Liquid crystal display device

• US 20030103181A1
• Filed: 10/31/2002
• Published: 06/05/2003
• Est. Priority Date: 12/03/2001
• Status: Active Grant

• Current Assignee: Panasonic Liquid Crystal Display Company Limited (Panasonic Holdings Corporation)
• Original Assignee: Hitachi, Ltd.
• Inventors: Ono, Kikuo, Oke, Ryutaro, Ochiai, Takahiro, Imayama, Hirotaka
• Granted Patent: US 6,819,389 B2
• Time in Patent Office: Days
• US Class Current: 349/122
• CPC Class Codes: G02F 1/133345 Insulating layers G02F1/1335, G02F1/1337, G02F1/135, G02F1/136 take precedence
• CPC Class Codes: G02F 1/1339 Gaskets; Spacers; Sealing of cells
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/13456 Cell terminals located on one side of the display only

Abstract

There is provided a TFT liquid crystal display device in which the adhesion strength of a sealing material is high and the reliability of its terminals is high. In a peripheral area of the liquid crystal display device, an organic protective film underlying the area of the sealing material is collectively removed together with an inorganic protective film, and video signals are respectively led from drain lines of a display area in such a manner that the respective drain lines are temporarily connected to gate lines underlying an insulating film under the sealing material.

Claims

1. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines;

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions; and

alignment films formed on at least surfaces of the respective first and second substrates, which surfaces are closest to the liquid crystal layer,

the first substrate having an organic film formed between each of the thin film transistors and the alignment film formed on the first substrate, the organic film being removed in an area of the sealing material, the sealing material being adhered to an inorganic film on the first substrate and to an organic film on the second substrate.

2. An active matrix type liquid crystal display device according to claim 1, wherein a protective film of each of the thin film transistors is a stacked film made of an inorganic film formed of SiN and a photosensitive organic material, the stacked film made of the inorganic film and the photosensitive organic film having openings worked through one exposure cycle during formation of contact holes.

3. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines; and

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions,

wherein each of the drain lines is connected to a metal material formed in the same process as the gate lines on a display-area side of the sealing material, is led under the sealing material as a metal material layer formed in the same process as the gate lines, and in an external-connection-terminal-side area outside the sealing material, is led from the metal material layer formed in the same process as the gate lines and is connected to an external connection terminal via a metal material layer formed in the same process as the drain lines.

4. An active matrix type liquid crystal display device according to claim 3, wherein an organic film formed as a protective film for the thin film transistor has an opening in an area under the sealing material in which each of the drain lines is led as the metal material layer formed in the same process as the gate lines, the sealing material in the area being adhered to an inorganic insulating film.

5. An active matrix type liquid crystal display device according to claim 3, wherein a protective film for the thin film transistor is a stacked film made of an inorganic film formed of SiN and a photosensitive organic material, the stacked film made of the inorganic film and the photosensitive organic film having openings worked through one exposure cycle during formation of contact holes.

6. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines;

alignment films formed on at least surfaces of the respective first and second substrates, which surfaces are closest to the liquid crystal layer;

polarizers respectively disposed on surfaces of the first substrate and the second substrate on sides opposite to the liquid crystal layer; and

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions,

wherein each pixel in a pixel area defined as an aggregation of pixels has a pixel electrode and a common electrode on the first substrate and the liquid crystal layer is driven by an electric field being generated between the pixel electrode and the common electrode and having a component parallel to the first substrate, a transparent electrode wider than at least each of the pixels being formed in an area between the pixel area and the sealing material on the first substrate, the respective alignment films having areas formed on the first substrate and the second substrate and positioned in an area in which the transparent electrode is formed, the respective polarizers having areas positioned and provided in the area in which the alignment films are formed, the polarizers, the liquid crystal layer and the alignment films being arranged to realize a normally black mode.

7. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines;

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions; and

column-shaped spacers which determine a gap between the first substrate and the second substrate,

each of the column-shaped spacers having at least two areas having different thicknesses in an area between a pixel area defined as an aggregation of pixels and the sealing material, at least one of the at least two areas having a height which determines the gap between the first substrate and the second substrate, another of the at least two areas being formed to be thinner than the at least one, the column-shaped spacers being made of a material which exhibits a light shielding effect.

8. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines; and

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions,

wherein the color filter layer is formed on the first substrate and has a line superposition area in which a material of each of the drain lines and a material of each of the gate lines are formed with the end portions of the respective materials superposed on each other with an interlayer insulting film interposed therebetween in a portion between a pixel area defined as an aggregation of pixels and a terminal area, at least one layer of the color filter layer being formed in the line superposition area.

9. An active matrix type liquid crystal display device comprising:

a liquid crystal layer and a color filter layer interposed between a first substrate and a second substrate;

a plurality of gate lines formed on the first substrate;

a plurality of drain lines disposed on the first substrate in matrix form to intersect the plurality of gate lines;

thin film transistors formed on the first substrate and respectively disposed to correspond to intersections of the gate lines and the drain lines; and

a sealing material which causes the first substrate and the second substrate to adhere to each other along their peripheral portions,

the sealing material being adhered to an organic material of the first substrate and to an inorganic material of the second substrate.

10. An active matrix type liquid crystal display device according to claim 9, wherein the inorganic material of the second substrate to which the sealing material is adhered is the second substrate itself.