CN103782082A - Light guide plate, surface light source device, and transmissive image display device - Google Patents

Abstract

The present invention provides a light guide plate, a surface light source device, and a transmissive image display device. A light guide plate (50) is provided with a board-like main body section (51) and a plurality of lens sections (52). The main body section has: a first surface (51a), which extends in one direction, and has formed thereon a plurality of protruding strip-like sections (55) disposed in parallel in the direction substantially orthogonally intersecting the one direction; a second surface (51b) on the reverse side of the first surface; and light input surfaces (51c, 51d), which are surfaces that respectively intersect the first and the second surfaces, and have light inputted thereto. Each of the lens sections is formed on the second surface of the main body section, and is convex to the side opposite to the side having the first surface when viewed from the second surface.

Description

LGP, planar light source device and transmission image display device

Technical field

The present invention relates to LGP, planar light source device and transmission image display device.

Background technology

The transmission image display devices such as liquid crystal indicator generally have planar light source device, and this planar light source device is disposed at the rear side of the such transmission type image display part of display panels and supplies with backlight to transmission type image display part.Be known to the planar light source device (for example,, with reference to patent documentation 1) of edge light type as such planar light source device.

The planar light source device of edge light type possesses: the LGP with light transmission; And be disposed at the side of LGP and supply with the light source of light for side to LGP.Be provided with for catoptrical white point in the rear side of LGP.In this structure, from the light of light source output from inciding in LGP with the side of the opposed LGP of light source, propagate in LGP inner total reflection simultaneously.For example, owing to being formed with multiple white points (, with reference to patent documentation 1) in the rear side of LGP, so the light being reflected by white point penetrates from the outgoing plane of the transmission type image display part side of LGP.

Patent documentation 1: TOHKEMY 2005-38768 communique

But in the albomaculatus LGP of tool, the light that incides LGP can not fully penetrate from outgoing plane, and cannot fully realize the raising of brightness.

Summary of the invention

Therefore, the object of the present invention is to provide a kind of LGP of the raising that can realize brightness, the planar light source device that comprises this LGP and transmission image display device.

LGP of the present invention possesses tabular main part and multiple lens section.Main part has first surface, its be formed with multiple along direction extend and with the roughly convex strip portions of configuration side by side in orthogonal direction of a direction; Second, its opposition side in first surface; And the plane of incidence, it is with first surface and second face intersecting and supplies light incident.Lens section is formed at second of main part, and protrudes towards a side contrary with a side at first surface place from second observation.

Planar light source device of the present invention possesses: above-mentioned LGP; And light source portion, the plane of incidence arranged opposite of itself and LGP, supplies with light to the plane of incidence.

In addition, transmission image display device of the present invention possesses: above-mentioned LGP; Light source portion, the plane of incidence arranged opposite of itself and LGP, supplies with light to the plane of incidence; And transmission type image display part, it is arranged at the first surface side of LGP, utilize from LGP penetrate optical illumination and show image.

In LGP, planar light source device and the transmission image display device of above-mentioned formation, propagate in LGP inner total reflection from the light of the plane of incidence incident of LGP simultaneously.If the light of propagating in LGP incides the lens section being arranged on second, reflect under the condition different from the condition of total reflection based on lens section.Therefore the light, being reflected by lens section penetrates from the first surface of main part.Be formed with convex strip portions at first surface, improve so light penetrates efficiency.Improve by above-mentioned effect brightness.And, in transmission image display device of the present invention, on LGP, be provided with transmission type image display part, so transmission type image display part is thrown light on the higher light of brightness.Consequently, can realize the raising of the brightness of the image being shown by transmission type image display part.

In addition, in LGP of the present invention, planar light source device and transmission image display device, the convex strip portions that can make to be formed at first surface is biconvex lens or prism.

According to the present invention, can provide the LGP of the raising that can realize brightness, the planar light source device that comprises this LGP and transmission image display device.

Accompanying drawing explanation

Fig. 1 is the schematic diagram that has represented to apply the brief configuration of the transmission image display device of an embodiment of LGP of the present invention.

Fig. 2 is the top view of observing the situation of the LGP shown in Fig. 1 from rear side.

Fig. 3 is the side view of observing the situation of the LGP shown in Fig. 1 from light source side.

Fig. 4 is the figure of the example of the outer shape for convex strip portions is described.

Fig. 5 is the figure that represents the example of the section shape of convex strip portions.

Fig. 6 is the figure that represents the example of the section shape of convex strip portions.

Fig. 7 is the figure that represents the example of the section shape of convex strip portions.

Fig. 8 is the figure of the example of the outer shape for lens section is described.

Fig. 9 is the chart that represents the condition of the outer shape of regulation lens section.

Figure 10 is the figure that represents the outer shape of lens section.

Figure 11 is the aspect ratio [h that represents to calculate by observation the lens section being formed by ink-jet method _iIa/ w _iIa] and sharp degree (と Ga り side) k _iIathe figure of result.

Figure 12 is the aspect ratio [h that represents the lens section forming by ink-jet method _iIa/ w _iIaand sharp degree k _iIathe figure of scope.

Figure 13 is the sharp degree k representing with respect to as shown in Figure 12 _iIaand aspect ratio ［ h _iIa/ w _iIathe width w of lens shape that determines _iIathe radius of curvature r of top ends _iIchart.

Figure 14 is the sharp degree k representing with respect to as shown in Figure 12 _iIaand aspect ratio ［ h _iIa/ w _iIathe width w of lens shape that determines _iIathe radius of curvature r of top ends _iIchart.

Figure 15 is by representing the sharp degree k shown in Figure 12 _iIaand aspect ratio ［ h _iIa/ w _iIathe bottom angle γ of lens shape that determines _iIchart.

Figure 16 is the sharp degree k representing as shown in Figure 12 _iIaand aspect ratio ［ h _iIa/ w _iIathe bottom angle γ of lens shape that determines _iIchart.

Figure 17 is the chart that represents the condition of the outer shape of regulation lens section.

Figure 18 is the schematic diagram that represents simulation model.

Figure 19 is the figure that represents to be formed at the lenticular coverage rate distribution of the rear side of the LGP using in simulation.

Figure 20 is the figure that represents to be formed at the lenticular coverage rate distribution of the rear side of the LGP using in simulation.

Figure 21 is the figure that is illustrated in the directional property of the point source of light using in simulation.

Figure 22 is the chart that represents the result of simulation.

Figure 23 is the figure of the example (embodiment A1) that represents other section shape of convex strip portions.

Figure 24 is the figure of the example (embodiment A2) that represents other section shape of convex strip portions.

Figure 25 is the figure of the example (embodiment A3) that represents other section shape of convex strip portions.

Figure 26 is the figure of the example (embodiment A4) that represents other section shape of convex strip portions.

Figure 27 is the figure of the example (embodiment A5) that represents other section shape of convex strip portions.

Figure 28 is the figure that represents the part of other section shape of convex strip portions.

Figure 29 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment A1, A2).

Figure 30 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment A3, A4).

Figure 31 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment A5).

Figure 32 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of Δ α/Δ L.

Figure 33 is the figure of the example (embodiment B1) that represents other section shape of convex strip portions.

Figure 34 is the figure of the example (embodiment B2) that represents other section shape of convex strip portions.

Figure 35 is the figure of the example (embodiment B3) that represents other section shape of convex strip portions.

Figure 36 is the figure of the example (embodiment B4) that represents other section shape of convex strip portions.

Figure 37 is the figure of the example (embodiment B5) that represents other section shape of convex strip portions.

Figure 38 is the figure that represents the part of other section shape of convex strip portions.

Figure 39 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment B1, B2).

Figure 40 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment B3, B4).

Figure 41 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of inclined angle alpha (embodiment B5).

Figure 42 represents the line segment length L of other section shape of convex strip portions and the figure of the relation of Δ α/Δ L.

The specific embodiment

Below, with reference to accompanying drawing, embodiments of the present invention are described.In the description of the drawings, to identical element mark same reference numerals, also the repetitive description thereof will be omitted.The dimensional ratios of accompanying drawing may not be consistent with the object of explanation.In addition, in explanation, represent " on ", the word of the direction such as D score is the word easily based on state shown in the drawings.

Fig. 1 is the schematic diagram that has represented to apply the brief configuration of the transmission image display device of an embodiment of LGP of the present invention.In Fig. 1, decompose the cross-section structure that shows transmission image display device 10.Transmission image display device 10 can be applicable to display unit, the television equipment of mobile phone, various electronic equipments.

Transmission image display device 10 possesses transmission type image display part 20 and exports the planar light source device 30 of the planar light for supplying with to transmission type image display part 20.Below, for convenience of description, as shown in Figure 1, the direction that is arranged with transmission type image display part 20 with respect to planar light source device 30 is called to Z-direction or frontal.In addition, will be called X-direction and Y direction with the orthogonal both direction of Z-direction.X-direction and Y direction are mutually orthogonal.

Thereby the planar optical illumination that transmission type image display part 20 is penetrated from planar light source device 30 shows image.The example of transmission type image display part 20 is the display panels as Polarizer fitting body that dispose linear polarization plate 22,23 on the two sides of liquid crystal cells 21.In this case, transmission image display device 10 is liquid crystal indicator (or LCD TVs).Liquid crystal cells 21 and Polarizer 22,23 can use the structure using in the transmission image display devices such as existing liquid crystal indicator.The example of liquid crystal cells 21 is liquid crystal cells, liquid crystal cells of STN (Super Twisted Nematic) type etc. of TFT (Thin Film Transistor) type.

Planar light source device 30 is back light units of transmission type image display part 20 being supplied with to edge light type backlight.The light source portion 60,60 that planar light source device 30 possesses LGP 50 and configures opposed to each other respectively with mutual opposed side 50a, the 50b of LGP 50.

Light source portion 60,60 has multiple point source of lights 61 that are arranged as wire (arranging along Y direction in Fig. 1).The example of point source of light 61 is light emitting diodes.Light source portion 60 to LGP 50 incident lights, can possess the catoptrical reflector as reflecting part for efficiently in a side contrary with LGP 50.Here, exemplified with the light source portion 60 with multiple point source of lights 61, but light source portion 60 can be also the linear light sources such as cold-cathode tube (CCFL:Cold Cathode Fluorescent Lamp).

Planar light source device 30 can possess and is positioned at respect to LGP 50 and the reflecting part 70 of a side contrary with a side at transmission type image display part 20 places.Reflecting part 70 is for again inciding LGP 50 by the light penetrating to reflecting part 70 sides from LGP 50.As shown in Figure 1, reflecting part 70 can be sheet.In addition, reflecting part 70 can be storage LGP 50 planar light source device 30 framework bottom surface and be the bottom surface of having implemented mirror finish.

With reference to Fig. 1～Fig. 3, LGP 50 is described.Fig. 2 is the top view of observing the situation of the LGP 50 shown in Fig. 1 from rear side.Fig. 3 is the left side view of observing the situation of the LGP 50 shown in Fig. 1 from left surface side.The example of the plan view shape of LGP 50 comprises approximate rectangle and approximate square.

LGP 50 has: tabular main part 51, and it is formed with convex strip portions 55 in a side that becomes the outgoing plane of main part 51 (first surface) 51a; With multiple lens sections 52, they are formed on a side of the back side that becomes main part 51 (the second face) 51b in a side contrary with the face that is formed with convex strip portions 55.Main part 51 is made up of translucent material (or transparent material).The example of the refractive index of translucent material is 1.46～1.62.The example of translucent material comprises translucent resin material, translucent glass material.The example of translucent resin material comprises polycarbonate resin (refractive index: 1.59), MS resin (copolymer of methyl methacrylatestyrene resin) (refractive index: 1.56～1.59), polystyrene resin (refractive index: 1.59), AS resin (acrylonitritrile-styrene resin resin) (refractive index: 1.56～1.59), acrylic acid series ultraviolet curable resin (refractive index: 1.46～1.58), polymethyl methacrylate (PMMA) (refractive index: 1.49).Consider from transparent viewpoint, translucent resin material is more preferably PMMA.

As shown in FIG. 1 to 3, main part 51 has and the back side 51b of the mutual opposed outgoing plane 51a of transmission type image display part 20, opposition side in outgoing plane 51a and four side 51c, 51d, 51e, the 51f intersecting with outgoing plane 51a and back side 51b.In Fig. 1, show two at the mutual opposed side 51c of X-direction and 51d.Side 51c and side 51d are also and the opposed above-mentioned side 50a of light source portion 60 and side 50b.In this case, side 51c and side 51d are the planes of incidence for the light incident from light source portion 60.Remaining two side 51e, 51f (with reference to Fig. 3) in four side 51c, 51d, 51e, 51f that main part 51 has are mutually opposed in Y direction.In Fig. 1 and Fig. 3, as an example of the configuration relation of side 51c, 51d, 51e, 51f and outgoing plane 51a and back side 51b, show side 51c, 51d, 51e, 51f respectively with roughly orthogonal state of outgoing plane 51a and back side 51b.

Next, the convex strip portions 55 of the outgoing plane 51a side that is formed at main part 51 is described.Here be made as for the purpose of simplifying the description, identical the describing of size of multiple convex strip portions 55.Convex strip portions 55 is transparent, and the light from LGP 50 is penetrated towards transmission type image display part 20.In addition, the outer shape of convex strip portions 55 has the outer shape of biconvex lens as shown in Figure 3.

Multiple convex strip portions 55 extend along the X-direction shown in Fig. 1 and Fig. 3, and configure side by side in Y direction.Roughly even with the section shape that the bearing of trend of convex strip portions 55 is orthogonal.As shown in Figure 3 and 4, multiple convex strip portions 55 can with the convex strip portions 55 in short side direction (Y direction) adjacency each other the empty mode of opening constant distance S configure, now between the 55b of bottom, form par 55c at the end of the convex strip portions 55 adjoining each other.The coverage rate of multiple convex strip portions 55 of the outgoing plane 51a of main part 51 can be adjusted apart from S (length of par 55c) by changing.For example, if the convex strip portions in short side direction adjacency 55 is configured in gapless mode each other, make the i.e. position (the distance S shown in Fig. 4 is 0) consistent with each other of bottom 55b of end of the convex strip portions 55 of adjacency, its coverage rate is 100%.The coverage rate of multiple convex strip portions 55 of the outgoing plane 51a of main part 51 is generally 50%～100%.

Next, the various examples of the outer shape to convex strip portions 55 describe.Here for for convenience of description and definition datum face 51g., datum level 51g is defined as shown in Figure 4 in the section of convex strip portions 55 with by the face of line parallel connected to each other bottom 55b described later (representing with single-point line in Fig. 4), form the plane of the bottom surface of convex strip portions 55.In the present embodiment, the back side 51b (with reference to Fig. 1) of LGP 50 is parallel to each other with datum level 51g.

For example, the outer shape of convex strip portions 55 can be by aspect ratio (h shown below _ia/ w _ia), with respect to the radius of curvature (r of width _i/ w _ia), bottom angle γ _icombination and the shape that stipulates.Below, with reference to Fig. 4, to aspect ratio (h _ia/ w _ia), with respect to the radius of curvature (r of width _i/ w _ia), bottom angle γ _idescribe.

(I) aspect ratio (h _ia/ w _ia)

Aspect ratio (h _ia/ w _ia) refer in Fig. 4 the width of convex strip portions 55 is made as to w _ia(μ m), be made as h by the maximum height of convex strip portions 55 _ia(μ is m) time, maximum height h _iawith width w _iaratio.

(II) with respect to the radius of curvature (r of width _i/ w _ia)

With respect to the radius of curvature (r of width _i/ w _ia) refer to the width of convex strip portions 55 is being made as to w _ia(μ m), be made as r by the radius of curvature of the top ends 55a of convex strip portions 55 _i(μ is m) time, radius of curvature r _iwith width w _iaratio.The radius of curvature r of top ends 55a _iexpression is as the bending situation of the top ends 55a at the top of convex strip portions 55.For example, as shown in Figure 4, the radius of curvature r of top ends 55a _isupposition with the situation of the tangent circle (circle dotting in Fig. 4) of top ends 55a under radius of a circle.

(III) bottom angle γ _i

Bottom angle γ _ithe section P of the convex strip portions 55 of the position of the outline line of convex strip portions 55 in the section orthogonal with bearing of trend and the intersection point of datum level 51g _iand angulation between datum level 51g.Bottom 55b is the bottom of convex strip portions 55 with respect to top ends 55a.Therefore, bottom angle γ _ialso be bottom angle.

Fig. 4 shows the structure of the section orthogonal with the bearing of trend of convex strip portions 55.W _iait is the width of convex strip portions 55.In addition, h _iathe thickness of the position of the top ends 55a of convex strip portions 55.Therefore, above-mentioned aspect ratio [h _ia/ w _ia] with the thickness (or height) of the convex strip portions 55 of the position of the top ends 55a of the width with respect to convex strip portions 55, [thickness of top ends position ］/[width of convex strip portions] corresponding.Conventionally, the thickness maximum of the convex strip portions 55 of the position of top ends 55a, so the thickness of the convex strip portions 55 of the position of top ends 55a is also the maximum ga(u)ge of convex strip portions 55.In addition, the ratio that above-mentioned (II) records is corresponding to radius of curvature r _iwith the ratio of the width of convex strip portions 55, [radius of curvature ］/[width of convex strip portions ］.

In addition, the outer shape of convex strip portions 55, except the condition regulation of above-mentioned (I)～(III), also can be defined as the outline line of convex strip portions 55 the represented conic section of following formula (1).In Fig. 5, using with the bearing of trend (X-direction) of the convex strip portions 55 shown in Fig. 1 and Fig. 3 orthogonal and column direction (Y direction) as u _iaxle is set u _iv _icoordinate system.Here u, _iaxle is corresponding with axle (Y-axis) that be parallel to multiple convex strip portions 55 and column direction.V _iaxle is corresponding with the axle (Z axis) of thickness direction that is parallel to LGP 50.At this u _iv _ithe u of coordinate system _iv _iin face, the section shape of convex strip portions 55 is: both ends 55b, 55b are positioned at u _ion axle, top ends 55a is positioned at v _ion axle.Now the outer shape of convex strip portions 55 can be formed as: and the tangent section P of convex strip portions 55 _iwith datum level 51g angulation from the bottom 55b side of convex strip portions 55 towards top ends 55a side monotone decreasing.

［ formula 1 ］

$v_I\left(u_I\right)=h_{\mathrm{Ia}}-\frac{{{8h}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}{1-k_{\mathrm{Ia}}+\sqrt{{{(1-k_{\mathrm{Ia}})}^2+{16k}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}}---\left(1\right)$

In formula (1), w _iathat convex strip portions 55 is at u _iaxial length.In formula (1), h _iabecome v with making convex strip portions 55 _i(u _i) shown in the situation of shape under both ends 55b, the 55b of convex strip portions 55 between maximum height correspondence.In formula (1), k _iait is the parameter that represents the sharp degree of the top ends 55a of convex strip portions 55.For example, at sharp degree k _iabe 0 o'clock, the profile of convex strip portions 55 is parabolic shape, at sharp degree k _iabe 1 o'clock, the profile of convex strip portions 55 is prism shape, at sharp degree k _iafor-1 o'clock, the profile of convex strip portions 55 was the shape that ellipse is cut into half.

And the outer shape of convex strip portions 55, in the time representing the outline line of convex strip portions 55 with the conic section of regulation, can be passed through aspect ratio (h _ia/ w _ia) and sharp degree k _iato be combined into professional etiquette fixed.Can enumerate the following combination such as (A), (B) as an example of combinations thereof.

(A)h _Ia/w _Ia=0.390，k _Ia=-0.390

(B)h _Ia/w _Ia=0.232，k _Ia=0.021

Fig. 5 shows the combination (h by above-mentioned (A) _ia/ w _ia=0.390, k _ia=-0.390) section shape of regulation.Fig. 6 shows the combination (h by above-mentioned (B) _ia/ w _ia=0.232, k _ia=0.021) section shape of regulation.The coverage rate of multiple convex strip portions 55 of the outgoing plane 51a of main part 51 can be by being adjusted at short side direction (Y direction) adjacency distance S each other of convex strip portions 55 suitably set.The section shape of convex strip portions 55 has with respect to v _iaxisymmetric outline line.Width w _iaexample be that 10 μ m are above and below 2mm, be preferably 20 μ m above and below 1mm, be more preferably 50 μ m above and below 600 μ m.

In addition, the outer shape of convex strip portions 55 also can be by the aspect ratio (h shown in following (C) _ia/ w _ia) and sharp degree k _iacombination stipulate.

(C)h _Ia／w _Ia=0.500，k _Ia=1.000

Fig. 7 shows the combination (h by above-mentioned (C) _ia/ w _ia=0.500, k _ia=1.000) section shape of regulation.In this case, the convex strip portions 55 that the coverage rate of multiple convex strip portions 55 of the outgoing plane 51a of main part 51 also can be by being adjusted at short side direction (Y direction) adjacency distance S each other suitably sets.The section shape of convex strip portions 55 has with respect to v _iaxisymmetric outline line.Width w _iaexample be that 10 μ m are above and below 2mm, be preferably 20 μ m above and below 1mm, be more preferably 50 μ m above and below 600 μ m.

Next, lens section 52 is described.For the purpose of simplifying the description, be made as identical the describing of size of multiple lens sections 52.As shown in Figure 1 and Figure 2, multiple lens sections 52 are formed on the back side 51b of main part 51.Lens section 52 is transparent, for the light in LGP 50 interior propagation is penetrated from outgoing plane 51a side.In addition, the outer shape of each lens section 52 is dome-shaped.

As shown in Figure 2, multiple lens sections 52 are arranged as clathrate at short side direction (Y direction) and the long side direction (X-direction) of main part 51, become so that the mode optimization that is 95% from the quantity of light emission uniformity of the outgoing plane 51a of LGP 50 coverage rate distribute.As an example that meets such quantity of light emission uniformity, can make a lens section 52 is 78.54% with respect to the coverage rate of the square lattice of the central portion of back side 51b.Lens section 52 also can be configured to staggered clathrate, six side's closest packing clathrates.In addition, even if can adjust coverage rate so that be that the position that is equivalent to each grid does not form lens section 52 yet.

Next, the shape of each lens section 52 is described.Fig. 8 is the accompanying drawing of the example of the outer shape for lens section 52 is described, is the central axis C that comprises lens section 52 _iIthe schematic diagram of cross-section structure of LGP 50.In lens section 52, the top of lens section 52 is called to the top ends 52a of lens section 52, the bottom of lens section 52 is called to the bottom 52b of lens section 52.In the present embodiment, the shape of lens section 52 is to make the section shape shown in Fig. 8 with central axis C _iIfor rotating shaft rotates the shape obtaining.Therefore, the shape of lens section 52 is comprising central axis C _iIsection arbitrarily in symmetrical.In addition, the outer shape that lens section 52 has is: and the tangent section P of lens section 52 _iIwith back side 51b angulation from the bottom 52b side of lens section 52 towards top ends 52a side monotone decreasing.

The various examples of the outer shape to lens section 52 describe.For example, the outer shape of lens section 52 can be formed as by the aspect ratio (h shown in the chart of Fig. 9 _iIa/ w _iIa), with respect to the radius of curvature (r of width _iI/ w _iIa), bottom angle γ _iIthe shape of combination regulation.Below, with reference to Fig. 8, to aspect ratio (h _iIa/ w _iIa), with respect to the radius of curvature (r of width _iI/ w _iIa), bottom angle γ _iIdescribe.

(I) aspect ratio (h _iIa/ w _iIa)

Aspect ratio (h _iIa/ w _iIa) refer in Fig. 8 the width of lens section 52 is being made as to w _iIa(μ m), be made as h by the maximum height of lens section 52 _iIa(μ is m) time, maximum height h _iIawith width w _iIaratio.

(II) with respect to the radius of curvature (r of width _iI/ w _iIa)

With respect to the radius of curvature (r of width _iI/ w _iIa) refer to the width of lens section 52 is being made as to w _iIa(μ m), be made as r by the radius of curvature of the top ends 52a of lens section 52 _iI(μ is m) time, radius of curvature r _iIwith width w _iIaratio.The radius of curvature r of top ends 52a _iIexpression is as the bending situation of the top ends 52a at the top of lens section 52.For example, as shown in Figure 8, the radius of curvature r of top ends 52a _iIsupposition with the situation of the tangent circle (circle that the dotted line in Fig. 8 represents) of top ends 52a under radius of a circle.

(III) bottom angle γ _iI

Bottom angle γ _iIto pass through central axis C _iIsection in the outline line of lens section 52 and the section P of the lens section 52 of the position of the intersection point of back side 51b _iIand angulation between the 51b of the back side.This bottom angle γ _iIcorresponding with the contact angle in the situation that lens section 52 is seen to droplets.In addition, bottom 52b is the bottom of lens section 52 with respect to top ends 52a.Therefore, bottom angle γ _iIalso be bottom angle.

Below, according to the situation difference of the aspect ratio ［ ha/wa ］ shown in the chart based on Fig. 9, illustrate particularly the condition of the satisfied outer shape of lens section 52.

(1) 0.07≤h _iIa/ w _iIathe situation of < 0.09

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.8594≤r _iI/ w _iIa≤ 1.7969 and 12.46≤γ _iI≤ 20.69

(2) 0.09≤h _iIa/w _iIathe situation of < 0.11

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.5625≤r _iI/ w _iIa≤ 1.4375 and 14.48≤γ _iI≤ 25.26

(3) 0.11≤h _iIa/ w _iIathe situation of < 0.13

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.4688≤r _iI/ w _iIa≤ 1.1979 and 17.22≤γ _iI≤ 29.52

(4) 0.13≤h _iIa/ w _iIathe situation of < 0.15

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.4018≤r _iI/ w _iIa≤ 1.4732 and 19.88≤γ _iI≤ 58.14

(5) 0.15≤h _iIa/ w _iIathe situation of < 0.17

The outer shape of lens section 52 is r/w _iIaand γ _iI(°) shape that meets the following conditions.

0.2734≤r _iI/ w _iIa≤ 1.2891 and 21.22≤γ _iI≤ 61.44

(6) 0.17≤h _iIa/ w _iIathe situation of < 0.19

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.2431≤r _iI/ w _iIa≤ 1.1458 and 23.59≤γ _iI≤ 64.16

(7) 0.19≤h _iIa/ w _iIathe situation of < 0.21

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.2188≤r _iI/ w _iIa≤ 1.2188 and 25.88≤γ _iI≤ 86.33

(8) 0.21≤h _iIa/ w _iIathe situation of < 0.23

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.3125≤r _iI/ w _iIa≤ 1.1080 and 31.28≤γ _iI≤ 86.68

(9) 0.23≤h _iIa/ w _iIathe situation of < 0.25

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.2865≤r _iI/ w _iIa≤ 1.0156 and 33.53≤γ _iI≤ 86.96

(10) 0.25≤h _iIa/ w _iIathe situation of < 0.27

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.4567≤r _iI/ w _iIa≤ 0.9375 and 44.76≤γ _iI≤ 87.20

(11) 0.27≤h _iIa/ w _iIathe situation of < 0.29

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.6920≤r _iI/ w _iIa≤ 0.7813 and 68.14≤γ _iI≤ 77.44

(12) 0.29≤h _iIa/ w _iIathe situation of < 0.31

The outer shape of lens section 52 is r _iI/ w _iIaand γ _iI(°) shape that meets the following conditions.

0.6458≤r _iI/ w _iIa≤ 0.7292 and 69.47≤γ _iI≤ 78.25

Fig. 8 shows the central axis C that comprises lens section 52 _iIthe structure of section, so width w _iIacorresponding with the Breadth Maximum of lens section 52.In addition, h _iIathe thickness of the position of the top ends 52a of lens section 52.Therefore, above-mentioned aspect ratio [h _iIa/ w _iIawith the thickness (or height) of the lens section 52 of the position of the 52a of the Breadth Maximum top ends with respect to lens section 52, [thickness of top ends position ］/[Breadth Maximum of lens section ］ corresponding.Conventionally, the thickness maximum of the lens section 52 of the position of top ends 52a, so the thickness of the lens section 52 of the position of top ends 52a is also the maximum ga(u)ge of lens section 52.In addition, the ratio that above-mentioned (II) records is corresponding to radius of curvature r _iIwith the ratio of the Breadth Maximum of lens section 52, [radius of curvature]/[Breadth Maximum of lens section ］.

In addition, the outer shape of lens section 52 as shown in figure 10, in the central axis C that comprises lens section 52 _iIthe cross-section structure of lens section 52 in, the outline line of lens section 52 can also be defined as to conic section.Particularly, as shown in figure 10, set u _iIv _iIcoordinate system, can be by the represented conic section v of following formula (2) _iI(u _iI) regulation lens section 52 section shape.U _iIv _iIthe v of coordinate system _iIthe central axis C of the lens section 52 of axle and Fig. 8 _iIcorresponding.In addition, u _iIaxle is corresponding with the X-direction shown in Fig. 1 and Fig. 2.

［ formula 2 ］

$v_{\mathrm{II}}\left(u_{\mathrm{II}}\right)=h_{\mathrm{IIa}}-\frac{{{8h}_{\mathrm{IIa}}\left(\frac{u_{\mathrm{II}}}{w_{\mathrm{IIa}}}\right)}^2}{1-k_{\mathrm{IIa}}+\sqrt{{{(1-k_{\mathrm{IIa}})}^2+{16k}_{\mathrm{IIa}}\left(\frac{u_{\mathrm{II}}}{w_{\mathrm{IIa}}}\right)}^2}}---\left(2\right)$

In formula (2), k _iIabe the parameter of the sharp degree of the conic section shown in expression (2), represent the sharp degree of the top ends 52a of lens section 52.For example, at sharp degree k _iIabe 0 o'clock, the profile of lens section 52 is parabolic shape, at sharp degree k _iIabe 1 o'clock, the profile of lens section 52 is prism shape, at sharp degree k _iIafor-1 o'clock, the profile of lens section 52 was the shape that ellipse is cut into half.

And the outer shape of lens section 52, can be by aspect ratio ［ h in the time that the outline line of lens section 52 is expressed as to the conic section of regulation _iIa/ w _iIaand sharp degree k _iIacombination stipulate.Can enumerate the combination of following (a)～(c) etc. as an example of combinations thereof.

(a)h _IIa／w _IIa=0.220，k _IIa=0.200

(b)h _IIa/w _IIa=0.120，k _IIa=0.400

(c)h _IIa/w _IIa=0.220，k _IIa=0.000

Width w _iIaexample be that 5 μ m are above and below 1mm, be preferably 10 μ m above and below 500 μ m.The lens section 52 of size is so-called lenticule like this.

The material of lens section 52 and convex strip portions 55 can adopt the material identical with main part 51.In addition, the material of lens section 52 and convex strip portions 55, can be different from the material of main part 51 as long as translucent material.

The main part 51 of the LGP 50 of above-mentioned formation can be the plate body of the individual layer that is made up of independent translucent material, can be also the plate body by the stacked multi-ply construction forming of layer that different translucent materials forms mutually.In addition,, in the case of the material of lens section 52 and convex strip portions 55 is identical with main part 51, LGP 50 can be the plate body being made up of independent translucent material.

And, in the case of using translucent resin material as forming the translucent material of main part 51, lens section 52 and convex strip portions 55, can in this translucent resin material, add the additives such as ultra-violet absorber, antistatic additive, antioxidant, processing stabilizers, fire retardant, lubricant.Above-mentioned additive can be distinguished use individually, or two or more is combined to use.In addition, if add ultra-violet absorber in LGP 50, contain a large amount of ultraviolet situations at the light of exporting from light source portion 60 inferior, can prevent the deterioration because of UV-induced LGP 50, therefore be preferred.

It is that ultra-violet absorber, benzophenone series ultra-violet absorber, cyanoacrylate are that ultra-violet absorber, malonate are that ultra-violet absorber, oxalic acid aniline are that ultra-violet absorber, triazine are ultra-violet absorber etc. that the example of ultra-violet absorber can be enumerated BTA, and preferably including BTA is that ultra-violet absorber, triazine are ultra-violet absorber.

Translucent resin material does not conventionally add light diffusing agent and uses as additive, but if do not depart from a small amount of of purport of the present invention, can add light diffusing agent and use.

Light diffusing agent adopts the specifically different powder of above-mentioned translucent material (or transparent material) of main composition main part 51, lens section 52 and convex strip portions 55 of refractive index and LGP 50, is distributed in translucent material and uses.The example of above-mentioned light diffusing agent comprises the inorganic particulates such as the organic filler such as styrene resin particle, methacrylic resin particle, potash particle, silicon dioxide granule.The particle diameter of light diffusing agent is generally 0.8 μ m～50 μ m.

The LGP 50 that possesses said lens portion 52 and convex strip portions 55 can be manufactured by ink jet printing (ink-jet method), photopolymer method (Off オ ト Port リ マ mono-method), extrusion modling or injection mo(u)lding etc.

In the time using ink jet printing (ink-jet method), photopolymer legal system to make LGP 50, can utilize the material of ultraviolet curable resin as lens section 52 and convex strip portions 55, can use acrylic acid series ultraviolet curable resin as ultraviolet curable resin.

Be that an example of the manufacture method of the LGP 50 in acrylic acid series ultraviolet curable resin the situation of utilizing ink-jet method describes to making the material of lens section 52.In this case, first, be formed on outgoing plane 51a side and have the main part 51 as plate body of convex strip portions 55 by extrusion modling or injection mo(u)lding etc.Next,, to becoming the face of back side 51b of main part 51 of such formation, operate ink gun while drip (printing) ultraviolet curable resin.Then, thus to ultraviolet curable resin irradiation ultraviolet radiation make its solidify form lens section 52.

In the situation that adopting ink-jet method to form lens section 52, need to be in the screen painting of the example as other printing process necessary master etc.Multiple lens sections 52 are normally by suitably repeatedly carrying out design process and trial-production operation, in the mode of brightness that improves the light penetrating from outgoing plane 51a with the dot pattern configuration of regulation.Not having in the ink-jet method of master, can shorten the needed time of dot pattern that determines afore mentioned rules.Consequently, can manufacture more efficiently LGP 50.

Next, the shape of the lens that form by above-mentioned ink-jet method printing lens portion 52 in the situation that is described.Here, the lyophoby processing that changes respectively on one side the number of times (drippage number of times) of the ink dripping in order to form a lens section 52, implements becoming the face at the back side of main part 51, observes the shape of the lens section 52 in situation about forming according to following condition on one side.

Condition 1: the fixing drippage of the face number of times of having implemented lyophoby coating is printed

Condition 2: change drippage number of times while print to having implemented the face of lyophoby coating

Condition 3: the face of fluoridizing plasma treatment (Off Star プ ラ ズ マ processing) to having applied changes drippage number of times while prints

Observe respectively according to above-mentioned condition 1～3 and print the lens section 52 obtaining, calculate respectively aspect ratio [h _iIa/ w _iIaand sharp degree k _iIa.Utilize the result of calculation of this observation to be shown in Figure 11 (a)～(c).Figure 12 is that the result of calculation that the utilization separately of Figure 11 (a)～(c) is observed to gained is summed up a figure in table.According to the aspect ratio [h shown in Figure 12 _iIa/ w _iIa] and sharp degree k _iIadistribution known, the shape of the lens section 52 printing by ink-jet method becomes the aspect ratio [h representing in the frame shown in Figure 12 _iIa/ w _iIaand sharp degree k _iIascope in shape.

In addition, can obtain according to the result of calculation of utilizing above-mentioned observation, by sharp degree k _aand aspect ratio [h _iIa/ w _iIaregulation lens shape and with respect to the radius of curvature (r of width _iI/ w _iIa) relation and by sharp degree k _aand aspect ratio [h _iIa/ w _iIathe lens shape of regulation and the bottom angle γ with respect to width _iIrelation be shown in Figure 13 and Figure 14, Figure 15 and Figure 16.Figure 13 and Figure 15 show sharp degree k _iIait is the scope more than 0.1 and below 0.9.Figure 14 and Figure 16 show sharp degree k _iIafor the scope more than-0.9 and below 0.In Figure 13～Figure 16, with hypographous unit and by the aspect ratio [h in the frame of Figure 12 _iIa/ w _iIa] and sharp degree k _iIathe lens shape correspondence of regulation.

According to Figure 12～Figure 16, can illustrate the shape of the lens section 52 that can print by ink-jet method.Particularly, can be formed in the shape of the lens section 52 exemplifying in above-mentioned embodiment, the i.e. shape of any regulation of the combination in chart as shown in Figure 9.In other words, the shape of the lens section 52 of any regulation of the combination in chart as shown in Figure 9 can be printed by ink-jet method, so can be described as the shape that can easily form when in the time that the main part 51 of LGP 50 forms lens section 52.

In addition, the outer shape of lens section 52 is at the aspect ratio (h shown in the chart by Fig. 9 _iIa/ w _iIa), with respect to the radius of curvature (r of width _iI/ w _iIa) and bottom angle γ _iIthe scope of shape of combination regulation in, in the time that the outline line that makes lens section 52 becomes the represented conic section of above-mentioned formula (2), can further append the parameter k that represents sharp degree _iIacondition.Below, for the aspect ratio ［ h shown in the chart of Figure 17 _iIa/ w _iIain each and illustrate particularly the condition of the satisfied outer shape of lens section 52.

(1) 0.07≤h _iIa/ w _iIathe situation of < 0.09

The outer shape of lens section 52 is satisfied-0.15≤k _iIa≤ 0.45 shape.

(2) 0.09≤h _iIa/ w _iIathe situation of < 0.11

The outer shape of lens section 52 is satisfied-0.15≤k _iIa≤ 0.55 shape.

(3) 0.11≤h _iIa/ w _iIathe situation of < 0.13

The outer shape of lens section 52 is satisfied-0.15≤k _iIa≤ 0.55 shape.

(4) 0.13≤h _iIa/ w _iIathe situation of < 0.15

The outer shape of lens section 52 is satisfied-0.65≤k _iIa≤ 0.55 shape.

(5) 0.15≤h _iIa/ w _iIathe situation of < 0.17

The outer shape of lens section 52 is satisfied-0.65≤k _iIa≤ 0.65 shape.

(6) 0.17≤h _iIa/ w _iIathe situation of < 0.19

The outer shape of lens section 52 is satisfied-0.65≤k _iIa≤ 0.65 shape.

(7) 0.19≤h _iIa/ w _iIathe situation of < 0.21

The outer shape of lens section 52 is satisfied-0.95≤k _iIa≤ 0.65 shape.

(8) 0.21≤h _iIa/ w _iIathe situation of < 0.23

The outer shape of lens section 52 is satisfied-0.95≤k _iIa≤ 0.45 shape.

(9) 0.23≤h _iIa/ w _iIathe situation of < 0.25

The outer shape of lens section 52 is satisfied-0.95≤k _iIa≤ 0.45 shape.

(10) 0.25≤h _iIa/ w _iIathe situation of < 0.27

The outer shape of lens section 52 is satisfied-0.95≤k _iIa≤ 0.05 shape.

(11) 0.27≤h _iIa/ w _iIathe situation of < 0.29

The outer shape of lens section 52 is satisfied-0.75≤k _iIa≤-0.55 shape.

(12) 0.29≤h _iIa/ w _iIathe situation of < 0.31

The outer shape of lens section 52 is satisfied-0.75≤k _iIa≤-0.55 shape.

Here, for said lens shape, be illustrated as the lens section 52 that can print by ink-jet method, but as mentioned above, also can form by extrusion modling, injection mo(u)lding etc. except ink-jet method the lens section 52 of said lens shape.In this case, also can form the shape except the scope shown in the chart of Fig. 9 and Figure 17.

In addition, also can be formed with by extrusion modling, injection mo(u)lding etc. manufactures the LGP 50 of lens section 52 and convex strip portions 55.In this case, the material of lens section 52 and convex strip portions 55 is identical with the material of main part 51.In addition, the LGP 50 that is formed with the main part 51 as plate body, convex strip portions 55 and the lens section 52 that possess convex strip portions 55 also can be manufactured by the method that the sheet material being for example made up of translucent material (or transparent material) is cut.

Next,, take the situation that a part for planar light source device 30 shown in Fig. 1 is applied to transmission image display device 10 as example, the action effect of above-mentioned LGP 50 is described.

If the point source of light 61 that light source portion 60 is had is luminous, from the light of point source of light 61 from being incident to LGP 50 with the side 50a of the opposed LGP 50 of point source of light 61.The light that is incident to LGP 50 is propagated in LGP 50 inner total reflections simultaneously.If the light in LGP 50 interior propagation is incident to lens section 52, reflect under the condition beyond total reflection condition at the interior light of lens section 52.Therefore, penetrate from outgoing plane 51a at the light of lens section 52 internal reflections.Owing to being formed with convex strip portions 55 at outgoing plane 51a, thus with the LGP ratio that does not form convex strip portions at outgoing plane, can improve light penetrate efficiency.Improve by above-mentioned effect brightness.And, in the transmission image display device 10 of present embodiment, on LGP 50, be provided with transmission type image display part 20, so transmission type image display part 20 is thrown light on the higher light of brightness.Consequently, can realize the raising of the brightness of the image being shown by transmission type image display part 20.

Next, according to analog result, the light ejaculation efficiency of the LGP 50 that is formed with lens section 52 and convex strip portions 55 is described than existing leaded light plate hight this point.But the present invention is not limited to above-mentioned simulation.

Figure 18 is the schematic diagram that represents simulation model.For convenience of description, to the inscape corresponding with the inscape shown in Fig. 1 as LGP 50 _mmark M records like this.Simulation as shown in figure 18, respectively with the LGP 50 of the evaluation object as describing in detail below _m side 50 _ma (51 _mc), 50 _mb (51 _md) opposed position configuration point source of light 61 _m, 61 _mand at LGP 50 _mbelow dispose as reflecting part 70 _mthe model of reflector plate in, use Ray Tracing to calculate light and penetrate efficiency E.

Simulated conditions are as described below.

LGP 50 _mconstituent material: there is convex strip portions 55 _m main part 51 _mand lens section 52 _mall suppose it is PMMA (refractive index: 1.49)

LGP 50 _mplan view shape (from thickness of slab direction observe shape): rectangle

LGP 50 _mthe length W1:540mm on long limit

LGP 50 _mthe length W2:20mm of minor face

Main part 51 _mthickness t: 3mm

LGP 50 _m lens section 52 _mtop ends 52 _ma and reflecting part 70 _mbetween distance: 0.1mm

Reflecting part 70 _m: the reflection characteristic that supposition is identical with the white reflecting plate taking out from the back light unit using Sony Corp's system " KDL40EX7 "

From point source of light 61 _mthe light wavelength penetrating: be assumed to 550nm

Point source of light 61 _mwith LGP 50 _mdistance: 0.05mm

In addition, at main part 51 _m side 51 _me and side 51 _mf supposes periodic boundary condition., in side 51 _me and 51 _mf, light all reflects and returns to LGP 50 _min.Like this, at LGP 50 _mshort side direction (Y direction) periodic boundary condition is set, thereby implement the simulation of the in fact unlimited LGP of length of supposition short side direction.

Under such condition, calculate from outgoing plane 51 _mthe amount E of whole ejaculation light of a _owith respect to the LGP 50 inciding as the object of evaluating _mthe amount E of light _iratio, penetrate efficiency E (=E thereby obtain light _o/ E _i).

Next, to the LGP 50 as the object of evaluating _mdescribe.Using the LGP 50 as evaluation object _mbe assumed to: outgoing plane 51 _mthe shape of a side and the back side 51 _mthe shape of b side is that the combination shown in following table 1 is 12 kinds of LGPs 50 of example 1～example 12 _m.

［ table 1 ］

< outgoing plane 51 _ma side >

Suppose the LGP 50 of example 1～example 6 _mat outgoing plane 51 _ma side is formed with the biconvex lens 55 as convex strip portions _m.Particularly, be assumed to: as shown in figure 18, at the biconvex lens 55 of short side direction adjacency _mthe mode of opening the interval of regulation with sky each other configures.Here, by biconvex lens 55 _mwidth w _iabe set as 475 μ m, by biconvex lens 55 _minterval S is each other set as 25 μ m, by main part 51 _m outgoing plane 51 _mmultiple biconvex lens 55 of a _mcoverage rate be set as 95%.

The LGP 50 of example 7～example 9 _mat outgoing plane 51 _ma side is formed with the prism 55 as convex strip portions _m.Particularly, be assumed to: the biconvex lens 55 that replaces Figure 18 _mand the prism 55 shown in formation Fig. 7 _m, at the prism 55 of short side direction adjacency _mconfigure in mode very close to each other each other.Here, by prism 55 _mwidth w _iabe set as 500 μ m, by prism 55 _minterval S is each other set as 0 μ m, by main part 51 _m outgoing plane 51 _m multiple prisms 55 of a _mcoverage rate be set as 100%.

By biconvex lens 55 _mand prism 55 _msection shape while being defined as the represented conic section of following formula (3), suppose aspect ratio h _ia/ w _iaand sharp degree k _iabe respectively the situation shown in table 1.

［ formula 3 ］

$v_I\left(u_I\right)=h_{\mathrm{Ia}}-\frac{{{8h}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}{1-k_{\mathrm{Ia}}+\sqrt{{{(1-k_{\mathrm{Ia}})}^2+{16k}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}}---\left(3\right)$

On the other hand, be assumed to the LGP 50 in example 10～example 12 _m outgoing plane 51 _ma side does not form the biconvex lens 55 as convex strip portions _mor prism 55 _m, outgoing plane 51 _ma general planar.

The < back side 51 _mb side >

At the LGP 50 of example 1～example 12 _mthe back side 51 _mb side disposes the lenticule 52 as lens section at certain intervals _m.Particularly, overleaf 51 _mb sets the square lattice being formed by multiple square arrangement, is lens section 52 of each square configuration at the component unit of square lattice _m.In addition, lenticule 52 _mat outgoing plane 51 _ma side makes multiple biconvex lens 55 _mbe configured with coverage rate 100%, the coverage rate obtaining so that the quantity of light emission uniformity reaches more than 95% mode optimization distributes and is configured.Figure 19 is the lenticule 52 in example 1～example 6 _mcoverage rate distribute example, transverse axis represents apart from LGP 50 _mthe distance (mm) of central part, the longitudinal axis represents coverage rate (%).Figure 20 is the lenticule 52 in example 7～example 12 _mcoverage rate distribute example, transverse axis represents apart from LGP 50 _mthe distance (mm) of central part, the longitudinal axis represents coverage rate (%).According to Figure 19 and Figure 20, in arbitrary example, a lenticule 52 _mwith respect to the back side 51 _mthe coverage rate of the square lattice at the X-direction central part place of b is all 74.61%.

By lenticule 52 _msection shape while being defined as the represented conic section of following formula (4), aspect ratio h _iIa/ w _iIaand sharp degree k _iIait is respectively the situation shown in table 1.

［ formula 4 ］

$v_{\mathrm{II}}\left(u_{\mathrm{II}}\right)=h_{\mathrm{IIa}}-\frac{{{8h}_{\mathrm{IIa}}\left(\frac{u_{\mathrm{II}}}{w_{\mathrm{IIa}}}\right)}^2}{1-k_{\mathrm{IIa}}+\sqrt{{{(1-k_{\mathrm{IIa}})}^2+{16k}_{\mathrm{IIa}}\left(\frac{u_{\mathrm{II}}}{w_{\mathrm{IIa}}}\right)}^2}}---\left(4\right)$

Next, to point source of light 61 _mbe described in detail.Point source of light 61 _m, 61 _mat LGP 50 _mshort side direction dispose respectively two, distance each end distance L 1 be 5mm, mutual light source interval L2 is 10mm.Point source of light 61 _mit is the big or small area source that laterally length of (depth direction) is 5.5mm, longitudinally the length of (thickness direction of LGP) is 2mm.

Figure 21 represents point source of light 61 _mthe accompanying drawing of an example of directional property (light distribution characteristic).The transverse axis of Figure 21 represent to penetrate angle θ (°), the longitudinal axis represent with maximum ejaculation luminous intensity standardization standardization penetrate luminous intensity.In the present embodiment, θ=0 is corresponding with the X-direction of Fig. 1.By point source of light 61 _mbe assumed to the light source of so-called lambert (Lambertian) type, point source of light 61 _mexample comprise light emitting diode.The light source of lambert's type has following feature: the maximum that penetrates luminous intensity maximum penetrates near the ejaculation angle (frontal) 0 ° of luminous intensity, along with the gradient from frontal (ejaculation angle) becomes monotone decreasing greatly and roughly.Directional property in situation about spreading completely in the PD representation theory in Figure 21, in this simulation, supposes the light source that can obtain this characteristic.

To each LGP 50 of example 1～example 12 _mcarry out the result of above-mentioned simulation gained as shown in the chart of Figure 22.In the chart of Figure 22, represent that the numeric representation light in the hurdle of each analog result penetrates efficiency E (%).

Can confirm: at outgoing plane 51 _ma side is formed with the biconvex lens 55 as convex strip portions _mor prism 55 _meach LGP 50 of example 1～example 9 _mlight penetrate efficiency E, higher than at outgoing plane 51 _ma side does not have the biconvex lens 55 as convex strip portions _mor prism 55 _meach LGP 50 of example 10～situation 12 _mlight penetrate efficiency E.Thus, by outgoing plane 51 _ma side forms biconvex lens 55 _mor prism 55 _mdeng convex strip portions, penetrate efficiency E thereby improve light., can confirm: by penetrating the high LGP 50 of efficiency _mbe used for planar light source device, thereby realize the raising of brightness.

Above, embodiments of the present invention are illustrated, but the present invention is not limited to above-mentioned embodiment and above-mentioned simulation, in the scope of purport that does not depart from invention, can carries out various changes.

In the above-described embodiment, to making to be formed at multiple lens sections 52 on the 51b of the back side at aspect ratio (h as shown in Figure 9 _iIa/ w _iIa), with respect to the radius of curvature (r of width _iI/ w _iIa) and bottom angle γ _iIcombination regulation shape scope and be illustrated.But lens section at least over half is the lens section 52 illustrating in above-mentioned embodiment in the multiple lens sections that are formed on the 51b of the back side.In other words, be formed at back side 51b multiple lens sections can by half be as the first lens portion of said lens portion 52, with remaining half be that the second lens section that does not meet the condition illustrating in above-mentioned embodiment forms.Can be 6:4 as the quantity of first lens portion of lens section 52 and the ratio of the quantity of above-mentioned the second lens section.

In addition, the shape of lens section 52 preferably have the section of lens section 52 as illustrated in Fig. 8 and back side 51b angulation from the bottom side of lens section 52 towards top ends side and the shape of monotone decreasing.But, if lens section 52 has by the h shown in the chart of Fig. 9 _iIa/ w _iIa, r _iI/ w _iIaand γ _iIthe shape of shown combination regulation, the section of lens section 52 and back side 51b angulation also can be towards top ends 52a sides and monotone decreasing.

And the allocation position of light source portion 60 is not limited to two positions, place.For example, light source portion 60 also can be disposed at a position, place.In this case, light source portion 60 is disposed at the side in the side 51c shown in Fig. 1 and side 51d.Can attach the reflection tape such as minute surface adhesive tape, white diffusion adhesive tape for preventing light leak from opposed the opposing party's in side of a side of the light incident of light source portion 60 side with confession.

In addition, in above-mentioned simulation, show the example of the point source of light 61 of the directional property in the situation in theory with diffusion completely, but the planar light source device 30 of present embodiment, transmission image display device 10 are not limited to this.For example, as shown in figure 21, as long as thering is the point source of light of directional property of following lambert's type: meet with respect to represent diffusion completely directional property PD and penetrate when angle is 30 °, depart from-0.6%, penetrating when angle is 60 °, depart from-11.0% curve PD1 (representing with dotted line in Figure 21), with penetrating when angle is 30 ° the ejaculation angle and the standardization activity that depart from 6.9%, in the time that ejaculation angle is 60 °, depart from the region between 16.4% curve PD2 (dotting in Figure 21).

In addition, in the above-described embodiment, as an example of the outer shape of convex strip portions 55, enumerating can be by (I) aspect ratio (h _ia/ w _ia), (II) with respect to the radius of curvature (r of width _i/ w _ia) and ( _iII) bottom angle γ _ithe example of definite outer shape is illustrated.In addition, except this condition, also the situation of the conic section that the outline line of convex strip portions 55 can be defined as to following formula (5) expression is illustrated.But the present invention is not limited to this.

［ formula 5 ］

$v_I\left(u_I\right)=h_{\mathrm{Ia}}-\frac{{{8h}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}{1-k_{\mathrm{Ia}}+\sqrt{{{(1-k_{\mathrm{Ia}})}^2+{16k}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}}---\left(5\right)$

For example,, when setting u with the orthogonal section of the bearing of trend of convex shaped part 55 _iv _icoordinate system is (by u _idirection of principal axis is set as X-direction, by v _idirection of principal axis is set as Z-direction) time, can be with the v that meets following formula (6) _i(u _i) represent the section shape of convex strip portions 55.

［ formula 6 ］

0.95×v _I0(u _I)≤v _I(u _I)≤1.05×v _I0(u _I)…(6)

Wherein, in formula (6), v _i0(u _i) meet:

［ formula 7 ］

$v_{I0}\left(u_I\right)=h_{\mathrm{Ia}}-\frac{{{8h}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}{1-k_{\mathrm{Ia}}+\sqrt{{{(1-k_{\mathrm{Ia}})}^2+{16k}_{\mathrm{Ia}}\left(\frac{u_I}{w_{\mathrm{Ia}}}\right)}^2}}---\left(7\right)$

Formula (7) is identical with above-mentioned formula (1), w _iathat convex strip portions 55 is at u _iaxial length, h _iabecome v with making convex strip portions 55 _i0(u _i) shown in the situation of shape under both ends 55b, the 55b of convex strip portions 55 between maximum height correspondence.K _iait is the parameter that represents the sharp degree of the top ends 55a of convex strip portions 55.For example, at sharp degree k _iabe 0 o'clock, the profile of convex strip portions 55 is parabolic shape, at sharp degree k _iabe 1 o'clock, the profile of convex strip portions 55 is prism shape, at sharp degree k _iafor-1 o'clock, the profile of convex strip portions 55 was the shape that ellipse is cut into half.

In addition, in the present application, the outer shape that is arranged at the convex strip portions 55 of outgoing plane side can be formed as the outer shape of convex strip portions shown below 155.; with multiple convex strip portions 155 separately in the orthogonal section of bearing of trend; the length along this outline line of point P from summit (top ends) 155a of the section of this convex strip portions 155 to outline line is made as to L; the axle at the both ends by convex strip portions 155 is made as to u axle; a section shape of the convex strip portions at P place 155 is made as to α with respect to the gradient (absolute value) of u axle, now can be formed as following shape:

In the scope of-0.20 < L < 0.20, meet following formula (8) and (9),

0＜α…(8)

150≤Δα／ΔL＜260…(9)

In the scope of-0.65 < L≤-0.20 and the scope of 0.20≤L < 0.65, meet following formula (10) and (11),

0≤α…(10)

0≤Δα／ΔL＜30…(11)

In the scope of-1.00 < L≤-0.65 and the scope of 0.65≤L < 1.00, meet following formula (12) and (13).

0＜α…(12)

5≤Δα／ΔL＜75…(13)

Be formed in the LGP of light emergence face at the multiple convex strip portions 155 that have α and Δ α/Δ L and meet the section shape of above-mentioned condition, the light that incides the light entrance face of LGP is easily propagated along the bearing of trend of convex strip portions 155.Therefore, when light suppresses the diffusion of light in the time that the incoming position of light is propagated in LGP, so can reduce crosstalk (cross talk).In addition, L is 0 in the axial central authorities of u, and more from central authorities towards right front enter more increase (L>0), more from central authorities towards left front enter more reduce (L < 0).

The outer shape of convex strip portions 155 preferably meets following formula (14) in the scope of-0.20 < L < 0.20.

170≤Δα／ΔL＜240…(14)

The outer shape of convex strip portions 155 meets following formula (15) in preferably in the scope of-0.65 < L≤-0.20 and the scope of 0.20≤L < 0.65.

0≤Δα／ΔL＜20…(15)

The outer shape of convex strip portions 155 preferably meets following formula (16) in the scope of-1.00 < L≤-0.65 and the scope of 0.65≤L < 1.00.

10≤Δα／ΔL＜60…(16)

The outer shape of convex strip portions 155 is preferably in the time the width of convex strip portions 155 being made as to wa, the maximum height of convex strip portions 155 is made as to ha, and the aspect ratio (ha/wa) of convex strip portions 155 is more than 0.3 and less than 0.5.

Using the example of the outer shape of Figure 23～Figure 27 to such convex strip portions 155 is that embodiment A1～A5 describes.Figure 23～Figure 27 is the accompanying drawing that represents the example of the section shape orthogonal with the bearing of trend of convex strip portions.Figure 23 represents embodiment A1, and Figure 24 represents embodiment A2, and Figure 25 represents embodiment A3, and Figure 26 represents embodiment A4, and Figure 27 represents embodiment A5.In Figure 23～Figure 27, will set uv coordinate system as u axle with the orthogonal direction of the bearing of trend of convex strip portions 155.In this uv coordinate system, the section shape of convex strip portions 155 has both ends 155b, 155b on u axle.In uv coordinate system, both ends 155b, the 155b Jian center of v axle from u axle passed through.In the mode shown in Fig. 1 and Fig. 2, u direction of principal axis is Y direction.In addition, v direction of principal axis is Z-direction.

In uv coordinate system, the section shape of convex strip portions 155 meets following formula (17)～(22).Wherein, convex strip portions 155 is made as to w in the axial position of u, the section shape of the convex strip portions 155 at w place, position is made as to α with respect to the gradient of u axle.With the orthogonal section of the bearing of trend of convex strip portions 155 in, the length along this outline line of the some P from the summit 155a of the section of this convex strip portions 155 to outline line is made as to L.Point P is above-mentioned position w in the axial position of u, and gradient α (absolute value) is the gradient of a P.Δ α/Δ L is that the variable quantity of α is with respect to the ratio of the variable quantity of L.Gradient α is less angle (0≤α≤90) in tangent line and the u axle of the section shape of the convex strip portions 155 located of position w (some P) angle of intersecting.

At u direction of principal axis, the center O from convex strip portions 155 (0,0) is made as to 1 to the length of end 155b.The position of the end 155b of convex strip portions 155 is made as w=-1,1.Position w more advances to the right and more increases (w>0) from center O, more advances left from center O and more reduces (w < 0).In addition, at v direction of principal axis, height corresponding with the length of end 155b from the center O of convex strip portions 155 is made as to h _a.Position w is the width w by convex strip portions 155 _astandardized value is with respect to width w _athe value of ratio performance position.

The section shape of convex strip portions 155, in the first interval A (scope of 0.20 < L < 0.20), meets following formula (17) and (18).

0＜α…(17)

150≤Δα／ΔL＜260…(18)

The section shape of convex strip portions 155 is at the first interval A, and gradient α increases.In other words,, more away from center O, gradient α is larger.

The section shape of convex strip portions 155, in the second interval B (scope of the scope of 0.65 < L≤-0.20 and 0.20≤L < 0.65), meets following formula (19) and (20).

0≤α…(19)

0≤Δα／ΔL＜30…(20)

The section shape of convex strip portions 155 is in the second interval B, and gradient α increases or do not change.In other words,, more away from center O, gradient α is larger or constant.

The section shape of convex strip portions 155, in the 3rd interval C (scope of the scope of 1.00 < L≤-0.65 and 0.65≤L < 1.00), meets following formula (21) and (22).

0＜α…(21)

5≤Δα／ΔL＜75…(22)

The section shape of convex strip portions 155 is at the 3rd interval C, and gradient α increases.In other words,, more away from center O, gradient α is larger.

At the first interval A, Δ α/Δ L can meet following formula (23).

170≤Δα／ΔL＜240…(23)

In the second interval B, Δ α/Δ L can meet following formula (24).

0≤Δα／ΔL＜20…(24)

At the 3rd interval C, Δ α/Δ L can meet following formula (25).

10≤Δα／ΔL＜60…(25)

Figure 28 is the accompanying drawing that represents the part of the section shape of convex strip portions 155.Any two points in the profile of convex strip portions 155 is being made as to P ₁, P ₂situation under, Δ L=L ₂-L ₁(wherein, L ₂>L ₁), Δ α=α ₂-α ₁(wherein, α ₂>=α ₁).Wherein, L ₁the some P on outline line ₁position, α ₁a P ₁gradient (angle of intersecting with u axle).Equally, L ₂the some P on outline line ₂position, α ₂a P ₂gradient (angle of intersecting with u axle).

Figure 29～Figure 31 is the figure that represents the relation of position L on the outline line of section shape of convex strip portions 155 and inclined angle alpha.In Figure 29～Figure 31, transverse axis represents position L, the longitudinal axis represent inclined angle alpha [deg ］.At transverse axis, L=0 represents the outline line Shang center of convex strip portions 155.The section shape of convex strip portions 155 forms summit (top ends 155a) and inclined angle alpha=0 of convex strip portions 155 at L=0 place.For position L, the position of the end 155b of the width of convex strip portions 155 (u direction of principal axis) is made as to L=1, represent with ratio.L=0.5 represents the position of the centre of center O and end 155b.In Figure 29～Figure 31, show the inclined angle alpha of L in the time of the scope of 0≤L≤1, the value of the inclined angle alpha of L in the time of the scope of-1≤L≤0 is the value of turning back of the value of 0≤L≤1 (folding り returns value).

Figure 29 (a) represents embodiment A1, and Figure 29 (b) represents embodiment A2, and Figure 30 (a) represents embodiment A3, and Figure 30 (b) represents embodiment A4, and Figure 31 represents embodiment A5.The section shape of the convex strip portions 155 of embodiment A1～A5 increases in the first interval A inclined angle alpha.That is, more leave towards end 155b (L=1) side from center O, inclined angle alpha is larger.

The section shape of the convex strip portions 155 of embodiment A1 increases or does not change in the second interval B inclined angle alpha.Particularly, the section shape of the convex strip portions 155 of embodiment A1 does not change but constant at the scope introversion oblique angle α of 0.20≤L < 0.60.The section shape of the convex strip portions 155 of embodiment A1 increases at the scope introversion oblique angle α of 0.60≤L < 0.65.

The section shape of the convex strip portions 155 of embodiment A2～A5 increases in the second interval B inclined angle alpha.That is, more leave towards end 155b (L=1) side from center O, inclined angle alpha is larger.

The section shape of the convex strip portions 155 of embodiment A1～A5 increases in the 3rd interval C inclined angle alpha.That is, more leave towards end 155b (L=1) side from center O, inclined angle alpha is larger.

Figure 32 represents the line segment length L of section shape of convex strip portions 155 and the figure of the relation of Δ α/Δ L.In Figure 32, transverse axis represents line segment length L, and the longitudinal axis represents Δ α/Δ L.In Figure 32, show the Δ α/Δ L of L in the time of the scope of 0≤L≤1, but the value of the Δ α/Δ L of L in the time of the scope of-1≤L≤0 is the value of turning back of the value of 0≤L≤1.The line segment length L is here by the ratio being made as to the length along outline line of end 155b from summit (top ends) 155a the situation of " 1 " is represented.

The section shape of the convex strip portions 155 of embodiment A1～A5 is at the first interval A, and Δ α/Δ L is more than 150 and less than 260.The section shape of the convex strip portions 155 of embodiment A1～A5 is in the second interval B, and Δ α/Δ L is more than 0 and less than 30.The section shape of the convex strip portions 155 of embodiment A1～A5 is at the 3rd interval C, and Δ α/Δ L is more than 5 and less than 75.

(aspect ratio)

The width w of the axial convex strip portions 155 of u _aconventionally the distance that the spot light that connects near is 61 is little.Width w _aexample be 50 μ m～2000 μ m, be preferably 100 μ m～1000 μ m, more preferably 200 μ m～800 μ m.H _awith the both ends 155b of convex strip portions 155, the maximum height correspondence between 155b.Aspect ratio (the h of convex strip portions 155 _a/ w _a) be maximum height h _awith respect to the width w of convex strip portions 155 _aratio.The aspect ratio of convex strip portions 155 is more than 0.3 and less than 0.5.

The section shape of multiple convex strip portions 155 is roughly the same 155 of convex strip portions.But, multiple convex strip portions 155 section shape separately as long as the section shape that meets above-mentioned formula (17)～(22) also can be different.

The LGP with the convex strip portions 155 of above-mentioned formation is for example not limited to monolayer constructions will, can be also multi-ply construction.In the present embodiment, the thickness of slab that has a LGP of convex strip portions 155 is the thickness of slab of main part.The thickness of slab of main part is the distance between top (top ends) 155a and the back side of main part of convex strip portions 155, is generally 0.5mm～8mm, is preferably 1mm～6mm, more preferably 1.5mm～4mm.

In addition, in the present application, the outer shape of convex strip portions 55 that is arranged at outgoing plane side can be formed as to the outer shape of convex strip portions shown below 255.; with the orthogonal section of multiple convex strip portions 255 bearing of trend separately in; the length along this outline line of point P from summit (top ends) 255a of the section of this convex strip portions 255 to outline line is made as to L; the axle at the both ends by convex strip portions 255 is made as to u axle; a section shape of the convex strip portions at P place 255 is made as to α with respect to the gradient (absolute value) of u axle; now, can be formed as following shape:

In the scope of-0.20 < L < 0.20, meet following formula (26) and (27),

0＜α…(26)

60≤Δα／ΔL＜140…(27)

In the scope of-0.65 < L≤-0.20 and the scope of 0.20≤L < 0.65, meet following formula (28) and (29),

0≤α…(28)

0≤Δα／ΔL＜30…(29)

In the scope of-1.00 < L≤-0.65 and the scope of 0.65≤L < 1.00, meet following formula (30) and (31).

0＜α…(30)

10≤Δα／ΔL＜110…(31)

Be formed in the LGP of light emergence face at the multiple convex strip portions 255 that have α and Δ α/Δ L and meet the section shape of above-mentioned condition, the light that incides the light entrance face of LGP is easily propagated along the bearing of trend of convex strip portions 255.Therefore, in the time that light is propagated in LGP from the incoming position of light, suppress the diffusion of light, crosstalk so can reduce.In addition, for L, axial u central authorities are made as to 0, more enter more to increase (L > 0) towards right front from central authorities, more enter more to reduce (L < 0) from central authorities towards left front.

The outer shape of convex strip portions 255 preferably meets following formula (32) in the scope of-0.20 < L < 0.20.

80≤Δα／ΔL＜120…(32)

The outer shape of convex strip portions 255 preferably meets following formula (33) in the scope of-0.65 < L≤-0.20 and the scope of 0.20≤L < 0.65.

0≤Δα／ΔL＜20…(33)

The outer shape of convex strip portions 255 preferably meets following formula (34) in the scope of-1.00 < L≤-0.65 and the scope of 0.65≤L < 1.00.

30≤Δα／ΔL＜90…(34)

The outer shape of convex strip portions 255 is preferably being made as w by the width of convex strip portions 255 _a, the maximum height of convex strip portions 255 is made as to h _atime, the aspect ratio (ha/wa) of convex strip portions 255 is more than 0.15 and less than 0.3.

Using the example of the outer shape of Figure 33～Figure 37 to such convex strip portions 255 is that embodiment B1～B5 describes.Figure 33～Figure 37 is the accompanying drawing that represents the example of the section shape orthogonal with the bearing of trend of convex strip portions.Figure 33 represents embodiment B1, and Figure 34 represents embodiment B2, and Figure 35 represents embodiment B3, and Figure 36 represents embodiment B4, and Figure 37 represents embodiment B5.In Figure 33～Figure 37, set uv coordinate system by being made as u axle with the orthogonal direction of the bearing of trend of convex strip portions 255.In this uv coordinate system, the section shape of convex strip portions 255 has both ends 255b, 255b on u axle.In uv coordinate system, v axle is by both ends 255b, 255b Jian center on u axle.In the mode shown in Fig. 1 and Fig. 2, u direction of principal axis is Y direction.In addition, v direction of principal axis is Z-direction.

In uv coordinate system, the section shape of convex strip portions 255 meets following formula (35)～(40).Wherein, axial the u of convex strip portions 255 position is made as to w, the section shape of the convex strip portions 255 at w place, position is made as to α with respect to the gradient of u axle.With the orthogonal section of the bearing of trend of convex strip portions 255 in, the length along this outline line of the some P from the summit of the section of this convex strip portions 255 to outline line is made as to L.Δ α/Δ L is that the variable quantity of α is with respect to the ratio of the variable quantity of L.Gradient α is less angle (0≤α≤90) in tangent line and the u axle of the section shape of the convex strip portions 255 located of position w (some P) angle of intersecting.

At u direction of principal axis, the center O from convex strip portions 255 (0,0) is made as to 1 to the length of end 255b.The position of the end 255b of convex strip portions 255 is w=-1,1.Position w more advances to the right and more increases (w>0) from center O, more advances left from center O and more reduces (w < 0).In addition, at v direction of principal axis, height corresponding with the length of end 255b from the center O of convex strip portions 255 is made as to h _a.Position w is the width w by convex strip portions 255 _astandardized value is with respect to width w _athe value of ratio performance position.

The section shape of convex strip portions 255 meets following formula (35) and (36) at the first interval A (scope of 0.20 < L < 0.20).

0＜α…(35)

60≤Δα／ΔL＜140…(36)

The section shape of convex strip portions 255 is at the first interval A, and gradient α increases.In other words,, more away from center O, gradient α is larger.

The section shape of convex strip portions 255 meets following formula (37) and (38) in the second interval B (scope of the scope of 0.65 < L≤-0.20 and 0.20≤L < 0.65).

0≤α…(37)

0≤Δα／ΔL＜30…(38)

The section shape of convex strip portions 255 is in the second interval B, and gradient α increases or do not change.In other words,, more away from center O, gradient α is larger or constant.

The section shape of convex strip portions 255, in the 3rd interval C (scope of the scope of 1.00 < L≤-0.65 and 0.65≤L < 1.00), meets following formula (39) and (40).

0＜α…(39)

10≤Δα／ΔL＜110…(40)

The section shape of convex strip portions 255 is at the 3rd interval C, and gradient α increases.In other words,, more away from center O, gradient α is larger.

At the first interval A, Δ α/Δ L also can meet following formula (41).

80≤Δα／ΔL＜120…(41)

In the second interval B, Δ α/Δ L also can meet following formula (42).

0≤Δα／ΔL＜20…(42)

At the 3rd interval C, Δ α/Δ L also can meet following formula (43).

30≤Δα／ΔL＜90…(43)

Figure 38 is the accompanying drawing that represents the part of the section shape of convex strip portions 255.By in the profile of convex strip portions 255 arbitrarily 2 be made as P ₁, P ₂situation under, Δ L=L ₂-L ₁(wherein, L ₂>L ₁), Δ α=α ₂-α ₁(wherein, α ₂>=α ₁).Wherein, L ₁the some P on outline line ₁position, α ₁a P ₁gradient (angle of intersecting with u axle).Equally, L ₂the some P on outline line ₂position, α ₂a P ₂gradient (angle of intersecting with u axle).

Figure 39～Figure 41 is the figure that represents the relation of position L on the outline line of section shape of convex strip portions 255 and inclined angle alpha.In Figure 39～Figure 41, transverse axis represents position L, the longitudinal axis represent inclined angle alpha [deg ］.On transverse axis, L=0 represents the outline line Shang center of convex strip portions 255.The section shape of convex strip portions 255 forms the summit (top ends 255a) of convex strip portions 255 at L=0 place, and inclined angle alpha=0.For the L of position, the position of the end 255b of the width of convex strip portions 255 (u direction of principal axis) is made as to L=1, represent with ratio.L=0.5 represents the position of the centre of center O and end 255b.The inclined angle alpha of L in the time of the scope of 0≤L≤1 has been shown in Figure 39～Figure 41, but the value of the inclined angle alpha of L in the time of the scope of-1≤L≤0 is the value of turning back of the value of 0≤L≤1.

Figure 39 (a) represents embodiment B1, and Figure 39 (b) represents embodiment B2, and Figure 40 (a) represents embodiment B3, and Figure 40 (b) represents embodiment B4, and Figure 41 represents embodiment B5.The section shape of the convex strip portions 255 of embodiment B1～B5 increases in the first interval A inclined angle alpha.That is, more leave towards end 255b (L=1) side from center O, inclined angle alpha is larger.

The section shape of the convex strip portions 255 of embodiment B1 increases or does not change in the second interval B inclined angle alpha.Particularly, the section shape of the convex strip portions 255 of embodiment B1 does not change but constant at the scope introversion oblique angle α of 0.20≤L < 0.60.The section shape of the convex strip portions 255 of embodiment B1 increases at the scope introversion oblique angle α of 0.60≤L < 0.65.

The section shape of the convex strip portions 255 of embodiment B2～B5 increases in the second interval B inclined angle alpha.That is, more leave towards end 255b (L=1) side from center O, inclined angle alpha is larger.

The section shape of the convex strip portions 255 of embodiment B1～B5 increases in the 3rd interval C inclined angle alpha.That is, more leave towards end 255b (L=1) side from center O, inclined angle alpha is larger.

Figure 42 represents the line segment length L of section shape of convex strip portions 255 and the figure of the relation of Δ α/Δ L.In Figure 42, transverse axis represents line segment length L, and the longitudinal axis represents Δ α/Δ L.Figure 42 illustrates the Δ α/Δ L of L in the time of the scope of 0≤L≤1, but the value of the Δ α/Δ L of L in the time of the scope of-1≤L≤0 is the value of turning back of the value of 0≤L≤1.The line segment length L is here with the ratio being made as to the length along outline line of end 255b from summit (top ends) 255a the situation of " 1 " is represented.

The section shape of the convex strip portions 255 of embodiment B1～B5 is at the first interval A, and Δ α/Δ L is more than 60 and less than 160.The section shape of the convex strip portions 255 of embodiment B1～B5 is in the second interval B, and Δ α/Δ L is more than 0 and less than 30.The section shape of the convex strip portions 255 of embodiment B1～B5 is at the 3rd interval C, and Δ α/Δ L is more than 10 and less than 110.

(aspect ratio)

The width w of the axial convex strip portions 255 of u _aconventionally the distance that the spot light that connects near is 61 is little.Width w _aexample be 50 μ m～2000 μ m, be preferably 100 μ m～1000 μ m, more preferably 200 μ m～800 μ m.H _acorresponding with the maximum height between both ends 255b, the 255b of convex strip portions 255.Aspect ratio (the h of convex strip portions 255 _a/ w _a) be maximum height h _awith respect to the width w of convex strip portions 255 _aratio.The aspect ratio of convex strip portions 255 is more than 0.15 and less than 0.30.

The section shape of multiple convex strip portions 255 is roughly the same 255 of convex strip portions.But multiple convex strip portions 255 section shape separately, as long as meeting the section shape of above-mentioned formula (35)～(40), can be also different.

The LGP with the convex strip portions 255 of above-mentioned formation is for example not limited to monolayer constructions will, can be also multi-ply construction.In the present embodiment, the thickness of slab that has a LGP of convex strip portions 255 is the thickness of slab of main part.The thickness of slab of main part is the distance between top (top ends) 255a and the back side of main part of convex strip portions 255, is generally 0.5mm～8mm, is preferably 1mm～6mm, more preferably 1.5mm～4mm.

In addition, in the above-described embodiment, be illustrated at the interior LGP being integrally formed 50 comprising convex strip portions 55, but LGP of the present invention is not limited to this.For example, also can use photopolymer method, be tabular main part with respect to the part on the lower of the datum level 51g than shown in Fig. 4, and forming the part more top than datum level 51g is convex strip portions 55.

In addition, in the transmission image display device 10 shown in Fig. 1, only otherwise depart from purport of the present invention, also can between LGP 50 and transmission type image display part 20, configure other optics.The example of other optics arranging between LGP 50 and transmission type image display part 20 comprises reflective polarizing light separate sheet, light diffusing sheet, micro-lens sheet, bi-convex lens sheet and prismatic lens.

The explanation of Reference numeral

10 ... transmission image display device; 20 ... transmission type image display part; 21 ... liquid crystal cells; 22,23 ... Polarizer; 30 ... planar light source device; 50 ... LGP; 50a, 50b ... side; 51 ... main part; 51a ... outgoing plane (first surface); 51b ... the back side (the second face); 51c, 51d ... side (plane of incidence); 52 ... lens section; 52a ... top ends; 52b ... bottom; 55,155,255 ... convex strip portions (biconvex lens); 60 ... light source portion; 61 ... point source of light; 70 ... reflecting part.

Claims (4)

1. a LGP, is characterized in that, possesses tabular main part and multiple lens section,

Described main part has: first surface, its be formed with multiple along direction extend and with the roughly convex strip portions of configuration side by side in orthogonal direction of a described direction; Second, its opposition side in described first surface; And the plane of incidence, it is with described first surface and second face intersecting and for light incident,

Described multiple lens section is formed at described second of described main part, and protrudes towards a side contrary with a side at described first surface place from described second observation.

2. LGP according to claim 1, is characterized in that,

Described convex strip portions is biconvex lens or prism.

3. a planar light source device, is characterized in that, possesses:

LGP described in claim 1 or 2; And

Light source portion, the described plane of incidence arranged opposite of itself and described LGP, supplies with light to the described plane of incidence.

4. a transmission image display device, is characterized in that, possesses:

LGP described in claim 1 or 2;

Light source portion, the described plane of incidence arranged opposite of itself and described LGP, supplies with light to the described plane of incidence; And

Transmission type image display part, it is arranged at the described first surface side of described LGP, utilizes the optical illumination penetrating from described LGP and shows image.

Images