US-12628521-B2 - Display device

US12628521B2US 12628521 B2US12628521 B2US 12628521B2US-12628521-B2

Abstract

A display device includes a display substrate and a color conversion substrate. The color conversion substrate includes: a second base substrate in which first to third light transmitting areas, and a light blocking area between adjacent light transmitting areas are defined, a first bank in the light blocking area, a first low refractive index layer between the second base substrate and the display substrate and covering the first bank. The color conversion substrate further includes a first wavelength conversion pattern in the first light transmitting area, a second wavelength conversion pattern in the second light transmitting area, and a light transmission pattern in the third light transmitting area, which are between the first low refractive index layer and the display substrate. The first low refractive index layer has a refractive index lower than at least one of the first wavelength conversion pattern or the second wavelength conversion pattern.

Inventors

Jang Il KIM
Kyoung Hae MIN
Jea Heon Ahn
Seong Yeon LEE
Si Wan JEON
Seok Joon Hong

Assignees

SAMSUNG DISPLAY CO., LTD.

Dates

Publication Date: 20260512
Application Date: 20211115
Priority Date: 20201218

Claims (20)

1 . A display device comprising: a display substrate comprising a light emitting element disposed on a first base substrate; and a color conversion substrate facing the display substrate, wherein the color conversion substrate comprises: a second base substrate in which a first light transmitting area, a second light transmitting area, a third light transmitting area, and a light blocking area disposed between adjacent light transmitting areas among the first to third light transmitting areas are defined; a first bank disposed in the light blocking area on the second base substrate; a first low refractive index layer disposed between the second base substrate and the display substrate and covering the first bank; a first wavelength conversion pattern disposed in the first light transmitting area and between the first low refractive index layer and the display substrate; a second wavelength conversion pattern disposed in the second light transmitting area and between the first low refractive index layer and the display substrate; and a light transmission pattern disposed in the third light transmitting area and between the first low refractive index layer and the display substrate, wherein the first low refractive index layer has a refractive index lower than a refractive index of at least one of the first wavelength conversion pattern or the second wavelength conversion pattern, wherein, in the first to third light transmitting areas, the first low refractive index layer has a first thickness, wherein, in the light blocking area, the first low refractive index layer has a second thickness, and wherein the first thickness is greater than the second thickness.
2 . The display device of claim 1 , wherein the first bank comprises a bottom surface facing the display substrate and a side surface facing one of the adjacent light transmitting areas, and the first low refractive index layer covers the bottom surface and the side surface of the first bank.
3 . The display device of claim 2 , wherein the first low refractive index layer is in contact with each of the bottom surface and the side surface of the first bank.
4 . The display device of claim 2 , further comprising a second bank disposed between the display substrate and the first low refractive index layer on the light blocking area, wherein the second bank is in direct contact with the first low refractive index layer.
5 . The display device of claim 1 , wherein the refractive index of the first low refractive index layer is about 1.3 to about 1.4, and the refractive index of the at least one of the first wavelength conversion pattern or the second wavelength conversion pattern is about 1.6 or more.
6 . The display device of claim 5 , wherein the first low refractive index layer includes an organic material and inorganic particles, and the inorganic particles are dispersed in the organic material and have hollow particles.
7 . The display device of claim 1 , wherein the first thickness is at least five times greater than the second thickness.
8 . The display device of claim 1 , wherein the light emitting element emits light of a first color, the first wavelength conversion pattern is configured to convert the light of the first color into light of a second color, the second wavelength conversion pattern is configured to convert the light of the first color into light of a third color, and the light transmission pattern is configured to transmit the light of the first color as it is without wavelength change.
9 . The display device of claim 8 , further comprising: a first color filter disposed in the first light transmitting area and between the second base substrate and the first low refractive index layer; a second color filter disposed in the second light transmitting area and between the second base substrate and the first low refractive index layer; and a third color filter disposed in the third light transmitting area and the light blocking area and between the second base substrate and the first low refractive index layer, wherein the first color filter is configured to block the light of the first color and the light of the third color, the second color filter is configured to block the light of the first color and the light of the second color, and the third color filter is configured to block the light of the second color and the light of the third color.
10 . The display device of claim 9 , wherein the first color filter is further disposed in the adjacent light blocking area, and the second color filter is further disposed in the adjacent light blocking area.
11 . The display device of claim 8 , wherein the first reflective layer contacts at least one of the transistor layer, the light-emitting element layer, and the wavelength conversion layer.
12 . A display device comprising: a display substrate comprising a light emitting element disposed on a first base substrate; and a color conversion substrate facing the display substrate, wherein the color conversion substrate comprises: a second base substrate in which a first light transmitting area, a second light transmitting area, a third light transmitting area, and a light blocking area disposed between adjacent light transmitting areas among the first to third light transmitting areas are defined; a first bank disposed in the light blocking area on the second base substrate; a first low refractive index layer disposed between the second base substrate and the display substrate and covering the first bank; a first wavelength conversion pattern disposed in the first light transmitting area and between the first low refractive index layer and the display substrate; a second wavelength conversion pattern disposed in the second light transmitting area and between the first low refractive index layer and the display substrate; and a light transmission pattern disposed in the third light transmitting area and between the first low refractive index layer and the display substrate, wherein the first low refractive index layer has a refractive index lower than a refractive index of at least one of the first wavelength conversion pattern or the second wavelength conversion pattern, wherein the first bank comprises a bottom surface facing the display substrate and a side surface facing one of the adjacent light transmitting areas, wherein the first low refractive index layer covers the bottom surface and the side surface of the first bank, wherein a second low refractive index layer is disposed between the first low refractive index layer and the first to second wavelength conversion patterns, and between the first low refractive index layer and the light transmission pattern, and wherein the second low refractive index layer covers the bottom surface and the side surface of the first bank.
13 . The display device of claim 12 , wherein in the first to third light transmitting areas, the first low refractive index layer has a first thickness, in the light blocking area, the first low refractive index layer has a second thickness, and the first thickness is greater than the second thickness.
14 . The display device of claim 12 , wherein a refractive index of the second low refractive index layer is about 1.2 to about 1.3.
15 . The display device of claim 12 , wherein the second low refractive index layer includes an inorganic material.
16 . The display device of claim 12 , further comprising a second bank disposed between the display substrate and the second low refractive index layer on the light blocking area, wherein the second bank is in direct contact with the second low refractive index layer.
17 . The display device of claim 16 , wherein the second bank includes a liquid repellent material, and the first to second wavelength conversion patterns and the light transmission pattern each are in direct contact with the second low refractive index layer and the second bank.
18 . A display device comprising: a base substrate in which a first emission area, a second emission area, a third emission area, and a non-emission area disposed between adjacent emission areas are defined; light emitting elements disposed in each of the emission areas on the base substrate; a thin film encapsulation layer disposed on the light emitting elements; first banks disposed on the thin film encapsulation layer and disposed in the non-emission area; a first wavelength conversion pattern disposed between adjacent first banks among the first banks on the thin film encapsulation layer and disposed in the first emission area; a second wavelength conversion pattern disposed between adjacent first banks among the first banks on the thin film encapsulation layer and disposed in the second emission area; a light transmission pattern disposed between adjacent first banks among the first banks on the thin film encapsulation layer and disposed in the third emission area; and a low refractive index layer covering upper surfaces of the first and second wavelength conversion patterns, the light transmission pattern, and the first banks, wherein the low refractive index layer has a refractive index lower than a refractive index of at least one of the first wavelength conversion pattern or the second wavelength conversion pattern.
19 . The display device of claim 18 , wherein the low refractive index layer is in direct contact with a top surface and a side surface of the first banks.
20 . The display device of claim 19 , further comprising a second bank disposed on the non-emission area on the low refractive index layer.

Description

TECHNICAL FIELD The present disclosure relates to a display device. BACKGROUND ART The importance of display devices has steadily increased with the development of multimedia technology. Accordingly, various types of display devices such as a liquid crystal display (“LCD”) device, an organic light emitting diode (“OLED”) display device and the like have been developed. Among the display devices, a self-light emitting display device includes a self-light emitting element such as an organic light emitting element. The self-light emitting element may include two opposite electrodes and a light emitting layer interposed therebetween. In the case of using the organic light emitting element as the self-light emitting element, the electrons and holes from the two electrodes are recombined in the light emitting layer to produce excitons, which transition from the excited state to the ground state, emitting light. Such a self-light emitting display device is attracting attention as a next-generation display device because of being able to meet the high display quality demands such as wide viewing angle, high brightness and contrast, and quick response speed as well as being able to be made having a low power consumption, lightweight, and thin due to no necessity of a separate power source. DISCLOSURE Technical Problem As one method for allowing each pixel of the display device to uniquely display one primary color, there is a method of arranging a color conversion pattern or a wavelength conversion pattern for each pixel on an optical path from a light source to a viewer. Aspects of the present disclosure provide a display device having a reduced reflectance of external light in a light blocking area. It should be noted that aspects of the present disclosure are not limited to the above-mentioned aspects, and other unmentioned aspects of the present disclosure will be clearly understood by those skilled in the art from the following descriptions. Technical Solution According to one embodiment of the present disclosure, there is provided a display device including a display substrate including: a light emitting element disposed on a first base substrate; and a color conversion substrate facing the display substrate, wherein the color conversion substrate includes a second base substrate in which a first light transmitting area, a second light transmitting area, a third light transmitting area, and a light blocking area disposed between adjacent light transmitting areas among the first to third light transmitting areas are defined; a first bank disposed in the light blocking area on the second base substrate; a first low refractive index layer disposed between the second base substrate and the display substrate and covering the first bank; a first wavelength conversion pattern disposed in the first light transmitting area and between the first low refractive index layer and the display substrate; a second wavelength conversion pattern disposed in the second light transmitting area and between the first low refractive index layer and the display substrate; and a light transmission pattern disposed in the third light transmitting area and between the first low refractive index layer and the display substrate, wherein the first low refractive index layer has a refractive index lower than a refractive index of at least one of the first wavelength conversion pattern or the second wavelength conversion pattern. The first bank may include a bottom surface facing the display substrate and a side surface facing one of the adjacent light transmitting areas, and the first low refractive index layer may cover the bottom surface and the side surface of the first bank. The first low refractive index layer may be in contact with each of the bottom surface and the side surface of the first bank. The refractive index of the first low refractive index layer may be about 1.3 to about 1.4, and the refractive index of the at least one of the first wavelength conversion pattern or the second wavelength conversion pattern may be about 1.6 or more. The first low refractive index layer may include an organic material and inorganic particles, and the inorganic particles may be dispersed in the organic material and have hollow particles. In the first to third light transmitting areas, the first low refractive index layer may have a first thickness, and in the light blocking area, the first low refractive index layer may have a second thickness. The first thickness may be greater than the second thickness. The first thickness may be at least five times greater than the second thickness. The display device may further include a second low refractive index layer disposed between the first low refractive index layer and the first to second wavelength conversion patterns, and between the first low refractive index layer and the light transmission pattern. The second low refractive index layer may cover the bottom surface and the side surface of the