Abstract:
An electrophotographic apparatus for forming a toner image on a recording medium including an image fixing apparatus and a member for reducing a harmful volatile organic compound (VOC) generated by heat of the image fixing apparatus. The image fixing apparatus is configured to fix the toner image onto the recording medium by heat and pressure. Additionally, a member including an activated carbon is provided at a predetermined position adjacent the image fixing apparatus and configured to contact heated air generated by the image fixing apparatus.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention generally relates to an electrophotographic apparatus, such as a printer, a copying machine, and a facsimile machine, and more particularly to an electrophotographic apparatus capable of reducing volatile organic compound generated with heat of an image fixing apparatus.  
         [0003]     2. Discussion of the Background  
         [0004]     Image forming apparatuses, such as printers, copying machines, and facsimile machines, which use an electrophotographic method are generally regulated by law with respect to the generation of bad odors and the content of toxic substances generated. The amount of generated volatile organic compound (VOC) has been standardized by law in recent years. The amount of generated VOC is easy to change based on the amount of heat used in the electrophotographic apparatus. The heat generated by an image fixing apparatus using a heat roller or a heat belt largely affects the amount of generated VOC. The greater the amount of heat generated by the apparatus, the greater the total amount of VOC (TVOC) generated. The main source of the VOC is adhesives and silicone rubber in the image fixing apparatus. The VOC is generated from the adhesives and silicone rubber at fixing temperature. Such VOC is needed to be reduced.  
         [0005]     To reduce the VOC, in one example, a filter containing activated carbon is provided at an exhaust slot like the method of reducing ozone. Specifically, two or more tubular exhaust passageways are provided with a filter containing activated carbon behind an exhaust fan.  
         [0006]     In another example, an electrophotographic apparatus has an air vacuum, a dust filter, a photocatalyst filter, and an ultraviolet-rays lamp to reduce the VOC physically and chemically.  
       SUMMARY OF THE INVENTION  
       [0007]     A novel electrophotographic apparatus effectively reduces a harmful volatile organic compound (VOC) generated by heat of an image fixing apparatus. In one example, a novel electrophotographic apparatus for forming a toner image on a recording medium includes an image fixing apparatus to fix the toner image onto the recording medium by heat and pressure and a member including an activated carbon provided above the image fixing apparatus for reducing the generated VOC. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]     A more complete appreciation of the disclosure and many of the attendant advantages thereof will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, wherein:  
         [0009]      FIG. 1  is an illustration illustrating an exemplary configuration of an electrophotographic apparatus according to an exemplary embodiment of the present invention;  
         [0010]      FIG. 2  is an illustration of an image fixing apparatus of the electrophotographic apparatus of  FIG. 1 ;  
         [0011]      FIG. 3  is an illustration of a paper ejection section of the image fixing apparatus of  FIG. 2 ;  
         [0012]      FIG. 4  is an illustration of an exemplary configuration of a cover in the electrophotographic apparatus of  FIG. 1 ;  
         [0013]      FIG. 5  is an illustration of another exemplary configuration of a cover in the electrophotographic apparatus of  FIG. 1 ; and  
         [0014]      FIG. 6  is an illustration of another exemplary configuration of a cover in the electrophotographic apparatus of  FIG. 1 . 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0015]     In describing preferred embodiments illustrated in the drawings, specific terminology is employed for the sake of clarity. However, the disclosure of this patent specification is not intended to be limited to the specific terminology so selected and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner. Referring now to the drawings, wherein like reference numerals designate identical or corresponding parts throughout the several views, particularly to  FIG. 1 , an electrophotographic apparatus  1  according to an exemplary embodiment of the present invention is explained.  
         [0016]      FIG. 1  is an illustration illustrating an exemplary configuration of an electrophotographic apparatus according to an exemplary embodiment of the present invention. An exposing unit  1  makes a toner image on photo conductors  21 ,  22 ,  23 , and  24  for each color based on image data from a scanner or a personal computer. The toner image is transferred onto a middle transfer belt  3  to make a mixed color image. The toner image is transferred using a second transfer  4  from the middle transfer belt  3  onto a paper sheet conveyed by a resist roller  5 . The paper sheet with transferred toner image is conveyed into an image fixing apparatus  8  by a conveyor belt  6  and the toner image is fixed on the paper sheet with heat and pressure in the image fixing apparatus  8 .  
         [0017]      FIG. 2  is an illustration of an image fixing apparatus  8  of the electrophotographic apparatus of  FIG. 1 . The image fixing apparatus  8  includes a fixing roller  50  having a heater  55  as a heat source. Fluoro-resin is provided on the surface of the fixing roller  50  made of silicone rubber  50   a . A pressing roller  70  presses the fixing roller  50  and rotates with the fixing roller  50 . The temperature of the surface of the fixing roller  50  is detected with a temperature sensor  53  for controlling fixing temperature. The toner image is fixed on the paper sheet with heat and pressure at the fixing temperature.  
         [0018]     The image fixing apparatus  8  is a belt type image fixing apparatus. The heating roller  60  made of metal also includes heaters  65  and  66 . A fixing belt  40  made of metal base such as nickel, stainless steel, etc. or made of resin base such as polyimide, polyamide-imide, etc. is tensed between the fixing roller  50  and the heating roller  60 . Fluoro-resin is provided on the silicone rubber on the base of the fixing belt  40 . The fixing belt  40  is driven to rotate by the fixing roller  50 .  
         [0019]     The pressing roller  70  also includes a heater  75  as a heat source. Fluoro-resin is provided on the surface of the pressing roller  70  made of silicone rubber  70   a . The heaters  55 ,  65 ,  66 , and  75  are ON-OFF controlled based on the detected temperature using the temperature sensors  53 ,  63 , and  73 . Two or more temperature sensors  53  detect the temperatures of the center region and the end region in the main scanning direction of the fixing belt  40 , respectively.  
         [0020]     A pressing nip region is formed between the fixing belt  40  and the pressing roller  70  with distortion of the silicone rubbers  50   a  and  70   a . The toner image on the paper sheet is fixed on the paper sheet by receiving heat and pressure in the nip region. A waste toner on the fixing belt  40  is cleaned by a cleaning roller  80 .  
         [0021]     In  FIG. 1 , a member  36  containing activated carbon is formed on the fixing apparatus  8  side of a cover  35  with which the heat of fixing is prevented from reaching the middle transfer belt  3 . The VOC rises with the heated air from the image fixing apparatus  8 . The VOC is reduced by adsorption of the activated carbon in the member  36  without disturbing the air flow of the heat. This simple construction may effectively reduce the VOC output.  
         [0022]     In  FIG. 2 , the fixing apparatus  8  has a cover  46  for reducing the effect of heat to the other units. A member  47  containing activated carbon is provided on the inside surface of the cover  46 . The VOC rises with air heated by the rollers  50 ,  60 , and  70  in the image fixing apparatus  8 , and the VOC collects inside the cover  46 . The VOC is reduced by adsorption of the activated carbon in the member  47  without raising the temperature inside of the electrophotographic apparatus due to disturbing the air flow of the heat. This simple construction may effectively reduce the VOC output.  
         [0023]      FIG. 3  is an illustration of a paper ejection section of the image fixing apparatus of  FIG. 2 . The paper ejection section of the image fixing apparatus  8  has paper guides  90 ,  95 ,  110 , and  115 . Ribs  90   a  are provided on the upper paper guide  90 . A member  91  containing activated carbon is also provided between the ribs  90   a  on the upper paper guide  90  so that the member  91  is shorter than the ribs  90   a . Ribs  110   a  are provided on the upper paper guide  110 . A member  111  containing activated carbon is also provided between the ribs  110   a  on the upper paper guide  110  so that the member  111  is shorter than the ribs  110   a . The VOC is discharged along with the upper paper guides  90  and  110  with the air flow caused by the heat of fixing and the conveyance of the paper. The ribs  90   a  and  110   a  effectively lead the VOC, so the members  91  and  111  containing activated carbon between the ribs  90   a  and  110   a  effectively absorb the VOC without increasing conveyance load of the paper and air resistance. This simple construction may effectively reduce the VOC output.  
         [0024]      FIG. 4  is an illustration of another exemplary configuration of a cover in the image fixing apparatus of  FIG. 1 . The members  36  and  47  are formed in the shape of a waveform sheet. The members  36  and  47  include the activated carbon and the members  36  and  47  are provided so that the waveform is formed one by one in the sub-scanning direction. Air flow generated toward the sub-scanning direction by the conveyance of the sheet and by heat of the image fixing apparatus  8  may be held in the waveform members  36  and  47 . Therefore, the holding time of the VOC along with the members  36  and  47  may be longer than that of the above-mentioned members  36  and  47  in  FIG. 3  having flat surfaces. This effectively reduces the VOC by providing a longer time of adsorption into the activated carbon.  
         [0025]      FIG. 5  is an illustration of another exemplary configuration of a cover in the image fixing apparatus of  FIG. 1 . The members  36  and  47  are formed in the shape of a sheet having ribs  36   a  and  47   a  on it. The members  36  and  47  include the activated carbon and the members  36  and  47  are provided so that the ribs  36   a  and  47   a  are formed one by one in the sub-scanning direction. Air flow generated toward the sub-scanning direction by the conveyance of the sheet and by heat of the image fixing apparatus  8  may be held between the ribs  36   a  and  47   a . Therefore, the holding time of the VOC between the ribs  36   a  and  47   a  along with the members  36  and  47  may be longer than that of above-mentioned members  36  and  47  in  FIG. 3  having flat surface. This effectively reduces the VOC by providing a longer time of adsorption into the activated carbon.  
         [0026]      FIG. 6  is an illustration of another exemplary configuration of a cover in the image fixing apparatus of  FIG. 1 . The cover  35  has a hook at the end position to retain the member  36  including the activated carbon. The same hook configuration can also be used for the cover  46  to retain member  47 . Therefore, if the adsorption force is reduced with age, it is easy to replace the activated carbon members  36  and  47  with new ones. This effectively reduces the VOC with age.  
         [0027]     Numerous additional modifications and variations are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the disclosure of this patent specification may be practiced otherwise than as specifically described herein.  
         [0028]     This patent specification is based on Japanese Patent Application No. JPAP2005-267790 filed on Sep. 15, 2005 in the Japan Patent Office, the entire contents of which is incorporated by reference herein.