JP2015003438A - Image formation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image formation device that ensures data about the amounts of components used memorized in a non-volatile memory until the data reaches an estimated amounts of the components used.SOLUTION: The image formation device comprises a plurality of cartridges, which have a non-volatile memory 7 and perform image formation, and a CPU 200 that controls rewriting of the non-volatile memory 7. The non-volatile memory 7 comprises a first group that stores data about corresponding cartridges and a second group that stores data different from the data of the first group. The CPU 200 determines whether rewriting of the data of the second group is performed or not according to the rewriting frequency of the non-volatile memory 7 calculated based on the data of the first group and the second group.

Description

  The present invention relates to an image forming apparatus equipped with a non-volatile memory such as a printer, a copying machine, or a facsimile.

  In recent years, in an image forming apparatus, for example, measurement is performed for each item such as the number of printed sheets and a time during which a component is driven. The measured value is stored in a non-volatile memory such as EEPROM (registered trademark) (Electrically Erasable Programmable ROM). Then, with reference to this stored measurement value, maintenance such as replacement or repair of components is performed, and image forming conditions are set so that an optimum image quality can be obtained based on usage such as operation time of components. Are adjusted. The EEPROM (registered trademark) used as the nonvolatile memory is an element having a limit on the number of rewrites, and the limit on the number of rewrites is said to be, for example, about 10,000 to 100,000. If the rewrite limit number of the non-volatile memory is exceeded, data writing failure or data destruction occurs, and the data contents stored in the non-volatile memory cannot be guaranteed. Therefore, a method of controlling the nonvolatile memory so as not to exceed the rewrite limit number has been proposed.

  For example, in Patent Document 1, write count data is stored for each rewrite unit storage area, the write count data is counted up for each write process, and if the write count exceeds a predetermined value, write prohibition to the storage area is prohibited. Controls to determine have been proposed. As for the next data writing, the data can be written with high reliability by changing the storage area of the rewriting unit to another storage area and storing the data. For example, in Patent Document 2, a plurality of storage areas for storing predetermined data are provided, a pointer for specifying the storage area is provided, and when the number of times data is rewritten in a single storage area reaches a predetermined value, the storage area indicated by the pointer is set. Controls to change have been proposed.

  Further, for example, in Patent Document 3, in order to reduce the number of times of writing to the nonvolatile memory, the nonvolatile memory is used after a predetermined amount of data stored in the nonvolatile memory is added or when the power supply to the apparatus main body is turned off. Controls for rewriting memory have been proposed. By controlling the timing of rewriting the nonvolatile memory so that the number of times of rewriting of the nonvolatile memory does not exceed the number of times of rewriting up to the expected usage of the system and components equipped with the nonvolatile memory, The reliability of the data stored in the nonvolatile memory is ensured. For example, in Patent Document 4, when an image is formed using only a specific cartridge in an image forming apparatus including a plurality of cartridges having a nonvolatile memory, the nonvolatile memory of another cartridge is used. A configuration for rewriting is also proposed.

JP-A 63-234500 JP-A-6-138730 JP-A-5-249769 JP 2001-215862 A

  However, the above-described conventional example has the following problems. That is, when a plurality of areas for storing predetermined data are provided in order to prevent the number of times of rewriting of the nonvolatile memory from exceeding the number of times of rewriting, there is a problem that a required storage area of the nonvolatile memory increases. An increase in the storage capacity of the nonvolatile memory leads to an increase in cost. Even if the timing for rewriting the nonvolatile memory is controlled, it may be difficult to control the number of times the nonvolatile memory is rewritten to less than the rewrite limit number. For example, a system or component with a non-volatile memory is provided with a storage area for storing other data in addition to the system or component usage data, and the system or component with a non-volatile memory is not used However, this is a case where the nonvolatile memory is rewritten. That is, in an image forming apparatus that includes a plurality of cartridges for image formation and each cartridge is equipped with a nonvolatile memory, when performing image formation with only a specific cartridge, the nonvolatile memory of the cartridge that is not used for image formation This is a case where data is rewritten. The image forming apparatus having such a configuration has been proposed in Patent Document 4 described above. However, since the number of times of rewriting of the nonvolatile memory may be larger than the number of times of rewriting, data on the amount of use of the cartridge is guaranteed. It may not happen. As a result, there are problems that notification of the replacement time of the cartridge and stable image forming operation cannot be performed.

  The present invention has been made under such circumstances, and an object of the present invention is to guarantee data on the usage amount of a component stored in a nonvolatile memory until the expected usage amount of the component is reached. .

  In order to solve the above-described problems, the present invention is configured as follows.

  (1) An image forming apparatus including a plurality of image forming units having a non-volatile memory for image formation, and a control unit for controlling rewriting of the non-volatile memory, wherein the non-volatile memory corresponds to A first group for storing data of the image forming means, and a second group for storing data different from the data of the first group, and the control means includes the first group and An image forming apparatus comprising: determining whether to rewrite data of the second group according to the number of times of rewriting of the nonvolatile memory calculated based on the data of the second group.

  According to the present invention, it is possible to guarantee the data related to the usage amount of the component stored in the nonvolatile memory until reaching the assumed usage amount of the component.

1 is a longitudinal sectional view illustrating the overall configuration of an image forming apparatus according to first to third embodiments. 1 is a block diagram illustrating a configuration of an image forming apparatus according to first to third embodiments. Data structure diagram of nonvolatile memory of Examples 1 and 2 The figure which shows the group definition of the data of the non-volatile memory of Example 1,2. 7 is a flowchart illustrating a control sequence during image formation according to the first and second embodiments. 7 is a flowchart showing a control sequence during rewriting of the nonvolatile memory according to the first embodiment. 9 is a flowchart showing a control sequence during rewriting of the nonvolatile memory according to the second embodiment. The figure which shows the data structure and group definition of the non-volatile memory of Example 3. 9 is a flowchart illustrating a control sequence during rewriting of the nonvolatile memory according to the third embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[Entire configuration of image forming apparatus]
First, the overall configuration of the image forming apparatus that controls the nonvolatile memory according to the first embodiment will be described with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view showing the overall configuration of the image forming apparatus 100. FIG. 1 (a) is a color image forming operation which is a second image forming mode, and FIG. 1 (b) is a first image forming operation. 1 is a longitudinal sectional view showing an overall configuration of an image forming apparatus 100 during a monochrome image forming operation that is a mode. FIG.

  The image forming apparatus 100 includes four photosensitive drums 1 (1Y, 1M, 1C, 1K), and is driven to rotate counterclockwise in FIG. 1 by transmitting a driving force from a driving motor (not shown). Is done. The followings are arranged around each photosensitive drum 1 in order according to the rotation direction. First, a charging roller 2 (2Y, 2M, 2C, 2K) for uniformly charging the surface of the photosensitive drum 1 is disposed, and then, a laser beam is irradiated based on the image information to electrostatically latentize on the photosensitive drum 1. An exposure device 3 (3Y, 3M, 3C, 3K) for forming an image is provided. Further, a developing roller 4 (4Y, 4M, 4C, 4K) that causes toner to adhere to the electrostatic latent image to be visualized as a toner image is disposed, and transfer that transfers the toner image on the photosensitive drum 1 to a transfer material. Rollers 5 (5Y, 5M, 5C, 5K) are disposed. The photosensitive drum 1, the charging roller 2, and the developing roller 4 are integrated, and can be attached to and detached from the image forming apparatus 100 as a cartridge 10 (10Y, 10M, 10C, 10K). Further, the cartridge 10 includes a nonvolatile memory 7 (7Y, 7M, 7C, 7K). Further, a developing separation plate 16 that drives the developing roller 4 (4Y, 4M, 4C) and the photosensitive drum 1 (1Y, 1M, 1C) to a contact position and a separation position is provided.

  The transfer material fed from the paper feed cassettes 20a and 20b, which are supply means for supplying the transfer material, is transported to the image forming unit by the transfer transport belt 11, and each color toner image is sequentially transferred to the transfer material to be a color image. Is formed. The toner image on the transfer material is pressed and heated by the fixing device 50 and fixed on the transfer material, and then the transfer material is discharged out of the apparatus by the discharge roller pair 26.

[Control block of image forming apparatus]
FIG. 2 is a block diagram illustrating a configuration of the image forming apparatus 100. The CPU 200 in FIG. 2 controls the entire image forming apparatus, including control related to image formation such as control of the image forming unit and transfer material conveyance control. The CPU 200 has a timer function for measuring time. Further, the image forming apparatus 100 includes a ROM 201 and a RAM 202. A ROM 201 stores a program and data for controlling the image forming apparatus 100, and a RAM 202 is a memory used for temporarily storing information by a control program executed by the CPU 200. The CPU 200 reads out a program stored in the ROM 201 and controls an image forming control unit 210, a paper feed / conveying control unit 211, and a fixing control unit 212, which will be described later, to perform an image forming operation. Further, the CPU 200 controls the nonvolatile memory control circuit 205 to control the nonvolatile memory 7 (7Y, 7M, 7C, 7K) (hereinafter also simply referred to as “memory 7 (7Y, 7M, 7C, 7K)”). Performs data read and write control. Note that symbols Y, M, C, and K at the end of the symbols indicate the toner colors of the cartridges, and indicate yellow, magenta, cyan, and black, respectively. As shown in FIG. 1, the configuration of each cartridge is the same, and in the following description, the description of Y, M, C, and K will be omitted and the memory 7 will be described unless otherwise required.

[Image formation control unit]
In FIG. 1, a photosensitive drum 1 is configured by applying an organic optical conductor layer (OPC layer) to the outer peripheral surface of an aluminum cylinder having a diameter of 30 mm. Both ends of the photosensitive drum 1 are rotatably supported by flanges, and a driving force is transmitted to one end from a driving motor (not shown) to rotate counterclockwise as shown in FIG. Driven. The charging roller 2 is a conductive roller formed in the shape of a roller. The roller is brought into contact with the surface of the photosensitive drum 1 and a charging voltage is applied by a high voltage power source (not shown) so that the surface of the photosensitive drum 1 is made uniform. Charge. The exposure device 3 forms an electrostatic latent image on the photosensitive drum 1 by irradiating a laser beam on the basis of image information with a drive circuit (not shown). The developing roller 4 is positioned in a toner storage portion storing toner of each color of yellow (Y), magenta (M), cyan (C), and black (K), and is adjacent to the surface of the photosensitive drum 1 and is not shown. It is rotationally driven by the drive unit. Then, a toner image is developed by applying a developing voltage to the developing roller 4 from a high voltage power source (not shown). Inside the transfer / conveyance belt 11, transfer rollers 5 that are in contact with the transfer / conveyance belt 11 are arranged side by side corresponding to the four photosensitive drums 1. These transfer rollers 5 are connected to a high voltage power source (not shown), and positive charges are transferred from the transfer rollers 5 to a transfer material conveyed by a paper feed conveyance control unit 211 (described later) via a transfer conveyance belt 11. Applied. As a result, the negative toner image on the photosensitive drum 1 is sequentially transferred to the transfer material in contact with the photosensitive drum 1, and a color image is formed on the transfer material.

[Paper Feed Control Unit]
The paper feeding / conveying control unit 211 is located in the vicinity of the two paper feeding cassettes 20a and 20b for storing the transfer material and the paper feeding cassette 20, and the semi-moon pickup rollers 21a and 21b for feeding the transfer material by rotational driving. It is composed of The paper feed cassette 20a is also called a paper feed cassette a, and the paper feed cassette 20b is also called a paper feed cassette b. The pickup roller 21a is a pickup roller for the paper feed cassette a, and the pickup roller 21b is a pickup roller for the paper feed cassette b. Further, the paper feeding / conveying control unit 211 includes a feeding roller pair 25 and a paper discharge roller pair 26 that convey the transfer material, a transfer conveying belt 11 that electrostatically adsorbs and conveys the transfer material, and a driving roller that drives the transfer conveying belt. 12, a driven roller 13 (13 a, 13 b, 13 c) and a suction roller 15. The suction roller 15 holds the transfer material together with the transfer conveyance belt 11 and adsorbs the transfer material to the transfer conveyance belt 11.

The transfer material stored in the paper feed cassettes 20 a and 20 b is picked up by the rotational driving of the pickup rollers 21 a and 21 b and is fed to the transfer conveyance belt 11 by the feed roller pair 25. The transfer conveyance belt 11 is stretched and supported by four rollers, that is, a driving roller 12 and driven rollers 13 a, 13 b, and 13 c, and is disposed to face all the photosensitive drums 1. This transfer / conveying belt 11 is composed of an endless film-like member having a thickness of 100 to 150 μm and having a volume resistivity of 10 ¹⁰ to 10 ¹⁴ Ω · cm. The transfer conveyance belt 11 is circulated and moved by a driving roller 12 so as to electrostatically attract the transfer material to the outer peripheral surface facing the photosensitive drum 1 and bring the transfer material into contact with the photosensitive drum 1. As a result, the transfer material is conveyed to the transfer position of each transfer roller 5 by the transfer conveyance belt 11, and the toner image on the photosensitive drum 1 is transferred to the transfer material. A suction power source (not shown) is connected to the suction roller 15, and an electrostatic suction force is generated on both the transfer conveyance belt 11 and the transfer material by applying a voltage to the suction roller 15. The toner image transferred to the transfer material is conveyed to a fixing control unit 212 described later and fixed to the transfer material, and the transfer material is discharged out of the apparatus by the rotation of the discharge roller pair 26.

[Fixing control unit]
The fixing controller 212 includes a pressure roller 51, a fixing roller 52, and a fixing device 50 having a heater 53 inside the fixing roller 52. The pressure roller 51 is rotationally driven by a driving unit (not shown), and the fixing roller 52 is also rotationally driven accordingly. Further, a heater 53 (not shown) heats the heater 53 inside the fixing roller 52 to keep the fixing roller 52 at a predetermined temperature. When the transfer material on which the toner image is formed is nipped and conveyed between the fixing roller 52 and the pressure roller 51 while the temperature of the fixing roller 52 is controlled, the toner image on the transfer material is transferred by heating and pressure. Fixed to the material.

[Configuration for color image formation and monochrome image formation]
A configuration of the image forming apparatus 100 when performing color image formation and monochrome image formation will be described. When color image formation is performed, as shown in FIG. 1A, the developing separation plate 16 is moved to a position where the four photosensitive drums 1 and the developing roller 4 come into contact with each other by a driving unit (not shown). Toner images are formed on the photosensitive drums 1 for all four colors. On the other hand, when a monochrome image is formed using a specific color, the cartridges 10Y, 10M, and 10C dedicated to color image formation (hereinafter referred to as “color cartridge 10”) are not used, and the black cartridge 10K is used. Image formation using only Therefore, at the time of monochrome image formation, the developing separation plate 16 is driven, and only the photosensitive drum 1K and the developing roller 4K are brought into contact with each other to perform the image forming operation. Note that the photosensitive drums 1 of all the cartridges 10 are also rotationally driven during monochrome image formation in order to convey the transfer material.

[Configuration of cartridge and non-volatile memory]
As shown in FIGS. 1 and 2, all the cartridges 10 are each equipped with a nonvolatile memory 7 (7Y, 7M, 7C, 7K). The cartridge 10 is detachable from the image forming apparatus 100. When the cartridge 10 is attached to the image forming apparatus 100, the nonvolatile memory 7 and the nonvolatile memory control circuit 205 of the image forming apparatus 100 (hereinafter referred to as “control circuit 205”). (Also called). The non-volatile memory 7 is an EEPROM (Electrically Erasable Programmable ROM) which is a non-volatile semiconductor memory. The nonvolatile memory 7 reads and writes data via the control circuit 205 that has received an instruction from the CPU 200. The nonvolatile memory 7 has a 32-byte memory space as a data area. Reading and writing of the data area are performed in units of 4 bytes, and memory addresses for accessing the memory space are addresses 00 to 07. Allocated. Further, as an electrical characteristic of the nonvolatile memory 7, a rewrite operation of 100,000 times is guaranteed for each memory address as a guaranteed number of times.

  Next, FIG. 3 shows a data structure of the nonvolatile memory 7. FIG. 3A shows the memory addresses in the nonvolatile memories 7Y, 7M, and 7C of the color dedicated cartridge 10 and the names of data stored in the corresponding addresses. Similarly, FIG. 3B shows the memory addresses in the nonvolatile memory 7K of the cartridge 10K and the names of data stored in the corresponding addresses. As shown in FIG. 3, the non-volatile memories 7Y, 7M, and 7C of the color dedicated cartridge 10 use a 32-byte memory space. However, in the non-volatile memory 7K of the cartridge 10K, the memory addresses 05 and 06 are Unused.

  Next, data stored at each memory address will be described. At address 00, “toner filling amount” is stored. The toner filling amount refers to the amount of toner stored in the toner storage portion of the cartridge 10 and is written in a factory that produces the cartridge 10. In this embodiment, for example, a value indicating 200 g is written in the toner filling amount.

  The address 01 stores “replacement guide driving time” which is a guide for replacing the cartridge 10. The replacement guide drive time is a drive time threshold value that serves as a guide for replacement of the cartridge 10 in order to notify the user that there is a possibility that stable image forming operation may not be possible due to wear of the components constituting the cartridge 10. Has been written. In the present embodiment, the drive time that is a guide for replacement refers to the time that the cartridge 10 is driven with the developing roller 4 in contact with the photosensitive drum 1. When the cartridge 10 is driven with the developing roller 4 in contact with the photosensitive drum 1, the OPC layer of the photosensitive drum 1 is scraped off. When the OPC layer is shaved and thinned, charging of the surface of the photosensitive drum 1, formation of an electrostatic latent image, and development of a toner image become unstable. As the driving time that is a guide for cartridge replacement, a threshold value corresponding to the photosensitive drum 1 to be used is written in a factory that produces the cartridge 10. In this embodiment, for example, a value indicating 50,000 seconds is written in the replacement guide driving time.

  Address 02 stores “toner usage amount integrated value”. The toner use amount integrated value indicates an integrated value of the toner amount consumed by performing the image forming operation using the cartridge 10. The toner use amount integrated value is a value obtained by calculating the toner use amount for each transfer material used for image formation based on the time when the exposure device 3 irradiates the photosensitive drum 1 with the laser beam, and integrating the calculated values. It is. In this embodiment, the CPU 200 measures the irradiation time of the laser beam of the exposure apparatus 3 using a timer. Then, the CPU 200 calculates the toner usage amount per transfer material, assuming that the toner usage amount per 10 msec (millisecond) of the laser beam irradiation is 2 mg. If the color of the corresponding cartridge 10 is not included in the image to be formed, the toner usage amount integrated value of the nonvolatile memory 7 of the corresponding cartridge 10 does not increase. The toner use amount integrated value is used to notify the user that the toner amount of the cartridge 10 may be zero.

  Address 03 stores a “driving time integrated value” obtained by integrating the time during which the cartridge 10 is driven in a state where the developing roller 4 is in contact with the photosensitive drum 1. The drive time integrated value is used to notify the user that there is a possibility that a stable image forming operation may not be possible due to the consumption of the parts constituting the cartridge 10. A value corresponding to the length of the transfer material used in image formation in the transport direction is added to the driving time integrated value. The CPU 200 measures the time during which the cartridge 10 is being driven with the developing roller 4 in contact with the photosensitive drum 1 using a timer. In this embodiment, for example, the minimum length in the transport direction of a transfer material capable of forming an image is 100 mm, and the time for which the cartridge 10 is driven in that case is 2 seconds. The address 04 stores “image forming number”, which is the number of transfer materials on which an image is formed using the cartridge 10, in units of one sheet.

  The address 05 stores “monochrome image formation number”, which is the number of transfer materials on which a monochrome image is formed, in units of one sheet. As described above, at the time of monochrome image formation, the developing roller 4 of the color cartridge 10 and the photosensitive drum 1 are separated from each other by the developing separation plate 16, but the photosensitive drum 1 continues to be rotationally driven to convey the transfer material. . The color cartridge 10 is not used for image formation, but is driven for transporting a transfer material. Therefore, for maintenance / maintenance when the cartridge 10 or the image forming apparatus 100 fails or trouble occurs. In this embodiment, the operation history is stored. Therefore, the number of monochrome images formed is stored only in the non-volatile memory 7 of the color dedicated cartridge 10, and the address 05 of the non-volatile memory 7K of the cartridge 10K containing black toner is not used.

  In addition, “monochrome driving time integrated value” that is an integrated value of the driving time of the cartridge 10K at the time of monochrome image formation is stored in the address 06 for the same reason as the address 05. The monochrome driving time integrated value is stored only in the non-volatile memory 7 of the color dedicated cartridge 10, and the address 06 of the non-volatile memory 7K of the cartridge 10K containing black toner is not used. The address 07 stores checksum data that is the total value of the data stored in the addresses 00 to 06. The checksum data is used to confirm that the information in the nonvolatile memory 7 has no error.

  Next, data that is updated in the nonvolatile memory 7 in accordance with the color image forming operation and the monochrome image forming operation will be described. During the color image forming operation, the toner use amount integrated value (address 02), the drive time integrated value (address 03), and the number of formed images (address 04) are updated in the nonvolatile memories 7 of all the cartridges 10. On the other hand, at the time of monochrome image formation, the toner use amount integrated value (address 02), the drive time integrated value (address 03), and the number of formed images (address 04) are updated in the nonvolatile memory 7K of the cartridge 10K. In the nonvolatile memories 7Y, 7C, and 7M of the color dedicated cartridge 10, the number of monochrome images formed (address 05) and the monochrome driving time integrated value (address 06) are updated during monochrome image formation.

  Further, the checksum data (address 07) is updated both when a color image is formed and when a monochrome image is formed. Therefore, when there are many monochrome image forming operations, there is a possibility that the number of rewrites of the address 07 for storing the checksum data of the nonvolatile memory 7 of the color dedicated cartridge 10 will exceed the number of rewrite limits of the nonvolatile memory 7. is there. If the number of times of rewriting of the nonvolatile memory 7 exceeds the number of times of rewriting, data writing failure or data destruction occurs, and the data of the nonvolatile memory 7 cannot be guaranteed. As a result, based on the data stored in the non-volatile memory 7, it becomes impossible to notify the user of a message regarding the toner amount of the cartridge 10 and the consumption of the components. Therefore, for example, by using a data structure in which checksum data is provided for each of data to be updated at the time of color image forming operation and data to be updated at the time of monochrome image formation, the number of rewrites of addresses storing checksum data can be reduced. Can do. This reduces the possibility that the number of rewrites of the address 07 for storing the checksum data will exceed the number of rewrite limits of the non-volatile memory 7, but the memory capacity of the non-volatile memory 7 for storing the checksum data Will increase.

[Rewrite control of non-volatile memory]
Next, rewrite control of the nonvolatile memory, which is a feature of the present embodiment, will be described. FIG. 4 is a diagram showing a group definition of data stored in the nonvolatile memory 7. 4A shows a group definition of data stored in the non-volatile memory 7 (7Y, 7M, 7C) of the color dedicated cartridge 10, and FIG. 4B shows the non-volatile memory 7K of the cartridge 10K. It is a figure which shows the group definition of the data to memorize | store.

  As shown in FIG. 4, the data to be rewritten (addresses 02 to 06) stored in the nonvolatile memory 7 is defined in two groups. One is a first group (hereinafter also referred to as group 1) that stores a group of information (data) related to the amount of use of the cartridge 10 itself in which the nonvolatile memory 7 is mounted. The data of the first group is composed of a toner use amount integrated value (address 02), a drive time integrated value (address 03), and the number of formed images (address 04). The other is a second group (hereinafter also referred to as group 2), which is a group for storing information groups (data) other than information relating to the usage amount of the corresponding cartridge 10 itself. The data of the second group is composed of the number of monochrome images formed (address 05) and the monochrome driving time integrated value (address 06).

  In FIG. 4, “1” and “2” in the group column indicate whether the corresponding data is the first group or the second group, respectively. Further, “not update” in the columns of “color image formation” and “monochrome image formation” indicates that the corresponding data is not updated when a color image is formed or when a monochrome image is formed. On the other hand, “update” indicates that the corresponding data is updated at the time of color image formation and monochrome image formation. The first group (addresses 02 to 04) and the second group (addresses 05 and 06) are composed of a plurality of information groups (data). Therefore, “update” means that at least one piece of data is updated.

[Control of non-volatile memory at power-on]
Next, control when the image forming apparatus 100 is turned on or when the cartridge 10 is replaced will be described. Since the method for detecting that the cartridge 10 has been replaced is a well-known technique, a detailed description thereof will be omitted here. The CPU 200 stores the data stored in the nonvolatile memory 7 of all the cartridges 10 when the power of the image forming apparatus 100 is turned on, and stores the data stored in the nonvolatile memory 7 of the corresponding cartridge 10 when detecting that the cartridge 10 has been replaced. Read the stored data. Then, the CPU 200 stores the read data in the RAM 202 as cache data of the nonvolatile memory 7. Hereinafter, the cache data refers to data in the nonvolatile memory 7 stored on the RAM 202. Then, the CPU 200 compares the checksum data calculated by summing the data at the addresses 00 to 06 read from the nonvolatile memory 7 with the checksum data read from the address 07, thereby obtaining the data in the nonvolatile memory 7. Determine if there are any abnormalities.

[Non-volatile memory rewrite control sequence during image formation]
Next, a rewrite control sequence of the nonvolatile memory 7 at the time of image formation according to the present embodiment will be described with reference to a flowchart. FIG. 5 is a flowchart illustrating a control sequence during image formation according to the present exemplary embodiment. A rewrite control sequence of the nonvolatile memory 7 at the time of image formation will be described based on the flowchart of FIG.

  In step (hereinafter referred to as “S”) 100, when a print job is input, the CPU 200 controls the image forming control unit 210, the paper feed / conveyance control unit 211, and the fixing control unit 212 described above to control one sheet (one page). The color image forming operation or the monochrome image forming operation is performed on the transfer material. Next, in S101, when the image forming operation ends, the CPU 200 updates the cache data of the nonvolatile memory 7 stored in the RAM 202 along with the image forming operation. The data updated in accordance with the image forming operation is as described above. That is, during color image formation, among the cache data in the nonvolatile memory 7 of all the cartridges 10, the toner use amount integrated value (address 02), the drive time integrated value (address 03), the number of images formed (address 04), the checksum Data (address 07) is updated. On the other hand, during monochrome image formation, the number of monochrome images formed (address 05), the monochrome drive time integrated value (address 06), and the checksum data (address 07) are updated among the cache data in the nonvolatile memory 7 of the color cartridge 10. Is done. Further, for the cache data in the nonvolatile memory 7K of the cartridge 10K, the toner usage amount integrated value (address 02), the driving time integrated value (address 03), the number of images formed (address 04), and the checksum data (address 07) are stored. Updated. Next, in S <b> 102, the CPU 200 performs rewriting control of the nonvolatile memory 7 of the corresponding cartridge 10. Details of the rewrite control of the nonvolatile memory 7 will be described later.

  Subsequently, when the rewrite control of the nonvolatile memory 7 is completed, the user is notified of whether or not the cartridge 10 needs to be replaced based on the data stored in the nonvolatile memory 7 of the cartridge 10. First, in S103, the CPU 200 determines whether toner is present. Specifically, the CPU 200 compares the toner use amount integrated value (address 02) stored in the nonvolatile memory 7 of the corresponding cartridge 10 with the toner filling amount (address 00) to determine the presence or absence of toner. To do. If the CPU 200 determines that there is no toner, that is, if the toner use amount integrated value is larger than the toner filling amount, the process proceeds to S104, and if it is determined that there is toner, the process proceeds to S105. In S <b> 104, the CPU 200 displays a message indicating that there is a possibility that the toner in the corresponding cartridge 10 has run out (message without toner) on a display panel (not shown).

  In S105, the CPU 200 compares the replacement guide drive time (address 01) stored in the nonvolatile memory 7 of the corresponding cartridge 10 with the drive time integrated value (address 03), and the drive time of the cartridge 10 is changed. It is determined whether or not the target time has been reached. If the CPU 200 determines that the replacement standard time has been reached, that is, if the drive time integrated value is larger than the replacement standard drive time, the CPU 200 proceeds to S106 and has not reached the replacement standard time. If it is determined, the process proceeds to S107. In S <b> 106, the CPU 200 displays a message (message related to cartridge replacement) on the display panel (not shown) that there is a possibility that a stable image forming operation cannot be performed due to consumption of the components of the cartridge 10.

  In S107, the CPU 200 determines whether or not the processing from S102 to S106 has been completed for all the cartridges 10. If the CPU 200 determines that the processing has been completed for all cartridges, the CPU 200 proceeds to S108 and determines that the processing has not ended. If so, the process returns to S102. In S108, the CPU 200 determines whether or not the print job has been completed. If it is determined that the print job has not ended, the process returns to S100, and if it is determined that the print job has ended, the process ends. In S103 and S105, the CPU 200 reads data stored in the nonvolatile memory 7 and performs processing. However, the CPU 200 may perform processing using cache data on the RAM 202 having the same data content.

  Next, the processing contents of the rewrite control of the nonvolatile memory 7 in S102 will be described with reference to FIG. FIG. 6 is a flowchart showing a control sequence when the nonvolatile memory 7 is rewritten. In S200, the CPU 200 first reads data of an information group (addresses 02 to 04) of the first group (hereinafter referred to as “group 1” in the flowchart) of the nonvolatile memory 7 of the corresponding cartridge 10. Then, the CPU 200 compares the read data of the information group of the first group in the nonvolatile memory 7 with the cache data of the information group of the first group stored in the RAM 202, and compares the information of the information group of the first group. Determine if the data has changed. If the CPU 200 determines that the data has been changed, the process proceeds to S201. If the CPU 200 determines that the data has not been changed, the process proceeds to S202. In S <b> 201, the CPU 200 rewrites the data of the information group of the first group in the nonvolatile memory 7 of the corresponding cartridge 10 with the cache data of the RAM 202.

  In S <b> 202, the CPU 200 determines whether the target cartridge for which rewriting control of the nonvolatile memory 7 is performed is a black cartridge 10 </ b> K containing black toner. If the CPU 200 determines that the cartridge is not the cartridge 10K, the process proceeds to S203. If the CPU 200 determines that the cartridge is the cartridge 10K, it is not necessary to rewrite the information group of the second group (hereinafter referred to as “group 2” in the flowchart), and thus the process proceeds to S209.

In S203, the CPU 200 calculates the required rewrite count A (hereinafter simply referred to as “required rewrite count A”) of the data of the information group of the first group. The required number of rewrites A is the first group of the non-volatile memory 7 from the start of use of the cartridge 10 until it is determined that the toner in the cartridge 10 has run out or stable image formation is not possible due to exhaustion of components or the like. Indicates the number of times data in the information group is rewritten. The amount of toner used and the degree of consumption of the components vary depending on the usage status of the user. For this reason, in this embodiment, the number of rewrites in the case where the number of rewrites of the information group of the first group is the largest for the usage status of the user is set as the required number of rewrites A. The case where the number of times of rewriting of the information group of the first group is the largest is the case where the image forming operation with the lowest consumption of the component parts is repeated. For example, in this embodiment, toner may not be used depending on the image to be formed, as in the case of monochrome image formation. Therefore, for the determination of the degree of consumption of the components of the cartridge 10, information on the toner usage (address 00, 02) is not used, but a replacement drive time (address 01) is used. The image forming operation in which the consumption of the component parts is the lowest is an image forming operation on a transfer material having a minimum size capable of forming an image. Therefore, the required number of rewrites A can be calculated by the following equation (1).
Required number of rewritings A = {(replacement guide driving time / minimum driving time for image formation for one transfer material) / non-volatile memory rewriting frequency with respect to the number of image forming sheets} × α + β (1)

  As shown in Expression (1), the maximum number of image formations is obtained when the replacement guide drive time is divided by the minimum drive time of the cartridge 10 when forming an image for one transfer material. Furthermore, the required number of rewrites A, which is the number of rewrites of the nonvolatile memory 7, becomes the maximum value when the maximum value of the number of image formations is divided by the rewrite frequency F of the nonvolatile memory 7 with respect to the number of image formations. By the way, the grasping of the state of the cartridge 10 based on the toner use amount integrated value (address 02) and the drive time integrated value (address 03) in the nonvolatile memory 7 is determined based on the measurement value, the manufacturing variation of the cartridge 10 and the like. May not match exactly. Therefore, the necessary number of rewrites is corrected with coefficients α and β as a margin for measurement variation and manufacturing variation. The coefficient α is a coefficient for the measurement variation per transfer material, and in this embodiment, for example, α = 1.002. Further, the coefficient β is a margin for the variation of the entire required number of rewriting A, and in this embodiment, for example, β = 200.

  As described with reference to the flowchart of FIG. 5, in this embodiment, the data rewriting process of the nonvolatile memory 7 is performed every time an image of one transfer material is formed. Therefore, the data rewriting frequency F of the nonvolatile memory 7 with respect to the number of image formations in this embodiment is 1. Further, as described above, the replacement guide driving time is 50,000 seconds, and the minimum driving time of the cartridge 10 when forming an image of one transfer material is 2 seconds. Therefore, by substituting this value into the equation (1), the required number of rewrites A in this embodiment is {(50000 (seconds) / 2 (seconds)) / 1 (times)} × 1.002 + 200 = 25, 250 times.

In S204, the CPU 200 calculates the total rewrite count B (hereinafter simply referred to as “total rewrite count B”) of the data in the information group of the second group of the nonvolatile memory 7 of the cartridge 10 up to the present time, using the following formula (2 ).
Total number of rewriting times B = number of monochrome image formations (address 05) / rewriting frequency F of nonvolatile memory with respect to the number of image formations (2)
Since the data of the information group of the second group is rewritten only when monochrome image formation is performed, the number of monochrome image formation (address 05) is rewritten in the nonvolatile memory 7 with respect to the number of image formation. The value divided by the frequency F is the total number of rewriting times B.

In S <b> 205, the CPU 200 calculates a limited rewrite count C (hereinafter simply referred to as “restricted rewrite count C”) that limits the number of data update times of the information group of the second group, using the following equation (3).
Limit number of rewrites C = Limit number of rewrites of nonvolatile memory−Required number of rewrites A (3)
The limit rewrite count C is a value obtained by subtracting the required rewrite count A from the rewrite limit count of the nonvolatile memory 7. As described above, the rewrite limit number of the nonvolatile memory 7 is 100,000 times. Therefore, in this embodiment, 100,000 (times) −25,250 (times) = 74,750 times is the limited number of rewrites C.

  In S <b> 206, the CPU 200 compares the total number of rewrites B with the limit number of rewrites C, and determines whether or not data rewrite restrictions on the information group of the second group are necessary. The CPU 200 determines that the rewrite restriction of the second group is necessary when the total rewrite number B of the data of the information group of the second group is equal to or greater than the limited rewrite number C (B ≧ C) that is equal to or greater than the predetermined number of times. The data of the information group of the second group in the nonvolatile memory 7 is not rewritten, and the process proceeds to S209. On the other hand, when the total rewrite count B of the data of the information group of the second group is less than the limit rewrite count C (B <C), the CPU 200 determines that the rewrite limit of the second group is not necessary. The process proceeds to S207.

  In S207, the CPU 200 first reads data of the information group (addresses 05 and 06) of the second group of the nonvolatile memory 7 of the corresponding cartridge 10. Then, the CPU 200 compares the read data of the second group of information groups in the nonvolatile memory 7 with the cache data of the second group of information groups stored in the RAM 202, and the second group of information groups. Determine if the data has changed. If the CPU 200 determines that the data has been changed, the process proceeds to S208. If the CPU 200 determines that the data has not been changed, the process proceeds to S209. In S <b> 208, the CPU 200 rewrites the data of the information group of the second group in the nonvolatile memory 7 of the corresponding cartridge 10 with the cache data of the RAM 202.

  In S209, the CPU 200 calculates the checksum data of the nonvolatile memory 7 based on the data at addresses 00 to 06 of the nonvolatile memory 7. Then, the CPU 200 stores the calculated checksum data at the address 07 of the nonvolatile memory 7 and ends the data rewriting process of the nonvolatile memory 7 of the corresponding cartridge 10.

  As described above, in the present embodiment, the information stored in the nonvolatile memory of the cartridge of the image forming apparatus includes the first group for storing the information group regarding the usage amount of toner and components, and the information on the first group. It is divided into a second group that stores information groups different from the groups. Based on the rewrite limit number of the non-volatile memory, information on the usage amount of the component stored in the non-volatile memory, and the rewrite number of the second group, the rewrite limit of the information group of the second group Make a decision. By prioritizing the rewriting of the information group of the first group over the rewriting of the information group of the second group, the number of times of rewriting of the nonvolatile memory is at least until the amount of use of the components is assumed. Can be controlled so as not to exceed the rewrite limit number of the memory. As a result, it is possible to appropriately notify the user of the toner amount of the cartridge, the consumption status of the component of the cartridge, and the like based on the data regarding the toner and the usage amount of the component stored in the nonvolatile memory.

  In addition, since the number of times of rewriting the nonvolatile memory is calculated based on the information stored in the nonvolatile memory, a new memory space for storing the number of times of rewriting the nonvolatile memory is not required. Then, based on the calculated number of times of rewriting the nonvolatile memory, the rewriting of the nonvolatile memory can be controlled so as not to exceed the number of times of rewriting until the usage amount of the component reaches the assumed usage amount. .

  Further, for example, by storing the amount of the OPC layer removed from the photosensitive drum in a non-volatile memory, the charging voltage and the development voltage are adjusted according to the amount of the OPC layer removed. Control for adjusting the toner density to be constant can be performed. As a result, it is possible to provide a stable image at least up to an assumed amount of use of the cartridge components. Since the control for adjusting the charging voltage and the developing voltage according to the film thickness of the OPC layer of the photosensitive drum is a well-known technique, a detailed description thereof is omitted here.

  As described above, according to the present embodiment, it is possible to guarantee the data related to the usage amount of the component stored in the nonvolatile memory until the expected usage amount of the component is reached.

  In the first embodiment, the number of rewrites C that restricts the number of updates of data in the information group of the second group is changed to the number of times of rewrite restriction in the nonvolatile memory 7 and the required number of rewrites A of the data in the information group of the first group. Calculated based on In the second embodiment, a description will be given of an embodiment in which the limit rewrite count C for limiting the number of times of updating the data of the information group of the second group is set to a value more suitable for the use situation of the user. In this embodiment, the image forming apparatus 100 shown in FIGS. 1 and 2 of the first embodiment is used, and the description of the image forming apparatus 100 and the image forming operation of the image forming apparatus 100 is omitted. Further, the data structure of the nonvolatile memory 7 and the configuration relating to the group definition are the same as those in FIGS. 3 and 4 of the first embodiment.

[Rewrite control sequence of non-volatile memory]
Next, the rewrite control sequence of the nonvolatile memory 7 of this embodiment will be described. The read control of the nonvolatile memory 7 when the power of the image forming apparatus 100 is turned on or when the cartridge 10 is replaced is the same as in the first embodiment, and a description thereof is omitted. Further, the rewrite control sequence of the nonvolatile memory 7 at the time of image formation is the same as the control sequence shown in FIG. 5 of the first embodiment, and a description thereof is omitted here.

  FIG. 7 is a flowchart showing a control sequence at the time of rewriting the nonvolatile memory 7 in the present embodiment, and is a flowchart showing details of the processing in S102 of FIG. First, in S300, the CPU 200 first reads data of an information group (addresses 02 to 04) of the first group (hereinafter referred to as “group 1” in the flowchart) of the nonvolatile memory 7 of the corresponding cartridge 10. Then, the CPU 200 compares the read data of the information group of the first group in the nonvolatile memory 7 with the cache data of the information group of the first group stored in the RAM 202, and compares the information of the information group of the first group. Determine if the data has changed. If the CPU 200 determines that the data has been changed, the process proceeds to S301. If the CPU 200 determines that the information group of the first group has not been changed, the information group of the first group in the nonvolatile memory 7 is The process proceeds to S302 without rewriting. In S <b> 301, the CPU 200 rewrites the data of the first group of information in the nonvolatile memory 7 of the corresponding cartridge 10 with the cache data of the RAM 202.

  In S <b> 302, the CPU 200 determines whether the target cartridge for which the rewrite control of the nonvolatile memory 7 is performed is a black cartridge 10 </ b> K containing black toner. If the CPU 200 determines that the cartridge is not the cartridge 10K, the process proceeds to S303. If the CPU 200 determines that the cartridge is the cartridge 10K, the information group of the second group (hereinafter referred to as “group 2” in the flowchart) is rewritten. Since it is unnecessary, the process proceeds to S310.

In S303, the CPU 200 calculates the total rewrite count D (hereinafter simply referred to as “total rewrite count D”) of the data of the information group of the first group of the nonvolatile memory 7 of the cartridge 10 up to the present time, using the following formula (4 ).
Total number of rewrites D = number of formed images (address 04) ÷ rewrite frequency F of nonvolatile memory with respect to the number of formed images F (4)
The timing for rewriting the data of the information group of the first group is the timing at which the image forming operations of color image formation and monochrome image formation are performed. Therefore, the value obtained by dividing the number of image formations stored at address 04 of the nonvolatile memory 7 by the rewrite frequency F of the nonvolatile memory 7 with respect to the number of image formations is the total number of rewrites D of the data of the information group of the first group. It becomes. Also in the present embodiment, as in the first embodiment, the data rewriting process of the nonvolatile memory 7 is performed every time an image is formed on one transfer material, so the data rewriting frequency F of the nonvolatile memory 7 is 1

  In S304, the CPU 200 calculates the required number of rewrites A2 (hereinafter simply referred to as “required number of rewrites A2”) of the data of the information group of the first group. The required number of rewrites A2 is the first group of the non-volatile memory 7 from the start of use of the cartridge 10 until it is determined that the toner in the cartridge 10 runs out or stable image formation is not possible due to the consumption of components or the like. Indicates the number of times data in the information group is rewritten. Therefore, in this embodiment, the required number of rewrites A2 is the sum of the two times. One is a total rewrite count D indicating the number of times the nonvolatile memory 7 has been rewritten so far. The other is that the first group of the non-volatile memory 7 is determined until it is determined from the current state that the toner in the cartridge 10 runs out or a stable image cannot be formed due to consumption of components or the like. This is the number of times data in the information group is rewritten. As described above, the amount of toner used and the degree of consumption of the components vary depending on the usage status of the user. Therefore, the required number of rewrites A2 is calculated using the case where the number of rewrites of the data of the information group of the first group is the largest for the usage method of the user. Also in this embodiment, as in the first embodiment, the driving time is used to determine the degree of consumption of the component parts.

Therefore, the CPU 200 calculates the required rewrite count A2 by the following equation (5).
Required number of rewrites A2 = total number of rewrites D + [{(replacement guide drive time−drive time integrated value) ÷ minimum drive time for image formation for one transfer material} ÷ non-volatile memory rewrite frequency F relative to the number of image formations] × α + β (5)
As shown in Equation (5), the maximum value of the number of image formations until it is determined that stable image formation cannot be performed from the current state can be calculated as follows. That is, a value obtained by subtracting the integrated drive time value (address 03) in the current state from the replacement guide drive time (address 01) and dividing by the minimum drive time of the cartridge 10 when forming an image for one transfer material. This is the maximum number of images formed. Then, the value obtained by dividing the maximum value of the number of image formations by the rewrite frequency F of the nonvolatile memory 7 with respect to the number of image formations and the total value of the total number of rewrites D of the data of the information group of the first group are non-volatile. This is the maximum value of the number of rewrites in the memory 7. Further, considering the variation, the calculated number of times of rewriting of the nonvolatile memory 7 is corrected by the coefficients α and β as in the first embodiment. The coefficients α and β are the same as those in the first embodiment and will not be described.

In S <b> 305, the CPU 200 calculates the total rewrite count B of the data of the information group of the second group of the nonvolatile memory 7 up to the present time using the equation (2) described in the first embodiment. Next, in S306, the CPU 200 calculates the limit rewrite count C2 (hereinafter referred to as “restriction rewrite count C2”) of the data of the information group of the second group by the following equation (6).
Limit number of rewrites C2 = Non-volatile memory rewrite limit number−Required number of rewrites A2 (6)
As shown in Expression (6), the limit rewrite count C2 is a value obtained by subtracting the required rewrite count A2 of the data of the information group of the first group from the rewrite limit count of the nonvolatile memory 7.

  In S307, the CPU 200 compares the total number of rewrites B and the limit number of rewrites C2, and determines whether it is necessary to rewrite data in the information group of the second group. When the total number of rewrites B of the data of the information group of the second group is equal to or greater than the limit number of rewrites C2 (B ≧ C2), the CPU 200 determines that the rewrite limit of the second group is necessary and is non-volatile The data of the information group of the second group in the memory 7 is not rewritten, and the process proceeds to S310. On the other hand, when the total rewrite count B of the data of the information group of the second group is less than the limit rewrite count C2 (B <C2), the CPU 200 determines that the rewrite limit of the second group is not necessary. The process proceeds to S308.

  The processes in S308, S309, and S310 are the same as the processes in S207, S208, and S209 in FIG. By executing the above control sequence, data rewriting of the nonvolatile memory 7 is completed.

  As described above, in the present embodiment, the required number of rewrites A2 of the first group is stabilized from the current state based on the total number of rewrites D of the first group to date and the state of the current components. And the number of rewrites until it is determined that the image cannot be formed. Since the limit rewrite count C2 of the second group is calculated based on the required rewrite count A2 of the first group, it is a value based on the current user usage more than in the first embodiment. As a result, in the present embodiment, the required number of rewrites of the data of the information group of the first group can be set to a number more suitable for the use situation of the user.

  As described above, according to the present embodiment, it is possible to guarantee the data related to the usage amount of the component stored in the nonvolatile memory until the expected usage amount of the component is reached.

  In the present embodiment, a data structure of the nonvolatile memory 7 different from the first and second embodiments and a control method of the nonvolatile memory 7 in the group definition will be described. In this embodiment, the image forming apparatus 100 shown in FIGS. 1 and 2 of the first embodiment is used, and the description of the image forming apparatus 100 and the image forming operation of the image forming apparatus 100 is omitted.

[Configuration of non-volatile memory]
FIG. 8 shows the data structure of the nonvolatile memory 7 in this embodiment. FIG. 8A shows memory addresses in the nonvolatile memories 7Y, 7M, and 7C of the color dedicated cartridge 10, names of data stored in the corresponding addresses, group definitions, and update timings. Similarly, FIG. 8B shows the memory address in the nonvolatile memory 7K of the cartridge 10K, the name of the data stored in the corresponding address, the group definition, and the update timing. As shown in FIG. 8, the non-volatile memories 7Y, 7M, and 7C of the color dedicated cartridge 10 and the non-volatile memory 7K of the cartridge 10K use a 32-byte memory space.

  The data stored in the addresses 00 to 04 of the nonvolatile memory 7 is the same as in the first and second embodiments, and a description of the data contents is omitted. The number of sheets of transfer material fed from the paper feed cassette a, which is the paper feed cassette 20a, is stored in “sheet feed number of the paper feed cassette a” at address 05 of the nonvolatile memory 7 in units of one sheet. Similarly, the number of transfer materials fed from the paper feed cassette b, which is the paper feed cassette 20b, is stored in the unit of “sheets of paper feed cassette b” at address 06. “Paper cassette a paper feed number” and “paper cassette b paper feed number” are the same as the “monochrome image formation sheet number” described in the first embodiment, and maintenance is performed when a failure or trouble occurs in the image forming apparatus 100. -Stored as an operation history for maintenance.

[Rewrite control of non-volatile memory]
As shown in FIG. 8, the data to be rewritten (addresses 02 to 06) stored in the nonvolatile memory 7 is defined in two groups. One is a first group which is a group for storing a group of information relating to the usage amount of the cartridge 10 itself in which the nonvolatile memory 7 is mounted. The toner usage amount integrated value (address 02), the driving time integrated value (address 03). ) And the number of formed images (address 04). The other is a second group that stores a group of information other than information related to the amount of use of the corresponding cartridge 10 itself, and is a sheet feeding cassette a sheet feeding number (address 05) and sheet feeding cassette b sheet feeding. It consists of the number of sheets (address 06). Note that “1” and “2” in the group column of FIG. 8 indicate that the corresponding data belongs to the first group and the second group, respectively.

  Next, data that is updated in the nonvolatile memory 7 with the color image forming operation and the monochrome image forming operation will be described. When the color image forming operation is performed, the data in the next memory is updated in the nonvolatile memories 7 of all the cartridges 10. That is, the toner usage amount integrated value (address 02), the driving time integrated value (address 03), the number of images formed (address 04), the number of sheets fed to the sheet cassette a (address 05), or the sheet cassette b to be fed. One of the number (address 06) is updated. On the other hand, when the monochrome image forming operation is performed, the data in the next memory is updated in the nonvolatile memory 7K of the cartridge 10K. That is, the toner usage amount integrated value (address 02), the driving time integrated value (address 03), the number of images formed (address 04), the number of sheets fed to the sheet cassette a (address 05), or the sheet cassette b to be fed. One of the number (address 06) is updated. Furthermore, in the non-volatile memories 7Y, 7M, and 7C of the color dedicated cartridge 10, either the paper feed cassette a paper feed number (address 05) or the paper feed cassette b paper feed number (address 06) is updated. Further, FIG. 8 shows whether or not the data of the information group of each group is updated during the color image forming operation and the monochrome image forming operation. Note that “update” in the figure indicates that each group has one or more pieces of information (data) to be updated.

[Rewrite control sequence of non-volatile memory]
Next, the rewrite control sequence of the nonvolatile memory 7 of this embodiment will be described. The read control of the nonvolatile memory 7 when the image forming apparatus 100 is powered on or when the cartridge 10 is replaced is the same as in the first and second embodiments, and a description thereof is omitted. Further, the rewrite control sequence of the nonvolatile memory 7 at the time of image formation is the same as the control sequence shown in FIG. 5 of the first embodiment, and a description thereof is omitted here.

  FIG. 9 is a flowchart showing a control sequence at the time of rewriting the nonvolatile memory 7 in the present embodiment, and is a flowchart showing details of the processing in S102 of FIG. First, in S400, the CPU 200 reads data of an information group (addresses 02 to 04) of a first group (hereinafter referred to as “group 1” in the flowchart) of the nonvolatile memory 7 of the corresponding cartridge 10. Then, the CPU 200 compares the read data of the information group of the first group in the nonvolatile memory 7 with the cache data of the information group of the first group stored in the RAM 202, and compares the information of the information group of the first group. Determine if the data has changed. If the CPU 200 determines that the data has been changed, the process proceeds to S401. If the CPU 200 determines that the information group of the first group has not been changed, the information group of the first group in the nonvolatile memory 7 is The process proceeds to S402 without rewriting. In S <b> 401, the CPU 200 rewrites the data of the information group of the first group in the nonvolatile memory 7 of the corresponding cartridge 10 with the cache data of the RAM 202.

  In S <b> 402, the CPU 200 calculates the total rewrite count D of the data of the information group of the first group up to the present using the equation (4) described in the second embodiment. That is, the CPU 200 sets the total rewrite count D of the data of the information group of the first group of the non-volatile memory 7 of the cartridge 10 as the rewrite frequency F of the non-volatile memory 7 with respect to the image formation count (address 04). It is calculated by dividing.

  In S403, the CPU 200 calculates the required number of rewrites A2 of the data of the information group of the first group by the equation (5) described in the second embodiment. The required number of rewrites A2 is the first group of the non-volatile memory 7 from the start of use of the cartridge 10 until it is determined that the toner in the cartridge 10 runs out or stable image formation is not possible due to the consumption of components or the like. Indicates the number of times data in the information group is rewritten.

In S <b> 404, the CPU 200 determines the total number of rewrite times B <b> 2 (hereinafter referred to as “total number of rewrites B <b> 2”) of data in the information group of the second group (hereinafter referred to as “group 2” in the flowchart) of the nonvolatile memory 7. ) Is calculated by the following equation (7).
Total number of rewrites B2 = (paper feed cassette a number of paper feeds + paper feed cassette b number of paper feeds) ÷ non-volatile memory rewrite frequency F (7)

  The data of the information group of the second group is rewritten when color image formation or monochrome image formation is performed. Either one of the b paper feed numbers is incremented by 1, and the paper feed number is updated. Therefore, a value obtained by dividing the total value of the number of sheets fed in the sheet cassette a (address 05) and the number of sheets fed in the sheet cassette b (address 06) by the rewrite frequency F of the nonvolatile memory 7 with respect to the number of image formations is the total rewrite. Number of times B2. Also in this embodiment, as described in the first embodiment, the data rewriting process of the nonvolatile memory 7 of the corresponding cartridge 10 is performed every time image formation of one transfer material is performed. The data rewrite frequency F of 7 is 1.

In S <b> 405, the CPU 200 calculates the total rewrite count B <b> 3 (hereinafter referred to as “total rewrite count B <b> 3”) of only the data of the information group of the second group of the nonvolatile memory 7 up to the present using the following formula (8). .
Total number of rewrites B3 = Total number of rewrites of the second group B2—Total number of rewrites of the first group D (8)

The total number of rewrites B3 was performed when only the data of the information group of the second group was rewritten without rewriting the data of the information group of the first group when the data of the nonvolatile memory 7 was rewritten. It is the total number of times. In the present embodiment, as shown in the flowchart of FIG. 9, the data of the information group of the second group is updated when the data of the information group of the first group is updated. Therefore, the total rewrite count B3 is calculated from the total rewrite count B2 of the second group including the total rewrite count D of the data of the information group of the first group, and the total rewrite count D of the data of the information group of the first group. Can be calculated by subtracting. The total rewrite count B3 of only the data of the information group of the second group is expressed as the following formula (9) by substituting the formulas (4) and (7) described above into the formula (8). be able to.
Total number of rewrites B3 = (paper feed cassette a paper feed number + paper feed cassette b paper feed number−image formation number) ÷ nonvolatile memory rewrite frequency F with respect to image formation number F (9)
In S <b> 406, the CPU 200 calculates the limit rewrite count C <b> 2 of the data of the information group of the second group according to the formula (6) described in the second embodiment.

  In S407, the CPU 200 compares the total number of rewriting times B3 and the limited number of rewriting times C2, and determines whether it is necessary to rewrite data in the information group of the second group. When the total rewrite count B3 of the data of the information group of the second group is equal to or greater than the limit rewrite count C2 (B3 ≧ C2), the CPU 200 determines that the rewrite limit of the second group is necessary, and is non-volatile The data of the information group of the second group in the memory 7 is not rewritten, and the process proceeds to S410. On the other hand, the CPU 200 determines that the second group rewrite restriction is not necessary when the total rewrite number B3 of the data of the information group of the second group is less than the limit rewrite number C2 (B3 <C2). Then, the process proceeds to S408.

  The processing in S408, S409, and S410 is the same as the processing in S207, S208, and S209 in FIG. By executing the above control sequence, data rewriting of the nonvolatile memory 7 is completed.

  As described above, in this embodiment, the information stored in the non-volatile memory of the component of the image forming apparatus includes the first group for storing the information group regarding the usage amount of the component and the information group of the first group. It is defined as a second group that stores a different information group. Based on the rewrite limit number of the non-volatile memory, the information on the usage amount of the component stored in the non-volatile memory, and the rewrite frequency of only the information group of the second group, the information group of the second group Limit rewriting. Thus, by giving priority to rewriting of the information group of the first group over the information group of the second group, the number of times of rewriting of the nonvolatile memory is reduced until at least the amount of use of the cartridge components is assumed. It is possible to control so as not to exceed the rewrite limit number. As a result, it is possible to appropriately notify the user of the cartridge state due to the toner amount of the cartridge and the consumption of the component parts.

  Further, since the number of times of rewriting of the nonvolatile memory is calculated based on the information stored in the nonvolatile memory, a memory space for writing number data for obtaining the number of times of rewriting of the nonvolatile memory is not required. It is possible to perform control so that the number of times of rewriting of the nonvolatile memory does not exceed the number of times of rewriting until at least the usage amount of the component parts is assumed.

  As described above, according to the present embodiment, it is possible to guarantee the data related to the usage amount of the component stored in the nonvolatile memory until the expected usage amount of the component is reached.

[Other Examples]
The image forming apparatuses in Embodiments 1 to 3 described above are direct transfer systems in which a transfer material is conveyed to an image forming unit by a transfer conveyance belt, and each color toner image is sequentially transferred to the transfer material to form a color image. It was. For example, the image forming apparatuses according to the first to third embodiments are image forming apparatuses including a plurality of image forming units, and a primary transfer unit that transfers a toner image on a photosensitive drum to an intermediate transfer belt, and an intermediate transfer belt The image forming apparatus may include a secondary transfer unit that transfers the toner image to a transfer material.

  In the first to third embodiments, the number of rewrites of the information group of the first group or the second group is calculated based on the number of formed images or the number of fed sheets stored in the nonvolatile memory 7. It is not limited to the number of sheets formed and the number of sheets fed. For example, the memory of the non-volatile memory 7 is configured to store the driving time of the components, the number of on / off times of the clutch, etc., and the number of rewrites of the non-volatile memory 7 is calculated based on the driving time, the number of times of driving, etc. Even if it does, the same effect can be acquired.

  In the first to third embodiments, the nonvolatile memory 7 provided in an integrated cartridge is described as an example of the nonvolatile memory 7 mounted on the component of the image forming apparatus 100. Parts are not limited to cartridges. The same control is applied to other components constituting the image forming apparatus 100, for example, a non-volatile memory mounted on an electric board that controls the image forming apparatus 100, and a non-volatile memory mounted on a fixing device or the like. It is also possible to do. Further, the method of using the replacement guide driving time has been described as a calculation method for the case of repeating the image forming operation in which the consumption of the component parts is the lowest in order to calculate the required number of rewrites of the information group of the first group. The calculation method is not limited to the method using the driving time, and for example, the calculation can be performed using the toner usage amount integrated value. For example, in a state where the developing roller and the photosensitive drum are in contact with each other and are driven to rotate, the toner adhering to the developing roller slightly moves to the photosensitive drum, thereby causing toner consumption. The same effect can be obtained even if the configuration is such that the toner consumption amount in this case is used to calculate the image forming operation with the lowest consumption of the component parts.

  Further, in the first to third embodiments, the cartridge is described as being configured by integrating the photosensitive drum, the charging roller, and the developing roller. For example, a member including at least a storage portion that stores toner is used. May be a cartridge.

  In the present invention, a storage medium storing software program codes for realizing the functions of the embodiments is provided to a system or apparatus. This can also be achieved by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the storage medium. In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiments, and the storage medium storing the program code constitutes the present invention. As a storage medium for supplying such a program code, for example, a floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, CD-ROM, CD-R, magnetic tape, nonvolatile memory card, ROM Etc. can be used. Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also the following cases are included. That is, when the OS (operating system) running on the computer performs part or all of the actual processing based on the instruction of the program code, and the functions of the above-described embodiments are realized by the processing. Is also included.

  Furthermore, after the program code read from the storage medium is written to the memory provided in the function expansion board inserted into the computer or the function expansion unit connected to the computer, the program code is It includes the case where it is realized. That is, the case where the CPU of the function expansion board or function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.

  Further, the program code of the software that realizes the functions of the above-described embodiments is distributed through the network, thereby achieving the following. That is, it is stored in a storage means such as a hard disk or a memory of a system or apparatus, or a storage medium such as a CD-RW or CD-R. This can also be achieved by the computer (or CPU or MPU) of the system or apparatus reading and executing the program code stored in the storage means or the storage medium.

  As described above, also in the other embodiments, it is possible to guarantee the data related to the usage amount of the component stored in the nonvolatile memory until the expected usage amount of the component is reached.

7Y, 7M, 7C, 7K Non-volatile memory 10Y, 10M, 10C, 10K Cartridge 200 CPU

Claims (11)

An image forming apparatus comprising: a plurality of image forming units that have a nonvolatile memory to perform image formation; and a control unit that controls rewriting of the nonvolatile memory,
The nonvolatile memory includes a first group storing data of the corresponding image forming unit, and a second group storing data different from the data of the first group,
The control means determines whether to rewrite the data of the second group according to the number of times of rewriting of the nonvolatile memory calculated based on the data of the first group and the second group. An image forming apparatus characterized by determining.   The control means calculates the number of rewrites of only the second group from the data of the second group, and the calculated number of rewrites of only the second group stores information stored in the nonvolatile memory. 2. The image forming apparatus according to claim 1, wherein the second group of data is not rewritten when the number of times calculated based on the predetermined number of times is exceeded. The information is data relating to a predetermined usage amount of the corresponding image forming unit,
The image forming apparatus according to claim 2, wherein the control unit calculates the predetermined number of times based on the predetermined usage amount and a guaranteed number of times of rewriting of the nonvolatile memory.   The control means calculates the number of rewrites of only the first group from the data of the first group, calculates the number of rewrites of only the second group from the data of the second group, and calculates When the number of rewrites of only the second group is equal to or greater than a predetermined number calculated based on the information stored in the nonvolatile memory and the calculated number of rewrites of only the first group, 2. The image forming apparatus according to claim 1, wherein rewriting of the group data is not performed. The information is data relating to a predetermined usage amount of the corresponding image forming unit,
The control means includes the predetermined number of times of rewriting only the first group, a usage amount obtained by subtracting a usage amount from the predetermined usage amount to the present time, and a guaranteed number of times of rewriting the nonvolatile memory. The image forming apparatus according to claim 4, wherein the image forming apparatus is calculated based on:   6. The image forming apparatus according to claim 1, wherein the first group of data is data relating to a usage amount of the corresponding image forming unit. A first image forming mode for forming an image using one of the plurality of image forming units, and a second image forming mode for forming an image using the plurality of image forming units. Have
When the image forming is performed in the first image forming mode, the control unit rewrites the data of the second group of another image forming unit different from the one image forming unit, and 7. The image forming apparatus according to claim 1, wherein when the image is formed in an image forming mode, the data of the first group of the plurality of image forming units is rewritten. . A plurality of supply means for supplying a transfer material to be imaged;
The image forming apparatus according to claim 4, wherein the data of the second group is data relating to an operation history of the supply unit.   The image forming apparatus according to claim 1, wherein the nonvolatile memory is mounted on a detachable member.   The image forming apparatus according to claim 9, wherein the detachable member is a cartridge having a photosensitive drum, a charging roller, and a developing roller.   The image forming apparatus according to claim 9, wherein the detachable member is a cartridge having a storage unit that stores at least toner.

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