| 摘要 |
<p>The invention relates to a display device comprising electrically controlled display elements which are selectively energised by a diode matrix network. The technical problem to be solved is to avoid extensive malfunction due to short-circuiting of a single control diode. In accordance with the invention, each diode for supplying control current in respective directions to a given display element is backed up by a respective second diode connected in series with and in the same direction as the first diode. During maintenance operation, the matrix network is energised with a test voltage sufficiently low for the display elements not to be actuated, the test voltage being several times higher than the forward potential drop across one diode. The invention is especially applicable to display panels placed along motorways.</p> |
