CN101061347A - Light guide plate - Google Patents
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- CN101061347A CN101061347A CNA2005800395096A CN200580039509A CN101061347A CN 101061347 A CN101061347 A CN 101061347A CN A2005800395096 A CNA2005800395096 A CN A2005800395096A CN 200580039509 A CN200580039509 A CN 200580039509A CN 101061347 A CN101061347 A CN 101061347A
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Abstract
A light guide plate (1) formed in a plate shape having a plane of incidence (5) on its side face and a plane of outgoing (3) on its upper or lower face. Polarizing pattern elements (17) of roughly quadrangular pyramid shape formed in a direction for reducing their wall thickness more than the wall thickness of the general wall thickness of the light guide plate (1) are arranged, adjacent to each other, on the surface thereof facing the plane of outgoing (3). The shape of the quadrangular pyramid is such that four faces thereof other than the bottom face are formed integrally with the light guide plate (1). The areas of the first and second faces of the four faces other than the bottom face are 20 times the areas of the other third or fourth face or larger, the ridge lines of the first and second faces perpendicularly crosses the plane of incidence (5), and the inclination angles of the first and second faces relative to the plane of outgoing (3) are within the range of 0.5 to 3 DEG . The areas of the first and second faces are approximately the same and the areas of the third and fourth faces are approximately the same to prevent the brightness of the areas thereof near the plane of incidence from increasing or decreasing.
Description
Technical field
The present invention relates to a kind of LGP in the back lighting device of back side illuminaton liquid crystal display cells etc. and back lighting device that possesses this LGP of being used in.
Background technology
All the time, for the liquid crystal indicator to portable phone etc. throws light on, provide the light that will penetrate to import the LGP of liquid crystal indicator and the back lighting device that has this LGP and liquid crystal indicator is thrown light on from the back side from light source.
Fig. 1 represents the schematic diagram of liquid crystal indicator 10 outward appearances.In Fig. 1,1 is that LGP, 2 is that light source, 3 is that exit facet, 4 is that reflecting surface, 5 is that the plane of incidence, 6 is that deflection graphic elements, 7 is that liquid crystal panel, 8 is that speculum, 9 is that optical sheet, 11 is that (holder), 12 is observer's viewpoint for light, 13.Moreover, from liquid crystal indicator 10, remove after the liquid crystal panel, then be back lighting device 14.
LGP 1 for example can be made of transparent materials such as PMMA or Merlon, and has roughly tabular even shape.And as the plane of incidence 5, reflecting surface 4 is formed with the deflection figure that is made of a plurality of deflection graphic elements 6 with a side, is used for the light from the plane of incidence 5 incidents is reflected or deflections to exit facet 3.LGP 1 is disposed at liquid crystal panel 7 belows, the exit facet 3 of LGP 1 and the lower surface arranged opposite of liquid crystal panel 7.The light 12 that penetrates from light source 2 is incident to LGP 1 and enters the inside of LGP 1 from the plane of incidence 5, and by the deflection graphic elements 6 that on reflecting surface 4, forms towards the direction of exit facet 3, and penetrate from exit facet 3.So, will be called side direction (side edge) light inlet mode from the LGP 1 that the exit facet 3 that is positioned at interarea penetrates, be widely used in the portable phone etc. No. the 3151830th, Japan Patent (for example with reference to) from the light of the plane of incidence 5 incidents that are positioned at the side.
Yet, in the prior art, providing a kind of laser that makes makes photosensitive film exposure, irregularly forms the hologram (hologram) that forms behind a plurality of hot spots (speckle) (for example with reference to United States Patent (USP) the 5th by the rectangular aperture with diffuser (diffuser), 365, No. 354 communiques and United States Patent (USP) the 5th, 534, No. 386 communiques).In this hologram, hot spot has slightly oval shape, has the relation of Fourier transform between the rectangle minor face of long axis of ellipse and minor axis and opening and the long limit.If inject laser to this hologram, then scattering can take place because of each hot spot in laser, and reproduces employed rectangular-shaped opening when exposing.By using such hologram, incident light is anisotropically spread.
In existing LGP, the deflection graphic elements is generally the dot pattern 15 (dotpattern) shown in Fig. 2 (a).Yet have following problem, because the deflection graphic elements is an ellipse figure independently, so shown in Fig. 2 (b), utilizing the light that the deflection graphic elements is reflected not is to penetrate to fixed-direction, its result is, emergent light diffusion and be difficult to improve brightness.
Therefore, in recent years, reduce for preventing so brightness, the LGP of the deflection graphic elements that applying shown in Fig. 3 (a) roughly is V-shape becomes main flow.In general, the deflection graphic elements of this V-shaped valley type is made as the direction of above-mentioned V-shaped valley parallel with the plane of incidence shown in the vertical view of Fig. 3 (b).
This mode as shown in Figure 4 because emergent ray 12 arrangement of relatively align, so by with the optical sheet 9 of the upper surface abut of LGP 1, the frontals that can effectively light 12 be led, and can realize high brightnessization.
Yet there is following difficult point in the situation of this structure, is easy to generate the dark portion 16 shown in Fig. 5 (a) near the incidence surface of light source 2.Its reason utilizes Fig. 5 (b) to be illustrated.Fig. 5 (b) is a side view of observing Fig. 5 (a) from light source 2 directions.From the light of light source 2 in the plane of incidence 5 is injected LGP 1.As existing LGP, when reflection groove was straight line, the ray trajectory of the light 12a from the light that light source 2 penetrates became by the prismatic film above being disposed at 10 (prism film) and deflects from frontal.Yet, deflection ground is bigger by the reflecting surface of linearity for light 12b (oblique light), owing to break away from the ray trajectory that can deflect from frontal by prismatic film 10, so there is following problem, promptly produce the less part of exit dose of light, and this part is dark portion when observing.
Summary of the invention
The present invention In view of the foregoing proposes, and purpose is to provide a kind of near the LGP of the brightness light and shade that the plane of incidence is and back lighting device with this LGP of preventing.
The present invention is by forming the reflection groove that roughly is quadrangular pyramid on LGP, and by disposing the deflection of superincumbent prismatic film, can be convenient to the ray trajectory of light 12a, 12b is together imported frontal, thereby the defective that can prevent V-shaped valley is near the brightness light and shade of the plane of incidence.
Embodiments of the present invention are to have the plane of incidence in the side, have the tabular LGP of exit facet at upper surface or lower surface, above-mentioned exit facet or with opposed of above-mentioned exit facet on be arranged with a plurality of deflection graphic elements; This deflection graphic elements has quadrangle cone shape, and four faces beyond its quadrangular pyramid bottom surface are integrally formed on this LGP; The 1st adjacent area separately in above-mentioned four faces with the 2nd be adjacent the 3rd with the 4th more than 10 times of area separately; Above-mentioned the 1st relative above-mentioned exit facet with above-mentioned the 2nd inclination angle separately is 0.5～3 °.
In addition, the preferably above-mentioned deflection graphic elements of another embodiment of the present invention is quadrangle cone shape to be arranged with (depressed) in LGP.
In addition, another embodiment of the present invention preferably is roughly the spacing P of the deflection graphic elements of quadrangular pyramid shape
SFixing.
In addition, another embodiment of the present invention preferably is roughly the spacing P of the deflection graphic elements of quadrangular pyramid shape
SIndefinite.
The bottom surface of the quadrangular pyramid shape of preferably above-mentioned deflection graphic elements is a parallelogram.
In addition, the preferably limit and the formed angle θ of the plane of incidence of above-mentioned parallelogram of another embodiment of the present invention
RAnd θ
LBe respectively above 0 and below 60 °.
In addition, the preferably above-mentioned θ of another embodiment of the present invention
LWith above-mentioned θ
RAngle is identical.
In addition, one side another embodiment of the present invention being in line of one group of parallel both sides in four limits of above-mentioned parallelogram and adjacent parallelogram preferably.
In addition, one side another embodiment of the present invention preferably four limits of above-mentioned parallelogram each limit respectively with being in line of adjacent parallelogram.
In addition, another embodiment of the present invention preferably becomes θ with incidence surface
LThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
L(1), P
L(2) ... P
L(m), and with incidence surface become θ
RThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
R(1), P
R(2) ... P
R(n) time, P
L(m) and P
R(n) all be identical value.
In addition, another embodiment of the present invention preferably becomes θ with incidence surface
LThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
L(1), P
L(2) ... P
L(m), and with incidence surface become θ
RThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
R(1), P
R(2) ... P
R(n) time, P
L(m) and P
R(n) numerical value is to be set at random number.
In addition, the preferably above-mentioned P of another embodiment of the present invention
LAnd above-mentioned P
RSatisfy P
L(1)=P
R(1), P
L(2)=P
R(2) ... P
L(n)=P
R(n) relation.
In addition, the preferably above-mentioned P of another embodiment of the present invention
LAnd above-mentioned P
RMedian be respectively 30～500 μ m.
In addition, another embodiment of the present invention preferably the scope of above-mentioned random number be above-mentioned median ± 15% or ± 20 μ m.
In addition, preferably above-mentioned the 1st and above-mentioned the 2nd formed crest line of another embodiment of the present invention and the angle that normal became of the above-mentioned plane of incidence are in ± 40 °.
In addition, the preferably above-mentioned deflection graphic elements of another embodiment of the present invention be formed at opposed of above-mentioned exit facet on, and on exit facet, be formed with other optical element.
In addition, preferably above-mentioned other optical element of another embodiment of the present invention has the function of diffusion or optically focused emergent light.
In addition, preferably above-mentioned other optical element of another embodiment of the present invention has each to different diffusion property.
In addition, another embodiment of the present invention preferably has the back lighting device and the liquid crystal indicator of above-mentioned LGP.
In addition, relate to LGP of the present invention and preferably have the plane of incidence in the side, the tabular LGP that has exit facet at upper surface or lower surface, with opposed of above-mentioned exit facet on the adjacent rows deflection graphic elements showing roughly to be quadrangular pyramid, this deflection graphic elements is formed on the direction of general wall thickness attenuation of LGP, the four sides in addition, quadrangular pyramid bottom surface that is shaped as of this quadrangular pyramid is integrally formed on the LGP, and the 1st area with the 2nd in the four sides beyond the bottom surface is respectively other the 3rd or the 4th 's more than 20 times of area, above-mentioned the 1st with the 2nd crest line and plane of incidence quadrature, the inclination angle of above-mentioned the 1st and the 2nd above-mentioned relatively exit facet is in the scope of 0.5～3 degree, above-mentioned the 1st face with the 2nd is roughly the same area, and above-mentioned the 3rd face with the 4th is roughly the same area.Here the roughly the same area of indication is meant in the median of two areas ± 10%.
Preferably at the integrally formed surface fluctuation type hologram of exit facet side.
The spacing that preferably roughly is the deflection graphic elements of quadrangular pyramid is fixed.
The spacing of deflection graphic elements that preferably roughly is quadrangular pyramid is indefinite.
Preferably the hologram of above-mentioned surface fluctuation type have with the direction of plane of incidence quadrature on be a plurality of random spot area of long wire.
Preferably the light diffusion property of the hologram of above-mentioned surface fluctuation type is for carrying out abnormity diffusion at the half-value angles that are parallel on the direction of the plane of incidence with 30～70 degree, and carries out abnormity with the half-value angle of 0.5～3 degree on perpendicular to the direction of the plane of incidence and spread.
Back lighting device of the present invention possesses the LGP of said structure.
According to the present invention, can solve LGP and possess near the plane of incidence in the back lighting device of LGP the problem of light and shade.
Description of drawings
Fig. 1 is the concept map of the existing LGP of expression.
Fig. 2 is the figure of the user mode of existing LGP of expression and back lighting device.
Fig. 3 is the concept map of the deflection graphic elements of employed dot pattern in the existing LGP of expression.
Fig. 4 is the LGP that applies existing V-shape reflection groove.
Fig. 5 is the figure of configuration prismatic film on existing LGP.
Fig. 6 is the concept map that is used to illustrate existing LGP light and shade.
Fig. 7 is the concept map that is used to illustrate LGP of the present invention, (a) is the vertical view of LGP, (b) is the front view of LGP, (c) is the stereogram of LGP.
Fig. 8 is the LGP that is concaved with the deflection graphic elements.
Fig. 9 is the LGP that convexes with the deflection graphic elements.
Figure 10 is existing straight line V-shape reflection groove mode of expression and the concept map that contains the LGP of deflection graphic elements.
Figure 11 is a LGP of the present invention.
Figure 12 is the concept map of the 1st effect of expression LGP of the present invention.
Figure 13 is the figure at the interval of deflection graphic elements in the explanation LGP of the present invention.
Figure 14 is the enlarged drawing that expression is formed at the details of the hologram on the exit facet.
Figure 15 is the vertical view of the 3rd embodiment of expression LGP of the present invention.
Figure 16 is the enlarged drawing that expression is formed at the details of the hologram on the exit facet.
Figure 17 is the skeleton diagram of an example that the back lighting device of LGP of the present invention has been used in expression.
Figure 18 is the figure of the effect of explanation hologram.
Figure 19 is the figure that expression outgoing light intensity distributes.
Figure 20 is the figure of a part that expression has the back lighting device (perhaps planar light source device) of LGP and optical sheet.
Figure 21 is the figure that expression outgoing light intensity distributes.
Figure 22 is the figure of the part of expression back lighting device.
The specific embodiment
Below, described in detail with reference to the embodiment of accompanying drawing LGP of the present invention and back lighting device.In the present embodiment, for asking simple, and in several different accompanying drawings, use common designated symbol to represent for same parts.In addition, the accompanying drawing in the present embodiment is used to illustrate content of the present invention, and is not the ratio that correctly reflects the each several part size.In addition, for ease of reference, be provided with xyz quadrature coordinate system among the figure.That is, be set at x axle and y axle along the upper surface of LGP or 2 limits of lower surface, will be from the incident direction of the light of light source as the x axle, with perpendicular direction as the y axle.In addition, the normal direction of exit facet is set at the z axle.In addition, about the positive negative direction of z axle is called.
(the 1st embodiment)
Fig. 6 is the stereogram of the 1st embodiment of expression LGP of the present invention.Among Fig. 6, for ease of understanding, to scheme a kind of mode of expression as the configuration of light-emittingdiode (LED), optical sheet (prismatic lens) 6 and the liquid crystal panel 7 of light source 2.LGP 1 has the plate-like shape of roughly rectangular upper surface and lower surface, and have the plane of incidence 5 that makes from the light incident of light source 2, exit facet 3 that light is penetrated upward and reflection be from the incident light of the plane of incidence 5 or from the catoptrical reflecting surface 4 of exit facet 3.
As the material that constitutes LGP 1, do not do special restriction so long as have the transparent material of fixed refraction, for example, can enumerate PMMA, polyolefin or Merlon etc.In addition, the size of LGP 1 is according to purposes and difference, but if the large-scale purposes of 12 or 14 inches displays etc., its size is that 182.9 * 243.8mm～213.4 * 284.5mm is if the medium-sized purposes of 3 or 8 inches displays etc., its size is 45.7 * 81.0mm～121.9 * 162.6mm if the small-sized purposes of 1 or 2.8 inch display etc., and its size is about 15.2 * 20.3mm～42.7 * 56.9mm.In addition, thickness is generally 0.04mm～56.9mm.
The plane of incidence 5 is located at a side of LGP, can be efficiently to LGP 1 incident from the light of light source 2.The plane of incidence 5 mostly is the plane, as shown in Figure 6, also can form a plurality of thin linear grooves.So, better aspect the brightness disproportionation that improves the incident section.In addition, the processing that is formed on the plane of incidence 5 is not limited to linear grooves, can implement existing well-known processing as required.
Be arranged with deflection graphic elements 17 shapes that roughly are quadrangular pyramid on reflecting surface 4 continuously, 4 faces beyond the quadrangular pyramid bottom surface of this deflection graphic elements 17 are formed on the LGP.Fig. 7 is the figure of a shape of expression deflection graphic elements 17.In addition, in Fig. 7, Fig. 7 (a) is the stereogram of deflection graphic elements 17, and Fig. 7 (b) is the profile of VIIb-VIIb, and Fig. 7 (c) is the profile of VIIc-VIIc.
The 1st 17a that the area of deflection graphic elements 17 is bigger and the 2nd 17b are mainly with acting on the lead reflecting surface of exit facet 3 directions of LGP 1 of incident light.Herein, the area of the 1st 17a that area is bigger and the 2nd 17b preferably is respectively other the 3rd 17c and more than 20 times of area of the 4th 17d.In addition, the area of the 1st 17a and the 2nd 17b is preferably roughly the same, and the area of the 3rd 17c and 4 17d of the mat woven of fine bamboo strips is also preferably roughly the same.
Therefore, formed reflecting surface 4, can improve, and improved the light utilization ratio of LGP 1 light of institute's incident efficient to the reflection of exit facet 3 directions as the deflection graphic elements 17 of present embodiment.And the deflection graphic elements 17 of quadrangular pyramid is arranged as, the crest line 18 of the 1st 17a and the 2nd 17b towards with the direction (X-direction) of the plane of incidence 5 quadratures.
In addition, in LGP of the present invention, the 1st 17a in the deflection graphic elements 17 and the inclination angle separately of the 2nd 17b (inclination of exit facet relatively) is less than the inclination angle separately of above-mentioned the 3rd 17c and the 4th 17d.So the area of deflection graphic elements 17 bigger the 1st and the 2nd 17a, 17b mainly are with acting on the lead reflecting surface of exit facet 3 directions of LGP 1 of incident light.Herein, the 1st 17a that area is bigger and the area of the 2nd 17b are respectively other the 3rd 17c and more than 10 times of area of the 4th 17d, better are more than 15 times, are more preferably more than 20 times.In addition, preferably the area of 1 17a of the mat woven of fine bamboo strips of adjacency and the 2nd 17b is roughly the same, and the 3rd 17c of adjacency and the area of the 4th 17d are also roughly the same.Herein, the roughly the same difference of area that is meant of so-called area is in 2 times.
LGP of the present invention has the deflection figure, and this deflection figure is made of four faces beyond the bottom surface of quadrangular pyramid, to this, above explains.Yet the formation method of four faces beyond the quadrangular pyramid bottom surface has two kinds, that is, this kind LGP also has two kinds.A kind of method is the quadrangular pyramid of putting upside down among Fig. 7 (a), pushes to LGP, thus the method for formation deflection figure.Thus, then can obtain Fig. 7 (a) quadrangle cone shape is arranged with the LGP of shape shown in (depressed) Fig. 8 on LGP.Another kind method is directly the quadrangle cone shape of Fig. 7 (a) in statu quo to be arranged with a plurality of methods on LGP, like this, can obtain the LGP of shape as shown in Figure 9.
Any LGP, all by dispose area bigger the 1st 17a and the 2nd 17b in mode towards light source direction, thereby can make light from light source incident to the deflection of exit facet direction, but with regard to the easness or optical characteristics aspect of manufacture method, quadrangle cone shape is arranged with (depressed) LGP on LGP and has advantage.
So, in the LGP 1 that has formed as the deflection graphic elements 17 of present embodiment, can improve the light of the institute's incident efficient to the reflection of observer's direction, the result can improve the light utilization ratio.
Figure 10 is the vertical view of LGP of expression the 1st embodiment of the present invention, and the deflection graphic elements 17 of quadrangular pyramid is arranged as, the crest line 18 of the 1st 17a and the 2nd 17b towards with the direction (x direction of principal axis) of the plane of incidence 5 quadratures.So, crest line 18 alignment is arranged on the direction (x direction of principal axis) with the plane of incidence 5 quadratures, so the extension shape of each deflection graphic elements 17 (shape of quadrangular pyramid bottom surface) becomes rhombus.
Among Figure 10, LGP 1 left side spacing (pitch) (becomes θ with incidence surface
LThe straight line group's of angle spacing) is expressed as P
L(1), P
L(2) ... P
L(m), LGP 1 right side spacing (becomes θ with incidence surface
RThe straight line group's of angle spacing) is expressed as P
R(1), P
R(2) ... P
R(n), all P
LFor uniformly-spaced, all P
RFor uniformly-spaced, and P
LWith P
RValue equate.Among Figure 10, (m, n), herein, (m, n) no matter how many equal diamondwise shapes m and n are to P to be expressed as P by m spacing and n formed deflection graphic elements of spacing.
In the 1st embodiment, the interval (P among aftermentioned Figure 12 that adjacent deflection graphic elements is 17
S) fixing.P
SValue, better be 30～500 μ m, be more preferably 100～200 μ m, preferred 120～160 μ m.Have again, 4 of the exit facet 3 of LGP 1 and reflectings surface apart from a (thickness of LGP), better be 0.3～3.0mm, be more preferably 0.35～0.8mm, preferred 0.4～0.8mm.
Among Figure 10, the rhombus limit of deflection graphic elements and y axle angulation (θ
LWith θ
R) there is not restriction especially, but with regard to the utilization ratio aspect of light, better be 0～60 °, be more preferably 5～40 °, preferred 5～20 °.In addition, as P
R, P
L, with regard to the outward appearance aspect of the machining hole of metal die, better be 30～500 μ m, be more preferably 100～200 μ m, preferred 120～160 μ m.
Figure 11 represents the profile of the part of XI-XI section among Figure 10.As shown in the drawing, deflection graphic elements 17 has reflecting surface i.e. the 1st 17a and the 2nd 17b and the 3rd 17c and the 4th 17d that roughly is the quadrangular pyramid shape towards light source, and the 1st 17a and the 2nd 17b opposing parallel have certain angle alpha in the mask of exit facet 3
1(angle of inclination).According to Figure 11 as can be known, the 1st and the 2nd 17a, 17b can make and upwards advance with the light of exit facet 3 angled φ 1 incidents, and make light become φ 2 with the angle of exit facet 3.That is,, when the 1st 17a and the 2nd 17b incident, can reduce and the formed angle of above-mentioned normal for the normal of exit facet 3 light with certain angle incident at every turn.And, if the formed angle of normal of light of upwards advancing gradually and exit facet 3 less than critical angle, then penetrates from exit facet 3.That is, the light of injecting to the plane of incidence 5 of LGP 1 from light source 2 enters LGP 1 inside total reflection the time repeatedly with exit facet 3 and reflecting surface 4 till the angle that normal was with exit facet 3 reaches critical angle.
Above-mentioned the 1st and the 2nd 17a, 17b and be parallel to the face angulation α of exit facet 3
1Must be less than 3 of the above-mentioned mat woven of fine bamboo strips tilt angle alpha with the 4th
2, better be that its absolute value is also less.α
1More little, then light is by upwards advancing lentamente with the reflection of the 2nd 17a, 17b with the 1st, is generally and critical angle angle about equally from the angle of emergence (the formed angle of the normal of exit facet and emergent light) of the emergent light of exit facet 3.Therefore, the direction of light alignment of penetrating from exit facet 3 is arranged.Consider the 1st and the 2nd 17a, 17b and be parallel to the face angulation α of exit facet 3 from this viewpoint
1(angle of inclination) better is 0.5～3 degree, is more preferably 1～2.5 degree.
In addition, the 3rd with the 4th 17c, 17d and be parallel to face angulation (the 3rd with the 4th the angle of inclination) α of exit facet 3
2, owing to almost or all do not have above-mentioned reflex, so preferably big as far as possible.Yet the molding aspect when being shaped from being convenient to following LGP 1 is considered, better is below 90 degree.When obtaining above balance, better be α
2Be 50～90 degree, be more preferably 55～87 degree.
In addition, in the 1st embodiment, the interval P that adjacent deflection graphic elements is 17
SAs shown in figure 12 for fixing.As P
SValue, better be 30～500 μ m, be more preferably 100～200 μ m, preferred 120～160 μ m.Have, the exit facet 3 of LGP 1 better is 0.3～3.0mm with reflecting surface 4 apart from a (thickness of LGP), is more preferably 0.35～0.8mm, preferred 0.4～0.8mm again.
Then, not that other embodiment of rhombus is illustrated to bottom shape successively.Have again, about the tilt angle alpha of each face of deflection figure
1With α
2Scope, also identical in other embodiment of the present invention of following explanation.
(the 2nd embodiment)
Shown in the 1st embodiment, above-mentioned interval (spacing) P in Figure 12
SFor fixedly the time, by the interval of liquid crystal display cells pixel, the configuration of the unit of liquid crystal display cells ripple (moire) (interference fringe) can occur with the interference of LGP.This situation can be passed through the above-mentioned interval P of random setting wittingly
S, and eliminate or the minimizing ripple.
Figure 13 represents the random P of setting
SMethod.Figure 13 is that expression is observed with P from reflecting surface 4 sides
SVertical view for the manufactured LGP 1 of random mode.Among Figure 13, the left side spacing of LGP 1 is expressed as P
L(1), P
L(2) ... P
L(m), the right side spacing of LGP 1 is expressed as P
R(1), P
R(2) ... P
R(n), all P
L, P
RBe irregularly and set.
About P
R, P
LMedian (median of maximum and minimum of a value), consider from the outward appearance aspect of metal die machining hole, better be 30～500 μ m, be more preferably 100～200 μ m, preferred 120～160 μ m.In addition, as the scope of random number, be preferably in above-mentioned median ± 15% or ± 20 μ m in.In addition, there is no particular restriction for the tetragonal limit of deflection graphic elements and y axle angulation, but consider from the utilization ratio aspect of light, better is 0～60 °, is more preferably 5～40 °, preferred 5～20 °.
P
L, P
RValue irregularly determine, but also can be P
L(1)=P
R(1), P
L(2)=P
R(2), P
L(n)=P
R(n).So, when the processing LGP, disposable decision random number is preferable.Determine P like this
L, P
RThe LGP surface configuration of value shown in Figure 14 (a), (m, shape n) are rhombus in the part of m=n to deflection graphic elements P, the alignment of its crest line is arranged on the straight line, the part of m ≠ n be not rhombus but parallelogram and its crest line also not alignment be arranged on the straight line.
For example, the limit of parallelogram and y axle angulation are 10 °, P
R, P
LMedian be made as 140 μ m, the scope of random number is made as ± situation of 20 μ m, shown in Figure 14 (b), each deflection graphic elements is shaped as, and is 236～316 μ m at the y direction of principal axis, is 41～56 μ m at the x direction of principal axis, in addition, the angle φ of crest line is in ° scope of x axle ± 39.01.Preferably the angle of this crest line be ± 40 ° with interior scope.So, each deflection graphic elements shape has abundant no regularity, thereby can expect to eliminate or reduce ripple.
Usually, in this optics, if surface configuration has no regularity, then emergent light also has no regularity, thereby reduces the optically focused performance, result, the problem that existence can cause light quantity to reduce.Yet in the present embodiment, crest line 18 directions of deflection graphic elements 17 (arrow of Figure 14 (a)) are whole towards the y direction of principal axis, but thereby both had also optically focused of no regularity.Have again, certainly, above-mentioned P can be set fully irregularly
L, P
R, also can be without any relevant.
(the 3rd embodiment)
In the above-mentioned the 1st and the 2nd embodiment, the parallelogram of the quadrangular pyramid bottom surface of deflection graphic elements (perhaps rhombus) one side four limits respectively with the straight line that forms of adjacent parallelogram.Yet one of LGP of the present invention is characterised in that, is arranged with the deflection graphic elements shown in a plurality of Fig. 7 (a), thus, can obtain to provide the LGP of the back lighting device that improves light utilization ratio and high brightness, so needn't arrange as mentioned above.That is, make parallelogram " skew " a little, as shown in figure 15, the one side that only also can be in four limits of parallelogram or rhombus the parallelogram of one group of parallel both sides and adjacency forms straight line.This mode is compared with the 2nd embodiment with the 1st, and difficulty in the manufacturing but then, gives the arrangement no regularity of deflection graphic elements by " skew ", and also can improve outward appearance, also can obtain effect in ripple elimination etc.
(the 4th embodiment)
In the above-mentioned the 1st and the 2nd embodiment, be near the dark portion the elimination light source, and the deflection graphic elements is made parallelogram or rhombus.Yet, more when the quantity of LED, use linear light source and can't see on the structure of liquid crystal indicator under the situation of dark portion, sometimes need not the deflection graphic elements is made parallelogram or rhombus.This situation shown in Figure 16 (a) or Figure 16 (b), also can make reflection groove from as the straight line of the direction that is parallel to x axle or y axle but it is spaced apart random LGP.
(to the processing of exit facet)
Preferably on exit facet 3, be formed with and have anisotropic anisotropy diffusion pattern, preferred this anisotropy diffusion pattern is its light diffusion property for the half-value angles with 30～70 degree carry out abnormity diffusion on the direction of the plane of incidence being parallel to, and the half-value angle with 0.5～3 degree on perpendicular to the direction of the plane of incidence carries out the figure that abnormity spreads.
In addition, preferably form hologram as above-mentioned anisotropy diffusion pattern, preferably this hologram is surface fluctuation type hologram (for to be different from three-dimensionally formed hologram, and being called the surface fluctuation type hologram).Thus, be orthogonal to a plurality of random spot area that has long wire on the direction of the plane of incidence.
(back lighting device)
As the back lighting device that has used LGP of the present invention, can be as explained shown in Figure 6 and dispose, in addition, and also can be as shown in figure 17, the deflection graphic elements 17 of LGP is arranged on the exit facet 3.Thus, compare, have light source 2 tendency that near outward appearance becomes better, brightness improves, so more satisfactory with the LGP of in the 1st embodiment deflection graphic elements 17 being located at reflecting surface 4.
As described in the 1st embodiment, deflection graphic elements 17 is located at reflecting surface 4 sides, still as the 4th embodiment deflection graphic elements 17 is located at exit facet 3 sides, can freely select according to purposes.For example, when deflection graphic elements 17 was located at exit facet 3 sides, then the reverse side that becomes good owing near the outward appearances the light source 2, the prismatic lens 6 of use were observed the bullate situation of appearance between prismatic lens 6 and the LGP 1 sometimes.On the other hand, if the 1st embodiment implement, then since brightness or outward appearance compare with the 4th embodiment variation slightly reverse side, on exit facet, be not formed with deflection graphic elements 17, so can implement other processing at exit facet.For example, for reducing the inequality and the ripple of emergent light, can implement asperities processing at exit facet.Certainly, also can carry out same asperities processing in the 4th embodiment, but because asperities is configured in apart from observer position far away, so compare with the 1st embodiment, effect is relatively poor.
(to the processing of the face of zero deflection figure)
In LGP of the present invention, preferably on the face that is not formed with deflection graphic elements 17, form and have anisotropic anisotropy diffusion pattern, preferred this anisotropy diffusion pattern is its light diffusion property for the half-value angles with 30～70 degree carry out abnormity diffusion on the direction of the plane of incidence being parallel to, and the half-value angle with 0.5～3 degree on perpendicular to the direction of the plane of incidence carries out the figure that abnormity spreads.
In addition, preferably be formed with hologram as above-mentioned anisotropy diffusion pattern, preferably this hologram is the hologram (for to be different from three-dimensionally formed hologram, and being called the hologram of surface fluctuation type) of surface fluctuation type.Thus, be orthogonal to a plurality of random spot area that has long wire on the direction of the plane of incidence.
Figure 18 and Figure 19 are the enlarged drawings of details that expression is formed at holographic Figure 100 of exit facet 3.Figure 18 is the enlarged drawing after hologram is enlarged 200 times, and Figure 19 is the enlarged drawing after hologram is further amplified.
As shown in figure 18, when hologram is observed about 200 times of expansions, have a plurality of random hot spot or random spot area 100a (for example comparing penetrance higher (perhaps lower) zone) (random groove or concavo-convex) with other zone in the upwardly extending wire in side that is orthogonal to the plane of incidence 4.The shape of this random hot spot 100a and position have no regularity in whole hologram and on-fixed.
As described below, by wire hot spot 100a, and then the light that is incident to hologram has at strong diffusion property then more weak on the orthogonal direction on the direction that is parallel to the plane of incidence 5.The diffusion ratio of the parallel direction parallel with the plane of incidence 5 and the diffusance of orthogonal direction is the size decision by the major axis of hot spot and minor axis.
In addition, because the no regularity of hot spot 100a, the incident light of directive hologram can or penetrate to random direction scattering.Therefore, hologram has the function as diffuser.
Figure 20 is the figure that the explanation hologram is used.
Figure 20 (a) is the vertical view of the angle interdependence of the emitted light intensity of some P1, the P2 of expression on the exit facet 3 of LGP 1.Figure 20 (b) is the stereogram that the light intensity of the some P2 ejaculation of stereo representation on the exit facet 3 of LGP 1 distributes.
The light that some P1, P2 on the exit facet 3 of LGP 1 penetrates has owing to the holographic Figure 100 that is formed on the exit facet 3, shown in oval E1, E2, in the strong diffusivity then more weak on orthogonal direction of the direction diffusion that is parallel to the above-mentioned plane of incidence 5.
Figure 21 represents the intensity distributions of above-mentioned emergent light.The intensity distributions of the above-mentioned emergent light of the above-mentioned θ direction of Figure 21 (a) expression, the intensity distributions of the above-mentioned emergent light of the above-mentioned r direction of Figure 21 (b) expression.
As mentioned above, compare with the direction r of the plane of incidence 5 quadratures, it is stronger that parallel direction θ goes up diffusion, the angle of flare φ of θ direction
0Half range value φ
θ 0, much larger than the angle of flare φ of r direction
rHalf range value φ
R0(φ
θ 0＞＞φ
R0).
The half range value φ of above-mentioned r direction
R00.5＜φ preferably
R0≦ 3 degree, preferred 1＜φ
R0≦ 2 degree.On the other hand, the half range value φ of θ direction
θ 0Better be 30～70 degree, be more preferably 45～65 degree, preferred 50～60 degree.
Utilize the anisotropy diffusion of above-mentioned hologram, in this LGP 1, can realize with the θ direction on the intensity distributions of identical emergent light.Especially can prevent bright line from the emergent light of exit facet 3.
(optical sheet)
Figure 22 is the schematic diagram of a part that expression has the back lighting device 50 (perhaps planar light source device) of LGP and optical sheet.In having the back lighting device 50 of LGP 1 and optical sheet (prismatic film) 10, the light that penetrates from the exit facet 3 of LGP 1 contains the light L of the less composition of the angle γ 1 that forms with exit facet 3, γ 2
1, L
2Optical sheet 10 has the lower surface (10B) of smooth upper surface (10A) and prism-like, when with the less light L of exit facet 3 formed angles of LGP 1
1, L
2After lower surface (10B) incident, can form bigger angle and deflection outgoing (L with upper surface (10A)
1', L
2').So, optical sheet 10 can improve the positive intensity to the light of liquid crystal indicator outgoing.
As this optical sheet, do not do special restriction as long as have general prism structure, specifically, for example, can enumerate M065HS (the レ イ ヨ of Mitsubishi Application), M168YS (the レ イ ヨ of Mitsubishi Application), T-BEM (3M) etc., these can only use one or two or more, also or will be used in combination more than two.
As above-mentioned back lighting device (perhaps planar light source device), can in the liquid crystal indicator of portable phone electronic notebook etc., be used as backlight.
Moreover above-mentioned embodiment is expression a specific example of the present invention, but the present invention is not limited only to this.As long as do not depart from the scope of the present invention, then applicable to various objects.In addition, the numerical value shown in the embodiment is an example only, but the present invention also is not limited only to this certainly.
For example, about above-mentioned light source, spot light gets final product in fact, but also can be single-chip LED, two chip LED or multi-chip LED.
Claims (27)
1. a LGP is to have the plane of incidence in the side, has the tabular LGP of exit facet at upper surface or lower surface, it is characterized in that:
Above-mentioned exit facet or with opposed of above-mentioned exit facet on be arranged with a plurality of deflection graphic elements;
This deflection graphic elements has quadrangle cone shape, and four faces beyond its quadrangular pyramid bottom surface are integrally formed on this LGP;
The 1st adjacent area separately in above-mentioned four faces with the 2nd be adjacent the 3rd with the 4th more than 10 times of area separately;
Above-mentioned the 1st with above-mentioned the 2nd inclination angle separately less than above-mentioned the 3rd with the 4th inclination angle separately.
2. LGP as claimed in claim 1 is characterized in that: the quadrangle cone shape of above-mentioned deflection graphic elements is arranged with (depressed) in LGP.
3. LGP as claimed in claim 1 is characterized in that: the spacing P that roughly is the deflection graphic elements of quadrangular pyramid
SFixing.
4. LGP as claimed in claim 1 is characterized in that: the spacing P that roughly is the deflection graphic elements of quadrangular pyramid
SIndefinite.
5. LGP as claimed in claim 1 is characterized in that: above-mentioned the 1st relative above-mentioned exit facet with above-mentioned the 2nd inclination angle separately is 0.5～3 °.
6. LGP as claimed in claim 1 is characterized in that: the bottom surface of the quadrangle cone shape of above-mentioned deflection graphic elements is a parallelogram.
7. LGP as claimed in claim 6 is characterized in that: the formed angle θ of the limit of above-mentioned parallelogram and the plane of incidence
RWith θ
LRespectively above 0 and below 60 °.
8. LGP as claimed in claim 7 is characterized in that: above-mentioned θ
LWith θ
RAngle identical.
9. LGP as claimed in claim 6 is characterized in that: one side being in line of one group of parallel both sides in four limits of above-mentioned parallelogram and adjacent parallelogram.
10. LGP as claimed in claim 6 is characterized in that: one side being in line of each limit on four limits in the above-mentioned parallelogram and adjacent parallelogram.
11. a LGP as claimed in claim 10 is characterized in that:
Become θ with incidence surface
LThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
L(1), P
L(2) ... P
L(m);
Become θ with incidence surface
RThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
R(1), P
R(2) ... P
RWhen (n) representing;
P
L(m) and P
R(n) all be identical numerical value.
12. a LGP as claimed in claim 10 is characterized in that:
Become θ with incidence surface
LThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
L(1), P
L(2) ... P
L(m);
Become θ with incidence surface
RThe straight line group's at angle spacing is expressed as P successively from the incidence surface side
R(1), P
R(2) ... P
RWhen (n) representing;
P
L(m) and P
R(n) setting value is a random number.
13. LGP as claimed in claim 12 is characterized in that: above-mentioned P
LWith above-mentioned P
RSatisfy P
L(1)=P
R(1), P
L(2)=P
R(2) ... P
L(n)=P
R(n) relation.
14. LGP as claimed in claim 13 is characterized in that: above-mentioned P
LAnd above-mentioned P
RMedian be respectively 30～500 μ m.
15. LGP as claimed in claim 12 is characterized in that: the scope of above-mentioned random number be above-mentioned median ± 15% or ± 20 μ m.
16. LGP as claimed in claim 12 is characterized in that: the angle that normal became of above-mentioned the 1st and above-mentioned second formed crest line and the above-mentioned plane of incidence is in ± 40 °.
17. LGP as claimed in claim 1 is characterized in that: above-mentioned deflection graphic elements be formed on opposed of above-mentioned exit facet on, on exit facet, be formed with other optical element.
18. LGP as claimed in claim 17 is characterized in that: above-mentioned other optical element has the function of diffusion or optically focused emergent light.
19. LGP as claimed in claim 17 is characterized in that: above-mentioned other optical element has each to different diffusion property.
20. a back lighting device is characterized in that:
Possess as any one described LGP of claim 1 to 19.
21. LGP, make in the side and have the plane of incidence, the tabular LGP that has exit facet at upper surface or lower surface, and with opposed of above-mentioned exit facet on the adjacent rows deflection graphic elements showing roughly to be quadrangular pyramid, this deflection graphic elements is formed on the direction of general wall thickness attenuation of relative LGP, four sides beyond the quadrangular pyramid bottom surface in the shape of this quadrangular pyramid is integrally formed on the LGP, it is characterized in that:
In the four sides beyond the bottom surface the 1st is respectively other the 3rd or the 4th 's more than 20 times of area with the 2nd face;
Above-mentioned the 1st and the 2nd 's crest line and plane of incidence quadrature;
The inclination angle of the above-mentioned the 1st and the 2nd above-mentioned relatively exit facet is in the scope of 0.5～3 degree;
The the above-mentioned the 1st and the 2nd is roughly the same area;
The the above-mentioned the 3rd and the 4th is roughly the same area.
22. LGP as claimed in claim 21 is characterized in that: be formed with the surface fluctuation type hologram in the exit facet side.
23. as claim 21 or 22 described LGPs, it is characterized in that: the spacing that roughly is the deflection graphic elements of quadrangular pyramid is fixed.
24. as claim 21 or 22 described LGPs, it is characterized in that: the spacing of deflection graphic elements that roughly is quadrangular pyramid is indefinite.
25., it is characterized in that as claim 21 or 22 described LGPs: above-mentioned surface fluctuation type hologram have with the direction of plane of incidence quadrature on be a plurality of random spot area of long wire.
26. as claim 21 or 22 described LGPs, it is characterized in that: the light diffusion property of above-mentioned surface fluctuation type hologram is for carrying out abnormity diffusion at the half-value angles that are parallel on the direction of the plane of incidence with 30～70 degree, carries out abnormity with the half-value angle of 0.5～3 degree on perpendicular to the direction of the plane of incidence and spreads.
27. a back lighting device is characterized in that:
Possess as any one described LGP of claim 21 to 26.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2004336478 | 2004-11-19 | ||
| JP336478/2004 | 2004-11-19 | ||
| JP228081/2005 | 2005-08-05 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN101061347A true CN101061347A (en) | 2007-10-24 |
Family
ID=38866660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CNA2005800395096A Pending CN101061347A (en) | 2004-11-19 | 2005-11-17 | Light guide plate |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN101061347A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102084173A (en) * | 2008-07-07 | 2011-06-01 | 夏普株式会社 | Lighting device and liquid crystal display device |
| CN106796002A (en) * | 2015-05-15 | 2017-05-31 | 松下知识产权经营株式会社 | Area lighting source illumination device |
| CN110622236A (en) * | 2017-08-10 | 2019-12-27 | 欧姆龙株式会社 | Display device and light guide plate |
-
2005
- 2005-11-17 CN CNA2005800395096A patent/CN101061347A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102084173A (en) * | 2008-07-07 | 2011-06-01 | 夏普株式会社 | Lighting device and liquid crystal display device |
| CN106796002A (en) * | 2015-05-15 | 2017-05-31 | 松下知识产权经营株式会社 | Area lighting source illumination device |
| CN110622236A (en) * | 2017-08-10 | 2019-12-27 | 欧姆龙株式会社 | Display device and light guide plate |
| CN110622236B (en) * | 2017-08-10 | 2021-08-31 | 欧姆龙株式会社 | Display device and light guide plate |
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