Patent ID: 7659669

Claim:
A plasma display panel comprising: a pair of substrates; at least a pair of electrodes provided between the pair of substrates; a phosphor layer provided between the pair of electrodes; and an anti-reflection layer provided on an outer side of one substrate of the pair of substrates, wherein the one substrate of the pair of substrates has light-transmitting properties, wherein the anti-reflection layer has a plurality of pyramid-shaped projections, wherein one of the plurality of pyramid-shaped projections is surrounded by six adjacent pyramid-shaped projections of the plurality of pyramid-shaped projections, wherein each side of a base which forms a pyramid shape of one of the plurality of pyramid-shaped projections is in contact with a side of a base which forms a pyramid shape of an adjacent pyramid-shaped projection of the plurality of pyramid-shaped projections, wherein each of the intervals between the apexes of the plurality of pyramid-shaped projections is 350 nm or less, wherein a height of each of the plurality of pyramid-shaped projections is 800 nm or more, wherein a fill rate of bases of the plurality of pyramid-shaped projections per unit area is 80% or more, wherein a ratio of the height to a width of each of the plurality of pyramid-shaped projections is 5 or more, wherein the one of the plurality of hexagonal pyramid-shaped projections has a first portion having a first refractive index and a second portion having a second refractive index different from the first refractive index, the first portion being closer to the other substrate than the second portion, and the first refractive index having a closer refractive index to a refractive index of the other of the pair of substrates than the second refractive index.