Liquid crystal display device

• US 9,001,291 B2
• Filed: 01/24/2012
• Issued: 04/07/2015
• Est. Priority Date: 07/19/2011
• Status: Active Grant

• Current Assignee: Japan Display Incorporated
• Original Assignee: Japan Display Incorporated
• Inventors: Watakabe, Hajime, Hiramatsu, Masato, Ishida, Arichika
• Primary Examiner(s): Caley, Michael
• Assistant Examiner(s): LAU, EDMOND C
• Application Number:
  US13/357,196
• Publication Number:
  US 20130021550A1
• Time in Patent Office: 1,169 Days
• Field of Search: 349/106
• US Class Current: 349/106
• CPC Class Codes: G02F 1/133514 Colour filters
• CPC Class Codes: G02F 1/133521 Interference filters
• CPC Class Codes: G02F 1/136209 Light shielding layers, e.g. black matrix, incorporated in the active matrix substrate, e.g. structurally associated with the switching element
• CPC Class Codes: G02F 1/136222 Colour filters incorporated in the active matrix substrate
• CPC Class Codes: G02F 2201/346 distributed (Bragg) reflector
• CPC Class Codes: G02F 2202/104 poly-Si
• CPC Class Codes: G09G 3/3607 for displaying colours or for displaying grey scales with a specific pixel layout, e.g. using sub-pixels display of colours in flat matrix panels other than liquid crystal displays G09G3/2003; grey scales specific for television H04N3/127
• CPC Class Codes: G09G 5/02 characterised by the way in which colour is displayed details of colour display specific for CRTs G09G1/28; specific for flat matrix panels other than liquid crystal displays G09G3/2003; specific for liquid crystal displays G09G3/3607

Abstract

According to one embodiment, a liquid crystal display device includes an array substrate including a first color filter configured to transmit light in a first wavelength range, a second color filter configured to transmit light in a second wavelength range of greater wavelengths than the first wavelength range, a first switching element disposed above the second color filter, a second switching element disposed above the second color filter, a first pixel electrode which is electrically connected to the first switching element and is located above the first color filter, and a second pixel electrode which is electrically connected to the second switching element and is located above the second color filter.

Claims

1. A liquid crystal display device comprising an array substrate comprising:

a gate line;

a first source line and a second source line which cross the gate line;

a first color filter configured to transmit light in a first wavelength range;

a second color filter configured to transmit light in a second wavelength range of greater wavelengths than the first wavelength range;

a first switching element disposed above the second color filter;

a second switching element disposed above the second color filter;

a first pixel electrode which is electrically connected to the first switching element and is located directly above the first color filter; and

a second pixel electrode which is electrically connected to the second switching element and is located directly above the second color filter,

wherein the first switching element is electrically connected to the gate line and the first source line, and the second switching element is electrically connected to the gate line and the second source line.

2. The liquid crystal display device of claim 1, wherein the first color filter and the second color filter are constructed by stacking a plurality of thin films with different refractive indices.

3. The liquid crystal display device of claim 2, wherein the first color filter and the second color filter are a dielectric film multilayer in which a silicon nitride layer and a silicon oxide layer are alternately stacked.

4. The liquid crystal display device of claim 1, further comprising a backlight disposed on a back side of the array substrate,

wherein a light emission spectrum of the backlight has a light emission peak in the first wavelength range.

5. The liquid crystal display device of claim 1, wherein the first wavelength range is a blue wavelength range.

6. A liquid crystal display device comprising an array substrate comprising:

an insulative substrate;

a first semi-transmissive layer disposed on the insulative substrate;

a first transmissive layer with a first film thickness, a second transmissive layer with a second film thickness which is different from the first film thickness, and a third transmissive layer with a third film thickness which is different from the first film thickness and the second film thickness, the first transmissive layer, the second transmissive layer and the third transmissive layer being disposed on the first semi-transmissive layer;

a second semi-transmissive layer disposed on the first transmissive layer to constitute a first color filter configured to transmit light in a first wavelength range, disposed on the second transmissive layer to constitute a second color filter configured to transmit light in a second wavelength range of greater wavelengths than the first wavelength range, and disposed on the third transmissive layer to constitute a third color filter configured to transmit light in a third wavelength range of greater wavelengths than the second wavelength range;

a gate line;

a first source line, a second source line, and a third source line which cross the gate line;

a first switching element, a second switching element and a third switching element, which are disposed on the second semi-transmissive layer which constitutes the second color filter or the third color filter;

a first pixel electrode which is electrically connected to the first switching element and is located above the first color filter;

a second pixel electrode which is electrically connected to the second switching element and is located directly above the second color filter; and

a third pixel electrode which is electrically connected to the third switching element and is located directly above the third color filter,

wherein the first switching element is electrically connected to the gate line and the first source line, the second switching element is electrically connected to the gate line and the second source line, and the third switching element is electrically connected to the gate line and the third source line.

7. The liquid crystal display device of claim 6, wherein the first semi-transmissive layer includes a high-refractive-index layer which is stacked on the insulative substrate and has a higher refractive index than the insulative substrate, and a low-refractive-index layer which is stacked on the high refractive index layer and has a lower refractive index than the high-refractive-index layer.

8. The liquid crystal display device of claim 7, wherein the high-refractive-index layer is composed of a silicon nitride layer, and the low-refractive-index layer is composed of a silicon oxide layer.

9. The liquid crystal display device of claim 8, wherein the low-refractive-index layer is thicker than the high-refractive-index layer.

10. The liquid crystal display device of claim 6, wherein each of the first semi-transmissive layer and the second semi-transmissive layer is composed of a multilayer of a silicon nitride layer and a silicon oxide layer.

11. The liquid crystal display device of claim 10, wherein each of the first transmissive layer, the second transmissive layer, and the third transmissive layer is composed of a silicon nitride layer or a silicon oxide layer.

12. The liquid crystal display device of claim 11, wherein each of the first switching element, the second switching element and the third switching element is a top-gate-type thin-film transistor including a silicon semiconductor layer.

13. The liquid crystal display device of claim 12, wherein an in-film hydrogen amount of a silicon nitride layer, which is used for the first semi-transmissive layer, or the second semi-transmissive layer, or the first transmissive layer, or the second transmissive layer, or the third transmissive layer, is 2×

10²¹ cm<sup>−

3</sup> or more.

14. The liquid crystal display device of claim 6, further comprising a backlight disposed on a back side of the array substrate,

wherein a light emission spectrum of the backlight has a light emission peak in the first wavelength range.

15. The liquid crystal display device of claim 6, wherein the first wavelength range is a blue wavelength range.

16. A liquid crystal display device comprising an array substrate comprising:

a gate line;

a first source line and a second source line which cross the gate line;

a first pixel which displays a first color; and

a second pixel which displays a second color different from the first color;

wherein the first pixel includes a first color filter with a first film thickness, a second color filter with a second film thickness which is different from the first film thickness, a first switching element which is electrically connected to the gate line and the first source line and is located directly above the second color filter, and a first pixel electrode which is electrically connected to the first switching element and is located directly above the first color filter, the first color filter being configured to transmit the first color, and the second color filter being configured to transmit a third color different from the first color and the second color, and

the second pixel includes a third color filter with a third film thickness which is different from the first film thickness and the second film thickness, a fourth color filter with the second film thickness, a second switching element which is electrically connected to the gate line and the second source line and is located directly above the fourth color filter, and a second pixel electrode which is electrically connected to the second switching element and is located directly above the third color filter, the third color filter being configured to transmit the second color, and the fourth color filter being configured to transmit the third color.