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US-12622139-B2 - Display panel and display device including the same

US12622139B2US 12622139 B2US12622139 B2US 12622139B2US-12622139-B2

Abstract

Discussed is a display panel including a display area composed of a light-emitting area and a light-transmissive area in which a dark spot defect in the light-transmissive area does not occur. Further, in the display panel, a decrease in transmittance due to light leakage can be prevented, and color mixing between adjacent pixels can be prevented. To this end, a metal layer is disposed at a boundary between the light-emitting area and the light-transmissive area, a metal layer is disposed at a boundary between sub-pixels rendering different colors and adjacent to each other, and a metal layer is disposed at a boundary between two adjacent light-transmissive areas.

Inventors

  • Yongmin Kim
  • Jaeyoung Oh

Assignees

  • LG DISPLAY CO., LTD.

Dates

Publication Date
20260505
Application Date
20240626
Priority Date
20211118

Claims (18)

  1. 1 . A display panel comprising: a plurality of light-transmissive areas through which light is transmitted; and a plurality of light-emitting area disposed between two adjacent light-transmissive areas, wherein a metal layer is disposed at a boundary between a light-transmissive area and a light-emitting area adjacent to each other, wherein the metal layer is disposed on a cathode electrode, wherein each sub-pixel of the light-emitting area includes: a first substrate; a buffer layer disposed on the first substrate; a first insulating layer disposed on the buffer layer; a gate insulating layer disposed on the buffer layer; a passivation layer disposed on the gate insulating layer; an overcoat layer disposed on the passivation layer; an anode electrode disposed on the overcoat layer; and a bank layer and an organic light-emitting layer disposed on the anode electrode, wherein the light-emitting area includes a light-emitting element having an anode electrode, an organic light-emitting layer and the cathode electrode, wherein the cathode electrode extends outwardly of the light-emitting area and on an adjacent light-transmissive area, and wherein the metal layer is disposed on a portion of the cathode electrode and the light-emitting layer at the boundary between the light-transmissive areas and the light-emitting area.
  2. 2 . The display panel of claim 1 , wherein the metal layer is disposed at a boundary between two light-transmissive areas adjacent to each other.
  3. 3 . The display panel of claim 2 , wherein the metal layer is disposed at a boundary between two light-emitting areas adjacent to each other.
  4. 4 . The display panel of claim 1 , wherein the metal layer includes aluminum or an alloy including aluminum.
  5. 5 . The display panel of claim 4 , wherein the alloy includes one selected from a group consisting of an alloy material of aluminum and titanium, an alloy material of aluminum and molybdenum, and an alloy material of aluminum and indium zinc oxide.
  6. 6 . The display panel of claim 1 , wherein the light-emitting area includes a plurality of sub-pixels rendering different colors and a plurality of sub-pixels rendering a same color.
  7. 7 . The display panel of claim 6 , wherein the metal layer is disposed at a boundary between two adjacent sub-pixels rendering different colors and is not disposed at a boundary between two adjacent sub-pixels rendering a same color.
  8. 8 . The display panel of claim 6 , wherein the sub-pixels include a red sub-pixel, a green sub-pixel, a blue sub-pixel and a white sub-pixel, and wherein each of the anode electrode, the organic light-emitting layer and the cathode electrode is made of a transparent material.
  9. 9 . The display panel of claim 1 , wherein the light-emitting area emits light when power is applied thereto, and wherein when the power of the light-emitting area is turned off, natural light transmits through the two adjacent light-transmissive areas so that a look of nature is visible.
  10. 10 . The display panel of claim 1 , further comprising: a foreign material located on the light-emitting area; and a metal oxide layer disposed on the light-emitting area, and in contact with the foreign material.
  11. 11 . A display device comprising: a display panel including: a light-transmissive area through which light is transmitted; and a light-emitting area disposed between two adjacent light-transmissive areas, wherein a metal layer is disposed at a boundary between the light-transmissive area and the light-emitting area adjacent to each other; a data driver configured to apply a data signal to the light-emitting area; a scan driver configured to apply a scan signal to the light-emitting area; and a timing controller configured to control the data driver and the scan driver, wherein the metal layer is disposed on a cathode electrode, wherein each sub-pixel of the light-emitting area includes: a first substrate; a buffer layer disposed on the first substrate; a first insulating layer disposed on the buffer layer; a gate insulating layer disposed on the buffer layer; a passivation layer disposed on the gate insulating layer; an overcoat layer disposed on the passivation layer; an anode electrode disposed on the overcoat layer; and a bank layer and an organic light-emitting layer disposed on the anode electrode, wherein the light-emitting area includes a light-emitting element having an anode electrode, an organic light-emitting layer and the cathode electrode, wherein the cathode electrode extends outwardly of the light-emitting area and on an adjacent light-transmissive area, and wherein the metal layer is disposed on a portion of the cathode electrode and the light-emitting layer at the boundary between the light-transmissive area and the light-emitting area.
  12. 12 . The display device of claim 11 , wherein each sub-pixel further includes: a switching thin film transistor (TFT) for switching a data voltage path from a data line in response to a scan signal input through a gate line; a driving TFT turned on based on a magnitude of data voltage from the switching TFT to control an amount of light emitted from an organic light-emitting diode; a variable storage capacitor connected to a gate electrode of the driving TFT and in parallel with the driving TFT, wherein a capacitance of the variable storage capacitor varies based on a magnitude of voltage applied to the gate electrode of the driving TFT; and a fixed capacitor having a smaller fixed capacitance than the capacitance of the variable storage capacitor, wherein the fixed capacitor is connected in parallel with the variable storage capacitor.
  13. 13 . The display device of claim 12 , wherein the fixed capacitor includes: the gate electrode of the driving TFT; a gate insulating layer of the driving TFT; and a conductive electrode layer overlapping with at least a partial area of the gate electrode of the driving TFT, wherein the gate insulating layer thereof is interposed between the gate electrode and the conductive electrode layer, and wherein the conductive electrode layer is electrically connected to a high-potential or low-potential voltage supply terminal.
  14. 14 . The display device of claim 11 , wherein each sub-pixel further includes: a second insulating layer disposed on the metal layer; a black matrix and a color filter layer disposed on the second insulating layer; and a second substrate disposed on the black matrix and the color filter layer.
  15. 15 . The display device of claim 11 , wherein the anode electrode includes indium tin oxide, molybdenum, or indium zinc oxide, and wherein the cathode electrode includes indium zinc oxide.
  16. 16 . The display device of claim 11 , wherein the anode electrode includes indium tin oxide, indium zinc oxide, indium tin zinc oxide, zinc oxide, or tin oxide.
  17. 17 . The display device of claim 11 , wherein the cathode electrode includes at least one selected from a group consisting of magnesium, calcium, sodium, titanium, indium, yttrium, lithium, aluminum, silver, tin, lead, or an alloy thereof.
  18. 18 . The display device of claim 11 , wherein a foreign material exists on the anode electrode, wherein the organic light-emitting layer is formed on the foreign material, and wherein when the metal layer is deposited on the cathode electrode, the metal layer is converted into a metal oxide layer using an aging process, so that the metal oxide layer is formed between the foreign material and the anode electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION This application is a Continuation of U.S. patent application Ser. No. 17/989,482, filed on Nov. 17, 2022, which claims priority under 35 U.S.C. § 119 (a) to Korean Patent Application No. 10-2021-0159755 filed on Nov. 18, 2021, in the Korean Intellectual Property Office, the entire contents of all these applications being hereby expressly incorporated by reference into the present application. BACKGROUND Field The present disclosure relates to a display panel in which in a large-area display having a display area composed of a light-emitting area and a light-transmissive area, a dark spot defect in the light-transmissive area can be reduced, and decrease in transmittance due to light leakage can be prevented, and color mixing between adjacent pixels can be prevented. The present disclosure further relates to a display device including the display panel. Description of Related Art A flat panel display device (FPD) includes an organic light-emitting diode (OLED) display device which has high luminance and low operating voltage. The OLED display device is a self-luminous type device that emits light by itself. Thus, a contrast ratio thereof is high and the device can realize an ultra-thin display. The device has a response time of several microseconds, so that it is easy to realize a moving image. There is no restriction on viewing angle of an OLED display device. The device is stable even at low temperatures. The device operates at a low voltage. Thus, it is easy to manufacture and design an operation circuit thereof. Each pixel area of the OLED display device includes a plurality of thin-film transistors, such as a switching thin-film transistor, a driving thin-film transistor, and a sensing thin-film transistor. SUMMARY OF THE DISCLOSURE Recently, a transparent display device using an OLED display device has been widely developed. The transparent display device shows a look of nature through a light-transmissive area, and thus displays image information and surrounding environment information together. Each pixel of the transparent display device using the OLED display device includes light-emitting areas to emit light of red, green, and blue colors, respectively, and selectively activates the red, green, and blue light-emitting areas to display various color images. Each of light-emitting layers to emit light of red, green, and blue colors is formed by performing a vacuum thermal evaporation process to selectively deposit a light emitting material using a fine metal mask. However, in a top emission type transparent display device, a cathode electrode of a pixel area can be formed by performing sputtering (SPT) deposition of indium zinc oxide (IZO). Therefore, in the top emission type transparent display device, an amount of a foreign material as produced is 10 times greater than that in a bottom emission type display device, which may result in dark spots on a display screen. Accordingly, in order to address the above limitations, the inventors of the present disclosure have invented a display panel of a large-area display device having a display area composed of a light-emitting area and a light-transmissive area in which a metal layer is disposed at a boundary between the light-emitting area and the light-transmissive area, thereby preventing a short circuit between anode and cathode electrodes in an organic light-emitting area as caused by a foreign material, and reducing dark spot defect in the light-transmissive area. Further, the inventors of the present disclosure have invented a display device in which a metal layer is disposed at a boundary between a light-emitting area and a light-transmissive area of a display area, and a metal layer is disposed at a boundary between sub-pixels rendering different colors and adjacent to each other, and a metal layer is disposed at a boundary between two adjacent light-transmissive areas, thereby preventing or minimizing decrease in transmittance due to light leakage and preventing mixing between colors of adjacent pixels. Purposes according to the present disclosure are not limited to the above-mentioned purpose. Other purposes and advantages according to the present disclosure that are not mentioned can be understood based on following descriptions, and can be more clearly understood according to embodiments according to the present disclosure. Further, it will be easily understood that the purposes and advantages according to the present disclosure can be realized using means shown in the claims and combinations thereof. A display panel according to one embodiment of the present disclosure can be provided. In a display area of the display panel, a light-emitting area can be disposed between two light-transmissive areas. A metal layer or an alloy film can be disposed at a boundary between the light-transmissive area and the light-emitting area. Further, a display device according to one embodiment of the present disclosure