With reference to the drawings, description will be made of preferred embodiments of the present invention. An image forming device 100 in
The image recording unit 3 includes a process portion and a fuser 11 arranged at a downstream side of the process portion. The process portion includes a photoconductive drum 5. A corona charger 6, an exposing unit 7 having a Light Emitting Diode (LED), a developing device 8, a transfer roller (a transfer device) 9, and a transfer residual toner cleaning device 10 are arranged in this order around the photoconductive drum 5. Excluding the exposing unit 7 and the transfer roller 9, the process portion is provided as a process unit including a drum unit 50 and a developing device unit 80. The drum unit 50 collectively includes the photoconductive drum 5, the charger 6, and the transfer residual toner cleaning device 10. The developing device unit 80 collectively includes a developing device housing 81, agitating and transporting screws 82, 83, a supply paddle 84, and a developing roller 85. The drum unit 50 and the developing device unit 80 can be removably inserted into the device main body 1 from a front surface side of the device main body 1 separately or under a state in which the units 50 and 80 are combined by some joining member. The entire process portion excluding the exposing unit 7 and the transfer roller 9 may be collectively provided as a unitary process unit. The process unit can be exchanged as a consumable unit with a new unit if required. The front surface side of the device main body 1 refers to a front side in
The developing device unit 80 is a developing device which uses a developer including two components. The developing device housing 81 is preferably formed by resin molding and is also used as a developer container. Toner and carrier are contained in the developing device housing 81. The two mutually parallel agitating and transporting screws 82 and 83 agitate and transport the toner. The supply paddle 84 supplies the biased developing roller 85 with the developer. A magnetic sensor 86 is provided on an outer surface of the developing device housing 81. The magnetic sensor 86 detects a toner concentration (mixture ratio of the toner and the carrier) inside the developing device housing 81. A toner container 12 and a toner supplying hopper 13 defining a toner containing portion are arranged at a position that is spaced apart from the developing device unit 80. When the magnetic sensor 86 detects that the toner concentration inside the developing device housing 81 is decreased, toner is supplied from the toner hopper 13 into the developing device housing 81 via a screw conveyor (a pipe screw) 14. An agitator 121 and a toner feeding screw 122 that supplies the toner hopper 13 with the toner are provided in the toner container 12.
The toner container 12 is integrated with a waste toner container 15 as the toner containing portion. The toner container 12, as described below, is provided as a toner cartridge 16 that can be removably inserted into the device main body 1. A screw conveyor 17 is connected to the waste toner container 15. The waste toner removed and collected by the cleaning device 10 is sequentially transported and transferred to the screw conveyor 17. A toner transporting mechanism is established when the developing device unit (process unit) 80 including the developing device 8, the drum unit (process unit) 50, the toner containing portions 12, 13, and 15 are connected. The toner transporting mechanism will be described in detail below.
A switching gate 41, a discharge roller pair 42, and a discharge tray 43 are arranged at a downstream side of the fuser 11. The switching gate 41, the discharge roller pair 42, and the discharge tray 43 define the discharge unit 4. A resist roller pair 18 is arranged near an upstream side of the process portion. The recording papers (papers) are separated and fed one sheet at a time from the paper feed cassette 201 by the paper separating and feeding roller 202 and the separating pad 203. The recording paper is resisted by the resist roller pair 18 and introduced into a nip portion between the photoconductive drum 5 and the transfer roller 9. The photoconductive drum 5 rotates in a direction indicated by an arrow in
The electrostatic latent image is sequentially developed by the biased developing device 8, and a toner image reaches the nip portion between the photoconductive drum 5 and the transfer roller 9. During this developing process, on the portion where the electric potential has been changed by light irradiation, the toner is adhered to the photoconductive drum 5 to form a black portion due to a potential difference between the developing device 8 and the electrostatic latent image. The toner is not adhered to the other portion, where a white portion is formed. As a whole, a black and white toner image based on the image information is formed. The resist roller pair 18 is resist-controlled, and then, rotated such that the recording paper is introduced into the nip portion in synchronism with the toner image on the surface of the photoconductive drum 5.
The transfer roller 9 is biased and paired with the photoconductive drum 5. The transfer roller 9 nips and transports the recording paper while being rotated in a direction indicated by an arrow in
The image forming device 100 illustrated in the drawings includes a duplex printing function. A reverse feeding path P1 is provided such that the reverse feeding path P1 circulates from a position where the switching gate 41 is arranged at an upstream side of the resist roller pair 18 in the main feeding path P, and joins the main feeding path P. The discharge roller pair 42 can rotate in both directions. Transportation roller pairs 19 and 20 are provided in the reverse feeding path P1. When performing a duplex printing, after one side of the recording paper is printed as described above, the recording paper is transported along the main feeding path P, and a trailing edge of the recording paper reaches the discharge roller pair 42. Then, the discharge roller pair 42 stops once and nips the trailing edge of the recording paper. Next, the discharge roller pair 42 rotates reversely, and the recording paper, with the trailing edge thereof ahead, is transported through the reverse feeding path P1 by the transportation roller pairs 19 and 20. The recording paper then joins the main feeding path P and reaches the resist roller pair 18. The recording paper is resisted by the resist roller pair 18, and again introduced into the nip portion between the photoconductive drum 5 and the transfer roller 9, where a reverse side of the recording paper is printed. After both sides of the recording paper are printed, the recording paper is transported along the main feeding path P and discharged onto the discharge tray 43 as described above.
The image forming device 100 illustrated in the drawings further includes a manual paper feeding function. A manual paper feeding tray 21, which can be opened and closed vertically, is provided on a side portion of the device main body 1. When not using the manual paper feeding tray 21, the manual paper feeding tray 21 is closed as illustrated by double-dashed lines in
When performing an image printing using the manual paper feeding tray 21, the gripper 211 is operated to open the manual paper feeding tray 21. The recording papers are placed on the manual paper feeding tray 21. After a start operation is performed, the manual paper separating and feeding roller 212 is operated. The recording papers on the manual paper feeding tray 21 are separated and fed one sheet at a time by the manual paper separating and feeding roller 212 and the separating pad 213. The recording paper is transported through the manual feeding path P2, and joins the main feeding path P. Then, the recording paper is resisted by the resist roller pair 18 and introduced into the nip portion between the photoconductive drum 5 and the transfer roller 9, where the printing is performed. When performing the duplex printing on a manually fed recording paper, the recording paper is transported by the reversely rotating discharge roller pair 42 through the reverse feeding path P1. Then, as described above, the reverse side of the recording paper is printed. After the printing is completed, the recording paper is discharged onto the discharge tray 43 by the discharge roller pair 42.
Next, a description will be made of the toner transporting mechanism. In
The toner cartridge 16, in which the toner container 12 and the waste toner container 15 are integrally provided, can also be removably inserted into the device main body 1. The toner cartridge 16 can be inserted from the front side of the device main body 1 (the lower side in
The first toner receiving/supplying portion T1 is connected as described below. When the developing device unit 80 along with the drum unit 50 is inserted along the direction “X” indicated by the outlined arrow into a prescribed position in the device main body 1, a front end portion 8131 of the shutter 813 makes contact with an action portion 1431. The action portion 1431 extends downwards from the shutter 143 of the screw conveyor 14. When the developing device unit 80 is further inserted, due to a magnitude correlation between the spring force of the helical compression spring 142 and the spring force of the helical compression spring 812, the helical compression spring 812 is compressed against its own elastic force. Then, the shutter 813 moves backward in a direction opposite the direction “X” with respect to the developing device housing 81. As a result, an open portion 8132 of the shutter 813 is moved to the toner receiving port 811, and thus, the toner receiving port 811 is opened. Under the above-described state, a rear end of the shutter 813 makes contact with the developing device housing 81, and the shutter 813 is stopped from moving further. When the developing device unit 80 is inserted further, the helical compression spring 142 is compressed against its own elastic force, and the shutter 143 moves backward. Accordingly, the toner supplying port 141 of the screw conveyor 14, the open portion 8132 of the shutter 813, and the toner receiving port 811 of the developing device housing 81 are aligned. Thus, the first toner receiving/supplying portion T1 is established. When the developing device unit 80 is removed in the direction opposite to the direction “X”, the toner supplying port 141 and the toner receiving port 811 are respectively closed by the shutters 143 and 813 with each biasing elastic force of the helical compression springs 142 and 812.
In a connecting and disconnecting operation of the toner receiving/supplying portion T1 described above, along with the movement of the shutters 143 and 813, it is unavoidable that some amount of the adhered toner leaks to the outside. Since the leaked toner accumulates around the toner receiving/supplying portion T1, the accumulated toner is stirred up and scattered by oscillations and impacts occurred upon the above-described connecting and disconnecting operation. At the first toner receiving/supplying portion T1, a porous member (a trapping member) 814 is attached to a surface of the developing device housing 81, in the vicinity of the toner receiving port 811. The porous member 814 is preferably composed of urethane foam, etc. The porous member 814 includes a plurality of micro cells therein. Therefore, toner particles that have been leaked and scattered upon the connecting and disconnecting operations can be trapped and fixed inside the micro cells. Thus, the toner stirred up by the oscillations and impacts can be reduced.
As illustrated in
The toner hopper 13 temporarily stores the toner supplied from the toner container 12. When the magnetic sensor 86 of the developing device 8 sends a signal of toner shortage, the screw conveyor 14 connected to the toner hopper 13 is operated. The toner is supplied from the first toner receiving/supplying portion T1 into the developing device housing 81. In order to constantly store a prescribed amount of toner in the toner hopper 13, operation control of the feeding screw 122 is performed based on a detection signal from a sensor (not illustrated) provided in the toner hopper 13. The prescribed amount of toner stored in the toner hopper 13 can be set to an amount sufficient to continue a printing operation, for example, until the toner cartridge 16 is changed to a new one when there is no toner in the toner container 12. In a preferred embodiment of the present invention, since an amount of toner leakage at the second toner receiving/supplying portion T2 is small due to a connection structure of the second toner receiving/supplying portion T2, the toner trapping member described above is not particularly required to be attached to the toner receiving/supplying portion T2. However, if the toner leaks due to features of the connection structure, the toner trapping member described above may also be attached in the vicinity of a toner leaking portion.
From a state illustrated in
As described above, by establishing the third toner receiving/supplying portion T3, the transfer residual toner removed and collected by the cleaning device 10 is sequentially accommodated from the waste toner transporting screw conveyor 17 into the waste toner container 15. When the toner cartridge 16 is removed in the direction opposite to the direction “X1”, the cam pieces 1531, 1532, and the cam member 1731 are released, and the waste toner receiving port 151 and the waste toner discharging port 171 are respectively closed by the shutters 153 and 173 with each urging elastic force of the helical compression springs 152 and 172.
In a connecting and disconnecting operation of the toner receiving/supplying portion T3, along with the movement of the shutters 153 and 173, it is unavoidable that some amount of the adhered toner leaks to the outside. Since the leaked toner accumulates around the toner receiving/supplying portion T3, the accumulated toner is stirred up and scattered by the oscillations and impacts occurred upon the connecting and disconnecting operations. At the third toner receiving/supplying portion T3, the waste toner particularly easily accumulates on an upper surface of the shutter 153. Accordingly, as illustrated by cross-hatching, the porous member (the trapping member) 154 composed of urethane foam, etc. is attached to an upper portion of the constantly exposed shutter 153. The porous member 154 includes a plurality of micro cells therein. The toner particles that are leaked upon the connecting and disconnecting operations can be trapped and fixed inside the micro cells. Thus, the toner stirred up by the oscillations and impacts can be reduced. Particularly, the third toner receiving/supplying portion T3 is arranged on a front surface side of the device main body 1, that is, on a side on which a user stands. Therefore, when inserting and removing the process units 50, 80, and/or the toner cartridge 16, since the units 50, 80, and the toner cartridge 16 are positioned close to the user, if the toner scatters from the above-described portion, the toner can stain hands and clothing of the user. However, since the leaked toner can be effectively trapped by the porous member 154, such concerns can be cleared.
In the preferred embodiments of the present invention, the developing device using a two-component developer has been described as an example. However, the present invention is not limited to the above-described case, and can be applied to a case in which the developing device using a one-component developer is used. Moreover, in a case in which a cleanerless system is used, the waste toner transporting mechanism is not provided. Further, an attaching portion of the porous member (trapping member) 814 and 154 are not limited to the above-described examples. The toner can be prevented from scattering by attaching the porous member to a portion adjacent to the toner receiving/supplying portion, and to a portion where the leaked toner can easily accumulate. Furthermore, the examples have been described in which the process units 50, 80, and the toner cartridge 16 are inserted from the front surface side of the device main body 1. However, the present invention can be applied to a case in which the units 50, 80, and the toner cartridge 16 are inserted from a right or left surface side, or a rear side.
While the present invention has been described with respect to preferred embodiments thereof, it will be apparent to those skilled in the art that the disclosed invention may be modified in numerous ways and may assume many embodiments other than those specifically set out and described above. Accordingly, the appended claims are intended to cover all modifications of the present invention that fall within the true spirit and scope of the present invention.
Number | Date | Country | Kind |
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2006-246741 | Sep 2006 | JP | national |