Patent ID: 6865325

Claim:
A disease pattern, formed by dots discretely arranged in two dimensions, wherein said dots included in a rectangular area having a longitudinal length of Lx and a transverse length of Ly satisfy expression, D≦0.13N −1.15 (1) such that, N denotes the number of dots included in a predetermined area, and D is obtained by expression (2), wherein A(x,y) defines the number of dots, of a total of N dots, included in a rectangular area for which a line segment extended from reference coordinates ( 0 , 0 ) to an arbitrary coordinate point (x,y) is a diagonal line, D ⁡ ( L x , L y ; N ) = ∫ ∫ L x ⁢ x ⁢ ⁢ L y ⁢ [ A ⁡ ( x , y ) N - x ⁢ ⁢ y L x ⁢ L y ] 2 ⁢ ⅆ ⁢ x ⁢ ⁢ ⅆ y L x ⁢ L y ( 2 ) and wherein S 1 that is obtained by expression S 1 ⁡ ( r 1 , r 2 ) = ∫ r 1 r 2 ⁢ ⅆ r | g 1 ⁡ ( r ; r 1 , r 2 ) - g a ⁢ ⁢ v | ( 3 ) is equal to or smaller than 0.7, such that g, is obtained by dividing the average radial distribution function g(r) of each dot in the area by an integration value of g(r) over a range of from r 1 to r 2 , and g av is the average value of g 1 within the range of from r 1 to r 2 ; such that, when the dots are arranged in a square lattice to satisfy a given filling rate, r 1 and r 2 are chosen as one and four times the value of the lattice constant Dr respectively; and the dot filling rate is a value obtained by multiplying the square of the maximum diameter of a dot by the number of dots, and dividing the product by the size of the area, wherein said discrete pattern is disposed so that an average radius distribution function in said predetermined blocks becomes sufficiently smooth.