Definition of projectors:
(n) :
An optical device that projects a beam of light, especially one used to project an image (or moving images) onto a screen.
(n) :
Someone who devises or suggests a project; a proposer or planner of something.
(n) :
That which projects or launches something.
(n) :
(psychology) One who projects, or ascribes his/her own feelings to others.
(n) :
(mathematics) An operator that forms a projection.