Patent ID: 7202616

Claim:
A synchronous control method of a web rotary printing press having a motor for driving the web rotary printing press and a central control unit generating a synchronous reference signal, and in which the motor is controlled to rotate synchronously with the synchronous reference signal supplied from the central control unit, and having braking means for braking a rotation of the motor, the method comprising: operating the braking means in response to a stop instruction supplied from the central control unit, and storing a required rotation phase of the motor at the moment; detecting a rotation phase of the motor at a time of restart; comparing the detected rotation phase of the motor with the required rotation phase of the motor; and based on a result of the comparison, performing a home position alignment of the motor at a start time of a subsequent operation by driving the motor at a low speed in a direction indicated by a synchronous reference signal supplied from the central control unit, such that the detected rotation phase of the motor synchronizes with the synchronous reference signal.