This patent application is based on and claims priority pursuant to 35 U.S.C. § 119(a) to Japanese Patent Application No. 2018-191463, filed on Oct. 10, 2018, in the Japan Patent Office, the entire disclosure of which is hereby incorporated by reference herein.
Embodiments of the present disclosure generally relate to an image forming apparatus such as a copier, a printer, a facsimile machine, or a multifunction peripheral (MFP) having at least two of such capabilities.
There are image forming apparatuses, such as copiers, printers, and the like, in which a developing device is removably installed. The developing device includes a stirring rotator to stir a developer contained therein.
Embodiments of the present disclosure describe an improved image forming apparatus that includes a developing device including at least one stirring rotator configured to stir a developer in the developing device, a driver configured to drive the at least one stirring rotator in forward and reverse rotation, a device detector configured to detect whether the developing device is set in the image forming apparatus, and control circuitry configured to execute a warm-up operation. In the warm-up operation, the driver drives the at least one stirring rotator alternately in the reverse rotation and the forward rotation in response to a detection of setting of the developing device in the image forming apparatus by the device detector and a detection of a predetermined condition.
A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:
The accompanying drawings are intended to depict embodiments of the present disclosure and should not be interpreted to limit the scope thereof. The accompanying drawings are not to be considered as drawn to scale unless explicitly noted. In addition, identical or similar reference numerals designate identical or similar components throughout the several views.
Embodiments of the present disclosure are described in detail with reference to drawings. It is to be understood that identical or similar reference numerals are assigned to identical or corresponding components throughout the drawings, and redundant descriptions are omitted or simplified below as required.
In describing embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that have the same function, operate in a similar manner, and achieve a similar result.
As used herein, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
It is to be noted that the suffixes Y, M, C, and K attached to each reference numeral indicate only that components indicated thereby are used for forming yellow, magenta, cyan, and black toner images, respectively, and hereinafter may be omitted when color discrimination is not necessary.
With reference to
In
The image forming apparatus 1 also includes photoconductor drums 11Y, 11M, 11C, and 11BK as image bearers, developing devices 13, primary transfer rollers 14, and an intermediate transfer belt 17. Electrostatic latent images are formed on surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK and developed into toner images of yellow, magenta, cyan, and black by the developing devices 13. The toner images on the surfaces of the photoconductor drums 11Y, 11M, 11C, and 11BK are transferred to and superimposed on the intermediate transfer belt 17 by the primary transfer rollers 14, thereby forming a multicolor toner image on the intermediate transfer belt 17.
The image forming apparatus 1 further includes a secondary transfer roller 18, a fixing device 20, and toner containers 28. The secondary transfer roller 18 transfers the multicolor toner image on the intermediate transfer belt 17 onto the sheet P. The fixing device 20 fixes the multicolor toner image (unfixed image) on the sheet P. The toner containers 28 contain yellow, magenta, cyan, and black toners to supply the toners to the developing devices 13.
A description is provided below of operation of the image forming apparatus 1 when forming a normal color image.
It is to be noted that
A conveyance roller of the document conveyance device 3 conveys a document on a document table onto an exposure glass of the document scanner 4. Then, the document scanner 4 optically scans document image data.
More specifically, the document scanner 4 scans an image of the document on the exposure glass with light emitted from an exposure device. The light reflected from the surface of the document is directed onto a color sensor via mirrors and lenses to form multicolor image data of the scanned document. The multicolor document image data, which is decomposed into red, green, and blue (RGB) image data, is read by the color sensor and converted into electrical image signals. An image processor performs image processing (e.g., color conversion, color calibration, and spatial frequency adjustment) according to the image signals of the decomposed RGB image data, and thus image data for yellow, magenta, cyan, and black toner images are obtained.
The image data for yellow, magenta, cyan, and black toner images are sent to a writing device. The writing device directs a laser beam L (see
Meanwhile, the four photoconductor drums 11 rotate clockwise as illustrated in
The writing device emits the laser beam L from each of four light sources according to the image data. The respective laser beams L travel different optical paths for the different components of yellow, magenta, cyan, and black (an exposure process).
The laser beam L corresponding to the yellow component is directed onto the surface of the photoconductor drum 11Y that is the first from the left in
Similarly, the laser beam L corresponding to the magenta component is directed onto the surface of the photoconductor drum 11M that is the second from the left in
Then, the surface of the photoconductor drum 11 having the electrostatic latent image reaches a position opposite the developing device 13. The developing device 13 supplies toner of each color to the photoconductor drum 11 and develops the electrostatic latent image on the photoconductor drum 11 into a visible toner image (a development process).
Subsequently, the surfaces of the photoconductor drums 11 reach positions facing the intermediate transfer belt 17. The primary transfer rollers 14 are disposed at positions where the photoconductor drums 11 face the intermediate transfer belt 17 and in contact with an inner surface of the intermediate transfer belt 17, respectively. At the positions of the primary transfer rollers 14, the toner images on the photoconductor drums 11Y, 11M, 11C, and 11BK are transferred to and superimposed on the intermediate transfer belt 17, forming a multicolor toner image thereon (a primary transfer process).
After the primary transfer process, the surface of the photoconductor drum 11 reaches a position opposite a cleaning device 15. The cleaning device 15 collects untransferred toner remaining on the photoconductor drum 11 (a cleaning process).
Then, the surface of the photoconductor drum 11 passes through the discharger to complete a series of image forming processes performed on the photoconductor drum 11.
The multicolor toner image is formed on a surface of the intermediate transfer belt 17 by transferring and superimposing the respective single-color toner images formed on the photoconductor drums 11. Then, the intermediate transfer belt 17 carrying the multicolor toner image moves counterclockwise in
After the secondary transfer process, the surface of the intermediate transfer belt 17 reaches a position opposite a belt cleaning device. The belt cleaning device collects untransferred toner adhering to the intermediate transfer belt 17 to complete a sequence of transfer processes performed on the intermediate transfer belt 17.
The sheet P is conveyed from the sheet feeding device 7 via the registration roller pair 9 to the secondary transfer nip between the intermediate transfer belt 17 and the secondary transfer roller 18.
More specifically, a sheet feeding roller 8 feeds the sheet P from the sheet feeding device 7 that contains multiple sheets P, and the sheet P is then guided by a sheet guide to the registration roller pair 9. The sheet P that has reached the registration roller pair 9 is conveyed toward the secondary transfer nip, timed to coincide with the arrival of the multicolor toner image on the intermediate transfer belt 17.
Then, the sheet P carrying the multicolor toner image is conveyed to the fixing device 20. The fixing device 20 includes a fixing roller and a pressure roller pressing against each other. In a nip between the fixing roller and the pressure roller, the multicolor toner image is fixed on the sheet P.
After the fixing process, an output roller pair ejects the sheet P as an output image outside the image forming apparatus 1, and the ejected sheet P is stacked on the output tray 5. Thus, a series of the image forming processes is completed.
Next, an image forming unit of the image forming apparatus 1 is described in further detail below with reference to
It is to be noted that the suffixes Y, M, C, and BK of the photoconductor drum 11, the developing device 13, and the like are omitted in
With continued reference to
The photoconductor drum 11 as the image bearer in the present embodiment is a negatively-charged organic photoconductor and is rotated clockwise in
The charging device 12 is an elastic charging roller and can be formed by coating a core with an elastic layer of moderate resistivity, such as foamed urethane, that includes carbon black as conductive particles, a sulfuration agent, a foaming agent, and the like. The material of the elastic layer of moderate resistivity of the charging device 12 includes, but is not limited to, rubber such as urethane, ethylene-propylene-diene-polyethylene (EPDM), acrylonitrile butadiene rubber (NBR), silicone rubber, and isoprene rubber to which a conductive material such as carbon black or metal oxide is added to adjust the resistivity. Alternatively, foamed rubber including these materials may be used.
The cleaning device 15 includes a cleaning blade that slides over the surface of the photoconductor drum 11 and mechanically removes untransferred toner on the photoconductor drum 11.
The developing device 13 includes a developing roller 13a, serving as a developer bearer, opposed to the photoconductor drum 11 via a slight gap, and a development range (a development nip) where a magnetic brush formed on the developing roller 13a contacts the photoconductor drum 11 is formed in a portion where the developing roller 13a is opposed to the photoconductor drum 11. The developing device 13 contains a two-component developer G including toner T and carrier C. The developing device 13 develops the electrostatic latent image on the photoconductor drum 11 into a toner image. A detailed description of the configuration and operation of the developing device 13 is deferred.
With reference to
In the present embodiment, any toner can be used as the toner T in the developer G and the toner T in the toner container 28, and any carrier can be used as the carrier C in the developer G.
The developing device 13 of the image forming apparatus 1 is described in further detail below.
As illustrated in
The developing roller 13a includes a cylindrical sleeve 13a2 made of a nonmagnetic material and rotates counterclockwise in
Specifically, a scooping pole of the multiple magnetic poles acts on magnetic carrier C in the developer G, and thus the developer G contained in the supply path of the developing device 13 is partially scooped up on the developing roller 13a. A part of the developer G carried on the developing roller 13a is scraped off by the doctor blade 13c and returned to the supply path. The developer G passes through a doctor gap between the doctor blade 13c and the developing roller 13a where the scooping pole acts. Then, the grains of the developer G carried on the developing roller 13a stand on end on the developing roller 13a due to the magnetic force exerted by a main pole of the multiple magnetic poles, forming a magnetic brush in the development range and slidingly contact the photoconductor drum 11. Thus, the toner T in the developer G carried on the developing roller 13a adheres to the latent image formed on the photoconductor drum 11. After passing through the development range where the main pole acts, the developer G passes between an upper cover and the developing roller 13a by the magnetic force exerted by a conveyance pole of the multiple magnetic poles and is transported to a position corresponding to a developer release pole of the multiple magnetic poles. Then, at the position corresponding to the developer release pole, magnetic repulsion to separate the developer G from the developing roller 13a acts on the carrier C, and the developer G carried on the developing roller 13a after the development process is removed from the developing roller 13a. Then, the developer G drops into the collection path of the developing device 13 and is transported downstream by the second stirring screw 13b2 therein.
With reference to
In
The first and second stirring screws 13b1 and 13b2 stir the developer G contained in the developing device 13 while circulating the developer G in the longitudinal direction of the developing device (hereinafter also referred to as “developer conveyance direction”), perpendicular to the surface of the paper on which
The first stirring screw 13b1 as the stirring rotator for supplying the developer is opposed to the developing roller 13a and supplies the developer G to the developing roller 13a as indicated by white arrows illustrated in the part (b) of
The second stirring screw 13b2 as the stirring rotator for collecting the developer is disposed above the first stirring screw 13b1 and opposed to the developing roller 13a. The second stirring screw 13b2 horizontally transports the developer G that has been forcibly separated from the developing roller 13a by the developer release pole in the direction indicated by white arrows in the part (a) of
The developer G is transported from the downstream side of the supply path (hereinafter, also referred to as “a first transport path”) in which the first stirring screw 13b1 is disposed, through a first communication opening 13f, and to the collection path (hereinafter, also referred to as “a second transport path”) in which the second stirring screw 13b2 is disposed. The second stirring screw 13b2 transports the developer G downstream in the collection path (the second transport path) and to the upstream side of the supply path (the first transport path) through a second communication opening 13g (as indicated by alternate long and short dashed arrow in
The first and second stirring screws 13b1 and 13b2 are disposed so that axes of rotation of the first and second stirring screws 13b1 and 13b2 are substantially horizontal similar to the developing roller 13a and the photoconductor drum 11. Each of the first and second stirring screws 13b1 and 13b2 includes a screw shaft and a helical blade winding around the screw shaft.
A controller 50 controls the drive motor 51 to rotate the first and second stirring screws 13b1 and 13b2 along with the developing roller 13a. That is, the first and second stirring screws 13b1 and 13b2 and the developing roller 13a constitute a drive system with a gear train and are driven to rotate by the drive motor 51 as the driver.
Specifically, a coupling to which driving force is directly transmitted from the drive motor 51 is disposed on a shaft on one end of the developing roller 13a in the longitudinal direction of the developing roller 13a (i.e., the direction perpendicular to the paper on which
In the present embodiment, the drive motor 51 as the driver to drive the developing device 13 is provided independently of the drive motor to rotate the photoconductor drum 11. The drive motor 51 is a motor of forward and reverse bi-directional rotation type, and is configured to drive the developing device 13 in reverse, which is described in detail later.
An inner wall (a partition) 13d of the developing device 13 separates the first transport path (the supply path) in which the first stirring screw 13b1 is disposed and the second transport path (the collection path) in which the second stirring screw 13b2 is disposed.
With reference to
With reference to
It is to be noted that a paddle or a screw winding in the direction opposite to the helical blade of the first stirring screw 13b1 may be provided on a downstream portion of the first stirring screw 13b1 to facilitate conveyance of the developer G at a position corresponding to the first communication opening 13f, which is conveyance from the supply path to the collection path against the direction of gravity.
This configuration provides the circulation path through which the developer G is circulated in the longitudinal direction by the first and second stirring screws (the stirring rotators) 13b1 and 13b2 in the developing device 13. That is, when the developing device 13 operates, the developer G contained therein flows in the developer conveyance direction indicated by the broken arrows illustrated in
The magnetic sensor to detect the toner concentration in the developer G circulated in the developing device 13 is disposed in the collection path (the second transport path). Based on the toner concentration detected by the magnetic sensor, the fresh toner T is supplied from the toner container 28 to the developing device 13 through the toner supply inlet 13e disposed near the first communication opening 13f.
Additionally, with reference to
It is to be noted that the position of the toner supply inlet 13e is not limited to inside the collection path (the second transport path) but can be disposed above an upstream portion of the supply path, for example.
The configuration and operation of the image forming apparatus 1 according to the present embodiment are described in further detail below.
As described above with reference to
The replaceable developing device 13 is removably installed in the image forming apparatus 1 and replaced with a new one (which may be a recycled product) in a predetermined replacement cycle. When the developing device 13 is installed (or set) in the image forming apparatus 1, the drive motor (the driver) 51 can transmit the driving force to the developing device 13. When the developing device 13 is removed from the image forming apparatus 1, the drive motor (the driver) 51 does not transmit the driving force to the developing device 13.
As described above, the developing device 13 includes the first and second stirring screws (conveyance screws) 13b1 and 13b2 as the stirring rotators to stir the developer G therein and the developing roller 13a opposed to the photoconductor drum (the image bearer) 11.
The drive motor (the driver) 51 rotates the developing roller 13a along with the first and second stirring screws (the stirring rotators) 13b1 and 13b2.
Here, the drive motor 51 as the driver drives the first and second stirring screws 13b1 and 13b2 as the stirring rotators in forward and reverse rotation. Specifically, the drive motor (the driver) 51 in the present embodiment is the forward and reverse bi-directional motor, and the controller 50 causes the drive motor 51 to rotate the first and second stirring screws 13b1 and 13b2 along with the developing roller 13a forward as described in
As illustrated in
Specifically, the developing device 13 includes a radiofrequency identification (RFID) tag 13r as a data storage medium. A reader/writer 55 is secured to the image forming apparatus 1 at a position opposite the RFID tag 13r of the developing device 13 set in the image forming apparatus 1. The RFID tag 13r stores data such as manufacturing date, manufacturing lot, usage history, operation time, recycling history, and the like, regarding the developing device 13, and such data are read and written by the reader/writer 55 as appropriate and used for various controls.
In particular, in the present embodiment, the controller 50 determines whether the developing device 13 is set in the image forming apparatus 1 depending on whether the reader/writer 55 detects the signal of the RFID tag 13r.
Further, in the present embodiment, when the developing device 13 has been used in any of the image forming apparatuses, the reader/writer 55 writes data regarding the usage history in the RFID tag 13r. Therefore, the controller 50 determines whether the developing device 13 set in the image forming apparatus 1 is new (including recycled) or not by the reader/writer 55. That is, the reader/writer 55 as the device detector can detect the state in which an unused developing device 13 is set in the image forming apparatus 1 for the first time.
In the present embodiment, when the reader/writer (the device detector) 55 detects that the developing device 13 being in a predetermined condition is set in the image forming apparatus 1, the controller 50 as control circuitry executes the warm-up operation (warming up mode) in which the drive motor (the driver) 51 drives the first and second stirring screws (stirring rotators) 13b1 and 13b2 alternately in the reverse rotation and the forward rotation.
Specifically, in the present embodiment, the warm-up operation is performed when the reader/writer (the device detector) 55 detects that the unused developing device 13 is set in the image forming apparatus 1 for the first time. That is, when the reader/writer 55 detects that a new developing device 13, which has not been used in any image forming apparatus, is first set in the image forming apparatus 1, the drive motor 51 repeatedly rotates in reverse and forward, and the developing device 13 (the developing roller 13a, the first stirring screw 13b1, and the second stirring screw 13b2) is driven in the reverse and forward directions before the image forming operation (the development process).
The reason for performing such “warm-up operation (warming up mode)” is to smooth the developer G leant to one side in the developing device 13 into a normal state before starting the image forming operation (image formation). As a result, the satisfactory image forming operation (the development process) can be performed.
However, as illustrated in
On the other hand, in the warm-up operation according to the present embodiment, the first and second stirring screws 13b1 and 13b2 is not driven in the forward rotation immediately after the new developing device 13 is set in the image forming apparatus 1. Since the reverse rotation and the forward rotation of the first and second stirring screws 13b1 and 13b2 are alternately repeated, an uneven distribution of the developer G in the developing device 13 can be eliminated without abruptly increasing the starting torque of the drive motor 51. That is, the developer G in the developing device 13 is leveled to a normal state without the lock of the drive motor 51. Specifically, when the first and second stirring screws 13b1 and 13b2 are rotated in reverse in the state illustrated in
Note that, if only the reverse rotation of the first and second stirring screws 13b1 and 13b2 continues during the warm-up operation, the developer G is likely to overflow from the toner supply inlet 13e. Therefore, as in the present embodiment, the first and second stirring screws 13b and 13b2 are driven alternately in the reverse rotation and the forward rotation.
Here, in the present embodiment, in the warm-up operation (warming up mode) described above, the first and second stirring screws (stirring rotators) 13b1 and 13b2 are driven alternately in the order of the reverse rotation and the forward rotation, not in the order of the forward rotation and the reverse rotation. That is, the developing device 13 set in the image forming apparatus 1 is first driven in the reverse rotation as illustrated in
Since the first and second stirring screws 13b1 and 13b2 are first driven in the reverse rotation, the lock of the drive motor 51 is less likely to occur as compared with the case in which the first and second stirring screws 13b1 and 13b2 are initially rotated forward. That is, as illustrated in
Further, in the warm-up operation according to the present embodiment, the controller 50 can control so that the time T1 for driving the first and second stirring screws (stirring rotators) 13b1 and 13b2 in the reverse rotation is longer than the time T2 for driving in the forward rotation (i.e., T1>T2).
With this control, the developer G in the developing device 13 can be smoothed to the normal state in a short time as compared with the case in which the reverse rotation time T1 is set to the forward rotation time T2 or less.
Note that, when the reverse rotation time T1 is set longer than the forward rotation time T2, the reverse rotation time T1 is preferably set within a range in which the developer G does not overflow from the toner supply inlet 13e.
As illustrated in
Specifically, first, the drive motor 51 rotates in reverse, and the first and second stirring screws 13b1 and 13b2 along with the developing roller 13a are driven in the reverse rotation for a predetermined time T1 (step S2). Subsequently, the drive motor 51 rotates forward, and the first and second stirring screws 13b1 and 13b2 along with the developing roller 13a are driven in the forward rotation for a predetermined time T2 (step S3). Then, such a reverse and forward rotation cycle is performed the predetermined number of times (N times) (step S4), and then the warm-up operation is ended.
As illustrated in
In the first variation, when the reader/writer (the device detector) 55 detects that the developing device 13 is set in the image forming apparatus 1, if the torque detected by the torque detector 52 exceeds a predetermined threshold value A, the controller 50 performs the warm-up operation as in the present embodiment. For example, the predetermined threshold value A is stored in a memory, for example, by a manufacturer based on empirical data.
Specifically, in the first variation, as illustrated in
As a result, when the controller 50 determines that the torque exceeds the predetermined threshold value A, the controller 50 performs the warm-up operation on the assumption that the developer G in the developing device 13 is extremely leant to one side (steps S2 to S4). On the other hand, when the controller 50 determines that the torque does not exceed the predetermined threshold value A, on assumption that the developer G in the developing device 13 is hardly leant to one side (i.e., leveled evenly), the controller 50 does not performs the warm-up operation, and the process is ended as is.
In such a control according to the first variation, similar effects to those of the above-described embodiments are also attained. In particular, in the first variation, since the warm-up operation is performed only when the controller 50 determines that the developer G in the developing device 13 is extremely leant to one side. Thus, the warm-up operation does not make a user wait when not needed.
Similarly to the first variation, the image forming apparatus 1 according to the second variation also includes the torque detector 52 that detects the torque applied when the first and second stirring screws 13b1 and 13b2 rotate.
In the second variation, when the torque detected by the torque detector 52 is large, an execution time of the warm-up operation is longer than when the torque detected by the torque detector 52 is small.
Specifically, in the second variation, as illustrated in
Then, the controller 50 performs the warm-up operation for the execution time (N times) determined in step S21 (steps S2 to S4).
In such a control according to the second variation, similar effects to those of the above-described embodiments are also attained. In particular, in the second variation, since the execution time of the warm-up operation is varied according to the magnitude of the uneven distribution of the developer G in the developing device 13, the controller 50 performs the warm-up operation for an appropriate time. As a result, the problem that the warm-up operation makes a user wait unnecessarily is prevented.
As illustrated in
Specifically, similarly to the above-described embodiments, the developing devices 13Y, 13M, 13C, and 13BK for four colors (i.e., yellow, magenta, cyan, and black) are removably installed in the image forming apparatus 1 according to the third variation. The first drive motor 51A as one driving source drives the some of the plurality of developing devices (i.e., the three developing devices 13Y, 13M, and 13C for colors) in the forward rotation and the reverse rotation via a plurality of gear trains. On the other hand, the second drive motor 51B different from the first drive motor 51A drives the other of the plurality of developing devices (i.e., the one developing device 13BK for black) in the forward rotation and the reverse rotation via a gear train.
In the third variation, an execution time (N times) of the warm-up operation performed in the three developing devices 13Y, 13M, and 13C by the first drive motor (the first driver) 51A is longer than an execution time (N times) of the warm-up operation performed in the one developing device 13BK by the second drive motor (the second driver) 51B.
The load applied to the first drive motor 51A that drives the three developing devices 13Y, 13M, and 13C is originally higher than the load applied to the second drive motor 51B that drives the one developing device 13BK. For this reason, if the developer G is extremely leant to one side in the developing devices 13Y, 13M, and 13C, the first drive motor 51A is likely to lock. On the other hand, in the third variation, since the execution time of the warm-up operation of the three developing devices 13Y, 13M, and 13C is set to be long, such a problem is less likely to occur.
In the third variation, similar effects to those of the above-described embodiments are also attained.
As described above, in the image forming apparatus 1 according to the above-described embodiments, when the reader/writer (the device detector) 55 detects that the developing device 13 being in a predetermined condition is set in the image forming apparatus 1, the controller 50 as control circuitry executes the warm-up operation in which the drive motor 51 as a driver drives the first and second stirring screws 13b1 and 13b2 as stirring rotators alternately in the reverse rotation and the forward rotation.
As a result, in the developing device 13 set in the image forming apparatus 1, the drive motor 51 is less likely to lock due to the increase in the load for driving the first and second stirring screws 13b1 and 13b2.
Therefore, according to the present disclosure, an image forming apparatus can be provided to prevent a driver from locking due to an excessive load to rotate a stirring rotator in a developing device installed in the image forming apparatus.
It is to be noted that, in the above-described embodiments, the second stirring screw 13b2 serving as the collection screw is disposed above the first stirring screw 13b1 serving as the supply screw, and the doctor blade 13c is disposed below the developing roller 13a in the two-component type developing device 13. The present disclosure can be applied to a developing device employing two-component development method in which a second stirring screw serving as a collection screw is disposed below a first stirring screw serving as a supply screw and a doctor blade is disposed above a developing roller, or another developing device employing two-component development method in which a plurality of conveyors is horizontally arranged in parallel. Further, the present disclosure can be applied to yet another developing device employing one-component development method using only toner without carrier as a developer. However, the configuration of the developing device to which the present disclosure is applied is not limited to the above-described configurations.
In the above-described embodiments, the present disclosure is applied to the developing device 13 in which the developing roller 13a is disposed across a gap from the photoconductor drum 11 as the image bearer. Alternatively, the present disclosure can be applied to a developing device employing contact type one-component development method in which a developing roller contacts an image bearer.
In such configurations, effects similar to those described above are also attained.
Further, the present disclosure is applied to the image forming apparatus 1 in which the developing device 13 is separately installed. Alternatively, the present disclosure is not limited to the above described configuration and can be applied to an image forming apparatus in which a developing device constitutes a process cartridge together with other components. In this case, workability of maintenance of the image forming unit can be improved.
It is to be noted that the term “process cartridge” used in the present disclosure means a unit including an image bearer and at least one of a charger to charge the image bearer, a developing device to develop latent images on the image bearer, and a cleaner to clean the image bearer united together and designed to be removably installed together in the image forming apparatus.
Further, in the above-described embodiments, when the warm-up operation is performed, the first and second stirring screws (stirring rotators) 13b1 and 13b2 are rotated in the forward direction or the reverse direction along with the developing roller 13a. However, the developing roller 13a may not be rotated, and only the first and second stirring screws (stirring rotators) 13b1 and 13b2 may be rotated in the forward direction or the reverse direction. In that case, a drive system for driving the developing roller 13a and a drive system for driving the first and second stirring screws 13b1 and 13b2 are provided independently of each other.
In such configurations, effects similar to those described above are also attained.
It is therefore to be understood that within the scope of the present disclosure, the present disclosure may be practiced otherwise than as specifically described herein. The above-described embodiments are illustrative and do not limit the present disclosure. Thus, numerous additional modifications and variations are possible in light of the above teachings. The number, position, and shape of the components described above are not limited to those embodiments described above. Desirable number, position, and shape can be determined to perform the present disclosure.
Any one of the above-described operations may be performed in various other ways, for example, in an order different from the one described above.
Each of the functions of the described embodiments may be implemented by one or more processing circuits or control circuitry. Processing circuitry includes a programmed processor, as a processor includes control circuitry. A processing circuit also includes devices such as an application specific integrated circuit (ASIC), DSP (digital signal processor), FPGA (field programmable gate array) and conventional circuit components arranged to perform the recited functions.
Number | Date | Country | Kind |
---|---|---|---|
JP2018-191463 | Oct 2018 | JP | national |
Number | Name | Date | Kind |
---|---|---|---|
5784669 | Miura | Jul 1998 | A |
6256469 | Taniyama | Jul 2001 | B1 |
20090214233 | Murauchi | Aug 2009 | A1 |
20100189455 | Kim | Jul 2010 | A1 |
20170293257 | Ohhira et al. | Oct 2017 | A1 |
20170351195 | Koshizuka et al. | Dec 2017 | A1 |
20180136586 | Tsuchiya et al. | May 2018 | A1 |
20180143568 | Ohhira et al. | May 2018 | A1 |
20190018343 | Oshikawa | Jan 2019 | A1 |
Number | Date | Country |
---|---|---|
8-137230 | May 1996 | JP |
2004-117387 | Apr 2004 | JP |
2006-162895 | Jun 2006 | JP |
2010-152098 | Jul 2010 | JP |
2013-205475 | Oct 2013 | JP |
2013-218300 | Oct 2013 | JP |
Number | Date | Country | |
---|---|---|---|
20200117119 A1 | Apr 2020 | US |