Patent ID: 6830817
Filing Date: 2004-12-14
Classification: C03C

Abstract:
A coated article including a coating supported by a glass substrate, the coating comprising:top, middle and bottom dielectric coating portions having effective or average indices of refraction nT, nM and nB, respectively; first and second infrared (IR) reflecting layers comprising silver (Ag), wherein the first IR reflecting layer comprising Ag is located between the bottom and middle dielectric coating portions, and the second IR reflecting layer comprising Ag is located between the middle and top dielectric coating portions, and wherein the top, middle and bottom dielectric coating portions do not include the IR reflecting layers and also do not include contact layers which contact the IR reflecting layers; the bottom dielectric coating portion comprising a first dielectric layer comprising titanium oxide provided between the first IR reflecting layer and the glass substrate; the middle dielectric coating portion comprising a second dielectric layer having an index of refraction 1.8<=n<=2.2 provided between the first and second IR reflecting layers, wherein the second dielectric layer has an index of refraction n less than the index of refraction n of the first dielectric layer; the top dielectric coating portion comprising a third dielectric layer comprising titanium oxide provided over the first and second IR reflecting layers and a fourth dielectric layer comprising silicon oxide provided over the third dielectric layer comprising titanium oxide; wherein the coated article has a visible transmission of at least 70%; and wherein the average or effective indices of refraction nT, nM and nB of the top, middle and bottom dielectric coating portions respectively have values so that nTMB.