JP5311802B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus capable of securing workspace made open at a wide angle without causing relative movement in an axial direction in a contact state with an image carrier due to the attachment/detachment of a transfer roller. <P>SOLUTION: The image forming apparatus 100 is constituted so that space between an intermediate transfer belt 101 and a secondary transfer roller 117 can be expanded from 0 to 90 degrees when a conveyance door 10 is opened to a side surface side. By opening the conveyance door 10 from an apparatus body 100A, a pair of rollers arranged in a recording material conveyance path is divided and also the divided space is largely expanded, so that accessing the space between the pair of rollers is facilitated. The conveyance door 10 is supported by a turning shaft 503 relative to a bearing part 502 which can be drawn out to a side surface direction by a slide mechanism 501. The conveyance door 10 is expanded backward centering the turning shaft 503 after it is drawn out toward the side surface side to a position where the secondary transfer roller 117 is separated from the intermediate transfer belt 101 by the slide mechanism 501. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus that transports a recording material in a vertical direction and supplies the recording material to a transfer unit to transfer a toner image from an image bearing member. It relates to the development structure.

  An image forming apparatus that transports a recording material in a vertical direction and supplies the recording material to a nip (transfer portion) between an upright surface of an image carrier and a transfer roller to transfer a toner image from the image carrier has been put into practical use.

  Also, by supporting the recording material transport roller and transfer roller on the side housing door and opening the housing door, the recording material transport path and transfer section can be unfolded together to allow the jam sheet to be taken out. Such image forming apparatuses have been put into practical use.

  Patent Document 1 discloses an image forming apparatus that conveys a recording material in a vertical direction and feeds the recording material to a nip (secondary transfer portion) between an upright surface of an intermediate transfer belt and a secondary transfer roller. Here, the recording material transport roller and the secondary transfer roller are supported on the side housing door, and the recording material transport path and the transfer section are unfolded integrally by opening the housing door. The sheet can be taken out.

  Patent Document 2 discloses a tandem intermediate transfer type full-color image forming apparatus in which yellow, magenta, cyan, and black image forming units are arranged on a downward surface of an intermediate transfer belt. Here, the secondary transfer portion of the toner image carried on the intermediate transfer belt is disposed on the rising surface of the intermediate transfer belt, and below the secondary transfer portion is a conveyance roller that feeds the recording material to the secondary transfer portion Is arranged.

JP 2004-269151 A Japanese Patent Application No. 2002-180675

  The secondary transfer portion development structure disclosed in Patent Document 1 is such that when the housing door is opened and closed, the intermediate transfer belt and the secondary transfer roller are slightly moved relative to each other in the axial direction in contact with each other, and are rubbed against the intermediate transfer belt. Traces may be formed (see FIG. 15).

  Here, since both ends of the secondary transfer roller are spring-biased and pressed against the intermediate transfer belt, the secondary transfer roller and the intermediate transfer belt are kept in contact with each other for a while after opening the housing door. . For this reason, in the state where the secondary transfer roller and the intermediate transfer belt are in contact with each other, the axial movement of the secondary transfer roller accompanying the rotation of the housing door occurs, and the surface layer component of the secondary transfer roller is rubbed. May adhere to the intermediate transfer belt.

  Therefore, a structure has been proposed in which both ends of the secondary transfer roller are supported by slide guides and pulled out while being parallel to the intermediate transfer belt. Interferes with the work performed between the two. In addition, there is a problem that only a slide guide cannot secure a free work space that is opened at a wide angle toward the operator, as in the case where the housing door is deployed.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus that can secure a work space that is open at a wide angle without causing relative movement in the axial direction in a state in which the transfer roller is attached to or detached from the image carrier. It is said.

The image forming apparatus according to the present invention includes a transfer roller that forms a transfer portion that contacts a toner image bearing member and transfers the toner image , and supports both ends of the transfer roller toward the image bearing member. And a supporting mechanism for biasing. And a moving mechanism for moving the support mechanism so that the transfer roller is spaced apart from the image carrier in parallel, and is at one end side in the rotation axis direction of the transfer roller and orthogonal to the rotation axis of the transfer roller. A rotation mechanism that rotates the support mechanism so that a facing portion between the transfer roller and the image carrier is opened around a rotation shaft provided in a direction, and the support mechanism by the moving mechanism A restricting mechanism for restricting the rotation of the support mechanism by the rotation mechanism until at least the transfer roller is separated from the image carrier along with the movement of the image forming member. The moving mechanism is a parallel separation slide mechanism that translates the support mechanism in a direction orthogonal to the rotation axis of the transfer roller, and the limiting mechanism is at a position away from the rotation axis of the rotation mechanism. It is a guide structure for guiding the support mechanism in the orthogonal direction.

  According to the present invention, after the separation operation between the image carrier and the transfer roller by the moving mechanism is completed, the development of the interval between the transfer roller and the image carrier by the rotation mechanism is started. For this reason, in the state where the image carrier and the transfer roller are in contact with each other, relative movement in the axial direction does not occur between them.

  Therefore, as the transfer roller is attached and detached, the image carrier and the transfer roller are unfolded between the image carrier and the transfer roller and released at a wide angle without moving relative to each other in the axial direction in a state where the image carrier and the transfer roller are in contact with each other. Work space is secured.

  Hereinafter, some embodiments of the present invention will be described in detail with reference to the drawings. As long as the transfer roller is rotated after being pulled out to a position where it does not rub against the image bearing member and the interval between the two is expanded, a part or all of the configuration of each embodiment is replaced with the alternative configuration. Other embodiments replaced with can also be implemented.

  Therefore, not only an image forming apparatus that transfers a toner image carried on an intermediate transfer member to a recording material but also an image forming apparatus that carries a toner image carried on a photosensitive member on a recording material.

  In the present embodiment, only main parts related to toner image formation / transfer will be described. However, the present invention includes a printer, various printing machines, a copier, a fax machine, a composite machine, in addition to necessary equipment, equipment, and a housing structure. It can be implemented in various applications such as a machine.

  In addition, about the general matter of the image forming apparatus shown by patent document 1, 2, illustration is abbreviate | omitted and the overlapping description is abbreviate | omitted.

  In the description, the reference symbols in parentheses attached to the configuration names used in the claims are examples for assisting understanding of the invention, and the configuration is limited to the corresponding members in the embodiments. Is not.

<First Embodiment>
FIG. 1 is a perspective view of the image forming apparatus according to the first embodiment, FIG. 2 is an explanatory diagram of an internal configuration of the image forming apparatus, and FIG. 3 is an explanatory diagram of a configuration of a process cartridge.

  As shown in FIG. 1, in the image forming apparatus 100, a document reading device 100R that scans and reads an image on the surface of a document to generate image data is disposed on the apparatus main body 100A.

  In the image forming apparatus 100, an intermediate transfer belt 101 and a transfer frame 102 that supports the intermediate transfer belt 101 are arranged substantially horizontally at the center of the apparatus main body 100A.

  When the front door 400 is opened to the front side, the image forming apparatus 100 can slide the intermediate transfer unit 115 to the front side and pull it out.

  When the conveyance door 10 is opened to the side surface, the image forming apparatus 100 can expand the distance between the secondary transfer roller 117 supported by the inner door 20 and the intermediate transfer belt 101 from 0 degrees to 90 degrees. By opening the conveyance door 10 from the apparatus main body 100A, the roller pairs arranged in the recording material conveyance path HA are divided, and the divided intervals are greatly expanded, so that it is easy to access the intervals between the roller pairs. It can be done.

  The conveyance door 10 is pivotally supported by a rotation shaft 503 with respect to a bearing portion 502 that can be pulled out in a side surface direction in an upright state by a pair of upper and lower slide mechanisms 501.

  The transport door 10 is pulled out to the side from the intermediate transfer belt 101 to a position where the secondary transfer roller 117 is separated by a pair of upper and lower slide mechanisms 501, and then is developed rearward about the rotation shaft 503.

  The moving mechanism (501) moves the support mechanism (10) so that the transfer roller (117) is separated from the image carrier (101) in parallel.

Turning mechanism (503), as opposed portion of the transfer roller (117) an image bearing member (101) is opened, causes pivoting of the support mechanism (20) to the central pivot axis (503) .

  The limiting mechanism (9: FIG. 7) limits the rotation of the support mechanism (10) until at least the transfer roller (117) is separated from the image carrier (101) with the movement of the support mechanism (10).

  As shown in FIG. 2, the image forming apparatus 100 is a tandem intermediate transfer type full-color printer in which process cartridges 103 </ b> Y, 103 </ b> M, 103 </ b> C, and 103 </ b> K having different development colors are arranged along an intermediate transfer belt 101. A plurality of process cartridges 103Y, 103M, 103C, and 103K including photosensitive drums 1Y, 1M, 1C, and 1K are disposed below the intermediate transfer belt 101, and the photosensitive drums 1Y, 1M, 1C, and 1K are arranged in the middle. It is in contact with the transfer belt 101.

  The process cartridges 103Y, 103M, 103C, and 103K are arranged on a substantially horizontal straight line at regular intervals to form toner images of yellow, magenta, cyan, and black, respectively, and intermediate transfer belts. Primary transfer to 101.

  The intermediate transfer belt 101 is supported across a support roller 106, a counter roller 116, a tension roller 105, and primary transfer rollers 5Y, 5M, 5C, and 5K. The intermediate transfer belt 101 is driven by a counter roller 116 that also serves as a drive input roller, and rotates in the direction of arrow R2.

  The four-color toner images formed on the intermediate transfer belt 101 are taken out from the recording material storage cassette 121 and collectively secondary transferred to the recording material P passing through the secondary transfer portion T2.

  The fixing device 8 is configured by pressing the pressure roller 8b against the heating roller 8a, and heats and presses the recording material P delivered from the secondary transfer portion T2, so that four color toner images are formed on the surface of the recording material P. To fix.

  The recording material P on which the four color toner images have been fixed by the fixing device 8 is discharged and stacked on a discharge tray 125 below the document reading device 100R through a discharge roller 124.

  Since the process cartridges 103Y, 103M, 103C, and 103K are configured in common except for the difference in development color, here, the black process cartridge 103K will be described with reference to FIG. The other process cartridges 103Y, 103M, and 103C are described by replacing K at the end of the symbol in FIG. 3 and the description with Y, M, and C.

  As shown in FIG. 3, a primary charger 2K, an exposure device 3, a developing device 4K, a primary transfer roller 5K, and a cleaning device 6K are arranged around the photosensitive drum 1K.

  The photosensitive drum 1K has an organic optical semiconductor (OPC) photosensitive layer formed on the outer peripheral surface of an aluminum cylinder, is rotatably supported, and rotates in the direction of arrow R1 at a predetermined process speed.

  The primary charger 2K applies a negative DC voltage from the power source D3 to the charging roller to charge the surface of the photosensitive drum 1K to a uniform negative potential.

  The exposure apparatus 3 is arranged in common with respect to the process cartridges 103Y, 103M, 103C, and 103K shown in FIG. The exposure apparatus 3 scans a scanning beam image data obtained by developing image data with a rotating mirror, and writes an electrostatic image on the surface of the charged photosensitive drum 1K.

  The developing device 4K stirs the two-component developer containing the non-magnetic toner and the magnetic carrier to charge the non-magnetic toner to the negative polarity, and holds the charged two-component developer on the developing sleeve 4s in a spiked state. Rub the photosensitive drum 1K. The toner storage unit 111 stores unused toner, and replenishes the developing device 4K with unused toner corresponding to the amount of toner used in the developing device 4K.

  The power source D4 applies a developing voltage obtained by superimposing an AC voltage on a negative DC voltage to the developing sleeve 4s, and is charged to the electrostatic image of the photosensitive drum 1K having a positive polarity relative to the developing sleeve 4s. To reverse develop the electrostatic image.

  The primary transfer roller 5K sandwiches the intermediate transfer belt 101 between the photosensitive drum 1K and forms a primary transfer portion T1 between the photosensitive drum 1K and the intermediate transfer belt 101.

  The power source D1 applies a positive DC voltage to the primary transfer roller 5K, and primarily transfers the toner image carried on the photosensitive drum 1K to the intermediate transfer belt 101.

  The cleaning device 6K rubs the cleaning blade against the photosensitive drum 1K, removes the transfer residual toner that passes through the primary transfer portion T1 and remains on the surface of the photosensitive drum 1K, and collects it in the waste toner container 113.

  The intermediate transfer belt 101 conveys the toner image transferred at the primary transfer portion T1 to the secondary transfer portion T2.

  The secondary transfer roller 117 is in pressure contact with the opposing roller 116 via the intermediate transfer belt 101 to form a secondary transfer portion T2 between the secondary transfer roller 117 and the intermediate transfer belt 101.

  The recording material P loaded in the recording material storage cassette 121 is conveyed to the feeding roller 118, separated one by one from the separation pad 119, and delivered to the registration roller 123.

  The registration roller 123 receives the recording material P in the stopped state, corrects the skew, and feeds the recording material P to the secondary transfer portion T2 in time with the toner image carried on the intermediate transfer belt 101. The secondary transfer unit T2 sandwiches and conveys the recording material P over the toner image on the intermediate transfer belt 101.

  The power source D <b> 2 applies a positive DC voltage to the secondary transfer roller 117 to secondary-transfer the toner image carried on the intermediate transfer belt 101 to the recording material P.

  In the first embodiment, the intermediate transfer belt 101 is disposed in the horizontal direction, and the process cartridges 103Y, 103M, 103C, and 103K are sequentially disposed from the upstream side with respect to the downward surface of the intermediate transfer belt 101. A rising surface of the intermediate transfer belt 101 is formed on the downstream side of the most downstream process cartridge 103K, and the secondary transfer portion T2 is disposed on the rising surface.

  By arranging in this way, it is possible to shorten the time until the toner image primarily transferred from the process cartridges 103Y, 103M, 103C, and 103K is secondarily transferred and the transport distance, thereby shortening the print time.

  In the first embodiment, the secondary transfer portion T2 and the conveyance path HA of the recording material P form a vertical path, and the conveyance path HA with respect to the apparatus main body 100A is easy to remove the jammed sheet on the conveyance path HA. A transfer door 10 is provided that can be opened and closed.

The support mechanism (20) is installed on the housing door (10) that is opened and closed by the rotation mechanism (503), and is on the transfer roller side (117 side) in the transport roller pair (123) disposed in the transport path (HA). ) Is supported at the transport roller (123b).

  As shown in FIG. 1, in the first embodiment, in order to further facilitate the processing of jammed sheets, the pair of conveyance rollers for nipping and conveying the sheet and the secondary transfer unit have a nip as the conveyance door 10 is opened and closed. Release and split. The roller group on one side forming the nip is left on the apparatus main body 100A side, and the other roller group is provided on the transport door 10 side.

  Since the conveyance path HA is largely expanded around the rotation shaft 503 arranged on the rear side of the apparatus main body 100A, the jam sheet held between the roller pair is opened by opening the conveyance door 10. The restraint can be almost completely eliminated. For this reason, jam handling and serviceability are improved.

  As shown in FIG. 2, in order to convey the recording material P to the secondary transfer portion T2, a conveyance path HA including a roller pair (not shown) is provided below the apparatus main body 100A. One of these roller pairs is arranged on the apparatus main body 100A side, and the other is arranged on the conveyance door 10 side shown in FIG.

  The mechanism for conveying the recording material P and fixing the toner image is grouped in half on the conveyance door 10 side and the apparatus main body 100A side, and the conveyance path HA of the recording material P can be developed by opening the conveyance door 10. It is. The secondary transfer roller 117 and the registration roller 123 are divided along with the opening of the conveyance door 10 in consideration of jam handling when the recording material P is jammed in the longitudinal conveyance path HA. The

  As shown in FIG. 2, when the recording material P is clogged in the transport path HA or the secondary transfer portion T2, the transport roller pair 124, the registration roller 123, and the secondary transfer portion T2 are opened by opening the transport door 10. Can be split open.

  On the other hand, the conveyance door 10 is provided with a rotation shaft below the apparatus main body 100A and is simply opened and closed by opening downward, or the entire conveyance door 10 slides in the direction in which the secondary transfer roller 117 is separated. The type is inferior in jam handling and serviceability.

  In these types, although the jam processing space can be secured by opening and closing the conveyance door 10, a part of the conveyance door 10 still remains in the front and obstructs access to the intermediate transfer belt 101.

  As shown in FIG. 1, the type in which the rotation shaft is arranged below the apparatus is different from the conveyance door 10 of the type in which the rotation shaft 503 is disposed on the back side and opened rearward. The jam processing space is reduced when the recording material is clogged in a portion close to. Further, the type in which the entire conveyance door 10 slides in the direction in which the secondary transfer roller 117 is separated requires a very large retraction amount for sliding from the main body in order to ensure sufficient jam handling performance. For this reason, the required strength of the slide mechanism is increased and the size is increased, and there is a problem that the area occupied by the image forming apparatus including the maintenance area is increased.

<Intermediate transfer unit>
FIG. 4 is an explanatory diagram of an intermediate transfer unit attachment / detachment structure, and FIG. 5 is an explanatory diagram of a configuration of the intermediate transfer unit.

  As shown in FIG. 4A, the intermediate transfer unit 115 can be pulled out to the front side of the image forming apparatus 100 integrally with the cartridge storage unit 129 with the pair of slide mechanisms 155 supporting the left and right sides. The intermediate transfer unit 115 can be detached and replaced as a whole while being pulled out to the front side of the apparatus main body 100A.

  Couplings 151, 152, and 153 that transmit driving force to the opposing roller (116: FIG. 2), the photosensitive drum (1K: FIG. 2), and the developing device (4K: FIG. 2) of the intermediate transfer unit 115 are provided on the apparatus main body 100A side. Be placed. The couplings 151, 152, and 153 release the drive transmission as the intermediate transfer unit 115 is pulled out, and fasten the drive transmission when the intermediate transfer unit 115 is pushed.

  As shown in FIG. 4B, the image forming section that forms yellow, magenta, cyan, and black toner images and transfers them to the intermediate transfer belt 101 is gathered in the intermediate transfer unit 115. The intermediate transfer unit 115 includes a cartridge storage unit 129 that stores process cartridges 103Y, 103M, 103C, and 103K.

  Couplings 141, 142, and 143 for transmitting driving force to the opposing roller (116: FIG. 2), the photosensitive drum (1K: FIG. 2), and the developing device (4K: FIG. 2) are disposed on the back surface of the cartridge storage unit 129. Has been.

  As shown in FIG. 5, a transfer frame 102 is detachably disposed so as to cover the upper part of the intermediate transfer belt 101. A coupling 141 is fixed to the shaft end of the opposing roller 116 that also serves as a drive input roller of the intermediate transfer belt 101, and the coupling 141 is connected to the coupling 151 on the apparatus main body 100A shown in FIG. The

  As shown in FIG. 3, when the secondary transfer roller 117 is separated from the intermediate transfer belt 101, if the secondary transfer roller 117 moves in the axial direction while being in pressure contact with the intermediate transfer belt 101, the intermediate transfer belt 101 has a foreign object. May adhere. Similarly, when the secondary transfer roller 117 is brought into pressure contact with the intermediate transfer belt 101, foreign matter may adhere to the intermediate transfer belt 101 in the same manner. This is because the substance contained in the secondary transfer roller 117 is strongly rubbed against the intermediate transfer belt 101 and adheres as foreign matter.

  Examples of the foreign matter are a sponge rubber material of the secondary transfer roller 117, a surface coat layer (fluorine resin type) of the secondary transfer roller 117, and an ionic conductivity adjusting agent impregnated in the secondary transfer roller 117. In some cases, the external additive of the two-component developer may adhere through these.

  If foreign matter adheres to the intermediate transfer belt 101, the primary transfer of the toner image from the photosensitive drum 1K to the intermediate transfer belt 101 is inhibited when passing through the primary transfer portion T1, and the image transferred to the recording material is prevented. There is a possibility that image defects such as uneven transfer and horizontal stripes occur. For this reason, preventing foreign matter from adhering to the intermediate transfer belt 101 needs to be reliably performed in order to improve the image quality of the output image of the image forming apparatus 100.

  On the other hand, as shown in FIG. 1, in the first embodiment, the secondary transfer roller 117 does not move in the axial direction while being in pressure contact with the intermediate transfer belt 101 as the conveyance door 10 is opened and closed. . In the process of pressing the secondary transfer roller 117 against the intermediate transfer belt 101 again after separating the secondary transfer roller 117 from the intermediate transfer belt 101, the secondary transfer roller 117 is at least in contact with the intermediate transfer belt 101. Does not move in the axial direction.

<Example 1>
6 is a perspective view of the image forming apparatus according to the first exemplary embodiment with the conveyance door removed, FIG. 7 is an explanatory view of the stopper mechanism of the conveyance door using a perspective view from above, and FIG. 8 is a diagram illustrating the rotation of the conveyance door. FIG. 9 is an explanatory diagram of a state before the transport door is completely slid and deployed.

  In FIG. 6, the conveyance door 10 shown in FIG. 1 is removed for easy understanding. In FIG. 7, (a) is a state where the conveyance door is closed, and (b) is a state where the conveyance door is open.

  As shown in FIG. 6, as a characteristic point in the configuration of the first embodiment, a pair of slide mechanisms 501 that translate the bearing portion 502 laterally are provided on the rear plate 9 of the apparatus main body 100A.

  As shown in FIG. 7A, a rail pressurizing spring 510 is set inside a slide mechanism 501 fixed to the rear plate 9, and the rail pressurizing spring 510 moves the slide mechanism 501 in the direction of arrow D. Energized.

  A rail stopper 520 is provided on the rear plate 9, and the rail stopper 520 is latched in a latch hole provided in the slide mechanism 501 in a state where the rail pressurizing spring 510 is compressed. The rail stopper 520 prevents the rail pressurizing spring 510 from extending the slide mechanism 501 and sliding the transfer door 10 to the side. The rail stopper 520 can freely control the latching / releasing to the slide mechanism 501 by operating the releasing mechanism 520M.

  The front plate 8 of the apparatus main body 100A is provided with a door stopper 521. By engaging with a hook 10F provided on the transfer door 10, the transfer door 10 is fixed to the apparatus main body 100A side in a stored state. Yes. The door stopper 521 can freely control the engagement / release of the transfer door 10 to / from the hook 10F by operating the release mechanism 521M.

  Note that the release mechanism 520M of the rail stopper 520 and the release mechanism 521M of the door stopper 521 are mechanically linked to the push button 903 shown in FIG. 9, and both stopper release operations are performed by pushing the push button 903. Are made at the same time.

  As shown in FIG. 8, a counter roller 116 is disposed inside the intermediate transfer belt 101, and a secondary transfer roller 117 is disposed at a position facing the counter roller 116.

  The secondary transfer roller 117 is supported by the inner door 20 that also serves as a support frame for the secondary transfer roller 117, and the inner door 20 is rotatable about the rotation shaft 27 in the direction of arrow E on the conveyance door 10. It is attached.

  The opposing roller 116 and the secondary transfer roller 117 form a nip as shown in FIG. 7A to constitute a secondary transfer portion (T2: FIG. 3) that transfers the toner image to the recording material.

  The opening operation | movement of the conveyance door 10 in the structure of Example 1 is demonstrated below.

  As shown in FIG. 7A, in a state where the conveyance door 10 is closed, the opposing roller 116 and the secondary transfer roller 117 are predetermined by a pair of roller pressure springs 24 provided inside the inner door 20. Contact with pressure.

  In this state, the conveyance door 10 is in contact with the rear side plate 9 in the vicinity of the rotation shaft 503, and the conveyance door 10 cannot be rotated by being a stopper.

  When the push button 903 shown in FIG. 9 is pressed, the release mechanism 520M is operated to release the rail stopper 520 provided on the rear plate 9, and at the same time, the release mechanism 521M is operated to operate the front plate 8. The door stopper 521 provided in is also released.

  At this time, as shown in FIG. 7B, the conveying door 10 holds the inner door 20 and the secondary transfer roller 117 by the pressing force of the rail pressing spring 510 and the reaction force of the roller pressing spring 24. Slide and move in the direction of arrow D.

  Thereby, the conveyance door 10 shifts to a half-open protruding state as shown in FIG. 8 with respect to the apparatus main body 100A.

  At this time, the conveyance door 10 translates the secondary transfer roller 117 in a direction set in a direction perpendicular to the axis of the opposing roller 116 as shown in FIG. For this reason, the secondary transfer roller 117 does not slide at all with respect to the intermediate transfer belt 101 in the axial direction.

  Therefore, the surface layer component of the secondary transfer roller 117 does not adhere to the secondary transfer belt 101, and thus the surface layer component attached to the intermediate transfer belt 101 does not cause transfer unevenness.

  When the slide operation is performed in the direction set in the vertical direction to the state shown in FIG. 7B, the contact between the transfer door 10 and the rear plate 9 in the vicinity of the rotation shaft 503 is also released. For this reason, as shown in FIG. 8, the transport door 10 is rotatable rearward about a rotation shaft 503 provided on the rear side of the apparatus main body 100 </ b> A.

  As shown in FIG. 8, the rotation shaft 503 is disposed further to the rear side of the apparatus main body 100A than the sheet passing area of the recording material conveyed in the vertical direction along the conveyance path. For this reason, it is possible to easily take out the jam sheet from the conveyance path in a state where the conveyance door 10 is opened around the rotation shaft 503. And since the conveyance door 10 does not remain on the front side by developing in the direction of arrow E, it is possible to secure a wide processing space for jam sheets and to provide a configuration with high jam processing performance.

  As shown in FIG. 9, the retraction amount due to the sliding movement of the conveyance door 10 may be retreated so that the nip between the opposing roller 116 and the secondary transfer roller 117 is separated, and it is sufficient to retreat 10 mm. For this reason, although it is a slide mechanism, an especially strong structure and mechanism are not required.

  In the subsequent operation, as shown in FIG. 8, the transfer door 10 may be opened from the front side to the rear side and brought to the unfolded state shown in FIG. 1.

Therefore, according to the configuration of the first embodiment,
(1) The support mechanism of the secondary transfer roller 117 is slid in a direction perpendicular to the opposing roller 116 to release the pressure from the opposing roller 116 and the secondary transfer roller 117.
(2) The conveyance door 10 is opened around the rotation shaft 503 at the rear of the apparatus main body 100A.

  The two operations are reliably performed without making a mistake in the order by preventing the rotation of the conveyance door 10 by the guide structure of the conveyance door 10 by the rear side plate 9 as the limiting mechanism.

In addition, what is necessary is just to take the procedure contrary to the said description, when closing the conveyance door 10. FIG. That is,
(2) The transfer door 10 is closed around the rotation shaft 503 at the rear of the apparatus main body 100A.
(1) The support mechanism of the secondary transfer roller 117 is slid vertically toward the counter roller 116 to pressurize the counter roller 116 and the secondary transfer roller 117.

  Even in this case, when the conveyance door 10 is first slid, the opened conveyance door 10 interferes with the corners of the rear side plate 9, and the conveyance door 10 cannot be slid. Therefore, a malfunction in which the secondary transfer roller 117 is brought into contact with and pressed against the intermediate transfer belt 101 while the conveyance door 10 is rotated and closed cannot occur.

  In other words, even when the transport door 10 is closed, operations necessary to prevent the secondary transfer roller 117 from sliding in the axial direction with respect to the intermediate transfer belt 101 are executed without any mistake in order by the limiting mechanism.

  By performing the opening / closing operation of the conveyance door 10 in this way, the secondary transfer roller 117 and the intermediate transfer belt 101 are not slid in the axial direction, and jam handling and serviceability are sacrificed. And no image defect occurs.

<Example 2>
FIG. 10 is a perspective view of the image forming apparatus according to the second embodiment with the conveyance door removed, FIG. 11 is an explanatory view of the state where the conveyance door is rotated outward, and FIG. 12 is an explanatory view of the opening operation of the conveyance door. .

  The second embodiment is configured in the same manner as the first embodiment except that the mechanism for sliding outward in the first embodiment is replaced with a mechanism for rotating outward. Therefore, in FIGS. 10 to 12, the same components as those in the first embodiment are denoted by the same reference numerals and redundant description is omitted.

  As shown in FIG. 10, the characteristic point of the second embodiment is that the apparatus is rotated in the direction of arrow F by a rotation shaft 601 provided below the apparatus main body 100A so as to be parallel to the opposing roller 116. Thus, the door support frame 600 is provided so as to be inclined freely.

  The door support frame 600 is provided with a shaft hole 602 for supporting the rotation shaft 503 of the transfer door 10 shown in FIG. 1, and the door support frame 600 is urged in the direction of arrow F1 by a spring (not shown). .

  Further, as shown in FIG. 7A, the rear side plate 9 includes a rail stopper 520 and a release mechanism 520M as a configuration for preventing the spring (inclination) of the door support frame 600 in the direction of the arrow F1 by the spring. And are provided. The front plate 8 is provided with a door stopper 521 and a release mechanism 521M as a configuration that prevents the conveyance door 10 from rotating (tilting) around the rotation shaft 503.

  The release mechanism 520M of the rail stopper 520 and the release mechanism 521M of the door stopper 521 are linked to the push button 903 shown in FIG. 11, and when the push button 903 is pressed, the rail stopper 520 shown in FIG. Release operation of the door stopper 521 is performed.

  These stopper mechanisms are similar in configuration to the rail stopper 520 and the door stopper 521 in the first embodiment, and have the same functions and controls.

  The opening operation | movement of the conveyance door 10 in the structure of Example 2 is demonstrated below.

  As shown in FIG. 10, first, by pushing the push button 903, the rail stopper 520 is released, and the door support frame 600 rotates around the rotation shaft 601.

  The conveying door 10 biased toward the outside is centered on the rotation shaft 601 as shown in FIG. 11 while holding the inner door 20 and the secondary transfer roller 117 as shown in FIG. 7B. Then, it rotates in the direction of arrow F1 and stops in a semi-open state protruding sideways.

  At this time, the rotation operation of the transport door 10 toward the outside is performed around the rotation shaft 601 parallel to the opposing roller 116, so that the secondary transfer is performed on the intermediate transfer belt 101 as in the first embodiment. The roller 117 does not slide in the axial direction.

  Accordingly, the surface layer component of the secondary transfer roller 117 does not adhere to the intermediate transfer belt 101, and transfer unevenness caused by the attached surface layer component can be prevented.

  As shown in FIG. 12, the operation after the secondary transfer roller 117 is separated from the intermediate transfer belt 101 is the same as that of the first embodiment. As shown in FIG. 8, the conveyance door 10 may be opened from the front side to the rear centering on the rotation shaft 503 and brought into the unfolded state as shown in FIG. 1.

Therefore, also in the configuration of the second embodiment, the moving mechanism (601) moves the support mechanism (10) so that the entire transfer roller (117) moves away from the image carrier (101). And
(1) The support mechanism for the secondary transfer roller 117 is rotated in a direction perpendicular to the opposing roller 116 to release the pressure from the opposing roller 116 and the secondary transfer roller 117.
(2) The conveyance door 10 is opened around the rotation shaft 503 at the rear of the apparatus main body 100A.

  The two operations are reliably performed without making a mistake in order by the guide surface of the rear plate 9 serving as the limiting mechanism preventing the conveyance door 10 from rotating.

In addition, what is necessary is just to take the procedure contrary to the said description, when closing the conveyance door 10. FIG. That is,
(2) The transfer door 10 is closed around the rotation shaft 503 at the rear of the apparatus main body 100A.
(1) The support mechanism of the secondary transfer roller 117 is rotated toward the opposing roller 116 to press the secondary transfer roller 117 against the opposing roller 116.

  Even in this case, when the conveyance door 10 is first rotated in the direction opposite to the arrow F1, the opened conveyance door 10 interferes with the corner of the rear plate 9, so that the conveyance door 10 is centered on the rotation shaft 601. Can not rotate. Accordingly, there is no possibility of erroneous operation of bringing the secondary transfer roller 117 into contact with and pressurizing the intermediate transfer belt 101 while closing the conveyance door 10 around the rotation shaft 601.

  That is, even when the transport door 10 is closed, the guide structure of the transport door 10 by the rear plate 9 as a limiting mechanism does not slide the secondary transfer roller 117 in the axial direction with respect to the intermediate transfer belt 101. The guide structure of the conveyance door 10 by the rear side plate 9 as the limiting mechanism allows the operation sequence in which the secondary transfer roller 117 is not slid on the intermediate transfer belt 101 when the conveyance door 10 is opened and closed to be executed without mistake.

  By performing the opening / closing operation of the conveyance door 10 in this way, the secondary transfer roller 117 and the intermediate transfer belt 101 are not slid in the axial direction, and jam handling and serviceability are sacrificed. And no image defect occurs.

  As described in detail with reference to the first and second embodiments, by adopting the configuration of the present invention, the secondary transfer roller (transfer roller) can be used even when the conveyance door 10 is rotated and developed backward. ) 117 and the registration roller 123 are not slid in the axial direction. Accordingly, it is possible to realize an image forming apparatus that does not cause transfer unevenness due to a substance attached from the secondary transfer roller (transfer roller) 117 without sacrificing jam handling and serviceability.

<Modification>
The present invention is not limited to the forms shown in the first and second embodiments. In the first and second embodiments, the main body configuration of the image forming apparatus 100 is an intermediate transfer configuration in which a toner image formed on a photosensitive drum is primarily transferred to an intermediate transfer belt 101 and then secondarily transferred to a recording material. This may be a direct transfer configuration in which the toner image is directly transferred from the photosensitive drum to the recording material.

  That is, even if the photosensitive drum is provided at the position of the opposing roller 116 in FIG. 2, the secondary transfer roller (transfer roller) 117 rubs against the image carrier in the axial direction and affects the image. Is the same. For this reason, the effect by applying this invention is also the same.

  Also, in the system in which the rotation shaft 503 is translated to the side using a link mechanism in which levers are arranged on the upper and lower sides, the conveyance door is not rotated until the secondary transfer roller is completely separated from the image carrier. The present invention can be implemented with a possible restriction mechanism.

  The limiting mechanism is not limited to a structure that guides the conveyance door in the separation direction in the vicinity of the rotation shaft 503. You may replace with the mechanism which locks rotation of a conveyance door until separation is completed.

  With reference to FIG. 6, as shown in FIGS. 7A and 7B, the release mechanism 520M is first operated in response to the operation of the push button 903, and the release mechanism 521M is operated later. Also good. The door stopper 521 may be configured to be slidable together with the transport door 10 in a state where the door stopper 521 is engaged with the hook 10F, and the door stopper 521 may be disengaged from the hook 10F after the slide movement of the transport door 10 is completed. In this case, since the door stopper 521 and the hook 10F function as a limiting mechanism, it is not necessary to provide a limiting mechanism in which the rear plate 9 guides the conveyance door 10 in the vicinity of the rotation shaft 503.

<Comparative example>
13 is a perspective view of an image forming apparatus of a comparative example, FIG. 14 is a perspective view of a state in which the conveyance door is opened rearward, and FIG. 15 is an explanation of sliding of the intermediate transfer belt and the secondary transfer roller when the conveyance door is opened and closed. FIG.

  The comparative example is configured in substantially the same way as in Example 1 except that it does not have a mechanism for sliding outward in Example 1. Therefore, in FIGS. 13 to 15, the components common to the first embodiment are denoted by the same reference numerals as those in FIGS.

  As shown in FIG. 13, the image forming apparatus 200 of the comparative example can open the front door 400 to the front side and further open the front side of the cartridge storage unit 129. In this state, the process cartridges 103Y, 103M, 103C, and 103K can be replaced.

  A conveyance door 10J is provided on the right side surface of the apparatus main body 200A, and the intermediate transfer belt 101 supported by the opposing roller 116 can be accessed by opening the conveyance door 10J rearward.

  As shown in FIG. 14, the image forming apparatus 200 has the rotation axis of the transport door 10 </ b> J on the back side of the apparatus main body 200 </ b> A to improve jam handling and serviceability. However, the conveyance door 10J is simply rotated in the direction of arrow C and opened, and the conveyance door 10J is slid in a direction perpendicular to the surface of the intermediate transfer belt 101 as in the first embodiment. There is no mechanism to make it.

  By opening the transfer door 10J from the front side to the back side by approximately 90 degrees, the entire area of the vertical path portion of the transfer path HA provided on the right side of the apparatus main body 200A can be substantially exposed. For this reason, the jam processing property is good. Further, the secondary transfer roller 117 is opened and closed by rotating substantially in parallel in the axial direction, so that the secondary transfer roller 117 and the intermediate transfer belt 101 are prevented from coming into contact with each other as the transport door 10J is opened and closed. The resulting damage is avoided.

  As shown in FIG. 15A, the inner door 20 is provided with a pair of rollers on the conveyance path to be divided and opened, and the rotation shaft 27 of the inner door 20 is disposed on the back side on the conveyance door 10. As a result, even when the conveyance door 10J is opened and closed, the secondary transfer roller 117 is in contact with the intermediate transfer belt 101 substantially horizontally, and the intermediate transfer belt 101 is prevented from being damaged due to contact of the secondary transfer roller 117 with one piece. ing.

  However, in the process of closing the conveyance door 10J and pressurizing the secondary transfer roller 117, the secondary transfer roller 117 moves in the axial direction after contacting the intermediate transfer belt 101 supported by the opposing roller 116.

  As shown in FIG. 15B, in the process of closing the conveyance door 10J in the direction of the arrow C1, the outer secondary transfer roller 117 moves in the axial direction by a distance L3.

  As a result, the surface layer component of the secondary transfer roller 117 is rubbed and attached to the intermediate transfer belt 101, and a difference in image transfer performance occurs between the surface and the non-attached portion. Could be formed.

  On the other hand, in the first embodiment, the second embodiment, and the modified example described above, the roller pair is divided and opened by opening the transport door 10 from the front side to the back side with the rotation shaft 503 as the back side. Therefore, it is possible to realize a door opening / closing configuration that does not impair jam handling and serviceability.

  When the conveyance door 10 is opened and closed in the image forming apparatus having the vertical path configuration, the secondary transfer portion T2 is separated and opened in the horizontal direction with respect to the roller axis. The door is opened and closed as the center.

  Therefore, the conveyance door 10 can be opened and closed without accompanying movement and sliding of the secondary transfer roller 117 in the axial direction, and the surface layer of the secondary transfer roller 117 can be rubbed against the intermediate transfer belt 101. No. The secondary transfer roller 117 is not rubbed in the axial direction when the transport door 10 is opened and closed, and a configuration that does not cause streak images or density unevenness is realized.

1 is a perspective view of an image forming apparatus according to a first embodiment. 2 is an explanatory diagram of an internal configuration of an image forming apparatus. FIG. It is explanatory drawing of a structure of a process cartridge. FIG. 6 is an explanatory diagram of an intermediate transfer unit attachment / detachment structure. It is an explanatory diagram of a configuration of an intermediate transfer unit. FIG. 3 is a perspective view of the image forming apparatus according to the first exemplary embodiment with a conveyance door removed. It is explanatory drawing of the stopper mechanism of the conveyance door using the perspective view from an upper surface. It is explanatory drawing of the state which rotated and extended the conveyance door. It is explanatory drawing of the state before a conveyance door completes a slide and is expand | deployed. FIG. 6 is a perspective view illustrating a state where a conveyance door is removed in the image forming apparatus according to the second exemplary embodiment. It is explanatory drawing of the state which rotated the conveyance door to the outer side. It is explanatory drawing of opening operation of a conveyance door. It is a perspective view of the image forming apparatus of a comparative example. It is a perspective view of the state where the conveyance door was opened backward. FIG. 6 is an explanatory diagram of sliding between an intermediate transfer belt and a secondary transfer roller when the conveyance door is opened and closed.

Explanation of symbols

9 Limit mechanism, guide structure (rear side plate)
10, 20 Support mechanism (conveyance door, inner door)
100 Image forming apparatus 101 Image carrier (intermediate transfer belt)
117 Transfer roller (secondary transfer roller)
123 Transport path (registration roller)
501, 601 Movement mechanism, rotation mechanism (slide mechanism, rotation axis)
503 Rotating mechanism (rotating shaft)
520 Rail stopper 520M, 521M Release mechanism 521 Door stopper 903 Push button T2 Transfer part (secondary transfer part)
P Recording material

Claims (13)

A transfer roller that forms a transfer portion for transferring the toner image in contact with an image carrier that carries the toner image;
A support mechanism for supporting both ends of the transfer roller and urging the transfer roller toward the image carrier,
A moving mechanism for moving the support mechanism so that the transfer roller is spaced apart from the image carrier in parallel;
A facing portion between the transfer roller and the image carrier is opened around a rotation shaft provided at one end side in the rotation axis direction of the transfer roller and perpendicular to the rotation axis of the transfer roller. A rotation mechanism for rotating the support mechanism so that,
A restriction mechanism that restricts rotation of the support mechanism by the rotation mechanism until at least the transfer roller is separated from the image carrier along with the movement of the support mechanism by the movement mechanism ;
The moving mechanism is a parallel separating slide mechanism that translates the support mechanism in a direction perpendicular to the rotation axis of the transfer roller,
The image forming apparatus according to claim 1, wherein the restriction mechanism is a guide structure that guides the support mechanism in the orthogonal direction at a position away from a rotation axis of the rotation mechanism . Provided on the side of the device main body, equipped with a chassis door that can be opened and closed by rotating around the chassis door rotation axis,
The image forming apparatus according to claim 1, wherein the support mechanism is attached to the housing door. A conveyance path for feeding the recording material to the transfer unit is disposed below the transfer unit,
The support mechanism further supports a transport roller located on the housing door side of the transport roller pair provided in the transport path, and opens the housing door to thereby contact the transport roller pair. 3. The image forming apparatus according to claim 2, wherein the conveyance path including the image forming unit and the facing portion between the transfer roller and the image carrier are integrally opened. A rear plate provided at the rear of the apparatus body,
The image forming apparatus according to claim 2, wherein the parallel separation slide mechanism is a pair of mechanisms installed on the rear side plate. The image forming apparatus according to claim 4 , further comprising an inner door that is provided in the support mechanism and is pivotally mounted about the pivot shaft. The pair of transfer roller pressing members are provided on the inner door, and the transfer roller is pressed by the transfer roller pressing member when the housing door is closed. Image forming apparatus. The limiting mechanism includes the housing door and the rear plate, and the housing door is in contact with a guide surface that guides the housing door of the rear plate, thereby restricting the rotation operation of the housing door. The image forming apparatus according to any one of claims 4 to 6. Said having parallel spaced slide mechanism sliding mechanism pressurizing member, any said slide mechanism pressure member of claim 4 to 7, characterized in that the biasing in the direction of the perpendicular to the parallel spaced slide mechanism whether the image forming apparatus according to (1). A slide stopper is installed on the rear plate, and the slide stopper is latched in a latch hole provided in the parallel separation slide mechanism in a state where the slide mechanism pressurizing member is compressed. The image forming apparatus according to claim 4. A slide mechanism release mechanism that enables the parallel separation slide mechanism to be latched and released, and the slide stopper operates the slide mechanism release mechanism to engage and release the parallel separation slide mechanism. The image forming apparatus according to claim 9, wherein the image forming apparatus is freely controlled. A front plate provided on the front side of the apparatus body;
A chassis door stopper provided on the front side plate and stopping the chassis door;
A hook provided on the housing door,
The image forming apparatus according to claim 10, wherein the casing door is stopped in a state where the casing door is closed to the apparatus main body by engaging the casing door stopper and the hook. A housing door release mechanism that enables engagement and release of the housing door stopper and the hook,
12. The slide mechanism release mechanism and the chassis door release mechanism are mechanically linked, and the slide stopper and the chassis door stopper can be simultaneously released by operating a common operation unit. The image forming apparatus described in 1. The moving mechanism is a parallel separating rotation mechanism that rotates the support mechanism around a rotation axis provided in a direction parallel to the rotation axis of the transfer roller;
The image forming apparatus according to claim 1, wherein the restriction mechanism is a guide structure that guides the support mechanism in the orthogonal direction at a position away from a rotation axis of the rotation mechanism.

Images