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KR-102962873-B1 - Organic light emitting diodes

KR102962873B1KR 102962873 B1KR102962873 B1KR 102962873B1KR-102962873-B1

Abstract

The present invention relates to an organic light-emitting display device capable of realizing high brightness. The present invention is characterized by forming a light extraction layer in which a second lens is disposed corresponding to a non-luminous region of a white subpixel and a first lens is disposed corresponding to a luminous region of a white subpixel on the back surface of a substrate, which is the direction of light transmission. This improves the out-coupling efficiency by refracting light trapped inside the substrate to the outside of the substrate, thereby improving the brightness and luminous efficiency of the organic light-emitting display. In addition, since the light is concentrated by changing its path through the first lens, the front efficiency of the organic light-emitting display is also improved by the concentrated light.

Inventors

  • 양지석
  • 정동열

Assignees

  • 엘지디스플레이 주식회사

Dates

Publication Date
20260508
Application Date
20211206

Claims (12)

  1. A substrate having a pixel defined therein, including a white subpixel comprising a light-emitting region and a non-light-emitting region; A first light-emitting diode located in the above white subpixel; A light extraction layer located on the outer surface of the substrate corresponding to the transmission direction of light emitted from the first light-emitting diode. The light extraction layer includes a first lens corresponding to the light-emitting region and a second lens corresponding to the non-light-emitting region, wherein the height of the first lens is higher than the height of the second lens. Red, green, and blue subpixels are alternately arranged in the horizontal direction of the white subpixel, and the white, red, green, and blue subpixels are arranged in a stripe shape. The above non-luminous region corresponds to the region between the adjacent white subpixels in an organic light-emitting display device.
  2. In Article 1, The above light extraction layer comprises a high-refractive index layer covering the first and second lenses, forming an organic light-emitting display device.
  3. In Article 2, An organic light-emitting display device in which the first and second lenses have a first refractive index similar to the substrate, and the high refractive layer has a second refractive index greater than the first refractive index.
  4. In Paragraph 3, An organic light-emitting display device having a refractive index difference of 0.1 or more between the first refractive index and the second refractive index.
  5. In Article 1, The first lens has a first width greater than the width of the light-emitting region, and The second lens has a second width narrower than the width of the non-luminous region, and An organic light-emitting display device in which the first width is wider than the second width.
  6. In Article 5, The above first and second lenses are formed in a convex shape having a curved surface and form peaks and valleys with each other, forming an organic light-emitting display device.
  7. In Article 1, The above first and second lenses are organic light-emitting display devices having a height-to-diameter ratio of 0.5:1.
  8. delete
  9. In Article 1, The light extraction layer includes a third lens corresponding to the light-emitting regions of the red, green, and blue subpixels, and An organic light-emitting display device in which the height of the third lens is higher than the height of the second lens.
  10. In Article 1, It includes second to fourth light-emitting diodes located at the red, green, and blue subpixels, respectively, and The above first to fourth light-emitting diodes are organic light-emitting display devices that emit white, red, green, and blue light, respectively.
  11. In Article 1, It includes second to fourth light-emitting diodes located at the red, green, and blue subpixels, respectively, and The first to fourth light-emitting diodes above emit white light, and An organic light-emitting display device having red, green, and blue color filter patterns positioned between the light extraction layer and the second to fourth light-emitting diodes, corresponding to light-emitting regions for each red, green, and blue subpixel.
  12. In Article 11, An organic light-emitting display device having a white color filter pattern positioned between the light extraction layer and the first light-emitting diode, corresponding to the light-emitting region of the white subpixel.

Description

Organic light emitting diodes The present invention relates to an organic light-emitting display device capable of realizing high brightness. As society has recently entered the full-scale information age, interest in information displays capable of processing and displaying large amounts of information is increasing. Furthermore, with the rising demand for portable information media, various lightweight and thin flat panel displays designed to meet these needs are being developed and are gaining attention. In particular, among various flat panel display devices, organic light emitting diodes (OLEDs) are self-emissive devices and do not require a backlight used in liquid crystal display devices (LCDs), which are non-emissive devices, so they can be lightweight and thin. In addition, compared to liquid crystal displays, it has superior viewing angle and contrast ratio, is advantageous in terms of power consumption, enables low-voltage DC driving, has a fast response speed, is resistant to external shocks because its internal components are solid, and has the advantage of a wide operating temperature range. In order to achieve high brightness, such an organic light-emitting display device may further include a white subpixel emitting white light in addition to a red subpixel emitting red light, a green subpixel emitting green light, and a blue subpixel emitting blue light. In this case, the white subpixel has the greatest impact on high brightness implementation. FIG. 1a is a plan view showing a plurality of subpixels in an organic light-emitting display device according to a first embodiment of the present invention. FIG. 1b is a perspective view schematically illustrating the rear view of FIG. 1a. FIG. 2 is a cross-sectional view showing the structure of a unit pixel including four subpixels of an organic light-emitting display device according to a first embodiment of the present invention, cut along the cutting line II-II' of FIG. 1a. FIG. 3 is a cross-sectional view taken along the cutting line III-III' of FIG. 1a. FIG. 4 is a schematic diagram schematically illustrating the light path of an organic light-emitting display device according to a first embodiment of the present invention. FIG. 5 is a perspective view schematically illustrating the back side of an organic light-emitting display device according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view showing the structure of a unit pixel including four subpixels of an organic light-emitting display device according to a second embodiment of the present invention, cut along the cutting line VI-VI' of FIG. 5. Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. - First Example - FIG. 1a is a plan view showing a plurality of subpixels in an organic light-emitting display device according to a first embodiment of the present invention, and FIG. 1b is a perspective view schematically illustrating the rear side of FIG. 1a. As described above, the organic light-emitting display device (100) according to the first embodiment of the present invention comprises one unit pixel (P) including red, green, and blue subpixels (R-SP, G-SP, B-SP), each subpixel (R-SP, G-SP, B-SP) including a light-emitting region (EA), and a bank (119, see FIG. 2) is arranged along the edge of the light-emitting region (EA) to form a non-light-emitting region (NEA). At this time, red, green, and blue subpixels (R-SP, G-SP, B-SP) can be arranged alternately in the horizontal direction, and multiple red, green, and blue subpixels (R-SP, G-SP, B-SP) can each be arranged in the vertical direction. Accordingly, the red, green, and blue subpixels (R-SP, G-SP, B-SP) are each arranged in a stripe-like structure. Additionally, one unit pixel (P) further includes a white subpixel (W-SP), and one unit pixel (P) including red, green, blue, and white subpixels (R-SP, G-SP, B-SP, W-SP) can be formed in a square structure. Here, for the sake of convenience of explanation, each subpixel (R-SP, G-SP, B-SP, W-SP) is depicted as being positioned side by side with the same width, but each subpixel (R-SP, G-SP, B-SP, W-SP) can have various structures with different widths. At this time, a switching and driving thin-film transistor (STr, DTr) is provided on the non-emissive region (NEA) of each subpixel (R-SP, G-SP, B-SP, W-SP), and a light-emitting diode (E, see FIG. 2) including a first electrode (111, see FIG. 2), an organic light-emitting layer (113a, 113b, 113c, 113d, see FIG. 2), and a second electrode (115, see FIG. 2) is disposed on the light-emitting region (EA) within each subpixel (R-SP, G-SP, B-SP, W-SP). Here, the switching thin-film transistor (STr) and the driving thin-film transistor (DTr) are connected to each other, and the driving thin-film transistor (DTr) is connected to a light-emitting diode (E, see FIG. 2). Looking at this in more detail, the gate wiring (GL), data wiring (DL), and p