Waste toner collecting container provided with corona charger

Abstract: A waste toner collection container equipped with a corona charger for use in an electrophotographic arrange­ ment, which includes a waste toner collecting box (11a) for accommodating residual toner scraped off a photosensitive surface of a photosensitive member (10) after transfer, and a corona charger adapted to charge the photosensitive surface of the photosensitive member (10) after charge erasing of the photosensitive surface, with the corona charger being provided on the waste toner collecting box (11a).

Description: The present invention generally relates to an electrophotographic arrangement of an electrostatic transfer type having a detachably mounted waste toner collecting container provided with a corona charging means. Generally, in a laser printer or the like which is an electrophotographic apparatus of an electrostatic transfer type, etc., it is so arranged that, after uniformly charging the photosensitive surface of a photosensitive member in a drum shape (referred to as a photoreceptor drum hereinafter), laser light from a semi-conductor laser unit or the like is irradiated onto the photosensitive surface so as to form an electrostatic latent image on said photosensitive surface, and toner for a developing material is caused to adhere onto the latent image by a developing device provided in the vicinity of the photoreceptor drum so as to form a visible toner image, which is subsequently transferred onto a copy paper sheet fed to a transfer station, while residual toner adhering onto the surface of the photoreceptor drum is scraped off by a cleaning blade or the like so as to be accommodated into the waste toner collecting container. Incidentally, the photoreceptor drum, corona charger and developing material as referred to above are expendables, and required to be replaced periodically. Similarly, with respect to the waste toner collecting container also, it is necessary to periodically exchange or to take out the waste toner therefrom for maintaining the container in a condition to receive waste toner at all times. However, in order to exchange the photoreceptor drum, corona charger, developing material, and waste toner collecting container, etc., individually, appreciably much time and labor are required therefor. Accordingly, there has conventionally been proposed an arrangement capable of exchanging the corona charger also upon replacement of a photoreceptor drum or another arrangement in which the items required to be exchanged such as the photoreceptor drum, corona charger, developing material, and waste toner collecting container, etc. are incorporated into one cartridge so that they can be replaced simultaneously. In the conventional construction as described above, however, before it becomes necessary to replace the photoreceptor drum, developing material or the like whose life has been prolonged recently, toner scattering in air tends to adhere to a charger line of the corona charger, thus undesirably giving rise to irregularity or variation in the charger output with respect to the photoreceptor. Therefore, it has been required to periodically clean the charger line by an exclusive cleaning item, with such an inconvenience that troubles, for example, breakage or deformation of the charger line, etc. tend to take place during the cleaning. From Patent Abstract of Japan Vol. 10 Number 53 (P-433) [2110], 4th March 1986; & JP-A-60 198 574 (KONIOSHIROKU SHASHIN KOGYO) 08-10-85, there is known an electrophotographic arrangement in which the corona charger means is separated from the casing of the cleaning device for cleaning the photoreceptor drum from residual toner particles. In EP-A-0 228 062 a photoreceptor cartridge unit is disclosed having a cartridge frame on which the photoreceptor drum, the corona charger means and the cleaning means are integrally mounted. The complete unit may be removed from and inserted into an electrophotographic arrangement. Thus, besides the cleaning means and the corona charger means also the photoreceptor drum must be exchanged upon the execution of periodically maintenance operations. Accordingly, an essential object of the present invention is to provide an electrophotographic arrangement in which the waste toner collecting container as well as the corona charger means can be easily detached from the housing of the electrophotographic arrangement. In accomplishing this object, according to the present invention, there is provided an electrophotographic arrangement of an electrostatic transfer type, comprising a housing, a photoreceptor member having a photosensitive surface, a waste toner collecting container, and a corona charging means connected to the waste toner collecting container and comprising a charger case and a corona charger wire disposed within the charger case. The charging means is also adapted to charge the photosensitive surface of the photoreceptor member after charge erasing of the photosensitive surface. A cleaning blade is also provided, held at the waste toner collecting box to be in contact, at its forward edge, with the photosensitive surface of the photoreceptor member. In the electrophotographic arrangement according to the invention, the waste toner collecting container is provided with a waste toner collecting box generally extending over the lateral width of the photoreceptor drum and being open at its side confronting the photosensitive surface of the photoreceptor drum. The corona charger means is connected to the waste toner collecting box of the waste toner collecting container and is open at its side confronting the photosensitive surface of the photoreceptor drum. The waste toner collecting container is mounted by means of fitting portions extending outwardly from opposite side walls of the waste toner collecting box and received through support members provided at the housing opposite to the fitting portions. The support members is capable to receive and release the fitting portions only when the waste toner collecting box is oriented generally vertically with the open side of the waste toner collecting box being oriented in an upward direction. When the fitting portions are received from the support members, the waste toner collecting box can be rotated so as to bring the open sides of the waste toner collecting box and of the corona charger means in a confronting state with respect to the photosensitive surface of the photoreceptor member. In addition, a waste toner inducing vane is rotatably arranged within the waste toner collecting box in the vicinity of the cleaning blade, for transporting waste toner scraped off the photosensitive surface of the photoreceptor member into the waste toner collecting box. By the arrangement of the present invention as described above, the replacement of the waste toner collecting container becomes necessary before irregularity or variation is undesirably produced in the charger output with respect to the photosensitive surface due to adhesion of toner scattering in air onto the charger line of the corona charger, and thus, the corona charger can be replaced together with the waste toner collecting box. Accordingly, it becomes unnecessary to periodically clean the charger line by an exclusive cleaning item, and consequently, the possibility of giving rise to such troubles as breakage or deformation of the charger line during cleaning, etc. may be advantageously eliminated. The waste toner collecting container of the electrophotographic arrangement according to the invention is simple in handling and construction and stable in functioning at high relyability. In the following a preferred embodiment of the invention will be described in conjunction with the drawings, in which: Fig. 1(a) is a side sectional view of a waste toner collecting container provided with a corona charger according to one preferred embodiment of the present invention, Fig. 1(b) is a fragmentary rear side view of the waste toner collecting container of Fig. 1(a), Fig. 1(c) is a fragmentary perspective view at the rear side portion of the waste toner collecting container of Fig. 1(a) particularly showing, on an enlarged scale, fitting portions thereof with respect to an electrophotographic arrangement, and Fig. 2 is a schematic side sectional views of a laser printed to which the waste toner collecting container according to the present invention may be applied. Before the description of the present invention proceeds, it is to be noted that like parts are designated by like reference numerals throughout the accompanying drawings. Referring now to the drawings, there is shown in Fig. 2, a laser printer to which a waste toner collecting container according to the present invention may be applied. The laser printer generally includes a housing 26 with a cross section in approximately a triangular configuration, a manual paper feeding section 21 having a feeding roller 20 and provided at an upper portion of the housing 26, a face-down tray 19 provided under the manual paper feeding section 21 along an inclined face of the housing 26 for accommodating paper sheets discharged after printing, with a face-down paper receiving port 19a being provided in a lower side wall of the face-down tray 19, and a paper feeding cassette 1 for accommodating paper sheets, mounted on the back wall of the face-down tray 19, at an inclination angle approximately in the same degree as that for the face-down tray 19, with an introducing roller 5 and a feeding roller 6 being provided at the upper portion of the paper feeding cassette 1 as illustrated. A paper transport passage 25 for connecting the paper feeding side of the cassette 1 with the face-down paper receiving port 19a is formed through the back side of the paper feeding cassette 1. At the lower end side of the paper feeding cassette 1, there is provided a guide wall member 2 which forms one part at one side of the paper transport passage 25, while at the lower end portion of said guide wall member 2, a roller 4 constituting one of a set of discharge rollers is provided. Moreover, on a bottom wall of the paper feeding cassette 1, a mirror 3 is mounted, and beside the paper feeding cassette 1 adjacent to its bottom wall, a semi-conductor laser unit 12 is provided as shown by two-dotted chain lines. Thus, laser light emitted from the semi-conductor laser unit 12 is arranged to be reflected by the mirror 3 so as to be projected onto the photosensitive surface 10a of the photoreceptor drum 10. Along the paper transport passage 25 from the paper feeding cassette 1 to the face-down tray 19, sets of transport rollers 7, 8, and 9 are provided for transporting the paper sheet fed from the rollers 6 and 20 towards the photoreceptor drum 10. Meanwhile, around the photoreceptor drum 10, waste toner collecting container 11 equipped with a corona charger for charging the photosensitive surface 10a of the photoreceptor drum 10, a developing device 13 for developing an electrostatic latent image formed on the photosensitive surface 10a of the photoreceptor drum 10 into a visible toner image, and a transfer charger 14 for transferring the toner image thus developed onto a paper sheet are sequentially disposed as shown. In the above construction, the waste toner collecting container 11 equipped with the corona charger, and directly related to the present invention generally includes as also shown in Fig. 1(a), a waste toner collecting box 11a extending over a length approximately the same as a lateral width of the photoreceptor drum 10 and having a generally U-shaped cross section so as to be open at its side 11j confronting the photosensitive surface 10a of the photoreceptor drum 10, a charger case 11b in a cubic box-like configuration, attached adjacent to the open side 11j of the waste toner collecting box 11a and similarly open at its side facing the photosensitive surface of the photoreceptor drum 10, and a corona charger line 11g disposed within said charger case 11b. It should be noted here that the charger case 11b referred to above may be integrally formed with the waste toner collecting box 11a, or separately attached to said waste toner collecting box 11a as in the above embodiment. Within the waste toner collecting box 11a, there is provided a cleaning blade 11f held between a partition wall 11r and a holding member 11d fixed to an upper wall of said collecting box 11a so as to be in contact, at its forward edge, with the surface 10a of the photoreceptor drum 10, while a waste toner inducing vane 11e for transporting the waste toner is rotatably provided in the vicinity of the cleaning blade 11f for introducing the waste toner scraped off the photosensitive surface 10a by the blade 11f into said collecting box 11a. As shown in Fig. 1(b) also, in positions close to rear lower corners of the collecting box 11a, fitting portions 11c each having generally a rectangular cross section are provided to extend outwardly from opposite side walls of said collecting box 11a so as to detachably mount the waste toner collecting container 11 equipped with the corona charger in the housing 26 by fitting said fitting portions 11c with support members 15 provided in corresponding positions on the side walls within said housing 26. Each of the support members 15 laterally extending from the side walls of the housing 26 has a circular cross section open at an upper portion, and after inserting the respective fitting portions 11c of the collecting box 11a into the support members 15 vertically in a longitudinal direction through the upper opening of said support members 15, the collecting box 11a is rotated to bring the fitting portions 11c thereof into the state as shown in Fig. 1(c) for fixing of said collecting box 11a in the housing 26. Referring back to Fig. 2, within the housing 26 of the laser printer, in the feeding direction of the paper sheets with respect to the photoreceptor drum 10, there are disposed a set of heat rollers 16 functioning as a fixing device for heating and fixing the toner image transferred onto the paper sheet from the photoreceptor drum 10, a roller 17 which constitutes a set of discharge rollers together with the roller 4 of the paper feeding cassette 1 in the state where said cassette 1 is mounted, a transport passage changing member 23 which forms part of a paper transport passage 25 by being caused to confront the guide wall member 2 of the cassette 1 through a predetermined interval and another discharge roller 18 disposed at the face-down paper receiving port 19a for the face-down tray 19. By the above arrangement, during the printing function, as the photosensitive surface 10a of the photoreceptor drum 10 faces the charger case 11b of the waste toner collecting container 11 while the photoreceptor drum 10 rotates, corona discharge is produced through application of high voltage to the charger line 11g, thereby to charge the surface 10a of the photoreceptor drum 10. Subsequently, the laser light emitted from the semi-conductor laser unit 12 as indicated by the dotted chain line in Fig. 2 is projected onto the surface 10a of the photoreceptor drum 10 through the mirror 3, and only the portion of the surface 10a thus exposed to the laser light is erased so as to form the electrostatic latent image, which is developed into the visible image through adhesion of toner thereto as it confronts the developing unit 13. On the other hand, the paper sheet is fed into the transport passage 25 from the manual paper feeding section 21 through the paper feeding roller 20 or from the paper feeding cassette 1 through the rollers 5 and 6, and thereafter, transported towards the photoreceptor drum 10 by the transport rollers 7, 8 and 9. Thus, the toner image formed on the photoreceptor drum 10 is transferred onto the paper sheet by the transfer charger 14, and the toner image thus transferred is heated and fixed onto the paper sheet by the heat roller 16. Subsequently, the paper sheet is discharged by the rollers 4 and 17 and the transport passage changing member 23, into the discharge port 22 or into the face-down tray 19 from the face-down paper receiving port 19a via the discharge roller 18. At the photoreceptor drum 10, the residual toner still adhering to the photosensitive surface 10a after transfer of the toner image is scraped off by the cleaning blade 11f, and subsequently, accommodated into the waste toner collecting box 11a as the inducing vane 11e rotates. When the interior of the collecting box 11a has been filled up with the waste toner, the waste toner collecting box 11a provided with the corona charger is rotated about the support members 15 in a direction indicated by an arrow A in Fig. 1(a) to disengage the fitting portions 11c of the collecting box 11a from the support members 15 for replacement of the collecting box 11a. In this case, the charger case 11b attached to the collecting box 11a is also to be exchanged, and the possibility of irregularity or variation in the charger output with respect to the photoreceptor drum 10 due to adhesion of scattering toner in air to the charger line 11g may be removed. Therefore, it becomes unnecessary to periodically clean the charger line by an exclusive cleaning item, and consequently, the possibility of giving rise to such troubles as breakage or deformation of the charge line during cleaning, etc. may be advantageously eliminated. As is clear from the foregoing description, the waste toner collecting container provided with the corona charger according to the present invention is so arranged that the corona charger for charging the photosensitive member after charge erasing is provided on the waste toner collecting box for accommodating toner scraped off the photosensitive surface after transfer. By the above arrangement of the present invention, not only the necessity for cleaning the charger line of the corona charger is eliminated, but the possibility of such troubles as breakage or deformation, etc. of the charger line during cleaning is also removed.

Claims: Electrophotographic arrangement of an electrostatic transfer type comprising a housing (26), a photoreceptor member (10) having a photosensitive surface (10a), a waste toner collecting container (11) for accommodating residual toner taken off said photosensitive surface (10a) of said photoreceptor member (10), said waste toner collecting container (11) having a waste toner collecting box (11a) extending over a length generally the same as a lateral width of the photoreceptor member (10), said waste toner collecting box (11a) being open at its side (11j) confronting said photosensitive surface (10a) of said photoreceptor member (10), a corona charging means (11b,11g) provided on said waste toner collecting box (11a) and being adapted to charge the photosensitive surface (11) of the photoreceptor member (10) after charge erasing of the photosensitive surface (11) and being open at its side confronting said photosensitive surface (10a) of said photoreceptor member (10), said corona charging means (11b,11g) comprising a charger case (11b) and a corona charger line (11g) disposed within said charger case (11b), a cleaning blade (11f) held at said waste toner collecting box (11a) to be in contact, at its forward edge, with said photosensitive surface (10a) of said photoreceptor member (10) and fitting portions (11c) provided at said waste toner collecting box (11a) and support members (15) provided at said housing (26) opposite to said fitting portions (11c), for mounting said waste toner collecting box (11a) on said housing (26), characterized in that said fitting portions (11c) extend outwardly from opposite side walls of said waste toner collecting box (11a) and said support members (15) are provided for detachably mounting said waste toner collecting box (11a) on said housing (26), that said support members (15) are arranged to receive and release said fitting portions (11c) only upon generally vertically orienting said waste toner collecting box (11a), when said fitting portions (11c) are received through said support members (15), said waste toner collecting box (11a) being rotatable so that the open sides of said waste toner collecting box (11a) and of said corona charging means (11b,11g) confront said photosensitive surface (10a) of said photoreceptor member (10) or the open side of the waste toner collecting box (11) is oriented in an upward direction, and that a waste toner inducing vane (11e) is rotatably arranged within said waste toner collecting box (11a) in the vicinity of said cleaning blade (11f), for transporting waste toner scraped off said photosensitive surface (10a) of said photoreceptor member (10) into said waste toner collecting box (11a). Electrophotographic arrangement according to claim 1, characterized in that said charger case (11b) is integrally formed with said waste toner collecting box (11a). Electrophotographic arrangement according to claim 1, characterized in that said charger case (11b) is separately mounted on said waste toner collecting box (11a). Electrophotographic arrangement according to claim 1 and 2 or 1 and 3, characterized in that said charger case (11b) being formed, in part, by a partition wall (11r) and said waste toner collecting box having a holding member (11d) affixed to an upper wall of said waste toner collecting box (11a), said partition wall (11r) and said holding member (11d) mounting said cleaning blade (11f) in position. Electrophotographic arrangement according to claim 4, characterized in that said one-piece waste toner collecting container (11) comprising said waste toner collecting box (11a) and said charger case (11b) is generally free of interior structure except for said waste toner inducing vane (11e), said holding member (11d), said cleaning blade (11f), said partition wall (11r) and said corona charger line (11g).

Inventors: HONDA IWAKUZU, YUI YUHI, HONDA, IWAKUZU, YUI, YUHI
Applicants: SHARP KK, SHARP KABUSHIKI KAISHA
Application year: 1989
Main classification: G03G21
IPC codes: G03G15, G03G21