Patent ID: 12249281

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which embodiments of the invention are shown. This invention may, however, be embodied in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

It will also be understood that when a layer is referred to as being “on” another layer or substrate, it can be directly on the other layer or substrate, or intervening layers may also be present. The same reference numbers indicate the same components throughout the specification.

It will be understood that, although the terms “first,” “second,” etc. may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For instance, a first element discussed below could be termed a second element without departing from the teachings of the present invention. Similarly, the second element could also be termed the first element.

Each of the features of the various embodiments of the present disclosure may be combined or combined with each other, in part or in whole, and technically various interlocking and driving are possible. Each embodiment may be implemented independently of each other or may be implemented together in an association.

Hereinafter, specific embodiments will be described with reference to the accompanying drawings.

FIG.1is a perspective view of a display device10according to an embodiment.FIG.2is a plan view illustrating the arrangement structure of a display panel100and a display driving circuit illustrated inFIG.1.

Referring toFIGS.1and2, the display device10according to the embodiment may be applied to portable electronic devices such as mobile phones, smartphones, tablet personal computers (PCs), mobile communication terminals, electronic notebooks, electronic books, portable multimedia players (PMPs), navigation devices, and ultra-mobile PCs (UMPCs). Alternatively, the display device10according to the embodiment may be applied as a display unit of a television, a laptop computer, a monitor, a billboard, or an Internet of things (IoT) device. Alternatively, the display device10according to the embodiment may be applied to wearable devices such as smart watches, watch phones, glass-like displays, and head-mounted displays (HMDs). Alternatively, the display device10according to the embodiment may be applied to a dashboard of a vehicle, a center fascia of a vehicle, a center information display (CID) disposed on a dashboard of a vehicle, or a display disposed on the back of a front seat as an entertainment for rear-seat passengers of a vehicle.

The display device10may be a light emitting display device such as an organic light emitting display device using an organic light emitting diode, a quantum dot light emitting display device including a quantum dot light emitting layer, an inorganic light emitting display device including an inorganic semiconductor, or a micro- or nano-light emitting display device using a micro- or nano-light emitting diode. A case where the display device10is an organic light emitting display device will be mainly described below, but the present disclosure is not limited thereto.

The display panel100may be shaped like a rectangular plane having short sides in a first direction DR1and long sides in a second direction DR2intersecting the first direction DR1. Each corner where a short side extending in the first direction DR1meets a long side extending in the second direction DR2may be right-angled or may be rounded with a predetermined curvature. The planar shape of the display panel100is not limited to a quadrilateral shape but may also be another polygonal shape, a circular shape, or an oval shape. The display panel100may be formed flat, but the present disclosure is not limited thereto. For example, the display panel100may include curved portions formed at left and right ends and having a constant or varying curvature. In addition, the display panel100may be formed to be flexible so that it can be curved, bent, folded, or rolled.

A substrate SUB of the display panel100may be divided into a main area MA and a sub-area SBA.

The main area MA may be divided into a display area DA displaying an image and a non-display area NDA located around the display area DA.

The non-display area NDA may neighbor the display area DA. The non-display area NDA may be an area outside the display area DA. The non-display area NDA may surround the display area DA. The non-display area NDA may be an edge area of the display panel100. In an embodiment, no pixels are present in the non-display area NDA.

The display area DA includes display pixels for displaying an image, infrared light emitting pixels for emitting infrared light, and light sensing pixels for sensing light reflected from an object placed in front, such as a part of a user's body (e.g., a finger, the back of a hand, a wrist, scalp, facial skin, etc.), a vegetable, a fruit or a plant. For example, the object may be placed in front of the display area DA. The display pixels, the infrared light emitting pixels, and the light sensing pixels may be alternately disposed according to a preset arrangement order and may be evenly disposed throughout the display area DA. The display area DA may occupy most of the main area MA. The display area DA may be disposed in a center of the main area MA.

The sub-area SBA may include a first area A1, a second area A2, and a bending area BA.

The first area A1is an area protruding from a side of the main area MA in the second direction DR2. A side of the first area A1may contact the non-display area NDA of the main area MA, and the other side of the first area A1may contact the bending area BA.

The second area A2is an area in which pads DP and a main driving circuit200are disposed. The main driving circuit200may be attached to driving pads of the second area A2using a conductive adhesive member such as an anisotropic conductive film. A circuit board300may be attached to the pads DP of the second area A2using a conductive adhesive member. A side of the second area A2may contact the bending area BA.

The bending area BA is an area that is bent. When the bending area BA is bent, the second area A2may be disposed under the first area A1and under the main area MA. The bending area BA may be disposed between the first area A1and the second area A2. A side of the bending area BA may contact the first area A1, and the other side of the bending area BA may contact the second area A2.

FIG.3is a plan view illustrating the arrangement structure of a display panel100and a display driving circuit according to an embodiment.FIG.4is a plan view illustrating the arrangement structure of a display panel100and a display driving circuit according to an embodiment.

Referring toFIG.3, a display area DA may be divided into an image display area IDA in which only display pixels are disposed without infrared light emitting pixels and light sensing pixels and a reflected light sensing area FSA in which a combination of display pixels, infrared light emitting pixels, and light sensing pixels are disposed. In other words, the infrared light emitting pixels and the light sensing pixels may be disposed together with the display pixels only in a preset reflected light sensing area FSA of the display area DA of the display panel100.

Referring toFIG.4, a display area DA may be divided into an image display area IDA in which only display pixels are disposed and a plurality of reflected light sensing areas FSA1and FSA2in which display pixels, infrared light emitting pixels and light sensing pixels are disposed. In other words, a reflected light sensing area FSA in which a combination of infrared light emitting pixels and light sensing pixels are disposed together with display pixels may be divided into a plurality of reflected light sensing areas FSA1and FSA2, for example, first and second reflected light sensing areas FSA1and FSA2. The first and second reflected light sensing areas FSA1and FSA2may be formed at different positions, that is, in different areas of the display area DA. The structure of an example in which infrared light emitting pixels and light sensing pixels are alternately disposed together with display pixels in the entire display area DA will be described below. WhileFIG.4shows two separate light sensing areas, there may be more than two light sensing areas in alternate embodiments.

FIG.5is a detailed side view of the display device10according to the embodiment.

Referring toFIGS.4and5, the sub-area SBA may be bent, and in this case, may be disposed under the main area MA. The sub-area SBA may overlap the main area MA in a third direction DR3.

A length or area of the sub-area SBA in the first direction DR1may be smaller than a length or area of the main area MA in the first direction DR1or may be substantially equal to the length or area of the main area MA in the first direction DR1. The sub-area SBA may be bent, and in this case, may be disposed under the main area MA. The sub-area SBA may overlap the main area MA in the third direction DR3.

A touch sensing unit TSU for sensing a touch position of a body part such as a finger, a stylus pen, or an electronic pen may be disposed in a front portion of the display panel100including the display area DA. The touch sensing unit TSU may include a plurality of touch electrodes to sense a user's touch in a capacitive manner.

The touch sensing unit TSU includes a plurality of touch electrodes arranged to cross each other in the first and second directions DR1and DR2. Specifically, the touch electrodes may be formed to extend in a wiring area (or a non-image display area in which wirings are formed) between display pixels so as not to overlap the display pixels, infrared light emitting pixels and light sensing pixels arranged in the display area DA. The touch electrodes may form mutual capacitance to transmit touch sensing signals, which vary according to a user's touch, to a touch sensing circuit500.

The touch sensing circuit500may sense a change in mutual capacitance between the touch electrodes input from the touch electrodes, generate touch data according to the change in capacitance and coordinate data of a position where a touch has been sensed, and supply the generated data to the main driving circuit200.

The circuit board300may be attached to an end of the sub-area SBA. The touch sensing circuit500may be mounted on the circuit board300and electrically connected to the touch electrodes of the touch sensing unit TSU. In addition, the circuit board300may be electrically connected to the display panel100and the main driving circuit200.

The display panel100and the main driving circuit200may receive digital video data, timing signals, and driving voltages through the circuit board300. The circuit board300may be a flexible printed circuit board, a printed circuit board, or a flexible film such as a chip on film.

The main driving circuit200may generate digital data and electrical control signals for driving the display panel100. Each of a component detection circuit400and the touch sensing circuit500as well as the main driving circuit200may be formed as an integrated circuit. Each of the main driving circuit200, the component detection circuit400, and the touch sensing circuit500may be attached onto the display panel100or the circuit board300using a chip on glass (COG) method, a chip on plastic (COP) method, or an ultrasonic bonding method. However, the present disclosure is not limited thereto. For example, the component detection circuit400and the touch sensing circuit500as well as the main driving circuit200may also be attached onto the circuit board300using a chip on film (COF) method.

FIG.6is a schematic layout view of an example of the display panel100illustrated inFIGS.1through5. Specifically,FIG.6is a layout view illustrating the display area DA and the non-display area NDA of a display module DU before the touch sensing unit TSU is formed.

Referring toFIG.6, a display scan driver110, a light sensing scan driver120, and the main driving circuit200may be disposed on the display panel100of the display device10according to the embodiment. In addition, the component detection circuit400, the touch sensing circuit500, and a power supply unit (not illustrated) may be disposed on the circuit board300connected to the display panel100. Here, the main driving circuit200, the component detection circuit400, and the touch sensing circuit500may be integrally formed as a one-chip type and mounted on the display panel100or the circuit board300. However, for ease of functional description, an example in which the main driving circuit200, the component detection circuit400, and the touch sensing circuit500are formed as different integrated circuits will be described below.

The display panel100may include display pixels SP, infrared light emitting pixels ESP, light sensing pixels LSP, display scan wirings GL, emission control wirings EL, data wirings DL, light sensing scan wirings FSL, and light sensing signal wirings ERL disposed in the display area DA. Each of the display scan driver110and the light sensing scan driver120may be disposed in the non-display area NDA.

The display scan wirings GL sequentially supply display scan signals received from the display scan driver110in units of horizontal lines to a plurality of display pixels SP for each horizontal line. In addition, the display scan signals may be supplied to the infrared light emitting pixels ESP through the display scan wirings GL. The display scan wirings GL may extend in the first direction DR1and may be spaced apart from each other in the second direction DR2intersecting the first direction DR1.

The emission control wirings EL sequentially supply emission control signals received from the display scan driver110in units of horizontal lines to a plurality of display pixels SP for each horizontal line. In addition, the emission control signals may be supplied to the infrared light emitting pixels ESP through the emission control wirings EL. The emission control wirings EL may extend in the first direction DR1in parallel with the display scan wirings GL and may be spaced apart from each other in the second direction DR2intersecting the first direction DR1.

The data wirings DL may supply data voltages received from the main driving circuit200to the display pixels SP and the infrared light emitting pixels ESP. The data wirings DL may extend in the second direction DR2and may be spaced apart from each other in the first direction DR1.

The light sensing scan wirings FSL sequentially supply sensing scan signals received from the light sensing scan driver120in units of horizontal lines to the light sensing pixels LSP. The light sensing scan wirings FSL may extend in the first direction DR1and may be spaced apart from each other in the second direction DR2intersecting the first direction DR1.

The light sensing signal wirings ERL are connected between the light sensing pixels LSP and the component detection circuit400to supply light sensing signals output from the light sensing pixels LSP to the component detection circuit400. The light sensing signal wirings ERL may lie and extend in the second direction DR2according to the placement direction of the component detection circuit400and may be spaced apart from each other in the first direction DR1.

The non-display area NDA may surround the display area DA. The display scan driver110, the light sensing scan driver120, fan-out wirings FOL, display control wirings GCL, and light sensing control wirings SCL may be disposed in the non-display area NDA.

The display pixels SP displaying an image, the infrared light emitting pixels ESP emitting infrared light, and the light sensing pixels LSP sensing reflected light incident from a front side may be arranged in a matrix in the first direction DR1and the second direction DR2. For example, the reflected light may be light reflected from an objected located in front of the display area DA. For example, the display pixels SP, the infrared light emitting pixels ESP, and the light sensing pixels LSP may be arranged in a horizontal stripe structure along the first direction DR1or may be arranged in a vertical stripe structure along the second direction DR2.

The display scan driver110may be disposed in the non-display area NDA. Although the display scan driver110is disposed on a side (e.g., a left side) of the display panel100in the drawing, the present disclosure is not limited thereto. For example, the display scan driver110may also be disposed on both sides (e.g., left and right sides) of the display panel100.

The display scan driver110may be electrically connected to the main driving circuit200through the display control wirings GCL. The display scan driver110receives a scan control signal from the main driving circuit200, sequentially generates display scan signals in units of horizontal line driving periods according to the scan control signal, and sequentially supplies the display scan signals to the display scan wirings GL. In addition, the display scan driver110may sequentially generate emission control signals according to the scan control signal from the main driving circuit200and sequentially supply the emission control signals to the emission control wirings EL.

The display control wirings GCL may extend from the main driving circuit200to the display scan driver110according to the placement position of the display scan driver110. The display control wirings GCL may supply a scan control signal received from the main driving circuit200to the display scan driver110.

The light sensing scan driver120may be disposed in a different part of the non-display area NDA from the display scan driver110. Although the light sensing scan driver120is disposed on the other side (e.g., the right side) of the display panel100inFIG.6, the present disclosure is not limited thereto. The light sensing scan driver120may be electrically connected to the main driving circuit200through the light sensing control wirings SCL. The light sensing scan driver120receives a light sensing control signal from the main driving circuit200and sequentially generates reset control signals and sensing scan signals in units of horizontal line driving periods according to the light sensing control signal. Then, the light sensing scan driver120sequentially supplies the sequentially generated reset control signals to sensing reset wirings. In addition, the light sensing scan driver120may sequentially generate sensing scan signals according to the light sensing control signal from the main driving circuit200and sequentially supply the sensing scan signals to the light sensing scan wirings FSL.

The light sensing control wirings SCL may extend from the main driving circuit200to the light sensing scan driver120according to the placement position of the light sensing scan driver120. The light sensing control wirings SCL may supply a light sensing control signal received from the main driving circuit200to the light sensing scan driver120.

The main driving circuit200may output signals and voltages for driving the display panel100to the fan-out wirings FOL. The main driving circuit200may supply data voltages to the data wirings DL through the fan-out wirings FOL. The data voltages may be supplied to the display pixels SP and may determine luminances of the display pixels SP. The main driving circuit200may supply a scan control signal to the display scan driver110through the display control wirings GCL.

The main driving circuit200may generate digital video data according to biomarker information analyzed by the component detection circuit400or may execute an application program that presents the biomarker information (e.g., in text or graphic form). For example, the biomarker information may be determined by the component detection circuit400. For example, the main driving circuit200may execute an application program or a preset program and present the biomarker information in text or graphic form according to the graphic form and type of the program.

In an embodiment, the component detection circuit400modulates light sensing signals of the light sensing pixels LSP received through the light sensing signal wirings ERL into digital light sensing signals. Then, the component detection circuit400generates and stores biomarker information by analyzing the digital light sensing signals using a preset component analysis algorithm or component analysis program. The biomarker information may be transmitted to and shared with the main driving circuit200.

FIG.7is a layout view illustrating the arrangement structure of display pixels SP, infrared light emitting pixels ESP, and light sensing pixels LSP in a reflected light sensing area FAS according to an embodiment.

Referring toFIG.7, in the display area DA or the reflected light sensing area FAS of the display area DA according to the embodiment, two display pixels, i.e., first and second display pixels SP1and SP2respectively displaying red light and green light, one infrared light emitting pixel ESP, and one light sensing pixel LSP may be arranged to form a first unit pixel PG1. In addition, two display pixels, i.e., second and third display pixels SP2and SP3respectively displaying green light and blue light, one infrared light emitting pixel ESP, and one light sensing pixel LSP may be arranged to form a second unit pixel PG2. The first and second unit pixels PG1and PG2may be arranged in a quad structure or a Pentile™ matrix structure.

For example, the first and second unit pixels PG1and PG2may alternately be arranged in a zigzag pattern along the first direction DR1and the second direction DR2. In addition, the first and second unit pixels PG1and PG2may be alternately arranged in a matrix along the first direction DR1and the second direction DR2. Alternatively, the first and second unit pixels PG1and PG2may be alternately arranged in a Pentile™ matrix along the first direction DR1and the second direction DR2.

FIG.8is a layout view illustrating the arrangement structure of display pixels SP, infrared light emitting pixels ESP, and light sensing pixels LSP in a reflected light sensing area FAS according to an embodiment.

Referring toFIG.8, in the display area DA or the reflected light sensing area FAS of the display area DA according to the embodiment, three display pixels, i.e., first through third display pixels SP1through SP3respectively displaying red light, green light and blue light and one infrared light emitting pixel ESP are arranged to form each first unit pixel PG1. In addition, three display pixels, i.e., first through third display pixels SP1through SP3respectively displaying red light, green light and blue light and one light sensing pixel LSP are arranged to form each second unit pixel PG2. Accordingly, the first and second unit pixels PG1and PG2may be alternately arranged in a matrix along the first direction DR1and the second direction DR2. The first and second unit pixels PG1and PG2may be arranged in a quad structure or a Pentile™ matrix structure.

For example, the first and second unit pixels PG1and PG2may be alternately arranged in the form of vertical or horizontal stripes along the first direction DR1and the second direction DR2. In addition, the first and second unit pixels PG1and PG2may be alternately arranged in a zigzag pattern along the first direction DR1and the second direction DR2. Alternatively, the first and second unit pixels PG1and PG2may be alternately arranged in a Pentile™ matrix along the first direction DR1and the second direction DR2.

As another example, three display pixels SP1through SP3respectively displaying red light, green light and blue light, one infrared light emitting pixel ESP, and one light sensing pixel LSP may form each unit pixel and may be arranged along the first direction DR1and the second direction DR2.

Each of the red, green and blue display pixels SP1through SP3and the infrared light emitting pixels ESP may be connected to any one of the display scan wirings GL and any one of the emission control wirings EL.

Each of the display pixels SP1through SP3may receive a data voltage of a data wiring DL according to a display scan signal of a display scan wiring GL and an emission control signal of an emission control wiring EL and may emit light by supplying a driving current to a light emitting element according to the data voltage. Each of the infrared light emitting pixels ESP may also receive a data voltage of a data wiring DL according to a display scan signal and an emission control signal and may emit light by supplying a driving current to a light emitting element according to the data voltage. The data voltage applied to each of the infrared light emitting pixels ESP may be the same voltage as the data voltage applied to each of the blue third display pixels SP3.

Each of the light sensing pixels LSP may be connected to one of the light sensing scan wirings FSL and one of the light sensing signal wirings ERL. Each of the light sensing pixels LSP may generate a light sensing signal corresponding to the amount of reflected light incident from the front side and transmit the light sensing signal to a light sensing signal wiring ERL in response to a sensing scan signal from a light sensing scan wiring FSL.

FIG.9is a detailed layout view of an area where display pixels SP, infrared light emitting pixels ESP, and light sensing pixels LSP are arranged according to an embodiment.

Referring toFIG.9, a first unit pixel PG1including first and second display pixels SP1and SP2, an infrared light emitting pixel ESP and a light sensing pixel LSP and a second unit pixel PG2including second and third display pixels SP2and SP3, an infrared light emitting pixel ESP and a light sensing pixel LSP may be alternately arranged in the display area DA.

In other words, the first display pixel SP1, the second display pixel SP2, one infrared light emitting pixel ESP, and one light sensing pixel LSP may be defined as the first unit pixel PG1. In addition, the second display pixel SP2, the third display pixel SP3, one infrared light emitting pixel ESP, and one light sensing pixel LSP may be defined as the second unit pixel PG2. Each of the first and second unit pixels PG1and PG2may be defined as a minimum unit of subpixels that can display white while emitting infrared light or sensing reflected light incident from the front side.

The first display pixel SP1of the first unit pixel PG1may include a first light emitting unit ELU1emitting first light and a first pixel driving unit DDU1for supplying a driving current to a light emitting element of the first light emitting unit ELU1. The first light may be light of a red wavelength band. For example, a main peak wavelength of the first light may range from 600 nm to 750 nm or from approximately or about 600 nm to approximately or about 750 nm.

The second display pixel SP2may include a second light emitting unit ELU2emitting second light and a second pixel driving unit DDU2for supplying a driving current to a light emitting element of the second light emitting unit ELU2. The second light may be light of a green wavelength band. For example, a main peak wavelength of the second light may range from 480 nm to 560 nm or from approximately or about 480 nm to approximately or about 560 nm. The second display pixel SP2may be included in each of the first and second unit pixels PG1and PG2.

The third display pixel SP3of the second unit pixel PG2may include a third light emitting unit ELU3emitting third light and a third pixel driving unit DDU3for supplying a driving current to a light emitting element of the third light emitting unit ELU3. The third light may be light of a blue wavelength band. For example, a main peak wavelength of the third light may range from 370 nm to 460 nm or from approximately or about 370 nm to approximately or about 460 nm.

The infrared light emitting pixel ESP included in each of the first and second unit pixels PG1and PG2may include a fourth light emitting unit ELU4emitting infrared light and a fourth pixel driving unit DDU4for supplying a driving current to a light emitting element of the fourth light emitting unit ELU4. The infrared light emitted from the fourth light emitting unit ELU4may be light in a wavelength band ranging from 750 nm to 900 nm or ranging from approximately or about 750 nm to approximately or about 900 nm. Alternatively, the fourth light emitting unit ELU4may emit the third light in the blue wavelength band (e.g., 370 to 460 nm), like the third light emitting unit ELU3of the third display pixel SP3. When the fourth light emitting unit ELU4emits light in the blue wavelength band, a wavelength conversion layer may be further formed on a front surface (or upper surface) of the fourth light emitting unit ELU4to shift the light in the blue wavelength band to light in an infrared wavelength band and output the light in the infrared wavelength band.

The light sensing pixel LSP included in each of the first and second unit pixels PG1and PG2includes a light sensing unit PDU sensing reflected light incident from the front side and a sensing driving unit FDU transmitting a light sensing signal from the light sensing unit PDU. The detailed structure of the infrared light emitting pixel ESP included in each of the first and second unit pixels PG1and PG2is the same as the detailed structure of the first through third display pixels SP1through SP3. In an embodiment, an organic light emitting material included in the fourth light emitting unit ELU4of the infrared light emitting pixel ESP is different from organic light emitting materials included in the first through third light emitting units ELU1through ELU3.

As illustrated inFIG.9, the first light emitting unit ELU1, the second light emitting unit ELU2, the third light emitting unit ELU3, the fourth light emitting unit ELU4, and the light sensing unit PDU may have an octagonal planar shape. However, the present disclosure is not limited thereto. The first light emitting unit ELU1, the second light emitting unit ELU2, the third light emitting unit ELU3, the fourth light emitting unit ELU4, and the light sensing unit PDU may also have a quadrilateral planar shape such as a rhombus or a polygonal planar shape other than a quadrilateral and an octagon.

In addition, due to the placement positions and planar shapes of the first light emitting unit ELU1, the second light emitting unit ELU2, the third light emitting unit ELU3, and the fourth light emitting unit ELU4(or the light sensing unit PDU), a distance between a center of the first light emitting unit ELU1and a center of the fourth light emitting unit ELU4(or the light sensing unit PDU) neighboring each other and a distance between a center of the second light emitting unit ELU2and the center of the fourth light emitting unit ELU4(or the light sensing unit PDU) neighboring each other may be substantially the same.

FIG.10is a cross-sectional view of the display area DA taken along line I-I′ ofFIG.7. Specifically,FIG.10is a cross-sectional view illustrating a portion of a cross section of the fourth light emitting unit ELU4and the fourth pixel driving unit DDU4of an infrared light emitting pixel ESP, the third light emitting unit ELU3and the third pixel driving unit DDU3, and the light sensing unit PDU and the sensing driving unit FDU.

Referring toFIG.10, a barrier layer BR may be disposed on a substrate SUB. The substrate SUB may be made of an insulating material such as polymer resin. For example, the substrate SUB may be made of polyimide. The substrate SUB may be a flexible substrate that can be bent, folded, rolled, or the like.

The barrier layer BR is a layer for protecting transistors of a thin-film transistor layer TFTL and light emitting layers172of a light emitting element layer EML from moisture introduced through the substrate SUB which is vulnerable to moisture penetration. The barrier layer BR may be composed of a plurality of inorganic layers stacked alternately. For example, the barrier layer BR may be a multilayer in which one or more inorganic layers selected from a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and an aluminum oxide layer are alternately stacked.

Thin-film transistors ST1of pixel driving units and sensing transistors SRT of sensing driving units FDU may be disposed on the barrier layer BR. Each of the thin-film transistors ST1and the sensing transistors SRT includes an active layer ACT1, a gate electrode G1, a source electrode S1, and a drain electrode D1.

For example, the active layers ACT1, the source electrodes S1, and the drain electrodes D1of the thin-film transistors ST1may be disposed on the barrier layer BR. The active layers ACT1of the thin-film transistors ST1include polycrystalline silicon, monocrystalline silicon, low-temperature polycrystalline silicon, amorphous silicon, or an oxide semiconductor. The active layers ACT1overlapping the gate electrodes G1in the third direction DR3which is a thickness direction of the substrate SUB may be defined as channel regions. The source electrodes S1and the drain electrodes D1are regions not overlapping the gate electrodes G1in the third direction DR3and may be formed to have conductivity by doping a silicon semiconductor or an oxide semiconductor with ions or impurities.

A gate insulating layer130may be disposed on the active layers ACT1, the source electrodes S1, and the drain electrodes D1of the thin-film transistors ST1and the sensing transistors SRT. The gate insulating layer130may be an inorganic layer, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer.

The gate electrodes G1of the thin-film transistors ST1may be disposed on the gate insulating layer130. The gate electrodes G1may overlap the active layers ACT1in the third direction DR3. Each of the gate electrodes G1may be a single layer or a multilayer made of any one or more selected from molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

A first interlayer insulating layer141may be disposed on the gate electrodes G1of the thin-film transistors ST1and the sensing transistors SRT. The first interlayer insulating layer141may be an inorganic layer, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. The first interlayer insulating layer141may be composed of a plurality of inorganic layers.

Capacitor electrodes CAE may be disposed on the first interlayer insulating layer141. The capacitor electrodes CAE may overlap the gate electrodes G1of the first thin-film transistors ST1in the third direction DR3. Since the first interlayer insulating layer141has a predetermined dielectric constant, capacitors may be formed by the capacitor electrodes CAE, the gate electrodes G1, and the first interlayer insulating layer141disposed between the capacitor electrodes CAE and the gate electrodes G1. Each of the capacitor electrodes CAE may be a single layer or a multilayer made of any one or more selected from molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

A second interlayer insulating layer142may be disposed on the capacitor electrodes CAE. The second interlayer insulating layer142may be an inorganic layer, for example, a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, or an aluminum oxide layer. The second interlayer insulating layer142may be composed of a plurality of inorganic layers.

First anode connection electrodes ANDE1may be disposed on the second interlayer insulating layer142. The first anode connection electrodes ANDE1may be connected to the drain electrodes D1of the thin-film transistors ST1through first connection contact holes ANCT1penetrating the gate insulating layer130, the first interlayer insulating layer141, and the second interlayer insulating layer142. Each of the first anode connection electrodes ANDE1may be a single layer or a multilayer made of any one or more selected from molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

A first planarization layer160may be disposed on the first anode connection electrodes ANDE1to flatten steps formed by the thin-film transistors ST1. The first planarization layer160may be made of an organic layer such as acryl resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

Second anode connection electrodes ANDE2may be disposed on the first planarization layer160. The second anode connection electrodes ANDE2may be connected to the first anode connection electrodes ANDE1through second connection contact holes ANCT2penetrating the first planarization layer160. Each of the second anode connection electrodes ANDE2may be a single layer or a multilayer made of any one or more selected from molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd), copper (Cu), and alloys thereof.

A second planarization layer180may be disposed on the second anode connection electrodes ANDE2. The second planarization layer180may be made of an organic layer such as acryl resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

First electrodes (or pixel electrodes) of the light emitting units ELU1through ELU4and the light sensing units PDU may be disposed on the second planarization layer180. Each of the first through third light emitting units ELU1through ELU3includes a first electrode171, an organic light emitting layer172(b), and a common electrode173. fourth light emitting unit ELU4includes a first electrode171, an infrared light emitting layer172(a), and the common electrode173. In addition, each light sensing unit PDU includes a first electrode171, an infrared sensing layer172(c), and the common electrode173.

The first electrodes171may be connected to the second anode connection electrodes ANDE2through third connection contact holes ANCT3penetrating the second planarization layer180. The first electrodes171may be made of a metal material having high reflectivity, such as a stacked structure (Ti/Al/Ti) of aluminum and titanium, a stacked structure (ITO/Al/ITO) of aluminum and indium tin oxide, an APC alloy, or a stacked structure (ITO/APC/ITO) of an APC alloy and indium tin oxide. The APC alloy is an alloy of silver (Ag), palladium (Pd), and copper (Cu).

A pixel defining layer190may be formed on the second planarization layer180to cover all of the first electrodes171.

The pixel defining layer190is formed on the second planarization layer180to separate the first electrodes171in order to define the first through fourth light emitting units ELU1through ELU4and the light sensing units PDU. Here, the pixel defining layer190may also cover edges of the first electrodes171. The pixel defining layer190may be made of a transparent organic layer to minimize the effect on infrared light reflectance. The pixel defining layer190may be made of an organic layer such as photosensitive polyimide resin, polyamide resin, a black pixel defining layer (PDL), or polyimide resin through which infrared light is transmitted.

The organic light emitting layer172(b) may be formed on each of the first electrodes171of the first through third light emitting units ELU1through ELU3. The organic light emitting layer172(b) may include an organic material to emit light of a predetermined color. For example, the organic light emitting layer172(b) includes a hole transporting layer, an organic material layer, and an electron transporting layer.

The infrared light emitting layer172(a) may be formed on the first electrode171of fourth light emitting unit ELU4. The infrared light emitting layer172(a) may include at least one organic material selected from a low molecular weight boron-dipyrromethene derivative (BODIPY-Ph), acetone including a low molecular weight boron-dipyrromethene derivative (BODIPY-Ph), hydrocarbon (e.g., rubrene), N,N′-Di(naphthalen-1-yl)-N,N′-diphenyl-benzidine (NPB), and tris-8-hydroxyquinoline aluminum (Alq3).

The infrared sensing layer172(c) of each light sensing unit PDU is a PIN semiconductor layer. The PIN semiconductor layer may include a P-type semiconductor layer connected to the first electrode171, an N-type semiconductor layer connected to the common electrode173, and an I-type semiconductor layer disposed between the P-type semiconductor layer and the N-type semiconductor layer. In this case, the I-type semiconductor layer is depleted by the P-type semiconductor layer and the N-type semiconductor layer to generate an electric field in the I-type semiconductor layer, and holes and electrons generated by light are drifted by the electric field. Accordingly, the holes may be collected to the anode through the P-type semiconductor layer, and the electrons may be collected to the cathode through the N-type semiconductor layer.

The common electrode173may be made of a transparent conductive material (TCO) capable of transmitting light, such as indium tin oxide (ITO) or indium zinc oxide (IZO), or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag) or an alloy of Mg and Ag. When the common electrode173is made of a semi-transmissive conductive material, light output efficiency may be increased by a microcavity.

An encapsulation layer TFEL may be disposed on the common electrode173. The encapsulation layer TFEL includes at least one inorganic layer to prevent oxygen or moisture from permeating into the first through fourth light emitting units ELU1through ELU4and the light sensing units PDU. In addition, the encapsulation layer TFEL includes at least one organic layer to protect the light emitting element layer EMT from foreign substances such as dust. For example, the encapsulation layer TFEL includes a first encapsulating; inorganic layer TFE1, an encapsulating organic layer TFE2, and a second encapsulating inorganic layer TFE3.

The first encapsulating inorganic layer TFE1may be disposed on the common electrode173, the encapsulating organic layer TFE2may be disposed on the first encapsulating inorganic layer TFE1, and the second encapsulating inorganic layer TFE3may be disposed on the encapsulating organic layer TFE2. Each of the first encapsulating inorganic layer TFE1and the second encapsulating inorganic layer TFE3may be a multilayer in which one or more inorganic layers selected from a silicon nitride layer, a silicon oxynitride layer, a silicon oxide layer, a titanium oxide layer, and an aluminum oxide layer are alternately stacked. The encapsulating organic layer TFE2may be an organic layer such as acryl resin, epoxy resin, phenolic resin, polyamide resin, or polyimide resin.

A touch sensing unit TSU may be mounted and disposed on the encapsulation layer TFEL including the black matrix BM.

A black matrix BM may be formed on the one insulating layer among the first to third touch insulating layers (TINS1to TINS3) to separate areas in which the first through fourth light emitting units ELU1through ELU4and the light sensing units PDU are formed and to block light.

Since the fourth light emitting units ELU4of the infrared light emitting pixels ESP emit light in an infrared wavelength band, in an embodiment, the front surfaces (or the upper surfaces) of the fourth light emitting units ELU4are formed to be transparent. In addition, since the light sensing units PDU operate on reflected light, front surfaces (or upper surfaces) of the light sensing units PDU may also be formed to be transparent. That is, there is no need to form openings or color filters CFL4on the front surfaces of the fourth light emitting units ELU4and the light sensing units PDU.

FIG.11is a circuit diagram of a display pixel SP, an infrared light emitting pixel ESP, and a light sensing pixel LSP according to an embodiment.

Referring toFIG.11, each of the display pixel SP and the infrared light emitting pixel ESP according to the embodiment may be connected to a kthdisplay initialization wiring GILk, a kthdisplay write wiring GWLk, and a kthdisplay control wiring GCLk. In addition, each of the display pixel SP and the infrared light emitting pixel ESP may be connected to a first driving voltage wiring VDL to which a first driving voltage is supplied, a second driving voltage wiring VSL to which a second driving voltage is supplied, and a third driving voltage wiring VIL to which a third driving voltage is supplied. Alphabet letters k and n used in place of numbers below are positive integers or natural numbers excluding 0.

The display pixel SP and the infrared light emitting pixel ESP may be formed in the same circuit structure. In particular, the infrared light emitting pixel ESP may be formed in the same circuit structure as a blue display pixel SP. The circuit structure of one display pixel SP will be described below as an example.

As described above, each display pixel SP may include a light emitting unit ELU and a pixel driving unit DDU. The light emitting unit ELU may include a light emitting element LEL defined as a light emitting layer. The pixel driving unit DDU may include a driving transistor DT, switch elements, and a capacitor CST1. The switch elements include first through sixth transistors ST1through ST6.

The driving transistor DT may include a gate electrode, a first electrode, and a second electrode. The driving transistor DT controls a drain-source current Ids (hereinafter, referred to as a “driving current”) flowing between the first electrode and the second electrode according to a data voltage applied to the gate electrode. In an embodiment, the driving current Ids flowing through a channel of the driving transistor DT is proportional to the square of a difference between a voltage Vsg between the first electrode and the gate electrode of the driving transistor DT and a threshold voltage as shown in Equation 1.
Ids=kt×(Vsg−Vth)2,  (Equation 1)
where k′ is a proportional coefficient determined by the structure and physical characteristics of the driving transistor DT, Vsg is a voltage between the first electrode and the gate electrode of the driving transistor DT, and Vth is a threshold voltage of the driving transistor DT.

The light emitting element LEL emits light according to the driving current Ids. As the driving current Ids increases, the amount of light emitted from the light emitting element LEL may increase.

The light emitting element LEL may be an organic light emitting diode including an organic light emitting layer disposed between an anode and a cathode. Alternatively, the light emitting element LEL may be an inorganic light emitting element including an inorganic semiconductor disposed between an anode and a cathode. Alternatively, the light emitting element LEL may be a quantum dot light emitting element including a quantum dot light emitting layer disposed between an anode and a cathode. Alternatively, the light emitting element LEL may be a micro-light emitting element including a micro-light emitting diode disposed between an anode and a cathode.

The anode of the light emitting element LEL may be connected to a first electrode of the fourth transistor ST4and a second electrode of the sixth transistor ST6, and the cathode of the light emitting element LEL may be connected to the second driving voltage wiring VSL. A parasitic capacitance Cel may be formed between the anode and the cathode of the light emitting element LEL.

The first transistor ST1is turned on by an initialization scan signal of the kthdisplay initialization wiring GILk to connect the gate electrode of the driving transistor DT to the third driving voltage wiring VIL. Therefore, the third driving voltage of the third driving voltage wiring VIL may be applied to the gate electrode of the driving transistor DT. The first transistor ST1may have a gate electrode connected to the kthdisplay initialization wiring GILk, a first electrode connected to the gate electrode of the driving transistor DT, and a second electrode connected to the third driving voltage wiring VIL.

The second transistor ST2is turned on by a display scan signal of the kthdisplay write wiring GLk to connect the first electrode of the driving transistor DT to an nthdata wiring DL. Therefore, a data voltage of the nthdata wiring DL may be applied to the first electrode of the driving transistor DT. The second transistor ST2may have a gate electrode connected to the kthdisplay write wiring GLk, a first electrode connected to the first electrode of the driving transistor DT, and a second electrode connected to the nthdata wiring DL.

The third transistor ST3is turned on by the display scan signal of the kthdisplay write wiring GLk to connect the gate electrode and the second electrode of the driving transistor DT. When the gate electrode and the second electrode of the driving transistor DT are connected, the driving transistor DT operates as a diode. The third transistor ST3may have a gate electrode connected to the kthdisplay write wiring GLk, a first electrode connected to the second electrode of the driving transistor DT, and a second electrode connected to the gate electrode of the driving transistor DT.

The fourth transistor ST4is turned on by a display control signal of the kthdisplay control wiring ELk to connect the anode of the light emitting element LEL to the third driving voltage wiring VIL. The third driving voltage of the third driving voltage wiring VIL may be applied to the anode of the light emitting element LEL. The fourth transistor ST4has a gate electrode connected to the kthdisplay control wiring GCLk, the first electrode connected to the anode of the light emitting element LEL, and a second electrode connected to the third driving voltage wiring VIL.

The fifth transistor ST5is turned on by a control signal of a kthemission control wiring VLk to connect the first electrode of the driving transistor DT to the first driving voltage wiring VDL. The fifth transistor ST5has a gate electrode connected to the kthemission control wiring ELk, a first electrode connected to the first driving voltage wiring VDL, and a second electrode connected to the first electrode of the driving transistor DT.

The sixth transistor ST6is disposed between the second electrode of the driving transistor DT and the anode of the light emitting element LEL. The sixth transistor ST6is turned on by the emission control signal of the kthemission control wiring ELk to connect the second electrode of the driving transistor DT to the anode of the light emitting element LEL. The sixth transistor ST6has a gate electrode connected to the kthemission control wiring ELk, a first electrode connected to the second electrode of the driving transistor DT, and the second electrode connected to the anode of the light emitting element LEL.

When both the fifth transistor ST5and the sixth transistor ST6are turned on, the driving current Ids of the driving transistor DT according to the data voltage applied to the gate electrode of the driving transistor DT may flow to the light emitting element LEL.

The capacitor CST1is formed between the gate electrode of the driving transistor DT and the first driving voltage wiring VDL. A first capacitor electrode of the capacitor CST1may be connected to the gate electrode of the driving transistor DT, and a second capacitor electrode of the capacitor CST1may be connected to the first driving voltage wiring VDL.

When the first electrode of each of the first through sixth transistors ST1through ST6and the driving transistor DT is a source electrode, the second electrode may be a drain electrode. Alternatively, when the first electrode of each of the first through sixth transistors ST1through ST6and the driving transistor DT is a drain electrode, the second electrode may be a source electrode.

An active layer of each of the first through sixth transistors ST1through ST6and the driving transistor DT may be made of any one of polysilicon, amorphous silicon, and an oxide semiconductor. Although a case where the first through sixth transistors ST1through ST6and the driving transistor DT are formed as P-type metal oxide semiconductor field effect transistors (MOSFETs) has been mainly described inFIG.11, the present disclosure is not limited thereto. For example, the first through sixth transistors ST1through ST6and the driving transistor DT may also be formed as N-type MOSFETs. Alternatively, at least one of the first through sixth transistors ST1through ST6may be formed as an N-type MOSFET.

The light sensing pixel LSP according to the embodiment may be connected to an nthlight sensing scan wiring FSLn and an nthlight sensing wiring RLn.

The light sensing pixel LSP may include a light sensing unit PDU and a sensing driving unit FDU. The light sensing unit PDU may include a light sensing element PD. The sensing driving unit FDU may include a sensing transistor SRT.

The voltage of a sensing anode of the light sensing element PD may vary according to light incident on the light sensing element PD. For example, as the amount of light incident on the light sensing element PD increases, the voltage of the sensing anode of the light sensing element PD may increase.

The light sensing element PD may be a photodiode including a first electrode171, a PIN semiconductor layer, and a common electrode173. The first electrode171of the light sensing element PD may be connected to a source electrode of the sensing transistor SRT, and the common electrode173of the light sensing element PD may be connected to the second driving voltage wiring VSL. The PIN semiconductor layer of the light sensing element PD may include a P-type semiconductor layer connected to the first electrode171, an N-type semiconductor layer connected to the common electrode173, and an I-type semiconductor layer disposed between the P-type semiconductor layer and the N-type semiconductor layer. In this case, the I-type semiconductor layer is depleted by the P-type semiconductor layer (PL) and the N-type semiconductor layer (NL) to generate an electric field in the I-type semiconductor layer, and holes and electrons generated by light are drifted by the electric field. Accordingly, the holes may be collected to the first electrode171through the P-type semiconductor layer, and the electrons may be collected to the common electrode173through the N-type semiconductor layer.

The sensing transistor SRT is turned on by a sensing scan signal of the nthlight sensing scan wiring FSLn to connect the first electrode171of the light sensing element PD to the nthlight sensing wiring RLn. Therefore, the voltage of the first electrode171of the light sensing element PD may be applied to the nthlight sensing wiring RLn. The sensing transistor SRT may have a gate electrode connected to the nthlight sensing scan wiring FSLn, the source electrode connected to the sensing anode of the light sensing element PD, and a drain electrode connected to the nthlight sensing wiring RLn.

FIG.12is a waveform diagram of scan signals input to any one display pixel SP and a light sensing pixel LSP according to an embodiment.

Since a display pixel SP and an infrared light emitting pixel ESP are formed in the same circuit structure, the same scan signals supplied to the display pixel SP may also be supplied to the infrared light emitting pixel ESP.

InFIG.12, an nthemission signal EMn transmitted to the kthemission control wiring ELk during an (N−1)thframe period FN−1 and an Nthframe period FN, a kthdisplay initialization signal GIk transmitted to the kthdisplay initialization wiring GILk, an nthdisplay control signal ELn transmitted to the kthdisplay control wiring GCLk, a kthdisplay scan signal GWk transmitted to the kthdisplay write wiring GWLk, and an nthsensing scan signal FSn transmitted to the nthlight sensing scan wiring FSLn are illustrated.

The kthdisplay initialization signal Glk is a signal for controlling turning on-off of the first transistor ST1of the display pixel SP. The nthdisplay control signal ELn is a signal for controlling turning on-off of the fourth transistor ST4of the display pixel SP. The kthdisplay scan signal GWk is a signal for controlling turning on-off of the second transistor ST2and the third transistor ST3. The nthemission signal EMn is a signal for controlling turning on-off of the fifth transistor ST5and the sixth transistor ST6. The nthsensing scan signal FSn is a signal for controlling turning on-off of the sensing transistor SRT.

Each of the (N−1)thframe period FN−1 and the Nthframe period FN may include a first period t1, a second period t2, and a third period t3.

The first period t1is a period in which the gate electrode of the driving transistor DT is initialized to the third driving voltage, the second period t2is a period in which a data voltage Data(IR) or Data(R) is supplied to the gate electrode of the driving transistor DT and the threshold voltage of the driving transistor DT is sampled, and the third period t3is a period in which the light emitting element LEL emits light according to a gate voltage of the driving transistor DT. In addition, the first period t1and the third period t3are periods in which the light sensing element PD is exposed to light, and the second period t2is a period in which an anode voltage of the light sensing element PD is sensed.

The nthemission signal EMn has a first-level voltage V1during the third period t3and a second-level voltage V2during the first period t1and the second period t2. The kthdisplay scan signal GWk has the first-level voltage V1during the second period t2and the second-level voltage V2during the first period t1and the third period t3.

The kthdisplay initialization signal GIk and the nthdisplay control signal ELn have the first-level voltage V1during the first period t1and the second-level voltage V2during the second period t2and the third period t3. That is, the kthdisplay initialization signal GIk and the nthdisplay control signal ELn may be substantially the same.

The nthsensing scan signal FSn has the second-level voltage V2during the first and second periods t1and t2and the first-level voltage V1during the third period t3. The nthsensing scan signal FSn may be substantially the same as the nthemission signal EMn.

Each of the first period t1and the second period t2may be one horizontal period. One horizontal period refers to a period in which the data voltage Data(IR) or Data(R) is supplied to each of the display pixels SP disposed in one horizontal line of the display panel100. Therefore, one horizontal period may be defined as one horizontal line scan period. The display pixels SP arranged in one horizontal line may be defined as subpixels connected to one display initialization wiring, one display write wiring, one display control wiring, and one emission control wiring.

The first-level voltage V1may be a turn-on voltage that can turn on the first through sixth transistors ST1through ST6and the sensing transistor SRT. The second-level voltage V2may be a turn-off voltage that can turn off the first through sixth transistors ST1through ST6and the sensing transistor SRT. The second-level voltage V2may have a higher level than the first-level voltage V1.

The operation of the display pixel SP during the first period t1, the second period t2, and the third period t3will now be described with reference toFIGS.11and12.

First, in the first period t1, the kthdisplay initialization signal GIk having the first-level voltage V1is supplied to the kthdisplay initialization wiring GILk, and the nthdisplay control signal ELn having the first-level voltage V1is supplied to the kthdisplay control wiring GCLk.

During the first period t1, the first transistor ST1is turned on by the kthdisplay initialization signal GIk having the first-level voltage V1. Due to the turn-on of the first transistor ST1, the third driving voltage of the third driving voltage wiring VIL is applied to the gate electrode of the driving transistor DT. When the third driving voltage is applied to the gate electrode of the driving transistor DT during the first period t1, the voltage Vsg between the first electrode and the gate electrode of the driving transistor DT is greater than the threshold voltage Vth of the driving transistor DT. Accordingly, the driving transistor DT may be turned on. That is, since an on-bias can be applied to the driving transistor DT, hysteresis characteristics of the driving transistor DT can be improved.

In addition, during the first period t1, the fourth transistor ST4is turned on by the nthdisplay control signal ELn having the first-level voltage V. Therefore, due to the turn-on of the fourth transistor ST4during the first period t1, the anode of the light emitting element LEL may be initialized to the third driving voltage of the third driving voltage wiring VIL.

Second, the kthdisplay scan signal GWk having the first-level voltage V1is supplied to the kthdisplay write wiring GLk during the second period t2. Therefore, during the second period t2, each of the second transistor ST2and the third transistor ST3is turned on by the kthdisplay scan signal GWk having the first-level voltage V1.

Due to the turn-on of the third transistor ST3during the second period t2, the gate electrode and the second electrode of the driving transistor DT are connected to each other, and the driving transistor DT operates as a diode. In addition, due to the turn-on of the second transistor ST2during the second period t2, a data voltage Data (IR) or Vdata is supplied to the first electrode of the driving transistor DT. In this case, since the voltage (Vsg=Vdata−VINT) between the first electrode and the gate electrode of the driving transistor DT is smaller than the threshold voltage Vth, the driving transistor DT forms a current path until the voltage Vsg between the first electrode and the gate electrode reaches the threshold voltage Vth. Accordingly, during the second period t2, the gate electrode and the second electrode of the driving transistor DT rise to a difference voltage (Vdata−Vth) between the data voltage Vdata and the threshold voltage Vth of the driving transistor DT.

Third, the nthemission signal EMn having the first-level voltage V1is supplied to the kthemission control wiring ELk during the third period t3. During the third period t3, each of the fifth transistor ST5and the sixth transistor ST6is turned on by the nthemission signal EMn having the first-level voltage V1.

Due to the turn-on of the fifth transistor ST5, the first electrode of the driving transistor DT is connected to the first driving voltage wiring VDL. Due to the turn-on of the sixth transistor ST6, the second electrode of the driving transistor DT is connected to the anode of the light emitting element LEL.

When the fifth transistor ST5and the sixth transistor ST6are turned on, the driving current Ids flowing according to the voltage of the gate electrode of the driving transistor DT may be supplied to the light emitting element LEL. The driving current Ids may be defined as in Equation 2.
Ids=k′×{VDD−(Vdata−vth)−Vth}2(Equation 2).

In Equation 2, k′ is a proportional coefficient determined by the structure and physical characteristics of the driving transistor DT, Vth is a threshold voltage of the driving transistor DT, VDD is a first driving voltage of the first driving voltage wiring VDL, and Vdata is a data voltage. The voltage of the gate electrode of the driving transistor DT is (Vdata−Vth), and the voltage of the first electrode is VDD. Equation 2 is rearranged into Equation 3.
Ids=k′×(VDD−Vdata)2(Equation 3).

Ultimately, the driving current Ids does not depend on the threshold voltage Vth of the driving transistor DT as shown in Equation 3. That is, the threshold voltage Vth of the driving transistor DT may be compensated.

The operation of the light sensing pixel LSP during the first period t1, the second period t2, and the third period t3will now be described with reference toFIGS.11and12.

First, during the first period t1, the second-level voltage V2is supplied to the nthlight sensing scan wiring FSLn, the sensing transistor SRT is maintained in a reset state, and the light sensing element PD receives reflected light incident from the front side.

Next, during the second period t2, the second-level voltage V2is supplied to the nthlight sensing scan wiring FSLn, and the sensing transistor SRT is maintained in a turned-off state. During the second period t2, the light sensing element PD also receives reflected light incident from the front side. The voltage of the sensing anode of the light sensing element PD may rise according to light incident during the first period t1and the second period t2.

Next, the nthsensing scan signal FSn having the first-level voltage V1is supplied to the nthlight sensing scan wiring FSLn during the third period t3. The sensing transistor SRT is turned on by the nthsensing scan signal FSn having the first-level voltage V1. Due to the turn-on of the sensing transistor SRT, the sensing anode of the light sensing element PD may be connected to the nthlight sensing wiring RLn. Therefore, the component detection circuit400may sense the voltage of the sensing anode of the light sensing element PD through the nthlight sensing wiring RLn.

As illustrated inFIG.12, during at least one frame period, the main driving circuit200may supply the data voltage Data(IR) or Data(R) to display pixels or infrared light emitting pixels ESP emitting light of the same one color among the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP.

For example, the main driving circuit200may supply an infrared data voltage Data(IR) to the infrared light emitting pixels ESP during a plurality of frame periods so that the infrared light emitting pixels ESP can emit infrared light during the frame periods. Then, the main driving circuit200may supply a red data voltage Data(R) to the red first display pixels SP1during a plurality of next frame periods so that the red first display pixels SP1can emit red light during the frame periods. Accordingly, only display pixels or infrared light emitting pixels ESP emitting light of the same one color among the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP may emit light during at least one frame period.

In addition, the main driving circuit200may cause the nthsensing scan signal FSn to be supplied to the sensing driving units FDU of the light sensing pixels LSP through the light sensing scan driver120during a preset light sensing period, e.g., the third period t3of each frame period.

In other words, the main driving circuit200may supply control signals to the light sensing scan driver120in units of at least one frame period so that the light sensing scan driver120supplies the nthsensing scan signal FSn to the nthlight sensing scan wiring FSLn during a light sensing period for each horizontal line. Accordingly, light sensing signals of the light sensing pixels LSP may be output to the component detection circuit400during the preset light sensing period of each frame period.

FIG.13is a waveform diagram of scan signals input to any one display pixel SP and a light sensing pixel LSP according to an embodiment.

Referring toFIG.13, during at least one frame period, the main driving circuit200may supply a data voltage Data(IR) or Vdata to display pixels or infrared light emitting pixels ESP emitting light of the same one color among the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP. That is, the main driving circuit200may supply a corresponding data voltage to display pixels or infrared light emitting pixels ESP emitting light of the same one color among the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP so that only the display pixels or the infrared light emitting pixels ESP emitting light of the same one color emit light during at least one frame period.

Here, the main driving circuit200may cause a plurality of nthsensing scan signals FSn to be supplied to the sensing driving units FDU of the light sensing pixels LSP through the light sensing scan driver120during a preset light sensing period, e.g., a third period t3of each frame period.

In other words, the main driving circuit200causes the light sensing scan driver120to supply an nthsensing scan signal FSn, which swings to a first-level voltage V1and a second-level voltage V2, to the nthlight sensing scan wiring FSLn during a light sensing period for each horizontal line. Accordingly, light sensing signals of the light sensing pixels LSP may be output to the component detection circuit400during the preset light sensing period of each frame period in response to the n th sensing scan signal FSn which swings to the first-level voltage V1and the second-level voltage V2.

FIG.14is a waveform diagram of scan signals input to any one display pixel SP and a light sensing pixel LSP according to an embodiment.

Referring toFIG.14, the main driving circuit200may sequentially supply data voltages Data(IR) and Data(R) to the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP so that the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP sequentially emit red, green and blue light and infrared light.

For example, the main driving circuit200may supply an infrared data voltage Data(IR) to the infrared light emitting pixels ESP during a first frame period so that the infrared light emitting pixels ESP emit infrared light during the first frame period. Then, the main driving circuit200may supply a red data voltage Data(R) to the red first display pixels SP1during a second frame period so that the red first display pixels SP1emit red light during the second frame period. Accordingly, the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP may sequentially emit red, green, blue and infrared light during a plurality of frame periods.

In addition, the main driving circuit200may cause an nthsensing scan signal FSn to be supplied to the sensing driving units FDU of the light sensing pixels LSP through the light sensing scan driver120during a preset light sensing period, e.g., a third period t3of each frame period. In other words, the main driving circuit200may cause the light sensing scan driver120to supply the nthsensing scan signal FSn to the nthlight sensing scan wiring FSLn during a light sensing period for each horizontal line. Accordingly, light sensing signals of the light sensing pixels LSP may be output to the component detection circuit400during the preset light sensing period of each frame period.

FIG.15is a waveform diagram of scan signals input to any one display pixel SP and a light sensing pixel LSP according to an embodiment.

Referring toFIG.15, the main driving circuit200may sequentially supply data voltages Data(IR) and Vdata to the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP so that the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP sequentially emit red, green and blue light and infrared light. Accordingly, the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP may sequentially emit red, green, blue and infrared light during a plurality of frame periods.

Here, the main driving circuit200may cause a plurality of nthsensing scan signals FSn to be supplied to the sensing driving units FDU of the light sensing pixels LSP through the light sensing scan driver120during each frame period. In other words, the main driving circuit200causes the light sensing scan driver120to supply an nthsensing scan signal FSn, which swings to a first-level voltage V1and a second-level voltage V2, to the nthlight sensing scan wiring FSLn for each horizontal line. Accordingly, light sensing signals of the light sensing pixels LSP may be output to the component detection circuit400in response to the nthsensing scan signal FSn which swings to the first-level voltage V1and the second-level voltage V2.

FIG.16is a waveform diagram illustrating a change in luminous intensity and a change in magnitude of a light sensing signal according to an embodiment.

Referring toFIG.16, the main driving circuit200may supply a data voltage Data(v) to each of the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP by varying the magnitude of the data voltage Data(v) such that the magnitude of the data voltage Data(v) supplied to each of the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP in units of at least one frame period gradually increases or decreases in units of at least one frame.

A voltage PPG(V) of each of light sensing signals output from the light sensing pixels LSP in each light sensing period may gradually vary according to the magnitude of the data voltage Data(v) supplied to each of the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP.

FIG.17is a graph illustrating an infrared light absorption coefficient of each object from which a light sensing signal is detected.

Referring toFIG.17, the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP may sequentially emit red, green and blue light and infrared light according to data voltages Data(IR) and Data(R). In an embodiment, wavelength bands of infrared light emitted from the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP are different from each other. Therefore, the infrared light absorptance and absorption coefficient of each object may vary according to the wavelength band of infrared light emitted from each of the first through third display pixels SP1through SP3and the infrared light emitting pixels ESP.

As described above, the display device10according to the embodiment may detect light sensing signals of various wavelength bands according to different infrared wavelength bands from various objects such as palms, backs of hands, fingers, scalp, and facial skin. Biomarkers according to protein content, melanin content, collagen content, oxygen saturation, fat mass, obesity, blood pressure, blood flow, etc. may be detected from various objects such as palms, backs of hands, fingers, scalp, and facial skin.

FIG.18is a schematic block diagram of a component detection circuit400according to an embodiment.

Referring toFIG.18, the component detection circuit400according to the embodiment includes an analog-to-digital (AD) conversion output unit411(e.g., an A2D converter), a data delay unit413(e.g., a delay circuit), an arithmetic processing unit415, a comparative analysis unit416(e.g., a logic circuit), and a data output unit418(e.g., a data output circuit).

The AD conversion output unit411converts a light sensing signal from at least one light sensing pixel LSP into a digital light sensing signal.

The data delay unit413may include a storage circuit such as at least one flip-flop or a register circuit for storing, delaying and outputting a digital light sensing signal output from the AD conversion output unit411in units of at least one horizontal line or frame.

The arithmetic processing unit415performs an arithmetic operation on a digital light sensing signal output from the AD conversion output unit411and a delayed digital light sensing signal output from the data delay unit413and outputs the result value of the arithmetic operation as biometric data. The arithmetic operation may be performed in real time using a preset operation. For example, the arithmetic processing unit415performs an arithmetic operation on a digital light sensing signal output in real time from the AD conversion output unit411and a delayed digital light sensing signal output from the data delay unit413using a preset operation method such as multiplication, addition, subtraction or division or according to a preset mathematical equation and then outputs the result value of the arithmetic operation as biometric data.

The comparative analysis unit416compares the biometric data output from the arithmetic processing unit415with a preset biomarker data and detects biomarker information similar to the preset biomarker data within a preset error range. The comparison may be performed in real time. The biomarker information detected as a result of the comparison is transmitted to the data output unit418.

The data output unit418shares the biomarker information output from the comparative analysis unit416with the main driving circuit200. Here, the biomarker information may be biomarker information according to protein content, melanin content, collagen content, oxygen saturation, fat mass, obesity, blood pressure, blood flow, etc.

FIG.19is a schematic block diagram of a component detection circuit400according to an embodiment.

Referring toFIG.19, the component detection circuit400according to the embodiment includes a first AD conversion output unit410(e.g., 1stA2D converter), a second A2D conversion output unit412(e.g., 2ndA2D converter), a data storage unit414, an arithmetic processing unit415, a comparative analysis unit416, and a data output unit418.

The first AD conversion output unit410converts a first light sensing signal received from each of the light sensing pixels LSP of the first reflected light sensing area FSA1into a digital first light sensing signal and outputs the digital first light sensing signal.

The second AD conversion output unit412converts a second light sensing signal from each of the light sensing pixels LSP of the second reflected light sensing area FSA2into a digital second light sensing signal and outputs the digital second light sensing signal.

The data storage unit414stores, delays, and outputs at least one of the digital first and second light sensing signals in units of at least one horizontal line or frame. To this end, the data storage unit414may include a storage circuit such as at least one flip-flop or a register circuit.

The arithmetic processing unit415performs an arithmetic operation on a digital light sensing signal output (e.g., in real time) from the first AD conversion output unit410and at least one of the delayed first and second light sensing signals output from the data storage unit414(e.g., using a preset operation method) and outputs the result value of the arithmetic operation as biometric data. For example, the arithmetic processing unit415performs an arithmetic operation on a digital light sensing signal from the first AD conversion output unit410and at least one of the delayed first and second light sensing signals output from the data storage unit414using a preset operation method such as multiplication, addition, subtraction or division or according to a preset mathematical equation and then outputs the result value of the arithmetic operation as bio data.

The comparative analysis unit416compares the biometric data output (e.g., in real time) from the arithmetic processing unit415with preset biomarker data and detects biomarker information similar to the preset biomarker data within a preset error range. The biomarker information detected as a result of the comparison is transmitted to the data output unit418.

The data output unit418shares the biomarker information output from the comparative analysis unit416with the main driving circuit200. Here, the biomarker information may be biomarker information according to protein content, melanin content, collagen content, oxygen saturation, fat mass, obesity, blood pressure, blood flow, etc.

FIG.20is a schematic block diagram of a component detection circuit400according to an embodiment.

Referring toFIG.20, the component detection circuit400according to the embodiment may further include a biomarker matching unit420(e.g., a logic circuit), a database422, and an authentication result transmission unit424(e.g., a transmitter).

The biomarker matching unit420compares biomarker information from the data output unit418with a users' biomarker information stored in advance in the database422and extracts user information in which the biomarker information matches the users' biomarker information within a preset error range. The user's biomarker information may be stored outside the database422or in a storage device accessible to the system via a computer network.

The authentication result transmission unit424shares the user information in which the biomarker information matches the users' biomarker information with the main driving circuit200. By extracting the user information as a result of comparing the biomarker information from the data output unit418with the users' biomarker information stored in advance in the database422, it is possible to detect information about a user from which a biomarker has been detected using the display device10. In addition, the user can be authenticated using the user information.

FIG.21illustrates a method of measuring sugar content using the display device10according to the embodiment.

Referring toFIG.21, if an object (e.g., a fruit or a vegetable) is placed on a surface of the display device10, each of the infrared light emitting pixels ESP arranged in the display area DA of the display device10may receive a data voltage of a data wiring DL according to a display scan signal and an emission control signal of the display scan driver110and emit light by supplying a driving current to a light emitting element LEL according to the data voltage.

In an embodiment, each of the light sensing pixels LSP arranged in the display area DA generates a light sensing signal corresponding to the amount of reflected light incident from the front side and outputs the light sensing signal to a light sensing signal wiring ERL in response to a sensing scan signal from the light sensing scan driver120. For example, the object may be placed in front of the display device10, the emitted light may hit the object, and light reflected off a surface of the object due to the emitted light may be received by the light sensing pixels LSP. Each of the light sensing pixels LSP may sense reflected light in an infrared wavelength band incident from the front side, for example, light in a band ranging from 610 nm to 900 nm or ranging from about 610 nm to about 900 nm according to the emission wavelength band of the infrared light emitting pixels ESP and output a light sensing signal to a light sensing signal wiring ERL.

The component detection circuit400modulates the light sensing signals of the light sensing pixels LSP respectively received through the light sensing signal wirings ERL into digital light sensing signals. Then, the digital light sensing signals are analyzed using a preset component analysis algorithm or component analysis program to generate and store component detection data. For example, the component detection circuit400may analyze the water content, acidity, chromaticity, chlorophyll, hardness, etc. of fruit, vegetables, coffee beans, etc. according to magnitude values of the light sensing signals by comparing the component detection data including the magnitude values of the light sensing signals with preset comparison data. Specifically, since the absorbance and reflectance of infrared light vary according to the water content, acidity, chromaticity, chlorophyll, hardness, etc. of fruit, vegetables, coffee beans, etc., the water content, acidity, chromaticity, chlorophyll, hardness, etc. of the fruit, vegetables, coffee beans, etc. can be analyzed according to the magnitude values of the light sensing signals.

FIG.22illustrates a method of measuring a skin moisture level using the display device10according to the embodiment.

Referring toFIG.22, in a phone call state, each of the light sensing pixels LSP arranged in the display area DA generates a light sensing signal corresponding to the amount of reflected light incident from the front side and outputs the light sensing signal to a light sensing signal wiring ERL in response to a sensing scan signal from the light sensing scan driver120. Each of the light sensing pixels LSP may sense reflected light in an infrared wavelength band incident from the front side, for example, light in a band ranging from 610 nm to 900 nm or ranging from about 610 nm to about 900 nm according to the emission wavelength band of the infrared light emitting pixels ESP and output a light sensing signal to a light sensing signal wiring ERL.

The component detection circuit400modulates the light sensing signals of the light sensing pixels LSP respectively received through the light sensing wirings ERL into digital light sensing signals. Then, the digital light sensing signals are analyzed using a preset component analysis algorithm or component analysis program to generate and store biomarker information. For example, the component detection circuit400may analyze skin condition information such as skin moisture level, the amount of sebum, fat layer thickness, and the amount of melanin by comparing the biomarker information with pre-stored biomarker information. Specifically, since the absorbance and reflectance of infrared light vary according to skin conditions such as skin moisture level, the amount of sebum, fat layer thickness and the amount of melanin, the skin condition information such as the skin moisture level, the amount of sebum, fat layer thickness and the amount of melanin can be analyzed according to magnitude values of the light sensing signals.

FIG.23illustrates a scalp inspection method using the display device10according to the embodiment.

Referring toFIG.23, when the display device10is placed above the scalp, each of the light sensing pixels LSP may emit infrared light to inspect scalp conditions. Here, each of the light sensing pixels LSP may sense reflected light in an infrared wavelength band incident from the front side and output a light sensing signal to a light sensing signal wiring ERL.

The component detection circuit400generates and stores biomarker information by analyzing the light sensing signals using a preset component analysis algorithm or component analysis program. For example, the component detection circuit400may analyze scalp information such as moisture and oiliness levels of the scalp, the size of pores and the amount of sebum according to the biomarker information by comparing the biomarker information including magnitude values of the light sensing signals with preset biomarker information. Specifically, since the absorbance and reflectance of infrared light vary according to scalp conditions such as moisture and oiliness levels of the scalp, the size of pores and the amount of sebum, the scalp condition information such as the moisture and oiliness levels of the scalp, the size of pores and the amount of sebum can be analyzed according to the magnitude values of the light sensing signals.

FIGS.24and25are perspective views of a display device10according to an embodiment.

InFIGS.24and25, the display device10is illustrated as a foldable display device that is folded in the first direction DR1. The display device10may maintain both a folded state and an unfolded state. The display device10may be folded in an in-folding manner in which its front surface is disposed inside. When the display device10is bent or folded in the in-folding manner, portions of the front surface of the display device10may face each other. Alternatively, the display device10may be folded in an out-folding manner in which its front surface is disposed outside. When the display device10is bent or folded in the out-folding manner, portions of a rear surface of the display device10may face each other.

A first non-folding area NFA1may be disposed on a side, e.g., a right side of a folding area FDA. A second non-folding area NFA2may be disposed on the other side, e.g., a left side of the folding area FDA. A touch sensing unit TSU according to an embodiment of the present specification may be formed and disposed in each of the first non-folding area NFA1and the second non-folding area NFA2.

A first folding line FOL1and a second folding line FOL2may extend in the second direction DR2, and the display device10may be folded in the first direction DR1. Therefore, since a length of the display device10in the first direction DR1can be reduced to about half, a user can easily carry the display device10.

The first folding line FOL1and the second folding line FOL2may not necessarily extend in the second direction DR2. For example, the first folding line FOL1and the second folding line FOL2may extend in the first direction DR1, and the display device10may be folded in the second direction DR2. In this case, a length of the display device10in the second direction DR2may be reduced to about half. Alternatively, the first folding line FOL1and the second folding line FOL2may extend in a diagonal direction of the display device10between the first direction DR1and the second direction DR2. In this case, the display device10may be folded in a triangular shape.

When the first folding line FOL1and the second folding line FOL2extend in the second direction DR2, a length of the folding area FDA may be smaller in the first direction DR1than in the second direction DR2. In addition, a length of the first non-folding area NFA1in the first direction DR1may be greater than the length of the folding area FDA in the first direction DR1. A length of the second non-folding area NFA2in the first direction DR1may be greater than the length of the folding area FDA in the first direction DR1.

A first display area DA1may be disposed on the front surface of the display device10. The first display area DA1may overlap the folding area FDA, the first non-folding area NFA1, and the second non-folding area NFA2. Therefore, when the display device10is unfolded, an image may be displayed in a forward direction on the folding area FDA, the first non-folding area NFA1, and the second non-folding area NFA2of the display device10.

A second display area DA2may be disposed on the rear surface of the display device10. The second display area DA2may overlap the second non-folding area NFA2. Therefore, when the display device10is folded, an image may be displayed in the forward direction on the second non-folding area NFA2of the display device10.

Although a through hole TH in which a camera SDA or the like is formed is disposed in the first non-folding area NFA1inFIGS.24and25, the present disclosure is not limited thereto. The through hole TH or the camera SDA may also be disposed in the second non-folding area NFA2or the folding area FDA.

In the through hole TH, at least one infrared light emitting element emitting infrared light and at least one light sensing element (not illustrated) receiving infrared reflected light may be further formed. Accordingly, infrared light may be emitted by the at least one infrared light emitting element, and reflected light in an infrared wavelength band incident from a front side may be sensed through the at least one light sensing element.

A component detection circuit400may analyze light sensing signals using a preset component analysis algorithm or component analysis program and generate biomarker information according to magnitude values of the light sensing signals.

In display devices according to embodiments, when light emitted from red, green and blue subpixels and infrared light emitting pixels is reflected by an object such as a body part, the reflected light may be sensed using light sensing pixels of a display panel to detect optical signals. Then, the detected optical signals may be analyzed to extract various biomarkers of the object.

In addition, a display device according to an embodiments emits infrared light of different wavelength bands and extracts various biomarkers by detecting infrared optical signals of various wavelength bands. Therefore, application fields and utilization of the display devices can be further increased.

However, the effects of the present disclosure are not restricted to the one set forth herein.

In concluding the detailed description, those skilled in the art will appreciate that many variations and modifications can be made to the these embodiments without substantially departing from the principles of the present invention. Therefore, the disclosed embodiments of the invention are used in a generic and descriptive sense only and not for purposes of limitation.