Developing device and image forming system

Abstract

A developing device includes: a housing that accommodates a developer and is open to face an image holding body capable of holding a latent image; a developing member rotatably provided in the housing, exposed from the opening, capable of holding the developer on the outer periphery, and developing the latent image with the developer held while rotating; and a cover member that covers a gap between the developing member and the housing on a downstream side of a developing position in a rotation direction of the developing member, the cover covers a first region corresponding to one end portion of the developing member in the rotational axis direction and does not cover at least a portion of an intermediate region corresponding to a space between both end portions of the developing member in the rotational axis direction.

Description

TECHNICAL FIELD

[0001] The present application relates to a developing device and an image forming system. BACKGROUND

[0002] A developing device is disclosed in Patent Literature 1. The developing device is provided with a developing container, a developer carrier, a restriction portion, an opposing portion, a seal portion, and a seal member. The developing container accommodates a developer containing toner and a carrier. The developer carrier is a rotatable developer carrier that carries and transports the developer toward a developing position at which an electrostatic latent image formed on an image carrier is developed. The developer carrier has a carrying region and a non-carrying region. The carrying region is a region of the developer carrier that has a developer transporting capability. The non-carrying region is a region of the developer carrier that has no developer transporting capability. The restriction portion restricts the amount of the developer carried on the carrying region. The opposing portion is disposed in opposition to the developer carrier with respect to the direction of rotation of the developer carrier, downstream of the restriction portion and upstream of the developing position. The seal portion is flexible and disposed in opposition to the carrying region and the non-carrying region in contact with the developer carried on the carrying region. The seal member is disposed in the seal portion in a manner of being interposed between the seal portion and the non-carrying region.

[0003] A developing device is disclosed in Patent Literature 2. The developing device is provided with a developer carrier, a developer supply member, a housing, and an agitating member. The developer carrier transports a developer to an image carrier. The developer supply member supplies the developer to the developer carrier. The housing accommodates the developer. The agitating member agitates the developer in the housing while supplying the developer to the developer supply member by a rotational action. Further, the developer carrier is provided with a first electrode and a second electrode disposed to the first electrode via an insulator. In the developing device, the developer on the developer carrier is fogged by applying a voltage that reverses the potential difference between the first electrode and the second electrode in time. Further, an electrostatic latent image formed on the image carrier is developed by transporting the developer to a developing region by the surface movement of the developer carrier. The developer remaining on the developed developer carrier enters into the device through an opening between the developer carrier and an opening portion member disposed in a manner of forming a constant gap with the developer carrier after the developer is recovered by the developer supply member. Further, the developing device is provided with an abutting member that abuts against the developer supply member to close the gap that communicates with the opening due to the gap between the developer supply member and the housing in a manner of being able to prevent the leakage of the developer to the outside of the device.

[0004] In Patent Literature 3, there is disclosed an image developing device. The image developing device includes a developing frame, a developer holding body, a layer thickness limiting member, and a sealing member. The developing frame is opened to face a latent image holding body that holds a latent image inside. The developer holding body is disposed to face the opening of the developing frame. The developer holding body holds and transports a developer while rotating to face the latent image holding body. The layer thickness limiting member is disposed in an upstream side gap in a gap formed by the developer holding body and the developing frame on an upstream side of the opening in a rotation direction of the developer holding body. The layer thickness limiting member limits a layer thickness of the developer on the developer holding body. The sealing member is disposed in a downstream side gap in the gap formed by the developer holding body and the developing frame on a downstream side of the opening in the rotation direction of the developer holding body. The sealing member is composed of a plate material that extends in a long strip shape along a rotation axis direction of the developer holding body and has flexibility. Also, with respect to the sealing member, an upstream side in a width direction along the rotation direction of the developer holding body is fixed to the developing frame, and a downstream side in the width direction is in contact with the developer on the developer holding body, thereby sealing the downstream side gap. Also, the sealing member has a plurality of notches with respect to the rotation axis direction of the developer holding body, the notches are more than 60% from a free end side to a fixed end in a size of the free end to the fixed end in the width direction, and an angle formed by a reference line along the rotation direction of the developer holding body is less than or equal to 30°.

[0005] Patent Literature 1: Japanese Patent Application Publication No. 2023-013157

[0006] Patent Literature 2: Japanese Patent Application Publication No. 2013-200379

[0007] Patent Literature 3: Japanese Patent Application Publication No. 2016-180829 SUMMARY

[0008] An object of the present application is to suppress an increase in internal pressure of a frame compared to a structure in which a covering member covers an entire area of a gap formed by a developing member and the frame.

[0009] The image developing device of the first aspect of the present application includes a frame that holds a developer and is opened to face a latent image holding body that holds a latent image; a developing member that is rotatably disposed in the frame, is exposed from the opening, can hold the developer on an outer periphery, and develops the latent image using the developer held while rotating; and a covering member that covers a gap between the developing member and the frame on a downstream side of a developing position in a rotation direction of the developing member, and in the gap, covers a first area corresponding to one end portion in a rotation axis direction of the developing member and does not cover at least a part of an intermediate area corresponding to between both end portions in the rotation axis direction of the developing member.

[0010] The developing device of the second aspect of the present application is the developing device of the first aspect, wherein the cover member covers a second region corresponding to the other end portion of the developing member in the direction of the rotation axis of the developing member in the gap.

[0011] The developing device of the third aspect of the present application is the developing device of the second aspect, wherein the first region and the second region of the gap are respectively covered by a pair of the cover members.

[0012] The developing device of the fourth aspect of the present application is the developing device of the first aspect, wherein the developer is supplied in the developing member from one end portion toward the other end portion of the developing member in the frame in the direction of the rotation axis of the developing member.

[0013] The developing device of the fifth aspect of the present application is the developing device of any one of the first to fourth aspects, wherein, in the gap, a region not covered by the cover member is a region of the developing member having a length of 1 / 3 or more of a length of a region holding the developer in the direction of the rotation axis.

[0014] The developing device of the sixth aspect of the present application is the developing device of any one of the first to fifth aspects, wherein the cover member extends from the frame toward the developing member in a normal direction of the developing member.

[0015] The developing device of the seventh aspect of the present application is the developing device of any one of the first to sixth aspects, wherein the cover member extends from the frame toward the developing member, a base end portion of the cover member fixed to the frame is located on the image holding body side, and a front end portion of the cover member is located on the rotation center side of the developing member.

[0016] The developing device of the eighth aspect of the present application is the developing device of any one of the first to seventh aspects, further comprising: a seal member extending in a tangential direction of the developing member and sealing an end portion of the developing member in the direction of the rotation axis and the frame; and a fixing member fixing the seal member and the cover member to the frame.

[0017] The developing device of the ninth aspect of the present application is the developing device of the fourth aspect, wherein a through hole for pressure reduction is provided in the frame in a portion corresponding to the other end portion of the developing member in the direction of the rotation axis.

[0018] The image forming system of the tenth aspect of the present application includes: an image holding body capable of holding a latent image; and the developing device of any one of the first to ninth aspects disposed around the image holding body and developing the latent image with a developer.

[0019] Effects of the Invention

[0020] In the developing apparatus of the first embodiment, compared with a structure that uses a covering member to cover the entire area of ​​the gap formed by the developing member and the frame, the rise of internal pressure in the frame can be suppressed.

[0021] In the developing apparatus of the second embodiment, compared with the structure in which a covering member is used to cover only the first region corresponding to one end of the developing member in the direction of rotation axis, leakage of developer can be suppressed.

[0022] In the developing apparatus of the third scheme, compared with the structure that uses a cover member to cover the first and second regions of the gap, it is easier to adjust the position of the cover member relative to the gap.

[0023] In the developing apparatus of the fourth embodiment, compared with the structure in which the covering member covers only the area corresponding to the other end in the direction of rotation axis of the developing member in the gap, the leakage of developer can be suppressed.

[0024] In the developing apparatus of the fifth scheme, compared with a structure in which the area not covered by the covering member in the gap is less than 1 / 3 of the length of the holding area of ​​the developing member along the rotation axis, the rise of the internal pressure of the frame can be suppressed.

[0025] In the developing apparatus of the sixth embodiment, compared with the structure in which the cover member extends from the frame toward the developing member along the tangential direction of the developing member, the length from the base end to the front end of the cover member can be shortened.

[0026] In the developing apparatus of the seventh embodiment, compared with the structure in which the front end of the cover member is located upstream of the developing member in the direction of rotation of the base member, the lifting of the cover member that accompanies the rise of the internal pressure of the frame can be suppressed.

[0027] In the developing apparatus of the eighth scheme, the fixing operation of the sealing component and the covering component relative to the frame becomes simpler compared to the structure in which the sealing component and the covering component are fixed to the frame separately.

[0028] In the developing apparatus of the ninth embodiment, compared with the structure in which a pressure-reducing through hole is provided in the part of the frame corresponding to one end in the direction of rotation of the developing component, leakage of developer can be suppressed.

[0029] In the image forming system of the 10th scheme, compared with the structure of the developing device that uses a covering component to cover the entire area of ​​the gap formed by the developing component and the frame, it is possible to suppress the rise of the internal pressure of the developing device frame. Attached Figure Description

[0030] The embodiments of the present invention will be described in detail with reference to the following figures.

[0031] Figure 1This is a schematic diagram showing the image forming apparatus according to this embodiment;

[0032] Figure 2 yes Figure 1 The side sectional view of the developing apparatus shown;

[0033] Figure 3 Viewed from the side of the opening Figure 2 The front view of the developing apparatus shown;

[0034] Figure 4 yes Figure 3 The 4-4 line sectional view shown;

[0035] Figure 5 This is an enlarged view of the main parts of the developing apparatus according to this embodiment. Figure 2 (A magnified view of a portion of the image);

[0036] Figure 6 This is an enlarged view of the main parts of the developing apparatus according to this embodiment. Figure 4 (A magnified view of a portion of the image);

[0037] Figure 7 This is an enlarged view of the main parts of the developing apparatus according to this embodiment (enlarged view of the open area);

[0038] Figure 8 This is a front view of the developing apparatus involved in other embodiments, viewed from the opening side;

[0039] Figure 9 This is a front view of the developing apparatus involved in other embodiments, viewed from the opening side;

[0040] Figure 10 yes Figure 9 The sectional view shown is along line 10-10. Detailed Implementation

[0041] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0042] (Image forming apparatus 10)

[0043] The structure of the image forming apparatus 10, which uses the image forming system described in this embodiment, will be explained. Figure 1 This is a schematic diagram showing the structure of the image forming apparatus 10 according to this embodiment.

[0044] Additionally, the arrow UP in the diagram indicates the top of the device (specifically, vertically above), and the arrow DO indicates the bottom of the device (specifically, vertically below). Furthermore, the arrow LH indicates the left side of the device, and the arrow RH indicates the right side. Also, the arrow FR indicates the front of the device, and the arrow RR indicates the rear. These directions are provided for ease of explanation, and the device structure is not limited to these directions. Furthermore, the term "device" is sometimes omitted when indicating different directions. That is, for example, "above the device" is sometimes simply referred to as "above".

[0045] Furthermore, in the following description, "up / down direction" is sometimes used to mean "both above and below" or "either above or below". "Left / right direction" is sometimes used to mean "both right and left" or "either right or left". Additionally, "left / right direction" can also refer to the side, lateral, and horizontal directions. "Front / back direction" is sometimes used to mean "both front and back" or "either front or back". Additionally, "front / back direction" can also refer to the side, lateral, and horizontal directions. Furthermore, the up / down, left / right, and front / back directions are intersecting directions (specifically, orthogonal directions).

[0046] Furthermore, the "×" mark within the "○" in the diagram indicates an arrow pointing from the front of the paper towards the inside. Also, the "·" mark within the "○" in the diagram indicates an arrow pointing from the inside of the paper towards the front.

[0047] Figure 1 The image forming apparatus 10 shown is an image forming apparatus. Specifically, as... Figure 1 As shown, the image forming apparatus 10 includes a media receiving unit 12, a transmission unit 13, and an image forming unit 14. The following describes each part of the image forming apparatus 10.

[0048] (Media Accommodation Department 12)

[0049] The media receiving section 12 is the portion of the image forming apparatus 10 that houses the recording medium P. The recording medium P housed in the media receiving section 12 is supplied to the image forming section 14. The recording medium P housed in the media receiving section 12 is the object from which an image is formed by the image forming section 14. Examples of recording media P include paper and film. Examples of films include resin films and metal films. Furthermore, the recording medium P is not limited to the aforementioned recording media; various recording media can be used.

[0050] (Teleportation Department 13)

[0051] Figure 1The conveying unit 13 shown conveys the recording medium P contained in the media receiving unit 12 to the discharge unit (not shown). Specifically, as... Figure 1 As shown, the conveying unit 13 has a plurality of conveying components 13A, such as conveyor rollers, which convey the recording medium P. Furthermore, the conveying components 13A can be, for example, conveyor belts or conveyor rollers; various conveying components can be used.

[0052] (Image forming unit 14)

[0053] Figure 1 The image forming unit 14 shown forms an image on the recording medium P, which is transported by the transport unit 13 (specifically, the transport member 13A). Specifically, in the image forming unit 14, a toner image (an example of an image) is formed on the recording medium P by an electrophotographic system. More specifically, as... Figure 1 As shown, the image forming unit 14 includes tonal image forming units 20Y, 20M, 20C, and 20K (hereinafter referred to as 20Y to 20K), a transfer body 24, and a fixing unit 26.

[0054] Each of the toning agent image forming sections 20Y to 20K has a photoreceptor 32. Furthermore, since the toning agent image forming sections 20Y to 20K are constructed in the same manner, therefore... Figure 1 The symbols for each part in the toning agent image forming section 20Y, 20M, and 20C are omitted.

[0055] The photoreceptor 32 is an example of an image retainer, a structure that retains a latent image. Specifically, the photoreceptor 32 is oriented in one direction (e.g., Figure 1 (In the counterclockwise direction) rotating. Around the photoreceptor 32, a charging device 34, an exposure device 36, and a developing device 38 are arranged sequentially upstream of the rotation direction of the photoreceptor 32.

[0056] In the tonal image forming sections 20Y to 20K, the charging device 34 charges the photoreceptor 32 (charging process). Furthermore, the exposure device 36 exposes the photoreceptor 32, which has been charged by the charging device 34, to form a latent image (specifically, an electrostatic latent image) on the photoreceptor 32 (exposure process). The photoreceptor 32 retains the latent image formed by the exposure device 36.

[0057] Furthermore, the developing apparatus 38 develops the latent image held by the photoreceptor 32 (developing process). Thus, a toner image is formed on the photoreceptor 32. The specific structure of the developing apparatus 38 will be described later.

[0058] In the image forming unit 14, the tonal image forming units 20Y to 20K perform charging, exposure, and development processes respectively, forming tonal images of yellow (Y), magenta (M), cyan (C), and black (K) on the transfer body 24. Furthermore, in the image forming unit 14, the tonal images of each color formed on the transfer body 24 are transferred onto the recording medium P, and the tonal images are fixed onto the recording medium P by the fixing unit 26. Thus, in the image forming unit 14, an intermediate transfer method is used to transfer the image onto the recording medium P via the transfer body 24.

[0059] Furthermore, the image forming unit is not limited to intermediate transfer methods. For example, a direct transfer method that directly transfers the image to the recording medium P can be used, and various image forming units can be applied.

[0060] (Developing apparatus 38)

[0061] As mentioned above, Figure 2 , Figure 3 and Figure 4 The developing apparatus 38 shown is an apparatus for developing the latent image held by the photoreceptor 32 using a developing agent. Furthermore, the developing agent is a developing agent containing a toner and a magnetic carrier. Specifically, such as... Figure 2 As shown, the developing apparatus 38 includes a frame 60, a developing roller 80, and a cover film 90. The following describes each part of the developing apparatus 38.

[0062] (Frame 60)

[0063] Figure 2 and Figure 4 The frame 60 shown has the function of containing developer inside. For example... Figure 2 As shown, with the developing apparatus 38 respectively installed in the toner image forming sections 20Y to 20K, the frame 60 has an opening 64 that opens toward the photoreceptor 32 side (specifically, the left side). In other words, the frame 60 has an opening 64 that faces the photoreceptor 32 side.

[0064] like Figure 2 and Figure 3 As shown, a developing roller 80, which supplies developer to the photoreceptor 32 with a portion exposed from the opening 64, is disposed within the frame 60. A layer-restricting member 84 is provided on the lower side of the developing roller 80. Additionally, in Figure 2 The image shows the photoreceptor 32 with the developing device 38 installed in the toner image forming section 20Y to 20K, illustrated with a double-dotted line.

[0065] Furthermore, the frame 60 includes a receiving portion 63 for receiving developer supplied from a supply device (not shown). This receiving portion 63 has a transport path for conveying the developer supplied from the supply device. In this embodiment, as an example, the transport path includes a supply path 61 and a stirring path 62.

[0066] The supply path 61 is arranged along the front-to-back direction on the side below the developing roller 80. Specifically, the supply path 61 is arranged along the front-to-back direction on the right-lower side relative to the developing roller 80. The supply path 61 contains the developer supplied to the developing roller 80. Furthermore, the developer within the supply path 61 is conveyed in the transport direction (specifically, one of the front-to-back direction). Specifically, a transport screw conveyor 81, as a transport component, is arranged in the supply path 61. Through the rotation of the transport screw conveyor 81, the developer is conveyed in the transport direction (specifically, one of the front-to-back direction) within the supply path 61.

[0067] The stirring path 62 is arranged adjacent to the supply path 61. Specifically, the stirring path 62 is arranged in a front-to-back direction on the right side relative to the supply path 61. The stirring path 62 is connected to each of the front and rear ends of the supply path 61 at its front and rear ends, respectively. A circulation path is formed by the supply path 61 and the stirring path 62.

[0068] The stirring path 62 contains the developer supplied from the aforementioned supply device as developer supplied to the supply path 61. The supplied developer is conveyed in the opposite direction to the aforementioned conveying direction (specifically, the other direction between forward and backward). Specifically, a conveying screw conveyor 82, as a conveying component, is disposed in the stirring path 62. By rotating the conveying screw conveyor 82, the developer is stirred and conveyed in the stirring path 62 in the opposite direction to the conveying direction (specifically, the other direction between forward and backward).

[0069] (Developing roller 80)

[0070] The developing roller 80 is rotatably disposed within the frame 60. The developing roller 80 is exposed from the opening 64. The developing roller 80 holds the developer on its outer periphery. The developing roller 80 has the function of developing the latent image formed on the photoreceptor 32 while rotating. Specifically, the developing roller 80 is rotatably supported in the frame 60 with the back-and-forth direction as its rotation axis. The developing roller 80 holds the developer on its outer peripheral surface and delivers the developer to the developing position D opposite to the photoreceptor 32. The developing position D, as mentioned here, refers to the position where the developing roller 80 develops the latent image of the photoreceptor 32 using the developer.

[0071] Regarding the developer delivered toward the developing position D, the thickness (developing dose) of the developer layer is limited by the layer limiting member 84. Furthermore, at the developing position D, the developer (specifically, the toning agent) on the developing roller 80 is supplied to the photoreceptor 32, and the latent image (electrostatic latent image) formed on the photoreceptor 32 is developed using the developer (specifically, the toning agent). The developing roller 80 of this embodiment is an example of the developing component of the present invention.

[0072] (Covering membrane 90)

[0073] like Figure 2 , Figure 3 and Figure 4 As shown, the cover film 90 is a component that functions to prevent developer leakage from the housing 60. This cover film 90 is an example of a cover component. Figure 2 As shown, the cover film 90 is positioned further downstream of the developing position D in the rotation direction of the developing roller 80.

[0074] The cover film 90 is a component that covers the gap G between the developing roller 80 and the frame 60. Here, the gap G is a portion of the gap between the developing roller 80 and the frame 60 located downstream of the developing position D in the rotation direction of the developing roller 80. Specifically, as... Figure 2 and Figure 4 As shown, gap G is the gap formed between the ceiling portion 65 of the frame 60 and the developing roller 80. Furthermore, as... Figure 3 As shown, when viewed from the opening 64 side, the covering film 90 covers the gap G.

[0075] like Figure 3 As shown, the cover film 90 covers a first region R1 in the gap G, corresponding to one end 80A in the rotational axis direction of the developing roller 80. Furthermore, the cover film 90 covers a second region R2 in the gap G, corresponding to the other end 80B in the rotational axis direction of the developing roller 80. Specifically, the first region R1 and the second region R2 of the gap G are each covered by a pair of cover films 90. In this embodiment, as an example, one end 80A of the developing roller 80 is located on the front side in the front-rear direction. That is, one end 80A of the developing roller 80 can also be referred to as the front end. However, this structure is not limited; one end 80A of the developing roller 80 can also be located on the rear side in the front-rear direction. Furthermore, the other end 80B in the rotational axis direction of the developing roller 80 refers to the end on the side opposite to one end 80A in the rotational axis direction. Therefore, the two ends in the rotational axis direction of the developing roller 80 refer to one end 80A and the other end 80B of the developing roller 80.

[0076] The developing roller 80 is configured to include one end 80A, another end 80B, and an intermediate portion 80C located between the two ends in the direction of rotation axis. Furthermore, the end of the developing roller 80 in the direction of rotation axis refers to a portion extending from its end face in the direction of rotation axis, for example, 5% to 20% of the roller length. Here, roller length refers to the length of the roller portion of the developing roller 80 along the direction of rotation axis. The intermediate portion 80C of the developing roller 80 refers to the portion between the two ends in the direction of rotation axis.

[0077] like Figure 3 As shown, the cover film 90 is configured not to cover at least a portion of the intermediate region RM corresponding to the middle portion 80C of the developing roller 80 in the gap G. Specifically, the gap G is configured to include a first region R1, a second region R2, and an intermediate region RM. Here, for example, the first region R1 of the gap G is covered by one cover film 90. The second region R2 of the gap G is covered by another cover film 90. Furthermore, the portion between the pair of cover films 90 in the intermediate region RM of the gap G is not covered. That is, the portion between the pair of cover films 90 in the intermediate region RM of the gap G is open. Pressure can be applied to the frame 60 through this open area.

[0078] Furthermore, in the gap G, the area corresponding to each part in the rotation axis direction of the developing roller 80 refers to the area of ​​each part in the direction orthogonal to the rotation axis direction.

[0079] One of the covering films 90 can cover not only the first region R1 of the gap G, but also a portion of the intermediate region RM adjacent to the first region R1. The other covering film 90 can cover not only the second region R2 of the gap G, but also a portion of the intermediate region RM adjacent to the second region R2.

[0080] In the developing roller 80, developer is supplied from one end 80A to the other end 80B within the housing 60. Specifically, developer is supplied to the developing roller 80 via the supply path 61. In this embodiment, as an example, developer is conveyed from the front side to the rear side of the supply path 61. Therefore, in the developing roller 80, developer is supplied from one end 80A to the other end 80B via the supply path 61.

[0081] like Figure 3As shown, in the gap G, an area not covered by a pair of cover films 90 is formed in the middle region RM. This uncovered area refers to the aforementioned open area of ​​the gap G (hereinafter simply referred to as the open area RO). The open area RO is preferably, for example, set to be at least 1 / 3 of the length of the developer-holding area HR of the developing roller 80 along the rotation axis direction. In addition, the outer periphery of the developing roller 80 in this embodiment is configured to include the developer-holding area HR and the non-retaining area NHR. The non-retaining areas NHR are formed at the ends of the roller in the rotation axis direction. The holding area HR is formed between the non-retaining areas NHR on both sides of the roller in the rotation axis direction.

[0082] And, as Figure 3 As shown, in this embodiment, the end of the developing roller 80 in the direction of rotation includes a portion of the holding region HR adjacent to the non-holding region NHR. Therefore, in the gap G, the non-holding region NHR and a portion of the holding region HR of the developing roller 80 are covered by the cover film 90.

[0083] The cover film 90 is fixed to the fixing part 66, which is located on the ceiling portion 65 of the frame 60, further downstream of the developing position D in the rotation direction of the developing roller 80. The fixing part 66 is inclined toward the developing roller 80. Specifically, the fixing part 66 is inclined diagonally downward to the right toward the developing roller 80. The base end portion 90A of the cover film 90 is fixed to the fixing part 66. The front end portion 90B of the cover film 90 is a free end. The front end portion 90B of the cover film 90 is disposed near the outer peripheral surface of the developing roller 80. Specifically, the front end portion 90B of the cover film 90 is configured to contact the developer held by the developing roller 80. In addition, the front end portion 90B of the cover film 90 can contact the outer peripheral surface of the developing roller 80. Furthermore, as a method of fixing the cover film 90 to the fixing part 66, adhesive or bonding can be used, for example. As an example of adhesive, bonding using adhesive or adhesive tape can be used. And as an example of bonding, bonding using threaded material can be used. Furthermore, the method of fixing the covering film 90 to the fixing part 66 is not limited to the above.

[0084] The cover film 90 can extend from the frame 60 toward the developing roller 80 along the normal direction ND of the developing roller 80. Here, the cover film 90 extends along the normal direction ND, for example, including cases where the cover film 90 is inclined at less than 10 degrees relative to the normal direction ND. Specifically, as... Figure 5As shown, the cover film 90 can also extend such that the angle θ formed by the center line CL of the cover film 90 and the normal NL on the outer peripheral surface of the developing roller 80 is 0 degrees or more and 10 degrees or less. Here, the center line CL of the cover film 90 is a straight line passing through the center of the cover film 90 in the thickness direction. The normal NL on the outer peripheral surface of the developing roller 80 is the normal at the intersection of the extension of the center line CL and the outer peripheral surface of the developing roller 80. In addition, the normal direction ND is the direction along the normal NL.

[0085] In the 90 types of covering membrane, such as Figure 5 As shown, the base end 90A fixed to the frame 60 is located on the side of the photosensitive element 32, and the front end 90B is located on the rotation center side of the developing roller 80.

[0086] As an example, the cover film 90 can be formed from a resin film. For example, polyethylene terephthalate (PET) can be used as the resin for forming the cover film 90.

[0087] And, as Figure 3 and Figure 4 As shown, the developing apparatus 38 may include a side seal 100 extending along the tangential direction TD of the developing roller 80. In this embodiment, as an example, the tangential direction TD refers to the direction along the tangent TL at the developing position D. The side seal 100 is an example of a sealing member that seals the end of the developing roller 80 in the direction of its rotation axis with the frame 60. Both end sides of the developing roller 80 in the direction of its rotation axis are sealed by a pair of side seals 100. Furthermore, the side seal 100 extends along the tangential direction TD, for example, including cases where the side seal 100 is inclined at a degree or less relative to the tangential direction TD. Specifically, the upper end portion 100A of the side seal 100 is fixed to the wall portion 68 connecting the fixing portion 66 of the frame 60 and the opening portion 64. The side seal 100 extends from the wall portion 68 toward the developing roller 80. More specifically, the side seal 100 extends from the wall portion 68 toward the developing roller 80 in a manner that it contacts the developing roller 80. In this embodiment, as an example, the side seal 100 extends linearly from the wall portion 68 toward the developing roller 80 and contacts the outer periphery of the developing roller 80. That is, as shown... Figure 6 As shown, the side seal 100 extends from the wall portion 68 along the tangential direction TD of the developing roller 80. Additionally, the side seal 100 extends in a curved shape from the wall portion 68 and contacts the outer periphery of the developing roller 80. The lower end portion 100B of the side seal 100 is fixed to the inner wall of the frame 60 located upstream of the developing position D.

[0088] As an example, the side seal 100 in this embodiment is made of a thin film material. The same material as the cover film 90 can be used as the thin film material.

[0089] Next, the function of this embodiment will be explained.

[0090] In the developing apparatus 38 of this embodiment, in the gap G, in the regions corresponding to the two ends in the direction of the rotation axis of the developing roller 80, the developer circulates in the transport path, and therefore tends to leak more easily than in the middle region RM. Therefore, in the developing apparatus 38 of this embodiment, a cover film 90 is used to cover the first region R1 of the gap G. In the developing apparatus 38, the cover film 90 suppresses developer leakage from the first region R1 of the gap G.

[0091] In the developing apparatus 38 of this embodiment, the gap G is provided as an open area RO that does not cover at least a portion of the intermediate area RM. By providing the open area RO in this way, even if the internal pressure of the housing 60 begins to rise due to the operation of the developing apparatus 38, the fluid (gas) will escape from the open area RO (see reference). Figure 7 Therefore, in the developing apparatus 38 of this embodiment, compared with a structure that uses a cover film 90 to cover the entire area of ​​the gap G, the internal pressure rise of the frame 60 can be suppressed because it has an open area RO for pressure reduction.

[0092] In this embodiment, the developing apparatus 38 covers the second region R2 of the gap G with a cover film 90. Therefore, in the developing apparatus 38, leakage of developer from the second region R2 of the gap G can be suppressed by the cover film 90. That is, in the developing apparatus 38, compared with a structure that only covers the first region R1 with the cover film 90, developer leakage can be suppressed.

[0093] The developing apparatus 38 of this embodiment comprises a first region R1 and a second region R2 of a gap G covered by a pair of cover films 90. In the developing apparatus 38 of this embodiment, compared to a structure where the first region R1 and the second region R2 of the gap G are covered by a single cover film 90, the position of the cover film 90 is easier to adjust relative to the gap G. Furthermore, the amount of material used in the cover film 90 can be reduced.

[0094] In the developing apparatus 38 of this embodiment, developer is supplied from one end 80A to the other end 80B in the rotation axis direction of the developing roller 80 within the frame 60. Specifically, upstream of the developer supply direction, the developer charge is low, making it prone to being dispersed as dust. Therefore, when developer is supplied from one end 80A to the other end 80B within the frame 60, a cover film 90 is used to cover the first region R1 corresponding to one end 80A in the gap G. This suppresses developer leakage compared to a structure where the cover film 90 only covers the second region R2 of the developing roller 80 in the gap G.

[0095] In the developing apparatus 38 of this embodiment, the area in the gap G not covered by the covering film 90 is set to be at least 1 / 3 of the length of the holding area HR of the developing roller 80. Specifically, the open area RO in the gap G is set to be at least 1 / 3 of the length. Therefore, in the developing apparatus 38 of this embodiment, compared with a structure in which the open area RO in the gap G is less than 1 / 3 of the length, the rise of internal pressure in the frame 60 can be suppressed.

[0096] In the developing apparatus 38 of this embodiment, the cover film 90 extends from the frame 60 toward the developing roller 80 along the normal direction ND of the developing roller 80. Therefore, in the developing apparatus 38 of this embodiment, compared with a structure in which the cover film 90 extends along the tangential direction of the developing roller 80, the length from the base end 90A to the front end 90B of the cover film 90 can be shortened.

[0097] In the developing apparatus 38 of this embodiment, the front end portion 90B of the cover film 90 is located downstream of the developing roller 80 in the rotational direction compared to the base end portion 90A. Therefore, in the developing apparatus 38 described above, compared to a structure where the front end portion 90B of the cover film 90 is located upstream of the developing roller 80 in the rotational direction compared to the base end portion 90A, it is possible to suppress the lifting of the cover film 90 that accompanies the increase in internal pressure of the frame 60.

[0098] (Other implementation methods)

[0099] In the aforementioned embodiment, in the developing roller 80, developer is supplied from one end 80A to the other end 80B within the frame 60, but the present invention is not limited to this structure. In the developing roller 80, developer can also be supplied from the other end 80B to one end 80A within the frame 60. Furthermore, in the aforementioned embodiment, the cover film 90 covers both the first region R1 and the second region R2 of the gap G, but the present invention is not limited to this structure. The cover film 90 may only cover the first region R1.

[0100] In the aforementioned embodiment, a pair of covering films 90 are fixed to the frame 60 to cover the first region R1 and the second region R2, but the present invention is not limited to this structure. For example, an open region RO can be formed by cutting a portion of a strip of covering film corresponding to the middle region RM of the gap G. Alternatively, an open region RO can be formed by adding a plurality of slits. Furthermore, an open region RO can also be formed by providing one or more through holes in the portion of the covering film corresponding to the middle region RM of the gap G.

[0101] Furthermore, in the aforementioned embodiments, the intermediate region RM and the open region RO have the same size, but the present invention is not limited to this structure. For example, as Figure 8 As shown, a portion of the intermediate area RM can be covered using the covering film 91.

[0102] In the foregoing embodiments, the covering film 90 and the side seal 100 are fixed to different parts of the frame 60, but the present invention is not limited to this structure. For example, as Figure 9 and Figure 10 As shown, the structure can be configured such that the cover film 90 and the side seal 100 are fixed to the frame 60 via the fixing member 110. Specifically, the structure can be configured such that the cover film 90 and the side seal 100 are fixed to the fixing member 110, and the fixing member 110 is fixed to the frame 60. By configuring this structure, compared to a structure where the cover film 90 and the side seal 100 are fixed to the frame 60 separately, the fixing operation of the side seal 100 and the cover film 90 relative to the frame 60 can be simplified. Furthermore, the fixing of the cover film 90 and the side seal 100 relative to the fixing member 110 can be either adhesive or connection. Also, the fixing of the fixing member 110 to the frame 60 can be either adhesive or connection.

[0103] In the aforementioned embodiment, no pressure-reducing through-hole is provided in the frame 60, but the present invention is not limited to this structure. For example, a pressure-reducing through-hole may be provided in the portion of the frame 60 corresponding to the other end 80B of the developing roller 80. Around the portion where the pressure-reducing through-hole is provided, the tendency for internal pressure rise within the frame 60 is suppressed. Therefore, when the frame 60 is provided with a pressure-reducing through-hole, for example, a cover film 90 may be provided on the side opposite to the side where the pressure-reducing through-hole is provided. In this case, compared to the structure in which a pressure-reducing through-hole is provided in the frame 60 at the portion corresponding to one end 80A of the developing roller 80, developer leakage from the gap G can be suppressed.

[0104] This invention is not limited to the embodiments described above, and various modifications, alterations, and improvements can be made without departing from its spirit. For example, the modifications shown above can be appropriately combined in multiple ways to form a complete system.

[0105] (Postscript) (((1)))

[0107] A developing apparatus comprising:

[0108] The frame contains the developer and has an opening opposite to the image holder that can hold the latent image;

[0109] A developing component, rotatably disposed within the frame and exposed from the opening, is capable of holding the developer at its outer periphery and developing the latent image using the developer held while rotating; and

[0110] A covering member that covers the gap between the developing member and the frame on the downstream side of the developing position in the rotation direction of the developing member, and in the gap, covers a first region corresponding to one end of the developing member in the rotation axis direction and does not cover at least a portion of the intermediate region corresponding to the two ends of the developing member in the rotation axis direction. (((2)))

[0112] According to the developing apparatus described in ((1)), wherein,

[0113] The covering component covers a second region in the gap that corresponds to the other end of the developing component in the direction of its rotation axis. (((3)))

[0115] According to the developing apparatus described in ((2)), wherein,

[0116] The first and second regions of the gap are respectively covered by a pair of the covering components. (((4)))

[0118] According to the developing apparatus described in ((1)), wherein,

[0119] In the developing unit, the developing agent is supplied from one end toward the other end in the direction of the rotation axis of the developing unit within the frame. (((5)))

[0121] The developing apparatus according to any one of ((1))) to ((4))) wherein,

[0122] In the gap, the area not covered by the covering member is more than 1 / 3 of the length of the region of the developing member that holds the developer along the direction of the rotation axis. (((6)))

[0124] The developing apparatus according to any one of ((1))) to ((5))) wherein,

[0125] The covering component extends from the frame toward the developing component along the normal direction of the developing component. (((7)))

[0127] The developing apparatus according to any one of ((1))) to ((6))) wherein,

[0128] The cover member extends from the frame toward the developing member, with its base end fixed to the frame located on the image holder side and its front end located on the rotation center side of the developing member. (((8)))

[0130] The developing apparatus according to any one of ((1))) to ((7))) further comprises:

[0131] A sealing member extends tangentially to the developing member and seals the end of the developing member in the direction of its rotation axis and the frame; and

[0132] A fixing component is used to fix the sealing component and the covering component to the frame. ((9)))

[0134] According to the developing apparatus described in ((4)), wherein,

[0135] In the frame, a pressure-reducing through hole is provided at the other end corresponding to the rotation axis of the developing component. (((10)))

[0137] An image forming system comprising:

[0138] Like a latent body, capable of preserving a latent image; and

[0139] The developing apparatus described in any one of ((1))) to ((9))) is arranged around the image holder and develops the latent image using a developing agent.

[0140] In the developing apparatus of (((1))), compared with the structure in which the entire area of ​​the gap formed by the developing component and the frame is covered by a covering component, the rise of the internal pressure of the frame can be suppressed.

[0141] In the developing apparatus of (((2))), compared with the structure in which the covering member covers only the first region corresponding to one end of the developing member in the direction of rotation axis, the leakage of developer can be suppressed.

[0142] In the developing apparatus of ((3)), compared with the structure that uses a cover member to cover the first and second regions of the gap, it is easier to adjust the position of the cover member relative to the gap.

[0143] In the developing apparatus of ((4)), compared with the structure in which the covering member covers only the area corresponding to the other end in the direction of rotation axis of the developing member in the gap, the leakage of developer can be suppressed.

[0144] In the developing apparatus of ((5)), compared with the structure in which the area not covered by the covering member in the gap is less than 1 / 3 of the length of the holding area of ​​the developing member along the rotation axis, the rise of the internal pressure of the frame can be suppressed.

[0145] In the developing apparatus of ((6)), compared with the structure in which the cover member extends from the frame toward the developing member along the tangential direction of the developing member, the length from the base end to the front end of the cover member can be shortened.

[0146] In the developing apparatus of ((7)), compared with the structure in which the front end of the cover member is located upstream of the developing member in the direction of rotation of the base member, it is possible to suppress the lifting of the cover member that accompanies the rise of the internal pressure of the frame.

[0147] In the developing apparatus of ((8)), the fixing operation of the sealing component and the covering component relative to the frame becomes simpler compared to the structure in which the sealing component and the covering component are fixed to the frame respectively.

[0148] In the developing apparatus of ((9)), compared with the structure in which a pressure-reducing through hole is provided in the part of the frame corresponding to one end in the direction of rotation of the developing component, the leakage of developer can be suppressed.

[0149] In the image forming system of ((10)), compared with the structure of the developing device that uses a covering component to cover the entire area of ​​the gap formed by the developing component and the frame, it is possible to suppress the rise of the internal pressure of the developing device frame.

[0150] The embodiments of the present invention described above are provided for illustrative purposes. Furthermore, these embodiments do not encompass the entirety of the invention, nor do they limit the invention to the disclosed methods. It will be apparent to those skilled in the art that various modifications and variations will be readily understood. These embodiments were chosen and described to most readily explain the principles and applications of the invention. Thus, those skilled in the art can understand the invention through various modifications that are assumed to be optimized for specific uses of various embodiments. The scope of the invention is defined by the foregoing claims and their equivalents.

[0151] Explanation of reference numerals in the attached figures

[0152] 10-Image forming apparatus, 12-Media receiving section, 13-Transfer section, 13A-Transfer component, 14-Image forming section, 20-Toner image forming section, 24-Transfer body, 26-Fixing section, 32-Photosensitive body, 34-Charging device, 36-Exposure device, 38-Developing device, 60-Frame, 61-Supply path, 62-Stirring path, 63-Receiving section, 64-Opening section, 65-Ceiling section, 66-Fixing section, 68-Wall section, 80-Developing roller, 80A-One end, 80B-The other end, 80C-Intermediate section, 81-Transfer 82 - Conveyor spiral conveyor; 84 - Layer limiting component; 90 - Cover film; 90A - Base end; 90B - Front end; 91 - Cover film; 100 - Side seal; 100A - Upper end; 100B - Lower end; 110 - Fixing component; θ - Angle; CL - Centerline; D - Development position; G - Gap; HR - Retention area; ND - Normal direction; NHR - Non-retention area; NL - Normal; P - Recording medium; R1 - First area; R2 - Second area; RM - Middle area; RO - Open area; TD - Tangential direction.

Claims

1. A developing device comprising: a frame that accommodates a developer and is open to an image holding body that is capable of holding a latent image; a developing member that is rotatably provided in the frame, is exposed from the opening, is capable of holding the developer to an outer periphery, and develops the latent image using the developer held while rotating; and a cover member that covers a gap between the developing member and the frame on a downstream side of a developing position in a rotation direction of the developing member, and covers a first region corresponding to one end portion in a rotation axis direction of the developing member and does not cover at least a portion of an intermediate region corresponding to between both end portions in the rotation axis direction of the developing member in the gap.

2. The developing device according to claim 1, wherein the cover member covers a second region corresponding to the other end portion in the rotation axis direction of the developing member in the gap.

3. The developing device according to claim 2, wherein the first region and the second region of the gap are respectively covered by a pair of the cover members.

4. The developing device according to claim 1, wherein the developer is supplied in the developing member from one end portion toward the other end portion in the rotation axis direction of the developing member in the frame.

5. The developing device according to any one of claims 1 to 4, wherein a region that is not covered by the cover member in the gap is 1 / 3 or more of a length of a holding region of the developing member that holds the developer along the rotation axis direction.

6. The developing device according to any one of claims 1 to 5, wherein the cover member extends from the frame toward the developing member along a normal direction of the developing member.

7. The developing device according to any one of claims 1 to 6, wherein the cover member extends from the frame toward the developing member, a base end portion fixed to the frame is on an image holding body side, and a front end portion is on a rotation center side of the developing member.

8. The developing device according to any one of claims 1 to 7, further comprising: a seal member that extends along a tangential direction of the developing member and seals an end portion in the rotation axis direction of the developing member and the frame; and a fixing member that fixes the seal member and the cover member to the frame.

9. The developing device according to claim 4, wherein a through-hole for pressure reduction is provided in a portion of the frame corresponding to the other end portion in the rotation axis direction of the developing member.

10. An image forming system comprising: an image holding body that is capable of holding a latent image; and the developing device according to any one of claims 1 to 9, which is disposed around the image holding body and develops the latent image using a developer. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

Images