Display substrate and display device

Patent metadata

Field	Value
Publication number	US-12593603-B2
Application number	US-202117794628-A
Country	US
Kind code	B2
Filing date	Aug 30, 2021
Priority date	Aug 30, 2021
Publication date	Mar 31, 2026
Grant date	Mar 31, 2026

Abstract

A display substrate includes a light emitting element disposed on a base substrate, and a light dimming structure layer and an anti-reflection layer stacked sequentially at a light exiting side of the light emitting element, wherein the light dimming structure layer includes a polarizing film layer configured to convert at least a portion of light emitted by the light emitting element incident onto the polarizing film layer into circularly polarized light with a set rotational direction to pass through the polarizing film layer; the anti-reflection layer includes a phase retarder and a linear polarizer which are stacked sequentially along a direction away from the base substrate, the phase retarder being configured to convert the circularly polarized light passing through the polarizing film layer into linearly polarized light, a polarization direction of which is parallel to a direction of a light transmission axis of the linear polarizer.

First claim

The invention claimed is:

1 . A display substrate, comprising a light emitting element disposed on a base substrate, and a light dimming structure layer and an anti-reflection layer sequentially stacked at a light exiting side of the light emitting element,
wherein the light dimming structure layer comprises a polarizing film layer configured to convert at least a portion of light which is emitted by the light emitting element and incident onto the polarizing film layer into circularly polarized light with a set rotational direction to pass through the polarizing film layer and a composite structure layer disposed at one side of the polarizing film layer facing the light emitting element, wherein the composite structure layer comprises a capping layer and an encapsulation layer; and the anti-reflection layer comprises a phase retarder and a linear polarizer which are stacked sequentially along a direction away from the base substrate, wherein the phase retarder is configured to convert the circularly polarized light passing through the polarizing film layer into linearly polarized light, a polarization direction of the linearly polarized light is parallel to a direction of a light transmission axis of the linear polarizer, wherein the polarizing film layer comprises a cholesteric liquid crystal layer, and the cholesteric liquid crystal layer and the light emitting element satisfy |Ne−No|×P≥FWHM×2 and |(No+Ne)×P−2λ|≤3×FWHM, wherein No is a refractive index of cholesteric liquid crystal parallel to an optical axis direction; Ne is a refractive index of the cholesteric liquid crystal perpendicular to the optical axis direction; P is a pitch of the cholesteric liquid crystal; λ is the peak wavelength of the emission spectrum of the light emitting element; and FWHM is a peak width at half height of an emission spectrum of the light emitting element.

2 . The display substrate according to claim 1 , wherein the light emitting element comprises an anode, a light emitting layer and a cathode which are stacked sequentially along the direction away from the base substrate; and
the polarizing film layer is further configured to convert another portion of the light which is emitted by the light emitting element and incident onto the polarizing film layer into circularly polarized light with a rotational direction opposite to the set rotational direction and reflect the light, and the circularly polarized light with the rotational direction opposite to the set rotational direction reflected off the polarizing film layer is converted into circularly polarized light with a same rotational direction as the set rotational direction after it is reflected off the cathode, and the circularly polarized light with the same rotational direction as the set rotational direction is able to pass through the polarizing film layer.

3 . The display substrate according to claim 1 , wherein the light emitting element comprises a red light emitting element which satisfies FWHM=34 nm and λ=615 nm; and
the cholesteric liquid crystal layer comprises a first cholesteric liquid crystal which is able to convert at least a portion of red light which is emitted by the red light emitting element and incident onto the cholesteric liquid crystal layer into circularly polarized light with the set rotational direction to pass through the cholesteric liquid crystal layer, and the first cholesteric liquid crystal satisfies P=400 nm, Ne=1.62 and No=1.44.

4 . The display substrate according to claim 1 , wherein a refractive index of the composite structure layer increases and decreases alternately along the direction away from the base substrate.

5 . The display substrate according to claim 4 , wherein the composite structure layer comprises n film layers stacked sequentially along the direction away from the base substrate, and a farthest film layer away from the base substrate in the composite structure layer is the n-th film layer, with n being an integer greater than or equal to 2; and
both a refractive index of the (n−1)-th film layer and a refractive index of the polarizing film layer are lower than a refractive index of the n-th film layer, or both the refractive index of the (n−1)-th film layer and the refractive index of the polarizing film layer are higher than the refractive index of the n-th film layer.

6 . The display substrate according to claim 4 , wherein the composite structure layer comprises n film layers stacked sequentially along the direction away from the base substrate, with n being an integer greater than or equal to 2; and
a refractive index of one of any two adjacent film layers of the n film layers is 1.3 to 1.7, and a refractive index of the other one of the two adjacent film layers is 1.7 to 2.3.

7 . The display substrate according to claim 6 , wherein a refractive index of the polarizing film layer is 1.3 to 1.7.

8 . The display substrate according to claim 6 , wherein a refractive index of a film layer of the n film layers which is closest to the base substrate is 1.7 to 2.3.

9 . The display substrate according to claim 4 , wherein the composite structure layer comprises a first film layer, a second film layer, a third film layer, a fourth film layer and a fifth film layer that are stacked sequentially along the direction away from the base substrate; and
a thickness of the first film layer is 50 nm to 150 nm, a thickness of the second film layer is 40 nm to 100 nm, a thickness of the third film layer is 500 nm to 2000 nm, a thickness of the fourth film layer is 5000 nm to 20000 nm, and a thickness of the fifth film layer is 400 nm to 1000 nm.

10 . The display substrate according to claim 4 , wherein the composite structure layer comprises a first film layer, a second film layer, a third film layer, a fourth film layer and a fifth film layer that are stacked sequentially along the direction away from the base substrate; and
a material of the first film layer is an aromatic amine or azine organic material, a material of the second film layer is lithium fluoride or silicon dioxide, a material of the third film layer is silicon nitride or silicon oxynitride, a material of the fourth film layer is a resin material or silicon dioxide, and a material of the fifth film layer is silicon nitride or silicon oxynitride; or materials of both the first film layer and the second film layer are aromatic amine or azine organic material, a material of the third film layer is silicon nitride or silicon oxynitride, a material of the fourth film layer is a resin material or silicon dioxide, and a material of the fifth film layer is silicon nitride or silicon oxynitride; or a material of the first film layer is an aromatic amine or azine organic material, materials of both the second film layer and the third film layer are silicon nitride or silicon oxynitride, a material of the fourth film layer is a resin material or silicon dioxide, and a material of the fifth film layer is silicon nitride or silicon oxynitride.

11 . The display substrate according to claim 9 , wherein a thickness of the polarizing film layer is 1 μm to 10 μm.

12 . The display substrate according to claim 4 , wherein the polarizing film layer is attached to the surface of the composite structure layer facing away from the base substrate by an optically clear adhesive, a thickness of the optically clear adhesive is 10 μm to 30 μm, and a difference between a refractive index of the optically clear adhesive and a refractive index of the polarizing film layer is no greater than 0.15.

13 . The display substrate according to claim 2 , wherein reflectivity of the cholesteric liquid crystal layer to natur

Assignees

• Boe Technology Group Co Ltd

Inventors

• Zhang Xiaojin
• Wang Siqi
• Sun Haiyan

Classifications

• H10K85/111

  comprising aromatic, heteroaromatic, or aryl chains, e.g. polyaniline, polyphenylene or polyphenylene vinylene · CPC title

• H10K2102/351

  Thickness · CPC title

• H10K59/879

  comprising refractive means, e.g. lenses · CPC title

• H10K59/50

  OLEDs integrated with light modulating elements, e.g. with electrochromic elements, photochromic elements or liquid crystal elements · CPC title

• H10K59/8791 Primary

  Arrangements for improving contrast, e.g. preventing reflection of ambient light · CPC title