Diopter adjusting device
AssigneeAsahi Kogaku Kogyo Kabushiki Kaisha
InventorTetsuro Tani
Life of this patent
Estimating the term…
Abstract
A diopter adjusting device includes a diopter adjusting lens which is guided in an optical axis thereof; a cam member which is provided rotatable about an axis which is parallel to the optical axis of the diopter adjusting lens, the cam member being provided with a cam surface on an end surface thereof; a motion-transmission lever which is rotatable about a lever axis, the lever axis being positioned between the diopter adjusting lens and the motion-transmission lever and lying on a plane normal to the optical axis; a cam follower portion and an engaging portion formed on one and the other ends of the motion-transmission lever to be engaged with the cam surface and the diopter adjusting lens, respectively; and a spring for constantly bringing the cam follower portion into contact with the cam surface.
Claims8
A diopter adjusting device comprising:
- a diopter adjusting lens which is guided in an optical axis thereof;
- a cam member which is provided rotatable about an axis parallel to said optical axis of said diopter adjusting lens, said cam member being provided with a cam surface on an end surface thereof;
- a motion-transmission lever which is rotatable about a lever axis, said lever axis being positioned between said diopter adjusting lens and said motion-transmission lever and lying on a plane normal to said optical axis;
- a cam follower portion and an engaging portion formed on one and the other ends of said motion-transmission lever to be engaged with said cam surface and said diopter adjusting lens, respectively;
- and
- a spring for constantly bringing said cam follower portion into contact with said cam surface.
A viewfinder having a diopter adjusting device comprising:
- a diopter adjusting lens guided along an optical axis thereof, and serving as a rearmost lens element of an eyepiece optical system of said viewfinder;
- a cam member which is rotatable about an axis parallel to said optical axis of said diopter adjusting lens, said cam member comprising a cam surface;
- a motion-transmission lever which is rotatable about a lever axis, said motion-transmission lever being associated with said diopter adjusting lens and said cam member to transmit motion of said cam member to said diopter adjusting lens, wherein said lever axis is positioned between said diopter adjusting lens and said motion-transmission lever and lies on a plane extending perpendicular to said optical axis;
- a cam follower portion formed on an end of said motion-transmission lever to be engaged with said cam surface;
- an engaging portion formed on the other end of said motion-transmission lever to be engaged with said diopter adjusting lens;
- and
- a spring for constantly bringing said cam follower portion into contact with said cam surface.
Dependencies are inferred from the claim text.