CN-115064564-B - Micro light emitting diode display device

CN115064564BCN 115064564 BCN115064564 BCN 115064564BCN-115064564-B

Abstract

The micro light emitting diode display device comprises a light emitting layer, a color conversion layer arranged on the light emitting surface of the light emitting layer and a Bragg reflection element arranged on the color conversion layer. The Bragg reflection element comprises a plurality of layer pairs, each layer pair is composed of a plurality of first layers and a plurality of second layers which are alternately stacked. The layer pairs include a first layer pair, a last layer pair, and an intermediate layer pair between the first layer pair and the last layer pair. The thickness of the first layer of each of the intermediate layer pairs is less than the thickness of the second layer. The refractive index of the first layer is greater than the refractive index of the second layer. Therefore, the micro light emitting diode display device can increase the visible light transmission efficiency and the ultraviolet light filtering effect.

Inventors

Miao Wenqian
JIANG XIN
Xiao Fuhe
PENG JUNYAN
CHEN SHICHENG
GUO HAOZHONG

Assignees

鸿海精密工业股份有限公司

Dates

Publication Date: 20260512
Application Date: 20220802

Claims (12)

1. A micro light emitting diode display device, comprising: a light emitting layer; a color conversion layer disposed on the light emitting surface of the light emitting layer, and The Bragg reflection element is arranged on the color conversion layer, and comprises a plurality of layer pairs, each layer pair consists of at least one first layer and at least one second layer which are alternately stacked, wherein the plurality of layer pairs comprise: A first layer pair; End layer pair, and A plurality of intermediate layer pairs between the first layer pair and the last layer pair, the thickness of the first layer of each of the plurality of intermediate layer pairs being less than the thickness of the second layer; wherein the refractive index of the plurality of first layers is greater than the refractive index of the plurality of second layers, The thicknesses of the first layers of the intermediate layer pairs are less than lambda/4 n 1 and the thicknesses of the second layers of the intermediate layer pairs are greater than lambda/4 n 2 , where lambda is the emission wavelength of the light emitting layer, n 1 is the refractive index of the first layers, and n 2 is the refractive index of the second layers.
2. The display device of claim 1, wherein a sum of a thickness of the first layer and a thickness of the second layer of the first layer pair is less than a sum of a thickness of the first layer and a thickness of the second layer of each of the plurality of intermediate layer pairs.
3. The display device of claim 1, wherein a sum of a thickness of the first layer and a thickness of the second layer of the last layer pair is less than a sum of a thickness of the first layer and a thickness of the second layer of each of the plurality of intermediate layer pairs.
4. The display device of claim 1, wherein a sum of a thickness of the first layer and a thickness of the second layer of the first layer pair is greater than a sum of a thickness of the first layer and a thickness of the second layer of the last layer pair.
5. The display device of claim 1, wherein a thickness of the first layer pair is greater than a thickness of the first layer of the last layer pair.
6. The display device of claim 1, wherein the second layer of the first layer pair has a thickness greater than a thickness of the second layer of the last layer pair.
7. The display device of claim 1, wherein the light emitting layer comprises a plurality of ultraviolet light micro-leds and the plurality of ultraviolet light micro-leds are configured to emit ultraviolet light, respectively, and wherein the color conversion layer comprises a red wavelength conversion substance, a green wavelength conversion substance, and a blue wavelength conversion substance corresponding to the plurality of ultraviolet light micro-leds, respectively, to convert the plurality of ultraviolet light into red light, green light, and blue light, respectively.
8. The display device according to claim 1, further comprising another bragg reflection element disposed on a surface of the light emitting layer opposite to the light emitting surface, wherein the another bragg reflection element comprises a plurality of layer pairs, each layer pair being composed of a plurality of first layers and a plurality of second layers stacked alternately, wherein the plurality of layer pairs comprises: A first layer pair; End layer pair, and A plurality of intermediate layer pairs positioned between the first layer pair and the last layer pair; Wherein the refractive index of the plurality of first layers is greater than the refractive index of the plurality of second layers.
9. A display device as claimed in claim 8, characterized in that the layer pairs of the further bragg reflection element are identical to the layer pairs of the bragg reflection element, respectively.
10. The display device according to claim 8, wherein a thickness of each of the plurality of first layers of the other bragg reflective element is the same as each other and a thickness of each of the plurality of second layers is the same as each other.
11. The display device of claim 8, wherein the first layer pair of the another bragg reflective element is connected to the light emitting layer.
12. The display device of claim 1, wherein the last layer pair of bragg reflective elements is connected to the color conversion layer.

Description

Micro light emitting diode display device Technical Field The invention relates to a micro light emitting diode device. Background Micro light emitting diodes (micro LIGHT EMITTING diode) are further reduced in size to achieve a high resolution display, and can meet the high-immersion experience of Virtual Reality (VR) and the high-brightness requirement of augmented reality (augmented reality; AR) against ambient light. Micro light emitting diodes (micro light emitting diodes) (OLEDs) are superior to currently used LCD technology and Organic LIGHT EMITTING Diode (OLED) in terms of lifetime, reaction time, color saturation, pixel density, and energy saving. However, the micro light emitting diode has a problem of insufficient light emitting efficiency. For example, there is a considerable fall between the converted light and the original light, resulting in a decrease in brightness for subsequent applications. In view of this, how to provide a micro light emitting diode display device that can overcome the above problems is still one of the targets of the current efforts in the industry. Disclosure of Invention The technical aspect of the invention is a micro light emitting diode display device. According to some embodiments of the present invention, a micro light emitting diode display device includes a light emitting layer, a color conversion layer, and a Bragg reflection element. The color conversion layer is arranged on the light emitting surface of the light emitting layer. The Bragg reflection element is arranged on the color conversion layer, the Bragg reflection element is provided with a plurality of layer pairs, each layer pair is composed of at least one first layer and at least one second layer which are alternately stacked, the layer pairs comprise a first layer pair, a last layer pair and an intermediate layer pair which is positioned between the first layer pair and the last layer pair, and the thickness of the first layer of each intermediate layer pair is smaller than that of the second layer. The refractive index of the first layer is greater than the refractive index of the second layer. In some embodiments of the invention, the first layer of the intermediate layer pair has a thickness less than λ/4n 1 and the second layer of the intermediate layer pair has a thickness greater than λ/4n 2, where λ is the emission wavelength of the light-emitting layer, n 1 is the refractive index of the first layer, and n 2 is the refractive index of the second layer. In some embodiments of the invention, the sum of the thickness of the first layer and the thickness of the second layer of the first layer pair is less than the sum of the thickness of the first layer and the thickness of the second layer of each of the intermediate layer pairs. In some embodiments of the invention, the sum of the thickness of the first layer and the thickness of the second layer of the last layer pair is less than the sum of the thickness of the first layer and the thickness of the second layer of each of the intermediate layer pairs. In some embodiments of the invention, the sum of the thickness of the first layer and the thickness of the second layer of the first layer pair is greater than the sum of the thickness of the first layer and the thickness of the second layer of the last layer pair. In some embodiments of the invention, the first layer of the first layer pair has a thickness greater than the thickness of the first layer of the last layer pair. In some embodiments of the invention, the second layer of the first layer pair has a thickness greater than the thickness of the second layer of the last layer pair. In some embodiments of the present invention, the light emitting layer includes a plurality of uv micro light emitting diodes, and the uv micro light emitting diodes are configured to emit uv light, respectively, wherein the color conversion layer includes red wavelength conversion substances, green wavelength conversion substances, and blue wavelength conversion substances corresponding to the uv micro light emitting diodes, respectively, to convert the uv light into red light, green light, and blue light, respectively. In some embodiments of the present invention, the micro light emitting diode display device further includes another bragg reflection element disposed on a surface of the light emitting layer opposite to the light emitting surface, wherein the another bragg reflection element includes a plurality of layer pairs, and each layer pair is composed of a plurality of first layers and a plurality of second layers stacked alternately. The layer pairs include a first layer pair, a last layer pair, and a plurality of intermediate layer pairs between the first layer pair and the last layer pair. The refractive index of the first layer is greater than the refractive index of the second layer. In some embodiments of the invention, the pairs of layers of the other Bragg reflector element are the same as t