JP6436801B2 - Image forming unit and image forming apparatus - Google Patents

Description

  The present invention relates to an image forming unit used for an electrophotographic recording system and an image forming apparatus including the same.

  Conventionally, in an image forming unit used for an electrophotographic recording method, toner supplied from a toner container is attached to a developing roller while stirring, and toner on the developing roller is attached to an electrostatic latent image portion on a photosensitive drum. Some are developed.

  Japanese Patent Laying-Open No. 2012-189843 (Patent Document 1) describes an image forming unit capable of obtaining a sufficient image density. According to Patent Document 1, a photosensitive drum, a developing roller, and first and second supply rollers are provided, and a sufficient amount of developer is supplied from each developer supply member to the developer carrier. it can.

JP 2012-189843 A

  According to the prior art, the residual toner that has not adhered to the electrostatic latent image portion on the photosensitive drum from the developing roller is peeled off from the developing roller, stirred together with the toner supplied from the toner storage unit, and again developed. Adhere to the top. However, the residual toner is deteriorated due to friction, charging, or the like as compared with the toner just supplied from the toner container, and the amount and the color attached to the electrostatic latent image portion on the photosensitive drum are changed. . When there is a difference in the amount of residual toner in the development width direction, there is a problem that a problem may occur in the development quality such as density unevenness and density level difference.

  The problem to be solved by the present invention is to make the toner uniform and adhere to the electrostatic latent image portion on the photosensitive drum when stirring the new toner just supplied from the toner container and the residual toner. It is possible to provide an image forming unit and an image forming apparatus provided with the image forming unit in which the amount and color are not changed in the development width direction, and the development quality such as density unevenness and density step does not occur. It is.

In order to solve the above problems, an image forming unit according to the present invention includes an image carrier and a development unit, and the development unit includes a developer carrier for attaching a developer to the image carrier, and the developer carrier. A first developer supply member for supplying the developer to the body and peeling off the developer remaining on the developer carrier, and rotation of the developer carrier relative to the first developer supply member A second developer supply member disposed on the upstream side in the direction and configured to supply the developer to the developer carrying member and peel the developer remaining on the developer carrying member; An agitating member for agitating the developer in the developing unit by rotating the developer in the circumferential direction of the first rotating shaft by rotating with respect to the shaft; and rotating with respect to the second rotating shaft To transport the developer in the developing width direction. Stirring was provided with a conveying member for conveying the developer in the developing unit, further, the stirring member, the developer is supplied from the second developer supply member to said developer carrying member A rotation center is provided on the downstream side in the rotation direction of the developer carrying member with respect to the position, and is formed of an elliptical plate provided at a predetermined angle other than parallel and orthogonal to the first rotation axis. The wing has at least one or more wings .

  According to the present invention having the above-described configuration, the toner in the developing unit is made uniform by stirring the new toner just supplied to the developing unit and the residual toner, and the electrostatic latent image portion on the photosensitive drum is formed. An image forming unit capable of developing without causing a problem in developing quality such as density unevenness and density step, and the like, and image forming provided with the image forming unit, because the amount and color of the toner to be attached do not change in the developing width direction. An apparatus can be provided.

1 is a configuration diagram illustrating an image forming apparatus according to a first embodiment. FIG. 2 is an exploded perspective view illustrating a configuration of an image forming unit of the image forming apparatus according to the first embodiment. FIG. 3 is an explanatory diagram illustrating a configuration of a developing unit of the image forming unit according to the first embodiment. It is explanatory drawing which shows the structure of the conveyance spiral of the developing unit regarding 1st Embodiment, and a stirring spiral. It is explanatory drawing which shows the structure of the image development part of the image formation part regarding 2nd Embodiment. It is explanatory drawing which shows the structure of the stirring spiral of the developing unit regarding 2nd Embodiment. It is explanatory drawing which shows the structure of the image development part of the image formation part regarding 3rd Embodiment. It is explanatory drawing which shows the structure of the stirring spiral of the developing unit regarding 3rd Embodiment.

(First embodiment)
Hereinafter, a first embodiment of the present invention will be described. FIG. 1 is a configuration diagram illustrating an image forming apparatus according to the first embodiment. The image forming apparatus 10 forms an image on the printing paper 101 by an electrophotographic recording method. Therefore, the image forming apparatus 10 has a paper feed cassette 100. In FIG. 1, a paper cassette 100 has printing paper 101 stacked therein, is supported by fixing bases 115 a and 115 b in the Y-axis direction, and is detachably attached to the image forming apparatus 10. A paper stacking plate 102 that is rotatably supported by a support shaft 102 a is provided inside the paper feed cassette 100, and the printing paper 101 is stacked on the paper stacking plate 102. On the feeding side of the paper feed cassette 100, a lift-up lever 103 is disposed on a support shaft 103a so as to be rotatable, and the support shaft 103a is engaged with a motor 104 so as to be able to contact and separate. When the paper feed cassette 100 is inserted into the image forming apparatus 10, the lift-up lever 103 and the motor 104 are engaged, and a control unit (not shown) drives the motor 104. As the lift-up lever 103 rotates, the tip of the lift-up lever 103 lifts the bottom of the paper stacking plate 102, and the printing paper 101 stacked on the paper stacking plate 102 rises.

  Then, when the printing paper 101 rises to a certain height, it comes into contact with the pickup roller 202 and the rise detection unit 201 detects this, and the control unit stops the motor 104 based on the information detected by the rise detection unit 201. The pickup roller 202 forms a paper feeding portion 200 together with a feed roller 203 and a retard roller 204 arranged in a pair in contact with each other. The pickup roller 202 and the feed roller 203 are rotationally driven in the direction of an arrow by a motor (not shown), and a one-way clutch mechanism (not shown) is incorporated therein, so that even when the rotational driving is stopped, the pickup roller 202 and the feed roller 203 can idle in the direction of the arrow. ing. Accordingly, the pick-up roller 202 pulls out the printing paper 101 abutted from the inside of the paper feed cassette 100, and the feed roller 203 and the retard roller 204 are provided as one sheet even when a plurality of printing papers 101 are drawn out simultaneously. The print sheets 101 are sequentially fed out to the conveyance path one by one.

  In the conveyance direction A of the printing paper 101, on the downstream side of the paper feeding unit 200, the driving timings of the paper sensor 301, the conveyance roller pair 302 for regulating the skew of the printing paper 101, and the next conveyance roller pair 304 are detected in order. A paper sensor 303, a pair of conveyance rollers 304 and 305 for feeding the printing paper 101 to the image forming unit 400 as an image forming unit, and a writing sensor 305 for taking a writing timing in the image forming unit 400 are provided. Power is transmitted to these transport roller pairs 302, 304, and 305 from a transport drive motor (not shown) via drive transmission means such as a gear (not shown).

  A multi-purpose tray (MPT) 600 for feeding sheets 606 stacked on a sheet stacking plate 604 is provided at the right end in FIG. 1, that is, on the right side of the image forming apparatus 10. The MPT 600 includes a paper stacking plate 604 on which the paper 606 is stacked, a pickup roller 602 that feeds the paper 606, a paper feed roller 601 that feeds the fed paper to the apparatus body, and a paper feed roller for separating the fed paper into one sheet. It consists of a retard roller 603 urged by 601.

  The image forming unit 400 includes four process units 400K, 400Y, 400M, and 400C that respectively form yellow, magenta, cyan, and black images, which are mounted on the upper portion of the intermediate transfer belt unit 700. Yes. Since the internal configurations of the process units 400K to 400C are common, the internal configuration of the black process unit 400K will be described as an example.

  In the process unit 400K, a photosensitive drum 401 as an image carrier is disposed so as to be rotatable in the arrow direction. Around the photosensitive drum 401, a charging roller 402 that charges the surface of the photosensitive drum 401 by charging the surface of the photosensitive drum 401 in order from the upstream side in the rotation direction, and selectively applies light to the surface of the charged photosensitive drum 401. An exposure device 850 is provided for forming an electrostatic latent image by irradiating. Further, a developing roller 404 as a developer carrying member for forming a toner image by attaching black toner to the surface of the photosensitive drum 401 on which the electrostatic latent image is formed, and developing the toner on the photosensitive drum 401. A drum cleaning unit 405 is provided for removing residual toner remaining after the transfer. The toner storage unit 406K stores black toner in order to supply black toner to the process unit 400K. In FIG. 1, illustration of a toner supply unit that supplies toner from the toner storage unit 406K to the process unit 400K is omitted. The drums or rollers used in each of these devices rotate by receiving power from a drive source (not shown) via a gear or the like.

  The intermediate transfer belt unit 700 transfers the toner image formed by the image forming unit 400 to the intermediate transfer belt 701, and further transfers the toner image to the printing paper 101 supplied from the paper feed cassette 100 or the MPT 600. The intermediate transfer belt unit 700 is printed with a drive roller 702 driven by a driving unit (not shown), a tension roller 703 that applies tension to the intermediate transfer belt 701 by an urging means such as a coil spring, and the secondary transfer roller 707 facing the roller. The image forming apparatus includes a secondary transfer backup roller 704 that transfers a toner image onto the sheet 101, and an intermediate transfer belt 701 stretched around the rollers. Further, a primary transfer roller 705 to which a predetermined voltage is applied in order to transfer a toner image formed on the photoconductive drum 401 disposed opposite to the photoconductive drum 401 onto the intermediate transfer belt 701, A belt cleaning unit 706 that removes toner remaining on the transfer belt 701 is included.

  The fixing unit 500 includes a roller pair of an upper roller 501 having a halogen lamp 503a serving as a heat source and having a surface formed of an elastic body, and a lower roller 502 having a halogen lamp 503b also serving as a heat source and having a surface formed of an elastic body. Become. The fixing unit 500 applies heat and pressure to the toner image on the printing paper 101 sent out from the image forming unit 400 to melt the toner image, and fixes the image on the printing paper 101.

  Thereafter, the printing paper 101 is conveyed by the discharge roller pairs 504a, 504b, 504c, and 504d, and is eventually discharged to the stacker unit 505. Power is transmitted to these discharge roller pairs from a drive source (not shown) via drive transmission means (not shown). The driving timings of the discharge roller pairs 504a, 504b, 504c, and 504d are detected by a paper sensor 506 provided at the output unit of the fixing unit 500.

  FIG. 2 is an exploded perspective view showing the configuration of the image forming unit of the image forming apparatus according to the first embodiment. The image forming unit 400 as an image forming unit includes a photosensitive drum 401 as an image carrier provided at the center, and a photosensitive member return unit 407 and a developing unit 408 provided on the left and right sides of the photosensitive drum 401. . The photoreceptor return unit 407 includes the above-described charging roller 402 and the cleaning unit 405 and is attached to the photoreceptor drum 401. As will be described later, the developing unit 408 includes a developing roller 404 as a developer carrying member, and urges the photosensitive drum 401.

  The toner supplied from the toner container 406 is supplied into the developing unit 408 from a toner supply port 408 a provided at the upper part of the developing unit 408. The toner supply port 408 a is provided at the central portion of the developing unit 408 in the developing width direction, that is, at the upper portion of the central portion of the printing paper 101 in the width direction (Z axis). The size of the toner supply port 408a in the development width direction is smaller than the maximum development width.

  FIG. 3 is an explanatory diagram illustrating the configuration of the developing unit of the image forming unit according to the first embodiment. Below the toner supply port 408a in the developing unit 408, a developing roller 404 having a rotation shaft in the developing width direction is disposed. Further, in the developing unit 408, supply roller pairs 409-1 and 409-2 as a developer supply member for supplying charged toner to the developing roller 404 are arranged in parallel to the developing roller 404. In the developing unit 408, a developing blade 410 for making the toner layer thickness on the developing roller 404 constant is disposed.

  The developing roller 404 has a metal shaft surface covered with a conductive elastic body such as urethane. The developing roller 404 is disposed so as to contact the surface of the photosensitive drum 401 on the downstream side of the exposure device 850 in the rotation direction of the photosensitive drum 401 (see FIG. 1). The developing roller 404 has a gear at the end of the shaft, and rotates in a direction opposite to the rotation direction of the photosensitive drum 401 by the drive transmission from the photosensitive drum 401. A high voltage is applied to the developing roller 404 at the same time as the rotation starts, and an electric field is formed between the developing roller 404 and the surface of the photosensitive drum 401, and this electric field causes toner to adhere to the electrostatic latent image portion on the surface of the photosensitive drum 401. Let

  Each of the supply roller pairs 409-1 and 409-2 is obtained by coating the surface of a metal shaft with a foaming elastic body such as silicon. It is disposed so as to contact the developing roller 404. In this way, the supply roller pair 409-1 and 409-2 supplies the toner to the developing roller 404 and peels off the toner remaining on the developing roller 404.

  The supply roller pairs 409-1 and 409-2 have gears at the ends of the shafts, respectively, and rotate in the same direction as the rotation direction of the developing roller 404 by the drive transmission from the photosensitive drum 401. The supply roller pair 409-1 and 409-2 are in sliding contact with the developing roller 404 to frictionally charge the toner and supply the toner to the developing roller 404.

  The two supply rollers 409-1 and 409-2 are provided at an interval in the vertical direction, and are respectively disposed in contact with the developing roller 404. Hereinafter, the one arranged on the upper side is referred to as a first supply roller 409-1 as a first developer supply member, and the one arranged on the lower side is a second supply roller as a second developer supply member. The supply roller 409-2. The first supply roller 409-1 is disposed upstream of the developing blade 410 in the rotation direction of the developing roller 404. The second supply roller 409-2 is disposed on the upstream side in the rotation direction of the developing roller 404 with respect to the first supply roller 409-1.

  Since the photosensitive drum 401 is disposed upstream of the second supply roller 409-2 in the rotation direction of the developing roller 404, the position where the second supply roller 409-2 is disposed is the residual toner. This corresponds to the most upstream direction of the developing roller 404 in the rotation direction.

  Furthermore, in the developing unit 408, a transport spiral 411 as a transport member to be described below is arranged in parallel with the developing roller 404 in the vicinity of the first supply roller 409-1. Further, between the first supply roller 409-1 and the second supply roller 409-2 disposed below the first supply roller 409-1, a stirring spiral 412 as a stirring member, which will be described below, is parallel to the developing roller 404. It is arranged.

  Further, the stirring spiral 412 has a developing roller with respect to a position where the toner is supplied from the first supply roller 409-1 to the developing roller 404, that is, a position where the first supplying roller 409-1 and the developing roller 404 are in contact with each other. A rotation center is provided upstream of the rotation direction of 404. That is, in other words, the stirring spiral 412 is provided with a rotation center on the downstream side in the rotation direction of the developing roller 404 with respect to the position where the toner is supplied from the second supply roller 409-2 to the developing roller 404. Therefore, as shown in FIG. 3, the transport spiral 411 is provided directly below the toner supply port 408 a, and the agitation spiral 412 is provided below the transport spiral 411. That is, the transport spiral 411 is disposed between the toner supply port 408 a and the agitation spiral 412.

  FIG. 4 is an explanatory diagram showing the configuration of the transport spiral and agitation spiral of the developing unit according to the first embodiment. 4A shows a conveying spiral 411 as a conveying member for conveying the toner of the developing unit 408, and FIG. 4B shows an agitating spiral 412 as an agitating member for agitating the toner of the developing unit 408.

  As shown in FIG. 4A, the conveying spiral 411 is symmetrically configured by a right-handed spiral 411a and a left-handed spiral 411b as continuous spiral wings, with a central portion in the developing width direction (Z-axis direction) as a boundary. Yes. As a result, the conveying spiral 411 conveys the toner dropped from the toner supply port 408a to the left and right in the developing width direction and agitates the toner.

  On the other hand, as shown in FIG. 4 (b), the stirring spiral 412 has a spiral shaft 412a having an elliptical plate 412a formed of a plurality of elliptical plates inclined obliquely with respect to the spiral shaft 412-1 serving as a rotation shaft. At least one or more are provided over the entire region from one end of one to the other end. The elliptical plate 412a is provided at a predetermined angle other than parallel and orthogonal to the spiral axis 412-1. The direction in which the elliptical plate 412a is inclined is the opposite direction on the left and right with respect to the central portion of the developing width direction (Z-axis direction). Thereby, the stirring spiral 412 stirs the toner by moving the toner in the circumferential direction of the spiral shaft 412-1 (Z axis).

  Next, operations and actions of the transport spiral 411 and the stirring spiral 412 of the developing unit 408 will be described. The toner supplied from the toner storage unit 406 passes through the toner supply port 408a and falls into the developing unit 408 along the arrow A shown in FIG. The toner supplied into the developing unit 408 is conveyed in both the right and left directions of the developing width indicated by the arrows B and C by the conveying spiral 411 rotating in the arrow R direction shown in FIG.

  Eventually, the developing unit 408 is filled with toner and adheres to the developing roller 404 via the first and second supply roller pairs 409-1 and 409-2. The toner on the developing roller 404 has a constant layer thickness by the developing blade 410 and adheres to the electrostatic latent image portion of the photosensitive drum 401. Part of the toner remaining on the developing roller 404 without adhering to the photosensitive drum 401 is peeled off by the developing unit 408, that is, part of the toner is supplied to the first and second supply roller pairs 409-1 and 409-2. When it comes into contact, it is released into the developing unit 408 again by peeling.

  More specifically, the residual toner on the developing roller 404 is first peeled off by the second supply roller pair 409-2 corresponding to the most upstream in the rotation direction of the developing roller 404. The residual toner peeled off here is sent to the vicinity of the stirring spiral 412, particularly to the lower side, by the second supply roller pair 409-2. Further, the residual toner that could not be peeled off by the second supply roller pair 409-2 on the developing roller 404 is the first supply roller pair 409- disposed downstream of the second supply roller pair 409-2. 1 peels off. The residual toner thus peeled off is sent to the vicinity of the stirring spiral 412, particularly to the upper side, by the first supply roller pair 409-1.

  The residual toner released in the vicinity of the agitation spiral 412 is rotated by the agitation spiral 412 rotating in the direction of arrow R shown in FIG. The residual toner on the lower side of the stirring spiral 412 is sent to the upper side of the stirring spiral 412 as shown by an arrow E. That is, the residual toner is moved in the circumferential direction of the spiral shaft 412-1 and stirred. The residual toner sent to the upper side of the stirring spiral 412 is stirred by the transport spiral 411.

  In addition, new toner before adhering to the developing roller 404 supplied from the toner supply port 408a is also added to the lower side of the stirring spiral 412 along the arrow D by the stirring spiral 412. The new toner below the stirring spiral 412 is conveyed along the arrow E to the upper side of the stirring spiral 412 in the circumferential direction of the spiral shaft 412-1.

  In this process, new toner before adhering to the developing roller 404 and residual toner are mixed. The mixed toner is conveyed in both the left and right directions of the developing width by the conveying spiral 411 and is agitated with the surrounding toner by the agitating spiral 412 again. In the developing width direction, the toner agitated at a location with a large amount of residual toner and the toner agitated at a location with a small amount of residual toner are mixed by the conveying spiral 411 and are newly added before adhering to the developing roller 404 in the development unit 408. The mixing ratio of toner and residual toner is made uniform.

  As described above, in this embodiment, the new toner just supplied to the developing unit 408 and the residual toner are agitated to make the toner in the developing unit 408 uniform, and the electrostatic on the photosensitive drum 401 is An image forming unit capable of developing without causing problems in development quality such as density unevenness and density level difference by preventing the amount of toner and color attached to the latent image portion from changing in the development width direction, and the image forming unit An image forming apparatus can be provided.

(Second Embodiment)
Next, a second embodiment will be described. In addition, about the same component as 1st Embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operation / action and effect as in the first embodiment is omitted. FIG. 5 is an explanatory diagram showing the configuration of the developing unit of the image forming unit according to the second embodiment. The stirring spiral 413 as the stirring member of the developing unit 408 according to the second embodiment is similar to the stirring spiral 412 of the first embodiment, and the first and second supply roller pairs 409-1 and 409-2. In the meantime, the toner in the developing unit 408 is agitated by being arranged in parallel with the developing roller 404 and below the conveying spiral 411. The configuration of the stirring spiral 413 is as described below, and the rest is the same as that of the first embodiment.

  FIG. 6 is an explanatory diagram showing the configuration of the stirring spiral of the developing unit according to the second embodiment. 6A shows the entire stirring spiral 413, and FIG. 6B shows a partially enlarged view. The agitation spiral 413 is provided with a plurality of pairs of spiral wings 413a and 413b including left-handed spiral wings 413a and right-handed spiral wings 413b. The left-handed spiral wing 413a turns the spiral shaft 413-1 counterclockwise from one end to the other end in the developing width direction (Z-axis direction) of the spiral shaft 413-1 as a rotation shaft, from the back side to the front side of the spiral shaft 413-1. A half circumference is formed so as to wind.

  Similarly, the right-handed spiral blade 413b also turns the spiral shaft 413-1 clockwise from one end to the other end in the developing width direction (Z-axis direction) of the spiral shaft 413-1 from the back side to the front side of the spiral shaft 413-1. A half circumference is formed so as to be wound around. Thus, the left-handed spiral wing 413a and the right-handed spiral wing 413b are formed symmetrically with respect to the spiral shaft 413-1 and are paired together. Therefore, a plurality of pairs of spiral blades 413a and 413b are formed from one end to the other end in the development width direction (Z-axis direction) of the spiral shaft 413-1. The direction in which the left-handed spiral wing 413a and the right-handed spiral wing 413b are wound is opposite to the left and right with respect to the central portion in the developing width direction (Z-axis direction). As a result, the stirring spiral 413 stirs the toner by moving the toner in the circumferential direction of the spiral shaft 413-1 (Z axis). Further, the angle at which the left-hand spiral wing 413a and the right-hand spiral 413b are formed on the spiral shaft 413-1 is larger than the repose angle of the toner.

  Next, the operation / action of the stirring spiral 413 of the developing unit 408 relating to the second embodiment will be described. The toner in the vicinity of the stirring spiral 413 rotating in the arrow R direction shown in FIG. 6A is not conveyed in the developing width direction because the angle formed by the spiral blades 413a and 413b is larger than the repose angle of the toner. Then, it is moved in the circumferential direction of the spiral axis (Z axis) and stirred. That is, the toner on the upper side of the stirring spiral 413 moves to the lower side of the stirring spiral 413 as indicated by the arrow F, and the toner on the lower side of the stirring spiral 413 moves to the upper side of the stirring spiral 413 as shown by the arrow G, respectively. It is conveyed in the circumferential direction of the Z axis.

  As a result, the new toner before adhering to the developing roller 404 and the residual toner are mixed, and the mixed toner is transported in the developing width direction by the transport spiral 411, and again stirred with surrounding toner by the stirring spiral 413. The Toner agitated at a location where there is a lot of residual toner in the developing width direction and toner agitated at a location where there is little residual toner are mixed by the conveying spiral 411 and new toner before adhering to the developing roller 404 in the developing unit 408. And the mixing ratio of the residual toner are made uniform.

  As described above, in this exemplary embodiment, the angle at which the spiral blades 413a and 413b of the stirring spiral 413 are formed is larger than the repose angle of the toner, so that the toner can be efficiently stirred. Further, the new toner just supplied to the developing unit 408 and the residual toner are agitated to make the toner in the developing unit 408 uniform, and the amount of toner attached to the electrostatic latent image portion on the photosensitive drum 401 Color does not change in the development width direction. Therefore, it is possible to provide an image forming unit capable of developing without causing problems in developing quality such as density unevenness and density level difference, and an image forming apparatus including the image forming unit.

(Third embodiment)
Next, a third embodiment of the present invention will be described. In addition, about the same component as 1st, 2nd embodiment, the description is abbreviate | omitted by providing the same code | symbol. Also, the description of the same operations / actions and effects as those in the first and second embodiments will be omitted. FIG. 7 is an explanatory diagram showing the configuration of the developing unit of the image forming unit according to the third embodiment. The stirring spiral 414 as the stirring member of the developing unit 408 according to the third embodiment is similar to the stirring spiral 412 of the first embodiment, and the first and second supply roller pairs 409-1 and 409-2. In the meantime, the toner in the developing unit 408 is agitated by being arranged in parallel with the developing roller 404 and below the conveying spiral 411. The configuration of the stirring spiral 414 is as described below, and the rest is the same as that of the first embodiment.

  FIG. 8 is an explanatory diagram showing the configuration of the stirring spiral of the developing unit according to the third embodiment. FIG. 8A shows the entire stirring spiral 414, and FIG. 8B shows a partial enlargement of the stirring spiral 414. The stirring spiral 414 is not a single continuous spiral wing, but includes a plurality of spiral wings 414a, 414b, and the like. The spiral wing 414a is, for example, left-handed from the back side to the front side of the spiral shaft 414-1 from one end to the other end in the development width direction (Z-axis direction) of the spiral shaft 414-1 as a rotation shaft. A half circumference is formed so as to wind. Thereafter, the other spiral wings 414b, 414c and the like are formed in the same manner.

  In the present embodiment, adjacent spiral wings 414a and 414b are provided to overlap each other by a certain distance H. A plurality of spiral wings 414a, 414b and the like are provided in the entire region from one end to the other end of the spiral shaft 414-1. The winding direction of the spiral wings 414a, 414b, etc. is the opposite direction on the left and right with respect to the central part of the developing width direction (Z-axis direction) of the spiral shaft 414-1. Thereby, the stirring spiral 414 moves the toner in the circumferential direction of the spiral shaft 414-1 (Z axis) and stirs.

  Next, the operation and action of the stirring spiral 414 of the developing unit 408 relating to the third embodiment will be described. As shown in FIG. 8, the toner in the vicinity of the stirring spiral 414 rotating in the direction of arrow R indicates that the toner on the upper side of the stirring spiral 414 moves to the lower side of the stirring spiral 414 along the arrow F, and the lower side of the stirring spiral 414. The toner in the toner is conveyed along the arrow G to the upper side of the stirring spiral 414 in the circumferential direction of the spiral shaft 414-1 (Z axis).

  Further, since the positions where the adjacent spirals of the stirring spiral 414 are overlapped, the adjacent spirals while stirring the toner in the vicinity of the stirring spiral 414 in the circumferential direction of the spiral shaft 414-1 (Z axis). It is conveyed along arrows B and C. As a result, stirring in the developing width direction can be performed while stirring the toner in the vicinity of the stirring spiral 414, so that the new toner before adhering to the developing roller 404 and the residual toner are mixed earlier, and the developing roller in the developing unit 408 is mixed. The mixing ratio of new toner and residual toner before adhering to 404 is made uniform.

  As described above, in the present embodiment, while stirring the toner in the circumferential direction of the spiral shaft 414-1 (Z axis) as the rotation axis by the stirring spiral 414, the toner stirring in the developing width direction can be performed at the same time. The toner in the developing unit 408 is uniformized more quickly, and the toner amount and color attached to the electrostatic latent image portion on the photosensitive drum 401 do not change in the developing width direction. The present invention provides an image forming unit that enables development without causing problems in development quality, and an image forming apparatus including the image forming unit.

  In the present embodiment, an example is shown in which the four process units 400K to 400C are used and applied to the image forming apparatus 10 that transfers the toner image onto the printing paper 101 by the intermediate transfer belt. However, the present invention is not limited to this example. And included in an image forming apparatus that transfers a toner image directly from the process units 400K to 400C to the printing paper 101, a single-color image forming apparatus that uses one process unit 400K, a copier that uses them, an automatic document reader, and the like. It can also be implemented in an image forming apparatus.

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 400 Image forming part 401 Photosensitive drum 404 Developing roller 408 Developing unit 408a Toner supply port 409-1 First supply roller 409-2 Second supply roller 411 Conveying spiral 411a Right-hand spiral 411b Left-hand spiral 412 Stirring Spiral 412a Elliptic plate 412-1 Spiral shaft 413 Stirring spiral 414 Stirring spiral

Claims (7)

Including an image carrier and a developing unit;
The developing unit is
A developer carrier for attaching a developer to the image carrier;
A first developer supply member that supplies the developer to the developer carrying member and peels off the developer remaining on the developer carrying member;
The developer disposed on the upstream side in the rotation direction of the developer carrier relative to the first developer supply member, supplying the developer to the developer carrier and remaining on the developer carrier A second developer supply member for peeling
An agitation member for agitating the developer in the developing unit by moving the developer in a circumferential direction of the first rotation axis by rotating with respect to the first rotation axis ;
A transport member for transporting the developer in the developing width direction by rotating with respect to the second rotation shaft and transporting the developer in the developing unit;
Further, the agitation member is provided with a rotation center on the downstream side in the rotation direction of the developer carrier relative to a position where the developer is supplied from the second developer supply member to the developer carrier. An image forming unit comprising at least one wing made of an elliptical plate provided at a predetermined angle other than parallel and orthogonal to the first rotation axis . Including an image carrier and a developing unit;
The developing unit is
A developer carrier for attaching a developer to the image carrier;
A first developer supply member that supplies the developer to the developer carrying member and peels off the developer remaining on the developer carrying member;
The developer disposed on the upstream side in the rotation direction of the developer carrier relative to the first developer supply member, supplying the developer to the developer carrier and remaining on the developer carrier A second developer supply member for peeling
An agitation member for agitating the developer in the developing unit by moving the developer in a circumferential direction of the first rotation axis by rotating with respect to the first rotation axis;
A transport member for transporting the developer in the developing width direction by rotating with respect to the second rotation shaft and transporting the developer in the developing unit;
Further, the agitation member is provided with a rotation center on the downstream side in the rotation direction of the developer carrier relative to a position where the developer is supplied from the second developer supply member to the developer carrier. In addition, at least two wings having a predetermined angle other than parallel and orthogonal to the first rotation axis are provided with respect to the developing width direction, and the adjacent wings overlap each other by a predetermined length in the developing width direction. An image forming unit characterized by being provided . The agitation member is provided with the rotation center on the upstream side in the rotation direction of the developer carrier relative to a position where the developer is supplied from the first developer supply member to the developer carrier. The image forming unit according to claim 1, wherein: A developer supply port for supplying the developer at the top of the development unit;
The conveying member, according to claim 1 to 3 the image forming unit of any one, wherein it is arranged between the stirring member and the developer feed inlet. 5. The image forming unit according to claim 1 , wherein the conveying member includes a symmetric spiral continuous wing with a central portion in the developing width direction as a boundary . The image forming unit according to claim 4 , wherein a size of the developer supply port in the developing width direction is smaller than a maximum developing width . An image forming apparatus comprising the image forming unit according to claim 1 .

Images