High order wave plate correction of polariscopic effects in windows having infrared filtering

Claim 2

A light-transmitting window apparatus comprising an inboard side through which transmitted light may exit from said apparatus, and an outboard side, through which light may enter said apparatus, said apparatus comprising, in combination, a mounting structure having an aperture therein, said aperture containing a multiplicity of light-transmitting layer-like members mounted substantially transverse to the plane of the aperture including, from the outboard side, a first, structural, transparent, stressed plastic member; a wave plate of at least four wave lengths retardation; a fixed light-polarizing member; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus.

Claim 3

The invention of claim 1 wherein said wave plate is capable of providing at least seven wave lengths of retardation.

Claim 4

The invention of claim 2 wherein the plane of the optic axis of the wave plate is at about a 45* angle to an axis of the fixed light-polarizing element.

Claim 5

The invention of claim 2 wherein said system to substantially reduce the transmission of infrared radiation comprises infrared absorbing dyes.

Claim 6

The invention of claim 4 wherein said infrared absorbing dyes comprise bis-(cis-1,2-(alkyl, hydrogen, aryl or heterocyclic)ethylene-1,2-dithiolate)s.

Claim 7

The invention of claim 5 wherein said bis-(cis-1,2-(alkyl, hydrogen, aryl or hetercyclic)ethylene-1,2-dithiolate)s comprise a mixture of

Claim 8

The invention of claim 2 wherein said system comprises a thin metallic infrared reflecting layer.

Claim 9

The invention of claim 7 wherein said metallic layer comprises gold.

Claim 10

The invention of claim 3 wherein said wave plate comprises uniaxially oriented polyethylene terephthalate.

Claim 11

The invention of claim 3 wherein said wave plate is laminated to said stressed plastic member on the inboard side thereof.

Claim 12

The invention of claim 3 wherein said apparatus additionally contains a second transparent, synthetic plastic member inboard of said first structural member and outboard of said light-polarizing member.

Claim 13

The invention of claim 11 wherein said wave plate is laminated to said second synthetic plastic member.

Claim 14

The invention of claim 3 wherein said wave plate and said light-polarizing member comprise a single composite structure comprising, from the outboard side, said wave plate; a transpArent synthetic plastic support element; a first transparent protective layer for said light-polarizing member; said light-polarizing member; and a second transparent protective layer for said light-polarizing member.

Claim 15

The invention of claim 13 wherein said composite structure additionally contains a transparent synthetic plastic support element inboard of said second transparent protective layer for said light-polarizing material and affixed thereto.

Claim 16

The invention of claim 3 wherein a rotatable light-polarizing member is positioned inboard of said fixed light-polarizing member.

Claim 17

The invention of claim 15 wherein said rotatable light-polarizing member comprises said system for substantially reducing the transmission of infrared radiation.

Claim 18

The invention of claim 15 wherein said apparatus additionally contains a second structural, transparent, synthetic plastic member inboard of said first structural member and outboard of said light-polarizing member.

Claim 19

A light-transmitting window apparatus comprising an inboard side through which transmitted light exits from said apparatus and an outboard side through which light enters said apparatus, said apparatus comprising, in combination, a mounting structure having an aperture therein, said aperture containing a multiplicity of light-transmitting layer-like members mounted substantially transverse to the plane of the aperture comprising, from the outboard side; a first structural, transparent, stressed plastic member comprising polymethyl methacrylate of approximately 0.5 inch in thickness; a second structural, transparent plastic member comprising polymethyl methacrylate of approximately 0.25 inch in thickness; a composite structure comprising a synthetic plastic wave plate of at least four wave lengths retardation approximately 1.5 to 5 mils, in thickness; a transparent plastic support element approximately 30 to 125 mils. in thickness; a first transparent protective layer of cellulose acetate butyrate approximately 4 to 30 mils. in thickness; a polymeric light-polarizing member approximately 0.75 to 1.5 mils. in thickness; a second transparent protective layer of cellulose acetate butyrate of approximately 4 to 30 mils. in thickness; and a second transparent plastic support element of approximately 30 to 125 mils. in thickness; and a rotatable member comprising a transparent plastic support element of approximately 30 to 125 mils. in thickness; a first transparent protective layer of cellulose acetate butyrate approximately 4 to 30 mils. in thickness; a polymeric light-polarizing member approximately 0.75 to 1.5 mils. in thickness; a second transparent protective layer of cellulose acetate butyrate approximately 4 to 30 mils. in thickness; a second plastic transparent support element approximately 30 to 125 mils. in thickness; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus. 19 The invention of claim 18 wherein said wave plate is capable of providing at least seven wave lengths retardation.

Claim 20

The invention of claim 19 wherein the plane of the optic axis of the wave plate is at about a 45* angle to an axis of the fixed light-polarizing element.

Claim 21

The invention of claim 20 wherein said system to substantially reduce the transmission of infrared radiation comprises infrared absorbing dyes.

Claim 22

The invention of claim 21 wherein said dyes are incorporated in a cellulose acetate butyrate protective layer.

Claim 23

The invention of claim 22 wherein said dyes are incorporated in said second cellulose acetate butyrate protective layer of said rotatable member.

Claim 24

The invention of claim 23 wherein said infrared absorbing dyes comprise bis-(cis-1,2-(alkyl, hydrogen, aryl or heterocyclic)ethylene-1,2-dithiolate)s.

Claim 25

The invention of claim 24 wherEin said bis-(cis-1,2-(alkyl, hydrogen, aryl or heterocyclic)ethylene-1,2-dithiolate)s comprise a mixture of

Claim 26

The invention of claim 19 wherein said system comprises a thin metallic infrared reflecting agent.

Claim 27

The invention of claim 26 wherein said metallic layer comprises gold.

Claim 28

The invention of claim 27 wherein said thin metallic film is incorporated between said wave plate and said transparent plastic support element next adjacent thereto.

Claim 29

The invention of claim 20 wherein each of said light-polarizing members comprise a transparent sheet of polyvinyl alcohol containing substantially oriented molecules of dehydrated polyvinyl alcohol.

Claim 30

The invention of claim 28 wherein said wave plate comprises uniaxially oriented polyethylene terephthalate.

Claim 31

The invention of claim 30 wherein said plastic support elements comprise polymethyl methacrylate.

Claim 32

A light-transmitting window apparatus which comprises a stressed synthetic plastic light-transmitting element having stress-induced birefringent areas; a wave plate of at least four wave lengths of retardation; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus.

Claim 33

A light-transmitting window apparatus which comprises a stressed synthetic plastic light-transmitting element having stress-induced birefringent areas; a wave plate of at least four wave lengths of retardation; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus.

Claim 34

The invention of claim 32 wherein said wave plate comprises at least seven wave lengths of retardation.

Claim 35

The invention of claim 33 wherein said wave plate comprises uniaxially oriented polyethylene terephthalate.

Claim 36

A light-transmitting window apparatus which comprises a composite structure comprising a light-polarizing element; a wave plate of at least seven wave lengths of retardation bonded thereto; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus.

Claim 37

A light-transmitting window apparatus which comprises a composite structure comprising a light-polarizing element; a wave plate of at least seven wave lengths of retardation bonded thereto; and a system for retarding, by absorption or reflection, the transmission of infrared radiation through said apparatus.

Claim 38

The invention of claim 35 wherein said wave plate comprises uniaxially oriented polyethylene terephthalate.

Claim 39

The invention of claim 36 wherein the optic axis of said wave plate is at a 45* angle to the axis of said light-polarizing element.

Claim 40

The invention of claim 37 wherein said wave plate and said light-polarizing element are each interposed between synthetic plastic protective layers.

Claim 41

The invention of claim 38 wherein said synthetic plastic protective layers comprise cellulose acetate butyrate.

Claim 42

The invention of claim 39 wherein at least one surface of said composite structure has coated thereon a marresistant coating.