Polarizing member and display device having the same

A polarizing member includes a base layer, a first reflection preventing layer and a second reflection preventing layer. A base layer polarizes light, generating polarized light. A first reflection preventing layer is disposed on the base layer, diffusing the polarized light and generating first diffused light. A second reflection is disposed on the first reflection preventing layer, diffusing the first diffused light and generating second diffused light.

TECHNICAL FIELD

The present invention relates to a polarizing member and a display device having the same.

DESCRIPTION OF RELATED ART

Liquid crystal display (LCD) devices include an anti-glare (AG)-treated layer to reduce eye strain and fatigue that may be caused by surface reflections. The AG-treated layer may be formed of a reflection preventing layer containing silica particles to diffuse light. Accordingly, light reflected from a panel of the LCD devices may be prevented from being incident into the eyes of a user.

However, the reflection preventing layer may cause optical interference with the LCD panel to create a sparkle phenomenon, a distortion of an image. For example, if silica particles are located at the boundary between two adjacent pixels, refraction of light by the silica particles may distort an image displayed by the LCD devices.

SUMMARY

According to an exemplary embodiment of the present invention, a polarizing member includes a base layer, a first reflection preventing layer and a second reflection preventing layer. A base layer polarizes light, generating polarized light. A first reflection preventing layer is disposed on the base layer, diffusing the polarized light and generating first diffused light. A second reflection is disposed on the first reflection preventing layer, diffusing the first diffused light and generating second diffused light.

According to an exemplary embodiment of the present invention, a display device includes a backlight assembly, a display panel, a first polarizing member and a second polarizing member. A backlight assembly generates first light. A display panel emits second light, having a first surface and a second surface and generating an image through the first surface. A first polarizing member is disposed on the first surface of the display panel, polarizing the second light. A second polarizing member is disposed on the second surface of the display panel, polarizing the first light and generating the second light. The second polarizing member is formed of the polarizing member.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the thickness of layers and regions may be exaggerated for clarity. It will also be understood that when an element is referred to as being “on” another element or substrate, it may be directly on the other element substrate, or intervening layers may also be present. It will also be understood that when an element is referred to as being “coupled to” or “connected to” another element, it may be directly coupled to or connected to the other element, or intervening elements may also be present. Like reference numerals may refer to the like elements throughout the specification and drawings.

For the convenience of description, it is assumed that a display device is a liquid crystal display (LCD) device, but the present invention is not limited thereto. For example, the present invention is also applicable to various other display devices such as an electrophoretic display device, an organic light-emitting display device, an inorganic electroluminescent display device, a field emission display (FED) device, a surface-conduction electron-emitter display device, a plasma display device, and a cathode ray tube display device.

FIG. 1is a cross-sectional view of an LCD device according to an exemplary embodiment of the present invention.

Referring toFIG. 1, an LCD device10includes an LCD panel.200, which has a first surface and a second surface and displays an image with the use of light, a first polarizing plate100, which is disposed on the first surface of the LCD panel200, a second polarizing plate300, which is disposed on the second surface of the LCD panel200, and a backlight assembly400, which provides light to the LCD panel200.

The LCD panel200includes an array substrate210, an opposing substrate220, which faces, and is coupled to, the array substrate210, a liquid crystal layer230, which is interposed between the array substrate210and the opposing substrate220, and a sealant240, which couples the array substrate210and the opposing substrate220together.

The array substrate210includes a first base substrate212including a plurality of pixel regions, a plurality of thin-film transistors213formed in the pixel regions, respectively, a plurality of pixel electrodes214formed in the pixel regions, respectively, and electrically connected to the TFTs213, and an insulating layer215formed on the first base substrate212and covers the TFTs213.

The opposing substrate220is disposed above the array substrate210. The opposing substrate220includes a second base substrate221, a color filter layer222, which is disposed on the bottom of the second base substrate212and realizes predetermined colors with the use of light, and a common electrode223, which is formed on the color filter layer222and outputs a common voltage. The liquid crystal layer230may adjust the transmittance of light L provided by the backlight assembly400according to an electric field formed between the pixel electrodes214and the common electrode223.

The second polarizing plate300is disposed between the LCD panel200and the backlight assembly400. The second polarizing plate300may polarize the light L, which is emitted from the backlight assembly400, and may provide the polarized light to the LCD panel200.

The first polarizing plate100may polarize and emit light emitted from the LCD panel200in a direction perpendicular to a direction in which the second polarizing plate300polarizes light. The structure of the first polarizing plate100will hereinafter be described.

FIG. 2is a perspective view of the first polarizing plate of the LCD device10ofFIG. 1, andFIG. 3is a cross-sectional view taken along line III-III′ ofFIG. 2.

Referring toFIGS. 2 and 3, the first polarizing plate100of the LCD device10may be a rectangular optical sheet, but the present invention is not limited thereto.

The first polarizing plate100includes a base layer110, a first protective layer120, a second protective layer130, a first reflection preventing layer140, a second reflection preventing layer150, a first adhesive layer160and a second adhesive layer170.

The base layer110has a transmission axis for transmitting light therethrough. The base layer110may polarize linearly light incident thereupon from the outside in a direction of the transmission axis. The base layer110may be a polyvinyl alcohol (PVA)-based film with a dichroic dye absorbed and oriented therein, but the invention is not limited thereto. The base layer110may have a thickness of about 5 μm to about 40 μm.

The first protective layer120and the second protective layer130may serve to protect the base layer110. The first protective layer120has a first surface and a second surface, and is disposed above the base layer110to face the base layer110. The second protective layer130is disposed below the base layer110. The first protective layer120and the second protective layer130may be formed of a material with non-optical properties, so the protective layers120and130do not change a polarization state of light polarized by the base layer110.

For example, the first protective layer120and the second protective layer130include films containing a thermoplastic resin, for example, a polyester-based resin such as polyethylene terephthalate, polyethylene isophthalate, or polybutylene terephthalate, a cellulose-based resin such as diacetyl cellulose or triacetyl cellulose, a polycarbonate-based resin, an acrylic-based resin such as polymethyl methacrylate or polyethyl methacrylate, a styrene-based resin such as polystyrene or an acrylonitrile-styrene copolymer, polyethylene, polypropylene, a polyolefin resin with a cyclo or norbornene structure, a polyolefin-based resin such as an ethylene propylene copolymer, a vinyl chloride-based resin, nylon, a polyamide-based resin such as aromatic polyamide, an imide-based resin, a polyethersulfone-based resin, a sulfone-based resin, a polyether ketone-based resin, a polyphenylene sulfide-based resin, a vinyl alcohol-based resin, a vinylidene chloride-based resin, a vinyl butyral-based resin, an allyl acrylate-based resin, a polyoxymethylene-based resin, or an epoxy-based resin, or a blend of the thermoplastic resin. The first protective layer120and the second protective layer130may also include films containing a thermally curable resin such as a methacrylic-based resin, a urethane-based resin, an epoxy-based resin or a silicon-based resin, or a ultraviolet (UV) curable resin.

The first protective layer120and the second protective layer130may have a thickness of about 1 μm to about 500 μm.

The second protective layer130may be formed of a film having a phase compensation function. For example, the second protective layer130may include a functional film such as a phase compensation film in the upper portion of the second protective layer130.

The first reflection preventing layer140, which primarily diffuses light emitted from the base layer110, is disposed on the first surface of the first protective layer120that faces the base layer110. For example, the first reflective preventing layer140is disposed on the bottom surface of the first protective layer120above the base layer110, as illustrated inFIG. 3. Even though not specifically illustrated inFIG. 3, the first reflection preventing layer140may be formed of a reflection preventing composition to have, for example, surface irregularities, or may be formed of a binder layer having a binder and a plurality of beads scattered in the binder to diffuse light.

The second reflection preventing layer150, which secondarily diffuses the light emitted from the base layer110, is disposed on the second surface of the first protective layer120. For example, the second reflection preventing layer150is disposed on the top surface of the first protective layer120, as illustrated inFIG. 3. The second reflection preventing layer150is an outer surface of the display device10, but the present invention is not limited thereto. Even though not specifically illustrated inFIG. 3, the second reflection preventing layer150may be formed of a reflection preventing composition to have, for example, surface irregularities, or may be formed of a binder layer having a binder and a plurality of beads scattered in the binder to diffuse light.

The first reflection preventing layer140and the second reflection preventing layer150are in contact with, or attached onto, the top and the bottom, respectively, of the first protective film120, but the present invention is not limited thereto.

In the display device10, light emitted from the base layer110is diffused first by the first reflection preventing layer140and then by the second reflection preventing layer150. Since the light emitted from the base layer110is diffused twice, the occurrence of a sparkle phenomenon, i.e., a distortion of an image caused by optical interference, may be prevented.

The structures of the first reflection preventing layer140and the second reflection preventing layer150will hereinafter be described.

The first adhesive layer160is attached onto the top surface of the base layer110, and may fix the first protective layer120, which is disposed between the first reflection preventing layer140and the second reflection preventing layer150, to the base layer110.

The first adhesive layer160may have a different refractive index from the first reflection preventing layer140. For example, the refractive index of the first adhesive layer160is smaller than the refractive index of the first reflection preventing layer140. Due to the difference in the refractive indexes of the first adhesive layer160and the first reflection preventing layer140, an optical path difference is generated upon the primary diffusion of light emitted from the base layer110, and as a result, the occurrence of a sparkle phenomenon, which is a distortion of an image caused by optical interference, may be effectively prevented.

The second adhesive layer170is attached onto the top surface of the second base substrate221, and may fix the first polarizing plate100to the LCD panel200. Even though not specifically illustrated inFIG. 1, an adhesive layer may be provided in the second polarizing plate300, and may thus attach the second polarizing plate onto the first base substrate212.

The structures of the first reflection preventing layer140and the second reflection preventing layer150will hereinafter be described.

Each of the first reflection preventing layer140and the second reflection preventing layer150is configured to have surface irregularities. The surface irregularities may be of an embossed type or an engraved type. Surface irregularities of the embossed type may be patterns that protrude from a surface, and surface irregularities of the engraved type may be patterns that are recessed from a surface. The patterns may be regular, but the present invention is not limited thereto.

FIG. 4is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to an exemplary embodiment of the present invention.

Referring toFIG. 4, a first polarizing plate100aincludes a first reflection preventing layer140a, which is disposed on the bottom of a first protective layer120, and a second reflection preventing layer150a, which is disposed on the top of the first protective layer120.

The first reflection preventing layer140amay have surface irregularities. For example, the first reflection preventing layer140ahas an embossed or corrugated surface. The second reflection preventing layer150amay also have surface irregularities. For example, the second reflection preventing layer150ahas an embossed or corrugated surface.

The surface irregularities on the first reflection preventing layer140aand/or the second reflection preventing layer150amay have a uniform size, but the present invention is not limited thereto. The surface irregularities on the first reflection preventing layer140aand/or the second reflection preventing layer150amay be formed as semicircular or hemispherical protrusions, but the present invention is not limited thereto.

A first adhesive layer160may have surface irregularities of the engraved type to be properly coupled to the first reflection preventing layer140a, which have surface irregularities of the embossed type.

A base layer110, the first protective layer120, a second protective layer130, and a second adhesive layer170ofFIG. 4are substantially identical to their respective counterparts ofFIG. 3, and thus, detailed descriptions thereof will be omitted.

FIG. 5is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to an exemplary embodiment of the present invention.

A first polarizing plate100bofFIG. 5is substantially the same as the first polarizing plate100aofFIG. 4except for the structures of a first reflection preventing layer140b, a second reflection preventing layer150band a first adhesive layer160, and thus will hereinafter be described, focusing mainly on the first reflection preventing layer140b, the second reflection preventing layer150band the first adhesive layer160.

Referring toFIG. 5, the first reflection preventing layer140bmay have surface irregularities of the engraved type, and the second reflection preventing layer150bmay also have surface irregularities of the engraved type.

The surface irregularities on the first reflection preventing layer140band/or the second reflection preventing layer150bmay have a uniform size, but the present invention is not limited thereto. The surface irregularities on the first reflection preventing layer140band/or the second reflection preventing layer150bmay be formed as angular recesses with a predetermined depth, but the present invention is not limited thereto.

The first adhesive layer160may have surface irregularities of the embossed type to be properly coupled to the first reflection preventing layer140b, which have surface irregularities of the engraved type.

FIGS. 6 and 7are partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of first polarizing plates of display devices according to exemplary embodiments of the present invention.

A first polarizing plate100cofFIG. 6is substantially the same as the first polarizing plate100aofFIG. 4except for the structure of a first reflection preventing layer140c, and thus hereinafter be described, focusing mainly on the first reflection preventing layer140c.

Referring toFIG. 6, the first reflection preventing layer140chas surface irregularities of the engraved type, and the second reflection preventing layer150chas surface irregularities of the embossed type.

A first adhesive layer160has surface irregularities of the embossed type to be properly coupled to the first reflection preventing layer140c, which has surface irregularities of the engraved type.

A first polarizing plate100dofFIG. 7is substantially the same as the first polarizing plate100aofFIG. 4except for the structure of a second reflection preventing layer150d, and thus will hereinafter be described, focusing mainly on the second reflection preventing layer150d.

Referring toFIG. 7, the second reflection preventing layer150dhas surface irregularities of the engraved type, and a first reflection preventing layer140dhas surface irregularities of the embossed type.

Each of the first reflection preventing layer140and the second reflection preventing layer150may have surface irregularities of the embossed type or the engraved type, as described above with reference toFIGS. 4 to 7, but the invention is not limited thereto. For example, each of the first reflection preventing layer140and the second reflection preventing layer150may be formed of a binder and a plurality of beads scattered in the binder to diffuse light.

FIG. 8is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to an exemplary embodiment of the present invention.

A first polarizing plate100eofFIG. 8is substantially the same as the first polarizing plate100aofFIG. 4except for the structures of a first reflection preventing layer140eand a second reflection preventing layer150e, and thus will hereinafter be described, focusing mainly on the first reflection preventing layer140eand the second reflection preventing layer150e.

Referring toFIG. 8, the first reflection preventing layer140eis disposed on the bottom of a first protective layer120and is formed of a binder140e-1and a plurality of beads140e-2scattered in the binder140e-1to diffuse light. The beads140e-2may have a uniform size and have the same refractive index, but the present invention is not limited thereto. Each of the beads140e-2may have a different refractive index from the binder140e-1.

The second reflection preventing layer150eis disposed at the top of the first protective layer120, and is formed of a binder150e-1and a plurality of beads150e-2scattered in the binder150e-1to diffuse light. The heads150e-2may have a uniform size and have the same refractive index, but the invention is not limited thereto. Each of the heads150e-2may have a different refractive index from the binder150e-1.

In the first polarizing plate100e, light emitted from a base layer110is diffused first by the beads140e-2included in the first reflection preventing layer140eand then by the beads150e-2included in the second reflection preventing layer150e. Since the light emitted from the base layer110is diffused twice, the occurrence of a sparkle phenomenon, which is a distortion of an image caused by optical interference, may be prevented.

Since the first reflection preventing layer140eis formed in a flat shape, a first adhesive layer160may also be formed in a flat shape to be properly coupled to the first reflection preventing layer140e.

Each of the first reflection preventing layer140eand the second reflection preventing layer150eis formed of a binder layer including a binder and a plurality of beads scattered in the binder to diffuse light, as described above with reference toFIG. 8, but the present invention is not limited thereto. For example, one of the first reflection preventing layer140and the second reflection preventing layer150may have surface irregularities of the embossed type or the engraved type, and the other reflection preventing layer may be formed of a binder layer including a binder and a plurality of beads scattered in the binder to diffuse light.

FIGS. 9 and 10are partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of first polarizing plates of display devices according to exemplary embodiments of the present invention.

A first polarizing plate100fofFIG. 9is substantially the same as the first polarizing plate100eofFIG. 8except for the structure of a second reflection preventing layer150f, and thus will hereinafter be described, focusing mainly on the second reflection preventing layer150f.

Referring toFIG. 9, the first polarizing plate100fincludes the second reflection preventing layer150f, which is disposed on the top of a first protective layer120and has surface irregularities of the embossed type. A first reflection preventing layer140fis disposed on the bottom of the first protective layer120and includes a binder140f-1and a plurality of beads140f-2scattered in the binder140f-1to diffuse light.

The second reflection preventing layer150fis illustrated inFIG. 9as having surface irregularities of the embossed type, but the present invention is not limited thereto. For example, the second reflection preventing layer150fhas surface irregularities of the engraved type.

A first polarizing plate100gofFIG. 10is substantially the same as the first polarizing plate100eofFIG. 8except for the structure of a first reflection preventing layer140g, and thus will hereinafter be described, focusing mainly on the first reflection preventing layer140g.

Referring toFIG. 10, the first polarizing plate100gincludes the first reflection preventing layer140g, which is disposed on the bottom of a first protective layer120and has surface irregularities of the embossed type. A second reflection preventing layer150gis disposed on the top of the first protective layer120and includes a binder150g-4and a plurality of beads150g-2scattered in the binder150g-1to diffuse light.

The first reflection preventing layer140gis illustrated inFIG. 10as having surface irregularities of the embossed type, but the present invention is not limited thereto. For example, the first reflection preventing layer140ghas surface irregularities of the engraved type.

In an exemplary embodiment, at least one of a first reflection preventing layer and a second reflection preventing layer may be formed of a binder layer including a binder and a plurality of beads scattered in the binder to diffuse light, as described above with reference toFIGS. 8 to 10, but the invention is not limited thereto. For example, at least one of a first reflection preventing layer and a second reflection preventing layer may be formed of a binder layer with surface irregularities.

FIG. 11is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to an exemplary embodiment of the present invention.

A first polarizing plate100hofFIG. 11is substantially the same as the first polarizing plate100eofFIG. 8except for the structures of a first reflection preventing layer140hand a second reflection preventing layer150h, and thus will hereinafter be described, focusing mainly on the first reflection preventing layer140hand the second reflection preventing layer150h.

Referring toFIG. 11, the first reflection preventing layer140his disposed on the bottom of a first protective layer120and is formed of a binder140h-1and a plurality of beads140h-2scattered in the binder140h-1to diffuse light. The first reflection preventing layer140hhas surface irregularities.

The second reflection preventing layer150his disposed on the top of the first protective layer120and is formed of a binder150h-1and a plurality of beads150h-2scattered in the binder150h-1to diffuse light. The second reflection preventing layer150hhas surface irregularities.

Each of the first reflection preventing layer140hand the second reflection preventing layer150hhas surface irregularities of the embossed type, but the present invention is not limited thereto. For example, each of the first reflection preventing layer140hand the second reflection preventing layer150hmay have surface irregularities of the engraved type.

Since the first reflection preventing layer140hhas surface irregularities, a first adhesive layer160also has surface irregularities to be properly coupled to the first reflection preventing layer140h.

Each of the first reflection preventing layer140hand the second reflection preventing layer150hofFIG. 11is formed of a binder layer with surface irregularities, but the present invention is not limited thereto. For example, one of the first reflection preventing layer140hand the second reflection preventing layer150hmay be formed of a binder layer with surface irregularities, and the other reflection preventing layer may have surface irregularities of the embossed type or the engraved type.

FIG. 12is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to another exemplary embodiment of the invention.

A first polarizing plate100iofFIG. 12is substantially the same as the first polarizing plate100hofFIG. 11except for the structure of a second reflection preventing layer150i, and thus will hereinafter be described, focusing mainly on the first reflection preventing layer150i.

Referring toFIG. 12, the second reflection preventing layer150iis disposed on the top of a first protective layer120and has surface irregularities of the embossed type. Alternatively, the second reflection preventing layer150imay have surface irregularities of the engraved type.

A first reflection preventing layer140iis disposed on the bottom of the first protective layer120, and is formed of a binder140i-1and a plurality of beads140i-2scattered in the binder140i-1to diffuse light. The first reflection preventing layer140ihas surface irregularities.

InFIG. 12, the first reflection preventing layer140ihas surface irregularities, and the second reflection preventing layer150ihas a non-binder layer with surface irregularities. However, the present invention is not limited thereto. For example, the first reflection preventing layer140imay be formed of a non-binder layer with surface irregularities, and the second reflection preventing layer150imay be formed of a binder layer with surface irregularities.

In exemplary embodiments, one of a first reflection preventing layer and a second reflection preventing layer may be formed of a binder layer, and the other reflection preventing layer may be formed of a binder with surface irregularities.

FIG. 13is a partial enlarged cross-sectional view, taken long line III-III′ ofFIG. 2, of a first polarizing plate of a display device according to an exemplary embodiment of the present invention.

A first polarizing plate100jofFIG. 13is substantially the same as the first polarizing plate100iofFIG. 12except for the structure of a second reflection preventing layer150j, and thus will hereinafter be described, focusing mainly on the second reflection preventing layer150j.

Referring toFIG. 13, the second reflection preventing layer150jis disposed on the top of a first protective layer120, and may be formed of a binder150j-1and a plurality of beads150j-2scattered in the binder150j-1to diffuse light. The second reflection preventing layer150jhas a flat surface having no surface irregularities.

A first reflection preventing layer140jis disposed on the bottom of the first protective layer120, and may be formed of a binder140j-1and a plurality of beads140j-2scattered in the binder140j-1to diffuse light. The first reflection preventing layer140jhas surface irregularities.