WO2005026612A1 - 面光源装置及びそれに用いる導光体及びその製造方法 - Google Patents
面光源装置及びそれに用いる導光体及びその製造方法 Download PDFInfo
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- WO2005026612A1 WO2005026612A1 PCT/JP2004/013099 JP2004013099W WO2005026612A1 WO 2005026612 A1 WO2005026612 A1 WO 2005026612A1 JP 2004013099 W JP2004013099 W JP 2004013099W WO 2005026612 A1 WO2005026612 A1 WO 2005026612A1
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- Prior art keywords
- light
- incident end
- light guide
- light source
- face
- Prior art date
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Classifications
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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
-
- 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
-
- 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
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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
Definitions
- the present invention relates to an edge light type surface light source device and a light guide used therein, and more particularly, to a light guide along a light incident end face near a light guide light incident end face facing a primary light source.
- TECHNICAL FIELD The present invention relates to a surface light source device intended to reduce unevenness of luminance distribution observed as a bright line and a Z or a dark line, and particularly to a light guide used therefor and a method of manufacturing the same.
- the surface light source device of the present invention is suitably applied to, for example, a backlight of a liquid crystal display device.
- the liquid crystal display device basically includes a backlight portion, a liquid crystal display element portion, and a power.
- a knock light portion an edge light type is often used from the viewpoint of compactness of a liquid crystal display device.
- an edge-light type backlight at least one end face of a rectangular plate-shaped light guide is used as a light incident end face, and a linear or rod-shaped light source such as a straight tube fluorescent lamp is formed along the light incident end face.
- a primary light source is disposed, light emitted from the primary light source is introduced from the light incident end face of the light guide into the light guide, and a light emission surface that is one of two main surfaces of the light guide is provided.
- the light emitted from the light source is widely used.
- Patent Document 1 Japanese Utility Model Publication No. 40-26083
- Patent Document 2 Japanese Utility Model Application Laid-Open No. 60-60788
- Patent Document 3 Japanese Utility Model Application Japanese Patent Application Laid-Open No. 62-154422
- Patent Document 3 discloses that a light absorbing surface is located at a position close to a primary light source on a light emitting surface of a light guide. It is disclosed to dispose a film having an absorptivity or a light adjusting film for suppressing light transmission.
- This method simply deals with the fact that the intensity of the light emitted from the light guide light emitting surface in the region near the primary light source is greater than the intensity of the light emitted from the primary light source and the region. This is intended to limit the light emission of the light emitting surface area force having a small distance from the light emitting surface.
- Patent Document 4 discloses a light exit surface of a light entrance end face of a light guide and a light exit surface thereof. It has been proposed to attach a light-blocking member such as ink to an edge that forms a boundary with the opposite surface.
- Patent Document 5 discloses a technique for preventing the occurrence of such a dark line, in which a light absorption pattern in which the light absorption rate gradually decreases as the distance from the light incident end face increases. It is disclosed that a light absorbing layer having the same is formed.
- Patent Document 1 Japanese Patent Publication No. 40-26083
- Patent Document 2 Japanese Utility Model Publication No. 60-60788
- Patent Document 3 Japanese Utility Model Publication No. Sho 62-154422
- Patent document 4 JP-A-9-197404
- Patent Document 5 JP-A-8-227074
- Patent Document 4 attaches a light-blocking member to the edge of the light guide light incident end face, and a part of the light-blocking member also exerts force on the light incident end face. Part of the light incident from the end face is blocked, and the amount of light incident on the light guide from the primary light source is reduced by that amount, so that the overall brightness is easily reduced and the light incident from near the edge is reduced. Without the light-blocking member, the light to be guided is also blocked, so that a dark line is likely to occur in the display area.
- this method forms a light-shielding member having a very small width, the effect of suppressing the generation of bright lines is not sufficient.
- this method is very difficult in practice to provide a light-shielding member to an edge, and it is difficult to form a light-shielding member at a desired position, and it is difficult to form a light-shielding member attached to an edge. There is a problem that the conductive member is easily dropped.
- a light source that guides light emitted from the primary light source, and has a light incident end surface on which light emitted from the primary light source is incident and a light exit surface from which the guided light exits;
- a light absorption band having a width of 50 ⁇ m to 1000 ⁇ m extending along the light incident end face is formed on the light incident end face, and a side edge of the light absorption band near the light incident end face has a distance equal to the light incident end face force.
- a light guide for a surface light source device which is not more than 300 ⁇ m.
- the light absorption band is formed such that a visible light transmittance is higher at a side edge farther than a side edge near the light incident end face.
- the visible light transmittance of the light absorption band changes in at least two steps from a side edge near the light incident end face to a side edge far from the light incident end face.
- the visible light transmittance of the light absorption band changes continuously at least in part from the near edge to the far edge of the light incident end face.
- the lowest visible light transmittance of the light absorption band is in the range of 0% to 60%, and the highest value is in the range of 40% to 90%.
- the light absorption band is made of a black coating material.
- the black coating material is one of evaporative drying ink, thermosetting ink, and ultraviolet curable ink.
- the light absorption band contains light diffusing or light absorbing fine particles.
- fine irregularities are formed on the surface of the light absorption band.
- the projections of the fine irregularities on the surface of the light absorption band are formed by light diffusing or light absorbing fine particles contained in the light absorption band.
- an edge portion forming a boundary between the light emitting surface and the light incident end surface has a radius of curvature of 50 m or less.
- an edge portion forming a boundary between the light emitting surface and the light incident end surface is formed along the light incident end surface as a protrusion protruding from another region of the light emitting surface.
- the protrusion has a height of 50 m from the light exit surface, and Z or the protrusion has a full width at half maximum height of 50 m.
- a side edge of the light absorption band near the light incident end face has a distance of 0 m from the light incident end face.
- the width of the light absorption band is 0.4 times or less the thickness of the light guide at the position of the light incident end face.
- the light incident end face is configured such that the light emitted from the primary light source enters the boundary with the light emitting face.
- the light guide has a light emission mechanism formed on the light emission surface and the back surface on the Z side or on the opposite side.
- the light emitting mechanism has a rough surface force.
- the light emitting mechanism is formed on the light emitting surface, and a plurality of parallel prism arrays extending in a direction substantially perpendicular to the light incident end surface and formed on the rear surface are formed. Being done.
- the prism array has an apex angle of 85 ° to 110 °.
- the light incident end face is roughened. According to the present invention,
- a light absorption band corresponding portion is formed at least in a region close to the light incident end surface corresponding portion of the light emitting surface corresponding portion of the light guide material, and after being pressed, the light incident end surface corresponding portion is subjected to a cutting process to perform the light incidence.
- a side edge of the light absorption band corresponding portion near the light incident end surface corresponding portion is also cut and removed at the same time.
- the light absorption band corresponding portion is formed by applying ink.
- the light absorption band corresponding portion is formed by inkjet printing, screen printing, tambo printing, or heat transfer printing.
- ink dots that are independent or partially continuous with each other are formed at least in a region near the light incident end face of the light emitting surface of the light guide, and then the ink dots are formed.
- Forming a light-absorbing band by bonding adjacent ones of the above to form a continuous ink layer over the entire area, and then hardening the ink layer after pressing.
- the connection state of the ink dots in the ink layer is controlled by the leveling time.
- the surface state of the light absorption band is controlled by controlling the bonding state of the ink dots.
- the ink is a black ultraviolet curable ink, and ultraviolet light is applied to cure the ink layer.
- the light incident end face is formed by cutting a portion corresponding to the light incident end face of the light guide material, and then the light absorption band is formed.
- the position of a side edge near the light incident end face of the region is such that the ink layer reaches a protrusion formed by projecting toward the light emitting surface by the cutting process.
- the ink is an ultraviolet curable ink containing a (meth) acrylate monomer and Z or an organic solvent.
- the (meth) acrylate ester and Z or the organic solvent have a number average molecular weight of 100 or more.
- the (meth) acrylate ester is methyl methacrylate and / or the ink contains 0.5 to 10% by weight.
- the organic solvent has a boiling point of 60 ° C. or higher, and at least one of Z or methylethyl ketone, ethyl acetate, ethylform, cellosolve acetate, and methacrylic acid Comprising.
- the light guide for a surface light source device as described above the primary light source disposed adjacent to the light incident end face of the light guide, and the light disposed adjacent to the light exit surface of the light guide.
- a light-deflecting element, the light-deflecting element having a light-entering surface located opposite to a light-emitting surface of the light guide and a light-emitting surface opposite to the light-emitting surface.
- a surface light source device comprising: a plurality of prism arrays that extend in a direction substantially parallel to a light incident end surface of the light guide and are parallel to each other on a light incident surface.
- each of the plurality of prism rows on the light incident surface of the light deflecting element has two prism surfaces, and one of the prism surfaces is incident. The light is totally reflected by the other of the prism surfaces.
- a light diffusing element is arranged adjacent to the light exit surface of the light deflecting element, and the light diffusing element has a light incident end face force of the light guide of at least 2 mm and a positional force of 4 mm.
- a dot pattern part with a light-absorbing dot pattern formed in an area having a width up to and including the position is provided with a dot-shaped light-absorbing coating material having a diameter of 30 ⁇ m to 70 ⁇ m dispersed. It becomes.
- the dot pattern portion of the light diffusion element has a visible light transmittance of 60% to 95%.
- a narrow, specific width light absorption band extending along the light incident end face is formed on the light exit face of the light guide at a position close to the light incident end face.
- the light absorption band is formed only on the light exit surface of the light guide, its creation is easy, and the formed light absorption band does not fall off easily. It is possible to exhibit the above-mentioned effect of preventing the generation of bright lines satisfactorily over a long period.
- the light incident end surface corresponding portion is subjected to cutting to form the light incident end surface, so that the light absorbing band is formed.
- the distance from the light incident end face on the near side edge to the light incident end face can be easily set to 0 ⁇ m.
- ink dots are formed on the light emitting surface of the light guide by an ink-jet method, and then the ink dots are leveled to artificially increase the size of the ink dots.
- the ink-uncoated portion is filled with ink to form a continuous ink layer, and then the ink layer is hardened to form a light absorption band, so the required leveling time is set according to the viscosity of the ink. By doing so, it is possible to control the bonding state of the ink dots in the ink layer and easily control the surface state of the light absorption band.
- FIG. 1 is a schematic perspective view showing one embodiment of the surface light source device according to the present invention.
- the surface light source device of the present embodiment has a light guide 3 in which at least one side end surface is a light incident end surface 31 and one surface substantially orthogonal to this is a light exit surface 33.
- a linear primary light source 1 disposed opposite the light incident end face 31 of the light guide 3 and covered with the light source reflector 2; and a light deflecting element disposed on the light exit surface of the light guide 3. 4, a light diffusing element 6 disposed on the light exit surface 42 of the light deflecting element 4 so as to face the same, and a light diffusing element 6 disposed opposite to the light exit surface 33 of the light guide 3 on the opposite side.
- a light reflection element 5 disposed opposite the light incident end face 31 of the light guide 3 and covered with the light source reflector 2; and a light deflecting element disposed on the light exit surface of the light guide 3. 4, a light diffusing element 6 disposed on the light exit surface 42 of the light deflecting element 4 so as to face the same, and a light diffusing element 6 disposed opposite to the
- the light guide 3 is arranged parallel to the XY plane, and has a rectangular plate shape as a whole.
- the light guide 3 has four side end faces, and at least one of the pair of side end faces parallel to the YZ plane is a light incident end face 31.
- the light incident end face 31 faces the primary light source 1
- the light emitted from the primary light source 1 enters the light guide 3 from the light incident end face 31.
- the light source may be disposed so as to face another side end face such as the side end face 32 opposite to the light incident end face 31.
- the two main surfaces of the light guide 3 that are substantially perpendicular to the light incident end surface 31 are respectively positioned substantially parallel to the XY plane, and one of the surfaces (the upper surface in the figure) is the light exit surface 33.
- At least one of the light emitting surface 33 and the rear surface 34 has a directional light emitting mechanism that also has a rough surface force, and a number of lens arrays such as a prism array, a lenticular lens array, and a V-shaped groove.
- Directional light is emitted in a plane (XZ plane) orthogonal to the end face 31 and the light emitting face 33.
- the angle formed by the direction of the peak (peak light) of the luminous intensity distribution in the XZ plane and the light exit surface 33 is ⁇ .
- the angle ⁇ is, for example, 10 to 40 degrees, and the full width at half maximum of the emitted light luminous intensity distribution is, for example, 10 to 40 degrees.
- the rough surface and the lens array formed on the surface of the light guide 3 should have an average inclination angle ⁇ a of 0.5 to 15 degrees according to IS04287Z1-1984. It is also preferable to use a point force for achieving the uniformity of luminance at the same time.
- the average inclination angle ⁇ a is more preferably in the range of 11 to 12 degrees, and more preferably in the range of 1.5 to 11 degrees.
- the average inclination angle ⁇ a is preferably set to an optimum range by the ratio (LZt) of the thickness (t) of the light guide 3 to the length (L) in the direction in which the incident light propagates.
- the average inclination angle ⁇ a is preferably set to 0.5 to 7.5 degrees, more preferably, to 115 degrees. Range, more preferably 1.5-4 degrees.
- the average inclination angle ⁇ a is preferably 7 to 12 degrees, and more preferably 8 to 11 degrees.
- the average inclination angle ⁇ a of the rough surface formed on the light guide 3 is determined by measuring the rough surface shape using a stylus type surface roughness meter according to IS04287Z1-1984, and setting the coordinates in the measurement direction as X. From the obtained gradient function f (X), the following equations (1) and (2)
- ⁇ a tan _1 (A a) (2)
- L is the measured length
- ⁇ a is the tangent of the average tilt angle ⁇ a.
- the light guide 3 preferably has a light emission rate in the range of 0.5 to 5%, more preferably in the range of 13 to 13%. This is because when the light emission rate is less than 0.5%, the amount of light emitted from the light guide 3 tends to be small and sufficient luminance cannot be obtained, and when the light emission rate is more than 5%, the vicinity of the primary light source 1 is high. This causes a large amount of light to be emitted, and the emission light in the X direction on the light emission surface 33 is significantly attenuated, and the uniformity of luminance on the light emission surface 33 tends to be reduced.
- the angle of the peak light in the luminous intensity distribution (in the XZ plane) of the light emitted from the light emission surface is reduced.
- the full width at half maximum of the luminous intensity distribution (in the XZ plane) on the XZ plane which is in the range of 50 to 80 degrees to the surface normal and perpendicular to both the light incident end face and the light exit plane, is 10 to 40 degrees.
- a surface light source device having a high luminance can emit light having such a high directivity from the light guide 3, and can efficiently deflect the emission direction by the light deflecting element 4. Can be provided.
- the light emission rate from the light guide 3 is defined as follows.
- the constant ⁇ is the light emission rate
- the light emission rate ⁇ can be obtained from the gradient by plotting the logarithm of the light intensity of the light emitted from the light emission surface 23 on the vertical axis and (LZt) on the horizontal axis, and plotting these relationships. it can.
- the other main surface not provided with the directional light emitting mechanism is provided for controlling the directivity in a plane (YZ plane) parallel to the primary light source 1 of the light emitted from the light guide 3.
- a lens surface in which a large number of lens arrays extending in a direction (X direction) substantially perpendicular to the light incident end face 31 are arranged.
- a rough surface is formed on the light exit surface 33
- a lens surface is formed which has an array of a large number of lens arrays extending in a direction substantially perpendicular to the light incident end surface 31 (X direction).
- a lens surface may be formed on the light emitting surface 33 and the back surface 34 may be roughened.
- the lens array when a lens array is formed on the back surface 34 or the light exit surface 33 of the light guide 3, the lens array includes a prism array extending substantially in the X direction, a lenticular lens array, Although a groove in the shape of a letter or the like can be mentioned, it is preferable to form a prism array having a substantially triangular YZ section.
- the apex angle be in the range of 85 to 110 degrees. This is because by setting the apex angle in this range, the light emitted from the light guide 3 can be appropriately collected, and the luminance of the surface light source device can be improved. Preferably, it should be within the range of 90-100 degrees.
- a desired prism row shape is accurately produced, stable optical performance is obtained, and abrasion and deformation of the prism top during assembly work or when used as a light source device are prevented.
- a flat portion or a curved portion may be formed at the top of the prism array.
- light diffusing fine particles are mixed and dispersed inside the light guide. By doing so, a directional light emitting mechanism may be provided.
- the light incident end face 31 is preferably roughened in order to adjust the spread of light in the XY plane and the Z or XZ plane.
- the method of forming a rough surface include a method of cutting with a milling tool or the like, a method of polishing with ganite, sandpaper, puff, or the like, a method of blasting, electric discharge machining, electrolytic polishing, chemical polishing, or the like.
- blast particles used for blasting include spherical particles such as glass beads and polygonal particles such as alumina beads. The use of polygonal particles has the effect of spreading light. This is preferable because a large rough surface can be formed.
- an anisotropic rough surface can also be formed.
- the processing direction in the Z direction can be adopted to form streaky irregularities in the Z direction.
- the processing direction in the Y direction can be adopted to form a streaky uneven shape in the Y direction.
- the degree of surface roughening of the light incident end face 31 is such that the average inclination angle ⁇ a is 115 degrees in the thickness direction of the light guide, the center line average roughness Ra is 0.05-0.5 m,
- the ten-point average roughness Rz is preferably 0.5 to 3 m. This is because by setting the degree of surface roughening of the light incident end face 31 within this range, it is possible to suppress the occurrence of a bright band or a dark band, and it is possible to make bright lines and dark lines less visible.
- the average inclination angle ⁇ a is more preferably in the range of 2 to 4.5 degrees, and particularly preferably in the range of 2.5 to 3 degrees.
- the center line average roughness Ra is more preferably in the range of 0.7-0.3 m, particularly preferably in the range of 0.1-0.25 m.
- the ten-point average roughness Rz is more preferably in the range of 0.7-2.5 m, particularly preferably in the range of 1-2 ⁇ m.
- the degree of surface roughening of the light incident end face 31 is, in the longitudinal direction, for the same reason as described above, the average inclination angle ⁇ a is 113 degrees and the center line average roughness Ra is 0.02-0. It is preferable that Lm and ten-point average roughness Rz are 0.3 to 2 m.
- the average inclination angle ⁇ a is more preferably 1.3 to 2.7 degrees, and particularly preferably 1.5 to 2.5 degrees.
- the center line average roughness Ra is more preferably in the range of 0.03-0.08 m, particularly preferably in the range of 0.05-0.
- the ten-point average roughness Rz is more preferably in the range of 0.4-1.7111 and particularly preferably in the range of 0.5-1.5 / zm.
- a light absorption band 36 extending along the light incident end surface 31 is formed on the light exit surface 33 of the light guide.
- the light absorption band 36 can be formed, for example, by applying a black coating material.
- the formation of the light absorption band 36 is not particularly limited, but can be performed by, for example, coating with ink, and is particularly preferably performed by inkjet printing, screen printing, tambo printing, or thermal transfer printing.
- the material of the light absorption band 36 it is preferable to use a quick-drying material from the viewpoint of productivity, and the drying time is preferably 60 seconds or less, more preferably 40 seconds or less, and still more preferably 20 seconds or less. Less than a second.
- a light absorption band material for example, an organic solvent such as ethyl methyl ketone, an organic solvent-based paint using (meth) acrylate ester monomer, or the like, an evaporative drying ink, a thermosetting ink, or an ultraviolet ray Curable paints and ultraviolet curable inks are exemplified.
- This light absorption band is By absorbing at least a part of the light directly arriving in the light guide 3 from the light guide 31, the generation of a bright line near the light incident end face 31 is prevented.
- the visible light transmittance JIS-K7105B
- JIS-K7105B is, for example, 0 to 90%, preferably 0 to 60%, more preferably 2 to 45%, and particularly preferably 4 to 30%.
- the light absorption band 36 preferably has a reflectance (JIS-K7105B) of 0-20%, more preferably 0-15%.
- JIS-K7105B a reflectance of 0-20%, more preferably 0-15%.
- FIG. 2 is a schematic plan view showing the light guide 3 together with the primary light source 1.
- the light absorption band 36 does not block the light incident from the light incident end face 31, but lowers the luminance due to the decrease in the amount of incident light and dark lines due to blocking the light to be guided.
- the light guide 3 it is necessary that the light guide 3 be formed only on the light exit surface 33 and not formed on the light incident end surface 31.
- the light absorption band 36 has a width (dimension in the X direction) W, and is closer to the light incident end face 31 of the two side edges that define the width, and between the side edge and the light incident end face 31. The distance is D.
- the width W is between 50 and 1000 ⁇ m, preferably between 100 and 700 ⁇ m, particularly preferably between 200 and 400 ⁇ m. If the width W is less than 50 ⁇ m, the required effect of preventing the generation of bright lines tends to decrease. If the width W exceeds 1000 m, dark lines tend to occur and the overall brightness tends to decrease.
- the width W is preferably not more than 0.4 times, more preferably not more than 0.3 times, particularly preferably not more than 0.2 times, the thickness of the light guide 3 at the light incident end face position. It is. Further, if the distance D is 300 m or less, the above-described effect of preventing the occurrence of bright lines can be obtained, preferably 200 ⁇ m or less, particularly preferably 100 ⁇ m or less.
- a concave portion is formed in at least a part of the light absorption band forming portion of the light exit surface 33, and a paint or the like is applied to the concave portion.
- a concave portion 70 having a triangular cross section or a lenticular shape is formed on the light emitting surface 33, for example, a depth of 150 m or less, preferably 100 m or less, and more preferably 50 m or less.
- the light absorption band 36 is formed so as to include the inside of the concave portion.
- the light guide 3 is not limited to the shape as shown in FIG. 1, but may have various shapes such as a wedge-shaped light incident end face.
- FIG. 3 is a schematic plan view showing a light guide material 3 ′ obtained by applying a coating material to be a light absorption band formed by resin molding.
- a light incident end surface corresponding portion 31 ′ when portions corresponding to the respective portions of the finally obtained light guide 3 are indicated as corresponding portions, a light incident end surface corresponding portion 31 ′, a light output surface corresponding portion 33 ′, and a light absorption band It has a corresponding part 36 '.
- a mat surface as a rough surface constituting a required light emitting mechanism is formed in the light emitting surface corresponding portion 33 ', and a required prism array is formed in the opposite back surface corresponding portion.
- a light absorption band corresponding portion 36 ' is formed in a region near the light incident end surface corresponding portion 31' of the light emitting surface corresponding portion 33 '.
- the light incident end face 31 is formed as a cut surface by cutting the unnecessary part corresponding to the light incident end face 31 ′ and cutting off unnecessary portions.
- the light emitted from the primary light source 1 can easily enter the light incident end face 31 up to the boundary with the light exit face 33.
- a light absorption band corresponding portion 31 ′ is formed at an unnecessary portion to be cut off by cutting, and the light of the light absorption band corresponding portion 31 ′ is formed in the cutting process.
- the above-mentioned distance D is easily set to 0 m, and the primary light source 1 is moved until the light incident end face 31 reaches the boundary with the light emitting face 33. It can be configured so that light emitted from the light enters.
- the light deflecting element 4 is arranged on the light exit surface 33 of the light guide 3.
- the two main surfaces 41 and 42 of the light deflecting element 4 are arranged as a whole in parallel with each other, and are respectively positioned as a whole in parallel with the XY plane.
- One of the principal surfaces 41 and 42 (the principal surface located on the light exit surface 33 side of the light guide 3) is a light entrance surface 41, and the other is a light exit surface 42.
- the light exit surface 42 is a flat surface parallel to the light exit surface 33 of the light guide 3.
- the light incident surface 41 is a prism array forming surface on which a number of prism arrays extending in the Y direction are arranged in parallel with each other.
- the prism array formation surface may have a relatively narrow flat portion between adjacent prism arrays (for example, a flat portion having a width approximately equal to or smaller than the X dimension of the prism array).
- a relatively narrow flat portion between adjacent prism arrays for example, a flat portion having a width approximately equal to or smaller than the X dimension of the prism array.
- prism rows are continuously arranged in the X direction without providing a flat part It is preferable to do.
- FIG. 5 shows how light is deflected by the light deflector 4.
- This figure shows the traveling direction of the peak light of the light guide 3 (light corresponding to the peak of the emitted light distribution) in the XZ plane.
- the peak light emitted obliquely at an angle ⁇ from the light exit surface 33 of the light guide 3 enters the first surface of the prism array, is totally reflected by the second surface, and exits almost in the direction normal to the light exit surface 42. I do.
- the luminance in the direction of the normal to the light exit surface 42 can be sufficiently improved in a wide area by the action of the prism array of the light guide rear surface 34 as described above.
- the shape of the prism surface of the prism array of the light deflecting element 4 is not limited to a single plane, but may be, for example, a convex polygonal cross section or a convex curved surface shape.
- a dagger can be planned.
- a desired prism shape is accurately produced, stable optical performance is obtained, and abrasion and deformation of the prism top during assembly work or when used as a light source device are suppressed.
- a flat portion or a curved portion may be formed at the top of the prism array.
- the width of the flat portion or the curved surface portion formed at the top of the prism row should be 3 m or less. From the viewpoint of reducing the luminance of the light source device, it is preferable from the viewpoint of suppressing the generation of a non-uniform luminance pattern due to the sticking phenomenon. It is more preferably 2 m or less, and even more preferably 1 ⁇ m or less.
- the light diffusing element 6 is arranged adjacent to the light exit surface of the light deflecting element 4 in order to appropriately control the viewing range that does not cause a reduction in luminance as much as possible according to the purpose. Can be. Further, in the present invention, by arranging the light diffusing element 6 in this way, it is possible to suppress glare, uneven brightness, and the like that cause deterioration in quality and improve quality.
- the light diffusing element 6 preferably has an uneven surface on the incident surface 61 facing the light deflecting element 4 in order to prevent stuck with the light deflecting element 4.
- the emission surface 62 of the light diffusion element 6 is also provided with a concavo-convex structure on the emission side surface of the light diffusion element 6 in consideration of the standing with the liquid crystal display element disposed thereon. Is preferred.
- the average inclination angle is 0.7 degree or more, more preferably 1 degree or more, and more preferably 1 degree or more. Is greater than 1.5 degrees.
- the light diffusing property of the light diffusing element 6 is such that a light diffusing agent, for example, a homopolymer or copolymer such as silicone beads, polystyrene, polymethyl methacrylate, or fluorine methacrylate is added to the light diffusing element 6. It can be provided by mixing a polymer or the like or by providing an uneven structure on at least one surface of the light diffusion element 6. The degree of the concavo-convex structure formed on the surface differs between the case where it is formed on one surface of the light diffusing element 6 and the case where it is formed on both surfaces.
- a light diffusing agent for example, a homopolymer or copolymer such as silicone beads, polystyrene, polymethyl methacrylate, or fluorine methacrylate.
- the average inclination angle is preferably in the range of 0.8 to 12 degrees, more preferably 3.5 to 7 degrees, More preferably, it is 4-16.5 degrees.
- the average inclination angle of the uneven structure formed on one surface is in the range of 0.8 to 6 degrees, more preferably 2 degrees. — 4 degrees, more preferably 2.5—4 degrees.
- the average inclination angle on the incident surface side of the light diffusion element 6 be larger than the average inclination angle on the emission surface side.
- the haze value of the light diffusing element 6 is preferably in the range of 8 to 82%, more preferably in the range of 30 to 70% because the viewpoint of improving the luminance characteristics and improving the visibility is preferable. , More preferably in the range of 40-65%.
- FIG. 6 is a schematic plan view showing the light diffusion element 6 together with the primary light source 1.
- the light diffusing element 6 has a dot pattern portion 64 formed thereon.
- the dot pattern portion is formed by dispersing and dispersing a light absorbing coating material in the form of a dot having an emission surface of 62 mm and a diameter of 30 ⁇ m to 70 ⁇ m.
- the light incident end face force of the light guide is also a distance dl.
- Position force also exists in the area of width (d2-dl) including up to the position of distance d2.
- the distance dl is less than 2 mm and the distance d2 is more than 4 mm.
- the visible light transmittance of the dot pattern portion 64 is 60% to 95%.
- the density of the dispersed arrangement of the dot-shaped light-absorbing coating materials should be increased as the primary light source power increases in at least a part of the width region near the position of the distance d2 from the light incident end face. It is preferable to make it smaller gradually.
- the primary light source 1 is a linear light source extending in the Y direction. Light lamps and cold cathode tubes can be used. In this case, as shown in Fig. 1, the primary light source 1 should not only be installed facing one side end face of the light guide 3, but also installed on the opposite side end face if necessary. You can also.
- the primary light source 1 is not limited to a linear light source, but may be a point light source such as an LED light source, a halogen lamp, a metahalo lamp, or the like.
- a small point light source such as an LED.
- the primary light source 1 can be disposed at a corner of the light guide 3 or the like.
- the light incident on the light guide 3 propagates in the light guide radially around the primary light source 1 substantially in the same plane as the light exit surface.
- the outgoing light emitted from the light emitting surface of the light guide 3 is also emitted radially around the primary light source 1, the emitted light emitted radially can be efficiently regardless of the emitting direction.
- the prism array formed on the light deflecting element 4 is arranged in a substantially arc shape in parallel so as to surround the primary light source 1, and the point power of the luminance uniformity is also preferable.
- the light source reflector 2 guides the light of the primary light source 1 to the light guide 3 with little loss.
- a plastic film having a metal deposition reflective layer on the surface can be used.
- the light source reflector 2 avoids the light diffusing element 6 and the light deflecting element 4 and emits light from the light guide 3 from the outer surface of the edge of the light reflecting element 5 through the outer surface of the primary light source 1. It is wound around the edge of the surface.
- the light source reflector 2 can be wound around the light-emitting surface of the light deflector 4 through the outer surface of the primary light source 1 from the outer surface of the edge of the light reflector 5, avoiding only the light-diffusing element 6.
- the outer surface force of the edge of the light reflecting element 5 can be wound around the emitting surface edge of the light diffusing element 6 via the outer surface of the primary light source 1.
- a reflecting member similar to the light source reflector 2 can be attached to a side end surface other than the side end surface 31 of the light guide 3.
- the light reflecting element 5 for example, a plastic sheet having a metal deposited reflective layer on the surface can be used.
- the light reflecting element 5 instead of the reflection sheet, a light reflection layer or the like formed on the back surface 34 of the light guide 3 by metal evaporation or the like can be used.
- the light guide 3, the light deflecting element 4, and the light diffusing element 6 of the present invention can be made of synthetic resin having high light transmittance.
- a synthetic resin include metharyl resin, acrylic resin, polycarbonate resin, polyester resin, and Shiridani vinyl resin.
- metharyl resin is optimal because of its high light transmittance, heat resistance, mechanical properties, and moldability.
- methacrylic resin is a resin containing methyl methacrylate as a main component, and preferably contains 80% by weight or more of methyl methacrylate.
- a transparent synthetic resin plate is formed with a desired surface structure. It may be formed by hot pressing using a mold member provided, or may be formed simultaneously with molding by screen printing, extrusion molding, injection molding, or the like. Further, the structural surface can be formed by using heat or photo-curable resin.
- a transparent base material such as a transparent film or sheet, which also has high strength, such as a polyester resin, an acrylic resin, a polycarbonate resin, a salted vinyl resin, and a polymethacrylimide resin
- a rough surface structure made of active energy ray-curable resin or a lens array structure may be formed, or such a sheet is bonded and fused onto a separate transparent substrate by a method such as adhesion or fusion. You may.
- the active energy ray-curable resin polyfunctional (meth) acrylic compounds, vinyl compounds, (meth) acrylates, arylyl conjugates, metal salts of (meth) acrylic acid and the like can be used.
- a dot-shaped light-absorbing coating material of a dispersed arrangement constituting the dot pattern portion of the light diffusing element 6 is indicated by reference numeral 64 '.
- the liquid crystal display device is observed by an observer through the upward force liquid crystal display element LC in FIG.
- FIG. 7 shows a case where the distance D is 0 ⁇ m in the light guide 3.
- the light absorption band 36 extends to the boundary with the light incident end face 31, but the light It does not extend above the firing surface 31. That is, the light incident end face 31 is configured such that the light emitted from the primary light source 1 is incident up to the boundary with the light emitting face 33.
- the light introduced into the light guide 3 from the light incident end face 31 most of the light L1 that directly reaches the light absorption band 36 is absorbed by the light absorption band. The remainder is reflected by the light exit surface 33 and becomes light L2 traveling in the light guide.
- the light L2 is sufficiently weakened compared to the light L1 by light absorption in the light absorption band 36, and therefore does not cause emission lines. Assuming that the light absorption band 36 does not exist, the intensity of the light L2 is considerably high.
- the light L2, that is, the reflected light at the portion provided with the light absorption band 36 in the present invention is the largest cause of the generation of the bright line, and when the light absorption band 36 does not exist, a prominent bright line is generated.
- a part of the light emitted from the primary light source 1 is reflected by the light source reflector 22 and reaches the light absorption band 36 without reaching the light incident end face 31, where most of the light is absorbed.
- the light enters the light guide from the light emitting end face 33 of the portion provided with the light absorption band 36 in the present invention. This light is also a cause of the above-mentioned bright line, and in this case, if the light absorption band 36 does not exist, a bright line is generated.
- the liquid crystal display element LC since light of a sufficiently collimated narrow! And brightness distribution (in the XZ plane) can also be made incident on the liquid crystal display element LC, the light in the liquid crystal display element can be reduced. An image display with good brightness and hue uniformity without gradation inversion can be obtained, and light irradiation concentrated in a desired direction can be obtained. The efficiency of using the amount of light emitted by the primary light source 1 for illumination in this direction Can be increased.
- the light absorption band 36 has been described as having a substantially uniform light absorption characteristic in the width direction.
- the light absorption band of the light absorption band changes in the width direction. May be.
- a light absorption band 36 is formed so as to be closer to the light incident end face, farther than the side edge, and have a higher visible light transmittance at the side edge.
- the light absorption band 36 is formed from a first region 36-1 near the light incident end face and a second region 36-2 far from the light incident end face in the width direction (X direction).
- the visible light transmittance T2 of the second region 36-2 is reduced to the first region 36-2.
- Such a light absorption band 36 in which the visible light transmittance changes in two steps is obtained by first applying a coating material to both the first region 36-1 and the second region 36-2 to a uniform thickness. It can be obtained by applying an additional coating material only in the first region 36-1 after pressing.
- a light absorption band in which the visible light transmittance changes in three or more stages can be formed.
- the thickness of the light absorption band 36 is gradually reduced from the side edge near the light incident end face 31 to the side edge far from the light incident end face 31 in the width direction (X direction) of the light absorption band 36.
- the visible light transmittance of the light absorption band 36 may be changed continuously in the width direction of the light absorption band 36.
- the light absorption band 36 having such a configuration can be obtained by applying a coating material while moving the mask member in the X direction toward and away from the light incident end face 31 as well.
- the continuous change of the visible light transmittance in the light absorption band 36 does not need to be over the entire width direction but may be a part of the width direction.
- the change in the visible light transmittance in the light absorption band 36 may be a combination of the stepwise change described with reference to FIG. 10 and the continuous change described with reference to FIG.
- the visible light transmittance of the light absorption band 36 is preferably such that the lowest value is in the range of 0% to 60% and the highest value is in the range of 0% to 90%. By being within this range, it is possible to sufficiently prevent the occurrence of dark lines while maintaining the effect of preventing the generation of bright lines, and to further reduce the occurrence of uneven brightness.
- FIG. 12A, FIG. 12B, FIG. 13A, and FIG. 13B still another example of the method for manufacturing the above light guide will be described.
- 12A and 13A are partial plan views
- FIGS. 12B and 13B are XZ partial cross-sectional views.
- ink dots 36A independent or partially continuous with each other are formed by an inkjet method.
- the equipment used to carry out the inkjet method includes the continuous (continuous injection) method and the piezo-noz method. (DOD (drop-on-demand) type printer using a printer).
- nozzles eject ink, and, if necessary, scan the light guide 3 with respect to the nozzles in a required direction parallel to the light emitting surface 33, thereby forming a predetermined light emitting surface.
- a large number of independent ink dots 36A are formed as shown in the area. Adjacent ones of these ink dots are shown as shown, all of which are completely independent, but some of them are partially overlapped and continuous.
- adjacent ink dots are joined to form a continuous ink layer (hereinafter, referred to as “leveling”). This leveling is performed for the time required to obtain the required leveling amount (degree). As a result, as shown in FIGS. 13A and 13B, adjacent ink dots are connected to each other to form an ink layer 36B continuous over the entire area of the width D2 separated from the light incident end face 31 by a distance S. Eggplant The area having the width D2 includes all of the area having the width D1, and is slightly larger than the width D1 due to leveling.
- the light absorption band 36 is formed by curing the ink layer 36B.
- an ultraviolet curable ink for example, an ultraviolet curable ink is used.
- UV-curable inks are preferably used because a required leveling amount (degree) can be easily achieved by controlling the timing of UV irradiation. Further, in order to easily control the time for obtaining the required leveling amount, it is preferable to keep the temperature of the ink discharge nozzle, that is, the temperature of the ink constant. Also, by heating the light guide 3, the viscosity of the ink dots 36A after ink discharge such as ink drop can be reduced, thereby obtaining a required leveling amount. And the time required for printing can be shortened.
- the surface state of the light absorption band 36 that is, the degree of unevenness. it can.
- unnecessary light can be made less noticeable. That is, as described above, when part of the light emitted from the primary light source 1 is reflected by the light source reflector 22 and reaches the light absorption band 36 without reaching the light incident end face 31, most of the light is absorbed here. Is done. At this time, the remaining light is reflected toward the light guide light emitting surface 33, but this reflected light is spread by unevenness on the surface of the light absorption band 36. Diffuse reflection can make it inconspicuous.
- FIG. 14A With reference to FIG. 14A, FIG. 14B, FIG. 14C, and FIG. 14D, still another example of the above-described method for manufacturing a light guide will be described.
- a light guide material 3 ′ as shown in FIG. 14A is prepared.
- the light incident end face 31 is formed by cutting the light incident end face corresponding portion 31 ′.
- the boundary between the light incident end face 31 and the light emitting face 33 protrudes toward the light emitting face 33 (ie, protrudes and protrudes with respect to other areas of the light emitting face 33).
- Part 39 is formed.
- the protrusion 39 extends along a boundary between the light incident end face 31 and the light exit face 33, that is, along the light incident end face 31.
- the protruding portion 39 can be formed by cutting as described above, or may be formed by injection molding.
- ink dots 36A are formed in required areas on the light emitting surface 33.
- the formation of the ink dots is performed as described with reference to FIGS. 12A and 12B.
- leveling of the ink dots is performed to form an ink layer 36B in a required area of the light emitting surface 33, as shown in FIG. 14D.
- the formation of this ink layer is performed by the force applied as described above with reference to FIGS. 13A and 13B.
- the side edge of the ink layer 36B formed by leveling near the light incident end face 31 forms the protrusion 39.
- the position of the ink dot formation area is set so as to reach the position. That is, the area where the ink dot 36A shown in FIG. 14C is formed is slightly separated from the light incident end face 31. As a result, the ink flowing during the ink dot leveling is prevented from moving to the light incident end face 31 by the protrusion 39.
- the light absorption band 36 is formed by curing the ink layer 36B.
- the protrusion 39 is required. of The dimensions are preferably within the appropriate ranges as follows. That is, as shown in FIG. 18, the height of the protruding portion 39 (the height of the other area force of the light emitting surface 33) is H, and the full width at half maximum of the height of the protruding portion 39 in the XZ cross-sectional shape is shown in FIG.
- W is preferably 1 to 50 ⁇ m, more preferably 2 to 30 ⁇ m, even more preferably 5 to 20 ⁇ m, and W is preferably 1 to 50 ⁇ m, more preferably Is 2 to 30 ⁇ m, more preferably 5 to 20 ⁇ m. If the protrusion height H is too small, the effect of preventing ink movement tends to be insufficient. If the protrusion height H is too large, assembly of the surface light source device becomes difficult or chipping of the protrusion occurs. The ink tends to move to the vicinity of the top of the protrusion.
- the UV-curable ink which is a coating material for forming the light absorption band 36, contains (meth) acrylate monomer and Z or an organic solvent. It is preferable to use an ultraviolet curable ink. This is because it is advantageous in improving the bonding strength of the light absorption band 36 formed by curing the ink layer to the surface of the light guide 3.
- the presence of the organic solvent in the ink improves the anchor effect by melting and roughening the surface of the light guide 3.
- a (meth) acrylic resin is used as the light guide 3
- the presence of the (meth) acrylate monomer in the ink causes the ink to react with the ink during polymerization in the ink. A cross-linking reaction easily occurs with the light guide, thereby improving the anchor effect.
- the (meth) acrylate monomer and the organic solvent preferably have a number average molecular weight of 100 or more, preferably 150 or more, more preferably 200 or more so that the ink concentration does not significantly change.
- the (meth) acrylate ester is, for example, methyl methacrylate, and is preferably contained in the ink, for example, at 0.5 to 10% by weight.
- the organic solvent preferably has a boiling point of 60 ° C. or higher, preferably 80 ° C. or higher, more preferably 100 ° C.
- ink concentration does not significantly change
- methyl ethyl ketone Containing at least one of ethyl acetate, chloroform, cellosolve acetate and methacrylic acid Is exemplified.
- Examples of such an ultraviolet curable ink include those having the following composition.
- Oligomeric acrylic acid 30- 50 weight 0/0
- Isovol acrylate 10-20% by weight
- Isovol acrylate 10-20% by weight
- such an ultraviolet curable ink when the light absorption band is formed by an ink-jet method or the like, such an ultraviolet curable ink has an ink viscosity of 11 to 100 cp at the head temperature at the time of ink ejection, and has It is more preferable to use one having a tension of 20 to 55 mNZm, more preferably one having an ink viscosity of 1 to 50 cp and a surface tension of 20 to 45 mNZm, and more preferably one having an ink viscosity of 1 to 20 cp and a surface tension of 25. — 35mNZm.
- the head temperature is more preferably 10 to 100 ° C. from the viewpoints of the leveling properties of the ink dots, the adhesion to the light guide, and the accurate application position stability of the ejected ink. Is 35-85 ° C, more preferably in the range of 40-60 ° C.
- the head speed is determined from the viewpoints of shortening the tact time, leveling of the ink dots, and adhesion to the light guide. Is preferably set to 10-100 mmZ seconds, more preferably 200-800 mmZ seconds, and even more preferably in the range of 250-500 mmZ seconds.
- a material containing light diffusing or light absorbing fine particles can be used as the light absorbing band 36.
- the particle size of the fine particles is preferably 20 ⁇ m or less, more preferably 14 ⁇ m or less, and particularly preferably 8 ⁇ m or less.
- Such fine particles can be contained in an amount of 10 to 125% by weight based on 100 parts by weight of the solid content of the coating material excluding the fine particles.
- the light-absorbing fine particles include those which also have strong power, such as black resin-based fine particles such as acrylic resin, styrene resin, (meth) acrylic Z-styrene copolymerized resin and benzoguanamine resin containing carbon black.
- black resin-based fine particles such as acrylic resin, styrene resin, (meth) acrylic Z-styrene copolymerized resin and benzoguanamine resin containing carbon black.
- the light diffusing fine particles include polymer fine particles such as acrylic resin, styrene resin, (meth) acrylic Z-styrene copolymer resin and silicone resin, and inorganic fine particles such as silica, alumina and calcium carbonate. Those that can be powerful can be exemplified.
- the light diffusing fine particles may use light diffusion due to surface reflection, or may use light diffusion due to refraction of internally transmitted light having a light transmitting property.
- the light-absorbing fine particles contribute to the improvement of the light absorption of the light absorption band 36, and the light-diffusing fine particles indirectly improve the light absorption by diffusing the light in the light absorption band 36, and further absorb the light. It contributes to the averaging due to the diffusion of the emitted light without being diffused.
- FIG. 15 shows an embodiment of the light absorption band 36 containing light diffusing or light absorbing fine particles.
- fine irregularities are formed on the surface of the light absorption band 36.
- the convex portion 37 of the unevenness is formed by light diffusing or light absorbing fine particles 38 contained in the light absorbing band 36.
- the irregularities can be formed with the formation of the coating film by including the light diffusing or light absorbing fine particles 38 in the coating material constituting the light absorbing band 36.
- FIG. 16 is an enlarged view of a boundary between the light exit surface 33 and the light incident end surface 31 of the light guide 3.
- the edge forming the boundary between the light exit surface 33 and the light incident end surface 31 is ideally a substantially right angle.
- the force may be a curved surface with a small radius of curvature accompanying the force.
- the synthetic resin of the light guide material is partially melted by the processing, and the boundary between the light exit face 33 and the light incident end face 31 is formed. May be a curved surface based on the surface tension.
- the radius of curvature R of the edge portion is preferably 50 ⁇ m or less. This is because if the radius of curvature R of the edge portion is too large, the incidence of light from the edge portion becomes remarkable, and this portion acts like a convex lens, and extraordinary light is emitted from the light guide 3, This is because the effect of preventing the emission line from being generated by the light absorption band 36 may be reduced.
- the radius of curvature R of the edge portion is more preferably 10 m or less, and particularly preferably 5 ⁇ m ⁇ (below (3 ⁇ 4D.
- FIG. 17 shows the boundary between the light exit surface 33 and the light incident end surface 31 when the light incident end surface 31 and the side edge near the light incident end surface of the light absorption band 36 are simultaneously formed by cutting.
- the enlarged view of FIG. Due to the surface tension, a curved surface having a radius of curvature (corresponding to the above-mentioned projection 39) is formed at the edge portion of the boundary between the light exit surface 33 and the light incident end surface 31, and the edge of the light absorption band 36 becomes the light guide edge portion. It is positioned to expose a part of the minute. The exposed portion of the light guide edge portion constitutes a light incident end face 31.
- one surface is a matt surface
- the other surface is a prism apex angle of 100 degrees
- the apex tip radius of curvature is 15 ⁇ m.
- a rectangular and wedge-shaped light guide material which is a prism pattern in which prism rows with a pitch of 50 m and a pitch of 50 m are arranged in parallel so as to be parallel to the short sides, was produced.
- the longer side force of the thicker wall and various widths are printed by black screen printing.
- the ink was applied to form a light absorption band corresponding portion.
- the visible light transmittance of the ultraviolet-curable black ink was 40%. .
- Carbon black 5% by weight
- the light guide has a wedge plate shape of 230mm X 290mm, thickness of 2.2mm-0.7mm, the radius of curvature R of the edge part is 40 / xm, and the distance from the light incident surface is 0 ⁇ m
- the widths of the light absorption bands were as follows:
- Example 9-1 One 75 ⁇ m
- Comparative Example 3 20 ⁇ m (A light absorption band with a width of 20 ⁇ m is also continuously formed on the light incident end face side.)
- the cold-cathode tube is placed along the long side of the light guide along the long side so as to face one side end face (the end face with a thickness of 2.2mm) corresponding to the side (long side) of 290mm in length of the light guide. It was covered with a light source reflector (silver reflective film manufactured by Reiko Co.) and arranged. Further, a light diffuse reflection film (E60 [trade name], manufactured by Toray Industries, Inc.) is attached to the other side end surface, and the reflection sheet is opposed to the surface (rear surface) of the prism array. Was placed. The above configuration was incorporated in a frame. In this light guide, the maximum peak of the luminous intensity distribution (in the XZ plane) of the emitted light was 70 degrees with respect to the normal direction of the light emitting surface, and the full width at half maximum was 22.5 degrees.
- one prism surface has a convex curved shape with a radius of curvature of 1000 / zm, and the other prism surface has a planar shape.
- a prism sheet in which a number of prism rows of 50 ⁇ m arranged in parallel were formed on one surface of a polyester film having a thickness of 125 ⁇ m.
- the prism sheet thus obtained is oriented such that the prism row forming surface faces the light exit surface (mat surface) side of the light guide, and the ridge line of the prism row is parallel to the light incident end face of the light guide.
- Each of the prism rows was placed such that the plane-shaped prism faces faced toward the light incident end face.
- Example 119 and Comparative Example 113 obtained as described above, the primary light source was turned on under the same conditions, and the light emitting surface was visually observed.
- the bright line near the light guide light incident end face and the dark line in the display area were hardly conspicuous in the case of the ninth one, whereas the bright line near the light guide light incident end face in the comparative example 1 was hardly noticeable.
- Bright line was observed, and the brightness of the light in the vicinity of the light guide light incident end face was lower in the case of Comparative Example 2 than in Example 19; A decrease in luminance and a dark line in the display area were observed as compared with those in the case of 1-9.
- a light guide material was produced in the same manner as in Example 1. Then, the light guide material was cut into a portion corresponding to the light incident end surface to obtain a light guide having a light incident end surface formed as a cut surface.
- the light guide was 230 mm X 290 mm, 2.2 mm-0.7 mm thick wedge plate.
- a large number of the following ultraviolet-curable black inks were dropped on the mat surface of the light guide material on which the prism pattern was formed by the inkjet method under the following conditions, and the width D1 as shown in FIGS.
- a large number of independent ink dots with a diameter of about 100 m were formed in the area of 300 ⁇ m and a distance S ′ of about 60 ⁇ m.
- the ink dots were leveled for 5 seconds to form an ink layer that was continuous over the entire area with a width D2 of about 400 ⁇ m and a distance S of about 10 ⁇ m as shown in FIGS.13A and 13B. Formed. At that time, the ink layer is cured by irradiating ultraviolet rays to form a substantially linear light absorption band. Done.
- UV-curable black ink (95% by weight of ink + 5% by weight of methyl methacrylate): Ink composition:
- Oligomeric acrylic acid 42 wt 0/0
- Carbon black 5% by weight
- the visible light transmittance of the ultraviolet-curable black ink when printed on a transparent acrylic plate having a thickness of 2 mm to a size capable of measuring the visible light transmittance is as follows. 20%.
- the obtained light guide was combined with a cold cathode tube, a light source reflector, a light diffusion reflection film and a reflection sheet in the same manner as in Example 1, and the resulting structure was incorporated into a frame.
- the maximum peak of the emitted light luminous intensity distribution (in the XZ plane) was 70 degrees with respect to the normal direction of the light emitting surface, and the full width at half maximum was 22.5 degrees.
- the prism array forming surface faces the light exit surface (mat surface) side of the light guide, and the ridge of the prism array faces the light incident end surface of the light guide.
- the prisms were placed so that they were parallel and the flat prism faces of each prism row faced toward the light incident end face of the light guide.
- a light guide material similar to that of Example 1 was manufactured, and thereafter, a cutting process was performed on a light incident end surface corresponding portion of the light guide material to obtain a light guide having a light incident end surface formed as a cut surface.
- the light absorption band was not formed.
- the obtained light guide was combined with a cold cathode tube, a light source reflector, a light diffusion reflection film and a reflection sheet in the same manner as in Example 1, and the resulting structure was incorporated into a frame.
- the maximum peak of the emitted light luminous intensity distribution (in the XZ plane) was 70 degrees with respect to the normal direction of the light emitting surface, and the full width at half maximum was 22.5 degrees.
- the prism row forming surface faces the light exit surface (mat surface) side of the light guide, and the ridge line of the prism row faces the light incident end surface of the light guide.
- the prisms were placed so that they were parallel and the flat prism faces of each prism row faced toward the light incident end face of the light guide.
- the primary light source was turned on under the same conditions as in Example 10, and the light emitting surface was visually observed. A clear bright line was observed.
- a light guide material was produced in the same manner as in Example 1. Then, the light guide material was cut into a portion corresponding to the light incident end surface to obtain a light guide having a light incident end surface formed as a cut surface.
- the light guide was 230 mm X 290 mm, 2.2 mm-0.7 mm thick wedge plate.
- a lot of ultraviolet curable black ink was dropped on the mat surface of the light guide material on which the prism pattern was formed by the inkjet method in the same manner as in Example 10, and the width D1 as shown in FIG. 12A and FIG.
- a large number of ink dots with a diameter of about 100 m were formed in an area of about 60 ⁇ m with a distance S 'of about 60 ⁇ m.
- each ink dot was located independently of each other, the width was about 300 ⁇ m, and the distance between the light incident end face force was about 60 ⁇ m.
- the obtained light guide was combined with a cold cathode tube, a light source reflector, a light diffusion reflection film and a reflection sheet in the same manner as in Example 1, and the resulting structure was incorporated into a frame.
- the maximum peak of the emitted light luminous intensity distribution (in the XZ plane) was 70 degrees with respect to the normal direction of the light emitting surface, and the full width at half maximum was 22.5 degrees.
- the prism array forming surface faces the light emitting surface (mat surface) side of the light guide, and the prism array ridge line is formed on the light incident end surface of the light guide.
- the prisms were placed so that they were parallel and the flat prism faces of each prism row faced toward the light incident end face of the light guide.
- the primary light source was turned on under the same conditions as in Example 10, and the light emitting surface was visually observed. And a bright line was observed in the vicinity of the light guide light incident end face.
- Example 10 In the same manner as in Example 10, a portion corresponding to the light incident end face of the light guide material was cut to obtain a light guide having a light incident end face formed as a cut face. By the cutting process, a protruding portion (protruding portion) was formed at the boundary between the light incident end surface and the light emitting surface so as to protrude from the other region of the light emitting surface. The protrusion had a height of and a full width at half maximum of 10 / z m.
- ink dots were formed and leveled to form an ink layer. However, the position of the ink dot formation region was set such that the ink layer reached the protruding portion by leveling.
- the primary light source was turned on, and the light emitting surface was visually observed. And the dark line in the display area were almost inconspicuous.
- FIG. 1 is a schematic perspective view showing one embodiment of a surface light source device according to the present invention.
- FIG. 2 is a schematic plan view showing a light guide together with a primary light source.
- FIG. 3 is a diagram for explaining an example of a method for manufacturing a light guide according to the present invention.
- FIG. 4 is a diagram for explaining an example of a method for manufacturing a light guide according to the present invention.
- FIG. 5 is a view showing a state of light deflection by a light deflection element.
- FIG. 6 is a schematic plan view showing a light diffusion element together with a primary light source.
- FIG. 7 is a schematic partial cross-sectional view of a liquid crystal display device using the surface light source device according to the present invention as a backlight.
- FIG. 8 is a schematic partial cross-sectional view of a light guide.
- FIG. 9 is a schematic partial cross-sectional view of a light guide.
- FIG. 10 is a view showing a light guide and a visible light transmittance of a light absorption band.
- FIG. 11 is a view showing a light guide and a visible light transmittance of a light absorption band.
- FIG. 12A is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 12B is an explanatory view showing an example of a method for manufacturing a light guide.
- FIG. 13A is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 13B is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 14A is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 14B is an explanatory view showing an example of a method for manufacturing a light guide.
- FIG. 14C is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 14D is an explanatory diagram showing an example of a method for manufacturing a light guide.
- FIG. 15 is a partial sectional view of a light guide.
- FIG. 16 is an enlarged view of an edge portion of the light guide.
- FIG. 17 is an enlarged view of an edge portion of the light guide.
- FIG. 18 is an enlarged view of an edge portion of the light guide.
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2005513884A JPWO2005026612A1 (ja) | 2003-09-09 | 2004-09-09 | 面光源装置及びそれに用いる導光体及びその製造方法 |
US10/571,078 US20070031106A1 (en) | 2003-09-09 | 2004-09-09 | Surface light source device and light guide using it and method therefor |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP2003-317291 | 2003-09-09 | ||
JP2003317291 | 2003-09-09 | ||
JP2004-112127 | 2004-04-06 | ||
JP2004112127 | 2004-04-06 |
Publications (1)
Publication Number | Publication Date |
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WO2005026612A1 true WO2005026612A1 (ja) | 2005-03-24 |
Family
ID=34315639
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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PCT/JP2004/013099 WO2005026612A1 (ja) | 2003-09-09 | 2004-09-09 | 面光源装置及びそれに用いる導光体及びその製造方法 |
Country Status (5)
Country | Link |
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US (1) | US20070031106A1 (ja) |
JP (1) | JPWO2005026612A1 (ja) |
KR (1) | KR20060063965A (ja) |
TW (1) | TW200519320A (ja) |
WO (1) | WO2005026612A1 (ja) |
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WO2008069324A1 (ja) * | 2006-12-08 | 2008-06-12 | Mitsubishi Rayon Co., Ltd., | 光拡散性光学フィルム及びその製造方法、プリズムシート、並びに面光源装置 |
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Also Published As
Publication number | Publication date |
---|---|
US20070031106A1 (en) | 2007-02-08 |
TW200519320A (en) | 2005-06-16 |
JPWO2005026612A1 (ja) | 2006-11-24 |
KR20060063965A (ko) | 2006-06-12 |
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