Patent ID: 8454109

Claim:
An image forming device comprising: a droplet ejecting head that ejects droplets with respect to a recording medium, and that can form a plurality of dots of different diameters; and a control unit that, on the basis of image data expressing a tone value of each pixel in an image that is to be formed on the recording medium, controls sizes of droplets ejected from the droplet ejecting head such that, in a case in which the tone value is within a predetermined tone range, first dots, whose diameter is greater than a predetermined diameter, are formed at a recording rate that satisfies following formula (1), and second dots, whose diameter is less than or equal to the predetermined diameter, are formed at a recording rate corresponding to the tone value: [ Numerical ⁢ ⁢ Expression ⁢ ⁢ 1 ] ∑ i ≤ i s ⁢ α i ⁢ R i ⁡ ( D i / L ) 2 = 1 ( 1 ) wherein i is a number from 1 to N that is given to respective dots in order from a smallest diameter with a number of the plurality of types of dot diameters being N, α i is a coefficient that satisfies π/4≦α i ≦1 of an ith dot, R i is a recording rate of the ith dot, D i is a diameter of the ith dot, L is a length of one side of a pixel, and i s is a number of a dot of the predetermined diameter.