Abstract:
An embodiment according to the invention is characterized in that a waste toner is delivered to a certain place through a rotation of a stirring member (a paddle) for causing the waste toner to be even and the waste toner thus delivered is detected by means of detecting unit (an optical sensor).

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based upon and claims the benefit of priority from: U.S. Provisional Application No. 60/971,245 filed on Sep. 10, 2007, the entire contents of each of which are incorporated herein reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to an image forming apparatus capable of obtaining a copy image or print out of an object. 
       BACKGROUND 
       [0003]    For an image forming apparatus capable of using, as a recording material (a sheet material), a general plain paper which is not subjected to a special processing, image forming apparatuses utilizing various methods such as an electrophotographing method, an ink jet method and a thermal transfer method already spread widely. The image forming apparatus is changed to be multifunctional in accordance with a diversification of a request given from a user, and is currently referred to as a Multi-Functional peripheral (MFP). 
         [0004]    In the MFP using the electrophotographing method, a latent image is visualized through a visualizing material which is referred to as a toner. In the electrophotographing method, the toner is selectively positioned on an output medium. 
         [0005]    A part of the toner remains on a latent image holding member (without the transfer). A collecting mechanism collects the toner remaining on the latent image holding member. A housing container stores the toner collected by the collecting mechanism. 
         [0006]    For example, JP-A-2003-148884 describes an example in which (a sensor) detects that a housing container is filled with the collected toner. The publication describes that a delivering member having a spiral blade delivers the waste toner from both ends in a longitudinal direction of a boxy body to a center. In the publication, the sensor for detecting the fill-up is positioned in the vicinity of a delivery termination for the waste toner and a collecting port having a maximum amount of collection. 
         [0007]    In some cases, however, the sensor detects the fill-up before the housing container is filled with the toner. 
       SUMMARY 
       [0008]    The invention provides an image forming apparatus comprising: a photoconductor which holds a latent image; a developing device which supplies a toner to the latent image to carry out a development; a collector which collects the toner from the photoconductor; a housing which stores the toner collected by the collector; an auger which collects the toner into a predetermined position in the housing; and a detector, non-contact with the housing, which detects that the toner collected by the collector is present in a predetermined amount or more in the housing. 
         [0009]    Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter. 
     
    
     
       DESCRIPTION OF THE DRAWINGS 
         [0010]    The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention, and together with the general description given above and the detailed description of the embodiments given below, serve to explain the principles of the invention. 
           [0011]      FIG. 1  is a view showing an example of an imaging forming apparatus (a Multi-Functional Peripheral (MFP)) to which an embodiment of the invention is applied; 
           [0012]      FIG. 2  is a view showing a toner collecting mechanism and a housing section in the MFP illustrated in  FIG. 1 ; 
           [0013]      FIG. 3  is a view showing the housing section illustrated in  FIG. 2 ; 
           [0014]      FIG. 4  is a view showing the housing section illustrated in  FIG. 2 ; 
           [0015]      FIG. 5  is a partial sectional view showing the housing section illustrated in  FIG. 4 ; 
           [0016]      FIG. 6  is a view showing an example of a paddle of the housing section illustrated in  FIG. 2  and a toner sensor; and 
           [0017]      FIG. 7  is a diagram schematically showing a control system of the MFP illustrated in  FIGS. 1 to 6 . 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    An example of an embodiment according to the invention will be described below in detail with reference to the drawings. 
         [0019]      FIG. 1  schematically shows an image forming apparatus (MFP, Multi-Functional Peripheral) to which the invention can be applied. 
         [0020]    An image forming apparatus  101  shown in  FIG. 1  has an image forming section body  1  for outputting image information as an output image which is referred to as a hard copy or a print out, for example, a paper supplying section  3  capable of supplying, to the image forming section body  1 , a paper (an output medium) having an optional size which is used for an image output, and an image reading section  5  for fetching, as image data, image information to be an image forming object in the image forming section body  1  from a object holding the image information (which will be hereinafter referred to as an original). The image reading section  5  includes an original table (an original glass)  5   a  for supporting an object and an image sensor for converting the image information into image data, for example, a CCD sensor, which will not be described in detail. The image reading section  5  converts a reflected light into an image signal through the CCD sensor. The reflected light is obtained by irradiating a light from an illuminating apparatus (not shown) onto the original set into the original table  5   a.    
         [0021]    An instruction input section for giving an instruction for starting an image formation in the image forming section body  1  and starting to read image information of the original through the image reading section  5 , that is, a control panel (operating section)  9  is placed in a predetermined position of the image forming apparatus  101  which cannot be seen in  FIG. 1 . 
         [0022]    The image forming section body  1  includes first to fourth photoconductive drums  11   a  to  11   d  for holding latent images, developing devices  13   a  to  13   d  for supplying a developer, that is, a toner to the latent images held by the photoconductive drums  11   a  to  11   d  and carrying out a development, a transfer belt  15  for holding toner images held by the photoconductive drums  11   a  to  11   d  in order, cleaners  17   a  to  17   d  for removing the toner remaining on the photoconductive drums  11   a  to  11   d  from the individual photoconductive drums  11   a  to  11   d,  a transfer device  19  for transferring the toner image held by the transfer belt  15  onto a plain paper or a sheet-like transfer medium (hereinafter referred to as a sheet material) such as an OHP sheet to be a transparent resin sheet, a fuser unit  21  for fixing the toner image transferred to the sheet material by the transfer device  19  onto the sheet material, and an exposing device  23  for forming latent images on the photoconductive drums  11   a  to  11   d  and the like. 
         [0023]    The first to fourth developing devices  13   a  to  13   d  store toners having optional colors of Y (yellow), M (magenta), C (cyan) and Bk (black) which are used for obtaining a color image by a subtractive process and visualize a latent image held by each of the photoconductive drums  11   a  to  11   d  in any of the colors Y, M, C and Bk. The respective colors are determined in predetermined order corresponding to an image forming process or a characteristic of the toner. 
         [0024]    The transfer belt  15  holds the toner images having the respective colors which are formed by the first to fourth photoconductive drums  11   a  to  11   d  and the corresponding developing devices  13   a  to  13   d  in order (of the formation of the toner images). 
         [0025]    The paper supply section  3  supplies, in a predetermined timing, the sheet material to be used for transferring the toner image by the transfer device  19 . 
         [0026]    Cassettes, which will not be described in detail, positioned in a plurality of cassette slots  31  store sheet materials having optional sizes. Depending on an image forming operation which will not be described in detail, a pickup roller  33  takes the sheet material out of the corresponding cassette. The size of the sheet material corresponds to a size of the image of the developer formed by the image forming section body  1 . 
         [0027]    A separating mechanism  35  prevents at least two sheet materials from being taken out of the cassette by the pickup roller  33 . 
         [0028]    A plurality of delivery rollers  37  feed the sheet material separated to be one sheet by the separating mechanism  35  toward an aligning roller  39 . 
         [0029]    The aligning roller  39  feeds the sheet material to a transfer position in which the transfer device  19  and the transfer belt  15  come in contact with each other in a timing for transferring the image of the developer from the transfer belt  15  by the transfer device  19 . 
         [0030]    The fuser unit  21  fixes the image of the developer (toner) corresponding to the image information onto the sheet material, that is, the output image (hard copy, print out) and feeds the output image to a stock section  51  positioned in a space between the image reading section  5  and the image forming section body  1 . 
         [0031]    The transfer belt  15  holds the toner remaining on the transfer belt  15  (which will be hereinafter referred to as a waste toner) and a belt surface is moved. A belt cleaner  41  coming in contact with the transfer belt  15  in a predetermined position removes, from the transfer belt  15 , the waste toner held on the belt surface of the transfer belt  15 . 
         [0032]    A housing container  71  is positioned between a side of the slot  31  and a frame rigid body  101   a  of the image forming apparatus  101 . 
         [0033]      FIG. 2  shows a positional relationship between a waste toner delivering mechanism and the housing container. 
         [0034]    A waste toner delivering mechanism  61  feeds, to the housing container  71 , the waste toner removed from the photoconductive drums  11   a  to  11   d  by the cleaners  17   a  to  17   d  and the waste toner removed by the belt cleaner  41 , which are described above. The waste toner delivering mechanism  61  includes a first waste toner delivering section  63  for feeding the waste toner removed by the belt cleaner  41  to the housing container  71  and a second waste toner delivering section  65  for feeding the waste toner removed by the cleaners  17   a  to  17   d  to the housing container  71 , which will not be described in detail. 
         [0035]    A relay delivering section  67  is positioned between the housing container  71  and the first and second waste toner delivering sections  63  and  65 . The relay delivering section  67  connects the first and second waste toner delivering sections  63  and  65  to an almost central housing port  73  in a longitudinal direction of the housing container  71 . 
         [0036]      FIG. 3  shows an example of the housing container. 
         [0037]    The housing container  71  includes a paddle  75  stirs the waste toner in the housing container  71  and collects a part of the waste toner into a predetermined position in the housing container  71 . The paddle  75  has a coupling  77  for receiving a rotating force from an outside at one end in the longitudinal direction of the housing container  71 . The coupling  77  is rotated through a rotation of a shaft of a motor  91  shown in  FIG. 7  (which is connected to the coupling  77 ). The motor  91  is placed in a predetermined position on a back side of the image forming apparatus  101  (not shown). The coupling  77  has a looseness in an axial direction shown in an arrow A which serves to easily carry out coupling to the shaft of the motor  91 . The coupling  77  also has a looseness in an orthogonal direction to a shaft shown in an arrow B which serves to easily carry out coupling to the shaft of the motor  91 . 
         [0038]    The housing container  71  has a guide section (a rib or a groove)  71   a  for guiding a movement from a front side of the image forming apparatus  101 . 
         [0039]      FIGS. 4 and 5  show a positional relationship between the housing container and the toner sensor. 
         [0040]    The housing container  71  has a fill-up detecting region  79  for permitting a toner sensor  81  to detect (a level of) the waste toner when (the housing container  71  is filled with the waste toner). The fill-up detecting region  79  is positioned above an outer periphery of a rotating circle of the paddle  75  of the housing container  71  by 20 mm or more, for example, (an upper limit of 30 mm) and is (a space) having a smaller width d than a width W of the housing container  71 . d and W are approximately ⅓ to ⅕. A depth (an inside height) h is equal to the width d or reaches a position corresponding to the position provided above the outer periphery of the rotating circle of the paddle  75  by 20 mm or more, for example (the upper limit of 30 mm). As an example, the housing container  71  has a size of approximately 200 to 300 mm in a vertical direction, 400 to 500 mm in a longitudinal direction and 40 mm in a transverse direction. 
         [0041]    The fill-up detecting region  79  permits a toner sensor  81  to continuously detect (a presence of) the waste toner accumulated in the housing container  71  for a predetermined time. 
         [0042]    The fill-up detecting region  79  is positioned close to the back face of the image forming apparatus  101 . 
         [0043]    The toner sensor  81  detects that the waste toner is filled in the housing container  71  in a predetermined position on the outside of the housing container  71 . The toner sensor  81  is of a well-known optical type in which a light transmitting section (a light source) and a light receiving section (a photodetector) are provided at a predetermined interval. The toner sensor  81  may serve to detect an electrostatic capacity. 
         [0044]    The toner sensor  81  is placed in a position in which the housing container  71  can be attached from the front side of the image forming apparatus  101 . The toner sensor  81  permits the housing container  71  to be moved to the front side of the apparatus  101 . The fill-up detecting region  79  is placed in a position in which the housing container  71  can be attached from the front side of the image forming apparatus  101  without hindering the toner sensor  81  from being operated. 
         [0045]      FIG. 6  shows an example of the paddle for the housing container. 
         [0046]    The paddle  75  has a plurality of blade members taking a predetermined shape which provides a delivery force for delivering the toner in one direction. Each of the blade members of the paddle  75  wholly has such a shape as to deliver the waste toner to the back side of the image forming apparatus  101  (in an assembling state). The closest blade member to the back face has such a shape as to deliver the waste toner to the front side of the image forming apparatus  101 . The paddle  75  collects the waste toner more greatly in a predetermined position which is close to the back face of the housing container  71  as compared with other positions in the longitudinal direction. The paddle  75  increases a density of the waste toner which corresponds to a position in which the toner sensor  81  detects the waste toner. The paddle  75  increases the accumulation height (volume) of the waste toner which corresponds to a position in which the toner sensor  81  detects the waste toner. An axis of the paddle  75  is offset from a center in a transverse direction of the fill-up detecting region  79 . An opening section of the fill-up detecting region  79  is opposed to a rotating direction of the paddle  75 . 
         [0047]      FIG. 7  shows elements for controlling a rotation of the paddle for the housing container. 
         [0048]    The image forming apparatus (MFP)  101  includes a system bus line  111 . The system bus line  111  connects a main control block, that is, a main CPU  112  for processing image information of an object to be outputted by an image forming section  1  including a scanner (image reading section)  5  and an image processor  117 , and the image forming section  1 . The main control block  112  connects an ROM (Read Only Memory)  113 , an RAM (Random Access Memory)  114 , and a Non-volatile RAM  115  for storing a total rotating number or a total rotating time of the motor  91 , the number of image forming operations, a total operating (working) time or the like, an interface  116  for giving an instruction of an output of the toner sensor  81  to the main control block  112 , and an operation panel. The image processor  117  connects a page memory  118 . The image forming section  1  connects a motor driver  119  for rotating the motor  91 , a timer  120  for counting a time required for connecting a commercial power to a power supply  122 , and a counter  121  for counting the number of the image forming operations of the image forming section  1  (the number of the outputs of the print out). 
         [0049]    The motor  91  does not rotate until the number of image forming operations, that is, a count value of the counter  121  reaches a certain value, for example. More specifically, the motor  91  can also compensate for the influence of JAM. Some count values are varied in accordance with the size of the paper (sheet material). The count value of A3 is a double of that of A4. 
         [0050]    The motor  91  does not rotate until the number of image outputs, that is, the count value of the counter  121  reaches a certain value, for example. 
         [0051]    The motor  91  rotates for a certain period every predetermined time when the image formation (the number of the outputs of the print out, that is, the count value of the counter  121 ) exceeds the certain value. 
         [0052]    The motor  91  rotates for a predetermined period when a power supply of the image forming apparatus  101  is turned ON (the power supply  122  connects the commercial power). The motor  91  rotates for a certain time every predetermined period based on the timing of the timer  120 , for example. 
         [0053]    The motor  91  rotates while the developing devices  13   a  to  13   d  operate. 
         [0054]    The motor  91  rotates for a period in which the belt surface of the transfer belt  15  moves. 
         [0055]    The motor  91  rotates while the transfer medium is delivered. 
         [0056]    The image forming apparatus according to the embodiment of the invention prevents the detection of the fill-up before the container for storing the waste toner is filled up. 
         [0057]    Moreover, the container of the image forming apparatus according to the embodiment of the invention is reliably filled with the waste toner. Therefore, the container substantially prevents the necessity of an exchange for a life cycle in which the developing device and the photoconductive drum need to be exchanged. 
         [0058]    Furthermore, the image forming apparatus according to the embodiment of the invention reduces an exchange frequency of the waste toner housing container. Therefore, a running cost can be reduced. 
         [0059]    Additional advantages and modifications will readily occur to those skilled in the art. Therefore, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described herein. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and their equivalents.