Patent ID: 11971567
Assignee: DAI NIPPON PRINTING CO., LTD.
Field: Optics (Instruments)
Classification: CPC G  H | IPC G

Claim 2:
3. The optical film according to claim 1, wherein when the measurements at the 11 measurement points are used to calculate a sum of square of a difference in a* between adjacent measurement points and square of a difference in b* between the adjacent measurement points, and when the sum is defined as S, S can be expressed by the following formula 3; and when S is calculated for each of 10 adjacent points and a maximum value of S among the 10 points is defined as SMAX, SMAX is 0.010 or more and 0.050 or less:

S={a*n−a*n1}2+{b*n−b*n1}2  (formula 3).