Abstract:
A lens cover apparatus for camera includes a housing, a cover, and a slider. The cover is rotatably mounted to the housing to open/close a lens window for selectively exposing/shielding a lens of the camera. The slider is manually movable with respect to the housing to induce a horizontal movement of a first linkage, which is converted into a rotary motion of the cover by a second linkage that has a lever forming a slot movably receiving and guiding a peg extending from the cover.

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a sliding type lens cover apparatus for camera, and more particularly, to a lever-driven sliding type lens cover apparatus for camera. 
   2. Description of the Related Arts 
   In photography, the quality of an image is generally dependent on the film in the conventional camera or the CCD in the digital camera, and the lens. However, physical damages, such as flaws and scars, caused by undesired or accidental contact of the lens by a rigid object, and contaminations caused by dirt, grease, and fingerprints, often make problems in the maintenance of the lens, which seriously affects the quality of the image. It is thus very important to protect the lens in doing maintenance of the camera. In practice, lens covers are often adopted to protect the lens. 
   The conventional lens covers can be divided into two types: clipping type covers and mechanical type covers. 
   The clipping type cover is a disc-like device, and usually has a pair of clips to releasably engage with the lens barrels to fix the cover in front of the lens. Most of the clipping type covers are separate parts, independent of the cameras, and are usually tied to the cameras with strings to avoid being lost. These covers are very common in the conventional cameras, but not used so often in the digital camera industry. 
   The mechanical type covers can be divided into motor-driven type covers and hand-driven type covers. Both types employ mechanics to selectively open/close the cover and thus exposing/shielding the lens. U.S. Pat. No. 5,913,089 (the &#39;089 patent) and U.S. Pat. No. 6,254,289 (the &#39;289 patent) respectively describe a lens barrel cover of this type. The two similar inventions are both based on the same theory, which enables an element with short moment arm (such as the barrier driving lever in the &#39;089 patent and the power gear in the &#39;289 patent) to drive another element with long moment arm (such as the main-barrier cover and the sub-barrier cover in the &#39;289 patent and the lens cover in the &#39;089 patent). However, according to the lever principle, in order to work an element with long moment arm, the element with short moment arm needs a large force. Thus, such conventional designs bring in difficulty in operation. 
   Hence, an improved lens cover apparatus for camera is required to overcome the disadvantages of the prior art. 
   SUMMARY OF THE INVENTION 
   An object of the present invention is to provide a lens cover apparatus for camera, which opens/closes a lens cover with a minor movement and a small force. 
   A lens cover apparatus for camera in accordance with the present invention comprises a housing, a cover, and a slider. The cover is rotatably mounted in the housing to open/close a lens windows to selectively expose/shield a lens of the camera. The slider is manually movable with respect to the housing to induce a horizontal movement of a first linkage, which is converted into rotary motion of the cover by a second linkage that has lever forming a slot movably receiving and guiding a peg extending from the cover. 
   The present invention enables easy operation of the cover, simplifies the process, and mostly saves the force of the operation of the cover. In addition, the present invention adopts a multi-linkage design of single freedom, which ensures a steady and reliable system. 
   Other objects, advantages, and novel features of the invention will become more apparent from the following detailed description of a preferred embodiment when taken in conjunction with the accompanying drawings, wherein: 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a plan view of a lens cover apparatus for camera in accordance with the present invention; 
       FIG. 2  is an exploded view of the lens cover apparatus in  FIG. 1 ; 
       FIG. 3   a  is a pictorial view of the lens cover apparatus showing the cover in a closed position; 
       FIG. 3   b  is a pictorial view showing a back view of  FIG. 3   a;    
       FIG. 4   a  is a pictorial view of the lens cover apparatus showing the cover is an open position; 
       FIG. 4   b  is a pictorial view showing a back view of  FIG. 4   a ; and 
       FIG. 5  is a pictorial view showing the operation of the lens cover apparatus. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   With reference to the drawings and particular to  FIGS. 1 and 2 , a lens cover apparatus for camera in accordance with the present invention comprises a housing  2 , a slider  1  movably arranged with the housing  2 , a cover  3  for shielding/exposing a lens of a camera (both not shown), a fixing plate  4  fixed in the housing  2 , an L-shaped lever  6  fixed to the slider  1  and movably arranged in the housing  2 , a horizontal lever  5 , a vertical lever  7 , a plurality of screws  9 ,  10 ,  18 ,  19 , a plurality of rivets  11 ,  12 ,  13 ,  14 ,  15 ,  16 ,  17 , and a spring  8 . 
   The slider  1  has a small flat rectangular case-like shape, and is formed with a pair of posts  101  perpendicularly extending from a back surface thereof. Each post  101  defines an inner thread in a concave hole, serving as a screw hole, to engage the screw  18 ,  19  thereby fixing to the L-shaped lever  6 . 
   The housing  2  is substantially a flat rectangular hollow case having an open side. The housing  2  forms a circular lens window  21  for the lens of the camera, a flash window  22  for a flash (not shown) of the camera, a pair of slits  23 ,  24 , and an opening (not labeled) for the extension of the posts  101  of the slider  1 . The housing  2  has a left wall and a right wall, which respectively define first and second. screw holes  25 ,  26  near a top portion and a bottom portion to fix the fixing plate  4  inside the housing  2 . 
   The cover  3  is arranged inside the housing  2  to close/open the lens window  21 . The cover  3  comprises a main plate portion  31  of a circular shape and a connecting portion  32  smoothly extending from an external circumference of the main plate portion  31 . The main plate portion  31  is of a size substantially corresponding to and selectively and completely covering the lens windows  21 . The connecting portion  32  has a peg  321  perpendicularly extending from the connecting portion  32 , and a first fixing hole  322  formed in the connecting portion  32  at a location on an imaginary line connecting the peg  321  and a center of the circle of the main plate portion  31 . 
   The fixing plate  4  comprises a ring portion and a Z-shaped portion. The ring portion forms a lens hole  41 , corresponding in position to the lens windows  21 , for exposing the lens, a second fixing hole  42  corresponding to the first fixing hole  322 , and a first arc groove  43  centered at the second fixing hole  42  and corresponding to and receiving therein the peg  321 . An upper horizontal section of the Z-shaped portion has second coupling holes  44 . A lower horizontal section of the Z-shaped portion has a third fixing hole  45 , and a second arc groove  46  centered at the third fixing hole  45 . The fixing plate  4  also defines third and fourth screw holes  47  and  48  corresponding to and fixed with the first and second screw holes  25  and  26  of the housing  2  by the screws  9  and  10 . 
   The horizontal lever  5  is composed of a vertical portion and a horizontal portion. The vertical portion defines a third groove  51 , which extends vertically and receivingly engages with the peg  321 . The horizontal portion defines a horizontal groove  52  corresponding to the second coupling hole  44 , and a third coupling hole  53  at a free end thereof. 
   The L-shaped lever  6  comprises a vertical branch  61  and a horizontal branch  62 . The vertical branch  61  and the horizontal branch  62  each have a free end bent in the same direction to form a coupling end  610 ,  620 . A middle portion of the vertical branch  61  is laterally offset in the same direction as the coupling ends  610  and  620  thereby forming a protruded section (not labeled). Third and fourth screw holes  611 ,  612  are respectively defined on opposite sides of the protruded portion and corresponding to the posts  101 . The horizontal branch  62  also forms a first coupling hole  621 , and a tip  622  adjacent to the first hole  621 . 
   The vertical lever  7  defines a fourth groove  71  at an upper portion, and fourth and fifth coupling holes  72 ,  73  at a lower portion. The fourth groove  71  couples with the third coupling hole  53  with the rivet  14 , so that the vertical lever  7  links with vertical lever  5 . 
   The spring  8  is a torsion spring, having two free arms each having a bent end to fix to other elements. 
   In assembly, the coupling ends  610 ,  620  of the L-shaped lever  6  respectively couple with the slits  23  and  24  to retain the L-shaped lever  6  in the housing  2 . The protruded section of the L-shaped lever  6  protrudes beyond the opening of the housing  2 , through which the posts  101  of the slider  1  extend, and comes into contact with the back surface the slider  1  in between the posts  101 . The screws  18 ,  19  respectively joint the third and fourth coupling holes  611 ,  612  to the posts  101  thereby fixing the slider  1  to the L-shaped lever  6 . The cover  3  lies on the inside surface of the housing  2 , with the main body of the cover  3  covering the lens windows  21 , and the peg  321  projecting backward. The fixing plate  4  is positioned on the cover  3  and the L-shaped lever  6 . The rivet  11  extends through the second fixing hole  42  and the first fixing hole  322  to joint the cover  3  to the fixing plate  4  with the peg  321  movably received in the first groove  43 . In this way, the cover  3  is rotatable about the rivet  11  extending through the first or second fixing hole  322 ,  42 , which in turn selectively opens and closes the lens windows  21 . The fixing plate  4  is then fixed to the housing  2  by the screws  9 ,  10  that joint the third and fourth screw holes  47 ,  48  of the fixing plate  4  to the first and fourth screw holes  25 ,  26  of the housing  2 . The horizontal lever  5  lies on the fixing plate  4 . The rivets  12 ,  13  joint the second coupling holes  44  of the fixing plate  4  to the horizontal grooves  52  of the horizontal lever  5 . The third groove  51  receives the end of the peg  321 . Thus, the horizontal lever  5  is horizontally movable under guidance by the rivets  12 ,  13  fixed to the second coupling holes  44 , which exerts a horizontal force on the peg  321  to rotate the cover  3  about the rivet  11 . The vertical lever  7  lies on the horizontal lever  5  with the rivets  14 ,  15 ,  16  respectively jointing the third coupling hole  53 , the third fixing hole  45 , and the second groove  46  to the fourth groove  71 , the fourth coupling hole  72 , and the fifth coupling hole  73 . The rivet  17  joints with the first coupling hole  621 . The spring  8  lies between the fixing plate  4  and the L-shaped lever  6 , and is fixed by the tip  622  from shaking or breaking off. One arm of the spring  8  is fixed with the rivet  17 , and the other is fixed with the rivet  16 . 
   Referring to  FIGS. 3   a ,  3   b ,  4   a ,  4   b , and  5 , to operate, a user pushes the slider  1  to open the cover  3 . Taking  FIG. 5  as an example to describe the operation, when the user pushes the slider  1 , the L-shaped lever  6  moves leftward with the slider  1  due to the fact that the L-shaped lever  6  is fixed to the slider  1  by the screws  18 ,  19 . The spring  8  is then distorted, because one arm of the spring  8  is fixed to the rivet  17  that is fixed on the L-shaped lever  6 . This applies, via the other arm of the spring  8  that is fixed with the rivet  16 , a rightward force to the vertical lever  7 , causing the vertical lever  7  to swing clockwise. The rivet  14  coupling the fourth grooves  71  of the vertical lever  7  to the horizontal lever  5  induces a horizontal force on the horizontal lever  5 , causing the horizontal lever  5  to move, under the guidance of the rivets  12 ,  13  received in the horizontal groove  52 , in the horizontal direction and thus driving the peg  321  through the third groove  51 . The cover  3  is then forced to rotate clockwise about the rivet  11 . 
   In a reversed operation, the user pushes the slider  1  to return to the initial position. The L-shaped lever  6  moves with the slider  1 , and exerts a force on the spring  8 . The spring  8  drives the vertical lever  7  to swing counterclockwise, and causes the horizontal lever  5  to move and thus driving the peg  321  along the first groove  43  for rotating the cover  3  to close the lens window  21 . 
   The present invention enables easy operation of the cover  3 , simplifies the process, and mostly saves the force of the operation of the cover  3 . In addition, the present invention adopts a multi-linkage design of single freedom, which ensures a steady and reliable system. 
   It will be understood that the present invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects illustrative and not restrictive, and the invention is not be limited to the details given herein.