Abstract:
An opening and closing device includes a cover gear, a driving source, a cover, a biasing element, and a control portion. The cover gear is rotatably supported in both forward and backward directions. The driving source selectively provides rotation to the cover gear in both the forward and backward directions. The cover is rotatably supported to allow motion in both the forward and backward directions between first and second positions. The biasing element transmits the rotation of the cover gear to the cover while biasing the cover in a predetermined direction from the first position to the second position. The control portion stops the rotation of the driving source, in a case in which the driving source is rotated to move the cover in the predetermined direction, when the cover gear rotates in the predetermined direction by a predetermined angle after the cover has reached the second position.

Description:
CROSS REFERENCE 
       [0001]    This Nonprovisional application claims priority under 35 U.S.C. §119(a) on Patent Application No. 2011-227689 filed in Japan on Oct. 17, 2011, the entire contents of which are hereby incorporated by reference. 
       BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to an opening and closing device that automatically opens and closes an opening and closing cover by rotation of a motor, and also relates to an electronic apparatus and an image forming apparatus that are equipped with such an opening and closing device. 
         [0003]    Some electronic apparatuses such as an image forming apparatus read data from a recording medium, such as a memory card and an optical disc, which is inserted into an insertion opening by a user, and perform an image formation process, such as photo printing, using the read data. When the recording medium is pulled out from the insertion opening while data is being read, the data in the recording medium may be damaged. In attempt to overcome such a problem, an opening and closing device that opens and closes an insertion opening with a cover is used. 
         [0004]    For example, Japanese Patent Laid-Open Publication No. 2005-74981 discloses an opening and closing device that swingably supports a cover, by a swinging shaft of a cover body, between a closed state in which the cover covers a memory slot and an open state in which a memory can be attached to and detached from the memory slot. When the cover is in a position close to the closed state, an elastic force of a twisted coil spring acts on the cover in a closing direction, and when the cover is in a position close to the open state, the elastic force of the twisted coil spring acts on the cover in an opening direction. The load of an oil damper acts on the swing of the cover. This configuration is believed to improve operability and use experience, by providing assistance in the manual operations of the cover by the user through the elastic force of the twisted coil spring, and by controlling the swing speed to an appropriate speed, and thus preventing the cover from becoming partially open. 
         [0005]    Furthermore, in order to eliminate the need for the user to operate the cover, there is an opening and closing device provided with a motor that rotates in both a forward direction and a backward direction and a transmission mechanism in which the forward rotation and the backward rotation of the motor are selectively transmitted to the cover. 
         [0006]    However, when the rotation stop position of the motor is changed due to errors such as a mounting error, the load that acts on the motor and the transmission mechanism becomes excessively large. In addition, the load of the motor also becomes large in a case in which the motor is excessively rotated in order to securely close the cover. These may cause a possibility of generation of abnormal noise from the motor and breakage of the motor and the transmission mechanism. Moreover, in a case in which a finger of the user is caught while the cover is being closed, the operation of the cover cannot be stopped. 
         [0007]    In view of the foregoing, an object of the present invention is to provide an opening and closing device that can automatically open and close a cover without making a load of a motor and a transmission mechanism excessively large, and to provide an electronic apparatus and an image forming apparatus that are equipped with such an opening and closing device. 
       SUMMARY OF THE INVENTION 
       [0008]    An opening and closing device of the present invention is provided with a cover gear, a driving source, a cover, a biasing element, and a control portion. The cover gear is rotatably supported in both a forward direction and a backward direction. The driving source selectively provides rotation to the cover gear in both the forward direction and the backward direction. The cover is rotatably supported to allow motion in both the forward direction and the backward direction between a first position and a second position. The biasing element transmits the rotation of the cover gear to the cover while biasing the cover in a predetermined direction from the first position to the second position. The control portion stops the rotation of the driving source, in a case in which the driving source is rotated so as to move the cover in the predetermined direction, when the cover gear rotates in the predetermined direction only by a predetermined angle after the cover has reached the second position. 
         [0009]    The foregoing and other features and attendant advantages of the present invention will become more apparent from the reading of the following detailed description of the invention in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0010]      FIG. 1A  is a side view of an image forming apparatus according to an embodiment of the present invention and  FIG. 1B  is a front view of the image forming apparatus according to the embodiment of the present invention; 
           [0011]      FIG. 2  is an external view of a data acquisition portion included in the image forming apparatus; 
           [0012]      FIG. 3A  is a perspective view from a cover side, showing a mechanism of an opening and closing device included in the data acquisition portion and  FIG. 3B  is a perspective view from a cover gear side, showing the mechanism of the opening and closing device included in the data acquisition portion; 
           [0013]      FIG. 4A  is a side view in a state in which the cover is open,  FIG. 4B  is a side view in a state in which the cover is closed, and  FIG. 4C  is a side view in a state in which the cover gear is rotated only by a predetermined angle from the state in which the cover is closed; 
           [0014]      FIG. 5  is a block diagram showing a part of a functional portion of the image forming apparatus; 
           [0015]      FIG. 6  is a flow chart showing process steps at a time of an image forming process in the image forming apparatus; 
           [0016]      FIG. 7  is a flow chart showing a closing process of the cover in the image forming apparatus; 
           [0017]      FIG. 8  is a flow chart showing an opening process of the cover in the image forming apparatus; and 
           [0018]      FIGS. 9A and 9B  are perspective views showing other examples of the mechanism of the opening and closing device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0019]    As shown in  FIG. 1 , an image forming apparatus  100  is provided with a monitor  110 , a main body portion  120 , and a data acquisition portion  130 , and prints an image on a sheet for a photographic image as a recording element. 
         [0020]    The monitor  110  is disposed on the upper part of the image forming apparatus  100 . The monitor  110  has a touch panel and accepts various settings such as selection of data to be printed and a print start command. 
         [0021]    The main body portion  120  is provided with a coin receiving port  121 , a bill receiving port  122 , a money ejection port  123 , and an output port  124 , and is disposed on the lower part of the image forming apparatus  100 . The coin receiving port  121  receives a coin for payment, and the bill receiving port  122  receives a bill for payment. The money ejection port  123  ejects a change after settlement of the payment. The output port  124  outputs a photograph after printing. 
         [0022]    As shown in  FIG. 2 , the data acquisition portion  130  is provided with a memory slot  131 , a disc drive  132 , and an opening and closing device  30  (see  FIG. 3 ) of a cover  20 , and is disposed between the monitor  110  and the main body portion  120 . 
         [0023]    The memory slot  131  has an insertion opening  131 A at the front, and accepts insertion of a memory card as a recording medium from the insertion opening  131 A. The disc drive  132  has an insertion opening  132 A at the front, and accepts insertion of an optical disc such as a compact disc and a DVD as a recording medium from the insertion opening  132 A. 
         [0024]    The cover  20  moves back and forth between a closed state and an open state in a circular arc following a shape of a concave curve that faces the insertion openings  131 A and  132 A. The cover  20  covers the insertion openings  131 A and  132 A in the closed state. 
         [0025]    As shown in  FIG. 3 , the opening and closing device  30  is provided with the cover  20 , a cover gear  31 , a gear  32 , a twisted coil spring (which is equivalent to a biasing element of the present invention)  33 , a motor (which is equivalent to a driving source of the present invention)  34 , and a pair of sensors (which are equivalent to a sensing portion of the present invention)  35  and  36 . To begin with, a description will be made of each element that constitutes the opening and closing device  30 . 
         [0026]    The cover  20  is, as viewed from the side, in a shape of a circular arc of which an angle is obtuse. The cover  20 , as viewed from the front, has a pair of support elements  21  and  22  that support the cover  20  and that are formed integrally on both ends of the cover  20 . Each of the support elements  21  and  22 , as viewed from the side, is formed on an end of the circular arc of the cover  20 , and protrudes toward the concave side of the circular arc. The pair of support elements  21  and  22  has penetrating ports  21 A and  22 A that are formed on an open end side of the support elements  21  and  22 , respectively. 
         [0027]    The cover gear  31  is in the shape of a fan as viewed from the side, has a circular arc shaped gear  311  with a convex curved tip, and is formed on the leading edge side in which the two sides that form a circular arc  310  in between intersect. The circular arc shaped gear  311  forms an obtuse angle and has a penetrating port  312  that is formed in the center of the gear  311 . The circular arc shaped gear  311  is linked to a gear  32  and is supplied with rotation of the motor  34  through the gear  32 . The motor  34  is controlled by a control portion  105  (see  FIG. 5 ). 
         [0028]    The cover gear  31  includes a pair of restricting ribs  313  and  314  that restrict rotation of the support element  21 . The restricting rib  313  is in the approximate shape of a letter L, and is provided with: a body portion  313 A formed along one of the two sides holding the circular arc  310  in between; and a protruding portion  313 B which protrudes on an extension of the circular arc  310  and toward the outside of the cover gear  31 . The restricting rib  314  is in the approximate shape of a letter L, and is provided with: a body portion  314 A in which a direction from the circular arc shaped gear  311  to the circular arc  310  is defined as a longitudinal direction; and a protruding portion  314 B which is formed along the circular arc  310  and protrudes toward the outside of the cover gear  31 . The body portion  313 A and the body portion  314 A are disposed so that one end of the support element  21  may contact the body portion  314 A when the support element  21  is rotated only by a predetermined angle from a state in which the other end of the support element  21  contacts the body portion  313 A. 
         [0029]    The twisted coil spring  33  is provided with a coil portion  331  and arms  332  and  333 , and receives twisting moment around the central axis of the coil portion  331 . The arm  332  is formed longer than the arm  333 . 
         [0030]    The pair of sensors  35  and  36  is an optical sensor, and is provided with concave portions  351  and  361 , respectively. The sensor  35  senses that the protruding portion  313 B of the restricting rib  313  has reached the concave portion  351  and outputs the sensed result to the control portion  105  while the sensor  36  senses that the protruding portion  314 B of the restricting rib  314  has reached the concave portion  361  and outputs the sensed result to the control portion  105 . 
         [0031]    Subsequently, a description will be made of how to assemble the opening and closing device  30 . The cover  20  is disposed so that the pair of support elements  21  and  22  may be positioned on the back side of the cover  20 . The cover gear  31  is disposed on the outside of the support element  21 . The cover gear  31  is disposed so that the support element  21  may be held between the body portion  313 A of the restricting rib  313  and the body portion  314 A of the restricting rib  314 . The restricting rib  314  is disposed at the front side while the restricting rib  313  is disposed at the back side. 
         [0032]    The twisted coil spring  33  is stretched between the support element  21  and the cover gear  31 . The penetrating ports  21 A and  22 A of the pair of support elements  21  and  22 , and the coil portion  331  of the twisted coil spring  33 , along with the penetrating port  312  of the cover gear  31 , may be preferably penetrated coaxially by a rotating shaft, into the penetrating port  312 , the coil portion  331 , and the penetrating ports  21 A and  22 A in that order. It is to be noted that the pair of support elements  21  and  22  and the cover gear  31  may be penetrated by separate shafts on different axes. By penetrating the pair of support elements  21  and  22  and the cover gear  31  coaxially, rotation can be effectively transmitted from the cover gear  31  to the support element  21 . 
         [0033]    The arm  332  of the twisted coil spring  33  is mounted on the outer surface of the support element  21 , whereas the arm  333  is mounted on the inner surface of the cover gear  31 . 
         [0034]    The pair of sensors  35  and  36  is disposed so that the sensor  35  senses the cover gear  31  when the cover  20  is open and the sensor  36  senses the cover gear  31  when the cover  20  is closed. The cover  20  is positioned in a first position of the present invention when the cover  20  is open and is positioned in a second position of the present invention when the cover  20  is closed. 
         [0035]    The sensor  35  is positioned in an open position in which the protruding portion  313 B of the restricting rib  313  reaches when the cover  20  is open (see  FIG. 4A ). The sensor  36  is positioned in a closed position (which is equivalent to the third position of the present invention) in which the protruding portion  314 B of the restricting rib  314  reaches when the cover gear  31  rotates only by a predetermined angle (see  FIG. 4C ) from a state in which the cover  20  is closed (see  FIG. 4B ). In the state in which the cover  20  is closed, the protruding portion  314 B of the restricting rib  314  reaches a relaying position. 
         [0036]    As shown in  FIG. 5 , the image forming apparatus  100  further includes a reading portion  101 , a storage portion  102 , a holding portion  103 , an image forming portion  104 , and the control portion  105  and the like in the main body portion  120 . The reading portion  101  reads data from a memory card and an optical disc. The storage portion  102  temporarily stores the data read by the reading portion. The holding portion  103  holds a sheet for a photographic image waiting to be processed for image formation. It should be noted that the holding portion  103  may hold not only the sheet for a photographic image but also a plain sheet waiting to be processed for image formation. 
         [0037]    The image forming portion  104  performs an image formation process by various known methods such as a sublimation type thermal transfer method and an inkjet printing method on a sheet for a photographic image, which is held in the holding portion  103 , by using the data temporarily stored in the storage portion  102 . By the sublimation type thermal transfer method, ink is sublimated by heating an ink ribbon to which solid ink of cyan, magenta, and yellow is applied by using a print head, and the ink is made to adhere to the sheet for a photographic image, coated with a polyester resin. By the inkjet method, magenta ink, cyan ink, yellow ink, and black ink are pressurized and discharged from a printer nozzle, the discharge direction of the discharged ink is changed by a deflecting electrode plate, and the ink is sprayed on the sheet for a photographic image. 
         [0038]    The control portion  105  controls each functional portion. 
         [0039]    As shown in  FIG. 6 , the control portion  105 , when sensing that a memory card or an optical disc is inserted into the insertion opening  131 A or  132 A (S 11 ), performs a closing process of the cover  20  as shown in  FIG. 7  (S 12 ). The control portion  105  reads data from the memory card or the optical disc by the reading portion  101 , temporarily stores the data in the storage portion  102 , and displays the temporarily stored data on the monitor  110  (S 13 ). The control portion  105  waits until selection of the data to be printed is accepted (S 14 ). The control portion  105 , when the data to be printed is selected, waits until a print start command is accepted (S 15 ). 
         [0040]    The control portion  105 , when accepting no print start command, performs an opening process of the cover  20  (S 20 ) and, when accepting the print start command, displays printing charge on the monitor and waits until money is received by the coin receiving port  121  or the bill receiving port  122  (S 16 ). 
         [0041]    The control portion  105 , when money is received, performs the image formation process by the image forming portion  104  to the sheet for a photographic image, held by the holding portion  103  by using the selected data to be printed (S 17 ), and outputs a photograph after the image formation process to the output port  124  (S 18 ). The control portion  105  settles the payment based on the received amount of money and the printing charge, and ejects a change to the money ejection port  123  (S 19 ), and performs the opening process of the cover  20  (S 20 ). 
         [0042]    Subsequently, a description will be made of the closing process of the cover  20 . As shown in  FIG. 7 , the control portion  105 , in a state (see  FIG. 4A ) in which the cover  20  is open, rotates the motor  34  in the forward direction (S 21 ). 
         [0043]    The forward rotation of the motor  34  is supplied to the circular arc shaped gear  311  of the cover gear  31  through the gear  32 . The cover gear  31  rotates in the closing direction from the open position to the closed position when the forward rotation of the motor  34  is supplied to the cover gear  31 . The support element  21  is biased in the closing direction by the twisted coil spring  33  biased in a contracting direction. As a result, the cover  20 , as the cover gear  31  rotates in the closing direction, rotates in the closing direction in a state in which the support element  21  contacts the body portion  314 A of the restricting rib  314  of the cover gear  31  by the twisted coil spring  33 . 
         [0044]    The control portion  105  waits until the sensor  36  senses that the cover gear  31  rotates in the closing direction by a predetermined angle and the protruding portion  314 B of the restricting portion  314  reaches the closed position through a state (refer to  FIG. 4B ) in which the cover gear  31  has reached the relaying position and the cover  20  is closed (S 22 ). 
         [0045]    While the protruding portion  314 B moves from the relaying position to the closed position, the cover  20  cannot rotate in the closing direction and only the cover gear  31  rotates in the closing direction. As a result, the support element  21  of the cover  20  is displaced from a state in which the one end of the support element  21  contacts the body portion  313 A to a state in which the other end of the support element  21  contacts the body portion  314 A. The twisted coil spring  33  is biased in the contracting direction by a force greater than the biasing force in the state in which the cover  20  is open. 
         [0046]    The control portion  105 , sensing that the protruding portion  314 B has reached the closed position (see  FIG. 4C ), stops the forward rotation of the motor  34  (S 23 ). 
         [0047]    When the motor  34  stops the forward rotation, the cover gear  31  rotates in the opening direction from the closed position to the open position by the twisted coil spring  33  biased in the contracting direction since a force rotating in the closing direction is not applied to the cover gear  31 , and is displaced to the relaying position in a state in which the cover gear  31  contacts the support element  21  of the cover  20  (see  FIG. 4B ). The cover  20  is fixed so as not to be rotated by the twisted coil spring  33  and the body portion  313 A of the restricting rib  313 . 
         [0048]    As described above, even if a stop position in which the motor  34  stops the forward rotation deviates, the opening and closing device  30  absorbs the forward rotation of the motor  34  by the cover gear  31  and the twisted coil spring  33 , so that no load is applied to the motor  34  and the gear  32 . The opening and closing device  30  rotates the cover gear  31  in the closing direction through the forward rotation of the motor  34  in order to securely close the cover  20  even when the motor  34  is rotated in the forward direction after the cover  20  has closed, thus no abnormal noise is generated from the motor  34 . The opening and closing device  30  can rotate, by a predetermined angle, only the cover gear  31  in the closing direction in accordance with the forward rotation of the motor  34 , thus, if a finger is caught while the cover  20  is being closed from a state in which the cover  20  is open (see  FIG. 4A ), the finger can easily be pulled out of the cover  20 . 
         [0049]    Subsequently, a description will be made of the opening process of the cover  20 . As shown in  FIG. 8 , the control portion  105 , in a state in which the cover  20  is closed (see  FIG. 4B ), rotates the motor  34  in the backward direction (S 31 ). 
         [0050]    The backward rotation of the motor  34  is supplied to the circular arc shaped gear  311  of the cover gear  31  through the gear  32 . The cover gear  31  rotates in the opening direction from the relaying position (see  FIG. 4B ) to the open position when the backward rotation of the motor  34  is supplied to the cover gear  31 . The cover  20  is biased in the closing direction by the twisted coil spring  33  biased in the contracting direction. As a result, the cover  20 , as the cover gear  31  rotates in the opening direction, rotates in the opening direction in a state in which the support element  21  contacts the body portion  314 A of the restricting rib  314  of the cover gear  31  by the twisted coil spring  33 . 
         [0051]    The control portion  105  waits until the sensor  35  senses that the protruding portion  313 B of the restricting rib  313  reaches the open position (S 32 ). The control portion  105  stops the backward rotation of the motor  34  when sensing that the protruding portion  313 B has reached the open position (S 33 ). 
         [0052]    When the motor  34  stops the backward rotation, a force for rotating in the opening direction is not applied to the cover gear  31 . The cover  20  is fixed so as not to be rotated by the twisted coil spring  33  and the body portion  314 A of the restricting rib  314 . 
         [0053]    It is to be noted that, in place for the twisted coil spring  33 , as shown in  FIG. 9A , a spring (which is equivalent to the biasing element of the present invention)  40  may be contracted and provided between the support element  21  of the cover  20  and the body portion  313 A of the restricting rib  313 . In addition, as shown in  FIG. 9B , a spring (which is equivalent to the biasing element of the present invention)  41  may be stretched and provided between the support element  21  of the cover  20  and the body portion  314 A of the restricting rib  314 . 
         [0054]    The above described embodiments are to be considered in all respects as illustrative and not restrictive. The scope of the present invention is defined not by above described embodiments but by the claims. Further, the scope of the present invention is intended to include all modifications that come within the meaning and scope of the claims and any equivalents thereof.