OLED display and method of fabricating an OLED display

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 to control the plurality of TFTs. The OLED display also includes a conductive shield layer disposed on the TFT substrate and an OLED layer disposed on the conductive shield layer. The OLED layer includes a plurality of OLEDs driven by the plurality of TFTs. The OLED layer also includes a touch panel layer configured over the OLED layer. The conductive shield layer is configured to reduce noise coupling between the TFT substrate and the touch panel layer.

Description

Technical Field

[0001] This disclosure generally relates to touch-sensitive displays, and more particularly to a touch-sensitive display with a shielding layer to reduce noise coupling from display-related devices to touch sensors. Background Technology

[0002] In traditional touch-sensitive displays (e.g., touchscreens for smartphones, tablets, etc.), thousands of pixels, each of which may include multiple subpixels (e.g., red, green, and blue subpixels), can 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 driving transistor, possibly combined with other transistors. These transistors may be located in a substrate beneath the OLED and may be controlled by numerous data and / or control lines indicating the amount of light to be emitted by each OLED and the timing of that emission. These data and control lines are typically wired within the substrate where the transistors reside. In some examples, the transistors may include thin-film transistors (TFTs).

[0003] To enable touch sensitivity in a display, multiple touch sensors can be located in a layer of the display above the OLED. The sensors can be configured as a grid or other two-dimensional pattern, allowing a specific location touched by a user on the display to be interpreted as user input from a device using the display.

[0004] To make displays thinner (e.g., in user devices with convenient form factors such as handheld devices), the aforementioned display layers can be positioned close enough to each other that components in nearby layers can exhibit significant capacitive coupling between them. With current product trends towards creating increasingly thinner devices and associated displays, this increased capacitive coupling can lead to electrical noise coupled between these layers, potentially causing malfunctions in the device's electrical operation. Summary of the Invention

[0005] This disclosure relates to touch-sensitive display devices (e.g., OLED displays) that employ a shielding layer therein.

[0006] According to one aspect of this disclosure, an OLED display may include thin-film transistors (TFTs) comprising 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 a 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 the plurality of TFTs. The conductive shielding layer may be configured to reduce noise coupling between the TFT substrate and the touch panel layer.

[0007] 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 to at least one of the plurality of data lines.

[0008] In yet another embodiment of the first aspect, the plurality of OLEDs may include at least one cathode carrying return current from the plurality of OLEDs. In this embodiment, the at least one cathode may include a single conductive layer coupling the plurality of OLEDs. Further, in some examples, the at least one cathode may be capacitively coupled to a conductive shielding layer. Moreover, in such an embodiment, the at least one cathode may have a first resistivity, and the conductive shielding layer may have a second resistivity 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.

[0009] 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.

[0010] 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 coupled to the at least one cathode capacitor. In this embodiment, the at least one touch panel electrode may be patterned across two dimensions within the touch panel layer.

[0011] In another embodiment of the first aspect, the conductive shielding layer may include a plurality of traces extending parallel to the TFT substrate. In this embodiment, each of the plurality of traces is vertically positioned above and aligned with at least a portion of at least one of the plurality of data lines.

[0012] According to a second aspect of this disclosure, a method of constructing an OLED display may include forming a conductive shielding layer on a thin-film transistor (TFT) substrate. The TFT substrate may include a plurality of TFTs and a plurality of data lines controlling the plurality of TFTs. The method may further include forming an OLED layer over the conductive shielding layer and forming a touch panel layer disposed over the OLED layer. The OLED may include a plurality of OLEDs driven by the plurality of TFTs. The conductive shielding layer may be configured to reduce noise coupling between the TFT substrate and the touch panel layer.

[0013] In one embodiment of the second aspect, forming the OLED layer may include forming at least one cathode to the plurality of OLEDs to carry return current from the plurality of OLEDs; and the conductive shielding layer being capacitively coupled to the at least one cathode. Further, in this embodiment, the method may further include connecting the conductive shielding layer to a direct current (DC) bias voltage source. The method may further include connecting the at least one cathode to the DC bias voltage source.

[0014] In another embodiment of the second aspect, the conductive shielding layer may be capacitively coupled to the plurality of data lines. In this embodiment, 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 vertically positioned over and aligned with at least a portion of at least one of the plurality of data lines. Attached Figure Description

[0015] The various aspects of the embodiments are best understood from the following detailed description, taken in conjunction with the accompanying drawings. The different features are not drawn to scale. For clarity, the dimensions of the different features may be arbitrarily increased or decreased.

[0016] Figure 1 This is a schematic model of a part of existing OLED display technology.

[0017] Figure 2 This is a cross-sectional view of a portion of an OLED display including a conductive shielding layer according to an exemplary embodiment of the present disclosure.

[0018] Figure 3 This is a schematic model of a portion of an OLED display including a conductive shielding layer according to an exemplary embodiment of the present disclosure.

[0019] Figure 4 This is a schematic model of a portion of an OLED display including a conductive shielding layer according to another exemplary embodiment of this disclosure.

[0020] Figure 5This is a flowchart of a method for constructing an OLED display including a conductive shielding layer according to an exemplary embodiment of the present disclosure. Detailed Implementation

[0021] The following description contains specific information relating to embodiments of the present disclosure. The accompanying drawings and their descriptions are for illustrative purposes only. However, the present disclosure is not limited to these embodiments. Other variations and implementations of the present disclosure will be apparent to those skilled in the art. Unless otherwise indicated, the same or corresponding elements in the drawings may be represented by the same or corresponding reference numerals. Moreover, the drawings and illustrations are generally not drawn to scale and are not intended to correspond to actual relative dimensions.

[0022] For the purposes of consistency and ease of understanding, similar features may be identified by the reference numerals in the example figures (although not shown in some examples). However, features in different embodiments may differ in other respects and should therefore not be limited to those shown in the figures.

[0023] The phrases “in one embodiment” or “in some embodiments” can refer to one or more of the same or different embodiments, respectively. The term “coupled” is defined as a connection, whether directly or indirectly through intervening components, and is not necessarily limited to a physical connection. The term “comprising” means “including but not limited to”, specifically indicating open inclusion or subordination in combinations, groups, series, and equivalents so described.

[0024] Furthermore, any two or more of the following paragraphs, (sub)-bullet marks, points, actions, behaviors, terms, alternatives, examples, or claims described in the following disclosure are logically, reasonably, and appropriately combined to form a particular method. Any sentence, paragraph, (sub)-bullet mark, point, action, behavior, term, or claim described in the following disclosure is implemented independently and separately to form a particular method. For example, dependencies such as “according to,” “more specifically,” “preferably,” “in one embodiment,” “in one implementation,” “in an alternative,” etc., in the following disclosure are merely possible examples that do not limit the particular method.

[0025] For purposes of explanation and non-restriction, specific details such as functional entities, technologies, protocols, and standards are described to provide an understanding of the technologies being described. In other instances, detailed descriptions of well-known methods, technologies, systems, and architectures are omitted to avoid unnecessary obfuscation with detail.

[0026] Furthermore, while certain directional references (e.g., top, bottom, up, down, height, width, etc.) are used in the following description and the appended claims, such references are intended to provide guidance on the positioning and size of the different elements relative to each other and are not intended to limit the orientations of the different embodiments to those explicitly discussed herein.

[0027] The various embodiments of the OLED display described below can reduce or suppress the coupling of electrical noise between two or more portions of the display. In at least some embodiments, a conductive shielding layer may be incorporated within the display to electrically isolate the display's touch sensors from potential sources of electrical noise within the display.

[0028] Figure 1 This is a schematic model of an OLED display 100 that is part of the prior art. For example... Figure 1 As shown, an OLED display 100 may include multiple transistors (e.g., TFTs) that drive light-emitting devices (e.g., OLEDs) to emit light of a desired intensity over a specific time period. The OLED display 100 may include multiple OLEDs configured in a grid or array of multiple rows and columns to generate an image for viewing. More specifically, the OLEDs may be configured as pixel arrays, where each pixel may include multiple subpixels (e.g., each subpixel is used to emit red, green, or blue light emitted by the corresponding OLED). However, in Figure 1 A single OLED is depicted to simplify the discussion of the OLED display 100.

[0029] The amount or intensity of light emitted by the OLED can be controlled by the amount of current flowing through the OLED from the first power supply voltage VDD via the driving transistor TD. Furthermore, the amount of this current can be determined by a specific voltage potential across the gate and second terminals of the driving transistor TD. Figure 1 In this process, the voltage can be stored by a storage capacitor CS, which can be charged by a switching transistor TS. The switching transistor TS temporarily connects one plate of the storage capacitor CS to a data line 106, which provides a voltage level related to the desired illuminance of the OLED for a specific period of time. The switching transistor TS can then be controlled (e.g., turned on and off) by a scan signal 108. Although Figure 1 The schematic model shows a single switching transistor TS in addition to the driving transistor TD, but other examples may include additional switching transistors and / or other components that receive data and control signals to supply current to the OLED to emit light.

[0030] In some examples, each column of OLEDs may be driven by the same data line 106 for that column, and each row of OLEDs may be controlled by the same scan signal 108 for that row. Therefore, each scan signal 108 can simultaneously transmit voltage from all data lines 106 to the corresponding OLED in the row served by that scan signal 108. As each data line 106 serves the corresponding OLED in each row, the data line 106 potentially changes the voltage in each time period allocated to each row of OLEDs, and thus can represent a significant potential source of electrical noise that could adversely affect other parts of the OLED display 100, as described below. Additionally, other signals that periodically change voltage (e.g., scan signal 108) can also be sources of electrical noise.

[0031] In at least some embodiments, such as Figure 1 As shown, multiple transistors TD and TS, data lines 106, scan lines 108, etc., can form a TFT layer or substrate within the OLED display 100. Located above the TFT substrate is an OLED layer, which includes OLEDs driven by corresponding driving transistors TD. For example... Figure 1 As shown, the anode of each OLED can be connected to the terminal of a corresponding driving transistor TD, and the cathode of each OLED can be electrically connected to a second power supply voltage VSS having a voltage lower than the first power supply voltage VDD. Further, in some embodiments, since the cathode of each OLED can be connected to the same second power supply voltage VSS, the cathodes of multiple OLEDs can be coupled to the second power supply voltage VSS through a single cathode 104. In some examples, a single cathode 104 can be used for all or substantially all OLEDs of the OLED display 100 and is formed as a continuous sheet or layer of conductive material.

[0032] exist Figure 1 The diagram also shows that above the OLED layer may be a touch panel layer (e.g., in an "external" configuration), which may include at least one touch electrode 102 coupled to a charge integrator 103. In some examples, the charge integrator 103 may be configured to detect changes in capacitance associated with the touch electrode 102, which may indicate the proximity of a user's finger, stylus, etc., to the touch electrode 102. Figure 1 In the example, charge integrator 103 may include an operational amplifier with capacitors and switches (e.g., transistors). However, another type of charge integrator 103, or another type of circuit not discussed herein, may be configured to use touch electrodes 102 to detect the proximity of a user or stylus.

[0033] To achieve relatively fine resolution in detecting proximity locations across the entire OLED display 100, a plurality of touch electrodes 102 may be distributed across the OLED display 100. For example, the plurality of touch electrodes 102 may be configured as conductive lines extending in two directions within the OLED display 100, such as in a rectangular or diagonal (e.g., diamond) pattern that substantially extends across the entire OLED display 100.

[0034] like Figure 1 As shown, one or more touch electrodes 102 of the touch panel layer, one or more OLED cathodes 104 of the OLED layer, and data lines 106 of the TFT substrate can be formed as closely spaced parallel conductors operating as parasitic capacitances. Furthermore, in some examples where the OLED cathodes 104 are typically configured as continuous or nearly continuous conductive sheets, capacitive coupling between the data lines 106 and one or more OLED cathodes 104, and between one or more OLED cathodes 104 and one or more touch electrodes 102, can be significant. Figure 1 In this context, these capacitors are described as the first parasitic capacitance C between the data line 106 and one or more OLED cathodes 104. P1 and a second parasitic capacitance C between one or more OLED cathodes 104 and one or more touch electrodes 102 P2 .

[0035] like Figure 1 As illustrated in the schematic model, since each of the one or more touch electrodes 102, one or more OLED cathodes 104, and data lines 106 is a conductor, each such conductor may have some small but measurable resistance (e.g., less than 1 ohm) along its length within a layer of its corresponding OLED display 100. This resistance is related to the parasitic capacitance C. P1 and C P2 This combination can potentially induce electrical noise in one or more conductors. More specifically, in some examples, voltage variations in the data line 106 of the TFT substrate can cause a first parasitic capacitance C. P1 The voltage change across the terminals alters the energy stored in the capacitor via the first parasitic capacitance C. P1 The amount of charge on two capacitively coupled conductors (e.g., data line 106 and OLED cathode 104). To facilitate this change in charge at the OLED cathode 104, a current may temporarily flow in the OLED cathode 104. This current, due to the small resistance of the OLED cathode 104, can cause temporary voltage variations (e.g., electrical noise) from a second power supply VSS at one or more points along the OLED cathode 104.

[0036] In addition, such as in Figure 1As can be seen from the schematic model of the OLED display 100, voltage changes in the OLED cathode 104 may lead to a second parasitic capacitance C. P2 The voltage change can, in turn, alter the voltage stored in the second parasitic capacitance C. P2 The amount of charge on two capacitively coupled conductors (e.g., OLED cathode 104 and touch electrode 102). To facilitate this charge change at touch electrode 102, current may temporarily flow in touch electrode 102. This current, flowing through the small resistance of touch electrode 102, can cause a temporary voltage change at touch electrode 102, thereby generating electrical noise. This noise may adversely affect the proximity detection function of charge integrator 103 or another proximity detection circuit that may be used in conjunction with touch electrode 102. For example, this coupling noise may produce false positive or false negative proximity events.

[0037] Figure 2 This is a cross-sectional view of a portion of an OLED display 200 including a conductive shielding layer 230 according to an exemplary embodiment of this disclosure. Although Figure 2 A view of a specific portion of one embodiment of the OLED display 200 is provided, but other embodiments may appear somewhat different within the scope of the claims set forth below. Furthermore, while the various layers of the OLED display 200 are discussed below, other layers or sublayers may be incorporated within the OLED display 200, such as various insulating or dielectric layers or sublayers, but for the sake of simplicity, these components are not described further here.

[0038] like Figure 2 As shown, the OLED display 200 may have a TFT substrate 201 that may include a plurality of TFTs 204. The TFT substrate 201 may also include a base substrate 202 (e.g., made of glass or other structurally stable material), on which a plurality of thin film layers may be deposited to form a plurality of TFTs 204. In some embodiments, the TFT substrate 201 may also include a plurality of data lines 206 (e.g., signal lines for indicating a desired OLED brightness level). Figure 2 In the example, a data line 206 is shown at a connection point with multiple TFTs 204.

[0039] A conductive shielding layer 230 may be located or disposed above the TFT substrate 201. In this particular example, the conductive shielding layer 230 may include multiple conductive traces 232 or lines located above and (generally) aligned with the data lines 206, thereby potentially forming a grid. In other embodiments, the conductive shielding layer 230 may be more continuous, thereby covering a larger area of ​​the TFT substrate 201. Furthermore, in some embodiments, the conductive traces 232 may be connected to a specific direct current (DC) bias voltage.

[0040] The layer above the conductive shielding layer 230 may be an OLED layer 210 comprising a plurality of OLEDs 211. In one embodiment, Figure 1 Each OLED 211 shown may be a sub-pixel associated with a corresponding color (e.g., red, green, or blue) of a pixel of the OLED display 200. Each OLED 211 may include an anode 212, which is coupled to a driving TFT 204 (e.g., used as a conductive shielding layer 230) via a connection. Figure 1 The terminals of the driving transistor (TD). Each OLED 211 may also include an emitting layer 214 that emits the desired heat-generating light from the OLED 211. Furthermore, the OLED 211 may include a cathode 216, which is used in conjunction with the anode 212 to allow current to pass through the emitting layer 214 under the control of the driving TFT 204. Figure 2 As shown, although each OLED 211 has a corresponding individual anode 212, all or some subsets of the OLEDs 211 may share a single cathode 216. Furthermore, in some embodiments, as part of the OLED layer 210, the OLED 211 may be covered by an encapsulation layer such as a thin-film encapsulation (TFE) layer 218 to protect the OLED 211 from water and other environmental influences.

[0041] OLED 200 may also include a touch panel layer 220, which may include a plurality of touch sensor electrodes 222 disposed on top of OLED layer 210 (e.g., each as a...). Figure 1 (touch electrode 102). Although in Figure 2 The image depicts a single-layer touch sensor electrode 222, but in other examples, two or more such layers may be used. In some implementations, the touch sensor electrode 222 may be coupled to one or more touch sensing circuits (e.g., Figure 1 (charge integrator 103). In some examples, an additional protective layer (e.g., in...) Figure 2 A glass (not shown) may be disposed on top of the touch panel layer 220. As described in more detail below, the conductive shielding layer 230 can reduce the amount of electrical noise coupled from the TFT substrate 201 to the touch panel layer 220.

[0042] Figure 3 According to exemplary embodiments of this disclosure, a conductive shielding layer is included (e.g., as...). Figure 2 A schematic model of a portion of an OLED display 300 (conductive shielding layer 230). Other components of the OLED display 300 are similar. Figure 1 The corresponding components of the OLED display 100. Figure 3In the middle, located between the data line 106 and the OLED cathode 104 is a conductive shield 302 (e.g., as a...). Figure 2 The conductive trace 232). In some embodiments, the conductive shield 302 may be aligned with and (directly) above the data line 106. Further, a single conductive shield 302 may be located above each of the multiple data lines 106 of the OLED display 300, or each individual conductive shield 302 may be sized and positioned above multiple data lines 106. In other examples, the conductive shield 302 may represent a single conductive sheet opposite one or more traces to substantially cover all data lines 106 of the OLED display 300. Further, in some embodiments, the conductive shield 302 may also be positioned over other control signals (e.g., scan signals, transmit signals, etc.) that drive one or more TFTs, such as switching transistors TS. In each case, each conductive shield 302 may be connected to a DC bias voltage V. BIAS (For example, to reduce the amount of voltage variation that may occur along the conductive shield 302).

[0043] Therefore, the parasitic capacitance C replaces the coupling data line 106 and the OLED cathode 104. P1 ,like Figure 1 As shown, the conductive shield 302 of the OLED display 300 can be controlled by the parasitic capacitance C. P3 Capacitive coupling is applied to data line 106. Furthermore, conductive shield 302 can also be coupled via parasitic capacitance C. P4 Capacitive coupling is achieved to the OLED cathode 104. As described above, this capacitive coupling can occur from the data line 106, the conductive shield 302, and the OLED cathode 104, which are substantially closely spaced conductive plates. Furthermore, the conductive shield 302 may have some small but measurable resistance (e.g., less than 1 ohm) along its length, similar to that of the data line 106 and the touch electrode 102, as referenced above. Figure 1 As stated above.

[0044] according to Figure 3 The schematic model shows that the conductive shield 302 can be used to reduce electrical noise coupling between the data line 106 and the OLED cathode 104, thereby reducing the amount of electrical noise injected into the touch electrode 102. More specifically, changes in the voltage of the data line 106 (e.g., when the data voltage changes from one row of OLEDs to the corresponding data voltage of the next row of OLEDs) may cause parasitic capacitance C. P3 Changes in charge on both sides (e.g., at data line 106 and conductive shield 302). This change in charge may cause current to flow in conductive shield 302, and the voltage at conductive shield 302 will also change due to the small resistance of the current flowing through conductive shield 302.

[0045] Through parasitic capacitance C P4 Noise coupling effects may also occur between the conductive shield 302 and the OLED cathode 104, where voltage changes at the conductive shield 302 may cause voltage changes representing electrical noise in the OLED cathode 104. However, by introducing an additional conductive layer in the form of the conductive shield 302, this embodiment can reduce the overall noise coupling between the data line 106 and the OLED cathode 104 in the OLED display 300 compared to the OLED display 100. For example, the overall positioning and configuration of the conductive shield 302 can lead to parasitic capacitance C. P4 Less than the parasitic capacitance C P3 This results in less overall electrical noise transmitted to the OLED cathode 104.

[0046] Furthermore, given that the conductive shield 302 may have fewer design constraints compared to the data line 106 or the OLED cathode 104, the conductive shield 302 can be configured or adjusted to further reduce the amount of noise coupled from the data line 106 to the OLED cathode 104. For example, the conductive shield 302 can be formed such that its resistivity (e.g., in ohmmeters) is less than that of the OLED cathode 104. In some embodiments, this resistivity difference can cause the voltage of the conductive shield 302 of the OLED display 300 relative to the voltage applied to the data line 106. Figure 1 The voltage variation on the OLED cathode 104 of the OLED display 100 is smaller, resulting in a smaller current induced in the OLED cathode 104 of the OLED display 300.

[0047] Furthermore, in some embodiments, a bias voltage V for the conductive shield 302 can be applied. BIAS The choice of which is to reduce the amount of current induced in the OLED cathode 104. Figure 4 This is a schematic model of a portion of an OLED display 400 including a conductive shield 302, according to another exemplary embodiment of this disclosure. In the OLED display 400, the conductive shield 302 is connected to a voltage source substantially the same as that of the OLED cathode 104 (e.g., a second power supply voltage V). SS Therefore, in this example, localized voltage variations on the conductive shield 302 can lead to parasitic capacitance C. P4 A relatively small voltage change allows for connection to the conductive shield 302 at a voltage different from V. SS Compared to other configurations of other DC voltage levels, this produces relatively small current and associated voltage variations in the OLED cathode 104.

[0048] Figure 5 The construction according to the exemplary embodiments of this disclosure includes a conductive shielding layer (e.g., Figure 2The flowchart of method 500 for constructing an OLED display (e.g., OLED display 200) with a conductive shielding layer 230 is provided. As described below, method 500 assumes that the individual layers of the OLED display are formed from bottom to top, since these layers are depicted in OLED display 200. Other orders for creating and combining different layers can be implemented in other examples.

[0049] In method 500, during operation 502, the TFT substrate (e.g., Figure 2 A conductive shielding layer is formed on the TFT substrate 201. The TFT substrate may include multiple TFTs (e.g., Figure 2 TFT 204) and multiple data lines controlling the TFT (e.g., Figure 2 Data line 206). Furthermore, in some embodiments, it can be achieved by using a mechanically stable substrate (e.g., Figure 2 Various thin film layers are deposited on the substrate 202 to (e.g., Figure 2 A TFT substrate is formed from substrate 202. As described above, the conductive shielding layer may include a single conductive sheet extending parallel to the TFT substrate. In other examples, the conductive shielding layer may include multiple conductive traces extending parallel to the TFT substrate (e.g., Figure 2 The conductive traces 232 can be formed into a network or grid on the TFT substrate. Further, the conductive traces can be vertically disposed on at least some data lines and / or other control signals coupled to the TFTs of the TFT substrate, and aligned parallel to the at least some data lines and / or other control signals. As a result, a conductive shielding layer can be capacitively coupled to at least some data lines and / or other control signals. Additionally, the conductive shielding layer can be connected to a DC bias voltage source.

[0050] Similarly, in method 500, during operation 504, an OLED layer can be formed on top of the conductive shielding layer (e.g., Figure 2 OLED layer 210). The OLED layer may include multiple OLEDs driven by multiple TFTs of a TFT substrate (e.g., OLEDs). Figure 2 (OLED211). For example Figure 2 As shown, each OLED can be composed of an anode (e.g., connected to the corresponding driving TFT) used as an anode. Figure 2 The anode 212) layer and the emitter layer (e.g., Figure 2 An emitter layer 214 is formed. Each anode can supply current to the associated OLED from its corresponding driving TFT. Furthermore, a single cathode (e.g., cathode 216) or multiple cathodes may be formed on most or a portion of the aforementioned layers of the OLED to transfer return current from the OLED to the power supply voltage (e.g., power supply voltage V). SSIn some embodiments, the DC bias voltage of the conductive shielding layer can be the same power supply voltage coupled to one or more OLED cathodes. In some embodiments, an additional encapsulation layer (e.g., Figure 2 The TFE layer 218 can protect the underlying OLED and provide a plane on which additional structures can be formed.

[0051] In operation 506 of method 500, a touch panel layer can be formed on top of the OLED layer (e.g., Figure 2 The touch panel layer 220). In various embodiments, as described above, the conductive shielding layer can be configured to reduce electrical noise coupling between the TFT substrate and the touch panel layer. In some embodiments, the touch panel layer may include one or more layers of touch sensor electrodes (e.g., Figure 2 (touch sensor electrodes 222). Furthermore, in some embodiments, the touch sensor electrodes may be formed into a rectangular or diamond-shaped grid pattern to facilitate proximity detection of fingers, styluses, etc. In some examples, other layers, such as a glass layer or other protective layers, may be formed on top of the touch panel layer.

[0052] Embodiments of the present invention can be applied to a variety of display devices to allow such devices to be advantageously thin (e.g., reducing the amount of device space dedicated to the display) while reducing or substantially eliminating coupling of electrical noise from the individual display elements to the touch electrodes responsible for providing touchscreen functionality. Examples of such touch-sensitive devices include mobile phones, personal digital assistants (PDAs), tablet computers, and laptop computers, as well as similar devices requiring thin, touch-sensitive, high-resolution displays.

[0053] From the foregoing discussion, it is evident that various techniques can be employed to implement the concepts of this disclosure without departing from its scope. Furthermore, while the concepts have been described with specific reference to certain embodiments, those skilled in the art will recognize that changes in form and detail can be made without departing from the scope of those concepts. Thus, this disclosure is to be considered illustrative rather than restrictive in all respects. It should also be understood that while this disclosure is not limited to the specific embodiments described above, many rearrangements, modifications, and substitutions are possible without departing from the scope of this disclosure.

Claims

1. An OLED display, characterized in that, It includes: TFT substrate, comprising: Multiple TFTs; and Multiple data lines connect to and control the multiple TFTs; A conductive shielding layer is disposed on the TFT substrate; An OLED layer disposed above the conductive shielding layer, the OLED layer comprising a plurality of OLEDs driven by the plurality of TFTs, each of the plurality of OLEDs comprising: an anode connected to the TFTs, a light-emitting layer formed above the anode, and a cathode formed above the light-emitting layer; and A touch panel layer is disposed on top of 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 with the data line.

2. The OLED display according to claim 1, characterized in that, The conductive shielding layer is maintained at a DC bias voltage.

3. The OLED display according to claim 1, characterized in that, The conductive shielding layer is capacitively coupled to at least one of the plurality of data lines.

4. The OLED display according to claim 1, characterized in that, The plurality of OLEDs includes at least one cathode that carries the return current from the plurality of OLEDs.

5. The OLED display according to claim 4, characterized in that, The at least one cathode includes a single conductive layer coupled to multiple OLEDs among the plurality of OLEDs.

6. The OLED display according to claim 4, characterized in that, The at least one cathode is capacitively coupled to the conductive shielding layer.

7. The OLED display according to claim 4, characterized in that, The at least one cathode has a first resistivity; and The conductive shielding layer has a second resistivity that is lower than the first resistivity.

8. The OLED display according to claim 4, characterized in that, The at least one cathode and the conductive shielding layer are maintained at a first DC voltage.

9. The OLED display according to claim 4, characterized in that, The OLED layer further includes an encapsulation layer disposed on the at least one cathode; and The touch panel layer is deposited on the encapsulation layer.

10. The OLED display according to claim 9, characterized in that, The encapsulation layer includes a thin-film encapsulation layer.

11. The OLED display according to claim 4, characterized in that, The touch panel layer includes at least one touch panel electrode; and The at least one touch panel electrode is coupled to the at least one cathode capacitor.

12. The OLED display according to claim 11, characterized in that, The at least one touch panel electrode forms a pattern spanning two dimensions within the touch panel layer.

13. The OLED display according to claim 1, characterized in that, The conductive shielding layer includes multiple traces extending parallel to the TFT substrate.

14. The OLED display according to claim 13, characterized in that, Each of the plurality of traces is vertically positioned above at least a portion of at least one of the plurality of data lines and overlaps in alignment with at least a portion of at least one of the plurality of data lines.

15. A method for constructing an OLED display, characterized in that, The method includes: A conductive shielding layer is formed on a TFT substrate, the TFT substrate comprising: Multiple TFTs; and Multiple data lines connect to and control the multiple TFTs; An OLED layer is formed on the conductive shielding layer. The OLED layer includes multiple OLEDs driven by the plurality of TFTs. Each of the plurality of OLEDs includes: an anode connected to the TFTs, a light-emitting layer formed above the anode, and a cathode formed above the light-emitting layer. A touch panel layer is formed on top of 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 with the data line.

16. The method according to claim 15, characterized in that, 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. The method according to claim 16, characterized in that, The method further includes connecting the conductive shielding layer to a DC bias voltage source.

18. The method according to claim 17, characterized in that, It further includes connecting the at least one cathode to the DC bias voltage source.

19. The method according to claim 15, characterized in that, The conductive shielding layer is capacitively coupled to the multiple data lines.

20. The method according to claim 19, characterized in that, Forming the conductive shielding layer includes forming multiple traces extending parallel to the TFT substrate; and Each of the plurality of traces is vertically positioned over at least a portion of at least one of the plurality of data lines and overlaps in alignment with at least a portion of at least one of the plurality of data lines.

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