Liquid crystal display device having transmitting region and reflecting region

• US 10,025,137 B2
• Filed: 02/25/2016
• Issued: 07/17/2018
• Est. Priority Date: 08/28/2013
• Status: Active Grant

• Current Assignee: Harvest Croo, Llc
• Original Assignee: Harvest Croo, Llc
• Inventors: Arai, Norihiro, Kobayashi, Kunpei, Mizusako, Ryota
• Primary Examiner(s): Nguyen, Lauren
• Application Number:
  US15/053,547
• Publication Number:
  US 20160170263A1
• Time in Patent Office: 873 Days
• CPC Class Codes: G02F 1/133555 Transflectors
• CPC Class Codes: G02F 1/133742 for homeotropic alignment
• CPC Class Codes: G02F 1/134309 characterised by their geometrical arrangement
• CPC Class Codes: G02F 1/134363 for applying an electric field parallel to the substrate, i.e. in-plane switching [IPS]
• CPC Class Codes: G02F 1/134372 for fringe field switching [FFS] where the common electrode is not patterned
• CPC Class Codes: G02F 1/134381 Hybrid switching mode, i.e. for applying an electric field with components parallel and orthogonal to the substrates
• CPC Class Codes: G02F 1/13706 the liquid crystal having positive dielectric anisotropy

Abstract

A liquid crystal display device includes: a first substrate and a second substrate; a liquid crystal layer sandwiched between the first substrate and the second substrate, containing P-type liquid crystal molecules, and configured to be perpendicularly aligned when no electric field is applied; a pixel including a reflecting region and a transmitting region, cell gaps of the reflecting region and the transmitting region being the same; one pixel electrode formed into a line on the first electrode; a first common electrode provided on the first substrate to sandwich the pixel electrode; a second common electrode provided on the second substrate; and a reflecting film provided in the reflecting region to overlap a portion of the pixel electrode, and comprising a conductive material.

Claims

1. A liquid crystal display device comprising:

a first substrate and a second substrate opposing each other;

a liquid crystal layer sandwiched between the first substrate and the second substrate, containing P-type liquid crystal molecules, and configured to be perpendicularly aligned when no electric field is applied;

a pixel including a reflecting region and a transmitting region, the reflecting region having a cell gap distance that is the same as a cell gap distance of the transmitting region, the reflecting region being adjacent to the transmitting region in a first direction;

a pixel electrode provided on the first substrate to extend in the first direction, and located in both the reflecting region and the transmitting region;

a first common electrode including first and second portions, the first and second portions being provided on the first substrate so as to extend longitudinally in the first direction, being located on respective opposite sides of the pixel electrode in a second direction substantially perpendicular to the first direction, and each being located in both the reflecting region and the transmitting region;

a second common electrode provided on the second substrate; and

a reflecting film provided in the reflecting region to overlap a portion of the pixel electrode, and comprising a conductive material, wherein the pixel electrode and the first common electrode are not electrically connected.

2. The liquid crystal display device of claim 1, further comprising a controller that applies a same voltage to both the first common electrode and the reflecting film.

3. The liquid crystal display device of claim 1, further comprising a controller that controls the liquid crystal display device to perform a first display mode and a second display mode, wherein

in the first display mode, the controller controls the liquid crystal display device to apply a same common voltage to each of the pixel electrode, the first common electrode, the second common electrode, and the reflecting film, and

in the second display mode, the controller controls the liquid crystal display device to apply the same common voltage to each of the first common electrode, the second common electrode, and the reflecting film, and a voltage higher than the same common voltage to the pixel electrode.

4. The liquid crystal display device of claim 1, further comprising a dielectric film provided between the second common electrode and the liquid crystal layer.

5. The liquid crystal display device of claim 1, wherein the first common electrode surrounds the pixel electrode.

6. The liquid crystal display device of claim 1, further comprising an interconnection configured to supply a voltage to the pixel electrode,

wherein the first common electrode is arranged to overlap the interconnection.

7. The liquid crystal display device of claim 1, further comprising:

a first retardation plate provided on the first substrate; and

a second retardation plate provided on the second substrate,

wherein a phase difference of the first retardation plate and the second retardation plate is λ

/4.

8. The liquid crystal display device of claim 1, wherein the first common electrode is located on a same level as a level of the pixel electrode.

9. The liquid crystal display device of claim 1, wherein the first common electrode and the pixel electrode are mutually non-overlapping in a thickness direction of the liquid crystal layer.