US 5,771,083 A · Active matrix substrate and liquid crystal display device

Abstract

A liquid crystal display device incorporating an active matrix substrate having an inter-layer insulating film between a pixel electrode and gate and source signal lines. In this liquid crystal display device, the source signal line has a double-layer structure of an upper-layer line and a lower-layer line, but the upper-layer line is eliminated at the intersection of the gate signal line and the source signal line. This structure prevents a decrease in the thickness of the inter-layer insulating layer on the intersection of the gate signal line and the source signal line.

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Claims20

Dependent claims

An active matrix substrate comprising:

a substrate;
and
more than one kind of lines made of an electrically conductive film, said lines being arranged to cross each other on said substrate,
wherein a film thickness of at least one of said lines at an intersection of said lines is thinner than a film thickness thereof at portions other than the intersection;
wherein the electrically conductive film of at least one line is a multi-layer film having a first layer made of ITO and a second layer made of a metal having a lower electrical resistance than ITO, and said second layer is eliminated at the intersection.

2 more elements

An active matrix substrate comprising:

a scanning line and a signal line arranged to cross each other;
a switching element to which a scanning signal and a data signal are supplied by said scanning line and said signal line, respectively;
a pixel electrode driven by said switching element;
an inter-layer insulating film between said pixel electrode and said scanning and signal lines, and having a contact hole through which said switching element is electrically connected to said pixel electrode;
wherein a film thickness of at least one of said scanning line and said signal line at an intersection of said scanning line and said signal line is thinner than a film thickness thereof at portions other than the intersection;
a storage capacitor line parallel with said scanning line and crossing said signal line;
and
an electrically conductive extended section which is extended from a contact section of said switching element and said pixel electrode to a position where said extended section overlaps said storage capacitor line,
wherein a storage capacity is produced between said storage capacitor line and said extended section, and
at least a film thickness of one of said signal line and said storage capacitor line at an intersection of said signal line and said storage capacitor line is thinner than a film thickness thereof at portions other than the intersection.

7 more elements

Dependencies are inferred from the claim text.

Description5,893 words

Summary2,435 words

#This application is related to the following commonly assigned co-pending applications: Ser. No. 08/695,632, filed Aug. 12, 1996; Ser. No. 08/712,978, filed Sep. 12, 1996; Ser. No. 08/700,172, filed Aug. 20, 1996; Ser. No. 08/697,277, filed Aug. 27, 1996; and Ser. No. 08/705,759, filed Aug. 30, 1996; and Ser. No. 08/720,152 filed Sep. 25, 1996.

#The present invention relates to an active matrix substrate having thereon switching elements such as thin film transistors (hereinafter referred to as "TFT"), and also relates to a liquid crystal display device incorporating the active matrix substrate.

#Liquid crystal display devices are now practically used as terminal-oriented display devices, for example liquid crystal televisions, word processors, and personal computers. A known conventional liquid crystal display device is an active matrix type liquid crystal display device. The active matrix type liquid crystal display device is produced by fabricating pixel electrodes in a matrix form and connecting a switching element to each of the pixel electrodes so that the light transmittance of each pixel is independently controlled. A characteristic of the active matrix type liquid crystal display device is its high-contrast, high-quality display.

Brief description of the drawings8 figures

#FIG. 1 is a plan view showing the structure of an active matrix substrate used in a liquid crystal display device according to one embodiment of the present invention.

#FIG. 2 is a sectional view showing a cross section cut along the A--A plane in FIG. 1.

#FIG. 3 is a sectional view showing a cross section cut along the B--B plane in FIG. 1.

Detailed description3,287 words

#The following description will discuss one embodiment of the present invention with reference to FIGS. 1 to 3.

#FIG. 1 is a plan view showing the structure of an active matrix substrate in a liquid crystal display device according to this embodiment. As illustrated in FIG. 1, a gate signal line 2 (scanning line) and a source signal line 3 (signal line) cross at a right angle on the active matrix substrate. A TFT 8 as a switching element is formed in the vicinity of the intersection of the gate signal line 2 and the source signal line 3. In addition, an inter-layer insulating film (not shown) is provided to cover the above-mentioned members. A pixel electrode 5 is arranged on the inter-layer insulating film.

#A gate electrode 2c of the TFT 8 is arranged to protrude from the gate signal line 2. The TFT 8 is driven in a controlled manner by a gate signal input to the gate electrode 2c.

Facts

Application

08/725,663Filed 1 Oct 1996

Priority

JP 7-26730716 Oct 1995

Granted

23 Jun 1998

Term ended

1 Oct 2016

Estimated · how

20 years from earliest known nonprovisional domestic filing. Maintenance-fee lapses, terminal disclaimers and statutory extensions have not been checked. The continuity chain may be incomplete; this is not an enforceability determination. Patent term adjustment is unavailable; no adjustment was added.

Classification2 codes

G02F 1/136286
Active matrix addressed cells: wiring, e.g. gate line, drain line
G02F
Optical devices or arrangements for the control of light by modification of

Description5,893 words

Summary2,435 words

Brief description of the drawings8 figures

#FIG. 1 is a plan view showing the structure of an active matrix substrate used in a liquid crystal display device according to one embodiment of the present invention.

#FIG. 2 is a sectional view showing a cross section cut along the A--A plane in FIG. 1.

#FIG. 3 is a sectional view showing a cross section cut along the B--B plane in FIG. 1.

Detailed description3,287 words

#The following description will discuss one embodiment of the present invention with reference to FIGS. 1 to 3.

#A gate electrode 2c of the TFT 8 is arranged to protrude from the gate signal line 2. The TFT 8 is driven in a controlled manner by a gate signal input to the gate electrode 2c.

Active matrix substrate and liquid crystal display device

Life of this patent

Active matrix substrate and liquid crystal display device

Life of this patent

Life of this patent

Abstract

Drawings

Drawings

Claims20

Description5,893 words

Drawings

Classification2 codes

Life of this patent

Description5,893 words