Image forming apparatus, control method for image forming apparatus, and control program for image forming apparatus

Abstract

This system suppresses on-hook activation when an overcurrent from the communication line is mistakenly detected by the overcurrent protection circuit, while simultaneously enabling on-hook activation and external notification when an actual overcurrent occurs. [Solution] The image forming apparatus is characterized by comprising: an image forming unit that forms an image; an operation unit including a display unit; an overcurrent protection circuit that, when an overcurrent is detected from a communication line while in the ON state, activates a protection function to protect against overcurrent and stops the overcurrent detection operation from the communication line while in the OFF state; a transmitting and receiving unit that transmits and receives image data to and from the communication line; a determination unit that, when an overcurrent is detected by the overcurrent protection circuit, determines whether or not the line current input from the communication line is above a threshold; and a notification unit that notifies the operation unit that the determination unit has determined that the line current is above the threshold and causes the display unit to display a message indicating the occurrence of an overcurrent.

Description

Technical Field

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[0001] The present invention relates to an image forming apparatus, a control method for the image forming apparatus, and a control program for the image forming apparatus.

Background Art

[0002] In a facsimile apparatus, there is known one having an overcurrent protection function that detects an overcurrent when a line is captured and releases the line. In this type of facsimile apparatus, when a call signal is detected, off-hook is performed after controlling so that the overcurrent protection function does not operate, and in a state where a call signal is not detected, by controlling so that the overcurrent protection function operates, it is possible to prevent the off-hook at the time of reception from failing (see, for example, Patent Document 1).

Summary of the Invention

Problems to be Solved by the Invention

[0003] For example, the detection of an overcurrent is performed by comparing the current value of the overcurrent detection target with a threshold value by an overcurrent protection circuit. However, the threshold value generated in the overcurrent protection circuit may be lower than the standard value such as the upper limit value of the current due to variations in the characteristics of the device on which the overcurrent protection circuit is mounted. When the threshold value becomes lower than the standard value, the overcurrent protection circuit may detect a normal current value as an overcurrent. When the overcurrent protection circuit detects a normal current value as an overcurrent and activates the protection function, it suppresses the normal current input from the line to the device. As a result, there is a problem that although the current value is normal, the line is forcibly on-hooked during communication. <​​​​​​​​​To solve the above technical problems, one embodiment of the present invention is an image forming apparatus comprising: an image forming unit for forming an image; an operation unit including a display unit; an overcurrent protection circuit that, when an overcurrent is detected from a communication line while in the ON state, activates a protection function to protect against overcurrent and stops the overcurrent detection operation from the communication line while in the OFF state; a transmitting and receiving unit for transmitting and receiving image data to and from the communication line; a determination unit that, when an overcurrent is detected by the overcurrent protection circuit, determines whether or not the line current input from the communication line is above a threshold; and a notification unit that notifies the operation unit that the determination unit has determined that the line current is above the threshold and causes the display unit to display a message indicating the occurrence of an overcurrent. [Effects of the Invention]

[0006] This system can suppress on-hook activation when an overcurrent from the communication line is mistakenly detected by the overcurrent protection circuit, while simultaneously enabling on-hook activation and external notification when an actual overcurrent occurs. [Brief explanation of the drawing]

[0007] [Figure 1] This is a block diagram illustrating the hardware overview of an image forming apparatus according to one embodiment of the present invention. [Figure 2] Figure 1 is a block diagram showing an example of a fax control board. [Figure 3] Figure 1 shows an example illustrating the normal operation of the FAX control board and the operation that demonstrates the problems encountered before implementing the present invention. [Figure 4] Figure 2 is a flowchart showing an example of the operation of the FAX control board. [Figure 5] This figure shows an example of a message displayed on the control panel based on the notification to the control unit in step S22 of Figure 4. [Modes for carrying out the invention]

[0008] Embodiments will be described below with reference to the drawings. In each drawing, the same components are denoted by the same reference numerals, and redundant explanations may be omitted. A single line or arrow indicating a signal line may indicate multiple signal lines, and a single line or arrow may include a power line.

[0009] (Overview of the image forming apparatus) Figure 1 is a block diagram illustrating the hardware overview of an image forming apparatus according to one embodiment of the present invention. For example, the image forming apparatus 100 shown in Figure 1 is a device that operates by receiving power from a commercial AC power supply, and is a digital multifunction device having functions such as copying, printing, and facsimile. Digital multifunction devices are also called MFPs (Multifunction Printers).

[0010] The image forming apparatus 100 includes a power supply unit 10, an engine control board 20, a scanner 30, a printer 40, a controller control board 50, an operation unit 60, and a fax control board 70. The operation unit 60 includes an operation panel 62 and a display control unit 64. The fax control board 70 includes a detection unit 72 and a notification unit 74.

[0011] The power supply unit 10 converts the AC voltage supplied from the commercial power supply into several types of DC voltages. The power supply unit 10 supplies the converted DC voltages to the scanner 30, printer 40, controller control board 50, operation unit 60, and fax control board 70 via the engine control board 20. For example, the printer 40 is a tandem laser printer. Note that the printer 40 may also be an inkjet printer.

[0012] For example, each of the engine control board 20, controller control board 50, FAX control board 70, and operation unit 60 has a processor such as a CPU (Central Processing Unit) (not shown). The engine control board 20 controls the supply of power to the scanner 30 and printer 40, etc., based on a control program executed by the built-in processor. For example, the processor of the engine control board 20 executes an image processing program or a data processing program to perform image processing on image data generated by the scanning operation of the scanner 30, and forms image data to be output to the printer 40. The engine control board 20 is an example of an image forming unit that forms an image.

[0013] The controller control board 50 manages the overall operation of the image forming apparatus 100, including the operation of the scanner 30, the printer 40, and the facsimile, based on a control program executed by its built-in processor.

[0014] The operation unit 60 includes an operation panel 62 and a display control unit 64. The operation panel 62 receives various inputs in response to user operations and displays various information. The operation panel 62 is an example of a display unit. Based on a control program executed by the built-in processor, the operation unit 60 receives operations on the operation panel 62 and causes the controller control board 50 to implement scanner functions via the scanner, printer functions via the printer, or fax functions via the fax control board.

[0015] The display control unit 64 controls the operation panel 62 to display a message for the user or a service technician maintaining the image forming apparatus 100, based on a notification from the notification unit 74 of the FAX control board 70. The operation panel 62 displays the message based on the control by the display control unit 64.

[0016] The processor in the operation unit 60 may also have a function to control the operating mode of the image forming apparatus 100. For example, in energy-saving mode, the processor in the operation unit 60 may cut off the power supply to the processor of the engine control board 20 and the processor of the controller control board 50.

[0017] The processor in the operation unit 60 may supply power to the processor in the controller control board 50 and start up the processor when transitioning from energy-saving mode to normal mode. Alternatively, the processor in the operation unit 60 may supply power to the processor in the engine control board 20 and start up the processor based on receiving a scan or print instruction from the user.

[0018] The FAX control board 70 controls the transmission and reception of facsimile using a public telephone line based on a control program executed by its built-in processor. A public telephone line is an example of a communication line. The detection unit 72 detects the current input to the FAX control board 70 from the public telephone line and the voltage of the public telephone line. For example, the detection unit 72 detects whether the current input to the FAX control board 70 is an overcurrent. The notification unit 74 notifies the operation unit 60 that the detection unit 72 has detected an overcurrent. An example of the configuration of the FAX control board 70 is shown in Figure 2.

[0019] (An example of a fax control board) Figure 2 is a block diagram showing an example of the FAX control board 70 shown in Figure 1. The FAX control board 70 enables the image forming apparatus 100 to operate as a facsimile machine. The FAX control board 70 communicates with other facsimile machines connected to the public telephone network via a LINE port, thereby enabling the image forming apparatus 100 to send and receive image data between itself and other facsimile machines. The LINE port is connected to the public telephone network via a signal line.

[0020] The FAX control board 70 has a CPU 701 that functions as a modem, a SRAM (Static Random Access Memory) 702, a FROM (Flash Read Only Memory) 703, and a DRAM (Dynamic Random Access Memory) 704. Also, the FAX control board 70 has a SiDAA (SSD) 705, a SiDAA (LSD) 706, a primary-side communication circuit 707, a speaker drive circuit 709, a lightning surge protection circuit 710, an off-hook detection circuit 711, a ringing circuit 712, and a relay 713. SiDAA is an abbreviation for Silicon Data Access Arrangement. SSD is an abbreviation for System Side Device. LSD is an abbreviation for Line Side Device.

[0021] The CPU 701 controls the operations of each element within the FAX control board 70 by executing, for example, the control program stored in the FROM 703. For example, the CPU 701 realizes the functions of the detection unit 72 and the notification unit 74 shown in FIG. 1 by executing the control program. Note that the CPU 701 may measure the voltage of the public line using the function of the detection unit 72 when the power supply of the image forming apparatus 100 is started, and display the measurement result on the operation panel 62. The CPU 701 that measures the voltage of the public line when the power supply is started and displays the measurement result on the operation panel 62 is an example of a measurement unit.

[0022] The CPU 701 modulates / demodulates image data and voice data, and performs tone detection or transmission, etc. For example, the image data is data that is acquired by the scanner 30 in FIG. 1 and generated by an image processing unit provided within the engine control board 20 in FIG. 1, and is transmitted to another facsimile apparatus via the LINE port. Also, the image data is data that is received from another facsimile apparatus via the LINE port, printed by the printer 40, or displayed on the operation panel 62 in FIG. 1. The voice data is input / output via the LINE port.

[0023] SRAM 702 is used as the working memory of CPU 701. FROM 703 holds the FAX control program executed by CPU 701, the OS (Operating System), etc. DRAM 704 is used as the working memory of CPU 701, and stores image data etc. input / output via the LINE port.

[0024] SiDAA (SSD) 705, SiDAA (LSD) 706, and the primary-side communication circuit 707 implement a network control unit (NCU; Network Control Unit) 708. Communication via the public line becomes possible by the modem function of CPU 701 and the network control unit 708. The speaker drive circuit 709 causes the speaker SP to sound under the control of SiDAA (SSD) 705. CPU 701 and the network control unit 708 are an example of a transceiver unit.

[0025] The lightning surge protection circuit 710 has a protection function to protect the primary-side communication circuit 707 etc. from overcurrent from the public line via, for example, the TEL port. The lightning surge protection circuit 710 is an example of an overcurrent protection circuit. When CPU 701 detects off-hook, for example, it operates (turns on) the overcurrent protection function of the lightning surge protection circuit 710, and when it detects on-hook, it stops (turns off) the overcurrent protection function of the lightning surge protection circuit 710.

[0026] When the lightning surge protection circuit 710 detects an overcurrent from the public line during the on state, it increases the resistance value of the current path to the primary-side communication circuit 707, thereby reducing the current flowing through the primary-side communication circuit 707 to protect the primary-side communication circuit 707 from overcurrent. The lightning surge protection circuit 710 stops the detection operation of overcurrent from the communication line during the off state, and does not increase the resistance value of the current path to the primary-side communication circuit 707 even when an overcurrent occurs from the public line.

[0027] The off-hook detection circuit 711 detects an off-hook operation, which is the operation of removing the handset of an external telephone connected to the TEL port, when the external telephone is able to connect to a public telephone line. When the off-hook detection circuit 711 detects an off-hook, it notifies the CPU 701 of the off-hook detection. If the CPU 701 does not receive notification of an off-hook detection from the off-hook detection circuit 711, it detects an on-hook.

[0028] The ringing circuit 712 rings the external telephone connected to the TEL port when the external telephone can connect to a public telephone line via the LINE port, based on the control of the CPU 701.

[0029] Relay 713 connects the external telephone to the public telephone line when the external telephone is connectable to the public telephone line. Based on control by CPU 701, relay 713 switches between connecting the external telephone directly to the public telephone line or connecting it to the public telephone line via the FAX control board 70. For example, when relay 713 is ON, the external telephone is connected to the public telephone line via the FAX control board 70. When relay 713 is OFF, the external telephone is connected directly to the public telephone line. Figure 2 shows the case when relay 713 is OFF.

[0030] (Description of the assignment) Figure 3 is a diagram illustrating an example of the normal operation of the FAX control board shown in Figure 1 and the operation that illustrates the problems before implementing the present invention. The threshold value (standard value) is set to a value higher than the standard current value that flows from the public line to the lightning surge protection circuit 710. The specified current value is determined, for example, during the design of the FAX control board 70, so that the value of the current flowing to the lightning surge protection circuit 710 during the normal operation of the FAX control board 70 does not exceed the specified current value.

[0031] For example, the threshold voltage is generated by dividing the voltage generated inside the lightning surge protection circuit 710 with a resistor. Also, for example, the value of the current flowing from the communication line to the lightning surge protection circuit 710, which is compared with the threshold voltage, is generated as a voltage by passing the current flowing through the lightning surge protection circuit 710 through a resistor.

[0032] In Figure 2, the CPU 701 initiates communication based on the detection of an off-hook by the off-hook detection circuit 711 and turns on the overcurrent protection function of the lightning surge protection circuit 710. As shown in Figure 2(a), when the threshold is at a standard value and normal operation is performed, the current value will be less than or equal to the specified current value, so it will not exceed the threshold, and the turned-on overcurrent protection function will not operate. The CPU 701 then continues communication and terminates the communication by turning on the hook.

[0033] On the other hand, in Figure 2(a), if an overcurrent exceeding a threshold (standard time) occurs after communication has started based on off-hook status, the overcurrent protection function of the lightning surge protection circuit 710 is activated. As a result, the value of the current flowing through the primary side communication circuit 707 becomes less than or equal to a specified current value, preventing damage to the circuits in the FAX control board 70. For example, the CPU 701 detects that the overcurrent protection function has been activated and forcibly turns on the device after a predetermined time, thereby forcibly terminating the communication.

[0034] As shown in Figure 2(b), if the threshold is lower than the specified current value, the current value will exceed the threshold when the CPU 701 starts communication. Then, the overcurrent protection function of the lightning surge protection circuit 710 will activate. As a result, the current flowing to the primary side communication circuit 707 via the lightning surge protection circuit 710 will decrease, making it difficult to perform normal communication. Note that the threshold may be lower due to manufacturing variations in the circuits mounted on the FAX control board 70, for example.

[0035] After this, the CPU 701 forcibly turns on after a predetermined time and terminates the communication, similar to when an overcurrent occurs when the threshold is at a standard value. In other words, there is a problem that if the threshold falls below a specified current value due to some factor, the overcurrent protection function of the lightning surge protection circuit 710 is turned on and the circuit is forcibly turned on. In this embodiment, this problem is solved by implementing the flow shown in Figure 4.

[0036] (Operation flow of the FAX control board) Figure 4 is a flowchart showing an example of the operation of the FAX control board 70 shown in Figure 2. For example, the operation shown in Figure 4 is realized by the CPU 701 of the FAX control board 70 executing a control program. Figure 4 shows an example of a control method and a control program for the image forming apparatus 100.

[0037] First, in step S10, the CPU 701 goes off-hook when it wants to start communication. Next, in step S12, the CPU 701 turns on the overcurrent protection function of the lightning surge protection circuit 710.

[0038] Next, in step S14, the CPU 701 determines whether the overcurrent protection function of the lightning surge protection circuit 710 has activated. If the CPU 701 determines that the overcurrent protection function has activated, it performs step S16; if it determines that the overcurrent protection function has not activated, it performs step S24.

[0039] In step S16, the CPU 701 observes the line current. For example, the line current is observed using an ammeter (not shown) provided in the FAX control board 70. Next, in step S18, the CPU 701 determines whether the observed line current value is greater than or equal to a threshold value. The threshold value used by the CPU 701 for the determination in step S18 is preferably the same as the standard threshold value shown in Figure 3, but it does not have to be the same as the standard threshold value shown in Figure 3. The CPU 701 that performs step S18 is an example of a determination unit.

[0040] If the line current value is above the threshold, the CPU 701 determines that the lightning surge protection circuit 710 has activated its overcurrent protection function based on the correct threshold (an overcurrent has occurred), and performs step S22. If the line current value is below the threshold, the CPU 701 determines that the lightning surge protection circuit 710 has malfunctioned based on a threshold that has shifted to the lower side, and has activated its overcurrent protection function (no overcurrent has occurred), and performs step S20.

[0041] In step S20, the CPU 701 resets the operation of the overcurrent protection function by the lightning surge protection circuit 710 by turning off the overcurrent protection function, and then returns to step S12. Meanwhile, in step S22, the CPU 701 notifies the display control unit 64 of the operation unit 60 in Figure 1 of the occurrence of an overcurrent, and then performs step S26.

[0042] In step S24, the CPU 701 determines whether communication has ended or not. If communication has ended, it performs step S26. If communication has not ended, it returns to step S14.

[0043] In step S26, the CPU 701 goes on-hook. Next, in step S28, the CPU 701 performs the communication termination process, turns off the overcurrent protection function, and terminates the operation shown in Figure 4. Through these operations, even if the lightning surge protection circuit 710 incorrectly detects an overcurrent due to a variation in the threshold used by the lightning surge protection circuit 710 to the lower side, the CPU 701 can prevent the display of an incorrect message on the operation panel 62 and prevent it from going on-hook.

[0044] (Message displayed when overcurrent is detected) Figure 5 shows an example of a message displayed on the operation panel 62 based on the notification to the operation unit 60 in step S22 of Figure 4. Figure 5(a) shows an example of a message prompting the user of the image forming apparatus 100 to review the connection of the communication line. The user who sees the message should review and reconnect the connection of the communication line, and if the same message is still displayed, contact the service center for the image forming apparatus 100.

[0045] Figure 5(b) shows an example of a message displayed when a service technician visiting to maintain the image forming apparatus 100 operates the control panel 62 to bring up the maintenance display screen. For example, the maintenance screen displays that the above location is "Fax" and the measured overcurrent level. Upon seeing the message, the service technician checks the connection of the communication line, estimates the location of the malfunction in the image forming apparatus 100 based on the overcurrent level value, and carries out repairs.

[0046] In this embodiment, even if the lightning surge protection circuit 710 incorrectly detects an overcurrent due to a deviation in the threshold value used by the lightning surge protection circuit 710, the CPU 701 can prevent the display of an incorrect message on the operation panel 62 and prevent the device from being on-hooked.

[0047] The user of the image forming apparatus 100 can review and reconnect the communication line based on the message displayed on the control panel 62. In the case of an overcurrent due to a misconnection, the user can be prompted to review or replace the connection at an early stage, preventing the image forming apparatus 100 from malfunctioning. This helps to prevent interference with the user's use of the line. If the same message is still displayed, the user can request repairs.

[0048] A service technician visiting for maintenance can check the connection of the communication line based on the overcurrent level displayed on the maintenance screen and estimate the location of the malfunction in the image forming apparatus 100. The service technician visiting for maintenance can check the overcurrent level at any time and check for malfunctions when they occur. In this way, if an overcurrent flows due to an error in the communication line connection, the fact that an overcurrent has flowed is displayed on the control panel 62, allowing the user and service technician to review the connection environment.

[0049] Although the present invention has been described above based on various embodiments, the present invention is not limited to the requirements shown in the above embodiments. These points can be modified as long as they do not impair the spirit of the present invention, and can be appropriately determined according to their application. [Explanation of symbols]

[0050] 10 Power supply unit 20 Engine control board 30 Scanners 40 Printers 50 Controller Control Board 60 Control section 62 Control Panel 64 Display Control Unit 70 FAX control board 72 Detection unit 74 Notification Department 100 Image forming apparatus 701 CPU 702 SRAM 703 FROM 704 DRAM 705 SiDAA (SSD) 706 SiDAA (LSD) 707 Primary side communication circuit 709 Speaker drive circuit 710 Lightning Surge Protection Circuit 711 Off-hook detection circuit 712 Sounding Circuit 713 Relay AC commercial power [Prior art documents] [Patent Documents]

[0051] [Patent Document 1] Japanese Patent Publication No. 2015-149606

Claims

1. An image forming unit that forms an image, An operating unit including a display unit, An overcurrent protection circuit that, when an overcurrent is detected from the communication line while in the ON state, activates a protection function to protect against overcurrent, and when in the OFF state, stops the overcurrent detection operation from the communication line. A transmitting and receiving unit that transmits and receives image data to the aforementioned communication line, When an overcurrent is detected by the overcurrent protection circuit, a determination unit determines whether the line current input from the communication line is above a threshold value, The system includes a notification unit that notifies the operation unit that the determination unit has determined that the line current is equal to or greater than the threshold value, and that causes the display unit to display a message indicating the occurrence of an overcurrent. An image forming apparatus characterized by the following.

2. The operation unit displays a message on the display unit prompting a review of the communication line connection based on a notification from the notification unit. The image forming apparatus according to claim 1, characterized by the following:

3. The operation unit, based on a notification from the notification unit, displays the overcurrent level when the display unit becomes a display screen operated by a service technician maintaining the image forming apparatus. The image forming apparatus according to claim 1, characterized by the following:

4. The image forming apparatus has a measurement unit that measures the voltage of the communication line when the power is started up and displays the measurement result on the display unit. An image forming apparatus according to any one of claims 1 to 3, characterized by the above.

5. A control method for an image forming apparatus having an image forming unit that forms an image, an operation unit including a display unit, and an overcurrent protection circuit that, when an overcurrent is detected from a communication line while the apparatus is ON, activates a protection function to protect against overcurrent, and when the apparatus is OFF, stops the overcurrent detection operation from the communication line, Image data is transmitted to and received from the aforementioned communication line. When an overcurrent is detected by the overcurrent protection circuit, it is determined whether the line current input from the communication line is above a threshold value. The operation unit is notified that it has been determined that the line current is above the threshold, and a message indicating the occurrence of an overcurrent is displayed on the display unit. A control method for an image forming apparatus characterized by the following.

6. A control program for an image forming apparatus having an image forming unit that forms an image, an operation unit including a display unit, and an overcurrent protection circuit that, when an overcurrent is detected from a communication line while the apparatus is ON, activates a protection function to protect against overcurrent, and when the apparatus is OFF, stops the overcurrent detection operation from the communication line. Image data is transmitted to and received from the aforementioned communication line. When an overcurrent is detected by the overcurrent protection circuit, it is determined whether the line current input from the communication line is above a threshold value. The operation unit is notified that it has been determined that the line current is above the threshold, and a message indicating the occurrence of an overcurrent is displayed on the display unit. A control program for an image forming apparatus characterized by the following.

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