IMAGE FORMING APPARATUS, CONTROL METHOD THEREOF, AND CONTROL PROGRAM

PROBLEM TO BE SOLVED: To certainly remove correction patterns from an image carrier regardless of the performance of a cleaner when performing a color shift correction.SOLUTION: When determining that a cleaner has reached its durable life, a CPU forms second color shift correction patterns not including base patterns as correction patterns on an intermediate transfer body. A pattern detection sensor selectively receives diffuse reflection light and specular reflection light as reflection light reflected from a surface of the intermediate transfer belt or the correction patterns. Then, the CPU performs a color shift correction by correcting a superimposition timing of each image in accordance with an output level of a light reception detection signal output from the pattern detection sensor.