Abstract: There is provided a layer-built chemical cell device, which comprises: a positive electrode including a current collecting material and an active material layer; a negative electrode including another current collecting material and another active material layer; an electrolyte introduced in a sealed space formed by fixing together the positive electrode and negative electrode; a separator layer interposed between the positive electrode and the negative electrode. The active material layer of either the positive electrode or the negative electrode is formed by laminating a plurality of active material sub-layers containing one or more active materials, such an active material layer being depositted on a current collecting material so as to form either the positive electrode or the negative electrode.

Abstract: The irradiation device irradiates, at the time of recording main information, a first light beam having a first power and a second light beam having a second power on the pre-pits in a time-divisional manner. The light receiving device receives a reflected light of the first light beam from the pre-pits to produce a first light-receipt signal, and receives a reflected light of the second light beam from the pre-pits to produce a second light-receipt signal. The first detector detects the pre-pits based on the first light-receipt signal to produce a first detection signal, and the second detector detects the pre-pits based on the second light-receipt signal to produce a second detection signal. Then, the processor produces a logical sum of the first detection signal and the second detection signal to output a pre-pit detection signal.

Abstract: In a recording medium such as a DVD, various information such as video and audio information is recorded in a form of a plurality of recorded information pieces. Further, control information pieces prescribe the manner of reproducing the recorded information pieces. Copy information indicating whether or not the recorded information pieces are copy-prohibited is prepared and recorded for each of the recorded information pieces. In addition, aggregate copy information pieces indicating whether or not the recorded information pieces under the control by the control information piece are copy-prohibited are recorded. In accordance with the copy information and the aggregate copy information pieces, a copying system performs accurate copy management.