CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a national stage of International Application No. PCT/CN2020/070430 filed on Jan. 6, 2020, which claims priority to Chinese Patent Application No. 201910208131.1 filed on Mar. 19, 2019. The disclosures of these applications are hereby incorporated by reference in their entirety.

FIELD

The present disclosure relates generally to the field of display technologies, and more specifically to a display panel, a method for fabricating the same, and a display apparatus.

BACKGROUND

With the rapid development of display technology, electronic displays have entered all aspects of people's lives. In particular, the popular use of smart terminals has placed an ever-increasing demand on the quality and performance of displays.

SUMMARY

Various embodiments of the present disclosure provide a display panel, a manufacturing method thereof, and a display apparatus.

In a first aspect, a display panel is provided, including:

a plurality of light emitting units each having a light emitting side and a back side;

a transparent substrate disposed over the light emitting side of the light emitting unit;

a transparent film disposed over a side of the transparent substrate opposing the light emitting unit,

wherein:

the transparent film has an effective refractive index smaller than a refractive index of the transparent substrate; and

the transparent film has a position-dependent refractive index progressively smaller along a light emitting direction from the light emitting unit.

In some embodiments:

the transparent film is patterned as a plurality of convex structures protruding away from the plurality of light emitting units; and

the plurality of convex structures and the plurality of light emitting units have a one-to-one correspondence.

In some embodiments, each of the plurality of convex structures is configured to have a centrally symmetric shape with respect to an equivalent illuminating center point of a corresponding light emitting unit.

In some embodiments, each of the plurality convex structures is configured to be a spherical cap that is smaller or equal to a hemisphere or a conic shape.

In some embodiments, each of the plurality convex structures includes at least a first transparent film sublayer and a second transparent film sublayer, with the first sublayer being closer to the plurality of light emitting units and the second sublayer being farther away from the light emitting units.

In some embodiments, the first sublayer includes magnesium fluoride, and the second sublayer includes cryolite.

In some embodiments:

the first sublayer has an edge with a plane section forming an angle with the surface plane of the transparent substrate that is equal to or greater than 20 degrees; and

the second sublayer has an edge with a plane section forming an angle with the surface plane of the transparent substrate that is equal to or greater than 20 degrees.

In some embodiments, the transparent film has a gradually varying refractive index through doping or through a gradual variation in a material composition along the light emitting direction from the light emitting unit.

In some embodiments, the transparent film has stepped refractive indices through stepped doping or through stepped variation in a material composition along the light emitting direction from the light emitting unit.

In some embodiments:

the transparent film includes a plurality of sublayers; and

each of the plurality of sublayers has a refractive index progressively smaller than a refractive index of a previous layer that is closer to the light emitting unit.

In some embodiments, the plurality of sublayers includes:

a first layer proximal to the light emitting unit and having a first refractive index of 1.4; and

a second layer over the first layer and having a second refractive index of 1.33.

In some embodiments:

the first layer includes MgF2; and

the second layer includes cryolite.

In some embodiments:

the first sublayer has an edge with a plane section forming an angle with the surface plane of the transparent substrate that is equal to or greater than 20 degrees; and

the second sublayer has an edge with a plane section forming an angle with the surface plane of the transparent substrate that is equal to or greater than 20 degrees.

In some embodiments:

each of the plurality of light emitting units includes a top emitting organic light-emitting diode (OLED);

the display panel further includes: a base substrate and a protective cover that functions as the transparent substrate; and

each of the plurality of light emitting units is disposed between the base substrate and the protective cover.

In some embodiments:

each of the plurality of light emitting units includes a bottom emitting organic light-emitting diode (OLED);

the display panel further includes: a base substrate and a protective cover that functions as the transparent substrate; and

each of the plurality of light emitting units is disposed between the base substrate and the protective cover.

In another aspect, a display apparatus is provided, including the display panel described above, and further including a control circuit including an array of thin-film transistors (TFTs).

In another aspect, a method of manufacturing a display panel is provided, including:

forming a plurality of light emitting units and a transparent substrate disposed on a light emitting side of the plurality of light emitting units;

disposing a transparent film on a side of the transparent substrate that is opposing the plurality of light emitting units, wherein the transparent film includes a plurality of sublayers; and

each sublayer of the transparent film has a refractive index smaller than that of the transparent substrate, and each sublayer's refractive index is progressively smaller than the previous sublayer ordered in a light-emitting direction.

In some embodiments, the method further includes:

forming the plurality of sublayers one layer at a time, and patterning each sublayer into a plurality of convex structures after each sublayer is formed, wherein each of the plurality of convex structures corresponds to a light emitting unit in a one-to-one correspondence.

In some embodiments, the method further includes:

forming the sublayers one layer at a time, and patterning the entire transparent film to form a plurality of convex structures in a single patterning process after all the sublayers are formed, wherein each of the plurality of convex structures correspond to each light emitting units in a one-to-one correspondence.

In some embodiments, the method further includes:

forming an anode over the transparent substrate;

forming a pixel defining layer over the anode.

forming an organic functional layer over the anode at which the pixel defining layer is formed;

forming a cathode over the organic functional layer;

wherein the organic functional layer corresponds to a light-emitting area at the light-emitting side;

depositing, with a chemical vapor deposition (CVD) process, the transparent film including a MgF2 film sublayer, and a cryolite (n=1.33) film sublayer;

performing exposure with a variable transmittance mask; and

forming a convex structure over surface of the cryolite film sublayer, having an edge with a plane section forming an angle with the surface plane of the transparent substrate that is equal to or greater than 20 degrees.

Other embodiments may become apparent in view of the following descriptions and the attached drawings.

