JP2007272014A - Rotary developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make the storage amount of developer in a certain color to be frequently used larger than that of developer in other colors while using components in common, to facilitate manufacture. <P>SOLUTION: Regarding the rotary developing device 21 used for a color printer 1 for forming a color image, the device 21 includes a plurality of developing units 26 and a rotating frame 211. The developer corresponding to each color is stored in the developing unit 26, and two or more developing units 26 store the developer in the same color. The rotating frame 211 is a freely rotatable member that supports the plurality of developing units 26. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a rotary developing apparatus and an image forming apparatus, and more particularly to an image forming apparatus capable of forming a full-color image and a rotary developing apparatus used in the image forming apparatus.

  An image forming apparatus for forming a color image includes a plurality of developing units in which developers of different colors are accommodated. In order to reduce the size of an image forming apparatus, there is an image forming apparatus including a rotary developing device in which a plurality of developing devices are attached to a rotatable frame (see Patent Document 1).

  When forming a color image, the image forming apparatus equipped with the rotary developing device rotates the frame so that the developing devices are sequentially arranged at predetermined developing positions, and images of the respective colors are transferred onto the intermediate transfer material. The images are finally formed by melting and fixing them.

Further, in an image forming apparatus, a developer of a specific color such as black is often used as compared with other colors. However, since image forming apparatuses provided with a rotary developing device are generally provided with developing devices of the same size, only the developer of that specific color may be consumed and lost. Therefore, it is necessary to replenish a specific color developer frequently. In order to solve such a problem, there is an image forming apparatus in which only a developing device for storing a developer of a frequently used color is enlarged (see Patent Document 2).
JP 2005-24575 A JP 2005-257875 A

  However, in the image forming apparatus described in Patent Document 2, since only a developing device that stores a developer of a specific color is a large developing device, it is difficult to make components common and difficult to manufacture.

  SUMMARY OF THE INVENTION An object of the present invention is to make it easy to manufacture because the storage amount of a developer of a frequently used color is larger than the storage amount of another color developer, and the parts can be made common.

  A rotary developing device according to a first aspect is a rotary developing device used in an image forming apparatus capable of forming a color image, and includes a plurality of container main bodies and a frame member. Each of the plurality of container main bodies contains a developer corresponding to each color, and two or more of them contain the same color developer. The frame member is a member that supports a plurality of container bodies and is rotatable.

  In this rotary developing device, when the container main body that stores the developer for the first color is positioned at the development position, the developer for the first color is supplied to the image carrier. Thereafter, the frame rotates and the container main body for storing the developer for the second color is positioned at the development position, and the developer is supplied to the image carrier. In this way, the container main body is sequentially positioned at the developing position, and the developer of each color is supplied to the image carrier to finally form a full color image.

  Here, since two or more container bodies store the same color developer, the storage amount of frequently used color developer should be larger than the storage amount of other color developers. Can do. Moreover, since all the container main bodies are the same in the configuration of the container main body, it is easy to manufacture because the parts can be shared.

  A rotary developing device according to a second aspect is the rotary developing device according to the first aspect, wherein the container main bodies containing the developer of the same color are arranged so as not to be adjacent to each other.

  A rotary developing apparatus according to a third aspect is the rotary developing apparatus according to the first or second aspect, wherein the frame member supports five or more container bodies.

  Here, the number of container main bodies that store the developer of a color that is frequently used can be three, or a development system of four or more colors can be used.

  According to a fourth aspect of the present invention, there is provided the rotary developing device according to any one of the first to third aspects, wherein at least two of the plurality of container main bodies store a black developer.

  This is particularly effective when black is used frequently.

  According to a fifth aspect of the present invention, there is provided an image forming apparatus comprising: the rotary developing device according to any one of the first to fourth aspects; and an image carrier disposed adjacent to the rotary developing device and supplied with a developer from the rotary developing device. ing.

  An image forming apparatus according to a sixth aspect is the image forming apparatus according to the fifth aspect, wherein continuous printing is performed using the developer of two or more container bodies containing the same color developer. Recognizing means for recognizing, and rotating position control means for controlling the rotational position of the frame so as to supply the developer from a different container main body for each printing operation when the recognizing means recognizes continuous printing. A control unit is further provided.

  Here, when the fixing unit of the image forming apparatus and the rotary developing device are arranged at positions close to each other, and when continuous printing is performed with a single color developer as in monochrome continuous printing, each container body is the same. Will be in position for a long time. In such a case, the container body closest to the fixing unit may be affected by heat (development of developer due to heat, etc.).

  Therefore, in this rotary developing device, for example, when black is continuously printed, the black developer is supplied from a different container body for each image forming process.

  Here, for example, even when black is continuously printed, one container body is not positioned at a position close to the fixing unit for a long time. Therefore, it is possible to prevent one container body from being concentrated and affected by heat.

  According to the present invention, it is possible to store a larger amount of developer of a color that is used more frequently than other colors of developer, and to make the container main body in common, which facilitates manufacture.

[First embodiment]
1. Configuration FIG. 1 shows a color printer 1 as a color image forming apparatus according to an embodiment of the present invention. FIG. 1 is a schematic diagram for showing the arrangement of each component, and details of each part are omitted.

  The color printer 1 is connected to a computer (not shown) or the like, and is a device that can print a color image on paper based on image information sent from an external computer or the like. The color printer 1 includes an image forming unit 2, a fixing unit 3, a paper storage unit 4, a paper transport unit 5, a discharge unit 6, and a control unit 7.

  The image forming unit 2 forms an image based on image data transmitted from a computer. The image forming unit 2 includes a rotary developing device 21, a photosensitive drum 22, a laser unit 23, an intermediate transfer belt 24, and a secondary. And a transfer roller 25.

  The rotary developing device 21 includes a rotary frame 211 and six developing devices 26 supported by the rotary frame 211. The rotation frame 211 is a member that is rotatable around an axis parallel to the rotation axis of the photosensitive drum 22, and is rotated by a drive mechanism including a motor and a gear (not shown). The rotating frame 211 has six sections divided into six equal parts in the circumferential direction by a partition frame extending radially from the center of the rotation axis. As shown in FIG. 3, yellow, black, The developing devices 26 corresponding to magenta, black, cyan, and black are arranged in this order. Here, FIG. 3 is a schematic diagram showing the arrangement of the developing device 26 of the rotary developing device 21. In the rotary developing device 21, when black is continuously printed, black toner is supplied from a different developing device 26 for each image forming process.

  The developing device 26 is a portion for supplying toner to the photosensitive drum 22. Each developing device 26 has substantially the same configuration, and one sectional view of the developing device 26 is shown in FIG. As shown in FIG. 2, the developing device 26 includes a developing roller 261, a toner container 262, a toner supply roller 263, and a blade member 264.

  The developing roller 261 is a member for supplying toner to the photosensitive drum 22 and has a metal cylindrical portion and an elastic portion provided around the cylindrical portion. The developing roller 261 is disposed at a distance from the photosensitive drum 22.

  The toner storage container 262 is a portion for storing toner therein, and has an opening 26a and a toner stirring member 265 disposed inside. A developing roller 261 is rotatably supported in the opening 26 a of the toner container 262. The opening 26a is opened along the axis of the developing roller 261 so that a part of the developing roller 261 is exposed to the photosensitive drum 22 side.

  The toner supply roller 263 is a cylindrical member that is disposed inside the toner container 262 so as to be in contact with the developing roller 261 and has a surface formed of a sponge material.

  The blade member 264 is a member for creating a thin uniform toner layer by rubbing the toner on the surface of the developing roller 261 and regulating the amount of toner on the surface of the developing roller 261. It is fixed to the upper side of the part 26 a and has advanced to the vicinity of the developing roller 261. The blade member 264 is formed of a plate member made of an elastically deformable metal.

  The photosensitive drum 22 has an electrostatic latent image formed on the surface thereof, and is rotatably provided at the center of the apparatus. The rotation axis of the photosensitive drum 22 extends in the lateral direction as viewed from the left side of FIG. It is provided so as to extend perpendicular to the paper surface of FIG. In addition, the photosensitive drum 22 is disposed at a distance from the developing roller 261. Further, a drum cleaning device for cleaning toner and adhering matter remaining on the surface of the photosensitive drum 22 is provided on the side of the photosensitive drum 22.

  The laser unit 23 scans and exposes the photosensitive drum 22 based on image information sent from an external computer or the like. The internal configuration of the laser unit 23 is the same as the conventional configuration, and includes a laser light source, a polygon mirror, a polygon mirror driving motor, and the like. In addition, a reflection mirror is provided in front of the laser beam path of the laser unit 23. Accordingly, the laser light emitted from the laser unit 23 is bent by the reflecting mirror, passes through the upper left side of the rotary developing device in FIG. 1, and is irradiated onto the surface of the photosensitive drum 22.

  The intermediate transfer belt 24 sequentially transfers the toner images of each color formed on the photosensitive drum 22, and is hung between the driving roller and a driven roller urged away from the driving roller by a spring. Has been passed. Further, the portion of the transfer belt 24 facing the photosensitive drum 22 is configured to abut on the photosensitive drum by a pair of primary transfer rollers 24a and 24b.

  The secondary transfer roller 25 is for transferring the image transferred to the intermediate transfer belt 24 onto the conveyed paper, and is disposed below the drive roller so as to face the drive roller.

  The fixing unit 3 is for fusing and fixing the toner transferred onto the paper, and is disposed below the rotary developing device 21 and on the right side of FIG. The fixing unit 3 includes a heating roller 41 with a built-in heater and a pressure roller 42 that is in pressure contact with the heating roller 41.

  The paper storage unit 4 is disposed on the lower side of the color printer 1, and includes a paper feed cassette 41 in which paper is stored, a roller for supplying the paper to the paper transport unit 5, and the like.

  The paper transport unit 5 is a part for transporting the paper in the paper feed cassette 41 to the image forming unit 2 and the fixing unit 3.

  The discharge unit 6 is a part that discharges the sheet on which the image is fixed, and is disposed on the color printer 1.

  As shown in FIG. 4, the control unit 7 functions as a recognition unit 71 and a rotational position control unit 72 when the CPU executes a program. Here, FIG. 4 shows a block diagram of the control unit 7.

  The recognizing unit 71 is a unit for recognizing that the black print command is continuously issued, and recognizes that the black print command is continuously executed by an external computer or the like.

  When the recognizing unit 71 recognizes that the black print command has been continuously issued, the rotation position control unit 72 supplies the rotation frame so that the toner is supplied to the photosensitive drum 22 from the different developer 26 for each printing operation. The rotational position of 211 is controlled.

2. Operation Next, an image forming operation will be described.

  When image data of an image to be printed is transmitted from the computer, the surface of the photosensitive drum 22 is charged, and laser light is irradiated from the laser unit 23 to the surface of the photosensitive drum 22 based on the image data. Then, each color toner is supplied from the rotary developing device 21 to the surface of the photosensitive drum 22, and a full-color toner image is formed on the photosensitive drum 21.

  The operation when the toner is supplied from the developing device 26 to the photosensitive drum 22 will be specifically described with reference to FIG. When a full-color image is printed, the rotating frame 211 is rotated so that the developing device A1 that stores yellow toner is opposed to the photosensitive drum 22 first. When yellow toner is supplied to the photosensitive drum 22 by the developing roller 261, the rotating frame 211 is then rotated so that the developing device A3 in which magenta toner is stored is opposed to the photosensitive drum 22. When magenta toner is supplied from the developing roller 261 to the photosensitive drum 22, the rotating frame 211 is rotated so that the developing unit A 5 that stores cyan toner is opposed to the photosensitive drum 22. After the cyan toner is supplied to the photosensitive drum 22, the developing unit A <b> 6 that stores the black toner is opposed to the photosensitive drum 22 to supply the black toner to the photosensitive drum 22. At this time, if the black toner is already consumed in the developing device A6, the black toner is supplied with the developing device A2 facing the photosensitive drum 22. Here, when the black toner in both the developing devices A6 and A2 has already been consumed, the black toner is supplied with the developing device A4 facing the photosensitive drum 22. As described above, since the developing units 26 that store the frequently used black toner are arranged in three places, the number of times of toner replenishment can be reduced.

  A case where a plurality of image forming processing operations are successively executed for a black image will be specifically described. When the image forming operation is continued below a certain number (for example, 10), the toner is supplied from the same developing device 26 to the photosensitive drum 22, but when the image forming operation is a certain number or more, the developing device that supplies the toner to the photosensitive drum 22 The image forming operation is performed while changing 26. Specifically, when a black image is first formed, black toner stored in the developing device A4 is supplied to the photosensitive drum 22. When a black image is printed in the second image formation processing operation after the first image formation processing operation, black toner stored in the developing device A6 is supplied to the photosensitive drum 22. When the black image is printed for the third time after the second printing, the black toner stored in the developing device A2 is supplied to the photosensitive drum 22. Here, even when a black image is printed a plurality of times, since the rotating frame 211 rotates and changes the position of each developing unit 26, the effect of the specific developing unit 26 approaching the fixing unit for a long time. It becomes difficult to receive. Further, in both the case of printing a full-color image and the case of printing only black, the toner in the developing device 26 is easily stirred because it is well rotated by the rotating frame 211, and is caused by the toner not being stirred. Toner deterioration can be prevented.

  At this time, the sheet is conveyed from the sheet storage unit 4 to the lower side of the intermediate transfer belt 24, and the full-color toner image formed on the photosensitive drum 22 is transferred to the sheet by the intermediate transfer belt 24. The sheet on which the image has been transferred is conveyed to the fixing unit 3 by the sheet conveying unit 5, and the image is fixed on the sheet. The sheet on which the image is fixed is discharged from the discharge unit 6.

[Second Embodiment]
1. Configuration As shown in FIG. 5, the color printer 110 includes an image forming unit 120, a fixing unit 130, a paper storage unit 140, a paper transport unit 150, and a discharge unit 160. Here, since the configuration of the image forming unit 120 other than the rotary developing device 121 is the same as that of the first embodiment, description thereof is omitted.

  The rotary developing device 121 includes a rotary frame 122 and five developing units 126 supported by the rotary frame 122. The rotating frame 122 is a member that is rotatable around an axis parallel to the rotating shaft of the photosensitive drum 123, and is rotated by a driving mechanism including a motor and a gear (not shown). Further, the rotating frame 122 has five sections that are divided into five equal parts in the circumferential direction by a partition frame that extends radially from the center of the rotating shaft. As shown in FIG. Developers 126 corresponding to the order of magenta, black, and cyan are arranged.

2. Operation When image data of an image to be printed is transmitted from the computer, the surface of the photosensitive drum 123 is charged, and laser light is emitted from the laser unit 124 to the surface of the photosensitive drum 123 based on the image data. Then, each color toner is supplied from the rotary developing device 121 to the surface of the photosensitive drum 123, and a full-color toner image is formed on the photosensitive drum 123.

  The operation when supplying toner from the developing device 126 to the photosensitive drum 123 will be specifically described with reference to FIG. When a full-color image is printed, the rotating frame 122 rotates and the developing device B1 that stores yellow toner is opposed to the photosensitive drum 123 first. When yellow toner is supplied to the photosensitive drum 123 by the developing roller, the rotating frame 122 is then rotated so that the developing unit B3 in which magenta toner is stored is opposed to the photosensitive drum 123. When magenta toner is supplied from the developing roller to the photosensitive drum 123, the rotating frame 122 is rotated so that the developing unit B 4 that stores cyan toner is opposed to the photosensitive drum 123. After the cyan toner is supplied to the photosensitive drum 123, the developing device B <b> 2 that stores the black toner is opposed to the photosensitive drum 123 to supply the black toner to the photosensitive drum 123. At this time, when the black toner in the developing device B2 has already been consumed, the black toner is supplied with the developing device B5 facing the photosensitive drum 123. As described above, since the developing devices 126 that store the frequently used black toner are disposed at two locations, the number of times of toner replenishment can be reduced.

  A case where a plurality of image forming processing operations are successively executed for a black image will be specifically described. When the image forming operation is continued for less than a certain number (for example, 10), toner is supplied from the same developing device 126 to the photosensitive drum 123. When the image forming operation is more than a certain number, the developing device for supplying toner to the photosensitive drum 123 is used. An image forming operation is performed while changing 126. Specifically, when a black image is first formed, black toner stored in the developing device B 4 is supplied to the photosensitive drum 123. When a black image is printed in the second image formation processing operation after the first image formation processing operation, black toner stored in the developing device B2 is supplied to the photosensitive drum 123. Thereafter, the developing devices B4 and B2 alternately supply toner to the photosensitive drum 123. Here, even when a plurality of image forming processes are continuously executed for a black image, the specific developing device 126 is long because the rotating frame 122 rotates and changes the position of each developing device 126. Less affected by approaching the time fixing unit 130. Further, since both the case of printing a full-color image and the case of printing only black are rotated well by the rotating frame 122, the toner in the developing device 126 is easily stirred, and the toner caused by the toner not being stirred. Can be prevented from deteriorating.

  At this time, the sheet is conveyed from the sheet storage unit 140 to the lower side of the intermediate transfer belt 125, and the full color toner image formed on the photosensitive drum 123 is transferred to the sheet by the intermediate transfer belt 125. The sheet on which the image has been transferred is conveyed to the fixing unit 130 by the sheet conveying unit 150, and the image is fixed on the sheet. The sheet on which the image is fixed is discharged from the discharge unit 160.

[Third embodiment]
1. Configuration As shown in FIG. 7, the color printer 210 includes an image forming unit 220, a fixing unit 230, a paper storage unit 240, a paper transport unit 250, and a discharge unit 260. Here, since the configuration of the image forming unit 220 other than the rotary developing device 221 is the same as that of the first embodiment, the description thereof is omitted.

  The rotary developing device 221 includes a rotary frame 222 and five developing units 226 supported by the rotary frame 222. The rotation frame 222 is a member that can rotate around an axis parallel to the rotation axis of the photosensitive drum 223, and is rotated by a drive mechanism including a motor and a gear (not shown). The rotating frame 222 has five sections that are divided into five equal parts in the circumferential direction by a partition frame that extends radially from the center of the rotating shaft. As shown in FIG. 8, yellow, magenta, Developers 226 corresponding to the order of cyan, black, and black are arranged.

2. Operation The operation when the toner is supplied from the developing unit 226 to the photosensitive drum 223 will be specifically described with reference to FIG. When image data of an image to be printed is transmitted from the computer, the surface of the photosensitive drum 223 is charged, and laser light is irradiated from the laser unit 224 to the surface of the photosensitive drum 223 based on the image data. Then, each color toner is supplied from the rotary developing device 221 to the surface of the photosensitive drum 223, and a full-color toner image is formed on the photosensitive drum 223.

  Specifically, when printing a full-color image, the rotating frame 222 rotates and the developing device C1 that stores yellow toner is opposed to the photosensitive drum 223. When yellow toner is supplied to the photosensitive drum 223 by the developing roller, the rotating frame 222 is then rotated so that the developing device C2 storing magenta toner is opposed to the photosensitive drum 223. When magenta toner is supplied from the developing roller to the photosensitive drum 223, the rotating frame 222 is rotated to cause the developing unit C <b> 3 that stores cyan toner to face the photosensitive drum 223. After the cyan toner is supplied to the photosensitive drum 223, the developing unit C4 that stores the black toner is opposed to the photosensitive drum 223, and the black toner is supplied to the photosensitive drum 223. At this time, if the black toner in the developing device C4 has already been consumed, the black toner is supplied with the developing device C5 facing the photosensitive drum 223. As described above, since the developing units 226 that store the frequently used black toner are disposed at two locations, the number of times of toner replenishment can be reduced.

  In addition, when the image forming processing operation is continuously performed for a black image, first, the toner stored in the developing device C4 is supplied to the photosensitive drum 223. When the toner in the developing device C4 runs out, the toner stored in the developing device C5 is supplied to the photosensitive drum 223.

  At this time, the sheet is conveyed from the sheet storage unit 240 to the lower side of the intermediate transfer belt 225, and the full-color toner image formed on the photosensitive drum 223 is transferred to the sheet by the intermediate transfer belt 225. The sheet on which the image has been transferred is conveyed to the fixing unit 230 by the sheet conveying unit 250, and the image is fixed on the sheet. The sheet on which the image is fixed is discharged from the discharge unit 260.

[Other embodiments]
(A) In the above-described embodiment, five or six developing devices have been described. However, the present invention is not limited to this and may be seven or more.

  (B) In the above-described embodiment, the image forming apparatus of the four-color developing system has been described. However, the present invention is not limited to this, and the developing may be performed with three-color developing or five or more colors.

  (C) In the above-described embodiment, the case where two or more developing devices that store black toner are provided has been described. However, the present invention is not limited to this, and development that stores toner of other colors such as yellow and magenta. A plurality of vessels may be provided. This is effective when many specific colors are used.

1 is an overall schematic diagram of a color printer 1. FIG. FIG. 3 is an enlarged cross-sectional view of the developing device 26. 1 is a schematic diagram of a rotary developing device according to a first embodiment. The block diagram which shows the control part 7. FIG. The block diagram which shows the control part 7. FIG. 1 is an overall schematic diagram of a color printer 110. FIG. FIG. 9 is a schematic diagram of a rotary developing device according to a second embodiment. 1 is an overall schematic diagram of a color printer 210. FIG. FIG. 10 is a schematic diagram of a rotary developing device according to a third embodiment.

Explanation of symbols

1 Color printer (image forming device)
7 Controller 71 Recognizing means 72 Rotating position control means 21 Rotating developing device 22 Photosensitive drum (image carrier)
26 Developer (container body)
211 Rotating frame (frame member)
262 Toner container 101 Color printer (image forming apparatus)
121 Rotating developing device 122 Rotating frame (frame member)
123 Photosensitive drum (image carrier)
201 Color printer (image forming apparatus)
221 Rotating developing device 222 Rotating frame (frame member)
223 Photosensitive drum (image carrier)

Claims (6)

A rotary developing device used in an image forming apparatus capable of forming a color image,
A plurality of container bodies each containing a developer corresponding to each color, and two or more containing the same color developer;
A frame member that supports the plurality of container bodies and is rotatable;
Rotating developing device.   The rotary developing device according to claim 1, wherein the container main bodies containing developers of the same color are arranged so as not to be adjacent to each other.   The rotary developing device according to claim 1, wherein the frame member supports five or more container bodies.   4. The rotary developing device according to claim 1, wherein two or more of the plurality of container main bodies store a black developer. 5. A rotary developing device according to claims 1 to 4,
An image carrier disposed adjacent to the rotary developing device and supplied with a developer from the rotary developing device;
An image forming apparatus. Recognizing means for recognizing continuous printing using the developer of two or more container bodies containing the same color developer;
A rotation position control means for controlling the rotation position of the frame so as to supply the developer from a different container body for each printing operation when the recognition means recognizes continuous printing;
Further comprising a control unit having
The image forming apparatus according to claim 5.

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