Abstract:
A camera includes a rotatable zoom lens barrel which moves along an optical axis when rotated about the optical axis relative to a camera body. A motor having a drive shaft and a motor accommodating member in which the motor is provided, are positioned in the camera body. A gear train for transmitting rotation of the drive shaft to the zoom lens barrel, and a gear train accommodating member in which at least part of the gear train is provided, are positioned in the camera body. A battery chamber in which a battery may be loaded is positioned in the camera body. The motor accommodating member, the gear train accommodating member and the battery chamber are formed as one unit to be secured to the camera body.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a camera having a motor-driven zoom lens incorporated with the camera. 
     2. Description of the Related Art 
     In a conventional camera having a motor-driven zoom lens incorporated therewith, a zoom lens drive mechanism portion which includes a zooming motor and a gear train, a battery chamber for accommodating a battery for supplying electric power to the zooming motor, and other portions of the camera are separately provided as independent parts of the camera body (main body). These portions are individually fixed to the camera body in assembly of the camera. 
     However, it is not easy to space-efficiently design and arrange these portions within the camera, which makes it difficult to design the camera small and compact. Furthermore, it is time-consuming as these portions need to be fixed to the camera body individually. 
     SUMMARY OF THE INVENTION 
     The primary object of the present invention is to provide a camera having a motor-driven zoom lens which has an interior structure that enables a small and compact camera design and also facilitates the assembly of the camera. 
     To achieve the object mentioned above, according to an aspect of the present invention, there is provided a camera including: a rotatable zoom lens barrel which moves along an optical axis when rotated about the optical axis relative to a camera body; a motor having a drive shaft; a motor accommodating member, positioned in the camera body, in which the motor is provided; a gear train for transmitting rotation of the drive shaft to the zoom lens barrel; and a gear train accommodating member, positioned in the camera body, in which at least part of the gear train is provided; and a battery chamber, positioned in the camera body, in which a battery is loaded, wherein the motor accommodating member, the gear train accommodating member and the battery chamber are formed as one unit to be secured to the camera body. 
     Preferably, the motor accommodating member is formed to correspond to a shape of the motor. 
     Preferably, the motor is in the shape of a cylinder, the motor accommodating member being formed having a substantially cylindrical shape. 
     Preferably, the battery includes at least one cylindrical cell, the battery chamber being formed having a substantially cylindrical shape. 
     Preferably, the gear train accommodating member includes a plurality of small stub-axles on which corresponding gears of the gear train are rotatably fitted. 
     Preferably, the camera includes a cylindrical film chamber, the unit being positioned adjacent to the film chamber so that the axis of the cylindrical shape of the motor accommodating member extends substantially parallel to the axis of the cylindrical film chamber. 
     Preferably, the camera includes a cylindrical film chamber, the unit being positioned adjacent to the film chamber such that the axis of the cylindrical shape of the battery chamber extends substantially parallel to an axis of the film chamber. 
     Preferably, the gear train accommodating member is positioned between the zoom lens barrel and the zoom motor accommodating member. 
     Preferably, the camera body includes a grip portion, the unit being positioned inside the grip portion. 
     According to another aspect of the present invention, there is provided a camera having a zoom lens barrel driven by a motor to perform zooming, the camera including: a gear train for transmitting rotation of the motor to the zoom lens barrel; and an accommodating unit, provided as a separate part from the camera body of the camera, which is to be secured to the camera body when the camera is assembled, the accommodating unit including: a motor acommodating portion for accommodating the motor; a gear train accommodating portion for accommodating the gear train; and a battery chamber. 
     Preferably, the camera body includes a grip portion, the accommodating unit being positioned inside the grip portion. 
     Preferably, the camera body includes a film chamber, the accommodating unit being positioned in front of, and adjacent to, the film chamber. 
     The present disclosure relates to subject matter contained in Japanese Patent Application No. 9-346180 (filed on Dec. 16, 1997) which is expressly incorporated herein by reference in its entirety. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be described below in detail with reference to the accompanying drawings in which: 
     FIG. 1 is a front view of part of the interior of a camera having a motor-driven zoom lens to which the present invention is applied; 
     FIG. 2 is a cross sectional view of part of the camera, taken along the II—II line shown in FIG. 1; and 
     FIG. 3 is an exploded perspective view of an accommodating unit and related parts accommodated and supported by the accommodating unit. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     A camera  10  having a camera body  11  is provided, at the approximate center of the front thereof, with a zoom lens barrel  12 . The zoom lens barrel  12  is provided around the outer periphery thereof with a large-diameter zoom gear  12   a.  The zoom lens barrel  12  advances from and retracts into the camera body  11  along an optical axis O to change the focal length when the zoom gear  12   a  is driven to rotate in forward and reverse directions, respectively. 
     As shown in FIG. 2, part of the front of the camera body  11  bulges forwardly (downwardly as viewed in FIG. 2) to form a grip portion  13  of the camera  10 . The camera  10  is provided, behind the front of the grip portion  13  within the camera body  11 , with a film chamber  15  in which a film cassette  14  is accommodated. The camera body  11  is provided on the back thereof with a back lid (not shown), and the film cassette  14  is loaded into or taken out of the camera body  11  upon the back lid being opened. The film cassette  14  is appropriately accommodated in the closed space formed by the film chamber  15 , and part of the back lid upon the back lid being closed. When the film cassette  14  is positioned in the film chamber  15 , a film spool  14   a  of the film cassette  14  extends in the vertical direction of the camera body  11 . A leaf spring  16  for pressing the film cassette  14  to stably position the same in the film chamber  15  is fixed to an inner wall of the film chamber  15 . Numeral  17  designates electrical contacts  17  for reading the DX code of the film cassette  14 . 
     The camera  10  is provided in the grip portion  13  with an accommodating unit  20  which is composed of a battery chamber  20   a,  a zooming motor accommodating portion  20   b  and a reduction-gear-train accommodating portion  20   c.  The accommodating unit  20  is made of plastic as an integral member. The accommodating unit  20  is secured to and positioned within the camera body  11  in a space between the front wall of the camera body  11  and the film chamber  15  in forward-rearward direction of the camera body  11  (vertical direction as viewed in FIG. 2) and between the zoom lens barrel  12  and a side wall  11   a  of the camera body  11  in right-left direction of the camera body  11  (horizontal direction as viewed in FIG.  2 ). In a state where the accommodating unit  20  is fixed to the camera body  11 , the reduction-gear-train accommodating portion  20   c,  the zooming motor accommodating portion  20   b  and the battery chamber  20   a  are positioned in this order from one side of the zoom lens barrel  12  toward the side wall  11   a  in the right-left direction of the camera body  11 . The accommodating unit  20  can be directly fixed to any inner stationary part of the camera body  11  or can be fixed to any inner stationary portion of the camera body  11  via; e.g., to a housing secured to the zoom lens barrel  12 . 
     The battery chamber  20   a  has a cylindrical space  22  whose shape corresponds to that of a cylindrical cell  21 . The cylindrical space  22  is formed such that the axis thereof extends substantially parallel to the film spool  14   a,  whereby the cell  21  is accommodated in the battery chamber  20   a  with the axis of the cell  21  extending along the vertical direction of the camera body  11 . The bottom of the battery chamber  20   a  is opened to form a battery insertion opening (not shown) through which the cell  21  can be inserted into the battery chamber  20   a.  The camera  10  is provided at the bottom of the camera body  11  with a battery chamber lid  9  for opening and closing the battery insertion opening. The battery chamber lid  9  is provided on its inner wall with a lower electrical contact (not shown) which contacts one end (positive terminal) of the cell  21  when the battery chamber lid  9  is closed with the cell  21  in the battery chamber  20   a.  The battery chamber  20   a  is provided at its upper end  23  with an upper electrical contact  24  which is in spring contact with the other end (negative terminal) of the cell  21  when the cell  21  is accommodated in the battery chamber  20   a.  The upper and lower electrical contacts are provided as elements of a power source circuit of the camera  10 . 
     The zooming motor accommodating portion  20   b  is provided with a cylindrical space  26  whose shape corresponds to that of a cylindrical zooming motor  25 . The cylindrical space  26  is formed such that the axis thereof extends substantially parallel to the film spool  14   a,  similar to the cylindrical space  22 , wherein the zooming motor  25  is accommodated in the zooming motor accommodating portion  20   b  with the axis of the zooming motor  25  extending along the vertical direction of the camera body  11 . The zooming motor accommodating portion  20   b  is provided at its top with an opening  27  through which the zooming motor can be inserted into the cylindrical space  26 . The zooming motor  25  is positioned in the cylindrical space  26  with a drive shaft  25   a  extending downwards. A worm  28  is fixed on the drive shaft  25   a  to be adjacent to the reduction-gear-train accommodating portion  20   c  so as to be engaged with the large gear (worm wheel) of a composite gear  31   a  positioned in the reduction-gear-train accommodating portion  20   c.  The zooming motor  25  is electrically connected to the aforementioned power source circuit via a zooming control circuit (not shown) provided in the camera  10 . The camera  10  is provided on the camera body  11  with an operational knob or switch (not shown) to effect zooming. In accordance with the operation of the operational knob or switch, the zooming control circuit controls the zooming motor  25  to rotate the drive shaft  25   a  forwardly or reversely or to stop the same by controlling power supply to the zooming motor  25 . 
     As shown in FIG. 2, the film chamber  15  is formed having a part-cylindrical shape, so that a space within the camera body  11  between the bulged front portion of the film chamber  15  and the front wall of the camera body  11  is narrow. The cylindrical space  26 , in which the zooming motor  25  is positioned, is smaller in diameter than the cylindrical space  22 , in which the cell  21  is positioned. The accommodating unit  20  is secured to the camera body  11  with the cylindrical space  26  being positioned in the aforementioned narrow space between the bulged front part of the film chamber  15  and the front wall of the camera body  11 . 
     A plurality of small stub-axles  30   a,    30   b,    30   c,    30   d,    30   f  and  30   g  are formed integrally with the reduction-gear-train accommodating portion  20   c  to extend substantially parallel to the optical axis O. Composite gears  31   a,    31   b,    31   c  and  31   d  each compose two gears (small and large gears) and are rotatably fitted onto the small stub-axles  30   a,    30   b,    30   c,    30   d,  respectively. Spur gears  31   f  and  31   g  are rotatably fitted on the small stub-axles  30   f  and  30   g,  respectively. A composite gear  31   e  composed of two gears (small and large gears) is positioned between and engaged with the two composite gears  31   d  and  31   f.  The composite gear  31   e  is formed integral with its small stub-axle  30   e  as can be seen in FIG.  3 . The composite gears  31   a,    31   b,    31   c,    31   d,    31   e,    31   f  and  31   g  together constitute a reduction gear train  31 . One end of the small stub-axle  30   e  of the composite gear  31   e  is rotatably fitted into an axle-hole  32  formed on the reduction-gear-train accommodating portion  20   c.  Upon one end of the small stub-axle  30   e  being properly fitted into the axle-hole  32 , the small stub-axle  30   e  extends substantially parallel to the optical axis O, similar to the other small stub-axles  30   a,    30   b,    30   c,    30   d,    30   f  and  30   g.  The zoom lens drive mechanism of the camera  10  is composed of the zooming motor  25  and the reduction gear train  31 . 
     In a state where all the gears of the reduction gear train  31  are arranged on the reduction-gear-train accommodating portion  20   c,  the worm gear of the composite gear  31   a  is engaged with the worm  28  of the zooming motor  25 . The small gear of the composite gear  31   a  is engaged with the large gear of the composite gear  31   b.  Likewise, the small gears of the composite gears  31   b,    31   c  and  31   d  are engaged with the large gears of the composite gears  31   c,    31   d  and  31   e,  respectively. The small gear of the composite gear  31   e  is engaged with the spur gear  31   f  while the spur gear  31   f  is engaged with the spur gear  31   g.    
     A supporting plate  33  is secured to the reduction-gear-train accommodating portion  20   c  to support the reduction gear train  31 . The supporting plate  33  is provided with a plurality of axle-holes  34  for supporting the corresponding ends of the small stub-axles  30   a  through  30   f.  The supporting plate  33  is further provided with two holes  35   a  and  35   b  while the reduction-gear-train accommodating portion  20   c  is provided with corresponding two holes  36   a  and  36   b.  The supporting plate  33  is secured to the reduction-gear-train accommodating portion  20   c  by screwing a set screw  37  into each of the holes  36   a  and  36   b  and through the corresponding holes  35   a  and  35   b,  respectively. 
     In the assembling process of the reduction gear train  31 , all the gears of the reduction gear train  31  are firstly arranged on the reduction-gear-train accommodating portion  20   c,  and subsequently the supporting plate  33  is placed on the reduction-gear-train accommodating portion  20   c  with all the free ends of the small stub-axles  30   a  through  30   f  being properly fitted in the respective axle-holes  34 . Thereafter a set screw  37  is screwed into each of the holes  36   a  and  36   b  and through the corresponding hole  35   a  or  35   b  of the supporting plate  33 . Consequently, all the gears of the reduction gear train  31  are firmly supported in the reduction-gear-train accommodating portion  20   c  between the reduction-gear-train accommodating portion  20   c  and the supporting plate  33 , without dropping out therefrom. 
     In a state where the reduction gear train  31  is assembled in the accommodating unit  20 , the reduction gear train  31  is positioned in a space between the zooming motor  25  and the zoom lens barrel  12  to be aligned substantially in the vertical direction of the camera body  11 , as can be seen from FIG.  1 . 
     The camera  10  is provided, between the zoom gear  12   a  and the spur gear  31   g  in the camera body  11 , with a pinion gear  38  which is rotationally fitted on a rotational axis  38   a  extending parallel to the optical axis O. The pinion gear  38  stays in mesh with the zoom gear  12   a.  The pinion gear  38  is engaged with the spur gear  31   g  when the accommodating unit  20  is properly set inside the camera body  11 . 
     Accordingly, rotation of the drive shaft  25   a  of the zooming motor  25  is transmitted to the reduction gear train  31  via the worm  28  and the worm wheel of the composite gear  31   a.  The transmitted rotation is reduced in speed by the reduction gear train  31  to be transmitted to the zoom gear  12   a  via the pinion gear  38 . Through such a zoom lens drive mechanism the zoom lens barrel  12  advances or retreats along the optical axis O in accordance with the rotational direction of the drive shaft  25   a  of the zooming motor  25  to thereby vary the focal length; i.e., perform zooming. 
     In the illustrated embodiment to which the present invention is applied, the camera  10  is successfully made small and compact by forming the battery chamber  20   a,  the zooming motor accommodating portion  20   b  and the reduction-gear-train accommodating portion  20   c  as one unit (i.e., the accommodating unit  20 ), which makes it possible to space-efficiently arrange the battery chamber  20   a,  and accommodating portions  20   b  and  20   c  within the camera body  11 , without consuming much internal space of the camera body  11 . In addition, the accommodating unit  20  can be secured to the camera body  11  therein after the reduction gear train  31 , the zooming motor  25  and other parts are all fixed onto the accommodating unit  20 , wherein the zoom lens drive mechanism and the battery chamber  20   a  can be assembled at one time, which facilitates assembly of the camera  10 . As can be seen from FIG. 2, space in the grip portion  13  is efficiently used by positioning the accommodating unit  20  in the grip portion  13 , which bulges forwardly from the camera body  11 . It should be noted that the zooming motor  25  can be secured to the accommodating unit  20  after the unit  20  is secured to the camera body  11 . 
     In a camera such as the illustrated embodiment of the camera  10  which has a camera body of an oblong box shape and a zoom lens barrel provided at the front center portion of the camera body, the film chamber and the spool chamber are generally located at respective ends (right and left ends) in the camera body with each axis of the film chamber and the spool chamber extending in the vertical direction of the camera. In order to arrange the accommodating unit  20  in the camera body  11  in a space-efficient manner, in the case where the accommodating unit  20  is to be positioned adjacent to the film chamber  15 , it is preferable to design the zooming motor accommodating portion  20   b  and the battery chamber  20   a  to have their axes extending substantially parallel to the axis of the film chamber  15 . Since the camera  10  is designed to have such a structure, the accommodating unit  20  is successfully positioned adjacent to the film chamber  15  without consuming much space within the camera body  11 . 
     Furthermore, since the accommodating unit  20  is formed such that the reduction gear train  31  is positioned in a space between the zoom motor  25  and the zoom lens barrel  12 , the space is utilized in a more space-efficient manner. In order to obtain a predetermined reduction speed ratio in such a limited space, the reduction gear train  31  is positioned to extend substantially in the vertical direction of the camera body  11 , similarly to the axes of the zooming motor  25  and cell  21 . This makes it possible to utilize the limited space in a space-efficient manner. 
     In the illustrated embodiment, the zooming motor  25  is positioned with its drive shaft  25   a  extending downwards wherein the rotation of the drive shaft  25   a  is transmitted from lower side (drive shaft  25   a ) to upper side (pinion gear  38 ) in the camera body  11 . However, the zooming motor  25  can be positioned with its drive shaft  25   a  extending upwards. In this case, the reduction gear train  31  is reversely arranged, while the pinion gear  38  is arranged at the lower side of the camera body  11  wherein the rotation of the drive shaft  25   a  is transmitted from upper side to lower side in the camera body  11 . 
     In the illustrated embodiment, all the gears of the reduction gear train  31  are supported by the accommodating unit  20 . However, some gears of the reduction gear trains  31  can be supported by another portion secured to the camera body  11 , as long as all the gears of the reduction gear train  31  are properly engaged after the accommodating unit  20  is secured to the camera body  11  therein. 
     Obvious changes may be made in the specific embodiment of the present invention described herein, such modifications being within the spirit and scope of the invention claimed. It is indicated that all matter contained herein is illustrative and does not limit the scope of the present invention.