Patent ID: 7071602

Claim:
A filter for a plasma display panel comprising: an antireflection optical film having a colorant; and the colorant forming a proportion of the optical film whereby when red light in a visible light range emitted from the plasma display panel is passed therethrough the optical film with the proportion of the colorant, a positional relation of a before passage position and an after passage position in a CIE xy chromaticity diagram of the red light, satisfies at least one of the following formulae (1) and (2) relating to changes in coordinates x,y, and the following formulae (3) and (4) relating to distances from standard values: formulae relating to coordinates x,y: Δx>0.003 (1) Δy<0.003 (2) where Δx is the change in coordinate x, and Δy is the change in coordinate y, and formulae relating to distances from standard values: Δ D ( rn )<−0.003 (3) Δ D ( rc )<−0.003 (4) where ΔD(rn) is the change in the distance from a point (x, y)=(0.67, 0.33), and ΔD(rc) is the change in the distance from a point (x, y)=(0.64, 0.33), and ΔD(rn) and ΔD(rc) respectively denote that when ΔD(rn) and ΔD(rc) take positive values, the distances become long, and when ΔD(rn) and ΔD(rc) take negative values, the distance become short.