Nec Corporation

Masataka Ohba

Yoshio Sano

A capacitive load drive is provided, which can perform faster and more efficient operation than an energy recovery circuit for effectively reducing ineffective energy of pulses applied to a capacitive load. An energy recovery circuit is connected to a first electrode of the capacitive load, to which pulses are applied. The energy recovery circuit comprises a coil and a capacitor connected in series for energy recovery, and a first and a second voltage clamp switches connected to the other terminal of the series circuit of the coil and the capacitor, the first voltage clamp switch being connected to a high voltage side terminal of the DC power supply, the second voltage clamp switch being connected to a low voltage side terminal of the DC power supply.

Driver for display panel

The plasma display panel driver circuit disclosed includes a panel inter-electrode capacitor, a charging/discharging circuit, and a voltage clamp circuit. The panel inter-electrode capacitor is provided between scanning and sustain electrodes of a panel. The charging/discharging circuit is connected in parallel with the panel inter-electrode capacitor and formed by a combination of a coil, FET switches and reverse current blocking diodes. The voltage clamp circuit includes four switches connected to terminals of the panel inter-electrode capacitor. The panel inter-electrode capacitor, together with a series circuit of the coil and the FET switches, forms a parallel resonance circuit. The panel inter-electrode capacitor 40 is repeatedly charged and discharged through the control of the switches with switch drive inputs. In the driving of a plasma display panel, ineffective power is reduced when charging and discharging the panel inter-electrode capacitor.

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Tokyo, Japan

Masataka Ohba