WO2009101746A1 - バックライトユニット及び液晶表示装置 - Google Patents
バックライトユニット及び液晶表示装置 Download PDFInfo
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- WO2009101746A1 WO2009101746A1 PCT/JP2008/072698 JP2008072698W WO2009101746A1 WO 2009101746 A1 WO2009101746 A1 WO 2009101746A1 JP 2008072698 W JP2008072698 W JP 2008072698W WO 2009101746 A1 WO2009101746 A1 WO 2009101746A1
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- liquid crystal
- crystal display
- light
- backlight unit
- display element
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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
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
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- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0053—Prismatic sheet or layer; Brightness enhancement element, sheet or layer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/005—Means for improving the coupling-out of light from the light guide provided by one optical element, or plurality thereof, placed on the light output side of the light guide
- G02B6/0051—Diffusing sheet or layer
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
- G02B6/0001—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems
- G02B6/0011—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings specially adapted for lighting devices or systems the light guides being planar or of plate-like form
- G02B6/0033—Means for improving the coupling-out of light from the light guide
- G02B6/0056—Means for improving the coupling-out of light from the light guide for producing polarisation effects, e.g. by a surface with polarizing properties or by an additional polarizing elements
-
- 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
- G02F1/133602—Direct backlight
- G02F1/133606—Direct backlight including a specially adapted diffusing, scattering or light controlling members
- G02F1/133607—Direct backlight including a specially adapted diffusing, scattering or light controlling members the light controlling member including light directing or refracting elements, e.g. prisms or lenses
Definitions
- the present invention relates to a backlight unit and a liquid crystal display device, and more particularly to a backlight unit and a liquid crystal display device that enable display with high contrast.
- the liquid crystal display device generally includes a liquid crystal display element and a backlight unit as main components.
- the liquid crystal display element has a structure in which a liquid crystal layer is sandwiched between transparent substrates, and each transparent substrate is provided with a polarizing plate.
- the backlight unit irradiates a liquid crystal display panel included in the liquid crystal display element from the back surface, and includes a light source, a light guide plate, a diffusion plate, and the like.
- liquid crystal display devices are required to have higher brightness, higher contrast, and the like.
- Various techniques have been proposed for such a demand.
- Patent Document 1 First, the technique described in Patent Document 1 will be described.
- the liquid crystal display element (liquid crystal display device) described in Patent Document 1 uses BEF (trade name, Brightness Enhancement Film), which is a brightness enhancement film manufactured by Sumitomo 3M Co., for the purpose of improving brightness and the like. It has been.
- the polarizing film (polarizing plate) on the backlight unit side is provided with light diffusing means.
- FIG. 16 is a cross-sectional view showing a configuration of a conventional liquid crystal display device. That is, the liquid crystal display device 130 described in Patent Document 1 has a configuration in which a TN (Twisted Nematic) liquid crystal layer 106 is sandwiched between substrates (transparent substrates) 102a and 102b, and further, polarizing films 101a and 101b are provided. ing. A backlight unit 108 is disposed on the back surface. In addition, the backlight unit 108 includes a reflection plate 113, a lower diffusive sheet 112, a light guide plate 111, and a BEF 110 as main components.
- TN Transmission Nematic liquid crystal layer
- FIG. 16 is a cross-sectional view showing a configuration of a conventional liquid crystal display device. That is, the liquid crystal display device 130 described in Patent Document 1 has a configuration in which a TN (Twisted Nematic) liquid crystal layer 106 is sandwiched between substrates (transparent substrates) 102a and 102b, and further
- a scattering material mixed film 109 is provided between the substrate 102b on the backlight unit 108 side and the polarizing film 101b.
- Patent Document 2 Next, the technique described in Patent Document 2 will be described.
- liquid crystal display device in a liquid crystal element (liquid crystal display element) in which a twisted nematic liquid crystal (liquid crystal layer) is sandwiched, a scattering layer provided between a polarizing plate and a light guide plate is provided. It has the characteristic that the polarization state is substantially maintained.
- FIG. 17 is a cross-sectional perspective view showing the configuration of the liquid crystal display device described in Patent Document 3. As shown in FIG.
- a liquid crystal display device 230 described in Patent Document 3 includes a liquid crystal display element 201 and a backlight (backlight unit) 204, and two lens films 202 and 203 are provided therebetween. It has been.
- the lens films 202 and 203 are overlapped so that the prism arrangement directions 206 and 207 are orthogonal to each other, and the prism arrangement direction 206 of the lens film 202 on the liquid crystal display element 201 side is the liquid crystal display element 201. Is parallel to the transmission axis 205 of the polarizing plate on the incident light side.
- FIG. 18 is a cross-sectional perspective view showing the configuration of the liquid crystal display device described in Patent Document 4. As shown in FIG.
- a liquid crystal display device 330 described in Patent Document 4 includes a liquid crystal panel 304 sandwiched between an incident polarizing plate (polarizing plate) 305 and an outgoing polarizing plate (polarizing plate) 306, and behind the liquid crystal panel 304.
- a backlight light source (light source) 301 is provided, and a prism sheet 308 is provided between the incident polarizing plate 305 and the backlight light source 301.
- the ridge line direction A0 of the prism sheet 308 and the transmission axis direction B0 of the incident polarizing plate 305 are orthogonal to each other, and this configuration achieves high brightness.
- Patent Document 5 Next, the technique described in Patent Document 5 will be described.
- a polarization separation surface that can selectively reflect and transmit a polarization component is provided on the light exit surface side of the surface light guide (light guide plate) in the backlight unit. It has been.
- the conventional liquid crystal display device has a problem that the contrast is not sufficient.
- liquid crystal display device using a liquid crystal display element capable of displaying at a high contrast, such as an MVA mode liquid crystal display element, the high contrast characteristics of the liquid crystal display element are sufficiently exhibited. It was difficult. This will be described below.
- FIG. 15 is a cross-sectional view schematically illustrating a configuration example of the liquid crystal display device 10.
- the liquid crystal display device 10 includes a liquid crystal display element 20 and a backlight unit 60 provided behind the liquid crystal display element 20.
- the liquid crystal display element 20 has a structure in which a liquid crystal layer 22 is sandwiched between a first substrate 24 and a second substrate 26.
- the first substrate 24 includes a first retardation plate 30 and a first retardation plate 30.
- the polarizing plate 34 is provided in order, and the second substrate 26 is similarly provided with the second retardation plate 32 and the second polarizing plate 36 in order.
- a brightness enhancement film 40 is provided between the first polarizing plate 34 and the backlight unit 60.
- the backlight unit 60 includes a light source (not shown), a light guide plate (not shown), two prism sheets (first prism sheet 66 and second prism sheet 68), and an upper diffusive sheet. 70 is provided.
- the liquid crystal layer 22 when the liquid crystal layer 22 is off, the light L1 is blocked by the liquid crystal display element 20 and is not emitted outside the liquid crystal display device 10.
- the ratio (on light quantity / off light quantity) between the light quantity of the emitted light when the liquid crystal layer 22 is on (on light quantity) and the light quantity of the emitted light when the liquid crystal layer 22 is off (off light quantity) is contrast. Value.
- the light L1 incident on the liquid crystal display element 20 from the normal direction can realize a high ON light amount and a low OFF light amount according to the ON / OFF of the liquid crystal layer 22.
- the liquid crystal display element 20 is a liquid crystal display element 20 capable of displaying with high contrast, such as the MVA mode liquid crystal display element 20, for example, in the light L1 from the normal direction, for example, the number of contrast values Thousands can be realized.
- the light L1 incident on the liquid crystal display element 20 from the normal direction can easily realize a low off light quantity.
- the light L1 incident on the liquid crystal display element 20 from the normal direction is the polarizing plates (the first polarizing plate 34 and the second polarizing plate 36) and the retardation plates (the first retardation plate 30 and the first retardation plate 30). This is because the light L1 changes and travels as originally designed because it enters the second phase difference plate 32) and the liquid crystal layer 22 perpendicularly.
- tilt light On the other hand, for example, light (tilted light) L2 that is emitted from the backlight unit 60 in an oblique direction and is incident on the liquid crystal display element 20 from an oblique direction is different from the light L1 and has a lower contrast value. It may be a factor. This will be described below.
- the tilted light L2 normally does not enter the eyes of the viewer V with respect to the viewer V who views the liquid crystal display device 10 from the normal direction.
- the contrast value does not decrease due to the inclined light L2.
- the traveling direction of the inclined light L2 may change. Specifically, the optical path of the light L2 may be bent in the liquid crystal display element 20 and travel in the direction of the viewer V (see arrow L3 in FIG. 15).
- the light bends in the liquid crystal display element 20 for example, scattering in the liquid crystal layer 22 or in a color filter (not shown) or TFT substrate (not shown). Scattering.
- the light incident on the liquid crystal display element 20 from an oblique direction and crossing the liquid crystal display element 20 in the oblique direction has a certain level of brightness (light quantity) even when the liquid crystal layer 22 is off. Then, the light may be emitted from the liquid crystal display element 20. This light causes light leakage when the liquid crystal layer 22 is off.
- the retardation plates (first retardation plate 30 and second retardation plate 32), polarizing plates (first polarizing plate 34 and second polarizing plate 36), liquid crystal layer 22 and the like in the liquid crystal display element 20 are as follows.
- the ON light amount and the OFF light amount are optimized, that is, the ON light amount is large and the OFF light amount is small.
- the liquid crystal display element 20 is optically designed so that the light incident on the liquid crystal display element 20 from the normal direction is blocked to the maximum.
- the tilted light is not sufficiently blocked even when the liquid crystal layer 22 is in an off state, and as a result, the tilted light is emitted from the liquid crystal display element 20 to the outside as light leakage.
- Such light leakage is particularly a problem in the liquid crystal display device provided with the liquid crystal display element capable of displaying with high contrast.
- an object of the present invention is to provide a backlight unit and a liquid crystal display device that enable display with higher contrast while maintaining the function as a surface light source. Is to provide.
- an object of the present invention is to provide a backlight unit and a liquid crystal display device capable of suppressing the intensity of the tilted light that enters the liquid crystal display element and causes a decrease in contrast.
- the backlight unit of the present invention A backlight unit comprising a light guide plate and a diffusive sheet, and light emitted from an emission surface illuminates a liquid crystal display element,
- the half-value width of the light emitted from the emission surface is 44 degrees or less.
- the backlight unit of the present invention is The half width is preferably 20 degrees or more and 40 degrees or less.
- the half width of the backlight unit is 44 degrees or less, preferably 20 degrees or more and 40 degrees or less, it is possible to display with higher contrast while maintaining the function as a surface light source.
- a backlight unit that can be realized can be realized. This will be described below.
- a liquid crystal display element irradiated with light from a backlight unit generally has a maximum contrast when light enters from the normal direction of the back surface of the liquid crystal display element and the light exits in the normal direction of the front surface.
- an optical member such as a polarizing plate or a retardation plate provided in the liquid crystal display element, an optical characteristic of the liquid crystal layer, and the like are designed to increase the contrast in such a case.
- the backlight unit As surface light source
- the backlight unit is desired to emit light with uniform in-plane on the exit surface.
- the backlight unit is required to have a function as a surface light source.
- the backlight unit is generally provided with a diffusive sheet for diffusing light.
- the light emitted from the emission surface of the backlight unit is normally directed in various directions by being diffused by the diffusive sheet.
- the light emitted from the backlight unit and incident on the liquid crystal display element includes not only light incident from the normal direction but also inclined light that is incident from a direction inclined from the normal direction. Become.
- the diffusive sheet is a general term for sheets having a function of diffusing light rays.
- the backlight unit configured as described above has a scattering property for the emitted light to function as a surface light source because the half-value width indicating the diffusion (scattering) characteristic of the emitted light is set to an appropriate value.
- strength of the inclined light which causes the fall of the said contrast value is suppressed.
- the above configuration can maintain the function as a surface light source, and can suppress the amount of light of the inclined light, more specifically, a backlight unit that enables display with higher contrast. There is an effect that a backlight unit can be provided.
- the backlight unit having the above-described configuration, since the diffusion characteristics of the emitted light are appropriately set, it is possible to suppress the occurrence of moiré caused by the interaction with the pixels of the liquid crystal display element.
- the backlight unit of the present invention is The haze value of the diffusive sheet is preferably 80% or less.
- the haze value of the diffusible sheet is 50% or more and 80% or less, it is easy to form a backlight unit in which the half-value width of the light emitted from the emission surface is 28 degrees or more and 44 degrees or less. can do.
- the backlight unit of the present invention is The haze value of the diffusive sheet is preferably 30% or more and 76% or less.
- the haze value of the diffusive sheet is 80% or less, it is possible to easily form a backlight unit in which the half-value width of the light emitted from the emission surface is 20 degrees or more and 40 degrees or less. it can.
- the backlight unit of the present invention is It is preferable that a prism sheet is provided between the light guide plate and the diffusive sheet.
- the prism sheet is provided, it is possible to realize brighter emission in a desired direction, for example, the normal direction of the backlight unit.
- the prism sheet means an optical sheet in which grooves in a certain direction are formed on the surface in order to control the traveling direction of light transmitted through the prism sheet.
- the liquid crystal display device of the present invention is It is preferable that the backlight unit is provided on the back surface of the liquid crystal display element.
- the liquid crystal display device of the present invention is It is preferable that a brightness enhancement film is provided between the liquid crystal display element and the backlight unit.
- the contrast is likely to be lowered.
- the half width of the backlight unit is appropriately set, high contrast display is possible.
- the polarized light reaching the brightness enhancing film is divided into a p wave and an s wave
- only one of the polarized lights, for example, only the p wave is transmitted, and the remaining s wave is reflected.
- it means a film having an effect of increasing incident light on an adjacent polarizing plate.
- the liquid crystal display device of the present invention is The liquid crystal display element is a vertical alignment type,
- the liquid crystal layer included in the liquid crystal display element is preferably divided into a plurality of different alignment regions in plan view.
- the liquid crystal display element is configured as a so-called MVA mode.
- the MVA mode liquid crystal display element can generally display with high contrast.
- the liquid crystal display device of the present invention is The liquid crystal display element is a vertical alignment type, The liquid crystal molecules of the liquid crystal layer included in the liquid crystal display element are aligned in all directions in plan view, Circular polarizers are provided on both sides of the liquid crystal layer.
- the liquid crystal display device of the present invention is
- the liquid crystal display element may be a twisted nematic type.
- the liquid crystal display element is configured as a vertical polarization mode circular polarization type or a so-called TN mode.
- the tilted light incident on the liquid crystal display element is emitted in the normal direction of the liquid crystal display element, thereby reducing the contrast. Arise.
- the reduction in contrast of the liquid crystal display element can be suppressed by combining the backlight unit in which the half width is appropriately set.
- the backlight unit of the present invention is characterized in that the half-value width of the light emitted from the emission surface is 44 degrees or less.
- a backlight unit that enables display with higher contrast while maintaining the function as a surface light source, more specifically, the inclined light that enters the liquid crystal display element and causes a decrease in contrast.
- the backlight unit and the liquid crystal display device capable of suppressing the strength can be provided.
- FIG. 1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
- FIG. 1 is a cross-sectional view of a liquid crystal display device according to an embodiment of the present invention.
- FIG. 1 showing an embodiment of the present invention, is a perspective view showing a cross section of a backlight unit. It is a figure which shows the measuring system of an optical characteristic. It is a figure which shows the relationship between a polar angle and transmitted light intensity. It is a figure which shows the relationship between an incident angle and transmitted light intensity.
- the other embodiment of this invention is shown and it is sectional drawing of a liquid crystal display device. It is a figure which shows the luminance distribution of the emitted light from a backlight unit. It is a figure which shows the luminance distribution of the emitted light from a backlight unit.
- the liquid crystal display device of the present invention has substantially the same configuration as the liquid crystal display device 10 described above with reference to FIG. The following description is based on FIG. 1, which is a cross-sectional view showing a schematic configuration of the liquid crystal display device of the present embodiment.
- the liquid crystal display device 10 mainly includes a liquid crystal display element 20 and a backlight unit 60. Then, light is emitted from the emission surface 80 of the backlight unit 60 and is incident on the liquid crystal display element 20, whereby display is performed.
- the liquid crystal display element 20 First, the liquid crystal display element 20 will be described.
- the liquid crystal display element 20 of the present embodiment is configured as a so-called MVA mode.
- liquid crystal layer 22 sandwiched between two opposing substrates is sandwiched between the first polarizing plate 34 and the second polarizing plate 36, and the liquid crystal molecules contained in the liquid crystal layer 22 are:
- a divided orientation such as a quadrant orientation is used.
- the backlight unit 60 of the present embodiment includes a light source (not shown), a light guide plate 64, two diffusible sheets (an upper diffusive sheet 70 and a lower diffusible sheet 72) as shown in FIG. ) And two prism sheets (a first prism sheet 66 and a second prism sheet 68).
- the members are stacked in the order of the light guide plate 64, the lower diffusive sheet 72, the first prism sheet 66, the second prism sheet 68, and the upper diffusive sheet 70.
- the first prism sheet 66 and the second prism sheet 68 have linear grooves each having triangular peaks and valleys on the surfaces thereof. Is formed.
- the groove directions of the first prism sheet 66 and the second prism sheet 68 are orthogonal to each other.
- FIG. 2 is a perspective sectional view showing the configuration of the backlight unit 60 in the present embodiment.
- the upper diffusive sheet 70 in the present embodiment is characterized in that the half width of the emitted light is 31 degrees in the backlight unit 60 when the diffusive sheet is used. This will be described below.
- FIG. 3A is a diagram showing a measurement system for measuring the intensity of emitted light from a measurement sample such as the backlight unit 60.
- the light emitted from the measurement sample is decomposed into 1 degree increments for both the azimuth angle and the polar angle, and the intensity at all angles is measured simultaneously. can do.
- the data of a specific direction is extracted numerically from the measurement result, and a two-dimensional graph of “polar angle” vs. “brightness or contrast” is created.
- the half value width which is an inclination
- a measuring device for performing the above-mentioned measurement although it does not specifically limit, For example, it can measure using EZcont88 (brand name) by ELDIM.
- the measurement of the half width of the backlight unit 60 is performed by using the measurement sample as the backlight unit 60.
- a diffusive sheet is used as the upper diffusive sheet 70 so that the half-value width of the emitted light from the backlight unit 60 is 31 degrees. This will be specifically described below.
- the half width is measured using the backlight unit 60 whose schematic configuration is shown in FIG. 2 as the measurement sample.
- the light receiving intensity is measured in a state where the light guide plate 64, the lower diffusive sheet 72, the first prism sheet 66, the second prism sheet 68, and the upper diffusive sheet 70 are stacked in this order. It is.
- the azimuth angle ( ⁇ ) 0 degrees is defined as shown in FIG.
- the groove directions of the first prism sheet 66 and the second prism sheet 68 are 45 degrees and 135 degrees.
- the half-value width of the backlight unit 60 was measured under the above conditions, the half-value width (0 to 360 degrees) was 31 degrees.
- a diffusive sheet having a haze value of 74.5% was used.
- the liquid crystal display device 10 With the above configuration, the liquid crystal display device 10 according to the present embodiment enables high-quality display and high-contrast display. This will be described below.
- the backlight unit 60 is preferably a uniform surface light source.
- the liquid crystal display device 10 is required to display with high contrast in addition to the uniform brightness display in the plane.
- the liquid crystal display element 20 is designed so as to be able to display with high contrast, the tilted light tends to be a factor of reducing contrast.
- the light emitted from the backlight unit 60 passes through the two polarizing plates and the liquid crystal layer and reaches the viewer V.
- the liquid crystal display panel means the liquid crystal display element 20 in which two polarizing plates (first polarizing plate and second polarizing plate) are removed. Specifically, it means that the liquid crystal layer 22 is sandwiched between two substrates in which color filters, switching elements, and the like are formed.
- FIG. 4 is a diagram showing the transmitted light intensity in the normal direction with respect to the display surface of the measurement sample with respect to the tilted light for two types (first and second) of measurement samples.
- the first measurement sample is one in which one polarizing plate is provided on each side of the glass substrate and the absorption axes of the polarizing plates are orthogonal to each other (“Glass +
- the second measurement sample is a liquid crystal display element (a liquid crystal display panel having a polarizing plate bonded thereto ("panel + polarizing plate" in FIG. 4), and the liquid crystal display panel is black. Display state).
- FIG. 4 shows the relationship between the incident light angle (polar angle ( ⁇ )) and transmitted light intensity for the two measurement samples.
- an A-PCF Polyization Conversion Film
- Nitto Denko Corporation is provided as a brightness enhancement film on the outer side of the back polarizing plate.
- FIG. 3B is a diagram showing a measurement system for measuring optical characteristics with respect to transmitted light.
- the inclination angle from the normal direction is the polar angle ( ⁇ ), and as shown in FIG.
- the rotation angle leftward from the horizontal direction on the plane is defined as an azimuth angle ( ⁇ ).
- the incident direction of the incident light can be tilted in the polar angle ( ⁇ ) direction as shown in FIG. 3B, and in the tilted state, the azimuth angle ( It can be rotated in the direction of ⁇ ).
- a measuring instrument for performing the above-described measurement is not particularly limited, but for example, measurement can be performed using an LCD 5200 (trade name) manufactured by Otsuka Electronics.
- the reduction rate is larger for “glass + polarizing plate”.
- the tilted light changes in the traveling direction of the light inside the liquid crystal display panel and is emitted in the normal direction, thereby causing a decrease in contrast.
- FIG. 5 is a diagram in which the measurement is performed in the same manner in increments of 5 degrees from 0 degrees to 360 degrees using the measurement system shown in FIG. 3B, and the results are displayed in polar coordinates.
- FIG. 5 is a diagram showing the transmitted light intensity when the polar angle ( ⁇ ) and the azimuth angle ( ⁇ ) of incident light are changed for a measurement sample similar to the “panel + polarizing plate”.
- the measurement sample used for the measurement shown in FIG. 5 is one in which a polarizing plate is bonded to both surfaces (front and back surfaces) of a liquid crystal display panel in a crossed Nicol arrangement, and a back polarizing plate (incident upon measurement)
- inclined light tends to be emitted in the normal direction at azimuth angles ( ⁇ ) of 45 degrees, 135 degrees, 225 degrees, and 315 degrees.
- the inclined light may change its traveling direction and be emitted in the normal direction, that is, in the direction of the viewer V of the liquid crystal display device 10. Further, as described above, the inclined light tends to exhibit a different behavior compared to the light incident from the normal direction due to the difference in the optical path length when passing through the liquid crystal display element 20. Specifically, for example, even when the liquid crystal layer 22 is in an off state (the liquid crystal layer 22 is in an off state is a state where the liquid crystal display element displays black, that is, a state where the transmittance is lowest), May not be sufficiently blocked.
- the liquid crystal display element displays black
- the inclined light is emitted in the normal direction as light leakage and enters the eyes of the viewer V.
- the half width is 31 degrees. That is, the degree of scattering of light emitted from the backlight unit 60 is appropriately controlled.
- the intensity of the inclined light can be appropriately suppressed.
- the pitch of the pixels of the liquid crystal display element 20 more specifically, the occurrence of “moire” caused by the interaction between the black matrix defining the pixels and the diffusive sheet or prism sheet of the backlight unit is also suppressed. I was able to.
- the liquid crystal display device 10 of the present embodiment includes a brightness enhancement film 40 in addition to the configuration of the liquid crystal display device 10 of the first embodiment.
- the liquid crystal display device 10 of the present embodiment has two polarizing plates (first polarizing plate 34 and Among the second polarizing plates 36), between the first polarizing plate 34, which is the polarizing plate closer to the backlight unit 60, and the backlight unit 60, manufactured by Nitto Denko Corporation as the brightness enhancement film 40 A-PCF (Polarization Conversion Film, product name).
- first polarizing plate 34 which is the polarizing plate closer to the backlight unit 60
- the backlight unit 60 manufactured by Nitto Denko Corporation as the brightness enhancement film 40 A-PCF (Polarization Conversion Film, product name).
- the brightness enhancement film 40 means a film having an action of increasing incident light to an adjacent polarizing plate by the following mechanism, for example.
- the polarized light reaching the brightness enhancement film 40 is divided into a p wave and an s wave
- only one of the polarized waves for example, only the p wave is transmitted, and the remaining s wave is reflected.
- the reflected s-wave reaches the brightness enhancement film 40 again, a part of the s-wave is changed to a p-wave, and the p-wave is transmitted.
- Such an operation is repeated, for example, only the p wave is selectively transmitted.
- the brightness enhancement film 40 is not limited to the A-PCF (trade name), and, for example, D-BEF (trade name, Brightness Enhancement Film) manufactured by Sumitomo 3M Co., Ltd. may be used. You can also.
- this brightness enhancement film may be called a polarizing reflection film or a polarizing mirror film.
- FIG. 7A and 7B are diagrams showing the luminance distribution of the light emitted from the backlight unit 60.
- FIG. 7A and 7B are diagrams showing the luminance distribution of the light emitted from the backlight unit 60.
- FIG. 7A shows the backlight unit 60 shown in FIG. 1, that is, the light guide plate 64, the lower diffusive sheet 72, the first prism sheet 66, the second prism sheet 68, and the upper diffusion.
- a laminate of the conductive sheet 70 is used as a measurement sample.
- the previous figure has shown the azimuth (phi) and polar angle ((theta)) dependence regarding the emitted light from the measurement sample.
- FIG. 7B shows a measurement sample obtained by superimposing the A-PCF as the brightness enhancement film 40 on the measurement sample of FIG. Similar to FIG. 7A, the azimuth angle ( ⁇ ) and polar angle ( ⁇ ) dependence is shown.
- the light emitted from the backlight unit 60 in the normal direction is transmitted through the brightness enhancement film by providing the brightness enhancement film 40.
- the luminance is improved with respect to incident light in a wider inclination range.
- the light is emitted from a wide polar angle ( ⁇ ) range in almost all azimuth ( ⁇ ) ranges.
- the liquid crystal display element 20 has On the other hand, it can be seen that the incidence of inclined light increases.
- (a) of FIG. 8 is obtained by measuring the received light intensity in the normal direction using the liquid crystal display device 10 according to the first embodiment whose schematic structure is shown in FIG. 1 as a measurement sample.
- FIG. 8B shows the liquid crystal display device 10 of the present embodiment whose schematic structure is shown in FIG. 6 (A-PCF as the brightness enhancement film 40 is added to the liquid crystal display device 10 of the first embodiment). Added) was used as a measurement sample.
- FIGS. 8A and 8B show the dependence of the intensity of the emitted light with respect to the normal direction from the liquid crystal display device 10 on the azimuth angle ( ⁇ ) and polar angle ( ⁇ ) with respect to the tilt angle of the incident light. The difference by the presence or absence of the brightness enhancement film 40 is shown.
- FIG. 9 shows the difference in the light emitted from the liquid crystal display device 10 in the normal direction depending on the presence or absence of the brightness enhancement film 40 (brightness improvement under the same conditions from the intensity of the emitted light with the brightness enhancement film 40 present). It is the figure which deducted the emitted light intensity without the film 40).
- the azimuth angle ( ⁇ ) 45 degrees, 135 degrees, 225 degrees, and 315 degrees, and particularly, the polar angle ( ⁇ ) is incident from around 50 degrees. It can be seen that the light is more easily emitted in the normal direction.
- the contrast value is likely to be lowered.
- the measurement system and the measurement sample for obtaining the output intensity difference are the same as those described above. Further, this measurement is performed when the liquid crystal display device 10 performs black display.
- the half-value width of the light emitted from the backlight unit 60 is 31 degrees.
- a light unit 60 is used.
- the liquid crystal display device 10 is provided with the brightness enhancement film 40, it is possible to realize display with uniform brightness in the plane and display with high contrast.
- Examples and comparative examples Examples of the liquid crystal display device 10 having the configurations of the first embodiment and the second embodiment, that is, the liquid crystal display device 10 that is not provided with the brightness enhancement film and the liquid crystal display device 10 that is provided. Examples and comparative examples will be described, and the contents and characteristics of the implementation will be specifically described.
- FIG. 10 shows the luminance distribution and contrast of the backlight unit 60 alone and the A-PCF as the luminance enhancement film 40 provided on the emission side of the backlight unit 60 for each example and comparative example.
- FIG. 10 This will be specifically described below.
- the configurations of the backlight unit 60 and the liquid crystal display element 20 are the same, and the upper diffusive sheet 70 is different.
- Example 1 “D151SIII” (product name) manufactured by Tsujiden Co., Ltd. was used as the upper diffusive sheet 70.
- Example 2 “D120SII” in Example 2
- Comparative Example 1 “D114SIII” is used.
- the haze values of the above diffusive sheets were 55.0% for "D151SIII", 76.0% for "D120SII", 32.5% for "D117UESIII", and 81.4% for "D114SIII”. .
- the lower diffusive sheet 72 uses the same film, “D122S4” manufactured by Tsujiden, in Comparative Examples 1 and 2 and Examples 1 and 2.
- Optical characteristics such as half width of the backlight unit using the above materials as a diffusive sheet were measured.
- the measurement sample of “backlight unit alone” or “without backlight unit A-PCF” in FIG. 10 has the cross-sectional configuration shown in FIG.
- the measurement sample of “backlight unit + A-PCF” or “with backlight unit A-PCF” in FIG. 10 has the cross-sectional configuration shown in FIG.
- the difference between the configuration of the measurement sample shown in FIG. 11A and the configuration of the measurement sample shown in FIG. 11B is that the A-PCF as the brightness enhancement film 40 is provided. No.
- the half width was measured using the measurement sample shown in FIG. 11A, that is, the measurement sample having a configuration in which the brightness enhancement film 40 is not provided.
- the contrast and the normal direction of the backlight unit 60 are different depending on the presence or absence of the A-PCF as the brightness enhancement film 40 (FIGS. 11A and 11B).
- the dependence of the luminance on the incident angle was measured.
- the contrast tends to be reduced by providing the brightness enhancement film 40.
- FIG. 12 is a diagram showing the contrast value in the liquid crystal display device 10 for each example.
- Example 1 in which the half-value width is 31 degrees, a moiré does not occur, and a contrast value equivalent to or comparable to that of Comparative Example 1 that cannot actually be adopted because moiré occurs. could be realized.
- the overall contrast value is lower than in the configuration in which the brightness enhancement film 40 is not provided.
- Example 1 and Example 2 it was possible to realize a contrast value equivalent to or inferior to that of Comparative Example 1 that cannot be used because moire occurs. Further, in Comparative Example 2, the moire was not generated but the contrast value was low as in the case without the brightness enhancement film 40.
- liquid crystal mode In the above description, the liquid crystal mode has been described with respect to the MVA mode. However, the liquid crystal mode of the present invention is not limited thereto.
- liquid crystal molecules are omnidirectionally aligned, not divided, using rivets or the like, and between the liquid crystal layer and each polarizing plate, for example, ⁇ / 4 A so-called circular polarization type in which a retardation plate is inserted can also be used.
- the difference between the linearly polarized light type and the circularly polarized light type will be described later with reference to FIG.
- a TN (Twisted Nematic) mode for example, a TN (Twisted Nematic) mode, an IPS (In Plane Switching) mode, or the like can be used.
- IPS In Plane Switching
- FIG. 13 are diagrams showing light scattering characteristics in each liquid crystal mode. The details will be described below.
- FIG. 13A is a measurement sample in which a polarizing plate is provided in such a manner that the optical axes are orthogonal to each other on both surfaces of the glass plate (crossed Nicol arrangement), and FIG. 13B is a vertical alignment mode.
- FIG. 13C shows the measurement sample provided with the ISP mode liquid crystal display element
- FIG. 13D shows the TN mode.
- FIG. 13E shows a measurement sample provided with a liquid crystal display element.
- FIG. 13E shows the linearly polarized light type measurement sample in the vertical alignment mode liquid crystal display element described in the above embodiment.
- the intensity depends on the incident direction (azimuth angle ( ⁇ ) and polar angle ( ⁇ )).
- the characteristics shown in FIGS. 13B to 13E are obtained when each liquid crystal display element is in a black display state.
- the linearly polarized light type in the vertical alignment mode such as the MVA mode can more easily emit inclined light in the normal direction.
- the effect of suppressing the reduction in contrast according to the present invention is exhibited more greatly.
- FIG. 14 is a diagram showing the difference between the circularly polarized light type and the linearly polarized light type in the vertical alignment mode.
- the liquid crystal (liquid crystal molecules) in the liquid crystal layer is oriented in all directions around a protrusion such as a rivet.
- the liquid crystal layer is divided into a plurality of alignment regions R in plan view.
- the alignment region R means a region in which the alignment direction of the liquid crystal (molecule) is different from other adjacent portions.
- FIG. 14 shows an example of alignment divided into four.
- the layer configuration of the liquid crystal display element is also different. That is, in the linearly polarized light type, only the polarizing plates are provided on both surfaces of the liquid crystal layer (liquid crystal panel).
- the circular polarization type includes a retardation plate such as a ⁇ / 4 plate (circular polarizing plate).
- a retardation plate is provided on both sides of a liquid crystal layer (liquid crystal panel), and a polarizing plate is further provided on the outside of each.
- linearly polarized light type and the circularly polarized light type in the vertical alignment mode generally have higher contrast, and as a result, the backlight of the present invention is more effective.
- the prism sheet has a triangular groove shape, but the prism sheet groove shape is not limited to such a shape.
- the shape of the groove may be rounded semicircular peaks and valleys.
- the number of prism sheets is not limited to such a number, and may be, for example, zero or one.
- the diffusive sheet is provided with the upper diffusive sheet 70 and the lower diffusive sheet 72, but only one of the upper diffusive sheet 70 and the lower diffusible sheet 72 is provided. You can also.
- the same material is used for the upper diffusive sheet 70 and the lower diffusive sheet 72, but different materials may be used for the upper diffusible sheet 70 and the lower diffusible sheet 72.
- the backlight unit and the liquid crystal display device of the present invention enable display with high contrast
- the backlight unit and the liquid crystal display device can be suitably used for display applications that require high-quality display.
Abstract
Description
まず、特許文献1に記載された技術について説明する。
つぎに、特許文献2に記載された技術について説明する。
つぎに、特許文献3に記載された技術について、図17に基づいて説明する。図17は、特許文献3に記載された液晶表示装置の構成を示す断面斜視図である。
つぎに、特許文献4に記載された技術について図18に基づいて説明する。図18は、特許文献4に記載された液晶表示装置の構成を示す断面斜視図である。
つぎに、特許文献5に記載された技術について説明する。
図15は、液晶表示装置10の一構成例の概略を示す断面図である。
つぎに、前記液晶表示装置10における光の進行プロセスについて説明する。
ここで、高いコントラスト値を実現するためには、特に、液晶層22がオフの際のオフ光量を低下させることが重要である。
これに対し、例えば前記バックライトユニット60から斜め方向に出射し、前記液晶表示素子20に対して斜め方向から入射した光(傾斜光)L2は、前記光L1とは相違し、コントラスト値低下の要因となる場合がある。以下説明する。
しかしながら、前記傾斜光L2の進行方向が変化する場合がある。具体的には、前記光L2の光路が、前記液晶表示素子20内で折れ曲がり、前記観者Vの方向に進む場合がある(図15の矢印L3参照)。
これは、液晶表示素子20に対して、法線方向から入射する光L1と、前記傾斜光L2とでは、各光学板(位相差板や偏光板など)や液晶層22等を透過する際の光路長が相違し、そのため、所望の光学変化が得られないためである。すなわち、液晶表示素子20の光学特性に関する角度依存性が光漏れの原因となる。
導光板と拡散性シートとが備えられ、出射面から出射される光が液晶表示素子を照らすバックライトユニットであって、
前記出射面から出射される光の半値幅が44度以下であることを特徴とする。
前記半値幅が20度以上40度以下であることが好ましい。
まず、半値幅について説明する。バックライトユニットなど半値幅を測定する測定サンプルについて、その出射面から法線方向に出射した光に対して光の強度が半分になる傾斜角度を半値幅(度)とする。これは、出射される光の強度が、法線方向から傾斜するにつれ弱くなるとの特性に基づくものである。
バックライトユニットから光が照射される液晶表示素子は、一般に、液晶表示素子の裏面の法線方向から光が入射し、かかる光が表面の法線方向に出射する場合に、そのコントラストが最大となるように設計されている。具体的には、液晶表示素子に備えられる偏光板や位相差板などの光学部材、及び液晶層等の光学特性などが、かかる場合のコントラストが高くなるように設計されている。
他方、液晶表示素子の表示において、面内で均一な明るさを有する表示を実現するために、バックライトユニットには、その出射面において、面内均一な光を出射することが望まれている。言い換えると、バックライトユニットには、面光源としての機能が要求されている。
そして、先に説明した通り、液晶表示素子のコントラスト設計は、法線方向から入射した光を前提としているため、前記傾斜光が、例えば、前記液晶表示素子内部で屈折し、液晶表示素子の法線方向に出射した場合には、その出射光は所望の明るさ(白又は黒)を有しておらず、その結果、コントラストの低下を招きやすい。
前記拡散性シートのヘイズ値が、80%以下であることが好ましい。
前記拡散性シートのヘイズ値が、30%以上76%以下であることが好ましい。
前記導光板と前記拡散性シートとの間には、プリズムシートが設けられていることが好ましい。
液晶表示素子の裏面に、前記バックライトユニットが設けられていることが好ましい。
前記液晶表示素子と前記バックライトユニットとの間に、輝度向上フィルムが備えられていることが好ましい。
前記液晶表示素子が垂直配向型であり、
前記液晶表示素子に含まれる液晶層が、平面視において、複数の異なる配向領域に分割されていることが好ましい。
前記液晶表示素子が垂直配向型であり、
前記液晶表示素子に含まれる液晶層の液晶分子が、平面視において、全方位方向に配向しており、
前記液晶層の両面に、円偏光板が備えられている。
前記液晶表示素子をねじれネマチック型としてもよい。
20 液晶表示素子
22 液晶層
40 輝度向上フィルム
60 バックライトユニット
64 導光板
66 第1プリズムシート (プリズムシート)
68 第2プリズムシート (プリズムシート)
70 上拡散性シート (拡散性シート)
72 下拡散性シート
80 出射面
R 配向領域
本発明の一実施の形態について各図に基づいて説明すると以下の通りである。
本発明の液晶表示装置は、先に図15に基づいて説明した液晶表示装置10とほぼ同様の構成を有している。以下、本実施の形態の液晶表示装置の概略構成を示す断面図である図1に基づいて説明する。
まず、前記液晶表示素子20について説明する。本実施の形態の液晶表示素子20は、いわゆるMVAモードとして構成されている。
つぎに、本実施の形態におけるバックライトユニット60について説明する。本実施の形態のバックライトユニット60には、光源(図示せず)と、前記図1に示すように、導光板64、2枚の拡散性シート(上拡散性シート70と下拡散性シート72)、及び、2枚のプリズムシート(第1プリズムシート66と第2プリズムシート68)とが備えられている。そして、前記各部材は、導光板64、下拡散性シート72、第1プリズムシート66、第2プリズムシート68、上拡散性シート70の順に重ねられている。
つぎに、本実施の形態における拡散性シートについて説明する。
まず、上記半値幅を測定するための測定系の概略を図3の(a)に示す。図3の(a)は、バックライトユニット60等の測定サンプルからの出射光の強度等を測定するための測定系を示す図である。
ここで、本実施の形態においては、上述のように、上拡散性シート70に、バックライトユニット60からの出射光の半値幅が31度となるような拡散性シートが用いられている。以下、具体的に説明する。
上記の構成により、本実施の形態の液晶表示装置10では、高品位な表示とともに、高コントラストな表示が可能となる。以下、説明する。
まず、液晶表示装置10においては、その面内で均一な明るさの表示を実現するために、バックライトユニット60から面内において均一な明るさを有する光が出射されることが好ましい。すなわち、バックライトユニット60は、均一な面光源であることが好ましい。
つぎに、液晶表示装置10のコントラストについて説明する。
つぎに、傾斜光よるコントラストの低下について、より詳しく説明する。
ここで、図4などに結果を示した光の折れ曲がり特性を測定するための測定系について説明する。
図4に示すように、入射光を測定サンプルの法線方向から傾斜させていくと、2つの測定サンプル(「ガラス+偏光板」、「パネル+偏光板」)ともに透過光強度は減少する。
つぎに、傾斜光の法線方向への透過のしやすさについて、その方位角(φ)依存性を、図5に基づいて説明する。図5は、図3の(b)に示した測定系を用いて方位0度から360度まで5度刻みで同様に測定し、その結果を極座標表示した図である。図5は、前記「パネル+偏光板」と同様の測定サンプルについて、入射光の極角(θ)と方位角(φ)とを変化させた場合の、前記透過光強度を示す図である。
以上のように、液晶表示素子20においては、傾斜光がその進行方向を変化させ、法線方向、すなわち、液晶表示装置10の観者Vの方向に出射する場合がある。また、先に説明したとおり、傾斜光は、液晶表示素子20を透過する際の光路長の相違などから、法線方向から入射する光と比べ、異なる挙動を示しやすい。具体的には、例えば液晶層22がオフの状態(液晶層22がオフの状態とは、液晶表示素子が黒表示をしている場合すなわち透過率が最も低くなる状態)であっても、光が十分遮断されない場合がある。
本発明の他の実施の形態について各図に基づいて説明すれば、以下の通りである。なお、本実施の形態において説明すること以外の構成は、前記実施の形態1と同じである。
ここで、輝度向上フィルム40とは、例えばつぎに示す仕組みなどにより、隣接する偏光板に対する入射光を増加させる作用を有するフィルムのことを意味する。
ここでまず、バックライトユニット60からの出射光に関して、前記輝度向上フィルム40の有無よる輝度特性の差異について、図7の(a)及び(b)に基づいて説明する。
つぎに、液晶表示装置10からの法線方向への出射光について、入射光の方位角(φ)及び極角(θ)に対する依存性を、図8の(a)及び(b)に基づいて説明する。
この点、本実施の形態の液晶表示装置10においては、前記実施の形態1における液晶表示装置10と同様に、バックライトユニット60から出射される光の半値幅が31度となるような、バックライトユニット60が用いられている。
以下、前記実施の形態1及び実施の形態2の構成を有する液晶表示装置10について、すなわち、輝度向上フィルムが備えられていない液晶表示装置10と備えられている液晶表示装置10とについて、実施例と比較例とを示し、実施の内容及びその特性を具体的に説明する。
まず、半値幅について説明する。ここで半値幅は、前記図11の(a)に示す測定サンプル、すなわち輝度向上フィルム40が備えられていない構成の測定サンプルを用いて測定した。
また、前記各実施例及び比較例について、輝度向上フィルム40としてのA-PCFの有無(図11の(a)及び(b))別に、バックライトユニット60としてのコントラスト、及び、法線方向に対する輝度についての入射角度(方位角(φ)及び極角(θ))依存性を測定した。
また、コントラストに関しては、バックライトユニット60からの出射光の半値幅や上拡散性シート70のヘイズ値が大きくなるにつれて、その値が小さくなる傾向がある。
つぎに、前記各実施例及び比較例のバックライトユニット60単体、又は、バックライトユニット60に輝度向上フィルムが設けられたものに、液晶表示素子20を組み合わせた液晶表示装置10について、そのコントラストを測定した。
まず、輝度向上フィルム40としてのA-PCFが備えられていない構成について説明する。
つぎに、輝度向上フィルム40としてのA-PCFが備えられている構成について説明する。
また、前記の説明では、液晶モードについて、MVAモードについて説明したが、本発明の液晶モードは、かかるものに限定されない。例えば他の液晶モードとしては、垂直配向モードにおいても、リベット等を用いて、液晶分子を分割配向ではなく、全方位配向させ、液晶層と各偏光板との間に、例えばλ/4などの位相差板を挿入した、いわゆる円偏光タイプを用いることもできる。なお、前記直線偏光タイプと円偏光タイプとの相違については、図14に基づいて後述する。
また、前記の説明においては、プリズムシートの溝の形状が三角形状のものについて説明したが、プリズムシートの溝の形状は、かかる形状に限定されるものではない。他の例としては、溝の形状を丸みを帯びた半円形状の山と谷とにしてもよい。
Claims (10)
- 導光板と拡散性シートとが備えられ、出射面から出射される光が液晶表示素子を照らすバックライトユニットであって、
前記出射面から出射される光の半値幅が44度以下であることを特徴とするバックライトユニット。 - 前記半値幅が20度以上40度以下であることを特徴とする請求項1に記載のバックライトユニット。
- 前記拡散性シートのヘイズ値が、80%以下であることを特徴とする請求項1又は2に記載のバックライトユニット。
- 前記拡散性シートのヘイズ値が、30%以上76%以下であることを特徴とする請求項3に記載のバックライトユニット。
- 前記導光板と前記拡散性シートとの間には、プリズムシートが設けられていることを特徴とする請求項1から4のいずれか1項に記載のバックライトユニット。
- 液晶表示素子の裏面に、請求項1から5のいずれか1項に記載のバックライトユニットが設けられていることを特徴とする液晶表示装置。
- 前記液晶表示素子と前記バックライトユニットとの間に、輝度向上フィルムが備えられていることを特徴とする請求項6に記載の液晶表示装置。
- 前記液晶表示素子が垂直配向型であり、
前記液晶表示素子に含まれる液晶層が、平面視において、複数の異なる配向領域に分割されていることを特徴とする請求項6又は7に記載の液晶表示装置。 - 前記液晶表示素子が垂直配向型であり、
前記液晶表示素子に含まれる液晶層の液晶分子が、平面視において、全方位方向に配向しており、
前記液晶層の両面に、円偏光板が備えられていることを特徴とする請求項6又は7に記載の液晶表示装置。 - 前記液晶表示素子がねじれネマチック型であることを特徴とする請求項6又は7に記載の液晶表示装置。
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
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CN2008801268299A CN101952770A (zh) | 2008-02-15 | 2008-12-12 | 背光源单元和液晶显示装置 |
JP2009553345A JPWO2009101746A1 (ja) | 2008-02-15 | 2008-12-12 | バックライトユニット及び液晶表示装置 |
EP08872277A EP2249197A4 (en) | 2008-02-15 | 2008-12-12 | BACKLIGHT UNIT AND LIQUID CRYSTAL DISPLAY DEVICE |
US12/867,593 US20110102311A1 (en) | 2008-02-15 | 2008-12-12 | Backlight unit and liquid crystal display device |
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JP2008-035346 | 2008-02-15 | ||
JP2008035346 | 2008-02-15 |
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PCT/JP2008/072698 WO2009101746A1 (ja) | 2008-02-15 | 2008-12-12 | バックライトユニット及び液晶表示装置 |
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US (1) | US20110102311A1 (ja) |
EP (1) | EP2249197A4 (ja) |
JP (1) | JPWO2009101746A1 (ja) |
CN (1) | CN101952770A (ja) |
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Cited By (1)
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JP2011138710A (ja) * | 2009-12-28 | 2011-07-14 | Casio Computer Co Ltd | 光源装置及び表示装置 |
Families Citing this family (3)
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TWI588910B (zh) * | 2011-11-30 | 2017-06-21 | 半導體能源研究所股份有限公司 | 半導體裝置的製造方法 |
JP6509482B2 (ja) * | 2013-08-22 | 2019-05-08 | 東洋鋼鈑株式会社 | 偏光子保護フィルムの製造方法及び偏光子保護フィルム |
US10215368B2 (en) * | 2016-06-03 | 2019-02-26 | Applied Materials, Inc. | Energy efficient communication and display device |
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RU2010137791A (ru) | 2012-03-20 |
RU2454689C2 (ru) | 2012-06-27 |
EP2249197A1 (en) | 2010-11-10 |
EP2249197A4 (en) | 2011-10-26 |
US20110102311A1 (en) | 2011-05-05 |
CN101952770A (zh) | 2011-01-19 |
JPWO2009101746A1 (ja) | 2011-06-09 |
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