JP2866521B2 - Copier memory system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory system for storing variable data such as control parameters and the number of copies in a copying machine.

[0002]

2. Description of the Related Art In a conventional copier, a common SRAM is used as a work area of a CPU and a memory for storing fixed data such as control parameters and variable data such as the number of copies (total number of copies for maintenance). I was using. Since the SRAM stores the control parameters, the number of copies, and the like as described above, the data is backed up by a battery (such as a lithium battery) so that these data are not erased.

[0003]

However, in a battery-backed SRAM, there has been a problem that the contents of the memory may be destroyed due to noise or a decrease in battery capacity. Therefore, a memory element which has excellent noise resistance and does not require a battery for storing memory contents has been desired. As such a memory element, there is a rewritable nonvolatile memory such as an EEPROM. EEPROMs have excellent noise immunity and do not require a battery for memory storage. For this reason, it is suitable for storing data such as control parameters that need hardly be rewritten. However, it has the following problems, and is a storage element for data that needs to be rewritten such as the number of copies. As was not used.

The number of times of writing is limited, and
About ten thousand times. On the other hand, in order to count the number of copies, it is necessary to clear about 300,000 to 3,000,000 copies, and an error occurs if the number of copies is rewritten each time.

The time required for writing is long (about 10 msec) because of the internal pump-up circuit. For this reason, there is a problem in that frequent writing increases the processing time.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a memory system of a copying machine in which a non-volatile memory is used as a storage memory for control parameters, the number of copies, and the like, thereby preventing destruction of memory contents due to noise and a decrease in battery voltage. It is in.

[0007]

According to the present invention, a volatile memory which is used as a count area for variation data such as the number of copies and is backed up by a battery and a rewritable nonvolatile memory for storing the variation data are provided. And a means for writing the fluctuation data of the volatile memory to the nonvolatile memory at predetermined timings.

[0008] The predetermined timing is when the fluctuation data is an integral multiple of a predetermined amount (the predetermined amount is 2 or more).
You. ), Or the first time the volatile capable of holding a power supply to the volatile and non-volatile memory is determined from the load state of the apparatus main body when the power supply OFF to the device body This is when the second time required for writing to the memory and the nonvolatile memory is exceeded.

[0009]

According to the present invention, variable data such as the number of copies is counted using a battery-backed-up volatile memory, and at a predetermined timing, the changed data is written to a nonvolatile memory. For example, change data
Each time it becomes an integral multiple of the predetermined amount (every predetermined amount is added ), it is written to the nonvolatile memory. As a result, the fluctuation data is stored and stored in the nonvolatile memory. In this case, the writing is performed every time the variable data reaches an integral multiple of a predetermined amount. Also, since the predetermined amount is 2 or more, the number of times of writing is reduced. Can be prevented. In addition, the previous Symbol predetermined timing,
When the power supply to the main unit is OFF and the power supply is O
A second time required for writing to the volatile memory and the non-volatile memory is a first time during which the power supply to the volatile memory and the non-volatile memory determined from the load state of the apparatus main body at the time of the FF can be maintained. if when it exceeds the time, it is possible to prevent the occurrence of a write error to the non-volatile memory.

[0010]

FIG. 1 is a block diagram of a copying machine having a memory system according to an embodiment of the present invention. A power supply unit 2, a control board unit 3, a memory board unit 4, an operation board unit 5, a remote communication circuit board unit 6, and the like are provided in the copying machine body 1.

The power supply unit 2 has a DC power supply (+ 38V, +
24V, + 10V, + 5V, etc.) and supplies DC power to the control board unit 3, the memory board unit 4, and the like. The power supply unit 2 has an on / off detection circuit 2
1 is provided. An on / off detection circuit 21 detects an output waveform of the rectifier and detects an on / off state of power supplied from an external power supply to the inside of the copying machine body. Therefore,
The power-off can be detected not only when the main switch MSw is turned off but also when the power supply is cut off due to a power failure, disconnection of an outlet, or the like. Control board unit 3 is CP
A U31, a ROM 32, an I / O, a driver, and the like are provided, connected to each unit through a bus line, and control the operation of each unit. The memory board unit 4 includes an SRAM (volatile memory) 4 backed up by a battery 43.
1, EEPROM (non-volatile memory) 42, battery 4
3 is provided with a voltage detection circuit 44 for detecting the voltage. S
When the main switch MSw is turned on, a power of approximately 5 V is supplied to the RAM 41 via a three-terminal regulator (not shown). When the main switch MSw is turned off, a power of approximately 3 V is supplied from the battery (lithium battery) 43. . The voltage of the battery 43 has the characteristics as shown in FIG. 6 and is consumed over time. The degree of wear is detected by the voltage detection circuit 44. The operation board unit 5 controls an input key and a display unit. The remote communication circuit board unit 6 includes a personal computer and a modem 7 to which an external telephone 8 is connected.
And communicates with the service station through a public telephone line when a trouble occurs. For example, when a trouble such as a voltage drop of the battery 43 occurs, communication with the service station is performed through a public telephone line.

Battery-backed SRAM 41
Is provided with a work area necessary for executing the operation program of the copying machine and a copy number counting area for storing the number of copies. The total number of copies is stored in the copy count area. During copy processing, 1
Each time a copy is made, the number of copies in the copy count area is incremented, and the total number of copies of the copying machine is stored. The copy number count area may store, in addition to the total number of copies, the number of jams during the copy process, the number of copies for each paper size, and the like. The number of copies counted in the SRAM 41 is written to the EEPROM 42 at a predetermined timing. Although this embodiment shows an example in which the variation data is the number of copies, the number of rotations of the photoconductor, the number of jams, and the like may be set as the variation data in addition to the number of copies.

The EEPROM 42 is provided with an area for storing the number of copies and an area for storing control parameters such as control data unique to each copying machine, data set according to the use area, and setting conditions of various modes. Have been.
The control parameters are stored at the factory shipment stage, are hardly changed once set, and are hardly rewritten. On the other hand, the number of copies is written from the SRAM 41 to the EEPROM 42 at a predetermined timing as described above.

The writing timing in this embodiment is for each predetermined number of sheets. This predetermined number is set as follows. The number of times the EEPROM 42 can be written is usually about 10,000 to 100,000 times. On the other hand, it is considered that about 300,000 copies can be made in the case of a 100,000-copy guaranteed copy machine.

Therefore, in this embodiment, 30
Each time the number of copies is added, the number of copies is written to the EEPROM 42 so that it is not necessary to replace the EEPROM 42 during the life of the copying machine. In this embodiment, during multi-copy, E
It is not determined whether or not it is the timing for writing to the EPROM.
It is determined whether or not the number of copies exceeds zero, and if the number of copies exceeds 30, the number of copies (transfer) is written to the EEPROM 42.

FIGS. 2 and 3 are flowcharts according to this embodiment. Each time one copy process is completed, the SRA
The counter of M41 is incremented, and the number of copies is stored (n11 → n12). During multi-copy, only the copying process is repeated, and it is not checked whether it is the writing timing to the EEPROM 42 or not. Then, it is checked whether or not it is time to write data into the EEPROM 42 when the multicopy is completed and the ready state is reached (n13 → n14). If more than 30 copies are added to the counter copy number, the EEPROM 42
Write the contents of the counter to (n1 → n2 → n3 → n
4). Note that R1 is a register. When the writing to the EEPROM 42 is performed in the ready state as described above, since the photoconductor, the copy lamp, and the like are not operating, the load is small and stable writing can be performed.

When the number of copies data is stored in the EEPROM 42 in this manner, while the power of the copying machine is turned off due to battery exhaustion or noise, the SRAM 4
When the number of copies data of 1 is destroyed,
Reads the number of copies data from EPROM 42
AM41 data can be rewritten. FIG. 4 is a flowchart showing the processing procedure. When the power of the copier is turned on, the SR
The copy number data of the AM 41 is compared with the copy number data of the EEPROM 42 (n5 → n6). If the difference between the two copies is equal to or greater than 30 (predetermined number), it is determined that the data has been destroyed due to battery consumption, noise, or the like, and the number of copies stored in the EEPROM 42 is written to the SRAM 41 ( n7). E
Since the EPROM 42 does not require a battery and has excellent noise resistance, the number of copies once written in the EEPROM 42 is hardly destroyed. On the other hand, the number of copies written in the SRAM 41 may be destroyed due to consumption of the battery 43, noise, or the like. Thus, as described above, the number of copies is stored in the EEPROM 42, and if the data in the SRAM 41 has been destroyed, the number of copies in the SRAM 41 can be corrected by transferring the number of copies in the EEPROM 42 to the SRAM 41.

FIGS. 5 and 6 show another embodiment according to the present invention. The voltage of the battery 43 changes over time as shown in FIG. 6, and when the battery voltage drops to about 2.2 V or less, the stored contents of the SRAM 41 are erased or an error occurs. Therefore, in this embodiment, the battery voltage is
When the voltage drops to 2.2 V or less, the number of copies in the SRAM 41 is transferred to the EEPROM 42 to save the data. FIG. 5 is a flowchart showing the processing procedure. The battery check routine is executed while the copier is operating.
This is a routine executed at predetermined timings. In this routine, the battery voltage detected by the voltage detection circuit 44 is checked, and when the battery voltage falls to 2.2 V or less, the number of copies stored in the SRAM 41 is changed to EEPRO.
Transfer to M42 (n21, n24). At this time, by using the flag, the data at the first time when the decrease in the battery voltage is detected is written in the EEPROM 42 (n22 → n23 → n24). By performing such control, it is possible to prevent data corrupted by a decrease in battery voltage from being written to the EEPROM 42. The process the battery voltage is written the number of copies to EEPROM42 when lowered, FIG.
2, a predetermined number of copies shown in FIG.
Used in combination with the process of writing the number of copies.

FIGS. 7 and 8 show another embodiment according to the present invention . The apparatus of this embodiment is shown in FIGS.
Combining the processing shown in the chart and the processing shown below
(Here, the flowchart shown in FIGS. 2 and 3)
The description of the chart is omitted. ). In the power supply unit 2, the secondary output of the transformer is rectified by a diode bridge, processed by a smoothing circuit or the like, and then output to each unit such as a control board unit. The on / off detection circuit 21 in the power supply unit 2 inputs the output of the diode bridge to the CPU.
Fig. 8 shows the output wave of the diode bridge (output waveform of the rectifier).
FIG. 3 is a diagram showing a constant voltage output waveform sent from the power supply unit 2 to each unit. As can be seen, when the main switch MSw is turned on, both the rectifier output waveform and the constant voltage output waveform gradually rise. On the other hand, when the main switch MSw is turned off, the rectifier output waveform becomes almost flat at the same time as being turned off, but the constant voltage output waveform keeps the constant voltage for a while, and then gradually drops. Therefore, if the output of the rectifier is used as the on / off detection signal,
After that, until the constant voltage becomes unstable, the SRA
The contents of M can be transferred to the EEPROM. When the output of the rectifier is used as the on / off detection signal, the power off can be detected even when the power supply to the copying machine main body is stopped due to a power failure, an outlet disconnection, or the like.

In this embodiment, when the power supply to the copying machine main body is turned off by the on / off detection circuit 21, and the battery voltage drop is detected by the voltage detection circuit 44 for detecting the voltage of the battery, SRAM 41
Is transferred to the EEPROM 42. FIG. 7 is a flowchart showing the processing procedure.

When the power-off signal is detected, the data in the work area of the SRAM is saved in the memory area (n31). For example, when the power is turned off during a copy process due to a power outage, an outlet disconnection, or the like, count data of the number of copies involved in the copy process is being processed in the work area, and is saved in the SRAM memory area (n31). ). Then, check the battery voltage, and if the battery voltage is below the specified voltage, the SRAM
41 is transferred to the EEPROM 42 (n32 →
n33). Thereafter, the SRAM 41 enters the standby mode (n34).

In this embodiment, the power supply is turned off and the writing to the EEPROM 42 is performed when the battery voltage of the volatile memory decreases. However, the power supply to the EEPROM 42 is detected only when the power supply off is detected. Writing may be performed, or the EEPROM 4 may be written every predetermined number of sheets shown in the flowcharts of FIGS.
A process of writing the number of copies to 2 is also executed .

FIGS. 9 and 10 show another embodiment according to the present invention . EEPRO data of SRAM41
The operating voltage required to transfer to M42 is 5V. Incidentally, the power of the copying machine may be turned off during the copying operation. In particular, when a power failure, outlet disconnection, or the like occurs, the power supply is suddenly turned off during the copy operation. If the power supply is turned off in the ready state,
For example, as shown in FIG. 10B, 5V power is maintained at 5V for a while (for example, about 180 msec). On the other hand, if the power supply is suddenly turned off during the copy operation, the 5V power supply attenuates in a short time as shown in FIG. 10A (for example, about 30 msec). On the other hand, EE
Since the writing time to the PROM 42 is about 10 msec, writing to the EEPROM 42 can be performed with a sufficient margin in the state of FIG. 10B, but in the state of FIG. During the writing to the memory, a writing error may occur because the power supply voltage of 5 V is not maintained. For this reason,
When the data transfer timing to the EEPROM 42 comes, the processing shown in the flowchart of FIG. 9 is performed. The time during which the 5V voltage is held after the power supply is turned off is obtained and stored in advance according to the load state when the power supply is turned off. The load state in the copying machine main body is substantially constant according to the operation state of the copying machine. The operating state of the copier includes, for example, whether the copier is in a ready state, the stage during the copying process, the power supply to the fixing heater, and the like. The characteristics of the power supply are also known, and the required power in each operation state and the responsiveness of the power supply unit in each operation state are almost constant. Therefore,
It is also required how long the 5 V voltage can be held after the power supply is turned off according to the load state when the power supply is turned off.

When the transfer timing to the EEPROM 42 is reached by adding a predetermined number of copies or turning off the power supply, it is determined whether the voltage required for writing is maintained (n41). If the voltage is held until the end of writing, for example, the state shown in FIG. 10B, data is transferred to the EEPROM 42 and the flag A is set (n42 → n43). Further, a state where the voltage is not held until the end of writing, for example, as shown in FIG.
In the state shown in (A), the data is not transferred to the EEPROM 42, and the flag A is set to "0" (n42 → n).
44). The flag A is for checking whether data has been written to the EEPROM.

FIGS. 11 and 12 show still another embodiment of the present invention .
Is a diagram showing an embodiment. As a large capacity load, for example, there is a fixing heater for heating and fixing a copy image. As shown in FIG. 12, the control circuit of the fixing heater is provided with an output signal RT of the thermistor TH pressed against the heat roller 51.
H level is detected by comparators C1, C2, C3,
The result is input to the CPU 31. CPU3
Numeral 1 outputs an HL signal, the driver IC 52 drives the photocoupler PC1 with a zero-cross circuit, and turns on the triac TO1, thereby turning on the heater lamp HL. To turn on the heater lamp HL, about 1 kW
A large amount of power (about 10 A at 100 V input) flows during lighting. Therefore, if the output impedance of the power outlet is 1Ω, the voltage drop is 1Ω × 10A = 10V..., And the input voltage is reduced by 10%. Although the input voltage range is originally designed with a margin, the output impedance of the power supply cannot be specified from the copier side, so that the voltage drop due to the heating of the heater lamp cannot be predicted.

If a voltage drop occurs due to the lighting of the heater lamp HL, an input voltage drop occurs to the power supply unit 2, and in some cases, a constant voltage may not be supplied to the control unit. In particular, when the heater lamp HL is turned on when the power supply is turned off, the constant voltage (5 V) may not be maintained during the time required for writing to the EEPROM 42 (about 10 msec). Therefore, when it is time to write to the EEPROM, the heater lamp H
L is turned off. The timing of writing to the EEPROM is, for example, when the voltage of the battery 43 of the RAM drops below a predetermined voltage, when the power supply to the copying machine is turned off, or the like. Since the normal copy lamp HL is controlled to be turned on / off, there is no problem even if the power supply to the fixing heater HL is temporarily stopped at the writing timing during the standby of the copy processing.

The processing procedure of this embodiment will be described with reference to the flowchart of FIG. At the data transfer timing, it is determined whether the heat roller HL is on or off (n51). If the heat roller HL is off, the data is transferred to the EEPROM 42 as it is. If the heat roller HL is on, the data is transferred after turning off the heater lamp HL (n51 → n52 → n53). The flag B indicates that the heater lamp HL has been turned off. After the data is transferred to the EEPROM 42, if the flag B is set, the heater lamp HL is turned on and the process returns to the normal processing routine (n54). → n55).

It should be noted that, as in the above embodiment, the EEPROM
When the data transfer to the operation board unit 5 is performed,
May be sent to the display unit to indicate that the battery voltage has dropped, or the service station may be notified via the remote communication circuit board unit 6 to that effect.

[0029]

According to the present invention, the number of times of writing to a nonvolatile memory having a limited number of times of writing can be reduced and the nonvolatile memory can be used as a memory for storing variable data. A problem that an error occurs in the number of copies can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram of a copying machine having a memory system according to the present invention.

FIG. 2 is a flowchart showing a procedure for counting the number of copies according to the embodiment of the present invention;

FIG. 3 is a flowchart showing a data transfer procedure according to the embodiment of the present invention;

FIG. 4 is a flowchart showing a procedure for checking the number of copies.

FIG. 5 is a flowchart showing a data transfer procedure according to another embodiment of the present invention;

FIG. 6 is a diagram showing a change in battery voltage with time.

FIG. 7 is a flowchart showing a data transfer procedure according to another embodiment of the present invention;

FIG. 8 is a diagram showing an example of a rectifier output and a constant voltage output with respect to ON / OFF of power supply.

FIG. 9 is a flowchart showing a data transfer procedure according to another embodiment of the present invention .

FIG. 10 is a diagram showing a constant voltage output state for each operation state of the copying machine;

FIG. 11 is a flowchart showing a data transfer procedure according to another embodiment of the present invention .

FIG. 12 is a diagram illustrating a configuration example of a control circuit of a fixing heater.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-27758 (JP, A) JP-A-3-221197 (JP, A) JP-A-4-15847 (JP, A) JP-A-5-27 53386 (JP, A) JP-A-1-155287 (JP, A) JP-A-1-128257 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) G03G 21/00 370- 540 G03G 21/14

Claims (5)

(57) [Claims] A volatile memory that is used as a count area for variation data such as the number of copies and is backed up by a battery; and a rewritable nonvolatile memory that stores the variation data. Means for writing variation data to the non-volatile memory at predetermined timings, wherein the predetermined timing is such that the variation data is an integer of a predetermined amount .
A memory system for a copying machine , wherein the predetermined amount is an integer of 2 or more . 2. A used as the count area variation data, such as copy sheets, a battery backed-up volatile memory, a nonvolatile memory rewritable for storing the variation data, provided with a, the volatile memory Means for writing the fluctuation data to the non-volatile memory at every predetermined timing, wherein the predetermined timing is determined when the power supply to the device main body is turned off and from the load state of the device main body when the power supply is turned off. A first time during which power supply to the volatile memory and the nonvolatile memory can be maintained is longer than a second time required for writing to the volatile memory and the nonvolatile memory; Memory system. 3. The copying machine according to claim 1, wherein the variation data is the number of copies, and the predetermined amount is equal to or greater than the number obtained by dividing the number of copies that can be made by the copying machine by the number of times of writing in the nonvolatile memory. Memory system. Wherein I and the predetermined timing during the continuous copying process
Write the variation data to the nonvolatile memory
Prohibition, and when the continuous copying process ends,
2. A memory system for a copying machine according to claim 1 , wherein said variable data is written to a memory for generating data . Wherein when it is before Symbol predetermined timing, according to claim 1 including means for turning off the large-capacity load, such as the fixing heater,
5. The memory system of the copying machine according to 3 or 4 .