CN100562686C - Planar light source device - Google Patents

Abstract

The invention provides planar light source device.In the present invention, the light entrance face (23) with LGP (22) disposes light source (21) opposed to each other.The light that penetrates from light source (21) guides in LGP (22).Being formed with the deflection pattern (25) of recessed pattern-like at the lower surface of LGP (22), is to be provided with directive property transformation component (30) between photo-emission part (25a) and par (28) on the inclined plane towards the light source side of deflection pattern (25).Directive property transformation component (30) plays the effect of the directive property that improves the light that incides photo-emission part (25a), improves thus from the directive property of the light of light-emitting face (24) ejaculation.As directive property transformation component (30), be for example will be than wide-angle tilt ground by the light of vertical line to penetrate of photo-emission part (25a) reflection back with respect to light emergence face (24) to photo-emission part (25a) reflection.

Description

Planar light source device

Technical field

The present invention relates to planar light source device.Be particularly related to the planar light source device of backlight and preceding irradiation that the such image display panel of liquid crystal panel is thrown light on etc.

Background technology

As the backlight and preceding irradiation that liquid crystal panel is thrown light on, adopt the planar light source device that constitutes by light source and LGP.In this planar light source device, require to have following characteristic: (1) can be penetrated the light of light source to liquid crystal panel from LGP efficiently, and (2) are the evenly ejaculation of planar expansion ground with the light of light source by LGP.

As planar light source device with above-mentioned characteristic, have LGP with opposed of light-emitting face on the planar light source device (for example, patent documentation 1 to 3) of relief pattern is set and the planar light source device (for example, patent documentation 4) of prism-shaped pattern is set.These planar light source devices are represented by Fig. 1, Figure 10 and Figure 11.Fig. 1 is illustrated in the opposed light source 11 that disposes in side (light entrance face 13) with LGP 12, LGP 12 with 14 opposed of light-emitting faces on to form the cross section be leg-of-mutton recessed pattern 15.Figure 10 represent to form LGP 12 by prismatic pattern 16 with 14 opposed of light-emitting faces.Figure 11 represents, LGP 12 with 14 opposed of light-emitting faces on to form the cross section be leg-of-mutton convex pattern 17.

At first, the situation to the planar light source device of Fig. 1 describes.Light from light source 11 penetrates enters in the LGP 12 from light entrance face 13, total reflection and guiding LGP 12 between the upper surface (light-emitting face 14) of LGP 12 and lower surface.And then a plurality of cross sections of inciding in that the lower surface of LGP 12 forms are the photo-emission part 15a of leg-of-mutton recessed pattern 15.Reflected by photo-emission part 15a if incide the light of recessed pattern 15, then this reverberation just penetrates from light-emitting face 14, to penetrating with the opposed liquid crystal panel of the upper surface of LGP 12.

And, as shown in Figure 2, penetrating to the outside even incide the light transmission photo-emission part 15a of recessed pattern 15, the light that incides the 15b of the plane of incidence again of recessed pattern 15 also can return in LGP 12 and utilizes from plane of incidence 15b again.Its result has improved the utilization ratio of light.

In the planar light source device of Fig. 3 to Fig. 5 presentation graphs 1, perpendicular to the distribution of the luminosity in the face of LGP 12.Fig. 3 is the figure that the relation of the luminosity of the light in the LGP 12 and leaded light angle φ 1 is incided in expression.As shown in Figure 6, this leaded light angle φ 1 is the angle that records from the horizontal line perpendicular to light entrance face 13, will be made as positive angle towards the direction of the lower surface of LGP 12, will be made as negative angle towards the direction of upper surface.Fig. 4 is the figure that the relation of the luminosity of the light in the recessed pattern 15 and incident angle φ 2 is incided in expression.As shown in Figure 6, this incident angle φ 2 is angles that the horizontal line from the lower surface that is parallel to LGP 12 records, and will be made as positive angle towards the direction of the lower surface of LGP 12, will be made as negative angle towards the direction of upper surface.The figure of the luminosity of Fig. 5 light that to be expression penetrate from light-emitting face 14 and the relation of shooting angle φ 3.As shown in Figure 6, this shooting angle φ 3 is the angles that record from the normal perpendicular to light-emitting face 14, and the direction of leaving light source 11 is made as positive angle, and the direction of convergence light source 11 is made as negative angle.

Because the light that penetrates in light source 11 is coniform radiation, so as shown in Figure 1, the light that incides in the LGP 12 has radial expansion at the thickness direction of LGP 12.For example, if the refractive index of hypothesis LGP 12 is 1.5, then the light of propagating in LGP 12 has the expansion of maximum ± 41 degree at its thickness direction.Therefore, in photometric distribution shown in Figure 3, luminosity is expanded in the scope of φ 1=-41 degree～+ 41 degree, and is expressed as symmetrical distribution.

Because the photo-emission part 15a of recessed pattern 15 tilts with respect to the lower surface of LGP 12, so the light (φ 2 is negative light) from the below also incides recessed pattern 15, but compare with the light that incides recessed pattern 15 from the top, light is difficult from recessed pattern 15 incidents of direction down.Therefore, shown in the photometric distribution of Fig. 4, the luminosity that incides the light of recessed pattern 15 is expanded in the scope of φ 2=-41 degree～+ 41 degree, but its peak value is shifted to positive angle direction.

The light that incides photo-emission part penetrates towards light-emitting face 14 reflections and from light-emitting face 14.By adjusting the inclination angle of photo-emission part 15a, can penetrate light to any direction, but the light that incides photo-emission part 15a expands as the photometric distribution of Fig. 4, the light that is reflected by photo-emission part 15a also has expansion.Therefore, shown in the photometric distribution of Fig. 5, the expansion of the light that penetrates from light-emitting face 14 is because big when light-emitting face 14 refractions are compared in LGP 12 inside.

As the liquid crystal indicator of the display of portable phone or mobile device, PC etc. usually from top view.Therefore, require liquid crystal indicator to improve front face brightness, on the other hand, as shown in Figure 7, become the light that penetrates than wide-angle tilt to become the useless light of the eyes that can not arrive the observer with frontal with respect to liquid crystal panel 19.About planar light source device, inject to the useless light that the interior light in zone that is decorated with oblique line among Fig. 5 becomes the eyes that can not arrive the observer.The expansion of the light that penetrates from the light-emitting face 14 of LGP 12 is bigger like this, and the light quantity of useless light has following problem more for a long time: not only make the utilization ratio step-down of the light of planar light source device, and the loss of light is more and hinder front face brightness is improved.

In addition, as planar light source device, as shown in Figure 8, the light source of the light source that adopts point-like is arranged as light source 11.In this planar light source device, the expansion of the light that penetrates from light-emitting face 14 becomes as the zone that has applied pears skin shape decorative pattern among Fig. 8, expand change greatly in perpendicular to the plane of LGP 12 by light source 11, narrows down on the direction perpendicular to this plane.In such planar light source device, shown in the photometric distribution as shown in Figure 5, when tilted direction penetrated, only the zone of certain direction was (for example owing to watch the angle of LGP 12 with bigger shooting angle for light, be decorated with the zone of oblique line among Fig. 8) brighten, produce bright line on the surface of LGP 12.Because such bright line makes the lightness inequality of the picture of the liquid crystal indicator when tilted direction is watched, so produce the problem of aesthetics variation of the picture of liquid crystal indicator.

The planar light source device that is provided with Figure 10 of the jagged prismatic pattern 16 in cross section has the problem same with the planar light source device of Fig. 1, so omit its explanation.

Below, the planar light source device of Figure 11 is described.This is the planar light source device that is formed with convex pattern 17 at the lower surface of LGP 12.In the planar light source device of Fig. 1, such with bigger shooting angle φ 3 from the light light 31 as shown in phantom in Figure 9 that light-emitting face 14 penetrates, be the light (φ 2 is negative light) that incides the photo-emission part 15a of recessed pattern 15 from the below.To this, in the planar light source device of Figure 11, hindered by the par 18 of the lower surface of LGP 12, do not incide the photo-emission part 17a of convex pattern 17 from the light of below, only the light from the top incides photo-emission part 17a.Therefore, reduce to the light that tilted direction penetrates with bigger shooting angle from light-emitting face 14, the directive property of the light that penetrates from light-emitting face 14 uprises.

But as shown in figure 11, in this planar light source device, the light that sees through the photo-emission part 17a of convex pattern 17 no longer incides LGP 12 and penetrates to the outside from lower surface.Especially, only the light from the top incides photo-emission part 17a, if this light is penetrated with photo-emission part 17a reflection and from the direction of light-emitting face 14 to approximate vertical, then needs by the direct of travel significantly deflection of reflection with light.For this reason, need to determine the inclination angle of photo-emission part 17a, so that the incidence angle of the light that incides photo-emission part 17a is diminished, its result, the major part that incides the light of photo-emission part 17a sees through photo-emission part 17a and disperses.

Thereby in the planar light source device of Figure 11, the light loss that light caused that sees through convex pattern 17 becomes big, and the light utilization efficiency of planar light source device is reduced.And then because this light loss, the brightness of the picture of liquid crystal indicator reduces.

In addition, in the planar light source device of Figure 11, since only be down towards light incide the photo-emission part 17a of convex pattern 17, so inciding the angle of the light of photo-emission part 17a is defined, existence can not make sufficient light quantity incide photo-emission part 17a, the problem that the light quantity that penetrates from light-emitting face 14 also tails off.

In addition, be used as under the situation of preceding irradiation at the planar light source device with Figure 11, the light that loses from convex pattern 17 leakages directly penetrates to the observer.This situation as shown in figure 12.Because this leak light is overlapping with the image light by liquid crystal panel 19, institute makes the aesthetics variation of image so that the picture contrast reduction of liquid crystal indicator.

As mentioned above, in the planar light source device of Figure 11, have following problem: (1) light becomes big from the leakage of convex pattern, the utilization rate step-down of light, and the lightness of picture reduces, and as under the situation of preceding irradiation, picture contrast reduces (2).Therefore, be desirably in the planar light source device that has as Fig. 1 or pattern shown in Figure 10, improve the utilization ratio of light, improve its front face brightness.

Patent documentation 1: TOHKEMY 2002-14341 communique

Patent documentation 2: TOHKEMY 2000-314882 communique

Patent documentation 3: TOHKEMY 2001-343532 communique

Patent documentation 4: TOHKEMY 2003-215578 communique

Summary of the invention

The present invention carries out in view of above-mentioned technical task, and its purpose is, is formed with on LGP in the planar light source device of pattern of recessed pattern or prismatic pattern, improves the directive property of the light that penetrates from LGP.

First planar light source device of the present invention has to be made from the light propagation of light entrance face incident and the LGP that penetrates from light-emitting face, light source with the light entrance face side that is configured in LGP, it is characterized in that, having of described LGP: the par of reflecting and guide the light in the described LGP with the opposed mask of light-emitting face, the photo-emission part that reflects with light and penetrate from light-emitting face to guiding, at least a portion of described photo-emission part is positioned at than the extended line of described par more near the inboard of LGP, described flat part in than described photo-emission part more near the position of light source side, and, the directive property transformation component that has the directive property that can improve the light that incides described photo-emission part in the light source side of described photo-emission part, when watching perpendicular to the direction of the light-emitting face of described LGP, the width of described directive property transformation component is smaller or equal to 4 times of the width of described photo-emission part, described directive property transformation component is formed by first inclined plane, and first inclined plane is more outstanding laterally than described par.

In the present invention, so-called directive property is meant, the photometric distribution of light is more than or equal to the width of the angle in its zone of peaked 1/2, and perhaps luminosity is the width more than or equal to the angle in its zone of peaked 1/10, is that directive property improves during the narrowed width of this directive property.And so-called photo-emission part is, has the zone of the function that the light that will guide in LGP penetrates to the light-emitting face reflection and from light-emitting face.And so-called par is, has light reflection and guiding from light entrance face incident, makes light in the LGP be the zone of the function of planar expansion.And the par not necessarily is parallel to light-emitting face, can also tilt with respect to light-emitting face.At this moment, make not total reflection of light owing to the par sometimes but some sees through, as long as but satisfy above-mentioned condition and just can be considered as the par.

As first planar light source device of the present invention, because the light source side at photo-emission part has the directive property transformation component, the zone that promptly has the effect of the directive property that improves the light that incides photo-emission part, so incide the directive property of the light of photo-emission part by raising, can improve the directive property of the light that penetrates by the photo-emission part reflection and from light outgoing portion.Thus,, then can reduce from LGP, the picture of image display device is brightened to the light that useless direction penetrates if this planar light source device is used in the backlight or preceding irradiation etc. of image display device.

Second planar light source device of the present invention has the LGP that will propagate from the light of light entrance face incident and penetrate from light-emitting face, light source with the light entrance face side that is configured in LGP, it is characterized in that, having of described LGP: the par of reflecting and guide the light in the described LGP with the opposed mask of light-emitting face, the photo-emission part that reflects with light and penetrate from light-emitting face to guiding, between described par and described photo-emission part, be provided with the directive property transformation component of the directive property that can improve the light that incides described photo-emission part, when watching perpendicular to the direction of the light-emitting face of described LGP, the width of described directive property transformation component is positioned at than extended line and the described photo-emission part of described photo-emission part near the par of the position of light source side and intersects smaller or equal to 4 times of the width of described photo-emission part.In the present invention, so-called directive property is meant that also the photometric distribution of light is more than or equal to the width of the angle in its zone of peaked 1/2, and perhaps luminosity is the width more than or equal to the angle in its zone of peaked 1/10, during the narrowed width of this directive property, directive property improves.

As second planar light source device of the present invention, in the photo-emission part, be arranged in than the extended line of par zone near the position in the outside, by hindering light to limit the angle of the light of incident with the par, be arranged in than the extended line of par zone near inboard position, because par and photo-emission part are separated by a distance, so the angle of the light of incident is limited.Its result can improve the directive property of the light that incides photo-emission part, can also improve the directive property of the light that is reflected by photo-emission part and penetrate from light outgoing portion.Thus,, then can reduce from LGP, the picture of image display device is brightened to the light that useless direction penetrates if this planar light source device is used in the backlight or preceding irradiation etc. of image display device.

In certain embodiment of of the present invention first or second planar light source device, described directive property transformation component is arranged between described par and the described photo-emission part, and becomes the zone of the not incident of light that guides in described LGP.But, in this embodiment, do not have too big problem even the scattered light that produces by photo-emission part etc. do not incide the directive property transformation component yet.In this embodiment, because par and photo-emission part are separated by the directive property transformation component of the not incident of light that guides in LGP, be limited so incide the angle of the light of photo-emission part, directive property improves.

In another embodiment of of the present invention first or second planar light source device, described directive property transformation component is arranged between described par and the described photo-emission part, and becomes make the unreflecting zone of the light that guides in described LGP.At this, what is called does not reflect light and is meant, is absorbed light or is made outside its situation about seeing through by the directive property transformation component, also comprises making the light expansion not to the catoptrical situation of specific direction.In this embodiment, the light that guides in LGP is not reflected, improve so incide the directive property of the light of photo-emission part owing to making at the directive property transformation component.

In the another embodiment of of the present invention first or second planar light source device, described directive property transformation component is arranged between described par and the described photo-emission part, and described directive property transformation component is reverberation as follows: the light of directed property transformation component reflection is littler than light that incides the directive property transformation component and light-emitting face angulation with the light-emitting face angulation.In this embodiment, can incide the incidence angle of the light of photo-emission part, improve the directive property of the light that incides light-emitting face, so can improve from the directive property of the light of light-emitting face ejaculation by the control of directive property transformation component.

Further, in Last embodiment, more preferably, when watching perpendicular to the direction of the light-emitting face of described LGP, the width of described directive property transformation component is smaller or equal to 2 times of the width of photo-emission part.According to this embodiment, can make the optimised of directive property transformation component, can make directive property preferably light penetrate from light-emitting face effectively.

Further, in Last embodiment, described directive property transformation component is formed by first inclined plane, and first inclined plane is more outstanding laterally than described par.According to this embodiment, compared with the situation of the plane reflection that is parallel to tabular surface by the light of first inclined plane reflection, incide photo-emission part with less incidence angle, the directive property that therefore incides the light of light entrance face narrows down.And first inclined plane is not limited to the plane, can also be curved surface.At this, said incidence angle is meant, the angle that records from the normal direction of the face of the incident of light.

Further, described first inclined plane in the Last embodiment is preferably, and is more than or equal to 10 degree and smaller or equal to 25 degree with respect to the inclination angle of its par.By making as the inclination angle on first inclined plane of directive property transformation component to more than or equal to 10 degree and smaller or equal to 25 degree, can make first to optimize with the inclination angle on inclined plane, can improve the directive property of the light that penetrates from light-emitting face.

Further, in Last embodiment, described photo-emission part is formed by second inclined plane, also can be for spending more than or equal to 30 degree and smaller or equal to 60 with respect to the inclination angle of its par.To change to as the angle on second inclined plane of photo-emission part when spending more than or equal to 30 degree and smaller or equal to 60, can be in certain scope with directive property preferably light penetrate to any direction.

In addition, in the described embodiment that give prominence to laterally than described par on first inclined plane, further, form described photo-emission part, near second inclined plane, be provided with the light that makes through second inclined plane and reenter the 3rd inclined plane that is mapped in the LGP by second inclined plane.According to this embodiment, because being reentered, the light of the leakage that sees through second inclined plane is mapped in the LGP, so can improve the utilization ratio of the light of planar light source device.And, when this planar light source device is used as the preceding irradiation of image display device, can reduce the stray light that leaks from second inclined plane, improve the contrast of the picture of image display device.

Further, in Last embodiment, being preferably and making described first inclined plane is more than or equal to 10 degree and smaller or equal to 25 degree with respect to the inclination angle of described par.By the inclination angle on first inclined plane being determined in such scope, realize optimization, can improve from the directive property of the light of light-emitting face ejaculation, can reduce the useless light that leaks to tilted direction from light-emitting face.More preferably, making described second inclined plane is more than or equal to 30 degree and smaller or equal to 60 degree with respect to the inclination angle of described par, and making described the 3rd inclined plane is more than or equal to 80 degree with respect to the inclination angle of described par.In such scope, the inclination angle on second inclined plane is suitably changed, the higher light of directive property is penetrated to any direction.And, optimize with scope as described above by the inclination angle that makes the 3rd inclined plane, the light that leaks from second inclined plane is reentered be mapped to LGP and reduce stray light.

In addition, will make the light that sees through second inclined plane reenter the 3rd inclined plane that is mapped in the LGP be arranged on second inclined plane near described embodiment in, described the 3rd inclined plane can also be more outstanding laterally than the extended line of par, and described flat part is in than the position of the 3rd inclined plane near light source side.According to this embodiment, the light that sees through second inclined plane is reentered from the 3rd inclined plane be mapped in the LGP, can improve the utilization ratio of light.And, as under the situation of preceding irradiation, can reduce stray light and improve the contrast of the picture of image display device.

Further, in a last embodiment, the side away from described light source on described the 3rd inclined plane is provided with the 4th inclined plane away from the par of light source side that connects the 3rd inclined plane and be positioned at the 3rd inclined plane.In this embodiment, owing to can penetrate by the reflection of the 4th inclined plane and from light-emitting face reenter the light that is mapped in the LGP from the 3rd inclined plane, so can improve the utilization ratio of light.And the 4th inclined plane can also be a curved surface.

Further, the light source side away from the 3rd inclined plane be provided with the 4th inclined plane that connects the 3rd inclined plane and par in embodiment, the 4th inclined plane be to spend more than or equal to 30 degree and smaller or equal to 50 with respect to the inclination angle of described par.According to this embodiment, with consistent, can be improved from the directive property of the light of light-emitting face ejaculation by the direction of light of reflection of second inclined plane and ejaculation by the direction of light of reflection of the 4th inclined plane and ejaculation.

In addition, be provided with in the described embodiment on the 4th inclined plane that connects the 3rd inclined plane and par in the side away from described light source on the 3rd inclined plane, described the 4th inclined plane is contained in watches from the light that guides in LGP is the zone of shady spot on second inclined plane.According to this embodiment, can prevent that the light that guides is directly incident on the 4th inclined plane and is reflected in LGP, can prevent owing to directive property being reduced by the light of the 4th inclined plane reflection.Perhaps, can prevent that the light that guides is directly incident on the 4th inclined plane and sees through the 4th inclined plane, can prevent the loss of light or the generation of stray light in LGP.

In addition, on the 3rd inclined plane than being arranged in than the 3rd inclined plane near the outstanding laterally described embodiment of the extended line of the par of the position of light source side, the projecting height on described the 3rd inclined plane is preferably set to, and the light that guides in LGP with maximum leaded light angle can see through the lower end on described second inclined plane and incide the height on the 3rd inclined plane.According to this embodiment, can make to see through second inclined plane and substantially all incide the 3rd inclined plane and utilize again to the light of external leaks.Therefore, can reduce the light that leaks and become stray light from second inclined plane, and, the utilization ratio of light can further be improved.

In the another embodiment of of the present invention first or second planar light source device, described light source is a spot light, watch from direction perpendicular to the light-emitting face of described LGP, described photo-emission part has the directionality of length direction, and is to be centered close to the vertical straight line of the length direction of each photo-emission part on the same circumference to intersect at a point in fact with described spot light.According to this embodiment, can make the expansion and penetrate to any direction equably on light-emitting face of the light that penetrates from spot light from light-emitting face, and, the directive property of the light that penetrates from light-emitting face is improved.

In the another embodiment of of the present invention first or second planar light source device, described light source is a spot light, watch from direction perpendicular to the light-emitting face of described LGP, described photo-emission part has the directionality of length direction, and the length direction of photo-emission part is vertical with the direction that is connected this photo-emission part and light source in fact.According to this embodiment, can make the expansion and penetrate equably on light-emitting face of the light that penetrates from spot light from light-emitting face, and, the directive property of the light that penetrates from light-emitting face is improved.

Image display device of the present invention has of the present invention first or second planar light source device and the image display panel.And electronic equipment of the present invention has image display device of the present invention as display.Therefore, can provide positive directive property better and front face brightness is higher, bright display.And, planar light source device is being used as under the situation of preceding irradiation, can improve the contrast of picture.

Method for information display of the present invention is characterised in that, uses electronic equipment of the present invention, demonstration information on the display of this electronic equipment.According to this method for information display, can on the display of electronic equipment, carry out the higher and bright demonstration of front face brightness.

And the inscape of above explanation of the present invention can make up arbitrarily within the bounds of possibility.

Description of drawings

Fig. 1 is illustrated in the summary sectional view that LGP forms the existing planar light source device of recessed pattern.

Fig. 2 is the summary sectional view of recessed pattern that amplifies the planar light source device of presentation graphs 1.

Fig. 3 is the figure that the relation of the luminosity of the light in the LGP and leaded light angle φ 1 is incided in expression.

Fig. 4 is the figure that the relation of the luminosity of light of recessed pattern and incident angle φ 2 is incided in expression.

The figure of the luminosity of Fig. 5 light that to be expression penetrate from light-emitting face and the relation of shooting angle φ 3.

Fig. 6 is the figure of the definition of the leaded light angle φ 1, the incident angle φ 2 that use in Fig. 3 to Fig. 5 of explanation and shooting angle φ 3.

Fig. 7 is the figure of problem points of the planar light source device of key diagram 1.

Fig. 8 is the figure of problem points of the planar light source device of key diagram 1.

Fig. 9 is the figure that the light of the recessed pattern in the conventional example of Fig. 1 is incided in expression.

Figure 10 is expression with the summary sectional view of the existing planar light source device that is formed by prismatic pattern with opposed of light-emitting face of LGP.

Figure 11 is at summary sectional view LGP and existing planar light source device opposed the leg-of-mutton convex pattern of formation of light-emitting face.

Figure 12 is the figure of explanation problem points during as preceding irradiation with the planar light source device of Figure 11.

Figure 13 is the stereogram of the planar light source device of expression embodiments of the invention 1.

Figure 14 is the figure of the behavior of the summary sectional view of planar light source device of expression embodiment 1 and the light in the LGP.

Figure 15 is the sectional view that amplifies the deflection pattern in the planar light source device of representing embodiment 1.

Figure 16 be explanation in embodiment 1, incide the figure of behavior of the light of deflection pattern.

Figure 17 is the Action Specification figure of the directive property transformation component of embodiment 1.

Figure 18 is the Action Specification figure of the directive property transformation component of embodiment 1.

Figure 19 is the figure of relation of half breadth of the luminosity of the light that penetrates with respect to the ratio D/W of the width of photo-emission part with from light-emitting face of the width of expression directive property transformation component 30.

Figure 20 is the summary sectional view of the variation of expression embodiment 1.

Figure 21 is the stereogram of the planar light source device of expression embodiments of the invention 2.

Figure 22 is the summary sectional view of the planar light source device of embodiment 2.

Figure 23 is the Action Specification figure of the directive property transformation component among the embodiment 2.

Figure 24 is the figure of photometric distribution that the light of photo-emission part is incided in expression, and thick line represents to be provided with the photometric distribution in the present embodiment of directive property transformation component, and fine rule represents not have the photometric distribution of the conventional example of directive property transformation component.

The figure of the photometric distribution of Figure 25 light that to be expression penetrate from light-emitting face, thick line represent to be provided with the photometric distribution in the present embodiment of directive property transformation component, and fine rule represents not have the photometric distribution of the conventional example of directive property transformation component.

Figure 26 changes the inclined angle alpha of directive property transformation component, and obtains the half breadth of photometric distribution of the light that penetrates from light-emitting face and the figure that draws.

Figure 27 changes the inclined angle alpha of directive property transformation component, obtains the figure that draws from the light beam of the light that penetrates to the direction of shooting angle φ 3=-30 degree～+ 30 degree perpendicular to the direction of light-emitting face.

Figure 28 is the figure of the optimum size example of the expression deflection pattern of embodiment 2 and directive property transformation component.

Figure 29 is the summary sectional view of the variation of expression embodiment 2.

Figure 30 is the summary sectional view of other variation of expression embodiment 2.

Figure 31 is the summary sectional view of the another variation of expression embodiment 2.

Figure 32 is that the figure of the method for the overhang δ of the plane of incidence is again determined in explanation.

Figure 33 is the summary sectional view of the another variation of expression embodiment 2.

Figure 34 is the sectional view of a part of the planar light source device of expression embodiments of the invention 3.

Figure 35 be explanation in embodiment 3, the figure that determines to record to the method for the height of the upper end of photo-emission part from the upper end of reflecting surface again.

Figure 36 is the figure of the optimal values example of expression embodiment 3.

Figure 37 is the summary sectional view of the variation of expression embodiment 3.

Figure 38 is the summary sectional view of other variation of expression embodiment 3.

Figure 39 is the stereogram of the planar light source device of expression embodiments of the invention 4.

Figure 40 is the summary sectional view of the planar light source device of embodiment 4.

Figure 41 is the figure that is used to illustrate the effect of embodiment 4.

Figure 42 is the summary sectional view of the variation of expression embodiment 4.

Figure 43 is the stereogram of the planar light source device of expression embodiments of the invention 5.

Figure 44 be used to illustrate embodiment 5 light source effect sectional view and amplify the figure of its part of expression.

Figure 45 is the stereogram of expression embodiments of the invention 6.

Figure 46 is illustrated among the embodiment 6, is formed on the figure of the configuration of the deflection pattern of lower surface of LGP and directive property transformation component.

Figure 47 is the stereogram of the deflection pattern watched from LGP inside.

Figure 48 (a) and (b) be explanation in embodiment 6, incide the deflection pattern light directive property and be deflected the figure of directive property of the light of pattern reflection.

Figure 49 is the plane of other shapes of expression deflection pattern.

Figure 50 is the plane of the another configuration of expression deflection pattern.

Figure 51 is the skeleton diagram of the variation of expression embodiment 6.

Figure 52 is with the sectional view of planar light source device of the present invention as liquid crystal indicator backlight.

Figure 53 is with the sectional view of planar light source device of the present invention as the liquid crystal indicator of preceding irradiation.

Figure 54 is the summary sectional view of other examples of expression liquid crystal indicator.

Figure 55 is that expression is with the stereogram of liquid crystal indicator of the present invention as the portable phone of display.

To be expression use mobile device with liquid crystal indicator of the present invention as carrying of the PDA of display etc. to Figure 56.

Label declaration

21: light source; 22: LGP; 23: light entrance face; 24: light-emitting face; 25: the deflection pattern; 25a: photo-emission part; 25b: the plane of incidence again; 28: the par; 30: the directive property transformation component; 32: differential adjustment part; 33: reflecting surface again.

The specific embodiment

Below, with reference to the accompanying drawings embodiments of the invention are explained.But the present invention is not limited to the embodiment of following explanation, in the scope that does not break away from technical conceive of the present invention, also can apply change arbitrarily.

(embodiment 1)

Figure 13 is the stereogram of the planar light source device of expression one embodiment of the present of invention.Figure 14 is the figure of the behavior of expression summary sectional view of this planar light source device and the light in the LGP.Figure 15 is the sectional view that amplifies near the LGP of expression deflection pattern.This planar light source device is made of light source 21 and LGP 22.Light source 21 extends along the length direction of a side (light entrance face 23) of LGP 22, forms so-called linear light source.As this light source 21, can adopt cold-cathode tube, can also make the light of light emitting diode (LED) be present situation and expand and carry out linear light sourceization, also a plurality of LED can be wire and arrange and carry out linear light sourceization.LGP 22 forms tabular by polycarbonate resin or methacryl resin, glass material etc. are transparent and refractive index is high material.Lower surface at LGP 22 is formed with a plurality of tiny deflection patterns 25.Deflection pattern 25 has photo-emission part 25a, this photo-emission part 25a with the light in the LGP 22 to light-emitting face 24 lateral reflections, as the pattern of the lower surface of LGP 22, so long as it is just passable to be provided with the par discontinuously in the side away from light source 21 of photo-emission part 25a.That is, so long as recessed pattern beyond the convex pattern that illustrated in the prior art or prismatic pattern etc. get final product.In this embodiment, as following, form the deflection pattern 25 of recessed pattern-like.

It is triangle that deflection pattern 25 forms the cross section by the lower surface depression that makes LGP 22, is arranged in parallel along the width and the light entrance face 23 of LGP 22.Deflection pattern 25 is by constituting towards the photo-emission part 25a of light source 21 sides (pattern reflecting surface) with towards the 25b of the plane of incidence again with light source 21 opposition sides.Photo-emission part 25a be have will be in LGP 22 zone of the function that penetrates to light-emitting face 24 reflections and from light-emitting face 24 of the light of guiding, its angle of inclination beta be to spend more than or equal to 30 degree and smaller or equal to 60 with respect to par 28.The inclination angle γ of plane of incidence 25b is more than or equal to 80 degree and smaller or equal to 90 degree again.And in order to make the luminosity homogenising of the light that penetrates from the light-emitting face 24 of LGP 22, deflection pattern 25 is diminishing near pattern density in the zone of light source 21, and along with away from light source 21, it is big that pattern density becomes gradually.

As this deflection pattern 25, the part of photo-emission part 25a is positioned at the position than the inboard of the close LGP 22 of extended line of the par 28 that is in light source side, becomes recessed pattern.And, intersect near the extended line and the photo-emission part 25a of the par 28 of light source side than photo-emission part 25a.

In addition, so-called par 28 is to have to make from light entrance face 23 to incide the light reflection in the LGP 22 and guide, make LGP 22 interior light to be the zone of the function of planar expansion, 50% or the above light that incide the light of par 28 are reflected by par 28, are not directly incident on photo-emission part 25a afterwards but incide light-emitting face 24 and be directed.

And then the photo-emission part 25a of deflection pattern 25 extends downwards, is provided with directive property transformation component 30 between the par 28 of photo-emission part 25a and LGP 22 lower surfaces.Directive property transformation component 30 plays the effect that the directive property that will incide the light of deflection pattern 25 narrows down.In this embodiment, the zone of not incident of light of guiding is the directive property transformation component in LGP 22, makes the part zone on the inclined plane that photo-emission part 25a prolongs and comprises vertical plane between the par 28 that is in this zone and LGP 22 lower surfaces and the zone of the bottom surface of level constitutes directive property transformation component 30.

But in this planar light source device, as shown in figure 14, the light 31 that penetrates from light source 21 incides LGP 22 from light entrance face 23, total reflection and to the direction guiding away from light source 21 between the upper surface of LGP 22 and lower surface.Way therein, incide deflection pattern 25 photo-emission part 25a light 31 as shown in figure 16, by photo-emission part 25a to the reflection of the direction of light-emitting face 24 approximate vertical, see through light-emitting face 24 and penetrate to the outside from light-emitting face 24.

In addition, the light 31 that as shown in figure 16, incide in the light of photo-emission part 25a, sees through photo-emission part 25a sees through plane of incidence 25b again and gets back in the LGP 22, utilizes again.Thus, can reduce the loss of light, improve the utilization ratio of light.And, under the situation of the preceding irradiation that is used as liquid crystal indicator, be difficult to reduce the contrast of picture owing to the light that leaks from photo-emission part 25a.And, part from the light that photo-emission part 25a penetrates does not incide plane of incidence 25b and scattering again, be used as under the situation backlight, if dispose reflector plate (not shown) opposed to each other with the lower surface of LGP 22, the light that then sees through photo-emission part 25a and do not incide plane of incidence 25b again also can be reflected the sheet reflection and reenter and be mapped in the LGP 22, can further reduce the loss of light.

And then, according to planar light source device of the present invention, can improve from the directive property of the light of light-emitting face 24 ejaculations.In the present invention, so-called directive property is meant that the photometric distribution of light is more than or equal to the width of the angle in its zone of peaked 1/2, and perhaps luminosity is the width more than or equal to the angle in its zone of peaked 1/10, so-called directive property raising is meant the narrowed width of this directive property.Below, for the reason that can improve the directive property of emergent light according to the present invention, with the conventional example of Fig. 1 relatively and describe.

Fig. 9 is the light that the recessed pattern 15 in the conventional example of Fig. 1 is incided in expression.In the prior embodiment, light 31 from various angles to photo-emission part 15a incident.From the state of the light of light 31 shown in dotted lines in Figure 9 as can be known, the light of injecting in these light, from direction photo-emission part 15a down by photo-emission part 15a reflection after, penetrate to tilted direction with the shooting angle bigger with respect to the normal direction of light-emitting face 14.Its result, in the photometric distribution of as shown in Figure 5 conventional example, as illustrating, the luminosity of the light that penetrates to tilted direction becomes big, the directive property variation.

See Fig. 9 more as can be known, the light 31 that incides photo-emission part 15a from the below by par 18 reflections after, incide photo-emission part 15a at once.Especially, from inciding photo-emission part 15a, and near photo-emission part 15a, reflected to the light that tilted direction penetrates with big shooting angle by par 18 from light-emitting face 24 with the side of being directed upwardly of photo-emission part 15a almost parallel.

Relative therewith, under the situation of this embodiment of the present invention,, narrow down so incide the directive property of the light of photo-emission part 25a owing between par 28 and photo-emission part 25a, be provided with directive property transformation component 30.Its result is reflected by photo-emission part 25a and the directive property of the light that penetrates from light-emitting face 24 improves.Figure 17 and Figure 18 are concrete expression improves the reason of directive property by directive property transformation component 30 figure.The position that Figure 17 represents to incide among the photo-emission part 25a, intersect than the extended line with par 28 is near the light in the zone of top 31.The light that dots in the figure is, by the reflection of existing par and from the light of light-emitting face to penetrate to tilted direction than big shooting angle, but owing to do not have par 28 in the zone that is provided with directive property transformation component 30, so in Figure 17, do not incide photo-emission part 25a by the light shown in the dotted line 31.Therefore, the incident angle that incides the light of photo-emission part 25a is limited, and the directive property that incides the light of photo-emission part 25a narrows down.

In addition, Figure 18 position of representing to incide among the photo-emission part 25a, intersecting than the extended line with par 28 is near the light in the zone of below 31.In this case, because directive property transformation component 30 becomes the in the shade of par 28, so can not incide photo-emission part 25a from the light 31 of below, the directive property that incides the light 31 of deflection pattern 25 is limited significantly.Its result, the directive property that incides the light of photo-emission part 25a narrows down, and the directive property of the light 31 that penetrates from light-emitting face 24 also narrows down.

Therefore,, can improve from the directive property of the light of light-emitting face 24 ejaculations, and can reduce the light that penetrates to tilted direction, improve front face brightness according to this embodiment.And, under the situation as the backlight or preceding irradiation of liquid crystal indicator etc., can make the visuognosis of picture good.And,,,, can also make the with low cost of planar light source device simultaneously so can realize the slimming of planar light source device owing to can not need to improve the prismatic lens of the directive property of the light that penetrates from light-emitting face 24 according to this embodiment.

And the height of directive property transformation component 30 is so long as directive property transformation component 30 becomes in the shade such height of par 28 gets final product.That is, as long as the light that makes directive property transformation component 30 have maximum leaded light angle does not incide the height of the bottom surface 30a of directive property transformation component 30.For example, as shown in figure 15, the height of directive property transformation component 30 is made as H, the width of directive property transformation component 30 (will be defined as the width of directive property transformation component 30 smaller or equal to the width in the zone of the not incident of light of the leaded light angle of maximum leaded light angle φ 1max in this embodiment.) be made as D, the width of the bottom surface 30a of directive property transformation component 30 is made as d, the angle of inclination of photo-emission part 25a is made as β, when maximum leaded light angle is made as φ 1max (for example being 41 degree), for

H=D (tan φ 1max+tan β)-dtan β ... (A) formula.

In addition, the width D of directive property transformation component 30 is preferably, smaller or equal to 4 times of the width of photo-emission part 25a (width of the photo-emission part 25a that records in the direction parallel with the lower surface of LGP 22) W.As can be seen from Figure 17, if make the width D of directive property transformation component 30 bigger, the effect that then limits the angle of the light that incides photo-emission part 25a from the below increases, and the directive property that incides the light of photo-emission part 25a uprises.Figure 19 is at the width of the directive property transformation component 30 ratio D/W with respect to the width of photo-emission part 25a, the figure of the half breadth of the luminosity of the light that expression is penetrated from light-emitting face 24.From this figure also as can be known, if make the width D of directive property transformation component 30 become big, then the half breadth of emergent light diminishes, and directive property improves.But, according to Figure 19, if than D/W smaller or equal to 4, then half breadth changes significantly, and if surpass 4 than D/W, then after the variation of half breadth diminish, linearly change.

On the other hand, if make the width D of directive property transformation component 30 too big, then the projecting height H of directive property transformation component 30 becomes big (with reference to above-mentioned (A) formula), so photo-emission part 25a becomes big from the outstanding area of the lower surface of LGP 22.Therefore, the light through deflection pattern 25 no longer incides plane of incidence 25b and the easy scattering that becomes again.Thus, the width D of directive property transformation component 30 is preferably, smaller or equal to 4 times of the width W of photo-emission part 25a.In addition, when the width D of directive property transformation component 30 during smaller or equal to 2 times of the width W of photo-emission part 25a, stray light in the time of making as preceding irradiation can tail off, so the width D of directive property transformation component 30 is more preferably smaller or equal to 2 times of the width W of photo-emission part 25a.

And, under the width D of directive property transformation component 30 1/5 situation smaller or equal to the width W of photo-emission part 25a, because the half breadth of directive property only improves about 10%, so the width D of directive property transformation component 30 is preferably more than 1/5 of the width W that equals photo-emission part 25a.

The cross section of having represented directive property transformation component 30 in the above-described embodiments is the structure of stupefied shape, but in order to obtain the effect of the foregoing description, light must incide in the directive property transformation component 30, so directive property transformation component 30 is not limited to such shape.Figure 20 is the variation of the foregoing description, and directive property transformation component 30 forms with the bigger inclined plane of gradient.When the maximum leaded light angle of the light that will guide in LGP 22 is made as φ 1max (for example being 41 degree), be the angle (for example be 42 degree) bigger than φ 1max as long as make the angle of inclination of the directive property transformation component 30 that constitutes by the inclined plane.

And in this embodiment, the light of guiding does not incide in the directive property transformation component 30 in LGP 22, but can incide in the directive property transformation component 30 by the light of deflection pattern 25 scatterings such as grade yet.

(embodiment 2)

Figure 21 is the stereogram of the planar light source device of expression other embodiment of the present invention.And Figure 22 is the summary sectional view of this planar light source device.In this embodiment, between the photo-emission part 25a and par 28 of deflection pattern 25, constitute directive property transformation component 30 by inclined plane (first inclined plane).Figure 23 is the sectional view that amplifies the shape of expression deflection pattern 25 and directive property transformation component 30.In this embodiment, photo-emission part 25a (second inclined plane) also prolongs to lower face side slightly, directive property transformation component 30 forms by be provided with the inclined plane between the photo-emission part 25a after par 28 and the prolongation, and this inclined plane is also more outstanding to lower face side than the extended line of par 28.

In this embodiment, deflection pattern 25 is also introduced near the top than the extended line of par 28 and is formed recessed pattern, and the extended line of par 28 and photo-emission part 25a intersect.Directive property transformation component 30 plays the effect that the directive property that makes the light that incides deflection pattern 25 narrows down, but in this embodiment, has improved by incided the directive property of the light of photo-emission part 25a by directive property transformation component 30 reverberation.

But,, as shown in figure 23, can improve the directive property of the light that incides photo-emission part 25a as the directive property transformation component 30 that constitutes by such inclined plane.That is, ground tilts because directive property transformation component 30 descends below photo-emission part 25a side direction, so incided photo-emission part 25a by the light of this directive property transformation component 30 reflections little incidence angle with the time than the plane reflection that is parallel to par 28, thereby the expansion of inciding the light of photo-emission part 25a narrows down, and directive property improves.Its result, the directive property of the light that penetrates from light-emitting face 24 also improves.

Deflection pattern 25 is by photo-emission part 25a and to form the cross section at its opposed plane of incidence again of side 25b (the 3rd inclined plane) away from light source 21 be leg-of-mutton shape.Therefore, the light 31 that sees through photo-emission part 25a incides in the LGP 22 from plane of incidence 25b again, utilizes again.Thus, the loss of light reduces, and the light utilization ratio improves.And, as under the situation of preceding irradiation, the ejaculation of stray light is reduced this planar light source device, so, the contrast of the picture of liquid crystal indicator is improved.

Figure 24 is the figure of photometric distribution that the light of photo-emission part 25a is incided in expression, and thick line represents to be provided with the photometric distribution in the present embodiment of directive property transformation component 30, and fine rule represents not to be provided with the photometric distribution (identical with Fig. 4) of the conventional example of directive property transformation component.And, Figure 25 is the figure of expression from the photometric distribution of the light of light-emitting face 24 ejaculations, thick line represents to be provided with the photometric distribution in the present embodiment of directive property transformation component 30, and fine rule represents not to be provided with the photometric distribution (identical with Fig. 5) of the conventional example of directive property transformation component.At this, the maximum of leaded light angle is ± 41 degree, and the definition of leaded light angle φ 1, incident angle φ 2 and shooting angle φ 3 as shown in Figure 6.And, owing to incide the influence that the photometric distribution of the light in the LGP is not subjected to directive property transformation component 30, no matter be the present embodiment that is provided with directive property transformation component 30, or conventional example all is a photometric distribution as shown in Figure 3.

If photometric distribution is defined as directive property for the width more than or equal to its zone of peaked 1/10, then according to Figure 24 as can be known, the present embodiment that is provided with directive property transformation component 30 is compared with comparative example, and directive property increases substantially.

And according to Figure 25, in the conventional example that does not have directive property transformation component 30, the photometric distribution of emergent light is a maximum with the direction of φ 3=0 degree, near the direction away from light source 21 expands to φ 3=90 degree.On the other hand, under the situation of the present embodiment with directive property transformation component 30, the photometric distribution of emergent light is a maximum with the direction of φ 3=0 degree, only expands to about 45 degree to the direction away from light source 21, can reduce the emergent light towards useless direction.

Along with the expansion of emergent light,, can set the angle of visual field arbitrarily for by width D and the inclined angle alpha optimization that makes directive property transformation component 30.If make the inclined angle alpha of directive property transformation component 30 become big, the directive property that then incides the light of photo-emission part 25a improves, and on the other hand, if inclined angle alpha is excessive, the quantitative change of light of then inciding directive property transformation component 30 is few.Therefore, in the inclined angle alpha of directive property transformation component 30, there is the scope of appropriate value.

Figure 26 changes the tilt angle alpha of directive property transformation component 30, and obtains the half breadth of photometric distribution of the light that penetrates from light-emitting face 24 and the figure that draws.And Figure 27 changes the tilt angle alpha of directive property transformation component 30, obtains the figure that draws from the light beam of the light that penetrates to the direction of shooting angle φ 3=-30 degree～+ 30 degree perpendicular to the direction of light-emitting face 24.According to Figure 26, when the inclined angle alpha of directive property transformation component 30 was spent more than or equal to 10, (that is, the situation of α=0 degree) situation was compared, and the half breadth of the photometric distribution of emergent light becomes fully little with there not being directive property transformation component 30.And, according to Figure 27, when the inclined angle alpha of directive property transformation component 30 is spent smaller or equal to 25, compare with the situation that does not have directive property transformation component 30 (that is, the situation of α=0 degree), be that the light beam of ± 30 light that penetrate with interior direction becomes greatly to shooting angle φ 3.On the other hand, if the inclined angle alpha of directive property transformation component 30 is spent more than or equal to 25, the half breadth of emergent light then shown in Figure 26 and outgoing beam shown in Figure 27 almost do not change.This is because because it is few to incide the quantitative change of light of directive property transformation component 30, institute is so that the inclined angle alpha of directive property transformation component 30 changes also that the emergent light from light-emitting face 24 is not almost influenced.As mentioned above, directive property transformation component 30 is preferably more than with respect to the inclination angle of par 28 and equals 10 degree and smaller or equal to 25 degree, directive property is improved.Especially, the inclined angle alpha of directive property transformation component 30 more than or equal to 10 degree and situations smaller or equal to 20 degree under, the Luminance Distribution of the emergent light that penetrates from light-emitting face 24 only uprises in predetermined angle, angle at other sharply diminishes, the utilization ratio of light uprises, and it is even that the lightness in the angle of visual field also becomes.

In addition, the angle of inclination beta with respect to the direction parallel with the LGP lower surface that makes photo-emission part 25a is more than or equal to 30 degree and smaller or equal to 60 degree, thereby, the directive property variation ground that can not make the light that incides photo-emission part 25a can penetrate the high light of directive property from light-emitting face 24 towards any direction to light-emitting face 24 reflections.Especially, hope from light-emitting face 24 under the situation of vertical direction converging light, preferably making angle of inclination beta is more than or equal to 40 degree and smaller or equal to 60 degree, penetrate under the situation of more light to tilted direction from light-emitting face 24 in hope, preferably making angle of inclination beta is more than or equal to 30 degree and smaller or equal to 50 degree.And, the inclination angle γ with respect to the direction parallel with the LGP lower surface of plane of incidence 25b is good more near 90 degree more again, be in fact more than or equal to 80 degree and smaller or equal to 90 degree, be mapped in the LGP 22 thereby can make to reenter more from plane of incidence 25b again through the light of photo-emission part 25a.

Figure 28 is the optimum size example of expression deflection pattern 25 and directive property transformation component 30.In this example, the inclined angle alpha of directive property transformation component 30=15 degree, the angle of inclination beta of photo-emission part 25a=42 degree, the inclination angle γ of plane of incidence 25b=85 are spent again, the width D of directive property transformation component 30=5 μ m, height H=1.3 μ m, the width W of photo-emission part 25a=6 μ m, the width K=0.36 μ m of plane of incidence 25b again, height V=4.1 μ m.

Figure 29 is the figure of the variation of this embodiment of explanation, the cross section of expression directive property transformation component 30 and deflection pattern 25.This variation is to constitute directive property transformation component 30 with curved surface, warpage face and a plurality of inclined plane, especially as shown in figure 29, watches from the lower surface outside of LGP 22, forms directive property transformation component 30 by the curved surface that becomes concave surface.To watch from the lower surface of LGP 22 outside is the mode of concave surface when forming directive property transformation component 30, can further improve the directive property of the light that penetrates from light-emitting face 24.Watch Fig. 9 as can be known, the incidence angle that is incided the light of photo-emission part 25a after 18 reflections of par depends on the position of the 28 light reflection in the par and the distance of photo-emission part 25a, incides with respect to the light of par 28 away from the position of light source 21 and penetrates sideling from light-emitting face 24 with big angle more.Thus, as this variation, if directive property transformation component 30 is formed the curved surface etc. of concavity, then incide with respect to directive property transformation component 30 away from the light of the position of light source 21 by photo-emission part 25a reflection after, near direction, so directive property further uprises perpendicular to light-emitting face 24.

Figure 30 is the figure of other variation of explanation embodiment, the cross section of expression directive property transformation component 30 and deflection pattern 25.This variation constitutes photo-emission part 25a by curved surface, warpage face and a plurality of inclined plane, watches from the lower surface outside of LGP 22, and photo-emission part 25a becomes convex.Especially as shown in figure 30, photo-emission part 25a constitutes the inclined plane by two kinds of angle of inclination beta 1 and β 2.At this, the inclination angle be the zone of β 1 be than par 28 more to outstanding zone, the outside of LGP 22, in this zone, have only light 31 direct incidents down, be reflected with the angle less with respect to the direction vertical with light-emitting face 24.And, diminish by making angle of inclination beta 1, can make in the light in the zone of inciding angle of inclination beta 1, see through this regional light and reduce, can reduce stray light.

Figure 31 is the figure of the another variation of explanation present embodiment.In this variation, the front end of plane of incidence 25b is than the more outside outstanding δ of the extended line of the par 28 that is positioned at this light source side again.Like this,, then see through the light of photo-emission part 25a and can be more caught, and reenter and be mapped in the LGP 22 by plane of incidence 25b again if make again plane of incidence 25b outstanding to lower face side.Thereby, can further improve the utilization ratio of light.And,, can reduce stray light and the contrast of picture is improved as under the situation of preceding irradiation.

The preferred outstanding length δ of plane of incidence 25b is again, the height that the most light that sees through photo-emission part 25a can be caught by plane of incidence 25b again.For this reason, shown in figure 32, be made as that (when for example, φ 1max=41 degree) light leaked from the lower end of photo-emission part 25a, can inciding again, the height of plane of incidence 25b got final product at maximum leaded light angle φ 1max.For this reason,, the width of plane of incidence 25b again is made as K, then is if the width of photo-emission part 25a is made as W

δ 〉=(W+K) tan φ 1max gets final product.

Figure 33 is the figure of the another variation of explanation present embodiment.As the variation of Figure 31,, then between the par 28 of light source side and par 28, produce differential at the opposition side of light source if the front end of plane of incidence 25b is more outside more outstanding than the extended line of the par 28 that is positioned at this light source side again.Therefore, in this variation, be provided with differential adjustment part 32 at the opposition side of the light source of plane of incidence 25b again, make between the par 28 of light source side and par 28, do not produce at the opposition side of light source differential.In example as shown in figure 33, as the inclined plane, make its inclination angle for more than or equal to 30 degree and smaller or equal to 50 degree differential adjustment part 32.

And though not shown, the directive property transformation component that directive property transformation component and embodiment 2 such modes that the light of incident is uprised with directive property of embodiment 1 such not incident of light can also be reflected combines.

(embodiment 3)

Figure 34 is the sectional view of a part of the planar light source device of expression another embodiment of the present invention.In this embodiment, the front end of plane of incidence 25b is more outside more outstanding than the extended line of par 28 again, and, plane of incidence 25b again be formed with again reflecting surface 33 (the 4th inclined plane) away from light source side, this again reflecting surface 33 be used to make from plane of incidence 25b more again the light of incident to 24 reflections of light injection part.And by this reflecting surface 33 again, par 28 forms does not have a differential plane.

But, as shown in figure 34,, can catch the light that leaks from photo-emission part 25a efficiently by plane of incidence 25b again according to this embodiment, it is reentered be mapped in the LGP 22, can improve the utilization ratio of light, reduce stray light simultaneously.And then, in this embodiment, by by 33 reflections of reflecting surface again from the light of incident again of plane of incidence 25b again, it is penetrated to the direction perpendicular to light-emitting face 24, can further improve the directive property of planar light source device.

If make again reflecting surface 33 with respect to the inclination angle ε of par 28 for more than or equal to 30 degree and smaller or equal to 50 degree, then can make by reflecting surface 33 reflections again and from the light that light-emitting face 24 penetrates and penetrate towards the identical direction of the light that penetrates from light-emitting face 24 with being reflected by photo-emission part 25a.

In addition, in this embodiment, with respect to the light of guiding in LGP 22, reflecting surface 33 becomes the in the shade of photo-emission part 25a again.For this reason, as shown in figure 35, if the width of plane of incidence 25b is made as K again, the width of reflecting surface 33 again is made as L, the height from the upper end of reflecting surface 33 again to the upper end of photo-emission part 25a is made as Q, then (for example for maximum leaded light angle φ 1max, φ 1max=41 degree), satisfy following formula and get final product.

Q≥(K+L)tanφ1max

If the light of guiding is directly incident on reflecting surface 33 again in LGP 22, then its a part of light transmission again reflecting surface 33 leak into the outside and become loss.But, as shown in figure 35, with respect to the light of guiding in LGP 22, when making again reflecting surface 33 become photo-emission part 25a in the shade, can prevent the light that LGP 22 in, guides from reflecting surface 33 again to external leaks.Thereby, can prevent to penetrate light, and can improve the utilization ratio of light to useless direction, reduce stray light.

In addition, this embodiment can also be preferably the outstanding length of plane of incidence 25b again, and the light that sees through photo-emission part 25a almost all incides the size of plane of incidence 25b again.Thus, light through photo-emission part 25a is almost all reentered be mapped to LGP 22, can further realize the raising of utilization ratio of light and the minimizing of stray light.

Figure 36 represents the optimal values example of this embodiment.In this embodiment, establish inclined angle alpha=15 degree of directive property transformation component 30, the angle of inclination beta of photo-emission part 25a=42 degree, the inclination angle γ of plane of incidence 25b=85 degree, the inclination angle ε of reflecting surface 33=40 degree more again.And, the width D of directive property transformation component 30=5 μ m, the width W of photo-emission part 25a=6 μ m, the width K=0.64 μ m of plane of incidence 25b, the width L=3.9 μ m of reflecting surface 33 more again.At this moment, reflecting surface 33 is given prominence to δ=3.3 μ m with respect to the extended line of par 28 again.

Figure 37 represents the variation of this embodiment, constitutes reflecting surface 33 by curved surface again.Also can reduce stray light even constitute again reflecting surface 33 by curved surface.And if constitute reflecting surface 33 by curved surface shown in Figure 37, then the making of LGP 22 ratio is easier to again, and in assembling during planar light source device etc., also is difficult to collide again reflecting surface 33 even contact with miscellaneous part.

Figure 38 is the summary sectional view of other variation of this embodiment of expression, tilts by making par 28, can make par 28 have the function of reflecting surface 33 again.Therefore, in this variation, though there is not reflecting surface 33, this kind situation equally also can reduce stray light again.

(embodiment 4)

Figure 39 is the stereogram of the planar light source device of expression another embodiment of the present invention.Figure 40 is the figure of the behavior of expression summary cross section of this planar light source device and the light in the LGP.Figure 41 is the sectional view that amplifies near the LGP of expression deflection pattern.In the LGP 22 of pattern, between par 28 and deflection pattern 25, be formed with directive property transformation component 30 with prism-shaped that par 28 tilts.That is deflection pattern 25 (photo-emission part) prolongs downwards, by the inclined plane directive property transformation component 30 is set between deflection pattern 25 after being extended and the par 28.This directive property transformation component 30 plays the effect that the directive property that will incide the light of deflection pattern 25 narrows down, can be with embodiment 1 in the same manner, light in LGP 22 guiding does not incide directive property transformation component 30, can also be with embodiment 2 in the same manner, by directive property transformation component 30 reflection incident lights the directive property of the light that incides deflection pattern 25 is uprised.

For example, as shown in figure 41, because by reflecting incident lights by directive property transformation component 30, the incidence angle of the light that incides deflection pattern 25 is diminished, so can make by the light of deflection pattern 25 reflection towards the direction parallel, and the directive property of the light that penetrates from light-emitting face 24 is improved with light-emitting face 24.

In this embodiment, the extended line of par 28 and deflection pattern 25 intersect, and the angle of each face is that benchmark is determined with the plane that is parallel to par 28.For example, par 28 tilts with σ=5 degree with respect to the lower surface of LGP 22, and the extended line of directive property transformation component 30 relatively flat portions 28 has the inclination angle of α=15 degree, and the extended line of deflection pattern 25 relatively flat portions 28 has the inclination angle of β=60 degree.

Figure 42 is the variation of this embodiment, makes par 28 reverse inclinations.That is, par 28 is along with tilting near light-emitting face 24 sides ground away from light source 21.

(embodiment 5)

Figure 43 is the stereogram of expression another embodiment of the present invention, is to use the embodiment of the linear light source of LED as light source 21, and is that the parts identical with the directive property transformation component with the deflection pattern of LGP are used in embodiment in the light conductor of light source 21.Figure 44 is the plane that is used to illustrate the effect of this light source 21.Light source 21 is by constituting as the lower part: the light conductor of wedge-like (below be referred to as the wedge-like light conductor) 35, and it is formed by the higher transparent resin of refractive index; Spot light 34, the side end face of itself and wedge-like light conductor 35 relatively disposes; With normal reflection plate 36, it is configured in the back side of wedge-like light conductor 35.At this, be provided with a plurality of deflection patterns 37 that make light penetrate usefulness from the light-emitting face 35a of wedge-like light conductor 35 at the back side of wedge-like light conductor 35.And, spot light 34 is 1 or a plurality of LED to be enclosed in the transparent resin form, transparent resin is all covered by white resin except front surface, and the light that penetrates from light emitting diode is forwards penetrated expeditiously by directly or after the inside reflection by white resin.

The deflection pattern 37 of wedge-like light conductor 35 has the structure identical with the deflection pattern of the LGP that illustrated so far.For example, as shown in figure 44, deflection pattern 37 becomes the pattern of concavity with respect to the back side of wedge-like light conductor 35, by photo-emission part 37a and again plane of incidence 37b constitute.The effect that photo-emission part 37a plays the light reflection that makes incident and penetrates to almost vertical direction from the light-emitting face 35a of wedge-like light conductor 35.Plane of incidence 37b plays and makes the light that leaks from photo-emission part 37a reenter the effect that is mapped in the deflection pattern 37 again.And, the back side at deflection pattern 37, between the par 38 of photo-emission part 37a and its light source side, be provided with the directive property transformation component 39 of the directive property that is used to improve the light that incides photo-emission part 37a, directive property transformation component 39 is outstanding with respect to the back side of wedge-like light conductor 35.

And the light (lambert (Lambert) light) that penetrates from spot light 34 incides in the wedge-like light conductor 35 from the side end face of wedge-like light conductor 35.As shown in figure 44, incide light in the wedge-like light conductor 35 by the light-emitting face 35a of wedge-like light conductor and backside reflection and advance, after photo-emission part 37a reflection, almost vertically penetrate from light-emitting face 35a.

At this moment, 39 reflections of directed property transformation component and the light that incides photo-emission part 37a, improve so incide the directive property of the light of photo-emission part 37a than by the backside reflection of wedge-like light conductor 35 and little to the incidence angle of the light of photo-emission part 37a incident to the incident angle of photo-emission part 37a incident.The light that is reflected by photo-emission part 37a penetrates to almost vertical direction from the light-emitting face 35a of wedge-like light conductor 35, improve so incide the directive property of the light of photo-emission part 37a, thereby the directive property of the light that penetrates from light-emitting face 35a also improves.

In the present embodiment, the light that penetrates owing to the light-emitting face 35a from wedge-like light conductor 35 is almost vertical with the front surface of wedge-like light conductor 35, directive property is higher, so such light source 21 is being used as under the situation of linear light source, can make the light of spot light be wire expansion and ejaculation efficiently.

(embodiment 6)

Figure 45 is the stereogram of expression another embodiment of the present invention.In this embodiment, use the spot light of LED etc. as light source 21.The light source 21 of spot light shape disposes opposed to each other with the central portion of the light entrance face 23 of LGP 22.As shown in figure 46, at the lower surface of LGP 22, along showing light source 21 each circular arc configuration deflection pattern 25 for the concentric circles at center greatly, the length direction of deflection pattern 25 is parallel to and shows the tangential direction of light source 21 for the circular arc at center greatly.That is, from watching perpendicular to the direction of light-emitting face 24, each deflection pattern 25 is configured to, and connects the direction of light source 21 and this deflection pattern 25 and the length direction quadrature of this deflection pattern 25.And the pattern density of deflection pattern 25 is along with become big gradually away from light source 21.

Figure 47 is the stereogram of the deflection pattern 25 watched from LGP inside, deflection pattern 25 by photo-emission part 25a and again plane of incidence 25b constitute, be provided with directive property transformation component 30 in the light source side of photo-emission part 25a.

In this planar light source device, the light that penetrates from light source 21 is radial extension in LGP 22, is deflected pattern 25 reflections and penetrates to the direction perpendicular to light-emitting face 24.Therefore, even in such planar light source device,, can improve from the directive property of the light of light-emitting face 24 ejaculations by being provided with the directive property transformation component 30 that illustrated in the above-described embodiments.

Figure 48 (a) and (b) be the figure that expression is deflected the directive property of the light before and after pattern 25 reflection, Figure 48 (a) is the figure that watches from the direction vertical with the cross section of deflection pattern 25, Figure 48 (b) is the figure that watches from the direction vertical with light-emitting face 24.In this planar light source device, because the length direction and the direction quadrature that is connected with light source 21 of deflection pattern 25, so, shown in Figure 48 (b), under the state of watching from the direction vertical, even be deflected pattern 25 reflections, with respect to channeling direction with light-emitting face 24, directive property is expanded hardly in the horizontal, and channeling direction does not change yet.Therefore, the light of guiding is not expanded at circumferencial direction in LGP 22, has narrower directive property on this direction.Relative therewith, the light of guiding shown in Figure 48 (a), has wider directive property in the cross section perpendicular to light-emitting face 24 in LGP 22, so improve directive property in this face by directive property transformation component 30 is set, can obtain the higher front emergent light of directive property at arbitrary orientation.Therefore, according to such embodiment, make the light that penetrates from the light source 21 of spot light shape whole LGP 22 in, can both expand light equably from light-emitting face 24 towards the vertical narrower directive property of direction ejaculation.And, about the details of the function of this deflection pattern 25, open in Japanese Patent Application 2003-146925.

Figure 49 is the plane of other shapes of expression deflection pattern 25.This deflection pattern 25 is crooked along its length.The directive property of the light in the LGP 22 is because narrower at the circumferencial direction (is horizontal with respect to light conducting direction) of arranged in patterns, thus if maintained the original state in a circumferential direction the visual field of picture may narrow down.If adopt the deflection pattern 25 of such bending, the directive property of the light that is deflected pattern 25 reflections is expanded at circumferencial direction, the difference of the directive property of the directive property of radial direction and circumferencial direction is diminished, and visuognosis improves when using liquid crystal indicator.In Figure 49, make 25 bendings in wave shape of deflection pattern, but can also be as shown in figure 50, make each deflection pattern 25 towards different.

Figure 51 is the variation of present embodiment, and it is shown light source 21 greatly and be concentric circles ground configuration deflection pattern 25 for the center at the light source 21 of the bight of LGP 22 collocation point light source shape.In this variation, because light source 21 is arranged on the bight, so narrower the getting final product of extended corner of the light that penetrates from light source 21 has the advantage of the dark corners that is difficult to make LGP 22.

In addition, in the variation of Figure 51, describe when when watching perpendicular to the direction of light-emitting face 24, during with the straight line of the length direction quadrature of deflection pattern 25, deflection pattern 25 is configured to, and meets at 1 P with each straight line that with light source 21 is the length direction quadrature of each deflection pattern 25 of disposing of center on same circumference.Its result, the direction that is adjusted to the maximum luminosity that makes the light that penetrates from light-emitting face 24 is almost parallel.And, about the function of such deflection pattern 25, also open in detail in Japanese Patent Application 2003-146925.

(liquid crystal indicator)

What Figure 52 was represented is with the sectional view of planar light source device 41 of the present invention as liquid crystal indicator backlight.Planar light source device 41 is configured in the back side of permeation type liquid crystal panel 42, disposes reflector plate 44 at the back side of liquid crystal panel 42.As this liquid crystal indicator, throw light on from the back side to liquid crystal panel 42 by planar light source device 41, on liquid crystal panel 42, generate image.In such liquid crystal indicator, if adopt the application's planar light source device, then owing to can improve directive property and improve front face brightness, so the visuognosis when the front is watched improves.And the function of existing necessary prismatic lens of structure backlight or scatter plate (prevent ripple, improve brightness) the only structure by planar light source device 41 just can satisfy.Thereby, do not need one to fix on insertion prismatic lens or scatter plate between planar light source device 41 and the liquid crystal panel 42.About reflector plate 44, reflection efficiency preferably on the parts only directly installed surface light supply apparatus 41 just can satisfy this function, so not necessarily will paste reflector plate 44.

In addition, shown in Figure 53, be with the sectional view of planar light source device of the present invention 41 as the liquid crystal indicator of preceding irradiation.Planar light source device 41 is configured in the front of the liquid crystal panel 42 of reflection-type, throws light in the face of liquid crystal panel 42 in the past.The light that incides the planar light source device 41 of liquid crystal panel 42 from the front is reflected by liquid crystal panel 42 and generates image.In such liquid crystal indicator, if use the application's planar light source device, then can improve directive property and improve front face brightness, and, can improve the contrast of picture, positive visuognosis is improved.

In addition, Figure 54 represents other examples of liquid crystal indicator.In the planar light source device 41 that in this liquid crystal indicator, uses, make with light source 21 opposed light entrance faces 23 outer peripheral face in addition to be taper.Owing to make the edge of LGP 22 be taper, so arrive the very difficult ovfl of light at the edge of LGP 22 from LGP 22, light by making the edge that arrives LGP 22 can be penetrated to the liquid crystal panel side by edge reflections, improve the utilization ratio of light.

Perhaps, on the outer peripheral face beyond the light entrance face 23 of LGP 22, can also painting black coating.If painting black coating then can absorb the light at the edge that arrives LGP 22, become stray light from the ovfl of LGP 22 so can prevent light.

(electronic equipment)

Figure 55 is with the portable phone 52 of above-mentioned liquid crystal indicator 51 as display, and Figure 56 is with liquid crystal indicator 51 carrying with mobile device 53 as the PDA of display etc.These therefore easily see demonstration, and the utilization ratio of light are higher, so can suppress battery consumption owing to use above-mentioned liquid crystal indicator 51.

Claims (16)

1. planar light source device has to make from the light of light entrance face incident and propagates and LGP that penetrates from light-emitting face and the light source that is configured in the light entrance face side of LGP, it is characterized in that,

Having of described LGP with the opposed mask of light-emitting face: the par, its reflection also guides described LGP interior light and photo-emission part, and its light to guiding reflects and it is penetrated from light-emitting face,

Be provided with the directive property transformation component between described par and described photo-emission part, it makes light incide described photo-emission part after forming the light that guides in described LGP being reflected,

By described directive property transformation component light is reflected, makes that the light that is reflected by described directive property transformation component is littler than light that incides the directive property transformation component and light-emitting face angulation with the light-emitting face angulation,

When watching perpendicular to the direction of the light-emitting face of described LGP, the width of described directive property transformation component is smaller or equal to 4 times of the width of described photo-emission part,

Described directive property transformation component is formed by first inclined plane, and first inclined plane is more outstanding than described par.

2. planar light source device according to claim 1 is characterized in that,

The inclination angle with respect to described par on described first inclined plane is more than or equal to 10 degree and smaller or equal to 25 degree.

3. planar light source device according to claim 2 is characterized in that,

Described photo-emission part is formed by second inclined plane, is more than or equal to 30 degree and smaller or equal to 60 degree with respect to the inclination angle of this par.

4. planar light source device according to claim 1 is characterized in that,

Described photo-emission part is formed by second inclined plane, and formation makes the light that sees through second inclined plane reenter the 3rd inclined plane that is mapped in the LGP near second inclined plane.

5. planar light source device according to claim 4 is characterized in that,

The inclination angle with respect to described par on described first inclined plane is more than or equal to 10 degree and smaller or equal to 25 degree.

6. planar light source device according to claim 5 is characterized in that,

The inclination angle with respect to described par on described second inclined plane is more than or equal to 30 degree and smaller or equal to 60 degree, and the inclination angle with respect to described par on described the 3rd inclined plane is more than or equal to 80 degree.

7. planar light source device according to claim 4 is characterized in that,

Described the 3rd inclined plane is more outstanding than the extended line of par, and described flat part is in than the position of the 3rd inclined plane near light source side.

8. planar light source device according to claim 7 is characterized in that,

The side away from described light source on described the 3rd inclined plane is provided with the 4th inclined plane, and the 4th inclined plane connects the 3rd inclined plane and is positioned at the par away from described light source side on described the 3rd inclined plane.

9. planar light source device according to claim 8 is characterized in that,

The inclination angle with respect to described par on described the 4th inclined plane is more than or equal to 30 degree and smaller or equal to 50 degree.

10. planar light source device according to claim 8 is characterized in that,

Described the 4th inclined plane is contained in the in the shade zone that becomes second inclined plane in LGP when the light that guides is watched.

11. planar light source device according to claim 7 is characterized in that,

The projecting height on described the 3rd inclined plane is set at, and the light that guides in LGP with maximum leaded light angle can see through the lower end on described second inclined plane and incide the height on the 3rd inclined plane.

12. planar light source device according to claim 1 is characterized in that,

Described light source is a spot light, when watching perpendicular to the direction of the light-emitting face of described LGP, described photo-emission part has the directionality of length direction, and is to be centered close to the vertical straight line of the length direction of each photo-emission part on the same circumference to intersect at a point in fact with described spot light.

13. planar light source device according to claim 1 is characterized in that,

Described light source is a spot light, and when watching perpendicular to the direction of the light-emitting face of described LGP, described photo-emission part has the directionality of length direction, the length direction of photo-emission part in fact with the direction quadrature that is connected this photo-emission part and light source.

14. image display device with the described planar light source device of claim 1 and image display panel.

15. one kind with the electronic equipment of the described image display device of claim 14 as display.

16. a method for information display uses the described electronic equipment of claim 15, demonstration information on described display.

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