WO2012147641A1 - Liquid crystal display device - Google Patents

Liquid crystal display device Download PDF

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Publication number
WO2012147641A1
WO2012147641A1 PCT/JP2012/060684 JP2012060684W WO2012147641A1 WO 2012147641 A1 WO2012147641 A1 WO 2012147641A1 JP 2012060684 W JP2012060684 W JP 2012060684W WO 2012147641 A1 WO2012147641 A1 WO 2012147641A1
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WIPO (PCT)
Prior art keywords
light
liquid crystal
phosphor
display device
crystal display
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PCT/JP2012/060684
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French (fr)
Japanese (ja)
Inventor
博敏 安永
壮史 石田
真也 門脇
一弥 甲斐田
龍三 結城
Original Assignee
シャープ株式会社
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Publication of WO2012147641A1 publication Critical patent/WO2012147641A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 
    • G02F1/13—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour  based on liquid crystals, e.g. single liquid crystal display cells
    • G02F1/133—Constructional arrangements; Operation of liquid crystal cells; Circuit arrangements
    • G02F1/1333—Constructional arrangements; Manufacturing methods
    • G02F1/1335—Structural association of cells with optical devices, e.g. polarisers or reflectors
    • G02F1/1336—Illuminating devices
    • G02F1/133617—Illumination with ultraviolet light; Luminescent elements or materials associated to the cell

Definitions

  • the present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a direct type backlight.
  • Patent Document 1 is a prior art document that discloses a liquid crystal display device including a phosphor layer including a phosphor that absorbs light from a light source and emits predetermined light.
  • a liquid crystal display device described in Japanese Patent Application Laid-Open No. 2010-250259 (Patent Document 1) includes a pair of substrates that sandwich a liquid crystal layer, a backlight device disposed on the back surface on one side of the pair of substrates, and a pair of substrates And a polarizing plate formed on the other side of the substrate.
  • a light emitting diode that emits light having a peak wavelength in the range of 380 nm to 420 nm is used as a backlight device. Fluorescence that emits light of a predetermined color by absorbing light having a peak wavelength in the range of 380 nm to 420 nm for each unit pixel on the side opposite to the liquid crystal layer side of the polarizing plate formed on the other side of the pair of substrates.
  • a body layer is arranged.
  • a filter layer that reflects or absorbs light having a wavelength of 420 nm or less is formed on the surface of the phosphor layer opposite to the liquid crystal layer.
  • the light irradiated from the light source and passed through the liquid crystal layer is not incident on the desired subpixel and is not incident on the surrounding subpixels. May be incident.
  • this so-called crosstalk occurs, the displayed image is disturbed and the light that is effectively used is reduced, so that the light use efficiency is lowered.
  • the present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device capable of displaying a high-quality image while improving light utilization efficiency and reducing power consumption.
  • a liquid crystal display device includes a liquid crystal layer, a first substrate and a second substrate facing each other across the liquid crystal layer, and a light source located on the opposite side of the first substrate facing the liquid crystal layer.
  • the liquid crystal display device includes a plurality of types of pixel phosphors that are located on the opposite side of the second substrate facing the liquid crystal layer and that absorb light emitted from the light source and emit light of different colors.
  • a phosphor layer that emits light of a predetermined color for each unit pixel, a first polarizing plate positioned between the light source and the liquid crystal layer, and a second polarizing plate positioned between the phosphor layer and the liquid crystal layer, Is provided.
  • the phosphor layer includes light-shielding portions that are arranged in a grid around each pixel phosphor.
  • Each of the pixel phosphors has a rectangular outer shape composed of a short side and a long side having a length three times the short side in plan view.
  • the distance between the phosphor layer and the liquid crystal layer is not more than twice the length of the short side of the pixel phosphor.
  • the light source emits visible light having a peak wavelength in a range of 380 nm to 420 nm.
  • the plurality of types of pixel phosphors include a red phosphor that absorbs visible light and emits red light and green light, each of which constitutes a plurality of subpixels included in a unit pixel.
  • a green phosphor that emits light and a blue phosphor that emits blue light are included in a unit pixel.
  • the light source emits blue light.
  • the plurality of types of pixel phosphors include a red phosphor that absorbs blue light and emits red light and green light that respectively constitute a plurality of subpixels included in the unit pixel.
  • a green phosphor that emits light.
  • a fluorescent substance layer contains the scatterer which scatters the blue light which comprises the sub pixel contained in a unit pixel.
  • the liquid crystal display device further includes a color filter that is located on the opposite side of the phosphor layer from the side facing the liquid crystal layer and that is arranged with a desired color as a color emitted from the subpixel. .
  • the liquid crystal display device includes red light and green light at a position of a subpixel that emits red light and green light on the side opposite to the side facing the liquid crystal layer of the phosphor layer. Is further provided with a shielding layer that transmits blue light.
  • the liquid crystal display device further includes a lens that is positioned between the first substrate and the light source, and that condenses the light emitted from the light source onto the sub-pixels.
  • the present invention it is possible to display a high-quality image while improving light utilization efficiency and reducing power consumption.
  • FIG. 2 is a partially enlarged plan view of the liquid crystal display device of FIG. 1 as viewed from an arrow II line arrow direction.
  • FIG. 4 is a cross-sectional view schematically showing a state in which light is emitted from a pixel phosphor by light emitted from a light source in the liquid crystal display device according to the embodiment.
  • the liquid crystal display device It is the enlarged view which looked at the lens of the modification from the arrow XII direction of FIG.
  • it is a partial cross-sectional view schematically showing a state in which light is output from a scatterer by light emitted from a light source.
  • FIG. 1 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 1 of the present invention.
  • FIG. 2 is a partially enlarged plan view of the liquid crystal display device of FIG. 1 viewed from the direction of the arrow II line.
  • the liquid crystal display device 100 includes a liquid crystal layer 130, and a first substrate 120 and a second substrate 140 that face each other with the liquid crystal layer 130 interposed therebetween.
  • substrate 140 are bonded together by the sealing material which is not shown in figure.
  • the first substrate 120 is formed with a TFT (Thin Film Transistor) (not shown) and a transparent electrode.
  • a transparent electrode (not shown) is formed on the second substrate 140.
  • the first substrate 120 and the second substrate 140 are formed of a glass substrate.
  • the first substrate 120 and the second substrate 140 are not limited to this, and are formed of a material having translucency and capable of sealing liquid crystal. If it is.
  • the liquid crystal display device 100 is positioned on the side opposite to the side facing the liquid crystal layer 130 of the second substrate 140 and the light source 110 located on the side opposite to the side facing the liquid crystal layer 130 of the first substrate 120.
  • a phosphor layer 170 that includes three types of pixel phosphors 170R, 170G, and 170B that absorb light emitted from the light source 110 and emit light of different colors, and emit light of a predetermined color for each unit pixel. Prepare. Note that the number of pixel phosphors may be four or more, and may be two or more.
  • an LED Light Emitting Diode
  • the light source 110 is not limited to this, and any light that can excite phosphors such as ultraviolet rays to emit light may be used.
  • the light source 110 is not limited to the LED, and for example, a fluorescent tube may be used.
  • the plural types of pixel phosphors absorb the visible light and emit red light so as to emit white light or arbitrary color light for each unit pixel, and green fluorescence that emits green light.
  • Body 170G and blue phosphor 170B emitting blue light.
  • the red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B constitute a plurality of subpixels included in the unit pixel.
  • Eu-activated sulfide-based red phosphor was used as the red phosphor 170R.
  • Eu-activated sulfide green phosphor was used as the green phosphor 170G.
  • Eu-activated phosphate blue phosphor was used as the blue phosphor 170B.
  • the red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B are not limited to the above-described materials, and are composed of phosphors that emit light of a desired color upon receiving light from the light source 110. It only has to be done.
  • the liquid crystal display device 100 includes a first polarizing plate 150 positioned between the light source 110 and the liquid crystal layer 130 and a second polarizing plate 160 positioned between the phosphor layer 170 and the liquid crystal layer 130.
  • the first polarizing plate 150 is located between the first substrate 120 and the light source 110, but is not limited to this position, and is located between the first substrate 120 and the liquid crystal layer 130. May be.
  • the second polarizing plate 160 is located between the second substrate 140 and the phosphor layer 170, but is not limited to this position, and may be located between the liquid crystal layer 130 and the second substrate 140.
  • the phosphor layer 170 includes light-shielding portions 170 ⁇ / b> M that are arranged in a grid surrounding each of the pixel phosphors 170 ⁇ / b> R, 170 ⁇ / b> G, and 170 ⁇ / b> B.
  • Each of the pixel phosphors 170R, 170G, and 170B has a rectangular outer shape that includes a short side and a long side that is three times as long as the short side in plan view.
  • the long side length L 2 is about three times the short side length L 1 .
  • the distance D between the phosphor layer 170 and the liquid crystal layer 130 is not more than twice the short side length L 1 of each of the pixel phosphors 170R, 170G, and 170B.
  • the thickness of the two substrates 140 is determined.
  • FIG. 3 is a cross-sectional view schematically showing a state in which light is emitted from the pixel phosphor by the light emitted from the light source in the liquid crystal display device according to the present embodiment.
  • FIG. 3 only a part of the light emitted from the light source is exemplified and indicated by arrows.
  • the light 200, 201, 202 emitted from the light source 110 travels toward the liquid crystal layer 130.
  • the light 200 travels in a direction orthogonal to the liquid crystal layer 130.
  • the light 201 travels diagonally upward to the left in the figure.
  • the light 202 travels diagonally upward to the right in the figure.
  • Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 170 is absorbed by the pixel phosphors 170R, 170G, and 170B.
  • the pixel phosphors 170R, 170G, and 170B that have absorbed the light are excited to emit light in their respective colors.
  • the red phosphor 170R emits red light 210, 211, 212 as shown in FIG.
  • the light emitted from the red phosphor 170R is scattered light.
  • the light 210 travels in a direction orthogonal to the phosphor layer 170.
  • the light 211 travels obliquely upward to the left in the figure.
  • the light 212 travels obliquely upward to the right in the drawing.
  • the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 170 is the opposite side of the phosphor layer 170 that faces the liquid crystal layer 130. It is desirable to be absorbed by a sorting filter (not shown) located in the area. It is not essential to provide a sorting filter. Note that the sorting filter does not absorb light emitted from the pixel phosphors 170R, 170G, and 170B.
  • the sorting filter can be replaced by a color filter described later.
  • a pseudo white light can be obtained by emitting light from each of the red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B. Further, by selecting a phosphor that emits light, the liquid crystal display device 100 having unit pixels that emit an arbitrary color can be obtained.
  • the distance D between the phosphor layer 170 and the liquid crystal layer 130 is set to be not more than twice the short side length L 1 of each of the pixel phosphors 170R, 170G, and 170B.
  • a simulation result indicating that the light use efficiency can be maintained high will be described.
  • FIG. 4 is a cross-sectional view showing the configuration of the light source unit of the simulation model.
  • the simulation model light source unit 300 includes a light source 310, a lower substrate 320, a light absorber 330, an upper substrate 340, and a phosphor 370.
  • the full width at half maximum of the light intensity of the first light source is 5 °.
  • the full width at half maximum of the light intensity of the second light source is 15 °.
  • the full width at half maximum of the light intensity of the third light source is 27 °.
  • the full width at half maximum of the light intensity of the fourth light source is 34 °.
  • the directivity of the light source 310 decreases in order from the first to the fourth.
  • the lower substrate 320 is disposed at a predetermined interval from the light source 310.
  • the thickness d 1 of the lower substrate 320 was 0.5 mm.
  • a light absorber 330 having an opening 331 is disposed on the lower substrate 320.
  • the light absorber 330 has an opening 331 of 0.12 mm ⁇ 0.38 mm in plan view, and all of the light emitted from the light source 310 other than the light passing through the opening 331 is light. It is set to be absorbed by the absorber 330.
  • An upper substrate 340 is disposed on the light absorber 330.
  • a phosphor 370 constituting one subpixel is arranged on the upper substrate 340.
  • the phosphor 370 is formed with the same dimensions as the opening 331 of the light absorber 330. In a direction orthogonal to the upper surface of the light absorber 330, the projection area where the phosphor 370 is projected onto the upper surface of the light absorber 330 and the opening 331 overlap.
  • the thickness d 2 of the upper substrate 340 is varied from 0.1mm to 0.7 mm, were simulated incident efficiency (%).
  • the light incident efficiency (%) is the ratio of the light that has entered the phosphor 370 out of the light that has passed through the opening 331.
  • the light distribution of the light source 310 is an ideal Gaussian distribution.
  • FIG. 5 is a graph showing the relationship between the thickness of the upper substrate and the light incident efficiency for each light source having a different directivity.
  • the vertical axis indicates the light incident efficiency (%)
  • the horizontal axis indicates the thickness d 2 (mm) of the upper substrate.
  • the result of the first light source with the full width at half maximum of the light intensity of 5 ° is a solid line
  • the result of the second light source with the full width at half maximum of the light intensity of 15 ° is a dotted line
  • the full width at half maximum of the light intensity is 27 °.
  • the result of the third light source is indicated by a one-dot chain line
  • the result of the fourth light source having a full width at half maximum of 34 ° is indicated by a two-dot chain line.
  • the light incident efficiency increases as the thickness d 2 of the upper substrate 340 decreases.
  • the light incident efficiency is 53% when the thickness d 2 of the upper substrate 340 is 0.7 mm, whereas the light incident efficiency is when the thickness d 2 of the upper substrate 340 is 0.1 mm. Has improved to 86%.
  • the light incident efficiency is 63.2% when the thickness d 2 of the upper substrate 340 is 0.7 mm, whereas the light incident efficiency is 63.2% when the thickness d 2 of the upper substrate 340 is 0.1 mm.
  • the light efficiency is improved to 88%.
  • the change in the light incident efficiency due to the difference in the thickness d 2 of the upper substrate 340 is small.
  • the full width at half maximum of the light intensity of the light source was changed from 5 ° to 35 °, and the light incident efficiency (%) was simulated.
  • FIG. 6 is a graph showing the relationship between the full width at half maximum of the light intensity of the light source and the light incident efficiency for each thickness of the upper substrate.
  • the vertical axis represents the light incident efficiency (%)
  • the horizontal axis represents the full width at half maximum (°) of the light intensity of the light source.
  • the result when the upper substrate thickness is 0.1 mm is a solid line
  • the result when the upper substrate thickness is 0.25 mm is the dotted line
  • the result when the upper substrate thickness is 0.5 mm Is shown by a one-dot chain line
  • the result when the thickness of the upper substrate is 0.7 mm is shown by a two-dot chain line.
  • the light incident efficiency is 80% or more for a light source having a full width at half maximum of 30 ° or less. If the thickness d 2 of the upper substrate 340 is 0.1 mm or less, the change in the light incident efficiency due to the difference in the full width at half maximum of the light intensity is small.
  • the relationship between the thickness d 2 of the upper substrate 340 and the full width at half maximum of the light intensity of the light source 310 and the light incident efficiency depends on the sizes of the opening 331 and the phosphor 370.
  • the phosphor 370 has a rectangular outer shape composed of a short side and a long side having a length about three times shorter than the short side in a plan view as in this experimental example
  • the thickness d of the upper substrate 340 If 2 is about twice or less the length of the short side of the phosphor 370, the light incident efficiency can be maintained at 80% or more in a light source having a full width at half maximum of light intensity of 30 ° or less.
  • the thickness d 2 of the upper substrate 340 corresponds to the distance D between the lower surface of the phosphor layer 170 and the upper surface of the liquid crystal layer 130. Therefore, when the distance D between the phosphor layer 170 and the liquid crystal layer 130 is not more than twice the short side length L 1 of the pixel phosphors 170R, 170G, 170B, the full width at half maximum of the light intensity is 30 ° or less. The light incident efficiency can be maintained at 80% or more in the light source.
  • the liquid crystal display device 100 having the above-described configuration can display a high-quality image with reduced crosstalk.
  • liquid crystal display device 400 according to the second embodiment is related to the first embodiment only in that the blue phosphor 170B included in the phosphor layer 170 replaces the scatterer 471 and that the blue light is emitted from the light source. Since it is different from the liquid crystal display device 100, description of other configurations will not be repeated.
  • FIG. 7 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 2 of the present invention. In FIG. 7, only a part of the light emitted from the light source is illustrated and indicated by arrows. As shown in FIG. 7, in the liquid crystal display device 400 according to Embodiment 2 of the present invention, an LED that emits blue light is used as the light source 410.
  • the liquid crystal display device 400 includes a phosphor layer 470.
  • the phosphor layer 470 includes two types of pixel phosphors 170R and 170G that absorb blue light emitted from the light source 410 and emit light of different colors, and emit light of a predetermined color for each unit pixel. Specifically, the phosphor layer 470 includes a red phosphor 170R that absorbs blue light and emits red light, and a green phosphor 170G that emits green light. The red phosphor 170R and the green phosphor 170G constitute a plurality of subpixels included in the unit pixel.
  • the phosphor layer 470 includes a scatterer 471 that scatters the blue light emitted from the light source 410.
  • the scatterer 471 constitutes a subpixel included in a unit pixel.
  • the scatterer 471 is configured by dispersing and arranging TiO 2 particles.
  • the scatterer 471 is not limited to this, and may be made of a material exhibiting scattering characteristics such as hollow silica.
  • the light 203, 204, 205 emitted from the light source 410 travels toward the liquid crystal layer 130.
  • the light 203 travels in a direction orthogonal to the liquid crystal layer 130.
  • the light 204 travels obliquely upward to the left in the figure.
  • the light 205 travels diagonally upward to the right in the drawing.
  • Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 470 is absorbed by the pixel phosphors 170R and 170G.
  • the pixel phosphors 170R and 170G that have absorbed light are excited to emit light in their respective colors.
  • the scatterer 471 outputs blue light as scattered light 213, 214, and 215, as shown in FIG.
  • the scattered light 213 travels in a direction orthogonal to the phosphor layer 470.
  • Scattered light 214 travels obliquely upward to the left in the figure.
  • the scattered light 215 travels obliquely upward to the right in the drawing.
  • the sorting filter is provided only at the positions of the pixel phosphors 170R and 170G. In other words, it is desirable that no sorting filter is provided at the position of the scatterer 471.
  • the pseudo white light can be obtained by emitting light from each of the red phosphor 170R, the green phosphor 170G, and the scatterer 471.
  • a phosphor that emits light and a scatterer that outputs a liquid crystal display device 400 having unit pixels that emit any color can be obtained.
  • the blue pixel portion of the phosphor layer 470 may be opened without providing the scatterer 471.
  • liquid crystal display device 400 having the above-described configuration light utilization efficiency can be improved and power consumption can be reduced. Further, the liquid crystal display device 400 having the above configuration can display a high-quality image with reduced crosstalk.
  • liquid crystal display device 500 according to the third embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that the color filter 570 is provided, and thus the description of other configurations will not be repeated.
  • FIG. 8 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 3 of the present invention.
  • the liquid crystal display device 500 according to the third embodiment of the present invention further includes a color filter 570 in which a desired color is arranged as a color emitted from the subpixel.
  • the color filter 570 is located on the opposite side of the phosphor layer 470 from the side facing the liquid crystal layer 130.
  • the red filter portion 570R of the color filter 570 is disposed at the position of the red phosphor 170R.
  • the green filter portion 570G of the color filter 570 is disposed at the position of the green phosphor 170G.
  • the blue filter portion 570B of the color filter 570 is disposed.
  • the black filter portion 570M of the color filter 570 is disposed at the position of the light shielding portion 170M.
  • the color filter 570 By arranging the color filter 570, the light that has passed through the phosphor layer 470 passes through the color filter 570 and is emitted in a desired color. Therefore, when the chromaticity of light emitted from the pixel phosphors 170R and 170G and the scatterer 471 is insufficient as light desired for each subpixel, the chromaticity of the light can be optimized by the color filter 570.
  • liquid crystal display device 500 having the above configuration it is possible to improve light utilization efficiency and reduce power consumption. Further, the liquid crystal display device 500 having the above configuration can display a high-quality image with reduced crosstalk.
  • the liquid crystal display device 600 according to the fourth embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that the shielding layer 680 is provided. Therefore, the description of the other configurations will not be repeated.
  • FIG. 9 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 4 of the present invention.
  • the liquid crystal display device 600 according to the fourth embodiment of the present invention includes subpixels that emit red light and green light on the side opposite to the side facing the liquid crystal layer 130 of the phosphor layer 470.
  • a shielding layer 680 that transmits red light and green light and shields blue light is further provided.
  • the shielding layer 680 is disposed at the positions of the red phosphor 170R and the green phosphor 170G.
  • the shielding layer 680 reflects or absorbs blue light.
  • the shielding layer 680 is composed of a layer containing a yellow pigment, for example.
  • the shielding layer 680 when the light having a wavelength that can excite the pixel phosphors 170R and 170G is included in the external light, the light can be shielded by the shielding layer 680, and thus the pixel phosphors 170R and 170G. Can be suppressed from being excited by the light. Further, it is possible to suppress the deterioration of the pixel phosphors 170R and 170G due to the light.
  • the shielding layer 680 may also be used as a sorting filter.
  • liquid crystal display device 600 having the above-described configuration it is possible to improve light utilization efficiency and reduce power consumption. Further, the liquid crystal display device 600 having the above configuration can display a high-quality image with reduced crosstalk.
  • liquid crystal display device 700 according to the fifth embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that a lens is provided, and thus the description of the other components will not be repeated.
  • FIG. 10 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 5 of the present invention.
  • FIG. 11 is an enlarged view of the lens viewed from the direction of the arrow XI in FIG.
  • FIG. 12 is an enlarged view of the lens of the modification example viewed from the direction of the arrow XII.
  • the liquid crystal display device 700 is located between the first substrate 120 and the light source 410 and collects the light emitted from the light source 410 onto the sub-pixels. 790, 791 are further provided.
  • lenses 790 and 791 are provided on the main surface of the first polarizing plate 150 facing the light source 410.
  • the lenses 790 and 791 have a convex shape on the light source 410 side. Further, the lenses 790 and 791 are formed with the same width as the width of the short side of the subpixel. Further, the lenses 790 and 791 are arranged so as to correspond to all the subpixels.
  • the lens 790 extends in a direction parallel to the long side of the subpixel so as to straddle the plurality of subpixels.
  • the lens 791 is formed with the same length as the long side of the subpixel.
  • FIG. 13 is a partial cross-sectional view schematically showing a state in which light is output from a scatterer by light irradiated from a light source in the liquid crystal display device according to the present embodiment.
  • FIG. 13 only a part of the light emitted from the light source is exemplified and indicated by arrows.
  • light 206, 207, 208 emitted from the light source 410 travels toward the liquid crystal layer 130 while being collected by lenses 790, 791. At this time, the light 206 travels in a direction orthogonal to the liquid crystal layer 130. The light 207 travels diagonally upward to the left in the figure. The light 208 travels obliquely upward to the right in the drawing.
  • Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 470 is absorbed by the pixel phosphors 170R and 170G.
  • the pixel phosphors 170R and 170G that have absorbed light are excited to emit light in their respective colors.
  • the scatterer 471 outputs blue light as scattered light 216, 217, and 218, as shown in FIG.
  • Scattered light 216 travels in a direction orthogonal to phosphor layer 470.
  • Scattered light 217 travels obliquely upward to the left in the figure.
  • Scattered light 218 travels diagonally upward to the right in the drawing.
  • the light use efficiency can be improved.
  • a light source with high directivity is preferably used as the light source 410.
  • liquid crystal display device 700 having the above-described configuration it is possible to improve light utilization efficiency and reduce power consumption.
  • the liquid crystal display device 700 having the above structure can display a high-quality image with reduced crosstalk.
  • liquid crystal display device 110, 310, 410 light source, 120 first substrate, 130 liquid crystal layer, 140 second substrate, 150 first polarizing plate, 160 second polarizing plate, 170, 470 fluorescence Body layer, 170B blue phosphor, 170G green phosphor, 170M light shielding part, 170R red phosphor, 300 light source unit, 320 lower substrate, 330 light absorber, 331 opening, 340 upper substrate, 370 phosphor, 471 scattering Body, 570 color filter, 570B blue filter part, 570G green filter part, 570M black filter part, 570R red filter part, 680 shielding layer, 790, 791 lens.

Abstract

This liquid crystal display device is provided with a liquid crystal layer (130), a first substrate (120), a second substrate (140), and a light source (110). The liquid crystal display device is also provided with: a phosphor layer (170), which includes a plurality of kinds of pixel fluorescent bodies (170R, 170G, 170B), which absorb light emitted from the light source (110) and emit light of different colors, said phosphor layer emitting light of a predetermined color to each unit pixel; a first polarization plate (150); and a second polarization plate (160). The phosphor layer (170) includes light blocking sections (170M), which are positioned in a lattice shape by surrounding the circumference of each of the pixel fluorescent bodies (170R, 170G, 170B). Each of the pixel fluorescent bodies (170R, 170G, 170B) has a rectangular outer shape that is composed of a short side, and a long side having a length three times the length of the short side in planar view. A distance between the phosphor layer (170) and the liquid crystal layer (130) is double the length of the short side of the pixel fluorescent bodies (170R, 170G, 170B) or less.

Description

液晶表示装置Liquid crystal display
　本発明は、液晶表示装置に関し、直下型方式のバックライトを有する液晶表示装置に関する。 The present invention relates to a liquid crystal display device, and more particularly to a liquid crystal display device having a direct type backlight.
　光源からの光を吸収して所定の光を発する蛍光体を含む蛍光体層を備えた液晶表示装置を開示した先行文献として特開２０１０－２５０２５９号公報(特許文献１)がある。特開２０１０－２５０２５９号公報(特許文献１)に記載された液晶表示装置は、液晶層を挟持する一対の基板と、一対の基板の一方側の背面に配置されたバックライト装置と、一対の基板の他方側に形成された偏光板とを備える。 Japanese Patent Application Laid-Open No. 2010-250259 (Patent Document 1) is a prior art document that discloses a liquid crystal display device including a phosphor layer including a phosphor that absorbs light from a light source and emits predetermined light. A liquid crystal display device described in Japanese Patent Application Laid-Open No. 2010-250259 (Patent Document 1) includes a pair of substrates that sandwich a liquid crystal layer, a backlight device disposed on the back surface on one side of the pair of substrates, and a pair of substrates And a polarizing plate formed on the other side of the substrate.
　バックライト装置として、ピーク波長が３８０ｎｍ～４２０ｎｍの範囲にある光を発する発光ダイオードが用いられている。一対の基板の他方側に形成された偏光板の液晶層側とは反対側に、単位ピクセル毎に、ピーク波長が３８０ｎｍ～４２０ｎｍの範囲にある光を吸収して所定の色の光を発する蛍光体層が配置されている。蛍光体層の液晶層側とは反対側の面に、波長４２０ｎｍ以下の波長の光を反射または吸収するフィルター層が形成されている。 A light emitting diode that emits light having a peak wavelength in the range of 380 nm to 420 nm is used as a backlight device. Fluorescence that emits light of a predetermined color by absorbing light having a peak wavelength in the range of 380 nm to 420 nm for each unit pixel on the side opposite to the liquid crystal layer side of the polarizing plate formed on the other side of the pair of substrates. A body layer is arranged. A filter layer that reflects or absorbs light having a wavelength of 420 nm or less is formed on the surface of the phosphor layer opposite to the liquid crystal layer.
特開２０１０－２５０２５９号公報JP 2010-250259 A
　１対の基板のうち液晶層と蛍光体層との間に位置する基板が厚い場合、光源から照射されて液晶層を通過した光が所望のサブピクセルに入射せずにその周囲のサブピクセルに入射することがある。このいわゆるクロストークが発生すると、表示される画像が乱れるとともに、有効に利用される光が減少するため光利用効率が低下する。 When the substrate located between the liquid crystal layer and the phosphor layer is thick among the pair of substrates, the light irradiated from the light source and passed through the liquid crystal layer is not incident on the desired subpixel and is not incident on the surrounding subpixels. May be incident. When this so-called crosstalk occurs, the displayed image is disturbed and the light that is effectively used is reduced, so that the light use efficiency is lowered.
　本発明は上記の問題点に鑑みてなされたものであって、光利用効率を向上して消費電力を低減しつつ高品質の画像を表示できる、液晶表示装置を提供することを目的とする。 The present invention has been made in view of the above problems, and an object of the present invention is to provide a liquid crystal display device capable of displaying a high-quality image while improving light utilization efficiency and reducing power consumption.
　本発明に基づく液晶表示装置は、液晶層と、液晶層を挟んで互いに対向する第１基板および第２基板と、第１基板の液晶層と面する側とは反対側に位置する光源とを備える。また、液晶表示装置は、第２基板の液晶層と面する側とは反対側に位置し、光源から照射される光を吸収してそれぞれ異なる色の光を発する複数種の画素蛍光体を含み、単位ピクセル毎に所定の色の光を発する蛍光体層と、光源と液晶層との間に位置する第１偏光板と、蛍光体層と液晶層との間に位置する第２偏光板とを備える。蛍光体層は、画素蛍光体のそれぞれの周囲を囲んで格子状に位置する遮光部を含む。画素蛍光体の各々は、平面視において、短辺と該短辺の３倍の長さを有する長辺とからなる矩形状の外形を有する。蛍光体層と液晶層との間の距離が画素蛍光体の短辺の長さの２倍以下である。 A liquid crystal display device according to the present invention includes a liquid crystal layer, a first substrate and a second substrate facing each other across the liquid crystal layer, and a light source located on the opposite side of the first substrate facing the liquid crystal layer. Prepare. The liquid crystal display device includes a plurality of types of pixel phosphors that are located on the opposite side of the second substrate facing the liquid crystal layer and that absorb light emitted from the light source and emit light of different colors. A phosphor layer that emits light of a predetermined color for each unit pixel, a first polarizing plate positioned between the light source and the liquid crystal layer, and a second polarizing plate positioned between the phosphor layer and the liquid crystal layer, Is provided. The phosphor layer includes light-shielding portions that are arranged in a grid around each pixel phosphor. Each of the pixel phosphors has a rectangular outer shape composed of a short side and a long side having a length three times the short side in plan view. The distance between the phosphor layer and the liquid crystal layer is not more than twice the length of the short side of the pixel phosphor.
　本発明の一形態においては、光源が、３８０ｎｍ以上４２０ｎｍ以下の範囲にピーク波長を有する可視光を照射する。 In one embodiment of the present invention, the light source emits visible light having a peak wavelength in a range of 380 nm to 420 nm.
　本発明の一形態においては、複数種の画素蛍光体は、単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する、上記可視光を吸収して赤色の光を発する赤色蛍光体と緑色の光を発する緑色蛍光体と青色の光を発する青色蛍光体とを含む。 In one aspect of the present invention, the plurality of types of pixel phosphors include a red phosphor that absorbs visible light and emits red light and green light, each of which constitutes a plurality of subpixels included in a unit pixel. A green phosphor that emits light and a blue phosphor that emits blue light.
　本発明の一形態においては、光源が、青色の光を照射する。
　本発明の一形態においては、複数種の画素蛍光体は、単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する、青色の光を吸収して赤色の光を発する赤色蛍光体と緑色の光を発する緑色蛍光体とを含む。蛍光体層は、単位ピクセルに含まれるサブピクセルを構成する、青色の光を散乱させる散乱体を含む。 In one embodiment of the present invention, the light source emits blue light.
In one aspect of the present invention, the plurality of types of pixel phosphors include a red phosphor that absorbs blue light and emits red light and green light that respectively constitute a plurality of subpixels included in the unit pixel. A green phosphor that emits light. A fluorescent substance layer contains the scatterer which scatters the blue light which comprises the sub pixel contained in a unit pixel.
　本発明の一形態においては、液晶表示装置は、蛍光体層の液晶層と面する側とは反対側に位置し、サブピクセルから発する色として所望される色が配色されたカラーフィルタをさらに備える。 In one embodiment of the present invention, the liquid crystal display device further includes a color filter that is located on the opposite side of the phosphor layer from the side facing the liquid crystal layer and that is arranged with a desired color as a color emitted from the subpixel. .
　本発明の一形態においては、液晶表示装置は、蛍光体層の液晶層と面する側とは反対側において赤色の光および緑色の光を発するサブピクセルの位置に、赤色の光および緑色の光は透過させて青色の光は遮蔽する遮蔽層をさらに備える。 In one embodiment of the present invention, the liquid crystal display device includes red light and green light at a position of a subpixel that emits red light and green light on the side opposite to the side facing the liquid crystal layer of the phosphor layer. Is further provided with a shielding layer that transmits blue light.
　本発明の一形態においては、液晶表示装置は、第１基板と光源との間に位置し、光源から照射された光をサブピクセルに集光させるレンズをさらに備える。 In one embodiment of the present invention, the liquid crystal display device further includes a lens that is positioned between the first substrate and the light source, and that condenses the light emitted from the light source onto the sub-pixels.
　本発明によれば、光利用効率を向上して消費電力を低減しつつ高品質の画像を表示できる。 According to the present invention, it is possible to display a high-quality image while improving light utilization efficiency and reducing power consumption.
本発明の実施形態１に係る液晶表示装置の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 1 of this invention. 図１の液晶表示装置を矢印ＩＩ線矢印方向から見た一部拡大平面図である。FIG. 2 is a partially enlarged plan view of the liquid crystal display device of FIG. 1 as viewed from an arrow II line arrow direction. 同実施形態に係る液晶表示装置において、光源から照射された光により画素蛍光体から光が発する状態を模式的に示す断面図である。FIG. 4 is a cross-sectional view schematically showing a state in which light is emitted from a pixel phosphor by light emitted from a light source in the liquid crystal display device according to the embodiment. シミュレーション用モデルの光源ユニットの構成を示す断面図である。It is sectional drawing which shows the structure of the light source unit of the model for simulation. 上側基板の厚さと入光効率との関係を指向性の異なる光源ごとに示すグラフである。It is a graph which shows the relationship between the thickness of an upper board | substrate, and light-incidence efficiency for every light source from which directivity differs. 光源の光強度の半値全幅と入光効率との関係を上側基板の厚さごとに示すグラフである。It is a graph which shows the relationship between the full width at half maximum of the light intensity of a light source, and light incident efficiency for every thickness of an upper board | substrate. 本発明の実施形態２に係る液晶表示装置の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 2 of this invention. 本発明の実施形態３に係る液晶表示装置の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 3 of this invention. 本発明の実施形態４に係る液晶表示装置の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 4 of this invention. 本発明の実施形態５に係る液晶表示装置の構成を示す断面図である。It is sectional drawing which shows the structure of the liquid crystal display device which concerns on Embodiment 5 of this invention. 図１０の矢印ＸＩ方向からレンズを見た拡大図である。It is the enlarged view which looked at the lens from the arrow XI direction of FIG. 図１０の矢印ＸＩＩ方向から変形例のレンズを見た拡大図である。It is the enlarged view which looked at the lens of the modification from the arrow XII direction of FIG. 同実施形態に係る液晶表示装置において、光源から照射された光により散乱体から光が出力する状態を模式的に示す一部断面図である。In the liquid crystal display device according to the embodiment, it is a partial cross-sectional view schematically showing a state in which light is output from a scatterer by light emitted from a light source.
　以下、本発明の実施形態１に係る液晶表示装置について説明する。以下の実施形態の説明においては、図中の同一または相当部分には同一符号を付して、その説明は繰り返さない。 Hereinafter, the liquid crystal display device according to Embodiment 1 of the present invention will be described. In the following description of the embodiments, the same or corresponding parts in the drawings are denoted by the same reference numerals, and the description thereof will not be repeated.
　(実施形態１)
　図１は、本発明の実施形態１に係る液晶表示装置の構成を示す断面図である。図２は、図１の液晶表示装置を矢印ＩＩ線矢印方向から見た一部拡大平面図である。 (Embodiment 1)
FIG. 1 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 1 of the present invention. FIG. 2 is a partially enlarged plan view of the liquid crystal display device of FIG. 1 viewed from the direction of the arrow II line.
　図１に示すように、本発明の実施形態１に係る液晶表示装置１００は、液晶層１３０と、液晶層１３０を挟んで互いに対向する第１基板１２０および第２基板１４０とを備える。第１基板１２０と第２基板１４０とは、図示しないシール材により貼り合わされている。 As shown in FIG. 1, the liquid crystal display device 100 according to the first embodiment of the present invention includes a liquid crystal layer 130, and a first substrate 120 and a second substrate 140 that face each other with the liquid crystal layer 130 interposed therebetween. The 1st board | substrate 120 and the 2nd board | substrate 140 are bonded together by the sealing material which is not shown in figure.
　第１基板１２０には、図示しないＴＦＴ(Thin　Film　Transistor)および透明電極などが形成されている。第２基板１４０には、図示しない透明電極などが形成されている。第１基板１２０および第２基板１４０は、本実施形態においてはガラス基板で構成されているが、これに限られず、透光性を有し、かつ、液晶を封止できる材料から形成された基板であればよい。 The first substrate 120 is formed with a TFT (Thin Film Transistor) (not shown) and a transparent electrode. A transparent electrode (not shown) is formed on the second substrate 140. In the present embodiment, the first substrate 120 and the second substrate 140 are formed of a glass substrate. However, the first substrate 120 and the second substrate 140 are not limited to this, and are formed of a material having translucency and capable of sealing liquid crystal. If it is.
　また、液晶表示装置１００は、第１基板１２０の液晶層１３０と面する側とは反対側に位置する光源１１０と、第２基板１４０の液晶層１３０と面する側とは反対側に位置し、光源１１０から照射される光を吸収してそれぞれ異なる色の光を発する３種類の画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂを含み、単位ピクセル毎に所定の色の光を発する蛍光体層１７０とを備える。なお、画素蛍光体の種類は４種類以上でもよく、２種類以上であればよい。 In addition, the liquid crystal display device 100 is positioned on the side opposite to the side facing the liquid crystal layer 130 of the second substrate 140 and the light source 110 located on the side opposite to the side facing the liquid crystal layer 130 of the first substrate 120. A phosphor layer 170 that includes three types of pixel phosphors 170R, 170G, and 170B that absorb light emitted from the light source 110 and emit light of different colors, and emit light of a predetermined color for each unit pixel. Prepare. Note that the number of pixel phosphors may be four or more, and may be two or more.
　本実施形態においては、光源１１０として、３８０ｎｍ以上４２０ｎｍ以下の範囲にピーク波長を有する可視光を照射するＬＥＤ(Light　Emitting　Diode)を用いた。ただし、光源が照射する光はこれに限られず、紫外線など蛍光体を励起して発光させることができる光であればよい。また、光源１１０としては、ＬＥＤに限られず、たとえば蛍光管などを用いてもよい。 In this embodiment, an LED (Light Emitting Diode) that emits visible light having a peak wavelength in a range of 380 nm to 420 nm is used as the light source 110. However, the light emitted from the light source is not limited to this, and any light that can excite phosphors such as ultraviolet rays to emit light may be used. Further, the light source 110 is not limited to the LED, and for example, a fluorescent tube may be used.
　複数種の画素蛍光体は、単位ピクセル毎に白色の光または任意の色の光を発するように、上記可視光を吸収して赤色の光を発する赤色蛍光体１７０Ｒと緑色の光を発する緑色蛍光体１７０Ｇと青色の光を発する青色蛍光体１７０Ｂとを含む。赤色蛍光体１７０Ｒと緑色蛍光体１７０Ｇと青色蛍光体１７０Ｂとは、単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する。 The plural types of pixel phosphors absorb the visible light and emit red light so as to emit white light or arbitrary color light for each unit pixel, and green fluorescence that emits green light. Body 170G and blue phosphor 170B emitting blue light. The red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B constitute a plurality of subpixels included in the unit pixel.
　赤色蛍光体１７０Ｒとしては、Ｅｕ付活硫化物系赤色蛍光体を用いた。緑色蛍光体１７０Ｇとしては、Ｅｕ付活硫化物系緑色蛍光体を用いた。青色蛍光体１７０Ｂとしては、Ｅｕ付活燐酸塩系青色蛍光体を用いた。ただし、赤色蛍光体１７０Ｒと緑色蛍光体１７０Ｇと青色蛍光体１７０Ｂとは、上記の材料から構成される場合に限られず、光源１１０からの光を受けて所望の色の光を発する蛍光体から構成されていればよい。 Eu-activated sulfide-based red phosphor was used as the red phosphor 170R. Eu-activated sulfide green phosphor was used as the green phosphor 170G. Eu-activated phosphate blue phosphor was used as the blue phosphor 170B. However, the red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B are not limited to the above-described materials, and are composed of phosphors that emit light of a desired color upon receiving light from the light source 110. It only has to be done.
　液晶表示装置１００は、光源１１０と液晶層１３０との間に位置する第１偏光板１５０と、蛍光体層１７０と液晶層１３０との間に位置する第２偏光板１６０とを備える。 The liquid crystal display device 100 includes a first polarizing plate 150 positioned between the light source 110 and the liquid crystal layer 130 and a second polarizing plate 160 positioned between the phosphor layer 170 and the liquid crystal layer 130.
　本実施形態においては、第１偏光板１５０は、第１基板１２０と光源１１０との間に位置しているが、この位置に限られず、第１基板１２０と液晶層１３０との間に位置してもよい。 In the present embodiment, the first polarizing plate 150 is located between the first substrate 120 and the light source 110, but is not limited to this position, and is located between the first substrate 120 and the liquid crystal layer 130. May be.
　第２偏光板１６０は、第２基板１４０と蛍光体層１７０との間に位置しているが、この位置に限られず、液晶層１３０と第２基板１４０との間に位置してもよい。 The second polarizing plate 160 is located between the second substrate 140 and the phosphor layer 170, but is not limited to this position, and may be located between the liquid crystal layer 130 and the second substrate 140.
　図２に示すように、蛍光体層１７０は、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂのそれぞれの周囲を囲んで格子状に位置する遮光部１７０Ｍを含む。画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂの各々は、平面視において、短辺と該短辺の３倍の長さを有する長辺とからなる矩形状の外形を有している。本実施形態においては、長辺の長さＬ2が短辺の長さＬ1の約３倍である。 As shown in FIG. 2, the phosphor layer 170 includes light-shielding portions 170 </ b> M that are arranged in a grid surrounding each of the pixel phosphors 170 </ b> R, 170 </ b> G, and 170 </ b> B. Each of the pixel phosphors 170R, 170G, and 170B has a rectangular outer shape that includes a short side and a long side that is three times as long as the short side in plan view. In the present embodiment, the long side length L 2 is about three times the short side length L 1 .
　本実施形態においては、蛍光体層１７０と液晶層１３０との間の距離Ｄが、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂの各々の短辺の長さＬ1の２倍以下となるように、第２基板１４０の厚さが決定されている。 In the present embodiment, the distance D between the phosphor layer 170 and the liquid crystal layer 130 is not more than twice the short side length L 1 of each of the pixel phosphors 170R, 170G, and 170B. The thickness of the two substrates 140 is determined.
　図３は、本実施形態に係る液晶表示装置において、光源から照射された光により画素蛍光体から光が発する状態を模式的に示す断面図である。図３においては、光源から照射された光のうちの一部のみを例示して矢印で示している。 FIG. 3 is a cross-sectional view schematically showing a state in which light is emitted from the pixel phosphor by the light emitted from the light source in the liquid crystal display device according to the present embodiment. In FIG. 3, only a part of the light emitted from the light source is exemplified and indicated by arrows.
　図３に示すように、光源１１０から照射された光２００，２０１，２０２は、液晶層１３０に向かって進行する。このとき、光２００は、液晶層１３０に対して直交する方向に進行する。光２０１は、図中の左斜め上方に向けて進行する。光２０２は、図中の右斜め上方に向けて進行する。 As shown in FIG. 3, the light 200, 201, 202 emitted from the light source 110 travels toward the liquid crystal layer 130. At this time, the light 200 travels in a direction orthogonal to the liquid crystal layer 130. The light 201 travels diagonally upward to the left in the figure. The light 202 travels diagonally upward to the right in the figure.
　液晶層１３０を通過して蛍光体層１７０に入射した光の一部は、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂに吸収される。光を吸収した画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂは、励起してそれぞれの色で発光する。 Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 170 is absorbed by the pixel phosphors 170R, 170G, and 170B. The pixel phosphors 170R, 170G, and 170B that have absorbed the light are excited to emit light in their respective colors.
　たとえば、赤色蛍光体１７０Ｒは、図３に示すように、赤色の光２１０，２１１，２１２を発する。赤色蛍光体１７０Ｒから発光する光は散乱光である。光２１０は蛍光体層１７０に対して直交する方向に進行する。光２１１は、図中の左斜め上方に向けて進行する。光２１２は、図中の右斜め上方に向けて進行する。 For example, the red phosphor 170R emits red light 210, 211, 212 as shown in FIG. The light emitted from the red phosphor 170R is scattered light. The light 210 travels in a direction orthogonal to the phosphor layer 170. The light 211 travels obliquely upward to the left in the figure. The light 212 travels obliquely upward to the right in the drawing.
　液晶層１３０を通過して蛍光体層１７０に入射した光のうち、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂに吸収されなかった光は、蛍光体層１７０の液晶層１３０と面する側とは反対側に位置する、図示しない選別フィルターにより吸収されることが望ましい。選別フィルターを設けることは必須ではない。なお、選別フィルターは、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂから発せられた光は吸収しない。また、選別フィルターは、後述するカラーフィルタによって代用することが可能である。 Of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 170, the light that has not been absorbed by the pixel phosphors 170R, 170G, and 170B is the opposite side of the phosphor layer 170 that faces the liquid crystal layer 130. It is desirable to be absorbed by a sorting filter (not shown) located in the area. It is not essential to provide a sorting filter. Note that the sorting filter does not absorb light emitted from the pixel phosphors 170R, 170G, and 170B. The sorting filter can be replaced by a color filter described later.
　赤色蛍光体１７０Ｒ、緑色蛍光体１７０Ｇおよび青色蛍光体１７０Ｂの各々から光が発せられることにより、擬似的に白色光を得ることができる。また、発光する蛍光体を選択することにより、任意の色を発する単位ピクセルを有する液晶表示装置１００を得ることができる。 A pseudo white light can be obtained by emitting light from each of the red phosphor 170R, the green phosphor 170G, and the blue phosphor 170B. Further, by selecting a phosphor that emits light, the liquid crystal display device 100 having unit pixels that emit an arbitrary color can be obtained.
　以下、蛍光体層１７０と液晶層１３０との間の距離Ｄを、画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂの各々の短辺の長さＬ1の２倍以下にすることにより、液晶表示装置１００の光の利用効率を高く維持できることを示すシミュレーション結果について説明する。 Hereinafter, the distance D between the phosphor layer 170 and the liquid crystal layer 130 is set to be not more than twice the short side length L 1 of each of the pixel phosphors 170R, 170G, and 170B. A simulation result indicating that the light use efficiency can be maintained high will be described.
　図４は、シミュレーション用モデルの光源ユニットの構成を示す断面図である。図４に示すように、シミュレーション用モデルの光源ユニット３００は、光源３１０と、下側基板３２０と、光吸収体３３０と、上側基板３４０と、蛍光体３７０とを備えている。 FIG. 4 is a cross-sectional view showing the configuration of the light source unit of the simulation model. As shown in FIG. 4, the simulation model light source unit 300 includes a light source 310, a lower substrate 320, a light absorber 330, an upper substrate 340, and a phosphor 370.
　光源３１０としては、指向性の異なる光源を４つ設定した。第１の光源の光強度の半値全幅は、５°である。第２の光源の光強度の半値全幅は、１５°である。第３の光源の光強度の半値全幅は、２７°である。第４の光源の光強度の半値全幅は、３４°である。第１から第４まで順に、光源３１０の指向性が低くなっている。 As the light source 310, four light sources having different directivities were set. The full width at half maximum of the light intensity of the first light source is 5 °. The full width at half maximum of the light intensity of the second light source is 15 °. The full width at half maximum of the light intensity of the third light source is 27 °. The full width at half maximum of the light intensity of the fourth light source is 34 °. The directivity of the light source 310 decreases in order from the first to the fourth.
　下側基板３２０は、光源３１０から所定の間隔を置いて配置されている。下側基板３２０の厚さｄ1は、０．５ｍｍとした。下側基板３２０上に、開口部３３１を有する光吸収体３３０が配置されている。 The lower substrate 320 is disposed at a predetermined interval from the light source 310. The thickness d 1 of the lower substrate 320 was 0.5 mm. A light absorber 330 having an opening 331 is disposed on the lower substrate 320.
　光吸収体３３０は、平面視において、０．１２ｍｍ×０．３８ｍｍの開口部３３１を有しており、光源３１０から照射された光のうち、開口部３３１を通過する光以外の光は全て光吸収体３３０に吸収されるように設定されている。光吸収体３３０上に、上側基板３４０が配置されている。 The light absorber 330 has an opening 331 of 0.12 mm × 0.38 mm in plan view, and all of the light emitted from the light source 310 other than the light passing through the opening 331 is light. It is set to be absorbed by the absorber 330. An upper substrate 340 is disposed on the light absorber 330.
　上側基板３４０上に、１つのサブピクセルを構成する蛍光体３７０が配置されている。蛍光体３７０は、光吸収体３３０の開口部３３１と同一の寸法で形成されている。光吸収体３３０の上面と直交する方向において、蛍光体３７０を光吸収体３３０の上面に投影した投影領域と開口部３３１とは重なっている。 On the upper substrate 340, a phosphor 370 constituting one subpixel is arranged. The phosphor 370 is formed with the same dimensions as the opening 331 of the light absorber 330. In a direction orthogonal to the upper surface of the light absorber 330, the projection area where the phosphor 370 is projected onto the upper surface of the light absorber 330 and the opening 331 overlap.
　上記の光源ユニット３００において、上側基板３４０の厚さｄ2を０．１ｍｍから０．７ｍｍまで変化させて、入光効率(％)をシミュレーションした。なお、入光効率(％)とは、開口部３３１を通過した光のうち、蛍光体３７０に入射した光の割合である。光源３１０の配光分布は、理想的なガウス分布とした。 In the light source unit 300, the thickness d 2 of the upper substrate 340 is varied from 0.1mm to 0.7 mm, were simulated incident efficiency (%). The light incident efficiency (%) is the ratio of the light that has entered the phosphor 370 out of the light that has passed through the opening 331. The light distribution of the light source 310 is an ideal Gaussian distribution.
　図５は、上側基板の厚さと入光効率との関係を指向性の異なる光源ごとに示すグラフである。図５においては、縦軸に入光効率(％)、横軸に上側基板の厚さｄ2(ｍｍ)を示している。 FIG. 5 is a graph showing the relationship between the thickness of the upper substrate and the light incident efficiency for each light source having a different directivity. In FIG. 5, the vertical axis indicates the light incident efficiency (%), and the horizontal axis indicates the thickness d 2 (mm) of the upper substrate.
　光強度の半値全幅が５°である第１の光源の結果を実線で、光強度の半値全幅が１５°である第２の光源の結果を点線で、光強度の半値全幅が２７°である第３の光源の結果を１点鎖線で、光強度の半値全幅が３４°である第４の光源の結果を２点鎖線で示している。 The result of the first light source with the full width at half maximum of the light intensity of 5 ° is a solid line, the result of the second light source with the full width at half maximum of the light intensity of 15 ° is a dotted line, and the full width at half maximum of the light intensity is 27 °. The result of the third light source is indicated by a one-dot chain line, and the result of the fourth light source having a full width at half maximum of 34 ° is indicated by a two-dot chain line.
　図５に示すように、指向性の低い第３の光源および第４の光源では、上側基板３４０の厚さｄ2が薄くなるに従って、入光効率(％)が高くなる。第４の光源では、上側基板３４０の厚さｄ2が０．７ｍｍのとき入光効率が５３％であるのに対して、上側基板３４０の厚さｄ2が０．１ｍｍのとき入光効率は８６％まで向上している。 As shown in FIG. 5, in the third light source and the fourth light source with low directivity, the light incident efficiency (%) increases as the thickness d 2 of the upper substrate 340 decreases. In the fourth light source, the light incident efficiency is 53% when the thickness d 2 of the upper substrate 340 is 0.7 mm, whereas the light incident efficiency is when the thickness d 2 of the upper substrate 340 is 0.1 mm. Has improved to 86%.
　第３の光源では、上側基板３４０の厚さｄ2が０．７ｍｍのとき入光効率が６３．２％であるのに対して、上側基板３４０の厚さｄ2が０．１ｍｍのとき入光効率は８８％まで向上している。指向性の高い第１の光源および第２の光源では、上側基板３４０の厚さｄ2の違いによる入光効率の変化は小さい。 In the third light source, the light incident efficiency is 63.2% when the thickness d 2 of the upper substrate 340 is 0.7 mm, whereas the light incident efficiency is 63.2% when the thickness d 2 of the upper substrate 340 is 0.1 mm. The light efficiency is improved to 88%. In the first light source and the second light source with high directivity, the change in the light incident efficiency due to the difference in the thickness d 2 of the upper substrate 340 is small.
　次に、上記の光源ユニット３００において、光源の光強度の半値全幅を５°から３５°まで変化させて、入光効率(％)をシミュレーションした。 Next, in the light source unit 300 described above, the full width at half maximum of the light intensity of the light source was changed from 5 ° to 35 °, and the light incident efficiency (%) was simulated.
　図６は、光源の光強度の半値全幅と入光効率との関係を上側基板の厚さごとに示すグラフである。図６においては、縦軸に入光効率(％)、横軸に光源の光強度の半値全幅(°)を示している。 FIG. 6 is a graph showing the relationship between the full width at half maximum of the light intensity of the light source and the light incident efficiency for each thickness of the upper substrate. In FIG. 6, the vertical axis represents the light incident efficiency (%), and the horizontal axis represents the full width at half maximum (°) of the light intensity of the light source.
　上側基板の厚さが０．１ｍｍであるときの結果を実線で、上側基板の厚さが０．２５ｍｍであるときの結果を点線で、上側基板の厚さが０．５ｍｍであるときの結果を一点鎖線で、上側基板の厚さが０．７ｍｍであるときの結果を２点鎖線で示している。 The result when the upper substrate thickness is 0.1 mm is a solid line, the result when the upper substrate thickness is 0.25 mm is the dotted line, and the result when the upper substrate thickness is 0.5 mm Is shown by a one-dot chain line, and the result when the thickness of the upper substrate is 0.7 mm is shown by a two-dot chain line.
　図６に示すように、上側基板３４０の厚さｄ2が０．２５ｍｍ以下であれば、光強度の半値全幅が３０°以下の光源では入光効率が８０％以上である。上側基板３４０の厚さｄ2が０．１ｍｍ以下であれば、光強度の半値全幅の違いによる入光効率の変化は小さい。 As shown in FIG. 6, when the thickness d 2 of the upper substrate 340 is 0.25 mm or less, the light incident efficiency is 80% or more for a light source having a full width at half maximum of 30 ° or less. If the thickness d 2 of the upper substrate 340 is 0.1 mm or less, the change in the light incident efficiency due to the difference in the full width at half maximum of the light intensity is small.
　上側基板３４０の厚さｄ2および光源３１０の光強度の半値全幅と入光効率との関係は、開口部３３１および蛍光体３７０の大きさに依存する。本実験例のように、蛍光体３７０が、平面視において、短辺と短辺の約３倍の長さを有する長辺とからなる矩形状の外形を有する場合、上側基板３４０の厚さｄ2が蛍光体３７０の短辺の長さの約２倍以下であれば、光強度の半値全幅が３０°以下である光源において入光効率を８０％以上維持することができる。 The relationship between the thickness d 2 of the upper substrate 340 and the full width at half maximum of the light intensity of the light source 310 and the light incident efficiency depends on the sizes of the opening 331 and the phosphor 370. When the phosphor 370 has a rectangular outer shape composed of a short side and a long side having a length about three times shorter than the short side in a plan view as in this experimental example, the thickness d of the upper substrate 340 If 2 is about twice or less the length of the short side of the phosphor 370, the light incident efficiency can be maintained at 80% or more in a light source having a full width at half maximum of light intensity of 30 ° or less.
　液晶表示装置１００においては、上側基板３４０の厚さｄ2は、蛍光体層１７０の下面と液晶層１３０の上面との間の距離Ｄに相当する。そのため、蛍光体層１７０と液晶層１３０との間の距離Ｄが画素蛍光体１７０Ｒ，１７０Ｇ，１７０Ｂの短辺の長さＬ1の２倍以下である場合、光強度の半値全幅が３０°以下である光源において入光効率を８０％以上維持することができる。 In the liquid crystal display device 100, the thickness d 2 of the upper substrate 340 corresponds to the distance D between the lower surface of the phosphor layer 170 and the upper surface of the liquid crystal layer 130. Therefore, when the distance D between the phosphor layer 170 and the liquid crystal layer 130 is not more than twice the short side length L 1 of the pixel phosphors 170R, 170G, 170B, the full width at half maximum of the light intensity is 30 ° or less. The light incident efficiency can be maintained at 80% or more in the light source.
　よって、上記の構成を有する液晶表示装置１００では、光利用効率を向上して消費電力を低減することができる。また、上記の構成を有する液晶表示装置１００は、クロストークを低減して高品質の画像を表示できる。 Therefore, in the liquid crystal display device 100 having the above-described configuration, light utilization efficiency can be improved and power consumption can be reduced. Further, the liquid crystal display device 100 having the above configuration can display a high-quality image with reduced crosstalk.
　以下、本発明の実施形態２に係る液晶表示装置について説明する。なお、実施形態２に係る液晶表示装置４００は、蛍光体層１７０に含まれる青色蛍光体１７０Ｂが散乱体４７１に代わる点、および、光源から青色の光が照射される点のみ実施形態１に係る液晶表示装置１００と異なるため、他の構成については説明を繰り返さない。 Hereinafter, a liquid crystal display device according to Embodiment 2 of the present invention will be described. Note that the liquid crystal display device 400 according to the second embodiment is related to the first embodiment only in that the blue phosphor 170B included in the phosphor layer 170 replaces the scatterer 471 and that the blue light is emitted from the light source. Since it is different from the liquid crystal display device 100, description of other configurations will not be repeated.
　(実施形態２)
　図７は、本発明の実施形態２に係る液晶表示装置の構成を示す断面図である。図７においては、光源から照射された光のうちの一部のみを例示して矢印で示している。図７に示すように、本発明の実施形態２に係る液晶表示装置４００においては、光源４１０として、青色の光を照射するＬＥＤを用いた。液晶表示装置４００は、蛍光体層４７０を備えている。 (Embodiment 2)
FIG. 7 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 2 of the present invention. In FIG. 7, only a part of the light emitted from the light source is illustrated and indicated by arrows. As shown in FIG. 7, in the liquid crystal display device 400 according to Embodiment 2 of the present invention, an LED that emits blue light is used as the light source 410. The liquid crystal display device 400 includes a phosphor layer 470.
　蛍光体層４７０は、光源４１０から照射される青色の光を吸収してそれぞれ異なる色の光を発する２種類の画素蛍光体１７０Ｒ，１７０Ｇを含み、単位ピクセル毎に所定の色の光を発する。具体的には、蛍光体層４７０は、青色の光を吸収して赤色の光を発する赤色蛍光体１７０Ｒと、緑色の光を発する緑色蛍光体１７０Ｇとを含む。赤色蛍光体１７０Ｒおよび緑色蛍光体１７０Ｇは、単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する。 The phosphor layer 470 includes two types of pixel phosphors 170R and 170G that absorb blue light emitted from the light source 410 and emit light of different colors, and emit light of a predetermined color for each unit pixel. Specifically, the phosphor layer 470 includes a red phosphor 170R that absorbs blue light and emits red light, and a green phosphor 170G that emits green light. The red phosphor 170R and the green phosphor 170G constitute a plurality of subpixels included in the unit pixel.
　また、蛍光体層４７０は、光源４１０から照射された青色の光を散乱させる散乱体４７１を含む。散乱体４７１は、単位ピクセルに含まれるサブピクセルを構成する。本実施形態においては、散乱体４７１は、ＴｉＯ2粒子が分散配置されて構成されている。散乱体４７１は、これに限られず、たとえば中空シリカなど散乱特性を示す材料から構成されていればよい。 The phosphor layer 470 includes a scatterer 471 that scatters the blue light emitted from the light source 410. The scatterer 471 constitutes a subpixel included in a unit pixel. In the present embodiment, the scatterer 471 is configured by dispersing and arranging TiO 2 particles. The scatterer 471 is not limited to this, and may be made of a material exhibiting scattering characteristics such as hollow silica.
　図７に示すように、光源４１０から照射された光２０３，２０４，２０５は、液晶層１３０に向かって進行する。このとき、光２０３は、液晶層１３０に対して直交する方向に進行する。光２０４は、図中の左斜め上方に向けて進行する。光２０５は、図中の右斜め上方に向けて進行する。 As shown in FIG. 7, the light 203, 204, 205 emitted from the light source 410 travels toward the liquid crystal layer 130. At this time, the light 203 travels in a direction orthogonal to the liquid crystal layer 130. The light 204 travels obliquely upward to the left in the figure. The light 205 travels diagonally upward to the right in the drawing.
　液晶層１３０を通過して蛍光体層４７０に入射した光の一部は、画素蛍光体１７０Ｒ，１７０Ｇに吸収される。光を吸収した画素蛍光体１７０Ｒ，１７０Ｇは、励起してそれぞれの色で発光する。 Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 470 is absorbed by the pixel phosphors 170R and 170G. The pixel phosphors 170R and 170G that have absorbed light are excited to emit light in their respective colors.
　液晶層１３０を通過して散乱体４７１に入射した光の一部は、散乱体４７１により散乱される。たとえば、散乱体４７１は、図７に示すように、散乱光２１３，２１４，２１５として青色の光を出力する。散乱光２１３は蛍光体層４７０に対して直交する方向に進行する。散乱光２１４は、図中の左斜め上方に向けて進行する。散乱光２１５は、図中の右斜め上方に向けて進行する。 Part of the light that has passed through the liquid crystal layer 130 and entered the scatterer 471 is scattered by the scatterer 471. For example, the scatterer 471 outputs blue light as scattered light 213, 214, and 215, as shown in FIG. The scattered light 213 travels in a direction orthogonal to the phosphor layer 470. Scattered light 214 travels obliquely upward to the left in the figure. The scattered light 215 travels obliquely upward to the right in the drawing.
　本実施形態においては、選別フィルターが画素蛍光体１７０Ｒ，１７０Ｇの位置にのみ設けられていることが望ましい。言い換えると、散乱体４７１の位置には、選別フィルターが設けられていないことが望ましい。 In this embodiment, it is desirable that the sorting filter is provided only at the positions of the pixel phosphors 170R and 170G. In other words, it is desirable that no sorting filter is provided at the position of the scatterer 471.
　赤色蛍光体１７０Ｒ、緑色蛍光体１７０Ｇおよび散乱体４７１の各々から光が発せられることにより、擬似的に白色光を得ることができる。また、発光する蛍光体および出力する散乱体を選択することにより、任意の色を発する単位ピクセルを有する液晶表示装置４００を得ることができる。 The pseudo white light can be obtained by emitting light from each of the red phosphor 170R, the green phosphor 170G, and the scatterer 471. In addition, by selecting a phosphor that emits light and a scatterer that outputs, a liquid crystal display device 400 having unit pixels that emit any color can be obtained.
　なお、光源４１０から照射される光が完全散乱光である場合、散乱体４７１を設けずに、蛍光体層４７０の青色画素部分を開口にしてもよい。 If the light emitted from the light source 410 is completely scattered light, the blue pixel portion of the phosphor layer 470 may be opened without providing the scatterer 471.
　上記の構成を有する液晶表示装置４００においても、光利用効率を向上して消費電力を低減することができる。また、上記の構成を有する液晶表示装置４００は、クロストークを低減して高品質の画像を表示できる。 Also in the liquid crystal display device 400 having the above-described configuration, light utilization efficiency can be improved and power consumption can be reduced. Further, the liquid crystal display device 400 having the above configuration can display a high-quality image with reduced crosstalk.
　以下、本発明の実施形態３に係る液晶表示装置について説明する。なお、実施形態３に係る液晶表示装置５００は、カラーフィルタ５７０を備えている点のみ実施形態２に係る液晶表示装置４００と異なるため、他の構成については説明を繰り返さない。 Hereinafter, a liquid crystal display device according to Embodiment 3 of the present invention will be described. Note that the liquid crystal display device 500 according to the third embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that the color filter 570 is provided, and thus the description of other configurations will not be repeated.
　(実施形態３)
　図８は、本発明の実施形態３に係る液晶表示装置の構成を示す断面図である。図８に示すように、本発明の実施形態３に係る液晶表示装置５００は、サブピクセルから発する色として所望される色が配色されたカラーフィルタ５７０をさらに備える。カラーフィルタ５７０は、蛍光体層４７０の液晶層１３０と面する側とは反対側に位置している。 (Embodiment 3)
FIG. 8 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 3 of the present invention. As shown in FIG. 8, the liquid crystal display device 500 according to the third embodiment of the present invention further includes a color filter 570 in which a desired color is arranged as a color emitted from the subpixel. The color filter 570 is located on the opposite side of the phosphor layer 470 from the side facing the liquid crystal layer 130.
　具体的には、赤色蛍光体１７０Ｒの位置に、カラーフィルタ５７０の赤色フィルタ部５７０Ｒが配置されている。緑色蛍光体１７０Ｇの位置に、カラーフィルタ５７０の緑色フィルタ部５７０Ｇが配置されている。散乱体４７１の位置に、カラーフィルタ５７０の青色フィルタ部５７０Ｂが配置されている。遮光部１７０Ｍの位置に、カラーフィルタ５７０の黒色フィルタ部５７０Ｍが配置されている。 Specifically, the red filter portion 570R of the color filter 570 is disposed at the position of the red phosphor 170R. The green filter portion 570G of the color filter 570 is disposed at the position of the green phosphor 170G. At the position of the scatterer 471, the blue filter portion 570B of the color filter 570 is disposed. The black filter portion 570M of the color filter 570 is disposed at the position of the light shielding portion 170M.
　カラーフィルタ５７０を配置することにより、蛍光体層４７０を通過した光は、カラーフィルタ５７０を通過して所望される色となって出射する。そのため、画素蛍光体１７０Ｒ，１７０Ｇおよび散乱体４７１から発する光の色度が各サブピクセルに所望される光として不十分である場合、カラーフィルタ５７０によりその光の色度を最適化できる。 By arranging the color filter 570, the light that has passed through the phosphor layer 470 passes through the color filter 570 and is emitted in a desired color. Therefore, when the chromaticity of light emitted from the pixel phosphors 170R and 170G and the scatterer 471 is insufficient as light desired for each subpixel, the chromaticity of the light can be optimized by the color filter 570.
　上記の構成を有する液晶表示装置５００においても、光利用効率を向上して消費電力を低減することができる。また、上記の構成を有する液晶表示装置５００は、クロストークを低減して高品質の画像を表示できる。 Also in the liquid crystal display device 500 having the above configuration, it is possible to improve light utilization efficiency and reduce power consumption. Further, the liquid crystal display device 500 having the above configuration can display a high-quality image with reduced crosstalk.
　以下、本発明の実施形態４に係る液晶表示装置について説明する。なお、実施形態４に係る液晶表示装置６００は、遮蔽層６８０を備える点のみ実施形態２に係る液晶表示装置４００と異なるため、他の構成については説明を繰り返さない。 Hereinafter, a liquid crystal display device according to Embodiment 4 of the present invention will be described. The liquid crystal display device 600 according to the fourth embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that the shielding layer 680 is provided. Therefore, the description of the other configurations will not be repeated.
　(実施形態４)
　図９は、本発明の実施形態４に係る液晶表示装置の構成を示す断面図である。図９に示すように、本発明の実施形態４に係る液晶表示装置６００は、蛍光体層４７０の液晶層１３０と面する側とは反対側において赤色の光および緑色の光を発するサブピクセルの位置に、赤色の光および緑色の光は透過させて青色の光は遮蔽する遮蔽層６８０をさらに備える。 (Embodiment 4)
FIG. 9 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 4 of the present invention. As shown in FIG. 9, the liquid crystal display device 600 according to the fourth embodiment of the present invention includes subpixels that emit red light and green light on the side opposite to the side facing the liquid crystal layer 130 of the phosphor layer 470. In the position, a shielding layer 680 that transmits red light and green light and shields blue light is further provided.
　具体的には、赤色蛍光体１７０Ｒおよび緑色蛍光体１７０Ｇの位置に、遮蔽層６８０が配置されている。遮蔽層６８０は、青色の光を反射または吸収する。遮蔽層６８０は、たとえば、黄色顔料を含む層から構成されている。 Specifically, the shielding layer 680 is disposed at the positions of the red phosphor 170R and the green phosphor 170G. The shielding layer 680 reflects or absorbs blue light. The shielding layer 680 is composed of a layer containing a yellow pigment, for example.
　遮蔽層６８０を配置することにより、外光に画素蛍光体１７０Ｒ，１７０Ｇを励起可能な波長の光が含まれている場合に、遮蔽層６８０でその光を遮蔽できるため、画素蛍光体１７０Ｒ，１７０Ｇがその光によって励起されることを抑制できる。また、その光によって画素蛍光体１７０Ｒ，１７０Ｇが劣化することも抑制できる。なお、遮蔽層６８０を選別フィルターと兼用してもよい。 By disposing the shielding layer 680, when the light having a wavelength that can excite the pixel phosphors 170R and 170G is included in the external light, the light can be shielded by the shielding layer 680, and thus the pixel phosphors 170R and 170G. Can be suppressed from being excited by the light. Further, it is possible to suppress the deterioration of the pixel phosphors 170R and 170G due to the light. Note that the shielding layer 680 may also be used as a sorting filter.
　上記の構成を有する液晶表示装置６００においても、光利用効率を向上して消費電力を低減することができる。また、上記の構成を有する液晶表示装置６００は、クロストークを低減して高品質の画像を表示できる。 Also in the liquid crystal display device 600 having the above-described configuration, it is possible to improve light utilization efficiency and reduce power consumption. Further, the liquid crystal display device 600 having the above configuration can display a high-quality image with reduced crosstalk.
　以下、本発明の実施形態５に係る液晶表示装置について説明する。なお、実施形態５に係る液晶表示装置７００は、レンズを備える点のみ実施形態２に係る液晶表示装置４００と異なるため、他の構成については説明を繰り返さない。 Hereinafter, a liquid crystal display device according to Embodiment 5 of the present invention will be described. Note that the liquid crystal display device 700 according to the fifth embodiment is different from the liquid crystal display device 400 according to the second embodiment only in that a lens is provided, and thus the description of the other components will not be repeated.
　(実施形態５)
　図１０は、本発明の実施形態５に係る液晶表示装置の構成を示す断面図である。図１１は、図１０の矢印ＸＩ方向からレンズを見た拡大図である。図１２は、矢印ＸＩＩ方向から変形例のレンズを見た拡大図である。 (Embodiment 5)
FIG. 10 is a cross-sectional view showing a configuration of a liquid crystal display device according to Embodiment 5 of the present invention. FIG. 11 is an enlarged view of the lens viewed from the direction of the arrow XI in FIG. FIG. 12 is an enlarged view of the lens of the modification example viewed from the direction of the arrow XII.
　図１０に示すように、本発明の実施形態５に係る液晶表示装置７００は、第１基板１２０と光源４１０との間に位置し、光源４１０から照射された光をサブピクセルに集光させるレンズ７９０，７９１をさらに備える。 As shown in FIG. 10, the liquid crystal display device 700 according to the fifth embodiment of the present invention is located between the first substrate 120 and the light source 410 and collects the light emitted from the light source 410 onto the sub-pixels. 790, 791 are further provided.
　本実施形態においては、第１偏光板１５０の光源４１０と面する側の主面にレンズ７９０，７９１が設けられている。レンズ７９０，７９１は、光源４１０側に凸状の形状を有している。また、レンズ７９０，７９１は、サブピクセルの短辺の幅と同一の幅で形成されている。さらに、レンズ７９０，７９１は、全てのサブピクセルに対応するように配置されている。 In the present embodiment, lenses 790 and 791 are provided on the main surface of the first polarizing plate 150 facing the light source 410. The lenses 790 and 791 have a convex shape on the light source 410 side. Further, the lenses 790 and 791 are formed with the same width as the width of the short side of the subpixel. Further, the lenses 790 and 791 are arranged so as to correspond to all the subpixels.
　図１１に示すように、本実施形態においては、レンズ７９０は、複数のサブピクセルに跨るようにサブピクセルの長辺に平行な方向に延在している。本実施形態の変形例においては、図１２に示すように、レンズ７９１は、サブピクセルの長辺の長さと同一の長さで形成されている。 As shown in FIG. 11, in the present embodiment, the lens 790 extends in a direction parallel to the long side of the subpixel so as to straddle the plurality of subpixels. In the modification of this embodiment, as shown in FIG. 12, the lens 791 is formed with the same length as the long side of the subpixel.
　図１３は、本実施形態に係る液晶表示装置において、光源から照射された光により散乱体から光が出力する状態を模式的に示す一部断面図である。図１３においては、光源から照射された光のうちの一部のみを例示して矢印で示している。 FIG. 13 is a partial cross-sectional view schematically showing a state in which light is output from a scatterer by light irradiated from a light source in the liquid crystal display device according to the present embodiment. In FIG. 13, only a part of the light emitted from the light source is exemplified and indicated by arrows.
　図１３に示すように、光源４１０から照射された光２０６，２０７，２０８は、レンズ７９０，７９１によって集光されつつ液晶層１３０に向かって進行する。このとき、光２０６は、液晶層１３０に対して直交する方向に進行する。光２０７は、図中の左斜め上方に向けて進行する。光２０８は、図中の右斜め上方に向けて進行する。 As shown in FIG. 13, light 206, 207, 208 emitted from the light source 410 travels toward the liquid crystal layer 130 while being collected by lenses 790, 791. At this time, the light 206 travels in a direction orthogonal to the liquid crystal layer 130. The light 207 travels diagonally upward to the left in the figure. The light 208 travels obliquely upward to the right in the drawing.
　液晶層１３０を通過して蛍光体層４７０に入射した光の一部は、画素蛍光体１７０Ｒ，１７０Ｇに吸収される。光を吸収した画素蛍光体１７０Ｒ，１７０Ｇは、励起してそれぞれの色で発光する。 Part of the light that has passed through the liquid crystal layer 130 and entered the phosphor layer 470 is absorbed by the pixel phosphors 170R and 170G. The pixel phosphors 170R and 170G that have absorbed light are excited to emit light in their respective colors.
　液晶層１３０を通過して散乱体４７１に入射した光の一部は、散乱体４７１により散乱される。たとえば、散乱体４７１は、図１３に示すように、散乱光２１６，２１７，２１８として青色の光を出力する。散乱光２１６は蛍光体層４７０に対して直交する方向に進行する。散乱光２１７は、図中の左斜め上方に向けて進行する。散乱光２１８は、図中の右斜め上方に向けて進行する。 Part of the light that has passed through the liquid crystal layer 130 and entered the scatterer 471 is scattered by the scatterer 471. For example, the scatterer 471 outputs blue light as scattered light 216, 217, and 218, as shown in FIG. Scattered light 216 travels in a direction orthogonal to phosphor layer 470. Scattered light 217 travels obliquely upward to the left in the figure. Scattered light 218 travels diagonally upward to the right in the drawing.
　本実施形態においては、サブピクセルに光源４１０から照射された光を集光できるため、光の利用効率を向上することができる。なお、光源４１０として、指向性の高い光源を用いることが好ましい。 In this embodiment, since the light emitted from the light source 410 to the sub-pixel can be condensed, the light use efficiency can be improved. Note that a light source with high directivity is preferably used as the light source 410.
　上記の構成を有する液晶表示装置７００においても、光利用効率を向上して消費電力を低減することができる。また、上記の構成を有する液晶表示装置７００は、クロストークを低減して高品質の画像を表示できる。 Also in the liquid crystal display device 700 having the above-described configuration, it is possible to improve light utilization efficiency and reduce power consumption. In addition, the liquid crystal display device 700 having the above structure can display a high-quality image with reduced crosstalk.
　なお、上記の実施形態において組合せ可能な構成をそれぞれ組合せすることは当然に想定される。 Note that it is naturally assumed that the configurations that can be combined in the above embodiment are combined.
　今回開示された実施形態はすべての点で例示であって制限的なものではないと考えられるべきである。本発明の範囲は上記した説明ではなくて請求の範囲によって示され、請求の範囲と均等の意味および範囲内でのすべての変更が含まれることが意図される。 The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.
　１００，４００，５００，６００，７００　液晶表示装置、１１０，３１０，４１０　光源、１２０　第１基板、１３０　液晶層、１４０　第２基板、１５０　第１偏光板、１６０　第２偏光板、１７０，４７０　蛍光体層、１７０Ｂ　青色蛍光体、１７０Ｇ　緑色蛍光体、１７０Ｍ　遮光部、１７０Ｒ　赤色蛍光体、３００　光源ユニット、３２０　下側基板、３３０　光吸収体、３３１　開口部、３４０　上側基板、３７０　蛍光体、４７１　散乱体、５７０　カラーフィルタ、５７０Ｂ　青色フィルタ部、５７０Ｇ　緑色フィルタ部、５７０Ｍ　黒色フィルタ部、５７０Ｒ　赤色フィルタ部、６８０　遮蔽層、７９０，７９１　レンズ。 100, 400, 500, 600, 700 liquid crystal display device, 110, 310, 410 light source, 120 first substrate, 130 liquid crystal layer, 140 second substrate, 150 first polarizing plate, 160 second polarizing plate, 170, 470 fluorescence Body layer, 170B blue phosphor, 170G green phosphor, 170M light shielding part, 170R red phosphor, 300 light source unit, 320 lower substrate, 330 light absorber, 331 opening, 340 upper substrate, 370 phosphor, 471 scattering Body, 570 color filter, 570B blue filter part, 570G green filter part, 570M black filter part, 570R red filter part, 680 shielding layer, 790, 791 lens.

Claims (8)

  1. 　液晶層(１３０)と、
    　前記液晶層(１３０)を挟んで互いに対向する第１基板(１２０)および第２基板(１４０)と、
    　前記第１基板(１２０)の前記液晶層(１３０)と面する側とは反対側に位置する光源(１１０，４１０)と、
    　前記第２基板(１４０)の前記液晶層(１３０)と面する側とは反対側に位置し、前記光源(１１０，４１０)から照射される光を吸収してそれぞれ異なる色の光を発する複数種の画素蛍光体を含み、単位ピクセル毎に所定の色の光を発する蛍光体層(１７０，４７０)と、
    　前記光源(１１０，４１０)と前記液晶層(１３０)との間に位置する第１偏光板(１５０)と、
    　前記蛍光体層(１７０，４７０)と前記液晶層(１３０)との間に位置する第２偏光板(１６０)と
    を備え、
    　前記蛍光体層(１７０，４７０)は、前記画素蛍光体のそれぞれの周囲を囲んで格子状に位置する遮光部(１７０Ｍ)を含み、
    　前記画素蛍光体の各々は、平面視において、短辺と該短辺の３倍の長さを有する長辺とからなる矩形状の外形を有し、
    　前記蛍光体層(１７０，４７０)と前記液晶層(１３０)との間の距離が前記画素蛍光体の前記短辺の長さの２倍以下である、液晶表示装置。     A liquid crystal layer (130);
    A first substrate (120) and a second substrate (140) facing each other across the liquid crystal layer (130);
    A light source (110, 410) located on the opposite side of the first substrate (120) from the side facing the liquid crystal layer (130);
    A plurality of second substrates (140) that are located on the opposite side of the second substrate (140) facing the liquid crystal layer (130) and that absorb light emitted from the light sources (110, 410) and emit light of different colors. A phosphor layer (170, 470) that includes a seed pixel phosphor and emits light of a predetermined color for each unit pixel;
    A first polarizing plate (150) positioned between the light source (110, 410) and the liquid crystal layer (130);
    A second polarizing plate (160) positioned between the phosphor layer (170, 470) and the liquid crystal layer (130),
    The phosphor layer (170, 470) includes a light shielding part (170M) positioned in a grid surrounding each pixel phosphor.
    Each of the pixel phosphors has a rectangular outer shape composed of a short side and a long side having a length three times the short side in plan view,
    The liquid crystal display device, wherein a distance between the phosphor layer (170, 470) and the liquid crystal layer (130) is not more than twice the length of the short side of the pixel phosphor.
  2. 　前記光源(１１０)が、３８０ｎｍ以上４２０ｎｍ以下の範囲にピーク波長を有する可視光を照射する、請求項１に記載の液晶表示装置。 The liquid crystal display device according to claim 1, wherein the light source (110) emits visible light having a peak wavelength in a range of 380 nm to 420 nm.
  3. 　前記複数種の画素蛍光体は、前記単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する、前記可視光を吸収して赤色の光を発する赤色蛍光体(１７０Ｒ)と緑色の光を発する緑色蛍光体(１７０Ｇ)と青色の光を発する青色蛍光体(１７０Ｂ)とを含む、請求項２に記載の液晶表示装置。 The plurality of types of pixel phosphors include a red phosphor (170R) that absorbs visible light and emits red light, and green phosphor that emits green light, which respectively constitute a plurality of subpixels included in the unit pixel. The liquid crystal display device according to claim 2, comprising a body (170G) and a blue phosphor (170B) that emits blue light.
  4. 　前記光源(４１０)が、青色の光を照射する、請求項１に記載の液晶表示装置。 The liquid crystal display device according to claim 1, wherein the light source (410) emits blue light.
  5. 　前記複数種の画素蛍光体は、前記単位ピクセルに含まれる複数のサブピクセルをそれぞれ構成する、前記青色の光を吸収して赤色の光を発する赤色蛍光体(１７０Ｒ)と緑色の光を発する緑色蛍光体(１７０Ｇ)とを含み、
    　前記蛍光体層(４７０)は、前記単位ピクセルに含まれるサブピクセルを構成する、前記青色の光を散乱させる散乱体(４７１)を含む、請求項４に記載の液晶表示装置。     The plurality of types of pixel phosphors include a red phosphor (170R) that absorbs blue light and emits red light, and constitutes a plurality of subpixels included in the unit pixel, and green that emits green light. Phosphor (170G),
    The liquid crystal display device according to claim 4, wherein the phosphor layer (470) includes a scatterer (471) that scatters the blue light and constitutes a sub-pixel included in the unit pixel.
  6. 　前記蛍光体層(４７０)の前記液晶層(１３０)と面する側とは反対側に位置し、前記サブピクセルから発する色として所望される色が配色されたカラーフィルタ(５７０)をさらに備える、請求項３または５に記載の液晶表示装置。 A color filter (570) located on the opposite side of the phosphor layer (470) from the side facing the liquid crystal layer (130) and arranged with a desired color as a color emitted from the subpixel; The liquid crystal display device according to claim 3 or 5.
  7. 　前記蛍光体層(４７０)の前記液晶層(１３０)と面する側とは反対側において赤色の光および緑色の光を発する前記サブピクセルの位置に、赤色の光および緑色の光は透過させて青色の光は遮蔽する遮蔽層(６８０)をさらに備える、請求項５に記載の液晶表示装置。 Red light and green light are transmitted through the position of the sub-pixel that emits red light and green light on the side opposite to the side facing the liquid crystal layer (130) of the phosphor layer (470). The liquid crystal display device according to claim 5, further comprising a shielding layer (680) that shields blue light.
  8. 　前記第１基板(１２０)と前記光源(４１０)との間に位置し、前記光源(４１０)から照射された光を前記サブピクセルに集光させるレンズ(７９０，７９１)をさらに備える、請求項１から７のいずれかに記載の液晶表示装置。 The lens further comprising a lens (790, 791) positioned between the first substrate (120) and the light source (410), and condensing the light emitted from the light source (410) on the sub-pixel. The liquid crystal display device according to any one of 1 to 7.
PCT/JP2012/060684 2011-04-27 2012-04-20 Liquid crystal display device WO2012147641A1 (en)

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JP2007042314A (en) * 2005-08-01 2007-02-15 Konica Minolta Holdings Inc Organic electroluminescent element, display device, and lighting device
JP2007079565A (en) * 2005-09-10 2007-03-29 Samsung Electronics Co Ltd Liquid crystal display
JP2010197791A (en) * 2009-02-26 2010-09-09 Sony Corp Color liquid crystal display assembly and photo-conversion device
JP2010250259A (en) * 2009-03-27 2010-11-04 Epson Imaging Devices Corp Liquid crystal display device

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Publication number Priority date Publication date Assignee Title
JP2003255320A (en) * 2002-02-28 2003-09-10 Hitachi Ltd Liquid crystal display
JP2007042314A (en) * 2005-08-01 2007-02-15 Konica Minolta Holdings Inc Organic electroluminescent element, display device, and lighting device
JP2007079565A (en) * 2005-09-10 2007-03-29 Samsung Electronics Co Ltd Liquid crystal display
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