Abstract:
A curved flat cable ( 32 ) for electrically connecting a cards cage ( 18 ) and a charged coupled device (CCD) ( 12 ) can be freely rotated coaxially in respect to the cards cage, and includes a curved shaped insulating film and a set of separate plated conductor strips ( 23, 44 ) disposed on the curved shaped insulating film.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to an electronic flat cable for connecting a fixed part and a rotating part which can be freely rotated coaxially in respect to the fixed part. 
       BACKGROUND OF THE INVENTION 
       [0002]    Flat cables are commonly used for connecting between electronic boards and electronics devices, which are often comprised of more than one electronic board or part. Flat cables are used to transmit electronic signals from one electronic part to another electronic part, wherein both parts are typically installed in an electronic device. 
         [0003]    A common example is a consumer radio where two electronic parts inside the radio are connected via a flat cable. In this example the electronic parts inside the radio are static. Another example is wherein two parts of a device are connected via a flat cable and one of the electronic parts is moveable with respect to the other electronic part. The flat cable connecting the moving part and the static part may be bent and consequently damaged due to the frequent mechanical strain applied on the cable during the movement of the moving part. 
         [0004]      FIGS. 1A and 1B  show a typical digital camera back  10  (DCB). The DCB  10  is comprised of two parts, an electronic cards cage  18  and a frame  13 , which includes a charged coupled device (CCD) element  12 . Cards cage  18  and CCD element  12  are electronically connected via conductor strips  23  disposed in a flat cable  22 , shown in  FIG. 2 . Flat cable  22  is inserted into cards connector  14  (in cards cage  18 ) on one end, and into CCD connecter slot  16  (in CCD element  12 ) on the other end. 
         [0005]    The CCD element  12  is movable with respect to the cards cage  18 , by rotating wheel  11 , in either direction, as indicated by arrow  15 . The CCD element  12  is designed to be in one of two image capture positions, landscape  24  or portrait  26 , as is illustrated in  FIG. 3 . CCD element  12  rotates 90 degrees with respect to cards cage  18  when changing positions from portrait to landscape and vice versa. 
         [0006]      FIG. 2  shows regular flat cable  22 , which connects CCD element  12  and cards cage  18 . When the CCD element  12  changes position from landscape  24  to a portrait  26  position, see  FIGS. 3B and 3C , the flat cable  22  bends or is deformed. The first edge  28  of the flat cable  22 , shown in  FIG. 2 , will get mechanically strained and the second edge  29  will bend. Slot  16  changes orientation when the CCD element  12  is rotated from image landscape position  24  to image portrait position  26 , as slot  16  rotates from a horizontal position in  FIG. 3B  to a vertical position in  FIG. 3C . Connector  42 , which is inserted in slot  16 , causes disposed conductor stips  23  to twist. 
         [0007]    Another problem is that flat cable  22 , when rotated by 90 degrees, must be long enough to compensate for cable bending during the rotation. A long cable will require an increase in the space needed for the enclosure to house CCD element  12  and cards cage  18 . 
         [0008]    It is readily apparent the flat cable  22  has several disadvantages when it is connected to a moving part. Reliability problems are caused by the mechanical strain applied to the cable when CCD element  12  rotates, and cable rotation over time may break the cable conductor strips. A long cable requires excessive electrical power needs for the DCB  10  and increases material cost. A long cable also imposes increased space for the DCB  10 , and thus enlarges the DCB  10  form factor. 
       SUMMARY OF THE INVENTION 
       [0009]    Briefly, according to one aspect of the present invention, a flat cable for electrically connecting a fixed body and a rotating body, which can freely rotate coaxially with respect to the fixed body, includes a curved shaped insulating film and a set of separate plated conductor strips disposed on the curved shaped insulating film. According to another aspect of the invention, a CCD on a digital camera is rotated to capture landscape and portrait photographs. 
         [0010]    These and other objects, features, and advantages of the present invention will become apparent to those skilled in the art upon a reading of the following detailed description when taken in conjunction with the drawings wherein there is shown and described an illustrative embodiment of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]      FIGS. 1A and 1B  illustrate a digital camera back; 
           [0012]      FIG. 2  illustrates a prior art flat cable; 
           [0013]      FIGS. 3A-3C  illustrate a landscape and a portrait position of the digital camera back; 
           [0014]      FIGS. 4A-4C  illustrate a curved shaped cable with connectors; 
           [0015]      FIG. 5  illustrates a sliding surface and a separating surface for protecting the cable from being damaged; and 
           [0016]      FIGS. 6A-6C  illustrate a curved shaped cable in landscape and portrait position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    A curved shaped flat cable  32  shown in  FIGS. 4A-4C  overcomes deficiencies of a standard flat cable  22 . The curved flat cable  32  is specifically designed for the digital camera back (DCB)  10 , but can be used in similar applications where two electronic parts are connected by a cable and at least one part moves in respect to the other part. 
         [0018]    The curved flat cable  32  is specifically designed to allow 90 degree rotation of a charged couple device (CCD) element  12  by using a relatively short, curved shaped cable. The design overcomes disadvantages created by using a regular flat cable  22  as described in the background section. Curved flat cable  32  reduces the back pulling effect of the flat cable after CCD element  12  is rotated by 90 degrees, thus diffusing mechanical forces created on curved flat cable  32 . 
         [0019]    The curved flat cable  32  was designed by imitating the radial movement of the CCD element  12  and by closely studying the path created by a regular flat cable  22  connecting between CCD element  12  and cards cage  18 . The created path is a curved shaped path as is illustrated in  FIG. 4A  showing the natural path  30  for the cable. The circumferential length of far end part  36 , see  FIG. 4B , is larger than circumferential length of the near end part  38  of curved flat cable  32 .  FIG. 4B  shows a two dimensional schematic view of curved flat cable  32  configured with connectors  42  and  43  in each end of the cable, with a curved shaped disposed conductor strips  44 .  FIG. 4C  shows a partial three dimensional view of cable  32  when it is bended inside the DCB, wherein cable bend  34  illustrates the bent cable. 
         [0020]      FIG. 5  shows a sliding surface  52 . The sliding surface  52  is physically attached to cards cage  18 . Separating surface  56  is physically attached to frame  13 , which houses CCD element  12 , and rotates together with CCD element  12 . 
         [0021]    Curved flat cable  32  is positioned between rotating separating surface  56  and sliding surface  52 . This configuration protects the curved flat cable  32  from touching electronic parts which are residing on the CCD element  12  or on the cards cage  18 , thus preventing curved flat cable  32  from getting damaged. Curved flat cable  32  is inserted through cable opening  54  and connected to connector  14  in cards cage  18 . The other end of curved flat cable  32  is inserted through opening  58  and connected to connector  16  in CCD element  12 . Cable opening  58  is designed to conform with the rotation shape of curved flat cable  32  when CCD element  12  changes positions from portrait to landscape and vice versa.  FIGS. 6A and 6B  show the shape of cable  32  when the CCD element  12  is in the arc shaped flat cable landscape position  62  and  FIG. 6C  shows curved flat cable in the arc shaped flat cable portrait position  64 . 
         [0022]    The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the scope of the invention. 
       PARTS LIST 
       [0000]    
       
           10  digital camera back (DCB) 
           11  wheel 
           12  charged coupled device (CCD) 
           13  frame 
           14  connector cards cage 
           15  arrow 
           16  slot 
           18  cards cage (static) 
           22  flat cable 
           23  disposed conductor strips 
           24  image landscape position 
           26  image portrait position 
           28  first edge of regular flat cable 
           29  second edge of regular flat cable 
           30  cable natural path created by 90 degree rotation 
           32  curved flat cable 
           34  cable bend 
           36  far end of curved cable 
           38  near end of curved cable 
           42  connector 
           43  connector 
           44  arc shaped disposed conductor strips 
           52  sliding surface 
           54  cable opening 
           56  separating surface 
           58  cable opening (attached to CCD element) 
           62  arc shaped flat cable landscape position 
           64  arc shaped flat cable portrait position