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EP0555100A1 Expired / Lapsed EP ⏱️ 0.0 years remaining

An active matrix liquid crystal display

Assignee: Sharp Corp
•
Filing: 1993-02-08
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Granted: —
•
Expires: 2013-02-08
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Abstract

Abstract A parasitic capacitance is not caused between a shielding film (210, 224) and a gate line (201) and between a pixel electrode (214) and the gate line (201) in a liquid crystal display of the present invention because the shielding film (210, 224) and the pixel electrode (214) do not overlap the gate lines (201). The display characteristics are thus improved. Furthermore, since the counter shielding film (219) is formed so as to cover a smaller gap of one between the shielding film (210, 224) and the gate line (201) and one between the (201) and pixel electrode (214), light leak through the gap can be blocked. The shielding film (219) can be small because it only covers the gap, thereby preventing a degradation of an aperture ratio. Moreover, a degradation of yield caused by increasing a number of production steps is also prevented because the production steps are not complicated. In another aspect of the liquid crystal display of the present invention, since the gate line (201) is electrically connected to a counter electrode (219), a part of the parasitic capacitance caused between the pixel electrode (214) and the shielding film (210, 224) and between the pixel electrode (214) and the gate line (201) is connected in parallel to a capacitance of liquid crystal (216) and used as a storage capacitance. As a result, the parasitic capacitance less influences on the display characteristics, which is thus further improved. Further, since storage capacitance lines are not required, the aperture rate is not degraded and a degradation of yield caused by increasing a number of the production steps is prevented.

Inventors

  • 👤 Kenichi Ishiguro
  • 👤 Hirohisa Tanaka

Bibliographic Details

Application Number —
Jurisdiction EP
Data Source google_patents
Last Synchronized 2026-11-08 00:31
CPC Classifications
G; G02; G02F; G02F1/00; G02F1/01; G02F1/13; G02F1/133; G02F1/136; G02F1/1362; G02F1/136209; G02F1/136286; G02F1/1368; G02F1/1333; G02F1/1335; G02F1/133509; G02F1/133512; G02F1/136213; G02F1/136218; G02F2201/00; G02F2201/40

Claims Analysis

Total Claims: 17
Claim 1
Independent Claim 137 words
An active matrix liquid crystal display comprising : an active matrix substrate having: a plurality of parallel scanning lines; a plurality of parallel signal lines crossing the scanning lines; pixel electrodes respectively formed in substrate portions defined by two adjacent scanning lines and two adjacent signal lines; switching elements each of which is connected to a corresponding pixel electrode, a corresponding scanning line and a corresponding signal line; and pairs of first shielding films, each pair being provided along both sides of each scanning line, for blocking light leak along the scanning lines; a counter substrate opposed to the active matrix substrate having: a counter electrode; and second shielding films for blocking light leak which is not blocked by the first shielding films; and a liquid crystal layer between the active matrix substrate and the counter substrate.
Claim 2
Dependent Claim 21 words
An active matrix liquid crystal display according to claim 1, wherein none of the first shielding films overlay the scanning lines.
Claim 3
Dependent Claim 46 words
An active matrix liquid crystal display according to claim 2, wherein the second shielding film covers the smaller one of: (1) gaps between the pair of first shielding films and the scanning line sandwiched thereby; and (2) gaps between the pixel electrode and the scanning line.
Claim 4
Dependent Claim 37 words
An active matrix liquid crystal display according to Claim 1, wherein the switching elements are thin film transistors, and a drain in each thin film transistor also serves as one of the pair of first shielding films.
Claim 5
Dependent Claim 28 words
An active matrix liquid crystal display according to claim 1, wherein the signal lines are made from a type of material as used for the first shielding films.
Claim 6
Dependent Claim 125 words
An active matrix liquid crystal display comprising: an active matrix substrate having: a plurality of parallel scanning lines; a plurality of parallel signal lines crossing the scanning lines; pixel electrodes respectively formed in substrate portions defined by two adjacent scanning lines and two adjacent signal lines; switching elements each of which is connected to a corresponding pixel electrode, a corresponding scanning line and a corresponding signal line; and first shielding films each of which is formed so as to overlay an adjacent pixel electrode for blocking light leak along the scanning lines; a counter substrate opposed to the active matrix substrate having a counter electrode electrically connected to the scanning lines; and a liquid crystal layer between the active matrix substrate and the counter substrate.
Claim 7
Dependent Claim 25 words
An active matrix liquid crystal display according to claim 6 further comprising second shielding films respectively opposed to the shielding films across the scanning lines.
Claim 8
Dependent Claim 33 words
An active matrix liquid crystal display according to claim 7, wherein the switching elements are thin film transistors, and a drain in each thin film transistor also serves as the second shielding film.
Claim 9
Dependent Claim 31 words
An active matrix liquid crystal display according to claim 8, wherein the first shielding film and the second shielding film overlaying the same pixel electrode are electrically connected to each other.
Claim 10
Dependent Claim 25 words
An active matrix liquid crystal display according to claim 9 further comprising connecting means for connecting the first shielding film and the second shielding film.
Claim 11
Dependent Claim 21 words
An active matrix liquid crystal display according to claim 10, wherein the connecting means is made from a transparent conductive film.
Claim 12
Dependent Claim 22 words
An active matrix liquid crystal display according to claim 9, wherein the first shielding film and the second shielding film are integrated.
Claim 13
Dependent Claim 28 words
An active matrix liquid crystal display according to claim 6, wherein the signal lines are made from a type of material as used for the first shielding films.
Claim 14
Dependent Claim 31 words
An active matrix liquid crystal display according to claim 7, wherein the signal lines, the first shielding films and the second shielding films are made from the same type of material.
Claim 15
Dependent Claim 56 words
An active matrix liquid crystal display according to claim 7, wherein none of the second shielding films overlay the scanning lines, and the counter substrate comprises third shielding films covering the smaller one of: (1) gaps between the second shielding film and the scanning line; and (2) gaps between the pixel electrode and the scanning line.
Claim 16
Dependent Claim 33 words
An active matrix liquid crystal display according to claim 15, wherein the switching elements are thin film transistors, and a drain in each thin film transistor also serves as the second shielding film.
Claim 17
Dependent Claim 31 words
An active matrix liquid crystal display according to claim 16, wherein the first shielding film and the second shielding film overlaying the same pixel electrode are electrically connected to each other.

References Cited (Backward Citations)

EP0317063A2 Cited

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