JP2007136863A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten a system starting time by appropriately omitting a memory error check when a system starts, and to prevent a delay in discovering of a memory error from occurring. <P>SOLUTION: The whole storing region of a volatile memory is equally divided to 16 memory blocks which are isolated from each other into four groups. The four groups are made object regions to be checked when a power supply is turned on. The 16 memory blocks are divided into four groups (i=0-3) in which the memory blocks are prevented from overlapping with each other. The object region of the memory error check is changed so that one of the four groups sequentially shifts every time the power supply is turned on. <P>COPYRIGHT: (C)2007,JPO&INPIT

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 suitable when a large-capacity memory is mounted. .

  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, the memory error occurrence rate differs depending on the date and time of manufacture of the memory, the manufacturer, and the like, and an initial failure may occur due to a cause in manufacturing. If a memory error occurs in the image data area and the image quality deteriorates, it cannot be determined for a long time whether or not the cause is a memory error. There may be no cases.
JP 2004-178387 A

  In view of such problems, the present invention provides an image forming apparatus capable of appropriately omitting a memory error check at the time of system start-up to shorten the system start-up time and prevent a delay in finding a memory error. There is to do.

In the first aspect of the image forming apparatus according to the present invention,
A processor;
Storage means coupled to the processor for storing programs;
Volatile memory coupled to the process;
Non-volatile storage means coupled to the processor for storing memory error check target area information indicating one of the entire storage areas of the volatile memory divided into a plurality of memory blocks;
A display device coupled to the process;
Have
The program for the processor
The memory error check target area information is set so that the memory error check for the area indicated by the memory error check target area information is performed every time the power is turned on, and the memory error check is completed for all the storage areas when the power is turned on multiple times When a memory error is detected, the memory error information is displayed on the display device.

In a second aspect of the image forming apparatus according to the present invention, in the first aspect,
The memory error check target area is a group of m pieces (m <n) separated from each other even though the entire storage area of the volatile memory is equally divided into n memory blocks. The n memory blocks overlap each other. Divided into k groups (k ≧ 2),
The program causes the processor to update the memory error check target area information so that one of the k groups is sequentially shifted every time the power is turned on.

In a third aspect of the image forming apparatus according to the present invention, in the second aspect,
The nonvolatile storage means further stores information indicating the number of times of power-on and its set value,
The program causes the processor to update the information indicating the number of times of power-on each time the power is turned on, and if the number of times of power-on exceeds the set value, a memory error occurs for a plurality of groups of the k groups. The check is performed, and the memory error check target area information is updated so that the plurality of groups shift in order every time the power is turned on.

In a fourth aspect of the image forming apparatus according to the present invention, in any one of the above aspects,
A watchdog timer coupled to or built into the processor for detecting time-up and interrupting the processor;
In response to the interrupt, the program causes the processor to perform a memory error check on the entire storage area of the volatile memory, and if an error is detected, displays the information on the display device.

  According to the configuration of the first aspect, since one of the volatile memory divided into a plurality of memory blocks is subjected to a memory error check when the power is turned on, the memory error check time is shortened and the error is given to the user. Pleasant feeling can be reduced and memory error check is completed for all storage areas of the volatile memory by turning on the power multiple times. Can detect program runaway and image quality degradation at an early stage, giving users peace of mind.

  According to the configuration of the second aspect, even if the volatile memory is composed of a plurality of memory cards and the memory error occurrence rate is different for each memory card, a part of the storage area of each memory card is stored every time the power is turned on. Since the memory error check is performed, the memory error detection rate is generally increased.

  According to the configuration of the third aspect, when the number of power-on times exceeds the set value, a memory error check is performed for a plurality of groups. As the memory error occurrence rate increases, the number of check target areas increases, and it becomes possible to reduce omission of memory error detection.

  According to the configuration of the fourth aspect, even if an error such as a program runaway occurs because the memory error check area at the time of power-on is not the entire area of the volatile memory, the watchdog timer interrupt Since the memory error check is performed for the entire area by the processing, the program runaway and the deterioration of the image quality due to the memory error can be detected at an early stage, which gives the user a sense of security.

  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 check target area identification flag F described later.

  A watchdog timer 116 is coupled to the MPU 110 as a countermeasure when an abnormality such as a program runaway occurs due to a memory failure or the like. 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 check target area identification flag F is “0”, the process proceeds to step S1, and if it is “1”, the process proceeds to step S3.

  (S1) A memory error check is performed on the memory block B0 which is one area when the entire area of the volatile memory 112 is divided into two. FIG. 5A shows a memory block B0 and a memory block B1 divided into two.

  In the memory error check, for each of the check patterns stored in the nonvolatile memory 111, for example, “01010101” and “10101010”, the check pattern is written in the volatile memory 112, and the contents of the volatile memory 112 are read and written. It is determined whether or not the values match, and if they do not match, an error is determined. The number of check patterns used may be 3 or more.

  (S2) The check target area identification flag F is set to “1”, and the process proceeds to step S5.

  (S3) A memory error check is performed on the memory block B1, which is the other area.

  (S4) The check target area identification flag F is set to “0”.

  (S5) If an error is detected, the process proceeds to step S6, and if not, the process proceeds to step S8.

  (S6) The MPU 110 causes the operation / display unit 12 to display information indicating the location of the memory error. In addition, this selection is displayed on the operation / display unit 12 in order to leave the selection to the user to determine whether to reset and restart the system, or to continue or end the processing.

  (S7) If restart is selected, the MPU 110 resets itself and restarts the system. If it continues, the process proceeds to step S8; otherwise, the process ends. In the case of termination, the image forming apparatus 10 may be turned off.

  (S8) The MPU 110 activates the operating system (OS) and a dedicated program that runs on the OS to place the image forming apparatus 10 in a ready state.

  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 a memory error check on all areas of the memories 111, 111A, and 112.

  For example, the hash value of the predetermined area is calculated and stored in advance in the non-volatile memory 111, and the MPU 110 calculates the hash value of this area and compares it with the stored value. If there is, it is determined as an error. 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. For the rewritable nonvolatile memory 111A, the same memory error check as that of the volatile memory 112 is performed.

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

  According to the first embodiment, the entire area of the volatile memory 112 is divided into two, a memory error check is performed on the area indicated by the check target area identification flag F every time the power is turned on, and the check target area identification flag F is inverted. As a result, the memory error check time can be halved to reduce the discomfort given to the user, and if the power is turned on twice, the memory error check is performed for the entire area of the volatile memory 112. As a general rule, program runaway and image quality degradation due to memory errors can be detected earlier than a method that does not perform a memory error check every time the power is turned on, which gives the user a sense of security.

  In addition, even if an abnormality such as a program runaway occurs due to halving the memory error check time, the MPU 110 is interrupted by the watchdog timer 116 and the memory error check is performed on the entire memory area. As a result, program runaway and image quality degradation due to memory errors can be detected earlier, giving the user a sense of security.

  The memory error occurrence rate generally differs depending on the date and time of manufacture of the memory card mounted and the manufacturer. It is unknown to the user which card has a high memory error occurrence rate.

  Therefore, in the second embodiment, as shown in FIG. 5B, for example, the standard mounting memory is divided into two memory blocks B01 and B02, and optional mounting memory is divided into two memory blocks B03 and B04. To divide. Then, at the time of odd-numbered system activation, the memory error check of the memory blocks B01 and B03 is performed, and at the time of even-numbered system activation, the memory error check of the memory blocks B02 and B04 is performed.

  In this way, even if the memory error occurrence rate differs depending on the memory card, the memory error detection rate is generally increased because half of the storage areas of both memory cards are checked for memory error at each activation.

  Here, the storage capacities of the standard mounting memory card and the option mounting memory card are generally different, and the option mounting memory may be composed of a plurality of memory cards.

  Therefore, as shown in FIG. 6, the entire storage area of the volatile memory 112 is equally divided into a large number of blocks, a memory error check is performed for a plurality of blocks at a predetermined block interval, and the block to be checked is shifted each time the power is turned on. .

  In this way, the memory error check is performed for all the memory cards every time, so that the above effects can be obtained regardless of the configuration of the volatile memory 112.

  In FIG. 6, the entire storage area is equally divided into 16 blocks, a variable i having an initial value of 0 is incremented every time the power is turned on, and when i = 4, i = 0 is initialized and the memory block B0i is initialized. , B1i, B2i and B3i are checked for memory errors.

  FIG. 4 shows a flowchart of a program stored in the non-volatile memory 111 that performs such processing after the power is turned on. In this flowchart, steps S20 to S27 are performed instead of steps S0 to S4 in FIG.

  Here, the following variables and constants are used.

Xs: start address of an arbitrary memory block Xe: final address of this memory block A0: start address of volatile memory 112 S: size of storage area (number of words) for memory error check upon power-on
D: Number of memory blocks included in this size Among these variables and constants and check target area identification variable i, A0, S, and D are stored in the nonvolatile memory 111, i is stored in the nonvolatile memory 111A, and Xs And Xe are stored in an area of the volatile memory 112 where no memory error check is performed at that time.

  (S20) The calculation result of A0 + (S / D) * i is substituted for Xs.

  (S21) The calculation result of Xs + S / D-1 is substituted into Xe.

  (S22) A memory error check is performed on the address range Xs to Xe.

  (S23) S is added to Xs.

  (S24) If it is within the range of the mounted memory, the process returns to step S21; otherwise, the process proceeds to step S25.

  (S25) The check target area identification variable i is incremented by one.

  (S26) If i = D, the process proceeds to step S27. Otherwise, the process proceeds to step S5.

  (S27) 0 is substituted into the check target area identification variable i, and the process proceeds to step S5.

  The subsequent processing is the same as the processing after step S5 in FIG.

  By such processing, the memory error check described above with reference to FIG. 6 is performed.

  In the second embodiment, the change in the memory error occurrence rate due to the secular change is not taken into consideration. Therefore, in the third embodiment, in consideration of this, processing as shown in FIG. 7 is performed in response to power-on.

  In the flowchart of FIG. 7, steps S30 to S34 are used instead of steps S20 to S27 of FIG.

  (S30) The power-on count N is incremented by 1. The power-on count N is stored in the non-volatile memory 111A of FIG. 1, and its initial value is zero.

  (S31) If the value N of power-on times is equal to or less than N0, the process proceeds to step S32. If it is in the range of N0 + 1 to N1, the process proceeds to step S32, and if greater than (N1 + 1), the process proceeds to step S34. For example, N0 = 500 and N1 = 600.

  (S32) Steps S20 to S27 of FIG. 4 are performed once, and the process proceeds to step S5.

  (S33) Steps S20 to S27 of FIG. 4 are performed twice, and the process proceeds to step S5.

  (S34) Steps S20 to S27 of FIG. 4 are performed four times, that is, a memory check is performed for all areas of the volatile memory 112, and the process proceeds to step S5.

  According to such processing, when the power-on count N is 500 or less, as shown in FIG. 8A, a memory error check is performed on the area corresponding to the value of the check target area identification variable i every time the power is turned on. And the value of the check target area identification variable i is updated. That is, the memory error check is performed on the entire area of the volatile memory 112 by turning on the power four times.

  When the value of the power-on count N is 501-600, as shown in FIG. 8B, the area corresponding to i = 0 and i = 1, and i = 2 and i = 3 correspond to each time the power is turned on. Memory errors are checked alternately with the selected area.

  When the power-on count N is 601 or more, a memory error check is performed on the entire area of the volatile memory 112 as shown in FIG.

  Therefore, according to the third embodiment, as the memory deteriorates due to the heat applied to the memory for a long time and the memory error occurrence rate increases, the check target area increases, so the memory error check is appropriately omitted. At the same time, omission of memory error detection can be reduced.

  Note that the present invention includes various other modifications.

  For example, since a system reset is generally performed when the power is turned on, in the present specification and claims, “when the power is turned on” means “when the power is turned on or when the system is reset”.

  In the above embodiment, the case where the memory check is not performed for the nonvolatile memories 111 and 111A when the power is turned on has been described. However, the memory error check is performed for the entire area or the divided area similar to the volatile memory 112 every time the power is turned on. The structure which performs this may be sufficient.

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

  Further, a configuration in which a watchdog timer is built in the MPU may be employed.

  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 of the program started by power activation. It is a flowchart which shows a watchdog timer interruption process. It is a flowchart which shows the process of the program started by power activation based on Example 2 of this invention. (A) And (B) is processing explanatory drawing of FIG.2 and FIG.4, respectively. It is processing explanatory drawing of FIG. It is a flowchart which shows the process of the program started by power activation based on Example 3 of this invention. It is processing explanatory drawing of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Control apparatus 110 MPU
111, 111A Non-volatile memory 112 Volatile memory 113-115 Interface 116 Watchdog timer 12 Operation / display unit 13 Image forming apparatus body 20 Host computer F Check target area identification flag i Check target area identification variable N Number of times of power-on B0, B1 , B00 to B03, B10 to B13, B20 to B23, B30 to B33 Memory block

Claims (5)

A processor;
Storage means coupled to the processor for storing programs;
Volatile memory coupled to the process;
Non-volatile storage means coupled to the processor for storing memory error check target area information indicating one of the entire storage areas of the volatile memory divided into a plurality of memory blocks;
A display device coupled to the process;
Have
The program for the processor
The memory error check target area information is set so that the memory error check for the area indicated by the memory error check target area information is performed every time the power is turned on, and the memory error check is completed for all the storage areas when the power is turned on multiple times When a memory error is detected, the memory error information is displayed on the display device.
An image forming apparatus. The memory error check target area information indicates one of the entire storage area of the volatile memory divided into a plurality of memory blocks,
The program causes the processor to update the memory error check target area information so that one of the plurality of memory blocks is sequentially shifted every time the power is turned on.
The image forming apparatus according to claim 1. The memory error check target area is a group of m pieces (m <n) separated from each other even though the entire storage area of the volatile memory is equally divided into n memory blocks. The n memory blocks overlap each other. Divided into k groups (k ≧ 2),
The program causes the processor to update the memory error check target area information so that one of the k groups is sequentially shifted every time the power is turned on.
The image forming apparatus according to claim 1. The nonvolatile storage means further stores information indicating the number of times of power-on and its set value,
The program causes the processor to update the information indicating the number of times of power-on each time the power is turned on, and if the number of times of power-on exceeds the set value, a memory error occurs for a plurality of groups of the k groups. Check the memory error check target area information so that the plurality of groups shift in order every time the power is turned on,
The image forming apparatus according to claim 3. 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 all storage areas of the volatile memory in response to the interrupt, and to display the information on the display device when an error is detected.
The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus.

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