Patent ID: 7446833

Claim:
An in-plane switching mode active matrix type liquid crystal display device comprising: a first substrate; a second substrate located opposing said first substrate; and a liquid crystal layer sandwiched between said first and second substrates, wherein said first substrate includes: a thin film transistor having a gate electrode, a drain electrode and a source electrode; a pixel electrode each associated to a pixel to be driven; a common electrode to which a reference voltage is applied; data lines; a scanning line; and common electrode lines, said gate electrode is electrically connected to said scanning line, said drain electrode is electrically connected to said data lines, said source electrode is electrically connected to said pixel electrode, and said common electrode is electrically connected to said common electrode lines, said pixel electrode is in a zigzag form and almost equally spaced away from adjacent ones, said common electrode is in a zigzag form and almost equally spaced away from adjacent ones. two-directional electric fields almost parallel with a surface of said first substrate are applied across said pixel electrode and said common electrode, said in-plane switching mode active matrix type liquid crystal display device includes a first pixel area to which an electric field having a first direction is applied and in which molecular axes of liquid crystal in said liquid crystal layer are rotated in a first rotational direction in a plane parallel with a surface of said first substrate, and a second pixel area to which an electric field having a second direction is applied and in which said molecular axes are rotated in a second rotational direction which is different from said first rotational direction, in a plane parallel with a surface of said first substrate, said common electrode is composed of transparent material, and is formed on a layer located closer to said liquid crystal layer than said data lines, said common electrode entirely overlaps said data lines with an insulating layer being sandwiched therebetween except an area where said data lines are located in the vicinity of said scanning line, said in-plane switching mode active matrix type liquid crystal display device further includes a light-impermeable layer in an area where said common electrode entirely overlaps the data lines, said light-impermeable layer is formed on said second substrate or on said first substrate such that said light-impermeable layer and said liquid crystal layer are located at the same side with respect to said data lines and that said light-impermeable layer faces said data lines, said light-impermeable layer is comprised of a black matrix layer or multi-layered color layers, said black matrix layer or said multi-layered color layers has a width smaller than a width of said common electrode overlapping said data lines, said data lines extend in a zigzag along said pixel electrode, wherein the width of the black matrix layer is narrower than a width of the data lines.