Organic electro-luminescent display device

• US 20090109148A1
• Filed: 10/28/2008
• Published: 04/30/2009
• Est. Priority Date: 10/30/2007
• Status: Active Grant

• Current Assignee: Samsung Display Company Limited (Samsung Electronics Co. Ltd.)
• Original Assignee: Hitachi Displays Limited (Japan Display Incorporated)
• Inventors: Akimoto, Hajime, Tokuda, Naoki
• Granted Patent: US 8,384,287 B2
• Time in Patent Office: Days
• US Class Current: 345/76
• CPC Class Codes: H10K 59/1216 the pixel elements being capacitors

Abstract

A high-definition organic EL display device which enhances utilization efficiency of a space within a pixel is provided. In an organic EL display device in which pixels each of which is constituted of an organic El element are arranged in a matrix array, the pixel includes a pixel circuit which is configured to control an electric current supplied to the organic El element, the pixel circuit includes a capacitance, and the capacitance is arranged on a boundary of the pixels arranged adjacent to each other in a longitudinal direction of the pixels. Further, one electrode which constitutes the capacitance is used in common by the pixels arranged adjacent to each other in the longitudinal direction, and another electrode which constitutes the capacitance is separated between the pixels arranged adjacent to each other in the longitudinal direction.

Claims

1. An organic EL display device in which pixels each of which is constituted of an organic El element are arranged in a matrix array, wherein

the pixel includes a pixel circuit which is configured to control an electric current supplied to the organic El element,

the pixel circuit includes a capacitance, and

the capacitance is arranged on a boundary of the pixels arranged adjacent to each other in a longitudinal direction of the pixels.

2. An organic EL display device according to claim 1, wherein one electrode which constitutes the capacitance is continuously formed between the pixels arranged adjacent to each other in the longitudinal direction of the pixels, and

another electrode which constitutes the capacitance is separately formed between the pixels arranged adjacent to each other in the longitudinal direction of the pixels.

3. An organic EL display device according to claim 1, wherein one electrode which constitutes the capacitance is formed of a silicon film doped with phosphorous with higher concentration than a channel layer.

4. An organic EL display device according to claim 1, wherein one electrode which constitutes the capacitance is connected to a video signal line via one contact hole.

5. An organic EL display device according to claim 1, wherein one electrode which constitutes the capacitance is separated from the pixel arranged adjacent to the pixel in the lateral direction of the pixels.

6. An organic EL display device according to claim 1, wherein the pixel circuits arranged in the pixels are arranged in line symmetry with respect to the boundary of the pixels for every pixel in the longitudinal direction of the pixel.

7. An organic EL display device according to claim 1, wherein the pixel circuits arranged in the pixels are arranged in line symmetry with respect to the boundary of the pixels for every pixel in the lateral direction of the pixel.

8. An organic EL display device comprising:

a plurality of pixels each of which is constituted of an organic EL element;

power source lines which are configured to supply an electric current to the organic EL elements; and

video signal lines which are configured to supply video signals to the pixels, wherein

the pixel includes;

a transistor which is connected between the power source line and the organic EL element; and

a capacitance which is connected between the transistor and the video signal line, and

a contact hole is formed at a position adjacent to a portion of the power source line where a line width is narrowed.

9. An organic EL display device according to claim 8, wherein the power source line is sandwiched between the contact holes arranged adjacent to each other.