JP6532382B2 - Image forming device - Google Patents

Description

  The present invention relates to an image forming apparatus, and is applicable to, for example, an image forming apparatus adopting an electrophotographic method.

  Conventionally, in the image forming apparatus, the developer remaining on the surface of the photosensitive drum is collected for disposal.

  In Patent Document 1, a first storage chamber for storing an unused developer (hereinafter also referred to as “unused toner”) and a waste developer (hereinafter also referred to as “waste toner”) are accommodated. A developer cartridge is disclosed in which a second storage chamber is divided via a partition member. Unused toner is consumed for development, and the waste toner is conveyed to the second storage chamber. As the amount of waste developer increases, the partition member moves to the first storage chamber side, thereby expanding the space volume of the second storage chamber.

JP 2003-345116 A

  It is desirable to notify the timing when the storage amount of the waste toner is full or near full in the storage chamber for storing the waste toner. In that case, it is necessary to determine the waste toner storage rate. For example, the waste toner storage rate can be a ratio of the volume of the actual waste toner to the volume of the storage chamber for storing the waste toner.

  However, for example, as in the above-described prior art, when the partition member is movable and the volume of the storage chamber for storing the waste toner fluctuates according to the amount of waste developer, the waste toner accommodation rate is accurately performed. It is difficult to ask for For example, there is a method of determining the waste toner storage rate with the volume of the waste developer storage chamber as a fixed value. However, in such a case, in spite of the fact that the waste toner full display is shown, in fact the storage room has a storage capacity, and conversely, the storage room is full despite the fact that the storage room is full. There may be a case where the display is not output.

  In view of the above problems, when calculating the waste toner storage rate, the present invention actually takes into consideration the increase in the storage space volume that is variable when the storage space volume of the waste toner is variable. The waste toner storable space ratio is calculated so as to approach the waste toner storage ratio.

In order to solve the above problems, an image forming apparatus according to a first aspect of the present invention comprises (1) a first storage chamber for storing unused developer, and (2) a second storage for storing waste developer. a chamber, and (3) partition the space between the first housing chamber and the second accommodating chamber, the partition member to operate the space volume of the second containing chamber to expand large to so that, (4) the latent image bearing And (5) developing means for moving an unused developer in the first storage chamber to the latent image on the latent image carrier for development, and (6) waste remaining on the latent image carrier after transfer. Waste developer collecting means for collecting the developer in the second storage chamber, (7) Waste developer storable space volume of the second storage chamber, and volume of waste developer stored in the second storage chamber based on the bets, Bei calculation means for obtaining the waste developer storage ratio in the second accommodating chamber, and display means for displaying a receiving state of the waste developer in (8) the second accommodating chamber , Calculation means, based on the amount of developer is moved from the developing unit before transfer to the latent image carrier to obtain the expansion volume of the waste developer can accommodate the spatial volume of the second containing chamber, the display means Compares the waste developer storable space ratio in the second storage chamber with the threshold value based on the waste developer content obtained by the calculation means, and when the waste developer storable space percentage is less than the threshold, waste When a screen including a developer accommodating space ratio is displayed and the value of the present waste developer accommodating space obtained by the calculation means is larger than the value of the previous waste developer accommodating space In addition, the screen including the current waste developer accommodating space ratio is not displayed .
An image forming apparatus according to a second aspect of the present invention comprises (1) a first storage chamber for storing unused developer, (2) a second storage chamber for storing waste developer, and (3) a first Partitioning member for partitioning the space between the second storage chamber and the second storage chamber, and operating to expand the space volume of the second storage chamber, (4) latent image carrier, and (5) latent image carrier Developing means for moving the unused developer in the first storage chamber to the latent image above for development, and (6) collecting the residual developer remaining on the latent image carrier after transfer into the second storage chamber The second developer chamber based on the waste developer recovery means, (7) the volume of the developer developer storable space volume of the second developer chamber, and the volume of the waste developer developer accommodated in the second developer chamber. (8) display means for displaying the storage state of the waste developer in the second storage chamber, and the calculation means Based on the amount of developer transferred from the means to the latent image carrier, the enlarged volume of the waste developer storable space volume of the second storage chamber is determined, and the display means stores the waste developer obtained by the calculation means. Comparing the waste developer storable space percentage and the threshold in the second storage chamber based on the percentage, and displaying a screen including the waste developer storable percentage when the waste developer storable space percentage is less than the threshold; And when the value of the present waste developer accommodating space rate obtained by the calculation means is larger than the value of the previous waste developer accommodating space rate, the previous waste developer accommodating space rate is included. It is characterized by displaying a screen.

  According to the present invention, even if the space capacity for accommodating the waste toner is variable, based on the amount of developer attached to the latent image carrier before transfer and the amount of developer remaining on the latent image carrier after transfer, It is possible to calculate an accurate waste toner content rate and to display a waste toner full display in a form close to the actual waste toner content rate.

FIG. 1 is a schematic cross-sectional view showing a basic configuration of an image forming apparatus according to an embodiment. FIG. 2 is a schematic cross-sectional view showing the configuration of an image forming unit according to the embodiment. FIG. 6 is an explanatory view illustrating a waste toner conveyance structure in the image forming unit according to the embodiment. FIG. 2 is a block diagram showing a configuration of a control system of the image forming apparatus according to the embodiment. FIG. 6 is an explanatory view illustrating an initial state of accumulation of waste toner in a second storage chamber of the embodiment. FIG. 7 is an explanatory view for explaining an appearance of a middle stage of accumulation of waste toner in a second storage chamber of the embodiment. FIG. 6 is an explanatory view for explaining the state of full deposition of waste toner in the second storage chamber of the embodiment. It is an explanatory view explaining a waste toner accommodation possible space volume concerning an embodiment. It is an explanatory view explaining an example of an environmental field corresponding to temperature and humidity. FIG. 6 is an explanatory diagram for explaining a fog correction coefficient correspondence table according to the embodiment. It is an explanatory view explaining a reverse transfer efficiency correspondence table concerning an embodiment. 5 is a flowchart showing an operation of calculation processing of a waste toner storable space ratio and an operation of a remaining amount display processing and a remaining amount of the storage space of the waste toner in the image forming apparatus according to the embodiment. It is an explanatory view explaining conditions of an example using an image forming device concerning an embodiment, and a comparative example. FIG. 14 is an explanatory drawing for explaining the evaluation results of the waste toner storable space ratio of the image forming unit 10 W on the most downstream side in Example 1 and Comparative Examples 1 and 2. In the embodiment, when the average printing rate of YMCK is 60%, it is a diagram showing the accommodation state of the second accommodation chamber 54 at the time of continuous printing equivalent to 3000 sheets of A6 paper. FIG. 14 is an explanatory view for explaining evaluation results of the waste toner storable space ratio of the image forming unit 10W on the most downstream side in Embodiments 1 and 2; FIG. 6 is an explanatory view illustrating a concept of calculation processing of a waste toner accommodation rate by a calculation unit according to the embodiment. FIG. 6 is an explanatory view for explaining an amount of transfer residual toner of fog. FIG. 6 is an explanatory view for explaining an amount of transfer residual toner. FIG. 6 is an explanatory view for explaining an amount of reverse transfer toner.

(A) Main Embodiment Hereinafter, an embodiment of an image forming apparatus according to the present invention will be described in detail with reference to the drawings.

  In this embodiment, for example, an electrophotographic system is adopted, and the case where the present invention is applied to a printing apparatus for forming a color image is exemplified. Further, the transfer method of the printing apparatus of this embodiment exemplifies a case where an intermediate transfer method is adopted. Furthermore, in this embodiment, the case where the developer is a nonmagnetic one-component negatively chargeable toner is exemplified.

(A-1) Configuration of Embodiment FIG. 1 is a schematic cross-sectional view showing a basic configuration of an image forming apparatus 100 according to the embodiment.

  In FIG. 1, the image forming apparatus 100 forms an image of each color using developers of five colors of yellow (Y), magenta (M), cyan (C), black (K), and white (W), respectively. Image forming units 10Y, 10M, 10C, 10K, and 10W. The image forming units 10Y, 10M, 10C, 10K, and 10W are detachably attachable to the image forming apparatus 100. The image forming units 10Y, 10M, 10C, 10K, and 10W are arranged in one row in this order from the upstream to the downstream of the moving direction of the intermediate transfer belt 14.

  The image forming units 10Y, 10M, 10C, 10K, and 10W use developers of different colors, but the basic configuration is the same. Therefore, hereinafter, when describing the common configuration of the image forming unit, it will be described as "image forming unit 10".

  Although this embodiment exemplifies the case where five image forming units 10 are provided, the number of the image forming units 10, the arrangement order of the image forming units 10, and the like are not limited to FIG.

  The image forming apparatus 100 also includes a roll paper feeder 11, rewinder 12, cutter 13, intermediate transfer belt 14, primary transfer rollers 15Y, 15M, 15C, 15K, 15W, secondary transfer roller 16, backup roller 45, heating roller 17, a pressure roller 18, a belt cleaning member 43, and a belt waste toner storage portion 44.

  In the image forming apparatus 100, the roll paper feeder 11 carries and holds roll paper P as a print medium, and winds up the roll paper P on which the rewinder 12 is printed. Further, the cutter 13 cuts the roll paper P when printing of one page is completed. A conveyance roller (not shown) is disposed in the conveyance path of the roll paper P, and the conveyance roller conveys the roll paper P drawn from the roll paper feeder 11. In this embodiment, the width of the roll paper P in the main scanning direction is, for example, 105 mm. Of course, the print medium is not limited to the roll paper P. Also, the size of the print medium is not limited to this.

  The intermediate transfer belt 14 is an endless belt disposed under the image forming units 10Y, 10M, 10C, 10K, and 10W, and rotates in the arrow direction in FIG. Each of the image forming units 10Y, 10M, 10C, 10K, and 10W forms a developer image on the surface of the intermediate transfer belt 14 at the same timing. The developer images superimposed on the surface of the intermediate transfer belt 14 are conveyed to the secondary transfer roller 16 and the backup roller 45 by the rotation of the intermediate transfer belt 14.

  The primary transfer rollers 15Y, 15M, 15C, 15K, and 15W are provided on the opposite side of the image forming units 10Y, 10M, 10C, 10K, and 10W with the intermediate transfer belt 14 interposed therebetween. The primary transfer rollers 15Y, 15M, 15C, 15K, and 15W transfer the developer images formed by the image forming units 10Y, 10M, 10C, 10K, and 10W, respectively, onto the surface of the intermediate transfer belt 14.

  The backup roller 45 is provided inside the lower portion of the intermediate transfer belt 14. Further, the secondary transfer roller 16 is provided below the backup roller 45 and at a position facing the backup roller 45 with the intermediate transfer belt 14 interposed therebetween, and the developer image formed on the intermediate transfer belt 14 On the roll paper P.

  The belt cleaning member 43 scrapes the developer remaining on the intermediate transfer belt 14 from the intermediate transfer belt 14 after transfer by the secondary transfer roller 16. The toner scraped off by the belt cleaning member 43 is stored in the belt waste toner storage unit 44.

  Furthermore, when the developer image is secondarily transferred onto the surface of the roll paper P, the roll paper P carrying the developer image is conveyed to the heating roller 17 and the pressure roller 18. The developer on the surface of the roll paper P is fixed to the roll paper P by heat and pressure by the heating roller 17 and the pressure roller 18.

  FIG. 2 is a schematic cross-sectional view showing the configuration of the image forming unit 10 according to the embodiment.

  In FIG. 2, the image forming unit 10 according to the embodiment includes a photosensitive drum 19 as a latent image carrier, a charging roller 20 as a charging member, an exposure head 21 as an exposure member, and a developing roller 22 as a developer carrier. A supply roller 23 as a developer supply member, a development blade 24 as a developer regulation member, a charge cleaning roller 56, a charge removal light emitting unit 26, a cleaning member 25 as a waste developer cleaning member, a waste developer conveyance member A waste toner conveying member 50 and a toner cartridge 500 as a developer container are provided.

  In the image forming unit 10, a portion contributing to the development of the electrostatic latent image (a portion including the developing roller 22, the supply roller 23, and the developing blade 24) is referred to as a "developing device" or a "developing unit".

  Further, a portion for recovering residual toner from the surface of the photosensitive drum 19 (a portion including the cleaning member 25 and the waste toner conveying member 50) is referred to as “waste developer collecting means”.

  The image forming unit 10 has a cylindrical photosensitive drum 19 on which an electrostatic latent image is formed. The photosensitive drum 19 is rotated in one direction (counterclockwise direction in FIG. 1) by a motor driving force obtained from a drive motor control unit 40 (see FIG. 4) described later.

  Around the photosensitive drum 19, a charging roller 20, an exposure head 21, and a developing roller 22 are arranged. The charging roller 20 is applied with a predetermined voltage from a charging roller power supply 33 (see FIG. 4), which will be described later, rotates in accordance with the rotation of the photosensitive drum 19, and uniformly charges the surface of the photosensitive drum 19.

  The charging cleaning roller 56 is disposed in contact with the charging roller 20. The charging cleaning roller 56 is rotated following the rotation of the charging roller 20 or is rotated with a difference in peripheral speed, and remains on the surface of the charging roller 20. An external additive of toner and toner not used for development Scrape

  The exposure head 21 has LEDs (Light Emitting Diodes), which are a plurality of light emitting elements arranged in the main scanning direction (here, the rotational axis direction of the photosensitive drum 19), and a rod lens array. The exposure head 21 exposes the surface of the charged photosensitive drum 19 by focusing the light of the light emitting element emitting light according to the image data on the surface of the photosensitive drum 19 by means of a rod lens array. Form an electrostatic latent image.

  The developing roller 22 receives a predetermined voltage from a developing roller power supply 34 (see FIG. 4) described later, and rotates in the same direction as the photosensitive drum 19 at the contact portion with the surface of the photosensitive drum 19. Toner is attached to the electrostatic latent image formed on the surface 19 and developed.

  Further, the supply roller 23 and the developing blade 24 are disposed adjacent to the developing roller 22.

  The supply roller 23 receives a predetermined voltage from a supply roller power supply 35 (see FIG. 4) described later, rotates in the opposite direction of the development roller 22 at the contact portion with the development roller 22, and develops the surface of the development roller 22. Supply the agent.

  The developing blade 24 is disposed so as to be pressed against the surface of the developing roller 22. The developing blade 24 regulates the thickness of the developer layer (toner layer) and forms a thin toner layer on the surface of the developing roller 22. A predetermined voltage is applied to the developing blade 24 from a supply roller power supply 35 (see FIG. 4) described later.

  When the image forming unit 10 is mounted on the image forming apparatus 100, the photosensitive drum 19 contacts the intermediate transfer belt 14, and the primary transfer roller 15 is disposed on the opposite side of the photosensitive drum 19 with the intermediate transfer belt 14 interposed therebetween. Be done. A predetermined voltage is applied to the primary transfer roller 15 from a transfer roller power source 32 (see FIG. 4) described later, and the developer image (toner image) formed on the surface of the photosensitive drum 19 is transferred onto the intermediate transfer belt 14. Transcribe.

  A cleaning member 25 is provided downstream of the photosensitive drum 19 in the rotational direction. The cleaning member 25 is in contact with the surface of the photosensitive drum 19 and removes the developer remaining on the surface of the photosensitive drum 19 after transfer.

  Immediately below the cleaning member 25, a waste toner conveyance member 50 is provided. The waste toner conveying member 50 conveys the developer removed from the surface of the photosensitive drum 19 by the cleaning member 25 toward a waste toner chamber 54 containing waste toner as described later.

  In the rotational direction of the photosensitive drum 19 and on the downstream side of the cleaning member 25, the static elimination light emitting unit 26 is disposed. The charge removing light emitting unit 26 removes the residual charge remaining on the surface of the photosensitive drum 19 without contacting the photosensitive drum 19. For example, the static elimination light emission unit 26 is configured of an LED or the like.

  The toner cartridge 500 may or may not be detachable from the main body of the image forming unit 10, and may be integrally formed with the main body of the image forming unit 10.

  The toner cartridge 500 includes a first storage chamber 47 for storing unused toner, a second storage chamber 54 for storing waste toner, and a space between the first storage chamber 47 and the second storage chamber 54. And a partitioning member 52 for partitioning.

  The partition member 52 sorts the space so that the unused toner in the first storage chamber 47 and the waste toner in the second storage chamber 54 do not mix, and the first storage chamber 47 and the second storage chamber 47 It is a member that changes the volume of the storage chamber 54.

  The partition member 52 is a member molded of a synthetic resin film, and the end of the partition member 52 is closely fixed to the inner wall surface of the toner cartridge 500. In addition, although the raw material of the partition member 52 is not specifically limited, For example, the partition member 52 applies what was shape | molded by the LDPE (low density polyethylene) film about 0.1 mm-0.4 mm in film thickness. it can.

  Unused toner stored in the first storage chamber 47 is used for image formation. Therefore, unused toner is discharged from the first storage chamber 47 each time an image forming process is performed. On the other hand, waste toner remaining on the surface of the photosensitive drum 19 is scraped off by the cleaning member 25 during the image forming process. The waste toner scraped off by the cleaning member 25 is transported to the second storage chamber 54 by the waste toner transport member 50.

  That is, when the image forming process is performed, the unused toner is consumed from the first storage chamber 47 while the waste toner is accumulated in the second storage chamber 54. As unused toner is consumed, the proportion of unused toner in the first storage chamber 47 decreases, and the empty space ratio in the first storage chamber 47 increases. Conversely, when the image forming process is performed, the ratio of the waste toner in the second storage chamber 54 increases, and the empty space ratio in the second storage chamber 54 decreases.

  In FIG. 2, the state before the movement (deformation) of the partition member 52 is shown. In this state, the partition member 52 is disposed along the inner wall surface of the toner cartridge 500. Accordingly, since the volume of the first storage chamber 47 is large, the storage amount of unused toner stored in the first storage chamber 47 can be increased.

  Thereafter, unused toner in the first storage chamber 47 is consumed, and the amount of waste toner stored in the second storage chamber 54 is increased, and the waste toner is gradually stored to the full capacity of the second storage chamber 54 initially. Ru.

  Furthermore, when the waste toner is stored in the second storage chamber 54, the unused toner in the first storage chamber 47 is consumed, so the weight of the waste toner stored in the second storage chamber 54 is used. The partition member 52 moves (deforms) toward the first storage chamber 47, and the volume of the second storage chamber 54 gradually increases. The partition member 52 is assumed to be movable (deformable) up to the dotted line in FIG.

  In other words, by the movement of the partition member 52, the volume of the second storage chamber 54 for storing the waste toner is variable. The waste toner storable space volume in the second housing chamber 54 is increased by the variable volume of the variable housing chamber 55 changed with the movement of the partition member 52, in addition to the space volume originally provided.

  In addition, if the partition member 52 is a member which can make the volume of the 2nd storage chamber 54 variable, various structures are widely applicable. For example, it may move in a sliding manner, or, for example, the second storage chamber 54 is in the form of a bag, and the volume of the second storage chamber 54 is expanded as the amount of waste toner increases. It may be something.

  In FIG. 2, a waste toner conveying member 51 for moving waste toner in the second storage chamber 54 is provided in the second storage chamber 54.

  Further, a toner hopper 59 is installed below the first storage chamber 47 for storing unused toner. Between the first storage chamber 47 and the toner hopper 59, a supply port 58 for supplying unused toner to the developing device is provided. The toner hopper 59 temporarily stores the unused toner supplied from the supply port 58.

  FIG. 3 is an explanatory view for explaining a waste toner conveyance structure in the image forming unit 10 according to the embodiment.

  The cleaning member 25 shown in FIG. 2 scrapes off the waste toner left on the surface of the photosensitive drum 19. As shown in FIG. 3, the waste toner conveying member 50 is formed of, for example, a helical structure, and when the driving force is applied to the waste toner conveying member 50 from, for example, a conveyance drive unit, the waste toner conveying member 50 is rotated. The waste toner is transported in the direction of arrow A1 in FIG.

  When the waste toner having moved in the direction of the arrow A1 reaches the vicinity of the end of the image forming unit 10, the waste toner is delivered to the waste toner conveying member 51.

  Here, the waste toner conveyance member 51 is formed of, for example, a helical structure, and the end portion thereof is structured such that a driving force is applied from a conveyance drive unit or the like. Further, as shown in FIG. 3, the waste toner conveying member 51 has a member 51 a provided in the second storage chamber 54 and a member 51 b extending near the end of the waste toner conveying member 50. ing. That is, the waste toner delivered from the waste toner transport member 50 is transported by the member 51b in the direction of the arrow A2, and further transported by the member 51a in the direction of the arrow A3 and transported to the back of the second storage chamber.

  FIG. 4 is a block diagram showing a configuration of a control system of the image forming apparatus 100 according to the embodiment.

  In FIG. 4, the configuration of the control system of the image forming apparatus 100 is the print control unit 27, the image data conversion unit 28, the drum rotation number measurement unit 29, the head light emission number measurement unit 30, the print data monitoring unit 31, the power supply for transfer roller 32, a charging roller power supply 33, a developing roller power supply 34, a supply roller power supply 35, a head drive control unit 36, a discharge light source power supply 37, a fixing control unit 38, a conveyance motor control unit 39, a drive motor control unit 40 , A cutter operation control unit 41, a calculation unit 42, a life display unit 57, and a temperature and humidity sensor 60.

  The print control unit 27 is a processing unit or a device that controls various processes related to print processing in the image forming apparatus 100. The hardware of the print control unit 27 includes a CPU, a ROM, a RAM, an EEPROM, an input / output interface unit, and the like. The CPU can be realized in the image forming apparatus 100 by executing a processing program stored in the ROM. Various processing is performed.

  The image data conversion unit 28 converts, for example, image data acquired from an external device such as a personal computer into head light emission command data for the exposure head 21. The head light emission command data is given to the head drive control unit 36 by the control of the print control unit 27.

  The drum rotation number measurement unit 29 measures the rotation number of the photosensitive drum 19. The drum rotation number measurement unit 29 counts, for example, the rotational distance length of the photosensitive drum 19 corresponding to the movement distance length in the sub-scanning direction of one page or several pages of the printing medium as one unit (that is, "1"). For example, one rotation of the cylindrical photosensitive drum 19 may be counted.

  The head light emission number measurement unit 30 counts the number of light emission of the light emitting elements constituting the exposure head 21 with respect to the image data.

  The print data monitoring unit 31 monitors the change of pages of the print data.

  The transfer roller power supply 32 is a power supply unit that applies a predetermined voltage to the primary transfer roller 15 and the secondary transfer roller 16.

  The charging roller power supply 33 is a power supply unit that applies a predetermined voltage to the charging roller 20 in order to uniformly charge the surface of the photosensitive drum 19.

  The developing roller power source 34 is a power source unit that applies a predetermined voltage to the developing roller 22 in order to develop on the surface of the photosensitive drum 19.

  The supply roller power supply 35 is a power supply unit that applies a predetermined voltage to the supply roller 23 and the development blade 24 in order to supply the unused toner stored in the first storage chamber 47 to the development roller 22.

  In order to expose the surface of the photosensitive drum 19 to light, the head drive control unit 36 acquires head light emission command data from the print control unit 27 and drives the light emission of the exposure head 21.

  The static elimination light emitting unit power source 37 is a power source unit that applies a predetermined voltage to the static elimination light radiation unit 26 in order to emit light from the static elimination light radiation unit 26.

  The fixing control unit 38 controls the operation of the heating roller 17 and the pressure roller 18 in order to fix the developer image borne on the roll paper P, which is a printing medium.

  The transport motor control unit 39 controls the operation of the roll paper feeder 11 in order to transport the roll paper P.

  The drive motor control unit 40 controls rotational driving of the intermediate transfer belt 14, the secondary transfer roller 16, and the photosensitive drum 19.

  The cutter operation control unit 41 controls the operation of the cutter 13 in order to cut one page of the roll paper P.

  The calculation unit 42 is an arithmetic processing unit that obtains a waste toner accommodation space ratio (that is, an empty space ratio of the second accommodation chamber 54) that can be accommodated in the second accommodation chamber 54 of the toner cartridge 500. The method of calculating the waste toner storable space rate by the calculation unit 42 will be described in detail in the section of operation.

  The life display unit 57 is a display unit that displays the remaining amount of the space capable of containing the waste toner, the life of the waste toner full state, and the like based on the calculation result by the calculation unit 42.

  For example, the life display unit 57 displays a screen including the life and the like on the operation display unit of the image forming apparatus 100. In this embodiment, the case where the life display unit 57 displays the waste toner full state or displays the waste toner accommodation possible space ratio is illustrated. The life display unit 57 may display a screen including the waste toner accommodation space ratio each time printing is performed, or when the waste toner accommodation space ratio exceeds a threshold, the waste toner accommodation space A screen including a rate may be displayed.

  The temperature and humidity sensor 60 is a sensor that measures temperature and humidity in order to recognize the environment in which the image forming unit 10 is placed.

(A-2) Operation of Embodiment Next, the processing operation of the image forming apparatus 100 according to the embodiment will be described in detail with reference to the drawings.

(A-2-1) Operation of Printing Process First, the operation of the printing process in the image forming apparatus 100 according to the embodiment will be described with reference to FIG. 1, FIG. 2, and FIG. 3.

  Image data is supplied from an external device such as a personal computer to the print control unit 27 of the image forming apparatus 100, and the print control unit 27 starts the printing process.

  The print control unit 27 drives the photosensitive drum 19 via the drive motor control unit 40, and rotates the photosensitive drum 19 at a predetermined peripheral speed in the direction of the arrow in FIG. The driving force by the driving motor control unit 40 is transmitted, for example, from the photosensitive drum 19 to the developing roller 22, the supply roller 23, the waste toner conveying member 50, and the waste toner conveying member 51 by a gear train. Each of the developing roller 22 and the supply roller 23 rotates in the direction of the arrow in FIG. The waste toner conveying member 50 and the waste toner conveying member 51 respectively convey waste toner generated in the process described later in the direction of arrow A1 → A2 → A3 in FIG.

  The charging roller 20 is not connected to these gear trains, and rotates in the direction of the arrow in FIG. 2 around the rotation of the photosensitive drum 19. At this time, a DC voltage is applied from the charging roller power source 33 to the charging roller 20 provided in contact with or in pressure contact with the surface of the photosensitive drum 19, and the surface of the photosensitive drum 19 is uniformly or uniformly charged. Ru. For example, in this embodiment, the aluminum tube of the photosensitive drum 19 is grounded, and by applying a DC voltage of -1000 V to the charging roller 20, the surface of the photosensitive drum 19 is charged to about -500 V.

  Next, in the exposure process, light corresponding to the head emission command data is irradiated from the exposure head 21 onto the charged surface of the photosensitive drum 19, and an electrostatic latent image is formed on the photosensitive drum 19. For example, in this embodiment, the potential on the photosensitive drum 19 of the exposed portion is about -50V.

  Furthermore, the electrostatic latent image on the photosensitive drum 19 is developed with toner by the operation of the developing device described in detail later, and a toner image is formed on the photosensitive drum 19. For example, in this embodiment, a DC voltage of −200 V is applied to the developing roller 22 from the power source 34 for developing roller. Further, the potential of the toner layer on the thinned developing roller 22 is about -50V.

  Since the sum of the potential of the thin toner layer and the voltage applied to the developing roller 22 exceeds the potential of the exposed portion on the photosensitive drum 19, the exposed portion on the photosensitive drum 19 is developed with toner. Since the sum of the potential of the thin toner layer and the voltage applied to the developing roller 22 does not exceed the potential of the unexposed portion of the photosensitive drum 19, the unexposed portion on the photosensitive drum 19 is not developed with toner.

  Further, the intermediate transfer belt 14 is rotated in the direction of the arrow in FIG. 1 by the drive motor control unit 40.

  For example, a DC voltage of +1000 V is applied to the primary transfer roller 15 provided opposite to the photosensitive drum 19 from the power supply 32 for transfer roller. The toner image formed on the photosensitive drum 19 is primary formed on the intermediate transfer belt 14 by the electric field generated between the primary transfer roller 15 (+1000 V) and the raw tube (grounded) of the photosensitive drum 19. Transcribed. After passing through the white image forming unit 10W located at the most downstream position by the rotation of the intermediate transfer belt 14, toner images of five colors of Y, M, C, K, and W at maximum are formed on the intermediate transfer belt 14. Be superimposed.

  On the other hand, the roll paper P is fed to the secondary transfer portion, that is, between the intermediate transfer belt 14 and the secondary transfer roller 16 by the drive of the roll paper feeder 11 connected to the transport motor control unit 39. At this time, the secondary transfer roller 16 is in contact with the intermediate transfer belt 14. Also, the backup roller 45 is grounded. A DC voltage +2000 V is applied to the secondary transfer roller 16 provided opposite to the backup roller 45 by the power supply 32 for transfer roller. The toner image formed on the intermediate transfer belt 14 is transferred to the roll paper P by the electric field generated between the secondary transfer roller 16 (+2000 V) and the backup roller 45 (grounded).

  Thereafter, the roll paper P further passes between the heating roller 17 and the pressure roller 18 constituting the fixing device, and the toner on the roll paper P is melted and penetrates between the fibers of the roll paper P by heat and pressure. Fixing of the toner image on the roll paper P is performed. The roll paper P on which the toner image is fixed is taken up by the rewinder 12.

  The print data monitoring unit 31 recognizes the turn of the page by detecting that the light emission of the exposure head 21 has ended according to the head light emission command data converted by the image data conversion unit 28. After that, the cutter 13 is operated by the cutter operation control unit 41, and the roll paper P is cut at a place behind the printing end place of the roll paper P by the margin.

  In addition, a slight amount of toner may remain on the photosensitive drum 19 after the primary transfer. The residual toner on the surface of the photosensitive drum 19 after transfer (hereinafter also referred to as “transfer residual toner”) is removed by the cleaning member 25. Here, part of the transfer residual toner and the external additive may slip through the cleaning member 25 and may be wound around the charging roller 20. However, these waste toners are removed by the charge cleaning roller 56.

  Furthermore, the static elimination light emitting unit 26 emits light and is irradiated to the photosensitive drum 19. Thereby, the unexposed charge on the photosensitive drum 19 is removed. The surface of the photosensitive drum 19 from which the charge has been removed is again charged by the charging roller 20. Thus, the photosensitive drum 19 is repeatedly used for image formation.

  Furthermore, some amount of toner may remain on the intermediate transfer belt 14 after the secondary transfer. However, the residual toner on the intermediate transfer belt 14 is removed by the belt cleaning member 43. The toner removed by the belt cleaning member 43 is transported by a waste toner transport member (not shown), for example, by a spiral or a paddle, and collected in the waste toner storage unit 44. Thus, the intermediate transfer belt 14 is repeatedly used for image formation.

  When the toner image primarily transferred from the image forming unit upstream of each image forming unit 10 passes the photosensitive drum 19 of the image forming unit other than the image forming unit 10 Y at the most upstream position, an intermediate transfer is performed. There is a phenomenon of so-called reverse transfer in which a part of the toner image is transferred from the belt 14 onto the surface of the photosensitive drum 19.

  That is, in the reverse transfer, the photosensitive drum 19 of the image forming unit 10 located downstream transfers a part of the toner image formed by the image forming unit 10 on the upstream side formed on the intermediate transfer belt 14 . The toner images of different colors are stacked on the intermediate transfer belt 14, but it is not limited that only a part of the stacked top toner images is reversely transferred to the surface of the photosensitive drum 19, and other than the top. A part of the toner image may also be reversely transferred to the surface of the photosensitive drum 19. Therefore, the image forming unit 10 located at the most downstream position is strongly affected by the reverse transfer.

  For example, in FIG. 1, in the case of the image forming unit 10C, when the toner images of the upstream toner colors Y and M pass the photosensitive drum 19C of the image forming unit 10C, part of the toner in the toner image is reversed. The image is taken and moved to the photosensitive drum 19C. The toner reversely transferred in this manner is removed from the surface of the photosensitive drum 19 by the cleaning member 25 by the rotation of the photosensitive drum 19, as with the transfer residual toner.

  Next, the operation in the printing process of the developing device will be described.

  As described above, the developing roller 22 and the supply roller 23 obtain the rotational driving force of the photosensitive drum 19 and rotate in the direction of the arrow in FIG.

  The toner stored in the toner hopper 59 is sent to the developing roller 22 by the rotation of the supply roller 23. The supply roller 23 and the developing roller 22 rotate in opposite directions at their contact portions, and thus negatively charge the toner by friction.

  When the toner fed to the developing roller 22 passes through the contact portion with the developing blade 24 by the rotation of the developing roller 22, the toner is frictionally charged by the developing roller 22 and the developing blade 24 and thinned. For example, in this embodiment, a DC voltage of -300 V is applied to the supply roller 23 and the developing blade 24 from the supply roller power supply 35.

  Thereafter, the toner on the thinned developing roller 22 is developed corresponding to the electrostatic latent image formed on the photosensitive drum 19, and the electrostatic latent image is developed with a developer image (toner image). Become.

(A-2-2) Concept of Calculation Processing of Waste Toner Containing Rate In the following, first, the concept of the calculation processing of the waste toner storing ratio by the calculating unit 42 will be described with reference to FIGS.

  FIG. 17 is an explanatory diagram for explaining the concept of the calculation process of the waste toner accommodation rate by the calculation unit 42 according to the embodiment.

  In FIG. 17, the calculation unit 42 calculates the amount of developer transferred from the developing device to the surface of the photosensitive drum 19 before transfer and the amount of developer remaining on the surface of the photosensitive drum 19 after transfer. Based on the above, the waste toner storage rate is determined.

  In addition, the calculation unit 42 obtains a variable accommodation volume of the waste toner accommodating space volume which is a denominator of the waste toner accommodation rate based on the developer amount transferred from the developing device before transfer to the surface of the photosensitive drum 19. .

  In FIG. 17, the developer amount Wt1 transferred from the developing device to the surface of the photosensitive drum 19 before transfer corresponds to the volume Wb of unused toner consumption described later in (A-2-3). The Wb corresponding to the volume of the unused toner consumption is the amount of toner consumed for development carried on the surface of the photosensitive drum 19 by the dot emission of the exposure head 21 before transfer, and the amount of toner on the surface of the photosensitive drum 19 Corresponds to the total amount Wt1 of the amount of toner carried as the drum fog. That is, the calculation unit 42 calculates, as the developer amount Wt1 before transfer, the volume expansion of the second storage chamber 54 for storing waste toner in the toner cartridge.

  Further, in FIG. 17, the developer amount Wt2 remaining on the surface of the photosensitive drum 19 after transfer corresponds to the waste toner volume W described later in (A-2-3). The waste toner volume W corresponds to the total amount of the transfer residual toner amount, the fog transfer residual toner amount, and the reverse transfer toner amount Wt2. That is, the calculation unit 42 calculates the amount of waste toner (waste toner volume) that occupies the storage space of the second storage chamber 42 in the toner cartridge.

  Here, the amount of toner after transfer of the drum fog will be described with reference to FIG.

  In FIG. 18, the drum fog toner is generated when the photosensitive drum 19 rotates. During the developing operation (that is, at the time of dot light emission printing), drum fog occurs simultaneously on the surface of the photosensitive drum 19. The toner amount of this drum fog is described as "W (fog)" in FIG.

  The toner of the drum fog generated on the surface of the photosensitive drum 19 is transferred to the intermediate transfer belt 14. The amount of drum fog toner transferred by the intermediate transfer belt 14 is described as "W (fog transfer)" in FIG.

  On the other hand, among the toner W (fogging) of the drum fog, a toner remaining on the surface of the photosensitive drum 19 without being transferred may also occur. The toner remaining on the surface of the photosensitive drum 19 without being transferred is treated as a transfer residual toner of fog. The transfer residual toner amount of this fog is described as "W (fog transfer remaining)" in FIG.

  In this embodiment, the transfer residual toner amount W of fog (fog transfer residual) in FIG. 18 is calculated by the transfer residual toner amount of fog W (fog transfer residual) = transfer residual efficiency of fog (Q) × W (fog) .

  Next, the amount of transfer residual toner will be described with reference to FIG.

  In FIG. 19, toner used for development is transferred onto the surface of photosensitive drum 19. The amount of toner used for this development is described as "W (development)" in FIG.

  The toner used for development transferred onto the surface of the photosensitive drum 19 is transferred to the intermediate transfer belt 14. The amount of drum fog toner transferred by the intermediate transfer belt 14 is described as "W (transfer)" in FIG.

  On the other hand, among the toner W (transfer) used for development, toner remaining on the surface of the photosensitive drum 19 without being transferred may also occur. The toner remaining on the surface of the photosensitive drum 19 without being transferred is treated as a transfer residual toner. This transfer residual toner amount is described as "W (transfer remaining)" in FIG.

  In this embodiment, the transfer residual toner amount W (transfer residual) in FIG. 19 is calculated by the transfer residual toner amount W (transfer residual) = transfer residual efficiency (J) × W (development).

  Further, the amount of reverse transfer toner will be described with reference to FIG. In FIG. 20, the amount of reverse transfer toner on the photosensitive drum 19C of the image forming unit 10C using the developer of cyan (C) in FIG. 1 will be described as an example.

  Image forming units 10Y and 10M are located upstream of the image forming unit 10C.

  In FIG. 20, the amount of toner used for development of the photosensitive drum 19Y is described as "W (development Y)", and the amount of toner used for development of the photosensitive drum 19M is described as "W (development M)" There is.

  The toner used for developing the photosensitive drums 19Y and 19M is transferred to the intermediate transfer belt 14 and conveyed to the photosensitive drum 19C.

  At the position of the photosensitive drum 19, some of the toner Y and the toner M, which are transported by the intermediate transfer belt 14 and used for development, can be reversely transferred onto the surface of the photosensitive drum 19C. The amount of reverse transfer toner reversely transferred to the surface of the downstream photosensitive drum 19C is denoted as "W (reverse transfer C)" in FIG.

  In this embodiment, the reverse transfer toner amount W (reverse transfer C) in FIG. 20 is the reverse transfer toner amount W (reverse transfer C) = {reverse transfer residual efficiency RY (reverse transfer efficiency of toner Y) × W (development Y ) + {Reverse transfer residual efficiency RM (reverse transfer efficiency of toner M) × W (development M).

(A-2-3) Arithmetic Processing of Waste Toner Containable Space Rate Next, how to consume unused toner in the first containing chamber 47 in the toner cartridge and for accumulation of waste toner in the second containing chamber 54 After describing the method, a method of calculating the waste toner accommodating space rate will be described.

  5, 6, and 7 are explanatory diagrams for explaining the state of the accumulation of waste toner in the second accommodation chamber 54 of the embodiment.

  FIG. 5 shows an initial state of waste toner accumulation. As shown in FIG. 5, it is shown that unused toner is sufficiently contained in the first accommodation chamber 47 and waste toner is accumulated in the second accommodation chamber 54. In this case, since the unused toner is sufficiently stored in the first storage chamber 47, the partition member 52 is positioned on the inner wall side of the toner cartridge 500.

  FIG. 6 shows the middle stage of waste toner accumulation. Furthermore, the storage amount of waste toner is increased. In this case, as shown in FIG. 6, the unused toner in the first storage chamber 47 is consumed, and the empty space ratio of the first storage chamber 47 is high. On the other hand, the storage amount of waste toner in the second storage chamber 54 increases, and the weight of the waste toner moves the partition member 52 toward the first storage chamber 47 (moves in the arrow direction in FIG. 6) The space for storing waste toner is expanding.

  FIG. 7 shows the state of maximum waste toner accumulation (waste toner full). In this case, the partition member 52 is deformed to the deformation limit, and the volume of the second storage chamber 54 is also maximum. In addition, the waste toner in the second storage chamber 54 is also full.

The calculation unit 42 discards the waste toner based on the volume (volume) W_life of the waste toner accommodating space capable of accommodating the waste toner and the volume W of the waste toner occupying the volume of the waste toner accommodating space according to the equation (1). Calculate the toner storage rate.
Waste toner accommodation rate [%] = {Waste toner volume (W) / Waste toner acceptable space volume (W_life)} × 100 (1)

  Here, the problem is that the volume of the second accommodation chamber 54 for accommodating waste toner (that is, the volume of the space capable of containing waste toner) may change. That is, since the denominator of the waste toner accommodation rate (%) is variable, the waste toner accommodation rate can not be accurately calculated if the value of the waste toner accommodating space volume is fixed as in the prior art.

  Therefore, in this embodiment, the value of the waste toner storable space volume W_life is varied by the initial volume (fixed value) of the second accommodation chamber 54 and the movement (deformation) of the partition member 52 (variation value) The calculation unit 42 calculates the waste toner accommodation rate separately.

  Further, regarding the variable volume, the volume in which the calculation unit 42 is variable based on the consumption of unused toner consumed for development and the amount of waste toner remaining on the surface of the photosensitive drum 19 after transfer. Calculate

  A specific method of calculating the waste toner storage rate by the calculation unit 42 will be described below.

  FIG. 8 is an explanatory view for explaining a waste toner storable space volume (W_life) according to the embodiment.

  8 (a) shows the waste toner accumulation initial state (see FIG. 5), FIG. 8 (b) shows the waste toner accumulation middle state (see FIG. 6), and FIG. 8 (c) shows the waste toner maximum accumulation state (see FIG. 7) is shown in a simplified manner.

  The waste toner storable space volume (W_life) is a volume of a space capable of storing waste toner.

  First, in each of FIGS. 8A, 8B, and 8C, a method of calculating the waste toner storable space volume W_life will be described.

  Here, the initial volume of the second accommodation chamber 54 is Wa, and the volume of a space capable of accommodating waste toner in the variable accommodation chamber 55 by the movement (deformation) of the partition member 52 is Wb. The waste toner storable space volume Wb in the variable storage chamber 55 fluctuates in 0 ≦ Wb ≦ Wb_max. The value of Wb_max can be the volume of the variable storage chamber 55 when it is deformed to the deformation limit of the partition member 52, as shown in FIG. 8C.

  Although the life display unit 57 may display the life of the toner cartridge 500 when the waste toner accommodation rate reaches 100% (full state), the life display unit 57 displays the near-full state. You may In that case, a predetermined margin may be provided in the calculation of the waste toner accommodation rate. Specifically, for example, Wa and Wb_max may be set to a value or the like of 80% of the actual space volume capable of containing waste toner, and then the calculation unit 42 may calculate the waste toner accommodation rate.

In the state shown in FIG. 8A, the partition member 52 is in the vicinity of the inner wall of the toner cartridge 500, and unused toner is sufficiently accommodated in the first accommodation chamber 47. The waste toner is stored in the second storage chamber 54. Therefore, the calculation unit 42 can calculate W_life according to Equation (2).
W_life = Wa (2)

In the state of FIG. 8B, since the unused toner is consumed, the partition member 52 moves in the direction of the arrow of FIG. 8B. Therefore, the calculation unit 42 can calculate W_life according to Equation (3).
W_life = Wa + Wb (3)

  In equation (3), Wb can be considered to be equal to the amount of unused toner consumed. The method of obtaining this Wb will be described later.

In the state of FIG. 8C, the unused toner is sufficiently consumed, and the partition member 52 is deformed to the movement limit. Therefore, the calculation unit 42 can calculate W_life according to Equation (4).
W_life = Wa + Wb_max (4)

  Now, as described above, in FIG. 8B, Wb is equal to the consumption of unused toner. Therefore, how to determine the consumption amount of unused toner will be described.

Wb corresponding to the unused toner consumption is the amount of toner consumed for development carried on the surface of the photosensitive drum 19 by the light emission of the dots of the exposure head 21 before transfer (consumption of the dot light emission by development), It is represented by the sum of the amount of toner carried as drum fog on the surface of the photosensitive drum 19 (consumed amount by drum fog).
Wb = (consumption of development of dot emission + consumption of drum fog) × reference volume count (Vcnt) (5)

  The consumption amount by development of dot emission and the consumption amount by drum fog in the equation (5) are converted to a dot count unit as described later.

  Formula (5) is the volume of the amount of unused toner carried on the exposed portion of the surface of the photosensitive drum 19 from the start of printing to the calculation timing (consumption of dot light emission development × reference volume count), The unused toner consumption amount is calculated by adding the volume of the unused toner amount supported on the surface of the photosensitive drum 19 as the drum fog (consumed amount by drum fog × reference volume count) although it is the unexposed portion of 19 Is calculated.

The reference volume count is a value of toner volume per dot count which is a predetermined unit. The value of the reference volume count may be preset. The value of toner volume consumed per dot count (that is, reference volume count) may differ depending on the color of toner because specific gravity (g / mm ³ ) varies depending on the color of toner. Therefore, different reference volume counts may be set for each of the image forming units 10. Here, in order to facilitate the description, for example, the case where the reference volume count is “0.6” will be described as an example.

  Here, the dot count will be described. In the dot count, 3192 dots are counted as one dot when one light emission of one light emitting element of the exposure head 21 is regarded as one dot at the time of development. Here, in the printing area of the sheet, the number of light emission dots of the exposure head 21 of the image forming unit 10 is calculated in consideration of the average printing rate of the image forming unit 10.

  For example, when the lighting ratio (= printing ratio) of the dots of the exposure head 21 is 5% in the printing area excluding the 2 mm by 2 mm margins of A6 paper (105 mm × 148 mm), the number of light emission dots is “198 × 8192”. It is defined as "dots / piece (lighting rate 5%)". The value obtained by dividing the number of head emissions by 8192 (ie, 198) is referred to as "emission dot count". That is, the light emitting dot count can be obtained by dividing the number of head light emissions acquired from the head light emission number measurement unit 30 by the predetermined value (for example, 8192) by the calculation unit 42.

The consumption by development of the dot emission in Expression (5) is expressed in dot count units, and can be calculated by the calculation unit 42 according to Expression (6).
Consumption amount by development of dot emission = (198/5) × average printing rate [%] × value obtained by converting printing distance to the number of printed sheets of printing medium (6)

  The value obtained by converting the printing distance into the number of printing sheets of the printing medium is the printing distance length in consideration of the number of printing sheets. For example, in the case of A6 paper, a value obtained by multiplying the printing distance by the number of printing sheets can be applied.

  The consumed amount due to drum fog in the equation (5) means the amount of toner attached to the surface of the unexposed portion of the photosensitive drum 19 during development. The drum fog refers to, for example, a toner having a charge amount whose absolute value is lower than that of a normally negatively charged toner, or a toner charged to the opposite polarity and attached to an unexposed portion of the surface of the photosensitive drum 19.

  The amount of adhesion of the drum fog varies depending on the temperature and humidity environment and the color, but if these conditions are determined, the toner consumption due to the drum fog is proportional to the drum count, which is a value proportional to the number of rotations of the photosensitive drum 19 The present embodiment deals with this case.

The toner consumption amount due to drum fogging in the equation (5) is also expressed in dot count units and is as follows.
Consumption due to drum fog = coefficient D x drum count ... (7)

  Here, the drum count is a unit rotation number of the photosensitive drum 19 that contributes to printing on the print medium. For example, in this embodiment, when the photosensitive drum 19 is rotated by the printing distance (444 mm) of three sheets of A6 paper, one drum count is performed. The drum rotation number measurement unit 29 measures the rotation number of the photosensitive drum 19, and the calculation unit 42 recognizes the distance of one rotation of the photosensitive drum 19. Therefore, the calculation unit 42 can obtain the value of the drum count from the number of rotations of the photosensitive drum 19 acquired from the drum rotation number measurement unit 29.

  In equation (7), the coefficient D is a fog correction coefficient for calculating the drum fog. The coefficient D (fog correction coefficient) depends on the color of the toner and the temperature and humidity. In this embodiment, with regard to the coefficient D, the calculation unit 42 refers to the fog correction coefficient correspondence table to obtain corresponding values according to the environmental conditions of temperature and humidity.

  FIG. 9 is an explanatory diagram for explaining an example of an environmental region corresponding to temperature and humidity. Although FIG. 9 exemplifies the case of dividing into three areas according to the temperature and the humidity, the areas may be divided into two or four or more. Further, the values of temperature and humidity defining each environmental region are not limited to those defined in FIG.

  FIG. 10 is an explanatory diagram for explaining the fog correction coefficient correspondence table according to the embodiment. In FIG. 10, when the temperature and humidity belong to “area 1”, the coefficient D is large because the drum fog amount is larger as the temperature and humidity are higher. Conversely, when the temperature and humidity belong to “area 2” and “area 3”, the factor D is smaller because the drum fog amount is smaller as the temperature is lower and the humidity is lower.

  In the equation (7), from the temperature and humidity environment where the image forming unit 10 is located, the value substituted into the coefficient D corresponds to which of the region 1, region 2 and region 3 as an environmental region using FIG. 9 The environmental area and color information are obtained by comparing the table of FIG. 10 with the fog correction coefficient correspondence table.

The volume (W) occupied by waste toner in the equation (1) can be calculated by the following equation.
Waste toner volume (W) = transfer residual toner volume (Wtr) + fog transfer residual toner volume (Wk) + reverse transfer toner volume (Wr) (8)

The transfer residual toner volume (Wtr) is a volume of toner remaining on the surface of the photosensitive drum 19 after transfer. Therefore, the calculation unit 42 can calculate the transfer residual toner volume (Wtr) according to the equation (9).
Transfer residual toner volume (Wtr) = transfer residual efficiency (J) × emission dot count × reference volume count (Vcnt) (9)

  In the transfer residual toner volume (Wtr) of the equation (9), the light emission dot count value of the exposure head 21 is multiplied by the reference volume count (Vcnt) to obtain the possibility of toner remaining on the surface of the photosensitive drum 19 It shows that it obtains by multiplying the transfer residual efficiency (J) which is a ratio shown. In Expression (9), the transfer residual efficiency (J) can be set to an empirical value, and for example, in the embodiment, the transfer residual efficiency (J) is 3%. The value of the transfer residual efficiency (J) may be different depending on the toner color.

For the transfer residual toner volume (Wk) of fog in the equation (8), the same concept of efficiency as that for obtaining the transfer residual toner volume (Wtr) can be applied. The calculation unit 42 can calculate the transfer residual toner volume (Wk) of fog according to the equation (10).
Transfer residual toner volume of fog (Wk) = transfer residual efficiency of fog (Q) × fog correction coefficient (D) × drum count × reference volume count (Vcnt) (10)

  The transfer residual toner volume (Wk) of the fog in equation (10) is the consumption amount by drum fog (see equation (7)) multiplied by the reference volume count (Vcnt) to obtain the photosensitive drum 19 after drum fog is transferred. Obtained by multiplying the transfer residual efficiency (Q) of fog, which is a ratio indicating the possibility of remaining on the surface of In equation (10), the transfer residual efficiency (Q) of fog can be set to an empirical value. For example, in the embodiment, it is assumed that the transfer residual efficiency (Q) of fog is 3%. The value of the transfer residual efficiency (Q) of the fog may be different depending on the toner color, or a value corresponding to the environment of temperature and humidity may be used.

In (Expression 8), the reverse transfer toner volume (Wr) is reversed from the developer image on the intermediate transfer belt 14 formed by the image forming unit 10 located upstream to the photosensitive drum 19 of the image forming unit 10 It is the volume of the photographed toner. The calculation unit 42 can calculate the reverse transfer toner volume (Wr) according to the equation (11).
Reverse transfer toner volume (Wr) = Σ (reverse transfer efficiency (R) × unused toner consumption amount (Wb) × reference volume count (Vcnt)) (11)

  In equation (11), the reverse transfer toner volume (Wr) is the sum of reverse transfer toner volumes of all the upstream image forming units 10 excluding the image forming unit 10.

  The reverse transfer efficiency (R) indicates the ratio of the possibility of reverse transfer onto the surface of the photosensitive drum 19 of the image forming unit 10, and varies depending on, for example, the color of toner, temperature and humidity environment. Therefore, the calculation unit 42 uses FIG. 9 to determine which of the region 1, region 2 and region 3 the environment region corresponds to, and compares the environment region and color information with the reverse transfer efficiency correspondence table of FIG. Ask.

  For example, the case of calculating the reverse transfer toner volume (Wr) of the image forming unit 10C will be illustrated. In this case, the image forming unit 10Y and the image forming unit 10M are present upstream. Therefore, when the calculation unit 42 calculates the reverse transfer toner volume (Wr) of the image forming unit 10C, the calculation unit 42 calculates (reverse transfer efficiency (R) x unused toner consumption amount (Wb) x of the image forming unit 10Y). Reverse transfer toner is obtained by adding the value of reference volume count (Vcnt) and the value of (reverse transfer efficiency (R) × unused toner consumption amount (Wb) × reference volume count (Vcnt) of image forming unit 10M) Determine the volume (Wr).

  FIG. 12 is a flow chart showing the operation of the calculation process of the waste toner storable space ratio and the process of displaying the remaining amount and the life of the waste toner storage space in the image forming apparatus 100 according to the embodiment.

  The calculation unit 42 sets the waste toner accommodation rate and the waste toner for each image forming unit 10 each time printing processing for a predetermined distance (in this embodiment, for example, 740 mm (= A6 paper equivalent) is performed). Calculate the storable space rate.

  The calculation unit 42 calculates the waste toner storable space volume W_life and the volume (W) occupied by the waste toner for each image forming unit 10 each time printing processing is performed, and the latest waste toner accommodation ratio The waste toner accommodation space rate is updated for each image forming unit 10.

  In step S101, when the printing process is performed, the calculation process of the waste toner accommodation rate for each of the image forming units 10 is started.

  In step S102, the drum rotation number measurement unit 29 measures the drum count of the photosensitive drum 19 of each image forming unit 10, and supplies the measured drum count to the calculation unit 42.

  In step S103, the head light emission number measurement unit 30 measures the light emission dot count number of the exposure head 21 of each image forming unit 10, and supplies the light emission dot count to the calculation unit 42.

  In step S104, the calculation unit 42 uses the light emission dot count of each of the image forming units 10 to calculate the consumption amount by the development of the dot light emission for each of the image forming units 10 according to the equation (6). Further, the calculation unit 42 obtains the consumption amount due to the drum fog for each image forming unit 10 using the value of the drum count of each image forming unit 10 according to the equation (7). Then, the calculation unit 42 obtains the amount of unused toner (fresh toner amount) used for each of the image forming units 10 according to the equation (5).

  In step S105, the calculation unit 42 obtains the value of the waste toner storable space volume W_life for each of the image forming units 10.

  Here, in step S105, the calculation unit 42 compares the value of the waste toner storable space volume W_life immediately before the current printing process with the volume Wa of the second accommodation chamber 54.

  Then, when the value of the waste toner storable space volume W_life immediately before is equal to or less than the volume Wa of the second storage chamber 54 (when W_life ≦ Wa), the calculation unit 42 stores the waste toner storable space according to equation (2). Let the value of the volume W_life be Wa.

  In addition, when the value of the last waste toner accommodation space volume W_life reaches the value of Wa + Wb_max, the calculation unit 42 sets the value of the waste toner accommodation space volume W_life to Wa + Wb_max according to the equation (4).

  On the other hand, when the value of the last waste toner accommodation space volume W_life exceeds the volume Wa of the second accommodation chamber 54 (when W_life> Wa), the calculation unit 42 calculates the waste toner accommodation space according to the equation (3). Determine the value of the volume W_life.

  Here, in particular, the operation when the value of the immediately preceding waste toner accommodating space volume W_life exceeds the volume Wa of the second accommodation chamber 54 (when W_life> Wa) will be mainly described.

  In step S105, the calculation unit 42 determines the waste toner storable space volume W_life (= Wa + Wb) according to the equation (3), where Wb is the used unused toner amount (fresh toner amount). Here, the value of the waste toner storable space volume W_life is A.

  In step S106, the calculation unit 42 obtains the volume (W) occupied by the waste toner for each of the image forming units 10. That is, using the value of the light emission dot count of each of the image forming units 10 acquired from the head light emission number measurement unit 30, the calculation unit 42 obtains the transfer residual toner amount (Wtr) according to equation (9). Further, the calculation unit 42 obtains the transfer residual toner volume (Wk) of fog according to the equation (10) using the value of the drum count of each image forming unit 10 acquired from the drum rotation number measurement unit 29. Furthermore, the calculation unit 42 uses the reverse transfer efficiency (R), unused toner consumption (Wb), and reference volume count (Vcnt) of all the image forming units 10 located upstream for each image forming unit 10. The reverse transfer toner volume (Wr) is determined for each of the image forming units 10. Then, the calculation unit 42 adds the transfer residual toner amount (Wtr), the transfer residual toner volume (Wk) of fog, and the reverse transfer toner volume (Wr) according to the equation (8), and discards each image forming unit 10. The volume occupied by the toner (W) is determined. Here, the value of the volume (W) occupied by the waste toner is B.

  In step S107, the calculation unit 42 obtains the waste toner accommodation rate (%) according to the equation (1) using the toner storable amount A calculated in step S105 and the volume B occupied by the waste toner. Here, the value of the waste toner storage rate is C.

In step S108, the calculation unit 42 obtains the waste toner storable space ratio D from the toner storage ratio C calculated in step S107 according to the equation (12).
Waste toner accommodation space ratio [%] = 100-waste toner accommodation ratio [%] (12)

  In step S109, the calculation unit 42 determines whether the waste toner storable space ratio is 0 [%]. Then, when the waste toner accommodation space rate is 0 [%] (in the case of “Y” in step S109), the process proceeds to S110, and the life display unit 57 displays the life of the image forming unit 10 due to waste toner full. A display is performed (S110), and the process ends in step S112. In this case, the image forming apparatus 100 stops the operation of the image forming process in order to urge replacement of the toner cartridge in the image forming unit 10.

  On the other hand, when the waste toner accommodation space rate is not 0% in step S109 (in the case of "N" in step S109), the process proceeds to S111, and the life display unit 57 displays the display screen including the waste toner accommodation space rate. In step S111, the process ends in step S112.

  Next, in order to confirm the effect of this embodiment, an example using the image forming apparatus 100 will be described in comparison with two comparative examples.

  FIG. 13 is an explanatory view for explaining conditions of an example using the image forming apparatus 100 according to the embodiment and a comparative example.

  In the example and the two comparative examples, printing was performed under the following conditions, and evaluated by the following evaluation methods.

  Under an environment of 27 ° C. and 80% RH (corresponding to “region 1” in FIG. 9), as shown in FIG. 13, the average print of the image forming unit 10W (denoted as “W” in FIG. 13). The average printing rate of image forming units 10Y, 10M, 10C and 10K (indicated as "YMCK" in FIG. 13) with a rate of 2% is 15% or 60% while continuous printing is performed. It was verified how the waste toner accommodation space ratio of the image forming unit 10W, which is the most downstream position, is displayed on the life display unit 57.

  In the embodiment, the waste toner storable space volume W_life is a case where the portion of Wb changes according to the consumption condition of the unused toner as expressed by the equation (3).

  On the other hand, in the comparative example 1, the value of the waste toner storable space volume W_life is set to Wa as the minimum fixed value (see equation (2)).

  In Comparative Example 2, the value of the waste toner storable space volume W_life was set to Wa + Wb_max as the maximum fixed value (see Formula (3)).

  FIG. 14 is an explanatory view for explaining the evaluation result of the waste toner storable space ratio of the most downstream image forming unit 10W according to the embodiment. FIG. 14A shows the case where the average printing rate of YMCK is 15%. FIG. 14B shows the case where the average printing rate of YMCK is 60%.

  14 (a) and 14 (b), the horizontal axis represents the number of printed sheets equivalent to A6 (the printing distance is converted to the number of A6 sheets), and the vertical axis is displayed on the life display section 57. The waste toner accommodation space ratio of the image forming unit 10W on the most downstream side is shown.

  As shown in FIG. 14A, in the case where the average printing rate of YMCK is 15%, Comparative Example 1 performs the continuous printing of about 9900 A6 sheets, and the waste toner accommodation space ratio is higher than the actual one. It is calculated to be low, and the life display unit 57 displays the waste toner full, and thereafter, the image forming unit 10W can not be used. However, as in the example, the waste toner accommodation space ratio is about 30%, and in fact there is a space where the waste toner can be accommodated. That is, in the case of Comparative Example 1, since the waste toner accommodating space volume is set to the minimum fixed value, a disadvantage occurs in that the life display comes out earlier than the actual waste toner accommodation capacity.

  As shown in FIG. 14B, when the average printing rate of Y, M, C, and K is 60%, according to the embodiment, when continuous printing equivalent to 3,000 A6 sheets is performed, the lifetime display unit 57 performs waste toner full display. At this time, when the actual storage state of the second storage chamber 54 was confirmed, as shown in FIG. 15, the storage possible state of the waste toner was full. On the other hand, in the case of Comparative Example 2, the value of the waste toner storable space volume is set to Wa + Wb_max (maximum fixed value). Therefore, in the case of Comparative Example 2, the waste toner accommodation space ratio is calculated higher than the actual value even when continuous printing of about A6 paper 3500 sheets is performed, and the waste toner full display is not displayed, which may cause a problem. .

  As described above, in the method in which the value of the waste toner accommodating space volume is fixed, there is a disadvantage that the waste toner full display is output earlier or later.

  On the other hand, in the case of the embodiment, the waste toner storable space volume and the waste toner calculated by the calculation unit 42 are calculated by varying the waste toner storable space volume according to the consumption amount of unused toner. Deviation from the storable space volume can be reduced.

(A-3) Effects of the Embodiment As described above, according to the embodiment, the partition member 52 between the unused toner and the waste toner expands the waste toner storage space depending on the consumption of the unused toner. In the moving configuration, the calculation unit 42 calculates the consumption amount of unused toner from the number of light emissions of the exposure head 21 and the number of rotations of the photosensitive drum 19. In addition, the calculation unit 42 obtains the volume of the waste toner storage space at that time assuming that the waste toner storage space using unused toner is expanded. Furthermore, the calculation unit 42 calculates the amount of waste toner from the number of light emissions of the exposure head 21 and the number of rotations of the photosensitive drum 19, and obtains the volume occupied by the waste toner at that time. Then, the calculation unit 42 obtains the waste toner accommodation rate based on the waste toner storable space volume and the volume occupied by the waste toner. In addition, the calculation unit performs the calculation of the waste toner storage rate for each predetermined number of prints (for example, five A6 sheets).

  As a result, it is possible to calculate an accurate waste toner accommodation rate in real time, and although the waste toner can be accommodated, the waste toner full display appears and the waste toner full display does not actually appear although the waste toner full display actually occurs. It is possible to avoid a situation where the image forming unit can not be used.

(B) Other Embodiments In the above-described embodiment, various modified embodiments are mentioned, but the present invention can be applied to the following modified embodiments.

  (B-1) In the above embodiment, the case where the calculation result of the waste toner accommodation space ratio is displayed as it is on the life display unit 57 is exemplified.

  However, the average printing rate of the image forming unit differs depending on the color etc. of the image data used for printing. Depending on the use condition of toner, the waste toner capacity may increase. In this case, the life display unit 57 may display the value of the waste toner storable space ratio to be displayed so as to decrease monotonously.

  That is, comparing the previous calculation result of the waste toner accommodation space rate with the calculation result of the present waste toner accommodation space rate, if the present waste toner accommodation space rate is higher than the previous value, the life display For example, the unit 57 hides the screen including the current value obtained by the calculation unit 42, or displays the screen including the value of the waste toner storable space ratio immediately before. good. In other words, when the value of the calculation result of the waste toner capacity ratio increases, the life display unit 57 displays the display value of the life display unit 57 immediately before as it is.

  For example, under an environment of 27 ° C. and 80% RH (corresponding to “Area 1” in FIG. 9), until printing equivalent to 6000 sheets of A6 paper, the average printing rate of the image forming unit 10W is 2%, and the image forming unit 10Y, The average printing rate of 10M, 10C and 10K is set to 15%. For example, the image forming unit 10W is printed at an average printing rate of 20% and an image forming unit 10Y, 10M, 10C, 10K at an average printing rate of 5% after 6000 sheets, and the image forming unit at the most downstream position. How the 10 W waste toner empty space is displayed on the life display unit 57 will be described in the first embodiment and the present example (described as the second embodiment).

  FIG. 16 is an explanatory view for explaining evaluation results of Example 2 and Example 1 using the image forming apparatus of the modified embodiment. The horizontal axis represents the A6 equivalent number of printed sheets (the print distance converted to the number of A6 sheets), and the vertical axis represents the waste toner capacity of the most downstream image forming unit 10W displayed on the life display unit 57. .

  In FIG. 16, for example, the amount of reverse transfer toner from the image forming unit 10 located upstream with respect to the speed of increase of the waste toner accommodation space ratio due to the toner consumption of the image forming unit 10W increasing after 6000 sheets. Will be reduced.

  For this reason, in the case of the first embodiment, the value of the waste toner accommodation space ratio is higher than 50%, which is the value of the waste toner accommodation space ratio at the time of 6000 sheets, from about 6000 sheets to about 9000 sheets. Is displayed.

  On the other hand, in the case of the second embodiment, when the waste toner accommodating space ratio is increasing, the value of the waste toner accommodating space just before is displayed. Therefore, even if the actual calculation of the waste toner accommodation space ratio increases after 6000 sheets, the value of the waste toner accommodation space ratio is 50% at the time of printing 6000 sheets. Furthermore, since the value of the waste toner storable space ratio calculated after 9,000 sheets is smaller than 50% at the time of printing 6,000 sheets, the life display section 57 can display a value smaller than 50%.

  (B-2) In the embodiment described above, the case where the present invention is applied to a color image forming apparatus in which roll paper is used as a print medium and an intermediate transfer method is adopted has been exemplified. However, the present invention is not limited to the color image forming apparatus described above, and, for example, a copier, a LED printer, a laser beam printer, a facsimile, an MFP, etc. It is applicable to the used image forming apparatus.

  100 ... image forming apparatus, 10 (10Y, 10M, 10C, 10K, 10W) ... image forming unit, 14 ... intermediate transfer belt, 15 (15Y, 15M, 15C, 10K, 10W) ... primary transfer roller, 16 ... 2 Next transfer roller, 500: toner cartridge, 47: first storage chamber, 54: second storage chamber, 52: partition member, 27: print control unit, 28: image data conversion unit, 29: drum rotation number measurement unit , 30: head light emission number measurement unit, 31: print data monitoring unit, 32: power supply for transfer roller, 33: power supply for charging roller, 34: power supply for development roller, 35: power supply for supply roller, 36: head drive control unit 37: power source for static elimination light 38: fixing control unit 39: conveyance motor control unit 40: drive motor control unit 41: cutter control unit 42: calculation unit 57: life display unit 60 Temperature and humidity sensor.

Claims (7)

A first storage chamber for storing unused developer;
A second storage chamber for storing waste developer;
Partitioning a space between said second storage chamber and said first storage chamber, and a partition member that operates the space volume of the second storage chamber to expand large to so that,
A latent image carrier,
A developing unit that develops by moving the unused developer in the first accommodating chamber to the latent image on the latent image carrier,
A waste developer collecting means for collecting the waste developer remaining on said image bearing member after the transfer to the second housing chamber,
The waste developer storage rate in the second storage chamber is determined based on the volume of the waste developer storageable space of the second storage chamber and the volume of the waste developer stored in the second storage chamber. Calculation means ,
And display means for displaying the storage state of the waste developer in the second storage chamber ,
It said calculating means, based on the amount of developer is moved from the developing unit before transfer to the latent image carrier to obtain the expansion volume of the waste developer can accommodate the spatial volume of the second storage chamber,
The display means is
The waste developer storable space ratio in the second storage chamber is compared with the threshold value based on the waste developer content obtained by the calculation means, and the waste developer storable space percentage is less than the threshold value. Displaying a screen including the waste developer accommodating space rate,
When the value of the current waste developer storable space ratio obtained by the calculation means is larger than the value of the previous waste developer storable space ratio, the current waste developer storable space percentage is included. An image forming apparatus characterized by hiding a screen . A first storage chamber for storing unused developer;
A second storage chamber for storing waste developer;
A partition member operable to partition a space between the first storage chamber and the second storage chamber and to expand a space volume of the second storage chamber;
A latent image carrier,
Developing means for moving the unused developer in the first storage chamber to the latent image on the latent image carrier for development;
Waste developer recovery means for recovering waste developer remaining on the latent image carrier after transfer to the second storage chamber;
The waste developer storage rate in the second storage chamber is determined based on the volume of the waste developer storageable space of the second storage chamber and the volume of the waste developer stored in the second storage chamber. Calculation means,
And display means for displaying the storage condition of the waste developer in the second storage chamber
Equipped with
The calculation means determines an enlarged volume of the waste developer storable space volume of the second storage chamber based on the amount of developer moved from the developing means before transfer to the latent image carrier.
The display means is
The waste developer storable space ratio in the second storage chamber is compared with the threshold value based on the waste developer content obtained by the calculation means, and the waste developer storable space percentage is less than the threshold value. Displaying a screen including the waste developer accommodating space rate,
When the value of the current waste developer storable space ratio obtained by the calculation means is larger than the value of the previous waste developer storable space ratio, the previous value including the waste developer storable space ratio is included. images forming apparatus you and displaying the screen. Claims wherein the calculation means, based on the amount of the developer remaining on the latent image bearing member after transfer, and obtains the volume of the waste developer showing the spatial volume of the second containing chamber The image forming apparatus according to 1 or 2 . First measuring means for measuring the number of rotations of the latent image carrier;
An exposure member for exposing the latent image bearing member above,
A second measuring unit that measures the exposure amount of the exposure member;
The calculation means uses the number of rotations of the latent image carrier from the first measurement means and the exposure amount of the exposure member from the second measurement means to obtain the second storage chamber The image forming apparatus according to any one of claims 1 to 3, wherein an enlarged volume is determined. The calculation means is accommodated in the second storage chamber using the number of rotations of the latent image carrier from the first measurement means and the exposure amount of the exposure member from the second measurement means. The image forming apparatus according to claim 4 , wherein a volume of the waste developer to be used is determined. The volume of the waste developer stored in the second storage chamber, which is determined by the calculation means, is the amount of transfer residual developer after transfer, the amount of drum fog developer, reverse rotation of the residual toner on the latent image carrier The image forming apparatus according to claim 5 , further comprising a developer amount by copying. Wherein the display means, when the waste developer can accommodate space rate reached the threshold value, one of the claims 1-6, characterized in that to display the full state of the waste developer in the second accommodating chamber the image forming apparatus according to any.

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