Patent ID: 6249376
Filing Date: 2001-06-19
Classification: G03B

Abstract:
A projection screen comprising a Fresnel lens and lenticular lenses in combination, wherein, when the pitch of the lenticular lenses is indicated by p.sub.L, and the pitch of the Fresnel lens is indicated by p.sub.F, and when p.sub.E and p.sub.H are defined as follows: in the case where p.sub.L >p.sub.F,p.sub.E =1.0/(1.0/p.sub.F -[p.sub.L /p.sub.F ]/p.sub.L) (i)p.sub.H =1.0/(1.0/p.sub.L -1.0/p.sub.F +[p.sub.L /p.sub.F ]/p.sub.L) (ii), andin the case where p.sub.F >p.sub.L,p.sub.H =1.0/(1.0/p.sub.L -[p.sub.F /p.sub.L ]/p.sub.F) (iii)p.sub.E =1.0/(1.0/p.sub.F -1.0/p.sub.L +[p.sub.F /p.sub.L ]/p.sub.F) (iv)([X]: the integer part of X),the relationshipp.sub.E /p.sub.H.gtoreq.2.4 or p.sub.H /p.sub.E.gtoreq.2.4is fulfilled.