JP2014071136A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus configured to separate a developing roller from a photoreceptor in drawing a support member and to separate them from each other during image formation and standby state, in a simple configuration.SOLUTION: A developing cartridge 12 having a developing roller 13 facing a photoreceptor drum 9 is arranged in a first contact position and a second contact position in color printing mode and monochrome printing mode, while arranging a drawer frame 11 in an inside position. In printing standby mode, the developing cartridge is arranged in a first separate position. When the drawer frame 11 is moved to an outside position, the developing cartridge is arranged in a second separate position which is separated farther than the first separate position.

Description

  The present invention relates to an image forming apparatus employing an electrophotographic system.

  As an electrophotographic image forming apparatus, an image forming apparatus including a plurality of photoconductors corresponding to each color and a plurality of developing cartridges that supply a developer to each photoconductor is known.

  For example, a photosensitive unit having a plurality of photosensitive drums that can be pulled out from the printer body, a developing unit that is disposed below the photosensitive unit, supports a plurality of developing units, and can be pulled out from the printer body, A printer including a unit elevating mechanism that elevates and lowers the developing unit with respect to the photosensitive unit has been proposed (for example, see Patent Document 1 below).

  In this printer, at the time of image formation or standby (waiting for a command), the developing unit is raised toward the photosensitive unit so that the developing roller of the developing unit is in contact with the photosensitive unit. When the photoreceptor unit or the developer unit is pulled out during maintenance or the like, the developer unit is greatly lowered with respect to the photoreceptor unit so that the photoreceptor unit and the developer unit do not interfere with each other.

JP 2006-184552 A

  However, in the printer described in Patent Document 1, it may be considered that the predetermined developing device is slightly separated from the corresponding photosensitive drum during image formation or standby.

  Specifically, each mode is used to change the printer mode between an image forming mode in which a predetermined developing device contacts a corresponding photosensitive drum and a standby mode in which all the developing devices are separated from the corresponding photosensitive drum. Accordingly, it is considered that a predetermined developing device is brought into contact with or separated from the corresponding photosensitive drum.

  In this case, it is considered to provide a mechanism for changing the printer mode separately from the unit lifting mechanism. However, if the unit lifting mechanism and the mechanism for changing the printer mode are provided separately, the printer There is a risk that the configuration of the system becomes complicated.

  Therefore, an object of the present invention is to realize a separation between the developing roller and the photosensitive member when the support member is pulled out and a separation between the developing roller and the photosensitive member during image formation or standby with a simple configuration. An object of the present invention is to provide an image forming apparatus capable of performing the above.

(1) In order to achieve the above-described object, an image forming apparatus of the present invention is a development having an apparatus main body, a photosensitive member configured to carry an electrostatic latent image, and a developing roller facing the photosensitive member. A cartridge, a support member configured to support the developing cartridge, accommodated in the apparatus main body, movable to an outer position moved from the inner position to the outside of the apparatus main body, and an contacting / separating member; Prepare.

  The contact / separation member includes a developer cartridge, a contact position where the developing roller contacts the photosensitive member, a first separating position where the developing roller is separated from the photosensitive member, and a developing roller separated from the photosensitive member than the first separating position. And a second separated position.

  According to such a configuration, when the image is formed with the support member disposed at the inner position, the developer cartridge is disposed at the contact position, and the developer cartridge is disposed at the first separation position when waiting. Can be made.

  Further, when the support member is moved to the outer position, the developing cartridge can be disposed at a second separated position that is separated from the first separated position.

  As a result, the developing roller can be retracted relatively small from the photosensitive member during image formation or standby, while the developing roller can be retracted relatively large from the photosensitive member when the support member is pulled out.

  That is, the developing roller can be separated from the photosensitive member by a necessary distance during image formation or standby, and when the support member is pulled out.

As a result, with a simple configuration, it is possible to realize separation between the developing roller and the photosensitive member when the support member is pulled out and separation between the developing roller and the photosensitive member during image formation or standby.
(2) A plurality of photoconductors may be arranged in parallel at intervals. Further, a plurality of developing cartridges may be provided so as to correspond to each of the plurality of photosensitive members.

  In this case, the contact position includes a first contact position where all the developing rollers contact the corresponding photosensitive member, a part of the developing rollers contact the corresponding photosensitive member, and the remaining developing rollers from the corresponding photosensitive member. And a second contact position that is spaced apart.

  According to such a configuration, in a configuration having a plurality of photoconductors corresponding to each color, a mode capable of printing all colors and a mode capable of printing only a part of colors using the contact / separation member. In addition, the print mode of the printer can be changed.

Therefore, it is possible to change the printer printing mode with a simple configuration without separately providing a mechanism for changing the printing mode of the printer.
(3) Moreover, the contact / separation member may be movable along the moving direction of the support member.

  According to such a configuration, the moving direction of the contacting / separating member and the moving direction of the support member can be substantially matched.

Therefore, compared with the case where the moving direction of the contacting / separating member and the moving direction of the support member intersect, it is easy to prevent the contacting / separating member from interfering with the support member when the support member is moved. Can do.
(4) The contact / separation member may be provided on the support member.

  According to such a configuration, when the support member is moved, the contact / separation member can also be moved.

Therefore, it is possible to reliably prevent the contact / separation member from interfering with the support member when the support member is moved.
(5) The contact / separation member may be disposed on both sides in the longitudinal direction of the developing cartridge.

  According to such a configuration, the contact / separation member can act on both ends in the longitudinal direction of the developing cartridge.

Therefore, in a state where the developing cartridge is disposed at the contact position, the developing roller can be stably brought into contact with the photosensitive member over both ends in the longitudinal direction.
(6) The developing cartridge may further include a frame that supports the developing roller, a contact member that is in contact with the contact / separation member, and a biasing member that is interposed between the contact member and the frame. Good.

  In this case, when the developing cartridge is disposed at the contact position, the frame may be urged toward the photosensitive member by the urging force of the urging member so that the developing roller contacts the photosensitive member.

  According to such a configuration, the developing roller is elastically contacted with the photosensitive member by the urging force of the urging member when the developing cartridge is disposed at the contact position.

  Therefore, even when the photosensitive member and the developing roller are driven during image formation, the developing roller can follow the photosensitive member.

As a result, the developing roller can be stably brought into contact with the photoreceptor during image formation.
(7) The support member may be movable from the inner position to the outer position when the developing cartridge is disposed at the second separation position.

  According to such a configuration, the support member can be moved from the inner position to the outer position after the developing cartridge is disposed at the second separation position.

  Therefore, it is possible to prevent the support member from being moved from the inner position to the outer position before the developing cartridge is disposed at the second separation position.

As a result, when the support member is moved, it is possible to reliably prevent the developing roller from interfering with surrounding members.
(8) The support member is movable to a fixing position where the contact / separation member is fixed at a position where the developing cartridge is positioned at the second separation position, and a fixing release position where the fixing of the contact / separation member is released. May be provided.

  According to such a configuration, the developing cartridge can be fixed at the second separation position by the fixing member.

  Therefore, it is possible to prevent the developing cartridge from being moved from the second separated position when the support member is moved.

As a result, when the support member is moved, the developing roller can be more reliably prevented from interfering with surrounding members.
(9) The apparatus main body includes an opening for allowing the support member to pass from the inner position to the outer position, an opening position for opening the opening, and an opening / closing member movable to a closed position for closing the opening. You may have.

  In this case, the opening / closing member may include a fixing release member that holds the fixing member in the fixing release position when the opening / closing member is disposed in the closed position.

  According to such a configuration, the contact / separation member can be unlocked using the closing operation of the opening / closing member.

Therefore, the contact / separation member can be reliably moved in a state where the opening / closing member is disposed at the closed position.
(10) The contact / separation member may move the developing cartridge from the first separation position to the second separation position in conjunction with the movement of the opening / closing member from the closed position to the open position.

  According to such a configuration, the developing cartridge can be moved to the second separation position by utilizing the opening operation of the opening / closing member.

Therefore, in a state where the opening / closing member is disposed at the open position, the developing cartridge can be reliably disposed at the second separation position.
(11) The support member may include an operation unit that is operated when the support member is moved. In this case, the operation part may be connected to the contact / separation member. The contact / separation member may move the developing cartridge from the first separation position to the second separation position by operating the operation unit so as to move the support member from the inner position to the outer position.

  According to such a configuration, the developing cartridge can be moved to the second separation position by using the operation of moving the support member from the inner position to the outer position.

Therefore, when the support member is moved, the developing cartridge can be surely arranged at the second separated position.
(12) Further, the developing cartridge may be brought into contact with the photosensitive member from below. In this case, the support member may be disposed to face the lower side of the photoconductor.

  According to such a configuration, the developing cartridge can be easily lowered using gravity.

  According to the image forming apparatus of the present invention, with a simple configuration, separation between the developing roller and the photosensitive member when the support member is pulled out and separation between the developing roller and the photosensitive member during image formation or standby are realized. be able to.

FIG. 1 is a central sectional view of a printer as an embodiment of an image forming apparatus of the present invention. 2 is a perspective view of the drawer unit shown in FIG. 1 as viewed from the upper right side. FIG. 2A shows a state in which the linear cam is disposed at the contact position, and FIG. The state arrange | positioned in the 2nd separation position is shown. 3A and 3B are explanatory views for explaining the drawer frame shown in FIG. 2, wherein FIG. 3A is a perspective view seen from the upper right side of the drawer frame, and FIG. 3B is a view seen from the upper right side of the linear motion cam. FIG. 4 is a perspective view of the developing cartridge shown in FIG. 1 as viewed from the lower right side. FIG. 4A shows a state in which the pressing member is disposed at the pressing position, and FIG. The state arrange | positioned in the press release position is shown. FIG. 5 is a perspective view of the pressing member shown in FIG. 4 as viewed from the upper right side. 6A and 6B are explanatory diagrams for explaining the mode change of the printer. FIG. 6A shows a color printing mode (linear cam: first position, developing cartridge: first contact position), and FIG. Indicates monochrome printing mode (linear cam: second position, developer cartridge: second contact position) FIG. 7 is an explanatory diagram for explaining the printer mode change following FIG. 6. FIG. 7A shows a print standby mode (linear cam: third position, developer cartridge: first separation position). , (B) shows the exchange mode (linear motion cam: fourth position, developing cartridge: second separated position). FIG. 8 is an explanatory view for explaining the replacement operation of the developing cartridge, wherein (a) shows a state in which the front cover is disposed at the closed position and the lock member is disposed at the unlocked position, and (b). These show the state in which the front cover is disposed in the open position and the lock member is disposed in the lock position. FIG. 9 is an explanatory diagram for explaining the replacement operation of the developing cartridge following FIG. 8 and shows a state in which the drawer unit is pulled out from the main body casing. FIG. 10 is an explanatory diagram for explaining drawer drawer drawing in a mode other than the replacement mode. FIG. 10A shows a state in which the front cover is disposed at the closed position and the lock member is disposed at the lock position. (B) shows a state in which the front cover is disposed at the open position and the lock member is disposed at the lock position.

1. Overall Configuration of Printer As shown in FIG. 1, a printer 1 as an example of an image forming apparatus is a horizontal type intermediate transfer type color printer.

  In the following description, when referring to the direction of the printer 1, the state in which the printer 1 is horizontally placed is used as the upper and lower reference. That is, the upper side in FIG. 1 is the upper side (vertical direction (first direction) one side), and the lower side of the paper is the lower side (the other side in the vertical direction). 1 is the front side (front and rear direction (second direction) one side), and the right side of FIG. 1 is the rear side (front and rear direction one side). In addition, when the printer 1 is viewed from the front side, the left and right reference is used. That is, the front side in FIG. 1 is the right side (left and right direction (third direction) one side), and the back side is the left side (the other side in the left and right direction).

  The printer 1 includes an image forming unit 3 for forming an image on a paper P in a main body casing 2 as an example of an apparatus main body.

  The main casing 2 is formed in a substantially box shape. A main body opening 24 as an example of an opening is formed in the front wall of the main body casing 2. The front casing 4 as an example of an opening / closing member is provided in the main casing 2 with an open position (see FIG. 8B) for opening the main body opening 24 with the lower end portion as a fulcrum, and a main body opening 24. It is provided so as to be swingable (movable) at a closed position (see FIG. 8A) for closing. A paper feed tray 5 that accommodates the paper P is detachably attached to the bottom of the main casing 2.

  The image forming unit 3 is disposed on the upper side of the paper feed tray 5 and includes a process unit 6, a transfer unit 7, and a fixing unit 8.

  The process unit 6 includes a photosensitive drum 9 as an example of a plurality (four) of photosensitive members and a drawer unit 10.

  The plurality of photosensitive drums 9 are arranged in parallel at intervals in the front-rear direction. Specifically, a black photosensitive drum 9K, a yellow photosensitive drum 9Y, a magenta photosensitive drum 9M, and a cyan photosensitive drum 9C are sequentially arranged from the front side to the rear side. The photosensitive drum 9 is formed in a substantially cylindrical shape that is long in the left-right direction, and is provided along the left-right direction. In addition, around each of the plurality of photosensitive drums 9, a charger (not shown) disposed opposite to the rear side of the photosensitive drum 9 and an exposure unit (not illustrated) disposed opposite to the rear lower side of the photosensitive drum 9. (Not shown).

  The drawer unit 10 is disposed below the plurality of photosensitive drums 9. The drawer unit 10 includes a drawer frame 11 as an example of a support member, and a plurality (four) of developing cartridges 12.

  The drawer frame 11 is provided so as to be slidable in the front-rear direction at an inner position (see FIG. 10) accommodated in the main casing 2 and an outer position (see FIG. 12) pulled out of the main casing 2. Yes.

  Each of the plurality of developing cartridges 12 is disposed on the front lower side of each of the plurality of photosensitive drums 9. The developing cartridge 12 includes a developing roller 13 as an example of a developer carrier.

  The developing roller 13 is rotatably supported at the upper end of the developing cartridge 12 so that the upper end portion is exposed upward. The developing roller 13 faces and contacts the photosensitive drum 9 from below.

  The developing cartridge 12 includes a supply roller 14 that supplies toner to the developing roller 13. The developing cartridge 12 contains toner as an example of a developer below the supply roller 14.

  The transfer unit 7 includes a belt unit 15 and a secondary transfer roller 16.

  The belt unit 15 is disposed along the front-rear direction on the upper side of the process unit 6 so as to face all the photosensitive drums 9 from above.

  The belt unit 15 includes a driving roller 17, a driven roller 18, an intermediate transfer belt 19, and a plurality (four) of primary transfer rollers 20.

  The driving roller 17 and the driven roller 18 are arranged to face each other with a space in the front-rear direction.

  The intermediate transfer belt 19 is stretched around the driving roller 17 and the driven roller 18 so that the lower portion thereof is in contact with all the photosensitive drums 9. Further, the intermediate transfer belt 19 is moved in a circular motion so that the lower portion thereof is moved from the front side toward the rear side by the driving of the driving roller 17 and the driven of the driven roller 18.

  The primary transfer roller 20 is disposed opposite to the corresponding photosensitive drum 9 with the lower portion of the intermediate transfer belt 19 interposed therebetween.

  The secondary transfer roller 16 is disposed behind the belt unit 15. The secondary transfer roller 16 is opposed to the driving roller 17 of the belt unit 15 with the intermediate transfer belt 19 interposed therebetween.

  The fixing unit 8 is disposed on the upper side of the secondary transfer roller 16 and includes a heating roller 21 and a pressure roller 22 facing the heating roller 21.

  The toner in the developing cartridge 12 is frictionally charged between the developing roller 13 and the supply roller 14 and is carried on the surface of the developing roller 13 as a thin layer having a constant thickness.

  On the other hand, the surface of the photosensitive drum 9 is uniformly positively charged by a charger (not shown) as the photosensitive drum 9 rotates, and then exposed by an exposure unit (not shown). As a result, an electrostatic latent image corresponding to the image to be formed on the paper P is formed on the surface of the photosensitive drum 9.

  When the photosensitive drum 9 further rotates, the toner carried on the surface of the developing roller 13 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 9. As a result, the electrostatic latent image on the photosensitive drum 9 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 9.

  The toner image carried on the surface of the photosensitive drum 9 is sequentially primary-transferred sequentially to the lower portion of the intermediate transfer belt 19 that is moved from the front side to the rear side. As a result, a color image is formed on the intermediate transfer belt 19.

  In addition, the paper P stored in the paper feed tray 5 is conveyed by various rollers so as to make a U-turn to the rear upper side, and the intermediate transfer belt 19 and the secondary transfer roller 16 one by one at a predetermined timing. Paper is fed between. The color image formed on the intermediate transfer belt 19 is secondarily transferred to the paper P when the paper P passes between the intermediate transfer belt 19 and the secondary transfer roller 16.

  The color image transferred onto the paper P is heat-fixed on the paper P by being heated and pressed in the fixing unit 8 while the paper P passes between the heating roller 21 and the pressure roller 22. Is done.

The paper P on which the toner image has been fixed in the fixing unit 8 is discharged onto a paper discharge tray 23 formed on the upper surface of the main body casing 2.
2. Drawer Unit (1) Drawer Frame The drawer frame 11 includes a frame main body 31 and a linear motion cam 32 as shown in FIGS.
(1-1) Frame Main Body The frame main body 31 includes a frame 33 and a lock member 34 as an example of a fixing member, as shown in FIG.

  The frame 33 is formed in a bottomed frame shape having a substantially rectangular shape in plan view. A cartridge guide groove 35, a linear cam insertion hole 36, and an arm support boss 37 are formed in the frame 33.

  Four cartridge guide grooves 35 are provided at the upper end portions of the left and right side walls of the frame body 33 at intervals in the front-rear direction. The cartridge guide groove 35 is formed in a substantially U shape in side view so as to be cut out downward from the upper end edge of the left and right side wall of the frame 33.

  The linear cam insertion holes 36 are respectively provided at the lower ends of the front and rear side walls of the frame 33. One linear cam insertion hole 36 is provided at the left end and the right end at the lower end of the side wall in the front-rear direction of the frame 33. The linear cam insertion hole 36 is formed in a substantially rectangular shape when viewed from the front.

  One arm support boss 37 is provided at each of the front end portions of the left and right side walls of the frame 33. The arm support boss 37 is formed in a substantially cylindrical shape extending from the left and right outer surface of the left and right side wall of the frame 33 toward the outer side in the left and right direction.

  The lock member 34 is provided at the front end of the frame body 31. The lock member 34 includes a pair of left and right arms 38 and an engagement shaft 39.

  Each of the pair of arms 38 is disposed to face each other with a space in the left-right direction. The arm 38 is formed in a flat plate shape that is substantially rectangular in side view and extends in the front-rear direction. A support boss insertion hole 40 and an engagement shaft insertion hole 41 are formed in the arm 38.

  The support boss insertion hole 40 is formed in a substantially circular shape in a side view at the rear end portion of the arm 38. The diameter of the support boss insertion hole 40 is substantially the same as the outer diameter of the arm support boss 37. The support boss insertion hole 40 is fitted to the corresponding arm support boss 37 so as to be rotatable from the outside in the radial direction.

  The engagement shaft insertion hole 41 is formed through the front end portion of the arm 38 in a substantially circular shape when viewed from the side. The diameter of the engagement shaft insertion hole 41 is substantially the same as the outer diameter of the engagement shaft 39.

  The engagement shaft 39 is formed in a substantially cylindrical shape extending in the left-right direction. Both end portions in the left-right direction of the engagement shaft 39 are fitted in the engagement shaft insertion holes 41 of the corresponding arm 38 so as to penetrate the corresponding arm 38.

The lock member 34 has the arm support boss 37 as a fulcrum and a fixed position where the arm 38 extends horizontally in the front-rear direction (FIG. 8B), and a fixed release position where the arm 38 extends so as to incline upward toward the front side (Fig. 8 (a)).
(1-2) Linear Motion Cam The linear motion cam 32 is formed in a substantially rectangular frame shape in plan view with the rear side opened as shown in FIGS. 3 (a) and 3 (b). The linear cam 32 is integrally provided with a cam portion 51 as an example of a pair of left and right contact / separation members and an operation portion 52.

  Each of the pair of cam portions 51 is opposed to each other with a space in the left-right direction. The cam portion 51 is formed in a substantially prismatic shape extending in the front-rear direction. The cam portion 51 includes a plurality of (four) displacement portions 53, a rack portion 54, and a locked portion 55.

  The plurality of displacement portions 53 are continuously arranged in series in the front-rear direction so as to be partitioned by virtual lines in FIG. The upper end portion of the displacement portion 53 is formed in a substantially staircase shape so as to descend stepwise from the front side toward the rear side. The upper surface of the displacement portion 53 has a first positioning surface 56, a first displacement surface 57, a second positioning surface 58, a second displacement surface 59, and a third positioning surface 60.

  The first positioning surface 56 is an upper surface of the front end portion of the displacement portion 53 and is formed as a horizontal plane extending in the front-rear direction.

  The first displacement surface 57 is formed as an inclined surface that is continuous with the rear end portion of the first positioning surface 56 and is inclined downward as it goes from the front side to the rear side.

  The second positioning surface 58 is formed as a horizontal plane extending in the front-rear direction continuously to the rear end portion of the first displacement surface 57.

  The second displacement surface 59 is formed as an inclined surface that is continuous with the rear end portion of the second positioning surface 58 and is inclined downward from the front side toward the rear side.

  The third positioning surface 60 is formed as a horizontal plane extending in the front-rear direction continuously to the rear end portion of the second displacement surface 59.

  Further, in the displacement portion 53 arranged on the foremost side, the length in the front-rear direction of the first positioning surface 56 is set longer than that in the other displacement portions 53, and accordingly, the front-rear direction of the second positioning surface 58 is set accordingly. The length is set short.

  The rack portion 54 is formed in a substantially prismatic shape extending continuously from the rear end portion of the rearmost displacement portion 53 to the rear side. Gear teeth are formed at the upper end of the rack portion 54.

  The locked portion 55 is formed in a substantially prismatic shape extending continuously from the front end portion of the foremost displacement portion 53 to the front side. A lock member engagement groove 61 is formed in the locked portion 55.

  The locking member engagement groove 61 is formed as a concave groove having a substantially U shape in a side view with the upper side opened so that the rear end portion of the locked portion 55 is cut out from the upper end portion toward the lower side. ing.

  The operation part 52 is installed between the front end parts of the pair of cam parts 51. The operation unit 52 is formed in a substantially prismatic shape extending in the left-right direction. A handle 62 is formed on the operation unit 52.

  The handle 62 is formed in a substantially rectangular frame shape in plan view so as to protrude from the front end portion to the front side at the substantially center in the left-right direction of the operation portion 52.

  The linear cam 32 is supported by the frame 33 such that the pair of cam portions 51 are inserted through the corresponding linear cam insertion holes 36.

  Specifically, the left cam portion 51 is inserted into the left-hand linear cam insertion hole 36 so that the rack portion 54 protrudes rearward from the frame body 33, and is inserted into the left lower end portion of the frame body 33 in the front-rear direction. It is arranged to be slidable.

  The right cam portion 51 is inserted into the right linear cam insertion hole 36 so that the rack portion 54 protrudes rearward from the frame body 33, and is inserted into the right lower end portion of the frame body 33 in the front-rear direction. It is arranged to be slidable.

Thereby, the linear cam 32 is supported by the lower end part of the frame 33 so that it can slide to the front-back direction.
(2) Developing Cartridge As shown in FIGS. 2 and 4, the developing cartridge 12 includes a developing frame 71 as an example of a frame and a pressing member 72.

  The developing frame 71 is formed in a substantially box shape that is long in the left-right direction. In the developing frame, an exposure opening 73 (see FIG. 2), a developing roller shaft support hole 74, and a pressing member accommodating portion 75 are formed.

  The exposure opening 73 is formed through the upper wall of the developing frame 71 in a substantially rectangular shape in plan view extending along the left-right direction (see FIG. 2). The exposure opening 73 exposes the upper end portion of the developing roller 13 (see FIG. 2).

  The developing roller shaft support holes 74 are formed one by one at the upper ends of the left and right side walls of the developing frame 71. The developing roller shaft support hole 74 is formed in a substantially circular shape when viewed from the side. Each of the left and right developing roller shaft support holes 74 can be rotated such that both ends in the left and right direction of the rotating shaft of the developing roller 11 (hereinafter referred to as developing roller shaft 70) protrude outward in the left and right direction. It is supported by.

  One pressing member accommodating portion 75 is provided at each of the left and right end portions of the lower wall of the developing frame 71. The pressing member accommodating portion 75 is formed in a substantially prismatic shape extending downward from the lower wall of the developing frame 71.

  As shown in FIG. 5, the pressing member 72 includes a pressing member main body 76 as an example of a contact member, and a compression spring 77 as an example of an urging member.

  The pressing member main body 76 is formed in a substantially rectangular tube shape with its lower end portion closed. A lower end portion of the pressing member main body 76 is formed in a substantially arc shape in a side view. The outer dimension of the pressing member main body 76 in the vertical direction is shorter than the inner dimension of the pressing member housing portion 75 in the vertical direction. Further, the outer dimension of the pressing member main body 76 in the left-right direction is shorter than the inner dimension of the pressing member housing portion 75 in the left-right direction. The pressing member main body 76 is accommodated in the pressing member accommodating portion 69 so as to be slidable in the vertical direction.

  The compression spring 77 is a compression coil spring that extends in the front-rear direction. The lower end portion of the compression spring 77 is in contact with the inner surface of the lower end portion of the pressing member main body 76 from above. The upper end portion of the compression spring 77 is in contact with the lower wall of the developing frame 71 from below in the pressing member accommodating portion 75. Thereby, the pressing member main body 76 is always urged downward by the urging force of the compression spring 77.

  The pressing member 72 is always arranged at a pressing release position (see FIG. 4B) where the pressing member main body 76 protrudes downward from the pressing member accommodating portion 75 by the urging force of the compression spring 77, and the compression spring The pressing member main body 76 is disposed at a pressing position where it is retracted into the pressing member accommodating portion 75 against the urging force of 77 (see FIG. 4A).

  As shown in FIG. 2, the developing cartridge 12 is arranged in the drawer frame 11 so that the left and right ends of the developing roller shaft 70 are fitted in the corresponding cartridge guide grooves 35 of the frame 33. It is supported by.

At this time, the left and right pressing members 72 of the developing cartridge 12 are in contact with the left and right cam portions 51 from above.
3. Structure of Main Body Casing The main body casing 2 includes a front cover 4 as described above and shown in FIG.

  The front cover 4 is formed in a substantially flat plate shape extending in the left-right direction. The front cover 4 includes a lock release cam 83 as an example of a fixing release member.

  One unlock cam 83 is disposed at each of the left and right ends of the front cover 4. The unlocking cam 83 is formed in a substantially rectangular flat plate shape when viewed from the side so as to protrude rearward from the rear surface of the front cover 4 at the substantially center in the vertical direction when the front cover 4 is disposed at the closed position. Yes. The rear end edge 84 of the unlocking cam 83 is inclined forward as it goes upward.

  The engagement shaft 39 of the lock member 34 is engaged with the upper end portion of the rear end edge 84 of the lock release cam 83 in a state where the front cover 4 is disposed at the closed position. Thereby, the lock member 34 is arrange | positioned in the fixed release position.

  Further, a linear cam drive gear 81 is provided in the main body casing 2.

  The linear cam drive gear 81 is disposed on the rear side of the drawer unit 10 at the substantially vertical center of the rear end portion of the main body casing 2. Two linear cam drive gears 81 are provided in the left-right direction at intervals. The linear cam drive gear 81 is formed in a substantially disc shape having a thickness in the left-right direction, and gear teeth are formed on the entire outer peripheral surface thereof.

  Each of the two linear cam drive gears 81 is supported so as not to rotate relative to each of both ends in the left-right direction of one drive shaft 82 extending in the left-right direction. The drive shaft 82 is connected to a drive source (not shown) in the main body casing 2 so as to be able to transmit the drive.

Each of the two linear cam drive gears 81 meshes with each of the rack portions 54 of the left and right cam portions 51 when the drawer frame 11 is housed in the inner position.
4). Image Forming Operation In this printer 1, in the above-described image forming operation, it is possible to switch between a color printing mode for forming a color image, a monochrome printing mode for forming a monochrome image, and a print standby mode for preparing for image formation. .
(1) Color printing mode When forming a color image, the printer 1 is set to the color printing mode.

  In order to change the printer 1 to the color printing mode, as shown in FIG. 6A, the linear cam driving gear 81 is rotated counterclockwise as viewed from the right side, and the operation unit 52 is placed on the front surface of the frame 33. The linear cam 32 is moved rearward until it comes into contact.

  Then, the linear cam 32 is disposed at the first position where the cam portion 51 is pushed to the rearmost side (see FIG. 3A).

  When the linear cams 32 are arranged at the first position, the pressing members 72 of all the developing cartridges 13 are brought into contact with the corresponding first positioning surfaces 56 of the cam portions 51 from above.

  As a result, the developing rollers 13 of all the developing cartridges 12 are brought into contact with the corresponding photosensitive drums 9 from below. That is, the plurality of developing cartridges 11 are arranged at the first contact position.

  Further, the pressing member main bodies 76 of all the developing cartridges 12 are arranged at the pressing positions against the urging force of the compression springs 77. As a result, the developing rollers 13 of all the developing cartridges 12 are brought into elastic contact with the corresponding photosensitive drums 9 by the urging force of the compression springs 77.

As a result, the printer 1 enters the color printing mode.
(2) Monochrome printing mode When a monochrome image is formed, the printer 1 is set to the monochrome printing mode.

  In order to change the printer 1 to the monochrome printing mode, as shown in FIG. 6B, the linear cam 32 is rotated clockwise in the right side view from the state of the color printing mode, and the linear cam 32 is moved. Is moved from the first position to the front side.

  Then, the linear motion cam 32 is disposed at the second position, and the pressing members 72 of the developing cartridges 12 other than black are respectively guided by the inclination of the corresponding first displacement surface 57 of the cam portion 51, and the corresponding second It abuts on the positioning surface 58 from above. At this time, the pressing member 72 of the black developing cartridge 12 is in contact with the front end portion of the corresponding first positioning surface 56 of the cam portion 51 from above.

  As a result, the developing rollers 13 of the developing cartridges 12 other than black are separated from the corresponding photosensitive drums 9 downward. Further, the developing roller 13 of the black developing cartridge 12 is in contact with the corresponding photosensitive drum 9 from below. That is, the plurality of developing cartridges 11 are arranged at the second contact position.

  Further, the pressing member main body 76 of the developing cartridge 12 other than black is arranged at the pressing release position by the urging force of the compression spring 77. The pressing member main body 76 of the black developing cartridge 12 is disposed at the pressing position against the urging force of the compression spring 77. As a result, the developing roller 13 of the black developing cartridge 12 is elastically brought into contact with the corresponding photosensitive drum 9 by the urging force of the compression spring 77.

As a result, the printer 1 enters the monochrome printing mode.
(3) Print standby mode When preparing for image formation without forming either a color image or a monochrome image, the printer 1 is set to the print standby mode.

  In order to change the printer 1 to the print standby mode, as shown in FIG. 7A, from the state of the monochrome print mode, the linear cam drive gear 81 is rotated clockwise as viewed from the right side, and the linear cam 32 is moved. Is moved from the second position to the front side.

  Then, the linear motion cam 32 is arranged at the third position, and the pressing member 72 of the black developing cartridge 12 is guided by the inclination of the corresponding first displacement surface 57 of the cam portion 51, and the corresponding second positioning surface 58. From above. At this time, the pressing members 72 of the developing cartridges 12 other than black are in contact with the front end portions of the corresponding second positioning surfaces 58 of the cam portions 51 from above.

  As a result, the developing rollers 13 of all the developing cartridges 12 are spaced apart from the corresponding photosensitive drums 9 respectively. That is, the plurality of developing cartridges 11 are arranged at the first separation position. At this time, the upper end portions of the developing rollers 13 of all the developing cartridges 12 are disposed at substantially the same position as the upper end portion of the drawer frame 11 (see FIG. 10A).

  Further, the pressing member main bodies 76 of all the developing cartridges 12 are arranged at the pressing release position by the urging force of the compression spring 77.

As a result, the printer 1 enters the print standby mode.
5. Printer Maintenance Work (1) Development Cartridge Replacement Work When the toner in any one of the development cartridges 12 is consumed in the above-described image forming operation, the printer 1 replaces the development cartridge 12 with an exchange mode. Can be switched to.

  In order to change the printer 1 to the replacement mode, as shown in FIG. 7B, the linear motion cam 32 is rotated clockwise in the right side view from the print standby mode, and the linear motion cam 32 is moved. , Move from the third position to the front side.

  Then, the linear cam 32 is disposed at the fourth position, and the pressing members 72 of all the developing cartridges 12 are respectively guided by the inclination of the corresponding second displacement surface 59 of the cam portion 51 to correspond to the corresponding third positioning position. It abuts on the surface 60 from above.

  As a result, all the developing cartridges 12 are moved downward so as to be further away from the photosensitive drum 9 than in the print standby mode. That is, the plurality of developing cartridges 12 are disposed at the second separation position.

  Then, as shown in FIG. 8A, the developing rollers 13 of all the developing cartridges 12 are accommodated in the drawer frame 11 so that the upper end portion is disposed below the upper end portion of the drawer frame 11. Is done.

  At this time, the linear cam 32 is moved to the front side until the engagement shaft 39 of the lock member 34 can be engaged in the lock member engagement groove 61 (see FIG. 8B).

  As a result, the printer 1 enters the replacement mode.

  In order to replace the developing cartridge 12, first, the front cover 4 is swung from the closed position to the open position, and the main body opening 24 is opened.

  Then, as the front cover 4 swings, the lock release cam 83 is separated from the engagement shaft 39 of the lock member 34 to the front side.

  Then, as shown in FIG. 8 (b), the lock member 34 rotates counterclockwise as viewed from the right side from the fixed release position due to its own weight, and the engagement shaft 39 enters the lock member engagement groove 61. Engaged from above. That is, in conjunction with the movement of the front cover 4 from the closed position to the open position, the lock member 34 is disposed at the fixed position.

  Thereby, the linear cam 32 is fixed to the fourth position by the engagement with the lock member 34. Then, the plurality of developing cartridges 12 are maintained at the second separated position.

  Next, in order to replace the developing cartridge 12, the handle 62 is gripped and the drawer unit 10 is pulled out from the main body casing 2 to the front side.

  Then, as shown in FIG. 9, the drawer unit 10 is arrange | positioned in an outer side position.

  Thereafter, in order to replace the developing cartridge 12, the developing cartridge 12 that has consumed the toner is detached so as to be pulled out from the drawer unit 10, and a new developing cartridge 12 is attached to the drawer unit 10 instead.

  Then, the drawer unit 10 is pushed into the main casing 2 and accommodated in the inner position, and the front cover 4 is moved from the open position to the closed position.

  Then, the rear end edge 84 of the lock release cam 83 of the front cover 4 is brought into contact with both end portions in the left and right direction of the engagement shaft 39 of the lock member 34 from the front side.

  When the front cover 4 is further moved from the open position to the closed position, the engagement shaft 39 is pressed upward by the inclination of the rear end edge 84 of the lock release cam 83, and the lock member 34 supports the arm support boss 37 as a fulcrum. As shown in FIG.

  Then, the engagement shaft 39 of the lock member 34 is disengaged upward from the lock member engagement groove 61.

  As a result, the fixing of the linear cam 32 to the fourth position is released, and the linear cam 32 can slide.

  When the front cover 4 is disposed at the closed position, the engagement shaft 39 of the lock member 34 is engaged with the upper end portion of the rear end edge 84 of the lock release cam 83, and the lock member 34 is disposed at the fixed release position. Is done.

Thereby, the replacement operation of the developing cartridge 12 is completed.
(2) Pulling out drawer unit in modes other than replacement mode In the image forming operation described above, the drawer unit 10 may be pulled out from the main casing 2 in a state where the printer 1 is not switched to the replacement mode.

  For example, as shown in FIG. 10A, in order to pull out the drawer unit 10 from the main body casing 2 while the printer 1 is switched to the print standby mode, first, the front cover 4 is moved from the closed position to the open position. The main body opening 24 is opened by swinging.

  Then, as the front cover 4 swings, the lock release cam 83 is separated from the engagement shaft 39 of the lock member 34 to the front side.

  Then, as shown in FIG. 10 (b), the lock member 34 is rotated counterclockwise as viewed from the right side from the fixed release position by its own weight.

  At this time, since the linear cam 32 is disposed at the third position, the engagement shaft 39 of the lock member 34 is not engaged in the lock member engagement groove 61, and the lock member engagement groove 61. Is brought into contact with the operation portion 52 of the linear cam 32 from above.

  Next, in order to pull out the drawer unit 10 from the main casing 2, the handle 62 is gripped and the linear cam 32 is pulled forward.

  Then, the linear cam 32 is moved from the third position to the front side and disposed at the fourth position.

  Then, as shown in FIG. 8B, the lock member 34 rotates counterclockwise as viewed from the right side due to its own weight, and the engagement shaft 39 engages in the lock member engagement groove 61 from above. Is done.

  Thereby, the linear cam 32 is fixed to the fourth position by the engagement with the lock member 34. Then, the plurality of developing cartridges 12 are maintained at the second separated position.

When the drawer unit 10 is further pulled out from the main body casing 2 to the front side, the drawer unit 10 is disposed at the outer position as shown in FIG.
6). Operation and Effect (1) According to the printer 1, as shown in FIGS. 6 and 7, when an image is formed in a state where the drawer frame 11 is arranged at the inner position (see FIG. 1) (color printing mode ( 6) and monochrome printing mode (see FIG. 6B)), the plurality of developing cartridges 12 are moved to the contact position (first contact position (see FIG. 6A)) and second contact position (see FIG. 6A). 6 (b))) and when waiting (print standby mode (see FIG. 7 (a))), the developing cartridge 12 is placed in the first separated position (see FIG. 7 (a)). Can do.

  Further, when the drawer frame 11 is moved to the outer position (see FIG. 9), the developing cartridge 12 can be arranged at a second separated position (see FIG. 7B) that is separated from the first separated position.

  As a result, in the monochrome printing mode and the print standby mode, the developing roller 13 can be retracted relatively small from the photosensitive drum 9 while the developing roller 13 is retracted relatively large from the photosensitive drum 9 when the drawer frame 11 is pulled out. Can be made.

  That is, the developing roller 13 can be separated from the photosensitive drum 9 by a necessary distance in each of the monochrome printing mode and the print standby mode and when the drawer frame 11 is pulled out.

As a result, it is possible to realize the separation between the developing roller 13 and the photosensitive drum 9 when the drawer frame 11 is pulled out and the separation between the developing roller 13 and the photosensitive drum 9 in the monochrome printing mode or the print standby mode with a simple configuration. Can do.
(2) According to the printer 1, as shown in FIG. 6, a color printing mode (see FIG. 6A) for printing a color image using the cam portion 51 of the linear cam 32, The printing mode of the printer 1 can be changed to a monochrome printing mode (see FIG. 6B) for printing a monochrome image.

Therefore, the print mode of the printer 1 can be changed with a simple configuration without providing a mechanism for changing the print mode of the printer 1 separately.
(3) Further, according to the printer 1, as shown in FIGS. 6 and 7, the moving direction of the cam portion 51 and the moving direction of the drawer frame 11 coincide with each other.

Therefore, compared with the case where the moving direction of the cam part 51 and the moving direction of the drawer frame 11 intersect, it is easier for the linear cam 32 to interfere with the drawer frame 11 when the drawer frame 11 is moved. Can be prevented.
(4) Further, according to the printer 1, the linear cam 32 may be provided on the drawer frame 11 as shown in FIG. 3.

  Therefore, when the drawer frame 11 is moved, the linear cam 32 can also be moved.

Therefore, it is possible to reliably prevent the linear motion cam 32 from interfering with the drawer frame 11 when the drawer frame 11 is moved.
(5) Also, according to the printer 1, as shown in FIG. 3, the cam portions 51 of the linear cam 32 are arranged on both sides of the developing cartridge 12 in the left-right direction.

  Therefore, each of the left and right cam portions 51 can act on each of the left and right end portions of the developing cartridge 12.

Therefore, in a state where the developing cartridge 12 is disposed at the contact position, the developing roller 13 can be stably brought into contact with the photosensitive drum 9 across both left and right end portions.
(6) Further, according to the printer 1, as shown in FIG. 6, when the developing cartridge 12 is disposed at the contact position, the developing roller 13 is moved by the urging force of the compression spring 77 (see FIG. 5). The photosensitive drum 9 is elastically contacted.

  Therefore, the developing roller 13 can follow the photosensitive drum 9 even when the photosensitive drum 9 and the developing roller 13 are driven during image formation.

As a result, the developing roller 13 can be stably brought into contact with the photosensitive drum 9 during image formation.
(7) Further, according to the printer 1, as shown in FIG. 8B, after the plurality of developing cartridges 12 are arranged at the second separation position, the drawer unit 10 is moved from the inner position to the outer position. be able to.

  Therefore, it is possible to prevent the drawer unit 10 from being moved from the inner position to the outer position before the plurality of developing cartridges 12 are disposed at the second separation position.

As a result, it is possible to reliably prevent the developing roller 13 from interfering with surrounding members when the drawer unit 10 is moved.
(8) According to the printer 1, as shown in FIG. 8B, the linear cam 32 is fixed to the fourth position where the developing cartridge 12 is positioned at the second separation position by the lock member 34. be able to.

  Therefore, when the drawer unit 10 is moved, it is possible to prevent the linear cam 32 from being moved from the fourth position.

As a result, when the drawer unit 10 is moved, it is possible to more reliably prevent the developing roller 13 from interfering with surrounding members.
(9) According to the printer 1, as shown in FIG. 8A, the fixing of the linear cam 32 to the fourth position can be released by using the closing operation of the front cover 4. .

Therefore, in the state where the front cover 4 is disposed at the closed position, the linear cam 32 can be reliably moved.
(10) Further, according to the printer 1, as shown in FIGS. 10B and 8B, the operation unit 52 is pulled forward so as to move the drawer unit 10 from the inner position to the outer position. Thus, the linear cam 32 can be moved to the fourth position.

Therefore, the plurality of developing cartridges 12 can be reliably arranged at the second separated position by using the operation of moving the drawer unit 10 from the inner position to the outer position.
(11) Also, according to the printer 1, as shown in FIG. 1, the plurality of developing cartridges 12 are in contact with the corresponding photosensitive drums 9 from below.

Therefore, the developing cartridge 12 can be easily lowered using gravity.
7). In the above-described embodiment, the front cover 4 and the linear motion cam 32 are moved to the fourth position in conjunction with the movement of the front cover 4 from the closed position to the open position. It can also be configured.

  According to this modification, the linear cam 32 can be moved to the third position using the opening operation of the front cover 4.

  Therefore, in a state where the front cover 4 is disposed at the open position, the plurality of developing cartridges 12 can be reliably disposed at the second separated position.

DESCRIPTION OF SYMBOLS 1 Printer 2 Main body casing 4 Front cover 9 Photosensitive drum 11 Drawer frame 12 Developing cartridge 13 Developing roller 24 Main body opening part 51 Cam part 52 Operation part 71 Developing frame 76 Pressing member main body 77 Compression spring 83 Lock release cam

Claims (12)

The device body;
A photoreceptor configured to carry an electrostatic latent image;
A developing cartridge having a developing roller facing the photoreceptor;
A support member configured to support the developing cartridge and movable to an inner position accommodated in the apparatus main body and an outer position moved from the inner position to the outside of the apparatus main body;
The developing cartridge includes a contact position where the developing roller comes into contact with the photosensitive member, a first separating position where the developing roller is separated from the photosensitive member, and the developing roller is separated from the photosensitive member in the first separating position. A second separation position that is further apart than the contact / separation member configured to move to a second separation position;
An image forming apparatus comprising: A plurality of the photoconductors are arranged in parallel at intervals,
A plurality of the developing cartridges are provided so as to correspond to the plurality of photosensitive members,
The contact position is
A first contact position at which all the developing rollers contact the corresponding photoconductor;
A second contact position at which a part of the developing roller comes into contact with the corresponding photosensitive member and the remaining developing roller is separated from the corresponding photosensitive member;
The image forming apparatus according to claim 1, further comprising: The image forming apparatus according to claim 1, wherein the contact / separation member is movable along a moving direction of the support member. The image forming apparatus according to claim 1, wherein the contact / separation member is provided on the support member. The image forming apparatus according to claim 1, wherein the contact / separation members are disposed on both sides in the longitudinal direction of the developing cartridge. The developing cartridge is
A frame for supporting the developing roller;
A contact member that contacts the contact / separation member;
An urging member interposed between the contact member and the frame;
When the developing cartridge is disposed at the contact position, the frame is urged toward the photosensitive member by the urging force of the urging member so that the developing roller is in contact with the photosensitive member. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. 7. The support member according to claim 1, wherein the support member is movable from the inner position to the outer position when the developing cartridge is disposed at the second separated position. The image forming apparatus described in 1. The support member is movable to a fixing position for fixing the contact / separation member at a position for positioning the developing cartridge at the second separation position, and a fixing release position for releasing the fixing of the contact / separation member. The image forming apparatus according to claim 1, further comprising: The apparatus main body is
An opening for passing the support member from the inner position to the outer position;
An open / close member movable to an open position for opening the opening and a closed position for closing the opening;
The image forming apparatus according to claim 8, wherein the opening / closing member includes a fixing release member that holds the fixing member at the fixing release position when the opening / closing member is disposed at the closed position. The contact / separation member moves the developing cartridge from the first separation position to the second separation position in conjunction with the movement of the opening / closing member from the closed position to the open position. Item 10. The image forming apparatus according to Item 9. The support member includes an operation unit that is operated when the support member is moved.
The operation unit is connected to the contact / separation member,
The contact / separation member moves the developing cartridge from the first separation position to the second separation position by operating the operation unit to move the support member from the inner position to the outer position. The image forming apparatus according to claim 1, wherein the image forming apparatus is an image forming apparatus. The developer cartridge is in contact with the photoconductor from below,
The image forming apparatus according to claim 1, wherein the support member is disposed to face a lower side of the photoconductor.

Images