US 6,643,462 B2Granted

Variable viewfinder for wide angle shots

AssigneeLeica Camera AG

InventorsBernd Harand, Antje Brethauer

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Abstract

A variable viewfinder, for wide-angle camera shots includes three lens units. The first and third lens units, in the light direction, have negative refractive power whereas the second unit has positive refractive power. The lens units are arranged displaceably relative to one another, for changing the viewfinder magnification, in a telescope housing that includes an adaptor for insertion into a flash shoe on the camera. The first and third lens units are fixed in the telescope housing and the second lens unit is arranged in a variator that can be displaced in the telescope housing. The variator includes at least one guide pin which, through a curved track arranged in the telescope housing, engages in a longitudinal groove that runs parallel to the longitudinal axis of the telescope housing. In addition, the variator is provided in a rotating ring pushed onto the telescope housing.

Claims18

Dependent claims

A viewfinder having a variable magnification comprising:

a telescope housing having an axis defining a light direction, the telescope housing comprising at least one curved groove;
a rotating ring comprising at least one longitudinal groove which is substantially parallel to the axis, the rotating ring being rotatably positioned around the telescope housing;
a variator comprising at least one guide pin, the variator being journalled within the telescope housing and adapted to move within the telescope housing in the direction of the axis;
a first lens unit;
a second lens unit;
a third lens unit,
wherein the first, second, and third lens units are positioned in the telescope housing, wherein the first and third lens units are fixed with respect to the telescope housing, wherein the second lens unit is provided in the variator and is adapted to move with respect to the first and third lens units along the longitudinal axis to change the magnification of the viewfinder, and wherein at least one of said at least one guide pin projects through at least one of said at least one curved groove and extends into at least one of said at least one longitudinal groove.

4 more elements

Dependencies are inferred from the claim text.