Continuous focusing mechanism using triangulation principle

Claim 2

In an optical instrument having a housing, a focusable objective lens arranged on said housing for focusing adjustment relative to a remote object, and a viewfinder system, the combination comprising: means forming a scene image in the viewfinder system corresponding to the scene image formed by the objective lens; an auxiliary viewfinder screen including a reference mark; auxiliary lens means forming on said auxiliary screen at least a part of said scene image, said auxiliary lens means being pivotable through an acute angle about an axis perpendicular to an optical axis defined by the objective lens; means for adjusting said auxiliary lens means for positioning of the base of an object image in said partial scene relative to said reference mark; and means coupling said auxiliary lens means and said objective lens for focusing the scene image by said latter lens upon adjusting said auxiliary lens means.

Claim 3

The combination as claimed in claim 1, wherein said means for adjusting said auxiliary lens means is manually operable from outside of said instrument housing.

Claim 4

The combination as claimed in claim 1, wherein said coupling means includes gearing on said means for adjusting said auxiliary lens means and cooperating gearing on said focusable objective lens whereby adjustment of one of said lens means is transmitted to adjust simultaneously said other lens means.

Claim 5

The combination as claimed in claim 1, wherein said coupling means for adjusting said auxiliary lens means comprises a material frictionally engageable with material on said focusable objective lens whereby adjustment of one of said lens means is transmitted to adjust simultaneously said other lens means.

Claim 6

The combination as claimed in claim 3, wherein said auxiliary lens means is mounted on said housing for pivotable movement; and including means movable about an axis to pivot said auxiliary lens means.

Claim 7

The combination as claimed in claim 5, wherein said auxiliary lens means is arranged for focusing of said objective lens means at infinity when the optical axis of said auxiliary lens means is parallel with the optical axis defined by said objective lens means.

Claim 8

In an optical instrument having a housing and a focusable objective lens arranged on said housing for focusing adjustment, and a primary viewfinder system, the combination comprising: an auxiliary viewfinder screen associated with and exclusive of the primary viewfinder system; an auxiliary lens means forming on the auxiliary viewfinder screen a partial image of the subject image formed by the focusable objective lens on the screen of the primary viewfinder system; means exterior of said housing coupled with said auxiliary lens means for pivoting said lens means from a first condition parallel with said objective lens to a second condition inclined relative to said objective lens; coupling means on said pivoting means for driving said objective lens as said pivoting means is driven manually; and a reference mark associated with and visible on said auxiliary viewfinder screen relative to which a subject image on said screen is alignable whereby a subject formed by said objective lens is focused on said primary viewfinder screen when said partial subject image is aligNed with said reference mark.

Claim 9

In an optical instrument having a housing and a focusable objective lens arranged on said housing for focusing adjustment, and a primary viewfinder system, the combination comprising: an auxiliary viewfinder screen associated with and exclusive of the primary viewfinder system; an auxiliary lens means forming on the auxiliary viewfinder screen a partial image of the subject image formed by the focusable objective lens on the screen of the primary viewfinder system; means exterior of said housing coupled with said auxiliary lens means for pivoting said lens means from a first condition parallel with said objective lens to a second condition inclined relative to said objective lens; coupling means on said pivoting means for driving said objective lens as said pivoting means is driven manually; and a reference mark associated with and visible on said auxiliary viewfinder screen relative to which a subject image on said screen is alignable whereby a subject formed by said objective lens is focused on said primary viewfinder screen when said partial subject image is aligNed with said reference mark.

Claim 10

In an optical instrument having a housing, a focusable objective lens arranged on said housing for focusing adjustment relative to a remote object, and a viewfinder system, the combination comprising: means forming a scene image in the viewfinder system corresponding to the scene image formed by the objective lens; a reference mark formed on a scene imaging screen; means for adjusting the image forming means to adjust the base of an object image relative to said reference mark; and means coupling image forming means and said objective lens for focusing the scene image by said objective lens upon adjusting the image forming means.

Claim 11

In an optical instrument having a housing, a focusable objective lens arranged on said housing for focusing adjustment relative to a remote object, and a viewfinder system, the combination comprising: means forming a scene image in the viewfinder system corresponding to the scene image formed by the objective lens; a reference mark formed on a scene imaging screen; means for adjusting the image forming means to adjust the base of an object image relative to said reference mark; and means coupling image forming means and said objective lens for focusing the scene image by said objective lens upon adjusting the image forming means.