projector vs optical instrument

projector and optical instrument both are nouns.

Word	Noun	Adjective	Verb	Adverb
projector	Yes	No	No	No
optical instrument	Yes	No	No	No

As nouns, optical instrument is a hypernym of projector; that is, optical instrument is a word with a broader meaning than projector:

projector: an optical instrument that projects an enlarged image onto a screen
optical instrument: an instrument designed to aid vision

projector (noun)	optical instrument (noun)
an optical instrument that projects an enlarged image onto a screen	an instrument designed to aid vision
an optical device for projecting a beam of light