Image forming apparatus

Description: TECHNICAL FIELD [Detailed description of the invention]

【0001】

[Technical field to which the invention belongs]

The present invention relates to an image forming apparatus that superimposes a plurality of developing agents to form an image on a recording material and reuses the developing agent remaining on the image carrier after transfer.

【0002】

[Conventional technology]

The multicolor image forming apparatus of the prior art has a plurality of photoconductor drums and a plurality of developing means, and each developing means attaches toner of a different color to the photoconductor drum for each photoconductor drum. Toner images of different colors are formed for each photoconductor drum depending on the developing means. As the recording material moves from the upstream side to the downstream side in the transport direction, the toner image formed on each photoconductor drum is sequentially transferred to the recording material. As a result, a plurality of toners are superposed on the recording material to form a multicolor image.

【0003】

The toner adhering to the photoconductor drum is not completely transferred to the recording material during transfer, and some toner remains on the photoconductor drum after transfer. Further, even when creating a patch image formed on the photoconductor drum for adjusting the image density, some toner remains on the photoconductor drum.

【0004】

In addition, a reverse transfer phenomenon occurs in which the toner adhering to the recording material in the transfer process in the first stage moves to the photoconductor drum in the transfer process in the second stage. The toner adhering to the photoconductor drum in the subsequent stage is mixed by the toner transferred from the recording material.

【0005】

The residual toner remaining on the photoconductor drum after transfer is removed from the photoconductor drum by cleaning means. As the photoconductor drum shape is formed in the subsequent stage, a large amount of different color toner is mixed in the residual toner. Residual toner is contained in a disposal container and discarded. The multicolor image forming apparatus of the conventional technique does not effectively utilize the residual toner, consumes a large amount of toner, and has a problem of poor economy.

【0006】

As a second conventional technique for solving the problem of the image forming apparatus of the above-mentioned conventional technique, there is an image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 61-196268. In the image forming apparatus of the second conventional technique, a recovery path for collecting the toner removed from the first photoconductor drum in which the first transfer step is performed and a subsequent toner removed from the photoconductor drum in the subsequent stage are guided. A transport path to be taken is provided separately.

【0007】

The residual toner removed from the first photoconductor drum moves through the recovery path, is housed in the developing means again, and is reused for image formation. The residual toner removed from other than the first photoconductor drum moves along the transport path, is stored in the disposal container, and is discarded. As described above, in the multicolor image forming apparatus of the second conventional technique, a plurality of passages through which the toner moves are provided, and the toner removed from the first photoconductor drum, which is not mixed with different color toner due to reverse transfer, is re-used. Use and discard the toner that is removed from the other photoconductor drums.

【0008】

[Problems to be Solved by the Invention]

In the multicolor image forming apparatus disclosed in Japanese Patent Application Laid-Open No. 61-196268 described above, a collection path for moving the recycled toner and a transport path for moving the discarded toner are separately provided. Therefore, it is necessary to provide a drive source for each passage of each toner and for each toner to move in each passage. Therefore, there is a problem that the structure of the image forming apparatus becomes complicated and the number of parts constituting the image forming apparatus increases. There is also a problem that it is uneconomical because the parts cost and the assembly cost cannot be reduced.

【0009】

Therefore, an object of the present invention is that in an image forming apparatus that forms an image using a plurality of developing agents, each developing agent remaining on each photoconductor drum after transfer can be removed, and the removed developing agent can be reused. Moreover, the structure provides a simple image forming apparatus.

【0010】

[Means for solving problems]

The present invention is commonly provided in connection with a plurality of image forming stations that sequentially superimpose on a recording material to form a developer image by a developer, and is a transport path through which a waste developer generated at the time of forming the developer image is guided. Is formed, and a transport path forming portion in which discharge holes for discharging the waste developer are formed at both ends, and a transport means provided by inserting the transport path and rotating to transport the waste developer in the transport path. Therefore, the waste developing agent closer to one end than the predetermined position in the transport path is conveyed toward one end, and the waste developing agent closer to the other end than the predetermined position is conveyed toward the other end. An image forming apparatus including means.

【0011】

According to the present invention, a common transport path forming portion is provided for a plurality of image forming stations, and a waste developing agent closer to one end than a predetermined position in the transport path is applied to the transport path forming portion by the transport means. In addition to transporting toward one end, the waste developing agent closer to the other end than the predetermined position in the transport path is conveyed toward the other end of the transport path forming portion. As a result, each waste developing agent can be separated from a predetermined position of the transport path and moved to each discharge hole formed at both ends of the transport path forming portion. That is, the waste developing agent that moves in the common transport path can be divided into two parts in the transport path and transported to the two discharge holes separately. Since the image is transported on a common transport path, it is not necessary to provide a transport path and a transport means for each image forming station. In addition, the number of parts can be reduced, the configuration can be simplified, and the parts cost and the assembly cost can be reduced.

【0012】

Further, in the present invention, the transport means is a rotating shaft and a spiral blade body that is spirally provided on the rotating shaft by rotating its outer periphery, and is provided on a portion on one end side and a portion on the other end side from the predetermined position. It is characterized by having a spiral blade having a different winding direction from the above.

【0013】

According to the present invention, the spiral blade rotates around the axis of the rotation axis to scrape the waste developing agent guided into the transport path, transports the waste developing agent in the direction in which the rotation shaft extends, and screws the so-called waste developing agent. Transport. Since the winding direction of the spiral blade differs at a predetermined position, the waste developing agent located on the one end side of the transport path from the predetermined position is transported to the discharge hole at one end of the transport path forming portion, and is more than the predetermined position. The waste developing agent located on the other end side of the transport path forming portion can be discharged to the discharge hole at the other end portion of the transport path forming portion. As a result, the waste developing agent guided to the transport path can be divided into two and transported to each discharge hole.

【0014】

Further, the spiral blade serves as a partition for partitioning the inside of the transport path, and can prevent the waste developing agent from flowing back in the direction of transport. The transport path is formed with a rotation shaft that passes through the transport path and a region for accommodating the spiral blade, and a rotation drive mechanism can be provided outside the transport path.

【0015】

Further, in the present invention, the predetermined position is a position where the waste developing agent is guided from the first-stage image forming station in which the image forming order is the first among the image forming stations, and the image forming order is the first-stage image forming station. It is characterized in that it is located between the position where the waste developer is guided from the second stage image forming station next to the above.

【0016】

According to the present invention, a predetermined position is provided between the position where the waste developer is guided from the first-stage image forming station and the position where the waste developer is guided from the second-stage image forming station. As a result, the waste developing agent generated at the first-stage image forming station can be conveyed to the discharge hole at one end of the transport path forming portion, and other image forming is performed later than the first-stage image forming station. The waste developer generated at the station can be transported to the discharge hole at the other end of the transport path forming portion. It is possible to prevent other waste developing agents from being mixed with the waste developing agent generated in the first stage image forming station and to convey the waste developing agent to the discharge hole at one end of the transport path forming portion.

【0017】

The present invention is also characterized in that the first-stage image forming station forms a developer image with an achromatic developer.

【0018】

According to the present invention, the first stage image forming station forms a developer image with an achromatic developer. The color of the achromatic developer is realized by a low-brightness color such as black. The waste developing agent generated in the image forming station other than the first stage image forming station moves from a predetermined position in the transport path toward one end of the transport path forming portion, and the waste developing agent generated in the first stage image forming station. Even if the colors are mixed, the waste developing agent generated at the first-stage image forming station is achromatic, so that the waste developing agent discharged from the discharge hole at one end of the transport path forming portion is a color due to the color mixing. The effect of changes in is reduced. As a result, the waste developing agent discharged from the discharge hole at one end of the transport path forming portion can be accommodated in the first stage image forming station again as a developing agent used for image forming and reused.

【0019】

Further, the present invention is characterized in that a collecting means for collecting the waste developing agent discharged from the discharge hole formed at one end of the transport path forming portion is provided in the first stage image forming station.

【0020】

According to the present invention, the waste developing agent discharged from the discharge hole formed at one end of the transport path forming portion can be recovered to the first stage image forming station by the collecting means, so that the first stage image can be collected. The waste developer generated at the forming station can be reused. In addition, it is possible to save the labor of the operator collecting the waste developing agent discharged from the discharge hole at one end of the transport path forming portion and collecting the collected waste developing agent in the first stage image forming station, which is convenient. Can be improved.

【0021】

Further, the present invention is characterized in that the second-stage image forming station forms a developer image with a developer having a color scheme that is less visible than the color of the developer of the first-stage image forming station.

【0022】

According to the present invention, the second-stage image forming station forms a developer image with a developer having a color scheme that is less visible than the developer color of the first-stage image forming station. As a result, even if the waste developing agent generated at the first-stage image forming station and the waste developing agent generated at the second-stage image forming station may be mixed in the transport path, the mixed color of the waste developing agent is the first. It is possible to prevent the color of the waste developing agent generated in the two-stage image forming station from being conspicuous, and to reduce the influence of the color change of the mixed waste developing agent. As a result, the waste developer generated at the first-stage image forming station and discharged from the discharge hole at one end of the transport path forming portion can be reused as the developing agent used for image forming again.

【0023】

Further, in the present invention, the predetermined position is a position where the waste developing agent is guided from the first-stage image forming station in which the image forming order is the first among the image forming stations, and the image forming order is the first-stage image forming station. It is characterized in that it is between the position where the waste developing agent is guided from the second-stage image forming station next to the above and the position where the waste developing agent is guided from the first-stage image forming station.

【0024】

According to the present invention, the waste developing agent generated from the first-stage image forming station can be conveyed to the discharge hole at one end of the transport path forming portion, and the image forming order is later than that of the first-stage image forming station. The waste developer generated from the station can be transported to the discharge hole at the other end of the transport path forming portion.

【0025】

Since the predetermined position is provided near the position where the waste developing agent is guided from the first-stage image forming station, the waste developing agent generated at the second-stage image forming station exceeds the predetermined position and is transported from the predetermined position. It becomes more difficult to move to one end side of the forming portion. As a result, it is possible to prevent other developing agents from being mixed with the waste developing agent generated from the first-stage image forming station, and to convey the waste developing agent to the discharge hole at one end of the transport path forming portion.

【0026】

Further, in the present invention, each image forming station is provided with an image carrier on which an electrostatic latent image is formed, a developing means for developing an electrostatic latent image to form a developer image on the image carrier, and an image carrier. It is characterized by having a transfer means for transferring the formed developer image to a recording material and a cleaning means for removing the developer remaining on the image carrier after the transfer.

【0027】

According to the present invention, each image forming station develops an electrostatic latent image formed on an image carrier as a developer image by a developing means, and a transfer means develops a developer image formed on each image carrier. Transfer to recording material in sequence. The developer remaining on the image carrier as a waste developer after transfer is removed by cleaning means. In the configuration in which the developer image is fixed after the developer images are sequentially superimposed on the paper, the waste developer generated at the image forming station in which the image forming order is later is the development of the developer image formed on the paper before. A reverse transcription phenomenon in which the agent is mixed may occur. When the reverse transfer phenomenon occurs, the waste developer is mixed with the mixed developer. According to the above invention, the waste developing agent transported in the transport path can be separated, and the waste developing agent that is mixed by the reverse transfer phenomenon and the waste developing agent that is not affected by the reverse transfer phenomenon and is not mixed are separated. Separately, the waste developer can be easily collected or reused. Thereby, it is possible to suitably realize the recovery and reuse of the waste developing agent generated in the image forming station using the image carrier.

【0028】

For example, the waste developing agent generated at the first stage image forming station is not affected by the reverse transfer phenomenon, and the waste developing agent guided from the first stage image forming station to the transport path is mixed with other waste developing agents. There is no. By discharging the waste developing agent generated in the first-stage image forming station from one discharge hole at one end of the transport path forming portion, the waste developing agent discharged from one of the discharge holes is converted into the first-stage image forming station. It is possible to reduce the possibility that the waste developer generated in other than the above is mixed.

【0029】

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a cross-sectional view showing a simplified main configuration of an image forming apparatus 1 according to an embodiment of the present invention. The image forming apparatus 1 forms a multicolor image by sequentially superimposing a plurality of toner images of different colors on a cut sheet-like paper which is a recording material. The image forming apparatus 1 includes a plurality of, for example, four image forming stations Pa, Pb, Pc, Pd, a paper transport belt (not shown), a transport path forming unit 3, a transport means 4, a disposal container 5, and a collection path. It is configured to include the forming portion 6. Each image forming station Pa to Pd develops the photoconductor drums 22a to 22d on which the electrostatic latent image is formed and the electrostatic latent image formed on the photoconductor drums 22a to 22d to form a toner image. Means 24a to 24d, transfer means (not shown) for transferring the toner image formed on the photoconductor drums 22a to 22d to paper, and cleaning means for removing residual toner which is a waste developing agent remaining on the photoconductor drums 22a to 22d. It is equipped with 26a to 26d.

【0030】

Each developing means 24a to 24d has toner tanks 11a to 11d for accommodating toners which are developing agents having different colors. Each of the developing means 24a to 24d adheres toner to each of the photoconductor drums 22a to 22d on which an electrostatic latent image is formed to form a toner image. The image forming apparatus 1 sequentially transfers the toner images formed for each of the photoconductor drums 22a to 22d onto the paper, and superimposes the toners of each color on the paper to form a multicolor image.

【0031】

Toner that has not been transferred to the recording paper remains on the outer peripheral surface of each of the photoconductor drums 22a to 22d after the transfer. Each of the cleaning means 26a to 26d removes each residual toner remaining on each of the photoconductor drums 22a to 22d from each of the photoconductor drums 22a to 22d.

【0032】

The four image forming stations Pa to Pd having the above-described configuration are arranged side by side in a row. The paper transport belt is arranged parallel to the direction in which the four image forming stations Pa to Pd are lined up, and is arranged so as to face the photoconductor drums 22a to 22d of each image forming station Pa to Pd. The paper transport belt sucks and transports the paper by electrostatic adsorption, and transports the paper so as to be sequentially close to or in contact with the photoconductor drums 22a to 22d of the image forming stations Pa to Pd. In other words, four image forming stations Pa to Pd are lined up along the paper transport direction C.

【0033】

The first-stage image forming station Pa, which is arranged on the most upstream side of the paper transport direction C among the four image forming stations Pa to Pd, is an image forming station that forms a black toner image with the image forming order first. Therefore, black toner is stored in the developing means 24a. The second-stage image formation station Pb on the downstream side of the paper transport direction C of the first-stage image formation station Pa is an image formation station that forms a yellow toner image in the order of image formation next to the first-stage image formation station. Therefore, the yellow toner is stored in the developing means 24b. The third-stage image forming station Pc on the downstream side of the paper transport direction C of the second-stage image forming station Pb is an image forming station that forms a cyan-colored toner image, and the cyan-colored toner is stored in the developing means 24c. Toner. The fourth-stage image forming station Pd on the downstream side of the paper transport direction C of the third-stage image forming station Pc is an image forming station that forms a magenta-colored toner image, and the magenta-colored toner is stored in the developing means 24d. Toner.

【0034】

The transport path forming portion 3 is formed in a substantially cylindrical shape, extends parallel to the direction in which the four image forming stations Pa to Pd are lined up, and extends in substantially the same direction as the paper transport belt. The transport path forming portion 3 is formed in a bottomed tubular shape that closes both end surfaces in the axial direction, and the internal space of the transport path forming portion 3 is formed as a transport path 7 through which residual toner is conveyed. One end in the axial direction of the transport path forming portion 3 is arranged on the Pa side of the first stage image forming station Pa in a state where the transport path forming portion 3 is configured as a part of the image forming apparatus 1.

【0035】

Discharge holes 9a and 9b through which the transport path forming portion 3 is inserted in the radial direction are formed in both end portions 3a and 3b in the axial direction of the transport path forming portion 3, and the transport is performed at a position between both end portions 3a and 3b in the axial direction. Four insertion holes 10a to 10d are formed through the path forming portion 3 in the radial direction.

【0036】

The residual toner removed from the photoconductor drums 22a to 22d by the cleaning means 26a to 26d passes through the insertion holes 10a to 10d and is transported to the transport path 7. The residual toner is inserted through the transport path 7 and discharged from the two discharge holes 9a and 9b.

【0037】

Each of the insertion holes 10a to 10d is provided so as to communicate with each of the cleaning means 26a to 26d and the transport path 7 in a state where the transport path forming portion 3 constitutes a part of the image forming apparatus 1. The first insertion hole 10a through which the residual toner generated in the first-stage image forming station Pa passes is formed closer to one of the four insertion holes 10a to 10d, the discharge hole 9a. The second insertion hole 10b through which the residual toner generated at the second-stage image forming station Pb passes is formed on the opposite side of the transport path forming portion 3 in the axial direction with respect to the first insertion hole 10a. Similarly, the third insertion hole 10c through which the residual toner generated at the third-stage image forming station Pc passes is formed on the opposite side of the transport path forming portion 3 in the axial direction with respect to the second discharge hole 10b. .. The fourth insertion hole 10d through which the residual toner generated in the fourth-stage image forming station Pd passes is formed on the opposite side of the transport path forming portion 3 in the axial direction with respect to the third discharge hole 10c.

【0038】

With the transport path forming portion 3 forming a part of the image forming apparatus 1, the discharge holes 9a and 9b are formed in the lower part of the transport path forming portion 3, and the insertion holes 10a to 10d are the transport path forming portions. Formed on top of 3. For example, the transport path forming portion 3 is provided below each cleaning means 26a to 26d. As a result, the residual toner removed by the cleaning means 26a to 26d moves downward by gravity from the insertion holes 10a to 10d and falls into the transport path 7. Therefore, a mechanism for guiding the cleaning means 22a to 26d to the transport path 7 is not required. Further, since the discharge holes 9a and 9b are provided below the transport path forming portion 3, the residual toner conveyed to both end portions 3a and 3b of the transport path forming portion 3 passes through the discharge holes 9a and 9b and is downward. Fall towards. Therefore, it is not necessary to provide a mechanism for passing the residual toner below the discharge holes 9a and 9b.

【0039】

The transport path forming portion 3 is in a state of forming a part of the image forming apparatus 1, and one end portion 3a in the axial direction thereof is arranged on the upstream side of the paper transport direction C and is connected to the recovery path forming portion 6. The recovery path forming portion 6 connects the one end portion 3a in the axial direction of the transport path forming portion 3 and the toner tank 11a of the developing means 24a of the first stage image forming station Pa, and bends and extends. The recovery path forming portion 6 is formed in a substantially pipe shape by forming an inner space extending in the extending direction thereof. The recovery path forming portion 6 is made of, for example, plastic.

【0040】

The inner space of the recovery path forming portion 6 is the recovery path 8. The recovery path 8 communicates the discharge hole 9a on one side formed in one end 3a of the transport path forming portion 3 with the toner tank 11a of the developing means 24a of the first stage image forming station Pa. With the transport path forming portion 3 forming a part of the image forming apparatus 1, the other end portion 3b in the axial direction of the transport path forming portion 3 is arranged on the downstream side of the paper transport direction C, and is placed in the disposal container 5. Be connected. The other discharge hole 9b formed at the other end 3b in the axial direction communicates with the inner space of the disposal container 5.

【0041】

The transport means 4 includes a rotary shaft 12, a spiral blade 13, and a rotary drive means 14 for rotationally driving the rotary shaft 12. The spiral blade 13 projects from the outer peripheral portion of the rotating shaft 12, swivels around the outer peripheral portion of the rotating shaft 12, and spirally extends in the direction of the 12 axis of the rotating shaft. The rotation driving means 14 is provided outside the transport path forming portion 3. The rotating shaft 12 and the spiral blade 13 form a so-called screw 15. The rotary shaft 12 is inserted through the transport path forming portion 3 in the axial direction thereof, and the rotary drive means 14 is connected to the other end of the rotary shaft 12 on the downstream side in the paper transport direction C in the axial direction. Bearings that rotatably support the rotating shaft 12 are provided at both ends 3a and 3b of the transport path forming portion 3 in the axial direction. Further, a seal member such as a V ring for preventing residual toner from scattering from the portion of the rotating shaft 12 through which the transport path forming portion 3 is inserted is provided.

【0042】

The spiral blade 13 is formed by a portion 13a on the axial direction one end 3a side from the winding direction switching point P, which is a predetermined position in the transport path, and a portion 13b on the axial direction other end 3b side from the winding direction switching point P. The winding direction is different. Specifically, when the spiral blade 13 provided on the rotating shaft 12 is viewed from one end 3a side in the axial direction and the rotating shaft 12 rotates in one direction D in the circumferential direction, which is clockwise in FIG. 1, the winding is performed. The portion 13a on the axial direction end 3a side from the direction switching point P is provided so as to extend from the winding direction switching point P to the axial end 3a portion side while turning the rotation shaft 12 in the direction opposite to the circumferential direction D. Be done. Further, the portion 13b on the other end portion 3b side in the axial direction from the winding direction switching point P extends from the winding direction switching point P to the other end portion 3b side in the axial direction while rotating the rotating shaft 12 in the direction opposite to the circumferential direction unidirectional D. It is provided as follows. Further, the spiral blade body 13 is formed so as to project from the outer peripheral surface of the rotating shaft 12 to a position close to or in contact with the inner peripheral surface of the transport path forming portion 3.

【0043】

The winding direction switching point P is a position A in which the first insertion hole 10a corresponding to the first stage image forming station Pa of the transport path forming portion 3 is formed, and a second position A corresponding to the second stage image forming station Pb. It is provided at a position between the insertion hole 10b and the position B where the insertion hole 10b is formed. As a result, the residual toner generated in the first stage image forming station Pa can be discharged to one discharge hole 9a, and the other residual toner can be discharged from the other discharge hole 9b.

【0044】

Further, the first insertion hole 10a is formed between the position A where the first insertion hole 10a of the transport path forming portion 3 is formed and the position B where the second insertion hole 10b is formed. It is preferable that the position is closer to the position A. That is, the distance L1 from the winding direction switching point P to the position A where the first insertion hole 10a is formed is shorter than the distance L2 from the winding direction switching point P to the position B where the second insertion hole 10b is formed. It is preferably formed. This makes it difficult for the residual toner generated at the second-stage image forming station Pb to pass through the winding direction switching point P, and the toner generated at the second-stage image forming station Pb is discharged on one side. It is possible to prevent the discharge from the hole 9a. Further, the residual toner generated at the first stage image forming station does not cause the reverse transfer phenomenon, and there is little possibility of color mixing with other toners.

【0045】

The recovery path forming portion 6 extends downward from one end portion 3a in the axial direction of the transport path forming portion 3 and is bent in a U shape, for example, in the first stage image forming station located above the transport path forming portion 3. It extends to the upper position of the toner tank 11a of the developing means 24a. The image forming apparatus 1 is provided with a collecting means 16 for conveying the residual toner discharged from one of the discharging holes 9a through the collecting path 8 and collecting it again in the developing means 24a of the first stage image forming station Pa. .. The collection means 16 is housed in the collection path 8.

【0046】

FIG. 2 is an enlarged cross-sectional view of Section II of FIG. The recovery means 16 is composed of a rotatable coil spring 17 which is a screw body having flexibility and elasticity extending spirally in the recovery path, and a pair of bevel gears 18a and 18b. One of the two bevel gears 18a is provided in the portion 12a of the rotating shaft 12 near the discharge hole 9a. The other bevel gear 18b of the two meshes orthogonally with the one bevel gear 18a and is provided so as to face one of the discharge holes 9a. The other bevel gear 18b is rotatably supported by a bearing (not shown) and is arranged at a position where one discharge hole 9a is not blocked. The other bevel gear 18b is formed in a cylindrical shape, and an insertion hole for inserting in the axial direction is formed. By passing the residual toner through the insertion hole of the other bevel gear 18b and moving from the one discharge hole 9a to the recovery path 8, it is possible to prevent the residual toner from being clogged at one end portion 3a in the axial direction of the transport path.

【0047】

A coil spring 17 is connected to the other bevel gear 18b. The coil spring 17 is rotatably provided as the other bevel gear 18b rotates. The coil spring 17 is inserted in the recovery path in the extension direction. The rotation of the coil spring 17 causes a spiral pumping action, and the residual toner discharged from one of the discharge holes 9a into the recovery path 8 can be moved to a toner tank located higher than the photoconductor drum 22a. Since the coil spring 17 has flexibility, it can be inserted over the entire length in the bent recovery path.

【0048】

With the above configuration, the residual toner generated at each image forming station Pa to Pd can be divided into two and discharged to the respective discharge holes 9a and 9b, and the residual toner discharged from one of the discharge holes 9a can be reused. can do.

【0049】

Residual toner generated on each of the photoconductor drums 22a to 22d at each image forming station Pa to Pd is removed by each cleaning means 26a to 26d. The residual toner removed by the cleaning means 26a to 26d passes through the insertion holes 10a to 10d provided for each of the image forming stations Pa to Pd and is housed in the transport path 7 in the common transport path forming portion 3. Will be done. The residual toner transported in the transport path 7 is scraped off by the rotation of the screw 15 and is transported in the axial direction of the transport path forming portion 3.

【0050】

The residual toner generated by the first-stage image forming apparatus Pa is housed in a portion closer to one end in the axial direction of the transport path forming portion 3 than the winding direction switching point P, and is directed toward one end in the axial direction of the transport path forming portion 3. Is transported, and is accommodated in the recovery path 8 through one of the discharge holes 9a. The residual toner generated by the second to fourth stage image forming apparatus Pa is housed in a portion closer to the other end of the transport path forming portion 3 in the axial direction than the winding direction switching point P, and is stored in the axial direction of the transport path forming portion 3. It is transported toward the other end and is accommodated in the disposal container 5 through the other discharge hole 9a.

【0051】

The residual toner contained in the recovery path 8 is conveyed in the recovery path 8 toward the toner tank 11a of the developing means 24a by the rotation of the coil spring 17. The residual toner stored in the toner tank 11a is used again for image formation.

【0052】

According to one embodiment of the present invention as described above, the residual toner generated at the first stage image forming station Pa can be collected and reused without color mixing, and a plurality of transport paths and a plurality of transport paths and The image forming apparatus can be realized with a simple configuration without the need for a conveying means. Specifically, by using one screw 15 having a different winding direction, the number of the transport path 7 and the screw 15 can be reduced, and the size of the apparatus can be reduced. Further, by reducing the number of screws 15, the number of sealing members such as bearings and V-rings and the number of drive sources can be reduced. By reducing the number of parts, the parts cost and the assembly cost can be reduced.

【0053】

Since the residual toner generated at the first-stage image forming station Pa is separated from the other residual toner and discharged from one of the discharge holes 9a, the residual toner can be easily treated. For example, by separating one type of toner that should not be mixed with other toners, the treatment of residual toner can be easily performed. Further, the toner discharged from one of the discharge holes 9a is less likely to be mixed with other toner, and therefore can be suitably used as a reusable toner.

【0054】

Further, in the image forming apparatus 1, the collecting means 16 can collect the residual toner discharged from one of the discharge holes 9a and store it in the toner tank 11a. By connecting the transport path 7 and the toner tank 11a so that the toner can be moved by the recovery path 6, the operator can save the trouble of manually collecting the residual toner, and when the residual toner is stored in the toner tank 11a, the toner is released. The risk of scattering can be eliminated.

【0055】

Further, the screw 15 composed of the rotating shaft 12 and the spiral blade 13 extends over the entire length of the transport path forming portion 3, and the coil spring 17 extends over the entire length of the recovery path forming portion 6. By rotating the screw 15 and the coil spring 17, the toner is transferred while being agitated in the transfer path and the recovery path. Since the toner is conveyed while being agitated, it is possible to prevent the toner from aggregating and solidifying in the conveying path and the collecting path.

【0056】

The color of the toner used by the first-stage image forming station Pa to form the toner image is preferably an achromatic color having low lightness such as black. When the toners of the image forming stations Pb to Pd after the first stage image forming station flow back through the transport path 7 and are mixed with the black toner of the first stage image forming station Pa by using the black toner. Even so, the influence of color mixing due to the mixing of other toners can be reduced, and the quality of the image obtained when the residual toner is reused can be prevented from deteriorating. Further, since the black toner consumes a higher amount of toner than other toners, it is possible to reduce the unevenness of the remaining amount of toner by reusing the black toner.

【0057】

The toner used by the second-stage image forming station Pb to form the toner image may be any color toner, but preferably yellow or the like even if the color is arranged with the first-stage image forming station Pa. Toner of a color with low visibility of the color scheme is used. As a result, in the transport path 7, the residual toner generated at the second-stage image forming station Pb, which has the highest probability of being mixed with the residual toner generated at the first-stage image forming station Pa, flows back in the transport direction and is mixed with the black toner. Even in this case, the influence of color mixing due to the mixing of toner in the second-stage image forming station Pb can be reduced, and the quality of the image obtained when the residual toner is reused can be prevented from deteriorating.

【0058】

Further, the spiral blade body 13 is provided close to or in contact with the inner peripheral surface of the transport path forming portion. The transport path 7 is partitioned by the spiral blade body 13 to prevent the toner in the transport path 7 from easily moving in the axial direction of the transport path forming portion. This makes it difficult for the residual toner to flow back in the transport direction, and it is possible to prevent the separated residual toner from being mixed. Further, for example, the screw 15 can be easily inserted by forming the transport path 7 forming portion into a single cylindrical shape whose inner circumference is substantially uniform in the axial direction. For example, the screw 15 can be easily inserted into the transport path 7 by opening the axial end 3b of the transport path forming portion 3 to insert the screw 15 and then closing the axial end 3b. it can. Further, by sealing both ends of the transport path forming portion 3 in the axial direction, the insertion holes 10a, 10b, 10c, 10d and the discharge holes 9a, 9b, it is necessary to prevent the toner from scattering from the transport path forming portion 3 to the outside. Can be done. Further, since one rotating shaft 12 is inserted through one transport path forming portion 3, there is a smaller gap for inserting the transport path forming portion 3 in the thickness direction as compared with the case where there are a plurality of transport path forming portions 3 and rotating shafts 12. , The possibility of toner leakage in the transport path forming portion 3 can be reduced.

【0059】

FIG. 3 is a cross-sectional view showing a simplified configuration of a main configuration of a digital color copier 500 showing an embodiment of the present invention. For example, the digital color copying machine 500, which is an image forming apparatus, has the configuration of one embodiment of the present invention shown in FIGS. 1 and 2. The digital color copier (hereinafter referred to as a copier 500) has a copier main body 502 and a double-sided automatic document feeder (Reversing Automatic Document Feeder: abbreviated as RAD) 112 provided above the copier main body 502. The copier main body 502 has a platen 111 formed on the upper portion thereof, and an operation panel is provided so as to face the outside of the copier main body 502. Further, the copying machine main body 502 includes an image reading unit 110, an image forming unit 210, a paper feeding mechanism unit 211, and a transfer transfer belt mechanism unit 213 inside the copying machine main body 502.

【0060】

The double-sided automatic document feeding mechanism unit 112 is supported in a state where it can be opened and closed with respect to the document table 111, and has a predetermined positional relationship with respect to the upper surface of the document table 111. The double-sided automatic document feed mechanism unit 112 is provided so as to be able to convey the document arranged at the insertion position on the upper portion or the side portion thereof.

【0061】

The double-sided automatic document feed mechanism unit 112 conveys the document placed at the insertion position, faces one side in the thickness direction of the document toward the document reading unit 110, and brings the document into contact with a predetermined reading position on the upper surface 111a of the platen. Arrange as follows. Further, the double-sided automatic document feed mechanism unit 112 reverses the document placed at the scanning position, then faces the other side in the thickness direction to the document reading unit 110, and brings the document into contact with a predetermined scanning position on the upper surface 111a of the platen. Arrange as follows. Further, the double-sided automatic document feed mechanism unit 112 conveys the document arranged at the reading position to the ejection position. The double-sided automatic document feed mechanism unit 112 is provided so as to be able to execute each of the above-mentioned transport operations in response to a command given from a control unit that controls the entire copying machine 500. The control unit gives each command to the double-sided automatic document feed mechanism unit 112 in relation to the operation of the entire copying machine 500.

【0062】

A flat plate 111b made of translucent glass or the like is formed on the upper part of the platen 111, and the image reading unit 110 is installed below the flat plate 111b. The image reading unit 110 reads an image formed on the document conveyed to the reading position. The image reading unit 110 includes two document scanning bodies 113 and 114 that move in parallel with the flat plate 111b of the platen, an optical lens 115, and a coupled charge element (Charge Coupled Device) line sensor 116 that is an optical conversion element. Have.

【0063】

The first document scanning body 113, which is one of the two, scans the irradiation lamp 113a that irradiates the surface of the document image with light and the second document scanning the reflected light image formed by the reflected light from the document irradiated with the light. It has a first mirror 113b that reflects toward the body 114, and reciprocates in parallel with the flat plate 111b at a predetermined scanning speed while maintaining a constant distance from the flat plate 111b.

【0064】

The second document scanning body 114, which is the other of the two, has second and third mirrors 114a, 114b that reflect the reflected light image reflected from the first mirror 113b toward the optical lens 115. , Maintaining a predetermined positional relationship with the first document scanning body 113, reciprocates in parallel with the flat plate 111b. The optical lens 115 reduces the reflected light image and forms the reflected light image at a predetermined position on the CCD line sensor 116.

【0065】

The CCD line sensor 116 receives the imaged reflected light image, reads a black-and-white image or a color image, and outputs three line data color-separated into red, blue, and green color components as an electric signal. The CCD line sensor 116 gives manuscript image information, which is three line data converted into electrical signals, to an image processing unit (not shown), and the image processing unit processes the image information according to a predetermined algorithm.

【0066】

The image forming unit 210 is provided below the image reading unit 110. Further, the transfer transfer belt mechanism unit 213 is provided so as to face the image forming unit 210. The paper feed mechanism unit 211 separates the originals one by one from the paper tray 400 in which the originals are stored, and conveys the originals toward the image forming unit 210 by the paper feed roller 401. The timing at which the document is conveyed is controlled by a pair of resist rollers 212 arranged in front of the image forming section 210, that is, on the upstream side in the document conveying direction, and the document is conveyed to the image forming section 210. When image formation is performed on both sides, after the image is formed on one side in the thickness direction, the paper is inverted, the timing is controlled by a pair of resist rollers 212, and the image is formed on the other side in the thickness direction of the paper. Will be done.

【0067】

The transfer transfer belt mechanism unit 213 conveys the document along the image forming unit 210, and has a drive roller 214, a driven roller 215, and a transfer transfer belt 216. The transfer transfer belt 216 is formed in an endless annular shape and is arranged so as to face the image forming portion 210. The inner peripheral surface of the transfer transfer belt 216 is stretched in contact with the outer peripheral surfaces of the drive roller 214 and the driven roller 215. The transfer transfer belt 216 electrostatically attracts the document and moves it along the image forming unit 210. Further, the pattern image detection sensor 232 is provided at a position away from the image forming portion 210 of the transfer transfer belt 216, for example, near the lower outer peripheral surface.

【0068】

The copier 500 transports the transfer transfer belt mechanism unit 213 downstream of the transfer transfer belt mechanism unit 213 in order to form a fixing means 217 for fixing the toner image transferred and formed on the document and images on both sides in the thickness direction of the document. It has a transport direction switching body 404 that switches the direction. The fixing means 217 has a pair of fixing rollers 402, and heats and pressurizes the document passing through the nip portion 403 between the pair of fixing rollers 402 to fix the toner to the document.

【0069】

The transport direction switching body 404 is provided on the downstream side of the fixing means 217 in the paper transport direction in a state where the image forming apparatus is formed. The transport direction switching body 404 is formed in a substantially triangular plate shape in which the upper end surface and the lower end surface approach each other and taper toward the paper transport direction, and the corners are around the angular displacement axis extending parallel to the axial direction of the fixing roller 402. Displace. When the transport direction switching body 404 is angularly displaced toward the downward A1, the document comes into contact with the upper surface of the transport direction switching body 404 and is transported along the upper surface thereof. Further, when the transport direction switching body 404 is angularly displaced toward the upper side A2, the document comes into contact with the lower surface of the transport direction switching body 404 and is transported along the lower surface thereof.

【0070】

The transport direction switching body is provided in the transport direction switching gate 218 at 404, and by angular displacement, the document is guided to one of the bifurcated document transport paths, and the document after the transport path is fixed is placed in the discharge tray 220. The transport path for discharging and the transport path for transporting to the image forming unit 210 again are selectively switched. The surface of the document that is re-conveyed to the image forming unit 210 by the transport direction switching body 404 is inverted by the switchback transport path 221 and is re-conveyed to the image forming unit 210.

【0071】

In the image forming unit 210, the first-stage image forming station Pa, the second-stage image forming station Pb, the third-stage image forming station Pc, and the fourth-stage image forming station Pd convey paper in parallel with the transfer transfer belt 216. It is installed side by side from the upstream side in the direction. The transfer transfer belt 216 stretched between the drive roller 214 and the driven roller 215 is frictionally driven by the drive roller 214 and is driven around the drive roller 214 and the driven roller 215, that is, in the direction Z indicated by the arrow Z in FIG. To rotate.

【0072】

The drive roller 214 is arranged closer to the fixing means 217 than the fourth-stage image forming station Pd, and the driven roller 215 is arranged closer to the paper feed mechanism portion 211 than the first-stage image forming station Pa. The axes of the drive roller 214 and the driven roller 215 extend parallel to each other. The transfer transfer belt 216 attracts the originals transported from the paper feed mechanism unit 211 by electrostatically attracting the originals, and sequentially conveys the originals from the first-stage image forming station Pa to the fourth-stage image forming station Pd.

【0073】

Each image forming station Pa to Pd has the same configuration, and includes photoconductor drums 222a to 222d, chargers 223a to 223d, developing means 224a to 224d, transfer dischargers 225a to 225d, cleaning means 226a to 226d, and exposure. It has laser beam scanner units 227a to 227d as means, respectively.

【0074】

Each of the photoconductor drums 222a to 222d is provided in close proximity to or in contact with the transfer transfer belt 213, and has an axis parallel to the axes of the driving roller 214 and the driven roller 215. The photoconductor drums 222a to 222d are rotationally driven by a driving means (not shown) so that the peripheral speeds are the same in the direction F following the rotation direction Z of the transfer transfer belt 213. Around the outer circumference of each photoconductor drum 222a to 222d, each charger 223a to 223d and each photoconductor drum 222a to 222d are arranged in order in the photoconductor drum rotation direction F to uniformly charge each photoconductor drum 222a to 222d. Each developing means 224a to 224d that develops the electrostatic latent image formed above, and a transfer discharger 225a ~ that is a transfer means that transfers the toner image on each developed photoconductor drum 222a to 222d to a document, respectively. Cleaning means 226a to 226d for removing the toner remaining on the 225d and each of the photoconductor drums 222a to 222d are arranged.

【0075】

Each laser beam scanner unit 227a to 227d irradiates the outer peripheral surface of the photoconductor drum between the chargers 223a to 223d and the developing means 224a to 224d with laser light, and for example, above the respective photoconductor drums 222a to 222d. Be placed.

【0076】

Each laser beam scanner unit 227a to 227d includes a semiconductor laser element (not shown) that emits dot light modulated according to the image to be formed, and polygon mirrors 240a to 240a for deflecting the laser light from the semiconductor laser element in the main scanning direction. Each of the 240d has an fθ lens for forming a laser beam deflected by the polygon mirrors 240a to 240d, which are deflection means, on the surface of the photoconductor drums 222a to 222d, and a plurality of mirrors for changing the reflection direction.

【0077】

Each of the laser beam scanner units 227a to 227d partially irradiates the outer peripheral surface of the photoconductor with a laser beam according to the image to be formed. In the photoconductor drums 222a to 222d irradiated with the laser beam, the electric charge of the portion irradiated with the laser is reduced, a potential difference is generated between the portion not irradiated with the laser, and an electrostatic latent image is formed on the outer peripheral surface.

【0078】

The developing means 224a to 224d positively charge the toner and attach the toner to the photoconductor drum. The toner adheres to the portion of the photoconductor drums 222a to 222d that has not been irradiated with the laser, and the electrostatic latent image is developed as a toner image.

【0079】

The laser beam scanner unit 227a of the first-stage image forming station Pa receives a pixel signal corresponding to the black component image of the color document and irradiates the photoconductor drum 222a with the laser light corresponding to the black component image. The laser beam scanner unit 227b of the second-stage image forming station Pb receives a pixel signal corresponding to the yellow component image of the color document, and irradiates the photoconductor drum 222b with the laser light corresponding to the yellow component image. The laser beam scanner unit 227c of the third-stage image forming station Pc receives a pixel signal corresponding to the cyan component image of the color document, and irradiates the photoconductor drum 222c with the laser beam corresponding to the cyan component image. The laser beam scanner unit 227d of the fourth-stage image forming station Pd receives a pixel signal corresponding to the magenta component image of the color document, and irradiates the photoconductor drum 222d with the laser beam corresponding to the magenta component image.

【0080】

An electrostatic latent image corresponding to the color-converted original image information is formed on each of the photoconductor drums 222a to 222d. The developing means 224a to 224d contain toners of colors corresponding to the respective laser beam scanner units 227a to 227d, and the developing means 224a of the first-stage image forming station Pa contains black toner and second. The developing means 224b of the stage image forming station Pb contains yellow toner, and the developing means 224c of the third stage image forming station Pc contains cyan color toner, and the developing means of the fourth stage image forming station Pd. The 224d contains magenta toner. The electrostatic latent images on the photoconductor drums 222a to 222d are developed by the toners of each of these colors, and the converted original image information is reproduced as the toner images of each color by the image forming unit 210.

【0081】

The digital color copier 500 uses cut sheet-like paper for the original, and the paper is fed out from the paper feed cassette and supplied into the guide of the paper feed transfer path of the paper feed mechanism 211. The tip of the supplied document is detected by a sensor (not shown), and the document stops at the positions of the pair of resist rollers 212 based on the detection signal output from this sensor. The original is sent onto the transfer transfer belt 216 rotating in one direction Z at the same timing as each image forming station Pa to Pd.

【0082】

The transfer transfer belt 216 is charged by a paper suction charger 228 provided between the first stage image forming station Pa and the paper feeding mechanism unit . Therefore, the originals supplied from the paper feed mechanism unit 211 are conveyed without shifting between the first-stage image forming station Pa and the fourth-stage image forming station Pd in a state where they are securely adsorbed on the transfer transfer belt 216. Will be done. Since toner images of each color are formed in the image forming stations Pa to Pd, the toner images are superimposed on the original surface of the original document which is electrostatically adsorbed and conveyed by the transfer transfer belt 216.

【0083】

When the transfer of the image by the fourth-stage image forming station Pd is completed, the original is separated from the transfer transfer belt 216 by the static elimination discharger 229. The separated document is conveyed to the fixing means 217. A document to which toner has been fixed by 217 by the fixing means is ejected to the output tray 220 through an original ejection hole (not shown).

【0084】

In the above description, the laser beam scanner units 227a to 227d scan the laser beam to expose the photoconductor drums 222a to 222d to form an electrostatic latent image. As another configuration for forming an electrostatic latent image, an exposure means called an LED head including a light emitting diode array and an imaging lens array may be used instead of the laser beam scanner units 227a to 227d. The size of the LED head can be reduced as compared with the laser beam scanner unit. Moreover, since the LED head has no moving part, noise can be reduced. Therefore, a plurality of image forming stations are required, and it can be suitably used for a tandem type image forming apparatus that becomes large in size.

【0085】

A pattern image detection sensor 232 is provided on the outer peripheral surface of the transfer transfer belt 216 on the opposite side of the image forming portion 210. The pattern image detection sensor 232 measures the density of the patch image for image adjustment formed by transfer on the transfer transfer belt 216. The image forming unit 210 is provided with the environment sensor 233. Environmental conditions can be detected by the environmental sensor 233. Based on the information obtained by the pattern image detection sensor 232 and the environment sensor 233 in this way, the grid bias voltage of each charger 223a to 223d, the development bias voltage of each developing means 224a to 224d, and each transfer discharger 225a ~ Good image formation can be performed by adjusting the transfer bias voltage of the 225d, the output voltage of the laser beam scanner units 227a to 227d, the halftone table of the image processing unit that performs image processing, and the like.

【0086】

The environment sensor 233 detects the temperature and humidity in the apparatus and is provided at a position where the influence of sudden temperature and humidity changes is small, for example, in the vicinity of the image forming unit 210. Two detection rollers 231 having an axis parallel to the drive roller shaft are provided inside the transfer transfer belt 216, and the detection rollers 231 come into contact with the transfer transfer belt 216 and extrude the transfer transfer belt 216 outward to form a pattern. The distance between the image detection sensor 232 and the transfer transfer belt 216 can be kept constant. Furthermore, by setting conditions according to predetermined reference values such as when energized, the elapse of a predetermined time after energization, the number of images formed, and the usage time of replaceable consumable parts, an even more optimal image is obtained when the conditions are met. Adjustments can be made.

【0087】

Further, a belt cleaning means 241 for removing toner adhering to the outer peripheral surface of the transfer transfer belt 216 is formed on the outer peripheral surface of the transfer transfer belt 216 opposite to the image forming portion 210, and the belt cleaning means 241 is a cleaning member 240. Abuts on the outer peripheral surface of the transfer transfer belt 216 to peel the toner from the transfer transfer belt 216.

【0088】

Further, in the configuration of the copying machine 500 described above, the density of the patch image is detected after the patch image is transferred to the transfer transfer belt 216, but the patch image is not transferred to the transfer transfer belt 216 but is transferred on the photoconductor drum. The density of the patch image may be detected to detect the data for adjusting the image quality. In this case, after the density measurement, the cleaning means 226a to 226d removes the residual toner on the photoconductor drums 222a to 222d.

【0089】

Further, the copying machine 500 has the configuration shown in FIG. 1, and has a transport path forming portion 3, a transport means 4, a disposal container 5, and a recovery path forming section 6. In FIG. 3, the outer line including the transport path forming section 3, the disposal container 5, and the recovery path forming section 6 is shown by a two-dot chain line.

【0090】

These configurations are provided in the same manner as the configurations shown in FIG. 1, and the same effects as described above can be obtained. The copying apparatus 500 needs to read an image, form an image, and convey paper. Therefore, the configuration becomes complicated, and when a configuration in which the residual toner can be reused is provided, a configuration having a simple structure and a small number of parts is desired. According to the present invention, a copying machine 500 capable of reusing residual toner can be preferably realized. Specifically, the residual toner generated in the first-stage image forming station can be reused by a simple configuration, which is a simpler configuration than the second conventional image forming apparatus described above, and the number of component parts. Can be reduced and miniaturized. Further, by reducing the number of parts, the parts cost and the assembly cost can be reduced.

【0091】

FIG. 4 is a cross-sectional view showing a simplified main configuration of a digital color copier 600 showing another embodiment of the present invention. A digital color copier 600 that employs, for example, an intermediate transfer method has a configuration of one embodiment of the present invention shown in FIG. The digital color copier (hereinafter referred to as the copier 600) that employs the intermediate transfer method has almost the same configuration as the copier 500 shown in FIG. 3, and the same components are designated by the same reference numerals and the description thereof is omitted. To do. In the intermediate transfer method, the toner images of each color formed by the image forming stations Pa to Pd are sequentially superimposed and transferred on the intermediate transfer belt 216A, and all the toner images are superimposed on the intermediate transfer belt 216A. The toner image transferred to the intermediate transfer belt 216A is transferred onto the document supplied from the paper feed mechanism unit 211 as it passes between the pair of secondary transfer rollers 243 facing each other.

【0092】

Such an intermediate transfer type copying machine also has the configuration shown in FIG. 1, and has a transport path forming section 3, a transport means 4, a disposal container 5, and a recovery path forming section 6. In FIG. 4, the outer line including the transport path forming section 3, the disposal container 5, and the recovery path forming section 6 is shown by a two-dot chain line. These configurations in FIG. 4 are provided in the same manner as the configurations shown in FIG. 1, and the same effects as described above can be obtained. The copying apparatus 600 needs to read an image, form an image, and transport a document. Therefore, the configuration becomes complicated. Therefore, when a configuration in which the residual toner can be reused is provided, a configuration having a simple structure and a small number of parts is desired. According to the present invention, a copying machine 600 capable of reusing residual toner can be preferably realized. Specifically, the residual toner generated in the first-stage image forming station can be reused by a simple configuration, which is a simpler configuration than the second conventional image forming apparatus described above, and the number of component parts. Can be reduced and miniaturized. Further, by reducing the number of parts, the parts cost and the assembly cost can be reduced.

【0093】

Further, the transport path 7, the recovery path 8, and the disposal container 5 are arranged at positions away from the fixing means 217. By providing the transport path 7, the recovery path 8, and the disposal container 5 at positions away from the fixing means 217 that serves as a heat source, the residual toner to be transported is prevented from solidifying and the residual toner is smoothly transported. can do.

【0094】

The above description is an example of the practice of the present invention, and the configuration can be changed within the scope of the invention. For example, the toner for which each image forming station Pa to Pd forms a toner image may be either a one-component toner or a two-component toner, and may not be black, yellow, cyan, or magenta, and the number of image forming stations is four. It does not have to be, and it may be two or more. Further, the image forming apparatus is supposed to form an image on a document as a recording material, but it does not have to be paper, and may be, for example, a transparent resin sheet or the like. Further, by providing a partition plate for partitioning the transport path 7 at the winding direction switching point P portion of the rotating shaft 12, it is possible to more reliably prevent toner from entering. Further, the transport path 7 may be inclined so that its axis is positioned upward toward one end 3a, and the residual toner generated at the 2nd to 4th stage image forming stations Pb to Pd is discharged from one side. It is possible to make it difficult to move to the hole 9a and prevent the residual toner generated at the first stage image forming station Pa from being mixed.

【0095】

[Effect of the invention]

As described above, according to the present invention, it is not necessary to provide a transport path and a transport means for each image forming station, and the waste developer generated from each image forming station is transported by a common transport means to the two discharge holes. It can be discharged separately. By providing a common transport means and transport path, the number of parts can be reduced, the configuration can be simplified, and the parts cost and the assembly cost can be reduced.

【0096】

Further, the image forming apparatus can easily store the waste developing agent discharged from each discharge hole, and can easily process the stored waste developing agent. Further, by standardizing the transport means and the transport path and reducing the number of the transport means and the transport path, it is possible to reduce the area occupied by the transport means and the transport path forming portion in the image forming apparatus and to reduce the size of the image forming apparatus. it can.

【0097】

Further, according to the present invention, by rotating the spiral blade, the waste developing agent guided to the transport path can be divided into two and transported to the discharge hole, and the waste developing agent in the transport path is transported. The means can be suitably realized. For example, the spiral blade serves as a partition for partitioning the inside of the transport path, so that the waste developing agent can be prevented from flowing back toward the predetermined position. Further, the transport path only needs to be formed with a region for accommodating the rotating body and the spiral blade that are inserted into the transport path, and the rotation drive mechanism can be provided outside the transport path, so that the transport path becomes large. Can be prevented.

【0098】

Further, according to the present invention, it is possible to prevent other developing agents from being mixed with the waste developing agent generated in the first stage image forming station and to convey the waste developing agent to the discharge hole at one end of the transport path forming portion. .. As a result, the waste developing agent generated from the first stage image forming station can be discharged from the discharge hole. As a result, the waste developing agent recovered from each discharge hole can be easily processed.

【0099】

Further, according to the present invention, the first-stage image forming station forms a developer image with an achromatic developer, and the waste developer generated at the first-stage image forming station is mixed in the transport path. , The influence of color change due to color mixing can be reduced. As a result, the waste developer generated at the first-stage image forming station and discharged from the discharge hole at one end of the transport path forming portion can be reused as the developing agent used for image forming again. As a result, the developer can be effectively used, the amount of the developer that is wasted can be reduced, and the number of images formed in the recording agent that is formed per unit amount of the developer can be increased. In particular, the first-stage image forming station uses a black developer to form a black developer image, and the black developer is reused, so that the consumption of the black developer is larger than that of other colors. It is possible to reduce the bias between the remaining amount and the remaining amount of other developing agents.

【0100】

Further, according to the present invention, the waste developing agent can be collected by the collecting means and stored in the first stage image forming station again, so that the waste developing agent can be reused. As a result, it is possible to reduce wasteful consumption of the developer and increase the number of images that can be formed on the recording material per unit amount of the developer. Further, it is not necessary for the operator to perform the collection work of accommodating the waste developer in the first stage image forming station, and the convenience can be improved.

【0101】

Further, according to the present invention, the second-stage image forming station forms a developer image with a developer having a color scheme that is less visible than the color of the developer of the first-stage image forming station. As a result, when the waste developer generated at the first-stage image forming station is mixed in the transport path, the influence of the color change due to the color mixing can be reduced, and the waste developer is generated at the first-stage image forming station and is generated at the transport path. The waste developer discharged from the discharge hole at one end of the forming portion can be reused as a developing agent used for image formation. As a result, the developer can be effectively used, the amount of the developer that is wasted is reduced, and the developer image formed in the unit developer amount can be increased.

【0102】

Further, according to the present invention, since a predetermined position in the transport path is provided near the position where the waste developing agent is guided from the first stage image forming station, the waste developing agent generated from the first stage image forming station can be used in addition to the waste developing agent. It is possible to prevent the developer from being mixed in and to carry the developer to the discharge hole at one end of the transport path forming portion. As a result, it is possible to obtain a waste developing agent generated at the first stage image forming station, which is not mixed with other developing agents. As a result, the waste developing agent discharged from the discharge hole can be easily treated.

【0103】

Further, according to the present invention, each image forming station has an image carrier, a developing means, a transferring means, and a cleaning means, and each image has each configuration according to claims 1 to 7. Recovery or reuse of the waste developer generated at the forming station can be preferably realized.

[Simple explanation of drawings]

[Figure 1]

It is sectional drawing which shows the main structure of the image forming apparatus 1 of one Embodiment of this invention simplified.

[Figure 2]

FIG. 5 is an enlarged sectional view showing Section II of FIG.

[Fig. 3]

It is sectional drawing which shows the main structure of the digital color copying machine 500 which shows the Example of this invention in a simplified manner.

[Fig. 4]

It is sectional drawing which shows the main structure of the digital color copying machine 600 which shows the other Example of this invention in a simplified manner.

[Explanation of symbols]

1 Image forming device 3 Transport path forming part 3a Transport path forming part One end in the axial direction 3b Transport path forming part Axial direction other end 4 Transport means 5 Disposal container 6 Recovery path formation part 7 Transport path 8 Recovery route 9a, 9b cloaca 10a, 10b, 10c, 10d insertion holes 12 axis of rotation 13 Spiral wing 14 Rotational drive means 15 screws 16 Collection means 22a, 22b, 22c, 22d Photoreceptor drum 24a, 24b, 24c, 24d Development means 26a, 26b, 26c, 26d Cleaning means P Winding direction switching point C Paper transport direction Pa Pb Pc Pd image formation station