Image forming apparatus with guide mechanism for image writer

An image forming apparatus includes an apparatus housing having an opening and closing door, an attaching body, an image writer, and a guide mechanism. The guide mechanism moves the image writer in conjunction with opening and closing of the opening and closing door, guides the image writer to a write position upon closing the opening and closing door, and guides the image writer to a retracted position upon opening the opening and closing door. The guide mechanism has a first guide mechanism that moves the image writer along a first guide portion provided in the attaching body while the opening and closing door moves from the close position to an intermediate position, and a second guide mechanism that guides the image writer along a second guide portion provided in the apparatus housing while the opening and closing door moves from the intermediate position to the open position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2014-245960 filed Dec. 4, 2014.

BACKGROUND

Technical Field

SUMMARY

According to an aspect of the invention, there is provided an image forming apparatus including an apparatus housing that has an opening and closing door that opens and closes between a close position and an open position, an attaching body that includes an image carrier that carries an image, the attaching body being detachably attached inside the apparatus housing through an opening of the opening and closing door in a direction crossing an axial direction of the image carrier, an image writer that is opposed to the image carrier to write an image onto the image carrier, and a guide mechanism that moves the image writer in conjunction with opening and closing of the opening and closing door, the guide mechanism guiding the image writer to a write position upon closing of the opening and closing door and guiding the image writer to a retracted position upon opening of the opening and closing door, the retracted position being a position in which the image writer is retracted from a space for attaching and detaching the attaching body. The guide mechanism has a first guide mechanism that has a first guide portion provided in the attaching body, the first guide mechanism guiding the image writer along the first guide portion while the opening and closing door moves from the close position to an intermediate position, the intermediate position being located between the close position and the open position, and a second guide mechanism that has a second guide portion provided in the apparatus housing, the second guide mechanism guiding the image writer along the second guide portion while the opening and closing door moves from the intermediate position to the open position.

DETAILED DESCRIPTION

General Overview of Exemplary Embodiments

FIG. 1illustrates a general overview of an image forming apparatus according to exemplary embodiments of the invention.

InFIG. 1, the image forming apparatus includes an apparatus housing1, a process cartridge3, an image writer5, and a guide mechanism10. The apparatus housing1has an opening and closing door2that opens and closes between a close position and an open position. The process cartridge3, which includes an image carrier4that carries an image, is an attaching body that is detachably attached inside the apparatus housing1through the opening of the opening and closing door2in a direction crossing the axial direction of the image carrier4. The image writer5is opposed to the image carrier4to write an image onto the image carrier4. The guide mechanism10, which moves the image writer5in conjunction with opening and closing of the opening and closing door2, guides the image writer5to a write position ST upon closing of the opening and closing door2, and guides the image writer5to a retracted position RT, which is retracted from the space for attaching and detaching the process cartridge3, upon opening of the opening and closing door2. The guide mechanism10has a first guide mechanism11and a second guide mechanism12. As illustrated inFIG. 2, the first guide mechanism11guides the image writer5along a first guide portion provided in the process cartridge3while the opening and closing door2moves from a close position P1to an intermediate position P2located between the closed position P1and an open position P3, and the second guide mechanism12guides the image writer5along a second guide portion provided in the apparatus housing1while the opening and closing door2moves from the intermediate position P2to the open position P3.

InFIG. 1, the process cartridge3adopts, for example, an electrophotographic system. The process cartridge3is implemented as an assembly integrally incorporating, in addition to the image carrier4, a charging unit6that electrically charges the image carrier4, a developing unit7that develops, with a developer, an electrostatic latent image that is an image written by the image writer5onto the image carrier4, and a cleaning unit8that cleans residues on the image carrier4. A developed image formed on the image carrier4of the process cartridge3is transferred to a recording medium9by a transfer unit (not illustrated).

In the present example, the opening and closing door2may be provided in a side peripheral portion or top portion of the apparatus housing1. The term side peripheral portion as used herein refers to a wall portion surrounding the side periphery of the apparatus housing1. In many cases, the opening and closing door2is disposed on the near side of the apparatus housing1as seen from the user. However, because the apparatus housing1may be installed in any direction, the exemplary embodiments include a wide variety of configurations in which the opening and closing door2is arranged in any given location on the side peripheral portion of the apparatus housing1.

By taking into consideration those cases where the process cartridge3and the image writer5interfere with each other at the time of attaching or detaching the process cartridge3, in the exemplary embodiments, the process cartridge3is attached or detached in a direction crossing the axial direction of the image carrier4.

Further, the image writer5may be any image writer that is opposed to the image carrier4to write an image onto the image carrier4. As the image writer5, an LED print head (to be abbreviated as LPH hereinafter), an ion write head, or the like may be selected as appropriate.

Furthermore, the guide mechanism10is required to guide the image writer5between the write position ST and the retracted position RT in conjunction with opening and closing of the opening and closing door2. In this regard, in order to avoid interference of the process cartridge3with the image writer5at the time of attaching or detaching the process cartridge3, it is required to set the retracted position RT as a location in which the image writer5is retracted from the space necessary for attaching and detaching the process cartridge3.

The first guide mechanism11may be any guide mechanism that guides the image writer5along the first guide portion provided in the process cartridge3. The guide path in the first guide portion may be selected as appropriate. In this regard, when the image writer5reaches the image carrier4side after being guided along the first guide portion, the image writer5is positioned in a predetermined write position ST with respect to the image carrier4positioned in the process cartridge3. Further, upon opening the opening and closing door2from the close position P1to the intermediate position P2, as illustrated inFIG. 2, the image writer5is guided to an intermediate retracted position RT1retracted from the write position ST. At this time, in the intermediate retracted position RT1, the image writer5is located in the vicinity of the entrance to the first guide portion of the process cartridge3.

The second guide mechanism12may be any guide mechanism that guides the image writer5along a second guide portion provided in the apparatus housing1. The guide path in the second guide portion may be set as appropriate. In this regard, when the opening and closing door2reaches the open position P3, as illustrated inFIG. 2, the image writer5reaches the retracted position RT retracted from the space for attaching and detaching the process cartridge3.

Next, various exemplary embodiments of the image forming apparatus will be described below.

First, in one exemplary embodiment, in the guide mechanism10, the first guide mechanism11has a first guide portion having a linear shape, and the second guide mechanism12has a second guide portion that changes the image writer5to an orientation different from that in the first guide portion. In the present example, the image writer5that has changed to a predetermined orientation after being guided through the second guide portion of the second guide mechanism12is passed to the first guide mechanism11. Then, the image writer5gradually changes its orientation while moving along the first guide portion of the first guide mechanism11which has a linear shape until, finally, the image writer5is positioned in the write position ST where the image writer5is held in its normal orientation.

In one exemplary embodiment, a holding mechanism for the image writer5has a holding member that holds the image writer5in a manner that allows the image writer5to advance and retract, and an urging member that urges the image writer5in a direction in which the image writer5advances. The holding member has a guided portion that engages with each of the guide portions of the first and second guide mechanisms11and12. In the present example, in addition to holding the image writer5in a manner that allows its movement between the write position ST and the retracted position RT, the holding mechanism for the image writer5is required to adjust the position of the image writer5at the time of positioning the image writer5in the write position ST of the process cartridge3. Such a position adjusting mechanism may be implemented by, for example, holding the image writer5in a manner that allows its advancing and retracting movement, and also urging the image writer5by the urging member in the direction in which the image writer5advances.

In one exemplary embodiment, in the holding mechanism for the image writer5, the holding member has a pivot point located on the side of the holding member away from the position where the image writer5is held, and the holding member swings about this pivot point to change the orientation of the image writer5.

In the case of a configuration in which this type of holding mechanism is adopted, in one exemplary embodiment, the first guide mechanism11has a guide groove and a protrusion. The guide groove has a linear shape, and is provided in the process cartridge3as the first guide portion. The protrusion is provided as the guided portion in a part of the holding member located away from the pivot point, and protrudes so as to slidably fit in the guide groove. Further, in one exemplary embodiment, the second guide mechanism12has a guide surface and an overhanging member. The guide surface is provided in the apparatus housing1as the second guide portion. The overhanging member is provided as the guided portion in a part of the holding member located away from the pivot point, and overhangs so as to run onto the guide surface to change the image writer5to an orientation directed toward the first guide mechanism11.

In one exemplary embodiment, the process cartridge3has a driven component including the image carrier4, a drive transmission system15that transmits a driving force to the driven component has a coupling component13that couples to the driven component, and the image forming apparatus includes a coupling-component guide mechanism14. The coupling-component guide mechanism14, which moves the coupling component13in conjunction with opening and closing of the opening and closing door2, guides the coupling component13to a coupling position CS upon closing of the opening and closing door2, and guides the coupling component13to a retracted position RT, which is retracted from the space for attaching and detaching the process cartridge3, upon opening of the opening and closing door2. When the opening and closing door2is opened from the close position P1to the open position P3, the coupling-component guide mechanism14moves the coupling component13to the retracted position RT after guiding of the image writer5by the second guide mechanism12is started.

In other words, the coupling-component guide mechanism14of this type may, at the time of opening the opening and closing door2from the close position P1to the open position P3, move the coupling component13to the retracted position RT after the image writer5leaves the first guide portion provided in the process cartridge3.

In one exemplary embodiment, the process cartridge3has, as a driven component, a developing unit7that develops an image written onto the image carrier4by the image writer5into a visible image. The coupling-component guide mechanism14guides the coupling component13capable of coupling to the image carrier4and a developing member7gof the developing unit7which are driven components, to the coupling position CS and the retracted position RT.

Further, in one exemplary embodiment, the coupling-component guide mechanism14operates in conjunction with opening and closing of the opening and closing door2via the guide mechanism10for the image writer. In the present example, the coupling-component guide mechanism14operates in conjunction with opening and closing of the opening and closing door2via the guide mechanism10.

In the case of a configuration in which the amount of guide by the coupling-component guide mechanism14is smaller than the amount of guide by the guide mechanism10for the image writer, the coupling-component guide mechanism14may have a portion that engages with a movable member of the guide mechanism10via an elongated hole to absorb the difference in the amount of guide.

In one exemplary embodiment, the image forming apparatus includes a restricting component16and a restricting-component guide mechanism17. The restricting component16restricts dislodging of the image carrier4in the axial direction. The restricting-component guide mechanism17, which moves the restricting component16in conjunction with opening and closing of the opening and closing door2, guides the restricting component16to a restricting position KS upon closing of the opening and closing door2, and guides the restricting component16to a retracted position RT, which is retracted from the space for attaching and detaching the process cartridge3, upon opening of the opening and closing door2. When the opening and closing door2is opened from the close position P1to the open position P3, the restricting-component guide mechanism17moves the restricting component16to the retracted position RT after guiding of the image writer5by the second guide mechanism12is started.

Further, in one exemplary embodiment, the restricting-component guide mechanism17operates in conjunction with opening and closing of the opening and closing door2via the guide mechanism10for the image writer. In the present example, the restricting-component guide mechanism17operates in conjunction with opening and closing of the opening and closing door2via the guide mechanism10.

Hereinafter, the exemplary embodiments of the invention will be described in more detail with reference to the attached figures.

FIG. 3illustrates a general configuration of an image forming apparatus according to Exemplary Embodiment 1.

InFIG. 3, an image forming apparatus20includes an image forming portion22disposed inside an apparatus housing21, a recording medium supply device24disposed below the image forming portion22, and a discharged recording medium receiver26provided in an upper part of the apparatus housing21. The image forming portion22forms a single-color (for example, black) image. The recording medium supply device24receives a recording medium in a manner that allows supply of the recording medium. A recording medium on which an image has already been formed is discharged to and received in the discharged recording medium receiver26. A recording medium supplied from the recording medium supply device24is discharged to the discharged recording medium receiver26via a transport path25extending in a substantially vertical direction.

In Exemplary Embodiment 1, as illustrated inFIG. 3, the image forming portion22forms an image by the electrophotographic system. The image forming portion22includes a photoconductor31having, for example, a drum-like shape, a charging unit32that electrically charges the photoconductor31in advance, an image writer33that writes an electrostatic latent image onto the photoconductor31charged by the charging unit32, a developing unit34that develops the electrostatic latent image formed on the photoconductor31with toner of various colors, and a cleaning unit35that cleans toner remaining on the photoconductor31.

The image writer33is implemented as a print head (abbreviated as LPH) in which LEDs as a light source are arranged at predetermined pixel pitches. The image writer33is disposed in a predetermined write position ST (seeFIG. 15) opposed to the photoconductor31.

In Exemplary Embodiment 1, a recording medium supplied from a feeder61of the recording medium supply device24is transported by a suitable number of transport rollers (not illustrated) provided in the transport path25. After undergoing registration by a registration roller62, the recording medium passes through a transfer part of a transfer unit63. After an unfixed toner image is fixed onto the recording medium by a fixing unit66by, for example, application of heat and pressure, the resulting recording medium is discharged to the discharged recording medium receiver26.

Process Cartridge

In Exemplary Embodiment 1, as illustrated inFIG. 3, the photoconductor31is implemented in a process cartridge70that is an attaching body integrated with the charging unit32, the developing unit34, and the cleaning unit35. The process cartridge70is detachably attached to a cartridge receiving portion inside the apparatus housing21, forming a major portion of the image forming portion22.

In the present example, the process cartridge70includes a photoconductor assembly71, a developing assembly72, and a toner replenishment container73. The photoconductor assembly71incorporates the photoconductor31, the charging unit32, and the cleaning unit35. The developing assembly72is swingably coupled to the photoconductor assembly71, and incorporates the developing unit34. The toner replenishment container73replenishes the developing unit34with toner.

In the present example, as illustrated inFIG. 3, an opening and closing door27is provided on the front side (corresponding to the left side inFIG. 3) of the apparatus housing21. The opening and closing door27opens and closes with the lower edge of its opening as a support shaft27a. The process cartridge70is detachably attached inside the apparatus housing21by opening the opening and closing door27.

The photoconductor assembly71has a receiving container in which the photoconductor31, the charging unit32, and the cleaning unit35are received. Opposite end portions of the rotating shaft of the photoconductor31are rotatably supported on the opposite ends of the receiving container. Upon attaching the process cartridge70, one end of the rotating shaft of the photoconductor31is drivingly coupled to a drive transmission system via a coupling (coupling component) (not illustrated).

The charging unit32has a charging container portion provided in a part of the receiving container. A charging roller and a cleaning roller are provided inside the charging container portion. The charging roller is in contact with or close proximity to the surface of the photoconductor31. The cleaning roller cleans the charging roller.

Further, the cleaning unit35has a cleaning container portion provided in a part of the receiving container. The opening edge of this cleaning container portion is provided with a plate-like cleaning member that scrapes off toner remaining on the surface of the photoconductor31.

As illustrated inFIG. 3, a developing assembly72has a developing container that is open toward the photoconductor31and receives a two-component developer including toner and carrier. A developing roller91, which carries and transports the developer, is disposed in a location facing the opening of the developing container. A pair of developer agitating members92(which have, for example, spiral vanes attached around the rotating shaft) is disposed on the back side of the developing roller91inside the developing container. Further, a layer-thickness regulating member (for example, a layer-thickness regulating roller) is provided upstream in the rotational direction of the developing part of the developing roller91. The layer-thickness regulating member regulates the layer thickness of developer carried on the developing roller91.

In the present example, upon attaching the process cartridge70, one end of the rotating shaft of the developing roller91is drivingly coupled to the drive transmission system via a coupling (coupling component) (not illustrated).

Guide Mechanism for Image Writer

In Exemplary Embodiment 1, as illustrated inFIG. 3, the image writer (LPH in the present example)33is held by a holding mechanism100. The image writer33is guided along a predetermined guide path by a guide mechanism110via the holding mechanism100.

As illustrated inFIGS. 3 to 8andFIG. 14, the holding mechanism100for the image writer33has a holder101formed by a substantially rectangular plate member that extends in the direction of movement of the image writer33. An end portion on the image writer33side of the holder101is provided with an embracing portion102. The embracing portion102embraces the image writer33in a manner that allows advancing and retracting movement while positioning the opposite longitudinal ends of the image writer33in place. In addition, a suitable number of urging springs103are provided on the image writer33side of the holder101, thereby urging the image writer33embraced by the embracing portion102away from the holder101.

In the present example, a pivot point is provided in the proximal end portion of the holder101located opposite to the embracing portion102. The holder101is supported so as to be swingable about the pivot point.

A flange-like piece105is provided in a part of the holder101which is located on either side of the width direction excluding the embracing portion102. The flange-like piece105projects laterally in a flange-like fashion.

In the present example, the opening and closing door27opens and closes with the support shaft27alocated at the lower edge of its opening as the center of rotation. An interlock mechanism120is provided between the opening and closing door27and the holding mechanism100for the image writer33.

The interlock mechanism120has a pair of first interlock arms121that is rod-shaped and operates in conjunction with opening and closing of the opening and closing door27. Hook pins122and123are provided integrally at positions near one end and the other end, respectively, of the first interlock arm121. A pair of support pieces124projects from the inner surface of the opening and closing door27. The support piece124is provided with a support hole125having a circular shape. The hook pin122provided at one end of the first interlock arm121is rotatably supported in the support hole125.

Further, the interlock mechanism120has a pair of second interlock arms126provided to the apparatus housing21. The second interlock arm126, which is located at a position corresponding to the other end of the pair of first interlock arms121, is formed by a plate member that extends in a substantially horizontal direction. A support groove127, which extends in the longitudinal direction of the second interlock arm126, is formed on the opening and closing door27side of the second interlock arm126. The hook pin123provided near the other end of the first interlock arm121is slidably fitted in the support groove127of the second interlock arm126.

A support shaft128is passed between end portions located on the side of the second interlock arms126away from the opening and closing door27. The proximal end portion located on the side of the holder101away the image writer33is rotatably supported on the support shaft128. Accordingly, the holder101holds the image writer33in a manner that allows the image writer33to swing about the support shaft128as a pivot point.

<Overview of Guide Mechanism>

At the time of opening the opening and closing door27to attach or detach the process cartridge70, the guide mechanism110in the present example guides the image writer33in such a way that the image writer33located in the write position ST retracts to the retracted position RT located outside the space necessary for attaching or detaching the process cartridge70, thereby preventing the process cartridge70and the image writer33from interfering with each other at the time of attaching or detaching the process cartridge70.

Further, the guide mechanism110is required to guide the image writer33located in the retracted position RT to the write position ST, upon closing the opening and closing door27from the open position to the close position after the process cartridge70is attached inside the apparatus housing21.

An example of the guide mechanism110will be described below in detail.

In the present example, the guide mechanism110includes a first guide mechanism111that guides the image writer33with respect to the process cartridge70attached inside the apparatus housing21, and a second guide mechanism112that guides the image writer33with respect to the apparatus housing21.

First, before describing the first guide mechanism111, the second guide mechanism112will be described.

As illustrated inFIGS. 3 to 8, the second guide mechanism112is configured as follows. A pair of guide rails131extending in a substantially horizontal direction is installed in a stationary manner outside the width direction of the pair of second interlock arms126and the holder101of the image writer33. The mutually opposing parts of the pair of guide rails131are provided with a recess132in which the second interlock arm126is able to move in a substantially horizontal direction. The vertical wall portion of the recess132is provided with a guide groove133that extends in a substantially horizontal direction. A guide pin134that is coaxial with, for example, the support shaft128projects outward from the end portion located on the side of the second interlock arm126away from the opening and closing door27. The guide pin134is fitted in the guide groove133of the guide rail131in a manner that allows the guide pin134to slide along the guide groove133.

In the present example, the guide pin134is slidably fitted in the guide groove133of the pair of guide rails131. However, this is not to be construed restrictively. For example, in an alternative configuration, a pinion (not illustrated) is rotatably attached to the guide pin134, and a rack having meshing teeth formed at predetermined pitches is disposed along the guide groove133. By bringing the pinion into meshing engagement with the rack, the pair of guide pins134is moved by a predetermined amount, thereby regulating the amount of movement on either side of the width direction of the holder101.

Further, in the present example, the flange-like piece105of the holder101is arranged inside the recess132of the guide rail131so as to be movable in a non-contact state. A guide base135is provided in a part of the recess132of the guide rail131which is located on the image writer33side. The top portion of the guide base135is provided with a guide surface136that extends in a substantially horizontal direction. A rib137is provided on the lower surface of either side portion of the width direction of the holder101. The rib137is an overhanging member that extends along the longitudinal direction of the flange-like piece105and overhangs downward. The rib137has a first inclined portion138aand a second inclined portion138bthat form a chevron shape with respect to the longitudinal direction of the flange-like piece105.

In the present example, the rib137of the holder101is arranged so as to be movable in a non-contact state in a part of the recess132of the guide rail131excluding the guide base135. When the rib137of the holder101moves toward the guide base135and reaches the guide base135, the first inclined portion138aof the rib137of the holder101comes into contact with the guide surface136. At this time, the holder101changes its orientation about the pivot point along the first inclined portion138aof the rib137, thereby changing the orientation and position of the image writer33.

In the present example, as illustrated inFIGS. 4 to 9, the process cartridge70has an attaching object receiving portion140to which the image writer33may be attached. The first guide mechanism111has a guide groove141and a guided pin142. The guide groove141, which is formed on either side in the width direction of the attaching object receiving portion140of the process cartridge70, extends linearly toward the write position ST of the image writer33. The guided pin142is provided on either side in the width direction of the embracing portion102of the holder101of the image writer33so as to project outward. By slidably fitting the guided pin142in the guide groove141of the process cartridge70, the image writer33is guided with respect to the attaching object receiving portion140of the process cartridge70.

In the present example, guiding by the second guide mechanism112is not performed while guiding by the first guide mechanism111is performed. Specifically, while guiding is performed by the first guide mechanism111, in the second guide mechanism112, the second inclined portion138bof the rib137of the holder101is arranged in a location opposed to the guide surface136so that the second inclined portion138band the guide surface136are not in contact with each other.

The image writer33is guided to the write position ST after being guided by the first guide mechanism111. At this time, in the present example, the image writer33is positioned in a state in which the image writer33is in contact with a positioning portion (not illustrated) previously provided in the attaching object receiving portion140and is urged by the urging spring103.

Guide Mechanism for Coupling Component and Restricting Component

<Coupling Component and Restricting Component>

In Exemplary Embodiment 1, as illustrated inFIGS. 8 to 14, a drive transmission system150is provided on one side of the longitudinal direction of the process cartridge70of the apparatus housing21. The drive transmission system150drives components such as the photoconductor31and the developing roller91of the developing unit34.

In the illustrated example, the drive transmission system150includes a drive transmission system for photoconductor151that transmits a driving force to the photoconductor31, and a drive transmission system for developing unit152that transmits a driving force to the developing roller91of the developing unit34. The drive transmission system for photoconductor151and the drive transmission system for developing unit152are configured to transmit the driving force from a drive motor153(seeFIG. 12) via a drive transmission gear train155and a drive transmission gear train156, respectively.

The drive transmission system for photoconductor151is coupled to the support shaft of the photoconductor31via a coupling component (a coupling in the present example)161, thereby transmitting a drive force to the photoconductor31.

The drive transmission system for developing unit152is coupled to the support shaft of the developing roller91of the developing unit34via a coupling component (a coupling in the present example)162, thereby transmitting a drive force to the developing roller91. In the present example, drive is transmitted to the developer agitating member92of the developing unit34in response to the transmission of a drive force to the developing roller91.

A pair of restricting components (restricting plates in the present example)170is provided on either axial side of the photoconductor31of the process cartridge70, thereby restricting dislodging of the photoconductor31in the axial direction.

In Exemplary Embodiment 1, at the time of attaching or detaching the process cartridge70, the coupling component161or162is required to retract to a retracted position RT located outside a coupling position CS with the shaft portion of the photoconductor31or the developing roller91. Further, the restricting component170is required to retract to a retracted position RT located outside a restricting position KS that restricts dislodging of the photoconductor31in the axial direction.

The retracted position RT of the coupling component161or162may be set to any such position in which the shaft portion of the photoconductor31or the developing roller91does not interfere with the coupling component161or162at the time of attaching or detaching the process cartridge70. Accordingly, the retracted position RT of the coupling component161or162may not necessarily be set outside the space for attaching and detaching the process cartridge70. Likewise, the retracted position RT of the restricting component170may be set to any such position in which the axial end portion of the photoconductor31does not interfere with the restricting component170at the time of attaching or detaching the process cartridge70.

Accordingly, the retracted position RT of the restricting component170may not necessarily be set outside the space for attaching and detaching the process cartridge70.

Therefore, the span between the coupling position CS and the retracted position RT of the coupling component161or162, and the span between the restricting position KS and the retracted position RT of the restricting component170may be both set smaller than the span between the write position ST and the retracted position RT of the image writer33.

<Overview of Guide Mechanism for Coupling Component and Restricting Component>

In Exemplary Embodiment 1, the coupling component161or162, and the restricting component170are each guided along a predetermined guide path via a guide mechanism180that operates in conjunction with opening and closing of the opening and closing door27.

As illustrated inFIGS. 10 to 14, the guide mechanism180in the present example, which is provided on either axial side of the photoconductor31of the process cartridge70, is configured differently on either side.

That is, as illustrated inFIG. 13, the drive transmission system150is provided on one side of the axial direction of the photoconductor31of the process cartridge70but not on the other side. Accordingly, a drive-side guide mechanism180A including the drive transmission system150has the function of guiding the coupling component161or162and the restricting component170, whereas a non-drive-side guide mechanism180B that does not include the drive transmission system150is only required to have the function of guiding the restricting component170.

An example of the guide mechanism180will be described below in detail.

First, the drive-side guide mechanism180A will be described.

In the present example, as illustrated inFIG. 13, the drive-side guide mechanism180A has a link arm181that extends in a substantially horizontal direction. The link arm181is located outside the second interlock arm126of the interlock mechanism120(seeFIG. 4). The link arm181, which is set longer than the second interlock arm126, extends to the vicinity of the photoconductor31of the process cartridge70. The link arm181has an overhanging portion182, in which the part of the link arm181corresponding to the vicinity of the photoconductor31of the process cartridge70overhangs further outward in a stepped configuration in comparison to the other part.

Further, in the present example, the guide pin134of the second interlock arm126penetrates the guide groove133of the guide rail131, and further slidably fits in the first guide groove183of the link arm181. In the present example, the guide pin134of the second interlock arm126is used for both the guide groove133and the first guide groove183. However, it is of course possible not to use the guide pin134also as a guide pin that fits in the first guide groove183of the link arm181but provide another guide pin as such a guide pin.

A positioning pin (not illustrated), which is provided to the frame of the apparatus housing21or a bracket secured to this frame, slidably fits in the second guide groove184of the link arm181, thus keeping the advancing and retracting direction of the link arm181substantially horizontal.

Further, in Exemplary Embodiment 1, the coupling component161or162is held by a first link holder187having a U-shaped stepped holding portion. A hook pin188(seeFIG. 21A) is provided in a part of the first link holder187. The hook pin188slidably fits in the third guide groove185.

In substantially the same manner as the coupling component161or162, the restricting component170is held by a second link holder190. A hook pin191(seeFIG. 21A) is provided in a part of the second link holder190. The hook pin191slidably fits in a part of the third guide groove185different from where the hook pin188is located.

Next, the non-drive-side guide mechanism180B will be described.

In the present example, as illustrated inFIG. 13, the non-drive-side guide mechanism180E has a link arm201that extends in a substantially horizontal direction. The link arm201is located outside the second interlock arm126of the interlock mechanism120(seeFIG. 4). The link arm201is set longer than the second interlock arm126and extends to the vicinity of the photoconductor31of the process cartridge70. The link arm201has a shape different from the link arm181.

In the present example, the link arm201has an arm body202in a part of the link arm201corresponding to the second interlock arm126. A projection203is provided at the inner upper edge of the arm body202. Further, the link arm201has an overhanging portion204located in a part of the link arm201from the arm body202to a position corresponding to the vicinity of the photoconductor31of the process cartridge70. The overhanging portion204overhangs further outward with respect to the projection203in a stepped configuration.

In substantially the same manner as the link arm181, the first guide groove183is formed in the projection203of the link arm201, and the second guide groove184and the third guide groove185are formed in the overhanging portion204. In this regard, the third guide groove185of the link arm201is used to adjust the path of advancing and retracting movement of the restricting component170. Because the path of advancing and retracting movement of each of the coupling component161or162and the restricting component170is to be taken into consideration for the third guide groove185of the link arm181, the length of the third guide groove185in the link arm201is set shorter than that in the link arm181.

Further, the guide pin134of the second interlock arm126, a positioning pin186securely provided to the frame or bracket of the apparatus housing21, and the hook pin191of the second link holder190that holds the restricting component (restricting plate in the present example)170slidably fit in the first guide groove183, the second guide groove184, and the third guide groove185, respectively, of the link arm201.

<Dimension Settings of Guide Mechanism for Coupling Component and Restricting Component>

In the present example, s, s1, and s2are set as follows in the link arm181and the link arm201, where s1represents the length of the first guide groove183, s2represents the length of the second guide groove184, and s represents the amount of movement along a substantially horizontal direction of the second interlock arm126.
s1>s2  (1)
s≈=s1+s2  (2)
With the above dimensional relationship, when the opening and closing door27is located in the close position P1(seeFIG. 15), for example, as illustrated inFIGS. 21A and 21B, the guide pin134of the second interlock arm126is at the end edge of the first guide groove183of each of the link arms181and201which is located away from the opening and closing door27.

At this time, the positioning pin (not illustrated) is arranged at the end edge of the second guide groove184which is located near the opening and closing door27.

Further, as illustrated inFIGS. 16, 17, and 21A and 21B, upon gradually opening the opening and closing door27from the close position P1toward the intermediate open positions P21and P22, the guide pin134of the second interlock arm126of the interlock mechanism120moves by the distance s1, and reaches the end edge on the opening and closing door27side of the first guide groove183of each of the link arms181and201. In the meantime, in the first guide groove183of each of the link arms181and201, the guide pin134of the second interlock arm126of the interlock mechanism120slides along the first guide groove183, and hence the operational force associated with opening and closing of the opening and closing door27is not transmitted to the link arms181and201. Therefore, in the second guide groove184of each of the link arms181and201, the position of the positioning pin186is the same as that when the opening and closing door27is located in the close position P1.

Thereafter, upon opening the opening and closing door27to the open position P3as illustrated inFIG. 18andFIGS. 21A and 21B, the link arms181and201move by the distance s2. In the meantime, the positioning pin186moves relatively by the distance s2in the second guide groove184, and thus the link arms181and201move while keeping their substantially horizontal orientation.

When the link arms181and201move in this state, the hook pin191of each of the first and second link holders187and190moves obliquely downward along the slope of the third guide groove185. As a result, the first and second link holders187and190retract from the coupling position CS and the restricting position KS, respectively, causing the coupling component161or162and the restricting component170to move to the retracted position RT.

Operation of Image Forming Apparatus

First, operation of the image forming apparatus according to Exemplary Embodiment 1 will be described.

Now, when the image forming apparatus20is in a state capable of image formation, as illustrated inFIG. 3, the process cartridge70of the image forming portion22is attached to the cartridge receiving portion (not illustrated) inside the apparatus housing21.

Upon closing the opening and closing door27with the process cartridge70being attached to the cartridge receiving portion, the image writer33is positioned in a positioning portion previously provided in the process cartridge70, and the image writer33is set to a predetermined write position ST in relation to the photoconductor31.

Further, the coupling component161or162is set in the coupling position CS, and the restricting component170is set in the restricting position KS. The driving force from the drive transmission system150is transmitted to components such as the photoconductor31and the developing unit34of the process cartridge70.

In this state, after a single-color (for example, black) electrostatic latent image is written onto the photoconductor31of the image forming portion22by the image writer33, a single-color toner image is formed by the developing unit34, and the toner image is transferred to a recording medium via the transfer unit62. Thereafter, the resulting recording medium is discharged to the discharged recording medium receiver26via the fixing unit66.

Replacement of Process Cartridge

Next, a process of replacing the process cartridge70incorporated into the image forming apparatus will be described.

The process cartridge70may be replaced as follows. First, the opening and closing door27of the apparatus housing21is opened. Then, the process cartridge70that is currently attached is removed from the opening of the opening and closing door27.

At this time, in Exemplary Embodiment 1, by opening the opening and closing door27from the close position P1to the open position P3, the image writer33is guided by the guide mechanism110(the first guide mechanism111and the second guide mechanism112) from the write position ST to the retracted position RT.

Further, in the present example, the coupling component161or162and the restricting component170are guided by the guide mechanism180to the retracted position RT from the coupling position CS and the restricting position KS, respectively.

In this state, the image writer33retracts to the retracted position RT located outside the space for attaching and detaching the process cartridge70, and the coupling component161or162and the restricting component170are guided to the retracted position RT retracted from the coupling position CS and the restricting position KS, respectively. Thus, the coupling due to the coupling component161or162is released, and the restriction of dislodging of the photoconductor31by the restricting component170is released.

Therefore, at the time of attaching or detaching the process cartridge70, the image writer33, the coupling component161or162, and the restricting component170do not interfere with the process cartridge70.

<Guiding of Image Writer>

Now, how the guide mechanism110guides the image writer33will be described.

When the opening and closing door27is located in the close position P1as illustrated inFIG. 15, the process cartridge70is attached to the cartridge receiving portion (not illustrated) inside the apparatus housing21. At this time, the image writer33is positioned in a positioning portion210(seeFIG. 20) previously provided in the process cartridge70, and is arranged in a predetermined write position ST with respect to the photoconductor31.

If the opening and closing door27is started to open in this state and moved to the intermediate open position P21as illustrated inFIG. 16, the opening action of the opening and closing door27is transmitted to the guide mechanism110via the interlock mechanism120.

At this time, in the interlock mechanism120, the first interlock arm121is drawn out as the opening and closing door27is opened. Accordingly, the second interlock arm126is drawn out toward the opening and closing door27. At this stage, since the holder101of the image writer33is coupled to the second interlock arm126via the support shaft128, as the second interlock arm126is drawn out, the holder101is drawn out while being able to swing about the support shaft128as a pivot point. Accordingly, as the holder101is drawn out, the image writer33moves away from the write position ST.

In the second guide mechanism112, as the holder101is drawn out, the guide pin134, which is provided coaxially with the support shaft128of the holder101, moves along the guide groove133of the guide rail131.

In this state, in the first guide mechanism111, the guided pin142provided in the embracing portion102of the image writer33moves linearly along the guide groove141of the process cartridge70as the holder101is drawn out. Therefore, the holder101and the image writer33move away from the write position ST while changing to such an orientation that linearly connects the guide pin134and the guided pin142. In the meantime, in the second guide mechanism112, the second inclined portion138bof the rib137of the holder101is arranged in a location corresponding to the guide surface136of the guide base135. At this time, the second inclined portion138bof the rib137maintains a non-contact state with respect to the guide surface136of the guide base135.

Thereafter, if the opening and closing door27is further opened to move to the intermediate open position P22as illustrated inFIG. 17, the second interlock arm126is further drawn out toward the opening and closing door27via the interlock mechanism120. As a result, the holder101is drawn out, causing the image writer33to reach the intermediate retracted position RT1located outside the attaching object receiving portion140of the process cartridge70.

In this state, the guided pin142, which is provided in the embracing portion102of the holder101, moves out of the guide path running along the guide groove141of the process cartridge70. Consequently, the first inclined portion138aof the rib137formed on the lower surface of the holder101of the image writer33comes into contact with the guide surface136of the guide base135. Therefore, with the guide pin134as a pivot point, the holder101is arranged on the guide surface136of the guide base135via the rib137. As a result, in the intermediate retracted position RT1, the image writer33is held at a predetermined position without falling downward.

Thereafter, when the opening and closing door27is further opened to move to the final open position P3as illustrated inFIG. 18, the second interlock arm126of the interlock mechanism120is further drawn out toward the opening and closing door27, and the guide pin134of the second interlock arm126slides along the guide groove133of the guide rail131. Accordingly, the holder101is further drawn out, and the first inclined portion138aof the rib137of the holder101moves while in contact with the guide surface136. As a result, in response to changes in the contact position between the first inclined portion138aof the rib137and the guide surface136, the image writer33held by the holder101gradually changes to a substantially horizontal orientation. In this way, the image writer33retracts to the retracted position RT located farther away from the process cartridge70than the intermediate retracted position RT1.

Since the retracted position RT is located outside the space for attaching and detaching the process cartridge70, the process cartridge70and the image writer33retracted to the retracted position RT do not interfere with each other at the time of attaching or detaching the process cartridge70.

Next, a case will be described in which, at the time of replacing the process cartridge70, the opening and closing door27is closed from the open position P3to the close position P1after the process cartridge70is attached to the cartridge receiving portion inside the apparatus housing21.

Now, as illustrated inFIG. 18, when the opening and closing door27is started to close from the open position P3after the process cartridge70is attached, the guide mechanism110(the first guide mechanism111and the second guide mechanism112) guides the image writer33via the interlock mechanism120along a predetermined guide path.

In the present example, upon starting to close the opening and closing door27, the second interlock arm126of the interlock mechanism120is pushed into the apparatus housing21in conjunction with operation of the first interlock arm121. Accordingly, the image writer33moves toward the photoconductor31via the holder101.

At this time, in the second guide mechanism112, the guide pin134of the second interlock arm126moves linearly along the guide groove133of the guide rail131, and the first inclined portion138aof the rib137, which is formed on the lower surface on either side of the width direction of the holder101of the image writer33, moves while in contact with the guide surface136of the guide base135. Accordingly, with the guide pin134as a pivot point, the holder101is gradually lifted up from the guide surface136by the first inclined portion138aof the rib137.

Therefore, the image writer33moves along a curved guide path m2(seeFIG. 20) while gradually changing from a substantially horizontal orientation to an orientation in which the distal end side of the image writer33is lifted up.

Thereafter, as the opening and closing door27is closed to the intermediate open position Pnas illustrated inFIG. 17, the interlock mechanism120further pushes the second interlock arm126in, and thus the second guide mechanism112further moves the image writer33toward the photoconductor31along the curved guide path m2(seeFIG. 20). As a result, the image writer33reaches the position immediately in front of the attaching object receiving portion140of the process cartridge70.

Thereafter, as the opening and closing door27is further closed to the intermediate open position P21as illustrated inFIG. 16, the interlock mechanism120operates in conjunction with the closing action of the opening and closing door27to further push the second interlock arm126in, and the second interlock arm126pushes the image writer33in to the attaching object receiving portion140of the process cartridge70via the holder101.

At this time, the second guide mechanism112moves the image writer33in a state in which the first inclined portion138aof the rib137of the holder101is in contact with the guide surface136of the guide base135. Then, by gradually changing the tilt orientation of the holder101to change the orientation of the image writer33, the second guide mechanism112guides the image writer33in such a way that the image writer33is inserted into the attaching object receiving portion140of the process cartridge70.

Thereafter, when the image writer33is inserted into the attaching object receiving portion140of the process cartridge70as illustrated inFIGS. 19 and 20, guiding of the image writer33by the first guide mechanism111is started. That is, the guided pin142, which is provided on either side of the embracing portion102of the holder101, moves along the guide groove141having a linear shape inside the attaching object receiving portion140. As a result, the image writer33moves toward the photoconductor31along a linear guide path m1.

At this time, guiding of the image writer33by the second guide mechanism112is removed when guiding by the first guide mechanism111is started. That is, as the image writer33moves toward the photoconductor31, the first inclined portion138aof the rib137formed on the holder101moves past the guide surface136of the guide base135, and the second inclined portion138bof the rib137moves to a position corresponding to the guide surface136of the guide base135. Accordingly, the rib137is arranged in a non-contact state with respect to the guide surface136.

Then, upon closing the opening and closing door27to the close position P1as illustrated inFIG. 15, the interlock mechanism120operates in conjunction with the closing action of the opening and closing door27to further push the second interlock arm126in, causing the image writer33to be pushed in along the attaching object receiving portion140of the process cartridge70via the holder101.

At this time, since the image writer33is urged by the urging spring103in the embracing portion102of the holder101, when the image writer33comes into abutment with the positioning portion210(seeFIG. 17) that is determined in advance, the image writer33stops its movement and is positioned in the positioning portion210. At this stage, the image writer33is set in a predetermined write position ST.

<Guiding of Coupling Component and Restricting Component>

Next, guiding of the coupling component161or162and the restricting component170by the guide mechanism180will be described.

Now, in a state in which the opening and closing door27is in the close position P1as illustrated inFIG. 15, the coupling component161or162is set in the coupling position CS, and the restricting component170is also set in the restricting position KS. Therefore, the driving force from the drive transmission system150is transmitted to the photoconductor31or the developing unit34of the process cartridge70via the coupling component161or162. Since dislodging of the photoconductor31at either axial end is restricted by the restricting component170, the photoconductor31is unlikely to become dislodged in the axial direction during rotation of the photoconductor31.

In this state, as the opening and closing door27is opened toward the open position P3as illustrated inFIGS. 16 and 17, the interlock mechanism120operates in conjunction with the opening action of the opening and closing door27, causing the guide mechanism110for the image writer to operate.

At this time, the guide pin134of the second interlock arm126of the interlock mechanism120moves along the guide groove133of the guide rail131, and also moves along the first guide groove183of each of the link arms181and201of the guide mechanism180for the coupling component and the restricting component.

In this state, the guide pin134slidably fits in the first guide groove183of each of the link arms181and201. While the opening and closing door27is opened from the close position P1to the intermediate open position P22, as illustrated inFIG. 21B, the guide pin134slides by the distance s1along the guide groove133and reaches the end edge on the opening and closing door27side of the guide groove133. At this time, a driving force has not yet been transmitted to the link arms181and201, and thus the coupling component161or162and the restricting component170are still arranged in the coupling position CS and the restricting position KS, respectively.

That is, in the present example, until the guide mechanism110for the image writer retracts the image writer33to the intermediate retracted position RT1, the guide mechanism180for the coupling component and the restricting component does not retract the coupling component161or162and the restricting component170. Therefore, the coupling component161or162and the restricting component170are prevented from moving to the retracted position RT to allow movement of the process cartridge70before the image writer33is retracted to the intermediate retracted position RT1.

Thereafter, upon opening the opening and closing door27to the open position P3as illustrated inFIG. 18, as illustrated inFIGS. 11 to 14andFIGS. 21A and 21B, the guide pin134of the second interlock arm126reaches the end edge on the opening and closing door27side of the first guide groove183in each of the link arms181and201. While the opening and closing door27moves from the intermediate open position P22to the open position P3, the link arms181and201are drawn out toward the opening and closing door27.

As the link arms181and201move toward the opening and closing door27by the distance s2in this state, in the link arms181and201, the hook pin188of the first link holder187, and the hook pin191of the second link holder190move obliquely downward along the third guide groove185. Accordingly, the first link holder187and the second link holder190are guided downward. As a result, the coupling component161or162held by the first link holder187moves to the retracted position RT retracted from the coupling position CS, and the restricting component170held by the second link holder190moves to the retracted position RT retracted from the restricting position KS.

In this state, the coupling component161or162and the restricting component170have retracted to the retracted position RT located outside the coupling position CS and the restricting position KS, respectively. Therefore, the process cartridge70does not interfere with the coupling component161or162and the restricting component170at the time of attaching or detaching the process cartridge70.

When the opening and closing door27is to be closed from the open position P3to the close position P1after the process cartridge70is attached, as illustrated inFIGS. 15 to 18andFIGS. 21A and 21B, the guide mechanism180operates in conjunction with the closing action of the opening and closing door27via the interlock mechanism120and the guide mechanism110for the image writer.

In the present example, the link arms181and201are pushed into the apparatus housing21while the opening and closing door27is closed from the open position P3to the intermediate open position P22. Accordingly, the coupling component161or162and the restricting component170are set in the coupling position CS and the restricting position KS, respectively.

Thereafter, even when the opening and closing door27is closed to the close position P1, the link arms181and201do not move, and the coupling component161or162and the restricting component170remain to be set in the coupling position CS and the restricting position KS, respectively.

Modification

In Exemplary Embodiment 1, each of the image writer33, the coupling component161or162, and the restricting component170may be retracted to the retracted position by the corresponding guide mechanisms that operate in conjunction with the opening and closing door27. However, this is not to be construed restrictively. For example, in an alternative configuration, only the image writer33may be retracted from its write position by a guide mechanism that operates in conjunction with the opening and closing door27.

That is, in Exemplary Embodiment 1, the link arms181and201are adopted for the guide mechanism180for the coupling component and the restricting component. However, for the coupling component161or162or the restricting component170, for example, as illustrated inFIG. 22, it is of course possible to use a combination of a rack231and a pinion232without using the guide mechanism180. That is, the pinion232is driven by a drive source (not illustrated) to enable advancing and retracting movement of the rack231, and this advancing and retracting movement of the rack231is used to advance or retract members233and234, which respectively hold the coupling component161or162and the restricting component170, between the coupling position or restricting position and the retracted position.