Liquid crystal display

A liquid crystal display according to an exemplary embodiment of the present disclosure includes: a first substrate including a plurality of unit regions positioned at a display area in a plan view; a liquid crystal layer opposing the first substrate; a unit electrode portion positioned on a first surface of the first substrate at one unit region; a lower dam positioned at a peripheral area positioned around the display area in the plan view; and a protrusion positioned corresponding to the unit region in the plan view. The lower dam and protrusion are positioned between the first substrate and the liquid crystal layer and protruded toward the liquid crystal layer. The protrusion enclosing a portion around the unit region with respect to a center of the unit region in the plan view. The lower dam and the protrusion are positioned at a same layer and include the same material.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean Patent Application No. 10-2015-0115557 filed in the Korean Intellectual Property Office on Aug. 17, 2015, the entire contents of which are incorporated herein by reference.

BACKGROUND

(a) Technical Field

The present disclosure relates to a display device. More particularly, the present disclosure relates to a vertical alignment (VA) mode liquid crystal display.

(b) Description of the Related Art

A display device, such as a liquid crystal display (LCD) and an organic light diode display, generally includes a display panel including a plurality of pixels as a unit displaying an image.

The display panel of a liquid crystal display generally includes a liquid crystal layer of liquid crystal molecules, a field generating electrode configured to control the alignment of the liquid crystal molecules of the liquid crystal layer, a plurality of signal lines configured to apply a voltage to at least a portion of the field generating electrode, and a plurality of switching element connected thereto. When a voltage is applied to the field generating electrode, an electric field is generated in the liquid crystal layer such that the liquid crystal molecules are rearranged, thereby controlling the amount of light transmitted by the liquid crystal layer to display an image. To control the amount of the transmitted light, the display panel may include at least one polarizer.

The field generating electrode included in the liquid crystal display includes a pixel electrode applied with a data voltage and an opposed electrode applied with a common voltage. The pixel electrode may be applied with the data voltage through a switching element, which may be a thin film transistor. The pixel electrode and the opposed electrode may be positioned on opposite sides of the liquid crystal layer, or may be positioned on the same side with respect to the liquid crystal layer.

The liquid crystal display may have a vertical alignment (VA) mode in which long axes of the liquid crystal molecules are aligned almost vertical to the surface of the display panel in the absence of an electric field to the liquid crystal layer. The liquid crystal display of the vertical alignment (VA) mode may easily realize a large contrast ratio and a wide reference viewing angle compared with other modes.

In the vertical alignment (VA) mode liquid crystal display, to realize the wide viewing angle, a plurality of sub-regions or domains having different alignment directions of the liquid crystal molecules may be formed in one pixel. As one example of forming the plurality of domains in one pixel, there is a method of forming cutouts of minute slits in the field generating electrodes. If the cutouts are formed in the field generating electrode, a fringe field is generated at an edge of the cutout, thereby rearranging the liquid crystal molecules to form the plurality of domains by.

The liquid crystal display has a structure in which a plurality of layers are deposited, and an exposure process using a photomask is used to form a pattern of each layer.

To define an initial alignment of the liquid crystal molecules of the liquid crystal display, an alignment layer is positioned on an inner surface opposing the liquid crystal layer among surfaces of the display panel. For example, the alignment layer may be formed by coating the alignment layer on the inner surface of the display panel. However, control of the alignment layer at the edge thereof is not easy because the aligning agent may spread in a plan view. If the edge of the region where the alignment layer is formed is not controlled, a sealant adhering two panels including the display panel may contact the alignment layer, or a region where the alignment layer is not coated may be generated on the display area displaying the image. If the alignment layer contacts the sealant, adherence of the sealant is weak, absorption is generated such that reliability is decreased, and resistance of an electrical short point may be increased between two panels. When the alignment layer is not coated on the edge portion of the display area, the initial alignment of the liquid crystal molecules is not defined such that a display defect is generated. These problems may be prevented if a margin of the region where the alignment layer is formed is increased such that a distance between the display area and the sealant is far and a non-display area of the edge of the display device may be widened.

SUMMARY

The present system and method increase a liquid crystal alignment control force and transmittance of a liquid crystal display. Further, the formation region of the alignment layer is controlled by controlling the spread of the aligning agent in the formation process of the alignment layer, and a manufacturing process is simplified by reducing a number of photomasks used in the manufacturing process of the liquid crystal display to reduce the manufacture cost and the manufacture time.

A liquid crystal display according to an exemplary embodiment of the present disclosure includes: a first substrate including a plurality of unit regions positioned in a display area in a plan view; a liquid crystal layer opposing the first substrate and including a plurality of liquid crystal molecules; a unit electrode portion positioned on a first surface toward the liquid crystal layer among surfaces of the first substrate and positioned at one unit region; at least one lower dam positioned at a peripheral area that is positioned around the display area in the plan view, positioned between the first substrate and the liquid crystal layer, and protruded toward the liquid crystal layer; and a protrusion positioned corresponding to the unit region in the plan view, positioned between the first substrate and the liquid crystal layer, and protruded toward the liquid crystal layer, wherein the protrusion includes a portion enclosing at least a portion around the unit region with respect to a center of the one unit region in a plan view, and the lower dam and the protrusion are positioned at a same layer and include the same material.

The protrusion may include a first lateral surface obliquely inclined with respect to a bottom surface of the protrusion in a cross-sectional view, and the liquid crystal molecules positioned around the first lateral surface may be pretilted with respect to a normal direction of a surface of the first substrate.

The lower dam may include a first dam adjacent to the display area in the plan view and a second dam positioned between the first dam and an edge of the first substrate.

A first alignment layer positioned between the lower dam and the protrusion, and the liquid crystal layer, may be further included.

A spacer that is positioned at a same layer as the protrusion and the lower dam, includes a same material as the protrusion and the lower dam, and has a top surface that is higher than a top surface of the protrusion and the lower dam may be further included.

The protrusion, the lower dam, and the spacer may include a light blocking material.

A main light blocking portion having a top surface that is lower than the top surface of the spacer may be further included, and the main light blocking portion may be positioned at a same layer as the protrusion, the lower dam, and the spacer and include a same material as the protrusion, the lower dam, and the spacer.

A second substrate opposing the first substrate with the liquid crystal layer interposed therebetween; a sealant positioned between the first substrate and the second substrate and positioned in the peripheral area in the plan view; and at least one upper dam positioned in the peripheral area in the plan view, positioned between the second substrate and the liquid crystal layer, and protruded toward the liquid crystal layer may be further included.

A second alignment layer positioned between the upper dam and the liquid crystal layer may be further included.

A spacer that is positioned at a same layer as the upper dam, includes a same material as the upper dam, and has a top surface that is higher than a top surface of the upper dam may be further included.

A spacer that is positioned at a same layer as the protrusion and the lower dam, includes a same material as the protrusion and the lower dam, and has a top surface that is higher than a top surface of the protrusion and the lower dam, may be further included.

The protrusion may include a pair of transverse portions opposing each other with respect to the center of the unit electrode portion and respectively including a side parallel to the first direction, and a pair of longitudinal portions opposing each other with respect to the center of the unit electrode portion and respectively including a side parallel to a second direction crossing the first direction.

The protrusion may further include at least one corner portion including a first oblique side that is parallel to a direction that is oblique with respect to the first direction and the second direction in the plan view.

The cross-sectional lateral surface of the corner portion may form an angle of about 1 degree to about 2 degrees with a bottom surface of the protrusion.

The unit region may include a plurality of sub-regions in which the liquid crystal molecules are inclined in different directions from each other when an electric field is generated in the liquid crystal layer, the unit electrode portion may include a stem portion positioned at a boundary between adjacent sub-regions and a plurality of branch portions connected to the stem portion, and the branch portion may extend in a different direction from the first direction and the second direction.

The unit electrode portion may include at least one flat portion respectively positioned at at least one corner of the unit electrode portion.

The first substrate may have a curved surface.

A manufacturing method of a liquid crystal display according to an exemplary embodiment of the present disclosure includes: forming a plurality of thin film layers on a substrate; coating and exposing a photosensitive material on the plurality of thin film layers by using a photomask; and processing the exposed photosensitive material to form a protrusion positioned corresponding to one unit region of a display area and at least one lower dam positioned at a peripheral area around the display area, wherein the protrusion includes a portion enclosing along at least a portion around the unit region with respect to a center of the unit region in a plan view.

The photomask may include a first region corresponding to the protrusion, a second region corresponding to the lower dam, and a third region, and at least one light transmittance of the first region and the second region may be different from light transmittance of the third region.

The photomask may further include a fourth region having different light transmittance from the first region, the second region, and the third region, and in the step of forming the protrusion and the lower dam, a spacer corresponding to the fourth region may also be formed.

In the display device according to an exemplary embodiment of the present disclosure, the liquid crystal alignment control force and the transmittance may be increased. Further, the alignment layer formation region may be controlled by controlling the spread of the aligning agent in the formation process of the alignment layer, and the manufacturing cost and the manufacturing cost may be reduced, thereby simplifying the manufacturing process by reducing a number of photomasks used in the manufacturing process of the liquid crystal display.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. Like reference numerals designate like elements throughout the specification. When an element such as a layer, film, region, or substrate is referred to as being “on” another element, it may be directly on the other element, or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

To clarify the present system and method, parts that are not germane to the description are omitted, and the same elements or equivalents are referred to with the same reference numerals throughout the specification.

First, a liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 1toFIG. 4.

Referring toFIG. 1, a liquid crystal display according to an exemplary embodiment of the present disclosure includes a display panel300. In a view of a plane, the display panel300includes a display area DA where a plurality of pixels PX are arranged and a peripheral area PA positioned outside and surrounding the display area DA. Here, the view of the plane is to be observed on a position where the image displayed by the display panel300can be seen. Compared with this, a cross-section view is to see a cross-section of several layers configuring the display panel300. This may be equally applied to the following description.

The plurality of pixels PX may be arranged in an approximate matrix shape but is not limited thereto.

The pixel PX as a region of the display panel300displaying the image for one image signal may display the image of a primary color such as red, green, and blue. The display of the various colors may be realized by controlling the luminance of the plurality of pixels PX representing the different colors.

One pixel PX may include at least one light transmission region where the light is relatively more transmitted and at least one light blocking region where the light is relatively less transmitted or completely blocked.

A plurality of signal lines connected to the pixel PX are positioned in the display area DA, and a portion of the signal lines may extend to the peripheral area PA.

The signal lines include a plurality of gate lines GL1-GLn transmitting a gate signal that turns on/off the switching element and a plurality of data lines DL1-DLm transmitting the data voltage. The gate lines GL1-GLn extend in a first direction D1in the plan view, and the data lines DL1-DLm extend in a second direction D2that is different from the first direction D1. The second direction D2may be perpendicular to the first direction D1.

The display panel300may include at least one switching element positioned at the region corresponding to one pixel PX and at least one pixel electrode connected thereto. The switching element may include at least one thin film transistor connected to at least one data line DLj (j=1, 2, . . . , m) and at least one gate line GLi (i=1, 2, . . . , n). The thin film transistor is controlled depending on the gate signal transmitted by the gate line GLi such that the data voltage transmitted by the data line DLj may be transmitted to the pixel electrode.

The peripheral area PA may be included in the portion of the non-display area of the display panel300. A plurality of driving circuits (not shown) configured to drive the pixel PX may be positioned in the peripheral area PA.

As shown inFIG. 1, at least one dam of DAM1, DAM2, DAM3, and DAM4is positioned in the peripheral area PA.FIG. 1shows dams DAM1, DAM2, DAM3, and DAM4positioned at different distances from the display area DA; however the number of dams is not limited thereto, and one of the dams DAM1and DAM2may be omitted, and one of the dams DAM3and DAM4may be omitted.

The dams DAM1and DAM3are adjacent to the display area DA and extend along the periphery of the display area DA. The dams DAM1and DAM3include a portion enclosing most of the periphery of the display area DA, thereby forming a closed line; however it is not limited thereto, and one portion thereof may be opened, and they may be divided into a plurality of portions.

The dams DAM2and DAM4are positioned between the dams DAM1and DAM3and the edge of the display panel300. The dams DAM2and DAM4include a portion enclosing most of the periphery of the dams DAM1and DAM3to be a closed line; however it is not limited thereto, and one portion thereof may be opened, and they may be divided into a plurality of portions.

Other dams (not shown) may be further positioned between the dams DAM1and DAM3, and the dams DAM2and DAM4, or in the peripheral area PA outside the dams DAM2and DAM4.

Referring toFIG. 2, in the cross-section of the display panel300, the display panel300includes a lower panel and an upper panel opposing each other and a liquid crystal layer3positioned therebetween. The lower panel includes a lower substrate110, the upper panel includes an upper substrate210, and the liquid crystal layer3includes a plurality of liquid crystal molecules.

A sealant310is positioned between the lower panel and the upper panel. The sealant310combines the lower panel and the upper panel to be fixed and seals the liquid crystal layer3. The sealant310is formed along an edge circumference of the lower substrate110and the upper substrate210, and particularly may be positioned adjacent to the edge of one substrate (e.g., the upper substrate210). The sealant310may include a conductive ball (not shown) having a conductivity.

The liquid crystal molecules may be initially aligned to be approximately perpendicular to the surfaces of the substrates110and210. For this, alignment layers11and21are positioned on at least one inner surface of the upper panel and the lower panel, and the alignment layers11and21may be vertical alignment layers. The alignment layer11is positioned on the inner surface of the lower panel opposing the liquid crystal layer3, and the alignment layer21is positioned on the inner surface of the upper panel opposing the liquid crystal layer3.

The alignment layers11and21may include a portion covering most of the display area DA, and may include a portion positioned in the peripheral area PA.

The alignment layers11and21may be formed by an inkjet printing method. An aligning agent may be dripped on the lower substrate110or the upper substrate210from a nozzle of an inkjet head, and the dripped ink may be dried to form the alignment layers11and21. The aligning agent may include an alignment layer material such as a polyimide (PI) and a solvent.

The dams DAM1, DAM2, DAM3, and DAM4prevent the alignment layer from being spread into the peripheral area PA in the formation process of the alignment layers11and21, the dams DAM1and DAM3adjacent to the display area DA firstly prevent the aligning agent from being spread into the peripheral area PA, and the dams DAM2and DAM4prevent the spread of the aligning agent that be flowed over the dams DAM1and DAM3. The outermost dams DAM2and DAM4may define a spread margin of the aligning agent.

Among the described dams DAM1, DAM2, DAM3, and DAM4, the first dam DAM1and the second dam DAM2are positioned on the inner surface of the lower substrate110, thereby being referred to as lower dams, and the third dam DAM3and the fourth dam DAM4are positioned on the inner surface of the upper substrate210, thereby being referred to as upper dams. The first dam DAM1and the third dam DAM3may be aligned with each other in the vertical direction in a cross-sectional view, but they are not limited thereto, and they may be arranged to be alternately disposed. Likewise, the second dam DAM2and the fourth dams DAM4may be aligned with each other in the vertical direction in a cross-sectional view, but they are not limited thereto, and they may be arranged to be alternately disposed.

The outermost dams DAM2and DAM4among the dams DAM1, DAM2, DAM3, and DAM4may overlap the sealant310. The aligning agent spread into the peripheral area PA overlaps most of the region where the sealant310is formed such that the dams DAM2and DAM4may be positioned at the approximate center of the width of the sealant310or may be positioned to be close to the display area DA to prevent the sealing force of the sealant310from being weakened.

The vertical heights H2and H3or the thickness of the plurality of dams DAM1, DAM2, DAM3, and DAM4in the cross-sectional view positioned on one substrate110and210may be the same as each other or different from each other.

The display area DA is described again.

Referring toFIG. 3andFIG. 4, one pixel PX includes at least one unit region SP. Particularly, when one pixel PX includes a plurality of unit regions SP, the areas of the unit regions SP may be the same or different.

When one pixel PX includes the plurality of unit regions SP, the unit regions SP included in one pixel PX may be disposed in a square matrix shape as shown inFIG. 3.FIG. 3shows an example in which one pixel PX includes six unit regions SP arranged in the 3×2 matrix shape; however, an exemplary embodiment of the present disclosure is not limited thereto.

The plurality of unit regions SP included in one pixel PX, as shown inFIG. 4, may be disposed to be divided into two regions that are divided by a thin film transistor region TRA where the thin film transistor is positioned. For example, the plurality of unit regions SP arranged in a 2×2 matrix shape may be positioned above the thin film transistor region TRA, and the plurality of unit regions SP arranged in the 3×2 matrix shape may be positioned below the thin film transistor region TRA.

The thin film transistor region TRA may correspond to a light blocking region that transmits little or no light. Most of the unit region SP is the light transmission region.

One pixel PX of the liquid crystal display according to an exemplary embodiment of the present disclosure may include a plurality of subpixels PXa and PXb that may display the image of the luminance depending on gamma curves that are the same or different for one image signal. Referring toFIG. 4, the first subpixel PXa included in one pixel PX may include the plurality of unit regions SP positioned at one side of the thin film transistor region TRA, and the second subpixel PXb may include the plurality of unit regions SP positioned at the other side of the thin film transistor region TRA. When the second subpixel PXb displays the image of the lower luminance than the first subpixel PXa in the middle gray, a number of unit regions SP included in the second subpixel PXb may be greater than a number of unit regions SP included in the first subpixel PXa.

Next, the detailed structure of the unit region SP of the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 5andFIG. 6as well as the above-described drawings.

Referring toFIG. 5, one unit region SP includes a plurality of sub-regions A1, A2, A3, and A4in the plan view. The liquid crystal molecules31included in the different sub-regions A1, A2, A3, and A4are arranged such that the long axes of the liquid crystal molecules31in each sub-region are inclined in different directions when an electric field is generated in the liquid crystal layer. The long axes of the liquid crystal molecules31are initially aligned in the direction perpendicular to the surface of the display panel300, and then the liquid crystal molecules31are rearranged to be inclined in the direction parallel to the surface of the display panel300when the electric field is generated in the liquid crystal layer3.

For example, as shown inFIG. 5, when a unit region SP includes four sub-regions A1, A2, A3, and A4, the liquid crystal molecules31positioned in the different sub-regions A1, A2, A3, and A4are inclined in the different directions a1, a2, a3, and a4. The directions a1, a2, a3, and a4in which the liquid crystal molecules31are mainly inclined are different from the first direction D1and the second direction D2. For example, the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31in the sub-regions A1, A2, A3, and A4may form an angle of about 40 degrees to about 50 degree or about 130 degrees to about 140 degrees with respect to the first direction D1or the second direction D2; however the present disclosure is not limited thereto. The main inclination direction a1of the liquid crystal molecules31in the first sub-region A1is opposite to the main inclination direction A3of the liquid crystal molecules31in the third sub-region A3, and the main inclination direction a2of the liquid crystal molecules31in the second sub-region A2is opposite to the main inclination direction a4of the liquid crystal molecules31in the fourth sub-region A4. The vector components of the first direction D1or the second direction D2of the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31of two sub-regions of A1, A2, A3, and A4adjacent each other in the first direction D1or the second direction D2may be opposite to each other.

Most parts of the sub-regions A1, A2, A3, and A4form the light transmission region in which the light is transmitted.

Referring toFIG. 5andFIG. 6, one unit region SP includes a protrusion261to control the arrangement direction of the liquid crystal molecules31. The protrusion261may be included in the lower panel, in which case, the protrusion261is positioned between the lower substrate110and the liquid crystal layer. The alignment layer11is positioned on the protrusion261.

The protrusion261, as shown inFIG. 6, is protruded toward the liquid crystal layer in the cross-sectional view to provide a pretilt to the liquid crystal molecules31, thereby controlling the inclination direction of the liquid crystal molecules31. The position of the protrusion261in the cross-sectional view is not limited thereto, and the protrusion261may be positioned in other layers of which the surface adjacent to the liquid crystal layer may be protruded toward the liquid crystal layer.

Referring toFIG. 5, the protrusion261is formed along at least a portion around one unit region SP in the plan view.

In detail, the protrusion261includes, in the plan view, a pair of transverse portions261aopposing each other with respect to the center C of the unit region SP and respectively including a side parallel to the first direction D1, and a pair of longitudinal portions261bopposing each other with respect to the center C of the unit region SP and respectively including a side parallel to the second direction D2.

The transverse portions261aand the longitudinal portions261badjacent to each other may be connected to each other, as shown inFIG. 5, or may be separated from each other by a predetermined distance. A width W1of the transverse portions261aor the longitudinal portions261bmay be constant or not.

The protrusion261including a pair of transverse portions261aand a pair of longitudinal portions261bare connected to each other to form a closed line, and in this case, the shape of the protrusion261may be an approximate quadrangle.

The protrusion261is formed along at least a portion around the light transmission region of the unit region SP.FIG. 5shows an example in which the protrusion261is formed of the closed line enclosing the entire periphery of the plurality of sub-regions A1, A2, A3, and A4included in the unit region SP. The protrusion261may correspond to the light blocking region enclosing the light transmission region, but is not limited thereto.

Referring toFIG. 6, the protrusion261includes a lateral surface Sa as an inclination surface that is obliquely inclined with respect to an extension direction of the surface of the lower substrate110in the cross-sectional view. The lateral surface Sa of the protrusion261forms a cross-sectional angle Ang1of about 40 degrees to about 50 degrees with the lower surface of the protrusion261or the surface of the lower substrate110; however, it is not limited thereto, and it may be changed depending on a material characteristic of the protrusion261or a manufacturing process.

Referring toFIG. 6, the protrusion261includes a pair of lateral surfaces Sa opposing each other, and the upper surface positioned therebetween may be almost parallel to the lower surface of the protrusion261. However, the upper surface substantially parallel to the lower surface of the protrusion261may be omitted.

A height H1from the lower surface of the protrusion261to the highest upper surface, that is, the top thickness in the cross-sectional view, may be about 0.5 um to about 1.2 um; however, it is not limited thereto, and may be changed depending on a design condition.

Since an alignment layer11as a vertical alignment layer is positioned on the surface of the protrusion261, the liquid crystal molecules31around the surface of the protrusion261may be aligned in a direction almost perpendicular to the surface of the protrusion261. This alignment of the liquid crystal molecules31may be maintained after the electric field is generated in the liquid crystal layer3even when the electric field is no longer generated in the liquid crystal layer3.

When the state in which the liquid crystal molecules31are arranged in the direction almost perpendicular to the surface of the display panel300is referred to as a reference to alignment, the protrusion261controls the liquid crystal molecules31of the peripherally thereof, and particularly, adjacent to the lateral surface Sa, to have the pretilt in the direction toward the inside of the sub-regions A1, A2, A3, and A4in the plan view even when the electric field is no longer generated in the liquid crystal layer. The pretilt direction is a direction forming an acute angle with a normal direction (referred to as a reference alignment direction) almost perpendicular to the surface of the lower substrate110, and the pretilt angle thereof may be about 30 degrees or more.

The pretilt of the liquid crystal molecules31due to the protrusion261allows the liquid crystal molecules31positioned in the sub-regions A1, A2, A3, and A4with the inclination directions a1, a2, a3, and a4to be quickly arranged when the electric field is generated in the liquid crystal layer.

In a traditional display panel, if the liquid crystal layer of the display panel300is pushed by an external pressure such that the arrangement of the liquid crystal molecules31is scattered and the external pressure is removed, the liquid crystal molecules31are not restored and stains may appear. However, according to an exemplary embodiment of the present disclosure, since the protrusion261controls the alignment of the liquid crystal molecules31adjacent thereto in the constant direction, the protrusion261helps the liquid crystal molecules31of the sub-regions A1, A2, A3, and A4to be restored in the original arrangement direction and increases the restoring speed after the pressure is removed after the arrangement of the liquid crystal molecules31is scattered by the external pressure.

As described above, according to an exemplary embodiment of the present disclosure, when the electric field is formed in the liquid crystal layer to display the image, the liquid crystal molecules31may be more quickly arranged in the targeted arrangement direction by the protrusion such that the transmittance may be further increased, and the image further closer to the targeted luminance may be displayed, thereby improving the display quality.

According to an exemplary embodiment of the present disclosure, the lower dams DAM1and DAM2positioned on the inner surface of the substrate110and the protrusion261are positioned at the same layer, include the same material, and are formed by the same process. The dams DAM1and DAM2and the protrusion261may include an organic material. According to an exemplary embodiment of the present disclosure, in the manufacturing process of the liquid crystal display, the dams DAM1and DAM2and the protrusion261may be formed by a photolithography process in exposure and development using one photomask after the organic material is coated on the lower substrate110.

As described above, the dams DAM1and DAM2and the protrusion261that have the different functions and are formed on the different positions are formed by using one photomask such that the manufacturing cost and the manufacturing time may be reduced, and the manufacturing process may be simplified.

Next, one example of the detailed structure of the unit region SP of the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 7as well as the above-described drawings. The same constituent elements as the exemplary embodiment described above designate the same reference numerals, a duplicated description is omitted, and differences are mainly described.

Referring toFIG. 7, the liquid crystal display according to the present exemplary embodiment is the same as most of the above-described exemplary embodiment; however, the structure of the pixel electrode is more concrete.

A unit electrode portion191is positioned in one unit region SP. When one pixel PX includes the plurality of unit regions SP, the unit electrode portion191is a portion of the pixel electrode positioned in the pixel PX, and when one pixel PX includes one unit region SP, the unit electrode portion191may be the pixel electrode positioned in the pixel PX.

The unit electrode portion191has an overall quadrangle shape and includes a cross-shaped stem portion195, which includes a transverse stem portion and a longitudinal stem portion crossing the transverse stem portion, and a plurality of branch portions197. A center of the cross-shaped stem portion195may approximately coincide with the center C of the unit region SP.

The cross-shaped stem portion195extends along the boundary between four sub-regions A1, A2, A3, and A4of the unit region SP. In other words, the unit region SP is divided into four sub-regions A1, A2, A3, and A4by the cross-shaped stem portion195. The transverse stem portion of the cross-shaped stem portion195may extend parallel to the first direction D1, and the longitudinal stem portion may extend parallel to the second direction D2.

The plurality of branch portions197are connected to the cross-shaped stem portion195and extend outwards from the cross-shaped stem portion195. Most of the branch portion197is positioned inside the sub-regions A1, A2, A3, and A4, and a slit in which the electrode is removed is formed between the adjacent branch portions197positioned in each of the sub-regions A1, A2, A3, and A4. The positions where the branch portion197positioned in two of sub-regions A1, A2, A3, and A4adjacent in the first direction D1or the second direction D2meet the cross-shaped stem portion195are not the same but may be alternately disposed.

Although not shown, at least portions of the ends of the branch portions197are connected to each other, thereby forming an outer border of the unit electrode portion191.

The acute angle between the branch portion197and the extension direction of the transverse stem portion of the cross-shaped stem portion195may be about 40 degrees to about 50 degrees; however it is not limited thereto, and it may be approximately controlled by considering the display characteristic such as the visibility of the display device.

According to an exemplary embodiment of the present disclosure, the unit region SP includes the protrusion261as described above, and the protrusion261may be positioned on or under the unit electrode portion191. Hereafter, an example in which the protrusion261is positioned on the unit electrode portion191is described.

The side of the end of the branch portion197may or may not overlap the protrusion261.FIG. 7shows an example in which the side of the end of the branch portion197overlaps the protrusion261. In this case, the efficiency of the light transmission region of the unit region SP is further increased.

Although not shown, the display panel300further includes an opposed electrode disposed opposite to the unit electrode portion191with the liquid crystal layer in between. The opposed electrode is the field generating electrode generating the electric field in the liquid crystal layer along the pixel electrode. A difference between the data voltage applied to the pixel electrode and the voltage applied to the opposed electrode may be changed depending on the gray of the image signal corresponding to the pixel PX. The opposed electrodes positioned in the plurality of pixels PX of the display panel300are connected to be transmitted with the same voltage. The opposed electrode may be formed of one plate without any cutout. The opposed electrode may be positioned on the inner surface of the above-described upper substrate210.

Next, a display operation of the liquid crystal display according to an exemplary embodiment of the present disclosure is described.

If the thin film transistor connected to the pixel electrode including the unit electrode portion191is turned on, the data voltage is applied to the pixel electrode. The opposed electrode applied with the predetermined voltage, such as the common voltage, forms the electric field in the liquid crystal layer3along the pixel electrode. The electric field includes a vertical component in the direction almost perpendicular to the surface of the display panel300, and the liquid crystal molecules31are inclined in the direction almost parallel to the surface of the display panel300due to the vertical component of the electric field. In this case, the edge of the branch portion197of the unit electrode portion191generates a fringe field. The liquid crystal molecules31near the branch portions197are inclined toward the inside of the branch portions197by the fringe field. Resultantly, the liquid crystal molecules31are inclined approximately toward the center C and in the direction approximately parallel to the extension direction of the branch portions197. Accordingly, the inclination directions of the liquid crystal molecules31are different from each other in four sub-regions A1, A2, A3, and A4, and may be the same as the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31shown inFIG. 5described above.

As described above, the protrusion261provides the pretilt to the liquid crystal molecules31near it, increasing the control force (referred to as a liquid crystal alignment control force) rearranging the liquid crystal molecules31and the response speed. The rest of the effects by the protrusion261are the same as described earlier.

According to an exemplary embodiment of the present disclosure, the control force of the liquid crystal molecules31may be sufficiently obtained even if alignment aids are not included in the alignment layer or the liquid crystal layer. Accordingly, without addition of the complicated manufacturing process to form the alignment aids, the display device having the liquid crystal alignment control force and the transmittance may be provided.

Next, various examples of the detailed structure of the unit region SP of the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 8toFIG. 14as well as the above-described drawings.

First, referring toFIG. 8andFIG. 9, the liquid crystal display according to the present exemplary embodiment is the same as most of the exemplary embodiment shown inFIG. 5andFIG. 6except for the shape of the protrusion261.

The protrusion261further includes a corner portion261chaving an oblique side Ea parallel to the direction oblique with respect to the first direction D1and the second direction D2. The corner portion261cis positioned between the transverse portion261aand the longitudinal portion261badjacent to each other. The corner portion261cmay be approximately triangular including the oblique side Ea. Among the sides of the corner portion261c, two sides except for the oblique side Ea may be respectively parallel to the first direction D1and the second direction D2. The oblique side Ea of the corner portion261cmay be connected to the side of the transverse portion261aand the side of the longitudinal portion261badjacent thereto as shown, or may be separated by a predetermined distance.

A pair of transverse portion261aand a pair of longitudinal portion261bof the protrusion261and four corner portions261cmay be connected to each other, thereby forming the closed line.

The oblique side Ea of the corner portion261cmay form the angle Ang of more than about 40 degrees to less than 90 degrees with the first direction D1. Here, the angle Ang may be acute. The extension direction of the oblique side Ea may cross the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31in the sub-regions A1, A2, A3, and A4, and in detail, two directions may be about perpendicular to each other.

A distance W2between the oblique side Ea of the corner portion261cand the vertex opposing thereto may be equal to or less than the width W1of the transverse portion261aor the longitudinal portion261bbut is not limited thereto.

Referring toFIG. 8andFIG. 9, the oblique side Ea of the corner portion261ccorresponds to a bottom surface of the lateral surface Sa of the corner portion261cin the cross-sectional view. The cross-sectional angle Ang1of the lateral surface Sa of the protrusion261with the lower surface of the protrusion261or the surface of the lower substrate110may be about 40 degrees to about 50 degrees; however, it is not limited thereto, and it may be changed depending on the material characteristic of the protrusion261or the manufacturing process.

The corner portion261cof the protrusion261controls the liquid crystal molecules31adjacent thereto to previously have a pretilt in the inclination directions a1, a2, a3, and a4. That is, for the corner portion261c, since the direction perpendicular to the oblique side Ea is toward the center C of the unit region SP in the plan view, the liquid crystal molecules31near the corner portion261care previously pretilted in the inclination directions a1, a2, a3, and a4when the electric field is generated in the liquid crystal layer such that they are more quickly arranged in the inclination directions a1, a2, a3, and a4on the rearrangement, thereby increasing the response speed of the liquid crystal display and increasing the transmittance.

InFIG. 8, the angle Ang is about 45 degrees, and the corner portion261cmay control the liquid crystal molecules31positioned in the sub-regions A1, A2, A3, and A4to be more quickly arranged in the direction toward the center C.

In a traditional display panel, if the liquid crystal layer of the display panel300is pushed by the external pressure such that the arrangement of the liquid crystal molecules31is scattered, the liquid crystal molecules31are not restored and are recognized as the stain even after the external pressure is removed. However, according to an exemplary embodiment of the present disclosure, the corner portion261cof the protrusion261controls the liquid crystal molecules31to be more quickly restored in the inclination directions a1, a2, a3, and a4.

When the angle Ang is larger than about 45 degrees, the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31may be controlled by the corner portion261cto be less than about 45 degrees with the first direction D1. In this case, when the electric field is generated in the liquid crystal layer, the liquid crystal molecules31may be inclined in the direction closer to the first direction D1than the second direction D2such that the lateral visibility may be further improved.

Next, referring toFIG. 10, the liquid crystal display according to the present exemplary embodiment is the same as most of the exemplary embodiment shown inFIG. 7; however, the shape of the protrusion261may be the same as the protrusion261of the exemplary embodiment shown inFIG. 8andFIG. 9. As described above, the protrusion261provides the pretilt to the liquid crystal molecules31therearound, thereby increasing the liquid crystal alignment control force rearranging the liquid crystal molecules31and the response speed. Particularly, like the region Ra shown inFIG. 10, the corner portion261cof the protrusion261provides the pretilt close to the direction in which the liquid crystal molecules31are inclined to the liquid crystal molecules31such that the liquid crystal alignment control force may be further increased and the response speed of the liquid crystal molecules31may be increased.

Next, referring toFIG. 11, the liquid crystal display according to the present exemplary embodiment is the same as most of the above-described exemplary embodiment; however, the structure of the unit electrode portion191may be different.

The unit electrode portion191may include a planar portion198of at least one whole plate positioned at at least one of four corners. When the unit electrode portion191is approximately quadrangle, at least one planar portion198is respectively positioned at at least one of the quadrangle corners.FIG. 11shows an example in which the planar portion198is respectively positioned on four corners of the unit electrode portion191.

The electrode forming the planar portion198is not patterned, thereby having the continuous surface without the opening such as the slit.

One planar portion198may be a polygon including the oblique side Eb positioned in one of the sub-regions A1, A2, A3, and A4, for example, a triangle. The planar portion198may be the triangle including one vertex opposing the oblique side Eb while corresponding to the vertex of the unit electrode portion191, one vertex positioned on the transverse side of the unit electrode portion191, and one vertex positioned on the longitudinal side of the unit electrode portion191. The oblique side Eb extends in the direction crossing the extension direction of the branch portion197in each of the sub-regions A1, A2, A3, and A4, and in detail, may be approximately perpendicular to the extension direction of the branch portion197. The planar portion198may include two sides forming the outer part of the unit electrode portion191and connected to the oblique side Eb.

Among the vertices of the planar portion198, the vertices positioned on the transverse side and the longitudinal side of the unit electrode portion191and the vertex positioned at the end of the oblique side Eb may be positioned between the vertex of the unit electrode portion191and the end of the longitudinal stem portion of the cross-shaped stem portion195. Accordingly, the planar portion198may occupy an area of less than about 50% in each of the sub-regions A1, A2, A3, and A4. In this case, the distance between the oblique side Eb of the planar portion198and the vertex opposing thereto may be less about 50% of the diagonal length of each of the sub-regions A1, A2, A3, and A4.

The oblique side Eb of the planar portion198forms the angle of about 40 degrees to about 50 degrees with the extension direction of the transverse stem portion of the cross-shaped stem portion195, that is, the first direction D1. Particularly, the oblique side Eb of the planar portion198may be almost parallel to the oblique side Ea of the corner portion261cof the protrusion261. The oblique side Ea of the corner portion261cof the protrusion261overlaps the inner region of the planar portion198.

As described above, if the unit electrode portion191includes the planar portion198, the liquid crystal control force arises from the fringe field generated by the oblique side Eb of the planar portion198such that the transmittance of the display device may be further increased.

Referring toFIG. 10, the liquid crystal molecules31near the edge of the branch portion197are not arranged parallel to the extension direction of the branch portion197, but tend to be arranged further toward the inside branch portion197. Accordingly, the transmittance is partially decreased on the edge of the branch portion197such that a dark portion may be recognized. In contrast, in the embodiment ofFIG. 11, because the unit electrode portion191includes the planar portion198, the dark portion near the branch portion197is decreased such that the entire transmittance of the unit region SP may be increased.

In more detail, because the slit (not shown) or the branch portion197is not formed in the planar portion198ofFIG. 11, the control force may not be sufficient on the rearrangement of the liquid crystal molecules31. However, because the planar portion198is positioned at the position near the corner portion261cof the protrusion261, the liquid crystal control force is reinforced by the corner portion261csuch that the arrangement direction of the liquid crystal molecules31corresponding to the planar portion198may be effectively controlled. Accordingly, the sufficient transmittance may be obtained.

The planar portion198is electrically connected to the cross-shaped stem portion195through a separate connection (not shown). Referring toFIG. 11, the planar portion198is separated from the end of the adjacent branch portion197by a predetermined distance. However, the present disclosure is not limited thereto, and the planar portion198and the adjacent branch portion197may be connected to each other.

Next, referring toFIG. 12andFIG. 13, the liquid crystal display according to the present exemplary embodiment is the same as the exemplary embodiment shown inFIG. 10except for the structure of the protrusion261. The protrusion261according to the present exemplary embodiment includes an inclined corner portion261dinstead of the above-described corner portion261c.

The inclined corner portion261dmay be approximately triangular including the oblique side Ec parallel to the direction oblique with respect to the first direction D1and the second direction D2. Among the sides of the inclined corner portion261d, two sides except for the oblique side Ec may be approximately parallel to the first direction D1or the second direction D2. The oblique side Ec of the inclined corner portion261d, as shown inFIG. 12, may be connected to the side of the transverse portion261aand the side of the longitudinal portion261b; however, they may be separated by the predetermined distance. The inclined corner portion261dis respectively positioned at at least one corner of the unit region SP and is positioned between the transverse portion261aand the longitudinal portion261badjacent to each other.

A pair of transverse portions261a, a pair of longitudinal portions261b, and four inclined corner portions261dmay be connected to each other, thereby forming the approximate closed line. In this case, the outer shape of the protrusion261may be about quadrangular.

The oblique side Ec of the inclined corner portion261dmay form the angle Ang2of more than about 40 degree to less than 90 degrees with the first direction D1in the plan view. Here, the angle Ang2may be acute. The extension direction of the oblique side Ec crosses the inclination directions a1, a2, a3, and a4of the liquid crystal molecules31in each of the sub-regions A1, A2, A3, and A4, and in detail, two directions may be approximate perpendicular.

The distance d2between the oblique side Ec of the inclined corner portion261dand the vertex opposing thereto may be less than about 50% of the length of the diagonal direction of each of the sub-regions A1, A2, A3, and A4.

The transverse portion261aand the longitudinal portion261bof the protrusion261may correspond to the light blocking region enclosing the light transmission region, and most of the inclined corner portion261dmay correspond to the light transmission region. That is, the light is transmitted in the region where the inclined corner portion261dis positioned, thereby displaying the image.

Referring toFIG. 12andFIG. 13, the transverse portion261aand the longitudinal portion261bof the protrusion261include a lateral surface Sa as the inclination surface that is obliquely inclined with respect to the lower surface of the protrusion261in the cross-sectional view, and the inclined corner portion261dof the protrusion261includes a lateral surface Sb as the inclination surface that is obliquely inclined with respect to the lower surface of the protrusion261. The slope of the lower surface of the lateral surface Sa and the slope of the lower surface of the lateral surface Sb may be different, and the inclination of the lateral surface Sb may be smoother than the inclination of the lateral surface Sa.

A cross-section angle Ang3of the lateral surface Sb of the inclined corner portion261dwith the lower surface of the protrusion261may be about 1 degree to about 2 degrees; however, it is not limited thereto, and it may be changed depending on the material characteristic of the protrusion261or the manufacturing process.

A height H10from the lower surface of the inclined corner portion261dto the highest upper surface, that is, the highest thickness, may be less than about 0.5 um; however, it is not limited thereto, and it may be changed depending on the design conditions. Particularly, since the inclined corner portion261dcorresponds to the light transmission region of each sub-region A1, A2, A3, and A4of the unit region SP, to obtain more than the predetermined transmittance, it may be beneficial to limit the thickness of the inclined corner portion261d.

The outer part of the inclined corner portion261dis connected to the transverse portion261aor the longitudinal portion261bof the protrusion261. The highest height H10of the inclined corner portion261dmay be smaller than the thickness of the transverse portion261aor the longitudinal portion261bof the protrusion261.

The oblique side Ec of the inclined corner portion261dof the protrusion261in the plan view corresponds to the bottom side of the lateral surface Sb of the inclined corner portion261din the cross-sectional view.

A state in which the liquid crystal molecules31are arranged in the direction approximate perpendicular to the surface of the display panel300is referred to as a reference alignment, and the inclined corner portion261dcontrols the liquid crystal molecules31adjacent to the lateral surface Sb thereof to have the pretilt in the direction toward the inside of each sub-region A1, A2, A3, and A4even when the electric field is not generated in the liquid crystal layer. The pretilt direction of the liquid crystal molecules31is the direction forming the acute angle with the reference alignment direction DR approximate perpendicular to the surface of the lower substrate110, and a pretilt angel Ap thereof may be about 1 degree to about 2 degrees, for example.

The pretilt of the liquid crystal molecules31by the protrusion261allows the liquid crystal molecules31positioned in the sub-regions A1, A2, A3, and A4to be quickly arranged in the inclination directions a1, a2, a3, and a4when the electric field is generated in the liquid crystal layer.

Particularly, for the inclined corner portion261d, since the direction perpendicular to the oblique side Ec thereof is almost toward the center C of the unit region SP, the liquid crystal molecules31near the inclined corner portion261dare previously pretilted in the inclination directions a1, a2, a3, and a4when the electric field is generated in the liquid crystal layer such that the rearrangement speed is faster, thereby increasing the response speed and the transmittance of the display device. Next, referring toFIG. 14, the liquid crystal display according to the present exemplary embodiment is the same as most of the exemplary embodiment shown inFIG. 12andFIG. 13; however, the structure of the unit electrode portion191may be the same as the unit electrode portion of the exemplary embodiment shown inFIG. 11. The description thereof was previously given, and as such, a detailed description thereof is omitted hereafter.

The oblique side Ec of the inclined corner portion261dmay overlap the inside of the planar portion198. The oblique side Ec of the inclined corner portion261dand the oblique side Eb of the planar portion198may be approximately parallel to each other.

In the manufacturing process of the liquid crystal display according to an exemplary embodiment of the present disclosure, the protrusion261and the dams DAM1and DAM2may be formed through the exposure using the photomask and the photolithography process using the developing after coating the organic material on the lower substrate110. In this case, the light transmittance of the photomask corresponding to the transverse portion261aand the longitudinal portion261bof the protrusion261may be constant, and the light transmittance of the photomask corresponding to the inclined corner portion261dmay be different from the light transmittance of the photomask corresponding to the transverse portion261aand the longitudinal portion261b. If the organic material has negative photosensitivity such that a portion irradiated by light is maintained, the light transmittance of the photomask corresponding to the inclined corner portion261dis lower than the light transmittance of the photomask corresponding to the transverse portion261aand the longitudinal portion261b, and the light may be less irradiated to the organic material layer in the exposure process.

To form the inclined corner portion261dto have the lateral surface Sb having the smooth inclination, the photomask region corresponding to the inclined corner portion261dmay have different light transmittance depending on the position. If the material of the protrusion261has the negative photosensitivity such that the portion irradiated by the light is maintained, the light transmittance of the photomask corresponding to the inclined corner portion261dmay be decreased toward the oblique side Ec from the vertex opposing the oblique side Ec of the inclined corner portion261d. The light transmittance change of the photomask corresponding to the inclined corner portion261dmay be step-by-step like a step shape or may be gradual.

Next, the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 15toFIG. 17Bas well as the above-described drawings.

The liquid crystal display according to the exemplary embodiment of the present disclosure may include lower and upper panels100and200opposing each other, and a liquid crystal layer3positioned between the two panels100and200in the cross-sectional structure.

The lower panel100is described first. A gate conductor including a plurality of gate lines121and a plurality of reference voltage lines131is disposed on an inner surface of the substrate110. Here, the inner surface of the substrate means the surface opposing the liquid crystal layer3.

Each gate line121mainly extends in the first direction D1as a horizontal direction, and may include a first gate electrode124a, a second gate electrode124b, and a third gate electrode124cthat protrude in a vertical direction.

Each reference voltage line131may mainly extend parallel to the first direction D1while being separated from the gate line121. The reference voltage line131may transmit a reference voltage, which may be an AC voltage or a constant DC voltage, such as a common voltage Vcom or the like.

The reference voltage line131may include an extension portion131amainly extending in the horizontal direction, a longitudinal portion131bextended from the extension portion131aup and down and approximately parallel to the second direction D2, and a transverse portion131cconnected to the longitudinal portion131band mainly extending in the first direction D1.

A gate insulating layer140is disposed on the gate conductors, and a semiconductor layer including a first semiconductor154a, a second semiconductor154b, and a third semiconductor154cis disposed the gate insulating layer140. The first and second semiconductors154aand154bmay be connected to each other. The first semiconductor154amay overlap the first gate electrode124a, the second semiconductor154bmay overlap the second gate electrode124b, and the third semiconductor154cmay overlap the third gate electrode124c.

The semiconductor layer may include amorphous silicon, polycrystalline silicon, an oxide semiconductor metal oxide, or the like.

A plurality of ohmic contacts163aand165amay be positioned on the semiconductor layer. The ohmic contacts163aand165amay be formed of silicide or a material such as n+ hydrogenated amorphous silicon in which an n-type impurity is doped at a high concentration. The ohmic contacts163aand165amay be omitted.

A data conductor including a plurality of data lines171including a first source electrode173aand a second source electrode173b, a first drain electrode175a, a second drain electrode175b, a third source electrode173c, and a third drain electrode175cis disposed on the ohmic contacts163aand165aand the gate insulating layer140.

Each data line171transmits a data signal, and mainly extends in the second direction D2as a vertical direction to cross the gate line121and the reference voltage line131.

The first source electrode173aprotrudes from the data line171toward the first gate electrode124ato oppose the first drain electrode175a, and the second source electrode173bprotrudes from the data line171toward the second gate electrode124bto oppose the second source electrode173b.

The first and second source electrodes173aand173bare connected to each other, and the second drain electrode175band the third source electrode173care connected to each other. The third source electrode173cand the third drain electrode175coppose each other.

One of end portions of the third drain electrode175cthat does not oppose the third source electrode173cmay be adjacent to or overlap the reference voltage line131.

The first gate electrode124a, the first source electrode173a, and the first drain electrode175aform a first thin film transistor Qa along with the first semiconductor154ato serve as a first switching element. The second gate electrode124b, the second source electrode173b, and the second drain electrode175bform a second thin film transistor Qb along with the second semiconductor154bto serve as a second switching element. The third gate electrode124c, the third source electrode173c, and the third drain electrode175cform a third thin film transistor Qc along with the third semiconductor154cto serve as a voltage-dividing switching element.

The gate line121, the reference voltage line131, and the first to third thin film transistors Qa, Qb, and Qc may be positioned corresponding to the thin film transistor region TRA shown inFIG. 4.

A first insulating layer180ais positioned on the data conductor and the exposed portion of the semiconductors154a,154b, and154c. The first insulating layer180amay be formed of an organic insulating material or an inorganic insulating material, and may include a single layer or multiple layers.

An organic layer may be positioned on the first insulating layer180a. For example, the organic layer may include a color filter230. The first color filter230may display one of three primary colors, such as red, green, and blue, or four primary colors. The first color filter230is not limited to the three primary colors of red, green, and blue, but may represent cyan, magenta, yellow, white-based colors, and the like.

The color filter230may extend along each pixel array. The color filter230may include an opening (not shown) respectively positioned on the portions of the drain electrodes175a,175b, and175c.

A second insulating layer180bis formed on the color filter230. The second insulating layer180bmay include an inorganic insulating material or an organic insulating material. The second insulating layer180bas an overcoat for the color filter230prevents the color filter230from being exposed, thereby preventing an impurity, such as a pigment of the color filter230, from flowing into the liquid crystal layer3. The second insulating layer180bmay be omitted.

The first insulating layer180aand the second insulating layer180binclude a first contact hole185aexposing a portion of the first drain electrode175aand a second contact hole185bexposing a portion of the second drain electrode175b. The first and second contact holes185aand185bmay be positioned in the opening of the color filter230, respectively.

The gate insulating layer140and the first and second insulating layers180aand180bmay further include a contact hole185cfor partially exposing both the portion of the third drain electrode175cand the portion of the reference voltage line131.

A pixel electrode layer including a plurality of pixel electrodes and connection electrodes192and193is formed on the second insulating layer180b.

The pixel electrode positioned at one pixel PX may be formed of one electrode that is entirely connected, and may include a plurality of sub-pixel electrodes. In the current exemplary embodiment, one pixel electrode including a first sub-pixel electrode191aand a second sub-pixel electrode191bis exemplarily described.

As described above, one pixel PX includes the plurality of unit regions SP. Accordingly, one pixel electrode may include a plurality of unit electrode portions191like the above-described exemplary embodiment. Also, when one pixel electrode includes the first sub-pixel electrode191aand the second sub-pixel electrode191bthat are separated from each other, the sub-pixel electrodes191aand191bmay include a plurality of unit electrode portions191like the above-described exemplary embodiment to sufficiently obtain the liquid crystal control force.FIG. 15is an example in which the first sub-pixel electrode191aincludes four unit electrode portions191connected to each other and the second sub-pixel electrode191bincludes six unit electrode portions191connected to each other. The number of unit electrode portions191included in one pixel PX may be different considering the liquid crystal control force depending on the area of the pixel PX.

The structure of the unit electrode portion191is the same as the above-described exemplary embodiments, and as such, a detailed description thereof is omitted hereafter.

The first sub-pixel electrode191aand the second sub-pixel electrode191bmay disposed on opposite sides of the gate line121, the reference voltage line131, and the first to third thin film transistors Qa, Qb, and Qc interposed therebetween; however, the arrangement shape is not limited thereto and may be variously changed.

The first subpixel electrode191aand the second subpixel electrode191bare physically and electrically connected to the first drain electrode175aand the second drain electrode175bthrough the contact holes185aand185b, respectively. The first subpixel electrode191amay be applied with the data voltage from the drain electrode175a, and the second subpixel electrode191bmay be applied with a divided voltage between the data voltage transmitted through the second drain electrode175band the reference voltage transmitted through the reference voltage line131.

The third drain electrode175cand the reference voltage line131may be connected to each other through the connection electrode192in the third contact hole185c.

The connection electrode192may include a contact portion192ccontacting the third drain electrode175cand the portion of the reference voltage line131, a longitudinal portion192aextending upward from the contact portion192c, and a longitudinal portion192bextending downward from the contact portion192c. The longitudinal portions192aand192bare separated from the first and second sub-pixel electrodes191aand191b, and may be approximately parallel to the second direction D2. The longitudinal portions192aand192bmay overlap the data line171. The longitudinal portions192aand192belectrically connect a plurality of reference voltage lines131, thereby preventing a change of the reference voltage transmitted by the reference voltage line131. Also, the longitudinal portions192aand192bshield an electromagnetic field caused by the data voltage of the data line171, thereby shielding the voltages of the adjacent pixel electrodes from being distorted by the change of the data voltage.

The connection electrode193and the connection electrode192may be alternately disposed in the first direction D1and oppose each other via the pixel electrode. The structure and the function of the connection electrode193may be substantially the same as the connection electrode192.

The pixel electrode layer may include a transparent conductive material such as indium-tin oxide (ITO), indium-zinc oxide (IZO), or a metal thin film.

The structure of the pixel PX described in the present exemplary embodiment is only one example, and numerous variations may be provided.

A light blocking member221is positioned on the pixel electrode layer. The light blocking member221may be referred to as a black matrix, and may prevent the transmission of light. Accordingly, the region where the light blocking member221is formed is included in the light blocking region.

The light blocking member221according to the present exemplary embodiment may include a main light blocking portion221a, a spacer221b, and a protrusion261like the above-described exemplary embodiment. Also, the light blocking member221may include at least one of dams DAM1and DAM2positioned in the peripheral area PA as described above.

The main light blocking portion221aincludes a portion in the light blocking region including the region where the first to third thin film transistors Qa, Qb, and Qc are positioned. The main light blocking portion221amay prevent the light leakage between the light transmission region in which the first sub-pixel electrode191ais positioned and the light transmission region in which the second sub-pixel electrode191bis positioned, and between the light transmission regions of the neighboring pixels PX.

The main light blocking portion221amay include a portion overlapping the contact holes185a,185b, and185c, and this portion fills the large step on the contact holes185a,185b, and185c, thereby flattening the surface and preventing the light leakage on the surrounding thereof.

The spacer221bmay be connected to the main light blocking portion221aor separated from the main light blocking portion221a. The spacer221bmay be positioned on a portion of at least one of the first to third thin film transistors Qa, Qb, and Qc and/or the signal line such as the gate line121, the reference voltage line131, and the data line171.

The spacer221bmay be a main spacer maintaining and supporting the cell gap between the upper panel200and the lower panel100and a sub-spacer maintaining and supporting the cell gap between the upper panel200in the normal state (i.e., no external pressure applied) and the lower panel100when an external pressure is applied to the display device and the distance between the upper panel200and the lower panel100is decreased. If the spacer221bis the sub-spacer, the top surface of the spacer221bmay not contact the inner surface of the upper panel200when no pressure is applied. The height of the top surface of the spacer221bmay be higher than the height of the top surface of the most of the main light blocking portion221a.

The liquid crystal molecules31adjacent to the lateral surface Sa of the protrusion261in the cross-sectional view may be initially aligned in the direction approximately perpendicular to the lateral surface Sa, and this alignment state may also be maintained when the electric field is not generated in the liquid crystal layer3. The other characteristics of the protrusion261and the effects thereof are the same as described above, and as such, a detailed description is omitted hereafter.

The protrusion261and the above-described dams DAM1and DAM2may be positioned at the same layer as or may include the same material as the main light blocking portion221aof the light blocking member221or the spacer221b. The highest thickness of the protrusion261may be thicker than or similar to the average thickness of the main light blocking portion221a.FIG. 16shows an example in which the highest thickness of the protrusion261may be thicker than the thickness of the main light blocking portion221apositioned therearound, but it is not limited thereto. The vertical thickness of the dams DAM1and DAM2positioned in the peripheral area PA in the cross-sectional view may be the same as or smaller or larger than the highest thickness of the protrusion261. This may be approximately controlled depending on the design condition.

The height of the top surface of the spacer221bis higher than the height of the top surface of the dams DAM1and DAM2and the protrusion261.

The light blocking member221may include a pigment, such as carbon black, and an organic material having photosensitivity.

The light blocking member221of the lower panel100including the main light blocking portion221a, the spacer221b, the protrusion261, and the dams DAM1and DAM2may be formed by using one photomask. This is described later.

According to an exemplary embodiment of the present disclosure, if the color filter230and/or the light blocking member221are positioned on the lower panel100along the first to third thin film transistors Qa, Qb, and Qc, the alignment between the light blocking member221and the color filter230and the pixel electrode and the thin film transistors Qa, Qb, and Qc may be easily adjusted, thereby reducing the alignment error.

An alignment layer11is formed on the light blocking member221, and the alignment layer11may be a vertical alignment layer.

Referring to the upper panel200, an opposed electrode270may be positioned on the inner surface of the upper substrate210. The opposed electrode270with a surface shape without a cutout may be formed in the whole plate of the entire surface of the upper substrate210. The opposed electrode270may be transmitted with a common voltage Vcom of a predetermined magnitude. The opposed electrode270may include the transparent conductive material such as ITO, IZO, and a metal thin film.

An alignment layer21is formed on the opposed electrode270, and the alignment layer21may be a vertical alignment layer.

The liquid crystal layer3includes the plurality of liquid crystal molecules31. The liquid crystal molecules31may have negative dielectric anisotropy and may be initially aligned in the direction approximately perpendicular to the surfaces of the panels110and210when no electric field is generated in the liquid crystal layer3. The liquid crystal molecules31may be pretilted in the direction approximately perpendicular to the surface of the protrusion261, particularly around the protrusion261.

The pixel electrode and the opposed electrode270are applied with the voltages to generate the electric field in the liquid crystal layer3such that the arrangement direction of the liquid crystal molecules31is controlled, thereby displaying the image.

Alternatively, the color filter230may be positioned on the upper panel200. In this case, the color filter230may be positioned between the upper substrate210and the opposed electrode270, and an insulating layer (not shown) may be further positioned between the color filter230and the liquid crystal layer3. In this case, the lower panel100may further include a third insulating layer (not shown) positioned between the first insulating layer180aand the second insulating layer180b. The third insulating layer may include an organic material and may provide the flat upper surface.

FIG. 17AandFIG. 17Bshow the cross-sectional structure of another example of the liquid crystal display shown inFIG. 15.

Referring toFIG. 17A,FIG. 17B, andFIG. 20, at least one of the color filter230and the light blocking member220may be positioned in the upper panel200.FIG. 17AandFIG. 17Bshow examples in which the color filter230and the light blocking member220are both positioned in the upper panel200.

The light blocking member220may be positioned between the upper substrate210and the color filter230or may be positioned on the color filter230. An overcoat250may be positioned on the light blocking member220and the color filter230, and the opposed electrode270may be positioned on the overcoat250. The light blocking member220may have a similar structure and function to the above-described main light blocking portion221a.

The lower panel100may include a third insulating layer180cpositioned between the first insulating layer180aand the second insulating layer180b. The third insulating layer180cmay include an organic material and may provide the flat upper surface.

Referring toFIG. 17A, the lower panel100is the same as most of the above-described lower panel, however a spacer222and the protrusion261may be positioned on the pixel electrode layer. The height of the top surface of the spacer222is higher than the top surface of the dams DAM1and DAM2and the protrusion261.

Referring toFIG. 17B, the present exemplary embodiment is the same as most ofFIG. 17A; however, the spacer222may be positioned in the upper panel200. In this case, the dams DAM3and DAM4of the upper panel may be formed with the same material and layer in the same process as the spacer222. In this case, the height of the top surface of the spacer222is higher than the height of the top surface of the dams DAM3and DAM4.

The spacer222may have an island shape. The spacer222may be positioned to overlap the light blocking region of the pixel PX, particularly to overlap a portion of at least one of the first to third thin film transistors Qa, Qb, and Qc and/or the signal line such as the gate line121, the reference voltage line131, and the data line171. The spacer222may have a similar structure and function as the above-described spacer221b.

The protrusion261may have the structure and function according to the above-described several exemplary embodiments. The protrusion261may be positioned at the same layer as the above-described dams DAM1and DAM2, may include the same material, and may be formed in the same process. This is described later. When the spacer222is positioned in the lower panel100as shown inFIG. 17A, the spacer222may be positioned at the same layer as the protrusion261, and the dams DAM1and DAM2and may include the same material.

The material together included in the protrusion261and the dams DAM1and DAM2may be transparent or may include a light blocking material. When the protrusion261includes the transparent material, little or no light is transmitted in the region where the protrusion261is formed such that most of the protrusion261may be included in the light blocking region.

The highest thickness of the protrusion261in the cross-sectional view is smaller than thickness of the spacer222in the cross-sectional view.

According to an exemplary embodiment of the present disclosure, the protrusion261may be positioned between the pixel electrode including the unit electrode portion191and the liquid crystal layer3; however, the protrusion261may be alternatively positioned at the layer between the lower substrate110and the pixel electrode. When the protrusion261is positioned between the lower substrate110and the pixel electrode, the step of the protrusion261is transmitted to the inner surface of the lower panel100such that the highest surface positioned on the protrusion261is protruded to the liquid crystal layer3such that the liquid crystal molecules31may be pretilted.

Differently fromFIG. 17AandFIG. 17B, the light blocking member220may be positioned in the lower panel100. In this case, the third insulating layer180cmay be omitted, and the light blocking member220may be positioned thereon. Otherwise, the light blocking member220may be positioned on or under the third insulating layer180c.

Next, a manufacturing method of the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 18toFIG. 25as well as the above-described drawings.

Firstly, referring toFIG. 18, the lower substrate110including the insulating material is provided, and a plurality of thin film layers TFS are formed thereon.

The lower substrate110includes the display area DA and the peripheral area PA positioned in the vicinity thereof, and the thin film layer TFS may include the portion positioned in the display area DA and the portion positioned in the peripheral area PA. At least a portion among the plurality of thin film layers TFS may be patterned in the plan view. The plurality of thin film layers TFS may include at least one conductive layer, the semiconductor layer, and at least one insulating layer.

Next, an insulating layer ISL is formed on the lower substrate110and the thin film layer TFS. The insulating layer ISL may include an inorganic insulating material or/and an organic insulating material, and may be patterned.FIG. 18shows an example in which at least a portion of the insulating layer ISL may be removed in the peripheral area PA.

Next, the transparent conductive material such as ITO, ITO is deposited and patterned on the insulating layer ISL to form a pixel electrode layer PXL including a plurality of pixel electrodes. The plurality of pixel electrodes are mainly positioned in the display area DA.

Next, referring toFIG. 19, a photosensitive material260is deposited on the entire surface of the lower substrate110. The photosensitive material260may be the same as a material of the dams DAM1and DAM2, and the protrusion261may include an organic material.

Next, a photomask50is positioned on the photosensitive material260, and the exposure is performed. The photomask50includes portions having different light transmittances. For example, when the photosensitive material260has negative photosensitivity such that a portion irradiated by light is maintained, among the photomask50, the regions SA1and SA2corresponding to the portions where the dams DAM1and DAM2are formed and the region SA0corresponding to the portion where the protrusion261is formed have predetermined light transmittance that is not 0, and the region OA corresponding to the portion where the photosensitive material260is mainly removed may have a lower light transmittance. The region OA of the photomask50may be substantially the light blocking region and may be opaque. The photomask50may further include a light transmission region (not shown) corresponding to the position where the photosensitive material260is maintained, and a light semi-transmission region or a light blocking region of another position may be further included.

Particularly, the regions SA0, SA1, and SA2of the photomask50may be the light semi-transmission region, and thus, the regions SA0, SA1, and SA2of the photomask50may have a halftone or a plurality of slits, or a size of the pattern may be controlled to control the light transmittance.

The cross-sectional thicknesses of the dams DAM1and DAM2and the protrusion261are different from each other, and the light transmittance of the regions SA1and SA2of the photomask50and the light transmittance of the region SA0may be different. For example, the thickness of the protrusion261is smaller than the thickness of the dams DAM1and DAM2, and the light transmittance of the region SA0of the photomask50may be lower than the light transmittance of the region SA1and SA2of the photomask50. Likewise, when the thicknesses of the dams DAM1and DAM2of the different positions are different, the light transmittance of the region SA1and the region SA2of the photomask50may be different.

Alternatively, when the photomask50has positive photosensitivity, each light transmittance of the regions SA0, SA1, SA2, and OA of the photomask50may be reversely changed. That is, the region OA of the photomask50may be the light transmission region, the light transmittance of the regions SA0, SA1, and SA2may be controlled to be different, and the region that was the light transmission region may be the light blocking region.

Next, referring toFIG. 20, the photosensitive material260exposed through the photomask50is developed to form a plurality of protrusions261corresponding to the region SA0of the photomask50and dams DAM1and DAM2corresponding to the regions SA1and SA2of the photomask50.FIG. 20shows the example in which the cross-sectional thickness of the protrusion261is smaller than the cross-sectional thickness of the dams DAM1and DAM2. The photosensitive material260of the region except for the protrusion261and the dams DAM1and DAM2may be mainly removed, and there may be a portion where the photosensitive material260is maintained with a predetermined thickness.

When the protrusion261includes the inclined corner portion261dlike the above-described exemplary embodiment, the photomask50corresponding to the inclined corner portion261dmay have a lower light transmittance than the other portion of the protrusion261, for example, the region corresponding to the transverse portion261aor the longitudinal portion261b. As described above, the light transmittance of the photomask is gradually decreased in the direction that the thickness of the inclined corner portion261dis decreased, thereby forming the smooth inclination of the inclined corner portion261d. In this way, the region of the photomask50of which the light transmittance is gradually changed may be formed by gradually controlling a number of the slits or a tone degree of the halftone.

As described above, the dams DAM1and DAM2to control the edge position of the alignment layer11and the protrusion261to control the alignment of the liquid crystal molecules31are formed together of the same material and at the same layer by using the same photomask50, thereby reducing the manufacturing cost and the manufacturing time and simplifying the manufacturing process in the present exemplary embodiment.

Alternately, the formation of the protrusion261and the dams DAM1and DAM2may be performed before forming the pixel electrode layer PXL.

Next, referring toFIG. 21, an aligning agent is coated and dried on the entire inner surface of the lower substrate110formed with the dams DAM1and DAM2and the protrusion261to form the alignment layer11. In this case, the alignment layer11is spread in the entire surface of the display area DA, and the spread may be primary prevented by the dam DAM1at the boundary of the peripheral area PA and the display area DA of the lower substrate110. Even if the aligning agent overflowing over the dams DAM1is generated, the spread is further prevented by at least one of dams DAM2positioned next the dams DAM1such that the position of the edge of the alignment layer11may be controlled, thereby further reducing the width of the peripheral area PA.

The lower panel may be completed through this process.

Next, referring toFIG. 22, the upper substrate210including the insulating material is provided, and a light blocking material is coated to form the light blocking member220. Alternatively, the light blocking member220may be included in the lower panel.

Although not shown, the color filter (not shown) may be further formed on the upper substrate210. Alternatively, the color filter may be positioned in the lower panel.

Next, a conductive material, such as ITO or IZO, is deposited on the light blocking member220to form the opposed electrode270.

Next, referring toFIG. 23, a photosensitive material280is deposited on the opposed electrode270. The photosensitive material280as the material of the spacer may include an organic material.

Next, a photomask51is disposed on the photosensitive material280and the exposure is performed. The photomask51includes the portions having the different light transmittance. For example, when the photosensitive material280has the negative photosensitivity to be maintained by the irradiated light, in the photomask51, the regions SA3and SA4corresponding to the portions where the dams DAM3and DAM4are formed respectively may have a predetermined light transmittance other than 0. In addition, when forming the spacer on the upper substrate210, in the photomask51, the region TA corresponding to the portion where the spacer is formed and the region corresponding to the portion where the rest of the photosensitive material280is maintained may have higher light transmittance than the regions SA3and SA4. In the photomask51, the rest of the region OA corresponding to the portion where the photosensitive material280is mainly removed may have the lowest light transmittance and may substantially be the light blocking region.

Next, referring toFIG. 24, the photosensitive material280exposed through the photomask51is developed to form the spacer222corresponding to the region TA of the photomask51and the dams DAM3and DAM4corresponding to the region SA3and SA4of the photomask51. The photosensitive material280of the region except for the spacer222and the dams DAM3and DAM4may be partially removed, and a portion of the photosensitive material280of the predetermined thickness may be maintained.

Next, referring toFIG. 25, the aligning agent is coated and dried on the inner surface of the upper substrate210formed with the dams DAM3and DAM4and the spacer222to form an alignment layer21. In this case, the alignment layer21is spread on the entire surface of the display area DA, and the spread thereof is primary stopped by the dams DAM3at the boundary of the peripheral area PA and the display area DA of the upper substrate210. Even if the aligning agent overflows the dams DAM3, the aligning agent is prevented from being further spread by at least one of dams DAM4positioned next to the dams DAM3such that the position of the edge of the alignment layer21may be controlled, thereby further reducing the width of the peripheral area PA.

Accordingly, the upper panel may be completed.

A sealant310is positioned between the lower panel and the upper panel, which are combined to manufacture the liquid crystal display according to an exemplary embodiment of the present disclosure, and the structure thereof may be the same as the liquid crystal display shown inFIG. 1toFIG. 15, andFIG. 17B.

Next, a manufacturing method of the liquid crystal display according to an exemplary embodiment of the present disclosure is described with reference toFIG. 26andFIG. 27as well as the above-described drawings.

The manufacturing method of the liquid crystal display according to the present exemplary embodiment is the same as most of the exemplary embodiment shown inFIG. 18toFIG. 25; however, the spacer222may also be formed when forming the protrusion261and the dams DAM1and DAM2of the lower panel.

Referring toFIG. 26, as described above, the photosensitive material260is coated on the lower substrate110, the photomask50is disposed for the exposure, and the photomask50may further include the region TA corresponding to the position to form the spacer. The region TA of the photomask50may have a higher light transmittance than the region SA0, SA1, and SA2.

Accordingly, as shown inFIG. 27, after the exposure and the developing through the photomask50, the spacer222having the higher cross-sectional thickness than the protrusion261and the dams DAM1and DAM2may be formed on the lower substrate110. In the present exemplary embodiment, the photosensitive material260may be transparent or may include the light blocking material.

The structure of the thus manufactured liquid crystal display may be the same as that of the liquid crystal display shown inFIG. 1toFIG. 15andFIG. 17A. In this case, the spacer may be not positioned in the upper panel, and the dams DAM3and DAM4positioned in the upper panel may be formed through a separate photolithography process or may be formed in the same process along with the other layers positioned in the upper panel.

Finally, the manufacturing method of the liquid crystal display according to an exemplary embodiment of the present invention will be descried with reference toFIG. 28as well as the above-described drawings.

The manufacturing method of the liquid crystal display according to the present exemplary embodiment is the same as most of the exemplary embodiment shown inFIG. 18toFIG. 25, however the light blocking member and the spacer may be formed when forming the lower panel, not the upper panel.

Referring toFIG. 28, the photomask50disposed after coating the photosensitive material260on the lower substrate110may further include the region TA corresponding to the position to form the spacer and the region SA5corresponding to the position to form the main light blocking portion. The region TA of the photomask50may have a higher light transmittance than the regions SA0, SA1, and SA2, and the region SA5may have a lower light transmittance than the region TA. The light transmittance of the region SA5may be lower than the light transmittance of the region SA0; however, it is not limited thereto, and it may be higher than or equal thereto.

After the exposure by using the photomask50shown inFIG. 28, the dams DAM1and DAM2respectively corresponding to the light semi-transmission regions SA1and SA2, the protrusion261corresponding to the light semi-transmission region SA0, the main light blocking portion221acorresponding to the light semi-transmission region SA5, and the spacer221bcorresponding to the light transmission region TA are formed.

In the present exemplary embodiment, the photosensitive material260includes the light blocking material.

The structure of the manufactured liquid crystal display may be the same as that of the liquid crystal display shown inFIG. 1toFIG. 15andFIG. 16. That is, the light blocking member221may include the main light blocking portion221a, the spacer221b, and the protrusion261. In this case, the spacer may not be positioned in the upper panel, and the dams DAM3and DAM4positioned in the upper panel may be formed through a separate photolithography process or may be formed together in the same process as a different layer positioned in the upper panel.

Referring toFIG. 29, the liquid crystal display according to an exemplary embodiment of the present disclosure may be a curved display device. That is, the display panel300may include a curved surface that is bent according to at least one direction. The display panel300includes the lower panel100and the upper panel200opposing each other and the liquid crystal layer3positioned therebetween, and the surface of the lower substrate of the lower panel100and the surface of the upper substrate of the upper panel200have substantially the same curved shape.

When the display panel300has the curved shape, in the process of bending the lower panel100and the upper panel200, the pattern of the lower panel100and the pattern of the upper panel200may be misaligned, and a defect may be generated in the adhering state of the above-described sealant. According to an exemplary embodiment of the present disclosure, if the protrusion261is formed in the lower panel100, it may not be necessary to form the cutout for the alignment of the liquid crystal molecules31in the opposed electrode270of the upper panel200such that the display quality defect, such as texturing due to a misalignment between the lower panel100and the upper panel200, may be improved when realizing the curved display panel300. Furthermore, like the above-described exemplary embodiment, when forming the light blocking member221in the lower panel100, the reduction of the aperture ratio due to the misalignment between the lower panel100and the upper panel200may be largely reduced compared with the case in which the light blocking member is positioned in the upper panel200.

According to an exemplary embodiment of the present disclosure, by forming the dams DAM1, DAM2, DAM3, or DAM4, the aligning agent is suppressed from being spread to the region where the sealant310is positioned such that the contact area of the alignment layers11and21and the sealant310is minimized, thereby preventing the adherence deterioration of the sealant310. Accordingly, in the case of the curved display panel300, the adherence of the sealant310is not weakened, thereby lowering the separation possibility of the lower panel100and the upper panel200. Accordingly, by applying an exemplary embodiment of the present disclosure to the curved display panel300, the quality of the display panel300may be further improved.

While the present system and method have been described in connection with what is presently considered to be practical exemplary embodiments, the present system and method are not limited to the disclosed embodiments. On the contrary, the present disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

DESCRIPTION OF SYMBOLS