Patent Publication Number: US-2006018648-A1

Title: Image capturing device

Description:
BACKGROUND  
      The present invention relates in general to an image capturing device and in particular to an image capturing device with mutually rotating lens and viewfinder.  
      A photo image captured through a lens of a traditional single lens reflex camera (SLR) is the same as the viewed image via the viewfinder thereof. With respect to a twin lens reflex camera (TLR), however, the photo image captured through the lens is different from that viewed through the viewfinder. The aberration can increase with variations in the focal length from a long distance to a short distance.  
     SUMMARY  
      Accordingly, an embodiment of the invention provides an image capturing device. Light enters a viewfinder along a first central axis thereof. Light enters a lens along a second central axis thereof. An adjusting member connects the lens and the viewfinder, rotating around the second central axis thereby defining a focal length of the lens. The first and second axes cut across each other at an intersection when the adjusting member impels the viewfinder to rotate, wherein the focal length is substantially equal to the distance from the lens to the intersection.  
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
      The present invention will be more fully understood from the following detailed description and the accompanying drawings, given by way of illustration only and thus not intended to be limited thereto.  
       FIG. 1  is a perspective diagram of an image capturing device in accordance with an embodiment of the invention;  
       FIGS. 2   a ,  2   b  and  2   c  are perspective diagrams of the image capturing device in distance mode; and  
       FIGS. 3   a ,  3   b  and  3   c  are perspective diagrams of the image capturing device in macro mode; 
    
    
     DETAILED DESCRIPTION  
      Referring to  FIG. 1 , the image capturing device is a twin lens reflex camera (TLR), comprising a stopper  1 , a resilient member  2 , a viewfinder  4 , a first hinge  5 , a second hinge  3 , an abutting member  6 , a third hinge  7 , a lens  8  and an adjusting member  9 . The stopper  1  is substantially parallel to the lens  8 , comprising a protruding stop portion  11  for abutting the viewfinder  4 . The resilient member  2  is a torsion spring between the stopper  1  and the viewfinder  4 . As shown in  FIG. 1 , the second hinge  3  passes through the resilient member  2 , wherein the resilient member  2  is rotatable around the second hinge  3  and exerts spring force on the viewfinder  4 .  
      As shown in  FIG. 1 , a XYZ coordinate is defined. The viewfinder  4  is rotatable around the first hinge  5 , wherein the first hinge  5  is disposed through the viewfinder  4  and parallel to the X axis. Light enters the viewfinder  4  along a first central axis Y 1  thereof, and light enters the lens  8  along a second central axis Y 2  thereof parallel to the Y axis and the first central axis Y 1 . The adjusting member  9  is fixed to a protruding connection portion  81 , such that the adjusting member  9  makes the lens  8  to rotate around the second central axis Y 2 , thereby adjusting the focal length of the lens  8 .  
      In  FIG. 1 , the abutting member  6  contacts the viewfinder  4  and the adjusting member  9 , wherein the third hinge  7  is disposed through an end of the abutting member  6  and parallel to the Y axis. Particularly, the adjusting member  9  has a protruding contact portion  91  for sliding with respect to the bottom surface of the abutting member  6 , and the abutting member  6  has two protrusions  61  movably contacting the bottom surface of viewfinder  4 .  
      Referring to  FIGS. 2   a ,  2   b  and  2   c , the viewfinder  4  posture is adjustable between a “distance mode” as shown in  FIGS. 2   a - 2   c  for long shooting distance, and a “macro mode” as shown in  FIGS. 3   a - 3   c  for short shooting distance. In  FIG. 2   c , the viewfinder  4  is parallel to the lens  8  for long shooting distance, wherein the first and second central axes Y 1  and Y 2  are substantially parallel to each other such that the viewing image via the viewfinder  4  can approximate the photo image through the lens  8 .  
      To shift from distance mode to macro mode for capturing an image of a near object, the adjusting member  9  can be rotated to refine the focal length and adjust the posture of the viewfinder  4  simultaneously. As shown in  FIGS. 3   a ,  3   b  and  3   c , to shift from distance mode to macro mode, the adjusting member  9  impels the lens  8  to rotate around the second central axis Y 2  in a second direction A 2 . Since the resilient member  2  is compressed, it exerts spring force on the viewfinder  4  thereby rotating around the first hinge  5  and impelling the abutting member  6  rotating by an angle a as shown in  FIG. 3   b.    
      When the adjusting member  9  rotates in the second direction A 2 , the abutting member  6  rotates around the third hinge  7 , and the contact portion  91  slides with respect to the bottom surface of the abutting member  6 , such that the viewfinder  4  and the lens  8  form an included angle b as shown in  FIG. 3   c . When the abutting member  6  rotates by angle a, as shown in  FIGS. 3   b  and  3   c , the first central axis Y 1  rotates by angle b to position Y 1 ′ such that the first and second central axes Y 1  and Y 2  cross at an intersection P and form an included angle b, wherein the distance from the lens to the intersection P is L. Specifically, the adjusting member  9  can impel the lens  8  and the viewfinder  4  to rotate simultaneously, thus adjusting the focal length with the distance L from the lens  8  to the intersection P being equal thereto.  
      On the contrary, to shift from distance mode to macro mode for capturing an image of a far object, the adjusting member  9  can be rotated in the first direction A 1  opposite to the second direction A 2  as shown in  FIG. 2   b , thereby defining a longer focal length. As the arrows indicate in  FIG. 2   b , the adjusting member  9  impels the abutting member  6  to rotate counterclockwise around the third hinge  7 , and the abutting member  6  further impels the viewfinder  4  to rotate around the first hinge  5 , such that the first and second axes Y 1  and Y 2  are substantially parallel to each other as shown in  FIG. 2   c . At this moment, the resilient member  2  is compressed, and the viewfinder  4  is stopped by the stop portion  11  of the stopper  1 , whereby the viewfinder  4  and the lens  8  become substantially parallel. As the first and second axes Y 1  and Y 2  are substantially parallel to each other, the viewed image via the viewfinder  4  approximates the photo image through the lens  8  for capturing an image of a far object.  
      As both focal length and the viewfinder  4  posture angle are adjusted simultaneously by rotating the adjusting member  9 , the image received through the viewfinder  4  and the lens  8  can be more approximate irrespective of near or far targets. As shown in  FIGS. 3   b  and  3   c , the included angle b of the first and second axes Y 1  and Y 2  vary along with the rotation angle a of the abutting member  6 . When the included angle b increases, the distance L from the lens to the intersection P decreases, thus facilitating capture of an image of a near object. On the contrary, the included angle b decreases when rotating the adjusting member  9  around the second central axis Y 2  in the first direction A 1 . Thus, the abutting member  6  impels the viewfinder  4  to rotate such that the distance L from the lens  8  to the intersection P decreases, thereby facilitating capture of an image of a far object. However, in some embodiments, the adjusting member  9  can also be L-shaped, movably connecting the viewfinder  4  and the lens  8  without the abutting member  6 , capable of adjusting the focal length and the viewfinder  4  posture and shifting between the distance mode and the macro mode.  
      While the invention has been described by way of example and in terms of the 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 to encompass all such modifications and similar arrangements.