IMAGE FORMING APPARATUS, FAULT SENSING METHOD, AND NON-TRANSITORY COMPUTER-READABLE RECORDING MEDIUM STORING FAULT SENSING PROGRAM

To inhibit toner bottle in which toner is remaining from being replaceable, image forming apparatus includes: bottle cover that can open/close insertion opening of toner bottle housing; locking mechanism to lock closed bottle cover; actuating mechanism including unlocking member to unlock locked bottle cover and open bottle cover, and actuator to actuate unlocking member; front cover situated in openable/closable manner in front of bottle cover to inhibit bottle cover from becoming open while front cover is closed; fault sensing unit to perform first fault sensing process in which actuator is sensed as having fault when failing to actuate unlocking member in spite of actuator being driven while image forming unit is non-operating; and condition sensing unit to sense presence of possibility that front cover is opened. Fault sensing unit is excluded from performing first fault sensing process while condition sensing unit is sensing the possibility as being present.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2023-077817, filed May 10, 2023, the contents of which are incorporated herein by reference in their entirety.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to an image forming apparatus, a fault sensing method, and a non-transitory computer-readable recording medium storing a fault sensing program.

Description of the Related Art

According to a technique of an image forming apparatus, a lockable bottle cover situated on an insertion opening of a toner bottle housing is allowed to unlock when the amount of a toner remaining in the toner bottle becomes zero, in order that toner bottle replacement in a state in which the toner is still remaining can be avoided. This type of an image forming apparatus includes a locking mechanism configured to lock the bottle cover on the insertion opening of the toner bottle housing, an unlocking mechanism configured to unlock the locked state, and a sensing mechanism configured to sense whether the bottle cover is open or closed. The locking mechanism controls unlocking by using a solenoid.

The image forming apparatus displays a message prompting the user to do a check on a display unit, in a case where the sensing mechanism indicates that the bottle cover remains closed even after being unlocked. In a case where the user replaced toner bottles after the message was displayed, the image forming apparatus determines that the sensing mechanism is having a fault. In a case where the user did not replace toner bottles, the image forming apparatus determines that the locking mechanism is having a fault (for example, see Japanese Unexamined Patent Application Publication No. 2020-190694).

SUMMARY OF THE INVENTION

An image forming apparatus according to an embodiment of the present disclosure includes: an image forming unit configured to form an image; a toner bottle housing configured to house a toner bottle in a withdrawably insertable manner, the toner bottle being filled with a toner used by the image forming unit to form an image; a bottle cover situated such that the bottle cover can open or close an insertion opening of the toner bottle housing; a locking mechanism configured to lock the bottle cover being in a closed state in which the bottle cover is at a position to cover the insertion opening; an actuating mechanism including an unlocking member and an actuator, the unlocking member being configured to unlock the bottle cover, being in a locked state, to bring the bottle cover into an open state in which the bottle cover does not cover the insertion opening, and the actuator being configured to actuate the unlocking member; a front cover situated in an openable/closable manner in front of the bottle cover and configured to inhibit the bottle cover from becoming open while the front cover is in a closed state; a fault sensing unit configured to perform a first fault sensing process in which the actuator is sensed as having a fault in a case where the actuator fails to actuate the unlocking member in spite of the actuator being driven while the image forming unit is non-operating; and a condition sensing unit configured to sense presence of a possibility that the front cover is going to be opened, wherein the fault sensing unit is excluded from performing the first fault sensing process while the condition sensing unit is sensing the possibility as being present.

DESCRIPTION OF THE EMBODIMENTS

For example, in a case of determining whether a locking mechanism is having a fault or not by unlocking a bottle cover in an image forming apparatus in which the locking mechanism is not having a fault, unlocking the bottle cover while a front cover is opened may put a toner bottle in which a toner is remaining in a risky state of being replaceable, because the bottle cover becomes open as a result of being unlocked.

In view of the issue described above, an object of the present disclosure is to inhibit a toner bottle in which a toner is remaining from being put in a replaceable state.

According to an embodiment of the present disclosure, it is possible to inhibit a toner bottle in which a toner is remaining from being put in a replaceable state.

An embodiment will be described below with reference to the drawings. The same components in the drawings will be denoted by the same reference numerals, and overlapping descriptions of the same components may be omitted.

FIG.1is an overall configuration view illustrating an example of an image forming apparatus according to an embodiment of the present disclosure. For example, an image forming apparatus100is a Multifunction Peripheral (MFP/Printer/Product) including a copier function, a FAX function, a print function, a scanner function, and the like. The image forming apparatus100may include a print function alone, or may include a print function together with any selected from a copier function, a FAX function, and a scanner function. An image to be processed by the image forming apparatus100may include not only image data including an image, but also text data free of an image.

The image forming apparatus100is a tandem-type electrophotographic image forming apparatus employing an intermediate transfer method. The image forming apparatus100includes an automatic document feeder110, an image reader120, an operation unit130, a paper tray140, an image forming unit150, a front cover160, and a paper feeding cassette170. The image forming apparatus100also includes a locking mechanism300, an actuating mechanism400, and an operation control unit500configured to control the entire operation of the image forming apparatus100. Practically, the operation control unit500is situated inside the body of the image forming apparatus100in the form of, for example, a control board.

The automatic document feeder110is configured to feed each single one of original document sheets separately into the image reader120. The image reader120is configured to generate image data by optically reading image information of each one of the original document sheets sent sequentially from the automatic document feeder110. The image reader120can also generate image data by optically reading an original document sheet placed on a transparent original document table.

The operation unit130includes an operation panel132configured to receive various inputs corresponding to operations of a user, and to display various information, and a human-presence sensor134configured to sense whether the user is present in front of the operation unit130or not.

Examples of information displayed on the operation panel132include information indicating an operation inputted and received, information indicating an operating status of the image forming apparatus100, information indicating the state of settings in the image forming apparatus100, and various alarms. Examples of various alarms include a “service call” display, which prompts asking a service hub of the image forming apparatus100for a repair in a case where the image forming apparatus100senses an abnormality of the internal mechanism.

For example, the operation panel132may include a Liquid Crystal Display (LCD) or an organic Electro-Luminescence (EL) display having a touch panel function. The operation panel132may further include hardware keys or the like in addition to the display having a touch panel function.

The human-presence sensor134is an infrared sensor, a camera, or the like. The human-presence sensor134is configured to sense whether the user is present in front of the image forming apparatus100or not. The human-presence sensor134outputs information indicating whether the user is present or not to the operation control unit500.

The image forming apparatus100may include an illuminance sensor or a timer instead of the human-presence sensor134. For example, the illuminance sensor is configured to output information indicating presence of a possibility that the user is present in front of the image forming apparatus100to the operation control unit500in a case where the environment in which the image forming apparatus100is installed (e.g., a room) is higher than or equal to a predetermined illuminance. The illuminance sensor outputs information indicating absence of the possibility that the user is present in front of the image forming apparatus100to the operation control unit500in a case where the installation environment is lower than the predetermined illuminance.

For example, the timer is configured to output information indicating presence of the possibility that the user is present in front of the image forming apparatus100to the operation control unit500at a previously set business start time. The timer outputs information indicating absence of the possibility that the user is present in front of the image forming apparatus100to the operation control unit500at a business end time. By performing a fault sensing process by controlling a solenoid410to be ON at a timing at which there is a low possibility of a human being present in front of the image forming apparatus100in accordance with the illuminance sensor or the timer, it is possible to perform fault sensing at a timing at which there is a low urgency for the recovery from a fault.

The image forming unit150includes a photoconductor drum, a charging device, a writing unit, a developing device, a conveying belt, a fixing device, and the like, which are non-illustrated. The image forming unit150is an example of an image forming unit. The charging device is configured to charge a circumferential surface of the photoconductor drum. The writing unit is configured to expose the charged photoconductor drum to light and write an electrostatic latent image on the photoconductor drum based on image data read by the image reader120.

The developing device is configured to develop the latent image written on the photoconductor drum with a toner. The conveying belt is configured to convey a sheet of paper, on which a toner image is to be formed, to the photoconductor drum, such that the toner image attached on the photoconductor drum through developing is transferred to the sheet of paper. The fixing device is configured to fix the toner image over the sheet of paper onto the sheet of paper, to form the toner image on the sheet of paper. The sheet of paper on which the toner image is formed is ejected onto the paper tray140.

The image forming unit150includes toner bottle housings152in which toner bottles10Y,10C,10M, and10K filled with, for example, yellow, cyan, magenta, and black toners respectively are housed. When describing the toner bottles10Y,10C,10M, and10K in the following description without distinguishing them, they may also be referred to as toner bottles10.

The image forming unit150includes bottle covers200attached such that they can open or close insertion openings152a(FIG.3) of the toner bottle housings152through which the toner bottles10are inserted, and open/close sensors210. The open/close sensors210are configured to sense whether the bottle covers200are open or closed.

The locking mechanism300is configured to lock the bottle cover200at a position at which the bottle cover200covers the insertion opening152a(FIG.3) through which the toner bottle10is inserted. The actuating mechanism400is configured to unlock the bottle cover200being locked by the locking mechanism300, to bring the bottle cover200into an open state. An example of the toner bottles10is illustrated inFIG.4. An example of the locking mechanism300is illustrated inFIG.3. An example of the operations of the locking mechanism300and the actuating mechanism400is illustrated inFIG.5.

FIG.1illustrates the bottle covers200, which are attached in front of the toner bottle housings152of the toner bottles10Y,10C, and10M, as being in a closed state. To facilitate understanding of the description, these toner bottle housings152are illustrated as if they were seen through. The bottle cover200attached in front of the toner bottle housing152of the toner bottle10K is illustrated as being in the open state, in which the toner bottle10K can be inserted into and withdrawn from the toner bottle housing152in the frontward/rearward direction of the image forming apparatus100. That is, the toner bottle10is replaceable in the state in which the bottle cover200is open.

The front cover160is attached in front of the image forming unit150, and can be opened or closed by the user and the like.FIG.1illustrates the front cover160as being in an open state, in which the bottle covers200are exposed. An open/close sensor162configured to sense whether the front cover160is open or closed is attached to the front cover160. The open/close sensor162is an example of an open/close sensing unit. The bottle covers200can become fully open in the state in which the front cover160is open. In a state in which the front cover160is closed, the bottle covers200are inhibited from becoming open. Hence, in a case where the front cover160is closed, the bottle covers200do not enter the open state merely by being unlocked from a locked state, and the open/close sensor210senses that the bottle covers200are in the closed state.

The operation control unit500is realized by a non-illustrated control board mounted with, for example, a controller such as a Central Processing Unit (CPU) and the like. The operation control unit500is configured to sense whether the bottle covers200are in the open state or the closed state based on information received from the open/close sensors210, and to sense whether the front cover160is in the open state or the closed state based on information received from the open/close sensor162. The operation control unit500may be realized by a System on Chip (SoC), a Field-Programmable Gate Array (FPGA), or the like.

For example, the operation control unit500controls the image forming apparatus100based on an operation received via the operation panel132, to perform a copying operation and the like. The operation control unit500may control the image forming apparatus100based on an instruction received from an external device such as a PC. The operation control unit500also performs a fault sensing process to sense whether the actuating mechanism400is having a fault, as will be described with reference toFIG.8andFIG.9.

The paper feeding cassette170accommodates sheets of paper and the like on which no toner image is formed yet. For example, the paper feeding cassette170can accommodate sheets of paper and the like that are varied in size.FIG.1illustrates an example in which two paper feeding cassettes170are situated in the image forming apparatus100. The number of paper feeding cassettes170may be one, or may be three or more.

FIG.2is a block diagram illustrating an example of the hardware configuration of the operation control unit500ofFIG.1. The operation control unit500includes a CPU510, a Read Only Memory (ROM)520, and a Random Access Memory (RAM)530. The operation control unit500also includes an input interface unit540, an output interface unit550, an input/output interface unit560, and a communication interface unit570.

For example, the CPU510, the ROM520, the RAM530, the input interface unit540, the output interface unit550, the input/output interface unit560, and the communication interface unit570are mutually connected through a bus BUS.

The CPU510is configured to execute various programs such as an Operating System (OS), applications, and the like. The ROM520is configured to retain basic programs and various parameters necessary for various programs to be executed by the CPU510. The RAM530is configured to store various programs executed by the CPU510, data used in the programs, and the like. For example, various programs may include an image processing program for performing image processing of original document images read by the image reader120, and a fault sensing program for sensing whether the actuating mechanism400is having a fault.

Input devices610such as the operation panel132, the human-presence sensor134, and the like are connected to the input interface unit540. Output devices620such as the display unit of the operation panel132, the image forming unit150, and the like are connected to the output interface unit550. Input/output devices630such as a Hard Disk Drive (HDD), a recording medium, and the like, which are non-illustrated, are connected to the input/output interface unit560.

In a case where various programs such as the image processing program, the fault sensing program, and the like are stored in recording media, the programs are transferred to the RAM530and the like from the recording media via the input/output interface unit560. The communication interface unit570can connect the operation control unit500to a network and the like, and can communicate with the service hub of the image forming apparatus100.

FIG.3is a partial oblique view illustrating an example of the bottle cover200situated on the toner bottle housing152ofFIG.1. For example, a frame154configured for the bottle cover200to be attached inside is secured in front of the toner bottle housing152. The frame154has a through-hole through which the toner bottle10can be inserted, at a position facing the insertion opening152aof the toner bottle housing152into which the toner bottle10(seeFIG.1) is inserted. A latch310included in the locking mechanism300, and the open/close sensor210are attached to the frame154. The latch310and the open/close sensor210are situated at diagonal positions of the rectangular frame154with respect to the insertion opening152a,although they are not particularly limited to this positioning.

The bottle cover200comes to a position to cover the insertion opening152awhen closed, and is secured to the frame154pivotally on a shaft member220. The bottle cover200includes a hook202on an edge portion of the bottle cover200on a side opposite to the shaft member220side, the hook202sticking out from the edge portion. The hook202is situated at a position to be engaged with the latch310when the bottle cover200is in the closed state in which the bottle cover200is at a position to cover the insertion opening152a.The latch310and the hook202are an example of the locking mechanism configured to lock the bottle cover200that is in the closed state. The detailed shapes of the latch310and the hook202and the method of engaging them will be described with reference toFIG.5.

FIG.4is a partial oblique view illustrating a state in which the toner bottles10are set in the four toner bottle housings152ofFIG.1, respectively.FIG.4omits the bottle covers200, butFIG.4corresponds to a state in which the bottle covers200become open as a result of being unlocked from the locking mechanism. When loading the image forming apparatus100with a toner, the toner bottle10(10Y,10M,10C, or10K) is inserted into the toner bottle housing152along the direction of the arrow.

The toner bottle10has an approximately cylindrical shape, and is rotatably held relative to a cap that is non-rotatably held on the toner bottle housing152, although the toner bottle10is not particularly limited to this configuration. The toner bottle10put into the toner bottle housing152is moved in the direction of the arrow ofFIG.4while being rotated.

In response to an end of the toner bottle10being fitted in a cap receptacle12, the toner bottle10becomes connected to a toner tank via a non-illustrated toner supply device that is situated at the rear side of the cap receptacle12. The toner filled in the toner bottle10is appropriately stored in the toner tank.

For example, in a case where a non-illustrated toner remaining amount sensing unit senses that the toner in the toner bottle10has become lower than or equal to a predetermined amount, information indicating “no toner” is displayed on the screen of the operation panel132. When the user, having seen the screen, presses a “confirm” button on the operation panel132and opens the front cover160, the open/close sensor162senses that the front cover160has entered the open state, causing the solenoid410to be actuated and the bottle cover200to be opened. Hence, the toner bottle10housed in the position corresponding to the opened bottle cover200becomes removable and replaceable with a new toner bottle10.

FIG.5is a drawing illustrating an example of a locked state and an unlocked state of the bottle cover200ofFIG.3. The locking mechanism300illustrated inFIG.1includes the latch310, a shaft member320, a helical torsion spring330, a link340, and a coil spring350. The actuating mechanism400illustrated inFIG.1includes the solenoid410, a control line420, and a bottle cover control unit430. The solenoid410is an example of the unlocking member configured to bring the bottle cover200into an open state not covering the insertion opening152a(FIG.3). Any component (e.g., a transistor Q1ofFIG.6) of the bottle cover control unit430that is involved in actuating the solenoid410is an example of the actuator configured to actuate the solenoid410.

The latch310has an L-letter shape, and is pivotally supported on the shaft member320situated at the flexural portion of the L-letter. The helical torsion spring330, which is configured to bias one end of the L-letter-shaped latch310in a direction A toward the bottle cover200side, is situated around the shaft member320.

A recess312having a shape conforming to the shape of the hook202of the bottle cover200is formed in a portion of the latch310on the biased one end side. The hook202being engaged with the recess312of the latch310is restricted from moving with respect to the frame154, keeping the bottle cover200in the closed state.

The internal side of the other end of the latch310contacts the internal side of one end side of the link340having an acute-angled-U-letter shape. The other end side of the link340is joined to a rod412of the solenoid410. The coil spring350configured to bias the link340in a direction B toward the latch310side is attached to the link340. The solenoid410is connected to the bottle cover control unit430through the control line420, and is actuated by the bottle cover control unit430.

While the solenoid410is not actuated by the bottle cover control unit430in the state (a) illustrated inFIG.5, the rod412can freely move. Here, the latch310pivots in the direction A due to the flexural stress in the helical torsion spring330, causing the hook202to be engaged with the recess312. The link340, which is under the biasing force from the coil spring350, moves in the direction B while keeping in contact with the end of the latch310, following the pivoting of the latch310. Hence, the bottle cover200is locked within the frame154in a state of covering the insertion opening152a(FIG.3) for the toner bottle10.

In response to being actuated by the bottle cover control unit430in the state (b) illustrated inFIG.5, the solenoid410retracts the rod412in the direction C. This causes the link340to move in the direction C, to push the other end of the latch310in the direction C, to cause the latch310to pivot in the direction D by resisting the flexural stress in the helical torsion spring330. The hook202is disengaged from the recess312, to cause the bottle cover200to be unlocked from the frame154.

In the state of being unlocked from the frame154, the bottle cover200is structured to pivot in a direction in which the hook202is separated from the frame154due to the gravitational force, a spring force, or the like. Hence, after the state (b), the bottle cover200automatically becomes open. In the case ofFIG.1in which the front cover160is opened, the bottle cover200becomes fully open, and it is possible to insert or withdraw the toner bottle10into or from the insertion opening152a(FIG.3). The open/close sensor210(FIG.3) senses that the bottle cover200has become open.

The bottle cover control unit430stops actuating the solenoid410after the bottle cover200has become open. Hence, the link340and the latch310return to the positions illustrated in the state (a). In response to the bottle cover200being closed by the user with the toner bottle10replaced, the one end of the latch310is pushed by the hook202. The latch310pivots in the direction D illustrated in the state (b) by resisting the flexural stress in the helical torsion spring330until the hook202is engaged in the recess312. Then, the bottle cover200is locked within the frame154again as illustrated in the state (a) ofFIG.5.

FIG.6is a block diagram illustrating an example of the functions of the CPU510ofFIG.2and the bottle cover control unit430ofFIG.5. The CPU510includes a condition sensing unit512and a fault sensing unit514. For example, the condition sensing unit512and the fault sensing unit514may be realized by the fault sensing program executed by the CPU510.

The condition sensing unit512is configured to receive information indicating whether the user is present in front of the image forming apparatus100or not from the human-presence sensor134, to determine presence or absence of a possibility that the front cover160is going to be opened. The condition sensing unit512is also configured to receive information indicating whether the front cover160is in the open state or the closed state from the open/close sensor162, and to receive information indicating an operating status of the image forming unit150, the operating status being generated in the CPU510, as information indicating whether printing is being performed or not.

The condition sensing unit512determines whether or not to perform sensing of whether the actuating mechanism400is having a fault based on the possibility that the front cover160is going to be opened, whether the front cover160is in the open state or the closed state, and whether printing is being performed or not, and informs the result of the determination to the fault sensing unit514. An example of determination performed by the condition sensing unit512is illustrated inFIG.7.

In a case of receiving an instruction to perform sensing of whether the actuating mechanism400is having a fault from the condition sensing unit512, the fault sensing unit514performs a fault sensing process to sense whether the actuating mechanism400is having a fault based on information received from the bottle cover control unit430.

For example, in a case of sensing an open circuit fault of the solenoid410or an open circuit fault of the transistor Q1through the fault sensing process, the fault sensing unit514may display an error message indicating occurrence of the fault and a service call prompting asking for a repair on the display unit of the operation panel132. The fault sensing unit514may inform the occurrence of the fault to the service hub of the image forming apparatus100or the like via the communication interface unit570. In this case, the fault sensing unit514may display a message indicating that the occurrence of the fault has been informed to the service hub or the like on the display unit of the operation panel132. An example of the operation of the fault sensing unit514is illustrated inFIG.8andFIG.9.

The bottle cover control unit430includes a solenoid control unit431, the transistor Q1, a diode D1, resistors R1, R2, R3, and R4, a capacitor C1, and a connector CN1. The solenoid control unit431includes a general-purpose output port GPO configured to control the gate voltage of the transistor Q1and a general-purpose input port GPI configured to receive a fault detection signal FDET, and can exchange information with the CPU510.

For example, the solenoid control unit431may be realized by a microcomputer mounted on the bottle cover control unit430. In the following description, the general-purpose output port GPO and the general-purpose input port GPI are referred to as the output port GPO and the input port GPI, respectively. The output port GPO is connected to the gate of the transistor Q1via the resistor R1. The gate of the transistor Q1is connected (pulled down) to a ground line GND via the resistor R2.

The source of the transistor Q1is connected to the ground line GND. The drain of the transistor Q1is connected to the anode of the diode D1, and is connected to a power source line V24via the diode D1. The drain of the transistor Q1is also connected to one end of the solenoid410via the connector CN1. The other end of the solenoid410is connected to the power source line V24.

The drain of the transistor Q1is also connected to the ground line GND via the resistors R3and R4connected in series. A voltage level, which is a divided voltage of the drain voltage of the transistor Q1, is generated at a connection node ND1between the resistors R3and R4as the fault detection signal FDET. The connection node ND1is connected to the ground line GND via the capacitor C1.

In a case of receiving an instruction to control the solenoid410to be ON to open the bottle cover200from the CPU510, the solenoid control unit431outputs a voltage for turning ON the transistor Q1to the gate of the transistor Q1from the output port GPO. In a case of receiving an instruction to not control the solenoid410to be ON from the CPU510, the solenoid control unit431outputs a voltage for turning OFF the transistor Q1to the gate of the transistor Q1from the output port GPO.

While the solenoid410is controlled to be OFF, the solenoid control unit431can sense whether the solenoid410is having a winding breakage fault, a fault due to harness detachment from the connector CN1, or a harness breakage fault. In the following description, a solenoid410's winding breakage fault, a fault due to harness detachment from the connector CN1, and a harness breakage fault may also be referred to collectively as solenoid open circuit faults. In the following description, a fault will be described as being a single fault.

While the solenoid410is controlled to be OFF, the transistor Q1is turned OFF. Hence, in a case where the solenoid410and the harness connected to the connector CN1are normal (in a case where no solenoid open circuit fault is occurring), the connection node ND1is at a divided voltage resulting from the power source voltage V24being divided in accordance with the resistors R3and R4, and the fault detection signal FDET is set to a high level.

On the other hand, in a case where a solenoid open circuit fault is occurring, the connection node ND1is at the ground voltage GND because of the resistor R3not being connected to the power source line V24, and the fault detection signal FDET is set to a low level. Hence, in a case where the fault detection signal FDET is at the low level while the solenoid410is controlled to be OFF, the solenoid control unit431can sense a solenoid open circuit fault.

While the solenoid410is controlled to be ON, the solenoid control unit431can sense whether the transistor Q1is having an open circuit fault. In the following description, the open circuit fault of the transistor Q1is also referred to as a transistor open circuit fault. While the solenoid410is controlled to be ON, the solenoid control unit431attempts to turn ON the transistor Q1. In a case where the transistor Q1is normal, the transistor Q1becomes turned ON, the connection node ND1becomes set to the ground voltage GND, and the fault detection signal FDET becomes set to the low level.

On the other hand, in a case where the transistor Q1is having an open circuit fault, the connection node ND1is at a divided voltage resulting from the power source voltage V24being divided in accordance with the resistors R3and R4, and the fault detection signal FDET is set to the high level. Hence, in a case where the fault detection signal FDET is at the high level while the solenoid410is controlled to be ON, the solenoid control unit431can sense a transistor open circuit fault.

In a case where the transistor Q1is normal, sensing of whether the transistor Q1is having a transistor open circuit fault causes the bottle cover200to be unlocked and become open at an unintentional timing, because the solenoid410is being controlled to be ON. In a case where the bottle cover200becomes open at an unintentional timing while the user is present in front of the image forming apparatus100, the user may suspect a fault of the image forming apparatus100.

For example, the user present in front of the image forming apparatus100is always able to open the front cover160. In a case where the user opens the front cover160concurrently with a transistor open circuit fault being sensed, the bottle cover200may open just in front of the user. Hence, it is preferable that sensing of any transistor open circuit fault is not performed in a case where the user is present in front of the image forming apparatus100.

A solenoid open circuit fault and a transistor open circuit fault may be sensed by the fault sensing unit514. In this case, the solenoid control unit431outputs the logic level of the fault detection signal FDET received at the input port GPI to the CPU510.

FIG.7is a diagram illustrating an example of a determining process according to which the condition sensing unit512ofFIG.6determines whether or not to perform fault sensing for an ON control period of the solenoid410and for an OFF control period of the solenoid410. Fault sensing for an ON control period of the solenoid410is an example of the first fault sensing process. Fault sensing for an OFF control period of the solenoid410is an example of a second fault sensing process. The fault sensing for an ON control period of the solenoid410and for an OFF control period of the solenoid410is performed repeatedly at a predetermined cycle.

In a case where the image forming unit150is not performing a printing operation and the front cover160is closed, the condition sensing unit512determines whether or not to perform the fault sensing for an ON control period of the solenoid410in accordance with a human sensing status of the human-presence sensor134. In a case where the human-presence sensor134is sensing no human presence in front of the image forming apparatus100, the condition sensing unit512determines to perform the fault sensing for an ON control period of the solenoid410. In this case, the condition sensing unit512outputs an instruction to control the transistor Q1to be ON to the bottle cover control unit430at a timing for the fault sensing for an ON control period of the solenoid410.

On the other hand, in a case where the human-presence sensor134is sensing presence of a human in front of the image forming apparatus100, the condition sensing unit512determines to not perform the fault sensing for an ON control period of the solenoid410. In this case, the condition sensing unit512does not output an instruction to control the transistor Q1to be ON to the bottle cover control unit430even when a timing for the fault sensing for an ON control period of the solenoid410has come. Hence, it is possible to inhibit the bottle cover200from becoming open due to the fault sensing while a human is present in front of the image forming apparatus100.

In a case where the image forming unit150is not performing a printing operation and the front cover160is open, the condition sensing unit512determines to not perform the fault sensing for an ON control period of the solenoid410irrespective of a human sensing status of the human-presence sensor134. In this case, the condition sensing unit512does not output an instruction to control the transistor Q1to be ON to the bottle cover control unit430even when a timing for the fault sensing for an ON control period of the solenoid410has come.

Hence, it is possible to inhibit the bottle cover200from becoming open due to the fault sensing while the front cover160is open, and to inhibit a toner bottle10in which a toner is remaining from being put in a replaceable state. As a result, it is possible to inhibit a toner that is ready to be used for printing from being discarded wastefully. Moreover, it is possible to avoid the user suspecting a fault and the like of the image forming apparatus100even though no fault is occurring.

Moreover, in a case where the image forming unit150is performing a printing operation, the fault sensing for an ON control period of the solenoid410is determined to be performed irrespective of whether the front cover160is in the open state or the closed state and the human sensing status of the human-presence sensor134. Because there are no chances of the front cover160being opened during a printing operation, it is possible to perform the fault sensing for an ON control period of the solenoid410even when the user is present in front of the image forming apparatus100.

The fault sensing for an OFF control period of the solenoid410is constantly performed irrespective of the printing status, whether the front cover160is in the open state or the closed state, and a human sensing status of the human-presence sensor134. That is, when a timing for the fault sensing for an OFF control period of the solenoid410has come, an instruction to control the transistor Q1to be OFF is output to the bottle cover control unit430. Hence, it is possible to separate a plurality of causes of faults from each other before a repair. As a result, it is possible to quicken the repair and shorten the downtime in the event of a fault of the image forming apparatus100.

FIG.8andFIG.9are flowcharts illustrating an example of a process according to which the CPU510ofFIG.6senses a fault of the solenoid410, the transistor Q1, and the like. That is,FIG.8andFIG.9illustrate an example of the fault sensing method for the image forming apparatus100.FIG.8andFIG.9also illustrate an example of the fault sensing program executed by the CPU510. The process illustrated inFIG.8andFIG.9is performed repeatedly at a predetermined cycle.

First, in the step S10, the CPU510outputs an instruction to the bottle cover control unit430to output a low level L from the output port GPO to turn OFF the transistor Q1. Next, in the step S12, the CPU510receives from the bottle cover control unit430, the level of the fault detection signal FDET received at the input port GPI. Next, in the step S14, the CPU510moves the flow to the step S16in a case where the fault detection signal FDET is the high level H, and moves the flow to the step S24in a case where the fault detection signal FDET is the low level L.

In the step S24, the CPU510senses that the solenoid is having a solenoid open circuit fault (a solenoid410's winding breakage fault, a fault due to harness detachment from the connector CN1, or a harness breakage fault). Because the process for sensing a solenoid open circuit fault involves no user's operation, it is possible to inhibit the cause of a fault from being misidentified due to a user's operation mistake, and to shorten the downtime. After the process of the step S24, the CPU510moves the flow to the step S38ofFIG.9. In the step S16, the CPU510senses that the solenoid410and the connector CN1are normal (not having a fault).

Next, in the step S18, the CPU510determines whether printing is being performed or not based on a result of determination performed by the condition sensing unit512, and moves the flow to the step S28ofFIG.9in a case where printing is being performed and moves the flow to the step S20in a case where printing is not being performed.

In the step S20, the CPU510determines whether the front cover160is open or not based on a result of determination performed by the condition sensing unit512, and moves the flow to the step S26ofFIG.9in a case where it is open and moves the flow to the step S22in a case where it is closed.

In the step S22, the CPU510determines whether a human is present in front of the image forming apparatus100or not based on a result of determination performed by the condition sensing unit512, and moves the flow to the step S26ofFIG.9in a case where a human is present and moves the flow to the step S28ofFIG.9in a case where no human is present.

In the step S26ofFIG.9, the CPU510determines whether a period of time in which the process for sensing an open circuit fault of the transistor Q1is not performed is longer than or equal to a predetermined period of time or not. The CPU510moves the flow to the step S38in a case where the process for sensing an open circuit fault of the transistor Q1has not been performed for the predetermined period or longer. The CPU510ends the process illustrated inFIG.8andFIG.9in a case where the predetermined period has not elapsed since the process for sensing an open circuit fault of the transistor Q1has been performed.

In the step S28, the CPU510outputs an instruction to the bottle cover control unit430to output the high level H from the output port GPO to turn ON the transistor Q1. Next, in the step S30, the CPU510receives from the bottle cover control unit430, the level of the fault detection signal FDET received at the input port GPI. Next, in the step S32, the CPU510moves the flow to the step S34in a case where the fault detection signal FDET is the low level L, and moves the flow to the step S36in a case where the fault detection signal FDET is the high level H.

In the step S34, the CPU510senses that the transistor Q1is normal (having no fault), and ends the process illustrated inFIG.8andFIG.9. In the step S36, the CPU510senses that the transistor Q1is having an open circuit fault, and moves the flow to the step S38. Because the process for sensing an open circuit fault of the transistor Q1involves no user's operation, it is possible to inhibit the cause of a fault from being misidentified due to a user's operation mistake, and to shorten the downtime.

In the step S38, the CPU510reports occurrence of the fault and the like to the service hub or the like via the communication interface unit570, and ends the process illustrated inFIG.8andFIG.9. By reporting occurrence of a fault to the service hub or the like in response to an open circuit fault of the transistor Q1or a solenoid open circuit fault being sensed, it is possible to quicken a repair of the image forming apparatus100and further shorten the downtime.

By reporting to the service hub or the like that the process for sensing an open circuit fault of the transistor Q1has not been performed for the predetermined period or longer when this is the case, it is possible to prompt, for example, a maintenance worker to perform a fault sensing work at a regular maintenance visit or the like, and to find a fault early. In a case where the step S38is performed, the operation of the image forming apparatus100is stopped. Hence, the process illustrated inFIG.8andFIG.9is not repeated.

According to the present embodiment, it is possible to sense whether the transistor Q1is having an open circuit fault by controlling the solenoid410to be ON at a timing at which no human is present in front of the image forming apparatus100in accordance with the human-presence sensor134, the illuminance sensor, or the timer. The process for sensing an open circuit fault of the transistor Q1by controlling the solenoid410to be ON is not performed while the front cover160is open. Hence, it is possible to inhibit the bottle cover200from becoming open due to the fault sensing being performed while the front cover160is open, and to inhibit a toner bottle10in which a toner is remaining from being put in a replaceable state. As a result, it is possible to inhibit a toner that is ready to be used for printing from being discarded wastefully.

By controlling the solenoid410to be OFF, it is possible to sense whether there is a solenoid open circuit fault (a solenoid410's winding breakage fault, a fault due to harness detachment from the connector CN1, or a harness breakage fault). Because it is possible to separate a plurality of causes of faults from each other before a repair, it is possible to quicken the repair and shorten the downtime in the event of the image forming apparatus100having a fault.

Moreover, it is possible to sense a plurality of fault modes such as an open circuit fault of the transistor Q1, a solenoid410's winding breakage fault, and the like without prompting a user's operation via the operation panel132. Because no user's operation is involved, it is possible to inhibit the cause of a fault from being misidentified due to a user's operation mistake. As a result, it is possible to further shorten the downtime.

By performing the fault sensing process by controlling the solenoid410to be ON at a timing at which there is a low possibility of a human being present in front of the image forming apparatus100in accordance with the illuminance sensor or the timer, it is possible to perform fault sensing at a timing at which there is a low urgency for the recovery from a fault. By performing the fault sensing for an ON control period of the solenoid410during a printing operation being performed during which there are no chances of the front cover160being opened, it is possible to perform fault sensing even while the user is present in front of the image forming apparatus100.

By reporting occurrence of a fault to the service hub or the like in response to an open circuit fault of the transistor Q1or a solenoid open circuit fault being sensed, it is possible to quicken a repair of the image forming apparatus100and further shorten the downtime.

By reporting to the service hub or the like that the process for sensing an open circuit fault of the transistor Q1has not been performed for the predetermined period or longer when this is the case, it is possible to prompt, for example, a maintenance worker to perform a fault sensing work at a regular maintenance visit or the like, and to find a fault early.

An image forming apparatus, including:an image forming unit configured to form an image;a toner bottle housing configured to house a toner bottle in a withdrawably insertable manner, the toner bottle being filled with a toner used by the image forming unit to form an image;a bottle cover situated such that the bottle cover can open or close an insertion opening of the toner bottle housing;a locking mechanism configured to lock the bottle cover being in a closed state in which the bottle cover is at a position to cover the insertion opening;an actuating mechanism including an unlocking member configured to unlock the bottle cover, being in a locked state, to bring the bottle cover into an open state in which the bottle cover does not cover the insertion opening, and an actuator configured to actuate the unlocking member;a front cover situated in an openable/closable manner in front of the bottle cover and configured to inhibit the bottle cover from becoming open while the front cover is in a closed state;a fault sensing unit configured to perform a first fault sensing process in which the actuator is sensed as having a fault in a case where the actuator fails to actuate the unlocking member in spite of the actuator being driven while the image forming unit is non-operating; anda condition sensing unit configured to sense presence of a possibility that the front cover is going to be opened,wherein the fault sensing unit is excluded from performing the first fault sensing process while the condition sensing unit is sensing the possibility as being present.
<2>

The image forming apparatus according to <1>,wherein the fault sensing unit performs a second fault sensing process irrespective of whether the condition sensing unit is sensing the possibility as being present or not, the second fault sensing process being a process in which the unlocking member is sensed as having a fault in a case where an operating state of the unlocking member while the unlocking member is being unactuated by the actuator represents anything other than a state of being unactuated by the actuator.
<3>

The image forming apparatus according to <1> or <2>, further includingan open/close sensing unit configured to sense whether the front cover is in an open state or the closed state,wherein in a case where the open/close sensing unit is sensing that the front cover is in the open state, the fault sensing unit is excluded from performing the first fault sensing process irrespective of whether the condition sensing unit is sensing the possibility as being present or not.
<4>

The image forming apparatus according to any one of <1> to <3>,wherein the condition sensing unit senses the possibility as being present in a case of sensing that a user is present in front of the front cover.
<5>

The image forming apparatus according to any one of <1> to <3>,wherein the condition sensing unit senses the possibility as being present in a time slot in which there is a possibility that a user is present in front of the front cover based on a timer or an illuminance of an environment in which the image forming apparatus is installed.
<6>

The image forming apparatus according to any one of <1> to <5>,wherein while the image forming unit is operating, the fault sensing unit performs the first fault sensing process irrespective of whether the condition sensing unit is sensing the possibility as being present or not.
<7>

The image forming apparatus according to any one of <1> to <6>,wherein in a case of sensing a fault of the actuator, the fault sensing unit reports the fault to an external entity of the image forming apparatus.
<8>

The image forming apparatus according to any one of <1> to <7>,wherein in a case of failing to perform the first fault sensing process even once in a predetermined period of time, the fault sensing unit reports a failure to perform the first fault sensing process to an external entity of the image forming apparatus.
<9>

A fault sensing method for an image forming apparatus, the image forming apparatus includingan image forming unit configured to form an image,a toner bottle housing configured to house a toner bottle in a withdrawably insertable manner, the toner bottle being filled with a toner used by the image forming unit to form an image,a bottle cover situated such that the bottle cover can open or close an insertion opening of the toner bottle housing,a locking mechanism configured to lock the bottle cover being in a closed state in which the bottle cover is at a position to cover the insertion opening,an actuating mechanism including an unlocking member configured to unlock the bottle cover, being in a locked state, to bring the bottle cover into an open state in which the bottle cover does not cover the insertion opening, and an actuator configured to actuate the unlocking member, anda front cover situated in an openable/closable manner in front of the bottle cover and configured to inhibit the bottle cover from becoming open while the front cover is in a closed state,the fault sensing method including:performing a first fault sensing process in which the actuator is sensed as having a fault in a case where the actuator fails to actuate the unlocking member in spite of the actuator being driven while the image forming unit is non-operating; andsensing presence of a possibility that the front cover is going to be opened,wherein the first fault sensing process is excluded from being performed while the possibility is sensed as being present in the sensing of presence of the possibility.
<10>

A non-transitory computer-readable recording medium storing a fault sensing program for an image forming apparatus, the image forming apparatus includingan image forming unit configured to form an image,a toner bottle housing configured to house a toner bottle in a withdrawably insertable manner, the toner bottle being filled with a toner used by the image forming unit to form an image,a bottle cover situated such that the bottle cover can open or close an insertion opening of the toner bottle housing,a locking mechanism configured to lock the bottle cover being in a closed state in which the bottle cover is at a position to cover the insertion opening,an actuating mechanism including an unlocking member configured to unlock the bottle cover, being in a locked state, to bring the bottle cover into an open state in which the bottle cover does not cover the insertion opening, and an actuator configured to actuate the unlocking member, anda front cover situated in an openable/closable manner in front of the bottle cover and configured to inhibit the bottle cover from becoming open while the front cover is in a closed state,wherein when executed by a computer, the fault sensing program causes the computer to:perform a first fault sensing process in which the actuator is sensed as having a fault in a case where the actuator fails to actuate the unlocking member in spite of the actuator being driven while the image forming unit is non-operating; andsense presence of a possibility that the front cover is going to be opened,wherein the first fault sensing process is excluded from being performed while the possibility is sensed as being present in the sensing of presence of the possibility.

The present disclosure has been described above based on the embodiment. However, the present disclosure is not limited to the requirements specified in the embodiment described above. The specified particulars can be changed as long as the spirit of the present disclosure is not spoiled, and can be defined appropriately to suit to the mode of application of the present disclosure.