Adhesives inhibiting formation of artifacts in polymer based optical elements

Abstract

Inhibiting formation of optical artifacts in a multi-layer film polarizer of an optical imaging assembly that includes a polarizing beam splitter. The beam splitter may include a multilayer reflective polarizing film having at least two materials, one of which may exhibit birefringence after uniaxial orientation; an adhesive disposed on the multilayer reflective polarizing film; and at least a first prism disposed on the adhesive. The adhesive may include a plasticizer for inhibiting formation of optical artifacts in the polarizing film.

1 . A polarizing beam splitter, comprising: a polymer based polarizing film; an adhesive layer disposed on the polarizing film; and a first optical element disposed on the adhesive layer, wherein the adhesive layer comprises a crystallization inhibiting plasticizer component in an amount effective for inhibiting formation of (i) crystallized domains; (ii) particles; or (iii) a combination thereof, that cause optical artifacts in the polarizing film. 
     
     
         2 . The polarizing beam splitter according to  claim 1 , further comprising a second plasticizer component in the adhesive layer. 
     
     
         3 . The polarizing beam splitter according to  claim 2 , wherein the first and second plasticizer components are from a group consisting of: glycols, such as ethylene gycol, polypropylene glycol, di(ethylene glycol) ethyl ether, and triethylene glycol; aromatic or aliphatic esters, such as di(2-ethyhexyl) adipate and di(ethylene glycol) benzoate; and water. 
     
     
         4 . The polarizing beams splitter according to  claim 1 , wherein the adhesive is from a group consisting of multifunctional or monofunctional, aromatic or aliphatic epoxy resins along with multifunctional or monofunctional aromatic or aliphatic alcohol or amine containing curatives. 
     
     
         5 . The polarizing beam splitter according to  claim 1 , wherein the first plasticizer component amount included in the adhesive varies from between about 1 and 30 weight percent of the adhesive layer. 
     
     
         6 . The polarizing beam splitter according to  claim 5 , wherein the first plasticizer component amount included in the adhesive varies from between about 1 and 5 weight percent of the adhesive layer. 
     
     
         7 . The polarizing beam splitter according to  claim 1 , wherein the crystallization inhibiting plasticizer inhibits formation of (i) crystallized domains; (ii) particles; or (iii) a combination thereof, when subjected to light having wavelengths longer than about 420 nm. 
     
     
         8 . The polarizing beam splitter according to  claim 1 , wherein the polarizing film is a multilayer polyester polarizing film. 
     
     
         9 . An optical apparatus comprising: a polymer based optical element; an adhesive disposed on the optical element; wherein the adhesive comprises a crystallization inhibiting plasticizer component in an amount effective for inhibiting formation of (i) crystallized domains; (ii) particles; or (iii) a combination thereof in the optical element that cause optical artifacts in the optical element. 
     
     
         10 . A transparent adhesive composition comprising a crystallization inhibiting plasticizer component in an amount effective for inhibiting formation of (i) crystallized domains; (ii) particles; or (iii) a combination thereof, that cause optical artifacts in an adjacent polymer based optical element. 
     
     
         11 . The transparent adhesive composition according to  claim 10 , wherein the crystallization inhibiting plasticizer component is from a group consisting of: glycols, such as ethylene gycol, polypropylene glycol, di(ethylene glycol) ethyl ether and triethylene glycol; aromatic or aliphatic esters, such as di(2-ethyhexyl) adipate and di(ethylene glycol) benzoate; and water. 
     
     
         12 . The transparent adhesive composition according to  claim 10 , wherein the adhesive is from a group consisting of multifunctional or monofunctional, aromatic or aliphatic epoxy resins along with multifunctional or monofunctional aromatic or aliphatic alcohol or amine containing curatives. 
     
     
         13 . The transparent adhesive composition according to  claim 11  wherein the plasticizer component amount included in the adhesive varies from between about 1 and 30 weight percent of the adhesive layer. 
     
     
         14 . The transparent adhesive composition according to  claim 13  wherein the plasticizer component amount included in the adhesive varies from between about 1 and 5 weight percent of the adhesive layer. 
     
     
         15 . A polarizing beam splitter comprising: (a) a birefringent film comprising a plurality of first material layers and a plurality of second material layers, wherein the first material layers comprise a polymer selected from a group consisting of polyethylene terephthalate and copolymers of polyethylene terephthalate and polyethylene naphthalate and the second material layers comprise a copolyester; (b) at least one prism comprising a base adjacent a first major surface of the birefringent film; and, (c) an adhesive disposed between the first major surface and the birefringent film, wherein the adhesive comprises at least a crystallization inhibiting plasticizer in an amount effective for controlling the migration of the plasticizer to at least an adjacent optical polarizing film for inhibiting crystallization in the polarizing film. 
     
     
         16 . An optical assembly, comprising: (a) the polarizing beam splitter of  claim 1 , a first path being defined through the polarizing beam splitter for light in a first polarization state; and (b) at least one imager disposed to reflect light back to the polarizing beam splitter, portions of light received by the at least one imager being polarization rotated, polarization rotated light propagating along a second path from the imager and through the polarizing beam splitter. 
     
     
         17 . A projection system, comprising: (a) a light source to generate light; (b) conditioning optics to condition the light from the light source; (c) an imaging core to impose an image on conditioned light from the conditioning optics to form image light, the imaging core including at least one polarizing beam splitter of  claim 1  and at least one imager; and (d) a projection lens system to project the image light from the imaging core. 
     
     
         18 . A method of stabilizing a polymer based optical element, the method comprising:
 disposing a material on a polymer based optical element, the material comprising a crystallization inhibiting plasticizer component in an amount effective for inhibiting formation of (i) crystallized domains; (ii) particles; or (iii) a combination thereof, that cause optical artifacts in an adjacent polymer based optical element; and,   passing radiation through the material and the optical element.   
     
     
         19 . The method of  claim 18 , wherein the material comprises an adhesive. 
     
     
         20 . The method of  claim 19  wherein the disposing comprises an adhesive layer wherein the crystallization inhibiting plasticizer component is from a group consisting of: glycols, such as ethylene glycol, polypropylene glycol, di(ethylene glycol) ethyl ether, and triethylene glycol; aromatic or aliphatic esters, such as di(2-ethyhexyl) adipate and di(ethylene glycol) benzoate; and water. 
     
     
         21 . The method of  claim 20 , wherein the disposing comprises having the crystallization inhibiting plasticizer component included in the adhesive by an amount that varies from between about 1 and 30 weight percent of the adhesive layer. 
     
     
         22 . The method of  claim 20  wherein the disposing comprises having the crystallization inhibiting plasticizer component included in the adhesive by an amount that varies from between about 1 and 5 weight percent of the adhesive layer. 
     
     
         23 . The method of  claim 21  wherein the disposing comprises having adhesive from a group consisting of multifunctional or monofunctional, aromatic or aliphatic expoxy resins along with multifunctional or monofunctional aromatic or aliphatic alcohol- or amine-containing curatives. 
     
     
         24 . The method of  claim 18 , wherein the passing radiation has a wavelength that is longer than about 420 nm.