JP2009092739A - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus having a developer replenishing device, which stably obtains accuracy of detecting presence or absence of developer, so that it can stably replenish a developing device with the developer, when starting up the image forming apparatus, when showing a state where replacement of a toner bottle is displayed, when replacing a developer storing container after outputting many images, and capable of yielding an output image where lowering of image density is suppressed. <P>SOLUTION: The image forming apparatus includes developer discharging means for discharging the developer from the developer storing container, and the developer replenishing device for replenishing the developing device with the developer from the developer storing container. The developer replenishing device includes a hopper part for temporarily storing the developer and a developer conveying part for conveying the developer from the hopper part to the developing device. The apparatus includes control means for actuating a stirring member disposed in the hopper part and stirring the developer while actuating the developer discharging means, for a predetermined time after completing such actuation, and while actuating the developer conveying part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an image forming apparatus having a developer replenishing device that replenishes a developing device such as an electrophotographic copying machine, a facsimile machine, or a printer.

  Image forming apparatuses such as copying machines, facsimile machines, and printers that use electrophotography maintain a constant amount of developer inside the developing apparatus. When the developer is insufficient, the developing apparatus starts from a developer container that stores the developer. The developer is automatically replenished.

  However, the user of the image forming apparatus is not always near the image forming apparatus, and sometimes the developer storage container cannot be replaced even if the developer in the developer storage container runs out.

For this reason, in order not to cause an abnormality in the development density even if the developer in the developer container is exhausted,
A stock portion for temporarily stocking the developer is provided between the developer storage container and the developing device, and when the developer in the developer storage container runs out, the developer is temporarily transferred from the stock portion to the developing device. What is replenished is known.

Specifically, as such a developing device, it has a temporary stock portion (reserve tank) of developer,
A developing device in which a stock section (reservation tank) is divided into two spaces, the developer circulates in these two spaces while being stirred by a stirring means, and the stirred developer is continuously supplied to a developing roll by a paddle wheel. 2. Description of the Related Art Conventionally, an image forming apparatus is known (see, for example, Patent Document 1).
JP-A-3-217879

A developing device of an image forming apparatus described in Patent Document 1 includes a screw that stirs and circulates a developer, a paddle wheel that supplies the developer stirred by the screw to a developing roll, and a developing roll in one housing. Stored in
The screw and the paddle wheel are connected by a gear and are driven by a common drive source.

  Also, a developer presence / absence detection sensor inside the housing is provided at the lower part of the housing to detect the presence / absence of the developer inside the housing.

  For this reason, the screw and the paddle wheel are interlocked even when the developer is not sufficiently spread inside the housing, such as when the image forming apparatus is started up or when the developer container is replaced after continuous mass image output. Will work.

For this reason, when the developer is supplied to the developing device, such as when the developer container is replaced, the developer inside the stock section is sequentially supplied to the developing roll, and the developer inside the stock section (reservation tank) is stored in the stock section. (Reserve tank) may be difficult to circulate,
As a result, the developer surface inside the stock portion (reservation tank) is inclined in the direction in which the paddle wheel side is low.

  Further, since the presence / absence detection sensor of the developer is installed at the above position, there is a possibility that the presence of the developer may be detected even if the screw and the paddle wheel cannot sufficiently circulate the developer. End up.

  Due to the developer surface tilt inside the stock section (reservation tank) and the developer presence / absence detection sensor mounting position, it becomes impossible to supply the required developer to the developing roll, resulting in insufficient density of the output image. There was a problem that it might be.

  In view of the above problems, the present invention can detect the presence / absence of developer even when the image forming apparatus is started up, when a toner bottle is replaced, or when a developer container is replaced after outputting a large amount of images. To provide an image forming apparatus that has a developer replenishing device that can stably replenish developer as a result, and that can stably replenish developer to the developing device and can obtain an output image with reduced image density reduction. And

(1) In an image forming apparatus having a developer discharge means for discharging a developer from a developer storage container and a developer supply device for supplying the developer from the developer storage container to the development device.
The developer replenishing device has a hopper that temporarily stores the developer, and a developer transport unit that transports the developer from the hopper to the developing device,
Control means for operating a stirring member that stirs the developer disposed in the hopper section during the operation of the developer discharging means and for a predetermined time after the completion of the operation and during the operation of the developer transport section. An image forming apparatus comprising:

(2) In an image forming apparatus having a developer discharging means for discharging the developer from the developer storage container and a developer supply device for supplying the developer from the developer storage container to the developing device.
The developer replenishing device includes a hopper portion for temporarily storing the developer, a developer transport portion for transporting the developer from the hopper portion to the developing device, and a developer detection sensor for detecting the presence or absence of the developer in the hopper portion. And having
After the developer container is mounted on the developer discharging means, the developer discharging means is in operation and after the operation is completed until the developer detecting sensor detects the presence of the developer continuously for a predetermined time. A predetermined time and during the operation of the developer transport unit, the stirring member attached to the hopper unit and stirring the developer is operated,
After the developer storage container is mounted on the developer discharge means, after the developer detection sensor detects the presence of the developer for a predetermined time, during the operation of the developer discharge means and the development During the operation of the agent transport unit, the control means for operating the stirring member,
An image forming apparatus comprising:

According to the present invention, the following effects can be obtained:
(1) A developer that transports the developer to the developing device during the operation of the developer discharging means for discharging the developer from the developer storage container, for a predetermined time after the operation is completed, and from a hopper portion that temporarily stores the developer. While the transport unit is operating,
By operating a stirring member that stirs the developer inside the hopper,
Even when the image forming apparatus is started up or when the developer container is replaced after continuous large-volume image output, the presence / absence detection accuracy of the developer can be stably made, and the developer can be replenished stably. As a result, it is possible to provide an image forming apparatus capable of obtaining an output image with reduced image density reduction.

(2) After the developer container is mounted on the developer discharge means, after the developer detection sensor detects the presence of the developer for a predetermined time, the developer discharge means is in operation, and By operating the stirring member during the operation of the developer transport unit,
In addition to the effect described in the above item (1), it is possible to reduce the operation time of the agitating member drive motor after the second replacement of the developer storage container, thereby further saving energy and further improving environmental conservation. A possible image forming apparatus can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings. In addition, the structure of this invention is not limited to the following embodiment, It can change suitably in the technical scope of this invention.

  In addition, if it is the same member, the same part number is attached | subjected common to each figure.

  FIG. 1 is a cross-sectional view showing an embodiment of an image forming apparatus having a developer supply device of the present invention.

  In FIG. 1, the image forming apparatus 1 includes an automatic document feeder 2, an image reading unit 3, a developer supply device 4, an image forming unit 5, a paper feeding unit 6, and a fixing device 38.

  Documents are placed on the document feeder 11 of the automatic document feeder 2 with the image surface facing upward, and are fed one by one by the operation of the feed roller 12.

  The fed document is temporarily stopped by the registration roller 13 and the leading edge is adjusted, and then conveyed to the conveyance drum 14.

  Then, in the process of rotating counterclockwise integrally with the conveying drum surface, the image reading unit 3 as an image reading unit reads the image surface, and then branches off from the drum surface at a substantially half-turned position to the discharge table 15. Discharged.

  In the image reading unit 3, the light source 231 sequentially illuminates the passing document at a position directly below the transport drum 14.

  Then, the original image is reflected by the first mirror unit 23 including the mirror 232 and the second mirror unit 24 including the mirror 241 and the mirror 242 arranged so as to be orthogonal to the moving direction of the original, and the line is passed through the imaging lens 25. The image is formed on the image pickup element 26 and a document image is read.

  When the document is placed on the platen glass 27 and image information is read, it is reflected by the first mirror unit including the movable light source 231a and the first mirror 232a and the second mirror unit including the mirrors 241a and 242a. Similarly, an image is formed on the line-shaped image sensor 26 through the imaging lens 25.

  Image information of the document read by the image reading unit 3 is subjected to image processing by an image processing unit (not shown) and temporarily stored as digital image data in a memory.

  When the image formation is started, the image forming unit 5 as an image forming unit starts to operate, and the digital image data is called from the memory and input to the image writing unit 33.

  A laser beam projected according to digital image data from a laser light emitter (not shown) is sub-scanned with respect to the photosensitive drum 31 by a polygon mirror to form an electrostatic latent image of a document image.

  The electrostatic latent image is reversely developed by the developing device 34 to become a toner image.

  In parallel with this, one of the paper feed cassettes 90, 91, and 92 of the manual paper feed unit 16 as the recording paper supply means or the paper feed unit 6 that stores the recording paper is operated to carry out the recording paper.

  The conveyed recording paper is fed to conveyance rollers 93 and 94 and a registration roller 39 and is fed to the photosensitive drum 31 in synchronization with the toner image on the photosensitive drum 31.

  The toner image on the photosensitive drum 31 is transferred to the recording paper fed by the transfer device 35.

  The recording paper carrying the toner image is neutralized by the static eliminator 36 and separated from the photosensitive drum 31.

  The recording paper carrying the toner image is conveyed to the fixing device 38 by the conveyance belt.

  Next, the toner on the recording paper is fused and fixed by pressure heating of the fixing roller, and the recording paper on which the toner is fixed is discharged to the tray 95.

  On the other hand, the photosensitive drum 31 from which the recording paper has been separated is removed from the residual potential, and then the residual toner is removed and cleaned by the cleaning device 37, and the next image forming process is started.

  In this way, image formation is performed, and the consumed developer is supplied from the developer storage container 60 to the developing device 34 via the developer supplying device 4.

  Note that a toner can be suitably used as the developer.

  The developer storage container 60 storing the toner is attached to the developer discharge means 70 for discharging the developer from the developer storage container 60. When the developer runs out, the user replaces the developer storage container 60. It can be done.

  The developer supply device 4 is located between the developer discharge means 70 for discharging the developer from the developer container 60 and the developing device 34 in the flow of the developer.

  The developer supply device 4 includes a hopper 41 that temporarily stores the developer and a developer transport unit 51 that transports the developer from the hopper 41 to the developing device 34.

  FIG. 2 is a cross-sectional view of the developer supply device as viewed from the side.

  2 is a view of the developer supply device 4 and the like viewed from the same direction as FIG.

The developer storage container 60 has a spiral (not shown) protruding inward of the container, and a developer outlet 61.
By rotating the developer storage container 60, the developer G in the container is pushed out along the spiral and discharged from the discharge port 61.

  The developer discharge means 70 has a container rotation motor 71 that rotates the developer storage container 60. The developer storage container 60 is rotated by the operation of the container rotation motor 71, and the developer G is discharged from the developer storage container 60. The toner is discharged toward the inlet 46 of the developer supply device 4 (in the direction of arrow A).

  Further, the developer discharging means 70 has a plurality of rollers that are driven to rotate by a container rotation motor 71, and the developer storage container 60 is placed on the plurality of rollers, so that the developer rotation container 71 can move the developer. The storage container 60 can be rotated.

  In other words, the developer discharge means 70 allows the developer container 60 to be attached and detached.

  The developer discharging means 70 is located on the developer supply device 4, and the insertion port 46 is opened above the hopper portion 41 of the housing 40.

  The developer charging position from the developer discharging means 70 may be an upper part of the first storage space 42a described below. In this case, the charging port 46 opens to the upper part of the first storage space 42a of the housing 40. Let

  As described above, the developer supply device 4 includes the hopper portion 41 and the developer transport portion 51, and the hopper portion 41 and the developer transport portion 51 are accommodated in the housing 40.

The hopper part 41 has a plurality of storage spaces 42 (first storage space 42a, second storage space 42b),
In the first storage space 42a, a first stirring member 43a for stirring the developer is rotatably provided.
In the second storage space 42b, a second stirring member 43b for stirring the developer is rotatably provided.

  The first agitation member 43a and the second agitation member 43b are connected by a gear or the like which will be described later, and are rotationally driven by an agitation member drive motor which will be described later.

  In the developer transport section 51, a transport member 52 that transports the developer toward the developing device 34 is rotatably provided.

  The transport member 52 is rotationally driven by a transport member drive motor described later.

  That is, the developer storage container 60, the first stirring member 43a and the second stirring member 43b, and the transport member 52 are driven by independent drive sources.

  The developer discharged from the developer storage container 60 is moved into the first storage space 42a and the second storage space 42b by the operation (rotation) of the first stirring member 43a and the second stirring member 43b. Circulate with stirring.

  Then, part of the circulating developer moves to the developer transport unit 51, and the moved developer is transported toward the discharge port 53 to the developing device 34 by the operation (rotation) of the transport member 52, and the discharge port 53. To the developing device 34.

  The developer detection sensor 45 is attached to the side surface of the housing 40 on the first storage space 42 a side, and detects the developer in the hopper portion 41.

  Note that the position in the height direction (the vertical direction in the figure) of the position at which the developer detection sensor 45 detects the developer is slightly above (for example, about 1 to 2 mm) from the upper end 56 of the conveying member 52.

As a result, during normal operation (for example, other than the time when the developer inside the developer supply device 4 is slanted and is not stable immediately after replacement of the developer container 60), the developer container 60 Even if there is no developer inside and the developer detection sensor 45 cannot detect the developer,
By supplying the developer temporarily stored in the developer replenishing device 4, particularly the hopper 41, to the developing device 34, thousands of copies can be continuously made.

  As a result, the developer temporarily stored in the developer supply device 4 can be stably supplied to the developing device 34.

  FIG. 3 is a cross-sectional view of the developer supply device as viewed from above.

Arrow B indicates the direction in which the developer is transported inside the first storage space 42a, arrow C indicates the direction in which the developer is transported inside the second storage space 42b,
An arrow D indicates a direction in which the developer is transported inside the developer transport unit 51.

  A loading port 46 (one-dot chain line) through which the developer discharged from the developer container is introduced into the developer supply device 4 is located upstream of the developer detection sensor 45.

  The first stirring member 43a is rotationally driven in the direction of arrow E by a stirring member drive motor 44 through a gear.

  The first agitation member 43 a and the second agitation member 43 b are constituted by helical screws having the same pitch, and are connected by a gear 47 and a gear 48.

  For this reason, the first stirring member 43a and the second stirring member 43b are rotated in opposite directions to convey the developer in opposite directions (arrows B and C), respectively.

  Then, the developer circulates between the first storage space 42a and the second storage space 42b as the developer passes over the missing portions 49a and 49b of the partition 49.

  The transport member 52 of the developer transport section 51 is rotationally driven by a transport member drive motor 54 via a gear.

  Then, a part of the developer circulating in the hopper 41 moves over the partition 55 and moves to the developer transport unit 51, and is transported in the direction of arrow D by the transport member 52 constituted by the second spiral screw.

  Note that the second spiral screw may be a spiral screw having a smaller diameter than the spiral screw that constitutes the first stirring member 43a and the second stirring member 43b.

  FIG. 4 is a diagram showing the state of the developer in the developer supply device by replacing the developer storage container.

  FIG. 4A is a diagram illustrating a relationship between the developer and the developer detection sensor in a normal state, and FIG. 4B is a diagram illustrating a relationship between the developer and the developer detection sensor after replacement of the developer storage container. It is.

  In FIG. 4A, at the time of normal operation (for example, other than the time when the developer surface inside the developer supply device 4 is inclined and not stable immediately after replacement of the developer container 60). The surface G1 of the developer is almost flat.

  Therefore, the amount of developer in the developer supply device 4 can be accurately detected, and the first stirring member 43a and the second stirring member 43b can satisfactorily stir and circulate the developer. Yes.

  Further, the transport member 52 can also transport the developer satisfactorily.

  In FIG. 4B, development is performed at times other than normal operation (for example, when the developer inside the developer supply device 4 is slanted and not stable immediately after replacement of the developer container 60). The surface G2 of the developer is slanted so that the hopper portion 41 receiving the developer supply is high and the developer transport portion 51 is low.

  For this reason, the amount of developer inside the developer supply device 4 cannot be detected accurately.

  Specifically, since the developer position on the hopper portion 41 side is high, even if the developer detection sensor 45 detects the developer, the developer position is low on the developer transport portion 51 side. There is a possibility that the conveyance of the developer may be hindered.

  In such a case, the developer replenishment to the developing device 34 is not in time, resulting in insufficient image density.

  Hereinafter, control for obtaining a normal image density by the developer replenishing device 4 even at times other than the normal operation will be described.

  FIG. 5 is a block diagram relating to control of the developer supply device and the image forming apparatus.

  The image forming apparatus includes a control unit 100, an operation panel 110, an image reading unit 3, an automatic document feeder 2, an image forming unit 5, a developer supply device 4, a paper feeding unit 6, a fixing device 38, and a communication unit 111. is doing.

  The control means 100 counts how many times the developer is stirred after the CPU (Central Processing Unit) 101, RAM 102, ROM 103, I / O controller 104, and developer container are replaced (operation of the stirring member drive motor 44). Counter 106 and a bus 105 interconnecting them.

  The I / O controller 104 controls the operation panel 110 to the communication unit 111 and the like under the control of the CPU 101.

  The ROM 103 preliminarily controls a program for controlling the entire image forming apparatus, an image formation start switch, a paper cassette selection switch for selecting a paper cassette, screen display information on a screen for displaying the status of the apparatus, and the like. Is remembered.

  The program, screen display information, and the like stored in the ROM 103 are stored in the RAM 102 by the CPU 101, read out as necessary, and control described later is performed.

  The operation panel 110 has a touch panel 114, and displays an operation switch screen such as a start switch and a device status screen on the touch panel 114 via the I / O controller 104 under the control of the control unit 100.

  In addition, operation information on various operation switch screens displayed on the touch panel 114 is input to the control unit 100.

  When the activation information is input from the operation panel 110 via the I / O controller 104 under the control of the control unit 100, the automatic document feeder 2 conveys the document.

  Under the control of the control unit 100, the image reading unit 3 reads a document image of a document transported by the automatic document transport device 2 via the I / O controller 104 and inputs document image information to the control unit 100.

  Then, the control unit 100 processes the document image information read by the image reading unit 3 into digital image information, and stores the digital image information in, for example, an HDD (hard disk drive) or RAM 102 (not shown).

  The image forming unit 5 reads digital image information from, for example, the HDD or the RAM 102 via the I / O controller 104 under the control of the control unit 100, and places a toner image on the photoconductor based on the read digital image information. Form.

  Then, based on the paper feed cassette information input from the operation panel 110, the toner image is transferred onto the paper fed from the paper feed cassette.

  The paper feeding unit 6 feeds paper from a predetermined paper feeding cassette via the I / O controller 104 under the control of the control means 100.

  The developer supply device 4 rotates the stirring member drive motor 44 that rotates the first stirring member 43a and the second stirring member 43b, the developer detection sensor 45, and the transport member 52 of the developer transport section 51. A conveyance member drive motor 54 to be driven and a container rotation motor 71 to rotationally drive the developer storage container 60 are provided.

Then, the developer in the hopper 41 is agitated and circulated by turning on and off the agitating member drive motor 44 via the I / O controller 104 under the control of the control means 100.
The developer in the developer transport section 51 is transported to the developing device 34 by turning on / off the transport member drive motor 54,
The developer is put into the hopper 41 from the developer container 60 by turning on / off the container rotation motor 71.

  Further, the developer detection sensor 45 inputs developer detection information to the control means 100.

  The fixing device 38 includes a drive motor 382 that rotationally drives the heating roller 381 and a heater lamp 383 that heats the heating roller 381.

  Then, the temperature of the heating roller 381 is adjusted by turning on / off the heater lamp 383 and the heating roller 381 is rotated by turning on / off the driving motor 382 via the I / O controller 104 under the control of the control means 100. Is called.

  The communication unit 111 is connected to an external PC (personal computer), an image forming apparatus, or a server 113 via a network 112 or the like, and these are connected to the digital image via the I / O controller 104 under the control of the control unit 100. Send and receive information such as data.

  The control means 100 stores the digital image data received by the communication means 111 in the HDD or the like.

  Hereinafter, a control method of the developer supply device and the image forming apparatus will be described.

  Unless otherwise specified, the following control is performed by the control means 100.

  A control flow relating to the developer replenishing apparatus will be described below. A program of the following flow is stored in the ROM 103, and is stored in the RAM 102 and executed by the CPU 101 as necessary.

  Note that the container rotation motor 71 and the conveying member drive motor 54 are detected by a developer detection sensor (not shown) disposed in the developing device 34 by a program for controlling the entire image forming apparatus, as is normally performed. ON / OFF based on information.

  FIG. 6 is a basic flowchart regarding control of the developer replenishing device, particularly control of the stirring member driving motor of the hopper.

  In this flow, the operations of the first stirring member 43a and the second stirring member 43b related to the replenishment of the developer are performed during the operation of the transport member 52 of the developer transport unit 51 and the container rotation of the developer storage container 60. During the operation of the motor 71 and within α hours after the completion of the operation.

1. Determination of developer container operation (during operation + α after operation) Step S101
The operating state of the container rotation motor 71 that rotationally drives the developer container 60 is checked to determine whether it is operating or within a predetermined time α after completion of the operation.

  If it is within the predetermined time α after the operation or completion of the operation (Yes), the process proceeds to the next step. If not within the predetermined time α after the operation or the operation is completed (No), the process proceeds to Step S103.

  Here, the predetermined time α is preferably 4 to 8 seconds. If the predetermined time α is shorter than this, the developer is not stabilized and the detection accuracy of the developer is lowered, and if it is longer, the productivity is lowered.

2. Stirring member drive motor ON Step S102
The stirring member drive motor 44 that rotationally drives the first stirring member 43a and the second stirring member 43b of the developer supply device 4 is turned on,
The developer in the first storage space 42a and the second storage space 42b is stirred and circulated, and the process proceeds to the end.

3. Judgment of developer conveyance section operation (during operation) Step S103
The operating state of the conveying member driving motor 54 that rotates the conveying member 52 of the developer conveying portion 51 is checked to determine whether or not it is operating.

  And if it is in operation (Yes), it will progress to Step S102, and if it is not in operation (No), it will progress to the next step.

4). Stirring member drive motor OFF Step S104
The stirring member drive motor 44 that rotationally drives the first stirring member 43a and the second stirring member 43b of the developer supply device 4 is turned OFF,
Stirring / circulation of the developer in the first storage space 42a and the second storage space 42b is stopped, and the process proceeds to the end.

  FIG. 7 is a timing chart of supplementary explanation for the flow shown in FIG.

This chart conceptually shows the ON / OFF control of the stirring member drive motor 44.
The ON / OFF timing of the container rotation motor 71 and the ON / OFF timing of the conveying member drive motor 54 mean that the timing is ON / OFF at that timing.

  The horizontal axis shows the passage of time.

  The vertical axis indicates ON / OFF of the container rotation motor 71, the conveyance member drive motor 54, and the stirring member drive motor 44.

  1. When the conveying member driving motor 54 is turned on at timing T1, the stirring member driving motor 44 is turned on.

  Then, the agitating member driving motor 44 is turned off by turning off the conveying member driving motor 54.

  2. When the container rotation motor 71 is turned on at timing T2, the stirring member drive motor 44 is turned on.

  Then, the stirring member drive motor 44 is turned off after a predetermined time α from the turning-off of the container rotation motor 71 (one-dot chain line).

  3. When the container rotation motor 71 is turned on at timing T3, the stirring member drive motor 44 is turned on.

  And if the conveyance member drive motor 54 is turned ON at timing T4 while the container rotation motor 71 is ON, the stirring member drive motor 44 is continuously turned ON.

  Since the conveying member drive motor 54 is within a predetermined time α after the container rotation motor 71 is turned off, the stirring member drive motor 44 is continuously turned on.

  The stirring member drive motor 44 is turned off after a predetermined time α after the container rotation motor 71 is turned off (one-dot chain line).

  4). When the conveying member driving motor 54 is turned on at timing T5, the stirring member driving motor 44 is turned on.

  When the container rotation motor 71 is turned on at timing T6 while the transport member drive motor 54 is on, the stirring member drive motor 44 is continuously turned on.

  Since the transport member drive motor 54 is turned off before the container rotation motor 71 is turned off, the stirring member drive motor 44 is turned off after a predetermined time α after the container rotation motor 71 is turned off.

  5). When the container rotation motor 71 is turned on at timing T7, the stirring member drive motor 44 is turned on.

  The stirring member drive motor 44 is about to turn OFF after a predetermined time α (two-dot chain line) after the container rotation motor 71 is turned OFF (one-dot chain line). When it is ON, it continues to be ON.

  Since the conveying member driving motor 54 is turned off after the predetermined time α, the stirring member driving motor 44 continues to be turned on until then and is turned off.

  According to the developer replenishing device 4 having the configuration and method described with reference to FIGS. 2 to 7, for example, when the image forming apparatus is started up or when the developer container 60 is replaced after continuous mass image output. The surface of the developer inside the hopper portion 41 and the developer transport portion 51 of the developer replenishing device 4 can be made almost flat, the accuracy of detecting the presence or absence of the developer is improved, and as a result, the developer replenishment to the developing device is stabilized. It becomes possible.

  Even when the developer replenishing device 4 (first storage space 42a, second storage space 42b, and developer transport unit 51) is made thin due to the recent demand for colorization and miniaturization, the hopper 41 and Since the surface of the developer inside the developer transport section 51 can be made almost flat, it is possible to stably detect the presence or absence of the developer, and as a result, it is possible to stably supply the developer to the developing device.

  Further, according to the image forming apparatus 1 equipped with the developer replenishing device 4, it is possible to obtain an output image that suppresses a decrease in image density.

  8 and 9 are second flowcharts relating to the control of the developer replenishing device, particularly the control of the stirring member driving motor of the hopper.

In this flow, (1) after the developer container 60 is replaced, the stirring screw is rotated, and when the developer detection sensor continuously detects the presence of the developer for a predetermined time,
It is determined that the developer in the hopper is stable, and thereafter, the stirring member drive motor is operated only during rotation of the transport member drive motor and the container rotation motor,
(2) If the developer detection sensor does not continuously detect the presence of the developer for a predetermined time, it is determined that the developer in the hopper is not yet stable, and the developer in the hopper is stabilized.
The stirring member driving motor is operated during the operation of the conveying member driving motor, during the operation of the container rotation motor, and within a predetermined time after the completion of the operation.

  The flow will be described below.

1. Turn on the power and close the container replacement door to replace the developer storage container Monitor the ON of the control power supply and the closing of the container replacement door (not shown) to replace the developer storage container 60, and turn on the control power Alternatively, when it is detected that the container replacement door (not shown) is closed, the process proceeds to step S101.

  At this time, the conveying member driving motor 54, the container rotating motor 71, and the stirring member driving motor 44 are stopped.

2. Stirring member drive motor ON Step S201
In order to level the surface of the developer supplied from the developer storage container in the first storage space 42a and the second storage space 42b, the developer stirring member drive motor 44 is turned on to stir and circulate the developer. Proceed to the next step.

3. Reading developer detection sensor detection information Step S202
The detection information of the developer detection sensor 45 is read and the process proceeds to the next step.

4). Detection duration determination Step S203
When the detection time read by the developer detection sensor 45 is determined and the detected detection time continues for a predetermined time t2 or longer (Yes), the surface of the developer inside the hopper portion 41 and the developer transport portion 51. Is determined to have become flat, and the process proceeds to step S205.

  If the detection time is continuously less than the predetermined time t2 (No), the surface of the developer is not yet flattened, and there is a possibility that the developer in the developer transport portion 51 has not reached a sufficient amount. In this case, it is determined that there is a possibility that the supply of the developer to the developing device 34 may be hindered, and the process proceeds to the next step.

5). Container rotation motor ON, stirring member drive motor ON Step S204
In order to flatten the developer surface, the container rotation motor 71 is rotated for a predetermined time,
The stirring member drive motor 44 continues to operate for a predetermined time α while the container rotation motor 71 is rotating and after the rotation is stopped, and the process proceeds to the next step.

  As a result, the developer is replenished from the developer storage container 60, and the replenished developer is stirred and circulated in the first storage space 42a and the second storage space 42b, so that the developer surface gradually becomes flat. .

6). Reading developer detection sensor detection information Step S206
The detection information of the developer detection sensor 45 is read and the process proceeds to the next step.

7). Detection duration determination Step S207
When the detection time read by the developer detection sensor 45 is determined and the detected detection time continues for a predetermined time t2 or longer (Yes), the surface of the developer inside the hopper portion 41 and the developer transport portion 51. Is determined to have become flat, and the process proceeds to step S208.

  If the detection time is continuously less than the predetermined time t2 (No), the surface of the developer is not yet flattened, and there is a possibility that the developer in the developer transport portion 51 has not reached a sufficient amount. In this case, it is determined that there is a possibility that the developer replenishment to the developing device 34 may be hindered, and the process proceeds to step S204 to repeat the developer replenishment and the agitation / circulation.

8). Stirring member drive motor OFF Step S205
The stirring member drive motor 44 is stopped, and the process proceeds to Step S220 (B in FIG. 9).

9. Stirring member drive motor, container rotation motor OFF Step S208
The stirring member drive motor 44 and the container rotation motor 71 are stopped, and the process proceeds to Step S220 (B in FIG. 9).

  FIG. 9 describes the continuation of this flow.

In step S101 to step S208, the developer has already been stably conveyed inside the hopper 41 and the developer conveyance unit 51, and the surface is substantially flat.
Thereafter, the developer agitating member driving motor 44 is operated only while the container rotating motor 71 or the conveying member driving motor 54 is operating.

In FIG.
10. Container Rotation Motor State Determination Step S209
The operation state (ON / OFF) of the container rotation motor 71 that rotationally drives the developer container 60 is monitored. If it is in operation (Yes), the process proceeds to step S211. If it is not in operation (No), the next step is performed. Proceed to

11. Conveyance member drive motor state determination Step S210
The operation state (ON / OFF) of the conveyance member drive motor 54 that rotationally drives the conveyance member 52 of the developer conveyance unit 51 is monitored. If it is in operation (Yes), the process proceeds to the next step, and if it is not in operation (No) ) Proceeds to step S212.

12 Stirring member drive motor ON Step S211
In order to stir and circulate the developer in the first storage space 42a and the second storage space 42b, the developer stirring member drive motor 44 is turned on and the process proceeds to step S213.

13. Stirring member drive motor OFF Step S212
The developer stirring member drive motor 44 is turned off to stop the stirring and circulation of the developer, and the process proceeds to the next step.

14 Power OFF or container replacement door close monitoring Step S213
Steps S209 to S212 are repeated until the control power supply is turned off or the container exchange door (not shown) is closed and until the control power supply is turned on or a new closure of the container exchange door (not shown) is detected (No). ,
When the control power supply is turned ON or a new closing of the container replacement door (not shown) is detected (Yes), the process proceeds to the end.

  FIG. 10 is a timing chart for supplementary explanation for the flows shown in FIGS.

  This chart conceptually shows ON / OFF of the stirring member drive motor 44, ON / OFF of the container rotation motor 71, and ON / OFF of the transport member drive motor 54.

  The horizontal axis shows the passage of time.

  The vertical axis indicates ON / OFF of the container rotation motor 71, the conveyance member drive motor 54, and the stirring member drive motor 44.

  1. When the conveying member drive motor 54 is turned on at the timing T1 before the developer container 60 is replaced, the stirring member drive motor 44 is turned on.

  Then, the agitating member driving motor 44 is turned off by turning off the conveying member driving motor 54.

  2. When the container rotation motor 71 is turned on at the timing T2 before the replacement of the developer storage container 60, the stirring member drive motor 44 is turned on.

  When the container rotation motor 71 is turned off, the stirring member drive motor 44 is turned off.

  3. At timing T3, the developer container 60 is replaced, and after the replacement, the developer detection sensor 45 has not detected the presence of the developer for a predetermined time or more.

  4). When the container rotation motor 71 is turned on at timing T4 when the presence of the developer is not detected for a predetermined time or longer, the stirring member drive motor 44 is turned on.

  Then, the stirring member drive motor 44 is turned OFF after a predetermined time α from the OFF (one-dot chain line) of the container rotation motor 71.

  By the operation of the container rotation motor 71 and the operation of the stirring member drive motor 44, the developer is replenished inside the hopper, the developer is stirred, and the developer surface becomes substantially flat.

  5). At a timing T5 after the developer surface becomes substantially flat, when the conveying member drive motor 54 is turned on, the agitating member driving motor 44 is turned on. When the conveying member driving motor 54 is turned off, the agitating member driving motor 44 is turned off. It becomes OFF.

  6). At timing T6 after the developer surface becomes substantially flat, when the container rotation motor 71 is turned on, the stirring member drive motor 44 is turned on. When the container rotation motor 71 is turned off, the stirring member drive motor 44 is turned off. Become.

According to the developer supply device 4 having the configuration and method described with reference to FIGS. 2 to 5 and FIGS. 8 to 10, in addition to the effects by the configuration and method described with reference to FIGS. Compared to the configuration and method, it is possible to reduce the operation time of the agitating member drive motor after the first replacement after the developer container 60 is replaced,
Energy saving can be achieved, and the effects of further improving environmental conservation can be achieved.

FIG. 1 is a cross-sectional view showing an embodiment of an image forming apparatus having a developer supply device of the present invention. FIG. 3 is a cross-sectional view of the developer supply device as viewed from the side. FIG. 3 is a cross-sectional view of the developer supply device as seen from above. It is a figure which shows the state of the developer of the developer supply apparatus by replacement | exchange of a developer storage container. FIG. 4 is a block diagram relating to control of a developer supply device and an image forming apparatus. FIG. 5 is a basic flow chart regarding control of a developer supply device, particularly control of a stirring member drive motor of a hopper. It is a timing chart of the supplementary explanation with respect to the flow shown in FIG. It is a 2nd flowchart regarding control of a developer supply apparatus, especially control of the stirring member drive motor of a hopper part. It is a 2nd flowchart regarding control of a developer supply apparatus, especially control of the stirring member drive motor of a hopper part. FIG. 10 is a timing chart for supplementary explanation for the flows shown in FIGS. 8 and 9. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 4 Developer supply apparatus 40 Housing 41 Hopper part 42a 1st storage space 42b 2nd storage space 43a 1st stirring member 43b 2nd stirring member 44 Stirring member drive motor 45 Developer detection sensor 46 throwing in Port 51 Developer transport section 52 Transport member 53 Discharge port 54 Transport member drive motor 60 Developer storage container 70 Developer discharge means 71 Container rotation motor 100 Control means

Claims (8)

In an image forming apparatus having a developer discharging means for discharging a developer from a developer storage container and a developer supply device for supplying the developer from the developer storage container to the developing device.
The developer replenishing device has a hopper that temporarily stores the developer, and a developer transport unit that transports the developer from the hopper to the developing device,
Control means for operating a stirring member that stirs the developer disposed in the hopper section during the operation of the developer discharging means and for a predetermined time after the completion of the operation and during the operation of the developer transport section. An image forming apparatus comprising: In an image forming apparatus having a developer discharging means for discharging a developer from a developer storage container and a developer supply device for supplying the developer from the developer storage container to the developing device.
The developer replenishing device includes a hopper portion for temporarily storing the developer, a developer transport portion for transporting the developer from the hopper portion to the developing device, and a developer detection sensor for detecting the presence or absence of the developer in the hopper portion. And having
After the developer container is mounted on the developer discharging means, the developer discharging means is in operation and after the operation is completed until the developer detecting sensor detects the presence of the developer continuously for a predetermined time. A predetermined time and during the operation of the developer transport unit, the stirring member attached to the hopper unit and stirring the developer is operated,
After the developer storage container is mounted on the developer discharge means, after the developer detection sensor detects the presence of the developer for a predetermined time, during the operation of the developer discharge means and the development During the operation of the agent transport unit, the control means for operating the stirring member,
An image forming apparatus comprising: The hopper portion has a plurality of storage spaces, and each of the storage spaces is provided with the stirring member,
The image forming apparatus according to claim 1, wherein a transport member that transports the developer toward the developing device is disposed in the developer transport section. The hopper portion has a first storage space and a second storage space for temporarily storing the developer,
The first storage space and the second storage space are developed by the first stirring member disposed in the first storage space and the second stirring member disposed in the second storage space. The agent is circulated while being stirred,
The image forming apparatus according to claim 3, wherein a part of the circulating developer is conveyed toward the developing device while being agitated by the conveying member. The image forming apparatus according to claim 4, wherein the first agitating member, the second agitating member, and the conveying member are formed of a helical screw. The image forming apparatus according to claim 4, wherein an upper end of the spiral screw constituting the conveying member is located below a developer detection position of the developer detection sensor. The developer replenishing device has a charging port on the upper side of the housing, and a discharging port for discharging the developer toward the developing device on the lower side of the housing. The image forming apparatus according to claim 3, wherein the image forming apparatus is an image forming apparatus. The image forming apparatus according to claim 7, wherein the developer detection sensor is disposed on a side surface of the housing in the first storage space.

Images