JP4646171B2 - Developing unit and image forming apparatus having the developing unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a developing unit that visualizes an electrostatic latent image formed on an image carrier as a toner image, and an image forming apparatus having the developing unit.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, an image forming apparatus in which a developing unit is detachably attached to an image forming apparatus main body and an electrostatic latent image formed on an image carrier by the developing unit is visualized has been known. Such an image forming apparatus is configured as an electronic copying machine, a printer, a facsimile, or a multifunction machine having at least two of these functions. At this time, it is also known to use a unit in which a toner cartridge is detachably attached to the unit main body as the developing unit. The unit main body carries a toner storage portion and toner contained therein, and develops the unit. And a toner carrier for transporting the toner to the developing area. When the amount of toner in the toner reservoir decreases due to toner consumption, toner is replenished to the toner reservoir from a toner cartridge that is detachably assembled to the unit body.
[0003]
When the toner in the toner cartridge is replenished as described above and the toner in the toner cartridge runs out, the empty toner cartridge is replaced with a new toner cartridge containing toner. When a new toner cartridge is installed in the unit main body, the amount of toner in the toner storage unit is small, so it is necessary to replenish toner from the installed new toner cartridge to the toner storage unit. If this toner replenishing operation is referred to as an initial replenishing operation, a small amount of toner corresponding to the amount of toner consumed is replenished to the toner reservoir after the initial replenishing operation. A normal toner replenishment operation from the toner cartridge to the toner storage unit is performed.
[0004]
In order to perform the initial replenishment operation described above, conventionally, a detection piece is provided on a new toner cartridge, and when the new toner cartridge is mounted on the unit main body, the detection piece is attached by a sensor on the image forming apparatus main body side. It is configured to detect and perform an initial replenishment operation based on the detection signal. On the other hand, when a new toner cartridge is mounted on the unit main body, the detection piece is damaged, and thereafter, the detection piece is not detected and only the normal toner replenishment operation is performed.
[0005]
As described above, even in the conventional developing unit, when a new toner cartridge is mounted on the unit body, the initial replenishment operation for replenishing the toner reservoir with a larger amount of toner than the normal toner replenishment amount is performed. Conventionally, when a new toner cartridge is mounted on the unit body, the detection piece is broken and the broken detection piece becomes waste, so that the material is wasted. I could not escape the shortcomings.
[0006]
[Problems to be solved by the invention]
The first object of the present invention is to provide a developing unit capable of eliminating the above-mentioned conventional defects, and a second object of the present invention is to provide an image forming apparatus having the developing unit.
[0007]
[Means for Solving the Problems]
In order to achieve the first object, the present invention includes a unit case having a toner reservoir therein, and a toner carrier that carries the toner contained in the toner reservoir and transports the toner to the development region. And a unit main body detachably attached to the image forming apparatus main body, and a toner cartridge containing toner to be replenished to a toner storage portion of the unit main body, the toner cartridge being detachably attached to the unit main body In the developing unit, the toner cartridge is provided with a non-volatile memory in which new data indicating that the toner cartridge is new is written in advance, and is new to the unit main body mounted on the image forming apparatus main body. The non-volatile memory is mounted by the reading means on the image forming apparatus main body side. When reading the stored contents, the new data is erased, and the new data is read to replenish the toner from the toner cartridge to the toner storage portion storing a smaller amount of toner than the predetermined amount. The shipping status data indicating that the toner cartridge is shipped in a state of being mounted in the unit main body is controlled so that an initial replenishment operation for storing a predetermined amount of toner in the toner storage unit is executed. A developing unit that is written in advance in the volatile memory, has a toner cartridge mounted in the unit main body at the time of shipment, and has no toner in the toner storage portion is mounted in the main body of the image forming apparatus. When reading the stored contents, the shipping status data is erased and the shipping status data is As a result, an initial mass supply operation is performed in which a larger amount of toner than the initial supply operation is supplied from the toner cartridge to the toner storage unit, and the predetermined amount of toner is stored in the toner storage unit. The developing unit is characterized in that it is controlled as described above (claim 1).
[0009]
In order to achieve the second object of the present invention, the developing unit according to claim 1 and an image carrier on which an electrostatic latent image visualized as a toner image is formed by the developing unit. An image forming apparatus is provided (claim 2).
[0010]
At that time, when a new developing unit having a toner cartridge mounted on the unit main body is mounted on the image forming apparatus main body, the reading of the shipment status data by the reading means on the image forming apparatus main body side causes the previous developing unit to It is advantageous that the image forming frequency data is configured to be initialized.
[0011]
The image forming apparatus according to claim 2 or 3, wherein at least one of the initial replenishment operation, the initial mass replenishment operation, and the initialization of the image forming frequency data can be executed by a manual operation. It is advantageous (claim 4).
[0012]
Further, in the image forming apparatus according to any one of claims 2 to 4, the developing unit has a developing position when a toner image is formed on the image carrier, and is separated from the image carrier more than the developing position. It is advantageous that the nonvolatile memory is configured to perform data access at a time other than when the developing unit is moving, and is supported so as to be movable between the retracted positions. .
[0013]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the drawings.
[0014]
FIG. 1 is a schematic partial cross-sectional view showing an example of an image forming apparatus having a developing unit. The image forming apparatus shown here has a drum-shaped photoconductor 1 which is an example of an image carrier, and the photoconductor 1 is driven to rotate clockwise during the image forming operation. Is applied to initialize the surface potential of the photoreceptor. Next, the surface of the photoreceptor is uniformly charged to a predetermined polarity by the charging device 3.
[0015]
On the other hand, a laser beam L that is optically modulated in accordance with document image information read by a scanner not shown in FIG. 1 is emitted from the laser writing unit 4, and the laser beam L is applied to the charging surface of the photoreceptor 1. Irradiation causes an electrostatic latent image to be formed on the photoreceptor. The electrostatic latent image is visualized as a toner image when passing through the developing unit 5. Details of the configuration and operation of the developing unit 5 will be described later.
[0016]
The toner image formed on the photoconductor is transferred to the transfer paper P fed between the photoconductor 1 and the transfer device 6 by the action of the transfer device 6, and the transferred toner image is not shown. The image is fixed on the transfer paper P by the apparatus. On the other hand, toner remaining on the photoreceptor without being transferred to the transfer paper P is removed by the cleaning device 7. The image forming apparatus shown in FIG. 1 has a facsimile function in addition to a copying function.
[0017]
As described above, the image forming apparatus of the present example has an image carrier including the developing unit 5 and the photosensitive member 1 on which an electrostatic latent image visualized as a toner image by the developing unit 5 is formed. is doing.
[0018]
As shown in an enlarged view in FIG. 2, the developing unit 5 includes a unit main body 8 and a toner cartridge 9 detachably attached to the unit main body 8. The unit main body 8 includes a unit case 11 having a toner reservoir 10 therein, and a developing roller 12 that is an example of a toner carrier that carries and transports the powdery toner T accommodated in the toner reservoir 10. have. The developing roller 12 is rotatably supported by the unit case 11 and is in contact with or close to the surface of the photoreceptor 1.
[0019]
During the developing operation, the developing roller 12 is driven to rotate counterclockwise in FIGS. 1 and 2, and at this time, the toner T in the toner storage unit 10 is supplied to the peripheral surface of the developing roller 12 by the supply roller 13 supported by the unit case 11. The supplied toner is carried on the developing roller 12 and conveyed, the layer thickness is regulated by the layer thickness regulating blade 14, and conveyed to the developing area where the photoreceptor 1 and the developing roller 12 are opposed to each other. While the toner is transported in this manner, the toner is triboelectrically charged to a predetermined polarity, and the toner reaching the development area is electrostatically transferred to the electrostatic latent image formed on the photosensitive member 1 and the latent image is transferred to the latent image. The image is visualized as a toner image. The unit main body 8 configured as described above is detachably mounted on the image forming apparatus main body.
[0020]
When the developing operation as described above is performed, the toner T in the toner storage unit 10 is consumed, and when it is detected by a sensor (not shown) that the toner amount in the toner storage unit 10 is equal to or less than a predetermined amount, the unit Toner is supplied to the toner storage unit 10 from the toner cartridge 9 containing the toner T1 supplied to the toner storage unit 10 of the main body 8.
[0021]
As the toner replenishing means for sending the toner T1 in the toner cartridge to the toner reservoir 10, an appropriate configuration known in the art can be adopted. However, in the illustrated example, the toner replenishing roller 15 disposed at the opening of the toner cartridge 9 is used. Is employed, and when it is detected that the amount of toner in the toner storage unit 10 has become a predetermined amount or less, the toner supply roller 15 is driven to rotate, whereby the toner T1 in the toner cartridge is supplied to the toner storage unit 10. The This is a normal toner supply operation.
[0022]
When the above-described toner replenishing operation is repeatedly performed, as shown in FIG. 3, the remaining amount of toner in the toner cartridge 9 becomes very small, or the toner T1 substantially disappears. If this state is called that the toner cartridge 9 has run out of toner and has become empty, when the toner cartridge 9 becomes empty in this way, even if a decrease in the toner amount in the toner reservoir 10 is detected, The toner is not replenished. Even when the toner replenishing operation is performed in this way, as shown in FIG. 3, when the toner amount in the toner storage unit 10 does not return to the predetermined amount shown in FIG. A display for replacing the toner cartridge 9 with a new toner cartridge containing the toner T1 is displayed.
[0023]
According to the display, the user opens the front door (not shown) of the main body of the image forming apparatus, pulls out the toner cartridge 9 toward the front side in the direction perpendicular to the paper surface of FIG. A new toner cartridge containing toner is attached to the unit main body 8. FIG. 4 shows a state when the new toner cartridge 9 is set in the unit main body 8 in this way. In this state, the amount of the toner T in the toner storage unit 10 is smaller than the predetermined amount shown in FIG. 2, so that if the image forming operation is resumed as it is, the toner image formed on the photosensitive member 1 Concentration is abnormally low. Therefore, before resuming the image forming operation, it is necessary to replenish the toner reservoir 10 with the toner T1 in the toner cartridge 9 and return the amount of toner T in the toner reservoir 10 to the predetermined amount shown in FIG.
[0024]
Therefore, the toner cartridge 9 is provided with a non-volatile memory 17 in which new data indicating that the toner cartridge 9 is new is written in advance. The image forming apparatus main body side is provided with reading means (not shown) for reading the stored contents of the nonvolatile memory 17, and the unit main body 8 mounted on the image forming apparatus main body side is shown in FIG. Thus, when the new toner cartridge 9 is mounted, the connector 18 of the nonvolatile memory 17 and the connector 19 of the reading means provided in the image forming apparatus main body are in surface contact, and the nonvolatile memory 17 and the reading means are connected. . When the front door is closed in this state, the storage content of the nonvolatile memory 17 is read by the reading means. At this time, new data in the nonvolatile memory 17 is erased, and new data is read by the reading unit, so that a smaller amount of toner T than the predetermined amount shown in FIG. The operation of replenishing toner to the toner reservoir 10 and storing the predetermined amount of toner T shown in FIG. That is, the toner supply roller 15 is driven to rotate, the toner T1 in the toner cartridge 9 is discharged to the toner storage unit 10, and the amount of toner T in the toner storage unit 10 reaches the predetermined amount shown in FIG. The rotation of the toner supply roller 15 is stopped, and the toner supply operation is terminated. This is an initial supply operation, and the developing unit 5 is controlled so that the initial supply operation is executed. In this way, a predetermined amount of toner T is stored in the toner storage section 10 as shown in FIG. 2, and the image forming operation is resumed in this state, so that a problem that the image density of the toner image is abnormally lowered can be prevented.
[0025]
After the initial replenishment operation is performed, new data in the nonvolatile memory 17 has been erased, so that the initial replenishment operation is not performed again, and only the normal toner replenishment operation described above is performed.
[0026]
As described above, the initial replenishment operation can be performed by detecting that the toner cartridge 9 is new only by exchanging data without damaging the detection piece of the toner cartridge. Can prevent unnecessary consumption.
[0027]
When the empty toner cartridge 9 removed from the unit main body 8 still withstands use, the toner cartridge 9 can be refilled with toner and used as a new toner cartridge. In this case, new data is written again in the non-volatile memory 17 provided in the toner cartridge, and the toner cartridge is used as a new toner cartridge mounted on the unit main body 8 as described above. In this way, the toner cartridge can be used many times until it deteriorates and can no longer be used. As can be seen from the above, new toner cartridges include toner cartridges that have been mounted on the image forming apparatus main body and have not been used, and toner cartridges that have been refilled and regenerated. .
[0028]
By the way, since the elements of the developing unit 5, for example, the developing roller 12 deteriorate with time, when the image forming operation is performed a predetermined number of times by the developing unit 5, the entire developing unit 5 is replaced with a new unit. . That is, the number of image formation performed by the developing unit 5 is counted by a counter (not shown) provided in the main body of the image forming apparatus, and when this reaches a predetermined number (for example, 100,000 times), the display unit In addition, an indication that the developing unit 5 should be replaced with a new unit is displayed.
[0029]
In accordance with this display, the user opens the front door, pulls out the entire developing unit 5 in the front direction perpendicular to the paper surface in FIG. 2, and then forms a new developing unit 5 having a toner cartridge containing toner. Attach to the main unit. The state at this time is shown in FIG. As can be seen from this drawing, when a new developing unit 5 is mounted on the image forming apparatus main body, no toner is present in the toner storage unit 10. Therefore, prior to resuming the image forming operation, the toner storage unit 10 is supplied with a larger amount of toner than in the initial supply operation, and the toner storage unit 10 stores the predetermined amount of toner shown in FIG. Then, it is necessary to restart the image forming operation. In order to meet this requirement, the developing unit 5 of this example employs the following configuration in addition to the configuration described above.
[0030]
As shown in FIG. 5, when the developing unit 5 is attached to the image forming apparatus main body, the toner cartridge 9 is assembled to the unit main body 8. In a state where both are assembled in this way, the developing unit is shipped from a factory or the like, and this is directly attached to the image forming apparatus main body. Paying attention to this point, shipping status data indicating that the toner cartridge 9 has been shipped in the state of being mounted on the unit main body 8 is written in the nonvolatile memory 17 in advance.
[0031]
When the developing unit 5 in which the toner cartridge 9 is mounted on the unit main body 8 at the time of shipment and no toner is present in the toner storage portion 10 is mounted on the main body of the image forming apparatus as shown in FIG. 5 and the front door is closed. The contents stored in the non-volatile memory 17 are read by the above-mentioned reading means. At this time, in addition to the new data, the above-mentioned shipping status data is also erased, and the shipping status data is read by the reading means, thereby A larger amount of toner than the initial replenishment operation is replenished from the toner cartridge 9 to the toner storage unit 10, and a predetermined amount of toner T shown in FIG. 2 is stored in the toner storage unit 10. The toner supply roller 15 is rotationally driven for a longer period of time than during the initial supply operation, and the predetermined amount of toner T shown in FIG. This is the initial mass supply operation, and the developing unit 5 is controlled so that the initial mass supply operation is executed. Since the image forming operation is resumed in this state, it is possible to prevent a problem that the image density of the toner image is abnormally lowered.
[0032]
Also in this case, after the initial mass supply operation is performed, the new product data and the shipping status data in the nonvolatile memory 17 are erased, so that the initial supply operation and the initial mass supply operation are not performed again. Only the normal toner supply operation is performed.
[0033]
Here, as shown in FIG. 5, when a new developing unit 5 is mounted on the image forming apparatus main body and the use of the developing unit 5 is started after the initial mass replenishment operation is executed, the life of the developing unit 5 is reduced. In order to detect, it is necessary to recount the number of image formation from the beginning. Therefore, when a new developing unit 5 in which the toner cartridge 9 is attached to the unit main body 8 is attached to the image forming apparatus main body, development up to that time is performed by reading the shipment status data by the reading means on the image forming apparatus main body side. Data on the number of image formations by the unit is initialized. The counter is reset. As a result, the number of times of image formation by the new development unit 5 can be automatically counted without the user or the service person performing a counter reset operation, and the lifetime can be detected correctly.
[0034]
FIG. 6 is a flowchart for explaining the operation of the developing unit described above. First, new data is written into the non-volatile memory 17 at the development unit manufacturing factory (S1). At this time, when the toner cartridge 9 is assembled to the unit main body 8 and shipped as the developing unit 5, shipping status data is further written in the nonvolatile memory 17. Such a non-volatile memory 17 is mounted on the toner cartridge 9, and the toner cartridge alone or the developing unit 5 in which the toner cartridge is incorporated in the unit main body 8 is shipped from the factory. Next, the toner cartridge 9 is set in the unit main body 8 mounted on the image forming apparatus main body, or the entire developing unit 5 is mounted on the image forming apparatus main body. As a result, the stored contents of the nonvolatile memory 17 are read by the reading means provided in the image forming apparatus main body. At this time, the toner cartridge 9 is independent from the unit main body 8 mounted on the image forming apparatus main body. When the toner cartridge 9 is set in step S4, it is detected that the toner cartridge 9 is new (S2, S3), and an initial replenishment operation is executed (S4). When the developing unit 5 incorporating the toner cartridge 9 is set in the main body of the image forming apparatus, a new developing unit is detected by reading the shipping status data (S2, S5), and the number of times of image formation by the developing unit is determined. Initialized (S6), an initial mass supply operation is executed (S7).
[0035]
In the example described above, the initial replenishment operation, the initial mass replenishment operation, and the initialization of the image formation frequency data are configured to be automatically performed with the mounting of the toner cartridge or the developing unit. It is also possible to configure such that at least one of the above is executed by a manual operation of a user or a service person. For example, after the front door of the main body of the image forming apparatus is opened and the entire toner cartridge 9 or the developing unit 5 is replaced, before the front door is closed, the user presses a predetermined key on the operation unit. The replenishment operation, the initial large-scale replenishment operation, or the initialization of the image forming frequency data is configured. With this configuration, for example, when an empty toner cartridge removed from the main body of the image forming apparatus is refilled with toner, but a toner cartridge for which data has not been newly written in the nonvolatile memory 17 is set, Since no new data is written in the nonvolatile memory 17, the initial replenishment operation is not automatically performed. Even in such a case, the initial replenishment operation can be executed by the user pressing the key manually. In addition, the user can perform this operation at an arbitrary timing.
[0036]
As known per se, it is also possible to write predetermined data in the nonvolatile memory 17 of the developing unit 5 set in the image forming apparatus main body.
[0037]
In the image forming apparatus shown in FIG. 1, since only a monochromatic toner image is formed on the photosensitive member 1, the developing unit 5 is always kept in the position shown in FIG. On the other hand, as shown in FIG. 7, the first to fourth developing units 5Y, 5M, 5C, and 5BK, which respectively accommodate yellow toner, magenta toner, cyan toner, and black toner, are placed on the belt-shaped photoconductor 1. When the developing units are used alternately, the developing units may be operated between the developing position and the retracted position. That is, each of the first to fourth developing units 5Y, 5M, 5C, and 5BK forms a developing position when the toner image is formed on the photosensitive member 1, and a retracted position that is farther from the photosensitive member 1 than the developing position. It is supported so as to be movable between the two. FIG. 7 shows a state in which the first developing unit 5Y occupies the developing position and the second to fourth developing units 5M, 5C, and 5BK occupy the retracted position.
[0038]
First, a first electrostatic latent image is formed on the photoconductor 1, and this latent image is visualized as a yellow toner image by the first developing unit 5Y that has occupied the developing position, and the toner image is illustrated. It is transferred to an intermediate transfer member that is not. Next, a second electrostatic latent image is formed on the photoconductor 1, and this electrostatic latent image is visualized as a magenta toner image by the second developing unit 5M occupying the development position. At this time, the other developing units 5Y, 5C, 5BK occupy the retracted positions. This magenta toner image is also transferred onto the intermediate transfer member so as to overlap the yellow toner image. Similarly, a cyan toner image and a black toner image are sequentially formed on the photosensitive member by the third and fourth developing units 5C and 5BK, and these are sequentially transferred onto the intermediate transfer member. Next, the superposed toner image on the intermediate transfer member is collectively transferred onto a transfer sheet (not shown), and the transferred toner image is fixed by a fixing device (not shown).
[0039]
As described above, when the developing unit is supported so as to be movable between the developing position and the retracted position, data access to the nonvolatile memory 17, that is, the data is not performed at a time other than when the developing unit is moving. It is preferable to be configured to read and write. This is because if the data access is performed when the developing unit is moved, the data access may not be performed correctly due to an impact accompanying the movement. It is particularly preferable that a certain time is taken after the development unit completes the movement and the data access is performed after the development unit becomes stable. In this way, data reliability can be increased.
[0040]
FIG. 8 is a block configuration diagram of an image forming apparatus including the above-described reading unit. In FIG. 8, 20 is a ROM storing a basic program as an image forming apparatus, a processing program, and the like, 21 is a CPU that controls each part of the image forming apparatus according to the program in the ROM 20, and 23 is a work area. A RAM which is formed and stores various data necessary for controlling the image forming apparatus, 24 is a scanner for reading a document, and 25 is a plotter for printing a copy or a received signal. 26 is an operation / display control unit that inputs an operation from the user and transmits information to the user. 27 is a communication control unit (CCU) that exchanges facsimile control signals with the counterpart image forming apparatus and executes a facsimile communication procedure. , 28 is a modem that modulates the transmission signal and demodulates the reception signal, 30 is a coding / decoding unit (DCR) that codes the image information according to a predetermined coding method, and decodes the coded image information. , 31 is a network control unit (NCU) that controls the communication line, 29 is a SAF (Store and Forward) memory that stores images, 33 is a toner cartridge and developing unit detection, initial supply operation, and initial mass supply operation. It is a unit control unit. The above means are connected to each other by a bus 32.
【The invention's effect】
[0041]
According to the present invention, when a new toner cartridge is mounted, it is possible to execute the initial replenishment operation without breaking the detection piece of the toner cartridge.
[Brief description of the drawings]
FIG. 1 is a partial cross-sectional schematic diagram illustrating an example of an image forming apparatus.
FIG. 2 is an enlarged cross-sectional view of a developing unit.
FIG. 3 is a cross-sectional view showing a state when toner in the toner cartridge runs out.
FIG. 4 is a cross-sectional view showing a state when a new toner cartridge is mounted on a unit main body.
FIG. 5 is a cross-sectional view illustrating a state when a new developing unit is mounted on the image forming apparatus main body.
FIG. 6 is a flowchart showing an operation when the developing unit or the toner cartridge is replaced.
FIG. 7 is a diagram illustrating a developing unit that operates between a developing position and a retracted position.
FIG. 8 is a control block diagram of the image forming apparatus.
[Explanation of symbols]
5 Development unit
5Y development unit
5M development unit
5C Development unit
5BK development unit
8 Unit body
9 Toner cartridge
10 Toner reservoir
11 Unit case
17 Nonvolatile memory
T Toner
T1 toner

Claims (5)

  A unit that includes a unit case having a toner reservoir therein and a toner carrier that carries the toner contained in the toner reservoir and transports the toner to the development area, and is detachably mounted on the image forming apparatus main body. And a toner cartridge containing toner to be replenished in a toner storage portion of the unit main body, wherein the toner cartridge is detachably attached to the unit main body. A non-volatile memory in which new data indicating that the cartridge is new is written in advance, and a new toner cartridge is attached to the unit main body attached to the image forming apparatus main body, and the image forming apparatus main body side When reading the stored contents of the nonvolatile memory by reading means, the new data When the new data is read, the toner is replenished from the toner cartridge to the toner storage portion storing a smaller amount of toner than the predetermined amount, and a predetermined amount of toner is stored in the toner storage portion. The shipment status data indicating that the toner cartridge is shipped in a state where it is mounted on the unit body is written in the nonvolatile memory in advance, and the unit is shipped at the time of shipment. When a developing unit in which a toner cartridge is mounted on the main body and no toner is present in the toner storage portion is mounted on the main body of the image forming apparatus and the storage content of the nonvolatile memory is read by the reading unit, the shipment status data Is erased, and the shipment status data is read, whereby the initial replenishment operation Control is performed so that an initial large-scale replenishment operation for replenishing a larger amount of toner from the toner cartridge to the toner storage unit and storing the predetermined amount of toner in the toner storage unit is performed. Development unit.   An image forming apparatus comprising: the developing unit according to claim 1; and an image carrier on which an electrostatic latent image visualized as a toner image is formed by the developing unit.   When a new development unit with a toner cartridge attached to the unit main body is attached to the image forming apparatus main body, the number of times of image formation by the developing unit so far is performed by reading the shipment status data by the reading means on the image forming apparatus main body side The image forming apparatus according to claim 2, wherein the data is initialized.   4. The image forming apparatus according to claim 2, wherein at least one of the initial replenishing operation, the initial mass replenishing operation, and the initialization of the image forming frequency data can be executed by a manual operation.   The developing unit is supported so as to be movable between a developing position for forming a toner image on the image carrier and a retracted position that is farther from the image carrier than the developing position. 5. The image forming apparatus according to claim 2, wherein data access to the nonvolatile memory is performed at a time other than when the data is being stored.

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