Patent ID: 6366063
Filing Date: 2002-04-02
Classification: G05F,G09G

Abstract:
A driving circuit for a capacitive load, which supplies a pulse to the capacitive load that is an electrode of a capacitive display panel, the driving circuit comprising:a coil connected in series directly or indirectly to the capacitive load and making up a serial resonance circuit together with the capacitive load; a first switch for applying a DC power source voltage output from a DC power source to the serial resonance circuit and causing first resonance to begin by closing the first switch; a first clamping circuit for stopping the first resonance by clamping a voltage of the capacitive load at the DC power source voltage at time at which the voltage of the capacitive load begins to exceed the DC power source voltage after the first resonance starts; a first flywheel current control circuit for bringing a current flowing through the coil into a first flywheel operational state and sustaining it when the first resonance stops; a first electric-current regenerating circuit for regenerating the current in the first flywheel operational state to the DC power source; a second switch for causing the serial resonance circuit to begin second resonance, with a charging voltage of the capacitive load as a source, by closing the second switch; a second clamping circuit for clamping the voltage of the capacitive load at the earth potential and stopping the second resonance at the time at which the voltage of the capacitive load begins to fall below the earth potential after the second resonance begins; a second flywheel current control circuit for bringing the current flowing through the coil into a second flywheel operational state and sustaining it when the second resonance stops; and a second electric-current regenerating circuit for regenerating the current of the second flywheel operational state to the DC power source.