Search

CN-115249734-B - OLED display and method of constructing an OLED display

CN115249734BCN 115249734 BCN115249734 BCN 115249734BCN-115249734-B

Abstract

An Organic Light Emitting Device (OLED) display is provided. The OLED display includes a Thin Film Transistor (TFT) substrate having a plurality of TFTs and a plurality of data lines controlling the plurality of TFTs. The OLED display further includes a conductive shielding layer disposed on the TFT substrate and an OLED layer disposed on the conductive shielding layer. The OLED layer includes a plurality of OLEDs driven by a plurality of TFTs. The OLED layer also includes a touch panel layer disposed over the OLED layer. The conductive shielding layer is configured to reduce noise coupling between the TFT substrate and the touch panel layer.

Inventors

  • Mou Jinde
  • ANDREW KAY

Assignees

  • 夏普株式会社

Dates

Publication Date
20260512
Application Date
20220420
Priority Date
20210428

Claims (20)

  1. 1. A kind of OLED display device, characterized in that it comprises: a TFT substrate, comprising: A plurality of TFTs, and A plurality of data lines connected to and controlling the plurality of TFTs; A conductive shielding layer disposed on the TFT substrate; An OLED layer disposed over the conductive shielding layer, the OLED layer including a plurality of OLEDs driven by the plurality of TFTs, each OLED of the plurality of OLEDs including an anode connected to the TFTs, a light emitting layer formed on an upper layer than the anode, and a cathode formed on an upper layer than the light emitting layer, and A touch panel layer disposed over the OLED layer, The conductive shielding layer is configured to reduce noise coupling between the TFT substrate and the touch panel layer, and the conductive shielding layer is located between the data line and the cathode and overlaps the data line.
  2. 2. The OLED display of claim 1, wherein the conductive shield layer is held at a DC bias voltage.
  3. 3. The OLED display of claim 1, wherein the conductive shield layer is capacitively coupled to at least one of the plurality of data lines.
  4. 4. The OLED display of claim 1, wherein the plurality of OLEDs includes at least one cathode that carries a return current from the plurality of OLEDs.
  5. 5. The OLED display of claim 4, wherein the at least one cathode includes a single conductive layer coupling a plurality of OLEDs of the plurality of OLEDs.
  6. 6. The OLED display of claim 4, wherein the at least one cathode is capacitively coupled to the conductive shield layer.
  7. 7. The OLED display of claim 4, wherein the organic light emitting diode display comprises, The at least one cathode having a first resistivity, and The conductive shield layer has a second resistivity that is lower than the first resistivity.
  8. 8. The OLED display of claim 4, wherein the at least one cathode and the conductive shield layer are maintained at a first dc voltage.
  9. 9. The OLED display of claim 4, wherein the organic light emitting diode display comprises, The OLED layer further includes an encapsulation layer disposed over the at least one cathode, and The touch panel layer is deposited over the encapsulation layer.
  10. 10. The OLED display of claim 9, wherein the encapsulation layer comprises a thin film encapsulation layer.
  11. 11. The OLED display of claim 4, wherein the organic light emitting diode display comprises, The touch panel layer includes at least one touch panel electrode, and The at least one touch panel electrode is capacitively coupled to the at least one cathode.
  12. 12. The OLED display of claim 11, wherein the at least one touch panel electrode forms a pattern within the touch panel layer that spans two dimensions.
  13. 13. The OLED display of claim 1, wherein the conductive shield layer includes a plurality of traces extending parallel to the TFT substrate.
  14. 14. The OLED display of claim 13, wherein each trace of the plurality of traces is positioned vertically above and in aligned overlapping relation with at least a portion of at least one of the plurality of data lines.
  15. 15. A method of constructing an OLED display, the method comprising: forming a conductive shielding layer on a TFT substrate, the TFT substrate comprising: A plurality of TFTs, and A plurality of data lines connected to and controlling the plurality of TFTs; Forming an OLED layer over the conductive shield layer, the OLED layer including a plurality of OLEDs driven by the plurality of TFTs, each OLED of the plurality of OLEDs including an anode connected to the TFTs, a light emitting layer formed on an upper layer than the anode, and a cathode formed on an upper layer than the light emitting layer, and A touch panel layer is formed over the OLED layer, the conductive shield layer is configured to reduce noise coupling between the TFT substrate and the touch panel layer, and the conductive shield layer is located between the data line and the cathode and overlaps the data line.
  16. 16. The method of claim 15, wherein the step of determining the position of the probe is performed, Forming the OLED layer includes forming at least one cathode to the plurality of OLEDs to carry return current from the plurality of OLEDs, and The conductive shielding layer is capacitively coupled to the at least one cathode.
  17. 17. The method of claim 16, further comprising connecting the conductive shielding layer to a DC bias voltage source.
  18. 18. The method of claim 17, further comprising connecting the at least one cathode to the DC bias voltage source.
  19. 19. The method of claim 15, wherein the conductive shield layer is capacitively coupled to the plurality of data lines.
  20. 20. The method of claim 19, wherein the step of determining the position of the probe comprises, Forming the conductive shielding layer includes forming a plurality of traces extending parallel to the TFT substrate, and Each of the plurality of traces is positioned vertically over and in aligned overlapping relation with at least a portion of at least one of the plurality of data lines.

Description

OLED display and method of constructing an OLED display Technical Field The present disclosure relates generally to touch sensitive displays and, more particularly, to a touch sensitive display with a shield to reduce noise coupling from display-related devices to a touch sensor. Background In conventional touch-sensitive displays (e.g., touch screens for smartphones, tablets, etc.), thousands of pixels, each of which may include multiple sub-pixels (e.g., red, green, and blue sub-pixels), may be distributed across two horizontal dimensions of the display. In many examples, each subpixel may include an Organic Light Emitting Device (OLED), although other types of light sources may be used in other implementations. In many cases, each OLED may be driven by a drive transistor, possibly in combination with other transistors. These transistors may be located in the substrate below the OLEDs and may be controlled by a number of data and/or control lines indicating the amount of light each OLED is to emit and the time of emission. These data and control lines are typically routed within the substrate on which the transistors are located. In some examples, the transistor may include a Thin Film Transistor (TFT). To achieve the touch sensitivity function of the display, multiple touch sensors may be located in the layers of the display above the OLED. The sensors may be configured in a grid or other two-dimensional pattern such that a particular location of a user's touch on the display may be interpreted as a user input to a device using the display. In order to thin the display (e.g., for use in a user device having a convenient form factor, such as a handheld device), the layers of the display mentioned above may be positioned close enough to each other that components of nearby layers may exhibit significant capacitive coupling therebetween. With the current product trend to create increasingly thinner devices and associated displays, this increased capacitive coupling may lead to electrical noise coupling between the layers and thus may lead to failure in the electrical operation of the device. Disclosure of Invention The present disclosure relates to touch sensitive display devices (e.g., OLED displays) that employ shielding layers therein. According to one aspect of the present disclosure, an OLED display may include a Thin Film Transistor (TFT) including a plurality of TFTs and a plurality of data lines controlling the plurality of TFTs. The OLED may further include a conductive shielding layer disposed on the TFT substrate, an OLED layer disposed on the conductive shielding layer, and a touch panel layer disposed on the OLED layer. The OLED layer may include a plurality of OLEDs driven by a plurality of TFTs. The conductive shielding layer may be configured to reduce noise coupling between the TFT substrate and the touch panel layer. In an embodiment of the first aspect, the conductive shielding layer may be maintained at a Direct Current (DC) bias voltage. In another embodiment of the first aspect, the conductive shielding layer may be capacitively coupled with at least one of the plurality of data lines. In yet another embodiment of the first aspect, the plurality of OLEDs may include at least one cathode that carries a return current from the plurality of OLEDs. In this embodiment, the at least one cathode may include a single conductive layer coupling a plurality of OLEDs of the plurality of OLEDs. Further, in some examples, at least one cathode may be capacitively coupled to the conductive shielding layer. Also, in such embodiments, the at least one cathode may have a first resistivity and the conductive shielding layer may have a second resistivity that is lower than the first resistivity. Additionally, in this embodiment, the at least one cathode and the conductive shielding layer may be maintained at a first DC voltage. In yet another embodiment of the first aspect, the OLED layer may further include an encapsulation layer disposed over the at least one cathode, and the touch panel layer may be deposited over the encapsulation layer. In some examples, the encapsulation layer may include a Thin Film Encapsulation (TFE) layer. In another embodiment of the first aspect, the touch panel layer may include at least one touch panel electrode, and the at least one touch panel electrode may be capacitively coupled with the at least one cathode. In such an embodiment, at least one touch panel electrode may form a pattern within the touch panel layer that spans two dimensions. In another embodiment of the first aspect, the conductive shielding layer may include a plurality of traces extending parallel to the TFT substrate. In such an embodiment, each of the plurality of traces is positioned vertically over and aligned with at least a portion of at least one of the plurality of data lines. According to a second aspect of the present disclosure, a method of constructing an OLED display may include forming a con