| 摘要 |
PURPOSE:To confirm a position of a lightout lighting lamp by impressing a scanning signal on the switches connected to a plurality of address lines to readout lighting data on a plurality of the data lines. CONSTITUTION:When a first group of lighting lamps 10a are lights-out caused by core failure, a phototransistor as a lighting detection sensor PTtr1 is turned OFF, voltage value on the data line D1 becomes voltage E(v). This voltage, that is, the data d1 forwarded to the data line D1 from the first group of lighting detection sensors PTtr1 are read out by a data readout device M for detecting that the first group of lighting lamps 10a are put out caused by the core failure. when in this way a scanning device S switches the switches Tr1 to Tr4 in order, the positions of the lighting lamps put out caused by the core failure corresponding to the first to fourth groups become clear from the relation of timing between the data d1 to d4 due to a difference of voltage value on each line of the data lines D1 to D3 and the timing of the scanning signals S1 to S4 to be impressed on the address lines A1 to A4. |
