JP6166510B2 - Liquid crystal display - Google Patents

Description

  The present invention relates to a liquid crystal display device having a color filter substrate, and in particular, by using white light and blue light as a light source of a backlight device and transmitting blue light through a clear layer formed on the color filter substrate, The present invention relates to a liquid crystal display device with improved color purity and brightness.

  In recent years, liquid crystal display devices having features such as light weight, thinness, and low power consumption have been widely used as display devices for information devices such as personal computers and mobile phones, and display devices for video devices such as televisions, video movies, and car navigation systems. Yes.

  In such a liquid crystal display device, a configuration in which a backlight device for irradiating illumination light from behind the liquid crystal display panel is usually used is often used.

  Here, the backlight device used as a surface light source device is roughly classified into an edge light method and a direct light method depending on the location of the light source. For example, in the edge light system, a light emitting part is formed by arranging a plurality of LEDs or the like as point light sources on one end face of a light guide plate arranged opposite to a liquid crystal display panel, or a light emitting part of a tubular light source (fluorescent tube etc.) It is a method to arrange. The direct method is a method in which a plurality of straight tubular light sources such as fluorescent tubes are arranged on the back surface of the liquid crystal display panel, and a diffusion plate or the like is arranged between the liquid crystal display panel and the light source.

  Among these methods, the edge light method is particularly advantageous in terms of thinning, and can be said to be a method suitable for, for example, a display device of a small portable electronic device or a notebook personal computer.

  In the edge-light type backlight device, it is necessary to convert light from the light source into planar light. Therefore, a light guide plate for guiding the light incident from the light source is installed, and an optical sheet is provided on the light exit surface of the light guide plate. And a reflective sheet on the back surface opposite to the light exit surface, which enables conversion to planar light and improves brightness, directivity, light uniformity, etc. Has been done.

  Generally, a liquid crystal display device including an edge light type backlight device uses white light as a light source of the backlight device, and transmits the white light through a color filter including a red colored layer, a green colored layer, and a blue colored layer. An image such as a desired character or video is displayed at a predetermined brightness.

JP 2010-243960 A JP 2011-192468 A

  However, recently, in response to the demand for high brightness of the screen in a liquid crystal display device having a color filter, for the pixels of the blue colored layer, even if a pigment having the highest transmittance among currently available pigment systems is applied, It cannot be said that sufficient light transmittance is secured, and the luminance tends to decrease. On the other hand, even when using a triphenylmethane dye that is excellent in light transmission and reported to have a certain degree of heat resistance, the triphenylmethane dye has heat resistance and light resistance. Since it is inferior to the pigment in terms of the point, for example, after undergoing a thermal process, which is an essential process when forming a liquid crystal display device, the chromaticity tends to change and the luminance tends to decrease.

  The present invention was devised under such circumstances, and an object thereof is to provide a liquid crystal display device capable of improving the color purity and luminance of blue.

In order to solve the problems described above, the present invention is a liquid crystal display device having a backlight device and a liquid crystal display panel, the backlight device having a light source and a light guide plate, The liquid crystal display panel includes a color filter substrate and a display array substrate, the color filter substrate includes at least a red colored layer, a green colored layer, and a clear layer, and the light guide plate receives light. The light source is arranged so that light is introduced into the light incident surface, and the light source includes a white light emitting unit that emits white light and a blue light emitting unit that emits blue light possess the door, the white light emitting portion is configured having a first light emitting element and a first sealing body, wherein the blue light-emitting unit includes a second light-emitting element and a second sealing body A first light-emitting element configured as a base of the white light-emitting portion. Sb = (0.3-0.7) Sw, where Sw is the number of devices and Sb is the number of second light-emitting elements that serve as the base of the blue light-emitting unit, and is driven in a field sequential manner. The liquid crystal display device includes a control circuit unit for enabling a color display method by a field sequential method, and a time zone emitted from the white light emitting unit and a time zone emitted from the blue light emitting unit are: It is configured to be divided and operated without overlapping .

As a more preferable embodiment of the liquid crystal display device of the present invention, the light source is constructed are arranged along the light incident surface is one end surface of the light guide plate.

  As a more preferable aspect of the liquid crystal display device of the present invention, the light source includes a substrate, a white light emitting unit that emits white light formed on the substrate, and a blue light emitting unit that emits blue light. The

  As a more preferable aspect of the liquid crystal display device of the present invention, the backlight device is configured by an edge light system.

  As a more preferable aspect of the liquid crystal display device of the present invention, an optical sheet is disposed on the light exit surface side of the light guide plate, and a reflective sheet is disposed on the surface of the light guide plate facing the light exit surface.

  The present invention is a liquid crystal display device having a backlight device and a liquid crystal display panel, the backlight device having a light source and a light guide plate, the liquid crystal display panel having a color filter substrate and a display The color filter substrate has a red colored layer, a green colored layer, and a clear layer, the light guide plate has a light incident surface and a light exit surface, and the light source has a light incident surface. The light source has a white light emitting part that emits white light and a blue light emitting part that emits blue light, and emits blue light through a clear layer formed on the color filter substrate. Since it is configured to transmit, blue color purity and luminance are improved. Furthermore, since it is not necessary to add a blue coloring material, the material cost can be reduced and the cost can be reduced.

FIG. 1 is an exploded perspective view showing an example of a backlight device used in the liquid crystal display device of the present invention. FIG. 2 is a plan view taken along the line α-α shown in FIG. 1 and shows a configuration of a main part of a light source of the backlight device. FIG. 3 is a plan view similar to FIG. 2, and is a plan view showing a modification of the main configuration of the light source of the backlight device. FIG. 4 is a plan view similar to FIG. 2, and is a plan view showing a modification of the main configuration of the light source of the backlight device. 5A is a cross-sectional view taken along the line β1-β1 in FIG. 2, and FIG. 5B is a cross-sectional view taken along the line β2-β2 in FIG. 2. FIG. 6 is a cross-sectional view for explaining an example of a color filter substrate and a display array substrate for constituting a liquid crystal display device. FIG. 7 is a partial cross-sectional view of a display device formed by combining a color filter substrate, a display array substrate, and a backlight device. However, the backlight device is not shown in a sectional view. FIG. 8 is a plan view for explaining the configuration of the pixel portion of the color filter substrate. FIG. 9 shows the lighting time of each of the white light emitting portion and the blue light emitting portion of the backlight device when the liquid crystal display device of the present invention is driven by the field sequential method unique to the present invention to display a specific color. 6 is a color display timing chart showing the relationship between the timing of opening the shutter corresponding to each pixel portion of the red colored layer, the green colored layer, and the clear layer constituting the pixel.

  Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited to the form demonstrated below, In the range which does not deviate from a technical thought, it can implement in various deformation | transformation. In the accompanying drawings, the scales of the top, bottom, left and right are sometimes exaggerated for easy understanding, and the scales may differ from the actual ones.

  A liquid crystal display device having a color filter substrate according to a preferred embodiment of the present invention will be described with reference to FIGS.

  As shown in FIG. 7, the liquid crystal display device 1 of the present invention includes a liquid crystal display panel 150 and a backlight device 200, and the liquid crystal display panel 150 includes a color filter substrate 30 and a display device. It has an array substrate 100 and a liquid crystal part 140.

Hereinafter, these components will be described in detail.
First, a backlight device 200 used in the liquid crystal display device of the present invention will be described with reference to FIGS.

<Backlight device 200>
FIG. 1 is an exploded perspective view showing an example of a backlight device 200 used in the liquid crystal display device 1 of the present invention. FIG. 2 is a plan view taken along the line α-α shown in FIG. 1 and shows a configuration of a main part of a light source of the backlight device. 3 and 4 are plan views showing modifications of FIG. 5A is a cross-sectional view taken along the line β1-β1 in FIG. 2, and FIG. 5B is a cross-sectional view taken along the line β2-β2 in FIG. 2.

  As shown in FIG. 1, the backlight device 200 includes a light source 220 and a light guide plate 210. The light guide plate 210 has a substantially quadrangular flat plate shape, and in the drawing, an upper surface 210b that is an upper main plane, a lower surface 210c that is a lower main plane, and a periphery of the upper surface 210b and the lower surface 210c. Are connected to each other. In the present embodiment, one end surface 210a of the light guide plate, which is one of the four side surfaces, constitutes the light incident surface 210a, and the light source 220 is introduced so that light is introduced into the light incident surface 210a. Is placed. With such an arrangement, a so-called edge light type backlight device can be formed. In addition, you may make it provide a reflecting film in three side surfaces except the light-incidence surface 210a.

  Further, a reflection sheet 260 is usually provided on the lower surface 210c of the light guide plate 210, and an optical sheet 250 is usually provided on the upper surface 210b (light emission surface 210b) of the light guide plate 210. The light guide plate 210, the light source 220, the optical sheet 250, and the reflection sheet 260 are accommodated in a thin box-like back case 270 made of, for example, metal.

  The light guide plate 210 may be made of a material such as polycarbonate resin or acrylic resin that has excellent transparency and good light transmission.

  In addition, a dot pattern of minute protrusions for diffusing reflected light on the lower surface 210c may be formed on the lower surface 210c of the light guide plate 210. The light guide plate 210 may contain scattering particles for changing the direction of the light path. The light guide plate 210 is generally formed by an extrusion molding method, an injection molding method, or the like. When the extrusion molding method is used, the light guide plate 210 is usually manufactured by punching a molded sheet body into a predetermined size.

(light source)
As shown in FIGS. 1 to 2, the light source 220 according to the present invention includes a long substrate 221, a white light emitting unit 230 </ b> W that emits white light formed on the main surface of the substrate 221, and blue light. It is a module type light source configured to have a blue light emitting unit 240B that emits light. Such a light source 220 normally faces the light incident surface 210a, which is one side end surface 210a of the light guide plate 210, so that light is introduced into the light incident surface 210a so as to be substantially parallel to the light incident surface 210a. It is desirable to be arranged.

  The white light emitting unit 230 </ b> W, which is one element constituting the light source 220, includes a first light emitting element 231 such as an LED element and a first sealing body 232. The first sealing body 232 includes a light-transmitting material such as a resin and a wavelength conversion material such as a phosphor that is used as necessary. A wavelength conversion material such as a phosphor is used when it is necessary to convert the wavelength of light from the first light emitting element 231 to a desired wavelength.

For example, a suitable specific example of the white light emitting unit 230 </ b> W is exemplified. For example, a GaN-based blue LED that emits blue light is used as the first light emitting element 231, and blue light is emitted as white light as the first sealing body 232, for example. YAG phosphor ((Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺ ), silicate phosphor ((Sr, Ba) ₂ SiO ₄ : Eu ²⁺ ), nitride phosphor ((Ca, Sr, Ba) AlSiN ₃ : Eu ²⁺ ), wavelength conversion materials such as oxynitride phosphors (Ba ₃ Si ₆ O ₁₂ N ₂ : Eu ²⁺ ), and silicone covering the first light emitting element 231 and the wavelength conversion material Examples thereof include using a light-transmitting material such as a resin. In this case, the white light emitting unit 230 </ b> W can also be regarded as a white LED formed with a blue LED and a phosphor that converts blue light into white light. In addition, it is not limited to said specific example, You may make it comprise the white light emission part 230W which can emit white light by structures other than the above.

  On the other hand, the blue light emitting unit 240B, which is another element constituting the light source 220, includes a second light emitting element 241 such as an LED element and a second sealing body 242. That is, the second light emitting element 241 and the second sealing body 242 constitute one blue light emitting portion 240B that emits blue light, and the second sealing body 242 includes a light-transmitting material such as a resin, and as necessary. And a wavelength conversion material such as a phosphor used. A wavelength conversion material such as a phosphor is used when it is necessary to convert the wavelength of light from the second light emitting element 241 to a desired wavelength.

  As a specific example of the blue light emitting unit 240B, for example, a GaN blue LED that emits blue light is used as the second light emitting element 241, and the second light emitting element 241 is covered as the second sealing body 242. It is mentioned to use translucent materials, such as a silicone resin. However, the present invention is not limited to such a specific example, and the blue light emitting unit 240B that can emit blue light may be configured by a configuration other than the above. For example, an LED that emits light having a wavelength shorter than that of blue is used as the second light emitting element 241, a wavelength conversion material made of a phosphor that converts light having a wavelength shorter than blue into blue light, and the second light emitting element 241 and A translucent material such as a silicone resin covering the wavelength conversion material may be used.

  Note that the first light-emitting element 231 and the second light-emitting element 241 can be the same element.

  In the present invention, the number of installed first light emitting elements 231 serving as the base of the white light emitting unit 230W is set to be greater than the number of installed second light emitting elements 241 serving as the base of the blue light emitting unit 240B. More specifically, when the number of installed first light emitting elements 231 serving as the base of the white light emitting unit 230W is Sw and the number of installed second light emitting elements 241 serving as the base of the blue light emitting unit 240 is Sb, Sb = ( 0.3 to 0.7) Sw, more preferably Sb = (0.4 to 0.6) Sw.

  The above range is set because the liquid crystal display device of the present invention uses the desired color filter substrate and is driven by the desired field sequential method to perform color display. . That is, as will be described in detail later, for example, all the white light emitting units 230W are turned on for 2/180 seconds, and the red that mainly constitutes approximately 2/3 area of one pixel during this lighting time. By allowing the colored layer and the green colored layer to pass through, the red and green color display is caused to contribute, and for the next 1/180 seconds, all the blue light emitting portions 240W are turned on, This is because the clear layer constituting approximately 1/3 area of one pixel is transmitted in the meantime so as to contribute to blue color display.

  The relationship between the number of white light emitting units 230W and blue light emitting units 240B in the light source 220 shown in FIG. 2 is Sb = 0.5Sw, that is, the total number of white light emitting units 230W occupies about 66.7% of the total. The total number of blue light emitting portions 240 is configured to occupy about 33.3% of the total. In the case of FIG. 2, one unit in which one blue light emitting unit 240B is arranged after two white light emitting units 230W are continuously arranged is repeatedly arranged. As shown in FIG. 3, an area where the white light emitting units 230 </ b> W are aggregated in one place and an area where the blue light emitting parts 240 </ b> B are aggregated in one place may be provided. Further, as shown in FIG. 3, when the white light emitting unit 230W and the blue light emitting unit 240B are aggregated, as shown in FIG. 4, the individual first sealing body and the second sealing body described above are combined. The first sealing body 236 and the second sealing body 246 can also be integrated together.

  It should be noted that a red colored layer, a green colored layer, and a clear layer formed on a color filter substrate, which will be described later, in accordance with the set ratio of the number of installed first light emitting elements 231 Sw and the number of installed second light emitting elements 241 Sb. The respective area ratios (pixel aperture ratios) can be appropriately changed.

Next, another configuration of the backlight device 200 will be described.
(Optical sheet)
The optical sheet 250 is disposed on the light exit surface 210b of the light guide plate 210 and usually has a plurality of unit prisms. The optical sheet is used to change the traveling direction of the light incident on the light guide plate 210 from the light incident surface 210a to be emitted from the light emitting surface 210b, and to intensively improve luminance and the like. As such an optical sheet 250, a general sheet used in a liquid crystal display device can be used. Various known forms can be adopted for the cross-sectional shape, protrusion height, bottom width, apex angle, etc. of the unit prism.

  The material of the optical sheet 250 is not particularly limited as long as an optical sheet having a plurality of unit prisms can be produced. For example, polycarbonate resin, ABS (acrylonitrile-butadiene-styrene copolymer) resin, methacrylic resin can be used. Examples thereof include resins, methyl methacrylate-styrene copolymer resins, polystyrene resins, acrylonitrile-styrene copolymer resins, polyethylene resins, and polypropylene resins.

  What is necessary is just to adjust the thickness of an optical sheet suitably, for example, it can be set as about 5 micrometers-100 micrometers. As a method for producing the optical sheet, a general method can be used. For example, the optical sheet is pressed against the surface of the ultraviolet curable resin by using a mold having a shape corresponding to the unit prism on the surface, and then ultraviolet rays are used. Examples include a curing method.

(Reflective sheet)
The reflection sheet 260 is disposed on the lower surface 210 c that is the back surface of the light guide plate 210. The reflection sheet 260 is used to reflect light traveling toward the back surface of the light guide plate 210 and enter the light guide plate 210 again. As the reflection sheet 260, a general reflection sheet can be used. For example, a white scattering reflection sheet, a sheet made of a material having a high reflectance such as metal, a thin film made of a material having a high reflectance (for example, a metal) The sheet | seat etc. which equip a part with a thin film can be mentioned.

  Specific examples of the material of the reflection sheet 260 include resins such as polyethylene terephthalate (PET (white PET)), polycarbonate (PC), polystyrene, and polyolefin, and metals such as aluminum and silver. Moreover, when using resin for the reflective sheet 260, in order to improve reflectivity, it is preferable to set it as the white sheet | seat containing a pigment. Examples of the pigment to be included include titanium dioxide, barium sulfate, magnesium carbonate, and calcium carbonate. When a metal thin film is provided on a part of the reflection sheet 260, a metal film having a high reflectance such as silver, aluminum, or chromium may be formed by a vapor deposition method, a sputtering method, a CVD method, or the like. A commercially available product may be used as the reflection sheet 260. Examples of commercially available products include (Vicuity) ESR reflective film manufactured by Sumitomo 3M Limited, E60V manufactured by Toray Industries, Inc., and the like. When such a commercial product is used, the light guide plate 210 and the reflective sheet 260 may be bonded together by interposing a resin having a refractive index matched.

  The thickness of the reflection sheet is not particularly limited and may be adjusted as appropriate, and can be, for example, about 30 μm to 300 μm.

(Other configurations around the backlight device 200)
In the present invention, although not shown, a diffusion sheet having a function of diffusing transmitted light or a polarized light reflection function having a polarization separation function by transmitting only a specific polarization component and reflecting other polarization components. A sheet or the like may be provided on the light exit surface side of the optical sheet 250.

  The diffusion sheet is a member having a function of diffusing light emitted from the optical sheet to reduce luminance unevenness. As the diffusion sheet, a general sheet used in a liquid crystal display device can be used. Examples of the material of the diffusion sheet include methyl methacrylate styrene copolymer, acrylonitrile styrene copolymer, polycarbonate (PC), polyethylene terephthalate (PET), polystyrene, and the like. Further, the diffusion sheet may contain particles. Examples of the particles include inorganic particles such as silica and alumina, fluorine resin particles such as acrylic resin, styrene resin, polytetrafluoroethylene, and polyfluorovinylidene, and silicone resin particles. These particles can be used alone or in combination of two or more. The average particle diameter of the particles is preferably in the range of 0.3 μm to 2.0 μm from the viewpoint of scattering properties. The content of the particles may be adjusted as appropriate. The thickness of the diffusion sheet can be, for example, about 5 μm to 100 μm.

  The polarization reflection sheet is a member having a polarization separation function that transmits only a specific polarization component of light emitted from the optical sheet 250 and reflects other polarization components. In a liquid crystal display device, when a polarizing plate is provided between the liquid crystal cell and the polarizing reflection sheet, the polarizing plate selectively transmits only a specific polarization component. By selectively reflecting and reusing other polarization components, the amount of light passing through the polarizing plate can be substantially increased and the luminance can be improved.

  As the polarizing reflection sheet, a general sheet used in a liquid crystal display device can be used. Commercially available products may be used as the polarizing reflection sheet, and for example, DBEF series manufactured by Sumitomo 3M Limited can be used.

  Further, a heat sink for releasing the heat generated from the light source may be formed.

  Note that a lighting control circuit for controlling lighting of the white light emitting unit 230W and the blue light emitting unit 240B in the light source of the present invention may be provided on the back side of the backlight device 200 or the like.

Next, the color filter substrate 30 will be described.
<Color filter substrate 30>
As described in the upper side of FIG. 6, the color filter substrate 30 used in the liquid crystal display device 1 of the present invention includes a transparent substrate 10 and a pixel component layer that is a pixel portion formed on the transparent substrate 10. 13 and a light shielding portion 12 formed around the pixel configuration layer 13. In general, if attention is paid to most of the other pixel configuration layers 13 excluding the pixel configuration layer 13 disposed on the outermost periphery of the substrate, the light shielding portion 12 exists in the gap portion between the adjacent pixel configuration layers 13. To do.

  The transparent substrate 10 is not particularly limited as long as it is a substrate transparent to visible light, and the same transparent substrate used for a general color filter can be used. Specifically, a rigid material such as quartz glass, Pyrex (registered trademark) glass, or synthetic quartz, or a transparent flexible material having flexibility such as a transparent resin film or an optical resin plate can be used.

  The characteristic structure of the color filter substrate 30 used in the present invention is that a blue colored layer is not used as the type of the pixel constituent layer 13, and a light-transmitting clear layer is used instead. is there.

  That is, as shown in FIG. 6 and FIG. 8, the pixel constituent layer 13 has a red colored layer 13R, a green colored layer 13G, and a clear layer 13T, which are usually patterned in a state in which these are sequentially arranged. Yes.

  As described above, the red colored layer 13R, the green colored layer 13G, and the red colored layer 13G formed on the color filter substrate 30 according to the set ratio of the installed number Sw of the first light emitting elements 231 and the installed number Sb of the second light emitting elements 241; Each area ratio (pixel aperture ratio) of the clear layer 13T can be appropriately changed. In the present invention, since the color display through the color filter substrate 30 is performed by the field sequential method desired by the present application, one set of the red colored layer 13R, the green colored layer 13G, and the clear layer 13T constitutes one pixel. A specific example of the color display method using the field sequential method in the present invention will be described in detail later.

  It should be noted that the number of pixel configuration layers 13 (number of pixels), which is a pixel portion in the drawings, is described only as an example, and is not limited to the illustrated example. As a method for forming the pixel configuration layer 13, a method for forming the pixel configuration layer 13 in a general color filter, for example, a photolithography method, an inkjet method, a printing method, or the like may be used.

  Examples of the coloring material used for the red colored layer 13R include perylene pigments, lake pigments, azo pigments, quinacridone pigments, anthraquinone pigments, anthracene pigments, and isoindoline pigments. These pigments may be used alone or in combination of two or more.

  Examples of coloring materials used for the green colored layer 13G include phthalocyanine pigments such as halogen polysubstituted phthalocyanine pigments or halogen polysubstituted copper phthalocyanine pigments, triphenylmethane basic dyes, isoindoline pigments, and isoindolinone. And pigments. These pigments or dyes may be used alone or in combination of two or more.

  The clear layer 13T is basically a resin layer that acts to transmit light from the light source in the same hue, and is preferably a non-colored resin layer. However, in order to adjust the hue of light that has passed through the clear layer 13T, a hue adjusting color material may be added to the clear layer 13T by about 4% or less. Therefore, the clear layer 13T of the present invention includes those in which a color material for adjusting the hue is contained in an amount of 4% or less with respect to the solid content constituting the clear layer 13T. As a main material for forming the clear layer 13T, a resin used as a binder can be used. However, the material is not particularly limited as long as the material is excellent in transparency and light transmittance. Examples of color materials that can be added to the clear layer 13T include blue, cyan, magenta, yellow, and the like.

  Specific examples of the binder resin that can be suitably used include a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate, and the like. Solvents include benzene, toluene, xylene, n-butylbenzene, diethylbenzene, tetralin and other hydrocarbons, methoxybenzene, 1,2-dimethoxybenzene, diethylene glycol dimethyl ether and other ethers, acetone, methyl ethyl ketone, methyl isobutyl ketone. , Ketones such as cyclohexanone and 2,4-pentanedione, ethyl acetate, ethylene glycol monomethyl ether acetate, propylene glycol monomethyl ether acetate, propylene glycol monoethyl ether acetate, esters such as g-butyrolactone, 2-pyrrolidone, N- Amide solvents such as methyl-2-pyrrolidone, dimethylformamide, dimethylacetamide, chloroform, dichloromethane, carbon tetrachloride, dichloro Halogen solvents such as ethane, tetrachloroethane, tritrichloroethylene, tetrachloroethylene, chlorobenzene, orthodichlorobenzene, t-butyl alcohol, diacetone alcohol, glycerin, monoacetin, ethylene glycol, triethylene glycol, hexylene glycol, ethylene glycol monomethyl ether, ethyl One type or two or more types of alcohols such as cellsolve and butylcellsolve and phenols such as phenol and parachlorophenol can be used.

  If only one type of solvent is used, the solubility of the coating composition may be insufficient, or the material that forms the coating partner when the coating composition is applied (the material constituting the substrate) may be affected. In the case where there is, for example, these disadvantages can be avoided by using a mixture of two or more solvents. Moreover, you may make it contain surfactants, such as a fluorosurfactant and a nonionic surfactant, as needed.

  The light-shielding portion 12 (sometimes referred to as a so-called black matrix) in the present embodiment is desirably formed, but is not indispensable for exhibiting the effects of the present invention. The light shielding portion 12 is usually configured as a lattice-shaped light shielding layer, and is usually configured using a photoresist, a printing ink, or a metal such as chromium containing a black pigment, a binder resin, and a solvent. Examples of black pigments used in printing inks include carbon black and titanium black. Examples of binder resins include benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate copolymer. The solvent can be selected from various known solvents. As a method for forming the light shielding portion 12, it can be formed by a photolithography method, various pattern printing methods, various plating methods, and the like.

  As shown in FIG. 6, the transparent electrode layer 18 is formed so as to cover the pixel constituting layer 13 having the red colored layer 13R, the green colored layer 13G, and the clear layer 13T. Examples of the material for forming the transparent electrode layer 18 include a metal oxide having transparency and conductivity. Examples of such a metal oxide include indium tin oxide (ITO), indium oxide, zinc oxide, and stannic oxide. The film thickness of the transparent electrode layer 18 is 50 nm to 1500 nm, and more preferably 120 nm to 1200 nm.

  As a method for forming the transparent electrode layer 18, for example, a vapor deposition method or a sputtering method may be used. An overcoat layer (protective film) or the like may be formed before forming the transparent electrode layer 18.

[Description of the display array substrate 100]
Next, the display array substrate 100 (liquid crystal display substrate) will be described with reference to FIG.

  The display array substrate 100 shown on the lower side of FIG. 6 is disposed so as to face the color filter substrate 30 described above, and is integrated to form a display device. In FIG. 6, the color filter substrate 30 arranged to face is also described. The color filter substrate 30 shown in FIG. 6 is formed on the alignment electrode 18 on the transparent electrode layer 18 in order to form a display device. The state in which 20 is formed is depicted. The alignment film 20 is usually provided at the time of the next cell combination step for completing the manufacturing process of the color filter substrate 30 and forming a display device.

  As shown in FIG. 6, the display array substrate 100 is configured by a scanning line (not shown), an interlayer insulating film 60, and a large number of pixel electrodes 65a arranged in a matrix on a light-transmitting substrate 55. A structure having a transparent electrode 65, a signal line 70, a protective film (passivation film) 75, a switching circuit portion (not shown), and an alignment film 80 is provided.

  Although the scanning lines are not displayed in the drawing, for example, the scanning lines are arranged so as to correspond to one row (a horizontal direction in the drawing) of a large number of pixel electrodes 65a arranged in a matrix. It is comprised so that it may extend in the longitudinal direction. Each scanning line can be formed of a metal such as tantalum (Ta) or titanium (Ti), for example. These scanning lines are covered with an interlayer insulating film 60.

  The interlayer insulating film 60 is formed of an electrically insulating material such as silicon oxide, for example, and electrically separates the scanning line and the signal line 70 and electrically connects the pixel electrode 65a and the scanning line. It is formed to separate.

  Each pixel electrode 65a is formed so as to correspond to one pixel portion in the display device. Examples of the material for forming the pixel electrode 65a include a metal oxide having transparency and conductivity. Examples of such a metal oxide include indium tin oxide (ITO), indium oxide, zinc oxide, and stannic oxide. The film thickness of the formed electrode layer is 50 nm to 1500 nm, more preferably 120 nm to 1200 nm. As a method for forming the pixel electrode 65a, for example, an evaporation method or a sputtering method may be used. The shape of each pixel electrode 65a in plan view can be, for example, a quadrilateral or a polygon such as a hexagon formed by cutting one corner of the quadrilateral into a rectangle, but is not necessarily limited to these shapes. It is not something.

  For example, the signal lines 70 are arranged so as to correspond to one column (in the direction of the back side of the paper surface) of a large number of pixel electrodes 65a arranged in a matrix and extend in the longitudinal direction of the column. Configured as follows. Each signal line 70 can be formed of a metal such as tantalum (Ta) or titanium (Ti). These signal lines 70 are covered with a protective film 75.

  The protective film 75 is made of, for example, silicon nitride, and functions as a protective film of the main body and acts to electrically separate the signal line 70 and the pixel electrode 65a.

  Although the switching circuit section is not shown in FIG. 6, the switching circuit section is arranged corresponding to one pixel electrode 65a one by one, and the pixel electrode 65a corresponding to the switching circuit section, the scanning line, and the signal line 70 is electrically connected.

  Each switching circuit unit receives a signal from a corresponding scanning line and controls conduction between the signal line 70 and the pixel electrode 65a. Each switching circuit unit can be configured using, for example, an active element. As the active element, for example, a three-terminal element such as a thin film transistor (TFT) or a two-terminal element such as a MIM (Metal Insulator Metal) diode is used, but is not necessarily limited thereto.

  The alignment film 80 can be configured as a horizontal alignment film that can horizontally align the liquid crystal in the display device, or a vertical alignment film that can vertically align the liquid crystal. Which of the horizontal alignment film and the vertical alignment film is used can be appropriately selected according to the operation mode of the display device. The alignment film 80 formed on the display array substrate 100 side can have the same configuration as the alignment film 20 formed on the color filter substrate 30 side.

  The display array substrate 100 used in the liquid crystal display device 1 of the present invention is configured to be driven by a desired field sequential method. In the field sequential method in the present invention, the white light emitting unit 230W and the blue light emitting unit 240B are sequentially blinked at high speed (for example, the white light emitting unit 230W is 2/180 seconds and the blue light emitting unit 240 is 1 / By causing these white light or blue light to pass through the red colored layer 13R, the green colored layer 13G, and the clear layer 13T provided on the color filter substrate 30 as appropriate, the afterimage phenomenon of human beings can be prevented. This is the image display method used. The white light emitted from the white light emitting unit 230W mainly acts on the red colored layer 13R and the green colored layer 13G, and the blue light emitted from the blue light emitting unit 240B acts on the clear layer 13T. This will be described in detail later with reference to FIG.

[Configuration of liquid crystal display device]
As described above, the color filter substrate 30 on which the alignment layer 20 is formed and the display array substrate 100 on which the alignment layer 80 is formed have the alignment layer 20 and the alignment layer 80 facing each other as shown in FIG. In a state where a predetermined gap is provided, the sealing material (for example, thermosetting resin) 90 is bonded together leaving a filling port for filling the liquid crystal material.

  The gap (cell gap) between the display array substrate 100 and the color filter substrate 30 is kept constant by a spacer (for example, a spherical spacer or a columnar spacer) not shown, and the gap between the two is provided from the filling port. A liquid crystal layer 91 is formed by filling the liquid crystal material. As the liquid crystal used for the liquid crystal layer 91, it is preferable to use a liquid crystal of ferroelectricity or the like capable of a high-speed response with a response speed of about several tens of μs in order to correspond to the desired field sequential method. The filling port after liquid crystal filling is sealed. Then, as shown in FIG. 7, the backlight device 200 as a light source is disposed behind the light transmissive substrate 55 of the display array substrate 100 to form the liquid crystal display device 1.

  Although not shown, normally, polarizing plates are bonded to the outer surfaces of the display array substrate 100 and the color filter substrate 30 with their polarization axes orthogonal to each other.

[Color Display Method by Field Sequential Method of Liquid Crystal Display Device of the Present Invention]
With reference to FIG. 9, a color display method by a field sequential method of the liquid crystal display device of the present invention will be described. The present invention includes a control circuit unit for enabling a color display method based on the field sequential method unique to the present application.

  FIG. 9 shows lighting times (horizontal axis) of the white light emitting unit 230W and the blue light emitting unit 240B of the backlight device when the liquid crystal display device 1 of the present invention is driven in a field sequential manner to display a specific color. 4 is a timing chart of color display showing the relationship between the timing of opening the shutter corresponding to each pixel portion of the red coloring layer, the green coloring layer, and the clear layer constituting one pixel.

  In the field sequential method of FIG. 9 according to the present invention, the white light emitting unit 230W of the backlight device as the light source is repeatedly blinked for 2/180 seconds, for example, and the blue light emitting unit 240B is blinked for 1/180 seconds, for example. The time zone emitted from the white light emitting unit and the time zone emitted from the blue light emitting unit are operated separately without overlapping.

  For these light sources, “13R open” in FIG. 9 indicates a state in which the shutter corresponding to the red colored layer 13R constituting a part of one pixel shown in FIG. "Indicates a state in which the shutter corresponding to the green colored layer 13G constituting a part of one pixel shown in FIG. 8 is open, and" 13T open "indicates one pixel shown in FIG. The state which has opened the shutter corresponding to the clear layer 13T which comprises a part is shown. In FIG. 9, areas without display such as “13R open”, “13G open”, and “13T open” described above are formed on the red colored layer 13R, the green colored layer 13G, and the clear layer 13T constituting one pixel. All the corresponding shutters remain closed, and the area is drawn with a dotted line in FIG.

  No. in FIG. 1-No. 9 shows an example of a timing chart of color display when white display, white display, red display, green display, blue display, yellow display, magenta display, cyan display, and black display are performed. Hereinafter, referring to FIG. Each will be explained.

(1) No. 1: White display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, this 2/180 seconds is set to “13T open”. That is, the shutter corresponding to the clear layer 13T constituting a part of one pixel shown in FIG. 8 is opened, and white light is transmitted. In this case, white light as a light source can be used as it is. The “13T open” time can also be 1/180 seconds (between a and b, or between b and c).

(2) No. 2: White display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13R open”, and the next 1/180 seconds is set to “13G open”. Then, while the blue light emitting unit 240B of the next backlight device is lit for 1/180 seconds, this 1/180 seconds is set to “13T open”. As a result, white display as one pixel is recognized by combining the afterimage colors of the transmitted red, green, and blue. “13R open” and “13G open” may be reversed.

(3) No. 3: Red display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13R open”. As a result, red display as one pixel is recognized by the transmitted afterimage color of red. The time of “13R open” may be 2/180 seconds (between a and c). Note that while the white light emitting unit 230W of the backlight device is lit, the liquid crystal shutter corresponding to the green colored layer 13G is closed.

(4) No. 4: Green display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13G open”. Thus, the green display as one pixel is recognized by the transmitted green afterimage color. The “13G open” time can also be 2/180 seconds (between a and c). Note that while the white light emitting unit 230W of the backlight device is lit, the liquid crystal shutter corresponding to the red colored layer 13R is closed.

(5) No. 5: Blue display While the blue light emitting unit 240B of the backlight device is lit for 1/180 seconds, this 1/180 second is defined as “13T open”. Thereby, the blue display as one pixel is recognized by the transmitted blue afterimage color.

(6) No. 6: Yellow display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13R open”, and the next 1/180 seconds is set to “13G open”. As a result, yellow display as one pixel is recognized by combining the afterimage colors of transmitted red and green. “13R open” and “13G open” may be reversed. At “13R open”, the liquid crystal shutter corresponding to the green colored layer 13G is closed. At “13G open”, the liquid crystal shutter corresponding to the red colored layer 13R is closed.

(7) No. 7: Magenta display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13R open”. In addition, while the blue light emitting unit 240B of the backlight device is lit for 1/180 seconds, this 1/180 seconds is set to “13T open”. As a result, magenta display as one pixel is recognized by combining the transmitted red and blue afterimage colors.

  “13R open” may be 1/180 seconds between b and c instead of 1/180 seconds between a and b. Furthermore, it can be set to continuous 2/180 seconds between a and c. At “13R open”, the liquid crystal shutter corresponding to the green colored layer 13G is closed.

(8) No. 8: Cyan display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds, 1/180 seconds is set to “13G open”. In addition, while the blue light emitting unit 240B of the backlight device is lit for 1/180 seconds, this 1/180 seconds is set to “13T open”. As a result, cyan display as one pixel is recognized by combining the green and blue afterimage colors.

  “13G open” may be 1/180 seconds between a and b instead of 1/180 seconds between b and c. Furthermore, it can be set to continuous 2/180 seconds between a and c. At “13G open”, the liquid crystal shutter corresponding to the red colored layer 13R is closed.

(9) No. 9: Black display While the white light emitting unit 230W of the backlight device is lit for 2/180 seconds and while the blue light emitting unit 240B of the backlight device is lit for 1/180 seconds, red constituting one pixel All the shutters corresponding to the colored layer 13R green colored layer 13G clear layer 13T remain closed. Thereby, black display as one pixel is recognized.

  The present invention will be described in more detail with reference to specific examples below, but the present invention is not construed as being limited to the following examples.

[Example 1]
(Preparation of color filter substrate 30)
As the substrate, a glass substrate (Corning 1737 glass) having a plane size of 370 mm × 470 mm and a thickness of 0.7 mm was prepared.

  After washing this substrate in accordance with a conventional method, a negative photosensitive resist (CFPR DN-83 manufactured by Tokyo Ohka Kogyo Co., Ltd.) is applied, exposed through a predetermined mask, developed, and baked to form a light shielding portion 12. A black matrix was formed.

  Next, a negative photosensitive resin composition for red pattern for forming the red colored layer 13R shown below, a negative photosensitive resin composition for green pattern for forming the green colored layer 13G, and clear A negative photosensitive resin composition for a transparent uncolored pattern for forming the layer 13T was prepared.

<Negative photosensitive resin composition for red pattern>
・ Red pigment (Chromophthal red A2B manufactured by Ciba Specialty Chemicals) ... 2.0 parts by weightRed pigment (Chromophthalred BP manufactured by Ciba Specialty Chemicals) ... 1.0 parts by weight Dispersic 161) ... 1.5 parts by weight Monomer (SR399, manufactured by Sartomer) 4.0 parts by weight Polymer I ... 5.0 parts by weight Initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals) 1 .4 parts by weight Initiator (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-biimidazole)... 0.6 parts by weight Solvent ( Propylene glycol monomethyl ether acetate) ... 80.0 parts by weight

<Negative photosensitive resin composition for green pattern>
Green pigment (Daiichi Seika Co., Ltd., Cyanine Green 5370) ... 1.2 parts by weight Green pigment (Daiichi Seika Co., Ltd., Cyanine Green 2GN) ... 1.6 parts by weightYellow pigment (Lanxess Byplast Yellow 5GN01) ... 1.2 parts by weight Dispersant (Disperbic 161 manufactured by Big Chemie) ... 2.0 parts by weight Monomer (SR399 manufactured by Sartomer) ... 4.0 parts by weight Polymer I ... 5.0 parts by weight Initiator (Ciba・ Specialty Chemicals Irgacure 907) 1.4 parts by weight ・ Initiator (2,2′-bis (o-chlorophenyl) -4,5,4 ′, 5′-tetraphenyl-1,2′-bi Imidazole) ... 0.6 parts by weightSolvent (propylene glycol monomethyl ether acetate) ... 80.0 parts by weight

<Negative photosensitive resin composition for transparent uncolored pattern>
-Monomer (SR 399, manufactured by Sartomer)-4.0 parts by weight-Polymer I-5.0 parts by weight-Initiator (Irgacure 907, manufactured by Ciba Specialty Chemicals)-1.4 parts by weight-Initiator (2, 2 '-Bis (o-chlorophenyl) -4,5,4', 5'-tetraphenyl-1,2'-biimidazole) ... 0.6 parts by weightSolvent (propylene glycol monomethyl ether acetate) ... 50.0 parts by weight Part

  The polymer I is based on 100 mol% of a copolymer of benzyl methacrylate: styrene: acrylic acid: 2-hydroxyethyl methacrylate = 15.6: 37.0: 30.5: 16.9 (molar ratio). 2-methacryloyloxyethyl isocyanate was added at 16.9 mol%, and the weight average molecular weight was 42500.

  Next, a negative photosensitive resin composition for red pattern is applied by spin coating so as to cover the black matrix on the glass substrate, and is exposed, developed, and baked through a photomask for red pattern. A red pattern was formed. Then, using the negative photosensitive resin composition for green pattern and the negative photosensitive resin composition for transparent uncolored pattern, the green pattern and the transparent uncolored pattern were formed by the same operation as the above red pattern formation. Formed. Thus, a pixel configuration layer in which a red pattern, a green pattern, and a transparent uncolored pattern were arranged was formed. The arrangement was as shown in FIG.

  Next, the following protective film composition was applied as a color filter protective film composition onto the glass substrate on which each of the pixel constituent layers was formed by a spin coating method.

<Composition of composition for protective film>
・ Methyl methacrylate-styrene-acrylic acid copolymer: 32 parts by weight ・ Epicoat 180S70 (manufactured by Japan Epoxy Resin Co., Ltd.) ... 18 parts by weight ・ Dipentaerythritol pentaacrylate: 42 parts by weight ・ Initiator (Ciba Specialty Chemicals) Irgacure 907) ... 8 parts by weight 3-methoxybutylacetate ... 300 parts by weight Next, after exposing and developing through a photomask and baking to form a protective film, a transparent electrode layer is formed thereon. Then, a color filter substrate was produced.

(Production of backlight device 200)
A backlight device 200 as shown in FIG. 1 was produced.

  As the light guide plate 210, a polycarbonate resin substrate having a length × width dimension of 300 mm × 400 mm and a thickness of 0.5 mm was used.

  As shown in FIGS. 1 and 2, the light source 220 includes a white light emitting unit 230W that emits white light on a acrylic substrate and a blue light emitting unit 240B that emits blue light at a 2: 1 number ratio (total number). 9 are arranged and formed as shown).

The blue light emitting portion 240B is formed of a GaN-based LED light emitting element that emits blue light and a sealing body made of a silicone resin that is a translucent material. The white light emitting unit 230 </ b> W that emits white light includes a GaN-based LED light emitting element that emits blue light, a YAG phosphor ((Y, Gd) ₃ Al ₅ O ₁₂ : Ce ³⁺ ) that is a wavelength conversion material, and translucent light. It formed from the sealing body which consists of a silicone resin which is an adhesive material.

  A white polyester film having a thickness of 250 μm was disposed on the back surface of the light guide plate 210 as the reflection sheet 260.

  As the optical sheet 250, an optical sheet as a so-called prism sheet is disposed on the light exit surface side of the light guide plate. The optical sheet (prism sheet) was produced by forming a plurality of unit prisms on a 125 μm thick polyester film using an acrylic ultraviolet curable resin.

(Production of display array substrate 100)
Next, the display array substrate 100 that is paired with the color filter substrate 30 was fabricated as follows.

  First, as a substrate, a glass substrate (Corning 1737 glass) having a size of 370 mm × 470 mm and a thickness of 0.7 mm was prepared.

  In accordance with a conventional method, a display array substrate 100 was manufactured in which the current flowing through the element of the light emitting portion arranged for each pixel can be controlled by a TFT (Thin Film Transistor) in the drive circuit provided for each element.

(Production of liquid crystal display device 1)
As shown in FIG. 7, the color filter substrate 30 on which the alignment layer 20 is formed and the display array substrate 100 on which the alignment layer 80 is formed are arranged to face each other with a predetermined gap therebetween. The material was filled with a sealant 90 in a state of being filled.

  Thereafter, as shown in FIG. 7, the backlight unit 200, which is a light source, is disposed behind the light-transmitting substrate 55 of the display array substrate 100, thereby manufacturing the liquid crystal display device 1 of the present invention.

  The color display method performed through the color filter substrate 30 is a field sequential method unique to the present invention as shown in FIG.

[Comparative Example 1]
The clear layer 13T of the color filter substrate 30 used in Example 1 was changed to a blue colored layer formed using the following negative photosensitive resin composition for blue pattern. Furthermore, the light source 220 of the backlight device 200 used in the first embodiment is only the white light emitting unit 230W that emits white light (the total number is 9). The color display method that is transmitted through the color filter substrate is a conventional so-called plane division method that is performed using a backlight device having only a light source that emits white light.

  Except for this, a liquid crystal display device of a comparative example was fabricated in substantially the same manner as in Example 1.

<Negative photosensitive resin composition for blue pattern>
・ Purple pigment (trade name Novotex Violet BL-PC VP2429, manufactured by Clariant) ... 0.6 parts by weightBlue pigment (Heliogen Blue L6700F, manufactured by BASF) ... 1.4 parts by weightPigment derivative (Solsperse 5000, manufactured by Avicia) ... 0.2 parts by weight Dispersant (Disperbic 161 manufactured by Big Chemie) ... 0.8 parts by weight Monomer (SR399 manufactured by Sartomer) ... 4.0 parts by weight Polymer I ... 5.0 parts by weight Initiator ( Ciba Specialty Chemicals Irgacure 907) 1.4 parts by weight Initiator (2,2'-bis (o-chlorophenyl) -4,5,4 ', 5'-tetraphenyl-1,2'- Biimidazole) ... 0.6 parts by weightSolvent (propylene glycol monomethyl ether acetate) ... 80.0 parts by weight

  The liquid crystal display device sample of Example 1 and the liquid crystal display device sample of Comparative Example 1 were subjected to an optical property test in the following manner.

<< Optical characteristic test >>
The light transmitted through the color filter substrate in the liquid crystal display device sample of Example 1 and the liquid crystal display device sample of Comparative Example 1 was formed by combining red, green, blue, and these three colors in the CIE chromaticity coordinates. The respective chromaticity coordinates x, y and luminance Y of the synthetic white were measured using a microspectroscope OSP-SP2000 (manufactured by OLYMPUS). The NTSC ratio, which is an index of the color reproduction range, was also obtained.

  The results are shown in Tables 1 and 2 below.

  The effects of the present invention are clear from the above results.

  That is, the liquid crystal display device of the present invention is configured to transmit white light through the clear layer formed on the color filter substrate, particularly using white light and blue light as the light source of the backlight device. Blue color purity and luminance can be improved. Thereby, the brightness | luminance of white light by RGB synthetic | combination can also be improved. NTSC ratio is also improved.

  It can be widely used in the electronics industry including flat displays.

DESCRIPTION OF SYMBOLS 1 ... Liquid crystal display device 13R ... Red colored layer 13G ... Green colored layer 13T ... Clear layer 30 ... Color filter substrate 100 ... Display array substrate 150 ... Liquid crystal display panel 200 ... Backlight device 210 ... Light guide plate 210a ... Light incident surface 210b Light emitting surface 220 Light source 230 W White light emitting portion 231 First light emitting element 232 First sealing body 240B Blue light emitting portion 241 Second light emitting element 242 Second sealing body

Claims (5)

A liquid crystal display device having a backlight device and a liquid crystal display panel,
The backlight device includes a light source and a light guide plate,
The liquid crystal display panel has a color filter substrate and a display array substrate,
The color filter substrate has at least a red colored layer, a green colored layer, and a clear layer,
The light guide plate has a light incident surface and a light exit surface,
The light source, while being positioned so that light is introduced into the light incident surface, the light source may possess a white light emitting portion which emits white light, a blue light-emitting portion that emits blue light,
The white light emitting unit is configured to include a first light emitting element and a first sealing body, and the blue light emitting unit is configured to include a second light emitting element and a second sealing body.
Sb = (0.3 to 0.7) where Sw is the number of installed first light emitting elements as the base of the white light emitting unit, and Sb is the number of installed second light emitting elements as the base of the blue light emitting unit. Is set to Sw,
The liquid crystal display device is driven by a field sequential method, and includes a control circuit unit for enabling a color display method by a field sequential method, and a time zone in which light is emitted from the white light emitting unit and light emitted from the blue light emitting unit. The liquid crystal display device is characterized in that it is operated by being divided without overlapping . The light source, a liquid crystal display device according to claim 1 which is disposed along the light incident surface is one end surface of the light guide plate. 3. The liquid crystal according to claim 1 , wherein the light source includes a substrate, a white light emitting unit that emits white light formed on the substrate, and a blue light emitting unit that emits blue light. 4. Display device. The liquid crystal display device according to claim 1, wherein the backlight device is configured by an edge light method. The optical sheet on the light emitting side of the light guide plate is arranged, the liquid crystal according to any one of claims 1 to claim 4 reflecting sheet surface on the side facing the light exit plane of the light guide plate is arranged Display device.

Images