Patent Publication Number: US-2006002699-A1

Title: Camera

Description:
BACKGROUND  
      The present invention relates to a camera with a focus adjustment mechanism.  
      In general, camera lens modules include an optical lens set, a shutter, a diaphragm, focus adjustment mechanism and focus mode switch. To reduce the size of the camera, corresponding element size must be reduced.  
       FIG. 1  is an exploded perspective view of a focus adjustment mechanism of a conventional camera. A lens  80  is supported by a lens holder  100 ′. A focus mode switch  40  and a focus element  60  are disposed between the lens holder  100 ′ and a base (a charge coupled device holder in a digital camera)  200 ′. The focus mode switch  40  switches the lens  80  between general focus mode and macro focus mode. The focus element  60  is normally used only during fabrication and assembly. Focus is adjusted by engaging adjusting teeth  61  on the periphery of the focus element  60  to rotate the focus element  60 . When focus is adjusted, the focus element  60  is fixed permanently.  
      In  FIG. 1 , the focus mode switch  40  and the focus element  60  overlap. Since the focus element  60  is not used after the camera leaves the factory, a compact structure is preferred. In conventional structure, however, the focus mode switch  40  and the focus element  60  occupy considerable space.  
     SUMMARY  
      A camera according to an embodiment of the invention comprises a lens holder, a base, a first adjusting element between the lens holder and the base contacting the lens holder, and a second adjusting element between the lens holder and the base contacting the base, wherein the first adjusting element is movably received in the second adjusting element to adjust distance between the lens holder and the base.  
      First and second adjusting elements are concentrically disposed with the first adjusting element rotatable with respect to the second adjusting element. The second adjusting element comprises a circular main body and a flange axially protruding therefrom to form a shoulder to receive the first adjusting element. The second adjusting element further comprises a plurality of teeth on the periphery of the flange for focus adjustment.  
      The flange is annular and includes a notch provided with a first edge and a second edge. The first adjusting element comprises a lever projecting from the periphery of the first adjusting element and through the notch is movable between the first and second edges when the first adjusting element is received in the second adjusting element.  
      The camera further comprises a guiding element connecting the lens holder and the base along which the lens holder moves toward or away from the base with the first adjusting element moving in the second adjusting element. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention can be more fully understood by reading the subsequent detailed description and examples with references made to the accompanying drawings, wherein:  
       FIG. 1  is a perspective view of a conventional digital camera;  
       FIG. 2   a  is an exploded perspective view of a camera of an embodiment of the invention;  
       FIG. 2   b  is a partially exploded perspective view of a camera of an embodiment of the invention;  
       FIG. 3  is a perspective view of a camera of an embodiment of the invention; and  
       FIG. 4  is an assembled side view of a camera of an embodiment of the invention showing a lens holder, a focus mode switch and a focus element. 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 2   a , a camera comprises a lens  80 , a lens holder  100  supporting the lens  80 , a base  200  carrying a charge coupled device, a focus mode switch (a second adjusting element)  400  contacting the lens holder  100 , and a focus element (a first adjusting element)  600  receiving the focus mode switch  400  and contacting the base  200 .  
      Referring to  FIGS. 2   a,    2   b  and  3 , a guide bar (guiding element)  20  connects the lens holder  100  and the base serving as a charge coupled device holder (in a digital camera)  200 . The lens holder  100  moves toward or away from the base  200  by rotation of the focus mode switch  400  and the focus element  600 . The focus mode switch  400  and the focus element  600  are disposed between the lens holder  100  and the base  200 . The focus element  600  includes an annular main body  601  and a flange  602  axially protruding from the main body  601 . The focusing switch  400  is also annular and received in the focus element  600  (disposed on the main body  601  and encircled by the flange  602 ). The concentric configuration renders the focus mode switch  400  rotatable within the focus element  600 .  
      In  FIG. 2   b,  the annular flange  602  is provided with a notch  608  having a first edge  605  and a second edge  606 . The focus mode switch  400  is provided with a finger  401  which extends through the notch  608 , movable between the first and second edges  605  and  606  when the focus mode switch  400  is received in the focus element  600 . The finger  401 , when pushed, rotates the focus mode switch  400 . A plurality of first portions  402  of various heights abuts a protrusion  101  on the lens holder  100 , as shown in  FIG. 4 . The lens holder  100  can move toward or away from the base  200  along the guide bar  20  by rotation of the focus mode switch  400 , thereby adjusting distance between the lens  80  and the charge coupled device (not shown).  
      The focus element  600  has adjusting teeth  603 , engagement of which provides adjustment of focus. The focus element  600  has a plurality of inclined second portions  604  abutting a protrusion  201  on the base  200 . The focus element  600 , when rotated, moves the lens holder  100  toward or away from the base  200  along the guide bar  20  to provide focus adjustment.  
      The concentric structure of the focus mode switch and the focus element of the embodiment occupies less space than in the conventional structure.  
      While the invention has been described by way of example and in terms of preferred embodiment, it is to be understood that the invention is not limited thereto. To the contrary, it is intended to cover various modifications and similar arrangements (as would be apparent to those skilled in the art). Therefore, the scope of the appended claims should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements.