Abstract:
An image forming apparatus of the present invention is operable with a waste toner bottle removably mounted thereto for collecting residual toner left on an image carrier after image formation. The image forming apparatus includes a handle to be held by an operator for holding the waste toner bottle, and a locking mechanism included in the handle for preventing the waste toner bottle from coming off the apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a copier, printer, facsimile apparatus, multifunction apparatus or similar electrophotographic image forming apparatus and more particularly to an image forming apparatus of the type including a process cartridge and a method of mounting or dismounting a waste toner bottle.  
         [0003]     2. Description of the Background Art  
         [0004]     Today, there is an increasing demand for toner with a small grain size or produced by polymerization that implements high image quality required of a printer, copier or similar image forming apparatus. Also, a current trend is toward an image forming apparatus of the type operable with a process cartridge removably mounted thereto. In this type of image forming apparatus, a waste toner bottle is removably mounted for collecting residual toner removed from a photoconductive element after image transfer. The problem with the waste toner bottle is that it is apt to come off the image forming apparatus and cause the toner to fly about or drop, smearing the operator of the apparatus or the apparatus itself.  
         [0005]     In light of the above, Japanese Patent Laid-Open Publication No. 2003-36011, for example, discloses a mechanism in which a locking portion, included in a lever for releasing an intermediate image transfer belt, locks or unlocks a waste toner bottle to or from an apparatus body in interlocked relation to the contact or the release, respectively, of the belt. This mechanism, however, has a drawback that because the waste toner bottle is simply positioned in an unstable condition, it is apt to drop due to, e.g., an impact when the user unlocks the waste toner bottle by holding the lever and turning it in the unlocking direction. To solve this problem, it is necessary for the user to unlock the waste toner bottle while holding it.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the present invention to prevent a waste toner bottle from easily coming off an image forming apparatus while promoting easy replacement of the bottle.  
         [0007]     An image forming apparatus of the present invention is operable with a waste toner bottle removably mounted thereto for collecting residual toner left on an image carrier after image formation. The image forming apparatus includes a handle to be held by an operator for holding the waste toner bottle, and a locking mechanism included in the handle for preventing the waste toner bottle from coming off the apparatus.  
         [0008]     Also, in a method of mounting or dismounting a waste toner bottle to or from an image forming apparatus of the present invention, an operator slides a locking member to a preselected locking position or a preselected unlocking position with a thumb while holding a handle included in said waste toner bottle with one hand to thereby mount or dismount, respectively, the waste toner bottle to or from the image forming apparatus. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description taken with the accompanying drawings in which:  
         [0010]      FIG. 1  shows the general construction of an image forming apparatus embodying the present invention;  
         [0011]      FIG. 2  is a fragmentary enlarged view showing major part of the illustrative embodiment;  
         [0012]      FIG. 3  is a view showing one of process cartridges included in the illustrative embodiment;  
         [0013]      FIG. 4  shows the process cartridge and a waste toner bottle included in the illustrative embodiment;  
         [0014]      FIG. 5  shows arrangements around the waste toner bottle of the illustrative embodiment;  
         [0015]      FIGS. 6A through 6C  show a slide type locking mechanism included in the illustrative embodiment for locking or unlocking the waste toner bottle;  
         [0016]      FIGS. 7A and 7B  demonstrate the operation of the slide type locking mechanism;  
         [0017]      FIGS. 8A through 8C  show a push type locking mechanism replaceable with the slide type locking mechanism; and  
         [0018]      FIG. 9  demonstrates the operation of the push type locking mechanism. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0019]     Referring to  FIG. 1  of the drawings, an image forming apparatus embodying the present invention is shown.  FIG. 2  shows major part of the illustrative embodiment in a fragmentary enlarged view. As shown, an intermediate image transfer belt (simply belt hereinafter)  1  is positioned at substantially the center of the inside of the apparatus. The belt  1 , implemented as an endless belt, includes a base member formed of polyimide, polyamide or similar heat-resistant material and provided with medium resistance. The belt  1  is passed over a plurality of rollers and caused to turn in a direction indicated by an arrow A in  FIG. 1 .  
         [0020]     Four process cartridges  11   a ,  11   b ,  11   c  and  11   d  are positioned side by side along the lower run of the belt  1  and respectively include photoconductive drums  10   a ,  10   b ,  10   c  and  10   d  that contact the lower run or the belt  1 . It is to be noted that the photoconductive drums (simply drums hereinafter)  10   a  through  10   d  each are a specific form of an image carrier. Arranged around the drums  10   a  through  10   d  are charge rollers  15   a ,  15   b ,  15   c  and  15   d  and cleaning units  14   a ,  14   a ,  14   c  and  14   d , respectively. Developing units  16   a ,  16   b ,  16   c  and  16   d  are positioned in correspondence to the process cartridges  11   a  through  11   d , respectively, and identical in configuration with each other except for the color of toner to use.  
         [0021]     The process cartridges  11   a  through  11   d  are identical in configuration with each other, but form a black toner image, a yellow toner image, a cyan toner image and a magenta toner image, respectively.  
         [0022]     An optical writing unit  9  is located below the process cartridges  11   a  through  11   d  and includes four LDs (Laser Diodes) or light sources each being assigned to a particular color. The optical writing unit  9  further includes a polygonal scanner made up of a six-face polygonal mirror and a polygon motor, f-θ lenses each being positioned on the optical path of a particular LD, elongate cylindrical lenses or similar lenses and mirrors. A laser beam emitted from any one of the LDs is deflected by the polygonal scanner and then incident on associated one of the drums  10   a  through  10   d.    
         [0023]     Image transfer rollers  13  respectively face the drums  10   a  through  10   d  with the intermediary of the belt  1  in order to transfer toner images formed on the drums  10   a  through  10   d  to the belt  1 . This image transfer will be referred to as primary image transfer. The image transfer rollers  13  are connected to a power supply, not shown, to be applied with a preselected voltage therefrom.  
         [0024]     A secondary image transfer roller  5  is pressed against the outside of part of the belt  1  supported by a roller  51  and is connected to a power supply, not shown, to be applied with a preselected voltage therefrom. The position where the secondary image transfer roller  5  and belt  1  contact each other constitutes a secondary image transfer zone for transferring a composite toner image from the belt  1  to a paper sheet or similar recording medium. A belt cleaning unit  12  faces the outside surface of the portion of the belt  1  supported by a roller  52  in order to clean the outside surface of the belt  1  after secondary image transfer.  
         [0025]     A fixing unit  4  is positioned above the secondary image transfer zone for permanently fixing the composite toner image transferred from the belt  1  to the paper sheet. A paper feeding unit  8  is positioned in the lower portion of the apparatus and loaded with a stack of paper sheets. The sheets are fed from the paper feeding unit  8  toward the secondary image transfer zone one by one.  
         [0026]     The operation of the illustrative embodiment will be described hereinafter. Toner bottles  2  respectively store yellow toner, cyan toner, magenta toner and black toner, as named from the left to the right in  FIG. 1 . Each toner is replenished from a particular toner bottle  2  to preselected one of the developing units  16   a  through  16   d  via a path, not shown, in a preselected amount.  
         [0027]     When the apparatus is caused to start operating, the drums  10   a  through  10   d  rotate clockwise, as viewed in  FIG. 1 , while charge rollers  15   a  through  15   d  uniformly charge the surfaces of the drums  10   a  through  10   d , respectively. The optical writing unit  9  scans the surfaces of the drums  15   a  through  15   d  thus scanned with laser beams in accordance with respective image data, thereby forming latent images of respective colors on the drums  15   a  through  15   d . Subsequently, the developing units  16   a  through  16   d  develop the latent images formed on the drums  10   a  through,  10   b  with magenta toner, cyan toner, yellow toner and black toner, thereby producing toner images of four different colors.  
         [0028]     On the other hand, a pickup roller  7 , included in the paper feeding unit  8 , pays out the top paper sheet toward a registration roller pair  6 . The registration roller pair  6  stops the paper sheet and then drives it toward the secondary image transfer zone between the secondary image transfer roller  5  and the belt  1  in accordance with the output of a sensor, not shown, responsive to the leading edge of the paper sheet.  
         [0029]     Subsequently, voltages are applied to the image transfer rollers  13  so as to sequentially transfer the toner images of different colors from the drums  10   a  through  10   d  to the belt  1  one above the other. At this instant, the image forming operation is shifted in timing from the upstream side to the downstream side such that the toner images are transferred to the same position of the belt  1  one above the other, thereby completing a full-color toner image on the belt  1 . When the four-color toner image is conveyed to the secondary image transfer zone by the belt  1 , it is transferred from the belt  1  to the paper sheet by the secondary image transfer roller  5 . The paper sheet, carrying the full-color toner image thereon, is then conveyed to the fixing unit  4 . The fixing unit  4  fixes the toner image on the paper sheet with heat and pressure. The paper sheet or print, coming out of the fixing unit  4 , is driven out of the apparatus by an outlet roller pair  3 .  
         [0030]     Toners left on the drums  10   a  through  10   d  after the primary image transfer are removed by the cleaning units  14   a  through  14   d , respectively. Likewise, toner left on the belt  1  after the secondary image transfer is removed by the belt cleaning unit  12 .  
         [0031]      FIG. 3  shows one of the process cartridges  11   a  through  11   d  while  FIG. 4  shows the process cartridge together with a waste toner bottle also included in the illustrative embodiment. As shown, a coil  17 , disposed in each cleaning unit represented by the reference numeral  14 , conveys the waste toner removed from the drum  10  to a waste toner bottle  20  mounted on the apparatus via a waste toner outlet  19 , which is formed in a waste toner pipe  18  included in the process cartridge  11 . If desired, the waste toner may be conveyed to a waste toner bottle via a waste toner path formed in the apparatus instead of being directly delivered to the waste toner bottle  20 , although not shown specifically.  
         [0032]      FIG. 5  shows arrangements around the waste toner bottle  20  mounted to the apparatus. As shown, the waste toner bottle  20  is mounted to an openable cover  21  included in the apparatus and is mounted to or dismounted from the apparatus by opening the cover  21 . The waste toner bottle  20  includes a handle  22  provided with a slide type locking member  23  while the cover  21  includes a slide type hook member  24 . When the locking member  23  is engaged with the hook member  24 , the waste toner bottle  20  is prevented from dropping from the cover  21 . This kind of arrangement is usable even when the waste toner bottle  20  is not mounted to the cover  21 , but is mounted to the apparatus.  
         [0033]      FIGS. 6A through 6C  show a slide type locking mechanism included in the illustrative embodiment. More specifically,  FIGS. 6A and 6  show an unlocked condition and a locked condition, respectively. As shown in  FIG. 6C  in a section, when the slidable locking member  23  is engaged with the hook member  24  of the cover  21 , the waste toner bottle  20  is prevented from dropping from the cover  21 .  
         [0034]      FIGS. 7A and 7B  respectively correspond to  FIGS. 6A and 6B  that show the locked condition and unlocked condition of the slide type locking mechanism. As shown, an operator is capable of mounting or dismounting the waste toner bottle  20  by holding the handle  22  that includes the locking mechanism, and therefore capable of easily replacing the bottle  20  with one hand.  
         [0035]      FIGS. 8A through 8C  show an alternative locking mechanism in accordance with the present invention. More specifically,  FIG. 8A  shows members arranged around the handle  22  of the waste toner bottle  20  while  FIGS. 8B and 8C  show an unlocked condition and a locked condition, respectively. As shown in  FIG. 8B , when the operator pushes a press portion  25   a  included in a push type locking member or thumb piece  25 , the push portion  25   a  bends a lever with the result that the locking member  25  is released from a cover hook member  26 .  
         [0036]      FIG. 9  shows the operation of the push type locking mechanism of  FIGS. 8A through 8C . As shown, by pushing the push portion  25   a  while holding the handle  22 , the operator is capable of mounting or dismounting the waste toner bottle  20  with one hand and therefore as easily as with the slide type locking mechanism.  
         [0037]     In summary, in accordance with the present invention, a waste toner bottle mounted to an image forming apparatus is prevented from coming off and can be easily mounted to or dismounted from the apparatus by one hand.  
         [0038]     Various modifications will become possible for those skilled in the art after receiving the teachings of the present disclosure without departing from the scope thereof.