Patent ID: 7342716

Claim:
A transparent substrate having two generally opposed major surfaces, wherein a multiple cavity low-emissivity coating is provided on a desired one of the major surfaces, the coating comprising, in sequence from said desired major surface outward: a) a first transparent dielectric film region; b) a first infrared-reflection film region; c) a second transparent dielectric film region; d) a second infrared-reflection film region; e) a third transparent dielectric film region; f) a third infrared-reflection film region; g) a fourth transparent dielectric film region; wherein the transparent substrate is part of a multiple-pane insulating glazing unit that includes a second pane, wherein the insulating glazing unit has at least one between-pane space, said desired major surface being exposed to a between-pane space of the insulating glazing unit, wherein the coating has a metal/dielectric ratio of at least 0.22 and yet the insulating glazing unit has a visible transmittance of 0.65 or more, the metal/dielectric ratio being defined as the combined thickness of the first, second, and third infrared-reflection film regions divided by the combined thickness of the first, second, third, and fourth transparent dielectric film regions, the coating having a primary dielectric-region ratio of less than 0.75, the primary dielectric-region ratio being defined as the thickness of the first transparent dielectric film region divided by the thickness of the fourth transparent dielectric film region.