CN102455458B - Light guide device and backlight module - Google Patents

Abstract

The invention discloses a light guide device and a backlight module; the light guide device comprises a body and a plurality of micro-structure parts, wherein the body has refractive index n, and comprises a light-emitting surface, a basic surface and at least one light-entrance surface; the distance between the basic surface and the light-emitting surface is the thickness T; the micro-structure parts are arranged on the basic surface; each micro-structure part has the width P and comprises a first distance L1 and a second distance L2; and the distance between every two micro-structure parts is S. In the invention, the light guide device meets the relational expression shown in the specifications, so that the light guide device and the backlight module used by the light guide device have the best optical uniformity degree.

Description

Guiding device and backlight module

Technical field

The present invention relates to a kind of guiding device and use the backlight module of this guiding device, particularly a kind of have the guiding device of leaded light and light diffusion effect and the backlight module of use thereof simultaneously.

Background technology

In recent years, traditional cathode-ray tube display (CRT monitor that namely is commonly called as) is replaced by LCD gradually, main cause is that the radiant quantity that LCD discharges is far smaller than CRT monitor, in addition, LCD is in the existing reduction significantly of this manufacturing cost in several years, and this also is the reason that LCD becomes the main flow in TV or computer screen market gradually.

Generally speaking, LCD includes a liquid crystal panel and a backlight module; In undersized LCD, excessive or cost is too high for fear of the thickness of LCD, can use the backlight module of side type usually.Usually, side type backlight module can comprise a guiding device and at least one light source, this light source is arranged on the side of this guiding device, make the emitted light of this light source, after its optical path is entered by the side of guiding device, light is in the guiding device internal delivery, and the wherein one side from guiding device penetrates again.Wherein, the most important effect of guiding device is the local reflex of setting by microstructure or reflection site and directing light penetrates light equably from the surface of this guiding device.

Yet because structural restriction, the emitted light of this guiding device can be light and dark " blanking bar phenomenon " usually, makes that the uniformity coefficient of whole backlight module is not good, influences user's vision impression.

Summary of the invention

The purpose of the embodiment of the invention is the defective at above-mentioned prior art, and a kind of guiding device is provided, and the light that guiding device is penetrated has preferable uniformity coefficient, eliminates " the blanking bar phenomenon " of backlight module, and then promotes the optical effect of LCD.

The technical scheme taked of the present invention is to achieve these goals:

The invention provides a kind of guiding device, it comprises a body and a plurality of microstructure portion, this body has refractive index n, and comprise an exiting surface, a fundamental plane and at least one incidence surface, this incidence surface is positioned at one of this exiting surface side, this fundamental plane is corresponding with this exiting surface, and this fundamental plane and this exiting surface are at a distance of a thickness T; Those microstructure portions are positioned on this fundamental plane, and each microstructure portion also comprises one first base portion and one second base portion, an apex, one first reflecting surface, one second reflecting surface and the planar unit mode at a distance of a width P; Wherein, this first reflecting surface connects this first base portion and this apex, and this first base portion and this apex are at a distance of one first distance L ₁, this second reflecting surface connects this second base portion and this apex, and this second base portion and this apex are at a distance of a second distance L ₂, this planar unit mode is between this second base portion and first base portion, and this second base portion and first base portion are at a distance of an interval S, and it is as follows to satisfy relational expression:

$0.47<\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2}{{2\mathrm{PL}}_1}\right)}^2}}<4.8.$

For achieving the above object, the invention provides a kind of backlight module, it comprises at least one light source and a guiding device, and this light source is in order to throw one first optical path and one second optical path, and this guiding device is in order to receive this first optical path and this second optical path; Wherein, this guiding device comprises a body and a plurality of microstructure portion, this body has refractive index n, and comprise an exiting surface, a fundamental plane and at least one incidence surface, this incidence surface is positioned at a side of this exiting surface, this fundamental plane is corresponding with this exiting surface, and this fundamental plane and this exiting surface are at a distance of a thickness T; These microstructure portions are positioned on this fundamental plane, and each microstructure portion also comprises one first base portion and one second base portion, an apex, one first reflecting surface, one second reflecting surface and the planar unit mode at a distance of a width P; Wherein, this first reflecting surface connects this first base portion and this apex, and this first base portion and this apex are at a distance of one first distance L ₁, this second reflecting surface connects this second base portion and this apex, and this second base portion and this apex are at a distance of a second distance L ₂, this planar unit mode is between this second base portion and first base portion, and this second base portion and first base portion be an interval S apart, and satisfies following formula:

$0.47<\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2}{2{\mathrm{PL}}_1}\right)}^2}}<4.8.$

Thus, this first optical path marches to this planar unit mode total reflection in this body, and this second optical path reflexes to this exiting surface through this a plurality of microstructure portion.

Aforesaid guiding device, wherein, this a plurality of microstructure portion is convex structure or the concavity structure that is positioned on this fundamental plane.

Aforesaid guiding device, wherein, the relational expression of this guiding device also comprises: 4.5＜n*T/S＜46.

Aforesaid guiding device, wherein, first distance L of this microstructure portion ₁With second distance L ₂Length unequal.

Aforesaid guiding device, wherein, the cross section of this first reflecting surface or this second reflecting surface is a straight line, double curve, an elliptic curve or a para-curve.

Thus, the backlight module of the described guiding device of the embodiment of the invention and use thereof can have best optics uniformity coefficient, and its ray homogenization effect is preferable, can not produce light and dark " blanking bar phenomenon ".

Description of drawings

Figure 1A be the embodiment of the invention 1 provide backlight module and its optical path synoptic diagram;

Figure 1B is the optical effect figure of the guiding device of Figure 1A;

Fig. 1 C is the optical effect figure of the guiding device of different structure size;

Fig. 1 D is that the scope of G is positioned at 0.47～4.8 o'clock, at n=1.53, and the parameter combinations synoptic diagram of H/P=0.5;

Fig. 1 E is that the scope of G is positioned at 0.47～4.8 o'clock, at T=2mm, and the parameter combinations synoptic diagram of H/P=0.5;

Fig. 1 F is that the scope of G is positioned at 0.47～4.8 o'clock, at T=2mm, and the parameter combinations synoptic diagram of n=1.53;

Fig. 2 be the embodiment of the invention 2 provide the backlight module synoptic diagram;

Fig. 3 be the embodiment of the invention 3 provide the backlight module synoptic diagram;

Fig. 4 be the embodiment of the invention 4 provide microstructure portion synoptic diagram;

Fig. 5 be the embodiment of the invention 5 provide microstructure portion synoptic diagram;

Fig. 6 be the embodiment of the invention 6 provide the guiding device synoptic diagram;

Fig. 7 be the embodiment of the invention 7 provide the guiding device synoptic diagram.

In the accompanying drawing, the component list of each label representative is as follows:

1,2,3: backlight module, 11,21,31: lampshade, 12,22,32: light source, 13,23,33,43,53,63,73: guiding device, 13A: exiting surface, 13B: incidence surface, 13C, 33C: fundamental plane, 131,631,731: body, 132,232,332,432,632,732: microstructure portion, 1321: the first base portions, 1322: the second base portions, 1323: apex, 1324,4324,5324: the first reflectings surface, 1325,4325,5325: the second reflectings surface, 133,233: planar unit mode;

θ: angle, T: thickness, P: width, H: the degree of depth, S: spacing, L ₁: first distance, L ₂: second distance, I ₁: first optical path, I ₂: second optical path.

Embodiment

For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.

See also Figure 1A, Figure 1A is backlight module and its optical path synoptic diagram that the embodiment of the invention 1 provides.Shown in Figure 1A, a backlight module 1 comprises a light source 12, a lampshade 11 and a guiding device 13.Light source 12 and lampshade 11 all are arranged on the outside, the left side of guiding device 13, and light source 12 is in order to launch light, and lampshade 11 is adjacent with light source 12, in order to the emitted light of reflection source 12, make light be entered the inside of guiding device 13 by the limit, left side of guiding device 13.Guiding device 13 comprises a body 131, a plurality of planar unit mode 133 and a plurality of microstructure portion 132; Body 131 has refractive index n, and comprises an exiting surface 13A, a fundamental plane 13C and an incidence surface 13B; These microstructure portions 132 are the convex structures that are positioned on the fundamental plane 13C, shown in the enlarged drawing of Figure 1A, each microstructure portion 132 comprises one first base portion 1321, one second base portion 1322, an apex 1323, one first reflecting surface 1324 and one second reflecting surface 1325.Wherein, the material of guiding device 13 can be polyethylene terephthalate (Polyethylene Terephthalate, PET), polycarbonate (Polycarbonate, PC), Triafol T (Tri-acetyl Cellulose, TAC), polymethylmethacrylate (Polymethylmethacrylate, PMMA), copolymer of methyl methacrylatestyrene (Methylmethacrylate styrene), polystyrene (Polystyrene, PS) or cyclenes copolymer (Cyclic Olefin Copolymer, COC), perhaps at least two or more described material form.Exiting surface 13A be positioned at guiding device 13 above, incidence surface 13B is positioned at the left side of guiding device 13, fundamental plane 13C be positioned at guiding device 13 below, so incidence surface 13B is in the left side of exiting surface 13A, fundamental plane 13C is corresponding with exiting surface 13A.Fundamental plane 13C and exiting surface 13A are at a distance of a thickness T.These microstructure portions 132 are positioned on the fundamental plane 13C, and the distance of first base portion 1321 and second base portion 1322 is width P.First reflecting surface 1324 connects first base portion 1321 and apex 1323, and first base portion 1321 and apex 1323 are at a distance of one first distance L ₁Second reflecting surface 1325 connects second base portion 1322 and apex 1323, and second base portion 1322 and apex 1323 are at a distance of a second distance L ₂Planar unit mode 133 is between second base portion 1322 and first base portion 1321, and the distance in its cross section is interval S, that is to say, planar unit mode 133 is the horizontal zone between the two adjacent microstructure portions 132.In the present embodiment, the size of each microstructure portion 132, shape are all identical, and the interval S of each planar unit mode 133 also equates.

Shown in Figure 1A, the light that light source 12 is emitted, its conduct comprises the first optical path I ₁And the second optical path I ₂, guiding device 13 receives the first optical path I of light ₁With the second optical path I ₂After, the first optical path I ₁Can march to a plurality of planar unit modes 133 and by total reflection to body 131; The second optical path I ₂Can march to a plurality of microstructure portion 132 and be reflected onto exiting surface 13A.That is to say the first optical path I ₁With the second optical path I ₂After utilizing the reflection of planar unit mode 133 and microstructure portion 132 respectively, penetrate guiding device 13 via exiting surface 13A again.

In a preferred embodiment, light source 12 can be cathode fluorescent tube (Cold cathode fluorescent lamp, CCFL) or light-emitting diode lamp tube (Light emitting diode, LED).In other embodiments, light source 12 and lampshade 11 also can be according to demand respectively about guiding device 13 two outer side edges respectively arrange one.So, the limit, the left and right sides of this guiding device is incidence surface, and the emitted light of two light sources can enter the inside of this guiding device respectively from the limit, the left and right sides of this guiding device.

At this structure, the inventor has carried out the experiment of optical effect at the structure of guiding device 13.See also Figure 1B, Figure 1B is the optics benefit figure of the guiding device of Figure 1A.Wherein, transverse axis is the varying level position with respect to this guiding device 13, and the longitudinal axis then is the relative brightness of these diverse locations, and, this relative brightness=mean flow rate/high-high brightness.As shown in Figure 1B, the relative brightness of guiding device 13 is relevant with arranging of microstructure portion 132, and at microstructure portion 132 places, this relative brightness value presents peak value (peak).If this peak value and mean value difference are excessive, just can cause " blanking bar phenomenon ".

In order to improve " the blanking bar phenomenon " of conventional liquid crystal, promote the quality of its show image, the inventor under the prerequisite of different-thickness T, different refractivity n, different spacing S, has done the experiment of relative brightness at guiding device 13.See also Fig. 1 C, Fig. 1 C is the optical effect figure of the guiding device of different structure size.Shown in Fig. 1 C, no matter the size of thickness T, refractive index n why, along with the interval S of microstructure portion 132 reduces gradually, its relative brightness also improves gradually.That is to say that when the interval S of microstructure portion 132 is more little, represent guiding device 13 more many microstructure portions 132 can be set, namely the density of microstructure portion 132 is more high, then " the blanking bar phenomenon " of its LCD is also more not obvious.Rule of thumb, when this relative brightness reaches more than 0.4, people namely can't tell light and dark striped by naked eyes, also just no longer occur " blanking bar phenomenon ".

Therefore, in order to try to achieve the mathematical relation of relative brightness and thickness T, interval S, refractive index n, the present inventor finds that through repeatedly experiment thickness T, interval S, refractive index n can be combined into a dimensionless parameter U, are used as the characteristic dimension of this guiding device; Wherein:

U＝n*T/S；

At this, the unit of this parameter U is zero dimension.Because parameter U is the function of thickness T, interval S and refractive index n, so by different big or small thickness T, interval S, can record the numerical value of the parameter U of unlike material.Through experiment, find the scope of this dimensionless parameter U between 4.5～46 o'clock, guiding device 13 can have preferable uniformization effect.That is:

4.5＜n*T/S＜46 (1)

In addition, except the structure of guiding device 13, the outward appearance of microstructure portion 132, profile also are the key factors that influences light effect.Therefore, except this dimensionless parameter U, the scope of the depth-to-width ratio of this microstructure portion 132 also can influence light effect; Shown in the enlarged drawing of Figure 1A, this depth-to-width ratio is H/P, and depth H is microstructure portion 132 distance in vertical direction.Rule of thumb, the depth-to-width ratio of microstructure portion 132 should be between 0.05～0.5.That is:

0.05＜H/P＜0.5 (2)

For the size effect of microstructure portion 132 is combined with the effect of interval S, special with above-mentioned formula (1) and formula (2) combination at this, its derivation is as follows:

Formula (1) * formula (2);

→4.5*0.05＜(n*T/S)*(H/P)＜46*0.5；

$\&RightArrow;0.225<\left(\frac{n*T}{S}\right)*\left(\frac{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1*\sin \mathrm{\&theta;}}{P}\right)<23;---\left(3\right)$

Wherein, θ is the angle of first reflecting surface 1324 and fundamental plane 13C.In addition, because P, L ₁, L ₂Be encircled into triangle, so

So

$\&RightArrow;\cos \mathrm{\&theta;}=\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2}{2\mathrm{<figure-callout\; id="1"\; label="P\; L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}{L}_{}{}_1};$

$\&RightArrow;\sin \mathrm{\&theta;}=\sqrt{1-{\mathrm{<figure-callout\; id="2"\; label="cos"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">cos</figure-callout>}}^2\mathrm{\&theta;}}=\sqrt{1-{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2}{2{\mathrm{PL}}_1}\right)}^2};---\left(4\right)$

With formula (4) substitution formula (3):

$\&RightArrow;0.225<\left(\frac{n*T}{S}\right)*\frac{L_1}{P}\sqrt{1-{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1^2-{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2^2}{2{\mathrm{PL}}_1}\right)}^2}<23;---\left(5\right)$

Formula (5) is opened radical sign:

$\&RightArrow;0.47<\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">P</figure-callout>}}^2+{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2}{2P{L}_1}\right)}^2}}<4.8;---\left(6\right)$

Wherein, first distance L of microstructure portion 132 ₁With second distance L ₂Length can be unequal.

By above-mentioned derivation as can be known, if satisfy the relational expression of above-mentioned formula (6), can make backlight module 1 to go out light effect comparatively even, " the blanking bar phenomenon " of guiding device 13 just do not existed.Thus, definition by formula (6), the homogenising scope of the backlight module 1 that can try to achieve guiding device 13 and use, thus make the manufacturers design of the manufacturing go out guiding device 13 and the backlight module 1 of optimization, need not to worry light and dark " blanking bar phenomenon ".

The refractive index n of above-mentioned formula (6), thickness T, interval S, width P, first distance L ₁, second distance L ₂, can then define a homogenising index G:

$G=\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{P^2+{{\mathrm{<figure-callout\; id="1"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_1}^2-{{\mathrm{<figure-callout\; id="2"\; label="L"\; filenames="HSA00000317297900041.png,HSA00000317297900051.png"\; state="\{\{state\}\}">L</figure-callout>}}_2}^2}{2P{L}_1}\right)}^2}};---\left(7\right)$

Therefore, when the scope of homogenising index G was positioned at 0.47～4.8, guiding device 13 just can not produce " blanking bar phenomenon ".

For convenience those skilled in the art know the combination of the various parameters of G clearly, are positioned at 0.47～4.8 o'clock, the relation of its G value and interval S in this scope of also further listing this homogenising index G with graph mode.See also Fig. 1 D, Fig. 1 D is that the scope of G is positioned at 0.47～4.8 o'clock, at n=1.53, and the parameter combinations synoptic diagram of H/P=0.5.Shown in Fig. 1 D, when the thickness T of this guiding device 13 is more big, its homogenising index G is also more high.In addition, under the situation of same thickness T, when this interval S is more little, its homogenising index G also can be more high.Homogenising index G is more high, and namely to represent the effect of homogenising of this guiding device 13 more good, more can not produce " blanking bar phenomenon ".Can be learnt that by Ben Tu when the thickness T of guiding device 13 was 1mm, the G value was approximately 1.1～2.9; When thickness T was 2mm, the G value was approximately 1.5～3.9; When thickness T was 3mm, the G value was approximately 2～4.8.

See also Fig. 1 E, Fig. 1 E is that the scope of G is positioned at 0.47～4.8 o'clock, at T=2mm, and the parameter combinations synoptic diagram of H/P=0.5.Shown in Fig. 1 E, when guiding device 13 used different materials, the homogenising index G difference that its different refractive index n causes was also little.Identical with the trend of Fig. 1 D, when interval S is more little, its homogenising index G also can be more high.Can be learnt by Ben Tu, the guiding device 13 of any material no matter, its G value is approximately 1.5～3.9.

See also Fig. 1 F, Fig. 1 F is that the scope of G is positioned at 0.47～4.8 o'clock, at T=2mm, and the parameter combinations synoptic diagram of n=1.53.Shown in Fig. 1 F, when the depth-to-width ratio of guiding device 13 is more big, the value of H/P is just more big, and its homogenising index G is also more high.Also have, when interval S is more little, its homogenising index G also can be more high.When the depth-to-width ratio H/P of guiding device 13 was 0.05, its G value was approximately 0.5～1.2; When the depth-to-width ratio H/P of guiding device 13 was 0.25, its G value was approximately 1.1～2.8; When the depth-to-width ratio H/P of guiding device 13 was 0.50, its G value was approximately 1.6～4; When the depth-to-width ratio H/P of guiding device 13 was 0.75, its G value was approximately 2～4.8.

Certainly, the present invention also has other embodiment.See also Fig. 2, Fig. 2 is the backlight module synoptic diagram of the embodiment of the invention 2.As shown in Figure 2, backlight module 2 comprises a light source 22, a lampshade 21 and a guiding device 23.Wherein, similar structure repeats no more.The a plurality of microstructure portion 232 of backlight module 2, its cross section is isosceles obtuse triangle identical shaped, same size.Planar unit mode 233 between the two adjacent microstructure portions 232, the interval S in its cross section is also unequal; As shown in Figure 2, its value of the more past the right of the interval S of a plurality of planar unit modes 233 is more little.Because at close light source 22 places, the density of this light (not illustrating) is higher, need come reflection ray by larger area planar unit mode 233, makes light can be passed to the right of guiding device 23; So, the light ray energy of ejaculation guiding device 23 just can be even.

See also Fig. 3, Fig. 3 is the backlight module synoptic diagram of the embodiment of the invention 3.As shown in Figure 3, backlight module 3 comprises a light source 32, a lampshade 31 and a guiding device 33.Wherein, a plurality of microstructure portion 332 of backlight module 3 is the concavity structures that are positioned on the fundamental plane 33C, and these microstructure portions 332 also can be used to reflection ray, make the light (this figure does not illustrate) of guiding device 33 inside be passed to right-hand equably.

See also Fig. 4, Fig. 4 is the microstructure portion synoptic diagram of the embodiment of the invention 4.As shown in Figure 4, first reflecting surface 4324 of guiding device 43 is a plane, and therefore the cross section of first reflecting surface 4324 is a straight line.Second reflecting surface 4325 of guiding device 43 is a curved surface that protrudes slightly downwards, and therefore the cross section of second reflecting surface 4325 can be rendered as hyperbolic curve, elliptic curve or para-curve.Thus, guiding device 43 can make the light of reflection reach better light guide effect by microstructure portion 432 differently contoured first reflecting surface 4324 and second reflecting surface 4325.

See also Fig. 5, Fig. 5 is the microstructure portion synoptic diagram of the embodiment of the invention 5.As shown in Figure 5, first reflecting surface 5324 of guiding device 53 is one slightly to the curved surface that is recessed on, and second reflecting surface 5325 is a curved surface that protrudes slightly downwards.Thus, present embodiment also can reach aforementioned effect.

See also Fig. 6, Fig. 6 is the guiding device synoptic diagram of the embodiment of the invention 6.As shown in Figure 6, comprise a plurality of microstructure portion 632 on this guiding device 63, these microstructure portions 632 are triangle water chestnut mirror column, and are distributed in respectively on the differing heights of body 631.In a preferred embodiment, the mode that just rises and falls with the cycle of these microstructure portions 632 setting that distributes.

See also Fig. 7, Fig. 7 is the guiding device synoptic diagram of the embodiment of the invention 7.As shown in Figure 7, comprise a plurality of microstructure portion 732 on the guiding device 73, these microstructure portions 732 flatly are distributed on the sustained height of body 731, and each microstructure portion 732 all is repeatedly the curved arcuation that prolongs.

In sum, the guiding device of the embodiment of the invention and the backlight module of use thereof can be by the size characteristic zero dimensionizations with this guiding device and this microstructure portion, and try to achieve the luminous efficacy of different size structure.As previously mentioned, no matter be any embodiment, when the scope of the size characteristic coincidence formula (6) of this guiding device and this microstructure portion, this guiding device just has best optics uniformity coefficient, its ray homogenization effect is preferable, can not produce light and dark " blanking bar phenomenon ".

The above only is preferred embodiment of the present invention, and is in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a guiding device is characterized in that, comprises:

One body, this body has refractive index n, and comprises an exiting surface, a fundamental plane and at least one incidence surface, and this incidence surface is positioned at a side of this exiting surface, and this fundamental plane is corresponding with this exiting surface, and this fundamental plane and this exiting surface are at a distance of a thickness T;

A plurality of microstructure portion, these microstructure portions are positioned on this fundamental plane, and each microstructure portion also comprises:

One first base portion and one second base portion at a distance of a width P;

One apex;

One first reflecting surface connects this first base portion and this apex, and this first base portion and this apex are at a distance of one first distance L ₁

One second reflecting surface connects this second base portion and this apex, and this second base portion and this apex are at a distance of a second distance L ₂

One planar unit mode, between second base portion in a microstructure and first base portion of adjacent microstructures, this second base portion and first base portion are at a distance of an interval S, and it is as follows to satisfy relational expression:

$0.47<\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{P^2+{L_1}^2-{L_2}^2}{2{\mathrm{PL}}_1}\right)}^2}}<4.8.$

2. guiding device according to claim 1 is characterized in that, this a plurality of microstructure portion is convex structure or the concavity structure that is positioned on this fundamental plane.

3. guiding device according to claim 1 is characterized in that, the relational expression of this guiding device also comprises: 4.5＜n*T/S＜46.

4. guiding device according to claim 1 is characterized in that, first distance L of this microstructure portion ₁With second distance L ₂Length unequal.

5. guiding device according to claim 1 is characterized in that, the cross section of this first reflecting surface or this second reflecting surface is a straight line, double curve, an elliptic curve or a para-curve.

6. a backlight module is characterized in that, comprises:

At least one light source is in order to throw one first optical path and one second optical path;

One guiding device, in order to receive this first optical path and this second optical path, this guiding device also comprises:

One body, this body has refractive index n, and comprises an exiting surface, a fundamental plane and at least one incidence surface, and this incidence surface is positioned at a side of this exiting surface, and this fundamental plane is corresponding with this exiting surface, and this fundamental plane and this exiting surface are at a distance of a thickness T;

A plurality of microstructure portion, these microstructure portions are positioned on this fundamental plane, and each microstructure portion also comprises:

One first base portion and one second base portion at a distance of a width P;

One apex;

One first reflecting surface connects this first base portion and this apex, and this first base portion and this apex are at a distance of one first distance L ₁

One second reflecting surface connects this second base portion and this apex, and this second base portion and this apex are at a distance of a second distance L ₂

One planar unit mode, between second base portion in a microstructure and first base portion of adjacent microstructures, this second base portion and first base portion are at a distance of an interval S;

Wherein, this first optical path marches to this planar unit mode total reflection in this body, and this second optical path reflexes to this exiting surface through this a plurality of microstructure portion, and satisfies following equation:

$0.47<\sqrt{\frac{n*T*L_1}{S*P}*\sqrt{1-{\left(\frac{P^2+{L_1}^2-{L_2}^2}{2{\mathrm{PL}}_1}\right)}^2}}<4.8.$

7. backlight module according to claim 6 is characterized in that, first distance L of this microstructure portion ₁With second distance L ₂Length unequal.

8. backlight module according to claim 6 is characterized in that, the cross section of this first reflecting surface or this second reflecting surface is a straight line, double curve, an elliptic curve or a para-curve.

Images