JP2016184111A - Image forming apparatus, control method, and computer program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To disclose a technology enabling counting of the number of rotations of a developing roller without arranging a dedicated rotation counter.SOLUTION: An image forming apparatus comprises: a photoreceptor; a motor; a driving part that drives the motor; a developing part including a developing roller that is rotated by a driving force output from the motor and develops an electrostatic latent image formed on the photoreceptor; a storage part; and a control part. The control part counts the number of rotations of the developing roller on the basis of a control signal corresponding to the number of rotations of the motor, the control signal provided from the motor to the driving part or provided from the driving part to the motor, and stores an accumulated value of the counted number of rotations of the developing roller in the storage part.SELECTED DRAWING: Figure 5

Description

  The technology disclosed in this specification relates to an image forming apparatus.

  In an electrophotographic image forming apparatus including a developing unit having a developing roller, the number of rotations of the developing roller is counted and, for example, the life of the developing unit is determined based on the counted value. In order to count the number of rotations of the developing roller, an image forming apparatus is known in which a number counter that directly counts the number of rotations of the developing roller is arranged via a gear mechanism connected to the developing roller (Patent Document 1). reference).

JP 2003-295595 A

  However, in the conventional image forming apparatus, since it is necessary to arrange a dedicated rotation counter in the gear mechanism in order to count the number of rotations of the developing roller, there is a problem that the configuration of the image forming apparatus becomes complicated, for example.

  The present specification discloses a technique capable of solving at least a part of the problems described above.

The technology disclosed in this specification can be implemented as the following forms.
The image forming apparatus disclosed in the present specification is rotated by a photosensitive member, a motor, a driving unit that drives the motor, and a driving force output from the motor, and an electrostatic latent image formed on the photosensitive member. A developing unit having a developing roller for developing an image, a storage unit, and a control unit, and the control unit is provided from the motor to the drive unit, or is provided from the drive unit to the motor. The number of rotations of the developing roller is counted based on a control signal corresponding to the unit number of rotations of the motor, and the accumulated value of the counted number of rotations of the developing roller is stored in the storage unit.

  The technology disclosed by this specification can be implemented in various forms. For example, the present invention can be realized in the form of a control method for the image forming apparatus, a computer program for realizing the function of the method or apparatus, a non-temporary recording medium on which the computer program is recorded, and the like.

FIG. 1 is a schematic diagram illustrating the overall configuration of the printer 1. FIG. 2 is a schematic diagram of the transmission unit 45. FIG. 3 is a block diagram illustrating a circuit configuration of the control unit 70. FIG. 4 is a flowchart showing a control process executed by the control unit 70. FIG. 5 is a flowchart showing the first conversion process executed by the control unit 70. FIG. 6 is a graph showing changes in the cumulative number PN of FG signals and the rotation speed RN of the developing roller 55 in the first conversion process.

  A configuration of the printer 1 according to an embodiment will be described with reference to FIGS. 1 to 6. In the following description, the right side of FIG. 1 is the front side F of the printer 1, the far side of the paper is the right side R of the printer 1, and the upper side of the paper is the upper side U of the printer 1. The printer 1 according to the present embodiment is a laser printer that forms an image on a sheet W using an electrophotographic method, and is an example of an image forming apparatus.

  FIG. 1 is a schematic diagram illustrating the overall configuration of the printer 1. As shown in FIG. 1, the printer 1 includes a supply unit 10, an image forming unit 42, a fixing unit 43, a housing 20, a motor M, and a transmission unit 45. The housing | casing 20 is an example of an apparatus main body.

  The supply unit 10 is provided at the bottom of the printer 1 and includes a tray 11, a pickup roller 12, a transport roller 13, and a registration roller 14. The pickup roller 12 takes out the sheets W stored in the tray 11 one by one, and the conveyance roller 13 and the registration roller 14 convey the sheet W taken out by the pickup roller 12 to the image forming unit 42.

  The image forming unit 42 includes a photosensitive drum 51, a charging unit 52, an exposure unit 41, a developing unit 53, and a transfer roller 54. The charging unit 52 uniformly charges the surface of the photosensitive drum 51. The exposure unit 41 irradiates the charged photosensitive drum 51 with the light beam L. As a result, an electrostatic latent image is formed on the surface of the photosensitive drum 51. The developing unit 53 is detachably attached to the housing 20. The developing unit 53 includes a developing roller 55 and a toner box 56. The developing roller 55 supplies the toner in the toner box 56 onto the photosensitive drum 51 by applying a developing bias, develops the electrostatic latent image formed on the photosensitive drum 51, and develops the photosensitive drum 51. A toner image is formed thereon. The transfer roller 54 is disposed so as to face the photosensitive drum 51, and transfers the toner image formed on the photosensitive drum 51 onto the sheet W. The photosensitive drum 51 is an example of a photoreceptor.

  The sheet W having the toner image transferred thereon is conveyed to the fixing unit 43, where the toner image is thermally fixed by the fixing unit 43 and discharged onto the upper surface of the housing 20. The housing 20 covers the supply unit 10, the image forming unit 42, the fixing unit 43, the motor M, and the transmission unit 45, and includes a front cover 22. The front cover 22 rotates around the shaft 21 and covers the opening 23 formed in the housing 20 so as to be opened and closed. The user can take out the developing unit 53 through the opening 23 and replace it with the outside of the housing 20.

  The transport roller 13, the registration roller 14, the photosensitive drum 51, the developing roller 55, and the fixing unit 43 are connected to a common motor M by a gear (not shown), and are driven by a driving force output from the motor M. Rotate. The conveyance roller 13, the registration roller 14, the photosensitive drum 51, and the fixing unit 43 are rotated at a constant speed by a constant driving force output from the motor M. On the other hand, the developing roller 55 is connected to the motor M via a transmission unit 45 that is a gear mechanism that transmits the driving force output from the motor M to the developing roller 55. Therefore, the rotation speed of the developing roller 55 is switched between two different speeds depending on the transmission unit 45 with respect to a constant driving force output from the motor M. The configuration of the motor M will be described later in detail.

  Specifically, the transmission unit 45 can switch a reduction ratio obtained by dividing the rotational speed of the motor M by the rotational speed RN of the developing roller between the Lo gear LG and the Hi gear HG smaller than the Lo gear LG. 34. Here, “Lo gear LG” means a reduction ratio during a period in which the developing roller 55 does not develop the electrostatic latent image formed on the photosensitive drum 51. The non-development period means a period during which no development bias is applied to the development roller 55. For example, a period before the sheet W comes to the image forming unit 42, a period after the sheet W leaves the image forming unit 42, and This means a period between the sheets W when the plurality of sheets W pass through the image forming unit 42 in succession. The Lo gear LG is an example of a first reduction ratio, and the Hi gear HG is an example of a second reduction ratio.

  The “Hi gear HG” means a reduction ratio during a period in which the electrostatic latent image formed on the photosensitive drum 51 is developed by the developing roller 55. When the transmission unit 45 is switched to the Lo gear LG, the moving speed of the surface of the photosensitive drum 51 becomes higher than the movement speed of the surface of the developing roller 55, and when the transmission unit 45 is switched to the Hi gear HG, The moving speed of the surface is smaller than the moving speed of the surface of the developing roller 55.

  FIG. 2 is a schematic diagram of the transmission unit 45. As shown in FIG. 2, the transmission unit 45 includes a transmission gear 30, a distribution gear 31, a first input gear 32, a second input gear 33, a switching mechanism 34, and an output gear 35.

  The transmission gear 30 receives the driving force from the motor M and transmits the driving force to the distribution gear 31. The distribution gear 31 distributes the driving force transmitted from the transmission gear 30 to the driving force transmission path for the Lo gear LG and the driving force transmission path for the Hi gear HG.

  Specifically, the distribution gear 31 is formed by integrating three types of gears 31A to 31C arranged coaxially, and the gear 31B, the gear 31A, and the gear 31C of the distribution gear 31 are arranged in this order. The outer diameter is reduced. The gear 31 </ b> A of the distribution gear 31 meshes with the transmission gear 30. The gear 31C of the distribution gear 31 meshes with the first input gear 32 and transmits the driving force to the driving force transmission path for the Lo gear LG. The gear 31B of the distribution gear 31 meshes with the second input gear 33 and transmits the driving force to the driving force transmission path for the Hi gear HG.

  The switching mechanism 34 selects either the driving force transmission path for the Lo gear LG or the driving force transmission path for the Hi gear HG, and outputs the driving force received from the selected driving force transmission path to the output gear. 35.

  Specifically, the switching mechanism 34 is formed with three types of gears 34A to 34C arranged coaxially, and the gear 34B, the gear 34A, and the gear 34C of the switching mechanism 34 have an outer diameter in this order. Is formed to be small. The gear 34B of the switching mechanism 34 meshes with the first input gear 32 and receives a driving force from the driving force transmission path for the Lo gear LG. The gear 34B of the switching mechanism 34 meshes with the second input gear 33 and receives a driving force from the driving force transmission path for the Hi gear HG.

  The gear 34C of the switching mechanism 34 meshes with the output gear 35. The gear 34C of the switching mechanism 34 is configured to rotate integrally with one of the gear 34A and the gear 34B selected by the control unit 70 which will be described later, and the gear selected by the CPU 71 which will be described later. The driving force received from the corresponding driving force transmission path is transmitted to the output gear 35. That is, in the switching mechanism 34, the control unit 70 selects whether the gear 34C of the switching mechanism 34 rotates integrally with the gear 34A or the gear 34B, so that the reduction ratio of the transmission unit 45 is set to the Lo gear. It is possible to switch between LG and Hi gear HG. The output gear 35 receives the driving force from the switching mechanism 34 and transmits the driving force to the developing roller 55. The switching mechanism 34 includes, for example, an electromagnetic clutch that connects the gear 34C so as to rotate integrally with one of the gear 34A and the gear 34B.

  FIG. 3 is a block diagram illustrating a circuit configuration of the control unit 70. As shown in FIG. 3, the printer 1 includes a central processing unit (hereinafter referred to as CPU) 71, ROM 72, RAM 73, nonvolatile memory 74, ASIC (in addition to the supply unit 10 and the image forming unit 42 described above. Application Specific Integrated Circuit) 75, operation unit 46, communication unit 47, drive unit 44, and new article detection unit 48.

  Various programs are stored in the ROM 72. The various programs include programs for controlling the operation of each unit of the printer 1, such as a program for executing control processing described later. The RAM 73 is used as a work area when the CPU 71 executes various programs and as a temporary storage area for data. The non-volatile memory 74 may be any rewritable memory such as NVRAM, flash memory, HDD, or EEPROM. The nonvolatile memory 74 is an example of a storage unit.

  The CPU 71 controls each unit of the printer 1 according to a program read from the ROM 72. The ASIC 75 is a hardware circuit dedicated to image processing, for example. The operation unit 46 includes various buttons and a touch panel that accept operations by the user. The touch panel also functions as a display unit that displays various types of information. The communication unit 47 communicates with an external device such as a personal computer by a wireless communication method or a wired communication method. The operation unit 46 is an example of a notification unit.

  The drive unit 44 drives the motor M. As shown in FIG. 3, the motor M includes a motor main body 61, Hall elements 64 to 66, and an FG (Frequency Generator) output unit 67. The motor main body 61 is a three-phase brushless DC motor, and includes a rotor 62 having magnetic poles and a stator 63 having a plurality of exciting coils. The stator 63 includes coils corresponding to, for example, the U phase, the V phase, and the W phase.

  The Hall elements 64 to 66 are provided corresponding to each phase (U phase, V phase, W phase) of the motor M. The hall elements 64 to 66 generate a hall signal HS corresponding to the change in the magnetic field and output the hall signal HS to the drive unit 44. The FG output unit 67 generates an FG signal. The FG signal is a pulse signal that becomes H level at a timing when the rotational position of the rotor 62 becomes a specific position and becomes L level at other timings. Therefore, the FG signal is an example of a control signal corresponding to the rotational speed of the rotor 62, that is, the unit rotational speed of the motor M. For example, the FG output unit 67 generates an FG signal from the hall signal HS.

  The drive unit 44 drives the motor M by switching the excitation coils in order with respect to the plurality of excitation coils of the stator 63 based on the hall signals HS of the respective phases given from the motor M, and causing the drive current to flow. The drive unit 44 also controls the rotational speed of the motor M based on the FG signal to drive the motor M. Thus, the motor M is controlled to rotate at a predetermined speed during the image forming period of the sheet W. The drive unit 44 outputs the FG signal given from the FG output unit 67 to the control unit 70.

  As shown in FIG. 1, the new article detection unit 48 includes a detection sensor 81 provided in the housing 20, a first new article detection gear 82 provided in the developing unit 53 and rotated by a driving force from the motor M, 2 new article detection gear 83. The second new article detection gear 83 has a protrusion 83A and a chipped gear 83B.

  In the new article detection unit 48, when the developing unit 53 is in a new state, as shown by a solid line in FIG. 1, the first new article detection gear 82 and the chipped gear 83B are engaged with each other. In this case, when a driving force is input from the motor M to the first new article detection gear 82, the detection sensor 81 comes into contact with the protrusion 83A and detects the protrusion 83A. On the other hand, when the developing unit 53 is not in a new state, as shown by a broken line in FIG. 1, the first new product detection gear 82 and the chipped gear 83B are not engaged with each other. In this case, even if a driving force is input from the motor M, the detection sensor 81 does not come into contact with the protrusion 83A and does not detect the protrusion 83A. The control unit 70 determines whether or not the developing unit 53 is new based on whether or not the detection sensor 81 has detected.

  The control unit 70 counts the number of rotations of the motor M and the number of rotations RN of the developing roller 55 based on the FG signal input from the driving unit 44. FIG. 4 is a flowchart showing a control process executed by the control unit 70. When the power of the printer 1 is turned on, the control unit 70 executes control processing every predetermined time. The control process includes counting the number of rotations RN of the developing roller 55 based on the FG signal.

  In the control process, the control unit 70 determines whether the developing unit 53 is new using the new product detection unit 48 (S100). When the control unit 70 detects that the developing unit 53 is new (S100: YES), the control unit 70 initializes a cumulative number ZN that is a cumulative value of the rotational speed RN of the developing roller 55 stored in the nonvolatile memory 74. (S110). On the other hand, when the control unit 70 does not detect that the developing unit 53 is new (S100: NO), the control unit 70 proceeds to the next process without initializing the cumulative number ZN.

  The control unit 70 counts the cumulative number PN of FG signals from the pulses of the FG signal input from the drive unit 44 (S120), and temporarily stores it in the RAM 73. The cumulative number PN of FG signals is an example of a cumulative value of control signals.

  The control unit 70 determines whether or not the reduction ratio of the transmission unit 45 is switched to the Lo gear LG (S130). When the control unit 70 determines that the reduction ratio of the transmission unit 45 is switched to the Lo gear LG (S130: YES), the accumulated number PN of the counted FG signals is used to rotate the developing roller 55 in the first conversion process. Converted into a number RN, the number of rotations RN of the developing roller 55 is counted (S140).

  FIG. 5 is a flowchart showing the first conversion process executed by the CPU 71 of the control unit 70. FIG. 6 is a graph showing changes in the cumulative number PN of FG signals and the rotation speed RN of the developing roller 55 in the first conversion process. In the first conversion process, the CPU 71 compares the accumulated number PN of the FG signal with the reference number KN for each reference time ΔT, and determines whether or not the accumulated number PN of the FG signal is equal to or greater than the reference number KN ( S300). Here, the “reference number KN” is a value corresponding to one rotation of the developing roller 55 in the Lo gear LG, and is stored in the ROM 72. When the cumulative number PN of FG signals is less than the reference number KN (S300: NO), the CPU 71 ends the first conversion process.

  On the other hand, when the cumulative number FG of the FG signals becomes equal to or greater than the reference number KN (S300: YES), the CPU 71 converts the FG signal of the reference number KN into one rotation of the developing roller 55, and the rotation number of the developing roller 55 “1” is added to RN (S320), and the reference number KN is subtracted from the cumulative number PN of FG signals (S330). The CPU 71 temporarily stores the cumulative number PN of the FG signal after subtraction in the RAM 73, and adds the cumulative number PN of the FG signal input from the drive unit 44 after the subtraction to the cumulative number PN of the FG signal after the subtraction. Then, the counting of the cumulative number PN of the subtracted FG signals is restarted (S340), and the first conversion process is ended. The reference number KN is an example of a predetermined unit rotational speed.

  In addition, when the CPU 71 determines that the reduction ratio of the transmission unit 45 is switched to the Hi gear HG (S130: NO), the accumulated number PN of the counted FG signals is used to rotate the developing roller 55 in the second conversion process. Converted into a number RN, the number of rotations RN of the developing roller 55 is counted (S150).

  The second conversion process is different from the first conversion process only in the process of converting the FG signal of the reference number KN with the rotation of the developing roller 55, and the description of the flowchart showing the second conversion process is omitted. In the second conversion process, the CPU 71 converts the FG signal of the reference number KN into one rotation when the cumulative number PN of FG signals becomes equal to or greater than the reference number KN. Further, the CPU 71 multiplies the one rotation speed by the speed change coefficient HK to convert the FG signal of the reference number KN into the speed of the speed change coefficient HK of the developing roller 55 and sets the speed RN of the developing roller 55 to "Transmission coefficient HK" is added.

Here, the “transmission coefficient HK” is a value obtained by dividing the Lo gear LG by the Hi gear HG, and is stored in the ROM 72. Specifically, since the Lo gear LG is larger than the Hi gear HG, the transmission coefficient HK is larger than 1. For this reason, in the second conversion process, the FG signal of the reference number KN is converted into a shift count HK times one rotation number of the developing roller 55, and the rotation number RN of the developing roller 55 is counted. That is, when the CPU 71 determines that the reduction ratio of the transmission unit 45 is switched to the Hi gear HG, the CPU 71 determines that the reduction ratio of the transmission unit 45 is switched to the Lo gear LG. The rotation number RN of the developing roller 55 is counted.
Lo Gear LG> Hi Gear HG
Speed change coefficient HK = Lo gear LG / Hi gear HG

  The controller 70 adds the counted number of rotations RN of the developing roller 55 to the cumulative number ZN (S160), and stores the cumulative number ZN after the addition in the nonvolatile memory 74 (S170).

  The control unit 70 determines whether or not the cumulative number ZN after the addition is equal to or greater than the notification rotational speed HN (S180). When the cumulative number ZN becomes equal to or greater than the notification rotational speed HN (S180: YES), the control unit 70 displays a message prompting replacement of the developing unit 53 on the touch panel of the operation unit 46 and notifies the control (S190). The image forming operation for the sheet W is not executed until the processing is completed and the developing unit 53 is replaced. On the other hand, when the accumulated number ZN after addition is less than the notification rotation number HN (S180: NO), the control unit 70 ends the control process without displaying a message.

  In the printer 1, the drive unit 44 drives the motor M based on the hall signal HS given from the motor M, and an FG signal is generated from the hall signal HS. For this reason, it is possible to indirectly count the rotation speed RN of the developing roller 55 rotated by the driving force output from the motor M from the FG signal. Therefore, in the printer 1 of the present embodiment, the control unit 70 counts the rotation speed RN of the developing roller 55 based on the FG signal used for driving the motor M. Therefore, the control unit 70 can count the rotation speed RN of the developing roller 55 without requiring a dedicated device such as a number counter for counting the rotation speed RN of the developing roller 55.

  In the printer 1, the control unit 70 compares the reduction ratio of the transmission unit 45 with the Hi gear HG (S130: NO) as compared to the case with the reduction ratio of the transmission unit 45 of the Lo gear LG (S130: YES). The accumulated number PN of the FG signals is converted to a large value, and the rotation number RN of the developing roller 55 is counted. Therefore, the control unit 70 can reduce an error in counting the number of rotations RN of the developing roller 55 even when the reduction ratio of the transmission unit 45 is switched.

  In the printer 1, when the speed reduction ratio of the transmission unit 45 is Hi gear HG, the control unit 70 converts the FG signal of the reference number KN into one rotation in the second conversion process, and then the speed change coefficient HK of the developing roller 55. Convert to the number of revolutions. The transmission coefficient HK is greater than 1. Therefore, the control unit 70 can reduce an error in counting the rotation speed RN of the developing roller 55 compared to the case of converting to the rotation speed of the transmission coefficient HK of 1 or less, and the rotation speed of the developing roller 55. RN can be accurately counted.

  Specifically, during the period in which the electrostatic latent image formed on the photosensitive drum 51 is developed by the developing roller 55, the reduction ratio of the transmission unit 45 is set to Hi gear HG, and the moving speed of the surface of the developing roller is set to the surface of the photosensitive member. Make it larger than the moving speed. On the other hand, when the photosensitive drum 51 is not developed by the developing roller 55, the speed reduction ratio of the transmission unit 45 is Lo gear LG, and the moving speed of the surface of the developing roller is smaller than the moving speed of the surface of the photosensitive member. The rotational speed RN of 55 is suppressed. Therefore, the control unit 70 can reduce an error in counting the rotation number RN of the developing roller 55 while suppressing the rotation number RN of the developing roller 55.

  In the printer 1, the control unit 70 compares the cumulative number PN of the FG signal with the reference number KN, and when the cumulative number PN of the FG signal is equal to or greater than the reference number KN (S300: YES), A predetermined number of revolutions RN are added. Therefore, the control unit 70 can count the rotation speed RN of the developing roller 55 based on the FG signal.

  In the printer 1, the control unit 70 adds a predetermined number of the rotation speed RN of the developing roller 55, and then subtracts the reference number KN from the cumulative number PN of the FG signal (S330). Therefore, the control unit 70 can continuously count the rotation speed RN of the developing roller 55 by comparing the accumulated number PN of the FG signal with the reference number KN.

  In the printer 1, the control unit 70 adds the cumulative number PN of the FG signal to the cumulative number PN of the FG signal after subtracting the reference number KN, and restarts counting the cumulative number PN of the FG signal (S340). In the first conversion process and the second conversion process, since the control unit 70 compares the cumulative number PN of the FG signal with the reference number KN for each reference time ΔT, the cumulative number PN of the FG signal and the reference number When comparing KN, the cumulative number PN of FG signals may be equal to the reference number KN (see timing TB in FIG. 6), or the cumulative number PN of FG signals may exceed the reference number KN (see FIG. 6). (See FIG. 6 Timing TA). Therefore, it is possible that the cumulative number PN of the FG signal after subtracting the reference number KN is not zero.

  In the printer 1 of this embodiment, the control unit 70 adds the cumulative number PN of the FG signal to the cumulative number PN of the FG signal after subtraction of the reference number KN, and counts the cumulative number PN of the FG signal after subtraction. Therefore, an error that occurs when counting the number of rotations of the developing roller can be suppressed. Further, since the error is suppressed, the control unit 70 can freely set the reference time ΔT in a range shorter than the cumulative number FG of the FG signal is counted as the reference number KN.

  In the printer 1, when the cumulative number ZN becomes equal to or greater than the notification rotation number HN (S180: YES), the control unit 70 displays a message prompting replacement of the developing unit 53 on the touch panel of the operation unit 46 to notify the user. (S190). Therefore, the control unit 70 can notify a message prompting replacement of the developing unit 53 based on the FG signal used for driving the motor M, and the user can know the replacement time of the developing unit 53. it can.

  In the printer 1, when the control unit 70 detects that the developing unit 53 is new (S100: YES), the control unit 70 initializes the cumulative number ZN (S110). Therefore, the control unit 70 can count the cumulative number ZN of new development units 53 from the initial value.

  The technology disclosed in the present specification is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit of the technology.

  The image forming apparatus is not limited to a single printer, and may be a multifunction machine having a scanning function and a facsimile function. The present invention can also be applied to a copying machine.

  The image forming apparatus may be a direct transfer tandem type color laser printer or an intermediate transfer type color laser printer.

  The motor body 61 provided in the motor M is not limited to a three-phase brushless DC motor, and may be a DC motor having a brush or a pulse motor. When the motor main body 61 is a DC motor having a brush, the drive unit 44 drives the motor M based on the pulse signal from the encoder attached to the motor main body 61 and sends the pulse signal from the encoder to the control unit 70. Output. When the motor body 61 is a pulse motor, the drive unit 44 gives a pulse signal to the pulse motor to drive the motor M, and outputs the pulse signal to the control unit 70. The control unit 70 counts the number of rotations of the motor M and the number of rotations RN of the developing roller 55 based on the pulse signal given from the driving unit 44 to the pulse motor. In this case, the Hall elements 64 to 66 and the FG output unit 67 are not necessary for the motor M.

  The structure of the transmission part 45 is not restricted to the structure of the said embodiment. Further, the reduction ratio that can be switched by the transmission unit 45 is not limited to two types of Lo gear LG and Hi gear HG, and may be switchable to three or more reduction ratios.

  In the above embodiment, in the control process, the control unit 70 displays the message for prompting the replacement of the developing unit 53 on the touch panel of the operation unit 46 and the process of storing the cumulative number ZN in the nonvolatile memory 74 (S170). The example which performs both processes with the process (S190) to alert | report is shown. However, the process of storing the cumulative number ZN in the nonvolatile memory 74 (S170) is not necessarily executed. That is, in the control process, without executing the process of storing the cumulative number ZN in the nonvolatile memory 74 (S170), a process of displaying and informing the touch panel of the operation unit 46 that prompts for replacement of the developing unit 53 ( S190) may be executed.

  In the above embodiment, in the control process, the control unit 70 displays an example in which a predetermined message is displayed on the touch panel of the operation unit 46 when the cumulative number ZN is equal to or greater than the notification rotation number HN (S180: YES). . However, the condition for displaying a predetermined message on the touch panel of the operation unit 46 is not limited to this. For example, the replacement rotation speed is set as an initial value for the developing roller 55, and the control unit 70 subtracts the converted rotation speed RN of the developing roller 55 from the replacement rotation speed in the first conversion process and the second conversion process. In the case where the process is performed, a predetermined message may be displayed on the touch panel of the operation unit 46 when the cumulative number ZN becomes equal to or less than the notification rotation number HN.

  In the embodiment described above, in the control process, an example in which a message prompting replacement of the developing unit 53 is displayed and notified on the touch panel of the operation unit 46 (S190) has been described. However, the content displayed on the touch panel of the operation unit 46 is not limited to this. For example, the life of the developing roller 55 may be notified.

  In the above-described embodiment, in the control process, it is detected that the developing unit 53 is new using the protrusion provided on the developing unit 53 and the detection sensor provided on the housing 20 (S100). Indicated. However, the detection method for detecting that the developing unit 53 is new is not limited to this. For example, the developing unit 53 is equipped with a storage unit, and the developing unit 53 is new based on the data stored in the storage unit. For example, a method for detecting the fact may be used.

20: Housing 22: Front cover 23: Opening 34: Switching mechanism 44: Driving unit 45: Transmission unit 51: Photosensitive drum 53: Developing unit 55: Developing roller 61: Motor main body 62: Rotor 63: Stator 64- 66: Hall element 67: FG output section PN: Cumulative number of FG signals RN: Number of rotations of developing roller ZN: Cumulative number

Claims (13)

A photoreceptor,
A motor,
A drive unit for driving the motor;
A developing unit having a developing roller that is rotated by a driving force output from the motor and that develops an electrostatic latent image formed on the photosensitive member;
A storage unit;
A control unit,
The controller is
Counting the number of rotations of the developing roller based on a control signal corresponding to a unit number of rotations of the motor, which is given from the motor to the drive unit or from the drive unit to the motor,
An image forming apparatus that stores a cumulative value of the counted number of rotations of the developing roller in the storage unit. The image forming apparatus according to claim 1,
A transmission unit that transmits the driving force output from the motor to the developing roller;
The transmission unit can switch a reduction ratio obtained by dividing the rotation speed of the motor by the rotation speed of the developing roller between a first reduction ratio and a second reduction ratio smaller than the first reduction ratio,
The controller is
When the reduction ratio of the transmission unit is the first reduction ratio, the cumulative value of the control signal is converted to a larger value compared to the case where the reduction ratio of the transmission unit is the second reduction ratio. An image forming apparatus that counts the number of rotations. The image forming apparatus according to claim 2,
When a value obtained by dividing the first reduction ratio by the second reduction ratio is a shift coefficient,
The controller is
When the reduction ratio of the transmission unit is the first reduction ratio, a predetermined unit number of rotations is added as the number of rotations of the developing roller on the condition that the cumulative value of the control signal becomes a reference value,
When the speed reduction ratio of the transmission unit is the second speed reduction ratio, a value obtained by multiplying the predetermined unit rotational speed by the speed change coefficient is provided on the condition that the cumulative value of the control signal becomes the reference value. An image forming apparatus that adds the number of rotations of the developing roller. The image forming apparatus according to claim 2, wherein:
The controller is
When the reduction ratio of the transmission unit is the first reduction ratio, the developing roller does not develop the electrostatic latent image formed on the photoconductor,
An image forming apparatus that develops an electrostatic latent image formed on the photoconductor with the developing roller when the speed reduction ratio of the transmission unit is the second speed reduction ratio. An image forming apparatus according to any one of claims 2 to 4, wherein
The photoconductor is rotated by a driving force output from the motor,
When the speed reduction ratio of the transmission unit is the first speed reduction ratio, the moving speed of the surface of the photoconductor is larger than the moving speed of the surface of the developing roller,
The image forming apparatus, wherein when the speed reduction ratio of the transmission unit is the second speed reduction ratio, the moving speed of the surface of the photosensitive member is smaller than the moving speed of the surface of the developing roller. An image forming apparatus according to any one of claims 1 to 5, wherein
The controller is
An image forming apparatus that adds the number of rotations of the developing roller and subtracts the reference value from the cumulative value of the control signal on condition that the cumulative value of the control signal is equal to or greater than a reference value. The image forming apparatus according to claim 6,
The controller is
An image forming apparatus that adds a cumulative value of the control signal that is given from the motor to the drive unit or that is given from the drive unit to the motor to the cumulative value of the control signal after subtraction. An image forming apparatus according to any one of claims 1 to 7,
With a notification unit,
The controller is
An image forming apparatus that causes the notification unit to notify the condition that the cumulative value of the rotation speed of the developing roller has reached a predetermined cumulative value. An image forming apparatus according to any one of claims 1 to 8,
It has a device body,
The developing unit is detachably attached to the apparatus main body,
The controller is
An image forming apparatus that initializes a cumulative value of the number of rotations of the developing roller stored in the storage unit on condition that the developing unit is new. An image forming apparatus according to any one of claims 1 to 9, wherein
The motor has a rotor having magnetic poles and a stator having a plurality of exciting coils,
The image forming apparatus, wherein the driving unit causes a current to flow through the plurality of exciting coils based on the control signal corresponding to the rotation of the rotor. A photoreceptor,
A motor,
A drive unit for driving the motor;
A developing unit having a developing roller that is rotated by a driving force output from the motor and that develops an electrostatic latent image formed on the photosensitive member;
A notification unit;
A control unit,
The controller is
Counting the number of rotations of the developing roller based on a control signal corresponding to a unit number of rotations of the motor, which is given from the motor to the drive unit or from the drive unit to the motor,
An image forming apparatus that causes the notifying unit to notify on condition that the accumulated value of the counted number of rotations of the developing roller has reached a predetermined accumulated value. A photoreceptor,
A motor,
A drive unit for driving the motor;
A developing unit having a developing roller that is rotated by a driving force output from the motor and that develops an electrostatic latent image formed on the photosensitive member;
A storage unit;
An image forming apparatus control method comprising:
A counting step of counting the number of rotations of the developing roller based on a control signal corresponding to a unit number of rotations of the motor, which is given from the motor to the driving unit or from the driving unit to the motor;
A storage step of storing a cumulative value of the number of rotations of the developing roller counted in the counting step in the storage unit;
A control method comprising: A photoreceptor,
A motor,
A drive unit for driving the motor;
A developing unit having a developing roller that is rotated by a driving force output from the motor and that develops an electrostatic latent image formed on the photosensitive member;
A storage unit;
A computer program for controlling an image forming apparatus comprising:
A counting process for counting the number of rotations of the developing roller based on a control signal corresponding to a unit number of rotations of the motor, which is given from the motor to the driving unit or from the driving unit to the motor;
A storage process for storing a cumulative value of the rotation speed of the developing roller counted in the counting process in the storage unit;
A computer program that executes

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