Collimator

[kɒlimeitә]

Definition

(noun.) optical device consisting of a tube containing a convex achromatic lens at one end and a slit at the other with the slit at the focus of the lens; light rays leave the slit as a parallel beam.

(noun.) a small telescope attached to a large telescope to use in setting the line of the larger one.

Typist: Rowland--From WordNet

Definition

(n.) A telescope arranged and used to determine errors of collimation, both vertical and horizontal.

(n.) A tube having a convex lens at one end and at the other a small opening or slit which is at the principal focus of the lens, used for producing a beam of parallel rays; also, a lens so used.

Inputed by Eleanor