1. Technical Field
The present invention relates to a technology for driving a liquid crystal device in which an electrode (hereinafter, “detection electrode”) is formed to detect a contact of a finger or a pen on the basis of variation in capacitance.
2. Related Art
An existing liquid crystal device that is provided with a capacitance type touch panel has been proposed. A detection electrode is arranged in proximity to the liquid crystal device, so that a capacitor is associated between the detection electrode and elements in the liquid crystal device (for example, electrode or wiring). Thus, there is a problem that noise is generated in the detection electrode because of changes in signals used for image display in the liquid crystal device. Japanese Unexamined Patent Application Publication No. 2006-146895 describes a technology for removing noise due to variation in electric potential of an opposite electrode from a detection signal on the basis of variation in capacitance of the detection electrode.
However, in the technology described in JP-A-2006-146895, a complex circuit is required for removing noise from the detection signal, so that there is a problem that a circuit size increases and manufacturing costs also increase.