The present invention relates to integrated circuits. To a camshaft coupled to an electric motor through a speed reducing mechanism, a first cam and a second cam conjugate with each other are coupled. Preferably, the resultant data is amended with data obtained by re-scanning the transition. Human readable alphanumeric characters, including graphics, identifying the side of the optical disk and other basic information may also be disposed within the ring. A sectional door includes an image printed thereon and the electronic image being the printed on the door section.