TWI806685B - Display device - Google Patents

Abstract

A display device includes a substrate, a first light-emitting diode, an encapsulant and a first Fresnel lens. The first light emitting diode is located on the substrate. The encapsulant covers the first light emitting diode. The first Fresnel lens is located on the encapsulant and overlaps the first light emitting diode. The width of the first Fresnel lens is 4 times to 10times the width of the first light emitting diode.

Description

display device

The present invention relates to a display device, and in particular to a display device including a Fresnel lens.

Light-emitting diode is a kind of electroluminescent semiconductor element, which has the advantages of high efficiency, long life, not easy to break, fast response speed and high reliability. Micro-LED displays and OLED displays are very competitive display devices at present. Compared with liquid crystal displays, micro light emitting diode displays and organic light emitting diode displays are thinner because they do not require a backlight module. In order to further improve the luminous efficiency of micro light emitting diode displays and organic light emitting diode displays, many manufacturers are devoting themselves to research and development to avoid the problem of total reflection of the light emitted by the light emitting diodes inside the display inside the display.

The invention provides a display device, which has the advantages of high light extraction efficiency and thin thickness.

At least one embodiment of the invention provides a display device. The display device includes a substrate, a first light emitting diode, an encapsulation material and a first Fresnel lens. The first light emitting diode is located on the substrate. The packaging material covers the first light emitting diode. The first Fresnel lens is located on the packaging material and overlaps the first light emitting diode. The width of the first Fresnel lens is 4 times to 10 times that of the first light emitting diode.

FIG. 1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

Please refer to FIG. 1 , the display device 1 includes a substrate 100 , a first light emitting diode 112 , an encapsulation material 120 and a first Fresnel lens (Fresnel lens) 132 . In this embodiment, the display device 1 further includes a second light emitting diode 114, a third light emitting diode 116, a second Fresnel lens 134, a third Fresnel lens 136, a reflective substrate 140, and a conductive connection structure 150 , black matrix 160 , support structure 170 and cover plate 180 .

In this embodiment, the substrate 100 is an active device substrate. For example, the substrate 100 includes a base, a plurality of signal lines and a plurality of active devices formed on the base, the aforementioned base being, for example, a transparent base.

The first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 are located on the substrate 100 . The first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 are, for example, micro light emitting diodes or organic light emitting diodes. In some embodiments, the width w1 of the first light emitting diode 112 , the width w2 of the second light emitting diode 114 , and the width w3 of the third light emitting diode 116 range from 18 μm to 381 μm.

When the first light emitting diode 112, the second light emitting diode 114 and the third light emitting diode 116 are miniature light emitting diodes, the first light emitting diode 112, the second light emitting diode 114 and the third light emitting diode The light emitting diode 116 is electrically connected to the signal line and/or the active device in the substrate 100 through the conductive connection structure 150 . The conductive connection structure 150 is, for example, solder, anisotropic conductive glue or other suitable materials. Although in FIG. 1 , the conductive connection structure 150 completely covers the substrate 100 , the present invention is not limited thereto. In other embodiments, the conductive connection structure 150 only partially covers the substrate 100 . In other embodiments, the first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 are organic light emitting diodes, and can be electrically connected to the organic light emitting diode without passing through the conductive connection structure 150 . The signal lines and/or active components in the substrate 100, for example, the first light-emitting diode 112, the second light-emitting diode 114, and the third light-emitting diode 116 are directly formed on the electrodes in the substrate 100, so that The first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 are electrically connected to the signal line and/or the active device in the substrate 100 .

The black matrix 160 is located on the substrate 100 and surrounds the first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 . In this embodiment, the black matrix 160 is formed on the conductive connection structure 150 , but the invention is not limited thereto. In other embodiments, the conductive connection structure 150 is only disposed between the first light emitting diode 112 and the substrate 100 , between the second light emitting diode 114 and the substrate 100 and between the third light emitting diode 116 and the substrate 100 Between, and the black matrix 160 is not formed on the conductive connection structure 150 . The black matrix 160 is, for example, black resin, black photoresist, material that absorbs light in a specific band of the spectrum, black colloid, metal oxide, metal nitride or other light-absorbing materials.

The packaging material 120 covers the first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 . In this embodiment, the packaging material 120 covers the first light emitting diode 112 , the second light emitting diode 114 and the third light emitting diode 116 . The thickness t1 of the packaging material 120 is 8 microns to 500 microns. Within the aforementioned thickness range, the encapsulation material 120 can have a relatively flat surface 120 a without greatly affecting the overall thickness of the device.

In some embodiments, the encapsulation material 120 optionally also covers the black matrix 160 . The packaging material 120 is, for example, silicone, epoxy, optical clear adhesive or other materials. In some embodiments, the refractive index of the encapsulation material 120 is 1.5 to 1.6.

The first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 are located on the packaging material 120 . In some embodiments, the first Fresnel lens 132, the second Fresnel lens 134, and the third Fresnel lens 136 are formed on the surface 120a of the packaging material 120, and the first Fresnel lens 132, the second Fresnel lens The Nell lens 134 , the third Fresnel lens 136 and the packaging material 120 may comprise the same or different materials. In this embodiment, the first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 are separated from each other. In other embodiments, the first Fresnel lens 132 , the second Fresnel lens 134 , the third Fresnel lens 136 and the encapsulation material 120 comprise the same material. In other embodiments, the first Fresnel lens 132 is integrally formed with the encapsulation material 120 , the second Fresnel lens 134 is integrally formed with the encapsulation material 120 , and the third Fresnel lens 136 is integrally formed with the encapsulation material 120 .

The first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 are, for example, silicone, epoxy, optical clear adhesive or other materials. In some embodiments, the refractive index of the first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 is 1.5 to 1.6. The refractive index of the first Fresnel lens 132, the second Fresnel lens 134, and the third Fresnel lens 136 is approximately equal to the refractive index of the packaging material 120 (for example, approximately equal to 1.5), thereby reducing the refraction of light on the surface 120a. probability.

The first Fresnel lens 132 overlaps the first LED 112 . The second Fresnel lens 134 overlaps the second LED 114 . The third Fresnel lens 136 overlaps the third light emitting diode 116 . In this embodiment, in the direction D1 perpendicular to the substrate 100, the center of the first Fresnel lens 132, the center of the second Fresnel lens 134 and the center of the third Fresnel lens 136 are respectively overlapped with the first The center of the light-emitting diode 112 , the center of the second light-emitting diode 114 and the center of the third light-emitting diode 116 increase the light extraction efficiency of the display device 1 . In this embodiment, the black matrix 120 does not overlap the first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 .

The width w4 of the first Fresnel lens 132 is 4 times to 10 times the width w1 of the first light emitting diode 112 . The width w5 of the second Fresnel lens 134 is 4 times to 10 times the width w2 of the second light emitting diode 114 . The width w6 of the third Fresnel lens 136 is 4 times to 10 times the width w3 of the third light emitting diode 116 . In this embodiment, the widths w4 , w5 , w6 are greater than or equal to 4 times of the widths w1 , w2 , w3 , which helps to increase the light extraction efficiency of the display device 1 . However, in order to avoid excessive reflection, the widths w4, w5, w6 are not greater than 10 times the widths w1, w2, w3.

The curvature radius of the first Fresnel lens 132 is 45%˜55% of the width w4 of the first Fresnel lens 132 . The radius of curvature of the second Fresnel lens 134 is 45%˜55% of the width w5 of the second Fresnel lens 132 . The radius of curvature of the third Fresnel lens 136 is 45%˜55% of the width w6 of the third Fresnel lens 136 .

The distance x1 from the top surface 132 a of the first Fresnel lens 132 to the first light-emitting diode 112 is 8 μm to 500 μm. The distance x2 from the top surface 134 a of the second Fresnel lens 134 to the second LED 114 is 8 micrometers to 500 micrometers. The distance x3 from the top surface 136 a of the third Fresnel lens 136 to the third light-emitting diode 116 is 8 μm to 500 μm.

The support structure 170 is located on the encapsulation material 120 . The cover 180 overlaps the substrate 100 , and the supporting structure 170 is located between the substrate 100 and the cover 180 . The top surface 170a of the support structure 170 is closer to the cover plate 180 than the top surface 132a of the first Fresnel lens 132, the top surface 134a of the second Fresnel lens 134, and the top surface 136a of the third Fresnel lens 136. Therefore, the support structure 170 helps to prevent the cover plate 180 from squeezing the first Fresnel lens 132 , the second Fresnel lens 134 and the third Fresnel lens 136 .

Based on the above, the width w4 of the first Fresnel lens 132 is greater than or equal to four times the width w1 of the first light-emitting diode 112 , which helps to increase the light extraction efficiency of the display device 1 .

FIG. 2 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. It must be noted here that the embodiment in FIG. 2 follows the component numbers and part of the content of the embodiment in FIG. 1 , wherein the same or similar numbers are used to denote the same or similar components, and the description of the same technical content is omitted. For the description of the omitted part, reference may be made to the foregoing embodiments, and details are not repeated here.

Please refer to FIG. 2 , in this embodiment, the top surface of the Fresnel lens 130 includes a central circular protrusion C, a first annular protrusion R1 surrounding the circular protrusion C, and a first annular protrusion R1 surrounding the first annular protrusion C. The second annular protrusion R2 of the protrusion R1, the third annular protrusion R3 surrounding the second annular protrusion R2, the fourth annular protrusion R4 surrounding the third annular protrusion R3, and the fifth annular protrusion R4 surrounding the fourth annular protrusion R4 Ring raised R5. In this embodiment, the Fresnel lens 130 includes five annular protrusions, but the present invention is not limited thereto, and the number of annular protrusions can be adjusted according to actual needs.

In some embodiments, the width Z3 of the circular protrusion C is greater than the width Z1 of the light emitting diode 110 , so that the Fresnel lens 130 is easier to align with the light emitting diode 110 .

3 is a line diagram of the width Z2 of the Fresnel lens 130 (please refer to FIG. 2 ) and the light extraction efficiency of the display device according to an embodiment of the present invention. Taking the width Z1 of the light emitting diode 110 as 130 microns as an example, When the width Z2 of the Fresnel lens 130 exceeds ten times (1300 microns) the width Z1 of the light-emitting diode 110 , the display device has excellent light extraction efficiency.

Table 1 shows the relationship between the width Z2 of the Fresnel lens 130 , the radius of curvature of the Fresnel lens 130 and the light extraction efficiency of the display device (taking green light as an example). Table 1 Fresnel lens width Radius of curvature of a Fresnel lens Light efficiency 500 microns 250 microns 50.08% 1500 microns 750 microns 76.09% 3000 microns 1050 microns 77.16% 1500 microns 77.29% 4000 microns 2000 microns 77.48%

It can be known from Table 1 that when the radius of curvature of the Fresnel lens 130 is 50% of the width Z2 of the Fresnel lens 130 , the display device has better light extraction efficiency.

FIG. 4 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. It must be noted here that the embodiment in FIG. 4 follows the component numbers and part of the content of the embodiment in FIG. 1 , where the same or similar numbers are used to denote the same or similar components, and the description of the same technical content is omitted. For the description of the omitted part, reference may be made to the foregoing embodiments, and details are not repeated here.

The main difference between the display device 2 in FIG. 4 and the display device 1 in FIG. 1 is that the display device 2 further includes a retaining wall structure 200 .

In this embodiment, the barrier structure 200 surrounds the first LED 112 , the second LED 114 and the third LED 116 . The packaging material 120 fills the openings O of the wall structure 200 and covers the first LED 112 , the second LED 114 and the third LED 116 . On the direction D1 perpendicular to the substrate 100, the top surface 132a of the first Fresnel lens 132, the top surface 134a of the second Fresnel lens 134, and the top surface 136a of the third Fresnel lens 136 overlap the wall structure The sidewall of the opening O of the 200 and part of the top surface of the retaining wall structure 200 . The retaining wall structure 200 covers the black matrix 160 .

To sum up, in the display device of the present invention, the width of the Fresnel lens is greater than or equal to four times the width of the light-emitting diode, thereby effectively improving the light extraction efficiency of the display device.

1, 2: display device 100: Substrate 112: the first light-emitting diode 114: the second light-emitting diode 116: the third light-emitting diode 120: Encapsulation material 120a, 132a, 134a, 136a, 170a: surfaces 132: The first Fresnel lens 134: Second Fresnel lens 136: The third Fresnel lens 140: reflective substrate 150: Conductive connection structure 160: black matrix 170:Support structure 180: cover plate 200: retaining wall structure C: prototype bump D1: Direction O: open R1: first ring raised R2: second ring raised R3: third ring raised R4: fourth ring raised R5: fifth ring raised t1: Thickness w1, w2, w3, w4, w5, w6, Z1, Z2, Z3: width x1, x2, x3: distance

FIG. 1 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of a display device according to an embodiment of the present invention. FIG. 3 is a broken line diagram of the width of the Fresnel lens and the light extraction efficiency of the display device according to an embodiment of the present invention. FIG. 4 is a schematic cross-sectional view of a display device according to an embodiment of the present invention.

1: Display device

100: Substrate

112: the first light-emitting diode

114: the second light-emitting diode

116: the third light-emitting diode

120: Encapsulation material

120a, 132a, 134a, 136a, 170a: surfaces

132: The first Fresnel lens

134: Second Fresnel lens

136: The third Fresnel lens

140: reflective substrate

150: Conductive connection structure

160: black matrix

170:Support structure

180: cover plate

D1: Direction

t1: Thickness

w1, w2, w3, w4, w5, w6: width

x1, x2, x3: distance

Claims (10)

A display device comprising: a substrate; a first light emitting diode located on the substrate; an encapsulation material covering the first light emitting diode; A first Fresnel lens, located on the encapsulation material and overlapping the first light-emitting diode, wherein the width of the first Fresnel lens is 4 times to 10 times the width of the first light-emitting diode times; a second light emitting diode located on the substrate, and the packaging material covers the second light emitting diode; A second Fresnel lens, located on the encapsulation material and overlapping the second light-emitting diode, wherein the width of the second Fresnel lens is 4 times to 10 times the width of the second light-emitting diode times, and the second Fresnel lens is separated from the first Fresnel lens; and A black matrix is located on the substrate and surrounds the first light-emitting diode and the second light-emitting diode, wherein the black matrix does not overlap the first Fresnel lens and the second Fresnel lens. The display device according to claim 1, wherein the packaging material covers the black matrix. The display device according to claim 1, wherein the packaging material covers the first light-emitting diode and the second light-emitting diode, and the first Fresnel lens and the second Fresnel lens are located at the on one surface of the encapsulation material. The display device according to claim 1, wherein the first Fresnel lens, the second Fresnel lens and the packaging material have the same material, and the refractive index of the first Fresnel lens is 1.5. The display device according to claim 1, wherein the radius of curvature of the first Fresnel lens is 45% to 55% of the width of the first Fresnel lens, and the radius of curvature of the second Fresnel lens is the 45%~55% of the width of the second Fresnel lens. The display device according to claim 1, wherein the width of the first light emitting diode and the width of the second light emitting diode are 18 microns to 381 microns. The display device as claimed in item 1, wherein the distance from the top surface of the first Fresnel lens to the first light-emitting diode is 8 microns to 500 microns, and the distance from the top surface of the second Fresnel lens to the The distance between the second light emitting diodes is 8 microns to 500 microns. The display device as claimed in item 1, wherein the top surface of the first Fresnel lens includes a circular protrusion in the center, a first annular protrusion surrounding the circular protrusion, a first annular protrusion surrounding the first A second annular protrusion of the annular protrusion and a third annular protrusion surrounding the second annular protrusion, wherein the width of the circular protrusion is greater than the width of the first light-emitting diode. The display device as described in claim 1, further comprising: A conductive connection structure electrically connected to the first light-emitting diode and the second light-emitting diode, wherein the black matrix is located on the conductive connection structure. The display device as described in claim 1, further comprising: A retaining wall structure surrounding the first light emitting diode and the second light emitting diode, wherein the packaging material fills at least one opening of the retaining wall structure and covers the first light emitting diode and the second light emitting diode diode, and the wall structure covers the black matrix.

Images