Display device

A display device according to an embodiment includes a substrate including a plurality of pixels including a first pixel and a second pixel, a light emitting device layer provided on the substrate and including an anode included in each of the first pixel and the second pixel, a first bank layer in a boundary between the first pixel and the second pixel, a light emitting layer on the anode, and a cathode on the light emitting layer, an encapsulation layer provided on the light emitting device layer, and a touch sensor provided on the encapsulation layer. The cathode includes a first cathode included in the first pixel and a second cathode included in the second pixel, and the first cathode and the second cathode are separated from each other by the first bank layer.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the priority benefit of the Korean Patent Application No. 10-2016-0182401 filed on Dec. 29, 2016, which is hereby incorporated by reference as if fully set forth herein.

BACKGROUND

Field of the Invention

The present invention relates to a display device, and more particularly, to a display device including a touch sensor.

Discussion of the Related Art

Electroluminescent display devices are devices which have a structure where a light emitting layer is provided between two electrodes, and thus, emit light with an electric field between the two electrodes to display an image.

The light emitting layer may be formed of an organic material which emits light when an exciton generated by a combination of an electron and a hole is shifted from an excited state to a ground state. Alternatively, the light emitting layer may be formed of an inorganic material such as a quantum dot.

In the electroluminescent display devices, a mouse or a keyboard is generally used as an input means, but a touch sensor that enables a user to directly input information with a finger or a pen is being mainly applied to navigation devices, portable terminals, home appliances, etc.

Hereinafter, a related art electroluminescent display device including a touch sensor will be described with reference toFIG. 1.

FIG. 1is a schematic cross-sectional view of a related art electroluminescent display device.

As seen inFIG. 1, the related art electroluminescent display device includes a substrate10, a circuit device layer20, a light emitting device layer30, an encapsulation layer40, and a touch sensor50.

The circuit device layer20is formed on the substrate10. Various lines, thin film transistors (TFTs) such as a switching TFT and a driving TFT, and a capacitor are provided in the circuit device layer20.

The light emitting device layer30is formed on the circuit device layer20. The light emitting device layer30includes an anode31, a bank layer32, a light emitting layer33, and a cathode34.

The anode31is patterned and provided in each of a plurality of pixels. The bank layer32is provided in a matrix structure to define a pixel area. The light emitting layer33is formed on the anode31. The cathode34is formed on the light emitting layer33. The cathode34functions as a common electrode in the plurality of pixels, and thus, is formed all over the substrate10.

The encapsulation layer40is formed on the light emitting device layer30. The encapsulation layer40prevents external water or oxygen from penetrating into the light emitting layer33of the light emitting device layer30, thereby preventing the light emitting device layer30from being deteriorated.

The touch sensor50is formed on the encapsulation layer40. The touch sensor50includes a plurality of touch electrodes for sensing a user touch.

However, in the related art electroluminescent display device, a parasitic capacitance C is generated between each of the plurality of touch electrodes included in the touch sensor50and the cathode34included in the light emitting device layer30, and for this reason, a performance of the touch sensor50is degraded.

SUMMARY

Accordingly, the present invention is directed to provide a display device that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An aspect of the present invention is directed to provide a display device which decreases a parasitic capacitance generated between each of a plurality of touch electrodes included in a touch sensor and a cathode included in a light emitting device layer, thereby preventing a performance of the touch sensor from being degraded.

To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, there is provided a display device including a substrate including a plurality of pixels including a first pixel and a second pixel, a light emitting device layer provided on the substrate and including an anode included in each of the first pixel and the second pixel, a first bank layer in a boundary between the first pixel and the second pixel, a light emitting layer on the anode, and a cathode on the light emitting layer, an encapsulation layer provided on the light emitting device layer, and a touch sensor provided on the encapsulation layer, wherein the cathode includes a first cathode included in the first pixel and a second cathode included in the second pixel, and the first cathode and the second cathode are separated from each other by the first bank layer.

In another aspect of the present invention, there is provided a display device including a substrate, an insulation layer provided on the substrate, a light emitting device layer contacting one surface of the insulation layer, a touch sensor contacting another surface of the insulation layer, and a cathode provided in the light emitting device layer to contact a portion of the one surface of the insulation layer, wherein a distance from the cathode to the touch sensor is longer than a distance from another portion of the one surface of the insulation layer, which does not contact the cathode, to the touch sensor.

In another aspect of the present invention, there is provided a display device including a substrate including a plurality of pixels, a light emitting device layer provided on the substrate and including an anode, a bank layer, a light emitting layer, and a cathode; and a touch sensor provided on the light emitting device layer to face the cathode, wherein the cathode does not extend to a top of at least a portion of the bank layer.

DETAILED DESCRIPTION OF THE INVENTION

In describing a position relationship, for example, when a position relation between two parts is described as ‘on˜’, ‘over˜’, ‘under˜’ and ‘next˜’, one or more other parts may be disposed between the two parts unless ‘just’ or ‘direct’ is used.

FIG. 2is a schematic cross-sectional view of a display device according to an embodiment of the present invention. All the components of the display device according to all embodiments of the present invention are operatively coupled and configured.

As seen inFIG. 2, the display device according to an embodiment of the present invention may include a substrate100, a circuit device layer200, a light emitting device layer300, an encapsulation layer400, a touch sensor500, and a cover film700.

The substrate100may use glass or transparent plastic (for example, polyimide or the like) capable of being curved or bent, but is not limited thereto.

The circuit device layer200may be formed on the substrate100. The circuit device layer200may include a plurality of lines, and a thin film transistor (TFT) and a capacitor which are electrically connected to the plurality of lines. The plurality of lines may include a gate line, a data line, and a power line. The TFT may include a switching TFT, a driving TFT, and a sensing TFT. A detailed configuration of the circuit device layer200may be modified into various types well known to those skilled in the art.

The light emitting device layer300may be formed on the circuit device layer200.

The light emitting device layer300may include an anode310, a bank layer320, a light emitting layer330, and a cathode340.

The anode310may be patterned and formed in each of a plurality of pixels P1to P3on the circuit device layer200. The anode310may be formed of a reflective electrode, and thus, light emitted from the light emitting layer330may be reflected by the anode310and may be output to the outside through the cover film700. The anode310formed of the reflective electrode may include a reflective layer formed on the circuit device layer200and a transparent conductive layer formed on the reflective layer, but is not limited thereto.

The bank layer320may be formed on the circuit device layer200to cover an end of the anode310. The bank layer320may be patterned and formed in a matrix structure to define a plurality of pixel (P1to P3) areas. Therefore, the bank layer320may be formed in a boundary between the pixel (P1to P3) areas.

The light emitting layer330may be formed on the anode310. The light emitting layer330may include a red light emitting layer, a green light emitting layer, and a blue light emitting layer which are patterned and formed in the respective pixels P1to P3. The light emitting layer330may include a hole injection layer, a hole transport layer, an organic light emitting layer, an electron transport layer, and an electron injection layer, but is not limited thereto. Depending on the case, the light emitting layer330may be formed of an inorganic material such as a quantum dot or the like.

The cathode340may be formed on the light emitting layer330. The cathode340may be formed of a transparent conductive material or a semitransparent conductive material.

The cathode340may not be formed all over the substrate100but may be patterned and formed in a certain type on the substrate100. For example, the cathode340may include a first cathode340aincluded in a first pixel P1, a second cathode340bincluded in a second pixel P2, and a third cathode340cincluded in a third pixel P3.

The first cathode340a, the second cathode340b, and the third cathode340cmay be separated from each other by the bank layer320. Also, the first cathode340a, the second cathode340b, and the third cathode340cmay not be formed on a top of the bank layer320.

That is, the first cathode340a, the second cathode340b, and the third cathode340cmay not extend to the top of the bank layer320, and thus, an end of each of the first cathode340a, the second cathode340b, and the third cathode340cmay face a side surface of the bank layer320.

The same voltage may be applied to the first cathode340a, the second cathode340b, and the third cathode340c, and in this case, the first cathode340a, the second cathode340b, and the third cathode340cmay be electrically connected to each other. An electrical connection between the first cathode340a, the second cathode340b, and the third cathode340cmay be made in an edge area of the substrate100. This can be easily understood with reference toFIGS. 5 to 8to be described below.

The encapsulation layer400may be formed on the light emitting device layer300.

The encapsulation layer400prevents external water or oxygen from penetrating into the light emitting device layer300, thereby preventing the light emitting device layer300from being deteriorated. The encapsulation layer400may be formed of an insulating material.

The touch sensor500may be formed on the encapsulation layer400and may face the cathode340of the light emitting device layer300with the encapsulation layer400therebetween.

The touch sensor500may include a plurality of touch electrodes for sensing a user touch. The touch sensor500may be formed in a mutual capacitance type, but is not limited thereto. The touch sensor500may be modified into various types well known to those skilled in the art.

The cover film700may be formed on the touch sensor500. The cover film700may be formed on a surface on which an image is displayed, and prevents a scratch from occurring in a screen and protects the display device from an external impact.

According to an embodiment of the present invention, the cathode340included in the light emitting device layer300may include the first cathode340a, the second cathode340b, and the third cathode340cseparated from each other by the bank layer320and may be patterned and formed. Accordingly, according to an embodiment of the present invention, in comparison with the related art where the cathode34is formed all over the substrate10, an area of the cathode340is reduced, and thus, a parasitic capacitance C generated between each of the plurality of touch electrodes included in the touch sensor500and the cathode340is reduced.

Moreover, according to an embodiment of the present invention, since the first cathode340a, the second cathode340b, and the third cathode340cdo not extend to a top of the bank320, in comparison with the related art, a distance between the touch sensor500and the cathode340increases, and thus, a parasitic capacitance generated between each of the plurality of touch electrodes included in the touch sensor500and the cathode340is reduced.

In other words, according to an embodiment of the present invention, the light emitting device layer300may contact one surface400aof the encapsulation layer400including an insulating material, and the touch sensor500may contact another surface400bof the encapsulation layer400. In this case, the cathode340included in the light emitting device layer300may contact one portion400a1of the one surface400aof the encapsulation layer400, and another portion400a2of the one surface400aof the encapsulation layer400may contact the bank layer320of the light emitting device layer300without contacting the cathode340.

Accordingly, a distance D1from the cathode340to the touch sensor500is longer than a distance D2from the other portion400a2of the one surface400aof the encapsulation layer400to the touch sensor500, and thus, in comparison with the related art, a parasitic capacitance between the cathode340and the touch sensor500is reduced.

FIG. 3is a schematic cross-sectional view illustrating a plurality of touch electrodes501and502configuring a touch sensor500according to an embodiment of the present invention.FIG. 4is a schematic cross-sectional view illustrating a plurality of touch electrodes501and502configuring a touch sensor500according to another embodiment of the present invention.

InFIGS. 3 and 4, for convenience, the substrate100, the circuit device layer200, and the cover film700ofFIG. 2may not be illustrated, and only a light emitting device layer300, an encapsulation layer400, and a touch sensor500are illustrated. Configurations of the light emitting device layer300and the encapsulation layer400are as described above with reference toFIG. 2, and thus, their repetitive descriptions are not provided.

As seen inFIG. 3, the touch sensor500formed on the encapsulation layer400may include a first touch electrode501and a second touch electrode502which are electrically insulated from each other.

The first touch electrode501may function as a transmitting electrode that transmits a signal, and the second touch electrode502may function as a receiving electrode that receives a signal. However, the present embodiment is not limited thereto.

The first touch electrode501and the second touch electrode502may be formed of a transparent conductive material such as indium tin oxide (ITO) or the like. In this case, since an electrical conductivity of each of the first touch electrode501and the second touch electrode502is not good, an area of each of the first touch electrode501and the second touch electrode502may be enlarged, and thus, an interval between the first touch electrode501and the second touch electrode502may be narrowed. As a result, the first touch electrode501and the second touch electrode502may overlap the bank layer320, and moreover, may overlap the cathode340.

On the other hand, as seen inFIG. 4, the first touch electrode501and the second touch electrode502may be formed to overlap the bank layer320without overlapping the cathode340. In this case, the first touch electrode501and the second touch electrode502may be formed of a metal material which is good in electrical conductivity.

If the first touch electrode501and the second touch electrode502are formed to overlap the bank layer320without overlapping the cathode340as inFIG. 4, a distance between the cathode340and each of the first and second touch electrodes501and502increases in comparison withFIG. 3, and thus, a parasitic capacitance generated between the cathode340and each of the first and second touch electrodes501and502is more reduced.

FIGS. 5 to 8are schematic plan views illustrating a structure of each of a bank layer320and a cathode340according to various embodiments of the present invention.

As seen inFIG. 5(a), according to an embodiment of the present invention, the bank layer320may be overall formed in a matrix structure on a substrate100to define a plurality of pixels P1to P3. In detail, the bank layer320may include a first bank layer320aarranged in a first direction (for example, a widthwise direction) and a second bank layer320barranged in a second direction (for example, a lengthwise direction), and a plurality of pixel (P1to P3) areas may be defined by intersection of the first bank layer320aand the second bank layer320b. Therefore, the plurality of pixels P1to P3including a red pixel, a green pixel, and a blue pixel may each be provided in a tetragonal structure. Also, the red pixel, the green pixel, and the blue pixel may be continuously arranged in the widthwise direction or the lengthwise direction, and thus, a plurality of red pixels, a plurality of green pixels, and a plurality of blue pixels may each be arranged in a stripe type.

As seen inFIG. 5(b), according to an embodiment of the present invention, a cathode340may be patterned and formed on the substrate100. The cathode340may include a first cathode340a, a second cathode340b, a third cathode340c, and a connection electrode340d.

The first cathode340amay extend in the lengthwise direction to correspond to a plurality of pixels in a column where a first pixel P1is disposed, the second cathode340bmay extend in the lengthwise direction to correspond to a plurality of pixels in a column where a second pixel P2is disposed, and the third cathode340cmay extend in the lengthwise direction to correspond to a plurality of pixels in a column where a third pixel P3is disposed. For example, the first cathode340amay be formed to correspond to the plurality of red pixels arranged in a stripe type, the second cathode340bmay be formed to correspond to the plurality of green pixels arranged in a stripe type, and the third cathode340cmay be formed to correspond to the plurality of blue pixels arranged in a stripe type. In the present specification, the first to third cathodes340ato340ccorresponding to a plurality of pixels denotes that the first to third cathodes340ato340coverlap a plurality of pixels and a boundary area between the plurality of pixels.

Moreover, the connection electrode340dmay be connected to each of the first cathode340a, the second cathode340b, and the third cathode340cand may be formed in a non-display area of the substrate100. In order to be connected to the connection electrode340d, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to the non-display area of the substrate100.

The connection electrode340dmay be formed along an edge of the substrate100, and thus, when the substrate100has a tetragonal structure, the connection electrode340dmay have a tetragonal frame structure.

Since the first cathode340a, the second cathode340b, and the third cathode340care connected to each other by the connection electrode340d, the same voltage may be applied to the first cathode340a, the second cathode340b, and the third cathode340c.

The first cathode340a, the second cathode340b, the third cathode340c, and the connection electrode340dmay be formed of the same material and may be provided as one body.

The first cathode340a, the second cathode340b, and the third cathode340cmay be separated from each other with a second bank layer (320b) area therebetween, and arranged in the lengthwise direction.

Therefore, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to a top of the first bank layer320aarranged in the widthwise direction, but may not extend to a top of the second bank layer320barranged in the lengthwise direction.

As described above, since the cathode340does not extend to the top of the second bank layer320b, a total area of the cathode340is reduced in proportion thereto, and particularly, an area of the cathode340disposed relatively close to the above-described touch electrodes501and502is reduced, thereby decreasing a parasitic capacitance between each of the touch electrodes501and502and the cathode340.

Also, since the cathode340does not extend to the top of the second bank layer320b, referring toFIG. 2, a distance D1from a portion of the cathode340which does not extend to the top of the second bank layer320bto the touch sensor500is longer than a distance D2from the touch sensor500to a top of the bank layer320.

A bank layer320according to another embodiment of the present invention illustrated inFIG. 6(a)is the same as the above-described bank layer320illustrated inFIG. 5(a).

As seen inFIG. 6(b), a cathode340according to another embodiment of the present invention may include a first cathode340a, a second cathode340b, a third cathode340c, and a connection electrode340d.

The first cathode340amay extend in a widthwise direction to correspond to a plurality of pixels in one row, the second cathode340bmay extend in the widthwise direction to correspond to a plurality of pixels in another row, and the third cathode340cmay extend in the widthwise direction to correspond to a plurality of pixels in another row. Particularly, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to a non-display area of a substrate100.

Moreover, the connection electrode340dmay be connected to each of the first cathode340a, the second cathode340b, and the third cathode340cand may be formed in a tetragonal frame structure in the non-display area of the substrate100.

The first cathode340a, the second cathode340b, and the third cathode340cmay be separated from each other with a first bank layer (320a) area therebetween, and arranged in the widthwise direction. Therefore, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to a top of a second bank layer320barranged in a lengthwise direction, but may not extend to a top of the first bank layer320aarranged in the widthwise direction.

As described above, since the cathode340does not extend to the top of the first bank layer320a, a total area of the cathode340is reduced in proportion thereto, and particularly, an area of the cathode340disposed relatively close to the above-described touch electrodes501and502is reduced, thereby decreasing a parasitic capacitance between each of the touch electrodes501and502and the cathode340.

A bank layer320according to another embodiment of the present invention illustrated inFIG. 7(a)may be patterned and formed to define a pixel (P) area having a diamond structure. Therefore, the bank layer320may include a first bank layer320aarranged in a zigzag type in a lengthwise direction and a second bank layer320barranged in the zigzag type in a widthwise direction. However, the pixel P may be provided in a pentile structure in addition to the diamond structure. That is, the bank layer320may be patterned and formed to define a pixel (P) area having a pentile structure.

A cathode340according to another embodiment of the present invention illustrated inFIG. 7(b)may include a first cathode340a, a second cathode340b, a third cathode340c, and a connection electrode340d.

The first cathode340amay extend in the zigzag type in the lengthwise direction to correspond to a plurality of pixels P in one column, the second cathode340bmay extend in the zigzag type in the lengthwise direction to correspond to a plurality of pixels in another column, and the third cathode340cmay extend in the zigzag type in the lengthwise direction to correspond to a plurality of pixels in another column. Particularly, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to a non-display area of a substrate100.

Moreover, the connection electrode340dmay be connected to each of the first cathode340a, the second cathode340b, and the third cathode340cand may be formed in a tetragonal frame structure in the non-display area of the substrate100.

The first cathode340a, the second cathode340b, and the third cathode340cmay be separated from each other with a partial region of the second bank layer320btherebetween, arranged in the zigzag type in the lengthwise direction. Therefore, each of the first cathode340a, the second cathode340b, and the third cathode340cmay extend to a top of the first bank layer320aarranged in the zigzag type in the widthwise direction, but may not extend to a partial top of the second bank layer320barranged in the lengthwise direction. Particularly, the first cathode340a, the second cathode340b, and the third cathode340cmay be arranged in the zigzag type in correspondence with a plurality of pixels P having the diamond structure or the pentile structure.

As described above, since the cathode340does not extend to the partial top of the second bank layer320b, a total area of the cathode340is reduced in proportion thereto, and particularly, an area of the cathode340disposed relatively close to the above-described touch electrodes501and502is reduced, thereby decreasing a parasitic capacitance between each of the touch electrodes501and502and the cathode340.

A bank layer320according to another embodiment of the present invention illustrated inFIG. 8(a)is the same as the above-described bank layer320illustrated inFIG. 7(a).

A cathode340according to another embodiment of the present invention illustrated inFIG. 8(b)may be arranged in a zigzag type in a widthwise direction. The cathode340may extend to a non-display area of a substrate100.

Since the cathode340does not extend to a partial top of a first bank layer320aarranged in the zigzag type in the widthwise direction, a total area of the cathode340is reduced in proportion thereto, and particularly, an area of the cathode340disposed relatively close to the above-described touch electrodes501and502is reduced, thereby decreasing a parasitic capacitance between each of the touch electrodes501and502and the cathode340.

As described above, according to various embodiments of the present invention, since the cathode340does not extend to a top of at least a portion of the bank layer320, the parasitic capacitance between each of the touch electrodes501and502and the cathode340is reduced in comparison with the related art where the cathode340extends to a whole top of the bank layer320.

Hereinabove,FIGS. 5 to 8illustrate a structure of each of the bank layer320and the cathode340according to various embodiments of the present invention, but the bank layer320and the cathode340according to various embodiments of the present invention are not limited to the structure.

FIG. 9is a schematic cross-sectional view of a display device according to another embodiment of the present invention.

In the above-described display device according to an embodiment of the present invention illustrated inFIG. 2, since the touch sensor500is formed on a bottom of the cover film700on which an image is displayed, external light may be reflected by the touch electrodes501and502included in the touch sensor500, causing degradation in image quality. In order to solve a problem where the external light is reflected by the touch electrodes501and502, in the display device illustrated inFIG. 2, a polarizing film may be additionally provided between the touch sensor500and the cover film700.

If the polarizing film is additionally provided, light reflected by the touch electrodes501and502included in the touch sensor500cannot pass through the polarizing film, thereby solving a problem where the external light is reflected. In this case, however, since the polarizing film is additionally provided, a luminance of the display device is reduced. That is, in a case where light emitted from the light emitting layer330of the light emitting device layer300passes through the polarizing film, a considerable amount of light can be blocked by the polarizing film.

FIG. 9relates to a display device for preventing external light from being reflected by the touch electrodes501and502included in the touch sensor500and solving a problem where luminance is reduced.

As seen inFIG. 9, the display device according to another embodiment of the present invention may include a substrate100, a circuit device layer200, a light emitting device layer300, an encapsulation layer400, a touch sensor500, a color filter layer600, and a cover film700.

The substrate100and the circuit device layer200are the same as the above-described embodiment, and thus, their repetitive descriptions are not provided.

The light emitting device layer300may include an anode310, a bank layer320, a light emitting layer330, and a cathode340.

The anode310and the bank layer320are the same as the above-described embodiment, and thus, their repetitive descriptions are not provided.

The light emitting layer330may be formed on the anode310. The light emitting layer330may be provided to emit white light, and in this case, the light emitting layer330may be formed all over a top of the substrate100without being patterned or formed in each of a plurality of pixels. Therefore, the light emitting layer330may be formed on the bank layer320provided in a boundary between adjacent pixel areas. Since the display device according to another embodiment of the present invention includes the color filter layer600, the white light emitted from the light emitting layer330may pass through the color filter layer600, and thus, colored light may be emitted from each pixel.

The light emitting layer330emitting the white light may include a stack including a blue light emitting layer and a stack including a yellow light emitting layer, or may include a stack including a red light emitting layer, a stack including a green light emitting layer, and the stack including the blue light emitting layer. A configuration of the light emitting layer330may be modified into various types well known to those skilled in the art.

The cathode340, the encapsulation layer400, and the touch sensor500are as described above, and thus, their repetitive descriptions are not provided.

The color filter layer600may be formed on the touch sensor500. The color filter layer600may include a black matrix610, a color filter620, and an overcoat layer630.

The black matrix610may be formed in a boundary between adjacent pixels to divide an area of an individual color filter620provided in each pixel, thereby preventing light leakage from occurring in the boundary between the adjacent pixels. The black matrix610may be formed to overlap the bank layer320.

The black matrix610may be provided in plurality, and the color filter620may be formed between adjacent black matrixes610. The color filter620may include a red (R) color filter, a green (G) color filter, and a blue (B) color filter which are provided in respective pixels.

The overcoat layer630may be formed on the color filter620to planarize a surface of the substrate100.

The cover film700may be formed on the color filter layer600.

The cover film700may be directly adhered to the overcoat layer630of the color filter layer600. In this case, since a separate transparent adhesive layer for adhering the cover film700cannot be used, a process is simplified, and the material cost is reduced.

According to another embodiment of the present invention, since the color filter layer600is disposed closer to a light emitting surface (i.e., the cover film700) than the light emitting device layer300, light emitted from the light emitting device layer300may be changed to colored light by passing through the color filter layer600, and thus, it is possible to implement a color display device.

Particularly, according to another embodiment of the present invention, since the color filter layer600may be disposed closer to the light emitting surface (i.e., the cover film700) than the touch sensor500. That is, the touch sensor500may be provided between the color filter layer600and the light emitting device layer300. Therefore, external light being reflected by the touch electrodes501and502configuring the touch sensor500can be blocked by the color filter layer600. Accordingly, a separate anti-reflection layer such as a polarizing film may not be provided for decreasing reflection of the external light by the touch electrodes501and502configuring the touch sensor500, thereby solving a problem where luminance is reduced by the separate anti-reflection layer.

FIGS. 10A to 10Cillustrate a method of forming a light emitting device layer300in the above-described display device ofFIG. 9, according to an embodiment of the present invention and particularly, illustrates a method of pattern-forming an cathode340on a light emitting layer330.

First, as seen inFIG. 10A, a bank layer320may be patterned and formed on an anode310, and a light emitting layer330may be formed on the anode310and the bank layer320.

The light emitting layer330may include a hole transport layer (HTL), an organic light emitting layer (EML), and an electron transport layer (ETL) which are sequentially stacked. In this case, the ETL may include a photochromic material.

Subsequently, as seen inFIG. 10B, ultraviolet (UV) may be irradiated onto a certain region of the light emitting layer330. The certain region onto which the UV is irradiated may be a region where a below-described cathode340is formed. Therefore, the UV may be irradiated onto a region of the light emitting layer330, which does not overlap the bank layer320, without being irradiated onto another region of the light emitting layer330overlapping the bank layer320.

In this case, a phase change of the photochromic material in the ETL occurs in the region onto which the UV is irradiated, and the phase change of the photochromic material does not occur in the other region onto which the UV is not irradiated.

Subsequently, as seen inFIG. 10C, the cathode340may be deposited on the light emitting layer330.

The cathode340may be deposited without a separate mask. In this case, the cathode340may be formed in a region where the phase change of the photochromic material occurs due to the irradiation of the UV, and the cathode340may not be formed in a region where the phase change of the photochromic material does not occur.

For example, the cathode340may be deposited by a nucleation action in the region where the phase change of the photochromic material occurs, but the cathode340may not be deposited by a desorption action in the region where the phase change of the photochromic material does not occur.

In this manner, by using the nucleation action and the desorption action of the photochromic material based on the presence of UV irradiation, the cathode340may be patterned and formed in only a desired region without a separate mask.

As described above, if the photochromic material is included in an upper layer (for example, the ETL) of the light emitting layer330contacting the cathode340, the cathode340may be patterned and formed without a separate mask process.

As described above, according to the embodiments of the present invention, since the cathode including the first and second cathodes separated from each other by the bank layer is patterned and formed, in comparison with the related art where the cathode is formed all over the substrate, an area of the cathode is reduced, and thus, a parasitic capacitance generated between each of the plurality of touch electrodes included in the touch sensor and the cathode is reduced, thereby preventing a performance of the touch sensor from being reduced.

Moreover, according to the embodiments of the present invention, since the cathode does not extend to the top of the bank layer, in comparison with the related art, a distance between the touch sensor and the cathode increases, and thus, a parasitic capacitance generated between each of the plurality of touch electrodes included in the touch sensor and the cathode is reduced, thereby preventing a performance of the touch sensor from being degraded.