Display device and drive method providing improved signal linearity

摘要

A display device having a pixel section including a plurality of pixel circuits arrayed in a matrix, a plurality of scan lines, a plurality of capacity lines, a plurality of signal lines, a drive circuit, and a generation circuit generating a small amplitude common voltage signal switching in level at a predetermined cycle, wherein each pixel circuit arranged at the pixel section contains a display element having a first pixel electrode and a second pixel electrode and a storage capacitor having a first electrode and a second electrode, the first pixel electrode of the display element, the first electrode of the storage capacitor, and one terminal of the switching element are connected, the second electrode of the storage capacitor is connected to the capacity lines arrayed in a corresponding row, and the common voltage signal is applied in a second pixel electrode of the display element.

主权项

1. A display device comprising:
a pixel section having a plurality of pixel circuits, each writing video pixel data propagated through a switching element, arranged in a matrix, a plurality of scan lines arranged so as to correspond to an array of rows of the pixel circuits and control conduction of the switching elements, a plurality of capacity lines arranged so as to correspond to an array of rows of the pixel circuits, a plurality of signal lines arranged so as to correspond to an array of columns of the pixel circuits and carrying the pixel data, a drive circuit for selectively driving the plurality of scan lines and the plurality of capacity lines, and a generation circuit for generating a common voltage signal switched in level at a predetermined period, wherein each pixel circuit arrayed at the pixel section includes a display element having a first pixel electrode and second pixel electrode, and a storage capacitor having a first electrode and second electrode, a first pixel electrode of the display element, a first electrode of the storage capacitor, and one terminal of the switching element are connected, a second electrode of the storage capacitor is connected to the capacity line arrayed at a corresponding row, and a second pixel electrode of the display element is supplied with the common voltage signal, the drive circuit selectively applies a capacity line driving signal to an intended capacity line, the capacity line driving signal being selected from a first level or a second level, the second level being lower than the first level, (i) an amplitude of the common voltage signal and (ii) a difference between the first level and the second level of the capacity line driving signal are determined so that an effective pixel potential when the display element is a normally white mode liquid crystal cell is compensated for an optimal white display while the effective pixel potential for a black display is maintained as optimal; wherein the effective pixel potential is obtained from a following approximate equation:
ΔVpix=Vsig+(Ccs/(Ccs +Clc))ΔVcs+(Clc/(Ccs +Clc))(ΔVcom/2)−Vcom wherein ΔVpix is the effective pixel potential, Vsig is a video signal voltage, Ccs is a storage capacity, Clc is a liquid crystal capacity, ΔVcs is the difference between the first level and the second level of the capacity line driving signal, and Vcom is the amplitude of the common voltage signal.