Lighting fixtures and glass enclosure having high angle anti-reflection coating

Claim 2

In a lighting fixture, a housing having an open side, a fixture mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said lamp, said high angle being 60° and above from the vertical.

Claim 3

A fixture as in claim 1 wherein said glass enclosure is provided with a second surface generally parallel to the first surface together with an additional anti-reflection coating disposed on said second surface and having the same characteristics as the first-named anti-reflection coating.

Claim 4

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers, counting from the substrate, said first layer being formed of a material having an index of refraction of approximately 2.06 and having a quarter wave optical thickness of 10,000 Angstroms plus or minus 15%, the second layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 6,500 Angstroms plus or minus 15%.

Claim 5

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers, counting from the substrate, said first layer being formed of a material having an index of refraction of approximately 2.06 and having a quarter wave optical thickness of 10,000 Angstroms plus or minus 15%, the second layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 6,500 Angstroms plus or minus 15%.

Claim 6

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of a material having an index of refraction ranging from 1.62 to 1.85, the second layer being formed of a material having an index of refraction ranging from 1.9 to 2.3, and the third layer being formed of a material having an index of refraction of 1.38, the first, second and third layers having quarter wave optical thicknesses of 1,650 Angstroms, 11,810 Angstroms and 7,300 Angstroms respectively plus or minus 15%.

Claim 7

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of a material having an index of refraction ranging from 1.62 to 1.85, the second layer being formed of a material having an index of refraction ranging from 1.9 to 2.3, and the third layer being formed of a material having an index of refraction of 1.38, the first, second and third layers having quarter wave optical thicknesses of 1,650 Angstroms, 11,810 Angstroms and 7,300 Angstroms respectively plus or minus 15%.

Claim 8

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first and third layers being formed from a mixed oxide of metals selected from the group consisting of thorium, titanium, copper, tin, chromium, magnesium, iron, nickel, cobalt, cerium, praseodymium, neodymium, samarium, and didymium and having an index of refraction of 2.06 and the second and fourth layers being formed of magnesium fluoride having an index of refraction of 1.38, the first layer having a quarter wave optical thickness of 1,340 Angstroms plus or minus 15%, the second layer having a quarter wave optical thickness of 1,430 Angstroms plus or minus 15%, the third layer having a quarter wave optical thickness fo 9,500 Angstroms plus or minus 15% and the fourth layer having a quarter wave optical thickness of 6,500 Angstroms plus or minus 15%.

Claim 9

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first and third layers being formed from a mixed oxide of metals selected from the group consisting of thorium, titanium, copper, tin, chromium, magnesium, iron, nickel, cobalt, cerium, praseodymium, neodymium, samarium, and didymium and having an index of refraction of 2.06 and the second and fourth layers being formed of magnesium fluoride having an index of refraction of 1.38, the first layer having a quarter wave optical thickness of 1,340 Angstroms plus or minus 15%, the second layer having a quarter wave optical thickness of 1,430 Angstroms plus or minus 15%, the third layer having a quarter wave optical thickness fo 9,500 Angstroms plus or minus 15% and the fourth layer having a quarter wave optical thickness of 6,500 Angstroms plus or minus 15%.

Claim 10

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces, and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of the light rays having high angles of incidence of 60° and above from the vertical.

Claim 11

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces, and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of the light rays having high angles of incidence of 60° and above from the vertical.

Claim 12

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture.

Claim 13

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture.

Claim 14

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers counting from the substrate, the first layer being formed of titanium dioxide having an index of refraction of 2.31 and an optical thickness of 1,840 Angstroms plus or minus 15%, the second layer being formed of silicon dioxide having an index of refraction of 1.45 and a quarter wave optical thickness of 6,330 Angstroms plus or minus 15%.

Claim 15

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers counting from the substrate, the first layer being formed of titanium dioxide having an index of refraction of 2.31 and an optical thickness of 1,840 Angstroms plus or minus 15%, the second layer being formed of silicon dioxide having an index of refraction of 1.45 and a quarter wave optical thickness of 6,330 Angstroms plus or minus 15%.

Claim 16

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers counting from the substrate, said first layer being formed of zirconium dioxide having an index of refraction of 2.00 and a quarter wave optical thickness of 9,930 Angstroms plus or minus 15%, said second layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 6,650 Angstroms plus or minus 15%.

Claim 17

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first and second layers counting from the substrate, said first layer being formed of zirconium dioxide having an index of refraction of 2.00 and a quarter wave optical thickness of 9,930 Angstroms plus or minus 15%, said second layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 6,650 Angstroms plus or minus 15%.

Claim 18

A lighting fixture as in claim 4 wherein the first layer is formed of a material selected from aluminum oxide, cerium oxide and lanthanum oxide, the second layer being formed from a mixed oxide of metals selected from the group consisting of thorium, titanium, copper, tin, chromium, magnesium, iron, nickel, cobalt, cerium, praseodymium, neodymium, samarium, and didymium and zirconium oxide and the third layer being formed of magnesium fluoride.

Claim 19

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of aluminum oxide having an index of refraction of 1.64 and having a quarter wave optical thickness of 6,430 Angstroms plus or minus 15%, the second layer being formed of titanium oxide having an index of refraction of 2.32 and having a quarter wave optical thickness of 11,440 Angstroms plus or minus 15% and the third layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 7,280 Angstroms plus or minus 15%.

Claim 20

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of aluminum oxide having an index of refraction of 1.64 and having a quarter wave optical thickness of 6,430 Angstroms plus or minus 15%, the second layer being formed of titanium oxide having an index of refraction of 2.32 and having a quarter wave optical thickness of 11,440 Angstroms plus or minus 15% and the third layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 7,280 Angstroms plus or minus 15%.

Claim 21

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of aluminum oxide and having an index of refraction of 1.64 and having a quarter wave optical thickness of 6,427 Angstroms, the second layer being formed of zirconium oxide and having an index of refraction of 2.00 and having a quarter wave optical thickness of 11,870 Angstroms plus or minus 15% and the third layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 7,280 Angstroms plus or minus 15%.

Claim 22

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second and third layers counting from the substrate, the first layer being formed of aluminum oxide and having an index of refraction of 1.64 and having a quarter wave optical thickness of 6,427 Angstroms, the second layer being formed of zirconium oxide and having an index of refraction of 2.00 and having a quarter wave optical thickness of 11,870 Angstroms plus or minus 15% and the third layer being formed of magnesium fluoride having an index of refraction of 1.38 and having a quarter wave optical thickness of 7,280 Angstroms plus or minus 15%.

Claim 23

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first layer being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 1,130 Angstroms plus or minus 15%, the second layer being formed of silicon dioxide having an index of refraction of 1.45 and a quarter wave optical thickness of 1,690 Angstroms plus or minus 15%, the third layer being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 9,570 Angstroms plus or minus 15% and the fourth layer being formed of silicon dioxide having an index of refraction of 1.45 and having a quarter wave optical thickness of 6,270 Angstroms plus or minus 15%.

Claim 24

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first layer being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 1,130 Angstroms plus or minus 15%, the second layer being formed of silicon dioxide having an index of refraction of 1.45 and a quarter wave optical thickness of 1,690 Angstroms plus or minus 15%, the third layer being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 9,570 Angstroms plus or minus 15% and the fourth layer being formed of silicon dioxide having an index of refraction of 1.45 and having a quarter wave optical thickness of 6,270 Angstroms plus or minus 15%.

Claim 25

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first layer being formed of zirconium oxide having an index of refraction of 2.00 and a quarter wave optical thickness of 1,390 Angstroms plus or minus 15%, the second layer being formed of magnesium fluoride having an index of refraction of 1.38 and a quarter wave optical thickness of 1,350 Angstroms plus or minus 15%, the third layer being formed of zirconium dioxide having an index of refraction of 2.00 and a quarter wave optical thickness of 9,270 Angstroms plus or minus 15%, and the fourth layer being formed of magnesium fluoride having an index of refraction of 1.38 and a quarter wave optical thickness of 6,580 Angstroms plus or minus 15%.

Claim 26

In a lighting fixture, a housing having an open side, a lamp mounted in said housing and producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle from the vertical, and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected for increasing the transmission of high angle light rays from said fixtures, said high angle being 60° and above from the vertical, said anti-reflection coating having first, second, third and fourth layers counting from the substrate, the first layer being formed of zirconium oxide having an index of refraction of 2.00 and a quarter wave optical thickness of 1,390 Angstroms plus or minus 15%, the second layer being formed of magnesium fluoride having an index of refraction of 1.38 and a quarter wave optical thickness of 1,350 Angstroms plus or minus 15%, the third layer being formed of zirconium dioxide having an index of refraction of 2.00 and a quarter wave optical thickness of 9,270 Angstroms plus or minus 15%, and the fourth layer being formed of magnesium fluoride having an index of refraction of 1.38 and a quarter wave optical thickness of 6,580 Angstroms plus or minus 15%.

Claim 27

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture, said anti-reflection coating having first, second, third, fourth, fifth and sixth layers counting from the substrate, the first, third and fifth layers being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 9,600 Angstroms, 8,450 Angstroms and 8,450 Angstroms respectively plus or minus 15%, the second, fourth and sixth layers being formed of silicon dioxide having an index of refraction of 1.45 and having quarter wave optical thicknesses of 8,450 Angstroms, 8,450 Angstroms and 4,320 Angstroms respectively plus or minus 15%.

Claim 28

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture, said anti-reflection coating having first, second, third, fourth, fifth and sixth layers counting from the substrate, the first, third and fifth layers being formed of titanium dioxide having an index of refraction of 2.31 and having a quarter wave optical thickness of 9,600 Angstroms, 8,450 Angstroms and 8,450 Angstroms respectively plus or minus 15%, the second, fourth and sixth layers being formed of silicon dioxide having an index of refraction of 1.45 and having quarter wave optical thicknesses of 8,450 Angstroms, 8,450 Angstroms and 4,320 Angstroms respectively plus or minus 15%.

Claim 29

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture, said anti-reflection coating having first, second, third, fourth and sixth layers counting from the substrate, the first, third and fifth layers being formed of zirconium dioxide and having an index of refraction of 2.00 and having an optical thickness of 9,600 Angstroms, 8,450 Angstroms and 8,450 Angstroms respectively plus or minus 15%, the second, fourth and sixth layers being formed of magnesium fluoride and having an index of refraction of 1.38 and having quarter wave optical thicknesses of 8,450 Angstroms, 8,450 Angstroms and 4,320 Angstroms respectively plus or minus 15%.

Claim 30

In a lighting fixture, a housing having an open side, a lamp mounted in said housing producing light rays passing through the open side, a glass enclosure carried by said housing and enclosing the open side and having at least one surface reflecting light rays at a high angle and an anti-reflection coating disposed on said surface, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected so that said anti-reflection coating has a high efficiency at low angles for increasing transmission of light rays from said fixture and has a reduced efficiency at high angles to reduce the transmission to thereby reduce the glare from the fixture, said anti-reflection coating having first, second, third, fourth and sixth layers counting from the substrate, the first, third and fifth layers being formed of zirconium dioxide and having an index of refraction of 2.00 and having an optical thickness of 9,600 Angstroms, 8,450 Angstroms and 8,450 Angstroms respectively plus or minus 15%, the second, fourth and sixth layers being formed of magnesium fluoride and having an index of refraction of 1.38 and having quarter wave optical thicknesses of 8,450 Angstroms, 8,450 Angstroms and 4,320 Angstroms respectively plus or minus 15%.

Claim 31

A lighting fixture as in claim 7 wherein the anti-reflection coating has a characteristic in that when the angle of incidence approaches 80°, the transmission is reduced by approximately 20% to minimize glare from the fixture.

Claim 32

A lighting fixture as in claim 17 wherein the anti-reflection coating serves as a short wave pass filter with a very steep cut-off at normal angles in which the cut-off commences at approximately 650 nanometers to 700 nanometers and in which the transmission is reduced to approximately 60% and wherein the anti-reflection coating provides a very high transmission at wave lengths below 650 nanometers.

Claim 33

A lighting fixture as in claim 18 wherein said light source is a high pressure sodium light source having its principal emission around 589 nanometers.

Claim 34

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected to provide high efficiency and increased transmission at low angles and to provide reduced transmission at high angles to thereby reduce the glare from the fixture.

Claim 35

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected to provide high efficiency and increased transmission at low angles and to provide reduced transmission at high angles to thereby reduce the glare from the fixture.

Claim 36

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected to provide high efficiency and increased transmission at low angles and to provide reduced transmission at high angles to thereby reduce the glare from the fixture, said anti-reflection coating serving s a short wave pass filter with a steep cut-off at substantially normal angles.

Claim 37

In a glass enclosure for use with a lighting fixture having an opening therein and a lamp mounted in the housing for producing light rays passing through the opening, a glass substrate having first and second generally parallel surfaces and an anti-reflection coating carried by at least one of said surfaces, said anti-reflection coating being comprised of a plurality of layers whose thicknesses have been selected to provide high efficiency and increased transmission at low angles and to provide reduced transmission at high angles to thereby reduce the glare from the fixture, said anti-reflection coating serving s a short wave pass filter with a steep cut-off at substantially normal angles.

Claim 38

An enclosure as in claim 21 wherein the cut-off commences at approximately 650 to 700 nanometers.