JP2020170036A - Development device and image formation device - Google Patents

Abstract

To provide a development device and an image formation device which can prevent the cloud of a toner generated by agitation of a developer from being discharged to the outside of the development device.SOLUTION: A development device 40 includes: a development device body 60; a developer carrying member 68a in a first developer carrying path 64a formed in the development device body 60, the developer carrying member carrying a developer by rotating; and sealing means 90 facing the developer carrying member 68a of the development carrying path 62, the sealing means sealing at least the upper part of the first developer carrying path 64a in the gravity direction.SELECTED DRAWING: Figure 3

Description

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

Patent Document 1 describes a developing roll that carries a two-component developer composed of a toner and a magnetic carrier, and a developing roll that is arranged in parallel with the developing roll behind the developing roll and circulates the developer. In a developing apparatus provided with a plurality of developing agent conveying members for conveying a developing agent, it is in a developing agent conveying path provided with a developing agent conveying member other than at least in the vicinity of the developing roll, and further downstream of the toner replenishing unit. A developing apparatus characterized in that a developer transport amount restricting member for restricting the movement of insufficiently charged toner and the developer to the downstream side is provided at a height near the uppermost point of the developer transporting member. Disclose.

Patent Document 2 describes a developer transporting member that agitates with a newly supplied developer containing at least toner while transporting the developer along the axial direction. On the downstream side of the replenishment section of the developer, a first retention section is provided in which the ability to convey the developer in the axial direction is lower than that of other portions and toner is retained, and downstream of the first retention section. Disclosed is a developer transporting member characterized in that a second retaining portion is provided on the side at a predetermined distance.

Japanese Patent Application Laid-Open No. 09-114243 Japanese Unexamined Patent Publication No. 2001-183899

An object of the present invention is to provide a developing apparatus and an image forming apparatus capable of preventing a cloud of toner generated by stirring a developing agent from being discharged to the outside of the developing apparatus.
The toner cloud refers to a phenomenon in which the toner becomes a plume due to the stirring of the developer.

The present invention according to claim 1 includes a developing apparatus main body, a developing agent conveying member provided in a developing agent conveying path formed in the developing apparatus main body and conveying the developer by rotating, and the developer conveying member. It is a developing apparatus provided toward the developer transporting member of the path and having a sealing means for sealing at least the upper part of the developer transport path in the direction of gravity.

The developing apparatus according to claim 1, wherein the sealing means is a magnetic brush composed of a carrier of the developing agent.

According to the third aspect of the present invention, the sealing means is the developing apparatus according to the second aspect, which has a magnet for forming the magnetic brush.

The present invention according to claim 4 is the developing apparatus according to claim 3, wherein the magnet is provided on a protruding wall protruding from the developing apparatus main body toward the developer transport path.

The developing apparatus according to claim 4, wherein the protruding wall is formed obliquely toward the protruding side with respect to the transport direction of the developer transported to the developer transport path. is there.

The present invention according to claim 6 is the developing apparatus according to claim 1, wherein the sealing means is composed of a sealing member projecting from the developing apparatus main body to the developer transport path.

In the present invention according to claim 7, the developer transporting member includes a rotating rotating shaft and a stirring and transporting unit spirally provided on the rotating shaft, and the sealing member is the stirring and transporting unit. The developing apparatus according to claim 6, wherein a part of the above is provided in a notched portion.

According to the eighth aspect of the present invention, the developer transport path includes a first developer transport path for transporting the developer in one direction from the toner supply port and a developer in the opposite direction from the first transport path. It has a second developer transport path for transport, and the toner is circulated between the first developer transport path and the second developer transport path to transport toner, and the sealing means is the first. The developing apparatus according to claim 1, which is provided in the developing agent transport path of 1.

The developing apparatus according to claim 9, wherein the sealing means is provided on the downstream side of the first developer transport path in the toner transport direction.

The developing apparatus according to claim 10, wherein the sealing means is provided on the upstream side and the downstream side in the toner transport direction of the first developer transport path.

According to the eleventh aspect of the present invention, the developer transporting member is provided with a rotating rotary shaft, a stirring and transporting portion spirally provided on the rotating shaft, and a stirring and transporting portion that protrudes in the radial direction of the rotating shaft to stir. The developing apparatus according to claim 10, further comprising a portion, and the stirring portion is arranged between the sealing means on the upstream side and the sealing means on the downstream side.

The present invention according to claim 12 includes an image holder that holds a toner image and a developing device that supplies toner to the image holder, and the developing device includes a developing device main body and the developing device main body. A developer transport member provided in the developer transport path formed inside and transporting the developer by rotation, and a developer transport member provided toward the developer transport member of the developer transport path and described in the developer transport path. It is an image forming apparatus having a sealing means for sealing at least the upper part in the direction of gravity.

The present invention according to claim 13 further includes a developing member provided in the main body of the developing apparatus and facing the image holder, and the developing agent transport path transports the developing agent in one direction from the toner supply port. It has a first developer transport path to be processed and a second developer transport path for transporting the developer in the opposite direction from the first developer transport path and supplying toner to the developing member. 12. The 12th aspect of claim 12, wherein the toner is circulated between the developer transport path 1 and the second developer transport path, and the sealing means is provided in the first developer transport path. It is an image forming apparatus.

According to the present invention according to claim 1 or 12, it is possible to prevent the cloud of toner generated by stirring the developer from being discharged to the outside of the developing apparatus.

According to the second aspect of the present invention, in addition to the effect of the present invention according to the first aspect, the toner cloud can be softly blocked.

According to the third aspect of the present invention, in addition to the effect of the present invention according to the second aspect, the magnetic brush can be formed with a simpler configuration as compared with the case where a magnet is not used.

According to the fourth aspect of the present invention, in addition to the effect of the present invention according to the third aspect, the outflow of the toner cloud can be further prevented as compared with the case where there is no protruding wall.

According to the fifth aspect of the present invention, in addition to the effect of the present invention according to the fourth aspect, it is possible to prevent the developer from stagnation due to the protruding wall.

According to the sixth aspect of the present invention, in addition to the effect of the present invention according to the first aspect, a simple configuration prevents the toner cloud from flowing out as compared with the case where the magnetic brush is formed by a magnet. can do.

According to the seventh aspect of the present invention, in addition to the effect of the present invention according to the sixth aspect, the sealing member can be extended to the inside from the outer end of the stirring and transporting portion.

According to the eighth aspect of the present invention, in addition to the effect of the present invention according to the first aspect, it is possible to prevent the cloud of toner generated in the portion where the stirring action of the developer is large from flowing out.

According to the invention of claim 9, in addition to the effect of the invention of claim 8, it is possible to prevent the cloud of toner generated by the transport of the developer from flowing out.

According to the invention of claim 10, in addition to the effect of the invention of claim 8, it is possible to prevent the toner cloud from flowing out on both sides of the first developer transport path.

According to the invention of claim 11, in addition to the effect of the invention of claim 10, it is possible to prevent the cloud of toner generated by the stirring of the stirring unit from flowing out.

According to the thirteenth aspect of the present invention, in addition to the effect of the present invention according to the twelfth aspect, the outflow of the toner cloud in the first developing agent conveying path for sending the developing agent to the second developing conveying path is prevented. can do.

It is sectional drawing which shows the image forming apparatus which concerns on 1st Embodiment of this invention. It is a vertical sectional view which shows the developing apparatus which concerns on 1st Embodiment of this invention. It is a cross-sectional view which shows the developing apparatus which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the part of the 1st developer transport path in the developing apparatus which concerns on 1st Embodiment of this invention. It is a partial cross-sectional view which shows the developing apparatus which concerns on 2nd Embodiment of this invention. It is a partial cross-sectional view which shows the developing apparatus which concerns on 3rd Embodiment of this invention.

Next, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 shows an image forming apparatus 10 according to a first embodiment of the present invention. The image forming apparatus 10 has an image forming apparatus main body 12, and in the image forming apparatus main body 12, an image forming unit 14 for forming a toner image on a recording medium and a toner image formed by the image forming unit 14 are recorded as a recording medium. The transfer device 16 that transfers to the image, the fixing device 18 that fixes the toner image transferred to the recording medium by the transfer device 16 to the recording medium, the recording medium supply device 20 that supplies the recording medium to the image forming unit 14, and the manual feed supply device. 22 and a reconveying device 24 are provided.

Further, the upper part of the image forming apparatus main body 12 is used as a discharge unit 30 from which the recording medium is discharged. Further, for example, on the front side (left side in FIG. 1) of the image forming apparatus main body 12, an operation unit 32 such as a touch panel for operating the image forming apparatus 10 is provided. The operation unit 32 displays control information, instruction information, and the like of the image forming apparatus 10, and also accepts input by the user such as instruction information. That is, the user can operate the image forming apparatus 10 via the operation unit 32.

The image forming unit 14 is an electrophotographic type, and is charged by an image holder 34 made of a photoconductor, a charging device 36 made of, for example, a charging roll that uniformly charges the image holder 34, and the charging device 36. The image holder 34 includes an exposure unit 38 that scans light so as to form an electrostatic latent image, and a developing device 40 that visualizes the latent image of the image holder 34 formed by the exposure unit 38. The developing device 40 will be described in detail later. As another embodiment, the exposure unit 38 can use an LED, a surface emitting laser, or the like.

The fixing device 18 has a heating roll 42 having a heat source inside and a pressure roll 44 pressed against the heating roll 42, and heats and pressurizes the toner image transferred to the recording medium to form an image. The toner image formed by the portion 14 is fixed to the recording medium.

The recording medium supply device 20 is provided below the inside of the image forming apparatus main body 12 and supplies the recording medium to the image forming unit 14. The recording medium supply device 20 has a first supply device 20a and a second supply device 20b. The first supply device 20a and the second supply device 20b can store recording media having different thicknesses, sizes, etc., and image forming units 14 have recording media having different thicknesses, sizes, etc. It is possible to supply to.

The first supply device 20a and the second supply device 20b have recording medium storage containers 46a and 46b. The recording media storage containers 46a and 46b are stored so as to stack the recording media, and the recording medium storage containers 46a and 46b have delivery rolls 47a and 47b for feeding the recording media from the sheet storage containers 46a and 46b. Further, the recording medium conveyed from the delivery rolls 47a and 47b is conveyed toward the resist roll 50, which will be described later, along the paper feed transfer paths 45a and 45b on the downstream side of the recording medium of the delivery rolls 47a and 47b in the transfer direction. It has paper rolls 48a and 48b and handling rolls 49a and 49b provided so as to face the paper feed rolls 48a and 48b.

Further, a manual feed supply device 22 is arranged on the side surface (left side surface in FIG. 1) of the image forming apparatus main body 12. The manual feed supply device 22 sends out the manual feed mounting portion 56 on which the recording medium is placed and the recording medium mounted on the manual feed mounting portion 56 toward the resist roll 50 along the manual feed transfer path 57. And have. Further, the manual insertion mounting portion 56 opens when rotated in the direction of the arrow shown in FIG. 1, and is supported by the image forming apparatus main body 12 so as to be openable and closable.

Further, a discharge roll 52 is provided on the downstream side of the fixing device 18 in the recording medium transport direction. The discharge roll 52 is designed so that the rotation direction can be switched, and by rotating in one direction, the recording medium conveyed from the fixing device 18 is discharged to the discharge unit 30. Further, the discharge roll 52 draws the recording medium from the discharge unit 30 side into the image forming apparatus main body 12 by rotating in the other direction, and supplies the recording medium to the reversing transport path 28.

The reversing transport path 28 is used for reversing the recording medium on which the developer image is fixed on one surface by the fixing device 18 and transporting the recording medium to the image forming unit 14 again, from the discharge roll 52 to the resist roll 50. The recording medium is transported to the upstream side of the. Further, a reverse transport roll 54 that is rotationally driven is arranged along the reverse transport path 28. The reconveying device 24 is composed of the reversing transport path 28 and the reversing transport roll 54.

2 to 4 show the details of the developing apparatus 40.
The developing device 40 is a two-component developing device that develops by stirring a developer composed of a carrier and toner to charge the toner.

The developing device 40 has a developing device main body 60. The upper lid 60b is joined to the main body 60a to form a structure. A developer conveying section 62 is provided in the developing apparatus main body 60. In the developer transport section 62, a first developer transport path 64a and a second developer transport path 64b are formed in parallel in the longitudinal direction. The first developer transfer path 64a and the second developer transfer path 64b are partitioned in the longitudinal direction by a partition wall 66, and the first openings 65a are mutually formed at both ends of the stirring transfer paths 64a and 64b in the longitudinal direction. And are connected via a second opening 65b. Stirring transport members 68a and 68b are arranged in the first developer transport path 64a and the second developer transport path 64b, respectively. The stirring and transporting members 68a and 68b are composed of rotating shafts 70a and 70b and stirring and transporting portions 72a and 72b spirally formed around the rotating shafts 70a and 70b. The developer transport unit 62 stirs and transports the developer by rotating stirring and transporting members 68a and 68b to charge the carrier and toner. Further, in the stirring and transporting member 68a in the first developer transporting path 64a, a plurality of stirring and transporting portions 69 are formed so as to project radially from the rotation shaft 70a between the stirring and transporting portions 68a.

Further, a developing roll 74, which is a developing member, is provided in the developing apparatus main body 60. The developing roll 74 is composed of a magnet portion 76 that is fixed inside and forms a magnetic pole on the peripheral surface, and a sleeve 78 that rotates around the magnet portion 76. Further, the developing roll 74 faces the image holder 34 described above, and the toner adhering to the magnetic brush formed around the sleeve 78 is moved to the latent image formed on the image holder 34. It has become. Further, the developing apparatus main body 60 is provided with a layer thickness regulating member 80 facing the developing roll 74. The layer thickness regulating member 80 regulates the layer thickness of the magnetic brush formed on the sleeve 78.

Further, on the outside of the developing apparatus main body 60, a detecting means 82 for detecting the carrier amount of the first developing agent transport path 64a is provided. The detecting means 82 is, for example, a magnetic permeability sensor, and detects the amount of carriers within the detection range of the first developer transport path 64a by detecting the magnetic permeability.

Further, a toner supply unit 84 is provided at one end in the longitudinal direction of the first developer transfer path 64a of the developing apparatus main body 60. A toner supply port 86 is formed in the toner supply unit 84. The toner supply port 86 is connected to a toner cartridge (not shown) directly or via a reserve tank. When a large amount of carriers is detected by the detection means described above, toner is supplied to the toner supply port 86. Further, a transport member 88 for supplying toner is provided in the toner supply unit 84. New toner is supplied to the first developer transport path 64a by the toner supply transport member 86.

The sealing portions 90 constituting the sealing means are provided at two locations in the first developer transport path 64a, a slightly downstream side of the first opening 65a and a slightly upstream side of the first opening 65b. .. The sealing portion 90 is composed of a protruding wall 92 extending downward from the upper lid 60b and a magnet 94 fixed to the lower portion of the protruding wall 92. The protruding wall 92 and the magnet 94 are formed in an arc shape so as to surround the upper part of the stirring and transporting portion 68a. The magnet 94 is, for example, a rubber magnet made of rubber. Carriers in the developer adhere to the magnet 94 to form a magnetic brush. The magnetic brush is, for example, about several millimeters, and the toner cloud that is about to pass through the brush is captured by magnetic force at this time, and the toner cloud is captured from both ends of the first developer transport path 64a in the longitudinal direction and the like. Prevent it from leaking out.

The plurality of stirring portions 69 described above are formed only between the sealing portions 90 and 90 in the longitudinal direction. The plurality of stirring units 69 are adapted to stir the developer at the central portion in the longitudinal direction of the first developer transport path 64a. The plurality of stirring units 69 have more stirring power than the stirring and transporting unit 72a. Therefore, toner cloud is likely to be generated in the central portion of the first developer transport path 64a, but leakage of toner cloud is reduced by the blocking portions 90, 90 on both sides.

In the first embodiment, the blocking portions 90 are provided at two locations on the upstream side and the downstream side of the first developer transport path 64a, but the toner cloud is also transported in the transport direction as the developer is transported. Therefore, it may be provided only on the downstream side of the first developer transport path 64a.

Further, since the magnetic brush is formed by the magnet 94, the amount of carriers forming the magnetic brush may be insufficient. In this case, in order to compensate for the insufficient amount of carriers, the inside of the developing apparatus 40 may be insufficient. A predetermined amount of carriers may be increased.

In the above configuration, the toner supplied from the toner supply port 86 enters the first developer transport path 64a and is supplied to the first developer transport path 64a by the rotation of the transport member 88. In the first developer transport path 64a, the original developer and the newly supplied toner are transported to the downstream side while being agitated by the rotation of the stirring and transporting member 68a.

For example, in the case of continuously printing an image having a high image density (a large amount of toner to be printed per sheet), a large amount of toner is supplied from the toner supply port 86, and the first developer transport path 64a Insufficient stirring causes toner clouding.

The toner cloud generated in this way flies particularly in the upper part of the first developer transport path 64a in the direction of gravity, and the leaky portion of the first developer transport path 64a, for example, the first developer transport path 64a. It tries to leak to the outside of the developing apparatus 40 from both sides in the longitudinal direction.

However, in the first developer transport path 64a, the upper part of the first developer transport path 64a in the gravity direction is blocked by the blocking portions 90, 90, so that the toner cloud is formed in the blocking portions 90, 90. It is captured by the magnetic brush, which prevents the sealing portions 90, 90 from moving to the outside.

FIG. 5 shows the blockade 90 in the second embodiment.
In this second embodiment, the protruding wall 92 is formed obliquely so as to gradually become thinner in the longitudinal cross section. Since the protruding wall 92 is formed diagonally in this way, it is possible to prevent the developer from staying as a lump at the portion of the protruding wall 92. Further, the magnet 94 may be formed diagonally.

FIG. 6 shows the blockade 90 in the third embodiment.
In this third embodiment, the sealing portion 90 is configured as a sealing member 96 extending downward from the upper lid 60b without using a magnet. The sealing member 96 physically prevents the toner cloud from passing through.

However, if the sealing member 96 is extended downward, the sealing member 96 may interfere with the stirring and transporting portion 72a. Therefore, a notch 98 is formed in the stirring and transporting portion 72a along the radial direction, and the sealing member 96 is inserted into the notch 98 to prevent interference between the sealing member 96 and the stirring and transporting portion 72a.

In the above embodiment, an example in which the developing device is provided independently in the image forming apparatus has been described, but it is also applicable to the case where the developing device is integrated with the image holder, the charging device, the exposure unit, or the like. can do.

10 Image forming device 12 Image forming device main body 14 Image forming part 16 Transfer device 18 Fixing device 20 Recording medium supply device 20a First supply device 20b Second supply device 22 Manual feed supply device 24 Re-conveyor 28 Reverse transfer path 30 Discharge Unit 32 Operation unit 34 Image holder 36 Charging device 38 Exposure unit 40 Developing device 42 Heating roll 44 Pressurizing roll 45a, 45b Paper feed transfer path 46a, 46b Recording medium storage container 47a, 47b Feed roll 48a, 48b Paper feed roll 49a , 49b Handling roll 50 Resist roll 52 Discharge roll 54 Reverse transfer roll 56 Manual loading part 57 Manual transfer path 58 Feeding roll 60 Developer body 62 Developer transfer section 64a, 64b Developer transfer path 66 Partition wall 68a, 68b Stirring transfer Member 69 Stirring part 70a, 70b Rotating shaft 72a, 72b Stirring transport part 74 Development roll 76 Magnet part 78 Sleeve 80 Layer thickness control member 82 Detection means 84 Toner supply part 86 Toner supply port 88 Toner supply transport member 90 Sealing part 92 Protruding wall 94 Magnet 96 Sealing member 98 Notch

Claims (13)

With the main body of the developing device
A developer transport member provided in the developer transport path formed in the main body of the developing apparatus and transporting the developer by rotating, and a developer transport member.
A sealing means provided toward the developer transporting member of the developer transport path and blocking at least the upper part of the developer transport path in the direction of gravity.
A developing device having. The developing apparatus according to claim 1, wherein the sealing means is a magnetic brush composed of a carrier of the developing agent. The developing apparatus according to claim 2, wherein the sealing means has a magnet for forming the magnetic brush. The developing apparatus according to claim 3, wherein the magnet is provided on a protruding wall protruding from the developing apparatus main body toward the developing agent transport path. The developing apparatus according to claim 4, wherein the protruding wall is formed obliquely toward the protruding side with respect to the transport direction of the developer transported to the developer transport path. The developing apparatus according to claim 1, wherein the sealing means is composed of a sealing member projecting from the developing apparatus main body to the developer transport path. The developer transporting member has a rotating rotating shaft and a stirring and transporting portion spirally provided on the rotating shaft, and the sealing member is a portion in which a part of the stirring and transporting portion is cut off. 6. The developing apparatus according to claim 6. The developer transport path includes a first developer transport path that transports the developer in one direction from the toner supply port and a second developer transport path that transports the developer in the opposite direction from the first developer transport path. It has a transport path, and the toner is circulated between the first developer transport path and the second developer transport path to transport the toner, and the sealing means is transferred to the first developer transport path. The developing apparatus according to claim 1, which is provided. The developing apparatus according to claim 8, wherein the sealing means is provided on the downstream side of the first developer transport path in the toner transport direction. The developing apparatus according to claim 8, wherein the sealing means is provided on the upstream side and the downstream side in the toner transport direction of the first developer transport path. The developer conveying member has a rotating rotating shaft, a stirring and conveying portion spirally provided on the rotating shaft, and a stirring portion provided so as to project in the radial direction of the rotating shaft. The developing apparatus according to claim 10, wherein is arranged between the sealing means on the upstream side and the sealing means on the downstream side. An image holder that holds the toner image and
It has a developing device that supplies toner to the image holder, and has
The developing device
With the main body of the developing device
A developer transport member provided in the developer transport path formed in the main body of the developing apparatus and transporting the developer by rotating, and a developer transport member.
A sealing means provided toward the developer transporting member of the developer transport path and blocking at least the upper part of the developer transport path in the direction of gravity.
An image forming apparatus having. Further having a developing member provided in the developing apparatus main body and facing the image holder,
The developer transport path is a first developer transport path for transporting the developer in one direction from the toner supply port and a developer transport path in the opposite direction from the first developer transport path to the developing member. It has a second developer transport path for supplying the toner, and the toner is circulated between the first developer transport path and the second developer transport path to transport the toner, and the sealing means is a sealing means. The image forming apparatus according to claim 12, which is provided in the first developing agent transport path.

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