A prediction method and system for fluorescent white LED spectral circadian rhythm factors

Abstract

The present invention relates to a method and system for predicting circadian rhythm factors of a fluorescent white LED. According to the correlation relationship between the circadian rhythm factors - blue light power - yellow light power, the blue light power - temperature - current model of the fluorescent white LED, the yellow light power - temperature - current model, the correlation relationship between the circadian rhythm factors - the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength, a circadian rhythm factor - temperature - current - excitation wavelength model is constructed; then, the operating data obtained during the operation of the fluorescent white LED is input into the circadian rhythm factor - temperature - current - excitation wavelength model to predict the circadian rhythm factors, and the circadian rhythm factors of the fluorescent white LED can be accurately predicted, so that the non-visual biological effects produced by the fluorescent white LED on the human body can be accurately quantitatively evaluated.

Description

Technical Field

[0001] The present invention relates to the technical field of LED spectrum research, and in particular to a method and system for predicting circadian action factors of the spectrum of fluorescent white LEDs. Background Art

[0002] Light-Emitting Diodes (LEDs) are gradually replacing traditional lighting methods and becoming a highly potential "green and healthy" lighting source due to their advantages such as high efficiency, low power consumption, adjustable chromaticity, and environmental friendliness. Light can affect the formation and release of melatonin, cortisol, and other hormones through intrinsically photosensitive retinal ganglion cells (ipRGCs), and thus participate in the regulation of human physiological functions. Therefore, for a "green and healthy" lighting source, the evaluation of lighting quality should not only focus on traditional visual performance but also pay attention to its non-visual biological effects on the human body. The circadian action factor (CAF) is a quantitative index reflecting the non-visual biological effects of a light source on the human body. However, existing evaluation and optimization technologies for fluorescent white LEDs only focus on the optical performance of white LEDs in providing visual information, such as energy efficiency, chromaticity quality, and reliability, and basically do not involve the impact of the white LED spectrum on human physiological functions, that is, the non-visual biological effects of the spectrum on the human body. Based on this, the present invention proposes a method and system for predicting circadian action factors of the spectrum of fluorescent white LEDs. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and system for predicting circadian action factors of the spectrum of fluorescent white LEDs. For fluorescent white LEDs, the effects of thermal effects, electrical driving conditions, and excitation characteristics of fluorescent materials on their spectral distributions are analyzed, and a prediction model of circadian action factor CAF - temperature - current - excitation wavelength is established based on the optical - electrical - thermal characteristics, which can be used to quantitatively evaluate the non-visual biological effects of fluorescent white LEDs on the human body and provide theoretical and technical references for the production and improvement of artificial light sources.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] A method for predicting circadian action factors of the spectrum of fluorescent white LEDs, comprising:

[0006] Constructing the correlation between circadian action factor - blue light power - yellow light power according to the blue - yellow light spectral distribution model of fluorescent white LEDs and the definition expression of circadian action factors;

[0007] Perform temperature and current control on the fluorescent white LED, and establish a blue light power-temperature-current model and a yellow light power-temperature-current model for the fluorescent white LED;

[0008] Determine the conversion efficiency between the ratios according to the power ratio of the yellow light spectrum and the blue light spectrum and the power ratio of the reflection spectrum and the excitation spectrum;

[0009] Construct the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum and the excitation spectrum according to the blue-yellow light spectrum distribution model of the fluorescent white LED and the conversion efficiency between the ratios;

[0010] Set a fixed value temperature for the fluorescent material and establish a model of the power ratio of the emission spectrum and the excitation spectrum-excitation wavelength;

[0011] Construct a circadian rhythm factor-temperature-current-excitation wavelength model according to the correlation relationship between the circadian rhythm factor-blue light power-yellow light power, the blue light power-temperature-current model of the fluorescent white LED, the yellow light power-temperature-current model, the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum and the excitation spectrum, and the model of the power ratio of the emission spectrum and the excitation spectrum-excitation wavelength;

[0012] Obtain the operating data during the operation of the fluorescent white LED, where the operating data includes temperature, the input drive current, and the peak wavelength of the blue light chip;

[0013] Predict the spectral circadian rhythm factor of the fluorescent white LED according to the circadian rhythm factor-temperature-current-excitation wavelength model and the operating data.

[0014] A system for predicting the spectral circadian rhythm factor of a fluorescent white LED, comprising:

[0015] A first correlation relationship acquisition module, configured to construct a correlation relationship between the circadian rhythm factor-blue light power-yellow light power according to the blue-yellow light spectrum distribution model of the fluorescent white LED and the circadian rhythm factor definition expression;

[0016] A power-temperature-current model construction module, configured to perform temperature and current control on the fluorescent white LED and establish a blue light power-temperature-current model and a yellow light power-temperature-current model for the fluorescent white LED;

[0017] A conversion efficiency calculation module between ratios, configured to determine the conversion efficiency between the ratios according to the power ratio of the yellow light spectrum and the blue light spectrum and the power ratio of the reflection spectrum and the excitation spectrum;

[0018] The second correlation relationship acquisition module is configured to construct a correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum according to the blue-yellow light spectral distribution model of the fluorescent white LED and the conversion efficiency between the ratios.

[0019] The power ratio-excitation wavelength model construction module is configured to set a fixed temperature for the fluorescent material and establish a model of the power ratio of the emission spectrum to the excitation spectrum-excitation wavelength.

[0020] The circadian rhythm factor-temperature-current-excitation wavelength model construction module is configured to construct a circadian rhythm factor-temperature-current-excitation wavelength model according to the correlation relationship between the circadian rhythm factor-blue light power-yellow light power, the blue light power-temperature-current model of the fluorescent white LED, the yellow light power-temperature-current model, the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum-excitation wavelength.

[0021] The data acquisition module is configured to acquire operation data during the operation of the fluorescent white LED, where the operation data includes temperature, the input drive current, and the peak wavelength of the blue light chip.

[0022] The prediction module is configured to predict the spectral circadian rhythm factor of the fluorescent white LED according to the circadian rhythm factor-temperature-current-excitation wavelength model and the operation data.

[0023] According to the specific embodiments provided by the present invention, the following technical effects are disclosed by the present invention:

[0024] The present invention provides a method and system for predicting the circadian rhythm factor of a fluorescent white LED spectrum. According to the correlation relationship between the circadian rhythm factor - blue light power - yellow light power, the blue light power - temperature - current model of the fluorescent white LED, the yellow light power - temperature - current model, the correlation relationship between the circadian rhythm factor - the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength, a circadian rhythm factor - temperature - current - excitation wavelength model is constructed. Then, the operating data obtained during the operation of the fluorescent white LED is input into the circadian rhythm factor - temperature - current - excitation wavelength model to predict the circadian rhythm factor. A blue - yellow dual - color spectrum model is used to describe the spectral distribution of the fluorescent white LED. The influence of the blue - light chip and the fluorescent material on the spectral distribution is comprehensively considered, including the thermal effect (temperature), the electrical driving condition (current), and the excitation characteristics of the fluorescent material (excitation wavelength). And in combination with the definition of the circadian rhythm factor CAF, a circadian rhythm factor CAF - temperature - current - excitation wavelength prediction model is established, which can predict the circadian rhythm factor of the fluorescent white LED, so as to know the non - visual biological effect of the white light spectrum of the fluorescent white LED on the human body, and thus know the influence of the LED spectrum on the human physiological function, so as to provide a reference for the design of the fluorescent white LED. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0026] Figure 1 It is a flowchart of a method for predicting the circadian rhythm factor of a fluorescent white LED spectrum provided in Embodiment 1 of the present invention;

[0027] Figure 2 It is the circadian rhythm factor CAF of the warm white LED emission spectrum at different temperatures and different currents provided in Embodiment 1 of the present invention;

[0028] Figure 3 It is the circadian rhythm factor CAF of the cold white LED emission spectrum at different temperatures and different currents provided in Embodiment 1 of the present invention;

[0029] Figure 4 It is the relationship between the blue light power, yellow light power and temperature in the white light spectrum emitted by the fluorescent white LED provided in Embodiment 1 of the present invention;

[0030] Figure 5Relationship between blue light power, yellow light power and current in the white light spectrum emitted by the fluorescent white LED provided in Embodiment 1 of the present invention;

[0031] Figure 6 For the fluorescent material provided in Embodiment 1 of the present invention (ratio P of emission spectrum power to excitation spectrum power opt,p / P opt,e ) and the relationship with the excitation wavelength;

[0032] Figure 7 Block diagram of a fluorescent white LED spectral circadian rhythm factor prediction system provided in Embodiment 2 of the present invention. Detailed implementation manners

[0033] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0034] The purpose of the present invention is to provide a method and system for predicting the circadian rhythm factors of the spectrum of a fluorescent white LED. For the fluorescent white LED, the effects of thermal effects, electrical driving conditions, and excitation characteristics of the fluorescent material on its spectral distribution are analyzed. Based on the optical-electrical-thermal characteristics, a circadian rhythm factor CAF-temperature-current-excitation wavelength prediction model is established, which can be used to quantitatively evaluate the non-visual biological effects of fluorescent white LEDs on the human body and provide theoretical and technical references for the production and improvement of artificial light sources.

[0035] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0036] Embodiment 1

[0037] Please refer to Figure 1 , this embodiment provides a method for predicting the circadian rhythm factors of the spectrum of a fluorescent white LED, including:

[0038] S1: Construct the correlation relationship between the circadian rhythm factor - blue light power - yellow light power according to the blue-yellow light spectrum distribution model and the definition expression of the circadian rhythm factor of the fluorescent white LED;

[0039] Specifically, the expression of the blue-yellow light spectrum distribution model of the fluorescent white LED is:

[0040]

[0041] wherein, P(λ) is the spectral power distribution of the light source, λ is the spectral wavelength, P opt,b(w) is the blue light power in the white light spectrum, λ peak,b is the peak wavelength of the blue light spectrum, σ b is the full width at half maximum (FWHM) rating coefficient of the blue light spectrum; P opt,y(w) is the yellow light power in the white light spectrum, λ peak,y is the peak wavelength of the yellow light spectrum, σ y is the full width at half maximum (FWHM) rating coefficient of the yellow light spectrum.

[0042] The expression of the correlation relationship between the circadian rhythm factor - blue light power - yellow light power is:

[0043]

[0044] wherein, CAF is the circadian rhythm factor, C(λ) is the spectral physiological response curve, and V(λ) is the spectral luminous efficiency function under photopic vision.

[0045] S2: Control the temperature and current of the fluorescent white LED to establish the blue light power - temperature - current model and the yellow light power - temperature - current model of the fluorescent white LED;

[0046] Specifically, the expressions of the blue light power - temperature - current model and the yellow light power - temperature - current model of the fluorescent white LED are:

[0047]

[0048] wherein, T represents temperature, and I represents current; k1, a1, and b1 are the parameters of the blue light power - temperature - current model, and k1 characterizes the variation relationship of the blue light power with temperature and current; k2, a2, and b2 are the parameters of the yellow light power - temperature - current model, and k2 characterizes the variation relationship of the yellow light power with temperature and current.

[0049] S3: Determine the conversion efficiency between the ratios according to the power ratio of the yellow light spectrum and the blue light spectrum and the power ratio of the reflection spectrum and the excitation spectrum;

[0050] Specifically, determine the power ratio of the yellow light spectrum to the blue light spectrum according to the white light spectrum emitted by the fluorescent white LED; determine the power ratio of the emission spectrum to the excitation spectrum according to the excitation test of the fluorescent material, and then determine the conversion efficiency between the two ratios.

[0051] S4: Construct the correlation relationship between the circadian rhythm factor - the power ratio of the emission spectrum and the excitation spectrum according to the blue - yellow light spectrum distribution model of the fluorescent white LED and the conversion efficiency between the ratios;

[0052] Specifically, the expression for the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum is as follows:

[0053]

[0054] Among them,

[0055] P opt,p is the optical power of the emission spectrum of the fluorescent material, and P opt,e is the optical power of the excitation spectrum of the fluorescent material, and γ is the conversion efficiency between the ratios.

[0056] S5: Set a fixed temperature for the fluorescent material and establish a model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength; that is, for the fluorescent material, at a fixed temperature, establish the relationship between the spectral characteristics of the phosphor and the excitation wavelength;

[0057] Specifically, the expression for the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength is as follows:

[0058]

[0059] Among them, T0 is the fixed temperature, and λ e is the excitation wavelength; f1, f2, and f3 are the model parameters of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength, which are related to the excitation characteristics of the fluorescent material.

[0060] S6: Construct a circadian rhythm factor - temperature - current - excitation wavelength model based on the correlation relationship between the circadian rhythm factor - blue light power - yellow light power, the blue light power - temperature - current model of the fluorescent white LED, the yellow light power - temperature - current model, the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength;

[0061] Among them, step S6 specifically includes:

[0062] Based on the correlation relationship between the circadian rhythm factor - blue light power - yellow light power, the blue light power - temperature - current model, and the yellow light power - temperature - current model, establish a circadian rhythm factor - temperature - current model;

[0063] Specifically, the expression for the circadian rhythm factor - temperature - current model is as follows:

[0064]

[0065] Among them, T is the temperature, I is the current, and λ e,0is a fixed excitation wavelength; K1, A1, A2, B1, and B2 are circadian rhythm factor-temperature-current model parameters, which are related to the electro-thermal characteristics of the white light spectrum.

[0066] According to the correlation between the circadian rhythm factor-emission spectrum and excitation spectrum ratio and the emission spectrum and excitation spectrum-excitation wavelength model, establish a circadian rhythm factor-excitation wavelength model;

[0067] Specifically, the expression of the circadian rhythm factor-excitation wavelength model is:

[0068]

[0069] Among them, T0 is a fixed temperature, I0 is a fixed current, and λ e is the excitation wavelength; K2, F1, F2, F3, and F4 are circadian rhythm factor-excitation wavelength model parameters, which are related to the white light spectrum characteristics and the excitation characteristics of the fluorescent material.

[0070] According to the circadian rhythm factor-temperature-current model and the circadian rhythm factor-excitation wavelength model, establish a circadian rhythm factor-temperature-current-excitation wavelength model.

[0071] Specifically, the expression of the circadian rhythm factor-temperature-current-excitation wavelength model is:

[0072]

[0073] Among them, T represents temperature, I represents current, and λ e represents the excitation wavelength; K, A1, A2, B1, B2, F1, F2, F3, and F4 are circadian rhythm factor-temperature-current-excitation wavelength model parameters, which are related to the white light spectrum characteristics and the excitation characteristics of the fluorescent material, and K characterizes the change relationship of the circadian rhythm factor of the white light spectrum following temperature, drive current, and phosphor excitation wavelength.

[0074] S7: Obtain the operating data during the operation of the fluorescent white LED, and the operating data includes temperature, input drive current, and the peak wavelength of the blue chip;

[0075] S8: Predict the spectral circadian rhythm factor of the fluorescent white LED according to the circadian rhythm factor-temperature-current-excitation wavelength model and the operating data.

[0076] This embodiment gives verification sample 1 warm white LED and verification sample 2 cold white LED, and judges the relative error predicted by the circadian rhythm factor-temperature-current-excitation wavelength model based on the two samples, where Table 1 shows the parameter and coefficient values of the verification sample model.

[0077] Model parameters and coefficient values in the verification samples in Table 1

[0078]

[0079]

[0080] Figure 2 The circadian action factor CAF of the emission spectrum of a warm white LED (verification sample 1) at different temperatures and different currents is shown. In the test data of the warm white LED, 1) when the driving current is 60 mA and the temperature is 25 °C, the predicted value of the circadian action factor CAF is 0.7838, the measured value is 0.7815, and the relative error is 0.32%; 2) when the driving current is 60 mA and the temperature is 85 °C, the predicted value of the circadian action factor CAF is 0.8223, the measured value is 0.8199, and the relative error is 0.18%; 3) when the driving current is 200 mA and the temperature is 25 °C, the predicted value of the circadian action factor CAF is 0.8066, the measured value is 0.8115, and the relative error is 0.56%; 4) when the driving current is 200 mA and the temperature is 85 °C, the predicted value of the circadian action factor CAF is 0.8462, the measured value is 0.8487, and the relative error is 0.13%.

[0081] Figure 3 The circadian action factor CAF of the emission spectrum of a cold white LED (verification sample 2) at different temperatures and different currents is shown. In the test data of the cold white LED, 1) when the driving current is 100 mA and the temperature is 25 °C, the predicted value of the circadian action factor CAF is 0.5685, the measured value is 0.5783, and the relative error is 1.72%; 2) when the driving current is 100 mA and the temperature is 95 °C, the predicted value of the circadian action factor CAF is 0.6088, the measured value is 0.6234, and the relative error is 2.33%; 3) when the driving current is 500 mA and the temperature is 25 °C, the predicted value of the circadian action factor CAF is 0.6259, the measured value is 0.6305, and the relative error is 0.73%; 4) when the driving current is 50 mA and the temperature is 95 °C, the predicted value of the circadian action factor CAF is 0.6703, the measured value is 0.6734, and the relative error is 0.46%.

[0082] To understand the technical solution of this embodiment more clearly, the construction process of the circadian action factor - temperature - current - excitation wavelength model will be introduced in detail below:

[0083] The non-visual parameter that measures the health of a light source - the circadian action factor (CAF) is defined as follows

[0084]

[0085] Among them, P(λ) is the spectral power distribution of the light source, C(λ) is the spectral physiological response curve, and V(λ) is the spectral luminous efficiency function under photopic vision.

[0086] The white light emitted by the fluorescent white LED can theoretically be regarded as a mixture of a blue light spectrum and a yellow light spectrum, and its spectral distribution can be described as

[0087]

[0088] Among them, p opt,b(w) is the blue light power in the white light spectrum, λ peak,b is the peak wavelength of the blue light spectrum, σ b is the full-width at half-maximum (FWHM) rating coefficient of the blue light spectrum; P opt,y(w) is the yellow light power in the white light spectrum, λ peak,y is the peak wavelength of the yellow light spectrum, σ y is the full-width at half-maximum (FWHM) rating coefficient of the yellow light spectrum. Therefore, the circadian rhythm factor of the fluorescent white LED is

[0089]

[0090] Within the actual working range, the relationships between the blue light power, yellow light power in the white light spectrum and temperature, current can be described by the following functional forms:

[0091]

[0092] Among them, T represents temperature, I represents current, which are variables; k1, a1, b1 are the model parameters of blue light power - temperature - current, which are constants; k2, a2, b2 are the model parameters of yellow light power - temperature - current, which are constants. Figure 4 shows the relationships between the blue light power, yellow light power in the white light spectrum emitted by the fluorescent white LED and temperature, Figure 5 shows the relationships between the blue light power, yellow light power in the white light spectrum emitted by the fluorescent white LED and current.

[0093] Within the actual working range, the changes in the peak wavelengths and their full-width at half-maximum (FWHM) rating coefficients of the blue light spectrum and yellow light spectrum in the white LED spectrum are negligible. At this time, record

[0094]

[0095] Furthermore, the following transformation can be made to Equation (3)

[0096]

[0097] Because C 11 、C 12 、V 11 、V12 They are all constants. When the temperature is a fixed value, both the numerator and denominator of Equation (6) are linearly related to the current I; when the current is a fixed value, the numerator and denominator of Equation (6) are linearly related to the temperature T. Therefore, at a certain excitation wavelength, Equation (6) can be further written as

[0098]

[0099] where T represents temperature and I represents current; K1, A1, A2, B1, and B2 are the white light spectrum circadian rhythm factor-temperature-current model parameters and are constant values.

[0100] For the fluorescent material, the optical power of its emission spectrum is P opt,p , and the optical power of its excitation spectrum is P opt,e . When the temperature is constant, the power ratio P opt,p / P opt,e of its emission spectrum to the excitation spectrum and the excitation wavelength λ e have the following functional relationship:

[0101]

[0102] where f1, f2, and f3 are the correlation coefficients between the optical characteristics of the fluorescent material and the excitation wavelength and are constant values. Among them, Figure 6 shows the relationship between (the power ratio P opt,p / P opt,e ) of the emission spectrum to the excitation spectrum in the fluorescent material and the excitation wavelength;

[0103] For the encapsulated fluorescent white LED, the power ratio of the yellow light spectrum to the blue light spectrum in its white light spectrum is intrinsically related to the power ratio of the emission spectrum to the excitation spectrum in the excitation characteristics of the corresponding phosphor material, as follows

[0104]

[0105] where P opt,p is the optical power of the emission spectrum of the fluorescent material, P opt,e is the optical power of the excitation spectrum of the fluorescent material, P opt,b(w) is the blue light power in the white light spectrum of the white LED, P opt,y(w) is the yellow light power in the white light spectrum of the white LED, and γ is the conversion coefficient between the two ratios.

[0106] From Equation (9), we can obtain

[0107]

[0108] Similarly, ignoring the slight changes in the peak wavelengths and half-width rating coefficients of the blue and yellow light spectra in the white light LED output spectrum, the white light spectrum rhythm factor can be transformed as follows

[0109]

[0110] Substituting equation (8) into equation (11), we have

[0111]

[0112] Among them, C 11 , C 12 、V 11 、V 12 , f1, f2, and f3 are as described above; K2, F1, F2, F3, and F4 are parameters of the white light spectrum rhythmic factor-excitation wavelength model and are constants.

[0113] Combining equations (7) and (12), a prediction model of the fluorescence white light LED spectrum circadian rhythm factor CAF and temperature, driving current and phosphor excitation wavelength can be established:

[0114]

[0115] Among them, except for the variables T, I, λ e In addition, all other parameters are constant coefficients, which are related to the white light spectrum characteristics and the excitation characteristics of the fluorescent material; in particular, K characterizes the relationship between the white light spectrum rhythm factor and the change of temperature, driving current and phosphor excitation wavelength.

[0116] In this embodiment, the fluorescent white light LED circadian rhythm factor CAF-temperature-current-excitation wavelength prediction model of the present invention establishes a connection between the emission spectrum of the fluorescent white light LED and its optical, electrical and thermal characteristics. When the temperature, driving current and peak wavelength of the blue light chip during the operation of the fluorescent white light LED are obtained, the circadian rhythm factor can be predicted by the model to quantitatively evaluate the non-visual biological effects of the fluorescent white light LED emission spectrum on the human body.

[0117] The purpose of the present invention is to provide a method for predicting the circadian factor of a fluorescent white light LED, so as to solve the problem that the circadian factor of a blue light chip cannot be determined before it is packaged with a fluorescent material, resulting in the non-visual biological effect of the emission spectrum on the human body after packaging not meeting specific lighting requirements or not meeting the requirements of a healthy lighting source; at the same time, for packaged fluorescent white light LEDs, the size of the spectral rhythm factor can be changed according to the prediction model by adjusting the driving current and improving thermal management measures, thereby improving the non-visual biological effects on the human body.

[0118] Example 2

[0119] As Figure 7 shown, this embodiment provides a fluorescence-type white LED spectral circadian rhythm factor prediction system, including:

[0120] The first correlation relationship acquisition module M1 is used to construct the correlation relationship of circadian rhythm factor - blue light power - yellow light power according to the blue-yellow light spectral distribution model of the fluorescence-type white LED and the circadian rhythm factor definition expression;

[0121] The power-temperature-current model construction module M2 is used to control the temperature and current of the fluorescence-type white LED, and establish the blue light power-temperature-current model and the yellow light power-temperature-current model of the fluorescence-type white LED;

[0122] The conversion efficiency calculation module M3 between ratios is used to determine the conversion efficiency between ratios according to the power ratio of the yellow light spectrum and the blue light spectrum and the power ratio of the reflection spectrum and the excitation spectrum;

[0123] The second correlation relationship acquisition module M4 is used to construct the correlation relationship of circadian rhythm factor - power ratio of emission spectrum to excitation spectrum according to the blue-yellow light spectral distribution model of the fluorescence-type white LED and the conversion efficiency between ratios;

[0124] The power ratio-excitation wavelength model construction module M5 is used to set a fixed value temperature for the fluorescent material and establish a model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength;

[0125] The circadian rhythm factor-temperature-current-excitation wavelength model construction module M6 is used to construct the circadian rhythm factor-temperature-current-excitation wavelength model according to the correlation relationship of circadian rhythm factor - blue light power - yellow light power, the blue light power-temperature-current model of the fluorescence-type white LED, the yellow light power-temperature-current model, the correlation relationship of circadian rhythm factor - power ratio of emission spectrum to excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength;

[0126] The data acquisition module M7 is used to acquire the operating data during the operation of the fluorescence-type white LED, and the operating data includes temperature, input drive current, and the peak wavelength of the blue light chip;

[0127] The prediction module M8 is used to predict the spectral circadian rhythm factor of the fluorescence-type white LED according to the circadian rhythm factor-temperature-current-excitation wavelength model and the operating data.

[0128] For the system disclosed in the embodiments, since it corresponds to the method disclosed in the embodiments, the description is relatively simple. For related parts, please refer to the description in the method section.

[0129] In this article, specific examples are used to elaborate on the principles and implementation manners of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for those of ordinary skill in the art, according to the idea of the present invention, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation on the present invention.

Claims

1. A method for predicting circadian rhythm factors of a fluorescent white LED spectrum, characterized in that, Including: Construct the correlation relationship among the circadian rhythm factor, blue light power, and yellow light power according to the blue-yellow light spectrum distribution model of the fluorescent white LED and the definition expression of the circadian rhythm factor; Control the temperature and current of the fluorescent white LED, and establish the blue light power-temperature-current model and yellow light power-temperature-current model of the fluorescent white LED; Determine the conversion efficiency between the ratios according to the power ratio of the yellow light spectrum and the blue light spectrum and the power ratio of the reflection spectrum and the excitation spectrum; Construct the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum according to the blue-yellow light spectrum distribution model of the fluorescent white LED and the conversion efficiency between the ratios; Set a fixed temperature for the fluorescent material and establish a model of the power ratio of the emission spectrum to the excitation spectrum-excitation wavelength; Construct a circadian rhythm factor-temperature-current-excitation wavelength model according to the correlation relationship among the circadian rhythm factor, blue light power, and yellow light power, the blue light power-temperature-current model of the fluorescent white LED, the yellow light power-temperature-current model of the fluorescent white LED, the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum-excitation wavelength; Obtain the operating data during the operation of the fluorescent white LED, and the operating data includes temperature, input drive current, and the peak wavelength of the blue light chip; Predict the spectral circadian rhythm factor of the fluorescent white LED according to the circadian rhythm factor-temperature-current-excitation wavelength model and the operating data.

2. The method according to claim 1, characterized in that The construction of the circadian rhythm factor-temperature-current-excitation wavelength model according to the correlation relationship among the circadian rhythm factor, blue light power, and yellow light power, the blue light power-temperature-current model of the fluorescent white LED, the yellow light power-temperature-current model of the fluorescent white LED, the correlation relationship between the circadian rhythm factor and the ratio of the emission spectrum to the excitation spectrum, and the model of the ratio of the emission spectrum to the excitation spectrum-excitation wavelength specifically includes: Establish a circadian rhythm factor-temperature-current model according to the correlation relationship among the circadian rhythm factor, blue light power, and yellow light power, the blue light power-temperature-current model, and the yellow light power-temperature-current model; Establish a circadian rhythm factor-excitation wavelength model according to the correlation relationship between the circadian rhythm factor and the ratio of the emission spectrum to the excitation spectrum and the model of the ratio of the emission spectrum to the excitation spectrum-excitation wavelength; Establish a circadian rhythm factor-temperature-current-excitation wavelength model according to the circadian rhythm factor-temperature-current model and the circadian rhythm factor-excitation wavelength model.

3. The method according to claim 2, characterized in that, The expression of the blue-yellow light spectrum distribution model of the fluorescent white LED is: Among them, P(λ) is the spectral power distribution of the light source, λ is the spectral wavelength, P opt,b(w) is the blue light power in the white light spectrum, λ peak,b is the peak wavelength of the blue light spectrum, σ b is the full width at half maximum (FWHM) rated coefficient of the blue light spectrum; P opt,y(w) is the yellow light power in the white light spectrum, λ peak,y is the peak wavelength of the yellow light spectrum, σ y is the full width at half maximum (FWHM) rated coefficient of the yellow light spectrum. The expression of the correlation relationship among the circadian rhythm factor, blue light power, and yellow light power is: Wherein, CAF is the circadian rhythm factor, C(λ) is the spectral physiological response curve, and V(λ) is the spectral luminous efficiency function under photopic vision.

4. The method according to claim 3, characterized in that The expressions of the blue light power - temperature - current model and the yellow light power - temperature - current model of the fluorescent white LED are as follows: Where, T represents temperature, and I represents current; k1, a1, b1 are the parameters of the blue light power - temperature - current model, and k1 characterizes the variation relationship of the blue light power with temperature and current; k2, a2, b2 are the parameters of the yellow light power - temperature - current model, and k2 characterizes the variation relationship of the yellow light power with temperature and current.

5. The method according to claim 4, characterized in that The expression of the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum is as follows: Among them, P opt,p is the optical power of the emission spectrum of the fluorescent material, P opt,e is the optical power of the excitation spectrum of the fluorescent material, and γ is the conversion efficiency between the ratios.

6. The method according to claim 5, wherein The expression of the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength is as follows: where, T0 is a fixed temperature, and λ e is the excitation wavelength; f1, f2, and f3 are the power ratio-excitation wavelength model parameters of the emission spectrum and the excitation spectrum, which are related to the excitation characteristics of the fluorescent material.

7. The method according to claim 6, wherein The expression of the circadian rhythm factor - temperature - current model is as follows: where T is temperature, I is current, and λ e,0 is a fixed excitation wavelength; K1, A1, A2, B1, and B2 are circadian rhythm factor-temperature-current model parameters, which are related to the electro-thermal characteristics of the white light spectrum.

8. The method according to claim 7, wherein The expression of the circadian rhythm factor - excitation wavelength model is as follows: Among them, T0 is a fixed temperature, I0 is a fixed current, and λ e is the excitation wavelength; K2, F1, F2, F3, and F4 are circadian rhythm factor-excitation wavelength model parameters, which are related to the white light spectral characteristics and the excitation characteristics of the fluorescent material.

9. The method according to claim 8, wherein The expression of the circadian rhythm factor - temperature - current - excitation wavelength model is as follows: Among them, T represents temperature, I represents current, and λ e represents the excitation wavelength; K, A1, A2, B1, B2, F1, F2, F3, F4 are circadian rhythm factor-temperature-current-excitation wavelength model parameters, which are related to the white light spectrum characteristics and the excitation characteristics of the fluorescent material, and K characterizes the variation relationship of the circadian rhythm factor of the white light spectrum with temperature, driving current, and the excitation wavelength of the phosphor.

10. A fluorescence-based white LED spectral circadian rhythm factor prediction system based on the method according to any one of claims 1 to 9, characterized in that, Including: The first correlation relationship acquisition module is used to construct the correlation relationship between the circadian rhythm factor - blue light power - yellow light power according to the blue - yellow light spectrum distribution model of the fluorescent white LED and the definition expression of the circadian rhythm factor; The power - temperature - current model construction module is used to control the temperature and current of the fluorescent white LED and establish the blue light power - temperature - current model and the yellow light power - temperature - current model of the fluorescent white LED; The ratio conversion efficiency calculation module is used to determine the ratio conversion efficiency according to the power ratio of the yellow light spectrum to the blue light spectrum and the power ratio of the reflection spectrum to the excitation spectrum; The second correlation relationship acquisition module is used to construct the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum according to the blue - yellow light spectrum distribution model of the fluorescent white LED and the ratio conversion efficiency; The power ratio - excitation wavelength model construction module is used to set a fixed temperature for the fluorescent material and establish the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength; The circadian rhythm factor - temperature - current - excitation wavelength model construction module is used to construct the circadian rhythm factor - temperature - current - excitation wavelength model according to the correlation relationship between the circadian rhythm factor - blue light power - yellow light power, the blue light power - temperature - current model of the fluorescent white LED, the yellow light power - temperature - current model, the correlation relationship between the circadian rhythm factor and the power ratio of the emission spectrum to the excitation spectrum, and the model of the power ratio of the emission spectrum to the excitation spectrum - excitation wavelength; The data acquisition module is used to acquire the operation data during the operation of the fluorescent white LED, and the operation data includes temperature, the input driving current, and the peak wavelength of the blue light chip; The prediction module is used to predict the spectral circadian rhythm factor of the fluorescent white LED according to the circadian rhythm factor - temperature - current - excitation wavelength model and the operation data.

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