Liquid crystal display having additional capacitors formed from pixel electrodes and a method for manufacturing the same

A liquid crystal display comprising:

• a front glass substrate having an inner surface and an outer surface;
• a rear glass substrate having an inner surface and an outer surface, said rear glass substrate being in parallel with said front glass substrate and being separated therefrom by a predetermined distance, said inner surface of said rear glass substrate opposing said inner surface of said front glass substrate;
• a plurality of scanning signal lines and a plurality of display signal lines intersecting said plurality of scanning signal lines, arranged on said inner surface of said rear glass substrate in a matrix defining a plurality of pixel areas each bounded by a pair of said plurality of scanning signal lines and a pair of said plurality of display signal lines;
• a plurality of pixel electrodes corresponding respectively to said plurality of pixel areas;
• a plurality of switching devices corresponding respectively to said plurality of pixel areas, each of said plurality of switching devices being connected to a corresponding one of said plurality of display signal lines and a corresponding one of said plurality of pixel electrodes;
• a plurality of first electrodes forming a plurality of additional capacitance type capacitors respectively within each of said plurality of pixel areas;
• a plurality of second electrodes arranged respectively within said plurality of pixel areas and oppositely enclosing a corresponding one of said plurality of pixel electrodes to form a respective one of a plurality of storage type capacitors in conjunction with said corresponding one of said plurality of pixel electrodes, said plurality of second electrodes being driven independently from said plurality of scanning signal lines and said plurality of display signal lines;
• a plurality of wiring connecting portions connecting said plurality of second electrodes of adjacent ones of said plurality of pixel areas;
• a light-shielding matrix layer on said inner surface of said front glass substrate aligned with said plurality of pixel areas, said light-shielding matrix layer defining a plurality of light-transmitting aperture areas therein;
• a color filter layer on said inner surface of said front glass substrate and including a plurality of light transmitting areas respectively covering said plurality of light-transmitting aperture areas and said light-shielding matrix layer;
• a transparent electrode formed on said color filter layer;
• and
• a liquid crystal layer between said front glass substrate and said rear glass substrate;
• at least one of said plurality of first electrodes or said plurality of second electrodes being ring-shaped.

A method for manufacturing a liquid crystal display having a transparent substrate, a plurality of scanning signal lines intersecting a plurality of display signal lines and forming a matrix configuration on a surface of said transparent substrate defining a plurality of pixel regions each bounded by a pair of said plurality of scanning signal lines and a pair of said plurality of display signal lines, a plurality of pixel electrodes corresponding respectively to said plurality of pixel regions, a plurality of switching devices corresponding respectively to said plurality of pixel regions, and a plurality of electrodes respectively within said plurality of pixel regions, said plurality of electrodes being independent from said plurality of scanning signal lines and said plurality of display signal lines, said method comprising steps of:

• forming a first metal layer on a transparent substrate;
• patterning said first metal layer to form bonding pads for connecting inner elements to an outer circuits, to form said plurality of electrodes of a respective plurality of storage capacitance type capacitors in respective ones of said plurality of pixel regions, and to form at least one wiring connecting portion for connecting adjacent ones of said plurality of electrodes;
• forming a second metal layer on the resultant structure having said bonding pads and said plurality of electrodes thereon;
• patterning said second metal layer to form said plurality of scanning signal lines at regular intervals, and to form a plurality of electrodes of a respective plurality of additional capacitance type capacitors respectively within said plurality of pixel regions with an insulating layer therebetween;
• forming an insulating layer on a surface of the resultant structure;
• forming a semiconductor layer on said insulating layer;
• patterning said semiconductor layer to leave only a portion of said semiconductor layer around a portion of said plurality of scanning signal lines;
• forming a transparent conductive layer on a surface of the resultant structure;
• patterning said transparent conductive layer to form said plurality of pixel electrodes respectively opposed to said plurality of electrodes corresponding to said plurality of storage capacitance type capacitor along a periphery thereof;
• forming a third metal layer on the resultant structure;
• and
• patterning said third metal layer to form said plurality of display signal lines regularly arranged and intersecting said plurality of scanning signal lines, and to form respective source and drain electrodes of a thin film transistor on said semiconductor layer.

A liquid crystal display device comprising:

• a transparent substrate;
• a plurality of first scanning signal lines and an intersecting plurality of display signal lines arranged in a matrix configuration on the surface of said transparent substrate, to thereby define a plurality of pixel regions each bounded by a pair of first scanning signal lines and a pair of display signal lines;
• a pixel electrode in each pixel region;
• a switching device in each pixel region and connected with a corresponding display signal line and the pixel electrode of the respective pixel region;
• a first electrode of an additional capacitance type capacitor within each pixel region, for forming an additional capacitance type capacitor in conjunction with the pixel electrode thereof and arranged so as to face a portion of each pixel electrode with an insulating layer interposed therebetween;
• a first electrode of a storage capacitance type capacitor within each pixel region formed by interposing an insulating layer, for forming a storage capacitance type capacitor in conjunction with the pixel electrode thereof and arranged so as to face a portion of each pixel electrode, said first electrodes being independent from said scanning signal lines;
• and
• a first independent wiring connecting said first electrodes of adjacent storage capacitance type capacitors.

A liquid crystal display device comprising:

• a transparent substrate;
• a plurality of first scanning signal lines and display signal lines arranged in a matrix configuration on a surface of said transparent substrate, to thereby define a plurality of pixel regions each bounded by a pair of first scanning signal lines and a pair of display signal lines:
• a pixel electrode in each pixel region;
• a switching device in each pixel region and connected with a corresponding display signal line and the pixel electrode;
• a first electrode of an additional capacitance type capacitor disposed within pixel region so as to face the pixel electrode, for forming an additional capacitor with the pixel electrode with an insulating layer interposed therebetween, said first electrode of said additional capacitance type capacitor being formed in a ring shape which surround the peripheral region of said pixel electrodes;
• at least one redundancy connection portion for connecting said first electrodes of the additional capacitance type capacitors of adjacent pixel regions;
• a first electrode of a storage capacitance type capacitor disposed within said pixel region so as to face the pixel electrode with an insulating layer disposed therebetween, for forming storage capacitor with the pixel electrode, said first electrode being independent from said scanning signal lines, said first electrode of the storage capacitance type capacitor being formed in a ring shape which surrounds the peripheral region of said pixel electrode, said first electrode of said storage capacitance type capacitor being formed between the corresponding scanning signal line and said first electrode of the additional capacitance;
• a first independent wiring connecting said first electrodes of the storage capacitance type capacitors of adjacent pixel regions;
• and
• a second independent wiring for connecting said first electrodes of the storage capacitance type capacitors of adjacent pixel regions.

A liquid crystal display comprising:

• a front glass substrate having inner and outer surfaces;
• a rear glass substrate having inner and outer surfaces, paralleling said front glass substrate and separated therefrom by a predetermined distance to allow its inner surface to oppose said inner surface of said front glass substrate;
• a plurality of scanning signal lines and display signal lines arranged on said inner surface of said rear glass substrate as matrixes for defining a plurality of pixel areas each bounded by means of a pair of said scanning signal lines and a pair of said display signal lines;
• a pixel electrode within said pixel area;
• a switching device within said pixel area for connecting a corresponding display signal line to said pixel electrode;
• a first electrode of an additional capacitance type capacitor disposed within said pixel region so as to face a portion of the pixel electrode with an insulating layer interposed therebetween, for forming an additional capacitance type capacitor;
• a first electrode of a storage capacitance type capacitor disposed within said pixel region so as to face a portion of the pixel electrode with an insulating layer interposed therebetween, for forming a storage capacitance type capacitor with the pixel electrode, said first electrode being independent from said scanning signal lines;
• a light-shielding layer matrix formed on said inner surface of said front glass substrate and aligned with each pixel area for defining a light-transmitting aperture area;
• a color filter layer on said inner surface of said front glass substrate and including a light transmitting area covering said light-transmitting aperture area and said light-shielding layer;
• a transparent electrode formed on said color filter layer;
• and
• a liquid crystal layer between said front and rear glass substrate.

A method for manufacturing a liquid crystal display having a liquid crystal display having a transparent substrate;

• a plurality of scanning signal lines and intersecting display signal lines arranged in a matrix configuration on a surface of said transparent substrate to thereby define a plurality of pixel regions each bounded by a pair of scanning signal lines and a pair of display signal lines;
• a pixel electrode in each pixel region;
• a switching device in each pixel region;
• and a first electrode of a storage type capacitor within each pixel region being independent from the scanning signal lines and the display signal lines, said method comprising the steps of:
• forming a first metal layer on said transparent substrate;
• patterning said first metal layer to form bonding pads for connecting inner elements to an outer circuit;
• forming a second metal layer on the resultant structure having the bonding pads thereon;
• patterning said second metal layer to form said scanning signal lines in a regular arrangement, a first electrode of additional capacitance type capacitor within said pixel region so as to face a portion of the pixel electrode, for forming an additional capacitance type capacitor with an insulating layer interposed therebetween and said first electrode of the storage capacitance type capacitor disposed within said pixel region so as to face a portion of said pixel electrode, for forming storage capacitors with the pixel electrodes with said insulating layer interposed therebetween;
• successively forming an insulating layer and a semiconductor layer on the surface of the resultant structure;
• patterning said semiconductor layer to leave the semiconductor layer only around a portion of said scanning signal lines;
• forming a transparent conductive layer on the surface of the resultant structure;
• patterning said transparent conductive layer to form said pixel electrode to oppose to said first electrode of said storage capacitor along a periphery thereof;
• and
• forming a third metal layer on the resultant;
• patterning said third metal layer to form said plurality of display signal lines regularly arranged while intersecting said scanning signal lines, and source and drain electrodes of a thin film transistor on said semiconductor layer.