JP2014235339A - Powder supply device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a powder supply device configured to prevent clogging of a powder conveyance path formed from a storage container to a reservoir container when powder is excessively conveyed by first conveyance means, and an image forming apparatus.SOLUTION: A powder supply device 60 includes: a storage container 32 storing powder; a reservoir container 63 which temporarily reserves the powder supplied from the storage container, and has an outlet for discharging the powder temporarily reserved to a device 7 to be supplied; first conveyance means 181a for conveying the powder from the storage container to the reservoir container through the powder conveyance path; second conveyance means 181b for conveying the powder from the reservoir container to the device 7 to be supplied; and powder amount detection means 111 for detecting whether a predetermined amount of powder is contained in the reservoir container. Control means 100 controls the first conveyance means, when the powder amount detection means detects no powder when the second conveyance means is driven once in powder conveyance operation for conveying a predetermined amount of powder, to drive the first conveyance means once in powder conveyance operation for conveying the powder so as not to exceed the predetermined amount.

Description

  The present invention relates to a powder replenishing device used in an image forming apparatus such as a printer, a facsimile machine, and a copying machine, and an image forming apparatus using the powder replenishing device.

  In an image forming apparatus, a latent image formed on a photoreceptor, which is an image carrier, is visualized by a developing device with a developer containing at least toner that is powder, and the latent image is developed. As a result, toner is consumed, so that it is necessary to supply toner to the developing device. For this reason, it is known that toner is supplied from a toner bottle containing toner to the developing device by a toner replenishing device provided in the image forming apparatus, and the toner is replenished into the developing device (for example, Patent Document 1). .

  Some toner replenishing devices are provided with a toner storage container for temporarily storing toner supplied from a toner bottle having a cylindrical shape and a spiral protrusion formed on an inner peripheral surface thereof. The first toner transport mechanism that transports the toner from the toner bottle to the toner storage container includes a bottle driving motor that rotates the toner bottle and a spiral protrusion formed on the inner peripheral surface of the toner bottle. .

  Then, the toner bottle is rotated by the rotational driving force from the bottle driving motor while the toner bottle is mounted on the toner replenishing device. Thus, the toner stored in the toner bottle is transported from the rear end side to the front end side of the toner bottle by the spiral protrusion, and the first toner transport path from the opening provided on the front end side of the toner bottle. The toner is supplied to the toner storage container through the toner storage container.

  The second toner transport mechanism that transports toner from the toner storage container to the developing device includes a toner transport screw, a transport screw driving motor that rotates the toner transport screw, and the like. Then, the toner conveying screw is rotated by a rotational driving force from the conveying screw driving motor to convey the toner in the toner storage container toward the toner discharge port, and the developing device passes through the second toner conveyance path from the toner discharge port. Toner is replenished.

  By providing the toner storage container in the toner replenishing device in this manner, even if the toner in the toner bottle runs out, the toner in the toner storage container can be replenished to the developing device for printing for a certain period of time.

  Further, a toner amount detection sensor for detecting the toner amount from the presence or absence of toner at a predetermined height in the toner storage container is provided on the inner wall of the toner storage container. Then, based on the “toner present” and “toner absent” signals output from the toner amount detection sensor, the first toner transport mechanism causes the toner to be kept within the toner storage container so that the toner amount does not become smaller than a predetermined amount. Toner is supplied from the bottle to the toner storage container.

  Conventionally, the toner is transported from the toner bottle to the toner storage container by the first toner transport mechanism until the toner amount detection sensor outputs a toner presence signal. However, if the toner amount detection sensor causes false detection during the toner conveyance by the first toner conveyance mechanism and a signal indicating no toner continues to be output, the first toner conveyance mechanism is driven more than necessary, and an excessive amount is generated in the toner storage container. Toner is conveyed. As a result, there is a problem that the toner storage container becomes full and the toner is clogged in the first toner conveyance path.

  The present invention has been made in view of the above problems, and its purpose is to prevent the powder transport path from the storage container to the storage container from being clogged by the powder being transported excessively by the first transport means. It is an object of the present invention to provide a powder supply device that can be suppressed and an image forming apparatus including the powder supply device.

  In order to achieve the above object, the invention of claim 1 is characterized in that a storage container for storing powder and a powder supplied from the storage container are temporarily stored and replenished through the temporarily stored powder. A storage container provided with a discharge port for discharging toward the target, first transport means for transporting powder from the storage container to the storage container through a powder transport path, and powder from the storage container to the replenishment target A powder replenishing apparatus comprising a second transporting means for transporting a powder and a powder amount detecting means for detecting whether or not a predetermined amount of powder is present in the storage container. While the second conveying means is driven once in the powder conveying operation, when the powder amount detecting means detects the absence of powder, the powder conveying the amount of powder not exceeding the predetermined amount There is a control means for controlling the first conveying means to be driven once in the body conveying operation. And it is characterized in Rukoto.

  As described above, according to the present invention, there is an excellent effect that it is possible to suppress clogging of the powder conveyance path from the storage container to the storage container by excessively conveying the powder by the first conveyance unit.

6 is a timing chart showing the relationship between the output timing of the toner amount detection sensor and the drive timing of the second drive motor and the first drive motor. 1 is a schematic configuration diagram illustrating a printer according to an embodiment. Schematic which shows the structure of a process unit. The external appearance perspective view of a process unit. FIG. 3 is an exploded configuration diagram showing the inside of the developing unit. FIG. 3 is a block diagram showing a part of an electric circuit of the printer. FIG. 4 is a schematic diagram illustrating a state where a toner container is installed in the toner supply device. FIG. 3 is a schematic perspective view showing a container mounting portion of the copier in a state where a toner container is set. The perspective view of a container mounting part and a toner supply apparatus. FIG. 4 is a perspective view of a container mounting portion and a toner replenishing device showing a state where a toner container is installed in the container mounting portion. FIG. 6 is a perspective view of the container mounting portion and the toner supply device as viewed from the toner supply device side. FIG. 3 is an external view of a container side drive mechanism unit and a sub hopper side drive mechanism unit of a drive mechanism provided in a toner supply device. The schematic block diagram of a sub hopper side drive mechanism part. FIG. 3 is a perspective view showing a toner container. FIG. 3 is an enlarged perspective view illustrating a toner replenishing device and a front end portion of the toner container before the toner container is mounted. FIG. 3 is an enlarged perspective view showing a toner replenishing device in a state in which a toner container is mounted and a front end side of the toner container. FIG. 3 is a longitudinal sectional view showing a toner replenishing device and a front end portion of the toner container before the toner container is mounted. FIG. 3 is a vertical cross-sectional view showing a toner replenishing device with a toner container mounted thereon and a front end portion of the toner container. FIG. 3 is a cross-sectional view of a toner supply device. FIG. 3 is a cross-sectional view of the toner container and the toner replenishing device showing the internal configuration from the toner container to the toner replenishing device. The schematic perspective view when an inside is seen from the upper left of a sub hopper. The figure which shows the state when a toner amount detection sensor erroneously detects that there is no toner in spite of a sufficient amount of toner in the sub hopper. 6 is a timing chart showing the relationship between the output timing of the toner amount detection sensor and the drive timing of the second drive motor and the first drive motor. FIG. 5A is a diagram illustrating a state where a space is temporarily generated before the toner amount detection sensor and the toner is exhausted; FIG. 5B is a diagram illustrating a state where toner is conveyed by a mylar to a space generated before the toner amount detection sensor; 6 is a timing chart showing the relationship between the output timing of the toner amount detection sensor and the drive timing of the second drive motor and the first drive motor. 6 is a flowchart relating to drive control of a toner amount detection sensor, a second drive motor, and a first drive motor.

  An embodiment in which the present invention is applied to an electrophotographic printer (hereinafter simply referred to as “printer”) as an image forming apparatus will be described below.

  First, a basic configuration of the printer according to the embodiment will be described. FIG. 2 is a schematic configuration diagram illustrating the printer according to the embodiment.

  The printer includes four process units 1Y, 1C, 1M, and 1K for yellow, cyan, magenta, and black (hereinafter referred to as Y, C, M, and K). These use Y, C, M, and K toners of different colors as image forming substances for forming an image, but the other configurations are the same.

  FIG. 3 is a schematic diagram showing a configuration of a process unit 1Y for generating a Y toner image. FIG. 4 is a perspective view showing the appearance of the process unit 1Y.

  In these drawings, the process unit 1Y has a photoreceptor unit 2Y and a developing device 7Y. As shown in FIG. 4, the photoreceptor unit 2Y and the developing device 7Y are configured to be detachable as a process unit 1Y integrally with the printer main body.

  However, the developing device 7Y can be attached to and detached from the photoreceptor unit 2Y in a state where it is detached from the printer main body.

  The photoreceptor unit 2Y includes a drum-shaped photoreceptor 3Y as a latent image carrier, a drum cleaning device 4Y, a static eliminator (not shown), a charging device 5Y, and the like.

  The charging device 5Y as a charging unit uniformly charges the surface of the photosensitive member 3Y, which is driven to rotate clockwise in FIG. 2 by a driving unit (not shown), by the charging roller 6Y. Specifically, in FIG. 3, a charging bias is applied from a power source (not shown) to the charging roller 6Y that is driven to rotate counterclockwise, and the charging roller 6Y is brought close to or in contact with the photosensitive member 3Y. 3Y is uniformly charged.

  Instead of the charging roller 6Y, another charging member such as a charging brush may be used in proximity or contact. Further, a charger that uniformly charges the photosensitive member 3Y by a charger method, such as a scorotron charger, may be used. The surface of the photoreceptor 3Y uniformly charged by the charging device 5Y is exposed and scanned by a laser beam emitted from an optical writing unit 20 serving as a latent image forming unit, which will be described later, and carries an electrostatic latent image for Y.

  FIG. 5 is an exploded configuration diagram showing the inside of the developing device 7Y. As shown in FIGS. 3 and 5, the developing device 7 </ b> Y as a developing unit has a first agent storage chamber 9 </ b> Y in which a first developer conveying screw 8 </ b> Y as a developer conveying unit is disposed.

  Further, it also has a second agent storage chamber 14Y in which a toner concentration sensor 10Y comprising a magnetic permeability sensor as a toner concentration detecting means, a second developer conveying screw 11Y, a developing roll 12Y, a doctor blade 13Y and the like are disposed. .

  In these two agent storage chambers forming the circulation path, a Y developer (not shown) which is a two-component developer composed of a magnetic carrier and a negatively chargeable Y toner is contained.

  The first developer transport screw 8Y is driven to rotate by a driving means (not shown), thereby transporting the Y developer in the first agent storage chamber 9Y toward the front side in FIG. 3 (in the direction of arrow A in FIG. 5). . The Y developer in the middle of conveyance is a portion (hereinafter referred to as “replenishment position”) facing the toner replenishing port 17Y in the first agent storage chamber 9Y by the toner concentration sensor 10Y fixed above the first developer conveyance screw 8Y. ), The toner concentration of the Y developer passing through a predetermined detection position located downstream of the developer circulation direction is detected. Then, the Y developer transported to the end of the first agent storage chamber 9Y by the first developer transport screw 8Y enters the second agent storage chamber 14Y through the communication port 18Y.

  The second developer transport screw 11Y in the second agent storage chamber 14Y is rotationally driven by a driving means (not shown) to transport the Y developer to the back side in FIG. 3 (in the direction of arrow A in FIG. 5). In this way, the developing roller 12Y is arranged in a posture parallel to the second developer conveying screw 11Y above the second developer conveying screw 11Y that conveys the Y developer in FIG.

  The developing roll 12Y includes a magnet roller 16Y fixedly disposed in a developing sleeve 15Y made of a non-magnetic sleeve that is driven to rotate counterclockwise in FIG.

  A part of the Y developer conveyed by the second developer conveying screw 11Y is pumped up to the surface of the developing sleeve 15Y by the magnetic force generated by the magnet roller 16Y. Then, after the layer thickness is regulated by a doctor blade 13Y disposed so as to maintain a predetermined gap from the surface of the developing sleeve 15Y, the layer is conveyed to a developing region facing the photosensitive member 3Y, and is transferred onto the photosensitive member 3Y. Y toner is adhered to the electrostatic latent image for Y. This adhesion forms a Y toner image on the photoreceptor 3Y. The Y developer that has consumed Y toner by the development is returned to the second developer conveying screw 11Y as the developing sleeve 15Y rotates.

  Then, the Y developer transported to the end of the second agent storage chamber 14Y by the second developer transport screw 11Y returns to the first agent storage chamber 9Y through the communication port 19Y. In this way, the Y developer is circulated and conveyed in the developing unit.

  FIG. 6 is a block diagram showing a part of the electric circuit of the printer. The detection result of the toner concentration of the Y developer by the toner concentration sensor 10Y is sent to the control unit 100 as an electric signal.

  The control unit 100 includes a CPU (Central Processing Unit) 101 as a calculation means, a RAM (Random Access Memory) 102 as a storage unit, a ROM (Read Only Memory) 103, and the like. Various arithmetic processes and control programs can be executed.

  The control unit 100 stores data of the Y target voltage Vtref, which is the target value of the output voltage from the toner density sensor 10Y, in the RAM 102. Further, data of target voltages Vtref for C, M, and K, which are target values of output voltages from the toner density sensors 10C, 10M, and 10K mounted in the other developing devices 7C, 7M, and 7K, are also stored. Yes.

  For the developing device 7Y for Y, the value of the output voltage from the toner density sensor 10Y is compared with the target voltage Vtref for Y, and an amount of Y toner corresponding to the comparison result is supplied from the toner supply port 17Y. The drive mechanism 180 of the Y toner supply device 60 is controlled.

  Specifically, the drive mechanism 180 is divided into a container-side drive mechanism 181a (see FIG. 12) and a sub-hopper side drive mechanism 181b (see FIG. 12), which will be described later. And the drive with the 1st drive motor 182a (refer FIG. 12) provided in the container side drive mechanism part 181a and the 2nd drive motor 182b (refer FIG. 12) provided in the sub hopper side drive mechanism part 181b is controlled. The unit 100 controls. Further, the container side drive mechanism 181a and the sub hopper side drive mechanism 181b are independently driven.

  With this control, an appropriate amount of Y toner is supplied in the first agent storage chamber 9Y to the Y developer whose Y toner density has decreased due to consumption of Y toner during development. For this reason, the toner concentration of the Y developer in the second agent storage chamber 14Y is maintained within the target toner concentration range. The same applies to the developers in the developing devices 7C, 7M, and 7K for other colors.

  The controller 100 is also connected with a toner amount detection sensor 111 that detects the amount of toner in the sub hopper 63 provided in the toner supply device 60. In this embodiment, a piezoelectric sensor is used as the toner amount detection sensor 111, but another sensor such as a light reflection sensor may be used.

  In FIG. 2 described above, the Y toner image formed on the photoreceptor 3Y is intermediately transferred to the intermediate transfer belt 41 which is an intermediate transfer body. The drum cleaning device 4Y of the photoreceptor unit 2Y removes toner remaining on the surface of the photoreceptor 3Y after the intermediate transfer process. As a result, the surface of the photoreceptor 3Y subjected to the cleaning process is neutralized by a neutralizing device (not shown). By this charge removal, the surface of the photoreceptor 3Y is initialized and prepared for the next image formation.

  Similarly, in the process units 1C, 1M, and 1K for other colors, C toner images, M toner images, and K toner images are formed on the photoreceptors 3C, 3M, and 3K, and the intermediate transfer belt 41 is subjected to intermediate transfer. Is done.

  An optical writing unit 20 is disposed below the process units 1Y, 1C, 1M, and 1K in FIG. The optical writing unit 20 emits a laser beam L based on image information (pixel information) acquired by the control unit 100 from an externally connected computer or the like to each of the process units 1Y, 1C, 1M, and 1K. , 3C, 3M, 3K. As a result, electrostatic latent images for Y, C, M, and K are formed on the photoreceptors 3Y, 3C, 3M, and 3K, respectively.

  The optical writing unit 20 deflects the laser light L emitted from the light source by the polygon mirror 21 that is rotationally driven by a motor, and passes through the photoreceptors 3Y, 3C, 3M, and 3K via a plurality of optical lenses and mirrors. Is irradiated. Instead of such a configuration, an LED array may be used.

  A first paper feed cassette 22 and a second paper feed cassette 23 are disposed below the optical writing unit 20 so as to overlap in the vertical direction. In each of these paper feed cassettes, a plurality of recording papers P, which are recording materials, are stored in a bundle of recording papers, and the top recording paper P includes a first paper feed roller. 22a and the second paper feed roller 23a are in contact with each other.

  When the first paper feed roller 22a is rotated counterclockwise in FIG. 2 by driving means (not shown), the uppermost recording paper P in the first paper feed cassette 22 is vertically oriented on the right side of the cassette in FIG. The paper is discharged toward the paper feed path 24 arranged so as to extend.

  When the second paper feed roller 23a is driven to rotate counterclockwise in FIG. 2 by driving means (not shown), the uppermost recording paper P in the second paper feed cassette 23 is discharged toward the paper feed path 24. The

  A plurality of transport roller pairs 25 are arranged in the paper feed path 24, and the recording paper P fed into the paper feed path 24 is sandwiched between the rollers of the transport roller pair 25 while being fed. 2 is conveyed from the lower side to the upper side in FIG.

  A registration roller pair 26 is disposed at the end of the paper feed path 24. The registration roller pair 26 temporarily stops the rotation of both rollers as soon as the recording paper P sent from the conveyance roller pair 25 is sandwiched between the rollers. Then, the recording paper P is sent out toward a secondary transfer nip described later at an appropriate timing.

  Above each of the process units 1Y, 1C, 1M, and 1K in FIG. 2, a transfer unit 40 that endlessly moves counterclockwise in FIG. 2 while stretching the intermediate transfer belt 41 is disposed.

  In addition to the intermediate transfer belt 41, the transfer unit 40 includes a belt cleaning unit (not shown), four primary transfer rollers 45Y, 45C, 45M, and 45K, a secondary transfer backup roller 46, a drive roller 47, a tension roller 49, and the like. Yes.

  The intermediate transfer belt 41 is endlessly moved counterclockwise in FIG. 2 by the rotation of the driving roller 47 while being stretched around these rollers. The four primary transfer rollers 45Y, 45C, 45M, and 45K sandwich the intermediate transfer belt 41 that moves endlessly between the photoreceptors 3Y, 3C, 3M, and 3K to form primary transfer nips. A transfer bias having a polarity opposite to that of the toner (in this embodiment, a positive polarity) is applied to the inner peripheral surface of the intermediate transfer belt 41.

  As the endless movement of the intermediate transfer belt 41 passes through the primary transfer nips for Y, C, M, and K in sequence, the intermediate transfer belt 41 is placed on the outer surface of the photoreceptor 3Y, 3C, 3M, 3K. The color toner images are primarily transferred so as to overlap each other. As a result, a four-color superimposed toner image (hereinafter referred to as “four-color toner image”) is formed on the intermediate transfer belt 41.

  The secondary transfer backup roller 46 sandwiches the intermediate transfer belt 41 with the secondary transfer roller 50 disposed outside the loop of the intermediate transfer belt 41 to form a secondary transfer nip.

  The registration roller pair 26 described above feeds the recording paper P sandwiched between the rollers toward the secondary transfer nip at a timing at which the recording paper P can be synchronized with the four-color toner image on the intermediate transfer belt 41.

  The four-color toner image on the intermediate transfer belt 41 is affected by the secondary transfer electric field formed between the secondary transfer roller 50 to which the secondary transfer bias is applied and the secondary transfer backup roller 46, and the influence of the nip pressure. Then, the secondary transfer is batch-transferred onto the recording paper P in the secondary transfer nip. Then, combined with the white color of the recording paper P, a full color toner image is obtained.

  Transfer residual toner that has not been transferred to the recording paper P adheres to the intermediate transfer belt 41 after passing through the secondary transfer nip. This is cleaned by a belt cleaning unit.

  In the belt cleaning unit, a cleaning member such as a cleaning blade is brought into contact with the front surface of the intermediate transfer belt 41, whereby the transfer residual toner on the belt is scraped off and removed.

  A fixing device 80 as a fixing unit is disposed above the secondary transfer nip in the drawing. The fixing device 80 includes a pressure heating roller 81 that includes a heat source such as a halogen lamp, and a fixing belt unit 82.

  The fixing belt unit 82 includes a fixing roller 84, a heating roller 83 containing a heat source such as a halogen lamp, a tension roller 85, a driving roller 86, a temperature sensor (not shown), and the like.

  Then, the endless fixing belt 84 is endlessly moved in the counterclockwise direction in FIG. 2 while being stretched by the heating roller 83, the tension roller 85, and the driving roller 86. In the process of endless movement, the fixing belt 84 is heated from the back side by the heating roller 83. A pressure heating roller 81 that is driven to rotate in the clockwise direction in FIG. 2 is in contact with the surface of the fixing belt 84 that is heated in this manner. Thus, a fixing nip where the pressure heating roller 81 and the fixing belt 84 abut is formed.

  A temperature sensor (not shown) is disposed outside the loop of the fixing belt 84 so as to face the front surface of the fixing belt 84 with a predetermined gap, and the fixing belt 84 just before entering the fixing nip. Detect surface temperature. This detection result is sent to a fixing power supply circuit (not shown).

  The fixing power supply circuit performs on / off control of power supply to the heat generation source included in the heating roller 83 and the heat generation source included in the pressure heating roller 81 based on the detection result of the temperature sensor. As a result, the surface temperature of the fixing belt 84 is maintained at about 140 [° C.].

  The recording paper P that has passed through the secondary transfer nip is separated from the intermediate transfer belt 41 and then fed into the fixing device 80. Then, in the process of being conveyed from the lower side to the upper side in the figure while being sandwiched between the fixing nips in the fixing device 80, the full-color toner image is applied to the recording paper P by being heated or pressed by the fixing belt 84. To settle.

  The recording sheet P subjected to the fixing process in this manner is discharged outside the apparatus after passing between the rollers of the discharge roller pair 87. A stack unit 88 is formed on the top surface of the printer body, and the recording paper P discharged to the outside by the discharge roller pair 87 is sequentially stacked on the stack unit 88.

  Above the transfer unit 40, toner containers 32Y, 32C, 32M, and 32K, which are four toner storage containers for storing Y toner, C toner, M toner, and K toner, are disposed in the toner bottle storage section. Yes.

  The color toners in the toner containers 32Y, 32C, 32M, and 32K are appropriately supplied by the toner replenishing device 60 to the developing devices 7Y, 7C, 7M, and 7K of the process units 1Y, 1C, 1M, and 1K, respectively. The toner containers 32Y, 32C, 32M, and 32K are detachable from the printer main body independently of the process units 1Y, 1C, 1M, and 1K.

  As previously shown in FIG. 5, the toner concentration sensor 10Y has a toner concentration in the developer immediately before entering the second agent storage chamber 14Y as the supply region in the first agent storage chamber 9Y as the non-supply region. Is detected.

  The toner supply port 17Y is provided at a position for supplying toner to the developer immediately after entering the first agent storage chamber 9Y from the second agent storage chamber 14Y. That is, in the first agent storage chamber 9Y, the toner concentration sensor 10Y detects the toner concentration of the developer at a position downstream of the toner supply port 17Y.

Next, the toner replenishing devices 60Y, M, C, and K will be described.
FIG. 7 is a schematic view showing a state in which the toner container 32Y is installed in the toner replenishing device 60Y, and FIG. 8 is a container-mounted state in which four toner containers 32Y, M, C, and K are set. FIG. 6 is a schematic perspective view showing a part 70.

  FIG. 9 is a perspective view of the container mounting portion 70 and the toner supply device 60. FIG. 10 is a perspective view of the container mounting portion 70 and the toner replenishing device 60, showing a state where the toner container 32 is installed in the container mounting portion 70. FIG. 11 is a perspective view of the container mounting portion 70 and the toner supply device 60 as viewed from the toner supply device side. 12 is an external view of the container side drive mechanism 181a and the sub hopper side drive mechanism 181b of the drive mechanism 180 provided in the toner replenishing device 60. FIG. FIG. 13 is a schematic configuration diagram of the sub hopper side drive mechanism 181b.

  The toner in the toner containers 32Y, M, C, and K installed in the container mounting unit 70 is provided for each toner color according to the toner consumption in the developing devices 7Y, M, C, and K of the respective colors. The developing devices 7Y, M, C, and K are appropriately replenished by the toner replenishing devices 60Y, M, C, and K, respectively.

  The four toner replenishing devices 60Y, M, C, and K and the toner containers 32Y, 32M, 32C, and 32K have substantially the same structure except that the colors of toner used in the image forming process are different. Therefore, only the toner replenishing device 60Y and the toner container 32Y corresponding to yellow will be described below, and the toner replenishing devices 60M, C, and K and the toner containers 32M, C, and K corresponding to the other three colors will be described. The description will be omitted as appropriate.

  The toner replenishing devices 60Y, M, C, and K include a container mounting portion 70, transport nozzles 611Y, M, C, and K, transport screws 614Y, M, C, and K, toner drop transport paths 64Y, M, C, and K, The drive mechanism 180Y, M, C, K, etc. are used.

  When the toner container 32Y is inserted in the direction of the arrow Q in the drawing and attached to the container mounting portion 70, the transport nozzle 611Y of the toner replenishing device 60Y is inserted from the front end side of the toner container 32Y in conjunction with the mounting operation. The inside of the toner container 32Y and the inside of the transport nozzle 611Y communicate with each other.

  The toner container 32Y has a cylindrical shape, such as a container tip cover 34Y fixed to the container mounting portion 70 in a non-rotating state, a toner bottle 33Y integrally formed with a container rotation gear 301Y, and the like. It is composed of The container front end cover 34Y as a holding unit rotatably holds the toner bottle 33Y while receiving the front end of the toner bottle 33Y in the rotation axis direction.

  The container mounting part 70 is comprised from the front-end | tip receiving part 73, the container receiving part 72, the insertion port formation part 71 grade | etc.,. The tip receiving portion 73 is for fixing the container tip cover 34Y of the toner container 32Y. The container receiver 72 is for receiving the toner bottle 33Y of the toner container 32Y. The insertion port forming part 71 forms an insertion port during the mounting operation of the toner container 32Y.

  When the main body cover (not shown) installed on the front side of the printer (the front side in the direction perpendicular to the paper surface in FIG. 2) is opened, the insertion port forming portion 71 of the container mounting portion 70 is exposed. Then, in the state where the longitudinal direction of each toner container 32Y, M, C, K is horizontal, the attaching / detaching operation of each toner container 32Y, M, C, K from the front side of the printer (the longitudinal direction of the toner container 32). An attachment / detachment operation with the direction as the attachment / detachment direction is performed. The set cover 608Y in FIG. 7 is a part of the tip receiving portion 73 of the container mounting portion 70.

  The container receiving portion 72 is formed so that its length in the longitudinal direction is substantially equal to the length of the toner bottle 33Y in the longitudinal direction. Further, the tip receiving portion 73 is provided on one end side in the longitudinal direction (attachment / detachment direction) of the container receiving portion 72, and the insertion port forming portion 71 is provided on the other end side in the longitudinal direction of the container receiving portion 72. The container tip cover 34Y slides on the container receiving portion 72 for a while after passing through the insertion port forming portion 71 in accordance with the mounting operation of the toner container 32Y, and is then attached to the tip receiving portion 73.

  With the container front end cover 34Y mounted on the front end receiving portion 73, the drive mechanism 180 constituted by a drive motor, a drive gear, and the like transmits a rotational driving force to the container rotation gear 301Y, so that the toner bottle 33Y is shown in FIG. 7 is driven to rotate in the direction of arrow A.

  By rotating the toner bottle 33Y itself, the toner contained in the toner bottle 33Y is transferred from the rear end side to the front end side (from the rear end side of the bottle) by the spiral protrusion 302Y formed spirally on the inner peripheral surface of the toner bottle 33Y. It is conveyed from the left side to the right side in FIG. And it is supplied in the conveyance nozzle 611Y from the container front end cover 34Y side.

  A transport screw 614Y is disposed in the transport nozzle 611Y, and the transport screw 614Y rotates and transports the toner in the transport nozzle 611Y when rotation driving is input from the drive mechanism 180Y to the transport screw gear 605Y. .

  The downstream end in the transport direction of the transport nozzle 611Y is connected to the toner drop transport path 64Y, and the toner transported by the transport screw 614Y falls in its own weight on the toner drop transport path 64Y and is transported into the sub hopper 63Y.

  Each of the toner containers 32Y, 32M, 32C, and 32K is replaced with a new one when it reaches the end of its life (when the toner to be stored is almost completely consumed and becomes empty). A handle 303 is provided at the end of the toner container 32 opposite to the container tip cover 34 in the longitudinal direction. When replacing, the operator holds the handle 303 and pulls it out. The toner container 32 can be removed.

  Next, the toner containers 32Y, M, C, and K and the toner replenishing devices 60Y, M, C, and K will be described in more detail. As described above, the toner containers 32Y, 32M, 32C, and 32K and the toner replenishing devices 60Y, 60M, 60C, and 60K have substantially the same configuration except that the colors of the toners used are different. In the following description, the suffixes Y, M, C, and K that indicate the color of the toner to be used are omitted.

  FIG. 14 is a perspective view showing the toner container 32 according to the embodiment. FIG. 15 is an enlarged perspective view showing the toner replenishing device 60 before the toner container 32 is mounted and the front end side end of the toner container 32. FIG. 16 is an enlarged perspective view showing the toner replenishing device 60 with the toner container 32 attached and the front end side of the toner container 32.

  FIG. 17 is a longitudinal sectional view showing the toner replenishing device 60 before the toner container 32 is mounted and the tip of the toner container 32. FIG. 18 is a longitudinal sectional view showing the toner replenishing device 60 with the toner container 32 attached and the tip of the toner container 32.

  FIG. 19 is a cross-sectional view of the toner supply device 60. FIG. 20 is a cross-sectional view of the toner container 32 and the toner supply device 60 showing the internal configuration from the toner container 32 to the toner supply device 60.

  As shown in FIG. 17, the toner replenishing device 60 includes a transport nozzle 611 having a transport screw 614 therein. A nozzle shutter member 612 is also provided.

  The nozzle shutter member 612 closes the nozzle opening 610 formed in the transport nozzle 611 when the toner container 32 is not mounted before being mounted (the state shown in FIGS. 15 and 18). Further, when the toner container 32 is mounted (the state shown in FIGS. 17 and 16), the nozzle opening 610 is opened.

  In the center of the front end surface of the toner container 32, a nozzle receiving port 331 into which the transport nozzle 611 is inserted when mounted and a container shutter member 332 that closes the nozzle receiving port 331 when not mounted are provided.

  As shown in FIG. 15, the container front end cover 34 of the toner container 32 has a lock for allowing a container lock member 609 provided on the set cover 608 of the toner replenishing device 60 to penetrate from the outside of the container toward the inside. An opening 339 is provided. The container tip cover 34 is also provided with an ID chip 700 that records data such as the usage status of the toner container 32. Furthermore, a color non-compatible rib 34b is provided to prevent the toner container 32 having a different toner color from being attached to the set cover 608 of another color.

  As shown in FIGS. 15 and 16, the toner replenishing device 60 includes a nozzle holder 607 that fixes the transport nozzle 611 to the frame 602 of the printer body, and the set cover 608 is fixed to the nozzle holder 607. ing.

  Further, a toner dropping conveyance path 64 is fixed to the nozzle holder 607 so as to communicate with the inside of the conveyance nozzle 611 from below the conveyance nozzle 611.

  As shown in FIGS. 19 and 20, the toner drop conveyance path 64 extends in the vertical direction, which is the height direction of the apparatus. In the toner drop transport path 64, the toner transported by the transport screw 614 is dropped, so that the toner drop transport path 64 is always hollow. Then, the toner conveyed from the toner container 32 through the toner dropping conveyance path 64 into the sub hopper 63 is conveyed to the toner amount detection sensor 111 in the sub hopper 63.

  A coil-like swing member 65 is provided in the toner dropping conveyance path 64. Then, by swinging the swing member 65 in the toner drop transport path 64, the toner stays in the toner drop transport path 64 by dropping the toner adhering to the inner wall surface of the toner drop transport path 64. Is suppressed.

  A drive mechanism 180 is fixed to the frame 602. The drive mechanism 180 includes a drive motor 603 and a container drive output gear 601, a worm gear 603 a that transmits the rotational drive of the drive motor 603 to the rotation shaft of the container drive output gear 601, and the like.

  A drive transmission gear 604 is fixed to the rotating shaft of the container drive output gear 601, and is configured to mesh with the conveying screw gear 605 fixed to the rotating shaft of the conveying screw 614. With such a configuration, the toner container 32 is rotated via the container drive output gear 601 and the container rotation gear 301 by rotating the drive motor 603. Then, the transport screw 614 is rotated via the drive transmission gear 604 and the transport screw gear 605.

  A clutch may be provided in a drive transmission path from the drive motor 603 to the container rotation gear 301 or a drive transmission path from the drive motor 603 to the transport screw gear 605. By providing such a clutch, it is possible to realize a configuration in which only one of the toner container 32 and the conveying screw 614 is rotated when the drive motor 603 is driven to rotate.

Next, a process of attaching the toner container 32 to the toner supply device 60 will be described.
As shown by an arrow Q in FIGS. 15 and 17, when the toner container 32 moves in the direction of the toner replenishing device 60, the nozzle tip 611 a of the transport nozzle 611 is brought into contact with the end surface on the tip side of the container shutter member 332. Contact.

  When the toner container 32 further moves in the direction of the toner replenishing device 60, the transport nozzle 611 presses the end surface on the front end side of the container shutter member 332. Thus, when the container shutter spring 336 contracts, the container shutter member 332 is pushed into the inner side (rear end side) of the toner container 32 and the nozzle front end side of the transport nozzle 611 is inserted into the nozzle receiving port 331.

  At this time, the nozzle shutter cylindrical portion 612 b on the nozzle tip side of the nozzle shutter flange 612 a in the nozzle shutter member 612 is also inserted into the nozzle receiving port 331 together with the transport nozzle 611.

  When the toner container 32 further moves in the direction of the toner replenishing device 60, the surface opposite to the nozzle shutter spring receiving surface of the nozzle shutter collar 612 a comes into contact with the end surface on the front end side of the container seal member 333 and the container seal. The member 333 is crushed a little. As a result, the surface opposite to the nozzle shutter spring receiving surface of the nozzle shutter collar 612a abuts against a nozzle shutter abutment rib (not shown), so that the nozzle shutter member 612 is relative to the toner container 32 in the rotation axis direction. The position is fixed.

  When the toner container 32 further moves in the direction of the toner supply device 60, the transport nozzle 611 is further inserted into the toner container 32. At this time, the nozzle shutter member 612 that has abutted against the nozzle shutter abutment rib is pushed back toward the nozzle base with respect to the transport nozzle 611. As a result, the nozzle shutter spring 613 contracts, and the relative position of the nozzle shutter member 612 with respect to the transport nozzle 611 moves to the nozzle base side.

  Along with the movement of the relative position, the nozzle opening 610 covered with the nozzle shutter member 612 is exposed inside the toner bottle 33, and the inside of the toner bottle 33 and the inside of the transport nozzle 611 communicate with each other.

  In a state where the transport nozzle 611 is inserted into the nozzle receiving port 331, the following force acts by the biasing force of the container shutter spring 336 and the nozzle shutter spring 613 in a contracted state.

  That is, the force is in the direction in which the toner container 32 is pushed back against the toner replenishing device 60 (the direction opposite to the arrow Q in the figure). However, when the toner container 32 is attached to the toner replenishing device 60, the toner container 32 resists the above-described force until the container opening member 609 of the set cover 608 is received by the lock opening 339. Then, it is moved in the direction of the toner supply device 60.

  Thus, the toner container 32 is positioned in the rotation axis direction with respect to the toner replenishing device 60 by the urging force of the container shutter spring 336 and the nozzle shutter spring 613 and the hook of the container lock member 609 with respect to the lock opening 339.

  When the toner container is positioned in the rotation axis direction, the outer peripheral surface of the tip opening forming portion 305 is slidably fitted on the inner peripheral surface of the container setting portion 615. For this reason, the toner container 32 is positioned with respect to the toner replenishing device 60 in the plane direction orthogonal to the rotation axis. Thereby, the mounting of the toner container 32 to the toner supply device 60 is completed.

  In a state where the toner container 32 is completely installed, the drive motor 603 is rotated to rotate the toner bottle 33 of the toner container 32 and the transport screw 614 in the transport nozzle 611.

  As the toner bottle 33 rotates, the toner in the toner bottle 33 is conveyed to the front end side of the toner bottle 33 by the spiral protrusion 302. The toner that has reached the pumping unit 304 by this conveyance is lifted above the nozzle opening 610 by the pumping unit 304 as the toner bottle 33 rotates.

  The toner that has been lifted above the nozzle opening 610 falls into the nozzle opening 610, whereby the toner is supplied into the transport nozzle 611. The toner supplied into the transport nozzle 611 is transported by the transport screw 614 and transported to the sub hopper 63 through the toner dropping transport path 64. In FIG. 18, the toner flow from the toner bottle 33 to the toner dropping conveyance path 64 at this time is indicated by an arrow β in FIG. 18.

  In FIG. 18, α represents a position where the tip opening forming portion 305 is slidably in contact with the container setting portion 615 and the toner container 32 is positioned with respect to the toner supply device 60. This position is not limited to a configuration having both functions of the sliding portion and the positioning portion, and may have a configuration having either function of the sliding portion or the positioning portion.

  The nozzle receiving member 330 of the toner container 32 has a nozzle receiving port 331, a shutter support opening 335 b, and a container shutter member 332. A nozzle receiving port 331 provided at the position of the opening of the toner bottle 33 receives a transport nozzle 611 having a nozzle opening 610 that is a powder receiving port.

  The shutter support opening 335 b functions as a replenishing port for supplying toner, which is powder in the toner bottle 33, to the nozzle opening 610 at least partially. Further, the container shutter member 332 is supported by the nozzle receiving member 330, and is opened and closed to slide the moving nozzle 611 in the direction of the rotation axis and open / close the nozzle receiving port 331 by an operation of inserting or extracting the conveying nozzle 611 from the nozzle receiving member 330. Functions as a member. With such a configuration, the toner container 32 maintains the state in which the nozzle receiving port 331 is closed until the transport nozzle 611 is inserted, and the toner leakage in the state before being attached to the toner supply device 60. And can prevent scattering.

  When the transport nozzle 611 is inserted into the nozzle receiving port 331 and the container shutter member 332 pushed by the transport nozzle 611 slides toward the back of the container, the toner accumulated in the vicinity of the shutter support opening 335b is pushed away. For this reason, it is possible to secure a space for the conveyance nozzle 611 in the portion where the nozzle receiving port 331 is formed to enter the periphery of the shutter support opening 335b, and to reliably supply toner from the shutter support opening 335b to the nozzle receiving port 331. Yes.

  As described above, the toner container 32 is reliably attached to the toner replenishing device 60 when it is attached to the toner replenishing device 60 while preventing leakage and scattering of the toner stored in the toner bottle 33 in a state before the toner replenishing device 60 is attached. The toner can be discharged out of the toner bottle 33.

  When the toner container 32 is attached to the toner supply device 60, the container seal member 333 is crushed by the nozzle shutter collar 612a. As a result, the nozzle shutter collar 612a is brought into close contact with the container seal member 333 and toner leakage can be prevented.

Next, the sub hopper 63 will be described.
FIG. 21 is a schematic perspective view of the sub hopper 63 as viewed from the upper left. As shown in FIG. 21, a toner amount detection sensor 111 that detects the presence or absence of toner at the height of the sensor detection surface 111 a provided in the sub hopper 63 is provided on the side surface of the sub hopper 63.

  Also, mylars 112 a and 112 b are provided as two stirring members that are rotatably provided in the sub hopper 63 and stir the toner in the sub hopper 63.

  The mylars 112a and 112b are provided on the rotation shafts 113a and 113b of the gears 146a and 146b that are rotated by the rotational driving force transmitted from the second drive motor 182b via the drive transmission gear 145 and the like. The mylars 112a and 112b rotate with the rotation of the rotating shafts 113a and 113b, and the toner in the sub hopper 63 is agitated.

  The mylar 112a also functions as a sensor detection surface cleaning member that rubs and cleans the sensor detection surface 111a. As a result, the toner attached to the sensor detection surface 111a is scraped off by the mylar 112a, and the erroneous detection caused by the adhesion of the toner to the sensor detection surface 111a, that is, the erroneous detection in which the toner end cannot be detected although there is no toner is suppressed. be able to.

  The sub hopper 63 passes from the sub hopper 63 to the developing device 7 through a toner transport path 61 that connects the sub hopper 63 and the developing device 7 and is provided with a bendable conveying screw 62 (see FIG. 19). Toner is conveyed.

  The transport screw 62 is provided on the rotating shaft 114 of the gear 147, and the rotational driving force from the second drive motor 182 b is transmitted to the gear 147 through the gear 146 b, and the transport screw 62 is rotated with the rotation of the rotating shaft 114. Also rotate.

Next, the operation timing of the toner replenishing device 60 will be described.
When the toner in the developing device 7 is consumed by the printing operation, the toner replenishing device 60 is driven to supplement the toner, and the developing device 7 is replenished with toner from the sub hopper 63. When the toner is supplied to the developing device 7 and the toner in the sub hopper 63 is consumed in this way, the control unit 100 determines the presence or absence of toner in the sub hopper 63 based on the detection result of the toner amount detection sensor 111. .

  When the control unit 100 determines that “no toner”, the first drive motor 182a is driven to convey the toner from the toner container 32 to the sub hopper 63. On the other hand, when the control unit 100 determines that “toner is present”, the first drive motor 182a is not driven, and toner is not transported from the toner container 32 to the sub hopper 63.

  Here, conventionally, when the toner amount detection sensor 111 detects that there is no toner, the first drive motor 182a is driven until the toner amount detection sensor 111 detects that there is toner, and toner is supplied from the toner container 32 to the sub hopper 63. I was carrying it. Therefore, there is an advantage that the toner can be transported quickly.

  However, when the toner amount detection sensor 111 erroneously detects or when the detection reaction is slow, the toner is excessively conveyed. Therefore, the amount of toner in the toner replenishing device 60 is not stable, and in the worst case, there is a problem that the toner is clogged in the toner dropping conveyance path 64.

  FIG. 22 is a diagram illustrating a state where the toner amount detection sensor 111 erroneously detects that there is no toner even though there is a sufficient amount of toner in the sub hopper 63. FIG. 23 is a timing chart showing the relationship between the output timing of the toner amount detection sensor 111 and the drive timing of the second drive motor 182b and the first drive motor 182a when the toner amount detection sensor 111 erroneously detects that there is no toner. It is a chart.

  Although the second drive motor 182b is not driven and there is a sufficient amount of toner in the sub hopper 63 as shown in FIG. 22, the toner amount detection sensor 111 detects that there is no toner, and as shown in FIG. If the one drive motor 182a is driven, the above-described problem occurs. That is, although the toner is not replenished from the sub hopper 63 to the developing device 7, the toner is conveyed from the toner container 32 to the sub hopper 63, and the toner in the sub hopper 63 becomes excessive. Therefore, the sub hopper 63 becomes full or more, and the toner is clogged in the toner dropping conveyance path 64.

  Therefore, in the present embodiment, in consideration of the above-described problems, the first drive motor 182a is driven only once for a predetermined time at the timing when the first drive motor 182a is driven, and the toner container 32 moves to the sub hopper 63. The control unit 100 performs control for conveying the toner.

  Specifically, the second drive motor 182b is driven once in the toner transport operation in which a predetermined amount of toner is transported by the transport screw 62. On the other hand, when the toner amount detection sensor 111 detects the absence of toner, the first drive motor 182a is moved once by the toner transport operation in which the transport screw 614 transports an amount of toner that does not exceed the predetermined amount. Drive.

  Here, if the presence / absence of toner is determined only by the detection result of the toner amount detection sensor 111 at the moment when the second drive motor 182b is driven, an erroneous determination result may be obtained. After the second drive motor 182b is driven, the toner is transported and moved by the transport screw 62, and the toner amount detection sensor 111 gives a detection result, for example, there may be a variation of about 200 [ms] to 1000 [ms]. is there. Therefore, it becomes difficult to define X seconds after the second drive motor 182b is driven.

  Therefore, in the present embodiment, when the toner amount detection sensor 111 detects the absence of toner between the time when the second drive motor 182b is driven and the next time when the second drive motor 182b is driven, the first drive motor 182a is kept constant. Drive once per hour. As a result, a normal toner conveying operation can be performed without depending on the reaction variation of the toner amount detection of the toner amount detection sensor 111.

  In the present embodiment, the drive times of the toner replenishing device 60 and the first drive motor 182a are set so as to satisfy the relationship of Formula 1.

  In order to achieve this, in the present embodiment, a screw member is used as the toner conveying means to ensure a stable toner conveying amount. If the toner is transported from the toner container 32 to the sub hopper 63 only by the free fall of the toner, the toner transport amount is not stable, and the toner transport amount is excessive or insufficient.

  Here, if the amount of toner conveyed by one drive of the first drive motor 182a is smaller than the amount of toner conveyed by one drive of the second drive motor 182b, the toner in the sub hopper 63 will be used over time. There is a risk of running out of space.

  However, for such a problem, for example, an easy method is used such as performing filling control for transporting and filling the toner from the toner container 32 to the sub hopper 63 at a predetermined timing so that the sub hopper 63 is not emptied. Can be dealt with.

  On the other hand, if the amount of toner conveyed by one drive of the first drive motor 182a is larger than the amount of toner conveyed by one drive of the second drive motor 182b, the toner amount detection sensor 111 indicates that there is no toner. If false detection continues, it will fall into a fatal situation that is difficult to recover.

  That is, the amount of toner carried into the sub hopper 63 is larger than the amount of toner discharged from the sub hopper 63. Therefore, an amount of toner that greatly exceeds the capacity of the sub hopper 63 is conveyed from the toner container 32 to the sub hopper 63, and the toner overflows from the sub hopper 63 and the toner replenishing device 60 and the printer are covered with toner.

  FIG. 24A is a diagram illustrating a state where a space is temporarily generated in front of the sensor detection surface 111a of the toner amount detection sensor 111 and the toner has run out. FIG. 24B is a diagram illustrating a state in which the toner is transported by the mylar 112 a to the space generated in front of the sensor detection surface 111 a of the toner amount detection sensor 111.

  Despite the presence of a large amount of toner in the sub hopper 63 of the toner replenishing device 60, the toner amount detection sensor 111 detects that there is no toner because the toner is instantaneously lost in front of the sensor detection surface 111a of the toner amount detection sensor 111. And incorrect determination may be made.

  By performing the above-described drive control performed by the toner replenishing device 60 of the present embodiment, even if an erroneous determination is made once, a correct determination can be made the second time. It can suppress becoming excessive.

  This is because the mylar 112a, which plays a role in suppressing the toner from adhering to the sensor detection surface 111a of the toner amount detection sensor 111, has a function of transporting the toner to the space generated instantaneously before the sensor detection surface 111a. Because. Therefore, the toner is conveyed to the space by the mylar 112a while the second drive motor 182b is driven once or twice, and the control unit 100 correctly determines the presence or absence of toner based on the detection result of the toner amount detection sensor 111. be able to.

  In this way, if the control unit 100 can correctly determine the presence or absence of toner while the second drive motor 182b is driven twice, the toner in the toner dropping conveyance path 64 can be accommodated in consideration of the variation in the toner conveyance amount. The capacity can be set so as to satisfy the relationship of Equation 2.

  That is, the capacity of the toner drop conveyance path 64 that can accommodate the toner is set so that the first drive motor 182a is 5 times or more the maximum toner conveyance amount that can be conveyed by the conveyance screw 614 by one driving. As a result, since there is always no toner in the toner dropping conveyance path 64 extending in the vertical direction of the apparatus, it is difficult to actually occur, but even if the erroneous determination is made five times and the first drive motor 182a is driven too much. In addition, toner clogging does not occur in the toner drop conveyance path 64.

  1 and 25 are timing charts showing the relationship between the output timing of the toner amount detection sensor 111 and the drive timings of the second drive motor 182b and the first drive motor 182a in the present embodiment.

  FIG. 1 shows an example in which the second drive motor 182b is driven and the first drive motor 182a is also driven to change from the absence of toner to the presence of toner.

  On the other hand, in FIG. 25, when the second drive motor 182b is only driven and no toner is present, and when the second drive motor 182b is driven and the first drive motor 182a is also driven, no toner is present. This is an example of the case where there is.

  That is, in FIG. 25, by driving the second drive motor 182b, the toner is transported by the mylar 112a to the space generated in front of the sensor detection surface 111a of the toner amount detection sensor 111, and the toner is changed from no toner to toner presence. It includes the state.

  The second drive motor 182b is driven based on the output result of the toner amount detection sensor 111. In addition, the drive time for driving the first drive motor 182a once is longer than the drive time for driving the second drive motor 182b once.

  When the toner is consumed in the developing device 7 and the toner in the developing device 7 is reduced, the second drive motor 182b provided in the sub hopper side drive mechanism portion 181b of the toner replenishing device 60 is driven. Then, the output of the toner amount detection sensor 111 is observed during and after the second drive motor 182b is driven.

  If the toner amount detection sensor 111 detects “no toner”, the first drive motor 182a provided in the container-side drive mechanism 181a of the toner supply device 60 is driven once. At this time, since the second drive motor 182b is being driven and after being driven, the first drive motor 182a is driven a maximum of two times for one drive of the second drive motor 182b.

  Then, after the first drive motor 182a is driven and the toner is conveyed from the toner container 32 to the sub hopper 63, even if the toner amount detection sensor 111 outputs “no toner”, the second drive motor 182b is not driven next. As long as the first drive motor 182a is not driven.

  As described above, the output of the toner amount detection sensor 111 does not always change immediately after the second drive motor 182b is driven. That is, since the toner in the sub hopper 63 of the toner replenishing device 60 moves with a time difference after being driven, it cannot be specified that the output result after a few seconds after the second drive motor 182b is driven is referred to. This is because there is a possibility of erroneous detection if there is no toner amount detection sensor 111 despite the presence of toner in the sub hopper 63.

  Therefore, a flag indicating that the second drive motor 182b is driven is set during and after the second drive motor 182b is driven. This flag is cleared when the first drive motor 182a is driven. On the other hand, when the first drive motor 182a is not driven immediately after the flag indicating that the second drive motor 182b is driven, the flag is set until the first drive motor 182a is driven next. It is in the state.

  On the other hand, if the toner amount detection sensor 111 detects that “the toner is present” during and after the second drive motor 182b is driven, the first drive motor 182a is not driven.

  FIG. 26 is a flowchart relating to drive control performed by the control unit 100 of the toner amount detection sensor 111, the second drive motor 182b, and the first drive motor 182a.

  The toner amount detection sensor 111 always detects when the developing device 7 is operating (S1). On the other hand, as described above, the detection result is taken into the control unit 100 at the drive timing of the second drive motor 182b of the toner replenishing device 60. If the second drive motor 182b of the toner replenishing device 60 is not driven, the process returns to the constant detection of the presence / absence of toner by the toner amount detection sensor 111 without doing anything (NO in S2). On the other hand, if the second drive motor 182b of the toner replenishing device 60 is being driven or has been driven (YES in S2), the presence / absence of toner in the sub hopper 63 is determined based on the detection result of the toner amount detection sensor 111 (S3). ).

  The toner amount detection sensor 111 collects the detection of the presence or absence of toner about every 200 [ms]. In the present exemplary embodiment, when the number of toner out of 10 times is 8 or more in the detection, the control unit 100 determines that “no toner”. The number of collections is 10 times, and (8 times / 10 times) = 0.8 is the determination ratio. Then, “toner present” or “toner absent” is determined based on whether or not the determination ratio exceeds the threshold with respect to the latest 10 collections.

  If the determination ratio exceeds the threshold (YES in S3), it is determined that there is no toner, and the control unit 100 increments the toner end count by “+1”. The toner end count is a counter for determining that the toner container 32 has finally run out of toner. When the toner end count is “+1” (S4), the first drive motor 182a is driven once (S5).

  On the other hand, if the toner amount detection sensor 111 detects that the toner out of 10 times is 7 times or less, it is determined as “toner present” (NO in S3), and the toner end count is reset (cleared) (S11).

  Here, in order to determine whether or not the toner in the toner container 32 is really used up, the threshold value of the toner end counter is set to 80. For example, in order to set the “toner present” state when there is almost no toner in the sub hopper 63, the first drive motor 182 a must be driven at least several times to supply the toner from the toner container 32 to the sub hopper 63. In the meantime, the toner end count increases. Further, if the threshold value is small, the toner is exhausted even though the toner is still remaining in the toner container 32. Therefore, the threshold value is set to a sufficiently large value.

  When the toner end count has not reached 80 (NO in S6), the process returns to the detection of the presence or absence of toner by the toner amount detection sensor 111 (S1). On the other hand, when the toner end count reaches 80 or more (YES in S6), the drive for using up the toner in the toner container 32 is used for 5 [s] (S7). This is to drive the toner in the toner container 32 so as not to be used as much as possible. At this time, the toner amount detection sensor 111 detects the toner amount in the sub hopper 63 again, and if “no toner” (YES in S8), the control unit 100 determines that the toner container 32 is empty. Then, the drive of the first drive motor 182a is stopped (S9). On the other hand, if “toner is present” (NO in S8), the toner end count is reset (cleared), and the process returns to the detection of the presence or absence of toner by the toner amount detection sensor 111 (S1).

  Here, although the toner in the toner container 32 has been used up, toner of about 4 [g] to 5 [g], for example, remains in the sub hopper 63 and is in a printable state. Therefore, here, the status is not the toner end (complete stop) but the confirmed near end (S10).

  When the toner replenishing operation is performed on the developing device 7 by the toner replenishing device 60, the printing operation is performed while calculating how many [g] of toner is in the toner container 32. When the amount of toner calculation in the toner container 32 falls below a predetermined threshold, the status becomes an estimated near end, and notifies the user that a new toner container 32 should be prepared. This is called an estimated near end in this embodiment.

  On the other hand, at the determined near end as described above, the user is notified that there is no toner in the toner container 32. At the determined near end, the toner remains in the sub hopper 63 and printing is possible. However, the toner can be replaced with a new toner container 32.

  Then, when the toner in the sub hopper 63 is consumed from the determined near end, the toner end is reached, and the printing operation is disabled and the user is notified that the toner container 32 is to be replaced.

What has been described above is merely an example, and the present invention has a specific effect for each of the following modes.
(Aspect A)
A storage container such as a toner container 32 for storing powder, and a powder such as toner supplied from the storage container are temporarily stored, and discharged to the replenishment target through the temporarily stored powder. A container having a storage container such as a sub hopper 63 provided with an outlet, a first drive motor 182a for transporting powder from the storage container to a storage container through a powder transport path such as a toner dropping transport path 64, a transport screw 614, and the like. A first transport means such as a side drive mechanism 181a and a second hopper side drive mechanism 181b including a second drive motor 182b and a transport screw 62 that transport powder from a storage container to a replenishment target such as the developing device 7. A toner replenishing device comprising two conveying means and powder amount detecting means such as a toner amount detecting sensor 111 for detecting whether or not a predetermined amount of powder is present in the storage container; In a powder replenishing apparatus such as 60, when the second conveying means is driven once in the powder conveying operation for conveying a predetermined amount of powder, the powder amount detecting means detects no powder. And a control unit such as a control unit 100 that performs control to drive the first transport unit once in a powder transport operation of transporting an amount of powder not exceeding the predetermined amount.
In (Aspect A), when the second conveying means is driven once and the powder amount detecting means detects the absence of powder, the first conveying means is driven once, and the second conveying means is driven once. A quantity of powder not exceeding the quantity of powder to be conveyed is conveyed from the storage container to the storage container. As a result, even if the powder amount detecting means erroneously detects that there is no powder, the second conveying means is driven once and the powder is reduced in the storage container by transferring the powder from the storage container to the replenishment target. An amount of powder not exceeding the amount is only transported from the storage container to the storage container by a single drive of the first transport means. Therefore, regardless of whether or not the second conveying means is driven, if the powder amount detecting means detects the absence of powder, the first conveying means may be driven until it detects the presence of powder. It is detected that the powder is not excessively transferred from the storage container to the storage container and the storage container does not become full. Therefore, it is possible to suppress clogging of the powder conveyance path from the storage container to the storage container by excessively conveying the powder by the first conveying means.
If the amount of powder conveyed by one driving of the first conveying means is smaller than the amount of powder conveyed by one driving of the second conveying means, the powder in the storage container will be used over time. Disappears and becomes empty. However, for such a problem, for example, filling control for transferring and filling powder from the storage container to the storage container at a predetermined timing may be performed so that the storage container does not become empty.
(Aspect B)
In (Aspect A), the drive time for driving the first transport means once is longer than the drive time for driving the second transport means once. According to this, it can suppress that the powder in a storage container runs short.
(Aspect C)
In (Aspect A) or (Aspect B), it has a powder agitating means such as Mylar 112a that is driven in conjunction with the second conveying means and agitates the powder in the storage container. According to this, as described in the above embodiment, the powder is transported to the space generated instantaneously in front of the detection surface of the powder amount detection means, and erroneous detection of no powder is suppressed. can do.
(Aspect D)
In (Aspect A), (Aspect B), or (Aspect C), the capacity that can accommodate the powder in the powder conveyance path is the maximum amount of powder that the first conveyance means can convey in one drive. 5 times or more. According to this, as described in the above embodiment, even if the powder amount detection means detects twice, the capacity of the powder conveyance path is the maximum that the first conveyance means can convey with one drive. Since there is a margin more than 5 times the amount of powder, it is possible to suppress the occurrence of powder clogging in the powder conveyance path.
(Aspect E)
An image forming apparatus comprising: an image carrier; a developing unit that develops a latent image on the image carrier using a developer containing at least toner; and a toner replenishing unit that replenishes toner to the developing unit. As the toner replenishing means, the powder replenishing device of (Aspect A), (Aspect B), (Aspect C) or (Aspect D) is used. According to this, as described in the above embodiment, it is possible to suppress the occurrence of powder clogging in the powder conveyance path and to perform good image formation.

DESCRIPTION OF SYMBOLS 1 Process unit 2 Photoconductor unit 3 Photoconductor 4 Drum cleaning apparatus 5 Charging apparatus 6 Charging roller 7 Developing apparatus 8 First developer conveyance screw 9 First agent storage chamber 10 Toner density sensor 11 Second developer conveyance screw 12 Developing roll 13 Doctor blade 14 Second agent storage chamber 15 Developing sleeve 16 Magnet roller 17 Toner supply port 18 Communication port 19 Communication port 20 Optical writing unit 21 Polygon mirror 22 First paper feed cassette 22a First paper feed roller 23 Second paper feed Cassette 23a Second paper feed roller 24 Paper feed path 25 Transport roller pair 26 Registration roller pair 32 Toner container 33 Toner bottle 34 Container tip cover 34b Color incompatible rib 40 Transfer unit 41 Intermediate transfer belt 45 Primary transfer roller 46 Secondary transfer Backup low 47 Drive roller 49 Tension roller 50 Secondary transfer roller 60 Toner replenishing device 61 Toner transport path 62 Transport screw 63 Sub hopper 64 Toner drop transport path 65 Oscillating member 70 Container mounting section 71 Insert port forming section 72 Container receiving section 73 Tip receiving section Unit 80 fixing device 81 pressure heating roller 82 fixing belt unit 83 heating roller 84 fixing belt 85 tension roller 86 driving roller 87 paper discharge roller pair 88 stack unit 100 control unit 111 toner amount detection sensor 111a sensor detection surface 112a mylar 112b mylar 113a Rotating shaft 113b Rotating shaft 114 Rotating shaft 145 Drive transmission gear 146a Gear 146b Gear 147 Gear 160 Toner supply device 180 Drive mechanism 181a Container side drive mechanism 181b Sub hopper side drive Structure part 182a First drive motor 182b Second drive motor 301 Container rotation gear 302 Helical projection 303 Handle part 304 Pumping part 305 Tip opening forming part 330 Nozzle receiving member 331 Nozzle receiving port 332 Container shutter member 333 Container seal member 335b Shutter support Opening 336 Container shutter spring 339 Locking opening 601 Container drive output gear 602 Frame 603 Drive motor 603a Worm gear 604 Drive transmission gear 605 Conveying screw gear 607 Nozzle holder 608 Set cover 609 Container locking member 610 Nozzle opening 611 Conveying nozzle 611a Nozzle tip 612 Nozzle shutter member 612a Nozzle shutter collar 612b Nozzle shutter cylindrical portion 613 Nozzle shutter spring 614 Conveying screw 6 15 Container set part 700 chips

JP 2000-351445 A

Claims (5)

A storage container for storing powder;
A storage container provided with a discharge port for temporarily storing the powder supplied from the storage container and discharging the temporarily stored powder toward a replenishment target;
First transport means for transporting powder from the storage container to the storage container through a powder transport path;
Second conveying means for conveying powder from the storage container to the replenishment target;
In a powder replenishing device comprising a powder amount detecting means for detecting whether or not a predetermined amount of powder is present in the storage container,
While the second conveying unit is driven once in the powder conveying operation for conveying a predetermined amount of powder, the predetermined amount is not exceeded when the powder amount detecting unit detects no powder. A powder replenishing apparatus, comprising: a control means for controlling the first conveying means to be driven once in a powder conveying operation for conveying an amount of powder. The powder supply device according to claim 1, wherein
A powder replenishing device characterized in that the driving time for driving the first conveying means once is longer than the driving time for driving the second conveying means once. The powder supply device according to claim 1 or 2,
A powder replenishing device comprising powder agitation means that is driven in conjunction with the second conveying means to agitate the powder in the storage container. The powder supply device according to claim 1, 2 or 3,
The powder replenishing device, wherein a capacity capable of accommodating the powder in the powder conveying path is at least five times the maximum amount of powder that can be conveyed by the first conveying means by one driving. An image carrier;
Developing means for developing a latent image on the image carrier using a developer containing at least toner;
In an image forming apparatus comprising a toner replenishing means for replenishing toner to the developing means,
An image forming apparatus using the powder replenishing device according to claim 1 as the toner replenishing means.

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