Organic light-emitting display panel

An organic light-emitting display panel includes a display area including pixels configured to display content, and a touch key area including at least one touch key configured to facilitate detection of a touch interaction.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean Patent Application No. 10-2013-0056041, filed on May 16, 2013, which is incorporated by reference for all purposes as if set forth herein.

BACKGROUND

Exemplary embodiments relate to display technology, and, more particularly, to organic light-emitting display panels.

The evolution in user interface technology has come with a switch from conventional physical user interface components (e.g., “hard” buttons, keys, switches, etc.) to virtual user interface components (e.g., “soft” buttons, keys, switches, etc.). In the mobile terminal (e.g., mobile phone, notebook computer, tablet, etc.) marketplace, these virtual user interface components may be realized in the form of, for example, touch-based input interfaces. One or more touch sensors are typically utilized in association with, for example, these “touch” components to detect whether a touch is input to (or on) a position of a touch screen panel or window corresponding to the touch component. In this manner, a touch component, such as a touch key, may be configured to perform a function conventionally provided by a physical button.

SUMMARY

Exemplary embodiments provide organic light-emitting display panels.

According to exemplary embodiments, an organic light-emitting display panel includes: a display area including pixels configured to display content; and a touch key area including at least one touch key configured to facilitate detection of a touch interaction.

According to exemplary embodiments, an organic light-emitting display panel includes: a substrate including a display area and a touch key area; pixels disposed in the display area; and at least one touch key disposed in the touch key area, the at least one touch key being configured to detect a touch interaction.

According to exemplary embodiments, the complexity, use of additional parts, increased manufacturing time, and related expenses associated with conventional, separately-formed display panels configured to facilitate implementation of one or more touch components may be decreased. In this manner, a device incorporating an exemplary organic light-emitting display panel may be more compact and sleek than traditional devices with separately-formed display panels configured to facilitate implementation of one or more touch components.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1is a plan view of an organic light-emitting display panel10, according to exemplary embodiments.FIG. 2is a cross-sectional view of the organic light-emitting display panel10taken along sectional line A-A′.

Referring toFIGS. 1 and 2, the organic light-emitting display panel10(hereinafter “display panel10”) includes a first substrate100and a second substrate200that is coupled (e.g., bonded) to the first substrate100via any suitable mechanism, e.g., one or more adhesives, chemical reactions, sealants, etc.

The first substrate100may be a flexible substrate and may be formed of a plastic material including, for example, polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), polyethylene naphthalate (PEN), polyarylate (PAR), polyetherimide (PEI), and/or the like. It is also contemplated that one or more fluropolymers (FEP), copolymers, and/or the like may be utilized. To this end, the material(s) may be selected in consideration of one or more electrical, mechanical, chemical, and thermal properties, e.g., to balance heat-resistance and durability of the first substrate100. Additionally (or alternatively), the first substrate100may be formed utilizing various materials, such as, for instance, metal, glass, etc.

The second substrate200may be an encapsulation substrate that is disposed on the first substrate100. In this manner, the second substrate200may be configured to block (or otherwise protect) a thin film transistor (TFT) and an organic light-emitting diode (OLED), which are disposed (or otherwise arranged) on the first substrate100, from one or more external forces (e.g., moisture, air, etc.) and/or contaminants (e.g., dust, debris, etc.). The second substrate200may be a flexible substrate, which may be similar to the first substrate100. To this end, the second substrate200may be formed using one or more of the various materials previously mentioned, such as, for instance, one or more plastic, metal, glass, etc., materials. It is also contemplated that the second substrate200may be a thin film encapsulate (TFE) substrate having a structure in which inorganic layers and organic layers are alternately stacked. As such, the second substrate200may be formed as a single or multilayer structure.

According to exemplary embodiments, the second substrate200is disposed on and faces the first substrate100. To this end, the second substrate200is coupled (e.g., bonded) to the first substrate100using a sealing member (not shown) that is arranged along a side edge of the second substrate200.

The first substrate100may be formed with one or more TFTs, OLEDs, and capacitors. As described herein, an array including one or more TFTs, one or more OLEDs, and one or more capacitors may be referred to as a “TFT array.”

As seen inFIG. 1, the first substrate100includes a display area DA and a touch key area TKA. The display area DA is configured to facilitate the display of content, such as various images, based on light emitted from one or more pixels PX of the display area DA. The touch key area TKA may be an outer region of the display area DA. For instance, the touch key area TKA may be disposed adjacent to the display area DA.

The display area DA includes a plurality of pixels PX. The pixels PX may be repeatedly disposed in column and row directions, such as in a matrix formation. It is contemplated, however, that any other suitable arrangement may be utilized. Each of the pixels PX may include a pixel circuit including a plurality of TFTs, a capacitor, and an OLED configured to emit light in response to receiving a driving current from the pixel circuit.

The touch key area TKA includes at least one touch-based interactive element (e.g., touch key) TK. The touch key area TKA may further include an emission unit (not shown) configured to emit light when a touch is detected in association with the touch key TK. The touch key area TKA may be formed in a region other than the display area DA of the first substrate100. As seen inFIG. 1, the touch key area TKA is formed at an upper region of the first substrate100disposed outside of and adjacent to the display area; however, it is contemplated that the touch key area TKA may be disposed in any suitable location.

According to exemplary embodiments, the display panel10includes a film formed with a driving circuit configured to supply a driving signal to the pixels PX connected to a side edge of the first substrate100. The film including the driving circuit may be a flexible printed circuit board (FPCB). Referring toFIG. 1, the FPCB is connected to a side edge of the first substrate100that is opposite to the side where the touch key area TKA is disposed. In this manner, the display area DA is disposed between the FPCB and the touch key area TKA. It is contemplated, however, that the FPCB may be alternatively disposed in any suitable position.

The FPCB is connected to a pad unit (not shown) having a pad electrically connected to a first driving line110of the display area DA and a second driving line120of the touch key area TKA. The FPCB includes a driving integrated circuit DIC configured to control operation of the display area DA and the touch key area TKA. Accordingly, by using one FPCB, it is possible to supply a control signal to control the driving of the display area DA via the first driving line110, to supply a control signal to control the driving of the touch key area TKA via the second driving line120, and to receive a touch detection signal from, for example, the touch key area TKA. As such, a dual purpose FPCB may be utilized, which eliminates a need to drive the touch key area TKA with a separate FPCB, and, in this manner, an associated manufacturing process may be simplified and corresponding costs may be reduced. The driving integrated circuit DIC may include a scan driving circuit (not shown) and a data driving circuit (not illustrated). The scan driving circuit is configured to supply a scan signal to a scan line of each pixel PX. The data driving circuit is configured to supply a data signal to a data line of each pixel PX. Also, the driving integrated circuit DIC may include a touch driving circuit to control (or otherwise facilitate) touch detection by the touch key TK and to control emission of the emission unit. The touch driving circuit is configured to supply a control signal to control the emission unit to emit light when a touch is detected in association with the touch key TK.

As seen inFIG. 1, each of the first driving line110and the second driving line120is formed as one line; however, it is contemplated that each of the first driving line110and the second driving line120may be formed as a plurality of lines. For example, the first driving line110may include any suitable number of lines to supply a scan signal S, a data signal D, a first power voltage ELVDD, and a second power voltage ELVSS to the various pixels PX of the display area DA. The second driving line120may include any suitable number of lines to supply a touch scan signal TS, a touch data signal TD, a first power voltage ELVDD, a second power voltage ELVSS, a touch transmission signal Tx, and a touch reception signal Rx to the various touch keys TK of the touch key area TKA.

FIG. 3is a circuit diagram of a pixel PX of the organic light-emitting display panel ofFIG. 1, according to exemplary embodiments.

Referring toFIG. 3, the pixel PX of the display area DA includes a first TFT T1, a second TFT T2, and a capacitor Cst. It is contemplated, however, that the pixel PX may be configured in any other suitable manner. For instance, the pixel PX may include any suitable number of TFTs, any suitable number of capacitors, and any suitable number of OLEDs. To this end, the structure of the pixel PX may include a different wiring scheme in which separate wirings are further formed, existing wires are not used, etc.

As seen inFIG. 3, the first TFT T1includes a gate electrode connected to a scan line configured to transmit the scan signal S, a first electrode connected to a data line configured to transmit the data signal D, and a second electrode connected to a first electrode of the capacitor Cst and a gate electrode of the second TFT T2. The second TFT T2includes a gate electrode connected to the gate electrode of the first TFT T1and the first electrode of the capacitor Cst, a first electrode connected to a line configured to supply the first power voltage ELVDD, and a second electrode connected to an anode electrode of an OLED. The capacitor Cst includes the first electrode connected to the first electrode of the first TFT T1and the gate electrode of the second TFT T2, and a second electrode connected to the line configured to supply the first power voltage ELVDD. The OLED has a structure in which the anode electrode is connected to the second electrode of the second TFT T2, and a cathode electrode is connected to a line that supplies a second power voltage ELVSS.

According to exemplary embodiments, when a scan signal S is supplied by the scan line to “turn on” the first TFT T1, the first TFT T1is able to transfer a data signal D, which is supplied from the data line, to the first electrode of the capacitor Cst. In this manner, the capacitor Cst may be charged by a voltage corresponding to the data signal D. A driving current corresponding to the voltage charged in the capacitor Cst may be delivered to the OLED via the second TFT T2to enable the OLED to emit light.

FIG. 4is a cross-sectional view of the pixel ofFIG. 3, according to exemplary embodiments. It is noted thatFIG. 4illustrates the respective cross-sections of the second TFT T2and the OLED. It is noted that the cross-section of the first TFT T1may be substantially similar to the second TFT T2, and, therefore, to avoid obscuring exemplary embodiments described herein, a duplicative description is not provided.

Referring toFIG. 4, a buffer layer101is formed on the first substrate100, and a pixel circuit including the second TFT T2is formed on the buffer layer101. The first substrate100may be formed from a plastic material having flexibility, or a flexible substrate formed of a metal foil, such as stainless steel (SUS), and/or the like. It is contemplated, however, that the first substrate100may be formed of any suitable material, such as, for example, a transparent glass material containing silicon oxide (SiOx) as a main component.

The buffer layer101may function to prevent penetration of foreign substances, and may also serve to planarize a surface of the first substrate100. The buffer layer101may be formed of various materials capable of performing the aforementioned functions. For example, the buffer layer101may be formed of an inorganic material including SiOx, silicon nitride (SixNy), silicon oxynitride (SiOxNy), aluminium oxide (AlxOy), aluminium nitride (AlN), titanium oxide (TixOy), titanium nitride (TiN), and/or the like, and/or an organic material including PI, polyester, acryl, and/or the like. It is also contemplated that the buffer layer101may be formed as a multilayer structure of the inorganic material and/or the organic material. It is noted that the buffer layer101may be omitted.

An active layer131is formed on the buffer layer101. The active layer131may be formed of an organic semiconductor material or an inorganic semiconductor material including, for instance, amorphous silicon, polysilicon, etc. The active layer131includes a source region, a drain region, and a channel region disposed between the source region and the drain region.

A gate insulating layer102is formed on the buffer layer101and covers the active layer131. A gate electrode133is formed on the gate insulating layer102and is disposed in correspondence with the channel region of the active layer131.

An interlayer insulating layer103is formed on the gate insulating layer102and covers the gate electrode133. A source electrode134and a drain electrode135are formed on the interlayer insulating layer103and contact the source region and the drain region of the active layer131, respectively, via corresponding contact holes (or vias).

Although the second TFT T2has been described as including the aforementioned structure, it is contemplated that any other suitable structure may be utilized.

As seen inFIG. 4, a passivation layer104is formed on the interlayer insulating layer103and covers the second TFT T2. The passivation layer104may be formed by singularly or multiply stacking insulating layers having a planarized top surface upon one another. The passivation layer104may be formed of any suitable material, such as, for instance, an inorganic material and/or an organic material.

An anode electrode141of the OLED, which is electrically connected to the second TFT T2, is formed on the passivation layer104. A pixel-defining layer (PDL)105is formed on the passivation layer104and covers one or more side edges of the anode electrode141. The PDL105includes an opening of a determined size, which partially exposes the anode electrode141.

An intermediate layer143, including an emission layer (EML), is formed on a top surface of the exposed anode electrode141. A cathode electrode145is formed on the intermediate layer143and the PDL105. To this end, it is noted that the cathode electrode145may cover the walls of the opening exposing the intermediate layer143.

FIG. 5schematically illustrates the touch key area TKA, according to exemplary embodiments.FIG. 6illustrates touch detection in association with the touch key area TKA ofFIG. 5, according to exemplary embodiments.FIGS. 7A and 7Bare circuit diagrams of an emission unit180of the touch key area TKA ofFIG. 5, according to exemplary embodiments.

Referring toFIG. 5, the touch key TK and the emission unit180configured to emit light in response to the touch detection are formed in the touch key area TKA. The touch key TK includes a first (e.g., transmission) electrode171and a second (e.g., reception) electrode173. The touch key TK and the emission unit180may be formed as a set, and the set of the touch key TK and the emission unit180may be independently driven and may emit light. It is noted that a number, a size, and a position of the set of the touch key TK and the emission unit180may vary according to a design and an application of a display apparatus.

As illustrated inFIG. 5, the transmission electrode171and the reception electrode173of the touch key TK face each other on the same layer and are spaced apart from one another by a determined distance. The electrode patterns of the transmission electrode171and the reception electrode173have a semi-circular shape; however, it is contemplated that any suitable shape may be utilized, such as, for instance, a rhombic shape, a quadrangular shape, a diamond shape, a line shape, and/or the like. A capacitance may be formed between the transmission electrode171and the reception electrode173.

Referring toFIG. 6, a transmission signal Tx having a constant value may be periodically applied to the transmission electrode171. In this manner, an electric field may be formed between the transmission electrode171and the reception electrode173, such that a capacitance C1is formed. A reception signal RX corresponding to the capacitance C1is output from the reception electrode173. When a user's finger (or other touch tool) approaches the touch key TK so as to input a touch, capacitance C1between the transmission electrode171and the reception electrode173is changed to capacitance C1′ due to the conductivity of the human body. To this end, a reception signal RX' corresponding to the changed capacitance C1′ is output from the reception electrode173, which enables the touch to be detected.

According to exemplary embodiments, when the touch is detected, a function that is allocated to the touch key TK may be performed. The function that is allocated to the touch key TK may be based on combination of a total number of touches, a touch duration time, and/or the like. It is noted that the function(s) may be allocated based on the application of an apparatus including the organic light-emitting display panel10.

Also, when the touch is detected, a touch OLED TOLED of the emission unit180may emit light in conjunction with the touch key TK. In this manner, the user may recognize the touch key TK that the user has touched. It is noted that the emission of the light by the touch key TK may be aesthetically pleasing to the user. The emission unit180may be formed around the touch key TK or may be disposed between the transmission electrode171and the reception electrode173of the touch key TK.

As illustrated inFIG. 7A, the emission unit180may include a touch TFT TT and the touch OLED TOLED. The touch TFT TT may include a gate electrode connected to a touch scan line, a first electrode connected to a touch data line, and a second electrode connected to an anode electrode of the touch OLED TOLED. The touch OLED TOLED may include the anode electrode connected to the second electrode of the touch TFT TT and a cathode electrode connected to a line that supplies a second power voltage ELVSS.

According to exemplary embodiments, when the touch is detected and a touch scan signal TS is supplied from the touch scan line, the touch TFT TT provides a touch data signal TD, which is supplied from the touch data line, to the anode electrode of the touch OLED TOLED. In this manner, the touch OLED TOLED is configured to emit light in response to a current that corresponds to the voltage difference between the anode electrode and the cathode electrode of the touch OLED TOLED. It is noted that the touch OLED TOLED is configured to emit light of a determined wavelength according to an emission layer forming material. To this end, the brightness of the touch OLED TOLED is based on the touch data signal TD.

The second power voltage ELVSS applied to the cathode electrode of the touch OLED TOLED corresponds to the second power voltage ELVSS applied to the OLED included in each pixel PX of the display area DA. Since power voltages used to drive the display area DA are used by the touch key area TKA, an additional external signal is not necessarily required, but may be utilized if desired.

As illustrated inFIG. 7B, the emission unit180may include a touch TFT TT, a touch capacitor TC, and the touch OLED TOLED. The touch TFT TT may include a gate electrode connected to a touch data line, a first electrode connected to a line that supplies a first power voltage ELVDD, and a second electrode connected to an anode electrode of the touch OLED TOLED. The touch capacitor TC may include a first electrode connected to the gate electrode of the touch TFT TT and a second electrode connected to the line that supplies the first power voltage ELVDD. The touch OLED TOLED may include the anode electrode connected to the second electrode of the touch TFT TT and a cathode electrode connected to a line that supplies a second power voltage ELVSS.

According to exemplary embodiments, when a touch is detected, and, as such, a touch data signal TD is supplied from the touch data line to the touch capacitor, the touch capacitor TC is charged by a voltage corresponding to the touch data signal TD. Further, the touch TFT TT is “turned on,” which enables the touch OLED TOLED to emit light based on a current corresponding to the voltage charged in the touch capacitor TC. To this end, the touch OLED TOLED is configured to emit light of a determined wavelength based on an emission layer forming material at a brightness according to the touch data signal TD.

The first power voltage ELVDD and the second power voltage ELVSS applied to the respective electrodes of the touch OLED TOLED correspond to the first power voltage ELVDD and the second power voltage ELVSS applied to the OLED included in each pixel PX of the display area DA. That is, since power voltages that are used in driving the display area DA are used in the touch key area, an additional external signal is not necessarily required, but may be utilized as desired.

Although the emission unit180has been described as including the aforementioned structure shown inFIGS. 7A and 7B, it is contemplated that any other suitable structure may be utilized. For instance, the emission unit180may have the same structure as each pixel PX of the display area DA illustrated inFIG. 3.

FIG. 8is a cross-sectional view of the touch key area TKA, according to exemplary embodiments. It is noted that the touch capacitor TC is not illustrated inFIG. 8.

Referring toFIG. 8, the buffer layer101is formed on the first substrate100, and the touch TFT TT and the touch capacitor TC are formed on the buffer layer101. The touch TFT TT and the touch capacitor TC may be formed via a process that is the same as a process of forming a TFT and a capacitor of the pixel circuit of the display area DA.

The first substrate100may be formed from a plastic material having flexibility, or a flexible substrate formed of a metal foil, such as SUS, and/or the like. It is contemplated, however, that the first substrate may be formed of any suitable material, such as, for example, a transparent glass material containing SiOxas a main component.

The buffer layer101may function to prevent penetration of foreign substances, and may also serve to planarize a surface of the first substrate100. The buffer layer101may be formed of various materials capable of performing the aforementioned functions. For example, the buffer layer101may be formed of an inorganic material including SiOx, SixNy, SiOxNy, AlxOy, AlN, TixOy, TiN, and/or the like, and/or an organic material including PI, polyester, acryl, and/or the like. It is also contemplated that the buffer layer101may be formed as a multilayer structure of the inorganic material and/or the organic material. It is noted that the buffer layer101may be omitted.

An active layer151is formed on the buffer layer101. The active layer151may be formed of an organic semiconductor material or an inorganic semiconductor material including, for example, amorphous silicon, polysilicon, etc. The active layer151includes a source region, a drain region, and a channel region disposed between the source region and the drain region.

A gate insulating layer102is formed on the buffer layer101and covers the active layer151. A gate electrode153is formed on the gate insulating layer102and is disposed in correspondence with the channel region of the active layer151.

An interlayer insulating layer103is formed on the gate insulating layer102and covers the gate electrode153. A source electrode154and a drain electrode155are formed on the interlayer insulating layer103and contact the source region and the drain region of the active layer151, respectively, via corresponding contact holes (or vias). As seen inFIG. 8, a transmission electrode171and a reception electrode173of the touch key TK may be formed on the same layer and of the same material as the source electrode154and the drain electrode155.

Although the touch TFT TT has been described as including the aforementioned structure, it is contemplated that any other suitable structure may be utilized.

As seen inFIG. 8, the passivation layer104is formed on the interlayer insulating layer103and covers the touch TFT TT. The passivation layer104may be formed by singularly or multiply stacking insulating layers having a planarized top surface upon one another. The passivation layer104may be formed of any suitable material, such as, for example, an inorganic material and/or an organic material.

An anode electrode161of the touch OLED TOLED, which is electrically connected to the touch TFT TT, is formed on the passivation layer104. The PDL105is formed on the passivation layer104and covers one or more side edges of the anode electrode161. The PDL105includes an opening of a determined size, which partially exposes the anode electrode161.

An intermediate layer163, including an EML, is formed on a top surface of the exposed anode electrode161. A cathode electrode165is formed on the intermediate layer163and the PDL105. A portion of the cathode electrode165, which is formed in a region including the touch key TK, may be removed.

According to exemplary embodiments, the transmission electrode171and the reception electrode173may be formed from the same material layer as the source electrode154and the drain electrode155. It is contemplated, however, that the transmission electrode171and the reception electrode173may be formed from the same material layer as the gate electrode153, the anode electrode161, and/or the cathode electrode165. Also, the touch OLED TOLED ofFIG. 8is shown as being disposed around the transmission electrode171and the reception electrode173. It is contemplated, however, that the touch OLED TOLED may be disposed between the transmission electrode171and the reception electrode173.

FIG. 9is an exploded perspective view of an organic light-emitting display apparatus, according to exemplary embodiments.

Referring toFIG. 9, the organic light-emitting display apparatus1may include a housing20, the display panel10housed (or otherwise supported) in the housing20, and a window30, which may be combined to a top portion of the display panel10. In this manner, the housing20may be configured to house (or otherwise support) the display panel10and the window30.

The display panel10is formed with an OLED, a FPCB, and various electronic parts so as to display content according to a user control. The display panel10may further include a touch screen panel that is attached to an exterior surface of the display panel10. The display panel10may be wholly or partially arranged in the housing20. The display panel10may be fixed in the housing20using one of any suitable methods.

The touch screen panel may be disposed to correspond to the display area DA of the display panel10, other than the touch key area TKA of the display panel10. The touch screen panel is an input device by which a user may input a command to, for example, select instruction content on a screen with the hand, an object, or any other interaction tool. In this manner, the touch screen panel may be arranged on a front face of the display panel10and may be configured to convert a contact position that the user directly contacts with the hand, object, or tool into an electrical signal. To this end, instruction content that is selected at the contact position may be recognized as an input signal. The touch screen panel may replace a separate input device, such as a keyboard, a mouse, or the like. The touch screen panel may be embodied as a resistive-type touch screen panel, a beam sensing-type touch screen panel, a capacitive-type touch screen panel, and/or the like. In this manner, when the user's hand, object, or tool contacts the capacitive-type touch screen panel, the capacitive-type touch screen panel senses variation of capacitance formed between a conductive sensing pattern and another adjacent sensing pattern or between the conductive sensing pattern and a ground electrode. As such, the capacitive-type touch screen panel is configured to convert a contact position into an electrical signal.

To improve mechanical strength, the window30may be additionally arranged on the top surface of the display panel10. The window30may be configured to prevent damage, such as a scratch, on the display panel10, as well as configured to prevent penetration of foreign substances and protect the display panel10from external shock. Also, when the display panel10has flexibility, the window30may be formed of a plastic material having suitable heat-resistance and durability, or may be formed of a reinforced transparent glass material. The window30may be formed with a symbol or a mark corresponding to the touch key TK of the display panel10.

It is noted that the aforementioned display apparatus may be alternatively configured in any other suitable manner to include the display panel10including the touch key area TKA. For example, a touch sensor may be formed in an area corresponding to the display area DA of the first substrate100, in the second substrate200of the display panel10, so that an additional touch screen panel is not necessarily required, but may be used if desired. As another example, a touch sensor may be formed in an area of the window30corresponding to the display area DA of the first substrate100, so that an additional touch screen panel may not be necessarily required, but may be used if desired.

According to exemplary embodiments, the touch key TK and the touch OLED TOLED may be formed at a side of the display panel10by forming a pixel PX in the display area DA of the display panel10, and, as such, the touch key TK may be embedded in the display panel10without additional manufacturing processes or using additional parts. In this manner, the touch key TK may be embedded as part of the display panel10, such that conventional increased costs due to the addition of a part may be decreased, utilization of a product design may be improved, and the display apparatus may be more compact.