EP-3879574-B1 - ELECTROLUMINESCENT DISPLAY APPARATUS WITH FLEXIBLE SUBSTRATE

Inventors

• LEE, CHUNG HOON

Dates

Publication Date

20260506

Application Date

20191107

Claims (9)

1. A display apparatus comprising: a flexible substrate (SUB); a plurality of light emitting devices (LED) spaced apart from one another and disposed on the flexible substrate (SUB); and a light shielding layer (LS) disposed between the light emitting devices (LED), and partially covering the light emitting devices (LED) to define light extraction areas (LEX), wherein a distance (DT1, DT2) between adjacent light extraction areas (LEX) is the same, characterised in that : each of the light emitting devices (LED) comprises a first light emitting part (LE1), a second light emitting part (LE2), and a third light emitting part (LE3), which are vertically stacked on the substrate (SUB).
2. The display apparatus according to claim 1, wherein: the light emitting devices (LED) are spaced apart from one another by a first distance (DT1) in a first direction (DR1), and by a second distance (DT2) in a second direction (DR2) perpendicular to the first direction; and the first distance (DT1) is equal to or greater than the second distance (DT2).
3. The display apparatus according to claim 2, wherein the substrate (SUB) is configured to be rolled in the first direction (DR1).
4. The display apparatus according to claim 2, wherein: the first distance (DT1) is greater than the second distance (DT2); and a length of each light emitting device (LED) in the second direction (DR2) is greater than a length of a corresponding light extraction area (LEX) in the second direction (DR2).
5. The display apparatus according to claim 1, further comprising a common circuit (CC) electrically coupled in common with the light emitting devices (LED), wherein the common circuit (CC) is disposed on the substrate (SUB) and has a mesh structure.
6. The display apparatus according to claim 1, further comprising a protection layer (PRT) covering the light emitting devices (LED) on the substrate (SUB), the protection layer (PRT) including a material that transmits visible light.
7. The display apparatus according to claim 1, wherein a hardness of the substrate (SUB) is less than a hardness of each of the light emitting devices (LED).
8. The display apparatus according to claim 1, wherein: the third light emitting part (LE3) has a width less than that of the second light emitting part (LE2), and the second light emitting part (LE2) has a width less than that of the first light emitting part (LE1).
9. The display apparatus according to claim 1, wherein each of the light emitting devices (LED) has a width that gradually decreases in an upward direction from one surface of the substrate (SUB).

Description

[Technical field] Exemplary embodiments of the invention relate generally to a display apparatus and, more specifically, to a flexible display apparatus. [Background art] In general, a display apparatus includes a display panel, which displays an image by using light, and a backlight unit, which provides light to the display panel. The display panel includes a plurality of pixel cells each including a switching element, a pixel electrode, a common electrode, and a color layer. As the display panel, a liquid crystal display panel is widely used. Light provided by the backlight unit passes through liquid crystals and the color layer, and the display apparatus may display a color image by mixture of colored lights. The color layer for displaying a color image includes, for example, a red color filter, a green color filter, and a blue color filter. By mixing of light having passed through the color filters, various colors may be displayed. As such, in order to realize light of various colors for displaying an image, the color filters are needed. Moreover, liquid crystals may require polarization, and thus, a polarizing filter and various optical films are typically needed. As such, the display apparatus becomes thick and heavy. The US 2016/0351539 A1 discloses a display device comprising a flexible substrate, a plurality of LEDs disposed on the substrate, and a light shielding layer partly covering the LEDs, defining optical vias (28). The US 2006/0082297 A1 discloses an array of LEDs (10) provided on a substrate (12), wherein each LED is covered by a transparent protection layer (20). The US 2007/0170444 A1 discloses a multi-color emitting LED chip with vertically stacked LEDs. [Disclosure] [Technical Problem] A display apparatus including a plurality of light emitting diodes constructed according to exemplary embodiments of the invention are capable of obviating the need of at least one or more components of a conventional display apparatus, such as liquid crystals, a backlight unit, a polarizing filter and, a color filter. Additional features of the inventive concepts will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the inventive concepts. [Technical Solution] A display apparatus according to the present invention is provided in accordance with the appended claim 1. The display apparatus of the present invention includes a flexible substrate, a plurality of light emitting devices spaced apart from one another and disposed on the flexible substrate, and a light shielding layer disposed between the light emitting devices, and partially covering the light emitting devices to define light extraction areas, in which a distance between adjacent light extraction areas is the same. Furthermore, in the display apparatus of the present invention, each of the light emitting devices includes a first light emitting part, a second light emitting part, and a third light emitting part, which are vertically stacked on the flexible substrate. The light emitting devices may be spaced apart from one another by a first distance in a first direction, and by a second distance in a second direction perpendicular to the first direction, and the first distance may be equal to or greater than the second distance. The substrate may be configured to be rolled in the first direction. The first distance may be greater than the second distance, and a length of each light emitting device in the second direction may be greater than a length of a corresponding light extraction area in the second direction. The display apparatus may further include a common circuit electrically coupled in common with the light emitting devices, in which the common circuit may be disposed on the substrate and have a mesh structure. The display apparatus may further include a protection layer covering the light emitting devices on the substrate, the protection layer including a material that transmits visible light. A hardness of the substrate may be less than a hardness of each of the light emitting devices. The third light emitting part may have a width less than that of the second light emitting part, and the second light emitting part has a width less than that of the first light emitting part. Each of the light emitting devices may have a width that gradually decreases in an upward direction from one surface of the substrate. The details of the present invention are included in the detailed description and the drawings. [Advantageous effects] In the display apparatus in accordance with the present disclosure, by displaying a plurality of light emitting devices each including a plurality of light emitting parts, on a flexible substrate, it is possible to extract light of high efficiency with small power consumption, whereby the display apparatus may be applied to various electronic apparatuses. [Description of Drawings] FIGS. 1A, 1B, and 1C are top views of a display appar