JP4890170B2 - Image forming apparatus and charging system for image forming apparatus - Google Patents

Description

  The present invention provides an image forming apparatus that manages consumables such as toner and a photosensitive drum while storing management data such as a life count value and a statistical count value in a storage device such as a nonvolatile memory, and is required while using the management data. The present invention relates to a charging system for an image forming apparatus that performs the above charging.

In an image recording apparatus such as an electrophotographic printer, a photosensitive drum having a photosensitive member such as an organic thin film is charged, and an electrostatic latent image is formed by irradiating the surface of the photosensitive drum with recording light generated by an LED or the like. After that, the toner is attached to the photosensitive drum to develop the electrostatic latent image, the toner image formed by the development is transferred to the paper, and the transferred toner image and the paper are pressure-bonded to the paper while applying heat. The toner image is fixed. In such an electrophotographic printer or the like, a predetermined amount of toner is accommodated in a predetermined portion (hopper) in the developing device in consideration of the convenience of replenishment or replacement of toner.

Since printing cannot be performed when the toner that is the developer is used up, the life of the developing device is reached when all the stored toner is consumed, but even if some toner remains, the remaining amount remains below a predetermined amount. When this happens, the printed image becomes faint or the toner adheres to the non-printed portion and the print quality is extremely lowered, so that the life of the developing device is substantially reached.

For this reason, a conventional electrophotographic printer or the like detects the remaining amount of toner, and issues a warning by a warning sound, a warning display, etc. when the remaining amount of toner falls below a predetermined amount. It is possible for the user to easily determine the life of the developing device before the deterioration of the toner. As a method for detecting the remaining amount of toner, a method of mechanically detecting a load during stirring of toner, monitoring data for driving an LED head, counting the number of dots to be printed, and reducing the amount of toner consumed. A method for detecting and detecting the remaining amount of toner is known.

Also, in the conventional electrophotographic printers and the like as described above, when the photosensitive drum deteriorates, the quality of the printed image is lowered. Therefore, the life of the photosensitive drum is detected, and a warning sound and display are displayed when the lifetime is reached. For example, a warning is issued so that the user can easily determine when to replace the photosensitive drum. As a method for detecting the life of the photoconductor drum, there is a method in which the rotation speed of the photoconductor drum is counted, and when this exceeds a predetermined rotation speed (life rotation speed), the life of the photoconductor drum is determined. Are known.

  In a recent development unit in which a photosensitive drum and a toner tank are integrated, when the lifetime of the development unit is detected only by the lifetime corresponding to the number of rotations of the photosensitive drum, the lifetime of the development unit corresponding to the consumption or deterioration of the toner is detected. Is not considered. In order to take these lifetimes into account, an apparatus that counts both the number of rotations of the photosensitive drum and the number of dots of data forming a latent image is known (see, for example, Patent Document 1).

JP 2001-235985 A

  The image forming apparatus as described above is provided with a statistical count value that records a life count value, a replacement count, and the like as a basis for calculating a consumption amount and remaining amount of consumables such as a process cartridge and a toner cut ridge. However, since the information must be retained even when the power of the apparatus is turned off, the information is recorded in a nonvolatile memory (EEPROM). Since the memory map in the non-volatile memory always has a fixed address arrangement, the life counter value and the statistical counter value are always updated in a predetermined area.

  However, in the case where the memory map of the non-volatile memory that is the storage destination of the data on the lifetime etc. is always arranged in a fixed area, the non-volatile memory chip itself is mounted on the control board via the socket. If the chip is removed from the substrate, the stored data can be easily referenced with a non-volatile memory writer, and if the data is analyzed, the information can be altered. . Therefore, in a system or the like in which charging is performed based on a life count value or a statistical count value obtained by accumulating the number of dots, there is a problem in that the charging function cannot be performed due to such fraudulent acts, resulting in a disadvantage.

  In view of the above technical problems, an object of the present invention is to provide an image forming apparatus capable of preventing damage caused by fraudulent acts such as rewriting data stored for life or billing. It is another object of the present invention to provide a charging system for an image forming apparatus that can prevent damage caused by fraud such as rewriting data stored for lifetime or charging.

In order to solve the above-described technical problem, the image forming apparatus of the present invention stores the consumable usage amount in each area specified by a predetermined storage address defined by a storage pattern number. Means, second storage means for reading out and temporarily storing the consumable use amount stored in each area designated by a predetermined storage address, and the consumable use amount Based on the storage pattern number read out by the calculation means for calculating the consumables usage amount stored in the second storage means, and the storage pattern number read out by the second storage means. Referring to the address conversion table, the consumable usage amount is changed from each area designated by a predetermined storage address to each area designated by another storage address. And having a storage area changing means for憶.

  According to a preferred example of the image forming apparatus of the present invention, the address changing unit can change the arrangement based on one data of a plurality of address conversion tables prepared in advance. One data can be controlled so as to be selected by a generated random number. In the image forming apparatus according to the present invention, the address changing unit changes the storage address of the consumable usage amount at any one or a plurality of timings when the power is turned on, the consumables are replaced, and the printing is completed. Can do.

The charging system of the image forming apparatus according to the present invention includes a first storage unit that stores a consumable usage amount in each area designated by a predetermined storage address defined by a storage pattern number, and the storage pattern number. And the second storage means for reading out the consumable use amount stored in the area from the first storage means and temporarily storing it, and calculating the consumption amount of the consumable, Based on a plurality of address conversion tables prepared in advance based on the storage pattern number read by the second storage means, the calculation means for updating the consumable consumption amount stored in the storage means, Storage area changing means for changing and storing the consumable usage amount from each area designated by a predetermined storage address to each area designated by another storage address; Reading the consumable consumption of the designated area by the altered the further storage address by the serial storage area changing means and performing predetermined billing.

  According to the image forming apparatus of the present invention, since the address changing unit irregularly changes the storage address of the consumables usage amount stored in the storage unit, an illegal act is performed to read the storage address of the storage unit. In other words, completely different meaningless data is stored, and the data cannot be used for illegal use, and the illegal act itself can be easily suppressed. In the charging system for the image forming apparatus according to the present invention, by changing the storage address irregularly, data for charging can be effectively protected from fraudulent acts, and appropriate charging can be continued.

  Preferred embodiments of the present invention will be described with reference to the drawings. This embodiment is an apparatus such as an electrophotographic printer, a facsimile machine, a copy machine, or a combination machine of these, for example, and printing using a developing unit in which a toner cartridge containing toner as a developer and a photosensitive drum are integrated. It is applied to the device.

  FIG. 1 is a block diagram showing a configuration of a main part of an electrophotographic printer as an image forming apparatus according to the first embodiment of the present invention. In the electrophotographic printer according to the first embodiment, a developing unit having a photosensitive drum and a toner cartridge according to the number of rotations of the photosensitive drum (drum count) and the number of dots actually printed by the LED head (dot count). Each counter is provided for appropriately determining the lifetime of the. Here, the drum count means the number of rotations of the photosensitive drum during the printing operation or the cleaning operation, and the dot count means the number of effective dots (dots actually printed) at the time of printing. Yes.

  As shown in FIG. 1, the electrophotographic printer includes a printer control unit 1 that controls operations such as printing, an LED head 2 that generates recording light in response to control from the printer control unit 1, and the LED head 2 A photosensitive drum for forming an electrostatic latent image corresponding to recording light from the recording drum, a high-voltage power source 51 for charging the photosensitive drum, a charging roller, a transfer roller, and the like, and a heater for heating a fixing roller, which will be described later , A power supply 52 that supplies power to a cooling fan, a thermistor 53 that detects the temperature of the heater, a toner sensor 54 that detects the amount of toner, a display unit 11 that displays the status of the electrophotographic printer, a message to the user, and the like. Etc.

  The printer control unit 1 includes a CPU 3, a memory 4, an EEPROM 5, a gate array (G / A) 6, a printing motor (main motor) 41, a conveyance motor (registration motor) 42, a paper feeding motor (first motor). And the second motor) 43 and 44, drivers 7a, 7b, 7c and 45, a counter 8 for counting the number of rotations of the photosensitive drum (drum counting), and the number of printed dots (dot counting). A dot counter 9.

  FIG. 2 is a side sectional view showing the configuration of the printing mechanism of the electrophotographic printer. This electrophotographic printer uses a developing unit 26 in which a toner cartridge 31 for storing toner, a photosensitive drum 22 and the like are integrated in consideration of convenience at the time of replacement. The developing unit 26 is replaced by the user when it is determined that the lifetime is reached as will be described later.

  As shown in FIG. 2, the developing unit 26 includes a cleaning roller 27, a charging roller 28, a developing roller 30, and the like provided around the photosensitive drum 22. When the developing unit 26 is attached to the electrophotographic printer, the photosensitive drum 22 is disposed at a position close to the LED head 2.

  The electrophotographic printer has a paper tray 12 provided at the lower part of the housing and a paper discharge unit 13 provided on the upper surface of the housing. The paper tray 12 and the paper discharge unit 13 are provided at both ends of the transport path 14. A hopping roller 16 that feeds the paper 15 from the paper tray 12 along the transport path 14, a registration roller 17, a paper sensor 18, and a transfer roller. 19, a heat roller 20, and two discharge rollers 21 are provided. The transfer roller 19 is provided to face the photosensitive drum 22, and pressure rollers 23, 24, and 25 are provided to face the heat roller 20 and the discharge rollers 21. The electrophotographic printer configured as described above executes a printing process in response to an instruction for printing from an external device such as a personal computer, as in the case of a conventional electrophotographic printer.

  When the execution of the printing process is started, the CPU 3 in FIG. 1 first drives the first motor 43 via the G / A 6 and the driver 7c to rotate the hopping roller 16 in FIG. One sheet of paper 15 is fed out. As a result, the sheet is fed out to the conveyance path 14. When the paper sensor 18 detects the paper 15, the CPU 3 drives the main motor 41 via the G / A 6 and the driver 7 a to register the roller 17, the transfer roller 19, the heat roller 20, and the discharge roller 21 in FIG. 2. The photosensitive drum 22, the cleaning roller 27, the charging roller 28, and the developing roller 30 are rotated.

  In addition, the CPU 3 rotates each roller and causes the high-voltage power source 51 to apply a corresponding high voltage to the transfer roller 19, the cleaning roller 27, the charging roller 28, and the developing roller 30. Negative charge is supplied to the charged body layer 22b on the surface of the photosensitive drum 22 by the charging roller 28 to which a negative voltage is applied, and the charged body layer 22b is uniformly charged.

  Further, the CPU 3 sequentially supplies the print data supplied for each line from an external device to the LED head 2 and instructs the generation of the recording light. Thereby, an electrostatic latent image corresponding to the recording light from the LED head 2 is formed on the surface of the photosensitive drum 22 that is uniformly charged. This electrostatic latent image is developed with the toner supplied from the developing roller 30.

  On the other hand, positive charge is supplied to the paper 15 from the transfer roller 19, and when the paper 15 reaches a position facing the toner image, the toner images on the photosensitive drum 22 are sequentially transferred to the paper 15. The toner image transferred to the paper 15 is welded to the paper 15 by the heat roller 20 and the pressure roller 23. When the toner image is welded, the paper 15 is sequentially discharged to the paper discharge unit 13 by the discharge roller 21.

  FIG. 3 is a block diagram of a control system related to data storage used in the image forming apparatus of this embodiment. In FIG. 3, the CPU 3 as the control unit measures the life counter value and the statistical counter value according to the program stored in the ROM 4b, stores the value in the RAM 4a, and stores the data stored in the RAM 4a in a nonvolatile manner. The data is stored in the EEPROM 5, which is a memory. The data stored in the EEPROM 5 is read into the RAM 4a when the apparatus is turned on.

  A part of the programs stored in the ROM 4b will be described. The ROM 4b is configured to store the power-on process B101, the print process B108, and the cover close process B113 as main programs. The power-on process B101 is a process for performing various settings when the power is turned on, and includes an H / W initialization process B102 and a RAM area initialization process B103. In the H / W initialization process B102, various I / O ports are initialized. The RAM area initialization process B103 initializes various RAM areas used in the control program, and executes the EEPROM initialization process B104 as one of them.

  In the EEPROM initialization process B104, a counter value related to consumables control in the EEPROM, which will be described later, is read by the counter copy process B105, and the read counter value is copied to a mirror area on the RAM, which will be described later. The counter value related to the consumables is arranged at an address different from the address stored in the previous power-on state along with the address converted by the processing by the address conversion table B107, and by the EEPROM writing process B106, Also stored in the EEPROM after the conversion.

  In the printing process B108, the printing operation is controlled. In the print process B108, a print start process B109, a print stop process B110, and a print end process B111 are performed. In the printing start process B109, various printing conditions are set according to the printing parameters transmitted from the host, adjustment of the fixing device temperature before printing, and idling of the drum for charging the image drum cartridge are performed. In actual printing process B110, actual printing is performed. At the time of the processing by the printing process B110, the consumable counter value copied to the mirror area on the RAM is updated by the consumable counter updating process B112. In the print end process B111, the last page is discharged, and the consumables counter value in the mirror area on the RAM updated during printing is written in the EEPROM by the EEPROM write process B106.

  The cover closing process B113 performs control when the cover is closed. The cover close process B113 includes various alarm release processes B114 and a consumable item replacement detection process B115. Various alarm release processing B114 performs a recovery operation after a paper jam or the like occurs. The consumable item replacement detection process B115 determines whether or not each consumable item has been replaced. When the replacement of the toner cartridge, the drum cartridge, or the like is detected, the consumable item replacement process B115 performs copying to the mirror area on the RAM by the consumption item counter update process B12. The consumable counter value thus updated is updated, and further, the consumable counter value in the mirror area on the RAM, which has been updated by the replacement detection, is written into the EEPROM by the EEPROM writing process B06.

  FIG. 4 is a memory map of a storage area of the EEPROM 5 which is a nonvolatile memory. Various data to be controlled by the image forming apparatus are stored in the area from address 0 to 255. Counter values relating to consumable control described later include counter value storage pattern number B6 of address 119 described later and storage address table described later. Stored in the address according to The initialized flag B0 is an area indicating whether or not the area of the EEPROM 5 has already been initialized with the map according to FIG. 4. If the flag is set, it indicates that the area has already been initialized. Show. Normally, the initialized flag is set at the first power-on.

  The process cartridge rotation counter B1 is a counter that manages the amount of process cartridge used. The toner consumption counter B2 is a counter that manages the remaining amount of the toner cartridge. The toner cartridge replacement number counter B3 is a counter that manages the number of replacements of the toner cartridge. The process cartridge replacement count B4 is a counter that manages the number of process cartridge replacements. The total number of printed sheets counter B5 is a counter that manages the total number of printed sheets by the image forming apparatus. Note that the above-described counter arrangement is discontinuous and irregular. Further, in the present embodiment, there are five types of counters described above, but the number thereof is arbitrarily determined according to the number of counter values related to the consumer goods. The arrangement shown in FIG. 4 is an arrangement according to when the counter value storage pattern number is “1”, for example.

  FIG. 5 is a memory map of a storage area as a mirror (data copy) area of the EEPROM 5 existing on the RAM 4a. When the power is turned on, the data in the EEPROM 5 is read, and the read data is copied to a predetermined address on the RAM 4a, for example, the address 20000 to 20255 (offset address), and various data controlled by the image forming apparatus is stored in the RAM 4a. Updated. When the data on the RAM 4a is updated and it is detected that a difference from the data on the EEPROM 5 has occurred at a predetermined timing, a data write instruction is issued from the control unit 1, and the data on the RAM 4a is stored in the EEPROM 5. .

  FIG. 6 is a table that defines the storage addresses of various counters arranged on the program of the ROM 4b. The row of the counter value storage pattern number B6 is arranged with a numerical value indicating the index value of the table, and is used when searching for storage addresses of various counters to be described later. In the row of the process cartridge rotation counter B1, a numerical value indicating the storage destination address of the process cartridge rotational force counter B1 is arranged, and the selection of the address varies depending on the numerical value of the counter value storage pattern number B6. The row of the toner consumption counter B2, the row of the toner cartridge replacement count counter B3, the row of the process cartridge replacement count counter B4, and the row of the total print number counter B5 are all stored in the same manner as the description of the row of the process cartridge rotation counter B1. A numerical value indicating an address is arranged and changes depending on the numerical value of the counter value storage pattern number B6.

  The value of the counter value storage pattern number B6 is stored at a fixed address, the minimum value is 0, and the maximum value is N. The maximum value N is related to the data length of this area. If the data length is 1 byte, a value up to 255 can be set. However, in the case of the present embodiment, since the total number of types of counters is five, considering the maximum combination of patterns, 120 patterns at the maximum are sufficient. In the column P0 where the counter value storage pattern number B6 is 0, an address indicating each counter storage position when the counter value storage pattern number is 0 is arranged. That is, exemplifying the case where the counter value storage pattern number is 0, the storage destination of the process cartridge rotation counter B1 is the address 10, the storage destination of the toner consumption counter B2 is the address 12, the storage destination of the toner cartridge replacement number counter B3 is the address 2, The storage destination of the process cartridge replacement number counter B4 is the address 26, and the storage destination of the total print number counter B5 is the address 24. The arrangement in the RAM 4a shown in FIG. 5 represents the storage position when the counter value storage pattern number is 1 (P1). The counter value storage pattern number B6 at the time of factory shipment is set to 0 as an initial value.

  FIG. 7 shows actual table data arranged on the program of the ROM 4b. The process cartridge rotation counter head D1 indicates the head address of the EEPROM address group that stores the process cartridge rotation counter value. For the toner consumption counter head D2, the toner cartridge replacement count counter head D3, the process cartridge replacement count counter head D4, and the total print number counter head D5, the start addresses of the EEPROM address groups are respectively set in the same manner as the process cartridge rotation counter head D1. Show. This table is arranged at an arbitrary position on the ROM 2 program. Further, the address arrangement pattern in this table has an address configuration in which each counter is discontinuously and irregularly arranged due to a change in pattern number.

  FIG. 8 is a layout diagram of the storage area of the EEPROM 5 when the value of the counter value storage pattern number B6 is 2 (column P2 in FIG. 6). As shown in FIG. 4, the storage address of each counter value has changed, the toner cartridge replacement counter (B3) value is stored in the memory area of address 2 instead of the process cartridge rotation counter value, and the memory area of address 10 is stored. The total print number counter (B5) value is stored instead of the toner consumption counter value, and the process cartridge replacement number counter (B4) value is stored in the memory area of the address 12 instead of the toner cartridge replacement number counter value. In the memory area, the toner cartridge rotation counter (B1) value is stored instead of the process cartridge replacement rotation counter value, and in the memory area of the address 26, the toner consumption counter (B2) value is stored instead of the total print number counter value. Has been. Note that the storage area of the counter value storage pattern number at the address 119 has not changed.

  FIG. 9 is a diagram showing processing upon power-on in the present invention. When the power of the image forming apparatus is turned on (S1), all the EEPROM data is copied from the EEPROM to the mirror area on the RAM (S2). The data initialization flag is confirmed (S3). If it has not been initialized (the power is turned on for the first time) (S3 NO), the mirror area on the RAM is initialized and the mirror area data is also initialized. The initialized flag is set, and the counter value storage pattern number is initialized to 0. If it has been initialized, the process proceeds to step 5 (S3 Yes).

  The counter value storage pattern number of the mirror area on the RAM is read out, the storage address of each counter is obtained according to the pattern number and the conversion table on the ROM, each counter value is read out from the address, and the temporary area on the RAM ( Save to the update source register of each counter (S5). Next, when the printing process is performed according to the printing instruction, each counter is updated according to the usage amount (S6). The area to be updated is a temporary area. After this update, the data is stored at the end of printing or at a predetermined time interval. It is determined whether or not it is the above timing (S7).

  The counter value storage pattern number of the mirror area on the RAM is incremented (S8). When the maximum value N of the pattern numbers is exceeded as a result of the increment (S9 YES), 0 is set to the counter value storage pattern number of the mirror area on the RAM (S10). If the pattern number is less than or equal to the maximum value N, the process proceeds to step 11 as it is (S9 NO). In step 11 (S11), the counter value storage pattern number of the updated mirror area on the RAM is read, and each counter value saved in the temporary area on the RAM according to the pattern number and the conversion table on the ROM. Is restored to the corresponding location in the mirror area. Next, the mirror area area on the RAM is stored in the EEPROM (S12), the power-on process is terminated, and the standby state is entered (Sl3).

  In an example of this embodiment, when data is read in step 5 (S5), if the counter value storage pattern number at that time is 0, the total number of printed sheets is stored at address 24. Thereafter, when the total print number data is restored in step 9, the counter value storage pattern number is 1, so that the data is restored to the address 26. The address 26 is the place where the process cartridge replacement counter is stored when the pattern number is 0. In step 10, data is written back to the EEPROM 5 again. At this point, the address arrangement in the EEPROM 5 has changed since the previous power-off.

  FIG. 10 shows a process of reading the total number of printed sheets from the mirror area on the RAM. In this embodiment, the process cartridge rotation counter, the toner consumption counter, the toner cartridge replacement number counter, and the process cartridge replacement number counter are also read by the same method as the total print number reading process. When a read request for the total number of printed sheets is generated (S21), first, the counter value storage pattern number of the mirror area on the RAM is read (S22). Thereafter, the counter value storage pattern number read in step 22 is added to the total print sheet counter start address of the conversion table on the ROM, and the address at which the total print sheet count value is stored is read from the table on the ROM. (S23). The address read in step 23 is added to the offset address 20000 of the mirror area on the RAM, the total print number counter is read from the mirror area on the RAM, and stored in an arbitrary temporary area on the RAM (S24). Is finished (S25).

  FIG. 11 shows a process of writing the total number of printed sheets in the mirror area on the RAM. In this embodiment, the process cartridge rotation counter, the toner consumption counter, the toner cartridge replacement count counter, and the process cartridge replacement count counter are written in the same manner. When a write request for the total number of printed sheets is generated (S31), first, the counter value storage pattern number of the mirror area on the RAM is read (S32). It is assumed that data to be written is stored in advance in an arbitrary temporary area on the RAM. Thereafter, the counter value storage pattern number read in step 32 is added to the total print sheet counter start address of the conversion table on the ROM, and the address at which the total print sheet count value is stored is read from the table on the ROM. (S33).

  The address read in step 23 is added to the offset address 20000 of the mirror area on the RAM, and the value is written from the arbitrary temporary area on the RAM to the total print number counter value area on the mirror area on the RAM (S34). The writing process is terminated (S35).

  FIG. 12 shows a process of writing the mirror area data on the RAM into the EEPROM. When a write request to the EEPROM is generated (S41), first, the address pointer of the mirror area on the RAM and the address pointer of the EEPROM are set, and the initial value 0 is set to the index counter I on the RAM. (S42). Next, the index counter I is added to the head address of the mirror area on the RAM to read the data in the mirror area on the RAM. The read value is set as X (S43). Next, the index counter I is added to the start address of the EEPROM to read the data on the EEPROM. Here, the read value is Y (S44). The data X read in step 43 and the data Y read in step 44 are compared (S45). If they are equal, the process proceeds to step 47 (S47). In this case, writing to the EEPROM is not performed (S45 YES). If they are not equal (NO in S45), it is determined that the data has been updated, and the data X read in step 43 is written to the address obtained by adding the index counter I to the start address of the EEPROM (S46). The index counter I is incremented (S47). It is determined whether or not the index counter I has exceeded 255 (S48). If it has not exceeded (S48 NO), the same processing is repeated from step 43. If it has exceeded (YES in S48), the process proceeds to step 49 and the writing process of the EEPROM is terminated (S49).

  As described above, by using a memory table storing an irregular storage pattern, the storage location of the life counter value and statistical counter value held on the nonvolatile memory (EEPROM) each time the power is turned on is irregular. This makes it difficult to analyze which address corresponds to which counter value even if the EEPROM is removed from the board and the data in the EEPROM is referenced by an EEPROM writer. Data can be prevented from being falsified. Therefore, in a system that charges based on the life count value or statistical count value, it is possible to prevent disadvantages caused by the fraud.

  FIG. 13 is a control block diagram relating to data storage of the present invention in the image forming apparatus of the second embodiment. In the figure, the control unit 103 measures the life counter value and the statistical counter value according to the control program stored in the ROM 104b, stores the value in the RAM 104a, and stores the data stored in the RAM 104a in a nonvolatile memory. The data is stored in a certain EEPROM 105. The data stored in the EEPROM 105 is read into the RAM 104a when the apparatus is turned on. The power-on process B101 performs various settings at power-on. In the EEPROM initialization process B104, a counter value related to consumables control on the EEPROM, which will be described later, is read out by the counter copy process B105 and copied to a mirror area on the RAM, which will be described later. B107 and a random number generation function process (B116) for generating a random number using a random number generation function are converted into a random address pattern, arranged at an address different from the address stored in the previous power-on state, and written to the EEPROM. By processing B106, it is also stored in the arrangement after conversion on the EEPROM.

  FIG. 14 is a diagram showing a power-on process in the second embodiment. When the power of the image forming apparatus is turned on (S101), all the data of the EEPROM is copied from the EEPROM to the mirror area on the RAM (S102). In order to check whether or not data is already stored in the mirror area on the RAM, the data initialization flag is checked (S103). If the data has not been initialized (the power is turned on for the first time) (S103). NO), the mirror area on the RAM is initialized, the data initialization flag of the mirror area is set, and the counter value storage pattern number is initialized to 0 (S104). If it has been initialized, the routine goes to Step 105 (S103 YES). The counter value storage pattern number of the mirror area on the RAM is read out, the storage address of each counter is obtained according to the pattern number and the conversion table on the ROM, each counter value is read out from the address, and the temporary area on the RAM ( The data is saved in the update source register of each counter (S105).

  Next, when printing processing is performed according to the printing instruction, each counter is updated according to the usage amount (S106). The area to be updated is a temporary area. After this update, the data is stored at the end of printing or at a predetermined time interval. It is determined whether or not the timing is reached (S107). Subsequently, a random number is generated by a random number generation function that randomly generates integers from 0 to N, and is stored in the counter value storage pattern number of the mirror area on the RAM. At this time, if the generation result of the random number is the same value as the previous time, the random number is generated again by the random number generation function (S108). The counter value storage pattern number of the mirror area on the updated RAM is read, and each counter value saved in the temporary area on the RAM according to the pattern number and the conversion table on the ROM is changed to the corresponding part of the mirror area. (S109). Next, the mirror area on the RAM is stored in the EEPROM (S110). Thereafter, the power-on process is terminated and the process shifts to a standby state (S111).

  As described above, in the second embodiment, the counter value storage pattern value is not changed in ascending order as in the first embodiment, but is changed randomly using a random number generation function. In addition to irregularly changing the storage location of the life counter value and statistical counter value held in the nonvolatile memory (EEPROM 105), the counter value storage pattern value is randomly changed, so that the EEPROM 105 is removed from the substrate. Even if the data in the EEPROM is referred to by an EEPROM writer or the like, it is possible to make it more difficult to analyze which address corresponds to which counter value than in the first embodiment. It becomes possible to prevent tampering. Therefore, it is possible to solve the problem that a fraudulent act incurs a disadvantage in a system that charges based on the life count value or statistical count value.

  FIG. 15 is a control block diagram relating to data storage of the present invention in the image forming apparatus of the third embodiment. In the figure, the control unit 111 measures the life counter value and the statistical counter value according to the control program stored in the ROM 114b, stores the value in the RAM 114a, and stores the data stored in the RAM 114a in a nonvolatile memory. Saved in a certain EEPROM 115. The data stored in the EEPROM 115 is read into the RAM 114a when the apparatus is turned on.

  FIG. 16 is a diagram illustrating a part of the processing at the time of detecting the cover close in the third embodiment. When closing of the cover of the image forming apparatus is detected (S201), the counter value storage pattern number of the mirror area on the RAM is read, and the storage address of each counter is obtained according to the pattern number and the conversion table on the ROM, Each counter value is read from the address and saved in a temporary area (update counter register of each counter) on the RAM (S202). Next, the counter value storage pattern number of the mirror area on the RAM is updated (incremented) (S203). As a result of the update, if the pattern number exceeds the maximum value N (S204 YES), 0 is set to the counter value storage pattern number of the mirror area on the RAM (S205). If the pattern number is less than or equal to the maximum value N, the process proceeds to step 206 as it is (S204 NO). Read the updated counter value storage pattern number of the mirror area on the RAM and, according to the pattern number and the conversion table on the ROM, save each counter value saved in the temporary area on the RAM to the corresponding mirror area. Return to the location (S206). The mirror area area on the RAM is stored in the EEPROM (S207). Thereafter, the process proceeds to the conventional cover closing process (S208).

  As described above, in the third embodiment, the storage address of each counter on the EEPROM 115 is moved at the cover closing timing. Since there is a command function that can read EEPROM data online for maintenance, even if the EEPROM command is read after replacement of consumables (after the cover is closed) using this maintenance command function, It is possible to make it difficult to analyze whether the value corresponds to the counter value, and to make it difficult for an unauthorized user to tamper with the data. Therefore, it is possible to solve the problem that in some cases, such as a system that charges based on the life count value or the statistical count value, there is a case where it is disadvantageous due to the fraud.

  FIG. 17 is a control block diagram relating to data storage of the present invention in the fourth embodiment. In the figure, the control unit 123 measures the life counter value and the statistical counter value according to the control program stored in the ROM 124b, stores the value in the RAM 124a, and stores the data stored in the RAM 124a in the nonvolatile memory. Is stored in the EEPROM 125. The data stored in the EEPROM 125 is read into the RAM 124a when the apparatus is turned on.

FIG. 18 is a flowchart showing a part of processing at the end of printing in the fourth embodiment. For example, when the printing of the image forming apparatus is stopped (S301), such as when a print job is finished, when a single print is discharged, or when a predetermined time has passed since the last print was finished (S301), The counter value storage pattern number is read out, the storage address of each counter is obtained according to the pattern number and the conversion table on the ROM, each counter value is read from the address, and the temporary area on the RAM (the update source register of each counter) (S302). The counter value storage pattern number of the mirror area on the RAM is updated (incremented) (S303). As a result of the update, if the maximum value N of pattern numbers is exceeded (S304 YES), 0 is set to the counter value storage pattern number of the mirror area on the RAM (S305). If the pattern number is less than or equal to the maximum value N, the process proceeds to step 306 as it is (S304 NO). The counter value storage pattern number of the mirror area on the updated RAM is read, and each counter value saved in the temporary area on the RAM according to the pattern number and the conversion table on the ROM is changed to the corresponding part of the mirror area. (S306). The mirror area area on the RAM is stored in the EEPROM (S307). Thereafter, the process proceeds to a conventional print end process (S308).

As described above, in the fourth embodiment, the storage address of each counter on the EEPROM is moved at the end of printing. Since there is a command function that can read EEPROM data in an online state for maintenance, even if the EEPROM command is read after updating the number of printed sheets (after printing is completed) using this maintenance command function, It can make it difficult to analyze whether the data falls under the counter value, making it difficult for unauthorized users to tamper with the data. Therefore, it is possible to solve the problem that in some cases, such as a system that charges based on the life count value or the statistical count value, there is a case where it is disadvantageous due to the fraud.

The image forming apparatus of each of the above-described embodiments includes a printer, a facsimile, an MFP (Multifunction Peripheral), a copier having a function of storing consumable management data represented by a life count value and a statistical count value in a nonvolatile memory. It is applicable to such devices.

  In each of the above-described embodiments, the nonvolatile memory for storing the consumable counter value is provided in the image forming apparatus main body. However, the non-volatile memory may be provided in the process cartridge main body. In the above-described embodiment, the consumables counter value of the image forming apparatus has been described. However, the present invention is not limited to this, and the present invention is also applicable to a charging system including a non-volatile memory for storing the counter value. be able to. For example, the present invention is also applicable to a system that adds a count value depending on usage time and charges, a system that charges a counter value based on the number of used packets, or a system that charges based on the amount of power used. Can do.

  In the above-described embodiment, there are five types of counters, but the number is arbitrarily determined by the number of counter values related to consumables. For example, a color output counter, a black and white output counter, or a print pixel number counter is also included.

1 is a block diagram illustrating an example of an image forming apparatus according to a first embodiment of the present invention. 1 is a schematic side view illustrating a configuration of a printing mechanism as an example of an image forming apparatus according to a first embodiment of the present invention. 1 is a block diagram of a configuration related to data storage of an example of an image forming apparatus according to a first embodiment of the present invention. 1 is a configuration diagram of a storage area of an EEPROM in an example of an image forming apparatus according to a first embodiment of the present invention. 1 is a configuration diagram of a mirror region of an EEPROM existing on a RAM in an example of an image forming apparatus according to a first embodiment of the present invention. 6 is a table that defines storage addresses of various counters arranged on a ROM program in the image forming apparatus according to the first embodiment of the present invention. 3 shows actual table data arranged on a ROM program in an example of the image forming apparatus according to the first embodiment of the present invention. FIG. 6 is an arrangement diagram of the storage area of the EEPROM when the value of the counter value storage pattern number B6 in the example of the image forming apparatus according to the first embodiment of the present invention is “2”. 5 is a flowchart showing each process at power-on in the example of the image forming apparatus according to the first embodiment of the present invention. 6 is a flowchart showing a process of reading a total number of printed sheets from a mirror area on a RAM in an example of the image forming apparatus according to the first embodiment of the present invention. 6 is a flowchart showing a process of writing the total number of printed sheets from a mirror area on a RAM in an example of the image forming apparatus according to the first embodiment of the present invention. 3 is a flowchart showing a process of writing data in a mirror area on a RAM to an EEPROM in an example of the image forming apparatus according to the first embodiment of the present invention. It is a block diagram of the structure regarding the data storage of an example of the image forming apparatus concerning the 2nd Embodiment of this invention. 6 is a flowchart showing each process at power-on in an example of an image forming apparatus according to a second embodiment of the present invention. It is a block diagram of the structure regarding the data storage of an example of the image forming apparatus concerning the 3rd Embodiment of this invention. 10 is a flowchart showing each process when a cover is closed in an example of an image forming apparatus according to a third embodiment of the present invention. It is a block diagram of the structure regarding the data storage of an example of the image forming apparatus concerning the 4th Embodiment of this invention. 10 is a flowchart illustrating processing at the end of printing in an example of an image forming apparatus according to a fourth exemplary embodiment of the present invention.

Explanation of symbols

1 Print Control Unit 2 LED Head 3 Control Unit (CPU)
4 Memory 4a RAM
4b ROM
5 EEPROM
8 Counter 9 Dot Counter 11 Display Unit 22 Photosensitive Drum 26 Developing Unit 54 Toner Sensor 103 Control Unit (CPU)
104a RAM
104b ROM
105 EEPROM
113 Control unit (CPU)
114a RAM
114b ROM
115 EEPROM
123 Control unit (CPU)
124a RAM
124b ROM
125 EEPROM

Claims (8)

An image forming apparatus that calculates and stores a consumable usage amount,
First storage means for storing the amount of consumables used in each area designated by a predetermined storage address defined by a storage pattern number ;
Second storage means for reading and temporarily storing the storage pattern number and the consumable usage amount stored in each area designated by a predetermined storage address ;
Calculating means for calculating a consumption amount of consumables, and updating the consumption consumption amount stored in the second storage means;
Based on the storage pattern number read by the second storage means, referring to a plurality of address conversion tables prepared in advance, the amount of consumables used is determined from each area designated by a predetermined storage address. An image forming apparatus comprising storage area changing means for changing and storing each area designated by a different storage address . The storage pattern number is a counter value storage pattern number that defines a storage destination address of a counter value according to the usage amount of the consumables usage amount,
An arrangement pattern of storage addresses in the address conversion table is an address configuration that becomes discontinuous and irregular due to a change in the counter value storage pattern number,
The storage area changing means selects one pattern from a plurality of arrangement patterns for changing the count value storage pattern number and sets the storage address.
The image forming apparatus according to claim 1. One data of the plurality of address conversion tables is selected by a generated random number.
The image forming apparatus according to claim 1. The storage area changing means changes the storage address of the consumable usage amount at any one or a plurality of timings when the power is turned on, the consumables are replaced, and the printing is completed.
The image forming apparatus according to claim 1. The first storage means is a nonvolatile memory
The image forming apparatus according to claim 1. First storage means for storing the amount of consumables used in each area designated by a predetermined storage address defined by a storage pattern number;
Second storage means for reading out the storage pattern number and the consumable usage amount stored in the area from the first storage means and temporarily storing them;
Calculating means for calculating a consumption amount of consumables, and updating the consumption consumption amount stored in the second storage means;
Based on the storage pattern number read by the second storage means, referring to a plurality of address conversion tables prepared in advance, the amount of consumables used is determined from each area designated by a predetermined storage address. Storage area changing means for changing and storing each area designated by another storage address;
Reading the amount of consumables used in the area specified by the other storage address changed by the storage area changing means and charging the required amount
A charging system for an image forming apparatus. The storage area changing means changes the storage address of the consumable usage amount at any one or a plurality of timings when the power is turned on, the consumables are replaced, and the printing is completed.
The charging system for an image forming apparatus according to claim 6. In an image forming apparatus that stores usage information regarding consumables of the apparatus,
Management means for managing the usage information;
First storage means for storing the usage information in an area designated by a predetermined storage address defined by a storage pattern number;
Second storage means for reading out and temporarily storing the storage pattern number and the use information stored in each area designated by a predetermined storage address;
Calculating means for calculating a consumption amount of consumables and updating the usage information stored in the second storage means;
Based on the storage pattern number read out by the second storage means, a plurality of address conversion tables prepared in advance are referred to, and the usage information is separated from each area designated by a predetermined storage address. Storage area changing means for changing and storing each area specified by the storage address
  An image forming apparatus.