LED white light device, preparation method thereof, and LED backlight module

Abstract

The disclosure provides an LED white light device, including a blue light chip and phosphors. The blue light chip has a band of (455-470) nm. The phosphors include a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (610-660) nm. The yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.2) and cover the blue light chip, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm. The disclosure also provides a preparation method of an LED white light device and an LED backlight module adopting the above LED white light device. The disclosure achieves the effects of blue light prevention, high color gamut and pure white simultaneously, Color uniformity and consistency are good, and a blue-green-red three-color continuous spectrum is provided, which is closer to a solar spectrum.

Claims

1. An LED white light device, comprising a blue light chip and phosphors, wherein the blue light chip has a band of (455-470) nm; the phosphors consist of a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (610-660) nm; and the yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.2) and cover the blue light chip, wherein the yellow phosphor is a lanthanum silicon nitrogen compound, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm, and a ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.2); the yellow phosphor comprises La.sub.3Si.sub.6N.sub.11:Ce.sup.3+ having a peak wavelength of (530-550) nm and (600-620) nm.

2. The LED white light device as claimed in claim 1, wherein white light of the LED white light device has a chromaticity coordinate range of CIE x: 0.22-0.32 and CIE y: 0.20-0.32.

3. The LED white light device as claimed in claim 1, wherein the LED white light device has an NTSC color gamut value that is greater than or equal to 70%.

4. The LED white light device as claimed in claim 1, wherein the red phosphor is a nitride red phosphor or a Mn.sup.4+ doped fluoride red phosphor.

5. The LED white light device as claimed in claim 4, wherein the red phosphor comprises (SrCa)AlSiN.sub.3:Eu having a peak wavelength of (610-660) nm.

6. A preparation method of the LED white light device as claimed in claim 1, comprising: (1) mixing a yellow phosphor and a red phosphor in a proportion, adding the mixture into a packaging glue, stirring uniformly, and then defoaming by vacuuming to obtain a fluorescent glue mixture; and (2) providing the fluorescent glue mixture on an LED support with a blue light chip, and curing to obtain an LED white light device.

7. An LED backlight module, comprising the LED white light device as claimed in claim 1.

8. The preparation method as claimed in claim 6, wherein white light of the LED white light device has a chromaticity coordinate range of CIE x: 0.22-0.32 and CIE y: 0.20-0.32.

9. The preparation method as claimed in claim 6, wherein the LED white light device has an NTSC color gamut value that is greater than or equal to 70%.

10. The preparation method as claimed in claim 6, wherein the yellow phosphor is a lanthanum silicon nitrogen compound.

11. The preparation method as claimed in claim 10, wherein the yellow phosphor comprises La.sub.3Si.sub.6N.sub.11:Ce.sup.3+ having a peak wavelength of (530-550) nm and (600-620) nm.

12. The preparation method as claimed in claim 6, wherein the red phosphor is a nitride red phosphor or a Mn.sup.4+ doped fluoride red phosphor.

13. The preparation method as claimed in claim 12, wherein the red phosphor comprises (SrCa)AlSiN.sub.3:Eu having a peak wavelength of (610-660) nm.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic structural diagram of an LED white light device according to the disclosure;

(2) FIG. 2 is a spectrogram diagram of an LED white light device according to Embodiment 1 of the disclosure;

(3) FIG. 3 is a color gamut diagram of an LED white light device according to Embodiment 1 of the disclosure;

(4) FIG. 4 is a diagram showing a ratio of blue light energy having a wavelength range of (400-450) nm in a spectrum of an LED white light device according to Embodiment 1 of the disclosure;

(5) FIG. 5 is a spectrogram comparison diagram of an LED white light device according to Embodiment 1 of the disclosure with the existing technology;

(6) FIG. 6 is a spectrogram diagram of an LED white light device according to Embodiment 2 of the disclosure;

(7) FIG. 7 is a color gamut diagram of an LED white light device according to Embodiment 2 of the disclosure;

(8) FIG. 8 is a diagram showing a ratio of blue light energy having a wavelength range of (400-450) nm in a spectrum of an LED white light device according to Embodiment 2 of the disclosure;

(9) FIG. 9 is a spectrogram diagram of an LED white light device according to Embodiment 3 of the disclosure;

(10) FIG. 10 is a color gamut diagram of an LED white light device according to Embodiment 3 of the disclosure; and

(11) FIG. 11 is a diagram showing a ratio of blue light energy having a wavelength range of (400-450) nm in a spectrum of an LED white light device according to Embodiment 3 of the disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(12) In order to make the objectives, technical solutions and advantages of the disclosure clearer, the disclosure will be further described herein below.

(13) As shown in FIG. 1, the disclosure provides an LED white light device for preventing blue light pollution applied to a backlight system, including an LED support 1, a blue light chip 2 and phosphors 3, wherein the blue light chip 2 is electrically connected to the LED support 1.

(14) The blue light chip 2 has a band of (455-470) nm. The LED white light device adopts a long-wavelength blue light chip. Due to the change of the chip wavelength, if the conventional phosphor combination is used, the color gamut is narrow, and the emitted light is greenish, which cannot meet the requirements of color gamut and pure white. Therefore, the LED white light device needs to be re-matched with a new phosphor combination, specifically:

(15) The phosphors 3 include a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (610-660) nm. The yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.2) and cover the blue light chip, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm. A ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.2).

(16) Preferably, the phosphors 3 include a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (630-650) nm. The yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.1) and cover the blue light chip, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (455-465) nm. A ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.15).

(17) More preferably, the phosphors 3 include a dual-band yellow phosphor and a red phosphor having an excited light peak wavelength range of (630-650) nm. The yellow phosphor and the red phosphor are mixed according to a proportion of 1:(0.03-0.05) and cover the blue light chip, such that blue light emitted by the packaged LED white light device has a peak wavelength range of (460-465) nm. A ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.1).

(18) The yellow phosphor is, but not limited to, a lanthanum silicon nitrogen compound. Preferably, the yellow phosphor includes La.sub.3SiN.sub.11:Ce.sup.3 having a peak wavelength of (530-550) nm and (600-620) nm. More preferably, the yellow phosphor includes La.sub.3Si.sub.6N.sub.11:Ce.sup.3+ having a peak wavelength of (530-537) nm and (600-620) nm.

(19) The red phosphor is, but not limited to, a nitride red phosphor or a Mn.sup.4+ doped fluoride red phosphor. Preferably, the red phosphor includes (SrCa)AlSiN.sub.3:Eu having a peak wavelength of (610-660) nm.

(20) It is to be noted that the proportion of the yellow phosphor to the red phosphor refers to a mass percentage.

(21) It is also to be noted that the above yellow phosphor and red phosphor include, but are not limited to, the above substances, as long as the respective colors conform to the respective prescribed wavelength ranges.

(22) Further, the LED white light device further includes a packaging glue. It is to be noted that the amount of the packaging glue may also be adjusted according to the performance of the LED white light device.

(23) In summary, the LED white light device uses a blue light chip having a long wavelength of (455-470) nm, and is matched with a redesigned phosphor covering the blue light chip to obtain the LED white light device. In the disclosure, the blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm, and a ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.2), so that the LED white light device can convert more than 95% of harmful blue light into long-wave low-energy light of 450 nm or more, solves the problem that blue light harms the eyes from the perspective of hardware, and reduces the damage caused by high-risk blue light to a user.

(24) In the disclosure, the blue light emitted by the packaged LED white light device has a peak wavelength range of (450-465) nm, and a ratio of energy of a spectrum of the packaged LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:(0.05-0.2), so that the LED white light device can convert more than 95% of harmful blue light into long-wave low-energy light of 450 nm or more, solves the problem that blue light harms the eyes from the perspective of hardware, and reduces the damage caused by high-risk blue light to a user.

(25) Correspondingly, the disclosure provides a preparation method of an LED white light device, which includes the steps as follows.

(26) (1) A yellow phosphor and a red phosphor are mixed in a proportion, added into a packaging glue, stirred uniformly, and then defoamed by vacuuming to obtain a fluorescent glue mixture.

(27) (2) The fluorescent glue mixture is provided on an LED support with a blue light chip, and cured to obtain an LED white light device.

(28) The technical details of the yellow phosphor, the red phosphor and the blue light chip used in the preparation method are the same as those described above, and will not be described herein.

(29) Correspondingly, the disclosure also provides an LED backlight module, which may include the above LED white light device. The technical details of the yellow phosphor, the red phosphor and the blue light chip used in the LED white light device are the same as those described above, and will not be described herein.

(30) The disclosure is further illustrated by the following specific embodiments.

Embodiment 1

(31) (1) A commercially available nitride yellow phosphor (component: La.sub.3S.sub.6N.sub.11:Ce.sup.3+) and a nitride red phosphor (component: (SrCa)AlSiN.sub.3:Eu) are added Into an LED packaging glue in a ratio of 1:0.03. The red and yellow phosphors and the packaging glue are uniformly mixed by stirring, and defoamed by vacuuming to obtain a fluorescent glue mixture.

(32) (2) The fluorescent glue mixture is dropped into an LED support with a blue light chip, and baked in an oven for a certain time to cure the fluorescent glue mixture to obtain an LED white light device for preventing blue light. The blue light chip selected for the LED device has a band of (455-470) nm, and a blue light peak wavelength corresponding to an LED emission spectrum is (450-465) nm.

(33) Spectral testing and color gamut calculation are performed on the LED white light device of Embodiment 1, and the results are shown in FIGS. 2, 3, 4, and 5.

(34) As can be seen from FIGS. 2 and 5 and Table 1, the LED white light device has a blue light band peak wavelength of 460 nm, a green light band peak wavelength of 537 nm, a red light band peak wavelength of 630 nm, and a FWHM (Full Width Half Maximum) of 75 nm. The LED white light device has a blue-green-red three-color continuous spectrum, and is closer to a solar spectrum, the emitted light makes people feel comfortable and natural, and the LED white light device is beneficial to realize healthy illumination.

(35) As can be seen from FIG. 3, the LED white light device may have an NTSC color gamut value that is greater than or equal to 70%, and the color gamut is high.

(36) As can be seen from FIG. 4, a ratio of energy of a spectrum of the LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:0.051, and the content of harmful blue light is low.

(37) White light of the LED white light device has a chromaticity coordinate range of CIE x: 0.22-0.32 and CIE y: 0.20-0.32. The brightness is high, the color performance is natural, and the blue light preventing characteristic is provided, which makes human eyes feel more comfortable.

Embodiment 2

(38) (1) A commercially available nitride yellow phosphor (component: La.sub.3Si.sub.6N.sub.11:Ce.sup.3+) and a nitride red phosphor (component: (SrCa)AlSiN.sub.3:Eu) are added into an LED packaging glue in a ratio of 1:0.04. The red and yellow phosphors and the packaging glue are uniformly mixed by stirring, and defoamed by vacuuming to obtain a fluorescent glue mixture.

(39) (2) The fluorescent glue mixture is dropped into an LED support with a blue light chip, and baked in an oven for a certain time to cure the fluorescent glue mixture to obtain an LED white light device for preventing blue light. The blue light chip selected for the LED device has a band of (455-470) nm, and a blue light peak wavelength corresponding to an LED emission spectrum is (450-465) nm.

(40) Spectral testing and color gamut calculation are performed on the LED white light device of Embodiment 2, and the results are shown in FIGS. 6, 7, and 8.

(41) As can be seen from FIG. 6 and Table 1, the LED white light device has a blue light band peak wavelength of 456 nm, a green light band peak wavelength of 537 nm, a red light band peak wavelength of 630 nm, and a FWHM of 75 nm. The LED white light device has a blue-green-red three-color continuous spectrum, and is closer to a solar spectrum, the emitted light makes people feel comfortable and natural, and the LED white light device is beneficial to realize healthy illumination.

(42) As can be seen from FIG. 7, the LED white light device may have an NTSC color gamut value that is greater than or equal to 70%, and the color gamut is high.

(43) As can be seen from FIG. 8, a ratio of energy of a spectrum of the LED white light device to energy of a blue light spectrum having a wavelength range of (400-450) nm is 1:0.112, and the content of harmful blue light is low.

(44) White light of the LED white light device has a chromaticity coordinate range of CIE x: 0.22-0.32 and CIE y: 0.20-0.32. The brightness is high, the color performance is natural, and the blue light preventing characteristic is provided, which makes human eyes feel more comfortable.

Embodiment 3

(45) (1) A commercially available nitride yellow phosphor (component: La.sub.3Si N.sub.11:Ce.sup.3+) and a nitride red phosphor (component: (SrCa)AlSiN.sub.3:Eu) are added into an LED packaging glue in a ratio of 1:0.2. The red and yellow phosphors and the packaging glue are uniformly mixed by stirring, and defoamed by vacuuming to obtain a fluorescent glue mixture.

(46) (2) The fluorescent glue mixture is dropped into an LED support with a blue light chip, and baked in an oven for a certain time to cure the fluorescent glue mixture to obtain an LED white light device for preventing blue light. The blue light chip selected for the LED device has a band of (455-470) nm, and a blue light peak wavelength corresponding to an LED emission spectrum is (450-465) nm.

(47) Spectral testing and color gamut calculation are performed on the LED white light device of Embodiment 3, and the results are shown in FIGS. 9, 10, and 11.

(48) As can be seen from FIG. 9 and Table 1, the LED white light device has a blue light band peak wavelength of 450 nm, a green light band peak wavelength of 537 nm, a red light band peak wavelength of 630 nm, and a FWHM of 75 nm. The LED white light device has a blue-green-red three-color continuous spectrum, and is closer to a solar spectrum, the emitted light makes people feel comfortable and natural, and the LED white light device is beneficial to realize healthy illumination.

(49) As can be seen from FIG. 10, the LED white light device may have an NTSC color gamut value that is greater than or equal to 70%, and the color gamut is high.

(50) As can be seen from FIG. 11, a ratio of energy of a spectrum of the LED white light device to energy of a blue light spectrum having a wavelength range of 400-450 nm is 1:0.189, and the content of harmful blue light is low.

(51) White light of the LED white light device has a chromaticity coordinate range of CIE x: 0.22-0.32 and CIE y: 0.20-0.32. The brightness is high, the color performance is natural, and the blue light preventing characteristic is provided, which makes human eyes feel more comfortable.

(52) Embodiments 1-3 are compared with the existing technology, as follows:

(53) (1) Existing technology: An yttrium-aluminum garnet phosphor (YAG powder) is excited by a blue light chip to be mixed to produce white light.

(54) (2) Comparison results:

(55) The technical parameters of the disclosure and the existing technology are as shown in Table 1 below.

(56) TABLE-US-00001 (400-450)nm Brightness Color Blue light Chromaticity blue light (relative gamut peak coordinate energy ratio Item value) NTSC wavelength/nm (CIEx, CIEy) in spectrum Embodiment 1 100% 70.8% 460.30 (0.2783, 0.2464) 5.1% Embodiment 2 100% 72.1% 456.31 (0.2786, 0.2467) 11.2% Embodiment 3 100% 73.2% 450.14 (0.2791, 0.2470) 18.9% Existing 100% 68.3% 442.50 (0.2787, 0.2473) 39.7% technology

(57) Combining Table 1 and FIGS. 2-11, the white light device has high brightness, natural color performance and blue light preventing characteristics, can convert more than 95% of harmful blue light into long-wave low-energy light of 450 nm or more, solves the problem that blue light harms the eyes from the perspective of hardware, and reduces the damage caused by high-risk blue light to a user. Moreover, the LED white light device has a blue-green-red three-color continuous spectrum, and is closer to a solar spectrum, the emitted light makes people feel comfortable and natural, and the LED white light device is beneficial to realize healthy illumination.

(58) However, the red light component of the luminescent spectrum in the existing technology is less, the color of an LED display effect is greenish, the color gamut value is 68% NTSC, the color expression is poor, and the blue light preventing effect is not obvious.

(59) The above is a preferred implementation of the disclosure. It is to be noted that a number of modifications and refinements may be made by those of ordinary skill in the art without departing from the principles of the disclosure, and such modifications and refinements are also considered to be within the scope of protection of the disclosure.