Display device with stacked polarizers

• US 8,405,800 B2
• Filed: 01/31/2007
• Issued: 03/26/2013
• Est. Priority Date: 02/02/2006
• Status: Expired due to Fees

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Ishitani, Tetsuji, Nishi, Takeshi, Egi, Yuji
• Primary Examiner(s): Briggs, Nathanael R
• Application Number:
  US11/669,408
• Publication Number:
  US 20070177086A1
• Time in Patent Office: 2,246 Days
• Field of Search: 349 96- 97, 349/117
• US Class Current: 349/96
• CPC Class Codes: G02F 1/133528 Polarisers
• CPC Class Codes: G02F 1/133531 characterised by the arrangement of polariser or analyser axes
• CPC Class Codes: H10K 2102/3031 Two-side emission, e.g. transparent OLEDs [TOLED]
• CPC Class Codes: H10K 50/86 Arrangements for improving contrast, e.g. preventing reflection of ambient light
• CPC Class Codes: H10K 59/8791 Arrangements for improving contrast, e.g. preventing reflection of ambient light

Abstract

An object of the present invention is to provide a display device having a high contrast ratio by a simple and easy method. Another object of the present invention is to manufacture such a display device having a high contrast ratio at low cost. The present invention relates to a display device including a first substrate; a second substrate; a layer including a display element, wherein the layer including the display element is interposed between the first substrate and the second substrate; and stacked polarizers on the outer side of the first substrate or the second substrate. The stacked polarizers are arranged to be in a parallel Nicols state and the wavelength distributions of the extinction coefficients of the stacked polarizers are different from each other.

Claims

1. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element between the first substrate and the second substrate; and

stacked polarizers,

wherein the first substrate is interposed between the layer including the display element and the stacked polarizers,

wherein the stacked polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween,

wherein wavelength distributions of extinction coefficients of the stacked polarizers are different from each other,

wherein the stacked polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.

9. The display device according to any one of claims 1 to 6, wherein the display element is a liquid crystal element.

10. The display device according to any one of claims 1 to 6, wherein the display element is an electroluminescent element.

2. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element interposed between the first substrate and the second substrate;

stacked first polarizers; and

stacked second polarizers,

wherein the first substrate is interposed between the layer including the display element and the stacked first polarizers,

wherein the second substrate is interposed between the layer including the display element and the stacked second polarizers,

wherein the stacked first polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween and wavelength distributions of extinction coefficients of the stacked first polarizers are different from each other,

wherein the stacked second polarizers are arranged to be in a parallel Nicols state with each other and wavelength distributions of extinction coefficients of the stacked second polarizers are different from each other, wherein the stacked first polarizers and the stacked second polarizers are arranged to be in a crossed Nicols state,

wherein the stacked first polarizers and the stacked second polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.

3. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element interposed between the first substrate and the second substrate;

stacked first polarizers; and

stacked second polarizers,

wherein the first substrate is interposed between the layer including the display element and the stacked first polarizers,

wherein the second substrate is interposed between the layer including the display element and the stacked second polarizers,

wherein the stacked first polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween and wavelength distributions of extinction coefficients of the stacked first polarizers are different from each other;

wherein the stacked second polarizers are arranged to be in a parallel Nicols state with each other and wavelength distributions of extinction coefficients of the stacked second polarizers are different from each other,

wherein the stacked first polarizers and the stacked second polarizers are arranged to be in a parallel Nicols state,

wherein the stacked first polarizers and the stacked second polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.

4. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element interposed between the first substrate and the second substrate;

stacked polarizers; and

a retardation plate,

wherein the first substrate is interposed between the layer including the display element and the stacked polarizers,

wherein the retardation plate is interposed between the first substrate and the stacked polarizers,

wherein the stacked polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween and wavelength distributions of extinction coefficients of the stacked polarizers are different from each other,

wherein the stacked polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.

7. The display device according to claim 4, wherein absorption axes of the stacked polarizers and a slow axis of the retardation plate are arranged to be shifted by 45°

.

5. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element interposed between the first substrate and the second substrate;

stacked first polarizers;

stacked second polarizers;

a first retardation plate; and

a second retardation plate,

wherein the first substrate is interposed between the layer including the display element and the stacked first polarizers,

wherein the second substrate is interposed between the layer including the display element and the stacked second polarizers,

wherein the first retardation plate is interposed between the first substrate and the stacked first polarizers,

wherein the second retardation plate is interposed between the second substrate and the stacked second polarizers,

wherein the stacked first polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween and wavelength distributions of extinction coefficients of the stacked first polarizers are different from each other;

wherein the stacked second polarizers are arranged to be in a parallel Nicols state with each other and wavelength distributions of extinction coefficients of the stacked second polarizers are different from each other; and

wherein the stacked first polarizers and the stacked second polarizers are arranged to be in a crossed Nicols state,

wherein the stacked first polarizers and the stacked second polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.

8. The display device according to claim 5 or 6,

wherein absorption axes of the stacked first polarizers and a slow axis of the first retardation plate are arranged to be shifted by 45°

; and

wherein absorption axes of the stacked second polarizers and a slow axis of the second retardation plate are arranged to be shifted by 45°

.

6. A display device comprising:

a first substrate;

a second substrate;

a layer including a display element interposed between the first substrate and the second substrate;

stacked first polarizers;

stacked second polarizers;

a first retardation plate; and

a second retardation plate,

wherein the first substrate is interposed between the layer including the display element and the stacked first polarizers,

wherein the second substrate is interposed between the layer including the display element and the stacked second polarizers,

wherein the first retardation plate is interposed between the first substrate and the stacked first polarizers,

wherein the second retardation plate is interposed between the second substrate and the stacked second polarizers,

wherein the stacked first polarizers are arranged to be in a parallel Nicols state with each other without any light diffusing element interposed therebetween and wavelength distributions of extinction coefficients of the stacked first polarizers are different from each other;

wherein the stacked second polarizers are arranged to be in a parallel Nicols state with each other and wavelength distributions of extinction coefficients of the stacked second polarizers are different from each other; and

wherein the stacked first polarizers and the stacked second polarizers are arranged to be in a parallel Nicols state,

wherein the stacked first polarizers and the stacked second polarizers include polyvinyl alcohol and a dichroic pigment, and

wherein the dichroic pigment includes iodine and dichromatic organic dye.