Abstract:
A view finder comprises three lenses which are mounted for pivotal movement about three separate axis. Cam means are provided for moving the lenses between a viewing position and folded positions. The cam means includes a single plate movable along a rectilinear path to effect position of the lenses.

Description:
This is a continuation of application Ser. No. 255,091, filed Oct. 7, 1988 now abandoned. 
    
    
     CROSS REFERENCE TO RELATED APPLICATION 
     Reference is made to commonly assigned copending application U.S. Ser. No. 255,187 entitled CAMERA VIEW FINDER and filed concurrently herewith in the names of Richard A. Gates and Jeffrey R. Stoneham. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to view finder devices for use in cameras and more particularly to an improved view finder device in which a plurality of lenses can be selectively positioned in a viewing position or optical path. 
     Mechanisms are know which change the magnification of a view finder in cameras having more than one photographic lens and in cameras for producing special effects such as pseudo tele or pseudo pan. However, in general, such mechanisms are complicated and capable of providing only two levels of magnification. 
     It is an object of the present invention to provide a compact view finder which can provide at least three levels of magnification. 
     SUMMARY OF THE INVENTION 
     In accordance with the invention, a view finder comprises three lenses which are pivotally mounted for pivotal movement about three separate axis respectively. Cam means are provided for moving the respective lenses selectively between the same viewing position and separate folded positions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects and advantages will become apparent from the following description taken in connection with the accompanying drawings wherein: 
     FIG. 1 is a partially exploded perspective view of a view finder device in accordance with the invention; and 
     FIGS. 2 and 3 are views similar to FIG. 1 showing the parts in other positions. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to the drawings, there is shown a view finder device for a photographic camera. To simplify the disclosure, camera parts not necessary for an understanding of the invention have been omitted. For example, the eye lens and front element are not shown and the disclosure is limited to apparatus For moving the movable lens element. 
     Referring to FIG. 1 of the drawings, there is shown a view finder comprising three lenses 10, 12 and 14 mounted in frames 16, 18 and 20 respectively. In a typical pseudo tele pan camera lens 10 might be the normal view finder lens. Lens 12 might be used to provide magnification of the scene in the view finder for pseudo tele purposes and lens 14 might be used to provide panoramic views for pseudo pan purposes. 
     Frame 16 is of rectangular configuration and comprises a pair of flanges 22 extending from one side thereof which are pivotaly mounted on pins 24 fixed to the camera body (not shown). A third pin 26 extends from the upper flange 22 and functions as a cam pin for pivoting the frame about the axis of pins 24 as will later be described in more detail. 
     Frame 20, positioned in spaced parallel relationship with frame 16, is similar in configuration to frame 16 and includes a pair of flanges 28 pivotally mounted on a pair of pins 30 fixed to the camera body. A cam pin 32 extends upward from the upper flange 28 and provides a means for pivoting the frame 16 about the axis of pins 30, an axis parallel to the axis of pins 24. 
     The third frame 18, positioned in perpendicular relationship with frames 16 and 20, is also similarly configured and provided with a pair of spaced flanges 34 pivotally mounted on a pair of pins 36 fixed to the camera body. The frame 18 is positioned between the flanges 22 and 28 and pivots about the horizontal axis of pins 36 which axis is perpendicular to that of pins 24 and that of pins 30. An elongated cam arm 38 extending perpendicularly from the plane of frame 28 and pivotally connected to frame 28 by pin 39 is provided with an upwardly extending pin 40 at its end to provide a means for pivoting the frame 18 about the axis of pins 36. In the position of the parts shown in FIG. 1, the lens 12 is positioned in the sight plane 42 and is the operative lens. 
     To position the lenses, a cam plate 44 is positioned over the frame assemblage and suitably supported in guides 45 for rectilinear reciprocal movement in the direction of the arrow. The cam plate 44 is provided with three slots 46, 48 and 50. Pin 26 of frame 16 is received by slot 46, pin 40 of frame 18 by slot 50 and pin 32 of frame 20 by slot 48. Movement of the plate 44 to the right and left from the position shown in FIG. 1 will position the frame 18 out of the viewing plane and position one of the frames into the viewing plane depending upon the direction of movement as will now be described. 
     If plate 44 is moved to the right (R) portion (a) of slot 46 will cam pin 26 and cause frame 16 to pivot counterclockwise to the position shown in FIG. 2. Simultaneously portion (a) of slot 50 will cam pin 40 and cause frame 18 to pivot upward to the position shown in FIG. 2. Frame 16 is thus positioned in the sight plane and frame 18 is moved out of it. During this movement, pin 32 will ride in the straight portion (b) of slot 48 and no movement of frame 20 will occur. 
     If the cam plate 44 is moved to the left from the position shown in FIG. 1, pin 40 will be cammed by portion (b) of slot 50 to again pivot frame 18 out of the sight plane. In this case, however, pin 26 will ride in the straight portion (b) of slot 46 and no movement of frame 16 will occur. However, pin 32 of frame 20 will be cammed by portion (a) of slot 48 to position frame 20 in the sight plane as shown in FIG. 3. 
     The disclosed view finder device thus constitutes a simple compact device for selectively positioning at least three lenses in a sight plane. 
     While the invention has been particularly shown and described with reference to a preferred embodiment thereof, it will be understood by those skilled in the art that various changes may be made without departing from the scope of the invention as defined by the appended claims.