blade 42 and the consumption of toner. . Here, as shown in FIG. 2, the end toner images 103 are discretely provided along the moving direction of the intermediate transfer belt 15.

Similarly, the toner image 102 for the gap also suppresses contact friction of the cleaning blade 42 and accumulation of discharge products such as nitrogen oxide (NOx) by the toner adhered (transferred) to the secondary transfer roll 22. I am doing so.
At this time, the secondary transfer unit 20 is in a “non-transfer bias mode” in which the secondary transfer power supply 27 supplies a non-transfer bias having a positive voltage to form a non-transfer bias in the secondary transfer unit 20. The gap toner image 102 is pressed against the intermediate transfer belt 15 side. Therefore, the amount of toner that adheres (transfers) from the gap toner image 102 to the secondary transfer roll 22 is smaller than the amount of toner that adheres (transfers) from the end toner image 103 to the secondary transfer roll 22.

As described above, when the edge toner image 103 is provided in order to prevent the cleaning blade 42 from curling due to the unevenness caused by the wear of the surface of the secondary transfer roll 22, the edge toner image 103 is provided. Compared with the case where there is no toner, the amount of toner removed by the roll cleaner 40 increases.
When the accumulation portion 46 in the cleaner housing 44 is filled with the removed toner (waste toner), the waste toner overflows from the cleaner housing 44. Then, the image quality of the formed image is deteriorated or the back surface of the paper P is stained.

In order to suppress this, it is necessary to accurately grasp the amount of waste toner accumulated in the accumulation portion 46 in the cleaner housing 44 of the roll cleaner 40.
For this reason, the roll cleaner 40 is provided with means (sensor) for measuring the amount of waste toner accumulated in the accumulation portion 46 in the cleaner housing 44, and the roll cleaner 40 is replaced based on the measured amount of waste toner. It is also conceivable to clean the accumulating portion 46 in the cleaner housing 44. However, in this method, means for measuring the amount of waste toner accumulated in the accumulation unit 46 is provided, which increases the cost and enlarges the roll cleaner 40.

  Further, it is conceivable to provide a mechanism (discharge mechanism) for discharging waste toner accumulated in the accumulation portion 46 of the cleaner housing 44 in the roll cleaner 40 to the outside. In this case as well, a waste toner discharge mechanism is provided, which increases the cost and enlarges the roll cleaner 40.

Therefore, it is preferable that the amount of waste toner accumulated in the accumulation portion 46 of the cleaner housing 44 in the roll cleaner 40 can be estimated without using a measuring unit. Further, since the amount of waste toner accumulated in the roll cleaner 40 is smaller than that of the drum cleaner 17 and the intermediate transfer belt cleaner 35, the waste toner accumulated in the accumulation unit 46 without providing a mechanism for discharging to the outside. When the amount reaches a predetermined amount, the roll cleaner 40 can be replaced.
In this case, the secondary transfer roll 22 and the roll cleaner 40 may be replaced as a unit.

Therefore, in the present embodiment, the amount of waste toner removed by the roll cleaner 40 and accumulated in the accumulation unit 46 in the cleaner housing 44 is estimated from the information (image information) that defines the image to be formed. When the amount of waste toner reaches a predetermined amount, the secondary transfer roll 22 and the roll cleaner 40 are replaced as a unit.
In this case, in order to efficiently use the accumulating portion 46 in the cleaner housing 44, it is required to accurately estimate the amount of accumulated waste toner.

  As described above, the toner adhering (transferring) from the intermediate transfer belt 15 onto the secondary transfer roll 22 is mainly the edge toner images 103a and 103b. A part of the gap toner image 102 also adheres (transfers) to the secondary transfer roll 22.

Table 1 is a table showing an example of the ratio (transfer rate T) of toner adhering (transferring) to the secondary transfer roll 22. The secondary transfer unit 20 has three operation modes as described above. That is, the “secondary transfer bias mode” (referred to as “secondary transfer bias” in Table 1) in which the secondary transfer power supply 27 supplies a secondary transfer bias having a negative voltage, and the secondary transfer power supply 27 has a positive voltage. “Non-transfer bias mode” for supplying a non-transfer bias (referred to as “non-transfer bias” in Table 1), “Retract mode” where the secondary transfer roll 22 and roll cleaner 40 are retracted (referred to as “retract” in Table 1). .) In the “retract mode”, the secondary transfer power supply 27 does not supply either positive or negative voltage. Therefore, the electric field (bias) in the “retract mode” may be zero.
As shown in Table 1, the ratio (transfer rate T) of the toner image transferred to the secondary transfer roll 22 varies depending on the operation mode.

As described above, in the “secondary transfer bias mode”, the image forming toner image 101 is transferred onto the paper P as shown in FIG. Therefore, the transfer rate T of the image forming toner image 101 to the secondary transfer roll 22 is 0% for each of the colors Y, M, C, and K.
In the “secondary transfer bias mode”, the end toner image 103 is transferred (transferred) to the secondary transfer roll 22. At this time, the transfer rate T of the edge toner image 103 to the secondary transfer roll 22 is 86%, 86%, 91%, and 93% for Y, M, C, and K, respectively. The remainder obtained by subtracting each transition rate T from 100% remains on the surface of the intermediate transfer belt 15.

  Next, in the “non-transfer bias mode” in which the secondary transfer power supply 27 supplies a non-transfer bias that is a positive voltage, most of the toner in the gap toner image 102 such as a density control toner image is intermediate transferred. It remains on the belt 15. However, a part of the toner in the gap toner image 102 moves to the secondary transfer roll 22. At this time, the transfer rate T of the toner of the gap toner image 102 to the secondary transfer roll 22 is 4.00%, 4.50%, and 4.75% with respect to Y, M, C, and K, respectively. 5.00%. The remainder obtained by subtracting each from 100% remains on the surface of the intermediate transfer belt 15.

In the “secondary transfer bias mode” and the “non-transfer bias mode”, the transfer rate T differs for each color because the adhesion force of each color toner to the intermediate transfer belt 15 and the secondary transfer roll 22 is different. It depends on the difference.
Further, the transition rate T shown in Table 1 varies depending on environmental conditions such as temperature and / or humidity of the secondary transfer unit 20. Therefore, the transition rate T may be corrected based on the environmental information regarding the environmental conditions measured by the environment measuring unit 28.

  In the “retract mode” in which the secondary transfer roll 22 and the roll cleaner 40 are integrally separated from the intermediate transfer belt 15, all of the toners of the image forming toner image 101, the edge toner image 103, and the gap toner image 102 are used. It does not adhere (migrate) to the secondary transfer roll 22. That is, the transfer rate T of each of the image forming toner image 101, the edge toner image 103, and the gap toner image 102 to the secondary transfer roll 22 is 0% regardless of the color.

  The “retract mode” is used in the recovery process when the paper P is jammed without being conveyed by the secondary transfer unit 20 (jam). In the recovery process, for example, the secondary transfer roll 22 and the roll cleaner 40 are retracted from the intermediate transfer belt 15 to remove the jammed paper P, and an unnecessary toner image remaining on the intermediate transfer belt 15 is removed. It is removed by the intermediate transfer belt cleaner 35. After that, the image forming apparatus 1 is returned to an operable state.

  In the “retract mode”, toner images (image forming toner image 101, gap toner image 102, etc.) formed on the respective photosensitive drums 11 of the image forming units 2Y, 2M, 2C, and 2K are transferred to the intermediate transfer belt. This is used when secondary transfer is not required even when primary transfer is performed to 15 (skip processing). For example, when adjusting the photosensitive drum 11, the laser exposure device 13, the developing device 14, etc., the density control toner image formed on the intermediate transfer belt 15 may be read by the image density sensor 72. Therefore, the secondary transfer roll 22 and the roll cleaner 40 are retracted from the intermediate transfer belt 15 so that toner does not adhere (transfer) to the secondary transfer roll 22.

  The image forming control unit 80 (CPU 81) in the image forming apparatus 1 controls the image forming units 2Y, 2M, 2C, and 2K to execute an image forming operation. Therefore, the number of pixels for each color of the toner image formed on each photosensitive drum 11 can be calculated (taken out) as image information. In the following description, it is assumed that the image information is the number of pixels (pixels). However, the image information may be corrected based on the size and density of the pixels. That is, the image information only needs to correspond to the amount of toner that forms the toner image.

Then, if the calculated number of pixels (pixels) and the transition rate T for each color set by the operation mode of the secondary transfer unit 20 are multiplied and accumulated, the accumulation unit 46 of the cleaner housing 44 in the roll cleaner 40 is accumulated. Can be estimated.
Then, the time (timing) for replacing the roll cleaner 40 may be managed based on the accumulated amount of waste toner.
The transition rate T shown in Table 1 may be stored in the MEM 82 provided in the image formation control unit 80 and read by the CPU 81 based on the operation mode of the secondary transfer unit 20.

  In this embodiment, since the transfer rate T of the toner that adheres (transfers) to the secondary transfer roll 22 is set according to the operation mode of the secondary transfer unit 20, the transfer is performed regardless of the operation mode of the secondary transfer unit 20. Compared with the case where the rate T is set, the amount of waste toner accumulated in the accumulation portion 46 of the cleaner housing 44 can be estimated with higher accuracy.

  Next, a method of managing the roll cleaner 40 by estimating the amount of waste toner accumulated in the accumulation portion 46 of the cleaner housing 44 (hereinafter referred to as waste toner amount Q) by the method described above will be described. In the present embodiment, the waste toner amount Q accumulated in the accumulation portion 46 of the cleaner housing 44 is monitored, and an example of the first notification is given regarding the replacement timing of the roll cleaner 40 (including the secondary transfer roll 22). Two types of notifications are issued: “exchange notice” and “exchange instruction” as an example of the second notification. These notifications are issued, for example, from the image formation control unit 80 (CPU 81) as a display on the UI unit 90 and / or an alarm issued by the UI unit 90.

Here, the “replacement notice” is issued when the waste toner amount Q stored in the storage unit 46 reaches a first threshold waste toner amount Q1 as an example of the first threshold value. Notifies that the storage portion 46 of the cleaner housing 44 is not full, but informs that a roll cleaner 40 (including the secondary transfer roll 22) for replacement should be prepared.
On the other hand, the “exchange instruction” is an alarm issued when the waste toner amount Q stored in the storage unit 46 reaches a second threshold waste toner amount Q2 as an example of the second threshold value. is there. If the storage unit 46 of the cleaner housing 44 is full and the use of the image forming apparatus 1 is continued thereafter, waste toner overflows from the storage unit 46, the image quality of the formed image deteriorates, or the back surface of the paper P Inform them that there is a risk of contamination. The image forming apparatus 1 is configured not to execute a new image forming operation unless the roll cleaner 40 (including the secondary transfer roll 22) is replaced.
Therefore, the second threshold waste toner amount Q2 is set to be larger than the first threshold waste toner amount Q1 although it is smaller than the amount set based on the capacity of the storage unit 46.
The “exchange notice” continues to be issued until the “exchange instruction” is issued. However, even if the “replacement notice” is issued, if the roll cleaner 40 (including the secondary transfer roll 22) is replaced before the “replacement instruction” is issued, the “replacement notice” is stopped. It has become so.

FIG. 3 is a diagram illustrating an example of a region of the MEM 82 of the image formation control unit 80. Constants and variables for managing the roll cleaner 40 are stored at addresses # 0 to # 12 of the MEM 82.
At the address # 0 of the MEM 82, a waste toner amount Q accumulated as being accumulated in the accumulation unit 46 of the cleaner housing 44 in the roll cleaner 40 is stored. The waste toner amount Q is integrated as will be described later.
A first threshold waste toner amount Q1 as a constant is stored at address # 1 of MEM82. Address # 2 stores a second threshold waste toner amount Q2 as a constant.
At the address # 3 of the MEM 82, an operation mode (hereinafter referred to as an operation mode M) that is an operation state of the secondary transfer unit 20 is stored. The operation mode M is rewritten as the operation state of the secondary transfer unit 20 changes. As described above, the operation mode M is the “secondary transfer bias mode”, the “non-transfer bias mode”, or the “retract mode”.
An exchange notice flag F is stored at address # 4. Here, if the replacement notice flag F is “0”, it means that “exchange notice” has not been issued, and if it is “1”, it means that “exchange notice” has already been issued.

Addresses # 5 to # 8 of the MEM 82 store the transition rate T for each color of the edge toner image 103 in the “secondary transfer bias mode” shown in Table 1. In FIG. 3, the values in the example shown in Table 1 are shown.
Addresses # 9 to # 12 of the MEM 82 store the transition rate T for each color of the gap toner image 102 in the “non-transfer bias mode” shown in Table 1. In FIG. 3, the values in the example shown in Table 1 are shown.
As shown in Table 1, the transfer rate T of the image forming toner image 101 in the “secondary transfer bias mode”, the image forming toner image 101, the gap toner image 102, and the edge toner in the “retract mode”. Since the transition rate T of the image 103 is 0%, no region is provided in the MEM 82 in FIG. However, an area for storing these values may be provided in the MEM 82.

  FIG. 4 is an example of a flowchart for managing the roll cleaner 40 by estimating the amount Q of waste toner accumulated in the accumulation unit 46 of the cleaner housing 44.

A description will be given immediately after the roll cleaner 40 (including the secondary transfer roll 22) in which the waste toner is not accumulated in the accumulation portion 46 of the cleaner housing 44 is replaced. Here, description will be made assuming that the CPU 81 of the image formation control unit 80 in the image forming apparatus 1 performs control.
In step S101 (denoted as S101 in FIG. 4 and the same applies to other cases), the CPU 81 sets the waste toner amount Q at address # 0 of the MEM 82 to 0 and sets the replacement notice flag F to “0”. Set.
Next, in step S102, image forming work is executed (image forming work is executed). The image forming operation is to form any one of the image forming toner image 101, the gap toner image 102, and the edge toner image 103 in the image forming units 2Y, 2M, 2C, and 2K, and these are formed on the intermediate transfer belt 15. The toner image 101 is transferred, and the secondary transfer unit 20 transfers the image forming toner image 101 onto the paper P.

In step S103, the number of pixels of the toner image formed by executing the image forming operation in step S102 is acquired. Here, the number of pixels (pixels) is acquired for each toner image (image forming toner image 101, gap toner image 102, edge toner image 103) divided into Y, M, C, and K.
Here, since the image formation control unit 80 (CPU 81) controls the image forming operation, the number of pixels for each toner image can be easily acquired.

In step S104, it is determined whether or not the operation mode M of the secondary transfer unit 20 is the “retract mode”. The operation mode M here is an operation mode when the toner image for which the number of pixels is calculated reaches the secondary transfer unit 20. In FIG. 4, “retract mode” is abbreviated as “retract”.
The operation mode M of the secondary transfer unit 20 is written in the area of the address # 3 of the MEM 82 by the image formation control unit 80 (CPU 81) in accordance with the change in the operation state of the secondary transfer unit 20. Therefore, when the toner image for which the number of pixels is calculated reaches the secondary transfer unit 20, the CPU 81 acquires the operation mode M from the address # 3 of the MEM 82.
When the operation mode M is “retract mode” (in the case of Y), the process returns to step S102. That is, since there is no toner (waste toner) stored in the storage unit 46, it is not necessary to perform the processing after step S105.

On the other hand, when the operation mode M is not “retract mode” (in the case of N), the CPU 81 determines whether or not the operation mode M is “secondary transfer bias mode” (step S105). In FIG. 4, “secondary transfer bias mode” is abbreviated as “secondary transfer”.
If the operation mode M is the “secondary transfer bias mode” (in the case of Y), it is determined whether or not the toner image is the edge toner image 103 (step S106). In FIG. 4, the end toner image 103 is abbreviated as “for end”.
Here, it is assumed that the CPU 81 stores the number of pixels (pixels) and the type of toner image in a register or the like. Note that a region may be provided in the MEM 82 to store the number of pixels (pixels) and the type of toner image.
When the toner image is not the edge toner image 103 (in the case of N), it is the image forming toner image 101, and the toner transfer rate T is 0% as shown in Table 1. It returns to step S102 which is execution.
On the other hand, when the toner image is the edge toner image 103 (in the case of Y), the transfer rate T for each of Y, M, C, and K stored in the addresses # 5 to # 8 of the MEM 82 is read. Multiply (multiply) the calculated numbers of Y, M, C, and K pixels. Then, the sum (Σ) of the multiplied values is set as the waste toner increase amount ΔQ (step S107).

When the operation mode M is not “secondary transfer bias mode” (in the case of N), the operation mode M is “non-transfer bias mode”. Therefore, the toner image in this case is the gap toner image 102.
In the case of the gap toner image 102, the transfer rate T for each of Y, M, C, and K stored in the addresses # 9 to # 12 of the MEM 82 is acquired, and the calculated Y, M, C, and K are calculated. Is multiplied (multiplied) by the number of pixels. Then, the sum (Σ) of the values multiplied for each of Y, M, C, and K is calculated as the waste toner increase amount ΔQ (step S108).
In step S107 and step S108, the address # of the MEM 82 in which the migration rate T is stored is shown in [].

  When the waste toner increase amount ΔQ is calculated in step S107 or step S108, the waste toner amount Q at address # 0 of the MEM 82 is read in step S109, and the waste toner increase amount ΔQ is added to the waste toner amount Q. The new waste toner amount Q is stored at address # 0 of the MEM 82.

  Next, in step S110, it is determined whether or not the waste toner amount Q is equal to or greater than the first threshold waste toner amount Q1. When the waste toner amount Q is less than the first threshold waste toner amount Q1 (in the case of N), the process returns to the execution of the image forming operation in step S102.

On the other hand, when the waste toner amount Q is equal to or greater than the first threshold waste toner amount Q1 (in the case of Y), it is determined in step S111 whether or not the replacement notice flag F is “0”. If the replacement notice flag F is “0” (in the case of Y), the timing (timing) for replacing the roll cleaner 40 is close to the UI unit 90 of the image forming apparatus 1 in step S112. Issue a “exchange notice” to notify you.
Then, the replacement notice flag F is changed from “0” to “1” (step S113).
Here, you may return to step S102, without transfering to step S114.

In step S114, it is determined whether or not the waste toner amount Q is equal to or greater than the second threshold waste toner amount Q2. When the waste toner amount Q is less than the second threshold waste toner amount Q2 (in the case of N), the process returns to step S102 to execute the next image forming operation.
In step S111, if the replacement notice flag F is not “0”, that is, if it is already “1” (N), the process proceeds to step S114.

  If the waste toner amount Q is equal to or greater than the second threshold waste toner amount Q2 in step S114 (in the case of Y), the roll cleaner 40 (secondary transfer roll) is transferred to the UI unit 90 of the image forming apparatus 1. The “exchange instruction” for informing the exchange (including 22) is issued (step S115).

In step S116, it is determined whether or not the exchange is completed (exchange completed). The completion of replacement may be notified to the image forming control unit 80 (CPU 81) by operating the UI unit 90 when the user completes replacement of the roll cleaner 40, or the roll cleaner 40 (secondary transfer roll 22). The switch is automatically pressed when the roll cleaner 40 (including the secondary transfer roll 22) is replaced, so that the image forming control unit 80 (CPU 81) has a switch. You may make it notify to. In this case, it is preferable that a means for preventing the roll cleaner 40 that needs to be replaced from being installed again without being replaced is provided.
Step S116 is repeated until the exchange is completed.

  On the other hand, when the replacement is completed (replacement completed) (in the case of Y), the process returns to step S101 to set the waste toner amount Q to 0 and the replacement notice flag F to “0”.

  In the present embodiment, since the first threshold waste toner amount Q1 and the second threshold waste toner amount Q2 are provided, the waste toner amount Q exceeds the first threshold waste toner amount Q1. , “Replacement notice” is notified. Therefore, a roll cleaner 40 (including the secondary transfer roll 22) for replacement may be prepared after receiving the notification of “exchange notice”. Accordingly, when waste toner is accumulated in the accumulation portion 46 of the cleaner housing 44 in the roll cleaner 40 and the image forming operation cannot be performed, a new roll cleaner 40 (including the secondary transfer roll 22) is prepared. In comparison with this, the period during which the image forming apparatus 1 cannot be used can be shortened. In order to prevent the image forming apparatus 1 from becoming unusable, a new roll cleaner 40 (including the secondary transfer roll 22) is replaced every time the roll cleaner 40 (including the secondary transfer roll 22) is replaced. There is no need to prepare.

  Further, the amount of waste toner that can be accumulated in the accumulating portion 46 in the cleaner housing 44 of the roll cleaner 40, that is, the capacity of the accumulating portion 46 is set in consideration of the replacement timing of the secondary transfer roll 22. It can be set to replace the roll cleaner 40 in accordance with the time when the roll 22 should be replaced. Therefore, even if the secondary transfer roll 22 and the roll cleaner 40 are configured and replaced as a unit, both the secondary transfer roll 22 and the roll cleaner 40 are time to be replaced, and both are wasted. There is nothing.

  In addition, when other than toner such as paper dust is mixed in the accumulating portion 46 in the cleaner housing 44 of the roll cleaner 40, a correction coefficient may be provided for the amount of waste toner estimated in the present embodiment. Further, the first threshold waste toner amount Q1 and the second threshold waste toner amount Q2 may be set in consideration of mixing of paper dust and the like.

In the present embodiment, the transition rate T is set for each color. However, when there is no need to divide the difference in the transition rate T for each color, the transition rate T may be set for the operation mode of the secondary transfer unit 20 without being divided for each color.
In the present exemplary embodiment, the image forming toner image 101, the gap toner image 102, and the edge toner image 103 are described as the toner images. However, other toner images may be provided that are necessary for controlling the image forming apparatus 1.

As described above, the transfer rate T of the toner adhering (transferring) to the secondary transfer roll 22 varies depending on the operation state (operation mode) of the secondary transfer unit 20. That is, the transition rate T is set by the electric field (bias) applied to the toner image. Therefore, the transition rate T corresponding to the electric field applied to the toner image may be multiplied by the number of pixels of the toner image.
When the toner image is transferred to the paper P, the transition rate T may be 0%.

  In the present embodiment, the migration rate T is set in advance and stored in the MEM 82. The transition rate T of the edge toner image 103 also varies depending on the thickness of the paper P, that is, the gap between the intermediate transfer belt 15 and the secondary transfer roll 22. Therefore, the CPU 81 of the image formation control unit 80 may set the calculation formula including other image formation conditions such as the operation mode of the secondary transfer unit 20 and the thickness of the paper P.

  In the present embodiment, the roll cleaner 40 (including the secondary transfer roll 22) is described as being replaced. However, the roll cleaner 40 may be replaced without including the secondary transfer roll 22.

  Further, in the present embodiment, the roll cleaner 40 of the secondary transfer roll 22 in the secondary transfer unit 20 that transfers the toner image held by the intermediate transfer belt 15 onto the paper P has been described. However, the present invention can also be applied to a transfer roll cleaner for transferring a toner image held by the photosensitive drum 11 onto the paper P.

  In this embodiment, the image formation control unit 80 (CPU 81) included in the image forming apparatus 1 acquires the transition rate T, the image information, and the toner amount. However, a control device that executes these functions may be arranged outside the image forming apparatus 1 so that the image forming apparatus 1 and the control device are connected. At this time, the image forming apparatus 1 and the control apparatus may be connected via a communication network.

  In this embodiment, the toner has been described as having a negative polarity. However, when a positive polarity toner is used, the polarity of each of the secondary transfer bias and the non-transfer bias may be reversed.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 2Y, 2M, 2C, 2K ... Image forming unit, 10 ... Primary transfer part, 11 ... Photosensitive drum, 12 ... Charger, 13 ... Laser exposure device, 14 ... Developing device, 15 ... Intermediate transfer Belt, 16 ... primary transfer roll, 17 ... drum cleaner, 20 ... secondary transfer section, 22 ... secondary transfer roll, 25 ... backup roll, 26 ... feed roll, 27 ... secondary transfer power supply, 40 ... roll cleaner, 41 DESCRIPTION OF SYMBOLS ... Cleaning brush, 42 ... Cleaning blade, 43 ... Lubricant block, 44 ... Cleaner housing, 45 ... Support member, 50 ... Paper storage part, 60 ... Fixing part, 71 ... Reference sensor, 72 ... Image density sensor, 80 ... Image Formation control unit, 81... CPU, 82... MEM, 90... UI unit, 101, 101 a, 101 b .. Image forming toner image, 102. 3,103a, 103b ... end toner image, P ... paper, Q ... waste toner amount, Q1 ... first threshold amount of waste toner, Q2 ... second threshold amount of waste toner, T ... migration rate

Claims (9)

A toner image forming body on which a toner image is formed;
A transfer body onto which the toner image formed on the toner image forming body is transferred;
A transfer unit having a plurality of operation states, and transferring the toner image transferred to the transfer body to a transfer body in a predetermined operation state in the plurality of operation states;
Removing and accumulating means for removing and accumulating toner transferred to the transfer means from the toner image transferred to the transfer body;
A transfer rate acquisition unit that acquires a transfer rate at which toner transfers from the toner image transferred to the transfer body to the transfer unit in correspondence with each of the plurality of operation states of the transfer unit;
Image information acquisition means for acquiring image information defining the toner image;
An image forming apparatus comprising: a toner amount calculating unit that calculates a toner amount accumulated in the removal accumulating unit based on the image information acquired by the image information acquiring unit and the transfer rate acquired by the transfer rate acquiring unit.   2. The transfer rate acquired by the transfer rate acquiring unit is set based on an electric field applied to the toner image in each of the plurality of operation states of the transfer unit. Image forming apparatus.   The image forming apparatus according to claim 1, further comprising a contact / separation unit configured to set the transfer body and the transfer unit in contact with or separated from each other.   The image forming apparatus according to claim 3, wherein the plurality of operation states of the transfer unit include a state in which the transfer body set by the contact / separation unit and the transfer unit are separated from each other. A first threshold value, and a second threshold value that is larger than the first threshold value and smaller than the capacity at which the removal accumulation means can accumulate toner,
When the toner amount accumulated in the removal accumulation unit calculated by the toner amount calculation unit is greater than or equal to the first threshold value, the first notification is performed, and when the toner amount is greater than or equal to the second threshold value. The image forming apparatus according to claim 1, further comprising a notification unit that performs a second notification. Further comprising environmental information acquisition means for acquiring environmental information surrounding the transfer means;
The image forming apparatus according to claim 1, further comprising a shift rate correcting unit that corrects the shift rate based on the environmental information acquired by the environmental information acquiring unit. A toner image forming body on which a toner image is formed; a transfer body on which the toner image formed on the toner image forming body is transferred; and a plurality of operating states, and predetermined in the plurality of operating states. In an operating state, a transfer unit that transfers the toner image transferred to the transfer body to the transfer target, and a removal that removes and accumulates toner transferred to the transfer unit from the toner image transferred to the transfer body An image forming apparatus having storage means, or a control device connected to the image forming apparatus,
A transfer rate acquisition unit that acquires a transfer rate at which toner transfers from the toner image transferred to the transfer body to the transfer unit in correspondence with each of the plurality of operation states of the transfer unit;
Image information acquisition means for acquiring image information defining the toner image;
A toner amount calculating unit that calculates a toner amount accumulated in the removal accumulating unit from the image information acquired by the image information acquiring unit and the transfer rate acquired by the transfer rate acquiring unit. Control device.   The control device according to claim 7, further comprising contact / separation means for setting the transfer body and the transfer means in a contacted state or a separated state.   9. The control apparatus according to claim 8, wherein the plurality of operation states of the transfer unit include a state in which the transfer body set by the contact / separation unit and the transfer unit are separated from each other.

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