JP4632396B2 - MEMORY AND MEMORY STORAGE METHOD - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention provides a memory as well as Memory storage To the law It is related.
[0002]
[Prior art]
Conventionally, in copiers and laser beam printers using electrophotographic technology, various parts used for image formation are unitized, and the unit is detachably attached to the main body of the apparatus, and replaced whenever the unit reaches the end of its life. Thus, an apparatus for using and managing the image forming apparatus is provided.
[0003]
As shown in FIG. 10, the unit used for image formation includes a photosensitive drum as an image carrier, a charging roller as a charging member for uniformly charging the surface of the photosensitive drum, and a developer on the photosensitive drum. A developing device comprising a developing roller as a developing member for supplying toner and a developer container is a unitized cartridge, and is detachably mounted on the apparatus main body.
[0004]
In recent years, a cartridge with a built-in memory in which a nonvolatile memory (for example, EEPROM, hereinafter referred to as a memory) is mounted on the cartridge is being used. In this cartridge with built-in memory, information on the life of the cartridge such as the accumulated time of the rotation of the drum and the remaining amount of toner is stored, and the printer control unit that acquired the information by communication determines the life of the toner cartridge, Judgment is made such as canceling the print signal from the controller.
[0005]
Both writing and reading of data can be performed on the memory of the cartridge. Data can be written to and read from the memory based on the instruction from the printer control unit described above. In addition, after data has been written, for data that cannot be rewritten thereafter, it is possible to perform a work (hereinafter referred to as locking) for making the data write-inhibited. Once the data is locked, after that, writing to the corresponding area cannot be performed, and only reading is possible. The data size that can be locked in a lump differs depending on the memory, such as every byte, every 2 bytes, every 4 bytes, every 40 bytes, etc.
[0006]
In addition, the lockable data size does not always match for all the data areas in the memory, and a part of the area in the memory is 1 byte, and a different part is every 4 bytes. There are also memories with different lockable data sizes.
[0007]
Various structures of data stored in the memory are conceivable, and one of them is a double buffer configuration for improving data reliability. This is a method in which the entire data is divided into a main buffer and a backup buffer, data having the same meaning is stored in both, and the corresponding data is used as a reliable one by matching both.
[0008]
Further, as a technique for improving reliability, there is a method of providing a checksum in each buffer after a double buffer configuration. According to this method, the checksum is updated and stored every time data is updated for each buffer. Also, check the checksum when using memory data such as when the main unit is started, and if an abnormality is found in the checksum, use the data in the buffer that did not have an abnormality in the checksum, By restoring all the data, it becomes possible to use the memory thereafter.
[0009]
[Problems to be solved by the invention]
However, in the above conventional example, the data on the memory can be locked when it is determined that the data will not be rewritten thereafter, but the data is locked even with information that can only be expressed in two states represented by bits. For this purpose, the area is locked in a predetermined unit such as a 1-byte (8-bit) unit on the internal structure of the memory. That is, since it is necessary to extend the data size to the smallest unit that can be locked, the use efficiency of the data area of the memory is reduced, and the data area is wasted.
[0010]
In addition, when the data stored in the memory is configured as a double buffer and each buffer is provided with a checksum, the data storage order is as follows.
(1) Main buffer data update
(2) Main buffer checksum update
(3) Main buffer data lock
(4) Backup buffer data update
(5) Backup buffer checksum update
If an error occurs at the stage (2), the data in the main buffer is restored using the data in the backup buffer according to the conventional method. Then, when the data rewrite instruction is issued again, the data in the corresponding area is rewritten again. For example, if the data rewrite instruction issuance interval is very long, the data rewrite is not executed until the data change timing comes again, even though the data change timing has once arrived.
[0011]
The present invention has been made to solve the above-described problems, and a memory that can efficiently use the data area of the memory. as well as Memory storage The law The purpose is to provide.
[0012]
Another object of the present invention is to restore the state of the memory close to the latest state when a memory data abnormality occurs.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a memory that is detachably attached to an image forming apparatus and is mounted on a cartridge that stores a developer, and information relating to the amount of the developer stored in the cartridge. In a memory having a first storage area for storing information and a second storage area for storing backup information for backing up information stored in the first storage area. Each of the first information indicating the remaining amount of the developer and the second information indicating that the amount of the developer has decreased is stored as byte-size information having a predetermined number of bits, and the second storage area As the backup information of the first information, Of the first storage area The first information Same as Store as the byte size information, and as the backup information of the second information, In the first storage area The second information Indicates that is remembered 1-bit information The It is memorized.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings (FIGS. 1 and 2).
[0018]
FIG. 1 is a schematic diagram showing an example of a laser printer using an electrophotographic technique to which the present invention can be applied. In FIG. 1, reference numeral 101 denotes a photosensitive drum as an electrostatic latent image carrier. Above this photosensitive drum 101, a charging roller 102 for uniformly charging the surface of the photosensitive drum 101 is in contact with the surface. . A light beam 103 is irradiated on the charged surface of the photosensitive drum 101 downstream of the contact position of the charging roller 102 by the light emitting means. The light emitting means includes a semiconductor laser 104 that emits a light beam 103, a scanner 105 that scans the light beam 103 on the surface, and an optical lens 106 that adjusts the light beam 103 to form a spot on the surface. It is composed of Then, an electrostatic latent image is formed on the surface by irradiating the light beam 103 based on the image data. The electrostatic latent image is developed as a toner image by a developing device 107 disposed so as to be in contact with the photosensitive drum 101 further downstream in the rotation direction of the photosensitive drum 101 than the irradiation position of the light beam 103.
[0019]
The toner image is transferred onto a sheet P as a transfer material by a transfer roller 108 disposed below the photosensitive drum 101 so as to face the photosensitive drum 101. The paper P is stored in the paper cassette 109 in front of the photosensitive drum 101 (on the right side in FIG. 1), but can be fed manually. A paper feed roller 110 is disposed at the end of the paper cassette 109, and the paper P in the paper cassette 109 is sent to the transport path. In the conveyance path between the paper feed roller 110 and the transfer roller 108 described above, a registration roller 111 for correcting the skew of the paper P and synchronizing the image formation on the photosensitive drum 101 and the paper conveyance is disposed. Then, the paper P is sent to the transfer position described above at a predetermined timing. A registration sheet presence / absence detection sensor 112 is disposed between the registration roller 111 and the sheet feeding roller 110, and is configured to detect the presence / absence of the sheet P.
[0020]
As described above, the sheet P on which the unfixed toner image is transferred is further conveyed to the fixing device behind the photosensitive drum 101 (left side in FIG. 1). This fixing device includes a fixing roller 113 having a fixing heater (not shown) therein, and a pressure roller 114 disposed so as to be in pressure contact with the fixing roller 113, and the sheet P transferred and conveyed. Is heated while being pressed at the pressure contact portion between the fixing roller 113 and the pressure roller 114, whereby the unfixed toner image on the paper P is fixed. A discharge paper presence / absence detection sensor 115 for confirming that the paper P is discharged from the press contact portion is disposed behind the press contact portion. Further, a paper discharge roller 116 is disposed behind the paper discharge presence / absence detection sensor 115 to discharge the fixed paper P to the paper discharge tray 117.
[0021]
Next, the control unit of the electrophotographic printer having such a mechanism unit will be described with reference to FIG. In FIG. 2, reference numeral 201 denotes a host computer arranged outside the electrophotographic printer, which sends image code data created by the operation of the user or the like to the controller 203 through the communication line 202 as parallel or serial data. The controller 203 expands the image code data sent from the host computer 201 and converts it into image information to be sent to the printer. The controller 203 also instructs the printer control unit 204 to send a command or receives internal data from the printer control unit. As a status, or a print start request or pre-feed request is made to the printer control unit. The controller 203 also controls a synchronization signal for synchronizing the image output timing with the paper conveyance in the printer, and may exist in the printer or in the host computer. The printer control unit 204 is connected to an operation panel 205 for the user to operate various printer mode settings (for example, image area margin settings).
[0022]
The controller 203 connected to the host computer 201 transmits / receives data to / from the printer control unit 204 as described above. The printer control unit 204 controls the drive / stop timing of each mechanism unit in FIG. 1 and reads input information from each sensor, so that the conveyance system drive unit 206, the high-voltage system drive unit 207, the optical system drive unit 208, and the fixing heater control are controlled. The unit 209 and the sensor input unit 210 are connected.
[0023]
First, the transport system drive unit 206 drives / stops the various motors 211 and the various rollers 212, and the high-voltage system drive unit 207 drives / stops the charging 213, the development 214, and the transfer 215 of the printer control unit 204, respectively. Based on instructions. The optical system driving unit 208 performs driving / stopping of the laser 104 and the scanner 105, and the fixing heater control unit 209 performs driving / stopping of the fixing heater 216 based on instructions from the printer control unit 204, respectively. ing. The sensor input unit 210 is a sensor input unit that reads information from the registration sheet presence / absence detection sensor 112 and the discharged sheet presence / absence detection sensor 115 and provides the information to the printer control unit 204.
[0024]
Next, the operation of the apparatus of the present invention will be described. First, the printer waits for a print signal from the controller 203. If the print signal is not received, the controller 203 checks whether or not there is a pre-feed request from the controller 203. If the pre-feed request is received, the motor 211 is driven and the paper feed operation is started. Thereafter, it is checked whether or not the paper P arrives at the registration paper presence / absence detection sensor 112. When the sensor 112 detects the leading edge of the paper, the paper feed operation is stopped after waiting for a predetermined time. At that time, the motor 211 is stopped and the print signal is waited. When the print signal is received, when the motor 211 is driven again, the scanner 105 starts up each high voltage. When the scanner motor (not shown) reaches the specified rotation, the paper P has already been pre-fed, so the registration paper presence / absence detection sensor 112 checks for the presence of paper. At this time, if there is no sheet P in the resist sheet presence / absence detection sensor 112, an abnormal process (such as a jam process) is performed. When the paper P is present in the sensor 112, a vertical synchronization signal is output to the controller 203. Thereafter, when a vertical synchronizing signal is received, image writing to the photosensitive drum 101 is permitted and the registration roller 111 is driven. Then, after the paper discharge presence / absence detection sensor 115 detects the trailing edge of the paper and waits for a predetermined time, the high voltage start-up and the scanner motor are stopped, and then the roller driving system motor is stopped to stop the printing process.
[0025]
In this embodiment, as shown in FIG. 1, a photosensitive drum 101 as an image carrier, a charging roller 102 as a charging member for uniformly charging the surface of the photosensitive drum 101, and the photosensitive drum 101 with a developer. The developing device 107 which is a developing means for supplying a certain toner is made into one unit, and the detachable cartridge 200 is configured.
[0026]
The unit used for image formation is not limited to the above-described form, and for example, a unit in which the developing unit 107 and the photosensitive drum 101 are unitized, or a unit in which only the developing unit is unitized may be used.
[0027]
The cartridge 200 is provided with an EEPROM 219 as a non-volatile storage means. The EEPROM 219 stores information on the life of the cartridge 200 such as the accumulated time of drum rotation and the remaining amount of toner. The printer control unit 204 of the apparatus main body that has acquired the information determines the life of the cartridge 200 and makes a determination such as canceling the print signal from the controller 203.
[0028]
The unitized cartridge 200 is configured to be detachable from the main body of the image forming apparatus. When the cartridge 200 is attached to the main body of the image forming apparatus, the EEPROM 219 and the printer control unit 204 shown in FIG. It becomes possible. Although not shown here, any data communication method may be used as long as it can execute data transmission / reception to / from a non-volatile memory such as an EEPROM such as communication by a connector connection or communication by a wireless method.
[0029]
Next, with reference to the drawings (FIGS. 3, 4, and 5), the use history and process conditions for the process cartridge that is detachably mounted on the image forming apparatus main body using the electrophotographic process in the present embodiment is used. A method for efficiently using a data area of a nonvolatile memory for recording data relating to image formation such as the above will be described. In this embodiment, a main buffer and a backup buffer are provided, and data stored in the main buffer is stored by expanding bit information (data) to a lockable data size, but data stored in the backup buffer is data lock. Without being performed, it is shrunk and stored in bit units together with other information that is normally stored in bit units in the backup buffer.
[0030]
FIG. 3 is a diagram simply showing the allocation of data areas of the EEPROM 219 shown in FIGS. First, consider a case where each of the main buffer and the backup buffer has 1-byte checksum information. FIG. 3A is a diagram showing data allocation in the conventional example. As shown in FIG. 3A, when the minimum unit capable of locking data is 1 byte, eight types of bit information are expanded and assigned to 1 byte each. In this example, an 8-byte data area and a 1-byte checksum data area are secured for the main buffer. Similarly for the backup buffer, an 8-byte data area and a 1-byte checksum data area are secured. That is, 18 bytes of data area of the memory are used to store 8 bits of data.
[0031]
On the other hand, (b) shown in FIG. 3 is a diagram showing data allocation in the present embodiment. As shown in FIG. 3B, for the main buffer, as in FIG. 3A, an 8-byte data area and a 1-byte checksum data area are secured. However, regarding the backup buffer, bit information (data) is handled in units of bits as it is, and is shrunk together with other bit information and stored in a 1-byte area. As a result, the backup buffer can store data with a data size of 2 bytes even if the checksum is included.
[0032]
Comparing each data size used in the above case, (a) shown in FIG. 3 is 18 bytes, (b) shown in FIG. 3 is 1 byte, and the use efficiency of the memory area of about 39% is Improvement is achieved.
[0033]
FIG. 3C shows data stored in the EEPROM 219. In the EEPROM 219, for example, information indicating a state such as a state where the remaining amount of toner, which is a use history of the process cartridge, is low, a state where the remaining amount of toner is not present, or information indicating the state, A plurality of information such as information (remaining amount of toner in the developing device, such as g and%) and drum usage information (drum rotation time, number of prints) are stored. Backup of information indicating the status (set / reset status) such as low amount or no toner remaining is backed up in bit units, and other information such as toner usage and drum usage is the same information as the main buffer. Are backed up in the same byte unit. That is, the backup buffer of the storage area of the EEPROM 219 of the process cartridge has a storage area to be backed up in bit units and a storage area to be backed up in byte units, as shown in FIG.
[0034]
Next, a description will be given of a method of repairing the state of the memory close to the latest state when the above-described memory data abnormality occurs.
[0035]
In the present embodiment, when the bit information is expanded to the minimum data lockable size, for example, 1 byte size, the value that the expanded data can take is the state in which the bit information is set (data is written). 2), an arbitrary value representing the state) and an arbitrary value representing the state where the bit information (data) is reset (the state before the data is written), and the other values are the states where an abnormality has occurred. Can think. Furthermore, if the data in the area to be locked after rewriting, the data in the corresponding area can be changed from the default value to the predetermined value (if the default value is set, the predetermined value is in the reset state, and the default value is in the reset state Then, the predetermined value is only the set state), and the value after the change is significant. That is, when an abnormality occurs, the probability that the data in the corresponding area becomes a predetermined value is 1/256 when it is expanded to 1 byte and 1/65536 even when it is expanded to 2 bytes. Even if the checksum indicates an abnormality, if the expanded data indicates a predetermined value, it is a level where there is no problem even if the buffer value indicating the abnormality is used as it is for the data. Judgment can be made.
[0036]
That is, when an abnormality occurs, if the mechanism in which the data in the region where the abnormality occurs becomes 00h or FFh is clarified, a predetermined value that represents a value after the change of the bit information (data) is set to 00h or The reliability can be further improved by avoiding FFh (when expanded to 1 byte).
[0037]
From the above, for example, when extending to 1 byte, even if a checksum abnormality is determined for the data in the main buffer, if the data in the main buffer is a predetermined value, the value in the backup buffer is set for that area. The value of the main buffer is used as it is without repairing.
[0038]
FIG. 4 is a diagram showing a state of data restoration in the present embodiment. Here, in order to simplify the explanation, each data is assumed to change from the reset state to the set state.
[0039]
FIG. 4A shows the state of each buffer and checksum when an abnormality has occurred. In this example, the data areas 1 to 8 of the main buffer are values (hereinafter, “reset state”) in which the data areas 1 and 2 indicate a reset state, and values (hereinafter, “data areas 3 and 4” indicate a set state). The data areas 5 and 6 are abnormal values that are neither “set state” nor “reset state” (hereinafter “abnormal value”), and the data areas 7 and 8 are “set state”. Further, it is in a locked state (hereinafter, “locked state”).
[0040]
In the main buffer, when the checksum (total) of the data areas 1 to 8 is calculated, it is assumed that the calculated value does not match the value stored in the checksum storage area. In the backup buffer, information corresponding to the data areas 1 to 8 is in the order of reset and set, and the checksum of the backup buffer is the same as the calculated value and the stored value.
[0041]
FIG. 5 is a flowchart showing data restoration processing in the present embodiment. The control of this flowchart is executed by a program stored in a ROM or the like (not shown) in the printer control unit 204 of FIG.
[0042]
First, in step S501, an index n indicating the data area of the main buffer and the bit area of the backup buffer is initialized to “1”. Next, in step S502, it is determined whether the data area (n) of the main buffer is locked. If not, the process proceeds to step S503, and it is determined whether the data area (n) of the main buffer is set. As a result, if it is not in the set state, the process advances to step S504 to determine whether the bit area (n) of the backup buffer is in the set state. As a result, if the bit area (n) is not in the set state, the process proceeds to step S505, and the data area (n) of the main buffer is rewritten to the reset state. Next, in step S506, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten.
[0043]
As described above, in the case of steps S502 to S505, the data area (n) of the main buffer is in the reset state or an abnormal value, and the bit information in the bit area (n) of the backup buffer corresponds to the reset state. In the example of (a) shown, the reset state of the data area 1 and the abnormal value of the data area 5 are rewritten to the reset state as shown in (b) of FIG.
[0044]
In step S504, if the bit area (n) of the backup buffer is set, the process proceeds to step S507, and the data area (n) of the main buffer is rewritten to the set state. In step S508, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten. In step S509, the data area (n) of the main buffer is set to the locked state.
[0045]
As described above, in the case of steps S504 → S507, the data area (n) of the main buffer is in the reset state or an abnormal value, and the bit information in the bit area (n) of the backup buffer corresponds to the set state. In the example of (a) shown, the reset state of the data area 2 and the abnormal value of the data area 6 are rewritten to the set state, and further rewritten to the locked state as shown in (b) of FIG.
[0046]
In step S503, if the data area (n) of the main buffer is in the set state, the process proceeds to step S510, and the data area (n) of the main buffer is set in the locked state. In step S511, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten. In step S512, the bit area (n) of the backup buffer is rewritten to the set state. Next, in step S513, the checksum of the backup buffer is calculated, and the data in the checksum storage area is rewritten.
[0047]
As described above, in the case of steps S503 to S510, the data area (n) of the main buffer corresponds to the set state. In the example of FIG. 4A, the set state of the data area 3 and the data area 4 is illustrated. As shown in FIG. 4 (b), each is rewritten to the locked state. Then, the bit information in the bit area 3 of the backup buffer is rewritten to the set state.
[0048]
In step S502, if the data area (n) of the main buffer is in the locked state, the process proceeds to step S516, and it is determined whether the data area (n) of the main buffer is in the set state. As a result, if the data area (n) of the main buffer is not set, it is determined that the memory cannot be restored. That is, in the present embodiment, the data in the main buffer is locked only in the processes in steps S509 and S510 described above, and in these cases, the data in the main buffer is in the set state. If the data area (n) of the main buffer is in the set state, the process proceeds to step S511, and the above-described processing is performed.
[0049]
Thus, in the case of steps S502 → S516, the data area (n) of the main buffer corresponds to the locked state, and in the example of (a) shown in FIG. As shown in FIG. 4B, the bit information in the bit area 7 of the backup buffer is rewritten to the set state.
[0050]
Next, when the above process ends, index n is updated in step S514, and it is determined in step S515 whether all repairs have been completed, and if completed, the process ends. Returning to step S502, the above-described processing is repeated.
[0051]
If the checksum of the main buffer does not match the calculated value and the checksum of the backup buffer matches the calculated value, the data restoration rules are summarized as follows.
(1) Basically, restoration is performed using the value of the backup buffer. When setting the value of the main buffer, the data is also locked. However, the following cases are exceptions.
(2) When the value of the main buffer is set, the backup buffer data is set. Lock the value of the main buffer.
(3) When the value of the main buffer is locked, the backup buffer data is set.
[0052]
[First Embodiment]
Next, a first embodiment according to the present invention will be described in detail with reference to the drawings (FIGS. 6, 8, and 9).
[0053]
FIG. 6 is a diagram for explaining processing in the first embodiment. In the first embodiment, the data area of the memory provided in the process cartridge is a 256-byte area represented by 00h to FFh, and data rewrite prohibition can be set for each byte. To do. Also, as bit information (data) stored in the memory, for example, “low toner amount” indicating that the remaining amount of developer in the process cartridge has decreased, and that the remaining amount of developer has been exhausted. Assume that there is “no remaining toner”.
[0054]
As shown in FIG. 6A, one of the double buffers has a minimum data size that can prohibit memory rewrite in order to set data rewrite prohibition for each bit information (data) as a main buffer. In order to expand and save to 1 byte in accordance with 1 byte, “low toner amount” is assigned to the 00h area, and “no remaining toner” is assigned to the 01h area. Furthermore, byte information indicating a reset state of arbitrarily set bit information (data) is “48h”, and byte information indicating a set state is “CAh”.
[0055]
The other of the double buffers shrinks two bit information (data) of “low toner amount” and “no toner amount” as a backup buffer and assigns them to one area of the address 10h. It is assumed that the most significant bit of the area of the address 10h is “low toner amount” and the next upper bit is “no remaining toner”. In the bit information (data), the set state is represented by “1” and the reset state is represented by “0”.
[0056]
In a new process cartridge, both “low toner level” and “no toner level” are in the reset state, so the data on the memory is “48h” where the address 00h indicates the reset state, and “48h” where the address 01h indicates the reset state. ”, The most significant bit of the address 10h, which is the shrunken information, is“ 0 ”, and the next higher bit is“ 0 ”.
[0057]
Here, when it is determined that “toner remaining amount” is low when the developer is reduced to a predetermined amount or less using this process cartridge, the data on the memory is “CAh” in which the address 00h indicates the set state. The address 01h is “48h” indicating the reset state, the most significant bit of the address 10h, which is the shrink information, is “1”, and the next higher bit is “0”. Here, the data at address 00h is locked, and rewriting is prohibited.
[0058]
Further, when the developer continues to decrease using the process cartridge and the remaining amount of developer becomes equal to or less than a predetermined amount as shown in FIG. 6B, it is determined that there is no toner remaining. In the memory, the address 00h remains “CAh” representing the set state, the address 01h becomes “CAh” representing the set state, and the most significant bit of the address 10h, which is the shrink information, remains “1”. The next upper bit is “1”. Here, the data at the address 01h is locked, and rewriting is prohibited.
[0059]
[Checksum]
Each of the double buffers includes checksum data as a means for error checking. Assume that the checksum data of the main buffer is stored in the area of address 0Fh, and the checksum data of the backup buffer is stored in the area of address 11h. Here, the checksum data of the main buffer is stored in the checksum calculation means after rewriting the data in the main buffer when “low toner” or “no toner” stored in the main buffer changes. It is rewritten to the value calculated by When the bit information (data) “low toner amount” and “no toner amount” stored in the area of the address 10h assigned to the backup buffer is rewritten, the checksum of the backup buffer is rewritten by the checksum calculation means. It is rewritten to the calculated value.
[0060]
Here, when it is detected that the process cartridge has been replaced after the power is turned on, the image forming apparatus reads all the values in the data area on the memory, and the checksum data stored in the checksum data area of each buffer is read. It is determined whether or not it matches the checksum (value obtained by adding the read values) calculated by the checksum calculation means in the printer control unit 204. If the checksum data does not match the calculated checksum on one side of the double buffer, the other checksum data on the double buffer is compared with the calculated value. As a result, if the checksum of the other buffer does not match, the data in this memory cannot be restored. However, if the checksum of the other buffer matches, the data in this memory can be restored using the data in the buffer with the matching checksum. That is, when the main buffer and the backup buffer are configured as described above, and the main buffer does not match the checksum, the data is repaired in the following procedure.
[0061]
FIG. 8 is a flowchart showing data restoration processing in the first embodiment. FIG. 9 is a diagram showing an example when data in the main and backup buffers is modified and locked.
[0062]
First, in step S801, an index n indicating the data area (n) of the main buffer and the bit area (n) of the backup buffer is initialized to “1”. Next, in step S802, it is determined whether the data area (1) of the main buffer is locked. If it is not locked, the process proceeds to step S803, and the amount of toner is reduced in the area of the main buffer data area (1) address 00h. It is determined whether 48h shown is set. As a result, if it is not in the set state, the process advances to step S804 to determine whether the bit in the bit area (1) of the backup buffer is set. As a result, if it is not in the set state, the process advances to step S805 to rewrite the area at address 00h in the data area (1) of the main buffer to the reset state. Next, in step S806, a checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten.
[0063]
Thus, in the case of steps S802 to S806, the data area (1) address 00h of the main buffer corresponds to the reset state or an abnormal value, and the bit information of the data area (1) of the backup buffer corresponds to the reset state. If so, the data in the data area (1) address 00h of the main buffer is rewritten to the reset state (00h). Next, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten.
[0064]
If the bit information in the bit area (1) of the backup buffer is set in step S804, the process proceeds to step S807, and the data in the data area (1) address 00h of the main buffer is rewritten to the set state (CAh). . In step S808, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten. In step S809, the data area (1) address 00h of the main buffer is set to the locked state.
[0065]
As described above, in the case of steps S804 to S807, the data area (1) address 00h of the main buffer corresponds to the reset state or an abnormal value, and the bit information of the bit area (1) of the backup buffer corresponds to the set state. In this case, the data area (1) of the main buffer (1) data at address 00h is rewritten to the set state (CAh), and the area at address 00h is rewritten to the lock state.
[0066]
FIG. 9 shows an example of the state of the main buffer and the backup buffer in the case of steps S804 → S807.
[0067]
In step S803, if the data area (1) address 00h of the main buffer is in the set state, the process advances to step S810 to set the data area (1) address 00h of the main buffer in the locked state. Next, in step S811, the checksum of the main buffer is calculated, and the data in the checksum storage area is rewritten. In step S812, the bit information in the bit area (1) of the backup buffer is rewritten to the set state. Next, in step S813, the checksum of the backup buffer is calculated, and the data in the checksum storage area is rewritten.
[0068]
As described above, in the case of steps S803 to S810, the data area (1) address 00h of the main buffer corresponds to the set state (CAh), and the bit information of the bit area (1) of the backup buffer is set. Rewritten to state.
[0069]
In step S802, if the address 00h of the data area of the main buffer is locked, the process proceeds to step S816, and it is determined whether the address 00h of the data area of the main buffer is set. As a result, if it is not set, it is determined that this memory cannot be restored. In other words, in the first embodiment, the data in the main buffer is locked only in the processes in steps S809 and S810 described above. In these cases, the data in the main buffer is in the set state (CAh). Because. If 00h of the data area of the main buffer is in the set state, the process proceeds to step S811, and the above processing is performed.
[0070]
Thus, in the case of steps S802 → S816, if the data area (1) of the main buffer corresponds to the locked state, it is determined whether the data area (1) address 00h of the main buffer is set, and the result If it is not in the set state, it is determined that recovery is impossible (NG).
[0071]
Next, when the above process is completed, in step S814, the index n is updated, and the index n (= 1) initialized in step S801 is updated (incremented to n = 2). In step S815, it is determined whether all repairs have been completed. If completed, the process ends. If not completed, the process returns to step S802 to repeat the above process.
[0072]
By executing the above procedure, data reflecting the latest information can be restored.
[0073]
Realization of these means is realized in the form of a program set in a microcomputer on the controller.
[0074]
[Second Embodiment]
Next, a second embodiment according to the present invention will be described in detail with reference to the drawing (FIG. 7).
[0075]
The data configuration on the memory mounted on the process cartridge in the second embodiment is the same as the data configuration described in the first embodiment. Here, differences from the first embodiment will be described.
[0076]
FIG. 7 is a diagram for explaining processing in the second embodiment. As shown in FIG. 7A, “low toner amount” and “no toner amount” stored in the address 00h corresponding to the main buffer and the address 01h are set, and at this time, shrinking corresponding to the backup buffer is performed. The data at the address 10h for storing the data is also in a state where both the “low toner amount” and the “no toner amount”, which are the shrunken data, are set. At this point, as shown in FIG. 7B, the data at address 00h and address 01h and the data at address 10h to which the shrink data of the backup buffer is allocated are locked, and rewriting is prohibited. Become.
[0077]
The checksum is the same as that in the first embodiment, and a description thereof is omitted.
[0078]
In the first and second embodiments, the data stored in the memory provided in the cartridge has been described as an example of data with a small amount of toner and no toner remaining. However, the data to be stored is limited to this. It may be information relating to the cartridge such as information indicating whether the cartridge is new or the number of prints printed using the cartridge.
[0079]
As described above, according to the embodiment, the data area of the memory can be used efficiently, and a plurality of pieces of information can be acquired collectively by accessing one shrinked address. This has the effect of reducing the number of accesses to the memory. In addition, proper data restoration can be realized.
[0080]
Even if the present invention is applied to a system composed of a plurality of devices (for example, a host computer, an interface device, a reader, a printer, etc.), it is applied to an apparatus (for example, a copier, a facsimile machine, etc.) composed of a single device. It may be applied.
[0081]
Another object of the present invention is to supply a recording medium in which a program code of software realizing the functions of the above-described embodiments is recorded to a system or apparatus, and the computer (CPU or MPU) of the system or apparatus stores the recording medium in the recording medium. Needless to say, this can also be achieved by reading and executing the programmed program code.
[0082]
In this case, the program code itself read from the recording medium realizes the functions of the above-described embodiment, and the recording medium storing the program code constitutes the present invention.
[0083]
As a recording medium for supplying the program code, for example, a floppy (registered trademark) disk, a hard disk, an optical disk, a magneto-optical disk, a CD-ROM, a CD-R, a magnetic tape, a nonvolatile memory card, a ROM, or the like is used. be able to.
[0084]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) operating on the computer based on the instruction of the program code. It goes without saying that a case where the function of the above-described embodiment is realized by performing part or all of the actual processing and the processing is included.
[0085]
Further, after the program code read from the recording medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing and the functions of the above-described embodiments are realized by the processing.
[0086]
【The invention's effect】
As described above, according to the present invention, the data area of the memory can be used efficiently, and when the memory data abnormality occurs, the state of the memory can be restored in a form close to the latest state. .
[Brief description of the drawings]
FIG. 1 is a general schematic diagram of a laser printer using electrophotographic technology.
FIG. 2 is a diagram showing a configuration of a control unit of the laser printer shown in FIG.
FIG. 3 is a diagram simply showing data area allocation;
FIG. 4 is a diagram showing a state of data restoration in the present embodiment.
FIG. 5 is a flowchart showing data restoration processing in the present embodiment.
FIG. 6 is a diagram for explaining processing in the first embodiment;
FIG. 7 is a diagram for explaining processing in the second embodiment;
FIG. 8 is a flowchart showing data correction processing in the first embodiment.
FIG. 9 is a diagram showing an example when data in main and backup buffers is modified and locked.
FIG. 10 is a schematic diagram of a laser printer using electrophotographic technology.

Claims (7)

A memory that is detachably attached to the image forming apparatus and is mounted on a cartridge that stores developer; a first storage area that stores information relating to the amount of the developer stored in the cartridge; A memory having a second storage area for storing backup information for backing up the information stored in the one storage area;
In the first storage area, each of first information indicating the remaining amount of the developer and second information indicating that the amount of the developer has decreased is stored as byte-size information having a predetermined number of bits, In the second storage area, the backup information of the first information is stored as information of the same byte size as the first information of the first storage area, and the backup information of the second information is memory and to store one bit of information indicating that the second information is stored in the first storage area. Further, third information indicating that the developer has run out is stored in the first storage area in the byte size,
In the second storage area, wherein as the backup information of the third information, claims wherein the third information in the first storage area and to store the 1-bit information indicating that the stored The memory according to 1. Before Stories second storage area, the provided second information is 1-bit information indicating that the stored is stored, and the first predetermined information as the second information in the storage area If not stored, it stores the first information the preset as the second information in the storage area, the inhibit rewriting a storage area for storing the second information in the first storage area The memory according to claim 1, wherein: A memory that is detachably attached to the image forming apparatus and is mounted on a cartridge that stores developer; a first storage area that stores information relating to the amount of the developer stored in the cartridge; A storage method for a memory having a second storage area for storing backup information for backing up information stored in one storage area,
In the first storage area, each of first information indicating the remaining amount of the developer and second information indicating that the amount of the developer has decreased is stored as byte-size information having a predetermined number of bits,
In the second storage area, the backup information of the first information is stored as information of the same byte size as the first information of the first storage area, and the backup information of the second information is A memory storage method comprising storing 1-bit information indicating that the second information is stored in the first storage area . Further, third information indicating that the developer has run out is stored in the first storage area in the byte size,
In the second storage area, wherein as the backup information of the third information, claims wherein the third information in the first storage area and to store the 1-bit information indicating that the stored 5. A memory storage method according to 4. Before Stories second storage area, wherein said 1-bit information the second information indicates that the stored is stored, and predetermined information as the second information in the first storage area If is not stored, the first of the stores preset information as the second information in the storage area, it prohibits rewriting the storage area storing the second information in the first storage area The memory storage method according to claim 5, wherein: A memory mounted on a cartridge that is detachably mounted on the image forming apparatus, the first storage area storing a plurality of types of information related to the cartridge, and the information stored in the first storage area being backed up A memory having a second storage area for storing backup information for
In the first storage area, each of the plurality of types of information is stored as byte-size information having a predetermined number of bits,
In the second storage area, the first storage is used as the backup information of the information indicating the remaining amount of the developer among the plurality of types of information or the number of images formed using the cartridge. Information indicating the remaining amount of the developer stored in the area or information on the number of images formed using the cartridge is stored in the same byte size, and the developer is reduced among the plurality of types of information. As information indicating that the developer has run out, information indicating that the developer has run out, or information indicating whether or not the cartridge is new , the amount of the developer in the first storage area is small. information indicating that became, or information indicating that the developer is used up, or, 1-bit information indicating that the cartridge is stored as information indicating whether or not new Memory and to store a.

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