JP4292866B2 - Image forming apparatus, firmware rewriting method, rewriting program, and recording medium - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, 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 supplied from the main controller and the image corresponding to the signal. And a firmware rewriting method, a rewriting program, and a recording medium stored in the engine controller.
[0002]
[Prior art]
2. Description of the Related Art As an image forming apparatus such as a printer, a copying machine, and a facsimile machine, for example, an apparatus in which two controllers are connected so as to communicate with each other via a communication interface has been conventionally known (see Patent Document 1). In this image forming apparatus, when an image signal is given to the 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 subjected to various image processing. A finished signal (for example, a video signal) is supplied 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 is stored in a nonvolatile memory such as a flash ROM or an EEPROM. Based on the firmware, the engine unit is controlled to form an image corresponding to the image signal on a sheet such as copy paper, transfer paper, paper and OHP transparent sheet.
[0003]
Here, the firmware is stored in a rewritable non-volatile memory because the reason is to flexibly cope with future function additions and version upgrades. That is, when it is necessary to add a function or upgrade, a new firmware incorporating the function addition is 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 apparatus, 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, a print mode for forming an image corresponding to the signal is executed based on the firmware. To do. On the other hand, when the firmware needs to be rewritten, it enters a rewriting mode in which the firmware is rewritten in accordance with a command from the main controller. In this rewrite mode, the engine controller accesses the nonvolatile memory to control the firmware rewrite process.
[0006]
However, since the engine controller is instructed or controlled by the main controller as described above, the firmware rewriting process must always be performed in response to a command from the main controller, and the firmware rewriting process is not necessarily performed. It could not be said to be efficient.
[0007]
Further, when performing the firmware rewriting operation as described above, a firmware rewriting error may occur. For example, in the conventional apparatus, new firmware is written into the 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. Even if such a rewriting error occurs, if the printing mode is executed as it is, the apparatus malfunctions or printing becomes impossible. Therefore, appropriate measures are required to avoid such malfunction caused by 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 connected so as to be communicable with each other, and the engine controller according to a signal given from the main controller In the image forming apparatus that forms an image corresponding to the signal, the first object is to efficiently rewrite the firmware.
[0009]
A second object of the present invention is to reliably prevent malfunctions caused by firmware in an image forming apparatus capable of executing firmware rewriting processing.
[0010]
[Means for Solving the Problems]
In the present invention, a main controller and an engine controller having a rewritable (first) memory for storing firmware are connected to be communicable with each other, and the engine controller responds to the signal according to a signal given from the main controller. The present invention relates to an image forming apparatus that forms an image to be printed, a firmware rewriting method, a rewriting program, and a recording medium in the apparatus, and is configured as follows 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, and according to the mode switching. Thus, the master / slave relationship between the main controller and the engine controller is changed.
[0012]
Further, the firmware rewriting method according to the present invention includes a main controller and a controller that are switched 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 the firmware. The master / slave relationship with the engine controller is switched.
[0013]
Further, the rewriting program according to the present invention causes the image forming apparatus to switch 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. A procedure for exchanging the master / slave relationship between the main controller and the engine controller is executed.
[0014]
The recording medium according to the present invention records the above rewriting program.
[0015]
In the image forming apparatus configured as described above, the firmware rewriting method, the rewriting program, and the recording medium in the apparatus, the apparatus can be switched between the printing mode and the rewriting mode, and according to those modes. 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 to a master / slave relationship suitable for the rewrite mode.
[0016]
  Also, whether or not a rewrite error has occurred is determined during the execution of the rewrite mode. If it is determined that a rewrite error has occurred, the rewrite mode is interrupted and the apparatus is turned off and then on again. Prompt the user to.
[0017]
  Also,ILike using a program loaderHave. That is, the second memory for storing the initial program loaderBe equippedIn addition, when the device is turned on, based on the initial program loader, whether or not a rewrite error has occurred when executing the rewrite mode is detected, and when a rewrite error is detected, the device is guided to the rewrite mode.is doing.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a view 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 superposing four color toners of yellow (Y), magenta (M), cyan (C), and black (K), or uses only black (K) toner. This is an apparatus for forming 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 main controller 11 analyzes the image signal and performs various image processing. The image processed signal is supplied to the engine controller 12. The engine controller 12 controls each unit of the engine unit EG based on firmware stored in the flash memory 123, and outputs an image corresponding to an image signal on a sheet S such as copy paper, transfer paper, paper, and an OHP transparent sheet. Form.
[0019]
The engine unit EG includes seven units: (a) a photosensitive unit 2; (b) a yellow developing unit (hereinafter referred to as “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 with respect to apparatus main body 6 It is detachable. Then, with all the units 2, 3Y, 3M, 3C, 3K, 4, 5 mounted on the apparatus main body 6, as shown in FIG. 1, the photoconductor 21 of the photoconductor unit 2 is in the direction of the arrow in FIG. The rotary developing unit 3 and the cleaning unit 23 including the charging unit 22, the developing units 3Y, 3M, 3C, and 3K are disposed 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 photosensitive unit 2 contains a photosensitive member 21, a charging unit 22, and a cleaning unit 23. On the other hand, it is detachable. A charging bias is applied to the charging unit 22 from a charging bias generation unit (not shown), and the outer peripheral surface of the photoreceptor 21 is uniformly charged. Further, the photosensitive unit 2 is provided with a cleaning unit 23 on the upstream side of the charging unit 22 in the rotational direction D1 of the photosensitive unit 21, and the toner remaining on the outer peripheral surface of the photosensitive unit 21 after the primary transfer. Scrap off. In this way, the surface of the photoreceptor 21 is cleaned.
[0021]
The light beam L is irradiated from the exposure unit 8 toward the outer peripheral surface of the photosensitive member 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, and controls the exposure unit 8 in accordance with a drive signal given from the laser driver so that the light beam L is emitted. The photosensitive member 21 is exposed to form an electrostatic latent image corresponding to the image signal on the photosensitive member 21.
[0022]
The electrostatic latent image formed in this way is developed with toner by the rotary developing unit 3. In the rotary developing unit 3, a black developing unit 3K, a cyan developing unit 3C, a magenta developing unit 3M, and a yellow developing unit 3Y are rotatably provided around the axis. The developing units 3Y, 3M, 3C, and 3K are moved and positioned at a plurality of predetermined positions, and are selectively positioned at the developing position with respect to the photoreceptor 21. In FIG. 1, the developing unit 3K for black is positioned at the developing position, and in this positioned state, the developing roller 31 provided in the developing unit 3K is disposed to face the photosensitive member 21, but the other developing units 3Y, 3M are arranged. In 3C, the developing roller 31 provided in each developing unit is disposed opposite to the photosensitive member 21 by positioning the developing unit to the developing position in exactly the same manner as the developing unit 3K.
[0023]
In the developing unit positioned at the developing position, the toner stored in the unit housing is conveyed 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 that is selectively positioned at the developing position adheres to the photosensitive member 21 from the developing roller 31 to visualize the electrostatic latent image. To do. In this way, a toner image of the selected color is formed on the surface of the photoreceptor 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 region TR1. That is, the intermediate transfer unit 4 includes an intermediate transfer belt 41 spanned by a plurality of rollers, and a drive unit (not shown) that rotationally drives the intermediate transfer belt 41, and transfers a color image to the sheet S. In this case, the color toner images formed on the photosensitive member 21 are superimposed on the intermediate transfer belt 41 to form a color image. On the other hand, when a single-color image is transferred to the sheet S, the toner image is formed on the photosensitive member 21. Only the black color toner image is transferred onto the intermediate transfer belt 41 to form a single color image.
[0025]
In the image forming apparatus according to the present embodiment, the patch sensor PS is disposed so as to face the one roller around which the intermediate transfer belt 41 is stretched in order 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 from the cassette 9 in a predetermined secondary transfer region TR2. Then, the sheet S on which the toner image is transferred is introduced into a fixing unit 5 including a heater (not shown), and the toner is fixed to the sheet S by applying pressure while heating. The sheet S on which the image is formed in this way is conveyed to a discharge tray portion provided on the upper surface portion of the apparatus main body 6.
[0027]
Next, the electrical configuration of the image forming apparatus shown in 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 through the host interface 111, and receives an image signal transmitted from the host computer 100, a download program and a firmware file described later. 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 the user to give various commands to the CPU 112, and a display unit 132 for displaying messages, printing status, etc. to the user. The operation panel 13 functions as a man-machine interface.
[0029]
The ROM 113 stores a program for the main controller 11 in advance, and the CPU 112 and a logic circuit (not shown) operate according to the program to perform various image processing on the received image signal. . That is, the main controller 11 to which the image signal is given from the host computer 100 converts the RGB data indicating the gradation level of the RGB component of each pixel in the image corresponding to the image signal into the gradation level of the corresponding CMYK component. Are converted into CMYK data. In addition, after tone correction is performed on CMYK data of each pixel, halftoning processing such as error diffusion, dithering, and screen is further performed to generate, for example, 8-bit halftone CMYK data per pixel. To do. Then, using the halftone CMYK data, a video signal for pulse width modulating the exposure laser pulse of each color image of the engine unit EG is generated and output to the engine controller 12 via the engine interface 115. Further, a command or data is transmitted to the engine controller 12 based on the above program, and mode switching between a print mode and a rewrite mode, which will be described later, and data transmission and standby in accordance with the status from the engine controller 12 in the rewrite mode. Etc. are executed.
[0030]
On the other hand, the engine controller 12 includes a main interface 121, a CPU 122, a flash memory 123, and a RAM 124 as shown in FIG. The main interface 121 is used for communication with the main controller 11, receives commands and data transmitted from the main controller 11, and receives “data request” and “ Sends a status such as “wait for instruction”.
[0031]
Further, in this embodiment, the flash memory 123 is used as “a rewritable (first) memory for storing firmware”, and a part of the memory area is write-protected, and the initial While storing the program loader (IPL), the firmware is stored in the remaining memory area. Of course, a ROM for storing the initial program loader may be provided separately, and only the firmware may be stored in the flash memory 123.
[0032]
The CPU 122 executes the firmware to control each unit of the engine unit EG to form an image corresponding to the image signal on the sheet S such as copy paper, transfer paper, paper, and OHP transparent sheet (print mode). . Thus, in the print mode in which the image corresponding to the 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, particularly 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 commands, data, and the like to the engine controller 12, and the engine controller 12 operating as a slave in response to the command or data is stored in the flash memory 123. Based on the firmware that is being used, each part of the engine unit EG is controlled to perform printing processing (print mode). The memory state at this time is shown in FIG.
[0036]
When the firmware needs to be rewritten, an instruction for switching from the print mode to the rewrite mode is given to the image forming apparatus to the main controller 11, and a 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 switch 131 group provided on the operation panel 13 to instruct the CPU 112 of the main controller 11 to switch to the rewrite mode. 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, any 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 downloaded in advance to a hard disk (not shown) of the host computer 100 via a LAN.
[0037]
Next, the download program and new firmware are copied from the host computer 100 to the RAM 114 of the main controller 11. Here, the copying 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 firmware rewriting processing can be displayed on the display of the host computer 100. When the user or service engineer selects the button, a processing procedure necessary for firmware rewrite processing is displayed on the display. Therefore, the download program and 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 by operating in accordance with the operation. . By doing so, it becomes a user-friendly device.
[0038]
When copying to the RAM 114 is thus 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 that has received this command transmits an “OK” status to the main controller 11. As a result, the print mode is switched 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 firmware rewrite processing.
[0040]
(1) Write download program 102 (program reading process)
The CPU 122 operates based on the IPL, and the download program 102 stored in the RAM 114 of the main controller 11 is written into the RAM 124 of the engine controller 12. Specifically, a “data request” status is transmitted from the engine controller 12 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 a “waiting for instruction” status to the main controller 11, and the main controller 11 enters a standby state in response to this.
[0041]
Next, in order to request transmission of the download program 102, a “data request” status is transmitted from the engine controller 12 to the main controller 11. Receiving this, the main controller 11 transmits a 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 a “waiting for instruction” status to the main controller 11, and the main controller 11 enters a standby state in response to this.
[0042]
(2) Write 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 (erase process).
[0043]
Then, a “data request” status is transmitted from the engine controller 12 to the main controller 11 in order to request transmission of a header of the new firmware 103. Receiving this, the main controller 11 transmits the header of the new firmware 103 to the engine controller 12. The header thus read into the engine controller 12 is once stored in the RAM 124 and then written in the flash memory 123 as shown in FIG. 4 (d) (writing process; writing procedure). Then, the engine controller 12 transmits a “waiting for instruction” status to the main controller 11, and the main controller 11 enters a standby state in response to this.
[0044]
In order to request transmission of firmware, the engine controller 12 transmits a “data request” status to the main controller 11. Receiving this, the main controller 11 transmits the data of the new firmware 103 to the engine controller 12 in unit length, for example, 128 bytes. The firmware read into the engine controller 12 in this way is temporarily stored in the RAM 124 and then written in the flash memory 123 as shown in FIG. 4E (writing process; writing procedure). Then, the engine controller 12 transmits a “waiting for instruction” status to the main controller 11, and the main controller 11 enters a standby state in response to this. The entire firmware is written into the flash memory 123 by repeating the data writing in the unit length byte (processing surrounded by a one-dot chain line in FIG. 3) N times.
[0045]
Subsequently, in order to request transmission of a footer of the firmware 103, a “data request” status is transmitted from the engine controller 12 to the main controller 11. Receiving this, the main controller 11 transmits the footer of the new firmware 103 to the engine controller 12. The footer thus read into the engine controller 12 is temporarily stored in the RAM 124 and then written in the flash memory 123 as shown in FIG. 4 (f) (writing process; writing procedure). Thus, 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 and the entire apparatus is restarted. The firmware rewritten as described above is made valid.
[0046]
As described above, according to this embodiment, when firmware rewrite processing 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 rewrite mode, the engine controller 12 becomes a master and transmits a status to the main controller 11 in accordance with the progress of the rewrite process. Therefore, an appropriate instruction is provided at a timing suitable for each stage of the rewrite process. Can be provided to the main controller 11. As a result, the firmware rewriting process can be performed efficiently.
[0047]
By the way, although the firmware rewriting process is executed in the above embodiment, it is desirable to take an appropriate measure when the rewriting process fails. Therefore, in “another embodiment” to be described next, the engine controller 12 determines whether or not a rewrite error (communication error, erasure error, and write error) occurred during execution of the rewrite mode along with execution of the rewrite mode. Is configured to discriminate. In addition, when a rewrite error occurs, each part of the apparatus is controlled so as to prompt the user or service engineer to re-execute the firmware rewrite process. That is, an image forming apparatus according to another embodiment executes (i) firmware rewriting processing, (ii) rewriting error detection processing during rewriting execution, and (iii) rewriting mode re-execution processing in this order. . Since the configuration is the same, hereinafter, “other embodiments” will be described in detail with reference to the drawings with a focus on operations different from the previous embodiments.
[0048]
(i) Firmware rewrite processing
Since this process is exactly the same as the previous embodiment, the description thereof is omitted.
[0049]
(ii) Rewrite error detection processing during rewrite execution
FIG. 5 is a flowchart showing a rewrite error detection process during rewriting in the image forming apparatus of FIG. This image forming apparatus determines whether or not a rewrite error has occurred by executing steps S1 to S4 while the rewrite mode is being executed. Specifically, every time data is transferred from the main controller 11 to the engine controller 12, a checksum is transmitted from the main controller 11 to the engine controller 12, and it is confirmed that the data transfer has been successfully performed based on the checksum. (Step S1). Further, it is determined whether or not an erase error has occurred in the flash memory 123 during the rewriting process (step S2). Further, it is determined whether or not an error in writing data to the flash memory 123 has occurred (step S3).
[0050]
If even one error occurs until the rewriting process is completed, the process immediately proceeds to step S5, where the engine controller 12 transmits a “suspend request” status to the main controller 11 to interrupt the rewriting process. Further, the main controller 11 displays a message “Please turn off the power and turn it on after a few minutes” on the display unit 132, and send a similar message from the main controller 11 to the host computer 100 to display the host. 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 the printing from being executed as it is even though the rewriting error has occurred. As a result, it is possible to reliably avoid malfunctions caused by firmware such as malfunction of the apparatus and inability to print. In addition, it is possible to notify the user or service engineer that a rewrite error has occurred during rewriting.
[0052]
(iii) Re-execution processing in rewrite mode
Next, when the user or the service engineer turns on the power of the image forming apparatus again in accordance with the message, the re-execution process in the rewrite mode shown in FIG. FIG. 6 is a flowchart showing an 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 firmware header and footer are read in step S12.
[0053]
Then, it is determined whether the firmware is normal based on the stored contents of the header and footer (step S13). For example, if the stored contents of the header and footer are both correct values, it is determined that the firmware is normal, and the process proceeds to the print mode as it is. While printing is routinely performed by the image forming apparatus, that is, when the above-described firmware rewriting process is not performed, “YES” is determined in step S13, and an image signal is received from an external apparatus such as the host computer 100. In response, a printing operation is performed.
[0054]
If at least one of the stored contents of the header and footer is an abnormal value, it is understood that the firmware is abnormal and a rewrite error has occurred during execution of the rewrite mode. For example, if the stored contents of the header and footer are both abnormal values, there is a high probability that an erasure error has occurred. For example, when the stored content of the header is a correct value, but the stored content of the footer is an abnormal value, an error (write error) during the writing process shown in FIG. 4E occurs. Probability is high. In any case, if “NO” is determined in the step S13, the process proceeds to a step S14 so as to be guided to the rewriting mode to execute the firmware rewriting process again.
[0055]
FIG. 7 is a diagram showing the guiding operation to the rewrite mode. When the power is turned on, the above steps S11 to S13 are executed, and if “NO” is determined in the step S13, a guidance process to the rewrite mode (step S14) is executed. In this guidance process, a transmission request for “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 in the uppermost part of FIG. 8, and indicates the basic state of the image forming apparatus such as “call” and “idle” for each bit. Assigned. On the other hand, the engine controller 12 which has received this request sets “1” to the “call bit” in the “basic status” and sets “0” to the other bits 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 send “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 of FIG. 8, and contents related to the call such as “paper short / short error” and “service call” are assigned to each bit. On the other hand, upon receiving this request, the engine controller 12 sets “1” to “service call” in “call details” and sets “0” to other bits, and then sets the “call details” as the main. It transmits to the controller 11.
[0057]
Next, the main controller 11 requests the engine controller 12 to transmit “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 related to service calls 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 “1” to “download error” in “service call details” and sets “0” to other bits, and then “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 print mode is switched to the rewrite mode. In this way, the guidance to the rewrite mode is completed, and then the firmware rewrite process is executed again in the same procedure as in the previous embodiment.
[0059]
As described above, in this embodiment, the header and footer are provided in the firmware as “error detection information” of the present invention, and the firmware is rewritten including the header and 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 firmware abnormality. In addition, since the header and footer are provided as the “error detection information” of the present invention, the occurrence of a rewrite error is detected when the power is turned on again regardless of the stage where the rewrite error occurs during the rewrite operation. be able to.
[0060]
When a rewrite error is detected, the rewrite mode is executed again without shifting to the print mode as it is. Therefore, it is possible to prevent the printing from being executed as it is despite the occurrence of the rewrite error. As a result, it is possible to reliably avoid malfunctions caused by firmware such as malfunction of the apparatus and inability to print.
[0061]
When a rewrite error is detected, the rewrite mode is executed prior to the execution of the print mode. That is, the printing operation is performed after the firmware rewriting is completed. Therefore, the printing operation can always be executed with normal firmware, and printing can be performed with high quality.
[0062]
Further, the initial operation is executed based on the program loaded by the initial program loader, and the rewrite error detection (steps S12 and S13) and the guidance process to the rewrite mode (step S14) are executed by the program. It is configured. In this embodiment, the status structure is hierarchized, and the engine controller 12 is in a rewrite mode while moving from the main controller 11 to a lower priority status, that is, from the upper “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”,
Since the program is guided to the rewrite mode by transmitting, the program can be made compact. This also makes it possible to reduce the memory size for storing the initial program loader.
[0063]
The present invention is not limited to the above-described embodiment, and various modifications other than those described above can be made without departing from the spirit of the present invention. For example, the download program 102 is read via the main controller 11, but may be stored in advance in a write protect area of the flash memory 123 of the engine controller 12 or in a non-volatile memory such as another ROM.
[0064]
In the above embodiment, the mode switch to the rewrite mode is instructed by operating the switch 131 group of the operation panel 13. However, the host computer 100 instructs the mode switch, for example, the host computer 100. The mode switch may be instructed from the printer driver activated in step (b).
[0065]
In the above embodiment, the header and footer are provided in the firmware as “error detection information” of the present invention. However, the “error detection information” of the present invention is not limited to this. For example, a rewrite error flag may be set in a part of the memory when a communication error, an erase error, or a write error occurs. 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 according to whether or not a rewrite error flag is set. Further, when the apparatus power supply 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. Also, CRC (= Cyclic Redundancy Check) or checksum may be used as “error detection information”.
[0066]
In the above embodiment, the firmware and the initial program loader are stored in the same flash memory 123. That is, 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 provided in the write protect area of the flash memory 123 as the “second memory” of the present invention. It is functioning as. Of course, it goes without saying that the firmware and the initial program loader may be stored in mutually 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. However, the application target of the present invention is not limited to this. The present invention can be applied to general image forming apparatuses such as a copying machine and a facsimile machine that perform image formation with two controllers that are 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 showing an electrical configuration of the image forming apparatus of FIG.
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 the engine controller.
5 is a flowchart showing a rewrite error detection process during rewrite execution in the image forming apparatus of FIG. 1. FIG.
FIG. 6 is a flowchart showing an initial operation when power is turned on.
FIG. 7 is a diagram showing a guiding operation to a rewrite mode.
FIG. 8 is a diagram illustrating a status structure employed in the image forming apparatus of FIG.
[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 given from the main controller. In the image forming apparatus to
A second memory for storing an initial program loader;
It is possible to switch between a print mode for creating an image corresponding to the signal based on the firmware stored in the first memory and a rewrite mode for rewriting the firmware,
In accordance with the mode switching, the master / slave relationship between the main controller and the engine controller is switched ,
It is determined whether or not a rewrite error has occurred during execution of the rewrite mode, and when it is determined that the rewrite error has occurred, the rewrite mode is interrupted and the apparatus is turned off and then turned on again. Prompt the user to
Based on the initial program loader, when the device is powered on, it detects whether the rewrite error has occurred during execution of the rewrite mode and guides to the rewrite mode when the rewrite error is detected. An image forming apparatus. The image forming apparatus according to claim 1, wherein the initial program loader hierarchizes a status structure and guides to the rewrite mode while moving from a higher priority status to a lower status . The firmware at least one contains an error detection information, the image forming apparatus according to claim 1 or 2 wherein detecting the rewrite error based on the contents of the error detection information. 4. The image forming apparatus according to claim 3 , wherein a header and a footer are provided at the beginning and the end of the firmware as the error detection information. In the print mode, the main controller and the engine controller are respectively a master and a slave,
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 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 given from the main controller. A method for rewriting firmware in an image forming apparatus including a second memory for storing an initial program loader ,
From a printing mode that form an image corresponding to the signal based on the firmware stored in the first memory, in response to the switching to the rewriting mode for rewriting the firmware, the main controller as the master and the engine controller / Swap slave relationship ,
It is determined whether or not a rewrite error has occurred during execution of the rewrite mode,
When it is determined that the rewrite error has occurred, the rewrite mode is interrupted and the user is prompted to turn the device off and on again,
Based on the initial program loader, when the device is turned on, it detects whether or not the rewrite error has occurred during execution of the rewrite mode, and guides to the rewrite mode when the rewrite error is detected. Firmware rewriting method characterized by the above. 7. The firmware rewriting method according to claim 6, wherein the initial program loader hierarchizes a status structure and guides to the rewriting mode while shifting from a higher priority status to a lower status in order . In the rewrite mode, the set main controller and the engine controller to the slave and master respectively reads the new firmware from the main controller, farm according to claim 6 or 7, wherein executing the writing write process to the memory How to rewrite the wear. A program reading step of reading a download program from the main controller;
9. The firmware rewriting method according to claim 8 , wherein, in the rewriting mode, the writing step is executed based on the read download program. 9. The firmware rewriting method according to claim 8 , wherein in the rewriting mode, an erasing step of erasing the firmware stored in the memory is executed before writing new firmware into the memory. A program reading step of reading a download program from the main controller;
11. The firmware rewriting method according to claim 10 , wherein in the rewriting mode, the erasing step and the writing step are executed based on the read download program. When firmware rewritten into the memory is completed, the main controller and firmware rewriting method according to any one of claims 6 to 11 to perform the restart process to restart the engine controller. 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 given from the main controller. In the image forming apparatus provided with the second memory for storing the initial program loader ,
In response to switching from a print mode in which an image corresponding to the signal is created based on firmware stored in the first memory to a rewrite mode in which the firmware is rewritten, the master / engine controller / master controller The procedure to replace the slave relationship ,
A procedure for determining whether or not a rewrite error has occurred during execution of the rewrite mode;
When it is determined that the rewrite error has occurred, the rewrite mode is interrupted, and a procedure for prompting the user to turn off the apparatus and turn it on again.
When power is supplied to the apparatus, based on the initial program loader, it is detected whether or not the rewrite error has occurred when the rewrite mode is executed, and when the rewrite error is detected, the rewrite mode is guided. A rewrite program to execute procedures and <br/>. 14. The rewrite program according to claim 13, wherein the initial program loader hierarchizes a status structure and guides the rewrite mode while shifting from a higher priority status to a lower status . 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 given from the main controller. In the image forming apparatus provided with the second memory for storing the initial program loader ,
In response to switching from a print mode in which an image corresponding to the signal is created based on firmware stored in the first memory to a rewrite mode in which the firmware is rewritten, the master / engine controller / master controller The procedure to replace the slave relationship ,
A procedure for determining whether or not a rewrite error has occurred during execution of the rewrite mode;
When it is determined that the rewrite error has occurred, the rewrite mode is interrupted, and a procedure for prompting the user to turn off the apparatus and turn it on again.
When power is supplied to the apparatus, based on the initial program loader, it is detected whether or not the rewrite error has occurred when the rewrite mode is executed, and when the rewrite error is detected, the rewrite mode is guided. A computer-readable recording medium on which a rewriting program for executing the procedure and the program is recorded. The computer-readable recording medium according to claim 15, wherein the initial program loader hierarchizes a status structure and guides to the rewrite mode while moving from a higher priority status to a lower status .

Images