JP5866899B2 - Image forming apparatus, image forming apparatus control method, and image forming apparatus control program - Google Patents

Description

  The present invention relates to an image forming apparatus, an image forming apparatus control method, and an image forming apparatus control program, and in particular, an electrophotographic image forming apparatus capable of detecting that an abnormality has occurred in a toner replenishing operation to a developing device. The present invention relates to an image forming apparatus control method and an image forming apparatus control program.

  In an electrophotographic image forming apparatus (scanner function, facsimile function, copying function, function as a printer, data communication function, server function, MFP (Multi Function Peripheral), facsimile apparatus, copying machine, printer, etc.) Image formation (printing) is performed while supplying toner from a toner container such as a toner bottle to a developing device for developing a toner image. When most of the toner in the toner container is consumed, or when a toner replenishment operation failure (toner replenishment abnormality) occurs, toner is not replenished to the developing device, and printing cannot be performed. In order to detect this, for example, a detection sensor is provided in the developing unit to detect the amount of toner in the developing unit.

  Note that the following Patent Document 1 discloses a low toner concentration when, for example, an image having a high BW ratio is continuously printed, and the toner concentration suddenly drops below the abnormality determination value after the toner empty is approached. An image forming apparatus that can prevent erroneous determination as abnormal is disclosed. In this image forming apparatus, after the toner near empty is detected, it is determined that the toner has a low density abnormality when it is continuously detected a predetermined number of times that the toner density is equal to or lower than the abnormality determination value lower than the empty determination value. . Further, when it is detected a predetermined number of times that the toner density is equal to or less than the empty determination value, it is determined that the toner is empty.

JP 2009-15050 A

  By the way, as the toner replenishment abnormality to the developing device, conventionally, a phenomenon that toner is hardly replenished has been assumed. This may be caused by, for example, a defect in a toner amount detection sensor, a failure in a motor for supplying toner, or a mistake in attaching a wiring to these parts. . However, in addition to such a phenomenon that the toner is hardly replenished, a phenomenon that the toner replenishment amount is somewhat smaller than normal and the toner is supplied little by little may occur as a toner replenishment abnormality. is there.

  When a toner replenishment abnormality in which toner is replenished little by little occurs, printing may not be performed properly, for example, a solid image (an image with a filled area) may be blurred. In addition, since toner replenishment is not in time for consumption, forced toner replenishment operations are frequently performed, and printing is interrupted each time, so that the life of the image forming apparatus is adversely affected. Sexuality may deteriorate. Therefore, even when such a toner replenishment abnormality occurs, it is necessary to quickly detect it.

  Such a toner replenishment abnormality may be caused by, for example, the toner supply path from the toner bottle being slightly blocked (for example, a Mylar disposed at the junction between the toner bottle and the developing device is turned over and the toner supply port is blocked). Or when the shutter provided in the toner bottle is not completely opened.), And the stirring blade provided in the toner bottle may be damaged. is there.

  As a condition for determining that the toner supply abnormality has occurred, for example, it may be determined that the toner supply abnormality has occurred in the following case. In other words, when the detection value of the sensor for detecting the toner does not change for a certain period of time, or even after the toner supply operation is forcibly performed before becoming nearly empty, it is determined that the toner amount is recovered from the detection result of the sensor. This is the case when it is not possible. However, conventionally, it may be difficult to determine that such a toner replenishment abnormality has occurred so that the toner is supplied little by little.

  That is, even if this type of toner replenishment abnormality occurs, a small amount of toner is replenished. Therefore, the detection value of the sensor that detects toner changes with the toner replenishment operation, and cannot be determined to be in an abnormal state. There is a case. Even if the toner is forcibly replenished, the amount of toner is recovered to some extent, so it is difficult to determine that there is an abnormality.

  In addition, when a method using a transmissive sensor or the like is adopted as a method for detecting the amount of toner in the developing device, it is difficult to determine the toner replenishment abnormality described above. It is mentioned as a reason. That is, in an image forming apparatus that performs one-component development, a transmissive sensor or the like is often used as a sensor that detects toner in the developing device in order to reduce costs. However, with such a transmissive sensor, it is possible to detect the presence or absence of toner at a portion detected by the sensor, but it is difficult to detect the amount of toner in the developing device. On the other hand, in order to detect the amount of toner in the developing unit, for example, a method of measuring the weight of the developing unit may be considered, but such a method increases the manufacturing cost of the image forming apparatus.

  Further, for example, the attachment position of a sensor for detecting toner may be cited as a reason why it is difficult to determine the toner supply abnormality. That is, the detection of the toner amount is desirably performed in the toner buffer unit where the toner is stirred and consumed in the developing device. For this reason, conventionally, for example, a configuration in which a light guide is attached to a developing device and the toner in the toner buffer unit is detected by a transmission type detection sensor or the like has been used. However, in recent years, in order to reduce the size and cost of the developing device, an increasing number of devices are provided with a detection sensor on the toner supply port side of the developing device to detect toner. It takes a certain amount of time for the toner to flow from the toner supply port to the toner buffer. For this reason, when the detection sensor is provided on the toner replenishing port side away from the toner buffer portion in this way, even if the toner replenishment abnormality actually occurs, it takes time until the influence of the toner replenishment abnormality reaches the toner buffer portion. It takes. For this reason, it may take time to determine that a toner replenishment abnormality has occurred, or it may be erroneously determined that a toner replenishment abnormality has occurred.

  The present invention has been made in order to solve such a problem, and can form an image that can be determined earlier and more reliably that an abnormal state in which the amount of toner supply is reduced has occurred. It is an object of the present invention to provide an image forming apparatus, an image forming apparatus control method, and an image forming apparatus control program.

In order to achieve the above object, according to one aspect of the present invention, an image forming apparatus includes: a toner container; a developer that receives supply of toner from the toner container; and a detection unit that detects information relating to the amount of toner in the developer. A supply unit for supplying toner to the developing device according to a detection result of the detection unit; an acquisition unit for acquiring a supply time for supplying toner by the supply unit; and a first number for calculating the number of dots of an image to be formed. 1 calculating means, and judging means for judging whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated by the first calculating means and the replenishment time obtained by the obtaining means. comprising, first calculating means, as the number of dot images, calculates the average value of the number of dots a predetermined number of image, a predetermined number of sheets, their bets from the site where the toner is detected by the detection means in the developing device Over at least the number of sheets to be imaged while the toner to flow to the site that is consumed.
According to another aspect of the present invention, an image forming apparatus includes: a toner container; a developer that receives supply of toner from the toner container; a detection unit that detects information about the amount of toner in the developer; A replenishing unit for replenishing toner to the developing device according to the detection result, an acquiring unit for obtaining a replenishment time in which the toner is replenished by the replenishing unit, and a first calculating unit for calculating the number of dots of an image to be formed Determining means for determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated by the first calculating means and the replenishment time acquired by the acquiring means, and the acquiring means comprises As the replenishment time, an average value of toner replenishment times for a predetermined number of sheets is calculated. It is not less than the number of sheets to be imaged during the movement.
Preferably, the first calculation means calculates an average value of the number of dots of the image for a predetermined number as the number of dots of the image.

  Preferably, the determination unit calculates the increase amount of the replenishment time with respect to the number of dots of the image based on the number of dots of the image calculated by the first calculation unit and the replenishment time acquired by the acquisition unit. Means for determining that a toner replenishment abnormality has occurred when the amount of increase calculated by the second calculation means is equal to or greater than a predetermined value.

  Preferably, in the case where the toner container is replaced after the occurrence of a toner empty state in which toner is insufficient, the determination unit is configured such that the accumulated value of the number of dots calculated by the first calculation unit after the replacement of the toner container is a predetermined value. Until this is the case, it is not determined that the toner replenishment abnormality has occurred.

  Preferably, when the toner container is replaced after the occurrence of a toner empty state in which toner is insufficient, the determination unit has a cumulative value of the replenishment time acquired by the acquisition unit after the replacement of the toner container exceeds a predetermined value. Until then, it is not determined that the toner replenishment abnormality has occurred.

  Preferably, in a case where the toner container is replaced after the occurrence of a toner empty state in which the toner is insufficient, the determination unit is configured to replace the toner container until the cumulative value of the number of sheets on which the image is formed becomes equal to or greater than a predetermined value. Therefore, it is not determined that the toner replenishment abnormality has occurred.

  Preferably, the determination unit does not determine that a toner replenishment abnormality has occurred if the cumulative value of the number of dots calculated by the first calculation unit is equal to or greater than a predetermined value.

  Preferably, the determination unit does not determine that a toner replenishment abnormality has occurred if the cumulative value of the replenishment time acquired by the acquisition unit is greater than or equal to a predetermined value.

  Preferably, the determination unit does not determine that a toner replenishment abnormality has occurred if the cumulative value of the number of sheets on which images are formed is equal to or greater than a predetermined value.

Preferably, the determination unit determines that the toner is in a toner-empty state when the increase rate of the replenishment time acquired by the acquisition unit with respect to the number of dots calculated by the first calculation unit is equal to or greater than a predetermined value.

  Preferably, when a predetermined period has elapsed since the previous image formation, the determination unit supplies toner until the cumulative value of the replenishment time acquired by the acquisition unit becomes equal to or greater than a predetermined value after the predetermined period has elapsed. It is not judged that an abnormality has occurred.

  Preferably, in a case where a predetermined period has elapsed since the last image formation, the determination means until the cumulative value of the number of dots calculated by the first calculation means reaches a predetermined value or more after the predetermined period has elapsed. Therefore, it is not determined that the toner replenishment abnormality has occurred.

  Preferably, when a predetermined period has elapsed since the previous image formation, the determination unit supplies toner until the cumulative value of the number of sheets on which the image is formed after the lapse of the predetermined period exceeds a predetermined value. It is not judged that an abnormality has occurred.

  Preferably, the determination unit performs the determination without using the number of dots calculated by the first calculation unit during a period in which toner supply by the supply unit is prohibited.

  Preferably, the image forming apparatus further includes a switching unit that switches a control mode of the image forming apparatus based on the number of dots of the image calculated by the first calculating unit and the replenishment time acquired by the acquiring unit.

  Preferably, the switching unit switches whether to execute the image forming operation based on the number of dots of the image calculated by the first calculating unit and the replenishment time acquired by the acquiring unit.

  Preferably, the image forming apparatus further includes a notification unit that notifies the user of the fact when the determination unit determines that the toner supply abnormality has occurred.

  Preferably, the notification unit changes a user to be notified based on the number of dots of the image calculated by the first calculation unit and the replenishment time acquired by the acquisition unit.

  Preferably, the image forming apparatus includes a switching unit that switches the control mode of the image forming apparatus based on the number of dots of the image calculated by the first calculating unit and the replenishment time acquired by the acquiring unit, and a toner that is determined by the determining unit. When it is determined that a replenishment abnormality has occurred, notification means for notifying the user is further provided, and when the increase in replenishment time with respect to the number of dots in the image is equal to or greater than a first predetermined value, notification means Notifies the first user, and the switching means can execute the image forming operation, and the increase in the replenishment time with respect to the number of dots of the image is greater than or equal to a second predetermined value greater than the first predetermined value. The notification means notifies the first user and the second user, and the switching means can execute the image forming operation, and the increase amount of the replenishment time with respect to the number of dots of the image is larger than the second predetermined value. When 3 is equal to or higher than the predetermined value, the notification means performs notification to the first user and the second user, and the switching means is impractical to image forming operation.

According to still another aspect of the present invention, a toner container, a developing device that receives supply of toner from the toner container, a detecting unit that detects information about the amount of toner in the developing unit, and a detection result of the detecting unit An image forming apparatus control method comprising a replenishing means for replenishing toner to a developing device, an acquisition step for obtaining a replenishment time during which toner is replenished by the replenishing means, and calculating the number of dots of the image to be formed. A first calculation step; a determination step for determining whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step; comprising a first calculation step, a number of dot images, calculates the average value of the number of dots a predetermined number of image, a predetermined number of sheets, toner by the detection means in the developing device It is not less than the number of sheets to be imaged while the toner from the site to be issued to the site where the toner is consumed to flow.
According to still another aspect of the present invention, a toner container, a developing device that receives supply of toner from the toner container, a detecting unit that detects information about the amount of toner in the developing unit, and a detection result of the detecting unit An image forming apparatus control method comprising a replenishing means for replenishing toner to a developing device, an acquisition step for obtaining a replenishment time during which toner is replenished by the replenishing means, and calculating the number of dots of the image to be formed. A first calculation step; a determination step for determining whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step; The acquisition step calculates an average value of the toner replenishment time for a predetermined number of sheets as the replenishment time, and the toner is detected by the detecting unit in the developing unit. It is not less than the number of sheets to be imaged while the toner to flow to the site to which the toner is consumed from the position.

According to still another aspect of the present invention, a toner container, a developing device that receives supply of toner from the toner container, a detecting unit that detects information about the amount of toner in the developing unit, and a detection result of the detecting unit The control program of the image forming apparatus including the replenishing unit for replenishing the toner to the developing unit obtains the replenishment time during which the toner is replenished by the replenishing unit, and calculates the number of dots of the image to be formed. A first calculation step; a determination step for determining whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step; the cause the computer to execute, the first calculation step, a number of dot images, calculates the average value of the number of dots a predetermined number of image, the predetermined number, the developing device smell It is not less than the number of sheets to be imaged while the toner to flow from the site where the toner is detected to the site where the toner is consumed by the detection means.
According to still another aspect of the present invention, a toner container, a developing device that receives supply of toner from the toner container, a detecting unit that detects information about the amount of toner in the developing unit, and a detection result of the detecting unit The control program of the image forming apparatus including the replenishing unit for replenishing the toner to the developing unit obtains the replenishment time during which the toner is replenished by the replenishing unit, and calculates the number of dots of the image to be formed. A first calculation step; a determination step for determining whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step; The acquisition step calculates the average value of the replenishment time for a predetermined number of toners as the replenishment time, and the predetermined number is detected by the developing device. It is not less than the number of sheets to be imaged during the fluidized toner from the site where more toner is detected to the site where the toner is consumed.

  According to these inventions, it is determined whether or not a toner replenishment abnormality has occurred based on the number of dots of the image calculated by the first calculating unit and the replenishment time acquired by the acquiring unit. Accordingly, an image forming apparatus, an image forming apparatus control method, and an image forming apparatus control program capable of determining earlier and more reliably that an abnormal state in which the toner replenishment amount is reduced have occurred. Can be provided.

1 is a side view showing an outline of a hardware configuration of an image forming apparatus according to one embodiment of the present invention. 2 is a block diagram illustrating a configuration of a control circuit of the image forming apparatus. FIG. 3 is a side view illustrating an internal configuration of a toner bottle. FIG. It is a longitudinal cross-sectional view of a preliminary stirring part. It is a figure which shows typically the structure of the developing device part of a cartridge. It is a figure which shows typically the part in which the cleaning member is provided among cartridges. 6 is a graph illustrating an example of a detection result of a toner sensor when there is a predetermined amount of toner. 6 is a graph illustrating an example of a detection result of a toner sensor when there is no predetermined amount of toner. 6 is a flowchart illustrating a basic operation of the image forming apparatus in a toner replenishment abnormality determination function. It is a figure explaining an example of a moving average method. 6 is a graph showing the relationship between the cumulative number of dots and the toner consumption rate and the transition of the replenishment time gradient with respect to the number of dots. 6 is a graph illustrating a toner supply amount before and after a toner replenishment abnormality occurs. It is a graph which shows the relationship between the toner consumption rate and the cumulative number of dots in various states. 6 is a graph showing the relationship between the cumulative number of dots and the toner consumption rate when including a long standing period and the transition of the slope of the replenishment time with respect to the number of dots.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described.

  The image forming apparatus is an MFP (Multi Function Peripheral) having a scanner function, a copying function, a printer function, a facsimile function, a data communication function, and a server function. The scanner function is a function for reading an image of a set original and storing it in an HDD (Hard Disk Drive) or the like. The copying function is a function of printing (printing) it on paper or the like. The function as a printer is a function for printing on a sheet based on an instruction received from an external terminal such as a PC. The facsimile function is a function for receiving facsimile data from an external facsimile machine or the like and storing it in an HDD or the like. The data communication function is a function for transmitting / receiving data to / from a connected external device. The server function is a function that allows a plurality of users to share data stored in the HDD or the like.

  [Embodiment]

  FIG. 1 is a side view showing an outline of a hardware configuration of an image forming apparatus 1 according to one embodiment of the present invention.

  In FIG. 1, as the image forming apparatus 1, only a portion that executes the print function is shown. The image forming apparatus 1 prints a color image by a so-called tandem method.

  The image forming apparatus 1 roughly includes an image forming unit and a transport unit that transports a sheet as a print medium. As shown in FIG. 1, the image forming unit includes an intermediate transfer belt 2, cartridges 28a, 28b, 28c, and 28d (hereinafter simply referred to as cartridge 28), and a toner bottle (an example of a toner container) 25a. , 25b, 25c, 25d (hereinafter simply referred to as toner bottle 25). The transport unit includes a storage unit 16, a paper feed roller 8, a manual paper feed roller 9, a timing roller 10, a secondary transfer roller 11, a pressure roller 12a, a heating roller 12b, a paper discharge roller 13, and a double-sided transport path 29. I have. In addition, the image forming apparatus 1 includes an engine unit 100 and a controller unit 200.

  The image forming apparatus 1 can print a color image by forming images of CMYK colors on paper. The cartridge 28a and the toner bottle 25a correspond to yellow (Y). The cartridge 28b and the toner bottle 25b correspond to magenta (M). The cartridge 28c and the toner bottle 25c correspond to cyan (C). The cartridge 28d and the toner bottle 25d correspond to black (K).

  The intermediate transfer belt 2 has an annular shape, is suspended by a plurality of rollers from the inside, and is disposed at a substantially central portion inside the image forming apparatus 1. The intermediate transfer belt 2 is connected to the main motor 18 and is rotated by the rotation drive of the main motor 18.

  The cartridges 28a, 28b, 28c, 28d are disposed along the intermediate transfer belt 2. In each of the cartridges 28a, 28b, 28c, and 28d, photosensitive members 3a, 3b, 3c, and 3d (hereinafter simply referred to as photosensitive member 3), developing devices 4a, 4b, 4c, and 4d (hereinafter simply referred to as developing). And charging devices 5a, 5b, 5c and 5d, and exposure devices 6a, 6b, 6c and 6d. The charging devices 5a, 5b, 5c and 5d charge the photoreceptors 3a, 3b, 3c and 3d. The exposure devices 6a, 6b, 6c and 6d expose image patterns on the charged photoreceptors 3a, 3b, 3c and 3d. The developing devices 4a, 4b, 4c, and 4d develop the image patterns formed on the photoreceptors 3a, 3b, 3c, and 3d with toner. At this time, the toner in the developing devices 4a, 4b, 4c, and 4d is consumed. The toner images formed on the photoreceptors 3a, 3b, 3c, and 3d are transferred to the intermediate transfer belt 2 so that the toner images of the respective colors overlap.

  In the developing devices 4a, 4b, 4c, and 4d, toner sensors (an example of detection means) 31a, 31b, 31c, and 31d (hereinafter, simply referred to as toner sensor 31 or sensor 31) for measuring the toner amount are used. Is arranged. Details of the sensor 31 will be described later.

  A cleaner 7 and a waste toner box 15 are provided around the intermediate transfer belt 2. The cleaner 7 is a blade member that comes into contact with the intermediate transfer belt 2, and separates residual toner remaining on the intermediate transfer belt 2 from the intermediate transfer belt 2 so that excess toner does not remain on the intermediate transfer belt 2. . The waste toner box 15 stores toner separated from the intermediate transfer belt 2.

  The toner bottles 25a, 25b, 25c, and 25d are disposed above the cartridges 28a, 28b, 28c, and 28d. The toner bottles 25a, 25b, 25c, and 25d incorporate and operate the stirring blades 26a, 26b, 26c, and 26d (hereinafter sometimes simply referred to as the stirring blades 26), thereby operating the cartridges 28a, 28b, and 28c. , 28d. Each color toner is supplied to the developing device 4.

  The toner bottles 25a, 25b, 25c, and 25d are driven by toner replenishing clutches 23a, 23b, 23c, and 23d (hereinafter simply referred to as toner replenishing clutch 23), respectively. These toner supply clutches 23a to 23d transmit the driving force of another driving source (not shown), whereby the stirring blades 26a to 26d rotate.

  The image forming unit is further provided with motors such as a color photoconductor motor 17, a main motor 18, a fixing motor 19, a color developing motor 20, and a developing motor 21. Among the cartridges 28, the developing mechanisms of the color cartridges 28a, 28b, and 28c are driven by the driving force of the developing motor 20. The developing mechanism of the monochrome cartridge 28 d is driven by the driving force of the developing motor 21. The color photoconductors 3 a, 3 b and 3 c are driven by a color photoconductor motor 17.

  In the transport unit, the storage unit 16 stores paper as a recording medium. The paper is fed one by one from the storage unit 16 by the paper feed roller 8. The fed paper is temporarily stopped by the timing roller 10 and sent to the secondary transfer roller 11 at a predetermined timing. Note that the image forming apparatus 1 can also perform manual sheet feeding. The manually fed paper is sent to the timing roller 10 by the manual paper feed roller 9.

  The secondary transfer roller 11 is provided so as to be paired with a roller that suspends the intermediate transfer belt 2 from the inside with the intermediate transfer belt 2 interposed therebetween. The secondary transfer roller 11 transfers the toner image transferred onto the intermediate transfer belt 2 onto the conveyed paper. A neutralizing cloth 30 is provided downstream of the secondary transfer roller 11 in the paper conveyance direction (upward in FIG. 1). The neutralizing cloth 30 is disposed to neutralize the paper that has passed through the secondary transfer roller 11.

  The paper feed roller 8, the timing roller 10, the secondary transfer roller 11, and the like are driven to rotate by a main motor 18, for example.

  The sheet on which the toner image is transferred is sent to a fixing roller 12 composed of a pressure roller 12a and a heating roller 12b. The fixing roller 12 pressurizes and heats the paper to fix the toner image on the paper. Thereafter, the sheet is discharged by a discharge roller 13. A fixing loop sensor 27 is disposed on the downstream side of the secondary transfer roller 11 on the sheet conveyance path. The fixing loop sensor 27 detects sagging of the paper and adjusts the paper conveyance speed.

  The image forming apparatus 1 is configured to be capable of duplex printing. When duplex printing is performed, a sheet on which an image is formed on one side is sent to the duplex conveyance path 29 by the paper discharge roller 13. The sheet is transported to the timing roller 10 via the duplex transport path 29 by the duplex path transport rollers 14 a and 14 b provided along the duplex transport path 29. The double-sided path conveyance rollers 14 a and 14 b are driven by a double-sided conveyance motor 22.

  FIG. 2 is a block diagram illustrating a configuration of the control circuit of the image forming apparatus 1.

  Referring to FIG. 2, the control circuit of image forming apparatus 1 is roughly divided into a controller unit 200 and one provided in engine unit 100. The controller unit 200 controls the overall operation of the image forming apparatus 1. The engine unit 100 is connected to the controller unit 200 and exchanges necessary information such as the number of dots and the number of prints with the controller unit 200.

  As shown in FIG. 2, the image forming apparatus 1 is provided with a display panel (an example of a notification unit) 210. The display panel 210 is a touch panel, for example, and is connected to the controller unit 200. The user can cause the controller unit 200 to control the image forming apparatus 1 to perform various operations by performing an operation input on the display panel 210. Further, the user can know the state of the image forming apparatus 1 by looking at the display content of the display panel 210.

  The engine unit 100 includes an apparatus control unit (an example of a replenishment unit, an example of an acquisition unit, a first calculation unit, a second calculation unit, an example of a determination unit, an example of a switching unit) 40, a main body-attached nonvolatile memory 60, And various loads 80 and the like. The various loads 80 include, for example, various motors 17 to 21 and a heater (not shown) for the fixing roller 12. The engine unit 100 may include a unit-attached non-volatile memory that is provided in a consumable such as each cartridge 28 and stores information related to the use history.

  The device control unit 40 has a CPU 50. The device control unit 40 includes a ROM (not shown), a RAM (not shown), and the like. The CPU 50 controls operations of the main body-attached nonvolatile memory 60, various loads 80, the cartridge 28, and the like.

  The main body-attached nonvolatile memory 60 is, for example, an EEPROM, and is used as a storage medium. The main body-attached nonvolatile memory 60 is connected to the CPU 50. The main body-attached nonvolatile memory 60 can store various information such as data measured and calculated by the CPU 50 and setting information of the image forming apparatus 1.

  In the present embodiment, a control program 61 is stored in the main body-attached nonvolatile memory 60. The CPU 50 executes the control operation of the engine unit 100 by reading the control program 61 from the nonvolatile memory 60 attached to the main body and executing it, for example.

  The main body-attached nonvolatile memory 60 is not limited to the EEPROM. As the main body-attached nonvolatile memory 60, an HDD (Hard Disk Drive) or the like may be provided instead of or in addition to EEPEOM. Further, the control program 61 is not necessarily stored in the main body-attached nonvolatile memory 60.

  [Explanation regarding toner supply operation]

  Next, a toner replenishing operation to the developing device 4 will be described. The toner replenishing operation is performed in the toner density control function. That is, when the amount of toner in the developing device 4 decreases due to printing, the toner stored in the toner bottle 25 of each color is supplied to the developing device 4. The toner replenishment is appropriately executed based on information on the toner concentration (toner amount) in the developing device 4 detected by the toner sensor 31. The toner replenishment is performed under the control of the device control unit 40. The toner supply may be periodically performed according to the number of printed sheets in addition to the detection result of the toner sensor 31.

  FIG. 3 is a side view illustrating the internal configuration of the toner bottle 25 (toner bottles 25a, 25b, 25c, and 25d).

  As shown in FIG. 3, the toner bottle 25 includes a toner storage unit 251, a preliminary stirring unit 252, and a buffer unit 253. The preliminary stirring unit 252 is provided with a toner level sensor 252z for detecting the amount of toner in the preliminary stirring unit 252.

  FIG. 4 is a longitudinal sectional view of the preliminary stirring unit 252.

  The preliminary stirring unit 252 includes a toner hopper 252 h for dropping the toner toward the cartridge 28. As shown in FIG. 4, a stirring blade 26 is provided in the toner hopper 252 h of the preliminary stirring unit 252. The toner hopper 252h rotates the stirring blade 26 by the driving force transmitted by the toner supply clutch. When the stirring blade 26 rotates, the toner in the toner storage unit 251 falls to the cartridge 28 via the toner hopper 252h. As a result, toner is supplied from the toner bottle 25 to the cartridge 28.

  FIG. 5 is a diagram schematically showing the configuration of the developing device 4 portion of the cartridge 28.

  With reference to FIG. 5, the developing device 4 is provided in a part of the cartridge 28. The space inside the developing device 4 is roughly divided into a storage unit 285, a stirring unit 286, and a toner buffer 287. The developing device 4 includes a toner supply port 280, a supply roller 282, a stirring member 283, a cleaning member 284, and the like.

  The toner replenishing port 280 is provided in the upper part of the cartridge 28 and serves as a toner inlet from the toner bottle 25. The toner supplied to the developing device 4 through the toner supply port 280 is temporarily stored in the storage unit 285. The supply roller 282 and the stirring member 283 are disposed in the longitudinal direction of the cartridge 28. The replenishing roller 282 is provided with blades for conveying toner. Accordingly, the toner in the storage unit 285 is conveyed to the stirring unit 286 as the replenishing roller 282 rotates. The stirring member 283 is provided with blades for stirring the toner. As a result, the agitating member 283 rotates, whereby the toner is agitated and the toner moves in a direction opposite to the toner conveying direction by the replenishing roller 282. In this way, the toner is conveyed in the direction indicated by the arrow in FIG. Part of the toner in the stirring unit 286 is also held in the toner buffer 287. The agitated toner is supplied to the surface of a developing roller (not shown) by rotation of a supply roller (not shown).

  In the present embodiment, the storage unit 285 is provided with a sensor 31 for detecting the presence or absence of toner in the storage unit 285. The sensor 31 includes a light emitting element and a light receiving element. The sensor 31 detects whether or not a predetermined amount of toner is in the storage unit 285, that is, in the developing device 4, based on the light intensity detected by the light receiving element. In other words, the sensor 31 detects information regarding the toner amount in the developing device 4.

  For example, the sensor 31 is configured such that the light emitting element and the light receiving element face each other through a detection window 285z provided in the storage portion 285 portion. The sensor 31 is configured such that the detection light emitted from the light emitting element passes through the storage portion 285 and enters the light receiving element via the detection window 285z. In other words, the sensor 31 is of a transmissive type, and the apparatus control unit 40 can detect information about the presence or absence of toner in the developing device 4 using the transmissive sensor 31.

  FIG. 6 is a diagram schematically showing a portion of the cartridge 28 where the cleaning member 284 is provided.

  As shown in FIG. 6, the cleaning of the detection window 285 z in the sensor 31 is performed by the cleaning member 284. The cleaning member 284 reciprocates in the direction of a double arrow in FIG. 6 using, for example, the developing motors 20 and 21 as a driving source. The cleaning member 284 wipes the detection window 285z portion, for example, every 2 seconds. As the cleaning member 284 reciprocates the detection window 285z in this way, the detection window 285z is cleaned, and the toner density is appropriately detected by the sensor 31.

  As shown in FIG. 6, when the toner T is in the developing device 4 by a predetermined amount, the detection light of the sensor 31 that passes through the storage portion 285 through the detection window 285 z is blocked by the toner T. Accordingly, the sensor 31 can detect that the toner T is present in a certain amount in the developing device 4.

  Here, when the detection window 285z is wiped by the cleaning member 284, the cleaning member 284 may block the detection light of the sensor 31. At this time, even if the detection result of the sensor 31 does not actually have a predetermined amount of toner T in the storage unit 285 (when the sensor 31 does not detect the presence of the predetermined amount of toner T), Therefore, the detection result is the same as that when the toner T is present.

  FIG. 7 is a graph showing an example of the detection result of the toner sensor 31 when there is a predetermined amount of toner. FIG. 8 is a graph showing an example of a detection result of the toner sensor 31 when there is no predetermined amount of toner.

  7 and 8, the horizontal axis indicates the stirring time of the toner in the developing device 4, that is, the passage of time, and the vertical axis indicates the output voltage (detection voltage) of the sensor 31. As shown in FIG. 7, when a predetermined amount of toner is present in the developing device 4, the detection light of the sensor 31 is blocked by the toner. Therefore, the detection voltage is always relatively high (for example, about 3V). On the other hand, as shown in FIG. 8, when there is no predetermined amount of toner in the developing device 4, the detection light of the sensor 31 is not blocked by the toner, so that the detection voltage is normally in a relatively low state ( For example, the state is about 0V). Here, in FIG. 8, the detected voltage is a value of about 3 V, which is about the same as the voltage in a state where a predetermined amount of toner is present, in the period where the stirring time (horizontal axis) is about 0.5 seconds to 1.1 seconds. Have taken. This is because the detection light of the sensor 31 is blocked by the cleaning member 284 during this period. Therefore, after this period, the detection voltage returns to a relatively low state.

  The apparatus control unit 40 executes a toner replenishing operation based on the toner density in the developing device 4 detected by the sensor 31 as described above. When it is detected by the sensor 31 that there is not a predetermined amount of toner in the developing device 4, that is, when it is detected that the toner is insufficient (or toner is likely to be insufficient) in the developing device 4. For example, the device control unit 40 drives the toner bottle 25 to perform a toner supply operation. As a result, toner is supplied from the toner bottle 25 to the developing device 4 and the toner in the developing device 4 is replenished.

  Note that, as described above, even when the toner is insufficient in the developing device 4, the detection result of the sensor 31 may be the same as when the predetermined amount of toner is temporarily in the developing device 4. However, during normal operation, such an event does not occur constantly. Therefore, when it is detected that the toner is insufficient, the toner in the developing device 4 is properly supplied by performing the toner replenishment operation. Will be replenished.

  In the image forming apparatus 1, the apparatus control unit 40 calculates the amount of toner consumed by the image forming operation. The calculation of the consumption amount is performed, for example, when an image formation instruction is issued from an external device such as a personal computer. At this time, the apparatus control unit 40 calculates the number of dots for each color of the image (image to be formed) that is the target of image formation during the image forming operation. Then, the device control unit 40 calculates toner consumption for each color based on the calculated number of dots for each color.

  The image forming apparatus 1 may perform the toner supply operation based on the toner consumption calculated in this way. For example, when an image formation instruction is given from an external device, the apparatus control unit 40 may perform a toner replenishing operation so that the developing unit 4 is replenished with the calculated consumption amount of toner.

  [Description of Toner Supply Abnormality Judgment Function]

  The apparatus control unit 40 of the image forming apparatus 1 determines whether an abnormality (toner replenishment abnormality) has occurred regarding the toner replenishment operation (toner replenishment abnormality determination). That is, when the toner replenishment abnormality has occurred, the device control unit 40 detects this. The toner replenishment abnormality determination is performed for each color.

  In the present embodiment, the apparatus control unit 40 basically performs a toner replenishment abnormality determination as follows. That is, when the toner replenishing operation is performed, the device control unit 40 measures and acquires the time (hereinafter referred to as replenishment time) when the toner is replenished. Thereby, the amount of toner that should have been replenished can be grasped. Further, the device control unit 40 calculates the number of dots of the image to be formed. This is done, for example, as described above. The apparatus control unit 40 makes a toner replenishment abnormality determination based on the relationship between the calculated dot number of the image and the replenishment time of the toner replenishment operation. More specifically, for example, the apparatus control unit 40 calculates an increase amount (slope) of the replenishment time with respect to the number of dots of the image, and performs a toner replenishment abnormality determination if the increase amount is equal to or greater than a predetermined value.

  Here, the apparatus control unit 40 calculates an average value of the number of dots of the image for a predetermined number of sheets, and uses this as the “number of dots of the image” in the above description to make a toner replenishment abnormality determination. Further, the apparatus control unit 40 calculates the average value of the toner replenishment time for a predetermined number of sheets, and uses this as the “replenishment time” in the above description to determine toner replenishment abnormality. That is, the apparatus control unit 40 calculates the inclination (increase amount) of the average of the toner replenishment time with respect to the average of the number of consumed dots for each sheet. If the calculated inclination is equal to or greater than a predetermined value, it is determined that a toner replenishment abnormality has occurred.

  The average value of the number of dots and the replenishment time is equal to or more than the number of sheets printed while the toner flows from the portion where the toner is detected by the sensor 31 to the portion where the toner is consumed in the developing device 4. Is calculated using the predetermined number of pieces of data. That is, referring to FIG. 5, the toner in the storage unit 285 in which the toner is detected by the sensor 31 in the developing device flows to the stirring unit 286 by the supply roller 282 and is conveyed to about six sheets. Assume that it takes time to print. At this time, the average values of the number of dots and the replenishment time are calculated using data for six or more sheets such as 7, 8 sheets, for example.

  FIG. 9 is a flowchart showing the basic operation of the image forming apparatus 1 in the toner replenishment abnormality determination function.

  As shown in FIG. 9, in step S11, the apparatus control unit 40 starts printing one sheet (printing start).

  In step S12, the apparatus control unit 40 detects that printing of one sheet has been completed (printing is completed).

  In step S13, the apparatus control unit 40 calculates an average value of the number of dots. That is, after calculating the number of dots of the image formed at that time, the average value of the number of dots of the image is calculated together with the number of dots of the image formed in the past.

  In step S14, the apparatus control unit 40 calculates an average value of the replenishment time. That is, the replenishment time of the toner replenishment operation performed at that time is acquired, and the average value of the replenishment time is calculated together with the past replenishment time.

  In step S15, the apparatus control unit 40 calculates the increase amount (slope) of the replenishment time with respect to the number of dots. A specific method for calculating the inclination will be described later.

  In step S16, the apparatus control unit 40 determines whether or not the calculated inclination is equal to or greater than a predetermined value. Here, the predetermined value may be set in consideration of, for example, a replenishment time that may be necessary when a toner replenishment abnormality occurs. If the inclination is not greater than or equal to the predetermined value in step S16, the process returns to step S11, and another sheet is printed.

  When the inclination is equal to or greater than the predetermined value in step S16, in step S17, the apparatus control unit 40 determines that a toner replenishment abnormality has occurred.

  In step S <b> 18, the apparatus control unit 40 performs toner supply abnormality display. This notifies the user that a toner replenishment abnormality has occurred. When receiving the notification, the user can take various actions accordingly.

  During the above process, the process of calculating the average number of dots in step S13 and the process of calculating the average value of replenishment time in step S14 are performed by the following moving average method, for example. The moving average method is a method of averaging time series data.

  FIG. 10 is a diagram for explaining an example of the moving average method.

  As shown in FIG. 10, the device control unit 40 always calculates the average value of the number of dots and the replenishment time by calculating the average value for, for example, eight data (data1 to data8) with the new acquired time. To do. When new data (new data) of the number of dots and replenishment time is acquired, the oldest data (old data) among the data entered when calculating the previous average value is discarded. Thereby, the average value can be calculated for the eight data including the data (new data) acquired at this time, and the recent average value can be calculated efficiently.

  During the above processing, the calculation of the slope in step S15 is performed by the following calculation method, for example.

  That is, in the apparatus control unit 40, an average value of the replenishment time (average toner replenishment time; unit ms) and an average value of the number of dots of the image to be printed (for example, calculated with 1000 full dots in the A4 area). Has been obtained. Here, the inclination of the replenishment time with respect to the number of dots, that is, the increase amount is obtained as (average toner replenishment time) / (average dot number). In other words, the increase in the replenishment time with respect to the number of dots is the quotient obtained by dividing the replenishment time (in this embodiment, the average value of replenishment time) by the number of dots in the image (in this embodiment, the average value of the number of dots). As obtained.

  In the present embodiment, for example, when the inclination is 120 (ms / dot), the apparatus control unit 40 determines that a toner replenishment abnormality has occurred.

  For example, it is assumed that the average toner replenishment time is 3 seconds (3000 ms) and the average number of dots is 20. At this time, the device control unit 40 calculates the inclination as follows.

  3000 ms (average toner replenishment time) / 20 (average number of dots) = 150 (slope)

  In this case, since the obtained inclination is larger than the predetermined value 120, the apparatus control unit 40 determines that a toner replenishment abnormality has occurred.

  FIG. 11 is a graph showing the relationship between the cumulative number of dots and the toner consumption rate and the transition of the replenishment time gradient with respect to the number of dots.

  In FIG. 11, the vertical axis represents the toner consumption rate or the slope of the toner consumption rate relative to the cumulative number of dots. The toner consumption rate corresponds to, for example, the sum of toner replenishment times. That is, the toner consumption rate is calculated from the accumulated replenishment time, and the toner is replenished according to the detection level of the sensor 31. For example, the apparatus control unit 40 has a table for calculating the toner consumption rate from the replenishment time, and the toner consumption rate corresponding to the replenishment time is thereby calculated. The horizontal axis in FIG. 11 is the cumulative number of dots. As the cumulative number of dots increases, the toner consumption rate gradually increases. At each time point (cumulative dot number), the slope of the replenishment time with respect to the number of dots is shown such that the lower part of the graph is zero and the upper part has a larger slope. In FIG. 11, the scale on the right vertical axis indicates the value of the slope.

  As shown in FIG. 11, when no toner replenishment abnormality has occurred, the toner consumption rate gradually increases as the cumulative number of dots increases. At this time, the slope of the replenishment time with respect to the number of dots does not change much. Here, when the toner replenishment abnormality occurs, the amount of increase in the toner consumption rate increases, and the toner consumption rate increases rapidly (the part marked with a balloon in FIG. 11). That is, the slope of the replenishment time with respect to the number of dots increases rapidly and exceeds the predetermined value (120). As a result, the apparatus control unit 40 determines that a toner replenishment abnormality has occurred.

  FIG. 12 is a graph illustrating the toner supply amount before and after the toner replenishment abnormality occurs. FIG. 13 is a graph showing the relationship between the toner consumption rate and the cumulative number of dots in various states.

  In FIG. 12, the horizontal axis represents the cumulative number of dots, and the vertical axis represents the toner supply amount per unit time (for example, 1 second). As shown in FIG. 12, a portion surrounded by a two-dot chain line A on the left side of the substantially central portion of the horizontal axis indicates a toner supply amount in a normal state in which no abnormality has occurred. On the other hand, a portion surrounded by a two-dot chain line B on the right side of the substantially central portion of the horizontal axis indicates a toner supply amount when a toner replenishment abnormality occurs. The broken lines shown in FIG. 12 are averaged values of the toner supply amount.

  In FIG. 13, the horizontal axis indicates the cumulative number of dots, and the vertical axis indicates the toner consumption rate. FIG. 13 shows data indicating the relationship between the toner consumption rate and the cumulative number of dots for each of the four developing devices 4 (for example, the developing devices 4 for CMYK colors). Of the data for the four developing devices 4 shown in FIG. 13, the data noted by the balloon indicates a state in which a toner replenishment abnormality has occurred in the middle of printing. The data for the other three developing devices 4 indicates a normal state in which no toner replenishment abnormality has occurred during printing.

  Here, the toner replenishment abnormality occurs, for example, when a mylar provided in the toner replenishing port 280 between the toner bottle 25 and the developing device 4 is turned over unscheduled. The example of the toner replenishment abnormality shown in FIG. 13 and the like is a case where such a Mylar turn is generated. In addition to turning over mylar, the toner supply abnormality also occurs when, for example, the stirring blade 26 such as the toner hopper 252h is partially damaged or a part of the toner supply path is blocked by a shutter or the like. To do.

  As shown in FIG. 12, it can be seen that, for example, when Mylar turning occurs, the toner supply amount is lower than the normal toner supply amount (the portion surrounded by the two-dot chain line A) (enclosed by the two-dot chain line B). Part). For this reason, when the Mylar turn is generated, the toner consumption rate increases rapidly as shown in FIG. In other words, when Mylar turning occurs, the slope of the replenishment time with respect to the number of dots increases rapidly, and the toner consumption increases with respect to the cumulative number of dots as compared with the case where no abnormality has occurred. This is because it is necessary to replenish toner for a longer time in order to replenish the same amount of toner as usual when Mylar is turning over.

  As described above, in this embodiment, the toner replenishment abnormality determination is performed based on the number of dots of the image and the toner replenishment time. The toner replenishment abnormality determination is made based on whether or not the slope (increase amount) of the replenishment time with respect to the number of dots of the image is larger than a predetermined value. Therefore, when a toner replenishment abnormality that cannot be detected in the past has occurred, such that the amount of toner replenishment is slightly smaller than normal, it is determined that the toner replenishment abnormality has occurred reliably. .

  In this embodiment, the average value of the number of dots and the replenishment time is calculated, and toner replenishment abnormality determination is performed based on each average value. Therefore, the determination result of the toner replenishment abnormality determination can be stabilized. For example, even when data that can be determined to temporarily cause the toner replenishment abnormality has been obtained, the toner replenishment abnormality is erroneously detected. It is no longer determined that it has occurred.

  In the present embodiment, as shown in FIG. 5, the position of the sensor 31 that detects the presence or absence of toner in the developing device 4 is separated from the location where the toner is actually consumed in the developing device 4. Therefore, it takes time until the influence of toner consumption reaches the state of the point where the sensor 31 is provided. That is, it takes time until the sensor 31 detects that the toner has been consumed, which may deviate from the timing at which the toner supply is consumed. However, in the present embodiment, as described above, even if the timing of toner replenishment and consumption deviates, the average value of data for a predetermined period is used to mitigate the influence of the deviation and then toner replenishment. Abnormality judgment can be made. Therefore, it is possible to more reliably prevent the determination result of the toner replenishment abnormality determination from being incorrect.

  [Explanation when toner replenishment abnormality judgment is not performed]

  Here, the apparatus control unit 40 does not perform toner replenishment abnormality determination in the following cases (1) to (3). This prevents erroneous determination that a toner replenishment abnormality has occurred. It should be noted that only a part of the following (1) to (3) may be adopted as a condition that the toner replenishment abnormality determination is not performed.

  (1) For example, the apparatus control unit 40 does not make a toner replenishment abnormality determination in the following cases when a predetermined period has elapsed since the previous printing was performed. Therefore, even when other conditions for determining toner supply abnormality as described above are satisfied, for example, printing is performed for a long period of time (more than a predetermined period) since the previous printing was performed. If it is left unattended, it may not be determined that a toner replenishment abnormality has occurred. As the predetermined period, for example, a period required for the toner to settle in the developing device 4 may be set as appropriate.

  In other words, when the predetermined period has elapsed since the previous printing, the device control unit 40 causes the toner replenishment abnormality until the cumulative value of the replenishment time acquired after the predetermined period elapses exceeds a predetermined value. It is not judged that has occurred. In addition, when the predetermined period has elapsed, the apparatus control unit 40 does not determine that the toner replenishment abnormality has occurred until the cumulative value of the number of dots calculated after the predetermined period has elapsed is equal to or greater than the predetermined value. In addition, when the predetermined period has elapsed, the apparatus control unit 40 does not determine that the toner replenishment abnormality has occurred until the cumulative value of the number of printed sheets after the predetermined period has exceeded a predetermined value. Note that the apparatus control unit 40 may use a condition for determining whether or not toner replenishment is abnormal that only one or two of these three conditions are satisfied when a predetermined time has elapsed.

  FIG. 14 is a graph showing the relationship between the cumulative number of dots and the toner consumption rate and the change in the replenishment time gradient with respect to the number of dots when a long standing period is included.

  In FIG. 14, the vertical axis represents the toner consumption rate or the slope of the toner consumption rate with respect to the cumulative number of dots. The horizontal axis is the cumulative number of dots. As the cumulative number of dots increases, the toner consumption rate gradually increases. At each time point (cumulative dot number), the slope of the toner consumption rate with respect to the cumulative dot number is shown so that the lower part of the graph is zero and the upper part is larger. In the example shown in FIG. 14, there is a period in which printing is not performed for a predetermined period or more before and after the balloon indicated as “after being left for a long time” (however, the horizontal axis is not time but accumulated. Since it is the number of dots, the toner consumption rate is always displayed to increase gradually.)

  As shown in FIG. 14, the slope of the toner consumption rate with respect to the cumulative number of dots is greater after long-term storage than before long-term storage. This is because, for example, the toner in the developing device 4 may settle due to being left for a long time, and the sensor 31 may detect that there is no predetermined amount of toner. In such a state, when the toner replenishing operation is performed, the toner is replenished even if the toner is not consumed, and the toner replenishment abnormality may be erroneously detected.

  However, in the present embodiment, the apparatus control unit 40 does not make a toner replenishment abnormality determination unless the above condition is satisfied when a predetermined period has elapsed since the previous printing (toner replenishment abnormality). Is not considered to have occurred.) As a result, the toner replenishment abnormality has occurred in a state where it is considered that the toner has been agitated and settled according to the cumulative number of dots, the cumulative toner replenishment time, or the number of printed sheets even after being left for a long time. It is determined whether or not. Accordingly, it is possible to appropriately prevent the toner replenishment abnormality from being erroneously detected.

  (2) For example, when the toner bottle 25 is replaced after the occurrence of a toner empty state in which toner is insufficient, the apparatus control unit 40 does not determine that there is a toner replenishment abnormality in the following case. Here, the toner empty state means, for example, a state in which the amount of toner is not recovered even when the toner in the developing device 4 is low and the toner supply operation is performed. That is, when the amount of toner in the toner bottle 25 decreases and toner supply from the toner bottle 25 is not performed, the toner empty state is entered.

  The device control unit 40 does not determine that a toner replenishment abnormality has occurred until the accumulated value of the calculated number of dots becomes equal to or greater than a predetermined value after the toner empty state has occurred and the toner bottle 25 has been replaced. Further, the apparatus control unit 40 does not determine that the toner replenishment abnormality has occurred until the accumulated value of the replenishment time becomes equal to or greater than a predetermined value after the toner bottle 25 is replaced after the toner empty state is generated. Further, the apparatus control unit 40 does not determine that the toner replenishment abnormality has occurred until the accumulated value of the number of printed sheets is equal to or greater than a predetermined value after the toner bottle 25 is replaced after the toner empty state is generated. Note that the apparatus control unit 40 may use a condition for determining whether or not toner replenishment is abnormal that only one or two of these three conditions are satisfied when a predetermined time has elapsed.

  Since the toner in the developing device 4 is low in the toner empty state, when the toner bottle 25 is replaced, the toner replenishing operation is performed without toner consumption until the toner amount in the developing device 4 is recovered. Then, the gradient of the replenishment time with respect to the number of dots becomes very large, and it is erroneously determined that a toner replenishment abnormality has occurred. On the other hand, in the present embodiment, the determination of abnormality in toner replenishment is delayed according to the cumulative number of dots, the cumulative toner replenishment time, or the number of printed sheets, so that erroneous determination of abnormality in toner replenishment can be prevented.

  (3) For example, the device control unit 40 does not determine that the toner replenishment is abnormal in the following case. This is because the state is considered to be close to the toner empty state.

  That is, the device control unit 40 supplies toner when the cumulative value of the number of dots is equal to or greater than the predetermined value, when the cumulative value of the replenishment time is equal to or greater than the predetermined value, or when the cumulative value of the number of printed sheets is equal to or greater than the predetermined value. It is not judged that an abnormality has occurred. Note that the apparatus control unit 40 may use a condition for determining whether or not toner replenishment is abnormal that only one or two of these three conditions are satisfied when a predetermined time has elapsed.

  Here, when the various accumulated values are equal to or greater than the predetermined value as described above, when the slope of the replenishment time with respect to the number of dots is equal to or greater than the predetermined value, the apparatus control unit 40 determines that the toner is in an empty state. You may make it do. When the toner empty state is imminent, the amount of toner in the toner bottle 25 is small, and the amount of toner supplied per unit time is reduced. Then, the gradient of the replenishment time with respect to the number of dots becomes large, and this state may be erroneously determined as a toner replenishment abnormality. In this embodiment, in such a case, the toner replenishment abnormality determination is not performed, so that an erroneous determination can be prevented.

  It should be noted that various accumulated values under these conditions may be those when the same toner bottle is continuously used. In other words, when the toner bottle is replaced with a new one, it is not considered that the toner is in a nearly empty state, so the accumulated value may be reset and newly accumulated again.

  In the present embodiment, the apparatus control unit 40 provides a toner supply prohibition period during which a toner supply operation is not performed when a predetermined operation is performed. For example, a period during which the stabilization operation is performed is a toner replenishment prohibition period. This is because, if toner replenishment is performed during stabilization, adverse effects such as a change in the color of the formed image may occur. In such a toner supply prohibition period, even if toner is consumed, the toner supply operation is not performed. Therefore, the apparatus control unit 40 calculates the slope of the replenishment time with respect to the number of dots without considering the number of dots calculated during the toner replenishment prohibition period even when the toner replenishment abnormality determination is performed. Then, the toner replenishment abnormality determination is performed.

  If the number of dots consumed while toner is consumed but no toner replenishment operation is used in the calculation of the gradient of the replenishment time relative to the number of dots, the balance between the number of dots and the replenishment time will be lost, and toner replenishment will occur. An incorrect judgment may be made about the abnormality. Therefore, the toner supply abnormality determination can be made more accurately by not using the toner consumption data during the toner supply prohibition period in the inclination calculation.

  [Description of operation related to toner supply abnormality determination]

  When it is determined that a toner replenishment abnormality has occurred, the device control unit 40 notifies the user that an abnormality has occurred in the toner replenishment operation (notification operation). The notification to the user is performed, for example, by displaying a notification item on the display panel 210 or the like (toner supply abnormality display), but is not limited thereto.

  Further, the apparatus control unit 40 determines whether or not to execute the image forming operation (an example of an operation mode of the image forming apparatus 1) based on the number of dots of the image and the replenishment time, such as when a toner replenishment abnormality has occurred. Switching (switching operation).

  In the present embodiment, these notification operations and switching operations are performed as follows, for example, according to the gradient (increase amount) of the replenishment time with respect to the number of dots. In the notification operation, the user to be notified is changed according to the calculated inclination.

  That is, the first case where the slope of the replenishment time with respect to the number of dots of the image is equal to or greater than the first predetermined value A and the second where the slope is equal to or greater than the second predetermined value B greater than the first predetermined value A. The combination of the user who is the notification target in the notification operation and whether or not the image forming operation can be executed is switched between the case where the inclination is equal to or greater than the third predetermined value C greater than the second predetermined value B. It is done.

  In the first case, the device control unit 40 notifies the first user. At this time, the apparatus control unit 40 maintains an image forming operation in an executable state. In the first case, since the degree of abnormality is relatively minor, for example, notification is performed only to a user (so-called serviceman or the like) engaged in maintenance of the image forming apparatus 1 as the first user. Further, the image forming operation is kept executable.

  In the second case, the device control unit 40 notifies the first user and the second user. At this time, the apparatus control unit 40 keeps the image forming operation executable. In the second case, the degree of abnormality is greater than in the first case. For this reason, in addition to the first user, for example, a user who actually uses the image forming apparatus 1 as a second user is notified. Further, the image forming operation is kept executable.

  In the third case, the device control unit 40 notifies the first user and the second user. At this time, the apparatus control unit 40 switches the image forming operation to be unexecutable. In the third case, the degree of considerable abnormality is larger in the first case than in the second case. Therefore, many users are notified and the image forming operation cannot be executed.

  The apparatus control unit 40 performs control using the three threshold values (first predetermined value A, second predetermined value B, and third predetermined value C) in this way, for example, as described below. It is possible to execute the corresponding operation.

  That is, even a small toner replenishment abnormality needs to be resolved, so it is desirable to detect it as early as possible. For example, toner may spill into the machine even if the degree of mylar turning is low. However, if the threshold value is lowered so that the toner supply abnormality can be determined at an early stage, there is a high possibility that the toner supply abnormality is erroneously determined. The toner supply amount may change depending on the humidity, temperature, and the like.

  In contrast, in the present embodiment, in such a case as described above, for example, not only a general user but also a user engaged in maintenance of the image forming apparatus 1 is notified of abnormality information, and the image forming apparatus 1 itself Keeps the image forming operation feasible.

  On the other hand, when the inclination reaches the second predetermined value B, it is considered that a relatively large toner replenishment abnormality has occurred, although not so much as to stop image formation. Therefore, the user is notified that the toner replenishment abnormality has occurred and asked for confirmation.

  Further, when the inclination reaches a third predetermined value C that is larger than the second predetermined value B, it is considered that a considerably large toner replenishment abnormality has occurred. In such a case, by notifying the general user that an abnormality has occurred while not being able to form an image, the user can refrain from using the image forming apparatus 1 or check the status. I get it. In such a state, it is conceivable that the toner is hardly replenished. Therefore, if the image forming operation is performed as it is, the image may be blurred or a defect such as packing in the toner bottle 25 may occur. There is sex.

  [Others]

  The notification to the user is not limited to that performed by displaying information on the display panel. For example, the notification may be performed by emitting a voice or the like, or the notification may be performed by transmitting an e-mail or other message to the user via a network or the like.

  The apparatus control unit is not limited to whether or not the image forming operation can be performed, and may switch various control modes of the image forming apparatus based on the number of dots of the image and the replenishment time. For example, one of a plurality of control modes may be selected according to the inclination of the replenishment time with respect to the number of dots and applied to the control of the image forming apparatus.

  When the toner replenishment abnormality determination performed by the apparatus control unit is performed, the determination is made based on the characteristic portion in the above-described embodiment (for example, the determination based on the average value of the number of dots and the replenishment time, the calculation method of the average value, or the toner replenishment) It is not always necessary to include all elements of the prohibition period data). In addition, the toner replenishment abnormality determination may be performed by appropriately combining any of the individual elements that are characteristic portions.

  The image forming apparatus may be a monochrome / color copying machine, a printer, a facsimile machine, or a multifunction machine (MFP) thereof.

  The hardware configuration of the image forming apparatus is not limited to the above. For example, another type of sensor may be used as the toner sensor. Further, information relating to the amount of toner in the developing device may be detected by a method of detecting the weight of the toner bottle.

  The processing in the above embodiment may be performed by software or by using a hardware circuit.

  A program for executing the processing in the above-described embodiment can be provided, or the program can be recorded on a recording medium such as a CD-ROM, a flexible disk, a hard disk, a ROM, a RAM, or a memory card and provided to the user. It may be. The program may be downloaded to the apparatus via a communication line such as the Internet. The processing described in the text in the above flowchart is executed by the CPU according to the program.

  The above embodiment should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1 Image forming apparatus 4 (4a, 4b, 4c, 4d) Developer 25 (25a, 25b, 25c, 25d) Toner bottle (an example of a toner container)
28 (28a, 28b, 28c, 28d) Cartridge 31 (31a, 31b, 31c, 31d) Toner sensor (an example of detection means)
40 device control unit 50 control unit 61 control program 210 display panel (an example of notification means)

Claims (24)

A toner container;
A developing device that receives supply of toner from the toner container;
Detecting means for detecting information on the toner amount in the developing unit;
Replenishment means for replenishing toner to the developing device according to the detection result of the detection means;
Obtaining means for obtaining a replenishment time during which toner is replenished by the replenishing means;
First calculating means for calculating the number of dots of an image to be formed;
Determining means for determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated by the first calculating means and the replenishment time acquired by the acquiring means;
The first calculation means calculates an average value of the number of dots of a predetermined number of images as the number of dots of the image,
The predetermined number of sheets is an image forming apparatus that is equal to or more than the number of sheets on which an image is formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed.   A toner container;
  A developing device that receives supply of toner from the toner container;
  Detecting means for detecting information on the toner amount in the developing unit;
  Replenishment means for replenishing toner to the developing device according to the detection result of the detection means;
  Obtaining means for obtaining a replenishment time during which toner is replenished by the replenishing means;
  First calculating means for calculating the number of dots of an image to be formed;
  Determining means for determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated by the first calculating means and the replenishment time acquired by the acquiring means;
  The acquisition means calculates an average value of replenishment times for a predetermined number of toners as the replenishment time,
  The predetermined number of sheets is an image forming apparatus that is equal to or more than the number of sheets on which an image is formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed. The image forming apparatus according to claim 2 , wherein the first calculation unit calculates an average value of the number of dots of a predetermined number of images as the number of dots of the image. The determination means includes
Second calculating means for calculating an increase amount of the replenishment time relative to the number of dots of the image based on the number of dots of the image calculated by the first calculating means and the replenishment time acquired by the acquiring means; Prepared,
When increased amount calculated by said second calculating means is equal to or greater than a predetermined value, it is determined that the toner supply abnormality has occurred, the image forming apparatus according to any one of claims 1 to 3. When the toner container is replaced after the occurrence of a toner empty state in which toner is insufficient,
The determination means does not determine that a toner replenishment abnormality has occurred after the replacement of the toner container until the cumulative value of the number of dots calculated by the first calculation means exceeds a predetermined value. Item 5. The image forming apparatus according to any one of Items 1 to 4 . When the toner container is replaced after the occurrence of a toner empty state in which toner is insufficient,
The determination unit does not determine that a toner replenishment abnormality has occurred until the accumulated value of the replenishment time acquired by the acquisition unit becomes equal to or greater than a predetermined value after the toner container is replaced. the image forming apparatus according to any one of 5. When the toner container is replaced after the occurrence of a toner empty state in which toner is insufficient,
The judgment unit may, after replacement of the toner container, until the accumulated value of the number of sheets on which images are formed reaches a predetermined value or more, does not determine the toner supply abnormality has occurred, of claims 1-6 The image forming apparatus according to any one of the above. The determining means is equal to or greater than a predetermined value is the accumulated value of the number of dots calculated by said first calculating means, does not determine the toner supply abnormality has occurred, to any of claims 1 to 7 The image forming apparatus described. The image according to any one of claims 1 to 8 , wherein the determination unit does not determine that a toner replenishment abnormality has occurred if a cumulative value of the replenishment time acquired by the acquisition unit is greater than or equal to a predetermined value. Forming equipment. The judgment unit may, if the accumulated value of the number of sheets on which an image is formed is higher than a predetermined value, does not determine that the toner supply abnormality has occurred, the image forming apparatus according to any one of claims 1 to 9 . The determination unit determines that the toner is in a toner empty state when the increase rate of the replenishment time acquired by the acquisition unit with respect to the number of dots calculated by the first calculation unit is equal to or greater than a predetermined value. the image forming apparatus according to any one of claims 8 10. When a predetermined period has elapsed since the last image formation,
Said determination means until said predetermined cumulative value of the acquired replenishment time by the acquisition unit after a period is equal to or greater than a predetermined value, does not determine that the toner supply abnormality has occurred, from the claims 1 to 11 The image forming apparatus according to any one of the above. When a predetermined period has elapsed since the last image formation,
The determination unit does not determine that a toner replenishment abnormality has occurred until a cumulative value of the number of dots calculated by the first calculation unit exceeds a predetermined value after the predetermined period has elapsed. The image forming apparatus according to any one of 1 to 12 . When a predetermined period has elapsed since the last image formation,
The determining means, until the cumulative value of the number of sheets to be image formed after the elapse of the predetermined period is equal to or greater than a predetermined value, does not determine that the toner supply abnormality has occurred, of claims 1 to 13 The image forming apparatus according to any one of the above. The judgment unit, the number of dots calculated by said first calculating means in a period in which supply is prohibited of toner by said feeding means performs the determination without using, according to any of claims 1 to 14 Image forming apparatus. 16. The apparatus according to claim 1, further comprising a switching unit that switches a control mode of the image forming apparatus based on the number of dots of the image calculated by the first calculation unit and the replenishment time acquired by the acquisition unit. The image forming apparatus according to any one of the above. 17. The image according to claim 16 , wherein the switching unit switches whether to perform an image forming operation based on the number of dots of the image calculated by the first calculating unit and the replenishment time acquired by the acquiring unit. Forming equipment. When the toner supply abnormality is determined to have occurred by the determining means, further comprising a notification means for notifying the user, the image forming apparatus according to any one of claims 1-17. The notification unit, based on the dispense time obtained by the first dot number and the acquisition unit of the image calculated by the calculation means changes the user as a target of the notification, to claim 18 The image forming apparatus described. Switching means for switching the control mode of the image forming apparatus based on the number of dots of the image calculated by the first calculation means and the replenishment time acquired by the acquisition means;
A notification means for notifying the user when the determination means determines that a toner replenishment abnormality has occurred;
When the increase amount of the replenishment time with respect to the number of dots of the image is equal to or greater than a first predetermined value, the notification unit notifies the first user of the notification, and the switching unit can execute an image forming operation. ,
When the increase amount of the replenishment time with respect to the number of dots of the image is equal to or greater than a second predetermined value that is greater than the first predetermined value, the notification means notifies the first user and the second user of the notification. And the switching means can execute an image forming operation,
When the increase amount of the replenishment time with respect to the number of dots of the image is equal to or greater than a third predetermined value that is greater than the second predetermined value, the notification means notifies the first user and the second user of the notification. It was carried out, and the switching means is impractical to image forming operation, the image forming apparatus according to any of claims 1 to 15. A toner container;
A developing device that receives supply of toner from the toner container;
Detecting means for detecting information on the toner amount in the developing unit;
A control method for an image forming apparatus, comprising: a replenishing unit that replenishes toner to the developing device according to a detection result of the detecting unit;
An acquisition step of acquiring a replenishment time in which toner is replenished by the replenishing means;
A first calculation step of calculating the number of dots of an image to be formed;
A determination step of determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step ;
The first calculating step calculates an average value of the number of dots of a predetermined number of images as the number of dots of the image,
The predetermined number of sheets is equal to or greater than the number of sheets on which images are formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed. Method.   A toner container;
  A developing device that receives supply of toner from the toner container;
  Detecting means for detecting information on the toner amount in the developing unit;
  A control method for an image forming apparatus, comprising: a replenishing unit that replenishes toner to the developing device according to a detection result of the detecting unit;
  An acquisition step of acquiring a replenishment time in which toner is replenished by the replenishing means;
  A first calculation step of calculating the number of dots of an image to be formed;
  A determination step of determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step;
  The obtaining step calculates an average value of toner supply times for a predetermined number of sheets as the supply time,
  The predetermined number of sheets is equal to or greater than the number of sheets on which images are formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed. Method. A toner container;
A developing device that receives supply of toner from the toner container;
Detecting means for detecting information on the toner amount in the developing unit;
A control program for an image forming apparatus, comprising: a replenishing unit that replenishes toner to the developing device according to a detection result of the detecting unit;
An acquisition step of acquiring a replenishment time in which toner is replenished by the replenishing means;
A first calculation step of calculating the number of dots of an image to be formed;
Causing the computer to execute a determination step of determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step. ,
The first calculating step calculates an average value of the number of dots of a predetermined number of images as the number of dots of the image,
The predetermined number of sheets is equal to or greater than the number of sheets on which images are formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed. program.   A toner container;
  A developing device that receives supply of toner from the toner container;
  Detecting means for detecting information on the toner amount in the developing unit;
  A control program for an image forming apparatus, comprising: a replenishing unit that replenishes toner to the developing device according to a detection result of the detecting unit;
  An acquisition step of acquiring a replenishment time in which toner is replenished by the replenishing means;
  A first calculation step of calculating the number of dots of an image to be formed;
  Causing the computer to execute a determination step of determining whether a toner replenishment abnormality has occurred based on the number of dots of the image calculated in the first calculation step and the replenishment time acquired in the acquisition step. ,
  The obtaining step calculates an average value of toner supply times for a predetermined number of sheets as the supply time,
  The predetermined number of sheets is equal to or greater than the number of sheets on which images are formed while the toner flows from a portion where toner is detected by the detection unit in the developing unit to a portion where the toner is consumed. program.

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