Image forming apparatus having developer accommodating container rotation detection

An image forming apparatus includes a developing device configured to develop an electrostatic latent image formed on an image bearing member, a rotatable developer accommodating container dismountably mounted in the image forming apparatus and configured to accommodate a developer, and a mounting portion including a receiving portion for receiving the developer discharged from the container and configured to mount the container. A cover is configured to open and close the mounting portion, and a rotation detecting portion is configured to detect rotation of the container mounted at the mounting portion. In addition, a display portion displays information, and a controller controls the display portion so that information on the rotation of the container is displayed at the display portion in a case that when the cover is open, with the rotation detecting portion detecting a predetermined amount of the rotation of the container.

FIELD OF THE INVENTION AND RELATED ART

The present invention relates to an image forming apparatus including a developer accommodating container for accommodating toner supplied to a developing device.

Conventionally, in the image forming apparatus, when an amount of a developer in the developing device is decreased by image formation, the developer is supplied from the developer accommodating container to the developing device through a developer feeding path (Japanese Laid-Open Patent Application 2017-90708). When an amount of the developer in the developing device is a predetermined amount or less, the developer in the developer feeding path is supplied to the developing device by rotating a screw in the developer feeding path. Thereafter, the developer accommodating container is rotated by a motor, so that the developer is supplied from the developer accommodating container to the developing device. By controlling rotation of the developer accommodating container driven by the motor, the developer in a stable amount can be supplied from the developer accommodating container to the developing device.

However, when a user dismounts the developer accommodating container or when the user unnecessarily rotates the mounted developer accommodating container, supply of the developer in a state in which there is no need to supply the developer is caused.

SUMMARY OF THE INVENTION

A principal object of the present invention is to provide an image forming apparatus capable of reducing a degree of unnecessary supply of a developer due to unnecessary rotation of a developer accommodating container by a user.

According to an aspect of the present invention, there is provided an image forming apparatus comprising: a developing device configured to develop an electrostatic latent image formed on an image bearing member; a rotatable developer accommodating container dismountably mounted in the image forming apparatus and configured to accommodate a developer; a mounting portion including a receiving portion for receiving the developer discharged from the developer accommodating container and configured to mount the developer accommodating container; a cover configured to open and close the mounting portion; a rotation detecting portion configured to detect rotation of the developer accommodating container mounted at the mounting portion; a display portion configured to display information; and a controller configured to control the display portion so that information on the rotation of the developer accommodating container is displayed at the display portion in a case that when the cover is open, the rotation detecting portion detects a predetermined amount of the rotation of the developer accommodating container.

DESCRIPTION OF EMBODIMENTS

With reference to the drawings, embodiments for carrying out the present invention will be described. Incidentally, the following embodiments should not be construed as limiting the present invention thereto. Further, all combinations of structures described in the embodiments also should not be construed restrictively as being essential constituent elements of the present invention.

FIG. 1is a sectional view of an image forming apparatus100. In this embodiment, the image forming apparatus100will be described by citing a printing apparatus (printer) for forming an image on a sheet by using an electrophotographic process, as an example. However, the image forming apparatus100is not limited to the printing apparatus but may also be, for example, a copying machine, a multi-function peripheral (MFP) or a facsimile machine. Incidentally, the multi-function peripheral is an image forming apparatus having at least two functions of a plurality of functions including a printing (print) function, a scanning function, a copying function and a facsimile function. The sheet is a recording medium on which the image is to be formed using the electrophotographic process, and is paper, an OHP sheet, a cloth or the like, for example. The sheet may also be referred to as recording paper, a recording material, the recording medium, a form, a transfer(-receiving) material, transfer(-receiving) paper or the like.

The image forming apparatus100may also be a color image forming apparatus for forming a color image with toners, as a developer, of a plurality of colors, but in this embodiment, the image forming apparatus100for forming a monochromatic image with monochromatic (single color) toner will be described. The image forming apparatus100includes a sheet feeding portion10, an image forming portion20, a fixing portion30and a sheet discharging portion40provided in a named order from a lower side (an upstream side with respect to a sheet feeding direction) toward an upper side (a downstream side with respect to the sheet feeding direction) inFIG. 1. Further, on a right side of the image forming portion20and the fixing portion30, a sheet re-feeding portion50is provided. A CPU400as a controller controls operations of respective portions of the image forming apparatus100in order to form the image on the sheet.

The sheet feeding portion10feeds a sheet P, stacked in a cassette11or on a tray16, toward the image forming portion20. A sensor S1detects the sheet P stacked in the cassette11. The CPU400discriminates, on the basis of a detection result of the sensor S1, whether or not the sheet P is accommodated in the cassette11. The sheet P accommodated in the cassette11is fed to a separation roller pair13by rotation of a pick-up roller12. In the case where multi-feeding (double feeding) of the sheets P is caused, two or more sheets are separated one by one by the separation roller pair13consisting of a normal rotation roller13aand a reverse rotation roller13b. The sheet P separated by the separation roller pair13is fed to a feeding path PS1indicated by a solid line. The sheet P fed to the feeding path PS1is further fed by a feeding roller pair14. Then, oblique movement of the sheet P is corrected by causing a leading end of the sheet P to follow a nip of a registration roller pair15which stops rotation thereof.

In the case where the sheet P is fed from the tray16, the sheets P are separated one by one by a feeding roller17and a separation pad18. The separated sheet P is fed toward the feeding roller pair14by a conveying roller pair19. Oblique movement of the sheet P is corrected by the registration roller pair15. The sheet P of which oblique movement is corrected is fed toward the image forming portion20by the registration roller pair15which starts rotation thereof at predetermined timing. A sensor S2detects timing when the leading end of the sheet reaches the nip of the registration roller pair15.

In the image forming portion20, a photosensitive drum21as a photosensitive member is rotated in a direction indicated by an arrow. A surface of the photosensitive drum21is electrically charged by a charging roller22. A laser scanner23emits laser light, toward the charged surface of the photosensitive drum21, modulated in accordance with image data sent from an external portion. At a portion of the surface of the photosensitive drum21irradiated with the laser light, electric charges given by the charging roller22are removed, whereby an electrostatic latent image is formed on the surface of the photosensitive drum21in accordance with the image data. A developing roller24of a developing device26develops the electrostatic latent image with a developer (hereinafter referred to as toner) and visualizes the electrostatic latent image into a toner image. The developing device26includes a developer accommodating container302for accommodating the toner (hereinafter, this container302is referred to as a toner bottle) and a developing device (portion)309as a developing container in which the developing roller24is provided. The toner bottle302supplies the toner to the developing device309as needed. The developing device26will be described later.

The photosensitive drum21forms a transfer nip N1in contact with a transfer roller25. The toner image on the photosensitive drum21is fed toward the transfer nip N1by rotation of the photosensitive drum21. In synchronism with this timing, the sheet P is fed from the registration roller pair15toward the transfer nip N1. The toner image is transferred from the photosensitive drum21onto the sheet P by the transfer roller25while the sheet P is nipped and fed through the transfer nip N1by the photosensitive drum21and the transfer roller25. The sheet P on which the toner image is transferred is fed toward the fixing portion30

The fixing portion30includes a fixing roller31and a pressing roller32. The fixing roller31is an aluminum roller in which a halogen lamp31aas a heat source is provided. The halogen lamp31aheats the fixing roller31to a predetermined fixing temperature. The pressing roller32contacts the fixing roller31with a predetermined pressure and forms a fixing nip N2therebetween. The sheet P on which the toner image is transferred is heated and pressed by being nipped and fed through the fixing nip N2by the fixing roller31and the pressing roller32, so that the toner image is fixed on the sheet P and thus an image is formed on the sheet P. A sensor S3detects that a trailing end of the sheet P has passed through the fixing nip N2. Incidentally, a heating type of the fixing portion30may also be an on-demand fixing type in which a ceramic heater as the heat source and an endless film are used, in place of a heating roller type in which the sheet P is heated by the fixing roller31. In the on-demand fixing type, the pressing roller32presses the endless film toward the ceramic heater and forms the fixing nip N2between itself and the endless film. The sheet P on which the toner image is transferred is heated and pressed by being nipped and fed through the fixing nip N2by the endless film and the pressing roller32, so that the toner image is fixed on the sheet P and thus an image is formed on the sheet P.

The sheet P on which the image is formed is fed to the sheet discharging portion40, where the sheet P is discharged onto a tray42by a discharging roller pair41. In the case where images are formed on both sides (surfaces) of the sheet P, the discharging roller pair41is once stopped after the trailing end of the sheet P on which the image is formed at a first surface passes through the sensor S3and before the trailing end of the sheet P passes through the discharging roller pair41. Then, the discharging roller pair41is reversely rotated, whereby the sheet P is fed toward the sheet re-feeding portion50. The sheet P fed to the sheet re-feeding portion50is fed along a feeding path PS2, indicated by a broken line, by a re-feeding roller pair51and52and then is fed toward the registration roller pair15by a re-feeding roller pair53. The sheet P is subjected to correction of oblique movement thereof by the registration roller pair15, and thereafter is fed to the transfer nip N1, so that the toner image is transferred onto a second surface of the sheet P. Then, similarly as in image formation on the first surface of the sheet P, the toner image is fixed on the second surface of the sheet P by feeding the sheet P through the fixing nip N2. The sheet P on which the images are formed at the first and second surfaces thereof is discharged onto the tray42by the discharging roller pair41.

FIG. 2is a schematic view showing a structure of the developing device26. The toner bottle302is constituted so as to be mountable in and dismountable from a main assembly101of the image forming apparatus100. The toner bottle302is dismountably (removably) mounted in the main assembly101of the image forming apparatus100. A toner cover300is provided on the main assembly101of the image forming apparatus100so as to be openable and closable relative to the main assembly101. The toner cover300is opened when the toner bottle302is mounted in the main assembly101. A user has access to the toner bottle302by opening the toner cover300. In the case where the toner in the toner bottle302is used up by the image formation, the user opens the toner cover300and then exchanges the toner bottle302with a new one. As a result, the image formation is successively carried out. A toner cover sensor (cover developer)301detects opening and closing of the toner cover301. A toner supplying portion150includes the toner bottle302, a bottle motor (first driving means)304and a toner feeding path306. The toner feeding path306is provided between the toner bottle302and the developing device309and is provided with an inlet321through which the toner discharged from the toner bottle302is received and an outlet322through which the toner is discharged to the developing device309.

The toner bottle302is connected with the bottle motor304via a driving gear train311. By rotation of the bottle motor304, the toner bottle302is rotated in an arrow A direction. The toner bottle302is rotated by the bottle motor304, whereby the toner is detection sequenced from an inside of the toner bottle302. The toner discharged from the toner bottle302flows into the toner feeding path306. The toner supplying portion150is provided with a home position sensor (hereinafter referred to as an HP sensor)303. The HP sensor303is a rotation detector for detecting a reference position (home position) of the rotation of the toner bottle302. A detection result of the HP sensor303is also used for detecting a rotational speed of the toner bottle302. Together with the HP sensor303, a rotation detector for detecting the rotational speed of the toner bottle302on the basis of a rotation detection signal outputted from the bottle motor304may also be provided.

In the toner feeding path306, a screw312as a toner feeding means for feeding the toner, received through the inlet321, toward the outlet322is provided. The screw312is connected with a feeding path motor305via a driving gear train313. A rotational driving force is transmitted from the feeding path motor305to the screw312via the driving gar train313. The screw312is driven and rotated by the feeding path motor305and feeds the toner, caused to flow into the toner feeding path306from the toner bottle302, in an arrow B direction. The toner fed through the toner feeding path306is discharged to the developing device309at an end portion of the toner feeding path306. The toner supplying portion150is provided with a feeding path toner sensor307. The feeding path toner sensor307detects the toner in the toner feeding path306. In the case where the feeding path toner sensor307does not detect the toner in the toner feeding path306even when the toner bottle302is rotated, the CPU400discriminates that the toner bottle302is empty.

The developing device309is provided with a screw314. The screw314is connected with a developing motor308via a driving gear train315. A rotational driving force is transmitted from the developing motor308to the screw314via the driving gear train315. The toner in the developing device309is stirred by the screw314rotated by the developing motor308and is stably supplied to the developing roller24. The developing device309is provided with a developing device toner sensor310for detecting an amount of the toner in the developing device309.

FIG. 3is a block diagram showing a constitution of a control system600for controlling the developing device26. The control system600includes the CPU400, a system controller408and a display panel (operating portion)409. The CPU400as the control means includes a ROM401, a RAM402and an EEPROM403. In the ROM401, a control program for controlling an entirety of the image forming apparatus100is stored. The RAM402is a volatile storing device not only used as an operational area of the CPU400but also used for temporarily storing various data such as the image data. The EEPROM403is a non-volatile storing device and stores various data such as a remaining toner amount in the developing device309. The CPU400reads the control program stored in the ROM401and reads the control program into the RAM402, and then executes the control program, so that the CPU400controls an entirety of the image forming apparatus100. The CPU400is electrically connected with a toner cover opening and closing detecting portion317, the toner supplying portion150and the developing device309of the developing device26.

The CPU400controls an operation of the toner supplying portion150by controlling operations of the bottle motor304and the feeding path motor305. Into the CPU400, a signal outputted from the feeding path toner sensor307of the toner supplying portion150and a signal outputted from the developing device toner sensor310of the developing device309are inputted. The CPU400controls the supply of the toner from the toner supplying portion150toward the developing device309, on the basis of the signals outputted from the feeding path toner sensor307and the developing device toner sensor310.

In the case where an output signal from the feeding path toner sensor307indicates that there is no toner in the toner feeding path306, the CPU400drives the bottle motor304, so that the toner is supplied from the toner bottle302into the toner feeding path306. The CPU400controls the bottle motor304every time when toner in the toner feeding path306is empty as detected using the feeding path toner sensor307, so that the toner bottle302is rotated. Further, on the basis of an output signal from the developing device toner sensor310, the CPU400discriminates whether or not the amount of the toner in the developing device309is smaller than a predetermined amount. In the case where the CPU400discriminated that the toner amount in the developing device309is smaller than the predetermined amount, the CPU400drives the feeding path motor305and thus the screw312is rotated, so that the toner is supplied from the toner feeding path306toward the developing device309. The CPU400controls the feeding path motor305every time when the toner amount in the developing device309detected using the developing device toner sensor310is smaller than the predetermined amount, so that the screw312is rotated.

The feeding path toner sensor307outputs an ON-state signal when it detects the toner in the toner feeding path306and outputs an OFF-state signal when it does not detect the toner in the toner feeding path306. The CPU400monitors the output signal from the feeding path toner sensor307at a predetermined time interval and discriminates the presence or absence of the toner in the toner feeding path306on the basis of the output signal from the feeding path toner sensor307. For example, in the case where the output signal from the feeding path toner sensor307is the OFF-state signal continuously for predetermined times, the CPU discriminates that there is no toner in the toner feeding path306.

The developing device toner sensor310outputs an ON-state signal in the case where an amount of the toner in the developing device309is larger than a predetermined amount and outputs an OFF-state signal in the case where the toner amount in the developing device309is smaller than the predetermined amount. The CPU400monitors the output signal from the developing device toner sensor310at a predetermined time interval and discriminates the presence or absence of the toner in the developing device309on the basis of the output signal from the developing device toner sensor310. For example, in the case where the output signal from the developing device toner sensor310is the OFF-state signal continuously for predetermined times, the CPU may also discriminate that the toner amount in the developing device309is smaller than the predetermined amount.

In a case other than the case where the CPU400controls the bottle motor304and thus rotates the toner bottle302with the result that the toner is supplied to the toner feeding path306(i.e., toner feeding control), the toner is unintentionally supplied from the toner bottle302toward the toner feeding path306by an external force in some instances. In such a case, there is a possibility that the toner feeding path306is clogged with the toner due to excessive supply of the toner and that the toner overflows the toner feeding path306and thus an inside of the image forming apparatus100is contaminated with the toner. Therefore, the CPU400detects that the toner bottle302is rotated by a force other than a driving force of the bottle motor304, and prevents clogging of the toner feeding path306with the toner and contamination of the inside of the image forming apparatus100with the toner.

<Toner Bottle Hand Rotation Detection Control>

In the following, toner bottle hand rotation detection control for detecting rotation of the toner bottle302by hand(s) of a user will be described. First, with reference toFIG. 4, a main assembly control operation for controlling the image forming apparatus100will be described.FIG. 4is a flowchart showing a process in the main assembly control operation of the image forming apparatus100. The CPU400reads a program, stored in the ROM401, in the RAM402and then executes the main assembly control operation.

When a main switch of the image forming apparatus100is turned on (S501), the CPU400executes an actuation process such as register setting and jam (paper jam) detection, or the like process (S502). When the actuation process is completed, the CPU400causes the image forming apparatus100to go to a stand-by mode (state) (S503). In the stand-by mode, the image forming apparatus100is in an image formable state in which the image forming apparatus100awaits a print job start instruction so that a printing operation can be immediately started upon receipt of the print job start instruction from the display panel409or an external device. The CPU400causes the image forming apparatus100to go to a hand rotation detection sequence from the stand-by mode (S504). The hand rotation detection sequence will be described later. When the CPU400receives the print job start instruction, the CPU400causes the image forming apparatus100to start the printing operation (S505). When the printing operation is ended, the CPU400causes the image forming apparatus100to perform a post-rotation process such as cleaning (S506). Then, the CPU400causes the image forming apparatus100to go to the stand-by mode again (S507). The CPU400discriminates whether or not the main switch is turned off (S508). In the case where the main switch is not turned off (NO of S508), the CPU400causes the image forming apparatus100to go to the hand rotation detection sequence from the stand-by mode (S504). In the case where the main switch is turned off (YES of S508), the CPU400causes the image forming apparatus100to end the main assembly control operation.

Next, with reference toFIG. 5, the hand rotation detection sequence in S504ofFIG. 4will be described.FIG. 5is a flowchart showing the hand rotation detection sequence. During the stand-by mode, the CPU400causes the image forming apparatus100to perform the hand rotation detection sequence for detecting the rotation of the toner bottle302by the hand(s) of the user.

When the hand rotation detection sequence is started, the CPU400discriminates whether or not the toner cover300is opened, on the basis of a detection result of the toner cover sensor301(S601). In the case where the toner cover300is not opened (NO of S601), the CPU400causes the image forming apparatus100to end the hand rotation detection sequence. In the case where the toner cover300is opened (YES of S601), the CPU400starts polling of the HP sensor303in order to detect the rotation of the toner bottle302(S602). The CPU400discriminates whether or not the toner bottle302is rotated, on the basis of a detection result of the HP sensor303(S603). In the case where the toner bottle302is not rotated (NO of S603), the CPU400returns the process (sequence) to S601. In the case where the toner bottle302is rotated (YES of S603), on the basis of the detection result of the HP sensor303, the CPU400counts the number of rotations (turns) of the toner bottle302(S604). The CPU400has a function as a counting means for counting the number of rotations of the toner bottle302in a period in which the toner cover300is open. When the toner bottle302is rotated, the toner in the toner bottle302is discharged from the toner bottle302into the toner feeding path306. The CPU400drives the feeding path motor305, so that the screw312is rotated (S605). By rotation of the screw312, the toner in the toner feeding path306is discharged into the developing device309. As a result, the clogging of the toner feeding path306with the toner is prevented.

The CPU400discriminates whether or not a count value M of the number of rotations of the toner bottle302is larger than a first predetermined value (threshold) (S606). In this embodiment, the first predetermined value is set at 3. However, the first predetermined value is not limited to 3 but may also be another numerical value. The count value M of the number of rotations of the toner bottle302represents the number of times of rotation of the toner bottle302by the hand(s) of the user when the user opens the toner cover300in the stand-by mode. In the case where the count value M is 3 or less (NO of S606), the CPU400returns the process to S601. In the case where the count value M is larger than 3 (YES of S606), the CPU400drives the developing motor308, so that the screw314is rotated (S607). By rotation of the screw (stirring means)314, the toner in the developing device309is stirred, so that clogging of an inlet316of the developing device309with the toner discharged from the toner feeding path306to the developing device309is prevented.

The CPU400detects whether or not the toner bottle302is further rotated by the hand(s) of the user. Specifically, the CPU400discriminates whether or not the count value M of the number of rotations of the toner bottle302is larger than a second predetermined value (threshold) (S608). In this embodiment, the first predetermined value is set at 5. However, the first predetermined value is not limited to 5 but may also be another numerical value. The second predetermined value is larger than the first predetermined value. In the case where the count value M is 5 or less (NO of S608), the CPU400returns the process to S601. In the case where the count value M is larger than 5 (YES of S608), the CPU400causes the display panel409as a display portion to display a message thereon such that “DO NOT ROTATE THE TONER BOTTLE” (S609). By this message, the user is prompted to refrain from rotating the toner bottle302by the hand(s) of the user.

The CPU400discriminates whether or not the print job (start instruction) is received (S610). In the case where the print job is not received (NO of S610), the CPU400returns the process to S601. In the case where the print job is received (YES of S610), the CPU400resets the count value M to zero (S611). This is because when the printing operation is started, the toner in the developing device309is consumed and the toner amount in the developing device309is returned to a proper amount. Then, the CPU400ends the hand rotation detection sequence.

In the case where the toner bottle302is rotated by an external force such as the hand(s) of the user when the image formation is not carried out, the toner feeding path306is clogged with the toner discharged from the toner bottle302or the inside of the image forming apparatus100is contaminated with the leaked toner. Therefore, according to this embodiment, when the toner cover300is opened during the stand-by mode in which the image formation is not carried out, whether or not the toner bottle302is rotated is detected. When the rotation of the toner bottle302is detected, the screw312is rotated by driving the feeding path motor305, so that the toner in the toner feeding path306is discharged to the developing device309. As a result, the clogging of the toner feeding path306with the toner is prevented. When further rotation of the toner bottle302is detected, the screw314is rotated by driving the developing motor308, so that the toner in the developing device309is stirred. As a result, clogging of the inlet316of the developing device309with the toner is prevented. When further rotation of the toner bottle302is detected, a message for prompting the user to refrain from rotating the toner bottle302is displayed on the display panel409.

Incidentally, in this embodiment, as a user operation detecting means, an example in which the operation by the user is detected in the case where the toner cover sensor301detects that the toner cover300opens and the HP sensor303detects the rotation of the toner bottle302was described, but the present invention is not limited thereto. For example, the operation by the user may also be detected by detection of the rotation of the toner bottle302by the HP sensor303when there is no rotation signal to the bottle motor304. Further, from the toner bottle302, some toner can be discharged even by an insertion and extraction operation of the toner bottle302. Accordingly, in the case where the insertion and extraction operation of the toner bottle302by the user is detected by the HP sensor303and repetition of this detection in a short time such as about 10 seconds is detected, the insertion and extraction operation may also be detected as an operation in which the toner is discharged in an amount more than an allowable amount. Further, as a notifying means, the display panel was described, but the notifying means may also be an error sound. Further, even by only control or notification of the control of a downstream unit, an effect can be obtained.

According to the present invention, the image forming apparatus100is capable of reducing a degree of unnecessary supply of the developer due to unnecessary rotation of the developer accommodating container by the user.

This application claims the benefit of Japanese Patent Applications Nos. 2018-013306 filed on Jan. 30, 2018 and 2019-002471 filed on Jan. 10, 2019, which are hereby incorporated by reference herein in their entirety.