US Patent 7432945 Exposure apparatus and image forming apparatus

An exposure apparatus includes a line head and a rotatable photosensitive drum, which is exposed by light from the line head. The line head includes N (“N” being 2 or greater) EL element column. In each EL element column, the area S of a light-emitting pixel of the EL element is constant within a corresponding column. When the column number of the EL element columns is from 1 to N, the area of the light-emitting pixel of the EL element in each column is Si=S1/(2n−1) (where, “i” is the column number of each EL element column and a natural number from 1 to N, and “S1” is the area of the light-emitting pixel of the EL element of a first column). One or more EL elements selected from N EL elements within the N EL element columns perform exposure on the same unit drawing region on the photosensitive drum.