CN1766704A - Light guide plate and surface emitting device - Google Patents

Abstract

The invention provides a light driving plate and panel illuminating apparatus. The light driving plate has up and down two layer structure, the down layer comprises at least one light incidence panel used to receive the light from the light source and a back-light panel on the bottom panel; the up layer comprises a base plate with a light exit panel on the surface of the upper panel and the bump arrange-formed on the bottom panel near the down layer of the light driving plate on the base plate. The panel illuminating apparatus adopts the light driving plate to evenly eject the light from the light exit panel of the light driving plate. It arranges the ladder structure on the up layer bottom panel of the light driving plate which can control the light exit angle of the light exit panel.

Description

Light guide plate and surface illuminating device

[technical field]

The present invention is about a kind of surface illuminating device, particularly a kind of lobed light guide plate and surface illuminating device thereof.

[background technology]

In recent years, the flat-panel screens development has been widely used in fields such as personal computer, TV, mobile communication and consumption electronic products rapidly, becomes a large platform of infotech.Simultaneously, electronic product improves constantly the requirement of flat display apparatus (as liquid crystal indicator), and high brightness, lightening, low-cost, low energy consumption, high life become the developing direction of surface illuminating device.

According to the difference of light source placement location, surface illuminating device can be divided into direct-injection type and side-mounted two classes.Direct-injection type is meant and places light guide plate just down light source, direct illumination.The shortcoming of this based light emitting device is that thickness is bigger, does not meet current consumer to its light demand.And side-mounted surface illuminating device generally places light source the side of light guide plate, and light is coupled into light guide plate by the side, forms total reflection and constantly propagation forward in light guide plate.By destruction, realize that the light guide plate exiting surface evenly penetrates to total reflection condition.This structure is thin and light, very meeting the market requirement.Content about aspects such as the material of light guide plate, performance, principle, characteristics, see also people such as Li Haifeng in Chinese periodical " liquid crystal and demonstration ", V18 (1), 58-62 (2003), the relevant introduction in " high quality lcd with frivolous backlight technical essential " literary composition.

Please refer to Fig. 1, be the structural representation of traditional side-mounted surface illuminating device 10.Surface illuminating device 10 comprises that a light source 12, a light guide plate 11, a reflector plate 13, near light guide plate 11 bottoms are stacked and placed on the diffusion sheet 14 on the light guide plate 11 and are stacked and placed on the prismatic lens 15 that the pairwise orthogonal on the diffusion sheet 14 stacks.Wherein, light guide plate 11 comprise the incidence surface 111 that is right against light source 12, reflective bottom surface 112, the exiting surface 113 relative with reflective surface 112 and with incidence surface 111 opposing end faces 114.The light that light source 12 sends is coupled into light guide plate 11 inside by incidence surface 111, microstructure reflection through reflective surface 112, evenly penetrate from exiting surface 113, see through diffusion sheet 14 again, make the even scattering of light, import prismatic lens 15 then, light is concentrated on the normal direction of light guide plate exiting surface 113, illuminate light receiving element, promptly realize the lighting function of surface illuminating device 10.

In traditional structure shown in Figure 1, the projection of the reflective surface 112 of light guide plate 11 is a circular arc, and light causes the front-to-back ratio of exiting surface outgoing relatively poor in reflective surface generation diffuse reflection, and capacity usage ratio is lower.So need two-layer prismatic lens to improve the directivity of light, light concentrated, to the exiting surface normal direction to improve brightness.And the employing of prismatic lens has improved the cost of surface illuminating device, and also can reduce the efficiency of light energy utilization.

The 5th, 555, No. 329 patents of the U.S. that everyday announced September 10 in 1996 provide the light guide plate of the trapezoidal projection of a kind of tool, and this trapezoidal projection is fixed on the light guide plate exiting surface by inverted trapezoidal structure is gluedd joint.This structure will make down the common substrate of trapezoidal protruding neither one, make troubles to processing procedure.

The 6th, 011, No. 602 patents of the U.S. of on January 4th, 2000 bulletin provide a kind of tool that comprises to fall the light-emitting device of trapezoidal protruding light guide plate.See also Fig. 2, be the partial enlarged drawing of light guide plate projection, light guide plate 20 has a substrate 21 and is formed at projection 23 on substrate 21 exiting surfaces 22, and this projection 23 can be inverted trapezoidal structure, falls the angle theta of trapezoidal side and exiting surface 22 normals less than 10 °.Though this structure can be improved the directivity of emergent light to a certain extent, fall trapezoidal projection and light guide plate substrate to be integrated, when angle is big, be difficult to the demoulding, be unfavorable for adopting casting process to produce in batches.And angle too hour, is not enough to again the beam projecting direction is withdrawn into the exiting surface normal direction.And this light-emitting device also needs control with prismatic lens the angle of emergent light, increasing brightness, but correspondingly improved cost.

In sum, provide a kind of moulding easy, and can control the light guide plate of exiting surface beam projecting angle flexibly, and a kind of prismatic lens that need not, cost is low, and processing procedure is easy, and it is real in necessary to control the surface illuminating device of exiting surface beam projecting angle flexibly.

[summary of the invention]

To be difficult to make moulding and emergent light angle range of control little etc. not enough in order to solve in the prior art light guide plate, and it is easy to the invention provides a kind of moulding, and can control the light guide plate of emergent light angle flexibly.

Surface illuminating device needs prismatic lens in the prior art in order to solve, so that cost is too high, and outgoing side's optic angle degree range of control is little etc. not enough, and it is low to the invention provides a kind of cost, features simple structure, and can control the surface illuminating device of emergent light angle flexibly.

For realizing above-mentioned first purpose, the invention provides a kind of light guide plate, comprise an at least one reflective surface and exiting surface with respect to this reflective surface that incidence surface, that light source sends light is positioned at the bottom that be used to accept; Described light guide plate has double-layer structure up and down, the incidence surface of described light guide plate and reflective surface are formed at light guide plate lower floor, described light guide plate upper strata comprises a substrate, the exiting surface of described light guide plate is formed on this substrate surface, arrange with respect to the substrate bottom surface of described exiting surface and to be formed with projection, described protruding bottom surface is wider than in parallel and is close to the protruding end face of laminar surface under the light guide plate.

Wherein, described projection is according to thin more from the near more distribution of light source, from the more little cyclical variation series arrangement of the near more size of light source, described Cycle Length scope is between 10 microns～150 microns, described protruding end face width range is 10 microns～60 microns, the proportional range of described protruding bottom width and height of projection is 1: 2 to 2: 1, the side of described projection is the plane, folding face or curved surface, the angular range of the exiting surface normal of the side of described projection and light guide plate is 10 °～45 °, with 30 ° is good, the reflective surface of described light guide plate and/or incidence surface are arranged the V-type groove structure that is formed with by the some cycles variation in the direction perpendicular to light source, the Cycle Length scope of described V-type groove structure is between 10 microns～100 microns, and the drift angle scope of described V-type groove is 60 °～140 °.

For realizing above-mentioned second purpose, the invention provides a kind of surface illuminating device, comprise a light source, a light guide plate and a reflector plate, wherein light guide plate has an at least one reflective surface and exiting surface with respect to this reflective surface that incidence surface, that light source sends light is positioned at the bottom that be used to accept, and described reflector plate is close to the reflective surface of light guide plate; Described light guide plate has double-layer structure up and down, the incidence surface of described light guide plate and reflective surface are formed at light guide plate lower floor, described light guide plate upper strata comprises a substrate, the exiting surface of described light guide plate is formed on this substrate surface, arrange with respect to the substrate bottom surface of described exiting surface and to be formed with projection, described protruding bottom surface is wider than in parallel and is close to the protruding end face of laminar surface under the light guide plate.

Wherein, described projection according to thin more from the near more distribution of light source, from the more little cyclical variation series arrangement of the near more size of light source, described Cycle Length scope is between 10 microns～150 microns, described protruding end face width range is 10 microns～60 microns, the proportional range of described protruding bottom width and height of projection is 1: 2 to 2: 1, the side of described projection is plane, folding face or curved surface, and the angular range of the exiting surface normal of the side of described projection and light guide plate is 10 °～45 °.

Compared with prior art, light guide plate of the present invention has double-layer structure up and down, and the bottom surface of superstructure is arranged to be formed with and is similar to down trapezoidal projection, and this structure can utilize technology such as injection molding, etching, splicing to make moulding easily.Simultaneously, the inclination angle scope selectivity of this projection side is bigger, and can not influence the demoulding of light guide plate, thereby, can change by the inclination angle of this projection side, control the direction of emergent ray flexibly, make it along direction outgoing perpendicular to the light guide plate exiting surface.

And surface illuminating device of the present invention need not prismatic lens, escapable cost, make its structure easier, and by adopting the light guide plate that is similar to down trapezoidal projection provided by the present invention, can change by the inclination angle of this projection side, the direction of control emergent ray makes it along the direction outgoing perpendicular to the light guide plate exiting surface flexibly.

[description of drawings]

Fig. 1 is the surface illuminating device structural representation of prior art;

Fig. 2 is the light guide plate bulge-structure synoptic diagram of prior art;

Fig. 3 is a surface illuminating device structural representation of the present invention;

Fig. 4 is a light guide plate superstructure synoptic diagram of the present invention;

Fig. 5 is the first kind of bulge-structure synoptic diagram in light guide plate of the present invention upper strata;

Fig. 6 is the second kind of bulge-structure synoptic diagram in light guide plate of the present invention upper strata;

Fig. 7 is the third bulge-structure synoptic diagram of light guide plate of the present invention upper strata;

Fig. 8 is a light guide plate of the present invention lower floor reflective surface V-type groove structural representation;

Fig. 9 is a light guide plate of the present invention lower floor incidence surface V-type groove structural representation;

Figure 10 is a light guide plate of the present invention lower floor V-type groove structural representation;

Figure 11 is a light guide plate top substrate layer coating structure synoptic diagram of the present invention;

Figure 12 is a light guide plate of the present invention upper strata coating structure synoptic diagram;

Figure 13 is a light guide plate of the present invention lower floor coating structure synoptic diagram.

[embodiment]

Below in conjunction with accompanying drawing the present invention is described in further detail.

Seeing also Fig. 3, is surface illuminating device structural representation provided by the invention.Surface illuminating device 30 comprises a light guide plate 31, at least one a light source 32 and a reflector plate 33 near light guide plate 31 bottoms near light guide plate 31 sides.Wherein, light guide plate 31 has the levels structure, understructure have at least one near light source 32 incidence surface 311, reflective bottom surface 312, with incidence surface 312 opposing end faces 313.Superstructure comprises a substrate 34, and substrate 34 has a substrate bottom surface 341 and the exiting surface 342 with respect to substrate bottom surface 341 in the face of light guide plate lower floor at least.On substrate bottom surface 341, arrange and be formed with projection 35, and by thin more from the near more distribution of light source, from the more little cyclical variation series arrangement of the near more size of light source.Projection 35 has a protruding bottom surface 351 (as shown in phantom in FIG.), protruding end face 352 and becomes the protruding side 353 at certain inclination angle with the normal of exiting surface 342, wherein, this projection bottom surface 351 is parallel to each other with protruding end face 352, and width that should projection bottom surface 351 is greater than protruding end face 352, this projection side 353 can be plane, folding face or curved surface, and the inclination angle scope of protruding side 353 is 10 °～45 °.

Light source 32 is generally pointolite or line source, as fluorescent tube, cold cathode fluorescent lamp or light emitting diode etc., and can adopt single light source or two kinds of different forms of two light source.When adopting singlelight source 32,reflector plate 33 can adopt traditional structure, with itsreflective surface 312 and end face 313 that coatslight guide plate 31, light can not spilt from its two sides, thereby can improve the efficiency of light energy utilization.When adopting twolight sources 32, promptly when theend face 313 oflight guide plate 31 also was provided with another light source, 33 need of reflector plate covered thereflective surfaces 312 oflight guide plate 31.

Thelight 1 that sends whenlight source 32 is coupled intolight guide plate 31 inside byincidence surface 311, through the microstructure reflection ofreflective surface 312, sees through upper strataprojection end face 352 again, and byside 353 reflections ofprojection 35, the normal direction along exitingsurface 342 penetrates at last then.And light 2 can not arriveprotruding end face 352 after reflection, and at this moment, its more than 33 reflection of sheet that will be reflected in understructure up to seeing through upper strataprojection end face 352, is penetrated along the normal direction of exitingsurface 342 with light 1 then equally.These light illuminate light receiving element, promptly realize the even ejaculation ofsurface illuminating device 30.

Seeing also Fig. 4, is light guide plate 31 superstructure synoptic diagram of the present invention.With its upwards upset, so that clear light guide plate 31 superstructures that show, it comprises a substrate 34 and arranges on its substrate bottom surface 341 and forms the projection 35 that is parallel to each other, and is made by transparent material usually among the figure.Wherein should projection 35 be parallel to light source 32, tool is similar to down trapezoidal structure, and promptly protruding end face 352 width are less than the protruding bottom surface 351 (as shown in phantom in FIG.) relative with it, and protruding side 353 can be the plane, is just trapezoidal (as shown in Figure 5); Also can be the folding face (as shown in Figure 6) that a plurality of sides constitute,, select the inclination angle of projection 35 each sides, reflex to the direction of exiting surface 342 with the light of control all directions according to requirement to exiting surface 342 emergent ray directivity; Perhaps adopt curved-surface structure (as shown in Figure 7), same, according to requirement, select the shape of curved surface to exiting surface emergent ray directivity, reflex to the direction of exiting surface 342 with control light.Yet no matter which kind of type structure is projection 35 adopt, the width of its protruding bottom surface 351 and the proportional range of height of projection are 1: 2 to 2: 1, are preferably 1: 1; And the angular range of exiting surface 342 normals of protruding side 353 and substrate 34 is 10 °～45 °, is good with 30 °, to control out direction of light; The width range of projection end face 352 is 10 microns～60 microns, enters the flux of its upper strata light from light guide plate 31 lower floors with control.And, projection 35 by apart from the distance of light source 32 by dredging to close series arrangement, promptly on the near area of distance light source 32, projection 35 arrangements are sparse; And apart from light source 32 area far away, protruding 35 dense arrangements.Equally, projection 35 sizes are by the far and near ascending series arrangement apart from light source 32, and are promptly far away more at distance light source 32, and projection 35 is just big more.In addition, the big variation of projection 35 this arranging densities and size can change by certain cycle, the period of change length of this projection 35 can be a bigger scope, as 10～150 microns, as long as can avoid producing the interference of light phenomenon, or avoid human eye to see that by display screen the picture of 35 one-tenth of projectioies gets final product.By to projection 35 this variations adjustings, can realize the angle control of light guide plate to emergent light, light is evenly penetrated from exiting surface 342.

Seeing also Fig. 8,9,10, is light guide plate lower floor's reflective surface of the present invention and incidence surface V-type groove structural representation.As shown in Figure 8, thereflective surface 312 of light guide plate understructure is arranged to a plurality of V-type groove structures, and V-type groove bearing of trend is on the direction vertical with linear light source, and parallel to each other.To control light in the output angle that is parallel to the linear light source direction.The degree of depth of V-type groove generally is no more than 100 microns.Equally, also can be arranged to V-type groove structure (as shown in Figure 9) atincidence surface 311, the V-type groove is on the direction vertical with linear light source, and is and parallel to each other.According to the difference of the light source angle of divergence, the drift angle of above-mentioned two V-type grooves can change in a very big scope, as 60 °～140 °, is good with 120 °.The V-type groove also can change by some cycles, and Cycle Length can not be too little, to avoid producing the interference of light phenomenon, can not be too big, and avoid seeing the picture of V-type groove by display screen at human eye, generally be good between 10～100 microns.When simultaneouslyreflective surface 312 andincidence surface 311 all being provided with V-type groove structure (as shown in figure 10), can improve the coupling efficiency ofincidence surface 311, can improve light again and be parallel to the homogeneity of light source direction, overcome the shade phenomenon.

See also Figure 11,12,13, be respectively the coating structure synoptic diagram of light guide plate relevant surfaces of the present invention.At the bottom surface of thesubstrate 34 oflight guide plate 31 341 plating reflectance coatings (as shown in figure 11), injectlight guide plate 31 upper strata Shi Hui when extraneous light and reflected, thereby improve capacity usage ratio bybottom surface 34 reflectance coatings.Also can more reflect, prevent that light from spillinglight guide plate 31 from protrudingside 353, further improves capacity usage ratio at protrudingside 353 plating reflectance coatings (as shown in figure 12) from light from outside.

Thereflective surface 312 of this externallight guide plate 31 andend face 313 plating reflectance coatings can prevent that equally light from spilling (as shown in figure 13) from thereflective surface 312 and theend face 313 oflight guide plate 31, can savereflector plate 33, save cost, improve capacity usage ratio.

Contact with lower floor on the upper strata oflight guide plate 31 gap of interface is air or other low-refraction materials, so light can form total reflection in the light guide plate underclad portion.Thereby, when the light thatlight source 32 sends is coupled intolight guide plate 31 inside byincidence surface 311, becausereflective surface 312 andend face 313 are coated with the reflection plated film, most of light is reflected, and through upper strataprojection end face 352, further reflected by the reflection plated film of protrudingside 353, the normal direction along exitingsurface 342 penetrates at last.Other has more than 33 total reflection of sheet that be reflected of part light in understructure, up to seeing through protrudingend face 352, equally by the reflection of the plated film of protrudingside 353, and penetrate from the normal direction of exiting surface 342.By the way, promptly realize the control of emergent light angle, light is evenly penetrated from theexiting surface 342 oflight guide plate 31.

The plated film of light guide plate relevant surfaces of the present invention can adopt aluminium film or silverskin, as only usingreflector plate 33, and then can be at its catoptrical surperficial plated aluminum film or silverskin, to realize high reflection.By these reflectance coatings, also can make surface illuminating device realize transmission-type and reflective two kinds of illuminations.

Light guide plate of the present invention is generally made by the bigger transparent material of refractive indexes such as polymethacrylate, polycarbonate, and whole light guide plate can adopt methods such as injection molding, etching, splicing to make moulding easily.

Claims (11)

1. light guide plate comprises an at least one reflective surface and exiting surface with respect to described reflective surface that incidence surface, that light source sends light is positioned at the bottom that be used to accept; It is characterized in that: described light guide plate has double-layer structure up and down, the incidence surface of described light guide plate and reflective surface are formed at light guide plate lower floor, described light guide plate upper strata comprises a substrate, the exiting surface of described light guide plate is formed at this substrate surface, arrange with respect to the substrate bottom surface of described exiting surface and to be formed with projection, described protruding bottom surface is wider than in parallel and is close to the protruding end face of laminar surface under the light guide plate.

2. light guide plate as claimed in claim 1 is characterized in that: described projection according to thin more from the near more distribution of light source, from the more little cyclical variation series arrangement of the near more size of light source.

3. light guide plate as claimed in claim 2 is characterized in that: described Cycle Length scope is between 10 microns～150 microns.

4. light guide plate as claimed in claim 3 is characterized in that: described protruding end face width range is 10 microns～60 microns.

5. light guide plate as claimed in claim 4 is characterized in that: the proportional range of described protruding bottom width and height of projection is 1: 2 to 2: 1.

6. light guide plate as claimed in claim 5 is characterized in that: the side of described projection is plane, folding face or curved surface.

7. light guide plate as claimed in claim 6 is characterized in that: the angular range of the exiting surface normal of the side of described projection and light guide plate is 10 °～45 °.

8. light guide plate as claimed in claim 7 is characterized in that: the reflective surface of described light guide plate and/or incidence surface are arranged the V-type groove structure that is formed with by the some cycles variation in the direction perpendicular to light source.

9. surface illuminating device, comprise a light source, light guide plate and a reflector plate, wherein light guide plate has an at least one reflective surface and exiting surface with respect to described reflective surface that incidence surface, that light source sends light is positioned at the bottom of accepting, and described reflector plate is close to the reflective surface of light guide plate; It is characterized in that: described light guide plate has double-layer structure up and down, the incidence surface of described light guide plate and reflective surface are formed at light guide plate lower floor, described light guide plate upper strata comprises a substrate, the exiting surface of described light guide plate is formed at this substrate surface, arrange with respect to the substrate bottom surface of described exiting surface and to be formed with projection, described protruding bottom surface is wider than in parallel and is close to the protruding end face of laminar surface under the light guide plate.

10. surface illuminating device as claimed in claim 9 is characterized in that: described projection according to thin more from the near more distribution of light source, from the more little cyclical variation series arrangement of the near more size of light source.

11. surface illuminating device as claimed in claim 10 is characterized in that: the side of described projection is plane, folding face or curved surface.

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