JP2019082595A - Image forming apparatus - Google Patents

Abstract

To provide an image forming apparatus that can simultaneously execute determination as to whether a drum unit is attached to an image forming apparatus body and determination as to whether the amount of toner recovered into a recovery container provided in a cleaning device is less than a predetermined amount, on the basis of output from a single sensor.SOLUTION: A state determination unit 100 comprises: a unit conjunction member 43b that is displaced in conjunction with an attachment operation of a drum unit to an image forming apparatus body; a recovery container part conjunction member 42b that is pressed by a recovery toner retained in a recovery container part and displaced; a single displacement detection sensor 50 that can detect the unit conjunction member 43b and recovery container part conjunction member 42b; and a determination processing unit 60 that determines which of a regular state and an irregular state the drum unit 30 is in on the basis of a signal from the displacement detection sensor 50.SELECTED DRAWING: Figure 3

Description

  The present invention relates to an image forming apparatus.

  Generally, in an electrophotographic image forming apparatus, an electrostatic latent image formed on an image carrier such as a photosensitive drum is visualized using a developing device, and the visible image (toner image) is formed on a recording medium. After transfer, fixing is performed. The toner remaining on the surface of the image carrier is removed by the cleaning device.

  In the image forming apparatus shown in Patent Document 1, the cleaning device and the photosensitive drum are integrated as a drum unit. The cleaning device is provided with a recovery container for storing waste toner (recovered toner) removed from the surface of the image carrier. This type of image forming apparatus usually includes a drum detection sensor and a full detection sensor. The drum detection sensor detects whether or not the drum unit is attached to the image forming apparatus main body. The fullness detection sensor detects whether the toner in the collection container is full (more than a predetermined amount).

JP, 2012-141521, A

  The above-described conventional image forming apparatus requires two sensors, a drum detection sensor and a full detection sensor, which increases the cost.

  The present invention has been made in view of such a point, and the purpose of the present invention is to determine whether or not a drum unit is attached to an image forming apparatus main body, and to a collection container provided in a cleaning device. It is an object of the present invention to provide an image forming apparatus capable of performing together with the determination of whether the amount of collected toner is less than a predetermined amount based on the output of one sensor.

  The image forming apparatus according to the present invention is mounted with a drum unit having a photosensitive drum, a cleaning device for collecting residual toner on the surface of the photosensitive drum, and a collection container portion for storing the toner collected by the cleaning device. Image forming apparatus main body.

  The normal state in which the drum unit is attached to the image forming apparatus main body and the recovered toner in the recovery container portion is less than the predetermined amount, and the drum unit is not attached to the image forming apparatus main body or the drum unit is attached The image forming apparatus further includes a state determination unit that determines that the collected toner in the collection container unit is in the non-normal state where the collected toner amount exceeds the predetermined amount, and the state determination unit interlocks with the mounting operation of the drum unit to the image forming apparatus main body. A unit interlocking member which is displaced, a recovery container interlocking member which is pressed and displaced by the recovery toner stored in the recovery container, and a displacement which can detect the unit interlocking member and the recovery container interlocking member The drum unit is in the normal state and the non-normal state on the basis of the detection sensor and the signal from the displacement detection sensor. And a determination processing unit that determines which state is the state, and the recovery container unit interlocking member and the unit interlocking member are output from the displacement detection sensor in the normal state and the non-normal state. The output signals are arranged to be different.

  According to the present invention, it is determined whether the drum unit is attached to the image forming apparatus main body, and whether the amount of recovered toner in the recovery container provided in the cleaning device is less than the predetermined amount. According to the output of one sensor, an executable image forming apparatus is provided.

FIG. 1 is a schematic view showing an internal structure of the image forming apparatus in the embodiment. FIG. 2 is an enlarged view showing the drum unit in FIG. 1 and the periphery thereof. FIG. 3 is a perspective view showing a drum unit mounted on the image forming apparatus main body and a displacement mechanism (a part of a state determination unit) provided on the image forming apparatus main body. FIG. 4 is an external perspective view showing only the displacement mechanism when the drum unit is not attached. FIG. 5 is a schematic view showing an assembly structure of the second shaft with respect to the first shaft. FIG. 6 is an explanatory view for explaining the movement of the flexible wall contact member when the amount of collected toner exceeds a predetermined amount in a state where the drum unit is mounted on the image forming apparatus main body. FIG. 7 is an explanatory view for explaining the movement of the drum contact member when the drum unit is mounted on the image forming apparatus main body. FIG. 8 is a block diagram showing a part of a control system of the image forming apparatus. FIG. 9 is a table in which the state of the drum unit is classified into three and output signals of the displacement detection sensor in each state are summarized. FIG. 10 is a view corresponding to FIG. 3 showing a state (normal state) in which the drum unit is mounted on the image forming apparatus main body and the toner in the collection container is less than a predetermined amount. FIG. 11 is a schematic view of the collection container interlocking member and the unit interlocking member as viewed in the shaft axial direction in the state of FIG. FIG. 12 is a schematic view of the collection container unit interlocking member and the unit interlocking member as viewed in the shaft axial direction in the state of FIG. 4. FIG. 13 is a view corresponding to FIG. 3 showing a state in which the drum unit is attached to the main body of the image forming apparatus and the toner in the recovery container portion becomes a predetermined amount or more. FIG. 14 is a schematic view of the collection container interlocking member and the unit interlocking member as viewed in the shaft axial direction in the state of FIG. 13. It is a flowchart which shows the content of the state determination control performed by the control part.

  Hereinafter, embodiments of the present invention will be described in detail based on the drawings. The present invention is not limited to the following embodiments.

<< Embodiment >>
FIG. 1 is a cross-sectional view showing a schematic configuration of an image forming apparatus 1 in the present embodiment.

  As shown in FIG. 1, the image forming apparatus 1 includes a box-like image forming apparatus main body 2, a manual sheet feeding unit 6, a cassette sheet feeding unit 7, an image forming unit 8, a fixing unit 9, and a discharge unit. And a unit 10. Then, the image forming apparatus 1 forms an image on a sheet based on image data transmitted from a terminal (not shown) or the like while conveying the sheet along the conveyance path L in the image forming apparatus main body 2. Is configured. In the following description, the front side and the rear side mean the front side and the rear side in the paper surface vertical direction of FIG. 1, and the left side and the right side mean the left side and the right side when the image forming apparatus 1 is viewed from the front side. Do.

  The manual feed unit 6 includes a manual feed tray 4 provided on one side of the image forming apparatus main body 2 so as to be openable and closable, and a manual feed paper feed roller 5 rotatably provided inside the image forming apparatus main body 2. And.

  The cassette feeding unit 7 is provided at the bottom of the image forming apparatus main body 2. The cassette sheet feeding unit 7 separates the sheet taken out one by one from the sheet feeding cassette 11 for storing a plurality of sheets overlapped with one another, the pickup roller 12 for taking out the sheets in the sheet feeding cassette 11 one by one, and A feed roller 13 and a retard roller 14 are provided to feed the sheet to the conveyance path L.

  The image forming unit 8 is provided above the cassette feeding unit 7 in the image forming apparatus main body 2. The image forming unit 8 includes a photosensitive drum 16 as an image carrier rotatably provided in the image forming apparatus main body 2, a charger 17 disposed around the photosensitive drum 16, and a developing unit 18. A transfer roller 19, a cleaning device 20, a laser scanning unit (LSU) 26 which is an optical scanning device disposed above the photosensitive drum 16, and a toner container 21 for supplying toner to the developing unit 18 are provided. Then, the image forming unit 8 forms an image on the sheet supplied from the manual sheet feeding unit 6 or the cassette sheet feeding unit 7.

  The conveyance path L is provided with a pair of registration rollers 15 which supply the sheet having been fed out to the image forming section 8 at a predetermined timing after temporarily making the sheet stand by.

  The fixing unit 9 is disposed to the side of the image forming unit 8. The fixing unit 9 includes a fixing roller 22 and a pressure roller 23 which are pressed against each other to rotate. Then, the fixing unit 9 is configured to fix the toner image transferred onto the sheet by the image forming unit 8 to the sheet.

  The paper discharge unit 10 is provided above the fixing unit 9. The paper discharge unit 10 includes a paper discharge tray 3, a paper discharge roller pair 24 for conveying the paper to the paper discharge tray 3, and a plurality of conveyance guide ribs 25 for guiding the paper to the paper discharge roller pair 24. . The sheet discharge tray 3 is formed in a concave shape in the upper portion of the image forming apparatus main body 2.

  When the image forming apparatus 1 receives image data, the photosensitive drum 16 is rotationally driven in the image forming unit 8, and the charger 17 charges the surface of the photosensitive drum 16.

  Then, based on the image data, laser light is emitted from the laser scanning unit 26 to the photosensitive drum 16. An electrostatic latent image is formed on the surface of the photosensitive drum 16 by being irradiated with a laser beam. The electrostatic latent image formed on the photosensitive drum 16 is developed with the toner charged in the developing unit 18 to be visualized as a toner image.

  Thereafter, the sheet passes between the transfer roller 19 and the photosensitive drum 16. During this passage, a transfer bias of the reverse polarity to the toner is applied to the transfer roller. Thereby, the toner image on the photosensitive drum 16 is transferred to the sheet. The sheet on which the toner image has been transferred is heated and pressed by the fixing roller 22 and the pressure roller 23 in the fixing unit 9. As a result, the toner image is fixed to the sheet. After transferring the toner image from the photosensitive drum 16 to the sheet, the residual toner adhering to the surface of the photosensitive drum 16 is removed by the cleaning device 20.

  The photosensitive drum 16, the cleaning device 20 and the charger 17 are integrated to constitute a drum unit 30.

   FIG. 2 is an enlarged view of the drum unit 30 in FIG. The cleaning device 20 constituting the drum unit 30 together with the photosensitive drum 16 and the charger 17 has a housing 31 having an opening on the side of the photosensitive drum 16. The inside of the housing 31 is divided into two by a partition wall 32, and a cleaning blade 33 is disposed on the photosensitive drum 16 side of the partition wall 32. The cleaning blade 33 is disposed such that its tip end abuts on the circumferential surface of the photosensitive drum 16. Further, a recovery container portion 34 is provided on the opposite side to the cleaning blade 33 side with the partition wall 32 interposed therebetween. The recovery container unit 34 stores the toner scraped off the photosensitive drum 16 by the cleaning blade 33. Between the lower end portion of the partition wall 32 and the bottom wall of the housing 31, a communication portion 35 communicating both sides of the partition wall 32 is provided. The communicating portion 35 is provided with an elliptic cylindrical sweep roller 36 for guiding the toner scraped off by the cleaning blade 33 to the recovery container portion 34.

  A rectangular opening 37 (see FIGS. 2 and 3) is formed at the center of the right side wall (outer wall) of the recovery container portion 34 in the front-rear direction. The opening 37 is closed by a flexible wall 38. The flexible wall 38 is made of, for example, a PET film. The flexible wall 38 is not limited to the PET film, and may be any member having flexibility. When the amount of recovered toner in the recovery container portion 34 becomes equal to or more than a predetermined amount (for example, 90% or more of full), the flexible wall 38 is pressed outward by the recovered toner toward the drum and bulges (see FIG. 6).

  FIG. 3 shows a drum unit 30 mounted on the image forming apparatus main body 2 and a state determination unit 100 provided on the image forming apparatus main body 2.

  The state determination unit 100 determines whether the drum unit 30 is in the normal state or the non-normal state with respect to the image forming apparatus 1. Here, the normal state means that the drum unit 30 is attached to the image forming apparatus main body 2 and the collected toner in the collection container portion 34 is less than a predetermined amount. The non-normal state means a state in which the toner in the collection container portion 34 is not less than a predetermined amount although the drum unit 30 is not attached or the drum unit 30 is attached.

  Specifically, the state determination unit 100 includes a displacement mechanism 40, a displacement detection sensor 50, and a controller (determination processing unit) 60.

  As shown in FIG. 4, the displacement mechanism 40 has a bracket 41, a first shaft portion 42 and a second shaft portion 43. The bracket 41 has a rectangular horizontal plate 41a extending in the front-rear direction, and a pair of support plates 41b hanging from both ends in the front-rear direction of the horizontal plate 41a.

  The first shaft portion 42 is a cylindrical member extending in the front-rear direction, and both ends thereof are rotatably supported by the pair of support plates 41 b. A flexible wall contact member 42 a is connected to a portion near the rear end of the middle portion of the first shaft portion 42. The flexible wall contact member 42 a extends radially outward from the circumferential surface of the first shaft portion 42. The distal end portion of the flexible wall contact member 42 a contacts the flexible wall 38 provided on the right side wall of the housing 31 when the drum unit 30 is mounted on the image forming apparatus main body 2. Further, a long plate-like recovery container portion interlocking member 42 b is connected to the front end portion of the first shaft portion 42. The recovery container portion interlocking member 42 b extends radially outward from the circumferential surface of the first shaft portion 42.

  As shown in FIG. 6, when the flexible wall 38 bulges outward with the increase of the collected toner in the collection container portion 34, the flexible wall contact member 42 a is moved outward by the flexible wall 38. It is pushed to the side. As a result, the flexible wall contact member 42a is pivoted together with the first shaft portion 42 in the counterclockwise direction of the drawing (the direction of the dashed double-dotted arrow in the drawing). As a result, the recovery container portion interlocking member 42b (see FIGS. 4 and 5) pivots with the first shaft portion 42 in the counterclockwise direction in the drawing.

  As shown in FIG. 5, the second shaft portion 43 is a cylindrical member extending in the front-rear direction, and is rotatably supported by being inserted into the cylindrical first shaft portion 42. A unit contact plate 43 a is connected to the rear end surface of the second shaft portion 43. The unit contact plate 43 a extends radially outward from the axial center side of the second shaft portion 43. The lower end portion of the unit contact plate 43a contacts the bottom wall surface 31b (see FIG. 7) of the groove 31a formed in the housing 31 when the drum unit 30 is mounted on the image forming apparatus main body 2. A long plate-like unit interlocking member 43 b is connected to the front end of the second shaft portion 43. The unit interlocking member 43 b extends radially outward from the axial center side of the second shaft portion 43.

  As shown in FIG. 7, when the drum unit 30 is attached to the image forming apparatus main body 2, the unit contact plate 43 a is pressed by the bottom wall surface 31 b of the groove 31 a of the housing 31, and the counterclockwise as shown in FIG. It turns in the turning direction (the direction of the two-dot chained arrow in the figure). As a result, the unit interlocking member 43 b (see FIGS. 4 and 5) pivots with the second shaft portion 43 in the counterclockwise direction in the drawing.

  The displacement detection sensor 50 is provided near the lower end portions of the recovery container portion interlocking member 42b and the unit interlocking member 43b. The displacement detection sensor 50 includes a light emitting unit 50a and a light receiving unit 50b which are disposed to face each other in the front-rear direction. The light emitting unit 50 a emits light, and the light receiving unit 50 b receives the light emitted from the light emitting unit 50 a. The displacement detection sensor 50 outputs a light blocking signal when the light emitting portion 50a and the light receiving portion 50b are in a light blocking state, and outputs a light transmitting signal when the light blocking state is released. The collection container portion interlocking member 42b and the unit interlocking member 43b are movable between a light shielding position for shielding light between the light emitting portion 50a and the light receiving portion 50b and a light transmitting position for releasing the light shielding.

  The controller 60 is a microcomputer comprising a CPU, a ROM, a RAM and the like. As shown in FIG. 8, the controller 60 is connected to the displacement detection sensor 50 and the open / close detection sensor 51 via signal lines. The open / close detection sensor 51 detects an open / close operation of a front cover (not shown). The front cover is a cover that is opened and closed when the drum unit 30 is attached to the image forming apparatus main body 2, and constitutes a part of the exterior cover of the image forming apparatus 1.

  The controller 60 determines the state of the drum unit 30 based on the signals received from the displacement detection sensor 50 and the open / close detection sensor 51.

  FIG. 9 is a table summarizing the relationship between the state of the drum unit 30 that can be determined by the controller 60 and the output signal of the displacement detection sensor 50 in each state. As shown in this table, the controller 60 is capable of determining the three states of state I to state III.

  In state I, the drum unit 30 is mounted on the image forming apparatus main body 2 and the amount of recovered toner in the recovery container portion 34 is less than a predetermined amount (that is, the normal state). In the above state I, as shown in FIGS. 10 and 11, the recovery container portion interlocking member 42b and the unit interlocking member 43b both move at the light transmitting position (outside of the light emitting portion 50a and the light receiving portion 50b of the displacement detection sensor 50). Therefore, a light transmission signal is output from the displacement detection sensor 50.

  In state II, the drum unit 30 is not attached to the image forming apparatus main body 2. In this state, as shown in FIG. 4 and FIG. The member 43 b moves to the light blocking position (between the light emitting unit 50 a and the light receiving unit 50 b of the displacement detection sensor 50). Therefore, the light shielding signal is output from the displacement detection sensor 50.

  State III is a state (full or nearly full) in which the amount of toner in the recovery container portion 34 of the drum unit 30 attached to the image forming apparatus main body 2 is equal to or more than a predetermined amount. In this state, as shown in FIGS. 13 and 14, the unit interlocking member 43b moves to the light transmitting position, and the collection container interlocking member 42b moves to the light shielding position. Therefore, the light shielding signal is output from the displacement detection sensor 50.

  As described above, the controller 60 executes the state determination process by noting that the signals output from the displacement detection sensor 50 are different between the state I (that is, normal state) and the states II and III (non-normal state). . Here, the state I (normal state) and the states II and III (non-normal state) can be determined only by the output signal of the displacement detection sensor 50, but the states II and III are output signals of the displacement detection sensor 50 It can not be determined by itself. Therefore, the controller 60 determines the state II and the state III in consideration of the detection signal from the open / close detection sensor 51 as well.

  FIG. 15 is a flowchart showing details of the state determination process executed by the controller 60.

  In step S1, it is determined whether a light shielding signal has been received from the displacement detection sensor 50. If the determination is NO, the process proceeds to step S5, and if YES, the process proceeds to step S2.

  In step S2, based on the output signal from the open / close detection sensor 51 and the operation signal from the image forming unit 8, the open / close operation (open and close operation) of the front cover is executed and the printing operation is executed after the execution. Determine if When this determination is NO, while progressing to step S6, when it is YES, it progresses to step S3.

  In step S3, it is determined that the drum unit 30 is mounted and the collected toner in the collection container unit 34 is a predetermined amount or more (state III in FIG. 9).

  In step S4, a message prompting replacement of the drum unit 30 is displayed on the display unit 61 of the image forming apparatus 1.

  In step S5, which proceeds when the determination in step S1 is NO, the drum unit 30 is mounted and the collected toner in the collection container portion 34 is in a state of less than a predetermined amount (state I of FIG. 9; normal state). Judge, then return.

  In step S6, the process proceeds when the determination in step S2 is NO, the state in which the drum unit 30 is not attached (state II in FIG. 9) and the state in which the collected toner in the recovery container portion 34 is attached although the drum unit 30 is attached. It is determined that there is any state with the state (state III in FIG. 9) that is above the fixed amount.

  In step S7, a message prompting the user to confirm the drum unit 30 is displayed on the display unit 61 of the image forming apparatus 1, and the process returns.

  As described above, in the present embodiment, the state determination unit 100 stores the unit interlocking member 43 b displaced in conjunction with the mounting operation of the drum unit 30 to the image forming apparatus main body 2 and the collection container unit 34. It is possible to detect the recovery container portion interlocking member 42b, the unit interlocking member 43b and the recovery container portion interlocking member 42b, which are indirectly pressed and displaced by the recovery toner via the flexible wall 38 (and the flexible wall contact member 42a). And a controller (determination processing unit) 60 which determines whether the drum unit 30 is in the normal state or the non-normal state based on a single displacement detection sensor 50 and a signal from the displacement detection sensor 50. Is equipped.

  The recovery container unit interlocking member 42b and the unit interlocking member 43b are arranged so that the output signals output from the displacement detection sensor 50 differ between the normal state and the non-normal state.

  According to this configuration, the determination of whether or not the drum unit 30 is attached to the image forming apparatus main body 2 and the determination of whether or not the amount of recovered toner in the recovery container portion 34 is less than a predetermined amount Based on the output of the two sensors 50, it can carry out together.

  When the controller 60 determines that the drum unit 30 is in the non-normal state based on the signal from the displacement detection sensor 50, the open / close operation of the open / close cover is detected by the open / close detection sensor 51 and after the detection It is determined whether the printing operation has been performed (the determination process of step S2 is performed), and when it is determined that the printing operation has been performed (YES in step S2), the drum unit 30 is mounted on the image forming apparatus main body 2 However, it is configured to determine that the toner amount of the recovery container unit 34 is equal to or more than the predetermined amount (step S3).

According to this configuration, it is possible to accurately determine the state in which the amount of recovered toner in the recovery container portion 34 is equal to or more than the predetermined amount and to prompt the user to replace the drum unit 30 (step S4).
Other Embodiments
In the above embodiment, an example in which the recovery container interlocking member 42b is indirectly pressed by the recovery toner through the flexible wall 38 has been described, but the present invention is not limited to this. It may be pressed directly by the toner. In this case, for example, the recovery container interlocking member 42b is rotatably supported by the shaft, the base end of the recovery container interlocking member 42b is positioned in the recovery container 34, and the tip end is detected by the displacement detection sensor 50 You should do it.

  As described above, the present invention is useful for an image forming apparatus.

1: Image forming apparatus 2: Image forming apparatus main body 16: Photosensitive drum 20: Cleaning device 30: Drum unit 33: Cleaning blade 34: Recovery container portion 38: Flexible wall 42b: Recovery container portion interlocking member 43b: Unit interlocking member 50 : Displacement detection sensor 51: Open / close detection sensor 60: Controller (judgment processing unit)
100: State determination unit

Claims (3)

Image forming apparatus provided with a drum unit having a photosensitive drum, a cleaning device for collecting residual toner on the surface of the photosensitive drum, and a collection container portion for storing the toner collected by the cleaning device In the forming device
The normal state in which the drum unit is attached to the image forming apparatus main body and the recovered toner in the recovery container portion is less than the predetermined amount, and the drum unit is not attached to the image forming apparatus main body or the drum unit is attached A state determination unit for determining the non-normal state in which the collected toner in the collection container unit is equal to or more than the predetermined amount,
The state determination unit is a unit interlocking member which is displaced in conjunction with the mounting operation of the drum unit to the image forming apparatus main body, and a recovery container portion interlocking member which is pressed and displaced by the recovery toner stored in the recovery container portion. And one displacement detection sensor capable of detecting the unit interlocking member and the collection container interlocking member, and a signal from the displacement detection sensor, the drum unit is in any of the normal state and the non-normal state. A determination processing unit that determines whether or not there is a state;
The image forming apparatus, wherein the collection container interlocking member and the unit interlocking member are arranged to make output signals output from the displacement detection sensor different between the normal state and the non-normal state. In the image forming apparatus according to claim 1,
The outer wall of the collection container portion is provided with a flexible wall which is pressed and expanded by the collected toner stored in the collection container portion,
The image forming apparatus, wherein the recovery container portion interlocking member is indirectly pressed by the recovery toner via the flexible wall and interlocked with deformation of the flexible wall. In the image forming apparatus according to claim 1 or 2,
An opening / closing cover provided in the image forming apparatus main body and opened / closed when the drum unit is attached to the image forming apparatus main body;
And an open / close detection sensor for detecting the open / close operation of the open / close cover,
When the determination processing unit determines that the drum unit is in the non-normal state based on the signal from the displacement detection sensor, the open / close operation of the open / close cover is detected by the open / close detection sensor After the detection, it is determined whether or not the printing operation has been executed. If it is determined that the printing operation has been executed, although the drum unit is mounted on the image forming apparatus main body, the recovered toner in the recovery container portion is the predetermined amount or more An image forming apparatus configured to determine that the

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