# US 12,765,228 B2 · Electroluminescent display device

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- Number: US 12,765,228 B2
- Document ID: US12765228B2
- Status: Granted
- Kind: B2
- Application number: 18/090,226
- Filed: 2022-12-28
- Published: 2023-06-29
- Granted: 2026-10-13
- Earliest claimed: 2021-12-28
- Assignees: LG Display Co., Ltd.
- Applicants: LG Display Co., Ltd.
- Inventors: Seongho Kang; Jeongoh Kim; MyungJae Yoo; Geumyoung Lee
- Web page: https://patentgrep.com/patent/US12765228B2

## CPC

- H10K 59/873: {Encapsulations}
- H10K 59/1213: {the pixel elements being TFTs}
- H10K 59/122: Pixel-defining structures or layers, e.g. banks
- H10K: ORGANIC ELECTRIC SOLID-STATE DEVICES

## Abstract

An electroluminescent display device can include a lower substrate divided into an active area and a non-active area, a thin film transistor disposed above the lower substrate, a planarization layer disposed above the thin film transistor, a light emitting diode disposed above the planarization layer, a bank disposed on the planarization layer to partition an emission area, an upper substrate disposed opposite to the lower substrate, a filler filled in a space between the upper substrate and the light emitting diode, a dam structure enclosing the filler in the non-active area, a plurality of alignment holes disposed between the active area and the dam structure, and a plurality of guide pins provided in the upper substrate of the non-active area to be fitted into the plurality of alignment holes. By doing this, the color mixture defect due to the bonding defect can be suppressed or minimized.

## Claims

### Claim 1

An electroluminescent display device, comprising:
a lower substrate divided into an active area and a non-active area;
a thin film transistor disposed above the lower substrate;
a planarization layer disposed above the thin film transistor;
a light emitting diode disposed above the planarization layer, and including an anode, a light emitting unit, and a cathode;
a bank disposed on the planarization layer to partition an emission area;
an upper substrate disposed opposite to the lower substrate;
a filler filled in a space between the upper substrate and the light emitting diode;
a dam structure enclosing the filler in the non-active area;
a plurality of alignment holes disposed between the active area and the dam structure, and provided by removing a portion of the bank; and
a plurality of guide pins provided on the upper substrate of the non-active area to be fitted into the plurality of alignment holes,
wherein the plurality of guide pins are in contact with the filler, and
wherein the plurality of guide pins are disposed within the filler.

### Claim 2 (depends on 1)

The electroluminescent display device according to claim 1, wherein the planarization layer extends to a part of the non-active area,
a side surface of the extending planarization layer is configured to be inclined, and
the bank extends to cover the inclined side surface of the planarization layer of the non-active area so that a side surface of the bank is disposed to be inclined.

### Claim 3 (depends on 2)

The electroluminescent display device according to claim 2, further comprising:
an encapsulation layer disposed on the cathode and the bank,
wherein the filler is filled in a space between the upper substrate and the encapsulation layer, and
wherein the encapsulation layer extends to cover the inclined side surface of the bank of the non-active area so that a side surface of the encapsulation layer is disposed to be inclined.

### Claim 4 (depends on 3)

The electroluminescent display device according to claim 3, wherein the plurality of alignment holes are provided by removing a part of thicknesses of the bank and the planarization layer inside the dam structure.

### Claim 5 (depends on 1)

The electroluminescent display device according to claim 1, wherein one of the plurality of alignment holes is spaced apart from ends of the cathode and the light emitting unit with a predetermined distance therebetween.

### Claim 6 (depends on 1)

The electroluminescent display device according to claim 1, wherein one of the plurality of alignment holes and one of the plurality of guide pins have circular or quadrangular cross-sections and the one alignment hole has a diameter or width larger than that of the one guide pin.

### Claim 7 (depends on 1)

The electroluminescent display device according to claim 1, wherein the plurality of alignment holes are disposed in number to correspond to the plurality of guide pins facing each other.

### Claim 8 (depends on 7)

The electroluminescent display device according to claim 7, wherein one of the plurality of guide pins is disposed inside the dam structure along a periphery of the active area.

### Claim 9 (depends on 1)

The electroluminescent display device according to claim 1, wherein one of the plurality of alignment holes is disposed to be elongated along a periphery of the active area.

### Claim 10 (depends on 9)

The electroluminescent display device according to claim 9, wherein the one alignment hole is disposed over the non-active area having four side surfaces which encloses the periphery of the active area.

### Claim 11 (depends on 1)

The electroluminescent display device according to claim 1, wherein one of the plurality of alignment holes has either (i) a wedged shape having a width which becomes narrower toward a bottom, or (ii) an upper width equal to a lower width.

### Claim 12 (depends on 11)

The electroluminescent display device according to claim 11, wherein one of the plurality of guide pins has an end having a wedged shape corresponding to the wedged shape of the one alignment hole.

### Claim 13 (depends on 1)

The electroluminescent display device according to claim 1, wherein the plurality of alignment holes and the plurality of guide pins are disposed in a plurality of columns and have different widths depending on the columns.

### Claim 14 (depends on 1)

The electroluminescent display device according to claim 1, wherein, depending on respectively positions of the plurality of guide pins, the plurality of guide pins have either (i) different densities being a different number of guide pins disposed per unit area, or (ii) different cross-sections being a different area of the cross-section of the guide pin which is fitted into an alignment hole.

### Claim 15 (depends on 14)

The electroluminescent display device according to claim 14, wherein the plurality of guide pins are disposed to have a density or the cross-sectional area which is reduced from a corner of the active area to a horizontal and/or vertical direction.

### Claim 16 (depends on 14)

The electroluminescent display device according to claim 14, wherein the plurality of guide pins differentiate the density or the cross-sectional area so as to be horizontally and/or vertically symmetrical to a display panel.

### Claim 17 (depends on 14)

The electroluminescent display device according to claim 14, wherein the plurality of alignment holes differentiate the density or the cross-sectional area depending on a placement of a corresponding guide pin.

### Claim 18 (depends on 1)

The electroluminescent display device according to claim 1, wherein the plurality of guide pins include a first guide pin having a circular or quadrangular cross-section, a second guide pin having a cross-shaped cross-section, and a third guide pin having a snowflake shaped cross-section.

### Claim 19 (depends on 1)

The electroluminescent display device according to claim 1, wherein one of the plurality of guide pins is disposed at a corner of a display panel with an “L” shape, a cross-shape, or a snowflake shape.