JP2020114642A - Image forming device - Google Patents

Abstract

To provide a mechanism that can perform abnormality diagnosis with a simple structure and appropriately specify an abnormality without depending on an abnormality occurrence place.SOLUTION: The image forming device comprises a controller substrate (a first control part) and a slave substrate that is connected to the controller substrate through communication line and controls a load. The controller substrate comprises a logic part that if an error occurs, outputs a signal to the slave substrate, which further comprises a buffer for both input and output which has an output buffer that outputs the signal outputted from the logic part to the slave substrate through a predetermined port on the communication line and an input buffer that is inputted with the signal outputted from the output buffer and then outputs the signal to the logic part. Further, the controller substrate performs abnormality diagnosis of determining whether an abnormality occurs in the controller substrate or not, on the basis of the signal inputted to the logic part.SELECTED DRAWING: Figure 2

Description

The present invention relates to an image forming apparatus that performs abnormality diagnosis.

The method of driving and controlling a plurality of loads of the image forming apparatus by one controller has a problem that the space and cost for wiring between the controller and each load increase as the size of the apparatus increases and the load increases. is there. Therefore, as a method for solving such a problem, there is a control method in which a slave controller indirectly drives a load arranged at a position away from the controller. Further, by using serial communication between the master controller and the slave controller, wiring can be reduced as compared with the case where parallel signal lines are used. In such serial communication between the master controller and the slave controller, it is not easy to identify the cause of the abnormality that has occurred.

Patent Document 1 proposes a method in which a failure diagnosis unit is provided on the master controller side and a printer diagnosis unit and a printer switch are provided on the slave controller side to identify an abnormality generated by the update diagnosis unit. Specifically, when a communication error occurs between the master controller and the slave controller, the signal diagnosed by the printer diagnostic unit in the slave controller is switched from the communication signal to the signal diagnosed by the printer unit switch to notify the failure diagnostic unit. doing.

In addition, in a buffer unit used in a general-purpose logic IC, ASIC, FPGA, etc., an input/output buffer whose use can be switched between an input buffer and an output buffer by using an Output Enable signal is generally known.

JP, 2016-221873, A

However, the above-mentioned conventional techniques have the following problems. In the above-mentioned conventional technique, referring to FIG. 8, when the serial I/F signal output from the serial I/F 801 has an open failure at the location A, the signal is normally input to the failure diagnosis unit 802. However, on the slave controller side, there is no signal input and an abnormal state occurs. In this case, although the occurrence of the abnormality can be detected, there is a problem that the abnormal portion that has occurred between the master controller and the slave controller cannot be specified. Further, even when the output buffer 803 fails, even if the serial I/F signal output from the serial I/F is also abnormal, the failure diagnosis unit 802 normally inputs the signal, and therefore the abnormal location. Cannot be identified.

The present invention has been made in view of at least one of the above-mentioned problems, and provides a mechanism for performing abnormality diagnosis with a simple configuration and suitably specifying an abnormality without depending on the occurrence location. To aim.

The present invention is, for example, an image forming apparatus, which includes a first control unit and a second control unit that is connected to the first control unit via a communication line and controls a load, and the first control unit is When an error occurs, a logic unit that outputs a signal to the second control unit and a signal output from the logic unit are output to the second control unit via a predetermined port on a communication line. An input/output buffer having an output buffer and an input buffer that receives the signal output from the output buffer and outputs the signal to the logic unit; and the first buffer based on the signal input to the logic unit. And a control means for performing an abnormality diagnosis for determining whether or not an abnormality has occurred in the control unit.

According to the present invention, it is possible to perform abnormality diagnosis with a simple configuration and to appropriately identify the abnormality without depending on the occurrence location.

FIG. 1 is a diagram showing a configuration of an image forming apparatus according to an embodiment. The figure which shows the control block which concerns on one Embodiment. FIG. 3 is a diagram showing a configuration block of a buffer unit according to an embodiment. The control flowchart which concerns on one Embodiment. The flowchart of the diagnostic mode which concerns on one Embodiment. The figure which shows the control block which concerns on one Embodiment. The flowchart of the diagnostic mode which concerns on one Embodiment. The figure which shows the control block used as a comparative example.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings. The following embodiments do not limit the invention according to the claims. Although a plurality of features are described in the embodiment, not all of the plurality of features are essential to the invention, and the plurality of features may be arbitrarily combined. Further, in the accompanying drawings, the same or similar components are designated by the same reference numerals, and duplicated description will be omitted.

The image forming apparatus of the present embodiment is, for example, an image forming apparatus that forms an image on a sheet by an electrophotographic method, such as a printing apparatus (printer), a copying machine, a multifunction machine (MFP), or a facsimile apparatus, or image processing. It is applicable as a device, an information processing device, and a communication device. The multifunction device is a device having at least two or more functions out of a plurality of types of functions including, for example, a print function, a scan function, a copying function, and a facsimile function. Here, a case where the image forming apparatus is a printing apparatus (printer) will be described.

<First Embodiment>
<Configuration of printing device>
Hereinafter, the first embodiment of the present invention will be described. First, a configuration example of the printing apparatus according to the present embodiment will be described with reference to FIG. In this embodiment, the printing apparatus 100 of the electrophotographic process will be described as an example. As shown in FIG. 1, the printing apparatus 100 includes a photoconductor 101, a primary charging unit 102, a potential sensor 103, an exposure unit 104, a developing unit 105, a transfer unit 106, and a cleaner 107 as main image forming configurations. ..

An image forming operation of the printing apparatus having the above configuration will be described. After the photosensitive member 101 is uniformly charged by the primary charging unit 102, the exposure unit 104 exposes the photosensitive member 101 to form an electrostatic latent image on the photosensitive member 101. The potential sensor 103 is provided between the exposure unit 104 and the developing unit 105 in order to measure the potential of the electrostatic latent image.

Then, the electrostatic latent image is developed as a toner image by the developing unit 105, and the toner image on the photoconductor 101 is transferred to the recording paper 110 by the transfer unit 106. The transfer residual toner remaining on the photoconductor 101 is collected by the cleaner 107. The toner image transferred onto the recording paper 110 is fixed by the fixing unit 108, so that a product on which the image is printed can be obtained.

Next, the paper feeding operation of the printing apparatus having the above configuration will be described. When the recording paper 110 is fed from the paper feed cassette 120, when a signal for starting the paper feed operation is issued, the sensor 131 first detects the presence or absence of the recording paper 110 in the paper feed cassette 120. When the recording paper 110 is in the paper feed cassette 120, the stepping motor 121 is driven, and the driving force is transmitted to the paper feed roller 122. As a result, the paper feed roller 122 rotates, and the recording paper 110 is fed from the paper feed cassette 120 one by one. The sensor 132 detects whether the recording paper 110 has passed within a predetermined timing. Then, it passes through the transport roller 124 driven by the stepping motor 123. The sensor 133 detects whether the recording paper 110 has passed within a predetermined timing. Similarly, the recording paper 110 is conveyed by the conveyance roller 126 driven by the stepping motor 125, and the recording paper 110 is conveyed to the transfer unit 106.

<Control configuration of printing device>
Next, the control configuration of the printing apparatus 100 according to this embodiment will be described with reference to FIG. The printing apparatus 100 includes a controller board 201 that is a master board and a slave board 220. The controller board 201 is a first control unit and includes a CPU 202 and a master controller 203. On the other hand, the slave board 220 is a second controller and includes a slave controller 223.

The CPU 202 provided on the controller board 201 centrally controls the printing apparatus 100. The CPU 202 is connected to a master controller 203 such as a SoC (System on Chip), an ASIC (application specific integrated circuit), or an FPGA (field-programmable gate array) by a bus. The master controller 203 is connected by serial communication 241 to the slave controller 223 of the slave substrate 220 that carries recording paper and forms images.

The logic unit 204 in the master controller 203 includes a register unit 206 and a serial communication I/F 207 that performs communication between the controllers. The buffer unit 205 also includes buffers 205a to 205d. Each buffer includes a buffer 205a that outputs a RESET signal 240, a buffer 205b that outputs an output signal (TX signal) from the master controller 203, and a buffer 205c that receives an input signal (RX signal) to the master controller 203. included. Also in this embodiment, the input buffer is provided with a buffer unit in order to convert the voltage to the ASIC internal logic core and improve the driving capability of the output signal. The abnormality diagnosis described below may be performed for each of the signals (TX signal, RX signal, RESET signal).

Like the master controller 203, the logic unit 224 of the slave controller 223 includes a register unit 226 and a serial communication I/F 227. Further, the logic unit 224 includes a motor control unit 228 that controls the motor 121 and a sensor control unit 229 that controls the sensors 131 and 132. The buffer unit 225 has buffers 225a to 225d. Further, the motor 121 and the sensors 131 and 132 are connected to the slave substrate 220.

<Detailed configuration>
Next, a detailed configuration of the buffer units 205 and 225 in the present embodiment will be described with reference to FIG. Here, the buffer 205b in the buffer unit 205 will be described as an example. The buffer 205b is an input/output buffer, and can switch between the input signal buffer and the output signal buffer according to the application by the OE signal from the logic unit 204.

The buffer 205b includes an input buffer 260 and an output buffer 261. When the buffer 205b is used as an output buffer, Output Enable (hereinafter OE) is enabled (OE is at “L” level), and the OUT signal from the logic unit 204 is output from the terminal 263 via the output buffer 261. Is output. When the buffer 205b is used as an input buffer, OE is disabled (OE is at “H” level), and a signal input through the terminal 263 is input to the logic unit 204 as an IN signal through the input buffer 260. Is entered.

Note that when the buffer 205b is used as an output buffer, OE is enabled (OE is at “L” level), and an OUT signal from the logic unit 204 is output to the logic unit via the output buffer 261 and the input buffer 260. The signal can be input to the signal 204 again. The other buffers 205a, 205c, 205d and the buffers 225a to 225d have the same configuration as the buffer 205b, and thus detailed description thereof will be omitted.

<Job processing procedure>
Next, with reference to FIG. 4, a processing procedure when a job according to this embodiment is accepted will be described. The processing described below may be realized, for example, by the CPU 202 reading a control program stored in advance in the ROM or the like into the RAM and executing the control program.

First, in step S402, the CPU 202 determines whether a job has been submitted. When a job is submitted, the process proceeds to S403. In step S403, the CPU 202 initializes the image forming unit and the driving unit of the printing apparatus 100 according to the received job, and starts the operation.

After that, in S404, the CPU 202 determines whether or not an error has occurred in the serial communication between the controller board 201 and the slave board 220. For example, here, a cyclic redundancy check (CRC) may be used to detect an error that occurs during data transfer of transmission/reception data. If no error occurs, the process proceeds to S405, and if an error occurs, the process proceeds to S421.

In S405, the CPU 202 prints out. After that, in step S406, the CPU 202 determines whether or not the print job (designated number of output sheets) is completed. If not completed, the process returns to step S404 to check again for the occurrence of a communication error, and is completed. If so, the process proceeds to S407. In S407, the CPU 202 determines whether or not there is a next job. If there is no next job, the process advances to step S408, the CPU 202 stops the operations of the image forming unit and the driving unit of the printing apparatus 100, ends the process, and returns to the standby state. On the other hand, if there is a next job in S407, the process returns to S404 to check whether a communication error has occurred.

The case of transition to the diagnostic mode, which is a feature of the present invention, will be described. If a CRC communication error is detected in step S404, the processing proceeds to step S421, and the CPU 202 stops the operations of the image forming unit and the driving unit of the printing apparatus 100. Subsequently, in step S422, the CPU 202 implements the diagnostic mode, the device stops in an error state, and the process ends. Detailed processing of the diagnostic mode will be described later with reference to FIG. When stopped in an error state, a message specifying the error state or the failure point can be displayed on an operation unit (display unit) (not shown) or the like.

In the flowchart of FIG. 4, a flowchart during execution of a job is shown, but the present invention is not limited to this, and may be executed during a job other than during a job, for example, during standby. Thereby, for example, when the information such as the sensor is confirmed by the communication during the standby, it is possible to deal with the case where the communication abnormality occurs.

<Processing procedure in diagnostic mode>
Next, with reference to FIG. 5, a processing procedure in the diagnostic mode in the present embodiment will be described. The processing described below may be realized, for example, by the CPU 202 reading a control program stored in advance in the ROM or the like into the RAM and executing the control program.

First, in S502, when the CPU 202 transitions to the diagnostic mode, the CPU 202 diagnoses the TX signal (output signal) that is the output signal from the master controller 203 of the serial communication 241. Subsequently, in step S503, the CPU 202 causes the serial communication I/F 207 to output a TX signal, and enables the register unit 206 to enable the OE of the buffer unit 205b (the OE is at the “L” level). Even during the serial communication, the OE of the TX signal is controlled to be valid (OE is at "L" level).

Next, in step S<b>504, the CPU 202 monitors the input signal (IN) via the input buffer 260 in the register unit 206 of the logic unit 204 and confirms whether the TX signal output in step S<b>503 is undergoing a desired change. .. Then, if the TX signal changes as desired, the process proceeds to S505, and if not, the process proceeds to S510. In S505, the CPU 202 determines that the master controller 203 is operating normally, and ends the diagnostic mode. On the other hand, in S510, the CPU 202 determines that an abnormality has occurred in the master controller 203, and ends the diagnostic mode. After that, for example, when the master controller 203 is determined to be abnormal, the CPU 202 may display on the operation unit (not shown) that an abnormality has occurred in the controller board 201 including the master controller 203.

As described above, the image forming apparatus according to the present embodiment includes the controller board (first control unit) and the slave board that is connected to the controller board by the communication line and controls the load. The controller board includes a logic unit that outputs a signal to the slave board when an error occurs. In addition, the signal output from the logic unit is output to the logic unit by using an output buffer that outputs the signal to the slave substrate through a predetermined port on the communication line and the signal output from the output buffer. And an input/output buffer having an input buffer for performing input/output. Further, the controller board performs abnormality diagnosis for determining whether or not an abnormality has occurred in the controller board based on the signal input to the logic unit. As described above, in the present embodiment, by using the I/O buffer, it is possible to specify the failure location with a relatively simple configuration without separately providing a circuit for abnormality diagnosis. For example, even if an open failure occurs at the point A in FIG. 8, the failure of the master controller 203 can be detected in the configuration of this embodiment. Further, even if the output buffer 803 in FIG. 8 fails, it can be detected that the master controller 203 has failed.

In the present embodiment, an example has been described in which it is determined whether an abnormality has occurred in the master controller 203 (controller board 201). However, the present invention is not limited to such control. For example, as shown in FIG. 2, since the slave substrate 220 also has the same logic unit and buffer unit, the slave substrate 220 may be alternatively or additionally provided. It may be possible to determine whether or not an abnormality has occurred. When both the master controller 203 and the slave board 220 determine an abnormality, the abnormality location can be specified in more detail and with higher accuracy, and more accurate information can be presented to the user.

<Second Embodiment>
Below, the 2nd Embodiment of this invention is described. In the first embodiment, the abnormality diagnosis in serial communication has been described, but in the present embodiment, abnormality diagnosis of power supply will be described. It should be noted that the processing procedure of the job processing in the standby state of FIG. 4 described in the first embodiment is the same in this embodiment, and thus the description thereof is omitted.

<Control configuration of printing device>
First, the control configuration of the printing apparatus according to the present embodiment will be described with reference to FIG. The same components as those in FIG. 2 are designated by the same reference numerals and the description thereof will be omitted.

A power supply for supplying 3.3V power from the controller board 201 to the slave board 220 is provided. The 3.3V power supply is connected to the CPU 202, the master controller 203, and the slave controller 223. The power supply diagnostic unit 601 diagnoses whether or not there is an abnormality in the 3.3V power supply supplied to the slave board 220. More specifically, the power supply diagnostic unit 601 determines whether or not an abnormality has occurred in the controller board 201. The result detected by the power source diagnosis unit 601 is input to the master controller 203. The CPU 202 can refer to the result detected by the power source diagnosis unit 601 via the master controller 203.

<Processing procedure in diagnostic mode>
Next, with reference to FIG. 7, a processing procedure of the diagnostic mode in the present embodiment will be described. The processing described below may be realized, for example, by the CPU 202 reading a control program stored in advance in the ROM or the like into the RAM and executing the control program.

First, in step S<b>702, the CPU 202 performs power supply diagnosis when transitioning to the diagnosis mode. Then, the CPU 202 determines whether or not the 3.3V power supply to the slave board 220 is normal. If the CPU 202 determines that an abnormality has occurred, the CPU 202 determines that an abnormality has occurred in the controller board 201, and ends the diagnostic mode.

On the other hand, in the power supply diagnosis, when it is determined that the 3.3V power supply is operating normally, the process proceeds to step S711, and the CPU 202 performs output signal diagnosis of the TX signal and the RESET signal 240. In step S712, the CPU 202 controls the register unit 206 so that the OE of the buffer unit 205b is valid (the OE is at the “L” level). Even during the serial communication, the OE of the TX signal is controlled to be valid (the OE is at the “L” level). Similarly, the CPU 202 also controls the OE of the RESET signal buffer unit 205a to be valid (the OE is at the “L” level). Even in the normal operation, the OE of the RESET signal is controlled to be valid (the OE is at "L" level).

Next, in step S<b>713, the CPU 202 monitors the input signal (IN) via the input buffer 260 in the register unit 206 of the logic unit 204 and confirms whether the TX signal output in step S<b>712 is undergoing a desired change. If the TX signal does not change as desired, the process proceeds to S704, the CPU 202 determines that the TX signal is abnormal, determines that the controller board 201 is abnormal, and ends the diagnostic mode.

On the other hand, if it is determined in S713 that the TX signal is normal, the process proceeds to S714, in which the CPU 202 confirms in the register unit 206 of the logic unit 204 whether the RESET signal makes a desired change. If the RESET signal does not change as desired, it is determined that the RESET signal is abnormal and the process proceeds to step S704. The CPU 202 determines that an abnormality has occurred in the controller board 201, and ends the diagnostic mode. On the other hand, if it is determined in S714 that the RESET signal is normal, the process proceeds to S715, in which the CPU 202 determines that the controller board 201 is normal and ends the diagnostic mode.

After that, the CPU 202 displays on the operation unit (display unit) (not shown) that an abnormality has occurred in the controller board 201 when passing through S704, and when passing through S715, the abnormality occurs in the slave board 220. May be displayed.

As described above, in the image forming apparatus according to the present exemplary embodiment, in addition to the configuration of the first exemplary embodiment, the power supply monitoring unit also monitors the supply error of the power supply, and the error occurs based on the monitoring result. Time abnormality diagnosis. Thereby, the error can be specified in more detail.

<Other embodiments>
The present invention supplies a program that implements one or more functions of the above-described embodiments to a system or apparatus via a network or a storage medium, and one or more processors in a computer of the system or apparatus read and execute the program. It can also be realized by the processing. It can also be realized by a circuit (for example, ASIC) that realizes one or more functions.

The invention is not limited to the above-described embodiments, and various changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, the following claims are attached to open the scope of the invention.

100: printing device, 101: photoconductor, 102: primary charging part, 103: potential sensor, 104: exposure part, 105: developing part, 106: transfer part, 107: cleaner, 110: recording paper, 120: paper feed Cassette, 121: Stepping motor, 127: Image reading device, 131: Sensor, 201: Controller board, 202: CPU, 203: Master controller, 220: Slave board, 223: Slave controller, 601: Power diagnosis section

Claims (10)

An image forming apparatus,
A first controller,
A second control unit that is connected to the first control unit via a communication line and controls a load;
The first control unit,
A logic unit that outputs a signal to the second control unit when an error occurs;
An output buffer that outputs a signal output from the logic unit to the second control unit through a predetermined port on a communication line, and a signal output from the output buffer as an input to the logic unit An input/output buffer having an input buffer for outputting a signal,
An image forming apparatus, comprising: a control unit that performs abnormality diagnosis for determining whether or not an abnormality has occurred in the first control unit based on a signal input to the logic unit. The image forming apparatus according to claim 1, wherein the control unit specifies which of the first control unit and the second control unit has an abnormality from the result of the abnormality diagnosis. The control means is
With respect to the signal output from the input buffer of the input/output buffer, a value in a register provided in the logic unit is monitored to determine whether or not an abnormality has occurred in the first control unit. The image forming apparatus according to claim 2, wherein The first control unit,
A power supply for supplying power from the first control unit to the second control unit,
Further comprising a power supply monitoring means for monitoring the power supply,
The control means is
The image forming apparatus according to claim 2, wherein the abnormal portion is identified based on a monitoring result of the power supply monitoring unit. The control means is
The image forming apparatus according to claim 2, wherein the result of the abnormality diagnosis is displayed on the display unit of the image forming apparatus together with the identified abnormal portion. The image forming apparatus according to claim 2, wherein the signal output from the logic unit is at least one of a TX signal and a RESET signal. A plurality of ports are provided in the communication line between the first control unit and the second control unit,
7. The image forming apparatus according to claim 2, wherein the I/O buffer is provided corresponding to each of the plurality of ports. The second control unit is
A second logic unit that outputs a signal to the first control unit when an error occurs;
An output buffer that outputs a signal output from the second logic unit to the first control unit via a predetermined port on a communication line; and a signal output from the output buffer as an input, A second input/output buffer having an input buffer that outputs a signal to two logic units,
The control means is
The image forming apparatus according to any one of claims 2 to 7, wherein abnormality diagnosis is performed by both the first control unit and the second control unit. The control means is
9. The image according to claim 2, wherein execution of the job is stopped after the error has occurred and before the signal is output to the second control unit by the logic unit. Forming equipment. The image forming apparatus according to claim 2, wherein serial communication is performed via the communication line.

Images