Display device having light-emitting elements including metals

Patent metadata

Field	Value
Publication number	US-9595573-B2
Application number	US-201615001817-A
Country	US
Kind code	B2
Filing date	Jan 20, 2016
Priority date	Dec 12, 2002
Publication date	Mar 14, 2017
Grant date	Mar 14, 2017

Abstract

A display device includes a plurality of light-emitting elements aligned on a TFT substrate in a formation of a matrix. The plurality of light-emitting elements each have a flat surface portion and including a light-emitting layer, an anode, and a cathode, an insulating layer formed on the TFT substrate and under the light emitting element, and a tilted metal surface provided on a peripheral area surrounding the flat surface portion of the light-emitting element and having a tilt angle with respect to the flat surface portion of the light-emitting element. The tilted metal surface is provided on a surface of a slope of a bank that is provided on the insulation layer, and a width of a cross-section of the bank becomes smaller as the cross section comes farther away from a surface of the TFT substrate. A counter substrate is placed on the TFT substrate.

First claim

The invention claimed is:

1. A display device comprising:
a plurality of light-emitting elements aligned on a TFT substrate in a formation of a matrix, the plurality of light-emitting elements each having a flat surface portion and including an anode, a light-emitting layer arranged on the anode, and a cathode arranged on the light-emitting layer;
an insulation layer formed on the TFT substrate and under the light emitting element;
a tilted metal which is provided on a peripheral area surrounding the flat surface portion of each of the plurality of light-emitting elements and has a tilt angle against the flat surface portion of each of the plurality of light-emitting elements; and
an optical waveguide layer which is arranged on the cathode and includes a first layer and a second layer on the first layer, a first refraction index of the first layer being larger than a second refraction index of the second layer,
wherein the tilted metal is provided on a surface of a slope of a bank that is provided on the insulation layer,
wherein the bank covers an edge of the anode and has an opening exposing a part of a surface of the anode,
wherein the optical waveguide layer is arranged directly above the part of the surface of the anode,
wherein a width of a cross section of the bank becomes smaller as the cross section comes farther away from a surface of the TFT substrate,
wherein a sealing film is placed on the plurality of light-emitting elements, the optical waveguide layer, the tilted metal, and the TFT substrate,
wherein the light emitting element emits light in a direction from the TFT substrate to the sealing film, and
wherein a first distance between the TFT substrate and a first top surface of the optical waveguide layer is smaller than a second distance between a second top surface of the bank and the TFT substrate.

2. The display device according to claim 1 , further including:
a predetermined metal between the TFT substrate and the insulation layer; and
an extended metal which is connected to the anode,
wherein a gap exists between the optical waveguide layer and the sealing film,
wherein the display device comprises a plurality of pixels aligned on the TFT substrate in a formation of a matrix,
wherein the tilted metal is connected to the cathode,
wherein the predetermined metal is connected to the extended metal via a contact hole in the insulation layer,
wherein each of the bank and the tilted metal overlaps the extended metal and the contact hole in plan view, and
wherein each of the plurality of pixels includes each of the plurality of light-emitting elements.

3. The display device according to claim 2 , wherein the bank is sandwiched between the tilted metal and the anode in the peripheral area surrounding the flat surface portion of each of the plurality of light-emitting elements, and
wherein the bank is not arranged on the flat surface portion of each of the plurality of light-emitting elements in plan view.

4. The display device according to claim 3 , further comprising:
a plurality of driver elements each connected to each of the plurality of light-emitting elements;
a plurality of capacitor elements each of which is connected to each of the light emitting elements and receives each of a plurality of image signals; and
a plurality of switching elements each of which is connected to each of the capacitor elements and each of the light emitting elements and controls input of each of the plurality of image signals to each of the capacitor elements,
wherein the predetermined metal is connected to the driver element.

5. The display device according to claim 1 , wherein a third refraction index of the cathode is smaller than a first refraction index.

6. The display device according to claim 5 , wherein the optical waveguide layer has a cross sectional formation so that a cross sectional width of the optical waveguide layer becomes wider as a distance from the surface of the TFT substrate increases, and
wherein a height of the tilted metal from the flat surface of the light-emitting layer is larger than a maximum height of the optical waveguide layer.

7. The display device according to claim 1 , wherein the sealing film includes a plurality of inorganic layers and a resin layer.

8. A display device including:
a plurality of light-emitting elements aligned on a TFT substrate in a formation of a matrix, at least one of the plurality of light-emitting elements having a flat surface portion and including an anode, a light-emitting layer arranged on the anode, and a cathode arranged on the light-emitting layer;
an insulation layer formed on the TFT substrate and under the light emitting element;
a first metal which is provided on a surface of a slope of a first bank that is provided on the insulation layer;
a second metal which is provided on a surface of a slope of a second bank that is provided on the insulation layer;
a predetermined layer which is arranged on the cathode and includes a first layer made of an organic material and a second layer made of an inorganic material on the first layer,
wherein the flat surface portion of the at least one of the plurality of light-emitting elements is arranged between the first metal and the second metal,
wherein the first and second banks cover an edge of the anode and have an opening exposing a part of a surface of the anode,
wherein the predetermined layer is arranged directly above the part of the surface of the anode,
wherein a width of a cross section of each of the first and the second banks becomes smaller as the cross section comes farther away from a surface of the TFT substrate,
wherein a sealing film is placed on the plurality of light-emitting elements, the predetermined layer, the first metal, the second metal, and the TFT substrate,
wherein the light emitting element emits light in a direction from the TFT substrate to the sealing film,
wherein a first distance between the TFT substrate and a first top surface of the predetermined layer being smaller than a second distance between a second top surface of the first bank and the TFT substrate.

9. The display device according to claim 8 , further including:
a predetermined metal between the TFT substrate and the insulation layer, and
an extended metal is connected to the anode,
wherein a gap exists between the predetermined layer and the counter substrate,
wherein at the flat surface portion of the at least one of the plurality of light-emitting elements, the anode is connected to the organic layer, and the organic layer is connected to the cathode,
wherein the first metal and the second metal are connected to the cathode,
wherein the predetermined metal is connected to the extended metal via a contact hole in the insulation layer, and
wherein each of the first bank and the first metal overlaps the extended metal and the contact hole in plan view.

10. The display device according to claim 9 , wherein inactive gas is arranged in the gap.

11. The display device according to claim 9 , wherein the first and the second banks are formed in an integrated manner,
wherein a peripheral metal of the anode as the predetermined metal surrounds the flat surface portion of the at least one of the plurality of light-emitting elements in plan view, and
wherein the first bank is arranged between the first metal and the peripheral metal of the anode, and the second bank is arranged between the second metal and the peripheral metal of the anode.

12. The display device according to claim 11 , further comprising:
a plurality of driver elements each connected to each of the plurality of light-emitting elements;
a plurality of

Assignees

• Japan Display Inc
• Panasonic Liquid Crystal Displ

Inventors

• Adachi Masaya
• Tsuji Kazutaka
• Murakami Hajime
• Nishimura Etsuko

Classifications

• H10K59/8791

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title

• H10K59/878

  comprising reflective means · CPC title

• H10K59/8723

  Vertical spacers, e.g. arranged between the sealing arrangement and the OLED · CPC title

• H10K59/8722

  Peripheral sealing arrangements, e.g. adhesives, sealants · CPC title

• H10K59/80524

  Transparent cathodes, e.g. comprising thin metal layers · CPC title