| 摘要 |
PROBLEM TO BE SOLVED: To provide a laminated polyester film which reduces deflection in a chassis of a reflection sheet and is excellent in brightness unevenness.SOLUTION: There is provided a laminated polyester film in which a polyester layer (B) is laminated on at least one side of a polyester layer (A) containing cavities inside. If the center of gravity of a shape formed by removing the cavity part is defined as the area center and the thickness of the whole film is defined as 1 in an arbitrary cross-section in a thickness direction of the film, a distance X from the area center to a nearer film surface is 0.35 or more and 0.48 or less and the rigidity at a film bending angle at 15° measured by a taper-type rigidity tester satisfies the following expression: (1) 0.15≤&Dgr;S≤0.70 and (2)&Dgr;S≤-8X+4, provided &Dgr;S: the difference in rigidity between the front side and the back side &Dgr;S=SB-SA)/((SA+SB)/2) and SB: the rigidity (mN m) when bending to the B layer side and the rigidity (mN m) when bending to the A layer side. |
