Patent ID: 8967848
Filing Date: 2015-03-03
Classification: B82Y,H01L,H05B,Y02B

Abstract:
1. A lighting device comprising: an organic photoelectric conversion element; an organic electroluminescence element; a secondary cell; an electrical connection which connects the organic photoelectric conversion element, the organic electroluminescence element, and the secondary cell to each other; and a control section which controls the electrical connection, wherein the control section controls the electrical connection so that, when the organic photoelectric conversion element receives an outer light to generate electricity and charges the secondary cell, a reverse bias voltage is applied to the organic electroluminescence element, and, when the organic electroluminescence element is supplied with electric power from the secondary cell to emits light, a reverse bias voltage is applied to the organic photoelectric conversion element, wherein the control section switches, on charging the secondary cell, the connection of the secondary cell from the organic photoelectric conversion element to the organic electroluminescence element when charging voltage of the secondary cell becomes higher than or equal to overcharge protection voltage, and wherein, when the charging voltage of the secondary cell reaches the overcharge protection voltage, electrical current is discharged to the organic electroluminescence element until the charging voltage decreases to a predetermined voltage which is lower than the overcharge protection voltage.