Liquid crystal display device, voltage setting method for liquid crystal display device and method for producing liquid crystal display device

A liquid crystal display device comprising:

• a liquid crystal display panel including a plurality of pixels, the liquid crystal display panel including an active matrix substrate, a counter substrate opposing the active matrix substrate, and a liquid crystal layer disposed between the active matrix substrate and the counter substrate;
• and
• a control circuit configured to generate source signal voltages supplied to respective pixels of the plurality of pixels in response to receiving input display signals indicating gradation levels to be displayed by the respective pixels of the plurality of pixels,
• the active matrix substrate including pixel electrodes which are provided in the respective pixels of the plurality of pixels and to which the source signal voltages are applied, and a common electrode to which a common voltage is applied to generate, together with the pixel electrodes, in-plane electric fields,
• wherein when a source-common center difference is defined by a difference between a center level of each source signal voltage and a center level of the common voltage,
• the common voltage and the source signal voltage corresponding to each gradation level are set such that the source-common center difference at least at one of a lowest gradation level and a highest gradation level is greater than the source-common center difference at least at part of the other gradation levels,
• and wherein when Vp denotes an absolute value of a positive polarity potential of each source signal voltage and Vn denotes an absolute value of a negative polarity potential of each source signal voltage,
• and a degree of symmetry of a gradation level voltage at each gradation level is defined such that when a relationship Vp>Vn is satisfied for Vp and Vn of the source signal voltage at a 127/255-th gradation level, the degree of symmetry is given by (Vn/Vp)−100[%] while when a relationship Vp<Vn is satisfied for Vp and Vn of the source signal voltage at the 127/255-th gradation level,
• the degree of symmetry is given by (Vp/Vn)−100[%], the degree of symmetry of the gradation level voltage is equal to or smaller than 95% at least at one of gradation levels equal to or lower than the 127/255-th gradation level.