A method for realizing LED backlight source that highlights main body color

Abstract

The invention discloses a method for realizing an LED backlight source for highlighting a main color, comprising the following steps: S1: an optical detection device transmits detection information to an algorithm module; step S2: the algorithm module determines the main color hue area information in a scene through the detection information; S3: extracting a main color sample of the main color according to the main color hue area information; S4: respectively calculating the first color coordinate of the main color sample under a reference light source and the second color coordinate of the main color sample under a target light source according to the main color sample; S5: calculating the main color saturation vector according to the first and second color coordinates; S6: evaluating whether the main color saturation vector direction is in a color enhancement direction and evaluating whether the saturation vectors of other hues are in a color weakening direction; S7: if the main color saturation vector direction is in a color enhancement direction, outputting the current main target light source driving information; S8: if the saturation vector direction of other hues is in a color weakening direction, outputting the other hue sub-target light source driving information; and S9: driving a device to generate a total target spectrum according to the main and other hue sub-target light source driving information.

Description

Technical Field

[0001] The invention relates to the field of spectrum, and in particular to a method for realizing an LED backlight source that highlights a main body color. Background Art

[0002] Compared with natural light, ordinary white light sources such as fluorescent lamps and light-emitting diode (LED) light sources often enhance or weaken the colors of various objects simultaneously. In the same lighting scene, various colors either become more vivid or dimmer at the same time, and it is impossible to highlight a certain color. However, in film and television lighting, artwork lighting and special commercial lighting scenes, users often need to highlight one or two colors in the scene, that is, the main color, such as enhancing red while keeping other colors unchanged, enhancing green and blue while weakening other colors, etc.

[0003] The color of an object is determined by the reflection spectrum of the object and the spectrum of the illumination source. Ordinary white light sources such as fluorescent lamps and LEDs have spectral energy distribution in the red, green and blue bands, which makes the colors of objects of different colors appear to have similar characteristics: compared with the color of objects under daylight, the various colors of objects under ordinary light sources are either strengthened or weakened at the same time, such as Figure 1 As shown: Figure 1 The LED white light source, the illuminated monochromatic object (Monsel 5P 5 / 10 color card) and the spectrum of reflected light are shown. It can be seen that when the LED white light is irradiated on the color card, part of the light in a certain band (500nm to 600nm in the figure) is partially absorbed, while the light in other bands is reflected; the reflected light spectrum is different from the incident light. Compared with the true color of the object, the blue energy of the reflected light (400nm to 500nm band) accounts for a larger proportion, and the overall color of the object is enhanced. The above is an analysis of the spectral changes of a color sample. There are often multiple colors in a lighting scene. In order to highlight and enhance specific colors, there are mainly two existing solutions:

[0004] 1. Use special light sources to match the main color, such as some fluorescent lamps that enhance red and green while weakening other colors.

[0005] 2. Instead of using white light, use a reddish light source to enhance red, or a greenish light source to enhance green. For example, fresh food markets often use red lampshades and use reddish light to illuminate meat to make it look more colorful.

[0006] However, the existing light source matching solutions have the following disadvantages:

[0007] 1. Multiple attempts are required: Matching different main colors requires different light sources. Since the luminous spectrum of various white light sources is not designed to highlight a certain main color, but to simulate the color rendering effect of daylight as much as possible, it is designed according to a certain color rendering index (CRI). This makes it necessary to match different light sources multiple times to highlight a specific main color. Therefore, it cannot meet the needs of real-time adjustment and has low feasibility.

[0008] 2. The main color enhancement effect is not good: the white light source has a limited degree of enhancement on specific colors, and inevitably enhances other non-main colors at the same time, which makes the main color cannot be effectively highlighted. Figure 2 The spectrum of the F32T8 fluorescent lamp tube is shown. Figure 3 The IES-TM30 (see reference David, Aurelian et al., "Development of the IES Method for Evaluating Light Source Color Reproduction", Optics Express 23.12 (2015)) is used to evaluate the color enhancement / reduction percentage of 16 average color samples. Number 1 represents the red color sample, number 6 represents the green color sample, number 12 represents the blue sample, and the other numbers represent the intermediate colors between the three. It can be seen that although this lamp tube enhances the yellow-green color (corresponding to numbers 4-7) and also weakens the red and blue-green (1-2, 8-11), the maximum difference between the enhancement percentage and the reduction percentage is only 20% (color sample No. 5 vs. color sample No. 10). This is not obvious in human eye recognition and camera recognition.

[0009] Disadvantages of existing non-white light source matching solutions:

[0010] 1. The prominence of the subject is uncontrollable: Wrapping colored filter paper outside the white light or using a colored light source can enhance the corresponding color, but the degree of color enhancement is uncontrollable. As a result, the color of the object is over-enhanced, exceeding the comfortable range of human eye recognition. An example is using a reddish light source to illuminate meat. Although the meat is bright in color, customers feel that the color is fake.

[0011] 2. Different colored filter papers or colored light sources need to be matched to different main colors, which is not feasible.

[0012] 3. Colored light sources affect the comfort of the human eye and also affect the white balance settings of cameras, camcorders and other equipment, making it impossible for the color effect of objects to be truly captured by the human eye or electronic equipment. Summary of the invention

[0013] In order to solve the deficiencies in the prior art, the present invention provides a method for realizing an LED backlight source that highlights the main color.

[0014] The technical solution of the present invention is: a method for realizing an LED backlight source that highlights the main color, the steps are as follows:

[0015] Step S1: The optical detection device transmits the detection information to the algorithm module;

[0016] Step S2: the algorithm module determines the main color tone area information in the scene through the detection information;

[0017] Step S3: extracting the main color sample of the main color according to the main color hue area information;

[0018] Step S4: Calculate the first color coordinates of the master color sample under the reference light source and the second color coordinates of the master color sample under the target light source respectively according to the master color sample;

[0019] Step S5: Calculate the primary color saturation vector of the primary color sample according to the first and second color coordinates;

[0020] Step S6: evaluating whether the direction of the main color saturation vector is toward the color enhancement direction and evaluating whether the saturation vectors of other hues are toward the color weakening direction;

[0021] Step S7: if the direction of the main color saturation vector is toward the color enhancement direction, output the current main target light source driving information;

[0022] Step S8: if the saturation vector direction of other hues is toward the color weakening direction; output the driving information of the sub-target light sources of other hues;

[0023] Step S9: driving the device to generate a total target spectrum according to the main and other color tone sub-target light source driving information.

[0024] Preferred technical solution: In step S1, the detection information includes spectrum or RGB color information.

[0025] Preferred technical solution: The reference light source in step S4 is obtained by the algorithm module based on the detection information in step S1.

[0026] Preferred technical solution: Step S6: Evaluate whether the direction of the main color saturation vector is in the direction of color enhancement; if it is not in the direction of color enhancement, obtain the main difference by subtracting the size of the current main color saturation vector from the main standard color wavelength range value.

[0027] The preferred technical solution is: according to the main difference, by optimizing the iteration parameters, the secondary driving information of the secondary target light source after the next iteration is obtained.

[0028] Preferred technical solution: According to the secondary driving information, it is first necessary to determine whether the background color sample is white light, and the steps are as follows:

[0029] Step S31: Read whether the background color is white light according to the information in the background color database;

[0030] Step S32: If the background color is white light, execute step S4;

[0031] Step S33: If the background color is not white light, execute step S31.

[0032] Preferred technical solution: In step S6, it is evaluated whether the saturation vectors of other hues are in the direction of color attenuation; if in the direction of color attenuation, a secondary difference is obtained by subtracting the current size of the saturation vector of other colors from the wavelength range value of the other color standard color, and according to the secondary difference, the driving information of the secondary target light source of the next iteration is obtained by optimizing the iteration parameters, and step S4 is continued to be executed to calculate the second secondary color coordinates under the target light source.

[0033] Preferred technical solution: The color reference in color attenuation and color enhancement is a standard color wavelength range value based on the main color or other colors, the color attenuation direction refers to the saturation vector of the hue within the standard color wavelength range value, and the color enhancement direction refers to the saturation vector of the hue outside the standard color wavelength range value.

[0034] The beneficial effects achieved by the present invention are as follows: the present invention provides a lighting method for highlighting the main color, which can automatically identify the main color in the scene, adjust the luminous spectrum in real time, enhance the main color, and weaken other colors, so as to achieve the purpose of highlighting the main color. The present invention also provides a lighting device corresponding to this method to realize the above process.

[0035] 1. The present invention solves the problem that the prominence degree of the subject is uncontrollable or low, and the prominence degree of the subject color can be quantitatively set in the system.

[0036] 2. The present invention solves the problem of subject color matching. The subject color of the scene can be manually set or automatically detected, and the system automatically adjusts the luminous spectrum to enhance the subject color. The method and system can use the same light source to meet the different subject color requirements of different scenes, without matching multiple light sources, and has strong feasibility.

[0037] 3. The present invention solves the problem of non-white light. While highlighting the main color, the present invention ensures that the light-emitting device still emits white light, does not affect the white balance judgment of the human eye and electronic equipment, and truly displays the color of the object. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is the spectrum of the object illuminated by the LED white light source of the present invention (Monsel 5P 5 / 10 color card) and the reflected light.

[0039] Figure 2 is the spectrum of the F32T8 fluorescent lamp tube of the present invention;

[0040] Figure 3This is a schematic diagram of the evaluation of the color enhancement / reduction percentage of 16 average color samples using the spectrum of an F32T8 fluorescent lamp tube using the IES-TM30 method in the present invention;

[0041] Figure 4 Schematic diagram of a white light source realizing a system for highlighting the main color of the present invention;

[0042] Figure 5 It is the different overall luminous spectra emitted by the luminous module of the present invention under different driving settings;

[0043] Figure 6 It is a schematic diagram of the algorithm module of the present invention;

[0044] Figure 7 is the reflectance spectrum of some color samples (IES01 to IES10) in the IES-TM-30 standard of the present invention;

[0045] Figure 8 It is 16 average color saturation vector diagrams of the present invention;

[0046] Fig. 9 It is a schematic diagram of the spectrum of outdoor daylight and the standard color wavelength range value index;

[0047] Fig.10 It is a schematic diagram of the spectrum and standard color wavelength range value indicators of green enhanced fluorescent lamps;

[0048] Fig.11 It is a schematic diagram of the spectrum and standard color wavelength range value indicators of green enhanced LED lights;

[0049] Fig.12 It is a schematic diagram of the spectrum of the yellow and purple enhanced light source and the corresponding standard color wavelength range value index;

[0050] Fig.13 It is a schematic diagram of the spectrum of the red and green enhanced light source and the corresponding standard color wavelength range value index;

[0051] Fig.14 It is a schematic diagram of the spectrum of a green-enhanced light source and the corresponding standard color wavelength range value index;

[0052] Fig.15 It is a schematic diagram of the spectrum of a yellow-enhanced light source and the corresponding standard color wavelength range value indicator. DETAILED DESCRIPTION

[0053] To facilitate those skilled in the art to understand the present invention, the specific implementation methods of the present invention are described below in conjunction with the accompanying drawings. The accompanying drawings provide preferred embodiments of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described in this specification. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive.

[0054] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in this specification in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0055] like Figure 6 As shown, the present invention provides a method for realizing an LED backlight source that highlights the main color, and the steps are as follows:

[0056] Step S1: The optical detection device transmits the detection information to the algorithm module;

[0057] Step S2: the algorithm module determines the main color tone area information in the scene through the detection information;

[0058] Step S3: extracting the main color sample of the main color according to the main color hue area information;

[0059] Step S4: Calculate the first color coordinates of the master color sample under the reference light source and the second color coordinates of the master color sample under the target light source respectively according to the master color sample;

[0060] Step S5: Calculate the primary color saturation vector of the primary color sample according to the first and second color coordinates;

[0061] Step S6: evaluating whether the direction of the main color saturation vector is toward the color enhancement direction and evaluating whether the saturation vectors of other hues are toward the color weakening direction;

[0062] Step S7: if the direction of the main color saturation vector is toward the color enhancement direction, output the current main target light source driving information;

[0063] Step S8: if the saturation vector direction of other hues is toward the color weakening direction; output the driving information of the sub-target light sources of other hues;

[0064] Step S9: driving the device to generate a total target spectrum according to the main and other color tone sub-target light source driving information.

[0065] Preferred technical solution: In step S1, the detection information includes spectrum or RGB color information.

[0066] Preferred technical solution: The reference light source in step S4 is obtained by the algorithm module based on the detection information in step S1.

[0067] Preferred technical solution: Step S6: Evaluate whether the direction of the main color saturation vector is in the direction of color enhancement; if it is not in the direction of color enhancement, obtain the main difference by subtracting the size of the current main color saturation vector from the main standard color wavelength range value.

[0068] The preferred technical solution is: according to the main difference, by optimizing the iteration parameters, the secondary driving information of the secondary target light source after the next iteration is obtained.

[0069] Preferred technical solution: According to the secondary driving information, it is first necessary to determine whether the background color sample is white light, and the steps are as follows:

[0070] Step S31: Read whether the background color is white light according to the information in the background color database;

[0071] Step S32: If the background color is white light, execute step S4;

[0072] Step S33: If the background color is not white light, execute step S31.

[0073] Preferred technical solution: In step S6, it is evaluated whether the saturation vectors of other hues are in the direction of color attenuation; if in the direction of color attenuation, a secondary difference is obtained by subtracting the current size of the saturation vector of other colors from the wavelength range value of the other color standard color, and according to the secondary difference, the driving information of the secondary target light source of the next iteration is obtained by optimizing the iteration parameters, and step S4 is continued to be executed to calculate the second secondary color coordinates under the target light source.

[0074] Preferred technical solution: The color reference in color attenuation and color enhancement is a standard color wavelength range value based on the main color or other colors, the color attenuation direction refers to the saturation vector of the hue within the standard color wavelength range value, and the color enhancement direction refers to the saturation vector of the hue outside the standard color wavelength range value.

[0075] According to the above-mentioned method for realizing an LED backlight source that highlights the main color, a white light source realization system that highlights the main color is realized, which is divided into three modules: an optical detection module, an algorithm module, and a light-emitting device module; the optical detection module receives the optical information of the object, including but not limited to the light spectrum of the object, the red, green, and blue color stimulation values ​​of the object, etc. The optical module transmits the information to the algorithm module, calculates the driving information of the light-emitting device, such as the driving current, etc., and outputs it to the light-emitting device module, and the light-emitting device module emits the corresponding spectrum according to the driving information calculated by the algorithm module. The light-emitting device module is composed of a plurality of driving circuits, a plurality of light-emitting modules, and a single light-mixing module. The driving circuit outputs the driving current calculated by the algorithm module, and each driving current independently drives each light-emitting module to emit light, and then the light-emitting spectrum is fully mixed by the light-mixing module to emit light as a whole. Since the current of each driving circuit is independently adjustable, the luminous intensity of each light-emitting module is also independently adjustable, so the proportion of each of them in the overall light-emitting spectrum is also adjustable, and as a result, the energy distribution of the overall light-emitting spectrum is adjustable. Figure 5 The different overall luminescence spectra emitted by the four light-emitting modules under different driving settings are shown.

[0076] Figure 4 The light-emitting modules include but are not limited to various colored and white LEDs, various current-adjustable traditional light sources such as fluorescent lamps, metal halide lamps, etc.

[0077] Figure 6 The working principle of the algorithm module is demonstrated. The optical detection device transmits the detected spectrum or RGB color information to the algorithm module, and the algorithm module determines the main color hue in the scene based on this information. If the spectrum is input, the algorithm module can obtain the hue area information of the main color according to the following method:

[0078] (1) First calculate the XYZ tristimulus values ​​corresponding to the spectrum

[0079]

[0080]

[0081]

[0082] Where S(λ) is the energy distribution of the spectrum, λ is the wavelength in nanometers (nm), is the color matching function. The upper and lower limits of the integral are the visible light band: 380nm~780nm.

[0083] (2) Calculate the color coordinates (a*, b*) in the color space based on the tristimulus values ​​XYZ:

[0084]

[0085]

[0086] in:

[0087]

[0088]

[0089] Xn, Yn, and Zn are the three stimulus values ​​of the reference light source. If D65 light source is used as the reference light source, its three stimulus values ​​are

[0090] X n =95.047,

[0091] Y n =100.000,

[0092] Z n =108.883

[0093] (3) Determine which hue region the color belongs to based on the color coordinates (a*, b*). The hue region is divided into 16 regions, i.e., 16 hues. This can be achieved by looking up the IES-TM30 standard, see reference [1] David, Aurelian et al., "Development of the IES Method for Evaluating Light Source Color Reproduction", Optics Express 23.12 (2015): 15888-15906.

[0094] After obtaining the hue area of ​​the main color, the algorithm module completes the definition of the main color. According to the ambient light information obtained by the optical detection module, the color temperature of the ambient light is calculated, and then based on the color temperature, daylight with the same color temperature is used as a reference light source to obtain the spectrum of the reference light source. This process can be achieved by extracting the daylight spectrum database.

[0095] At the same time, the algorithm module randomly generates the current of each driving circuit, thereby generating the luminous spectrum of the current target light source, see Figure 5 The algorithm module will evaluate the current spectrum to determine whether it is white light. This can be achieved by calculating the color deviation value Duv. If Duv is small enough, the current spectrum is considered to be white light and output; otherwise, the luminous spectrum is regenerated until white light is obtained.

[0096] After obtaining the luminous spectra of the reference light source and the current target light source, calculate the color coordinates (a*, b*) of each color sample in the IES-TM30 standard under the illumination of these two light sources. The IES-TM30 standard defines 99 color samples, each located in 16 color gamuts, so the following steps need to be calculated separately and repeatedly for the 99 color samples. First calculate the reflection spectrum:

[0097] S r，i(λ)=S(λ)R i (λ)

[0098] Where S r，i (λ) is the reflection spectrum of the i-th IES-TM30 color sample, S(λ) is the reference light source spectrum or the target light source spectrum, which needs to be calculated separately, R i (λ) is the reflectance spectrum of the i-th color sample in the IES-TM-30 standard. Figure 6 The reflectance spectra of some color samples (IES01 to IES10) in the IES-TM-30 standard are shown. After obtaining the reflectance spectrum, the color coordinates (a*, b*) of the reflectance spectrum are calculated. The calculation method has been detailed above.

[0099] Table I Enhanced colors and enhancement ratios of various light sources

[0100]

[0101]

[0102] *The enhancement coefficient refers to the difference between the maximum enhancement ratio and the maximum weakening ratio.

[0103] Compared with the light source matching technology, the present invention has the following advantages:

[0104] 1. The color of the object is greatly enhanced. Fig.10 and Fig.11 Although both artificial light sources enhance green, the extent is small. Figure 12-15 The light source of the present invention has a large amplitude for the standard color wavelength range, and the enhancement coefficient is 2-3 times that of other light sources.

[0105] 2. The objects that can be enhanced have complete colors. Conventional light sources and LEDs generally only have standard color wavelength range values ​​for green and red, but the light source of the present invention can enhance various colors and can enhance two colors at the same time.

[0106] 3. Continuously adjustable: The method and system of the present invention can use the same device to enhance different main colors, while the light source matching technology requires multiple replacements and attempts at different light sources because the spectrum is not adjustable.

[0107] Compared with non-white light source technology, the present invention has the following advantages:

[0108] 1. The light source is still white, with high visual comfort, and does not affect the white balance setting of electronic devices such as cameras and video cameras. Table 2 shows the color deviation (Duv) of different luminous spectra obtained by the method of the present invention at various color temperatures. Compared with non-white light, the color deviation is small, indicating that the light color of these spectra is closer to natural white light. (It is generally believed that Duv < 0.007 is white light)

[0109] 2. Automatically adjust the spectrum without replacing the filter element or light source.

[0110] 3. The degree of object color enhancement is controllable, and the color effect will not be distorted due to excessive enhancement of the object color.

[0111] Light source type Absolute color deviation (Duv) sunlight <0.0001 Ordinary fluorescent lamp <0.007 General LED <0.007 Non-white light source >0.02 The light source of the present invention <0.003

[0112] The above-described embodiments of the present invention do not constitute a limitation on the protection scope of the present invention. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A method for realizing an LED backlight source that highlights a main color, characterized in that: Here are the steps: Step S1: The optical detection device transmits the detection information to the algorithm module; Step S2: the algorithm module determines the main color tone area information in the scene through the detection information; Step S3: extracting the main color sample of the main color according to the main color hue area information; Step S4: Calculate the first color coordinates of the master color sample under the reference light source and the second color coordinates of the master color sample under the target light source respectively according to the master color sample; Step S5: Calculate the primary color saturation vector of the primary color sample according to the first and second color coordinates; Step S6: evaluating whether the direction of the main color saturation vector is toward the color enhancement direction and evaluating whether the saturation vectors of other hues are toward the color weakening direction; Step S7: if the direction of the main color saturation vector is toward the color enhancement direction, output the current main target light source driving information; Step S8: If the saturation vector direction of other hues is toward the color weakening direction; Output other color tone sub-target light source driving information; Step S9: driving the device to generate a total target spectrum according to the main and other color tone sub-target light source driving information; Step S6: evaluating whether the direction of the main color saturation vector is in the direction of color enhancement; if it is not in the direction of color enhancement, obtaining the main difference by subtracting the magnitude of the current main color saturation vector from the main standard color wavelength range value; According to the main difference, by optimizing the iteration parameters, the secondary driving information of the secondary target light source after the next iteration is obtained; According to the secondary driving information, it is first necessary to determine whether the background color sample is white light, and the steps are as follows: Step S31: Read whether the background color is white light according to the information in the background color database; Step S32: If the background color is white light, execute step S4; And, in the step S6, whether the saturation vectors of other hues are in the direction of color weakening is evaluated; if in the direction of color weakening, a secondary difference is obtained by subtracting the current size of the saturation vector of other colors from the wavelength range value of the other color standard colors, and according to the secondary difference, the driving information of the secondary target light source of the next iteration is obtained by optimizing the iteration parameters, and the step S4 is continued to be executed to calculate the second secondary color coordinates under the target light source; The color reference in color attenuation and color enhancement is the standard color wavelength range value based on the main color or other colors. The color attenuation direction refers to the saturation vector of the hue to the standard color wavelength range value, and the color enhancement direction refers to the saturation vector of the hue to the outside of the standard color wavelength range value. The reference light source calculates the color temperature of the ambient light according to the ambient light information obtained by the optical detection module, and then obtains the color temperature of the ambient light by using daylight with the same color temperature.

2. The method for realizing an LED backlight source for highlighting a main color according to claim 1, characterized in that: The detection information in step S1 includes spectrum or RGB color information.

Images