Selective reflecting

A projection screen having at least one asymmetric diffusion layer of material enclosing oriented glass fibers constructed and arranged so that there is an index of refraction difference between the glass fibers and said material enclosing said glass fibers.

A projection screen having a reflective layer,

• and a diffusion layer characterized by asymmetry in the z plane perpendicular to the plane of said screen such that light traveling through the diffusion layer towards the reflective layer is diffused less than the light reflected back through the diffusion layer from said reflective layer.

In a screen comprised of plastic film materials and at least one adhesive, wherein some of the said plastic film materials comprise frequency selective filters, at least one adhesive and plastic film material in front of said frequency selective filters that have a property from the group of (a) low birefringence and (b) substantially uniform birefringence and oriented for maximum transmission of light of one of a desired polarization.

A projector light source comprising,

• a first light source that emits light energy over a first relatively broad range of optical frequencies, and
• a second light source constructed and arranged to emit light energy over a narrow frequency range of optical frequencies that is significantly less than said broad range.

A light projection system comprising,

• a source of polarized light characterized by polarization of light energy in a predetermined number of narrow frequency regions in a first direction and of light energy in the frequency regions between said narrow frequency regions in a second direction,
• a screen having a polarizer constructed and arranged so that light energy in said narrow frequency regions is reflected and in other frequency regions is at least partially absorbed.