| 摘要 |
PURPOSE:To control a lot of display functions with a little wiring and CPU ports at the display device provided with the plural display functions such as the board nurse call system of a hospital. CONSTITUTION:The pairs of LED 1a and 1b-4a and 4b arranged respective display units arranged in the shape of a matrix are respectively connected to wires A1, A2, B1 and B2 in a row direction and a column direction, and arbitrary one of plural LED pairs can be turned on by selecting the pair of wires A1, A2, B1 and B2 in the row and column directions and controlling the direction of a current. On the other hand, since the current is alternately supplied to the selected pair of wires while sharing time, the plural LED 1a and 1b-4a and 4b are alternately turned on in a short time while sharing time, and there is the same effect as simultaneously turning on the plural arbitrary LED.
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