WO2020000511A1

WO2020000511A1 - Optimization method for led light source

Info

Publication number: WO2020000511A1
Application number: PCT/CN2018/095304
Authority: WO
Inventors: 曾胜; 曾灵芝; 曾骄阳; 陈俊达; 陈道蓉
Original assignee: 朗昭创新控股（深圳）有限公司
Priority date: 2018-06-27
Filing date: 2018-07-11
Publication date: 2020-01-02
Also published as: CN109027720A

Abstract

An optimization method for an LED light source, comprising: selecting a first light emitting body used for emitting white light; optimizing the white light to be first near-natural light; according to the optical spectrum of the first near-natural light and that of natural light, determining a wave band to be optimized; selecting a second light emitting body according to the wave band to be optimized; illuminating the first light emitting body and the second light emitting body according to a preset light flux ratio; and optimizing a combined optical spectrum by adjusting the optical spectrum distribution of the first light emitting body and/or that of the second light emitting body so as to obtain quasi-natural light. The relative optical spectrum power of each wave band of the quasi-natural light obtained by means of the method is close to the optical spectrum power of the natural light, and therefore, the present invention facilitates protecting eyesight and reducing the vision health problem of people being in a high blue light illumination environment for a long time; the present invention can maintain a high color temperature while achieving low blue light, can maintain a high-definition visual effect with a high identification degree, and a good metal state while improving a health level, and can improve the relative optical spectrum power of red light, thereby improving the health level of quasi-natural light illumination.

Description

Optimization method of LED light source

Technical field

The invention relates to the field of LED technology, and in particular, to an optimization method for an LED light source.

Background technique

The emergence of artificial light solves the problem of lighting at night or in a dark environment, but also greatly changes the circadian rhythm of people's long-term formation of natural light. The harm caused by ordinary artificial light to people cannot be ignored. This hazard mainly comes from the spectral incompleteness of artificial light compared to natural light, as well as higher blue light components and shorter wavelengths of violet and ultraviolet light components. In addition, the optical output of artificial light sources (such as color temperature, color coordinates, etc.) The difference from natural light is also large, which also affects people's sensory experience and makes people feel unnatural and uncomfortable.

The visible light seen by the human eye is part of the entire electromagnetic spectrum, and the visible spectrum is approximately 390-760nm. Of the light in this band, ultraviolet, violet and blue light are the most harmful to human eyes. The damage of purple light to the eyes is in the front half of the eyeball (such as eyelid cancer, cataracts, blepharoplasia, abnormal patches, etc.). The damage of blue light to the eyes is in the second half of the eyeball, which can cause macular lesions. Because blue light accelerates the oxidative stress of photoreceptor cells and retinal pigment epithelial cells in the macular region of the retina, which causes damage, these two types of cells are non-renewable. Once the damage, it will affect vision and irreversible. blindness. Among the cells of the human retina, the blue-sensing cells are relatively small, and blue light will be scattered into the eyes beyond a certain limit. When scattering occurs, the light will diffuse and the texture and color of the object will be distorted. The damage of blue light to the eyes, especially the visual impairment of minor students and children, is relatively obvious, which will cause children's color weakness, reduce children's color discrimination ability, and lead to the increase of myopia rate of minors.

While we pay attention to the objective visual effects of light, we should also consider people's perception of light, such as the impact of light on human health, mood, comfort, and physiological changes. For example, the lamps in the office are usually high color temperature light sources to improve the visibility and work mood of the staff. It contains high blue light components. Working office workers have been in artificial light sources for a long time, or have been watching computers and mobile phones for a long time. Dizziness, eye pain, headache, and mental illness may occur, which seriously affect people ’s health. Some people's skin is sensitive to violet light and ultraviolet light, and long-term watching the computer can cause various skin problems. In natural light, you will feel comfortable and relaxed.

With the development of lighting technology, people's requirements for the overall performance of light quality and comfort are constantly increasing, and various new light sources and technologies are emerging, such as LED light sources that simulate the natural light spectrum, and dynamic intelligent lighting technologies. Undoubtedly, the most ideal lighting light is natural light, and natural light lighting has always been the vision of the lighting industry.

The white light lighting products in the existing LED technology still have a large difference between their spectrum and natural light, and their blue light ratio is high. As shown in Figure 10, it shows the spectrum of a white light source using a blue light chip combined with a phosphor. Due to the chip's wavelength range and luminous intensity and the wavelength range of the phosphor, there are certain restrictions, so the spectral difference between this combination structure and natural light is still Larger, especially if the proportion of blue light is too high.

As shown in FIG. 11, it illustrates the spectrum of a white light source using a combination of chips (or sub-light sources) with multiple wavelengths, such as a three-primary-color combination structure of a red light chip, a green light chip, and a blue light chip. Visible light, but this white light has obvious sharp peaks at the three central wavelengths of red, green, and blue, and other wavelengths are relatively low, which is far from the natural spectrum; and the structure is difficult to achieve uniform light mixing and large size; In addition, the driving method of multiple chips (or sub-light sources) is complicated, requiring a control chip, the circuit is complicated, the application is inconvenient, and the applicability is poor.

It can be seen that the light sources in the prior art all have defects that are significantly different from natural light. Today, with the rapid development of science and technology, the proportion of children with visual impairment and sub-healthy people is increasing. Providing healthy quasi-natural light, improving children's vision, and protecting people's health have become urgent social needs.

technical problem

The purpose of the present invention is to provide a method for optimizing an LED light source, which aims to obtain a quasi-natural light source by this method, solve the technical problem that the traditional LED light source is greatly different from natural light, and improve the health level of the people.

Technical solutions

To solve the above technical problems, the technical solutions adopted in the embodiments of the present invention are:

An optimization method for an LED light source includes the following steps:

Selecting a first luminous body, which is used for emitting white light;

Optimizing the spectral distribution of the first luminous body and optimizing the white light to the first near-natural light;

Determining a to-be-optimized wavelength band of the first near-natural light according to the spectral distribution of the first near-natural light and the spectral distribution of the natural light;

Selecting a second light emitter according to the to-be-optimized band;

Lighting the first and second light emitters according to a preset luminous flux ratio of the first and second light emitters;

By adjusting the spectral distribution of the first light emitter and the second light emitter, the combined spectrum of the first light emitter and the second light emitter is optimized to obtain quasi-natural light.

Beneficial effect

The beneficial effect of the method for optimizing the LED light source provided by the embodiment of the present invention is that the first near-natural light is emitted by the first luminous body, and the missing portion of the first near-natural light is compensated by adding the second luminous body. Relative to the reasonable range of spectral power and optical parameters, in the optimization process, by adjusting the spectral distribution of the first and second illuminants, the shape of the combined spectrum and the corresponding optical parameters meet predetermined requirements to obtain quasi-natural light. The quasi-natural light obtained by this method can be closer to the characteristics of natural light, which solves the problems of incomplete spectrum of traditional light sources, partial waveband loss, and substandard optical parameters, which is beneficial to protecting vision and physical health. It is of great significance in the field of LED lighting technology. Technology breakthrough.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flowchart of a method for optimizing an LED light source according to an embodiment of the present invention; FIG.

FIG. 2 is a schematic spectrum diagram of a first luminous body provided by an embodiment of the present invention; FIG.

3 is a schematic diagram of a natural light spectrum;

4 is a flowchart of step S106 of the method for optimizing an LED light source according to an embodiment of the present invention;

5 is a schematic diagram of a spectrum of quasi-natural light according to an embodiment of the present invention;

FIG. 6 is a spectrum comparison diagram of quasi-natural light and natural light provided by an embodiment of the present invention; FIG.

7 is a chart of a spectrum test report of quasi-natural light shown in FIG. 5;

8 is a schematic diagram of a white light spectrum when a 452.5-455 nm blue light chip is used according to an embodiment of the present invention;

9 is a schematic structural diagram of a quasi-natural-light LED light source according to an embodiment of the present invention;

10 is a first spectrum diagram of a white light source in the prior art;

11 is a second spectrum diagram of a white light source in the prior art;

FIG. 12 is a spectrum diagram of a near-natural light source in the prior art.

Embodiments of the invention

In order to make the objectives, technical solutions, and advantages of the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

Explanation of technical terms:

1. Relative spectral power:

The spectrum emitted by a light source is often not a single wavelength, but a mixture of many different wavelengths. The spectral radiation of a light source in terms of wavelength order and intensity distribution at each wavelength is called the spectral power distribution of the light source.

The parameters used to characterize the spectral power are divided into absolute spectral power and relative spectral power. Further absolute spectral power distribution curve: refers to the curve made by the absolute value of light energy of various wavelengths of spectral radiation;

Relative spectral power distribution curve: refers to the spectral power distribution curve that compares the energy of various wavelengths of the light source's radiation spectrum with each other and normalizes the radiated power to change only within a specified range. The maximum relative spectral power of the radiated power is 1, and the relative spectral powers of other wavelengths are all less than 1.

2. Color ratio:

Any white light can be obtained by mixing the three primary colors of red, green, and blue in corresponding proportions. In order to indicate the relative proportions of the three primary colors of R, G, and B in the total white light, the chromaticity coordinates r, g, and b are introduced, where r = R / (R + G + B), g = G / (R + G + B), b = B / (R + G + B), r + g + b = 1, r, g, and b are red light colors Ratio, green light color ratio, blue light color ratio.

In order to explain the technical solution of the present invention, detailed description is given below with reference to specific drawings and embodiments.

Referring to FIG. 1, an embodiment of the present invention provides a method for optimizing an LED light source, including the following steps:

Step S101, selecting a first light emitter, the first light emitter is used to emit white light;

Step S102, optimizing the spectral distribution of the first luminous body, and optimizing the white light into the first near-natural light;

Step S103: Determine a to-be-optimized wavelength band of the first near-natural light according to the first near-natural light spectral distribution and the natural light spectral distribution;

Step S104, selecting a second light emitter according to the waveband to be optimized;

Step S105, lighting the first light emitter and the second light emitter according to a preset luminous flux ratio of the first light emitter and the second light emitter;

In step S106, by adjusting the spectral distribution of the first light emitter and the second light emitter, the combined spectrum of the first light emitter and the second light emitter is optimized to obtain quasi-natural light.

The LED light source optimization method emits the first near-natural light through the first luminous body, and then compensates for the missing part of the spectrum in the first near-natural light by adding the second luminous body. By setting the relative spectral power and the reasonable range of optical parameters of each band of the spectrum In the optimization process, by adjusting the spectral distribution of the first luminous body and the second luminous body, the shape of the combined spectrum and the corresponding light parameters meet predetermined requirements to obtain quasi-natural light. The quasi-natural light obtained by this method can be closer to the characteristics of natural light, which solves the problems of incomplete spectrum of traditional light sources, partial waveband loss, and substandard optical parameters, which is beneficial to protecting vision and physical health. It is of great significance in the field of LED lighting technology Technology breakthrough.

The optimization method is explained in detail below.

In steps S101 and S102, a white light emitting body is first selected as the first light emitting body, and the white light emitting body is used as the main light emitting body. The main light emitting body includes a large wavelength range, including at least a 400-640 nm band.

The white light emitting body in this embodiment adopts a structure in which a blue light chip is matched with an optical conversion film. Of course, the present invention is not limited to this, and white light that meets the corresponding requirements can also be obtained through other structures.

In the present invention, the optical conversion film may be a fluorescent film or a phosphorescent film. This embodiment is preferably a fluorescent film, and the following description uses the fluorescent film as an example for description.

After step S102, the white light is optimized to the first near-natural light, so that the white light is as close as possible to the natural light. During the optimization process, the relative spectral power of the white light is increased as much as possible, so that the type of the subsequent second light emitter is selected. It is simpler, and it is beneficial to optimize the spectrum of the two light emitters.

Specifically, in conjunction with FIG. 2, this figure illustrates a spectral curve of the first near-natural light. The color temperature range of the optimized first near-natural light includes at least 2700-6000K, and the relative spectral power of each band can be within different color temperature ranges. Reached a predetermined range. Specifically, when the color temperature of the first near-natural light is 2700K-3000K, the relative spectral power of the 480-500nm band is greater than 0.30; the relative spectral power of the 500-640nm band is greater than 0.70; when the color temperature of the first near-natural light is 4000K-4200K When the relative spectral power of the 480-500nm band is greater than 0.45; the relative spectral power of the 500-640nm band is greater than 0.65; when the color temperature of the first near-natural light is 5500K-6000K, the relative spectral power of the 480-500nm band is greater than 0.4; 500- The relative spectral power in the 640nm band is greater than 0.60.

In visible light, the correspondence between wavelength and color is as follows: red light (622 ~ 700nm), orange light (597 ~ 622nm), yellow light (577 ~ 597nm), green light (492 ~ 577nm), cyan light (475 ~ 492nm), Blue light (435 ~ 475nm), purple light (380 ~ 435nm). The above 480-500nm band mainly includes cyan light, a small amount of blue light, and a small amount of green light, and the 500-640nm band mainly includes green light, yellow light, and red light.

Referring to the natural light spectrum shown in FIG. 3 and the first near-natural light spectrum shown in FIG. 2 at the same time, it can be seen that the band is between 400-640nm, which is closer, but in the red light portion greater than 640nm, the first near-natural light exists The obvious lack is a sharp decrease in relative spectral power. Therefore, it can be determined that red light needs to be supplemented. Furthermore, it involves selecting a second light-emitting body that emits red light. On the one hand, it is used in combination with the first light-emitting body to obtain illumination light closer to natural light; on the other hand, by supplementing red light, blue light can be reduced. This conclusion can be passed The previous basic research confirmed that the content of basic research will be explained in detail later.

Therefore, in step S103, it is determined that the to-be-optimized wavelength band of the first near-natural light is 640-700 nm; a second light emitter is selected according to the requirement, and the second light emitter can emit at least 640-700 nm red light. Specifically, it can be a smaller interval within this range, for example, the wavelength range is 680-700nm, and the corresponding center wavelength is 690 ± 5nm. The center wavelength is usually the center value of the wavelength range, and an adjustable interval of about ± 2nm is allowed. In the case of different sections, the center wavelength may also be 660 nm, 670 nm, 680 nm, and the like, and this embodiment is not limited to a certain one. Further, according to the spectral curve of the first near-natural light, and through a large number of combined spectrum debugging experiments, it is determined that the center wavelength of the second luminous body is preferably 690 ± 5 nm, in order to make it as possible as possible after combining with the first near-natural light spectrum. The relative spectral power of 640-700nm red light is close to the spectrum of natural light.

In steps S104 and S105, after determining the first light emitter and the second light emitter, a reasonable luminous flux ratio may be selected according to the spectra of the two light emitters, that is, the light flux of the first light emitter and the light radiation amount of the second light emitter. This ratio is referred to herein as the "initial luminous flux ratio". According to the above-mentioned wavelength range and spectral characteristics of the first near-natural light and red light, it can be initially determined that the initial luminous flux ratio is within the range of 2-10: 1. Further, through experiments, it can be further determined that the initial luminous flux ratio is in a range of 2-5: 1, and then a corresponding number of first luminous bodies and a corresponding number of second luminous bodies are lit according to a preset initial luminous flux ratio for optimization. The process of combining spectra.

The optimization process of step S106 is crucial, mainly by adjusting the luminous flux of the first luminous body and the light radiating amount of the second luminous body at the same time, that is, by adjusting the spectra of both at the same time; or separately adjusting the luminous flux of the first luminous body Or the amount of light radiation of the second luminous body, that is, the spectrum of a certain luminous body is adjusted for optimization; when the relative spectral power (shape) and optical parameters of the combined spectrum meet the requirements, it is confirmed that quasi-natural light is obtained. It can be understood that the “requirement” is a predetermined parameter range, and reference may be made to a reasonable setting of a parameter range recognized by most of the public in the technical field.

As an example of step S106, the luminous flux of the first luminous body and the light radiating amount of the second luminous body are mainly adjusted by adjusting the driving current of the first luminous body and the second luminous body. In the process of changing the current, the luminous flux or The amount of light radiation changes accordingly. This step is to adjust the current to debug the quasi-natural light that meets the requirements.

Further, in the process of optimization and debugging, the first light-emitting body and the second light-emitting body can be connected to different driving circuits and driven independently by different currents. Of course, it is more preferable if the preset purpose can be achieved by adjusting the same driving current. However, after a large number of experiments, it has been proved that it is very difficult to achieve quasi-natural light by applying the same driving current to the first and second illuminants.

Referring specifically to FIG. 4, step S106 includes the following sub-steps:

S1: Adjust the driving current of the first and second luminous bodies, and monitor the combined spectrum in real time. When the relative spectral power of each band of the combined spectrum reaches a predetermined range, go to step S2, otherwise repeat step S1;

S2: Detect the optical parameters of the combined spectrum. When the optical parameters reach a predetermined range, go to step S3, otherwise go back to step S1;

S3: Record the actual ratio of the light flux of the first luminous body and the light radiation amount of the second luminous body, the actual driving current of the first luminous body and the second luminous body, and the corresponding optical parameters.

The above steps disclose the specific implementation process of step S106. First, the luminous flux of the first luminous body and the luminous radiation of the second luminous body are adjusted respectively by adjusting the driving current. At this time, the combined spectrum will change. After several debugging, the combination The shape of the spectrum (that is, the relative spectral power of each band) is close to the allowable range of natural light. At this time, confirm that the spectrum meets the requirements. On this basis, check the optical parameters. If the optical parameters meet the preset range, it is determined that the debugging of the quasi-natural light is over. At this time, at least the actual ratio of the corresponding luminous flux of the first luminous body and the luminous radiation amount of the second luminous body should be recorded to accurately determine the ratio. It is also necessary to record the drive current, as well as the optical parameters mentioned above. This data is used to provide the necessary information for the production of light sources.

Preferably, further information such as the corresponding quasi-natural light spectrum diagram, chromaticity diagram, other electrical parameters, light effect parameters, red, green, and blue ratio parameters are further stored. Of course, various optical parameters of the first illuminant and the second illuminant will be saved when they are selected, such as the wavelength range, center wavelength, model, specifications, rated current, light efficiency, and so on.

In one embodiment, the optical parameters mentioned in the above step S2 include at least color temperature, color coordinates, color tolerance, color rendering index Ra, color rendering index R9, color rendering index R12, and blue light color ratio.

In this embodiment, the predetermined range of color tolerance is less than 5, the predetermined range of color rendering index RA is greater than 90, the predetermined range of color rendering index R9 and color rendering index R12 is greater than 80, and the predetermined range of blue light color ratio is Less than 5.7%, the blue light color ratio of the existing near-natural light source is still high, as shown in Figure 13. According to the research results published by the top international academic journals such as "Nature", among the cells of the human retina, the cells that sense blue are only 5.7%, so this embodiment reduces the blue light color ratio to below 5.7%. The predetermined range of the color rendering index R9 can be increased to more than 90, and the predetermined range of the color rendering index R12 is greater than 80.

With further reference to FIGS. 5 and 7, by optimizing the first luminous body and optimizing the combined spectrum, when the spectral shape meets the requirements, the color rendering index Ra is increased to more than 97, the color rendering index R9 is more than 95, and the color is developed. The index R12 reaches above 80, and the blue light color ratio can be reduced to below 5.5%.

As a further optimization scheme, blue light at 440 nm of blue light has the greatest damage to vision. In this embodiment, the relative spectral power of blue light at 440 nm is used as the optical parameter to be detected. When the blue light color ratio is lower than 5.7%, it is further determined that the relative spectral power of the 440nm blue light needs to be lower than 0.65. This is difficult to achieve with existing eye protection electronic equipment. Although the current "eye-protection" electronic products have a low blue-light color ratio, the suppression of the 440nm blue light that is most harmful to human eyes is not obvious, and the eye-protection function is minimal. And other wavelength components in blue light are necessary for vision development. Significant suppression of blue light not only has ineffective eye protection effects, but also adversely affects the visual development of children, young children and other people. For example, the excessive loss of blue light components causes color weakness. And other issues. In this embodiment, on the basis of reducing the blue light color ratio to below 5.7%, the focus is on suppressing the intensity of blue light at 440 nm, which can truly protect the eyesight, and retain part of the blue light, so that the white light is closer to natural light.

Further, after the above steps S1-S3, it is determined that the actual ratio of the light flux of the first light-emitting body and the light radiation amount of the second light-emitting body is 2-3: 1. When the color temperature of quasi-natural light is different, the actual ratio is slightly different, and the driving current is also slightly different. For each color temperature, the corresponding data is recorded to provide the necessary data for the manufacture of the light source. Specifically during manufacture, several color temperature products can be selected according to actual application requirements. For example, the lamps used in office places usually choose products with higher color temperature, and the lamps used in home usually choose products with lower color temperature.

In the present invention, step S1 states: when the relative spectral power of each band of the combined spectrum reaches a predetermined range, step S2 is performed, otherwise step S1 is repeated; when step S2 is described: when the optical parameters reach a predetermined range, Step S3, otherwise go back to step S1. That is, there is a possibility that the relative spectral power of the combined spectrum cannot reach a predetermined range in step S1, and there is also a possibility that the optical parameters cannot reach a predetermined range in step S2. In this case, it is necessary to repeat step S1 to adjust the driving current. However, when the number of times the drive current is adjusted reaches a certain level, other factors need to be considered to solve the above problems.

Further, in this case, there are two options, one is to perform step S4: adjust the formula and / or concentration and / or thickness of the optical conversion film, and then return to step S1; and the other is to perform step S5: adjust The central wavelength of the second illuminant or a third illuminant whose central wavelength is different from the second illuminant is increased, and then the process returns to step S1. According to the previous basic research, the relationship between the fluorescent film and the spectrum optimization and the relationship between the red light and the spectrum optimization can be obtained. Under the corresponding theoretical guidance, an appropriate method can be selected to adjust the optimization scheme.

Specifically, in the first embodiment, step S4 is performed. The fluorescent film of the first luminous body has an important influence on the spectral distribution and light parameters of the first luminous body, and specifically includes: first, the formula of the fluorescent film mainly affects the relative spectral power of each band and the color rendering index; the formula refers to fluorescence The composition and ratio of the phosphor material in the film. Second, the concentration of the fluorescent film mainly affects the color rendering index and the color temperature; the concentration refers to the content of the phosphor in the fluorescent film under the condition of the determined formula; third, the thickness of the fluorescent film mainly affects the color temperature.

In the second embodiment, step S5 is performed: adjusting the central wavelength of the second luminous body or increasing a third luminous body with a central wavelength different from the second luminous body, and optimizing the combination with the first luminous body. Through a large number of basic studies, it can be determined that the second luminous body also has an important influence on the combined spectral distribution and light parameters.

Specifically, basic research 1: research on quasi-natural light spectrum.

Natural light in the natural world comes from the sun's luminescence. Natural light varies from season to season and even at different times of the day. It is mainly manifested in differences in spectrum and color temperature. The morning sunlight in spring is most comfortable. In the embodiment of the present invention, the sunlight spectrum in spring morning can be selected as a reference, and the relative spectral power and light parameters of natural light are set. Of course, this is a preferred embodiment, and natural light at other times can also be used as a measure to set the corresponding parameter requirements of quasi-natural light. The optimization method provided by the embodiment of the present invention is applicable to natural light at various times, and only some parameters need to be slightly adjusted.

Basic Research 2: The relationship between the spectral shape and the formula of the fluorescent film. Studies have shown that the formula of the fluorescent film has a great relationship with its corresponding spectral shape; changing the proportion of a powder in the formula will directly change the relative spectral power of its corresponding wavelength band. The larger the ratio, the greater the relative spectral power of the corresponding wavelength. , Will also change the color rendering index. Based on this, when the spectral shape and the explicit index do not meet the requirements, you can choose to increase or decrease the proportion of a certain powder or change the color coordinate parameters of a certain powder according to the specific band.

Basic research three: the relationship between the spectral shape and the concentration of the fluorescent film. Studies have shown that with the same formula, the higher the phosphor concentration, the higher the relative spectral power of 490-700nm will be, until it exceeds the blue spectral power. As the relative spectral power of blue light decreases, the color temperature will follow. As the light color decreases, the indicator also changes. Based on this, the index and color temperature can be changed by changing the density. However, when the density is adjusted to a certain state and the color temperature still does not meet the requirements, the formula ratio of various powders in the fluorescent film needs to be changed to ensure that the light colors of different color temperatures conform to international standards (ie, the color coordinates of the standard color temperature).

Basic research 4: The relationship between the spectral shape and color temperature and the thickness of the fluorescent film. Studies have shown that with the same formulation and concentration, the larger the thickness of the fluorescent film, the lower the color temperature. Based on this, when the color temperature does not meet the requirements, the color temperature can be adjusted by changing the thickness, and the impact on other parameters is small.

Basic research 5: The relationship between driving current and spectral shape change. Studies have shown that the relationship between driving current and spectral shape change is: (1) Increasing the driving current of any one chip (blue light chip or red light chip) will change its corresponding spectral power; (2) by adjusting Driving current can get the best spectrum optimization results; (3) Increasing the driving current of one chip to increase its luminous flux will suppress the relative spectrum of the other chip. Based on this, the combined spectrum can be adjusted by adjusting the driving current and blue light can be suppressed, that is, blue light can be suppressed by adding a red light chip.

Basic research 6: The relationship between the specifications of the red light chip and the amount of light radiation. Studies have shown that the relationship between the specifications of red light chips and the amount of light radiation is: under constant driving current conditions, in general, as the size of the chip increases, the amount of light radiation will increase. Based on this, the specifications of the red light chip with the best cost performance can be determined according to the final actual luminous flux ratio. The best price-performance ratio means that the size is as small as possible, but it can meet the welding requirements, the light efficiency is as high as possible, the reliability is good, and the price is also taken into account.

The present invention also performs basic research VII: the relationship between the luminous flux of white light emitters and the optimization of quasi-natural light spectrum, and basic research VIII: the relationship between the light radiation of red light chips and the optimization of quasi-natural light spectrum. Carry out basic research 7 To find the specifications of the best (cost-effective) blue light chip and the formula and concentration and thickness of the fluorescent film; to find blue light chips and fluorescent films that make the light emitted by the first luminous body close to the natural spectrum as much as possible; basic research 8 The aim is to find the best (cost-effective) specifications of the red light chip, to find the best value of the light radiation quantity (specification) of the red light chip that suppresses the relative spectrum of blue light, and to find the red light chip that makes the combined spectrum close to the natural spectrum as much as possible .

After the above theoretical guidance and a large number of experimental debuggings, the specifications and parameters of the first and second illuminants were determined. details as follows:

A second light source with a wavelength band and a central wavelength is combined with the first light source to form an LED light source. The second light source includes a red light chip with a wavelength range of 640-700 nm, and the center wavelength is preferably 690 ± 5 nm. It includes a blue light chip with a wavelength of 450-480 nm and an optical conversion film. Further preferably, the optical conversion film is a fluorescent film. The ratio of the luminous flux of the first luminous body to the luminous radiation amount of the second luminous body is 2-3: 1. During the debugging process, specific luminous flux ratios corresponding to different color temperatures can be determined. At the manufacturing end, according to the luminous flux ratio, corresponding numbers of red light chips and blue light chips are selected.

Further, the fluorescent film includes silica gel and a fluorescent powder. The fluorescent powder is a main factor affecting the light emitting characteristics of the first luminous body. The fluorescent powder includes: red powder, green powder, and yellow-green powder;

The color coordinates of the red powder are X: 0.660 to 0.716, Y: 0.340 to 0.286;

The color coordinates of green powder are X: 0.064 ～ 0.081, Y: 0.488 ～ 0.507;

The color coordinates of yellow-green powder are X: 0.367-0.424, Y: 0.571-0.545;

The weight ratio of red powder, green powder and yellow-green powder is:

Red powder: green powder: yellow-green powder = (0.010 ～ 0.035): (0.018 ～ 0.068): (0.071 ～ 0.253);

The concentration of the fluorescent film is 17% to 43%.

The thickness of the fluorescent film is preferably 0.2-0.4 mm. The particle size of the red powder, green powder, and yellow-green powder is less than 15 μm, and preferably 13 ± 2 μm.

Further, the red powder is preferably a nitride red phosphor, and more preferably, the nitride red phosphor includes CaSrAlSiN3 (1113 structure). The green powder is preferably a nitrogen oxide green phosphor. More preferably, the nitrogen oxide green phosphor includes BaSi2O2N2 (1222 structure). The yellow-green powder preferably includes Y3Al5Ga5O12 (that is, gallium-doped yttrium aluminum garnet). CaSrAlSiN3 nitride red phosphor, BaSi2O2N2 nitrogen oxide green phosphor, and Y3Al5Ga5O12 yellow-green phosphor can all achieve the color coordinates required by each phosphor, and have better luminous intensity and stability, which is very suitable for this application. In the phosphor of the embodiment of the invention. All kinds of the above phosphors are commercially available.

Example 1 as a fluorescent film:

A fluorescent film containing AB silica gel, CaSrAlSiN3 red phosphor (color coordinates, X: 0.660-0.716, Y: 0.286-0.340), BaSi2O2N2 green phosphor (color coordinates, X: 0.064-0.081, Y: 0.488-0.507) And Y3Al5Ga5O12 yellow-green phosphor (color coordinates, X: 0.367-0.424, Y: 0.545-0.571); among them, the weight ratio of CaSrAlSiN3 red phosphor, BaSi2O2N2 green phosphor and Y3Al5Ga5O12 yellow-green phosphor is (0.020-0.035): (0.018-0.030): (0.140-0.253), the mass percentage content of the three phosphors in the fluorescent film is 33-43%.

The fluorescent film is excited by blue light to obtain white light with a natural temperature of 2700K-3000K: in the spectrum, the relative spectrum in the 480-500nm band is greater than 0.30, and the relative spectrum in the 500-640nm band is greater than 0.70.

Example 2 as a fluorescent film

A fluorescent film containing AB silica gel, CaSrAlSiN3 red phosphor (color coordinates, X: 0.660-0.716, Y: 0.286-0.340), BaSi2O2N2 green phosphor (color coordinates, X: 0.064-0.081, Y: 0.488-0.507) And Y3Al5Ga5O12 yellow-green phosphor (color coordinate, X: 0.367-0.424, Y: 0.545-0.571); among them, the weight ratio of CaSrAlSiN3 red phosphor, BaSi2O2N2 green phosphor and Y3Al5Ga5O12 yellow-green phosphor is (0.010-0.022): (0.020-0.040): (0.080-0.140), the mass percentage content of the three phosphors in the fluorescent film is 25-35%.

The fluorescent film is excited by blue light to obtain white light with a natural temperature of 4000K-4200K: in the spectrum, the relative spectrum in the 480-500nm band is greater than 0.45, and the relative spectrum in the 500-640nm band is greater than 0.65.

Example 3 as a fluorescent film

A fluorescent film containing AB silica gel, CaSrAlSiN3 red phosphor (color coordinates, X: 0.660-0.716, Y: 0.286-0.340), BaSi2O2N2 green phosphor (color coordinates, X: 0.064-0.081, Y: 0.488-0.507) And Y3Al5Ga5O12 yellow-green phosphor (color coordinates, X: 0.367-0.424, Y: 0.545-0.571); among them, the weight ratio of CaSrAlSiN3 red phosphor, BaSi2O2N2 green phosphor and Y3Al5Ga5O12 yellow-green phosphor is (0.010-0.020): (0.030-0.068): (0.071-0.130), the mass percentage content of the three phosphors in the fluorescent film is 17-27%.

The fluorescent film is excited by blue light to obtain white light with a natural temperature of 5500K-6000K: in the spectrum, the relative spectrum in the 480-500nm band is greater than 0.40, and the relative spectrum in the 500-640nm band is greater than 0.60.

As a further improvement of this embodiment, in this embodiment, a blue light chip of 457.5-480nm or 457.5-460nm is used, in conjunction with the above-mentioned fluorescent film, in addition to obtaining the first near-natural light, it also consists in increasing the ratio of blue light. In many studies of near-natural LED technology, it is difficult to increase the green light ratio. The embodiment of the present invention breaks through the traditional technique of using a 450-455nm blue light chip to produce a white light source. A blue light chip of 457.5nm-480nm or 457.5-480nm is selected, and the above-mentioned fluorescent film is combined to obtain the first near-natural light. The relative spectral power has been significantly improved.

Referring to FIG. 2 and FIG. 8, FIG. 2 shows the white light spectrum in this embodiment. When a blue light chip with a wavelength of 457.5nm-460nm is used, the relative spectral power of the blue light has reached above 0.5, and when a blue light chip with a 457.5nm-480nm is used, Higher, when the 452.5-455nm blue light chip is used in Figure 8, the relative spectrum of blue light is only between 0.35 and 0.38.

Further, the first near-natural light can be obtained by using the above-mentioned fluorescent film and blue light chip. In combination with FIG. 2, it has the following parameters:

When the color temperature of the first near-natural light is 2700K-3000K, the relative spectral power of the 480-500nm band is greater than 0.30; the relative spectral power of the 500-640nm band is greater than 0.70; when the color temperature of the first near-natural light is 4000K-4200K, 480- The relative spectral power in the 500nm band is greater than 0.45; the relative spectral power in the 500-640nm band is greater than 0.65; when the color temperature of the first near-natural light is 5500K-6000K, the relative spectral power in the 480-500nm band is greater than 0.4; the relative power in the 500-640nm band The spectral power is greater than 0.60.

After the combination of the first near-natural light and the red light chip, the obtained quasi-natural light color temperature is 2500-6500K. In combination with FIG. 5 to FIG. 7, at any color temperature, the relative spectral power of red light is greater than 0.60; the relative spectral power of orange light is greater than 0.55; relative spectral power of yellow light is greater than 0.50; relative spectral power of green light is greater than 0.35; relative spectral power of cyan light is greater than 0.30; relative spectral power of blue light in the quasi-natural light is less than 0.75; relative spectral power of purple light is less than The relative spectral power of 0.10, 440nm blue light is less than 0.65. The above parameters are very close to natural light. On this basis, the quasi-natural light can also meet at least the following optical parameter requirements: color tolerance is less than 5, color rendering index Ra is greater than 90, may be greater than 97, color rendering index R9 is greater than 90, color rendering index R12 is greater than 80, and blue light color The ratio is less than 5.7%, and the color temperature is between 2700-6000K.

Regarding this quasi-natural light, it should be mentioned that according to the law of traditional white light illumination, the higher the white light color temperature, the higher the proportion of its short-wavelength components, and the higher the blue light, and the high blue light harms health is an unquestionable fact. Color temperature is conducive to improving recognition, and it is also recognized common sense to improve people's mental state. Therefore, conventional white light with high color temperature and blue light is bound to have advantages and disadvantages. In the optimization method of the embodiment of the present invention, for products with a high color temperature, the blue light color ratio is suppressed, and the 440nm blue light can also be suppressed, which can avoid the harm of blue light, which is beneficial to protecting vision and physical health; at the same time, Can get higher color temperature, and can meet the needs of efficient work and visual effects. Such a high color temperature and low blue light illumination light source is difficult to achieve in the prior art.

It should also be mentioned that, as shown in Figures 5 and 12, in the case of quasi-natural light, when the spectrum and optical parameters meet the requirements, the relative spectral power of 640-700nm red light is significantly improved, which is in the existing near-natural light. It is also difficult to achieve in the light source, mainly manifested in the enhancement of red light and the difficulty of taking into account the overall spectral shape and other light parameters. Traditional near-natural light sources tend to decrease significantly after 640nm. As shown in FIG. 12, the relative spectral power of 640-700 nm red light of a conventional white or near-natural light source is significantly reduced. As shown in FIG. 5 and FIG. 7, the relative spectral power of the red light in this band reaches above 0.6 in this embodiment. Among them, the relative spectral power of red light with a wavelength of 680 to 690 nm is greater than 0.80; the relative spectral power of red light with a wavelength of 622 to 680 nm is greater than 0.60.

And, after testing with different color temperature light sources, the relative spectral power of 640-700nm red light is greater than 0.70 when the color temperature of quasi-natural light is 2700K-3000K; the relative spectral power of 640-700nm red light when the color temperature of quasi-natural light is 4000K-4200K Greater than 0.60; when the color temperature of quasi-natural light is 5500K-6000K, the relative spectral power of 640-700nm red light is greater than 0.50.

It should also be mentioned that among the many near-natural light LED technologies, the green light ratio is difficult to improve, and it is more difficult to increase the green light when the blue light is lowered. At the same time, the R12 corresponding to the green light is also difficult to improve. . On the one hand, the embodiment of the present invention selects a blue light chip of 457.5nm-480nm by breaking the traditional convention (using a 455-480nm blue light chip), and is committed to the development of a fluorescent film. The two-pronged approach has significantly improved the relative spectral power of the blue light. . At the same time, the R12 was raised. As shown in FIG. 12, the relative spectral power of the cyan light in the conventional near-natural light is lower than 0.3. As shown in FIGS. 5 and 7, the relative spectral power of the cyan light in this embodiment is above 0.4, and the color rendering index R12 is above 80.

Moreover, after testing with different color temperature light sources, when the color temperature of quasi-natural light is 2700K-3000K, the relative spectral power of blue light in the 475-492nm band is greater than 0.30; when the color temperature of quasi-natural light is 4000K-4200K, the blue light in the 475-492nm band is relatively The spectral power is greater than 0.40; when the color temperature of quasi-natural light is 5500K-6000K, the relative spectral power of the cyan light in the 475-492nm band is greater than 0.50.

Further, when manufacturing a product, it is preferable to invert the blue light chip and the red light chip on the substrate, the fluorescent film has the same thickness, cover the blue light chip, and form a film on the chip through the device to ensure that the fluorescent film of different products is consistent. Good performance, which can avoid the problem of poor consistency caused by dispensing. At the same time, the color temperature of different products is in the same BIN position, and the color temperature consistency is good. It can be understood that the present invention is not limited to the use of a flip-chip, and a front-mounted chip structure and a fluorescent colloid may be used to form the first light-emitting body.

In summary, the method for optimizing the LED light source provided by the embodiments of the present invention has the following technical effects:

First, based on this optimization method, quasi-natural light with a spectrum closer to the natural light spectrum can be obtained, that is, the relative spectral power of each band is close to natural light. Compared with traditional white light illumination, the visual experience is more comfortable and is conducive to protecting the health of humans, animals and plants.

Secondly, the optimization method determines a white light emitter in advance to generate near-natural light. Based on this, a red light emitter is selected to supplement the light, and quasi-natural light that meets the requirements of the spectrum and light parameters is finally obtained. The traditional method has incomplete spectrum and it is difficult to take into account the problems of optical parameters.

Third, the suppression of harmful blue light to the human body is conducive to the protection of eyesight, especially for children and young children. It is also of great significance to protect and improve the vision; and it is also conducive to reducing the incidence of people who have been exposed to high blue light for a long time and protect the body. health.

Fourth, while achieving low blue light, it can maintain a high color temperature, and then maintain a high-definition, high-identification visual effect while maintaining a healthy level while maintaining an active and efficient working state, which is suitable for healthy public lighting.

Fifth, while reducing the blue light, the relative spectral power of the blue light can be increased, which solves the long-standing problems in the research of near-natural light, making the quasi-natural light closer to the real natural light, and the color rendering index is further improved.

Sixth, the relative spectral power of red light can be increased, making the spectrum closer to natural light, and 640-700nm red light has health care functions, which improves the health level of quasi-natural light illumination.

Seventh, based on the above-mentioned optimization method, according to the final determined luminous flux ratio, the appropriate first light emitter and second light emitter are selected, and the quasi-natural LED light source can be made with the substrate and circuit. The optimized results can be directly used for reference at the manufacturing end Data for easy chip selection and purchase.

Eighth, the quasi-natural light LED light source can select miniature white light emitters and red light emitters according to the final determined luminous flux ratio, and select as few red light emitters and white light emitters as possible to make a miniature single light source for Any combination of various lamps can ensure its better luminous effect, without dark spots, bright spots or uneven light mixing, and has strong adaptability.

The structure of the quasi-natural LED light source is further briefly described below.

Referring to FIG. 9, the quasi-natural LED light source includes a base layer 91, at least one group of light emitting components 92 disposed on the base layer 91, and a circuit 93 electrically connected to the light emitting component 92; each group of light emitting components 92 includes a white light emitting body 921 ( The first light emitter described above) and a red light emitter 922 (the second light emitter described above). The white light emitter 921 includes a blue light chip and an optical conversion film (fluorescent film or phosphorescent film). The red light emitter 922 includes a red light chip; white light. The white light emitted by the luminous body 921 is mixed with the red light emitted by the red light luminous body, and the red light is used to compensate the red light part of the white light that is missing from the natural spectrum to form quasi-natural light; the quasi-natural light has the spectrum involved in the optimization method of the present invention And optical parameters. Among them, at least meet the requirements of the relative spectral power of the red, green, and blue bands, and the requirements of color temperature, display index, and color tolerance.

Further, a reflective cup 94 is provided on the base layer 91. The base layer 91 and the light-emitting component 92 are disposed in the reflective cup 94. A circuit 93 is formed on the surface of the base layer 91, and is exposed on the bottom of the reflective cup 94, and a white light emitter. 921 is connected to the red light emitting body 922. Further, the fluorescent film can be uniformly formed by equipment in the manufacturing process, the product has good consistency, high reliability, and a small light source volume.

The quasi-natural-light LED light source uses miniature white light emitters and red light emitters. The amount of light radiation from the red light emitters is less than that of the white light emitters. You can choose as few red light emitters and white light emitters as possible to make a single piece. Light source, that is, a light source is provided with a group of light emitting components. Because the light source can directly emit quasi-natural light, and can be used in various lamps, any combination can ensure its better luminous effect and strong adaptability. Of course, multiple groups of light-emitting components can also be integrated into one light source. At this time, a better light output effect can still be guaranteed, and only the size is increased. Embodiments of the present invention are not limited to the number of light-emitting components included in a light source.

The above description is only the preferred embodiments of the present invention and is not intended to limit the present invention. Any modification, equivalent replacement, and improvement made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims

A method for optimizing an LED light source, comprising the following steps:

Selecting a first luminous body, which is used for emitting white light;

Optimizing the spectral distribution of the first luminous body and optimizing the white light to the first near-natural light;

Determining a to-be-optimized wavelength band of the first near-natural light according to the spectral distribution of the first near-natural light and the spectral distribution of the natural light;

Selecting a second light emitter according to the to-be-optimized band;

Lighting the first and second light emitters according to a preset luminous flux ratio of the first and second light emitters;

By adjusting the spectral distribution of the first luminous body and / or the second luminous body, a combined spectrum of the first luminous body and the second luminous body is optimized to obtain quasi-natural light.
The method for optimizing an LED light source according to claim 1, wherein the first luminous body comprises a blue light chip and an optical conversion film covering the blue light chip, and the optical conversion film comprises a colloid and is uniformly mixed in the light Optical conversion materials in colloids;

The step of optimizing the spectral distribution of the first luminous body and optimizing the white light to the first near-natural light includes:

The formula and / or concentration and / or thickness of the optical conversion film are adjusted so that the relative spectral power of the 480-500 nm band in the white light emitted by the first luminous body is greater than 0.30, and the relative spectral power of the 500-640 nm band is greater than 0.60.
The method for optimizing an LED light source according to claim 2, wherein in the step of optimizing the spectral distribution of the first light emitter and optimizing the white light to a first near-natural light, the first near When the color temperature of natural light is 2700K-3000K, the relative spectral power in the 480-500nm band is greater than 0.30; the relative spectral power in the 500-640nm band is greater than 0.70;

When the color temperature of the first near-natural light is 4000K-4200K, the relative spectral power in the 480-500nm band is greater than 0.45; the relative spectral power in the 500-640nm band is greater than 0.65;

When the color temperature of the first near-natural light is 5500K-6000K, the relative spectral power in the 480-500nm band is greater than 0.4; the relative spectral power in the 500-640nm band is greater than 0.60.
The method for optimizing an LED light source according to claim 3, wherein the optical conversion film is a fluorescent film or a phosphorescent film, and the optical conversion material is a fluorescent powder or a phosphorescent powder; and used to emit the first near-natural light The phosphor powder includes: red powder, green powder and yellow-green powder;

The color coordinates of the red powder are X: 0.660 to 0.716, and Y: 0.340 to 0.286;

The color coordinates of the green powder are X: 0.064 to 0.081, and Y: 0.488 to 0.507;

The color coordinates of the yellow-green powder are X: 0.367 to 0.424, and Y: 0.571 to 0.545;

The weight ratio of the red powder, green powder and yellow-green powder is:

Red powder: green powder: yellow-green powder = (0.010 ～ 0.035): (0.018 ～ 0.068): (0.071 ～ 0.253);

The concentration of the fluorescent film is 17% to 43%.
The method for optimizing an LED light source according to claim 4, wherein the thickness of the fluorescent film is 0.2-0.4 mm.
The method for optimizing an LED light source according to claim 4, wherein the particle size of the red powder, green powder, and yellow-green powder is less than 15 μm.
The method for optimizing an LED light source according to claim 3, wherein the wavelength band to be optimized is 640-700 nm; and the second luminous body is configured to emit red light at 640-700 nm.
The method for optimizing an LED light source according to claim 7, wherein the step of lighting the first light emitter and the second light emitter according to a preset luminous flux ratio of the first light emitter and the second light emitter comprises :

Selecting a ratio of the luminous flux of the first luminous body and the light radiating amount of the second luminous body to any ratio of 2-10: 1;

A corresponding number of the first and second light emitters are lit according to the selected ratio.
The method for optimizing an LED light source according to claim 8, wherein the first light emitting body and the second light emitting body are optimized by adjusting a spectral distribution of the first light emitting body and / or the second light emitting body. The step of obtaining quasi-natural light from the combined spectrum of the volume includes:

S1: Adjust the driving currents of the first and second luminous bodies, and monitor the combined spectrum in real time. When the relative spectral power of each band of the combined spectrum reaches a predetermined range, go to step S2, otherwise repeat Step S1;

S2: Detect the optical parameters of the combined spectrum. When the optical parameters reach a predetermined range, go to step S3, otherwise go back to step S1;

S3: Record the actual ratio of the light flux of the first light emitter and the light radiation amount of the second light emitter, the actual driving current of the first light emitter and the second light emitter, and corresponding optical parameters.
The method for optimizing an LED light source according to claim 9, wherein the actual ratio is 2-3: 1.
The method for optimizing an LED light source according to claim 9, characterized in that when the number of repetitions of step S1 reaches a predetermined number of times, step S4 is performed: adjusting the formula and / or concentration and / or thickness of the optical conversion film, Then go back to step S1;

Alternatively, step S5 is performed: adjusting the center wavelength of the second light-emitting body or increasing a third light-emitting body with a center wavelength different from the second light-emitting body, and then returning to step S1.
The method for optimizing an LED light source according to claim 11, wherein in step S4, the relative spectral power and / or color rendering index of each band is adjusted by adjusting the formula of the optical conversion film;

Adjusting a color rendering index and / or a color temperature by adjusting the concentration of the optical conversion film;

The color temperature is adjusted by adjusting the thickness of the optical conversion film.
The method for optimizing an LED light source according to claim 9, wherein the optical parameters include at least color temperature, color coordinates, color tolerance, color rendering index RA, color rendering index R9, color rendering index R12, and blue light color ratio .
The method for optimizing an LED light source according to claim 13, wherein the predetermined range of the color tolerance is less than 5, the predetermined range of the color rendering index RA is greater than 90, and the color rendering index R9 and the display The predetermined range of the color index R12 is more than 80, and the predetermined range of the blue light color ratio is less than 5.7%.
The method for optimizing an LED light source according to claim 13, wherein the relative spectral power of red light in the quasi-natural light is greater than 0.60; the relative spectral power of blue light is greater than 0.30; relative spectral power of blue light is less than 0.75.
The method for optimizing an LED light source according to claim 14, wherein the optical parameter further comprises a relative spectral power of 440 nm blue light.
The method for optimizing an LED light source according to claim 16, wherein the predetermined range of the relative spectral power of the 440nm blue light is less than 0.65.