Abstract:
A toner container for use in an image forming apparatus to discharge toner from the toner container upon rotation of the toner container in the image forming apparatus along a direction of a rotation axis of the toner container has a cylindrical body unit for containing a toner; a cylindrical end portion at a first end of the toner container, the cylindrical end portion including a first end face and a second end face; a toner supply port provided in the cylindrical end portion; and a protruded portion provided on the first end face of the first end portion, the first end face being recessed from the second end surface and positioned under said toner supply port.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2003-328485, filed on Sep. 19, 2003; the entire contents of which are incorporated herein by reference. 
   BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates generally to a toner container in an image forming apparatus, and more particularly to a toner container utilized for image forming apparatuses such as a copying machine, a printer, a facsimile, etc. 
   2. Related Background Arts 
   An image forming apparatus such as a copying machine, a printer, a facsimile, etc. that deal with images, as known well, forms an image by forming an electrostatic latent image on a photosensitive drum, having a toner as a black minute powder adsorbed corresponding to the formed electrostatic latent image and transferring a visible image onto a sheet of paper, etc. 
   The toner is consumed each time the image is formed and is therefore required to be properly supplied in response to a frequency of forming the image. 
   For stably supplying the toner, as disclosed in, e.g., Japanese Patent Laid-open (Unexamined) publication No.2001-228692, the image forming apparatus is provided with a toner supply device, whereby the toner contained in the toner container is supplied. 
   This toner container takes a cylindrical shape having a helical groove formed in its internal surface, and is constructed to move the toner towards a replenishment port provided at an end portion thereof as it is rotated. The toner replenishment port is formed as, for example, a circular hole in the cylindrical surface at the endmost portion of the toner container, and a shutter for opening and closing this replenishment port as it slides in the axial directions of the toner container, is provided for preventing the toner from scattering. 
   In a toner container of this configuration, the toner should be continuously supplied from the toner replenishment port by simultaneously rotating the toner container. 
   Moreover, a rotational position of the toner container should be restricted to enable the container to be inserted and taken out within a certain given range so that the toner does not spill from the toner replenishment port directed sideways or downwards. 
   The Japanese Patent Application Laid-open publication 2001-228692 discloses a toner container that has a protrusion on the surface thereof. In this toner container, in the case where the protrusion directs upward toward the copy machine main body, the toner container can be attached to or detached from the copy machine main body. 
   However, in such scheme, the posture for enabling detaching is so limited that operability is not good because sometimes the toner container must be rotated nearly 360 degrees. 
   With an increase in recently-arising demands for forming the images, it is desired that a toner containing quantity per toner container be increased in response to a request for extending a toner exchange period, so that the container is filled with the toner to the proximity to the limit. On the other hand, with a request for downsizing the image forming apparatus, an interior of the image forming apparatus adopts a dense structure that educes an extra space or makes use of the space to the greatest possible degree. 
   Under such circumstances, if the toner container is inserted and taken out in the event of a paper jam and on the occasion of maintenance other than the toner exchange, the toner might be spilled and also scattered upon receiving a wind of a cooling fan for cooling the interior of the apparatus, depending on a position for inserting and taking the container out, resulting in a problem that a contamination in the interior of the apparatus and a malfunction of a sensor are induced. 
   Further, the toner container has hitherto been sold in a fashion of being packed one by one in the form of a toner cartridge as an expendable supply. The conventional toner container, however, has projections larger than a major diameter of the container body and therefore needs a larger packing configuration and a larger package than required. This was a factor for raising costs for preservation, transportation and so on. 
   SUMMARY OF THE INVENTION 
   Accordingly, it is an object of the present invention to provide a toner container which can discharge toner from the toner replenishment port during its rotation and is superior in operability. 
   According to one aspect of the present invention, there is provided a toner container for use in an image forming apparatus to discharge toner from the toner container upon rotation of the toner container in the image forming apparatus along a direction of a rotation axis of the toner container comprising: 
   a cylindrical body unit for containing a toner; 
   a cylindrical end portion at a first end of the toner container, the cylindrical end portion including a first end face and a second end face; 
   a toner supply port provided in the cylindrical end portion; and 
   a protruded portion provided on the first end face of the first end portion, the first end face being recessed from the second end face and positioned under said toner supply port. 
   According to another aspect of the present invention, there is provided a toner container for use in an image forming apparatus to discharge toner from the toner container upon rotation of the toner container in the image forming apparatus, wherein the toner container is adapted for insertion into the image forming apparatus along a direction of a rotation axis of the toner container comprising: 
   a cylindrical body unit for containing a toner; 
   a cylindrical end portion at a first end of the toner container, the cylindrical end portion including a first end face and a second end face; 
   a toner supply port provided in the cylindrical end portion; 
   a protruded portion provided on the first end face of the first end portion, the first end face being recessed from the second end face and positioned under said toner supply port; 
   the first end face being recessed from the second end face and positioned under said toner supply port; and 
   a protrusion having a predetermined length provided in a circumferential direction of the cylindrical end portion, the maximum height of the protrusion being smaller than a main diameter of the cylindrical body; a cylindrical surface being provided on the rear side of the protrusion on the cylindrical end portion. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a sectional view showing an outline of a construction of a copying machine as an image forming apparatus for which a toner container according to the invention is used; 
       FIG. 2  is an explanatory view showing an outline of a configuration of an image processing unit for which the toner container of the present invention is used within the image forming apparatus shown in  FIG. 1 ; 
       FIG. 3  is a perspective view illustrating an external appearance of the toner container in one embodiment of the present invention; 
       FIG. 4  is a front view illustrating the external appearance of the toner container according to one embodiment of the present invention; 
       FIG. 5  is a perspective view illustrating a configuration of a bottle cap as a front portion of the toner container according to one embodiment of the present invention; 
       FIG. 6  is a sectional view showing an internal configuration of the bottle cap illustrated in  FIG. 5 ; 
       FIG. 7  is a perspective view showing an external appearance of a drive unit for rotationally driving the toner container by setting this container; 
       FIG. 8  is a sectional view showing an internal configuration of the drive unit shown in  FIG. 7 ; 
       FIG. 9  is a perspective view showing a modified example of a protruded member at a front end portion of the bottle cap; 
       FIG. 10  is a perspective view showing a modified example of the protruded member at the front end portion of the bottle cap; 
       FIG. 11  is a perspective view showing a modified example of the protruded member at the front end portion of the bottle cap; and 
       FIG. 12  is a perspective view showing a modified example of the protruded member at the front end portion of the bottle cap. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   An image forming apparatus to which an embodiment of the present invention is applied, will hereinafter be described in detail by exemplifying a copying machine. 
     FIG. 1  is a sectional view showing an overall configuration of a copying machine  1  to which a toner supplying device and a toner container according to the present invention are applied. 
   The copying machine  1  has, in addition to a paper feed cassette  2  for accommodating a multiplicity of copy sheets in a lower portion of a main body thereof, an LCF paper feed device  3  for feeding a large quantity of sheets having the same size, and a manual paper feed device  4  for manually supplying various types and various sizes of sheets. 
   An upper portion of the copying machine  1 , there is provided with an image reading unit  5  for reading an original placed on this unit  5  and an original automatic feeding device (ADF)  6  for feeding the original to this image reading unit  5 . 
   Further, a middle portion of the copying machine  1 , there is provided with an image storing unit  7  for storing image data of the image read by the image reading unit  5  and a laser optical system  9  for fetching the image data stored therein and writing an image to be printed to an image forming unit  8 . 
   A construction of the image forming unit  8  will be explained with reference to  FIG. 2  in addition to  FIG. 1 . The image forming unit  8  has a photosensitive drum  10  of which a surface is formed with an electrostatic latent image corresponding to the image data by the laser optical system, an electrification charger  13  for charging photosensitive drum  10 , a developing unit  11  for developing the electrostatic latent image by supplying a toner, a transfer charger for transferring a developed image on a photosensitive drum  16 , a de-energizing lamp  14  for de-energizing (removing the electric charge on) the surface of the photosensitive drum  10 , and a leaner  12  for cleaning the surface of the photosensitive drum. The developing unit  11  is supplied with the toner from a toner supply container (toner cartridge)  20  supported by a toner container supporting unit  17 . Note that toner container supporting unit  17  is provided with a drive unit for rotating the toner container  20  in a way that engages with this container  20 . 
     FIG. 3  is a perspective view illustrating a overall appearance of the toner container  20  according to the present invention.  FIG. 4  is a front view thereof. A cylindrical body  21  containing the toner is constructed of a plastic container taking a cylindrical shape, and, as will be explained later on, the toner container is rotated within the image forming apparatus, corresponding to a state of a toner consumption. A helical groove  22  is formed along the periphery of the toner container body  21 . This groove  22  configures a protruded wall surface on the side of an internal surface of the container body  21 , whereby the toner existing in a recessed portion between streaks of the protruded wall surface is moved towards a toner supply port as the toner container  20  rotates. 
   On a proximal side in  FIG. 3 , a bottle cap member  23  engaging with the toner supply device, for rotating the toner container  20  as a cylindrical end portion. This bottle cap member  23  is spirally coupled to the toner supply device in such a way that a thread formed on an external surface of a front end portion of the container body  21  meshes with a thread formed on an internal surface of the bottle cap member  23 . Note that the bottle cap member  23  and the container body  21  may be formed into one united body. 
     FIG. 5  shows a detailed configuration of the bottle cap member  23 .  FIG. 6  shows a vertical sectional view thereof. 
   The front end portion of the bottle cap member  23  is formed with a protruded member  24 . This protruded member  24  serves, as will be described later on, to surely firmly engage with a rotation driving mechanism of the toner supply device. 
   Referring again to  FIGS. 3 and 4 , a shutter  25  slidable in axial directions is provided on the surface of the front end portion of the bottle cap member  23 . 
     FIGS. 5 and 6  show a state where the shutter itself is detached. A slide plate  27  on which the shutter  25  slides is configured to include an overhanging member provided on a cylindrical surface of the front end portion, and a pawl extending downwards of a side end portion of the shutter  25  engages with this overhanging member. A toner supply port (hole)  31  for supplying the toner is formed in a position, proximal to the front end portion of the bottle cap member, of the slide plate  27 . A slight recess  28  is formed in such a direction as to get away from the front end portion of the slide plate  27 . This recess  28  serves for stable positioning of a shutter front end portion  25   a  when the shutter  25  is in a fixed position to cover the toner supply port  31 . Then, when the shutter  25  opens, the shutter front end portion  25   a  moves upwards along an inclined surface  29  and comes to arrive at on a stable surface  30  formed as a flat surface. 
   The engaging side of the bottle cap member  23  with the container body  21  has the largest diameter throughout within the bottle cap, and a protrusion  26  is formed in a part thereof. For this protrusion, detailed description will be made later. A length of this protrusion  26  extends over only a part of the circumference, and its height at the front end portion does not exceed a major diameter of the container body. The protrusion  26  has several reinforcing plates  26   a  against a force applied when a micro-switch, etc. engages therewith. 
   Next, a structure of the internal surface of the bottle cap  13  will be explained. 
   The internal surface closer to the front end side than the protrusion  26  is formed with a thread  33  engaging with a thread helically formed at the front end portion of the toner container. A discontinuous formation of this thread  33  serves to facilitate removing the toner at a connecting portion. Note that these threads are formed as reversing screws in order that the bottle cap will not come off due to the rotations. 
   An outward portion of the protruded portion  24  of the front end portion is provided with a recessed portion  35  sank well deeper than a reference end surface  34  of the bottle cap  23 , and hence a substantial length of the protruded member  24  increases. By contrast, an internal surface of this recessed portion  35  is formed as an internal-surface-sided protruded portion  36  reversely protruding large. In this configuration, the toner conveyed along the helical wall surface gets on a peripheral surface  36   a  of the internal-surface-sided protruded portion  36  and, a distance from this position up to the toner supply port being short, stably conveyed from the toner supply port  31 , thereby stabilizing the toner supply. 
   Note that it is recommended as for a size of the protruded member  24  that a total sectional areal size of the protruded member be equal to or larger than 30% and desirably equal to or larger than 50% in the case of assuming a circle having a radius of 1 cm. 
     FIG. 7  is a perspective view of a drive unit  40  that engages with and thus rotating the bottle cap member described above.  FIG. 8  is a sectional view of the drive unit  40 . Provided on the left side in  FIG. 8  is a gear box  43  having a plurality of gears rotationally driven by a motor (not illustrated). 
   The bottle cap  23  is inserted from an inlet area  41 , however, because of restriction members  42   a ,  42   b ,  42   c  provided respectively at lower, left and right portions, in a case where the protrusion  26  faces in a fixed direction, i.e., if the center of the toner supply port  31  or of the protrusion  26  falls within a range of ±45° on the basis of the perpendicular direction with respect to a central axis of the toner container, the toner container can be attached and detached. These functions enable an effective prevention of a scatter of the toner from the toner supply port  31  when the toner container is attached and detached. 
   Further, the protruded member  24  described above is filled with a resinous material and therefore has advantages, wherein this member  24  exhibits a large strength on the occasion of engaging with a drive shaft, and an accident of being damaged due to the recessed structure adopted by the prior art, is hard to occur. 
   Thus, the protrusion  26  utilized for only detecting the genuine toner and the agitated state of the toner, is also used as a restriction guide for the positions of inserting and removing the container. Hence, a length requirement for the circumference of the protrusion  26  is that it be a length not interfering with the attaching/detaching restriction members  42   a  through  42   c  on the side of the drive unit when attached and detached in the normal positions. 
   Moreover, according to this embodiment, a rear side of the protrusion  26  has a cylindrical surface  32  that is large in width. This cylindrical surface is a cylindrical surface that is smaller in its major diameter than the cylindrical surface of the toner container body  21 . 
   The reason why this configuration is adopted is that the surface positioned opposite to the toner replenishment port remains as the sufficiently wide cylindrical surface to form a clearance with respect to the guide width of the opposite member so that the protrusion  26  can perform the sure restriction by interfering with the attaching/detaching restriction members beyond the above range of the angle. The width of this cylindrical surface may be a size large enough not to hinder the interfering motion of the protrusion  26  with the attaching/detaching restriction members and, it is desirable, be normally equal to or greater than twice the width (in the axial directions) of the protrusion and preferably be equal to or greater than three times. 
   Further, the provision of this cylindrical surface makes it feasible to grasp the toner container by catching the lower part of the protrusion with a hand on the occasion of encasing the toner container  20  vertically into a package or taking it out of this package, thus improving a stability of handling with the toner container. 
   As discussed above, according to this embodiment, the protrusion used for only detecting the genuine toner and the toner rotating operation is made to function also as the restriction member for restricting in order to prevent the toner from scattering when attached and detached. 
   Furthermore, with a downsize of the image forming apparatus, some have such a contrivance that the protrusion detecting switch is provided on the side of the rotation driving device for the toner container existing inside the apparatus. For applying to these apparatuses, according to this embodiment, the protrusion  26  is provided closer to of the toner supply port than a half of the total length of the container. 
   On the other hand, the protruded member  24  for driving the bottle cap  23  needs engaging with a guide  44  of the drive shaft within the drive unit  40 . According to this embodiment, however, the periphery of the protruded member  24  is formed with the recessed portion  35  sank deeper than the reference end surface, and hence the substantial height of the protruded member  24  increases, thereby making it possible to ensure the sufficient engagement with the drive shaft guide  44 . 
   Moreover, a diameter of the front end portion of the protrusion  26  is set smaller than the major diameter of the container body  11 , and therefore the maximum diameter is a diameter of the container body  11 . This implies a reduction in capacity required for packing, transporting and stocking the toner container, and it follows that costs therefor decrease. 
     FIGS. 9 to 12  inclusive are perspective views showing modified examples in which the shape of the protruded member  24  illustrated in  FIG. 5  is changed. 
     FIG. 9  shows that the flat surface of the protruded member is formed in a square shape. The configuration is not, however, limited to this and may involve using triangular or more polygonal shapes. The purpose is accomplished if capable of transmitting the rotational driving force in a way that engages with the drive shaft, and hence whatever polygonal shapes can be used without being limited to neat shapes such as a regular polygon. 
   In  FIGS. 10 and 11 , a cross shape is adopted. As compared with the normal cross shape in  FIG. 10 ,  FIG. 11  illustrates a shape configured by removing the intersection from the cross shape. In these cases, lengths, etc. of the respective bar segments configuring the cross shape may arbitrarily be selected. 
     FIG. 12  shows a circular shape for the protruded member. In this case, however, the rotation can not be transferred, so that the toner container can be rotated by engaging with, for example, a protruded portion  55  formed rectilinearly in parallel with the axial directions on a side surface of the bottle cap. 
   The embodiment discussed above adopts the structure of enabling the container body and the bottle cap to be separated, however, the container body and the bottle cap may also be formed by integral molding. 
   In a toner contained according to an embodiment of the present invention, a periphery of a protruded member provided at a front portion is recessed, a height of this protruded member is substantially large, and therefore an engagement with a drive shaft is surely performed when the toner container is set in an image forming apparatus and then rotationally driven. Besides, this recessed portion has a cylindrical surface formed just under a toner supply port within the toner container, thereby stably supplying the toner. 
   Moreover, in the toner container according to the embodiment of the present invention, a protrusion for restricting attaching/detaching in a way that interferes with an attaching/detaching restriction member in a rotation mechanism at such a rotational angle that the toner might be scattered from the toner supply port when set in the image forming apparatus, is formed on a peripheral surface that is closer to rear end than a shutter mechanism provided on the front side of a cylindrical body unit, thereby enabling the attaching/detaching to be effectively restricted in order to prevent the toner from scattering. 
   Still further, a maximum height of the protrusion from the center of the cylinder is smaller than a major diameter of the cylindrical body unit, and there is provided a sufficiently-wide cylindrical surface on the rear side thereof. Hence, a handling characteristic is improved, and a size of the whole becomes compact, whereby costs for packing, transporting and stocking can be reduced.