CN101498401A - Light source structure for improving light conversion efficiency based on fluorescent powder - Google Patents

Abstract

A light source structure for improving light conversion efficiency based on fluorescent powder comprises an excitation light source (1), an excited material (3) and a heat conducting substrate (4), wherein the excited material (3) is tightly attached to the heat conducting substrate (4); the device also comprises a spectral filter (2), and particularly, the excitation light source (1) faces the spectral filter (2) to enable excitation light rays to be obliquely emitted to the spectral filter (2); the excited material (3) is substantially positively facing the excitation light guided by the spectral filter (2). And a heat-conducting reflecting mirror is added between the excited material (3) and the heat-conducting substrate (4) to improve the utilization rate of the excited light. The heat conducting substrate (4) can also be fixed on a turntable (5) for light mixing treatment. The invention has the advantages of simple structure and low cost while improving the light source efficiency.

Description

Improve the light-source structure of light conversion efficiency based on fluorescent material

Technical field

The present invention relates to light source module, relate in particular to the light source module that excites based on fluorescent material, particularly make up the improvement structure that makes the purer light source of emergent light by element.

Background technology

Since earlier 1990s, along with the new generation of semiconductor photoelectron material based on InGaAlP and InGaN develops rapidly, led light sources such as red, yellow, blue, green, the ultraviolet of various high power high luminances and white light emerge in large numbers one after another, emerge in an endless stream, obtained application more and more widely in various demonstrations and lighting field.

The method that obtains shades of colour light source (especially white light source) is except adopting the respective color light emitting diode, and the main technical schemes that can also adopt has RGB mixed light and fluorescence to change two kinds.Wherein, the fluorescence conversion plan is used to excite the light that makes fluorescent material produce longer wavelength from the emission light of other light source (such as but not limited to led chip).For example, the white light LEDs patent of Japanese Ri Ya company (Nichia) discloses and has utilized 470 nano blue light led chips to excite yellow YAG fluorescent material to send the technical scheme of white light.This scenario-frame is simple, low cost of manufacture, product have very strong practicality.

The general structure that has of light source of available technology adopting fluorescence conversion plan is that fluorescent material is coated on the light emitting source (especially luminescence chip), and for example application number is 200420084479 the disclosed scheme of Chinese patent application.Its weak point is: because the heat that luminescence chip produces is big more, big more to the launching efficiency influence of fluorescent material.Like this, raising along with excitation light power, the launching efficiency of fluorescent material is on a declining curve, thereby the luminous power that causes stimulated emission is along with after the raising of excitation light power rises to a certain degree, can improve along with the continuation of excitation light power on the contrary and the decline phenomenon occur.

At the problems referred to above, application number is that 2005100720291 Chinese patent application discloses a kind of scheme that is obtained white light by the fluorescence conversion, fluorescent material is coated on the speculum, thereby separate with light emitting diode, the light that utilizes this speculum to make fluorescent material be inspired is penetrated by predetermined exit facet by reflection.In this scheme, fluorescent material can improve the light conversion efficiency under the big excitation light power because of not being subjected to the influence of diode chip for backlight unit heating.Its weak point is: along with the continuation development of light source technology, light source output brightness and power are more and more higher, this structure has limited the further raising of light source light conversion efficiency because of having ignored the influence of the fluorescent material heat energy that gathers to light conversion efficiency under the big excitation light power itself.

U.S. Pat 7,196,354B1 discloses another scheme, and shown in Fig. 1 a or 1b:fluorescent material 3 is close to aheat conduction territory 4, and the heat energy that fluorescent material itself is produced can't gather, and has both improved light conversion efficiency, helps prolonging fluorescent material service life again.This patent is also pointed out and can be increased by an optical filter betweenexcitation source 1 andfluorescent material 3 simultaneously, is used for seeing through the light of predetermined wavelength, reflects the light of other non-predetermined wavelength simultaneously; Like this, can make stimulated luminescence obtain utilization and further improve source efficiency to the excitation source scattering.

Above-mentioned the deficiencies in the prior art part is: though U.S. Pat 7,196, the disclosed scheme of 354B1 can improve source efficiency to greatest extent, but in the disclosed light-source structure of this patent, being mapped to the exciting light that is not absorbed and used on the described fluorescent material can or reflect (shown in Fig. 1 b) exit facet ejaculation by light source by direct projection (as shown in Figure 1a), thereby is unfavorable for improving the light output purity.

Summary of the invention

The technical problem to be solved in the present invention is at above-mentioned the deficiencies in the prior art, and proposes a kind of improved light-source structure, is convenient to improve under the prerequisite of fluorescent material light conversion efficiency, obtains highly purified output light.

For solving the problems of the technologies described above, being contemplated that substantially of this reality invention: improve light-source structure, adjust the distribution of element combination, make stimulated luminescence can be directed to the light source exit facet, simultaneously with other place of the most of guiding of exciting light that do not utilized by fluorescent material, thereby under the condition of equal phosphor material powder, can obtain purer output light.

As the technical scheme that realizes the present invention's design be, provide a kind of and improve the light-source structure of light conversion efficiency that comprise excitation source, be excited material and thermal conductive substrate, the described material of being excited is close on the described thermal conductive substrate based on fluorescent material; Also comprise the beam split optical filter, especially, described excitation source makes the excitation line oblique fire to this beam split optical filter in the face of described beam split optical filter; The described material of being excited is roughly just being met to guiding the described excitation line of coming by this beam split optical filter.

In the such scheme, described beam split optical filter is arranged on described excitation source and described being excited between the material, in the mode of penetrating described excitation line is led toward the described material of being excited, will describedly be excited the light-emitting face of past this light source of photoconduction that is stimulated of material in the reflection mode simultaneously.

In the such scheme, the light-emitting face of described excitation source and described plane almost parallel of being excited the material place roughly are 45 degree inclination angles with the plane at described beam split optical filter place.

In the such scheme, the light-emitting face of described excitation source and the described material of being excited are arranged on the same side of described beam split optical filter, intersect in twos on the plane at place separately, thereby described beam split optical filter is led described excitation line toward the described material of being excited in the reflection mode, will be excited the light-emitting face of photoconduction toward this light source that be stimulated of material in the mode of penetrating simultaneously.

In the such scheme, described excitation source light-emitting face and described plane of being excited the material place be quadrature roughly, and the plane with described beam split optical filter place roughly is 45 degree angles respectively.

In the such scheme, also comprise the heat conduction speculum, be excited between material and the thermal conductive substrate between described.

In the such scheme, also comprise the transparent light guide medium, be arranged on the one or both sides of described beam split optical filter.

In the such scheme, also comprise rotating disk (5), described thermal conductive substrate (4) is fixed on this rotating disk (5) or is the some of this rotating disk card.The rotating shaft (52) that described thermal conductive substrate (4) goes up with described rotating disk (5) be the center, is excited material (31,32) along at least two kinds of circumference subregion distributions.

Thereby be convenient to the uniform color mixture design of described light source.

Adopt above-mentioned each technical scheme, in the fluorescent material light conversion efficiency of light source under improving big exciting power, can export purer light, thereby satisfy under the specific occasion requirement optical purity, and the structure that is adopted have realization simply, advantage cheaply.

Description of drawings

Fig. 1 a and 1b are the structural representations of existing light source;

Fig. 2 a and 2b are the structural principle schematic diagrames of one of light source embodiment of the present invention

Fig. 3 is the relevant spectrum exemplary plot that Fig. 2 embodiment obtains green glow,

Wherein curve a1 represents the spectrum of beam split optical filter, and curve a2 represents the spectrum of exciting light, and curve a3 represents the spectrum of stimulated luminescence;

Fig. 4 is the relevant spectrum exemplary plot that Fig. 2 embodiment obtains ruddiness,

Wherein curve b1 represents the spectrum of beam split optical filter, and curve b2 represents the spectrum of exciting light, and curve b3 represents the spectrum of stimulated luminescence;

Fig. 5 is two the structural principle schematic diagram of light source embodiment of the present invention;

Fig. 6 is the relevant spectrum exemplary plot that Fig. 5 embodiment obtains ruddiness,

Wherein curve c1 represents the spectrum of beam split optical filter, and curve c2 represents the spectrum of exciting light, and curve c3 represents the spectrum of stimulated luminescence;

Fig. 7 is the improvement structural principle schematic diagram of Fig. 2 example structure;

Label among above-mentioned each figure is: 1---excitation source; 2---the beam split optical filter; 3---be excited material/be excited material layer; 31---first is excited material; 32---second is excited material; 4---thermal conductive substrate; 5---rotating disk; 52---turntable shaft; 6---the transparent light guide medium.

The specific embodiment

Below, the most preferred embodiment shown in is further set forth the present invention in conjunction with the accompanying drawings.

Light source of the present invention comprisesexcitation source 1 at least and isexcited material 3 and thermalconductive substrate 4; The describedmaterial 3 of being excited is close on this thermalconductive substrate 4, thereby the heat that is gathered is in time conducted and spreads.In order to make the conduction of light output directional and to have higher degree, light source of the present invention also comprises a beam splitoptical filter 2, make describedexcitation source 1 in the face of this beam splitoptical filter 2, thereby the excitation line oblique fire is arranged to roughly just meeting the describedmaterial 3 of being excited to the excitation line that is come by these beam splitoptical filter 2 guiding (referring to that just described plane of beingexcited material 3 formations roughly is orthogonal to the primary optical axis of this excitation line) to this beam splitoptical filter 2 simultaneously.

According to the optical characteristics of selected beam splitoptical filter 2, the present invention includes two most preferred embodiments.One of embodiment is shown in Fig. 2 a, described beam splitoptical filter 2 is arranged on describedexcitation source 1 and described being excited between thematerial 3, in the mode of penetrating described excitation line is led toward the describedmaterial 3 of being excited, will describedly be excited the light-emitting face of past this light source of photoconduction that is stimulated ofmaterial 3 in the reflection mode simultaneously.

Fig. 2 b is the special case of Fig. 2 a, and the light-emitting face of describedexcitation source 1 and described plane almost parallel of being excited material (3) place roughly are 45 degree inclination angles with the plane at described beam splitoptical filter 2 places.Can reduce stimulated luminescence so to greatest extent and be excited material, and then will be stimulated photoconduction toward light-emitting face with the highest efficient by beam split optical filter reflected back.

Fig. 3 is the correlation spectrum exemplary plot of the foregoing description: represent the spectrum of described beam splitoptical filter 2 with curve a1, it has blue light characteristic thoroughly; Curve a2 represents the spectrum of exciting light, is blue light; Curve a3 represents the spectrum of stimulated luminescence, for example selects green glow, uses the G3560 of (but be not limited to be) Intematix company^TMFluorescent material.Utilize the wavelength gating characteristic of this beam splitoptical filter 2, described green glow stimulated luminescence is because most of wavelength, projects the light-emitting face of major part being led past this light source in the reflection mode on the described beam splitoptical filter 2 greater than 500 nanometers; Described blue-light excited light will be led in the mode of penetrating and will be mapped on the fluorescent material simultaneously.Like this, by the effect of beam splitoptical filter 2, unemployed stimulated luminescence nearly all can be through repeatedly reflection and finally penetrated by the light-emitting face of this light source under the traditional approach.

Fig. 4 utilizes the foregoing description to produce the correlation spectrum exemplary plot of ruddiness, and wherein curve b1 represents the spectrum of described beam splitoptical filter 2, and curve b2 represents the spectrum of exciting light, and curve b3 represents the spectrum of stimulated luminescence; Then only change described fluorescent material and be 05742 of (but be not limited to as) Intematix company^TMFluorescent material glows.Described ruddiness stimulated luminescence will all be reflected the light-emitting face of past light source by described beam split optical filter 2.Utilize this embodiment, can obtain the light output that utilization rate is higher, purity is purer undoubtedly.

The most preferred embodiment of light-source structure of the present invention two as shown in Figure 5: the light-emitting face of describedexcitation source 3 and the describedmaterial 3 of being excited are arranged on the same side of described beam splitoptical filter 2, intersect in twos on the plane at place separately, thereby described beam splitoptical filter 2 is led described excitation line toward the describedmaterial 3 of being excited in the reflection mode, will be excited the light-emitting face of photoconduction toward this light source that be stimulated ofmaterial 3 in the mode of penetrating simultaneously.In the figure, describedexcitation source 3 light-emitting faces and described plane of being excitedmaterial 3 places be quadrature roughly, and the plane with described beam splitoptical filter 2 places roughly is 45 degree angles respectively, can play the effect of maximal efficiency land productivity with light equally.It is other angle that this special case does not limit the angle that light-source structure of the present invention can adjust between the above-mentioned correlation plane according to actual needs.

Fig. 6 is the correlation spectrum exemplary plot of this embodiment: represent the spectrum of described beam splitoptical filter 2 with curve c1, it has ruddiness characteristic thoroughly; Curve c2 represents the spectrum of exciting light, is blue light; Curve c3 represents the spectrum of stimulated luminescence, for example selects ruddiness.Described ruddiness stimulated luminescence be because wavelength will be led light-emitting face toward this light source in the mode of penetrating after greater than 550 nanometers, projecting on the described beam splitoptical filter 2, and described blue-light excited light will be led in the reflection mode and is mapped on the fluorescent material.

In the various embodiments described above, describedexcitation source 1 can be a spot light, also can be area source (such as but not limited to led light source).If spot light, then the light-emitting face of described excitation source is meant and this spot light optical axis plane orthogonal.

Utilization rate for the light that guarantees to be stimulated can also comprise the heat conduction speculum in the various embodiments of the present invention structure, is excited betweenmaterial 3 and the thermalconductive substrate 4 between described.This heat conduction speculum can be the polished surface of described thermalconductive substrate 4, can also be based on the plated film of described thermalconductive substrate 4; The describedmaterial 3 of being excited applies or covers on this heat conduction speculum.Described heat conduction speculum or thermalconductive substrate 4 thermal conductivity at room temperature can adopt metal (such as but not limited to aluminium) or thermal conductive ceramic more preferably greater than 10W/ (m.K) (watt/meter * degree Kelvin).

In order further to reduce the loss of light, light source of the present invention can also in the one or both sides of described beam split optical filter, increase the transparent light guide medium in the various embodiments described above, described exciting light or stimulated luminescence are conducted.Only (but being not limited to) is example with Fig. 2 b and transparent light guide medium shown in dotted lines in Figure 57, can use the triangular glass column, be close to described beam splitoptical filter 2 with a side, the another side is close to the light-emitting face of describedexcitation source 1 or isexcited material 3, plays the effect of fiber waveguide in the transmission course of light.

The present invention can also carry out architecture advances based on the various embodiments described above, as being example with Fig. 7.In this light-source structure, set up a rotatingdisk 5, be used for carrying described thermal conductive substrate 4 (be fixed on this thermalconductive substrate 4 on this rotatingdisk 5 or be set to the some of this rotating disk card).Like this, in having the light-source system of ventilating fan, make this thermal conductive substrate rotation be convenient to heat radiation evenly on the one hand; Another important aspect is, with the rotating shaft is the center, distribute at least two kinds in circumference subregion, described thermalconductive substrate 4 upper edge and to be excited material (31,32), can be so that the design of the colour mixture of light source: consider that the fluorescent material of this type of application has the extremely short response time in the prior art, can think along with the rotating disk rotation, exciting light shines different stimulated luminescence materials, can obtain the stimulated luminescence of different colours.Select the suitable beam splitoptical filter 2 that can reflect these two kinds of stimulated luminescences simultaneously (do not get rid of for the different materials of being excited and use the possibility of the beam split optical filter of different optimization), then constantly in difference, stimulated luminescence color by this beam splitoptical filter 2 same positions reflection is constantly rotated, and can reach the purpose of uniform color mixture.

In fact, with the uniform color mixture is purpose, gathers under the few occasion of heat (for example less occasion of luminous power output) at described fluorescent material, and described light source can also adopt prior art to combine with rotating disk, fluorescent material is coated on the transparent rotating disk, realizes colour mixture with transmission mode.Because of non-emphasis of the present invention, do not do more elaborations.

Claims (12)

1. one kind is improved the light-source structure of light conversion efficiency based on fluorescent material, comprises excitation source (1), is excited material (3) and thermal conductive substrate (4), and the described material (3) of being excited is close on the described thermal conductive substrate (4); Also comprise beam split optical filter (2), it is characterized in that:

Described excitation source (3) makes the excitation line oblique fire to this beam split optical filter (2) in the face of described beam split optical filter (2); The described material (3) of being excited is roughly just being met to guiding the described excitation line of coming by this beam split optical filter (2).

2. according to the described light-source structure of claim 1, it is characterized in that based on fluorescent material raising light conversion efficiency:

Described beam split optical filter (2) is arranged on described excitation source (3) and described being excited between the material (3), in the mode of penetrating described excitation line is led toward the described material (3) of being excited, will describedly be excited the light-emitting face of past this light source of photoconduction that is stimulated of material (3) in the reflection mode simultaneously.

3. according to the described light-source structure of claim 2, it is characterized in that based on fluorescent material raising light conversion efficiency:

The light-emitting face of described excitation source (1) and described plane almost parallel of being excited material (3) place roughly are 45 degree inclination angles with the plane at described beam split optical filter (2) place.

4. according to the described light-source structure of claim 1, it is characterized in that based on fluorescent material raising light conversion efficiency:

The light-emitting face of described excitation source (1) and the described material (3) of being excited are arranged on the same side of described beam split optical filter (2), intersect in twos on the plane at place separately, thereby described beam split optical filter (2) is led described excitation line toward the described material (3) of being excited in the reflection mode, will be excited the light-emitting face of photoconduction toward this light source that be stimulated of material (3) in the mode of penetrating simultaneously.

5. according to the described light-source structure of claim 4, it is characterized in that based on fluorescent material raising light conversion efficiency:

Described excitation source (1) light-emitting face and described plane of being excited material (3) place be quadrature roughly, and the plane with described beam split optical filter (2) place roughly is 45 degree angles respectively.

6. according to the described light-source structure of claim 1, it is characterized in that based on fluorescent material raising light conversion efficiency:

Described excitation source (1) is the area source structure.

7. according to the described light-source structure of claim 1, it is characterized in that based on fluorescent material raising light conversion efficiency:

Also comprise the heat conduction speculum, be excited between material (3) and the thermal conductive substrate (4) between described.

8. according to the described light-source structure of claim 7, it is characterized in that based on fluorescent material raising light conversion efficiency:

Described heat conduction speculum is the polished surface of described thermal conductive substrate (4), or is the plated film based on described thermal conductive substrate (4); The described material (3) of being excited applies or covers on this heat conduction speculum.

9. according to each described light-source structure of claim 1～5, it is characterized in that based on fluorescent material raising light conversion efficiency:

Also comprise transparent light guide medium (6), be arranged on the one or both sides of described beam split optical filter (2).

10. according to the described light source of claim 9, it is characterized in that structure based on fluorescent material raising light conversion efficiency:

Described transparent light guide medium (6) is the triangular glass column, is close to described beam split optical filter (2) with a side.

11., it is characterized in that structure according to the described light source of claim 1 based on fluorescent material raising light conversion efficiency:

Also comprise rotating disk (5), described thermal conductive substrate (4) is fixed on this rotating disk (5) or is the some of this rotating disk card.

12., it is characterized in that according to the described light-source structure of claim 11 based on fluorescent material raising light conversion efficiency:

The rotating shaft (52) that described thermal conductive substrate (4) goes up with described rotating disk (5) be the center, is excited material (31,32) along at least two kinds of circumference subregion distributions.

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