JP2010079205A - Image forming apparatus and developing cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a detachable developing cartridge having an easy-to-hold grip member. <P>SOLUTION: The image forming apparatus includes: tension springs 37 that biases a handle 31 toward a second position (to the rear side), the handle 31 slidably provided on the upper end face 33 of a developing frame 20; and abutting members 39 arranged on the first position side (front side). By sliding the handle 31 to the first position against the biasing forces of the tension springs 37, the handle 31 presses the abutting members 39. Consequently, the developing frame 20 is biased toward the photoreceptor drum 18. By sliding the handle 31 to the second position with the pressing forces of the tension springs 37, the pressing force applied to the abutting members 39 by the handle 31 is released. Consequently, the developing frame 20 is released from being biased to the photoreceptor drum 18. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image forming apparatus such as a color printer, and a developing cartridge attached to the image forming apparatus.

  In an image forming apparatus such as an electrophotographic printer, a developing cartridge including a developing roller for supplying toner to the photosensitive drum can be attached to and detached from an image forming apparatus main body including a photosensitive drum on which an electrostatic latent image is formed. What is to be known.

  In order to press the developing roller against the photosensitive drum during image formation, it has been proposed to fix the developing cartridge to the image forming apparatus main body in a pressed state toward the photosensitive drum.

For example, a rotatable handle that presses the developer cartridge and a contact member that comes into contact with the handle are provided on the upper wall of the developer cartridge, and the handle is tilted by rotating it in the pressing direction from the pressed release position. It has been proposed that the developing cartridge is pressed toward the photosensitive drum by moving it to the pressing position and pushing down the contact member. (For example, refer to Patent Document 1).
JP 2007-322554 A

  However, in Patent Document 1, when the developing cartridge is mounted, the developing cartridge is pressed toward the photosensitive drum by rotating the handle so that the developing cartridge is tilted.

  For this reason, in order to remove the developing cartridge, the handle in the tilted state is rotated in the pressing release direction and is held after being raised, so that it may be difficult to hold the handle and to remove the developing cartridge.

  Accordingly, an object of the present invention is to provide a developing cartridge that can easily grip a gripping member and is easy to attach and detach.

  In order to achieve the above object, an invention according to claim 1 is an image forming apparatus having an apparatus main body and a plurality of photosensitive drums arranged in parallel, and the plurality of photosensitive drums with respect to the apparatus main body. A photoconductor unit configured to be slidable between an accommodation position and a pull-out position in a parallel direction of the photoconductor drums, and provided corresponding to each photoconductor drum, and the photoconductor unit is in the pull-out position A plurality of developing cartridges configured to be detachable from the photosensitive unit and an upper surface, and a unit for accommodating the photosensitive unit when the photosensitive unit is in the accommodating position Each of the developing cartridges is opposed to the upper surface of the unit housing portion and gradually moves from the housing position side in the sliding direction of the photosensitive unit toward the drawing position side. A housing having an end surface that is inclined so as to increase a distance from the surface, and an end surface of the housing that is provided between the end surface of the housing and the upper surface of the unit housing portion, and when the photosensitive unit is in the housing position. A gripping member configured to be slidable between one position and a second position when the photoconductor unit is in the pull-out position, and a first attachment for biasing the gripping member toward the second position. A biasing means and a first position side of the end face of the casing, and when the gripping member is in the first position, the casing receives the pressing force from the gripping member and directs the casing toward the photosensitive drum. And when the gripping member is in the second position, a second biasing means is provided that is in a position not receiving a pressing force from the gripping member.

  According to a second aspect of the present invention, in the first aspect of the present invention, the first position side end of the gripping member is formed with a protruding portion that protrudes toward the upper surface of the unit accommodating portion. It is characterized by having.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the end surface of the casing is formed with a notch at the first position side end, and the second urging force is provided. The means is arranged at both ends of the notch in the axial direction of the photosensitive drum.

  According to a fourth aspect of the present invention, in the invention according to any one of the first to third aspects, the gripping member extends along the sliding direction at both ends in the axial direction of the photosensitive drum and outwards. A protruding ridge is formed, and the ridge is slidably fitted to the end surface of the housing, and a direction orthogonal to the sliding direction as it goes from the second position side to the first position side. A guide groove is formed so as to increase the width of the guide.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the first position side end portion of the surface of the gripping member facing the end surface of the casing is provided. Further, an inclined portion is formed which is inclined so that an interval between the gripping member and the end face of the housing is increased toward the first position side.

  The invention according to claim 6 is the invention according to any one of claims 1 to 5, wherein the first urging means is provided on the second position side of the end surface of the casing. It is characterized by that.

  The invention according to claim 7 is a developing cartridge, wherein a housing having an end face on one end side, a developer carrying member rotatably supported on the other end side of the housing, and the housing And a gripping member configured to be slidable between a first position on one end side of the end face and a second position on the other end side of the end face, and the gripping member toward the second position side. A first urging member that urges; and provided at an end of the end surface on the first position side, when the gripping member is in the first position, the pressing member receives a pressing force from the gripping member to Urging in a direction from the gripping member toward the developer carrying member, and when the gripping member is in the second position, a second biasing member in a position not receiving a pressing force from the gripping member, When the gripping member is disposed at the first position, It is characterized in that is configured to be floating in a direction toward said developer carrying member from the gripping member by.

  According to an eighth aspect of the present invention, in the seventh aspect of the present invention, at the both ends in the axial direction of the developer carrier of the gripping member, the protrusions that extend along the sliding direction and project outward. The protrusion is slidably fitted to the end surface of the housing, and the width in the direction orthogonal to the sliding direction increases as it goes from the second position side to the first position side. As described above, a guide groove is formed.

  The invention according to claim 9 is the invention according to claim 7 or 8, wherein the first position side end portion of the surface of the gripping member facing the end surface of the housing has the first position. An inclined portion is formed so as to increase the distance between the gripping member and the end surface of the housing as it goes to the one position side.

  According to the first aspect of the present invention, when the developing cartridge is attached to the photoconductor unit when the photoconductor unit is in the pulled-out position, the gripping member disposed on the end surface of the housing is the first attached. It arrange | positions in a 2nd position with the urging | biasing force of a biasing means. At this time, the second urging means is in a position where it does not receive a pressing force from the gripping member.

  Next, when the photosensitive unit is slid from the pulling position to the housing position with respect to the apparatus main body, the gripping member interferes with the upper surface of the unit housing portion, and a pressing force toward the first position acts on the gripping member. . Therefore, the gripping member slides to the first position along the inclination of the end surface of the housing against the urging force of the first urging means. At this time, the gripping member is easily moved to the first position due to friction generated by sliding contact with the upper surface of the unit housing portion.

  When the photosensitive unit is positioned at the storage position, the gripping member is positioned at the first position against the biasing force of the first biasing means. Then, the second urging means receives a pressing force from the gripping member and urges the casing toward the photosensitive drum. As a result, when the photosensitive unit is in the storage position, it is possible to ensure a reliable press contact of the developing cartridge to the photosensitive drum.

  On the other hand, when the photoconductor unit is slid from the housing position to the pulled-out position with respect to the apparatus main body, interference between the upper surface of the unit housing portion and the gripping member is eliminated. A biasing force toward the second position acts. Therefore, the gripping member slides to the second position along the inclination of the end surface of the housing by the biasing force of the first biasing means.

  When the photoconductor unit is located at the drawing position, the gripping member is located at the second position by the urging force of the first urging means. Then, the second urging means is positioned at a position where it does not receive a pressing force from the gripping member. As a result, when the photosensitive unit is in the pulled-out position, it is possible to ensure reliable release of the pressure contact with respect to the photosensitive drum of the developing cartridge.

  Further, when the gripping member is positioned at the second position, the second urging means is positioned at a position where it does not receive the pressing force from the gripping member, so that the gripping member of each developing cartridge adjacent in the parallel direction is It arrange | positions at intervals corresponding to the space in which the 2nd biasing means is provided. Therefore, the developing cartridge can be easily detached by holding the holding member as it is. Further, since the gripping member is positioned higher when the gripping member is positioned at the second position than the first position, the gripping member can be further easily gripped.

  As described above, according to the first aspect of the present invention, when the photosensitive unit is in the storage position, it is possible to ensure a reliable pressure contact with the photosensitive drum of the developing cartridge, and the photosensitive unit is pulled out. When in the position, it is possible to ensure release of the pressure contact with respect to the photosensitive drum of the developing cartridge. Further, when the photosensitive unit is in the pulled-out position, the developing cartridge can be easily detached from the photosensitive unit by holding the holding member as it is.

  According to the second aspect of the present invention, the first position side end of the gripping member is formed with a protruding portion that protrudes toward the upper surface of the unit housing portion.

  Therefore, in the protruding portion, it is possible to achieve reliable sliding friction between the gripping member and the upper surface of the unit housing portion. Moreover, since the projecting portion is formed at the end on the first position side of the gripping member, when the gripping member is located at the first position, the second biasing means is not in contact with the second biasing means. Arranged upstream in the urging direction. Therefore, the pressing force from the second member can be reliably applied to the second urging member, and the pressing contact between the developing cartridge and the photosensitive drum can be achieved.

  According to the invention described in claim 3, the first urging means is disposed in the notch formed at the first position side end of the end surface of the housing.

  Therefore, when the photosensitive unit is slid from the pulled-out position to the storage position, the gripping member toward the first position can easily ride on the second urging means.

  In addition, the second urging means is disposed at both axial ends of the photosensitive drum at the notch.

  Therefore, the second urging means can urge the housing at both axial ends of the photosensitive drum. As a result, uniform and stable pressure contact of the developing cartridge with respect to the photosensitive drum can be achieved.

  According to the fourth aspect of the present invention, the protrusions are formed at both ends of the gripping member in the axial direction of the photosensitive drum, and the protrusions are formed along the end surface of the housing. The groove is slidably fitted.

  Therefore, reliable sliding between the first position and the second position of the gripping member can be achieved.

  And the guide groove is formed so that the width | variety of the direction orthogonal to the sliding direction may spread toward the 1st position from the 2nd position.

  Therefore, the protrusion of the gripping member is loosely fitted in the guide groove at the first position. Thereby, the holding member can elastically press the second urging member at the first position. As a result, the developing cartridge can be brought into pressure contact with the photosensitive drum with an appropriate pressing force.

  According to the fifth aspect of the present invention, the first position side end of the gripping member is formed with an inclined portion on the surface facing the end surface of the housing. And the inclination part inclines so that the space | interval of the end surface of a housing | casing and a holding member may increase as it goes to the 1st position side.

  For this reason, when the photosensitive unit is slid from the pulled-out position to the storage position, the gripping member toward the first position can more easily ride on the second urging means.

  As a result, the grip member can be slid to the first position more easily.

  According to the sixth aspect of the present invention, the first urging means is provided on the second position side of the end surface of the housing.

  Therefore, it is possible to constantly bias the gripping member toward the second position with a simple configuration.

  According to the seventh aspect of the present invention, the gripping member is always arranged at the second position by the urging force of the first urging means. When the gripping member is disposed at the second position, the second biasing means is at a position where it does not receive a pressing force from the gripping member.

  On the other hand, when the gripping member is slid from the second position to the first position against the biasing force of the first biasing means, in the first position, the second biasing means causes the pressing force from the gripping member. In response, the casing is urged in the direction from the gripping member toward the developer carrier.

  For this reason, if the developing cartridge is arranged in the second position when being attached to or detached from the apparatus main body of the image forming apparatus, and is arranged in the first position when forming an image, the developer carrying body is formed during image formation. In addition, it is possible to ensure reliable pressure contact with the photosensitive drum provided in the apparatus main body, and it is possible to ensure reliable release of pressure contact with respect to the photosensitive drum of the developer carrying member at the time of attachment / detachment. Furthermore, when attaching and detaching, the holding member can be easily held, and the developing cartridge can be easily detached from the apparatus main body.

  Further, when the gripping member is disposed at the first position, the gripping member is configured to be movable in a direction from the gripping member toward the developer carrying member with respect to the housing. Therefore, the grip member can elastically bias the housing in the first position. As a result, when mounted on the apparatus main body, the developer carrier can be pressed against the photosensitive drum with an appropriate pressing force.

  According to the invention described in claim 8, the ridges are formed at both ends in the axial direction of the developer carrier of the holding member, and the ridges are formed along the end surface of the housing. The guide groove is slidably fitted.

  Therefore, reliable sliding between the first position and the second position of the gripping member can be achieved.

  And the guide groove is formed so that the width | variety of the direction orthogonal to the sliding direction may spread toward the 1st position from the 2nd position.

  Therefore, the protrusion of the gripping member is loosely fitted in the guide groove at the first position. Thereby, the holding member can elastically bias the housing in the first position. As a result, when mounted on the apparatus main body, the developer carrier can be pressed against the photosensitive drum with an appropriate pressing force.

  According to the ninth aspect of the present invention, the inclined portion is formed on the surface facing the end surface of the housing at the first position side end of the gripping member. And the inclination part inclines so that the space | interval of the end surface of a housing | casing and a holding member may increase as it goes to the 1st position side.

  Therefore, the gripping member can easily ride on the second urging means when sliding from the second position to the first position.

  As a result, the gripping member can be easily slid to the first position.

1. 1 is a side sectional view showing an embodiment of a color laser printer (drum unit: accommodation position) as an example of an image forming apparatus of the present invention.

  2 is a side sectional view showing the color laser printer (drum unit: drawing position) shown in FIG.

The color laser printer 1 is a horizontal tandem color laser printer, and includes a paper feed unit 3 for feeding paper P in a main body casing 2 as an example of an image forming apparatus main body, and a paper feed. And an image forming unit 4 for forming an image on the sheet P.
(1) Main Body Casing The main body casing 2 is formed in a box shape having a substantially rectangular shape in side view for accommodating the image forming unit 4. Between the scanner unit 8 (described later) and the transfer unit 10 (described later), A unit accommodating portion 14 for accommodating a drum unit 12 (described later) is defined. Further, a front cover 5 is provided on one side wall of the main body casing 2 so as to communicate with the unit accommodating portion 14 and to attach and detach a drum unit 12 (described later).

In the following description, the side where the front cover 5 is provided (the right side in FIG. 1) is the front side, and the opposite side (the left side in FIG. 1) is the rear side. In addition, when the color laser 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 left side, and the back side is the right side.
(2) Paper Feed Unit The paper feed unit 3 includes a paper feed tray 6 that accommodates the paper P. The paper feed tray 6 is detachably attached to the bottom of the main casing 2. Above the front end of the paper feed tray 6, a paper feed roller 7 and a paper feed path (not shown) including a U-turn path are arranged.

The paper P stored in the paper feed tray 6 is fed one by one toward the paper feed path (not shown) by the rotation of the paper feed roller 7. Thereafter, the paper P is transported from a paper feed path (not shown) toward the image forming unit 4 (between a photosensitive drum 18 (described later) and a transport belt 24 (described later)).
(3) Image Forming Unit The image forming unit 4 includes a scanner unit 8, a process unit 9, a transfer unit 10, and a fixing unit 11.
(3-1) Scanner Unit The scanner unit 8 is disposed on the upper part of the main body casing 2. As indicated by a chain line, the scanner unit 8 emits laser beams based on image data toward four photosensitive drums 18 (described later) to expose the photosensitive drums 18 (described later).
(3-2) Process Unit The process unit 9 is disposed below the scanner unit 8 and above the paper feed unit 3, and corresponds to one drum unit 12 as an example of the photosensitive unit and each color. The four developing cartridges 13 are provided.

  The drum unit 12 is slidable in the front-rear direction with respect to the main casing 2, and is housed in the unit housing portion 14 (see FIG. 1) and pulled out from the unit housing portion 14 (see FIG. 2). And move on.

  The developing cartridge 13 is detachably attached to the drum unit 12 so as to be arranged in parallel along the front-rear direction. Specifically, a black developing cartridge 13K, a yellow developing cartridge 13Y, a magenta developing cartridge 13M, and a cyan developing cartridge 13C are sequentially arranged from the front side to the rear side.

  Note that the upper end portion of the unit accommodating portion 14 extends in the front-rear direction so as to abut on a handle 31 (described later) of the developing cartridge 13 at both left and right end portions thereof, thereby forming an upper surface of the unit accommodating portion 14. A rail portion 15 is provided.

The rail portion 15 extends from the front end of the foremost developing cartridge 13 (specifically, the black developing cartridge 13K) to the rear end of the rearmost developing cartridge 13 (specifically, the cyan developing cartridge 13C). The length in the front-rear direction is longer than the distance. Further, the front end portion is notched so as to incline upward as it goes forward.
(3-2-1) Drum Unit The drum unit 12 includes a pair of left and right side frames 16, a photosensitive drum 18 that is rotatably supported between the side frames 16, and a center frame 17 that is installed between the side frames 16. And a scorotron charger 19.

  Both side frames 16 are formed in a rectangular shape in a side view, and are opposed to each other with a gap in the left-right direction by beams extending between front end portions and between rear end portions.

  The photoconductor drums 18 are arranged along the left-right direction, and four photoconductor drums 18 are arranged in parallel along the front-rear direction so as to correspond to each color.

  The center frame 17 is formed in a substantially rectangular shape in a side view so as to have a rear end surface that is inclined upward as it goes forward, and four center frames 17 are arranged in parallel along the front-rear direction corresponding to each photosensitive drum 18. Has been.

The scorotron charger 19 is supported by the center frame 17 so as to be opposed to and spaced apart from the photosensitive drum 18 above and behind the photosensitive drum 18.
(3-2-2) Developing Cartridge The developing cartridge 13 is provided corresponding to each photosensitive drum 18, and each includes a developing frame 20 whose lower end facing the photosensitive drum 18 is opened, and a supply roller. (Not shown) includes a developing roller 21 as an example of a developer carrier and a layer thickness regulating blade (not shown).

The developing roller 21 is rotatably supported on the lower end portion of the developing frame 20 so as to be exposed from the lower end portion of the developing frame 20, and is disposed so as to contact the photosensitive drum 18. A supply roller (not shown) is arranged above the front side of the developing roller 20, and a layer thickness regulating blade (not shown) is arranged above the rear side of the developing roller 20, and the developing frame 20 above them. In the inner space, toner corresponding to each color is accommodated.
(3-2-3) Developing operation in the process section The toner in the developing cartridge 13 is supplied to a supply roller (not shown), and further supplied to the developing roller 20 for development with the supply roller (not shown). The roller 20 is triboelectrically charged to the positive polarity.

  The toner supplied to the developing roller 20 is regulated in thickness by a layer thickness regulating blade (not shown) as the developing roller 20 rotates, and is carried on the surface of the developing roller 20 as a thin layer having a constant thickness. The

  On the other hand, the surface of the photosensitive drum 18 is uniformly positively charged by the scorotron charger 17 as the photosensitive drum 18 rotates, and then the laser beam from the scanner unit 8 (see the broken line in FIG. 1). Exposure is performed by high-speed scanning. 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 18.

When the photosensitive drum 18 further rotates, the positively charged toner carried on the surface of the developing roller 20 is supplied to the electrostatic latent image formed on the surface of the photosensitive drum 18. As a result, the electrostatic latent image on the photosensitive drum 18 is visualized, and a toner image by reversal development is carried on the surface of the photosensitive drum 18.
(3-3) Transfer Unit The transfer unit 10 is disposed along the front-rear direction in the main body casing 2 above the paper feed unit 3 and below the process unit 9. The transfer unit 10 includes a drive roller 22, a driven roller 23, a conveyance belt 24, and a transfer roller 25.

  The driving roller 22 and the driven roller 23 are opposed to each other with an interval in the front-rear direction, and a conveyor belt 24 is wound around them.

  The transfer roller 25 is provided so as to face each photosensitive drum 18 with the conveyance belt 24 interposed therebetween.

Then, the paper P fed from the paper feeding unit 3 is sequentially passed by the transport belt 24 from the front side to the rear side through the transfer positions where the photosensitive drums 18 and the transfer rollers 25 face each other. Be transported. During the conveyance, the toner images of the respective colors carried on the respective photosensitive drums 18 are sequentially transferred onto the paper P, and a color image is formed.
(3-4) Fixing Unit The fixing unit 11 includes a heating roller 26 and a pressure roller 27 that faces the heating roller 26 and is disposed behind the transfer unit 10. In the transfer unit 10, the color image transferred to the paper P is thermally fixed to the paper P by being heated and pressed while the paper P passes between the heating roller 26 and the pressure roller 27. .
(4) Paper discharge The paper P on which the toner image has been fixed passes through a paper discharge path (not shown) consisting of a U-turn path and is conveyed toward the paper discharge roller 28, and the main body casing 2 is conveyed by the paper discharge roller 28. The paper is discharged onto a paper discharge tray 29 formed on the top surface.
2. 3 is a perspective view of the developing cartridge shown in FIG. 1, in which (a) shows a state where the gripping member is in the second position, and (b) shows a state where the gripping member is in the first position. Indicates.

  4A and 4B are right side cross-sectional views corresponding to FIG. 3, in which FIG. 4A shows a state where the gripping member is in the second position, and FIG. 4B shows a state where the gripping member is in the first position.

  As shown in FIG. 3A, the developing cartridge 13 includes a developing frame 20 and a handle 31 as an example of a gripping member.

  As described above, the developing frame 20 is formed in a box shape in which the opening 32 that exposes the developing roller 21 is formed at the lower end.

  The developing frame 20 has an upper end surface 33 as an example of an end surface at the upper end portion thereof. A spring support plate 34 and a flange plate 35 are provided at the upper end of the developing frame 20. Further, a notch 36 having a rectangular shape in side view is formed at the upper end of the developing frame 20 at the front end.

  In the state where the developing cartridge 13 is mounted on the drum unit 12, the upper end surface 33 has a flat shape as shown in FIG. 4A and is inclined downward toward the front.

  The spring support plate 34 protrudes obliquely upward and forward from the rear end edge of the upper end surface 33, and is formed across the entire left and right width of the upper end surface 33. In addition, on the front end surface of the spring support plate 34, tension springs 37 as an example of first urging means are disposed at both left and right ends.

  The tension spring 37 is a coil spring, and its rear end is fixed to the spring support plate 34.

  The flange plate 35 extends upward and obliquely forward from both ends of the upper end surface 33 in the left-right direction, and is further bent inward in the left-right direction. The flange plate 35 is formed from the rear end edge of the upper end surface 33 to the middle in the front-rear direction (before the notch 36). Moreover, the lower surface of the gutter plate 35 is inclined upward so that the thickness thereof becomes thinner toward the front in the portion bent inward in the left-right direction.

  The inner surface of the gutter plate 35 defines a guide groove 38 together with the upper end surface 33.

  The guide groove 38 is formed along the inclination direction of the upper end surface 33, and is formed such that the length (vertical groove width) in the direction orthogonal to the inclination direction of the upper end surface 33 becomes longer toward the front. ing.

  The notch 36 is notched in an L-shaped cross section from the upper end surface 33 toward the diagonally rearward direction. Further, a contact member 39 as an example of a second urging means is disposed at both left and right ends of the notch 36.

  Each contact member 39 includes a compression spring 41 and a spring accommodating cylinder portion 40 that covers the compression spring 41.

  The compression spring 41 is a coil spring, and its lower end is fixed to the upper end surface 33.

  The spring accommodating cylinder portion 40 is formed in a cylindrical shape in which an upper lid having an arcuate cross section is integrally formed. The spring accommodating cylinder portion 40 is covered with the compression spring 41 from the upper end portion of the compression spring 41 toward the lower end portion.

  And the compression spring 41 is always urging | biasing the spring accommodating cylinder part 40 toward diagonally upward.

  The handle 31 is formed in a substantially right triangular prism shape extending along the left-right direction.

  That is, the front end portion of the handle 31 is formed as a protruding portion 51 that protrudes diagonally upward. The rear end surface of the protruding portion 51 is inclined forward as it goes upward. The protrusion 51 is formed with a gripping hole 42 penetrating the protrusion 51 in the front-rear direction so as to extend in the left-right direction.

  Further, at both ends of the handle 31 in the left-right direction, ridges 52 that extend along the inclination direction of the upper end surface 33 and project outward in the left-right direction are formed (see FIG. 3B). Further, on the lower surface of the handle 31 facing the upper end surface 33, an inclined surface 53 is formed at the front end portion thereof so as to incline upward so that the distance from the upper end surface 33 is increased toward the front.

  When the protrusion 52 of the handle 31 is fitted into the guide groove 38 of the developing frame 20, the handle 31 is located above the upper end surface 33 of the developing cartridge 13 along the inclination direction of the upper end surface 33. It is slidably provided between a first position on the front side (see FIG. 4B) and a second position on the rear side (see FIG. 4A).

  Further, the front end portion of the tension spring 37 is connected to the rear end portion of the handle 31. Thereby, the handle 31 is always biased toward the second position side.

When the handle 31 is disposed at the first position against the urging force of the tension spring 37 (see FIG. 4B), the handle 31 contacts the contact member 39 on the inclined surface 53 and presses the contact member 39. To do. Also. When the handle 31 is disposed at the second position by the biasing force of the tension spring 37 (see FIG. 4A), the contact with the contact member 39 is released, and the pressure on the contact member 39 is released. Is done.
3. Mounting and Demounting Operation of Developer Cartridge To attach the developer cartridge 13 to the main casing 2, as shown in FIG. 2, first, the front cover 5 is opened, and the drum unit 12 is received from the unit receiving portion 14 of the main casing 2. Pull out to the pull-out position.

  Then, the grip 31 of each developing cartridge 13 is gripped and inserted into the position corresponding to each color of the drum unit 12 from above. Then, the insertion of the developing cartridge 13 into the drum unit 12 is elastically regulated by a regulating member (not shown) at a position where the developing roller 21 contacts the photosensitive drum 18. When the handle 31 is released, the developing cartridge 13 tilts forward due to its own weight and is supported by the front wall of the drum frame 12. Thereby, each developing cartridge 13 has its upper end surface 33 inclined gradually downward from the accommodation position side (rear side) in the sliding direction (front-rear direction) of the drum unit 12 toward the drawing position side (front side). Installed.

  At this time, the handle 31 of each developing cartridge 13 is disposed at the second position by the urging force of the tension spring 37, and the contact with the contact member 39 is released.

  Then, the drum unit 12 is pushed from the front to the rear, and is slid from the drawing position toward the accommodation position.

  Then, the rear side surface of the protruding portion 51 of the handle 21 of each developing cartridge 13 comes into contact with the front end portion of the rail portion 15 of the unit housing portion 14 (see FIG. 4A).

  Next, when the drum unit 12 is further pushed in from the front to the rear, the handle 31 receives a reaction from the rail portion 15 toward the front, thereby resisting the biasing force of the tension spring 37 while sliding on the rail portion 15. Then, it slides from the second position toward the first position, that is, obliquely downward and forward.

  At the same time, as the handle 31 slides, the inclined surface 53 of the handle 31 abuts against the abutting member 39 and further rides on the abutting member 39 (the upper lid of the compression spring 41) to resist the urging force of the compression spring 41. The contact member 39 is pressed.

  When the drum unit 12 is further pushed from the front toward the rear, the protruding portion 51 of the handle 31 enters under the rail portion 15 and comes into contact with the lower end edge of the rail portion 15 (see FIG. 4B). .

  At this time, the handle 31 is disposed at the first position and presses the contact member 39. The contact member 39 biases the developing frame 20 toward the photosensitive drum 18. As a result, the developing roller 21 is elastically pressed against the photosensitive drum 18.

  As shown in FIG. 1, when the drum unit 12 is pushed into the storage position, the handles 31 of the developing cartridges 13 are all arranged at the first position, and the developing rollers 21 are pressed against the corresponding photosensitive drums 18. The

  Thereby, the mounting of the developing cartridge 13 to the main casing 2 is completed.

  In order to remove the developing cartridge 13 from the main casing 2, first, the drum unit 12 in the storage position is pulled out forward.

  Then, in each developing cartridge 13, the contact between the handle 31 and the rail portion 15 is sequentially released, and the handle 31 slides from the first position to the second position by the urging force of the tension spring 37.

  As shown in FIG. 2, when the drum unit 12 is pulled out to the drawing position, the handle 31 of each developing cartridge 13 is disposed at the second position by the urging force of the tension spring 37.

  At this time, an interval corresponding to the contact member 39 is formed in front of each handle 31 between the adjacent developing cartridges 13.

  Next, a hand is put into the holding hole 42 from the interval with the adjacent developing cartridge 13, the handle 31 is held as it is, and the developing cartridge 13 is removed.

Thereby, the separation of the developing cartridge 13 from the main casing 2 is completed.
4). Operation and Effect (1) According to this color laser printer 1, as shown in FIG. 2, when the developing cartridge 13 is attached to the drum unit 12 when the drum unit 12 is in the drawing position, the upper end surface of the developing frame 20 The handle 31 disposed at 33 is disposed at the second position on the rear side by the biasing force of the tension spring 37. At this time, since the contact member 39 is disposed in the front cutout 36, the contact with the handle 31 is released and the pressing force from the handle 31 is not received.

  Next, when the drum unit 12 is slid to the main body casing 2 from the pulled-out position to the storage position, the handle 31 interferes with the rail portion 15, and a pressing force toward the first position acts on the handle 31. Therefore, the handle 31 slides to the first position along the inclination of the upper end surface 33 of the developing frame 20 against the urging force of the tension spring 37. At this time, the handle 31 moves to the first position by friction generated by sliding contact with the rail portion 15.

  As shown in FIG. 1, when the drum unit 12 is positioned at the storage position, the handle 31 is disposed at the first position on the front side against the urging force of the tension spring 37. Then, the handle 18 rides on the contact member 39, and the contact member 39 receives a pressing force from the handle 18 and urges the developing frame 20 toward the photosensitive drum 18. As a result, when the drum unit 12 is in the storage position, it is possible to ensure a reliable pressure contact of the developing cartridge 13 against the photosensitive drum 18.

  On the other hand, when the drum unit 12 is slid and moved with respect to the main body casing 2 from the housed position to the pulled-out position, interference between the rail portion 15 and the handle 31 is eliminated, and the handle 31 is moved to the second position by the tension spring 37. The urging force toward the side acts. Therefore, the handle 31 slides to the second position along the inclination of the upper end surface 33 of the developing frame 20 by the urging force of the tension spring 37.

  As shown in FIG. 2, when the drum unit 12 is positioned at the pulling position, the handle 31 is disposed at the second position by the urging force of the tension spring 37. Then, the contact member 39 is released from contact with the handle 31 and does not receive a pressing force from the handle 31. As a result, when the photosensitive unit 18 is in the pulled-out position, it is possible to ensure the reliable pressure release of the developing cartridge 13 with respect to the photosensitive drum 18.

  When the handle 31 is disposed at the second position on the rear side, a space in which the contact member 39 is provided is formed in front of the handle 31 of each adjacent developing cartridge 13. Therefore, the developing cartridge 13 can be easily detached by putting the hand into the holding hole 42 from the space and holding the handle 31 as it is. Moreover, since the handle 31 is located upward when the handle 31 is located at the second position rather than the first position, the handle 31 is further easily gripped.

In this way, when the drum unit 12 is in the storage position, it is possible to ensure a reliable pressure contact with the photosensitive drum 18 of the developing cartridge 13, and when the drum unit is in the drawing position, the photosensitive drum of the developing cartridge 13 is secured. 18 can be surely released from the pressure contact. Further, when the drum unit 12 is in the pulled-out position, the developing cartridge 13 can be easily detached from the drum unit 12 by holding the handle 31 as it is.
(2) Further, according to the color laser printer 1, as shown in FIG. 1, a protruding portion 51 that protrudes toward the rail portion 15 of the unit housing portion 14 is formed at the front end portion of the handle 31. .

Therefore, in the protruding portion 51, it is possible to achieve reliable rubbing between the handle 31 and the rail portion 15. Moreover, since the protruding portion 51 is formed at the front end portion of the handle 31, when the handle 31 is located at the first position, the urging direction upstream side of the abutting member 39 with respect to the abutting member 39. Placed in. Therefore, the pressing force from the handle 31 can be reliably applied to the contact member 39, and the pressing contact of the developing cartridge 13 to the photosensitive drum 18 can be achieved.
(3) According to the color laser printer 1, the tension spring 37 is disposed in the notch 36 formed at the front end of the upper end surface 33 of the developing frame 20.

  Therefore, when the drum unit 12 is slid from the pulled-out position to the storage position, the handle 31 heading toward the first position can easily ride on the contact member 39 (the upper cover of the compression spring 41).

  In addition, the abutting members 39 are disposed at both left and right ends of the notch 36.

Therefore, the contact member 39 can bias the developing frame 20 at both ends in the left-right direction. As a result, uniform and stable pressure contact of the developing cartridge 13 with respect to the photosensitive drum 18 can be achieved.
(4) According to the color laser printer 1, the protrusions 52 are formed on both ends in the left-right direction of the handle 31, and the protrusions 52 are formed along the upper end surface 33 of the developing frame 20. The guide groove 38 is slidably fitted.

  Therefore, a reliable slide between the first position and the second position of the handle 31 can be achieved.

  And the guide groove 38 is formed so that the width | variety of the up-down direction orthogonal to the sliding direction may spread toward the 1st position from the 2nd position.

Therefore, the protrusion 52 of the handle 31 is loosely fitted in the guide groove 38 at the first position. Thereby, the handle 31 can elastically press the contact member 39 in the first position. As a result, the developing cartridge 13 can be brought into pressure contact with the photosensitive drum 18 with an appropriate pressing force.
(5) According to the color laser printer 1, the inclined surface 53 is formed on the front end portion of the handle 31 on the surface facing the upper end surface 33 of the developing frame 20. The inclined surface 53 is inclined so that the distance between the upper end surface 33 of the developing frame 20 and the handle 31 increases toward the first position side.

  Therefore, when the photosensitive unit 18 is slid from the pulled-out position to the storage position, the handle 31 heading toward the first position can more easily ride on the contact member 39 (the upper cover of the compression spring 41). .

As a result, the handle 31 can be more easily slid to the first position.
(6) According to the color laser printer 1, the tension spring 37 is provided on the second position side of the upper end surface 33 of the developing frame 20.

  Therefore, the handle 31 can be constantly urged toward the second position with a simple configuration.

1 is a side sectional view showing an embodiment of a color laser printer (drum unit: accommodation position) as an example of an image forming apparatus of the present invention. It is a sectional side view which shows the color laser printer (drum unit: extraction position) shown in FIG. FIGS. 2A and 2B are perspective views of the developing cartridge illustrated in FIG. 1, in which FIG. 1A illustrates a state where the gripping member is in the second position, and FIG. 2B illustrates a state where the gripping member is in the first position. 4A and 4B are right side cross-sectional views corresponding to FIG. 3, in which FIG. 3A shows a state where the gripping member is in the second position, and FIG. 3B shows a state where the gripping member is in the first position.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Color laser printer 2 Main body casing 12 Drum unit 13 Developing cartridge 14 Unit accommodating part 18 Photosensitive drum 20 Developing frame 21 Developing roller 31 Handle 33 Upper end surface 36 Notch part 37 Tensile spring 38 Guide groove 39 Contact member 51 Projection part 52 Projection 53 Inclined part

Claims (9)

The device body;
A photosensitive unit having a plurality of photosensitive drums arranged in parallel and configured to be slidable between an accommodation position and a drawing position in a parallel direction of the plurality of photosensitive drums with respect to the apparatus main body; ,
A plurality of developing cartridges provided corresponding to each of the photosensitive drums and configured to be detachable from the photosensitive unit when the photosensitive unit is in the drawing position;
A unit housing portion for housing the photoconductor unit when the photoconductor unit is in the housing position.
Each of the developing cartridges
A housing having an end surface facing the upper surface of the unit housing portion and inclined so that the distance from the upper surface gradually increases from the housing position side in the sliding direction of the photoconductor unit toward the drawing position side; ,
A first position provided between the end surface of the casing and the upper surface of the unit housing portion, and a second position when the photoconductor unit is in the pull-out position. A gripping member configured to be slidable between, and
First biasing means for biasing the gripping member toward the second position;
Provided on the first position side of the end surface of the casing, and when the gripping member is in the first position, the casing is biased toward the photosensitive drum by receiving a pressing force from the gripping member. An image forming apparatus comprising: a second urging unit in a position not receiving a pressing force from the gripping member when the gripping member is in the second position.   2. The image forming apparatus according to claim 1, wherein a protruding portion that protrudes toward an upper surface of the unit housing portion is formed at an end portion on the first position side of the gripping member. The end surface of the housing is formed with a notch at the first position side end,
3. The image forming apparatus according to claim 1, wherein the second urging unit is disposed at both ends of the cutout portion in the axial direction of the photosensitive drum. 4. At both ends in the axial direction of the photosensitive drum of the gripping member, ridges extending along the sliding direction and protruding outward are formed,
The ridge is slidably fitted to the end surface of the housing, and the width in the direction orthogonal to the sliding direction increases as it goes from the second position side to the first position side. The image forming apparatus according to claim 1, wherein a groove is formed.   At the first position side end of the surface of the gripping member that faces the end surface of the housing, the distance between the gripping member and the end surface of the housing is increased toward the first position. The image forming apparatus according to claim 1, wherein an inclined portion that is inclined is formed.   The image forming apparatus according to claim 1, wherein the first urging unit is provided on the second position side of the end surface of the housing. A housing having an end face on one end side;
A developer carrying member rotatably supported on the other end of the housing;
A gripping member provided on the end surface of the housing and configured to be slidable between a first position on one end side of the end surface and a second position on the other end side of the end surface;
A first biasing member that biases the gripping member toward the second position;
Provided at the end of the end surface on the first position side, when the gripping member is in the first position, the casing is moved from the gripping member toward the developer carrier by receiving a pressing force from the gripping member. Urging in the direction, and when the gripping member is in the second position, the second biasing member in a position not receiving a pressing force from the gripping member,
The developing cartridge is configured to be movable in a direction from the gripping member toward the developer carrying member with respect to the housing when the gripping member is disposed at the first position. . At both ends of the gripping member in the axial direction of the developer carrier, ridges extending along the sliding direction and projecting outward are formed,
The ridge is slidably fitted to the end surface of the housing, and the width in the direction orthogonal to the sliding direction increases as it goes from the second position side to the first position side. The developing cartridge according to claim 7, wherein a groove is formed.   At the first position side end of the surface of the gripping member that faces the end surface of the housing, the distance between the gripping member and the end surface of the housing is increased toward the first position. The developing cartridge according to claim 7, wherein an inclined portion is formed to be inclined.

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