This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2011-098169 filed Apr. 26, 2011.
The present invention relates to a process cartridge and an image forming apparatus.
According to an aspect of the invention, there is provided a process cartridge including an image forming unit including an image carrier, a developing unit, and a cleaning unit, a container attachment unit, and a toner receiving unit. The image carrier carries a latent image formed by an exposure process and a toner image formed by developing the latent image with toner and transfers the toner image onto a transfer body. The developing unit forms the toner image on the image carrier by developing the latent image on the image carrier with the toner. The cleaning unit cleans the image carrier by removing the toner that remains on the image carrier after the toner image is transferred onto the transfer body. The container attachment unit is provided at a position separated from the image forming unit and to which a toner container is detachably attached, the toner container containing the toner to be supplied to the developing unit. The toner receiving unit extends in a space between the image forming unit and the container attachment unit and receives the toner removed from the image carrier by the cleaning unit.
An exemplary embodiment of the present invention will be described in detail based on the following figures, wherein:
An exemplary embodiment of the present invention will be described with reference to the drawings.
The image forming apparatus 1 illustrated in
The photoconductor 11 has a cylindrical surface, and rotates in a direction shown by arrow a around an axis of the cylindrical surface. The photoconductor 11 carries an electrostatic latent image and a toner image formed on the surface thereof. The charging device 12 charges the surface of the photoconductor 11. In the illustrated example, the charging device 12 is a charging roller that rotates while being in contact with the photoconductor 11. As another example, a non-contact corotron charging device may be used.
The exposure device 20 exposes the photoconductor 11 to light to form an electrostatic latent image on the photoconductor 11. The exposure device 20 scans the surface of the photoconductor 11, charged by the charging device 12, with a light beam Bm based on an image signal supplied from an external device. Thus, a latent image is formed on the surface of the photoconductor 11. The exposure device 20 scans the surface of the photoconductor 11 with the light beam Bm in an axial direction X in which the rotational axis of the photoconductor 11 extends.
The developing device 13 develops the latent image on the photoconductor 11 with toner, thereby forming a toner image on the photoconductor 11. The developing device 13 includes stirring members 132 and 133 for stirring developer including the toner and magnetic carrier and a developing roller 131 that transports the developer that has been stirred to the photoconductor 11.
The transferring device 40 is a roller that rotates while a sheet of paper is interposed between the photoconductor 11 and the roller. The transferring device 40 transfers the toner image on the photoconductor 11 onto the sheet of paper. The fixing device 50 fixes the toner image that has been transferred onto the sheet of paper from the photoconductor 11 to the sheet of paper. The fixing device 50 includes a heating roller 51 and a pressing roller 52, and heats and pressurizes the toner by causing the sheet of paper on which the toner image is formed in an unfixed state to pass between the heating roller 51 and the pressing roller 52.
The sheet-storing section 60 contains sheets of paper on which images may be formed. The sheet-storing section 60 includes three sheet containers 61, 62, and 63 for containing three types of sheets. Of the three sheet containers 61 to 63, the two sheet containers 62 and 63 disposed in a lower section may be pulled out by an operator in a forward direction F from the front surface of the image forming apparatus 1. The operator supplies sheets of paper to the sheet containers 62 and 63 and pushes the sheet containers 62 and 63 into the image forming apparatus 1 in a rearward direction B. Accordingly, images may be formed on the sheets of paper. The sheet container 61, which is the remaining one of the three sheet containers 61 to 63 that is disposed in an upper section, is externally exposed at the front side of the image forming apparatus 1 when a manual-feed door 81 provided at the front surface of the image forming apparatus 1 is opened in the forward direction F. In this state, sheets of paper are supplied to the sheet container 61.
The sheet-transporting device 30 transports each sheet of paper along a transporting path R that passes through a transfer position. The transfer position is a position at which the toner image is transferred onto the sheet of paper from the photoconductor 11, and is located between the photoconductor 11 and the transferring device 40. The sheet-transporting device 30 includes pickup rollers 31, separation rollers 32, registration rollers 33, output rollers 34, and reverse transport rollers 35. The pickup rollers 31 pick up the sheets of paper from the sheet containers 61 to 63. The separation rollers 32 separate the sheets of paper picked up by the pickup rollers 31 from each other. The registration rollers 33 feed each sheet of paper to the transferring device 40 in accordance with the time at which the toner image is formed on the photoconductor 11. The output rollers 34 output the sheet of paper to which the toner image is fixed by the fixing device 50 to the outside of the image forming apparatus 1. The sheet of paper output by the output rollers 34 is placed on an output table 83 provided in an upper section of the image forming apparatus 1. A part of the output sheet that protrudes from the output table 83 is placed on a door panel 82. The door panel 82 is a component that covers the front side and the top side of the image forming apparatus 1. When the door panel 82 is rotated in the forward direction F around a shaft 82a provided at the front side of the image forming apparatus 1, the internal mechanism of the image forming apparatus 1 is exposed. In the case where duplex printing is performed, the output rollers 34 rotate in the reverse direction after transporting the sheet of paper to an intermediate position, and transport the sheet of paper along a reverse transporting path R′. The reverse transport rollers 35 transport the sheet of paper along the reverse transporting path R′ to the registration rollers 33. Accordingly, an image is formed on a surface of the sheet of paper at the side opposite to the side at which an image is already formed.
In the image forming apparatus 1 according to the present exemplary embodiment, the sheets of paper are supplied from the front of the image forming apparatus 1. In the image forming apparatus 1, sheets of paper P are supplied to the sheet containers 61 to 63 from a position in front of the image forming apparatus 1 in the forward direction F, and are transported in a rear section of the image forming apparatus 1. More specifically, the sheets of paper P are transported upward along the transporting path R provided behind the photoconductor 11 in the rearward direction B. The sheets of paper P on which the images are formed are ejected in the forward direction F and stacked on the output table 83 in the upper section of the image forming apparatus 1. The operator supplies new sheets of paper to the image forming apparatus 1 and takes out the sheets of paper on which the images are formed while being at a position in front of the image forming apparatus 1 in the forward direction F. Therefore, the image forming apparatus 1 may be placed at a position where there is no large space at either side of the image forming apparatus 1 in the axial direction X. An image reading device may be provided above the image forming apparatus 1 with a space therebetween for allowing the sheets of paper to be taken out and allowing components to be replaced. As described below, processes of attaching and detaching a process cartridge CR and a toner container TC to/from the image forming apparatus 1 are also performed while the operator is at a position in front of the image forming apparatus 1 in the forward direction F.
The image forming apparatus 1 also includes a cleaning device 71, a collected-toner receiving box 72, a container attachment unit 73, a toner supplier 74, and a controller 1C.
The cleaning device 71 comes into contact with the photoconductor 11 and cleans the photoconductor 11 by removing the toner that remains on the photoconductor 11 after the toner image is transferred onto a sheet of paper. The cleaning device 71 is a plate-shaped blade that extends along the photoconductor 11. The collected-toner receiving box 72 contains the toner that is removed from the photoconductor 11 by the cleaning device 71. The toner container (toner cartridge) TC is detachably attached to the container attachment unit 73. The toner container TC contains the toner to be supplied to the developing device 13. When the toner runs out, the operator takes out the toner container TC and replaces it with a new toner container TC.
The toner supplier 74 supplies the toner contained in the toner container TC to the developing device 13. The toner supplier 74 includes a tube that extends from a position below the toner container TC to a position above the developing device 13 and a helical blade member 74a placed in the tube. The toner supplier 74 transports the toner from the toner container TC to the developing device 13 by rotating the blade member 74a. The controller 10 controls each part of the image forming apparatus 1.
The above-described toner-image forming unit 10, the cleaning device 71, the collected-toner receiving box 72, the container attachment unit 73, and the toner supplier 74 are provided in the process cartridge CR. The process cartridge CR is detachably attached to an apparatus body 1A of the image forming apparatus 1. The toner container TC is detachably attached to the process cartridge CR. Here, the direction in which the process cartridge CR is attached to the apparatus body 1A is referred to as an attachment direction J, and the direction opposite to the attachment direction J is referred to as a detachment direction K. The attachment direction J and the detachment direction K are generically referred to as an attachment-detachment direction JK. The process cartridge CR has a handle 76 to be grasped by the operator when the operator attaches or detaches the process cartridge CR to/from the apparatus body 1A. The detailed structure of the process cartridge CR will be described below.
Here, the process cartridge CR corresponds to an exemplary embodiment of the present invention, and the toner-image forming unit 10 corresponds to an example of an image forming unit according to an exemplary embodiment of the present invention. The photoconductor 11 corresponds to an example of an image carrier according to an exemplary embodiment of the present invention, and the exposure device 20 corresponds to an example of an exposure unit according to an exemplary embodiment of the present invention. The developing device 13 corresponds to an example of a developing unit according to an exemplary embodiment of the present invention, and the sheet-transporting device 30 corresponds to an example of a transporting unit according to an exemplary embodiment of the present invention. The cleaning device 71 corresponds to an example of a cleaning unit according to an exemplary embodiment of the present invention, and the collected-toner receiving box 72 corresponds to an example of a toner receiving unit according to an exemplary embodiment of the present invention.
The basic operation of the image forming apparatus 1 illustrated in
The developing device 13 forms a toner image by developing the electrostatic latent image on the photoconductor 11 with the toner. The toner is supplied to the developing device 13 from the toner container TC by the toner supplier 74. The photoconductor 11 rotates while carrying the toner image formed by the developing device 13.
The sheets of paper P contained in the sheet containers 61 to 63 are picked up by the pickup rollers 31 and are transported toward the transferring device 40 along the transporting path R by the separation rollers 32 and the registration rollers 33. Each sheet of paper P is fed toward the transferring device 40 by the registration rollers 33 in accordance with the time at which the toner image is formed on the photoconductor 11. The transferring device 40 applies a transferring bias voltage between the photoconductor 11 and the sheet of paper, so that the toner image on the photoconductor 11 is transferred onto the sheet of paper. The transferring device 40 transports the sheet of paper onto which the toner image has been transferred to the fixing device 50, where the toner image is fixed to the sheet of paper. Thus, an image is formed on the sheet of paper. The sheet of paper on which the image is formed is ejected onto the output table 83 by the output rollers 34.
After the transferring process is performed by the transferring device 40, the toner that remains on the photoconductor 11 is removed by the cleaning device 71. The toner removed from the photoconductor 11 by the cleaning device 71 is collected in the collected-toner receiving box 72.
Referring to
When the operator grasps and pulls the handle 76, the process cartridge CR is pulled out from the apparatus body 1A of the image forming apparatus 1 obliquely upward with respect to the forward direction F, that is, in the detachment direction K. In the case where the image reading device RD is disposed above the image forming apparatus 1, a space through which the sheets of paper may be taken out is provided between the image forming apparatus 1 and the image reading device RD. When the process cartridge CR is attached to or detached from the image forming apparatus 1, the process cartridge CR is moved through the space that is provided between the image forming apparatus 1 and the image reading device RD for allowing the sheets of paper to be taken out.
In
The process cartridge CR is a replaceable unit in which the toner-image forming unit 10, the cleaning device 71, the collected-toner receiving box 72, the container attachment unit 73, the toner supplier 74, and the handle 76 are formed as a unit. The toner-image forming unit 10 includes the photoconductor 11, the charging device 12, and the developing device 13. Therefore, in the image forming apparatus 1 (see
In the process cartridge CR illustrated in
Except for the collected-toner receiving box 72, the toner container TC and the toner-image forming unit 10 are the components that occupy the largest spaces in the process cartridge CR. Since the toner container TC and the toner-image forming unit 10 are separated from each other, a large space is provided between the toner container TC and the toner-image forming unit 10 without forming a projecting portion in the process cartridge CR. The collected-toner receiving box 72 extends over the space between the toner container TC and the toner-image forming unit 10. Therefore, compared to the case in which, for example, the toner container TC is disposed next to the toner-image forming unit and a collected-toner receiving box is arranged in a space between other components without forming a projecting portion in the process cartridge, the capacity of the collected-toner receiving box may be increased.
The collected-toner receiving box 72 becomes unusable when the toner cannot be fed into the collected-toner receiving box 72, that is, when the collected-toner receiving box 72 is full and the toner removed from the photoconductor 11 by the cleaning device 71 cannot be transported into the collected-toner receiving box 72. In this case, it is necessary to replace the process cartridge CR with a new one. Thus, the capacity of the collected-toner receiving box 72 is one of the factors that affect the life of the process cartridge CR. When the capacity of the collected-toner receiving box 72 is increased, the life of the process cartridge CR is increased accordingly.
In the process cartridge CR, the toner-image forming unit 10, the collected-toner receiving box 72, and the container attachment unit 73 are arranged in the attachment-detachment direction JK of the process cartridge CR. Therefore, when the process cartridge CR is attached to the apparatus body 1A (see
As illustrated in
In addition, as illustrated in
The collected-toner receiving box 72 includes an upper member 72a and a lower member 72b. The lower member 72b is a container-shaped member that is disposed below the upper member 72a and that is open at the top side. The lower member 72b has a function of supporting the entire structure of the process cartridge CR. The cleaning device 71 and the photoconductor 11 are attached to the lower member 72b. In addition, a fixed member 731 included in the container attachment unit 73 and the developing device 13 (see
The upper member 72a is a container-shaped member that is open at the bottom side. The upper member 72a is placed on the lower member 72b such that the upper member 72a functions as a lid. Thus, peripheral portions of the upper member 72a and the lower member 72b are placed on top of each other except for the area in which the cleaning device 71 is disposed. Thus, the space in which the toner may be contained is defined as illustrated in
The length L1 of the photoconductor 11 in the axial direction X corresponds to the sum of the width of the sheets of paper in the axial direction X, allowance for the displacement of the sheets of paper, and dimensions of bearings 11b. The length L2 of the collected-toner receiving box 72 in the axial direction X is set to a maximum length within the range in which the collected-toner receiving box 72 is capable of passing through the attachment opening 91 through which the photoconductor 11 passes when the process cartridge CR is attached to the image forming apparatus 1. In other words, the length L2 is substantially equal to the length L1 of the photoconductor 11. The length L3 of the container attachment unit 73 in the axial direction X is also substantially equal to the length L1 of the photoconductor 11.
Referring to
The scanning area of the light beam Bm extends in a fan-shape having a center (pivot) thereof in the exposure device 20, and the side of the scanning area near the exposure device 20 is shorter than the side thereof near the photoconductor 11. Therefore, in the area between the photoconductor 11 and the exposure device 20 in the direction in which the light beam Bm is emitted, that is, in the area in which the collected-toner receiving box 72 is disposed, spaces through which the light beam Bm does not pass are provided at both sides of the scanning area of the light beam Bm in the axial direction X. Since the collected-toner receiving box 72 includes the second receiving sections 722 that are placed in the spaces at both sides of the scanning area of the light beam Bm, the capacity of the collected-toner receiving box 72 is increased by the amounts corresponding to the capacities of the second receiving sections 722.
As illustrated in
A bottom wall 723 (see
In addition, as illustrated in
In the process cartridge CR illustrated in
The toner container TC illustrated in
The container attachment unit 73 will now be described with reference to the exploded view of
The fixed member 731 includes a container-guiding cut portion 731a that linearly extends to guide the projection TC4 on the toner container TC and an arc-shaped restraining-portion-guiding hole 731b that guides the restraining member 732 while holding the restraining member 732. The handle 76 is fixed to the fixed member 731.
The restraining member 732 has a cylindrical shape with closed ends and a peripheral surface that is partially cut out, and is rotatably retained by the fixed member 731. The toner container TC is placed in the restraining member 732. A projection 732b that is fitted to the restraining-portion-guiding hole 731b in the fixed member 731 is formed on a side surface of the cylindrical restraining member 732. An opening-closing piece 732a that opens or closes the container-guiding cut portion 731a in the fixed member 731 is provided at the side surface of the restraining member 732. A door engagement portion 732d that engages with the door TC3 of the toner container TC is provided on the peripheral surface of the restraining member 732.
The projection TC4 on the toner container TC is placed in the container-guiding cut portion 731a in the fixed member 731. In the state illustrated in
The restraining member 732 includes a retaining piece 732c that is engageable with a retaining portion 85 provided on the apparatus body 1A (see
When the operator rotates the restraining member 732 in the locked state illustrated in
The apparatus body 1A of the image forming apparatus 1 includes the attachment unit 90 to which the process cartridge CR is attached. The attachment unit 90 includes a hollow space that extends in the attachment direction J from a position in the upper section of the image forming apparatus 1 near the side thereof in the forward direction F to the transferring device 40. When the door panel 82 is opened, the attachment unit 90 of the image forming apparatus 1 is externally exposed. Each of the walls at both sides of the attachment unit 90 in the axial direction X has a guiding groove 92 that extends in the attachment-detachment direction JK. At each side of the attachment unit 90 in the image forming apparatus 1, the guiding groove 92 extends to the position where the bearing of the photoconductor 11 is disposed.
The attachment unit 90 in the apparatus body 1A also includes a blocking member 93 and a blocking-member driver 94 at each side thereof. The blocking member 93 blocks the guiding groove 92 at an intermediate position thereof. The blocking-member driver 94 moves the blocking member 93 in response to the opening-closing movement of the door panel 82. The blocking-member driver 94 is connected to the door panel 82 at one end thereof, and has a crank mechanism that converts a rotating movement of the door panel 82 into a movement in the forward direction F or the rearward direction B. In addition, the blocking-member driver 94 has a cam groove 94a that operates the blocking member 93 in response to the movement of the blocking-member driver 94. When the door panel 82 is closed, the blocking-member driver 94 moves in the rearward direction B, and the blocking member 93 is operated by the cam groove 94a in the blocking-member driver 94 so as to move to the position where the blocking member 93 blocks the guiding groove 92.
Three projections CR1, CR2, and CR3 that project in the axial direction X are provided on each side surface CRa of the process cartridge CR in the axial direction X.
In the process of attaching the process cartridge CR to the apparatus body 1A of the image forming apparatus 1, the operator grasps the handle 76 of the process cartridge CR with one hand and supports the process cartridge CR with the other hand at around the bottom walls 723 (see
In the state in which the entire body of the process cartridge CR is placed in the apparatus body 1A of the image forming apparatus 1, the first projection CR1 and the second projection CR2 on the process cartridge CR are placed in the guiding groove 92 at each side of the apparatus body 1A, and the position of the process cartridge CR is fixed. The first projection CR1 is in contact with the distal end portion of the guiding groove 92, and is stopped.
When the door panel 82 is closed, the blocking member 93 is moved to the position where the blocking member 93 blocks the guiding groove 92, owing to the movement of the blocking-member driver 94 and the engagement between the blocking member 93 and the cam groove 94a. At this time, the blocking member 93 comes into contact with the first projection CR1. Accordingly, the first projection CR1 is positioned by the guiding groove 92 and the blocking member 93 at three points shown by triangular marks. The blocking member 93 prevents the process cartridge CR that has been attached to the apparatus body 1A from being displaced. In addition, since the first projection CR1 is integrated with the bearing 11b (see
In the above-described exemplary embodiment, the toner-image forming unit 10 including the photoconductor 11, the charging device 12, and the developing device 13 is described as an example of an image forming unit according to an exemplary embodiment of the present invention. However, the present invention is not limited to this, and the image forming unit may further include, for example, a transferring device and a fixing device.
In addition, in the above-described exemplary embodiment, the collected-toner receiving box 72 including the upper member 72a and the lower member 72b is described as an example of a toner receiving box according to an exemplary embodiment of the present invention. However, the present invention is not limited to this, and the toner receiving box may include, for example, three or more components.
In addition, in the above-described exemplary embodiment, the photoconductor 11 having a cylindrical surface is described as an example of an image carrier according to an exemplary embodiment of the present invention. However, the present invention is not limited to this, and the image carrier may be, for example, belt-shaped.
In addition, in the above-described exemplary embodiment, a plate-shaped blade is described as an example of a cleaning device according to an exemplary embodiment of the present invention. However, the present invention is not limited to this, and the cleaning device may be, for example, a brush.
In addition, in the above-described exemplary embodiment, the structure in which the toner image on the photoconductor 11 is directly transferred onto a sheet of paper is described as an example of an image forming unit according to an exemplary embodiment of the present invention. However, the present invention is not limited to this, and the toner image on the image carrier may, for example, be transferred onto an intermediate transfer body and then indirectly transferred onto a sheet of paper.
In addition, in the above-described exemplary embodiment, a sheet of paper is described as an example of a transfer body according to an exemplary embodiment of the present invention. However, the present invention is not limited to this. The transfer body is not limited as long as the transfer body is a recording medium on which an image may be formed, and may be, for example, a resin sheet.
In addition, in the above-described exemplary embodiment, a monochrome printer is described as an example of an image forming apparatus. However, the image forming apparatus according to the present invention is not limited to this, and may instead be, for example, a color printer that forms color images.
In addition, in the above-described exemplary embodiment, a printer is described as an example of an image forming apparatus. However, the image forming apparatus according to the present invention is not limited to this, and may instead be, for example, a copy machine or a facsimile machine.
The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.
Number | Date | Country | Kind |
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2011-098169 | Apr 2011 | JP | national |