JP2004078894A - Image forming apparatus, and method and program for rewriting firmware, and record medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To efficiently rewrite firmware in an image forming apparatus with which a main controller and an engine controller having a rewritable memory for storing the firmware are communicably connected to each other and in which the engine controller forms an image corresponding to a signal generated from the main controller in response to the signal. <P>SOLUTION: The main controller transmits a "rewrite mode" command to the engine controller. On the other hand, the engine controller 12 which receives the command transmits a "consent" status. Thus, a printing mode is switched to a rewrite mode. Then, in the rewrite mode, the engine controller 12 functions as a master, the main controller 11 functions as a slave, communication required for rewriting the firmware is performed between both controllers, and the rewrite processing of the firmware is executed. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
According to the present invention, a main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in response to a signal provided from the main controller, the engine controller responds to an image corresponding to the signal. And a method for rewriting firmware stored in the engine controller, a rewriting program, and a recording medium.
[0002]
[Prior art]
2. Description of the Related Art As an image forming apparatus such as a printer, a copying machine, and a facsimile apparatus, for example, an image forming apparatus in which two controllers are communicably connected to each other via a communication interface has been conventionally known (see Patent Document 1). In this image forming apparatus, when an image signal is provided to a main controller from an external device such as a host computer or a built-in scanner, the image signal is analyzed by the main controller, and various image processes are performed. A completed signal (eg, a video signal) is provided to the engine controller. This engine controller has a CPU as a central processing unit and a rewritable nonvolatile memory for storing firmware. When the above signal is received, the engine controller stores the firmware in a nonvolatile memory such as a flash ROM or an EEPROM. An engine corresponding to the image signal is formed on a sheet such as a copy sheet, a transfer sheet, a sheet, and a transparent sheet for OHP by controlling an engine unit based on the firmware.
[0003]
Here, the firmware is stored in a rewritable non-volatile memory for the purpose of flexibly coping with future addition of functions and version upgrade. That is, when it is necessary to add a function or upgrade a version, a new firmware including the added function is newly created, and the old firmware is rewritten and updated with the new firmware.
[0004]
[Patent Document 1]
JP-A-8-161231 (FIG. 2)
[0005]
[Problems to be solved by the invention]
By the way, in the conventional device, in order to perform communication between two controllers, the main controller functions as a master and the engine controller functions as a slave. In other words, the engine controller operates in response to commands and data from the main controller. When an image-processed signal is given from the main controller, the engine controller executes a print mode for forming an image corresponding to the signal based on firmware. I do. On the other hand, when the firmware needs to be rewritten, the apparatus enters a rewrite mode in which the firmware is rewritten in response to a command from the main controller. In this rewrite mode, the engine controller accesses the non-volatile memory to control the firmware rewrite process.
[0006]
However, as described above, since the engine controller is instructed or controlled by the main controller, the firmware rewriting process must always be performed while responding to commands from the main controller. It was not efficient.
[0007]
Further, there is a possibility that a firmware rewrite error occurs during the firmware rewrite operation as described above. For example, in the conventional device, new firmware is written to a nonvolatile memory in the engine controller via the communication interface. In such a device, normal data may not be sent to the engine controller due to a communication error. In addition, an error in writing data to the nonvolatile memory may occur. Then, even if such a rewrite error occurs, if the print mode is executed as it is, the apparatus malfunctions or printing becomes impossible. Therefore, appropriate measures are required to avoid the operation failure caused by such firmware.
[0008]
The present invention has been made in view of the above problems, and a main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and the engine controller responds to a signal given from the main controller. It is a first object of the present invention to efficiently rewrite firmware in an image forming apparatus for forming an image corresponding to the signal.
[0009]
A second object of the present invention is to surely prevent an operation failure caused by firmware in an image forming apparatus capable of executing firmware rewriting processing.
[0010]
[Means for Solving the Problems]
According to the present invention, a main controller and an engine controller having a rewritable (first) memory for storing firmware are communicably connected to each other, and the engine controller responds to the signal in response to a signal provided from the main controller. The present invention relates to an image forming apparatus for forming an image to be reproduced, a method for rewriting firmware in the apparatus, a rewriting program, and a recording medium, and has the following configuration to achieve the first object.
[0011]
The image forming apparatus according to the present invention can switch between a print mode for creating an image corresponding to a signal based on the firmware stored in the first memory and a rewrite mode for rewriting the firmware. Thus, the master / slave relationship between the main controller and the engine controller is switched.
[0012]
In addition, the firmware rewriting method according to the present invention includes the steps of: The master / slave relationship with the engine controller has been swapped.
[0013]
Further, the rewriting program according to the present invention, when the image forming apparatus switches from a printing mode for creating an image corresponding to a signal based on firmware stored in a memory to a rewriting mode for rewriting firmware, It is configured to execute a procedure for exchanging the master / slave relationship between the main controller and the engine controller.
[0014]
Further, a recording medium according to the present invention records the above rewriting program.
[0015]
In the image forming apparatus configured as described above, and the firmware rewriting method, the rewriting program, and the recording medium in the apparatus, the apparatus can be switched between a print mode and a rewrite mode. The master / slave relationship between the main controller and the engine controller is switched. Therefore, in the rewrite mode, the firmware can be rewritten in a state where the main controller and the engine controller are set in a master / slave relationship suitable for the rewrite mode.
[0016]
After execution of the rewrite mode and before the execution of the next print mode, it is detected whether or not a rewrite error has occurred during the execution of the rewrite mode. The rewrite mode may be executed beforehand. As a result, it is possible to prevent printing from being executed as it is despite the occurrence of a rewrite error. As a result, it is possible to reliably avoid malfunctions due to firmware such as a malfunction of the apparatus and printing failure. When a rewriting error is detected, the rewriting mode is executed before the execution of the printing mode, so that the rewriting of the firmware is always completed and the printing operation is executed. Therefore, the printing operation can always be performed with normal firmware.
[0017]
In addition, an initial program loader may be used to detect a rewrite error as described above or to execute the rewrite mode. That is, the apparatus further includes a second memory for storing an initial program loader, and detects whether or not a rewrite error has occurred during execution of the rewrite mode based on the initial program loader when the apparatus is powered on, and performs rewriting. The configuration may be such that when an error is detected, the mode is guided to the rewrite mode.
[0018]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention. FIG. 2 is a block diagram showing an electrical configuration of the image forming apparatus of FIG. This image forming apparatus forms a full-color image by superimposing four color toners of yellow (Y), magenta (M), cyan (C), and black (K), or uses only black (K) toner. To form a monochrome image. In this image forming apparatus, when an image signal is given to the main controller 11 of the control unit 1 from an external device such as the host computer 100, the image signal is analyzed by the main controller 11, and after various image processes are performed, The image-processed signal is supplied to the engine controller 12. The engine controller 12 controls each part of the engine unit EG based on the firmware stored in the flash memory 123, and stores an image corresponding to an image signal on a sheet S such as copy paper, transfer paper, paper, and a transparent sheet for OHP. To form
[0019]
In the engine unit EG, seven units are provided: (a) a photoconductor unit 2; (b) a yellow developing unit (hereinafter referred to as a “Y developing unit”) 3Y; (c) a magenta developing unit (“M developing unit”) 3M; (D) cyan developing unit (“C developing unit”) 3C; (e) black developing unit (“K developing unit”) 3K; (f) intermediate transfer unit 4 and (g) fixing unit 5 It is detachable. In a state where all the units 2, 3Y, 3M, 3C, 3K, 4 and 5 are attached to the apparatus main body 6, as shown in FIG. While rotating in the direction D1, the charging unit 22, the rotary developing unit 3 including the developing units 3Y, 3M, 3C, and 3K and the cleaning unit 23 are arranged around the photosensitive member 21 along the rotation direction D1.
[0020]
Among the seven units 2, 3 Y, 3 M, 3 C, 3 K, 4, and 5, the photoconductor unit 2 houses a photoconductor 21, a charging unit 22, and a cleaning unit 23. In contrast, it is detachable. A charging bias is applied to the charging unit 22 from a charging bias generation unit (not shown), and uniformly charges the outer peripheral surface of the photoconductor 21. The photoconductor unit 2 is provided with a cleaning unit 23 on the upstream side of the charging unit 22 in the rotation direction D1 of the photoconductor 21, and the toner remaining on the outer peripheral surface of the photoconductor 21 after the primary transfer. Scrape off. Thus, the surface cleaning of the photoconductor 21 is performed.
[0021]
The light beam L is emitted from the exposure unit 8 toward the outer peripheral surface of the photoconductor 21 charged by the charging unit 22. The exposure unit 8 is electrically connected to a laser driver (not shown) provided in the engine controller 12, controls the exposure unit 8 according to a drive signal given from the laser driver, and controls the light beam L Exposure is performed on the photoconductor 21 to form an electrostatic latent image corresponding to the image signal on the photoconductor 21.
[0022]
The electrostatic latent image thus formed is developed by the rotary developing unit 3 with toner. In the rotary developing section 3, a developing unit 3K for black, a developing unit 3C for cyan, a developing unit 3M for magenta, and a developing unit 3Y for yellow are provided rotatably about the axis. These developing units 3Y, 3M, 3C, and 3K are moved and positioned at a plurality of predetermined positions, and are selectively positioned at the developing positions with respect to the photoconductor 21. In FIG. 1, the developing unit 3K for black is positioned at the developing position, and in this position, the developing roller 31 provided on the developing unit 3K is arranged to face the photoconductor 21, but the other developing units 3Y, 3M 3C, the developing roller 31 provided in each developing unit is opposed to the photoreceptor 21 by positioning the developing unit at the developing position just like the developing unit 3K.
[0023]
In the developing unit positioned at the developing position, the toner stored in the unit housing is transported to the developing position while being carried by the developing roller 31. Then, by applying a predetermined developing bias to the developing roller 31, the toner in the unit housing selected and positioned at the developing position adheres to the photosensitive member 21 from the developing roller 31 to visualize the electrostatic latent image. I do. Thus, a toner image of the selected color is formed on the surface of the photoconductor 21.
[0024]
The toner image developed by the developing unit 3 as described above is primarily transferred onto the intermediate transfer belt 41 of the intermediate transfer unit 4 in the primary transfer area TR1. That is, the intermediate transfer unit 4 includes an intermediate transfer belt 41 stretched over a plurality of rollers, and a drive unit (not shown) for driving the intermediate transfer belt 41 to rotate. In order to form a color image by superimposing toner images of respective colors formed on the photoconductor 21 on the intermediate transfer belt 41, when a single-color image is to be transferred to the sheet S, the color image is formed on the photoconductor 21. Only the black toner image to be transferred is transferred onto the intermediate transfer belt 41 to form a single color image.
[0025]
Further, in the image forming apparatus according to the present embodiment, the patch sensor PS is disposed so as to face one roller on which the intermediate transfer belt 41 is stretched to detect the density of the patch image.
[0026]
The image thus formed on the intermediate transfer belt 41 is secondarily transferred onto the sheet S taken out of the cassette 9 in a predetermined secondary transfer area TR2. Then, the sheet S on which the toner image has been transferred is introduced into a fixing unit 5 having a built-in heater (not shown), and the toner is fixed on the sheet S by applying pressure while heating. The sheet S on which the image has been formed in this manner is conveyed to a discharge tray section provided on the upper surface of the apparatus main body 6.
[0027]
Next, the electrical configuration of the image forming apparatus of FIG. 1 will be described with reference to FIG. The main controller 11 includes a host interface 111, a CPU 112, a ROM 113, a RAM 114, and an engine interface 115. The main controller 11 is configured to perform communication processing with the host computer 100 via the host interface 111, and receives an image signal transmitted from the host computer 100, a download program and a firmware file described later. Then, the received image signal and the like are temporarily stored in the RAM 114.
[0028]
The CPU 112 is electrically connected to an operation panel 13 attached to the apparatus main body 6 via an input / output port (not shown). The operation panel 13 is provided with a plurality of switches 131 for a user to give various commands to the CPU 112 and a display unit 132 for displaying a message, a printing status, and the like to the user. Thus, the operation panel 13 functions as a man-machine interface.
[0029]
Further, a program for the main controller 11 is stored in the ROM 113 in advance, and various image processes are performed on the received image signal by operating the CPU 112 and a logic circuit (not shown) according to the program. . That is, in the main controller 11 to which the image signal is given from the host computer 100, the RGB data indicating the gradation level of the RGB component of each pixel in the image corresponding to the image signal is converted to the gradation level of the corresponding CMYK component. Is converted to CMYK data indicating. Further, after performing gradation correction on the CMYK data of each pixel, halftoning processing such as an error diffusion method, a dither method, and a screen method is performed to generate halftone CMYK data of, for example, 8 bits per color per pixel. I do. Then, using the halftone CMYK data, a video signal for pulse width modulation of an exposure laser pulse of each of the CMYK color images of the engine unit EG is created, and output to the engine controller 12 via the engine interface 115. Further, commands and data are transmitted to the engine controller 12 based on the above-described program, and mode switching between a print mode and a rewrite mode, which will be described later, is performed. In the rewrite mode, data transmission and standby are performed according to the status from the engine controller 12. And so on.
[0030]
On the other hand, as shown in FIG. 2, the engine controller 12 includes a main interface 121, a CPU 122, a flash memory 123, and a RAM 124. The main interface 121 is for performing communication with the main controller 11, receives commands and data transmitted from the main controller 11, and transmits a “data request”, “data request”, And the status such as "instruction waiting request".
[0031]
Further, in this embodiment, the flash memory 123 is used as a “rewritable (first) memory for storing firmware”. A part of the memory area is write-protected, and an initial The program loader (IPL) is stored, while the firmware is stored in the remaining memory area. Of course, a ROM for storing the initial program loader may be separately provided, and only the firmware may be stored in the flash memory 123.
[0032]
Then, the CPU 122 controls each unit of the engine unit EG by executing the firmware to form an image corresponding to the image signal on a sheet S such as a copy sheet, a transfer sheet, a sheet, and a transparent sheet for OHP (print mode). . In the print mode in which an image corresponding to a video signal from the main controller 11 is created based on the firmware stored in the flash memory 123, the main controller 11 functions as a master and the engine controller 12 functions as a slave. ing.
[0033]
The engine controller 12 can execute a rewrite mode for rewriting firmware in addition to the print mode. That is, the download program is loaded into the RAM 124 based on the initial program loader, and the CPU 122 executes the download program to execute the firmware rewriting process. In this embodiment, the engine controller 12 functions as a master and the main controller 11 functions as a slave during the rewrite mode.
[0034]
Next, the firmware rewriting process will be described in detail with reference to FIGS. FIG. 3 is a diagram showing a communication procedure performed between the main controller and the engine controller, and FIG. 4 is a schematic diagram showing a data transfer state in the engine controller.
[0035]
In the image forming apparatus configured as described above, the main controller 11 transmits a command, data, and the like to the engine controller 12, and the engine controller 12 operating as a slave receiving the command or data is stored in the flash memory 123. The printing process is performed by controlling each part of the engine unit EG based on the firmware (print mode). The memory state at this time is shown in FIG.
[0036]
When the firmware needs to be rewritten, an instruction to switch the image forming apparatus from the print mode to the rewrite mode is given to the main controller 11, and the download program and new firmware are given to the main controller 11. As a specific procedure, for example, a user or a service engineer operates a group of switches 131 provided on the operation panel 13 to instruct the CPU 112 of the main controller 11 to switch the mode to the rewrite mode. Further, a user, a service engineer, or the like sets an external recording medium 101 such as a CD-ROM or a floppy (registered trademark) disk on which a download program and new firmware are recorded, in the host computer 100. When a plurality of host computers 100 are connected to the image forming apparatus via a LAN or the like, an arbitrary host computer 100 can be used. Instead of using an external recording medium, a download program and new firmware stored in a predetermined server may be previously downloaded to a hard disk (not shown) of the host computer 100 via a LAN.
[0037]
Next, the download program and the new firmware are copied from the host computer 100 to the RAM 114 of the main controller 11. Here, the copy operation may be executed using a printer driver installed in the host computer 100. That is, when the printer driver is activated, a button for selecting a firmware rewriting process can be displayed on the display of the host computer 100. Then, when the user or a service engineer selects the button, a processing procedure necessary for the firmware rewriting processing is displayed on the display. Therefore, by operating in accordance therewith, the download program and the new firmware stored in the recording medium (CD-ROM, floppy (registered trademark) disk, hard disk, etc.) are automatically copied to the RAM 114 of the main controller 11. . This results in a user-friendly device.
[0038]
When the copying to the RAM 114 is completed, the main controller 11 transmits a “rewrite mode” command to the engine controller 12 as shown in FIG. On the other hand, the engine controller 12 having received this command transmits an “OK” status to the main controller 11. As a result, the mode is switched from the print mode to the rewrite mode.
[0039]
In this rewrite mode, the engine controller 12 functions as a master and the main controller 11 functions as a slave, and the following communication is performed to execute a firmware rewrite process.
[0040]
(1) Writing the download program 102 (program reading step)
The CPU 122 operates based on the IPL and writes the download program 102 stored in the RAM 114 of the main controller 11 to the RAM 124 of the engine controller 12. Specifically, the engine controller 12 transmits a “data request” status to the main controller 11. Upon receiving this, the main controller 11 returns a byte size indicating the program length status of the download program 102 to the engine controller 12. Then, the engine controller 12 transmits an "instruction waiting request" status to the main controller 11, and upon receiving the instruction, the main controller 11 enters a standby state.
[0041]
Next, in order to request transmission of the download program 102, the engine controller 12 transmits a “data request” status to the main controller 11. The main controller 11 receiving this transmits the download program 102 to the engine controller 12. Then, the engine controller 12 stores the transmitted download program 102 in the RAM 124 (FIG. 4B). Subsequently, the engine controller 12 transmits an "instruction waiting request" status to the main controller 11, and the main controller 11 enters a standby state in response to this.
[0042]
(2) Writing the firmware 103
Next, the download program is started and the firmware 103 is written. First, as shown in FIG. 4C, the old firmware stored in the flash memory 123 is erased (erasing step).
[0043]
Then, in order to request transmission of a header (Header) of the new firmware 103, the engine controller 12 transmits a “data request” status to the main controller 11. The main controller 11 receiving this transmits the header (Header) of the new firmware 103 to the engine controller 12. As shown in FIG. 4D, the header read by the engine controller 12 is temporarily stored in the RAM 124 and then written into the flash memory 123 (writing step; writing procedure). Then, the engine controller 12 transmits an "instruction waiting request" status to the main controller 11, and upon receiving the instruction, the main controller 11 enters a standby state.
[0044]
Further, in order to request the transmission of the firmware, the engine controller 12 transmits a “data request” status to the main controller 11. The main controller 11 receiving this transmits the data of the new firmware 103 to the engine controller 12 in unit length, for example, in units of 128 bytes. The firmware read by the engine controller 12 in this way is, as shown in FIG. 4E, temporarily stored in the RAM 124 and then written into the flash memory 123 (writing step; writing procedure). Then, the engine controller 12 transmits an "instruction waiting request" status to the main controller 11, and upon receiving the instruction, the main controller 11 enters a standby state. The data writing (the process enclosed by the dashed line in FIG. 3) with this unit length byte is repeated N times, and the entire firmware is written into the flash memory 123.
[0045]
Subsequently, the engine controller 12 transmits a “data request” status to the main controller 11 to request transmission of a footer of the firmware 103. The main controller 11 receiving this transmits the footer of the new firmware 103 to the engine controller 12. The footer thus read by the engine controller 12 is temporarily stored in the RAM 124 and then written to the flash memory 123 (writing step; writing procedure), as shown in FIG. When the rewriting of the firmware is completed, the engine controller 12 transmits a "restart request" status to the main controller 11, and in response to this, the main controller 11 executes a restart process to restart the entire apparatus. Then, the firmware rewritten as described above is assumed to be valid.
[0046]
As described above, according to this embodiment, when the firmware rewrite process is required, the mode is switched from the print mode to the rewrite mode, and the master / slave relationship between the main controller 11 and the engine controller 12 is switched. Therefore, the rewrite mode can be executed in an appropriate master / slave state. That is, in the rewriting mode, the engine controller 12 becomes the master and transmits the status to the main controller 11 in accordance with the progress of the rewriting process. Can be given to the main controller 11. As a result, the firmware rewriting process can be performed efficiently.
[0047]
By the way, in the above embodiment, the firmware rewriting process is executed. However, if the rewriting process fails, it is desirable to take appropriate measures. Therefore, in the “other embodiment” described below, the engine controller 12 executes the rewrite mode and determines whether or not a rewrite error (communication error, erase error, and write error) occurs during the rewrite mode. Is determined. Further, when a rewrite error occurs, each unit of the apparatus is controlled so as to prompt a user or a service engineer to re-execute the firmware rewrite process. That is, the image forming apparatus according to another embodiment executes (i) firmware rewriting processing, (ii) rewriting error detection processing during rewriting execution, and (iii) re-execution processing of rewriting mode in this order. . Since the configuration is the same, "other embodiments" will be described in detail below with reference to the drawings, focusing on operations that are different from the previous embodiments.
[0048]
(I) Firmware rewriting process
Since this processing is exactly the same as that of the previous embodiment, the description is omitted.
[0049]
(Ii) Rewriting error detection processing during rewriting
FIG. 5 is a flowchart showing a rewrite error detection process during rewrite execution in the image forming apparatus of FIG. The image forming apparatus executes steps S1 to S4 while the rewrite mode is being executed to determine whether or not a rewrite error has occurred. Specifically, every time data transfer from the main controller 11 to the engine controller 12 is performed, a checksum is transmitted from the main controller 11 to the engine controller 12, and it is confirmed that the data transfer is successfully performed based on the checksum. (Step S1). Further, it is determined whether or not an erasing error of the flash memory 123 has occurred during the rewriting process (step S2). Further, it is determined whether an error has occurred in writing data to the flash memory 123 (step S3).
[0050]
If at least one error occurs before the rewriting process is completed, the process immediately proceeds to step S5, where the engine controller 12 transmits an "interruption request" status to the main controller 11 to interrupt the rewriting process. Further, the main controller 11 displays a message "Turn off the power and turn it on a few minutes later" on the display unit 132, and transmits a similar message from the main controller 11 to the host computer 100 to send the message to the host computer 100. It is displayed on the display of the computer 100 (step S6). In this embodiment, the message is displayed on both the display unit 132 of the image forming apparatus and the display of the host computer 100. However, the message may be displayed on only one of them.
[0051]
As described above, according to this embodiment, it is possible to prevent printing from being executed as it is despite a rewrite error. As a result, it is possible to reliably avoid malfunctions due to firmware such as a malfunction of the apparatus and printing failure. In addition, it is possible to notify the user or the service engineer that a rewrite error has occurred during the rewriting.
[0052]
(Iii) Re-execution processing of rewrite mode
Next, when the user or the service engineer turns on the power supply of the image forming apparatus again according to the message, the re-execution processing of the rewrite mode shown in FIG. 6 is executed. FIG. 6 is a flowchart showing the initial operation when the power is turned on. In this embodiment, when the power is turned on, the initial program loader is activated (step S11), and the CPU 122 executes the initial program to detect whether or not a rewrite error has occurred during execution of the rewrite mode. (Steps S12 and S13). More specifically, the contents stored in the header and footer of the firmware are read in step S12.
[0053]
Then, it is determined whether the firmware is normal based on the stored contents of the header and the footer (step S13). For example, when both the stored contents of the header and the footer are correct values, the firmware is determined to be normal, and the process directly shifts to the print mode. If printing is routinely performed by the image forming apparatus, that is, if the above-described firmware rewriting process is not performed, “YES” is determined in the step S13, and an image signal is transmitted from an external device such as the host computer 100. Then, the printing operation is executed.
[0054]
If at least one of the stored contents of the header and the footer has an abnormal value, the firmware is abnormal, indicating that a rewrite error has occurred during execution of the rewrite mode. For example, when both the stored contents of the header and the footer are abnormal values, the probability that an erasing error has occurred is high. Further, for example, when the storage content of the header is a correct value while the storage content of the footer is an abnormal value, an error (write error) during the writing process shown in FIG. The probability of having done it is high. In any case, if "NO" is determined in the step S13, the process proceeds to a step S14, in which a rewriting mode is induced, and the firmware rewriting process is executed again.
[0055]
FIG. 7 is a diagram showing an operation for guiding to the rewrite mode. When the power is turned on, the above-described steps S11 to S13 are executed, and if "NO" is determined in the step S13, a process of inducing a rewrite mode (step S14) is executed. In this guidance process, a transmission of a “basic status” is made from the main controller 11 to the engine controller 12. The "basic status" is composed of 8-bit data as shown at the top of FIG. 8, and indicates the basic state of the image forming apparatus such as "call" or "pausing" for each bit. Is assigned. On the other hand, upon receiving this request, the engine controller 12 sets “call” in the “basic status” to “1” and sets other bits to “0” in order to execute the guidance process. This “basic status” is transmitted to the main controller 11.
[0056]
Next, the main controller 11 requests the engine controller 12 to transmit “call details” in response to the “call bit” being set to “1”. The "call details" are composed of 8-bit data as shown in the middle part of FIG. 8, and the contents relating to the call such as "paper length error" and "service call" are assigned to each bit. On the other hand, upon receiving this request, the engine controller 12 sets "service call" in "call details" to "1", sets other bits to "0", and then stores the "call details" in the main. Transmit to controller 11.
[0057]
Next, the main controller 11 requests the engine controller 12 to transmit the "service call details" in response to the "service call details" being set to "1". The "service call details" are composed of 8-bit data as shown at the bottom of FIG. 8, and contents relating to the service call such as "download error" and "fan" are assigned to each bit. . On the other hand, the engine controller 12 that has received this request sets “download error” in “service call details” to “1” and sets other bits to “0”, and then sets the “service call details” Is transmitted to the main controller 11.
[0058]
Further, the main controller 11 transmits a “rewrite mode” command to the engine controller 12. On the other hand, the engine controller 12 that has received this command transmits an "OK" status. As a result, the mode is switched from the print mode to the rewrite mode. Thus, the guidance to the rewriting mode is completed, and thereafter, the firmware rewriting process is executed again in the same procedure as in the previous embodiment.
[0059]
As described above, in this embodiment, the header and the footer are provided in the firmware as “error detection information” of the present invention, and the firmware is rewritten including the header and the footer. By verifying the stored contents, it is possible to detect whether or not a firmware rewrite error has occurred. Therefore, it is possible to reliably detect the abnormality of the firmware. Moreover, since the header and the footer are provided as the "error detection information" of the present invention, even if a rewrite error occurs at any stage during the rewrite operation, the occurrence of the rewrite error is detected when the power is turned on again. be able to.
[0060]
When a rewrite error is detected, the rewrite mode is executed again without shifting to the print mode. Therefore, it is possible to prevent the printing from being executed as it is despite the occurrence of the rewriting error. As a result, it is possible to reliably avoid malfunctions due to firmware such as a malfunction of the apparatus and printing failure.
[0061]
When a rewrite error is detected, the rewrite mode is executed prior to the execution of the print mode. That is, the configuration is such that the printing operation is executed after the firmware rewriting is completed. Therefore, the printing operation can always be performed with normal firmware, and high quality printing can be performed.
[0062]
The initial operation is performed based on the program loaded by the initial program loader. The program performs the rewrite error detection (steps S12 and S13) and the process of inducing the rewrite mode (step S14). Is configured. In this embodiment, the status structure is hierarchized, and the engine controller 12 shifts from the main controller 11 to the lower-priority status in order from the higher-priority status, that is, from the higher-level “basic status” in FIG. It is configured to guide to. That is, in this embodiment, as shown in FIG.
(A) 1-bit setting and transmission of “basic status”,
(B) 1-bit setting and transmission of “call details”,
(C) 1-bit setting and transmission of “service call details”,
, The program is guided to the rewrite mode, so that the program can be made compact. In addition, the size of the memory for storing the initial program loader can be reduced.
[0063]
The present invention is not limited to the above-described embodiment, and various changes other than those described above can be made without departing from the gist of the present invention. For example, although the download program 102 is read via the main controller 11, the download program 102 may be stored in a write-protect area of the flash memory 123 of the engine controller 12 in advance, or may be stored in another nonvolatile memory such as a ROM.
[0064]
In the above-described embodiment, the mode switching to the rewriting mode is instructed by operating the switches 131 on the operation panel 13. However, the mode switching is instructed from the host computer 100. The mode switching may be instructed from the printer driver activated in the above.
[0065]
In the above embodiment, the header and the footer are provided in the firmware as “error detection information” of the present invention, but the “error detection information” of the present invention is not limited to this. For example, when a communication error, an erase error, or a write error occurs, a configuration may be adopted in which a rewrite error flag is set in a part of the memory. In this case, the rewrite error flag functions as “error detection information” of the present invention. Then, whether or not a rewrite error has occurred may be detected depending on whether or not the rewrite error flag is set. When the power supply of the device is temporarily turned off when a rewrite error occurs as in the above embodiment, it is desirable to set a rewrite error flag in the nonvolatile memory. Further, a CRC (= Cyclic Redundancy Check) or a checksum may be used as the “error detection information”.
[0066]
In the above embodiment, the firmware and the initial program loader are stored in the same flash memory 123. In other words, the rewritable memory space of the flash memory 123 functions as the “first memory” of the present invention, and the initial program loader (IPL) is placed in the write-protect area of the flash memory 123 in the “second memory” of the present invention. Function. Of course, it goes without saying that the firmware and the initial program loader may be stored in independent memory elements.
[0067]
In the above embodiment, the present invention is applied to an image forming apparatus that forms an image based on an image signal from the host computer 100, that is, a printer, but the present invention is not limited to this. The present invention can be applied to all image forming apparatuses such as a copying machine and a facsimile apparatus which form an image by two controllers communicably connected to each other.
[Brief description of the drawings]
FIG. 1 is a diagram showing an embodiment of an image forming apparatus according to the present invention.
FIG. 2 is a block diagram illustrating an electrical configuration of the image forming apparatus of FIG. 1;
FIG. 3 is a diagram showing a communication procedure performed between a main controller and an engine controller.
FIG. 4 is a schematic diagram showing a data transfer state in an engine controller.
FIG. 5 is a flowchart illustrating a rewrite error detection process performed during rewrite in the image forming apparatus of FIG. 1;
FIG. 6 is a flowchart showing an initial operation at power-on.
FIG. 7 is a diagram illustrating an operation for guiding to a rewrite mode.
FIG. 8 is a diagram illustrating a status structure employed in the image forming apparatus of FIG. 1;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Control unit (control means), 11 ... Main controller, 12 ... Engine controller, 101 ... External recording medium, 102 ... Download program, 103 ... Firmware, 123 ... Flash memory (1st memory, 2nd memory)

Claims (16)

A main controller and an engine controller having a rewritable first memory for storing firmware are communicably connected to each other, and the engine controller forms an image corresponding to the signal in response to a signal provided from the main controller. Image forming apparatus,
A print mode for creating an image corresponding to the signal based on firmware stored in the first memory and a rewrite mode for rewriting the firmware can be switched, and
An image forming apparatus, wherein a master / slave relationship between the main controller and the engine controller is switched according to the mode switching. In the print mode, the main controller and the engine controller are respectively a master and a slave,
2. The image forming apparatus according to claim 1, wherein in the rewriting mode, the main controller and the engine controller are a slave and a master, respectively. A second memory for storing an initial program loader;
At the time of turning on the power of the apparatus, based on the initial program loader, it is determined whether or not a rewrite error has occurred during execution of the rewrite mode, and when the rewrite error is detected, the apparatus is guided to the rewrite mode. Item 3. The image forming apparatus according to Item 1 or 2. The image forming apparatus according to claim 3, wherein the firmware includes at least one piece of error detection information, and detects the rewrite error based on the content of the error detection information. 5. The image forming apparatus according to claim 4, wherein a header and a footer are provided at the beginning and end of the firmware, respectively, as the error detection information. An image in which a main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in response to a signal provided from the main controller, the engine controller forms an image corresponding to the signal; A method of rewriting firmware in a forming apparatus,
A master / slave relationship between the main controller and the engine controller in response to switching from a print mode for creating an image corresponding to the signal based on the firmware stored in the memory to a rewrite mode for rewriting the firmware. A firmware rewriting method characterized by replacing the above. 7. The firmware according to claim 6, wherein, in the rewriting mode, the main controller and the engine controller are set as a slave and a master, respectively, and a new step of reading new firmware from the main controller and writing the new firmware into the memory is performed. Rewriting method. Further comprising a program reading step of reading a download program from the main controller,
8. The firmware rewriting method according to claim 7, wherein in the rewriting mode, the writing step is performed based on the read download program. 8. The firmware rewriting method according to claim 7, wherein in the rewriting mode, an erasing step of erasing the firmware stored in the memory is performed before writing new firmware into the memory. Further comprising a program reading step of reading a download program from the main controller,
10. The firmware rewriting method according to claim 9, wherein in the rewriting mode, the erasing step and the writing step are performed based on the read download program. 11. The firmware rewriting method according to claim 6, wherein when the rewriting of the firmware to the memory is completed, a restarting step of restarting the main controller and the engine controller is executed. After execution of the rewrite mode and before execution of the next print mode, it is detected whether or not a rewrite error has occurred during execution of the rewrite mode. When the rewrite error is detected, execution of the print mode is performed. The firmware rewriting method according to any one of claims 6 to 11, wherein the rewriting mode is executed prior to the updating. An image in which a main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in response to a signal provided from the main controller, the engine controller forms an image corresponding to the signal; Forming equipment,
A master / slave relationship between the main controller and the engine controller in response to switching from a print mode for creating an image corresponding to the signal based on the firmware stored in the memory to a rewrite mode for rewriting the firmware. Rewriting program to execute the procedure to replace the. A main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in a state where the main controller and the engine controller are set as a master and a slave, respectively, a signal is transmitted from the main controller. The image forming apparatus that forms an image corresponding to the signal by giving
A rewriting program for executing a writing procedure of reading new firmware from the main controller and writing the new firmware in the memory with the main controller and the engine controller set as slaves and masters, respectively. An image in which a main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in response to a signal provided from the main controller, the engine controller forms an image corresponding to the signal; Forming equipment,
A master / slave relationship between the main controller and the engine controller in response to switching from a print mode for creating an image corresponding to the signal based on the firmware stored in the memory to a rewrite mode for rewriting the firmware. A computer-readable recording medium on which a rewriting program for executing a procedure for replacing a computer is recorded. A main controller and an engine controller having a rewritable memory for storing firmware are communicably connected to each other, and in a state where the main controller and the engine controller are set as a master and a slave, respectively, a signal is transmitted from the main controller. The image forming apparatus that forms an image corresponding to the signal by giving
With the main controller and the engine controller set as slaves and masters, respectively, a new firmware is read from the main controller, and a computer readable recording of a rewriting program for executing a writing procedure for writing to the memory is performed. recoding media.

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