JPH0550787B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a counter device for counting numerical values, and particularly to a counter device suitable for counting the number of prints of an electrophotographic copying machine or a page printer.

[Prior art]

Conventionally, as this type of device, a mechanical counter that is a combination of an electromagnetic counter and a cam has been used, but recently, microcomputer-controlled electronic counters have become popular. This counter uses CMOS RAM (Random Access Memory) or RAM built into CMOS CPU (Central Processing Unit) as a means of storing count values, and this RAM
Data is lost when the power is cut off, so it is backed up using a lithium battery or the like. Since this counter can use a 7-segment display made of light emitting diodes, it has the advantage of good display quality and the ability to exchange data with other devices.

[Problems with conventional technology]

However, the above-mentioned counter had the following drawbacks.

(1) When the power is turned off, a sequence is required for the power supply to prohibit access to RAM, or for CPUs with built-in RAM to change the CPU from an operational standby state to a sleep state in which only the RAM is backed up. That is, when switching to a backup power source when the power is cut off, time is required to save data in the RAM. Specifically, it monitors the voltage of the main power supply and saves data in RAM before the main power supply is completely shut off. Therefore, the configuration of the device becomes complicated,
The cost is also high.

(2) It requires a backup battery, and since the battery has a limited lifespan, it must be replaced periodically. Furthermore, if the battery is not replaced, or if the battery is shunted or removed from the device when the main power is turned off, the data in the RAM will be lost.

(3) If the board on which the RAM is mounted breaks down and the board needs to be replaced, it is difficult to read the data stored in the RAM. Therefore, the data stored in RAM becomes unknown.
For example, the number of prints on an electrophotographic copying machine can be stored in RAM.
If it is remembered, the number of prints until the board is replaced will be unknown, which will hinder the lifespan management of the device.

[Purpose of the invention]

SUMMARY OF THE INVENTION In view of the above drawbacks, it is an object of the present invention to provide a counter device that can eliminate the need for backup batteries, has a simple device configuration, and does not cause data loss under any circumstances.

[Key points of the invention]

The above object, according to the present invention, includes a non-volatile storage means having a plurality of areas for storing count data, and reading current count data from an area of the non-volatile storage means in which the count data was last written. reading means; arithmetic processing means for performing arithmetic processing on the current count data in response to a count request; and each time new count data is generated by the processing of the arithmetic processing means, the new count data is This is achieved by providing a counter device characterized in that it includes writing means for writing into an area of the storage means different from the area from which the current count data was read.

[Embodiments of the invention]

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the counter device of the present invention. Note that this embodiment will be explained using a counter device used in an electrophotographic copying machine as an example.

In FIG. 1, a CPU (central processing unit) 1 controls the operation of the electrophotographic copying machine according to a control program stored in a ROM (read only memory) 2. In FIG. 3 is a RAM (Random Access Memory), and 4 is an EE-PROM (Electrically Erasable Programmable Read Only Memory), which has the function of electrically erasing and writing data. , EE−
By exchanging data between the PROM 4 and the CPU 1 through the data bus 5, a counter device for counting the number of prints of an electrophotographic copying machine is constructed.
CPU1 has internal program counter PC, stack S, register A, register B, register X,
It has a flag F and an arithmetic logic unit ALU, and controls the electrophotographic copying machine such as counting the number of prints as described above.

Further, 6 is an address decoder, which is connected to output latches 8 and 9 and input buffers 10 and 11 through an address bus 7. The output signal of the output latch 8 is input to a 7-segment display 12 using light emitting diodes, and is input to the CPU as described below.
Display the number of prints according to command 1. The output of the output latch 9 is outputted to a load 12, that is, each component such as a photoreceptor drive device, a developing device, etc., which performs an electrophotographic process. In addition, input buffers 10 and 11
The sensor output and the number of prints are inputted from an input section 15 consisting of various sensors 14 and a keyboard on an operation panel. The CPU 1 controls the printing of a set number of sheets based on this input, and also controls the operating conditions based on the sensor output.

Figure 2 shows the address map of CPU1, RAM3 is located at addresses 0000-0800, EE-
PROM4 is located at addresses 4000-4800.
Further, I/O is located at addresses 8000 to 8020, ROM2 is located at addresses C000 to FFFF, and other addresses are unused.

FIG. 3 shows the address map of the EE-PROM 4. As shown in the figure, EE-PROM4 is
It is divided into Area 1 to Area 256, and each area includes TOTLCNT, DRMCNT, LIFCNT,
It has data storage areas shown as DRALCNT and CNTCTW. TOTLCNT (total counter) stores the total number of copies printed by the electrophotographic copying machine and consists of 3 bytes. DRMCNT
(Drum counter) stores the number of prints on one photoreceptor and consists of 2 bytes. Since the photoreceptor in an electrophotographic copying machine has a limited lifespan, it is configured as a drum set that can be attached to and detached from the copying machine body.
When the photoreceptor reaches the end of its life, it is replaced. Therefore,
The number of prints of a drum set is stored in DRMCNT to manage its lifespan. LIFCNT (life counter) is used to store a flag for managing maintenance timing, and is 1 byte.
DRALCNT (drum alarm counter) is used to give advance notice before the aforementioned drum set reaches the end of its life, and is 1 byte. CNTCTW
will be described in detail later, but is used to change the counting method depending on the paper size (1 byte). In this way, the EE-PROM4 has a storage area for five types of data such as TOTLCNT in one unit area of 8-byte capacity.
Currently, the number of times PROM4 can be rewritten is limited to about 10,000 times. On the other hand, although the electrophotographic copying machine of this embodiment has a lifespan of 300,000 prints, the count data is
If it is rewritten to PROM, it will need to be rewritten 300,000 times. Therefore, by dividing the entire storage area of EE-PROM4 into 256 areas and shifting this storage area sequentially for each printing operation, it is possible to rewrite the entire 2.56 million times, that is, to count up to 2.56 million sheets. did.

FIG. 4 shows the address map of RAM3. RAM3 is as shown in the figure.
It has areas shown as ADDRMEM (address memory), AREACNT (area counter), and EEPCTW (EE-PROM count write). It is used as an auxiliary storage means. The same applies to TMPREG (temporary registers) 1 to 5, and TOTLCNT,
DRMCNT, LIFCNT, DRALCNT,
CNTCTW corresponds to data with the same symbol in the EE-PROM 4 described above, and the actual counter operation is performed using this counter area.

Next, the operation of the CPU 1 for reading out the previous count data stored in the EE-PROM 4 to the counter area of the RAM 3 when the power is turned on will be explained with reference to the flowchart shown in FIG.
In addition, Figure 5 shows the initial setting operation of the counter, including the work of searching for the current count value stored in the EE-PROM4 (ST1 to ST3), and the operation of searching the retrieved EE
- It consists of the work of transferring each data in the area of the PROM 4 to the RAM 3 (ST10-ST12), and the work of setting the address of the EE-PROM4 to write the next new data that has been counted up (ST8-ST9).

To explain in detail, first make the initial settings with AREAHK, and set the top address of EE-PROM4 with ST1.
ADDRMEM of RAM3 and register X of CPU1
Then write the value of EE-PROM4 minus 1 from the total number of areas (i.e. 255) to RAM3.
Write to AREACNT. Next, ST2's CNTREAD
The top address of EE-PROM4 is
Read TOTLCNT data (area 1). After this, in ST3, the data of TOTLCNT in the next area 2 is read to the A register of CPU1, and this data and
The ST2 data (TOTLCNT data of area 1) is compared. At this time, area 1
If the TOTLCNT data is large, the data in area 1 is determined to be the current count value, and FOUND (ST
Proceed to 9). On the other hand, if the TOTLCNT data in area 2 is large, the TOTLCNT data in area 2 is compared with the TOTLCNT data in the next area 3. ST2 to ST7 are a loop, comparing the data of areas 2 and 3, and
If the data in areas 3 and 4 are larger, the data in areas 3 and 4 are further compared. In this way, area n and area n+
Comparison of TOTLCNT data in area n
This process is repeated until the TOTLCNT data becomes large, and the current value (maximum value) of the number of print data sheets stored in the EE-PROM 4 is retrieved. Specifically, in ST5, 1 is subtracted from the value of AREACNT, and ST
6, it is determined whether the value of AREACNT is 0, and if the value of AREACNT is not 0, the contents of the address register X are written to ADDRMEM in ST7, and the process returns to ST2. If the AREACNT value becomes 0 as a result of repeating this process, in ST8
ADDRMEM the top address of EE-PROM4
and subtract 1 from the total number of areas.
Write to AREACNT. In this case, the next area to be written is area 1, and the process advances to ST10.

In other words, the TOTLCNT data of areas n and n+1 are compared sequentially, and finally area 255 and the final area 256 are compared and area 256 is
If the TOTLCNT data is larger, the area
The value of 256 is the current value.

On the other hand, if the answer is Y in ST4, proceed to ST9. Here, the contents of ADDRMEM are saved to the STACK of CPU1, and the value of the current address register X is saved.
It performs processing such as writing to ADDRMEM and restoring the contents of STACK to address register X, and prepares the address of the EE-PROM 4 to be written next. If address n is the current value, area n+1 becomes this address. The current value of the number of prints retrieved in this way is ST10
~12, it is transferred to the counter area of RAM3. That is, in ST10, the value of address register
Store PROM4 address) to TMPREG1, 2, store TOTLCNT address of RAM3 to TMPREG
Store in 3 and 4, set the number of bytes to be moved to “8” in the B register, prepare for transfer, and start the next ST.
Proceed to step 11. In ST11, the contents of EE-PROM4 addressed by the contents of TMPREG1 and 2 are
Load register, contents of this A register
Store the contents of TMPREG1, 2 and the address addressed by TMPREG3 and 4 of RAM3.
Add 1 to the contents of TMPREG3 and 4, B
Performs processing to subtract 1 from the contents of the register. After this, in ST12, it is determined whether the B register is 0 or not,
If it is 0, end, if it is not 0, return to ST11,
Repeat until it reaches 0. In this way, EE−
in the current value storage area of PROM4.
TOTLCNT, DRMCNT, LIFCNT,
The data of DRALCNT and CNTCTW are respectively
It is transferred to the counter area with the same symbol in RAM 3, and enters a standby state for counting the number of prints when the electrophotographic copying machine is powered on.

FIG. 6 is a flowchart showing a count-up operation for rewriting data stored in the counter area of the RAM 3 in accordance with a print operation. The operation will be described below with reference to the same figure.

When one print operation is completed, a count request flag Fc is set in the RAM 3 by a control routine (not shown). Thereafter, a data count routine DTCNT shown in FIG. 6 is executed. First, it is checked in ST1 whether the count request flag Fc is set, and if it is set, it is checked in ST1.
Clear the flag Fc to 0 to return it to its original value. Next, in ST3, DRMCNT data in RAM3 is incremented by +1, and in ST4, TOTLCNT
Increment the data by +1 and then in ST5
Check whether DRALCNT data is 0.
As mentioned above, DRALCNT is used to warn when the drum set is due for replacement. For example, if the lifespan of the drum set is 8000 sheets, if the DRMCNT data exceeds 7900 sheets,
DRALCNT starts counting, and when the count reaches 100 sheets, a warning alarm is generated. DRALCNT is initially 0
Therefore, ST5 becomes Y and the process proceeds to ST7. ST
7, the count value of DRMCNT is 7900 as mentioned above.
Check whether the total number of cards has been exceeded, and if not, proceed to ST9. Also, if it exceeds 7900 sheets,
Initial value (alarm flag bit) is set to DRALCNT.
100), so that when ST5 is processed from now on, ST5 becomes N, and ST6 becomes N.
The data of DRALCNT will be incremented by +1. When DRALCNT counts up to 100, the alarm flag bit of DRALCNT is set to 1, and by checking this flag in a separate routine, a warning to replace the drum set can be issued. Also
If the contents of DRALCNT are not 0,
Since DRMCNT has exceeded 7900 counts, by checking DRALCNT, you can predict that the drum set is nearing the end of its life.

In ST9, it is checked whether the TOTLCNT data exceeds a predetermined maintenance period number of sheets (for example, 60,000 counts). If the number exceeds the specified number,
Located in CNTCTW data in RAM3
By setting the MAINTRQ flag (maintenance request flag) and checking this flag, it is possible to display that maintenance inspection is required. Next, in ST11, in CNTCTW
Check whether the flag is set in the CNTMORE flag.

Within CNTCTW, the MAINTRQ flag mentioned above,
When counting large size paper such as B4 size, count 1, 2, 1, 2, and the overall count is 1.
It is equipped with three flags: the CNTMORE flag for counting 1.5 per sheet, and the B4WCTF flag for distinguishing whether the B4 size printing operation is an odd number or an even number. When printing on large size paper such as B4 size, use other B5, A4
The usage range of the photoreceptor will also change compared to when printing on small size paper such as . Since the lifespan of the drum set changes as the usage range of the photoreceptor changes, the count increases according to the size of the paper. Specifically, when printing on B4 size paper, the count is increased by 50% to 1.5 counts, and for other small sizes it is 1 count. In this case, it is possible to count 1.5 for each print operation based on the paper length or paper area ratio, but since the calculation process becomes complicated, the configuration is such that only B4 size is counted by 2 for every other print. Therefore, 1 count and 2 count are repeated alternately like 1, 2, 1, 2, and the total is 1.5 counts per print.
Also, as mentioned above, the B4WCTF flag in CNTCTW is a flag to distinguish between odd and even sheets in the case of B4 print, but this flag changes from 0, 1, 0, 1 for each print. When it is 0, TOTLCNT and DRMCNT are incremented by 1, and when it is 1, they are incremented by 2.
The above-mentioned one count and two counts are performed alternately. Note that this B4WCTF flag changes only when printing on B4 size paper, and does not change when printing on other small size paper.
Irregular counting is performed only when printing.

The irregular count will be explained in detail below with reference to FIG.

In ST11, it is checked whether or not the CNTMORE flag is present, but since the flag is not set in the initial state, ST11 becomes N and the process proceeds to ST13.
Here, it is confirmed whether the paper is B4 size or not based on a paper size signal from a paper size detection device (not shown). If it is not B4 size, ST17
Proceed to ST14 if it is B4 size.
The B4WCTF flag in CNTCTW is alternately inverted to 0, 1, 0, 1 as described above. At this time, if it is 0, ST15 becomes N and the process proceeds to ST17, but if it is 1, ST15 becomes Y and ST1
At step 6, the CNTMORE flag in CNTCTW is set, and the process returns to ST3, where DRMCNT is incremented by +1, and TOTLCNT is incremented by +1 at ST4. As a result, in the case of B4 size, 1
Perform 1, 2, 1, 2 counts for each print, totaling 1.5 counts per print.

After this, proceed to ST11 again through ST5 to ST10, and at this time, proceed to ST16 as mentioned above.
Since the CNTMORE flag was set (executed the irregular count of B4), ST11 becomes Y and ST
Proceed to step 12. Here, clear the CNTMORE flag and proceed to ST17. In ST17, in RAM
Set the value 8 to EEPCTW and EE-PROM4
Indicates a write request to.

The above-mentioned paper size detection device is, for example, one in which a paper cassette is provided with a magnet corresponding to the paper size, and a sensor is provided in the main body of the electrophotographic copying machine to detect the magnetism of the magnet, thereby detecting each paper size. is used.

Figure 7 shows the data of RAM3 mentioned above.
This is a flowchart for writing to PROM4.

The value 8 indicating a write request to the EE-PROM 4 is set in the EEPCTW of the RAM 3 when one print operation is completed as described above. accordingly
Checks the contents of EEPCTW (ST1), and if 8 is written, it is determined that there is a write request, and ST
Proceed to step 2. On the other hand, if it is 0, it is determined that there is no write request. In ST2, due to the performance of EE-PROM4, it is approximately 10 to 10 times per 1 byte data write.
Since it takes 20ms, it is determined whether or not a timer is operating to delay the write operation after writing 1 byte of data. Therefore, when the timer is not operating, the number of prints is written in the EE-PROM 4 in ST3. This write is a 1-byte data write,
Set the value obtained by subtracting 1 from the contents of EEPCTW to the B register, load the contents of ADDRMEM to the X register, add the X register and B register, and set the value to the B register.
- Find the PROM store address and save it to the stack, add the TOTLCNT address in RAM and the value in the B register to find the load side address in RAM, load the data in this address to the A register, and stack the contents of the A register. It is written by writing to the EE-PROM address indicated by the data in the EE-PROM. ST4 and ST5 are for sequentially writing data of each byte as described above.

In ST6, each byte of data is written.
1 is subtracted from the contents of EEPCTW, then ST7
Determine whether the contents of EEPCTW are 0 or not. If it is 0 at this time (ST7 is Y), subtract 1 from the contents of AREACNT (ST8), and then
Determine whether the contents of AREACNT are 0 or not (ST
9). If the contents of AREACNT are not 0 (ST9 is N), the contents of ADDRMEM are rewritten in ST10 to indicate the next write address.
On the other hand, if the contents of AREACNT are 0 (ST9 is Y), it means that it has been written to area 256, so ST
11, enter the top address of the EE-PROM.
Store to ADDRMEM, store the value obtained by subtracting 1 from the total number of areas to AREACNT, and re-enter area 1.
ADDRMEM, AREACNT to write from
Set.

As described above, the counted data is displayed on the display 12 on the operation panel. In addition, in the embodiment, TOTLCNT, DRMCNT, LIFCNT,
Although the five contents of DRALCNT and CNTCTW are shown, when searching the area of EE-PROM4, only TOTLCNT is compared. That is,
Since the other four data are auxiliary data for TOTLCNT, they are managed by representing the TOTLCNT value as the current value. Furthermore, when writing to the EE-PROM 4, the TOTLCNT data is written last, and the TOTLCNT data consists of 3 bytes, and the data is written starting from the least significant byte. This is in case the power is cut off during data writing. For example, if the power is cut off before all 8 bytes of count data are written to the EE-PROM, the next time the power is turned on, the EE-PROM4
The count data stored in the area immediately before the last writing process becomes the current value.
In any case, the error is set to one sheet, and the error is minimized. In this case, as described above, when one print is counted as two, the error is two.

Furthermore, when the EE-PROM is new, it contains the FF value in hexadecimal, but it is necessary to make this state equivalent to the state in which 00 is written. This is done by inverting the bits when reading and writing data.

Further, in order to write print number data to the EE-PROM, a backup battery and a power supply sequence are not required, the configuration can be simplified, and data will not be lost under any circumstances. Furthermore, if the EE-PROM is mounted on a board using a socket etc., if the board breaks down, the board can be replaced and the EE-PROM installed.
All you have to do is replace it with a new board, so the data counted up to that point will not be lost.

Furthermore, when printing on B4 size paper,
Since the count is alternately 1, 2, 1, 2 counts, and the total is 1.5 counts, the life of the drum set can be managed according to the usage range of the photoreceptor. Also,
Since counting is performed using irregular counts with different counts, complicated arithmetic processing and the like are not required, and counting can be performed with a simple configuration.

In addition, the storage area of the EE-PROM is divided into 256 areas, and the area is shifted sequentially each time one print operation is executed, so even though the EE-PROM has a lifespan of the number of writes, the EE-PROM is effectively −
PROM can be used, and even when used in an electrophotographic copying machine, it can be rewritten to a sufficient number of copies over its lifetime.

〔Effect of the invention〕

As explained above, according to the present invention, since a data erasable and programmable storage means is used as a storage means for storing count values, backup batteries and power supply sequences are not required, and the configuration is extremely simple. It can be done. Further, although no backup battery is required, data will not be lost under any circumstances, and data can be reliably protected.

[Brief explanation of drawings]

FIG. 1 is a block diagram of one embodiment of the present invention, and FIG.
The figure is an explanatory diagram showing the address map of the CPU.
Figure 4 is an explanatory diagram showing the EE-PROM address map, Figure 4 is an explanatory diagram showing the RAM address map, Figure 5 is a flowchart showing the operation when the CPU is powered on, and Figure 6 is an explanatory diagram showing the address map of the RAM. A flowchart showing the operation when writing, Figure 7 is EE-
This is a flowchart showing the operation when writing data to PROM. 1...CPU, 2...ROM, 3...RAM, 4
...EE-PROM, 6...Address decoder, 1
2...Indicator.

Claims (1)

[Claims] 1. A non-volatile storage means having a plurality of areas for storing count data, and a read-out means for reading out the current count data from the area where the count data was last written in the non-volatile storage means;
arithmetic processing means for performing arithmetic processing on the current count data in response to a count request; and each time new count data is generated by the processing of the arithmetic processing means, the new count data is stored in the storage means. A counter device comprising: writing means for writing into an area different from the area from which current count data was read.