Developing device and image forming apparatus

A developing device includes: a storage part in which a developer is stored; a transport body that includes a spiral blade and transports the developer via a rotation thereof; a developing body to which the developer is supplied from the transport body; an attachment part which is disposed between the transport body and the developing body and includes an opening allowing the developer supplied from the transport body to the developing body to pass and to which a sealing member sealing the opening is detachably attached; and a connection portion which extends to cross the opening at a spiral angle of the blade as viewed from the developing body toward the transport body and of which one end portion and the other end portion are connected to the attachment part.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2022-086993 filed May 27, 2022.

BACKGROUND

(i) Technical Field

The present invention relates to a developing device and an image forming apparatus.

(ii) Related Art

JP2002-372862A discloses a developing device. This developing device includes: a housing in which an opening portion facing an image carrier on which an electrostatic latent image is to be formed and a developer storage portion in which a developer is stored are formed; a developer carrier that is rotatably attached to the housing near the opening portion and carries the developer stored in the developer storage portion to transport the developer up to a development region facing the image carrier; and a partition frame part which is formed at a portion of the housing between the developer carrier and the developer storage portion and to which a partition film to be peeled off and removed immediately before use is attached. The partition frame part is formed of a partition frame plate that is formed in the shape of a plate including a frame portion to which a part of the partition film is to be attached and an opening portion which allows the developer to pass and that is attached in a case where the frame portion is inserted into an attachment groove formed in the housing.

JP2009-145674A discloses a developing device. This developing device includes: a housing that includes an opening portion open toward an image carrier on which an electrostatic latent image is to be formed and a developer storage portion in which a developer is stored; a developer carrier that is rotatably attached to the housing near the opening portion and carries the developer stored in the developer storage portion to transport the developer up to a development region facing the image carrier; a partition frame body that includes a communication hole provided in a groove formed in a portion of the housing between the developer carrier and the developer storage portion and allowing the developer storage portion to communicate with the opening portion; a partition part that is provided on one of the surface and back of the partition frame body, closes the communication hole during no use to isolated the developer storage portion from the opening portion, and is peeled off immediately before use to open the communication hole and to allow the developer storage portion to communicate with the opening portion; and a close contact part that is provided at a portion where the partition frame body is inserted into the groove of the housing to allow the partition frame body to be in close contact with the groove.

SUMMARY

A developing device including a storage part in which a developer is stored, a transport body that includes a spiral blade and transports the developer via the rotation thereof, a developing body to which the developer is supplied from the transport body, and an attachment part which is disposed between the transport body and the developing body and includes an opening allowing the developer supplied from the transport body to the developing body to pass and to which a sealing member sealing the opening is detachably attached is considered as a developing device.

In a case where the developing device includes a connection portion which extends to cross the opening in a direction orthogonal to a direction corresponding to a spiral angle of the blade as viewed from the developing body toward the transport body and of which one end portion and the other end portion are connected to the attachment part, the connection portion may hinder the movement of the developer supplied from the transport body to the developing body. For this reason, the poor supply of the developer from the transport body to the developing body may occur.

Aspects of non-limiting embodiments of the present disclosure relate to a developing device and an image forming apparatus that suppress the poor supply of a developer from a transport body to a developing body as compared to a case where a connection portion extends in a direction orthogonal to a direction corresponding to a spiral angle of a blade.

According to an aspect of the present disclosure, there is provided a developing device including: a storage part in which a developer is stored; a transport body that includes a spiral blade and transports the developer via a rotation thereof; a developing body to which the developer is supplied from the transport body; an attachment part which is disposed between the transport body and the developing body and includes an opening allowing the developer supplied from the transport body to the developing body to pass and to which a sealing member sealing the opening is detachably attached; and a connection portion which extends to cross the opening at a spiral angle of the blade as viewed from the developing body toward the transport body and of which one end portion and the other end portion are connected to the attachment part.

DETAILED DESCRIPTION

Examples of exemplary embodiments of the present invention will be described below with reference to the drawings.

Image Forming Apparatus10

The configuration of an image forming apparatus10according to the present exemplary embodiment will be described.FIG.1is a schematic diagram showing the configuration of the image forming apparatus10according to the present exemplary embodiment.

An arrow UP shown in the drawings indicates the upper side of the apparatus (specifically, a vertical upper side) and an arrow DO indicates the lower side of the apparatus (specifically, a vertical lower side). Further, an arrow LH shown in the drawings indicates the left side of the apparatus and an arrow RH indicates the right side of the apparatus. Furthermore, an arrow FR shown in the drawings indicates the front side of the apparatus and an arrow RR indicates the rear side of the apparatus. Since these directions are directions defined for the convenience of description, the configuration of the apparatus is not limited to these directions. The word “apparatus” may be omitted in each direction of the apparatus. That is, for example, “the upper side of the apparatus” may be simply referred to as “the upper side”.

Further, “left-right direction” may be used to mean “both a right side and a left side” or “any one of the right side or the left side” in the following description. “Left-right direction” may also be referred to as a lateral side, a lateral direction, and a horizontal direction. “Front-rear direction” may be used to mean “both a front side and a rear side” or “any one of the front side or the rear side”. “Front-rear direction” may also be referred to as a lateral side, a lateral direction, and a horizontal direction. Furthermore, the up-down direction, the left-right direction, and the front-rear direction are directions intersecting with each other (specifically, directions orthogonal to each other).

Further, a symbol in which “x” is written in “o” in the drawings means an arrow from the front to the back of the plane of the paper. Furthermore, a symbol in which “·” is written in “o” in the drawings means an arrow from the back to the front of the plane of the paper.

The image forming apparatus10shown inFIG.1is an apparatus for forming an image. Specifically, as shown inFIG.1, the image forming apparatus10includes a medium storage part12, a transport unit13, and an image forming unit14. Each part of the image forming apparatus10will be described below.

Medium Storage Part12and Transport Unit13

The medium storage part12is a part that stores recording mediums P in the image forming apparatus10. The recording mediums P stored in the medium storage part12are supplied to the image forming unit14. The recording medium P stored in the medium storage part12is an object on which images are to be formed by the image forming unit14. Examples of the recording medium P include a sheet, a film, and the like. Examples of the film include a resin film, a metal film, and the like. The recording medium P is not limited to the above-mentioned mediums and various recording mediums can be used.

The transport unit13transports the recording mediums P stored in the medium storage part12to a discharge unit (not shown). Specifically, as shown inFIG.1, the transport unit13includes transport members13A, such as a plurality of transport rollers, and transports the recording mediums P by the transport members13A. Examples of the transport members13A include transport members, such as a transport belt and a transport drum, and various transport members can be used.

Image Forming Unit14

The image forming unit14forms images on the recording medium P that is transported by the transport unit13(specifically, the transport members13A). Specifically, the image forming unit14forms toner images (an example of images) on the recording medium P by an electrophotographic method. More specifically, as shown inFIG.1, the image forming unit14includes toner image forming units20Y,20M,20C, and20K (hereinafter, referred to as20Y to20K), a transfer body24, and a fixing unit26.

Each of the toner image forming units20Y to20K includes a photoreceptor32. Since the toner image forming units20Y to20K have an identical configuration, the reference numerals of the respective parts of the toner image forming units20Y,20M, and20C are omitted inFIG.1.

The photoreceptor32is an example of a holding body, and is a structure that holds a latent image. Specifically, the photoreceptor32is rotated in one direction (for example, a counterclockwise direction inFIG.1). A charging device34, an exposure device36, and a developing device38are provided around the photoreceptor32in order from an upstream side in the rotation direction of the photoreceptor32.

In each of the toner image forming units20Y to20K, the charging device34charges the photoreceptor32(charging step). In addition, the exposure device36exposes the photoreceptor32, which is charged by the charging device34, to forma latent image (specifically, an electrostatic latent image) on the photoreceptor32(exposure step). The photoreceptor32holds the latent image formed by the exposure device36.

Then, the developing device38develops the latent image that is held by the photoreceptor32(developing step). Accordingly, a toner image is formed on the photoreceptor32. The specific configuration of the developing device38will be described later.

In the image forming unit14, the respective toner image forming units20Y to20K perform the respective steps, such as charging, exposure, and development, to form toner images having the respective colors, such as yellow (Y), magenta (M), cyan (C), and black (K), on the transfer body24. In addition, the image forming unit14transfers the toner images having the respective colors, which are formed on the transfer body24, to the recording medium P and fixes the toner images to the recording medium P by the fixing unit26. The image forming unit14uses an intermediate transfer method of transferring an image to the recording medium P via the transfer body24in this way.

The image forming unit may use a direct transfer method of directly transferring an image to a recording medium P without being limited to an intermediate transfer method, and various image forming units can be applied.

FIG.2is a schematic diagram showing the developing device38.FIG.3is a schematic diagram showing an attachment part60, connection portions69, and a second transport auger82to be described later of the developing device38according to the present exemplary embodiment.FIG.4is a schematic diagram showing the attachment part60, the connection portions69, and a sealing member70to be described later of the developing device38.

The developing device38shown inFIG.2is a device that develops the latent image held by the photoreceptor32as described above with a developer G. The developer G is a developer that includes toner and a magnetic carrier. Specifically, as shown inFIG.2, the developing device38includes a housing40, a first transport auger81, a second transport auger82, a developing roller50, a layer regulation member54, an attachment part60, a sealing member70, and connection portions69(seeFIG.3). Each part of the developing device38will be described below.

The housing40shown inFIG.2is an example of a storage part, and a developer G is stored in the housing40. The housing40is formed in the shape of a box having a length in the front-rear direction.

A first transport passage41and a second transport passage42through which the developer G is transported are formed in the housing40. The first transport passage41is disposed in the front-rear direction at a lower right portion of the housing40. The developer G stored in the housing40is transported in a transport direction (specifically, to one side in the front-rear direction) in the first transport passage41by the first transport auger81.

The second transport passage42is disposed along the first transport passage41to be adjacent to the first transport passage41with a partition wall43interposed therebetween. Specifically, the second transport passage42is disposed in the front-rear direction on an upper left side of the first transport passage41. A front end portion of the second transport passage42is connected to a front end portion of the first transport passage41, a rear end portion of the second transport passage42is connected to a rear end portion of the first transport passage41, and the second transport passage42is partitioned from the first transport passage41by a partition wall43at an intermediate portion between the front end portion and the rear end portion of the second transport passage42. The front end portions of the second transport passage42and the first transport passage41are connected to each other and the rear end portions thereof are connected to each other, so that the first transport passage41and the second transport passage42form a circulation passage.

The developer G supplied from the first transport passage41is stored in the second transport passage42, and the developer G is transported in a direction opposite to the transport direction (specifically, to the other side in the front-rear direction) by the second transport auger82.

In addition, in a state where the developing device38is installed in each of the toner image forming units20Y to20K, an opening portion44, which is open toward the photoreceptor32(specifically, a left side), is formed in the housing40as shown inFIG.2. The photoreceptor32in a state where the developing device38is installed in each of the toner image forming units20Y to20K is shown inFIG.2by a two-dot chain line.

First Transport Auger81and Second Transport Auger82

The first transport auger81and the second transport auger82include spiral blades81B and82B, and transport the developer G via the rotation thereof. Specifically, the first transport auger81and the second transport auger82include shaft portions81A and82A that are disposed in the front-rear direction and spiral blades81B and82B that are formed on the outer peripheries of the shaft portions81A and82A, respectively. The second transport auger82is an example of a transport body.

The first transport auger81is disposed in the first transport passage41. In a case where the shaft portion81A is rotated, the first transport auger81transports the developer G in the first transport passage41in the transport direction (specifically, to one side in the front-rear direction) by the blade81B.

The second transport auger82is disposed in the second transport passage42. In a case where the shaft portion82A is rotated, the second transport auger82transports the developer G in the second transport passage42in the opposite direction (specifically, to the other side in the front-rear direction) by the blade82B.

The developing roller50is an example of a developing body, and is a component to which the developer G is supplied from the second transport auger82. The developing roller50is provided in the housing40such that a part of the developing roller50is exposed from the opening portion44of the housing40. The layer regulation member54is provided on the lower side of the developing roller50.

The developing roller50holds the developer G supplied from the second transport auger82on the outer peripheral surface thereof, and transports the developer G to a facing position facing the photoreceptor32. The thickness of a layer of the developer G (the amount of developer) transported toward the facing position is regulated by the layer regulation member54. Then, the developer G (specifically, toner) present on the developing roller50is supplied to the photoreceptor32at the facing position, and the electrostatic latent image formed on the photoreceptor32is developed with the developer G (specifically, toner).

The attachment part60shown inFIGS.2and3is a structure to which the sealing member70(seeFIG.4) is to be attached. Specifically, the attachment part60is formed in the shape of a rectangular frame long in the front-rear direction as shown inFIG.3as viewed from the developing roller50toward the second transport auger82(that is, as viewed in a direction of an arrow A shown inFIG.2). Accordingly, the attachment part60includes a first side61and a second side62that extend in the front-rear direction while having an interval therebetween in the left-right direction, a third side63that connects a front end portion of the first side61to a front end portion of the second side62, and a fourth side64that connects a rear end portion of the first side61to a rear end portion of the second side62.

In order to make the configuration of the second transport auger82and the attachment part60easy to see, the second transport auger82and the attachment part60are shown inFIG.3to be shifted from each other in the left-right direction. However, in a case where the second transport auger82and the attachment part60are viewed in a direction of an arrow A, the second transport auger82and the attachment part60are actually disposed to overlap with each other (seeFIG.2).

The attachment part60is formed in the shape of a plate of which the thickness direction is parallel to the direction of the arrow A (seeFIG.4). That is, the attachment part60is formed in a flat shape in the direction of the arrow A. Further, the attachment part60is made of a resin material.

The direction of the arrow A shown in each drawing is a direction from the developing roller50toward the second transport auger82. Specifically, the direction of the arrow A is a direction from the central axis of the developing roller50toward the central axis of the second transport auger82in a side view.

A direction of an arrow C shown in each drawing is a direction from the second transport auger82toward the developing roller50. Specifically, the direction of the arrow C is a direction from the central axis of the second transport auger82toward the central axis of the developing roller50in a side view. That is, the direction of the arrow C is a direction opposite to the direction of the arrow A. A direction of an arrow B shown inFIG.2is a direction orthogonal to the direction of the arrow A and the direction of the arrow C.

As shown inFIG.2, the attachment part60is disposed between the second transport auger82and the developing roller50. The attachment part60is supported by the housing40. Specifically, the first and second sides61and62are inserted into recessed portions48formed in the housing40in the front-rear direction, so that the attachment part60is supported by the housing40.

As shown inFIG.3, the attachment part60includes an opening66that allows the developer G supplied from the second transport auger82to the developing roller50to pass. Specifically, the opening66is formed of a space that is surrounded by the first side61, the second side62, the third side63, and the fourth side64.

The sealing member70is a component that seals the opening66. The sealing member70is detachably attached to the attachment part60. The sealing member70allows the developer G to move from the second transport auger82to the developing roller50through the opening66by being removed.

The sealing member70is formed in a film shape (that is, a membrane shape). Specifically, the sealing member70is formed of, for example, a film made of a resin. The sealing member70is bonded to the attachment part60by, for example, fusion bonding (so-called heat sealing) to cover the opening66.

Specifically, the sealing member70includes a sealing portion72and a pull-out portion74as shown inFIG.4. The sealing portion72is a portion that seals the entire opening66. The pull-out portion74is a portion that is to be connected to one end portion72R (specifically, a rear end portion) of the sealing portion72and is to be pulled out to one side (specifically, a front side) corresponding to a direction from one end portion72R of the sealing portion72toward the other end portion72F (specifically, a front end portion). In a case where the pull-out portion74of the sealing member70is pulled out to the front side by a user, the sealing member70is detached from the attachment part60as shown inFIG.5.

The sealing member may be formed of a film made of metal, and various sealing members can be used. Further, the sealing member may be bonded to the attachment part60by a bonding method using a bonding agent, such as an adhesive, or other bonding methods.

Each connection portion69is a structural portion that is connected to the attachment part60. Specifically, each connection portion69extends to cross the opening66at a spiral angle θ of the blade82B of the second transport auger82as viewed in the direction of the arrow A, and one end portion69A and the other end portion69B of each connection portion69are connected to the attachment part60.

Specifically, one end portion69A of the connection portion69is connected to the first side61of the attachment part60, and the other end portion69B of the connection portion69is connected to the second side62of the attachment part60. That is, the connection portion69extends to the second side62from the first side61of the attachment part60.

The connection portions69are linearly formed at the spiral angle of the blade82B. Accordingly, the connection portions69are inclined with respect to the shaft portion82A of the second transport auger82. In the present exemplary embodiment, the connection portions69have a thickness identical to the thickness of the attachment part60in the direction of the arrow A and are formed integrally with the attachment part60. Further, the connection portions69are made of a material identical to the attachment part60. In the present exemplary embodiment, the connection portions69are made of a resin material.

The connection portions69may be formed separately from the attachment part60. Further, the connection portions69may be made of a material different from the material of the attachment part60.

Here, the spiral angle θ is the angle (obtuse angle) of the blade82B with respect to an axial direction of the shaft portion82A in a case where the second transport auger82is viewed from the developing roller50(that is, the second transport auger82is viewed in the direction of the arrow A).

Further, a configuration in which the connection portions69are arranged at the spiral angle θ of the blade82B does not need to be a configuration in which the arrangement direction of the connection portions69completely match the spiral angle θ of the blade82B, and also includes a case where, for example, the connection portions69are arranged to have an angle in the range of a predetermined angle (for example, ±30° from the spiral angle θ.

A width69W of the connection portion69in a rotation axis direction of the second transport auger82at a downstream end portion of the connection portion69in a supply direction from the second transport auger82toward the developing roller50(the direction of the arrow C) is less than a width69W thereof at an upstream end portion of the connection portion69.

Specifically, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is gradually reduced in the supply direction. More specifically, the connection portions69are formed at an acute angle in the supply direction.

Specifically, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is set to 1 mm or less. The width69W mentioned here is the maximum width of the connection portion69. In the present exemplary embodiment, the width69W is the width69W of the connection portion69at the upstream end portion of the connection portion69in the supply direction from the second transport auger82toward the developing roller50(the direction of the arrow C).

A plurality of connection portions69are arranged in the rotation axis direction of the second transport auger82. An interval69P between the connection portions69in the rotation axis direction is equal to or larger than a spiral interval82P of the blade82B. The spiral interval82P means an axial length of the blade82B per 360° (one turn) in a circumferential direction of the shaft portion82A.

In addition, the interval69P between the connection portions69is set to an integral multiple of the spiral interval82P of the blade82B in the present exemplary embodiment. That is, the interval69P between the connection portions69is set to be equal to a value that is the product of the spiral interval82P and an integer.

The sealing member70may be detachably attached to the connection portions69in addition to the attachment part60. In this case, the pull-out portion74is pulled out to the front side by a user, so that the sealing member70is detached from the attachment part60and the connection portions69.

Action of Present Exemplary Embodiment

In the present exemplary embodiment, one end portion69A and the other end portion69B of each connection portion69are connected to the attachment part60as shown inFIG.3.

Here, since the stiffness of the attachment part60is low in a form not including the connection portions69(hereinafter, referred to as a form A) as shown inFIG.6, the attachment part60is likely to be deformed as shown inFIG.7. Further, since the supply of a developer G from the second transport auger82to the developing roller50is hindered in a case where the first and second sides61and62are deformed inward as shown inFIG.7, the poor supply of the developer G may occur.

In contrast, since one end portion69A and the other end portion69B of each connection portion69are connected to the attachment part60in the present exemplary embodiment, the deformation of the attachment part60is suppressed as compared to the form A. As a result, according to the present exemplary embodiment, the poor supply of a developer G caused by the deformation of the attachment part60is suppressed as compared to the form A.

Further, in a case where a developer G separated from the developing roller50falls onto the second transport auger82, the developer G is likely to directly collide with the second transport auger82in the form A as shown by an arrow X ofFIG.8. For this reason, the developer G is likely to float.

In contrast, one end portion69A and the other end portion69B of each connection portion69are connected to the attachment part60in the present exemplary embodiment. Accordingly, since the developer G comes into contact with the connection portions69as shown by an arrow Y ofFIG.8in a case where a developer G separated from the developing roller50falls onto the second transport auger82, a cushioning effect is obtained as compared to the form A. For this reason, the developer G is less likely to float.

Furthermore, in the present exemplary embodiment, each connection portion69extends to cross the opening66at the spiral angle θ of the blade82B of the second transport auger82as viewed in the direction of the arrow A, and one end portion69A and the other end portion69B of each connection portion69are connected to the attachment part60.

Here, the developer G adhering to the blade82B of the second transport auger82is disposed at the spiral angle θ of the blade82B, and is supplied to the developing roller50(seeFIG.9).

For this reason, since the supply of the developer G from the second transport auger82to the developing roller50is less likely to be hindered as compared to a case where the connection portions69extend in a direction orthogonal to a direction corresponding to the spiral angle θ of the blade82B (hereinafter, referred to as a form B), the poor supply of the developer G from the second transport auger82to the developing roller50is suppressed. As a result, an image defect occurring in an image formed on the recording medium P is suppressed in the image forming apparatus10as compared to the form B.

Further, the width69W of the connection portion69in the rotation axis direction of the second transport auger82at a downstream end portion of the connection portion69in the supply direction from the second transport auger82toward the developing roller50(the direction of the arrow C) is less than the width69W thereof at an upstream end portion of the connection portion69in the present exemplary embodiment.

Here, in a case where the width69W of the connection portion69at the downstream end portion of the connection portion69in the supply direction is equal to the width69W thereof at the upstream end portion (hereinafter, referred to as a form C), a developer G separated from the developing roller50may adhere to the downstream end portion of the connection portion69and stay as denoted by reference numeral110ofFIG.10. As a result, the developer G, which stays at the downstream end portion of the connection portion69, may be supplied to the developing roller50again.

In contrast, since the width69W of the connection portion69at the downstream end portion of the connection portion69in the supply direction is less than the width69W thereof at the upstream end portion of the connection portion69in the present exemplary embodiment, the stay of a developer G separated from the developing roller50at the downstream end portion of the connection portion69is suppressed as compared to the form C.

Further, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is gradually reduced in the supply direction in the present exemplary embodiment. For this reason, the stay of a developer G separated from the developing roller50at the downstream end portion of the connection portion69is suppressed as compared to a case where the width69W of the connection portion69is reduced in stages in the supply direction.

Furthermore, the connection portions69are formed at an acute angle in the supply direction in the present exemplary embodiment. For this reason, the stay of a developer G separated from the developing roller50at the downstream end portion of the connection portion69is suppressed as compared to a case where the connection portions69are formed at an obtuse angle in the supply direction.

Moreover, the interval69P between the connection portions69in the rotation axis direction is set to be equal to or larger than the spiral interval82P of the blade82B in the present exemplary embodiment. For this reason, since the supply of a developer G from the second transport auger82to the developing roller50is less likely to be hindered as compared to a case where the interval69P between the connection portions69in the rotation axis direction is less than the spiral interval82P of the blade82B, the poor supply of the developer G from the second transport auger82to the developing roller50is suppressed.

Further, the interval69P between the connection portions69is set to an integral multiple of the spiral interval82P of the blade82B in the present exemplary embodiment. For this reason, since the supply of a developer G from the second transport auger82to the developing roller50is less likely to be hindered as compared to a case where the interval69P between the connection portions69is larger than the spiral interval82P of the blade82B and is an interval different from an integral multiple of the spiral interval82P of the blade82B, the poor supply of the developer G from the second transport auger82to the developing roller50is suppressed.

Furthermore, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is set to 1 mm or less in the present exemplary embodiment. For this reason, since the supply of a developer G from the second transport auger82to the developing roller50is less likely to be hindered as compared to a case where the width69W of the connection portion69in the rotation axis direction of the second transport auger82exceeds 1 mm, the poor supply of the developer G from the second transport auger82to the developing roller50is suppressed.

Modification Examples

The width69W of the connection portion69at the downstream end portion of the connection portion69in the supply direction is set to be less than the width69W thereof at the upstream end portion of the connection portion69in the present exemplary embodiment, but is not limited thereto. For example, the width69W of the connection portion69at the downstream end portion of the connection portion69in the supply direction may be equal to the width69W thereof at the upstream end portion of the connection portion69.

Further, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is gradually reduced in the supply direction in the present exemplary embodiment, but is not limited thereto. For example, the width69W of the connection portion69may be reduced in stages in the supply direction.

Furthermore, the connection portions69are formed at an acute angle in the supply direction in the present exemplary embodiment, but are not limited thereto. For example, the connection portions69may be formed at an obtuse angle in the supply direction. Moreover, for example, portions having a circular shape, a semicircular shape, an elliptical shape, a rhombus shape, and the like as a cross-sectional shape viewed in the left-right direction may be used as the connection portion69.

Further, the interval69P between the connection portions69in the rotation axis direction is set to be equal to or larger than the spiral interval82P of the blade82B in the present exemplary embodiment, but is not limited thereto. For example, the interval69P between the connection portions69in the rotation axis direction may be less than the spiral interval82P of the blade82B.

Furthermore, the interval69P between the connection portions69is set to an integral multiple of the spiral interval82P of the blade82B in the present exemplary embodiment, but is not limited thereto. For example, the interval69P between the connection portions69may be larger than the spiral interval82P of the blade82B and may be an interval different from the integral multiple of the spiral interval82P of the blade82B.

Moreover, the width69W of the connection portion69in the rotation axis direction of the second transport auger82is set to 1 mm or less in the present exemplary embodiment, but is not limited thereto. For example, the width69W of the connection portion69in the rotation axis direction of the second transport auger82may exceed 1 mm.

In addition, the respective connection portions69may have different shapes, different dimensions, and the like.

The present invention is not limited to the above-mentioned exemplary embodiment and may include various modifications, alterations, or improvements without departing from the scope of the present invention. For example, a plurality of modification examples among the above-mentioned modification examples may be appropriately combined.

A developing device comprising:a storage part in which a developer is stored;a transport body that includes a spiral blade and transports the developer via a rotation thereof;a developing body to which the developer is supplied from the transport body;an attachment part which is disposed between the transport body and the developing body and includes an opening allowing the developer supplied from the transport body to the developing body to pass and to which a sealing member sealing the opening is detachably attached; anda connection portion which extends to cross the opening at a spiral angle of the blade as viewed from the developing body toward the transport body and of which one end portion and the other end portion are connected to the attachment part.

The developing device according to (((1))), wherein a width of the connection portion in a rotation axis direction of the transport body at a downstream end portion of the connection portion in a supply direction from the transport body toward the developing body is less than the width thereof at an upstream end portion of the connection portion.

The developing device according to (((2))), wherein the width of the connection portion in the rotation axis direction of the transport body is gradually reduced in the supply direction.

The developing device according to (((3))), wherein the connection portion is formed at an acute angle in the supply direction.

The developing device according to any one of (((1))) to (((4))), wherein a plurality of connection portions are arranged in the rotation axis direction of the transport body, andan interval between the connection portions in the rotation axis direction is equal to or larger than a spiral interval of the blade.

The developing device according to (((5))), wherein an interval between the connection portions in the rotation axis direction is an integral multiple of the spiral interval of the blade.

The developing device according to any one of (((1))) to (((6))), wherein the width of the connection portion in the rotation axis direction of the transport body is 1 mm or less.

An image forming apparatus comprising:a holding body that holds a latent image; andthe developing device according to any one of (((1))) to (((7))) that develops the latent image.