Mechanism for opening/closing a toner falling aperture

Abstract: A mechanism for opening/closing a toner falling aperture is adapted to open/close a toner falling aperture (TC2) formed in the bottom of a toner cartridge main body (T1) in which toner is housed. Disposed inside of the toner cartridge main body (T1) is a screw conveyor (SC) for conveying the toner to the toner falling aperture. While the toner cartridge is not under use, an elastic sealing member (S) attached to the top surface of the bottom (TC1) of the toner cartridge main body (T1), closes the toner falling aperture (TC2). One end of the sealing member (S) is secured to the screw conveyor (SC). When the toner cartridge is set to a predetermined portion of the main body of an image forming apparatus and the screw conveyor (SC) is driven, the screw conveyor takes up the sealing member (S) while winding the same thereon, thus opening the toner falling aperture (TC2). The sealing member (S) to which toner is sticked, is taken up by the screw conveyor (SC) and held inside of the toner cartridge main body (T1).

Description: The present invention relates to a mechanism for opening/closing a toner falling aperture through which toner is supplied from a toner cartridge to the developing device in an image forming apparatus such as an electrostatic copying apparatus, a facsimile, a laser beam printer or the like. In an image forming apparatus as above-mentioned, a toner cartridge is removably attached to a housing in the main body of the image forming apparatus. A toner cartridge of which toner has been used up, is to be replaced with a new toner cartridge. In particular, the invention relates to a mechanism for closing/opening a toner falling aperture formed in the bottom of the main body of a toner cartridge in which toner is housed, wherein an elastic sealing member is removably attached to the bottom of the toner cartridge main body for closing the toner falling aperture and wherein rotatable means are disposed inside of the toner cartridge main body to which the elastic sealing member is secured and which are adapted to take off the elastic sealing member when rotated. Such a mechanism is known from the document JP-A-62-50862. In the conventional mechanism, rotatable means are provided comprising a shaft, a rotary frame piece and a flexible tape, which are provided only for the purpose of removing a temporary fixing seal tape from an opening provided in a wall of the toner container. In the conventional mechanism, the flexible tape is fixed to the rotary frame piece on the one hand and to an external edge of a discharge port on the other hand. The rotatable means are adapted to make a limited rotary movement until the flexible tape has been removed from the opening and drawn into the interior of the cartridge, wherein part of the fixing seal tape remains outside of the cartridge and is fixed to the wall of the cartridge. The object underlying the present invention is to provide a reliable mechanism for closing/opening a toner falling aperture which reliably prevents toner from scattering and can readily be opened when installed in an image forming apparatus. The mechanism for closing/opening a toner falling aperture according to the invention is characterized in that the rotatable means comprise rotary toner delivery means adapted to deliver toner, housed inside of the toner cartridge main body, to the toner falling aperture and adapted to take up the elastic sealing member when driven by an external driving source. According to a further development of the mechanism according to the invention, the elastic sealing member is attached to the inner surface of the bottom of the toner cartridge main body. In a specific embodiment of the mechanism according to the invention, the elastic sealing member is a tape-like member. According to a further development of the mechanism according to the invention, it is provided that, in the closing position, the elastic sealing member is attached to the inner surface of the bottom and has a Z-shaped bent configuration adapted to be rolled off from the bottom and to be wound up on the rotatable means. In one specific embodiment of the invention, the rotary toner delivery means comprise a screw conveyor. In another specific embodiment of the invention, the rotary toner delivery means comprise rotary plate-like stirring blades. According to the arrangement above-mentioned, a toner cartridge which has not been used yet, is mounted on the main body of an image forming apparatus, and the taking-off means is then driven by an external drive source, so that the sealing member is wound on the taking-off means, causing the sealing member to be stripped off from the bottom of the toner cartridge main body. This causes the toner falling aperture to be opened. The sealing member to which toner is sticked, is taken up by the taking-off means and held inside of the toner cartridge main body. This prevents toner from scattering outside of the toner cartridge when the toner cartridge is replaced. The taking-off means may comprise rotary toner delivery means for delivering toner housed inside of the toner cartridge main body, toward the toner falling aperture. The rotary toner delivery means may comprise a screw conveyor. Preferably, the sealing member is a tape-like member. In such an arrangement, even though the sealing member is wound on a part of the rotary toner delivery means, no adverse effect is substantially exerted to the performance of- the toner delivery means. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a schematic section view of a toner cartridge including a mechanism for opening/closing a toner falling aperture according to an embodiment of the present invention, the toner cartridge being not under use; Figure 2 is an exploded perspective view of portions of the toner cartridge shown in Figure 1; Figure 3 is a schematic view of the inside arrangement of a copying apparatus; Figure 4 is a schematic section view of the toner cartridge with a sealing member thereof taken up; and Figure 5 is a schematic section view of a toner cartridge to which applied is a mechanism for opening/closing a toner falling aperture according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following will discuss in detail embodiments of the present invention with reference to the attached drawings. First Embodiment Figs. 1 to 4 show a first embodiment of the present invention. Referring to Fig. 3, a copying apparatus has, inside of the main body 1 thereof, (i) an optical system 3 where a document placed on a document placing plate 2 is illuminated and scanned, and light reflected from the document is guided to a photoreceptor drum 42, (ii) an image forming unit 4 where an electrostatic latent image formed on the photoreceptor drum 42 is converted into a toner image by a developing device 41, and the toner image is then transferred onto paper, and (iii) a paper delivery unit 5 where paper is pulled out from a paper feeding tray 61 in a paper housing portion 6 by a paper feeding roller 51 having a semicircular section, and the paper is passed through the image forming unit 4 and then discharged to a discharge tray 56 inside of the main body of the copying apparatus. With reference to Fig. 1, removably mounted on the main body 1 of the copying apparatus is a toner cartridge TC for supplying toner to the developing device 41. A mechanism for opening/closing a toner falling aperture according to an embodiment of the present invention, is characterized in that a sealing member S which closes a toner falling aperture TC2 in the toner cartridge TC, is adapted to be taken up by a screw conveyor SC, serving as rotary delivery means, disposed inside of the toner cartridge TC, as shown in Fig. 4. Referring to Fig. 3, the copying apparatus main body 1 has a lower unit 7 partitioned by a lower casing 71, and an upper unit 8 partitioned by an upper casing 81 supported in a manner rotatable around a predetermined axis of rotation m at the lower end thereof, the upper unit 8 being relatively rotatable with respect to the lower unit 7. The copying apparatus main body 1 is of a so-called clamshell type in which the upper unit 8 is rotatably opened/closed with respect to the lower unit 7. The optical system 3 is arranged such that a document is illuminated by a fluorescent lamp 39 having a reflector plate 38 secured to a first moving frame 3A, and light reflected from the document is guided to the photoreceptor drum 42 after successively passing through a first mirror 31 secured to the first moving frame 3A, second and third mirrors 32, 33 secured to a second moving frame 3B, a lens 37, fourth and fifth mirrors 34, 35 secured to a third moving frame 3C, and a sixth mirror 36. In the image forming unit 4, there are successively disposed, around the photoreceptor drum 42, a corona discharger 43, the developing device 41, a transferring corona discharger 44 and a cleaning device 45 in this order. The image forming unit 4 is arranged such that a document image is formed to form an electrostatic latent image on the outer peripheral surface of the photoreceptor drum 42 uniformly electrically charged by the corona discharger 43, the electrostatic latent image is converted into a toner image by the developing device 41, the toner image is transferred to paper by the transferring corona discharger 44, and residual toner is collected by the cleaning device 45. The paper delivery unit 5 comprises: the paper feeding roller 51 adapted to pull out paper, one by one, from the paper feeding tray 61; a delivery roller 52 for delivering paper from a manual paper feeding part 60 or the paper feeding tray 61; resist means 53 with which the tip of paper delivered by the delivery roller 52 comes in contact, causing the paper to temporarily wait, the resist means 53 being formed by driving roller means 53a and driven roller means 53b; a fixing unit 54 for fixing a toner image transferred onto paper; and a pair of discharging roller means 55. Referring to Figs. 1 and 2, the toner cartridge TC comprises: a container-like toner cartridge main body T1; an aperture TC2 which is formed in the bottom TC1 of the toner cartridge main body T1 and through which toner is adapted to fall toward the developing device 41; a pair of screw conveyors SC disposed inside of the toner cartridge main body T1 in the longitudinal direction thereof; and the tape-like narrow sealing member S having one end S1 which closes the aperture TC2 at the inside of the toner cartridge main body T1 while the toner cartridge TC is not under use. The other end S2 of the sealing member S is secured to a helical blade SC1 of one screw conveyor SC. The sealing member S is sticked to the edge of the aperture TC2 by heat fusion or the like. The screw conveyors SC are adapted to be rotated in opposite directions (See arrows shown by chain lines in Fig. 1) to feed toner in opposite direcitons (See white arrows in Fig. 2). This causes toner to be circulated while passing on the aperture TC2 inside of the toner cartridge main body T1. The toner cartridge main body T1 is provided at the pulling-side end thereof with a channel-like movable grip T2. The grip T2 can be housed in a concave portion T3 formed at the pulling-side end such that the grip T2 does not project from the pulling-side end when the grip T2 is not under use. According to the embodiment above-mentioned, when the toner cartridge TC which has not been used yet, is mounted on the copying apparatus main body 1 and the screw conveyors SC are rotatingly driven, the sealing member S is taken up by one of the screw conveyors SC under rotation. This causes the sealing member S to be torn off from the aperture TC2, thus opening the aperture TC2 (See Fig. 4). The sealing member S to which toner is sticked, is taken up inside of the toner cartridge main body T1. This prevents toner from scattering outside of the toner cartridge TC when the toner cartridge TC is replaced. Accordingly, no toner scatters inside and outside of the copying apparatus main body 1 when the toner cartridge TC is replaced. The sealing member S is in the form of a narrow tape. Accordingly, even though the sealing member S is wound on a portion of the screw conveyor SC, no adverse effect is substantially exerted on the delivery performance of the screw conveyor SC. Second Embodiment Instead of the screw conveyors used in the embodiment in Fig. 1, there may be used a toner stirring and delivery mechanism DM as shown in Fig. 5. In the toner stirring and delivery mechanism DM, a plurality of rotary plate-like stirring blades DM1 and the like are disposed in the toner delivery direction so that toner is stirred and delivered. In such an arrangement, too, a sealing member S can be taken up by one of the stirring blades DM1, and similar effects to those produced in the embodiment in Fig. 1, can be produced.

Claims: A mechanism for closing/opening a toner falling aperture (TC2) formed in the bottom (TC1) of the main body (T1) of a toner cartridge (TC) in which toner is housed, wherein an elastic sealing member (S) is removably attached to the bottom (TC1) of the toner cartridge main body (T1) for closing the toner falling aperture (TC2) and wherein rotatable means (SC) are disposed inside of the toner cartridge main body (T1) to which the elastic sealing member (S) is secured and which are adapted to take off the elastic sealing member (S) when rotated, characterized in that the rotatable means (SC) comprise rotary toner delivery means adapted to deliver toner, housed inside of the toner cartridge main body (T1), to the toner falling aperture (TC2) and adapted to take up the elastic sealing member (S) when driven by an external driving source. The mechanism according to claim 1, characterized in that the elastic sealing member (S) is attached to the inner surface of the bottom (TC1) of the toner cartridge main body (T1). The mechanism according to claim 1 or 2, characterized in that the elastic sealing member (S) is a tape-like member. The mechanism according to any of claims 1 to 3, characterized in that , in the closing position, the elastic sealing member (S) is attached to the inner surface of the bottom (TC1) and has a Z-shaped bent configuration adapted to be rolled off from the bottom (TC1) and to be wound up on the rotatable means (SC). The mechanism according to any of claims 1 to 4, characterized in that the rotary toner delivery means (SC) comprise a screw conveyor. The mechanism according to any of claims 1 to 4, characterized in that the rotary toner delivery means (DM) comprise rotary plate-like stirring blades (DM1).

Inventors: FUJISAWA SHUJI, KOMAKI SUSUMU, FUJISAWA, SHUJI, KOMAKI, SUSUMU, FUJISAWA, SHUJI, C/O MITA INDUSTRIAL CO.,LTD., KOMAKI, SUSUMU, C/O MITA INDUSTRIAL CO.,LTD.
Applicants: KYOCERA MITA CORP, KYOCERA MITA CORPORATION
Application year: 1993
Main classification: G03G15
IPC codes: G03G15