JP5201285B2 - Process cartridge - Google Patents

Description

  The present invention relates to an image forming apparatus such as an electrophotographic printer and a process cartridge attached to the image forming apparatus.

2. Description of the Related Art An image forming apparatus such as an electrophotographic printer is known in which a process cartridge is detachably attached to an apparatus main body.
In this type of image forming apparatus, for example, cartridge mounting guide members are provided opposite to each other on the left and right sides of the cartridge mounting space in the apparatus main body. The process cartridge is provided with a photosensitive drum. The process cartridge is formed with bosses that protrude from both side surfaces of the photosensitive drum in the rotation axis direction. The process cartridge is inserted into the apparatus main body while the boss is guided by the cartridge mounting guide member, whereby the process cartridge is mounted on the apparatus main body.

A cartridge side coupling is provided on one side surface of the process cartridge. The cartridge side coupling is disposed inside a cylindrical portion protruding from one side surface of the process cartridge. When the process cartridge is attached to the apparatus main body, the main body side coupling provided in the apparatus main body is coupled to the cartridge side coupling, and the driving force is transmitted from the main body side coupling to the cartridge side coupling. The photosensitive drum is rotationally driven by this driving force (see, for example, Patent Document 1).
JP-A-8-262957

However, in the above-described image forming apparatus, when the process cartridge is mounted on the apparatus main body, the cylindrical portion that accommodates the cartridge side coupling is caught by a member disposed in the apparatus main body, and the mounting of the process cartridge is obstructed. There is a bug that is done.
An object of the present invention is to provide a process cartridge and an image forming apparatus including such a process cartridge, which can be smoothly attached to the apparatus main body.

In order to achieve the above object, the invention according to claim 1 is a process cartridge comprising a photosensitive drum rotatable about a rotation axis and a frame provided with the photosensitive drum , wherein the photosensitive drum is a cylinder. A drum body, a flange member fixed to an end of the drum body in the rotation axis direction, and a driving force for rotating the photosensitive drum provided on an end surface of the flange member in the rotation axis direction. a drum drive input unit inputted, wherein the frame has a front first protrusion protruding to expose an end face of Oite the flange member Kikai guinea-line direction, the first The projecting portion is arranged in front of the first portion so as to create a space for arranging a drum drive transmission member that transmits a driving force to the drum drive input portion in the rotation axis direction. It is characterized by having a smaller second portion of the projection amount than the first part.

According to the invention described in claim 1, such as when the process cartridge detachable with respect to instrumentation Okimoto body can drum drive input portion can be prevented from being damaged due to collision with other members.

1. 1 is a side sectional view showing an embodiment of a printer as an example of an image forming apparatus of the present invention.
The printer 1 is a tandem type color printer. In a main body casing 2 as an example of the apparatus main body, four process cartridges 3 are arranged in parallel corresponding to the respective colors of black, yellow, magenta, and cyan. Each process cartridge 3 can be attached to and detached from the main body casing 2 with the top cover 4 on the upper surface of the main body casing 2 being opened.

  Each process cartridge 3 includes a drum cartridge 7 that holds the photosensitive drum 5 and the scorotron charger 6, and a developing cartridge 9 that holds the developing roller 8 and is detachably attached to the drum cartridge 7. The surface of the photosensitive drum 5 is uniformly charged by the scorotron charger 6 and then selectively exposed by the LEDs provided in the LED unit 10. Thereby, an electrostatic latent image based on the image data is formed on the surface of each photosensitive drum 5. Each electrostatic latent image is visualized by toner carried on the developing roller 8, and a toner image is formed on the surface of the photosensitive drum 5.

  The paper P is accommodated in a paper feed cassette 11 disposed at the bottom of the main casing 2. The paper P stored in the paper feed cassette 11 is transported onto the transport belt 12 by various rollers. The conveyor belt 12 is disposed to face the four photosensitive drums 5 from below. The paper P transported on the transport belt 12 sequentially passes between the transport belt 12 and each photosensitive drum 5 as the transport belt 12 travels. The toner image on the surface of the photosensitive drum 5 is transferred onto the paper P by the transfer bias applied to the transfer roller 13 when facing the paper P. The transfer roller 13 is disposed to face each photosensitive drum 5 with the conveyance belt 12 interposed therebetween.

The sheet P on which the toner image is transferred is conveyed to the fixing unit 14. The toner image transferred onto the paper P is thermally fixed by the fixing unit 14. Thereafter, the paper P is discharged to the paper discharge tray 15 by various rollers.
In the case of distinguishing the process cartridge 3 from a specific color from other colors, K (black), Y (yellow), M (magenta), and C representing each color at the end of the reference numerals thereof. Add (cyan).

Further, the upstream side in the conveyance direction of the paper P by the conveyance belt 12 is the front side in the printer 1, and the time when the printer 1 is viewed from the front side is the left and right reference in the printer 1. With respect to the process cartridge 3, the side where the developing cartridge 9 is disposed with respect to the photosensitive drum 5 in the state of being placed in the horizontal direction is the front side, and the time when the process cartridge 3 is viewed from the front side is the upper, lower, left and right reference There is a case. Each figure includes arrows indicating front, rear, up, down, left and right directions.
2. Process Cartridge FIG. 2 is a perspective view of the process cartridge from the right front direction. FIG. 3 is a left side view of the process cartridge. FIG. 4 is a plan view of the process cartridge. FIG. 5 is a perspective view of the drum cartridge from the right front direction.
(1) Drum Cartridge As shown in FIG. 5, the drum cartridge 7 includes a drum frame 21 as an example of a frame. The drum frame 21 integrally includes a pair of drum side walls 22 and 23, a drum rear wall 24, a drum upper wall 25, and a drum front wall 26.

The pair of drum side walls 22 and 23 are opposed to each other with an interval in the left-right direction.
As shown in FIG. 3, the left drum side wall 22 includes a left side wall rear portion 27, a left side wall middle portion 28, and a left side wall front portion 29.
The left side wall rear portion 27 is formed in a substantially triangular shape in a side view. A substantially cylindrical protective portion 30 is formed on the left side wall rear portion 27 so as to protrude outward (leftward). As shown in FIG. 4, in the protection unit 30, the rear portion 31 as an example of the downstream portion protrudes with a protrusion amount smaller than the protrusion amount of the front portion 32 as an example of the upstream portion. And the end surface of the front side part 32 and the end surface of the rear side part 31 are connected by the inclined surface which inclines so that it may approach the left side wall rear part 27 so that it may become back. Further, a through hole is formed in the left wall rear portion 27 in a portion surrounded by the protection portion 30, and a drum left bearing 33 is fitted into the through hole as shown in FIG.

  The left side wall middle portion 28 is formed in a substantially rectangular shape in side view with a smaller height than the left side wall rear portion 27, and extends forward from the lower front end of the left side wall rear portion 27 as shown in FIG. It bends outward and bends and extends forward. An opening is formed in the left wall middle portion 28 in a bent portion 34 bent outward in the middle portion, and a portion on the rear side of the bent portion 34 from the opening is cut out in a substantially U shape in a side view. Thus, a mounting guide groove 35 is formed. As shown in FIG. 3, the plane including the upper surface of the mounting guide groove 35 passes through the rotation center of the developing passive gear 61 described later in a state where the developing cartridge 9 is mounted on the drum cartridge 7. Further, a long hole 36 having a diameter in the front-rear direction slightly longer than the diameter in the vertical direction is formed in the middle portion 28 on the left side wall in a portion on the front side of the bent portion 34.

The left side wall front portion 29 is formed to extend obliquely upward from the front end edge of the left side wall middle portion 28 toward the front.
As shown in FIG. 5, the right drum side wall 23 includes a right side wall rear portion 37, a right side wall middle portion 38, and a right side wall front portion 39.
The right side wall rear portion 37 is formed in a substantially triangular shape in a side view and faces the left side wall rear portion 27 in the left-right direction. A drum right bearing 40 is attached to the rear portion 37 of the right wall.

  The right side wall middle portion 38 is formed in a substantially rectangular shape in side view having a smaller height than the right side wall rear portion 37, and extends forward from the lower front end of the right side wall rear portion 37 as shown in FIG. It bends outward and bends and extends forward. An opening is formed in the right side wall middle portion 38 at a bent portion 41 bent outward in the middle, and a portion rearward of the bent portion 41 from the opening is cut out in a substantially U shape in a side view. Thus, a mounting guide groove 42 is formed. The mounting guide groove 42 faces the mounting guide groove 35 in the left side wall middle portion 28 in the left-right direction, and the upper surface of the mounting guide groove 42 is located on the same plane as the upper surface of the mounting guide groove 35.

The right side wall front portion 39 is formed to extend obliquely upward from the front end edge of the right side wall middle portion 38 toward the front.
The photosensitive drum 5 is held by the left side wall rear portion 27 of the drum side wall 22 and the right side wall rear portion 37 of the drum side wall 23. The photosensitive drum 5 includes a cylindrical drum main body 44 and a drum shaft 45 extending along the central axis of the drum main body 44. A flange member 46 (the right flange member 46 is not shown) is fixed to both ends of the drum main body 44, and a drum shaft 45 is inserted into the center of each flange member 46 so as to be relatively rotatable. Yes. The right end portion of the drum shaft 45 is inserted into the drum right bearing 40 so as not to rotate relative to the drum shaft 45, and protrudes to the right from the drum right bearing 40. On the other hand, the flange member 46 fixed to the left end portion of the drum main body 44 is held by the drum left bearing 33 so as to be relatively rotatable. Thus, the drum main body 44 of the photosensitive drum 5 is provided between the left side wall rear portion 27 and the right side wall rear portion 37 so as to be rotatable about the drum shaft 45.

Further, the end face of the left flange member 46 is exposed at a portion surrounded by the protection part 30. And the connection member 47 as a drum drive input part is attached to the end surface of the exposed flange member 46 (refer FIG. 3).
The drum rear wall 24 is provided between the rear end portion of the drum side wall 22 and the rear end portion of the drum side wall 23.

The drum upper wall 25 is constructed between the upper end portion of the left side wall rear portion 27 of the drum side wall 22 and the upper end portion of the right side wall rear portion 37 of the drum side wall 23.
The drum front wall 26 is constructed between the lower end portion of the left side wall front portion 29 of the drum side wall 22 and the lower end portion of the right side wall front portion 39 of the drum side wall 23 and is formed so as to be inclined obliquely upward as it goes forward. Has been. On the drum front wall 26, pressing levers 48 for pressing the developing cartridge 9 toward the photosensitive drum 5 are provided at two positions across the center in the left-right direction.
(2) Developer Cartridge As shown in FIGS. 2 to 4, the developer cartridge 9 is attached to the drum cartridge 7, and the left side wall middle portion 28 and the left side wall front portion 29 of the drum side wall 22, and the right side of the drum side wall 23. It is disposed between the middle wall portion 38 and the right side wall front portion 39.

The developing cartridge 9 includes a housing 51. The casing 51 is formed in a box shape whose rear side is opened. As shown in FIG. 1, the housing 51 holds the developing roller 8, the supply roller 52, the layer thickness regulating blade 53, and the agitator 54. The housing 51 contains toner.
As shown in FIG. 4, the developing roller 8 is disposed so as to be exposed rearward from the housing 51, and is rotatably supported on both side walls 55 and 56 of the housing 51. Specifically, as shown in FIGS. 2 and 3, substantially cylindrical developing bearing members 57 and 58 projecting outward are provided at the rear ends of the side walls 55 and 56, respectively. The developing bearing members 57 and 58 are disposed at positions facing each other in the left-right direction. As shown in FIG. 4, the developing roller 8 has a configuration in which a metallic developing roller shaft 59 is covered with a rubber roller 60 made of conductive rubber. The developing roller 8 is rotatably supported on both side walls 55 and 56 by both ends of the developing roller shaft 59 being rotatably inserted into the developing bearing members 57 and 58.

Further, as shown in FIG. 3, a developing passive gear 61 to which a driving force such as the developing roller 8 is input is provided on the left side wall 55 of the casing 51, behind the developing bearing member 57. The developing passive gear 61 faces the long hole 36 formed in the drum side wall 22 of the drum cartridge 7 in a state where the developing cartridge 9 is mounted on the drum cartridge 7. The developing passive gear 61 receives a rotational force in the clockwise direction in FIG.
(3) Mounting of developing cartridge on drum cartridge The developing cartridge 9 is mounted on the drum cartridge 7 from the front of the photosensitive drum 5. When mounting, first, developing bearing members 57 and 58 projecting from the housing 51 of the developing cartridge 9 to the left and right sides are fitted into the mounting guide grooves 35 and 42, respectively. When the developing cartridge 9 is pushed rearward, the developing cartridge 9 moves rearward while the developing bearing members 57 and 58 are guided by the mounting guide grooves 35 and 42, respectively. During this movement, the housing 51 of the developing cartridge 9 comes into contact with the pressing lever 48 and the housing 51 is pushed downward against the pressing force of the pressing lever 48, so that the developing cartridge 9 with respect to the drum cartridge 7 is pressed. Installation is complete. In this state, in the developing cartridge 9, the developing roller 8 is pressed against the photosensitive drum 5 by the pressing force (biasing force) of the pressing lever 48. Note that when the mounting is completed, there is a gap between the developing bearing members 57 and 58 and the rear ends of the guide grooves 35 and 42.
3. Main Body Frame FIG. 6 is a perspective view from the front right direction in the main body casing.

  In the main casing 2, a pair of main body frames 62 and 63 are arranged to face each other with a space in the left-right direction. Each of the main body frames 62 and 63 is made of a sheet metal and is formed in a substantially rectangular shape in a side view. The black process cartridge 3K, the yellow process cartridge 3Y, the magenta process cartridge 3M, and the cyan process cartridge 3C are mounted between the main body frames 62 and 63 in this order from the front side.

The main body frames 62 and 63 are connected via four round bar-like connecting members 64, 65, 66 and 67. The connecting member 64 is installed between the upper ends of the main body frames 62 and 63 in front of the black process cartridge 3K. The connecting member 65 is provided between the lower ends of the main body frames 62 and 63 below the black process cartridge 3K. The connecting member 66 is installed between the upper ends of the main body frames 62 and 63 in front of the cyan process cartridge 3C. The connecting member 67 is installed between the lower ends of the main body frames 62 and 63 in front of the cyan process cartridge 3C. Thus, the main body frames 62 and 63 and the four connecting members 64 to 67 constitute a robust structure that does not cause distortion when the process cartridge 3 is attached or detached.
(1) Left Main Body Frame FIG. 7 is a left side view of the left main body frame.

  The left main body frame 62 has process guide grooves 71 as an example of four guide portions. The process guide groove 71 is formed by cutting out the main body frame 62 from the upper end edge thereof, has a width corresponding to the outer diameter of the protection part 30 formed in the drum frame 21, and extends from the upper end edge of the main body frame 62 to the process guide groove 71. It extends diagonally downward and rearward to the center in the vertical direction. At the lower end of the process guide groove 71, a first abutting portion 72 having a rectangular shape in side view protruding upward in the process guide groove 71, and a side view in general protruding in the process guide groove 71 forward. A rectangular second contact portion 73 is formed. The four process guide grooves 71 are formed at equal intervals in the front-rear direction.

Further, the main body frame 62 is provided with a columnar protrusion 74 protruding leftward at each position spaced diagonally downward and forward from the lower end of each process guide groove 71.
Further, guide holes 75 penetrating the main body frame 62 are formed in the main body frame 62 at positions spaced slightly forward and obliquely downward with respect to the protrusions 74. The guide hole 75 has a straight hole portion 76 extending in the front-rear direction and a cross hole portion 77 extending obliquely downward and rearward from the rear end of the straight hole portion 76. In the foremost guide hole 75 among the four guide holes 75, the straight hole portion 76 is formed longer than the straight hole portions 76 of the other guide holes 75.

In addition, an arc-shaped hole 187 centering on each protrusion 74 passes through the main body frame 62 at a position in front of each process guide groove 71 and spaced diagonally above and forward of each protrusion 74. Is formed.
(2) Right Body Frame As shown in FIG. 6, the right body frame 63 has 4 at each position facing the four process guide grooves 71 formed in the left body frame 62 in the left-right direction. A guide groove 78 as an example of two guide portions is formed. The guide groove 78 is formed by notching from the upper end edge of the main body frame 63, extends obliquely downward and rearward from the upper end edge of the main body frame 63 to the center in the vertical direction, and narrows downward.

Further, the main body frame 63 is provided with a columnar protruding portion 79 protruding rightward at each position spaced diagonally downward and forward with respect to the lower end portion of each guide groove 78.
Further, guide holes 80 that penetrate the main body frame 63 are formed in the main body frame 63 at positions that are spaced slightly forward and obliquely downward with respect to the protrusions 79. The guide hole 80 has a straight hole portion 81 extending in the front-rear direction and a cross hole portion 82 (see FIG. 23) extending obliquely downward and rearward from the rear end of the straight hole portion 81. In the foremost guide hole 80 among the four guide holes 80, the straight hole portion 81 is formed longer than the straight hole portions 81 of the other guide holes 80.
4). Configuration for Transmission of Driving Force to Process Cartridge FIG. 8 is a perspective view from the front left direction of the driving force transmission mechanism and the first cover interlocking mechanism. FIG. 9 is a left side view of the driving force transmission mechanism and the first cover interlocking mechanism, showing a state where the top cover is closed. FIG. 10 is a perspective view from the front right direction of the driving force transmission mechanism and the first cover interlocking mechanism, and shows a state where the top cover is closed. FIG. 11 is a plan view of the driving force transmission mechanism, showing a state in which the top cover is closed. FIG. 12 is a left side view of the driving force transmission mechanism and the first cover interlocking mechanism, showing a state where the top cover is opened. FIG. 13 is a perspective view from the front right direction of the driving force transmission mechanism and the first cover interlocking mechanism, and shows a state in which the top cover is opened. FIG. 14 is a plan view of the driving force transmission mechanism, showing a state in which the top cover is opened.

8 to 14 show a fixed / contact / separation linear motion cam 153 and a contact / separation drive mechanism 211 which will be described later. Further, FIG. 8 shows the process cartridge 3 and the top cover 4.
(1) Driving force transmission member A driving force transmission mechanism 91 for transmitting the driving force to the process cartridge 3 is provided outside the left main frame 62 (see FIG. 6). In FIG. 8, the main body frame 62 is disposed between the four process cartridges 3 and the driving force transmission mechanism 91, but the main body frame 62 is not shown for simplification of the drawing.

As shown in FIG. 10, the drive force transmission mechanism 91 includes four drum drive transmission members 92, four development drive transmission members 93, and a driving linear cam 94.
(1-1) Drum Drive Transmission Member Four drum drive transmission members 92 are provided corresponding to the four process cartridges 3. The drum drive transmission member 92 is a connecting member provided on the photosensitive drum 5 of the process cartridge 3 when the corresponding process cartridge 3 is in contact with a blocking member 191 (described later). 47 (see FIG. 3).

15A and 15B are cross-sectional views of the drum drive transmission member.
The drum drive transmission member 92 is integrally provided with a gear portion 95 and a convex portion 96 protruding rightward from the center portion of the gear portion 95.
The gear part 95 is formed in a substantially annular plate shape. A large number of gear teeth to which driving force from a drum motor (not shown) is input are formed on the outer peripheral surface of the gear portion 95.

  The convex portion 96 has a cylindrical proximal end outer peripheral surface 97 having a common center axis with the gear portion 95. The convex portion 96 has a cylindrical distal end side outer peripheral surface 98 having a central axis common to the gear portion 95 on the right side of the proximal end outer peripheral surface 97. The distal end side outer peripheral surface 98 is formed to have a smaller diameter than the proximal end side outer peripheral surface 97. Further, the convex portion 96 is connected to an annular step surface 99 connected to the distal end edge of the proximal end outer peripheral surface 97 and the proximal end edge of the distal end outer peripheral surface 98, and the distal end edge of the distal end outer peripheral surface 98. And an annular tip surface 100. The front end surface 100 is formed with a linear engagement groove 101 (see FIG. 10) that can be engaged with a connecting member 47 (see FIG. 16) attached to the end surface of the flange member 46. Further, the convex portion 96 is integrally provided with a cylindrical portion 102 that extends toward the left from the opening peripheral edge portion of the distal end surface 100.

  A holder 103 is attached to the outer surface of the main body frame 62 so as to cover the driving force transmission mechanism 92. The holder 103 is provided with a support shaft 104 so as to extend to the right corresponding to each drum drive transmission member 92. When the support shaft 104 is inserted into the cylindrical portion 102 so as to be rotatable and slidable in the left-right direction, the drum drive transmission member 92 is supported rotatably about the support shaft 104 and is shown in FIG. 15A. Between the advanced position and the retracted position shown in FIG. Further, as shown in FIG. 8, one end of a coil spring 105 provided so as to wind around the cylindrical portion 102 is fixed to the drum drive transmission member 92. The other end of the coil spring 105 is fixed to the holder 103 (see FIG. 15A). Due to the biasing force (elastic force) of the coil spring 105, the drum drive transmission member 92 is always biased in the right direction.

FIG. 16 is a perspective view of the drum body, the flange member, the connecting member, and the drum drive transmission member. FIG. 17A is a right side view of the drum drive transmission member. FIG. 17B is a left side view of the connecting member. FIG. 17C is a left side view of the flange member.
As shown in FIGS. 16 and 17A, the engagement groove 101 is formed on a straight line passing through the center of the front end surface 100 of the drum drive transmission member 92.

  As shown in FIGS. 16 and 17B, the connecting member 47 has a flat cylindrical main body portion 106, two one-side protrusions 107 projecting from one end surface of the main body portion 106, and the other end surface of the main body portion 106. Two protruding protrusions 108 are integrally provided. The one side protrusion 107 is disposed at two positions that are point-symmetric (180-degree rotational symmetry) with respect to the center of the main body portion 106. The other projection 108 is point-symmetrical (180-degree rotational symmetry) with respect to the center of the main body 106, and is disposed at two positions that are shifted by 90 degrees around the center of the main body 106 with respect to the one projection 107. Has been.

  As shown in FIG. 17C, a substantially cylindrical drum-side engagement portion 109 that protrudes to the left is formed on the end surface of the flange member 46. On the end face of the drum side engaging portion 109, concave portions 110 are formed at two positions that are point-symmetric (180-degree rotational symmetry) with respect to the center of the drum side engaging portion 109 (flange member 46). The drum-side engaging portion 109 (the end surface of the flange member 46) is fitted with the other protrusion 108 of the connecting member 47 in each recess 110, so that the connecting member 47 is positioned in the direction opposite to the other protrusion 108. It is coupled so that it can be displaced.

In a state where the drum drive transmission member 92 has advanced to the advance position shown in FIG. 15, each one-side protrusion 107 of the coupling member 47 fits into the engagement groove 101 of the drum drive transmission member 92. Thereby, the connecting member 47, the drum drive transmission member 92, and the drum side engaging portion 109 constitute a so-called Oldham coupling. Therefore, even when the rotation center of the drum drive transmission member 92 and the rotation center of the flange member 46 (photosensitive drum 5) are slightly deviated, the deviation is allowed and the rotation of the drum drive transmission member 92 is good for the flange member 46. Is transmitted to.
(1-2) Development Drive Transmission Member Four development drive transmission members 93 are provided corresponding to each process cartridge 3 as shown in FIG. The development drive transmission members 93 are developed in the process cartridge 3 (developing cartridge 9) when the corresponding process cartridge 3 is in contact with a blocking member 191 (described later). It arrange | positions in the position facing the passive gear 61 (refer FIG. 3).

18A and 18B are cross-sectional views of the development drive transmission member.
The development drive transmission member 93 includes a development drive gear 111, an advance / retreat member 112, and a coil spring 113, as shown in FIGS. 10, 18A and 18B.
The development drive gear 111 integrally includes a substantially disc-shaped gear body 114 and a substantially cylindrical guide core portion 115 projecting rightward from the gear body 114.

A large number of gear teeth to which a driving force from a developing motor (not shown) is input are formed on the outer peripheral surface of the gear body 114.
As shown in FIGS. 18A and 18B, the guide core portion 115 is formed so that its central axis coincides with the central axis of the gear body 114. The guide core portion 115 has a distal end core portion 116 having a relatively small first outer diameter at the distal end portion, and a proximal end core portion having a relatively large second outer diameter at the proximal end portion. 117. The outer peripheral surface of the distal end core portion 116 and the outer peripheral surface of the proximal end core portion 117 are continuous without a step due to the inclined surface.

  The advancing / retracting member 112 is provided adjacent to the left end of the cylindrical end tube portion 118 having a relatively small first inner diameter, and a cylindrical shape having a relatively large second inner diameter. The base end cylinder part 119, the engaging part 120 provided adjacent to the right side of the front end cylinder part 118, and the flange part 121 projecting from the outer peripheral surface of the front end cylinder part 118 to the periphery are integrally provided. The first inner diameter is substantially the same as or slightly larger than the first outer diameter of the tip deep portion 113. The second inner diameter is substantially the same as or slightly larger than the second outer diameter of the proximal end core portion 117. A guide core 115 is inserted into the advance / retreat member 112 from the left. The advancing / retracting member 112 is movable in the left-right direction with respect to the guide core portion 115, and can be moved back and forth between the advanced position shown in FIG. 18A and the retracted position shown in FIG.

The coil spring 113 is provided so as to wind around the guide core portion 115 and is interposed between the advance / retreat member 112 and the gear main body 114. The advance / retreat member 112 is always urged rightward by the urging force (elastic force) of the coil spring 113.
The holder 103 is provided with a support shaft 128 corresponding to each development drive transmission member 93 so as to extend rightward. By inserting the support shaft 128 into the guide core member 115 so as to be rotatable and non-slidable, the developing drive gear 111 is supported so as to be rotatable and non-slidable about the support shaft 128.

FIG. 19A is a right side view of the advance / retreat member.
The engaging part 120 of the advancing / retracting member 112 is integrally provided with a substantially cylindrical center part 122 extending in the left-right direction and two abutting protrusions 123 connected to the peripheral surface of the center part 122. The two abutting protrusions 123 are arranged on a straight line passing through the center of the central portion 122 and are formed in a shape that is rotationally symmetric with respect to the center of the central portion 122 by 180 degrees.

FIG. 19B is a left side view of the development passive gear.
On the outer end surface of the development passive gear 61, a circular recess 124 having a diameter substantially the same as the outer diameter of the center portion 122 of the engaging portion 120 is formed. Further, two contacted portions 125 are provided around the concave portion 124 on the outer end surface of the development passive gear 61. Each contacted portion 125 is formed in a substantially L shape in a side view having a short piece portion 126 and a long piece portion 127 orthogonal thereto. The short side portion 126 of each contacted portion 125 extends on a straight line passing through the center of the recessed portion 124. The long piece portion 127 of each contacted portion 125 extends along the straight line at a distance from a straight line that passes through the center of the recess 124 and is perpendicular to the straight line that passes through the two short side portions 126. . The two contacted portions 125 are 180 degrees rotationally symmetric with respect to the center of the recess 124.

  In the state where the advancing / retracting member 112 has advanced to the advance position shown in FIG. 18A, the stop portion 122 of the engaging portion 120 fits into the recess 124 of the developing passive gear 61, and each abutting protrusion 123 of the engaging portion 120 is the developing passive gear. 61 abuts in the circumferential direction of the developing passive gear 61 with respect to the long piece portion 127 of each contacted portion 125. Therefore, in this state, when a rotational force is input to the development drive gear 111 and the advance / retreat member 112 is rotated together with the development drive gear 111, the rotational force is transmitted from each contact projection 123 to each contacted portion 125. Then, the developing passive gear 61 rotates in the same direction as the advance / retreat member 112.

Then, the distal end core portion 116 and the proximal end core portion 117 of the guide core portion 115 and the distal end cylindrical portion 118 and the proximal end cylindrical portion 119 of the advance / retreat member 112 have the following three conditions (1). And (2).
Condition (1): The advancing / retreating member 112 is between the retracted position shown in FIG. 18B and the position where a part of each abutting protrusion 123 of the advancing / retracting member 112 abuts on each abutted portion 125 of the development passive gear 61. In the positioned state, the distal end core portion 116 of the guide core portion 115 is disposed in the distal end cylindrical portion 118 of the advance / retreat member 112, and the proximal end of the guide core portion 115 is disposed in the proximal end cylindrical portion 119 of the advance / retreat member 112. A core part 117 is arranged.

Condition (2): In a state where the advance / retreat member 112 has advanced to the advance position shown in FIG. 18A, the base end core portion 117 of the guide core portion 115 is removed from the base end cylindrical portion 119 of the advance / retreat member 112, and the base of the advance / retreat member 112 is reached. A distal end core portion 116 of the guide core portion 115 is disposed in the end tube portion 119.
Thereby, in the state where the advance / retreat member 112 has advanced to the advance position, the play in the radial direction of the advance / retreat member 112 with respect to the guide core portion 115 increases. Therefore, even if the rotation center of the development passive gear 61 and the rotation center of the development drive transmission member 93 (development drive gear 111) are deviated, the deviation amount is within the range of play in the radial direction of the advance / retreat member 112 with respect to the guide core portion 115. If this is the case, the deviation is allowed, and the rotational force is favorably transmitted from the development drive transmission member 93 to the development passive gear 61.
(1-3) Driving linear motion cam The driving linear motion cam 94 is a member extending long in the front-rear direction as shown in FIGS. 10, 11, 13 and 14, and is attached to the main body frame 62 (see FIG. 6). It is attached so that it can reciprocate linearly back and forth. As shown in FIGS. 11 and 14, the driving linear cam 94 includes a rectangular plate-like main body 131 elongated in the front-rear direction, four first cam portions 132 formed integrally with the main body 131, and a main body. And four second cam portions 133 formed integrally with the portion 131.

  The main body 131 is provided in parallel with the main body frame 62. Four insertion holes 134 are formed in the main body 131. The insertion / extraction holes 134 are formed at positions facing the four development drive transmission members 93 in the left-right direction. Each insertion / extraction hole 134 is formed in the shape of a long hole extending in the front-rear direction, and has a dimension that allows the advance / retreat member 112 of the development drive transmission member 93 to be inserted / removed in the vertical direction. As shown in FIG. 10, the development drive transmission member 93 faces the rear end of each insertion / extraction hole 134 in a state where the drive linear cam 94 is disposed at a relatively forward position. On the other hand, as shown in FIG. 13, the development drive transmission member 93 faces the front end portion of each insertion / extraction hole 134 in a state where the drive linear cam 94 is disposed at a relatively rear position.

  The first cam portion 132 is provided on the left side surface of the main body portion 131 (the surface opposite to the surface facing the main body frame 62) corresponding to each insertion / extraction hole 134. The first cam portion 132 is formed in a substantially U shape in a side view along a substantially half circumference on the front side at the periphery of the insertion / extraction hole 134. Further, as shown in FIG. 14, the first cam portion 132 includes an inclined portion 135 that is inclined so as to be separated from the main body portion 131 toward the front, and a flat portion 136 that is parallel to the main body portion 131 from the front end of the inclined portion 135. And is formed in a substantially trapezoidal shape in plan view.

  The second cam portion 133 is provided at the lower end portion of the left side surface of the main body portion 131 corresponding to each drum drive transmission member 92. As shown in FIGS. 11 and 14, the second cam portion 133 is formed behind each first cam portion 132 so as not to overlap the first cam portion 132 in plan view. As shown in FIG. 14, the second cam portion 133 includes an inclined portion 137 that is inclined so as to be separated from the main body portion 131 toward the front, and a flat portion 138 that is parallel to the main body portion 131 from the front end of the inclined portion 137. And is formed in a substantially trapezoidal shape in plan view.

  10 and 11, the advance / retreat member 112 of each development drive transmission member 93 is inserted into the rear end portion of the insertion / extraction hole 134, and the flange 121 is located on the left side surface of the main body 131 of the drive linear cam 94. A part of the distal end cylindrical portion 118 and the engaging portion 120 protrude rightward with respect to the main body portion 131. Each first cam portion 132 is positioned in front of each development drive transmission member 93. In the drum drive transmission member 92, the stepped surface 99 abuts on the left side surface of the main body 131 of the driving linear cam 94, and the tip portion of the convex portion 96 (the portion where the tip end outer peripheral surface 98 is formed). Under the main body 131, the main body 131 protrudes to the right. Each second cam portion 132 is positioned forward with respect to each drum drive transmission member 92. In other words, both the drum drive transmission members 92 and the advance / retreat members 112 of the development drive transmission members 93 have advanced to the advanced positions.

  When the drive linear cam 94 is moved rearward from this state, the inclined portion 135 of each first cam portion 132 comes into contact with the flange portion 121 of each advance / retreat member 112, and the inclined portion of each second cam portion 133. 137 contacts the step surface 99 of each drum drive transmission member 92. When the driving linear cam 94 is further moved rearward, the respective advancing / retracting members 112 and the respective first cam portions are arranged such that the flange portions 121 of the respective advancing / retreating members 112 ride on the inclined portions 135 of the respective first cam portions 132. 132 moves relatively. Accordingly, each advance / retreat member 112 receives a leftward force from each first cam portion 132 and moves to the left against the biasing force of the coil spring 113. Also, each drum drive transmission member 92 and each second cam portion 133 move relatively so that the stepped surface 99 of each drum drive transmission member 92 rides on the inclined portion 137 of each second cam portion 133. Accordingly, each drum drive transmission member 92 receives a leftward force from each second cam portion 133 and moves to the left against the biasing force of the coil spring 105.

In the state shown in FIGS. 13 and 14, each of the advancing and retracting members 112 has the flange portion 121 abutted against the flat portion 136 of the first cam portion 132, and only the engaging portion 120 is inserted through the front end portion of the insertion / extraction hole 134. Yes. In each drum drive transmission member 92, the stepped surface 99 abuts against the flat portion 138 of the second cam portion 132, and the tip portion of the convex portion 96 slightly protrudes to the right with respect to the main body portion 131. That is, the drum drive transmission members 92 and the advance / retreat members 112 of the development drive transmission members 93 are all retracted to the retracted positions.
(2) First Cover Interlocking Mechanism In the printer 1, the drive linear cam 94 moves in conjunction with the opening and closing of the top cover 4. That is, the printer 1 includes a first cover interlocking mechanism 140 for moving the driving linear cam 94 in conjunction with opening and closing of the top cover 4.

  As shown in FIG. 8, the top cover 4 has a front end portion that is pivoted through a substantially C-shaped rotation support portion 141 provided at the rear end portion thereof so that the front end portion of the top cover 4 is the main casing 2. It is lifted from (refer FIG. 1), and is provided so that opening and closing is possible in the state which open | releases the upper surface of the main body casing 2, and the state which obstruct | occludes the upper surface of the main body casing 2 along the upper surface of the main body casing 2.

As shown in FIG. 9, the first cover interlocking mechanism 140 includes a first cover link member 142 and a second cover link member 143. The first cover link member 142 and the second cover link member 143 are provided in association with the left and right body frames 62 and 63 (see FIG. 6). The first cover link member 142 and the second cover link member 143 provided in relation to the left main body frame 62, and the first cover link member 142 and the second cover link provided in relation to the right main body frame 62 Since the member 143 has a bilaterally symmetric configuration, the following description will be made by taking up the first cover link member 142 and the second cover link member 143 provided in association with the left main body frame 62. To do.

  As shown in FIG. 10, the 1st cover link member 142 is formed in linear form long. One end portion of the first cover link member 142 is coupled to a midway portion in the front-rear direction of the left end portion of the inner surface of the top cover 4 so as to be rotatable about an axis along the left-right direction. The first cover link member 142 extends in the front-rear direction along the inner surface of the top cover 4 with the top cover 4 closed. The other end portion 144 of the first cover link member 142 is coupled to the rear end portion of the main body frame 62 so as to be rotatable about an axis along the left-right direction. In addition, a connecting shaft 145 that protrudes rightward is formed at the rearmost end portion of the first cover link member 142.

  The second cover link member 143 is formed in a V shape in a side view opened at a relatively large angle (for example, about 135 °). A support shaft 146 that protrudes to the right is formed at the bent portion of the second cover link member 143. The second cover link member 143 is rotatably provided around the support shaft 146 by the support shaft 146 being rotatably supported by the rear end portion of the main body frame 62. A connection shaft 145 of the first cover link member 142 is rotatably inserted into one end portion of the second cover link member 143. A connecting shaft 147 that protrudes rightward is formed at the other end of the second cover link member 143. A long hole 148 that is long in the vertical direction is formed in the rear end portion of the main body 131 of the drive linear cam 94, and the connecting shaft 147 is rotatable and movable in the vertical direction in the long hole 148. It is inserted in a loose fit state.

  When the top cover 4 is opened from the state in which the top cover 4 is closed (the state shown in FIG. 10), the first cover link member 142 rotates so as to stand up around the other end portion 144. With the rotation of the first cover link member 142, one end of the second cover link member 143 is pushed forward by the connecting shaft 145, the second cover link member 143 rotates about the support shaft 146, and the second The other end of the cover link member 143 moves backward. Then, when the other end portion of the second cover link member 143 moves rearward, the driving linear cam 94 is pushed rearward by the connecting shaft 147, and the driving linear cam 94 moves rearward. When the top cover 4 is fully opened, the driving linear motion cam 94 is disposed at the rearmost position as shown in FIG.

When the top cover 4 is closed from the opened state, the first cover link member 142 rotates so as to tilt around the other end portion 144. As the first cover link member 142 rotates, one end of the second cover link member 143 is pushed rearward by the connecting shaft 145, the second cover link member 143 rotates about the support shaft 146, and the second The other end of the cover link member 143 moves forward. Then, when the other end portion of the second cover link member 143 moves forward, the driving linear cam 94 is pushed forward by the connecting shaft 147, and the driving linear cam 94 moves forward. When the top cover 4 is completely closed, as shown in FIG. 10, the driving linear cam 94 is disposed at a relatively forward position.
5. Lock Mechanism FIG. 20 is a left side view of the lock mechanism and shows a state in which the top cover is closed. FIG. 21 is a left side view of the lock mechanism, showing a state in which the top cover is opened.

20 and 21 show a drive linear cam 94, a first cover interlocking mechanism 140, a blocking member 191, a contact / separation driving mechanism 211, and a second cover interlocking mechanism 231 described later.
The printer 1 is provided with a lock mechanism 151 for fixing each process cartridge 3 to the main body frames 62 and 63 (see FIG. 6).

The lock mechanism 151 includes four left-side fixing members 152, four right-side fixing members 172 (see FIG. 22), and a pair of right / left direct-acting cams 153 for fixing / contacting / separating.
(1) Left side fixing members The four left side fixing members 152 are arranged on the left side of the left main body frame 62. The four left side fixing members 152 are provided corresponding to the respective process cartridges 3, and each process cartridge 3 (drum cartridge 7) is mounted in the state where the four process cartridges 3 are mounted in the main body casing 2. It arrange | positions ahead with respect to the protection part 30 (refer FIG. 3). The left fixing member 152 includes a lock lever 154, an urging lever 155, and a coil spring 156.

  One end (base end) of the lock lever 154 is rotatably supported by a protrusion 74 (see FIG. 7) formed on the left main body frame 62. A substantially rectangular hole 157 is formed through the center of the lock lever 154. The other end portion (tip portion) of the lock lever 154 has a front end formed in a curved shape corresponding to the outer shape of the protection portion 30 of the process cartridge 3. On the right side surface of the lock lever 154, an operation portion 171 protruding rightward is formed at a position closer to the base end portion than the hole 157.

  The urging lever 155 is disposed on the front side and the right side of the lock lever 154, and one end portion (base end portion) thereof is rotatably supported by the protruding portion 74 (see FIG. 7). At the center of the urging lever 155, a flange 158 is formed that protrudes forward and has a tip bent to the left. The distal end portion of the flange portion 158 is inserted into the hole 157 of the lock lever 154 from the right side. In addition, a connecting shaft 159 that protrudes leftward from the left side surface is formed at the center of the biasing lever 155. Further, a support portion 160 (see FIG. 25) for supporting a spacing member 201 described later is formed at the center of the urging lever 155. The support portion 160 protrudes rightward from the right side surface of the urging lever 155, passes through the hole 187 (see FIG. 7) of the main body frame 62, and the tip thereof is located on the right side of the main body frame 62.

The coil spring 156 is interposed between the distal end portion of the lock lever 154 and the distal end portion of the biasing lever 155.
(2) Right Fixing Member FIG. 22 is a right side view of a part of the right main body frame, showing a state in which the top cover is closed. FIG. 23 is a right side view of a part of the right body frame, showing a state in which the top cover is opened.

The four right fixing members 172 are provided corresponding to the respective process cartridges 3 and are arranged on the right side of the right main body frame 62. The right fixing member 172 includes a lock lever 174, an urging lever 175, and a coil spring 176.
The lock lever 174 is formed in a substantially C shape in a side view. One end portion (base end portion) of the lock lever 174 is rotatably supported by a protruding portion 79 formed on the right body frame 63. A substantially rectangular hole 177 is formed through the other end portion (tip portion) of the lock lever 174. Further, the lock lever 174 is formed with a notch portion 178 that is notched in a concave shape that is recessed downwardly between the base end portion and the tip end portion.

The urging lever 175 is disposed on the front side and the left side of the lock lever 174, and one end portion (base end portion) thereof is rotatably supported by the projecting portion 79. A locking portion 180 that protrudes to the right is formed at the tip of the urging lever 175. The distal end portion of the locking portion 180 is inserted into the hole 177 of the lock lever 174 from the left side. A connecting shaft 179 is formed at the center of the biasing lever 175 so as to protrude rightward from the right side surface. Further, although not shown in the drawing, a support portion that protrudes to the right from the right side surface of the biasing lever 175 is formed in the central portion of the biasing lever 175, and a spacing member 201 (to be described later) is rotated on this support portion. Supported as possible.

The coil spring 176 is interposed between the distal end portion of the lock lever 174 and the distal end portion of the biasing lever 175.
(3) Fixed / contact / separation linear motion cam FIG. 24 is a left side view of the fixed / contact / separation linear motion cam.
Since the right and left fixed / contact / separation direct acting cams 153 have a symmetrical configuration, the structure will be described below by taking the left fixed / contact / separation direct acting cam 153 as an example.

The fixed / contact / separation direct acting cam 153 is a member extending in the front-rear direction, and is attached to the inner surface of the main body frame 62 (see FIG. 6) so as to be capable of reciprocating linear movement in the front-rear direction.
Four guide grooves 161 are formed on the left side surface of the fixed / contact / separation direct acting cam 153 so as to correspond to the respective fixed / contact / separation direct acting cams 153. The guide groove 161 includes a linear groove portion 162 that extends long in the front-rear direction, and an intersecting groove portion 163 that extends obliquely upward and rearward from the rear end of the linear groove portion 162.

  Four third cam portions 164 are formed on the upper surface of the fixed / contact / separation direct acting cam 153 at intervals in the front-rear direction. The four third cam portions 164 are formed in a substantially trapezoidal shape in a side view protruding upward from the upper surface 350 (allowable surface) of the fixed / contact / separation linear motion cam 153, and extend in the front-rear direction and a horizontal surface 165 (separation surface). The inclined surface 166 (allowable surface) is continuous to the rear end edge of the horizontal surface 165 and the upper surface of the fixed / contact / separation linear motion cam 153. The interval between the foremost third cam portion 164 and the third cam portion 164 adjacent thereto is made longer than the interval between the third cam portions 164 adjacent to each other.

A rack gear 167 is formed on the lower surface of the front end portion of the fixed / contact / separation linear motion cam 153. As shown in FIG. 10, a pinion gear 168 is engaged with the rack gear 167 of the left fixed / contact / separation direct acting cam 153. On the other hand, as shown in FIG. 8, a pinion gear 169 is meshed with the rack gear 167 of the fixed / contact / separation linear cam 153 in the right river. The left and right pinion gears 168 and 169 are non-rotatably attached to the left end portion and the right end portion of the connecting shaft 170, respectively. As a result, when the left fixed / contact / separation direct acting cam 153 moves in the front-rear direction, the right fixed / contact / separate direct acting cam 153 is synchronized with the left fixed / contact / separate direct acting cam 153. Move the same amount in the same direction as.
(4) Link member As shown in FIGS. 20 and 21, each left side fixing member 152 and the left side fixed / contact / separation direct acting cam 153 are connected by a link member 181.

  One end of the link member 181 is inserted so that the connecting shaft 159 of the left fixing member 152 can rotate within a predetermined angle range. Specifically, a substantially fan-shaped hole 182 is formed at one end of the link member 181. The connecting shaft 159 is formed in a side-view keyhole shape having a protrusion on its peripheral surface. Then, the connecting shaft 159 is inserted through the hole 182 so that the link member 181 can rotate within a predetermined angle range around the connecting shaft 159. On the other hand, a connecting shaft 183 that protrudes rightward is formed at the other end of the link member 181. The connecting shaft 183 is inserted into the guide hole 75 of the main body frame 62, and the distal end portion thereof is fitted in the guide groove 161.

Each right-side fixing member 172 and right-side fixing / contact / separation direct acting cam 153 are connected by a link member 184 as shown in FIGS.
One end of the link member 184 is inserted so that the connecting shaft 179 of the right fixing member 172 can rotate within a predetermined angle range. Specifically, a substantially fan-shaped hole 185 is formed at one end of the link member 184. The connecting shaft 179 is formed in a side-view keyhole shape having a protrusion on its peripheral surface. The connecting shaft 179 is inserted into the hole 185, whereby the link member 184 can rotate within a predetermined angle range around the connecting shaft 179. On the other hand, a connecting shaft 186 is formed at the other end of the link member 184 so as to protrude toward the left. The connecting shaft 183 is inserted into the guide hole 80 of the main body frame 63, and the tip portion thereof is fitted in the guide groove 161.
6). Blocking Member The printer 1 is provided with four blocking members 191 as shown in FIGS. The four blocking members 191 are arranged on the left side of each left side fixing member 152.

The blocking member 191 is formed in an arm shape. An insertion hole 192 is formed at one end (base end) of the blocking member 191. A caulking shaft 351 (see FIG. 7) is inserted into the insertion hole 192 at a position slightly spaced forward from the lower end of the process guide groove 71 in the main body frame 62 (see FIG. 7). Therefore, each blocking member 191 is supported by the main body frame 62 so as to be rotatable about the insertion hole 192 (caulking shaft 351). The blocking member 191 has a distal end abutting on the operation portion 171 of the left fixing member 152 (lock lever 154) from above and extending in the front-rear direction. The distal end portion of the blocking member 191 is formed in a hook shape that extends upward and is folded downward. In the right side fixing member 172, the lock lever 174 corresponds to the blocking member 191 (see FIG. 23).
7). FIG. 25 is a right side view of a part of the left main body frame, showing a state in which the top cover is closed. FIG. 26 is a right side view of a part of the left main body frame, showing a state in which the top cover is opened.

  The printer 1 is provided with a total of eight spacing members 201 corresponding to each of the four left side fixing members 152 and the four right side fixing members 172 (see FIG. 22). Since the spacing member 201 provided corresponding to the left side fixing member 152 and the spacing member 201 provided corresponding to the right side fixing member 172 have a bilaterally symmetric configuration, the configuration of the left side spacing member will be described below. 201 will be described.

The four spacing members 201 are disposed on the inner side (right side) of the left main body frame 62 so as to face the corresponding left fixing member 152 in the left-right direction.
The separation member 201 is formed in a substantially triangular plate shape. A support portion 160 provided on the urging lever 155 of the left fixing member 152 is inserted into one corner portion 202 of the separation member 201 so as to be relatively rotatable. Thereby, the separation member 201 is rotatably supported by the support portion 160.

The separation member 201 is provided so as to extend rearward from the support portion 160, and is placed on the upper surface of the fixed / contact / separation direct acting cam 153. A lower projecting portion 203 that projects downward is formed at the rear end portion of the separation member 201. The lower protrusion 203 is in contact with the upper surface of the fixed / contact / separation direct acting cam 153. Further, an upper protruding portion 204 that protrudes upward is formed at the rear end portion of the separation member 201. The front side surface of the upper protruding portion 204 is a pressing surface 205.
8). Contact / Separation Drive Mechanism The printer 1 includes a contact / separation drive mechanism 211 for reciprocating the fixed / contact / separation linear motion cam 153 in the front-rear direction, as shown in FIGS. ing.

The contact / separation drive mechanism 211 is provided integrally with the motor gear 212 that rotates by the driving force of the contact / separation motor 229 (see FIG. 27), the pinion gear 168, and the intermediate gear 213 that can rotate together with the pinion gear 168. A planetary differential clutch 214 for transmitting / interrupting rotational force to the intermediate gear 213 and a clutch engagement lever 215 for switching transmission / interruption of rotational force by the planetary differential clutch 214 are provided.

  As shown in FIGS. 10 and 13, the planetary differential clutch 214 includes a shaft 216 held by a holder 103 (see FIG. 15A). An input gear 217, an engagement gear 218, and an output gear 219 are rotatably supported on the shaft 216. A motor gear 212 is engaged with the input gear 217. The engagement gear 218 is disposed on the right side of the input gear 217, and has a large number of teeth that can engage the clutch engagement lever 215 on the outer peripheral surface thereof. The output gear 219 is disposed on the right side of the engagement gear 218. The output gear 219 is formed with a smaller diameter than the input gear 217 and meshes with the intermediate gear 213.

  The clutch engagement lever 215 is disposed above the engagement gear 218 so as to extend in the front-rear direction. As shown in FIGS. 9 and 12, the clutch engaging lever 215 is supported by a support member 220 having a rear end portion attached to the holder 103, and is swingable about the support member 220. As shown in FIG. 12, a claw 221 is formed on the lower surface of the distal end portion of the clutch engagement lever 215.

  The other end of the coil spring 222 whose one end is locked to the holder 103 is locked to the intermediate portion of the clutch engaging lever 215. By this coil spring 222, the clutch engaging lever 215 is urged so that its tip end portion is lifted upward. 9, the front end of the clutch engaging lever 215 is lifted upward by the biasing force of the coil spring 222, and the front end of the driving linear cam 94 is located. Opposite the part with a space in front. From this state, as shown in FIG. 12, when the driving linear cam 94 is moved to the forefront position, the driving linear cam 94 abuts on the clutch engaging lever 215 during the movement, and the driving is performed. The front end portion of the clutch engagement lever 215 is pushed down against the biasing force of the coil spring 222 by the linear motion cam 94. As a result, the claw 221 of the clutch engagement lever 215 enters between the teeth of the engagement gear 218, and the clutch engagement lever 215 engages with the engagement gear 218.

  When the clutch engagement lever 215 is engaged with the engagement gear 218, the engagement gear 218 cannot rotate, and the rotational force input from the motor gear 212 to the input gear 217 is transmitted to the output gear 219. That is, the planetary differential clutch 214 transmits the rotational force of the motor gear 212 to the intermediate gear 213. Therefore, the forward and reverse rotation of the motor gear 212 can cause the pinion gear 168 to rotate forward and backward together with the intermediate gear 213, and the fixed / contact / separation linear motion cam 153 can be reciprocated in the front-rear direction.

On the other hand, when the clutch engagement lever 215 is not engaged with the engagement gear 218, the rotational force input from the motor gear 212 to the input gear 217 is transmitted to the engagement gear 218 and not transmitted to the output gear 219. . That is, the planetary differential clutch 214 blocks transmission of the rotational force of the motor gear 212 to the intermediate gear 213. At this time, the output gear 219 is in a freely rotatable state, and the contact / separation motor 229 (see FIG. 27) does not become a load with respect to the movement of the fixed / contact / separation linear motion cam 153.
8). Second Cover Interlocking Mechanism In the printer 1, the driving linear motion cam 94 moves in conjunction with the opening and closing of the top cover 4, and as the driving linear motion cam 94 moves, the fixed / contact / separation direct movement is performed. The moving cam 153 moves in conjunction with each other. That is, as shown in FIGS. 20 and 21, the printer 1 has a fixed / contacting / separating linear cam together with the interlocking of the driving linear cam 94 by the first cover interlocking mechanism 140 as the top cover 4 is opened and closed. A second cover interlocking mechanism 231 for interlockingly moving 153 is provided.

The second cover interlocking mechanism 231 includes a third cover link member 232 and a fourth cover link member 233.
The third cover link member 232 is a member extending linearly, and a shaft 234 protruding leftward is formed at an intermediate portion thereof. The shaft 234 is rotatably supported by the holder 103 (see FIG. 15A). One end of the third cover link member 232 is coupled to the drive linear cam 94 so as to be rotatable about an axis along the left-right direction.

  The fourth cover link member 233 is a member extending linearly, and is fixed in a posture substantially along the front-rear direction with respect to the left side surface of the fixed / contact / separation linear motion cam 153. The other end of the third cover link member 232 (the end opposite to the one end coupled to the drive linear cam 94) and the rear end of the fourth cover link member 233 are along the left-right direction. The shafts are coupled to each other so as to be rotatable around the axis.

  In the state in which the top cover 4 is closed, as shown in FIG. 20, the driving linear motion cam 94 is disposed at a relatively forward position, and the fixed / contacting / separating linear cam is provided. 153 is arranged at the rearmost position. At this time, one end portion of the third cover link member 232 is positioned in front of the rear end portion of the fourth cover link member 233, and the third cover link member 232 and the fourth cover link member 233 are between them. An acute angle is formed. When the top cover 4 is opened and the driving linear cam 94 moves rearward, one end of the third cover link member 232 moves rearward, and the third cover link member 232 rotates about the shaft 234. As the third cover link member 232 rotates, the fourth cover link member 233 is pushed forward by the other end of the third cover link member 232, and the fixed / contact / separation linear motion cam 153 moves forward. . When the top cover 4 is fully opened, as shown in FIG. 21, the fixed / contact / separation direct acting cam 153 is disposed at the foremost position.

  While the top cover 4 is being opened, the driving linear cam 94 moves rearward, so that the driving linear cam 94 is separated from the clutch engaging lever 215. Then, the tip of the clutch engagement lever 215 is lifted upward, and the engagement of the clutch engagement lever 215 with the engagement gear 218 is released. Therefore, the contact / separation motor 229 (see FIG. 27) does not become a load with respect to the movement of the fixed / contact / separation direct acting cam 153, and smooth movement of the fixed / contact / separation direct acting cam 153 is achieved.

In the state where the top cover 4 is fully opened, as shown in FIG. 21, one end portion of the third cover link member 232 is located on the rear side of the rear end portion of the fourth cover link member 233, and The cover link member 232 and the fourth cover link member 233 form an obtuse angle between them. When the top cover 4 is closed and the driving linear cam 94 moves forward, one end of the third cover link member 232 moves forward, and the third cover link member 232 rotates around the shaft 234. As the third cover link member 232 rotates, the fourth cover link member 233 is pulled backward by the other end of the third cover link member 232, and the fixed / contact / separation linear motion cam 153 moves rearward. . When the top cover 4 is completely closed, as shown in FIG. 20, the fixed / contact / separation linear motion cam 153 is disposed at a relatively rear position. 9. 21. Operation of Lock Mechanism (Left Side Fixing Member and Right Side Fixing Member) and Blocking Member Accompanying Opening and Closing of Top Cover When the top cover 4 is opened, the connecting shaft 183 of each link member 181 on the left side is as shown in FIG. The straight hole 76 (see FIG. 7) of the guide hole 75 of the main body frame 62 is inserted, and the front end of the guide frame is fitted into the intersecting groove 163 (see FIG. 24) of the guide groove 161. Further, as shown in FIG. 23, the connecting shaft 183 of each link member 184 on the right side is inserted into the straight hole portion 81 (see FIG. 22) of the guide hole 80 of the main body frame 63, and the tip portion thereof is the guide groove 16.
1 is fitted into one crossing groove 163. As shown in FIG. 21, each left-side fixing member 152 tilts forward, retracts from the attachment / detachment path of the process cartridge 3, and is in a position not facing the process guide groove 71 (see FIG. 7) in the left-right direction. . In addition, each blocking member 191 is in a position (blocking position) where the foremost portion of the blocking member 191 contacts the operation unit 171 and faces the lower end portion of the process guide groove 71 in the left-right direction. As shown in FIG. 23, each right-side fixing member 172 has a notch 178 of the lock lever 174 facing the lower end of the process guide groove 78 in the left-right direction, and the bottom surface of the notch 178 extends in a direction along the process guide groove 78. It is in a position (blocking position) so as to be substantially orthogonal.

  In this state, the process cartridge 3 can be attached to and detached from the main casing 2. When the process cartridge 3 is mounted, the protection portion 30 (see FIG. 3) of the process cartridge 3 (drum cartridge 7) is fitted in the process guide groove 71, and the right end portion of the drum shaft 45 is fitted in the process guide groove 78, thereby The cartridge 3 is moved obliquely downward and rearward. Thus, the process cartridge 3 is mounted in the main casing 2 while the protection unit 30 and the drum shaft 45 are guided by the process guide grooves 71 and 78, respectively. Further, when the process cartridge 2 is detached, the process cartridge 3 is lifted obliquely upward and forward while the protection portion 30 and the drum shaft 45 are guided by the process guide grooves 71 and 78, respectively.

  When the top cover 4 is opened, the blocking member 191 faces the lower end of the process guide groove 71 in the left-right direction, and the notch 178 of the lock lever 174 faces the lower end of the process guide groove 78 in the left-right direction. Therefore, when the process cartridge 3 is attached to the inside of the main casing 2, the protection unit 30 comes into contact with the blocking member 191 or the drum shaft 45 comes into contact with the lock lever 174. Movement is prevented. That is, the mounting of the process cartridge 3 on the main body casing 2 is blocked when the protection unit 30 comes into contact with the blocking member 191 or when the drum shaft 45 comes into contact with the lock lever 174.

  When the top cover 4 is closed, the driving linear motion cam 94 moves forward, and the fixed / contact / separation linear motion cam 153 moves rearward. As shown in FIG. 21, the connecting shaft 183 of each link member 181 on the left side is fitted to the intersecting groove portion 163 (see FIG. 24) of the guide groove 161. For this reason, when the fixed / contact / separation linear cam 153 moves rearward, the distal end portion of the connecting shaft 183 is fitted in the intersecting groove portion 163, and the straight hole portion 76 of the guide hole 75 of the main body frame 62 (see FIG. 7). Move backwards. As a result, each link member 181 rotates so that one end thereof is lifted, and with the rotation of the link member 181, each left-side fixing member 152 has a protrusion 74 (see FIG. 7) formed on the main body frame 62. Rotate backward to center. As a result, each left-side fixing member 152 is in a locked state and is disposed on the attachment / detachment path of the process cartridge 3, and the front end edge of the front end portion of the lock lever 154 contacts the protection unit 30 of the process cartridge 3. It is pushed diagonally downward and rearward.

  In addition, as shown in FIG. 20, with the rotation of each left-side fixing member 152, the operation portion 171 moves rearward with respect to each blocking member 191, and each blocking member 191 rotates so that the tip portion thereof is lowered. Then, it moves to a position (allowable position) where the operation portion 171 contacts the bent portion of the tip portion. As a result, the process cartridge 3 moves downward, and as shown by a broken line in FIG. 7, the protection part 30 comes into contact with the contact parts 72 and 73, and the process cartridge 3 is fixed at that position.

On the other hand, the connecting shaft 186 of each link member 184 on the right side is fitted in the intersecting groove portion 163 of the guide groove 161 at its tip end portion. Therefore, when the fixed / contact / separation linear cam 153 moves rearward, the straight end portion 81 of the guide hole 80 of the main body frame 63 (see FIG. 22) while the tip end portion of the connecting shaft 186 is fitted in the intersecting groove portion 163. Move backwards. Thus, each link member 18
4 rotates so that one end part is lifted, and each right-side fixing member 172 rotates rearward around a protrusion 79 (see FIG. 23) formed in the main body frame 63 as the link member 184 rotates. . As a result, as shown in FIG. 22, each right-side fixing member 172 is locked, the front end of the notch 178 of the lock lever 174 contacts the drum shaft 45, and the drum shaft 45 is pressed obliquely downward and rearward. . As a result, the photosensitive drum 5 is fixed on both the left and right sides.

  Further, while the top cover 4 is being closed, the driving linear motion cam 94 comes into contact with the clutch engaging lever 215, and the leading end of the clutch engaging lever 215 is pushed downward by the driving linear motion cam 94, The clutch engagement lever 215 is engaged with the engagement gear 218. Therefore, after the top cover 4 is closed, the fixed / contact / separation linear motion cam 153 can be moved by the driving force of the contact / separation motor 229 (see FIG. 27).

  Further, when the top cover 4 is being closed, the drive linear cam 94 moves forward, so that the advance / retreat member 112 of each drum drive transmission member 92 and each development drive transmission member 93 is moved as shown in FIG. Advance to the advance position. Each drum drive transmission member 92 is coupled to each connecting member 47, and each advance / retreat member 112 is coupled to each developing passive gear 61. As a result, the photosensitive drum 5 and the developing roller 9 can be rotationally driven.

When the top cover 4 is opened from the closed state, each part of the printer 1 performs an operation opposite to the operation when the top cover 4 is closed. Then, the left side fixing member 152 and the right side fixing member 172 are in an unlocked state in which the process cartridge 3 is not fixed.
10. FIG. 27 to FIG. 29 are left side views of the process cartridge, the lock mechanism, and the contact / separation drive mechanism. FIG. 27 shows a state in which all the developing rollers are in contact with the photosensitive drum, FIG. 28 shows a state in which the yellow, magenta and cyan developing rollers are separated from the photosensitive drum, and FIG. 29 shows that all the developing rollers are photosensitive. The state separated from the drum is shown.

  When the top cover 4 is closed, the fixed / contact / separation linear motion cam 153 can be moved by the driving force of the contact / separation motor 229 (see FIG. 27). When the top cover 4 is closed, the fixed / contact / separation linear motion cam 153 moves, and the connecting shaft 183 of the left link member 181 moves to the cross hole 77 (see FIG. 7) of the guide hole 75 of the main body frame 62. After reaching, even if the fixed / contact / separation linear motion cam 153 is further moved rearward, the distal end portion of the connecting shaft 183 moves in the linear groove portion 162 (see FIG. 24) of the guide groove 161, and the link member 181. The posture does not change. Further, after the connecting shaft 186 of the right link member 184 reaches the cross hole portion 82 (see FIG. 23) of the guide hole 80 of the main body frame 63, the fixed / contact / separation linear motion cam 153 is further moved rearward. Even so, the distal end portion of the connecting shaft 186 moves in the linear groove portion 162 of the guide groove 161, and the posture of the link member 184 does not change. Therefore, when the top cover 4 is closed, the state where the process cartridge 3 is fixed can be maintained.

  In the state immediately after the top cover 4 is closed, as shown in FIG. 25, all the separating members 201 have the lower projecting portions 203 that contact the upper surface 350 (see FIG. 24) of the fixed / contact / separation linear motion cam 153. The upper projecting portion 204 is in a position (allowable position) where the upper projecting portion 204 is lowered downward (but not in contact with the third cam portion 164). Therefore, as shown in FIG. 27, the upper projecting portion 204 of each spacing member 201 is separated from the developing bearing members 57 and 58 protruding from the developing cartridge 9 on the left and right sides, and all the developing rollers 8 (see FIG. 1) are exposed to light. The drum 5 is in contact with the drum 5 (see FIG. 1).

When the fixed / contact / separation direct acting cam 153 is moved rearward from this state, the lower protrusions 203 of the separation member 201 corresponding to the yellow process cartridge 3Y, the magenta process cartridge 3M, and the cyan process cartridge 3C respectively. The third cam portion 164 moves on the inclined surface 166 and moves from the horizontal surface 165 to the inclined surface 166. As a result, as shown in FIG. 26, the spacing members 201 are in a position (separation position) in which the lower protruding portion 203 is in contact with the horizontal surface 165 and the upper protruding portion 204 is relatively lifted upward. As a result, as shown in FIG. 28, the developing bearing members 57 and 58 of the yellow, magenta and cyan developing cartridges 9 are pressed from below with the pressing surface 205 of the upper protruding portion 204 extending in the vertical direction from the rear. The yellow, magenta and cyan developing cartridges 9 are lifted upward, and the developing roller 8 provided in these developing cartridges 9 is separated from the photosensitive drum 5. At this time, the developing roller 8 provided in the black developing cartridge 9 is in contact with the photosensitive drum 5.

  When the fixed / contact / separation direct acting cam 153 is further moved backward from this state, the lower protrusion 203 of the separation member 201 corresponding to the black process cartridge 3K moves on the inclined surface 166 of the third cam portion 164. Move and move from the horizontal surface 165 to the inclined surface 166. As a result, the separation member 201 is in a position (separation position) in which the lower protrusion 203 comes into contact with the horizontal surface 165 and the upper protrusion 204 is lifted relatively upward. As a result, as shown in FIG. 29, the developing bearing members 57 and 58 of the black developing cartridge 9 are pressed from below with the pressing surface 205 of the upper projecting portion 204 along the vertical direction from the rear, and the black developing cartridge 9 is lifted upward, and all the developing rollers 8 are separated from the photosensitive drum 5.

Even when the developing cartridge 9 is moved up and down in a state where each advancement / retraction member 112 is coupled to each development passive gear 61, the longitudinal diameter of the long hole 36 through which the advancement / retraction member 112 is inserted, as shown in FIG. Since it is formed long, the coupling does not hinder the vertical movement of the developing cartridge 9.
11. Effects As described above, the drum frame 21 holds the photosensitive drum 5 and the connecting member 47 to which a driving force for rotating the photosensitive drum 5 is input. The drum frame 21 is provided with a substantially cylindrical protective portion 30 protruding in the direction of the rotation axis of the photosensitive drum 5. The connecting member 47 is disposed (accommodated) inside the protection unit 30. Thereby, it is possible to prevent the connecting member 47 from being damaged due to collision with other members when the process cartridge 3 is attached to or detached from the inside of the main casing 2.

The protruding amount of the rear portion 31 of the protection part 30 is smaller than the protruding amount of the front portion 32. Therefore, when the process cartridge 3 is mounted on the main casing 2, the rear portion 31 of the protection unit 30 is not caught by a member disposed in the main casing 2, and the process cartridge 3 is smoothly mounted on the main casing 2. Is possible.
Further, in a state where the process cartridge 3 is mounted on the main body casing 2, the difference between the protruding amount of the rear portion 31 of the protective portion 30 and the protruding amount of the front portion 32 relative to the rear portion 31 of the protective portion 30. A space is generated in a portion of the photosensitive drum facing the rotation axis. Therefore, a drum drive transmission member 92 (see FIG. 4) for inputting driving force to the connecting member 47 can be disposed in this space. As a result, the size of the photosensitive drum 5 in the main body casing 2 in the rotation axis direction can be reduced.

Further, when the process cartridge 3 is attached to or detached from the main casing 2, the protection unit 30 is guided to the process guide groove 78 provided in the main casing 2. Therefore, the process cartridge 3 can be more smoothly mounted on the main body casing 2.
The left side fixing member 152 presses the process cartridge 3 in the locked state, and brings the process cartridge 3 into contact with the contact portion. When the process cartridge 3 is pressed while being in contact with the contact portions 72 and 73, the process cartridge 3 is fixed at a position where the process cartridge 3 is in contact with the contact portions 72 and 73. Thereby, positioning of the process cartridge 3 in the main body casing 2 can be achieved.

  The fixing of the process cartridge 3 is released when the left side fixing member 152 and the right side fixing member 172 are displaced from the locked state to the unlocked state. That is, the fixing of the process cartridge 3 is released when the left side fixing member 152 and the right side fixing member 172 are separated from the process cartridge 3. By releasing the fixing of the process cartridge 3, the process cartridge 3 can be detached from the main body casing 2.

Further, the protective member 30 protruding in the direction of the rotation axis of the photosensitive drum 5 from the drum frame 21 of the process cartridge 3 is pressed by the left fixing member 152. Therefore, reliable pressing of the process cartridge 3 by the left side fixing member 152 can be easily achieved.
Further, the drum drive transmission member 92 is engaged with the connecting member 47, and the driving force is transmitted from the drum drive transmission member 92 to the connecting member 47, whereby the photosensitive drum 5 rotates. The drum drive transmission member 92 can transmit the driving force to the drum drive input unit 92 while allowing the displacement of the connecting member 47 within a predetermined range. As a result, even if the connecting member 47 is displaced from the normal position, if the displacement is within a predetermined range, good transmission of the driving force from the drum drive transmitting member to the connecting member 47 can be achieved.
12 Other Embodiments Although the tandem color printer 1 has been taken up, the present invention is an intermediate in which a toner image for each color is transferred from each image carrier to an intermediate transfer belt and then transferred from the intermediate transfer belt to a sheet at a time. It can also be applied to a transfer type color printer.

  The present invention can also be applied to a monochrome printer.

1 is a side sectional view showing an embodiment of a printer as an example of an image forming apparatus of the present invention. It is a perspective view from the right front direction of a process cartridge. It is a left view of a process cartridge. It is a top view of a process cartridge. It is a perspective view from the right front direction of a drum cartridge. It is a perspective view from the right front direction in a main body casing. It is a left view of the left main body frame. It is a perspective view from the left front direction of a driving force transmission mechanism and a 1st cover interlocking mechanism. It is a left view of a driving force transmission mechanism and a 1st cover interlocking mechanism, and shows the state where the top cover was closed. It is a perspective view from the right front direction of a driving force transmission mechanism and a 1st cover interlocking mechanism, and shows the state in which the top cover was closed. It is a top view of a driving force transmission mechanism, and shows the state where the top cover was closed. It is a left view of a driving force transmission mechanism and a 1st cover interlocking mechanism, and shows the state where the top cover was opened. It is a perspective view from the right front direction of a driving force transmission mechanism and a 1st cover interlocking mechanism, and shows the state where the top cover was opened. It is a top view of a driving force transmission mechanism, and shows the state where the top cover was opened. It is sectional drawing of the drum drive transmission member in an advance position. It is sectional drawing of the drum drive transmission member in a retracted position. It is a perspective view of a drum main body, a flange member, a connection member, and a drum drive transmission member. It is a right view of a drum drive transmission member. It is a left view of a connection member. It is a left view of a flange member. It is sectional drawing of the development drive transmission member in an advance position. It is sectional drawing of the development drive transmission member in a retracted position. It is a right view of an advance / retreat member. It is a left view of a development passive gear. It is a left view of a locking mechanism, and shows the state where a top cover was closed. It is a left view of a lock mechanism, and shows the state where a top cover was opened. FIG. 6 is a right side view of a part of the right main body frame, showing a state in which the top cover is closed. FIG. 6 is a right side view of a part of the right main body frame, showing a state in which the top cover is opened. It is a left side view of a fixed / contact / separation linear motion cam. FIG. 6 is a right side view of a part of the left main body frame, showing a state in which the top cover is closed. FIG. 6 is a right side view of a part of the left main body frame, showing a state in which the top cover is opened. FIG. 4 is a left side view of a process cartridge, a lock mechanism, and a contact / separation drive mechanism, showing a state where all the developing rollers are in contact with the photosensitive drum. FIG. 4 is a left side view of a process cartridge, a lock mechanism, and a contact / separation drive mechanism, showing a state in which yellow, magenta, and cyan developing rollers are separated from the photosensitive drum. FIG. 4 is a left side view of a process cartridge, a lock mechanism, and a contact / separation drive mechanism, showing a state where all the developing rollers are separated from the photosensitive drum.

DESCRIPTION OF SYMBOLS 1 Printer 2 Main body casing 3 Process cartridge 5 Photosensitive drum 30 Protection part 31 Rear side part 32 Front side part 47 Connection member 71 Process guide groove 92 Drum drive transmission member 152 Left side fixing member

Claims (3)

A photosensitive drum rotatable about a rotation axis;
A process cartridge comprising a frame on which the photosensitive drum is provided,
The photosensitive drum is
A cylindrical drum body;
A flange member fixed to an end of the drum body in the rotation axis direction;
A drum drive input unit provided on an end surface of the flange member in the rotation axis direction, to which a driving force for rotating the photosensitive drum is input,
The frame has a first protrusion that protrudes so as to expose an end face of the flange member in the rotation axis direction;
The first protrusion is
A first part;
A second portion having a smaller protrusion than the first portion so as to generate a space for arranging a drum drive transmission member that transmits a driving force to the drum drive input portion in the rotation axis direction;
A process cartridge comprising: The photosensitive drum has a metal shaft extending in the rotation axis direction,
The shaft has a protruding portion protruding from the frame in the rotation axis direction;
2. The process cartridge according to claim 1, wherein the frame includes a cylindrical second projecting portion projecting in the rotation axis direction so as to surround the projecting portion. A developing roller configured to face the photosensitive drum and supply a developer to the photosensitive drum;
The frame has a third protrusion that protrudes in the axial direction on the opposite side of the drum drive input portion across the developing roller in a direction in which the photosensitive drum and the developing roller face each other. The process cartridge according to claim 1 or 2.

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