JP6809124B2 - Develop equipment, process cartridge, and image forming equipment - Google Patents

Description

The present invention relates to a developing apparatus for developing a latent image formed on the surface of an image carrier, and a process cartridge and an image forming apparatus including the developing apparatus.

Conventionally, in a developing device installed in an image forming device using an electrophotographic method such as a copier, a printer, a facsimile, or a multifunction device thereof, a first carrying member is arranged so as to face below the developing roller. It is known that the second transport member is arranged so as to face the lower side of the first transport member, and the developing agent circulation path is formed by the two transport members arranged in the vertical direction. (See, for example, Patent Document 1.).

Specifically, in the developing apparatus in Patent Document 1, a first transport member is disposed so as to face below the developing roller (developer carrier), and a wall is provided below the first transport member (supply transport unit). A second transport member (stirring transport section) is arranged via the section. The first transport member transports the developer from one end side in the longitudinal direction to the other end side in the longitudinal direction. The second transport member transports the developer from the other end side in the longitudinal direction to the one end side in the longitudinal direction. Further, the upstream side of the first transport path by the first transport member and the downstream side of the second transport path by the second transport member are in communication with each other, and the downstream side of the first transport path and the upstream side of the second transport path. It communicates with the side.
In the developing apparatus configured in this way, a circulation path for transporting the developer in the longitudinal direction is formed by the first transport member (first transport path) and the second transport member (second transport path), and the first The developer is supplied to the developing roller by the transport member, and the developer separated from the developing roller is collected.

On the other hand, in Patent Document 2, a first transport member (second transport screw) is disposed so as to face below the developing roller, and a second transport member (second transport member) is disposed so as to face the side of the first transport member. A developing device in which a first transport screw) is arranged and two transport paths are arranged in a horizontal direction, and a developing case is formed so as to be divisible into a lower case and an upper case is disclosed. .. Further, the upper case is provided with a vent (exhaust port) for reducing the internal pressure of the developing device, a filter covering the vent, and a toner replenishing port for supplying toner to the developing device. There is. Further, a developing roller and two transfer screws are held in the lower case. Then, with respect to the lower case in which the developing roller and the two transport screws are held, the two transport paths are exposed with the upper case removed.

In the developing apparatus of Patent Document 2 described above, the developing case is configured to be divisible into two, and the upper case provided with the vent (exhaust port) and the filter can be removed, so that the upper case is removed. It can be expected to have some effect that maintenance such as cleaning of the filter can be easily performed in the state.
However, in the developing apparatus of Patent Document 1 described above, since two transport members (transport paths) are arranged in the vertical direction, two developing cases are provided so that the two transport paths can be exposed as in Patent Document 2. If the development roller and the two transport members are held in one case, the developer will spill out of the transport path at once when the other case is removed. It will be.

The present invention has been made to solve the above-mentioned problems, and is a developing case so that the maintenance of the apparatus can be easily performed even when the two transport members are arranged in the vertical direction. Even when the developer is configured to be separable, the problem of spilling the developer when the other case is removed with respect to one case in which the developing roller and the two transport members are held is reduced. The present invention is to provide a developing device, a process cartridge, and an image forming device.

The developing apparatus according to the present invention is disposed so as to face the developing roller carrying the developing agent and below the developing roller, and conveys the developing agent from one end side in the longitudinal direction to the other end side in the longitudinal direction. A first transport member that supplies the developer to the developing roller and collects the developer separated from the developing roller is disposed so as to face below the first transport member, and the developer is placed in the longitudinal direction. A developing apparatus including a second transport member that transports from the other end side toward one end side in the longitudinal direction to form a circulation path for the developer together with the first transport member, and a developing case that houses the developer. A developer regulating member that regulates the developer supplied and supported on the developing roller facing below the developing roller is provided, and the first transport member rotates in the same direction as the rotating direction of the developing roller. The developing case is a developing case that holds the developing roller, the first conveying member, and the second conveying member, and the developing roller, the first conveying member, and the second conveying member. It is provided with a developing case which is detachably installed with respect to the developing case in a state where the and is held and covers the developing roller from above to the side, and the developing case is of the developing apparatus. It is provided with a vent for communicating the inside and the outside, a filter for covering the vent, and a sealing member for sliding contact with an end portion of the outer peripheral surface of the developing roller in the longitudinal direction.

According to the present invention, even when the two transport members are arranged in the vertical direction and the developing case is configured to be separable so that the maintenance of the apparatus can be easily performed, the developing is performed. A developing device, a process cartridge, and an image forming device that reduce the problem of spilling of the developer when the other case is removed from one case in which the rollers and the two transport members are held. Can be provided.

It is an overall block diagram which shows the image forming apparatus in embodiment of this invention. It is a block diagram which shows the image-forming part. It is the schematic sectional drawing which looked at the developing apparatus in the longitudinal direction. It is the schematic which shows the state of the developer housed in the developing apparatus. It is sectional drawing which shows the structure of the development case. (A) A perspective view showing a state in which the developing case and the second developing case are removed from the developing device, and (B) a perspective view showing a state in which all the developing cases are attached. It is a perspective view which shows the state which the development case was removed from a developing roller. (A) A schematic cross-sectional view showing a state in which the developing case is attached to the developing device, and (B) a schematic cross-sectional view showing a state in which the developing case is removed from the developing device.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In each figure, the same or corresponding parts are designated by the same reference numerals, and the duplicated description thereof will be appropriately simplified or omitted.

First, FIG. 1 describes the overall configuration and operation of the image forming apparatus 1.
In FIG. 1, 1 is a tandem color copier as an image forming apparatus, 3 is a document conveying unit that conveys a document to a document reading unit, 4 is a document reading unit that reads image information of a document, and 5 is loaded with an output image. Indicates the output tray.
Further, 7 is a paper feed unit for accommodating a recording medium P such as transfer paper, 9 is a resist roller for adjusting the transport timing of the recording medium P, and 11Y, 11M, 11C, and 11BK are each color (yellow, magenta, cyan, black). ) Is a photoconductor drum as an image carrier on which a toner image is formed.
Reference numeral 13 is a developing device for developing an electrostatic latent image formed on the surfaces of the photoconductor drums 11Y, 11M, 11C, 11BK, and 14 is a toner formed on the photoconductor drums 11Y, 11M, 11C, 11BK. A primary transfer bias roller, which transfers an image overlaid on a recording medium P, is shown.
Further, 17 is an intermediate transfer belt on which toner images of a plurality of colors are superimposed and transferred, 18 is a secondary transfer bias roller for transferring the color toner image on the intermediate transfer belt 17 onto the recording medium P, and 20 is a recording medium. A fixing device for fixing the unfixed image on P, 28 indicates a toner container of each color for supplying toner (toner particles) of each color (yellow, cyan, magenta, black) to the developing device 13.

Hereinafter, the operation of the image forming apparatus during normal color image forming will be described.
Note that FIG. 2 can also be referred to for the image forming process performed on the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK.
First, the original is conveyed from the platen by the transfer roller of the original transfer unit 3 and placed on the contact glass of the original reading unit 4. Then, the document reading unit 4 optically reads the image information of the document placed on the contact glass.

Specifically, the document reading unit 4 scans the image of the document on the contact glass while irradiating the light emitted from the illumination lamp. Then, the light reflected by the document is imaged on the color sensor through the mirror group and the lens. The color image information of the original is read by the color sensor for each RGB (red, green, blue) color separation light, and then converted into an electrical image signal. Further, based on the RGB color-separated image signal, the image processing unit performs processing such as color conversion processing, color correction processing, and spatial frequency correction processing to obtain color image information of yellow, magenta, cyan, and black.

Then, the image information of each color of yellow, magenta, cyan, and black is transmitted to the writing unit. Then, a laser beam L (see FIG. 2) based on the image information of each color is emitted from the writing unit toward the surfaces of the corresponding photoconductor drums 11Y, 11M, 11C, and 11BK, respectively.

On the other hand, the four photoconductor drums 11Y, 11M, 11C, and 11BK are each rotating in the clockwise direction of FIG. Then, first, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK are uniformly charged at the portion facing the charging portion 12 (see FIG. 2) (the charging step). In this way, charging potentials are formed on the photoconductor drums 11Y, 11M, 11C, and 11BK. After that, the surfaces of the charged photoconductor drums 11Y, 11M, 11C, and 11BK reach the irradiation positions of the respective laser beams L.
In the writing unit, laser light corresponding to an image signal is emitted from four light sources corresponding to each color. Each laser beam passes through a different optical path for each of the yellow, magenta, cyan, and black color components (exposure process).

The laser beam corresponding to the yellow component irradiates the surface of the photoconductor drum 11Y, which is the first from the left side of the paper surface. At this time, the laser beam of the yellow component is scanned in the rotation axis direction (main scanning direction) of the photoconductor drum 11Y by the polygon mirror rotating at high speed. In this way, an electrostatic latent image corresponding to the yellow component is formed on the photoconductor drum 11Y after being charged by the charging unit 12.

Similarly, the laser beam corresponding to the magenta component is applied to the surface of the photoconductor drum 11M second from the left on the paper surface to form an electrostatic latent image corresponding to the magenta component. The cyan component laser beam is applied to the surface of the photoconductor drum 11C, which is the third from the left on the paper surface, to form an electrostatic latent image of the cyan component. The laser beam of the black component is applied to the surface of the photoconductor drum 11BK, which is the fourth from the left on the paper surface, to form an electrostatic latent image of the black component.

After that, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK on which the electrostatic latent images of each color are formed reach the positions facing the developing device 13, respectively. Then, toner of each color is supplied from each developing device 13 onto the photoconductor drums 11Y, 11M, 11C, 11BK, and the latent image on the photoconductor drums 11Y, 11M, 11C, 11BK is developed (development step). .).
After that, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK after the developing step reach the facing portions with the intermediate transfer belt 17, respectively. Here, a primary transfer bias roller 14 is installed on each of the opposing portions so as to abut on the inner peripheral surface of the intermediate transfer belt 17. Then, at the position of the primary transfer bias roller 14, the toner images of each color formed on the photoconductor drums 11Y, 11M, 11C, and 11BK are sequentially superimposed and transferred on the intermediate transfer belt 17 (primary transfer). It is a process.).

Then, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK after the transfer step reach the positions facing the cleaning unit 15, respectively. Then, the cleaning unit 15 collects the untransferred toner remaining on the photoconductor drums 11Y, 11M, 11C, and 11BK (this is a cleaning step).
After that, the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK pass through the static elimination unit, and a series of image forming processes on the photoconductor drums 11Y, 11M, 11C, and 11BK are completed.

On the other hand, the intermediate transfer belt 17 on which the toners of the respective colors on the photoconductor drums 11Y, 11M, 11C, and 11BK are superimposed and transferred (supported) travels in the counterclockwise direction in the drawing, and is transferred to the secondary transfer bias roller 18. Reach the opposite position of. Then, the color toner image carried on the intermediate transfer belt 17 is transferred onto the recording medium P at the position facing the secondary transfer bias roller 18 (this is the secondary transfer step).
After that, the surface of the intermediate transfer belt 17 reaches the position of the intermediate transfer belt cleaning portion. Then, the untransferred toner adhering to the intermediate transfer belt 17 is collected by the intermediate transfer belt cleaning unit, and a series of transfer processes on the intermediate transfer belt 17 are completed.

Here, the recording medium P conveyed between the intermediate transfer belt 17 and the secondary transfer bias roller 18 (which is the secondary transfer nip) is conveyed from the paper feed unit 7 via the resist roller 9 and the like. It is a thing.
Specifically, the recording medium P fed by the paper feed roller 8 is guided to the resist roller 9 from the paper feed unit 7 that houses the recording medium P after passing through the transport guide. The recording medium P that has reached the resist roller 9 is conveyed toward the secondary transfer nip at the same timing.

Then, the recording medium P on which the full-color image is transferred is subsequently guided to the fixing device 20. In the fixing device 20, the color image is fixed on the recording medium P by the nip of the fixing roller and the pressurizing roller.
Then, the recording medium P after the fixing step is discharged as an output image to the outside of the apparatus main body 1 by the paper ejection roller, and is stacked on the paper ejection tray 5, and a series of image forming processes is completed.

Next, the process cartridge 10 (image-creating unit) in the image forming apparatus will be described in detail with reference to FIGS. 2, 3 and the like.
FIG. 2 is a configuration diagram showing the process cartridge 10 (image-creating portion), and is a view seen in a cross section orthogonal to the rotation axis of the photoconductor drum 11. FIG. 3 is a schematic cross-sectional view (cross-sectional view in the vertical direction) of the developing device 13 as viewed in the longitudinal direction.
Since each image forming unit has almost the same structure, the process cartridge and the developing device have alphabetic symbols (Y, C, M, BK) in FIGS. 2 and 3 (and FIGS. 4 to 8 described later). ) Is excluded.

As shown in FIG. 2, the process cartridge is a unit in which a photoconductor drum 11 as an image carrier, a charging unit 12 (and a cleaning roller 22), a developing device 13, and a cleaning unit 15 are integrated. It is detachably installed with respect to the image forming apparatus main body 100. Then, when the life of the process cartridge 10 is reached, the process cartridge 10 is removed from the image forming apparatus main body 100 and replaced with a new one.

The photoconductor drum 11 as an image carrier is a negatively charged organic photoconductor, and is rotationally driven clockwise by a rotation drive mechanism.
The charging portion 12 is an elastic charging roller in which a medium-resistive urethane foam layer in which urethane resin, carbon black as conductive particles, a sulfide agent, a foaming agent, or the like is formulated is formed in a roller shape on a core metal. The material of the medium resistance layer of the charged portion 12 is urethane, ethylene-propylene-diene polyethylene (EPDM), butadiene acrylonitrile rubber (NBR), silicone rubber, isoprene rubber, etc., and carbon black or metal oxide for resistance adjustment. It is also possible to use a rubber material in which a conductive substance such as is dispersed, or a foamed material thereof.
The cleaning roller 22 is arranged so as to come into contact with the charging portion 12 (charging roller), and cleans foreign matter adhering to the surface of the charging portion 12.
The cleaning unit 15 is provided with a cleaning blade that is in sliding contact with the photoconductor drum 11, and mechanically removes and recovers the untransferred toner on the photoconductor drum 11.

In the developing apparatus 13, a developing roller 13a as a developing agent carrier is arranged so as to face the photoconductor drum 11 with a slight gap through an opening A (formed in the developing case 13j). A developing region is formed on both facing portions where the photoconductor drum 11 and the magnetic brush (developer G in a raised state) come into contact with each other. A developer G (two-component developer) composed of toner T and carrier C is housed in the developing apparatus 13. Then, the developing device 13 develops an electrostatic latent image formed on the surface of the photoconductor drum 11 (forms a toner image). The configuration and operation of the developing device 13 will be described in detail later.

With reference to FIG. 1, the toner container 28 contains a toner T for being supplied into the developing apparatus 13. Specifically, development is performed from the toner container 28 via the toner transfer tube based on the information of the toner concentration (the ratio of the toner in the developer G) detected by the magnetic sensor installed in the developing device 13. Toner T is appropriately supplied from the supply port 13d (see FIG. 3) toward the inside of the device 13.
The supply of the toner T is not limited to the toner density information, and may be performed based on the image density information detected from the reflectance of the toner image formed on the photoconductor drum 11. Further, the execution of the toner T supply may be determined by combining these different information.

Hereinafter, the developing apparatus 13 in the image forming apparatus will be described in detail.
With reference to FIGS. 2 and 3, the developing apparatus 13 includes a developing roller 13a as a developer carrier, a supply screw 13b1 as a first conveying member, a conveying screw 13b2 as a second conveying member, and a developer regulating member. It is composed of a round bar doctor 13c, a partition member 13e as a wall portion, a developing case 13j covering the developing device 13, a filter 13k covering the vent D, and the like. Members such as the developing roller 13a, the supply screw 13b1, the transport screw 13b2, the round bar doctor 13c, and the partition member 13e are included in the developing case 13j (housing).
In the developing roller 13a as a developing agent carrier, a sleeve 13a2 formed of a non-magnetic material such as aluminum, brass, stainless steel, or a conductive resin in a cylindrical shape is supplied by a rotation drive mechanism, together with a screw 13b1 and a transport screw 13b2. It is configured to rotate in the direction of the arrow shown in. With reference to FIG. 3, a magnet 13a1 forming a plurality of magnetic poles (S1 pole, N1 pole, S2 pole, N2 pole, N3 pole) is fixedly formed in the sleeve 13a2 of the developing roller 13a on the peripheral surface of the sleeve 13a2. Has been done. The developer G carried on the developing roller 13a is conveyed along with the rotation of the developing roller 13a in a predetermined rotation direction (counterclockwise in FIG. 2), and is carried by the round bar doctor 13c (developer regulating member). ) Is reached. Then, the developer G on the developing roller 13a is regulated to an appropriate amount at this position, and then transported to a position facing the photoconductor drum 11 (a developing region). Then, the toner is adsorbed on the latent image formed on the photoconductor drum 11 by the electric field (developing electric field) formed in the developing region.

With reference to FIG. 2, the plurality of magnetic poles formed around the developing roller 13a (sleeve 13a2) by the magnet 13a1 are the N1 pole (main magnetic pole) and the N1 pole formed at positions facing the photoconductor drum 11. The S2 pole (conveying magnet) formed on the downstream side (downstream side in the rotation direction of the developing roller 13a) and above the developing case 13j, and the downstream side of the S2 pole formed diagonally above the developing roller 13a. On the downstream side of the agent release magnetic pole (N pole) formed above the first transport path B1 at the position sandwiched between the N2 pole (agent release pre-magnet) and the N2 pole and the N3 pole. There are N3 poles (magnetic poles after agent separation) formed above the first transport path B1, and S1 poles (pumping magnetic poles) formed from the position facing the supply screw 13b1 to the vicinity of the facing position with the round bar doctor 13c. ), Etc.
First, the S1 pole (pumping magnetic pole) acts on the carrier as a magnetic material, and the developer G contained in the first transport path B1 is pumped onto the developing roller 13a. A part of the developer G supported on the developing roller 13a is scraped off at the position of the round bar doctor 13c as the developing agent regulating member, and is returned to the first transport path B1. On the other hand, at the position of the round bar doctor 13c on which the magnetic force due to the S1 pole acts, the developer G carried on the developing roller 13a after passing through the doctor gap between the round bar doctor 13c and the developing roller 13a is N1 pole (mainly). It stands at the position of the magnetic pole) and becomes a magnetic brush in the developing area and slides into contact with the photoconductor drum 11. In this way, the toner T in the developer G supported on the developing roller 13a adheres to the latent image on the photoconductor drum 11. After that, the developer G that has passed through the position of the N1 pole is conveyed to the position of the agent separation magnetic pole (N pole) by the S2 pole and the N2 pole. Then, at the position of the agent separating magnetic pole, a repulsive magnetic field (a magnetic field acting in a direction away from the developing roller 13a) acts on the carrier, and the developing agent G after the developing step supported on the developing roller 13a is released. It is detached from the developing roller 13a. The developer G after desorption falls into the first transport path B1, is collected by the supply screw 13b1, and is transported toward the downstream of the first transport path B1.

The six magnetic poles described above are formed by five poles (S1 pole, N1 pole, S2 pole, N2 pole, and N3 pole) magnetized on the magnet 13a1 of the developing roller 13a. Of the six magnetic poles, only the agent separation magnetic pole (N pole) is not directly formed by the pole magnetized on the magnet 13a1, but is the same pole (in the present embodiment, the N pole). It is formed by being sandwiched between two magnetic poles (N2 pole and N3 pole) that serve as (.).

With reference to FIG. 2 and the like, the round bar doctor 13c as the developer regulating member is a magnetic columnar member arranged so as to face below the developing roller 13a. Then, the developing roller 13a rotates in the counterclockwise direction of FIG. 2, and the photoconductor drum 11 rotates in the clockwise direction of FIG.
With such a configuration, when the photoconductor drum 11 is arranged below the intermediate transfer belt 17 for the purpose of shortening the transport path of the recording medium P and reducing the size of the image forming apparatus main body 1 in the horizontal direction. Even so, in order to allow the developing roller 13a to rotate in the forward direction with respect to the photoconductor drum 11 in the developing gap, the round bar doctor 13c is arranged above the developing roller 13a to form the photoconductor drum. Compared with the case where the direction of rotation of the developing roller 13a with respect to 11 is opposite, a sufficient developing time in the developing gap can be secured and the developing ability can be enhanced.

The two transport members (the supply screw 13b1 and the transport screw 13b2) carry the developer G housed in the developing apparatus 13 in the longitudinal direction (vertical to the paper surface in FIG. 2 and in the left-right direction in FIG. 3). Yes), stir and mix while circulating. Both the supply screw 13b1 and the transport screw 13b2 are screw members in which a screw portion is spirally wound around a shaft portion.

The supply screw 13b1 as the first transport member is disposed so as to face below the developing roller 13a, and transports the developer G from one end side in the longitudinal direction toward the other end side in the longitudinal direction while transporting the developing roller 13a. The developer is supplied to the developing roller 13a and the developer separated from the developing roller 13a is collected.
Specifically, the supply screw 13b1 (first transport member) is arranged at a position below the developing roller 13a and facing the developing roller 13a. Then, the developer G is horizontally conveyed in the longitudinal direction (rotational axis direction) (transportation from the right to the left shown by the broken arrow in FIG. 3), and at the position of the pumping magnetic pole (S1 pole). The developer G is supplied onto the developing roller 13a, and the developer G that has fallen off from the developing roller 13a at the position of the agent separating magnetic pole (N pole) is conveyed toward the downstream side in the axial direction. The supply screw 13b1 rotates counterclockwise in FIG.

The transport screw 13b2 as the second transport member is disposed so as to face below the supply screw 13b1 (first transport member), and the developer G is directed from the other end side in the longitudinal direction to one end side in the longitudinal direction. It is conveyed to form a circulation path for the developer G together with the supply screw 13b1.
Specifically, the transport screw 13b2 (second transport member) is arranged at a position below the supply screw 13b1 and facing the developing roller 13a via the supply screw 13b1. Then, the developer G is horizontally transported in the longitudinal direction in the second transport path B2 (transportation from the left to the right indicated by the broken line arrow in FIG. 3). In the present embodiment, the rotation direction of the transport screw 13b2 is set to be opposite to the rotation direction of the supply screw 13b1 (clockwise in FIG. 2).

Gears are installed on one end side (the right end portion in FIG. 3) of the shaft portion of the developing roller 13a (sleeve 13a2), the supply screw 13b1, and the transport screw 13b2, and these are gears. A row is formed and the members 13a, 13b1 and 13b2 are rotated in the rotation direction described above.
Further, in both the supply screw 13b1 and the transport screw 13b2, the shaft portions at both ends thereof are rotatably held in the developing case 13j via a bearing (in this embodiment, a sliding bearing). Further, in order to prevent the toner T (developer G) from entering the bearing inside the bearing that holds the supply screw 13b1 and the transport screw 13b2 in the developing case 13j (on the inner side of the developing device 13). (In this embodiment, it is a G seal) is installed.

Then, in the transport screw 13b2, the developer is circulated from the axially downstream side of the first transport path B1 by the supply screw 13b1 via the second communication portion 13 g (second relay portion). Then, the transport screw 13b2 transports the developer G to the upstream side in the axial direction of the first transport path B1 by the supply screw 13b1 via the first communication portion 13f (first relay portion) (in the dashed arrow in FIG. 3). It is the transport shown.).
Both the supply screw 13b1 and the transport screw 13b2 are arranged so that the rotation axes are substantially horizontal, like the developing roller 13a and the photoconductor drum 11. Further, both the supply screw 13b1 and the transport screw 13b2 are those in which a screw portion (which is formed with a predetermined screw pitch and a number of threads of 1) is spirally wound around a shaft portion. Is. The number of threads of the screw portion may be a plurality of threads in order to stabilize the transport of the developer, and in particular, the number of threads of the screw portion of the supply screw 13b1 may be a plurality of threads.

The first transport path B1 by the supply screw 13b1 and the second transport path B2 by the transport screw 13b2 are separated by a partition member 13e (wall portion).
With reference to FIG. 3, the upstream side of the first transfer path B1 by the supply screw 13b1 and the downstream side of the second transfer path B2 by the transfer screw 13b2 communicate with each other via the first communication portion 13f. The developer G that has reached the downstream side of the second transport path by the transport screw 13b2 stays in the vicinity of the first communication portion 13f and swells, and the developer screw G1 of the first transport path B1 by the supply screw 13b1 passes through the first communication portion 13f. It will be transported (supplied) to the upstream side (see also FIG. 4).
Further, referring to FIG. 3, the downstream side of the first transfer path B1 by the supply screw 13b1 and the upstream side of the second transfer path B2 by the transfer screw 13b2 communicate with each other via the second communication portion 13g. .. Then, the developer G that has reached the downstream side of the first transport path B1 by the supply screw 13b1 (the developer G that was not supplied onto the developing roller 13a in the first transport path B1 and the developing roller at the position of the fourth magnetic pole). The developer G that has separated and dropped from 13a) falls by its own weight at the second communication portion 13g and reaches the upstream side of the second transport path B2.

In addition, in order to improve the transportability of the developer in the first communication portion 13f (the transfer of the developer G against the direction of gravity from the second transport path B2 to the first transport path B1), the transport screw 13b2 A paddle-shaped portion or a screw portion in which the winding direction of the screw is formed in the opposite direction may be provided at a position on the downstream side of the above (a position corresponding to the first communication portion 13f).
Further, in the second transport path B2, in order to promote the swelling (retention) of the developer G in the vicinity of the first communication portion 13f, the rotation speed of the transport screw 13b2 is compared with the rotation speed (conveyability) of the supply screw 13b1. It is also possible to reduce the number (transportability).

With such a configuration, the two transport members (supply screw 13b1 and transport screw 13b2) form a circulation path for circulating the developer G in the longitudinal direction in the developing apparatus 13. That is, when the developing apparatus 13 is operated, the developing agent G contained in the developing apparatus 13 flows in the direction of the broken line arrow in FIG.
Then, in this way, the developing apparatus is formed by forming the circulation path of the developer G (the first transport path B1 and the second transport path B2) with respect to the developing roller 13a in the vertical direction instead of the horizontal direction. The horizontal size of 13 can be reduced (it can be vertically long). In particular, in the tandem type color image forming apparatus 1 in which a plurality of developing devices 13 (image forming sections) are arranged side by side in the horizontal direction, the size of the plurality of developing devices 13 (image forming sections) in the horizontal direction can be reduced. , The overall horizontal size can be effectively reduced.

A magnetic sensor for detecting the toner concentration of the developer G circulating in the apparatus is installed in the transport path by the transport screw 13b2. Then, based on the toner concentration information detected by the magnetic sensor, the inside of the developing device 13 is arranged from the toner container 28 via the replenishment port 13d (arranged outside in the longitudinal direction with respect to the second communication portion 13g). A new toner T is supplied toward.
Further, referring to FIG. 3, the replenishment port 13d (toner replenishment port) is above the upstream side of the second transport path B2 by the transport screw 13b2 and is located away from the developing region (longitudinal direction of the developing roller 13a). It is arranged outside the range of.). Then, the new toner T discharged from the toner container 28 is appropriately replenished from the replenishment port 13d toward the inside of the developing device 13 (replenishment in the direction of the white arrow in FIG. 3). By installing the replenishment port 13d in the vicinity of the second communication portion 13g in this way, the developer G supplied by dropping its own weight from the second communication portion 13g toward the downstream side in the second transport path B2. On the other hand, the replenishing toner can be sufficiently dispersed and mixed over a relatively long time.
In the present embodiment, the supply port 13d is arranged in the second transport path B2, but the position of the supply port 13d is not limited to this, and for example, the first transport path B1 is extended in the longitudinal direction. It can also be placed above the downstream side.

Since the developing agent G transferred from the second transport path B2 to the first transport path B1 tends to stay in the vicinity of the first communication portion 13f, the second transport path B1 also tends to retain the developer G as shown in FIG. Even in the path B2, the surface of the developer G is high at a position close to the first communication portion 13f, and the surface of the developer G is low at a position far from the first communication portion 13f.
Further, since the developer G drops its own weight from the first transport path B1 to the second transport path B2 in the vicinity of the second communication portion 13 g, as shown in FIG. 4, the second transport path B2 has the second communication. The developer G that has fallen by its own weight stays in the vicinity of the portion 13 g, and the agent surface becomes slightly higher.

With reference to FIG. 2 and the like, in the developing apparatus 13 of the present embodiment, a vent D is formed in the developing case 13j so as to communicate with the outside of the developing apparatus 13 in the vicinity of the developing roller 13a. Specifically, the vent D is on the downstream side in the rotation direction of the developing roller 13a with respect to the developing region where the developing roller 13a faces the photoconductor drum 11, and is above the developing roller 13a and in the developing case 13j1 (described later). (See FIGS. 6 and 7), and are formed so as to communicate with each other in the space between them.
A filter 13k configured to collect the developer G and allow air to pass through the developer G is installed so as to cover the vent D.

More specifically, the vent D is in the direction of rotation of the developing roller 13a with respect to the opening A (the position where the developing roller 13a faces the photoconductor drum 11 and the position where the developing region is formed). At the position on the downstream side, the film was sucked from the gap between the developing roller 13a and the developing case 13j (developing case 13j1) toward the inside of the developing device 13 (first transport path B1) along the rotation of the developing roller 13a. The air is arranged at a position where it can be discharged to the outside of the developing apparatus 13 as it is.
That is, the vent D is arranged in the path where the suction airflow on the downstream side of the developing region flows in the developing apparatus 13, and the air sucked from the gap between the developing roller 13a and the developing case 13j is on the left side of FIG. And the air is discharged to the outside of the developing device 13.
The vent D is above the back surface of the developing case 13j (developing apparatus 13) (which is a substantially vertical wall surface on the side not facing the photoconductor drum 11) (almost the same height as the uppermost portion of the developing roller 13a). It is arranged so as to open in the horizontal direction.

On the other hand, the filter 13k is held in the developing case 13j (developing case 13j1) so as to cover the vent D. Specifically, the filter 13k is arranged so as to cover the vent D and substantially face the developing roller 13a. The filter 13k is made of a porous material such as urethane foam or a non-woven fabric, and is configured to collect toner T (developer G) and allow only air to pass through.

With these configurations, even if the internal pressure of the developing apparatus 13 is likely to increase due to the suction airflow from the downstream side of the developing region (opening A), the filter 13k prevents the toner T (developer G) from leaking to the outside. At the same time, air is released from the vent D through the filter 13k to suppress an increase in the internal pressure of the developing apparatus 13, so that the scattering of toner to the outside of the developing apparatus 13 is reduced.
In particular, in the present embodiment, the vent D covered with the filter 13k is not formed in the first transport path B1 (or the second transport path B2), but is in the vicinity of the developing roller 13a (suction airflow). Since it is a flow path and is formed at a position that does not directly face the first transport path B1), the toner floating inside the first transport path B1 (or the second transport path B2). The problem that the filter is clogged by T (developer G) is reduced.

As the developing agent G used in the present embodiment, a known developer G can be used.
For example, as the toner T (the toner in the developer G, the toner in the toner container 28), a polymerized toner having a small diameter of about 5.8 μm can be used.
Further, as the carrier C in the developer G, a small diameter carrier formed so that the weight average particle size is 20 to 60 μm can be used.

Hereinafter, the characteristic configuration and operation of the developing apparatus 13 according to the present embodiment will be described.
As described above with reference to FIG. 2 and the like, the developing apparatus 13 is provided with a developing case 13j that covers the developing apparatus 13.
Then, in the present embodiment, as shown in FIGS. 5 to 7, the developing case 13j is configured so that it can be divided into a developing case 13j2 and a developing case 13j1.

With reference to FIGS. 5 and 6, the developing case 13j2 rotatably holds the developing roller 13a, the supply screw 13b1 (first transport member), and the transport screw 13b2 (second transport member), respectively. It is configured.
The under-development case 13j2 is further configured to be further divided into a first under-development case 13j21 and a second under-development case 13j22. The first developing case 13j21 is configured to rotatably hold the developing roller 13a, the supply screw 13b1, and the transport screw 13b2, respectively. The second under-development case 13j22 is detachably installed with respect to the first under-development case 13j21 in a state where the developing roller 13a, the supply screw 13b1 and the transport screw 13b2 are held. The second developing case 13j22 is formed so as to cover the supply screw 13b1 and the transport screw 13b2 from the side.
As shown in FIG. 6, five fitting portions 13j210 projecting upward are formed on the bottom surface of the first developing case 13j21 on the back surface side. Then, the second under-development case is fitted to the first under-development case 13j21 so as to fit the five recesses formed on the bottom surface of the second under-development case 13j22 into the five fitting portions 13j210. 13j22 is fitted to form the under-development case 13j2. It is preferable to install a sealing material made of polyurethane foam or the like on the boundary surface (contact surface) between the first developed case 13j21 and the second developed case 13j22 to improve the sealing property of that portion.

The developing case 13j1 is detachably installed with respect to the developing case 13j2 in which the developing roller 13a, the supply screw 13b1 (first transport member), and the transport screw 13b2 (second transport member) are held. .. The developing case 13j1 is configured to cover the developing roller 13a from above to the side (the side on the back side).
On the boundary surface 13j10 of the developing case 13j1 (the contact surface that abuts on the upper surface of the second developing case 13j22), three boss portions (portions surrounded by a broken line in FIG. 7) projecting downward. ) Is formed. Then, the under-development case 13j2 (second under-development case 13j22) is fitted so that the three boss portions are fitted into the three fitting portions 13j220 (holes) formed on the upper surface of the second under-development case 13j22. The developing case 13j1 is fitted to the developing case 13j to form the developing case 13j. It is also possible to install a sealing material made of foamed polyurethane or the like on the boundary surface (contact surface) between the developing case 13j1 and the developing case 13j2 to improve the sealing property of that portion.

Here, as shown in FIG. 5, in the present embodiment, the process cartridge case 10a for holding the photoconductor drum 11, the charging portion 12 (and the cleaning roller 22), and the cleaning portion 15 is provided. Then, the process cartridge case 10a, the above-mentioned developing case 13j1, the first developing case 13j21, and the second developing case 13j22 are sandwiched between the face plates provided at both ends in the longitudinal direction. The process cartridge 10 is formed by screwing it to the face plate of the above.
The fixing of the developing case 13j1, the first developing case 13j21, and the second developing case 13j22 is not limited to the method using the face plate described above, and the developing case 13j1 and the first developing case are fixed. A method of directly screwing the case 13j21 and the second developing case 13j22 to each other can also be used.

Here, as shown in FIGS. 6 and 7, in the present embodiment, the developing case 13j1 includes a vent D for communicating the inside and the outside of the developing device 13 and a filter 13k covering the vent D. , A sealing member 13r that is in sliding contact with the longitudinal end of the outer peripheral surface of the developing roller 13a is installed.
As described above with reference to FIG. 2 and the like, the vent D and the filter 13k are for suppressing an increase in the internal pressure of the developing device 13 and preventing toner scattering.

The seal member 13r is made of a low friction elastic material such as urethane foam or a flocked seal. The sealing member 13r covers a part of the outer peripheral surface (within a range of about 180 degrees) of the sleeve end portion 13a22, which is the end portion of the developing roller 13a (sleeve 13a2), and covers the developing roller 13a (sleeve end portion 13a22). It is formed in a substantially arc shape so as to be in sliding contact with. The sealing member 13r is installed at a position corresponding to both ends of the developing roller 13a (sleeve 13a2).
By installing the sealing member 13r, it is possible to reduce the problem that the developer G leaks from both ends of the developing roller 13a and the developing case 13j (development case 13j1).

In the present embodiment, the developing roller 13a has a mirror finish on the outer peripheral surface of the sleeve end portion 13a22 to which the sealing member 13r is in sliding contact. As a result, the adhesion between the seal member 13r and the sleeve end 13a22 is enhanced to improve the sealability, and the sliding resistance between the seal member 13r and the sleeve end 13a22 is lowered to reduce the sliding resistance between the seal member 13r and the sleeve end 13a22, so that the seal member 13r and the developing roller 13a Abrasion deterioration will be reduced. The range of the sleeve end 13a22 is an undeveloped area.
Further, the developing roller 13a has a plurality of irregularities formed on the outer peripheral surface of the sleeve central portion 13a21 other than the sleeve end portion 13a22. This is because the range of the sleeve central portion 13a21 is the developing region, and it is necessary to carry the developer G on the surface thereof.

As described above, the developing device 13 (process cartridge 10) in the present embodiment is configured so that the developing case 13j1 can be removed from the developing device 13 by itself.
That is, when viewed from the main part side of the developing apparatus 13, the developing case 13j1 was removed as shown in FIG. 8B from the state in which the developing case 13j1 was installed as shown in FIG. 8A. In this state, the developing roller 13a and the supply screw 13b1 (first transport path B1) held in the developing case 13j2 are exposed. Further, when viewed from the side of the developing case 13j1, the seal member 13r is exposed and both the outside and the inside of the filter 13k are exposed in the state of being removed from the developing device 13 alone.

Therefore, with the developing case 13j1 removed from the developing apparatus 13, it is possible to easily clean or replace the filter 13k that is clogged with time and the seal member 13r that is worn or soiled with time. ..
In addition, maintenance such as cleaning of the developing roller 13a and the supply screw 13b1 (first transport path B1) can be performed on the developing apparatus 13 in which the developing case 13j1 is removed.
Since the developing case 13j1 is formed so as to cover the side from above the developing roller 13a located above the apparatus, the developing agent G is removed from the developing apparatus 13 from which the developing case 13j1 is removed. It will not spill at once.
That is, as in the case of the present embodiment, the developing device 13 has two transport members (supply screw 13b1 and transport screw 13b2) arranged in the vertical direction, and maintenance of the developing device 13 is easy. Even when the developing case 13j is configured to be separable so that the development case 13j can be divided, the developing roller 13a and the two transporting members 13b1 and 13b2 are held in one case (developing case 13j2). When the other case (development case 13j1) is removed, the problem that the developer G spills out is alleviated.

In particular, in the present embodiment, as shown in FIG. 8B, the developing case 13j2 is a supply screw 13b1 (first transport member) when the developing case 13j1 is removed from the developing apparatus 13. It is formed so as to cover a position higher than the upper end. That is, the boundary surface 13j10 of the developing case 13j1 that comes into contact with the developing case 13j2 is at a position higher than that of the supply screw 13b1.
With this configuration, the problem that the developer G spills from the developing device 13 from which the developing case 13j1 has been removed can be suppressed.

Further, as shown by the alternate long and short dash line in FIG. 5, in the present embodiment, the position of the bottom surface of the under-development case 13j2 and the position of the bottom surface of the process cartridge case 10a are configured to be flat surfaces having the same height. ing.
As a result, the developing device 13 (process cartridge 10) is removed from the image forming device main body 1 and is placed on the floor or the like, and the developing device 13 (process cartridge 10) is attached to the image forming device main body 1. The posture in the stationary state is substantially the same as the posture in the stationary state, and the posture in the stationary state does not change from the posture shown in FIG. 5 to the tilted posture. Therefore, the posture of the developing apparatus 13 from which the developing case 13j1 has been removed becomes the posture shown in FIG. 8B, and the problem that the developer G spills from the developing apparatus 13 is suppressed.

Further, in the present embodiment, the supply screw 13b1 (first transport member) is a screw member that rotates in the same direction as the rotation direction of the developing roller 13a (counterclockwise in FIG. 8). That is, the supply screw 13b1 rotates from the front side (the side close to the photoconductor drum 11) of the developing device 13 upward, and further from the upper side toward the back side. Therefore, as shown in FIG. 8, the height of the agent surface on the back surface side of the developer G in the first transport path B1 is lower than the height of the agent surface on the front surface side.
Therefore, the problem that the developer G is spilled from the developing apparatus 13 in which the developing case 13j1 is removed and the back side is largely exposed is suppressed.

Further, in the present embodiment, the developing roller 13a is one of a plurality of magnetic poles formed on the outer peripheral surface thereof, and carries the developer G after the developing step supported on the outer peripheral surface in the first transport path B1. The agent release magnetic pole (the portion described as (N) in FIG. 8) for returning to (the transport path by the supply screw 13b1) is on the inner surface of the developing case 13j1 (in FIG. 8 (A)). , It is a part shown by a broken line.) It is formed at a position facing it.
With this configuration, the developer G supported on the developing roller 13a does not easily adhere to the inner surface of the developing case 13j1, so that the developing case 13j1 is removed from the developing apparatus 13. Occasionally, the problem that the developer G spills from the inner surface of the developing case 13j1 is prevented.

In the present embodiment, as shown in FIG. 8B, before removing the developing case 13j1 from the developing apparatus 13, the supply roller 13b1 and the transport screw 13b2 are manually rotated in the normal rotation direction. It is preferable to rotate in the opposite direction.
By manually rotating the supply roller 13b1 and the transfer screw 13b2 in the reverse direction in this way, the developer G contained in the first transfer path B1 and the second transfer path B2 is opposite to the normal transfer direction. It will be transported in the direction. At this time, since the rotation speed at which the supply roller 13b1 and the transfer screw 13b2 are manually rotated in the reverse direction is not so fast, the developer G in the first transfer path B1 drops by its own weight from the first communication portion 13f and is second conveyed. While moving to the path B2, the developer G in the second transport path B2 hardly moves from the second communication portion 13 g to the second transport path B2 against gravity. Therefore, the surface of the developer G contained in the first transport path B1 becomes even lower. Therefore, when the developing case 13j1 is subsequently removed from the developing device 13, the problem that the developing agent G spills from the developing device 13 is further suppressed.

Further, as described above with reference to FIG. 6 and the like, the under-development case 13j2 is configured so that it can be divided into a first under-development case 13j21 and a second under-development case 13j22.
With this configuration, as shown in FIG. 6 (A), the developing screw 13b1 (first transport) is provided by removing the developing case 13j1 and the second developing case 13j22 from the developing apparatus 13. The route B1) and the transfer screw 13b2 (second transfer path B2) are exposed, and maintenance thereof can be performed. However, in that case, it is preferable to change the posture of the developing apparatus 13 so that the exposed surface faces upward so that the developer G contained in the first transport path B1 and the second transport path B2 does not spill. ..

As described above, in the developing apparatus 13 of the present embodiment, the developing case 13j holds the developing roller 13a, the supply screw 13b1 (first transport member), and the transport screw 13b2 (second transport member) under development. The case 13j2 and the developing case 13j1 which are detachably installed on the developing case 13j2 and cover the developing roller 13a from above to the side are separable. The developing case 13j1 is provided with a vent D, a filter 13k that covers the vent D, and a seal member 13r that is in sliding contact with the longitudinal end of the outer peripheral surface of the developing roller 13a.
Thereby, in the case where the two transport members (the supply screw 13b1 and the transport screw 13b2) are arranged in the vertical direction, the developing case 13j can easily perform the maintenance of the developing apparatus 13. The developer G spills out when the developing case 13j1 is removed from the developing case 13j2 in which the developing roller 13a and the two conveying members are held, even when the developing roller 13a and the two conveying members are held. Problems can be reduced.

In the present embodiment, the present invention has been applied to the developing apparatus 13 configured as one of the constituent members of the process cartridge 10. However, the application of the present invention is not limited to this, and the present invention can naturally be applied even when the developing device 13 is configured as a unit that is attached to and detached from the image forming apparatus main body by itself. ..
Here, in the present application, the "process cartridge" refers to a charged portion that charges the image carrier, a developing device (developer) that develops a latent image formed on the image carrier, and cleaning on the image carrier. It is defined as a unit in which at least one of the cleaning unit (cleaning device) and the image carrier are integrated and detachably installed with respect to the main body of the image forming apparatus.

It is clear that the present invention is not limited to the present embodiment, and within the scope of the technical idea of the present invention, the present embodiment may be appropriately modified in addition to the suggestions in the present embodiment. is there. Further, the number, position, shape, etc. of the constituent members are not limited to the present embodiment, and can be a suitable number, position, shape, etc. for carrying out the present invention.

In the specification of the present application and the like, the directions such as "upward", "downward", and "lateral" are defined as indicating the directions in the posture of the developing apparatus and the image forming apparatus in the normal use state.

1 Image forming apparatus (image forming apparatus main body),
10 process cartridge,
10a cartridge case,
11, 11Y, 11C, 11M, 11BK Photoreceptor drum (image carrier),
13 Developing equipment (development unit),
13a Development roller (developer carrier),
13a1 magnet, 13a2 sleeve,
13a21 sleeve center, 13a22 sleeve end,
13b1 supply screw (first transport member),
13b2 transport screw (second transport member),
13c Round bar doctor (developer regulator),
13e Partition member (wall part),
13f 1st communication part,
13g 2nd communication part,
13j developing case,
13j1 developing case,
13j10 boundary surface (contact surface),
13j2 under development case,
13j21 1st under development case, 13j22 2nd under development case,
13j210 fitting part, 13j220 fitting part,
13k filter,
13r seal member (end seal),
B1 1st transport route, B2 2nd transport route,
D Ventilation port (exhaust port),
G developer (two-component developer), T toner, C carrier.

Japanese Patent No. 5975630 Japanese Patent No. 4786284

Claims (7)

A developing roller that supports the developer and
Arranged so as to face the lower side of the developing roller, the developing agent is supplied to the developing roller while being conveyed from one end side in the longitudinal direction to the other end side in the longitudinal direction, and is separated from the developing roller. The first transport member that collects the developing agent
Arranged so as to face the lower side of the first transport member, the developer is transported from the other end side in the longitudinal direction toward one end side in the longitudinal direction to form a circulation path for the developer together with the first transport member. With the second transport member
A developing case that houses the developer and
It is a developing device equipped with
A developer regulating member for regulating the developer supplied and supported on the developing roller facing below the developing roller is provided.
The first transport member is a screw member that rotates in the same direction as the rotation direction of the developing roller.
The developing case
A developing case that holds the developing roller, the first transport member, and the second transport member.
A developing case that is detachably installed on the developing case in which the developing roller, the first transport member, and the second transport member are held, and covers the developing roller from above to the side. ,
Equipped with
The developing case includes a vent that communicates the inside and the outside of the developing apparatus, a filter that covers the vent, and a seal member that slides into the longitudinal end of the outer peripheral surface of the developing roller. A developing device characterized by this. The first aspect of the present invention, wherein the under-development case is formed so as to cover a position higher than the upper end of the first transport member when the under-development case is removed from the developing apparatus. Developing equipment. The developed case
A first developing case that holds the developing roller, the first transport member, and the second transport member, and
The developing roller, the first transport member, and the second transport member are detachably installed with respect to the first developing case in a state where the first transport member and the second transport member are held. The second under-development case that covers from the side,
The developing apparatus according to claim 1 or 2, wherein the developing apparatus is provided with. A developing device that develops a latent image formed on an image carrier.
The vent is on the downstream side in the rotational direction of the developing roller with respect to the developing region in which the developing roller faces the image carrier, and communicates with the space above the developing roller and between the developing case. The developing apparatus according to any one of claims 1 to 3, wherein the developing apparatus is formed so as to perform the above. The developing roller is one of a plurality of magnetic poles formed on the outer peripheral surface thereof, and is an agent for returning the developing agent carried on the outer peripheral surface after the developing step to the conveying path by the first conveying member. The developing apparatus according to any one of claims 1 to 4, wherein the separate magnetic pole is formed at a position facing the inner side surface of the developing case. A process cartridge that is detachably installed with respect to the image forming apparatus body.
A process cartridge comprising the developing apparatus according to any one of claims 1 to 5 and an image carrier integrally provided. An image forming apparatus comprising the developing apparatus according to any one of claims 1 to 5 and an image carrier .

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