# US 2018/0024404 A1 · Electro-optical switching element and display device

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- Number: US 2018/0024404 A1
- Document ID: US20180024404A1
- Status: Published application
- Kind: A1
- Application number: 15/548,428
- Filed: 2016-01-20
- Published: 2018-01-25
- Earliest claimed: 2015-02-04
- Assignees: Merck Patent GmbH
- Applicants: Merck Patent GmbH
- Inventors: Masayoshi SUZUKI; Tadashi KISHIMOTO
- Web page: https://patentgrep.com/patent/US20180024404A1

## CPC

- G02F 1/133617: {Illumination with ultraviolet light; Luminescent elements or materials associated to the cell}
- G02F 1/133504: {Diffusing, scattering, diffracting elements (associated to illuminating devices G02F1/133606)}
- G02F 1/133514: {Colour filters}
- G02F 1/133602: {Direct backlight}
- H10K 59/38: comprising colour filters or colour changing media [CCM]
- H10K 59/877: {comprising scattering means}
- C09K 11/06: containing organic luminescent materials
- G02F 1/133609: {including means for improving the color mixing, e.g. white}
- G02F 1/133614: {using photoluminescence, e.g. phosphors illuminated by UV or blue light}
- G02F: OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE

## Abstract

The present invention relates to an electro-optical switching element comprising at least one light source, and a light converting layer, and to a use of the electro-optical switching element in an optical device. The invention further relates to an optical device comprising the electro-optical switching element.

## Claims

### Claim 1

An electro optical switching element (100), comprising at least one light source (110), and a light converting layer (120), wherein the light converting layer (120) comprises a light converting material (130) that can convert light of the wavelength of the light source (110) into longer light wavelength, and a coloring agent (140) that can absorb a visible light, wherein the coloring agent (140) is selected from the group consisting of dye, pigment and a combination of any of these, wherein the electro optical switching element (100) comprises a plural of light scattering particles (150).

### Claim 2 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the electro optical switching element (100) further comprises a light modulator (160).

### Claim 3 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the electro optical switching element (100) comprises a light scattering layer (170) including the plural of light scattering particles (150).

### Claim 4 (depends on 3)

The electro optical switching element (100) according claim 3, wherein the light source (110), the light scattering layer (170), and the light converting layer (120), are placed in this sequence.

### Claim 5 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the light converting layer (120) comprises the plural of light scattering particles (150).

### Claim 6 (depends on 2)

The electro optical switching element (100) according to claim 2, wherein the light modulator (160) is placed at the light extraction side of the light converting layer (120).

### Claim 7 (depends on 2)

The electro optical switching element (100) according to claim 2, wherein the light modulator (160) is placed in between the light source (110) and the light converting layer (120).

### Claim 8 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the surface of the light extraction side of the light converting layer (120) is structured.

### Claim 9 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the electro optical switching element (100) further comprises a layer (180) whose surface of the light extraction side is structured.

### Claim 10 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the light source (110) is switchable.

### Claim 11 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the light converting material (130) of the light converting layer (120) is selected from the group consisting of an organic fluorescent material, organic phosphorescent material, phosphor material, quantum sized inorganic semiconductor material or a combination of any of these.

### Claim 12 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the electro optical switching element (100) further comprises a selective light reflection layer (190) placed in between the light source (110) and the light converting layer (120).

### Claim 13 (depends on 1)

The electro optical switching element (100) according to claim 1, wherein the light converting layer (120) comprises first and second sub color areas (200), in which at least first sub color area emits light having longer peak wavelength than the second sub color areas when it is illuminated by light source.

### Claim 14 (depends on 1)

The electro optical switching element (100) according to claim 1, in an optical device.

### Claim 15

An optical device (210), including the electro optical switching element (100) comprising at least one light source (110), and a light converting layer (120), wherein the light converting layer (120) comprises a light converting material (130) that can convert light wavelength of the light from the light source (110) into longer light wavelength, and a coloring agent (140) that can absorb a visible light, wherein the coloring agent (140) is selected from the group consisting of dye, pigment and a combination of any of these, wherein the electro optical switching element (100) comprises a plural of light scattering particles (150).