DISPLAY DEVICE AND ELECTRONIC DEVICE

• US 20140362317A1
• Filed: 05/29/2014
• Published: 12/11/2014
• Est. Priority Date: 06/05/2013
• Status: Abandoned Application

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: KUBOTA, Daisuke, KUBOTA, Yusuke
• Application Number:
  US14/290,258
• Publication Number:
  US 20140362317A1
• Time in Patent Office: Days
• US Class Current: 349/39
• CPC Class Codes: G02F 1/133707 Structures for producing distorted electric fields, e.g. bumps, protrusions, recesses, slits in pixel electrodes
• CPC Class Codes: G02F 1/13394 spacers regularly patterned on the cell subtrate, e.g. walls, pillars G02F1/133377 takes precedence
• CPC Class Codes: G02F 1/136213 Storage capacitors associated with the pixel electrode

Abstract

A display device having less defective alignment is provided. A display device having a high aperture ratio and including a capacitor which can increase charge capacity is also provided. A display device having a high aperture ratio, including a capacitor with large charge capacity, and having less defective alignment is also provided. A display device includes a pixel in a region defined by a scan line, a data line, and a capacitor line. The pixel includes a liquid crystal layer between a counter electrode and a pixel electrode, a spacer in the liquid crystal layer, and a transistor connected to the pixel electrode. The pixel electrode has a depressed portion, and alignment in the liquid crystal layer is controlled by the depressed portion and the spacer.

Claims

1. A display device comprising a plurality of pixels arranged in matrix, each pixel comprising:

a conductive layer having a light-transmitting property;

a first insulating layer over the conductive layer;

a pixel electrode over the first insulating layer, the pixel electrode having a depressed portion;

a counter electrode facing the pixel electrode;

a liquid crystal layer between the pixel electrode and the counter electrode; and

a spacer in the liquid crystal layer and between the pixel electrode and the counter electrode;

wherein the depressed portion overlaps with the conductive layer, and

wherein alignment in the liquid crystal layer is controlled by the depressed portion and the spacer.

2. The display device according to claim 1, further comprising a second insulating layer having an opening over the conductive layer,

wherein the first insulating layer and the pixel electrode are over the second insulating layer, and

wherein the depressed portion is provided along the opening.

3. The display device according to claim 1, wherein the spacer and the depressed portion do not overlap with each other.

4. The display device according to claim 1, further comprising a pair of alignment films facing each other with the liquid crystal layer provided therebetween.

5. An electronic device comprising the display device according to claim 1.

6. A display device comprising a plurality of pixels arranged in matrix, each pixel comprising:

a pixel electrode having a depressed portion;

a counter electrode facing the pixel electrode;

a liquid crystal layer between the pixel electrode and the counter electrode;

a spacer in the liquid crystal layer and between the pixel electrode and the counter electrode;

a transistor electrically connected to the pixel electrode, the transistor comprising a channel formation region in an oxide semiconductor layer; and

a capacitor comprising;

a conductive layer having a light-transmitting property; and

the pixel electrode,

wherein the conductive layer and the depressed portion overlap with each other,

wherein the oxide semiconductor layer and the conductive layer are provided over a same surface and include a same material, and

wherein alignment in the liquid crystal layer is controlled by the depressed portion and the spacer.

7. The display device according to claim 6, further comprising an insulating layer over the transistor, the insulating layer having an opening,

wherein the depressed portion is provided along the opening.

8. The display device according to claim 6, wherein the spacer and the depressed portion do not overlap with each other.

9. The display device according to claim 6, further comprising a pair of alignment films facing each other with the liquid crystal layer provided therebetween.

10. The display device according to claim 6, further comprising a capacitor line between one pixel and another pixel, the capacitor line electrically connected to the capacitor of the one pixel and the capacitor of the other pixel,

wherein the conductive layer of the one pixel and the conductive layer of the other pixel are one same conductive layer,

wherein the one same conductive layer includes:

a first region serving as one electrode of the capacitor of the one pixel;

a second region overlapping with the capacitor line; and

a third region serving as one electrode of the capacitor of the other pixel, and

wherein the second region is between the first region and the third region.

11. The display device according to claim 10, wherein the capacitor of the one pixel and the capacitor of the other pixel are located symmetrically with respect to the capacitor line.

12. An electronic device comprising the display device according to claim 6.

13. A display device comprising:

a first pixel comprising;

a first pixel electrode;

a first counter electrode;

a first liquid crystal layer between the first pixel electrode and the first counter electrode;

a first spacer in the first liquid crystal layer and between the first pixel electrode and the first counter electrode; and

a first transistor electrically connected to the first pixel electrode;

a second pixel comprising;

a second pixel electrode;

a second counter electrode;

a second liquid crystal layer between the second pixel electrode and the second counter electrode;

a second spacer in the second liquid crystal layer and between the second pixel electrode and the second counter electrode; and

a second transistor electrically connected to the second pixel electrode;

a capacitor line between the first pixel and the second pixel; and

an insulating layer over the first transistor and the second transistor, the insulating layer having an opening,

wherein the first pixel electrode and the second pixel electrode are provided over the insulating layer and partly overlap with the opening,

wherein the first pixel electrode includes a first depressed portion along the opening, and

wherein the second pixel electrode includes a second depressed portion along the opening.

14. The display device according to claim 13,

wherein the first spacer and the first depressed portion do not overlap with each other, and

wherein the second spacer and the second depressed portion do not overlap with each other.

15. The display device according to claim 13, further comprising a pair of alignment films facing each other with the first liquid crystal layer and the second liquid crystal layer provided therebetween.

16. The display device according to claim 13,

wherein alignment in the first liquid crystal layer is controlled by the first depressed portion and the first spacer, and

wherein alignment in the second liquid crystal layer is controlled by the second depressed portion and the second spacer.

17. The display device according to claim 13,

wherein the first pixel comprises a first capacitor comprising:

the first pixel electrode; and

a conductive layer having a light-transmitting property,

wherein the second pixel comprises a second capacitor comprising;

the second pixel electrode; and

the conductive layer having a light-transmitting property,

wherein the conductive layer includes a first region overlapping with the capacitor line, and

wherein the opening includes a second region overlapping with the first region.

18. The display device according to claim 17, wherein the first capacitor and the second capacitor are located symmetrically with respect to the capacitor line.

19. The display device according to claim 17,

wherein the first transistor and the second transistor each comprise a channel formation region in an oxide semiconductor layer, and

wherein the oxide semiconductor layer and the conductive layer are provided over a same surface and include a same material.

20. An electronic device comprising the display device according to claim 13.