JP4466159B2 - Image forming apparatus - Google Patents

Description

  The present invention relates to an image forming apparatus having a waste toner storage container for storing waste toner.

  A toner image carrier that carries a toner image, such as a photosensitive drum or a transfer belt, is provided with a waste toner storage container that removes toner remaining after transfer and stores waste toner. Such a waste toner container is usually detachably attached to the main body of the apparatus and often has a flat box shape.

Conventionally, various proposals have been made to efficiently store waste toner in the waste toner container having the above-described configuration. For example, in Patent Document 1, a waste toner inlet is provided at the center of the short side of a flat box-shaped waste toner box, an impact is applied from the side surface near the center of the short side on the opposite side, and the waste toner box is moved in the long side direction. Vibrate. By this driving force, waste toner accommodated near the entrance of the waste toner box is sent to the back side of the box, and the waste toner box is collected efficiently by effectively using the capacity of the waste toner box.
JP 2001-296679 A (paragraph numbers 0009 to 0025, FIGS. 1 to 5)

  However, in the above-described conventional apparatus, an impact force is applied to uniformly store the waste toner in the waste toner box having a large area. For this reason, the generation of impact noise is inevitable, and the impact noise naturally increases as the waste toner box becomes larger.

In addition, it is difficult to determine the time interval at which the impact force is applied, and when an impact force is arbitrarily applied, a device such as a solenoid including a control circuit is required.
Therefore, the present invention does not apply an impact force to the waste toner box (waste toner collection container), but evenly smoothes the waste toner by the belt-like circulation member provided with the leveling portion, thereby improving the waste toner accommodation rate. Is.

According to the present invention, there is provided a cleaner for removing waste toner carried on a belt-like toner image carrier that circulates and a waste toner carrying means for carrying the waste toner removed by the cleaner , A thin flat box-shaped waste toner storage container which is provided to store the waste toner transported by the waste toner transport means and is detachable from the apparatus main body along the belt surface of the belt-shaped toner image carrier. In the image forming apparatus, the waste toner container has a receiving port for receiving the waste toner transported by the waste toner transport unit at one corner of one side of the top surface of the container, and a pair along the side direction of the one side. of behenate belt-like circulation member passed to the circulating movement in the horizontal direction over the rotating shaft and furnished to the vessel upwardly, the outer peripheral surface of the belt-like circulation member, the rotary shaft at a predetermined angle A convex part formed along the intersecting direction, and a leveling part that averages waste toner that is received and accumulated through the receiving port as the belt-shaped circulation member moves away from the receiving port. This can be achieved by providing an image forming apparatus characterized by comprising:

  With this configuration, the waste toner stored in the waste toner collection container is stacked in the container, and is sent from the upper part to the side of the waste toner collection container while being leveled by the leveling unit. It is transported uniformly along the moving direction of the circulation member, and waste toner can be uniformly stored in a so-called lunch box-like thin container. Further, it is possible to improve the waste toner accommodation rate without generating the noise associated with the impact force as in the prior art.

  Moreover, the said leveling part is comprised by the convex part formed in the said belt-shaped circulation member, for example with a predetermined angle. With this configuration, waste toner can be efficiently conveyed with a simple belt structure.

  According to the present invention, the waste toner is uniformly conveyed into the waste toner collection container by the leveling portion formed on the belt-like circulation member. For example, even in a thin lunch box-like waste toner collection container, the waste toner storage rate is increased. Can be improved.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a cross-sectional view illustrating an internal configuration of an image forming apparatus (hereinafter referred to as a printer) 1 according to an embodiment of the present invention. The printer 1 shown in FIG. 1 is an electrophotographic tandem color image forming apparatus, and includes four image forming units 2, an intermediate transfer belt unit 3, a paper feeding unit 4, and a duplex printing transport unit 5. ing.

  The four image forming units 2 have a configuration in which four image forming units 6 (6M, 6C, 6Y, 6K) are arranged side by side in a multistage manner from right to left in FIG. Of the four image forming units 6, three image forming units 6M, 6C, and 6Y on the upstream side (right side in the figure) are magenta (M), cyan (C), yellow (subtractive three primary colors), respectively. A mono-color image is formed with the color toner of Y), and the image forming unit 6K forms a monochrome image with black (K) toner mainly used for dark portions of characters and images.

  Each of the image forming units 6 has the same configuration except for the color of the toner stored in the toner container. Accordingly, the configuration of the black (K) image forming unit 6K will be described below as an example.

  The image forming unit 6 includes a photosensitive drum 7 at the bottom. The peripheral surface of the photosensitive drum 7 is made of, for example, an organic photoconductive material. A cleaner 8, a charger 9, an optical writing head 11, and a developing roller 13 of a developing device 12 are arranged around the periphery of the photosensitive drum 7. The optical writing head 11 has a separate structure from the image forming unit 6. Further, the image forming unit 6 is configured to be able to be inserted and removed in the drawing depth direction by opening a front door (not shown) in front of the printer 1 (front side of the drawing).

  The developing device 12 puts one of magenta (M), cyan (C), yellow (Y), and black (K) toners in the upper toner container as indicated by M, C, Y, and K in the drawing. The intermediate portion is provided with a toner replenishing mechanism for the lower portion, the lower portion is provided with the above-described developing roller 13 at the side opening, the toner stirring member inside, the toner supply roller for supplying toner to the developing roller 13, and the developing A doctor blade or the like for regulating the toner layer on the roller 13 to a constant layer thickness is provided.

  The intermediate transfer belt unit 3 includes a transfer belt 14 that extends in a substantially loop shape from substantially the left and right sides of the drawing at the center of the main body, and the transfer belt 14 that is stretched over the transfer belt 14. A driving roller 15 and a driven roller 16 that circulate in the counterclockwise direction in the figure are provided.

  The transfer belt 14 directly transfers the toner image onto the belt surface (primary transfer), and conveys the toner image to a transfer position on the paper for further transfer (secondary transfer) onto the paper. In this example, the entire unit is described as an intermediate transfer belt unit.

  The intermediate transfer belt unit 3 includes a belt position control mechanism 17 in the loop of the flat loop-shaped transfer belt 14. The belt position control mechanism 17 includes a primary transfer roller 18 made of a conductive foam sponge that presses against the lower peripheral surface of the photosensitive drum 7 via the transfer belt 14.

  The belt position control mechanism 17 has three primary transfer rollers 18 corresponding to the three image forming units 6M, 6C, and 6Y of magenta (M), cyan (C), and yellow (Y) as vertical support shafts. The image is transferred to the center at the same cycle, and the one primary transfer roller 18 corresponding to the black (K) image forming unit 6K is rotated at a rotation cycle different from the cycle of the three primary transfer rollers 18 for transfer. The belt 14 is moved away from the photosensitive drum 7, and the full color mode (all four primary transfer rollers 18 are in contact with the transfer belt 14) and the monochrome mode (only the primary transfer roller 18 corresponding to the image forming unit 6K is the transfer belt). 14) and all non-transfer mode (all four primary transfer rollers 18 are separated from the transfer belt 14).

  In the intermediate transfer belt unit 3, a belt cleaner unit 19 is disposed further upstream of the uppermost image forming unit 6 </ b> M in the belt moving direction on the upper surface, and is flat so as to be almost along the entire lower surface. A thin waste toner collecting container 20 is detachably disposed.

  The paper feed unit 4 includes two paper feed cassettes 21 arranged in two upper and lower stages, and in the vicinity of the paper feed opening (right side in the figure) of the two paper feed cassettes 21, respectively, A feeding roller 23, a separating roller 24, and a conveying roller pair 25 are disposed. In the paper conveyance direction (vertical direction in the figure) of the conveyance roller pair 25, a secondary transfer roller 26 that is pressed against the driven roller 16 via the transfer belt 14 is disposed to form a secondary transfer portion to the paper. is doing.

  A belt-type heat fixing device 27 is disposed downstream (upward in the drawing) of the secondary transfer portion, and the sheet after fixing is fixed to the belt-type heat fixing device 27 further downstream of the belt-type heat fixing device 27. A pair of carry-out rollers 28 for carrying out the paper and a pair of paper discharge rollers 31 for discharging the carried paper to a paper discharge tray 29 formed on the upper surface of the apparatus are disposed.

  The duplex printing conveyance unit 5 includes a start return path 32a that branches from the intermediate conveyance path between the carry-out roller pair 28 and the discharge roller pair 31 to the right lateral direction in the drawing, and then an intermediate return path 32b that bends downward. A terminal return path 32c that bends in the left lateral direction opposite to the above and eventually reverses the return sheet, and three return roller pairs 33a, 33b, and 33c arranged in the middle of these return paths are provided. . A pair of carry-in rollers 34 is disposed inside the main body device at the outlet of the end return path 32c.

  In the present example, the belt cleaner unit 19 disposed on the upper surface of the intermediate transfer belt unit 3 includes a lower cleaning roller 35, an upper intake roller 36, and a conveying screw 37 that are disposed in two stages. . The lower cleaning roller 35 comes into contact with the upper surface of the transfer belt 14 to scrape and remove the waste toner, and the take-in roller 36 takes over the waste toner removed by the cleaning roller 35 and accumulates it in the belt cleaner unit 19, and the conveying screw 37 The accumulated waste toner is transported to the upper part of the dropping cylinder 38 and sent to the waste toner collecting container 20 via the dropping cylinder 38.

  In order to bring the cleaning roller 35 into pressure contact with the transfer belt 14 with an appropriate pressure, a pressure roller 39 that presses the transfer belt 14 toward the cleaning roller 35 from below is provided on the intermediate transfer belt unit 3 side. ing.

  2A is a perspective view of the waste toner collecting container 20, and FIG. 2B is a cross-sectional view taken along the line A-A 'of FIG. In FIGS. 2A and 2B, a circular hole formed in the upper surface of the waste toner collecting container 20 is a waste toner inlet 48. FIG. The waste toner removed by the belt cleaner unit 19 falls through the waste toner inlet 48 into the container. The dropping cylinder 38 is located immediately above the waste toner inlet 48, and the waste toner is sent to the waste toner inlet 48 through the dropping cylinder 38 and falls into the waste toner collecting container 20.

  Reference numeral 42 denotes a transport belt, which is circulated and moved in the direction described later by the drive gear 45. The drive gear 45 is connected to, for example, a gear that drives the transfer belt 14 described above, and is driven in accordance with the drive of the transfer belt 14.

  Reference numeral 47 denotes a sensor which detects a marking described later formed on the transport belt 42 and transmits a detection signal to a control unit (not shown). The sensor 47 of this example is a reflection type optical sensor, which irradiates the transport belt 42 with light from the light emitting portion and detects the reflected light to know the presence or absence of marking.

  Note that arrows b and b 'shown in FIG. 5A indicate the attaching and detaching directions when the waste toner collecting container 20 is attached and detached from the image forming apparatus main body. The guide rib 50 provided on the side surface of the waste toner collection container 20 is a guide for mounting the waste toner collection container 20 on the apparatus main body.

  3A and 3B are views for explaining the internal configuration of the waste toner collecting container 20 and the configuration of the transport belt 42. FIG. 3A shows the arrangement of the transport belt 42. FIG. 2B is a view of FIG. 1A viewed from the direction of the arrow c. As shown in FIGS. 4A and 4B, the transport belt 42 is disposed on the entire upper surface of the waste toner collecting container 20 and is circulated and moved in the direction of the arrow d. This circulating movement is performed by rotationally driving the drive shaft 44 according to the rotation of the drive gear 45.

  That is, the transport belt 42 is stretched between the drive shaft 44 and a driven shaft 43 disposed opposite to the drive shaft 44, and moves the transport belt 42 in the direction of the arrow d according to the rotational drive of the drive shaft 44. The lower surface of the transport belt 42, that is, the surface on the side where the waste toner is conveyed moves in the direction of the arrow d '.

  Further, streaky convex portions (ribs) 49 are formed on the surface of the transport belt 42, and streaky convex portions (ribs) 49 are formed at regular intervals throughout the transport belt 42. In FIG. 9A, the solid line is a line-like convex part (rib) 49 on the upper surface side of the transport belt 42, and the line-shaped convex part (rib) when the dotted line is turned to the lower surface side of the transport belt 42. 49 is shown.

  Here, the inclination angle of the line-like convex portions (ribs) 49 is set based on data obtained in a waste toner conveyance experiment or the like performed in advance. The marking 46 provided on the upper portion of the transport belt 42 corresponds to the position where the sensor 47 is disposed, and the transport belt 42 moves in the directions of the arrows d and d 'so that the marking 46 is detected.

FIG. 4 is a view showing a cross-sectional shape of a streaky convex portion (rib) 49 formed on the transport belt 42. In FIG. 5A, the cross-sectional shape of the streaky convex portion (rib) 49 is a quadrangle, and is integrally formed with the belt. Further, in FIG. 5B, the cross-sectional shape of the streaky convex portion (rib) 49 is a U-shape, and is produced by bending a belt. Further, in FIG. 5C, the cross-sectional shape of the streaky convex portion (rib) 49 is a triangle, and is integrally formed with the belt. Further, in FIG. 4D, the cross-sectional shape of the streaky convex portions (ribs) 49 is a triangle, and is produced by bending a belt.
The arrows shown in the figure indicate the direction in which the waste toner is conveyed, and all are formed in a shape that facilitates the conveyance of the waste toner.

In the above configuration, the processing of this example for actually storing waste toner in the waste toner collecting container 20 efficiently will be described.
First, as described above, the image forming units 6M, 6C, 6Y, and 6K are used to transfer a toner image to the transfer belt 14, and further transfer (secondary transfer) the toner image to a sheet. At this time, the toner that has not been completely transferred to the sheet remains on the transfer belt 14, and the residual toner is removed by the belt cleaner unit 19 described above. The waste toner removed by the belt cleaner unit 19 is collected into the waste toner collection container 20 from the waste toner inlet 48 of the waste toner collection container 20 through the dropping cylinder 38 described above.

FIG. 5 and FIG. 6 are diagrams for explaining the transport of waste toner in the waste toner collection container 20. 5 is a front sectional view of the waste toner collecting container 20, and FIG. 6 is a right sectional view of FIG.
First, (a) in both figures shows a state in which waste toner falls through the dropping cylinder 38 and the waste toner inlet 48, and the waste toner is accumulated in the waste toner collecting container 20 immediately below the waste toner inlet 48. FIG. Thereafter, when the waste toner is further accumulated, the mountain state shown in FIG. 7B is reached, and the accumulated waste toner peak reaches the transport belt 32. When this happens, the upper part of the waste toner is carried in the direction of the arrow by the streaky convex portions (ribs) 49 provided on the surface of the transport belt 42. That is, the toner is transported in the direction indicated by the arrow e in FIG. 3A and transported to the side of the waste toner collecting container 20 while leveling the upper part of the accumulated waste toner.

  Thereafter, as shown in FIGS. 5 and 6 (c) → (d) → (e), the waste toner is sequentially carried into the waste toner collecting container 20 and further from the state shown in FIGS. When the waste toner is collected, the above-mentioned marking 46 is covered with the waste toner. For this reason, the sensor 47 cannot detect the marking 46 and knows that the waste toner collecting container 20 is full of waste toner.

  As described above, according to the present embodiment, the waste toner is efficiently carried into the waste toner collecting container 20 by the streaky convex portions (ribs) 49 formed on the transport belt 42, and the waste toner in a thin lunch box shape. Also in the collection container, the waste toner storage rate can be improved.

Further, by marking the belt-like circulation member and detecting the marking with a sensor, it is possible to immediately detect the full state of the waste toner box.
Note that the formation angle of the streaky convex portions (ribs) 49 of the transport belt 42, the shape of the convex portions 49, the number of formed convex portions, the belt speed, and the like are set based on, for example, experimental results and design values performed in advance.

1 is a diagram illustrating an overall configuration of an image forming apparatus according to an exemplary embodiment. (A) is a perspective view of a waste toner collecting container used in the image forming apparatus of the present embodiment, and (b) is a cross-sectional view taken along line A-A ′ of FIG. (A) shows the arrangement | positioning structure of a transport belt, (b) is the figure which looked at the figure (a) from the arrow c direction. (A)-(d) is a figure which shows the cross-sectional shape of the streaky convex part (rib) used by this embodiment. (A)-(e) is a figure which shows the mode of collection of waste toner, and the mode of conveyance of waste toner in a waste toner collection container. (A)-(e) is a figure which shows the mode of collection of waste toner, and the mode of conveyance of waste toner in a waste toner collection container.

Explanation of symbols

1. Image forming apparatus (printer)
DESCRIPTION OF SYMBOLS 2 ... Image formation part 3 ... Intermediate transfer belt unit 4 ... Paper feed part 5 ... Conveyance unit for double-sided printing 6 (6M, 6C, 6Y, 6K) ... Image formation unit 7. Photoconductor drum 8 ... cleaner 9 ... charger 11 ... optical writing head 12 ... developing device 13 ... developing roller 14 ... transfer belt 15 ... driving roller 16 ... -Follower roller 17 ... Belt position control mechanism 18 ... Primary transfer roller 19 ... Belt cleaner unit 20 ... Waste toner collection container 21 ... Paper feed cassette 22 ... Paper take-out roller 23 ...・ Feeding roller 24... Rolling roller 25... Conveying roller pair 26... Secondary transfer roller 27... Belt-type heat fixing device 28. ..Discharge roller pair 32 a ... start return path 32b ... intermediate return path 32c ... end return path 33a, 33b, 33c ... return roller pair 34 ... carry-in roller pair 35 ... cleaning roller 36 ... take-in Roller 37 ... Conveying screw 38 ... Drop cylinder 39 ... Pressing roller 42 ... Transport belt 43 ... Drive shaft 44 ... Drive shaft 45 ... Drive gear 46 ... Marking 47 .... Sensor 48 ... Waste toner inlet 49 ... Projection 50 ... Guide rib

Claims (1)

A cleaner that removes waste toner carried on a belt-like toner image carrier that circulates, a waste toner carrying means that carries the waste toner removed by the cleaner, and a waste toner carrying means that carries the waste toner. An image forming apparatus having a thin flat box-shaped waste toner storage container provided to store the waste toner and detachable from the apparatus main body along a belt surface of the belt-shaped toner image carrier;
The waste toner container has a receiving port for receiving the waste toner conveyed by the waste toner conveying means at one corner of one side of the upper surface of the container, and spans a pair of rotating shafts along the side direction of the one side. are then furnished with behenate belt-like circulation member to circulate horizontally moved to the container upwards,
A convex portion formed on the outer peripheral surface of the belt-shaped circulation member along a direction intersecting the rotation shaft at a predetermined angle, and is received through the receiving port as the belt-shaped circulation member moves. An image forming apparatus comprising a leveling unit for leveling the accumulated waste toner away from the receiving port .

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