PURPOSE: To guarantee the permanent operation of a semiconductor element by connecting a solar battery via a diode and a thin film secondary battery respectively in parallel with the semiconductor element having a volatile memory.
CONSTITUTION: A totally solid-state thin film secondary battery is formed by using a TiS2 thin film as a positive electrode, an Li4SiO4-Li3PO4 group thin film as an electrolyte film and an Li metal as a negative electrode. The secondary battery and the solar battery are mounted together with a nonvolatile memory such as microcomputer and memory by the technology such as the tape carrier system so as to be incorporated in the form of a cash card. In the circuit constitution, the memory cell is connected in parallel with the secondary battery and the solar battery as shown in Fig. When a light is incoming, the solar battery is activated to charge the secondary battery and feed power to the memory cell or the like. When the light is interrupted conversely, the power is supplied from the secondary battery to the memory cell so as to form a thin nonvolatile memory device.
ITOU YUKIO
KANEBORI KEIICHI
KIRINO FUMIYOSHI
KUDOU SANEHIRO
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