Diffractive color filter
AssigneeRCA Corporation
InventorKarl H. Knop
Life of this patent
Estimating the term…
Abstract
A diffractive color filter, comprised of proximately disposed diffraction grating and lenticular lens structures, which may be embossed on plastic sheet, cooperates with an imaging lens to produce color stripes or color spots of an image on a photosensitive surface. The diffractive color filter may be used, for example, as a color-encoding stripe filter of a color TV camera.
Claims13
A diffractive color filter for use in a polychromatic-light imaging system including an imaging lens and a photosensitive surface situated in an image plane of said lens, said lens having an f-number F.sub.c equal or greater than a minimum f-number F.sub.c.sup.min ;
- said filter comprising:
- a lenticular lens array having a lens periodicity L, a focal length f and an effective f-number F.sub.L proportional to f/L, said array being adapted to be situated with its focal plane substantially in coincidence with said photosensitive surface,
- a diffractive structure situated substantially in proximity to said array, said diffractive structure including a phase grating having a predetermined grating profile S(x) and grating line spacing d, where d is larger than a certain wavelength .gamma. of said polychromatic light, and
- wherein the following relationship exists:
- F.sub.c.sup.min .gtoreq.d/.gamma.
Dependencies are inferred from the claim text.