Light Emitting Diode Device

Abstract

A light-emitting diode device includes a first green light conversion material, a second green light conversion material, and a red light conversion material distributed on the light output path of a blue light-emitting diode. The first green light conversion material and the second green light conversion material are used to convert the blue light emitted by the blue light-emitting diode and generate a first green light having a first wavelength range and a first wavelength half-width, and a second green light having a second wavelength range and a second wavelength half-width. The second wavelength half-width is smaller than the first wavelength half-width. The lower limit of the first wavelength range is smaller than the lower limit of the second wavelength range, and the upper limit of the second wavelength range is larger than the upper limit of the first wavelength range. The output light emitted by the light-emitting diode device has a spectral characteristic of less than 50% of the German Rhine standard and greater than 90% of the wide color gamut standard. The present invention uses two green light conversion materials to reduce the proportion of light intensity in the blue light band that is harmful to the eyes, while still maintaining the breadth of the color gamut distribution.

Description

Technical Field

[0001] The present disclosure relates to a light emitting diode device having two green light conversion materials therein. Background Art

[0002] The statements herein merely provide background information related to the present disclosure and do not necessarily constitute prior art.

[0003] Liquid crystal display (LCD) and light-emitting diode (LED) display devices have gradually become popular in the past decade, allowing people to enjoy light sources with higher quality and higher energy conversion efficiency. Various improvements to display technology have also sprung up recently. Among the various sub-fields of display technology, the improvement of human eye protection is an important development direction. The light-emitting diodes currently used as light sources are mainly blue light-emitting diodes with a wavelength of about 450 nanometers, which are then converted into white light as display light sources through light conversion materials. However, studies have shown that blue light with a wavelength between about 415 nanometers and about 455 nanometers is more harmful to the eyes and can easily cause various diseases such as macular degeneration. Therefore, in recent years, a low blue light index has been proposed, which helps protect the user's eyes.

[0004] Currently, most products on the market that reduce the blue light in the band that is harmful to the eyes achieve this by reducing the intensity of blue light and using long-wavelength blue light. They mainly use software programs to change the intensity distribution of each wavelength emitted by the display device, or use specially designed filters to filter out blue light to reduce the intensity of blue light received by the human eye. Summary of the invention

[0005] However, although the above method can protect the eyes, it also causes color distortion, which makes the overall display effect felt by the user worse and reduces the user experience.

[0006] In view of this, some embodiments of the present disclosure disclose a light-emitting diode device, including a blue light-emitting diode and a light conversion material. The light conversion material is distributed on the light output path of the blue light-emitting diode. The light conversion material includes a first green light conversion material, a second green light conversion material and a red light conversion material. The first green light conversion material is used to convert the blue light emitted by the blue light-emitting diode and generate a first green light having a first wavelength range and a first wavelength half-width. The second green light conversion material is used to convert the blue light and generate a second green light having a second wavelength range and a second wavelength half-width. The second wavelength half-width is smaller than the first wavelength half-width. The lower limit of the first wavelength range is smaller than the lower limit of the second wavelength range, and the upper limit of the second wavelength range is larger than the upper limit of the first wavelength range. The red light conversion material is used to convert the blue light and generate red light. The output light emitted by the light-emitting diode device has a spectral characteristic of less than 50% of the German Rhine standard and greater than 90% of the wide color gamut standard.

[0007] In one or more embodiments of the present disclosure, the wavelength of blue light ranges from 445 nm to 470 nm.

[0008] In one or more embodiments of the present disclosure, the wavelength of the red light is between 610 nanometers and 660 nanometers.

[0009] In one or more embodiments of the present disclosure, the first wavelength half-width is greater than or equal to 40 nanometers, and the second wavelength half-width is less than 40 nanometers.

[0010] In one or more embodiments of the present disclosure, a union of the first wavelength range and the second wavelength range is between 490 nm and 540 nm.

[0011] In one or more embodiments of the present disclosure, the first wavelength range is between 510 nanometers and 530 nanometers, and the second wavelength range is between 520 nanometers and 540 nanometers. The first wavelength half-width is between 60 nanometers and 100 nanometers, and the second wavelength half-width is between 20 nanometers and 40 nanometers. The emitted light has a spectral characteristic of less than 50% of the German Rhine standard and greater than 95% of the color television broadcast standard established by the National Television System Committee of the United States.

[0012] In one or more embodiments of the present disclosure, the wavelength range of the blue light is between 455 nanometers and 460 nanometers, and the ratio of the first spectrum area of ​​the emitted light in the wavelength range between 415 nanometers and 455 nanometers to the second spectrum area in the wavelength range between 400 nanometers and 500 nanometers is less than 25%. The ratio of the first spectrum area to the third spectrum area in the wavelength range between 380 nanometers and 780 nanometers is less than 30%.

[0013] In one or more embodiments of the present disclosure, the union of the first wavelength range and the second wavelength range is between 500 nanometers and 545 nanometers.

[0014] In one or more embodiments of the present disclosure, the first wavelength range is between 515 nanometers and 540 nanometers, and the second wavelength range is between 525 nanometers and 550 nanometers. The first wavelength half-width is between 60 nanometers and 100 nanometers, and the second wavelength half-width is between 20 nanometers and 40 nanometers. The emitted light has a spectral characteristic of less than 50% of the German Rhine standard and greater than 90% of the American Digital Cinema Joint Standard.

[0015] In one or more embodiments of the present disclosure, the wavelength range of the blue light is between 455 nanometers and 462 nanometers. The ratio of the first spectrum area of ​​the emitted light in the wavelength range between 415 nanometers and 455 nanometers to the second spectrum area in the wavelength range between 400 nanometers and 500 nanometers is less than 25%. The ratio of the first spectrum area to the third spectrum area in the wavelength range between 380 nanometers and 780 nanometers is less than 30%.

[0016] The above-mentioned embodiment of the present disclosure uses at least two green light conversion materials to reduce the light intensity ratio of the blue light band that is harmful to the eyes, but still maintains the breadth of the color gamut distribution. The relationship between the above-mentioned two green light conversion materials is that one has a wavelength distribution in the shorter wavelength range of green light but a wider half-height width, and the other has a wavelength distribution in the longer wavelength range of green light but a narrower half-height width.

[0017] In order to make the above features and advantages of the present disclosure more obvious and understandable, embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A cross-sectional view of a light emitting diode device in some embodiments of the present disclosure is shown;

[0019] Figure 2 A diagram showing a comparison of color gamut distribution characteristics of some embodiments of the present disclosure with color gamut standards and existing low blue light technologies;

[0020] Figure 3 A diagram comparing the spectral distribution of some embodiments of the present disclosure and existing low blue light products is shown.

[0021]

Explanation of symbols

[0022] 1000: Light Emitting Diode Device

[0023] 100: Blue light emitting diode

[0024] 200: Photoconversion materials

[0025] 210: first green light conversion material

[0026] 230: Second green light conversion material

[0027] 250: Red light conversion material

[0028] 300: Filling material

[0029] 400:Substrate

[0030] 500: Side wall

[0031] BL: Blue light

[0032] LO: Outgoing light

[0033] GL1: First Green Light

[0034] GL2: Second Green Light

[0035] RL: Red light

[0036] C1: First color gamut range

[0037] C2: Second color gamut range

[0038] C3: The third color gamut

[0039] S1: First spectral distribution

[0040] S2: Second spectral distribution DETAILED DESCRIPTION

[0041] In order to make the description of the present disclosure more detailed and complete, the following provides an illustrative description of the implementation and specific embodiments of the present disclosure; however, this is not the only form of implementing or using the specific embodiments of the present disclosure. The various embodiments disclosed below can be combined or replaced with each other under beneficial circumstances, and other embodiments can be added to one embodiment without further recording or explanation.

[0042] In the following description, many specific details will be described in detail to enable the reader to fully understand the following embodiments. However, the embodiments of the present disclosure can be practiced without these specific details. In other cases, in order to simplify the drawings, well-known structures and devices are only schematically depicted in the drawings.

[0043] refer to Figure 1 . Figure 1A cross-sectional schematic diagram of a light emitting diode device 1000 in some embodiments of the present disclosure is shown. The light emitting diode device 1000 includes a blue light emitting diode 100 and a light conversion material 200. The light conversion material 200 includes a first green light conversion material 210, a second green light conversion material 230, and a red light conversion material 250. In some embodiments, the light conversion material 200 can be uniformly distributed in the light output path of the blue light emitting diode 100 in the form of particles, and synergistically affect the wavelength distribution of the light output, but is not limited thereto. In some embodiments, the wavelength range of the blue light BL emitted by the blue light emitting diode 100 is between 445 nanometers and 470 nanometers.

[0044] The first green light conversion material 210 is used to convert the blue light BL emitted by the blue light emitting diode 100 and generate a first green light GL1 having a first wavelength range and a first wavelength half-width. The second green light conversion material 230 is used to convert the aforementioned blue light BL and generate a second green light GL2 having a second wavelength range and a second wavelength half-width. The second wavelength half-width is smaller than the first wavelength half-width, that is, the width of the second wavelength half-width is narrower than the width of the first wavelength half-width. In some embodiments, the first wavelength half-width is greater than or equal to 40 nanometers, and the second wavelength half-width is less than 40 nanometers. The lower limit of the first wavelength range of the aforementioned first green light GL1 is less than the lower limit of the second wavelength range of the second green light GL2, and the upper limit of the second wavelength range is greater than the upper limit of the first wavelength range. In other words, compared with the first green light GL1 and the second green light GL2, the first green light GL1 is located in the shorter wavelength region of the green light as a whole and has a wider wavelength half-width, while the second green light GL2 is located in the longer wavelength region of the green light as a whole and has a narrower wavelength half-width. By mixing and matching the first green light GL1 and the second green light GL2, the proportion of the blue light band that is harmful to the eyes can be effectively reduced while maintaining the color performance of a wide color gamut.

[0045] The first wavelength range and the second wavelength range can be two wavelength ranges that are completely separated (non-overlapping) or partially overlapping. In the partially overlapping embodiment, the mixed light spectrum of the first green light GL1 and the second green light GL2 will have a better symmetrical shape compared to the non-overlapping embodiment, and the color purity is further improved compared to the non-overlapping embodiment.

[0046] The red light conversion material 250 is used to convert the blue light BL and generate the red light RL. In some embodiments, the wavelength of the red light RL is between 610 nanometers and 660 nanometers.

[0047] Under the aforementioned mixed light of the first green light GL1, the second green light GL2, the red light RL and the part of the unconverted blue light BL, the output light LO emitted from the light emitting diode device 1000 has the German Rhine standard The spectral characteristics of the wide color gamut standard (e.g., NTSC or DCI-P3, the official name will be described later) are less than 50% and greater than 90%. For the embodiment of the present disclosure that maintains a wide coverage rate in the color gamut standard, please refer to Figure 2 . Figure 2 A comparison diagram is shown between the color gamut distribution characteristics of some embodiments of the present disclosure and the color gamut standards and existing low blue light technologies. The representation method is the chromaticity coordinate system of the International Commission on Illumination (CEI), that is, the common CIE1931 chromaticity coordinate diagram. In short, in this coordinate diagram, when x is greater than 0.6, it is red, and when y is greater than 0.6, it is green. Since the aforementioned CIE1931 chromaticity coordinate diagram is a standard commonly used coordinate diagram, the principle of the chromaticity coordinate diagram and the numerical value on the coordinate are omitted here.

[0048] Continue to refer Figure 2 , the first color gamut range C1 covered by the embodiment of the present disclosure can completely cover the second color gamut range C2 covered by the standard red green blue space (sRGB). Furthermore, the embodiment of the present disclosure can also completely cover the third color gamut range C3 covered by the existing liquid crystal display (LCD). Figure 2 The presented comparison shows that the first color gamut range C1 covered by the embodiments of the present disclosure has at least the same or higher color gamut coverage as that of the prior art.

[0049] Two exemplary embodiments are disclosed below, and the wavelength distribution and materials of the first green light GL1 and the second green light GL2 are disclosed in more detail. Other parts not specifically mentioned, such as the wavelength range of the red light RL, can be regarded as the same as the description in the above paragraph. It should be noted that these two types of embodiments are not intended to directly limit the scope of protection of the present disclosure.

[0050] In the first type of embodiment, the union of the first wavelength range of the first green light GL1 and the second wavelength range of the second green light GL2 is between 490 nanometers and 540 nanometers. In some specific embodiments, the first wavelength range is between 510 nanometers and 530 nanometers, and the first wavelength half-width is between 60 nanometers and 100 nanometers. The second wavelength range is between 520 nanometers and 540 nanometers, and the second wavelength half-width is between 20 nanometers and 40 nanometers. Under the above conditions, the output light LO also has the German Rhine standard (i.e., the aforementioned The spectral characteristics of the color television broadcast standard (WCG-NTSC) set by the National Television System Committee of the United States) are less than 50% and greater than 95%. In more detail, the first green light GL1 with a shorter green light wavelength has a wider first wavelength half-width than the second green light GL2, which helps to achieve the aforementioned low blue light effect.

[0051] In some specific embodiments of the first type, the wavelength range of the blue light BL is between 455 nanometers and 460 nanometers, and the ratio of the first spectral area of ​​the output light LO in the wavelength range between 415 nanometers and 455 nanometers to the second spectral area in the wavelength range between 400 nanometers and 500 nanometers (i.e. Standard) is less than 25%, and can even be less than 20%. In addition, the proportion of the first spectral area to the third spectral area in the wavelength range between 380 nanometers and 780 nanometers is less than 30%. The "spectral area" referred to here is the area surrounded by the spectral curve on the coordinate (with the curve itself as the upper boundary of the vertical axis and the vertical axis as zero as the lower boundary of the vertical axis) when the horizontal axis is the wavelength and the vertical axis is the light intensity. This area represents the overall (i.e., entering the eye) light intensity of the wavelength range of interest. The aforementioned proportions reflect that these specific embodiments can take into account both the wide color gamut and the effect of reducing the harm of blue light to the eyes. The above-mentioned low blue light presentation is better than the low blue light products of the prior art that use 460 nanometer blue light. These existing low blue light products Only about less than 28% can be achieved.

[0052] In a second type of embodiment, the union of the first wavelength range of the first green light GL1 and the second wavelength range of the second green light GL2 is between 500 nanometers and 545 nanometers. In some specific embodiments, the first wavelength range is between 515 nanometers and 540 nanometers, and the first wavelength half-width is between 60 nanometers and 100 nanometers. The second wavelength range is between 525 nanometers and 550 nanometers, and the second wavelength half-width is between 20 nanometers and 40 nanometers. The output light LO has a spectral characteristic of less than 50% of the German Rhine standard and greater than 90% of the American Digital Cinema Initiatives P3 (DCI-P3) standard.

[0053] In some specific embodiments of the second type, the wavelength range of the blue light BL is between 455 nanometers and 462 nanometers, and the first spectrum area of ​​the emitted light LO in the wavelength range between 415 nanometers and 455 nanometers accounts for less than 25% of the second spectrum area in the wavelength range between 400 nanometers and 500 nanometers, and the first spectrum area accounts for less than 30% of the third spectrum area in the wavelength range between 380 nanometers and 780 nanometers. The above proportions reflect that these specific embodiments can take into account both the wide color gamut and the effect of reducing the harm of blue light to the eyes.

[0054] In the above two types of embodiments, the first green light conversion material 210 can be selected from one or a combination of materials such as yttrium aluminum garnet (YAG), lutetium aluminum garnet (LuGA), silicate, nitrogen oxide phosphor (for example, BaSrSi2N2O2), etc. The second green light conversion material 230 can be selected from green quantum dots (GQD), silicate phosphors (for example, NaK(Li 3 SiO 4 ) 2 or UNB) or a combination of materials.

[0055] The UNB light conversion material is a light conversion material that includes the general formula (1) listed below and satisfies the following condition (2). The general formula (1) is M m A a C c E e :ES x RE y . M is at least one element selected from the group consisting of Ca, Sr and Ba, wherein 2≤m≤3. A is at least one element selected from the group consisting of Mg, Mn, Zn and Cd, wherein 0.01≤a≤1. C is at least one element selected from the group consisting of Si, Ge, Ti and Hf, wherein 1≤c≤9. E is at least one element selected from the group consisting of O, S and Se, wherein 5≤e≤7. ES is at least one element selected from the group consisting of divalent Eu, Sm and Yb, wherein 0≤x≤3. RE is at least one element selected from the group consisting of trivalent Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er and Tm, wherein 0≤y≤3. Condition (2) is x+y=3.

[0056] The aforementioned benefits of simultaneously taking into account a wide color gamut and protecting the eyes from eye damage (also known as low blue light) can be explained and reflected by the light wavelength distribution of the embodiment disclosed in the present invention. Figure 3 . Figure 3 A comparison diagram of the spectral distribution of some embodiments of the present disclosure and existing low blue light products is drawn. As shown by the arrows in the figure, the difference between the first spectral distribution S1 presented in some embodiments of the present disclosure and the second spectral distribution S2 presented in the existing low blue light products is that the first spectral distribution S1 has a higher light intensity peak (bump) in the range between about 520 nanometers and about 550 nanometers than the second spectral distribution S2. The remaining spectral ranges not drawn with dotted lines represent the overlapping parts of the first spectral distribution S1 and the second spectral distribution S2. In this way, while reducing the proportion of the blue light band that is harmful to the eyes, the light intensity of the green light range to which the human eye is most sensitive (i.e., the light between about 520 nanometers and about 550 nanometers mentioned above) can still be maintained, so as to achieve the purpose of this paragraph while taking into account the wide color gamut and protecting the eyes from eye damage.

[0057] In some embodiments, the LED device 1000 further includes a filling material 300, which is distributed around the blue LED 100 and can be used to improve or adjust the light extraction efficiency of the LED device 1000 by matching the refractive index, and can also be used to mix with the first green light conversion material 210, the second green light conversion material 230 and the red light conversion material 250 described above. In a specific embodiment, the LED device 1000 can also include a substrate 400 that supports the blue LED 100 and a sidewall 500 that guides the light path in the direction of emission. It should be noted that the content of this paragraph is only an example of the possibility of certain applications, and is not intended to limit the scope of protection of the present disclosure.

[0058] In summary, the embodiments disclosed herein provide a light emitting diode device, which achieves the dual benefits of reducing the proportion of blue light bands that are harmful to the eyes and maintaining the breadth of the color gamut distribution through the combination of a blue light emitting diode, a first green light conversion material, a second green light conversion material, and a red light conversion material. The wavelength of the first green light conversion material is distributed in a shorter green light wavelength range but has a wider half-height width, and the wavelength of the second green light conversion material is distributed in a longer green light wavelength range but has a narrower half-height width.

[0059] Although the present disclosure has been disclosed as above by way of embodiments, it is not intended to limit the present disclosure. Anyone skilled in the art may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the scope of protection of the present disclosure shall be determined by the scope defined in the attached claims.

Claims

1. A light emitting diode device, characterized in that: include: a blue light emitting diode; A light conversion material is distributed on the light output path of the blue light emitting diode, and the light conversion material includes: A first green light conversion material, used for converting a blue light emitted by the blue light emitting diode and generating a first green light having a first wavelength range and a first wavelength half-width; a second green light conversion material, for converting the blue light and generating a second green light having a second wavelength range and a second wavelength half-width, wherein the second wavelength half-width is smaller than the first wavelength half-width, wherein a lower limit of the first wavelength range is smaller than a lower limit of the second wavelength range, and an upper limit of the second wavelength range is larger than an upper limit of the first wavelength range; as well as a red light conversion material, used for converting the blue light to generate a red light; The light emitting diode device emits an outgoing light, and the outgoing light has a spectrum characteristic of a wide color gamut standard greater than 90%, and the wide color gamut standard is selected from at least one of the color television broadcasting standard formulated by the National Television System Committee of the United States (WCG-NTSC) and the Digital Cinema Initiatives P3 (DCI-P3); The first wavelength half-width is between 60 nanometers and 100 nanometers, the second wavelength half-width is between 20 nanometers and 40 nanometers, and the ratio of a first spectral area of ​​the emitted light in the wavelength range between 415 nanometers and 455 nanometers to a second spectral area in the wavelength range between 400 nanometers and 500 nanometers is less than 25%.

2. The light emitting diode device according to claim 1, characterized in that: The wavelength of this blue light ranges between 445 nanometers and 470 nanometers.

3. The light emitting diode device according to claim 1, characterized in that: The wavelength of the red light ranges between 610 nanometers and 660 nanometers.

4. The light emitting diode device according to claim 1, characterized in that: The first wavelength range and the second wavelength range together cover a range between 490 nanometers and 540 nanometers.

5. The light emitting diode device according to claim 4, characterized in that: The first wavelength range is between 510 nanometers and 530 nanometers, the second wavelength range is between 520 nanometers and 540 nanometers, the first wavelength half-width is between 60 nanometers and 100 nanometers, the second wavelength half-width is between 20 nanometers and 40 nanometers, and the emitted light has a spectral characteristic of a wide color gamut standard greater than 95%, and the wide color gamut standard is selected from the color television broadcasting standard (Wide Color Gamut National Television System Committee, WCG-NTSC) formulated by the National Television System Committee of the United States.

6. The light emitting diode device according to claim 5, characterized in that: The wavelength range of the blue light is between 455 nanometers and 460 nanometers, and the ratio of the first spectrum area to a third spectrum area in the wavelength range between 380 nanometers and 780 nanometers is less than 30%.

7. The light emitting diode device according to claim 1, characterized in that: The first wavelength range and the second wavelength range together cover a range between 500 nanometers and 545 nanometers.

8. The light emitting diode device according to claim 7, characterized in that: The first wavelength range is between 515 nanometers and 540 nanometers, and the emitted light has a spectrum characteristic of a wide color gamut standard greater than 90%, and the wide color gamut standard is selected from the American Digital Cinema Initiatives P3 (DCI-P3).

9. The light emitting diode device according to claim 8, characterized in that: The wavelength range of the blue light is between 455 nanometers and 462 nanometers, and the ratio of the first spectrum area to a third spectrum area in the wavelength range between 380 nanometers and 780 nanometers is less than 30%.

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