WO2006036032A1 - 光学シート、バックライトおよび液晶表示装置 - Google Patents
光学シート、バックライトおよび液晶表示装置 Download PDFInfo
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- WO2006036032A1 WO2006036032A1 PCT/JP2005/018588 JP2005018588W WO2006036032A1 WO 2006036032 A1 WO2006036032 A1 WO 2006036032A1 JP 2005018588 W JP2005018588 W JP 2005018588W WO 2006036032 A1 WO2006036032 A1 WO 2006036032A1
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- Prior art keywords
- optical sheet
- cylindrical lens
- sheet
- main surface
- light
- Prior art date
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Classifications
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0273—Diffusing elements; Afocal elements characterized by the use
- G02B5/0278—Diffusing elements; Afocal elements characterized by the use used in transmission
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B3/00—Simple or compound lenses
- G02B3/02—Simple or compound lenses with non-spherical faces
- G02B3/06—Simple or compound lenses with non-spherical faces with cylindrical or toric faces
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0268—Diffusing elements; Afocal elements characterized by the fabrication or manufacturing method
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/02—Diffusing elements; Afocal elements
- G02B5/0273—Diffusing elements; Afocal elements characterized by the use
- G02B5/0294—Diffusing elements; Afocal elements characterized by the use adapted to provide an additional optical effect, e.g. anti-reflection or filter
-
- 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
-
- 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
-
- 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
- G02F1/133504—Diffusing, scattering, diffracting elements
- G02F1/133507—Films for enhancing the luminance
-
- 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 an optical sheet that can enhance the directivity of light, a backlight including the optical sheet, and a liquid crystal display device.
- BACKGROUND ART In recent years, in a liquid crystal display device equipped with a liquid crystal panel, it has become an important issue to increase the commercial value of the liquid crystal display device to reduce power consumption and improve display luminance. Under such circumstances, it is strongly desired to improve the optical gain on the pack light side. Therefore, as a method for meeting this demand, it has been proposed that a liquid crystal display device is provided with a prism sheet having a prism array on the illumination light exit side (see, for example, Japanese Patent No. 3 1 4 7 2 0 5). )
- Fig. 1 shows the appearance of a conventional prism sheet.
- Figure 2 shows the XZ cross-sectional shape of a conventional prism sheet.
- incident light rays are reflected by the primary prism component T 1 that is directly transmitted through the prism slope, and then reflected again by the prism slope after being reflected by one prism slope, depending on the incident angle.
- the return light component R returned to the incident side can be divided into the second transmitted light component T 2 that is reflected by one prism slope and then transmitted through the other prism slope and emitted to the front surface of the prism sheet.
- the primary transmitted light component T 1 is effectively used including light emitted in the front direction. It is a light and bundle component.
- the return light component R is a luminous flux component that is effective for increasing the luminance of the light emitting surface by being incident on a diffusing sheet that is regarded as a light emitting surface (surface light source) and diffusely reflected.
- the second-order transmitted light component T 2 is a light flux component that is emitted to the wide-angle side outside the angle of view of the liquid crystal panel, and is a light flux component that does not contribute to improvement in luminance.
- the incident light is refracted and condensed to be condensed in the front direction, and the directivity is improved so as to increase the front luminance.
- the reflected light is diffused and scattered by a diffusion sheet that is regarded as a light emitting surface (surface light source), and as a result, the luminance of the light emitting surface is increased, thereby increasing the front luminance.
- incident light can be divided into a primary transmitted light component T 1, a secondary transmitted light component T 2, and a returning light component R according to the incident angle.
- a part of the light beam emitted from the off-axis virtual light source is totally reflected on one inclined surface of the prism sheet and re-enters the other inclined surface. And is reused as the return light component R. Alternatively, after multiple reflection, it is effectively used as the primary transmitted light component T 1 and the returned light component R to the light source side. .
- the light beam emitted from the off-axis virtual light source is totally reflected on one slope of the prism sheet, refracted and transmitted on the other slope, and is emitted to the wide-angle side outside the effective viewing angle of the liquid crystal panel.
- a secondary transmitted light component ⁇ 2 As described above, the second-order transmitted light component ⁇ 2 is a light flux component that is ineffective for improving luminance.
- the polarization directivity may be extremely deteriorated due to the directivity of incidence, which impairs the effective luminance improvement on the liquid crystal panel side. If the above-described prism sheet is provided between the diffusion sheet and the liquid crystal panel, bleeding will occur. For this reason, it is desired to suppress the occurrence of bleeding on the appearance.
- a first object of the present invention is to provide an optical sheet that achieves a high luminance distribution within a predetermined viewing angle, and that can improve the luminance by suppressing the generation of the second transmitted light component T 2. It is to provide a backlight and a liquid crystal display device.
- the second object of the present invention is to realize a high luminance distribution within a predetermined viewing angle, to suppress the generation of the second transmitted light component T 2 and to improve the luminance, and to provide a prism sheet.
- the secondary transmitted light is re-incident on the adjacent prism, enters the sheet again, is added to the return light, and is reused. is there.
- some are effectively used as the primary transmitted light or the return light to the light source after multiple reflection.
- Most of these secondary transmitted light is incident on the main surface of the prism sheet from an oblique direction and is totally reflected on one surface of the prism and then refracted and transmitted on the other surface. It is generated by doing. .
- the present inventor increases the primary transmitted light by refracting and transmitting the light incident on the vicinity of the apex of the prism from the direction perpendicular to the main surface of the prism sheet, and with respect to the main surface of the prism sheet.
- the present invention has been devised based on the above studies.
- the first invention is an optical sheet in which cylindrical 'lens bodies having higher-order aspheric surfaces are provided so as to be continuously arranged on one main surface.
- the optical sheet is characterized in that when the Z-axis is taken parallel to the normal direction of the optical sheet and the X-axis is taken in the direction of the cylindrical lens body, the sectional shape of the cylindrical lens satisfies the following formula: .
- R is the radius of curvature of the apex of the tip
- K is the conic constant
- A, B, C ⁇ are aspherical coefficients.
- the second invention comprises a light source that emits illumination light
- Cylindrical lens bodies with higher-order aspherical surfaces form a continuous row It is provided,
- the pack light is characterized in that when the z-axis is taken parallel to the normal direction of the optical sheet and the x-axis is taken in the direction of the cylindrical lens body, the sectional shape of the cylindrical lens satisfies the following formula: .
- A, B, C ... are aspheric coefficients.
- a third invention comprises a light source that emits illumination light
- An optical sheet that increases the directivity of the illumination light emitted from the backlight, and a liquid crystal panel that displays an image based on the illumination light emitted from the optical sheet;
- Cylindrical lens bodies having higher-order aspheric surfaces are provided so as to form a continuous row
- a liquid crystal display device characterized in that when the Z-axis is taken in parallel to the normal direction of the optical sheet and the X-axis is taken in the direction of the cylindrical lens body, the sectional shape of the cylindrical lens satisfies the following formula: is there.
- R is the radius of curvature of the apex of the tip
- K is the conic constant
- A, B, C ⁇ are aspherical coefficients.
- the radius of curvature R, the conic constant K, and the aspheric coefficients A, B, C ⁇ ′ satisfy the following numerical ranges.
- the other main surface opposite to the one main surface on which the cylindrical lens body is provided has a height of 0.20 m or more from the average center plane.
- a protrusion is further provided,
- the density of the protrusions is preferably 70 mm 2 or more and 500 00 or less Zmm 2 .
- the other main surface opposite to the one main surface on which the cylindrical lens body is provided has a height of 0.20 m or more from the average center plane.
- a protrusion is further provided, It is preferable that the average interval of I ⁇ part is not less than 50 / m and not more than 120 m.
- it is opposite to the main surface on which the cylindrical lens body is provided. It is preferable that a convex portion is further provided on the other main surface on the side, and the convex portion is provided so that the haze of the optical sheet is 60% or less in a state where the cylindrical lens body is not formed.
- a convex portion is further provided on the other principal surface opposite to the one principal surface on which the cylindrical lens body is provided, and the convex portion forms a cylindrical lens body. It is preferable that the haze of the optical sheet is 20% or less in a state where the optical sheet is not used.
- a convex portion is further provided on the other principal surface opposite to the principal surface on which the cylindrical lens body is provided, and the ten-point average roughness SR of the convex portion is provided.
- z is preferably 1 tm or more and 15 m or less.
- a convex portion is further provided on the other principal surface opposite to the principal surface on which the cylindrical lens body is provided, and when the convex portion has a convex area of 1%.
- the height is preferably 1 m or more and 7 m or less.
- the other main surface opposite to the one main surface on which the cylindrical lens body is provided is further provided with a convex portion, and the surface on the side where the convex portion is provided It is preferable that the average gradient of the above is 0.25 or less.
- the optical sheet can refract and transmit more light incident from a direction perpendicular to the principal surface, and is oblique to the principal surface.
- the light incident from the direction can be totally reflected on one surface and then totally reflected or refracted through the other main surface to be returned light.
- the optical sheet can be used as a diffusion plate even when the optical sheet is provided on the diffusion plate. It can prevent sticking to.
- the directivity can be improved, the front luminance can be improved, and the characteristics can be improved by the polarization separation sheet in the subsequent stage. Can be improved.
- the front luminance can be improved, contributing to the improvement of the characteristics by the polarization separation sheet in the subsequent stage, along with the reduction in power consumption.
- the display brightness of the LCD panel can be improved.
- FIG. 1 is a perspective view showing the appearance of a prism sheet
- FIG. 2 is a schematic view showing an XZ section of the prism sheet
- FIG. 3 is a liquid crystal display according to an embodiment of the present invention.
- FIG. 4 is a perspective view showing an example of the shape of a lens sheet according to an embodiment of the present invention
- FIG. FIG. 6 is a schematic diagram showing an example of the configuration of an extrusion sheet precision molding apparatus used in the method for manufacturing a lens sheet according to an embodiment of the present invention.
- FIG. 6 is a schematic diagram showing a partially enlarged XZ section of a conventional prism sheet.
- Fig. 7, Fig. 7 is a distribution diagram showing the light distribution characteristics of the prism sheet of the conventional example
- Fig. 8 is a distribution diagram showing the visual field characteristics of the prism sheet of the conventional example
- Fig. 9 is a lens diagram of the first embodiment.
- Fig. 10 is a schematic diagram showing a partially enlarged XZ cross-section.
- Fig. 10 is a schematic diagram showing a partially enlarged XZ cross-section.
- FIG. 10 is a distribution diagram showing the light distribution characteristics of the lens assembly of Example 1.
- Fig. 11 is the XZ of the lens sheet of Example 2.
- Schematic diagram showing a partially enlarged cross-section Fig. 1 2 is a distribution diagram showing the light distribution characteristics of the lens sheet of Example 2
- Fig. 1 3 is a partial XZ cross-section of the lens sheet of Example 3.
- Fig. 14 is an enlarged schematic diagram.
- Fig. 14 is a distribution diagram showing the light distribution characteristics of the lens sheet of Example 3.
- Fig. 16 is a schematic diagram showing a partially enlarged XZ section of the lens sheet of Example 4
- Fig. 16 is a distribution diagram showing the light distribution characteristics of the lens sheet of Example 4
- Fig. 17 is an example.
- FIG. 18 is a schematic diagram showing a partially enlarged XZ section of the lens sheet of Fig. 5.
- Fig. 18 is a schematic diagram showing the field of view characteristics of the lens sheet of Example 5.
- Fig. 19 is the lens sheet of Example 6.
- Fig. 20 is a schematic diagram showing a partially enlarged XZ section
- Fig. 20 is a distribution diagram showing the visual field characteristics of the lens sheet of Example 6
- Fig. 21 is an XZ section of the lens sheet of Example 7.
- FIG. 22 is a distribution diagram showing the orientation characteristics of the lens sheet of Example 7
- Fig. 30 is a table showing the evaluation results of the lens sheet
- Fig. 31 is Table showing evaluation results of lens sheet
- 3 Fig. 2 is a graph showing the relationship between the number of projections of 0.2 or more and the relative luminance value
- Fig. 3 3 shows the relationship between the number of projections of 0.2 m or more and the appearance blur.
- Fig. 34 is a graph showing the relationship between the interval between the convex portions of 0.2 or more and the relative luminance value
- Fig. 35 is the relationship between the interval of the convex portions of 0.2 or more and the sliding test result.
- a graph showing the relationship Fig. 36 is a graph showing the relationship between the distance between convex portions of 0.2 m or more and appearance blur
- Fig. 37 is a graph showing the relationship between the ten-point average roughness SR z and the relative luminance value.
- Fig. 38 shows the relationship between the ten-point average roughness SR z and the sliding test results.
- Fig. 39 shows the relationship between the height when the convex area is 1% and the relative luminance value.
- Fig. 40 is a graph showing the relationship between the height when the convex area is 1% and the sliding test result
- Fig. 41 is a graph showing the relationship between haze and relative luminance value
- Fig. 4 2 The figure shows the average slope and It is a graph showing the relationship between the degrees Relative value.
- FIG. 3 is a cross-sectional view showing one structural example of a liquid crystal display device according to one embodiment of the present invention.
- the liquid crystal display device includes a backlight 1 and a liquid crystal panel 2.
- the backlight 1 is a direct type will be described, but the backlight 1 may be an edge-light type (side-light type).
- the backlight 1 is for supplying light to the liquid crystal panel 2. Yes, it is placed directly under the LCD panel 2.
- the liquid crystal panel 2 is for displaying information by temporally and spatially modulating the light supplied from the backlight 1.
- Polarizers 2 a and 2 b are provided on both sides of the liquid crystal panel 2.
- the polarizing plate 2 a and the polarizing plate 2 b allow only one of orthogonally polarized components of incident light to pass through and block the other by absorption.
- the polarizing plate 2 a and the polarizing plate 2 b are provided so that their transmission axes are orthogonal to each other.
- the knock light 1 includes, for example, a reflecting plate 1 1, one or a plurality of light sources 1 2, a diffusing plate 1 3, a diffusing sheet 1 7, a lens sheet 14, and a reflective polarizer.
- the light source 1 2 is for supplying light to the liquid crystal panel 2, for example, a fluorescent lamp (FL), an EL (Electro Luminescence), or an LED (Low Emit ting Diode ode).
- the reflecting plate 1 1 is provided so as to cover the lower side and the side of the one or more light sources 1 2 and reflects the light emitted from the one or more light sources 1 2 to the lower side and the side.
- the liquid crystal panel 2 is directed to the direction.
- a chassis may be provided in place of the reflector 11.
- the diffusing plate 1 3 is provided above the one or more light sources 1 2 and diffuses the light emitted from the one or more light sources 1 2 and the reflected light from the reflecting plate 1 1 to make the luminance uniform. It is.
- the diffusion sheet 17 is provided on the diffusion plate 13 and serves to diffuse at least the light diffused by the diffusion plate 17. Further, the diffusion sheet 17 may further have a function of condensing light.
- a lens sheet 14 as an example of an optical sheet is provided above the diffusion sheet 13 to improve the directivity of irradiation light and the like.
- the reflection type polarizing plate 18 is provided on the lens sheet 14 and the lens sheet. Of the light whose directivity has been enhanced by 14, only one of the orthogonal polarization components is allowed to pass and the other is reflected.
- FIG. 4 is a perspective view showing an example of the shape of the lens sheet 14 according to the embodiment of the present invention.
- the lens sheet 14 has a sheet shape.
- the lens sheet 14 When the lens sheet 14 is viewed from the main surface side, the lens sheet 14 has, for example, a rectangular shape.
- the sheet includes not only a film but also various thin plates having flexibility or a certain degree of hardness.
- one main surface on the side where light from the light source 12 enters is referred to as a back surface
- the other main surface on the side from which light from the light source 12 is output is referred to as a front surface.
- a plurality of convex portions 16 are provided on the back surface side of the lens sheet 14, and a high-order aspheric cylindrical lens body 15, which is symmetrical on the front surface side of the lens sheet 14, is provided on the aspherical generatrix. Are provided continuously in the vertical direction.
- the cylindrical lens body 15 has a focal length fa on the side from which the light from the light source 12 is emitted.
- the X axis is parallel to the column direction of the cylindrical lens body 15 and the Y axis is parallel to the generatrix direction of the cylindrical lens body 15. Take the Z axis parallel to the line direction.
- Lens sheet 1 Cylindrical lens body provided on the front side of 4 1
- the width of 5, that is, the structural unit width (pitch) D is selected from the range of 10 to 120 zm, and is preferably selected according to the pixels of the liquid crystal panel.
- the structural unit width D is preferably selected from the range of 50 to 100 ⁇ .
- the structural unit width D is preferably in the range of 10 to 80 m. Choose.
- the lens sheet 14 is provided between the diffusion sheet 1 3 and the liquid crystal panel 2 such that the side on which the plurality of cylindrical lens bodies 15 are provided faces the liquid crystal panel 2.
- the XZ cross-sectional shape of the cylindrical lens body 15 satisfies the following formula (1).
- R is the radius of curvature of the apex of the cylindrical lens body 15
- K is the conic constant
- A, B, C ⁇ are aspheric coefficients.
- T means the square root of the value determined by the following formula.
- the numerical value in such a range the directivity of the illumination light can be improved.
- Equation (1) the radius of curvature R of the tip apex, the conic constant K, the aspherical coefficients A, B, C * ⁇ ⁇ are expressed as 0 ⁇ 3 0 one 1 5 ° K ⁇ one 1, R- K ⁇ 5, 0 ⁇ a, B, it is preferable that the numerical range of C * ⁇ ⁇ ⁇ 1 0- 3 . By setting the numerical value in such a range, the directivity of the illumination light can be increased.
- the radius of curvature R of the tip apex and the conic constant K are set as 0 ⁇ R ⁇ 1 2 m, ⁇ 1 5 ⁇ K ⁇ -1 3 ⁇ 4 RK ⁇ 5, 0 ⁇ a, B, it is preferable that the numerical range of C ⁇ ⁇ 'Ku 1 O-3.
- the radius of curvature R of the tip vertex and the conic constant K are set to 0 ⁇ R ⁇ 48 m, 1 1 5 K ⁇ 1 1, RK ⁇ 5, 0 ⁇ a, B, it is preferable that the numerical range of C ⁇ ⁇ ⁇ 1 0- 3 .
- the height of the convex portion 16 provided on the back surface of the lens sheet 14 is preferably at least 0.20 m from the average center plane (JISB 0 60 1—199 94). Further, the density of the convex portions 16 having a height of 0.20 m or more from the average center plane is preferably in the range of 70 pieces / mm 2 or more and 500 pieces Zmm 2 or less. In addition, the average interval between the convex portions 16 having a height of 0.20 m from the average center plane is preferably in the range of 50 m or more and 120 m or less.
- the convex portion 16 provided on the back surface of the lens sheet 14 may be provided so that the haze of the lens sheet 14 is 60% or less in a state where the cylindrical lens body 15 is not formed.
- the lens sheet 14 is provided so that the haze of the lens sheet 14 is 20% or less.
- the convex portion 16 provided on the back surface of the lens sheet 14 is preferably provided so that the ten-point average roughness S R z is in the range of 1 m to 15 m. Further, the convex portion 16 on the one main surface side of the lens sheet 14 is preferably provided so that the height when the convex portion is 1% of the convex portion area is 1 or more and 7 or less.
- this extruded sheet precision forming apparatus includes an extruder 21, 1: die 2 2, forming roll 2 3, a coasting roll 24 and a cooling port 25.
- At least one type of transparent thermoplastic resin is used to form the lens case 14.
- a thermoplastic resin having a refractive index of 1.4 or more examples include polycarbonate resins, acrylic resins typified by polymethyl methacrylate, polyester resins typified by polyethylene terephthalate, amorphous copolymer polyester resins, polystyrene resins, and polyvinyl chloride resins. Etc.
- the melt viscosity in the vicinity of the molding temperature is preferably 1 O O O Pa or more and 100 00 or less Pa.
- thermoplastic resin e.g., polystyrene resin
- a release agent in this way, the adhesiveness between the forming roll 23 and the sheet when the sheet is peeled off from the forming nozzle 23 can be adjusted, and a peeling line can enter the lens base 14. Can be prevented.
- the amount of release agent added to the thermoplastic resin is preferably in the range of 0.02 1:% to 0.4 wt%. If it is less than 0.02 wt%, the releasability deteriorates, and a peeling line enters the lens sheet 14. On the other hand, if it exceeds 0.4 wt%, the releasability becomes too good, and the transparent thermal effect resin is peeled off on the forming roll 23 before solidifying, so that the shape of the cylindrical lens body 15 is A failure that collapses will occur. Further, it is preferable that at least one ultraviolet absorber or light stabilizer is contained in the thermoplastic resin. By including the ultraviolet absorber or the light stabilizer in this way, the hue change due to light irradiation from the light source can be suppressed.
- the amount of the ultraviolet absorber or light stabilizer added to the thermoplastic resin is preferably 0.02 wt% or more and 0.4 wt% or less. If it is less than 0.02w t%, the hue change cannot be suppressed. On the other hand, if it exceeds 0.4 wt%, the lens sheet 14 becomes yellowish.
- UV absorbers examples include salicylic acid-based, benzophenone-based, benzotriazole-based, and cyano-acryl®-based UV absorbers such as ADK STAB LA-31, ADK STAB LA-32 ), Cyasorb UV—541 1 (Sanchemical Co., Ltd.), T i nu vin P, T i nuv in 234, T inuvin 320, T i nuv in 327, T i nuv in 327 ), Sum isorbll O, Sum isorbl 40 (manufactured by Sumitomo Chemical Co., Ltd.), Kem isorbll O, Kem isorbl 40, Kem isorbl 2, Kem isorbl 3 (manufactured by Chemipro Chemical Co., Ltd.), XJv i nu l X— 1 9, Uv i nu l Ms— 40 (BASF), Tomisorp 100, Tomisorp 600 (Yoshitomi Pharmaceutical Co., Ltd.), V i
- light stabilizers include hindered amines. Specifically, for example, ADK STAB LA-52 (manufactured by Asahi Denka Kogyo Co., Ltd.), Sanol LS-770, Sanol LS-765, Sanol LS 774 (Sankyo) And Sumi sor bTM-061 (manufactured by Sumitomo Chemical Co., Ltd.).
- ADK STAB LA-52 manufactured by Asahi Denka Kogyo Co., Ltd.
- Sanol LS-770 Sanol LS-765
- Sanol LS 774 Sanol LS 774
- Sumi sor bTM-061 manufactured by Sumitomo Chemical Co., Ltd.
- thermoplastic resin In addition to the mold release agent and ultraviolet absorber described above, an antioxidant, a belt Additives such as antistatic agents, colorants, plasticizers, compatibilizers, and flame retardants can also be added. However, most additives cause gas generation during the heating of melt extrusions such as T-die 22 and deteriorate the film-forming property and work environment.
- the amount added to the thermoplastic resin is preferably 2 wt% or less.
- the extruder 21 melts the resin material supplied from a hopper (not shown) and supplies it to the T die 22.
- the T-die 22 is a die having a letter-shaped opening, and the resin material supplied from the extruder 21 is expanded to the sheet width to be molded and discharged.
- the forming roll 23 has a cylindrical shape and is configured to be rotationally driven with its central axis as a rotation axis. Further, the forming rolls 23 are configured to be cooled. Specifically, the forming roll 23 has one or more flow paths for flowing a cooling medium therein. For example, an oil medium is used as the cooling medium, and the oil medium is changed, for example, between 120 ° C. and 230 ° C.
- the cylindrical surface of the forming roll 23 is provided with a sculpture shape for transferring a fine pattern onto a sheet discharged from the T die 22.
- This engraving shape is, for example, a fine uneven shape for transferring the cylindrical lens body 15 to a sheet.
- This uneven shape is formed, for example, by precision cutting with diamond-by.
- the engraving shape is formed in the circumferential direction or the width direction (height direction) of the forming roll 23 having a cylindrical shape.
- the elastic roll 24 has a cylindrical shape and is configured to be capable of rotating by using the central axis as a rotation axis.
- the surface of the coasting roll 24 can be elastically deformed. When a sheet is nipped between the forming roll 23 and the elastic roll 24, the surface in contact with the forming roll 23 is crushed. Natsu.
- the elastic roll 24 is covered with a seamless tube made of, for example, Ni plating, and an elastic body for making the surface of the elastic roll 24 deformable by inertia is provided inside.
- the configuration and material of the inertia roll 24 are not limited as long as the surface of the inertia roll 24 is deformed by inertia when contacting the forming roll 23 with a predetermined pressure.
- the material for example, a rubber material, a metal, or a composite material can be used.
- the elastic mouthpiece 24 is not limited to a roll shape, and a belt shape can also be used.
- the cylindrical surface of the elastic roll 24 is provided with a concave portion for forming the convex portion 16 on the back surface side of the lens sheet 14.
- the elastic roll 24 is configured to be cooled.
- the elastic roll 24 has one or more flow paths for flowing a cooling medium therein.
- a cooling medium For example, water can be used as the cooling medium.
- a pressurized hot water type temperature controller (not shown), for example, the basic temperature is set to 80 ° C and 13 ° C.
- An oil temperature controller may be used as the temperature controller.
- the cooling roll 25 has a cylindrical shape, and is configured to be rotationally driven with its central axis as a rotation axis.
- the cooling roll 25 is configured to be cooled.
- the cooling roll 25 has one or more flow paths for flowing a cooling medium therein.
- a cooling medium For example, water can be used as the cooling medium.
- a pressurized hot water type temperature controller (not shown), for example, the basic temperature is set to 1 15 ° C.
- An oil temperature controller may be used as the temperature controller.
- the resin material is melted by the extruder 21, sequentially supplied to the T die 22, and the sheet is continuously discharged from the T die 22.
- the sheet discharged from the T die 22 is nipped by the forming roll 23 and the elastic roll 24.
- the engraving shape of the molding tool 23 is transferred to the surface of the sheet, and the uneven shape of the coasting roll 24 is transferred to the back surface of the sheet.
- the surface temperature of the molding die 23 is maintained in a temperature range of Tg + 20 ° C to Tg + 45 ° ⁇ , and the surface temperature of the elastic roll 24 is 20 ° C to Tg ° C. Maintained in the temperature range.
- Tg is the glass transition temperature of the resin material.
- the temperature of the resin material when transferring the engraving shape is preferably Tg + 50 ° C to Tg + 230 ° C, and Tg + 80 ° C to Tg + 20 O. Is more preferable.
- the engraving shape can be satisfactorily transferred to the sheet.
- the sheet roll is peeled off from the forming roll 23 by the cooling roll 25 while the sheet roll is suppressed by the forming roll 23 and the cooling port 25 to suppress fluttering.
- the surface temperature of the cooling roll 25 is maintained in a temperature range of Tg or less.
- the surface temperature of the cooling roll 25 is maintained in such a temperature range, and the sheet is nipped by the forming roll 23 and the cooling port 25 to suppress fluttering. It can peel well.
- the temperature of the resin material at the time of peeling is preferably Tg or more, more preferably Tg + 20 ° C to Tg + 85 ° C, and Tg + 30 ° (: to Even more preferably, Tg + 60 ° C. While maintaining the temperature of the resin within the above-mentioned temperature range, The sheet can be peeled well from the forming roll 23 by suppressing the fluttering by niping the sheet with the rollers 2 and 3 and the cooling roll 25. As described above, the target lens case can be obtained.
- Conventional lens sheet manufacturing methods mainly use a film substrate such as polyethylene terephthalate (PET) formed with a lens shape using UV (ultraviolet) curable resin (eg UV curable acrylic resin).
- PET polyethylene terephthalate
- UV curable resin eg UV curable acrylic resin
- This method has the problem that the UV curable resin is expensive or the production speed is slow because it is necessary to sufficiently irradiate the UV curable resin to cure the resin in the process. .
- the lens sheet manufacturing method can reduce the material by using an integrally molded product by thermal transfer of a thermoplastic resin, and can improve the productivity of the lens sheet. It is possible to achieve a special effect that sheet warpage can be suppressed.
- the inventor determines the radius of curvature R, the conic constant K, The numerical values of the aspherical coefficients A, B, and C ′ ⁇ were changed and examined by simulation. The details of the study are described below.
- Figure 6 shows a partially enlarged X-section of the conventional prism sheet.
- the prism sheet has a plurality of continuous small prisms.
- point A indicates the apex of the prism
- points B and C are Indicates the junction point with the adjacent prism
- point O indicates the virtual light origin immediately below vertex A
- point P indicates the virtual light origin immediately below junction point B.
- vertex A The plane between point B is called AB plane
- the plane between vertex A and junction C is called AC plane.
- Figure 6 shows the locus of the light flux ⁇ incident on the A B plane from the virtual light source O, and the locus of the light flux ⁇ incident on the A B and A C surfaces from the virtual light source P.
- the trajectories of these luminous flux ⁇ and luminous flux ⁇ were obtained by simulation.
- the same or corresponding parts are denoted by the same reference numerals.
- Fig. 7 shows the light distribution characteristics of the conventional prism sheet.
- Figure 8 shows the visual field characteristics of the conventional prism sheet.
- the distribution surrounded by the frame t 1 corresponds to the primary transmitted light
- the distribution surrounded by the frame t 2 is the secondary transmitted light. It corresponds to.
- the distribution chart in Fig. 7 shows that the center is 0 °, the first circle from the center is 10 °, the second circle is 20 °, and so on, and the outermost circle is 9 °. Indicates 0 °.
- the distribution charts in Fig. 7 and Fig. 8 are drawn by computer simulation. The distribution map of the embodiment described below is also based on the simulation.
- the triangular prism described above is melt-extruded on one main surface of the sheet.
- the shape was evaluated.
- an elastic roll was produced as follows.
- a seamless tube with a thickness of 3400 microns is formed by forming a seamless tube with Ni plating, polishing the surface with Cr plating, and polishing to 0.2 S (hereinafter referred to as a flexible sleeve). ) was produced.
- an elastic body is affixed on a roll through which a cooling medium can pass, and a flexible sleeve is placed on the roll, and an elastic mouth having a configuration in which cooling water can flow between the elastic body and the flexible sleeve is obtained.
- the elastic body nitrile rubber (N B R) having a hardness of 85 degrees was used, and its thickness was 20 mm.
- the diameter ⁇ of the elastic roll was 2600 mm, and the surface length (width of the forming roll) was 4500 mm.
- a forming roll having a structure capable of reducing the temperature distribution by flowing a cooling medium through a plurality of flow paths was prepared.
- the material is quenched and tempered with S 4 5 C, and after mirror finish (0.5 S or less), electroless Ni P (nickel / phosphorus) plating (thickness: 100 microns) went.
- An engraving shape was formed on the cylindrical surface of this forming roll as follows. First, a diamond tool having a predetermined shape was set on an ultra-precision lathe in which a forming roll was placed in a constant temperature and humidity room (temperature 23 ° C, humidity 50%). And the lens pattern of the above-mentioned triangular prism was formed in the circumferential direction of the forming roll.
- the forming roll had a diameter of ⁇ 30, a surface length of 4600 mm, and a groove processing width of 300 mm.
- An oil medium was used as a cooling medium for the forming roll.
- Water is used as the cooling medium for the elastic roll and cooling roll, and a pressurized hot water type temperature controller is used. Used to adjust the temperature of the cooling medium.
- the extruder used was a vented screw with a diameter of 50 mm and no gear pump.
- the T-die used was a coach hanger type die with a lip width of 55 mm and a lip gap of 1.5 mm.
- the air gap was 105 mm.
- the lens sheet was molded using the extruded sheet precision molding apparatus having the above-described configuration.
- polycarbonate E 2 00 0 R manufactured by Mitsubishi Engineering Plastics
- T g the glass transition temperature of the polycarbonate resin
- seat was peeled from the forming roll with the cooling roll.
- the surface temperature of the cooling roll was kept at 1 15 ° C.
- the speed of the take-up machine was 7 m / min. As a result, a lens sheet having a thickness of 2 20; am in which grooves were transferred to one main surface was obtained.
- the surface temperature of the above-described molding nozzle and elastic roll is measured at a position immediately before the nip where the sensor is brought into contact with the roll surface and hardly affected by the heat of the resin.
- the surface temperature of the cooling roll is measured at a position where the sensor is brought into contact with the surface of the cooling roll and the film is nipped between the cooling roll and the forming roll.
- a handy type digital thermometer manufactured by Chinoichi Co., Ltd., trade name: ND 5 1 1—KHN
- This lens sheet is a lens sheet having a single finite focal length on the emission side of the illumination light and in which a number of symmetrical high-order aspherical cylindrical lens bodies are continuously arranged.
- Aspherical sectional shape, Z X 2 that meets the equation (1) (3 + (9 + X 2)) represented by + 1 0- 5 X 4.
- a large number of cylindrical lens bodies, which are aspherical surfaces, are continuously arranged, so that the light flux ⁇ can be refracted and transmitted to the front of the lens sheet. This contributes to improving the brightness in the front direction.
- the normal angle of the reflected light beam from the first total reflection surface (AB surface) forms a shallow angle with respect to the Z axis on the surface near the apex A on the AC side. Creates an effect that reflects and becomes the return light R.
- FIG. 10 shows the light distribution characteristics of the lens sheet of Example 1. As shown in FIG. 10, in the lens sheet of Example 1, the second-order transmitted light component T 2 is reduced as compared with the above-described conventional prism sheet.
- the overall refractive transmission effect forward from the vertical component direction and the refractive power and total reflection capacity for the incident light beam from the side surface direction are improved.
- the front luminance can be increased while increasing the primary transmitted light and maintaining the light distribution in the forward direction.
- the secondary transmitted light component T 2 can be suppressed and the added light to the return light component can be increased and light can be used effectively, the gain characteristics of the light can be improved.
- FIGS. 11 and 11 show a partially enlarged XZ section of the lens sheet of Example 2.
- This lens sheet has one finite focal length on the exit side of the illumination light, and a symmetrical high-order aspherical cylindrical lens body is continuously arranged.
- the cross-sectional shape is a curved surface with a large curvature compared to the cross-sectional shape of the lens sheet in Fig. 9, and the spread of the refracted transmitted light of the light flux ⁇ is changed, but the light is distributed forward.
- the secondary transmitted light component T 2 can be reduced.
- the change in the normal direction becomes larger, and the incident angle of the incident light beam becomes shallower, so the refraction effect is reduced, but the forward light distribution is not impaired.
- FIG. 12 shows the light distribution characteristics of the lens sheet of Example 2.
- the second-order transmitted light component T 2 is reduced as compared with the above-described conventional prism sheet.
- the shape of the toroidal lens body represented by 5 X 4 was compared, and as a result, it was found that both had almost the same shape.
- FIG. 13 shows a partially enlarged X-cross section of the lens sheet of Example 3.
- This lens sheet has one finite focal length on the exit side of the illumination light, On the right, f-order high-order aspherical cylindrical lens bodies are continuously arranged.
- a part of the luminous flux ⁇ emitted from the virtual light origin 0 is totally reflected on the surface near A, and the front luminance can be supplementarily improved as a return light component R. .
- the total reflection and refraction ability of the light beam emitted from the virtual light source P increases the efficiency that can be used as the return light component R, thereby mitigating the generation of the second transmitted light beam component T2.
- FIG. 14 is a distribution diagram showing the light distribution characteristics of the lens sheet of Example 3.
- the second-order transmitted light component T 2 is reduced as compared with the above-described conventional prim sheet.
- the shape of the toroidal lens body represented by 5 X 4 was compared. As a result, it was found that both had almost the same shape.
- FIG. 15 shows a partially enlarged XZ section of the lens sheet of Example 4.
- This lens sheet has a single finite focal length on the illumination light exit side, and a symmetrical high-order aspheric cylindrical lens body is continuously arranged.
- a part of the luminous flux ⁇ emitted from the virtual light source O is totally reflected on the surface near A, and the front luminance can be supplementarily improved as a return light component R. .
- the total reflection and refraction ability for the light flux ⁇ emitted from the virtual light source P can increase the efficiency used for the return light component R and reduce the generation of the second transmitted light flux component T2.
- FIG. 16 shows the light distribution characteristics of the lens sheet of Example 4. As shown in FIG. 16, in the lens sheet of Example 4, the prism sheet of the conventional example described above is used.
- FIG. 20 shows the visual field characteristics of the lens sheet of Example 5.
- the effect of the lens sheet on the light flux ⁇ incident from the vertical direction will be described.
- all of the incident light flux ⁇ is refracted and transmitted in front of the lens sheet.
- the effect that the light distribution ratio to the front direction of the sheet can be increased can be achieved. That is, in the lens sheet of Example 5, all of the primary transmitted light can be refracted and transmitted forward by the nonspherical shape provided on one main surface thereof, so that the characteristics of the primary transmitted light are improved. There is an effect that it can be improved.
- the effect of the lens sheet on the light flux ⁇ incident from the side direction will be described.
- a part of the light beam is totally reflected by the AB surface, and the total reflected light beam ⁇ is refracted or totally reflected on the AC surface so as to reduce the probability that the secondary transmitted light contributes to the generation of side rope light. Reflected to return light.
- the other part of the light flux ⁇ incident on the AB surface is Refracted and transmitted so that the transmitted light expands the viewing angle without affecting the light.
- the normal forms a shallow angle with respect to the Z axis near the vertex of the AC surface.
- the reflected light beam from the AB surface can be totally reflected near the apex of the AC surface to be returned light.
- the light beam incident on the apex A is a sidelobe light.
- the lens sheet of Example 5 out of the luminous flux ⁇ incident on the AC plane after being reflected by the AB plane, the luminous flux ⁇ incident near the apex A can be totally reflected to be returned light.
- the light flux ⁇ incident on the AC surface from the virtual origin P is distributed forward by the refraction effect of the curved surface, so that the viewing angle can be enlarged.
- the light beam ⁇ near the junction C which is a light beam in the side direction that can originally become sidelobe light, is refracted and transmitted through the AC surface and re-enters the adjacent aspheric surface to become return light. There is an effect that light can be suppressed.
- the entire front refracting transmission effect of the incident light flux ⁇ from the vertical direction, the refraction ability, the total reflection power, and the side light distribution return light effect for the incident light flux from the side direction. Can be improved. As a result, it is possible to increase the primary transmitted light and increase the front brightness while maintaining the light distribution in the forward direction, and to suppress the secondary transmitted light and produce the effect of widening the viewing angle. In addition, the contribution to the return light can be increased and the effective use of light can be realized (see Fig. 18).
- the shape was compared with the idal lens body. As a result, it was found that both had almost the same shape.
- FIG. 19 shows a partially enlarged XZ section of the lens sheet of Example 6.
- FIG. 20 shows the visual field characteristics of Example 6® lens sheet.
- the shape of the toroidal lens body represented by 5 X 4 was compared. As a result, it was found that both had almost the same shape.
- FIG. 21 shows a partially enlarged XZ section of the lens sheet of Example 7.
- FIG. 22 shows the orientation characteristics of the lens sheet of Example 7. Emit light
- the cross section of the cylindrical lens body provided on the side surface is an aspheric cross section having a finite focal length.
- the shape of the toroidal lens body represented by 5 ⁇ 4 was compared. As a result, it was found that both had almost the same shape.
- the viewing angle based on the half-value width with respect to the front luminance is as follows.
- the conventional prism sheet has a problem that the viewing angle is about 100 ° and the viewing angle is narrow, whereas the lens sheets of Examples 5 to 7 have a viewing angle of 1 It has an advantage of a wide viewing angle of about 50 °. That is, in the lens sheets of Examples 5 to 7, the viewing angle can be greatly improved as compared with the conventional prism sheet. An excellent effect can be achieved.
- Equation (1) 0 ⁇ R ⁇ 30, R—K ⁇ 5, 1 1 ⁇ 5 ⁇ —1, 0 ⁇ A, B, C- ⁇ ' ⁇ 1 0— It can be seen that the following effects can be obtained by setting 3 . That is, (1) the highest luminance can be achieved in the front direction, (2) a high luminance distribution can be realized in a direction within a predetermined viewing angle, and (3) secondary transmitted light can be suppressed. I understand.
- Equation (1) R ⁇ 0, K 1, 0 0 A ⁇ 1 0 ⁇ 3 , 0 ⁇ B, C ⁇ ⁇ ⁇ 1 0 ⁇ 3 It can be seen that the following effects can be obtained. (1) The highest luminance in the front direction can be achieved, (2) A high luminance distribution can be realized in the direction within a predetermined viewing angle, (3) Secondary transmitted light can be suppressed, (4 ) You can see that the viewing angle can be enlarged.
- an elastic roll was produced as follows.
- a seamless tube with a thickness of 3400 microns is formed by forming a seamless tube with Ni plating, and applying Cr plating to the surface and then polishing to 0.2 S. Sleeve).
- the outer peripheral surface of this flexible sleeve was processed with stainless steel (SUS material).
- glass beads having a predetermined particle diameter (straight diameter) were driven into the flexible sleeve by a Fujis Manufacturing machine blasting machine to form an uneven shape on the outer peripheral surface of the flexible sleeve.
- the angle of punching was about 30 ° with respect to the perpendicular to the outer peripheral surface of the flexible sleeve.
- an elastic body was affixed on a roll through which a cooling medium can pass, and a flexible sleeve was placed on the elastic body to obtain an elastic roll having a configuration in which cooling water can flow between the elastic body and the flexible sleeve.
- nitrile rubber (N B R) having a hardness of 85 degrees was used, and its thickness was 20 mm.
- the diameter ⁇ of the elastic roll was 2600 mm, and the surface length (width of the forming roll) was 4500 mm.
- the elastic roll obtained as described above was attached to an extrusion sheet punch precision molding device, and a lens sheet was produced as follows.
- polycarbonate E 2 00 0 R manufactured by Mitsubishi Engineering Plastics Co., Ltd. was continuously discharged from a T die, nipped by a forming roll and an elastic mouth, and then wound around a forming roll.
- the surface temperature of the molding die is kept at T g + 35 ° C, and the surface temperature of the elastic roll 14 is 7 Hold at 5 ° ⁇ .
- T g is the glass transition temperature of the polycarbonate resin.
- seat was peeled from the forming roll with the cooling roll.
- the surface temperature of the cooling roll was kept at 115 ° C.
- the speed of the take-up machine was 7 mZm i n.
- the surface temperature of the above-described forming roll and elastic roll was measured at a position immediately before the nip where a sensor is brought into contact with the roll surface and hardly affected by the heat of the resin.
- the surface temperature of the cooling roll is measured at a position where a sensor is brought into contact with the surface of the cooling roll and the sheet is nipped by the cooling roll and the forming roll.
- a handheld digital thermometer manufactured by Chinoichi Co., Ltd., trade name: ND 5 1 1-KHN
- a sensor a sensor for measuring the surface temperature (manufactured by Anritsu Keiki Co., Ltd., trade name U) — 1 6 1 K— 0 0— D 0— 1) was used.
- the average spacing of the convex portions having a height of 0.2 m from the above average center plane was obtained.
- the 10-point average roughness S R z was calculated by averaging the difference between the maximum height of 5 points and the maximum valley height of 5 points from the average center plane.
- the ratio of the total area of the cross section obtained by cutting the convex part parallel to the center plane is 1% of the projection area. Sought height. In the range of 1 0 0 0 wmX 5 0 0 ⁇ , the height at which the cross-sectional area reaches an area ratio of 1% (5 0 0 0 nm z ) was obtained.
- a lens sheet was attached to (television). Specifically, on the unit containing the cold cathode fluorescent lamp (CC FL), a diffuser plate for the purpose of mixing and non-uniformity of light and the lens sheet of the example are sequentially mounted to form a backlight system. Install the LCD panel on the package system to display the LCD A sample was obtained. The front luminance of the liquid crystal display device was measured with CS-1100 manufactured by Konica Minolta.
- a lens sheet manufactured in the same manner as in the example except for omitting the formation of the convex portion on the back surface side is similarly attached to a commercially available 19-inch TV manufactured by Sony to obtain a liquid crystal display device.
- the front luminance of the liquid crystal display device was measured with CS-1100 manufactured by Konica Minolta.
- the relative value of the front luminance of the former liquid crystal display device was obtained based on the front luminance of the latter liquid crystal display device.
- a lens roll is prepared in the same manner as in Examples 15 to 25 except that a molding roll having a mirror-like molding surface is prepared and a lens sheet is produced using this molding roll. A lens sheet having an uneven shape on the back side was obtained.
- the average slope is defined by placing the orthogonal coordinate axes X and Y on the center of the roughness curve, the axis perpendicular to the center plane as the Z axis, the roughness curved surface f (x, y), the reference plane size L x, L y is given by the following equation.
- FIG. 30 and FIG. 31 show the evaluation results obtained as described above.
- the numbers in the judgment result column of the sliding test indicate the following judgment results.
- FIG. 3 2 is a graph showing the relationship between the number of protrusions greater than 0.2 and the relative luminance value.
- FIG. 33 is a graph showing the relationship between the number of protrusions of 0.2 or more and the appearance blur.
- FIG. 34 is a graph showing the relationship between the interval between convex portions of 0.2_tm or more and the relative luminance value.
- FIG. 35 is a graph showing the relationship between the interval between convex portions of 0.2 nm or more and the sliding test result.
- Fig. 36 is a drawing showing the relationship between the distance between convex parts of 0.2 m or more and the appearance blur.
- FIG. 37 is a graph showing the relationship between the ten-point average roughness SR z and the relative luminance value.
- FIG. 38 is a graph showing the relationship between the ten-point average roughness SR z and the sliding test results.
- FIG. 39 is a graph showing the relationship between the height at a convex area of 1% and the relative luminance value.
- FIG. 40 is a graph showing the relationship between the height when the convex area is 1% and the sliding test result.
- Figure 41 shows the haze and luminance phase. It is a graph which shows the relationship with a pair value.
- Fig. 42 is a graph showing the relationship between the average slope and the relative luminance value.
- the average interval between the convex portions is set to 50 or more, thereby suppressing the decrease in luminance of the liquid crystal display device by providing the convex portions on the back side of the lens sheet I understand that I can do it.
- the average distance between the convex parts can be reduced to 120 m or less so that the back of the lens sheet It can be seen that scratches can be prevented from occurring on the surface of the diffusion plate, and that the appearance bleeding due to interference with the flat portion of the diffusion plate provided on the back side of the lens sheet can be improved.
- the ten-point average roughness SR z value of the convex portion is set to 1 m or more, so that the lens It can be seen that the surface of the diffusion plate can be prevented from being scratched by the back surface of the lens, and that the appearance bleeding due to interference with the flat portion of the diffusion plate provided on the back surface side of the lens sheet can be improved. Also, based on the evaluation result of the front luminance relative value (see Fig. 37), the convex portion is provided on the back side of the lens sheet by setting the ten-point average roughness SR z of the convex portion to 15 or less. It can be seen that the decrease in the brightness of the liquid crystal display device due to can be suppressed.
- the back surface of the lens sheet can prevent the surface of the diffusion plate from being scratched, and that the appearance bleeding due to interference with the flat portion of the diffusion plate provided on the back surface side of the lens sheet can be improved.
- the height of the convex area is 1 z% or less, so that the convex portion is provided on the back side of the lens sheet. It can be seen that the decrease in the brightness of the liquid crystal display device due to can be suppressed.
- the present invention is not limited to the above-described embodiment of the present invention, and various modifications and applications can be made without departing from the gist of the present invention.
- the same front luminance improvement effect can be obtained by disposing the light guide plate above the light guide plate.
- the same effect can be obtained by arranging a lens sheet on the exit side from the light guide plate of the pack rye or placing a lens sheet on the front side of the incident side of the liquid crystal panel. You can play.
- the backlight 1 is not limited to the above-described embodiment, but is a light guide plate, EL (Electroluminescence) light emitting surface, surface emitting CCFL (cold cathode fluorescent tube), or other A configuration may be adopted in which a lens sheet 14 is provided above the light source. Also in this case, the same front luminance improvement effect as in the above-described embodiment can be obtained.
- the lens sheet may be produced by a hot press method.
- a hot press method For example, a commercially available bead blasting or sand blasting machine is used for the surface on which the back surface of the press plate is molded, and the uneven shape is produced by changing the type of grain, grain size and shot speed.
- the press plate obtained in this way and the press plate provided with the concave and convex shapes for forming the cylindrical lens body the thermoplastic resin is vacuum-heated, so that the lens sheet is obtained. Obtainable.
- a method for producing a lens sheet by the melt extrusion method will be specifically described below.
- the driving angle is set to an angle of about 30 ° from the vertical direction of the SUS plate.
- press molding at 1700 ° ⁇ 1 0 3 ⁇ (: 111 2 for 10 minutes and cooling to room temperature.
- the target lens sheet is obtained.
- the case where the convex portion 16 is provided on the cylindrical surface of the elastic roll 24 and the convex portion 16 is formed on the back surface of the lens sheet 14 is shown as an example.
- the shape of the cylindrical surface of 4 is not limited to this.
- the cylindrical surface of the elastic roll 24 may be mirror-like.
- a protective sheet may be further provided in the liquid crystal display device in order to prevent the lens sheet 14 from being damaged.
- One main surface of the protection sheet is a flat surface, and the other main surface is a concavo-convex shape provided with a convex portion in the same manner as the back surface of the lens sheet 14.
- the protective sheet is provided on the liquid crystal display device so that the surface on which the convex portion is provided faces the light source 12. Protrusions should be provided on both sides of the protective sheet. May be used.
- This protective sheet can be provided, for example, between the lens sheet 14 and the reflective polarizing plate 18. Further, a protective sheet may be provided instead of the reflective polarizing plate 18.
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Abstract
Description
Claims
Priority Applications (5)
Application Number | Priority Date | Filing Date | Title |
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JP2006537864A JP5272309B2 (ja) | 2004-09-30 | 2005-09-30 | 光学シート、バックライトおよび液晶表示装置 |
EP05790112A EP1795923A4 (en) | 2004-09-30 | 2005-09-30 | OPTICAL SHEET, TAIL LIGHT AND LIQUID CRYSTAL DISPLAY DEVICE |
KR1020067018984A KR101090387B1 (ko) | 2004-09-30 | 2005-09-30 | 광학 시트, 백라이트 및 액정 표시 장치 |
CN2005800122489A CN1947034B (zh) | 2004-09-30 | 2005-09-30 | 光学片材、背光装置和液晶显示设备 |
US10/598,725 US7695167B2 (en) | 2004-09-30 | 2005-09-30 | Optical sheet, backlight and liquid crystal display apparatus |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2004288518 | 2004-09-30 | ||
JP2004-288518 | 2004-09-30 |
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WO2006036032A1 true WO2006036032A1 (ja) | 2006-04-06 |
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PCT/JP2005/018588 WO2006036032A1 (ja) | 2004-09-30 | 2005-09-30 | 光学シート、バックライトおよび液晶表示装置 |
Country Status (7)
Country | Link |
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US (1) | US7695167B2 (ja) |
EP (1) | EP1795923A4 (ja) |
JP (1) | JP5272309B2 (ja) |
KR (1) | KR101090387B1 (ja) |
CN (1) | CN1947034B (ja) |
TW (1) | TW200632466A (ja) |
WO (1) | WO2006036032A1 (ja) |
Cited By (11)
Publication number | Priority date | Publication date | Assignee | Title |
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US8553175B2 (en) | 2006-04-14 | 2013-10-08 | Sony Corporation | Optical sheet having irregularity portions, backlight device with optical sheet, and liquid crystal display device including a backlight device with optical sheet |
CN101819290A (zh) * | 2006-04-14 | 2010-09-01 | 索尼株式会社 | 光学片、背光装置及液晶显示装置 |
JP2007286261A (ja) * | 2006-04-14 | 2007-11-01 | Sony Corp | 光学シート、バックライト装置および液晶表示装置 |
JP2008122525A (ja) * | 2006-11-09 | 2008-05-29 | Sony Corp | 光学シート積層体および液晶表示装置 |
JP2008243637A (ja) * | 2007-03-28 | 2008-10-09 | Sumitomo Chemical Co Ltd | 光拡散板及び面光源装置並びに液晶表示装置 |
KR100895489B1 (ko) * | 2007-06-08 | 2009-05-06 | 주식회사 세스코 | 해충 포획장치 |
JP2009276616A (ja) * | 2008-05-15 | 2009-11-26 | Dainippon Printing Co Ltd | 光学シート、面光源装置、透過型表示装置 |
JP2009300870A (ja) * | 2008-06-16 | 2009-12-24 | Mitsubishi Rayon Co Ltd | 光拡散フィルムおよびプリズムシート |
JP2009300869A (ja) * | 2008-06-16 | 2009-12-24 | Mitsubishi Rayon Co Ltd | 光拡散フィルムおよびプリズムシート |
JP2011028033A (ja) * | 2009-07-27 | 2011-02-10 | Sumitomo Chemical Co Ltd | 光制御板、面光源装置及び透過型画像表示装置 |
US8896925B2 (en) | 2011-03-15 | 2014-11-25 | Lg Chem, Ltd. | Micro-lens array sheet and backlight unit comprising the same |
TWI484260B (zh) * | 2011-03-15 | 2015-05-11 | Lg Chemical Ltd | 微透鏡陣列板及包含其之背光單元 |
JPWO2016194990A1 (ja) * | 2015-06-04 | 2018-03-22 | 三菱瓦斯化学株式会社 | ポリマーフィルム及びそれを用いたディスプレイ用光拡散フィルム |
JP7082488B2 (ja) | 2015-06-04 | 2022-06-08 | 三菱瓦斯化学株式会社 | ポリマーフィルム及びそれを用いたディスプレイ用光拡散フィルム |
WO2022138725A1 (ja) * | 2020-12-23 | 2022-06-30 | 京セラ株式会社 | 拡散板、発光デバイス及びセンサモジュール |
JP7483948B2 (ja) | 2020-12-23 | 2024-05-15 | 京セラ株式会社 | 拡散板、発光デバイス及びセンサモジュール |
Also Published As
Publication number | Publication date |
---|---|
JPWO2006036032A1 (ja) | 2008-05-15 |
KR20070061478A (ko) | 2007-06-13 |
EP1795923A4 (en) | 2010-10-06 |
TW200632466A (en) | 2006-09-16 |
KR101090387B1 (ko) | 2011-12-07 |
US20070242478A1 (en) | 2007-10-18 |
EP1795923A1 (en) | 2007-06-13 |
CN1947034B (zh) | 2010-09-01 |
CN1947034A (zh) | 2007-04-11 |
TWI329766B (ja) | 2010-09-01 |
JP5272309B2 (ja) | 2013-08-28 |
US7695167B2 (en) | 2010-04-13 |
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