| 摘要 |
PROBLEM TO BE SOLVED: To stabilize the operation of a watch by arranging a multiple-joined photocell in which a plurality of basic batteries have been laminated in the incident direction of light, on the back of the glass around nearly all the circumference, so that even if a part of the cell is shaded, sufficient voltage can be supplied. SOLUTION: The inside surface of the glass 2 of a watch P is covered with a layer 14 of transparent conductive oxide(TCO) of a thickness of as thin as possible, for instance, of a thickness of 2 to 3/10nm. On this layer 14, in-series connected basic (solar) batteries 11 to 13 are vertically stacked so as to constitute a photocell C, and are arranged around nearly all the circumference of the glass 2, and are connected to a power-supply circuit by means of a conductive wire that has been fixed to the layer 14. The output voltage of the photocell C becomes the voltage summed up the respective voltages of the batteries 11 to 13, and even in the time when brightness of light is very low, the voltage of approximately 1.2 to 1.5V by which the watch can be sufficiently operated can be secured. Further, since the cell C is arranged around nearly all the circumference of the glass 2 and light can be received at its maximum, the variation of output voltage due to partial shading can be eliminated, and the watch P can be stably operated. |
