Drive control method and drive control apparatus for processing machine

An upstream-side printing unit group (20A) and a downstream-side printing unit group (20B), respectively, are driven by separate prime motors (1A, 1B) and synchronously controlled. In addition to rotary encoders (8A, BC) for the upstream-side and downstream-side prime motors (1A, 1B), rotary encoders (8B, 8D) are provided on a last impression cylinder (23) of the upstream-side printing unit group (20A) and a first transfer cylinder (24) of the downstream-side printing unit group (20B) to detect differences between rotational phases, which the upstream-side and downstream-side printing unit groups (20A, 20B) should have, and the actual rotational phase of the last impression cylinder (23) of the upstream-side printing unit group (20A) or the first transfer cylinder (24) of the downstream-side printing unit group (20B). In accordance with the rotational phase differences, the rotational speeds of the prime motors (1A, 1B) are corrected.