JP2004252491A - Process unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a toner amount detecting device from performing erroneous detection even when a waste toner container is slanted after being detached from an image forming device main body of an image forming device equipped with a waste toner storage device which carries waste toner in the waste toner container fed through a toner entrance by a toner carrying screw and detects the waste toner container full of toner by the toner amount detecting device in such a case. <P>SOLUTION: The image forming device is equipped with a shield body 45 between the toner entrance 40 of the waste toner container 35 and the toner amount detecting device 42. Further, the image forming device is equipped with the waste toner storage device 39 for storing waste toner produced in image forming operation, and the waste toner storage device has the waste toner container which contains waste toner, a toner feeding means which is provided in the waste toner container and carries waste toner in the waste toner container 35 fed from the toner entrance of the waste toner container, and the toner amount detecting device 42 which detects that the waste toner container is full or nearly full of waste toner. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to an image forming apparatus provided with a waste toner storage device for storing waste toner generated during an image forming operation.

  2. Description of the Related Art In an image forming apparatus configured as an electronic copier, a printer, a facsimile, or a multifunction peripheral having at least two of these functions, a toner image formed on an image carrier surface or an intermediate transfer member surface is transferred to a recording medium. After the transfer of the toner image, the transfer residual toner adhering to the surface of the image carrier or the surface of the intermediate transfer member is removed by a cleaning device, and the removed waste toner is sent to and stored in a waste toner container of a waste toner storage device. I have.

  As such a waste toner storage device, a device in which waste toner entering a waste toner container is conveyed by a toner feeding unit and the waste toner in the waste toner container spreads over a wide range, thereby improving waste toner storage efficiency. Has been proposed. When the waste toner container becomes full or nearly full of toner, this is detected by the toner amount detecting device, the fact is reported to the operator, and the operator is prompted to perform an operation such as replacing the waste toner container. Devices configured in this way are also known.

  The waste toner container of the waste toner storage device is detachably mounted to the image forming apparatus main body directly or via another element. At this time, when the waste toner in the waste toner container is still full or has not reached a state close to this, for example, to repair or replace another element in the image forming apparatus main body, the waste toner container is used. Is usually removed from the image forming apparatus main body and then set again in the image forming apparatus main body. As described above, when the waste toner container is attached to or detached from the image forming apparatus main body, if the waste toner container is inclined, the waste toner in the waste toner container flows violently, and the waste toner is In some cases, the toner amount detection device stays biased at a portion of the toner amount detection unit where the toner amount is detected. When the waste toner container is set and used in the image forming apparatus main body in such a state, the toner amount detection device can use the waste toner container even though there is still enough space for accommodating the toner in the waste toner container. It is detected that the waste toner container is full or close to the waste toner container, thereby forcing the operator to uselessly work and causing economical loss.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming apparatus in which the above-mentioned conventional disadvantages are eliminated.

  In order to achieve the above object, the present invention includes a waste toner storage device for storing waste toner generated during an image forming operation, the waste toner storage device includes a waste toner container that stores waste toner, A toner feeding means provided in the waste toner container for conveying waste toner that has entered the waste toner container from the toner inlet of the waste toner container; and a state in which the waste toner container is full or nearly full of waste toner. An image forming apparatus having a toner amount detecting device for detecting that the toner amount has been detected by the toner amount detecting device inside the waste toner container. An image forming apparatus is proposed, in which a partition is provided from the side of the amount detection unit, and a shield is provided through which the toner feeding means penetrates.

  In this case, in the image forming apparatus according to claim 1, the lowermost portion of the toner feeding unit is located at a height level that is 1/2 of the total height of the waste toner container or in a region above the height level. Thus, it is advantageous to set the height position of the toner feeding member (claim 2).

  Further, in the image forming apparatus according to claim 1 or 2, the center in the height direction of the detection surface of the toner amount detection device facing the inside of the waste toner container has a height equal to の of the total height inside the waste toner container. It is advantageous to set the height position of the detection surface of the toner amount detection device so as to be located at the height level or at a height higher than that (claim 3).

  4. The image forming apparatus according to claim 1, wherein at least a portion of the toner feeding unit that penetrates the shield comprises a toner conveying screw, and the toner of the portion of the shield that penetrates the toner conveying screw. It is advantageous that the width of the conveying screw in the axial direction is set to be equal to or larger than the pitch of the spiral portion of the toner conveying screw.

  Further, in the image forming apparatus according to any one of claims 1 to 4, at least a portion of the toner feeding unit that penetrates the shield is formed of a toner conveying screw, and at least a portion of the shield that contacts the toner feeding unit is formed of an elastic body. (Claim 5).

  In the image forming apparatus according to the fifth aspect, it is advantageous that the shielding portion is formed of an elastic body made of a foam (claim 6).

  According to the image forming apparatus of the present invention, even when the waste toner container of the toner storage device is detached from the image forming apparatus main body, the waste toner inside the toner storage device remains in the toner amount detection unit, and the toner amount detection device Can effectively suppress the occurrence of a malfunction that is erroneously detected.

  According to the image forming apparatus according to the second and third aspects, the above-described operation and effect can be further ensured.

  According to the image forming apparatus of the fourth aspect, since the toner feeding means itself functions to enhance the sealing property of the shield portion through which the toner feed means penetrates, the effect provided by the first aspect is further ensured. can do.

  According to the image forming apparatus of the fifth and sixth aspects, the sealing property of the shield portion through which the toner feeding means penetrates can be enhanced by utilizing the elasticity of the shield, and therefore, the effect is achieved by the first aspect. The effect can be further ensured.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings, and the above-mentioned conventional disadvantages will be more specifically clarified with reference to the drawings.

  FIG. 1 is a schematic sectional view showing the internal structure of an image forming apparatus configured as a color printer. The image forming apparatus main body 1 shown here, that is, a housing thereof, includes a fixed main body 2 that is immovably mounted on an installation surface such as a floor surface, and a rotatable main body rotatably supported by the fixed main body 2. 3, a process unit 4 in which a plurality of process elements are integrally assembled is detachably mounted on the fixed main body 2. FIG. 2 is a sectional view showing the inside of the process unit 4.

  1 and 2, an endless belt-shaped photoconductor 8 constituting an example of an image carrier is wound around rollers 6 and 7 rotatably supported by a unit case 5 of the process unit 4. As the image carrier, a drum-shaped photoconductor, a dielectric drum or a dielectric belt can be used. A charging device including a charging charger 9 is disposed at a position facing the photoconductor 8, and the charging charger 9 is also supported by the unit case 5.

  As shown in FIG. 1, an exposure device configured as a laser writing unit 10, a rotary color developing unit 11, and a black developing unit 12 are supported on the fixed main body 2, respectively. Constitutes a developing device. The color developing unit 11 is configured as a unit in which a yellow developing unit 11Y, a magenta developing unit 11M, and a cyan developing unit 11C are integrally assembled, and the whole is rotatably supported by the fixed main body 2.

  During the image forming operation, the photoconductor 8 is rotated in the direction of arrow A by driving the roller 7 by a driving device (not shown). At this time, the surface of the photoreceptor is subjected to a charge removing operation by a charge removing device comprising a charge removing lamp 13 supported by the fixed main body 2, and then the surface of the photosensitive member is uniformly charged by a charging device comprising a charging charger 9, and the charged surface is charged. Exposure is performed by the light-modulated laser light L1 emitted from the laser writing unit 10, whereby a first electrostatic latent image is formed on the surface of the photoconductor. At this time, for example, the yellow developing device 11Y of the color developing unit 11 is positioned to face the surface of the photoconductor 8, and the first electrostatic latent image is visualized as a yellow toner image by the developing device 11Y. Is done. At this time, the black developing unit 12 is separated from the surface of the photoconductor 8, and does not perform the developing operation.

  On the other hand, the unit case 5 rotatably supports an appropriate number of, in this example, two rotating rollers 14 and 15 that are spaced apart from each other. An endless intermediate transfer belt 16 as one example is wound around, and one of the rotation rollers 14 is driven by a driving device (not shown), whereby the intermediate transfer belt 16 is rotationally driven in the direction of arrow B. The intermediate transfer belt 16 and the photoconductor 8 abut on each other at a transfer portion 17, and the front end of a transfer brush 18, which is an example of a first transfer unit, abuts on the back surface of the intermediate transfer belt 16 at this portion. The transfer brush 18 is also supported by the unit case 5. A transfer roller, a corona discharger, or the like can be used as the first transfer unit.

  As described above, when the yellow toner image formed on the surface of the photoconductor 8 reaches the transfer unit 17, a voltage having a polarity opposite to that of the toner is applied to the transfer brush 18, whereby the toner on the surface of the photoconductor 8 is The image is transferred to the surface of the intermediate transfer belt 16. The toner that has not been transferred remains adhered to the surface of the photoreceptor after the transfer of the toner image as described above. The transfer residual toner is supported by the unit case 5 and the leading end of the toner is transferred to the photoreceptor 8. It is scraped and removed by the first cleaning member comprising the cleaning blade 19 pressed against. The toner removed from the surface of the photoreceptor, that is, waste toner, falls into the toner receiver 20 integrated with the unit case 5. Other appropriate means such as a fur brush may be employed as the first cleaning member.

  The surface of the photoreceptor whose surface has been cleaned as described above is again subjected to the discharging operation by the discharging lamp 13, and thereafter is uniformly charged by the charging charger 9, and then the laser light emitted from the laser writing unit 10 on the charged surface L1 is irradiated to form a second electrostatic latent image on the surface of the photoconductor. When this latent image passes through the color developing unit 11, the rotation of the unit 11 causes, for example, a magenta developing unit 11M to face the photoconductor 8, whereby the second electrostatic latent image can be used as a magenta toner image. It is visualized. This toner image is also transferred to the surface of the intermediate transfer belt 16 on which the yellow toner image has been previously transferred by being superimposed on the yellow toner image by the operation of the transfer brush 18 in exactly the same manner as described above. . The toner remaining on the surface of the photoconductor 8 after the transfer of the magenta toner image is also removed from the surface of the photoconductor by the cleaning blade 19.

  In exactly the same manner as described above, a cyan toner image and a black toner image are sequentially formed on the photoreceptor surface by a cyan developing unit 11C and a black developing unit 12 facing the photoreceptor surface, respectively. The toner image is superimposed on the previously transferred toner image and sequentially transferred to the surface of the toner image 16. The cleaning blade 19 removes the residual toner from the surface of the photoreceptor every time each toner image is transferred, and the surface is cleaned. Thus, a full-color toner image is formed on the surface of the intermediate transfer belt 16.

  On the other hand, a recording medium 22 made of paper or a plastic sheet is stacked on a sheet feeding cassette 21 of a sheet feeding device arranged below the fixed main body 2, and the recording medium 22 is rotated by rotation of a sheet feeding roller 23 of the sheet feeding device. The medium 22 is fed one by one in the direction of arrow C. The recording medium 22 fed as described above is conveyed by a pair of conveying rollers 24 and a pair of registration rollers 25 rotatably supported by the rotating main body 3, and a full-color toner image formed on the surface of the intermediate transfer belt 16. Is fed into the nip between the intermediate transfer belt 16 and the transfer roller 26 opposed to the intermediate transfer belt 16. At this time, the full-color toner image on the surface of the intermediate transfer belt 16 is transferred to the surface of the recording medium 22 by the action of a voltage having a polarity opposite to that of the toner applied to the transfer roller 26. The transfer roller 26 constituting the second transfer unit is rotatably supported by the rotating main body 3, and an appropriate unit such as a corona discharger or a brush can be used as the second transfer unit. In the example shown in FIG. 1, the transport path of the recording medium 22 sent to the transfer roller 26 is formed in the rotating main body 3. However, the transport path may be formed by the wall surface of the unit case 5 of the process unit 4. .

  After leaving the intermediate transfer belt 16, the recording medium 22 onto which the full-color toner image has been transferred passes between the fixing roller 29 and the pressure roller 28 of the fixing device 27 supported by the fixed main body 2, and at this time, heat and The toner image is fixed on the surface of the recording medium 22 by the action of the pressure. The recording medium 22 that has exited the fixing device 27 is discharged with the image surface downward to a discharge stack portion 31 above the fixed main body by a pair of discharge rollers 30 rotatably supported by the fixed main body 2.

  On the other hand, the transfer residual toner adhering to the surface of the intermediate transfer belt 16 after transferring the full-color toner image onto the recording medium 22 is scraped off by the cleaning blade 32 having its leading end pressed against the surface of the intermediate transfer belt 16, and Sixteen surfaces are cleaned. The cleaning blade 32 constitutes an example of a second cleaning member. The cleaning blade 32 is fixed to an arm 33 swingably supported by the unit case 5 as shown in FIG. The untransferred toner scraped off from the intermediate transfer belt 16, that is, waste toner, is received by the toner receiver 34 fixed to the arm 33. As the second cleaning member, a cleaning member of another appropriate form such as a fur brush can be adopted.

  The cleaning blade 32 is freely movable toward and away from the surface of the intermediate transfer belt by the swing of the arm 33. When each toner image is transferred onto the surface of the intermediate transfer belt 16, the cleaning blade 32 is moved to the surface of the intermediate transfer belt. Away from After transferring the full-color toner image on the surface of the intermediate transfer belt to the recording medium 22, the tip of the cleaning blade 32 is pressed against the surface of the intermediate transfer belt by the swing of the arm 33 only when cleaning the transfer residual toner adhered to the surface. Then, the transfer residual toner is scraped off.

  The above description is about the image forming operation when forming a full-color image on the recording medium 22. However, a single-color image is formed using only one of the developing units constituting the color developing unit 11 and one of the black developing units 12. An image can be formed, or a two-color or three-color image can be formed.

  Further, in the illustrated image forming apparatus, a rotating main body 3 constituting a part of the image forming apparatus main body 1 is rotatable around a pivot pin 3A in the direction of arrow E in FIG. The process unit 4 is also pivotally supported so as to be rotatable in the direction of arrow E in FIG. 1 around the central axis of one of the rotation rollers 15 around which the intermediate transfer belt 16 is wound. The state of a part of the rotating main body 3 and the process unit 4 when rotated in this way is shown by a chain line in FIG.

  As described above, the transfer residual toner is removed from the surfaces of the photoconductor 8 and the intermediate transfer belt 16 by the cleaning blades 19 and 32, respectively. The waste toner generated during the image forming operation as described above is conveyed and sent to the waste toner container 35 of the waste toner storage device 39 as described later, and is stored in the waste toner container 35. The waste toner container 35 of the present example is detachably mounted on the container receiving portion 5a of the unit case 5 while keeping it substantially horizontal. When the rotating main body 3 and the process unit 4 are rotated to an open position shown by a chain line in FIG. 1, the upper portion of the waste toner container 35 is opened, so that the waste toner container 35 can be removed from the unit case 5. . In this example, the waste toner container 35 is detachably attached to the unit case 5 of the process unit 4, and the waste toner container 35 is detachably attached to the image forming apparatus main body 1 via the unit case 5. The waste toner container 35 may be configured to be directly and detachably supported on the image forming apparatus main body 1.

  As described above, since the waste toner container 35 is detachably attached to the image forming apparatus main body 1, when the waste toner container 35 becomes full or almost full with waste toner. Then, the waste toner container 35 can be easily removed from the image forming apparatus main body 1 and a new empty waste toner container can be mounted on the image forming apparatus main body 1. In this way, the waste toner container 35 can be replaced. However, in the image forming apparatus of this embodiment, even when the photoreceptor 8 is deteriorated and the life of the photoreceptor 8 reaches the end of its life, the rotation of the rotating main body 3 can be performed. The process unit 4 can be rotated to the open position shown by a chain line in FIG. 1, and the entire process unit 4 can be replaced with a new one.

  In the following description, it is assumed that the waste toner container 35 is full or almost full with waste toner, and that the waste toner container 35 needs to be replaced. It will be described as full or this is the end of life.

  Here, an example of a mode in which the transfer residual toner removed from the surfaces of the photoreceptor 8 and the intermediate transfer belt 16 is transported to the waste toner container 35 as waste toner will be described.

  The cleaning blade 32 shown in FIG. 2 extends in the width direction of the intermediate transfer belt 16, and a toner receiver 34 extends along the cleaning blade 32. A toner conveying screw 37 is arranged along the toner receiver 34. . The toner conveying screw 37 is driven to rotate around its central axis by a driving device (not shown) disposed in the image forming apparatus main body 1, and thereby the cleaning blade 32 scrapes off the surface of the intermediate transfer belt 16. The waste toner that has been removed and dropped onto the toner receiver 34 is conveyed to one end in the width direction of the intermediate transfer belt 16, in this example, a near side in a direction perpendicular to the paper surface of FIGS. 1 and 2.

  As shown in FIG. 3, one end of the toner conveying duct member 36 disposed on the front side of the unit case 5 is provided on the conveying path of the toner conveyed while being guided by the toner receiver 34. The side openings are connected and fixed. The duct member 36 extends obliquely downward as indicated by a dashed line in FIG. 1, and has another end opening connected and fixed to the front end of the toner receiver 20 shown in FIG. 2.

  The waste toner sent to the near side by the toner conveying screw 37 while being guided by the toner receiver 34 enters the duct member 36 from one end opening of the toner conveying duct member 36, and is dropped and conveyed inside the duct member 36 by its own weight. Is fed into the toner receiver 20 through the other end side opening.

  On the other hand, the cleaning blade 19 that is in pressure contact with the photoconductor 8 also extends long in the width direction of the belt-shaped photoconductor 8, and the toner receiver 20 extends along the cleaning blade 19. 38 are arranged. When the toner conveying screw 38 is driven to rotate by a driving device (not shown) on the image forming apparatus main body side, the waste toner removed from the photoconductor 8 by the cleaning blade 19 is guided to the toner receiver 20 while the toner is removed. The transport screw 38 is gathered at a collecting portion 47 on one end side (an end on the near side in FIGS. 1 and 2) in the longitudinal direction. At this time, the waste toner removed from the intermediate transfer belt 16 and transported through the toner transport duct member 36 and sent to the toner receiver 20 is also collected in the collection unit 47.

  As described above, the toner discharge port 50 (FIG. 2) is formed in the portion of the toner receiver 20 corresponding to the location where the waste toner is collected, and the toner guide tube 51 is connected and fixed. The lower opening of the toner guide tube 51 matches the toner inlet 40 formed in the waste toner container 35. In the illustrated example, a toner inlet 40 is formed in a part of the upper wall 35 a of the waste toner container 35, and the collected waste toner passes through the toner outlet 50 and the toner guide tube 51, and passes through the toner inlet 40 through the toner inlet 40. It is sent into the container 35 and stored here.

  As shown in FIGS. 2 and 3, a toner conveying screw 41 as an example of a toner feeding unit is provided inside the waste toner container 35. As shown in FIG. 4, the toner conveying screw 41 is configured as a screw conveyor including a central shaft 41A and a spiral portion 41B integrally formed therearound and formed by helically extending blades. Have been. The above-described toner conveying screws 37 and 38 have the same configuration as the screw shown in FIG. In FIG. 3, the toner conveying screws 37, 38, and 41 are shown in a simplified manner, and the same applies to FIGS. 6, 7, 10, and 11.

  The waste toner container 35 extends in the width direction of the photoreceptor 8 or the intermediate transfer belt 16, and each end of the shaft 41 </ b> A of the toner conveying screw 41 is attached to each longitudinal end wall 35 b, 35 c of the waste toner container 35. It is rotatably supported, and its shaft 41A is rotationally driven by a driving device disposed in the image forming apparatus main body. As a result, the toner feeding means including the toner feeding screw 41 feeds the toner T so that the waste toner T sent into the waste toner container 35 from the toner inlet 40 spreads over the entire area in the waste toner container 35 in the longitudinal direction. I do. In the example shown in FIG. 3, the direction of the spiral portion 41B (FIG. 4) of the blade of the toner conveying screw 41 is constant, and the waste toner T sent from the toner inlet 40 is directed to the opposite side. Transported. In this way, it is possible to prevent the waste toner T that has entered from the toner inlet 40 from being raised in a mountain shape at the portion of the toner inlet 40, and it is possible to increase the toner storage efficiency of the waste toner container 35.

  A toner feeding means other than the toner feeding screw shown in FIG. 4 can also be used. For example, a toner feeding device having a helical portion formed on a central shaft and a helical thread or helical groove formed on the outer peripheral surface thereof and extending in a spiral shape. A toner feeding member formed by spirally winding a linear material like a screw or a coil spring, or a toner feeding unit in which a toner feeding member of a different form is connected in the longitudinal direction can be used.

  The toner transport screw 41 transports the waste toner T as described above. At this time, if the toner transport screw 41 is located below the interior of the waste toner container 35 held in a substantially horizontal posture, Even when the toner conveying screw 41 rotates, the toner hardens in a bridge shape in the upper region of the waste toner container 35, and the toner may not be conveyed well.

  Therefore, in the image forming apparatus of the present embodiment, as shown in FIG. 2, the lowermost portion 41a of the toner feeding means composed of the toner conveying screw 41 is at a height level L which is １ ／ of the total height H of the waste toner container 35. The height position of the toner feeding means is set so as to be located in a region above or above. Preferably, the toner feeding means is disposed very near the upper wall 35a of the waste toner container 35.

  According to the above configuration, since the toner conveying screw 41 is located at the upper part in the waste toner container 35, when the toner conveying screw 41 rotates, a bridge of the waste toner is formed in the upper region in the waste toner container 35. Therefore, the waste toner can be efficiently transported over the entire area of the waste toner container 35 in the longitudinal direction.

  When the waste toner container 35 is full of waste toner, that is, when it has reached the end of its life, the waste toner container 35 is replaced with a new empty waste toner container as described above. Normally, the life of the waste toner container 35 is shorter than the life of the photoconductor 8, and is set to, for example, about の of the life of the photoconductor 8.

  When the waste toner container 35 reaches the end of its life, it is necessary to notify the operator of the fact. For this purpose, the waste toner container 35 is provided with a toner amount detecting device as shown in FIGS. 2, 3 and 5. 42 is provided, whereby it is detected that the waste toner container 35 is full of toner, and based on the detection signal, the fact is displayed on a display unit provided outside the image forming apparatus main body, The operator replaces the waste toner container 35 in accordance with the above-described procedure according to the display. As the toner amount detecting device 42, for example, a piezoelectric element is used.

  At this time, as shown in FIG. 3, a toner inlet 40 is formed at one end of the waste toner container 35 in the longitudinal direction, and a toner amount detecting device 42 is provided at the other end of the waste toner container 35. It is desirable to arrange. In this way, the waste toner T sent into the waste toner container from the toner inlet 40 is transported from one end to the other end by the toner transport screw 41, and the amount of waste toner transported is Is detected by the toner amount detecting device 42. Therefore, even if the number of the toner amount detecting devices 42 is one, the full state can be detected only when the waste toner container 35 is full of the waste toner. The state can be correctly detected.

  If a toner amount detecting device is provided near the toner inlet 40 shown in FIG. 3, the end of the waste toner container opposite to the toner inlet 40 is not yet filled with waste toner. The amount detecting device detects that the toner is full, and there is a problem that the waste toner container is replaced even though the toner can still be sufficiently stored.

  For the same reason, it is desirable to provide the toner amount detection device 42 in the upper region of the waste toner container 35. More specifically, as shown in FIG. 2, the height direction center D of the detection surface of the toner amount detection device 42 facing the inside of the waste toner container 35 is の of the total height H inside the waste toner container 35. The height position of the detection surface of the toner amount detection device 42 is set so as to be located at the height level L or higher. In the illustrated example, the center axis of the toner conveying screw 41 and the center D of the detection surface of the toner amount detection device 42 are substantially the same height.

  As described above, when the detection surface of the toner amount detection device 42 is arranged in an area above the height of the waste toner container 35, the detection device can detect the toner while the waste toner in the waste toner container 35 is small. The problem of detecting fullness can be prevented. When the waste toner container 35 is actually filled with waste toner, the fact is detected by the toner amount detecting device 42 for the first time. Therefore, the maximum amount of waste toner can be stored in the waste toner container 35, and the waste toner container 35 can be replaced with a new one in this state.

  The toner amount detection device 42 used in each configuration described above can be supported by an appropriate element, and may be fixedly supported on the side wall 35d of the waste toner container 35, for example. However, when the toner amount detecting device 42 is fixed to the waste toner container 35 in this manner, the toner amount detecting device 42 is also replaced every time the waste toner container 35 is replaced because the waste toner container 35 is a replacement part. This imposes a burden on the target.

  On the other hand, in the image forming apparatus of the present embodiment, as shown in FIGS. 2 and 5, the toner amount detecting device 42 is connected to the image forming apparatus main body 1 via a bracket (not shown). 2, the waste toner container 35 corresponding to the detection surface of the toner amount detection device 42 in a state where the waste toner container 35 is set at a predetermined position of the image forming apparatus main body as shown in FIG. A window hole 43 is formed in the portion indicated by, and the window hole 43 is covered with the thin film sheet 44. As the thin film sheet 44, for example, a flexible sheet made of rubber or synthetic resin having a thickness of 0.5 mm or less can be used.

  According to the above configuration, when the waste toner container 35 is set to the image forming apparatus main body 1, the detection surface of the toner amount detection device 42 faces the inside of the waste toner container 35 via the thin film sheet 44. Therefore, the toner full state can be detected without any trouble. Further, since the window hole 43 is covered with the thin film sheet 44, the toner in the waste toner container 35 does not leak outside through the window hole 43. .

  When the waste toner container 35 is full of toner and its life has expired, when the waste toner container 35 is detached from the image forming apparatus main body 1 as described above, the toner amount detecting device 42 It is left on the side of the main body 1. For this reason, the toner detecting device 42 is not replaced, and the economy can be improved. In the case of this configuration, a portion facing the detection surface of the flexible sheet 44 serves as a toner detection unit S where the toner amount is detected by the toner amount detection device 42. On the other hand, when the toner amount detecting device is fixed to the waste toner container 35 and its detection surface is directly exposed to the inside of the waste toner container 35, the detection surface serves as a toner detection unit.

  As described above, the image forming apparatus of the present example includes the waste toner storage device 39 for storing the waste toner generated during the image forming operation, and the waste toner storage device 39 includes the waste toner that stores the waste toner. A container 35, a toner feeding means provided in the waste toner container, for conveying the waste toner T that has entered the waste toner container 35 from the toner inlet 40 of the waste toner container 35, and a waste toner container And a toner amount detection device 42 for detecting that the state is full or nearly full at T.

  Further, in the waste toner container 39, the height positions of the toner conveying screw 41 and the toner amount detecting device 42 are set as described above so that the full state of the waste toner T in the waste toner container 35 can be correctly detected. ing. However, in the conventional waste toner storage device, even if such a configuration is employed, the toner amount detection device 42 may not be able to correctly detect the full state of the waste toner. For example, when the rotating main body 3 and the process unit 4 are opened as shown by a chain line in FIG. 1, the color developing unit 11 mounted on the fixed main body 2 is removed from the fixed main body 2, or the process unit 4 itself is repaired. Then, the process unit 4 is detached from the image forming apparatus main body 1. Then, after a predetermined operation is completed, the process unit 4 is set in the image forming apparatus main body 1. At this time, the waste toner container 35 is also detached together with the unit case 5, so that the waste toner T inside the unit case 5 flows violently. Then, as shown in FIG. 11, the waste toner T may be in a state where the waste toner T is biased to the portion of the toner amount detection unit S. When the waste toner container 35 is set in the image forming apparatus main body 1 in such a state, the toner amount is detected even when a large space for accommodating the waste toner is still left in the waste toner container 35. The device 42 will detect that the toner is full. In this case, the display unit indicates that the process unit needs to be replaced, so that the waste toner container 35 that can still be sufficiently used is replaced with a new waste toner container, thereby forcing the operator to perform useless work. Not only does it cause significant economic losses.

  Therefore, in the image forming apparatus of the present embodiment, as shown in FIGS. 3 and 6, the above-described toner inlet 40 and the toner amount detection device 42 are provided inside the waste toner container 35 of the waste toner storage device 39. A shielding body 45 is provided to partition from the side of the toner amount detection unit S where the toner amount is detected, and to penetrate the above-mentioned toner feeding means. In the illustrated example, the shielding body 45 is made of a plate material fixed to the inner wall surface of the waste toner container 35, and a through hole 46 is formed in an upper portion thereof, where a toner conveying screw 41 as an example of a toner feeding unit is provided. Extends through it. The interior of the waste toner container 35 is partitioned by a shield 45 into a first space W1 and a second space W2, and these spaces W1 and W2 are communicated only by the above-described through hole 46. Further, it is desirable that the shielding body 45 is provided at a portion as close as possible to the toner amount detecting portion S, and preferably, as close as possible.

  According to the above-described configuration, the waste toner T in the first space W1 on the side of the toner inlet 40 moves to the second space W2 on the side of the toner amount detection unit S substantially only by the toner conveying screw 41. I can only. Therefore, as described above, when the movable main body 3 and the process unit 4 are opened, the unit case 5 is detached from the image forming apparatus main body 1 together with the waste toner container 35, and the waste toner container 35 is greatly inclined. As shown in (5), the waste toner T in the first space W1 is prevented from moving to the second space W2 by the shield 45. For this reason, it is possible to prevent the problem that the full state of the waste toner is detected even though the life of the waste toner container 35 has not reached the conventional state. Also, when the waste toner container 35 detached from the image forming apparatus main body 1 is tilted in a state where the waste toner is slightly fed into the second space W2 by the toner conveying screw 41, the waste toner container 35 If not, the waste toner in the second space W2 can be prevented from staying in the toner amount detection unit S. Since the toner conveying screw 41 extends through the through hole 46 of the shield 45, when a large amount of waste toner accumulates in the first space W1 with the progress of the image forming operation, the waste toner is obstructed. Without being transported to the second space W2.

  By the way, in the image forming apparatus of the present embodiment, as described above, the lowermost part of the toner feeding means composed of the toner conveying screw 41 is at the height level L which is の of the total height H of the waste toner container 35, or The height position of the toner feeding member is set so as to be located above the region. Therefore, a large amount of waste toner T accumulates in the first space W1, and if the height does not reach the toner conveying screw 41, the waste toner T is not conveyed to the second space W2. If the amount of the waste toner in the waste toner container 35 does not increase significantly, the waste toner does not exist in the second space W2. Therefore, until the waste toner container 35 is used for a long time and a large amount of waste toner is present in the second space W2, the waste toner container 35 is detached from the image forming apparatus main body 1 and tilted greatly. However, the waste toner T does not flow to the toner amount detection unit S and does not stay there, and erroneous detection of the toner amount detection device 42 can be prevented for a long time.

  Further, in the image forming apparatus of this example, as described above, the height direction center D of the detection surface of the toner amount detection device 42 facing the inside of the waste toner container 35 The height position of the detection surface of the toner amount detection device 42 is set so as to be located at a height level of ２ or higher. For this reason, even if the waste toner container 35 is detached from the image forming apparatus main body 1 and is tilted in a state where some waste toner exists in the second space W2, the waste toner T is transmitted to the toner amount detection unit S. The problem of flowing and staying here can be effectively prevented, and erroneous detection of the toner amount detecting device 42 can be prevented for a long period of time.

  Further, in each configuration described above, the toner feeding means penetrating the shield 45 can be configured in various modes as described above. As shown in FIG. 4, a toner conveying screw 41 having a shaft 41A and a helical portion 41B integral with the shaft 41A is used. It is advantageous to set the pitch to be equal to or greater than the pitch P of the spiral portion 41B of the screw. For example, as shown in FIG. 8, a shielding body 45 is formed by attaching a plate-shaped main body 45A and a cylindrical portion fixed to the main body 45A so as to conform to a through hole 46 (FIG. 3) formed in the main body. 45B, the toner conveying screw 41 is passed through the cylindrical portion 45B, and the axial width G of the screw 41 of the cylindrical portion 45B including the thickness of the main body 45A is changed to the spiral portion 41B of the toner conveying screw 41. Is set to be larger than the pitch P (FIG. 4).

  With this configuration, the toner conveying screw 41 has a central shaft 41A and a helical portion 41B fixed therearound, and occupies a portion penetrating the shielding body 45, and furthermore, the helical portion 41B 8 is smaller than the width G of the penetrating portion, the portion of the shield 45 through which the toner conveying screw 41 penetrates, in the example of FIG. The screw 41 is positioned to fill up. For this reason, the sealing property between the first space W1 and the second space W2 is improved, and the waste toner container 35 remains in the first space W1 even when the waste toner container 35 is detached from the image forming apparatus main body and tilted. It is possible to more effectively prevent the waste toner T from moving to the second space W2 through the gap between the through hole 46 of the shield 45 and the toner conveying screw 41. In this way, it is possible to more effectively prevent the waste toner from flowing into the toner amount detection unit S and staying there.

  In each of the above-described configurations, if at least a portion of the toner feeding unit that penetrates the shield 45 is formed by the toner conveying screw 41 and at least a portion of the shield that is contacted by the toner feeding unit is formed of an elastic body, Since the body enters the groove between the spiral portion 41B projecting in the radial direction from the shaft 41A of the toner conveying screw 41, the above-mentioned sealing performance is further improved, and the occurrence of erroneous detection of the toner amount detecting device 42 is more effectively performed. Can be prevented. For example, as shown in FIG. 9, the entirety of the shield 45 is formed of non-foamed soft rubber or soft foam, and the toner conveying screw (see FIG. 9) has a spiral outer diameter larger than the diameter of the through hole 46. 9 (not shown in FIG. 9) is passed through the through hole 46. As a result, the inner wall portion of the through hole of the shielding body 45 made of an elastic body is largely elastically deformed by being pressed by the helical portion at a portion in contact with the projecting helical portion, and the groove between the helical portions at the portion therebetween. As a result, the gap between the through hole 46 and the toner conveying screw 41 is effectively closed, and the sealing property between the first space W1 and the second space W2 is enhanced.

  At this time, if at least the shielding portion contacting the toner feeding means is formed of an elastic body made of a foam, the portion is softer and more easily elastically deformed, so that the above-mentioned sealing effect can be further enhanced. .

  The present invention can be applied to various types of image forming apparatuses other than the above-described image forming apparatuses. For example, as shown in FIG. 10, the toner conveying screw 38 provided at the bottom of the toner receiver 20 (FIG. 2) is divided into two portions 38a and 38b, and the directions of the spiral portions of the blades of these portions 38a and 38b are changed. Conversely, by rotating the toner conveying screw 38, the waste toner removed from the photoconductor 8 by the cleaning blade 19 shown in FIG. The present invention can also be applied to an image forming apparatus configured to be collected. Also in this case, a portion of the waste toner container 35 corresponding to the portion where the waste toner T is collected is formed with a toner inlet 40, through which the collected waste toner is sent into the waste toner container 35. Then, the toner conveying screw 41 constituting the toner feeding means in the waste toner container 35 also includes two portions 141A and 141B, and the spiral directions of its blades are opposite to each other. The waste toner thus conveyed is conveyed from the center in the longitudinal direction toward the respective ends. Then, the toner amount detecting unit S of the toner amount detecting device 42 is located at each end, and when one or both of the toner amount detecting devices 42 detects that the toner is full, a full display is displayed on the display unit.

  Also in the image forming apparatus having such a configuration, the toner inlet 40 and the toner amount detector S where the toner amount is detected by the toner amount detectors 42 are separated into the waste toner container 35 and the toner By providing the two shields 45 through which the feeding means penetrates, and further adopting each of the above-described configurations, the operation and effect of each of the above-described configurations can be directly obtained. In the case of this example, one first space W1 and two second spaces W2 are partitioned by the waste toner container 35 and the two shields 45.

  The present invention is also widely applicable to image forming apparatuses that do not use an intermediate transfer member, image forming apparatuses that form a single-color image, and image forming apparatuses such as an electronic copying machine other than a printer, a facsimile machine, or a multifunction peripheral thereof. You can do it.

FIG. 1 is a schematic sectional view illustrating an example of an image forming apparatus. FIG. 3 is a cross-sectional view illustrating an internal configuration of the process unit, in which a static elimination lamp, a transfer roller, and a toner amount detection device are added. FIG. 4 is an explanatory cross-sectional view illustrating the principle of a waste toner storage device and a device that transports waste toner to the waste toner container. FIG. 3 is a partial view of a toner conveying screw. FIG. 4 is a vertical cross-sectional view of a waste toner container that is full of waste toner. FIG. 4 is a partially cutaway perspective view schematically showing the internal structure of a waste toner container. It is explanatory sectional drawing which clarifies the effect of a shield. It is a perspective view of the shield which has a cylindrical part. It is a perspective view of the shield which consists of an elastic body. FIG. 4 is an explanatory sectional view similar to FIG. 3, illustrating another example of a waste toner storage device. FIG. 4 is an explanatory sectional view similar to FIG. 3 for explaining a conventional problem.

Explanation of reference numerals

35 Waste Toner Container 39 Waste Toner Container 40 Toner Inlet 41 Toner Conveying Screw 41a Bottom 41B Spiral Part 42 Toner Amount Detector 45 Shield D Center G Width H Total Height L Level P Pitch S Toner Amount Detector T Waste Toner

Claims (6)

A waste toner storage device for storing waste toner generated during an image forming operation, wherein the waste toner storage device is provided in the waste toner container and the waste toner container; And a toner amount detecting device for detecting that the waste toner container is full or nearly full with waste toner from the toner inlet of the waste toner container. In the image forming apparatus having
Inside the waste toner container, a partition for separating the toner inlet side and a toner amount detecting unit from which the toner amount is detected by the toner amount detecting device is provided, and a shielding body through which the toner feeding unit penetrates is provided. An image forming apparatus comprising: The height position of the toner feeding member is set such that the lowermost part of the toner feeding means is located at a height level of 1/2 of the total internal height of the waste toner container or in an area higher than the height level. Item 2. The image forming apparatus according to Item 1. The height direction center of the detection surface of the toner amount detection device facing the inside of the waste toner container is located at a height level that is １ ／ of the total inner height of the waste toner container, or at a height higher than that. 3. The image forming apparatus according to claim 1, wherein a height position of a detection surface of the toner amount detection device is set. At least the toner feeding means portion penetrating the shield is formed of a toner conveying screw, and the axial width of the toner conveying screw in the shield portion penetrating the toner conveying screw is set to be equal to or greater than the pitch of the spiral portion of the toner conveying screw. The image forming apparatus according to claim 1, wherein: 5. The image forming apparatus according to claim 1, wherein at least a portion of the toner feeding means penetrating the shield is formed of a toner conveying screw, and at least a portion of the shielding body contacting the toner feeding means is formed of an elastic body. The image forming apparatus according to claim 5, wherein the shield portion is made of an elastic body made of a foam.

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