Abstract:
An image forming apparatus includes a support column having one end fixed to an apparatus body and the other end that turnably supports an operation unit, an opening and closing member that moves between a closed position to hide an inside of the apparatus body and an open position to expose the inside, and a lock unit that holds the operation unit at a first holding position to hold the operation unit within a moving area of the opening and closing member and a second holding position to hold the operation unit outside the moving area of the opening and closing member. The lock unit releases the operation unit in cooperation with opening of the opening and closing member in a state in which the operation unit is held at the first holding position, and moves the operation unit to the second holding position while keeping the operation unit released.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is based on and claims priority under 35 USC  119  from Japanese Patent Application No. 2013-112522 filed May 29, 2013. 
       BACKGROUND 
     Technical Field 
       [0002]    The present invention relates to an image forming apparatus. 
       SUMMARY 
       [0003]    According to an aspect of the invention, there is provided an image forming apparatus including a support column having one end fixed to an apparatus body and the other end that turnably supports an operation unit, an opening and closing member that moves between a closed position to hide an inside of the apparatus body and an open position to expose the inside, and a lock unit that holds the operation unit at a first holding position to hold the operation unit within a moving area of the opening and closing member and a second holding position to hold the operation unit outside the moving area of the opening and closing member. The lock unit releases the operation unit in cooperation with an opening operation of the opening and closing member in a state in which the operation unit is held at the first holding position, and moves the operation unit to the second holding position while keeping the operation unit released. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    An exemplary embodiment of the present invention will be described in detail based on the following figures, wherein: 
           [0005]      FIG. 1  is an external front view of an image forming apparatus; 
           [0006]      FIG. 2  is a schematic cross-sectional view illustrating an internal configuration of the image forming apparatus; 
           [0007]      FIG. 3  is a rear (back) perspective view of an operation unit; 
           [0008]      FIG. 4  is a rear (back) plan view of the operation unit; 
           [0009]      FIG. 5A  is a perspective view of a ratchet member that constitutes the operation unit, and  FIG. 5B  is a perspective view of a release lever that constitutes the operation unit; 
           [0010]      FIG. 6  is an enlarged principal view illustrating operation of a toggle mechanism; 
           [0011]      FIGS. 7A to 7C  schematically illustrate a movement of the operation unit made by opening a front covering; 
           [0012]      FIG. 8  schematically illustrates a movement of the operation unit made by manually operating a movable arm; and 
           [0013]      FIG. 9  schematically illustrates a tilt movement of the operation unit made by manually operating the movable arm. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    An exemplary embodiment of the present invention will be described in detail below with reference to the drawings. The present invention is not limited to the exemplary embodiment. 
         [0015]    In the following description with reference to the drawings, it should be noted that the drawings are schematic and the proportion in dimensions of each member is different from actual one. Illustration of members other than necessary members for explanation will be properly omitted for easy understanding. 
       1. Configuration of Image Forming Apparatus 
       [0016]      FIG. 1  is an external front view of an image forming apparatus  1  according to an exemplary embodiment, and  FIG. 2  is a schematic cross-sectional view illustrating an internal configuration of the image forming apparatus  1 . 
         [0017]    The overall configuration and operation of the image forming apparatus  1  will be described below with reference to the drawings. 
       1.1 System Configuration of Image Forming Apparatus 
       [0018]    The image forming apparatus  1  includes a control device  10 , a paper feeding device  20 , a photoconductor unit  30 , a developing device  40 , an exposure device  50 , a transfer device  60 , a fixing device  70 , an operation unit  80 , and an image reader  90 . 
         [0019]    On a front side of the image forming apparatus  1 , a front covering  1   a  is turnably supported to open the inside of the image forming apparatus  1  frontward (in an X-direction), for example, when consumables are replaced. 
         [0020]    On a rear side of the image forming apparatus  1 , a rear covering  1   b  is turnably supported to open the inside of the image forming apparatus  1  in case of a paper jam or inside inspection. 
         [0021]    On an upper side (Z-direction) of the image forming apparatus  1 , an output tray  1   c  is provided to receive output sheets on which images are recorded. 
         [0022]    The control device  10  includes an image-forming-apparatus control unit  11  that controls the operation of the image forming apparatus  1 , a controller  12  that prepares image data according to a print request, an exposure control unit  13  that controls the lighting of a light source in the exposure device  50 , and a power supply device  14 . The power supply device  14  applies voltage to a charging roller  32 , a developing roller  42 , a transfer roller  61 , etc. described below, and supplies electric power to the exposure device  50 . 
         [0023]    The controller  12  converts image data input from the image reader  90  and print information input from an external information transmission device (for example, a personal computer) into image information for forming a latent image, and outputs driving signals to the exposure control unit  13  at a preset timing. 
         [0024]    The operation unit  80  is used to input various settings and instructions and to display information. That is, the operation unit  80  corresponds to a so-called user interface. More specifically, the operation unit  80  is formed by a combination of a liquid crystal display panel, various control buttons, a touch panel, etc. 
       1.2 Configuration and Operation of Image Forming Section 
       [0025]    The paper feeding device  20  is provided at the bottom of the image forming apparatus  1 . The paper feeding device  20  includes a paper cassette  21  that stores sheets serving as recording media. A lot of sheets are stacked on an upper surface of the paper cassette  21 . The sheets stacked on the paper cassette  21  are positioned in a width direction by a regulation plate (not illustrated), are drawn out one by one from an upper side by a sheet drawing member  22 , and are then transported to a nip between a pair of registration rollers  23 . 
         [0026]    The photoconductor unit  30  is provided above the paper feeding device  20 , and includes a photoconductor drum  31  that is rotationally driven. A charging roller  32 , a developing device  40 , a transfer roller  61 , and a cleaning blade  34  are arranged in a rotating direction of the photoconductor drum  31 . A cleaning roller  33  for cleaning a surface of the charging roller  32  is provided in opposed contact with the charging roller  32 . 
         [0027]    The developing device  40  includes a developing housing  41  that stores developer. In the developing housing  41 , a developing roller  42  opposed to the photoconductor drum  31 , and a paddle wheel  43  provided on an obliquely lower back side of the developing roller  42  to agitate and transport the developer toward the developing roller  42 . Further, a pair of augers  44  and  45  for agitation and transport are provided on a back side of the paddle wheel  43 . A layer regulation roller  46  for regulating the layer thickness of developer is provided close to the developing roller  42 . 
         [0028]    The exposure device  50  includes a laser beam emitting unit  51  used as a light source, and a rotating polygonal mirror  52  that deflects and reflects a laser beam LB from the laser beam emitting unit  51 . The exposure device  50  scans the surface of the photoconductor drum  31  with the laser beam LB modulated according to data on an image to be formed. 
         [0029]    The surface of the rotating photoconductor drum  31  is charged by the charging roller  32 , and an electric latent image is formed thereon by the laser beam LB emitted from the exposure device  50 . The electrostatic latent image formed on the photoconductor drum  31  is developed as a toner image by the developing roller  42 . 
         [0030]    The transfer device  60  includes a transfer roller  61  that forms a nip with the photoconductor drum  31 , and a rear covering  1   b  that supports the transfer roller  61  so that the transfer roller  61  can move into contact with and away from the photoconductor drum  31 . A transfer voltage is applied to the transfer roller  61  from the power supply device  14  controlled by the image-forming-apparatus control unit  11  so that the toner image on the photoconductor drum  31  is transferred onto a sheet passing between the photoconductor drum  31  and the transfer roller  61 . 
         [0031]    Residual toner on the surface of the photoconductor drum  31  is removed by the cleaning blade  34 , and is collected into a housing that supports the photoconductor drum  31 . After that, the surface of the photoconductor drum  31  is charged gain by the charging roller  32 . Residues, which are not removed by the cleaning blade  34 , but are attached to the charging roller  32 , are captured by the surface of the cleaning roller  33  rotating in contact with the charging roller  32 , and are then accumulated. 
         [0032]    The fixing device  70  includes a pair of fixing rollers  71  and  72 , and a fixing area is formed by a press contact area between the fixing rollers  71  and  72 . 
         [0033]    After the toner is transferred on a sheet by the transfer roller  61 , the sheet is transported to the fixing device  70  via a transport guide  62  in a state in which the toner image is unfixed. The toner image is fixed on the sheet transported to the fixing device  70  with pressure and heat by the fixing rollers  71  and  72 . The sheet on which the toner image is formed is guided by transport guides  73   a  and  73   b , and is output from a pair of output rollers  74  onto the output tray  1   c  provided on the upper surface of the image forming apparatus  1 . 
       2. Configuration of Operation Unit 
       [0034]      FIG. 3  is a rear (back) perspective view of the operation unit  80 ,  FIG. 4  is a rear (back) plan view of the operation unit  80 ,  FIG. 5A  is a perspective view of a ratchet member  83  that constitutes the operation unit  80 , and  FIG. 5B  is a perspective view of a release lever  86  that constitutes the operation unit  80 . 
         [0035]    The structure of the operation unit  80  will be described below with reference to the drawings. 
         [0036]    The operation unit  80  is used to input various settings and instructions and to display information. The operation unit  80  includes a user interface  81  in which a liquid crystal display panel P and various control buttons B are combined, a support column  82  that turnably supports the user interface  81 , a flip-up spring (not illustrated) serving as a biasing member that turns upward and flips up the user interface  81  from the support column  82 , a ratchet mechanism that turnably holds the user interface  81 , a release mechanism that releases engagement of the ratchet mechanism, and a holding mechanism that holds engagement of the ratchet mechanism. 
       2.1 Ratchet Mechanism 
       [0037]    The ratchet mechanism includes a ratchet member  83  serving as a fixed-side holding portion fixed to the support column  82 , a movable-side movable arm  84  opposed to the ratchet member  83  to turn together with the user interface  81 , and a known biasing member (not illustrated) that biases the movable arm  84  in a direction to press the movable arm  84 . 
         [0038]    As illustrated in  FIG. 5A , a fixed-side first ratchet tooth  83   b  shaped like a sawtooth is provided continuously and integrally with one end of a peripheral surface of a cylindrical body  83   a  of the ratchet member  83 , and a cam portion  83   c  is provided integrally with the other end of the peripheral surface of the cylindrical body  83   a.    
         [0039]    Correspondingly, as illustrated in  FIGS. 3 and 4 , the movable arm  84  is formed by an integral body including an entirely columnar turn shaft  84   a , a second ratchet tooth  84   b  serving as a pawl standing from at one end of a peripheral surface of the turn shaft  84   a  in a direction intersecting the turn shaft  84   a , and a fan-shaped wall portion  84   c  standing from the other end of the peripheral surface of the turn shaft  84   a  in a direction intersecting the turn shaft  84   a . Further, a projection pin  84   d  having a round tip projects from the fan-shaped wall portion  84   c  in a turn axis direction. 
         [0040]    At the center of the turn shaft  84   a  of the movable arm  84 , a handle  84   e  shaped like a flat plate stands integrally from the peripheral surface of the turn shaft  84   a  in a direction intersecting the turn shaft  84   a.    
         [0041]    A torsion spring serving as an example of a biasing member is inserted between the user interface  81  and the handle  84   e  centered on the turn shaft  84   a  of the movable arm  84  to press the second ratchet tooth  84   b  against the first ratchet tooth  83   b . This permits an upward turn of the user interface  81  and restricts a downward turn of the user interface  81 . 
       2.2 Release Mechanism 
       [0042]    The release mechanism includes the movable arm  84  and a release lever  85  that is turned by contact with the front covering  1   a.    
         [0043]    As illustrated in  FIG. 5B , the release lever  85  has a turn shaft  85   a  at its center. A fan-shaped wall portion  85   b  is provided integrally with one end of the release lever  85 , and a lever portion  85   c  that is turned by contact with the front covering  1   a  is provided integrally with the other end of the release lever  85 . 
         [0044]    A cam portion  85   d  projects integrally from one surface of the fan-shaped wall portion  85   b , and the cam portion  85   d  has a tapered portion  85   e.    
         [0045]    The projection pin  84   d  of the movable arm  84  and the fan-shaped wall portion  85   b  of the release lever  85  thus structured are held in turnable contact with each other by the action of a below-described toggle mechanism. 
         [0046]    The release lever  85  is constantly biased by a known spring member (not illustrated) in a direction opposite to a direction in which it is moved when the front covering  1   a  is opened. 
       2.3 Holding Mechanism 
       [0047]    The holding mechanism includes the ratchet member  83  and the movable arm  84 , and holds the user interface  81  at a second holding position outside a moving area of the front covering  1   a.    
         [0048]    As illustrated in  FIG. 5A , the cam portion  83   c  is provided integrally with the peripheral surface of the cylindrical body  83   a  of the ratchet member  83 , and the cam portion  83   c  has a tapered portion  83   d.    
         [0049]    In the holding mechanism having the above-described structure, when the user interface  81  moves to the second holding position, a side surface of the second ratchet tooth  84   b  of the movable arm  84  comes into contact with the tapered portion  83   d  of the cam portion  83   c , and moves the second ratchet tooth  84   b  closer to approach the first ratchet tooth  83   b , and the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are held in an engaged state. 
       2.4 Toggle Mechanism 
       [0050]      FIG. 6  is an enlarged principal view illustrating the operation of the toggle mechanism. 
         [0051]    The toggle mechanism includes a pushpin  84   g  projecting from an middle point of the peripheral surface of the turn shaft  84   a  of the movable arm  84  to be moved forward and backward by a push spring  84   f , and a movable piece  86  held on the user interface  81  to swing on its center point while being in contact with the pushpin  84   g . The toggle mechanism switches between states in which biasing force acts and does not act in the turn axis direction of the movable arm  84 . 
         [0052]    The movable arm  84  is held in a state in which biasing force acts so that the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are held in an engaged state with each other. 
       3. Operation of Operation Unit 
       [0053]      FIGS. 7A to 7C  schematically illustrate a movement of the operation unit  80  made by opening the front covering  1   a ,  FIG. 8  schematically illustrates a movement of the operation unit  80  made by manually operating the movable arm  84 , and  FIG. 9  schematically illustrates a tilt movement of the operation unit  80  made by manually operating the movable arm  84 . The movement of the operation unit  80  will be described below with reference to the drawings. 
       3.1. Movement of Operation Unit Made by Opening Front Covering 
       [0054]    When the front covering  1   a  is turned open to open the front side (X-direction) of the image forming apparatus  1 , a projection (not illustrated) provided at one end of the front covering  1   a  comes into contact with the lever portion  85   c  of the release lever  85 , and the lever portion  85   c  turns (see the arrow in  FIG. 7A ). 
         [0055]    As the lever portion  85   c  turns, the tapered portion  85   e  of the cam portion  85   d  of the cam portion  85   d  projecting from one surface of the fan-shaped wall portion  85   b  comes into contact with the projection pin  84   d  projecting from the fan-shaped wall portion  84   c  of the movable arm  84 . 
         [0056]    As the lever portion  85   c  further turns, the movable arm  84  moves in the turn axis direction until the projection pin  84   d  of the movable arm  84  comes into contact with an upper surface of the cam portion  85   d , so that the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are disengaged from each other (see the arrow in  FIG. 7B ). 
         [0057]    When the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are disengaged, the user interface  81  turnably supported by the support column  82  is turned by biasing force of the flip-up spring, and moves from a standing position relative to the image forming apparatus  1  (a first holding position) to the outside of the moving area of the front covering  1   a  and is brought into a substantially horizontal state (a second holding position). 
         [0058]    At the same time as the user interface  81  is brought into the substantially horizontal state at the second holding position, the side surface of the second ratchet tooth  84   b  of the movable arm  84  comes into contact with the tapered portion  83   d  of the cam portion  83   c  provided on the ratchet member  83 , the second ratchet tooth  84   b  moves closer to the first ratchet tooth  83   b , and the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are engaged and held at the second holding position (see the arrows in  FIG. 7C ). 
         [0059]    At the second holding position, the toggle mechanism restricts the movement of the movable arm  84  in the turn axis direction so that the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are held in the engaged state. 
       3.2 Movement of Operation Unit Made by Manually Operating Movable Arm 
       [0060]    When the user pulls the handle  84   e  shaped like a flat plate, which is provided integrally with the center of the turn shaft  84   a  of the movable arm  84 , toward the user interface  81 , the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are disengaged from each other (see  FIG. 8 ). 
         [0061]    When the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are disengaged, the user interface  81  is turned by the biasing force of the flip-up spring and is brought from the standing state (first holding position) relative to the image forming apparatus  1  into a substantially horizontal state (second holding position) outside the moving area of the front covering  1   a.    
         [0062]    Subsequent operations of the holding mechanism are similar to those performed when the operation unit  80  is moved by opening the front covering  1   a.    
         [0063]    The holding mechanism can also be used as a tilt mechanism. In this case, the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are disengaged from each other by pulling the handle  84   e  of the movable arm  84  toward the user interface  81  from the state in which the user interface  81  is held at the second holding position, and the first ratchet tooth  83   b  and the second ratchet tooth  84   b  are held at an engaged state again at a predetermined turn position (see  FIG. 9 ). 
         [0064]    The foregoing description of the exemplary embodiment 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 embodiment was 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.