Abstract:
An image forming device includes: image forming unit that controls illumination of light sources based on image data and forms electrostatic latent image, develops the electrostatic latent image to form an image, and transfers the image to a recording medium; a case that houses the image forming units; and a conveying section that conveys the recording medium while guiding the medium in a space between the case and the image forming unit.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is based on and claims priority under 35 USC 119 from Japanese Patent Application No. 2007-000677 filed Jan. 5, 2007. 
       BACKGROUND OF THE INVENTION 
     Technical Field 
       [0002]    The present invention relates to an image forming device. 
       SUMMARY 
       [0003]    According to an aspect of the invention, there is provided an image forming device including: an image forming unit that controls illumination of a light source based on image data and forms an electrostatic latent image, develops the electrostatic latent image to form an image, and transfers the image to a recording medium; a case that houses the image forming unit; and a conveying section that conveys the recording medium while guiding the medium in a space between the case and the image forming unit. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    Exemplary embodiments of the present invention will be described in detail based on the following figures, wherein: 
           [0005]      FIG. 1  is an outline configuration diagram of an image forming device according to a present exemplary embodiment; 
           [0006]      FIG. 2  is an outline configuration diagram of an image forming device according to a first alternate example; 
           [0007]      FIG. 3  is an outline configuration diagram of an image forming device according to a second alternate example; and 
           [0008]      FIG. 4  is an outline configuration diagram of an image forming device according to a third alternate example. 
       
    
    
     DETAILED DESCRIPTION 
       [0009]    Hereafter, an example of an exemplary embodiment of the present invention will be described in detail with reference to the drawings. 
         [0010]    The configuration of an image forming device  14  is shown in  FIG. 1 , wherein four image forming units  12 Y,  12 M,  12 C and  12 K are stacked in four levels in the vertical direction and these units form images of each color of Y (yellow), M (magenta), C (cyan), and K (black). Note that the up and down directions in  FIG. 1  are the vertical directions. 
         [0011]    A controller  16  and a power source  17  are provided at the left side in  FIG. 1  of the image forming units  12 Y,  12 M,  12 C,  12 K stacked in four levels. Here, the configuration components for the image forming units  12 Y,  12 M,  12 C,  12 K, the controller  16 , and the power source  17  are attached in a so-called cluster of parts in the central portion of a case  34 . As a result, a space  35  is provided to extend across the entire periphery between these configuration components and the case  34 . 
       [Configuration of Image Forming Units] 
       [0012]    The image forming units  12 Y,  12 M,  12 C,  12 K each use an LED-array print head (LPH)  10 Y as the light source (only shown for the image forming unit  12 Y, for the other image forming units  12 M,  12 C,  12 K, the structures are identical so indication by numbers has been omitted). The operation of the light source LPH is controlled by the controller  16 , and lighting of LPH is controlled based on the image data of each color. 
         [0013]    Disposed around a photoreceptor  18 Y are: a charging body  20 Y that uniformly charges the surface of the photoreceptor  18 Y; a developing unit  22 Y that supplies toner to electrostatic latent images and develops the electrostatic latent images; and a wiping unit  24 Y that wipes off any residual toner on the photoreceptor  18 Y after development. Note that only the above disposition is only shown for the image forming unit  12 Y in the drawing. The other image forming units  12 M,  12 C,  12 K, however, have structures that are similar to that of the image forming unit  12 Y with respective components disposed around photoreceptors  18 M,  18 C and  18 K, so explanation thereof and indication by numbers has been omitted. 
         [0014]    Each photoreceptor  18 Y,  18 M,  18 C,  18 K in the respective image forming units  12 Y,  12 M,  12 C,  12 K has a portion thereof that protrudes in the right direction of  FIG. 1  from a component that covers the image forming units  12 Y,  12 M,  12 C,  12 K, and these portions are in contact with an intermediate transfer belt  26  that is an endless belt-shaped form (i.e., the line of contact from the front of the paper surface in  FIG. 1  to the inner side of the device). 
         [0015]    The intermediate transfer belt  26  is wound around a top roller  28  provided in the vicinity of the image forming unit  12 Y of the uppermost level and a bottom roller  30  provided in the vicinity of the image forming unit  12 K of the lowermost step, and is made to circulate due to the driving force of a drive unit (not shown). Note that with the present exemplary embodiment, the belt circulates in the counterclockwise direction in  FIG. 1 . 
         [0016]    First transfer bodies  32 Y,  32 M,  32 C, and  32 K are arranged at the inner side of the intermediate transfer belt  26  at the portions of contact between the intermediate transfer belt  26  and the photoreceptors  18 Y,  18 M,  18 C,  18 K. A preset amount of pressure is imparted to the intermediate transfer belt  26  in a state where it is nipped between the photoreceptors  18 Y,  18 M,  18 C,  18 K and the first transfer bodies  32 Y,  32 M,  32 C,  32 K. 
         [0017]    The portions of contact between the intermediate transfer belt  26  and the photoreceptors  18 Y,  18 M,  18 C,  18 K respectively become the first transfer portions. The images of each color toner-developed on the photoreceptors  18 Y,  18 M,  18 C,  18 K are sequentially superimposed and transferred at these four places of these first transfer bodies  32 Y,  32 M,  32 C,  32 K. 
         [0018]    More specifically, when the intermediate transfer belt  26  circulates in the counterclockwise direction of  FIG. 1 , a Y-color image is transferred from the photoreceptor  18 Y of the image forming unit  12 Y of the uppermost level and when this transfer region reaches the image forming unit  12 M of the second level, an M-color image is transferred onto the same transfer region. Next, at the image forming unit  12 C of the third level, a C-color image is transferred onto the same transfer region. Lastly, a K-color image is transferred onto the same transfer region at the image forming unit  12 K of the lowermost step. As a result, an image with four colors (YMCK) superimposed thereon is created. 
         [0019]    Underneath the space  35  inside the case  34 , a pullout-type storage container  38  is provided in which paper  36  that is a recording medium is stacked and stored. 
         [0020]    The topmost layers of the paper  36  are taken out from this storage container  38  one sheet at a time by a paper-retrieving mechanism  39 . Next the paper  36  is sent up to the highest upstream side of the intermediate transfer belt  26  by a plurality of pairs of rollers and a paper-sending conveyer  37  formed from a plurality of pairs of guide boards, i.e., to the position where the paper  36  is inverted by the bottom roller  30 . 
         [0021]    In addition, the paper  36  is conveyed to the right side in  FIG. 1  of the intermediate transfer belt  26 , to along the direction of progression of the perimeter of the intermediate transfer belt  26 , by a main conveying unit  40  that consists of plural pairs of rollers and plural pairs of guide boards. 
         [0022]    The start position of the main conveying unit  40  is at the bottom roller  30  onto which the intermediate transfer belt  26  is wound. As a result, the configuration is such that the paper  36  contacts the intermediate transfer belt  26  at the region of the circular arc of contact of the bottom roller  30  with the intermediate transfer belt  26  (i.e., at a line of contact that runs from out of the page in  FIG. 1  into the page). 
         [0023]    A second transfer body  42  is arranged at the portion of contact between the bottom roller  30  and the intermediate transfer belt  26 . Because of this, the intermediate transfer belt  26  and the second transfer body  42  convey the paper  36  while nipping it with a preset pressure. 
         [0024]    The position where the pressure is imparted becomes the secondary transfer portion, and the full-color image, where the four colors were superimposed and transferred at the first transfer portions, is transferred to the paper  36  during conveyance thereof. 
         [0025]    The paper  36  onto which the full-color image is transferred at the secondary transfer portion is guided by the main conveying unit  40 , conveyed to the upper part in  FIG. 1 , and sent to a fixing unit  46 . 
         [0026]    A heat roller  48  and a pressing roller  50  are arranged opposite to each other in contact at the fixing unit  46 . The paper  36  enters into this portion of contact and is press-processed and heat-processed. A discharge conveying section  52  that consists of plural pairs of rollers is arranged at the upper portion that is the downstream side of the paper conveying direction of the fixing unit  46 . 
         [0027]    The paper  36  on which fix-processing was completed at the fixing unit  46  has its direction switched by the discharge conveying section  52  to the left-tilting direction of  FIG. 1  and is discharged to a discharge section  54  formed at the upper surface of the case  34 . 
       [Rotation Conveyance Path] 
       [0028]    A circulating conveying unit  60  that guides the paper  36  is provided at the downstream side of the fixing unit  46  separately from the discharge conveying section  52 . This circulating conveying unit  60  discharges the paper  36  once to the discharge section  54 , but retains the rear edge portion of the paper  36 . 
         [0029]    The circulating conveying unit  60  retaining the rear edge portion of the paper  36  reverses the direction in which the paper  36  is conveyed, and pulls the paper  36  back into the case  34  once again. 
         [0030]    The paper  36  that was pulled back in is conveyed by the circulating conveying unit, circulating conveying unit  60  underneath the space  35  of the left side of  FIG. 1  of the controller  16  and the power source  17 , and after being conveyed horizontally along the lower part of the space  35 , the paper  36  is returned to the secondary transfer portion. Hereafter, the conveying trajectory of this type of paper  36  (i.e., the conveying route trajectory that combines the main conveying unit  40  and the circulating conveying unit  60  and that circulates around the image forming units  12 Y,  12 M,  12 C,  12 K) is referred to as an “O-type path”. 
         [0031]    Here, it should be noted that image formation on both the front and back surfaces of the paper  36  becomes possible, i.e., on the paper  36  that is first pulled out from the storage container  38  and where an image is transferred onto a surface at the secondary transfer portion (on a first surface), and on a surface where the paper is returned with the circulating conveying unit  60  and an image is transferred at the secondary transfer portion (on a second surface). 
         [0032]    In addition, it becomes possible to extend the time from after fixing with the fixing unit  46  until discharging at the discharge section  54  by making the paper  36  pass through the “O-type path”. 
         [0033]    In addition, the “O-type path” is formed in the space  35  between the case  34  and the image forming units  12 Y,  12 M,  12 C,  12 K inside the case  34 . Due to this, when the cover components  56 ,  58  and the like provided at the case  34  are opened, as shown by the dashed line and double dotted line, respectively, in  FIG. 1 , the paper  36  (which is in the process of passing through the conveying unit  40  or the circulating conveying unit  60 ) is to be found at the outside of the case  34 . 
         [0034]    The operation of the present exemplary embodiment will be explained below. 
       [Image Formation Processing] 
       [0035]    When an image formation instruction is inputted to the controller  16 , image data is sent from the controller  16  to each image forming unit  12 Y,  12 M,  12 C,  12 K. 
         [0036]    First, with each image forming unit  12 Y,  12 M,  12 C,  12 K, the surfaces around the photoreceptors  18 Y,  18 M,  18 C,  18 K are uniformly made resistant to electricity with the charging body  20 Y (the same also applies for the other image forming units  12 M,  12 C,  12 K). 
         [0037]    Next, with each image forming unit  12 Y,  12 M,  12 C,  12 K, the illumination of the LPH  10 Y is controlled based on the image data (the same also applies for the other image forming units  12 M,  12 C,  12 K), and an electrostatic latent image is formed at the photoreceptors  18 Y,  18 M,  18 C,  18 K. 
         [0038]    The developing unit  22 Y supplies toner to the electrostatic latent image and then develops image to it (the same applies to the other image forming units  12 M,  12 C,  12 K). 
         [0039]    The first transfer bodies  32 Y,  32 M,  32 C,  32 K are provided at the portions of contact where each photoreceptor  18 Y,  18 M,  18 C,  18 K is in contact with the intermediate transfer belt  26 . While the intermediate transfer belt  26  circulates in the counterclockwise direction in  FIG. 1 , a Y-color image from the photoreceptor  18 Y of the image forming unit  12 Y of the uppermost level is transferred. When the transfer region arrives at the image forming unit  12 M of the second level, an M-color image is transferred onto the same transfer region. Next, a C-color image is transferred onto the same transfer region at the third level image forming unit  12 C. Lastly, a K-color image is transferred onto the same transfer region at the image forming unit  12 K of the lowermost level. As a result, images of four colors (YMCK) are layered on each other. 
         [0040]    The toner image on the intermediate transfer belt  26  where the four colors were layered moves to the secondary transfer portion due to the intermediate transfer belt  26 . 
         [0041]    At the storage container  38 , the paper  36  of the topmost layer is taken out by the paper-retrieving mechanism  39  so as to be synchronized with this movement and the paper  36  is conveyed by the paper-sending conveyer  37  to the secondary transfer portion. 
         [0042]    At the secondary transfer portion, the intermediate transfer belt  26  and the second transfer body  42  nips the paper  36  at a preset pressure while conveying the paper  36 . During conveyance of this paper  36 , four colors are superimposed at the first transfer portions, and the transferred full-color image is transferred to the paper  36 . 
         [0043]    The paper  36  is sent to the fixing unit  46  while being guided by the main conveying unit  40 . At the fixing unit  46 , the paper  36  is press-processed and heat-processed by the pressing roller  50  and the heat roller  48  and is discharged to the discharge section  54  formed at the upper surface of the case  34  by the discharge conveying section  52 . 
         [0044]    Here, the image forming device  14  of the present exemplary embodiment is provided with a function that makes the paper  36  circulate inside the case  34 , i.e., it is provided with the circulating conveying unit  60 . The paper  36  is made to circulate by this circulating conveying unit  60 .
   (1) Form image on the front and back sides of the paper  36 .   (2) Extend time until image formation is performed on the other side of the paper  36  after fixing on one side and then cooled.   
 
         [0047]    When the above-described instruction (1) or (2) is sent to the image forming device  14 , the paper  36  is conveyed by the main conveying unit  40  at the image forming device  14  and this paper  36  that was fixed at the fixing unit  46  is guided to a circulating conveying unit  60  that differs from the paper-sending conveyer  37 . 
         [0048]    Due to this, the paper  36  is discharged to the discharge section  54 , the rear edge of the paper  36  is retained by the circulating conveying unit  60 , and the rear edge side that is being retained becomes the leading end and is the conveyed in the opposite direction. At this time, the paper  36  is sent to the secondary transfer portion again by the circulating conveying unit  60 . 
         [0049]    Namely, the paper is guided from main the conveying unit  40  to the circulating conveying unit  60  and the conveying path leading again to the main conveying unit  40  becomes the “O-type path” that is an endless conveying path. Furthermore, this “O-type path” is provided in the space  35  that is between the case  34  and the central portion of the case  34  where the parts that comprise each of the image forming units  12 Y,  12 M,  12 C,  12 K, the controller  16 , and the power source  17  are assembled. For this reason, the curvature radius when the paper  36 , conveyed on this “O-type path”, is bent may be large. 
         [0050]    Note that in the case of the above-described instruction (1), the paper  36  has an image transferred thereto at the second transfer portion, after which it is transferred to the main conveying unit  40 . In addition, in the case of the above-described instruction (2), the paper  36  passes through as is and is transferred to the main conveying unit  40 . 
         [0051]    Due to this, the paper  36  is conveyed by the main conveying unit  40 , passes through the fixing unit  46 , is guided to the discharge conveying section  52 , and is then discharged to the discharge section  54 . 
       ALTERNATE EXAMPLE 1 
       [0052]    Note that with the present exemplary embodiment, the structure is such that it uses the intermediate transfer body  26 , which is an endless belt-shaped body, and the images of each color transferred at the first transfer portions making are organized at the secondary transfer portion and transferred to the paper  36 . Nonetheless, as shown in  FIG. 2 , the device can be configured so that the endless belt-shaped form is made to be a paper conveying belt (combining with the conveying unit  40 ) that simply guides the conveyance of the paper  36 . In this case, images of each color are directly and consecutively layered on and transferred to the paper  36 . 
       ALTERNATE EXAMPLE 2 
       [0053]    As shown in  FIG. 3 , Alternate Example 2 has a structure such as that of Alternate Example 1, but wherein the storage container  38  is set vertically. The available space of the image forming device  14  is used for the vertically positioned storage container  38 . The image forming device one in which a laser diode is used as the light source for an optical scanning device that scans light beams in a main scanning direction, and, as in the above-described exemplary embodiment, the light source is an LPH  10 Y. 
         [0054]    In a structure with this vertically set type storage container  38  as in this Alternate Example 2, it is possible to use an intermediate transfer belt structure as an endless belt form that is separate from the conveying unit  40 . 
       ALTERNATE EXAMPLE 3 
       [0055]    As shown in  FIG. 4 , Alternate Example 3 has a structure where the storage container  38  is arranged at the front side of the image forming device  14 , in contrast to Alternate Example 2. 
         [0056]    In a structure with this vertically set type storage container  38  as in this Alternate Example 3, it is possible to use an intermediate transfer belt structure as an endless belt form that is separate from the conveying unit  40 . 
         [0057]    The foregoing description of the exemplary embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to practitioners skilled in the art. The exemplary embodiments were chosen and described in order to best explain the principles of the invention and its practical applications, thereby enabling others skilled in the art to understand the invention for various embodiments and with the various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents.