摘要 |
A circuit for controlling illumination means in a display includes illumination means arranged in a series-connection that are supplied with an essentially constant current. For individually controlling the illumination means, switches are provided for bypassing individual illumination means, maintaining the essentially constant current in the series-connection. The switches are floating with respect to a ground potential. A coupling means is thus provided for proper control of the switches. In a development of the invention a floating local power supply is provided with each illumination means and switch for operating the switch. The local power supply is, in one embodiment, powered by the control signal that is used for controlling the bypass switch. In another embodiment provision is made for supplying power to the floating local power supply. A driving method according to the embodiments of the circuit is also described. |