Substrate and display device having the same

A display device includes a first base substrate, a second base substrate, a liquid crystal layer, a conductive protrusion structure and an electrode structure. The second base substrate is disposed opposite to the first base substrate. The liquid crystal layer is disposed between the first and second base substrates. The conductive protrusion structure is disposed on one of the first and second base substrates. The electrode structure is at least disposed on the first or second base substrate having the conductive protrusion structure.

This application claims the benefit of Taiwan application Serial No. 101122790, filed Jun. 26, 2012, the subject matter of which is incorporated herein by reference.

BACKGROUND

1. Field of the Invention

The invention relates in general to a substrate having a conductive protrusion structure, and more particularly to a display device having the same.

2. Description of the Related Art

Liquid crystal displays (LCDs) are prevalent as display screens of electronic products in the recent years. LCDs are available in various forms including twister nematic, super twisted nematic (STN), in-plane switching (IPS), and multi-domain vertical alignment (MVA).

When applying a voltage to electrodes of an LCD, a rotational direction of liquid crystal molecules can be controlled to modulate a polarization direction of light, such that the intensity of light passing through the liquid crystal molecules is affected to further result in a contrast between a bright state and a dark state to serve as a display image.

To control the direction of liquid crystal molecules, a conventional display based on nematic liquid crystals usually processes surface alignment of a substrate to control alignment of the liquid crystal molecules. For example, the liquid crystals proceed with a rubbing process, in which an alignment film surface applied to a surface of the substrate in contact with the liquid crystals is rubbed. However, such rubbing process not only increases production costs but also reduces the display quality. Moreover, due to a long response time, the foregoing LCD based on nematic liquid crystals is unfavorable in applications for displaying dynamic graphics in sequential colors, and a color filter film is additionally required for presenting display effects of different colors. As a result, production costs and manufacturing complications of LCDs based on nematic liquid crystals are high.

Therefore, blue phase liquid crystals having a fast response speed is one research focus of industrial developers. Blue phase LCDs offer advantages of having a fast response speed, high contrast and a wide viewing angle. Yet, blue phase liquid crystals can only be driven by a higher voltage, which is one of the issues to be overcome in developing blue phase LCD devices.

SUMMARY

The disclosure is directed to a substrate and a display device having the substrate. The substrate includes an electrode structure and a conductive protrusion structure, and is capable of increasing and extending a range of an operating electric field as well as lowering a driving voltage of the display device.

According to an aspect the disclosure, a display device is provided. The display device includes a first base substrate, a second base substrate, a liquid crystal layer, a conductive protrusion structure and an electrode structure. The second base substrate is disposed opposite to the first base substrate. The liquid crystal layer is disposed between the first and second base substrates. The conductive protrusion structure is disposed on one of the first and second base substrates. The electrode structure is disposed on at least one of the first and second base substrates having the conductive protrusion structure.

According to another aspect of the disclosure, a substrate for a liquid crystal display (LCD) device is provided. The substrate includes a base substrate, an electrode structure and a conductive protrusion structure. The conductive protrusion structure is disposed on the base substrate. The electrode structure is disposed on the base substrate, and is adjacent to a liquid crystal layer of the LCD device.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1Ashows a schematic diagram of a display device according to an embodiment of the present invention. Referring toFIG. 1A, a display device10includes a first base substrate110a, a second base substrate110b, an electrode structure150, a conductive protrusion structure160and a liquid crystal layer180. The second base substrate110bis disposed opposite to the first base substrate110a. The electrode structure150is disposed on the first base substrate110ahaving the conductive protrusion structure160. For example, the electrode structure150includes a plurality of alternately arranged pixel electrodes and common electrodes. The conductive protrusion structure160is disposed on the first base substrate110a. In one embodiment, the conductive protrusion structure160may be disposed between the pixel electrodes and common electrodes, or between a pixel electrode and a common electrode (as shown inFIG. 7). The liquid crystal layer180is disposed between the first base substrate110aand the second base substrate110b. The first base substrate110a, the electrode structure150and the conductive protrusion structure160constitute a substrate100.

In an embodiment, the conductive protrusion structure160includes a metal oxide or a carbon nano-material. The carbon nano-material is a group selected from carbon-based nanomaterial, nano carbon fiber and nano carbon graphite. For example, the conductive protrusion structure160may be a group selected from iron oxide, ferric oxide (Fe2O3), titanium dioxide (TiO2), copper oxide (CuO) and indium tin oxide (ITO). In an embodiment, the conductive protrusion structure160includes a plurality of conductive protrusions having a thickness between 10 nm to 1 μm and a length between 100 nm and 10 μm. The conductive protrusions are evenly distributed in a way that the conductive protrusion structure160may have a density of 10−2to 106conductive protrusions per 100 μm2. When a voltage is applied to the electrode structure150, the conductive protrusion structure160being affected by an electric field of the electrode structure150, becomes electrically conductive so that a range of an operating electric field can be extended to provide an expanded effective electric field for more effectively controlling the liquid crystal molecules.

FIG. 1Bshows a top view of the substrate100inFIG. 1A. In this embodiment, for example, the electrode structure150is a semicircular or semi-ellipsoidal cylinder. In other embodiments, the electrode structure150may also be a T-shaped, trapezoidal, semi-spherical, rectangular or multi-layer composite structure. For example, the conductive protrusion structure160includes a plurality of minute rod shaped or pin shaped conductive protrusions evenly or unevenly distributed on an axis of symmetry of the electrode structure150to provide point discharge. In other embodiments, the conductive protrusion structure160may also be a hair shaped, forked shaped, needle shaped or column shaped structure. When applying a voltage to the electrode structure150, the conductive protrusion structure160is capable of extending the operating electric field and reducing a range of a dead zone. A dead zone means an insufficient electric which is too weak to drive the liquid crystal molecules. The shape and position of the conductive protrusion structure160may be adjusted to adapt to manufacturing or product requirements.

FIG. 2shows a sectional view of a display device20according to an embodiment of the present invention. As shown inFIG. 2, the display device20includes a first base substrate210a, a second base substrate210b, an electrode structure250, a conductive protrusion structure260and a liquid crystal layer280. The second base substrate210bis disposed opposite to the first base substrate210a. The electrode structure250includes a first electrode230, an insulation layer235and a second electrode240. The first electrode230is disposed on the first base substrate210a. The insulation layer235is disposed on the first electrode230. The second electrode240is disposed on the insulation layer235. The conductive protrusion structure260is disposed on the second electrode240. In this embodiment, for example, the length, density and material of the conductive protrusion structure260is substantially equal to those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein.

In this embodiment, the first base substrate210a, the insulation layer235, the electrode structure250and the conductive protrusion structure260constitute a substrate200. InFIG. 2, the conductive protrusion structure260is depicted as being disposed on the axis of symmetry of the second electrode240, and may, however, be disposed at other positions of the second electrode240. Alternatively, the conductive protrusion structure260may also be disposed between two second electrodes240on the insulation layer235. By applying voltages having different polarities to the two adjacent second electrodes240, the two sides of the conductive protrusion structure260may carry electricity having different polarities as being induced by the second electrodes240to improve the intensity of the local electric field.

FIG. 3shows a sectional view of a display device30according to an embodiment of the present invention. The display device30includes a first base substrate310a, a second base substrate310b, an electrode structure350a, an electrode structure350b, a conductive protrusion structure360a, a conductive protrusion structure360band a liquid crystal layer380. The second base substrate310bis disposed opposite to the first base substrate310a. The electrode structure350includes the first electrode350aand the second electrode350b. The first electrode350ais disposed on the first base substrate310a, and the second electrode350bis disposed on the second base substrate310b. The conductive protrusion structure360ais disposed on the second electrode350a, and the conductive protrusion structure360bis disposed on the second electrode350b.

In this embodiment, the conductive protrusion structures360aand360bhave substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein. The first base substrate310a, the electrode structure350aand the conductive protrusion structure360aconstitute a substrate300a; the second base substrate310b, the electrode structure350band the conductive protrusion structure360bconstitute a substrate300b. The substrates300aand300bmay have similar structures and be arranged in a symmetrical manner. In other embodiments, the substrates300aand300bmay have different structures and be arranged in a non-symmetrical manner. For example, the conductive protrusion structure may be disposed at one of the substrate, e.g., only one of the substrates300aand300bis disposed with the conductive protrusion structure. That is to say, the conductive protrusion structure360aor the conductive protrusion structure360bmay be disposed on at least one of the electrode structure350aof the substrate300aand the electrode structure350bof the substrate300b.

InFIG. 3, the conductive protrusion structures360aand360bare depicted as respectively being disposed on the axes of symmetry of the electrode structures350aand350b. Given that the operating electric field of the electrode structures350aand350bcan be extended by the conductive protrusion structures360aand360b, the conductive protrusion structures360aand360bmay be disposed at other positions of the electrode structure350aand the electrode structure350b.

FIG. 4shows a sectional view of a display device40according to an embodiment of the present invention. As shown inFIG. 4, the display device40includes a first base substrate410a, a second base substrate410b, an electrode structure450a, an electrode structure450b, a conductive protrusion structure460a, a conductive protrusion structure460band a liquid crystal layer480. The second base substrate410bis disposed opposite to the first base substrate410a. The electrode450aincludes a first electrode430a, an insulation layer435aand a second electrode440a. The first electrode430ais disposed on the first base substrate410a. The insulation layer435ais disposed on the first electrode430a. The second electrode440ais disposed on the insulation layer435a. The conductive protrusion structure460ais disposed on the second electrode440a. The electrode structure450bincludes a first electrode430b, an insulation layer435band a second electrode440b. The first electrode430bis disposed on the second base substrate410b. The insulation layer435bis disposed on the first electrode430b. The second electrode440bis disposed on the insulation layer435b. The conductive protrusion structure460bis disposed on the second electrode440b.

In this embodiment, the conductive protrusion structures460aand460bhave substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein. The first base substrate410a, the insulation layer435a, the electrode structure450aand the conductive protrusion structure460aconstitute a substrate400a. The second base substrate410b, the insulation layer435b, the electrode structure450band the conductive protrusion structure460bconstitute a substrate400b. InFIG. 4, the conductive protrusion structures460aand460bare respectively disposed on the axes of symmetry of the electrode structures450aand450b. However, the conductive protrusion structures460aand460bmay also be disposed at other positions of the electrode structures450aand450b. Alternatively, the conductive protrusion structure460aor the conductive protrusion structure460bmay also be disposed between two electrode structures450aon the insulation layer435aor two electrode structures450bon the insulation layer435b. By applying voltages having different polarities to the two adjacent electrode structures450aor electrode structures450b, the two sides of the conductive protrusion structure460aor the conductive protrusion structure460bmay carry electricity having different polarities as being induced by the electrode structures450aor the electrode structures450bto improve the intensity of the local electric field.

FIG. 5shows a sectional view of a display device50according to an embodiment of the present invention. The display device50includes a first base substrate510a, a second base substrate510b, an electrode structure550, a conductive protrusion structure560a, a conductive protrusion structure560band a liquid crystal layer580. The first base substrate510ais disposed opposite to the first base substrate510a. The electrode structure550includes a first electrode550aand a second electrode550b. The first electrode550ais disposed on the first base substrate510a, and the second electrode550bis disposed on the second base substrate510. The conductive protrusion structures560aand560bare respectively disposed on the second electrodes550aand550b.

In this embodiment, the conductive protrusion structures560aand560bhave substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein. The first base substrate510a, the first electrode550aand the conductive protrusion structure560aconstitute a substrate500a. The second base substrate510b, the second electrode550band the conductive protrusion structure560bconstitute a substrate500b.

In this embodiment, the structure of the substrate500aand the structure of the substrate500bmay be the same or different. That is, the conductive protrusion structure may be disposed at only one of the substrate. More specifically, the conductive protrusion structure560aor the conductive protrusion structure560bis disposed on at least one of the first electrode550aof the substrate500aor the second electrode550bof the substrate500b. Further, the conductive protrusion structures560aand560bmay be respectively disposed on the axes of symmetry of the electrode structures550aand550b. Given that the intensity of local electric field of the electrode structure550can be extended by the conductive protrusion structures560aand560b, the conductive protrusion structures560aand560bmay be disposed at other positions of the first electrode550aand the second electrode550b.

FIG. 6shows a sectional view of a display device60according to an embodiment of the present invention. As shown inFIG. 6, the display device60includes a first base substrate610a, a second base substrate610b, an electrode structure650a, an electrode structure650b, a conductive protrusion structure660a, a conductive protrusion structure660band a liquid crystal layer680. The second base substrate610bis disposed opposite to the first base substrate610a. The electrode structure650aincludes a first electrode630a, an insulation layer635aand a second electrode640a. The first electrode630ais disposed on the first base substrate610a. The insulation layer635ais disposed on the first electrode630a. The second electrode640ais disposed on the insulation layer635a. The conductive protrusion structure660ais disposed on the second electrode layer640a. The electrode structure650bincludes a first electrode630b, an insulation layer635band a second electrode640b. The first electrode630bis disposed on the second base substrate610b. The insulation layer635bis disposed on the first electrode630b. The second electrode640bis disposed on the insulation layer635b. The conductive protrusion structure660bis disposed on the second electrode640b.

In this embodiment, the conductive protrusion structures660aand660bhave substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein. The first base substrate610a, the insulation layer635a, the electrode structure650aand the conductive protrusion structure660aconstitute a substrate600a. The second base substrate610b, the insulation layer635b, the electrode structure650band the conductive protrusion structure660bconstitute a substrate600b. InFIG. 6, the conductive protrusion structures660aand660bare respectively disposed on the axes of symmetry of the electrode structures650aand650b. However, the conductive protrusion structures660aand660bmay be disposed at other positions of the electrode structures650aand650b. Alternatively, the conductive protrusion structure660aor the conductive protrusion structure660bmay also be disposed between two electrode structures650aon the insulation layer635aor two electrode structures650bon the insulation layer635b. By applying voltages having different polarities to the two adjacent electrode structures650aor electrode structures650b, the two sides of the conductive protrusion structure660aor the conductive protrusion structure660bmay carry electricity having different polarities as being induced by the electrode structures650aor the electrode structures650b, to improve the intensity of the local electric field.

FIG. 7shows a sectional view of a display device70according to an embodiment of the present invention. The display device70includes a first base substrate710a, a second base substrate710b, an electrode structure750, a conductive protrusion structure760and a liquid crystal layer780. The second base substrate710bis disposed opposite to the first base substrate710a. The electrode structure750is disposed on the first base substrate710ahaving the conductive protrusion structure760thereon. For example, the electrode structure750includes a plurality of alternately arranged pixel electrodes and common electrodes. The conductive protrusion structure760is disposed on the first base substrate710aand disposed between the two adjacent electrode structures750. For example, the two adjacent electrode structures750are a pixel electrode and a common electrode. The liquid crystal layer780is disposed between the first base substrate710aand the second base substrate710b. The first base substrate710a, the electrode structure750and the conductive protrusion structure760constitute a substrate700. In this embodiment, for example, the conductive protrusion structure760has substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein.

FIG. 8shows a sectional view of a display device80according to an embodiment of the present invention. The display device80includes a first base substrate810a, a second base substrate810b, an electrode structure850, a conductive protrusion structure860and a liquid crystal layer880. The second base structure substrate810bis disposed opposite to the first base substrate810a. The electrode structure850is disposed on the first base substrate810ahaving the conductive protrusion structure860thereon. For example, the electrode structure850includes a plurality of alternately arranged pixel electrodes and common electrodes. The conductive protrusion structure860is disposed at an edge of the electrode structure850. For example, the two adjacent electrode structures850are a pixel electrode and a common electrode. The liquid crystal layer880is disposed between the first base substrate810aand the second base substrate810b. The first base substrate810a, the electrode structure850and the conductive protrusion structure860constitute a substrate800. In this embodiment, for example, the conductive protrusion structure860has substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein.

FIG. 9shows a sectional view of a display device90according to an embodiment of the present invention. The display device90includes a first base substrate910a, a second base substrate910b, an electrode structure950, a conductive protrusion structure960and a liquid crystal layer980. The liquid crystal layer980is disposed between the first base substrate910aand the second base substrate910b. The second base substrate910bis disposed opposite to the first base substrate910a. The electrode structure950is disposed on the first base substrate910ahaving the conductive protrusion structure960thereon. For example, the electrode structure950includes a plurality of alternately arranged second electrodes940, an insulation layer935and a first electrode930. For example, the first electrode930and the second electrode940are one of pixel electrodes or common electrodes. The conductive protrusion structure960is disposed on a non-electrode region between two adjacent electrode structures950, and may be disposed on a surface of the first base substrate910a. For example, two adjacent electrode structures950may be a pixel electrode and a common electrode.

The first base substrate910a, the electrode structure950and the conductive protrusion structure960constitute a substrate900. In this embodiment, for example, the conductive protrusion structure960has substantially the same length, density and material as those of the conductive protrusion structure160inFIGS. 1A and 1B, and associated details shall be omitted herein. By applying voltages having different polarities to the two adjacent electrode structures950, the two sides of the conductive protrusion structure960may carry electricity having different polarities as being induced by the electrode structures950, to improve the intensity of the local electric field.

FIG. 10Ashows a sectional view of a substrate1000according to an embodiment of the present invention. As shown inFIG. 10A, the substrate1000includes a base substrate1010, electrode structures1050and conductive protrusion structures1060.FIG. 10Bshows a top view of the substrate1000inFIG. 10A. The substrate1000is similar to the substrate100inFIG. 1A, with a main difference being that the electrode structures1050of the substrate1000are rectangular bodies. The substrate1000may replace the substrates at either side of the display devices10to90inFIGS. 1A,1B,2to9.

FIG. 11Ashows a sectional view of a substrate1100according to an embodiment of the present invention. As shown inFIG. 11A, the substrate1100includes a base substrate1110, electrode structures1150and conductive protrusion structures1160.FIG. 11Bshows a top view of the substrate1100inFIG. 11A. The substrate1100is similar to the substrate100inFIG. 1A, with a main difference being that conductive protrusion structures1160of the substrate1100are disposed at two sides of the electrode structure1150. Thus, an issue of a dead zone of an electric field after applying a voltage can be solved. The conductive protrusion structures1160may be evenly or unevenly distributed, and may be arranged in a symmetrical or unsymmetrical manner at two sides of the electrode structures1150to adapt to manufacturing or product requirements. The substrate1100may substitute for the substrate at either side of the display device10,20,30,40,50,60,70,80or90inFIGS. 1A,1B,2to9, respectively.

FIG. 12Ashows a sectional view of a substrate1200according to an embodiment of the present invention. As shown inFIG. 12A, the substrate1200includes a base substrate1210, electrode structures1250and conductive protrusion structures1260.FIG. 12Bshows a top view of the substrate1200inFIG. 12A. The substrate1200is similar to the substrate1000inFIG. 10A, with a main difference being that the conductive protrusion structures1260of the substrate1200are disposed at two sides of the electrode structures1250to solve an issue of a dead zone of an electric field after applying a voltage.

In this embodiment, a distance X is between the conductive protrusion structure1260and an edge of the electrode structure1250, and the distance X ranges between 10 nm and 10 μm. A gap P1is between two rows of conductive protrusion structures1260, and the gap P1ranges between 0.01 μm and 20 μm. A gap P2is between every two conductive protrusion structures1260of the same row, and the gap P2ranges between 0.01 μm and 20 μm. In an embodiment, the conductive protrusion structures1260may be evenly or unevenly distributed, and the conductive protrusion structures1260may be arranged in a symmetrical or unsymmetrical manner at two sides of the electrode structure1250to adapt to manufacturing or product requirements. The substrate1200may substitute for the substrate at either side of the display device10,20,30,40,50,60,70,80or90inFIGS. 1A,1B,2to9, respectively.

FIGS. 13 to 19show schematic diagrams of an electrode structure and conductive protrusion structures according to different embodiments of the present invention. Referring toFIG. 13, for example, a cross-section of the electrode structure1350is semi-circle shaped, and a plurality of conductive protrusion structures1360may be disposed on a surface of the electrode structure1350. In this embodiment, three rows of conductive protrusion structures1360disposed on the electrode structure1350are taken as an example. In other embodiments, more or fewer rows of conductive protrusion structures1360may be arranged on the electrode structure1350in an uneven and unsymmetrical manner to adapt to manufacturing and product requirements.

Referring toFIG. 14, in an embodiment, a cross-section of an electrode structure1450may be a trapezoid, and a plurality of conductive protrusion structures1460may be disposed on a surface of the electrode structure1450. Referring toFIG. 15, in an embodiment, a cross-section of an electrode structure1550may be rectangle or square shaped, and a plurality of conductive protrusion structures1560may be disposed on a surface of the electrode structure1550. Referring toFIG. 16, in an embodiment, a cross-section of an electrode structure1650may be a layer-stacked structure, and a plurality of conductive protrusion structures1660may be disposed on a surface of the electrode structure1650. InFIGS. 14 to 16, the electrode structures1450to1650evenly arranged with three rows of conductive protrusion structures1460to1660are taken as examples. In other embodiments, more or fewer rows of conductive protrusion structures1460to1660may be arranged in an uneven and unsymmetrical manner on the electrode structures1450to1640electrode structures to adapt to manufacturing and product requirements.

Referring toFIG. 17, in an embodiment, a cross-section of an electrode structure1750may be a layer-stacked structure (not shown), and a plurality of conductive protrusion structures1760may be provided on a surface of the electrode structure1750. Referring toFIG. 18, in an embodiment, a cross-section of an electrode structure1850may be triangular shaped, and a plurality of conductive protrusion structures1860may be disposed on a surface of the electrode structure1850. InFIGS. 17 and 18, the electrode structures1750and1850with two rows of conductive protrusion structures1760and1860arranged in an unsymmetrical or symmetrical manner are taken as examples. In other embodiments, more or fewer rows of conductive protrusion structures1760and1860may be evenly or unevenly arranged in a symmetrical manner on the electrode structures1750and1850to adapt to manufacturing and product requirements.

In an embodiment, a cross-section of an electrode structure1950may be T-shaped, and a plurality of conductive protrusion structures1960may be disposed on a surface of the electrode structure1950. InFIG. 19, the electrode structure1960with a single row of conductive protrusion structures1960is taken as an example. In other embodiments, more or fewer rows of conductive protrusion structures1960may be evenly or unevenly arranged in a symmetrical manner on the electrode structure1950to adapt to manufacturing and product requirements.

FIGS. 20A to 20Eshow schematic diagrams of a conductive protrusion structure according to different embodiments of the present invention. Referring toFIG. 20A, a conductive protrusion structure2060amay be polygonal cylinder shaped, e.g., hexagonal cylinder shaped inFIG. 20A. Referring toFIG. 20B, a conductive protrusion structure2060bmay be a rod shaped structure having a spiral top end. Referring toFIG. 20C, a conductive protrusion structure2060cmay be a forked shape. Referring toFIG. 20D, a conductive protrusion structure2060dmay be a semicircular cylinder. Referring toFIG. 20E, a conductive protrusion structure2060emay be column shaped (e.g., a carbon column) having a plurality of outwardly extending minute branches (e.g., zinc oxide). In an embodiment, the conductive protrusion structure may be a hair shaped or a pin shaped structure.

In summary, a substrate and a display device having such substrate are provided as described by the above embodiments of the present invention. Through arrangements of electrode structures and conductive protrusion structures, a part of an electric field is effectively reinforced to lower a driving voltage of the display device. An issue of a dead zone of an electric field is further mitigated by disposing the conductive protrusion structures on a surface of the electrode structures. Thus, without additionally increasing the driving voltage, a more uniform electric field having greater intensity and a higher density is provided to thus expand and extend a range of an operating electric field as well as to lower the driving voltage.