Toner frame, process cartridge and image forming apparatus

Abstract: A toner frame usable with a main assembly of an electrophotographic image forming apparatus, includes (a) a toner containing portion for containing toner to be supplied to a developing member for developing a latent image formed on an electrophotographic photosensitive member; (b) a toner supply opening for supplying the toner into the toner containing portion, wherein the toner supply opening is provided in a longitudinal end portion of the toner containing portion; and (c) a supporting portion for supporting one end portion of a stirring member for stirring toner contained in the toner containing portion, wherein the supporting portion is disposed within a range of the toner supply opening and at a position deviated from a center of the toner supply opening, as seen in a longitudinal direction of the toner frame.

Description: FIELD OF THE INVENTION AND RELATED ART The present invention relates to a toner container frame and a process cartridge. A process cartridge means a cartridge which is removably installable in the main assembly of an image forming apparatus, and in which a means for developing latent images formed on an electrophotographic photosensitive member, and an electrophotographic photosensitive member, are integrally disposed. A process cartridge may be a removable cartridge which comprises an electrophotographic photosensitive member, and at least a member for charging an electrophotographic photosensitive member or a cleaning member for removing the developer which remains on the electrophotographic photosensitive member, in addition to a developing means. An electrophotographic image forming apparatus means an apparatus which forms images on recording medium with the use of an electrophotographic image forming system. For example, electrophotographic copying machines, electrophotographic printers (laser beam printers, LED printers, and the like), facsimile machines, word processors, and the like are the typical electrophotographic image forming apparatuses. Electrophotographic image forming apparatuses such as electrophotographic copying machines or laser beam printers comprise a photosensitive drum, which is subjected to known image forming processes, for example, charging, exposing, developing, and the like, to form toner images on a photosensitive drum. The toner image formed on the photosensitive drum is transferred onto recording medium such as a sheet of transfer paper or the like. Thereafter, the toner particles which remain on the photosensitive drum are removed, or cleaned, by a cleaning device. In recent years, in order to reduce the size of an electrophotographic image forming apparatus, and to simplify the maintenance of an image forming apparatus, process cartridge systems have become very popular. A process cartridge system means a system in which a photosensitive drum, and processing means which act on the photosensitive drum, are integrally disposed in a cartridge which can be removably installed in the main assembly of an image forming apparatus by users themselves. As described above, the processing means are a charging member, a developing member, a cleaning member, and/or the like. The lateral walls, that is, the walls located at the longitudinal ends, of the aforementioned process cartridge are provided with a bearing which supports a toner stirring rod, and a mouth through which toner is filled into the cartridge. The stirring rod stirs and advances the toner in the process cartridge. Positioning the toner filling mouth at the lateral end of a process cartridge makes it easier to fill toner evenly throughout the toner space of the process cartridge. Further, the larger the mouth, the better the efficiency with which toner is filled. The bearing for the toner stirring rod must be properly located in consideration of various factors. Generally, process cartridges are structured so that the location of the center of the opening of the toner filling mouth substantially coincides with the location of the center of the bearing for the toner stirring rod. More specifically, the opening of the toner filling mouth is provided with ribs, which are disposed across the opening in such a manner that they intersect with each other at the substantial center of the opening, as if they radially extend from the center of the opening, and evenly divide the opening, and the bearing is located at the intersection of the ribs. SUMMARY OF THE INVENTION An object of the present invention is to provide a toner frame and a process cartridge, in which the members for supporting a toner stirring member, and the toner filling mouth of the toner space, are properly positioned. Another object of the present invention is to provide a toner frame, and a process cartridge, in which the members for supporting a toner stirring member are properly positioned even though the toner space is provided with a toner filling mouth with improved toner filling efficiency. Furthermore, the invention provides an electrophotographic image forming apparatus. According to an aspect of the present invention, there is provided a toner frame usable with a main assembly of an electrophotographic image forming apparatus, comprising: (a) a toner containing portion for containing toner to be supplied to a developing member for developing a latent image formed on an electrophotographic photosensitive member; (b) a toner supply opening for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion of said toner containing portion; and (c) a supporting portion for supporting one end portion of a stirring member for stirring toner contained in said toner containing portion, wherein said supporting portion is disposed within a range of said toner supply opening and at a position deviated from a center or centroid of said toner supply opening, as seen in a longitudinal direction of said toner frame. These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention, taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective external view of the left side of a process cartridge in an embodiment of the present invention. Figure 2 is a vertical section of a typical image forming apparatus in which a typical process cartridge has been installed, depicting the structures thereof. Figure 3 is a vertical section of a process cartridge, depicting the general structure thereof. Figure 4 is a perspective view of the toner container section of a process cartridge. Figure 5 is a perspective view of a typical image forming apparatus, in which a process cartridge is being installed, or from which a process cartridge is being removed. Figure 6 is a perspective view of the inward side of the right-hand side of an image forming apparatus, depicting the right-hand guide, along which a process cartridge is installed or removed. Figure 7 is a perspective view of the inward side of the left-hand side of the image forming apparatus, depicting the left-hand guide, along which a process cartridge is installed or removed. Figure 8 is a schematic section of an image forming apparatus, in which a process cartridge is being installed. Figure 9 is a schematic section of an image forming apparatus, in which a process cartridge is being installed. Figure 10 is a vertical section of the toner container section of a process cartridge, parallel to the longitudinal direction of the cartridge. Figure 11 is a plan view of the lateral wall of the toner container section of a process cartridge, depicting the structure of the toner filling mouth in the first embodiment of the present invention. Figure 12 is a plan view of the lateral wall of the toner container section of a process cartridge, depicting the structure of the toner filling mouth in the second embodiment of the present invention. Figure 13 is a schematic section of a toner container section of a process cartridge, depicting a method for filling a toner space with toner. Figure 14 is a vertical section of the toner container section of a process cartridge in the third embodiment of the present invention, parallel to the longitudinal direction of the process cartridge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. In the following embodiments of the present invention, the present invention will be described with reference to a laser beam printer. Further, in the following embodiments, the horizontal direction which is perpendicular to the direction in which a process cartridge is installed into, or removed from, an image forming apparatus, will be referred to "longitudinal direction". Embodiment 1 Referring to Figures 1 - 11, a typical process cartridge, and a typical image forming apparatus in which the process cartridge is installable, will be concretely described. Figure 1 is a perspective external view of the process cartridge, and Figure 2 is a schematic section of the image forming apparatus in which the process cartridge has been installed, and depicts the general structures thereof. Figure 3 is a vertical section of the process cartridge, and depicts the general structure thereof, and Figure 4 is a perspective view of the toner container section of the process cartridge. Figures 5 - 7 are perspective views of the entirety of the image forming apparatus, the inside of the right-hand portion of the image forming apparatus, and the inside of the left-hand portion of the image forming apparatus, which depict the structure of the means for installing the process cartridge. Figures 8 and 9 are schematic vertical sections of the image forming apparatus in which the process cartridge is being installed. Figure 10 is a vertical section of the toner container frame, parallel to the longitudinal direction of the process cartridge. Figure 11 is a plan view of the lateral wall of the toner container portion of the process cartridge, depicting the details of the present invention. {General structure} In this section, a process cartridge in accordance with the present invention, and an image forming apparatus compatible with such a process cartridge, will be described in terms of their general structures. Referring to Figure 2, in this electrophotographic image forming apparatus (laser beam printer) A, images are formed through the following steps. First, a beam of light modulated with the optical information of a target image is projected from an optical system 1 onto the peripheral surface of the cylindrical electrophotographic photosensitive member of the image forming apparatus, forming a latent image thereon. This latent image is developed with developer (hereinafter, "toner") into a toner image. During the formation of the toner image, a sheet of recording medium 2 is separated from the rest of the sheets in a sheet feeder cassette 3a, and sent out of a cassette 3a, into the main assembly of the image forming apparatus, by a pickup roller 3b, and a pressing member 3c which is pressed upon a pickup roller 3b. Then, in synchronism with the conveyance of the toner image, the recording medium 2 is delivered by a conveying means 3, which is constituted of a conveyer roller pair 3d, a registration roller pair 3e, and the like, to the location of a transfer roller 4 as a means for transferring to the recording medium 2 the toner image formed on the electrophotographic photosensitive member in a process cartridge B. At the transfer roller 4, the toner image is transferred onto the recording medium 2 by applying voltage to the transfer roller 4. After receiving the toner image, the recording medium 2 is delivered to a fixing means 5 by a conveyer belt 3f. The fixing means 5 is constituted of a driver roller 5a and a cylindrical rotative member 5d. The cylindrical rotative member 5d contains a heater 5b and is rotatively supported by a supporting member 5c. As the recording medium 2 is passed through the fixing means 5, the toner image is permanently fixed to the recording medium 2 through the application of heat and pressure. After the fixation of the toner image, the recording medium 2 is conveyed through a reversing path, and then is discharged into a delivery tray 6, by discharge roller pairs 3g and 3h. In the case of this image forming apparatus A, the recording medium 2 may be manually fed with the use of a manual feeder tray 3i and a roller 3j. {Process cartridge} Referring to Figure 3, in the process cartridge B in this embodiment, a photosensitive drum 7, which is an electrophotographic photosensitive member with a photosensitive layer, is rotated, and the peripheral surface of the photosensitive drum 7 is uniformly charged by applying voltage to a charge roller 8, that is, a charging means. The charged surface of the photosensitive drum 7 is exposed to an optical image projected from the aforementioned optical system 1 through an opening 9, to form a latent image on the charged surface. The formed latent image is developed by a developing means 10. In the developing means 10, the toner in the toner container portion 10a of a developer container is advanced, while being stirred, toward a development roller 10d, by rotating first and second toner advancing members 10b1 and 10b2, which constitute the toner advancing means. The development roller 10d is a cylindrical rotative member in which a stationary magnet 10c is fixedly disposed. The toner which has advanced to the development roller 10d is coated, while being regulated by a development blade 10e, on the peripheral surface of the development roller 10d, forming a toner layer composed of triboelectrically charged toner particles. The charged toner particles are transferred onto the peripheral surface of the photosensitive drum 7, in a manner to reflect the latent image. As a result, the latent image is visualized as a toner image. The toner image is transferred onto the recording medium 2 by applying to the transfer roller 4 such voltage that is opposite in polarity to the toner image. Thereafter, the peripheral surface of the photosensitive drum 7 is cleaned by cleaning means 11; the toner particles which remain on the photosensitive drum 7 are scraped off by a cleaning blade 11a, scooped up by a scooping sheet 11b, and then, collected into a waste toner container 11c. The cartridge shell has an opening, which faces the interface between the photosensitive drum 7 and the transfer roller 4. The opening is covered with a drum shutter 28. This drum shutter 28 is attached to the cartridge shell with the use of a four-joint linkage system constituted of a linkage member 29, an arm member 27, and the like (Figures 8 and 9). The aforementioned members such as the photosensitive drum 7 are integrally disposed in the cartridge shell, which is formed by joining a shell portion 12 which contains the toner container portion and the developing means, with a shell portion 13 which contains cleaning means. The shell portion 12 is formed by welding together a shell portion 12a which contains the developing means, a shell portion 12e which constitutes the vessel portion of the toner container portion, and a shell portion 12c which constitutes a cover portion of the toner container portion, at flanges 12f and 12d, correspondingly. {Structure for installing or removing process cartridge) Next, the structure for installing the aforementioned process cartridge B into the main assembly 14 of an image forming apparatus, or removing the process cartridge B from the main assembly 14, will be described. Referring to Figure 5, the process cartridge B is installed or removed in the following manner. First, a lid 15 is opened by rotating it about an axis 15a (Figure 2), to expose a cartridge installing means. Next, referring to Figures 6 and 7, there are guide rails 16, one for each lateral side of the cartridge installation space, being positioned symmetrically to each other, and slanted downward, with a slight curvature (in this embodiment, it is curved like an arc). Above each of the guide grooves 16, there is a guide member 17. The entrance side end of the guide rail 16 is connected to a second slanted surface 16b, and the entrance side of the second slanted surface 16b is connected to a first slanted surface 16a. The second slanted surface 16b is slanted more steeply than the first slanted surface 16a. The first slanted surface 16a constitutes a hooking portion with which the projection 29b of the linkage member 29 for opening or closing the drum shutter 28 of the process cartridge B is engaged. On the other hand, the process cartridge B is provided with guide portions; each of the lateral walls of the process cartridge is provided with a guide portion, which projects outward in the longitudinal direction from the outward surface of the lateral wall. The left-hand and right-hand guide portions are symmetrical to each other, their locations being correspondent to the locations of the left-hand and right-hand guide rails 16, and are guided by the corresponding guide rails 16 when the process cartridge B is installed into, or removed from, the main assembly 14 of the image forming apparatus. Referring to Figure 1, each of the guide portions of the process cartridge B integrally comprises a boss 18a, which constitutes the first guide portion, and a rib 18b, which constitutes the second guide portion. The boss 18a is positioned on the imaginary extension of the rotational axis of the photosensitive drum 7. The rib 18b extends rearward, relative to the direction in which the process cartridge is inserted, from the boss 8a, bowing slightly downward to match the profile of the guide rail 16 (in this embodiment, its profile is substantially in the form of an arc). Referring to Figure 8, when installing the process cartridge B, the process cartridge B is positioned so that the boss 18a and the rib 18b are placed in contact with the guide rail 16. Then, the process cartridge B is pushed into the apparatus main assembly 14, with the boss 18a and the rib 18b sliding on the rail 16, in such a manner that the leading end of the process cartridge B goes under the optical system 1. Since the guide rail 16, and the bottom wall of the guide member 17 located above the guide rail 16, are arc-shaped in profile, and the rib 18b is also given the arc-shaped profile, the process cartridge B becomes horizontally positioned as it is inserted more deeply. Referring to Figure 9, as the process cartridge B is farther inserted, a surface area 20, one for each of the lateral ends, which is the surface area near the leading end of the shell portion 13 for the cleaning means, comes in contact with the projection 19 of the apparatus main assembly 14. Then, the boss 18a of the process cartridge B drops into the recess 16c located at the deepest end of the guide rail 16. As the boss 18a drops into the recess 16c, an unillustrated drum gear fixed to one of the longitudinal ends of the photosensitive drum 7 engages with a driving gear 22 (Figure 7) on the side of the apparatus main assembly 14, enabling driving force to be transmitted from the apparatus main assembly 14 to the process cartridge B. Meanwhile, the projection 29b of the linkage member 29 is prevented from entering more deeply into the apparatus main assembly 14, by the first and second slanted surfaces 16a and 16b, causing the shutter 28 to open. {Filling of toner} Referring to Figure 4, the shell portion 12e which constitutes the bottom portion of the toner container portion is provided with an opening 12g (Figure 3), which is surrounded by a surface 12k which is recessed from the surface of the flange portion 12f of the shell portion 12e. This opening 12g is covered with a cover film 51, which is easily tearable in the longitudinal direction of the recessed surface 12k. The cover film is pasted to the recessed surface 12k, along all four edges of the opening 12g. To this cover film 51, a tear tape 52, which is used to tear open the cover film 51, that is, to unseal the opening 12g, is welded. The tear tape 52 is folded back at one of the longitudinal ends of the opening 12g (end 52b in the drawing), is extended all the way back, put through between the surface of the flange of the frame portion 12e, and an elastic seal (unillustrated) formed of felt or the like, and then, allowed to stick out of the process cartridge B. The end 52a of the portion of the tear tape 52, which is sticking out of the process cartridge B, is pasted to a handle 12h, which is integrally formed with the shell portion 12e. The portion which connects the shell portion 12e and the handle 12h is formed thin enough to allow the handle 12h to be easily separated from the shell portion 12e. In assembling the process cartridge B, first, the shell portion 12c which constitutes the lid portion of the cartridge, is welded to the shell portion 12e which constitutes the vessel portion of the toner container portion. Next, a first toner advancing member 10bl is assembled into the toner container portion 10a. Thereafter, the opening 12g of the shell portion 12e is sealed with the cover film 51. Then, toner is filled into the toner container portion 10a, which is the space surrounded by the shell portion 12e and the shell portion 12c, through the toner filling mouth 32, which will be described later (Figure 12). Next, the top and bottom ribs of the shell portion 12a for the developing means are fitted into the top and bottom grooves 12n located at the top and bottom edges of the flange 12f of the shell portion 12e, and the top surface of the rib and the bottom surface of the groove are welded to each other with the use of ultrasonic waves. In using the process cartridge B for the first time, the handle 12h must be pulled. As the handle 12h is pulled, the tear tape 52 is pulled out of the process cartridge B, tearing the cover film 52, and therefore exposing the opening 12g. As a result, the toner within the toner container portion 10a shifts toward the shell portion 12a for the developing means. Referring to Figures 2 and 3, during image formation, the first toner advancing member 10b1 is rotated clockwise by the rotation of the photosensitive drum 7, advancing, while stirring, the toner to the development roller 10d. Referring to Figure 11, the first toner advancing means 10bl is constituted of a stirring rod 31a, a bearing 31b located within the opening of the toner filling mouth 32, and ribs 31c which extend across the opening, intersecting with each other at the substantial center of the opening, as if radially extending from the center of the opening, and therefore, equally dividing the opening. Referring to Figure 10, the stirring rod 31a is in the form of a crank, being constituted of journal portions 31a1 and 31a3, an arm portion 31a2, and a pin portion 31a4. It is formed by bending a piece of metallic wire, which is desired to be 1 - 4 mm, preferably, approximately 2.6 mm, in thickness. Referring to Figures 10 and 11, the toner filling mouth 32 is cylindrical, and is located at one of the lateral ends of the shell portion 12e which constitutes the vessel portion of the toner container portion. It is sealed with a toner container cap 33 after the toner container portion 10a is filled with toner. The outward side opening of the toner filling mouth 32 is provided with ribs 31c, one of which is provided with the bearing 31b. Next, the positional relationship among the components in the process cartridge B will be described. Figure 10 is a schematic vertical section of the toner container portion of the cartridge shell, parallel to the rotational axis of the first toner advancing member 10b1. In the drawing, a gear cover 12j and a side cover 12m are screwed to one of the longitudinal ends of the toner container shell portion 12e, and the other end, respectively. The inner wall of the gear cover 12j is provided with a bearing 12i, which rotatively supports a stirring rod supporting shaft which integrally comprises a gear 10h1 and a journal 10h. As described above, the first toner advancing member 10b1 is in the form of a crank, and one of the journal portions, that is, the journal portion 31a1, of the toner advancing member 10b1 is fitted in the center hole of the journal 10h. The arm portion 31a2 next to the journal portion 31a1 is fitted in a groove 10h2 cut in the inward surface of the journal 10h, radially from the center hole of the journal 10h. The other journal 31a3 of the stirring rod 31a of the toner advancing member 10b1 is supported by a bearing 31b integral with the inward wall of the side cover 12m of the toner container shell portion 12e. The aforementioned gear 10h1 is connected, through an unillustrated gear train, to an unillustrated drum gear fixed to the photosensitive drum 7. Thus, as the photosensitive drum 7 rotates in the clockwise direction in Figures 2 or 3, the stirring rod 31a of the first toner advancing member 10b1 rotates in the same direction about the journals 31a1 and 31a3, and the arm portion 31a2 and the pin portion 31a4 advance, while stirring, the toner within the toner container portion 10a to the development roller 10d. Figure 11 shows the positioning of the bearing 31b, on the toner filling mouth 32 side, for supporting the stirring rod 31a. This bearing 31b is formed as a part of one of the ribs 31c which are integral parts of the toner container shell portion 12e. It is slightly off from the center of the opening of the toner filling mouth, toward the development roller 10d. More specifically, the center of the opening of the toner filling mouth 32 coincides with the location of the intersection 31c1 of the ribs 31c which extend across the opening of the cylindrical toner filling mouth 32, as if radially extending from the center of the opening, dividing the opening into. substantial quadrants of equal size. The bearing 31b is positioned slightly off from this intersection 31c1 toward the surface of the flange 12f, at which the toner container shell portion 12e is joined with the developing means containing portion of the cartridge shell, and also diagonally downward. In other words, the bearings 12i and 31b which support the journals 31a1 and 31a3, respectively, of the stirring rod 31a are positioned so that the stirring rod 31a, the arm portions 31a2 of which have been shortened to meet the goal of reducing the process cartridge size, is properly positioned. In an attempt to reduce the process cartridge size, the toner filling mouth is located in the one of the lateral walls of the toner container shell portion 12e, while rendering the opening of the toner filling mouth as large as possible. Further, in consideration of the shape of the lateral wall of the toner container shell portion 12e, the bearing 31b is positioned within the opening of the toner filling mouth 32. In the actual design, the ribs 31c are positioned so that one of the ribs 31c goes through the center of the opening of the toner filling mouth 32, as well as the center of the bearing 31b. The bearing 31b is integrally formed with the rib 31c. As described above, the ribs 31c are integrally formed with the toner container shell portion 12e. However, the ribs 31c and the bearing 31b may be separately formed from the toner container shell portion 12e. In such a case, they are integrally formed with a ring which perfectly fit in the opening of the toner filling mouth 32, and this ring which integrally comprises the ribs 31c and the bearing 31b is fixedly fitted in the opening of the toner filling mouth 32. The diameter of the opening of the toner filling mouth 32 is 30 - 40 mm, preferably, approximately 34 mm. With the above arrangement, the stirring rod 31a is positioned at the best location for advancing, while stirring, the toner to the development roller 10d, and at the same time, the size of the opening of the toner filling mouth 32 can be increased. In determining the position of the bearing 31b, the gap between the pin portion 31a4 and the bottom wall of the toner container shell portion 12e must be taken into consideration. If this gap is extremely large, the amount of the toner which fails to be advanced all the way to the development roller 10d and remains in the toner container shell portion 12e, increases. On the other hand, if this gap is designed to be extremely small, production errors or the like may cause such a problem that the pin portion 31a4 collides with the bottom wall of the toner container shell portion 12e as the arm portion 31a2 rotates within the toner container portion. Also regarding the positioning of the bearing 31b, the positioning of the second toner advancing member 10b2 must be taken into consideration. In other words, the bearing 31b must be positioned so that the first toner advancing member 10b1 is allowed to work in coordination with the second toner advancing member 10b2 to circulate the toner in a wider range. If the toner is circulated in only a small range, only the same toner particles are regulated by the development blade 10e, which is liable to cause such a problem that the material coated on the toner particle surface to control the amount of charge is shaved off by the friction among the toner particles. Thus, the bearing 31b is desired to be properly positioned in consideration of the aforementioned plurality of factors. At this time, referring to Figure 11, the configuration of the lateral wall 12p of the toner container shell portion 12e will be described. In Figure 11, the length L1 of the shorter vertical edge of the lateral wall 12p should be 15 - 25 mm, desirably, approximately 20 mm, and the length L2 of the longer vertical edge of the lateral wall 12p should be 37 - 47 mm, desirably, approximately 42.5 mm. The length L3 of the horizontal top edge of the wall 12p should be 70 - 80 mm, desirably, approximately 74.7 mm. As for the bottom edge of the wall 12p, which comprises a straight portion and an arc portion, the radius of the arc portion should be 18 - 28 mm, desirably, approximately 23.1 mm, and the location of the center of the curvature of the arc portion is desired to approximately coincide with the location of the center of the bearing 31b. Further, the length L5 between the center of the opening of the toner filling mouth 32 and the long vertical edge should be 18 - 27 mm, desirably, approximately 22.3 mm. The length L4 between the center of the opening of the toner filling mouth 32 to the horizontal top edge of the wall 12p should be 19 - 29 mm, desirably, approximately 23.7 mm. The length L6 between the center of the bearing 32b and the long vertical edge should be 13 - 23 mm, desirably, approximately 17.8 mm. The length L7 between the center of the bearing 32b and the horizontal top edge should be 22 - 32 mm, desirably, approximately 26.6 mm. The diameter dl of the bearing 31b should be 1 - 4 mm, desirably, approximately 2.6 mm. Also referring to Figure 11, the ribs 31c are disposed across the opening portion of the toner filling mouth 32 as if radially extending from the center of the opening toward the edge of the opening, and divide the opening into quadrants. In filling toner, the process cartridge B is caused to stand on the lateral wall opposite to the lateral wall with the toner filling mouth 32, that is, it is positioned so that the longitudinal direction of the shell portion 12 which contains the toner and the developing means becomes vertical, and then, the toner is filled into the toner container space 10a through the toner filling mouth 32 by allowing the toner to fall into the space 10a. Since the ribs 31c are disposed, as if radially extending from the center of the opening of the toner filling mouth 32, and divide the opening into quadrants, none of the gaps between the adjacent two ribs 31c is reduced in size, and therefore, the toner can be easily filled. In this embodiment, two ribs 31c are disposed across the opening, in a manner to perpendicularly cross each other at the center of the opening. However, one of the ribs 31c, which does not integrally comprise the bearing 31b, does not need to be present. In other words, the number of ribs 31c which are placed across the center of the opening of the toner filling mouth 32 may be only one. Referring to Figure 13, in filling toner into the toner container space 10a, the shell portion 12 which contains the toner and the developing means, that is, the cartridge shell portion which is formed by welding the shell portion 12c which constitutes the lid portion of the toner container portion, to the toner container shell portion 12e which constitutes the vessel portion of the toner container portion, is caused to stand in such a manner that the longitudinal direction of the cartridge shell becomes vertical, and then, a predetermined amount of toner T is filled into the toner space 10a by a toner filling apparatus 38 through the toner filling mouth 32. Embodiment 2 In Embodiment 1 described above, the toner filling mouth 32 was cylindrical, but it may have a square cross section as illustrated in Figure 12. In such a case, the ribs 31c are diagonally placed across the square opening of the toner filling mouth 32 in a manner to perpendicularly cross each other at a point 31c1, and the bearing 31b for supporting the stirring rod 31a is positioned slightly off from the cross section 31c1 toward the flange 12f. Further, the toner filling mouth may be shaped so that its cross section becomes triangular or semicircular. When the cross section of the toner filling mouth 32 is triangular or semicircular, the bearing 32b is farther off from the center of the opening toward the development roller 10d. Embodiment 3 In Embodiment 1 described above, the stirring rod bearing 32b which supports the stirring rod 31a is located within the opening of the toner filling mouth 32. In this embodiment, not only is the stirring rod bearing 32b positioned within the opening of the toner filling mouth 32, but also a member for driving the stirring rod 31a is positioned within the opening. Referring to Figure 14, in this Embodiment 3, one end of the stirring rod 31a is rotatively supported simply by the lateral wall of the toner container shell portion 12e, and the other end of the stirring rod 31a is fitted in, being thereby supported by, a stirring rod supporting shaft 10i. The shaft 10i is rotatively supported by a bearing 33a integral with a toner container cap 33, which is removably press-fitted in the toner filling mouth 32 (engagement between the stirring rod 31a and the stirring rod supporting shaft 10i is the same as in Embodiment 1). The stirring rod bearing 33a is off from the center of the opening of the toner filling mouth 32 toward the development roller 10d, as well as toward the bottom wall of the toner container shell portion 12e. With this arrangement, the size of the toner filling mouth 32 can be increased to a size necessary for efficiently filling the toner space 10a with toner. It will be understood that if the mouth 32 is circular in shape, means to orient the cap 33 correctly in the mouth 32, such as an engaging recess and projection or key, will be provided. In this Embodiment 3, there is no rib 31c in the toner filling mouth 32, and therefore, it is that much easier to fill the toner into the toner space 10a. Alternatively, the positioning of the stirring rod bearing 32b may be such that the rib(s) 31c and the stirring rod bearing 32b are integrally formed with the toner container shell portion 12e to support the stirring rod 31a in the same manner as described in the preceding embodiments, and the stirring rod supporting shaft 10i is supported by the bearing 33a, which is integrally formed with the toner container cap 33, and located at a point where the extension of the stirring rod journal 31a3 meets the toner container cap (this arrangement is unillustrated). Other embodiments In the preceding embodiments, the bearing 31b is located between the longitudinal ends of one of the ribs 31c, but the positioning of the bearing 31b does not need to be limited to those described in the preceding embodiments. For example, the positioning of the bearing 31b may be such that a rib is extended from the circular edge of the opening of the toner filling mouth, toward the center of the opening, and the bearing 31b is located at the tip of the thus extended rib. In summary, according to the present invention, there is provided a toner frame (e.g. 12e) usable with a main assembly of an electrophotographic image forming apparatus (e.g. A), comprising: (a) a toner containing portion (e.g. 10a) for containing toner to be supplied to a developing member (e.g. 10d) for developing a latent image formed on an electrophotographic photosensitive member (e.g. 7); (b) a toner supply opening (e.g. 32) for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion (e.g. 12p) of said toner containing portion; and (c) a supporting portion (e.g. 31b) for supporting one end portion of a stirring member (e.g. 31a) for stirring toner contained in said toner containing portion, wherein said supporting portion is disposed within a range of said toner supply opening and at a position deviated from a centroid or center of said toner supply opening, as seen in a longitudinal direction of said toner frame. The toner frame may comprise a first rib (e.g. 31c) bridging said opening, and said supporting portion is provided in said first rib. The toner frame may comprise a second rib (e.g. 31c) bridging said opening in a direction crossing with said first rib. The toner frame may comprise said first and second ribs crossed with each other at the center of said opening. In the toner frame, said toner containing portion, said supporting portion, said first rib and said second rib may be of integrally formed plastic material. In the toner frame, said toner supply opening may be circular, square or any other convenient shape. In the toner frame, said toner containing portion is provided with toner discharge opening (e.g. 12g) through which the toner is supplied out of said toner containing portion toward said developing member, and said supporting portion is provided at the position deviated from the center toward said toner discharge opening. In the toner frame, said range contains a longitudinal extension of said toner supply opening. In the toner frame, a second opening (e.g. 12i) is provided in a longitudinal end portion opposite from said longitudinal end portion having said toner supply opening and is capable of supporting the other end portion of said stirring member. In the toner frame, a center of said supporting portion is deviated approx. 2-10mm from the center of said toner supply opening. In the toner frame, said stirring member including, at it central part, an arm portion (31a2) extending in a radial direction of its rotation. As is evident from the preceding embodiments described above, the present invention makes it possible to provide a toner container shell portion, and a process cartridge, in which the supporting portion for the toner stirring member, and the toner filling mouth, are properly positioned. Further, the present invention makes it possible to provide a toner container shell portion, and a process cartridge, in which the supporting portion for the toner stirring member is properly positioned even though the toner container shell portion is provided with a toner filling mouth with desirable toner filling efficiency. While the invention has been described with reference to the structures disclosed herein, it is not confined to the details set forth, and this application is intended to cover such modifications or changes as may come within the scope of the following claims.

Claims: A toner frame (12e) usable with a main assembly (A) of an electrophotographic image forming apparatus, comprising: (a) a toner containing portion (10a) for containing toner to be supplied to a developing member (10d) for developing a latent image formed on an electrophotographic photosensitive member (7); (b) a toner supply opening (32) for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion of said toner containing portion; and (c) a supporting portion (31b) for supporting one end portion (31a3) of a stirring member (10b1,31a) for stirring toner contained in said toner containing portion, wherein said supporting portion is disposed within a range of said toner supply opening and at a position deviated from a center or centroid of said toner supply opening, as seen in a longitudinal direction of said toner frame. A toner frame according to claim 1, further comprising a first rib (31c) bridging said opening (32), and said supporting portion (31b) is provided in said first rib. A toner frame according to claim 2, further comprising a second rib (31c) bridging said opening (32) in a direction crossing with said first rib. A toner frame according to claim 3, further comprising said first and second ribs crossed with each other at the center (31c1) of said opening (32). A toner frame according to claim 4, wherein said toner containing portion (10a), said supporting portion (31b), said first rib (31c) and said second rib (31c) are of integrally formed plastics material. A toner frame according to claim 1, wherein said toner supply opening (32) is circular. A toner frame according to claim 1, wherein said toner containing portion is provided with toner discharge opening (12g) through which the toner is supplied out of said toner containing portion toward said developing member, and said supporting portion is provided at the position deviated from the center or centroid toward said toner discharge opening. A toner frame according to claim 1, wherein said range contains a longitudinal extension of said toner supply opening. A toner frame according to claim 1, wherein a second opening (12i) is provided in a longitudinal end portion opposite from said longitudinal end portion having said toner supply opening and is capable of supporting the other end portion (31a1) of said stirring member (31a). A toner frame according to claim 1, wherein a center of said supporting portion (31b) is deviated approx. 2-10 mm from the center (31c1) of said toner supply opening (32). A toner frame according to claim 1, wherein said stirring member (31a) includes, at its central part, a pin portion (31a4) offset in a radial direction from its axis of rotation. A process cartridge (B) detachably mountable relative to a main assembly (A) of an image forming apparatus, comprising: (a) an electrophotographic photosensitive member (7); (b) a developing member (10d) for developing a latent image formed on said electrophotographic photosensitive member; (c) a toner frame (12e) including: a toner containing portion (10a) for containing toner to be supplied to said developing member; a toner supply opening (32) for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion of said toner containing portion; and a supporting portion (31b) supporting one end portion of a stirring member (10b1, 31a) for stirring toner contained in said toner containing portion, wherein said supporting portion is disposed within a range of said toner supply opening and at a position deviated from a center or centroid of said toner supply opening, as seen in a longitudinal direction of said toner frame. A process cartridge according to claim 12, further comprising a first rib (31c) bridging said opening, and said supporting portion (31b) is provided in said first rib. A process cartridge according to claim 13, further comprising a second rib (31c) bridging said opening in a direction crossing with said first rib (31c). A process cartridge according to claim 14, further comprising said first and second ribs crossed with each other at the center (31c1) of said opening. A process cartridge according to claim 15, wherein said toner containing portion (10a), said supporting portion (31b), said first rib (31c) and said second rib (31c) are of integrally formed plastics material. A process cartridge according to claim 12, wherein said toner supply opening (32) is circular. A process cartridge according to any of claims 12 to 17, wherein said toner containing portion (10a) is provided with toner discharge opening (12g) through which the toner is supplied out of said toner containing portion toward said developing member, and said supporting portion (31b) is provided at the position deviated from the center or centroid toward said toner discharge opening. A process cartridge according to claim 12, wherein said range contains a longitudinal extension of said toner supply opening. A process cartridge according to claim 12, wherein a second opening (12i) is provided in a longitudinal end portion opposite from said longitudinal end portion having said toner supply opening and is capable of supporting the other end portion (31a1) of said stirring member (31a). A process cartridge according to claim 12, wherein a center of said supporting portion (31b) is deviated approx. 2-10 mm from the center (31c1) of said toner supply opening. A process cartridge according to claim 12, wherein said stirring member (31a) including, at its central part, a pin portion (31a4) offset in a radial direction from its axis of rotation. A process cartridge (B) detachably mountable relative to a main assembly (A) of an image forming apparatus, comprising: (a) an electrophotographic photosensitive member (7); (b) a developing member (10d) for developing a latent image formed on said electrophotographic photosensitive member; (c) a toner frame (12e) including: a toner containing portion (10a) for containing toner to be supplied to said developing member; a toner supply opening (32) for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion of said toner containing portion; a removable sealing member (33) for sealing said toner supply opening (32), said sealing member supporting one end portion (10i) of a stirring member (31a) for stirring toner contained in said toner containing portion, at a position which is within a range of said toner supply opening (32) and is deviated from a center or centroid of said toner supply opening, as seen in a longitudinal direction of said toner frame. A process cartridge according to claim 23, further comprising a feeding member (10b2) which further stirs and feeds the toner stirred and fed by said stirring member. A process cartridge according to any of claims 12 to claim 24, further comprising at least one of a charging member (8) for charging said electrophotographic photosensitive member and a cleaning member (11a) for removing residual toner from said photosensitive member. An electrophotographic image forming apparatus for forming an image on a recording material (2), comprising: mounting means for detachably mounting a process cartridge (B), said process cartridge including: (a) an electrophotographic photosensitive member (7); (b) a developing member (10d) for developing a latent image formed on said electrophotographic photosensitive member; (c) a toner frame (12e) including: a toner containing portion (10a) for containing toner to be supplied to said developing member; a toner supply opening (32) for supplying the toner into said toner containing portion, wherein said toner supply opening is provided in a longitudinal end portion of said toner containing portion; and a supporting portion (31b) supporting one end portion (31a3) of a stirring member (10b1,31a) for stirring toner contained in said toner containing portion, wherein said supporting portion is disposed within a range of said toner supply opening and at a position deviated from a center or centroid of said toner supply opening, as seen in a longitudinal direction of said toner frame; and (d) feeding means (3,4) for feeding the recording material (2).

Inventors: BATORI YOSHIYUKI, SATO MINORU, YOKOI AKIYOSHI, BATORI, YOSHIYUKI, SATO, MINORU, YOKOI, AKIYOSHI
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1998
Main classification: G03G21
IPC codes: G03G15