CN1849481A - Surface light source device and light guide using it and production method therefor - Google Patents

Abstract

A planar light source device capable of preventing the occurrence of a luminescent line in the vicinity of a light incident end face without interrupting an incident light incoming from a primary light source and entering at a light incident end face, and being not likely to cause a decrease in incident light quantity, that is, without lowering entire luminance and producing dark lines to be caused when light to be originally guided is shaded. A platy light guide ( 3 ) that guides light emitted from a primary light source ( 1 ) and has a light incident end face ( 31 ) for receiving light from the primary light source ( 1 ) and a light emitting face ( 33 ) for outputting the guided light which is formed with a light absorption zone ( 36 ) extending along the light incident end face ( 31 ) and having a width of 50 to 1000 mum, and a side edge closer to the light incident end face ( 31 ) of the light absorption zone ( 36 ) is up to 300 mum away from the light incident end face ( 31 ). The light incident end face ( 31 ) is so constructed that light emitted from the primary light source ( 1 ) is incident as far as the boundary with the light emitting face ( 33 ).

Description

Planar light source device and its used light conductor and manufacture method thereof

Technical field

The present invention relates to planar light source device and its used light conductor of edge light mode, specifically, relate to seek with main light source light conductor light-incident end in opposite directions near along this light-incident end can be used as the inhomogeneous planar light source device that reduces of Luminance Distribution that the bright line of muscle shape and/or concealed wire observe and its special-purpose light conductor and manufacture method thereof.

Planar light source device of the present invention is applicable to for example back lighting of liquid crystal indicator.

Background technology

In recent years, liquid crystal indicator can be used as the monitor of portable notebook PC etc. or as LCD TV, have the display part of the LCD TV etc. of video playback, can be used widely in other all fields in addition.Liquid crystal indicator can be made of back lighting portion and liquid crystal display cells portion basically.As back lighting portion,, often use the edge light mode from the viewpoint of liquid crystal indicator densification.In the past, as the back lighting of edge light mode widely used be with the light conductor of rectangular plate shape wherein at least one end face as light-incident end, along wire or bar-shaped main light sources such as this light-incident end configuration straight-pipe fluorescent lamps, light that this main light source sends is directed into light conductor inside from the light-incident end of light conductor, and one of them is this back lighting of light-emitting face outgoing from 2 interareas of this light conductor.

This back lighting, because main light source sends the transmission means through the light of light conductor outgoing, the Luminance Distribution of light-emitting area often has inhomogeneous generation (luminance uniformity is low).As the low a kind of mode of this luminance uniformity, can exemplify the high situation in other zones of its brightness ratio of zone near main light source.

As the method that prevents that this luminance uniformity is low, for example Japanese real public clear 40-26083 communique (patent documentation 1), real public clear 60-60788 communique (patent documentation 2) and real opening have disclosed the film that has light absorption on the position of light-emitting face near main light source that is configured in light conductor or have suppressed this method of light adjustment film that printing opacity is used in the clear 62-154422 communique (patent documentation 3).This method as the light conductor light-emitting face near the strength ratio of the regional institute emergent light of main light source in the big this countermeasure of regional institute outgoing light intensity away from main light source, be this method of light outgoing of managing the little light-emitting face zone of only restriction and main light source distance.

But in recent years along with the slimming of light conductor progress (for example about 2～3mm), as the low particular form of above-mentioned luminance uniformity, often corresponding to can be observed the bright bright portion's (bright line) of muscle shape around the ratio parallel near the light-emitting face position of (for example about 2mm) with light-incident end with the light-incident end of light conductor.Adopt above-mentioned patent documentation 1～3 this method to prevent the words that this bright line causes luminance uniformity to reduce, because its width such as formed light absorping film is bigger, therefore produce not only bright line and also around it overall brightness all descend to some extent or this problem of concealed wire take place easily.

On the other hand, as the method that is used to prevent that this bright line from causing luminance uniformity to reduce, Japanese kokai publication hei 9-197404 communique (patent documentation 4) has proposed to add this methods of shading material such as black liquid with the formed edge of light-emitting face and opposite laterodorsal border thereof at the light-incident end of light conductor.

And, along with the generation of bright line as mentioned above, often can be observed the ratio parallel dark portion (concealed wire) of dark muscle shape on every side between adjacent bright lines with light-incident end.Japanese kokai publication hei 8-227074 communique (patent documentation 5) has disclosed formed light absorbing zone as the method that prevents this concealed wire generation and has had absorptivity along with this method of light absorption pattern that slowly reduces away from light-incident end.

Patent documentation 1: the real public clear 40-26083 communique of Japan

Patent documentation 2: Japan opens clear 60-60788 communique in fact

Patent documentation 3: Japan opens clear 62-154422 communique in fact

Patent documentation 4: Japanese kokai publication hei 9-197404 communique

Patent documentation 5: Japanese kokai publication hei 8-227074 communique

The method of above-mentioned patent documentation 4 is the methods at the additional light-proofness material in the edge of light conductor light-incident end, because this a light-proofness material wherein part also is added on the light-incident end, so the incident light of this a light-incident end wherein part is covered, the light quantity that incides light conductor from main light source just reduces this part, overall brightness reduces easily, also covering in the middle of near the edge the incident light does not simultaneously have the just light of leaded light of light-proofness material, therefore exists the viewing area that this problem of concealed wire takes place easily.

And this method is owing to form the very narrow light-proofness material of width, and therefore the inhibition effect that takes place for bright line can't be said very abundant.And its problem of this method is, is very difficult to realize in the practice that the light-proofness material is additional to the edge, and it is also very difficult to form the light-proofness material in desirable position, and the light-proofness material that the edge added comes off etc. easily.

In addition, in the method for above-mentioned patent documentation 5, patterns such as employing dot pattern are as light absorption pattern, but in this case, owing to exist the part to the non-absorbent zone of light, this regional shading is abundant inadequately, so existence can be observed problems such as bright line.

Summary of the invention

According to the present invention, can provide a kind of planar light source device light conductor as the scheme that solves above-mentioned technical task, light that main light source sends is carried out leaded light, and have and allow described main light source send the light-incident end of light incident and allow by the light-emitting face of the light outgoing of leaded light

It is 50 microns～1000 microns optical absorption band that described light-emitting face is formed with the width that extends along described light-incident end, this optical absorption band near the lateral margin of described light-incident end be distance from described light-incident end be 300 microns or below.

In the present invention's one mode, described optical absorption band forms, and compares with the lateral margin near described light-incident end, and the transmission of visible light of lateral margin far away is higher.In the present invention's one mode, the transmission of visible light of described optical absorption band near the lateral margin of described light-incident end to away from lateral margin by at least 2 phase change.In the present invention's one mode, the transmission of visible light of described optical absorption band near the lateral margin of described light-incident end to away from lateral margin wherein at least a portion change continuously.

In the present invention's one mode, its minimum of the transmission of visible light of described optical absorption band is in 0%～60% scope, and peak is in 40%～90% scope.In the present invention's one mode, described optical absorption band is formed by the black coating material.In the present invention's one mode, described black coating material be evaporation drying type China ink liquid, thermohardening type China ink liquid and ultraviolet hardening China ink liquid wherein any.

In the present invention's one mode, described optical absorption band comprises light diffusing particulate or light absorption particulate.In the present invention's one mode, the surface of described optical absorption band is formed with micro concavo-convex.In the present invention's one mode, the protuberance of the micro concavo-convex on the surface of described optical absorption band is formed by light diffusing particulate that is comprised in this optical absorption band or light absorption particulate.

In the present invention's one mode, its radius of curvature of marginal portion that forms the border of described light-emitting face and described light-incident end be 50 microns or below.In the present invention's one mode, the marginal portion that forms the border of described light-emitting face and described light-incident end forms the protuberance that swells with respect to other zones of described light-emitting face along described light-incident end, here, described protuberance is 1～50 micron from the height of described light-emitting face, and/or its halfwidth of described protuberance is 1～50 micron.

In the present invention's one mode, it is 0 micron near the lateral margin of described light-incident end and the distance of described light-incident end for described optical absorption band.In the present invention's one mode, the width of described optical absorption band be described light conductor 0.4 times of the thickness of light-incident end position or below.In the present invention's one mode, described light-incident end constitutes and allows light that described main light source sends be incident to till the border of itself and described light-emitting face.

In the present invention's one mode, described light conductor is formed with light outgoing mechanism on described light-emitting face and/or its opposition side back side.In the present invention's one mode, described smooth outgoing mechanism is formed by asperities.In the present invention's one mode, described smooth outgoing mechanism is formed at described light-emitting face, and the described back side is formed with a plurality of prisms row that extend and be parallel to each other on the roughly orthogonal direction of described light-incident end.In the present invention's one mode, it is 85 °～110 ° that described prism is listed as its drift angle.In the present invention's one mode, described light-incident end is through asperities processing.

Also provide the manufacture method of a kind of planar light source device according to the present invention with light conductor, it is characterized in that, being included in the light-emitting face correspondence portion of light conductor material at least, the zone near light-incident end correspondence portion forms optical absorption band correspondence portion, after this described light-incident end correspondence portion is carried out machining, form the operation of described light-incident end.

In the present invention's one mode, also cut the side edge part of removing close described light-incident end correspondence portion of described optical absorption band correspondence portion in the described machining simultaneously.In the present invention's one mode, form described optical absorption band correspondence portion by being coated with black liquid.In the present invention's one mode, utilize ink jet printing, serigraphy, wiping printing (printing of Application Port) or thermal transfer printing to form.

Also provide the manufacture method of a kind of planar light source device according to the present invention with light conductor, it is characterized in that, by utilizing ink-jet method to spray black liquid from a plurality of nozzles, it forms the black liquid point of separate or partial continuous at least near the zone of light-incident end at the light-emitting face of light conductor, then be bonded to each other by making this China ink liquid put its adjacent part, be formed on continuous black liquid layer in the whole described regional extent, after this form described optical absorption band by this China ink liquid layer is solidified.

In the present invention's one mode, utilize the described leveling time to control the bonding state of the black liquid point of described black liquid layer.In the present invention's one mode, control the surface state of described optical absorption band by the bonding state of controlling described black liquid point.In the present invention's one mode, the ultraviolet hardening China ink liquid that described black liquid is black carries out the ultraviolet ray irradiation for described black liquid layer is solidified.In the present invention's one mode, the light-incident end correspondence portion of light conductor material is carried out machining form described light-incident end, after this form described optical absorption band.In the present invention's one mode, its lateral margin position near described light-incident end, described zone is set at described black liquid layer and arrives by described machining till the outstanding formed protuberance of described light-emitting face direction.

In the present invention's one mode, described black liquid is the ultraviolet hardening China ink liquid that comprises (methyl (メ )) acrylate monomer and/or organic solvent.In the present invention's one mode, described (methyl) acrylate monomer and/or organic solvent its count mean molecule quantity be 100 or more than.In the present invention's one mode, described (methyl) acrylate monomer is a methyl methacrylate, and/or contain 0.5～10 weight % in described black liquid.In the present invention's one mode, described organic solvent is that boiling point is 60 ℃ or above solvent, and/or to comprise methyl ethyl ketone, ethyl acetate, chloroform, acetate methylcellulose and methacrylic acid wherein at least a.

Also provide a kind of planar light source device according to the present invention, it is characterized in that, comprise aforesaid planar light source device light conductor; Described main light source with the described light-incident end disposed adjacent of this light conductor; And with the light deflection element of the light-emitting face disposed adjacent of described light conductor, this light deflection element has and is in that the light receiving surface of position and the photoconduction of its opposition side are appeared in opposite directions with the light-emitting face of described light conductor, on the light receiving surface of described light deflection element, have a plurality of prisms row that on the almost parallel direction of the light-incident end of described light conductor, extend and be parallel to each other.

In the present invention's one mode, a plurality of prisms of the light receiving surface of described light deflection element row comprise 2 faceted pebbles respectively, and one of them incident light of this faceted pebble utilizes wherein another total reflection of described faceted pebble.In the present invention's one mode, with the photoconduction of the described light deflection element disposed adjacent of appearing light diffusion element is arranged, this light diffusion element has dot pattern portion, this dot pattern portion forms the light absorption dot pattern in light-incident end 2mm position to the zone of the width of 4mm position of described light conductor comprising at least, and this dot pattern portion is that the decentralized configuration diameter is that 30 microns～70 microns the light absorption coating material of point-like is formed.In the present invention's one mode, its transmission of visible light of dot pattern portion of described light diffusion element is 60%～95%.

Utilize aforesaid the present invention, by form the optical absorption band of the thinner specific width of extending along this light-incident end near the position of light-incident end at the light-emitting face of light conductor, avoid covering from the incident light of main light source for light-incident end, and avoid reducing from the incident light quantity of main light source to light conductor, promptly avoid overall brightness to reduce or cover the light that should conduct causing concealed wire to take place, can prevent near the light-incident end bright line to take place.

And, utilize the present invention, just the light-emitting face of light conductor forms optical absorption band, so it makes easily, and formed optical absorption band is not easy to come off, and can bring into play the effect that prevents that above-mentioned bright line from taking place for a long time well.

In addition, utilize the present invention, by after forming optical absorption band correspondence portion on the light conductor material light-incident end correspondence portion being carried out machining to form light-incident end, can be easy to make optical absorption band is 0 micron near the lateral margin of light-incident end and the distance of light-incident end.

In addition, utilize the present invention, by on the light-emitting face of light conductor, forming black liquid point with black liquid spraying process, then make black liquid point leveling and the size of black liquid point is strengthened, the part of filling up uncoated black liquid with black liquid forms continuous black liquid layer, and black liquid layer is solidified, form optical absorption band, therefore the leveling time that can be required, control the bonding state of black liquid layer China and Mexico liquid point, thereby be easy to control the surface state of optical absorption band according to the viscosity degree set of black liquid.

Description of drawings

Fig. 1 is the schematic perspective view that planar light source device one embodiment of the present invention is shown.

Fig. 2 is with the schematic plan shown in the main light source with light conductor.

Fig. 3 is the key diagram of the present invention's one routine light conductor manufacture method.

Fig. 4 is the key diagram of the present invention's one routine light conductor manufacture method.

Shown in Fig. 5 is the situation that light deflection element carries out light deflection.

Fig. 6 is with the schematic plan shown in the main light source with light diffusion element.

Fig. 7 is the schematic partial cross-sectional view that planar light source device of the present invention forms the liquid crystal indicator of back lighting.

Fig. 8 is the schematic partial cross-sectional view of light conductor.

Fig. 9 is the schematic partial cross-sectional view of light conductor.

Shown in Figure 10 is the transmission of visible light of light conductor and optical absorption band.

Shown in Figure 11 is the transmission of visible light of light conductor and optical absorption band.

Figure 12 A is the key diagram that the manufacture method example of light conductor is shown.

Figure 12 B is the key diagram that the manufacture method example of light conductor is shown.

Figure 13 A is the key diagram that the manufacture method example of light conductor is shown.

Figure 13 B is the key diagram that the manufacture method example of light conductor is shown.

Figure 14 A is the key diagram that the manufacture method example of light conductor is shown.

Figure 14 B is the key diagram that the manufacture method example of light conductor is shown.

Figure 14 C is the key diagram that the manufacture method example of light conductor is shown.

Figure 14 D is the key diagram that the manufacture method example of light conductor is shown.

Figure 15 is the part sectioned view of light conductor.

Figure 16 is the enlarged drawing of the marginal portion of light conductor.

Figure 17 is the enlarged drawing of the marginal portion of light conductor.

Figure 18 is the enlarged drawing of the marginal portion of light conductor.

The specific embodiment

Embodiments of the present invention are described with reference to the accompanying drawings.

Fig. 1 is the schematic perspective view that planar light source device one embodiment of the present invention is shown.As shown in Figure 1, the planar light source device of present embodiment comprises following formation: with at least one side end face as light-incident end 31, will with its roughly a surface of quadrature as the light conductor 3 of light-emitting face 33; Dispose the main light source 1 of the wire that covers by light source reflector 2 in opposite directions with the light-incident end 31 of this light conductor 3; Be disposed at the light deflection element 4 on the light-emitting face of light conductor 3; With appear light diffusion element 6 on 42 of its photoconduction that is disposed at light deflection element 4 in opposite directions; And the light reflection element 5 that disposes in opposite directions with the back side 34 of the opposition side of the light-emitting face 33 of light conductor 3.

Light conductor 3 and the configuration of XY plane parallel, whole rectangular tabular.Light conductor 3 has 4 side end faces, wherein with the parallel plane 1 pair of side end face of YZ in the middle of at least one side end face as light-incident end 31.Light-incident end 31 disposes in opposite directions with main light source 1, and main light source 1 light that sends incides in the light conductor 3 from light-incident end 31.Among the present invention, also can wait other side end faces also to dispose light source in opposite directions for the side end face 32 of the opposition side of light-incident end 31.

With the light-incident end 31 of light conductor 3 roughly 2 interareas of quadrature be in position with XY plane almost parallel respectively, wherein arbitrary (being upper surface among the figure) is light-emitting face 33.By to this light-emitting face 33 and its back side 34 wherein at least one side give the formed directive property light of the lens face outgoing mechanism that forms side by side by the formed directive property light of asperities outgoing mechanism, by many lens arrays such as prism row, biconvex lens row, V word shape groove and light-incident end 31 almost parallels etc., make incident light leaded light in light conductor 3 of light-incident end 31, the light that in the normal surface (XZ plane) of light-incident end 31 and light-emitting face 33, has directive property from light-emitting face 33 outgoing.Its peak value direction (peak light) of emergent light light distribution that distributes in this XZ plane is α with light-emitting face 33 angulations.This angle [alpha] is for example 10～40 °, and its halfwidth of emergent light light distribution is for example 10～40 °.

The surperficial formed asperities of light conductor 3, its average slope angle θ a that stipulates according to ISO4287/1-1984 of lens arrays consider to wish to get the angle of 0.5～15 ° of scope from the uniformity of seeking brightness in the light-emitting face 33.Average slope angle θ a it is desirable to 1～12 ° of scope, and even more ideal is 1.5～11 ° of scopes.This average slope angle θ a preferably sets optimum range according to the thickness t of light conductor 3 and the length L ratio between two L/t of the incident light institute direction of propagation.Specifically, using L/t as light conductor 3 is that average slope angle θ a wishes to get 0.5～7.5 °, it is desirable to 1～5 ° of scope under the situation of about 20～200 light conductor, and even more ideal is 1.5～4 ° of scopes.And as light conductor 3 use L/t be 20 or the situation of following light conductor under, average slope angle θ a it is desirable to 7～12 ° of scopes, even more ideal is 8～11 ° of scopes.

Its average slope angle of formed asperities θ a on the light conductor 3, regulation according to ISO4287/1-1984, adopting contact pin type surface roughness meter that the asperities shape is measured, is the slant function f (x) that x obtains according to the coordinate of measuring direction, with following formula (1) and formula (2) can in the hope of

$a=(1/L){\∫}_0^L\left|(d/\mathrm{dx})f\left(x\right)\right|\mathrm{dx}...\left(1\right)$

θa＝tan ^-1(Δa) (2)

Wherein, L is a measured length, and Δ a is the tangent of average slope angle θ a.

And it is desirable to its light exitance as light conductor 3 is light conductor in 0.5～5% scope, and even more ideal is 1～3% scope.This be because, the light exitance is less than 0.5% words, often the outgoing light quantity of light conductor 3 reduces, can't obtain enough brightness, and the light exitance is greater than 5% words, most of light outgoing is often arranged near the main light source 1, its decay of the emergent light of light-emitting face 33 interior directions Xs is remarkable, and the luminance uniformity of light-emitting face 33 reduces.By like this light exitance of light conductor 3 being set at 0.5～5%, the peak light angle on () of can distributing from the emergent light intensity of the emergent light of light conductor 3 its light-emitting faces of outgoing is in 50～80 ° of scopes, is the light of the high outgoing characteristic of 10～40 ° of this directive property with the halfwidth of the emergent light intensity distribution (in the XZ plane) on the light-incident end XZ plane vertical with light-emitting face with respect to the normal of light-emitting face on XZ the plane in, can make its exit direction deflection effectively with light deflection element 4, thereby a kind of planar light source device of high brightness can be provided.

Among the present invention, the light exitance of light conductor 3 is defined as follows.Light-emitting face 33 is by the light intensity I of the emergent light of light-incident end 31 1 side edge ₀With with the relation of light-incident end 31 1 side edge at a distance of the emergent light light intensity I of the position of L, this relation of formula (3) below satisfying

I＝I ₀(α/100)[1-(α/100)] ^L/t (3)

Wherein the thickness of light conductor 3 (z direction size) is t.Here, constant alpha is the light exitance, be on the light-emitting face 33 with the directions X of light-incident end 31 quadratures on the light outgoing ratio (%) of per unit length (length that is equivalent to the light conductor thickness t) light conductor 3.This light exitance α can get the logarithm of the emergent light light intensity of light-emitting face 23 by the longitudinal axis, and transverse axis is got L/t, and draws both relations, obtains according to its slope.

And, for the directive property of emergent light on the plane that parallels with main light source 1 (YZ plane) of controlling light conductor 3, another interarea of not giving directive property light outgoing mechanism preferably is formed on the last many prisms row that extend of the direction (directions X) that is approximately perpendicular to light-incident end 31 and arranges the lens face that forms.In the embodiment shown in Figure 1, light-emitting face 33 forms asperities, and the back side 34 is formed on the direction (directions X) that is approximately perpendicular to light-incident end 31 and goes up the many prisms row that extend and arrange the lens face that forms.Also can be opposite among the present invention with mode shown in Figure 1, light-emitting face 33 forms lens face, and the back side 34 forms asperities.

As shown in Figure 1, the back side 34 or light-emitting face 33 at light conductor 3 form under the situation of lens arrays, can exemplify the prism row that on directions X roughly, extend, biconvex lens row, V word shape groove etc. as this lens arrays, but preferably the YZ section shape is the prism row of general triangular.

Among the present invention, the back side of light conductor 3 34 forms prisms and is listed as under the situation as lens arrays, wishes that its drift angle is 85～110 ° of scopes.This be because, can the emergent light appropriateness of light conductor 3 be concentrated by drift angle being set at this scope, the brightness that can seek to improve planar light source device it is desirable to 90～100 ° of scopes.

In the light conductor of the present invention, for accurately making desirable prism row shape and obtaining stable optical property, simultaneously when suppressing assembly working, when using as light supply apparatus the prism top wearing and tearing or be out of shape this purpose, also can be in the top of prism row formation evener or curved face part.

In addition, among the present invention, also can by sneak in light conductor inside, dispersed light diffusivity particulate gives directive property light outgoing mechanism, form light outgoing mechanisms or this two kinds of mechanisms and use to be substituted in aforesaid light-emitting face 33 or its back side 34.

In order to regulate the light broadening in the XY plane and/or in the XZ plane, light-incident end 31 preferably carries out the asperities processing.As asperities formation method, can exemplify with milling cutter tools etc. carry out machining method, with emery wheel, sand paper, polishing wheel etc. carry out abrasive method, based on the method for sandblast processing, discharge processing, electrolytic polishing, chemical grinding etc.As the used sandblast particle of sandblast processing, can exemplify this spherical sand grains of bead, this polygon sand grains of alumina bead, wherein can form the effective asperities of light broadening with polygon sand grains method, therefore comparatively desirable.Can form anisotropic asperities by the machine direction of adjusting machining, attrition process.In order to regulate the light broadening in the XY plane, can adopt the machine direction of Z direction to form the muscle shape concaveconvex shape of Z direction, in order to regulate the light broadening in the XZ plane, can adopt the machine direction of Y direction to form the muscle shape concaveconvex shape of Y direction.This asperities processing also can directly be implemented the light-incident end of light conductor, but also can process part suitable with light-incident end in the mould, carries out transfer printing when its moulding.

The asperities degree of light-incident end 31, on the thickness direction of light conductor, average slope angle θ a be 1～5 °, center line average boldness Ra be 0.05～0.5 micron, 10 average boldness Rz be 0.5～3 micron comparatively desirable.This is because asperities degree set that can be by making light-incident end 31 can make the boundary of bright line and concealed wire blur simultaneously, be not easy resolution for this scope suppresses the generation of bright band or blanking bar.What average slope angle θ a was more satisfactory is 2～4.5 ° of scopes, it is desirable to 2.5～3 ° of scopes especially.What center line average boldness Ra was more satisfactory is 0.07～0.3 micrometer range, it is desirable to 0.1～0.25 micrometer range especially.What 10 average boldness Rz were more satisfactory is 0.7～2.5 micrometer range, it is desirable to 1～2 micrometer range especially.And, the asperities degree of light-incident end 31, in the longitudinal direction since with top described identical reason, thereby average slope angle θ a be 1～3 °, center line average boldness Ra be 0.02～0.1 micron, 10 on average spend mutually Rz be 0.3～2 micron comparatively desirable.What average slope angle θ a was more satisfactory is 1.3～2.7 ° of scopes, it is desirable to 1.5～2.5 ° of scopes especially.What center line average boldness Ra was more satisfactory is 0.03～0.08 micron, it is desirable to 0.05～0.07 micrometer range especially.What 10 average boldness Rz were more satisfactory is 0.4～1.7 micron, it is desirable to 0.5～1.5 micrometer range especially.

The light-emitting face 33 of light conductor is formed with the optical absorption band 36 that extends along light-incident end 31.This optical absorption band 36 can the coating material of black forms by for example being coated with.The formation of optical absorption band 36 is not particularly limited, but can form by for example black liquid of coating, it is desirable to utilize ink jet printing, serigraphy, wiping printing (printing of Application Port) or thermal transfer printing to form especially.And, as the material of optical absorption band 36, consider to wish use the rapid-drying properties material from the production efficiency viewpoint, drying time it is desirable to 60 seconds or below, more satisfactory is 40 seconds or below, even more ideal is 20 seconds or below.As such optical absorption band material, the organic solvent that can enumerate organic solvents such as for example using methyl ethyl ketone, (methyl) acrylate monomer etc. is coating material, evaporation drying type China ink liquid or thermohardening type China ink liquid or ultraviolet hardening coating material, ultraviolet hardening China ink liquid etc.This optical absorption band is by absorbing at least a portion of through light in the middle of the light that imports in the light conductors 3 from light-incident end 31, prevent near the generation of light-incident end 31 bright lines, therefore transmission of visible light (JIS-K7105B) is for example 0～90%, more satisfactory is 0～60%, even more ideal is 2～45%, it is desirable to 4～30% especially.And what optical absorption band 36 its reflectivity (JIS-K7105B) were more satisfactory is 0～20%, and even more ideal is 0～15%.In addition, take place for this bright line, can think that not reflecting the light that enters in the light conductor from light-emitting face 33 through light-incident end by light source reflector 2 has also played effect, and optical absorption band 36 is by also absorbing the generation that a part prevents bright line with this light.

Fig. 2 is with the schematic plan shown in the main light source 1 with light conductor 3.As shown in Figure 2, optical absorption band 36 reduces for inhibition incident light quantity under the situation of the incident light that does not cover light-incident end 31 reduces the brightness that is caused, answers light conducting to cause concealed wire to take place because of covering, need not be formed at light-incident end 31 only in light-emitting face 33 formation of light conductor 3.And optical absorption band 36 its width (directions X size) are W, and limiting in the middle of 2 lateral margins of its width near the lateral margin of light-incident end 31 and the distance of this light-incident end 31 is D.Width W is 50～1000 microns, it is desirable to 100～700 microns, it is desirable to 200～400 microns especially.50 microns of width less thaies, the often desired effect that prevents that bright line from taking place decreases, and width W surpasses 1000 microns, concealed wire or overall brightness often takes place reduce.Width W it is desirable to 0.4 times of thickness of light conductor 3 its light-incident end positions or below, even more ideal is 0.3 times or below, it is desirable to especially 0.2 times or below.And distance D is 300 microns or following, can obtain the above-mentioned effect that prevents that bright line from taking place, it is desirable to 200 microns or below, it is desirable to especially 100 microns or below.

Also can when optical absorption band 36 being formed at the light-emitting face 33 of light conductor 3, form at least a portion formation recess at position, wait at this recess coating coating material to form optical absorption band the optical absorption band of light-emitting face 33.Specifically, as Fig. 8 and shown in Figure 9, optical absorption band 36 forms and for example forms on light-emitting face 33 that section is the recess 70 of triangle or lenticular shapes, and for example form 150 microns of the degree of depth or below, it is desirable to form 100 microns or the following degree of depth, even more ideal is to form 50 microns or the following degree of depth, and comprises the inside of this recess.The degree of depth of this recess 70 is excessive, and the conduction mode in the light conductor is defectiveness just, occurs concealed wire easily.

As light conductor 3, be not limited to this shape shown in Figure 1, can use the thicker various shapes such as wedge-like of light-incident end side.

One routine manufacture method of aforesaid light conductor is described with Fig. 3 and Fig. 4 below.

Fig. 3 illustrates to utilize resin forming to be processed to form, to be coated with the schematic plan as the resulting light conductor material 3 ' of the coating material of optical absorption band.In the time of will illustrating as corresponding portion with the corresponding part of each of the light conductor 3 that finally obtains, this light conductor material 3 ' has light-incident end correspondence portion 31 ', light-emitting face correspondence portion 33 ' and optical absorption band correspondence portion 36 '.Light-emitting face correspondence portion 33 ' is formed with the frosted face as the asperities that constitutes required light outgoing mechanism, and the back side correspondence portion of its opposition side then is formed with required prism row.Light-emitting face correspondence portion 33 ' is formed with optical absorption band correspondence portion 36 ' near the zone of light-incident end correspondence portion 31 '.

As shown in Figure 4, light-incident end correspondence portion 31 ' is carried out machining excise part not, be formed with light-incident end 31 as the machining face.By means of this, can be easy to light-incident end 31 is constituted till main light source 1 light that sends incides the border of itself and light-emitting face 33.And, as shown in Figure 3 and Figure 4, by till optical absorption band correspondence portion 31 ' being formed up to not part by machining excision, also cut simultaneously in the machining and remove optical absorption band correspondence portion 36 ' side edge part near light-incident end correspondence portion 31 ', can at an easy rate above-mentioned distance D be formed 0 micron, and light-incident end 31 is constituted till main light source 1 light that sends incides the border of itself and light-emitting face 33.

Light deflection element 4 is disposed on the light-emitting face 33 of light conductor 3.The configuration that is parallel to each other generally of 2 interareas 41,42 of light deflection element 4 is in generally the position with the XY plane parallel respectively.Interarea 41,42 one of them (light conductor 3 is positioned at the interarea of light-emitting face 33 1 sides) forms light receiving surface 41, and another forms photoconduction and appears 42.Photoconduction appears 42 to form the burnishing surface that parallels with the light-emitting face 33 of light conductor 3.Light receiving surface 41 forms many prism row formation faces that upwardly extending prism row are arranged parallel to each other in Y side.Prism row formation face also can be provided with the evener (for example be of a size of identical magnitude with the directions X of prism row or than the evener of its little width) of width relative narrower between adjacent prism row, but from improving light utilization ratio this point, wish evener is not set, but on directions X, arrange the prism row continuously.

Shown in Fig. 5 is the situation that light deflection element 4 carries out light deflection.What this illustrated is the direct of travel of the peak light (with the corresponding light of the photodistributed peak value of outgoing) of 3 outgoing of light conductor in the XZ plane.With respect to the light-emitting face 33 of light conductor 3 peak light with angle [alpha] inclination outgoing, be incident to the 1st of prism row, by the 2nd total reflection, almost be the photoconduction outgoing on 42 the normal direction of appearing.And, can utilize the prism row effect at the aforesaid light conductor back side 34 in the YZ plane, seek photoconduction 42 the abundant raisings of brightness on normal direction of appearing for the zone of relative broad range.

Its shape of prism facets of the prism of light deflection element 4 row is not limited to single plane, for example can form that section is convex polygon shape or convex curve surface shape, can seek high brightness, Narrow Field Of Vision thus.

In the light deflection element of the present invention, for accurately making desirable prism row shape and obtaining stable optical property, simultaneously when suppressing assembly working, when using as light supply apparatus the prism top wearing and tearing or be out of shape this purpose, also can be in the top of prism row formation evener or curved face part.In this case, reduce, suppress the viewpoint consideration that adhesion causes the brightness irregularities pattern to take place from the brightness that suppresses light supply apparatus, be formed at the evener at prism row top or its width of curved face part wish to form 3 microns or below, it is desirable to 2 microns or below, even more ideal is 1 micron or below.

Among the present invention, reduce, suitably control field range according to purposes in order to avoid brightness as far as possible, can be on the photoconduction of light deflection element 4 be appeared disposed adjacent light diffusion element 6.And, among the present invention, can be by such configuration light diffusion element 6, suppress to reduce the situations such as flicker, brightness spot of reason as quality, seek quality and improve.

Hope is given concaveconvex structure to the light diffusion element 6 and light deflection element 4 plane of incidence 61 in opposite directions, to prevent the adhesion with light deflection element 4.Equally, for the exit facet 62 of light diffusion element 6 also consider and the liquid crystal display cells of configuration on it between adhesion, wish also to give concaveconvex structure to the face of light diffusion element 6 its outgoing one sides.This concaveconvex structure is under the purpose situation of being given to prevent to adhere to just, wishes that forming average slope angle reaches 0.7 ° or above this structure, it is desirable to 1 ° or more than, even more ideal is 1.5 ° or more than.

The light diffusing of light diffusion element 6 can be by sneaking into the light diffusing agent for example independent condensate of silica bead, polystyrene, polymethyl methacrylate, fluorate acrylic acid methyl esters etc. or EVA etc. in light diffusion element 6, perhaps light diffusion element 6 is wherein formed concaveconvex structure and gives at least one surface.The concaveconvex structure that the surface forms is formed at light diffusion element 6 one of them surperficial situation and is formed at two its degree of surperficial situation different.Concaveconvex structure is formed under light diffusion element 6 one of them surperficial situation, and its average slope angle is advisable with 0.8～12 ° of scope, it is desirable to 3.5～7 °, and even more ideal is 4～6.5 °.Concaveconvex structure is formed under the situation on two surfaces of light diffusion element 6, and its average slope angle of concaveconvex structure that one of them surface forms is advisable with 0.8～6 ° of scope, it is desirable to 2～4 °, and even more ideal is 2.5～4 °.In this case, in order to suppress the reduction of light diffusion element 6 total light transmissions, the average slope angle of plane of incidence side that preferably makes light diffusion element 6 is greater than the average slope angle of exit facet side.

And the light diffused transmission rate ratio of light diffusion element 6 is got 8～82% scopes, but for the consideration that improves light characteristic and the visual identification of improvement, more satisfactory is 30～70% scopes, it is desirable to 40～65% scope more.

Fig. 6 is with the schematic plan shown in the main light source 1 with light diffusion element 6.As Fig. 1 and shown in Figure 6, light diffusion element 6 is formed with dot pattern portion 64.This dot pattern portion is that the decentralized configuration diameter is the formed pattern of light absorption coating material of 30 microns～70 microns point-like on the exit facet 62, is present in to comprise with the light-incident end of light conductor at a distance of the position of d1 to the zone at a distance of this width in position (d2-d1) of d2.Be 2mm or following preferably apart from d1, apart from d2 be 4mm or more than.Thus, can suitably suppress near the overall brightness in main light source position, thereby obtain the little Luminance Distribution of discomfort at light-emitting area.In order effectively to obtain such effect, dot pattern portion 64 preferably its transmission of visible light is 60～95%.And, in order to obtain the littler Luminance Distribution of discomfort, near at least a portion width regions the position of distance light-incident end d2 preferably, the distribution configuration density that makes point-like light absorption coating material is along with progressively reducing with the increasing of main light source distance.

Main light source 1 is upwardly extending linear light source in Y side, as this main light source 1, can use for example fluorescent lamp, cold-cathode tube.In this case, main light source 1 not only can wherein dispose a side end face with light conductor 3 as shown in Figure 1 in opposite directions, also can further also be configured in the side end face of opposition side as required.In addition, be not limited to linear light source as main light source 1 among the present invention, also can use led light source, Halogen lamp LED, this spot light of inferior halogen lamp.Particularly be used in mobile phone, portable data assistance etc. relatively under the situation than the display unit of small screen size, preferably use less spot lights such as LED.Like this, as under the situation of main light source 1, main light source 1 configuration also can be arranged at the bight of light conductor 3 etc. with spot light.In this case, the incident light of light conductor 3 conducts in light conductor for center roughly radially with main light source 1 in the plane identical with light-emitting face, therefore consider for brightness uniformity, wish that light-emitting face to light conductor 3 forms a plurality of prisms row and forms roughly arcuation side by side so that surround this smooth outgoing of spot light mechanism.And, the emergent light of the light-emitting face institute outgoing of light conductor 3 is center outgoing radially with main light source 1 too, therefore for the emergent light that makes outgoing radially like this and its exit direction irrespectively high efficiency deflect to desirable direction, consider for brightness uniformity that prism that hope will be formed at light deflection element 4 is listed as by circular shape roughly and be configured to surround main light source 1 side by side.

Light source reflector 2 is to make lead the less parts of light conductor 3 of the light loss of main light source 1.As its material, can use for example surperficial plastic sheeting with metal evaporation reflecting layer.As shown in the figure, light source reflector 2 is avoided light diffusion element 6 and light deflection element 4, reels to the light-emitting face end edge portion of light conductor 3 through the outside of main light source 1 from the end edge portion outer surface of light reflection element 5.On the other hand, light source reflector 2 also can only be avoided light diffusion element 6, reel from the end edge portion of light reflection element 5 outside through the outer photoconduction of main light source 1 end edge portion of appearing, perhaps reel through the outer exit facet end edge portion of main light source 1 towards light diffusion element 6 from the end edge portion outside of light reflection element 5 towards light deflection element 4.

Also the reflection part identical with this light source reflector 2 can be affixed on the side end face beyond the side end face 31 of light conductor 3.As light reflection element 5, can have the plastic sheet in metal evaporation reflecting layer with for example surface.Among the present invention, light reflection element 5 also can form formed reflecting layer such as the method for utilizing metal evaporation at the back side 34 of light conductor 3 and wait and replace reflector plate.

Light conductor 3 of the present invention, light deflection element 4 and light diffusion element 6 can be made of the high synthetic resin of light transmission.As this synthetic resin can the exemplified by methyl acrylic resin, acrylic resin, polycarbonate-based resin, polyester based resin, vinyl chloride-based resin.Methacrylic resin particularly, its hear resistance, mechanical property, moulding processability excellence, the most suitable.As such methacrylic resin, preferably methyl methacrylate is the resin of principal component, the ratio of methyl methacrylate be preferably 80 weight % or more than.During surface textures such as the asperities of formation light conductor 3, light deflection element 4 and light diffusion element 6 or filament surface textures such as (hairline), prism row or biconvex lens row, also can there be the mold part of desirable surface texture that the lucite plate is carried out hot pressing formation by apparatus, perhaps also can utilizes methods such as serigraphy, extrusion modling or ejection formation to give its shape simultaneously in moulding.In addition, also can utilize heat or light-cured resin etc. to form structural plane.In addition, also can on polyester based resin, acrylic resin, polycarbonate-based resin, vinyl chloride-based resin, polymethacrylimide are the surface of transparent bases such as the transparent membrane made such as resin or sheet material, form trachytic texture or the lens arrays arrangement architecture that utilizes the active energy ray-curable resin to make, also can utilize method such as bonding, welding that such sheet material is engaged with discrete transparent base one.As the active energy ray-curable resin, can use multifunctional (methyl) acyclic compound, vinyl compound, (methyl) esters of acrylic acid, acyclic compound, (methyl) acrylate metal salt etc.

On the light-emitting area (exit facet 62 of light diffusion element 6) of the light supply apparatus that aforesaid main light source 1, light source reflector 2, light conductor 3, light deflection element 4, light diffusion element 6 and light reflection element 5 are constituted, dispose liquid crystal display cells LC as shown in Figure 7, constituting with light supply apparatus of the present invention is the liquid crystal indicator of back lighting.Among Fig. 7, the point-like light absorption coating material of the decentralized configuration of the dot pattern portion of formation light diffusion element 6 illustrates with label 64 '.Liquid crystal indicator is that the top of observer from Fig. 7 observed by liquid crystal display cells LC.

Shown in Fig. 7 is that above-mentioned distance D is 0 micron a situation in the light conductor 3.As shown in the figure, optical absorption band 36 extends to till the border with light-incident end 31, but does not extend on the light-incident end 31.That is to say that light-incident end 31 constitutes main light source 1 light that sends and incides till the border with light-emitting face 33.

In the middle of importing light in the light conductors 3 from light-incident end 31, the light L1 that directly arrives optical absorption band 36 can absorb its more than half part by this optical absorption band.All the other light are then for to be reflected in the light L2 that advances in the light conductor by light-emitting face 33.This light L2 34 outgoing from the back side are incided in the light conductor by reflecting element 5 reflections, once again from light-emitting face 33 outgoing.Among the present invention, light L2 since the absorption of optical absorption band 36 thus become than a little less than the light L1 many, therefore be not the reason that bright line takes place.If optical absorption band 36 non-existent words, just the intensity of this light L2 is quite strong.This light L2 adds the maximum reason that its reverberation of part that optical absorption band 36 is arranged is the bright line generation among the present invention, tangible bright line takes place under optical absorption band 36 non-existent situations.

And the part in the middle of the light that main light source 1 sends is reflected by light source reflector 22, is not to arrive light-incident end 31, but arrives optical absorption band 36, and its more than half part is absorbed here.If, optical absorption band 36 non-existent words, light is additional from the present invention to have the light exit side face 33 at optical absorption band 36 positions to enter in the light conductor just have.This light also belongs to the occurrence cause of above-mentioned bright line, and this also issues the line that blazes in the situation that does not have optical absorption band 36 to exist on the one hand.

Among the present invention, can make the light of the narrower Luminance Distribution of having of abundant collimation (in the XZ plane) be incident to liquid crystal display cells LC from light supply apparatus, therefore can access liquid crystal display cells and not have gray scale counter-rotating etc. and brightness, uniform hue preferable image display, the illumination that can obtain simultaneously concentrating on desired direction is penetrated, can the high efficiency utilization at the amount of emitted light of the main light source 1 of this directional lighting.

In the explanation of above-mentioned embodiment, be to have on width roughly uniformly to optical absorption band 36 that the situation of optical absorption characteristics describes, but optical absorption band also can be that its optical absorption characteristics changes on width to some extent among the present invention.As the ideal style of this optical absorption characteristics, can exemplify form with the lateral margin of the light-incident end apart from each other of optical absorption band 36 with compare the higher this mode of its transmission of visible light at a distance of nearer lateral margin.By forming this mode, can prevent that light conductor light-emitting face 33 is formed with and is not formed with the rapid variation of optical absorption band 36 the two its light absorption of interregional border, further reduce brightness irregularities and take place.

For instance, as shown in figure 10, go up by constituting at width (directions X) by making optical absorption band 36 near the 1st regional 36-1 of light-incident end with away from the 2nd these two parts of regional 36-2 of this light-incident end, and to make the 1st regional 36-1 thickness be about twice of the 2nd regional 36-2 thickness, can make the transmission of visible light T2 of the 2nd regional 36-2 be higher than the transmission of visible light T1 of the 1st regional 36-1.This transmission of visible light is by the optical absorption band 36 of 2 phase change, can be by carrying out the coating of coating material to the 1st regional 36-1 and the 2nd regional 36-2 by uniform thickness earlier, and the coating of only the 1st regional 36-1 being appended coating material obtains then.Equally, can form the optical absorption band that transmission of visible light changes by 3 or above stage.

And, as shown in figure 11, also can upward progressively reduce at the width (directions X) of optical absorption band 36, the transmission of visible light of optical absorption band 36 is changed on the width of optical absorption band 36 continuously by the thickness that makes optical absorption band 36 from lateral margin to lateral margin away from this light-incident end 31 near light-incident end 31.The optical absorption band 36 of this mode can by make mask parts on directions X near a side shifting of light-incident end 31 to its away from the side coating of carrying out coating material obtain.Its continuous variation of the transmission of visible light of optical absorption band 36 can not be to relate to whole width scope yet, but wherein a part of on the width.

And the variation of the transmission of visible light of optical absorption band 36 also can be that the continuity of the phasic Chang of just Figure 10 explanation and just Figure 11 explanation changes both combinations.

The transmission of visible light of optical absorption band 36 it is desirable to minimum in 0%～60% scope and also peak in 40%～90% scope.Since in this scope, thus the effect that prevents that bright line from taking place can be kept, and fully prevent the generation of concealed wire, can further reduce the generation of brightness irregularities.

Other manufacture method examples of aforesaid light conductor are described with Figure 12 A, Figure 12 B, Figure 13 A and Figure 13 B below.Figure 12 A and Figure 13 A are partial top view, and Figure 12 B and Figure 13 B are the profiles of its XZ part.

At first, shown in Figure 12 A and Figure 12 B, utilize ink-jet method that the light-emitting face 33 of light conductor 3 is formed the black liquid point 36A of separate or partial continuous near light-incident end 31 and with this light-incident end at a distance of the zone of the width D 1 of S '.As implementing the employed device of ink-jet method, can exemplify continuously the printer of DOD (drop as required) mode of (continuous injection) mode and use pressurized nozzles.By utilizing said apparatus, spray black liquid from a plurality of nozzles, light conductor 3 is scanned on the required direction parallel at this nozzle as required, be formed with separate a plurality of black liquid point 36A as shown in the figure in the regulation zone of light-emitting face with light-emitting face 33.The adjacent part of above-mentioned black liquid point to each other also can be separate fully as shown in the figure, but also wherein a part is local overlapping continuous.

The adjacent part that then makes black liquid point to each other in conjunction with and form continuous black liquid layer (below be called " leveling ").By implementing to be somebody's turn to do " leveling " in order to reach the required time of desirable leveling amount (degree).Thus, shown in Figure 13 A and Figure 13 B, make the adjacent part combination to each other of black liquid point, to forming continuous black liquid layer 36b at a distance of the whole zone of the width D 2 of S with light-incident end 31.The zone of this width D 2 comprises the whole zone of above-mentioned width D 1, reaches bigger slightly than width D 1 by " leveling ".

Then, black liquid layer 36B forms optical absorption band 36 by being hardened.

Use for example ultraviolet hardening China ink liquid as black liquid.Ultraviolet hardening China ink liquid can be easy to realize required leveling amount (degree) by the control to ultraviolet irradiation time, therefore is fit to use.And, for easy control is used to obtain the time of required leveling amount, therefore preferably the temperature Jimo liquid temp of black nozzle for liquid is maintained and immobilizes.And, by light conductor 3 is heated, also can reduce the viscosity of the black liquid point 36A after the black liquid ejection such as ink droplet, can shortening obtain the required used time of leveling amount thus, shorten the time of printshop need.

Can utilize the leveling time that the bonding state of the black liquid point of black liquid layer 36B is controlled to be desirable state by carrying out as mentioned above, the surface state of controlling optical absorption band 36 be concavo-convex degree.Be pre-formed suitable concavo-convexly by surface, can make unwanted light more not obvious this optical absorption band 36.Specifically, make as mentioned above light that main light source 1 sends wherein a part reflect by light source reflector 22, be not to arrive light-incident end 31 but when arriving optical absorption band 36, wherein most partly be absorbed.At this moment, residue light reflexes to light conductor light-emitting face 33, but can utilize optical absorption band 36 surfaces concavo-convexly come this reverberation of scattered reflection so that unshowy.

The printer that resolution is high can more approaching black liquid be put and formed, and can shorten black liquid point in conjunction with the required leveling time, and is therefore comparatively desirable.

Other manufacture method examples of aforesaid light conductor are described with Figure 14 A, Figure 14 B, Figure 14 C and Figure 14 D below.

In this example, at first prepare the light conductor material 3 ' shown in Figure 14 A.Then, as shown in Figure 14B, light-incident end correspondence portion 31 ' is carried out machining, form light-incident end 31.Utilize this machining, both borders of light-incident end 31 and light-emitting face 33 are formed with (being that light-emitting face 33 is outstanding with respect to other the regional protuberances) protuberance 39 that projects to light-emitting face 33 directions.This protuberance 39 promptly extends along light-incident end 31 along both boundary lines of light-incident end 31 and light-emitting face 33.This protuberance 39 also can form by machining as mentioned above, but also can form by moulding when ejection formation.

Then, shown in Figure 14 C, the desired zone of light-emitting face 33 is formed black liquid point 36A.The formation of this China ink liquid point is carried out as illustrated at above-mentioned Figure 12 A and Figure 12 B.Then, carry out the leveling of black liquid point, shown in Figure 14 D, the desired zone of light-emitting face 33 is formed black liquid layer 36B.The formation of this China ink liquid layer 36B is carried out as illustrated at above-mentioned Figure 13 A and Figure 13 B, but the set positions that black liquid point is formed the zone here arrives protuberance 39 for its lateral margin near light-incident end 31 of black liquid layer 36B that forms by leveling.That is to say that light-incident end 31 is only left little by little in the formation zone of the black liquid point 36A shown in Figure 14 C.Thus, the black liquid that can utilize protuberance 39 to stop black liquid to be flowed at ordinary times o'clock sharp moves to light-incident end 31.

By being solidified, black liquid layer 36B forms optical absorption band 36 at last.

Utilize above method just under the situation that does not reach light-incident end 31, extremely to form optical absorption band 36 easily near this light-incident end 31.Utilize this optical absorption band 36 just can suppress to be incident to the minimizing of the light quantity of light conductor 3 from light-incident end 31.

In order to utilize this protuberance 39 to make black liquid be hampered by this function well in the appropriate location that moves to light-incident end 31, and form protuberance 39 easily, the size of protuberance 39 preferably adopts proper range as described below.Specifically, as shown in figure 18, H is 1～50 micron and is advisable, more satisfactory is 2～30 microns, and even more ideal is 5～20 microns, and W ' is advisable with 1～50 micron, more satisfactory is 2～30 microns, even more ideal is 5～20 microns, and wherein H is the height (with respect to light-emitting face 33 other regional height) of protuberance 39, and W ' is the halfwidth of height of the XZ end surface shape of protuberance 39.The protuberance height H is too small, and the effect that often stops black liquid to move is abundant inadequately, and the protuberance height H is excessive, and then often the planar light source device assembling is difficult, or breach takes place protuberance easily, even is difficult to make black liquid to move near the top of protuberance.And, the too small words of halfwidth W ' of height, often protuberance is formed with difficulty, and mechanical strength is low, the effect that stops black liquid to move is unreliable, and the halfwidth W ' of height is excessive, and then often the planar light source device assembling is difficult, and is difficult to make black liquid to move near the top of protuberance.

More than in Shuo Ming any method, the coating material that forms optical absorption band 36 usefulness is a ultraviolet hardening China ink liquid, wishes to use the ultraviolet hardening China ink liquid that contains (methyl) acrylate monomer and/or organic solvent.This is because help the adhesion raising that black liquid layer solidifies formed optical absorption band 36 and light conductor 3 surfaces.Owing to have organic solvent in the black liquid, make its chap that fixed effect is improved by the surface of melting light conductor 3.And particularly light conductor 3 uses under the situation of (methyl) acrylic resins owing to have (methyl) acrylate monomer in the black liquid, should China ink liquid during polymerization in the black liquid and light conductor cross-linking reaction takes place between the two easily, therefore can improve fixed effect.

The not bigger variation of above-mentioned (methyl) acrylate monomer, the preferably black liquid concentration of organic solvent, with count mean molecule quantity be 100 or more than be advisable, more satisfactory is 150 or more than, even more ideal is 200 or more than.(methyl) acrylate monomer is a methyl methacrylate for example, preferably contains for example 0.5～10 weight % in the black liquid.The not bigger variation of the preferably black liquid concentration of organic solvent, with 60 ℃ of boiling points or above being advisable, more satisfactory is 80 ℃ or more than, even more ideal is 100 ℃ or above solvent, and it is wherein at least a for example to comprise methyl ethyl ketone, ethyl acetate, chloroform, acetate methylcellulose, methacrylic acid.

Can exemplify the black liquid of composition as described below as this ultraviolet hardening China ink liquid.

China ink liquid 1

Acrylic acid oligomer: 30～50 weight %

Acrylic acid isoborneol: 10～20 weight %

1,6-hexylene glycol acrylate: 1～20 weight %

Oxolane acrylate: 10～20 weight %

Benzophenone: 1～5 weight %

Carbon black: 1～5 weight %

China ink liquid 2

Acrylic acid isoborneol: 10～20 weight %

1,6-hexylene glycol acrylate: 1～20 weight %

Acrylic amine/acrylate mixture: 30～50 weight %

Benzophenone: 1～5 weight %

Carbon black: 1～5 weight %

Among the present invention, utilize ink-jet method etc. to form under the situation of optical absorption band, as this ultraviolet hardening China ink liquid, when being suitable for using the ejection of black liquid under nozzle temperature black fluid viscosity be that 1～100cp, surface tension are the black liquid of 20～55mN/m, the more satisfactory black fluid viscosity that is to use is that 1～50cp, surface tension are the black liquid of 20～45mN/m, and the even more ideal black fluid viscosity that is to use is that 1～20cp, surface tension are the black liquid of 25～35mN/m.In addition, for the leveling performance of black liquid point, with the considerations such as stability of the correct coating position of the performance of combining closely of light conductor, the black liquid of ejection, nozzle temperature is advisable with 10～100 ℃, and more satisfactory is 30～85 ℃ of scopes, and even more ideal is 40～60 ℃ of scopes.

And, utilize ink-jet method etc. to form under the situation of optical absorption band, for pitch time shorten, the leveling of ink dot, with the considerations such as combining closely property of light conductor, spray head speed is advisable with 10～1000mm/ second, more satisfactory is 200～800mm/ second, and even more ideal is 250～500mm/ scope second.

Among the present invention, optical absorption band 36 can use the material that contains light diffusing or light absorption particulate.The particle diameter of this particulate with 20 microns or below be advisable, more satisfactory is 14 microns or below, it is desirable to especially 8 microns or below.This particulate can contain 10～125 weight % with respect to 100 weight of the coating material solid constituent except this particulate.The particulate of light absorption can be that black polymers such as the acrylic resin that for example contains carbon black etc., vinyl, (methyl) acrylic acid/ethylene copolymer, benzoguanamine resin are formed particulates such as particulate.And the light diffusing particulate can be that for example polymer particles, silica, aluminium oxide, calcium carbonate etc. such as acrylic resin, vinyl, (methyl) acrylic acid/ethylene copolymer, silicones are inorganic is the formed particulate of particulate.The light diffusing particulate also can be based on the particulate of the light diffusion of surface reflection, also can be have light transmission, based on the particulate of the light diffusion of internal transmission anaclasis.The light absorption particulate has contribution to the raising of optical absorption band 36 light absorption, and the light diffusing particulate improves light absorption by carry out light diffusion in optical absorption band 36 indirectly, and the equalization that diffusion produced of the light that do not absorb institute's outgoing is had contribution.

Shown in Figure 15 is the embodiment of optical absorption band 36 that contains the particulate of light diffusing or light absorption.In this embodiment, the surface of optical absorption band 36 is formed with micro concavo-convex.This concavo-convex protuberance 37 utilizes the particulate 38 of the light diffusing that comprises in the optical absorption band 36 or light absorption to form.This is concavo-convex by making the particulate 38 that contains light diffusing or light absorption in the coating material that constitutes optical absorption band 36 in advance, and can follow films forms.Surface to optical absorption band 36 is pre-formed micro concavo-convex like this, can make unwanted light not remarkable more.Specifically, as mentioned above, utilizing the part in the middle of light source reflector 22 reflection main light source 1 light that send, is not to arrive light-incident end 31 but when arriving optical absorption band 36, wherein more than half part is absorbed.At this moment, residue light reflexes to light conductor light-emitting face 33, but can concavo-convexly make this reverberation scattered reflection by what utilize optical absorption band 36 surfaces, avoids remarkable.

Shown in Figure 16 is the light-emitting face 33 of light conductor 3 and the enlarged drawing of light-incident end 31 both boundary portion.The formed edge part of light-emitting face 33 and light-incident end 31 both borders, rectangular basically in the ideal case, but form curved surface often in the reality processing with slight curvature radius.Particularly utilize machining to form under the situation of light-incident end 31 as mentioned above, sometimes because processing makes the synthetic resin partial melting of light conductor material, the marginal portion on light-emitting face 33 and light-incident end 31 both borders becomes based on capillary curved surface.Prevent that for preventing bright line etc. brightness uniformity from reducing this consideration, the radius of curvature R of wishing this edge part be 50 microns or below.This be because, the radius of curvature R of this edge part is excessive, then remarkable from the light incident of edge part, this part plays a part as convex lens, unusual light is arranged probably from light conductor 3 outgoing, or the effect that makes optical absorption band 36 prevent that bright line from taking place reduces.The radius of curvature R of this marginal portion it is desirable to 10 microns or below, it is desirable to especially 5 microns or below.

Shown in Figure 17 is the enlarged drawing of light-emitting face 33 and light-incident end 31 both boundary portion when forming light-incident end 31 and optical absorption band 36 near the lateral margin of light-incident ends simultaneously by machining.Utilize surface tension to be formed with the curved surface (being equivalent to above-mentioned protuberance 39) of radius of curvature R in the marginal portion on light-emitting face 33 and light-incident end 31 both borders, the ora terminalis of optical absorption band 36 be in make the light conductor edge part wherein a part expose this position.The exposed division of this light conductor edge part constitutes light-incident end 31.

The present invention will be described to utilize embodiment below.

[embodiment 1-9, Comparative Examples 1-3]

With acrylic resin (the ァ Network リ ペ ッ ト [trade name] of Mitsubishi Rayon Co. Ltd.'s system), utilize injection forming method, make wherein that one side be an asperities, another side is that the prism of 100 ° of prism vertex angles, 15 microns of top front end radius of curvature, 50 microns of spacings is listed as the light conductor material that parallels this rectangular shape of continuously arranged prism pattern with minor face and be wedge-like.Utilize serigraphy on the asperities of the light conductor material that forms this prism pattern, to be coated with following black ink liquid by various width and form optical absorption band correspondence portion from the thicker long limit of wall thickness.In addition, use the same method when black ink liquid is printed in the clear acrylic plate of thickness 2mm by the size that can measure transmission of visible light, the transmission of visible light of ultraviolet hardening black ink liquid is 40%.

Black ink liquid:

Acrylic acid oligomer: 45 weight %

Acrylic acid isoborneol: 17 weight %

1,6-hexylene glycol acrylate: 15 weight %

Oxolane acrylate: 15 weight %

Benzophenone: 3 weight %

Carbon black: 5 weight %

Then, carry out machining by the light-incident end correspondence portion to the light conductor material, it is wherein a part of in interior not part, to obtain having the light conductor as the formed light-incident end of machining face that excision comprises optical absorption band correspondence portion.Light conductor forms that the wedge shape of 230mm * 290mm, thickness 2.2mm-0.7mm is tabular, and the radius of curvature R of marginal portion is 40 microns, and is as follows at a distance of its width of optical absorption band of 0 micron with light entrance face:

Embodiment 1-800 micron

Embodiment 2-700 micron

Embodiment 3-600 micron

Embodiment 4-500 micron

Embodiment 5-400 micron

Embodiment 6-300 micron

Embodiment 7-200 micron

Embodiment 8-150 micron

Embodiment 9-75 micron

Comparative Examples 1-20 micron

Comparative Examples 2-1500 micron

Comparative Examples 3-20 micron (light-incident end one side also forms the optical absorption band of 20 microns width continuously)

Cover cold-cathode tube along long limit with light source reflector (the silver-colored reflectance coating of beautiful smooth Co., Ltd. system), be configured to the limit (long limit) a pairing wherein side end face (end face of thickness 2.2mm side) of 290 microns of the length of light conductor in opposite directions.And its opposite side end face is puted up light scattered reflection film (E60 (trade name) of eastern レ Co., Ltd. system), with reflector plate be configured to prism row arrangement plane (back side) in opposite directions.Above formation is assembled in the framework.The peak-peak of its emergent light light distribution of this light conductor (in the XZ plane) is 70 ° with respect to the normal direction of light-emitting face, and halfwidth is 22.5 °.

On the other hand, it with refractive index 1.5064 acrylic acid series uv curing resin, making wherein, the radius of curvature of the prism facets of a side is 1000 microns this convex curve surface shapes, another prism facets is a flat shape, and spacing is that the prism that many prism row of 50 microns are provided with side by side continuously is listed as one of them the surperficial prismatic lens of polyester film that is formed at 125 microns of thickness.

The prismatic lens that obtains is placed as light-emitting face (asperities) side of prism row formation face towards above-mentioned light conductor, and the crest line of prism row is parallel with the light-incident end of light conductor, and the plane faceted pebble of each prism row is towards the light-incident end direction of light conductor.

Planar light source device for embodiment 1～9 that obtains as mentioned above and Comparative Examples 1～3, by the same terms main light source is lighted, under the situation of light-emitting area being observed with visual type, embodiment 1～9 situation almost significantly is not near bright line of light conductor light-incident end and the concealed wire in the viewing area, but Comparative Examples 1 situation can clearly be confirmed bright line near the light conductor light-incident end, and Comparative Examples 2 situations reduce with near brightness embodiment 1～9 situation is compared the light-incident end of knowing light conductor, and Comparative Examples 3 situations are compared the concealed wire of knowing in brightness reduction and the viewing area with embodiment 1～9 situation.

[embodiment 10]

Make the light conductor material similarly to Example 1.Light-incident end correspondence portion to the light conductor material carries out machining then, to obtain having the light conductor as the formed light-incident end of machining face.It is tabular that light conductor forms the wedge shape of 230mm * 290mm, thickness 2.2mm-0.7mm.Asperities to the light conductor material that forms this prism pattern, utilize ink-jet method following ultraviolet hardening black ink liquid to be carried out many drops, this width D shown in Figure 12 A and Figure 12 B 1 about 300 microns, the zone about 60 microns apart from S ' are formed the about 100 microns many separate black liquid point of diameter by following condition.By making black liquid point 5 times in second of leveling with this state, this width D shown in Figure 13 A and Figure 13 B 2 about 400 microns, the whole zone about 10 microns apart from S are formed continuous black liquid layer.At this moment, irradiation ultraviolet radiation solidifies black liquid layer, forms the roughly optical absorption band of linearity.

Ink-jet method:

Spray head speed: 400mm/ second

Nozzle temperature: 55 ℃

Utilize the mode of piezoelectric element force feed

Ultraviolet hardening black ink liquid (black liquid 95 weight %+ methyl methacrylates 5 weight %):

China ink liquid is formed:

Acrylic acid oligomer: 42 weight %

Acrylic acid isoborneol: 15 weight %

1,6-hexylene glycol acrylate: 20 weight %

Acrylic amine/acrylate mixture: 15 weight %

Benzophenone: 3 weight %

Carbon black: 5 weight %

China ink fluid viscosity (55 ℃): 10cp

China ink liquid surface tension (55 ℃): 30mN/m

In addition, use the same method when ultraviolet hardening black ink liquid is printed in the clear acrylic plate of thickness 2mm by the size that can measure transmission of visible light, the transmission of visible light of ultraviolet hardening black ink liquid is 20%.

The light conductor that obtains is made up with cold-cathode tube, light source reflector, light scattered reflection film and reflector plate similarly to Example 1, the formation that obtains thus is assembled in the framework.The peak-peak of the emergent light light distribution of this light conductor (in the XZ plane) is 70 ° with respect to the normal direction of light-emitting face, and halfwidth is 22.5 °.

The prismatic lens of making similarly to Example 1 is configured to light-emitting face (asperities) side of prism row formation face towards above-mentioned light conductor, the crest line of prism row parallels with the light-incident end of light conductor, and the plane faceted pebble of each prism row is towards the light-incident end direction of light conductor.

For the planar light source device that obtains as mentioned above, main light source is lighted, to observe with visual type under the situation of light-emitting area, bright line and the concealed wire in the viewing area near the light conductor light-incident end are nearly all not obvious.

[Comparative Examples 4]

Make the light conductor material identical with embodiment 1, the light-incident end correspondence portion to the light conductor material carries out machining then, obtains having the light conductor as the formed light-incident end of machining face.Do not form optical absorption band in this Comparative Examples.

The light conductor that obtains is made up with cold-cathode tube, light source reflector, light scattered reflection film and reflector plate similarly to Example 1, the formation that obtains thus is assembled in the framework.The peak-peak of the emergent light light distribution of this light conductor (in the XZ plane) is 70 ° with respect to the normal direction of light-emitting face, and halfwidth is 22.5 °.

The prismatic lens of making similarly to Example 1 is configured to light-emitting face (asperities) side of prism row formation face towards above-mentioned light conductor, the crest line of prism row parallels with the light-incident end of light conductor, and the plane faceted pebble of each prism row is towards the light-incident end direction of light conductor.

For the planar light source device that obtains as mentioned above, under the condition identical, main light source is lighted with embodiment 10, observe with visual type under the situation of light-emitting area, can clearly confirm near the bright line the light-incident end of light conductor.

[embodiment 11]

Make the light conductor material similarly to Example 1.Light-incident end correspondence portion to the light conductor material carries out machining then, to obtain having the light conductor as the formed light-incident end of machining face.It is tabular that light conductor forms the wedge shape of 230mm * 290mm, thickness 2.2mm-0.7mm.Asperities to the light conductor material that forms this prism pattern, utilize ink-jet method that ultraviolet hardening black ink liquid is carried out many drops similarly to Example 10, this width D shown in Figure 12 A and Figure 12 B 1 about 300 microns, the zone about 60 microns apart from S ' are formed the about 100 microns many black liquid point of diameter.Soon be that irradiation ultraviolet radiation makes black liquid point sclerosis to avoid making black liquid point leveling, form the roughly optical absorption band of linearity thereafter.Its each black liquid point of this absorption band is in separate position, and width is about 300 microns, about 60 microns apart from light-incident end.

In addition, use the same method when ultraviolet hardening black ink liquid is printed in the clear acrylic plate of thickness 2mm by the size that can measure transmission of visible light, the transmission of visible light of ultraviolet hardening black ink liquid is 20%.

Similarly to Example 1, light conductor and cold-cathode tube, light source reflector, light scattered reflection film and the reflector plate that obtains made up, the formation that obtains thus is assembled in the framework.The peak-peak of the emergent light light distribution of this light conductor (in the XZ plane) is 70 ° with respect to the normal direction of light-emitting face, and halfwidth is 22.5 °.

The prismatic lens of making similarly to Example 1 is configured to light-emitting face (asperities) side of prism row formation face towards above-mentioned light conductor, the crest line of prism row parallels with the light-incident end of light conductor, and the plane faceted pebble of each prism row is towards the light-incident end direction of light conductor.

For the planar light source device that obtains as mentioned above, under the condition identical with embodiment 10, main light source is lighted, observe with visual type under the situation of light-emitting area, can find that specific luminance is low slightly mutually with embodiment 10 situations, and some bright lines are arranged near the light conductor light-incident end.

[embodiment 12]

Similarly to Example 10, the light-incident end correspondence portion of light conductor material is carried out machining, obtain having light conductor as the formed light-incident end of machining face.Utilize machining to be formed with the protuberance of giving prominence to respect to other zone protuberances of light-emitting face (protuberance) on the border of light-incident end and light-emitting face.This protuberance height is 10 microns, and halfwidth is 10 microns.Similarly to Example 10, form black liquid layer by forming black liquid point and it being flattened.But the position in the formation zone of above-mentioned black liquid point is set at black liquid layer by leveling and arrives protuberance.

For with resulting light conductor and the embodiment 10 identical planar light source devices that obtain, main light source is lighted, observe with visual type under the situation of light-emitting area, can find almost significantly not to be near the light-incident end of light conductor bright line and the concealed wire in the viewing area.

Claims (19)

1. planar light source device light conductor, it is characterized in that, light that main light source sends is carried out leaded light, and have and allow described main light source send the light-incident end of light incident and allow by the light-emitting face of the light outgoing of leaded light, be formed with the width that extends along described light-incident end on the described light-emitting face and be 50 microns～1000 microns optical absorption band, this optical absorption band near the lateral margin of described light-incident end be distance from described light-incident end be 300 microns or below.

2. planar light source device light conductor as claimed in claim 1 is characterized in that described optical absorption band forms, and compares with the lateral margin near described light-incident end, and the transmission of visible light of lateral margin far away is higher.

3. planar light source device light conductor as claimed in claim 1 is characterized in that, is formed with fine concavo-convex on the surface of described optical absorption band.

4. planar light source device light conductor as claimed in claim 1 is characterized in that, its radius of curvature of marginal portion that forms the border of described light-emitting face and described light-incident end be 50 microns or below.

5. planar light source device light conductor as claimed in claim 1, it is characterized in that, the marginal portion that forms the border of described light-emitting face and described light-incident end forms the protuberance that swells with respect to other zones of described light-emitting face along described light-incident end, and described protuberance is 1～50 micron from the height of described light-emitting face.

6. planar light source device light conductor as claimed in claim 1, it is characterized in that, the marginal portion that forms the border of described light-emitting face and described light-incident end forms the protuberance that swells with respect to other zones of described light-emitting face along described light-incident end, and its halfwidth of described protuberance is 1～50 micron.

7. a planar light source device is with the manufacture method of light conductor, it is characterized in that, being included in the light-emitting face correspondence portion of light conductor material at least, the zone near light-incident end correspondence portion forms optical absorption band correspondence portion, after this described light-incident end correspondence portion is carried out machining, form the operation of described light-incident end.

8. planar light source device as claimed in claim 7 is characterized in that with the manufacture method of light conductor, forms described optical absorption band correspondence portion by being coated with black liquid.

9. a planar light source device is with the manufacture method of light conductor, it is characterized in that, by utilizing ink-jet method to spray black liquid from a plurality of nozzles, it forms the black liquid point of separate or partial continuous at least near the zone of light-incident end at the light-emitting face of light conductor, then be bonded to each other by making this China ink liquid put its adjacent part, be formed on continuous black liquid layer in the whole described regional extent, after this form described optical absorption band by this China ink liquid layer is solidified.

10. planar light source device as claimed in claim 9 is characterized in that with the manufacture method of light conductor, the light-incident end correspondence portion of light conductor material carried out machining form described light-incident end, after this forms described optical absorption band.

11. the planar light source device as claimed in claim 10 manufacture method of light conductor, it is characterized in that, its lateral margin position near described light-incident end, described zone is set at described black liquid layer and arrives by described machining till the outstanding formed protuberance of described light-emitting face direction.

12. planar light source device is characterized in that with the manufacture method of light conductor as claimed in claim 8 or 9, described black liquid is the ultraviolet hardening China ink liquid that comprises (methyl) acrylate monomer and/or organic solvent.

13. planar light source device as claimed in claim 12 is characterized in that with the manufacture method of light conductor, described (methyl) acrylate monomer and/or organic solvent its count mean molecule quantity be 100 or more than.

14. planar light source device as claimed in claim 12 is characterized in that with the manufacture method of light conductor described (methyl) acrylate monomer is a methyl methacrylate.

15. planar light source device as claimed in claim 12 is characterized in that with the manufacture method of light conductor described (methyl) acrylate monomer contains 0.5～10 weight % in described black liquid.

16. planar light source device as claimed in claim 12 is characterized in that with the manufacture method of light conductor described organic solvent is that boiling point is 60 ℃ or above solvent.

17. planar light source device as claimed in claim 12 is characterized in that with the manufacture method of light conductor it is wherein at least a that described organic solvent comprises methyl ethyl ketone, ethyl acetate, chloroform, acetate methylcellulose and methacrylic acid.

18. a planar light source device is characterized in that, comprises as each described planar light source device light conductor in the claim 1～6; Described main light source with the described light-incident end disposed adjacent of this light conductor; And with the light deflection element of the light-emitting face disposed adjacent of described light conductor, this light deflection element has and is in that the light receiving surface of position and the photoconduction of its opposition side are appeared in opposite directions with the light-emitting face of described light conductor, on the light receiving surface of described light deflection element, have with the light-incident end almost parallel direction of described light conductor on a plurality of prisms row of extending and being parallel to each other.

19. planar light source device as claimed in claim 18, it is characterized in that, with the photoconduction of the described light deflection element disposed adjacent of appearing light diffusion element is arranged, this light diffusion element has dot pattern portion, this dot pattern portion forms the light absorption dot pattern in light-incident end 2mm position to the zone of the width of 4mm position of described light conductor comprising at least, and this dot pattern portion is that the decentralized configuration diameter is that 30 microns～70 microns the light absorption coating material of point-like is formed.

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