DISPLAY DEVICE

A display device is provided, which includes a light sensor in a display panel. The display device comprises a substrate having a unit pixel area and a unit light sensor area, a first electrode over the substrate, a second electrode over the first electrode, a third electrode over the second electrode, a light emitting layer in the unit pixel area and disposed between the first electrode and the second electrode, and a light active layer disposed in the unit light sensor area and disposed between the second electrode and the third electrode.

BACKGROUND

Technical Field

The present disclosure relates to a display device comprising a light sensor.

Description of the Related Art

A display device includes various display elements such as a liquid crystal display element or an organic light emitting element in a display area. Since a light sensor is embedded in the display device, a method capable of applying a variety of applications by interconnecting the display area with the light sensor has been devised.

In the display device, a hole may be formed to mount the light sensor, and the light sensor may be disposed in the hole. In this case, since an image is not displayed in an area where the hole is formed, the image displayed in the display device may be disconnected and recognized by a user. Also, since the image is not displayed as much as the area in which the hole is formed, a size of the display area in the display device may be reduced.

In addition, a side of the hole in the display device may be exposed to external water, oxygen, etc. For this reason, a reliability problem such as degradation of the light emitting element may occur in the display device.

Also, the light sensor used in the display device is an inorganic light sensor, and has problems in that it is expensive and lightweight and occupies a large space due to a large volume.

BRIEF SUMMARY

The present disclosure has been made in view of the above problems, and it is a technical benefit of the present disclosure to provide a display device that may reduce or minimize the decrease of a size of a display area caused by a light sensor.

It is another technical benefit of the present disclosure to provide a display device that may include a light sensor in a display panel.

In addition to the technical benefits of the present disclosure as mentioned above, additional technical benefits and features of the present disclosure will be clearly understood by those skilled in the art from the following description of the present disclosure.

In accordance with an aspect of the present disclosure, the above and other technical benefits can be accomplished by the provision of a display device comprising a substrate having a unit pixel area and a unit light sensor area, a first electrode over the substrate, a second electrode over the first electrode, a third electrode over the second electrode, a light emitting layer in the unit pixel area and disposed between the first electrode and the second electrode, and a light active layer disposed in the unit light sensor area between the second electrode and the third electrode.

In accordance with another aspect of the present disclosure, the above and other technical benefits can be accomplished by the provision of a display device comprising a substrate having a plurality of unit pixel areas and a plurality of unit light sensor areas, a plurality of light emitting elements disposed in the plurality of unit pixel areas, and including a first anode electrode, a light emitting layer, and a first cathode electrode, and a plurality of organic light emitting elements disposed in the plurality of unit light sensor areas, and including a second anode electrode, a light active layer, and a second cathode electrode, wherein the first cathode electrode of the plurality of light emitting elements and the second cathode electrode of the plurality of organic light emitting elements are provided on the same layer.

DETAILED DESCRIPTION

In describing a position relationship, for example, when the position relationship is described as ‘upon˜,’ ‘above˜,’ ‘below˜,’ and ‘next to˜,’ one or more portions may be arranged between two other portions unless ‘just’ or ‘direct’ is used.

In describing elements of the present disclosure, the terms “first,” “second,” etc., may be used. These terms are intended to identify the corresponding elements from the other elements, and basis, order, or number of the corresponding elements are not limited by these terms. The expression that an element is “connected” or “coupled” to another element should be understood that the element may directly be connected or coupled to another element but may directly be connected or coupled to another element unless specifically mentioned, or a third element may be interposed between the corresponding elements.

Hereinafter, an example of a transparent display device according to the present disclosure will be described in detail with reference to the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

FIG.1is a schematic plan view illustrating a display device according to one embodiment of the present disclosure, andFIG.2is a schematic exploded view illustrating a display device according to one embodiment of the present disclosure.

Referring toFIGS.1and2, a display device10according to one embodiment of the present disclosure may include a display panel100, a circuit board200, a cover window300, and a frame400.

Although the display panel100is described as being implemented as an organic light emitting display device, it may also be implemented as a liquid crystal display device, a plasma display panel (PDP), a quantum dot light emitting display (QLED) device, or an electrophoretic display device.

The display panel100may include a display area DA in which pixels are formed, and a bezel area BA disposed near the display area DA. The display area DA may display an image, and may include a first display area DA1and a second display area DA2.

The bezel area BA may not display an image, and may be disposed to surround the display area DA. The bezel area BA may include a driver for supplying various signals to a plurality of signal lines in the display area DA, and a link portion for connecting the driver with the plurality of signal lines. The driver may include a gate driver for supplying a gate signal to a gate line, and a data driver for supplying a data signal to a data line.

The circuit board200may be disposed over a rear surface of the display panel100. The circuit board200may be a printed circuit board (PCB) or a flexible printed circuit board (FPCB).

The cover window300may be disposed over a front surface of the display panel100. The cover window300may protect the display panel100from external impact by covering the front surface of the display panel100.

The cover window300may be made of a transparent plastic material, a glass material, or a reinforced glass material. As an example, the cover window300may have any one of a sapphire glass and a gorilla glass or a stacked structure thereof. As another example, the cover window300may include any one material of polyethyleneterephthalate (PET), polycarbonate (PC), polyethersulfone (PES), polyethylenapthanate (PEN), and polynorbornene (PNB). The cover window300may be made of reinforced glass in consideration of scratch and transparency.

The frame400may accommodate the display panel100and support the cover window300. The frame400may include an accommodating portion capable of accommodating the circuit board200. The frame400allows the display panel100and the circuit board200to be fixed to the display device10. The frame400may serve to protect the display panel100and the circuit board200from impact. The frame400may be a middle frame or a housing, but is not limited thereto.

Hereinafter, the elements provided in the display area DA of the display panel100will be described in more detail.

FIG.3is a view illustrating an example of a pixel provided in a first display area ofFIG.1,FIG.4is a cross-sectional view taken along line I-I′ ofFIG.3,FIG.5is a view illustrating an example of a pixel and a light sensor, which are provided in a second display area ofFIG.1,FIG.6is a cross-sectional view taken along line II-IP ofFIG.5,FIG.7is a view illustrating a modified example ofFIG.6, andFIG.8is a view illustrating a modified example ofFIG.5.

The first display area DA1may include a plurality of unit pixel areas UPA as shown inFIG.3. In the first display area DA1, the plurality of unit pixel areas UPA may be disposed to be adjacent to each other.

As shown inFIG.5, the second display area DA2may include a plurality of unit pixel areas UPA, which are the same as those of the first display area DA1, and may further include a plurality of unit light sensor areas USA. The second display area DA2may have an aperture ratio lower than that of the first display area DA1as a unit light sensor area USA is provided between the plurality of unit pixel areas UPA. The second display area DA2may have luminance lower than that of the first display area DA1.

Each of the plurality of unit light sensor areas USA may include at least one light sensor LS. The light sensor LS senses external light by absorbing light incident from the outside. In this case, the light incident from the outside may be light of infrared ray (IR) irradiated toward a target and reflected from the target. The sensing area SA may correspond to an area for sensing light in the light sensor LS.

In one embodiment, the unit light sensor area USA may be provided with the same number of light sensors LS as the number of subpixels SP1, SP2, SP3and SP4provided in the unit pixel area UPA. For example, when four subpixels SP1, SP2, SP3and SP4are provided in the unit pixel area UPA, four light sensors LS may be provided in the unit light sensor area USA, but the present disclosure is not limited thereto.

In another embodiment, the unit light sensor area USA may be provided with one light sensor LS as shown inFIG.8. In this case, the unit light sensor area USA may have the same size as that of the unit pixel area UPA, but is not limited thereto.

Each of the plurality of unit pixel areas UPA may be provided with one pixel P. The pixel P emits predetermined or selected light to display an image. A light emission area EA may correspond to an area that emits light in the pixel P.

The pixel P may include a first subpixel SP1, a second subpixel SP2, and a third subpixel SP3. The first subpixel SP1may emit red light, the second subpixel SP2may emit green light, and the third subpixel SP3may emit blue light, but the present disclosure is not limited thereto. The pixel P may further include a fourth subpixel SP4that emits white light. The arrangement order of the plurality of subpixels SP1, SP2, SP3and SP4is not limited to those shown inFIGS.3and5, but may be changed in various ways. It is to be noted that, althoughFIGS.3,5and8have shown examples of the arrangement and size of the unit light sensor area USA and the unit pixel area UPA, the present disclosure is not limited thereto. For example, the fourth subpixel SP4that emits white light may be omitted, and the unit light sensor area USA may have a same size as one subpixel and thus replace the position of the fourth subpixel SP4.

Each of the first subpixel SP1, the second subpixel SP2, the third subpixel SP3, and the fourth subpixel SP4may be provided with a circuit element, which includes a capacitor, a thin film transistor, etc., and a light emitting element. The thin film transistor may include a switching transistor, a sensing transistor, and a driving transistor T.

The switching transistor is switched in accordance with a scan signal supplied to a scan line to supply a data voltage supplied from the data line to the driving transistor T.

The sensing transistor serves to sense a deviation in a threshold voltage of the driving transistor T, which causes deterioration of image quality.

The driving transistor T is switched in accordance with the data voltage supplied from the switching transistor to generate a data current from a power source supplied from a pixel power line and supply the data current to a first anode electrode122of the subpixels SP1, SP2, SP3and SP4. The driving transistor T includes an active layer ACT, a gate electrode GE, a source electrode SE and a drain electrode DE.

In detail, a light shielding layer LS may be provided over a first substrate111. The light shielding layer LS may serve to shield external light incident on the active layer ACT of the driving transistor T. The light shielding layer LS may be formed of a single layer or multi-layer made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu), or their alloy.

A buffer film BF may be provided over the light shielding layer LS. The buffer film BF is intended to protect the transistors T from water permeated through the first substrate vulnerable to moisture permeation, and may be formed of an inorganic layer, for example, a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multi-layer of SiOx and SiNx.

The active layer ACT may be provided over the buffer film BF. The active layer ACT may be formed of a silicon-based semiconductor material or an oxide-based semiconductor material.

A gate insulating layer GI may be provided over the active layer ACT. The gate insulating layer GI may be formed of an inorganic layer, for example, a silicon oxide layer (SiOx), a silicon nitride layer (SiNx), or a multi-layer of SiOx and SiNx.

The gate electrode GE may be provided over the gate insulating layer GI. The gate electrode GE may be formed of a single layer or multi-layer made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu), or their alloy.

The source electrode SE and the drain electrode DE may be provided over the interlayer dielectric layer ILD. One of the source electrode SE and the drain electrode DE may be connected to the active layer ACT through a first contact hole CH1that passes through the gate insulating layer GI and the interlayer dielectric layer ILD.

The source electrode SE and the drain electrode DE may be formed of a single layer or multi-layer made of any one of molybdenum (Mo), aluminum (Al), chromium (Cr), gold (Au), titanium (Ti), nickel (Ni), neodymium (Nd) and copper (Cu), or their alloy.

A planarization layer PLN may be provided over the source electrode SE and the drain electrode DE to planarize a step difference due to the driving transistor T. The planarization layer PLN may be formed of an organic layer such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, and a polyimide resin.

A plurality of organic light emitting diodes OLED and a plurality of organic photo diodes OPD may be provided over the planarization layer PLN.

As shown inFIG.4, the first display area DA1may be provided with only a plurality of organic light emitting diodes OLED over the planarization layer PLN. On the other hand, as shown inFIG.6, the second display area DA2may be provided with a plurality of organic light emitting diodes OLED and a plurality of organic photo diodes OPD on the planarization layer PLN. For convenience of description, the following description will be based on the second display area DA2. The description of the organic light emitting diodes OLED of the second display area DA2may also be applied to the organic light emitting diodes OLED of the first display area DA1.

In order to implement the plurality of organic light emitting diodes OLED and the plurality of organic photo diodes OPD, the display panel100according to one embodiment of the present disclosure may include a first electrode120provided over the planarization layer PLN. The first electrode120may include a first anode electrode122provided in the unit pixel area UPA and a first dummy anode electrode124provided in the unit light sensor area USA.

The first anode electrode122may be provided in the unit pixel area UPA, and may be provided for each of the subpixels SP1, SP2, SP3and SP4on the planarization layer PLN. The first anode electrode122may be connected to the driving transistor T. In detail, the first anode electrode122may be connected to the source electrode SE or the drain electrode DE of the driving transistor T through a second contact hole CH2that passes through the planarization layer PLN. Therefore, the first anode electrode122may be electrically connected to the driving transistor T. The first anode electrode122may be an anode electrode of the organic light emitting diode OLED.

The first dummy anode electrode124may be provided in the unit light sensor area USA, and may be provided for each of the light sensors LS over the planarization layer PLN. The first dummy anode electrode124may be disposed on the same layer as the first anode electrode122, and may be spaced apart from the first anode electrode122. The first dummy anode electrode124may be formed to be patterned on the same layer as the first anode electrode122in substantially the same shape as that of the first anode electrode122, but does not correspond to the configuration of the organic photo diode OPD. That is, the first dummy anode electrode124is formed together with the first anode electrode122while forming the first anode electrode122without changing the existing mask, and does not belong to the organic photo diode OPD. Therefore, the first dummy anode electrode124may be omitted as shown inFIG.7.

The first electrode120that includes the first anode electrode122and the first dummy anode electrode124may be formed of a metal material having high reflectance, such as a stacked structure (Ti/Al/Ti) of aluminum and titanium, a stacked structure (ITO/Al/ITO) of aluminum and ITO, an Ag alloy, a stacked structure (ITO/Ag alloy/ITO) of Ag alloy and ITO, a MoTi alloy, and a stacked structure (ITO/MoTi alloy/ITO) of MoTi alloy and ITO. The Ag alloy may be an alloy of silver (Ag), palladium (Pd), copper (Cu), etc. The MoTi alloy may be an alloy of molybdenum (Mo) and titanium (Ti).

The bank125may be provided between the plurality of subpixels SP1, SP2, SP3and SP4over the planarization layer PLN. At this time, the bank125may be formed to cover or at least partially cover the edge of the first anode electrode122of each of the plurality of subpixels SP1, SP2, SP3and SP4and expose a portion of the first anode electrode122. Therefore, the bank125may prevent a problem in which light emitting efficiency is deteriorated due to concentration of current on an end of the first anode electrode122.

The bank125may abut light emission areas EA1, EA2and EA3of the subpixels SP1, SP2, SP3and SP4. The light emission areas EA1, EA2and EA3of each of the sub-pixels SP1, SP2, SP3and SP4represent an area in which the first anode electrode122, a light emitting layer130and a first cathode electrode142are sequentially stacked and holes from the first anode electrode122and electrons from the first cathode electrode142are combined with each other in the light emitting layer130to emit light. In this case, the area in which the bank125is not provided and the first anode electrode122is exposed may become the light emission area EA, and the other area may become a non-light emission area NEA.

Meanwhile, the bank125may be provided between the plurality of light sensors LS. At this time, the bank125may be formed to cover or at least partially cover the edge of the first dummy anode electrode124of each of the plurality of light sensors LS and expose a portion of the first dummy anode electrode124.

The bank125may be formed of an organic layer such as an acrylic resin, an epoxy resin, a phenolic resin, a polyamide resin, and a polyimide resin.

The display panel100according to one embodiment of the present disclosure may include a first common layer CL1provided over the first electrode120. The first common layer CL1may include a hole transporting layer. In one embodiment, the first common layer CL1may further include at least one of a hole injection layer or an electron blocking layer.

The hole injection layer serves to smoothly inject holes from the first electrode120, particularly from the first anode electrode122into the light emitting layer130. The hole transporting layer serves to smoothly transfer the holes to the light emitting layer130. The electron blocking layer serves to prevent electrons injected into the light emitting layer130from being transferred to the hole transporting layer.

The first common layer CL1may also be provided in the unit light sensor area USA as well as the unit pixel area UPA. That is, the first common layer CL1may be provided over the first anode electrode122and the first dummy anode electrode124. The first common layer CL1may be a common layer commonly provided in the plurality of subpixels SP1, SP2, SP3and SP4and the light sensor LS.

The display panel100according to one embodiment of the present disclosure may include a second common layer CL2provided over the first common layer CL1. The second common layer CL2may include an electron transporting layer. In one embodiment, the second common layer CL2may further include a hole blocking layer.

The electron transporting layer serves to smoothly transfer electrons injected from the second electrode140, particularly the first cathode electrode142to the light emitting layer130. The hole blocking layer serves to prevent holes injected into the light emitting layer130from being transferred to the electron transporting layer.

The second common layer CL2may also be provided in the unit light sensor area USA as well as the unit pixel area UPA. That is, the second common layer CL2may be provided over the light emitting layer130in the unit pixel area UPA, and may be provided over the first common layer CL1in the unit light sensor area USA. The second common layer CL2may be a common layer commonly provided in the plurality of subpixels SP1, SP2, SP3and SP4and the light sensor LS.

The display panel100according to one embodiment of the present disclosure may include a light emitting layer130provided between the first common layer CL1and the second common layer CL2. When holes and electrons are transferred to the light emitting layer130through the hole transporting layer and the electron transporting layer, respectively, the holes and the electrons may be combined with each other in the light emitting layer130to emit light.

The light emitting layer130may be provided for each of the subpixels SP1, SP2, SP3and SP4. For example, a red light emitting layer for emitting red light may be provided in the first subpixel SP1, a green light emitting layer for emitting green light may be provided in the second subpixel SP2, and a blue light emitting layer for emitting blue light may be provided in the third subpixel SP3. The fourth subpixel SP4may include, but is not limited to, a white light emitting layer for emitting white light.

The light emitting layer130is provided in the subpixels SP1, SP2, SP3and SP4of the unit pixel area UPA, and the first common layer CL1and the second common layer CL2may be spaced apart from each other with the light emitting layer130interposed therebetween in the unit pixel area UPA. Meanwhile, the light emitting layer130may not be provided in the unit light sensor area USA. Therefore, the first common layer CL1and the second common layer CL2may be in contact with each other in the entire unit light sensor area USA. Therefore, each of the subpixels SP1, SP2, SP3and SP4of the unit pixel area UPA includes light emission areas EA1, EA2and EA3emitting a predetermined or selected color, whereas the unit light sensor area USA may not include a light emission area.

The display panel100according to one embodiment of the present disclosure may include a second electrode140provided over the second common layer CL2. The second electrode140may include a first cathode electrode142provided in the unit pixel area UPA and a second cathode electrode144provided in the unit light sensor area USA.

The first cathode electrode142may be provided in the unit pixel area UPA, and may be commonly provided in the subpixels SP1, SP2, SP3and SP4. The first cathode electrode142may be a cathode electrode of the organic light emitting diode OLED.

The second cathode electrode144is provided in the unit light sensor area USA, and may be commonly provided in the light sensors LS. The second cathode electrode144may be a cathode electrode of the organic photo diode OPD.

The second cathode electrode144may be provided over the same layer as the first cathode electrode142, and may be connected to the first cathode electrode142. For example, the first cathode electrode142and the second cathode electrode144may be integrally formed.

The second electrode140that includes the first cathode electrode142and the second cathode electrode144may be formed of a transparent conductive material (TCO) such as ITO and IZO, which may transmit light, or a semi-transmissive conductive material such as magnesium (Mg), silver (Ag) or an alloy of magnesium (Mg) and silver (Ag). When the second electrode140is formed of a semi-transmissive metal material, light output efficiency may be increased by a micro cavity in the plurality of subpixels SP1, SP2, SP3and SP4.

The display panel100according to one embodiment of the present disclosure may include a third common layer CL3provided over the second electrode140. The third common layer CL3may include a hole transporting layer. In one embodiment, the third common layer CL3may further include at least one of a hole injection layer or an electron blocking layer.

The hole injection layer serves to smoothly inject the holes from a light active layer160into the second electrode140, particularly the second cathode electrode144. The hole transporting layer serves to smoothly transfer the holes injected from the light active layer160to the second electrode140, particularly the second cathode electrode144. The electron blocking layer serves to prevent electrons from being transferred to the hole transporting layer.

Each of the hole injection layer, the hole transporting layer, and the electron blocking layer of the third common layer CL3may have a material different from that of each of the hole injection layer, the hole transporting layer, and the electron blocking layer of the first common layer CL1, but is not limited thereto. The material of each of the hole injection layer, the hole transporting layer, and the electron blocking layer of the third common layer CL3may be selected in consideration of the material of the light active layer160. In some cases, each of the hole injection layer, the hole transporting layer, and the electron blocking layer of the third common layer CL3may be formed of the same material as that of each of the hole injection layer, the hole transporting layer, and the electron blocking layer of the first common layer CL1.

The third common layer CL3may also be provided in the unit light sensor area USA as well as the unit pixel area UPA. That is, the third common layer CL3may be provided over the first cathode electrode142of the unit pixel area UPA and the second cathode electrode144of the unit light sensor area USA. The third common layer CL3may be a common layer commonly provided in the plurality of subpixels SP1, SP2, SP3and SP4and the light sensor LS.

The display panel100according to one embodiment of the present disclosure may include a fourth common layer CL4provided over the third common layer CL3. The fourth common layer CL4may include an electron transporting layer. In one embodiment, the fourth common layer CL4may further include a hole blocking layer.

The electron transporting layer serves to smoothly transfer electrons to a second anode electrode154. The hole blocking layer serves to prevent the holes from being transferred to the electron transporting layer.

Each of the electron transporting layer and the hole blocking layer of the fourth common layer CL4may have a material different from that of each of the electron transporting layer and the hole blocking layer of the second common layer CL2, but is not limited thereto. The material of each of the electron transporting layer and the hole blocking layer of the fourth common layer CL4may be selected in consideration of the material of the light active layer160. In some cases, each of the electron transporting layer and the hole blocking layer of the fourth common layer CL4may be formed of the same material as that of each of the electron transporting layer and the hole blocking layer of the second common layer CL2.

The fourth common layer CL4may also be provided in the unit light sensor area USA as well as the unit pixel area UPA. That is, the fourth common layer CL4may be provided over the third common layer CL3in the unit pixel area UPA, and may be provided over the light active layer160in the unit light sensor area USA. The fourth common layer CL4may be a common layer commonly provided in the plurality of subpixels SP1, SP2, SP3and SP4and the light sensor LS.

The display panel100according to one embodiment of the present disclosure may include a light active layer160provided between the third common layer CL3and the fourth common layer CL4. The light active layer160may absorb light incident from the outside. At this time, the light incident from the outside may be light of infrared ray (IR) irradiated toward a target and reflected from the target. The light active layer160absorbs light and thus is changed from a ground state to an excited state, and may separate the electrons from the holes. The electrons are transferred to the second cathode electrode144through the third common layer CL3, and the holes may be transferred to the second anode electrode154through the fourth common layer CL4. Therefore, a potential difference is generated between the second cathode electrode144and the second anode electrode154, and a current may flow.

The light active layer160may be made of a material having a Perovskite structure. The Perovskite structure has an ABX3structure, wherein A may include an organic cation such as Methylammonium (MA) and Formamidium (FA), or an inorganic cation such as Cs, and B may include one of Pb, Sn, and Ge. X may include a halide based material.

The light active layer160may be provided in the light sensor LS. In one embodiment, the light active layer160may be formed to be patterned in each of the light sensors LS, as shown inFIG.6, but is not limited thereto. In another embodiment, the light active layer160may be formed in one pattern in a plurality of adjacent light sensors LS.

The light active layer160is provided in the light sensors LS of the unit light sensor area USA, and the third common layer CL3and the fourth common layer CL4may be spaced apart from each other with the light active layer160interposed therebetween in the unit light sensor area USA. Meanwhile, the light active layer160may not be provided in the subpixels SP1, SP2, SP3and SP4of the unit pixel area UPA. Therefore, the third common layer CL3and the fourth common layer CL4may be in contact with each other in the entire unit pixel area UPA. Therefore, the light sensors LS of the unit light sensor area USA may include a sensing area SA for sensing the light incident from the outside, whereas the unit pixel area UPA may not include a sensing area. That is, the sensing area SA may be provided in the unit light sensor area USA, and the light emission area EA may be provided in the unit pixel area UPA. In addition, the sensing area SA and the light emission area EA may not overlap each other.

The display panel100according to one embodiment of the present disclosure may include a third electrode150provided over the fourth common layer CL4. The third electrode150may include a second dummy anode electrode152provided in the unit pixel area UPA and a second anode electrode154provided in the unit light sensor area USA.

The second anode electrode154is provided in the unit light sensor area USA, and may be commonly provided in the light sensors LS. The second anode electrode154may be an anode electrode of the organic photo diode OPD.

The second dummy anode electrode152may be provided in the unit pixel area UPA, and may be commonly provided in the plurality of subpixels SP1, SP2, SP3and SP4. The second dummy anode electrode152may be provided on the same layer as the second anode electrode154, and may be connected to the second anode electrode154. For example, the second dummy anode electrode152and the second anode electrode154may be integrally formed.

The second dummy anode electrode152may be formed on the same layer as the second anode electrode154simultaneously with the second anode electrode154, but does not correspond to the configuration of the organic light emitting diode OLED. That is, the second dummy anode electrode152is formed together with the second anode electrode154without changing the existing mask, and does not belong to the organic light emitting diode OLED. Therefore, the second dummy anode electrode152may be omitted.

The third electrode150that includes the second dummy anode electrode152and the second anode electrode154may be formed of a transparent conductive material (TCO) such as ITO or IZO, which may transmit light, so as to transfer external light to the light active layer160.

An encapsulation layer170may be provided over the organic light emitting diodes OLED and the organic photo diode OPD. The encapsulation layer170may be provided over the third electrode150to cover or at least partially cover the third electrode150. The encapsulation layer170serves to prevent oxygen or water from being permeated into the organic light emitting diodes OLED and the organic photo diodes OPD. To this end, the encapsulation layer170may include at least one inorganic layer and at least one organic layer.

Although not shown inFIGS.4and6, a capping layer may be additionally provided between the third electrode150and the encapsulation layer170.

The first substrate111and the second substrate112, in which the encapsulation layer170is provided, may be bonded to each other by a separate adhesive layer180. The adhesive layer180may be an optically clear resin layer (OCR) or an optically clear adhesive film (OCA).

The display panel100according to one embodiment of the present disclosure includes a light sensor LS therein. In more detail, the display panel100according to one embodiment of the present disclosure may include a plurality of organic light emitting diodes OLED for emitting light and a plurality of organic photo diodes OPD for absorbing external light, on the planarization layer PLN.

Each of the plurality of organic light emitting diodes OLED may include a first anode electrode122, a first common layer CL1, a light emitting layer130, a second common layer CL2, and a first cathode electrode142. In each of the plurality of organic light emitting diodes OLED, holes from the first anode electrode122and electrons from the first cathode electrode142may be combined with each other in the light emitting layer130to emit light of a predetermined or selected color.

Each of the plurality of organic photo diodes OPD may include a second cathode electrode144, a third common layer CL3, a light active layer160, a fourth common layer CL4, and a second anode electrode154. In addition, in each of the plurality of organic photo diodes OPD, electrons and holes separated from each other by the light active layer160that absorbs external light may be transferred to the second cathode electrode144and the second anode electrode154to flow a current, and light may be measured based on the current.

At this time, each of the first common layer CL1, the second common layer CL2, the third common layer CL3and the fourth common layer CL4may be a common layer commonly provided in the plurality of organic light emitting diodes OLED and the plurality of organic photo diodes OPD. In addition, the first cathode electrode142of the organic light emitting diode OLED and the second cathode electrode144of the organic photo diode OPD may be simultaneously formed on the same layer.

In the display panel100according to one embodiment of the present disclosure, the organic photo diodes OPD may be formed together with the organic light emitting diodes OED through a process of forming the organic light emitting diodes OLED. That is, in the display panel100according to one embodiment of the present disclosure, a separate process is not added to form the light sensor LS therein, and therefore, process complexity is not increased.

Also, in the display panel100according to one embodiment of the present disclosure, the organic photo diode OPD of the light sensor LS does not overlap the organic light emitting diodes OLED, and is not disposed below the organic light emitting diodes OLED. Therefore, in the display panel100according to one embodiment of the present disclosure, since light emitted from the organic light emitting diode OLED may not be incident on the organic photo diode OPD, interference light due to the organic light emitting diode OLED may not be generated.

In addition, in the display panel100according to one embodiment of the present disclosure, as the light sensor LS is formed therein, a separate hole for seating the light sensor LS may not be formed. In the display panel100according to one embodiment of the present disclosure, a hole passing through the display panel100is not formed, whereby external water, oxygen, etc., may be prevented from being permeated into the side of the hole. Therefore, the display panel100according to one embodiment of the present disclosure may prevent the organic light emitting diode OLED from being degraded, and may improve reliability.

In addition, in the display panel110according to one embodiment of the present disclosure, since a hole is not formed, an image may not be disconnected. Further, the display panel100according to one embodiment of the present disclosure may include a unit pixel area UPA provided with pixels P between the unit light sensor areas USA provided with the light sensors LS. Therefore, in the display panel100according to one embodiment of the present disclosure, an image may be displayed by the pixels P even in an area in which the light sensors LS are disposed.

The display panel100according to one embodiment of the present disclosure may include a second display area DA2instead of a notch area in which an image is not displayed, wherein the second display area DA2is provided with light sensors LS and pixels P to sense light and at the same time display an image. Therefore, the display panel100according to one embodiment of the present disclosure may prevent the area, in which an image is displayed, from being reduced by the light sensors LS.

Also, in the display panel100according to one embodiment of the present disclosure, an organic light sensor LS including an organic photo diode OPD may be applied instead of an inorganic semiconductor light sensor. Therefore, the display panel100according to one embodiment of the present disclosure may reduce costs, and may reduce weight.

FIG.9is a schematic plan view illustrating a display device according to another embodiment of the present disclosure, andFIG.10is a view illustrating an example of a light sensor provided in a light sensor area and a pixel provided in a display area ofFIG.9.

Referring toFIGS.9and10, the display panel100according to another embodiment of the present disclosure may be divided into a display area DA and a bezel area BA disposed near the display area DA.

The display area DA includes a plurality of unit pixel areas UPA, and each of the plurality of unit pixel areas UPA may include a plurality of subpixels SP1, SP2, SP3and SP4provided with an organic light emitting diode OLED. Since each of the plurality of subpixels SP1, SP2, SP3and SP4is substantially the same as the organic light emitting diode OLED of the plurality of subpixels SP1, SP2, SP3and SP4shown inFIGS.3to8, its detailed description will be omitted.

The bezel area BA may not display an image, and may be disposed to surround the display area DA.

In the display panel100according to another embodiment of the present disclosure, the light sensor area LSA is provided between the display area DA and the bezel area BA. The light sensor area LSA includes a plurality of unit light sensor areas USA, and each of the plurality of unit light sensor areas USA may include at least one light sensor LS provided with an organic photo diode OPD. Since the organic photo diode OPD of the at least one light sensor LS is substantially the same as the organic photo diode OPD of the light sensor LS shown inFIGS.3to8, its detailed description will be omitted.

The light sensor area LSA may be disposed to surround the display area DA between the display area DA and the bezel area BA as shown inFIG.9. As shown inFIG.10, one or two unit light sensor areas USA may be disposed between the display area DA and the bezel area BA in the light sensor area LSA.

As described above, in the display panel100according to another embodiment of the present disclosure, the light sensor area LSA is disposed to surround the outside of the display area DA, whereby a notch area that is recessed from one side of the display area DA and recognized by a user may be removed. In addition, in the display panel100according to another embodiment of the present disclosure, the entire display area DA may have the same resolution and luminance. Therefore, the display panel100according to another embodiment of the present disclosure may prevent a portion of the display area DA from being visible to a user due to a difference in resolution and luminance as compared with the display panel100shown inFIGS.1to8.

In addition, in the display panel100according to another embodiment of the present disclosure, only one or two unit light sensor areas USA may be disposed between the display area DA and the bezel area BA, whereby a size of the display area DA may not be significantly reduced.

FIG.11is a schematic plan view illustrating a display device according to other embodiment of the present disclosure,FIG.12is a view illustrating an example of a pixel and a light sensor, which are provided in a bezel area ofFIG.11, andFIG.13is a cross-sectional view taken along line III-III′ ofFIG.12.

Referring toFIGS.11to13, the display panel100according to other embodiment of the present disclosure is different from the display panel100shown inFIGS.1to10in that the light sensor area LSA is disposed in the bezel area BA. Hereinafter, the differences fromFIGS.1to10will be described in detail, and a redundant description will be omitted.

In the display panel100according to other embodiment of the present disclosure, the light sensor area LSA may be disposed in the bezel area BA, particularly an area in which a plurality of dummy pixels are provided. The display panel100may include a plurality of dummy pixels DP provided in the bezel area BA. The plurality of dummy pixels DP has the same configuration as that of the pixel P although the light emitting layer130does not emit light, and may be disposed in a position adjacent to the display area DA in the bezel area BA.

The display panel100according to other embodiment of the present disclosure may be provided such that the plurality of light sensors LS of the light sensor area LSA overlap the plurality of dummy pixels DP. In detail, each of the plurality of dummy pixels DP may be provided in the bezel area BA over the first substrate111. Each of the plurality of dummy pixels DP may be formed in such a manner that a first anode electrode122, a first common layer CL1, a light emitting layer130, a second common layer CL2and a first cathode electrode142are sequentially stacked over the first substrate111. The first anode electrode122may not be connected to the driving transistor T, unlike the pixels P of the display area DA. Since the first anode electrode122is not connected to the driving transistor T, the plurality of dummy pixels DP may not emit light even though the light emitting layer130is provided. InFIG.13, the plurality of dummy pixels DP are shown as including the light emitting layer130, but is not limited thereto. The light emitting layer130may be omitted from the plurality of dummy pixels DP.

The plurality of light sensors LS may be provided over the plurality of dummy pixels DP in the bezel area BA. Each of the plurality of light sensors LS may be formed in such a manner that a second cathode electrode144, a third common layer CL3, a light active layer160, a fourth common layer CL4, and a second anode electrode154are sequentially stacked on the plurality of dummy pixels DP. The second cathode electrode144may be the same as the first cathode electrode142of the dummy pixel DP. That is, the plurality of light sensors LS and the plurality of dummy pixels DP may share the cathode electrode.

In the display panel100according to other embodiment of the present disclosure, the plurality of light sensors LS are disposed in the bezel area BA, whereby the light sensor area LSA may be formed without reducing the size of the display area DA.

Also, in the display panel100according to other embodiment of the present disclosure, the plurality of light sensors LS may be disposed to overlap the plurality of dummy pixels DP that are previously provided, whereby the light sensor area LSA may be formed without increasing the size of the bezel area BA.

According to the present disclosure, the following advantageous effects may be obtained.

In the present disclosure, as the light sensor is provided in the display panel, a separate hole for seating the light sensor may not be formed. Therefore, in the present disclosure, since external water, oxygen, etc., are not permeated into the side of the hole, the light emitting element may be prevented from being degraded, and reliability may be improved.

Also, in the present disclosure, the organic light sensor made of an organic photo diode may be applied instead of the inorganic semiconductor light sensor, whereby costs may be reduced, and weight may be reduced.

In addition, in the present disclosure, the notch area in which an image is not displayed may be removed, whereby the area in which the light sensors are disposed may not be recognized by a user. Furthermore, in the present disclosure, decrease of the size in the area, in which the image is displayed, by the light sensor may be minimized or reduced.