Sealing member, process cartridge and developer supply container

Abstract: A sealing member for sealing a developer accommodating portion for accommodating a developer includes (a) a sealing portion for openably sealing an opening of said developer accommodating portion; (b) an extended portion extended from said sealing portion, said extended portion having a width, measured in a direction of extension, which is smaller than that of said sealing portion; (c) a connecting edge for connecting an edge of said sealing portion adjacent said extended portion and a side edge of said extended portion extending in the direction of the extension; (d) a tearable portion capable of being torn to open said opening sealed by said sealing portion, wherein an end of said tearable portion is provided in said sealing portion, and the other end thereof continues to said connecting edge, wherein said tearable portion extends between said one end and said other end substantially parallel with the extension direction.

Description: FIELD OF THE INVENTION AND RELATED ART The present invention relates to a sealing member for sealing a developer accommodating portion for accommodating a developer, a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, using the sealing member, and a developer supply container for supplying the developer into a main assembly of an electrophotographic image forming apparatus using the sealing member. Here, the electrophotographic image forming apparatus means the one which forms images on recording materials using an electrophotographic image formation type. Examples of the electrophotographic image forming apparatus include an electrophotographic copying machine, an electrophotographic printer (laser beam printer, LED printer or the like), a facsimile machine and a word processor. The process cartridge is a cartridge having as a unit an electrophotographic photosensitive member, and at least one of charging means for charging the electrophotographic photosensitive member, developing means for developing the latent image formed on the electrophotographic photosensitive member and cleaning means for removing a developer remaining on the electrophotographic photosensitive member, the cartridge being detachably mountable relative to a main assembly of the electrophotographic image forming apparatus. In an electrophotographic image forming apparatus using an electrophotographic image forming process, the process cartridge type is known. The process cartridge type is advantageous in that maintenance of the apparatus can be in effect carried out by the users, and therefore, the operativity is remarkably improved. For this reason, the process cartridge type is widely used in the field of the image forming apparatus. A developing device used in the process cartridge, comprises a toner accommodating container having an opening sealed by a sealing member, and a developing container coupled therewith. When the process cartridge is used, the user tears the sealing member to open the toner accommodating container. The toner is supplied to the developing container from the toner accommodating container through the opening thus opened. Examples the sealing member include a so-called easy peel film which is one film to be removed upon start of use, and a so-called tear tape or an integral cover film having a tearable portion, wherein the tearable portion is torn out of the cover film upon the start of use. The tear tape sealing is recently widely used since the force required for unsealing or opening is small. Use of tearable sealing member has been proposed in for example, Japanese Laid-open Patent Application No. SHO- 59-13262 and Japanese Laid-open Utility Model Application No. SHO- 63-60164. Furthermore, a proposal has been made as to avoiding oblique pulling upon unsealing. For example, U. S. Patent No. 5752131(Japanese Laid-open Patent Application No. HEI- 7-13422) discloses a regulating member for regulating the seal pulling direction. As another example, U. S. Patent No. 5689772 (Japanese Laid-open Patent Application No. HEI- 8-030170) discloses that seal pulling direction is regulated by the toner container and the developing container. Japanese Laid-open Patent Application No. HEI- 8-305257, discloses a seal draw-out opening is effective to regulate the seal pulling direction. Another example of relevant prior art is disclosed in U.S Patent No. 5 177 540. The inventors of the present invention have sought to provide a sealing member which can be assuredly teared and smoothly torn. In accordance with the present invention there is provided a sealing member for sealing a developer accommodating portion for accommodating a developer, comprising (a) a sealing portion for openably sealing an opening of said developer accommodating portion; (b) an extended portion extended from said sealing portion, said extended portion having a width, measured in a direction perpendicular to a direction of extension, which is smaller than that of said sealing portion; (c) connecting edge for connecting an edge of said sealing portion adjacent said extended portion and each side edge of said extended portion extending in the direction of the extension; and (d) easy-tear portions for opening said opening sealed by said sealing portion, wherein an end of each said easy-tear portion is provided in said sealing portion, and the other end thereof continues to said connecting edges, wherein each said easy-tear portion extends between said one end and said other end substantially parallel with the extension direction at a position laterally outside extension lines of the side edges of said extended portion. There is also provided hereby a process cartridge and a developer supply container using such a sealing member. These features and also those further features and the advantages of the present invention and its modifications as set out in the appended claims, 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 sectional view of a toner seal according to an embodiment of the present invention. Figure 2 is a perspective view of a toner seal. Figure 3 is a perspective view illustrating toner seal and a toner accommodating container. Figure 4 is a top plan view illustrating a heat seal pattern. Figure 5 is a top plan view illustrating the heat seal pattern. Figure 6 is a top plan view illustrating the positional relation of the heat seal pattern. Figure 7 is a perspective view illustrating the combination of a developing container and a toner accommodating container. Figure 8 is a sectional view of a seal draw-out opening. Figure 9 is a top plan view of a free end portion of the toner seal. Figure 10 is a top plan view of a free end portion of the toner seal. Figure 11 is a top plan view of a free end portion of the toner seal. Figure 12 is a top plan view of a free end portion of the toner seal. Figure 13 is a top plan view of a free end portion of the toner seal. Figure 14 is a perspective view illustrating combination of a developing container and a toner accommodating container and illustrating an engagement guide. Figure 15 is a perspective view of a toner container provided with a seal draw-out opening. Figure 16 is a longitudinal sectional view illustrating a structure of an image forming apparatus to which a process cartridge is mounted. Figure 17 is a longitudinal sectional view illustrating a structure of a process cartridge. Figure 18 is a perspective view illustrating a mounting structure of the process cartridge. Figure 19 is a perspective view illustrating a mounting structure of the process cartridge. Figure 20 is a top plan view illustrating a free end portion of the toner seal. Figure 21 is a top plan view of a free end portion of the toner seal. Figure 22 is a sectional view of a toner seal. Figure 23 is a perspective view of a developer supply container provided with a sealing member. DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the accompanying drawings, the embodiments of the present invention will be described using an exemplary electrophotographic image forming apparatus to which a process cartridge including a developing device is mountable. Embodiment 1 (GENERAL ARRANGEMENT) In the electrophotographic image forming apparatus A, as shown in Figure 16, a latent image is formed on a photosensitive drum 7 (image bearing member) by projection of a laser beam image from an optical system 1 in accordance with image information, and is development with toner into a toner image. In synchronism with formation of the toner image, a recording material 2 is fed our of a cassette 3a by feeding means 3 including a pick-up roller 3b, feeding rollers 3c, feeding rollers 3d, and registration rollers 3e. The toner image formed on the photosensitive drum in the process cartridge B is transfer onto the recording material 2 by voltage application to a transfer roller 4 as transferring means in the apparatus A. The recording material 2 is fed to fixing means along a guide plate 3f. The fixing means 5 comprises a driving roller 5a and a fixing roller 5c having therein a heater 5b to apply the heat and the pressure to the recording material 2 passing therethrough. The recording material 2 is fed by a couple of discharging rollers 3g, 3h and is discharged to a discharging portion 6 through a reverse feeding path. The image forming apparatus A is provided with a manual insertion tray 3i and rollers 3j for permitting manual insertion feeding. On the other hand, the process cartridge B, as shown in Figure 17, the photosensitive drum 7 having a photosensitive layer is rotated, and the surface thereof is uniformly charged by voltage application to the charging roller 8 (charging means). A light image is projected from the optical system 1 through an opening 9 onto the photosensitive drum 7 to form a latent image, which is in turn developed by developing means 10. The developing means 10 feeds the toner from the toner accommodating portion by rotation of the toner feeding member, and rotates the developing roller 10c which contains therein a fixed magnet 10b. By this, a layer of the toner triboelectrically charged by the developing blade 10d is formed on the surface of the developing roller 10c, and the toner is supplied to the photosensitive drum 7 in accordance with the latent image to form the toner image(visual image). Then, the transfer roller 4 is supplied with a voltage having an opposite polarity from the toner image to transfer the toner image onto the recording material 2. Thereafter, the toner remaining on the photosensitive drum 7 is removed by a cleaning blade 11a of cleaning means 11, and is received by a receptor sheet 11b and then a residual toner container 11c of the cleaning means 11. A frame for the developing device is constituted by a toner accommodating container 12a accommodating the toner and a developing frame 12b for supporting the developing member such as a developing roller 10c, which are welded with each other. The cartridge B is constituted by coupling a cleaner container 12c supporting the photosensitive drum 7, the cleaning blade 11a and the charging roller 8, with the integral developing device frame. The process cartridge B is detachably mountably mounted to cartridge mounting means provided in the main assembly 13 of the apparatus. In the cartridge mounting means, when an openable member 15 provided in the main assembly A of the apparatus is opened by rotation about a shaft 14, cartridge guiding members 16 are mounted opposing to each other on the left and right inner surfaces in a cartridge mounting space, as shown in Figures 18 and 19. The left and right guiding members 16 are provided with opposing guide portions 16a which function as a guide when the process cartridge B is inserted. The process cartridge B is mounted to the image forming apparatus A by inserting the process cartridge B along the guide portions 16a and then closing the openable member 15. By such mounting, a drum gear(unshown) mounted to a longitudinal end portion of the photosensitive drum 7 is brought into meshing engagement with a drive transmission gear G (Figure 19) provided in the main assembly 13 of the apparatus to enable driving force transmission to the photosensitive drum 7. (Coupling structure between the toner container and the developing frame) The description will be made for a coupling structure between the developing frame 12b and the toner container 12a constituting the frame of the developing device. As shown in Figure 3, the toner accommodating container 12a is provided with an opening 12a1. A flange 12a2 is formed around the opening 12a1. The opening 12a1 is openably sealed by a tearable seal member 17 (sealing member) The seal member 17, as shown in Figure 3, has a cover seal portion 17a (sealing portion) mounted by heat seal to the flange 12a2 to hermetically close the opening 12a1. The seal member 17 is provided with a drawing portion 17b in the form of an extended portion extended from the cover seal portion 17a. The cover seal portion 17a and the drawing portion 17b are constituted by a single sheet and are folded back and overlapped to constitute the seal member 17. The drawing portion 17b has a mechanical strength sufficient to permit the cover seal portion 17a to be torn. As shown in Figures 3, 7, the tearable seal member 17 is stuck or pasted on the flange 12a2 around the opening 12a1. A welded portion W2 is provided extended in the longitudinal direction at each side of the seal member 17. The developing frame 12b has parallel welding ribs (unshown) welded by ultrasonic welding in contact with the welded portion W2 of the toner accommodating container 12a. After the toner accommodating container 12a and the developing frame are welded, the welding rib are positioned at each side of the seal member 17. The toner accommodating container has a gap between the toner accommodating container 12a and the developing frame 12b. The welding rib is a projection having a triangular section. Upon the vibration welding, the section of the welding rib is substantially rectangular. At the longitudinal opposite ends of the gap between the toner accommodating container 12a and the developing frame 12b, there are seal members 19, 20 of elastic material such as polyurethane foam for plugging the container gap, which are mounted to the developing frame 12b. The seal member 20 at one end presses against the drawing portion 17b of the seal member 17 to the toner accommodating container 12a. As shown in Figures 1 and 2, the seal member 17 of the present invention comprises a surface layer 31a, a laser blocking layer 31b for blocking a laser beam, a guide layer 31c which is usable by laser beam and a sealant layer 31d for welding the sealing member, in the order named in the direction of its thickness. The surface layer 31a is of biaxial orientation polyester film (PET). The thickness thereof is preferably 10µm-20µm, and further preferably is 12µm-17µm to maximize the heat sealing condition when it is mounted to the toner accommodating container 12a, and to assure the tearability while maintaining the easy tearing property. The surface layer 31a of the tearable seal member 17, is of biaxial orientation polyester film (PET) having a thickness of approx. 12µm. The laser blocking layer 31b is of aluminum foil since it does not absorb the laser blocking layer 31b beam energy, and since it can assuredly avoid deterioration of the film strength of the surface layer 31a due to crystallization by radiation heat upon heat fusing of the guide layer 31c when the carbon oxide gas laser R is applied to the sealant layer 31d side. The thickness of the aluminum foil is preferably 5µm-15µm, and further preferably 7µm-12µm, and in this embodiment, it is approx. 7µm. Guide layer 31c is of biaxial orientation polyester film (PET). The guide layer 31c absorbs the carbon oxide gas laser R energy to fuse by the continuous projection of the laser beam thereto at the laser projecting portion 31c1. It should not absorb so much laser energy as to damage the sealant layer 31d, while permitting speedy laser machining. For this reason, it has preferably a thickness of 40µm-70µm, and further preferably 40µm-60µm, and in this embodiment, it is approx. 50µm. The material of sealant layer 31d is ethylene= vinylacetate copolymer resin material (EVA) since it has sufficient heat sealing property and bonding strength. The thickness of the sealant layer 31d is preferably 40µm-70µm. Further preferably, it is 40µm-60µm, and is approx. 50µm in this embodiment. The sealant content ratio of the vinylacetate copolymer resin material (VA) in the sealant layer 31d is not more than 10wt.%, and the molecular weight distribution(gel permeation) of the ethylene= vinylacetate copolymer resin material does not have a local minimum in the range less than 100,000 of the molecular weight but has at least one local minimum in the range not less than 100,000 thereof. This is because then such a trouble can be avoided that sealant layer 31d is stuck (blocking) under a high temperature and high humidity ambience on the seal member 19 at a side where the drawing portion 17b of the seal member 17 is projected to prevent unsealing, after the toner accommodating container 12a is coupled with the developing frame 12b, The laser is applied on the sealant layer 31d side of the seal member 17 to fuse at least one layer of the seal member 17 to form a cavity. For example, as shown in Figure 1, the guide layer 31c is fused to form the cavity 31c1, or as shown in Figure 22, the guide layer 31c and the sealant layer 31d are fused to provide a cavity 31c2 having an opening 31e. Along the cavity or cavities, a tearable portion 17c is formed to permit the opening 12a1 to be opened. The cavity may be formed by cutting a part of the seal member. Alternately, formation of fine perforations is usable to provide the tearable portion 17c. The layers from the surface layer to the sealant layer 31d, inclusive, are bonded by dry lamination. In this embodiment, the film thickness after the dry lamination is 128µm. The developing device of this embodiment includes a toner accommodating container 12a having an opening 12a1. It also includes the seal member 17, having the integral cover seal portion 17a and the drawing portion 17b, for sealing the opening 12a1 and permitting unsealing upon the start of use. The width L1 of the drawing portion 17b of the seal member 17 is narrower than the distance or interval L2 between the two tearable portions 17c. In a boundary region between the cover seal portion 17a and the drawing portion 17b, there is formed an edge portion 17e as a connecting portion where the width L5 reduced from the cover seal portion 17a to the drawing portion 17b, and to the connecting portion, the tearable portion 17c extends. The edge portion 17e and the tearable portion 17c cross with each other inclinedly at the end. As shown in Figures 2 and 9, the seal member 17 has the drawing portion 17b with a free end, and the cover seal member 17a. Ideally, it continuously extends from each edge 17b1 of the drawing portion 17b to the tearable portion (half cut portion) 17c which extends along the laser projected portion (cavity portion) 31c1. However, from the standpoint of the accuracy in the punching in the seal manufacturing (outer configuration), some tolerance is to be provided. For example, if the half cut portion results in being formed inside the drawing portion 17b at the free end, there is a liability that as shown in Figure 13, the film cutting 17f may starts at the edge portion 17e (extension of the edge 17b1 at each side of the drawing portion 17b). Therefore, it is preferable that width of the drawing portion 17b (free end) is slightly smaller than the distance between the two tearable portions 17c. As shown in Figures 2, 9, the width L1 of the drawing portions 17b is narrower than the distance L2 (= the width of the laser projecting portion 31c1) between the two linear tearable portions 17c. In this embodiment, the width L1 of the drawing portions 17b is approx. 32mm, 2, and the distance L2 between the tearable portions 17c is approx. 34mm so that the difference between L1 and L2 is approx. 1mm at each side. As shown in Figure 10, the configuration of the edge portion 17e where tearing end comes, is arcuated to permit smooth tearing. Tearing stability is to be taken into consideration, that is, the tearing is assured by concentrating the stress at the end of the tearing portion 17c. Also, the pulling stability is to be taken into account, that is, the film is not broken at the edge portion 17e while maintaining the smooth continuous drawing operativity during the manufacturing drawing process of the seal member 17. In view of these factors, the edge portion 17e is arcuated, and the radius R thereof is preferably 1-2.5mm, and further preferably is it 1.5-2mm, and it is approx. 2mm in this embodiment. If the radius R is too large, the stress is not sufficiently concentrated on the portion 17c, and therefore, the tearing property is not good, and if it is too small, the continuous drawing processing is difficult. The arcuated edge portion 17e continues to the edge 17b1 of the drawing portion 17b. In this example, the edge portion 17e also continues to the end 17a1 of the boundary region relative to the drawing portion 17b of the cover seal portion 17a. One end of the tearable portion 17c provided along the laser projecting portion 31c1 (said laser-machined portion) continues to the arcuated portion of the edge portion 17e. In this example, the edge configuration 17e is rounded, and the laser projecting portion 31c1 is disposed approx. 1mm outside the edge 17b1 of the drawing portion 17b. The position of the laser projecting portion 31c1 is liable to be deviated due to the manufacturing tolerance, and if it is deviated outwardly or inwardly, the stress concentration onto the laser projecting portion 31c1 is weakened with the result of difficulty in tearing. The distance L2 between the tearable portion 17c provided by the laser machining corresponding to the opening 12a1 of the toner accommodating container 12a is larger than the width L1 of the drawing portions 17b (free end portions). However, when it is torn in combination with the seal pattern 33 which will be described hereinafter, it is not torn at a position out of the tearing portion 17c at the edge portion 17e. Figures 4, 6 show the portions where the cover seal portion 17a is mounted to the flange 12a2 of the toner accommodating container 12a. In Figure 4, the zone of the hatched lines extending from upper left to the lower right, and in Figure 6 the zone of the hatched lines extending from the upper right to the lower left are portions (seal pattern) on which the cover seal portion 17a is mounted by heat seal. A horn-like pattern 33b is provided at each of the edge portions 17e. A L-shaped seal pattern 33a is provided so as to connect the horn-like patterns 33b. Another L-shaped seal pattern 33c is provided at the opposite longitudinal end. At the end portion, the horn-like pattern 33b function to prevent the seal from being torn along a line out of the guide 17c, thus accomplishing stable tearing. Figure 5 shows a case in which the opening 12a1 is not at the central portion of the toner accommodating container 12a, that is, the seal pattern 33 is such that cover seal portions 17a are not symmetrical as seen in the drawing direction of the seal member 17. In such a case, the horn-like pattern 33b is effective to prevent the edge portion 17e from being torn out of the position of the portion 17c. The distance L4 between the left and right inner edges 33d of the seal pattern 33 having the horn-like pattern, may be smaller than the distance L2 between the two tearable portions 17c, but is preferably larger than that. Distances L3 and L3' between the tearable portion 17c and the inner edge 33d of the seal pattern, is preferably larger than a predetermined distance from the standpoint of the tearing stability of the seal member 17, more particularly, it is not less than 0.5mm. Further desirably, it is not less than 1mm. The description will be made as to the tearing stability. When the inner edge 33d of the seal pattern 33 overlaps the laser projecting portion 31c1 of the guide layer, the laser projecting portion 31c1 of the guide layer receives additional heat and the pressure during the heat seal. By making the distance L4 between the left and right inner edges 33d of the seal pattern 33 larger than the distance L2 between the two tearable portions 17c, it can be avoided with certainty that deterioration due to the laser projecting portion 31c1 of the guide layer results in occurrence of the peeling away from the guide or in the occurrence of peeling between the layers of the film. In this embodiment, from this standpoint, the distances L3 and L3' between the laser projecting portion 31c1 of the guide layer and the inner edge 33d of the seal pattern, is approx. 1mm and approx. 1.5mm. The seal member 17 manufactured so as to satisfy the above, has been actually mounted by heat sealing on the toner accommodating container 12a provided with the toner feeding member 10a (Figure 17) as shown in Figure 3. The laser machining device for the seal member 17 is of a water cooling type carbon oxide laser and produces a laser beam having a wavelength of 10.6µm at the output of approx. 8W, wherein the laser spot diameter is approx.0.1mm, and the laser machining speed is approx. 12m/ min., and the film distance between the laser beam generation end and the film distance is approx. 38.6mm. The toner accommodating container 12a has been injection-molded from shock resistant polystyrene (HIPS), and the opening 12a1 is approx. 30mm in width, approx. 210mm in length, and the inside volume is approx. 460cc. The seal member 17 has a surface layer having a thickness of approx. 12µm (biaxial orientation polyester PET). Therefore, a wide range of seal condition is available, such as the heat sealing temperature of 130°C-180°C, the seal pressure of 4kgf/cm 2 -7kgf/cm 2 (cylinder bore diameter of 100), and the sealing period of 2-5sec approx. In this embodiment, the seal temperature was approx. 180°C, the seal pressure was approx. 4kgf/cm 2 , and the seal time was approx. 3sec. The seal pattern was as shown in Figures 4 and 6 (seal pattern 33), and the seal width was approx. 3mm along the entire circumference, including the horn-like pattern 33b portions. The toner accommodating container 12a manufactured in this manner was coupled with the developing frame 12b, as shown in Figure 7, to produce a developing device 10. The drawing portion 17b at the free end of the seal member 17 folded back is extended out of the draw-out opening. A developing frame 12b to which the seal members 19, 20 of polyurethane foam are bonded at the leading and trailing end portions, is welded thereto by ultrasonic welding along the entire length at both of the sides only. The seal members 19, 20 are of polyurethane foam (foamed into approx. 18 times) having thickness of the approx. 2mm, and is collapsed to approx. 1mm between the toner accommodating container 12a and the developing frame 12b after the welding to assure the seal property after the unsealing. At the draw-out opening, as shown in Figures 7, 8, the developing frame 12b is provided with a regulating member 21 for regulating the drawing direction of the seal, which is known by Japanese Laid-open Patent Application No. HEI- 7-13422. The regulating member 21 may be provided on the developing frame 12b. The inner distance L5 of the direction regulating members 21 is slightly larger than the distance of the tearable portions 17c of the toner seal. At the initial stage of the unsealing the drawing portion 17b having the width L1 is pulled. However, with the unsealing action continued, the portion torn out of the cover seal portion 17a and having the width substantially the same as the width L2 of the tearable portion, is drawn out (width becomes larger). In order to properly regulate the direction of the smooth tearing at the edge portion 17e, it is desirable that the distance between the two regulating members 21, that is, the width L5 at the seal draw-out opening is larger than the width L2 of the tearable portion 17c by not less than 0.1mm and less than 2mm at one side. Further desirably, it is wider by not less than 1mm and not more than 1.5mm at one side. With the developing device 10 manufactured in the manner described in the foregoing, the smoothness of the seal pulling at the seal draw-out opening, the operativity, the tearing stability and the withstand pressure property have been checked. The developing device 10 was fixed, and seal was pulled straight in the direction of approx. 180° at a pulling speed of 5000mm/ min. Approx. in one case, and it was pulled obliquely at about 10°, which may occur in actual situations in the other case; and the smoothness of pulling, the unsealing strength, the stability of the opened width (widening) were checked. For the withstand pressure property check, the toner accommodating container 12a was filled with approx. 250g of the one component magnetic toner having the average particle diameter of approx. 7µm, and it was let fall with the seal surface faced down from predetermined levels to check the impact acceleration (so-called "9") at which the seal was removed or broken. The level at which it was let fall was raised to determine the limit acceleration (9) without the seal removal or breakage. As a result, the seal was smoothly pulled until the opening of the toner supply opening without clogging at the seal draw-out opening both when the seal was pulled straight or when it was pulled obliquely. As regards the operativity, the peeling strength is approx. 3kgf which is good. As regards the tearing stability, the seal was teared along the tearable portions 17c, and stabilized widths of the opening were provided. No peeling was observed between layers. The withstand pressure acceleration was as large as 150g which is sufficient. (Embodiment 2) The toner accommodating container 12a and the developing device 10 of this embodiment has the same structures as with Embodiment 1 except that configuration of the edge portion 17e to which the tearable end of the seal member 17 reaches is inclined line configuration (rectilinear configuration), as shown in Figure 11. A complementary angle  between the edge 17b1 of the drawing portion 17b and the edge portion 17e is desirably approx. 30°-60° to permit smooth unsealing. The angle  is more particularly the angle formed between the portion 17e1 of the boundary portion in the portion to remain and the end 17a1 of the cover seal portion 17a. When the angle  is less than 30° or not less than 60°, the configuration at the edge portion 17e is close to a perpendicular. When the angle  is less than 30°, the configuration is more like the one as shown in Figure 12. When the angle  is not less than 60°, the configuration is as shown in Figure 21, and the stress does not concentrate on the portion 17c, so that tearing stability is not enough. In this embodiment, as shown in Figure 11, the angle  is approx. 45°, and the size 17c1x of the hatched portion of the edge portion 17e is approx. 1mm. As regards the position of the portion 17c indicated by the hatched portions, the distance 17e2x between 17c and 17b1 is approx.0.5mm so that it is located substantially at the center of the hatched portion 17c. In this example, similarly to Embodiment 1, the manufacturing tolerance is necessary, but because of the location at the center of the hatched portion 17c, inner or outer deviation would not result in the departure from the hatched portion 17c. As a result, the film end can be pulled at a constant angle at all times, and therefore, the tearing stability is higher than in Embodiment 1 using rounded configuration. The size of the hatched portion 17e is desirably as small as possible provided that tearing portion 17c is not out of the hatched portion 17c even in view of the manufacturing tolerance of the seal, more particularly, it is desirably not more than 2mm and not more than 1mm. The smaller the hatched portion 17c is, the more the stress is concentrated on the portion 17c upon the unsealing, thus improving the easy tearing property. As regards the position of the guide 17c in the hatched portion 17e, the distance between 17b1 and 17c is desirably as large as possible (closer to the 17g (intersection between 17e and 17a1 in Figure 11)), provided that guide 17c is not out of the hatched portion 17c in view of the film deviation due to the manufacturing tolerances of the seal. This is because then the stress tends to concentrate, and therefore, the easy tearing is improved. In this example, the stress concentration is sufficient even when the easy tearing property of the film per se is poor due to variations of the material, the thickness, the lamination strengths between layers of the film. Even when the tearing does not occur at the portion 17c, the seal is torn at the position 17g as shown in Figure 20, and the tearing portion comes immediately to 17c. With the developing device 10 manufactured in the manner described in the foregoing, the smoothness of the seal pulling at the seal draw-out opening, the operativity, the tearing stability and the withstand pressure property have been checked, as in Embodiment 1. As a result, the seal was smoothly pulled until the opening of the toner supply opening without clogging at the seal draw-out opening both when the seal was pulled straight or when it was pulled obliquely. As regards the operativity, the peeling strength is approx. 3kgf which is good. As regards the tearing stability, the seal was teared along the tearable portions 17c, and stabilized widths of the opening were provided. No peeling was observed between layers. The withstand pressure acceleration was as large as 150g which is sufficient. (Embodiment 3) In the foregoing embodiments, a regulating member 21 is particularly provided, but in this embodiment, an engagement guide for the engagement between the toner accommodating container 12a and the developing frame 12b is used as the regulating member for regulating the seal drawing direction. This embodiment is the same as Embodiment 1 in the other respect. As shown in figure 14, the engagement guide comprises an outer wall member 12a4 projected integrally from the toner accommodating container 12a, a guide projection 12b3 integral with the developing frame 12b, and a lightening recess of the toner accommodating container 12a engaging with the guide projection 12b3. The outer wall member 12a4 has an end which is bent toward the edge 17b1 of the drawing portion 17b. The guide projection 12b3 and the recess 12a5 function as an engagement guide when the toner accommodating container 12a and the developing frame 12b are coupled with each other, and the outer wall member 12a4 and the guide projection 12b3 function to regulate the seal drawing direction when the seal is removed. With the developing device 10 manufactured in the manner described in the foregoing, the smoothness of the seal pulling at the seal draw-out opening, the operativity, the tearing stability and the withstand pressure property have been checked, as in Embodiment 1. As a result, the seal was smoothly pulled until the opening of the toner supply opening without clogging at the seal draw-out opening both when the seal was pulled straight or when it was pulled obliquely. As regards the operativity, the peeling strength is approx. 3kgf which is good. As regards the tearing stability, the seal was teared along the tearable portions 17c, and stabilized widths of the opening were provided. No peeling was observed between layers. The withstand pressure acceleration was as large as 150g which is sufficient. (Embodiment 4) In this embodiment, the regulating member is not used, either, but a seal draw-out opening 23 capable of regulating the seal pulling direction is integrally provided in the toner accommodating container 12a, as in Figure 15. The drawing portion 17b at the free end of the seal member 17 is inserted into the seal draw-out opening 23. In the other respects, this embodiment is the same as in the Embodiment 1. The section of the seal draw-out opening 23 is such that long side thereof is slightly larger than the width of the portion 17c, and the short side is slightly larger than the thickness of the seal member 17. It penetrates in the drawing direction of the seal member 17. The draw-out opening 23 is disposed downstream of the seal member 19 between the container, in the drawing direction of the seal member 17. With the developing device 10 manufactured in the manner described in the foregoing, the smoothness of the seal pulling at the seal draw-out opening, the operativity, the tearing stability and the withstand pressure property have been checked, similarly to Embodiment 1. As a result, the seal was smoothly pulled until the opening of the toner supply opening without clogging at the seal draw-out opening both when the seal was pulled straight or when it was pulled obliquely. As regards the operativity, the peeling strength is approx. 3kgf which is good. As regards the tearing stability, the seal was teared along the tearable portions 17c, and stabilized widths of the opening were provided. No peeling was observed between layers. The withstand pressure acceleration was as large as 150g which is sufficient. (Embodiment 5) In this embodiment, the tearable seal member 17 is used for a developer supply container 50 for supplying the developer into the electrophotographic image forming apparatus. When the developer in the main assembly of the apparatus is consumed, the operator tears the seal member 17 to unseal the opening 50a by which the developer is supplied into a developer receiving portion (unshown) of the main assembly. The operativity, the tearing stability and the withstand pressure property are checked. As a result, the opening 50a was smoothly opened. As regards the operativity, the peeling strength is approx. 3kgf which is good. As regards the tearing stability, the tape was torn along the portion 17c, and the provided opening width was stable. No peeling was observed between layers. As described in the foregoing, according to the embodiments of the present invention, the sealing member can be assuredly removed. Furthermore, the sealing member can be smoothly removed. Moreover, the present invention provides a process cartridge and a developer supply container using such a sealing member. 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 sealing member (17) for sealing a developer accommodating portion (12a) for accommodating a developer, comprising: (a) a sealing portion (17a) for openably sealing an opening (12a1) of said developer accommodating portion (12a); (b) an extended portion (17b) extending from said sealing portion (17a), said extended portion (17b) having a width (L1), measured in a direction perpendicular to a direction of extension, which is smaller than that of said sealing portion; (c) connecting edges (17e) for connecting an edge of said sealing portion (17a) adjacent said extended portion (17b) and each side edge (17b1) of said extended portion (17b) extending in the direction of the extension; and (d) easy-tear portions (17c) for opening said opening (12a1) sealed by said sealing portion (17a), wherein an end of each said easy-tear portion (17c) is provided in said sealing portion (17a), and the other end thereof continues to said connecting edges (17e), wherein each said easy-tear portion (17c) extends between said one end and said other end substantially parallel with the extension direction at a position laterally outside extension lines of the side edges (17b1) of said extended portion (17b). A sealing member according to claim 1, wherein said sealing member (17) is provided with cavities (31c1) in a direction of a thickness thereof, along the easy-tear portions (17c). A sealing member according to claim 2, wherein said sealing member (17) has a multi-layer structure comprising a surface layer (31a), a laser beam blocking layer (31b) for blocking a laser beam (R), a fusible layer (31c) fusible by the laser beam (R), and a sealant layer (31d) for bonding said sealing member around said opening (12a1), in the order named in the direction of the thickness, wherein said cavities (31c1) are provided by partly fusing the fusible layer (31c) by the laser beam (R). A sealing member according to claim 2, wherein said sealing member (17) has a multi-layer structure comprising a surface layer (31a), a laser beam blocking layer (31b) for blocking a laser beam (R), a fusible layer (31c) fusible by the laser beam (R), and a sealant layer (31d) for bonding said sealing member around said opening (12a1), in the order named in the direction of the thickness, wherein said cavities (31c1) are provided in the fusible layer (31c) through the sealant layer (31d) by partly fusing the fusible layer and the sealant layer by the laser beam (R). A sealing member according to claim 1, wherein said connecting edge (17e) is arcuately concave toward the inside. A sealing member according to claim 1, wherein said connecting edge (17e) is linearly inclined relative to the extension direction. A sealing member according to claim 1, wherein said developer accommodating portion (12a) is provided in a developer supply container (50) for supplying the developer into a main assembly (A) of an electrophotographic image forming apparatus. A sealing member according to claim 1, wherein said developer accommodating portion (12a) is provided in a process cartridge (B) which is detachably mountable relative to a main assembly (A) of an electrophotographic image forming apparatus, the process cartridge containing as a unit an electrophotographic photosensitive member (7), and process means (8,11,10) actable on said electrophotographic photosensitive member. A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus, comprising: (a) an electrophotographic photosensitive member; (b) process means actable on said electrophotographic photosensitive member; (c) a developer accommodating portion for accommodating a developer; and (d) a sealing member for sealing said developer accommodating portion, being a sealing member in accordance with any one of the preceding claims 1-6. A process cartridge according to claim 9, wherein said process means is one of charging means (8) for charging said electrophotographic photosensitive member, developing means (10) for developing a latent image formed on the electrophotographic photosensitive member, and cleaning means (11) for removing the developer remaining on said electrophotographic photosensitive member. A developer supply container for supplying a developer to a main assembly of an electrophotographic image forming apparatus, comprising: (a) a developer accommodating portion for accommodating a developer; and (b) a sealing member for sealing said developer accommodating portion, said sealing member being a sealing member in accordance with any one of the preceding claims 1-6.

Inventors: FUJIWARA YASUO, MORINAGA HIROUMI, NAGASHIMA TOSHIAKI, FUJIWARA, YASUO, MORINAGA, HIROUMI, NAGASHIMA, TOSHIAKI
Applicants: CANON KK, CANON KABUSHIKI KAISHA
Application year: 1998
Main classification: G03G15
IPC codes: G03G15