JP2023109510A - Image forming device and method for controlling communication with consumable supply unit - Google Patents

Abstract

To retry operation of forming an image without stopping the operation depending on a situation, when an error occurs in reading and writing to and from a non-volatile memory mounted on a consumable supply unit.SOLUTION: An image forming device comprises: an opening/closing sensor that detects a state of a main body cover that is opened and closed when a consumable supply unit mounted with a non-volatile memory is replaced; a memory communication circuit which reads and writes data concerning use of the consumable supply unit, between the non-volatile memory mounted on the consumable supply unit and the circuit; a memory reset circuit that resets a state concerning the reading and writing to and from the non-volatile memory; and a control part that, when an error occurs during communication of the reading and writing with the non-volatile memory, makes the memory reset circuit reset the state and then retries the communication. The control part resets and retries the communication, for the communication error occurring in a state where the main cover is closed, but does not reset nor retry the communication, for the communication error occurring in a state where the main cover is opened.SELECTED DRAWING: Figure 7

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and communication control between a main body and a consumable unit related to image forming.

Consumable units such as toner cartridges used in image forming apparatuses often include nonvolatile memories such as EEPROMs (Electrically Erasable and Programmable Read Only Memory). In the case of a toner cartridge, it stores information unique to the toner cartridge, such as toner remaining amount data for accurately managing the remaining amount of toner contained therein and the number of sheets printed using the toner cartridge.
A control circuit on the main unit side controls reading and writing, and a serial bus (for example, I ² C BUS (registered trademark) developed by Philips and Motorola) is used to reduce the number of data lines with the consumable unit. SPI (Serial Peripheral Interface, etc.) type proposed by .

However, the remaining toner amount data, the number of prints, and the like change during the printing process of the image forming apparatus or during toner replenishment. That is, data is written to the memory mounted in the consumable unit during operation of the image forming apparatus. During operation of the image forming apparatus, noise is generated from the motors and other components located around the consumable unit, and communication errors may occur during memory reading and writing due to the noise. rice field. In addition, when using memory with high-performance and complicated bus specifications such as the above-mentioned ^I2C BUS and SPI, the original command may be mistakenly recognized as a different command due to the influence of noise. , there was a case where it was not possible to recover normally from a communication error. Conventionally, when such a communication error is detected, the main unit must be turned off and on to hard reset the control circuit on the main unit side. It stopped working as

The following techniques are known for communication (read/write) between the memory mounted in the consumable unit and the main body.
During a print job in which the photoreceptor rotates in the forward rotation direction, communication with an ID chip provided in the process unit of the control section is permitted. Writes/reads data such as travel distance. After the completion of the print job in which the photoreceptor has completely stopped, when the reverse sequence operation for rotating the photoreceptor and the intermediate transfer belt in the reverse direction is started, the control unit prohibits communication with the ID chip (for example, , see Patent Document 1).

Further, when a failure occurs in communication between the cartridge non-contact communication means for storing information necessary for image forming operation and the main body non-contact communication means capable of non-contact communication between the cartridge non-contact communication means and the information. also performs an image forming operation. For this reason, the main body control means is configured to enable the image forming operation by the process cartridge using the previously stored information under predetermined conditions (see, for example, Japanese Laid-Open Patent Publication No. 2002-100001).

JP 2009-175657 A JP-A-2001-194963

If there is a communication error in the reading and writing between the memory installed in the consumable unit and the main unit due to noise, etc., it is desirable to retry the reading and writing that caused the communication error so that the image forming operation does not stop. . However, if the consumable unit is not attached, there is no object of communication in the first place, so the communication does not end normally and an error occurs. It is necessary to distinguish between a case where a communication error occurs despite the presence of a consumable unit and a read/write memory, and a case where a communication error occurs because there is no memory. This is because there is no point in retrying if there is no memory for reading and writing. If a circuit for detecting whether or not the consumable unit is attached is provided, it is possible to distinguish between the two. However, due to cost and space constraints, there are many configurations in which a dedicated circuit for detecting attachment of a consumable unit is not provided.
SUMMARY OF THE INVENTION The present invention has been made in view of the circumstances described above, and is designed to stop the image forming operation according to the situation when an error occurs in the reading and writing of the non-volatile memory mounted in the consumable unit. To provide an image forming apparatus which performs a retry without fail and returns to normal operation.

The present invention provides a mounting portion that detachably supports a consumable unit related to image formation with a non-volatile memory mounted on the main body, and a main body cover that is opened and closed when the mounted consumable unit is replaced. an open/close sensor for detecting; a memory communication circuit for reading/writing data relating to the use of the attached consumable unit to/from a non-volatile memory installed in the consumable unit; a memory reset circuit for resetting; and a control unit for retrying after resetting by the memory reset circuit when an error occurs during read/write communication with the nonvolatile memory, wherein the control unit includes the To provide an image forming apparatus that performs the reset and the retry for a communication error that occurs when a body cover is closed, but does not perform the reset and the retry for a communication error that occurs when the body cover is open.

From a different point of view, the present invention provides a step in which a controller of an image forming apparatus detects an open/closed state of a main body cover that is opened and closed when a detachable consumable unit equipped with a nonvolatile memory is replaced; reading and writing data related to the use of the mounted consumable unit with a non-volatile memory mounted in the consumable unit; and resetting a state related to reading and writing of the nonvolatile memory and then performing a retry, wherein the control unit performs the reset and the retry for a communication error that occurs when the body cover is closed, but the body cover is closed. To provide a communication control method with a consumable unit that does not perform the reset and the retry when a communication error occurs in an open state.

In the image forming apparatus according to the present invention, the control unit resets and retries communication errors that occur when the main body cover is closed, but does not reset and retry communication errors that occur when the main body cover is open. When an error occurs in reading/writing the memory of the product unit, it is possible to retry without stopping the image forming operation depending on the situation to restore normal operation.
The communication control method according to the present invention also has similar effects.

1 is a perspective view showing the appearance of a digital multi-function peripheral that is one embodiment of an image forming apparatus of the present invention; FIG. FIG. 2 is an explanatory diagram showing an internal configuration related to image formation of the multifunction machine of the multifunction machine shown in FIG. 1 ; FIG. 2 is a block diagram showing a configuration related to control of the MFP shown in FIG. 1; FIG. 2 is an explanatory view showing replacement work of a toner cartridge, which is a consumable unit of the MFP shown in FIG. 1; 5 is an explanatory view showing an operation when replacing the toner storage unit shown in FIG. 4; FIG. 4 is an explanatory diagram showing a configuration example of a memory reset circuit shown in FIG. 3; FIG. FIG. 4 is a flow chart showing an example of processing of a unit memory access unit shown in FIG. 3; FIG. FIG. 8 is a flowchart showing details of memory data read processing shown in FIG. 7; FIG. FIG. 8 is a flowchart showing details of memory data write processing shown in FIG. 7; FIG. 4 is a flowchart showing an example of processing of a power saving mode control unit shown in FIG. 3; FIG. 4 is a flowchart showing an example of processing of an eject control unit shown in FIG. 3; FIG.

The present invention will be described in further detail below with reference to the drawings. It should be noted that the following description is illustrative in all respects and should not be construed as limiting the present invention.
(Embodiment 1)
<<Configuration Example of Image Forming Apparatus>>
FIG. 1 is a perspective view showing the appearance of a digital multi-function peripheral which is one embodiment of the image forming apparatus of the present invention. FIG. 2 is an explanatory diagram showing an internal configuration related to image formation of the multifunction machine 100 of the multifunction machine shown in FIG. FIG. 3 is a block diagram showing a configuration related to control of the MFP 100. As shown in FIG.

As shown in FIG. 1, the multifunction machine 100 has an image reading unit 111 for reading a document, an operation unit 105 for receiving user's operation, and a printing unit 115 for forming an image. Furthermore, a paper feed tray 18a is provided below the printing unit 115 . An ejection tray 39a is provided above the printing section 115 and below the image reading section 111, and an ejection tray 39b is provided on the right side. A front door 31, which is a main body cover that can be opened and closed, is provided on the front side. FIG. 1 shows a state in which the front door is open.
A document conveying unit 103 for conveying a document to a reading section is provided on the main body. Underneath the main body is a paper feed desk consisting of three paper feed trays 18b, 18c and 18d for containing print sheets.

Here, the internal configuration related to image formation of the MFP 100 shown in FIG. 2 will be described.
The multifunction machine 100 forms four-color toner images of yellow (Y), magenta (M), cyan (C), and black (BK) by an electrophotographic process, superimposes them on an intermediate transfer belt 21, and prints them on a print sheet. Print color images. Alternatively, a monochrome image using a single color (for example, black) is printed on the print sheet. For this reason, the printing section 115 is internally provided with four process units 30 each including the developing unit 12, the photosensitive drum 13, the charger 14, the drum cleaner 15, and the like. Further, an optical scanning unit 11 for exposing and scanning a photosensitive drum 13 corresponding to each color with a laser beam is arranged.

The multifunction machine 100 has process units 30y, 30m, 30c, and 30k for each color. In FIG. 2, only the components of the process unit 30y for yellow are denoted by reference numerals, and the other colors are omitted. A process unit may also be denoted as process unit 30 using a representative code. Descriptions using representative symbols should be understood to apply to each of the colors Y, M, C, and K.

A toner storage unit 27 corresponding to each color is arranged above the printing unit 115 .
In this embodiment, at least the toner storage units 27 for each color correspond to consumable units. However, for example, the process unit 30 may be configured as a consumable unit separate from the toner containing unit 27 or integrated with the toner containing unit 27 . This is to facilitate replacement of consumables such as the photosensitive drum 13 included in the process unit 30 .

The MFP 100 further includes an image processing circuit 41 that generates an input signal to the optical scanning unit 11 (see FIG. 3). The image processing circuit 41 processes the image data of the document read by the image reading unit 111 to generate exposure data related to the exposure pattern of the photosensitive drum 13 . The exposure data corresponds to the pattern of the electrostatic latent image formed on the surface of the photoreceptor drum 13 .
Under the control of the image formation control unit 133 shown in FIG. , M, C, and K toner images are formed.

A primary transfer roller 16 is arranged at a position in contact with the photosensitive drum 13 of the process unit 30 via the intermediate transfer belt 21 . The image formation control unit 133 applies a voltage to the primary transfer roller 16 to superimpose and transfer the Y, M, C, and K toner images formed on the photosensitive drum 13 onto the intermediate transfer belt 21 . It is sent to a position in contact with the next transfer unit 23 . The image formation control unit 133 drives the secondary transfer unit and applies a voltage to transfer the toner image onto a print sheet fed from the paper feed tray 18a or the like.

The primary transfer roller 16 of each color, the intermediate transfer belt 21 and the belt cleaner may be integrally configured as a detachable primary transfer unit, in which case the primary transfer unit may be configured as a consumable unit. This is because the intermediate transfer belt 21 can be easily replaced. Also, the secondary transfer unit 23 may be configured as a consumable unit that is detachable from the main body. This is because the transfer belt used in the secondary transfer unit 23 can be easily replaced.

Further, the image forming control unit 133 feeds and conveys print sheets from the main body feed tray 18a, the feed trays 18b, 18c, and 18d of the feed desk (not shown in FIG. 2), and the manual feed tray 19. do. As shown in FIG. 1, the manual feed tray 19 can be folded and stored in the main body when not in use.

The image formation control section 133 conveys the print sheet onto which the toner image has been transferred by the secondary transfer unit 23 to the fixing unit 17 . The heat roller 24 and pressure roller 25 of the fixing unit 17 heat and press the print sheet passing therebetween to fix the toner image transferred to the print sheet to the print sheet. The image formation control section 133 drives the fixing unit 17 and controls the heating temperature of the heating roller 24 .
Note that the fixing unit 17 may be configured as a consumable unit detachable from the main body. This is because the heating roller 24 and the pressure roller 25 can be easily replaced.

The image formation control section 133 discharges the print sheet that has passed through the fixing unit 17 to the discharge tray 39a. Alternatively, the sheet is once switched back by the discharge roller 36 to be discharged to the discharge tray 39b on the right side surface. Alternatively, the switchbacked print sheet is guided to the double-sided conveying path 37 and returned to the secondary transfer unit 23 . Then, the toner image is transferred to the back side of the print sheet, and the print sheet is discharged through the fixing unit 17 to the discharge tray 39a or 39b.

As shown in FIG. 3, the control unit 101 includes devices such as a processor 121, a RAM 122, and a main body non-volatile memory 123 as hardware resources. The functions of the control unit 101 are realized by the processor 121 executing a control program pre-stored in the main body non-volatile memory 123 and cooperating with hardware resources. The control section 101 includes a memory communication circuit 125 , a memory reset circuit 127 , an image formation control section 133 and a unit memory access section 135 . It also optionally includes a power saving circuit 129 , a power saving mode controller 137 and an eject controller 139 .

The printing unit 115 has an open/close sensor 33 that detects opening/closing of the front door 31, and the image formation control unit 133 recognizes the detected state. It also optionally includes an ejection mechanism 45 .
FIG. 1 shows a state in which the front door 31 of the MFP 100 is open. As shown in FIG. 1, when the front door 31 is opened, one end of each color toner storage unit 27 and the waste toner collection container 29 are exposed and can be attached and detached. The waste toner collection container 29 is a container that stores waste toner collected by the drum cleaner 15 and the belt cleaner 22 . When the waste toner collecting container 29 is removed, one ends of the developing unit 12 and the process unit 30 behind it are exposed. Furthermore, one end of the primary transfer unit, secondary transfer unit and fixing unit may be exposed. These units may be detachable by the user, or may be detachable by a service engineer.

5A and 5B are explanatory views showing an operation for replacing the toner storage unit shown in FIG. 4. FIG. The printing section 115 is provided with a mounting section 28 having guide rails (not shown in FIG. 5) for guiding the toner storage units 27 of respective colors. A user can attach and detach the toner storage unit 27 by inserting and withdrawing it along the guide rail.

The toner storage unit 27 has a toner unit memory 27m (see FIG. 3). When the toner containing unit 27 is fully mounted along the guide rail of the mounting section 28, the unit memory access section 135 of the control section 101 reads and writes the toner unit memory 27m. As the toner unit memory 27m, for example, an EEPROM (also called a serial EEPROM) having a serial bus interface can be applied.
The memory communication circuit 125 is a circuit for performing communication between the control section 101 of the main body and the toner unit memory 27m. If the toner unit memory 27m is a serial EEPROM, the memory communication circuit 125 is a serial bus interface circuit for accessing the toner unit memory 27m.

The unit memory access section 135 controls access to the toner unit memory 27m using the memory communication circuit 125. FIG. Then, based on the data read out from the toner unit memory 27m, for example, the type of the attached toner storage unit 27 is identified. Further, the unit memory access section 135 writes data relating to the use of the toner containing unit 27 to the toner unit memory 27m for updating. Examples of data related to usage include the remaining amount of toner stored in the toner storage unit 27, the number of prints executed using the corresponding color when the toner storage unit 27 is installed, the period after installation, and the like. data related to the usage history of

The memory reset circuit 127 is a circuit that resets the toner unit memory 27m based on instructions from the unit memory access section 135. FIG. The data stored in the toner unit memory 27m, which is a non-volatile memory, is not erased by resetting. When the toner unit memory 27m is a serial EEPROM, if it is reset in the middle of the read/write process, the read/write process is interrupted and the state before the read/write is started is restored.
FIG. 6 is an explanatory diagram showing a configuration example of the memory reset circuit shown in FIG. The toner unit memory 27m shown in FIG. 6 is an I ² C BUS type serial EEPROM. The memory reset circuit 127 shown in FIG. 6 is a circuit that turns on and off the power of the communication line with the toner unit memory 27m mounted in the toner containing unit 27 without affecting the power supply to other circuits. be.
The toner unit memory 27m is provided for each toner storage unit 27 of each color, and the memory reset circuit 127 shown in FIG. 6 is a common circuit for all the toner unit memories 27m in order to reduce the number of parts. In other words, it is provided so that it can be turned on/off collectively with respect to the power supply Vcc common to all the toner unit memories 27m. By doing so, the reset works even for the toner unit memory 27m in which no communication error has occurred.
Also, a memory reset circuit 127 may be provided so that each toner unit memory 27m can be individually reset. Alternatively, two systems of memory reset circuits 127 may be provided, one for black only and one for all other color toner unit memories 27m.

Unlike the reading and writing of the main body non-volatile memory 123 included in the control unit 101, the toner unit memory 27m is physically separated from the control unit 101, and the signal line for reading and writing is connected to the motor which becomes a noise source inside the multifunction machine 100. etc. Moreover, since the reading and writing of the toner unit memory 27m are performed mainly during the processing of print jobs that use toner, they are susceptible to noise. When an error occurs during data read/write processing due to noise, resetting the toner unit memory 27m to return the read/write processing to the initial state and then retrying is effective for the error caused by the noise. It is a good measure.

When the image forming apparatus is not used for a predetermined period of time (for example, 5 minutes), the power saving mode control unit 137 cuts off the power supply to each part of the apparatus except for some parts to reduce the power consumption in the standby state. control to suppress When the user's approach is detected, an operation on the operation unit 105 is detected, or a document is set on the document transport unit 103, power supply is started (restarted) and the power saving mode is exited. Shift to a normal mode in which image formation can be performed.

The eject control unit 139 is arbitrarily provided in the MFP 100 as a pair with the eject mechanism 45 . When the toner storage unit 27 is attached to the attachment portion 28 , the ejection mechanism 45 is in a mechanically locked state (locked state) so that the attached toner storage unit 27 cannot be removed without an instruction from the ejection control unit 139 . to The ejection control unit 139 releases the locked state when, for example, the toner stored in the toner storage unit 27 runs out. Another example is when a predetermined operation is performed on a predetermined screen prepared for maintenance using the operation unit 105 .

For example, when the eject control unit 139 determines that the toner stored in the attached toner storage unit 27 is no longer used, it operates the eject mechanism 45 to release the locked state (unlock state) and A display prompting the user to replace the unit 27 is displayed on the operation unit 105 . In the unlocked state, the toner unit memory 27m is physically disconnected from the main body and cannot be read or written.
The eject mechanism 45 is a mechanism for mechanically locking and unlocking the toner storage unit 27 attached to the attachment portion 28 . The eject mechanism 45 includes a mounting sensor for detecting the mounted toner containing unit 27 and a motor for locking the mounted toner containing unit 27 .

≪Flowchart≫
Processing related to reading and writing from the toner unit memory 27m executed by the control unit 101, particularly processing when an error occurs during reading and writing will be described.
7 to 11 are flow charts showing an example of processing executed by the controller 101 regarding access to the toner unit memory 27m in this embodiment. The flowchart in FIG. 7 shows processing executed by the processor 121 as the unit memory access section 135 . The flowchart of FIG. 8 shows the details of the memory data read processing shown in FIG. The flowchart in FIG. 9 shows details of the memory data write process shown in FIG. The flowchart in FIG. 10 shows an example of processing executed by the power saving mode control unit 137 . The flowchart in FIG. 11 shows an example of processing executed by the ejection control unit 139 .

As shown in FIG. 7, the processor 121 as the unit memory access unit 135 executes the following unit memory access processing under a multitasking environment in parallel with other processing tasks of the image forming apparatus.
After the power switch is turned on or when returning from the power saving mode, the processor 121 first refers to the open/close sensor 33 to confirm whether or not the front door 31, which is the body cover, is closed (closed state) (step S11). ). If the front door 31 is in an open state (open state) (No in step S11), a message warning that the front door is open is displayed on the operation unit 105 to call the user's attention (step S13).

If the body cover is closed or has been closed from the beginning (Yes in step S11), the processor 121 erases the message in step S13 if it is displayed. Then, a process of reading memory data stored in the toner unit memory 27m (memory data read process) is executed (step S15). Details of the memory data reading process will be described later.
If a communication error occurs during memory data read processing and the communication error is not resolved even after retrying, the processor 121 sets an error processing request flag in the memory data read processing. After executing the memory data read process, the processor 121 determines whether or not the error process request flag is set (step S17).

If the error processing request flag is set (Yes in step S17), the processor 121 causes the operation unit 105 to display a message warning that the toner containing unit 27 is not installed to call the user's attention (step S19). If the memory data reading process fails immediately after the power is turned on or immediately after the front door 31 is closed, there is a possibility that the toner containing unit 27 is not installed. It is determined that the device is not attached, and the user is prompted to take action.

If the error processing request flag is not set in the determination of step S17 described above (determination of No), the processor 121 determines whether a request to execute the print job has been received (step S21). That is, the state leading to this determination is a state in which the front door 31 is closed, the toner storage unit 27 is attached, and the printer is waiting for execution of a print job.
If there is no print job execution request (No in step S21), that is, if the printer is in a standby state waiting for job execution, the processor 121 advances the process to step S37 and confirms whether or not the power has been turned off. If the power is turned off (Yes in step S37), the process ends. If the power has not been turned off, the processor 121 loops the process back to the above-described step S21 and waits while looping until a print job execution request is received.

Upon receiving the print job execution request (Yes in step S21), the processor 121 executes the requested print job (step S23). Subsequently, the processor 121 determines whether data to be written in the toner unit memory 27m has been generated by executing the print job and using the toner (step S25).
If the data to be written has not been created (No in step S25), the processor 121 advances the process to step S37 and waits until a next print job request is received while looping again.
On the other hand, if it is determined in step S25 that there is data to be written (Yes in step S25), the processor 121 executes the process of writing the data into the toner unit memory 27m (memory data write process) (step S27).
After the memory data write process, the processor 121 determines whether an error has occurred in the write process. To determine whether or not an error has occurred, the processor 121 first refers to the open/close sensor 33 to determine whether or not the front door 31 is closed (step S29).

If the front door 31 is open (No in step S29), the process proceeds to step S13, and a warning message is displayed on the operation unit 105 to warn that the front door 31 is open. evoke If the multifunction machine 100 is a high-speed machine that can handle a large amount of printing, it may be configured to replace the toner containing unit 27 without stopping printing. If the multifunction machine 100 is configured in such a manner, the front door 31 may be opened and the toner storage unit 27 may be removed even during processing of a print job. As a result, the toner unit memory 27m cannot be read or written, and a communication error occurs. It is not preferable to stop the print job and shift to an error state. Therefore, in this embodiment, when the front door 31 is opened during processing of a print job, a message prompting the user to close the front door 31 is displayed without opening the error state even if a communication error occurs. keep in In this way, even if a circuit for detecting whether or not the toner containing unit 27 is attached is not provided, the toner containing unit 27 can be replaced without stopping the print job.

When the front door 31 is in an open state, there is a possibility that the toner containing unit 27 is not mounted, so the toner containing unit 27 is judged to be unmounted without shifting to an error state, and the user's response is urged.
If it is determined in step S29 that the front door 31 is open (Yes in step S29), the processor 121 determines whether the error processing request flag is set (step S31). If the error processing request flag is not set (No in step S17), the processor 121 advances the process to step S37 and waits until the next print job request is received while looping again.
If the error processing request flag is set (Yes in step S17), the processor 121 causes the operation unit 105 to display a message notifying that a communication error has occurred during writing to the toner unit memory 27m, and restarts the MFP 100. Transition to an error state and stop the operation (step S35).
The above is an example of processing executed by the processor 121 as the unit memory access unit 135 .

Next, the details of the memory data reading process will be described. 9 is a flowchart shown in FIG. 8; In the memory data reading process, the processor 121 first sets a predetermined upper limit number of retries to a variable of a retry counter that counts the number of retries executed when an error occurs (step S41). In one example, the value of the upper limit number of retries is 3. Subsequently, the processor 121 reads data to be read from the toner unit memory 27m (step S45). Then, it is determined whether or not a communication error has occurred during data reading (step S47).

If no error occurs during data reading (No in step S47), processor 121 terminates the memory data reading process. On the other hand, if an error occurs during data reading, processor 121 attempts a retry. The retry procedure is as follows. First, the processor 121 refers to the retry counter and determines whether or not the value is greater than zero (step S51). If the value of the retry counter is greater than zero (Yes in step S51), the value of the retry counter is decremented by -1 (step S57).

Subsequently, the memory reset circuit 127 is activated to once cut off the power supply VCC to the toner unit memory 27m, and then the VCC is supplied again (step S59). Then, the processing is returned to the above-described step S45. In step S45, the data to be read is read again from the toner unit memory 27m. If the retry data reading succeeds and no error occurs (No in step S47), the memory data reading process is terminated.
On the other hand, if an error occurs again during the retry data reading (Yes in step S47), the retry counter is decremented by -1 as long as the value of the retry counter is equal to or greater than zero, and the retry is repeated. If an error occurs every time the retry is repeated until the value of the retry counter becomes zero (No in step S51), the processor 121 sets the error processing request flag and shifts the MFP 100 to the error state. (step S53). Then, the memory data read processing ends.
The above is the details of the memory data read processing.

Next, details of the memory data write process will be described. FIG. 10 is a flowchart shown in FIG. 9; FIG. In the memory data write process, the processor 121 first sets a predetermined upper limit number of retry times to the variable of the retry counter (step S61). In one example, the value of the upper limit number of retries is 3. Subsequently, processor 121 optionally performs the following processing. That is, a retry processing in-progress flag indicating that the retry processing is in progress is initialized (reset) (step S63). Then, data is written in the toner unit memory 27m (step S65), and it is determined whether or not a communication error has occurred during data writing (step S67).

If no error occurs during data writing (No in step S67), the processor 121 arbitrarily initializes (resets) a retry processing flag indicating that retry processing is in progress (step S75). Then, the memory data write processing ends. Note that the process of step S75 is an optional process paired with step S65. There is no mode in which one process is performed and the other process is not performed, and either both processes are performed or both processes are not performed.

If an error occurs during data writing in step S65 (Yes in step S67), the processor 121 arbitrarily sets a retry processing flag (step S69). Note that the process of step S69 is an arbitrary process paired with step S65. There is no mode in which one process is performed and the other process is not performed, and either both processes are performed or both processes are not performed.
Then, the processor 121 tries to retry the data writing (processing of step S65) in which the error occurred. As a retry procedure, the processor 121 first refers to the retry counter and determines whether or not the value is greater than zero (step S71). If the value of the retry counter is greater than zero (Yes in step S71), the value of the retry counter is decremented by -1 (step S77).

Subsequently, the processor 121 activates the memory reset circuit 127 to once cut off the power supply VCC to the toner unit memory 27m, and then supplies the VCC again (step S79). Then, the processing is returned to the above-described step S65. At step S65, the data is written in the toner unit memory 27m. If the retry data writing succeeds and no error occurs (No in step S67), the retry processing flag is reset (step S75) and the memory data writing processing ends.

On the other hand, if an error occurs again during the retry data writing (Yes in step S67), the retry counter is decremented by -1 as long as the value of the retry counter is equal to or greater than zero, and the retry is repeated. If an error occurs every time the retry is repeated until the value of the retry counter reaches zero (No in step S71), the processor 121 sets the error processing request flag and shifts the MFP 100 to the error state. (Step S73). Then, the retry processing flag is arbitrarily reset (step S75), and the memory data write processing is terminated.
The above is the details of the memory data write processing.

(Embodiment 2)
As shown in FIG. 3, the MFP 100 optionally includes a power saving circuit 129 and a power saving mode controller 137 as a pair. The power saving circuit shifts the MFP 100 from a normal mode in which image forming processing can be started to a power saving mode according to an instruction from the power saving mode control unit 137 . In the power saving mode, the power supply to the control unit 101, the document feeding unit 103, the operation unit 105, the image reading unit 111, and the printing unit 115 is basically cut off to suppress the power consumption of the MFP 100. FIG. Power is supplied only to limited circuits necessary for detecting a trigger operation for returning from the power saving mode to the normal mode, such as some operation keys of the operation unit 105 and part of the power saving circuit 129 .

FIG. 10 shows an example of power saving mode control processing executed by the processor 121 as the power saving mode control unit 137 in this embodiment. In this embodiment, the power saving mode control unit 137 performs processing for instructing the power saving circuit 129 to shift to the power saving mode in the normal mode. In this embodiment, it is assumed that the detection of an event to return to the normal mode from the power saving mode is performed by the circuitry rather than the processing of the processor 121 .
As shown in FIG. 10, the processor 121 as the power saving mode control unit 137 monitors whether or not a predetermined condition for shifting to the power saving mode is satisfied in the normal mode (loop of No in step S81). The predetermined condition is, for example, a state in which a waiting state for receiving a request for a print job continues for a predetermined period (for example, five minutes).

If the condition for shifting to the power saving mode is satisfied (Yes in step S81), the processor 121 determines whether or not the retry processing flag is reset. That is, it is confirmed that the data reading or data writing process of the toner unit memory 27m is not being retryed (step S83). Here, it is assumed that the power saving mode control processing shown in FIG. 10 is processed in parallel with the unit memory access processing shown in FIG. 7 under a multitasking environment.
If the retry processing flag is set (No in step S83), that is, if the retry processing is in progress, the processor 121 waits for a predetermined period (100 milliseconds in one example) and returns to the processing of step S83. Check again whether the retry processing flag has been reset.

If the retry processing in-progress flag is reset or has been reset (Yes in step S83), the processor 121 executes processing to shift the MFP 100 to the power saving mode. That is, an instruction is sent to the power saving circuit 129 to cut off the power supply to the control section 101, the operation section 105, the image reading section 111, the printing section 115, etc. (step S87).
The above is an example of the power saving mode control process.

(Embodiment 3)
As shown in FIG. 3, the multi-function device 100 optionally includes an eject mechanism 45 and an eject control section 139 as a pair. When the toner storage unit 27 is attached to the attachment portion 28 , the ejection mechanism 45 is in a mechanically locked state (locked state) so that the attached toner storage unit 27 cannot be removed without an instruction from the ejection control unit 139 . to For example, when the eject control unit 139 determines that the toner stored in the attached toner storage unit 27 is no longer used, it operates the eject mechanism 45 to release the locked state (unlock state). In the unlocked state, the toner unit memory 27m is disconnected from the main body and cannot be read or written. Therefore, the eject control unit 139 performs control so as not to unlock during retry processing.

FIG. 11 shows an example of ejection control processing executed by the processor 121 as the ejection control unit 139 in this embodiment. In this embodiment, the ejection control unit 139 performs processing for unlocking the toner storage unit 27 attached to the attachment unit 28 . In this embodiment, when the toner storage unit 27 is attached to the attachment portion 28, the locking state of the toner storage unit 27 is mechanically performed by the ejection mechanism 45 without depending on the processing of the ejection control section 139. shall be
As shown in FIG. 11, the processor 121 as the eject control unit 139 monitors whether or not a predetermined condition for ejecting the attached toner containing unit 27 is satisfied (loop of No in step S91). The predetermined condition is, for example, the case where the toner stored in the toner storage unit 27 becomes empty due to the consumption of toner due to the execution of the print job.

When the condition for ejecting the toner containing unit 27 is satisfied (Yes in step S91), the processor 121 determines whether or not the retry processing flag is reset. That is, it is confirmed that the data reading or data writing process of the toner unit memory 27m is not being retryed (step S93). Here, it is assumed that the eject control process shown in FIG. 11 and the unit memory access process shown in FIG. 7 are processed in parallel under a multitasking environment.

If the retry processing flag is set (No in step S93), that is, if the retry processing is in progress, the processor 121 waits for a predetermined period (100 milliseconds in one example) and returns to the processing of step S93. Check again whether the retry processing flag has been reset.
If the retry processing in-progress flag is reset or has been reset (Yes in step S93), the processor 121 executes processing for ejecting the mounted toner containing unit 27 (step S97).
The above is an example of the eject control process.

As mentioned above,
(i) The image forming apparatus according to the present invention includes a mounting section for detachably supporting a consumable unit related to image formation and having a non-volatile memory, and an opening/closing unit for replacing the mounted consumable unit. an open/close sensor for detecting the state of the main body cover, a memory communication circuit for reading and writing data relating to the use of the attached consumable unit to/from a non-volatile memory installed in the consumable unit; a memory reset circuit for resetting a state related to memory read/write; and a control unit for performing a retry after resetting by the memory reset circuit when an error occurs during read/write communication with the nonvolatile memory. The control unit performs the reset and the retry for a communication error that occurs when the body cover is closed, but does not perform the reset and the retry for a communication error that occurs when the body cover is open. and

In the present invention, the consumable unit can be replaced by a user, service engineer, or the like, and the user, service engineer, or the like can access the consumable unit by opening the body cover at the time of replacement. The opening/closing sensor detects opening/closing of the body cover. Specific examples of the consumable unit include toner cartridges containing donors, process cartridges containing photoreceptors, ink cartridges containing ink, and the like. The toner cartridge in the above embodiment corresponds to the consumable unit of the invention.
Also, the non-volatile memory stores data relating to the use of the consumable unit in a readable and writable manner. A specific example thereof is a serial EEPROM. Concrete examples of data related to the use of the consumable unit include, for example, in the case of a toner cartridge, the remaining amount of toner contained therein, the number of prints made using the toner cartridge, and the like.

Furthermore, the memory reset circuit resets the read/write state of the nonvolatile memory to the initial state. As a specific example of this, in the case of a serial EEPROM, if an error occurs in the middle of a read cycle or write cycle and the bus cycle does not end normally, the state before the start of the bus cycle is restored. be. Further, retry is to repeat the bus cycle in which an error occurred in the middle.

Furthermore, preferred embodiments of the present invention will be described.
(ii) The control section may control execution of a job relating to image formation, and perform the reset and the retry only when a communication error occurs during execution of the job.
According to this aspect, the reset and the retry are performed for the communication error that occurred during execution of the job, but the reset and the retry are not performed for the communication error that occurred otherwise. It is assumed that the main body cover is closed while the job is being executed because the image forming operation is basically in progress.

(iii) The control unit may determine that the consumable unit is not attached when the communication error occurs while the body cover is open.
According to this aspect, if the body cover is open, it is determined that the consumable unit is being replaced, and reset and retry are not performed. Since there is no point in retrying in a state where the consumable unit to be read/written is not attached (does not exist), measures should be taken according to the situation.

(iv) The consumable unit may be a consumable unit for each color related to color image formation, and the memory communication circuit and the memory reset circuit may be circuits corresponding to each color.
According to this aspect, when a consumables unit for each color is attached, by providing a memory communication circuit and a memory reset circuit corresponding to each consumables unit, reading and writing of the nonvolatile memory can be performed for each consumables unit. It is possible to handle the error when an error occurs.

(v) the consumable unit is a consumable unit for each color related to color image formation, the memory communication circuit is a circuit corresponding to each color, and the memory reset circuit is a circuit common to some colors; and circuits corresponding to the remaining colors, or a circuit common to all colors.
According to this aspect, by providing a common memory communication circuit and a memory reset circuit for some of the colors of the consumable unit for each color or for all colors, reading and writing of the nonvolatile memory of any of the consumable units is possible. If an error occurs, it is possible to handle the error.

(vi) A power saving circuit that cuts off power supply to the nonvolatile memory and the control unit based on instructions from the control unit, shifts to a power saving mode, and returns from the power saving mode to a normal mode when a predetermined event is detected. In addition, the control unit may suppress an instruction to shift to the power saving mode during the reset and retry processing.
According to this aspect, during the reset and retry processing, it is possible to end the reset and retry processing by suppressing the transition to the power saving mode in which the power supply is cut off and the nonvolatile memory cannot be read or written. .

(vii) further comprising an ejection mechanism that allows the attached consumable unit to be removed from the locked state when the replacement of the consumable unit is required, wherein the control unit controls the operation of the ejection mechanism and the The eject mechanism may not be operated during reset and retry processing.
According to this aspect, during the reset and retry processing, the consumable unit is removed from the main body and the operation of the eject mechanism, which disables reading and writing to the nonvolatile memory, is suppressed to end the reset and retry processing. can be done.

(viii) One aspect of the present invention is a step in which the controller of the image forming apparatus detects the open/closed state of a main body cover that is opened and closed when a detachable consumable unit equipped with a nonvolatile memory is replaced. reading and writing data related to the use of the attached consumable unit with a non-volatile memory mounted in the consumable unit; and if an error occurs during read/write communication with the non-volatile memory, and a step of performing a retry after resetting a state related to reading and writing of the nonvolatile memory, wherein the control unit performs the reset and the retry for a communication error that occurs when the main body cover is closed. is open and a communication error occurs, the reset and the retry are not performed.

Aspects of the present invention also include combinations of any of the aspects described above.
Various modifications of the present invention are possible in addition to the above-described embodiments. Those modifications should not be construed as not belonging to the scope of the present invention. The present invention should include all modifications within the scope of the claims, the meaning of equivalents, and the scope.

11: Optical scanning unit 12: Developing unit 13: Photoreceptor drum 14: Charger 15: Drum cleaner 16: Primary transfer roller 17: Fixing unit 18a, 18b, 18c, 18d: Paper feed tray 19: Manual feed tray 21: Intermediate transfer belt 22: Belt cleaner 23: Secondary transfer unit 24: Heat roller 25: Pressure roller 27: Toner storage unit 28: Mounting unit 29: Waste toner collection container 30, 30y, 30m, 30c, 30k: process unit 31: front door 33: open/close sensor 36: ejection roller 37: double-sided transport path 39a, 39b: ejection tray 41: image processing circuit 45: Eject Mechanism 100: MFP 101: Control Section 103: Document Feeding Unit 105: Operation Section 111: Image Reading Section 115: Printing Section 121: Processor 122: RAM 123: Main Body Nonvolatile Memory 125: Memory Communication Circuit 127: Memory Reset Circuit 129: Power Saving Circuit 133: Image Forming Control Section 135: Unit Memory Access Section 137: Power Saving Mode Control Section 139: Eject Control Section

Claims (8)

a mounting part that detachably supports a consumable unit related to image formation with a non-volatile memory mounted on the main body;
an open/close sensor that detects the state of the body cover that is opened and closed when the attached consumable unit is replaced;
a memory communication circuit that reads and writes data related to the use of the mounted consumable unit with a non-volatile memory mounted on the consumable unit;
a memory reset circuit that resets a state related to reading and writing of the nonvolatile memory;
a control unit that, when an error occurs during read/write communication with the nonvolatile memory, performs a retry after resetting by the memory reset circuit;
The image forming apparatus, wherein the control unit performs the reset and the retry for a communication error that occurs when the body cover is closed, but does not perform the reset and the retry for a communication error that occurs when the body cover is open. The control unit controls execution of jobs related to image formation,
2. The image forming apparatus according to claim 1, wherein said reset and said retry are performed only when a communication error occurs during execution of said job. 2. The image forming apparatus according to claim 1, wherein the control unit determines that the consumable unit is not installed in a communication error that occurs when the body cover is open. wherein the consumable unit is a consumable unit for each color related to color image formation;
4. The image forming apparatus according to claim 1, wherein said memory communication circuit and said memory reset circuit are circuits corresponding to respective colors. The mounting unit is a consumable unit for each color related to color image formation,
The memory communication circuit is a circuit corresponding to each color, and the memory reset circuit is a combination of a circuit common to some colors and a circuit corresponding to the remaining colors, or a circuit common to all colors. Item 4. The image forming apparatus according to any one of items 1 to 3. a power saving circuit that cuts off power supply to the non-volatile memory and the control unit based on instructions from the control unit, shifts to a power saving mode, and returns from the power saving mode to a normal mode when a predetermined event is detected,
2. The image forming apparatus according to claim 1, wherein the control unit suppresses an instruction to shift to the power saving mode during the reset and retry processing. further comprising an eject mechanism that allows the attached consumable unit to be removed from the locked state when the consumable unit needs to be replaced;
2. The image forming apparatus according to claim 1, wherein the control section controls the operation of the eject mechanism and does not operate the eject mechanism during the reset and retry processes. The control unit of the image forming apparatus
a step of detecting the open/closed state of a body cover that is opened and closed when a detachable consumable unit equipped with a nonvolatile memory is replaced;
reading and writing data relating to the use of the attached consumable unit to and from a non-volatile memory onboard the consumable unit;
When an error occurs during read/write communication with the non-volatile memory, resetting the state related to read/write of the non-volatile memory and then performing a retry;
The controller performs the reset and the retry for a communication error that occurs while the main body cover is closed, but does not perform the reset and the retry if the communication error occurs while the main body cover is open. Communication control method with.