Abstract: An electronic device includes: a plurality of input terminals; and a control unit in which an operation for determining contents of a digital signal inputted through one input terminal of the plurality of input terminals is repeated while the input terminal is switched to another, and when it is confirmed that a predetermined identifier is included in a digital signal inputted through a certain input terminal, processing is then performed upon real data included in the digital signal inputted through the certain input terminal.

Abstract: In an optical disk, while restricting a program area which has been defined as to the normal disk and on which a user can record arbitrary information, a remaining area located outside this restricted program area is previously secured as an advertisement area where an advertisement-purpose visible image is formed. In the case that an advertisement-purpose recordable optical disk is loaded on an optical disk recording apparatus, the optical disk recording apparatus accesses via a pubic line network to an advertisement information distributing apparatus so as to acquire advertisement image information. Next, the optical disk recording apparatus irradiates an optical beam to the advertisement area in response to the acquired advertisement image information so as to reproduce the advertisement image.

Abstract: A method is designed for forming a visual image having a specified shape on a surface of an optical disk by using an optical writing process of irradiating a laser beam onto the surface of the optical disk to form pits. The optical disk is normally capable of recording information on the surface thereof by the optical writing process. The method is carried out by the steps of acquiring image formation information associated to a visual image to be formed, forming the visual image on the surface of the optical disk based on the acquired image formation information by using the optical writing process, and recording the image formation information together with the formed visual image on the surface of the same optical disk.