JP2003140977A - Device management apparatus, device management method, and computer readable storage medium storing program for executing the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a device management apparatus capable of surely saving and reading out the use amount of a device with a small number of non-volatile memories without exceeding a write frequency limit of the non-volatile memory and without the need of configuration for detecting the off-state of a power supply. SOLUTION: This device management apparatus includes a measuring means 11 for measuring the use amount of the device or a unit connected to the device, and a non-volatile memory 12 for saving the use amount and limiting the write frequency in every area. The apparatus further includes an area select means 13 for selecting two or more of areas having an integral multiple of size determining the limited write frequency in the non-volatile memory in every user amount, an arithmetic means 14 for obtaining a value saved in each area in every area selected by the area select means, a comparing means 15 for comparing the value obtained by the arithmetic means with the value not saved in the area, and a control means for controlling to save the value obtained by the arithmetic means in the concerned area if the values are different, and not to save the value if the values are not different.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device management apparatus, a device management method, and a computer-readable storage medium storing a program for executing the method, and more particularly to an image forming apparatus such as a scanner, a printer, a copying machine, or the like. The present invention relates to a device management apparatus for measuring and storing the usage status such as the number of times of use and the usage time of each part of the device or a unit connected to the device, and performing maintenance and inspection and management of replacement time of parts and units.

[0002]

2. Description of the Related Art Generally, an image forming apparatus has a portion that is consumed, worn, deteriorated, or the like depending on the use of the apparatus. Since their service lives may be shorter than the service life of the entire image forming apparatus, these parts can be replaced.
Further, recently, there are devices that can be replaced as a unit including two or more parts that need to be replaced. As such a machine, for example, in a unit used in an image forming apparatus, a replaceable unit has a different number of printable sheets until the end of its life and a usable period depending on characteristics of each unit. The number of printable sheets, the number of uses, and the like are set for each. The number of times of use varies depending on the property of each unit, but is, for example, the number of rotations of the shaft in the unit.

By the way, the life of each of these units may be determined by a sensor or the like, or by a counter. Moreover, these may be combined. As an example of when the life of a certain unit is judged by the counter, the number of prints made by using that unit is stored in the main body or the nonvolatile RAM provided in the unit, and the life threshold set in advance is set at a certain timing. Compare with a certain number of sheets,
When the life threshold is exceeded, the life is displayed and the unit is replaced. This counter can be the number of sheets,
It may be the number of movements of a movable part such as a shaft or a clutch of a certain unit.

Further, as an example in which the life of a certain unit is judged by a sensor, a physical quantity that changes due to the use of the unit is detected by the sensor, and the physical quantity detected by the sensor is compared with a preset life threshold. When the life threshold is exceeded, the life is displayed and the unit is replaced.

Further, as an example in which the life of a certain unit is judged by using a counter and a sensor in combination, a physical quantity that changes depending on the use of the unit is detected by the sensor, and the physical quantity detected by the sensor and a preset physical quantity life are set. The threshold value is compared, and the counter is incremented only when the physical quantity life threshold value is exceeded. This counter
The number of prints printed by using the unit may be used, or the number of movements of a movable part such as a shaft or a clutch of a certain unit may be used. When this counter exceeds a preset life threshold value, the fact that the life has expired is displayed and the replacement of the unit is urged.

Depending on the unit judged to have reached the end of life by these methods, the printing operation may be stopped after the end of life. When the unit is replaced, the new product detection unit determines that the unit is new, and resets the counter and initializes the unit. In addition, the life of the entire device may be determined. In that case, the life is judged by a counter, a sensor, a combination thereof and the like, similarly to the judgment of the life of each unit. In addition to the life, the near life may be judged. The near-life is a state in which the life is about to come, though it is not yet a life. For example, the life value of a unit that can be used for printing 100,000 sheets is 100,000,
The near life value is, for example, 95,000 sheets.

Conventionally, the amount of use of a certain unit is measured and the life of the unit is determined as follows. That is, the usage amount of this unit is determined by the rotation speed of the motor driving the unit. This motor rotates 100 times per 1 second printing operation, and the life of this unit is 6,0
Assume that it is 00,000 rotations. This is 0x5 in hexadecimal
B, 8D, 80. When this unit reaches the end of its life, it will not be driven unless this unit is replaced. Therefore, a value exceeding this rotation speed is not stored in the non-volatile memory. So 0 to 6,00
Provide a counter that can count up to 0,000. When this count value reaches 6,000,000, the control means of the device judges that the unit is at the end of life, does not print, and displays on the display of the device that the unit is at the end of life and should be replaced. To do.

FIG. 8 is a diagram showing a memory map of a conventional nonvolatile memory. As shown in the figure, the number of rewritable times of the nonvolatile memory is determined for each byte, and is assumed to be 1 million times. Therefore, in hexadecimal 0 to 0x5B, 8D, 8
In order to count one by one up to 0, six 3-byte counters are provided at addresses 0 to 17 which are counter areas on the nonvolatile memory. For the processing of the control means, a RAM area of 4 bytes and a non-volatile memory area for area switching variables are secured at address 18 in addition to the non-volatile memory area for storing the number of rotations of the motor. The area switching variable determines which of the six counters on the non-volatile memory is used.

As an example of actually counting using this non-volatile memory, the following method proposed in Japanese Patent Laid-Open No. 6-138730 (hereinafter referred to as Conventional Example 1) has been performed. The counter value in the initial state is 0, and counting up is performed by use. It is assumed that the initial value of the area switching variable is 0. It is assumed that 0 is written in all areas in the counter area on the nonvolatile memory. The count value is written to the non-volatile memory each time the count is incremented by one, and the number of writable times in the non-volatile memory is one million. Therefore, the area is switched every one million times of writing. When switching, the pointer designating the storage area is updated.
When the number of rotations of the motor is between 0 and 1,000,000, 0 in the non-volatile memory
Write a value from 0 to 1,000,000 from the 0th area to the 2nd area. When counting up from 1,000,000 to 1,000,001, write 1 in the area switching variable, and write the value of 1 which is the value obtained by subtracting 1,000,000 * area switching variable from the counter value in the first area, addresses 3 to 5. . 1,000,002-2,00
Between 0 and 000, write the value of 2 to 1,000,000, which is the value obtained by subtracting 1,000,000 * 1 from the counter value, at addresses 3 to 5, which is the first area of the nonvolatile memory. Similarly, when counting up from the value of the integral multiple of 1,000,000 where the area switching occurs to the value of the integral multiple of 1,000,000 + 1, the area switching variable is incremented by 1 and 1 is written in the next area. When area switching does not occur, write the value of 2 to 1,000,000, which is the value obtained by subtracting 1,000,000 * area switching variable from the counter value.

In order to read the count value stored in the non-volatile memory in this way, the following formula is used.

Count value = value of area switching variable × 1,000,00
Value of 0 + area switching variable th counter area

By doing so, the amount of use of the entire apparatus, the parts of the apparatus, and the units connected to the apparatus, that is, the number of prints and the number of rotations are accurate, without performing the writing exceeding the writing number limit of the nonvolatile memory. Can be counted, saved, and displayed. In the above-mentioned conventional example 1, 1
Although the count value was written in the nonvolatile memory each time the count was incremented, the same effect can be obtained by writing the count value in every predetermined count as proposed in Japanese Patent Laid-Open No. 5-249769 (hereinafter referred to as Conventional Example 2). .

[0013]

However, according to any of the conventional methods described above, a nonvolatile area of 19 bytes is required as shown in the following equation.

Counter area + switch variable area = 3 × 6 + 1
= 19

Therefore, for example, in the image forming apparatus, it is necessary to store the usage amount of the entire device such as the total number of prints, the usage amount of each unit, and the usage amount of each component. Particularly, the color printer has several components having the same function. , The unit is YM
It exists for each color of CK and requires a larger amount of non-volatile memory to store those values.

The present invention is intended to solve these problems, and does not require a configuration for detecting power OFF without exceeding the write count limit of the non-volatile memory, and reliably uses the device with a small non-volatile memory. An object of the present invention is to provide a device management apparatus capable of storing and reading amounts, a device management method, and a computer-readable storage medium storing a program for executing the method.

[0017]

In order to solve the above-mentioned problems, the device management apparatus of the present invention includes a nonvolatile memory,
When the usage amount of a device or a unit connected to the device is stored in an area that is an integer multiple of 2 or more of the size of the restricted writing frequency, the writing frequency in the nonvolatile memory is determined for each usage amount. An area that is an integer multiple of 2
The area selecting means to be selected above, the calculating means for obtaining the value to be stored in each area for each area selected by the area selecting means, and each area selected by the area selecting means,
When the value obtained by the calculation means is different from the value currently stored in the area, and the value is different for each area selected by the area selection means based on the comparison result of the comparison means. Is characterized in that it has a control means for storing the value obtained by the arithmetic means in the area and controlling not to save the value in the area if there is no difference. Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

A device management apparatus according to another invention has a measuring means for measuring the amount of use of the device or a unit connected to the device, the measuring device exists in the unit, and the number of times of writing is limited for each area. A device management apparatus that manages the usage state of a device or unit based on the usage amount stored in the nonvolatile memory, and stores the device or unit in a region of the nonvolatile memory that is an integer multiple of 2 or more of the size that determines the number of times of writing that is limited. When the usage amount of the unit is stored, for each usage amount, an area selecting unit that selects two or more areas that are integer multiples of the size in which the number of writings in the nonvolatile memory is determined, and for each area selected by the area selecting unit. Calculating means for obtaining a value to be stored in the area, and for each area selected by the area selecting means, the value obtained by the calculating means and the value currently stored in the area. For each area selected by the comparing means and the area selecting means, based on the comparison result of the comparing means, if the values are different, the value obtained by the calculating means is stored in the area and is not different. In this case, it has a control means for controlling so as not to save in the area.
Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

Further, the non-volatile memory is preferably an EEPROM or a flash ROM.

Further, according to the device management method as another invention, an area that is an integral multiple of the size in which the number of writes is determined in the nonvolatile memory existing in the device or the unit connected to the device is set to 2 for each usage amount. For each of the selected areas, the value to be stored in the selected area is calculated, the calculated value is compared with the value currently stored in the selected area, and the selected value is selected. For each area, based on the comparison result, if the value is different, save the obtained value in the area,
If they do not differ, it is characterized in that they are controlled not to be stored in the area. Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

Another feature of the present invention is a computer-readable storage medium that stores a program for executing the above-mentioned device management method. Therefore, by further using the medium in which the program for executing the device management method of the present invention is stored, the device for constructing the device management system can be generally used without changing the existing system.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION A device management apparatus of the present invention shown in FIG. 1 stores a usage amount of a device or a unit connected to the device and a usage amount, and stores the usage amount, and writes the number of times for each area. Is a non-volatile memory 12 that is included in a device or a unit connected to the device, and is a device management device that manages a usage state of the device or the unit based on a usage amount. In an area that is an integer multiple of 2 or more that is the size that limits the number of writes,
When storing the amount of use of the device or the unit connected to the device, the region selecting means 13 for selecting two or more regions, which are integer multiples of the size in which the number of times of writing in the nonvolatile memory 12 is determined, for each amount of use, and a region For each area selected by the selecting means 13, a calculating means 14 for obtaining a value to be stored in each area, and for each area selected by the area selecting means 13, the value obtained by the calculating means 14 and the area For each area selected by the comparing means 15 for comparing with the currently stored value and the area selecting means 13, based on the comparison result of the comparing means, if the values are different, the value obtained by the calculating means Is stored in the area, and if not different, it is controlled not to be stored in the area.
Have and.

[0023]

FIG. 2 is a sectional view showing the arrangement of an image forming apparatus to which a device management apparatus according to an embodiment of the present invention is applied. In the following, the device in this embodiment will be described as an image forming apparatus, but the device is not limited to this and can be applied to various devices. In the figure, during printing operation,
The transfer paper 102 is fed from the paper supply unit 101, the transfer paper 102 is conveyed by the transfer unit 103, and the YMCK color toners are sequentially transferred to the transfer paper 102 by the YMCK developing units 104 to 107 and the photoconductor drums 108 to 111. Transcribed. Next, the transfer paper 102 on which the toner has been transferred is conveyed to the fixing unit 112, and the fixing unit 112 performs fixing by heat and pressure. Finally,
The transfer paper 102 on which the toner is fixed is ejected to the paper ejection tray 113. The consumed toner is supplied from the toner bottle 114 to the developing units 104 to 107. Of these, the photoconductor drum 10 is supplied with toner from the toner bottle 114 and is irradiated with light by the optical unit 115.
Developing units 104 to 1 for supplying toner to 8 to 111
There are four 07 corresponding to the toner of each color of YMCK. Of these, the K developing unit 107 is driven by a black developing motor (not shown), and the YMC developing units 104 to 106 are driven by a color developing motor (not shown). YMCK developing units 104 to 107
There is a clutch (not shown) for each color between the developing motor and the developing motor (not shown).
The drive transmission to the developing units 104 to 107 is controlled. When the clutch is turned on, the drive of the developing motor is transmitted to the developing units 104 to 107 and the clutch is turned on.
When FF is performed, the driving of the developing motor is performed by the developing unit 104.
Not transmitted to ~ 107.

In the printing operation of the color printer, there are cases in which two kinds of printing operations, that is, monochrome printing and color printing are performed. During the monochrome printing operation, the color developing motor is not driven, and image formation is performed by the K photosensitive drum 111, the K developing unit 107, the black developing motor (not shown) used to drive the K developing unit 107, and the K developing unit 107. The developing clutch (not shown) is activated. During the color printing operation, in addition to these, YMC developing units 104-1
06, YMC photosensitive drums 108-110, and YMC developing units 104-106 are driven by a color developing motor (not shown). As a matter of course, depending on the configuration of the device, these parts that operate at the same time as printing,
Although the units and the like are different, they are omitted because they are not related to the essence of the present invention.

FIG. 3 is a time chart showing an image forming operation for each of the used amounts YMCK in this embodiment. At the time of printing, the color developing motor and the black developing motor are driven (time t ₀ ). This motor is 100 per second operation
It rotates, and the gear ratio for driving the developing motor and developing unit is 1
Suppose That is, when the developing motor makes one rotation, the developing unit is driven once. The color developing motor is driven, and the Y developing clutch is turned on at a timing when a certain speed is reached (time t ₁ ). The developing clutch of M is turned on 400 msec after the developing clutch of Y is turned on (time t ₂ ). The developing clutch for C is turned on 400 msec after the developing clutch for M is turned on (time t ₃ ). The developing clutch for K is turned on 400 msec after the developing clutch for C is turned on (time t ₄ ). 3000 msec after each clutch is turned on
It is OFF after the (time _t 5 _~t 8). Further, it is assumed that each developing motor is turned off 5 seconds after being turned on (time t ₉ ). During this time, each YMCK developing unit has 10
It means that 0 × 3000/1000 = 300 rotations.

The YMCK developing unit has a new article detecting mechanism (not shown), and it can be seen that a new article is set. When it is detected that a new product has been set, the number of used sheets of the unit and the rotation number counter are reset. In this embodiment, the life of the developing unit is 6,000,00.
If it is 0 rotation, the counter value of the developing unit is 60,
When it reaches, 000,000, the control means of the device judges that the unit is at the end of life, does not perform the printing operation, and displays on the display unit of the device that the unit is at the end of life and should be replaced. Since the printing operation and the warm-up operation are prohibited after the end of life, the counter value of the developing unit should be able to count up to this value. Further, it is assumed that the nonvolatile memory used in this embodiment has a writable count of 1,000,000.

FIG. 4 is a flow chart showing the count-up operation of the developing unit in this embodiment. First,
Both the motor that drives the unit and the clutch that transmits the drive of the motor to the unit are turned off every 10 ms.
N is checked (steps S101, S10
2) When both are ON, the counter is incremented by 1 and writing to the nonvolatile memory is performed by the method described below (step S101; YES, step S102; YES, steps S103, S104).

FIG. 5 is a diagram showing an example of a memory map in this embodiment. In the figure, addresses 0 to 6 are used as a counter area, and address 7 is used as an area switching variable area. The area switching variable is for determining which address in the counter area on the non-volatile memory is used as the counter. The underlined numerical value in the square indicates that it corresponds to the corresponding address in the RAM area 2.

A method of storing the rotation speed of the Y developing unit will be described below with reference to FIG. Immediately after the power of the device is turned on, the number of revolutions when the power was turned off last time is calculated. First, the value of the area switching variable is read, and the 3-byte value from the area switching variable address of the counter area is sequentially copied from the address 0 to the address 2 of the RAM area 2. However, since there is a case where the 3-byte counter area cannot be secured after the area switching variable address of the counter area on the nonvolatile memory, the RAM area 2 and the counter area are made to correspond to each other as follows.

When the area switching variable is 0 to 4, the value of address 0 of the RAM area 2 = the value of the area switching variable of the area The value of the address 1 of the RAM area 2 = (the area switching variable of the area +
1) Value of address Value of address 2 in RAM area 2 = (area switching variable of area +
2) When the value area switching variable of the address is 5, the value of address 0 in RAM area 2 = the value of address 5 in RAM area 2 = the value of address 6 The value of address 2 in RAM area 2 = the value of 0 When the value area switching variable is 6, the value of address 0 of RAM area 2 = the value of address 6 of RAM area 2 = the value of address 0 The value of address 2 of RAM area 2 = the value of address 1

Next, the RAM at this time is calculated by the following equation.
The value of the area 1 and the counter value are obtained. RAM area 1 value = RAM area 2 address 0 value x 256 ^ 2
+ Value at address 1 in RAM area 2 x 256 ^ 1 + Value at address 2 in RAM area 2 Counter value = Area switching variable x 900,000 + Value in RAM area 1

For example, when the power is turned on, the value of the area switching variable on the nonvolatile memory is 1, and the value of the first address in the counter area is 0x0.
The value of address 9 and 2 is 0x27, and the value of address 3 is 0xC0. At this time, the value of RAM area 2 is 0x0.
9, the value at address 1 is 0x27, and the value at address 2 is 0xC0. The value of the RAM area 1 at this time is calculated as 600,000 by the above formula. The counter value is calculated as 1,500,000 by the above formula.

The control for counting up the number of rotations by driving the motor will be described below. The count value is incremented by 1 by rotation, and the counter value is 1,500,000 to 1,500,00
Suppose it becomes 1.

First, a quotient and a remainder obtained by dividing 1,500,000, which is a value obtained by subtracting 1 from the counter value 1,500,001, by the area switching threshold 900,000, are obtained. The quotient is 1 and the remainder is 600,00. Since 600,001, which is a value obtained by adding 1 to the other, is not 1, the area switching variable does not change.

Next, 600,001 which is a value obtained by adding 1 to the above calculation is stored in the RAM area 1. At this time, R
A value obtained by dividing the value of AM1 by 256 ^ 2 is obtained, and the quotient is taken as the value of address 0 in the RAM area 2. In addition, the remainder of this division is 256 ^ 1
A value obtained by dividing by is obtained, the quotient is taken as the value of the first address in the RAM area 2, and the quotient is taken as the value of the second address in the RAM area 2. RAM
When the value of area 1 is 600,001, RAM is calculated by the above calculation.
The value of address 0 in area 2 is 0x09, the value of address 1 is 0x27, and the value of address 2 is 0xC1. Finally, the value of 3 bytes in the RAM area 2 is compared with the value of 3 bytes from the area switching variable address of the counter area on the non-volatile memory one byte at a time, and if the values are different, the value of that address in the RAM area 2 is non-volatile. Write to the corresponding address in the counter area on the memory. If the values do not differ, writing to the non-volatile memory is not performed. However, if the 3-byte counter area cannot be secured after the area switching variable address of the counter area on the nonvolatile memory,
After the last address of the counter area, addresses 0 and later are associated with the RAM area 2.

Since the value of the area switching variable is 1, the value 0x09 at address 1 in the counter area on the nonvolatile memory is compared with the value 0x09 at address 0 in the RAM area 2. Since this value does not differ, the first address in the counter area on the nonvolatile memory is not rewritten. The value 0x27 at address 2 in the counter area on the nonvolatile memory is compared with the value 0x27 at address 1 in RAM area 2. Since this value does not differ, the second address of the counter area on the non-volatile memory is not rewritten. The value 0xC0 at address 3 in the counter area on the non-volatile memory and the value at address 1 in RAM area 2
Compare 0xC1. Since this value is different, 0xC1 is written in address 3 of the counter area on the nonvolatile memory.

The amount of use of the non-volatile memory in the above case is calculated by the following equation and is 8 bytes.

Maximum counter value / (area switching threshold value / counter value increment in one rewriting) + area for variable area variable = [6,000,000 / (900,000 / 1)] + 1 = 8 where the operator [] is It represents an operation that rounds up the number after the decimal point in [].

The maximum number of times of rewriting of the nonvolatile memory in the above case will be calculated. Each address of the counter area of the non-volatile memory is used as an area of 0th address, 1st address, and 2nd address of the RAM area 2, and once each is used as an upper limit. In this embodiment, one write is performed once.
Since it is incremented by one, when it is used as a portion corresponding to address 0 of RAM area 2, it is 0 to 900,000 and 90
0 to [900,000 / 256] when it is used as a part corresponding to the first address of RAM area 2 after rewriting 000 times.
When it is used as a part corresponding to the second address of RAM area 2, there are 3516 rewrites in 0 to [900,000 / 256 ^.
There are 14 rewrites in [2]. Here, the operator [] represents an operation of rounding up the fractional part of the numerical value in []. When the above is summed up, 903,530 rewrites occur. This is less than 1,000,000 rewritable times of the above-mentioned non-volatile memory, and correct reading and writing can be performed.

In principle, the counter area on the non-volatile memory corresponding to the RAM area 2 is continuously used for 3 bytes, but it is not always necessary to continuously use the counter area, and as shown in FIG. Needless to say, may be assigned.

FIG. 6 is a diagram showing another example of the memory map in this embodiment. In the figure, addresses 0 to 6 are used as a counter area, and address 7 is used as an area switching variable area. The area switching variable is for determining which address in the counter area on the non-volatile memory is used as the counter. Similar to FIG. 4, the underlined numerical values in the squares correspond to the corresponding addresses in the RAM area 2. Others are the same as the example shown in FIG.

Next, FIG. 7 is a block diagram showing the system configuration of the present invention. That is, this figure shows the hardware constructed from a microprocessor or the like that executes software according to the method for performing device management in the above embodiment. In the figure, the device management system includes an interface (hereinafter abbreviated as I / F) 71, a CPU 72, and an RO.
M73, RAM74, display device 75, hard disk 7
6, a keyboard 77 and a CD-ROM drive 78. Also, prepare a general-purpose processing device,
A readable recording medium such as a CD-ROM 79 stores a program for executing the device management method of the present invention. Further, a control signal is input from an external device via the I / F 71, and the keyboard 77 causes a command from an operator or automatically starts the program of the present invention. And
The CPU 72 performs a control process associated with the above-described device management method according to the program, stores the process result in a storage device such as the RAM 74 or the hard disk 76, and outputs the result to the display device 75 or the like as necessary. As described above, by using the medium in which the program for executing the device management method of the present invention is stored, it is possible to construct a device management system for general purpose without changing the existing system.

It is needless to say that the present invention is not limited to the above embodiments, and various modifications and substitutions can be made within the scope of the claims.

[0044]

As described above, the device management apparatus of the present invention is connected to the device or the device in an area of the nonvolatile memory, which is an integral multiple of 2 or more of the size for which the limited number of times of writing is determined. When the usage amount of the unit is stored, for each usage amount, an area selecting unit that selects two or more areas that are integer multiples of the size in which the number of writings in the nonvolatile memory is determined, and for each area selected by the area selecting unit. Calculating means for obtaining a value to be stored in each area, and comparing means for each area selected by the area selecting means, for comparing the value obtained by the calculating means with the value currently stored in the area, For each area selected by the area selecting means, based on the comparison result of the comparing means, if the value is different, the value obtained by the calculating means is stored in the area, and if not, the value is concerned. It is characterized by a control means for controlling so as not to store the frequency. Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

Further, the device management apparatus of another invention has a measuring means for measuring the amount of use of the device or a unit connected to the device, is present in the unit, and the number of writing times is limited for each area. A device management apparatus that manages the usage state of a device or unit based on the usage amount stored in the nonvolatile memory, and stores the device or unit in a region of the nonvolatile memory that is an integer multiple of 2 or more of the size that determines the number of times of writing that is limited. When the usage amount of the unit is stored, for each usage amount, an area selecting unit that selects two or more areas that are integer multiples of the size in which the number of writings in the nonvolatile memory is determined, and for each area selected by the area selecting unit. Calculating means for obtaining a value to be stored in the area, and for each area selected by the area selecting means, the value obtained by the calculating means and the value currently stored in the area. For each area selected by the comparing means and the area selecting means, based on the comparison result of the comparing means, if the values are different, the value obtained by the calculating means is stored in the area and is not different. In this case, it has a control means for controlling so as not to save in the area.
Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

Further, the non-volatile memory is preferably an EEPROM or a flash ROM.

According to the device management method as another invention, an area which is an integral multiple of the size in which the number of writes is determined in the nonvolatile memory existing in the device or the unit connected to the device is set to 2 for each usage amount. For each of the selected areas, the value to be stored in the selected area is calculated, the calculated value is compared with the value currently stored in the selected area, and the selected value is selected. For each area, based on the comparison result, if the value is different, save the obtained value in the area,
If they do not differ, it is characterized in that they are controlled not to be stored in the area. Therefore, it is possible to surely store and read the usage amount of the device with a small nonvolatile memory without exceeding the limit of the number of times of writing in the nonvolatile memory and without requiring a configuration for detecting the power OFF.

Another feature of the present invention is a computer-readable storage medium that stores a program for executing the above-described device management method. Therefore, by further using the medium in which the program for executing the device management method of the present invention is stored, the device for constructing the device management system can be generally used without changing the existing system.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a device management apparatus according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration of an image forming apparatus to which the device management apparatus according to an embodiment of the present invention is applied.

FIG. 3 is a time chart showing an image forming operation for each of the used amounts YMCK in this embodiment.

FIG. 4 is a flowchart showing a count-up operation of the developing unit in this embodiment.

FIG. 5 is a diagram showing an example of a memory map in this embodiment.

FIG. 6 is a diagram showing another example of a memory map in the present embodiment.

FIG. 7 is a block diagram showing a system configuration of the present invention.

FIG. 8 is a diagram showing a memory map of a nonvolatile memory in a conventional example.

[Explanation of symbols]

11; measuring means, 12; non-volatile memory, 13; area selecting means, 14; computing means, 15; comparing means, 16; control means.

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Claims (6)

[Claims] 1. A measuring device for measuring a usage amount of a device or a unit connected to the device, and a non-volatile memory storing the usage amount and having a limited number of writing operations for each area. In the device management apparatus that manages the usage state of the device or the unit based on the above, in the non-volatile memory, an area that is an integer multiple of 2 or more of a size in which the number of times of writing that is limited is determined is the area of the device or the unit. In saving the usage amount, for each usage amount, an area selecting unit that selects two or more areas that are integer multiples of a size in which the number of writings in the nonvolatile memory is determined, and for each area selected by the area selecting unit Calculating means for obtaining a value to be stored in each area, and for each area selected by the area selecting means, the value obtained by the calculating means and the value currently stored in the area. Comparing means for comparing the value with each of the areas, for each area selected by the area selecting means, based on the comparison result of the comparing means, if the value is different, the value obtained by the calculating means A device management apparatus, comprising: a control unit that saves the data in an area and controls not to save in the area when there is no difference. 2. The usage amount stored in a non-volatile memory, which is provided in the unit and has a writing count limited for each area, has a measuring unit for measuring the usage amount of the device or a unit connected to the device. In a device management device that manages a usage state of the device or the unit based on the above, the use of the device or the unit in an area that is an integer multiple of 2 or more of a size in which the number of times of writing that is limited is determined in the nonvolatile memory. When storing the amount, for each usage amount, region selection means for selecting two or more regions of an integral multiple of the size in which the number of writings in the nonvolatile memory is determined, and for each region selected by the region selection means, A calculation means for calculating a value to be stored in the area, and a value currently calculated in the area and the value calculated by the calculation means for each area selected by the area selection means A comparison means for comparing the value with each other, for each area selected by the area selection means, based on the comparison result of the comparison means, if the values are different, the value obtained by the calculation means A device management apparatus, comprising: a control unit that saves the data in the area and controls not to save in the area when there is no difference. 3. The device management apparatus according to claim 1, wherein the non-volatile memory is an EEPROM. 4. The device management apparatus according to claim 1, wherein the nonvolatile memory is a flash ROM. 5. The amount of use of a device or a unit connected to the device is measured, and the measured amount of use is stored in a non-volatile memory that exists in the device or the unit and has a limited write count for each area. However, in the device management method for managing the usage status of the device or the unit based on the usage amount, two or more integer multiples of the size in which the number of writes in the nonvolatile memory is determined are selected for each usage amount. , For each selected area, find the value to be saved in that area, and for each selected area, compare the calculated value with the value currently saved in that area, and for each selected area Further, based on the comparison result, the device management method is characterized in that if the values are different, the obtained value is stored in the area, and if not, it is not stored in the area. 6. For each usage amount, two or more areas of an integral multiple of a size in which the number of times of writing in the nonvolatile memory is determined are selected,
For each selected area, find the value to save in that area,
For each selected area, compare the calculated value with the value currently stored in the area, and for each selected area, based on the comparison result, if the values are different, the calculated value Is stored in the area and is controlled not to be stored in the area if it is not different. A computer-readable storage medium storing a program for executing a device management method.