JP4568587B2 - Image forming apparatus, image forming method, toner conveying apparatus, and toner conveying method - Google Patents

Description

  The present invention relates to an image forming apparatus such as a printer, a copying machine, and a facsimile. More specifically, the present invention relates to an image forming method using the image forming apparatus, a toner conveying device including a toner containing unit and a toner conveying unit, and a toner conveying device. The present invention relates to a toner conveying method.

  A developer carrier that carries a developer on its surface and conveys it to a development area facing an image carrier (for example, a photoreceptor or an intermediate transfer member), and a developer container that contains the developer (toner or toner and carrier) A developing device that supplies toner in the developer accommodating portion to the developer carrying member or the developer carried on the developer carrying member, and a toner container that replenishes the developer containing portion with toner. In the image forming apparatus, the greatest purpose of replenishing the toner is to replenish and supply the amount of toner conveyed to the image carrier by the image output in order to keep the toner density in the developer accommodating portion constant. If the amount of toner to be supplied is too large, a high density image is generated due to toner scattering or an increase in toner density in the developer accommodating portion. Further, if the toner is excessively replenished, the stirring function of the toner and the carrier performed in the developer accommodating portion may not work and a uniform developer may not be produced. Conversely, if the amount of toner supplied to the image carrier is too small, carrier adhesion may occur during low density image formation or image formation. Therefore, the biggest problem of toner replenishment is to reliably replenish the toner amount required by the developer accommodating portion and to keep the toner density in the developer accommodating portion constant (see, for example, Patent Documents 1 and 2). .

  Japanese Patent Application Laid-Open No. 7-146605 proposes a technique in which a magnet seal is disposed to prevent toner scattering that occurs at a connecting portion between a toner receiving port of a developing device and a toner conveying device discharge port. Japanese Patent Application Laid-Open No. 2002-268353 discloses a developing device in which a toner containing portion and a developer containing portion are integrated for the purpose of preventing toner density overshoot at the time of developing device initialization and preventing toner scattering. A technique has been proposed in which a seal member is attached in advance.

  On the other hand, the image forming apparatus includes a developer carrying member and a developer containing portion, and includes a developing device that supplies the developer carrying member or the toner carried on the developer carrying member to the toner in the developer containing portion. The process cartridge and the toner container are individually detachable from the main body of the image forming apparatus, and serve as a toner transport unit that transports toner from the toner container to the developer container using its own weight. An image forming apparatus in which a toner conveying device is provided in a main body of the image forming apparatus is known (for example, see Patent Document 3).

JP 7-146605 A JP 2002-268353 A JP 2004-139031 A

  However, the image forming apparatus includes a developing device, a toner container, and a toner transport device, and the developing device and the toner container are individually detachable from the main body of the image forming apparatus (for example, Japanese Patent Laid-Open No. 2004-2004). No. 139031), no new technical proposal has been made to keep the toner concentration in the developer accommodating portion constant and prevent toner scattering when the toner conveying device in which no toner exists in the toner conveying device is initially driven. .

SUMMARY OF THE INVENTION Accordingly, the present invention provides an image forming apparatus having the configuration described in the above-mentioned problem column, in which toner developer is accommodated without using a magnet seal or a seal member at the time of initial driving of the toner conveying apparatus in which no toner exists in the toner conveying apparatus. The main object of the present invention is to provide an image forming apparatus, an image forming method, a toner conveying apparatus, and a toner conveying method capable of preventing the toner density fluctuation and the toner scattering as described above by preventing the toner from flowing into the portion. that aims.

According to a first aspect of the present invention, there is provided an image carrier, a developing means having a developer containing portion for containing the agent carrying means and the developer, a toner containing means for supplying toner to the developer containing portion, and the toner A toner conveying means for conveying toner from the accommodating means to the developer accommodating portion via a toner conveying path, and the developing means and the toner accommodating means are individually detachable from the image forming apparatus main body. In the configured image forming apparatus, the toner transport unit includes a toner transport pipe that forms the toner transport path, and one end that is substantially inscribed in the toner transport pipe. A transfer coil as a toner transfer member to be moved, a rotating member to which the other end of the transfer coil is fixed, and drive means for rotationally driving the rotating member. Using the weight are arranged to perform a toner transport, the time of initial driving of the conveying means on which the toner does not exist in the previously conveying means, the toner from the toner accommodating means to the developer containing portion Carrier or developer is retained in advance in the vicinity of the upstream side in the toner transport tube in which one end of the transport coil is accommodated to such an extent that it does not flow, and the carrier or developer that has been retained in advance during the initial drive. The initial toner filling control for transporting the toner to the developer accommodating portion and filling the toner conveying path with the toner by the toner conveying means causes the toner to flow from the toner accommodating means to the developer accommodating portion. It is characterized in that it is not continuous driving but intermittent driving in which toner does not flow .
Here, “to the extent that toner does not flow” means that there is no slight gap through which toner flows in the toner conveyance path (the same applies hereinafter).
The term “before the initial driving” in claim 1 includes processing / operation in which a carrier or developer is retained in a predetermined part in the toner transport path in advance during, for example, disassembly and repair in a service or the like ( The same applies hereinafter).
In addition, in the “toner conveying means for conveying toner from the toner accommodating means to the developer accommodating portion via the toner conveying path” according to claim 1, for example, the toner is conveyed by utilizing its own weight. In other words, it also includes a toner conveying unit that forcibly conveys toner against gravity (hereinafter the same).

According to a second aspect of the invention, in the image forming apparatus according to claim 1, in the initial driving time previously, it said to include the factory of the image forming apparatus.

According to a third aspect of the present invention, in the image forming apparatus according to the first or second aspect , the number of intermittent driving operations in the initial toner filling control is set in a range in which toner is not replenished to the developer containing portion. And
According to a fourth aspect of the present invention, in the image forming apparatus according to any one of the first to third aspects, the staying amount of the carrier or the developer staying in advance does not hinder the developing operation by the developing unit. It is set within the range.

According to a fifth aspect of the present invention, there is provided an image forming method using the image forming apparatus according to any one of the first to fourth aspects.

The invention described in claim 6 is detachable from the image forming apparatus main body for replenishing toner to the developer accommodating portion of the developing means having the developer carrying means and the developer accommodating portion for accommodating the developer. A toner conveying device comprising: a configured toner accommodating unit; and a toner conveying unit disposed in the main body of the image forming apparatus and configured to convey toner from the toner accommodating unit to the developer accommodating unit via a toner conveying path. The toner conveying device is used in an image forming apparatus according to any one of claims 1 to 4 .

The invention according to claim 7 is detachable from the image forming apparatus main body for replenishing toner to the developer accommodating portion of the developing means having the developer carrying means and the developer accommodating portion for accommodating the developer. A toner conveying device having a configured toner accommodating unit and a toner conveying unit disposed in the main body of the image forming apparatus and configured to convey toner from the toner accommodating unit to the developer accommodating unit via a toner conveying path is used. In the toner transport method, the toner transport method is used in the image forming method according to claim 5 .

According to the present invention, the configuration described in each claim can solve the above problems and provide a novel image forming apparatus, image forming method, toner conveying apparatus, and toner conveying method. The main effects of the invention are as follows.
According to the first, second, fourth, and seventh aspects of the present invention, the above configuration eliminates the use of, for example, a conventional magnet seal or a seal member at the time of initial driving of the toner conveying device in which no toner exists in the toner conveying device. It can also be prevented from flowing into the developer accommodating portion of the toner, namely when wearing sets the toner storage means to the image forming apparatus main body at the time of initial driving, and preventing the flow of the developer accommodating portion of the toner In addition, the initial toner filling control for filling the toner into the toner conveying path by the toner conveying means is not continuous driving in which the toner flows from the toner accommodating means to the developer accommodating portion, but the toner flowing occurs. In this way, it is possible to prevent the toner from flowing and becoming easier to flow during continuous driving. .

According to the invention described in any one of claims 3 and 5 to 7, the number of intermittent driving operations in the initial toner filling control is set in a range in which the toner is not replenished to the developer accommodating portion. The toner concentration in the developer accommodating portion during driving can be kept constant.

  Embodiments of the present invention will be described below with reference to the drawings. Constituent elements such as members and components having the same function and shape throughout the embodiment and the modified examples are given the same reference numerals and will not be described after being described once. In order to simplify the drawings and the description, even components that are to be represented in the drawings may be omitted as appropriate without being specifically described in the drawings. When quoting and explaining constituent elements such as published patent gazettes, the reference numerals are shown in parentheses to distinguish them from those of the embodiments.

  In this embodiment, the image forming apparatus is a color printer (hereinafter abbreviated as “printer”) that can form a full-color image by employing a tandem method.

First, the basic configuration and operation of the printer will be described with reference to FIG. 1, and the components unique to the present embodiment will be described thereafter. The printer shown in FIG. 1 basically has the same configuration as an electrophotographic printer disclosed in, for example, Japanese Patent Application Laid-Open No. 2004-139031.
The printer shown in FIG. 1 has a configuration in which a paper feeding unit 2 that stores paper P as a recording material is disposed at the bottom of the apparatus main body 1 and an image forming unit 3 is disposed above the paper feeding unit 2. The image forming unit 3 includes an image forming unit 8 including four image forming units 8Y, 8C, 8M, and 8BK as a plurality of image forming units including an image carrier, and a plurality of rollers 4, 5, 6 and An intermediate transfer unit 7 having an intermediate transfer belt 7a as an intermediate transfer member constituted by a flexible endless belt wound around these rollers 4, 5 and 6, and optical writing on each of the image carriers. An optical writing unit 15 as an optical writing unit to perform and a fixing device 19 for fixing the toner image on the paper P are provided.
The image forming units 8Y, 8C, 8M, 8BK and the intermediate transfer unit 7 are configured to be detachable from the apparatus main body 1. Between the sheet feeding unit 2 and the fixing device 19, a conveyance path R for conveying the sheet P on which an image is formed by the image forming unit 3 is formed. The roller 6 constitutes a secondary transfer device which will be described later, and is disposed facing the conveyance path R indicated by a one-dot chain line. An end portion R1 of the transport path R is opened to face a paper discharge tray 22 as a stacking portion constituting the paper discharge portion 20 formed on the upper portion of the apparatus main body 1. The image forming units 8Y, 8C, 8M, and 8BK are also called process cartridge units (PCU) 8Y, 8C, 8M, and 8BK.

  The space between the roller 4 and the roller 5 of the intermediate transfer belt 7a corresponds to the lower side belt running side of the belt 7a. In the intermediate transfer belt 7 a, a secondary transfer roller 16 serving as a secondary transfer device is disposed at a portion facing the roller 6 so as to face the conveyance path R, and a belt for cleaning the belt surface at a portion facing the roller 4. A cleaning device 17 is provided.

  The image forming unit 8 is disposed below the intermediate transfer belt 7a by being disposed so as to face the lower belt running side of the intermediate transfer belt 7a. In the present embodiment, the image forming units 8Y, 8C, 8M, and 8BK have basically the same configuration. In FIG. 1, only the configuration of the image forming unit 8BK is represented by the reference numerals of the constituent elements. Yes. Each of the image forming units 8Y, 8C, 8M, and 8BK includes a photosensitive drum 10 as an image carrier that is in contact with the intermediate transfer belt 7a. Around each photosensitive drum 10, a charging device 11, a developing device 12 as a developing means, and a cleaning device 13 are arranged. Transfer rollers 14 as transfer means for performing primary transfer are provided inside the intermediate transfer belt 7a at positions where the respective photosensitive drums 10 are in contact with the intermediate transfer belt 7a.

  The image forming units 8Y, 8C, 8M, and 8BK are different from each other only in the color of the toner as the developer stored in each developing device 12, and the other configurations are basically the same. The developing devices 12 of the image forming units 8Y, 8C, 8M, and 8BK contain yellow, cyan, magenta, and black toners, respectively. Each developing device 12 is configured to supply replenishment toner from toner bottles 32Y, 32C, 32M, and 32BK mounted and set on the upper portion of the apparatus body 1 when the toner is reduced.

  In FIG. 2, the reference numeral “Y” representing yellow is added to the end of the reference numeral of the developing device 12, and the detailed configuration of the developing device 12Y of the image forming unit 8Y will be described as a representative. Similarly, the developing device 12C shown in parentheses in the figure is arranged corresponding to the image forming unit 8C, the developing device 12M is arranged corresponding to the image forming unit 8M, and the developing device 12BK is arranged corresponding to the image forming unit 8BK, respectively. Represents things.

  The developing device 12Y includes a magnetic field generating means inside, and carries a two-component developer (hereinafter simply referred to as “developer”) including carrier and toner as magnetic particles on the surface, and the outer periphery of the photosensitive drum 10. A developing sleeve 25 as a developer carrying means / developer carrying body that conveys to a developing area facing the surface, and a doctor as a developer regulating member that regulates the layer thickness of the developer carried and carried on the developing sleeve 25 26, a developer containing portion 27 formed upstream of the doctor 26 in the developer carrying direction and containing the developer regulated by the doctor 26 without being conveyed to the developing region, and adjacent to the developer containing portion 27 A toner accommodating portion 28 that accommodates the formed toner and a toner conveying screw 29 for agitating and conveying the toner are provided.

  The optical writing unit 15 irradiates the surface of each photoconductor drum 10 with the light-modulated laser beam L, and forms a latent image for each color on the surface of the photoconductor. It is arranged below the part 8.

Next, the operation will be described.
In the printer shown in FIG. 1, when an image forming operation is started, the photosensitive drums 10 of the image forming units 8Y, 8C, 8M, and 8BK are rotated in a clockwise direction by a driving device (not shown). The surface of 10 is uniformly charged to a predetermined polarity by the charging device 11. Laser light L is irradiated from the optical writing unit 15 to the outer peripheral surface of each charged photosensitive drum 10, and an electrostatic latent image is formed on each surface. At this time, the image information to be exposed on each photosensitive drum 10 is single-color image information obtained by separating a desired full-color image into color information of yellow, cyan, magenta, and black. The electrostatic latent image formed in this manner is visualized as a toner image by the toner of each developing device 12 when passing between each photosensitive drum 10 and the developing device 12.

  Here, the detailed operation of the developing device 12Y will be described with reference to FIG. In the developing device 12Y, a developer layer is formed on the developing sleeve 25. Further, the toner is taken into the developer from the developer accommodating portion 27 by the movement of the developer layer conveyed by the rotation of the developing sleeve 25. The toner is taken in so that the developer is within a predetermined toner density range. The toner taken into the developer is charged by frictional charging with the carrier. The developer containing charged toner is supplied to the surface of the developing sleeve 25 having a magnetic pole inside and is carried by the magnetic force. The developer layer carried on the developing sleeve 25 is regulated in the direction of the arrow in FIG. 2 by the rotation of the developing sleeve 25, and the developer layer thickness is regulated by the doctor 26. It is transported to the opposite development area. In the development area, development based on the electrostatic latent image formed on the photosensitive drum 10 is performed. The developer layer remaining on the developing sleeve 25 is conveyed to the upstream portion of the developer accommodating portion 27 in the developer conveying direction as the developing sleeve 25 rotates.

  One of the plurality of rollers 4, 5 and 6 around which the intermediate transfer belt 7a is wound is driven to rotate counterclockwise by a driving device (not shown), whereby the intermediate transfer belt 7a is indicated by an arrow. The other rollers are driven to rotate by being driven in the counterclockwise direction shown. The yellow toner image formed by the image forming unit 8Y including the developing device 12Y having yellow toner as shown in FIG. A cyan toner image formed by the image forming units 8C, 8M and 8BK, a magenta toner image and a black toner image are successively transferred onto the transferred yellow toner image by the transfer roller 14, and the intermediate transfer belt 7a is thus transferred to the intermediate transfer belt 7a. A full-color toner image is carried on the surface.

  Residual toner adhering to the surface of each photosensitive drum 10 after the toner image is transferred is removed from the surface of the photosensitive drum 10 by each cleaning device 13, and then the surface is neutralized by a neutralizing device (not shown). The surface potential is initialized to prepare for the next image formation.

  On the other hand, the sheet P fed from the sheet feeding unit 2 is sent to the conveyance path R, and a pair of registration rollers disposed on the upstream side (the sheet feeding unit 2 side) of the conveyance path R with respect to the secondary transfer roller 16. The sheet feeding timing is taken by 18, and the roller 6 and the secondary transfer roller 16 are fed to the facing transfer portion. At this time, a transfer voltage having a polarity opposite to the toner charging polarity of the toner image on the surface of the intermediate transfer belt 7 a is applied to the secondary transfer roller 16, whereby the toner image on the surface of the intermediate transfer belt 7 a is collectively put on the paper P. Is transcribed. The sheet P to which the toner image has been transferred is conveyed to the fixing device 19, and when passing through the fixing device 19, heat and pressure are applied to melt and fix the toner image. The sheet P on which the toner image is fixed is conveyed to the discharge unit 21 disposed at the end R1 of the conveyance path R and is discharged to the discharge tray 22. After the toner image is transferred to the paper P, the toner remaining on the belt is removed from the belt cleaning device 17 by the intermediate transfer belt 7a.

  The tandem printer configured as described above is provided with four image forming units 8Y, 8M, 8C, and 8BK facing the intermediate transfer belt 7a, and sequentially transfers the toner images of the respective colors onto the intermediate transfer belt 7a. Therefore, for example, the image forming time is significantly shortened as compared with a type in which a single image forming unit has a four-color developing device and a toner image is transferred onto an intermediate transfer belt and then transferred onto a sheet. be able to. In addition, since the paper discharge tray 22 as a stacking unit is disposed on the upper part of the apparatus main body 1, the paper discharge tray 22 does not jump out from the apparatus main body 1, and the installation area and the occupied area are reduced. Have.

  The above description is an image forming operation when a full-color image is formed on the paper P. A single-color image can be formed using any one of the image forming units of the image forming unit 8, or two colors or A three-color image can also be formed. When monochrome printing is performed using the printer of this embodiment, an electrostatic latent image is formed only on the photosensitive drum 10 of the image forming unit 8BK, developed by the unit, transferred to the paper P, Fixing may be performed by the fixing device 19.

A characteristic configuration of the present embodiment will be described with reference to FIGS. 1 to 4.
In FIG. 3, in order to simplify the drawing, only the toner bottle 32BK containing black toner is placed and mounted on the bottle container 31 and only the toner transport device 50BK that transports black toner and the like. As shown in parentheses in the drawing, the toner transport devices 50Y, 50C, and 50M that transport the other toner bottles 32Y, 32C, and 32M and the corresponding toner and the like are shown. Is intentionally omitted. Further, FIG. 4 is enlarged for the sake of simplification of the drawing, so that there appears to be a gap at the connection portion between the toner bottle 32BK and the toner transport device 50BK, but of course, no toner scattering occurs. Needless to say, it is configured in a connected state.

  The characteristic configuration of the present embodiment is that toner bottles 32Y, 32C, 32M, and 32BK as toner storage means and toner supply containers for supplying toner to the developer storage unit 27 shown in FIG. , 32M, 32BK to toner transporting device 50Y as toner transporting means for transporting toner of each color through toner transporting path 64 (see FIG. 4) to developer accommodating portion 27 of each developing device 12Y, 12C, 12M, 12BK. , 50C, 50M, and 50BK, and the image forming units 8Y, 8C, 8M, and 8BK having the corresponding developing devices 12Y, 12C, 12M, and 12BK, and the toner bottles 32Y, 32C, 32M, and 32BK 1 is a printer configured to be detachable individually from each other, and each toner transport device 50Y, 50C, 50M. Before the initial drive of the toner transport devices 50Y, 50C, 50M, and 50BK in which no toner is present in 50BK and the toner transport path 64 (for example, in the present embodiment, it indicates before the printer is shipped and first driven by the user or the like). The carrier 36 shown in FIG. 4 will be described later in the toner transport path 64 to such an extent that toner does not flow from the toner bottles 32Y, 32C, 32M, 32BK to the developer accommodating portions 27 of the developing devices 12Y, 12C, 12M, 12BK. The developing device 12Y, 12C retains the carrier 36 that has been retained in advance in a predetermined portion and retained in advance during initial driving (for example, in the present embodiment, when the printer is first driven to the user). , 12M, 12BK to the developer container 27.

Each of the toner bottles 32Y, 32C, 32M, and 32BK is different only in the color of the contained toner, and the other configurations are the same. Therefore, the configuration around the toner bottle 32BK will be described as a representative. The basic configuration of the toner bottle 32BK is the same as that shown in FIGS. 3 to 7 of Japanese Patent Laid-Open No. 2004-139031 and described in the paragraph “0021” and the detachment operation / operation (however, , Component names are slightly different). As shown in FIGS. 3 and 4, the toner bottle 32 BK includes a bottle main body 33 that stores black toner 39, and a resin cap that is provided at the tip of the bottle main body 33 and is configured integrally with the handle 35. 34 and a shutter 37 that is provided on the cap 34 side and is openable and closable to discharge black toner 39, and a gear (not shown) that is provided on the cap 34 side and rotates integrally with the bottle body 33. Yes. On the inner wall surface of the bottle body 33, a spiral toner guide groove 38 for guiding the toner 39 stored therein to the cap 34 side is formed.
The toner bottle 32BK shown in FIG. 4 shows a state in which the toner bottle 32BK is merely placed on the bottle container 31 (not shown in FIG. 4) and the shutter 37 is closed.

Since the toner conveying devices 50Y, 50C, 50M, and 50BK are different only in the color of the toner to be conveyed and other configurations are the same, the configuration around the toner conveying device 50BK will be described as a representative. The basic configuration of the toner conveying device 50BK is the same as that described in paragraphs “0022” to “0024” shown in FIGS. 5 to 8 and FIG. (However, the names of the constituent elements are slightly different), and are arranged so as to carry using the weight of the toner.
The toner conveying device 50BK, along with the other toner conveying devices 50Y, 50C, and 50M, is provided on the apparatus main body 1 on the side of the intermediate transfer unit 7 in FIG. 1, and is disclosed in JP-A-2004-139031. It has the advantages described in paragraph “0022”.

  As shown in FIGS. 3 and 4, the toner conveying device 50BK is accommodated in a conveying pipe 63 as a toner conveying tube forming a toner conveying path 64 and one end of the conveying pipe 63 being inscribed in the conveying pipe 63, and its movement Rotating member 60a and conveying coil 60b that constitute a toner conveying member that moves toner downstream in the conveying direction by means of, rotation motor 60a and conveying motor 60b as driving means for driving toner bottle 32BK, and rotation It is mainly composed of driving force transmitting means for transmitting the rotational driving force of the driving motor 55 to the conveying coil 60b via the member 60a.

  The transport pipe 63 is formed of a resin mold. The transfer coil 60b is formed of an appropriate resin, and the other end is wound and fixed to one end of the rotating member 60a. The gap (maximum and minimum dimensions) between the inner peripheral wall of the transfer pipe 63 and the outer periphery of the transfer coil 60b is set to about 0.1 to 0.2 mm in the embodiment. In FIG. 4, the other end portion (the lower end side in the drawing) of the transfer coil 60b is partially omitted.

  With such a configuration of the transport pipe 63 and the transport coil 60b, the same advantages and effects as those described in paragraph “0031” of the above Japanese Patent Application Laid-Open No. 2004-139031 are achieved. That is, it is possible to prevent toner from accumulating in the transport pipe 63 by installing the transport coil 60b in the transport pipe 63 so as to be substantially inscribed, and applying a force to the toner to move in the transport direction. it can. Therefore, it is possible to prevent problems caused by the toner accumulated in the transport pipe 63 flowing into the developing device 12BK of the image forming unit 8BK at a time due to some impact or the like. Further, since the coil shape of the transfer coil 60b is small in bending stress, the transfer coil 60b can rotate even if the transfer pipe 63 is bent. Therefore, since it is not necessary to make the transport coil 60b linear, the degree of freedom in design layout can be increased, and the overall size of the developing device can be reduced.

  However, if the gap between the inner peripheral wall of the transfer pipe 63 and the outer periphery of the transfer coil 60b is set to about 0.1 to 0.2 mm in the embodiment, the user or the like first starts using the printer. During the initial driving, the drive motor 55 is continuously driven, and the toner discharged from the toner bottle 32BK mounted and set in the bottle container 31 is transported at a time due to the drop of toner due to the action of gravity. It has been confirmed by various experiments that it flows into the developing device 12BK through the pipe 63.

  Therefore, before the initial driving of the toner conveying device 50BK in which no toner is present in the toner conveying device 50BK, the toner is transferred to the carrier 36 shown in FIG. 4 to such an extent that the toner does not flow from the toner bottle 32BK into the developer containing portion 27 of the developing device 12BK. It is a necessary condition to stay in advance in a predetermined part of the transport path 64 which will be described later.

3 and 4, reference numeral 56 denotes a driving gear constituting the driving force transmission means, reference numeral 57 denotes a shaft that is substantially integral with the driving gear 56, and reference numeral 62 denotes black that is discharged from the toner bottle 32BK. The storage stack peripheral walls forming the storage stack 61 for temporarily storing the toner are respectively shown. Both ends of the shaft 57 are rotatably supported on both side walls of the housing stack peripheral wall 62 through bearing portions 51a and 51b fitted with rolling bearings. A flexible sheet is fixed to a central portion of the shaft 57 over a predetermined width, and has a function of stirring the toner in the storage stack 61 by rotating. A gear 58 is fixed to a shaft 57 near the drive gear 56. On the other hand, the other end of the rotating member 60 a is rotatably supported on one side wall of the accommodation stack peripheral wall 62 via the bearing portion 52. A gear 59 that meshes with the gear 58 is fixed to the tip of the other end of the rotating member 60a.
As described above, the driving force transmitting means for transmitting the rotational driving force of the driving motor 55 to the conveying coil 60b via the rotating member 60a is composed of the motor gear, the driving gear 56, the shaft 57, the gear 58, the gear 59, etc. (not shown). Has been.

  The drive motor 55 is composed of, for example, a brushless DC motor, and a motor gear (not shown) is fixed to the output shaft thereof. The motor gear (not shown) is arranged to mesh with the gear (not shown) of the toner bottle 32BK and always mesh with the drive gear 56 when the toner bottle 32BK is mounted and set in the bottle container 31. As shown in FIG. 2, the drive motor 55 is driven and controlled in response to a command signal from the CPU of the control unit 54 as a control means having a microcomputer including a CPU, RAM, ROM, timer, and the like. It is like that.

  The ROM stores in advance an operation program and related data for controlling the drive motor 55 during initial driving and normal driving, and this operation program is appropriately called by the CPU. The RAM has a function of temporarily storing calculation results of the CPU, a function of storing data signals and ON / OFF signals set and input from various keys and various sensors on an operation panel (not shown) as needed. ing. The ROM may store in advance an operation program and related data of the entire printer shown in FIG.

With reference to FIGS. 2 to 3, the operation of the toner transport device 50BK during a normal operation other than the initial drive will be described.
When the drive motor 55 is rotationally driven by a command from the CPU of the control unit 54, the bottle body 33 that rotates integrally with the gear (not shown) of the toner bottle 32BK rotates. When the density detection sensor 30 of the developing device 12BK shown in FIG. 2 detects toner shortage in the toner storage unit 28, the drive motor 55 is rotationally driven by a command signal relating to toner supply from the control unit 54. When the bottle main body 33 rotates, the toner 39 inside the bottle main body 33 is conveyed from the back side of the bottle main body 33 toward the cap 34 at the front end by the action of the toner guide groove 38. Next, the toner 39 in the bottle main body 33 falls from the outlet of the cap 34 to the toner receiving portion 53 of the toner conveying device 50BK.

  The toner receiver 53 is connected to and connected to the storage stack 61 and the transport pipe 63. When the drive motor 55 is driven to rotate, the bottle body 33 rotates and the transport coil 60b rotates. Due to the rotation of the conveying coil 60b, the toner dropped on the toner receiving portion 53 is conveyed through the conveying pipe 63 and is replenished to a toner replenishing port (not shown) of the toner accommodating portion 28 of the developing device 12BK. In this way, the toner density in the developing device 12BK is adjusted.

  Paying attention to the above-described unique configuration of the toner conveying device 50BK, before the initial driving of the toner conveying device 50BK in which no toner is present in the toner conveying device 50BK, that is, in this embodiment, the printer is shipped and driven first by the user or the like. Before the toner cartridge 32BK, the carrier coil 60b in the accommodation stack 61 is used as a predetermined portion in the toner conveyance path 64 in which the carrier 36 is preliminarily retained so that the toner does not flow into the developer accommodating portion 27 of the developing device 12BK. Is in the vicinity of the upstream side in which the transport pipe 63 is accommodated, that is, in the vicinity of the transport coil 60 b in which the upstream end of the transport pipe 63 is inserted and connected to the accommodation stack 61. Here, “to the extent that toner does not flow” means that there is no slight gap that allows toner to flow in the toner conveyance path 64.

  That is, in the present embodiment, the upstream end of the transport pipe 63 is preliminarily retained by administering a predetermined amount of the carrier 36 in the vicinity of the transport coil 60b inserted and connected to the containing stack 61, as described above. Even if the gap between the inner peripheral wall of the transfer pipe 63 and the outer periphery of the transfer coil 60b is set to about 0.1 to 0.2 mm in the embodiment, the carrier 36 (for example, the range of the particle diameter is in the embodiment). 0.022 to 0.088 mm, the average particle diameter in the granularity distribution is 0.036 mm = 36 μm), or all of the particles are not perfectly spherical but have irregular shapes. By acting so as to close the gap, even a toner having a particle size much smaller than that of the carrier 36 (for example, in the embodiment, the particle size range is 6 to 12.5 μm) falls or passes through. Therefore, the toner does not flow from the toner bottle 32BK into the developer accommodating portion 27 of the developing device 12BK.

  In order to prevent the rotation of the rotating member 60a and the conveying coil 60b during the movement of shipping the toner conveying device 50BK as a printer or as a service / supplement after the carrier 36 stays in the above-described region, for example, the drive gear 56 or A measure for preventing the drive motor 55 from rotating, for example, rotation of the drive gear 56 or the drive motor 55 may be prevented by a stopper member or the like, or rotation of the drive gear 56 or the like is prevented by attaching / fixing an adhesive tape. May be.

With reference to FIGS. 2 to 3, the operation of the toner transport device 50BK at the time of initial driving will be described focusing on differences from the above-described normal operation.
The first difference is that the initial toner filling control for filling toner into the toner transport path 64 by the toner transport device 50BK in accordance with a command from the CPU of the control unit 54 is performed from the toner bottle 32BK to the developer storage of the developing device 12BK. This is because the driving motor 55 is controlled via a motor driving circuit (not shown) so as to perform the intermittent driving in which the toner does not flow, instead of the continuous driving in which the toner flows into the unit 27. In addition, the carrier 36 staying in advance at the time of initial driving is to be conveyed to the developer accommodating portion 27 of the developing device 12BK.

  The second difference is that the number of intermittent driving operations in the initial toner filling control is set in a range in which toner is not replenished to the developer accommodating portion 27 of the developing device 12BK, and related data relating thereto is stored in the ROM in advance. It is in a memorized point.

  The third difference is that the staying amount of the carrier 36 staying in advance is set within a range that does not hinder the developing operation by the developing device 12BK.

  In the embodiment described above, the carrier 36 is retained in the above-described portion. However, instead of the carrier 36, a developer obtained by stirring and mixing the carrier and the toner may be retained in advance. In this case, a particle group in which the toner is attached is formed around the carrier, which is more advantageous for filling the gap in the above-mentioned portion than in the case of the carrier alone.

Example 1 is shown in FIG.
In the first exemplary embodiment, toner bottles 32Y, 32C, 32M, and 32BK that are detachably attached to the apparatus main body 1 and developing devices 12Y, 12C, 12M, and 12BK are provided, and the toner conveying devices 50Y, 50C, 50M, and 50BK are included in the apparatus main body. 1, the same basic configuration as that of the printer shown in FIG. 1 is used, and an upstream end of the conveying pipe 63 is used as shown in FIG. The experiment was performed by retaining the carrier 36 or the developer in the vicinity of the transfer coil 60 b through which the part is inserted and connected to the containing stack 61. Hereinafter, the toner bottle 32BK, the developing device 12BK, and the toner conveying device 50BK will be described as a representative.

  The graph of FIG. 5 shows that immediately after the toner bottle 32BK is shaken several times, the toner bottle 32BK is mounted and set in the bottle container 31 and the carrier 36 or the developer is retained in the above-described portion, and then the toner transport device 50BK is installed. It shows the result of observing and experimenting whether toner flows from the toner conveyance path 64 without driving and measuring the amount of toner flow. In the graph of FIG. 5, the horizontal axis represents the weight (g) as the retention amount of the carrier 36 or the developer, and the vertical axis represents the weight (g) as the toner discharge amount, which is the amount of toner flowing in. Yes.

  As the carrier 36, a ferrite-based material having a particle diameter range of 22 to 88 μm and an average particle diameter distribution of 36 μm was used. As the developer, the same one as the carrier 36, a toner material of a polyester resin, and a toner having a particle diameter range of 6 to 12.5 μm was stirred and mixed.

From the graph in the figure, it was found that the retention amount of the carrier 36 or the developer is desirably 4 g or more in which the toner discharge amount, that is, the toner flow is hardly observed.
As described above, the retention amount of the carrier 36 or the developer may be 4 g or more with almost no toner flowing in, but the upper limit is set within a range that does not hinder the developing operation by the developing device 12BK. do it. Thereby, the retention amount of the carrier 36 or the developer can be saved and the input operation can be improved.

A second embodiment is shown in FIGS. 6 and 7B. Hereinafter, Examples 2 and 3 are examples in which the carrier 36 is used as the particles to be retained.
In the second embodiment, in the printer of the toner transport device 50BK that retains 4 g or more as the retention amount of the carrier 36 (or developer) in the first embodiment, the toner is transported into the transport pipe 64 of the toner transport path 64 by the toner transport device 50BK. The drive motor 55 is controlled by the CPU of the control unit 57 so that the initial toner filling control for filling is performed by intermittent drive in which toner does not flow from the toner bottle 32BK to the developer containing unit 27 of the developing device 12BK. I went there.

  The graph of FIG. 6 shows the cumulative toner replenishment amount depending on the driving method of the driving motor 55 in the toner transport device 50BK. In the graph of FIG. 6, the horizontal axis represents the time (s: seconds) when the drive motor 55 is driven as the replenishment time, and the vertical axis represents the total toner replenishment amount (g).

  As can be seen from the graph of FIG. 6, the intermittent drive of the drive motor 55 as shown by the solid line in FIG. 6 and as shown in FIG. 7B is shown by the broken line in FIG. In the continuous driving of the drive motor 55 as shown, a sudden change in the toner replenishment amount occurs. In FIGS. 7A and 7B, the horizontal axis represents time (s: second). Therefore, it has been found that it is desirable to control by intermittent driving in order to prevent the toner from flowing in at the time of initial driving.

FIG. 8 shows a third embodiment.
In the third embodiment, the drive motor 55 is controlled by the CPU of the controller 57 within the range in which the toner is not replenished to the developer container 27 of the developing device 12BK. I went there.

  The graph of FIG. 8 shows the replenishment amount of only the toner when the transport pipe 63 is initially filled due to the difference in the retention amount of the carrier 36 (or developer) retained in the above-mentioned part in the toner transport device 50BK. is there. In the graph of the figure, the horizontal axis represents the number of times of replenishment, which is the number of intermittent drives, and the vertical axis represents the amount of toner supply (g). The drive motor 55 is intermittently driven for 1 s (seconds) and turned off for 4 s (seconds) per replenishment.

  Referring to the graph of FIG. 8, in order to replenish the toner from the toner bottle 32BK to the developer container 27 of the developing device 12BK at the time of initial filling, it is necessary to perform intermittent driving by the driving motor 55 several times. I understand. Accordingly, the filling control performed until the toner is filled in the toner conveying device 50BK is required to be intermittently controlled so that the toner is not replenished to the developer storage portion 27 of the developing device 12BK. It can be said that it is desirable to set the number of missing drives to around 10.

1 is a front view of an entire printer showing an embodiment of the present invention. FIG. 2 is a front view around a partial image forming unit provided in the printer of FIG. 1. FIG. 2 is a perspective view around a toner bottle, a toner conveying device, and a developing device arranged in the printer of FIG. 1. FIG. 3 is a cross-sectional view illustrating a configuration of a main part of a toner bottle and a toner conveyance device. 6 is a graph illustrating Example 1 and is a graph illustrating a relationship between a retention amount of a carrier or a developer and a toner discharge amount that is a flow of toner. 6 is a graph illustrating Example 2 and is a graph illustrating a relationship between a driving method of a driving motor and an integrated toner supply amount in the toner conveying device. FIG. 7 is a diagram illustrating a driving method of the drive motor in FIG. 6, where (a) illustrates an example in the case of continuous driving, and (b) illustrates an example in the case of intermittent driving. 6 is a graph showing the relationship between the number of times of replenishment related to the number of times the drive motor is driven and the amount of replenishment of toner only at the time of initial filling when the carrier retention amount is used as a parameter.

Explanation of symbols

1 Device body (image forming device body)
10 Photosensitive drum (image carrier)
12Y, 12C, 12M, 12BK Developing device (developing means)
25 Development sleeve (agent carrying means)
27 Developer container 32Y, 32C, 32M, 32BK Toner bottle (toner container)
36 Carrier 50Y, 50C, 50M, 50BK Toner conveying device (toner conveying means)
54 Control unit (control means)
55 Drive motor (drive means)
60a Rotating member 60b Conveying coil (toner conveying member)
63 Conveying pipe (toner conveying pipe)
64 Toner transport path

Claims (7)

An image carrier, a developing means including a developer carrying means and a developer containing section for containing a developer, a toner containing means for supplying toner to the developer containing section, and the developer containing section from the toner containing means In the image forming apparatus, the image forming apparatus further includes a toner conveying unit configured to convey toner via a toner conveying path, and the developing unit and the toner containing unit are individually detachable from the main body of the image forming apparatus. ,
The toner conveying means is a toner conveying tube that forms the toner conveying path, and one end of the toner conveying tube is accommodated inside the toner conveying tube, and is conveyed as a toner conveying member that moves the toner downstream in the conveying direction by its movement. The apparatus includes a coil, a rotating member that fixes the other end of the conveying coil, and a driving unit that rotationally drives the rotating member, so that toner is conveyed using its own weight. ,
Before the initial driving of the toner conveying means in which no toner is present in the toner conveying means, the carrier or the developer is contained in one end of the conveying coil so that the toner does not flow from the toner containing means to the developer containing portion. In the vicinity of the upstream side in the toner transport pipe, and the carrier or developer retained in advance is transported to the developer accommodating portion during the initial driving , and the toner transport means The initial toner filling control for filling the toner in the toner transport path is performed not by continuous driving in which toner flows from the toner containing means to the developer containing portion but by intermittent driving in which toner does not flow. An image forming apparatus. The image forming apparatus according to claim 1.
The image forming apparatus, wherein the image forming apparatus is shipped before the initial driving. The image forming apparatus according to claim 1 or 2,
2. The image forming apparatus according to claim 1, wherein the number of times of intermittent driving in the initial toner filling control is set in a range in which toner is not replenished to the developer container . The image forming apparatus according to any one of claims 1 to 3,
An image forming apparatus characterized in that a staying amount of a carrier or developer staying in advance is set in a range that does not hinder a developing operation by the developing unit. An image forming method using the image forming apparatus according to claim 1 . A toner containing means configured to be detachable from the image forming apparatus main body for replenishing toner to the developer containing portion of the developing means provided with a developer containing means and a developer containing portion for containing the developer; A toner conveying device having toner conveying means disposed in the image forming apparatus main body and configured to convey toner from the toner accommodating means to the developer accommodating portion via a toner conveying path;
5. A toner conveying device, wherein the toner conveying device is used in an image forming apparatus according to claim 1 . A toner containing means configured to be detachable from the image forming apparatus main body for replenishing toner to the developer containing portion of the developing means provided with a developer containing means and a developer containing portion for containing the developer; In a toner conveying method using a toner conveying device disposed in the image forming apparatus main body and having toner conveying means for conveying toner from the toner accommodating means to the developer accommodating portion via a toner conveying path,
6. A toner conveying method, wherein the toner conveying method is used in an image forming method according to claim 5 .

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