Display device, display module, and electronic device

Patent metadata

Field	Value
Publication number	US-11733574-B2
Application number	US-201816956623-A
Country	US
Kind code	B2
Filing date	Dec 25, 2018
Priority date	Jan 5, 2018
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A liquid crystal display device with a high aperture ratio is provided. The display device includes a transistor, a first insulating layer, a second insulating layer, a third insulating layer, a first conductive layer, a pixel electrode, a common electrode, and a liquid crystal layer in a pixel. The first insulating layer is positioned over a channel formation region of the transistor. The first conductive layer is positioned over the first insulating layer. The second insulating layer is positioned over the transistor, the first insulating layer, and the first conductive layer. The pixel electrode is positioned over the second insulating layer, the third insulating layer is positioned over the pixel electrode, the common electrode is positioned over the third insulating layer, and the liquid crystal layer is positioned over the common electrode. The common electrode includes a region overlapping with the first conductive layer with the pixel electrode positioned therebetween. The pixel includes a first connection portion where the pixel electrode is electrically connected to the transistor and a second connection portion where the first conductive layer is electrically connected to the common electrode. The first conductive layer, the pixel electrode, and the common electrode each have a function of transmitting visible light.

First claim

The invention claimed is:

1. A display device comprising:
a pixel comprising a first transistor comprising a semiconductor layer containing silicon, and a second transistor;
a first insulating layer over a channel formation region of the first transistor;
a first conductive layer over the first insulating layer;
a second insulating layer over the first transistor, the second transistor, the first insulating layer, and the first conductive layer;
a pixel electrode over the second insulating layer;
a third insulating layer over the pixel electrode;
a common electrode over the third insulating layer; and
a liquid crystal layer over the common electrode,
wherein the common electrode comprises a region overlapping with the first conductive layer with the pixel electrode therebetween,
wherein in a first connection portion, the pixel electrode is electrically connected to the first transistor,
wherein in a second connection portion, the first conductive layer is electrically connected to the second transistor,
wherein each of the first conductive layer, the pixel electrode, and the common electrode is configured to transmit visible light, and
wherein the first conductive layer contains one or more kinds selected from indium, zinc, and tin.

2. The display device according to claim 1 , further comprising a second conductive layer over the first insulating layer,
wherein the first conductive layer and the second conductive layer comprise the same material, and
wherein in the first connection portion, the pixel electrode comprises a region in contact with the second conductive layer and the second conductive layer comprises a region in contact with one of a source and a drain of the first transistor.

3. The display device according to claim 1 ,
wherein an area of a region where the pixel electrode and the first conductive layer overlap with each other is larger than an area of a region where the pixel electrode and the common electrode overlap with each other.

4. The display device according to claim 1 ,
wherein a thickness of the second insulating layer between the first conductive layer and the pixel electrode is smaller than a thickness of the third insulating layer between the pixel electrode and the common electrode.

5. A display module comprising:
the display device according to claim 1 ; and
at least one of a connector and an integrated circuit.

6. An electronic device comprising:
the display module according to claim 5 ; and
at least one of an antenna, a battery, a housing, a camera, a speaker, a microphone, and an operation button.

Assignees

• Semiconductor Energy Lab

Inventors

• Toyotaka Kouhei
• Watanabe Kazunori
• Kawashima Susumu
• Takahashi Kei
• Kusunoki Koji
• Nakada Masataka
• Sato Ami

Classifications

• G02F1/136227 Primary

  Through-hole connection of the pixel electrode to the active element through an insulation layer · CPC title

• G02F1/134372

  for fringe field switching [FFS] where the common electrode is not patterned · CPC title

• G02F1/1368 Primary

  in which the switching element is a three-electrode device {(G02F1/136277 takes precedence)} · CPC title

• G02F1/134309

  characterised by their geometrical arrangement · CPC title

• G09F9/35

  being liquid crystals (G09F9/302 takes precedence; liquid crystal materials C09K19/00; {liquid crystal panels comprising a number of electrodes in a single cell per se G02F1/13}) · CPC title