CN101738670A - Light guide plate with light guiding structures - Google Patents

Abstract

The invention relates to a light guide plate with light guiding structures, which is characterized in that: the light guide plate is provided with a plurality of light guiding structures arranged on a bottom surface; each light guiding structure sequentially comprises a first photic surface, a first traveling surface, a second photic surface and a second traveling surface along a first direction; and the first photic surface meets the condition that: a squared value of the projection width along the first direction is less than or equal to a product of the sum of projection widths of the first traveling surface and the second traveling surface along the first direction with [(2 pi)-1], and n*sin(pi/2-an included angle of a direction vector of the first photic surface and the bottom surface) is more than or equal to 1, wherein n is a material refractive index of the light guide plate; therefore, when contacting the first photic surface of any one light guiding structure, light is emitted uniformly to the outside from an emergent surface of the light guide plate through total reflection and geometric diffusion.

Description

Light guide plate with light guide structure

[technical field]

The present invention relates to a kind of light guide plate, particularly relate to a kind of light guide plate with light guide structure.

[background technology]

The function of light guide plate is the light that will be entered by side direction in the light guide plate, after the microtexture reflection via the light guide plate lower surface, via being positioned at the outer optics supplementary plate of light guide plate, for example after the even light of diffusion sheet, prismatic lens, the light harvesting effect, convert high brightness and briliancy uniform surface light source again to; And the characteristic of light guide plate mainly is to depend on that the microstructure that is arranged at this bottom surface of light guide plate comes the directing light direction, with the briliancy that improves panel and the homogeneity of control brightness.

Consult Fig. 1, be illustrated in figure 1 as a light guide plate with V-groove structure, it is the line style light that a luminescence unit 100 that is arranged at this light guide plate one side is sent along a first direction X, and guiding turns to the back to penetrate perpendicular to the second direction Y of this first direction X with essence and is dissipated to the external world.

This luminescence unit 100 comprises an arc reflex housing 101, and a linear light sorurce 102 that is arranged in this reflex housing 101, and the opening of this arc reflex housing 101 abuts against and is connected in this light guide plate, and allows light enter in this light guide plate.

This light guide plate has one perpendicular to first direction X, and along the plane of incidence 21 of this first direction X setting spaced apart, a reflecting surface 22, along second direction Y setting spaced apart and connect this plane of incidence 21 and the top of reflecting surface 22 and an exiting surface 23 and a bottom surface 24 of bottom respectively, and most extend and the cross section becomes the sensitive surface 25 of inverted V-shape to these exiting surface 23 directions from this bottom surface 24 respectively, this each sensitive surface 25 defines a V-groove 26.After linear light entered this light guide plate via this plane of incidence 21, the light that touches this sensitive surface 25 can be via refraction, reflection and/or spuious penetrating by exiting surface 23 bright dippings.

But, because when incident light source touches described sensitive surface 25, because of described V-groove structure 26 can be destroyed the total reflection condition that light is produced in light guide plate is advanced, make the light can be in light guide plate via repeatedly refraction and/or reflection, cause the consume of energy, thereby can't effectively increase brightness, and the lack of uniformity of exiting surface 23, so reflector plate of need arranging in pairs or groups again, diffusion sheet, assisting of various optical sheets such as light harvesting blast sheet, just can reach the effect of leaded light and even bright dipping, thereby can cause complicated integral structure and materials used various, therefore the light guide effect that how to improve light guide plate is one of important topic of researching and developing at present the required solution of light guide plate to promote the briliancy and the uniformity coefficient of panel.

[summary of the invention]

The people's bodyguard that has general knowledge in this technical field is all known, the design of light guide board microstructure is that the light of will advance along first direction is through superrefraction, reflection, scattering, and/or guiding essence is advanced along second direction after the diffusion, therefore, how to control through superrefraction, reflection, scattering, and/or essence then is the main emphasis of light guide board microstructure design along the advance uniformity coefficient of light of this second direction after the diffusion.

The inventor finds, when light is advanced when touching a reflecting surface of microstructure along this first direction, because the angle of light contact and the difference of position, therefore after refraction and/or reflection, can produce towards the light of advancing from all directions, and be that the light going direction that obtains a good control distributes, the reflecting surface of dull and stereotyped aspect is optimal selection, consult Fig. 2, and when the side direction incident light along this first direction incident turns to this second direction to advance through a sloping reflecter structure, because inverse square law (inverse-square law), light has how much diffusion phenomenons, and whereby, the light of advancing along this second direction has the effect of even diffusion.

Consult Fig. 3, Fig. 4, pass through Gaussian beam (Gaussian beam) derivation formula again and learn:

$\mathrm{Rayleigh\; length}\left(b\right)=\frac{{{2\mathrm{\πW}}_0}^2}{\mathrm{\λ}}$

$\mathrm{beamwidth}:W\left(z\right)=\mathrm{Wo}\sqrt{[1+{\left(\frac{\mathrm{\λZ}}{{{\mathrm{\πW}}_0}^2}\right)}^2]}\≈\frac{\mathrm{\λz}}{{\mathrm{\πW}}_0}$

$\mathrm{farfield\; angle\θ}\→2W\left(z\right)/\mathrm{z\θ}=\frac{2\mathrm{\λ}}{{\mathrm{\πW}}_0}=0.637\mathrm{\λ}/W_0$

Ralyeigh length: be that Gaussian beam is not dispersed, the distance of keeping parallelism light.

W ₀: be the waistband that Gauss light is stated.

θ: be the Gaussian beam dispersion angle.

Because on practice, the integral width of light guide plate (W) is more than 40 times of thickness (z) normally, and lambda1-wavelength λ is about 0.5 μ m, λ ≈ 0.5

$\→W\left(z\right)\≥40z=\frac{\mathrm{\λz}}{{\mathrm{\πW}}_0}=\frac{0.5z}{\mathrm{\π}{W}_0}$

$\→W_0\≤\frac{0.5}{\mathrm{\π}}\left(\frac{L_1+L_2}{W_0}\right)\mathrm{\μm}$

Via above-mentioned wave optics calculating and experiment learn that can produce the reflected light of Gaussian beam (Gaussian beam) in this reflecting surface, the corner crest line place of this reflecting surface then can produce angle scattered light (edgediffraction).W when this reflecting surface ₀(reflecting surface is along the first direction projection) is big more, then Gaussian beam (Gaussian beam) is just big more to the parallel optically focused physical influence that general performance produced, relatively, the influence that produced of the angle scattered light (edge diffraction) that produces of corner crest line is just more little; Angle scattered light (edge diffraction) is with the performance of the form of column ripple, and can overlap the zone in the exiting surface place, so to the auxiliaring effect that is evenly distributed with of light; And according to this during the microstructure of limit design light guide plate, then can be different from the mechanism (mainly be refraction, reflection, and/or spuious) of the microstructure of existing light guide plate, and change direct of travel and evenly bright dipping with how much diffusion phenomenons with the total reflection of light.

Therefore, the objective of the invention is in the light guide plate that a kind of light guide structure with wave optics condition design is provided.

Light guide plate with light guide structure of the present invention, comprise a plane of incidence, and be connected this plane of incidence is connected this plane of incidence and reflecting surface root edge with the exiting surface, of reflecting surface apical margin bottom surface with this plane of incidence reflecting surface, at interval along a first direction, and most light guide structure that is arranged at this bottom surface.Each light guide structure comprises one first sensitive surface, one first running face, one second sensitive surface in regular turn along this first direction, and one second running face, and this first sensitive surface along the square value of the projection width of this first direction be not more than this first and second running face along this first direction projection width and with (2 π) ^-1Product, n * sin (angle of the direction vector of pi/2-this first sensitive surface and this bottom surface) 〉=1, wherein, n is the refractive index of the constituent material of this light guide plate.When linear light sources enters when advancing in this light guide plate from this plane of incidence to the light of this first direction emission, light touches this first sensitive surface and produces total reflection and turn to this second direction evenly to be penetrated by exiting surface with how much diffusion phenomenons.

Effect of the present invention is by the design of the most light guide structures that meet the wave optics condition, with the light that enters in the light guide plate, turn to this second direction evenly to penetrate light via producing most total reflections and diffusion phenomenon behind described first sensitive surface of contact by exiting surface, and the light of reflection or diffusion can be stabilized when continuing to advance by this first running face and second running face forward, horizontal infection then returns back to after the original light field mode and contacts with another first sensitive surface, so makes that the light that penetrates from exiting surface is more even, brightness is higher.

[description of drawings]

Fig. 1 is a front elevational schematic, and existing V-groove structure light guide plate is described;

Fig. 2 is how much diffusion phenomenons of light synoptic diagram;

Fig. 3 is a Gaussian beam synoptic diagram;

Fig. 4 is a synoptic diagram, and the derive relativeness of formula of reflection surface of contact and a Gauss is described;

Fig. 5 is a synoptic diagram, illustrates that the present invention has first preferred embodiment of the light guide plate of light guide structure; And

Fig. 6 is a synoptic diagram, illustrates that the present invention has second preferred embodiment of the light guide plate of light guide structure.

[embodiment]

The present invention is described in detail below in conjunction with drawings and Examples:

Before the present invention is described in detail, be noted that in the following description similar elements is to represent with identical numbering.

Consult Fig. 5, the present invention has one first preferred embodiment of the light guide plate of light guide structure, be the line style light that a luminescence unit 100 that is arranged at this light guide plate one side is sent along first direction X, guiding turns to the back to penetrate perpendicular to the second direction Y one-tenth face type light of this first direction X with essence and is dissipated to the external world.

This luminescence unit 100 comprises an arc reflex housing 101, and a linear light sorurce 102 that is arranged in this reflex housing 101, and the opening of this arc reflex housing 101 abuts against and is connected in this light guide plate, and allows light enter in this light guide plate.

This light guide plate 3 comprise the plane of incidence 31 perpendicular to this first direction X, one along this first direction X and with separately reflecting surface 32 of this plane of incidence 31, spaced apart and be connected this plane of incidence 31 and the apical margin of reflecting surface 32 and an exiting surface 33 and a bottom surface 34 of root edge respectively along this second direction Y, and several are arranged at the light guide structure 35 of this bottom surface 34, and this plane of incidence 31 matches to abut against with the opening part of this arc reflex housing 101 and is connected.

This light guide plate 3 is to be selected from by high light-transmitting materials, formation such as PMMA, PC for example, do not limit to its kind, constituent material composition in the present embodiment, send and directly enter in this light guide plate 3 by this linear light sorurce 102 and propagate from this plane of incidence 31 to light that first direction X advances, and after light that other directions are advanced is by these arc reflex housing 101 reflections also essence directly enter in this light guide plate 3 towards this first direction X from this plane of incidence 31.

Described light guide structure 35 is arranged at intervals perpendicular to this first direction X and is arranged at this bottom surface 34, each light guide structure 35 comprise one from an edge of this bottom surface 34 to first direction X and towards first sensitive surface 351 of the oblique extension of second direction Y, one is parallel to first running face 353 that this second direction Y extends from first sensitive surface, 351 edges, one from these first running face, 353 edges to this first direction X and towards second sensitive surface 352 that is in reverse to the oblique extension of this second direction Y, and one be parallel to second running face 354 that this first direction X extends from these second sensitive surface, 352 edges.

This first sensitive surface 351 is θ with the direction vector angle of this bottom surface 34 ₁, and be W along the vector projection of this first direction X ₁, this first running face 353 is W along the width of this first direction X ₃, this bottom surface 34 is H to the distance of this exiting surface 33 ₁, this first running face 353 to the distance of this exiting surface 33 is H ₂

This first sensitive surface 351 and this bottom surface 34 to vector angle θ ₁Meet

$n_1\mathrm{Sin}(\frac{\mathrm{\π}}{2}-{\mathrm{\θ}}_1)\≥1$ n ₁Refractive index for the light guide plate material

Therefore can make the light of advancing when touching first sensitive surface 351 of described angle design, can essence vertically turn to this second direction Y to advance, work as angle theta via total reflection along this first direction X ₁Angle during less than 30 °, the parallel optically focused physical influence that light is represented after reflecting is just big more, how much diffuse effect can be much larger than the angle scattered light, and works as angle theta ₁Angle during greater than 70 ° then the parasitic light through the angle scattering can increase, therefore can cause this to produce total reflection and/or diffusion phenomenon along the light that first direction X advances, and essence vertically changes comparatively not enough towards resulting type light of this second direction Y uniformity coefficient, therefore, preferably, the direction vector angle theta of this first sensitive surface 351 and this bottom surface 34 ₁It is 30 °～70 °.

When the angle theta of this first sensitive surface 351 with the direction vector of this bottom surface 34 ₁When being 30 °～70 °, learn that via above-mentioned Gaussian beam derivation formula calculating this first sensitive surface 351 is along the vector projection W of this first direction X ₁Be 3～500 μ m, this first running face 353 is along the width W of first direction X ₃Be 5～500 μ m, and W ₁With W ₃Ratio be 1～100 times.

Enter the light of this light guide plate 3 along this first direction X from this plane of incidence 31, touch this wherein during this first sensitive surface 351 of a light guide structure 35, can produce total reflection and/or diffusion phenomenon, essence is vertically changeed towards this second direction Y from these exiting surface 33 ejaculations, other light that do not touch this first sensitive surface 351 then continue to propagate to first direction X, and in the narrowed areas that enters 33 of this first running face 353 and exiting surfaces, because this first running face 353 is along the width W of this first direction X ₃Much larger than the vector projection width W of this first sensitive surface 351 along this first direction X ₁(being 1～100 times in this example), so light can be replied stable to the horizontal infection state, when advancing to this second sensitive surface 352 afterwards, again via behind expanding mechanism and the answer zone through 33 of this second running face 354 and exiting surfaces, after allowing light be returned to original light field mode, continue to advance to this first direction X, and when touching next light guide structure 35, repeat said process, be dissipated to the external world and photoconduction can be drawn to penetrate with the aspect of face type light towards this second direction Y.

In addition, when this light guide structure 35 was applied to the light guide plate 3 of different-thickness, this light guide structure 35 of adjustable design was by controlling this first sensitive surface 351 along this first direction X W of projection width ₁, make the distance H of this exiting surface 33 to this bottom surface 34 ₁Much larger than the vector projection width W of this first sensitive surface 351 along this first direction X ₁Square value multiply by 2 π λ ^-1(λ is the incident light wavelength), and can promote the light guide effect of the light guide plate 3 of different-thickness, and increase the uniformity coefficient of exiting surface 313.

That is to say, when this exiting surface 33 and these bottom surface 34 distance H ₁Then can be when big by increasing W ₁Make the light that turns to this second direction Y fully reach how much diffusional effects and obtain one, when this exiting surface 33 and these bottom surface 34 distance H uniformly towards light ₁Hour, can be by reducing W ₁Increase the diffuse effect of light, and make the light that turns to this second direction Y become one more uniformly towards light in this light guide plate 3.

What deserves to be mentioned is, when the length of light guide plate more then can be by the distance W of adjusting this second running face 354 ₄And utilize majority and spacing along this first direction X light guide structure 35 decrescence, increase light along the number that this first direction X turns to this second direction Y to advance along exiting surface 33 via a total reflection, make the briliancy of exiting surface 33 increase, obtain the face type light that briliancy is higher and uniformity coefficient is better.

Therefore, preferably, the distance W of this second running face 354 ₄Be 5～500 μ m, W ₄With W ₂Ratio be 1～100.

Consult Fig. 6, the present invention has one second preferred embodiment of the light guide plate of light guide structure, be the line style light that a luminescence unit 100 that is arranged at these light guide plate 3 one sides is sent along first direction X, guiding turns to the back to penetrate perpendicular to the second direction Y one-tenth face type light of this first direction X with essence and is dissipated to the external world.

This luminescence unit 100 comprises an arc reflex housing 101, and a linear light sorurce 102 that is arranged in this reflex housing 101, and the opening of this arc reflex housing 101 abuts against and is connected in this light guide plate 3, and allows light enter in this light guide plate 3.

This light guide plate 3 comprise the plane of incidence 31 perpendicular to this first direction X, one along this first direction X and with separately reflecting surface 32 of this plane of incidence 31, spaced apart and be connected apical margin and an exiting surface 33 of root edge and the light guide structure 35 that a bottom surface 34, majority are arranged at this bottom surface 34 of this plane of incidence 31 and reflecting surface 32 respectively along this second direction Y, and a catoptron 36 that is arranged at this reflecting surface 32, and this plane of incidence 31 matches to abut against with the opening part of this arc reflex housing 101 and is connected.

This catoptron 36 can be selected from the material with high index of refraction, for example golden, aluminium, silver, titanium nitride, zirconia etc., at least repeat the formation of piling up once, be reflected and be in reverse to this first direction X when will contact this catoptron 36 and advance along the light that this first direction X advances, and behind this second sensitive surface 352 of this each light guide structure 35 of contact, carry out total reflection and/or diffusion phenomenon and the spread state identical with this first sensitive surface 351, be dissipated to the external world and photoconduction drawn to penetrate with the aspect of face type light towards this second direction Y, via this first, two sensitive surfaces 351,352 lead simultaneously, and this exiting surface 33 sends then more can increase uniformity coefficient towards light because of producing a smooth overlapping region to each other towards light.

This second sensitive surface 352 is θ with the direction vector angle of this bottom surface 34 ₂, and θ ₂For satisfying n * sin (pi/2-θ ₂) 〉=1, wherein, n is the refractive index of the constituent material of this light guide plate 3, can while and this θ ₁Match and put forward the outgoing light homogeneity of this light guide structure 35.Therefore, preferably, the direction vector angle theta of this second sensitive surface 352 and this bottom surface 34 ₂It is 30 °～70 °.

When the light of advancing along this first direction X touches this catoptron 36, can be reflected and be in reverse to this first direction X and advance, when touching this second sensitive surface 352, can see through total reflection or diffusion phenomenon once more, turn to this second direction Y to penetrate from this exiting surface 33, other light that do not touch this second sensitive surface 352 then continue towards being in reverse to this first direction X propagation of advancing, by with the identical total reflection of light of advancing along this first direction X, diffusion and communication mode, increase once more turns to the light of this second direction Y, so recycle energy, less wastage, the efficient height, and can further promote this exiting surface 33 towards luminance brightness and uniformity coefficient.

Conclude above-mentioned, the present invention has the light guide plate of micrometer structure then by light guide structure 35 designs that meet the wave optics condition, to turn to this second direction Y by the light that this plane of incidence 31 enters by a most total reflection and diffusion phenomenon along this first direction X effectively, become by this exiting surface 33 evenly make progress towards light, can relend light after by the effect of catoptron 36 this second sensitive surface 352 will being reflected in addition again via total reflection, diffusion turns to exiting surface 33 bright dippings, and can further increase the brightness and the homogeneity of exiting surface 33, can improve existing V-groove structure light guide plate owing to can destroy the total reflection condition that light produces in light guide plate, the refraction that produces repeatedly reaches/reflects and the energy of consume light, cause brightness can't effectively increase and cause the shortcoming of the brightness uniformity deficiency of exiting surface, so can reach purpose of the present invention really.

Claims (7)

1. light guide plate with light guide structure, comprise a plane of incidence, one along a first direction and this plane of incidence reflecting surface at interval, an exiting surface that connects this plane of incidence and reflecting surface apical margin, and bottom surface that connects this plane of incidence and reflecting surface root edge, it is characterized in that: this light guide plate with light guide structure also comprises the light guide structure that several are arranged at this bottom surface, this each light guide structure comprises one first sensitive surface in regular turn along this first direction, one first running face, one second sensitive surface, and one second running face, and this first sensitive surface along the square value of the projection width of this first direction be not more than this first, two running faces along this first direction projection width and with (2 π) ^-1Product, n * sin (angle of the direction vector of pi/2-this first sensitive surface and this bottom surface) 〉=1, wherein, n is the refractive index of the constituent material of this light guide plate, when the light of linear light sources emission enters when advancing in this light guide plate from this plane of incidence, light essence is advanced towards this first direction, and produces total reflection and how much diffusion phenomenons when contacting this first sensitive surface of arbitrary light guide structure, advances and evenly penetrates to extraneous from this exiting surface and turn to this exiting surface direction.

2. the light guide plate with light guide structure as claimed in claim 1 is characterized in that: this first running face is along the projection width of width much larger than this first sensitive surface along this first direction of this first direction.

3. the light guide plate with light guide structure as claimed in claim 2 is characterized in that: this second sensitive surface also must satisfy n * sin (angle of the direction vector of pi/2-this second sensitive surface and this bottom surface) 〉=1.

4. the light guide plate with light guide structure as claimed in claim 3 is characterized in that: the angle of the direction vector of this first sensitive surface and this bottom surface is 30 °～70 °.

5. the light guide plate with light guide structure as claimed in claim 4 is characterized in that: the angle of the direction vector of this second sensitive surface and this bottom surface is 30 °～70 °.

6. the light guide plate with light guide structure as claimed in claim 4 is characterized in that: the angle of the direction vector of this first sensitive surface and this bottom surface equals this second sensitive surface and this first running face direction vector angle along exiting surface.

7. the light guide plate with light guide structure as claimed in claim 3 is characterized in that: this light guide plate also comprises a catoptron that is arranged at this reflecting surface, will contact the light reflection of this reflecting surface and advance towards the direction that is in reverse to this first direction.

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