Liquid crystal display device

Patent metadata

Field	Value
Publication number	US-10216034-B2
Application number	US-201515318037-A
Country	US
Kind code	B2
Filing date	Jun 12, 2015
Priority date	Jun 13, 2014
Publication date	Feb 26, 2019
Grant date	Feb 26, 2019

Abstract

A liquid crystal display device (100) includes a first liquid crystal display panel (1) configured to be capable of taking a transparent displaying state and a second liquid crystal display panel (2), such that the first liquid crystal display panel allows at least a portion of light going out of the second liquid crystal display panel to be transmitted in the transparent displaying state. The first liquid crystal display panel includes a first liquid crystal layer (1L) interposed between a pair of substrates, and first and second polarizers (1F, 1B) between which the first liquid crystal layer is interposed; the second liquid crystal display panel includes a second liquid crystal layer (2L) interposed between a pair of substrates, and a third polarizer (2F) placed on a side of the second liquid crystal layer that is closer to the first liquid crystal display panel; the second polarizer (1B) of the first liquid crystal display panel is on a side closer to the second liquid crystal display panel; and a transmission axis of the second polarizer (1B) and a transmission axis of the third polarizer (2F) are not orthogonal.

First claim

The invention claimed is:

1. A liquid crystal display device comprising:
a first liquid crystal display panel and a second liquid crystal display panel, the first liquid crystal display panel capable of being in a transparent displaying state, such that the first liquid crystal display panel allows at least a portion of light emitted from the second liquid crystal display panel to be transmitted in the transparent displaying state, wherein,
the first liquid crystal display panel includes a pair of substrates, a first liquid crystal layer between the pair of substrates, and a first polarizer and a second polarizer between which the first liquid crystal layer is interposed;
the second liquid crystal display panel includes a pair of substrates, a second liquid crystal layer between the pair of substrates, and a third polarizer on a side of the second liquid crystal layer that is closer to the first liquid crystal display panel;
the second polarizer of the first liquid crystal display panel is on a side closer to the second liquid crystal display panel;
a transmission axis of the second polarizer and a transmission axis of the third polarizer are not orthogonal;
each of the first liquid crystal display panel and the second liquid crystal display panel includes a plurality of pixels;
each of substantially all of the plurality of pixels of the first liquid crystal display panel is capable of switchably presenting a black displaying state and a white displaying state;
each of substantially all of the plurality of pixels of the second liquid crystal display panel is capable of switchably presenting the black displaying state and the white displaying state;
the second liquid crystal layer is a twisted nematic-type liquid crystal layer; and
a twist direction of liquid crystal molecules in the first liquid crystal layer of the first liquid crystal display panel and a twist direction of liquid crystal molecules in the second liquid crystal layer of the second liquid crystal display panel are opposite to each other.

2. The liquid crystal display device of claim 1 ,
wherein
the first liquid crystal display panel performs multicolor displaying by a field sequential method.

3. The liquid crystal display device of claim 1 , wherein the transmission axis of the second polarizer and the transmission axis of the third polarizer constitute an angle of not less than 0° and not more than 45°.

4. The liquid crystal display device of claim 3 , wherein the transmission axis of the second polarizer and the transmission axis of the third polarizer are parallel.

5. The liquid crystal display device of claim 1 , wherein the first liquid crystal layer is a twisted nematic-type liquid crystal layer, and the first polarizer and the second polarizer are oriented in crossed Nicols.

6. The liquid crystal display device of claim 2 , wherein both of the first liquid display panel and the second liquid crystal display panel perform multicolor displaying by a field sequential method.

7. The liquid crystal display device of claim 1 , wherein the first liquid crystal display panel does not include any color filters.

8. The liquid crystal display device of claim 1 , wherein the first liquid crystal display panel and the second liquid crystal display panel at least partially overlap when viewed from a normal direction.

9. The liquid crystal display device of claim 1 , wherein,
the first liquid crystal display panel includes a first horizontal alignment film on a side of the first liquid crystal layer that is closer to the first polarizer, the first horizontal alignment film having a first direction of alignment regulation and being in contact with the first liquid crystal layer;
the second liquid crystal display panel includes a second horizontal alignment film on a side of the second liquid crystal layer that is closer to the third polarizer, the second horizontal alignment film having a second direction of alignment regulation and being in contact with the second liquid crystal layer; and
an absorption axis of the first polarizer and the first direction of alignment regulation are parallel, and an absorption axis of the second polarizer and the second direction of alignment regulation are orthogonal.

10. The liquid crystal display device of claim 1 , wherein,
the first liquid crystal display panel includes a first horizontal alignment film on a side of the first liquid crystal layer that is closer to the first polarizer, the first horizontal alignment film having a first direction of alignment regulation and being in contact with the first liquid crystal layer;
the second liquid crystal display panel includes a second horizontal alignment film on a side of the second liquid crystal layer that is closer to the third polarizer, the second horizontal alignment film having a second direction of alignment regulation and being in contact with the second liquid crystal layer; and
an absorption axis of the first polarizer and the first direction of alignment regulation are orthogonal, and an absorption axis of the second polarizer and the second direction of alignment regulation are parallel.

11. The liquid crystal display device of claim 1 , wherein,
the first liquid crystal display panel includes a first substrate and a second substrate as the pair of substrates, such that the first liquid crystal layer is interposed between the first substrate and the second substrate;
the first substrate includes a first electrode and a second electrode which generates a lateral field across the first liquid crystal layer with the first electrode;
the second substrate includes a third electrode which generates a vertical field across the liquid crystal layer with the first electrode and the second electrode, the third electrode opposing the first electrode and the second electrode; and
for each pixel, the first liquid crystal display panel is capable of switchably presenting a black displaying state where black displaying is performed with a vertical field generated across the first liquid crystal layer, a white displaying state where white displaying is performed with a lateral field generated across the first liquid crystal layer, and the transparent displaying state, where a rear face side of the first liquid crystal display panel is visible in a see-through manner with no voltage applied to the first liquid crystal layer.

Assignees

• Sharp Kk

Inventors

• Kita Yuichi
• Nakatani Yoshiki
• Sasaki Takahiro
• Aoyama Iori
• Hanaoka Kazutaka

Classifications

• G02F2203/01

  transmissive · CPC title

• G02F1/1337

  Surface-induced orientation of the liquid crystal molecules, e.g. by alignment layers · CPC title

• G02F1/134363

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

• G02F1/13471 Primary

  in which all the liquid crystal cells or layers remain transparent, e.g. FLC, ECB, DAP, HAN, TN, STN, SBE-LC cells (G02F1/13475 takes precedence) · CPC title

• G02F2001/133531

  Physics · mapped topic