JP2015102582A - Developer conveyance mechanism, image forming apparatus, and developer conveyance failure detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a failure, such as toner clogging, without increasing cost, in developer conveyance, thereby preventing destruction of a conveyance member.SOLUTION: In a printer 1, a developer conveyance mechanism of a toner conveyance section 10 includes: a rotatable conveyance member 40 which conveys toner rearward along an axial direction; and a driving section 36 which drives rotation of the conveyance member 40. The developer conveyance mechanism includes: a biasing member 41 having a biasing force smaller than a minimum destruction torque of the conveyance member 40, to bias the conveyance member 40 rearward; and a detection section 42 which detects the conveyance member 40 moving forward opposite the conveyance direction. When the detection section 42 detects the conveyance member 40 moving forward against the biasing force of the biasing member 41, the driving section 36 is stopped.

Description

  The present invention relates to a developer transport mechanism that transports a developer used for image formation, an image forming apparatus including the developer transport mechanism, and a developer transport abnormality detection method.

  The image forming apparatus forms a toner image on the photosensitive drum by developing the electrostatic latent image formed on the photosensitive drum with toner (developer). The developing device is connected to a toner container that contains toner, and if the amount of toner in the developing device is insufficient, the toner is supplied from the toner container. In addition, a toner transport unit may be provided between the toner container and the developing device in order to adjust the amount of toner supplied to the developing device. In order to supply toner from the toner container to the developing device, it is necessary to provide a toner conveying mechanism (developer conveying mechanism) including a conveying screw or the like in the toner conveying portion, the toner container, and the developing device.

  In the toner transport mechanism, abnormalities such as toner clogging and toner fixation may occur due to nonuse for a long time. In the toner transport mechanism in which such an abnormality has occurred, a load is applied to the transport screw by toner that is difficult to transport. Therefore, if this load exceeds the breaking torque of the transport screw, the transport screw and its supporting parts are destroyed, that is, the toner transport mechanism. The mechanism may be destroyed. In addition, when the toner transport mechanism is destroyed, the destroyed parts and toner may be scattered to contaminate the image forming apparatus or cause other parts to fail. For this reason, the toner transport mechanism needs to be configured to avoid destruction caused by abnormalities such as toner clogging and toner adhesion.

  For example, in the waste toner collection container described in Patent Document 1, the waste toner collected by the cleaning device is provided in the collection container main body where the waste toner collected from the cleaning device is retained, and the collection container main body includes Conveying means for conveying the introduced waste toner in the horizontal direction and conveying along the longitudinal direction in the collection container main body, and an abnormality detecting means for detecting breakage of the conveying means (conveying screw) are provided.

  In the image forming apparatus described in Patent Document 2, a driving source, a driven member that is driven by a driving force from the driving source, and a driving force limit that limits the driving force transmitted from the driving source to the driven member. Means. Then, when the driving force is rotational torque and the driven member is rotated, a torque limiter is used as the driving force limiting means.

JP 2009-008820 A JP 2008-242389 A

  However, in the configuration in which the toner conveying mechanism is provided with the abnormality detecting means for detecting breakage of the conveying screw as described above, it is impossible to prevent the conveying screw from being broken, that is, the toner conveying mechanism from being broken. Therefore, it is necessary to replace the broken conveying screw and supporting parts, and to clean the parts and toner that have been scattered due to the destruction of the toner conveying mechanism, and there is a concern about an increase in cost and work load.

  Further, in the configuration in which the toner transport mechanism includes a torque limiter that limits the rotational torque, there is a concern that the cost increases because the torque limiter is expensive. Even if this torque limiter is provided, an increase in drive torque in the drive source cannot be avoided, and the possibility that the drive source and its control circuit will fail increases.

  Furthermore, if toner clogging or toner sticking occurs in the toner transport mechanism and the rotation of the transport screw is hindered, the motor that drives the transport screw will be locked, causing an overcurrent to flow through the motor and its control circuit, causing a malfunction. There is.

  In view of the above circumstances, an object of the present invention is to detect abnormalities such as toner clogging and prevent destruction of the conveying member without increasing the cost in conveying the developer.

  The developer transport mechanism of the present invention includes a rotatable transport member that transports the developer in the transport direction along the axial direction, a drive unit that drives rotation of the transport member, and a minimum breaking torque of the transport member. An urging member having an urging force smaller than a value, and urging the conveying member in the conveying direction, and a detection unit detecting movement of the conveying member in a direction opposite to the conveying direction. It is characterized by that.

  By adopting such a configuration, even when an abnormality such as toner clogging occurs in the developer transport mechanism, the transport member is moved in the axial direction before the load applied to the transport member by the driving force of the drive unit reaches the breaking torque. Therefore, the developer conveyance abnormality can be detected. In addition, the developer transport mechanism can detect abnormality in developer transport using low-cost components such as an urging member and a detection unit. That is, the developer transport mechanism of the present invention can detect an abnormality such as toner clogging and prevent breakage of the transport member without increasing the cost in developer transport.

  In the developer conveyance mechanism, the driving unit may be stopped when the detection unit detects movement of the conveyance member in the reverse direction against the urging force of the urging member.

  By adopting such a configuration, when the conveying member moves in the reverse direction, the driving unit stops. Therefore, when there is an abnormality in the developer conveyance, the developer conveyance can be stopped without destroying the conveyance member, that is, without destroying the developer conveyance mechanism, and the destruction of the conveyance member is ensured. To prevent.

  Alternatively, in the developer transport mechanism, when the detection unit detects the movement of the transport member in the reverse direction against the biasing force of the biasing member, the driving force of the drive unit is reduced, and then If the detection unit detects the movement of the transport member in the reverse direction, the drive unit may be stopped.

  By adopting such a configuration, if the conveying member rotates again by reducing the driving force of the driving unit, the conveying member moves in the conveying direction by the urging force of the urging member and shifts to a normal operation. Therefore, it is possible to avoid unnecessary stopping of the drive unit due to temporary toner clogging or the like.

  Even if an abnormality such as toner clogging occurs, the developer transport mechanism described above does not destroy the parts of the developer transport mechanism such as the transport member and its supporting parts, so the parts and developer of the developer transport mechanism are scattered. Rather, the developer can be reused by cleaning the developer conveyance path. In addition, when an abnormality such as toner clogging occurs, the drive unit is stopped, so that it is possible to prevent a failure due to an overcurrent flowing through the drive unit or its control circuit.

  In the developer transport mechanism, the drive unit includes a drive gear that transmits a driving force to the transport member, and the transport member includes a shaft gear having a shape longer than the drive gear in the axial direction. It is preferable that the shaft gear is provided with a plurality of teeth in the circumferential direction of the transport member and is slidably engaged with the drive gear in the axial direction.

  By adopting such a configuration, the transport member can be slid in the direction opposite to the transport direction without the shaft gear being disengaged from the drive gear.

  Further, in the developer transport mechanism, the detection unit includes a light emitting unit and a light receiving unit that are opposed to each other around the opposite side of the transport member, and the transport member is arranged in a radial direction from the transport member. The detected portion having an area larger than the cross-sectional area of the optical path between the light emitting portion and the light receiving portion at the spaced position is provided at the end on the reverse direction side, and the detected member is attached to the transport member by the attachment member. When moving in the reverse direction against the urging force of the urging member, it is preferable to move in the reverse direction according to the transport member and enter between the light emitting unit and the light receiving unit.

  By adopting such a configuration, the detection unit can be configured by using an optical sensor including a light emitting unit and a light receiving unit, so that it is possible to detect an abnormality in developer conveyance with a simple and inexpensive configuration. be able to.

  In the developer transport mechanism, the detection unit is disposed at a position spaced apart from the transport member in the radial direction and on the opposite side of the transport member, and detects contact from the transport direction side. The transport member includes a detected portion facing the detection portion at a position spaced apart from the transport member in the radial direction at an end on the reverse direction side, and the detected portion When the member moves in the reverse direction against the urging force of the urging member, the member may move in the reverse direction according to the transport member and contact the detection unit.

  By adopting such a configuration, the developer transport mechanism can be configured using various contact-type detection units. Therefore, development is performed with an appropriate configuration for each device to which the developer transport mechanism is applied. Abnormal detection of the agent conveyance can be realized.

  The image forming apparatus of the present invention is characterized in that any one of the developer transport mechanisms described above is provided in a developer container.

  The image forming apparatus of the present invention includes any one of the developer transport mechanisms described above in a developing device.

  The image forming apparatus of the present invention includes any one of the developer transport mechanisms described above in a developer transport unit that transports the developer from a developer container to a developing device.

  The developer conveyance abnormality detection method of the present invention is driven in a state where the conveyance member is urged in the conveyance direction along the axial direction by an urging member having an urging force smaller than the minimum value of the breaking torque of the conveyance member. The biasing member by a step of rotating the transport member by a driving force of the section to transport the developer in the transport direction, and a detection unit for detecting movement of the transport member in a direction opposite to the transport direction. And a step of detecting that there is an abnormality in the transport of the developer when detecting the movement of the transport member in the reverse direction against the urging force.

  In the developer conveyance abnormality detection method, the drive unit may be stopped when it is detected that the developer conveyance is abnormal.

  Alternatively, in the developer conveyance abnormality detection method, when it is detected that there is an abnormality in the developer conveyance, the driving force of the drive unit is reduced, and then the detection unit is in the reverse direction of the conveyance member. If the movement to is detected, the drive unit may be stopped.

  According to the present invention, it is possible to prevent the conveyance member from being broken by detecting an abnormality such as toner clogging without increasing the cost in the developer conveyance.

1 is a schematic diagram illustrating an outline of a printer according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a toner container in a printer according to an embodiment of the invention. FIG. 2 is a cross-sectional view illustrating a developing device in a printer according to an embodiment of the invention. FIG. 4 is a cross-sectional view illustrating a toner transport unit in which a transport member is in a normal position in the printer according to the embodiment of the present disclosure. FIG. 3 is a perspective view partially showing the inside of a toner conveyance unit in a printer according to an embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a toner transport unit in which a transport member has moved forward in the printer according to the embodiment of the present disclosure. 6 is a flowchart illustrating an operation of a toner transport unit in a printer according to an embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a toner conveyance unit in a printer according to another embodiment of the present invention.

  First, the overall configuration of a printer 1 as an image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic diagram showing an outline of a printer according to an embodiment of the present invention. 1 is the front side (front side) of the printer 1, and the arrow Fr in each figure indicates the front side of the printer 1.

  As shown in FIG. 1, the printer 1 includes a box-shaped printer main body 2, and a paper feed cassette 3 that stores paper (not shown) is stored in the lower portion of the printer main body 2. A paper discharge tray 4 is provided on the upper surface.

  An exposure unit 5 composed of a laser scanning unit (LSU) is disposed at the front of the printer main body 2, and an image forming unit 6 is provided at the rear of the printer main body 2. The image forming unit 6 is rotatably provided with a photosensitive drum 7 that is an image carrier. Around the photosensitive drum 7, a charger 8 and a toner container (developer container) 9 are provided with a toner transport unit ( A developing device 11, a transfer roller 12, and a cleaning device 13 connected via a (developer conveying unit) 10 are arranged along the rotation direction of the photosensitive drum 7 (see arrow X in FIG. 1). . The toner container 9 contains a developer (a one-component developer composed only of toner or a two-component developer composed of toner and carrier. Hereinafter, simply referred to as “toner”). In this embodiment, the developer transport mechanism of the present invention is provided in the toner transport unit.

  A paper transport path 14 is provided at the rear of the printer main body 2 from below to above. In the transport path 14, a paper feeding unit 15 is provided at the upstream end, a transfer unit 16 including the photosensitive drum 7 and the transfer roller 12 is provided in the midstream part, and a fixing unit 17 is provided in the downstream part. It is done. A reverse path 18 for duplex printing is provided behind the transport path 14.

  Next, an image forming operation of the printer 1 having such a configuration will be described.

  When the printer 1 is turned on, various parameters are initialized, and initial setting such as temperature setting of the fixing unit 17 is executed. Then, when image data is input from a computer or the like connected to the printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  First, after the surface of the photosensitive drum 7 is charged by the charger 8, exposure corresponding to image data is performed on the photosensitive drum 7 by laser light from the exposure device 5 (see arrow P in FIG. 1). Then, an electrostatic latent image is formed on the surface of the photosensitive drum 7. Next, the developing device 11 develops the electrostatic latent image on the photosensitive drum 7 into a toner image by the toner supplied from the toner container 9 to the developing device 11 via the toner conveying unit 10.

  On the other hand, the sheet taken out from the sheet cassette 3 by the sheet feeding unit 15 is conveyed to the transfer unit 16 in synchronization with the above-described image forming operation, and the toner image on the photosensitive drum 7 is transferred to the sheet by the transfer unit 16. Is transferred to. The sheet onto which the toner image has been transferred is conveyed downstream in the conveyance path 14 and enters the fixing unit 17 where the toner image is fixed on the sheet. The sheet on which the toner image is fixed is discharged from the downstream end of the transport path 14 to the discharge tray 4. The toner remaining on the photosensitive drum 7 is collected by the cleaning device 13.

  Next, the toner container 9 will be described with reference to FIG. FIG. 2 is a cross-sectional view of the toner container in the printer according to the embodiment of the present invention.

  For example, the toner container 9 is detachably attached to the printer main body 2. As shown in FIG. 2, the toner container 9 includes a container body 20 and a lid 21 that covers the upper surface of the container body 20.

  The container body 20 is formed in a substantially box shape having a shape that is long in the left-right direction and having an upper surface opened. A main body side flange portion 22 is provided on the outer periphery of the upper end of the container main body 20, and the main body side flange portion 22 is coupled to a lid body side flange portion 23 provided on the lid body 21, thereby opening the upper surface of the container main body 20. The part is blocked. A toner discharge portion 24 is opened at the rear of the lower surface of the container main body 20, and the inside of the container main body 20 communicates with the toner transport portion 10 via the toner discharge portion 24.

  A stirring member 25 such as a stirring paddle having a shape that is long in the left-right direction is rotatably provided inside the container body 20. Further, inside the container body 20, a conveying member 26 such as a conveying screw is provided behind the stirring member 25 so as to be rotatable in the vicinity of the toner discharge portion 24.

  Next, the developing device 11 will be described in detail with reference to FIG. FIG. 3 is a cross-sectional view of the developing device in the printer according to the embodiment of the present invention.

  As shown in FIG. 3, the developing device 11 includes a substantially box-shaped developing device main body 27, and an opening 28 is provided in the rear upper part of the developing device main body 27. The developing device 11 is disposed so that the opening 28 faces the photosensitive drum 7 (see FIG. 1). A toner introduction port 29 is opened at the upper front part of the developing device main body 27, and the inside of the developing device main body 27 communicates with the toner conveying unit 10 through the toner introduction port 29.

  Further, the developing device 11 includes a partition wall 30, a pair of stirring members 31 and 32, a developing roller 33, and a toner sensor 34 inside the developing device main body 27. The partition wall 30 is formed to have a shape that is long in the left-right direction so as to partition the front and rear at the approximate center of the bottom of the developing device main body 27. The agitating members 31 and 32 are, for example, agitating screws having a shape that is long in the left-right direction, and are arranged rotatably around the partition wall 30 at the bottom of the developing device main body 27, respectively. The developing roller 33 has a shape that is long in the left-right direction, and is rotatably arranged so as to face the photosensitive drum 7 in the rear upper part of the rear agitating member 32. The toner introduced from the toner container 9 (see FIG. 1) is stirred by the stirring members 31 and 32 and then supplied to the photosensitive drum 7 by the developing roller 33. The toner sensor 34 is provided on the inner wall surface of the developing device main body 27 and detects whether or not there is a sufficient amount of toner in the developing device main body 27.

  Next, the developer transport mechanism of the toner transport unit 10 will be described in detail with reference to FIGS. FIG. 4 is a cross-sectional view of the toner transport unit in which the transport member is in a normal position in the printer according to the embodiment of the present invention. FIG. 5 is a perspective view of the inside of the toner conveying unit in the printer according to the embodiment of the present invention. FIG. 6 is a cross-sectional view of the toner transport unit in which the transport member has moved forward in the printer according to an embodiment of the present invention.

  As shown in FIGS. 4 and 6, the toner transport unit 10 includes a box-shaped housing 35 having a shape that is long in the front-rear direction, and a drive unit 36 for driving a transport member 40 described later. Yes.

  In the housing 35, a toner introduction port 37 is opened at the front portion of the upper surface, and a toner discharge port 38 is opened at the rear portion of the lower surface. The toner introduction port 37 and the toner discharge port 38 of the housing 35 are connected to the toner discharge port 24 of the toner container 9 and the toner introduction port 29 of the developing device 11, respectively. Further, an insertion port 39 for inserting a later-described transport shaft 43 is provided on the rear end surface of the housing 35. A bearing (not shown) that pivotally supports the conveyance shaft 43 is provided at the front portion of the insertion port 39 and the housing 35, and the conveyance shaft 43 is in the circumferential direction (see arrow Y in FIGS. 4 and 6). And can be moved in the axial direction.

  Inside the housing 35, a conveying member 40, an urging member 41, and a detection unit 42 are provided.

  The conveying member 40 is a conveying screw or the like having a long shape in the front-rear direction (axial direction), and is rotatably mounted in the toner conveying unit 10 so as to convey the toner with the rearward conveying direction along the axial direction. Configured. The transport member 40 includes a transport shaft 43 that is elongated in the axial direction, and transport fins 44 that are provided around the transport shaft 43. The conveying member 40 is attached to the housing 35 such that the rear portion of the conveying shaft 43 protrudes outside the housing 35 through the insertion port 39. The transport fins 44 are arranged from the toner introduction port 37 to the toner discharge port 38 of the housing 35 and have a spiral shape so that the toner introduced from the toner introduction port 37 can be conveyed to the toner discharge port 38.

  Further, in the transport member 40, the detected portion 45 is provided at the front end of the transport shaft 43, and the shaft gear 46 is provided at the rear end.

  The detected part 45 is configured to have a larger area than the optical path cross-sectional area of a light emitting part 47 and a light receiving part 48 described later of the detection part 42 at a position spaced apart from the conveying member 40 in the radial direction. It is formed in a cylindrical shape having a larger diameter than the conveyance shaft 43 (see FIG. 5). A rear end portion of the urging member 41 is attached to the front end portion of the detected portion 45.

  The shaft gear 46 has a shape longer than a drive gear 49 described later in the axial direction, is formed by providing a plurality of teeth in the circumferential direction of the conveying member 40, and is slidable in the axial direction with respect to the drive gear 49. Meshed.

  The urging member 41 is configured by a winding spring or the like having an urging force smaller than the minimum value of the breaking torque of the conveying member 40. The urging member 41 has a front end portion attached to the inner wall surface on the front side of the housing 35 and a rear end portion attached to the front end portion of the conveying member 40, so that the conveying member 40 is moved backward (in the conveying direction, FIG. 4). (See arrow Z).

  The detection unit 42 detects the movement of the transport member 40 forward (in the direction opposite to the transport direction). For example, the detection unit 42 includes an optical unit including a light emitting unit 47 that emits detection light and a light receiving unit 48 that receives the detection light. The light emitting unit 47 and the light receiving unit 8 are configured to be opposed to each other around the front of the conveying member 40.

  In addition, the drive unit 36 of the toner transport unit 10 is configured by a motor or the like that supplies a predetermined drive force to the transport member 40, and includes a drive gear 49 that transmits the drive force to the transport member 40. The drive gear 49 is formed in a shape shorter than the shaft gear 46 of the conveying member 40 in the axial direction, for example.

  Next, the operation of the toner transport unit 10 of the printer 1 having such a configuration will be described with reference to the flowchart of FIG.

  In the printer 1, during the image forming process or the preparation process, the toner sensor 34 of the developing unit 11 determines whether or not the toner amount in the developing unit main body 27 is sufficient (step S1).

  If the toner amount in the developing device main body 27 is sufficient (step S1: YES), the image forming process or its preparation processing is continued as it is, and the developing device 11 repeatedly detects the toner amount by the toner sensor 34 ( Step S1).

  On the other hand, when the amount of toner in the developing device main body 27 is insufficient (step S1: NO), for example, the toner conveyance unit 10 is driven by a control unit (not shown) such as a CPU that controls the printer 1. The part 36 is actuated (step S2). Then, the driving force of the drive unit 36 is transmitted to the shaft gear 46 of the conveying member 40 via the driving gear 49 to rotate the shaft gear 46 and the conveying shaft 43 connected thereto, that is, the conveying member 40 is rotated. Let

  When the transport member 40 rotates, the toner introduced from the toner container 9 into the housing 35 of the toner transport unit 10 is transported backward by the transport fins 44 provided around the transport shaft 43.

  At this time, in the toner transport unit 10, the detection unit 42 detects whether or not the transport member 40 has moved forward (step S3). If no abnormality such as toner clogging has occurred in the housing 35, the conveying member 40 does not move forward as shown in FIG. 4, and the detecting unit 42 detects the detected unit 45. No (step S3: NO). Therefore, since the detection unit 42 detects that there is no abnormality in the developer conveyance in the toner conveyance unit 10, the toner conveyance unit 10 can supply a sufficient amount of toner to the developing device 11, and then the printer 1 Continues the image forming process or the like (step S4).

  On the other hand, when an abnormality such as toner clogging occurs in the housing 35 of the toner conveying unit 10, the rear surface of the conveying fin 44 of the conveying member 40 receives a load from the clogged toner, and thus the conveying shaft 43 moves forward. The driving force is generated. Therefore, the conveyance member 40 moves forward against the urging force of the urging member 41. Since the shaft gear 46 of the conveying member 40 has a sufficient length in the axial direction than the drive gear 49 of the drive unit 36, the shaft gear 46 slides forward on the drive gear 49 without being disengaged from each other. Move.

  As described above, when the conveying member 40 moves forward, the detected portion 45 enters between the light emitting portion 47 and the light receiving portion 48 of the detecting portion 42 and emits the detection light emitted from the light emitting portion 47 to the light receiving portion 48. Cut off. Thereby, the detection part 42 detects the to-be-detected part 45, and detects the movement to the front of the conveyance member 40 (step S3: YES). Accordingly, the detection unit 42 detects that there is an abnormality in the developer conveyance in the toner conveyance unit 10.

  When the detection unit 42 detects the forward movement of the conveying member 40, for example, the control unit (not shown) stops the driving unit 36 of the toner conveying unit 10 (step S5) and displays the printer 1 (see FIG. An error such as toner clogging is displayed (not shown) (step S6).

  According to the present embodiment, as described above, the developer transport mechanism of the toner transport unit 10 includes the rotatable transport member 40 that transports toner in the transport direction along the axial direction and the rotation of the transport member 40. And a drive unit 36 for driving the motor. Further, the developer transport mechanism has a biasing force that is smaller than the minimum value of the breaking torque of the transport member 40, and a biasing member 41 that biases the transport member 40 rearward, and a direction opposite to the transport direction. And a detection unit 42 that detects the movement of the conveyance member 40 forward. When the detection unit 42 detects the forward movement of the conveying member 40 against the urging force of the urging member 41, the driving unit 36 is stopped.

  As a result, even when an abnormality such as toner clogging occurs in the housing 35 of the toner transport unit 10, the transport member 40 is moved forward before the load applied to the transport member 40 by the driving force of the drive unit 36 reaches the breaking torque. Is detected by the detection unit 42, and the drive unit 36 stops. Therefore, when there is an abnormality in the developer conveyance, the developer conveyance can be stopped without destroying the conveyance member 40, that is, without destroying the developer conveyance mechanism. In addition, the developer transport mechanism described above can realize abnormality detection of developer transport using low-cost components such as the biasing member 41 and the detection unit 42. That is, the developer conveyance mechanism of the present invention can prevent the conveyance member 40 from being broken by detecting an abnormality such as toner clogging without increasing the cost in the developer conveyance.

  In addition, as described above, even if an abnormality such as toner clogging occurs, the toner transport unit 10 does not destroy the parts of the developer transport mechanism such as the transport member 40 and its supporting parts. The toner does not scatter in the printer 1, and the toner transport unit 10 can be reused by cleaning the inside of the housing 35, that is, the developer transport path.

  Further, the toner transport unit 10 is prevented from malfunctioning due to overcurrent flowing through the drive unit 36 and its control circuit (not shown) because the drive unit 36 is stopped when an abnormality such as toner clogging occurs. can do.

  Further, according to the present embodiment, in the developer transport mechanism of the toner transport unit 10, the drive unit 36 includes the drive gear 49 that transmits the driving force to the transport member 40, and the transport member 40 has a shaft at the rear end. A gear 46 is provided. The shaft gear 46 has a shape longer than the drive gear 49 in the axial direction, is formed by providing a plurality of teeth in the circumferential direction of the conveying member 40, and is slidable in the axial direction with respect to the drive gear 49. Meshed. Thereby, the conveyance member 40 can be slid forward without the shaft gear 46 being detached from the drive gear 49.

  Further, according to the present embodiment, in the developer transport mechanism of the toner transport unit 10, the detection unit 42 includes the light emitting unit 47 and the light receiving unit 48 that are opposed to each other around the front of the transport member 40. 40 is provided with a detected portion 45 at the front end having a larger area than the cross-sectional area of the optical path between the light emitting portion 47 and the light receiving portion 8 at a position spaced apart from the conveying member 40 in the radial direction. The detected portion 45 moves forward according to the conveying member 40 and enters between the light emitting portion 47 and the light receiving portion 8 when the conveying member 40 moves forward against the urging force of the urging member 41. To do. As a result, the detection unit 42 of the developer transport mechanism can be configured using an optical sensor configured by the light emitting unit 47 and the light receiving unit 48, so that the developer transport abnormality can be detected with a simple and inexpensive configuration. can do.

  In the present embodiment, the configuration of the detection unit 42 including the light emitting unit 47 and the light receiving unit 48 has been described. However, the detection unit 42 indicates that the transport member 40 has moved forward against the biasing force of the biasing member 41. The configuration is not limited to this as long as it can be detected. For example, in another embodiment, the detection unit may include a contact type detection unit 50 such as a push switch or a contact type sensor that detects contact from the rear. As shown in FIG. 8, the contact-type detection unit 50 is disposed at a position separated from the conveyance member 40 in the radial direction and in front of the conveyance member 40, for example, of the housing 35 of the toner conveyance unit 10. It is attached to the front inner wall surface.

  When this contact type detection unit 50 is applied, the detected portion 45 on the conveyance member 40 side is attached to the front end of the conveyance member 40 and faces the contact type detection unit 50 at a position spaced from the conveyance member 40 in the radial direction. Configured as follows. When the transport member 40 moves forward against the biasing force of the biasing member 41, the detected unit 45 moves forward according to the transport member 40 and contacts the contact-type detection unit 50.

  As a result, since the developer transport mechanism can be configured using various contact-type detection units 50, the developer transport abnormality can be detected with an appropriate configuration for each device to which the developer transport mechanism is applied. Can be realized.

  In this embodiment, although the structure which stops the drive part 36 when the detection part 42 detected the movement to the front of the conveyance member 40 was demonstrated, it is not limited to this. For example, in another embodiment, when the detection unit 42 detects the forward movement of the conveying member 40, the driving force of the driving unit 36 is decreased, for example, gradually decreased, and then after a predetermined time has elapsed. If the detection unit 42 detects the forward movement of the conveying member 40, the drive unit 36 may be stopped. Further, after the drive force of the drive unit 36 is reduced, the drive unit 36 is configured to return the drive force if the detection unit 42 does not detect the forward movement of the conveying member 40 after a predetermined time has elapsed. Also good. Accordingly, if the conveying member 40 rotates again by reducing the driving force of the driving unit 36, the conveying member 40 moves rearward by the urging force of the urging member 41 and shifts to a normal operation. It is possible to avoid unnecessary stopping of the driving unit 36 due to toner clogging or the like.

  In the present embodiment, the configuration in which the developer transport mechanism is provided in the toner transport unit 10 that transports the toner from the toner container 9 to the developing device 11 has been described. However, the present invention is not limited to this. For example, in another embodiment, the developer transport mechanism of the present invention is used to detect abnormality in developer transport by the transport member 26 provided in the toner container 9 or the transport member (not shown) provided in the developing device 11. It is possible to apply. In another embodiment, the developer transport mechanism of the present invention is applied in order to realize abnormality detection of developer transport in a toner recovery device (not shown) provided in the printer 1 or other developer transport device. Is possible.

  In the present embodiment, the case where the configuration of the present invention is applied to the printer 1 has been described. However, in another different embodiment, the configuration of the present invention may be applied to an image forming apparatus such as a copying machine, a facsimile, or a multifunction peripheral. Good.

1 Printer (image forming device)
9 Toner container 10 Toner transport section (Developer transport mechanism)
DESCRIPTION OF SYMBOLS 11 Developing device 36 Drive part 40 Conveyance member 41 Energizing member 42 Detection part 43 Conveyance shaft 44 Conveyance fin 45 Detected part 46 Shaft gear 47 Light emission part 48 Light reception part 49 Drive gear

Claims (12)

A rotatable transport member that transports the developer in the transport direction along the axial direction;
A drive unit for driving rotation of the conveying member;
An urging member having an urging force smaller than a minimum value of the breaking torque of the conveying member, and urging the conveying member in the conveying direction;
A developer transport mechanism, comprising: a detection unit that detects movement of the transport member in a direction opposite to the transport direction.   2. The developer conveyance according to claim 1, wherein the driving unit is stopped when the detection unit detects the movement of the conveyance member in the reverse direction against the urging force of the urging member. mechanism.   When the detection unit detects the movement of the conveying member in the opposite direction against the urging force of the urging member, the driving force of the driving unit is reduced, and then the detection unit The developer transport mechanism according to claim 1, wherein the driving unit is stopped if the movement in the reverse direction is detected. The driving unit includes a driving gear that transmits a driving force to the conveying member,
The conveying member includes a shaft gear having a shape longer than the driving gear in the axial direction at an end portion on the conveying direction side, and the shaft gear is formed by providing a plurality of teeth in the circumferential direction of the conveying member. 4. The developer transport mechanism according to claim 1, wherein the developer transport mechanism is slidably engaged with the drive gear in the axial direction. The detection unit includes a light-emitting unit and a light-receiving unit that are opposed to each other around the opposite side of the transport member,
The conveying member includes a detected portion having an area larger than an optical path cross-sectional area between the light emitting portion and the light receiving portion at a position spaced apart from the conveying member in the radial direction at an end on the reverse direction side. When the transport member moves in the reverse direction against the biasing force of the biasing member, the detected portion moves in the reverse direction according to the transport member and moves between the light emitting unit and the light receiving unit. The developer transport mechanism according to claim 1, wherein the developer transport mechanism enters between them. The detection unit is arranged at a position spaced apart from the transport member in the radial direction and on the reverse direction side of the transport member, and configured to detect contact from the transport direction side,
The conveying member includes a detected portion facing the detecting portion at a position spaced apart from the conveying member in the radial direction at an end portion on the opposite direction side, and the detected member is biased by the conveying member. 5. The development according to claim 1, wherein when the member moves in the reverse direction against a biasing force of the member, the developer moves in the reverse direction according to the conveying member and contacts the detection unit. 6. Agent transport mechanism.   An image forming apparatus comprising the developer container according to any one of claims 1 to 6 in a developer container.   An image forming apparatus comprising the developer conveying mechanism according to claim 1 in a developing device.   An image forming apparatus comprising the developer transport mechanism according to claim 1 in a developer transport unit that transports the developer from a developer container to a developing device. In a state where the conveying member is urged in the conveying direction along the axial direction by the urging member having an urging force smaller than the minimum value of the breaking torque of the conveying member, the conveying member is rotated by the driving force of the driving unit. Transporting the developer in the transport direction,
When the movement of the conveying member in the opposite direction against the urging force of the urging member is detected by the detection unit that detects the movement of the conveying member in the direction opposite to the conveying direction, the developer And a step of detecting that there has been an abnormality in the conveyance of the developer.   11. The developer conveyance abnormality detection method according to claim 10, wherein when the abnormality in the developer conveyance is detected, the driving unit is stopped.   When it is detected that there is an abnormality in the transport of the developer, the driving force of the drive unit is reduced, and then the detection unit detects the movement of the transport member in the reverse direction. The method according to claim 10, wherein the driving unit is stopped.

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