TWI545807B - White light emitting device - Google Patents

Description

White light emitting device

The present invention relates to a light-emitting device, and more particularly to a white light-emitting device having high color rendering properties.

The higher the color rendering of the light source for general illumination, the more realistic the color of the illuminated object, and vice versa, the lower the color rendering, the more the color of the illuminated object will be distorted.

Conventionally, a light source that emits light using a semiconductor wafer, such as an LED light source, has a color temperature of 5000 K or less, and generally the color rendering performance cannot reach the average color rendering evaluation Ra and the special color rendering evaluation numbers R9 to R15 are greater than 90, especially R9 and R12. The value of one cannot be greater than 90.

Since the LED light source has the advantages of energy saving, environmental protection, long service life, etc., how to achieve higher color rendering to expand the application field of the LED light source is a problem to be solved.

Therefore, an object of the present invention is to provide a white light-emitting device having a color temperature of 5000 K or less, an average color rendering evaluation value Ra, and a special color rendering evaluation number R9 to R15 of more than 90.

Thus, the white light emitting device of the present invention comprises a light emitting chip and a phosphor layer. The luminescent wafer emits light having a peak wavelength between 390 and 430 nm. The phosphor layer includes a first phosphor material, a second phosphor material, and a third phosphor material. The first phosphor material can be excited to emit light having a peak wavelength between 450 and 470 nm. The second fluorescent material can be excited to emit light having a peak wavelength of 520 to 530 nm, and the ratio of the luminous intensity I _G (490 nm) at a wavelength of 490 nm to the luminous intensity I _G (Wp) of the peak wavelength is not less than 0.3, that is, I _G (490 nm) / I _G (Wp) ≧ 0.3. The third fluorescent material can be excited to emit light having a peak wavelength of 630 to 650 nm, and the ratio of the luminous intensity I _R (580 nm) at a wavelength of 580 nm to the luminous intensity I _R (Wp) of the peak wavelength is not less than 0.3, that is, I _R (580 nm) / I _R (Wp) ≧ 0.3. Therefore, the color temperature of the overall mixed light formed by the white light emitting device is 5000 K or less, and the values of the average color rendering evaluation Ra and the special color rendering evaluation numbers R9 to R15 are both greater than 90.

The effect of the present invention is that the near-ultraviolet (near-UV) wafer is matched with a fluorescent material having a specific emission wavelength and spectrum, and the color temperature of the overall mixed light is below 5000K and the color rendering property reaches the average color rendering number Ra and The values of the special color rendering numbers R9 to R15 are all greater than the color rendering of 90.

1‧‧‧Base

11‧‧‧ lead frame

111‧‧‧Installation slot

12‧‧‧Front frame

121‧‧‧ accommodating space

13‧‧‧ accommodating space

2‧‧‧Lighting chip

3‧‧‧Fluorescent layer

4‧‧‧Metal wire

Other features and effects of the present invention will be apparent from the embodiments of the present invention, wherein: FIG. 1 is a perspective view illustrating a first embodiment of the white light emitting device of the present invention; FIG. 2 is a top view illustrating the First embodiment; FIG. 3 is a spectrogram illustrating the luminescence spectrum of the first, second, and third phosphor materials in the first embodiment; 4 is a spectrum diagram illustrating the overall mixed light spectrum of the first embodiment; FIG. 5 is a spectrum diagram of a reference light source having a color temperature of 5000 K; FIG. 6 is a spectrum diagram of the overall mixed light of the second embodiment of the white light emitting device of the present invention. Fig. 7 is a spectrum diagram of a reference light source having a color temperature of 2700 K; and Fig. 8 is a perspective view showing a third embodiment of the white light emitting device of the present invention.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same reference numerals.

Referring to FIG. 1 and FIG. 2, a first embodiment of the white light emitting device of the present invention comprises a susceptor 1, an illuminating wafer 2 and a phosphor layer 3.

The pedestal 1 has a lead frame 11 and an outer frame 12 coupled to the lead frame 11. The two define an accommodating space 121 for accommodating the illuminating wafer 2 disposed on the lead frame 11. And the metal wire 4 is electrically connected to the lead frame 11. In this embodiment, the illuminating wafer 2 is a near-UV wafer, and emits a first ray having a peak wavelength of 390 to 430 nm, and specifically has a peak wavelength (Wp) of 407 nm.

The phosphor layer 3 is filled in the accommodating space 121 and covers the illuminating wafer 2, and includes a colloid, a first fluorescent material, a second fluorescent material and a third fluorescent material, and the first and the first 2. The third fluorescent material is located in the gel body. The first fluorescent material is excited by a first excitation light source, such as the first light generated by the light-emitting chip 2, to emit a second light having a peak wavelength of 450 to 470 nm; and the second fluorescent material is subjected to a second excitation light. The source, for example, the first light and the second light, the generated light is excited to emit a third light having a peak wavelength of 520 to 530 nm; and the third fluorescent material is subjected to a third excitation light source, for example, the first light, The second light and the third light, the generated light is excited to emit light having a peak wavelength between 630 and 650 nm. In particular, the first phosphor material can be excited to produce blue light, the second phosphor material can be excited to produce green light, and the third phosphor material can be excited to produce red light.

In addition, the lead frame 11 further has a mounting slot 111. The illuminating chip 2 is located in the mounting slot 111 and communicates with the accommodating space 121. In other words, the accommodating space 121 also includes the mounting slot 111. Therefore, the phosphor layer 3 is also filled in the mounting groove 111 and the accommodating space 121 or filled in the accommodating space 121 including the mounting groove 111.

The emission spectrum (Emission) of the fluorescent material used in this embodiment is shown in FIG. Since the color of the special color evaluation number R12 is a strong blue color, in order to effectively increase R12, the first fluorescent material, that is, the blue fluorescent powder, is added, and the full width at half maximum (FWHM) of the spectrum is also much larger than that. Generally, the blue chip is wide. Moreover, since the wavelength of the emitted light of the first fluorescent material is mainly distributed in the interval of 432-492 nm, extending downward to 410 nm, extending upward to 550 nm, and further to 600 nm, excitation light of 430 nm or less should be used, so The aforementioned light-emitting wafer 2 employs a near-UV wafer. It should be noted that the ratio of the luminous intensity I _G (490 nm) of the second fluorescent material used in the embodiment to the luminous intensity I _G (Wp) of the peak wavelength is not less than 0.3, that is, I _G (490 nm). /I _G (Wp) ≧ 0.3, thereby reinforcing the portion of the first fluorescent material that is weak in intensity near the 490 nm band, so that R12 can reach 90 or more. In addition, the wavelength of the emitted light of the second fluorescent material is mainly distributed in the interval of 503-563 nm, extends downward to 460 nm, and extends upward to 640 nm, and further to 700 nm. Furthermore, the wavelength of the emitted light of the third fluorescent material used in this embodiment is mainly distributed in the range of 600-700 nm, extending downward to 500 nm, extending upward to 750 nm, and further to 800 nm, full width at half maximum (FWHM). More than 100 nm, and the ratio of the luminous intensity I _R (580 nm) at a wavelength of 580 nm to the luminous intensity I _R (Wp) of the peak wavelength is not less than 0.3, that is, I _R (580 nm) / I _R (Wp) ≧ 0.3, to increase the number The overlapping area between the emission spectrum of the two fluorescent materials and the emission spectrum of the third fluorescent material reduces the difference between the peaks of the two spectra, thereby forming a relatively continuous and flat spectrum, enabling the average color rendering number Ra And the value of the special color evaluation number R9 to R15 is greater than 90, improving the overall color rendering.

The light-mixing spectrum of the luminescent wafer 2 and the fluorescent material as a whole is shown in FIG. In the present embodiment, the spectral luminous intensity values of the plurality of samples are as shown in Table 1, wherein I _C (Wp) represents the peak wavelength luminous intensity of the light-emitting wafer 2, and I _B (Wp) represents the first fluorescent light. The peak wavelength luminescence intensity of the material, I _G (Wp) represents the peak wavelength luminescence intensity of the second luminescent material, and I _R (Wp) represents the peak wavelength luminescence intensity of the third luminescent material, and I _B (Wp) The value is the ratio of I _C (Wp): I _B (Wp): I _G (Wp): I _R (Wp). The ratios A, B, C, D, and E listed in the table are different samples. The measured value, the estimated ratio range is I _C (Wp): I _B (Wp): I _G (Wp): I _R (Wp) is about 3.4-5.2:1:1-1.6:1-1.5.

Taking the color temperature of the overall mixed light of 4875K as an example, the values of the average color rendering evaluation Ra and the special color rendering evaluation numbers R9 to R15 are all greater than 90, and the detailed numerical values are shown in Table 2.

Referring to FIG. 5, FIG. 5 is a spectrum diagram of a reference light source with a color temperature close to 5000K. Comparing FIG. 4 with FIG. 5, it can be seen that the wavelength is 450-470 nm as the first region, 470-520 nm is the second region, and 520-530 nm is the third region. 530-580nm is the fourth region, and 580-630nm is the Vth region. In this embodiment, the waveform of the overall mixed light spectrum in each interval is substantially the same as the waveform distribution trend of the reference light source in the corresponding interval. Further, in the present embodiment, the spectrum of the overall mixed light formed by the white light-emitting device is preferably distributed in a continuous and nearly flat waveform in the III, IV, and V regions.

That is to say, when selecting the three kinds of phosphor powders to be used in the embodiment, the waveform distribution of the spectrum of the reference light source can be matched, and the overall mixed light spectrum constructed by the three kinds of phosphor powders and the spectrum waveform of the reference light source. The distribution trend is roughly the same. However, it is worth noting that the overall mixing spectrum of the phosphor powder is completely consistent with the spectrum of the reference source, so it is difficult to achieve a better color rendering number (Ra, R9-R15). The waveform distribution trend of at least two sections in the interval is substantially consistent; further, if the foregoing zones I and II are defined as the first group, the aforementioned zones III, IV, and V are defined as the second group, The overall mixed light spectrum of the phosphor powder has a waveform distribution tendency of at least one region in the first group and the second group to be substantially the same as a waveform distribution trend in a corresponding interval of the reference light source spectrum.

In this embodiment, the first fluorescent material is blue fluorescent powder, and the aluminate fluorescent powder is preferably used, such as BAM fluorescent powder, specifically using a fluorescent powder of BaMgAl10O17:Eu. The second fluorescent material is a green fluorescent powder, and a silicic fluorescent powder is preferably used, specifically a fluorescent powder of the formula (Ba, Sr, Ca) 2 SiO 4 :Eu. The third fluorescent material is a red fluorescent powder, preferably a Nitrix-activated nitride (Nitride) and an oxynitride (Oxynitride) phosphor, such as CASN, SCASN or CASON phosphor, specifically The chemical formula is a CaAlSi(ON)3:Eu phosphor.

Wherein, in the white light emitting device exemplified in FIG. 1 , the mixing ratio of the first fluorescent material, the second fluorescent material and the third fluorescent material is 8:1:2, and the fluorescent materials are combined. The ratio to the colloid was 20.5 wt% in terms of weight percent.

Referring to FIG. 6 and FIG. 7, the second embodiment of the white light emitting device of the present invention The embodiment is substantially the same as the structure of the first embodiment. However, in the embodiment, the first phosphor material, the second phosphor material and the third phosphor material are mixed to form a color temperature of 2733 K for overall mixed light. FIG. 6 is a spectrum diagram of the overall mixed light of the second embodiment, and FIG. 7 is a spectrum diagram of a reference light source with a color temperature of 2700 K. Comparing FIG. 6 with FIG. 7 , the wavelength of 450-470 nm is the first region, 470-520 nm. For the second region, 520-530nm is the third region, 530-580nm is the fourth region, and 580-630nm is the V region. In this embodiment, the spectrum of the overall mixed light is distributed in each local interval and the spectrum of the reference light source is The corresponding local interval waveform distribution trends are approximately the same. Similarly, the values of the average color rendering evaluation Ra and the special color rendering evaluation numbers R9 to R15 of the present embodiment are all greater than 90, and the detailed numerical values are shown in Table 3.

Referring to FIG. 8, a third embodiment of the white light emitting device of the present invention comprises a lead frame 11 and a base 1 coupled to the outer frame 12 of the lead frame 11. The outer frame 12 and the lead frame 11 define an accommodation. A luminescent substrate 2 is disposed in the accommodating space 13 and a phosphor layer 3 is filled in the accommodating space 13 and covers the luminescent wafer 2. However, in this embodiment, the susceptor 1 is substantially square, and the accommodating space 13 is substantially circular. Furthermore, the total amount of the phosphor materials of the phosphor layer 3 The ratio of the colloid to the colloid is from 50 to 70% by weight. The same color rendering as in the first embodiment can also be achieved. The ratio of the sum of the phosphor materials of the phosphor layer 3 to the colloid can be roughly represented by different package patterns by the following mathematical expression: y=-20.11ln(x)+43.067, where x represents the fluorescence The total volume of the body layer 3, y represents the weight percentage of the total of the phosphor materials.

In addition to the foregoing embodiments, the phosphor layer may also contain only the phosphor materials and be formed directly on the surface of the wafer, or formed on the outer surface of the outer surface of the encapsulant or the outer surface of the outer optical structure to form a remote phosphor layer (Remote). The type of phosphor).

In summary, the present invention allows a near-ultraviolet (near-UV) wafer to be combined with three kinds of phosphor materials having specific emission wavelengths and spectra, so that the color temperature of the overall mixed light is below 5000K and the color rendering performance reaches the average color rendering number. The values of Ra and the special color rendering number R9 to R15 are both greater than the color rendering property of 90, so that the object of the present invention can be achieved.

However, the above is only the embodiment of the present invention, and the scope of the present invention is not limited thereto, that is, the simple equivalent changes and modifications made by the patent application scope and the patent specification of the present invention are still It is within the scope of the patent of the present invention.

Claims (13)

A white light emitting device comprising: an illuminating wafer emitting light having a wavelength of 390 to 430 nm; and a phosphor layer comprising a first fluorescent material capable of exciting light having a peak wavelength of 450 to 470 nm, a second fluorescent material capable of being excited to emit light having a peak wavelength of 520 to 530 nm, and a ratio of an emission intensity I _G (490 nm) at a wavelength of 490 nm to an emission intensity I _G (Wp) of a peak wavelength is not less than 0.3, That is, I _G (490 nm) / I _G (Wp) ≧ 0.3, and a third fluorescent material, can be excited to emit light having a peak wavelength of 630 to 650 nm, and the luminous intensity I _R (580 nm) at a wavelength of 580 nm and The ratio of the luminous intensity I _R (Wp) of the peak wavelength is not less than 0.3, that is, I _R (580 nm) / I _R (Wp) ≧ 0.3; the color temperature of the overall mixed light formed by the white light emitting device is 5000 K or less and the average color rendering number is The values of Ra and special color evaluation numbers R9 to R15 are both greater than 90. The white light emitting device according to a request item 1, wherein the intensity peak wavelength of emission of the light emitting chip I _C (Wp), the peak wavelength of emission intensity of the first fluorescent material I _B (Wp), the second fluorescent material The ratio of the peak wavelength luminous intensity I _G (Wp) to the peak wavelength luminous intensity I _R (Wp) of the third fluorescent material is: I _C (Wp): I _B (Wp): I _G (Wp): I _R (Wp) = 3.4 - 5.2: 1:1 - 1.6: 1-1.5. The white light emitting device of claim 1, wherein the third phosphor material emits a full width at half maximum (FWHM) of greater than 100 nm. The white light emitting device of claim 1, wherein the first fluorescent material is yttrium aluminate phosphor, the second fluorescent material is bismuth silicate powder, and the third fluorescent material is contained An active nitride phosphor or oxynitride phosphor. The white light emitting device of any one of claims 1 to 4, further comprising a base, the base having a lead frame and an outer frame coupled to the lead frame, the outer frame being common with the lead frame An illuminating chip is disposed on the lead frame and located in the accommodating space. The phosphor layer further includes a colloid and is filled in the accommodating space and covers the illuminating wafer. The white light emitting device of claim 5, wherein the ratio of the sum of the phosphor materials of the phosphor layer to the colloid is represented by the following mathematical formula: y=-20.11ln(x)+43.067, where x represents The total volume of the phosphor layer, y represents the weight percent of the total of the phosphor materials. A white light emitting device comprising: an illuminating wafer emitting light having a wavelength of 390 to 430 nm; and a phosphor layer comprising a first fluorescent material capable of exciting light having a peak wavelength of 450 to 470 nm, a second phosphor material that is excited to emit light having a peak wavelength between 520 and 530 nm, and a third phosphor material that is excited to have a peak wavelength between Light of 630 to 650 nm; the first region with a wavelength of 450-470 nm, the second region with 470-520 nm, the third region with 520-530 nm, the fourth region with 530-580 nm, and the V region with 580-630 nm, the white light The spectrum of the overall mixed light formed by the illuminating device has the same waveform distribution tendency of at least two regions in the aforementioned wavelength interval and the spectrum of the reference light source corresponding to the color temperature in the corresponding interval, so that the color temperature is below 5000K and the average color rendering number is The values of Ra and special color evaluation numbers R9 to R15 are both greater than 90. The white light emitting device according to claim 7, wherein the first and second regions are defined as a first group, and the third, fourth, and fourth regions are defined as a second group, and the white light emitting device is formed as a whole. The waveform of the mixed light spectrum in at least one of the first and second groups has the same waveform distribution tendency as the reference light source spectrum in the corresponding interval. A white light emitting device comprising: a light emitting chip emitting light having a wavelength of 390 to 430 nm; and a phosphor layer comprising a blue phosphor, a chemical formula of BaMgAl ₁₀ O ₁₇ :Eu, and a red fluorescent The powder has a chemical formula of CaAlSi(ON) ₃ :Eu; the color temperature of the overall mixed light formed by the white light emitting device is 5000 K or less, and the values of the average color rendering evaluation Ra and the special color rendering evaluation numbers R9 to R15 are both greater than 90. The white light emitting device of claim 9, wherein the phosphor layer further comprises a green phosphor having a chemical formula of (Ba, Sr, Ca) ₂ SiO ₄ :Eu. The white light emitting device of claim 10, wherein the mixing ratio of the blue phosphor powder, the green phosphor powder and the red phosphor powder is 8:1:2. The white light emitting device of any one of claims 9 to 11, further comprising a pedestal, the pedestal having a lead frame and an outer frame combined with the lead frame, the outer frame being common with the lead frame An illuminating chip is disposed on the lead frame and located in the accommodating space. The phosphor layer further includes a colloid and is filled in the accommodating space and covers the illuminating wafer. The white light emitting device of claim 12, wherein the ratio of the sum of the phosphor materials of the phosphor layer to the colloid is represented by the following mathematical expression: y=-20.11ln(x)+43.067, where x represents The total volume of the phosphor layer, y represents the weight percent of the total of the phosphor materials.