JP2017134291A - Developer conveyance device and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a developer conveyance device capable of properly executing the conveyance of a developer.SOLUTION: A toner supply mechanism includes: a toner bottle for storing a toner (t); and a hopper container 16 having a conveyance screw 29 for conveying the toner supplied from the toner bottle to the downstream side of a toner conveyance direction 42b. Further, the toner supply mechanism includes: a conveyance path toner detection sensor 33 directing a detection surface 33a capable of detecting the toner inside a hopper container to the inside of the hopper container; and a cleaning member 38 provided on a position where it can face the detection surface on the conveyance screw, for cleaning the toner in the vicinity of the detection surface by rotation of the screw. The cleaning member 38 can elastically slide on the detection surface accompanied with the rotation of the conveyance screw, and makes a top end edge part 44a become gradually long from the upstream side of the toner conveyance direction to the downstream side.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a developer conveying device used in an image forming apparatus such as a facsimile, a copying machine, and a printer.

  2. Description of the Related Art Conventionally, there is known an image forming apparatus equipped with a developing device that develops an electrostatic latent image (electrostatic image) formed on an image carrier into a toner image using a developer.

  In such an image forming apparatus using a developer, when the developer is transported by a transport screw or the like, the developer is transferred from the developer container such as a toner bottle to the developer container in the developing device within a predetermined amount within a predetermined time. If the developer is not transported, there is an apparatus that is configured to stop the apparatus main body as an error. In this configuration, whether or not a predetermined amount of developer (toner) has been transported within a predetermined time is determined based on a detection time of a toner sensor that is disposed in the developer transport path and detects the presence or absence of toner. (See Patent Document 1).

JP 2010-256894 A

  However, as in the developer replenishment system described in Patent Document 1, the timing of replenishment from the developer container to the developer container is determined by a toner sensor disposed in the developer conveyance path that communicates from the developer container to the developer container. Attempting to do so may cause the following problems. That is, the toner sensor may detect the toner remaining only around the detection surface of the toner sensor even though all the developer from the developer container is conveyed to the developer container. In this case, an event that the developer is not replenished from the developer storage container (developer storage means) even though the toner hardly exists in the developer transport path is caused.

  In order to avoid the above phenomenon, a flat scraping member is provided in a direction substantially perpendicular to the detection surface from the conveying screw so as to scrape the detection surface so that toner does not stay in the vicinity of the detection surface of the toner sensor. A technique is known in which toner in the vicinity of a detection surface is scraped off by moving in synchronization with a rotating conveying screw. However, the flat scraping member is provided in a rectangular shape vertically from the shaft portion of the conveying screw toward the toner sensor. For this reason, even if the toner is scraped off, it is dropped again in the vicinity of the detection surface of the toner sensor only by scraping upward, and the speed at which the toner is conveyed is also reduced.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a developer transport device that can appropriately transport a developer.

  The present invention relates to a developer conveying device having developer accommodating means for accommodating a developer, and a conveying member for conveying the developer supplied from the developer accommodating means to the downstream side in the developer conveying direction, in the developer conveying device. A developer detecting means having a detection surface capable of detecting the developer in the developer conveying portion directed toward the developer conveying portion, and a position facing the detection surface in the conveying member, A cleaning member that cleans the developer in the vicinity of the detection surface by the rotation of the conveying member, and the cleaning member can be elastically slidably contacted with the detection surface as the conveying member rotates, and the developer The tip edge portion is inclined so that the length in the direction orthogonal to the transport direction gradually increases from the upstream side to the downstream side in the developer transport direction.

  The present invention relates to a developer conveying device having developer accommodating means for accommodating a developer, and a conveying member for conveying the developer supplied from the developer accommodating means to the downstream side in the developer conveying direction, in the developer conveying device. A developer detecting means having a detection surface capable of detecting the developer in the developer conveying portion directed toward the developer conveying portion, and a position facing the detection surface in the conveying member, A cleaning member that cleans the developer in the vicinity of the detection surface by rotation of the transport member, and the transport member is a transport screw that rotates around the rotation shaft and transports the developer in the rotation axis direction. The screw pitch in the region close to the cleaning member is narrower than the screw pitch in other regions.

  The present invention includes, in the developer conveying apparatus, a developer accommodating unit that accommodates the developer, and a first conveying member that conveys the developer supplied from the developer accommodating unit to the downstream side in the developer conveying direction. Provided at a position where the developer conveying section, a detection surface capable of detecting the developer in the developer conveying section facing the inside of the developer conveying section, and a position facing the detection surface of the conveying member And a cleaning member that cleans the developer in the vicinity of the detection surface by rotation of the transport member, and has a second transport member that transports the developer cleaned by the cleaning member to the downstream side. To do.

  According to the present invention, it is possible to appropriately carry the developer.

1 is a cross-sectional view schematically showing the overall structure of an image forming apparatus according to an embodiment of the present invention. FIG. 3 is a cross-sectional view illustrating a schematic configuration of a toner supply mechanism according to the embodiment. (A) is front sectional drawing which shows the state which the cleaning member contacted the detection surface, (b) is a side view which shows the state of (a) in the state seen from the left of a figure, (c) is the state of (a). Front sectional drawing which shows the contact state of the cleaning member in the state which the conveyance screw rotated further from the position. (A) is a figure which expands and shows the conveyance screw which concerns on this embodiment, (b)-(e) is a figure which shows the state of the cleaning member which changes sequentially with rotation of a conveyance screw in steps. FIG. 3 is a control block diagram showing a control system related to toner supply according to the present embodiment. 5 is a flowchart showing a flow of processing of a toner supply operation according to the present embodiment. FIG. 3 is a front view illustrating a schematic configuration of a toner supply mechanism according to the present embodiment. Sectional drawing which expands and shows a conveyance path toner detection sensor and a scraping member. Sectional drawing which shows a hopper container, a developing device, etc. when toner supply is controlled along the flowchart of FIG. FIG. 5A is a cross-sectional view showing how toner in the toner transport path is decreasing, and FIG. 5B is a cross-sectional view showing how toner in the toner transport path is exhausted. FIG. 6C is a cross-sectional view illustrating a state in which toner is supplied until the toner is replaced with a new toner bottle and is detected by a conveyance path toner detection sensor. FIG. 6 is a graph showing a detection waveform when 1 [g] of toner is supplied from a toner bottle when a scraping member serving as a basis of the present embodiment is used. FIG. 5 is a graph showing a detection waveform when 1 [g] of toner is supplied from a toner bottle when a flat elastic member serving as a basis of the present embodiment is used. FIG. 5 is a graph showing a detection waveform when 1 [g] of toner is supplied from a toner bottle when the flat plate-like support portion and the seal-like elastic member of FIGS. 2 to 4 are used.

  Hereinafter, an image forming apparatus 1 according to an embodiment of the present invention will be described with reference to the drawings. First, the overall structure of the image forming apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 1 is a cross-sectional view schematically showing the overall structure of the image forming apparatus 1 according to the present embodiment. In the following, the front side facing a control panel (not shown) where the user makes various inputs and settings to the image forming apparatus 1 is referred to as “front side” of the image forming apparatus 1 and the back side is referred to as “back side”. That is, FIG. 1 is a cross-sectional view showing the internal configuration of the image forming apparatus 1 as viewed from the front side. In FIG. 1, a toner replenishing mechanism (developer conveying device) 15 to be described later is not shown.

  As shown in FIG. 1, the image forming apparatus 1 includes an apparatus main body 1a, and includes a sheet feeding apparatus 2 that feeds the sheet S at a lower portion in the apparatus main body 1a. Further, a control unit 7 as a control means is provided in the apparatus main body 1a. Above the sheet feeding device 2 in the apparatus main body 1a, an image forming unit 3 that forms an image on the fed sheet S, a fixing device 4 that fixes the image on the sheet S, and a sheet on which the image is fixed A sheet discharge unit 5 for discharging S is sequentially arranged. An image reading unit 6 capable of reading an image of a document is disposed on the upper part of the apparatus main body 1a. The image forming unit 3 and the fixing device 4 constitute an image forming unit.

  The sheet feeding device 2 includes a stacking tray 21 on which sheets S are stacked, a pickup roller 22 that feeds out the sheets S stacked on the stacking tray 21, and a separation feeding that separates and feeds the sheet S that has been fed out by the pickup roller 22. Part 23. Further, the sheet feeding apparatus 2 includes a manual feeding unit 24 that can manually feed the sheet S from the side surface side of the image forming apparatus 1. The manual feeding unit 24 includes an openable / closable manual feeding tray 25 on which the sheets S are stacked, and a separation feeding unit 26 that separates and feeds the sheets S stacked on the manual feeding tray 25.

  The image forming unit 3 electrostatically applies a photosensitive drum 31 as an image carrier on which a toner image is formed, a charging roller 32 that uniformly charges the surface of the photosensitive drum 31, and a laser beam to the photosensitive drum 31. And a laser irradiation device 39 for forming a latent image. Further, the image forming unit 3 includes a developing device 34 that visualizes an electrostatic latent image on the photosensitive drum 31 as a toner image, and a transfer roller 35 that contacts the photosensitive drum 31 to form a transfer nip N. . The developing device 34 includes a developing sleeve 14 that supplies toner to the surface of the photosensitive drum 31. The developing device 34 constitutes developing means for developing the electrostatic latent image formed on the photosensitive drum 31 with toner (developer) t. The image forming apparatus 1 according to the present embodiment is configured to transport and replenish toner t to the developing device 34 by a toner replenishing mechanism (developer transporting device) 15 described later.

  The fixing device 4 is arranged in a sheet conveyance path downstream of the image forming unit 3 in the sheet conveyance direction (hereinafter also simply referred to as “downstream side”), and includes a fixing unit 40 and a cooling fan 41.

  The sheet discharge unit 5 is disposed on the downstream side of the fixing device 4, and includes a discharge roller pair 51 that discharges the sheet S from the inside of the apparatus main body 1 a and a discharge tray 52 on which the discharged sheets S are stacked. Yes.

  The image reading unit 6 includes a document placing unit 61 for placing a document (not shown), and a reading scanner 62 for reading image information of the document placed on the document placing unit 61. In FIG. 1, the illustration of the toner bottle unit 27, the toner conveyance path 28, and the peripheral portion thereof shown in FIG.

  Next, an image forming operation for executing an image forming job by the control unit (control unit) 7 of the image forming apparatus 1 having the above-described configuration will be described.

  In other words, when the image forming job is started, the laser irradiation device 39 detects the image of the photosensitive drum 31 in accordance with image information (image information signal) such as a document transmitted from a personal computer (PC) (not shown) or the reading scanner 62. The surface is irradiated with laser light. As a result, the surface of the photosensitive drum 31 that has been uniformly charged to a predetermined polarity potential by the charging roller 32 is exposed, and an electrostatic latent image is formed on the surface of the photosensitive drum 31. The electrostatic latent image formed on the photosensitive drum 31 is developed by the developing device 34 and visualized as a toner image.

  In parallel with the toner image forming operation described above, the sheet S separated and fed one by one from the sheet feeding device 2 is registered by the pair of conveying rollers 10 in the sheet conveying path on the downstream side thereof. As the leading edge of the sheet S hits the nip of the registration roller pair 11 that is stopped, the skew is corrected. Thereafter, the skewed sheet S is conveyed to the transfer nip portion N at a predetermined timing, and the visualized toner image on the photosensitive drum 31 is transferred by the transfer roller 35.

  The sheet S to which the toner image has been transferred is conveyed from the transfer nip portion N to the fixing device 4 and is heated and pressed by the fixing unit 40 to melt the toner and be fixed on the sheet S as an image. Thereafter, the sheet S on which the image is fixed is discharged to the discharge tray 52 by the discharge roller pair 51, and the image forming job is completed.

[Toner supply mechanism]
Next, a toner replenishing mechanism 15 as a developer conveying device provided in the image forming apparatus 1 will be described with reference to FIG. FIG. 7 is a front view illustrating a schematic configuration of the toner supply mechanism 15 of the present embodiment.

  That is, as shown in FIG. 7, the toner replenishing mechanism 15 has a toner bottle unit 27, and the toner bottle unit 27 includes a toner bottle as a developer storage unit that stores toner (developer) t. 27b is rotatably mounted. When the toner bottle 27 b is rotated by driving the toner bottle motor 13, the toner t is discharged from the toner supply port 27 a provided in the toner bottle unit 27 to the toner conveyance path 28.

  The toner transport path 28 has a toner receiving port 16c communicating with the toner replenishing port 27a on the upper surface, and discharges toner t to the toner receiving portion 34b of the developing device 34 at one end of the transport surface (lower surface) 16a. A toner discharge port 16b is provided. In the toner conveyance path 28, shaft support holes 16d and 16e are provided at both end portions in the left-right direction in FIG. The conveying screw (conveying member) 29 has a spiral portion 29a formed so as to be spirally wound in one direction around the shaft portion 29b. The conveying screw (conveying member) 29 rotates around a shaft portion (rotating shaft) 29b and conveys toner (developer) t in the rotating shaft direction.

  When the toner t is supplied to the toner conveyance path 28, the toner t is conveyed along the toner conveyance path 30 including the paths indicated by the arrows 30 a and 30 b by the spiral portion 29 a of the conveyance screw 29 that is rotated by driving the conveyance screw motor 12. The toner receiving portion 34b of the lower developing device 34 is replenished. The toner conveyance direction is a direction indicated by an arrow 30a in FIG. 7, and a direction indicated by an arrow 42b in FIGS.

  The toner bottle 27b is detachably provided on the toner bottle unit 27 and can be replaced by a user or the like.

  Further, in the toner conveyance path 28, a conveyance path toner detection sensor 33 as a toner detection unit is disposed. A flat scraping member 46 is provided at a position facing the conveyance path toner detection sensor 33 of the conveyance screw 29. The conveyance path toner detection sensor 33 exposes a detection surface 33 a capable of detecting the toner t into the hopper container 16 from the conveyance surface 16 a of the hopper container 16 where the toner t is conveyed by the rotation of the conveyance screw 29. The conveyance path toner detection sensor 33 outputs a detection signal when the toner t is detected on the detection surface 33a to the control unit 7 (see FIG. 7). The conveyance path toner detection sensor 33 constitutes a developer detection unit.

  In addition, a developing container 34 a that stores toner t to be supplied to the photosensitive drum 31 is provided in the developing device 34. Further, a developing device toner detection sensor 36 is disposed on the inner wall portion of the developing container 34a of the developing device 34, and this sensor 36 determines whether or not the toner t is at a predetermined height in the developing container 34a. The detection signal is output to the control unit 7 (see FIG. 1). Note that, as the conveyance path toner detection sensor 33 and the developing device toner detection sensor 36 in this embodiment, for example, a magnetic permeability detection sensor, a piezo sensor, or the like can be used.

  Here, the scraping member 46 of the present embodiment that prevents the toner t from staying on the detection surface 33a of the conveyance path toner detection sensor 33 will be described with reference to FIGS. 8 is an enlarged cross-sectional view of the conveyance path toner detection sensor 33 and the scraping member 46, and FIG. 9 is a hopper container 16 and developing device when toner supply is controlled according to the flowchart of FIG. FIG.

  As shown in FIGS. 8 and 9, a scraping member 46 is provided on the transport screw 29 so as to face the detection surface 33 a of the transport path toner detection sensor 33 disposed in the toner transport path 28. The scraping member 46 stands up in a flat plate shape in a direction substantially orthogonal to the detection surface 33a so that the detection surface 33a of the conveyance path toner detection sensor 33 can be scraped when the conveyance screw 29 rotates. The toner is removed so as not to stay on the detection surface 33a. The conveying screw 29 is made of a resin material such as ABS, and the flat scraping member 46 is made of a flexible resin material such as urethane, and the detection surface of the shaft portion 29b of the conveying screw 29. It is configured such that it is bonded to a portion facing 33a with a double-sided tape or the like and protrudes from the shaft portion 29b. The conveying screw (conveying member) 29 fixes a flexible sheet in the longitudinal direction of the shaft portion (rotating shaft) 29b, and rotates around the shaft portion 29b to convey the developer in the circumferential direction of the shaft portion 29b. To do.

  Next, a control system related to toner supply according to the present embodiment will be described with reference to FIG. FIG. 5 is a control block diagram showing a control system related to toner supply according to the present embodiment.

  As shown in FIG. 5, a developing device toner detection sensor 36 and a conveyance path toner detection sensor 33 are connected to the control unit 7 having a CPU, RAM, and ROM, and the conveyance screw motor 12 and toner are output to the output. A bottle motor 13 is connected. The control unit 7 outputs drive signals to the transport screw motor 12 and the toner bottle motor 13 based on detection signals from the developing device toner detection sensor 36 and the transport path toner detection sensor 33.

[Toner supply operation when toner is in toner bottle]
Next, a toner replenishing operation when toner is present in the toner bottle will be described with reference to FIGS. FIG. 6 is a flowchart showing the flow of the toner supply operation.

  That is, the toner replenishing operation is performed in parallel with the operation of forming an image on the sheet S. When the toner replenishing operation is performed, the control unit 7 (FIGS. 1 and 5) first determines whether or not the developing device toner detection sensor 36 has detected the toner t. When the control unit 7 determines that the toner t is not detected, the control unit 7 drives the conveying screw motor 12 (FIG. 7). As a result, the conveying screw 29 rotates in the toner conveying path 28 of the hopper container 16 to convey the toner t, and is supplied from the toner discharge port 16b to the toner receiving portion 34b. On the other hand, when it is determined that the developing device toner detection sensor 36 has detected the toner t, the control unit 7 stops driving the conveying screw motor 12 and stops the toner supply to the developing device 34.

  Further, the control unit 7 determines whether or not the conveyance path toner detection sensor 33 detects the toner t (S301). If the controller 7 determines that the transport path toner detection sensor 33 has detected the toner t (S301: YES), the process is terminated.

  On the other hand, when it is determined in step S301 that the conveyance path toner detection sensor 33 does not detect the toner t (S301: NO), the control unit 7 performs the toner bottle motor 13 until the conveyance path toner detection sensor 33 detects the toner t. Is turned on (driven) (S302). As a result, the toner t is supplied from the toner bottle 27 b to the toner conveyance path 28. Then, when the conveyance path toner detection sensor 33 detects the toner t (step S303: YES), the control unit 7 turns off (stops) the toner bottle motor 13 to stop toner supply (S305), and ends the processing. To do.

  If the conveyance path toner detection sensor 33 determines that the toner t is not detected (step S303: NO), the control unit 7 determines whether or not a predetermined time has elapsed (S304). (S304: NO) The process returns to step S303. On the other hand, if it is determined that the predetermined time has elapsed (S304: YES), the control unit 7 turns off (stops) the toner bottle motor 13 to stop toner supply (S306), and sets the toner to be out.

  As described above, when the developing device toner detection sensor 36 no longer detects toner, the control unit 7 drives the conveying screw motor 12 to rotate the conveying screw 29 and supplies the toner t from the toner conveying path 28 to the developing device 34. Supply. When the conveyance path toner detection sensor 33 stops detecting the toner t, the toner bottle motor 13 is driven to rotate the toner bottle 27b, and the toner t is supplied from the toner bottle 27b to the toner conveyance path 28. By repeating the above operation, the toner t can be smoothly supplied from the toner bottle 27 b to the toner conveyance path 28 and from the toner conveyance path 28 to the developing device 34.

[Toner supply operation when toner in the toner bottle runs out]
Next, a toner replenishing operation when the toner t in the toner bottle 27b runs out will be described with reference to FIGS. FIGS. 10A to 10C are views showing a state in which the toner bottle 27b is replaced with a new toner bottle 27b after the toner in the toner bottle runs out. FIG. 10A is a diagram illustrating a state in which the toner t in the toner conveyance path 28 decreases. FIG. 10B is a diagram illustrating a state when the toner t in the toner conveyance path 28 is exhausted. FIG. 10C is a diagram illustrating a state in which the toner t is supplied from the toner bottle 27b to the toner conveyance path 28 until the toner bottle 27b is replaced with a new toner bottle 27b and the conveyance path toner detection sensor 33 detects the toner t. It is.

  That is, when the toner t is supplied from the toner bottle 27b to the toner conveyance path 28 and the developing device 34 and image formation is performed, the developing device toner detection sensor 36 eventually can detect the toner t and the conveyance path toner detection. The sensor 33 is in a state where it cannot detect toner.

  As shown in FIG. 10A, even when the toner t in the toner bottle 27b runs out and the conveyance path toner detection sensor 33 cannot detect the toner t, the image forming process is executed and the development is performed. The toner t in the device 34 is consumed. As the toner t is consumed, the developing device toner detection sensor 36 cannot detect the toner t.

  In this case, the conveying screw motor 12 is driven as described above, and the toner t is supplied from the toner discharge port 16 b of the toner conveying path 28 to the toner receiving portion 34 b of the developing device 34 by the rotation of the conveying screw 29. At this time, since the toner cannot be supplied from the toner bottle 27b to the toner conveyance path 28, the toner t in the toner conveyance path 28 is developed from the toner discharge port 16b every time the conveyance screw motor 12 is driven. It is reduced by being discharged to the toner receiving portion 34b of the device 34.

  In this state, when the image forming process is continued, the toner supply by the conveying screw motor 12 continues to be executed, and eventually the toner t does not exist in the toner conveying path 28, that is, the conveying screw motor 12 supplies the toner t. It is not idle.

  Then, as shown in FIG. 10B, when the developing device toner detection sensor 36 does not detect toner and the developing device toner detection sensor 36 does not detect toner even after a predetermined time has elapsed, the control unit 7 Determines that there is no toner in the toner bottle 27b. Then, on the operation unit (not shown), which is a display means, the content for prompting the replacement of the toner bottle 27b is displayed, and the image forming job is not accepted, that is, the image forming apparatus 1 is not in the image forming state. . This is the idle period during which the conveying screw motor 12 is not supplying the toner t.

  Further, as shown in FIG. 10C, when the toner bottle 27b that has run out of toner t is replaced with a new toner bottle 27b that is filled with toner t, the toner bottle 27b enters the toner conveyance path 28 and the developing device 34. The toner t is replenished sequentially. Then, the conveyance path toner detection sensor 33 and the developing device toner detection sensor 36 detect the toner t, that is, the toner supply operation is completed.

  In the above operation sequence, the toner replenishment sequence is executed.

  Here, FIG. 11 shows a detection waveform of the toner t by the conveyance path toner detection sensor 33. As shown in FIG. 11, since an analog waveform is used as an output value, when there is toner t around the conveyance path toner detection sensor 33, the output value increases when the toner t around the conveyance path toner detection sensor 33 is large. When the value is small, the output value becomes small. FIG. 11 is a graph showing a detection waveform when 1 [g] of toner t is supplied from the toner bottle 27b when only the flat scraping member 46 is opposed to the detection surface 33a to clean the detection surface 33a. It is. In the graphs of FIG. 11 and FIGS. 12 and 13 described later, the output (V) of the conveyance path toner detection sensor 33 is taken on the vertical axis, and the time (t) is taken on the horizontal axis. 11 to 13 represents a waveform when 1 [g] is supplied from the toner bottle 27b.

  If the timing for replenishing the developing container 34a from the toner bottle 27b with the transport path toner detection sensor 33 exposed in the toner transport path 28 communicating with the developing container 34a from the toner bottle 27b, the following problems may occur. There is. That is, although the toner t is sent from the toner bottle 27b to the developing container 34a, the toner t remaining around the detection surface 33a is detected by the conveyance path toner detection sensor 33, and the toner in the toner conveyance path 28 is detected. An event in which replenishment is not performed from the bottle 27b occurs.

  FIG. 11 shows a waveform when only the flat scraping member 46 is used. When the toner t enters the toner conveyance path 28 and the conveyance path toner detection sensor 33 detects the toner t, the waveform rises as shown in FIG. . Actually, if it is an analog output, it gradually rises a little more, but in FIG. 11 and later-described FIGS. 12 and 13, it is described so that it can be easily understood.

  In FIG. 11, the signal W in the form of a triangular wave is output from the conveyance path toner detection sensor 33 because the flat scraping member 46 scrapes off the toner t near the detection surface 33 a in accordance with the rotation of the conveyance screw 29. Is going up and down. However, since the scraping amount by the scraping member 46 is small and does not reach the OFF region in the digital waveform, the ON state continues in the digital waveform and the toner replenishment indicated by the pulse P is not performed. It will be.

  In the case of the configuration example corresponding to FIG. 11, a plate-like scraping member 46 is formed so as to stand a wall substantially perpendicular to the detection surface 33 a from the shaft portion 29 b of the conveying screw 29, and the scraping member 46 is The toner t is rotated together with the conveying screw 29 so that the toner t does not stay around the detection surface 33a. However, the flat scraping member 46 extended from the conveying screw 29 strictly restricts the dimensional tolerance between the tip and the detection surface 33a, or restricts the detection range of the detection surface 33a. Is extremely difficult.

  In the case of the configuration example corresponding to FIG. 11, since the surface where the scraping member 46 contacts the detection surface 33 a is formed horizontally with respect to the surface 33 a, the force for conveying the toner in the toner conveyance direction. Therefore, the operation of lifting and dropping is repeated. Therefore, the conveyance path toner detection sensor 33 in the configuration example of FIG. 11 has a problem that the same toner scraped off is detected many times. Therefore, it takes time to reach an appropriate OFF state.

  On the other hand, FIG. 12 shows a configuration example in which, in addition to the flat plate-like scraping member 46, a rectangular seal-like elastic member whose tip is parallel is provided. FIG. 12 shows the relationship between the replenishment operation when the toner t is replenished from the toner bottle 27 b and the output of the conveyance path toner detection sensor 33.

  In the case of the configuration example corresponding to FIG. 12, unlike the configuration of the present embodiment corresponding to FIG. 13, the tip portion where the sealing elastic member is in contact with the detection surface 33 a has a waveform in a horizontal state. In FIG. 12, compared with the configuration example of FIG. 11, ON / OFF of the conveyance path toner detection sensor 33 can be detected with certainty, but it takes some time to determine ON / OFF. Further, as shown in FIG. 12, when the toner t is replenished from the toner bottle 27b to the toner transport path 28, the transport path toner detection sensor 33 detects the toner t after a short time, and the toner is transferred to the developing container 34a. It can be seen that t is being conveyed. In this configuration example, although the amount is as small as 1 [g], detection is continued for about 20 seconds and the next replenishment operation is performed.

  In the present embodiment shown in FIG. 13 which is solved together with the problems of both FIG. 11 and FIG. 12, the length of the leading edge 44a of the seal-like elastic member 44 is changed with respect to the toner conveying direction. Thus, the remaining toner remaining around the detection surface 33a is appropriately scraped off, and the toner conveying force by the conveying screw 29 is not reduced.

  That is, FIG. 13 shows the output value according to this embodiment of the conveyance path toner detection sensor 33 when the toner t is replenished from the toner bottle 27b to the toner conveyance path 28 by a certain amount, and the same amount as compared with FIG. The detection time required for replenishing toner t is short. As a result, it can be seen that the toner t is transported without staying in the transport path toner detection sensor 33.

  Hereinafter, this embodiment will be described in detail with reference to FIGS. FIG. 2 is a cross-sectional view showing a schematic configuration of the toner supply mechanism according to the present embodiment. FIGS. 3A to 3C are diagrams illustrating the cleaning member 38 and the conveyance path toner detection sensor 33 according to the present embodiment in different states. 3A is a front sectional view showing a state in which the cleaning member 38 is in contact with the detection surface 33a, and FIG. 3B is a side view showing the state in which FIG. 3A is viewed from the left side of FIG. is there. FIG. 3C is a front sectional view showing a contact state of the cleaning member 38 in a state in which the conveying screw 29 is further rotated from the position of FIG. 4A is an enlarged view showing the conveying screw 29 according to this embodiment, and FIGS. 4B, 4C, 4D, and 4E are sequentially shown as the conveying screw 29 rotates. It is a figure which shows the state of the cleaning member 38 which changes in steps.

  That is, in this embodiment, as shown in FIG. 2, the toner (developer) t near the detection surface is cleaned by the rotation of the conveyance screw 29 provided at a position that can face the detection surface 33 a of the conveyance screw 29. A cleaning member 38 is provided. The cleaning member 38 can be elastically slidably contacted with the detection surface 33a as the conveying screw 29 rotates, and the length in the direction perpendicular to the toner conveying direction 42b (the vertical direction in FIG. 2) is upstream of the toner conveying direction 42b. The tip edge portion 44a is inclined so as to become gradually longer from the downstream side (the right side in FIG. 2) toward the downstream side (the left side in FIG. 2).

  The cleaning member 38 has rigidity on the side close to the shaft portion 29b of the conveying screw 29, and has elasticity on the side facing the tip edge portion 44a from the portion having the rigidity. That is, the cleaning member 38 is provided on the shaft portion 29b and has a flat plate-like support portion 43 having rigidity that protrudes in a flat plate shape toward the detection surface 33a, and a flat plate-like support portion with the tip edge portion 44a facing the detection surface 33a. And a seal-like elastic member 44 fixed to the flat plate-like support portion 43 so as to protrude from 43.

  In the present embodiment, the seal-like elastic member 44 fixed to the flat plate-like support portion 43 is lengthened from the upstream side to the downstream side in the toner transport direction 42b, and as shown in FIG. The portion of the member 44 on the downstream side in the toner conveyance direction rotates with a large delay from the upstream side. At this time, the plate-like support portion 43 is integrally formed with the conveying screw 29 and has the same hardness as the shaft portion 29b. However, since the plate-like support portion 43 is formed relatively thin, the rotation of the shaft portion 29b is accompanied by the rotation of the shaft portion 29b. Deforms to bend in the opposite direction.

  The tip edge portion 44a of the seal-like elastic member 44 is bent and deformed so as to push out the toner t along the toner conveyance direction as shown in FIGS. 4B, 4C, 4D, and 4E described later. . As a result, the toner conveying force by the rotating conveying screw 29 is not reduced, and the toner t staying on the detection surface 33a is not repeatedly detected, and the toner detection by the conveying path toner detecting sensor 33 is properly performed. It can be carried out. In FIG. 4A, the conveying screw 29 rotates from the near side to the far side as shown by the arrow. Reference numeral 45 indicates an opening direction of the bending of the sealing elastic member 44.

  Here, referring to FIG. 2 and FIGS. 3A to 3C, the cleaning member 38 having the flat plate-like support portion 43 and the seal-like elastic member 44 according to the present embodiment, the conveyance path toner detection sensor 33, and the like. The installation part will be described. The positional relationship between FIG. 2 and FIG. 7 is an image in which the directions of FIG. 2 and FIG. 7 are reversed left and right, and the toner discharge port 16b of FIG. 2 is on the right side in FIG. The toner replenishing port 27a is located substantially at the center in FIG.

  As shown in FIG. 2 and FIG. 3A, the seal-like elastic member 44 is affixed to the entire surface of the flat plate-like support portion 43, and the tip edge 44a thereof is detected from the tip of the flat plate-like support portion 43. It protrudes to the 33a side. In this embodiment, the flat plate support portion 43 is fixed using a double-sided tape. However, the mounting method is not limited to this, and the flat plate support portion 43 may be attached with an adhesive, or the flat plate support portion 43 and the sealing elastic member 44 may be attached. It may be molded simultaneously.

  3B and 3C, for example, a urethane sheet (thickness of about 0.3 mm) is attached to the flat plate support portion 43 with a double-sided tape. Since the seal-like elastic member 44 is configured to rub against the detection surface 33a, the seal-like elastic member 44 is affixed to the entire area of the flat plate-like support portion 43 with double-sided tape so as to make it as difficult as possible to peel off.

  4 (b), (c), (d), and (e) show the situation in which toner is sent as the deflection amount of the seal-like elastic member 44 changes, from the direction of arrow J in FIG. 4 (a). Shows the state of viewing. 4 (b) to 4 (e), the entire portion of the flat plate-like support portion 43 is disposed on a portion in the rotational direction with respect to the flat plate-like support portion 43 (the right side surface of the flat plate-like support portion 43 in FIG. Since the seal-like elastic member 44 is pasted so as to extend, the plate-like support portion 43 is actually not visible.

  In FIG. 4B, the flat plate support portion 43 and the conveyance path toner detection sensor 33 are in the closest state, as shown in FIGS. 4C, 4D, and 4E. When the rotation of the conveying screw 29 progresses sequentially, the distance between the flat plate-like support portion 43 and the detection surface 33a increases. Then, as the rotation of the conveying screw 29 further proceeds, the bending is released, and finally the sealing elastic member 44 is separated from the detection surface 33a.

  As described above, the seal-like elastic member 44 bends with respect to the detection surface 33a, so that the strength of one seal-like elastic member 44 varies depending on the location. Therefore, the seal-like elastic member 44 has a weaker strength and a larger amount of deflection as the distance from the flat plate-like support portion 43 is longer than a portion where the distance from the flat plate-like support portion 43 is short. Accordingly, since a slope is formed from a strong part to a weak part, the toner t can be sent out in the toner transport direction (developer transport direction) 42b by forming it in the toner transport direction 42b.

  As described above, the detection surface 33a can be properly secured by simply fixing the seal-like elastic member 44 to the flat plate-like support portion 43 formed integrally with the shaft portion 29b with the tip edge portion 44a facing the detection surface 33a. The cleaning member 38 that can be cleaned easily can be obtained easily.

  Note that this embodiment is merely an example. For example, in the description contents and drawings described in the above configuration example, the positions of the conveyance path toner detection sensor 33 and the seal-like elastic member 44 are the same as the description contents and the positions of the drawings. It can be in any position. That is, the conveyance path toner detection sensors 33 may be disposed at a plurality of positions in the axial direction of the conveyance screw 29 in the hopper container 16, and the cleaning member 38 corresponds to each of the plurality of conveyance path toner detection sensors 33. A plurality of them may be arranged. As a result, the same cleaning effect for the detection surface 33a as described above can be obtained, and more accurate toner detection can be performed.

  Further, the length of the sealing elastic member 44 in the direction of the outer diameter of the conveying screw does not depend on the outer diameter of the conveying screw 29, and the same effect can be obtained even if the length differs to some extent. Similarly, the length of the seal-like elastic member 44 in the toner conveying direction is not dependent on the pitch of the spiral portions 29a, and the same effect can be obtained even if the length is somewhat different.

  According to the present embodiment described above, the cleaning member 38 is elastically deformed when the conveying screw 29 is rotated, the tip edge 44a is brought into sliding contact with the detection surface 33a, and the toner on the detection surface is stirred while the toner conveyance direction 42b. It becomes possible to carry and clean it downstream. Accordingly, the toner t can be reliably prevented from staying in the vicinity of the detection surface 33a that detects the toner t in the toner conveyance path 28 that communicates the toner bottle 27b and the developing container 34a. For this reason, the transport path toner detection sensor 33 can accurately detect the toner t supplied from the toner bottle 27b to the hopper container 16, smoothly transport the toner to the downstream side of the hopper container 16, and Can be properly replenished.

  Further, according to the present embodiment, the amount of deflection of the seal-like elastic member 44 increases toward the downstream side in the toner conveyance direction by elongating the seal-like elastic member 44 from the upstream side to the downstream side in the toner conveyance direction 42b. . For this reason, the amount of deflection is released from the upstream side in the toner conveying direction in the direction of the arrow 45 in FIG. 4A, so that the downstream side where the large amount of deflection is left forms a slope with respect to the toner conveying direction. Thus, the toner t can be sent out downstream in the transport direction. As a result, the toner t scraped from the detection surface 33a of the conveyance path toner detection sensor 33 can be reliably conveyed downstream, while avoiding the inconvenience of detecting the same toner t many times, It becomes possible to perform replenishment appropriately. As described above, according to the present exemplary embodiment, toner retention of the toner detection sensor can be prevented without causing a decrease in toner conveyance speed.

  In the present embodiment, the configuration in which the seal-like elastic member 44 is attached to the flat plate-like support portion 43 is described as an example in which the configuration is applied to the conveyance path toner detection sensor 33. However, the present invention is not limited to this. It is also possible to apply to 36. Even in that case, it is possible to obtain the same effect.

  Further, the conveying member is not limited to the conveying screw, and a stirring sheet that fixes a flexible sheet in the longitudinal direction of the rotating shaft, rotates around the rotating shaft, and conveys the developer in the circumferential direction of the rotating shaft. It may be a unit.

  Further, the pitch of the conveying screw 29 is not constant in the axial direction, and the conveying amount in the region close to the cleaning member 38 is reduced by making the screw pitch in the region close to the cleaning member 38 narrower than the screw pitch in other regions. It may be configured to prevent this.

  Further, the number of conveying members is not limited to one, and in addition to the main first conveying member (for example, conveying screw 29) that mainly conveys toner (developer) t in the developer conveying portion to the downstream side, a cleaning member. In order to prevent a reduction in the conveyance amount in a region close to 38, an auxiliary second conveyance member may be provided near the cleaning member 38. The second conveying member conveys the toner t cleaned by the cleaning member 38 to the downstream side.

  Further, the above-described embodiment and other configurations may be implemented alone or in combination.

DESCRIPTION OF SYMBOLS 1 ... Image forming apparatus 15 ... Toner replenishment mechanism (developer conveyance apparatus)
16 ... Hopper container (developer transport section)
16a ... Conveying surface (lower surface)
27b ... Toner bottle (developer storage means)
29 ... Conveying screw (conveying member, first conveying member)
29b ... shaft part 31 of conveying screw ... photosensitive drum (image carrier)
33 ... Transport path toner detection sensor (developer detection means)
33a ... detection surface 34 ... developing device (developing means)
38 ... Cleaning member 42b ... Toner transport direction (developer transport direction)
43 ... Flat plate support 44 ... Sealing elastic member 44a ... Tip edge t ... Toner (developer)

Claims (9)

Developer accommodating means for accommodating the developer;
A developer transport unit having a transport member for transporting the developer supplied from the developer containing means to the downstream side in the developer transport direction;
A developer detecting means having a detection surface capable of detecting the developer in the developer transport section facing the developer transport section;
A cleaning member provided at a position that can be opposed to the detection surface in the transport member, and cleaning the developer near the detection surface by rotation of the transport member;
The cleaning member can be elastically slidably contacted with the detection surface along with the rotation of the conveying member, and the length in the direction orthogonal to the developer conveying direction is changed from the upstream side to the downstream side in the developer conveying direction. The tip edge is inclined so as to become gradually longer toward the
A developer conveying device characterized by that. The cleaning member has rigidity on the side close to the shaft portion of the transport member, and the side facing the tip edge from the portion having the rigidity has elasticity,
The developer conveying device according to claim 1, wherein: The cleaning member is
A flat plate-like support portion provided on the shaft portion of the transport member and having rigidity protruding in a flat plate shape toward the detection surface;
A seal-like elastic member fixed to the flat plate-like support portion so as to protrude the tip edge portion from the flat plate-like support portion toward the detection surface,
The developer conveying apparatus according to claim 1, wherein the developer conveying apparatus is a developer conveying apparatus. The developer detecting means exposes the detection surface in the developer transport unit from a lower surface of the developer transport unit where the developer is transported by rotation of the transport member.
The developer conveying device according to any one of claims 1 to 3, wherein the developer conveying device according to claim 1 is used. The transport member is a transport screw that rotates around a rotation shaft to transport the developer in the rotation shaft direction.
5. The developer conveying device according to claim 1, wherein the developer conveying device is provided. The conveying member fixes a flexible sheet in the longitudinal direction of the rotating shaft, rotates around the rotating shaft, and conveys the developer in the circumferential direction of the rotating shaft.
5. The developer conveying device according to claim 1, wherein the developer conveying device is provided. Developer accommodating means for accommodating the developer;
A developer transport unit having a transport member for transporting the developer supplied from the developer containing means to the downstream side in the developer transport direction;
A developer detecting means having a detection surface capable of detecting the developer in the developer transport section facing the developer transport section;
A cleaning member provided at a position that can be opposed to the detection surface in the transport member, and cleaning the developer near the detection surface by rotation of the transport member;
The conveying member is a conveying screw that rotates around a rotation axis to convey the developer in the rotation axis direction, and a screw pitch in a region close to the cleaning member is narrower than a screw pitch in other regions.
A developer conveying device characterized by that. Developer accommodating means for accommodating the developer;
A developer transport unit having a first transport member for transporting the developer supplied from the developer containing means to the downstream side in the developer transport direction;
A developer detecting means having a detection surface capable of detecting the developer in the developer transport section facing the developer transport section;
A cleaning member provided at a position that can be opposed to the detection surface in the transport member, and cleaning the developer near the detection surface by rotation of the transport member;
A second transport member that transports the developer cleaned by the cleaning member to the downstream side;
A developer conveying device characterized by that. An image carrier;
An image forming apparatus comprising: a developing unit that develops the electrostatic latent image formed on the image carrier with a developer;
The developer is conveyed to the developing means by the developer conveying device according to any one of claims 1 to 8.
An image forming apparatus.

Images