JP4835740B2 - Image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfactorily transfer a driving force even when the center axis of a passive member provided in a moving member is deviated from the center axis of a body driving member provided in an apparatus body. <P>SOLUTION: A coupling member 65 is supported to the body driving member (body driving gear 62) movably in an axial direction, and is engaged therewith in a rotation direction. An Oldham member 66 is movable in the axial direction integrally with the coupling member 65, and is configured to be engageable with the coupling member 65 and the passive member (photosensitive drum 47A) in the rotation direction. A first connection being a part engaged with the coupling member 65 and the Oldham member 66 is engaged each other by irregularities (second recess 65K and second protrusion 66B) so as to be movable in a first diameter direction, and a second connection being a part engaged with the Oldham member 66 and the passive member is engaged each other by irregularities (third protrusion 66D and third recess A1) so as to be movable in a second diameter direction perpendicular to the axial direction and the first diameter direction. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus including a moving member movable with respect to an apparatus main body and a mechanism for transmitting a driving force from the apparatus main body to a passive member provided on the moving member.

  2. Description of the Related Art Conventionally, there has been known an image forming apparatus including a photosensitive drum that rotates while carrying a toner image, and a driving coupling that transmits a driving force to the photosensitive drum (see Patent Document 1). Specifically, with this technology, the drive coupling can be moved back and forth in the axial direction, so that it can be attached to and detached from the hole formed at the end of the photosensitive drum. The coupling and the photosensitive drum are engaged with each other in the circumferential direction and rotate integrally.

JP 2005-265951 A

  By the way, when the cartridge having the photosensitive drum is detachable from the apparatus main body, the cartridge may be mounted on the apparatus main body in a state where the central axis of the photosensitive drum and the central axis of the drive coupling are shifted. There is. In this case, in the above-described technique, even if the drive coupling enters the hole formed in the end portion of the photosensitive drum, the drive coupling is brought close to one side of the inner peripheral surface of the hole of the photosensitive drum and strongly driven. In some cases, force transmission was not performed well.

  Accordingly, the present invention provides a central axis of a passive member (for example, a photosensitive drum) that is rotatably provided on a moving member that is movable with respect to the apparatus main body, and a main body drive member (for example, drive coupling) that is rotatably provided on the apparatus main body. It is an object of the present invention to provide an image forming apparatus capable of satisfactorily transmitting a driving force even when the center axis is deviated.

  In order to solve the above problems, an image forming apparatus according to the present invention includes an apparatus main body, a movable member movable between a storage position in the apparatus main body, and a disengagement position outside the apparatus main body, and the apparatus main body. A main body drive member that is rotatably provided to transmit a driving force from a drive source, and an axial direction of the main body drive member that is rotatably provided to the moving member and is located at the storage position. The main body driving member is disposed between the passive member facing the main body driving member, the main body driving member and the passive member, and engaged with the main body driving member and the passive member in the rotational direction. A driving force transmission member that transmits a driving force to the passive member, and the driving force transmission member is movable in the axial direction with respect to the main body driving member. Connection with member Separation can be switched, and the driving force transmission member has a coupling member arranged on the main body driving member side and an Oldham member arranged on the passive member side, and the coupling member The coupling member is supported by the main body drive member so as to be movable in the axial direction and is engaged in the rotational direction so that the Oldham member is movable in the axial direction integrally with the coupling member. And a first connecting portion that is configured to be engageable with the coupling member and the passive member in the rotational direction, and is a portion where the coupling member and the Oldham member are engaged in the rotational direction. Are engaged with each other so as to be movable in a first radial direction orthogonal to the axial direction, and the Oldham member and the passive member are engaged in the rotational direction. The second connecting portion is a portion that is, the axial direction so as to be movable in a second radial direction perpendicular to said first radial direction, and wherein the engaged in a concavo-convex each other.

  According to the present invention, even when the center axis of the passive member and the center axis of the main body drive member are deviated, the Oldam member is engaged with the passive member and the coupling member in a concavo-convex manner in the first radial direction. In addition, since it is movable in the second radial direction orthogonal to this, the Oldham member transmits power while sliding with respect to the passive member and the coupling member as if the Oldham joint. Therefore, the driving force can be transmitted from the main body driving member to the passive member through the driving force transmitting member.

  According to the present invention, even when the center axis of the passive member and the center axis of the main body drive member are deviated, the transmission of the driving force is excellent by the Oldham member movable in the first radial direction and the second radial direction. Can be done.

1 is a cross-sectional view illustrating an overall configuration of a color laser printer according to an embodiment. It is sectional drawing which shows the state which pulled out the drawer from the apparatus main body. It is a disassembled perspective view which decomposes | disassembles and shows a driving force transmission mechanism. A sectional view (a) of the driving force transmission mechanism cut in the first radial direction, a sectional view (b) cut in the second radial direction, the relationship between the engaging claw and the engaging concave portion, and the first convex portion and the first convex portion. It is explanatory drawing (c) which shows simply the relationship with 1 recessed part. (A), (b) is explanatory drawing which shows a detachment mechanism simply. FIG. 6 is a cross-sectional view (a) showing a state where the driving force transmission member is connected to the photosensitive drum, and a cross-sectional view (b) showing a state where the driving force transmission member is separated from the photosensitive drum.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings as appropriate. In the following description, first, the overall configuration of a color laser printer as an example of an image forming apparatus according to an embodiment will be briefly described, and thereafter, characteristic portions of the present invention will be described in detail.

<Overall configuration of color laser printer>
As shown in FIG. 1, the color laser printer 1 includes a paper feeding unit 30 that supplies paper P into the apparatus main body 2 and an image forming unit 40 that forms an image on the paper P fed from the paper feeding unit 30. And a paper discharge unit 50 for discharging the paper P coming out of the image forming unit 40 from the inside of the apparatus main body 2.

  Note that the vertical, horizontal, and front-back directions indicated by arrows in FIG. 1 are directions viewed from a person standing in front (front side) of the color laser printer 1. Unless otherwise specified, the directions are in accordance with the directions indicated by arrows in FIG.

  An opening 2A for attaching / detaching a drawer 45 as an example of a moving member to be described later is formed on the front wall of the apparatus main body 2, and a front cover 21 for opening and closing the opening 2A is swingably provided. ing.

  The paper feed unit 30 includes a paper feed tray 31 that can be attached to and detached from the apparatus main body 2 and a paper supply mechanism 32 that conveys the paper P from the paper feed tray 31 to the image forming unit 40.

  The image forming unit 40 includes a scanner unit 41, a process unit 42, a transfer unit 43, and a fixing unit 44.

  Although not shown, the scanner unit 41 includes a laser light emitting unit, a polygon mirror, a plurality of lenses, and a reflecting mirror. The scanner unit 41 emits laser light corresponding to each color of cyan, magenta, yellow, and black to each photosensitive drum 47 </ b> A of the process unit 42.

  The process unit 42 includes a drawer 45 that is disposed between the scanner unit 41 and the transfer unit 43 and is detachably attached to the apparatus main body 2. The drawer 45 is movable between a storage position (position in FIG. 1) in the apparatus main body 2 and a disengagement position (position in FIG. 2) outside the apparatus main body 2 in a state where the front cover 21 is opened. Yes. In the drawer 45, four (plural) process cartridges 46 are arranged along the transport direction of the paper P.

  The “separation position” indicates a position where the drawer 45 has moved from the “storage position”. Therefore, for example, the drawer 45 may be configured to be detachable from the apparatus main body 2 or may be configured not to be removable from the apparatus main body 2.

  Each process cartridge 46 includes a drum subunit 47 disposed at a lower portion, a developing unit 48 that is detachably connected to the drum subunit 47, and a developer cartridge 49 that is detachably connected to the developing unit 48. ing.

  The drum subunit 47 includes a photosensitive drum 47A as an example of a passive member (photosensitive member), a charger (reference numeral omitted), and the like. The photosensitive drum 47A is rotatably supported by the drum subunit 47. That is, the photosensitive drum 47 </ b> A is indirectly supported by the drawer 45 via the drum subunit 47.

  The developing unit 48 includes a developing roller 48B, a supply roller 48A, and the like. Each developer cartridge 49 contains non-magnetic one-component toner (developer) of each color of cyan, magenta, yellow, and black.

  In the process unit 42 configured as described above, the surface of the photosensitive drum 47A charged by the charger is exposed by the laser light emitted from the scanner unit 41, so that the potential of the exposed portion is lowered, and the photosensitive drum An electrostatic latent image based on the image data is formed on 47A. Further, the toner is carried on the photosensitive drum 47A by supplying the toner to the electrostatic latent image on the photosensitive drum 47A by the developing roller 48B in contact with the photosensitive drum 47A.

  The transfer unit 43 includes a drive roller 43A, a driven roller 43B, a transport belt 43C, and a transfer roller 43D. In the transfer unit 43, when the paper P transported by the transport belt 43C is supplied between the photosensitive drum 47A and the transfer roller 43D, the toner image on the photosensitive drum 47A is transferred to the paper P.

  The fixing unit 44 includes a heating roller 44A and a pressure roller 44B. The fixing unit 44 heats and fixes the toner image on the paper P by feeding the paper P while sandwiching it between the heating roller 44A and the pressure roller 44B.

  The paper discharge unit 50 has a plurality of conveyance rollers (reference numerals omitted), and conveys the paper P discharged from the fixing unit 44 to the upper paper discharge tray 53.

<Mechanism for transmitting driving force to photosensitive drum>
Next, a driving force transmission mechanism to the photosensitive drum 47A, which is a characteristic part of the present invention, will be described. In FIG. 3 to be referred to, for the sake of convenience, the photosensitive drum 47A is rotated relative to the time direction so that the end surface of the photosensitive drum 47A can be seen.

  As shown in FIG. 3, a driving force transmission mechanism 60 that transmits a driving force to the photosensitive drum 47A includes a driving source 61 such as a motor, a main body driving gear 62 as an example of a main body driving member, and an example of an urging member. The coil spring 63 and the driving force transmission member 64 are provided.

  The drive source 61 is provided at an appropriate position of the apparatus main body 2 and transmits a driving force to the main body drive gear 62 directly or indirectly via the gear.

  The main body drive gear 62 is rotatably provided in the apparatus main body 2 and mainly includes a gear portion 62A to which the driving force 61 is transmitted from the driving source 61 and a driving force transmission member 64 from the center portion of the gear portion 62A. And a projecting portion 62B projecting toward the end. A pair of first recesses 62 </ b> C along the axial direction of the main body drive gear 62 are provided on the outer peripheral surface of the protrusion 62 </ b> B so as to face each other with the rotation shaft interposed therebetween. In addition, a pair of engaging recesses 62D are formed between the first recesses 62C (positions separated by approximately 90 ° in the rotation direction) on the outer peripheral surface of the protrusion 62B.

  A locking rib 62E as an example of a locking portion protruding outward in the radial direction of the main body driving gear 62 is formed at the end of each engaging recess 62D on the driving force transmission member 64 side (see FIG. 4 (b)).

  Further, a cylindrical extending portion 62F having a smaller diameter than the protruding portion 62B is extended from the leading end surface of the protruding portion 62B so as to protrude in the axial direction.

  The coil spring 63 is disposed between the main body driving gear 62 and the driving force transmission member 64 (specifically, a coupling member 65 described later), and the main body driving gear 62 and the driving force transmission member 64 are separated from each other. Is energized.

  The driving force transmission member 64 is disposed between the main body driving gear 62 and the photosensitive drum 47A, and is engaged with the main body driving gear 62 and the photosensitive drum 47A in the rotation direction, thereby causing the main body driving gear 62 to be in contact with the photosensitive drum 47A. Driving force is transmitted to Further, the driving force transmission member 64 is supported by the main body driving gear 62 so as to be movable in the axial direction, whereby the connection / disconnection of the driving force transmission member 64 and the photosensitive drum 47A can be switched.

  Specifically, the driving force transmission member 64 has a coupling member 65 disposed on the main body driving gear 62 side and an Oldham member 66 disposed on the photosensitive drum 47A side.

  The coupling member 65 is a member that is supported by the main body drive gear 62 so as to be movable in the axial direction, and that is engaged in the rotational direction, and includes a cylindrical portion 65A into which the protruding portion 62B of the main body drive gear 62 enters, and a cylindrical portion 65A. The end of the Oldham member 66 is closed, and the wall 65B facing the Oldham member 66 is mainly included.

  An annular flange 65C extending radially outward is formed on the outer peripheral surface of the cylindrical portion 65A, and the annular flange 65C and the gear portion 62A of the main body drive gear 62 are pressed away from each other by the coil spring 63 described above. ing.

  A pair of first convex portions 65 </ b> D along the axial direction are provided on the inner peripheral surface of the cylindrical portion 65 </ b> A so as to face each other with the rotation axis interposed therebetween. The first convex portion 65 </ b> D is movable relative to the first concave portion 62 </ b> C in the axial direction and engages in the rotational direction when it enters the first concave portion 62 </ b> C of the main body driving gear 62.

  Further, a locking claw 65E as an example of a locking portion is opposed to each other between the first convex portions 65D (positions separated by about 90 ° in the rotation direction) of the cylindrical portion 65A across the rotation shaft. A pair is provided as described above (see FIG. 4B). The locking claw 65E protrudes inward from the inner peripheral surface of the cylindrical portion 65A and enters each engagement recess 62D of the main body drive gear 62, thereby engaging with the locking rib 62E in the axial direction.

  Furthermore, a pair of slits 65F extending in the axial direction and extending through the end surface of the cylindrical portion 65A are formed on both sides in the circumferential direction of the locking claw 65E. As a result, when the cylindrical portion 65A of the coupling member 65 is fitted into the protruding portion 62B of the main body drive gear 62, the locking claw 65E is bent well and the rear locking rib 62E is moved over the locking rib 62E in the axial direction. It comes to engage with. The engagement of the locking claw 65E with the locking rib 62E in this way restricts the coupling member 65 from moving toward the photosensitive drum 47A, and the coupling member 65 is disengaged from the main body drive gear 62. Is suppressed.

  Furthermore, as shown in FIG. 4C, the locking claw 65 </ b> E is formed so that its protruding amount and width are smaller than the first convex portion 65 </ b> D (a convex portion that is not configured as a locking claw). Thus, it is formed at a position farther from the surface of the recess (engagement recess 62D) than the first protrusion 65D. Thereby, when the cylinder portion 65A of the coupling member 65 moves relative to the protrusion 62B of the main body drive gear 62 in the radial direction or the rotation direction, the locking claw 65E contacts the engagement recess 62D. Before, the 1st convex part 65D which is not comprised as the latching claw 65E contacts the 1st recessed part 62C. Therefore, the engaging claw 65E is prevented from being brought into contact with the engaging recess 62D and being broken by the engagement between the first protrusion 65D and the first recess 62C.

  As shown in FIG. 3, a circular hole 65G into which the extended portion 62F of the main body drive gear 62 enters is formed at the center of the wall 65B. As a result, the hole 65G on one end side in the axial direction and the first convex portion 65D on the other end side, that is, both end portions of the coupling member 65 are supported by the main body drive gear 62. It can be moved stably in the axial direction.

  Specifically, the hole 65G is formed in a cylindrical shape that is long in the axial direction, as shown in FIG. Therefore, the extended portion 62F and the hole portion 65G come into contact with each other, and the movement of the coupling member 65 in the axial direction is more stable.

  In addition, a tapered surface 65H whose diameter decreases from the main body drive gear 62 side toward the Oldham member 66 side is formed at the end of the hole 65G on the main body drive gear 62 side. As a result, the coupling member 65 moves away from the main body drive gear 62 to a position where the hole 65G is likely to be removed from the extended portion 62F, and even when the coupling member 65 is eccentric with respect to the main body drive gear 62, the coupling member 65 Is pushed toward the main body drive gear 62, and is guided by the taper surface 65H so that the hole 65G fits into the extended portion 62F satisfactorily.

  As shown in FIG. 3, the wall 65B has a pair of second recesses 65K and a pair of long holes 65L.

  The pair of second recesses 65K are provided so as to face each other in the radial direction across the hole 65G, and are respectively formed as grooves that are wide along the facing direction (hereinafter referred to as “first radial direction”). ing. A pair of second convex portions 66B formed on an Oldham member 66, which will be described later, enters each second concave portion 65K so as to be movable in the first radial direction and engageable in the rotational direction. (See FIG. 4A). That is, in this embodiment, the 1st connection part is comprised by the 2nd convex part 66B and the 2nd recessed part 65K.

  The pair of long holes 65L are provided so as to face each other across the hole 65G in a radial direction orthogonal to the first radial direction (hereinafter referred to as “second radial direction”), and the longitudinal direction thereof is the first diameter. It is formed as a through hole along the direction. A pair of flexibly deformable hook portions 66C formed on an Oldham member 66, which will be described later, are movable in the first radial direction and engage with each other in the axial direction at the inner edge of each elongated hole 65L. It has become. As a result, the Oldham member 66 is attached to the coupling member 65 and can move in the axial direction integrally with the coupling member 65 and can move in the first radial direction with respect to the coupling member 65. Yes.

  The Oldham member 66 includes a disk-shaped base portion 66A, the pair of second convex portions 66B and the pair of hook portions 66C provided on the coupling member 65 side surface of the base portion 66A, and the photosensitive drum 47A side of the base portion 66A. And a pair of third convex portions 66D provided on the surface.

  A long hole 66E along the first radial direction is formed at the center of the base 66A. As a result, even when the Oldham member 66 is eccentric in the first radial direction with respect to the coupling member 65, the drive force transmission member 64 is moved in the direction approaching the main body drive gear 62 side. Interference between the extended portion 62F of the gear 62 and the Oldham member 66 is prevented (see FIG. 6B).

  The pair of second convex portions 66B are provided so as to face each other in the first radial direction across the elongated hole 66E, and engage with the pair of second concave portions 65K of the coupling member 65 as described above. Each of the second protrusions 66B has a hemispherical tip, so that when the Oldham member 66 is attached to the coupling member 65, each second protrusion 66B is formed in each second recess 65K. Easy to enter.

  The pair of hook portions 66C are hook-shaped protrusions that extend toward the coupling member 65 and bend inward in the radial direction, and are provided so as to face each other in the second radial direction across the long hole 66E. The coupling member 65 is engaged with a pair of long holes 65L.

  The pair of third convex portions 66D are provided so as to face each other in the second radial direction with the long hole 66E interposed therebetween. On the other hand, on the end surface of the photosensitive drum 47A, four third recesses A1 are formed as long grooves along the radial direction at positions shifted by approximately 90 ° from each other so as to sandwich the rotation shaft of the photosensitive drum 47A. . As a result, the pair of third convex portions 66D can move in the second radial direction and engage in the rotational direction in a state where the pair of third concave portions A1 enter the pair of opposing third concave portions A1. It is possible. That is, in the present embodiment, the second connection portion is configured by the third convex portion 66D and the third concave portion A1.

  The third convex portion 66D has a hemispherical tip. Thereby, the 3rd convex part 66D becomes easy to enter 3rd recessed part A1.

  In addition, the apparatus main body 2 has a detaching mechanism 70 for detaching the driving force transmitting member 64 from the photosensitive drum 47A by pushing the driving force transmitting member 64 (specifically, the coupling member 65) toward the main body driving gear 62. Is provided. 5A, the detachment mechanism 70 includes four cams 71, a support arm 72 that supports each cam 71, and a connection arm 73 that connects the support arm 72 and the front cover 21. It has. In FIG. 5, for convenience, the cam 71 is indicated by dot hatching.

  As shown in FIG. 3, the cam 71 has an inclined surface 71A that inclines to the left as it goes rearward. The inclined surface 71A and the annular flange 65C of the coupling member 65 are in the front-rear direction (perpendicular to the rotation axis direction). In the direction of contact).

  Then, as shown in FIGS. 5A and 5B, when the user opens the front cover 21, the connecting arm 73 and the support arm 72 are pulled forward in conjunction with the opening operation of the front cover 21. The cam 71 moves forward. 6A and 6B, the annular flange 65C of the coupling member 65 is pushed against the urging force of the coil spring 63 by the inclined surface 71A of the cam 71, and the driving force transmitting member 64 is detached from the photosensitive drum 47A, and the drawer 45 can be pulled out.

  Further, when the drawer 45 is mounted on the apparatus main body 2 by moving the drawer 45 from the above-described removal position to the storage position, each photosensitive drum 47A supported by the drawer 45 positioned at the storage position is connected to each driving force transmission member 64 in the axial direction. Opposite. In this state, as shown in the order of FIGS. 5B and 5A, when the front cover 21 is closed, the driving force transmission members 64 that are restrained by the cams 71 are changed to FIGS. As shown in the order of a), the coil spring 63 is moved to the right by the urging force of the coil spring 63 and connected to each photosensitive drum 47A.

  At this time, even if the central axis of the photosensitive drum 47A and the central axis of the main body driving gear 62 are shifted, the Oldham member 66 is engaged in the rotational direction with the photosensitive drum 47A and the coupling member 65 in the first radial direction. In addition, since it is movable in the second radial direction perpendicular to this, the Oldham member 66 transmits power while sliding with respect to the photosensitive drum 47A and the main body drive gear 62 as if it were an Oldham joint. Therefore, it is possible to satisfactorily transmit the driving force from the main body driving gear 62 to the photosensitive drum 47A through the driving force transmitting member 64.

  When the front cover 21 is closed with the drawer 45 removed from the apparatus main body 2, the driving force transmitting member 64 is not supported by the end surface of the photosensitive drum 47A, and thus the main body is located more than the position shown in FIG. It moves to a position away from the drive gear 62 by the pressing force of the coil spring 63 and is pressed by the support arm 72. At this time, depending on the arrangement of the support arm 72, the coupling member 65 may be separated from the main body drive gear 62 to a position where the hole 65 </ b> G of the coupling member 65 is likely to come off from the extending portion 62 </ b> F of the main body drive gear 62. However, even in this case, as described above, when the tapered surface 65H is formed in the hole portion 65G, the coupling member 65 is then pushed by the cam 71 according to the opening of the front cover 21, The hole 65G can be satisfactorily inserted into the extended portion 62F by the tapered surface 65H.

In the present embodiment, the following effects can be obtained in addition to the effects described above.
Even if the driving force transmission member is composed of one part and the groove for enabling the driving force transmission member to move in the axial direction is formed deeply, the driving force transmission member is moved in the axial direction and the first radial direction with respect to the main body driving gear. However, in this case, the movement in the axial direction becomes unstable, and there is a possibility that the driving force transmission member is not well connected to the photosensitive drum. On the other hand, in the present embodiment, the driving force transmission member 64 is divided into two parts, the coupling member 65 has a function of moving in the axial direction, and the function of moving in the first radial direction is provided by the Oldham member 66. Therefore, the driving force transmission member 64 can be stably moved in the axial direction, and the driving force transmission member 64 can be reliably connected to the photosensitive drum 47A.

  By providing the first concave portion 62C and the first convex portion 65D on the outer peripheral surface of the protruding portion 62B of the main body drive gear 62 and the inner peripheral surface of the cylindrical portion 65A of the coupling member 65, the first concave portion 62C and the first convex portion are provided. Since 65D can be covered with the cylindrical portion 65A, it is possible to suppress the accumulation of dust between the first concave portion 62C and the first convex portion 65D and the deterioration of the slidability.

  Since both end portions in the axial direction of the coupling member 65 (the end portion of the cylindrical portion 65A and the hole portion 65G) are supported by the protruding portion 62B and the extending portion 62F of the main body drive gear 62, the coupling member 65 is more stable. Can be moved in the axial direction.

  Since the first concave portion 62C is formed on the outer peripheral surface of the protruding portion 62B of the main body driving gear 62 and the first convex portion 65D is formed on the inner peripheral surface of the cylindrical portion 65A of the coupling member 65, the protruding portion is opposite to this. Compared to a structure in which a convex portion is formed on the outer peripheral surface of the ridge and a concave portion is formed on the inner peripheral surface of the cylindrical portion, the root portion of the convex portion can be positioned radially outward. Here, since the force applied to the root portion of the convex portion is calculated by torque / radius, the force applied to the root portion becomes smaller as the root portion of the convex portion is positioned on the radially outer side. Therefore, in the embodiment, since the force applied to the root portion of the first convex portion 65D can be reduced compared to the reverse structure as described above, the first convex portion 65D is not easily deformed, and the two parts The accuracy of the engaging portion can be maintained, and a constant driving force can always be transmitted. Moreover, it can also suppress that the 1st convex part 65D breaks because the force concerning the base part of 1st convex part 65D becomes small.

  Since the coil spring 63 that urges the driving force transmission member 64 (coupling member 65) away from the main body driving gear 62 is provided, the cam 71 that pushes the driving force transmission member 64 toward the main body driving gear 62 is pressed. The driving force transmitting member 64 can be advanced and retracted with respect to the photosensitive drum 47A simply by providing it on the surface. That is, it is not necessary to separately provide a mechanism for separating the driving force transmission member 64 from the main body driving gear 62 in the apparatus main body 2, so that the apparatus can be simplified.

  The locking rib 62E provided on the main body driving gear 62 and the locking claw 65E provided on the coupling member 65 restrict the movement of the coupling member 65 toward the photosensitive drum 47A. It is possible to prevent the coupling member 65 from being detached from the main body drive gear 62 by the urging force 63.

  The locking claw 65E is formed at a position farther from the surface of the concave portion (engagement concave portion 62D) than the first convex portion 65D, so that the locking claw 65E is brought into contact with the engagement concave portion 62D before being locked. Since the first convex portion 65D not configured as 65E contacts the first concave portion 62C, it is possible to prevent the locking claw 65E from contacting the engaging concave portion 62D and breaking.

In addition, this invention is not limited to the said embodiment, It can utilize with various forms so that it may illustrate below.
In the above-described embodiment, the photosensitive drum 47A is employed as the passive member. However, the present invention is not limited to this, and may be, for example, a developing roller. However, when a photosensitive member is employed as the passive member, even if the axis is shifted, a plurality of photosensitive members can always be rotated at a constant rotational speed, so that color misregistration and the like can be prevented.

  In the above-described embodiment, the drawer 45 is used as the moving member. However, the present invention is not limited to this. For example, when a plurality of process cartridges are detachable from the apparatus main body, the process cartridges are moved. You may employ | adopt as a member.

  In the above embodiment, the coupling member 65 is pushed by the detachment mechanism 70, but the present invention is not limited to this, and the Oldham member may be pushed. In this case, for example, a flange portion that extends radially outward may be formed on the Oldham member, and the flange portion may be pushed by a cam.

  In the above-described embodiment, the pair of third convex portions 66D of the Oldham member 66 has a cylindrical shape with rounded tips, but the present invention is not limited to this, and the pair of third convex portions are formed in different shapes. A third concave portion having a shape corresponding to the end portion of the photosensitive drum may be formed. According to this, since the photosensitive drum and the Oldham member can always be engaged in the same direction (same phase) in the rotation direction, the phases of the plurality of photosensitive drums can be always aligned even if the drawer is attached or detached. . Since the photosensitive drum and the Oldham member are always engaged in the same direction in this way, the accuracy of the photosensitive drum shake and the driving force transmission member can be always matched (a certain relationship can be achieved). Therefore, accurate print control can be easily performed, and high image quality can be achieved.

  In the above-described embodiment, the main body driving gear 62 is used as the main body driving member. However, the present invention is not limited to this. For example, a roller that wraps around the belt and transmits the driving force from the belt may be used. Good.

  The unevenness relationship in the embodiment may be reversed. That is, for example, a concave portion may be provided in the Oldham member, and a convex portion that engages with the concave portion may be provided in the passive member (photosensitive drum 47A). In contrast to the above-described embodiment, the main body driving member may be provided with a cylindrical portion, and the driving force transmitting member may be provided with a protruding portion.

In the above embodiment, the cam 71 is moved in the front-rear direction, but the present invention is not limited to this. For example, the driving force transmission member may be pushed in the axial direction by moving the cam in the up-down direction.
In the above-described embodiment, the coil spring 63 is employed as the biasing member. However, the present invention is not limited to this, and for example, a wire spring or a disc spring may be employed.

  In the above embodiment, the locking portions (the locking ribs 62E and the locking claws 65E) are provided on both the main body driving member (main body driving gear 62) and the driving force transmission member (driving force transmission member 64). However, the engaging portion may be provided on at least one of the main body driving member and the driving force transmitting member. For example, only a hook-shaped locking portion that extends from the main body drive member so as to penetrate the center of the drive force transmission member and contacts the end surface of the drive force transmission member on the passive member side may be provided.

In the above-described embodiment, the present invention is applied to the color laser printer 1, but the present invention may be applied to other image forming apparatuses such as a copying machine and a multifunction machine.
In the embodiment, the photosensitive drum 47A is used as the photosensitive member. However, the present invention is not limited to this, and for example, a belt-shaped photosensitive member may be used.

DESCRIPTION OF SYMBOLS 1 Color laser printer 2 Apparatus main body 45 Drawer 47A Photosensitive drum 60 Driving force transmission mechanism 61 Drive source 62 Main body drive gear 62B Protrusion part 62C 1st recessed part 62D Engaging recessed part 62E Locking rib 62F Extension part 63 Coil spring 64 Driving force transmission member 65 coupling member 65A cylindrical portion 65B wall 65C annular flange 65D first convex portion 65E locking claw 65K second concave portion 66 Oldham member 66B second convex portion 66C hook portion 66D third convex portion 70 release mechanism 71 cam 71A inclined surface 72 Support arm 73 Connecting arm A1 Third recess

Claims (10)

The device body;
A movable member movable between a storage position in the apparatus main body and a disengagement position outside the apparatus main body,
A main body driving member that is rotatably provided in the apparatus main body and transmits a driving force from a driving source;
A passive member that is rotatably provided on the moving member and faces the main body driving member in the axial direction of the main body driving member when the moving member is located at the storage position;
Driving force transmission disposed between the main body driving member and the passive member, and transmitting driving force from the main body driving member to the passive member by engaging the main body driving member and the passive member in a rotational direction. A member, and
Since the driving force transmission member can move in the axial direction with respect to the main body driving member, connection / disconnection of the driving force transmission member and the passive member can be switched,
The driving force transmission member has a coupling member disposed on the main body driving member side, and an Oldham member disposed on the passive member side,
The coupling member is supported by the main body drive member so as to be movable in the axial direction, and is engaged in the rotational direction.
The Oldham member is attached to the coupling member so as to be movable in the axial direction integrally with the coupling member, and is configured to be able to engage with the coupling member and the passive member in the rotational direction. And
The first connecting portion, which is a portion where the coupling member and the Oldham member are engaged in the rotational direction, engages with each other in an uneven manner so as to be movable in a first radial direction orthogonal to the axial direction,
The second connecting portion, which is a portion where the Oldham member and the passive member are engaged in the rotational direction, can move in a second radial direction perpendicular to the axial direction and the first radial direction. An image forming apparatus characterized by being engaged by unevenness. One of the main body driving member and the coupling member is provided with a protruding portion that protrudes toward the other, and the other is provided with a cylindrical portion into which the protruding portion enters,
2. The unevenness that is relatively movable in the axial direction and that engages in the rotation direction is formed on the outer peripheral surface of the protruding portion and the inner peripheral surface of the cylindrical portion. The image forming apparatus described. The main body driving member includes the protruding portion and an extending portion extending in the axial direction from the protruding portion,
The coupling member includes the cylindrical portion, a wall that closes an end portion of the cylindrical portion on the Oldham member side, and a hole that is formed in the wall and into which the extending portion enters. The image forming apparatus according to claim 2. A first recess along the axial direction is provided on the outer peripheral surface of the protrusion;
4. The image forming apparatus according to claim 2, wherein a first convex portion along the axial direction is provided on an inner peripheral surface of the cylindrical portion. 5. The first connection portion includes a second convex portion provided on one of the wall and the Oldham member, and a second concave portion provided on the other and engaged with the second convex portion,
The second connection portion is configured by a third convex portion provided on one of the Oldham member and the passive member, and a third concave portion provided on the other and engaged with the third convex portion. The image forming apparatus according to claim 4.   The detachment mechanism for detaching the driving force transmission member from the passive member by pushing the driving force transmission member toward the main body driving member is provided. The image forming apparatus described in the item. An opening formed in the apparatus main body for moving the moving member from the storage position to the disengagement position;
A cover for opening and closing the opening,
The detachment mechanism is
The cam has a cam that moves in a direction perpendicular to the axial direction in conjunction with the opening operation of the cover, and the cam is configured to push the driving force transmitting member toward the main body driving member. The image forming apparatus according to claim 6. A biasing member that biases the main body driving member and the coupling member in a direction away from each other is provided between the main body driving member and the coupling member,
The locking portion for restricting movement of the coupling member toward the passive member is provided on at least one of the main body driving member and the coupling member. 8. The image forming apparatus according to 7. Concavities and convexities formed on the outer peripheral surface of the protruding portion and the inner peripheral surface of the cylindrical portion are composed of a plurality of convex portions arranged apart from each other in the rotation direction and a plurality of concave portions into which the plurality of convex portions enter. ,
A part of the plurality of convex portions is configured as the locking portion,
When the cylindrical portion moves in the radial direction or the rotational direction relative to the protruding portion, before the locking portion comes into contact with the concave portion, a convex portion that is not configured as the locking portion is To contact the recess,
The image forming apparatus according to claim 8, wherein the locking portion is formed at a position farther from the surface of the concave portion than a convex portion that is not configured as the locking portion. The image forming apparatus according to claim 1, wherein the passive member is a photoconductor on which an electrostatic latent image is formed.

Images