Liquid crystal display device with pixel electrodes overlapping a slit between common electrodes

Patent metadata

Field	Value
Publication number	US-10908464-B2
Application number	US-201916375352-A
Country	US
Kind code	B2
Filing date	Apr 4, 2019
Priority date	Apr 25, 2018
Publication date	Feb 2, 2021
Grant date	Feb 2, 2021

Abstract

According to one embodiment, a liquid crystal display device includes scanning and video signal lines, pixel electrodes and first and second common electrodes. The pixel electrodes include first and second pixel electrodes with linear electrodes and connection portion. In the first pixel electrodes, the linear electrodes overlap the first common electrode, and the connection portion overlaps first slit between the first and second common electrodes. In the second pixel electrodes, the linear electrodes overlap the second common electrode, and the connection portion overlaps second slit between the second and first common electrodes. Different potentials are applied to the first and second common electrodes.

First claim

What is claimed is:

1. A liquid crystal display device, comprising:
a first substrate;
a second substrate opposing the first substrate; and
a liquid crystal layer disposed between the first substrate and the second substrate, wherein
the first substrate comprises a plurality of scanning signal lines extending in a first direction, a plurality of video signal lines extending in a second direction intersecting the first direction, a plurality of pixel electrodes electrically connected to the video signal lines, respectively, and a plurality of common electrodes,
the common electrodes include a plurality of first common electrodes and a plurality of second common electrodes separated from the plurality of first common electrodes, which are alternately arranged along the first direction,
the pixel electrodes include a plurality of first pixel electrodes and a plurality of second pixel electrodes that are alternately arranged along the first direction, and each of the first pixel electrodes and each of the second pixel electrodes includes a plurality of linear electrodes extending along the first direction and a connection portion connecting ends of the linear electrodes respectively to each other and extending along the second direction,
the linear electrodes of one of the first pixel electrodes overlap one of the first common electrodes in a plan view, and the connection portion of the one of the first pixel electrodes overlaps a first slit between the one of the first common electrode and one of the second common electrodes in the plan view,
the linear electrodes of one of the second pixel electrodes overlap one of the second common electrodes in the plan view, and the connection portion of the one of the second pixel electrodes overlaps a second slit between the one of the second common electrodes and one of the first common electrodes in the plan view,
the first slit and the second slit extend along the second direction and do not overlap each of the video signal lines, and
a first common potential applied to the first common electrodes is different from a second common potential applied to the second common electrodes.

2. The liquid crystal display device of claim 1 , wherein
the first common potential alternates between a first potential and a second potential higher than the first potential from one frame to a next,
the second common potential is at antiphase to the first common potential and alternates between the second potential and the first potential,
in a frame where the first common potential is the first potential and the second common potential is the second potential, a potential of a video signal supplied from the video signal lines to the first pixel electrodes is in a range from the first potential to the second potential, and a potential of a video signal supplied from the video signal lines to the second pixel electrodes is in a range from the second potential to the first potential.

3. The liquid crystal display device of claim 1 , wherein
the first common potential alternates between a first potential and a third potential higher than the first potential from one frame to a next,
the second common potential is at antiphase to the first common potential and alternates between the third potential and the first potential,
in a frame where the first common potential is the first potential and the second common potential is the third potential, a potential of a video signal supplied from the video signal lines to the first pixel electrodes is in a range from the first potential to a second potential higher than the third potential, and a potential of a video signal supplied from the video signal lines to the second pixel electrodes is in a range from the third potential to a fourth potential lower than the first potential.

4. The liquid crystal display device of claim 1 , wherein
the first common electrodes respectively overlap even-numbered ones of the video signal lines without overlapping odd-numbered ones of the video signal lines, whereas the second common electrodes respectively overlap odd-numbered ones of the video signal lines without overlapping even-numbered ones of the video signal lines.

5. The liquid crystal display device of claim 1 , wherein
in the first direction, the connection portion has a width greater than that of the first slit or the second slit, and overlaps one of the first common electrodes and one of the second common electrodes.

6. The liquid crystal display device of claim 1 , wherein
the first common electrodes overlap the linear electrodes of the first pixel electrodes arranged along the second direction intersecting the first direction, and
the second common electrodes overlap the linear electrodes of the second pixel electrodes arranged along the second direction.

7. The liquid crystal display device of claim 1 , wherein
the second substrate further comprises a light-shielding layer overlapping the scanning signal lines and the video signal lines, and
the light-shielding layer overlaps at least part of the connection portions.

8. The liquid crystal display device of claim 7 , wherein the light-shielding layer overlaps distal ends of the linear electrodes.

9. The liquid crystal display device of claim 1 , wherein in a thickness direction of the first substrate, the pixel electrodes are located between the common electrodes and the liquid crystal layer.

10. The liquid crystal display device of claim 1 , wherein
the first substrate further comprises a first alignment film in contact with the liquid crystal layer,
the second substrate further comprises a second alignment film in contact with the liquid crystal layer,
the first alignment film and the second alignment film have a function of aligning liquid crystal molecules contained in the liquid crystal layer along an initial alignment direction, and
the initial alignment direction coincides with the first direction.

11. The liquid crystal display device of claim 10 , wherein the liquid crystal molecules have a positive dielectric anisotropy.

12. The liquid crystal display device of claim 1 , wherein the linear electrodes each have a shape tapered off towards a distal end.

13. The liquid crystal display device of claim 1 , wherein the linear electrodes each include a first side and a second side arranged along a second direction intersecting the first direction, and a top side which connects the first side and the second side to each other.

14. The liquid crystal display device of claim 13 , wherein the first side and the second side are inclined with respect to the first direction.

15. The liquid crystal display device of claim 13 , wherein
in a vicinity of the first side, liquid crystal molecules contained in the liquid crystal layer rotate in a first rotational direction according to voltage applied between one of the pixel electrodes and one of the common electrodes, and
in a vicinity of the second side, liquid crystal molecules contained in the liquid crystal layer rotate in a second rotational direction different from the first rotational direction according to voltage applied between one of the pixel electrodes and one of the common electrodes.

16. The liquid crystal display device of claim 15 , wherein
an area where liquid crystal molecules contained in the liquid crystal layer do not rotate even when voltage is applied between one of the pixel electrodes and one of the common electrodes, is generated between the first side and the second side of the one of the pixel electrodes.

Assignees

• Japan Display Inc

Inventors

• Matsushima Toshiharu
• Yata Tatsuya

Classifications

• G09G3/3614 Primary

  Control of polarity reversal in general · CPC title

• G02F2201/121

  common or background · CPC title

• G02F1/133512

  Light shielding layers, e.g. black matrix (G02F1/136209 takes precedence) · CPC title

• G02F1/134363

  for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS] · CPC title

• G09G2300/0478

  related to liquid crystal pixels · CPC title