Abstract:
A fixing mechanism of an optical scanning device, the optical scanning device emitting a light beam and performing a scanning, the optical scanning device further being fixed to a frame at an external part, the optical scanning device further including a housing, and the fixing mechanism including: a penetration hole provided in the frame; and a protruding pin provided at both ends of the housing thereby forming a plurality of protruding pins, wherein at least one of the plurality of protruding pins is insertable to the penetration hole formed in the frame; and a biasing member biasing the housing in a direction.

Description:
[0001]    The present application claims priority on Japanese Patent Application No. 2010-078006, filed Mar. 30, 2010, the content of which is incorporated herein by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates to a fixing mechanism of an optical scanning device and an imaging forming apparatus. 
         [0004]    2. Description of the Related Art 
         [0005]    Conventionally, an optical scanning device, which has been one of the primary components of an image forming unit equipped in an image forming device such as a copier and a complex machine, comprises a housing such that a light beam is guided in an interior. This housing is supported by being fixed to a frame provided within a chassis of an image forming apparatus. 
         [0006]    According to an example of a fixing mechanism of an optical scanning device which has been suggested, a housing of the optical scanning device is screw-fastened using a standard pin such that a screw part is provided on a frame. 
         [0007]    However, a heat generating part such as a polygon motor, which scans a light beam, is stored inside the housing. Therefore, it is not possible to prevent the housing from deforming due to the heat generated by the heat generating part. When a deformation due to heat cannot be released due to the housing being completely screw-fastened to the frame, a significant, localized heat deformation occurs. When such a heat deformation occurs on the housing, the location of the scanning line may deviate, thereby causing a deterioration in the quality of printing. 
         [0008]    Further, according to the conventional housing, the housing of the optical scanning device is screw-fastened to the frame, as described above. As a result, the assembling operation cannot be performed efficiently. Further, there is a problem in that a staff member with specialized technical knowledge is required in order to exchange the optical scanning device. 
         [0009]    Considering the problems described above, the present invention aims to prevent a deviation in the position of a light beam caused by a heat deformation of a housing. At the same time, the present invention aims to make the assembling process easier such that a user may exchange the optical scanning device on his or her own. 
       SUMMARY OF THE INVENTION 
       [0010]    In order to achieve the above object, the present invention employs the following. 
         [0011]    Namely a fixing mechanism of an optical scanning device according to an aspect of the present invention is such that the optical scanning device emits a light beam and performs a scanning, the optical scanning device is fixed to a frame at an external part, the optical scanning device further includes a housing, and the fixing mechanism includes: a penetration hole provided in the frame; and a protruding pin provided at both ends of the housing thereby forming a plurality of protruding pins, and a biasing member biasing the housing in a direction. Here, at least one of the plurality of protruding pins is insertable to the penetration hole formed in the frame. 
         [0012]    Furthermore, an image forming apparatus according to an aspect of the present invention includes: an optical scanning device emitting a light beam and performing a scanning; an image supporting body creating an electrostatic latent image by being irradiated with the light beam; and an imaging device creating a toner image by developing the electrostatic latent image. Here, the optical scanning device is fixed by the fixing mechanism described in the previous paragraph. 
       EFFECT OF THE INVENTION 
       [0013]    According to the present invention, a position of a housing is determined, and the housing is supported by penetrating a protruding pin through a penetration hole, and, in this condition, the housing is biased in one direction by a biasing part. In other words, according to the present invention, the housing is not fixed rigidly to the frame. When a force is applied, which exceeds a biasing force received by the housing from the biasing part, a deformation of the housing or a change in the position of the housing are allowed. 
         [0014]    Therefore, according to the present invention, a localized heat deformation does not occur on the housing. Therefore, a deviation in the position of the scanning line does not occur. Further, it is possible to prevent the print quality from deteriorating. 
         [0015]    Moreover, according to the present invention, the position of the housing is determined, and the housing is supported by the biasing part biasing the housing in one direction. Therefore, when the housing is placed at an approximate position at the time of assembly, thereafter, the position of the housing may be determined precisely by the biasing force of the biasing part. Further, since the housing is not fixed rigidly to the frame, the housing may be easily detached as well. 
         [0016]    Therefore, according to the present invention, the operability of an assembling process of the optical scanning device is improved, so that a user may exchange the optical scanning device on his or her own without relying on a staff member with specialized technical knowledge. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a cross sectional diagram showing a skeletal configuration of a copying machine according to a first embodiment of the present invention. 
           [0018]      FIG. 2  is an upper surface diagram of a laser scanning unit comprised by a copying machine according to a first embodiment of the present invention. 
           [0019]      FIG. 3  is an enlarged cross sectional diagram along line X-X of  FIG. 2 . 
           [0020]      FIG. 4  is an upper surface diagram of a laser scanning unit comprised by a copying machine according to a second embodiment of the present invention. 
           [0021]      FIG. 5  is a perspective view including a side surface of a laser scanning unit comprised by a copying machine according to a third embodiment of the present invention. 
           [0022]      FIG. 6  is a perspective view including a laser scanning unit and a frame comprised by a copying machine according to a third embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Embodiment 
       [0023]    Hereinafter, a first embodiment of a fixing mechanism of an optical scanning device and an imaging forming apparatus according to the present invention is described with reference to the diagrams. In the drawings referred to below, the scaling of each component is changed as appropriate so that each component becomes a size which may be recognized. Further, in the description below, a copying machine is provided and described as an example of an image forming apparatus according to the present invention. 
         [0024]      FIG. 1  is a cross sectional diagram showing a skeletal configuration of a copying machine P according to the present embodiment. As shown in this diagram, the copying machine P according to the present embodiment comprises an image reading part  1 , which reads an image of a draft, and a printing part  2 , which makes a printout to a recording paper (recording medium) based on an image data that was read in. 
         [0025]    The image reading part  1  irradiates light to an image of a draft, and reads the image of the draft as an image data by receiving a reflected light. Thus, the image reading part  1  comprises a light receiving sensor and the like, which receives a light returning from the draft and a light source device which irradiates light to the draft, and thereby makes a conversion to an image data. 
         [0026]    The printing part  2  comprises a belt unit  6 , an image forming unit  7 , a paper feeding cassette  8 , a paper feeding tray  9 , a secondary transcription part  10 , a fixing part  11 , a paper ejection tray  12 , and a transportation path  13 . 
         [0027]    A toner, formed at the image forming unit  7 , is transcribed to the belt unit  6 . The belt unit  6  transports this transcribed toner. The belt unit  6  comprises an intermediary transcription belt  61 , to which a toner is transcribed from the image forming unit  7 , a driving roller  62  which bridges the intermediary transcription belt  61  and performs an endless transportation, a driven roller  63 , and a tension roller  64 . 
         [0028]    The intermediary transcription belt  61  is bridged by the driving roller  62 , the driven roller  63 , and the tension roller  64 . 
         [0029]    The driving roller  62  is connected to a driving part comprising a driving source such as a motor and the like. The driving roller  62  applies a gripping force with respect to the intermediary transcription belt  61 , and makes the intermediary transcription belt  61  run. 
         [0030]    The driven roller  63  is driven to rotate along with the rotation of the driving roller  62 . 
         [0031]    The tension roller  64  is a type of a driven roller which is driven to rate along with the rotation of the driving roller  62 . The tension roller  64  comprises a spring mechanism and applies a tension to the intermediary transcription belt  61 . 
         [0032]    Further, the belt unit  6  also comprises a cleaning part, which is not diagrammed. The cleaning part is configured to remove a toner and the like which has been left in the intermediary transcription belt  61 . 
         [0033]    The image forming unit  7  is provided corresponding to each of the colors yellow (Y), magenta (M), cyan (C), and black (BK). The image forming unit  7  forms a toner image for each color. In addition, these image forming units  7  are aligned along the intermediary transcription belt  61 . 
         [0034]    Each image forming unit  7  comprises a photoreceptor  71  being an example of an image supporting body, a charging device  72 , a laser scanning unit (optical scanning device)  73 , an imaging device  74 , a primary transcription roller  75 , a cleaning device  76 , and a neutralization apparatus which is not diagrammed. 
         [0035]    The shape of the photoreceptor  71  is set to be cylindrical. A electrostatic image and a toner image based on the electrostatic image are formed on the surrounding surface of the photoreceptor  71 . The charging device  72  is placed opposite to the photoreceptor  71 , and charges the surrounding surface of the photoreceptor  71 . The laser scanning unit  73  scans a laser beam irradiated based on the image data, in a printing form, over a surrounding surface of the charged photoreceptor  71 . The imaging device  74  forms a toner image on the surrounding surface of the photoreceptor  71  based on an electrostatic latent image by supplying a toner with respect to the surrounding surface of the photoreceptor  71 . The primary transcription roller  75  is placed opposite to the photoreceptor  71 , with the intermediary transcription belt  61  placed in between. The primary transcription roller  75  performs a primary transcription of the toner image, which was formed on the photoreceptor  71 , to the intermediary transcription belt  61 . The cleaning device  76  removes a toner remaining on top of the photoreceptor  71  after the primary transcription. 
         [0036]    The paper feeding cassette  8  may be pulled out freely with respect to the main body of a device. The paper feeding cassette  8  stores a recording paper. The paper feeding tray  9  may be opened and closed with respect to the main body of the device. The paper feeding cassette stores a recording paper. 
         [0037]    The secondary transcription part  10  performs a secondary transcription of an image, formed on the intermediary transcription belt  61 , onto a recording paper. The secondary transcription part  10  comprises a driving roller  62  which drives the intermediary transcription belt  61 , and a secondary transcription roller  10   a  which is placed opposite to the driving roller  62  with the intermediary transcription belt  61  being placed in between. 
         [0038]    The fixing part  11  fixes the toner image onto a recording paper, which has undergone a secondary transcription onto the recording paper. The fixing part  11  comprises a heating roller which fixes the toner image onto the recording paper by applying pressure and by providing heat. 
         [0039]    The transportation path  13  comprises a pickup roller  13   a , which transports a recording paper out from the paper feeding cassette  8 , a paper feeding roller  13   b , which transports a recording paper, and a paper ejection roller  13   c  which ejects the recording paper or paper to the paper ejection tray  12 . 
         [0040]    The copying machine P according to the present embodiment, which is configured as described above, obtains an image data from the image reading part  1 . Further, the printing part  2  performs a printout to the recording paper based on the image data. 
         [0041]    Next, a laser scanning unit (optical scanning device)  73  of the copying machine P according to the present embodiment is described using  FIG. 2 . This  FIG. 2  is a diagram showing a skeletal configuration of the laser scanning unit, and shows a condition in which the upper cover is removed. 
         [0042]    Since each laser scanning unit  73  is configured similarly, only one laser scanning unit  73  is described in the following explanation. 
         [0043]    The laser scanning unit  73  comprises a housing  200 . This housing  200  comprises plastics material. The interior of the housing  200  is a hollow body comprising a space with a predetermined volume. Furthermore, inside the housing, a light beam generating device, a polygon mirror, a polygon motor, an optical element, and the like are provided. According to the laser scanning unit  73 , a light beam emitted from the light beam generating device is led inside the housing, and emitted. Thus, the light beam scans over the photoreceptor  71 . 
         [0044]    Incidentally, an electrostatic latent image is formed on the photoreceptor  71  due to the light beam emitted by the laser scanning unit  73  being irradiated to the photoreceptor  71 . 
         [0045]    Hereinafter, a fixing mechanism  300  of the laser scanning unit  73  is described.  FIG. 2  shows a condition of the laser scanning unit  73  shown in  FIG. 1 , such that the laser scanning unit  73  is provided between a pair of frames F 1 , F 2  (not diagrammed in  FIG. 1 ) positioned at the front and back sides of  FIG. 1 . The pair of frames F 1 , F 2  are provided parallel to each other inside the chassis of the copying machine P, with a predetermined distance constantly being provided between the frames F 1 , F 2 . 
         [0046]    The assembling of the housing  200  of the laser scanning unit  73  to the frames F 1 , F 2  is performed using three protruding pins  100 - 102 , three penetration holes  103 - 105 , and a spring member  106 . 
         [0047]    In other words, the fixing mechanism  300  of the laser scanning unit  73  according to the present embodiment comprises the protruding pins  100 - 102 , the penetration holes  103 - 105 , and the spring member  106 . 
         [0048]    Among the three protruding pins  100 - 102 , two protruding pins  100 ,  101  are provided on one side surface of the housing  200 , with a predetermined distance being provided between the protruding pins  100 ,  101 . The remaining protruding pin  102  is provided on the other side surface of the housing  200  so that the axis of the protruding pin  102  coincides with the axis of one of the two protruding pins  100  or  101 . (In the example which is shown in the diagram, the protruding pin  102  is coaxial with the protruding pin  100 .) 
         [0049]    The length of the three protruding pins  100 - 102  is set so that all of the protruding pins  100 - 102  may be inserted inside the penetration holes  103 - 05 . Moreover, the length of the protruding pin  102  is set so that, when the protruding pins  100 ,  101  are inserted furthest into the penetration holes  103 ,  104 , the protruding pin  102  sticks out from the penetration hole  105 . In addition, the radius of the protruding pins  100 ,  101  is set to be smaller than the radius of the penetration holes  103 ,  104 , so that the protruding pins  100 ,  101  may be inserted from a slanted direction into the penetration holes  103 ,  104 . 
         [0050]    Incidentally, a configuration is possible in which at least one of the penetration holes  103 ,  104  is shaped as an ellipse which is long in the upper and lower directions, so that the protruding pins  100 ,  101  may be inserted from a slanted direction. 
         [0051]    Here, the protruding pin  102  is provided to be coaxial with the protruding pin  100 . However, the protruding pin  102  may be provided to be coaxial with the protruding pin  101 . Furthermore, two protruding pins may be provided so as to be coaxial with the two protruding pins  100 ,  101 . 
         [0052]    Among the three penetration holes  103 - 105 , two penetration holes  103 ,  104  are provided on the frame F 1  at a position corresponding to the protruding pins  100 ,  101 . The remaining penetration hole  105  is provided on the frame F 2  at a position corresponding to the protruding pin  102 . The relationship between the penetration holes  103 ,  104 , the protruding pins  100 ,  101 , the penetration hole  105 , and the protruding pin  102  is determined so that each protruding pin may be inserted easily into each penetration hole, and so that the inserted penetration pin does not become loose. 
         [0053]    The spring member  106  corresponds to the biasing part according to the present invention. As shown in  FIG. 3 , the spring member  106  comprises a U-shaped board spring, and is provided between one side surface of the housing  200  and the frame F 1 , and between the protruding pins  100 ,  101 . A housing  200  side of the spring member  106  is fixed to the housing  200 . An upper end part of the opposing side is formed in an inverse-U form. A configuration is made so that the inverse-U-shaped part may be inserted to an upper end part of the frame F 1 . 
         [0054]    When the spring member  106  is provided between the housing  200  and the frame F 1 , as shown in  FIG. 2 , a compression is made so that the housing is biased towards the direction of the frame F 2  (one direction). 
         [0055]    Thus, due to the biasing force of the spring member  106 , the housing  200  is pressed in the direction of the frame F 2 . As a result, the positioning of the laser scanning unit  73  is made. 
         [0056]    When the laser scanning unit  73  is installed, the protruding pins  100 ,  101  are first inserted into the insertion holes  103 ,  104  from an obliquely upward direction. The insertion holes  103 ,  104  are formed in the frame F 1 . At this time, by pushing the housing  200  hard, the spring member  106  is greatly compressed. As a result, the protruding pins  100 ,  101  may be inserted into the penetration holes  103 ,  104  to the furthest extent. Next, the laser scanning unit  73  is laid down so that the protruding pin  102  faces the penetration hole  105  of the frame F 2 . Thereafter, the force pushing the housing  200  is released. Thus, due to the restoring force of the spring member  106 , the protruding pin  102  is inserted into the penetration hole  105 . As a result, the laser scanning unit  73  is positioned and supported as shown in  FIG. 2 . 
         [0057]    In this way, according to the laser scanning unit  73  based on the present embodiment, the protruding pins  100 ,  101  are first inserted to the penetration holes  103 ,  103  to the furthest extent from an obliquely upward direction. Thereafter, the housing  200  is laid down and is moved towards a direction in which the protruding pins  100 ,  101  move out from the penetration holes  103 ,  104 . Due to this switch back movement, the housing is fixed with respect to the frames F 1 , F 2 . 
         [0058]    Meanwhile, when the laser scanning unit  73  is taken out, the spring member  106  is further compressed, so that the protruding pin  102  is pulled out from the penetration hole  105 . Thereafter, the housing  200  is tilted towards the front side, and the laser scanning unit  73  is removed by pulling out the protruding pins  100 ,  101  from the penetration holes  103 ,  104 . 
         [0059]    According to the fixing mechanism  300  of the laser scanning unit  73  based on the present embodiment as described above, the protruding pins  100 - 102  are inserted into the penetration holes  103 - 105 , and in this condition, the housing  200  is biased in one direction with the spring member  106 . In this way, the positioning and the support of the housing  200  are made. In other words, according to the fixing mechanism  300  of the laser scanning unit  73  based on the present embodiment, the housing  200  is not rigidly fixed with respect to the frames F 1 , F 2 . When a force, which is greater than the biasing force received by the housing  200  from the spring member  106 , is applied, the housing  200  is allowed to deform or change its position. 
         [0060]    Therefore, according to the fixing mechanism  300  of the laser scanning unit  73  based on the present embodiment, localized heat deformation does not occur on the housing  200 . Therefore, the location of the scanning line does not deviate. Thus, it is possible to prevent a deterioration in the quality of printing. 
         [0061]    In addition, according to the fixing mechanism  300  of the laser scanning unit  73  based on the present embodiment, the housing  200  is positioned and supported due to the housing  200  being biased in one direction by the spring member  106 . As a result, as long as the housing  200  is placed in an approximately correct position at the time of assembling, thereafter, the housing  200  may be positioned at a correct position due to the biasing force of the spring member  106 . Further, since the housing  200  is not fixed rigidly to the frames F 1 , F 2 , the housing  200  may be easily detached as well. 
         [0062]    Therefore, according to the present invention, the operability of an assembling process of the optical scanning device is improved, so that a user may exchange the optical scanning device on his or her own without relying on a staff member with specialized technical knowledge. 
       Second Embodiment 
       [0063]    Hereinafter, a second embodiment of the present invention is described with reference to  FIG. 4 . In this description of the second embodiment, the same reference numerals are used for the same components described in the first embodiment. These overlapping components are not described in the second embodiment to prevent redundancy. 
         [0064]    A fixing mechanism  400  of a laser scanning unit  73  according to the second embodiment comprises protruding pins  100   a ,  101   a , and  102   a , which correspond to the protruding pins  100 ,  101 , and  102  in the first embodiment; penetration holes  103   a ,  104   a , and  105   a , which correspond to the penetration holes  103 ,  104 , and  105 ; and a biasing mechanism  500  (biasing part). 
         [0065]    Insertion holes  100   b ,  101   b  are provided respectively to the protruding pins  100   a ,  101   a  in a central axial direction. Further, in the present embodiment, the length of the protruding pins  100   a ,  101   a  is set so that, in a condition in which the protruding pin  102   a  is inserted in the penetration hole  105   a  to the furthest extent, the tip end does not reach the penetration holes  103   a ,  104   a.    
         [0066]    In addition, the radius of the protruding pin  102   a  is set to be smaller than the radius of the penetration hole  105   a , so that the protruding pin  102   a  may be inserted from an obliquely upward direction into the penetration hole  105   a . Incidentally, a configuration is possible in which the penetration hole  105   a  is shaped as an ellipse which is long in the upper and lower directions, so that the protruding pin  102   a  may be inserted from a slanted direction. 
         [0067]    The biasing mechanism  500  biases the housing  200  in a direction towards the frame F 2  (one direction). The biasing mechanism  500  comprises a spring member  106   a , a plate member  107 , and a positioning pin  108 ,  109 . 
         [0068]    The spring member  106   a  is a tension spring. One end of the spring member  106   a  is fixed to the frame F 1 , while the other end is fixed to one surface of the plate member  107 . 
         [0069]    The length of the plate member  107  in the longitudinal direction is determined so as to be slightly longer than the distance between the protruding pins  100   a ,  101   a . Further, the plate member  107  is constantly biased by the  106   a  so that the plate member  107  is pulled towards the frame F 1 . 
         [0070]    The positioning pins  108 ,  109  are both provided on the plate member  107 . The positioning pins  108 ,  109  are placed so as to protrude in the direction of the protruding pins  100   a ,  101   a  at a position so as to face the protruding pins  100   a ,  101   a  respectively. 
         [0071]    A protruding part  108   a ,  109   a  is provided at a tip of the positioning pins  108 ,  109  respectively, so that the protruding parts  108   a ,  109   a  may be inserted into the insertion holes  100   b ,  101   b  provided in the protruding pins  100   a ,  101   a.    
         [0072]    Further, these positioning pins  108 ,  109  are configured so that the positioning pins  108 ,  109  may be inserted into the penetration holes  103   a ,  104   a  provided at the same place as the penetration holes  103 ,  104  in the first embodiment (see  FIG. 4 ). 
         [0073]    When the laser scanning unit  73  is installed, the protruding pin  102   a  is first inserted into the insertion hole  105   a  from an obliquely upward direction. The insertion hole  105   a  is formed in the frame F 2 . Next, while the plate member  107  is pulled, the laser scanning unit  73  is laid down so that the insertion holes  100   b ,  101   b  provided in the protruding pins  100   a ,  101   a  face the protruding members  108   a ,  109   a  of the positioning pins  108 ,  109 . Next, the plate member  107  is returned, and the protruding members  108   a ,  109   a  are inserted into the insertion holes  100   b ,  101   b . At the same time, the positioning pins  108 ,  109  are inserted into the penetration holes  103   a ,  104   a.    
         [0074]    Therefore, as shown in  FIG. 4 , the laser scanning unit  73  is positioned and supported. 
         [0075]    Meanwhile, when the laser scanning unit  73  is taken out, the protruding members  108   a ,  109   a  are pulled out from the insertion holes  100   b ,  101   b  by pulling plate member  107 . After the laser scanning unit  73  is tilted towards the front side, the protruding pin  102   a  is pulled out from the penetration hole  105   a . In this way, the laser scanning unit  73  is removed. 
         [0076]    According to the fixing mechanism  400  of the laser scanning unit  73  based on the present embodiment as described above, the protruding pin  102   a  is inserted in the penetration hole  105   a . In this condition, the housing  200  is biased in one direction by the biasing mechanism  500 . Thus, the housing  200  is positioned and supported. IN other words, according to the fixing mechanism  400  of the laser scanning unit  73  based on the present embodiment as described above, the housing  200  is not rigidly fixed with respect to the frames F 1 , F 2 . When a force, which is greater than the biasing force received by the housing  200  from the biasing mechanism  500 , is applied, the housing  200  is allowed to deform or change its position. 
         [0077]    Therefore, according to the fixing mechanism  400  of the laser scanning unit  73  based on the present embodiment, localized heat deformation does not occur on the housing  200 . Therefore, the location of the scanning line does not deviate. Thus, it is possible to prevent a deterioration in the quality of printing. 
         [0078]    In addition, according to the fixing mechanism  400  of the laser scanning unit  73  based on the present embodiment, the housing  200  is positioned and supported due to the housing  200  being biased in one direction by the biasing mechanism  500 . As a result, as long as the housing  200  is placed in an approximately correct position at the time of assembling, thereafter, the housing  200  may be positioned at a correct position due to the biasing force of the biasing mechanism  500 . Further, since the housing  200  is not fixed rigidly to the frames F 1 , F 2 , the housing  200  may be easily detached as well. 
         [0079]    Therefore, according to the fixing mechanism  400  of the laser scanning unit  73  based on the present embodiment, the operability of an assembling process of the optical scanning device is improved, so that a user may exchange the optical scanning device on his or her own without relying on a staff member with specialized technical knowledge. 
       Third Embodiment 
       [0080]    Next, a third embodiment of the present invention is described with reference to  FIGS. 5 and 6 . Incidentally, in this description of the third embodiment, the same reference numerals are used for the same components described in the first embodiment. These overlapping components are not described in the second embodiment to prevent redundancy. 
         [0081]    According to a fixing mechanism  600  of a laser scanning unit  73  based on the third embodiment, the frame F 2  side is configured similarly to the first embodiment, and therefore is not described here. 
         [0082]    Moreover, the fixing mechanism  600  of the laser scanning unit  73  based on the present embodiment comprises a biasing mechanism  700  (biasing part) in addition to the configuration at the frame F 2  side (the protruding pin  102  and the penetration hole  105 ), as shown in  FIG. 5 . Incidentally, the frame F 1  is not shown in  FIG. 5 . 
         [0083]    The biasing mechanism  700  biases and pulls in the housing  200  of the laser scanning unit  73  towards the frame F 1  side. The biasing mechanism  700  comprises a plate member  701 , a header pin  702 , a spring member  703 , and a screw  704 . 
         [0084]    The plate member  701  is fixed to an outer side of the frame F 1  (an opposite side compared to a side at which the laser scanning unit  73  is placed), as shown in  FIG. 6 , so that the plate member  701  is exposed from an opening provided on the frame F 1 . 
         [0085]    As shown in  FIG. 5 , the plate member  701  comprises a fitting hole  701   a , into which the protruding pin  100  of the laser scanning unit  73  is fitted, and a fitting hole  701   b , into which the protruding pin  101  is fitted. A plurality of protruding parts  701   c  are provided (in the present embodiment, three protruding parts are provided) at an inner wall surface of the fitting holes  701   a ,  701   b . The positions of the protruding pins  100 ,  101  are determined as the peripheral surface of the protruding pins  100 ,  101  contacts the protruding parts  701   c.    
         [0086]    Furthermore, an insertion hole  701   d  is provided at approximately a center portion of the plate member  701 . The insertion hole  701   d  is used to pull the header pin  702  from the outer side of the frame F towards the inner side. Incidentally, the radius of the insertion hole  701   d  is set to be smaller than the head of the header pin  702 . 
         [0087]    Further, according to the present embodiment, an insertion hole  200   a  is also provided with respect to the housing  200  of the laser scanning unit  73  in order to insert the tip (an opposite side compared to the head) of the header pin  702 . Further, the tip of the header pin  702  is placed as shown in  FIG. 5 , passing through the insertion hole  701   d  and the insertion hole  200   a  from the outer side. The tip of the header pin  702  is placed in an interior part of the housing  200 . The tip of the header pin  702  is screwed together with a nut (not diagrammed) which has a larger radius compared to the insertion hole  200   a . This header pin  702  is fixed to the housing  200  due to the nut being latched to the housing  200 . 
         [0088]    The spring member  703  is provided between the head of the header pin  702  and the plate member  701 . The spring member  703  biases the header pin  702  towards the outer side (a side moving away from the plate member  701 ). 
         [0089]    In this way, since the header pin  702  is biased towards the outer side, the housing fixed with the header  702  is biased and pulled towards the frame F 1  side. 
         [0090]    The screw  704  is a component positioning and fixing the plate member  701  with respect to the frame F 1 . In the present embodiment, two screws are provided. According to the fixing mechanism  600  of the laser scanning unit  73  as described above, the housing  200  is positioned and supported due to the biasing mechanism  700  biasing the housing  200  in one direction. In other words, according to the fixing mechanism  600  of the laser scanning unit  73  based on the present embodiment, the housing  200  is not rigidly fixed with respect to the frames F 1 , F 2 . When a force, which is greater than the biasing force received by the housing  200  from the spring member  703 , is applied, the housing  200  is allowed to deform or change its position. 
         [0091]    Therefore, according to the fixing mechanism  600  of the laser scanning unit  73  based on the present embodiment, localized heat deformation does not occur on the housing  200 . Therefore, the location of the scanning line does not deviate. Thus, it is possible to prevent a deterioration in the quality of printing. 
         [0092]    In addition, according to the fixing mechanism  600  of the laser scanning unit  73  based on the present embodiment, the housing  200  is positioned and supported due to the housing  200  being biased in one direction by the spring member  703 . As a result, as long as the housing  200  is placed in an approximately correct position at the time of assembling, thereafter, the housing  200  may be positioned at a correct position due to the biasing force of the spring member  703 . Further, since the housing  200  is not fixed rigidly to the frames F 1 , F 2 , the housing  200  may be easily detached as well. 
         [0093]    Therefore, according to the fixing mechanism  600  of the laser scanning unit  73  based on the present embodiment, the operability of an assembling process of the optical scanning device is improved, so that a user may exchange the optical scanning device on his or her own without relying on a staff member with specialized technical knowledge. 
         [0094]    While a preferred embodiment of the present invention has been described above with reference to the attached figures, it should be understood that these are exemplary of the invention and are not to be considered as limiting the present invention. Additions, omissions, substitutions, and other modifications can be made without departing from the scope of the present invention. 
         [0095]    For instance, in the embodiment described above, a configuration was described in which the laser scanning unit  73 , which is an example of the optical scanning device according to the present invention, is mounted on a copying machine being one of the image forming devices. 
         [0096]    However, the optical scanning device according to the present invention is not limited to this configuration. Instead of an image forming device such as a copying machine, the optical scanning device may be mounted on devices such as a measuring equipment, an inspection equipment, and the like.