JP2012255832A - Image forming device and toner consumption method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device that improves image quality, and a toner consumption method.SOLUTION: The image forming device includes: an exposure part that performs exposure corresponding to exposure setting to form an electrostatic latent image on an image carrier; a first residual amount determination part 211 that determines whether toner enough for development remains in a developing part that performs development corresponding to development setting to develop the electrostatic latent image with the toner; a second residual amount determination part 203 that determines whether the toner enough for supply remains in a supplying part that supplies the toner to the developing part; a first switching part 213 that sets the exposure setting and development setting to toner consumption setting when it is determined that the toner enough for supply does not remain in the supply part; and a second switching part 215 that sets the exposure setting and development setting to print setting when it is determined that the toner enough for development does not remain in the developing part.

Description

  The present invention relates to an image forming apparatus and a toner consumption method.

  In an electrophotographic image forming apparatus, toner stored in a developing unit, for example, toner used in a non-magnetic one-component developing method, is charged by friction with a regulating blade and a supply roller in the developing unit. However, some of the toner stored in the developing unit is reversely charged due to peeling or burying of additives on the toner surface or adhesion between toners.

  When the reversely charged toner is used for development, it causes an image defect called toner fog. In addition, the reversely charged toner that has not been used for development stays and accumulates in the developing unit, for example, around the developing roller in the developing unit, and causes toner fog deterioration when the remaining amount of toner in the developing unit decreases. .

  For this reason, the amount of reversely charged toner is estimated from the toner consumption rate, and a patch image is formed at a timing corresponding to the toner consumption rate, thereby consuming the reversely charged toner staying and accumulating in the developing unit (outside the developing unit) (See, for example, Patent Documents 1 and 2).

  However, in the prior art as described above, the reversely charged toner amount is an estimated value based on the toner consumption rate, and therefore there is an error between the actual reversely charged toner amount. For this reason, even when a patch image is formed at a timing corresponding to the toner consumption rate, some reversely charged toner may remain in the developing unit and remain accumulated, and the amount increases with time. As a result, the image quality is degraded.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image forming apparatus and a toner consumption method capable of improving image quality.

  In order to solve the above-described problems and achieve the object, an image forming apparatus according to an aspect of the present invention includes an exposure unit that performs exposure according to exposure settings to form an electrostatic latent image on an image carrier. A first remaining amount determining unit that determines whether or not there is a developable amount of toner in a developing unit that performs development according to a development setting and develops the electrostatic latent image with toner; A second remaining amount determination unit that determines whether or not the replenishment unit that replenishes the replenishment unit has a replenishable amount of toner; and A first switching unit that switches the exposure setting and the development setting to a setting for toner consumption; and when it is determined that there is no developable amount of toner in the development unit, the exposure setting and the development setting are set for printing. And a second switching unit that switches to setting.

  The toner consumption method according to another aspect of the present invention includes an exposure step in which an exposure unit performs exposure according to exposure settings to form an electrostatic latent image on an image carrier, and a first remaining amount determination unit. A first remaining amount determining step for determining whether or not there is a developable amount of toner in a developing unit that performs development according to development settings and develops the electrostatic latent image with toner, and a first switching unit However, when it is determined that there is no replenishable amount of toner in the replenishment unit, a first switching step for switching the exposure setting and the development setting to a setting for toner consumption, and a second remaining amount determination unit, A second remaining amount determining step for determining whether or not there is a replenishable amount of toner in the replenishing unit that replenishes toner to the developing unit; and a second switching unit includes a developable amount of toner in the developing unit. If it is determined that the exposure setting and the development setting are not Characterized in that it comprises a second switching step of switching, to.

  According to the present invention, there is an effect that the image quality can be improved.

FIG. 1 is a mechanical configuration diagram illustrating an example of a printing apparatus according to the present embodiment. FIG. 2 is a mechanical configuration diagram illustrating an example of an image forming unit and a supply unit according to the present embodiment. FIG. 3 is a block diagram illustrating an example of a hardware configuration of the printing apparatus according to the present embodiment. FIG. 4 is a block diagram illustrating an example of a functional configuration of the printing apparatus according to the present embodiment. FIG. 5 is a flowchart illustrating an example of processing of the printing apparatus according to the present embodiment. FIG. 6 is a flowchart illustrating an example of the mode determination process of the present embodiment. FIG. 7 is a flowchart illustrating an example of toner empty determination processing for the replenishing unit according to the present exemplary embodiment. FIG. 8 is a flowchart illustrating an example of setting processing for toner consumption according to the present exemplary embodiment. FIG. 9 is a flowchart illustrating an example of the toner empty determination process for the developing unit according to the present exemplary embodiment. FIG. 10 is a flowchart illustrating an example of setting processing for printing according to the present embodiment.

  Hereinafter, embodiments of an image forming apparatus and a toner consumption method according to the present invention will be described in detail with reference to the accompanying drawings. In the following embodiments, the image forming apparatus of the present invention is an electrophotographic color printing apparatus, specifically, four colors of black (K), cyan (C), magenta (M), and yellow (Y). A case where the present invention is applied to a printing apparatus that forms an image will be described as an example, but the present invention is not limited to this. The image forming apparatus of the present invention can be applied to any color and monochrome as long as it is an apparatus that forms an image by an electrophotographic method. For example, an electrophotographic facsimile machine, a copying machine, and a multifunction peripheral (MFP) ) Etc. Note that a multifunction peripheral is a device having at least two functions among a printing function, a copying function, a scanner function, and a facsimile function.

  First, the configuration of the printing apparatus according to the present embodiment will be described.

  FIG. 1 is a mechanical configuration diagram illustrating an example of a printing apparatus 1 according to the present embodiment. As shown in FIG. 1, the printing apparatus 1 includes an image forming unit 10K, 10C, 10M, and 10Y, a replenishing unit 20K, 20C, 20M, and 20Y, an exposure unit 30, a transfer belt 40, and a driving roller 41. A tension roller 42, a density sensor 43, a paper feed tray 50, a paper feed roller 51, a registration roller 52, a secondary transfer roller 60, a waste toner box 61, a fixing unit 70, and a paper discharge roller. 80, a paper discharge table 81, and a double-sided roller 82.

  As shown in FIG. 1, the image forming units 10K, 10C, 10M, and 10Y and the replenishing units 20K, 20C, 20M, and 20Y are arranged from the upstream side in the moving direction (arrow S direction) of the transfer belt 40 with K, They are arranged along the transfer belt 40 in the order of C, M, and Y. As described above, the printing apparatus 1 according to the present embodiment uses a so-called tandem method, but is not limited thereto.

  The image forming unit 10K includes a photoreceptor 11K, a charger 12K, a developing unit 13K, a primary transfer roller 18K, and a cleaner blade 19K. The image forming unit 10K and the exposure unit 30 perform an image forming process (charging process, exposure process, developing process, transfer process, and cleaning process) on the photoconductor 11K, thereby forming a black toner image on the photoconductor 11K. Formed and transferred to the transfer belt 40.

  The image forming units 10C, 10M, and 10Y all have the same components as the image forming unit 10K. The image forming unit 10C forms a cyan toner image by performing an image forming process. The image forming unit 10M forms a magenta toner image by performing an image forming process, and the image forming unit 10Y forms a yellow toner image by performing an image forming process. Therefore, in the following, description will be made mainly on the components of the image forming unit 10K, and the components of the image forming units 10C, 10M, and 10Y will be denoted by K attached to the reference numerals of the components of the image forming unit 10K. Instead, only C, M, and Y are attached, and the description thereof is omitted. In this embodiment, non-magnetic one-component toner is used as the toner, but the present invention is not limited to this.

  The photoconductor 11K is an image carrier and is rotationally driven by a drive motor (not shown).

  First, in the charging step, the charger 12K that is in contact with the photoreceptor 11K uniformly charges the outer peripheral surface of the rotationally driven photoreceptor 11K in the dark.

Subsequently, in the exposure process, the exposure unit 30 performs exposure according to the exposure setting to form an electrostatic latent image on the photoreceptor 11K. Specifically, the exposure unit 30 exposes the charged surface of the photosensitive member 11K with the laser beam L _K corresponding to black, to form an electrostatic latent image corresponding to the black color component image on the surface of the photoreceptor 11K . The exposure unit 30, for the photoreceptor 11C, exposed with laser light L _C corresponding to cyan, the photoreceptor 11M, exposed with the laser beam L _M corresponding to magenta, for the photosensitive member 11Y, the yellow exposed with the laser beam L _Y corresponding to.

  Subsequently, in the developing process, the developing unit 13K performs development according to the development setting and develops the electrostatic latent image on the photoreceptor 11K with black toner. Specifically, the developing unit 13K develops the electrostatic latent image formed on the photoconductor 11K using black toner stored in the developing unit 13K, and generates a black toner image on the photoconductor 11K. Form.

  Subsequently, in the transfer process, the primary transfer roller 18K transfers the black toner image formed on the photoconductor 11K to the transfer belt 40 at a primary transfer position where the photoconductor 11K and the transfer belt 40 are in contact with each other. As a result, a black toner image is formed on the transfer belt 40. A small amount of untransferred toner remains on the photoreceptor 11K even after the toner image is transferred.

  Subsequently, in the cleaning process, the cleaner blade 19K wipes off the untransferred toner remaining on the photoreceptor 11K.

  The transfer belt 40 is an endless belt wound around a driving roller 41 and a tension roller 42, and moves endlessly in the direction of arrow S when the driving roller 41 is rotationally driven. First, a black toner image is transferred to the transfer belt 40 by the image forming unit 10K, then a cyan toner image is formed by the image forming unit 10C, a magenta toner image is formed by the image forming unit 10M, and yellow is formed by the image forming unit 10Y. The toner images are sequentially superimposed and transferred. As a result, a full-color toner image is formed on the transfer belt 40. The transfer belt 40 conveys the formed full-color toner image to a secondary transfer position where the driving roller 41 and the secondary transfer roller 60 are in contact with each other.

  The density sensor 43 detects the density of the toner image formed on the transfer belt 40. Specifically, the density sensor 43 irradiates the transfer belt 40 with a predetermined amount of light and reads the toner image or the amount of reflected light from the transfer belt 40 to thereby form a toner image formed on the transfer belt 40. Detect the density of. The surface roughness state on the transfer belt 40 differs depending on whether or not a toner image is formed on the transfer belt 40, and as a result, the amount of reflected light from the transfer belt 40 also differs. For this reason, it is possible to determine whether or not the developing unit to be checked among the developing units 13K, 13C, 13M, and 13Y has caused toner empty by the above method.

  In the paper feed tray 50, a plurality of recording papers are stacked and stored. The paper feed roller 51 is in contact with the recording paper located at the uppermost portion of the paper supply tray 50, and feeds the recording paper in contact with the recording paper by being rotationally driven. The registration roller 52 sends the recording paper fed by the paper feeding roller 51 to the secondary transfer position at a timing when the full color toner image conveyed by the transfer belt 40 overlaps the secondary transfer position.

  The secondary transfer roller 60 collectively transfers the full-color toner image conveyed by the transfer belt 40 onto the recording paper fed by the registration roller 52 at the secondary transfer position.

  The waste toner box 61 collects the toner remaining on the transfer belt 40 without being transferred to the pattern formed on the transfer belt 40 or the recording paper.

  The fixing unit 70 fixes the full color toner image on the recording paper by heating and pressurizing the recording paper on which the full color toner image is transferred.

  The paper discharge roller 80 discharges the recording paper on which the full-color toner image is fixed by the fixing unit 70 to a paper discharge table 81. In the case of performing duplex printing, the paper discharge roller 80 conveys the recording paper to the double-sided roller 82 by reversely rotating immediately before the recording paper passes through the paper discharge roller 80.

  The double-sided roller 82 conveys the recording sheet conveyed from the paper discharge roller 80 to the registration roller 52 again. The recording paper transported to the registration roller 52 is re-fed from the registration roller 52, the toner image is transferred to the surface opposite to the previous time by the secondary transfer roller 60, fixed by the fixing unit 70, and the paper discharge roller 80. As a result, the paper is discharged onto the paper discharge tray 81.

  FIG. 2 is a mechanical configuration diagram illustrating an example of the replenishing unit 20K and the image forming unit 10K according to the present embodiment. The replenishing unit 20K is a toner cartridge that can be attached to and detached from the developing unit 13K, and contains black toner for replenishment. When the remaining amount of black toner in the developing unit 13K becomes less than a certain amount, the replenishing unit 20K replenishes the developing unit 13K with black toner by driving a toner replenishing motor (not shown). The replenishing units 20C, 20M, and 20Y have different toner colors, but all have the same components as the replenishing unit 20K and perform the same operation as the replenishing unit 20K.

  As shown in FIG. 2, the developing unit 13K includes a developing roller 14K, a supply roller 15K, a regulating blade 16K, and a remaining amount sensor 17K. In the developing process, the developing roller 14K uses the black toner on the surface of the developing roller 14K to visualize the electrostatic latent image on the photoreceptor 11K. The supply roller 15K is rotatably in contact with the developing roller 14K, and supplies black toner stored in the developing unit 13K to the developing roller 14K. The regulating blade 16K is in contact with the developing roller 14K, thereby controlling the thickness of the black toner on the surface of the developing roller 14K to a predetermined amount, and at the same time frictionally charging the black toner on the surface of the developing roller 14K.

  The remaining amount sensor 17K is a sensor that detects the remaining amount of black toner stored in the developing unit 13K, and detects whether or not a certain amount of black toner is stored in the developing unit 13K. In the present embodiment, the remaining amount sensor 17K is an optical sensor, which outputs High when there is a certain amount of toner, and outputs Low when there is no certain amount of toner, but is limited to this. is not. For example, the remaining amount sensor 17K may be a powder detection sensor using a piezoelectric vibration element. Further, for example, the remaining amount sensor 17K may output an analog voltage value instead of a digital value.

  Further, when the remaining amount of black toner stored in the developing unit 13K becomes less than a certain amount, black toner is replenished from the replenishing unit 20K to the developing unit 13K. Therefore, the remaining amount sensor 17K includes the toner of the replenishing unit 20K. Also used to detect empty. For example, if the remaining amount sensor 17K outputs Low for a predetermined time or more, it can be determined that the replenishing unit 20K is toner empty.

  The developing units 13C, 13M, and 13Y are different in toner color used for development, but all have the same components as the developing unit 13K and perform the same operation as the developing unit 13K.

  In the following description, when it is not necessary to distinguish the image forming units 10K, 10C, 10M, and 10Y, the image forming units 10 may be simply referred to as the image forming unit 10, and the photoreceptors 11K, 11C, 11M, and 11Y may be referred to as “image forming units 10”. When there is no need to distinguish between them, the photoconductor 11 may be simply referred to, and when it is not necessary to distinguish between the developing units 13K, 13C, 13M, and 13Y, the developing unit 13 may be simply referred to as the developing roller 14K, When it is not necessary to distinguish 14C, 14M, and 14Y, they may be simply referred to as the developing roller 14, and when it is not necessary to distinguish between the replenishing units 20K, 20C, 20M, and 20Y, they are simply referred to as the replenishing unit 20. There is a case.

  FIG. 3 is a block diagram illustrating an example of a hardware configuration of the printing apparatus 1 according to the present embodiment. The printing apparatus 1 includes an operation panel I / F 101, an operation panel 103, NVRAM (Non Volatile Random Access Memory) 105K, 105C, 105M, and 105Y, an external I / F 107, an image processing IC 109, and an I / O 111. ROM (Read Only Memory) 113, RAM 115, and CPU (Central Processing Unit) 117, and these devices are connected to each other via a system bus 119. The printing apparatus 1 also includes electrical components such as remaining amount sensors 17K, 17C, 17M, and 17Y, a drive motor 121, and a density sensor 43, a high-voltage output unit 123, and the like.

  The operation panel I / F 101 is an interface between the operation panel 103 and the system bus 119. The operation panel 103 inputs settings for various modes of the printing apparatus 1 to the CPU 117 via the operation panel I / F 101.

  The NVRAMs 105K, 105C, 105M, and 105Y are mounted on the replenishing units 20K, 20C, 20M, and 20Y, respectively, and the number of printed sheets using the toner of the mounted replenishing unit 20 and the replenishing units that are mounted. 20 toner consumption amounts are stored.

  The external I / F 107 is a communication I / F with an external device (not shown) such as a host computer.

  If the exposure setting is a setting for printing, the image processing IC 109 acquires black, cyan, magenta, and yellow image data generated by a controller (not shown) and transmits the image data to the exposure unit 30. Thereby, the exposure unit 30 performs exposure for forming an electrostatic latent image based on image data of the corresponding color on each of the photoreceptors 11K, 11C, 11M, and 11Y. The image processing IC 109 counts the number of pixels of the acquired black, cyan, magenta, and yellow image data. Further, if the exposure setting is a setting for toner consumption, the image processing IC 109 generates a predetermined image pattern of the toner color to be consumed and transmits it to the exposure unit 30. In the present embodiment, the image processing IC 109 generates a solid image pattern as a predetermined image pattern. Thereby, the exposure unit 30 performs exposure for forming an electrostatic latent image on the photosensitive member 11 corresponding to the toner color to be consumed based on the solid image pattern of the toner color to be consumed. That is, the exposure unit 30 exposes the entire surface of the photoreceptor 11. For this reason, when the exposure setting of the image processing IC 109 is a setting for toner consumption, the exposure unit 30 exposes the photosensitive member 11 more than the exposure for printing (exposure when the exposure setting is a setting for printing). The exposure is increased.

  The I / O 111 is an interface between the system bus 119 and electrical components such as the remaining amount sensors 17K, 17C, 17M, and 17Y, the drive motor 121, and the concentration sensor 43, the high-voltage output unit 123, and the like. The drive motor 121 is a drive source such as the image forming units 10K, 10C, 10M, and 10Y, and the drive roller 41.

  If the development setting is a setting for printing, the high-voltage output unit 123 receives a PWM (Pulse Width Modulation) signal from the I / O 111 in which the duty ratio is set to a voltage value that is a toner adhesion amount suitable for printing. Input for each color. The toner adhesion amount varies depending on the usage environment of the printing apparatus, and the color of the print output changes depending on the toner adhesion amount. Determined by the control in consideration. The high voltage output unit 123 outputs a voltage value corresponding to the duty ratio of the input PWM signal to the developing roller 14 corresponding to the toner color, and applies the developing roller 14 at a voltage indicated by the voltage value. As a result, each of the developing rollers 14K, 14C, 14M, and 14Y attaches an amount of toner suitable for printing to a portion where the electrostatic latent image is formed on the corresponding photosensitive member 11, and the electrostatic latent image Develop. On the other hand, if the development setting is a setting for toner consumption, a PWM (Pulse Width Modulation) signal whose duty ratio is set to the maximum voltage value for development is input from the I / O 111 to the high voltage output unit 123. . The high voltage output unit 123 outputs a voltage value corresponding to the duty ratio of the input PWM signal to the developing roller 14 corresponding to the toner color to be consumed. As a result, the developing roller 14 develops the electrostatic latent image by attaching all the toner in the corresponding portion on the surface of the developing roller 14 to the portion where the electrostatic latent image on the corresponding photoconductor 11 is formed. . Therefore, when the development setting is a setting for toner consumption, the developing unit 13 has a larger amount of toner adhering to the photoreceptor 11 than the development for printing (development when the development setting is a setting for printing). Development will be performed. The CPU 117 manages development settings on the RAM 115.

  The ROM 113 stores a control program executed by the CPU 117 and the like. The RAM 115 is used as a main memory and a work area of the CPU 117. Specifically, the RAM 115K, 105C, 105M, and 105Y and the data expansion area stored in the ROM 113 and the remaining amount sensors 17K, 17C, 17M, And 17Y, and a temporary storage area for data detected by the density sensor 43. The RAM 115 can be expanded in memory capacity by an optional RAM connected to an expansion port (not shown). The CPU 117 comprehensively controls access to each device connected to the system bus 119 based on a control program stored in the ROM 113 and each electrical component connected via the I / O 111. And input / output to / from the high voltage output unit 123 and the like. The CPU 117 communicates with an external device such as a host computer via the external I / F 107.

  FIG. 4 is a block diagram illustrating an example of a functional configuration of the printing apparatus 1 according to the present embodiment. The printing apparatus 1 includes a mode determination unit 201, a second remaining amount determination unit 203, a storage unit 205, a consumption rate calculation unit 207, a main control unit 209, a first remaining amount determination unit 211, and a first switching. A unit 213 and a second switching unit 215. In the present embodiment, the mode determination unit 201, the first remaining amount determination unit 203, the consumption rate calculation unit 207, the main control unit 209, the second remaining amount determination unit 211, the first switching unit 213, and the second switching unit 215 include The storage unit 205 is realized by the NVRAM 105K, 105C, 105M, and 105Y, but is not limited thereto.

  The mode determination unit 201 determines whether or not it is a toner consumption mode in which the exposure setting and the development setting are switched to a setting for toner consumption. Specifically, the mode determination unit 201 determines whether or not the mode for which setting input has been performed through the operation panel 103 is the toner consumption mode. Note that the printing apparatus 1 may omit the mode determination unit 201.

  The second remaining amount determination unit 203 determines whether or not there is an amount of toner that can be supplied in each of the supply units 20K, 20C, 20M, and 20Y. Specifically, the second remaining amount determination unit 203 determines whether or not the corresponding replenishment unit 20 is toner empty from the output values of the remaining amount sensors 17K, 17C, 17M, and 17Y.

  The storage unit 205 stores the number of printed sheets and the amount of toner consumed by the replenishing units 20K, 20C, 20M, and 20Y. Since the replenishing unit 20 is detachable from the corresponding developing unit 13, the storage unit 205 stores the toner consumption amount and the number of printed sheets after the replenishing unit 20 is attached to the corresponding developing unit 13.

  The consumption rate calculation unit 207 calculates the toner consumption rate of the corresponding replenishment unit 20 using the number of printed sheets and the toner consumption amount of the replenishment units 20K, 20C, 20M, and 20Y stored in the storage unit 205. For example, the consumption rate calculation unit 207 calculates the toner consumption rate per A4 size recording sheet using Equation (1).

  Toner consumption rate [%] = toner consumption / (toner consumption of A4 size full-color image × number of printed sheets) (1)

  Note that the consumption rate calculation unit 207 uses the toner consumption amounts of the replenishing units 20K, 20C, 20M, and 20Y stored in the storage unit 205 as the corresponding color image data counted by the image processing IC 109. To the value obtained by adding the number of pixels. Further, the consumption rate calculation unit 207 increments the number of printed sheets of the replenishing units 20K, 20C, 20M, and 20Y stored in the storage unit 205.

  The main control unit 209 determines whether the exposure setting and the development setting are to be switched by the first switching unit 213 to the setting for toner consumption or the second switching unit 215 is switched to the setting for printing.

  For example, assume that the mode determination unit 201 determines that the toner consumption mode is set, and the second remaining amount determination unit 203 determines that any of the replenishing units 20K, 20C, 20M, and 20Y is toner empty. In this case, the main control unit 209 notifies the first switching unit 213 that the toner is empty, and switches the toner color exposure setting and development setting of the toner empty to the setting for toner consumption.

  Further, for example, it is determined that the mode determination unit 201 determines that the toner consumption mode is set, and the second remaining amount determination unit 203 determines that none of the replenishment units 20K, 20C, 20M, and 20Y is toner empty. In this case, the main control unit 209 determines whether the toner consumption rates of the replenishing units 20K, 20C, 20M, and 20Y calculated by the consumption rate calculation unit 207 are less than a threshold value. If the toner consumption rate of any of the replenishing units 20K, 20C, 20M, and 20Y is less than the threshold value, the main control unit 209 notifies the first switching unit 213 that the toner consumption rate is less than the threshold value. The toner color exposure setting and development setting are switched to a setting for toner consumption. Here, the threshold value can be set based on an experimental result indicating a relationship between the toner consumption rate and the toner fog state. Note that the amount of reversely charged toner tends to increase as the toner consumption rate decreases. As a result of this experiment, when the toner consumption rate is less than 1%, the toner fog state is equal to or higher than a predetermined level (a level at which the user can recognize that a defect has occurred on the image). For this reason, in the present embodiment, the threshold is set to 1%, but the present invention is not limited to this.

  For example, when the main control unit 209 receives a notification of completion of setting for toner consumption of a predetermined toner color from the first switching unit 213, the main control unit 209 prints the exposure setting and development setting of the toner color on the second switching unit 215. Switch to the setting for.

  For example, when the second remaining amount determination unit 203 determines that two or more replenishment units 20 are toner empty, the main control unit 209 causes the first switching unit 213 to supply the toner colors of the two or more replenishment units 20. One of the toner color exposure settings and development settings is switched to a toner consumption setting. The main control unit 209 receives a notification of completion of setting for toner consumption of the one toner color from the first switching unit 213, and then sends the toner color of the two or more supply units 20 to the first switching unit 213. The exposure setting and development setting for other toner colors are switched to the settings for toner consumption.

  When the main switching unit 209 causes the first switching unit 213 to switch the toner color exposure setting and development setting to the toner consumption setting, the main control unit 209 receives a notification of completion of the toner consumption setting for the toner color. Until this time, the drive motor 121 is always driven, and the toner color image forming unit 10 and the drive roller 41 to be consumed are always driven. However, the main control unit 209 does not feed the recording paper by the paper feed roller 51. That is, when the exposure setting and the development setting are settings for toner consumption, the image forming unit 10 forms the toner image, transfers the formed toner image to the transfer belt 40, and the waste toner box 61 transfers the transfer belt. The toner (toner image) on 40 is repeatedly collected.

  The first remaining amount determination unit 211 determines whether there is a developable amount of toner in each of the developing units 13K, 13C, 13M, and 13Y. Specifically, the first remaining amount determination unit 211 determines whether the developing unit 13K, 13C, 13M, or 13Y is based on the output value of the density sensor 43 that outputs the density of the toner image formed on the transfer belt 40. It is determined whether or not the developing unit to be checked is causing toner empty.

  Upon receiving an instruction from the main control unit 209, the first switching unit 213 switches the exposure setting and development setting of the instructed toner color to settings for toner consumption. In addition, when the first switching unit 213 is notified from the main control unit 209 that the toner is empty, the first remaining amount determination unit 211 determines that the instructed toner color developing unit 13 is toner empty. Then, the main control unit 209 is notified of completion of setting for toner consumption of the toner color. In addition, when notified from the main control unit 209 that the toner consumption rate is less than the threshold value, the first switching unit 213 sets a timer to measure a certain period, and when the certain period elapses, the first toner is instructed. The main control unit 209 is notified of the completion of the color toner consumption setting. For example, the fixed period may be a period required for the developing roller 14 corresponding to the instructed toner color to make one revolution, but is not limited thereto.

  The second switching unit 215 receives an instruction from the main control unit 209 and switches the exposure setting and the development setting of the specified toner color to the setting for printing.

  Next, the operation of the printing apparatus according to the present embodiment will be described.

  FIG. 5 is a flowchart illustrating an example of processing of the printing apparatus 1 according to the present embodiment.

  First, the mode determination unit 201 performs a mode determination process (step S100).

  FIG. 6 is a flowchart illustrating an example of the mode determination process of the present embodiment.

  First, the mode determination unit 201 reads a mode set and input by the operation panel 103 (step S200).

  Subsequently, the mode determination unit 201 determines whether or not the read mode is the toner consumption mode (step S202).

  Subsequently, when the read mode is the toner consumption mode (Yes in step S202), the mode determination unit 201 notifies the main control unit 209 that the mode is the toner consumption mode (step S204).

  On the other hand, if the read mode is not the toner consumption mode (No in step S202), the mode determination unit 201 notifies the main control unit 209 that the mode is not the toner consumption mode (step S206).

  Returning to FIG. 5, if the main control unit 209 is in the toner consumption mode (Yes in step S102), the main control unit 209 specifies an unspecified toner color to the second remaining amount determination unit 203 (step S104), and the specified toner. The toner empty of the supply unit 20 corresponding to the color is checked. If the main control unit 209 is not in the toner consumption mode (No in step S102), the main control unit 209 ends the process.

  Subsequently, the second remaining amount determination unit 203 performs a toner empty determination process of the replenishment unit 20 corresponding to the designated toner color (step S106).

  FIG. 7 is a flowchart illustrating an example of a toner empty determination process for the replenishing unit 20 according to the present exemplary embodiment.

  First, the second remaining amount determination unit 203 reads the output value of the remaining amount sensor 17 corresponding to the designated toner color (step S300).

  Subsequently, the second remaining amount determination unit 203 determines whether or not the read output value is Low for a certain time (step S302).

  Subsequently, if the read output value is Low for a certain time (Yes in Step S302), the second remaining amount determination unit 203 sends the toner empty of the replenishment unit 20 corresponding to the designated toner color to the main control unit 209. Notification is made (step S304).

  On the other hand, if the read output value is not Low for a certain period of time (No in step S302), the second remaining amount determination unit 203 notifies the main control unit 209 that there is toner in the replenishment unit 20 corresponding to the designated toner color. (Step S306).

  Returning to FIG. 5, if the replenishing unit 20 corresponding to the designated toner color is toner empty (Yes in step S108), the main control unit 209 notifies the first switching unit 213 that the toner is empty, and An instruction is given to switch the toner empty exposure setting and development setting to the toner consumption setting (step S110).

  On the other hand, if the replenishment unit 20 corresponding to the designated toner color is not toner empty (No in step S108), the consumption rate calculation unit 207 prints the number of prints of the replenishment unit 20 corresponding to the toner color designated by the main control unit 209. The toner consumption amount is read from the storage unit 205, and the toner consumption rate is calculated (step S112).

  Subsequently, the main control unit 209 determines whether or not the toner consumption rate calculated by the consumption rate calculation unit 207 is less than a threshold value (step S114).

  Subsequently, if the toner consumption rate calculated by the consumption rate calculation unit 207 is less than the threshold (Yes in Step S114), the main control unit 209 notifies the first switching unit 213 to that effect and also uses the toner consumption rate. Is instructed to switch the toner color exposure setting and development setting to a setting for toner consumption (step S116).

  On the other hand, if the toner consumption rate calculated by the consumption rate calculation unit 207 is equal to or greater than the threshold (No in step S114), the process proceeds to step S124.

  Subsequently, the first switching unit 213 performs setting processing for toner consumption of the designated toner color exposure setting and development setting (step S118).

  FIG. 8 is a flowchart illustrating an example of setting processing for toner consumption according to the present exemplary embodiment.

  First, the first switching unit 213 changes the toner color exposure setting specified by the main control unit 209 managed by the image processing IC 109 to the toner consumption setting, that is, the photoconductor corresponding to the specified toner color. 11 is set to “entire surface” indicating exposure of the entire surface (step S400).

  Subsequently, the first switching unit 213 changes the toner color development setting designated by the main control unit 209 managed on the RAM 115 to the toner consumption setting, that is, the duty ratio of the PWM signal. It is set to “forced consumption” indicating that the maximum voltage value for development is maximized (step S402).

  By setting in step S400 and step S402, it is possible to deposit all the toner on the surface of the developing roller 14 corresponding to the designated toner color on the corresponding photoreceptor 11.

  Subsequently, if the first switching unit 213 is notified that the replenishment unit 20 corresponding to the toner color designated by the main control unit 209 is toner empty (Yes in step S404). The designated toner color is also designated to the first remaining amount determination unit 211, and the toner empty of the developing unit 13 corresponding to the designated toner color is checked.

  Subsequently, the first remaining amount determination unit 211 performs toner empty determination processing of the developing unit 13 corresponding to the designated toner color (step S406).

  FIG. 9 is a flowchart illustrating an example of a toner empty determination process for the developing unit 13 according to the present exemplary embodiment.

  First, the first remaining amount determination unit 211 reads the output value of the concentration sensor 43 (step S500).

  Subsequently, the first remaining amount determination unit 211 determines whether a toner image of the designated toner color is formed on the transfer belt 40 from the read output value (step S502).

  Subsequently, if the toner image of the designated toner color is not formed on the transfer belt 40 (No in step S502), the first remaining amount determination unit 211 of the developing unit 13 corresponding to the designated toner color. Toner empty is notified to the first switching unit 213 (step S504).

  On the other hand, if the toner image of the designated toner color is formed on the transfer belt 40 (Yes in step S502), the first remaining amount determination unit 211 determines the toner of the developing unit 13 corresponding to the designated toner color. The presence is notified to the first switching unit 213 (step S506).

  Returning to FIG. 8, the first switching unit 213 repeats the toner empty determination process of the developing unit 13 until the first remaining amount determining unit 211 notifies the toner empty of the developing unit 13 corresponding to the designated toner color. (No in step S408). The first switching unit 213 notifies the main control unit 209 of completion of setting for toner consumption of the designated toner color when the toner empty is notified from the first remaining amount determination unit 211 (Yes in step S408). (Step S410).

  On the other hand, in step S404, if there is no notification that the replenishment unit 20 corresponding to the toner color designated by the main control unit 209 is toner empty (No in step S404), the first switching unit 213 displays the timer. Is set (step S412), and a certain period of time is awaited (No in step S414). The first switching unit 213 notifies the main control unit 209 of completion of setting for toner consumption of the designated toner color when a certain period of time has passed (Yes in step S414) (step S410).

  Returning to FIG. 5, the main control unit 209 then instructs the second switching unit 215 to switch the toner color exposure setting and the development setting to the printing setting to complete the setting for toner consumption (step S <b> 120). ).

  Subsequently, the second switching unit 215 performs setting processing for printing the exposure setting and development setting of the designated toner color (step S122).

  FIG. 10 is a flowchart illustrating an example of setting processing for printing according to the present embodiment.

  First, the second switching unit 215 sets the exposure setting of the toner color designated by the main control unit 209 managed by the image processing IC 109 to “print” which is a setting for printing (step S600).

  Subsequently, the second switching unit 215 sets the development setting of the toner color designated by the main control unit 209 managed on the RAM 115 to “print” which is a setting for printing (step S602).

  Returning to FIG. 5, if the main controller 209 has designated all the toner colors to the second remaining amount determining unit 203 (Yes in step S124), the process is terminated, and the undesignated toner. If the color remains (No in step S124), the process returns to step S104.

  As described above, in the present embodiment, when the replenishing unit becomes toner empty, the toner in the developing unit is forcibly consumed until the corresponding developing unit also becomes toner empty. For this reason, according to the present embodiment, the reversely charged toner staying and accumulating in the developing unit can be forcibly consumed periodically, so that deterioration of image defects such as toner fog can be prevented and image quality can be improved. it can.

  In this embodiment, when the toner is forcibly consumed, the toner on the surface of the developing roller is set to adhere to the corresponding photosensitive member, so that the time required for the forcible consumption of the toner can be shortened. it can.

  In this embodiment, the toner is forcibly consumed for a certain period even when the toner consumption rate is low, that is, when development is performed at a low printing rate at which reversely charged toner is likely to be generated. Can also be suppressed.

  In this embodiment, since the toner empty of the developing unit is determined from the density of the toner image, it is not necessary to install a sensor for detecting the toner empty of the developing unit in the developing unit, and it can be applied to a small image forming apparatus. it can.

  In the present embodiment, whether to forcibly consume toner can be set depending on whether the toner consumption mode is set. The forced consumption of toner can improve the image quality, but the amount of toner consumption increases, so the number of printable sheets decreases. Therefore, according to the present embodiment, the user can set whether to give priority to quality or cost.

  In the present embodiment, the forcible consumption of toner in a plurality of developing units is not performed simultaneously but sequentially. When a large amount of toner is fed into the waste toner box, toner clogging may occur. Therefore, according to the present embodiment, it is possible to prevent toner clogging.

(Modification)
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible.

1 Printing device 10K, 10C, 10M, 10Y Image forming unit 11K, 11C, 11M, 11Y Photoconductor 12K, 12C, 12M, 12Y Charger 13K, 13C, 13M, 13Y Developing unit 14K Developing roller 15K Supply roller 16K Regulating blade 17K Remaining amount sensor 18K, 18C, 18M, 18Y Primary transfer roller 19K, 19C, 19M, 19Y Cleaner blade 20K, 20C, 20M, 20Y Supply unit 30 Exposure unit 40 Transfer belt 41 Drive roller 42 Tension roller 43 Density sensor 50 Paper feed tray 51 Paper Feeding Roller 52 Registration Roller 60 Secondary Transfer Roller 61 Waste Toner Box 70 Fixing Unit 80 Paper Discharge Roller 81 Paper Discharge Stand 82 Double-Sided Roller 101 Operation Panel I / F
103 Operation panel 105K, 105C, 105M, 105Y NVRAM
107 External I / F
109 Image processing IC
111 I / O
113 ROM
115 RAM
117 CPU
119 system bus 121 drive motor 123 high voltage output unit 201 mode determination unit 203 second remaining amount determination unit 205 storage unit 207 consumption rate calculation unit 209 main control unit 211 first remaining amount determination unit 213 first switching unit 215 second switching unit

JP 2000-162828 A JP 2002-287499 A

Claims (7)

An exposure unit that performs exposure according to the exposure setting to form an electrostatic latent image on the image carrier;
A first remaining amount determining unit that determines whether or not there is a developable amount of toner in a developing unit that performs development according to a development setting and develops the electrostatic latent image with toner;
A second remaining amount determination unit that determines whether or not the replenishment unit that replenishes toner to the developing unit includes a replenishable amount of toner;
A first switching unit that switches the exposure setting and the development setting to a setting for toner consumption when it is determined that there is no toner that can be replenished in the replenishing unit;
A second switching unit that switches the exposure setting and the development setting to a setting for printing when it is determined that there is no developable amount of toner in the development unit;
An image forming apparatus comprising: When the exposure setting is the setting for toner consumption, the exposure unit performs exposure in which the exposure area of the image carrier is larger than the exposure for printing, and the exposure setting is the setting for printing. If the exposure for printing,
When the development setting is the setting for toner consumption, the developing unit performs development in which the amount of toner attached to the image carrier is larger than that for printing, and the development setting is the setting for printing. The image forming apparatus according to claim 1, wherein the development for printing is performed. A storage unit for storing the number of printed sheets using the toner of the replenishing unit and the toner consumption amount of the replenishing unit;
A consumption rate calculation unit that calculates a toner consumption rate using the number of printed sheets and the toner consumption amount,
The first switching unit switches the exposure setting and the development setting to the toner consumption setting when it is determined that there is a replenishable amount of toner in the replenishment unit and the toner consumption rate is less than a threshold value. ,
The second switching unit switches the exposure setting and the development setting to the print setting after a certain period of time has elapsed since the exposure setting and the development setting are switched to the toner consumption setting. The image forming apparatus according to claim 1.   The first remaining amount determining unit determines whether there is a developable amount of toner in the developing unit from the density of a toner image obtained by developing the electrostatic latent image. 4. The image forming apparatus according to any one of items 3. A mode determination unit that determines whether the exposure setting and the development setting are in a toner consumption mode for switching to the setting for toner consumption;
The said 1st switch part further switches the said exposure setting and the said development setting to the setting for toner consumption, when it determines with it being the said toner consumption mode. The image forming apparatus according to claim 1. The image carrier, the developing unit, and the replenishing unit are prepared for each toner color,
The first remaining amount determining unit determines whether there is a developable amount of toner in each of the plurality of developing units,
The second remaining amount determination unit determines whether there is a replenishable amount of toner in each of the plurality of supply units,
When it is determined that there is no replenishable amount of toner in two or more of the plurality of replenishing units, the first switching unit selects one of the toner colors of the two or more replenishing units. The exposure setting and the development setting are switched to toner consumption settings, and it is determined that there is no developable amount of toner in the developing portion of the one toner color. The image forming apparatus according to claim 1, wherein the exposure setting and the development setting for other toner colors are switched to a setting for toner consumption. An exposure step in which the exposure unit performs exposure according to the exposure setting to form an electrostatic latent image on the image carrier;
A first remaining amount determining unit that determines whether or not there is a developable amount of toner in the developing unit that develops the electrostatic latent image with toner by performing development according to development settings. When,
A first switching step for switching the exposure setting and the development setting to a toner consumption setting when the first switching unit determines that there is no replenishable amount of toner in the replenishing unit;
A second remaining amount determining step for determining whether or not there is an amount of toner that can be replenished in the replenishing unit that replenishes toner to the developing unit;
A second switching step for switching the exposure setting and the development setting to a setting for printing when the second switching unit determines that there is no developable amount of toner in the developing unit;
A toner consuming method comprising:

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