Abstract:
An image forming apparatus includes an upper body, an image reading device that is mounted in the upper body, a lower body that is placed under the upper body, an image forming device that is mounted in the lower body, a hinge member that connects the upper body and the lower body, at least one groove that is formed on the lower body, at least one link member that is connected to the upper body at one end and connected to the groove at the other end, and at least one elastic member that is connected to the lower body at one end and the link member at the other end. The groove has a first range where a moment to pivot the upper body to the close position is generated.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of Invention  
           [0002]    The invention relates to an image forming apparatus that includes an upper body and a lower body and, more particularly to, an opening and closing movement of the upper body.  
           [0003]    2. Description of Related Art  
           [0004]    A known image forming apparatus includes an image forming device that forms an image on a recording medium and an image reading device that reads an image on the original document. The image forming apparatus also includes an upper body and a lower body. The upper body is mounted on the lower body and connected to the lower body by a hinge. The upper body is pivoted about the hinge as a supporting point toward an open position and a close position with respect to the lower body. The image reading device is mounted in the upper body and the image forming device is mounted in the lower body. The image forming apparatus further includes a spring interposed between the upper body and the lower body. The spring urges the upper body toward the open position while an amount of deformation of the spring increases when the upper body is moved toward the close position. Strength of the spring is adjusted to a degree that the upper body is prevented from moving toward the close position by its own weight when the upper body is moved to the open position.  
           [0005]    However, because the amount of deformation of the spring increases when the upper body is moved to the close position, a force greater than that required supporting the weight of the upper body is stockpiled to the spring. As a result, a stress that the spring imposes on the upper body becomes great, and a bigger force is required as the upper body is brought closer to the close position, thereby worsening the convenience of operation. Further the upper body is normally positioned in the close position and subjected to stress of the spring, which may cause deformation in the upper body.  
         SUMMARY OF THE INVENTION  
         [0006]    The invention provides an image forming apparatus that improves a closing operation of an upper body and protects the upper body from an excessive stress.  
           [0007]    According to one aspect of the invention, an image forming apparatus includes an upper body, an image reading device that is mounted in the upper body, a lower body that is placed under the upper body, an image forming device that is mounted in the lower body, a hinge member that connects the upper body and the lower body, at least one groove that is formed on the lower body, at least one link member that is connected to the upper body at one end and connected to the groove at the other end, and at least one elastic member that is connected to the lower body at one end and the link member at the other end. The image reading device reads an image on an original document. The image forming device forms the image on a recording medium. The upper body is pivoted about the hinge member between an open position where the upper body is open with respect to the lower body and a close position where the upper body is closed with respect to the lower body. The link member slides in the groove at the other end. The elastic member is deformed when the link moves together with the upper body, and an amount of deformation of the elastic member increases when the upper body is moved from the open position to the close position. The groove has a first range where a moment to pivot the upper body to the close position is generated.  
           [0008]    Various moments are generated to pivot the upper body in the image forming apparatus, such as a moment to pivot the upper body toward the close position by its own weight, and a moment to pivot the upper body toward the open position by a force exerted on the upper body via an elastic member and a link member. The moment to pivot the upper body toward the close position is generated when a sum of all moments acting on the upper body is a value by which the upper body is pivoted toward the close position. The moment to pivot the upper body toward the open position is generated when the sum of all moments acting on the upper body is a value by which the upper body is pivoted toward the open position.  
           [0009]    The moment to pivot the upper body toward the close position, which is generated by the weight of the upper body, varies when a positional relationship between a center of rotation of the upper body and a center of gravity of the upper body changes as the upper body is pivoted. However, the moment to pivot the upper body toward the close position can be specified if a rotational angle of the upper body is determined. The moment to pivot the upper body toward the open position, which is generated by a force acting on the upper body via the link member in accordance with a load of the elastic member, varies according to the center of rotation of the upper body, a connecting point between the upper body and the link member, a contact point between the link member and the groove, and an amount of deformation of the elastic member. However, the moment to pivot the upper body toward the open position can be regulated by changing the shape of the groove so as to optimize the contact point between the link member and the groove and a contact angle of each member at the contact point. In the image forming apparatus, the shape of the groove is determined in such a manner that the moment to pivot the upper body toward the close position is generated, based on the moment generated by the weight of the upper body. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    An embodiment of the invention will be described with reference to the following figures wherein:  
         [0011]    [0011]FIG. 1 is a perspective view of a laser printer according to an embodiment of the invention;  
         [0012]    [0012]FIG. 2 is a perspective view of the laser printer when an upper body is in an open position;  
         [0013]    [0013]FIG. 3 is a perspective view of a movable member of the laser printer;  
         [0014]    [0014]FIG. 4A is a partial rear view of the laser printer when the upper body is in a close position;  
         [0015]    [0015]FIG. 4B a sectional view of the laser printer when the upper body is in the close position;  
         [0016]    [0016]FIG. 5 is a schematic illustration of a cam groove of the laser printer according to the embodiment of the invention;  
         [0017]    [0017]FIG. 6 is a schematic illustration of a cam groove of the laser printer according to another embodiment of the invention;  
         [0018]    [0018]FIG. 7 is a schematic illustration of a cam groove of the laser printer according to yet another embodiment;  
         [0019]    [0019]FIG. 8 is a partial sectional view of a link member and a spring of the laser printer when the upper body is in the close position;  
         [0020]    [0020]FIG. 9 is a partial sectional view of an engaging portion and an engaged portion of the laser printer;  
         [0021]    [0021]FIG. 10 is a sectional view of the link member and the spring of the laser printer when the upper body is in the open position;  
         [0022]    [0022]FIG. 11 is a sectional view of the laser printer when the upper body is in the open position;  
         [0023]    [0023]FIG. 12A is a partial sectional view of an engaging portion according to another embodiment;  
         [0024]    [0024]FIG. 12B is a partial sectional view of an engaging portion according to yet another embodiment; and  
         [0025]    [0025]FIG. 13 is a sectional view of a laser printer when an upper body is in a close position according to another embodiment. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0026]    As shown in FIG. 1, a laser printer  1  with an image scanner (hereinafter called as the printer  1 ) includes a laser printing mechanism  1   a  mounted in a lower body  3  and an image scanner mechanism  1   b  mounted in an upper body  5 . The lower body  3  and the upper body  5  are connected by hinges  7  that are provided apart on the backside of the printer  1 . When the upper body  5  is pivoted upward about the hinges  7  as a supporting point, the upper body  1  moves toward an open position as shown in FIG. 2. When the upper body  5  is pivoted downward about the hinges  7 , the upper body  5  moves toward a close position as shown in FIG. 1. An operating panel  9  is provided at the front side of the printer  1 .  
         [0027]    The laser printing mechanism la is structured where an image is formed on a recording sheet supplied from a sheet tray  11  provided at the backside of the printer  1  and the recording sheet is ejected from a discharge portion  13  provided at the front side of the printer  1 . A pullout discharge tray  15  is provided under the discharge portion  13  to receive recorded sheets discharged from the discharge portion  13 .  
         [0028]    The image scanner mechanism  1   b  is of a flat bed type and includes a line type image sensor that moves along a platen glass (not shown) to read an image from an document placed on the platen glass.  
         [0029]    An automatic document feeder (hereinafter “ADF”) unit  17  is provided at the left side of the upper body  5 . The ADF unit  17  is structured to feed plural documents in order into the image scanner mechanism  1   b  to read images therefrom. While documents are supplied one by one from a document feeding tray  21  into the ADF unit  17 , the image sensor becomes stationary and each document is sent over the image sensor to be scanned, so that image data can be obtained. Then the document is discharged from the ADF unit  17  and placed on a discharge tray  19 .  
         [0030]    In the laser printing mechanism la, recording sheets are fed in a direction from rear to front of the printer  1 . In the image scanner mechanism  1   b , the image sensor moves in a lengthwise direction from left to right of the printer  1 . The two directions are arranged perpendicularly viewed from the top of the printer. An upper portion  3   a  of the lower body  3  protrudes outwardly from a lower portion  3   b  thereof and has the same size as the upper body  5  relative to a lengthwise moving direction of the image sensor. An impactive force to be generated when something comes into collision with the printer  1  is to be received by both the upper body  5  and the lower body  3 . Thus, the image scanner mechanism  1   b  resists damage as compared with a structure where the upper body  5  only protrudes outwardly from the lower body  3 . A stepped portion  3   c  is formed between the upper portion  3   a  and the lower portion  3   b  of the lower body  3  at each side. It is convenient to hold the printer  1  because the printer  1  can be supported manually from underneath at the stepped portion  3   c.  The sheet tray  11  is disposed in a position such that it does not conflict with the upper body  5  when the upper body  5  is pivoted upward about the hinges  7  as the supporting point. The sheet tray  11  does not interfere with replacement of the cartridge  61 . Furthermore, the sheet tray  11  does not get damaged even if the upper body  5  is excessively pivoted toward the open position.  
         [0031]    The hinges  7  are provided on the back of the lower body  3  and upper body  5  so as to protrude rearward, and placed on both sides of the sheet tray  11  so as not to interfere with the sheet tray  11 . As the hinges  7  do not interfere with the sheet tray  11 , the sheet tray  11  can be arranged inclined. By inclining the sheet tray  11 , the convenience of operation for replenishing recording sheets into the sheet tray  11  can be increased.  
         [0032]    As shown in FIG. 2, a movable member  23  is interposed between the lower body  3  and the upper body  5 . The movable member  23  is movably connected to the lower body  3  and upper body  5 .  
         [0033]    As shown in FIG. 3, the movable member  23  is provided with a pair of link members  25  and a bridge  27  bridging the link members  25 , which are integrally formed into one body by molding. However, the movable member  23  can include only one link member  25  provided with or without a bridge  27 .  
         [0034]    Each of the link members  25  has a pair of walls  25   a ,  25   b , which are formed parallel with each other. A cylindrical rotational shaft  31  and a cylindrical cam follower  33  are mounted on each wall  25   b  facing outward so as to protrude therefrom.  
         [0035]    As shown in FIG. 4, the rotational shaft  31  is rotatably mounted to a bearing  35  of the upper body  5 . The cam follower  33  is inserted into a cam groove  37  formed in the lower body  3 . A spring  39  is connected to each link member  25  between the walls  25   a ,  25   b . The walls  25   a ,  25   b  prevent the spring  39  from being touched. The spring  39  is stretched between the lower body  3  and each link member  25 , and not connected to the upper body  5 . Thus, the upper body  5  is not deformed by the action of the spring  39 .  
         [0036]    As shown in FIGS. 1 and 4, the bridge  27  also serves as a part of exterior appearance when the upper body  5  is in the close position. The bridge  27  has a centermounted engaged portion  41 . The engaged portion  41  and the engaging portion  43  of the upper body  5  constitute a lock mechanism. When the engaging portion  43  engages with the engaged portion  41 , the upper body  5  is locked with the lower body  3 . An operating lever  45  is integrally formed with the engaging portion  43  by molding. When the operating lever  45  is pulled toward the front side of the printer  1  (in the direction of the arrow A in FIG. 9), the engagement between the engaging portion  43  and the engaged portion  41  is released to unlock the upper body  5 . Thereby, when the upper body  5  is pulled upward, the upper body  5  is pivoted toward the open position as shown in FIG. 10. The engaging portion  43  and the operating lever  45  are normally urged in a direction to engage with the engaged portion  41  by a resilient force generated by the spring  47 .  
         [0037]    As shown in FIG. 5 , the cam groove  37  has a first range  37   a  , a second range  37   b , and a third range  37   c . The first range  37   a  is provided to the front of the printer  1 . In the first range  37   a  , a resultant moment acting on the upper body  5  is exerted in a direction to close the upper body  5 . The second range  37   b  is provided to the rear of the printer  1 . In the second range  37   b , the resultant moment acting on the upper body  5  is exerted in a direction to open the upper body, contrary to the first range  37   a . The third range  37   c  is provided in a position continuously connecting the first range  37   a  and the second range  37   b . In the third range  37   c , a direction of the resultant moment acting on the upper body  5  is gradually changed.  
         [0038]    A force F produced by the weight of the upper body  5  acts on the rotational shaft  31 . The force F imposed on the rotational shaft  31  acts on the cam groove  37  via the link member  25  and the cam follower  33 . A force f is a resultant force of a force fx, which is a load of the spring  39 , and a force fy, which is a resistance acting vertically, generated at a contact point between the cam follower  33  and the cam groove  37 . As the link member  25  is urged in a specific direction by the spring  39 , the force f acts on the cam groove  37  via the cam follower  33 .  
         [0039]    The force F varies into force F 1 , F 2 , or F 3  according to the following rotational positions of the upper body  5 . The force F 1  is generated when the upper body  5  is closed, the force F 2  is generated when the upper body  5  is opened, and the force F 3  is generated when the upper body  5  is at the midpoint position. The force f, the resultant of forces fx and fy, varies into force f 1 , f 2 , or f 3  at the respective rotational positions of the upper body  5 .  
         [0040]    The forces f 1 , f 2 , f 3  are associated with the first range  37   a , the second range  37   b , and the third range  37   c , respectively. As described above, in the first range  37   a , the resultant moment acting on the upper body  5  acts in the direction to close the upper body  5 . The first range  37   a  is determined in such a manner to set the force F 1  greater than the force f 1 . Thereby, the moment is generated in the direction to close the upper body  5 .  
         [0041]    In the second range  37   b , the moment acts in the direction to open the upper body  5 . Therefore, the second range  37   b  is determined in such a manner to set forces f 2 , f 3  greater than forces F 2 , F 3 . Thereby, the moment is produced in the direction to open the upper body  5 .  
         [0042]    When the upper body  5  is pivoted from the close position toward the open position so that the cam follower  33  reaches the second range  37   b  in the cam groove  37 , the moment to pivot the upper body  5  toward the open position is generated. The upper body  5  is pivoted toward the open position, the cam follower  33  abuts against an end of the cam groove  37 , and the upper body  5  comes to rest. Thus, the upper body  5  can be kept at the open position without the need to be supported by a user, facilitating jobs performed in a space between the upper body  5  and the lower body  3 , such as repairing and adjustment of the printer  1  and replacement of the cartridge  61 .  
         [0043]    When the upper body  5  is pivoted toward the close position so that the cam follower  33  reaches the first range  37   a  in the cam groove  37 , the moment to pivot the upper body  5  toward the close position is exerted. Thus, the upper body  5  pivots toward the close position under its own weight. Therefore, there is no need to apply an excessive strength so as to close the upper body  5 .  
         [0044]    Another cam groove  137  is shown in FIG. 6. The cam groove  137  has a first range  137   a , a second range  137   b , and a third range  137   c . The first range  137   a  is provided to the front of the printer  1 . In the first range  137   a , the resultant moment acting on the upper body  5  is exerted in a direction to close the upper body  5 . The second range  137   b  is provided to the rear of the printer  1 . In the second range  137   b , a balance between the force F and the force f is achieved. The third range  137   c  is provided in a position continuously connecting the first range  137   a  and the second range  137   b . In the third range  137   c  , the moment acting on the upper body  5  is changed from the direction to close the upper body  5  to the direction to keep the balance.  
         [0045]    As long as the cam follower  33  is within the second range  137   b  in the cam groove  137 , the upper body  5  is held still at a specified position.  
         [0046]    Thereby, the upper body  5  can be prevented from pivoting toward the open position spontaneously. It is convenient when the upper body  5  can not be completely pivoted to the open position, for example, because the printer  1  is used where space is limited.  
         [0047]    Further, another cam groove  237  is shown in FIG. 7. The cam groove  237  includes a first range  237   a , a second range  237   b , a third range  237   c , a fourth range  237   d , a fifth range  237   e , a sixth range  237   f , and a seventh range  237   g . The first range  237   a  is provided to the front of the printer  1 , where the moment acting on the upper body  5  is exerted in the direction to close the upper body  5 . In the second range  237   b , the moment acting on the upper body  5  acts in the direction to open the upper body  5 . In the third range  237   c , the moment acting on the upper body  5  acts in the direction to close the upper body  5 . In the fourth range  237   d , the moment acting on the upper body  5  acts in the direction to open the upper body  5 . The fifth range  237   e  is provided in a position continuously connecting the first range  237   a  and the second range  237   b , where the direction of the moment acting on the upper body  5  is changed. The sixth range  237   f  is provided in a position continuously connecting the second range  237   b  and the third range  237   c , where the moment acting on the upper body  5  is not produced. The seventh range  237   g  is provided in a position continuously connecting the third range  237   c  and the fourth range  237   d , where the direction of the moment acting on the upper body  5  is changed.  
         [0048]    When the upper body  5  is pivoted from the close position toward the open position so that the cam follower  33  reaches the second range  237   b  in the cam groove  237 , the moment to pivot the upper body  5  toward the open position is exerted. When the upper body  5  is further pivoted toward the open position, the cam follower  33  reaches the sixth range  237   f , and the upper body  5  comes to rest. When the upper body  5  is further pivoted toward the open position against the moment acting on the upper body  5  while the cam follower  33  is in the third range  237   c , the moment to pivot the upper body  5  toward the open position is exerted in the fourth range  237   d . Thereby, the cam follower  33  abuts against an end portion of the cam groove  237  and the upper body  5  comes to rest.  
         [0049]    When the upper body  5  is pivoted toward the close position so that the cam follower  33  reaches the third range  237   c  in the cam groove  237 , the moment to pivot the upper body  5  toward the close position is exerted. Thereby the upper body  5  pivots by its own weight, the cam follower  33  is moved in the sixth range  237   f , and the upper body  5  comes to rest.  
         [0050]    Because the upper body  5  is held still while the cam follower  33  is in the sixth range  237   f , the upper body  5  can be prevented from pivoting toward the open position spontaneously. It is convenient when the upper body  5  can not be completely pivoted to the open position, for example, because the printer  1  is used where space is limited.  
         [0051]    If the cam follower  33  is moved to the second range  237   b  from this state, the moment acts on the upper body  5  toward the open position, so that the force f normally acts in the direction to return the cam follower  33  to the sixth range  237   f . When the upper body  5  is further pivoted toward the close position so that the cam follower  33  moves over the fifth range  237   e , the upper body  5  pivots to the close position by its own weight.  
         [0052]    As shown in FIG. 4, the image scanner mechanism  1   b  is of flat bed type and is accommodated in the upper body  5 . The image scanner mechanism  1   b  includes the line type image sensor  8 , which is movably mounted on a rail  10 . The line type image sensor  8  moves along the platen glass  9  and reads image from a document placed on the platen glass  9 .  
         [0053]    The laser printing mechanism la has a scanner unit  51 , a photosensitive drum  53 , a developing roller  55 , a toner cartridge  62 , a toner supply roller  63 , the sheet roller  56 , a transfer roller  57  and a fixing unit  59 . The scanner unit  51  emits a laser beam in accordance with the image data read by the image scanner mechanism  1   b  or input from outside to form an electrostatic latent image on the photosensitive drum  53 . A toner accommodated in the toner cartridge  62  is supplied to the developing roller  55  via the toner supply roller  63 . When the developing roller  55  supplies the toner to the surface of the photosensitive drum  53 , the electrostatic latent image on the photosensitive drum  53  is developed as a toner image or a visible image. At this time, the toner is adhered on a charged part of the photosensitive drum  53  where the latent image is formed. The toner is not adhered on a part that does not become charged. The transfer roller  57  presses a recording sheet, which is supplied from the sheet tray  11  and fed by the sheet roller  56 , against the photosensitive drum  53 . The voltage is applied to the transfer roller  57  to attract the toner toward the recording sheet, and the toner image on the photosensitive drum  53  is transferred onto the recording sheet. The fixing unit  59  applies heat to the toner image transferred onto the recording sheet to fix the image onto the recording sheet.  
         [0054]    The sheet roller  56 , the photosensitive drum  53 , the transfer roller  57 , and rollers in the fixing unit  59  constitute a conveying mechanism that feeds the recording sheets from the sheet tray  11  to the discharge portion  13 . A paper feed path by the conveying mechanism is straight (shown by a thick double dotted line in FIG. 4B) such that each of the recording sheets is always fed with a recorded surface thereof facedown. Therefore, the orientation of the recorded surface of the sheet remains unchanged in the paper feed path, which prevents the recording sheets from curling.  
         [0055]    The scanner unit  51  and the photosensitive drum  53  are disposed under the paper feed path. As the image is formed on the recorded surface of the recording sheet facedown, the sheet is discharged from the printer  1  without causing the recording sheet to make a U-turn. The recording sheets are discharged facedown in the order of recording, and the order of pages is not reversed.  
         [0056]    The photosensitive drum  53 , the developing roller  55 , the transfer roller  57 , the toner cartridge  62 , and the toner supply roller  63  are mounted in a cartridge  61  as shown in FIG. 11. The cartridge  61  is removable from the lower body  3  when the upper body  5  is pivoted to the open position. The lower body  3  includes a recessed portion  3   d  to fit the bottom surface of the cartridge  61 . When the cartridge  61  is inserted into the lower body  3 , the cartridge  61  fits in the recessed portion  3   d  in position by its own weight.  
         [0057]    The bridge  27  moves to cover the fixing unit  59  when the upper body  5  is pivoted to the open position. This prevents a user from touching the heated fixing unit  59  by mistake during replacement of the cartridge  61 .  
         [0058]    [0058]FIG. 13 shows another conveying mechanism. In this example, a sheet tray  70  is disposed on the bottom of the lower body  3 , and recording sheets are fed to the laser printing mechanism  1   a  via sheet rollers  71 ,  72 . In a paper feeding path by the conveying mechanism also, each of the recording sheets is always fed with a recorded surface thereof facedown.  
         [0059]    According to the printer  1  structured as described above, when the upper body  5  including the image scanner mechanism  1   b  is pivoted toward the open position, the upper body  5  and the lower body  3  are unlocked to provide a wide space so that the cartridge  61  can be detached from the printer  1  via the wide space. Thus, the convenience in replacement of the cartridge  61  can be increased. In particular, the printer  1  offers an advantage in that, when the upper body is pivoted to the open position, the bridge  27  (the movable member  23 ) moves downward. Compared with a structure where the upper body  5  only is pivoted to the open position, a space between the bridge  27  and the upper body  5  is further enlarged, thereby improving the convenience of the operation implemented with the upper body  5  in the open position.  
         [0060]    The height of the printer  1  becomes small with the upper body  5  in the close position. Because the printer  1  does not allocate a space for replacement of the cartridge  61 , the printer  1  does not increase in size.  
         [0061]    As the scanner unit  51  is fixed to the lower body  3 , an accuracy of an installation position of the scanner unit  51  can be assured although the upper body  5  is movable.  
         [0062]    As the two link members  25  are disposed apart from each other, they support the upper body  5  at many points, comparing with a structure where only one link member is disposed. Thus, the stability increases when the upper body  5  is open. In addition, as the bridge  27  is connected between the link members  25 , the rotational angle of the link members  25  is always kept in alignment, and the upper body  5  resists torsional stress. As the link members  25  synchronically move, the movement of the upper body  5  can be smooth comparing with a structure where link members operate separately.  
         [0063]    In the printer  1 , the operating lever  45 , which is used for disengagement between the engaging portion  43  and the engaged portion  41 , is provided with the upper body  5 . When the upper body  5  is manually held and pivoted to the open position by a user, the operating lever  45  enables the disengagement and opening of the upper body  5  to be done at the same place and in one step.  
         [0064]    The image scanner mechanism  1   b  is of a flat bed type and includes the image sensor that moves along a document to read an image therefrom. As the image scanner mechanism  1   b  is mounted in the upper body  5  that is less prone to being deformed, reading accuracy of the flat bed-type image scanner can be properly kept.  
         [0065]    The spring  39  is disposed so as to expand as the upper body  5  is pivoted to the close position in the printer  1 . However, as long as the cam follower  33  can be urged toward the rear of the printer  1 , the spring  39  may be disposed to be compressed as the upper body  5  is pivoted to the close position, according to the positional relationship between the link member  25  and the spring  39 .  
         [0066]    According to the printer  1 , when the operating lever  45  is horizontally slid, the engagement between the engaged portion  41  and the engaging portion  43  is released. Instead, as shown in FIGS. 12A and 12B, an engaging portion  73  and an operating lever  75  that pivot around a shaft  71 , and a spring  77  may be provided. With this structure, the engagement between the engaged portion  41  and the engaging portion  73  can be released by pivoting the operating lever  75  against a load of the spring  77 .  
         [0067]    In the printer  1 , the bridge  27  serves as a cover of the fixing unit  59  that is to heat up. If the fixing unit  59  becomes unnecessary because an ink jet type image scanner portion is adopted, for example, the bridge  27  does not need to function as the cover.  
         [0068]    In the printer  1 , the bridge  27  (the movable member  23 ) is moved at a position to cover the fixing unit  59 . With the adoption of a cover dedicated to the fixing unit, the movable member  23  does not need moving to the position to cover the fixing unit.  
         [0069]    If the structure of moving the upper body  5  to the open position suffices, the printer  1  may not include the above-described movable member.  
         [0070]    The printer  1  is provided with the scanner unit  51  that emits a laser beam, however, may be structured where a light emitting head including light emitting diodes in line is used to emit the light onto a photo conductor.  
         [0071]    The cam groove  37 ,  137 ,  237  is formed in the lower body  3 , however, a printer  1  may be provided with a guide member with a cam groove.  
         [0072]    While the invention has been described with reference to specific embodiments, the description of the embodiments are illustrative only and are not to be construed as limiting the scope of the invention. Various other modifications and changes may occur to those skilled in the art without departing from the spirit and scope of the invention.