Abstract:
A toner cartridge including a cartridge body for containing toner, an agitating paddle for agitating toner and a toner blocking/setting prevention member operative in cooperation with the agitating paddle for preventing toner in the cartridge body from blocking or setting is provided. The toner blocking/setting prevention member may include a contacting projection provided on an agitating wing of the agitating paddle which contacts with a delivering spiral to oscillate the same. Further, the toner blocking/setting member may include an oscillating plate which is repelled by the rotation of the agitating paddle to assist in agitating toner.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a toner cartridge applicable to an image forming apparatus such as a copying machine, a facsimile, a printer or the like. 
     2. Description of Related Art 
     A toner cartridge having a delivering spiral and an agitating paddle in its cartridge body has been proposed. In such a kind of toner cartridge, toner contained in the cartridge body is agitated by rotating the agitating paddle, so that toner blocking can be prevented. The word “toner blocking” means that toner, not agitated for a long time, sets of itself. 
     The toner agitated by the agitating paddle is delivered to an outlet port by the delivering spiral and then supplied to a developing device. 
     In the abovementioned toner cartridge, though toner in the vicinity of the agitating paddle during rotating is agitated, toner in the corners of the cartridge body and regions out of reach of the agitating paddle cannot be sufficiently agitated. Therefore, sometimes toner partly remains in the cartridge body and cannot be wholly supplied to the developing device. 
     SUMMARY OF THE INVENTION 
     A first object of the present invention is to provide a toner cartridge capable of wholly supplying toner in its cartridge body to a developing device or the like. 
     A second object of the invention is to provide a toner cartridge having a delivering spiral and an agitating paddle in its cartridge body so that toner in the cartridge body is agitated by the agitating paddle and the agitated toner is wholly delivered by the delivering spiral. 
     A third object of the present invention is to provide a toner cartridge in which toner blocking or setting in the cartridge body is prevented. 
     A toner cartridge according to the present invention includes a cartridge body for containing toner, an agitating paddle for agitating toner, and a toner blocking/setting prevention member operative in cooperation with the agitating paddle for preventing toner in the cartridge body from blocking or setting, the agitating paddle and the toner b locking/setting prevention member being. provided in the cartridge body. 
     In a toner cartridge according to an embodiment of the present invention, a delivering spiral comprises an elongated rotation shaft in the cartridge body and a spiral blade extended outward from the circumferential surface of the rotation shaft and continuously elongated in the longitudinal direction of the rotation shaft to form a spiral having a predetermined pitch; and the agitating paddle comprises an elongated rotation shaft disposed in parallel with the rotation shaft of the delivering spiral and a plurality of agitating wings protruded from the rotation shaft. The agitating wing of the agitating paddle is provided with a contacting projection which contacts with the spiral blade when the agitating paddle is rotated. The contacting projection functions as a toner blocking/setting prevention member. The contacting projection may be formed integrally with the agitating wing to constitute a part of the agitating wing. Preferably, the contacting wing has a width substantially equal to a pitch of the spiral blade. 
     With this structure, when a part of the agitating wing contacts with the spiral blade, the delivering spiral is oscillated to oscillate toner in the cartridge body, so that toner blocking can be prevented. Further, since the agitating wing contacts with the spiral blade only in a small width corresponding to a pitch, toner is prevented from being pressed against the spiral blade and setting. As a result, the amount of toner remaining in the cartridge body can be reduced. 
     The contacting projection may be provided on an arbitrary one or ones among the plurality of agitating wings. 
     With this structure, since only an arbitrary one or ones among the plurality of agitating wings contacts or contact with the spiral blade, the contacting range can be narrowed and thereby toner setting on the spiral blade can be further reduced. Furthermore, the manufacturing cost can be reduced in comparison with a case in which all of the agitating wings are provided with contacting projections respectively. 
     The abovementioned cartridge body may have a recessed section in the vicinity of one side surface thereof. In this case, the agitating paddle has two ranges in the longitudinal direction; that is, one range in which no agitating wing can be provided because of the recessed section, and the remaining range  16  in which agitating wings can be provided without interference with the recessed section. In this case, preferably, two agitating wings among the plurality of agitating wings are each provided with a contacting projection, and the two contacting projections are provided on the agitating wings within regions, each corresponding to three tenths of the whole of the range in which agitating wings can be provided, extending from each end of the range. 
     With this structure, the contact portions between the agitating wings and the spiral blade are limited to two potions capable of intensely oscillating the delivering spiral, so that the delivering spiral can be effectively and sufficiently oscillated. 
     In another embodiment of the present invention, a toner blocking/setting prevention member includes an oscillating plate, which is operated by the agitating paddle so as to assist in agitating toner. With this structure, since the oscillating plate assists in agitating toner in the cartridge body, stable toner supply can be achieved. 
     Where the cartridge body includes a region out of reach of the agitating effect of the agitating paddle, it is preferable to provide an oscillating plate in that region. Thereby, toner blocking can be prevented. As a result, the amount of toner remaining in the cartridge body can be reduced. 
     The abovementioned oscillating plate may comprise an elastic and flexible (preferably long) thin plate and be fixed in the curved state to the cartridge body at its both ends. With this structure, the oscillating plate, being in the curved state, is provided with repelling force, and therefore, its agitating effect can be increased. 
     Where the cartridge body has a top plate, the oscillating plate may be fixed to the top plate. With this structure, only by attaching the top plate having the oscillating plate fixed thereto, to a container section of the cartridge body, the oscillating plate can be easily disposed in the cartridge body. Accordingly, error in assembling the parts can be decreased. 
     The oscillating plate may be positioned in such a manner that the agitating paddle during rotating can repel the oscillating plate and the repelled oscillating plate can agitate toner. With this structure, the oscillating plate can be operated using the rotation of the agitating paddle. Therefore, with the simple structure, toner in the cartridge body can be effectively and sufficiently agitated. 
     The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of embodiments of the present invention given with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view, seen obliquely from an upper position, of a toner cartridge of an embodiment according to the present invention. 
     FIG. 2 is a plan view, seen from the right upper position, of the toner cartridge with a top plate detached therefrom 
     FIG. 3 is a perspective view, seen obliquely from an upper position, of an agitating paddle. 
     FIG  4 A is a sectional view taken along the line A—A in FIG.  2 . FIG. 4B is a sectional view taken along the line B—B in FIG.  2 . 
     FIGS. 5A and 5B are plan views showing an example of attachment of an oscillating plate to a top plate provided in a toner cartridge of another embodiment of the present invention. 
     FIG. 6 is a sectional view of the attaching portion of the oscillating plate taken along the line VI—VI in FIG.  5 A. 
     FIGS.  7 ( a )- 7 ( d ) are side views for explaining toner agitating operation of the oscillating plate. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1 is a perspective view, seen obliquely from an upper position, of a toner cartridge  1  according to an embodiment of the present invention. The toner cartridge  1  is constructed to supply toner. The toner cartridge  1  is, for example, loaded in a developing device in an image forming apparatus such as a copying machine and is used for supplying toner to the developing device at need. 
     The toner cartridge  1  comprises a cartridge body  23  for containing toner therein. The cartridge body  23  comprises a box-shaped container  2  with its upper surface opened and a top plate  14 , and is provided with a recessed section in the vicinity of one side surface  2   b  (on the left back side in FIG.  1 ). The top plate  14  is fitted with the container  2  from upward so as to cover the upper opening of the container  2 . The top plate  14 , which is slightly larger in size than the upper opening of the container  2 , is opposed to the upper opening. On the bottom surface of the container  2 , an outlet portion  3  for allowing toner in the cartridge body  23  to fall into the developing device is provided, for example, in the vicinity of the side surface  2   b . An outlet port  3   a  is provided in the upper surface of the outlet portion  3  so as to be communicated with an opening provided in the bottom of the container  2 . 
     The toner cartridge  1  is loaded into the image forming apparatus in the direction toward the right back in FIG.  1 . When the image forming apparatus loaded with the toner cartridge  1  is operated, toner in the cartridge body  23  is delivered to the outlet portion  3  and falls into the developing device. 
     FIG. 2 is a plan view, seen from the right upper position, of the toner cartridge  1  with the top plate  14  detached therefrom. FIG. 3 is a perspective view, seen obliquely from an upper position, of an agitating paddle  5 . In the container  2  of the toner cartridge  1 , a delivering spiral  4  for delivering toner contained in the container  2  and an agitating paddle  5  for agitating toner are provided in such a manner that they are elongated in parallel with each other. 
     The delivering spiral  4  includes a rotation shaft  6 . The rotation shaft  6  is formed in a long cylindrical shape elongated from one side surface  2   a  to the other side surface  2   b  of the container  2 . A spiral blade  7  for delivering toner in the container  2  toward the outlet port  3   a  is extended outward from and along the circumferential surface of the rotation shaft  6  of the delivering spiral  4 . The spiral blade  7  is continuously elongated in the longitudinal direction of the rotation shaft  6  to form a spiral having a predetermined pitch. 
     The agitating paddle  5  includes a rotation shaft  8 . Similarly to the rotation shaft  6  of the delivering spiral  4 , the rotation shaft  8  of the agitating paddle  5  is formed in a long cylindrical shape elongated from one side surface  2   a  to the other side surface  2   b  of the container  2 . In this embodiment, the outer shape of the rotation shaft  6  of the delivering spiral  4  is substantially the same as that of the rotation shaft  8  of the agitating paddle  5 . A plurality of agitating wings  9  for agitating toner in the container  2  protrude from the circumferential surface of the rotation shaft  8  of the agitating paddle  5 . The agitating wings  9  are arranged adjacent to one another in order in the longitudinal direction of the rotation shaft  8 . 
     The container  2  has a recessed section in the vicinity of the side surface  2   b , and in the vicinity of this recessed section, there is a region in which no agitating wing can be provided. Therefore, the agitating paddle  5  has two ranges in the longitudinal direction; that is, one range  15  in the vicinity of one end thereof on the side surface  2   b  side in which no agitating wing can be provided, and the remaining range  16  in which agitating wings can be provided. It is possible to provide a spiral blade  7  on the circumferential surface of the rotation shaft  8  in the range  15  in which no agitating wing can be provided. By providing the spiral blade  7 , toner in the vicinity of the range in which no agitating wing can be provided can be delivered. 
     In this embodiment, six agitating wings  9 , constituted by three pairs, are provided. A pair of agitating wings  9  are opposed to each other with an angle of 180° therebetween, and three pairs of agitating wings  9  are disposed with an angle of 60° between one another when seen in a section crossing the rotation shaft  8 . Each agitating wing  9  comprises a supporting arm  10  and a blade  11  supported by the supporting arm  10 . The supporting arm  10  comprises two leg portions  17  and a connecting portion  18 , and each end of the connecting portion  18  is connected to one end of each leg portion  17 . The other end of each leg portion  17  is connected to the circumferential surface of the rotation shaft  8  in such a manner that each leg portion  17  protrudes vertically from the circumferential surface. Each blade  11  is formed of, for example, a thin plate, and has a width substantially equal to the length of the connecting portion  18 . One side of the blade  11  is connected to the connecting portion  18  of the supporting arm  10  with a predetermined angle therebetween, so that the blade  11  is held with a predetermined space from the circumferential surface of the rotation shaft  8 . Accordingly, when the agitating paddle  5  is rotated to agitate toner in the container  2 , toner is prevented from accumulating and setting between the rotation shaft  8  and the agitating wing  9 . 
     Further, among the six agitating wings  9 , for example, the second agitating wing  9  counted from the side surface  2   a  side and the first agitating wing  9  counted from the side surface  2   b  side are each provided with a contacting projection  12  so that the agitating wings  9  contact with the spiral blade  7  of the delivering spiral  4 . The contacting projection  12  is in the shape of, for example, a thin plate integrally formed on the head side of the blade  11  and having a width substantially equal to a pitch of the spiral blade  7 . The contacting projections  12  are provided on the agitating wings  9  within ranges  17 , each corresponding to three tenths of the whole of the range  16  in which agitating wings can be provided, and extending from each end of the range  16 . By the rotation of the agitating paddle  5 , the contacting projections  12  contact with the delivering spiral  4 . 
     When the agitating wings  9  contact with the spiral blade  7 , the delivering spiral  4  is oscillated to cause toner in the container  2  to be oscillated. As a result, toner blocking, which means that toner, not agitated for along time, sets of itself, can be prevented. 
     Further, tunnel phenomenon, in which toner only in the vicinity of the delivering spiral  4  is delivered by rotating the delivering spiral  4  with toner in the blocking state, can also be prevented. Furthermore, since the agitating wings  9  contact with the spiral blade  7  only at two portions and each in a small width corresponding to a pitch, toner is prevented from being pressed against the spiral blade  7  and setting. 
     The abovementioned members constituting the agitating paddle  5  may be integrally formed of, for example, a rather rigid polypropylene synthetic resin. However, the shape, number and material of the agitating wings  9  are not limited to those mentioned above. Further, the position and number of the contacting projections  12  are not limited to those mentioned above, but only one contacting projection  12  may be provided on an agitating wing  9  in the vicinity of the middle portion of the agitating paddle  5 , or every agitating wing  9  may be provided with a contacting projection  12 . 
     In the bottom surface of the container  2  below the two agitating wings  9  each provided with the contacting projection  12 , recessed portions  13  are formed in correspondence with the contacting projections  12 . The width of the recessed potion  13  is substantially equal to that of the contacting projection  12 . 
     FIG. 4A is a sectional view taken along the line A—A in FIG.  2 . While the agitating paddle  5  is rotated, the head edge of the agitating wing  9  having no contacting projection  12  thereon does not contact with the spiral blade  7  but slidably contacts with the inner bottom surface of the container  2 . Thereby, toner can be prevented from being accumulated in the bottom of the container  2 . 
     FIG. 4B is a sectional view taken along the line B—B in FIG.  2 . When the agitating paddle  5  is rotated, the contacting projection  12  provided on the agitating wing  9  contacts with the spiral blade  7  of the delivering spiral  4 . Further, the head edge of the contacting projection  12  slidably contacts with the inner surface of the recessed portion  13  in the container  2  in order to prevent toner from being accumulated in the bottom of the container  2 . Accordingly, the recessed portion  13  has a shape projecting outwardly from the bottom of the container  2 . 
     Now, another embodiment of the present invention will be described in the following with reference to FIGS. 1 to  3  again. 
     In this embodiment, as shown in FIGS. 5A and 5B, an oscillating plate  19  for assisting in agitating toner is provided instead of or in addition to the abovementioned contacting projections  12  in order to prevent toner blocking or setting. 
     Specifically, though the spiral blade  7  is provided in the range  15  in which no agitating wing  9  of the agitating paddle  5  can be provided, toner in this range  15  is sometimes insufficiently agitated because of lack of agitating wings  9 . Therefore, the oscillating plate  19  is provided in this range  15  in which no agitating wing  9  can be provided. 
     The oscillating plate  19  is so located as to be in contact with a part of the agitating wing  9  nearest to the side surface  2   b . When the agitating paddle  5  is rotated, the agitating wing  9  repels the oscillating plate  19 , so that the repelled oscillating plate  19  agitates toner. The oscillating plate  19  can agitates toner in the region in which agitating effect of the agitating paddle  5  cannot reach, thereby preventing toner blocking or preventing that toner, not agitated for a long time, sets of itself. 
     As shown in FIGS. 5A and 5B, the oscillating plate  19  is attached to the top plate  14 . The oscillating plate  19  is a long thin plate formed of, for example, a polyethylene terephthalate synthetic resin, and has elasticity and flexibility. The oscillating plate  19  is attached to apart, in the vicinity of the recessed section, of the lower surface of the top plate  14 . FIG. 5A is a plan view showing the oscillating plate  19 , in which only one end of the oscillating plate  19  is attached to the lower surface of the top plate  14 . FIG. 5B is a plan view showing the oscillating plate  19 , in which the oscillating plate  19  is curved from the state shown in FIG. 5 A and the other end thereof is also attached to the lower surface of the top plate  14 . FIG. 6 is a sectional view of the attaching portion of the oscillating plate  19  taken along the arrow VI—VI in FIG.  5 A. 
     In FIG. 5A, three projections  20   a ,  20   b ,  20   c  in this order seen from the end of the top plate  14  on the recessed section side are provided on a portion of the lower surface of the top plate  14 , to which the oscillating plate  19  is attached. Referring to FIG. 6, the projection  20   a  comprises a cylindrical body and a cylindrical head portion formed on the upper end of the body and having a somewhat larger diameter than that of the body. The projection  20   c  has a length substantially equal to that of the projection  20   a  and outer diameters somewhat larger than those of the projection  20   a , and comprises a cylindrical body and a cylindrical head portion formed on the upper end of the cartridge body and having a somewhat larger diameter than that of the cartridge body, similarly to the projection  20   a . The projection  20   b  is in the shape of a cylinder substantially equal to the cylindrical body of the projection  20   a  and has no head portion. 
     In one end portion of the oscillating plate  19 , three fitting holes  21   a ,  21   b ,  21   c  for fitting the projections  20   a ,  20   b ,  20   c  respectively thereinto are provided. Referring to an enlarged view of the projection  20   a  and its circumference in FIG. 5A, the fitting hole  21   a  comprises a circular hole somewhat larger than the cross section of the cylindrical body of the projection  20   a  and somewhat smaller than the cross section of the head portion of the projection  20   a , and four semicircular holes defined on the periphery of the circular hole spaced from one another with an angle of 90° therebetween. When fitting the projection  20   a  into the fitting hole  21   a , the fitting hole  21   a  is pressed against the projection  20   a  to elastically deform the periphery of the fitting hole  21   a , so that the head potion and next the cylindrical cartridge body of the projection  20   a  pass through the fitting hole  21   a . The fitting hole  21   c  is somewhat larger than the fitting hole  21   a . The projection  20   c  is fitted into the fitting hole  21   c  by pressing the fitting hole  21   c  against the projection  20   c , similarly to the case of the fitting hole  21   a . The fitting hole  21   b  is a circular hole somewhat larger than the cross section of the projection  20   b , and the projection  20   b  is fitted into the fitting hole  21   b.    
     In the other end portion of the oscillating plate  19 , fitting holes  24   a ,  24   b ,  24   c  having the same shapes as those of the fitting holes  21   a ,  21   b  and  21   c  respectively are provided. The oscillating plate  19  is curved in the vicinity of the middle portion of the length thereof, and the projections  20   a ,  20   b ,  20   c  are fitted into the fitting holes  24   a ,  24   b ,  24   c  respectively similarly to the fitting holes  21   a ,  21   b ,  21   c . By curving the oscillating plate  19 , repelling force is given to the oscillating plate  19 , so that agitating effect can be increased. 
     The head portions on the upper ends of the projections  20   a ,  20   c  are provided so as to prevent the projections  20   a ,  20   c  from being detached out of the fitting holes  24   a ,  24   c  when the oscillating plate  19  tends to return, by its elasticity, from the state of FIG.5B in which the oscillating plate  19  is curved and the projections  20   a ,  20   b  are fitted to the fitting holes  24   a ,  24   c  to the state of FIG.  5 A. Further, the projection  20   b  is fitted into the fitting holes  21   b ,  24   b  so as to prevent the oscillating plate  19  from being displaced in the horizontal direction. 
     As mentioned above, in this embodiment, since the projections  20   a ,  20   b ,  20   c  are integrally formed with the lower surface of the top plate  14 , the oscillating plate  19  can be easily fitted without need of any additional member except the oscillating plate  19 . Accordingly, error in assembling the parts can be decreased. 
     The numbers and shapes of the projections  20   a ,  20   b ,  20   c , the fitting holes  21   a ,  21   b ,  21   c  and the fitting holes  24   a ,  24   b ,  24   c  are not limited to those mentioned above. Further, the method for fitting the oscillating plate  19  is not limited to that mentioned above, but the oscillating plate  19  may be directly welded to the lower surface of the top plate  14 . Further, in this embodiment, the projections  20   a ,  20   c  are provided with head portions respectively so as to prevent the oscillating plate  19  being detached. However, by forming the fitting holes  21   a ,  21   c  and the fitting holes  24   a ,  24   c  somewhat smaller than the cross sections of the projections  20   a ,  20   c  without providing head portions to the projections  20   a ,  20   c , the fitting holes  21   a ,  21   c  and the fitting holes  24   a ,  24   c  can be engaged with the projections  20   a ,  20   c  in the state in which the hole peripheries of the fitting holes  21   a ,  21   c  and the fitting holes  24   a ,  24   c  press the cylindrical bodies of the projections  20   a ,  20   c  respectively. 
     FIGS. 7 ( a )-( d ) are side views showing states of t he oscillating plate  19  agitating toner seen from the side surface  2   b  side. In FIGS.  7 ( a )-( d ), the oscillating plate  19  is disposed in the vicinity of the side surface  2   b  of the container  2  in such a manner that it is curved and pressed against a art of the inner surface of the container  2  on the front side of the toner cartridge  1  when loaded in an image forming apparatus. Therefore, toner tends to be accumulated in the vicinity of curved middle portion of the oscillating plate  19 . An opening for allowing toner to fall down therethrough may be provided near the longitudinally middle portion of the oscillating plate  19  (see FIGS.  5 A and  5 B). The shape of the opening  22  is not limited to that shown in FIGS. 5A and 5B, but may be any other shape if it allows toner to sufficiently fall down and allows the oscillating plate  19  to have repelling force enough to agitate toner. 
     In this embodiment, by the rotation of the rotation shaft  8 , the blade  11  of the agitating wing  9  nearest to the side surface  2   b  among a plurality of agitating wings  9  repels the oscillating plate  19  at every rotation thereof to operate the oscillating plate  19 . Therefore, only the operations of the agitating wing  9  nearest to the side surface  2   b  and the oscillating plate  19  will be described in the following. 
     The state of the oscillating plate  19  operated by the agitating paddle  5  will be described in order with reference to FIGS.  7 ( a ) to  7 ( d ). 
     (a) Before the agitating wing  9  contacts with the oscillating plate  19 , the oscillating plate  19  is disposed in the state supported by the rotation shaft  8  of the agitating paddle  5 . 
     (b) When the agitating wing  9  contacts with the oscillating plate  19 , the oscillating plate  19  is slidably raised by the side surface of the blade  11  of the agitating wing  9 . 
     (c) The oscillating plate  19  is raised to the highest position by the head side of the blade  11 . 
     (d) The agitating wing  9  and the oscillating plate  19  separate from each other, and the oscillating plate  19  returns to the original position by the elasticity thereof. Then the operations (a) to (d) are repeated. 
     Further, since the oscillating plate  19  is fitted in somewhat twisted state as shown in FIGS.  7 ( a )-( d ), it, when operated, generates a complicated locus, unlike a linear reciprocating movement of an oscillating plate in the form of a thin plate only one end of which is fitted to the lower surface of the top plate  14 . In concrete, the oscillating plate  19  is raised with being displaced gradually toward the side surface  2   b , and after the oscillating plate  19  is separated from the agitating wing  9 , the oscillating plate  19  returns gradually toward the side surface  2   a  side to reach the original position. 
     By the abovementioned series of movements of the oscillating plate  19 , toner in the region of the cartridge body  23  in which no agitating wing can be provided can be sufficiently agitated. Consequently, toner blocking in this region can be prevented, and toner can be wholly delivered. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims. 
     This application corresponds to the Japanese Patent Applications No.2000-156544 and No.2000-156545 filed in the Japan Patent office on May 26, 2000, and the whole disclosures of these Japanese applications are incorporated herein by