Developing cartridge and image forming apparatus

Abstract

To provide a developing cartridge that can increase the capacity of a toner storage unit, and an image forming apparatus.SOLUTION: A developing cartridge 60 is removably attached to a drum unit, and comprises: a developing roller 61; a frame 100; a positioning rib 200A that is located at one end in a first direction of an outer surface of the frame 100, and is in contact with the drum unit to determine the position, around a developing roller axis 61X, of the frame 100 relative to the drum unit; and a positioning rib 200B that is located at the other end in the first direction of the outer surface of the frame 100, and is in contact with the drum unit to determine the position, around the developing roller axis 61X, of the frame 100 relative to the drum unit. The frame 100 has a toner storage unit 110. The toner storage unit 110 has a projection 111 that is located between the positioning ribs 200A and 200B in the first direction and projects beyond the positioning ribs 200A and 200B, and that can store toner.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to a developing cartridge and an image forming apparatus. [Background technology]

[0002] Conventionally, a known developer cartridge includes a developer housing and a developer roller held in the developer housing, and is detachable from a drawer unit that includes a photosensitive drum (Patent Document 1). In this technology, a positioning rib protruding from the developer housing contacts the drawer unit, so that the position of the developer roller around the axis relative to the drawer unit is determined. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-248295 Summary of the Invention [Problem to be solved by the invention]

[0004] Incidentally, there is a demand for a developing cartridge with a large capacity toner storage section that stores toner. Therefore, it is desirable to be able to increase the volume of the toner storage section. [Means for solving the problem]

[0005] In the first disclosure of the present application, the developing cartridge is detachably attachable to a drum unit that includes a first photosensitive drum. The developing cartridge includes a developing roller, a frame, a first positioning rib, and a second positioning rib. The developing roller is rotatable about a developing roller axis extending in a first direction. The frame is positioned around the axis of the developing roller relative to the drum unit. The first positioning rib is located at one end of the outer surface of the frame in the first direction and protrudes from the outer surface of the frame to contact the drum unit and determine the position of the frame around the developing roller axis relative to the drum unit. The second positioning rib is located at the other end of the outer surface of the frame in the first direction and protrudes from the outer surface of the frame. The second positioning rib is a rib that contacts the drum unit to determine the position of the frame around the developing roller axis relative to the drum unit. The frame has a toner storage portion capable of storing toner. The toner storage portion has a protrusion. The protruding portion is located between the first positioning rib and the second positioning rib in the first direction and protrudes beyond the first positioning rib and the second positioning rib. The protruding portion is capable of containing toner.

[0006] According to the first disclosure, the toner storage section is located between the first positioning rib and the second positioning rib, and has a protruding portion that protrudes beyond the positioning rib and is capable of storing toner, thereby increasing the volume of the toner storage section.

[0007] In a second disclosure of the present application, in the developing cartridge of the first disclosure, the frame may have a first pressed portion and a second pressed portion. The first pressed portion is located at one end of the outer surface of the frame in the first direction, and is pressed by a pressing member of the drum unit. The second pressed portion is located at the other end of the outer surface of the frame in the first direction, and is pressed by the pressing member of the drum unit. The first positioning rib and the second positioning rib may be located between the first pressed portion and the second pressed portion in the first direction.

[0008] According to the second disclosure, by positioning the first positioning rib and the second positioning rib between the first pressed portion and the second pressed portion in the first direction, the first positioning rib and the second positioning rib are positioned farther from the end of the frame in the first direction than the first pressed portion and the second pressed portion, thereby making it possible to prevent damage to the first positioning rib and the second positioning rib.

[0009] In a third disclosure of the present application, in the developing cartridge of the first disclosure, the frame may have a wall that intersects with the first direction, and the first positioning rib and the second positioning rib may protrude along the wall.

[0010] According to the third disclosure, the first positioning rib and the second positioning rib protrude along the wall of the frame, thereby ensuring the strength of the first positioning rib and the second positioning rib.

[0011] In a fourth disclosure of the present application, in the developing cartridge of the first disclosure, the developing cartridge may be movable in a second direction intersecting the first direction with respect to the drum unit between a contact position and a separated position. The contact position is the position where the developing roller comes into contact with the first photosensitive drum. The separated position is a position where the developing roller is separated from the first photosensitive drum. The surface of the first positioning rib that contacts the drum unit may extend along the second direction. The surface of the second positioning rib that contacts the drum unit may extend along the second direction.

[0012] According to the fourth disclosure, the surface of the first positioning rib that contacts the drum unit extends along the second direction, and the surface of the second positioning rib that contacts the drum unit extends along the second direction, allowing the developer cartridge to move smoothly relative to the drum unit.

[0013] In a fifth disclosure of the present application, an image forming apparatus includes a drum unit and any one of the developing cartridges disclosed in the first to fourth disclosures. The drum unit further includes at least one second photosensitive drum aligned with the first photosensitive drum. [Effects of the Invention]

[0014] The volume of the toner storage section can be increased. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating a schematic configuration of an image forming apparatus. [Figure 2] FIG. 2 is a perspective view showing the drum unit and the developing cartridge. [Figure 3] FIG. 2 is a perspective view showing a developing cartridge. [Figure 4] FIG. 2 is a perspective view showing a developing cartridge. [Figure 5] 10A and 10B are cross-sectional views showing a state in which a pressed portion of a developing cartridge is pressed by a pressing member of a drum unit. [Figure 6] 10A and 10B are cross-sectional views showing a state in which a positioning rib of a developing cartridge is in contact with a roller of a drum unit. [Figure 7] FIG. 2 is a front view showing the developing cartridge. [Figure 8] 1A and 1B are side views showing a developing cartridge. DETAILED DESCRIPTION OF THE INVENTION

[0016] Next, an embodiment will be described. 1, the image forming apparatus 1 is a color printer capable of forming a color image on a sheet S such as paper. The image forming apparatus 1 includes a device main body 10, a cover 11, a sheet supply unit 20, and an image forming unit 30.

[0017] In the drawings referred to, the first direction (see FIG. 2), the third direction, and the fourth direction are indicated by an arrow and the other direction without an arrow. In the embodiment, the first direction corresponds to the left-right direction of the image forming apparatus 1.

[0018] The third direction is a direction that intersects with the first direction. In the embodiment, the third direction is perpendicular to the first direction. The first direction corresponds to the front-rear direction of the image forming apparatus 1. The fourth direction is a direction that intersects both the first direction and the third direction. In this embodiment, the fourth direction is perpendicular to both the first direction and the third direction. The fourth direction corresponds to the up-down direction of the image forming apparatus 1.

[0019] The device body 10 has an opening 10A. The cover 11 opens and closes the opening 10A. The cover 11 is movable relative to the device body 10 between a closed position shown by a solid line and an open position shown by a virtual line. Specifically, the cover 11 is rotatable relative to the device body 10 between the closed position and the open position. The closed position is a position where the opening 10A is closed. The open position is a position where the opening 10A is opened.

[0020] The sheet supply unit 20 includes a sheet tray 21 and a sheet supply mechanism 22. The sheet tray 21 stores sheets S. The sheet supply mechanism 22 includes a pickup roller 23, a separation roller 24, a separation pad 25, a conveyance roller 26, and a registration roller 27.

[0021] The pickup roller 23 feeds the sheet S from the sheet tray 21 . The separation roller 24 and the separation pad 25 separate the sheets S sent out by the pickup roller 23 into one sheet. The conveying roller 26 and the registration roller 27 convey the sheet S to the image forming unit 30 .

[0022] The image forming section 30 includes an exposure unit 40, a drum unit 50, four developing cartridges 60, a transfer unit 70, and a fixing unit 80. The exposure unit 40 includes a light source, a deflector, a lens, a mirror, etc. The exposure unit 40 emits a light beam as indicated by the dashed dotted line to expose the surface of the photosensitive drum 51.

[0023] The drum unit 50 includes four photosensitive drums 51 and four chargers 52 . A toner image is formed on the surface of the photosensitive drum 51. The photosensitive drums 51 are aligned with one another. Specifically, the four photosensitive drums 51 are aligned in the third direction. In other words, the four photosensitive drums 51 are aligned in the conveying direction of the sheet S. The charger 52 charges the surface of the photosensitive drum 51 .

[0024] Drum unit 50 is detachable from apparatus main body 10. Specifically, drum unit 50 is detachable from apparatus main body 10 through opening 10A when cover 11 is in the open position shown by the imaginary line.

[0025] The developing cartridge 60 contains toner and includes a developing roller 61. The developing roller 61 supplies toner to the photosensitive drum 51. The developing roller 61 is rotatable about a developing roller shaft 61X that extends in a first direction (see FIG. 2).

[0026] 2, the developing cartridge 60 is detachable from the drum unit 50. The developing cartridge 60, when attached to the drum unit 50, is detachable from the apparatus main body 10 together with the drum unit 50.

[0027] 1, the developer cartridge 60 is movable in the second direction relative to the drum unit 50 between a contact position indicated by a solid line and a separated position indicated by a virtual line. The contact position is a position where the developer roller 61 contacts the corresponding photosensitive drum 51. The separated position is a position where the developer roller 61 is separated from the corresponding photosensitive drum 51.

[0028] The second direction is a direction that intersects with the first direction. In the embodiment, the second direction is perpendicular to the first direction (see FIG. 2). The second direction intersects with both the third direction and the fourth direction. When moving from the contact position to the separated position, the developer cartridge 60 moves obliquely upward and forward. When moving from the separated position to the contact position, the developer cartridge 60 moves obliquely downward and rearward.

[0029] The transfer unit 70 includes a drive roller 71, a driven roller 72, an endless transfer belt 73, and four transfer rollers 74. The transfer belt 73 is stretched over a drive roller 71 and a driven roller 72. The outer surface of the transfer belt 73 contacts the photosensitive drum 51. The transfer roller 74 is disposed inside the transfer belt 73. The transfer roller 74 and the photosensitive drum 51 sandwich the transfer belt 73 therebetween.

[0030] The fixing unit 80 includes a heating roller 81 and a pressure roller 82 . The heating roller 81 heats the sheet S. The pressure roller 82 sandwiches the sheet S between itself and the heating roller 81 .

[0031] The charger 52 charges the surface of the photosensitive drum 51. The exposure unit 40 emits a light beam onto the surface of the charged photosensitive drum 51. As a result, an electrostatic latent image based on image data is formed on the photosensitive drum 51. The development roller 61 supplies toner to the surface of the exposed photosensitive drum 51. As a result, a toner image is formed on the photosensitive drum 51.

[0032] The photosensitive drum 51 and the transfer roller 74 transport the sheet S supplied from the registration roller 27. As a result, the toner image formed on the photosensitive drum 51 is transferred to the sheet S. The heating roller 81 and the pressure roller 82 transport the sheet S onto which the toner image has been transferred. As a result, the toner image transferred onto the sheet S is fixed onto the sheet S. The intermediate discharge roller 15 and the discharge roller 16 discharge the sheet S onto which the toner image has been fixed onto the discharge tray 13.

[0033] 3 and 4, the developing cartridge 60 includes a frame 100 and two positioning ribs 200. The developing roller 61 is rotatably attached to the frame 100.

[0034] In the embodiment, the four developer cartridges 60 have almost the same structure, and therefore, the following describes the structure of one developer cartridge 60. In the embodiment, the photosensitive drum 51 corresponding to the one developer cartridge 60 corresponds to the "first photosensitive drum." In addition, the three photosensitive drums 51 other than the photosensitive drum 51 corresponding to the "first photosensitive drum" correspond to the "second photosensitive drums."

[0035] The positioning rib 200 is a part that comes into contact with the drum unit 50 when the developer cartridge 60 is attached to the drum unit 50 to determine the position of the frame 100 around the developing roller shaft 61X relative to the drum unit 50. The positioning rib 200 is located on both ends of the outer surface of the frame 100 in the first direction.

[0036] Specifically, the positioning rib 200 has a first positioning rib 200A and a second positioning rib 200B. The first positioning rib 200A is located at one end in the first direction of the outer surface of the frame 100. The second positioning rib 200B is located at the other end in the first direction of the outer surface of the frame 100. In this embodiment, the outer surface of the frame 100 is the surface on one side in the third direction of the frame 100.

[0037] The frame 100 has a toner containing portion 110 and two pressed portions 120 . The toner storage unit 110 is capable of storing toner.

[0038] The pressed portion 120 is a portion that is pressed by the pressing member 54 (see FIG. 5) of the drum unit 50. In this embodiment, the pressed portion 120 is a protrusion that protrudes from the outer surface of the frame 100 to one side in the third direction.

[0039] The pressed portions 120 are located at both ends in the first direction on the outer surface of the frame 100. Specifically, the pressed portion 120 has a first pressed portion 120A and a second pressed portion 120B. The first pressed portion 120A is located at one end in the first direction on the outer surface of the frame 100. The second pressed portion 120B is located at the other end in the first direction on the outer surface of the frame 100.

[0040] 5(a) and 5(b), the drum unit 50 includes two pressing members 54. When the developer cartridge 60 is attached to the drum unit 50, the pressing members 54 press the developer cartridge 60 toward the corresponding photosensitive drum 51. As a result, the pressing members 54 press the developer roller 61 against the corresponding photosensitive drum 51.

[0041] The pressing member 54 has a first pressing member 54A and a second pressing member 54B. The first pressing member 54A presses the first pressed portion 120A when the developer cartridge 60 is attached to the drum unit 50. The second pressing member 54B presses the second pressed portion 120B when the developer cartridge 60 is attached to the drum unit 50.

[0042] The drum unit 50 has a drum frame 53. The first pressing member 54A and the second pressing member 54B each have a pressing lever 541 and a spring 542.

[0043] The pressing lever 541 comes into contact with the pressed portion 120 when the developer cartridge 60 is attached to the drum unit 50. The pressing lever 541 is swingable relative to the drum frame 53 around an axis 54X extending in the first direction. The pressing lever 541 is attached to the drum frame 53 so as to be swingable.

[0044] The spring 542 biases the pressing lever 541 in a direction that presses the pressing lever 541 against the pressed portion 120. As an example, the spring 542 is a torsion coil spring.

[0045] 6(a) and 6(b), when the developer cartridge 60 is attached to the drum unit 50, the frame 100 of the developer cartridge 60 is positioned around the developer roller shaft 61X relative to the drum unit 50. More specifically, when the developer cartridge 60 is attached to the drum unit 50, the position of the frame 100 around the developer roller shaft 61X relative to the drum unit 50 is determined by the positioning rib 200 coming into contact with the drum unit 50.

[0046] The drum unit 50 includes two rollers 55. The positioning rib 200 comes into contact with the rollers 55 of the drum unit 50 when the developer cartridge 60 is attached to the drum unit 50. The rollers 55 are rotatable relative to the drum frame 53 around an axis 55X extending in the first direction. The rollers 55 are rotatably attached to the drum frame 53.

[0047] The rollers 55 include a first roller 55A and a second roller 55B. The first positioning rib 200A contacts the first roller 55A when the developer cartridge 60 is attached to the drum unit 50. The second positioning rib 200B contacts the second roller 55B when the developer cartridge 60 is attached to the drum unit 50.

[0048] 7, the positioning rib 200 is located between the two pressed portions 120 in the first direction. Specifically, the first positioning rib 200A and the second positioning rib 200B are located between the first pressed portion 120A and the second pressed portion 120B in the first direction. The first positioning rib 200A is located on the other side of the first pressed portion 120A in the first direction. The second positioning rib 200B is located on one side of the second pressed portion 120B in the first direction.

[0049] 3 and 4, the positioning rib 200 protrudes from the outer surface of the frame 100. Specifically, the frame 100 has a wall 130. The wall 130 is a wall that intersects with the first direction. In the embodiment, the wall 130 is perpendicular to the first direction. The positioning rib 200 protrudes along the wall 130.

[0050] More specifically, the wall 130 has a first wall 130A and a second wall 130B. The first wall 130A is located next to the first pressed portion 120A on the other side of the first pressed portion 120A in the first direction. The second wall 130B is located next to the second pressed portion 120B on one side of the second pressed portion 120B in the first direction.

[0051] The first positioning rib 200A protrudes along the first wall 130A. In this embodiment, one surface of the first positioning rib 200A in the first direction is flush with the surface of the first wall 130A in the first direction. The second positioning rib 200B protrudes along the second wall 130B. In this embodiment, the other surface of the second positioning rib 200B in the first direction is flush with the surface of the second wall 130B in the first direction.

[0052] As shown in FIGS. 8(a) and 8(b), the contact surface 210 of the positioning rib 200 (200A, 200B) extends along the second direction. The contact surface 210 is the surface of the positioning rib 200 (200A, 200B) that comes into contact with the drum unit 50. The contact surface 210 comes into contact with the drum unit 50 when the developer cartridge 60 is attached to the drum unit 50. Specifically, the contact surface 210 comes into contact with the rollers 55 (see FIG. 6) of the drum unit 50 when the developer cartridge 60 is attached to the drum unit 50.

[0053] The second direction is the direction in which the developer cartridge 60 moves relative to the drum unit 50 when the developer cartridge 60 moves between the contact position (see the solid line in FIG. 1) and the separated position (see the imaginary line in FIG. 1).

[0054] The toner storage section 110 has a protruding portion 111. The protruding portion 111 protrudes further than the first positioning rib 200A and the second positioning rib 200B. More specifically, the protruding portion 111 protrudes further toward one side in the third direction than the first positioning rib 200A and the second positioning rib 200B. The protruding portion 111 is a part of the toner storage section 110 and is capable of storing toner therein. The protruding portion 111 has a substantially triangular shape when viewed along the first direction.

[0055] 3, the protrusion 111 is located between the two positioning ribs 200 in the first direction. More specifically, the protrusion 111 is located between the first positioning rib 200A and the second positioning rib 200B in the first direction. The protrusion 111 extends in the first direction.

[0056] The frame 100 has a recess 140 on its outer surface that is recessed relative to the protrusion 111. The recess 140 has a first recess 140A and a second recess 140B. The first recess 140A is located on one side of the protrusion 111 in the first direction. The second recess 140B is located on the other side of the protrusion 111 in the first direction.

[0057] The positioning ribs 200 are located within the recesses 140. Specifically, the first positioning rib 200A is located within the first recess 140A. The second positioning rib 200B is located within the second recess 140B.

[0058] Next, the effects of the embodiment will be described. The toner storage section 110 is positioned between the first positioning rib 200A and the second positioning rib 200B, and has a protruding portion 111 that protrudes beyond the positioning rib 200 and is capable of storing toner, thereby making it possible to increase the volume of the toner storage section 110.

[0059] Furthermore, since the positioning rib 200 is located in the recess 140 on the outer surface of the frame 100 that is recessed relatively to the protrusion 111, the positioning ribs 200A, 200B are less likely to hit an object or the floor when the developer cartridge 60 is bumped or dropped. This makes it possible to prevent damage to the first positioning rib 200A and the second positioning rib 200B.

[0060] By positioning the first positioning rib 200A and the second positioning rib 200B between the first pressed portion 120A and the second pressed portion 120B in the first direction, the first positioning rib 200A and the second positioning rib 200B are positioned farther from the end of the frame 100 in the first direction than the first pressed portion 120A and the second pressed portion 120B. This makes it less likely that the positioning ribs 200A, 200B will hit an object, the floor, or the like when the end of the developer cartridge 60 in the first direction is hit or dropped from the end of the first direction. This makes it possible to prevent damage to the first positioning rib 200A and the second positioning rib 200B.

[0061] Since the first positioning rib 200A protrudes along the first wall 130A of the frame 100, the first positioning rib 200A can be supported by the first wall 130A, thereby ensuring the strength of the first positioning rib 200A. Since the second positioning rib 200B protrudes along the second wall 130B of the frame 100, the second positioning rib 200B can be supported by the second wall 130B, thereby ensuring the strength of the second positioning rib 200B.

[0062] The contact surface 210 of the first positioning rib 200A extends along a second direction, which is the direction of movement of the developer cartridge 60 relative to the drum unit 50, and the contact surface 210 of the second positioning rib 200B extends along the second direction, allowing the developer cartridge 60 to move smoothly relative to the drum unit 50.

[0063] Although the embodiment has been described above, the developing cartridge and the image forming apparatus can be modified as appropriate as exemplified below.

[0064] In the embodiment, the first positioning rib 200A and the second positioning rib 200B were located between the first pressed portion 120A and the second pressed portion 120B in the first direction, but for example, the first pressed portion and the second pressed portion may be located between the first positioning rib and the second positioning rib in the first direction.

[0065] In the embodiment, the first positioning rib 200A protrudes along the first wall 130A, but the first positioning rib may protrude from a position closer to the center of the frame than the first wall in the first direction. The same applies to the second positioning rib and the second wall.

[0066] In the embodiment, the developer cartridge 60 was movable between a contact position and a separated position relative to the drum unit 50, but for example, the developer cartridge may be configured not to move relative to the drum unit when attached to the drum unit.

[0067] In the embodiment, the drum unit 50 includes the first photosensitive drum and three second photosensitive drums aligned with the first photosensitive drum, but the number of second photosensitive drums may be, for example, two or less, or four or more. Also, the drum unit may include only the first photosensitive drum and not the second photosensitive drum.

[0068] In the embodiment, the image forming apparatus 1 is a color printer capable of forming color images, but the image forming apparatus may be, for example, a monochrome printer capable of forming only monochrome images. The image forming apparatus may also be a copier or a multifunction peripheral.

[0069] The elements described in the embodiments and modifications may be implemented in any combination. [Explanation of symbols]

[0070] 1. Image forming device 50 drum unit 51 Photosensitive drum 60 Developer cartridge 61 Developing roller 61X Developing roller shaft 100 frames 110 Toner storage unit 111 Protrusion 200A First positioning rib 200B Second positioning rib

Claims

1. A developing cartridge detachably attached to a drum unit including a first photosensitive drum, a developing roller rotatable about a developing roller axis extending in a first direction; a frame whose position around the axis of the developing roller is determined relative to the drum unit; a first positioning rib located at one end of an outer surface of the frame in the first direction, the first positioning rib protruding from the outer surface of the frame and contacting the drum unit to determine the position of the frame around the developing roller axis relative to the drum unit; a second positioning rib located at the other end of the outer surface of the frame in the first direction, the second positioning rib protruding from the outer surface of the frame and contacting the drum unit to determine the position of the frame around the developing roller axis relative to the drum unit, the frame has a toner storage portion capable of storing toner, A developing cartridge characterized in that the toner storage portion is located between the first positioning rib and the second positioning rib in the first direction, and has a protruding portion that protrudes beyond the first positioning rib and the second positioning rib, and is capable of storing toner.

2. The frame is a first pressed portion located at one end of an outer surface of the frame in the first direction, the first pressed portion being pressed by a pressing member of the drum unit; a second pressed portion located at the other end of the outer surface of the frame in the first direction, the second pressed portion being pressed by a pressing member of the drum unit; 2. The developing cartridge according to claim 1, wherein the first positioning rib and the second positioning rib are located between the first pressed portion and the second pressed portion in the first direction.

3. the frame has a wall that intersects with the first direction, 2. The developing cartridge according to claim 1, wherein the first positioning rib and the second positioning rib protrude along the wall.

4. the developing cartridge is movable relative to the drum unit in a second direction intersecting the first direction between a contact position where the developing roller contacts the first photosensitive drum and a separation position where the developing roller is separated from the first photosensitive drum, a surface of the first positioning rib that contacts the drum unit extends along the second direction; 2. The developing cartridge according to claim 1, wherein the surface of the second positioning rib that contacts the drum unit extends along the second direction.

5. the drum unit; An image forming apparatus comprising the developing cartridge according to any one of claims 1 to 4, The image forming apparatus, wherein the drum unit further includes at least one second photosensitive drum aligned with the first photosensitive drum.

Images