Abstract:
An image-taking apparatus includes an image-taking system for obtaining an image of a subject, the image-taking system including a lens and an image pickup device, a battery loading part, into which a battery is loaded, the battery loading part being arranged in a place not to overlap said image-taking system in a direction of a thickness of said image-taking apparatus, a first substrate having a digital circuit, and a second substrate having an analog circuit, wherein the first and second substrates are arranged at both sides of the battery loading part in said direction of a thickness.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an image-taking apparatus that includes both analog and digital circuits. 
     Along with the recent improved functions of the image-taking apparatuses and associated speeding up of the digital interfaces for connections with external apparatuses, some problems have arisen, such as unnecessary noises emitted to the air and disturbed images due to the interference between analog and digital circuits in the image-taking apparatus, particularly on an analog output of an image display apparatus, such as a TV, in the image-taking apparatus. 
     For reduced noises and excellent images, the potential differences among grounds of all the circuits should be strictly reduced. For this purpose, a battery armature connected to a battery that makes a reference potential of the image-taking apparatus and both the analog and digital circuits should be arranged close to one another. 
     On the other hand, the miniaturization of the image-taking apparatus restricts the arrangement freedom of connectors for the digital and analog outputs and the battery. 
     Prior art disclose, as in Japanese Patent Application, Publication No. 2002-072321, a circuit board that has a digital-output (USB) connector and an analog-output (VIDEO) connector arranged on a single substrate, rather than two separate boards, such as an analog board and a digital board. The conventional configuration may possibly cause noises and malfunctions resulting from the electromagnetic waves generated from the electric circuits. 
     BRIEF SUMMARY OF THE INVENTION 
     It is an exemplary object of the present invention to provide a small image-taking apparatus with few noises and interferences among circuits. 
     An image-taking apparatus according to one aspect of the present invention includes an image-taking system for obtaining an image of a subject, the image-taking system including a lens and an image pickup device, a battery loading part, into which a battery is loaded, the battery loading part being arranged in a place not to overlap said image-taking system in a direction of a thickness of said image-taking apparatus, a first substrate having a digital circuit, and a second substrate having an analog circuit, wherein the first and second substrates are arranged at both sides of the battery loading part in said direction of a thickness 
     An image-taking apparatus according to another aspect of the present invention includes an image-taking system for obtaining an image of a subject, the image-taking system including a lens and an image pickup device, a battery loading part, into which a battery is loaded, the battery loading part being arranged in a place not to overlap said image-taking system in a direction of a thickness of said image-taking apparatus, a connector for external connections; and a contact member in contact with an electrode of the battery loaded in the battery loading part, wherein the battery loading part includes a spring for forcing the battery in an ejecting direction, the spring being arranged between the connector and the contact member along the first direction. 
     Other objects and further features of the present invention will become readily apparent from the following description of the preferred embodiments with reference to accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a camera according to one embodiment of the present invention. 
         FIG. 2  is an exploded perspective view of a camera according to this embodiment. 
         FIG. 3  is a view around a battery case according to this embodiment, from which an analog board is detached. 
         FIG. 4  is a view showing of a component arrangement above the battery. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the accompanying drawings, a description will be given of a preferred embodiment of the present invention. 
       FIG. 1  is an exploded perspective view of a digital camera as an image-taking apparatus and electronic apparatus according to one embodiment of the present invention.  FIG. 2  is another exploded perspective view. In the following description, a side of the camera on which a lens barrel is provided is referred to as a front, and a side on which a liquid crystal panel is provided is referred to as a back. In addition, a lateral direction is defined as a direction orthogonal to the image-taking optical axis, with which the lens barrel and the battery case are aligned. 
     In these figures,  1  is a front cover that covers the front surface of the camera.  2  is a rear cover that covers its rear surface. The front cover  1  and the rear cover  2  constitute a camera exterior. The digital camera is incorporated with an image-pickup device  60 , such as a CCD sensor and a CMOS sensor (although  FIG. 2  shows a back surface of the image-pickup device  60 ), and a subject image formed by the image-pickup device  60  is converted into an electric signal and output as an image signal. The lens barrel  3  and the image-pickup device  60  structure an image-taking system. 
       3  denotes a lens barrel that holds an image-taking lens, etc. The lens barrel  3  is incorporated with a finder unit, a zoom motor  5  and a gear unit  6 . The lens barrel  3  is fixed onto a chassis  8  by fixing screws  7   a ,  7   b  and  7   c . Formed in the front cover  1  are an opening  1   a  that exposes the lens barrel  3 , an opening  1   b  that exposes an illumination unit, which will be described later, a photometric window, and a viewfinder window. 
       9  denotes a battery case as a battery loading part into which a battery  51  is detachably loaded, and the battery loading part  9  is fixed onto the chassis  8  by screws  11   a  and  11   b .  10  denotes an analog (or second) substrate that is mounted with an analog electronic component, and incorporated between the battery case  9  and the chassis  8 . 
     The analog substrate  10  is further mounted with a D/A converter that converts an image signal from an image processing LSI into an analog signal, a buffer circuit that increases a driving force of an analog signal from the D/A converter, and the like. 
     As shown in  FIGS. 3 and 4 , a rectangular opening  9   a  is provided in the front bottom of the battery case  9 , and covered with the analog substrate  10  that is incorporated between the battery case  9  and the chassis  8 . A holding part  9   b  that holds a battery armature  56  and an ejection spring  58 , which will be described later, and a surface  9   a  below the top surface of the holding part  9   b  are formed at the top of the battery case  9  or at its end in the battery loading direction. 
       51  denotes a battery that serves as a power supply for the digital camera, and is loaded into the battery case  9 . 
     The ejection spring  58  that contacts almost the center of the top surface of the loaded battery  51  is provided in the battery case  9 . According to the above structure, in loading the battery  51  into the battery case  9 , the ejection spring  58  is compressed by the battery  51 . When a battery unlock button (not shown) is pressed while the battery  51  is being loaded into the battery case  9 , the spring force of the compressed ejection spring  58  ejects the battery  51  from the battery case  9 . 
     The battery armature  56  that contacts the electrode of the battery  51  and an analog output (or second) connector  57  that outputs analog signals, such as images and voices, are mounted onto the front surface of the analog substrate  10  on the battery case  9  side, and are engaged with concaves  10   b  and  10   c  in the battery case  9 . 
     An insulating sheet (not shown) is adhered to a surface of the analog substrate  10  on the battery case side  9 , and protects a through-hole in the substrate, etc. The insulating sheet has an approximately triangular hole. 
     The position of the hole accords with an insertion direction instruction mark (not shown) on the battery  51  in the lateral direction. The insertion of the battery  51  into the battery case  9  becomes easier with an alignment between the hole position and the mark position. The visibility of the hole improves through silk printing on the analog substrate at the hole position provided on the insulating sheet. 
     In  FIGS. 1 and 2 ,  12  is an illumination unit having a light emitting part  13  at its top. An illumination optical system flexible printed board  14  mounted with an illumination drive circuit is adhered to a frame part that extends under the camera, and an illumination condenser  15  is fixed onto the frame part. 
     The illumination unit  12  is arranged in front of the gear unit  6  and zoom motor  5  incorporated into the lens barrel  3 , and fixed onto the chassis  8  via a screw  16  from its side surface. The light emitting part  13  in the camera lateral direction is approximately as large as a combination of the gear unit  6  and the zoom motor  5  in the camera lateral direction, thereby maximizing a space behind the irradiation optical-axis direction of the light emitting part  13 . The gear unit  6  and the zoom motor  5  are arranged at the back in the optical-axis direction. 
       17  denotes a digital (or first) substrate mounted with digital electronic components, such as a CPU, a memory and an image processing LSI. The digital substrate  17  faces the analog or second substrate  10 . A slot  17   a  of a semiconductor memory card  17   b  as an external memory and a USB (or first) connector  17   c  that outputs a digital signal are mounted on the rear surface side of the digital substrate  17 . The USB connector  17   c  and the analog connector  57  are arranged parallel to a direction in which the digital substrate  17  opposes to the analog substrate  10 . The USB connector  17   c  and the analog connector  57  are arranged along a surface  9   a  under the top surface of the battery case  9 . Thereby, the top surfaces of both the connectors  17   c  and  57  are approximately level with that of the holding part  9   b  of the battery case  9 . The digital substrate  17  is fixed onto the battery case  9  and the chassis  8  by the screws  18   a  to  18   c.    
       19  denotes an operational flexible printed board mounted with an operational members, such as a release switch  19   a , and a power switch  19   b .  20  denotes a speaker. The terminal of the speaker  20  is soldered to one end of the operational flexible printed board  19 .  21  denotes an operational button base member made of silicon rubber. A cross button  22  and a center button  23 , and push buttons  24  and  25  are attached to the rear surface of the operational button base member. The rear cover  2  has an opening  2   a  that exposes these buttons from the camera rear surface. 
     Metal domes  22   a  to  25   a  corresponding to the above operational buttons  22  to  25  are adhered to the front surface of the operational button base member  21 . When each operation button is pressed, the corresponding metal dome contacts a conductive pattern formed on the operational flexible printed board  19 , and the conductive pattern is electrified. 
       21   a  denotes a ring-shaped buffer member that is formed on the operational button base member  21 , and adapted to enclose the outer peripheral of the speaker  20 . The buffer member  21   a  clogs an aperture between the speaker  20  and the rear cover  2 . The number of components and cost can be reduced, because the conventional buffer member can be omitted, such as urethane foam, which serves to prevent sound leakage etc. and is adhered to the top of the speaker. 
       26  denotes a light-emitting button. An operational member  26   a  is provided at the center of the light-emitting button  26 , and exposes from the camera rear surface through the opening  2   a  in the rear cover  2 . A convex light guide member  27  is adhered to the back of the operational part  26   a . A tact switch W 10   a  is mounted on the analog substrate  10  in front of the guide member  27 . The tact switch  10   a  is configured to switch when the light guide member  27  is pressed toward the front of the camera. 
     An LED  10   b  is provided near the tact switch  10   a  in a direction orthogonal to the optical axis. The light emitted from the LED  10   b  is configured to enter the surface of the light-emitting button  26  via the light guide member  27 . A base part of the light-emitting button  26  is fixed onto the chassis  8  via a screw  28 . 
       29  denotes an LCD panel, which is held with a backlight (not shown) by an LCD holder  30 . The LCD holder  30  is fixed onto the chassis  8  by a screw  31 . The rear cover  2  has a rectangular opening  2   b  that exposes a display surface of the LCD panel  29 . 
       32  denotes a switch button that is provided at the top of the rear cover  2 , and switches the camera&#39;s operational mode. When the switch button  32  is slid in the lateral direction of the camera, the operational mode is switched among a still picture taking mode, a motion picture taking mode, and an image reproducing mode. 
       33  denotes a fixture plate arranged opposite to the switch button  32  (inside the camera) with respect to the rear cover  2 , and slidable with the switch button  32  in the lateral direction. An opening  33   a  in the fixture plate  33  holds a movable part of a mode switch (not shown) mounted on the operational flexible printed board  19 . When the switch button  32  is operated laterally, the mode switch switches the operational mode. 
       34  denotes a button holder that holds a release button  36  and a power button  37 , and constitutes the exterior that covers the top of the battery case  9 . A connector cover  38  is provided at one end of the button holder  34 , and extends downwardly in the camera. The connector cover  38  covers the USB connector  17   c  provided on the digital substrate  17 , and an image/voice connector  57  that is provided on the analog substrate  19  and adjacent to the USB connector  17   c  in the longitudinal direction of the camera. 
       41  denotes a strap attachment member used to attach the strap  42 . The strap attachment member  41  is molded by die casting for strength and design purposes. The strap attachment member  41  covers the side surface of the camera, and forms long holes  41   a  and  41   b  almost the center in the longitudinal direction. The strap  42  is put on a hanger  41   c  between the long holes  41   a  and  41   b.    
       43  denotes a semispherical concave inner member opposing to the inner surface of the strap attachment member  41 . The inner member  43  is engaged with the long holes  41   a  and  41   b  from the inside of the strap attachment member  41 . 
     In inserting the strap  42  into the long hole  41   a  from the outside of the camera, the tip of the strap  42  slides on the concave surface of the inner member  43  and drawn to the outside the camera from the long hole  41   b  for the easy attachment of the strap  42 . 
     The inner member  43  covers the edges of the long holes  41   a  and  41   b , and prevents the strap string  42  from contacting these edges and being severed. 
     The side cover  41  is fixed onto the chassis  8  when the front cover  1 , the rear cover  2  and the inner member  43  are held between the screws  44   a  and  44   b .  45  denotes a tripod attachment seat having a screw hole used to attach a tripod. 
     When the screws  46   a  and  46   b  are engaged with the side surfaces and the screws  47   a  and  47   b  are engaged with the bottom surfaces while the front cover  1  is engaged with the rear cover  2 . Thereby, the front cover  1  and the rear cover  2  are fixed together. 
     As described above, this embodiment arranges the analog substrate  10  and the digital substrate  17  opposite to each other via the battery  51 , and provides the USB connector  17   c  for digital signals on the digital substrate  17  and the connector  57  for analog signals on the analog substrate  10 . These connectors  17   c  and  57  oppose to each other in the longitudinal direction, and are provided above the battery  51 . 
     In other words, the USB connector  17   c  and the analog connector  57  are arranged between the analog substrate  10  and the digital substrate  17  which oppose to each other. This configuration can maximize the space above the battery  51 , and miniaturize the camera. 
     This embodiment arranges the top of the ejection spring  58  used to eject the battery  51  is arranged in the space among the USB connector  17   c , the analog connector  57 , and the battery armature  56 , and maximizes the space. This embodiment arranges the ejection spring  58  in the lateral direction among the USB connector  17   c , the analog connector  57 , and the battery armature  56 , and maximizes the space above the battery case  9  and provides a smaller size of the camera. 
     In addition, this embodiment arranges the battery  51  that has an electromagnetic shielding effect, between the analog substrate  10  and the digital substrate  17 , preventing the interferences between circuits, blocking the electromagnetic waves, and enabling the battery armature  57 , the analog substrate  10  and the digital circuit  17  to be arranged close to one another. The potential of each circuit approaches to the reference voltage of the battery  51 , reducing the potential differences among circuits and the resultant noises. 
     Moreover, the battery armature  56  provided on the analog substrate improves the functions of the analog circuit that is subject to the potential difference. 
     While the above embodiment describes the camera as an example, the present invention is applicable to other electronic apparatuses, e.g., an image display apparatus (such as a projector), and an imaging apparatus (such as a copier). 
     This application claims a foreign priority based on Japanese Patent Application No. 2004-270697, filed Sep. 17, 2004, which is hereby incorporated by reference herein.