LCD device having a smaller level difference
View Patent ↗The TFT substrate of an LCD device has an array of pixel electrodes defined by a plurality of signal lines and a plurality of scanning lines. Each terminal of the scanning lines includes a first metallic pattern, a second metallic pattern in contact with the first metallic pattern through a first via hole, and an ITO pattern in contact with the second metallic pattern through a second via hole. The ITO pattern has a width smaller than the width of the first via hole and larger than the second via hole, thereby providing the TFT substrate with a smaller level difference. The smaller level difference prevents the dust generated during a rubbing treatment from attaching onto the TFT substrate.
1. A liquid crystal display (LCD) device comprising an active-matrix substrate and a counter substrate sandwiching therebetween a liquid crystal (LC) layer, said active-matrix substrate comprising:
a transparent insulator substrate;
a plurality of signal lines extending parallel to one another on said transparent substrate;
a plurality of scanning lines extending parallel to one another and perpendicular to said signal lines;
a plurality of pixel electrodes arranged in vicinities of intersections between said signal lines and said scanning lines;
a plurality of terminals connected to said signal lines and said scanning lines, and an orientation film overlying said pixel electrodes, at least one of said terminals having a layer structure including a first metallic film pattern formed on said transparent insulator substrate;
a first dielectric film having a first via hole, said first dielectric film formed on said first metallic film pattern;
a second dielectric film having a second via hole; and
a transparent conductive film pattern electrically connected with said first metallic film pattern through first and second via holes of said first and second dielectric films,
wherein said second hole overlies said first hole and has a periphery different from that of said first hole, said transparent conductive film pattern having a central area and a peripheral edge; and
wherein at least a first portion of said peripheral edge is located inside of said first via hole, and a second portion of said peripheral edge is located outside of said second via hole as viewed perpendicular to said active-matrix substrate.
2. The LCD device according to claim 1 , wherein said at least one of said terminals includes a second metallic film pattern disposed between said first metallic film pattern and said transparent conductive film pattern, said second metallic pattern being in contact with said first metallic pattern through said first via hole and with said transparent conductive film through said second via hole.
3. The LCD device according to claim 1 , wherein said transparent conductive film pattern has a center substantially aligned with a center of said first via hole.
4. The LCD device according to claim 1 , wherein said transparent conductive film pattern has a center deviated from a center of said first via hole.
5. The LCD device according to claim 4 , wherein said transparent conductive film pattern has another portion protruding from or aligned with a periphery of said first via hole.
6. The LCD device according to claim 5 , wherein said terminal has a surface having a smaller level difference near a leading edge of said transparent conductive film than near a trailing edge thereof as viewed in a rubbing treatment of said orientation film.
7. The LCD device according to claim 4 , wherein said center of said transparent conductive film pattern is deviated from said center of said first via hole in a rubbing direction of said orientation film.
8. The LCD device according to claim 7 , wherein said second via hole is deviated from said first via hole in said rubbing direction.