White light emitting diode
Technical field
The present invention relates to a kind of light-emitting component, particularly relate to a kind of photochromic otherness that can improve forward and side direction white light, effectively solve the white light emitting diode of photochromic inconsistent problem.
Background technology
Light-emitting diode has advantages such as volume is little, in light weight, reaction speed is fast, can be widely as the light source of various indicating devices and display.Develop the white light emitting diode that in recent years, also can replace general osram lamp or fluorescent tube as lighting source.
The known white light emitting diode that has various ways, wherein a kind of common white light emitting diode, see also shown in Figure 1, it is the schematic diagram of existing white light emitting diode in the past, its be with a fluorescence coating 13 that contains fluorescent powder be covered in a blue light emitting crystal grain 12 around, borrow fluorescent powder absorption a part of blue light that luminescent grain 12 sends and this part blue light is converted to gold-tinted, and form white light with the unabsorbed blue light colour mixture of another part.Because this kind mode only need be stablized the luminescent grain of a kind of coloured light of control, so drive circuit is simple relatively and with low cost.
Yet, consider the photochromic uniformity of this kind white light emitting diode on all directions, generally need consider following two factors: one, blue light emitting crystal grain 12 itself has the characteristic of forward luminous intensity greater than lateral direction light emission intensity, that is to say the blue light light quantity that the blue light light quantity that luminescent grain 12 forwards send can be sent more than side direction; They are two years old, fluorescence coating 13 is at the thickness of the luminescent grain 12 side direction thickness greater than forward, make luminescent grain 12 lateral light LS than forward light LN through the path of fluorescence coating 13 for long so that the lateral light LS of luminescent grain 12 to meet fluorescent powder quantity fluorescence coating 13 in more and gold-tinted light quantity that change is more.Therefore, generally speaking, this kind white light emitting diode can have forward bias indigo plant and the yellow partially photochromic difference phenomenon of side direction.
Seeing also shown in Figure 2ly, is the chromaticity coordinates figure of existing white light emitting diode in the past.Color standard according to Commission Internationale De L'Eclairage (CIE), and be 0 degree with the forward of light-emitting diode, as can be seen the photochromic chromaticity coordinates value of light-emitting diode (x, y) different really with side direction (90 degree), and its difference is to be continuous variation along with angle at forward (0 degree).
And the photochromic differential seat angle opposite sex of this kind, use under high-power trend at current white light emitting diode, the luminous intensity difference of luminescent grain 12 forwards own and side direction can be bigger, luminescent grain 12 and the increase of pedestal 11 sizes cause the path length difference of forward light and lateral light process fluorescence coating 13 also bigger, make that all the beneficial shape of the above-mentioned photochromic differential seat angle opposite sex is serious.
This shows that above-mentioned existing white light emitting diode obviously still has inconvenience and defective, and demands urgently further being improved in structure and use.For solving the problem of above-mentioned existence, relevant manufacturer there's no one who doesn't or isn't seeks solution painstakingly, but do not see always that for a long time suitable design finished by development, and common product does not have appropriate structure to address the above problem, this obviously is the problem that the anxious desire of relevant dealer solves.Therefore how to found a kind of white light emitting diode of new structure, real one of the current important research and development problem that belongs to, also becoming the current industry utmost point needs improved target.
Because the defective that above-mentioned existing white light emitting diode exists, the inventor is based on being engaged in this type of product design manufacturing abundant for many years practical experience and professional knowledge, and the utilization of cooperation scientific principle, actively studied innovation, in the hope of founding a kind of white light emitting diode of new structure, can improve general existing white light emitting diode, make it have more practicality.Through constantly research, design, and, create the present invention who has practical value finally through after studying sample and improvement repeatedly.
Summary of the invention
The objective of the invention is to, overcome the defective that existing white light emitting diode exists, and a kind of white light emitting diode that can solve photochromic inconsistent problem is provided, be very suitable for practicality.
The object of the invention to solve the technical problems realizes by the following technical solutions.A kind of white light emitting diode according to the present invention's proposition, comprise a pedestal, and be located at luminescent grain on the described pedestal, and one be located on the described pedestal and cover first fluorescence coating of described luminescent grain, wherein: described white light emitting diode also comprises one second fluorescence coating, is located on the end face of described first fluorescence coating; And the top surface area of described second fluorescence coating is greater than the top surface area of described luminescent grain and less than the top surface area of described first fluorescence coating, and described luminescent grain is positioned at the orthographic projection scope of described second fluorescence coating below; The top surface area of wherein said second fluorescence coating is 1 to 4 times of top surface area of described luminescent grain, and the top surface area of described first fluorescence coating is 3 times of top surface area of described second fluorescence coating.
The object of the invention to solve the technical problems also can be applied to the following technical measures to achieve further.
Aforesaid white light emitting diode, wherein said pedestal also form and are provided with a storage tank, and described luminescent grain is located at the bottom of described storage tank, and described first fluorescence coating is located in the described storage tank and is covered described luminescent grain.
Aforesaid white light emitting diode, wherein said luminescent grain sends blue light or ultraviolet light.
Aforesaid white light emitting diode, wherein said second fluorescence coating is thicker in the thin gradually shape of periphery for central authorities.
Aforesaid white light emitting diode, the contained fluorescent powder concentration of wherein said second fluorescence coating differs from the contained fluorescent powder concentration of described first fluorescence coating.
Aforesaid white light emitting diode, the contained fluorescent powder concentration ratio of wherein said second fluorescence coating and described first fluorescence coating is 1.1: 1.
Aforesaid white light emitting diode, wherein said white light emitting diode also comprise the protective layer of described first fluorescence coating of covering and second fluorescence coating.
Aforesaid white light emitting diode, wherein said protective layer comprise a most scattering particles.
Aforesaid white light emitting diode, the material of wherein said scattering particles are one of them of silica, aluminium oxide, calcium oxide or titanium oxide.
The present invention compared with prior art has tangible advantage and beneficial effect.As known from the above, in order to achieve the above object, consider forward of luminescent grain own and lateral direction light emission strength difference, and the forward that is sent and lateral light are through the path length difference of fluorescence coating, the present invention is on first fluorescence coating that covers luminescent grain, position corresponding to luminescent grain, form second fluorescence coating of a top surface area less than the top surface area of first fluorescence coating, in order to increase luminescent grain forward light through the total path length of fluorescence coating, providing more is the fluorescent powder of gold-tinted in order to converting blue light, so as to improving the photochromic differential seat angle opposite sex.
In the preferred embodiment of the present invention, the top surface area of first fluorescence coating is 3 times of top surface area of second fluorescence coating.
In the preferred embodiment of the present invention, the top surface area of second fluorescence coating is 1 to 4 times of top surface area of luminescent grain.
In the preferred embodiment of the present invention, second fluorescence coating is thicker in the thin gradually shape of periphery for central authorities.
In the preferred embodiment of the present invention, the contained fluorescent powder concentration of second fluorescence coating differs from the contained fluorescent powder concentration of first fluorescence coating.
So white light emitting diode of the present invention comprises a pedestal; One is located at the luminescent grain on the pedestal; One is located on the pedestal and covers first fluorescence coating of luminescent grain; And second fluorescence coating of being located on first fluorescence coating, the top surface area of second fluorescence coating is greater than the top surface area of luminescent grain and less than the top surface area of first fluorescence coating, and luminescent grain is positioned at the orthographic projection scope of second fluorescence coating below.
The present invention forms second fluorescence coating of a top surface area less than the top surface area of first fluorescence coating on first fluorescence coating, so as to improving the photochromic otherness of white light emitting diode.
By technique scheme, white light emitting diode of the present invention has following advantage and beneficial effect at least: the present invention is on first fluorescence coating that covers luminescent grain, naturally drip to cover in a glue mode and form second fluorescence coating of a top surface area less than the top surface area of first fluorescence coating, and make luminescent grain be positioned at the orthographic projection scope of second fluorescence coating below, can increase the path of the fluorescence coating of luminescent grain forward light institute warp, more fluorescent powder is provided on the path of forward light, by the fluorescent powder converting blue light is gold-tinted, reduce blue light light quantity forward on the one hand, increase gold-tinted light quantity forward on the other hand simultaneously, no matter make blue light or the light quantity of gold-tinted all can reach consistent haply in forward and side direction, and can improve the photochromic otherness of the white light of forward and side direction.
In sum, the present invention can effectively solve photochromic inconsistent problem, is very suitable for practicality.The present invention has above-mentioned plurality of advantages and practical value, no matter it all has bigger improvement on product structure or function, obvious improvement is arranged technically, and produced handy and practical effect, and more existing white light emitting diode has the outstanding effect of enhancement, thereby being suitable for practicality more, and having the extensive value of industry, really is a new and innovative, progressive, practical new design.
Above-mentioned explanation only is the general introduction of technical solution of the present invention, for can clearer understanding technological means of the present invention, and can be implemented according to the content of specification, and for above-mentioned and other purposes, feature and advantage of the present invention can be become apparent, below especially exemplified by preferred embodiment, and conjunction with figs., be described in detail as follows.
Description of drawings
Fig. 1 is the schematic diagram of existing white light emitting diode in the past.
Fig. 2 is the chromaticity coordinates figure of existing white light emitting diode in the past.
Fig. 3 is the schematic side view of white light emitting diode preferred embodiment of the present invention.
Fig. 4 is the schematic top plan view of white light emitting diode preferred embodiment of the present invention.
Fig. 5 is the chromaticity coordinates figure of white light emitting diode preferred embodiment of the present invention.
Embodiment
Reach technological means and the effect that predetermined goal of the invention is taked for further setting forth the present invention, below in conjunction with accompanying drawing and preferred embodiment, to its embodiment of white light emitting diode, structure, feature and the effect thereof that foundation the present invention proposes, describe in detail as after.
Seeing also shown in Figure 3ly, is the schematic side view of white light emitting diode preferred embodiment of the present invention.The preferred embodiment of white light emitting diode of the present invention, it comprises a pedestal 21, a luminescent grain 22, one first fluorescence coating 23, one second fluorescence coating 24, and a protective layer 25.
Above-mentioned pedestal 21 have a body that is formed with a cup-shaped storage tank 211, and at least one pair of is extended through the metal electrode (not shown) in the storage tank 211.
Above-mentioned luminescent grain 22 is located at the bottom of storage tank 211, and engages (wirebonding) or chip bonding (flip chip bonding) mode with routing and be electrically connected with metal electrode, emits beam with driven for emitting lights crystal grain 22 so as to the connection external power source.Luminescent grain 22 is in order to send blue light, and its wavelength is between 400nm~470nm.
The first above-mentioned fluorescence coating 23 is located in the storage tank 211 and is covered luminescent grain 22.It comprises transparent colloid and is doped in the interior majority fluorescent powder of transparent colloid, wherein, this transparent colloid can adopt materials such as silica gel or epoxy resin, and this fluorescent powder can adopt convertible blue light and send the material of wavelength between 520nm~570nm gold-tinted, the making of first fluorescence coating 23 can utilize has the knack of that this technical field technical staff uses always, and mode is carried out for example to put glue and solidified etc.Perhaps, this fluorescent powder also can adopt and comprise convertible blue light and send wavelength between 590nm~650nm ruddiness, and convertible blue light and send the fluorescent powder mixture of wavelength between 500nm~530nm green glow.
Path for the fluorescence coating that increases luminescent grain 22 forward light institute warps, the present invention forms one second fluorescence coating 24 on the end face of first fluorescence coating 23, and making luminescent grain 22 be positioned at the orthographic projection scope of second fluorescence coating, 24 belows, is the fluorescent powder of gold-tinted so that the more blue light that sends in order to conversion luminescence crystal grain 22 to be provided on the path of forward light; Its material is same as first fluorescence coating 23.
Seeing also Fig. 3 and shown in Figure 4, is the schematic side view and the schematic top plan view of white light emitting diode preferred embodiment of the present invention.The second above-mentioned fluorescence coating 24, its top surface area is greater than the top surface area of luminescent grain 22 and less than the top surface area of first fluorescence coating 23.When reality was implemented, the top surface area of first fluorescence coating 23 was 1 to 4 times of second fluorescence coating 24, was good with 3 times especially wherein; And the top surface area of second fluorescence coating 24 is that 3 times of top surface area of luminescent grain 22 are for good.
In addition, except the above-mentioned fluorescence coating that can send gold-tinted with blue light emitting crystal grain collocation forms the white light with colour mixture, can also adopt and to send the UV-light luminous crystal grain of wavelength between 300nm~400nm, the collocation comprise can send wavelength between 590nm~650nm ruddiness, can send wavelength between 500nm~530nm green glow, and can send the fluorescent powder mixture of wavelength between 440nm~480nm blue light, also color-mixing forms white light.
And, because the photochromic otherness that institute's desire is improved is to be continuous variation, therefore, as shown in Figure 3, present embodiment is to take to make second fluorescence coating 24 in a glue mode, the liquid fluorescent material that will comprise transparent colloid and fluorescent powder drips naturally and is overlying on first fluorescence coating 23, because the surface tension effects of liquid fluorescent material, it is thicker and towards the thin gradually shape of periphery to make that second fluorescence coating 24 can form central authorities haply.
And,, make second fluorescence coating 24 be firmly fixed at dripping on first fluorescence coating 23 and cover the position and be not easy change because of the cohesive force effect because second fluorescence coating 24 adopts the transparent colloid identical with first fluorescence coating 23.
Moreover, because the surface tension effects of second fluorescence coating 24, its thickness can become a particular kind of relationship with its area, and under the condition that area is fixed, its thickness is not easy to reach the ideal value that makes photochromic uniformity the best usually, therefore the present invention also adjusts the fluorescent powder concentration of second fluorescence coating 24, makes the photochromic uniformity of forward and side direction better.The fluorescent powder concentration ratio of second fluorescence coating 24 and first fluorescence coating 23 is 1.1: 1 in the present embodiment.
Above-mentioned protective layer 25 covers first fluorescence coating 23 and second fluorescence coating 24, in order to isolated first fluorescence coating 23 and second fluorescence coating 24, prevents air contact generation oxidation and go bad that its material is a silica gel.And protective layer 25 also can comprise most the scattering particless that are scattered in the silica gel, so as to the blue light that luminescent grain 22 is sent, and the gold-tinted that sent of first fluorescence coating 23 and second fluorescence coating 24, and further scattering and mixing in protective layer 25.Wherein, scattering particles is inorganic compound material such as silica, aluminium oxide, calcium oxide, titanium oxide etc.
In addition, the mould of also can arranging in pairs or groups is made as lens shape with protective layer 25, to take in the effect of protection and optically focused concurrently.
Seeing also shown in Figure 5ly, is the chromaticity coordinates figure of white light emitting diode preferred embodiment of the present invention.After measuring, color standard according to Commission Internationale De L'Eclairage (CIE), forward with light-emitting diode is 0 degree, the photochromic chromaticity coordinates value (x of light-emitting diode as can be seen, y) be to be certain value haply, do not change along with angle and difference to some extent, meaning is that the photochromic difference of the forward of white light emitting diode of this preferred embodiment and side direction is minimum, and more existing really white light emitting diode is good.
Conclude above-mentioned, the present invention is on first fluorescence coating that covers luminescent grain, naturally drip to cover in a glue mode and form second fluorescence coating of a top surface area less than the top surface area of first fluorescence coating, and make luminescent grain be positioned at the orthographic projection scope of second fluorescence coating below, can increase the path of the fluorescence coating of luminescent grain forward light institute warp, more fluorescent powder is provided on the path of forward light, by the fluorescent powder converting blue light is gold-tinted, reduce blue light light quantity forward on the one hand, increase gold-tinted light quantity forward on the other hand simultaneously, no matter make blue light or the light quantity of gold-tinted reaches consistent haply in forward and side direction, and can improve the photochromic otherness of the white light of forward and side direction, reach effect of the present invention really.
The above, it only is preferred embodiment of the present invention, be not that the present invention is done any pro forma restriction, though the present invention discloses as above with preferred embodiment, yet be not in order to limit the present invention, any those skilled in the art, in not breaking away from the technical solution of the present invention scope, when the technology contents that can utilize above-mentioned announcement is made a little change or is modified to the equivalent embodiment of equivalent variations, in every case be the content that does not break away from technical solution of the present invention, according to technical spirit of the present invention to any simple modification that above embodiment did, equivalent variations and modification all still belong in the scope of technical solution of the present invention.