US 6,194,837 B1Granted

Display device with thin film transistor (TFT) and organic semiconductor film in a luminescent element

AssigneeSeiko Epson Corporation

InventorTokuroh Ozawa

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Abstract

The invention provides a display device in which parasitic capacitance associated with data lines and driving circuits is prevented using a bank layer whose primary purpose is to define areas on a substrate in which an organic semiconductor film is formed. When the organic semiconductor film for forming a luminescent element such as an electroluminescent element or an LED is formed is formed in pixel regions (7), the organic semiconductor film is formed in the areas surrounded by the bank layer (bank) formed of a black resist. The bank layer (bank) is also formed between an opposite electrode (op) and data lines (sig) for supplying an image signal to first TFTs (20) and holding capacitors (cap) in the pixel regions (7) thereby preventing parasitic capacitance associated with the data lines (sig).

Claims21

Dependent claims

A display device comprising elements formed on a substrate, said elements including:

a plurality of scanning lines;
a plurality of data lines extending in a direction crossing a direction in which said scanning lines extend;
a plurality of common power supply lines extending in a direction parallel to said data lines;
and
pixel regions formed in the shape of a matrix defined by said data lines and said scanning lines, each of said pixel regions including:
a first thin film transistor having a first gate electrode to which a scanning signal is supplied via one of the scanning lines;
a holding capacitor for holding an image signal supplied from a corresponding data line via said first thin film transistor;
a second thin film transistor having a second gate electrode to which said image signal held by said holding capacitor is supplied;
and
a luminescent element including an organic semiconductor film formed between a pixel electrode provided in each of said pixel regions and an opposite electrode extending across the data lines such that said opposite electrode faces the plurality of pixel electrodes, said luminescent element being adapted to emit light when said organic semiconductor film is driven by a driving current which flows between said pixel electrode and said opposite electrode when said pixel electrode is electrically connected to a corresponding common power supply line via said second thin film transistor,
light emitting areas of said organic semiconductor film being surrounded by a bank layer made up of an insulating film having a thickness greater than that of said organic semiconductor film, said bank layer being formed such that said data lines are, at least partly, covered with said bank layer.

8 more elements

A display device comprising elements formed on a substrate, said elements including:

a plurality of scanning lines;
a plurality of data lines extending in a direction perpendicular to a direction in which said scanning lines extend;
a plurality of common power supply lines extending in a direction parallel to said data lines;
at least one of a first driving circuit for outputting an image signal over said data lines and a second driving circuit for outputting a scanning signal over said scanning lines;
and
pixel regions formed in the shape of a matrix defined by said data lines and said scanning lines, each of said pixel regions including:
a first thin film transistor having a first gate electrode to which the scanning signal is supplied via one of the scanning lines;
a holding capacitor for holding the image signal supplied from a corresponding data line via said first thin film transistor;
a second thin film transistor having a second gate electrode to which said image signal held by said holding capacitor is supplied;
and
a luminescent element including an organic semiconductor film formed between a pixel electrode provided in each of said pixel regions and an opposite electrode extending across the data lines such that said opposite electrode faces the plurality of pixel electrodes, said luminescent element being adapted to emit light when said organic semiconductor film is driven by a driving current which flows between said pixel electrode and said opposite electrode when said pixel electrode is electrically connected to a corresponding common power supply line via said second thin film transistor,
light emitting areas of said organic semiconductor film being surrounded by a bank layer made up of an insulating film having a thickness greater than that of said organic semiconductor film, said bank layer being formed such that said at least one of said driving circuits are covered with said bank layer.

9 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/242,927Filed 26 Feb 1999
Priority: JP 9-1774542 Jul 1997
Granted: 27 Feb 2001
Term ends: Not estimatedThe source records don’t support an estimate.

Classification16 codes

G09G 3/3225
Organic, e.g. using organic light-emitting diodes [OLED]: using an active matrix
H10K 59/122
Active-matrix OLED [AMOLED] displays: pixel-defining structures or layers, e.g. banks
H10K 59/131
Active-matrix OLED [AMOLED] displays: interconnections, e.g. wiring lines or terminals
H10K 59/8792
Arrangements for improving contrast, e.g. preventing reflection of ambient light: comprising light absorbing layers, e.g. black layers