JP2017097232A - Image forming unit and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming unit that is excellent in handleability.SOLUTION: The image forming unit comprises: a developer supply part that supplies a developer; a developer storage chamber that stores the developer supplied from the developer supply part; and a developer discharge part that discharges a developer remaining in the developer storage chamber, and includes: a developing part that forms a developer image with a developer; a first detection part that detects an accumulated operation amount of the developing part; and a control part that, when the accumulated operation amount of the developing part detected by the first detection part reaches a reference value, controls the developer discharge part to discharge the developer from the developer storage chamber.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an image forming unit that forms an image using an electrophotographic system and an image forming apparatus including the image forming unit.

  2. Description of the Related Art An image forming apparatus including an image forming unit having a developing device that forms a developer image and a developer container (toner cartridge) configured to be detachable from the developing device is known (for example, Patent Document 1). reference).

JP 2008-83441 A

  In such an image forming apparatus, when the developing device is replaced due to product life or the like, the developer remaining in the developing device removed from the image forming device may be ejected to the outside.

  The present invention has been made in view of such problems, and an object thereof is to provide an image forming unit excellent in handleability and an image forming apparatus including the image forming unit.

  An image forming unit according to an embodiment of the present invention includes a developer supply unit that supplies a developer, a developer storage chamber that stores the developer supplied by the developer supply unit, and a developer storage chamber. A developer discharge unit that discharges the developer to be discharged, forms a developer image by the developer, a first detection unit that detects an integrated operation amount of the development unit, and detection by the first detection unit And a control unit that controls the developer discharging unit to discharge the developer from the developer storage chamber when the integrated operation amount of the developing unit reaches a reference value.

  An image forming apparatus as one embodiment of the present invention includes the image forming unit according to one embodiment of the present invention.

  In the image forming unit and the image forming apparatus as one embodiment of the present invention, the developer is used when the integrated operation amount of the developing unit reaches the reference value (that is, when the estimated product life is reached) by the control unit. Control is performed such that the developer remaining in the discharge portion is discharged from the developer storage chamber. For this reason, at the time of work such as replacement of the developing unit, there is almost no developer in the developer accommodating chamber. Therefore, it is difficult for the developer remaining in the developer storage chamber to be ejected to the outside during work such as replacement of the development unit.

  According to the image forming unit and the image forming apparatus as one embodiment of the present invention, the discharge of the residual developer from the developer storage chamber to the outside is suppressed during work such as replacement of the developing unit, and excellent handling properties are achieved. Can be secured.

1 is a schematic diagram illustrating an example of the overall configuration of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is an enlarged cross-sectional view illustrating the image forming unit illustrated in FIG. 1. It is a perspective view showing the external appearance of the image forming unit shown in FIG. FIG. 2 is an exploded perspective view illustrating an appearance of the image forming unit illustrated in FIG. 1. It is a side view showing the external appearance of the image forming unit shown in FIG. It is a side view showing the external appearance of the image development part and side frame shown in FIG. It is a perspective view showing the internal structure of the side frame shown in FIG. 3 is a flowchart for explaining an operation of the image forming apparatus shown in FIG. 1. FIG. 2 is a cross-sectional view illustrating one state of the image forming unit during operation of the image forming apparatus illustrated in FIG. 1. 6 is another flowchart for explaining the operation of the image forming apparatus shown in FIG. 1. FIG. 10 is a cross-sectional view illustrating another state of the image forming unit during the operation of the image forming apparatus illustrated in FIG. 1.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The following description is an example of the present invention, and the present invention is not limited to the following embodiment. Further, the present invention is not limited to the arrangement, dimensions, dimensional ratios, and the like of the components shown in the drawings. The description will be made in the following order.
1. Embodiment An image forming apparatus configured to discharge a residual developer remaining in a developer storage chamber after an accumulated operation amount of a developing unit reaches a reference value.
2. Other variations

<1. Embodiment>
[Schematic configuration]
FIG. 1 is a schematic diagram illustrating an example of the overall configuration of an image forming apparatus 1 according to an embodiment of the present disclosure. FIG. 2 is a schematic diagram illustrating an enlarged main part of the image forming apparatus 1. The image forming apparatus 1 is an electrophotographic printer that forms an image (for example, a color image) on a medium (also referred to as a print medium or a transfer material) M (see FIG. 2) such as paper or film. This is a specific example corresponding to the “image forming apparatus” of the invention.

  The image forming apparatus 1 includes a medium supply unit 10, a conveyance unit 20, an image forming unit 30, a transfer unit 40, a fixing unit 50, a medium discharge unit 60, and a control unit 70 inside a housing 100. The control unit 70 controls the operations of the medium supply unit 10, the conveyance unit 20, the image forming unit 30, the transfer unit 40, the fixing unit 50, and the medium discharge unit 60, for example. In this specification, a path through which the medium M is transported is referred to as a transport path. A direction toward the medium supply unit 10 or a position closer to the medium M when viewed from an arbitrary component in the transport path is referred to as upstream. In the transport path, a direction opposite to the direction toward the medium supply unit 10 when viewed from any component, or a position further away from the medium supply unit 10 is referred to as downstream. A direction in which the medium M travels in the transport path (that is, a direction from upstream to downstream) is referred to as a transport direction F. Furthermore, a direction (for example, the Y-axis direction in FIG. 1) that is parallel to the medium M being transported on the transport path and orthogonal to the transport direction F is referred to as a width direction. The dimension in the conveyance direction F is called a length, and the dimension in the width direction is called a width. The image forming apparatus 1 may further include a display unit 80 that displays the operation state thereof (see FIG. 2). The display unit 80 may have a function as an operation unit such as a touch panel.

(Medium supply unit 10)
The medium supply unit 10 supplies the medium M to the transport unit 20 one by one. The medium supply unit 10 includes, for example, a cassette 11, a pickup roller 12, a feed roller 13, and a retard roller 14. A plurality of sheet-like media M are stacked and accommodated in the cassette 11. For example, the cassette 11 is detachably attached to the lower part of the image forming apparatus 1. The pickup roller 12, the feed roller 13, and the retard roller 14 function to sequentially feed the medium M stored in the cassette 11 to the conveyance path that reaches the conveyance unit 20. The pickup roller 12 and the feed roller 13 are controlled to rotate in the direction in which the medium is fed out toward the downstream transport unit 20 under the control of the control unit 70. The pickup roller 12 is arranged at a position where it can come into contact with the upper surface of the uppermost medium M. The feed roller 13 is disposed downstream of the pickup roller 12. The retard roller 14 prevents a plurality of media M from being fed out in an overlapping manner. The retard roller 14 is disposed at a position facing the feed roller 13 and rotates in the opposite direction to the feed roller 13.

(Conveyor 20)
The transport unit 20 transports the medium M from the medium supply unit 10 to the transfer unit 40 while regulating the skew. The transport unit 20 includes, for example, two pairs of registration rollers 21 and 22.

(Image forming unit 30)
The image forming unit 30 forms a toner image IMG on the medium M transported from the transport unit 20 (see FIG. 2). For example, as shown in FIG. 1, the image forming unit 30 includes four image forming units 30K, 30Y, 30M, and 30C. The image forming units 30K, 30Y, 30M, and 30C form toner images (developer images) IMG of the respective colors using the corresponding toners T1 of the respective colors, that is, black toner, yellow toner, magenta toner, and cyan toner. Is. In the image forming unit 30, for example, the image forming unit 30K, the image forming unit 30Y, the image forming unit 30M, and the image forming unit 30C are arranged in this order from the upstream along the transport direction F. The four image forming units 30K, 30Y, 30M, and 30C have substantially the same configuration except that the types of the toner T1 are different. Therefore, in this specification, the image forming unit 30K will be described as a representative of the four image forming units 30K, 30Y, 30M, and 30C, and the four image forming units 30K, 30Y, 30M, and 30C may be used as necessary. A distinction will be described.

  2 to 4, for example, the image forming unit 30K includes a developing unit 30A, a toner cartridge 30B provided above the developing unit 30A, and a side frame 30S provided on the side surfaces of the developing unit 30A and the toner cartridge 30B. have. The toner cartridge 30B is separate from the developing unit 30A and the side frame 30S, and is configured to be detachable from the developing unit 30A and the side frame 30S, for example, as shown in FIGS. FIG. 3 is a perspective view showing the appearance of the image forming unit 30K, and shows a state in which the toner cartridge 30B is mounted on the developing unit 30A and the like. On the other hand, FIG. 4 is an exploded perspective view showing the appearance of the image forming unit 30K in a state where the toner cartridge 30B is separated from the developing unit 30A and the like.

  As shown in FIG. 2, the developing unit 30A includes a cover 31, a photosensitive drum 32 surrounded by the cover 31, a charging roller 33, a developing roller 35, a supply roller 36, a cleaning blade 37, a waste toner conveying spiral 38, and A doctor blade 39 and an LED (Light Emitting Diode) head 34 provided so as to be exposed to the photosensitive drum 32 from the outside of the cover 31 are provided. The photosensitive drum 32, the charging roller 33, the developing roller 35, the supply roller 36, and the waste toner conveying spiral 38 are substantially cylindrical members (rotating bodies) that can rotate around a rotation shaft portion extending in the width direction (Y-axis direction). It is. Further, the toner cartridge 30B accommodates toner T1 and waste toner T2 therein. The developing unit 30A is a specific example corresponding to the “developing unit” of the present invention. The detailed configuration of the image forming unit 30K will be described later.

(Transfer section 40)
The transfer unit 40 is also called a transfer belt unit. The transfer unit 40 includes a transfer belt 41, a driving roller 42 that drives the transfer belt 41, an idle roller 43 that is a driven roller, and a transfer roller 44 that is disposed to face the photosensitive drum 32 with the transfer belt 41 interposed therebetween. And have. Each of the drive roller 42 and the idle roller 43 is a substantially cylindrical member that can rotate around a rotation shaft portion extending in the width direction. The transfer unit 40 transports the medium M transported from the transport unit 20 along the transport direction F, and the toner image IMG formed in each of the image forming units 30K, 30Y, 30M, and 30C on the surface of the medium M. This is a mechanism for transferring images sequentially.

  The transfer belt 41 is an endless elastic belt made of a resin material such as polyimide resin. The transfer belt 41 is stretched (strung) by a drive roller 42 and an idle roller 43. The drive roller 42 is rotationally driven in the direction in which the medium M is transported in the transport direction F based on the control of the control unit 70, and circulates and rotates the transfer belt 41. The drive roller 42 is disposed upstream of the image forming units 30K, 30Y, 30M, and 30C. The idle roller 43 adjusts the tension applied to the transfer belt 41 by the urging force of the urging member. The idle roller 43 rotates in the same direction as the drive roller 42, and is disposed downstream of the image forming unit 30K.

  The transfer roller 44 electrostatically transfers the toner image formed in the image forming unit 30 </ b> K onto the medium M while rotating the medium M along the transport direction F by rotating in the direction opposite to the photosensitive drum 32. It is a member for. The transfer roller 44 is made of, for example, a foaming semiconductive elastic rubber material.

(Fixing unit 50)
The fixing unit 50 is a member for fixing the toner image on the medium M by applying heat and pressure to the toner image transferred onto the medium M that has passed through the transfer unit 40. The fixing unit 50 includes, for example, an upper roller 51 and a lower roller 52.

  Each of the upper roller 51 and the lower roller 52 includes a heat source that is a heater such as a halogen lamp inside, and functions as a heating roller that applies heat to the toner image on the medium M. The upper roller 51 is configured to rotate in a direction in which the medium M is transported in the transport direction F under the control of the control unit 70. The heat sources in the upper roller 51 and the lower roller 52 are supplied with a bias voltage controlled by the control unit 70 and control the surface temperatures of the upper roller 51 and the lower roller 52. The lower roller 52 is disposed to face the upper roller 51 so that a pressure contact portion is formed between the lower roller 52 and functions as a pressure roller that applies pressure to the toner image on the medium M. To do. The lower roller 52 may have a surface layer made of an elastic material.

(Medium discharge unit 60)
The medium discharge unit 60 discharges the medium M on which the toner image is fixed by the fixing unit 50 to the outside. The medium discharge unit 60 includes, for example, transport rollers 61 and 62. The transport rollers 61 and 62 discharge the medium M to the outside through the transport path and stock it on the external stacker 100A. The transport rollers 61 and 62 are configured to rotate in a direction in which the medium M is transported in the transport direction F under the control of the control unit 70.

[Configuration of Image Forming Unit 30K]
Next, a detailed configuration of the image forming unit 30K will be described mainly with reference to FIG.

(Configuration of developing unit 30A)
The developing unit 30A is provided with a toner storage chamber 31V that is a space surrounded by the cover 31 and an opening 31K formed in the upper part of the cover 31. The toner T1 supplied from the toner cartridge 30B through the opening 31K is temporarily stored in the toner storage chamber 31V. The toner storage chamber 31V is provided with a remaining amount sensor SR2 for detecting the remaining amount level of the toner T1. The toner storage chamber 31V is a specific example corresponding to the “developer storage chamber” of the present invention, and the remaining amount sensor SR2 is a specific example corresponding to the “second detection unit” of the present invention.

  The photosensitive drum 32 is a cylindrical member capable of carrying an electrostatic latent image on the surface (surface layer portion), and is configured using a photosensitive member (for example, an organic photosensitive member). Specifically, the photosensitive drum 32 has a conductive support and a photoconductive layer covering the outer periphery (surface) thereof. The conductive support is made of, for example, a metal pipe made of aluminum. The photoconductive layer has, for example, a structure in which a charge generation layer and a charge transport layer are sequentially stacked. The photosensitive drum 32 rotates at a predetermined peripheral speed in the direction in which the medium M is transported in the transport direction F (the direction of the arrow R32 illustrated in FIG. 2) by the power of the drive unit 71 controlled by the control unit 70. It is supposed to be. The developing unit 30A is further provided with a counter SR1 that counts the operating amount (for example, the number of rotations) of the photosensitive drum 32. The counter SR1 is a specific example corresponding to the “first detection unit” of the present invention.

  The charging roller 33 is a member (charging member) that charges the surface (surface layer portion) of the photosensitive drum 32, and is disposed in contact with the surface (circumferential surface) of the photosensitive drum 32. The charging roller 33 has, for example, a metal shaft and a semiconductive rubber layer (for example, a semiconductive epichlorohydrin rubber layer) covering the outer periphery (surface) thereof. The charging roller 33 is rotated in the same direction as the photosensitive drum 32 by the power of the drive unit 71 controlled by the control unit 70, for example.

  The LED head 34 is an exposure device that forms an electrostatic latent image on the surface (surface layer portion) of the photosensitive drum 32 by exposing the surface of the photosensitive drum 32. The LED head 34 has a plurality of LED light emitting units arranged in the width direction with respect to one photosensitive drum 32. Each LED light emitting unit includes, for example, a light source such as a light emitting diode that emits irradiation light, and a lens array that forms an image of the irradiation light on the surface of the photosensitive drum 32.

  The developing roller 35 is a member that carries the toner T1 that develops the electrostatic latent image on the surface, and is disposed so as to be in contact with the surface (circumferential surface) of the photosensitive drum 32. The developing roller 35 has, for example, a metal shaft and a semiconductive urethane rubber layer covering the outer periphery (surface). The developing roller 35 is rotated at a predetermined peripheral speed in the direction opposite to the photosensitive drum 32 (direction of arrow R35) by the power of the driving unit 71 controlled by the control unit 70.

  The supply roller 36 is a member (supply member) for supplying the toner T1 stored in the toner storage chamber 31V to the developing roller 35, and is disposed so as to be in contact with the surface (circumferential surface) of the developing roller 35. ing. The supply roller 36 has, for example, a metal shaft and a foamable silicone rubber layer covering the outer periphery (surface) thereof. The supply roller 36 is rotated in the direction opposite to the developing roller 35 (direction of arrow R36) by the power of the drive unit 71 controlled by the control unit 70.

  The cleaning blade 37 scrapes off the toner T1 remaining on the surface of the photosensitive drum 32. The cleaning blade 37 is made of, for example, a flexible rubber material or a plastic material.

  The waste toner conveying spiral 38 is a member in which, for example, spiral blades are erected around the shaft, and is a member that is rotated by the power of the drive unit 71 controlled by the control unit 70. The waste toner conveying spiral 38 rotates by itself to convey the toner scraped off by the cleaning blade 37 (hereinafter referred to as waste toner T2) in the direction (+ Y direction) indicated by the arrow Y28 in FIG. To function. The waste toner conveying spiral 38 is a specific example corresponding to the “developer discharging portion” of the present invention.

  The doctor blade 39 is a member that regulates the amount of toner T1 that adheres to the surface of the developing roller 35.

(Configuration of side frame 30S)
As shown in FIGS. 3 and 4, the side frame 30S includes a housing 90 attached to both ends of the developing unit 30A and the toner cartridge 30B. Inside the housing 90, a mechanism for conveying the waste toner T2 from the developing unit 30A to the toner cartridge 30B is provided.

  FIG. 5 is a side view showing the appearance of the image forming unit 30K. FIG. 6 is a side view showing the appearance of the developing unit 30A and the side frame 30S in the image forming unit 30K. That is, FIG. 6 shows a state (separated state) in which the toner cartridge 30B is separated from the developing unit 30A and the side frame 30S. FIG. 7 is a perspective view showing the internal configuration of the side frame 30S.

  As shown in FIG. 5, the housing 90 has a protrusion 90T that protrudes in the −Y direction toward the toner cartridge 30B. The protruding portion 90T is inserted into the receiving port 85 (rearly described) in the toner cartridge 30B and functions as a waste toner discharging portion. The protrusion 90T has, for example, a substantially cylindrical hollow structure, and an opening 90K1 is provided on a side surface thereof. A waste toner conveying spiral 91 extending in the Y-axis direction is accommodated in the protrusion 90T so as to be rotatable about the shaft 91J. The waste toner transport spiral 91 transports the waste toner T2 transported by the waste toner transport spiral 38 in the −Y direction inside the protrusion 90T and discharges it from the opening 90K1. The waste toner conveying spiral 91 is a spiral blade disposed around a shaft that rotates about a shaft 91J. The waste toner conveyance spiral 91 is rotated by the power transmitted from the drive unit 71.

  With reference to FIG. 7, the internal structure of the housing | casing 90 is demonstrated in detail. Inside the housing 90 of the side frame 30S, for example, an endless collection belt 92 having an uneven surface, a pulley 93 that guides the collection belt 92, an action gear 94, and a drive gear 95 are provided. Yes. The working gear 94 rotates in the direction of the arrow R94 in FIG. 7 by the rotation of the driving gear 95 that receives the power from the driving unit 71. The collection belt 92 is provided so as to rotate in the direction of the arrow R92 in FIG. The pulley 93 rotates following the collection belt 92 and assists the stable rotation operation of the collection belt 92. An opening 90 </ b> K <b> 2 that receives the waste toner T <b> 2 transported from the waste toner transport spiral 38 is further provided in the lower portion of the housing 90. In the side frame 30 </ b> S, the waste toner T <b> 2 input from the opening 90 </ b> K <b> 2 is locked to the uneven surface of the collection belt 92, conveyed upward by the rotation operation of the collection belt 92, and dropped onto the waste toner conveyance spiral 91. It is supposed to be. The waste toner T2 dropped on the waste toner transport spiral 91 is transported in the −Y direction by the rotation operation of the waste toner transport spiral 91, and enters the waste toner storage chamber 30B2 from the receiving port 85. Here, the waste toner conveyance spiral 91, the recovery belt 92, the pulley 93, the operation gear 94, the drive gear 95, and the waste toner storage chamber 30B2 of the toner cartridge 30B are developed by a waste toner conveyance spiral 38 as a developer discharge unit. This corresponds to a specific example of the “developer recovery unit” of the present invention that recovers waste toner T2 discharged from 30A.

(Configuration of toner cartridge 30B)
Next, the detailed configuration of the toner cartridge 30B will be described with reference to FIG. The toner cartridge 30B has a toner storage chamber 30B1 and a waste toner storage chamber 30B2 as two spaces separated from each other by a wall W. The toner storage chamber 30B1 stores the toner T1 before use of each color described above. Specifically, black toner is stored in the toner storage chamber 30B1 of the image forming unit 30K, yellow toner is stored in the toner storage chamber 30B1 of the image forming unit 30Y, and the toner storage chamber 30B1 of the image forming unit 30M. Magenta toner is accommodated, and cyan toner is accommodated in the toner storage chamber 30B1 of the image forming unit 30C. Here, the toner storage chamber 30B1 corresponds to a specific example of “developer supply unit” of the present invention, and the waste toner storage chamber 30B2 corresponds to a specific example of “storage chamber” of the present invention. In the present embodiment, the toner storage chamber 30B1 and the waste toner storage chamber 30B2 are integrally formed. However, in the present invention, they may be provided separately.

  An opening 83 communicating with the opening 31K of the developing unit 30A is provided at the bottom of the toner storage chamber 30B1 in the toner cartridge 30B. The opening 83 can be shifted between an open state and a closed state by a shutter member 82 that is formed to be rotatable in the direction of an arrow R82, for example, around a rotation axis along the Y-axis direction. The waste toner storage chamber 30 </ b> B <b> 2 is provided with a receiving port 85, and the waste toner T <b> 2 is carried by the waste toner conveying spiral 91 from the receiving port 85. Further, the waste toner storage chamber 30B2 is provided with a waste toner conveyance spiral 84 that rotates, for example, in the direction of arrow R84. Thus, the waste toner T2 carried into the waste toner storage chamber 30B2 is sequentially transported in the −Y direction inside the waste toner storage chamber 30B2 by the waste toner transport spiral 84.

[Operation and Action]
(A. Basic operation)
In the image forming apparatus 1, the toner image is transferred to the medium M (printing operation is performed) as follows.

  When print image data and a print command are input to the control unit 70 from an external device such as a PC with respect to the activated image forming apparatus 1, the control unit 70 starts a print operation of the print image data in accordance with the print command. Let

  For example, as shown in FIG. 1, the medium M accommodated in the cassette 11 is picked up one by one from the uppermost portion by the pickup roller 12, and the downstream conveying portion is corrected while the skew is corrected by the feed roller 13 and the retard roller 14. It goes out to 20. Next, the medium M is conveyed to the image forming unit 30 by the two pairs of registration rollers 21 and 22. In the image forming unit 30, the toner image IMG is transferred onto the medium M as follows.

  In the image forming unit 30, each color toner image IMG is formed by the following electrophotographic process in accordance with the print command of the control unit 70. Specifically, the control unit 70 puts the toner T1 stored in the toner storage chamber 30B1 of the toner cartridge 30B into the toner storage chamber 31V inside the cover 31 of the developing unit 30A. At that time, the control unit 70 activates the driving unit 71 to rotate the photosensitive drum 32 in the direction of the arrow R32 at a constant speed. Along with this, the charging roller 33, the developing roller 35, the supply roller 36 and the like also start rotating in a predetermined direction.

  On the other hand, the control unit 70 applies a predetermined voltage to the charging roller 33 for each color to uniformly charge the surface of the photosensitive drum 32 for each color. Next, the control unit 70 activates the LED head 34, irradiates each color photosensitive drum 32 with light corresponding to the color component of the print image based on the image signal, and forms an electrostatic latent image on the surface of each color photosensitive drum 32. Form each one.

  The toner T1 is supplied to the developing roller 35 via the supply roller 36 and is carried on the surface of the developing roller 35. The developing roller 35 attaches the toner T1 to the electrostatic latent image formed on the photosensitive drum 32 to form a toner image IMG. Further, a predetermined voltage is applied to the transfer roller 44 in the transfer unit 40, and an electric field is generated between the photosensitive drum 32 and the transfer roller 44. When the medium M travels between the photosensitive drum 32 and the transfer roller 44 in this state, the toner image IMG formed on the photosensitive drum 32 is transferred onto the medium M.

  Thereafter, the toner image IMG on the medium M is fixed to the medium M by applying heat and pressure in the fixing unit 50. Finally, the medium M on which the toner image IMG is fixed by the medium discharge unit 60 is discharged to the stacker 100A outside the image forming apparatus 1. Thus, the printing operation for the medium M is completed.

(B. About the exchange preparation operation of the developing unit 30A)
In the image forming apparatus 1, when the control unit 70 determines that the developing unit 30 </ b> A needs to be replaced due to its life or the like, the following replacement preparation operation for the developing unit 30 </ b> A is automatically performed according to an instruction from the control unit 70. Hereinafter, the replacement preparation operation of the developing unit 30A will be described with reference to FIGS.

  FIG. 8 is a flowchart illustrating an example of the replacement preparation operation of the developing unit 30 </ b> A in the image forming apparatus 1. In the image forming apparatus 1, first, a printing operation is executed as described above (step S101). During this printing operation, the counter SR1 counts the number of rotations of the photosensitive drum 32, and the control unit 70 stores the accumulated data.

  Next, the image forming apparatus 1 repeats the printing operation to determine whether or not the integrated operation amount of the developing unit 30A has reached the reference value. Specifically, the control unit 70 determines whether or not the integrated value of the rotation speed of the photosensitive drum 32 has reached the reference value (step S102). Therefore, when it is determined that the integrated value of the rotational speed of the photosensitive drum 32 has not reached the reference value (step S102N), the state returns to a state where the printing operation can be performed again. On the other hand, when it is determined that the integrated value of the rotation speed of the photosensitive drum 32 has reached the reference value (step S102Y), the control unit 70 displays on the display unit 80 that it is time to replace the developing unit 30A (step S103). ). By repeatedly using the photosensitive drum 32, for example, the photosensitive member in the surface layer portion on which the electrostatic latent image should be carried may deteriorate, and a clear printed image may not be obtained. By setting an upper limit value (reference value) within a range in which a good print image can be obtained with respect to the integrated value of the rotational speed of the photosensitive drum 32, such a situation can be prevented in advance. In addition, although the integrated value of the rotation speed of the photosensitive drum 32 is illustrated as the integrated operation amount of the developing unit 30A, the present invention is not limited to this, and the usage amount of other components and the change of parameters may be used. For example, the number of printed sheets in the image forming apparatus 1 may be used as the integrated operation amount of the developing unit 30A.

  Next, it is determined whether the remaining amount of toner T1 in the toner storage chamber 31V of the developing unit 30A is sufficient. Specifically, the remaining amount sensor SR2 detects the remaining amount level of the toner T1 in the toner storage chamber 31V, and controls whether or not the remaining amount of toner T1 suitable for execution of the printing operation exists in the toner storage chamber 31V. The unit 70 determines (step S104). Before performing step S104, the shutter member 82 may be operated to close the opening 83 so that the supply of the toner T1 from the toner storage chamber 30B1 to the toner storage chamber 31V may be shut off.

  If it is determined in step S104 that the remaining amount of toner T1 is sufficient (step S104Y), the process returns to a state where the printing operation can be performed again. On the other hand, when it is determined that the remaining amount of toner T1 is not sufficient (step S104N), the printing operation is stopped by the control unit 70 (step S105), and the control unit 70 cannot perform the printing operation in the image forming apparatus 1. A message to the effect is displayed on the display unit 80 (step S106). However, even if the printing operation is not possible, the toner T1 slightly remains in the toner storage chamber 31V as shown in FIG.

  After step S106, the control unit 70 executes a discharge operation for forcibly discharging the toner T1 slightly remaining in the toner storage chamber 31V (step S107). An example of the discharging operation is shown in FIG. FIG. 10 is a flowchart illustrating an example of an operation of discharging the toner T1 in the developing unit 30A in the image forming unit 30K. As shown in FIG. 10, first, the drive unit 71 is activated by a command from the control unit 70 to rotate the photosensitive drum 32 and the like (step S201). Next, the control unit 70 applies a predetermined voltage to the charging roller 33 to uniformly charge the surface of the photosensitive drum 32 (step S202). Further, the surface of the photosensitive drum 32 is uniformly exposed by the LED head 34, and an electrostatic latent image for discharging operation is formed on the surface of the photosensitive drum 32 (different from that during normal printing) (step S203). The toner T1 slightly remaining in the toner storage chamber 31V is supplied to the developing roller 35 via the supply roller 36 and is carried on the surface of the developing roller 35. The developing roller 35 adheres the toner T1 to the electrostatic latent image formed on the photosensitive drum 32, and forms a uniform toner image IMG (step S204). At this time, no charge is applied to the transfer roller 44. Therefore, no electric field is generated between the photosensitive drum 32 and the transfer roller 44, and the toner image IMG is not transferred to the transfer belt 41. Therefore, the toner T1 adhering to the electrostatic latent image on the photosensitive drum 32 is scraped off as it is by the cleaning blade 37 onto the waste toner transport spiral 38 as the waste toner T2, and is transported to the side frame 30S by the waste toner transport spiral 38. (Step S205). After that, due to the rotation of the drive gear 95 that receives the power of the drive unit 71, the waste toner T2 is sequentially transported by the collection belt 92 and the waste toner transport spiral 91 inside the housing 90 of the side frame 30S. Then, the toner is carried into the waste toner storage chamber 30B2, and the discharging operation is completed (step S206). As a result of these series of discharge operations, the toner T1 hardly remains in the toner storage chamber 31V as shown in FIG. 11, and the toner is stored in the waste toner storage chamber 30B2 as waste toner T2.

  After the discharge operation in step S107 is completed, it is checked if necessary by the remaining amount sensor SR2 whether the toner T1 in the toner storage chamber 31V has been discharged (step S108). When it is determined that the toner T1 remains in the toner storage chamber 31V (step S108N), the discharging operation of the toner T1 is performed again. On the other hand, when it is determined that the discharge of the toner T1 from the toner storage chamber 31V is completed (step S108Y), the display unit 80 is displayed that the developing unit 30A can be replaced (step S109). In the present invention, the determination of the completion of the discharge of the toner T1 is not limited to the case based on the detection by the remaining amount sensor SR2. For example, it may be determined that the discharge of the toner T1 remaining in the toner storage chamber 31V has been completed by performing a discharge time for performing the series of discharge operations in steps S201 to S207 for a certain time. That is, for example, a timer for measuring the discharge time of the waste toner T2 by the waste toner conveyance spiral 38 is further provided, and when the control unit 70 determines that the discharge time has reached a predetermined reference time, the discharge of the waste toner T2 is performed. You may make it complete | finish operation | movement.

  Thus, the replacement preparation operation for the developing unit 30A is completed.

[effect]
As described above, according to the image forming apparatus 1 of the present embodiment, when the integrated operation amount of the developing unit 30A has reached the reference value by the control unit 70 (that is, the product life in the developing unit 30A is temporarily reached). The waste toner conveying spiral 38 and the like discharge the toner T1 remaining in the toner storage chamber 31V to the side frame 30S as waste toner T2. For this reason, at the time of work such as replacement of the developing unit 30A, the toner T1 hardly exists in the toner storage chamber 31V. Accordingly, it is difficult for the toner T1 to be ejected to the outside during work such as replacement of the developing unit 30A. As a result, excellent handleability of the developing unit 30A can be ensured.

<2. Other variations>
While the present invention has been described with reference to the embodiments and modifications, the present invention is not limited to these embodiments and the like, and various modifications can be made.

  For example, in the above-described embodiment, all of the toner T1 remaining in the toner storage chamber 31V is scraped off by the cleaning blade 37, and is transported as waste toner T2 to the waste toner storage chamber 30B2 by the waste toner transport spiral 38 or the like. However, the present invention is not limited to this. For example, while transferring only a part of the toner T1 remaining in the toner storage chamber 31V to the waste toner storage chamber 30B2 as described above, another remaining toner T1 is transferred to the transfer belt 41 as a toner image, and then the transfer belt. The toner image on 41 may be scraped off by another cleaning blade, and the waste toner T2 may be carried into another storage chamber.

  In the above embodiment, the primary transfer type image forming apparatus 1 has been described as an example. However, the present invention can also be applied to a secondary transfer type.

  Further, the series of processes described in the above embodiments may be performed by hardware (circuit) or may be performed by software (program). When performed by software, the software is composed of a group of programs for causing each function to be executed by a computer. Each program may be used by being incorporated in advance in the computer, for example, or may be used by being installed in the computer from a network or a recording medium.

  Moreover, in the said embodiment, although the LED head which has a light emitting diode as a light source was used as an exposure part, you may use a laser element etc. as a light source, for example.

  Further, the present invention is not limited to the case where all the operations described in the above embodiment are performed, and some operations may be lacking. For example, in the flowchart shown in FIG. 8, after step S103, it is possible to proceed to step S105 without performing the determination of step S104. Further, the order of step S102 and step S104 may be reversed.

  Furthermore, in the above-described embodiment and the like, an image forming apparatus having a printing function has been described as a specific example of the “image forming apparatus” in the present invention, but the present invention is not limited to this. That is, in addition to such a printing function, for example, the present invention can also be applied to an image forming apparatus that functions as a multifunction peripheral having a scanning function and a fax function.

  DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus, 10 ... Medium supply part, 11 ... Cassette, 12 ... Pick-up roller, 13 ... Feed roller, 14 ... Retard roller, 20 ... Conveyance part, 21,22 ... Registration roller pair, 30 ... Image formation part, 30K, 30Y, 30M, 30C ... image forming unit, 30A ... developing unit, 30B ... toner cartridge, 30S ... side frame, 30B1 ... toner storage chamber, 30B2 ... waste toner storage chamber, 31 ... cover, 31K ... opening, 31V ... Toner storage chamber, 32 ... photosensitive drum, 33 ... charge roller, 34 ... LED head, 35 ... developing roller, 36 ... supply roller, 37 ... cleaning blade, 38 ... waste toner conveying spiral, 39 ... doctor blade, 40 ... transfer section 41 ... transfer belt, 42 ... drive roller, 43 ... idle roller, 44 ... transfer roller, DESCRIPTION OF SYMBOLS 0 ... Fixing part, 60 ... Medium discharge part, 70 ... Control part, 82 ... Shutter member, 83 ... Opening, 84 ... Waste toner conveyance spiral, 85 ... Receiving port, 90 ... Housing | casing, 90T ... Projection part, 90K1, 90K2 ... Opening, 91 ... Waste toner conveying spiral, 100 ... Case, SR1 ... Counter, SR2 ... Remaining amount sensor.

Claims (10)

A developer supply unit for supplying the developer;
A developer storage chamber for storing the developer supplied by the developer supply section; and a developer discharge section for discharging the developer remaining in the developer storage chamber. A developing section to be formed;
A first detection unit that detects an integrated operation amount of the developing unit;
A control unit that controls the developer discharge unit to discharge the developer from the developer storage chamber when an integrated operation amount of the developing unit detected by the first detection unit reaches a reference value; An image forming unit. The image forming unit according to claim 1, further comprising a developer collecting unit that collects the developer discharged by the developer discharging unit. The image forming unit according to claim 2, wherein the developer recovery unit includes a storage chamber for storing the recovered developer. The image forming unit according to claim 3, wherein the storage chamber is formed integrally with the developer supply unit. The image forming unit according to claim 4, wherein the developer supply unit and the storage chamber are detachably attached to the developing unit. The image forming unit according to claim 1, further comprising a second detection unit that detects a remaining amount of the developer remaining in the developer storage chamber. A display unit;
The image forming unit according to any one of claims 1 to 6, wherein the control unit displays the fact on the display unit after the discharge by the developer discharge unit is completed. A timer for measuring a discharge time by the developer discharge unit;
The image according to any one of claims 1 to 7, wherein when the control unit determines that the discharge time has reached a reference time, the developer discharge operation by the developer discharge unit is terminated. Forming unit. A shutter between the developer storage chamber and the developer supply section that blocks supply of the developer from the developer supply section to the developer storage chamber;
The control unit shuts off the supply of the developer from the developer supply unit to the developer storage chamber by the shutter, and then the developer discharge unit discharges the developer from the developer storage chamber. The image forming unit according to any one of claims 1 to 8. An image forming apparatus comprising the image forming unit according to claim 1.

Images