JP4372089B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copier, a facsimile machine, or a multi-function peripheral that conveys paper and forms an image on the paper, and more particularly to an image forming apparatus that is suitable when a large-capacity memory is installed. .

  In the image forming apparatus, an error check is performed on all bits of the mounted memory, and the system is activated after confirming that the bit is normal.

  On the other hand, with an increase in resolution and color of the formed image and a reduction in the cost of the memory, the capacity of the memory mounted in the apparatus is increasing.

  For this reason, the memory error check time may take several minutes, which causes discomfort to the user.

  On the other hand, advances in memory manufacturing and inspection technologies have improved memory reliability. Many of the causes of errors in the memory error check are deterioration due to heat applied to the memory for a long period of time, and poor terminal contact when the memory is added or removed.

  Therefore, in Patent Document 1 below, the memory error check at the time of system startup is not performed in principle, and only when the total number of sheets processed is greater than or equal to the set value and when the memory storage capacity is different from the previous startup. It is proposed to make a check.

  According to this method, since the memory error check is performed only when the possibility of a memory failure is relatively high, useless memory error check processing is omitted, and the user's discomfort can be eliminated.

However, even if the time from when the image forming apparatus is turned on to when it is turned off is the same, it may vary greatly depending on the user and the date of use. If the set value is exceeded, the memory error check process is performed every time the power is turned on.
JP 2004-178387 A

  In view of such a problem, the present invention, when performing memory error check in consideration of deterioration of memory due to secular change, relatively increases the number of omissions of memory error check by considering the deterioration of memory more appropriately. It is an object of the present invention to provide an image forming apparatus capable of doing so.

In the first aspect of the image forming apparatus according to the present invention,
A processor;
Coupled to the processor, a memory for program and data are stored,
Coupled to the processor, the non-volatile memory means the number of times information is stored which indicates the set number of times the power-on times,
A display device coupled to said processor,
Have
The program for the processor
Update the information indicating the number of power on each time the power is turned on,
When the number information indicates that the number of power-on times has reached the set number due to the update, a memory error check is performed on the memory, and if a memory error is detected, the information is Display on the display device.

  In a second aspect of the image forming apparatus according to the present invention, in the first aspect, the program indicates to the processor that the number information indicates that the number of power-on times has reached the set number due to the update. The number information is changed so that the number of times of power-on until the next memory error check is smaller than the previous time.

In the third aspect of the image forming apparatus according to the present invention, in the first or second aspect,
A watchdog timer coupled to or built into the processor for detecting time-up and interrupting the processor;
The program causes the processor to perform a memory error check on the memory in response to the interrupt, and to display the information on the display device when a memory error is detected.

  In a fourth aspect of the image forming apparatus according to the present invention, in the third aspect, the program causes the processor to change the number-of-times information so that the set number of times decreases in response to the interrupt.

  According to the configuration of the first aspect, the information indicating the number of times of power-on is updated every time the power is turned on, and when the number of times of power-on becomes the set number by the update, the memory error check is performed on the memory. As a result, the memory error check skip count can be made relatively smaller and the memory error check skip count can be made relatively longer than when the memory error check is performed after the number of sheets processed reaches the set number. This makes it possible to reduce the discomfort given to the user.

  According to the configuration of the second aspect, the number of times information is changed so that the number of times of power-on until the next memory error check is reduced from the previous time. Therefore, when the number of times of power-on reaches the set number It is possible to avoid a memory error check every time the power is turned on, and to further reduce discomfort given to the user.

  According to the configuration of the third aspect, since the memory error check is performed on the memory in response to the watchdog timer interrupt, it is possible to further reduce the safety margin and increase the set number of times. It is possible to further reduce discomfort given to the user.

  According to the configuration of the fourth aspect, the set number of times is reduced by the watchdog timer interruption, so that the safety margin can be further reduced and the set number of times can be increased, and the user feels uncomfortable. Can be further reduced.

  Other objects, configurations and effects of the present invention will become apparent from the following description.

  FIG. 1 is a schematic block diagram illustrating a hardware configuration of an image forming apparatus according to Embodiment 1 of the present invention.

  The image forming apparatus 10 is, for example, a multifunction peripheral, and is configured by combining an operation / display unit 12 and an image forming apparatus main body 13 with a control device 11. The control device 11 processes a document image read by the image forming apparatus main body 13 based on information set by the operation / display unit 12 and default setting values, or is supplied from an external host computer 20. Based on the setting information and the image data, the image forming apparatus main body 13 is caused to form an image.

  In the control device 11, a nonvolatile memory 111, an electrically rewritable nonvolatile memory 111A, a volatile memory 112, and interfaces 113 to 115 are coupled to the MPU 110 by a bus, and the interfaces 113 to 115 are connected to the operation / display unit 12, It is coupled to the image forming apparatus main body 13 and the host computer 20. The nonvolatile memory 111 stores data such as programs and initial values of the system. The nonvolatile memory 111A is an EPROM, a flash memory, or the like, and stores a value set by the operation / display unit 12 and a set value N described later.

  The program in the nonvolatile memory 111 does not perform a memory error check when power is turned on. In order to compensate for this, countermeasures are taken when an abnormality such as a program runaway occurs due to a memory failure, which will be described below.

  That is, the watchdog timer 116 is coupled to the MPU 110. The watchdog timer 116 activates the time-up output signal in a relatively long time, for example, 2 seconds. This signal is supplied to the interrupt input terminal IRQ of the MPU 110. If the watchdog timer 116 is not reset before the time-up output signal becomes active, the MPU 110 is interrupted. Watchdog timer 116 restarts when reset. Therefore, a reset signal output command is inserted in the program area of the nonvolatile memory 111 so that the watchdog timer 116 does not time out unless an abnormality such as a program runaway occurs. When this instruction is executed, a reset pulse is supplied to the input terminal RST of the watchdog timer 116, and the watchdog timer 116 is reset.

  FIG. 2 is a flowchart showing processing of a program stored in the non-volatile memory 111. This program is started when the power is turned on. In the following, the step identification codes in the figure are shown in parentheses.

  (S0) If the variable N is not 0, the process proceeds to step S1, and if it is 0, the process proceeds to step S2.

  (S1) The value of the variable N is decremented by 1, and the process proceeds to step S4.

  (S2) The MPU 110 performs a memory error check on the nonvolatile memory 111 and the volatile memory 112. For example, in the nonvolatile memory 111, a hash value of a predetermined area in the nonvolatile memory 111 is calculated and stored in advance, and the MPU 110 calculates a hash value of this area and compares it with the stored value. If they do not match, an error is determined. Here, the hash value is, for example, a hash total, and the predetermined area is the entire area in the nonvolatile memory 111 excluding the hash value storage area, and includes a memory error check program. In addition, for the volatile memory 112, for each of the check patterns stored in the non-volatile memory 111, for example, “01010101” and “10101010”, the check pattern is written in the volatile memory 112, Is read out and it is determined whether or not it matches the written value. If it does not match, it is determined as an error. A plurality of check patterns may be used.

  (S3) If an error is detected, the process proceeds to step S4, and if not, the process proceeds to step S6.

  (S4) The MPU 110 causes the operation / display unit 12 to display information on the presence / absence of a memory error and information indicating the location when an error is detected. In addition, this selection is displayed on the operation / display unit 12 in order to leave the user to select whether to reset and restart the system or to end the process.

  (S5) If restart is selected, the MPU 110 resets itself to restart the system, and if not, ends the processing. In the case of termination, the image forming apparatus 10 may be turned off.

  (S6) The MPU 110 activates an operating system (OS) and a dedicated program that runs on the OS to place the image forming apparatus 10 in a ready state.

  In the processing as described above, the initial value of the variable N is, for example, 500. In this case, the process proceeds from step S0 to step S1 through step S1 until the total number of power-on times reaches 500. Memory error check is not performed.

  If the number of times exceeds 500, the process proceeds from step S0 to step S2, and thereafter, a memory error check is performed every time the power is turned on.

  FIG. 3 is a flowchart showing the processing of the program stored in the non-volatile memory 111. This program interrupts the watchdog timer (WDT) watchdog timer 116 to the MPU 110 when an abnormality such as a program runaway occurs. This is a WDT interrupt process executed by the MPU 110 when it is applied.

  (S10) If the heater of the fixing device, the paper conveyance roller, the motor of the print engine or the scanner, or the light source of the scanner provided in the image forming apparatus main body 13 is on, the MPU 110 turns off the device via the interface 114 This prevents damage to the device and ensures safety.

  (S11) The MPU 110 performs the memory error check as described above.

  (S12, S13) Next, the same processing as steps S4 and S5 in FIG. 2 is performed.

  According to the first embodiment, since a memory error check is not performed at the time of power-on in principle, the system can be started up in a short time even when the volatile memory 112 has a large capacity, and the total power-on After the number of times exceeds the set number, a memory error check is performed each time the power is turned on, and it is possible to prevent a memory error due to memory deterioration due to secular change, causing program runaway or image quality deterioration, etc. Become.

  In addition, the memory error check start time determination is based on the total number of times the power is turned on rather than the number of processed paper sheets, which varies greatly depending on the user and time even when the power on duration is the same. It becomes appropriate, and it becomes possible to further eliminate the user's discomfort by delaying the start time of the memory error check compared with the conventional one.

  Further, when the MPU 110 is interrupted by the watchdog timer 116 due to an abnormality such as a program runaway, a memory error check is performed on the program area and the data area. It is possible to delay the user's discomfort more by delaying.

  In the first embodiment, after the total number of power-on times exceeds the set number of times, a memory error check is performed every time the power is turned on, and the presence or absence of the memory error check changes suddenly. However, since the number of times of setting is set to be small in consideration of the safety margin, it is considered sufficient even if the change in the presence or absence of the memory error check is moderated. In particular, if the memory error check is performed as described above at the time of interrupt by the watchdog timer 116, it is necessary to perform the memory error check every time the power is turned on even if the total number of times of power on exceeds the set number of times. It is thought that there are few.

  Therefore, in the second embodiment of the present invention, every time the variable N becomes 0, the variable N is updated so that the initial value becomes smaller. The initial values of the variable N after the second time are M (0) and M (1). For example, the initial value of the first variable N is 500, the initial value of the second variable N is M (0) = 50, and the initial value of the third variable N is M (1) = 5. repeat. The initial values N, M (0) and M (1) of the first to third variables N, and the variable i relating to the initial value update count are stored in the nonvolatile memory 111A of FIG.

  FIG. 4 is a flowchart showing the processing of the program started when the power is turned on according to the second embodiment of the present invention.

  FIG. 2 is different from FIG. 2 in that steps S7 and S8 are inserted between steps S0 and S2.

  (S7) If i = 3, the process proceeds to step S8, and if not, the process proceeds to step S2. The initial value of i is 0.

  (S8) A new initial value M (i) is substituted for variable N, and i is incremented by one.

  By adding such processing, the presence or absence of memory error check is as shown in FIG.

  Here, when a WDT interrupt occurs during the first variable N times, it is considered preferable to increase the number of executions of the memory error check. In other words, the initial initial value N can be made relatively large by doing in this way.

  FIG. 5 is a flowchart showing WDT interrupt processing in consideration of the above.

  In this interrupt process, the value of the variable N is decreased if N> 0 in step SA between step S11 and step S12. For example, the value of the variable N is decreased by substituting a value [N / 2] rounded to the integer after rounding off the decimal point of N / 2. The other points are the same as the processing of FIG.

  FIG. 6B shows a case where a WDT interruption occurs at N = 300 before the update of the initial value N, and the value of the variable N is reduced to 150.

  According to the second embodiment, the memory error check is performed after the total number of power-on times exceeds the initial value N, the initial value is updated so that the initial value N decreases, and WDT division is performed when N> 0. If an error occurs, the variable N is decreased, and a memory error check is also performed in the WDT interrupt. Therefore, it is possible to reduce the safety margin and to make the initial initial value N relatively large. Increasing the number of check omissions can further eliminate the user's discomfort.

  The present invention includes various modifications in addition to the above.

  For example, since the system reset is performed when the power is turned on, and the number of times the user turns on the system reset switch is generally negligible compared with the number of times the power is turned on, in this specification and the claims, "Means" at power-on or system reset ".

  Further, the memory error check may be performed at the next power-on without performing the memory error check in FIG. 3 or FIG.

  Further, the watchdog timer may be built in the MPU.

  In the above embodiment, the case where the program is stored in the nonvolatile memory 111 has been described. However, the program only needs to be stored in the nonvolatile storage device and is stored in an external storage device such as a hard disk. May be.

1 is a schematic block diagram illustrating a hardware configuration of an image forming apparatus according to Embodiment 1 of the present invention. It is a flowchart which shows the process at the time of power activation. It is a flowchart which shows a watchdog timer interruption process. 7 is a flowchart illustrating processing when power is turned on in an image forming apparatus according to Embodiment 2 of the present invention. It is a flowchart which shows a watchdog timer interruption process. It is a figure which shows the memory error check presence or absence with respect to the frequency | count of power-on.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Control apparatus 110 MPU
111, 111A Nonvolatile memory 112 Volatile memory 113-115 Interface 116 Watchdog timer 12 Operation / display unit 13 Image forming apparatus body 20 Host computer N Variable

Claims (3)

A processor;
Coupled to the processor, a memory for program and data are stored,
Coupled to the processor, the non-volatile memory means the number of times information is stored which indicates the set number of times the power-on times,
A watchdog timer coupled to or incorporated in the processor to detect a time up and interrupt the processor;
A display device coupled to said processor,
Have
The program for the processor
Update the information indicating the number of power on each time the power is turned on,
When the number information indicates that the number of power-on times has reached the set number by the update, or when a memory error is detected in response to the interrupt , and a memory error is detected Displays the information on the display device ,
In response to the interrupt, the number of times information is changed so that the set number of times decreases.
An image forming apparatus.   If the frequency information indicates to the processor that the number of power-on times has reached the set number due to the update, the number of power-on times until the next memory error check is performed. The image forming apparatus according to claim 1, wherein the number-of-times information is changed so as to decrease.   The program causes the processor to perform a memory error check on the memory every time the power is turned on when the number of times information indicates that the number of times the power is turned on has reached the set number of times due to the update. The image forming apparatus according to claim 1.

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