for producing a narrow beam of light; for approximating a point-like source of light, e.g. for searchlight, for cinematographic projector (producing narrow beams by optical means external to lamp F21V)

Full Title

Lamps for purposes other than general lighting (H01K9/00 - H01K13/00 take precedence) > for producing a narrow beam of light; for approximating a point-like source of light, e.g. for searchlight, for cinematographic projector (producing narrow beams by optical means external to lamp F21V)