Patent Publication Number: US-2013236166-A1

Title: Waterproof case for camera and waterproof structure for camera using the waterproof case

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to Japanese Patent Application No. 2012-051862. The entirety of Japanese Patent Application No. 2012-051862 is incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a waterproof structure for a camera in which a lens barrel is detachably attached to a camera body, such as a camera including a retractable lens barrel, a single-lens reflex camera and a mirrorless interchangeable lens camera. 
     2. Description of Related Art 
     To realize waterproof or dripproof (hereinafter “waterproof”) of the camera, it is conventionally proposed to waterproof a casing configuring a camera body and a lens barrel. 
     However, in such a camera, although shooting is carried out while exchanging a plurality of lens barrels in accordance with a shooting scene, it is necessary to use special lens barrels having waterproof structures as the plurality of lens barrels, and there is a problem that general versatility of the lens barrels is poor. 
     Hence, it has been proposed to waterproof a camera by a rubber waterproof case accommodating the entire camera in which a lens barrel is detachably attached to a camera body. According to such a waterproof case, even if a camera includes a general lens barrel having no waterproof structure, it is possible to waterproof the camera. 
     However, according to the waterproof structure for a camera using the rubber waterproof case, since an outer shape and a size of the camera body differ depending upon a camera model, it is necessary to prepare a waterproof case having different outer shape and size for every camera model. Further, in the case of a camera in which a lens barrel is detachable and a zoom adjustment operation is carried out by rotating a zoom ring, it is difficult to rotate and operate the zoom ring through the waterproof case, and there is a problem that usage is limited to a camera in which a camera body is provided with a zoom operation key. 
     Hence, it is an object of the present invention to provide a waterproof structure for a camera in which it is possible to waterproof a camera including a general lens barrel having no waterproof structure and in which a zoom ring of the lens barrel can easily be rotated and operated. 
     SUMMARY OF THE INVENTION 
     A waterproof case for a camera according to the present invention is used for a camera in which a lens barrel including a zoom ring for a zoom operation is detachably attached to a camera body. 
     The waterproof case includes a cylindrical case body in which the lens barrel attached to the camera body can be accommodated, the case body includes a fixed cylindrical member which is detachably attached to the camera body, a rotating cylindrical member which is relatively rotatably connected to a front opening of the fixed cylindrical member coaxially with the fixed cylindrical member, and a movable cylindrical member which is accommodated in the rotating cylindrical member and which is disposed such that the movable cylindrical member can reciprocate along a cylindrical shaft of the rotating cylindrical member, and a transparent plate closes a front opening of the movable cylindrical member. 
     An annular first seal portion surrounding the cylindrical shaft of the case body is provided on a bonding portion of the fixed cylindrical member with respect to the camera body, an annular second seal portion surrounding the cylindrical shaft of the case body is provided on a bonding portion of the fixed cylindrical member with respect to the rotating cylindrical member, and an annular third seal portion surrounding the cylindrical shaft of the case body is provided on a bonding portion between the rotating cylindrical member and the movable cylindrical member. 
     An engaging surface which comes into contact with an outer peripheral surface of the zoom ring of the lens barrel and rotates the zoom ring integrally with the rotating cylindrical member is provided on an inner peripheral surface of the rotating cylindrical member. 
     A converting mechanism which converts rotation of the rotating cylindrical member into a reciprocating movement of the movable cylindrical member is interposed between the rotating cylindrical member and the movable cylindrical member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a retracted state of a waterproof case in an embodiment of a camera according to the present invention; 
         FIG. 2  is a perspective view showing a projected state of the waterproof case in the camera; 
         FIG. 3  is a perspective view showing an unlocked state of the waterproof case in the camera; 
         FIG. 4  is a perspective view showing a state where a waterproof case is detached from the camera; 
         FIG. 5  is a perspective view of a camera body to which a lens barrel is attached; 
         FIG. 6  is a perspective view showing a state where the lens barrel is detached from the camera body; 
         FIG. 7  is a vertical sectional view of the camera in the retracted state of the waterproof case; 
         FIG. 8  is a vertical sectional view of the camera in the projected state of the waterproof case; 
         FIG. 9  is a diagram showing a cam groove formed in a rotating cylindrical member of the waterproof case; 
         FIG. 10  is a diagram showing a process in which a cam follower of a movable cylindrical member relatively moves along a cam groove of a rotating cylindrical member of the waterproof case; 
         FIG. 11  is an exploded perspective view showing a configuration of a rear side of the waterproof case; 
         FIG. 12  is an exploded perspective view showing a configuration of a front side of the waterproof case; 
         FIG. 13  is an enlarged sectional view of a first seal portion; 
         FIG. 14  is an enlarged sectional view of a second seal portion; 
         FIG. 15  is an enlarged sectional view of a third seal portion; 
         FIG. 16  is a horizontal sectional view showing a connecting portion between a camera body, a lens barrel and the waterproof case; 
         FIG. 17  is an enlarged sectional view of a locking/unlocking mechanism; 
         FIG. 18  is a perspective view showing a locking/unlocking mechanism provided in a cabinet front portion of the camera body; 
         FIG. 19  is an exploded perspective view of the locking and unlocking mechanism and a lens barrel bonding portion of the camera body as viewed from a rear surface side of the cabinet front portion; 
         FIG. 20  is an exploded perspective view of the locking and unlocking mechanism as viewed from a front surface side of the cabinet front portion; and 
         FIG. 21  is an exploded perspective view of the lens barrel bonding portion of the camera body as viewed from the front surface side of the cabinet front portion. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment in which the present invention is applied to a digital camera will be described specifically along the drawings. In the following description, a shooting direction of the digital camera is called front or forward and an opposite direction is called rear, back or rearward. A term “waterproof” includes a conception of “dripproof”. 
     As shown in  FIGS. 5 and 6 , a digital camera which is an embodiment of the present invention includes a camera body  1  and a lens barrel  2  detachably attached to a cabinet front portion  12  of the camera body  1 . As shown in  FIGS. 1 to 4 , the digital camera also includes a waterproof case  3  which is detachably attached to the cabinet front portion  12  of the camera body  1  and in which the lens barrel  2  is accommodated. 
     As shown in  FIG. 6 , a shooting window  16  through which a light beam from the lens barrel  2  is taken into the camera body  1  opens at the cabinet front portion  12  of the camera body  1 . A lens barrel fixing ring  5  which surrounds the shooting window  16  to attach the lens barrel  2 , and a case fixing ring  6  for attaching the waterproof case  3  are disposed on the cabinet front portion  12 . 
     An unlocking button  11  which is operated when detaching the lens barrel  2  and the waterproof case  3  from the camera body  1  is disposed on the cabinet front portion  12  of the camera body  1 . 
     A casing configuring the camera body  1  (excluding shooting window  16 ) has a waterproof structure. Known structures which are conventionally used for casings of various kinds of electronic devices can be employed as the waterproof structure. 
     The lens barrel  2  includes a fixed lens barrel portion  21  which is to be detachably attached to the lens barrel fixing ring  5  of the camera body  1 , a movable lens barrel portion  22  which is disposed coaxially with the fixed lens barrel portion  21  and which can reciprocate along a cylindrical shaft of the fixed lens barrel portion  21 , and a zoom ring  23  which is rotatably disposed coaxially with the fixed lens barrel portion  21 . The movable lens barrel portion  22  reciprocates in the longitudinal direction in connection with rotation of the zoom ring  23 . The smallest zoom ratio is set at a position (W end) where the movable lens barrel portion  22  most retracts, and the greatest zoom ratio is set at a position (T end) where the movable lens barrel portion  22  most advances. 
     An outer peripheral surface of the zoom ring  23  is formed of cylindrical resilient member so that the zoom ring  23  can easily be rotated and operated by friction resistance caused when a finger is put on the outer peripheral surface. 
     An O-ring  42  shown in  FIG. 13  is fitted into a recess formed in an opposed surface of the fixed lens barrel portion  21  which is opposed to the camera body  1 . 
     In the lens barrel  2 , if the zoom ring  23  is rotated and the movable lens barrel portion  22  is made to reciprocate in the longitudinal direction, a zoom adjustment can be carried out. 
     As shown in  FIGS. 7 and 8 , the waterproof case  3  includes a cylindrical case body  39  in which the lens barrel  2  attached to the camera body  1  can be accommodated. The case body  39  is made of synthetic resin. The case body  39  includes a fixed cylindrical member  31  which can detachably be attached to the camera body  1 , a rotating cylindrical member  32  which is relatively rotatably connected an open end of the fixed cylindrical member  31  coaxially with the fixed cylindrical member  31 , and a movable cylindrical member  9  which is accommodated in the rotating cylindrical member  32  and which can reciprocate along the cylindrical shaft of the rotating cylindrical member  32 . A transparent plate  30  is adhered and fixed to a front open end of the movable cylindrical member  9 . 
     If the rotating cylindrical member  32  of the waterproof case  3  is rotated, the movable cylindrical member  9  reciprocates in the longitudinal direction. 
     As shown in  FIGS. 11 and 14 , a ring member  33  made of synthetic resin is fitted into the fixed cylindrical member  31  configuring the waterproof case  3 . The ring member  33  includes a cylindrical portion  33   a  and a disk portion  33   b . The ring member  33  is fastened to the rotating cylindrical member  32  by screwing three screws  35  from the disk portion  33   b  into bosses  34  of the rotating cylindrical member  32 . 
     As shown in  FIG. 14 , a front end portion  31   a  of the fixed cylindrical member  31  is sandwiched between a rear end of the rotating cylindrical member  32  and the ring member  33  under pressure. According to this configuration, the fixed cylindrical member  31  and the rotating cylindrical member  32  are relatively rotatably and coaxially connected to each other. 
     A cylindrical surface-shaped engaging surface  37  which should be brought into contact, under pressure, with an outer peripheral surface  26  of the zoom ring  23  of the lens barrel  2  is formed on an inner peripheral surface of the cylindrical portion  33   a  of the ring member  33 . The outer peripheral surface  26  of the zoom ring  23  and the engaging surface  37  of the ring member  33  are formed into tapered surfaces whose diameters are slightly reduced forwardly. An outer diameter of the outer peripheral surface  26  of the zoom ring  23  is slightly greater than an inner diameter of the engaging surface  37  of the ring member  33 . 
     A plurality of protruding portions (not shown) extending in the cylindrical shaft direction of the ring member  33  is formed on the engaging surface  37  of the ring member  33 . The outer peripheral surface  26  of the zoom ring  23  is slightly resiliently deformed by bringing the engaging surface  37  into contact with the outer peripheral surface  26  of the zoom ring  23  under pressure. The outer peripheral surface  26  of the zoom ring  23  and the engaging surface  37  of the ring member  33  are in contact with each other under pressure while creating friction resistance. As the rotating cylindrical member  32  rotates, the zoom ring  23  can integrally rotate. 
     An O-ring  41  extending to surround a front end portion  31   a  of the fixed cylindrical member  31  is provided on a bonding portion between the fixed cylindrical member  31  and the rotating cylindrical member  32  of the waterproof case  3 . The O-ring  41  is sandwiched between the fixed cylindrical member  31  and the rotating cylindrical member  32  under pressure. The O-ring  41  configures a seal portion (second seal portion) which waterproofs between the fixed cylindrical member  31  and the rotating cylindrical member  32 . 
     While the rotating cylindrical member  32  rotates with respect to the fixed cylindrical member  31 , the O-ring  41  slides on any of cylindrical members, and allows the rotating cylindrical member  32  to rotate while keeping the waterproof ability. 
     The fixed cylindrical member  31  configures the waterproof case  3 . As shown in  FIGS. 11 and 13 , an O-ring  4  extending to surround the cylindrical shaft of the fixed cylindrical member  31  is fitted into an annular recess portion  31   b  formed in a surface of the fixed cylindrical member  31  which is opposed to the camera body  1 . 
     As shown in  FIG. 11 , a cylindrical portion  97  having a diameter which is slightly smaller than that of the front end portion  31   a  projects from a front end portion  31   a  of the fixed cylindrical member  31 . Three guide grooves  98 ,  98 ,  98  extending in the direction of the cylindrical shaft are formed in an outer peripheral surface of the cylindrical portion  97  at 120° phase intervals from one another. 
     As shown in  FIG. 12 , the rotating cylindrical member  32  has an inner diameter which is slightly greater than an outer diameter of the cylindrical portion  97  of the fixed cylindrical member  31 , and has an outer diameter which is equal to that of the fixed cylindrical member  31 . Three cam grooves  95 ,  95 ,  95  spirally extending around the cylindrical shaft are formed in the inner peripheral surface of the rotating cylindrical member  32  at 120° intervals from one another. 
     The movable cylindrical member  9  has an outer diameter which is slightly smaller than an inner diameter of the rotating cylindrical member  32 . The movable cylindrical member  9  is accommodated in the rotating cylindrical member  32  such that the movable cylindrical member  9  can rotate and reciprocate. Three cam followers  93 ,  93 ,  93  which outwardly and radially project are formed on a rear end edge of an outer peripheral surface of the movable cylindrical member  9  at 120° phase intervals from one another. Three protrusions  94 ,  94 ,  94  extending in the direction of the cylindrical shaft are formed on an inner peripheral surface of the movable cylindrical member  9  at 120° phase intervals from one another. 
     The movable cylindrical member  9  has an inner diameter which is slightly greater than an outer diameter of the cylindrical portion  97  of the fixed cylindrical member  31 . 
     The cam followers  93  of the movable cylindrical member  9  are slidably engaged with the cam grooves  95  of the rotating cylindrical member  32  in a state where the movable cylindrical member  9  is accommodated in the rotating cylindrical member  32 . 
     The protrusions  94 ,  94 ,  94  of the movable cylindrical member  9  are slidably engaged with the guide grooves  98 ,  98 ,  98  of the cylindrical portion  97  of the fixed cylindrical member  31  in a state where the movable cylindrical member  9  is accommodated in the rotating cylindrical member  32  and the cylindrical portion  97  of the fixed cylindrical member  31  is accommodated in the movable cylindrical member  9 . 
     Therefore, the movable cylindrical member  9  is connected to the fixed cylindrical member  31  such that the movable cylindrical member  9  can not rotate and can reciprocate in the direction of the cylindrical shaft. The rotating cylindrical member  32  is connected to the fixed cylindrical member  31  such that the rotating cylindrical member  32  can not move in the direction of the cylindrical shaft and can rotate around the cylindrical shaft. 
     As shown in  FIG. 9 , each of the cam grooves  95  of the rotating cylindrical member  32  includes a horizontal portion  951  extending such that the cam groove  95  intersects with the cylindrical shaft of the fixed cylindrical member  31  at right angles, and an inclined portion  952  extending from one end edge of the horizontal portion  951  such that the inclined portion  952  inclines with respect to the cylindrical shaft. 
     As shown in  FIG. 10 , if the rotating cylindrical member  32  is rotated in a counterclockwise direction, the cam follower  93  moves from a start end position  93   a  of the horizontal portion  951  of the cam groove  95  to a terminal end position  93   c  of the inclined portion  952  through a boundary position  93   b  between the horizontal portion  951  and the inclined portion  952 . 
     Here, the start end position  93   a  of the horizontal portion  951  of the cam groove  95  becomes a set position where the waterproof case  3  should be attached to the camera body  1 , the boundary position  93   b  between the horizontal portion  951  and the inclined portion  952  becomes the position (W end) where the lens barrel  2  and the waterproof case  3  are most retracted and the smallest zoom ratio is set, and the terminal end position  93   c  of the inclined portion  952  becomes the position (T end) where the lens barrel  2  and the waterproof case  3  are most projected and the greatest zoom ratio is set. 
     As shown in  FIG. 12 , a front surface ring  92  is attached to a front end portion of the rotating cylindrical member  32  through a ring-shaped seal member  45 , four screws  96  are screwed into the front surface ring  92  from the flange  32   a  of the rotating cylindrical member  32 . According to this operation, the front surface ring  92  is fixed to the rotating cylindrical member  32 , and a base end portion of the ring-shaped seal member  45  is sandwiched between the rotating cylindrical member  32  and the front surface ring  92  under pressure. 
     As shown in  FIG. 15 , the ring-shaped seal member  45  includes a cylindrical portion  45   a  covering an outer peripheral surface of the front end portion  32   b  of the rotating cylindrical member  32 , a disk portion  45   b  extending in a form of a ring along an end surface of the front end portion  32   b  of the rotating cylindrical member  32 , and a ring-shaped tongue portion  45   c  extending diagonally toward the outer peripheral surface of the movable cylindrical member  9 . The disk portion  45   b  of the ring-shaped seal member  45  is sandwiched between the rotating cylindrical member  32  and the front surface ring  92 , and a tip end of the tongue portion  45   c  is brought into contact with the outer peripheral surface of the movable cylindrical member  9  under pressure by a resilient repulsion force of the tip end. 
     Therefore, in the process in which the movable cylindrical member  9  reciprocates by rotation of the rotating cylindrical member  32 , the tongue portion  45   c  of the ring-shaped seal member  45  is brought into contact with the outer peripheral surface of the movable cylindrical member  9  under pressure and in this state, the tongue portion  45   c  slides on the outer peripheral surface, and this blocks water entering the case body  39  from a gap between the front surface ring  92  and the movable cylindrical member  9 . 
     A seal portion (third seal portion) is formed between the rotating cylindrical member  32  and the movable cylindrical member  9  by the ring-shaped seal member  45 . 
     In the waterproof case  3 , the cam grooves  95  of the rotating cylindrical member  32  extend such that the cam grooves  95  pivot forward from behind in the counterclockwise direction. Therefore, if the rotating cylindrical member  32  is rotated in the counterclockwise direction toward the camera body  1  as shown by an arrow in  FIG. 1 , the movable cylindrical member  9  moves forward as shown in  FIG. 2 , and if the rotating cylindrical member  32  is rotated in the clockwise direction toward the camera body  1  as shown by an arrow in  FIG. 2 , the movable cylindrical member  9  moves rearward as shown in  FIG. 1 . 
     In this manner, a cam mechanism which converts rotation of the rotating cylindrical member  32  into a reciprocating movement of the movable cylindrical member  9  is configured. 
     As shown in  FIG. 6 , three engaged ribs  51 ,  51 ,  51  extending on an arc at intervals of 120° phase angle from one another project on the lens barrel fixing ring  5 . As shown in  FIG. 13 , three engaging ribs  25 ,  25 ,  25  extending on an arc project on the fixed lens barrel portion  21  of the lens barrel  2  at positions corresponding to the engaged ribs  51 ,  51 ,  51  of the lens barrel fixing ring  5 . 
     The fixed lens barrel portion  21  of the lens barrel  2  is pressed against the lens barrel fixing ring  5  in a predetermined relative angle attitude and in this state, the fixed lens barrel portion  21  is rotated about 30° in the counterclockwise direction and screwed, and the engaging ribs  25  are engaged with the engaged ribs  51 . According to this operation, the lens barrel  2  can detachably be attached to the camera body  1 . 
     This configuration is the same as a configuration for detachably attaching the lens barrel in the conventional camera. 
     By attaching the lens barrel  2  to the camera body  1 , the O-ring  42  disposed on the lens barrel  2  is sandwiched between the fixed lens barrel portion  21  of the lens barrel  2  and the camera body  1  under pressure, and the seal portion is configured between the lens barrel  2  and the camera body  1  by the O-ring  42 . 
     As shown in  FIG. 4 , three engaged ribs  61 ,  61 ,  61  extending on an arc at intervals of 120° phase angle from one another project on the case fixing ring  6 . As show in  FIG. 13 , three engaging ribs  36 ,  36 ,  36  extending on an arc project on the fixed cylindrical member  31  of the waterproof case  3  at positions corresponding to the engaged ribs  61 ,  61 ,  61  of the case fixing ring  6 . 
     As shown in  FIGS. 3 and 4 , in the relative angle attitude in which an index  1   a  provided on the camera body  1  and an index  3   a  provided on the waterproof case  3  match with each other, the fixed cylindrical member  31  of the waterproof case  3  is pressed against the case fixing ring  6  and in this state, the fixed cylindrical member  31  is rotated about 30° in the clockwise direction as shown by an arrow in  FIG. 3  and screwed, and the engaging ribs  36  are engaged with the engaged ribs  61 . According to this operation, the waterproof case  3  can detachably be attached to the camera body  1 . 
     This configuration is the same as a configuration for detachably attaching the lens barrel  2  to the camera body  1 . 
     By attaching the waterproof case  3  to the camera body  1 , the O-ring  4  is sandwiched between the fixed cylindrical member  31  of the waterproof case  3  and the case fixing ring  6  under pressure, and a seal portion (first seal portion) is configured between the fixed cylindrical member  31  and the case fixing ring  6  by the O-ring  4 . 
     An O-ring  43  is interposed between the camera body  1  and the case fixing ring  6 , and a seal portion is configured between the camera body  1  and the case fixing ring  6  by the O-ring  43 . 
     In the process in which the fixed cylindrical member  31  of the waterproof case  3  is rotated about 30° in the clockwise direction to attach the waterproof case  3  to the camera body  1  as shown by an allow in  FIG. 3 , the cam follower  93  of the movable cylindrical member  9  slides on the horizontal portion  951  of the cam groove  95  of the rotating cylindrical member  32 . In this process, the movable cylindrical member  9  does not move irrespective of rotation of the rotating cylindrical member  32 . 
     As the fixed cylindrical member  31  of the waterproof case  3  rotates in the clockwise direction, the rotating cylindrical member  32  also receives a clockwise rotation torque, but the rotating cylindrical member  32  is engaged with the zoom ring  23  of the lens barrel  2  such that the rotating cylindrical member  32  can rotate integrally with the zoom ring  23 , and the zoom ring  23  can not rotate in the clockwise direction any more in the retracted state of the lens barrel  2 . Therefore, the rotating cylindrical member  32  of the waterproof case  3  does not rotate in the clockwise direction. 
     Therefore, in the waterproof case  3 , only the fixed cylindrical member  31  rotates in the clockwise direction in a state where the rotating cylindrical member  32  is prevented from rotating. 
     In this manner, the rotating cylindrical member  32  rotates about 30° in the counterclockwise direction relative to the fixed cylindrical member  31  in the process in which the waterproof case  3  is attached to the camera body  1  but as described above, the cam follower  93  of the movable cylindrical member  9  slides on the horizontal portion  951  of the cam groove  95  of the rotating cylindrical member  32 , and the movable cylindrical member  9  does not move. Therefore, a relative position between the movable lens barrel portion  22  of the lens barrel  2  and the movable cylindrical member  9  of the waterproof case  3  is not changed. 
     Thereafter, the rotating cylindrical member  32  is further rotated in the counterclockwise direction. According to this operation, the cam follower  93  slides on the inclined portion  952  of the cam groove  95  and as the rotating cylindrical member  32  rotates, the movable cylindrical member  9  moves forward. 
     In a state where the cam follower  93  is in slide-contact with the inclined portion  952  of the cam groove  95 , if the rotating cylindrical member  32  is rotated in the counterclockwise direction toward the camera body  1  as shown by the arrow in  FIG. 1 , the movable cylindrical member  9  moves forward as shown in  FIG. 2  and in synchronism with this movement, the movable lens barrel portion  22  of the lens barrel  2  moves forward (see  FIG. 8 ). If the rotating cylindrical member  32  is rotated in the clockwise direction toward the camera body  1  as shown by the arrow in  FIG. 2 , the movable cylindrical member  9  moves rearward in synchronism with this rotation as shown in  FIG. 1  and in synchronism with this movement, the movable lens barrel portion  22  of the lens barrel  2  moves rearward (see  FIG. 7 ). 
     The inclination angle of the inclined portion  952  of the cam groove  95  is determined such that a moving amount of the movable cylindrical member  9  caused by the rotation of the rotating cylindrical member  32  of the waterproof case  3  and a moving amount of the movable lens barrel portion  22  of the lens barrel  2  become equal to or substantially equal to each other. 
     As shown in  FIG. 16 , a locking/unlocking mechanism  7  is disposed on a bonding portion between the cabinet front portion  12 , the lens barrel  2  and the waterproof case  3 . The locking/unlocking mechanism  7  locks the lens barrel  2  and the waterproof case  3  in their attached state, or unlocks the lens barrel  2  and the waterproof case  3 . 
     As shown in  FIGS. 17 to 21 , the locking/unlocking mechanism  7  includes a lens barrel lock pin  72  which is disposed on a bonded surface of the lens barrel fixing ring  5  with respect to the lens barrel  2  such that the lens barrel lock pin  72  can project and retract and which is biased in a projecting direction by a spring  83 , a case lock pin  74  which is disposed on a bonded surface of the case fixing ring  6  with respect to the waterproof case  3  such that the case lock pin  74  can project and retract and which is biased in a projecting direction by a spring  82 , and a pin hole  27  which is formed in a bonded surface of the lens barrel  2  with respect to the lens barrel fixing ring  5  and into which a tip end of the lens barrel lock pin  72  can be fitted, a pin hole  38  which is formed in a bonded surface of the waterproof case  3  with respect to the case fixing ring  6  and into which a tip end of the case lock pin  74  can be fitted, the unlocking button  11  which is disposed on the camera body  1  such that the unlocking button  11  can be pushed down and which is biased in a projecting direction by a spring  8 , a first movable member  71  interposed between the unlocking button  11  and the lens barrel lock pin  72 , and a second movable member  73  interposed between the unlocking button  11  and the case lock pin  74 . 
     One end of the first movable member  71  is integrally connected to the lens barrel lock pin  72 , and the other end of the first movable member  71  is opposed to a lower end surface of a shaft portion  15  of the unlocking button  11 . The other end of the first movable member  71  is biased forward by a spring  81 . 
     A disk packing  40  is interposed between a lower end of the shaft portion  15  of the unlocking button  11  and the other end of the first movable member  71 . The packing  40  can resiliently be deformed in a compressing direction. 
     A washer piece  75  is disposed on the other end of the first movable member  71  on a surface on the side of the unlocking button  11 , and the packing  40  is sandwiched between the shaft portion  15  of the unlocking button  11  and the washer piece  75  by biasing forces of the springs  83 ,  8  under pressure. 
     According to this configuration, the other end of the first movable member  71  presses the unlocking button  11  forward (in projecting direction). 
     One end of the second movable member  73  is integrally connected to the case lock pin  74 , and the other end of the second movable member  73  is opposed to a lower end surface of an outer periphery of the unlocking button  11 . The other end of the second movable member  73  is brought into contact, under pressure, with a lower end surface of the outer periphery of the unlocking button  11  by a biasing force of the spring  82 . 
     According to this configuration, the other end of the second movable member  73  presses the unlocking button  11  forward (in projecting direction). 
     As shown in  FIG. 18 , the cabinet front portion  12  has a laminated structure including a first plate  13  and a second plate  14 . As shown in  FIG. 19 , an attaching portion  19  for the packing  40 , the washer piece  75 , the first movable member  71  and the springs  81  and  83  is formed in a back surface of the first plate  13  in a recessed manner. As shown in  FIG. 20 , an attaching portion  18  for the springs  8  and  82 , the second movable member  73  and the unlocking button  11  is formed in a front surface of the first plate  13  in a recessed manner. 
     As shown in  FIGS. 19 and 21 , a circular window  17  from which a front surface of the lens barrel fixing ring  5  is exposed and a circular hole  10  from which a head of the unlocking button  11  is exposed are formed in the second plate  14 , and a circular hole  54  is formed in a holding piece  53  projecting on the lens barrel fixing ring  5 . A head of the unlocking button  11  penetrates through the circular hole  54 . 
     An O-ring  44  is interposed between the lens barrel fixing ring  5  and the first plate  13 . 
     As shown in  FIG. 17 , according to the locking/unlocking mechanism  7 , there is a possibility that water enters from a gap between the unlocking button  11  and the cabinet front portion  12  but the packing  40  and the O-ring  43  prevent water from entering the camera body  1 . 
     In the locking/unlocking mechanism  7 , if only the lens barrel lock pin  72  is pushed toward the camera body  1 , only the first movable member  71  retracts and the case lock pin  74  does not retract at the same time. If only the case lock pin  74  is pushed toward the camera body  1 , only the second movable member  73  retracts and the lens barrel lock pin  72  does not retract at the same time. 
     If the unlocking button  11  is pressed down, the first movable member  71  and the second movable member  73  are pressed down, and according to this motion, the lens barrel lock pin  72  and the case lock pin  74  retract at the same time. 
     In this camera, to attach the lens barrel  2  to the camera body  1 , if the lens barrel  2  is pressed against the lens barrel fixing ring  5  of the camera body  1  in a predetermined relative angle attitude, the lens barrel lock pin  72  is pressed down and retracted by the lens barrel  2 . 
     In this state, if the lens barrel  2  is rotated about 30° in the counterclockwise direction and is screwed into the lens barrel fixing ring  5 , the lens barrel  2  is connected to the camera body  1 . At this point, the lens barrel lock pin  72  of the camera body  1  is opposed to the pin hole  27  of the lens barrel  2 , and the lens barrel lock pin  72  is biased by the spring  83  and fitted into the pin hole  27 . 
     As a result, rotation of the lens barrel  2  is restrained and the lens barrel  2  is locked on the camera body  1 . 
     Thereafter, to attach the waterproof case  3  to the camera body  1 , if the waterproof case  3  is pressed against the case fixing ring  6  of the camera body  1  in a predetermined relative angle attitude, the case lock pin  74  is pressed down and retracted by the waterproof case  3 . At that time, since the lens barrel lock pin  72  does not retract at the same time, the locked state of the lens barrel  2  is not released. 
     In this state, if the waterproof case  3  is rotated about 30° in the clockwise direction and screwed into the case fixing ring  6 , the waterproof case  3  is connected to the camera body  1 . At this point, the case lock pin  74  of the camera body  1  is opposed to the pin hole  38  of the waterproof case  3 , and the case lock pin  74  is biased by the spring  82  and fitted into the pin hole  38 . 
     As a result, the waterproof case  3  is locked on the camera body  1 . 
     Even if the lens barrel  2  receives a clockwise rotation torque when the waterproof case  3  rotates, since the lens barrel  2  is locked, the screwed lens barrel  2  does not loosen. 
     By attaching the lens barrel  2  and the waterproof case  3  to the camera body  1  in this manner, the lens barrel  2  is accommodated in the case body  39  of the waterproof case  3  as shown in  FIG. 7 . 
     The engaging surface  37  provided on the inner peripheral surface of the rotating cylindrical member  32  of the waterproof case  3  is brought into contact with the outer peripheral surface  26  of the zoom ring  23  of the lens barrel  2  under pressure. 
     In this state, if a finger is put on the rotating cylindrical member  32  of the waterproof case  3  and the rotating cylindrical member  32  is rotated around the cylindrical shaft, the zoom ring  23  rotates integrally with the rotating cylindrical member  32 , this rotation reciprocates the movable lens barrel portion  22  of the lens barrel  2  with respect to the fixed lens barrel portion  21  in the cylindrical shaft direction, and the zoom adjustment is carried out. 
     Since the transparent plate  30  is adhered and fixed to a front open end of the rotating cylindrical member  32 , water does not enter from between the rotating cylindrical member  32  and the transparent plate  30 . The first seal portion using the O-ring  4  waterproofs the bonding portion between the lens barrel  2  and the camera body  1 , and the second seal portion using the O-ring  41  waterproofs between the fixed cylindrical member  31  and the rotating cylindrical member  32  of the lens barrel  2 . A space between the rotating cylindrical member  32  and the movable cylindrical member  9  is waterproofed by the third seal portion using the ring-shaped seal member  45 . 
     Therefore, even if the lens barrel  2  is a general lens barrel having no waterproof structure, if the waterproof case  3  is attached, it is possible to waterproof the bonding portion between the lens barrel  2  and the camera body  1  of the lens barrel  2 . 
     By rotating the rotating cylindrical member  32  of the waterproof case  3 , the zoom ring  23  of the lens barrel  2  can be rotated through the same angle as the rotation angle of the rotating cylindrical member  32 . Therefore, the zoom adjustment becomes easy. 
     When the waterproof case  3  is to be detached, the unlocking button  11  is pressed down. According to this movement, the lens barrel lock pin  72  and the case lock pin  74  of the camera body  1  retract at the same time, these pins are pulled out from the pin hole  27  of the lens barrel  2  and the pin hole  38  of the waterproof case  3 , the locked states of the lens barrel  2  and the waterproof case  3  are released, and the lens barrel  2  and the waterproof case  3  are allowed to rotate. 
     In this state, by rotating the fixed cylindrical member  31  of the waterproof case  3  abut 30° in the counterclockwise direction, the connection between the waterproof case  3  and the camera body  1  is released and they can be detached from each other. At that time, even if the lens barrel  2  receives a counterclockwise rotation torque when the waterproof case  3  rotates, the screwed lens barrel  2  does not loosen. 
     Thereafter, when the lens barrel  2  is to be detached from the camera body  1 , the fixed lens barrel portion  21  of the lens barrel  2  is rotated about 30° in the clockwise direction while pressing down the unlocking button  11  of the camera body  1 . According to this operation, the lens barrel  2  can be detached. 
     According to this camera, as shown in  FIGS. 7 and 8 , it is possible to design such that lengths of the waterproof case  3  in the retracted state and the projected state in the direction of the cylindrical shaft become slightly greater than lengths of the lens barrel  2  in the retracted state and the projected state in the direction of the cylindrical shaft. According to this design avoids a case where the inner peripheral surface of the movable cylindrical member  9  is included in an angle of view at the time of a shooting operation in a state where the waterproof case  3  is attached, especially at the time of a shooting operation in a state (retracted state) where the movable lens barrel portion  22  of the lens barrel  2  is retracted. 
     Further, at the time of a normal shooting operation requiring no waterproof, the locked state of the waterproof case  3  is released by operating the unlocking button  11  and the waterproof case  3  can be detached. Therefore, the troublesome operation is unnecessary. 
     The locked state of the waterproof case  3  and the locked state of the lens barrel  2  are released by means of the common unlocking button  11 . Therefore, the number of the unlocking buttons is reduced as compared with a case where the unlocking buttons are prepared for the waterproof case  3  and the lens barrel  2 , and the configuration of the locking/unlocking mechanism  7  becomes simple. 
     Incidentally, the configuration of each of the constituent parts according to the present invention is not limited to those described preferred embodiment. Various changes can be made by those skilled in the art within the range not departing from the spirit of the present invention. 
     For example, the configuration for rotating the zoom ring  23  of the lens barrel  2  integrally with the rotating cylindrical member  32  of the waterproof case  3  is not limited to the pressure contact structure between the outer peripheral surface  26  of the zoom ring  23  and the engaging surface  37  of the ring member  33  of the waterproof case  3 , and it is possible to employ various engaging structures such as a fitting structure of convex and concave portions, and a meshing structure of tooth surfaces.