JP2005134725A - Toner supply device and toner detection method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner supply device and a toner detection method, in which the presence of toner can securely be detected while making a predetermined amount of toner remain in a toner holding container. <P>SOLUTION: The toner holding container 40 has a first arcuate bottom plate 451 whose cross-section orthogonal to a stirring shaft 51 has the shape of an arc having the axial center of the stirring shaft 51 as its curvature center. The stirring member 50 includes rectangular stirring vanes 54 made of a flexible material whose edge is fixed parallel with the stirring shaft 51 and whose size is set such that a projection amount from the stirring shaft 51 is longer than the curvature radius of the bottom of the toner holding container 40. A toner sensor 80 is disposed while its detection end faces the external surface of the first arcuate bottom plate 451. A toner sweeping plate 55 whose sweeping force exerted on the first arcuate bottom plate 451 is greater than the other parts is formed on a part of each stirring vane 54, which corresponds to the toner sensor 80. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is to supply toner to a developing device that forms a toner image by supplying toner to the peripheral surface of a photosensitive drum provided in an image forming apparatus such as a copying machine, a facsimile machine, and various printers. The present invention relates to a toner supply device that is detachably attached to the developing device and a toner detection method used in the toner supply device.

  Conventionally, a toner supply device as described in Patent Document 1 is known. This toner supply device is detachably attached to a developing device used for supplying toner to a photosensitive drum of an image forming apparatus, and supplies toner to the developing device. Such a toner supply device includes a cylindrical toner loading container and a toner stirring member concentrically housed in the toner loading container, and stirs the toner loaded in the toner loading container with the toner stirring member. It is like that.

  The toner stirring member includes a stirring shaft concentric with the toner loading container, and a stirring blade made of a flexible material protruding from the peripheral surface of the stirring shaft. The amount of protrusion from the stirring shaft is set slightly longer than the inner diameter dimension of the toner loading container, and the stirring blade rotates about the stirring shaft while being elastically deformed and slidingly contacting the inner peripheral surface of the toner loading container. ing. Due to the rotation of the rotating blade, the toner in the toner loading container is sufficiently agitated and uniformed, and then sent to the developing device.

  In general, a toner sensor for detecting the presence or absence of toner is provided outside the toner loading container. Usually, for example, an electrostatic capacitance type toner sensor is employed, and the detection end is provided with the detection end facing the bottom from the outside of the toner supply container. The presence of the toner is detected by facing the detection end through the bottom of the container.

  The developing device is also provided with an agitating unit for agitating the toner, which is configured in the same manner as the toner loading container, and the toner is supplied to the photosensitive drum in a sufficiently agitated state here as well. Yes. Incidentally, in the developing device described in Patent Document 2, the toner stirring structure is different from that of Patent Document 1, and a part of the stirring blade having a rectangular shape is separated from the other by the stirring shaft. A cleaning blade is provided that is fixed and has a slightly longer protrusion from the stirring shaft than the others.

On the other hand, the toner storage container of the developing device is provided with a pair of protruding pieces projecting from the inner surface toward the stirring shaft at the bottom of the circular arc having an arc shape, and the cleaning blade responds to rotation around the stirring shaft. And pass between the pair of protruding pieces. A light emitting element is mounted on one protruding piece, and a light receiving element is provided on the other protruding piece so as to face the light emitting element. Accordingly, since the cleaning blade cleans between the pair of protruding pieces each time the stirring blade rotates, when the toner is present in the toner storage container, the toner between the protruding pieces is once removed, and then the toner is again removed from the pair of protruding pieces. Therefore, the light from the light-emitting element does not reach the light-receiving element due to this light shielding, so that it can be detected that the toner is present in the toner storage container. On the other hand, when there is not enough toner in the toner storage container, the light receiving element is always in a light receiving state, thereby detecting toner out.
JP 7-199621 A JP 2001-175071 A

  By the way, in the toner detection structure as described in Patent Document 1, the rotary blade uniformly rubs the arc bottom surface of the toner loading container at the tip edge portion thereof. After all of the toner has been swept away, the toner sensor embedded at the bottom detects toner out.

  However, if toner out is detected only after the toner storage container is completely emptied, the image forming apparatus is not used until the user replaces the toner supply apparatus with a new one after knowing that the toner has run out. There is a disadvantage that it cannot be used. When the toner supply device is in stock, it is possible to keep the image forming device unusable period to a minimum by immediately replacing it. However, if the toner supply device is not in stock, it is necessary to order a new toner supply device. In the meantime, the image forming apparatus cannot be used, which is very inconvenient.

  On the other hand, in the toner detection structure described in Patent Document 2, the presence of the toner is detected by reinserting the toner between the protruding pieces after the toner is once swept away. Therefore, when the toner becomes an amount that cannot move between the protruding pieces, that is, when it is determined that the toner has run out in a state where a considerable amount of toner still remains in the toner storage container, No such inconvenience as in the toner detection structure disclosed in Japanese Patent Application Laid-Open No. H10-260260 is not generated. However, the toner detection structure becomes complicated, such as a pair of projecting pieces projecting from the bottom surface of the toner storage container, and high accuracy is required because the cleaning blade must pass between the projecting pieces accurately, and the apparatus cost is increased. Has the problem of increasing.

  The present invention has been made in view of such a situation, and is capable of reliably detecting the presence or absence of toner after allowing a predetermined amount of toner to remain in the toner loading container. It is an object to provide a supply device and a toner detection method.

  According to the first aspect of the present invention, there is provided a toner loading container, an agitating member for rotating the agitation shaft provided between opposing wall surfaces of the toner loading container, and a toner agitated by the agitating member. A toner supply device configured to detect whether the toner in the toner loading container is present or not by a toner sensor provided outside the toner loading container. The toner loading container has an arcuate bottom portion having a substantially arcuate cross section perpendicular to the agitation shaft, and the agitation member has a proximal edge fixed in parallel to the agitation shaft, and a distal edge Has an agitating blade facing the arcuate bottom, and the toner sensor is provided with a detection end facing the arcuate bottom outside the toner loading container, and the agitating blade corresponds to the toner sensor. In part, in which the toner sweeping force of the circular arc shaped bottom portion, characterized in that the larger other parts sweep strength portion of the stirring blade is formed.

  According to the present invention, the toner loaded in the toner loading container is agitated by the rotation of the agitating blade around the agitation shaft, so that even if there is a solidified solid, it is unraveled and evenly distributed. In a distributed state, the sheet is fed toward the developing device by driving the conveying member.

  The agitating blade is formed with a sweeping force enhancing portion in which the toner sweeping force at the arcuate bottom portion is larger than the other portions at a portion corresponding to the toner sensor provided at the arcuate bottom portion of the toner loading container. As the stirring blade rotates about the stirring axis, the sweeping force increasing portion presses the portion of the arc-shaped bottom portion where the toner sensor is provided more strongly than the other portions, so that the vicinity of the toner sensor is closer to the toner than the other portions. Is reliably removed.

Therefore, the toner sensor outputs a toner out detection signal when the remaining amount is such that the toner sensor does not flow into the vicinity of the toner sensor from which the toner has been removed, so that the user is approaching the toner out. In addition to being able to recognize this, even after the detection signal is output, the image forming process by the image forming apparatus can be continued temporarily until the inside of the toner loading container is completely emptied.

  As described above, the toner-out detection signal of the toner sensor can be used as a signal for preparing a new toner-loading container for replacement, which is extremely useful in avoiding inconvenience for the user. It is valid.

  According to a second aspect of the present invention, in the first aspect of the invention, the sweep-out force increasing portion is configured such that the amount of protrusion of the stirring blade from the stirring shaft is set larger than the other part of the stirring blade. It is a feature.

  According to this invention, the sweeping force increasing portion of the stirring blade is elastic in a state where it is in contact with the arc surface of the lower arc portion by setting the protruding amount from the stirring shaft to be larger than the other portion of the stirring blade. Since the deformation amount is larger than that of the other portion and the arc-shaped bottom portion is pressed with a larger force, the toner in the portion where the toner sensor exists is more reliably swept out. In this way, the sweeping force enhancing portion can be formed with a simple configuration in which a part of the stirring blade is slightly protruded in the radial direction of the stirring shaft, which can contribute to a reduction in component costs.

  According to a third aspect of the present invention, in the second aspect of the present invention, the sweep-out force enhancing portion has a cut formed by cutting from both ends of the portion protruding from the stirring blade toward the stirring shaft. It is characterized by that.

  According to this invention, the sweeping force increasing portion of the stirring blade is formed between the pair of cuts formed in the stirring blade, so that it can be elastically deformed in a state independent of other portions of the stirring blade. Accordingly, it is possible to reliably remove the toner at the arc-shaped bottom portion in a state along the position where the toner sensor exists.

  According to a fourth aspect of the present invention, in the invention according to the second or third aspect, the sweep-out force increasing portion is supported by a support protrusion whose base end portion protrudes from the stirring shaft. Is.

  According to the present invention, the sweeping force increasing portion is less elastically deformed by the support protrusion provided on the base end side of the cut, so that the amount of deformation (angle) of the elastically deformable portion is increased. This provides a greater sweeping force on the arcuate bottom.

  The invention according to claim 5 is the invention according to any one of claims 1 to 4, wherein the stirring blade is fixed to the stirring shaft via a predetermined intermediate member. .

  According to the present invention, it is possible to select various mounting states of the stirring blade with respect to the stirring shaft depending on the situation due to the presence of the intermediate member, and the versatility of the toner stirring structure is increased.

  According to the sixth aspect of the present invention, a toner sensor for detecting the presence / absence of toner in the toner loading container is provided outside the toner loading container, and the toner in the vicinity of the installation site of the toner sensor is slightly deeper than the toner in other parts. Using the cleaning means for cleaning, the inside of the toner loading container is in an empty state by setting the toner sensor in a state where the remaining amount of toner in the toner loading container is very small and leading the toner sensor to the out-of-toner state in advance. This is a toner detection method characterized by detecting this.

  According to the present invention, since the cleaning unit sweeps out the toner in advance from the part where the toner sensor is present, it detects that the container is empty with some toner remaining in the toner loading container. Therefore, this detection signal can be used as a signal for preparing a new toner loading container for replacement, and the user can be prevented from feeling inconvenient.

  According to the first aspect of the present invention, the toner sensor outputs a toner out detection signal when the residual amount in the toner loading container is such that the toner sensor does not flow into the vicinity of the removed toner sensor. Therefore, the user can not only recognize that the toner is about to run out, but also temporarily after the detection signal is output until the toner loading container is completely emptied. The image forming process by the image forming apparatus can be continued.

  In this way, the toner out-of-toner detection signal of the toner sensor can be used as a signal for preparing a new toner loading container for replacement, so that the user is not inconvenienced. .

  According to the second aspect of the present invention, it is possible to form the sweeping force increasing portion with a simple configuration in which a part of the stirring blade is slightly protruded in the radial direction of the stirring shaft, thereby ensuring improvement in detection accuracy of the toner sensor. In addition, it can contribute to the reduction of parts cost.

  According to the third aspect of the present invention, the sweeping force enhancing portion can be elastically deformed in a state independent of other portions of the stirring blade due to the presence of the cut, and accordingly, the toner sensor is located at the position where the toner sensor exists. The toner at the bottom of the arcuate shape can be reliably removed while being along.

  According to the fourth aspect of the present invention, since the sweeping force increasing portion is less elastically deformed by the support protrusion provided on the base end side of the cut, the amount of deformation (angle) of the portion that can be elastically deformed ) Is increased, thereby obtaining a greater sweeping force on the arcuate bottom.

  According to the fifth aspect of the present invention, since the stirring blade is fixed to the stirring shaft via a predetermined intermediate member, various mounting states of the stirring blade with respect to the stirring shaft due to the presence of the intermediate member can be varied depending on the situation. This makes it possible to increase the versatility of the toner stirring structure.

  According to the sixth aspect of the present invention, it becomes possible to use the detection signal of the empty in the toner loading container of the toner sensor as a signal for preparing a new toner loading container for replacement, which is inconvenient for the user. Can be prevented.

  FIG. 1 is a side sectional view showing an embodiment of an image forming apparatus to which a toner cartridge (toner supply device) 20 according to the present invention is applied. As shown in FIG. 1, an image forming apparatus 10 includes a document image reading unit 12 including an optical system such as a lens and a mirror in a box-shaped device body 11, and the document image reading unit 12 reads the document. The image forming unit 13 that transfers the original image to the paper P, the fixing unit 14 that fixes the transfer image transferred to the paper P by the image forming unit 13, and the sheet feeding one by one toward the image forming unit 13 A sheet storage unit 15 for storing sheets to be stored is built in, and a document placement unit 16 for placing a document on the top of the apparatus main body 11 is provided.

The document placing portion 16 includes a contact glass (not shown) fitted in an opening on the top surface of the apparatus main body 11 and a document pressing cover 161 that can be opened and closed with respect to the contact glass. Then, with the document pressing cover 161 opened, the document is placed on the contact glass with the document surface facing down, and the document pressing cover 161 is closed and is not provided at a suitable position on the upper surface of the apparatus main body 11. When the start button is pressed, the document image reading unit 12 optically reads the document surface, and the obtained document information is converted into a digital signal by a CCD (charge coupled device) and temporarily stored in a predetermined storage device. It has come to be remembered.

  The image forming unit 13 includes a photosensitive drum 131 having a photosensitive surface formed on a circumferential surface that rotates clockwise around an axis in FIG. 1 and a rotating surface facing the circumferential surface of the photosensitive drum 131. The charging unit 132, the exposure unit 133, the developing unit (developing device) 134, the transport belt 135, and the cleaning device 137 are sequentially provided.

  The charging unit 132 forms a uniform charge on the peripheral surface of the photosensitive drum 131 rotating by corona discharge. The exposure unit 133 sequentially irradiates the peripheral surface of the photoconductive drum 131 based on the original image information read by the original image reading unit 12 and digitized and stored in the storage device, with laser light. As a result, an electrostatic latent image is formed on the peripheral surface of the photosensitive drum 131. The developing unit 134 supplies toner to the peripheral surface of the photosensitive drum 131 on which the electrostatic latent image is formed, and forms a toner image on the peripheral surface. A toner cartridge (toner supply device) 20 according to the present invention is detachably attached to the developing unit 134.

  The transport belt 135 feeds the paper P fed from the paper storage unit 15 toward the peripheral surface of the photosensitive drum 131 on which the toner image is formed, and is stretched between predetermined rollers. In the counterclockwise direction. Below the photosensitive drum 131, a transfer roller 136 is provided via a conveyance belt 135, and the sheet P sent out from the sheet storage unit 15 is rotated around the conveyance belt 135 and the photosensitive drum 131 and the transfer roller 136. The toner image formed on the peripheral surface of the photosensitive drum 131 is transferred onto the paper P.

  Residual toner remaining on the photosensitive drum 131 after the transfer process is swept away by a blade (not shown) of the cleaning device 137 in accordance with the rotation of the photosensitive drum 131, and the peripheral surface of the cleaned photosensitive drum 131 is Again, it goes to the charging unit 132 to form a new image.

  The fixing unit 14 fixes the transfer image on the paper P formed by transferring the toner image on the photosensitive drum 131 by the image forming unit 13 by heat treatment, and heat heated to a predetermined temperature. A roller 141 and a pressure roller 142 disposed opposite to the heat roller 141 are provided.

  The sheet P fed from the image forming unit 13 to the fixing unit 14 by the driving of the conveying belt 135 passes between the heat roller 141 and the pressure roller 142 so that the transfer image is subjected to fixing processing. The paper is discharged from a device main body 11 to a paper discharge tray 19 projecting outward through a pair of discharge rollers 17 and a paper discharge port 18 opened in the side wall 111 of the device main body 11.

FIG. 2 is a perspective view showing the cartridge body 30 before the cover 70 is mounted in the toner cartridge 20 according to the embodiment of the present invention, and FIG. 3 is a plan view thereof. 4 is a cross-sectional view taken along line AA in FIG. 2 and 3, the XX direction is referred to as the width direction, and the YY direction is referred to as the front-rear direction. In particular, the -X direction is leftward, the + X direction is rightward, the -Y direction is forward, and the + Y direction is forward. It is called the back. As shown in FIG. 2, the toner cartridge 20 has a basic configuration including a cartridge body 30 that is long in the width direction and has an opening on the upper surface, and a lid body 70 that closes the upper surface opening of the cartridge body 30. ing.

  The lid body 70 has the same shape in plan view as a flange portion 401 (to be described later) of the cartridge body 30, and is welded in a state where the four edge portions are covered with the cartridge body 30 so as to overlap the flange portion 401. It is designed to be fixed to the toner loading container 40. After the lid 70 is welded to the cartridge body 30, toner is loaded into the toner cartridge 20.

  The cartridge main body 30 stores and stirs the toner to be supplied to the developing unit 134 (FIG. 1), and has a toner loading container 40 that is long in the width direction with its upper surface opened, and is internally provided in the toner loading container 40. The agitation member 50 for agitating the toner that has been agitated, and a conveying member 60 for conveying the toner agitated by the agitation member 50 are provided.

  The toner loading container 40 includes a front wall 41 that is long in the width direction, a rear wall 42 that faces the front wall 41, and a left wall 43 that is laid between the front wall 41 and the left edge of the rear wall 42. It consists of a right side wall 44 constructed between the right end edges and a bottom plate 45 (FIG. 4) constructed between the lower edges of each of the walls 41, 42, 43, 44. An annular flange 401 projecting outward is formed at the upper surface opening of the toner loading container 40.

  Further, the left and right side walls 43, 44 are respectively formed in the same shape with a two-protrusion that protrudes downward, and the first arc side wall (the left first arc side wall 431 and the right first arc side wall 441) is formed in the front nodule portion. Are formed, and second arcuate side walls (left second arcuate side wall 432 and right second arcuate side wall 442) are formed in the rear knob portion.

  The first arcuate side walls 431 and 441 have a radius of curvature larger than the curvature radius of the second arcuate side walls 432 and 442, and a toner agitating space 46 that agitates the toner between the first arcuate side walls 431 and 441 facing each other. A toner conveying space 47 is formed between the second arcuate side walls 432 and 442 that are formed and are opposed to each other.

  In the present embodiment, the bottom plate 45 (first arc bottom plate (arc-shaped bottom) 451) (FIG. 4) of the toner stirring space 46 has an arc shape so that the cross-sectional shape follows the arc shape of the first arc side walls 431 and 441. In addition, the bottom plate 45 (second arc bottom plate 452) of the toner conveyance space 47 is similarly set in an arc shape. However, in the present invention, the first arc bottom plate 451 and the second arc bottom plate 452 are completely formed. The shape is not limited to a circular arc shape, and may be slightly deviated from a complete arc shape such as an elliptical shape, a substantially rectangular shape, or a polygonal shape.

  The lowest level of the first arc bottom plate 451 is positioned below the lowest level of the second arc bottom plate 452. Further, a partition wall 48 is provided between the toner stirring space 46 and the toner transport space 47, and the toner stirred by the stirring member 50 in the toner stirring space 46 gets over the partition wall 48 and passes through the toner transport space 47. To be supplied.

  The right first arc side wall 441 is provided with a mounting groove 443 formed by being recessed from the center of curvature on the inner surface side toward the upper flange portion 401. The mounting groove 443 is set so that the groove width dimension is slightly larger than the diameter dimension of the stirring shaft 51 to be described later, so that the right end portion of the stirring shaft 51 can be fitted in a sliding contact state.

As shown in FIG. 4, outside the first arc bottom plate 451, the toner in the toner stirring space 46 is positioned at the lowest level corresponding to a toner sweep plate (cleaning means) 55 described later on the stirring member 50. The toner sensor 80 for detecting the presence or absence of the toner is provided with the detection surface facing the outer bottom surface of the first arc bottom plate 451. In the present embodiment, a capacitance type is used as the toner sensor 80, but the toner sensor 80 is not limited to a capacitance type, and any toner can be used as long as it can detect the presence or absence of a detection target. Any thing may be adopted.

  Hereinafter, the stirring member 50 will be described based on FIG. 5 with reference to FIGS. FIG. 5 is a partial perspective view showing an embodiment of the stirring member 50. The direction display by X and Y in FIG. 5 is the same as that in FIG. As shown in FIG. 5, the stirring member 50 is loaded in the toner stirring space 46, and includes a stirring shaft 51 installed between the center of curvature of the left and right first arc side walls 431 and 441 (FIG. 2). , A plurality of connecting fins (intermediate members) 52 integrally formed with the stirring shaft 51, and a long support plate fixed to the tip of the plurality of connecting fins 52 so as to be parallel to the stirring shaft 51. (Intermediate member) 53, a stirring blade 54 integrally supported by the support plate 53, and a toner sweeping plate (sweeping force enhancing portion) 55 formed by a part of the stirring blade 54. Has been.

  The stirring shaft 51 has a length dimension slightly longer than the dimension between the left and right first circular arc side walls 431 and 441, and the left end is formed at the center of curvature of the left first circular arc side wall 431. The right end of the stirrer 50 is fitted in the mounting groove 443 provided in the right first arc side wall 441, so that the stirrer 50 can be connected to the stirrer shaft 51. The toner agitating space 46 is mounted so as to rotate integrally therewith.

  In the present embodiment, the support plate 53 employs two pieces of a left support plate 531 and a right support plate 532 having substantially the same length, and the agitating blade 54 fixed to the support plate 53 by this is also used. Two sheets of a left stirring blade 541 that is necessarily fixed to the left support plate 531 and a right stirring blade 542 that is fixed to the right support plate 532 are employed. The left support plate 531 is provided on the left portion of the stirring shaft 51, while the right support plate 532 is provided on the right portion of the stirring shaft 51, and the respective edges overlap each other at the central portion of the stirring shaft 51. It is said that.

  Further, the left support plate 531 and the right support plate 532 in the support plate 53 are provided at point-symmetrical positions around the axis of the stirring shaft 51 with the connecting fins 52 interposed therebetween, whereby the left stirring blade 541 and the right stirring plate 532 are provided. The blade 542 is in a state of being provided at a point symmetrical position with respect to the axis of the stirring shaft 51. Further, the stirring blade 54 is provided with a predetermined number of toner passage holes 543 having a rectangular shape for allowing the toner being stirred to pass therethrough.

  The stirrer blade 54 is dimensioned so that its tip edge comes into contact with the inner circumferential surface of the first arc bottom plate 451 in a slightly bent state. Therefore, when the stirring shaft 51 rotates counterclockwise in FIG. 4 around the shaft center, the stirring blade 54 rotates while contacting the inner circumferential surface of the curvature of the first arc bottom plate 451, thereby causing the toner stirring space 46 to move. The toner is agitated.

  The toner sweep plate 55 is defined by two cut lines (cuts) 559 having a predetermined size in which a portion of the stirring blade 54 corresponding to the toner sensor 80 is cut in the axial direction of the stirring shaft 51. Is formed.

  The toner sweeping plate 55 is set so that the protruding amount from the support plate 53 is slightly larger than the protruding amount of the stirring blade 54. In other words, the toner sweep plate 55 is elastically deformed in a state where the stirring member 50 is mounted in the toner stirring space 46 and the leading edge of the toner sweep plate 55 is in contact with the inner circumferential surface of the first arc bottom plate 451. The amount is larger than the amount of elastic deformation of the stirring blade 54, so that the toner sweeping force of the toner sweeping plate 55 is stronger than that of the stirring blade 54.

Therefore, when the stirring member 50 is rotated around the stirring shaft 51 in a state where the toner in the toner stirring space 46 is low, as shown in FIG. 6, the leading edge of the stirring blade 54 and the first arc bottom plate 451 With a slight amount of toner in between, the toner sweep plate 55 strongly sweeps the toner and the edge of the tip directly contacts the inner circumferential surface of the curvature of the first arc bottom plate 451. The detection surface of the toner sensor 80 can face the toner stirring space 46 without being blocked by the toner via the first arc bottom plate 451.

  In this embodiment, the stirring blade 54 and the toner sweep plate 55 are formed of a tough synthetic resin material having excellent flexibility and elasticity, such as a polyethylene film such as PET (polyethylene terephthalate) or a polypropylene film. As a result, the toner can be reliably stirred.

  In the present embodiment, a pair of projecting support pieces (support projecting pieces) 533 for supporting the base end side of the toner sweeping plate 55 on the support plate 53 is provided. Each protruding support piece 533 is provided on the back side in the rotational direction of the toner sweeping plate 55 in a state where the protruding amount from the support plate 53 is set to approximately half of the protruding amount of the toner sweeping plate 55. The toner sweep plate 55 is not elastically deformed on the base end side due to the presence of the protruding support piece 533, and accordingly, the amount of elastic deformation (that is, the amount of bending angle) on the front end side increases and the elastic force increases. In addition, the toner sweeping power increases.

  In the stirring member 50 configured in this manner, the rotation of the drive shaft of the drive motor (not shown) is transmitted to the stirring shaft 51 via the joint member 433 (FIG. 2) provided on the outer surface side of the left first circular arc side wall 431. As a result, the stirring blade 54 and the toner sweeping plate 55 rotate integrally around the stirring shaft 51.

  The transport member 60 is for driving the stirrer 50 to transport the toner transferred from the toner stirring space 46 over the partition wall 48 to the toner transport space 47 and supplying it to the developing unit 134. FIG. As shown in the figure, a screw shaft 61 is provided between the second arcuate side walls 432 and 442 in the toner conveyance space 47, and a helical screw blade 62 formed on the outer peripheral surface of the screw shaft 61. ing.

  2 and 3, the screw blade 62 includes a left screw blade 621 formed from a position (neutral position 63) slightly to the right of the center in the width direction to the left end, and the neutral position. 63 and a right screw blade 622 formed from the right end portion to the right end portion. The left screw blade 621 and the right screw blade 622 are so-called reverse spirals in which the spiral directions are reversed, and when the left and right screw blades 621 and 622 rotate around the screw shaft 61 in a predetermined direction, toner conveyance is performed. The toner in the space 47 is conveyed from the left and right toward the neutral position 63.

  The left end portion of the screw shaft 61 passes through the center of curvature of the left second circular arc side wall 432 and protrudes to the outside, and the conveying member side gear 64 is attached to the protruding portion so as to be integrally rotatable. Further, the joint member 433 (FIG. 2) is integrally provided with a stirring member side gear 56 concentrically, and the stirring member side gear 56 meshes with the transport member side gear 64, whereby the joint member 433 rotates. (That is, the rotation of the stirring member 50) is transmitted to the conveying member 60 via the stirring member side gear 56 and the conveying member side gear 64.

  On the other hand, as shown in FIG. 4, the second arc bottom plate 452 at the bottom of the toner transport space 47 is directed with a lead-out hole 453 that penetrates downward and leads out the toner. A gate member 454 that can be opened and closed is provided on the outer surface side of the second arc bottom plate 452 so as to correspond to 453. By opening a gate (not shown) of the gate member 454, the toner in the toner transport space 47 is transferred to the developing unit. 134 (FIG. 1).

  According to the toner cartridge 20 configured as described above, with the toner cartridge 20 mounted on the developing unit 134 as shown in FIG. 1, the stirring shaft is driven via the joint member 433 by driving of a drive motor (not shown). When 51 is rotated in the counterclockwise direction in FIG. 4, the stirring blade 54 rotates integrally around the stirring shaft 51 in the counterclockwise direction, whereby the toner in the toner stirring space 46 is partially stirred while being stirred. It moves over the partition wall 48 and moves to the toner conveyance space 47.

  On the other hand, the stirring member 50 is rotated by being transmitted to the screw shaft 61 via the stirring member side gear 56 and the conveying member side gear 64. The toner that has moved to the toner conveyance space 47 by the rotation of the screw blades 62 moves from the left and right toward the neutral position 63 and is supplied to the developing unit 134 via the outlet hole 453 and the gate member 454.

  In the present invention, since the toner sweep plate 55 is provided on the stirring shaft 51 of the stirring member 50 via the connecting fin 52 and the support plate 53, the presence or absence of toner in the toner stirring space 46 is determined by the toner sensor 80. It can be detected properly.

  The operation of the present invention will be described below with reference to FIG. FIG. 6 is a perspective view for explaining the operation of the toner sweep plate 55 and shows a state in which the remaining amount of toner T in the toner stirring space 46 has become small. Note that the direction display by X and Y in FIG. 6 is the same as in FIG.

  First, when the toner T is abundant in the toner stirring space 46 of the toner loading container 40, the stirring blade 54 and the toner sweep plate 55 are buried in the abundant toner T. Even if the toner sweep plate 55 sweeps the toner T on the inner circumferential surface of the curvature of the first arc bottom plate 451, the surrounding surface of the toner T is immediately pushed to the swept portion. Although the toner T is not covered with the toner T for a moment via the one arc bottom plate 451, it is immediately covered with the toner T. Therefore, since the detection signal of the toner sensor 80 is a pulse signal having a predetermined cycle, it can be determined that the toner stirring space 46 is filled with the toner T by this pulse-shaped detection signal.

  On the other hand, as shown in FIG. 6, when the remaining amount of toner T in the toner stirring space 46 becomes small, the stirring blade 54 has a protruding amount from the support plate 53 smaller than that of the toner sweeping plate 55, so that stirring is performed. Since the elastic force of the blade 54 is smaller than that of the toner sweep plate 55 having a large amount of deformation, the toner T has a predetermined thickness dimension between the tip edge of the stirring blade 54 and the inner circumferential surface of the first arc bottom plate 451. The first arc facing the toner sweep plate 55 set so that the protruding amount from the support plate 53 is large and the elastic force is increased due to the presence of the protruding support piece 533. The toner T positioned on the opposite surface of the bottom plate 451 is strongly swept away by the leading edge of the toner sweep plate 55.

  As a result, a portion where no belt-like toner T is present appears at the position of the first arc bottom plate 451 facing the toner sensor 80 as shown in FIG. Moreover, since the remaining amount of the toner T in the toner stirring space 46 is very small, the toner T around the toner sensor 80 does not sag toward the toner sensor 80, and thus the toner sensor 80 In this case, instead of the previous pulse detection signal, a toner out detection signal of the same level is output. Based on this detection signal, the toner agitation space 46 is emptied leaving some toner T. Can be determined.

As described above in detail, the toner cartridge 20 according to the present invention includes the toner loading container 40 loaded with the toner T and the stirring shaft 51 provided between the first arc side walls 431 and 441 of the toner loading container 40. The agitating member 50 for agitating the toner T by rotating the toner T, the conveying member 60 for conveying the toner T to the developing unit 134 for forming a toner image on the peripheral surface of the photosensitive drum, and the inside of the toner loading container 40. And the toner sensor 80 for detecting the presence or absence of the toner T, the toner T loaded in the toner loading container 40 is agitated by the rotation of the agitating blade 54 around the agitating shaft 51, thereby causing a nodule state. Even if there is a hardened material, it is unraveled and is sent to the developing unit 134 by driving the conveying member 60 in a uniformly distributed state. It is supplied to the developing unit 134 in the drive member 60.

  The toner loading container 40 includes a first arc bottom plate 451 whose cross-sectional shape orthogonal to the stirring shaft 51 is formed in an arc shape with the axis of the stirring shaft 51 as the center of curvature. A rectangular stirring blade 54 made of a flexible material whose edge is fixed in a state parallel to 51 and whose projection from the stirring shaft 51 is longer than the radius of curvature of the bottom of the toner loading container 40. The toner sensor 80 is provided with the detection end facing the outer surface side of the first arc bottom plate 451, and the stirring blade 54 has a portion corresponding to the toner sensor 80 to the first arc bottom plate 451. Therefore, the toner sweep plate 55 is provided with the toner sensor 80 of the first arc bottom plate 451 by the rotation of the stirring blade 54 around the stirring shaft 51. Other parts Since the toner T is swept away while pressing more strongly, the toner T in the vicinity of the toner sensor 80 can be reliably removed as compared with other portions, and the inside of the toner loading container 40 is almost empty. Nevertheless, it is possible to reliably prevent the inconvenience that the toner sensor 80 cannot detect the empty state in the toner stirring space 46 due to the small amount of toner T remaining in a layered manner.

  In addition, when the toner T 80 reaches a residual amount that does not flow into the opposite portion of the toner sensor 80 from which the toner T has been removed, the toner sensor 80 outputs a toner out detection signal. The image forming apparatus 10 temporarily performs image forming processing until the inside of the toner loading container 40 is completely emptied even after the detection signal is output. Can continue.

  In this way, the toner out detection signal of the toner sensor 80 can be used as a signal for preparing a new toner cartridge 20 for replacement, so as not to inconvenience the user. it can.

  Further, since the toner sweeping plate 55 is set so that the protruding amount from the stirring shaft 51 is larger than the other portions of the stirring blade 54, the toner sweeping plate 55 contacts the arc surface of the first arc bottom plate 451. In this state, the amount of elastic deformation becomes larger than that of the stirring blade 54, thereby pressing the first circular arc bottom plate 451 with a larger force, so that the toner T at the portion facing the toner sensor 80 can be more reliably swept away. it can. By adopting the toner sweeping plate 55 in this way, the sweeping force enhancing portion can be formed with a simple configuration in which a part of the stirring blade 54 protrudes slightly in the radial direction of the stirring shaft 51, and the component cost is reduced. This can contribute to the reduction of

  In addition, a part of the stirring blade 54 is applied to the toner sweep plate 55, and a cut line 559 is provided from both ends of the portion protruding from the stirring blade 54 toward the stirring shaft 51. It is possible to elastically deform in a state independent of the other parts of the blades 54, and accordingly, the toner T on the first arc bottom plate 451 can be reliably removed in a state along the position where the toner sensor 80 exists. it can.

In addition, since the toner sweep plate 55 is supported by a projecting piece 533 protruding from the stirring shaft 51 at the base end portion of the cut line 559, the toner sweep plate 55 is provided on the base end side of the cut. Since the portion that is elastically deformed by the protruding support piece 533 is reduced accordingly, the amount of deformation (angle) of the portion that can be elastically deformed is increased, and thereby a larger sweeping force on the first arc bottom plate 451 can be obtained. .

  Further, since the stirring blade 54 is fixed to the stirring shaft 51 through the intermediate member (the connecting fin 52 and the support plate 53), the presence of the intermediate member causes the mounting state of the stirring blade 54 to the stirring shaft 51 to be in the situation. Various selections can be made accordingly, and the versatility of the toner stirring structure can be increased.

  The present invention is not limited to the above embodiment, and includes the following contents.

  (1) In the above embodiment, the cut line 559 for partitioning from the stirring blade 54 is provided on both sides of the toner sweep plate 55. However, the cut line 559 is not essential and is not particularly provided. May be. When the cut line 559 is not present, the left and right stirring blades 54 are also pulled in due to elastic deformation caused by the tip edge portion of the toner sweep plate 55 coming into contact with the arc inner surface of the first arc bottom plate 451. It becomes possible to obtain a stronger elastic force, whereby the toner T- of the opposite portion of the toner sensor 80 can be more reliably removed.

  (2) In the above embodiment, it is possible to adjust the amount of toner remaining at which the toner sensor 80 detects the empty amount by the amount of the cutting line 559. The reason is that if the cut amount is small, the elastic force of the toner sweep plate 55 becomes large, so that it is possible to sweep away the toner T at the portion facing the toner sensor 80 in a state where the residual amount of toner T is large. On the other hand, if the cut amount is large, the elastic force of the toner sweep plate 55 is reduced by that amount, and therefore, the toner T around the toner sensor 80 cannot be removed unless the residual amount of the toner T is reduced as a whole. .

  (3) In the above embodiment, the toner sweeping plate 55 is supported by the projecting support piece 533 projecting from the support plate 53. However, in the present invention, the toner sweeping plate 55 is supported by the projecting support piece. It is not limited to be supported by 533 and may not be provided.

  (4) In the above embodiment, the thickness dimension of the toner sweep plate 55 may be made larger than the thickness dimension of the stirring blade 54, thereby increasing the elastic force due to the elastic deformation of the toner sweep plate 55. As a measure for increasing the thickness of the toner sweep plate 55, a predetermined sheet member may be laminated and adhered to the toner sweep plate 55.

  (5) In the above embodiment, the tip edge of the stirring blade 54 is in contact with the inner surface of the first arc bottom plate 451. However, in the present invention, the tip edge of the stirring blade 54 is the first arc. It is not limited to contact | abutting to the inner surface of the baseplate 451, It is not necessary to make especially contact | abut.

1 is a side sectional view illustrating an embodiment of an image forming apparatus to which a toner cartridge (toner supply device) according to the present invention is applied. FIG. 3 is a perspective view showing the cartridge body before the cover is mounted in the toner cartridge according to the embodiment of the invention. FIG. 3 is a plan view of the cartridge main body shown in FIG. 2. FIG. 4 is a sectional view taken along line AA in FIG. 3. It is a fragmentary perspective view which shows one Embodiment of a stirring member. It is a perspective view for explaining the operation of the toner sweep plate.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Image forming apparatus 11 Apparatus main body 12 Original image reading part 13 Image forming part 131 Photosensitive drum 132 Charging unit 133 Exposure unit 134 Developing unit 135 Conveying belt 136 Transfer roller 137 Cleaning device 14 Fixing part 141 Heating roller 142 Pressure roller 15 Paper Storage unit 16 Document placement unit 161 Document pressing cover 17 Discharge roller pair 18 Paper discharge port 19 Paper discharge tray 17 Cleaning device 20 Toner cartridge (toner supply device)
30 Cartridge body 40 Toner loading container 401 Flange portion 41 Front wall 42 Rear wall 43 Left side wall 431 Left first arc side wall 432 Left second arc side wall 433 Joint member 44 Right side wall 45 Bottom plate 451 First arc bottom plate (arc-shaped bottom)
452 Second circular arc bottom plate 453 Lead-out hole 454 Gate member 46 Toner stirring space 47 Toner conveyance space 48 Partition wall 50 Stirring member 51 Stirring shaft 52 Connecting fin 53 Support plate 531 Left support plate 532 Right support plate 533 Projection piece 54 Stirring blade 541 Left stirring blade 542 Right stirring blade 543 Toner passage hole 55 Toner sweep plate (cleaning means)
551 Left toner sweep plate 552 Right toner sweep plate 56 Stirring member side gear 60 Conveying member 61 Screw shaft 62 Screw blade 621 Left screw blade 622 Right screw blade 63 Neutral position 64 Conveying member side gear 70 Cover 80 Toner sensor T Toner

Claims (6)

A toner loading container, a stirring member for stirring the toner that is rotated between the opposing wall surfaces of the toner loading container, and a conveying member that conveys the toner stirred by the stirring member to supply the developing device to the developing device A toner supply device configured to be able to detect the presence or absence of toner in the toner loading container by a toner sensor provided outside the toner loading container,
The toner loading container has an arcuate bottom portion having a substantially arcuate cross-sectional shape perpendicular to the stirring axis,
The stirrer has a stirrer blade whose base end edge is fixed parallel to the stirrer shaft and whose front end edge faces the arcuate bottom,
The toner sensor is provided such that a detection end faces the arcuate bottom outside the toner loading container,
The toner supply device, wherein the agitation blade is formed with a sweeping force increasing portion having a larger toner sweeping force at the arcuate bottom than the other portion of the stirring blade at a portion corresponding to the toner sensor.   The toner supply device according to claim 1, wherein the sweeping force enhancing unit is configured such that a protruding amount of the stirring blade from the stirring shaft is set larger than that of the other part of the stirring blade.   The toner supply device according to claim 2, wherein the sweeping force increasing portion has a cut formed by cutting from both ends of the portion protruding from the stirring blade toward the stirring shaft. .   4. The toner supply device according to claim 2, wherein a base end portion of the sweeping force increasing portion is supported by a support protrusion protruding from the stirring shaft.   The toner supply device according to claim 1, wherein the stirring blade is fixed to the stirring shaft via a predetermined intermediate member. A toner sensor for detecting the presence / absence of toner in the toner loading container is provided outside the toner loading container, and a toner is used to clean the toner in the vicinity of the toner sensor installation site slightly deeper than the toner in other parts. It is characterized in that it is detected that the inside of the toner loading container is in an empty state by setting the toner sensor in a state where the toner remaining amount in the loading container has become a minute amount, and setting the toner sensor in advance to a toner out condition. Toner detection method.