JP5588946B2 - Toner supply device, toner container, and image forming apparatus - Google Patents

Description

  The present invention relates to a toner replenishing device, a toner container, and an image forming apparatus including the toner replenishing device and the toner container.

  Conventionally, in an electrophotographic image forming apparatus such as a copying machine, a printer, a facsimile, or a composite machine thereof, development processing is performed by supplying toner to an electrostatic latent image formed on the surface of a photosensitive drum or the like. Is going. In addition, toner used for such development processing is supplied to the surface of a photosensitive drum or the like from a toner supply device including a toner container such as a toner container and a developing device.

  When the development processing as described above is repeatedly performed, the toner in the toner container decreases accordingly, and when the toner in the toner container is exhausted, the toner container needs to be replaced. In order to know the replacement timing of the toner container, a general image forming apparatus is provided with means for detecting the toner concentration or the toner remaining amount in the toner container or the developing device. For example, a method (dot count method) for estimating the remaining amount of toner in the toner container based on the integrated value of the dot count at the time of image formation, or a toner container based on the integrated value of the rotation time (number of rotations) of the toner supply motor There is a method for estimating the toner remaining amount (see paragraph 0008 of Patent Document 1). These methods are widely used when a toner remaining amount sensor is not provided in the toner container, or when an intermediate hopper is not provided between the toner container and the developing device.

  When it is estimated that the remaining amount of toner in the toner container is in a small state by the above-described detection means, the user is notified that the toner in the toner container is in a near-end state, while remaining in the developing unit. An image forming operation is performed using the toner. The user replaces the toner container after the near-end warning until the toner end in which the toner in the developing device is substantially consumed and the apparatus stops.

JP 2009-31453 A

  A small-sized image forming apparatus with a small amount of toner that can be accommodated in the developing device when the near-end warning is issued after the toner in the toner container is exhausted and the printing from the near end to the toner end is performed with the toner in the developing device. In this case, the number of sheets that can be printed from the near end to the toner end is extremely small. Therefore, it is necessary for the user to prepare and set the next toner container immediately after the near end, and there is no time for replacing the toner container. In addition, if the number of prints from the near end to the toner end is excessively set, the toner density in the developing device becomes too low and the image density becomes low.

  In view of the above circumstances, an object of the present invention is to increase the number of printed sheets from the near end to the toner end and reduce the burden on the user when replacing the toner container.

  The toner replenishing device according to the present invention includes a toner container having a container main body that contains toner, a discharge port that is provided in the container main body and discharges the toner, and development to which toner discharged from the discharge port is supplied. A toner replenishing device comprising: a detector; a detecting means for detecting a toner concentration or a toner remaining amount in the toner container or the developing device; and a control means for receiving a signal from the detecting means. The toner container is disposed coaxially with the first rotating shaft, and a first stirring member having a first rotating shaft attached to the container body and a first stirring blade attached to the first rotating shaft. A second agitation member having a second rotation axis and a second agitation blade attached to the second rotation axis and having at least one of a length or a width larger than the first agitation blade, and the detection Based on the signal from the means Then, before the control means determines that the toner in the toner container is in a near-end state, the first stirring member is rotated and the second stirring member is stopped to rotate, based on a signal from the detection means. Then, after the control means determines that the toner in the toner container is in a near-end state, the second stirring member is rotated.

  According to such a configuration, the toner in the toner container is conveyed to the discharge port while being agitated by each agitating member. However, before the near-end determination in which only the first agitating member rotates, In this case, the toner remains in a portion where the first stirring blade does not reach. On the other hand, after the near-end determination, the toner remaining in the toner container can be directed to the discharge port by the second stirring blade by rotating the second stirring member. As a result, the amount of toner remaining in the toner container at the near end can be increased more than before, and the number of printed sheets from the near end to the toner end can be increased. Sufficient time for replacement can be secured, and the burden on the user can be reduced.

  In the toner replenishing device of the present invention, the first rotation shaft is provided from one end side to the other end side of the container body, and the first stirring blade is attached to an axially central portion of the first rotation shaft. The second rotating shaft is attached to the first rotating shaft on both sides of the first stirring blade, and the second stirring blade is attached at both ends to the second rotating shaft, It may be provided so as to surround the outer periphery.

  By adopting such a configuration, the first stirring member and the second stirring member can be rotated separately with a simple configuration.

  In the toner replenishing device according to the present invention, the developer includes a developer composed of toner and a carrier, and the detection unit is a toner concentration sensor capable of detecting a toner concentration in the developer. It may be attached.

  By adopting such a configuration, it is possible to estimate the remaining amount of toner in the toner container without providing a sensor in the toner container, and it is possible to simplify the configuration of the toner container that normally requires frequent replacement. It becomes possible.

  The toner replenishing device of the present invention comprises storage means for storing a toner density reference value, and the control means removes toner from the toner container from the toner container in a state where the discharge of toner from the developer is stopped for a certain period of time. After the treatment operation is performed, the toner concentration detected by the toner concentration sensor is compared with the reference value. When the toner concentration detected by the toner concentration sensor is not equal to or higher than the reference value, It may be determined that the toner in the toner container is in a near-end state.

  By adopting such a configuration, it is determined that the toner is in the near-end state after confirming that the remaining amount of toner in the toner container is small by the treatment operation. Therefore, it is possible to avoid the disadvantage that near-end display is performed even though a sufficient amount of toner remains in the toner container.

  In the toner replenishing device of the present invention, the toner container may be connected to the developing device without passing through another toner container.

  By adopting such a configuration, the configuration of the toner replenishing device can be simplified as compared with the case where the toner container and the developing device are connected via another toner container such as an intermediate hopper. It becomes possible to simplify the manufacturing process and reduce the manufacturing cost.

  The toner container of the present invention is a toner container having a container main body that contains toner, and a discharge port that is provided in the container main body and discharges the toner, and a first rotating shaft attached to the container main body, A first agitating member having a first agitating blade attached to the first rotating shaft, a second rotating shaft disposed coaxially with the first rotating shaft, and a long attached to the second rotating shaft. And a second agitating member having at least one of the width and the second agitating blade larger than the first agitating blade, and rotating the first agitating member before the toner is in a near-end state. After the rotation of the second stirring member is stopped and the toner is in the near end state, the second stirring member may be rotated.

  According to such a configuration, the toner in the toner container is conveyed to the discharge port side while being agitated by each agitating member, but before the near end where only the first agitating member is rotated, the toner is contained in the toner container. 1 The toner remains in a portion where the stirring blade does not reach. On the other hand, after the near end, the toner remaining in the toner container can be directed to the discharge port by the second stirring blade by rotating the second stirring member. Along with this, it is possible to increase the number of printed sheets from the near end to the toner end, so that it is possible to secure a sufficient time for replacement of the toner container, and the burden on the user can be reduced. .

  An image forming apparatus according to the present invention includes any one of the above-described toner supply devices or toner containers.

  The present invention makes it possible to increase the number of printed sheets from the near end to the toner end and reduce the burden on the user when replacing the toner container.

1 is a schematic diagram illustrating an outline of a configuration of a color printer according to an embodiment of the present invention. 1 is a cross-sectional view showing a toner replenishing device in a color printer according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a toner container in the color printer according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the vicinity of the front side wall of the toner container in the color printer according to the embodiment of the present invention. FIG. 6 is a cross-sectional view of the vicinity of the rear side wall of the toner container in the color printer according to the embodiment of the present invention. 1 is a block diagram illustrating an outline of a system configuration of a color printer according to an embodiment of the present invention. 6 is a flowchart illustrating toner replenishment control (before near-end) in the color printer according to the embodiment of the present invention. 6 is a flowchart illustrating toner supply control (during near-end) in the color printer according to the embodiment of the present invention. FIG. 6 is a cross-sectional view illustrating a state of the toner container immediately after the near-end display is performed in the color printer according to the embodiment of the present invention. 6 is a chart showing the number of printed sheets and the toner weight at an initial time, a near end, and a toner end for a conventional color printer (comparative example) and a color printer (example) according to the present invention.

  First, the overall configuration of the color printer 1 as an image forming apparatus will be described with reference to FIG. FIG. 1 is a schematic diagram illustrating an outline of a configuration of a color printer 1 according to an embodiment of the present invention.

  The color printer 1 includes a box-shaped printer main body 2. A paper feed cassette 3 storing transfer paper (not shown) is provided in the lower portion of the printer main body 2, and a discharge cassette is disposed in the upper portion of the printer main body 2. A paper tray 4 is provided.

  Inside the printer main body 2, an intermediate transfer belt 5 as an image carrier is installed between a driving roller 6 and a driven roller 7, and on the lower side of the intermediate transfer belt 5 (the lower left side in the drawing). An image density sensor 8 is arranged.

  Above the intermediate transfer belt 5, four image forming units 10 are provided for each toner color (for example, magenta, cyan, yellow, and black) along the upper surface of the intermediate transfer belt 5. In FIG. 1, only two image forming units 10 arranged on the left and right sides in the drawing are displayed, and the description of the two image forming units 10 arranged in the center in the left-right direction is omitted. Yes.

  Each image forming unit 10 is rotatably provided with a photosensitive drum 11 as an image carrier. The photosensitive drum 11 is formed using, for example, OPC or amorphous silicon. When using OPC, the film thickness is set to 20 μm to 40 μm in consideration of the balance between sensitivity and life. Around the photosensitive drum 11, there are a charger 12, an exposure device 13 composed of a laser scanning unit (LSU), a toner supply device 14, a primary transfer roller 15, a cleaning blade 16, and a static eliminator. 17 are arranged in the order of the primary transfer process. Details of the toner supply device 14 will be described later.

  A transfer paper transport path 18 is provided on one side (right side in the drawing) of the printer main body 2. A paper feeding unit 20 is provided at the upstream end of the conveyance path 18, and a secondary transfer roller 21 is provided at a middle portion of the conveyance path 18 so as to sandwich the intermediate transfer belt 5 between the driven roller 7 and the conveyance path 18. A fixing unit 22 is provided at a downstream portion of 18, and a paper discharge unit 23 is provided at a downstream end portion of the conveyance path 18.

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

  When the color printer 1 is turned on, various parameters are initialized, and initial settings such as temperature setting of the fixing unit 22 are executed. When image data is input from a computer or the like connected to the color printer 1 and an instruction to start printing is given, an image forming operation is executed as follows.

  First, after the photosensitive drum 11 is charged to a predetermined surface potential by the charger 12, exposure corresponding to image data is performed on the photosensitive drum 11 by the laser light from the exposure device 13, and the photosensitive drum 11. An electrostatic latent image is formed on the surface. Next, this electrostatic latent image is developed by a toner replenishing device 14 into a toner image of a corresponding color with toner, and is visualized. This toner image is primarily transferred onto the surface of the intermediate transfer belt 5 by the primary transfer roller 15. The above operation is sequentially repeated for each image forming unit 10 to form a full-color toner image on the intermediate transfer belt 5.

  On the other hand, the transfer paper taken out from the paper feed cassette 3 or the hand tray (not shown) by the paper feed unit 20 is conveyed to the secondary transfer roller 21 side in time with the above-described image forming operation. The full-color toner image on the intermediate transfer belt 5 is secondarily transferred onto the transfer paper by the next transfer roller 21. The transfer sheet on which the toner image is secondarily transferred is conveyed downstream in the conveyance path 18 and enters the fixing unit 22 where the toner image is fixed on the transfer sheet. The transfer paper on which the toner image is fixed is discharged from the paper discharge unit 23 onto the paper discharge tray 4.

  Note that the toner and charge remaining on the photosensitive drum 11 are removed by the cleaning blade 16 and the static eliminator 17, respectively. At the time of image density detection by calibration, a calibration toner image is formed and transferred to the intermediate transfer belt 5, and the density of this toner image is detected by the image density sensor 8.

  Next, the details of the toner replenishing device 14 will be described mainly with reference to FIGS. Hereinafter, for convenience, the front side in FIG. 2 (left side in FIG. 3) will be described as the front side (front side) of each member. FIG. 2 is a cross-sectional view showing a toner replenishing device in the color printer according to the embodiment of the present invention. FIG. 3 is a cross-sectional view showing a toner container in the color printer according to the embodiment of the present invention. FIG. 4 is a cross-sectional view of the vicinity of the front side wall of the toner container in the color printer according to the embodiment of the present invention. FIG. 5 is a cross-sectional view of the vicinity of the rear side wall of the toner container in the color printer according to the embodiment of the present invention. 3 has a section taken along the line AA in FIG. 2, and FIGS. 4 and 5 have a section taken along the line BB in FIG.

  As shown in FIG. 2, the toner replenishing device 14 includes a toner container 24 and a developing device 25 disposed below the toner container 24. For example, the toner container 24 is detachably attached to the developing device 25, and no other toner container such as an intermediate hopper is provided between the toner container 24 and the developing device 25.

  First, the toner container 24 will be described. The toner container 24 contains toner of different colors for each image forming unit 10 and is not provided with a means for detecting the remaining amount of toner.

  As best shown in FIG. 3, each toner container 24 includes a container main body 26 having an upper surface opened, and a lid body 27 that closes the opening of the container main body 26. A flange portion 28 is provided at the upper end of the container body 26, and the toner container 24 is closed by ultrasonically welding a lid 27 to the flange portion 28.

  The container body 26 has an elongated shape in the front-rear direction. A discharge port 30 is provided on the right side of the front end of the bottom of the container body 26. The discharge port 30 is closed by a sliding shutter (not shown) in a state where the toner container 24 is not attached to the developing device 25. The shutter is slid in association with the toner container 24 being attached to the developing device 25, and the discharge port 30 is opened.

A conveying screw 31 is rotatably provided in the container body 26 above the discharge port 30. The conveying screw 31 includes a rotating shaft 34 extending in the front-rear direction and a spiral fin 35 provided concentrically on the outer periphery of the rotating shaft 34. Both front and rear end portions of the rotating shaft 34 are inserted into shaft holes 36 and 37 respectively provided in the front and rear side walls 32 and 33 of the container body 26. Thereby, the conveyance screw 31 is rotatably supported by the container main body 26. A rear end portion of the rotating shaft 34 protrudes behind the rear side wall 33 of the container body 26, and a conveyance gear 38 is fixed to the protruding portion.

  The container body 26 is provided with a first agitation paddle 40 as a first agitation means and a second agitation paddle 41 as a second agitation means at the upper left of the conveying screw 31.

  The first stirring paddle 40 is attached to a first rotation shaft 42 provided from the front end side to the rear end side of the container body 26 and a central portion in the axial direction (front-rear direction in the present embodiment) of the first rotation shaft 42. And a stirring blade 43.

  The first rotating shaft 42 has a round bar shape that is long in the front-rear direction. As shown in FIG. 4, the front end portion of the first rotation shaft 42 is inserted through a front insertion hole 44 formed in the front side wall 32 of the container body 26, and as shown in FIG. 5, the first rotation shaft 42 is inserted. The rear end portion of 42 is inserted into a rear insertion hole 45 formed in the rear side wall 33 of the container body 26. Thereby, the first stirring paddle 40 is rotatably supported by the container body 26. The rear end portion of the first rotating shaft 42 protrudes behind the rear side wall 33 of the container body 26, and the first stirring gear 46 is fixed to the protruding portion.

  The 1st stirring blade 43 is formed using resin films, such as a PET film and a polyester film, for example, and has flexibility. The first stirring blade 43 has a rectangular shape that is long in the front-rear direction, and one long side portion 47 a is attached to the first rotation shaft 42.

  As shown in FIG. 3, the second stirring paddle 41 includes second rotating shafts 48 a and 48 b disposed coaxially with the first rotating shaft 42, and second stirring blades attached to the second rotating shafts 48 a and 48 b. 50.

  The second rotating shafts 48a and 48b have a cylindrical shape and are provided in a pair of front and rear. The second rotation shafts 48 a and 48 b are attached to the outer periphery of the first rotation shaft 42 on both the front and rear sides of the first stirring blade 43. In other words, the first rotating shaft 42 is inserted through the second rotating shafts 48 a and 48 b on both the front and rear sides of the first stirring blade 43. With such a configuration, the second stirring paddle 41 is rotatable relative to the container body 26 and the first stirring paddle 40.

  As shown in FIG. 4, the front end portion of the front second rotation shaft 48 a (hereinafter simply referred to as “second rotation shaft 48 a”) is a front insertion hole 44 provided in the front side wall 32 of the container body 26. The first rotating shaft 42 is inserted through the front side wall 32 and protrudes forward of the front side wall 32. A second agitation gear 51 is fixed to a portion protruding forward of the front side wall 32. As shown in FIG. 5, the rear second rotation shaft 48 b (hereinafter simply referred to as “second rotation shaft 48 b”) is inserted into the rear insertion hole 45 of the rear side wall 33 of the container body 26. It is not disposed in the container body 26.

  The rear end portion of the second rotation shaft 48a and the front end portion of the second rotation shaft 48b are connected by the core member 52. Thus, when the second rotation shaft 48a rotates, the second rotation shaft 48a is driven to follow the second rotation shaft 48a. 48b is configured to rotate. The core material 52 has a U-shape, and the outer peripheral portion of the first stirring blade 43 (the short side 54 on both the front and rear sides of the first stirring blade 43 and the long side not attached to the first rotating shaft 42) Part 47b) and a predetermined distance.

  The 2nd stirring blade 50 is formed using resin films, such as a PET film and a polyester film, for example, and has flexibility. Similar to the first stirring blade 43, the second stirring blade 50 has a long shape in the front-rear direction. The 2nd stirring blade 50 is provided with the connection part 55 extended in the front-back direction, and the attaching part 56 bent at substantially right angle from the front-and-rear both ends of this connection part 55, and has comprised the U shape. Each attachment portion 56 is attached to each second rotating shaft 48 a, 48 b on the opposite side of the connection portion 55. The inner peripheral portion of the second stirring blade 50 has a U-shape and is attached to the core member 52. The inner peripheral portion of the second stirring blade 50 is provided with a predetermined distance from the outer peripheral portion of the first stirring blade 43, and is provided so as to surround the outer peripheral portion of the first stirring blade 43.

  As shown in FIG. 3, the length L <b> 1 of the second stirring blade 50 (the length in the front-rear direction in the present embodiment) is larger than the length L <b> 2 of the first stirring blade 43. As shown in FIG. 4, the width W1 of the second stirring blade 50 (in this embodiment, the maximum width from the axis P of the first rotating shaft 42 and the second rotating shafts 48a and 48b) is the first stirring blade 50. It is larger than 43 width W2.

  Next, the developing unit 25 will be described. The developing unit 25 adopts a two-component developing system, and stores developer composed of toner and carrier. As shown in FIG. The outer periphery is covered, and an opening 59 is provided at the left end of the casing 58.

  On the upper plate of the casing 58, an introduction port 60 is provided at a position corresponding to the discharge port 30 of the toner container 24. Below the introduction port 60, a pair of left and right stirring mixer paddles 61a and 61b are rotatable. It is stored in. The stirring mixer paddles 61a and 61b are arranged in a state separated by a partition wall 62 standing in the casing 58, and the developer in the developing device 25 is circulated by the stirring mixer paddles 61a and 61b. ing.

  A toner concentration sensor 63 as a detecting means is provided on the right side of the right stirring mixer paddle 61b (hereinafter simply referred to as “stirring mixer paddle 61b”). The toner concentration sensor 63 is, for example, a magnetic permeability sensor, and is configured to measure the magnetic permeability of the developer stored in the developing device 25 and detect the toner concentration from the mixing ratio of the toner and the carrier. . A sensor cleaner 64 is attached to the stirring mixer paddle 61b. The sensor cleaner 64 is provided at a position where it can come into contact with the toner concentration sensor 63, and is configured to slide in contact with the toner concentration sensor 63 as the stirring mixer paddle 61 b rotates to clean the surface of the toner concentration sensor 63. ing.

  A developing roller 65 (developer carrier) is provided on the left side of the left stirring mixer paddle 61a so as to partially expose the opening 59. The developing roller 65 has, for example, a rotatable sleeve containing a fixed magnet. A developer regulating blade 66 is disposed above the developing roller 65, and the developer whose flow rate is adjusted by the developer regulating blade 66 is held by the developing roller 65 and faces the developing roller 65. To be supplied. The developer supplied to the photosensitive drum 11 is replaced by stirring mixer paddles 61a and 61b.

  Next, the control system of the color printer 1 will be described mainly with reference to FIG. FIG. 6 is a block diagram showing an outline of the system configuration of the color printer according to the embodiment of the present invention.

  The color printer 1 is provided with a CPU 71 as control means. The CPU 71 is connected to a storage means 72 composed of a storage device such as a ROM and a RAM, and the CPU 71 controls each part of the color printer 1 based on a control program and control data stored in the storage means 72. Configured to do. In the storage unit 72, for example, a toner density (hereinafter referred to as “first lower limit density”) that serves as a reference for supplying toner from the toner container 24 to the developing device 25, and a predetermined value from the first lower limit density are set. The toner density calculated by subtraction (hereinafter referred to as “second lower limit density”) is stored.

  The CPU 71 is connected to an operation display unit 73 provided in the printer main body 2. The operation display unit 73 is provided with operation keys such as a start key, a stop / clear key, a power key, a numeric keypad, and a touch panel. For example, when the user operates each operation key, the operation instruction is output to the CPU 71. It is configured. Further, various information such as an error message is displayed on the operation display unit 73 based on a signal output from the CPU 71.

  The CPU 71 is connected to the image density sensor 8 and the toner density sensor 63, and is configured such that the CPU 71 receives signals from the image density sensor 8 and the toner density sensor 63.

  The CPU 71 is connected to the transport motor 75 via the motor drive unit 74, and the transport motor 75 is connected to the transport gear 38. Then, when a current is passed from the motor drive unit 74 to the transport motor 75 based on the drive command signal from the CPU 71, the transport motor 75 rotates, and the rotation of the transport motor 75 is transmitted to the transport gear 38 to be transported. Is configured to rotate.

  The CPU 71 is connected to the first stirring motor 76 via the motor drive unit 74, and the first stirring motor 76 is connected to the first stirring gear 46. The first agitation motor 76 is rotated by passing a current from the motor drive unit 74 to the first agitation motor 76 based on the drive command signal from the CPU 71, and the rotation of the first agitation motor 76 is the first agitation gear 76. 46, the first agitation gear 46 is configured to rotate.

  The CPU 71 is connected to the second stirring motor 77 via the motor drive unit 74, and the second stirring motor 77 is connected to the second stirring gear 51. Then, based on a drive command signal from the CPU 71, a current is passed from the motor drive unit 74 to the second agitation motor 77, whereby the second agitation motor 77 is rotated, and the rotation of the second agitation motor 77 is the second agitation gear. The second agitation gear 51 is rotated by being transmitted to 51.

  The toner replenishment control in the color printer 1 configured as described above will be described mainly with reference to FIGS. FIG. 7 is a flowchart showing toner supply control (before near-end) in the color printer according to the embodiment of the present invention. FIG. 8 is a flowchart showing toner replenishment control (during near end) in the color printer according to the embodiment of the present invention. FIG. 9 is a cross-sectional view showing the state of the toner container immediately after it is determined that it is in the near end state in the color printer according to the embodiment of the present invention. Note that the paddle names displayed in parentheses in some steps of FIGS. 7 and 8 indicate the paddles rotating in that step.

  In the above configuration, when image output is performed (S101), the toner density sensor 63 detects the toner density in the developing device 25 (S102), and outputs this detection signal to the CPU 71. The CPU 71 compares the toner density detected by the toner density sensor 63 (hereinafter abbreviated as “detected toner density”) with the first lower limit density stored in the storage means 72, and the detected toner density is determined. It is determined whether it is lower than the first lower limit concentration (S103). If this determination is NO, the CPU 71 determines that the toner density in the developing device 25 is sufficient. Accordingly, an image is output without toner replenishment (S101).

  On the other hand, when the determination in S103 is YES, the CPU 71 compares the detected toner density with the second lower limit density stored in the storage unit 72, and the detected toner density is equal to or lower than the second lower limit density. It is determined whether or not (S104). When this determination is NO, the CPU 71 transmits a drive command signal to the motor drive unit 74 to drive the first agitation motor 76 and the transport motor 75.

  As the first stirring motor 76 is driven, the driving force of the first stirring motor 76 is transmitted to the first stirring gear 46, and the first stirring paddle 40 rotates in the direction indicated by the arrow in FIG. As a result, the toner in the toner container 24 is conveyed toward the conveying screw 31 while being agitated.

  In addition, with the driving of the transport motor 75 described above, the driving force of the transport motor 75 is transmitted to the transport gear 38 and the transport screw 31 rotates. As a result, the toner in the toner container 24 is introduced into the developing device 25 from the discharge port 30, and the toner is supplied to the developing device 25 (S105). This toner replenishment (S105) is performed while continuing printing. Further, in this toner replenishment (S105), since the second stirring motor 77 is not driven, the rotation of the second stirring paddle 41 is stopped. When the above-described toner supply (S105) is completed, the process returns to step S101 and image output is performed.

  On the other hand, if the determination in S104 is YES, the CPU 71 determines that the remaining amount of toner in the toner container 24 has decreased and the amount of toner replenished from the toner container 24 to the developing device 25 has decreased. Then, a “treatment operation” for supplying toner from the toner container 24 to the developing device 25 is performed in a state where the discharge of the toner from the developing device 25 is stopped for a certain time (printing is stopped for a certain time) (S106). This treatment operation (S106) is performed while rotating the first stirring paddle 40 and the conveying screw 31 as in the toner replenishment (S105), and the rotation of the second stirring paddle 41 is stopped.

  When the above-described treatment operation (S106) is completed, the toner concentration in the developing device 25 is detected by the toner concentration sensor 63 (S107). The CPU 71 compares the detected toner density with a reference value (for example, the first lower limit density) stored in the storage unit 72, and determines whether or not the detected toner density is equal to or higher than the reference value (S108). . If the determination in S108 is YES, the process returns to step S101 and image output is performed.

  On the other hand, when the state of step S108 described above is NO (state in which the detected toner density is lower than the reference value described above) continues for a predetermined time, the CPU 71 determines that the toner in the toner container 24 is in the near-end state ( It is determined that the toner density is not recovered even if the toner is replenished while rotating the first stirring paddle 40 (S109), and control at the near end (see FIG. 8) is performed.

  The control at the near end will be further described. First, the CPU 71 outputs a signal to the operation display unit 73 to display on the operation display unit 73 a near end display such as “the toner is very low” (S201). This prompts the user to replace the toner container 24.

  In this way, near-end display is performed, and the CPU 71 transmits a drive command signal to the motor drive unit 74 to drive the second stirring motor 77 and the transport motor 75 (the first stirring motor 76 is not driven).

  As the second stirring motor 77 is driven, the driving force of the second stirring motor 77 is transmitted to the second stirring gear 51, and the second stirring paddle 41 rotates in the direction indicated by the arrow in FIG. As a result, the toner in the toner container 24 is conveyed toward the conveying screw 31 while being agitated. In the toner replenishment (S105) and the treatment operation (S106), since only the first stirring paddle 40 is rotating, the first stirring blade 43 arrives in the toner container 24 immediately after the near end display. The toner remains in the non-existing portion (the remaining toner is indicated by arrow t in FIG. 9). The remaining toner flows toward the discharge port 30 by the second stirring blade 50 as the second stirring paddle 41 rotates.

  In addition, with the driving of the transport motor 75 described above, the driving force of the transport motor 75 is transmitted to the transport gear 38 and the transport screw 31 rotates. As a result, the toner in the toner container 24 is introduced into the developing device 25 through the discharge port 30, and toner is supplied to the developing device 25 (S202).

  When toner supply to the developing device 25 is completed, image output (S203) is performed. When the image output (S203) is completed, the toner density sensor 63 detects the toner density in the developing device 25 (S204), and outputs this detection signal to the CPU 71. The CPU 71 compares the detected toner density with the first lower limit density stored in the storage means 72, and determines whether or not the detected toner density is lower than the first lower limit density (S205). If this determination is NO, the CPU 71 determines that the toner density in the developing device 25 is sufficient. Accordingly, image output is performed without toner replenishment (S203).

  On the other hand, if the determination in S205 is YES, the CPU 71 compares the detected toner density with the second lower limit density stored in the storage means 72, and the detected toner density is equal to or lower than the second lower limit density. It is determined whether or not (S206). When this determination is NO, the CPU 71 transmits a drive command signal to the motor drive unit 74 to drive the second agitation motor 77 and the transport motor 75, and the second agitation paddle as in the toner replenishment (S202). 41 and the conveying screw 31 are rotated to replenish toner (S207).

  On the other hand, if the determination in S206 is YES, the CPU 71 determines that the remaining amount of toner in the toner container 24 has decreased and the amount of toner replenished from the toner container 24 to the developing device 25 has decreased. Then, a treatment operation is performed (S208). This treatment operation (S208) is performed while rotating the second stirring paddle 41 and the conveying screw 31 as in the toner replenishment (S202, S207), and the rotation of the first stirring paddle 40 is stopped.

  When the above treatment operation (S208) is completed, the toner concentration in the developing unit 25 is detected by the toner concentration sensor 63 (S209). The CPU 71 compares the detected toner density with a reference value (for example, the first lower limit density) stored in the storage unit 72, and determines whether or not the detected toner density is equal to or higher than the reference value (S210). ). If the determination in S210 is YES, the process returns to step S203 and image output is performed.

  On the other hand, if the above step of S210 is NO, the CPU 71 determines that there is no toner in the toner container 24, and outputs a signal to the operation display unit 73, for example, a toner end such as “no toner”. The display is displayed on the operation display unit 73, and the color printer 1 is stopped (S211).

  When the cover (not shown) of the printer main body 2 is opened / closed after the near end display (S201) or the power switch of the color printer 1 is turned off / on, the toner container 24 is replaced. There is a possibility. In this case, a treatment operation is performed by one or both of the first stirring paddle 40 and the second stirring paddle 41, and the toner concentration in the developing device 25 is detected by the toner concentration sensor 63. When the toner density is restored to a reference value (for example, the first lower limit density) or more, the near-end display and the toner-end display are canceled and the process proceeds to normal image output (S101). Thereafter, only the first agitation paddle 40 is rotated to supply toner.

  As described above, in this embodiment, before the CPU 71 determines that the toner in the toner container 24 is in the near-end state, the first stirring paddle 40 is rotated and the rotation of the second stirring paddle 41 is stopped to After the CPU 71 determines that the toner in the container 24 is in the near-end state, the second stirring paddle 41 is rotated and the rotation of the first stirring paddle 40 is stopped. With such a configuration, at the near end, the toner remains in a portion where the first stirring blade 43 does not reach in the toner container 24, and the amount of toner remaining in the toner container 24 at the near end is larger than that of the conventional case. Can be increased. Accordingly, the number of printed sheets from the near end to the toner end can be increased, so that a sufficient time for replacing the toner container 24 can be secured and the burden on the user can be reduced. it can.

  Moreover, in this embodiment, the 1st rotating shaft 42 is provided from the front end side of the container main body 26 to the rear end side, the 1st stirring blade 43 is attached to the axial direction center part of the 1st rotating shaft 42, and 2nd rotation The shafts 48 a and 48 b are attached to the first rotating shaft 42 on both sides of the first stirring blade 43, and the second stirring blade 50 is attached to the second rotating shafts 48 a and 48 b at both ends so that the outer periphery of the first stirring blade 43 It is provided so as to surround. By adopting such a configuration, the first stirring paddle 40 and the second stirring paddle 41 can be separately rotated with a simple configuration.

  In the present embodiment, the toner density sensor 63 is provided in the developing device 25. By adopting such a configuration, it is possible to estimate the toner remaining amount in the toner container 24 without providing the toner remaining amount sensor in the toner container 24, and the toner container 24 that needs to be frequently replaced can be estimated. The configuration can be simplified.

  Further, in this embodiment, since it is determined that the amount of toner remaining in the toner container 24 is very small after the treatment operation, it is determined that the toner container 24 is in the near-end state. It is possible to avoid the disadvantage that the near-end display is performed even though the toner remains.

  In this embodiment, since the toner container 24 is connected to the developing unit 25 without passing through another toner container such as an intermediate hopper, the configuration of the toner replenishing device 14 can be simplified. It becomes possible to simplify the manufacturing process and reduce the manufacturing cost.

  In the present embodiment, the case where only the second agitation paddle 41 is rotated after the CPU 71 determines that the toner in the toner container 24 is near-end has been described. Both the first stirring paddle 40 and the second stirring paddle 41 may be rotated after it is determined that the toner in the container 24 is near-end.

  In the present embodiment, the case where the first rotation shaft 42 and the second rotation shafts 48a and 48b are directly supported by the front and rear side walls 32 and 33 of the container body 26 has been described. However, in another different embodiment, the first rotation The shaft 42 and the second rotation shafts 48a and 48b may be supported on the front and rear side walls 32 and 33 of the container body 26 via bearings (not shown).

  In the present embodiment, the case where the second rotating shaft 48 a and the second rotating shaft 48 b are connected by the core member 52 has been described. However, in another different embodiment, the second rotating shaft 48 a is provided without providing the core member 52. And the second rotating shaft 48b may be connected only through the second stirring blade 50.

  In this embodiment, although the case where both the length and width of the 2nd stirring blade 50 were larger than the 1st stirring blade 43 was demonstrated, in another different embodiment, the length of the 2nd stirring blade 50 or blade | wing Only one of them may be larger than the first stirring blade 43.

  In the present embodiment, the case where the second stirring gear 51 and the first stirring gear 46 are arranged on the front side and the rear side of the toner container 24, respectively, has been described. However, in other different embodiments, the front side or the rear side of the toner container 24 is described. You may arrange | position both the 1st stirring gear 46 and the 2nd stirring gear 51 in any one of the side.

  In the present embodiment, the configuration in which the toner concentration in the toner container 24 is detected by the toner concentration sensor 63 attached to the developing device 25 has been described. However, in another different embodiment, the piezoelectric device attached to the toner container 24 or the developing device 25. The remaining amount of toner and the toner density in the toner container 24 may be detected by other different detection means such as a sensor and an optical sensor.

  In the present embodiment, the two-component development method including the toner and the magnetic carrier has been described. However, when the toner density sensor 63 is not used, a one-component development method that does not include a carrier may be used.

  In this embodiment, the case of using a slide-type shutter has been described. However, in another different embodiment, after the toner container 24 is mounted on the developing device 25 and the lever is unlocked, the user can operate the lever. A rotary shutter in which the shutter rotates in conjunction with the discharge port 30 may be used.

  In the present embodiment, the case where the toner container 24 is directly connected to the developing device 25 has been described. However, in another different embodiment, the toner container 24 is connected to the developing device 25 via another toner container such as an intermediate hopper. May be. In this case, the configuration of the present invention may be applied to other toner containers such as an intermediate hopper.

  In the present embodiment, the case where the configuration of the present invention is applied to the tandem color printer 1 has been described. However, in other different embodiments, the rotary color printer 1, the monochrome printer, the copying machine, the digital multifunction peripheral, and the facsimile machine are used. It is also possible to apply the configuration of the present invention to other image forming apparatuses.

(Comparative experiment)
An experiment was performed to compare the number of printed sheets from the near end to the toner end for the conventional toner container (comparative example) and the toner container (example) according to the present invention.

  For the comparative example, a toner container having only a single stirring paddle is prepared, and when the toner in the toner container becomes small, the toner container is used as a near end, and after printing to such an extent that the image density does not decrease, the toner is printed. It was an end.

  On the other hand, for the example, a toner container having the same configuration as that of the above embodiment provided with the first stirring paddle and the second stirring paddle was prepared. When the toner concentration does not recover even if the toner is replenished while rotating the first agitation paddle, the toner is replenished while the second agitation paddle is rotated so that the image density does not decrease. The toner end was determined after printing.

  In this experiment, evaluation was performed by filling a toner container with an amount of toner capable of printing 2000 sheets with an original with a printing rate of 5%, and continuously printing the original with 5%. FIG. 10 shows the toner weight and the number of printed sheets in the toner container at the initial time, near end, and toner end for the comparative example and the example. In the comparative example, since the toner weight in the toner container was very small at the near end, only 29 sheets could be printed from the near end to the toner end. On the other hand, in the configuration of the present invention, toner having a weight twice or more that of the comparative example remains in the toner container at the near end, and therefore, 340 sheets can be printed from the near end to the toner end.

  As described above, according to the configuration of the present invention, the remaining amount of toner in the toner container at the near end can be increased more than before, and the number of printed sheets from the near end to the toner end can be increased. Along with this, it is possible to secure a sufficient time for the user to replace the toner container, and the burden on the user can be reduced.

1 Color printer (image forming device)
14 Toner supply device 24 Toner container (toner container)
25 Developing device 26 Container body 30 Discharge port 40 First stirring paddle (first stirring member)
41 Second stirring paddle (second stirring member)
42 1st rotating shaft 43 1st stirring blade 48 2nd rotating shaft 50 2nd stirring blade 63 Toner density sensor (detection means)
71 CPU (control means)
72 Memory means

Claims (7)

A toner container having a container main body for containing toner, and a discharge port provided in the container main body for discharging toner;
A developing device to which toner discharged from the discharge port is supplied;
Detecting means for detecting the toner concentration or the remaining amount of toner in the toner container or the developing device;
A toner replenishing device comprising a control means for receiving a signal from the detecting means,
The toner container includes:
A first stirring member having a first rotating shaft attached to the container body, and a first stirring blade attached to the first rotating shaft;
A second rotating shaft disposed coaxially with the first rotating shaft; and a second stirring blade attached to the second rotating shaft and having at least one of a length or a width larger than the first stirring blade. A second stirring member having
Before the control means determines that the toner in the toner container is in a near-end state based on a signal from the detection means, the first stirring member is rotated and the second stirring member is stopped,
A toner replenishing device that rotates the second stirring member after the control means determines that the toner in the toner container is in a near-end state based on a signal from the detection means. The first rotation shaft is provided from one end side to the other end side of the container body,
The first stirring blade is attached to an axially central portion of the first rotating shaft,
The second rotation shaft is attached to the first rotation shaft on both sides of the first stirring blade,
2. The toner replenishing device according to claim 1, wherein both ends of the second stirring blade are attached to the second rotation shafts so as to surround an outer periphery of the first stirring blade. . The developer contains a developer composed of toner and carrier,
The toner replenishing device according to claim 1, wherein the detection unit is a toner concentration sensor capable of detecting a toner concentration in the developer, and is attached to the developing device. A storage means for storing a toner density reference value;
The control means is configured to detect the toner detected by the toner concentration sensor after a treatment operation for supplying the toner from the toner container to the developer is performed in a state where the discharge of the toner from the developer is stopped for a predetermined time. 4. The density and the reference value are compared, and when the toner density detected by the toner density sensor is not equal to or higher than the reference value, it is determined that the toner in the toner container is in a near-end state. The toner replenishing device according to 1.   The toner replenishing device according to claim 1, wherein the toner container is connected to the developing unit without passing through another toner container. A toner container having a container main body for storing toner, and a discharge port provided in the container main body for discharging toner,
A developing unit to which the toner discharged from the discharge port is supplied; a detecting unit for detecting a toner concentration or a toner remaining amount in the toner container or the developing unit; and a control unit for receiving a signal from the detecting unit And provided in a toner replenishing device comprising:
A first stirring member having a first rotating shaft attached to the container body, and a first stirring blade attached to the first rotating shaft;
A second rotating shaft disposed coaxially with the first rotating shaft; and a second stirring blade attached to the second rotating shaft and having at least one of a length or a width larger than the first stirring blade. A second stirring member having
Before the control means determines that the toner in the toner container is in a near-end state based on a signal from the detection means , the first stirring member is rotated and the second stirring member is stopped,
A toner container , wherein the second stirring member is rotated after the control means determines that the toner in the toner container is in a near-end state based on a signal from the detection means .   An image forming apparatus comprising the toner supply device according to claim 1 or the toner container according to claim 6.