As illustrated in FIG. 4, determination unit 32 determines whether each of pixel rows 22b1 and 22b21 to 22b25 (hereinafter also referred to as non-writing lines 22b1 and 22b21 to 22b25) located in range R1 has the correlation with pixel row 22a1 (hereinafter also referred to as writing line 22a1). Determination unit 32 determines whether each of pixel rows 22b21 to 22b25 and 22b31 to 22b35 located in range R2 has the correlation with pixel row 22a2 (hereinafter also referred to as writing line 22a2). Similarly, determination unit 32 determines whether each of pixel rows 22b31 to 22b35 and 22b41 to 22b45 located in range R3 has the correlation with the pixel row 22a3 (hereinafter also referred to as writing line 22a3), and determines whether each of pixel rows 22b41 to 22b45 and 22b5 located in range R4 has the correlation with pixel row 22a4. Non-writing line group 22b2 is located between writing lines 22a1 and 22a2, and constructed with non-writing lines 22b21 to 22b25 in the example of FIG. 4. Non-writing line group 22b3 is located between pixel rows 22a2 and 22a3, and constructed with pixel rows 22b31 to 22b35 in the example of FIG. 4. Non-writing line group 22b4 is located between pixel rows 22a3 and 22a4, and constructed with pixel rows 22b41 to 22b45 in the example of FIG. 4.
