| 摘要 |
PURPOSE:To make it possible to obtain an accurate density pattern by inclining the array direction of linear lattice pattern at pi/4 radian to a measurement direction and by bearing a fixed relation between the pitch of this pattern and that of a space frequency at which MTF is bo be measured. CONSTITUTION:Linear lattice patterns are arranged in measurement pattern region 1. This array direction is inclined at an angle of pi/4 radian, i.e. 45 degrees to measurement direction A and B. White plane part 2 and black plane part 3 are therefore perpendicular to or in parallel to measurement directions A and B, and a pattern for measuring MTF of zero in space frequency and for normalizing the value of MTF at a space frequency to be measured is formed. Then, the pattern in region 1 is scanned as that of a space period of pitch Ps and pitch Ps is so set for pitch P characteristics of the lattice of the pattern that Ps=P/sin(pi/4)=2<1/2>P. For the purpose, setting pitch P of the lattice to a value 2<1/2> times as much as pitch Ps makes it possible to measure MTF of the space frequency of pitch Ps in both directions A and B. |
