JP6573161B2 - Developing device, process cartridge, and image forming apparatus - Google Patents

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developing device that develops a latent image formed on the surface of an image carrier, and a process cartridge and an image forming device including the developing device, and in particular, a two-component developer or a one-component developer having at least toner. The present invention relates to a developing device, a process cartridge, and an image forming apparatus in which a developer such as the above is accommodated in advance.

  Conventionally, in a developing device installed in an image forming apparatus using an electrophotographic method such as a copying machine, a printer, a facsimile, or a complex machine thereof, two components consisting of a toner and a carrier when shipped from a factory or the like A preset type in which a developer (including the case where an additive or the like is added) is stored in advance is widely known (see, for example, Patent Documents 1 and 2).

Specifically, in Patent Document 1, a preset case containing a two-component developer is provided at the top of the developing device, and the developer contained in the preset case is removed by detaching the seal member from the preset case at the time of arrival. A technique for filling the interior of an empty developing device is disclosed.
In Patent Document 2, a space separated from the developing roller by a seal member is formed in the developing device at the time of shipment, and a two-component developer is accommodated in the space, and the space is sealed from the developing device at the time of arrival. A technique is disclosed in which the developer accommodated in the space is spread throughout the entire area of the developing device by removing the member.

  On the other hand, Patent Document 3 aims to prevent image density unevenness caused by toner adhering directly to the surface of a developing roller (developer carrier) in a developing device using a two-component developer. A technique for forming a surface layer of a developing roller with a material such as DLC or tin plating having a low toner adhesion force is disclosed.

In the prior art described above, the developer (two-component developer) is installed in a preset case or a space inside the developing device separated by a seal member so that the developer is not carried on the developer carrying member (developing roller) at the time of shipment. ) Is contained, it can be expected to reduce the problem that the toner adheres to the surface of the developer carrying member during transportation until it is loaded.
However, the above-described conventional technology takes time and effort to remove the seal member when it arrives, and requires extra space and cost for installing the seal member and the preset case.

In addition, the technique disclosed in Patent Document 3 has a problem that the toner adheres to the surface of the developer carrier because the surface layer of the developer carrier (development roller) is formed of a material having a small toner adhesion. It can be expected to reduce the effect to some extent.
However, an extra cost is required to form such a surface layer on the developer carrier. Further, since the surface layer of the developer carrying member is formed of a specific material, the surface characteristics of the developer carrying member may be changed, which may affect a good development process. In particular, if this technique is applied to a developing device of a one-component development system, it becomes difficult for toner to be carried on the surface of the developer carrying member, and a toner image having a desired density can be formed in the developing process. There is a possibility that defects such as defective image density may occur due to difficulty in formation on the image carrier.

  The present invention has been made to solve the above-described problems, and is shipped in a state where a developer is accommodated in the developing device with a relatively simple configuration and without installing a seal member or a preset case. However, the developing device and the process cartridge are less prone to problems such as toner sticking to the surface of the developer carrying member during transportation until they arrive, and less likely to cause problems such as poor image density in the development process after arrival. And providing an image forming apparatus.

The developing device according to the present invention is a developing device for developing a latent image formed on the surface of an image carrier that contains at least a developer containing toner, and is developed so as to face or abut against the image carrier. A developer carrying member carrying the developer, and at the time of shipment, in a state in which an anti-adhesive agent that is difficult to adhere to the surface of the developer carrying member compared to the toner is detachably applied to the surface of the developer carrying member, The developer is accommodated inside the developing device so as to be in contact with the developer carrying member coated with the anti-adhesion agent .

  According to the present invention, a developer having a relatively simple configuration, without being installed with a seal member or a preset case, even when shipped in a state where the developer is accommodated in the developing device, the developer at the time of transportation until it is loaded It is possible to provide a developing device, a process cartridge, and an image forming apparatus that are less likely to cause a problem that toner adheres to the surface of the carrier, and that a problem such as an image density defect does not easily occur in the developing process after arrival.

1 is an overall configuration diagram illustrating an image forming apparatus according to an embodiment of the present invention. It is sectional drawing which shows an image formation part. FIG. 3 is a cross-sectional view showing an AA cross section of the developing device in the image forming unit of FIG. 2. (A) Schematic showing the developing device at the time of shipment, (B) Schematic showing the state of the developing device in the initial adjustment mode at the time of arrival. As a modification, (A) a diagram showing a developing device at the time of a developing step, and (B) a diagram showing a developing device at the time of shipment.

Embodiment.
Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, in each figure, the same code | symbol is attached | subjected to the part which is the same or it corresponds, The duplication description is simplified or abbreviate | omitted suitably.

First, the overall configuration and operation of the image forming apparatus 1 will be described with reference to FIG.
In FIG. 1, 1 is a color printer as an image forming apparatus, 2 is a writing unit that emits laser light L based on image information, and 20Y, 20M, 20C, and 20BK correspond to each color (yellow, magenta, cyan, and black). A process cartridge 21 is a photosensitive drum as an image carrier housed in each of the process cartridges 20Y, 20M, 20C, and 20BK, 22 is a charging unit that charges the surface of the photosensitive drum 21, and 23Y, 23M, 23C, and 23BK. Is a developing device (developing unit) that develops the electrostatic latent image formed on the surface of the photosensitive drum 21, and 24 is a primary transfer that transfers the toner image formed on the surface of the photosensitive drum 21 to the intermediate transfer belt 27. A bias roller 25 indicates a cleaning device that collects untransferred toner on the photosensitive drum 21.

  In addition, 27 is an intermediate transfer belt on which toner images of respective colors are transferred in an overlapping manner, 28 is a secondary transfer bias roller for transferring the toner image formed on the surface of the intermediate transfer belt 27 to the recording medium P, and 29 is an intermediate transfer belt. 27 is an intermediate transfer belt cleaning unit that collects untransferred toner, 30 is a transfer belt that transports a recording medium P onto which four color toner images are transferred, 32Y, 32M, 32C, and 32BK are developing devices 23Y, 23M, 23C, and 23BK, a toner replenishing unit that replenishes toner of each color, 61 a paper feeding unit that stores a recording medium P such as transfer paper, and 66 a fixing device that fixes an unfixed image on the recording medium P. Show.

Here, each of the process cartridges 20Y, 20M, 20C, and 20BK is obtained by integrating the photosensitive drum 21, the charging unit 22, and the cleaning device 25, respectively. The process cartridges 20Y, 20M, 20C, and 20BK are exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle. Similarly, the developing devices 23Y, 23M, 23C, and 23BK are also exchanged with respect to the apparatus main body 1 in a predetermined exchange cycle.
Image formation of each color (yellow, magenta, cyan, black) is performed on the photosensitive drum 21 in each of the process cartridges 20Y, 20M, 20C, and 20BK.

Hereinafter, an operation during normal color image formation in the image forming apparatus will be described.
First, the surface of the photosensitive drum 21 is uniformly charged at a position facing the charging unit 22 (charging process). Thereafter, the surface of the charged photosensitive drum 21 reaches the irradiation position of each laser beam L.

  On the other hand, in the writing unit 2, a laser beam L corresponding to the image signal is emitted from the light source corresponding to each color. The laser light L is incident on the polygon mirror 3 and reflected, and then passes through the lenses 4 and 5. The laser light L after passing through the lenses 4 and 5 passes through different optical paths for each of the yellow, magenta, cyan, and black color components (this is an exposure process).

The laser beam L corresponding to the yellow component is reflected by the mirrors 6 to 8 and then irradiated to the surface of the photosensitive drum 21 of the first process cartridge 20Y from the left side of the drawing. At this time, the yellow component laser light L is scanned in the direction of the rotation axis (main scanning direction) of the photosensitive drum 21 by the polygon mirror 3 that rotates at high speed. Thus, an electrostatic latent image corresponding to the yellow component is formed on the photosensitive drum 21 charged by the charging unit 22.
Similarly, the laser beam L corresponding to the magenta component is reflected by the mirrors 9 to 11 and then irradiated to the surface of the photosensitive drum 21 of the second process cartridge 20M from the left side of the drawing, so as to correspond to the magenta component. An electrostatic latent image is formed. The cyan component laser light L is reflected by the mirrors 12 to 14 and then irradiated to the surface of the photosensitive drum 21 of the third process cartridge 20C from the left side of the drawing to form a cyan component electrostatic latent image. . The black component laser beam L is reflected by the mirror 15 and then is irradiated onto the surface of the photosensitive drum 21 of the fourth process cartridge 20BK from the left side of the drawing to form a black component electrostatic latent image.

Thereafter, the surface of the photosensitive drum 21 on which the electrostatic latent images of the respective colors are formed further rotates and reaches positions facing the developing devices 23Y, 23M, 23C, and 23BK, respectively. Then, the respective color toners are supplied from the developing devices 23Y, 23M, 23C, and 23BK onto the photosensitive drum 21, and the latent image on the photosensitive drum 21 is developed (this is a developing step).
Thereafter, the surface of the photosensitive drum 21 after the development process reaches a position facing the intermediate transfer belt 27 (primary transfer nip portion). Here, the primary transfer bias roller 24 is installed at each facing position so as to contact the inner peripheral surface of the intermediate transfer belt 27. Then, the image of each color formed on the photosensitive drum 21 is sequentially transferred onto the intermediate transfer belt 27 at the position of the primary transfer bias roller 24 (this is a primary transfer process).

Then, the surface of the photosensitive drum 21 after the primary transfer process reaches a position facing the cleaning device 25. Then, the untransferred toner remaining on the photosensitive drum 21 is collected by the cleaning device 25 (this is a cleaning process).
Thereafter, the surface of the photoconductive drum 21 passes through a static elimination unit (not shown), and a series of image forming processes on the photoconductive drum 21 is completed.

On the other hand, the surface of the intermediate transfer belt 27 on which the images of the respective colors on the photosensitive drum 21 are transferred in an overlapping manner travels in the direction of the arrow in the drawing and reaches the position of the secondary transfer bias roller 28. Then, the full-color image on the intermediate transfer belt 27 is secondarily transferred onto the recording medium P at the position of the secondary transfer bias roller 28 (secondary transfer process).
Thereafter, the surface of the intermediate transfer belt 27 reaches the position of the intermediate transfer belt cleaning unit 29. Then, the untransferred toner on the intermediate transfer belt 27 is collected by the intermediate transfer belt cleaning unit 29, and a series of transfer processes on the intermediate transfer belt 27 is completed.

Here, the recording medium P at the position of the secondary transfer bias roller 28 is transported from the paper feeding unit 61 via the transport guide 63, the registration roller 64, and the like.
Specifically, the recording medium P fed by the paper feeding roller 62 from the paper feeding unit 61 that stores the recording medium P passes through the conveyance guide 63 and is guided to the registration roller 64. The recording medium P that has reached the registration roller 64 (timing roller) is conveyed toward the position of the secondary transfer bias roller 28 in synchronization with the toner image on the intermediate transfer belt 27.

Thereafter, the recording medium P on which the full-color image is transferred is guided to the fixing device 66 by the transfer belt 30. In the fixing device 66, the color image is fixed on the recording medium P at the nip between the fixing roller 67 and the pressure roller 68 (this is a fixing step). The fixing roller 67 is a hollow roller member, and a heater is provided therein. The heater provided in the fixing roller 67 is on / off controlled based on the detection result of the temperature sensor that detects the surface temperature of the fixing roller 67, and thereby the surface temperature (fixing temperature) of the fixing roller 67. Is maintained in a desired range, and a good fixing process is performed.
Then, the recording medium P after the fixing process is discharged as an output image by the paper discharge roller 69 to the outside of the apparatus main body 1, and a series of image forming processes is completed.

Next, the image forming unit of the image forming apparatus 1 will be described in detail with reference to FIGS.
FIG. 2 is a cross-sectional view showing the image forming unit, and FIG. 3 is a cross-sectional view taken along the line AA showing the developing device 23.
Since the four image forming units installed in the image forming apparatus main body 1 have substantially the same structure except that the color of the toner T used in the image forming process is different, reference numerals in the process cartridge, the developing device, and the toner replenishing unit are used. The alphabet (Y, M, C, BK) is removed for illustration.

  As shown in FIG. 2, the process cartridge 20 mainly contains a photosensitive drum 21 as an image carrier, a charging unit 22, and a cleaning device 25 integrally in a case 26. Here, in the present embodiment, the cleaning device 25 includes a lubricant supply roller 25 b for supplying (applying) a lubricant to the surface of the photosensitive drum 21 in addition to the cleaning blade 25 a that contacts the photosensitive drum 21. The solid lubricant 25c, the compression spring 25d, and the like are installed and function as a lubricant supply device, which will be described in detail later.

  The developing device 23 (developing unit) mainly includes a developing roller 23a as a developer carrying member that forms a developing region facing the photosensitive drum 21, and a first transport screw 23b1 (first transport member) facing the developing roller 23a. ), The second conveying screw 23b2 (second conveying member) facing the first conveying screw 23b1 via the partition member 23e, and the amount of the developer G carried on the developing roller 23a facing the developing roller 23a are regulated. A doctor blade 23d as a developer regulating member, a toner concentration sensor 23g for detecting the toner concentration of the developer G in the developing device 23, an inlet seal 23j held by a casing member 23i, and the like.

Inside the developing device 23, a two-component developer G (developer) composed of a carrier C and a toner T is accommodated.
The developing roller 23a is configured to form a developing region facing the photosensitive drum 21 with a minute gap therebetween. As shown in FIG. 3, the developing roller 23a includes a magnet body 23a1 that is fixed inside and forms a plurality of poles (magnetic poles) on the roller outer peripheral surface, and a sleeve 23a2 that rotates around the magnet body 23a1. Composed.

  Conveying screws 23b1 and 23b2 serving as a plurality of conveying members convey a developer G accommodated in the developing device 23 in the longitudinal direction, and a circulation path (circulation paths indicated by broken-line arrows in FIG. 3). Form. That is, the plurality of conveying screws 23b1 and 23b2 (conveying members) convey a plurality of conveying paths B1 for conveying the developer G in the longitudinal direction (the left-right direction in FIG. 3 and the direction perpendicular to the paper surface in FIG. 2). B2 is formed. Specifically, a developer G circulation path is formed by the first transport path B1 by the first transport screw 23b1 and the second transport path B2 by the second transport screw 23b2.

The first transport path B1 and the second transport path B2 are separated from each other by a partition member 23e (wall portion), and both longitudinal ends of the two transport paths B1 and B2 communicate with each other. Specifically, referring to FIG. 3, the end of the first transport path B1 on the downstream side in the transport direction and the end of the second transport path B2 on the upstream side in the transport direction communicate with each other via the first relay section. In addition, the end on the upstream side in the transport direction of the first transport path B1 and the end on the downstream side in the transport direction of the second transport path B2 communicate with each other via the second relay section. That is, the partition member 23e is disposed at a position excluding both ends in the longitudinal direction.
The first transport screw 23b1 (first transport path B1) is disposed so as to face the developing roller 23a, and the second transport screw 23b2 (first transport path B1) is provided via the partition member 23e. It is arranged to face the first transport path B1).
In the present embodiment, the two conveying screws 23b1 and 23b2 (a plurality of conveying members) are arranged in parallel in the horizontal direction. Each of the two conveying screws 23b1 and 23b2 has a screw portion wound around a shaft portion.

The above-described image forming process will be described in more detail with a focus on the developing process.
The developing roller 23a rotates in the arrow direction (clockwise direction) in FIG. As shown in FIG. 3, the developer G in the developing device 23 is generated by the rotation of the first conveying screw 23 b 1 and the second conveying screw 23 b 2 disposed so as to interpose the partition member 23 e therebetween in the arrow direction. It circulates in the longitudinal direction while being agitated and mixed with the toner T replenished from the replenishing part 32 through the replenishing port 23f (circulation in the direction of the broken line arrow in FIG. 3).
Then, the toner T that is frictionally charged and adsorbed on the carrier C is pumped onto the developing roller 23a together with the carrier C by the agent pumping pole formed on the developing roller 23a. The developer carried on the developing roller 23a is conveyed in the direction of the arrow in FIG. 2 and reaches a position facing the doctor blade 23d. The developer on the developing roller 23a is conveyed to a position facing the photosensitive drum 21 (development area) after the developer amount is made appropriate at this position. The toner is attracted to the latent image formed on the photosensitive drum 21 by the electric field formed in the development area. Thereafter, the developer remaining on the developing roller 21a reaches above the first conveying screw 23b1 as the sleeve rotates, and is detached from the developing roller 21a at this position. Here, the electric field in the development region is generated by a predetermined voltage (development bias) applied to the development roller 23a by a power supply unit (not shown) for development, the charging process, and the exposure process. And a surface potential (latent image potential) formed on the surface.

  A plurality of poles are formed by the magnet body 23a1 on the outer peripheral surface of the sleeve 23a2 of the developing roller 23a. Specifically, the magnet body 23a1 includes three N-pole magnet portions and two S-pole magnet portions. By these magnet portions, a developer pumping electrode for pumping the developer G onto the developing roller 23a, a transport pole for transporting the developer G carried on the developing roller 23a to the doctor blade 23d, and the developer G A magnetic force distribution including a transport pole for transporting to the development area, a main electrode formed in the development area, and an agent separation pole for separating the developer G after passing through the development area from the development roller 23a It is formed on 23a. Due to the magnetic force distribution, the developer G moves on the developing roller 23a as the sleeve 23a2 rotates.

  Here, the toner replenishing unit 32 provided in the apparatus main body includes a replaceable toner bottle 33, a toner hopper unit 34 that holds and rotates the toner bottle 33, and replenishes the developing device 23 with fresh toner T. , Is composed of. The toner bottle 33 contains toner T (any one of yellow, magenta, cyan, and black). In addition, a spiral protrusion is formed on the inner peripheral surface of the toner bottle 33.

The toner T in the toner bottle 33 is appropriately replenished into the developing device 23 from the replenishing port 23f as the toner T in the developing device 23 is consumed. Consumption of the toner T in the developing device 23 is a toner concentration sensor 23g (magnetic permeability sensor) that magnetically detects the toner concentration of the developer G in the device 23 (the ratio of the toner T in the developer G). Detected by. In this embodiment, the toner density of the developer G in the developing device 23 is controlled to be 5 to 9% by weight (the center of the target is 7% by weight).
The replenishing port 23f is provided at one end in the longitudinal direction of the second transport screw 23b2 (the left-right direction in FIG. 3) and above the second transport screw 23b2 (second transport path B2). .
The inlet seal 23j is a thin sheet-like member formed of a flexible material such as polyurethane foam, and is disposed so as to be in sliding contact with the surface of the photosensitive drum 21 in the longitudinal direction at a position upstream of the developing region. Has been. The casing member 23i to which the inlet seal 23j is attached is held by the developing case 23h via the doctor blade 23d so as to cover a part of the outer peripheral surface of the developing roller 23a in the circumferential direction.
In the present embodiment, the developing device 23 is connected to a developing drive motor (not shown) while being attached to the image forming apparatus 1, and the developing drive motor is controlled by the control unit. By being driven, the developing roller 23a and the conveying screws 23b1 and 23b2 are rotationally driven.

Hereinafter, the cleaning device 25 that also functions as a lubricant supply device will be described in detail.
Referring to FIG. 2, the cleaning device 25 (lubricant supply device) supplies a lubricant onto the photosensitive drum 21 with a foamed elastic layer (surface layer) slidably contacting the photosensitive drum 21 around the outer peripheral surface. Lubricant supply roller 25b as a lubricant supply rotating body, solid lubricant 25c slidably in contact with lubricant supply roller 25b (foaming elastic layer), and urging for urging the solid lubricant 25c toward the lubricant supply roller 25b A compression spring 25d as a member, and a cleaning blade that also functions as a thinning blade (leveling blade) that makes contact with the photosensitive drum 21 and thins (uniformizes) the lubricant supplied onto the photosensitive drum 21 25a, etc.
The lubricant supply roller 25b is disposed on the upstream side in the rotation direction of the photosensitive drum 21 with respect to the cleaning blade 25a and on the downstream side in the rotation direction of the photosensitive drum 21 with respect to the primary transfer nip portion.

The lubricant supply roller 25 b is a roller member in which a foamed elastic layer made of foamed polyurethane (urethane foam) is formed on a core metal, and the foamed elastic layer is in contact with the surface of the photosensitive drum 21. 2 clockwise. As a result, the lubricant is supplied from the solid lubricant 25c to the photosensitive drum 21 via the lubricant supply roller 25b. That is, the lubricant supply roller 25b is disposed so as to be in sliding contact with the solid lubricant 25c and the photosensitive drum 21, and the lubricant supply roller 25b rotates to scrape the lubricant from the solid lubricant 25c. The lubricant is applied on the photosensitive drum 21.
A compression spring 25d is disposed behind the solid lubricant 25c in order to eliminate contact unevenness between the lubricant supply roller 25b and the solid lubricant 25c, and the solid lubricant 25c is placed on the lubricant supply roller 25b. Energized.

Here, the solid lubricant 25c is formed by containing an inorganic lubricant in fatty acid metal zinc. Moreover, as fatty acid metal zinc, what contains at least zinc stearate is preferable. Further, as the inorganic lubricant, at least one of talc, mica, and boron nitride can be used, and boron nitride is particularly preferable.
Zinc stearate is a typical lamellar crystal powder. A lamellar crystal has a layered structure in which amphiphilic molecules are self-organized, and when a shearing force is applied, the crystal breaks along the layers and is slippery. Accordingly, the surface of the photosensitive drum 21 can be made to have low friction. That is, the surface of the photosensitive drum 21 can be effectively covered with a small amount of lubricant by the lamellar crystal that uniformly receives the shearing force and covers the surface of the photosensitive drum 21. Then, the surface of the photosensitive drum 21 is covered relatively evenly and can be well protected from electrical stress in the charging process.
Further, by using an inorganic lubricant having a plate-like structure such as boron nitride, it is difficult for toner to slip through the cleaning blade 25a, and the charging unit 22 (charging roller) can be made difficult to get dirty.

The cleaning blade 25 a that also functions as a thinning blade is obtained by holding a plate-like member made of a rubber material such as urethane rubber, hydrin rubber, silicone rubber, or fluorine rubber on a holding plate, and the surface of the photosensitive drum 21. At a predetermined angle and a predetermined pressure. The lubricant supplied onto the photosensitive drum 21 by the lubricant supply roller 25b is uniformly and appropriately thinned on the photosensitive drum 21 by the cleaning blade 25a.
When the solid lubricant 25c is applied to the surface of the photosensitive drum 21 via the lubricant supply roller 25b, a powdery lubricant is applied to the surface of the photosensitive drum 21, but in this state, lubricity is maintained. Therefore, the cleaning blade 25a functions as a member for thinning and uniformizing the lubricant. The cleaning blade 25a forms a lubricant film on the photosensitive drum 21, and the lubricant exhibits its lubricity sufficiently.

Hereinafter, the configuration and operation of the developing device 23, which are characteristic in the present embodiment, will be described in detail with reference to FIG.
As shown in FIG. 4A, the developing device 23 in the present embodiment is provided with an anti-sticking agent K that is harder to stick to the surface of the developing roller 23a (developer carrier) than the toner T at the time of shipment. The developer G is accommodated in the developing device 23 in a state where it is removably applied to the surface of 23a. That is, in the present embodiment, the anti-sticking agent K is applied to the surface of the developing roller 23a instead of shipping the developer G in the first and second transport paths B1 and B2 of the developing device 23. In the attached state, the developer G (toner T and carrier C) is stored in the first and second transport paths B1 and B2.

  Specifically, as shown in FIG. 4A, when the developing device 23 is shipped from a factory or the like, the first anti-sticking agent K is adhered to the surface of the developing roller 23a so as to be rubbed lightly. The developer G is preset in the second transport paths B1 and B2. Here, since the anti-sticking agent K is not a magnetic substance and is not carried on the surface of the developing roller 23a by a magnetic force like the carrier C, it is carried on the developing roller 23a with a relatively weak holding force.

  The developing device 23 is shipped in such a state that the surface of the developing roller 23a is covered with the anti-sticking agent K, so that the developing device 23 is shipped from the factory or the like until the user arrives. Toner T (developer G) directly on the surface of the developing roller 23a, even when the toner is transported alone or when the developing device 23 is transported in the state where it is mounted on the image forming apparatus 1. ) Is hardly attached. Therefore, even when a low-melting toner is used as the toner T or when the developing device 23 is exposed to a high-temperature and high-humidity environment by sea transportation, the surface of the developing roller 23a is exposed. The trouble that the toner T adheres can be reliably reduced. For this reason, it is possible to prevent a problem that the density unevenness image is generated by the toner T adhering to the surface of the developing roller 23a.

Furthermore, in the present embodiment, since the developer G is stored in advance in the first and second transport paths B1 and B2 of the developing device 23 at the time of shipment, the user or serviceman is provided. Therefore, it is not necessary to perform the work of filling the developing device 23 with the developer G at the time of arrival, and the work time at the time of arrival is shortened.
Since the anti-sticking agent K applied to the developing roller 23a at the time of shipment is carried on the surface of the developing roller 23a with a relatively weak holding force, as shown in FIG. 4B, initial adjustment at the time of arrival is performed. When the developing device 23 is driven as a mode, it is separated from the developing roller 23a and mixed with the developer G in the first and second transport paths B1 and B2, and is fixed to the surface of the developing roller 23a. The developer G is carried so as to replace the inhibitor K. Therefore, the work of manually wiping off the anti-adhesive agent K applied to the developing roller 23a at the time of arrival becomes unnecessary, and the above-described effect of shortening the operation time at the time of arrival is maintained.
In the present embodiment, the effects described above are achieved with a relatively simple configuration without installing a seal member or a preset case.

Here, in the present embodiment, the anti-sticking agent K applied to the surface of the developing roller 23 a at the time of shipment is a substance having a melting point or glass transition point higher than that of the toner T, and is accommodated in the developing device 23. A substance contained in the developer G or a substance contained in a lubricant supplied to the surface of the photosensitive drum 21 by a lubricant supply device (cleaning device 25) is preferable.
The phenomenon that the toner T adheres to the surface of the developing roller 23a is caused by melting or glass transition of a part of the toner T in the developer G carried on the developing roller 23a in a high temperature and high humidity environment. Is. For this reason, a substance having a melting point or glass transition point larger than that of the toner T is carried on the surface of the developing roller 23a as the anti-sticking agent K, so that the anti-sticking agent K itself is exposed to a high-temperature and high-humidity environment. The problem of sticking can be suppressed.
Further, as described above, the anti-sticking agent K is separated from the developing roller 23a and mixed with the developer G inside the developing device 23 by performing the initial adjustment mode at the time of arrival. It is necessary that the image does not affect the image in the development process (or image forming process). The substance contained in the developer G and the substance contained in the lubricant supplied to the surface of the photosensitive drum 21 are originally formed so as not to affect the image. By using the substance as the anti-sticking agent K, it is possible to prevent the occurrence of abnormal images due to the anti-sticking agent K.

Specifically, in the present embodiment, as the anti-sticking agent K, a toner having a higher melting point than the toner T (the toner T in the developer G and the toner T in the toner bottle 33) (high melting point toner). , Zinc stearate (ZnST), iodine nitride (boron nitride), silicon dioxide (silica), or aluminum oxide (alumina) is used.
The high melting point toner is formed of almost the same components as the toner T in the developer G except for the melting points, and the amount of the anti-sticking agent K applied to the developing roller 23a is the same as that of the toner T in the developer G. Since the amount is extremely small as compared with the above, even if a high-melting toner is contained in the developer G, there is almost no problem on the image. Further, since the high melting point toner is a substance which is literally difficult to dissolve in the high temperature and high humidity environment as compared with the toner T in the developer G, it is suitable as the anti-sticking agent K.
As described above, zinc stearate and iodine nitride are materials used as components of the solid lubricant 23c, and are difficult to adhere to the surface of the developing roller 23a.
Silicon dioxide and aluminum oxide are substances that are used as external additives in the developer G in order to improve the fluidity and chargeability of the toner T, and are substances that are difficult to adhere to the surface of the developing roller 23a. Suitable as agent K.

The inventor of the present application, as Example 1, Example 2, and Comparative Example, left the developing device 23 set to the respective conditions up and down, left and right, left in an environment of 50 degrees temperature and 30% relative humidity for 48 hours, Immediately thereafter (1), after that, when the developing roller 23a is rotated by one revolution (2), and when the developing roller 23a is further rotated by ten revolutions (3), development is performed at respective timings. An experiment was conducted to visually observe the presence or absence of toner adhesion on the roller 23a.
In the developing device 23 in Example 1, 0.1 g of zinc stearate as the anti-sticking agent K is applied to the developing roller 23a and the developer G is preset in the developing device 23. In the developing device 23 in the second embodiment, 0.1 g of high-melting toner is applied to the developing roller 23a as the anti-sticking agent K, and the developer G is preset in the developing device 23. The developing device 23 in the comparative example presets the developer G inside the developing device 23 without applying the anti-sticking agent K to the developing roller 23a.
As a result of such an experiment, in the comparative example, it was confirmed that toner fixation occurred at all timings (1) to (3). In contrast, in Example 2, although the occurrence of toner fixation was confirmed at the timing (1), the occurrence of toner fixation was not confirmed at the timings (2) and (3). In Example 1, the occurrence of toner fixation was not confirmed at all timings (1) to (3).
Also from these experimental results, the effects of the present invention described above can be confirmed.

Here, in the present embodiment, before the normal development process is performed at the time of arrival, the developing device 23 is driven in a state of being mounted on the image forming apparatus main body 1, and the anti-sticking agent K is applied to the developing roller 23a. The developer G is agitated and mixed with the developer G stored (preset) inside the developing device 23.
Specifically, when the main power supply of the image forming apparatus 1 is turned on for the first time with the developing device 23 attached to the image forming apparatus 1 at the time of arrival, first, the developing drive motor is operated to develop the developing apparatus 23. (Developing roller 23a, transport screws 23b1, 23b2) are driven ("initial adjustment mode" is executed). As a result, the anti-sticking agent K carried on the developing roller 23a is shaken off from the developing roller 23a to the first transport path B1, and the developer G (toner) accommodated in the first and second transport paths B1 and B2. It will be stirred and mixed while circulating with T and carrier C).

Furthermore, in the present embodiment, the developing device 23 is driven in a state of being mounted on the image forming apparatus main body 1 and received in the developing device 23 at the time of arrival and before the normal developing process is performed. The toner image is formed so that the anti-sticking agent K stirred and mixed with the developer G is supplied to the photosensitive drum 21 together with the toner T.
Specifically, in the initial adjustment mode, a charging process, an exposure process, and a developing process are performed so that a predetermined patch pattern (toner image) is formed on the photosensitive drum 21, and the developing device 23 is fixed together with the toner T. The inhibitor K is discharged and adheres to the photosensitive drum 21. Then, after the toner T and the anti-sticking agent K adhering to the photosensitive drum 21 pass through the primary transfer nip portion in a state where the application of the primary transfer bias to the primary transfer bias roller 24 is turned off, It is collected by the cleaning device 25. Then, after the sticking preventing agent K has been discharged from the developing device 23, the “initial adjustment mode” is ended. Thereafter, calibration (output adjustment) of the known toner concentration sensor 23g (magnetic permeability sensor) and known process control (adjustment control of image forming conditions such as charging bias and developing bias) are performed as a warm-up operation. After that, a normal image forming operation can be executed.

In the case where a high melting point toner (a toner having a higher melting point than that of toner T) is used as the anti-sticking agent K, the developing device is at the time of arrival and before the normal development process is performed. 23 is driven in a state where it is mounted on the image forming apparatus main body 1, and the anti-sticking agent K is detached from the surface of the developing roller 23a, and stirred and mixed with the developer G contained (preset) in the developing device 23. After the normal development process is started, the cumulative driving time of the developing device 23 reaches a predetermined value (until the high melting point toner in the developing device 23 is sufficiently discharged). The fixing temperature during the fixing process can be controlled to be set higher than the normal temperature.
By performing such control, when the toner image formed of the high melting point toner is fixed on the recording medium P as a fixed image in the fixing device 66, the fixing temperature (the temperature at which the toner image is heated / melted) is increased. It is possible to prevent a problem that the fixing defect is low.

In the present embodiment, the present invention is applied to the two-component developing type developing device 23 using the two-component developer containing the carrier C in addition to the toner T. However, the developing device to which the present invention is applied. However, the present invention is not limited to this, and the present invention is also applied to a developing device of a one-component developing system using a one-component developer composed only of toner T (including one containing an additive or the like). can do.
Specifically, as a modified example, as shown in FIG. 5A, a developing roller 23a that abuts on the photosensitive drum 21 (a conductive elastic layer is formed on a cored bar), and a developing roller 23a. A well-known supply roller 23x for supplying toner T, a doctor blade 23d for thinning the toner T carried on the developing roller 23a, a stirring roller 23y for stirring and transporting the toner T in the developing device 23, and the like are installed. The present invention can also be applied to the developing device 23 of the one-component development system. As shown in FIG. 5B, when such a developing device 23 is shipped, the toner T (one-component development) is placed inside the developing device 23 with the anti-sticking agent K applied to the surface of the developing roller 23a. (Agent) can be shipped in a stored (preset) state.
Even in such a case, substantially the same effect as that of the present embodiment can be obtained.

As described above, the developing device 23 according to the present exemplary embodiment has the anti-sticking agent K that is harder to adhere to the surface of the developing roller 23a (developer carrier) than the toner T at the time of shipment on the surface of the developing roller 23a. The developer G is accommodated in the developing device 23 in a state where it is detachably applied.
As a result, even if the developer G is shipped in a state where the developer G is housed in the developing device 23 without installing a seal member or a preset case with a relatively simple configuration, the developing roller 23a is transported until it is loaded. It is difficult to cause a problem that the toner T adheres to the surface of the toner, and it is difficult to cause a problem such as an image density defect in the development process after arrival.

In the present embodiment, the developing device 23 is configured separately from the process cartridge 20. On the other hand, the developing device 23 can be integrated with other components of the process cartridge 20 as a component of the process cartridge 20.
In such a case, the same effect as that of the present embodiment can be obtained and the maintainability of the image forming unit is improved.
In the present application, “process cartridge” means a charging device (charging unit) for charging an image carrier, a developing device (developing unit) for developing a latent image formed on the image carrier, and an image carrier. It is defined as a unit configured such that at least one of the cleaning device (cleaning unit) for cleaning the top and the image carrier are integrated and detachable from the image forming apparatus main body.

In the present embodiment, one developing roller 23a is installed as a developer carrying member, two conveying screws 23b1 and 23b2 are juxtaposed in the horizontal direction as a plurality of conveying members, and the doctor blade 23d is a developing roller. Although the present invention is applied to the developing device 23 installed so as to face the upper side of 23a, the developing device to which the present invention is applied is not limited to this.
For example, one developing roller is installed as a developer carrier, two conveying screws are arranged in parallel in the horizontal direction as a plurality of conveying members, and a doctor blade is installed so as to face the lower side of the developing roller. Of course, the present invention can also be applied to these developing devices.
Further, a known developing device in which two conveying screws as a plurality of conveying members are arranged in parallel in the vertical direction so as to face the developing roller, respectively, or a plurality of developing rollers as a developer carrying member to face the photosensitive drum. Naturally, the present invention can also be applied to a known developing device installed in the above and a known developing device in which three or more conveying screws are installed as a plurality of conveying members.

  It should be noted that the present invention is not limited to the present embodiment, and it is obvious that each embodiment can be modified as appropriate within the scope of the technical idea of the present invention, other than suggested in each embodiment. is there. In addition, the number, position, shape, and the like of the constituent members are not limited to the present embodiment, and the number, position, shape, and the like suitable for implementing the present invention can be achieved.

1 image forming apparatus (image forming apparatus main body),
20, 20Y, 20M, 20C, 20BK Process cartridge,
21 Photosensitive drum (image carrier),
23, 23Y, 23M, 23C, 23BK Developing device (developing unit),
23a Development roller (developer carrier),
23b1 first conveying screw (conveying member),
23b2 second conveying screw (conveying member),
23d doctor blade (developer regulating member),
25 Cleaning device (lubricant supply device),
66 fixing device,
G developer (two-component developer),
C carrier, T toner, K anti-sticking agent.

JP 2007-41209 A JP2013-33077A JP2013-148813A

Claims (8)

A developing device for developing a latent image formed on the surface of an image carrier, in which a developer having at least toner is contained,
A developer carrier that bears a developer facing or in contact with the image carrier,
At the time of shipment, the developer is fixed inside the developing device in a state in which an anti-adhesive agent that is less likely to adhere to the surface of the developer carrying body than the toner is detachably applied to the surface of the developer carrying body. A developing device, wherein the developing device is accommodated so as to come into contact with the developer carrying member coated with an inhibitor .   The anti-sticking agent is a substance having a melting point or a glass transition point larger than that of the toner, and the substance contained in the developer contained in the developing device or the lubricant supplying device may be used for the image carrier. 2. The developing device according to claim 1, wherein the developing device is a substance contained in a lubricant supplied to the surface.   3. The toner according to claim 1, wherein the anti-sticking agent is one of toner having a melting point higher than that of the toner, zinc stearate, iodine nitride, silicon dioxide, and aluminum oxide. Development device.   At the time of arrival and before the normal development process is performed, the developing device is driven in a state of being mounted on the main body of the image forming apparatus, and the anti-sticking agent is detached from the surface of the developer carrying member, The developing device according to any one of claims 1 to 3, wherein the developing device is stirred and mixed with a developer contained in the developing device.   At the time of arrival and before the normal development process is performed, the developing device is driven in a state of being mounted on the image forming apparatus main body, and the developer agitated and mixed with the developer contained inside the developing device. The developing device according to claim 4, wherein a toner image is formed such that an anti-sticking agent is supplied to the image carrier together with the toner. The anti-sticking agent is a toner having a higher melting point than the toner,
5. The fixing temperature in the fixing step is set higher than a normal one until the cumulative driving time of the developing device reaches a predetermined value after the normal developing step is started. The developing device described. A process cartridge that is detachably attached to the image forming apparatus main body,
7. A process cartridge comprising the developing device according to claim 1 and the image carrier integrally.   An image forming apparatus comprising the developing device according to claim 1 and the image carrier.

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