JP2007086297A - Toner replenishing apparatus and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner replenishing apparatus and an image forming apparatus stably carrying out ejection of toner from a toner container even when toner supplying to the toner container is not in time. <P>SOLUTION: The toner replenishing apparatus is provided with: an ejecting member storing chamber (49) with a toner ejecting part (44a) through which toner circulating in toner circulating chambers (47, 48) is passed, the ejecting member storing chamber (49) storing a toner ejecting member (56) ejecting the toner inside the ejecting member chamber (49); and bypass openings (46c and 46d) formed on a downstream side in the toner circulating direction of the toner ejecting part (44a) and having the toner in the toner circulating chambers (47, 48) on the downstream side of the toner ejecting part (44a) flow into the ejecting member storing chamber (49). <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a toner replenishing device that replenishes toner used for image formation, and an electrophotographic image forming apparatus such as a copying machine, a printer, and a fax machine equipped with the toner replenishing device, and more particularly to a so-called reserve tank. The present invention relates to the toner replenishing device and the image forming apparatus having a toner container.

  Conventional electrophotographic image forming apparatuses often use a user-replaceable toner cartridge in order to replenish toner used for development. In recent years, a reserve tank for storing toner is provided so that the image forming operation can be continued even when the toner in the toner cartridge becomes empty, and the image forming operation is continued using the toner in the reserve tank (toner container). An image forming apparatus that can replace a toner cartridge is devised.

The following conventional technique (J01) is known as a technique related to a toner replenishing device having the reserve tank.
(J01) Techniques described in Patent Document 1 (Japanese Patent Laid-Open No. 3-217879), Patent Document 2 (Japanese Patent Laid-Open No. 4-139473), and Patent Document 3 (Japanese Patent Laid-Open No. 4-141681) Describes an image forming apparatus in which toner is circulated and transported in a reserve tank that temporarily stores toner supplied from a toner cartridge and then discharged to replenish the developing device.

JP-A-3-217879 (FIGS. 6 to 9) Japanese Patent Laid-Open No. 4-139473 (FIGS. 3, 4, and 10) Japanese Patent Laid-Open No. 4-141681 (FIGS. 3, 4, and 9)

(Problems of conventional technology)
In the image forming apparatus of the prior art (J01), even if the toner cartridge becomes empty, the image forming operation can be continued using the toner in the reserve tank for a predetermined period or until a predetermined number of printed sheets. In such a conventional image forming apparatus, when a new toner cartridge is installed, image formation is temporarily interrupted, and the toner is supplied from the toner cartridge until the toner amount reaches a predetermined amount in the reserve tank. The amount of toner in the tank was often recovered.
However, in recent years, there has been a demand for improving the productivity by minimizing the stop time of the image forming operation, eliminating the interruption time after the replacement of the toner cartridge, and the image formation without interruption even when the toner cartridge is replaced. Configurations that continue to form are beginning to be adopted. In this case, after replacement of the toner cartridge, unless the toner more than the amount consumed by the continued image formation is supplied rapidly to the reserve tank, the toner cannot be supplied from the reserve tank to the developing device in time, and the developing device cannot There is a problem in that the toner density is lowered and defective image formation occurs.

  However, depending on the arrangement and arrangement of the constituent members of the image forming apparatus, it may be necessary to arrange the toner inlet of the reserve tank and the toner discharge portion apart from each other. In particular, in a large-capacity reserve tank employed in an image forming apparatus capable of high-speed printing, the distance between the toner inlet and the toner discharge portion tends to be wide. If image formation is continued even after the toner cartridge is emptied, the toner is sequentially transported to the toner discharge portion in a state where the toner is not replenished, so that the amount of toner on the downstream side of the toner inlet tends to be very small. Even if the toner cartridge is replaced in this state and toner is rapidly supplied from the toner cartridge to the reserve tank, it takes time until the toner is transported from the toner inlet to the toner discharge portion, and the toner density of the developing device is lowered. There is a problem that cannot be prevented sufficiently.

In view of the above circumstances, the present invention has the following description (O01) as a technical problem.
(O01) To stably discharge toner from the toner container even if the toner supply to the toner container is not in time.

(Invention)
Next, the present invention that has solved the above problems will be described. In order to facilitate the correspondence between the elements of the present invention and elements of specific examples (examples) of the embodiments described later, Add the code enclosed in parentheses. The reason why the present invention is described in correspondence with the reference numerals of the embodiments described later is to facilitate understanding of the present invention, and not to limit the scope of the present invention to the embodiments.

(First invention)
In order to solve the above technical problem, the toner replenishing device according to the first aspect of the invention is characterized by comprising the following structural requirements (A01) and (A02).
(A01) a first transfer chamber (47) that houses a first transfer member (51) that transfers toner flowing in from the toner inlet (RT2a) in a predetermined first transfer direction (Yb); and The second transport member (52) transported in the second transport direction (Yc) different from the first transport direction (Yb) is accommodated, and the first transport chamber (47) is provided upstream and downstream in the first transport direction (Yb). A second transfer chamber (48) communicating with the toner), a toner circulation chamber (47 + 48) in which toner is circulated and conveyed,
A discharge member storage chamber (49) having a toner discharge portion (44a) through which the toner circulating in the toner circulation chamber (47 + 48) passes, and discharging the toner in the discharge member storage chamber (49) The discharge member accommodating chamber (49) for accommodating the member (56);
A toner container (RT) having
(A02) The toner in the toner circulation chamber (47 + 48) formed downstream of the toner discharge portion (44a) in the toner circulation direction and downstream of the toner discharge portion (44a) flows into the discharge member storage chamber (49). Bypass ports (46c, 46c ', 46c ", 46d).

(Operation of the first invention)
In the toner replenishing device according to the first aspect of the present invention having the structural requirements (A01) and (A02), the toner flowing from the toner inflow port (RT2a) into the first transfer chamber (47) of the toner container (RT) is predetermined. The 1st conveyance member (51) conveyed in the 1st conveyance direction (Yb) is accommodated. The second transfer chamber (48) accommodates a second transfer member (52) for transferring the toner in a second transfer direction (Yc) different from the first transfer direction (Yb). A toner circulation chamber (47 + 48) having the first transfer chamber (47) and a second transfer chamber (48) communicating with the first transfer chamber (47) at the upstream and downstream portions in the first transfer direction (Yb). In the toner, the toner is circulated and conveyed. A toner discharge member (56) is stored in the discharge member storage chamber (49) having a toner discharge portion (44a) through which the toner circulating in the toner circulation chamber (47 + 48) passes. The toner discharge member (56) discharges the toner in the discharge member storage chamber (49). Bypass ports (46c, 46c ′, 46c ″, 46d) formed on the downstream side of the toner discharge portion (44a) in the toner circulation direction are located in the toner circulation chamber (47 + 48) on the downstream side of the toner discharge portion (44a). The toner is caused to flow into the discharge member storage chamber (49).
Therefore, even if the toner does not flow in from the toner inflow port (RT2a) and the toner is not conveyed to the toner discharge portion (44a), the bypass ports (46c, 46c ′, 46c ″ on the downstream side of the toner discharge portion (44a). 46d), the toner can be allowed to flow into the discharge member accommodating chamber (49), and the toner can be discharged and supplied from the toner container (RT), so that the toner supply to the toner container (RT) is in time. Even without this, it is possible to stably discharge the toner from the toner container (RT).

(First Embodiment 1)
The toner replenishing device according to Embodiment 1 of the first invention is characterized in that, in the first invention, the following structural requirement (A03) is provided.
(A03) The first transfer chamber (47) disposed between a first transfer direction (Yb) downstream end and a second transfer direction (Yc) upstream end of the second transfer chamber (48). Toner discharging part (44a).
(Operation of Form 1 of the First Invention)
In the toner replenishing device according to the first aspect of the first invention having the structural requirement (A03), the toner discharge portion (44a) includes a downstream end portion in the first transport direction (Yb) of the first transport chamber (47). It arrange | positions between the 2nd conveyance direction (Yc) upstream ends of the said 2nd conveyance chamber (48). Therefore, the toner stirred in the first transfer chamber (47) can be discharged from the toner discharge portion (44a).

(First Embodiment 2)
A toner replenishing device according to a second aspect of the first invention is the toner replenishing device according to the first invention or the first aspect of the first invention, characterized in that it comprises the following structural requirement (A04).
(A04) The toner in the second transfer chamber (48) is formed in the upstream portion of the second transfer chamber (48) in the second transfer direction (Yc) and flows into the discharge member storage chamber (49). The bypass port (46c).
(Operation of the second aspect of the first invention)
In the toner replenishing device according to the second aspect of the first invention having the structural requirement (A04), the bypass port (46c) is located upstream of the second transport chamber (48) in the second transport direction (Yc). The toner in the second transfer chamber (48) is formed and flows into the discharge member storage chamber (49). Accordingly, the toner in the upstream portion of the second transfer chamber (48) can be caused to flow into the discharge member storage chamber (49).

(Embodiment 3 of the first invention)
A toner replenishing device according to a third aspect of the first invention is characterized in that, in any one of the first invention and the first and second aspects of the first invention, the following structural requirement (A05) is provided.
(A05) The toner in the second transfer chamber (48) is formed in the downstream portion of the second transfer chamber (48) in the second transfer direction (Yc) and flows into the discharge member storage chamber (49). The bypass port (46c ').
(Operation of the third aspect of the first invention)
In the toner replenishing device according to the third aspect of the first invention having the structural requirement (A05), the bypass port (46c ′) is a downstream portion of the second transport chamber (48) in the second transport direction (Yc). The toner in the second transfer chamber (48) is caused to flow into the discharge member storage chamber (49). Accordingly, the toner in the downstream portion of the second transfer chamber (48) can be caused to flow into the discharge member accommodation chamber (49) from the bypass port (46c ').

(First aspect 4)
A toner replenishing device according to a fourth aspect of the first invention is characterized in that, in any one of the first invention and the first to third aspects of the first invention, the following structural requirement (A06) is provided.
(A06) Inflow side bypass ports (46c ″, 46d) formed in the first stirring chamber on the downstream side in the first transport direction (Yb) with respect to the toner inflow port (RT2a).
(Operation of the fourth aspect of the first invention)
In the toner replenishing device according to the fourth aspect of the first invention having the structural requirement (A06), the inflow-side bypass ports (46c ″, 46d) are arranged in the first transport direction (Yb) with respect to the toner inflow port (RT2a). Therefore, the toner flowing in from the toner inflow port (RT2a) can be promptly introduced into the discharge member accommodating chamber (49).

(Second invention)
In order to solve the technical problem, an image forming apparatus according to a second aspect of the invention includes the toner supply device according to any one of the first aspect and the first to fourth aspects of the first aspect.
(Operation of the second invention)
In the image forming apparatus of the second invention having the above-described constituent elements, since the toner replenishing device according to any one of the first invention and the first to fourth aspects of the invention is provided, toner flows in from the toner inlet (RT2a). Even if the toner is not conveyed to the toner discharge portion (44a), the toner is discharged from the bypass port (46c, 46c ′, 46c ″, 46d) on the downstream side of the toner discharge portion (44a). As a result, even if the toner supply to the toner container (RT) is not in time, the toner from the toner container (RT) can be discharged and supplied. Can be discharged stably.

The above-described present invention has the following effect (E01).
(E01) Even if the toner supply to the toner container is not in time, the toner can be stably discharged from the toner container.

Next, specific examples (examples) of the embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the following examples.
In order to facilitate understanding of the following description, in the drawings, the front-rear direction is the X-axis direction, the left-right direction is the Y-axis direction, the up-down direction is the Z-axis direction, and arrows X, -X, Y, -Y, The direction indicated by Z and -Z or the indicated side is defined as the front side, the rear side, the right side, the left side, the upper side, the lower side, or the front side, the rear side, the right side, the left side, the upper side, and the lower side, respectively.
In the figure, “•” in “○” means an arrow heading from the back of the page to the front, and “×” in “○” is the front of the page. It means an arrow pointing from the back to the back.

Example 1
FIG. 1 is an overall explanatory view of an image forming apparatus according to a first embodiment.
In FIG. 1, an image forming apparatus (digital copying machine) U according to the first embodiment includes an IIT (image input terminal) as an image reading unit, an IOT (image output terminal) as an image recording operation unit, and the IIT. Or it has the image forming apparatus main body U1 provided with IPS (image processing system) provided in IOT. On the platen glass PG on the upper surface of the IIT of the image forming apparatus main body U1, an automatic document feeder (ADF, auto document feeder) U2 for feeding a document to the IIT is disposed. A sheet discharge tray TRh is provided between the IIT and the IOT. A plurality of paper feed trays TR1 to TR4 for storing sheets are detachably attached to the image forming apparatus body U1.

In FIG. 1, the automatic document feeder U2 has a document feed tray TG1 on which a plurality of documents Gi to be copied are stacked. Each of the plurality of documents Gi placed on the document feed tray TG1 is sequentially passed through a copy position on the platen glass PG and discharged to the document discharge tray TG2.
The IIT as a document reading device disposed below the transparent platen glass PG on the upper surface of the image forming apparatus main body U1 includes an exposure system registration sensor (platen registration sensor) Sp disposed at a platen registration position (OPT position), and an exposure optical system. A.

The movement and stop of the exposure optical system A are controlled by the detection signal of the exposure system registration sensor Sp, and always stop at the home position.
In the ADF mode in which copying is performed using the automatic document feeder (auto document feeder) U2, the exposure optical system A passes through the copy position F1 on the platen glass PG in a state where the exposure optical system A is stopped at the home position. Each document Gi is exposed.
In the platen mode in which the document Gi is manually placed on the platen glass PG and copied, the exposure optical system A exposes and scans the document on the platen glass PG while moving.
The reflected light from the exposed document Gi passes through the exposure optical system A and is converged on a CCD (solid-state imaging device). The CCD converts the reflected document light converged on the imaging surface into an electric signal.

The IPS converts the read image signal input from the IIT CCD into a digital image write signal and outputs it to the IOT laser drive signal output device DL.
The laser drive signal output device DL outputs a laser drive signal corresponding to the input image data to the ROS (optical writing scanning device or image writing device).

  The photosensitive drum (image carrier) PR disposed below the ROS rotates in the direction of the arrow Ya. The surface of the photosensitive drum PR is charged by a charging roll (charge roll) CR in a charging area Q0, and then exposed and scanned by a laser beam L of the ROS (image writing apparatus) at a latent image writing position Q1. An electrostatic latent image is formed. The surface of the photosensitive drum PR on which the electrostatic latent image is formed rotates and moves sequentially through the development area Q2 and the sheet transfer area Q3.

A developing unit G that develops the electrostatic latent image in the developing area Q2 conveys a developer containing toner and a carrier to the developing area Q2 by a developing roll R0, and converts the electrostatic latent image passing through the developing area Q2 into toner. Develop to image. The toner image on the surface of the photosensitive drum PR is conveyed to the sheet transfer area Q3.
On the left side of the developing unit G, a toner replenishing device H for replenishing toner consumed by the developing unit G is disposed. The toner cartridge K of the toner replenishing device H is detachably mounted on the cartridge mounting member KS. The toner in the toner cartridge K is agitated in a reserve tank (toner container) RT and then conveyed to the developing device G through the toner conveying cylinder GH.

  A transfer unit (transfer belt support device) TU arranged opposite to the photosensitive drum PR in the sheet transfer region Q3 can be rotated by a belt support roll (Rd, Rf) having a drive roll Rd and a driven roll Rf. A transfer belt TB, a transfer roll TR, a peeling claw SC, a belt cleaner CLb for cleaning the transfer belt TB, and the like are supported. The transfer roll TR is a member that transfers the toner image on the surface of the photosensitive drum PR to the sheet S. A transfer voltage having a polarity opposite to the charging polarity of the developing toner used in the developing device G is supplied from the power supply circuit E. The The power supply circuit E is controlled by a controller C.

The sheets S accommodated in the sheet feed trays TR1 to TR4 are conveyed to the sheet transfer area Q3 through the sheet supply path SH1. That is, the sheets S of the respective trays TR1 to TR4 are taken out by the pickup roll Rp at a predetermined timing, separated one by one by the separating roll Rs, and conveyed to the registration roll Rr by the plurality of conveying rolls Ra. Further, the sheet S on the manual feed tray TRt is conveyed to the registration roll Rr by the conveyance roll Ra.
The sheet S conveyed to the registration roll Rr is conveyed from the pre-transfer sheet guide SG1 to the transfer belt TB of the transfer unit TU in synchronization with the timing when the toner image on the photosensitive drum PR moves to the sheet transfer area Q3. Is done. The transfer belt TB conveys the conveyed sheet S to the sheet transfer area Q3.

The toner image Tn developed on the surface of the photosensitive drum PR is transferred to the sheet S by the transfer roll TR in the sheet transfer region Q3. After the transfer, the surface of the photosensitive drum PR is cleaned by a photosensitive cleaner CLp to remove residual toner, and then recharged by the charging roll CR.
The sheet S on which the toner image has been transferred by the transfer roll TR in the sheet transfer area Q3 is peeled from the surface of the transfer belt TB by the sheet peeling claw SC on the downstream side of the sheet transfer area Q3. The peeled sheet S is a conveyance roll capable of rotating in the forward and reverse directions of the sheet discharge path SH2 through a mylar gate MG made of an elastic sheet after the toner image is heated and fixed by a fixing device F having a heating roll Fh and a pressure roll Fp. Transported to Rb. The mylar gate MG is elastically deformed to direct the sheet S that has passed through the fixing device F toward the sheet discharge path SH2.

  The sheet S to be discharged to the paper discharge tray TRh is transported through a sheet discharge path SH2 in which a transport roll Rb that can rotate forward and backward is disposed. A switching gate GT1 is disposed at the downstream end of the sheet discharge path SH2. When a post-processing device (not shown) is connected to the image forming apparatus, the switching gate GT1 discharges the conveyed sheet S to either the paper discharge tray TRh or a post-processing device (not shown). Is switched to. When the post-processing device is not mounted, the switching gate GT1 discharges the sheet S conveyed to the downstream end portion of the sheet discharge path SH2 to the discharge tray TRh.

The forward and reverse rotatable transport roll Rb rotates reversely immediately before the trailing edge of the single-side recorded sheet S passes through the transport roll Rb when a single-side recorded sheet for duplex copying is transported. The single-side recorded sheet S is switched back. The mylar gate MG directs the sheet S that has been switched back by the transport roll Rb to the sheet circulation transport path SH3. The single-side recorded sheet S conveyed to the sheet circulation conveyance path SH3 is retransmitted to the transfer area Q3 in a state where the front and back sides are reversed. The one-side recorded sheet S retransmitted to the sheet transfer area Q3 is transferred with the toner image on the second side.
Note that the sheet conveying device SH is composed of the components indicated by the symbols SH1 to SH3, Rp, Rs, Rr, Ra, Rb, MG and the like.

(Cartridge mounting member, reserve tank and cartridge)
FIG. 2 is a perspective view of the reserve tank and the cartridge mounting portion of the image forming apparatus according to the first exemplary embodiment.
FIG. 3 is a cross-sectional view illustrating a state where the toner cartridge of the image forming apparatus according to the first exemplary embodiment is mounted on the cartridge mounting unit.
2 to 3, the cartridge mounting portion KS of the toner replenishing device H includes a rear cylindrical portion 21, a front half cylindrical portion 22, and a rear end wall 23. A guide groove 22a extending in the front-rear direction and a supply port 22b connected to the rear end of the guide groove 22a are formed in the lower part of the inner surface of the front semi-cylindrical portion 22. The rear end wall 23 is formed with two arc-shaped positioning pin insertion holes 23a, 23a. A rotating shaft 25 is rotatably supported at the center of the rear end wall 23 via a bearing 24. A coupler 26 is fixed to the front end of the rotary shaft 25 penetrating the rear end wall 23, and a gear G1 is fixed to the rear end. Rotation is transmitted to the gear G1 from a cartridge motor (not shown).

  In FIG. 3, the toner cartridge K which is detachably mounted on the cartridge mounting portion KS has a container 28 for storing replenishing toner. An operation handle 29 is provided on the front surface of the front end wall of the container 28. Positioning pins 30 are provided on the rear end wall of the container 28 so as to protrude rearward. A coupler shaft 31a passes through the center of the rear end wall of the container 28, and a coupler 31 is formed at the rear end of the coupler shaft 31a. The rear end of an agitator (toner supply member) 32 is connected to the front end of the coupler shaft 31a. A toner discharge opening 33, a guide rail 34 extending in the circumferential direction, and a shutter 35 that is guided by the guide rail 34 and is movable in the circumferential direction are provided at the rear portion of the cylindrical wall of the container 28.

In FIG. 3, when the toner cartridge K is inserted from the front to the rear (−X direction), the guide rail 34 and the shutter 35 of the toner cartridge K are guided by the guide groove 22a of the cartridge mounting portion KS and move backward. When the toner cartridge K is further inserted rearward from the state of FIG. 3, the pins 30 and 30 are inserted into the arc-shaped positioning pin insertion holes 23a and 23a. In the inserted state, the coupler 31 of the toner cartridge K and the coupler 26 of the cartridge mounting portion KS are coupled.
When the toner cartridge K is rotated in the inserted state, the container 28 and the guide rail 34 are rotated while the shutter 35 is stopped without rotating. At that time, the opening 33 rotates and moves to a position communicating with the supply port 22b (see FIGS. 2 and 3). Since the replenishing port 22b is connected to the inside of the reserve tank RT, it is possible to replenish toner for replenishment inside the toner cartridge K into the reserve tank RT from the opening 33 and the replenishing port 22b.

4 is a plan view of the reserve tank shown in FIG.
FIG. 5 is an explanatory view showing a state in which the agitator and the partition member of the reserve tank of FIG. 4 are removed.
6 is a sectional view taken along line VI-VI in FIG.
2 and 4, the reserve tank RT includes a container body RT1 and a cover RT2 that closes the upper end opening of the container body RT1.
4 to 6, the container body RT1 accommodates toner conveying portions 42, 43 formed on the left and right sides, and a semi-cylindrical discharge member formed to be recessed downward inside the circulation conveying portions 42, 43. Part 44. A partition member 46 having a shorter front end side than the container body RT1 is supported above the discharge member accommodating portion 44. Therefore, the front end portions of the toner conveying portions 42 and 43 are communicated with each other by the partition member 46 shorter than the container main body RT1, and a toner discharge portion 44a is formed between the front end of the partition member 46 and the discharge member accommodating portion 44. The

The partition member 46 is formed to cover the upper surface of the discharge member storage portion 44 and partition the discharge member storage portion 44 and the toner transport portions 42 and 43, and to protrude upward from the cover portion 46a. A partition wall 46b that partitions between the conveyance units 42 and 43 and communicates both front and rear ends of the toner conveyance units 42 and 43; In FIG. 4, a bypass port 46 c (see FIGS. 4 and 6) is formed on the front (+ X side) portion of the partition member 46 on the second toner transport portion 43 side, and the first toner transport portion 42 side is formed. An inflow side bypass port 46d (see FIG. 4) is formed in the rear side (−X side) portion.
Accordingly, the first transfer chamber 47 is formed by the space surrounded by the first toner transfer portion 42 and the partition wall 46b, and the second transfer chamber 48 is formed by the space surrounded by the second toner transfer portion 43 and the partition wall 46b. Is formed. The first transfer chamber 47 and the second transfer chamber 48 constitute a toner circulation chamber (47 + 48). In addition, a member storage chamber 49 having a toner discharge portion (toner inflow portion) 44a at the front end is formed by the space surrounded by the covering portion 46a and the discharge member storage portion 44. A flexible toner transport cylinder GH extending to the developing device G is connected to the front of the discharge member accommodating chamber 49, and the toner is discharged (supplied) to the developing device G at the tip of the toner transport tube GH. A toner discharge port GH1 is formed.

In FIG. 4, the first transfer chamber 47 accommodates a spiral first agitator 51 as a first transfer member, and the second transfer chamber 48 has a spiral second agitator 52 as a second transfer member. Contained. The rear ends of the agitators 51 and 52 are supported by agitator support members 53 and 54 that are rotatably supported by the rear end wall of the container body RT1.
In FIG. 5, a spiral discharge agitator 56 as a toner discharge member is stored in the discharge member storage chamber 49, and the tip of the discharge agitator 56 is inserted into the toner transport cylinder GH and extends to the toner discharge port GH1. Yes. The rear end portion of the discharge agitator 56 is supported by an agitator support member 57 that is rotatably supported by the rear end wall of the container body RT1.

The rear end portions of the agitator support members 53, 54, and 57 protrude outward through the container body RT1, and gears G2, G3, and G4 are fixed to the rear ends. The gears G2 to G4 are engaged with each other, and rotation is transmitted from a reserve tank motor (not shown), so that the agitators 51, 52, and 56 rotate. As the agitators 51 and 52 rotate, the toner in the first transport chamber 47 is transported in the first transport direction (see arrow Yb in FIG. 4), and the toner in the second transport chamber 48 is transported in the second transport direction (see FIG. 4). (See arrow Yc in FIG. 4). As a result, the toner in the toner circulation chamber (47 + 48) is circulated and conveyed while being agitated by the agitators 51 and 52. Therefore, the agitator 51, 52 constitutes a circulating conveyance member (51 + 52). In Example 1, the winding direction, the inclination angle, and the rotation direction of the agitator are set so that the second agitator 52 conveys the toner in the second conveyance direction and brings the toner toward the partition wall 46b.
As the discharge agitator 56 rotates, the toner in the discharge member storage chamber 49 is transported in the toner discharge direction (see arrow Yd in FIG. 5) and is transported through the toner transport cylinder GH.

The cover RT2 of the reserve tank RT has a toner inlet RT2a formed at a position corresponding to the supply port 22b (see FIG. 2), and the upstream portion of the first transfer chamber 47 in the first transfer direction through the toner inlet RT2a. Toner flows into the toner cartridge K.
A toner sensor unit SN is disposed in the first transfer chamber 47 below the toner inlet RT2a, and detects toner in the vicinity.

(Operation of Example 1)
In the image forming apparatus U of Embodiment 1 having the above-described configuration, the toner flowing into the reserve tank RT from the toner inlet RT2a is circulated and conveyed while being stirred in the toner circulation chamber (47 + 48). When the toner being circulated and conveyed reaches the toner discharge portion 44a, a part of the toner is supplied to the developing device G by the discharge agitator 56 through the toner transfer cylinder GH. In the reserve tank RT according to the first embodiment, the bypass port 46c is formed. Therefore, even if the toner does not flow from the first transfer chamber 47 through the toner discharge port 44a, the toner transferred in the second transfer chamber 48 is used. Part of the toner flows into the discharge member housing chamber 49 through the bypass port 46 c and is supplied to the developing device G.
When the toner in the toner cartridge K becomes empty, it is detected that the toner does not flow in from the toner inflow port RT2a and does not flow in in the toner sensor unit SN. Then, image formation is continued with the toner in the reserve tank RT.

  Therefore, in the image forming apparatus U according to the first embodiment, when image formation is continued with the toner cartridge K being empty, the replacement of the toner cartridge K is delayed, and the amount of toner in the reserve tank RT decreases. The toner on the downstream side of the toner inlet RT2a is almost eliminated. At this time, the toner that flows from the toner discharge portion 44a to the discharge member storage chamber 49 tends to be insufficient, but the toner that flows into the discharge member storage chamber 49 through the bypass port 46c can be continuously supplied to the developing device G. . As a result, in the image forming apparatus U according to the first embodiment, it is possible to reduce the occurrence of a decrease in toner density in the developing unit G, and it is possible to reduce the occurrence of image defects. In particular, in the image forming apparatus U according to the first embodiment, since the second agitator 52 conveys the toner so as to approach the partition wall 46b, the toner easily flows into the bypass port 46c, thereby reducing the occurrence of a decrease in toner density. Easy to do.

Further, in the image forming apparatus U according to the first embodiment, since image formation defects can be reduced, the image forming operation is interrupted to fill the reserve tank RT with toner when the toner cartridge K is replaced, and the toner density is reduced. It is possible to reduce the case where the image formation has to be interrupted because the value becomes too low. Therefore, productivity can be improved.
Furthermore, since the inflow-side bypass port 46d is formed in the image forming apparatus U according to the first exemplary embodiment, one of the toners transferred from the second transfer chamber 48 to the first transfer chamber 47 after passing through the toner discharge portion 44a. The portion can flow into the discharge member accommodating chamber 49 through the inflow side bypass port 46d and be replenished to the developing device G. In addition, since a part of the toner replenished from the new toner cartridge K after replacement can be allowed to flow into the discharge member accommodating chamber 49 from the inflow side bypass port 46d, the toner is first transported without providing the bypass port 46d. Compared to the case where the chamber 47 is transported, it can be expected that the chamber 47 is transported to the developing device G even a little faster.

FIG. 7 is an explanatory diagram of a reserve tank of the image forming apparatus according to the second embodiment of the present invention, and corresponds to FIG. 4 according to the first embodiment.
In the description of the second embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The second embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 7, in the reserve tank of the image forming apparatus according to the second embodiment, the position of the bypass port 46c ′ is provided on the downstream side in the second transport direction Yc as compared with the first embodiment.

(Operation of Example 2)
In the image forming apparatus U of Example 2 having the above-described configuration, the bypass port 46c ′ is disposed on the downstream side in the second transport direction Yc. The toner transported in the second transport direction Yc by the second agitator 52 tends to concentrate on the downstream end portion and easily accumulate, so that the bypass port 46c ′ is formed on the downstream side where the toner distribution amount is large. The forming device U easily allows the toner to flow into the discharge member accommodation chamber 49 from the bypass port 46c ′. Further, the image forming apparatus U according to the second exemplary embodiment is farther from the toner discharging unit 44a than the first exemplary embodiment. Accordingly, the distance of the toner discharge portion 44a from the position corresponding to the bypass port 46c ′ of the discharge member storage chamber 49 is increased, and the amount of toner stored in the discharge member storage chamber 49 is increased, so that the toner is discharged more stably. it can. As a result, the occurrence of a decrease in toner density in the developing device G can be further reduced.

FIG. 8 is an explanatory diagram of a reserve tank of the image forming apparatus according to the third embodiment, and corresponds to FIG. 4 according to the first embodiment.
In the description of the third embodiment, components corresponding to those of the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
The third embodiment is different from the first embodiment in the following points, but is configured in the same manner as the first embodiment in other points.
In FIG. 8, in the reserve tank RT of the third embodiment, a discharge member storage chamber 49 partitioned by partition walls 46b and 46b is disposed between the first transfer chamber 47 and the second transfer chamber 48, and the discharge member storage chamber. A toner discharge port 49a is formed at a downstream end portion of the toner discharge direction Yd. A bypass port (inflow side bypass port) 46c ″ is formed from the central portion of the partition wall 46b on the first transfer chamber 47 side in the first transfer direction Yb to the downstream portion.
A discharge auger 56 ′ serving as a toner discharge member is stored in the discharge member storage chamber 49. One end of the discharge auger 56 ′ passes through the partition wall 46 b of the discharge member housing chamber 49 and protrudes into the communication portion 61 of the first transfer chamber 47 and the second transfer chamber 48. A paddle 62 for conveying toner from the first transfer chamber 47 side to the second transfer chamber 48 side is supported.

  Therefore, in the reserve tank RT according to the third embodiment, the toner in the toner cartridge K flows from the toner inflow port RT2a into the upstream end portion of the first transfer chamber 47 in the first transfer direction Yb, and the downstream end of the first transfer chamber 47. It is conveyed while being stirred by the part. The toner in the first transfer chamber 47 is transferred to the upstream end of the second transfer chamber 48 by the paddle 62. The toner at the upstream end of the second transfer chamber 48 is transported to the downstream end and flows into the toner discharge portion 44a. A part of the toner in the toner discharge portion 44a is transferred to the discharge member storage chamber 49 side (toner discharge direction Yd) by the discharge auger 56 ', and is transferred to the toner discharge port 49a. The toner passes through the toner discharge portion 44 a and flows into the upstream end portion of the first transfer chamber 47. Therefore, the toner in the reserve tank RT is circulated and conveyed through the toner circulation chamber (47 + 48).

(Operation of Example 3)
The image forming apparatus according to the third embodiment having the above configuration has the same operations and effects as the first and second embodiments.

(Example of change)
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example, A various change is performed within the range of the summary of this invention described in the claim. It is possible. Modification examples (H01) to (H05) of the present invention are exemplified below.
(H01) The present invention is not limited to a copying machine, but can be applied to a post-processing apparatus of an image forming apparatus such as a printer, a FAX, or a multifunction machine. Further, the present invention is not limited to a monochrome image forming apparatus, and can be applied to a full color image forming apparatus.

(H02) In the embodiment, the inflow side bypass port 46d can be omitted. Conversely, both the bypass port 46c of the first embodiment and the bypass port 46c 'of the second embodiment can be provided, and three or more bypass ports can be provided.
(H03) In the above-described embodiment, the positions where the bypass ports 46c, 46c ′, 46c ″ are arranged can be changed to any position downstream of the toner discharge portion 44b. However, the position is located downstream of the toner inlet RT2a. If arranged, the toner aggregated without being sufficiently stirred may be replenished to the developing device. Therefore, it is desirable to arrange the toner on the downstream side of the toner discharge portion 44b and the upstream side of the toner inflow port RT2a.

(H04) In the above-described embodiment, the agitators 51, 52, and 56 are illustrated as the toner conveying members. However, any toner conveying member such as an auger can be used.
(H05) In the above embodiment, a shutter for opening and closing the bypass ports 46c, 46c ', 46c ", 46d is provided, and the bypass port is normally closed by the shutter to detect that the toner cartridge is empty. It is also possible to configure so that the bypass port is opened until the cartridge is replaced.

FIG. 1 is an overall explanatory view of the image forming apparatus according to the first embodiment. FIG. 2 is a perspective view of the reserve tank and the cartridge mounting portion of the image forming apparatus according to the first exemplary embodiment. FIG. 3 is a cross-sectional view illustrating a state where the toner cartridge of the image forming apparatus according to the first exemplary embodiment is mounted on the cartridge mounting unit. 4 is a plan view of the reserve tank shown in FIG. FIG. 5 is an explanatory view showing a state in which the agitator and the partition member of the reserve tank of FIG. 4 are removed. 6 is a sectional view taken along line VI-VI in FIG. FIG. 7 is an explanatory diagram of a reserve tank of the image forming apparatus according to the second embodiment of the present invention, and corresponds to FIG. 4 according to the first embodiment. FIG. 8 is an explanatory diagram of a reserve tank of the image forming apparatus according to the third embodiment, and corresponds to FIG. 4 according to the first embodiment.

Explanation of symbols

44a ... Toner discharging part,
46c, 46c ', 46c ", 46d ... bypass port,
46c ", 46d ... inflow side bypass port,
47. First transfer chamber,
47 + 48 ... toner circulation chamber,
48 ... second transfer chamber,
49 ... discharge member storage chamber,
51 ... 1st conveyance member,
52 ... Second conveying member,
56. Toner discharging member,
RT ... toner container,
RT2a ... Toner inlet,
Yb ... 1st conveyance direction,
Yc: Second transport direction.

Claims (6)

A toner replenishing device comprising the following structural requirements (A01) and (A02):
(A01) A first transport chamber that houses a first transport member that transports toner flowing in from a toner inflow port in a predetermined first transport direction, and transports the toner in a second transport direction different from the first transport direction. A second circulation chamber that accommodates the second conveyance member and communicates with the first conveyance chamber at an upstream portion and a downstream portion in the first conveyance direction, and a toner circulation chamber in which toner is circulated and conveyed,
A discharge member storage chamber having a toner discharge portion through which toner circulating in the toner circulation chamber passes, the discharge member storage chamber storing a toner discharge member for discharging the toner in the discharge member storage chamber;
A toner container,
(A02) A bypass port formed on the downstream side of the toner discharge portion in the toner circulation direction and through which the toner in the toner circulation chamber on the downstream side of the toner discharge portion flows into the discharge member storage chamber. The toner replenishing device according to claim 1, comprising the following structural requirements (A03):
(A03) The toner discharge portion disposed between the downstream end portion in the first transport direction of the first transport chamber and the upstream end portion in the second transport direction of the second transport chamber. The toner replenishing device according to claim 1, wherein the toner replenishing device comprises:
(A04) The bypass port, which is formed in an upstream portion of the second transfer chamber in the second transfer direction and allows the toner in the second transfer chamber to flow into the discharge member storage chamber. The toner replenishing device according to any one of claims 1 to 3, comprising the following structural requirements (A05):
(A05) The bypass port, which is formed in a downstream portion of the second transfer chamber in the second transfer direction and allows the toner in the second transfer chamber to flow into the discharge member storage chamber. The toner replenishing device according to any one of claims 1 to 4, further comprising the following constituent (A06):
(A06) An inflow-side bypass port formed in the first stirring chamber on the downstream side in the first transport direction with respect to the toner inflow port. An image forming apparatus comprising the toner replenishing device according to claim 1.

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