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EP-4207298-B1 - DISPLAY PANEL AND PREPARATION METHOD THEREFOR, AND DISPLAY APPARATUS

EP4207298B1EP 4207298 B1EP4207298 B1EP 4207298B1EP-4207298-B1

Inventors

  • LI, WEI
  • ZHANG, YICHI
  • ZHANG, CAN
  • WANG, CAN
  • YUAN, Lijun
  • CONG, Ning
  • NIU, Jinfei
  • ZHANG, JINGJING
  • XUAN, MINGHUA

Dates

Publication Date
20260506
Application Date
20210526

Claims (15)

  1. A display panel comprising: a light emitting layer (3) on a base substrate (4), a transparent spacing layer (2) on the light emitting layer (3), and a wavelength converting layer (1) on the transparent spacing layer (2), wherein the display panel comprises sub-pixels arranged in an array, the sub-pixels arranged in an array comprise a first sub-pixel (a) and a second sub-pixel (b) adjacent to each other, wherein in each of the first sub-pixel (a) and the second sub-pixel (b), one light emitting unit (31) in the light emitting layer (3) and one wavelength converting unit (11) in the wavelength converting layer (1) are comprised, and the light emitting unit (31) and the wavelength converting unit (11) are stacked and spaced apart by the transparent spacing layer (2), the light emitting units (31a, 31b) of the first sub-pixel and the second sub-pixel are spaced apart by a first pixel defining layer (32) in the light emitting layer (3), and have a top surface spacing of d2, the wavelength converting unit of the first sub-pixel is a first wavelength converting unit (11a) which has a luminance change ratio of ra on light emitted by the light emitting unit (31a), and the wavelength converting unit of the second sub-pixel is a second wavelength converting unit (11b) which has a luminance change ratio of rb on light emitted by the light emitting unit (31b), and the wavelength converting units of the first sub-pixel and the second sub-pixel (11a, 11b) are spaced apart by a second pixel defining layer (12) in the wavelength converting layer (1), wherein the transparent spacing layer (2) in the first sub-pixel (a) and the transparent spacing layer (2) in the second sub-pixel (b) are continuous between the first pixel defining layer (32) and the second pixel defining layer (12), in a direction from the first sub-pixel (a) to the second sub-pixel (b), relative to an orthographic projection of a boundary between a top surface of the light emitting unit of the second sub-pixel (31b) and the first pixel defining layer (32) between the light emitting units of the first sub-pixel (a) and the second sub-pixel (b) on the base substrate (4), an orthographic projection of a boundary between a bottom surface of the second wavelength converting unit (11b) and the second pixel defining layer (12) between the wavelength converting units of the first sub-pixel and the second sub-pixel (11a, 11b) on the base substrate (4) is shifted by d4 2 , wherein in all light which is incident into the transparent spacing layer from the top surface of the light emitting unit in the first sub-pixel (31a) and may reach a top surface of the transparent spacing layer (2), light with an emergence angle of α1 or more has an intensity proportion of x1% or less, wherein x 1 % = p 1 x (ra/rb), wherein 0 < p 1 ≤ 5%, wherein when light starting from a bottom surface of the transparent spacing layer (2) has an emergence angle of α1, a projection of a light path thereof through the transparent spacing layer on the base substrate (4) has a length less than or equal to d2 + d4 2 .
  2. The display panel according to claim 1, wherein p1 ≤ 2%.
  3. The display panel according to claim 1, wherein when the light starting from the bottom surface of the transparent spacing layer has an emergent angle of α 1 , a difference between the length of the projection of the light path thereof through the transparent spacing layer on the base substrate and d2 + d4 2 is less than or equal to 5 µm.
  4. The display panel according to claim 1, wherein in a direction from the second sub-pixel to the first sub-pixel, relative to an orthographic projection of a boundary between a top surface of the light emitting unit of the first sub-pixel and the first pixel defining layer between the light emitting units of the first sub-pixel and the second sub-pixel on the base substrate, an orthographic projection of a boundary between a bottom surface of the first wavelength converting unit and the second pixel defining layer between the wavelength converting units of the first sub-pixel and the second sub-pixel on the base substrate is shifted by d4 1 , wherein in all light which is incident into the transparent spacing layer from the top surface of the light emitting unit in the second sub-pixel and may reach a top surface of the transparent spacing layer, light with an emergence angle of α 2 or more has an intensity proportion of x2% or less, wherein x2% = p2 × (rb/ra), wherein 0 < p2 ≤ 5%, wherein when light from a bottom surface of the transparent spacing layer has an emergence angle of α 2 , a projection of a light path thereof through the transparent spacing layer on the base substrate has a length less than or equal to d2 + d4 1 .
  5. The display panel according to claim 4, wherein p2 = p1.
  6. The display panel according to claim 4, wherein d4 1 = d4 2 .
  7. The display panel according to claim 4, wherein |d4 1 | ≤ 5 µm, and |d4 2 | ≤ 5 µm.
  8. The display panel according to claim 1, wherein the transparent spacing layer has a thickness of d1, and comprises m sub-layers stacked bottom up, wherein an i-th sub-layer has a thickness of L i and a refractive index of n i , wherein i is between 1 and m, parameters meet the following equations: d 1 = ∑ i = 1 m L i d 2 + d 4 2 = ∑ i = 1 m L i tan θ 1 i , wherein i is an integer between 1 and m, n i sinθ 1i is a constant, and θ 11 = α 1 .
  9. The display panel according to claim 1, wherein the sub-pixels arranged in an array further comprise a third sub-pixel adjacent to the first sub-pixel, wherein in the third sub-pixel, one light emitting unit in the light emitting layer and one transparent color filtering unit in the wavelength converting layer are comprised, and the light emitting unit and the transparent color filtering unit are stacked and spaced apart by the transparent spacing layer, the light emitting units of the first sub-pixel and the third sub-pixel are spaced apart by the first pixel defining layer in the light emitting layer, and have a top surface spacing of d5, the transparent color filtering unit does not convert a wavelength of a light emitted by the light emitting unit, and has a luminance change ratio of rc on light emitted by the light emitting unit, and the wavelength converting unit of the first sub-pixel and the transparent color filtering unit of the third sub-pixel are spaced apart by the second pixel defining layer in the wavelength converting layer, in a direction from the third sub-pixel to the first sub-pixel, relative to an orthographic projection of a boundary between a top surface of the light emitting unit of the first sub-pixel and the first pixel defining layer between the light emitting units of the first sub-pixel and the third sub-pixel on the base substrate, an orthographic projection of a boundary between a bottom surface of the first wavelength converting unit and the second pixel defining layer between the wavelength converting unit of the first sub-pixel and the transparent color filtering unit of the third sub-pixel on the base substrate is shifted by d4 3 , wherein in all light which is incident into the transparent spacing layer from the top surface of the light emitting unit in the third sub-pixel and may reach a top surface of the transparent spacing layer, light with an emergence angle of α 3 or more has an intensity proportion of x3% or less, wherein x3% = p3 × (rc/ra), wherein 0 < p3 ≤ 5%, wherein when light starting from a bottom surface of the transparent spacing layer has an emergence angle of α 3 , a projection of a light path thereof through the transparent spacing layer on the base substrate has a length less than or equal to d5 + d4 3 preferably, the light emitting units emit blue light, the third sub-pixel is a blue sub-pixel, the first sub-pixel is a red sub-pixel, and the second sub-pixel is a green sub-pixel .
  10. The display panel according to claim 9, wherein ra is within [110%, 180%], rb is within [25%, 70%], and rc is within [60%, 85%].
  11. The display panel according to claim 1, wherein the transparent spacing layer comprises a first inorganic layer, an organic layer and a second inorganic layer stacked bottom up, wherein optionally, the first inorganic layer is a SiNx layer, the second inorganic layer is a SiONx layer or an Al 2 O 3 layer, and the organic layer is an epoxy resin layer or a polyacrylic resin layer, optionally, the organic layer has a thickness in a range from 4 to 8 µm, optionally, the organic layer has a thickness in a range from 0.3 to 0.6 µm.
  12. The display panel according to claim 1, wherein a top surface of the second pixel defining layer has a width less than that of a bottom surface thereof.
  13. The display panel according to claim 1, wherein the second pixel defining layer comprises a main body and a coating layer on a side wall of the main body, wherein optionally, the coating layer is an ink permeation preventing layer, optionally, the coating layer comprises a light reflecting material or a light absorbing material, optionally, a material for the coating layer is metal.
  14. The display panel according to claim 13, wherein the coating layer has a lateral extending portion away from the main body at its bottom which covers the surface of the transparent spacing layer.
  15. The display panel according to claim 14, wherein the main body has an undercut covered by the lateral extending portion of the coating layer, wherein the undercut preferably has a depth in a range from 4 to 9 µm.

Description

TECHNICAL FIELD The present disclosure relates to the technical field of display, and particularly to a display panel, a manufacture method therefor and a display device. BACKGROUND Organic light emitting display (OLED) as an mainstream display technology has occupied the market of mobile display, and also attracts significant interest of the manufactures in the display application such as TV. From the perspective of the manner for displaying colors, the technical route of OLED is mainly divided into two types. One is to use organic light emitting materials which emit different colors respectively (such as red light emitting material, green light emitting material and blue light emitting material) to form sub-pixels with different colors, which is called the RGB type. The RGB type has a high color gamut, and has occupied the market of middle and small size applications. However, it cannot be scaled up to large area because it is limited by the fine metal mask (FMM) process. Although the RGB type where RGB OLEDs are printed by ink jet is a potential technology for large size OLED, the color gamut value is not high enough due to the limitation on the research and development of the OLED material obtained by a solution process. The other is to use a single color OLED as a backlight emitting unit in combination with color films to achieve the color display, which is called the backlight-color film type. The process in which a white backlight is combined with color films has been one of the mainstream technologies for large size OLED because it may be achieved by deposition on the entire surface with an open mask. In the white backlight-color film technology, the color films function to filter light with wavelengths other than that for the desired color from the white light. The color gamut of the color films directly limits the color gamut range of the large size OLED product. A technology where a wavelength converting component is used to change the color of the light emitted by a single color OLED to achieve the color display has emerged. For example, a technology combining a blue OLED with quantum dots (QDs) has been proposed in related art, where the blue OLED is used as a light source to cooperate with the QDs to down-convert blue light into red light and green light, thereby achieving the color display. Such a technology is called the QD-OLED. The development of the display panel comprising a wavelength converting component still faces many practical technical challenges. There is still a need for improving the display panel comprising a wavelength converting component, in particular a QD conversion layer. WO 2020/230989 A1 discloses a display device, in which the light generated in a sub-pixel is prevented from arriving at the adjacent sub-pixel by a pixel defining layer. WO 02/15292 A2 also discloses a display device, in which the light generated in a sub-pixel is prevented from arriving at the adjacent sub-pixel by a pixel defining layer. SUMMARY The present disclosure provides a display panel, comprising: a light emitting layer on a base substrate,a transparent spacing layer on the light emitting layer, anda wavelength converting layer on the transparent spacing layer,wherein the display panel comprises sub-pixels arranged in an array, the sub-pixels arranged in an array comprise a first sub-pixel and a second sub-pixel adjacent to each other, wherein in each of the first sub-pixel and the second sub-pixel one light emitting unit in the light emitting layer and one wavelength converting unit in the wavelength converting layer are comprised, and the light emitting unit and the wavelength converting unit are stacked and spaced apart by the transparent spacing layer,the light emitting units of the first sub-pixel and the second sub-pixel are spaced apart by a first pixel defining layer in the light emitting layer, and have a top surface spacing of d2,the wavelength converting unit of the first sub-pixel is a first wavelength converting unit which has a luminance change ratio of ra on light emitted by the light emitting unit, and the wavelength converting unit of the second sub-pixel is a second wavelength converting unit which has a luminance change ratio of rb on light emitted by the light emitting unit, and the wavelength converting units of the first sub-pixel and the second sub-pixel are spaced apart by a second pixel defining layer in the wavelength converting layer,wherein the transparent spacing layer in the first sub-pixel and the transparent spacing layer in the second sub-pixel are continuous between the first pixel defining layer and the second pixel defining layer,in a direction from the first sub-pixel to the second sub-pixel, relative to an orthographic projection of a boundary between a top surface of the light emitting unit of the second sub-pixel and the first pixel defining layer between the light emitting units of the first sub-pixel and the second sub-pixel on the base substrate, an o