A dimming and color adjusting method and device

Abstract

The application provides a dimming and color adjusting method and device. The dimming and color adjusting method comprises the following steps: S1, acquiring color coordinates of an initial color point Q and a target color point M; S2, calculating color coordinates of intersection points E and F of a straight line QM and a color domain boundary according to the color coordinates of the initial color point Q and the target color point M, wherein the color domain boundary is the color domain boundary closest to the initial color point Q and the target color point M, calculating a dimming duty ratio for realizing the intersection points E and F, and calculating a dimming duty ratio for realizing the initial color point Q and the target color point M by mixing the intersection points E and F according to the duty ratio for realizing the intersection points E and F; and S3, controlling an output PWM signal according to the calculated dimming duty ratio, and realizing dimming and color adjusting by switching different step lengths / same step lengths. The application can realize dimming and color adjusting by adjusting one group or two groups of two-way monochromatic light sources, and can reduce obvious shaking and switching feelings in the process of dimming and color adjusting.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of LED mixed light, and in particular to a light and color adjusting method and device. BACKGROUND

[0002] There are two types of color adjusting lamps on the market. One type is based on double-color LED lamp beads combined with PWM technology to control the color switching of the lamp. The advantage of this type of lamp is that the color switching process is uniform without obvious step feeling. This is mainly because the color point moves on the connecting line of the double-color LED lamp beads. However, this is also the limitation of this type of lamp. When the target color point is not on the connecting line of the double-color LED lamp beads, the lamp cannot emit the target color, and cannot meet the customer's demand for multiple colors.

[0003] The other type is based on RGB lamp beads combined with PWM technology to control the color switching of the lamp. The advantage of this type of lamp is that it has a large color gamut space, and the colors in the color gamut space can be realized by changing the duty cycle of the RGB three light sources. However, in the process of realizing the target color point A to the target color point B, the three light sources need to work together. The switching step of the PWM of each channel is the same in the color switching process, which easily leads to obvious shaking and switching feeling in the color switching process.

[0004] Therefore, the present technology proposes a lighting device. In the color switching process, the PWM signals of each channel are switched through different step lengths / same synchronization lengths, which can make the trajectory of the color point corresponding to the light emitted by the lamp on the CIE1931 color chart be a straight line. This can realize uniform color switching like a double-color LED color adjusting lamp, and can also realize a large color gamut space like an RGB lamp, and realize multiple color adjusting possibilities. SUMMARY

[0005] In order to solve the above technical problems, the present application provides a light and color adjusting method and device.

[0006] First of all, it should be pointed out that: light adjustment is the basis of color adjustment. The essence of color temperature adjustment is to change the color temperature by adjusting the luminosity ratio of cold and warm light sources. The luminous flux of LED is linearly related to the duty cycle of PWM light adjustment. By changing the duty cycle of the PWM driving signal, the on and off time of the LED lamp changes with the change of the duty cycle of the PWM driving signal.

[0007] In one aspect of the present application, a light and color adjusting method is provided, comprising: S1: obtaining the color coordinates of an initial color point Q and a target color point M;

[0008] S2: According to the color coordinates of the initial color point Q and the target color point M, the color coordinates of the intersection points E and F of the straight line QM and the color gamut boundary are calculated, wherein the color gamut boundary is the color gamut boundary closest to the initial color point Q or the target color point M, the dimming duty cycles of the one / two sets of monochromatic light sources realizing the intersection points E and F are calculated, and the dimming duty cycles of the monochromatic light sources realizing the initial color point Q and the target color point M are calculated according to the dimming duty cycles of the one / two sets of monochromatic light sources realizing the intersection points E and F, and the dimming duty cycles of the monochromatic light sources realizing the initial color point Q and the target color point M are calculated according to the calculated dimming duty cycles.

[0009] S3: The output PWM signal is controlled according to the calculated duty cycles, and the dimming and color adjustment are realized through the switching of different steps / same steps.

[0010] Through the above technical solutions, when the initial color point Q and the target color point M are on the same color gamut boundary, the uniform switching of colors is realized by changing the duty cycles of the two monochromatic light sources at the end points of the color gamut boundary, and the duty cycles of the two monochromatic light sources are controlled by outputting two PWM signals to increase and decrease by the same step, thereby realizing dimming and color adjustment.

[0011] In specific embodiments, when the initial color point Q and the target color point M are on the same color gamut boundary, the dimming duty cycles of the monochromatic light sources realizing the initial color point Q and the target color point M are calculated.

[0012] In specific embodiments, when the initial color point Q and the target color point M are not on the same color gamut boundary, the dimming duty cycles of the two sets of monochromatic light sources realizing the initial color point Q and the target color point M are calculated.

[0013] Through the above technical solutions, two cases are distinguished when the initial color point Q and the target color point M are on the color gamut boundary.

[0014] In specific embodiments, when the initial color point Q is on the color gamut boundary and the target color point M is not on the color gamut boundary, a straight line QM function is calculated according to the color coordinates of the initial color point Q and the target color point M, the color coordinates of the intersection point F of the straight line QM and the color gamut boundary are obtained, the first dimming duty cycle of the two monochromatic light sources realizing the intersection point F is calculated, the second dimming duty cycle of the two monochromatic light sources realizing the initial color point Q is calculated, the third dimming duty cycle of the intersection point F and the initial color point Q realizing the target color point M is calculated, and the fourth dimming duty cycle of the monochromatic light sources realizing the target color point M is calculated according to the first, second, and third dimming duty cycles.

[0015] In a specific embodiment, when it is judged that the initial color point Q and the target color point M are not located on the color gamut boundary, a straight line QM function is calculated according to the color coordinates of the initial color point Q and the target color point M, color coordinates of the intersection points E and F of the straight line QM and the color gamut boundary are obtained, a first dimming duty cycle of the two single-color light sources realizing the intersection point E and a second dimming duty cycle of the two single-color light sources realizing the intersection point F are calculated, a third dimming duty cycle of the intersection point E and the intersection point F realizing the initial color point Q is calculated, a fourth dimming duty cycle of the intersection point E and the intersection point F realizing the target color point M is calculated, a fifth dimming duty cycle of the single-color light source realizing the initial color point Q and a sixth dimming duty cycle of the single-color light source realizing the target color point M are calculated according to the first dimming duty cycle, the second dimming duty cycle, the third dimming duty cycle and the fourth dimming duty cycle.

[0016] In a specific embodiment, when it is judged that the initial color point Q is not located on the color gamut boundary and the target color point M is located on the color gamut boundary, a straight line QM function is calculated according to the color coordinates of the initial color point Q and the target color point M, color coordinates of the intersection point E of the straight line QM and the color gamut boundary are obtained, a first dimming duty cycle of the two single-color light sources realizing the intersection point E is calculated, a second dimming duty cycle of the two single-color light sources realizing the target color point M is calculated, a third dimming duty cycle of the intersection point E realizing the initial color point Q and the target color point M is calculated, and a fourth dimming duty cycle of the single-color light source realizing the initial color point Q is calculated according to the first duty cycle, the second duty cycle and the third duty cycle.

[0017] Through the above technical solution, even if the initial color point Q and / or the target color point M is not located on the color gamut boundary, the dimming duty cycle of the intersection point realizing the initial color point Q and / or the target color point M can be calculated by calculating the color coordinates of the intersection points of the straight line QM function and the color gamut boundary, the duty cycle of one or two groups of single-color light sources realizing the intersection point can be further calculated, and finally the duty cycle of the single-color light source realizing the initial color point Q and / or the target color point M can be calculated, so that the PWM signals are switched through different step lengths / same phase lengths, and the shaking feeling and switching feeling of light transformation are reduced.

[0018] In another aspect of the present application, a dimming and color adjusting device is provided, comprising:

[0019] An LED driving module configured to provide at least two PWM signal outputs to control the LED light source module;

[0020] An LED light source module configured to provide at least RGB three kinds of light sources;

[0021] A calculation module configured to calculate the duty cycle of one / two groups of two single-color light sources realizing the initial color point Q and the target color point M according to the color coordinates of the initial color point Q and the target color point M, and to calculate the PWM signal required by the LED driving module according to the calculated duty cycle.

[0022] In specific embodiments, the color gamut of the LED light source module is at least 95% NTSC color gamut or 99% sRGB color gamut.

[0023] Through the above technical solution, the LED light source module can use light source components with different color gamuts, which can be replaced according to actual needs to adapt to more application scenarios.

[0024] In preferred embodiments, it further comprises an information module configured to input information to the calculation module.

[0025] In preferred embodiments, it further comprises a storage module configured to store basic information of the LED light source module and preset color point information, wherein the color point information includes or mainly includes coordinates x, y and brightness Y.

[0026] Through the above technical solution, the storage module stores preset color points and color points within the error range of the color points, and the pre-stored color point information and the color point information within the error range are used to accurately and quickly determine the color point information during use, which is also conducive to calculating the duty cycle and improving the color adjustment precision.

[0027] In specific embodiments, the LED drive module adopts a two-stage structure of AC-DC and DC-DC, the front stage CV outputs, the rear stage DCDC performs dimming control, and the constant voltage output rear end can be connected to multiple DCDCs.

[0028] Through the above technical solution, the two-stage architecture of AC-DC + DC-DC is adopted, the front stage CV outputs, the rear stage DCDC performs dimming control, and the constant voltage output rear end can be connected to multiple DCDCs. The circuit can achieve a dimming depth of 0.1%, and each DCDC is independent of each other, which can well realize color point conversion.

[0029] Compared with the prior art, the beneficial results of the present application are:

[0030] (1) During the color switching process, the PWM signals of each channel are switched through different step lengths / same phase lengths, which can make the trajectory of the color points corresponding to the light emitted by the lamp on the CIE1931 color chart be a straight line, so that the color can be uniformly switched like a double-color LED color adjustment lamp, and a large color gamut space can be achieved like an RGB lamp, realizing multiple color adjustment possibilities.

[0031] (2) By calculating the duty cycle and outputting different PWM signals, the dimming path presents a straight line, which effectively reduces the shaking and switching feeling in the switching process compared with the traditional technical solution which needs to change the duty cycles of the RGB three light sources. BRIEF DESCRIPTION OF DRAWINGS

[0032] The accompanying drawings are included to provide a further understanding of embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain principles of the present application. Other embodiments and many of the intended advantages of the present application will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings. The elements of the drawings are not necessarily to scale relative to each other. Like reference numerals designate corresponding similar parts.

[0033] Figure 1 is a flow chart of a dimming and color adjusting method according to an embodiment of the present application;

[0034] Figure 2 is a flow chart of step S2 of a dimming and color adjusting method according to an embodiment of the present application;

[0035] Figure 3 is a specific example diagram of a dimming and color adjusting method according to a first specific embodiment of the present application;

[0036] Figure 4 is a specific example diagram of a dimming and color adjusting method according to a second specific embodiment of the present application;

[0037] Figure 5 is a specific example diagram of a dimming and color adjusting method according to a third specific embodiment of the present application;

[0038] Figure 6 is a specific example diagram of a dimming and color adjusting method according to a fourth specific embodiment of the present application;

[0039] Figure 7 is a specific example diagram of a dimming and color adjusting method according to a fifth specific embodiment of the present application;

[0040] Figure 8 is a structural schematic diagram of a dimming and color adjusting device according to an embodiment of the present application;

[0041] Figure 9 is a circuit structural diagram of a dimming and color adjusting device according to an embodiment of the present application.

[0042] Meaning of each number in the figure: LED light source module S803, LED driving module S802, calculation module S801, information source module S804, storage module S805. DETAILED DESCRIPTION

[0043] In the following detailed description, reference is made to the accompanying drawings, which form a part hereof, and in which are shown by way of illustration illustrative embodiments in which the application can be practiced. For purposes of explanation and illustration, directional terms are used with reference to the orientation of the described figures. However, it is to be understood that the embodiments can be practiced in other orientations than those presented in the figures. The directional terms, such as "top," "bottom," "left," "right," "upper," "lower," and the like are used to aid in describing the embodiments and are not to be construed as limiting. It is to be understood that other embodiments can be utilized and structural or logical changes can be made without departing from the scope of the present application. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0044] The present application provides a dimming and color adjusting method and device, Figure 1 A flow chart of a dimming and color adjusting method according to the present embodiment is shown in FIG. 1, which comprises the following steps: Figure 1

[0045] S1: obtaining color coordinates of an initial color point Q and a target color point M;

[0046] S2: calculating color coordinates of intersection points E and F of a straight line QM and a color gamut boundary according to the color coordinates of the initial color point Q and the target color point M, wherein the color gamut boundary is the color gamut boundary closest to the initial color point Q or the target color point M, calculating dimming duty cycles of a group / two groups of monochromatic light sources realizing the intersection points E and F, and calculating dimming duty cycles of monochromatic light sources realizing the initial color point Q and the target color point M according to the calculated dimming duty cycles of the group / two groups of monochromatic light sources realizing the intersection points E and F;

[0047] S3: controlling output PWM signals according to the calculated dimming duty cycles, and realizing dimming and color adjusting through switching of different steps / identical steps.

[0048] Figure 2 A flow chart of step S2 of a dimming and color adjusting method according to the present embodiment is shown in FIG. 2, which comprises the following steps: Figure 2

[0049] ​​If the initial color point and the target color point are not located on the same color gamut boundary, S2051 is entered to calculate the color mixing ratio according to the color gamut boundary where the target color point is located, and finally S208 is entered to output the result;

[0050] If the target color point is not located on the color gamut boundary, S207 is entered to calculate the connecting line of the target color point and the initial color point, obtain the intersection of the connecting line and the nearest color gamut boundary of the target color point, and perform transformation based on the intersection and the initial color point to obtain the target color point;

[0051] If the initial color point is not located on the color gamut boundary, S206 is entered to determine whether the target color point is located on the color gamut boundary. If yes, S2061 is entered to calculate the intersection of the connecting line of the target color point and the initial color point and the nearest color gamut boundary of the target color point, and calculate the color mixing ratio;

[0052] If the target color point is not located on the color gamut boundary, S207 is entered to calculate the intersection of the connecting line of the target color point and the initial color point and the nearest color gamut boundary of the target color point, and perform transformation according to the connecting line of the target color point and the initial color point.

[0053] Specifically, Figure 3 A specific example diagram of a dimming and color adjusting method according to a first specific embodiment of the present application is shown as follows: Figure 3 As shown in the figure, when the initial color point A and the target color point B are on the same color gamut boundary, the uniform switching of colors is realized by changing the duty cycles of the two kinds of monochromatic light sources at the end points of the color gamut boundary. The switching steps of the color point Q to the color point M are as follows:

[0054] A. The duty cycles of the two kinds of monochromatic light sources (in this example, light source G and light source R) to realize the initial color point Q and the target color point M are calculated according to formula 1;

[0055] The duty cycles of the initial color point Q: ηG(Q), ηR(Q), ηG(Q)+ηR(Q)=1;

[0056] The duty cycles of the target color point M: ηG(M), ηR(M), ηG(M)+ηR(M)=1;

[0057] B. The LED drive outputs two PWM signals to control the duty cycles of the two kinds of light sources to change in the same length and increase and decrease, realizing dimming and color adjusting;

[0058] ηG(Q)→ηG(M), ηR(Q)→ηR(M).

[0059] Specifically, Figure 4 A specific example diagram of a dimming and color adjusting method according to a second specific embodiment of the present application is shown as follows: Figure 3 As shown in the figure, when the initial color point Q and the target color point M are not on the same color gamut boundary, the switching steps of the color point Q to the color point M are as follows:

[0060] A. Grouping the RGB three light sources: the first group B+R; the second group G+R, the third group G+B;

[0061] B. Calculating the duty cycle ηB and ηR of the two single color light sources (in this example, light source B and light source R) in the first group of light sources to realize the initial color point A, ηB+ηR=1;

[0062] C. Calculating the duty cycle ηG and ηR of the two single color light sources (in this example, light source G and light source R) in the second group of light sources to realize the initial color point B, ηG+ηR=1;

[0063] D. According to the formula k1(ηB, ηR)+k2(ηG, ηR)=1, k1 and k2 are the scaling coefficients of the duty cycles of the two light sources in the first group and the second group of mixed light sources.

[0064] E. Outputting the duty cycles of the RGB three light sources: R:G:B=(k1+k2)ηR:k2ηG:(k1+k2)ηB, wherein (k1+k2)ηR+k2ηG+(k1+k2)ηB=1.

[0065] Specifically, Figure 5 A specific example diagram of a dimming and color adjusting method according to a third specific embodiment of the present application is shown as follows: Figure 5 As shown in the figure, when the initial color point Q is on the color gamut boundary, the target color point M is in the color gamut space, and the switching step from the color point Q to the color point M is as follows:

[0066] A. Grouping the RGB three light sources: the first group B+R; the second group G+R, the third group G+B;

[0067] B. Calculating the function of the straight line QM according to the color coordinates of the initial color point Q and the target color point M;

[0068] C. Calculating the color coordinates of the intersection F of the straight line QM and the color gamut boundary, wherein the color gamut boundary is the color gamut boundary closest to the target color point;

[0069] D. Calculating the duty cycles (ηG, ηR) of the two light sources (in this example, green G and red R) required by the second group of light sources to realize the color point Q according to the formula;

[0070] E. Calculating the duty cycles (ηB, ηR) of the two light sources (in this example, blue B and red R) required by the first group of light sources to realize the color point F and the luminance of the color point M according to the formula, wherein ηB+ηR=1;

[0071] F. According to the calculation results of C and D and the Grassmann's law of mixture, the duty cycles of the two groups of light sources to mix any color point on the straight line QM are k1 and k2, wherein k1+k2+1;

[0072] G. Let k1 and k2 change according to the specified step size, control the RGB three-way to change according to different duty cycles, realize the switching of color point Q to color point M.

[0073] Specifically, Figure 6 A specific example diagram of a dimming and color adjusting method according to the fourth specific embodiment of the present application is shown as follows: Figure 6 As shown, when the initial color point Q and the target color point M are in the color gamut space, the switching steps of color point Q to color point M are as follows:

[0074] A. Group the RGB three-way light sources: the first group B+R; the second group G+R, and the third group G+B;

[0075] B. Calculate the straight line QM function according to the color coordinates of the initial color point Q and the target color point M;

[0076] C. Calculate the color coordinates of the intersection points E and F of the straight line QM and the color gamut boundaries GR and BR;

[0077] D. Calculate the duty cycles (ηG, ηR) of the two light sources (green G and red R in this example) required for the second group of light sources to realize color point E and the brightness of color point Q according to the formula, wherein ηG+ηR=1;

[0078] E. Calculate the duty cycles (ηB, ηR) of the two light sources (blue B and red R in this example) required for the first group of light sources to realize color point F and the brightness of color point M according to the formula, wherein ηB+ηR=1;

[0079] F. According to the calculation results of C and D and the Grassmann's law of mixture, the duty cycles of the first group of light sources and the second group of light sources to mix color point Q are k1 and k2, and k1+k2=1;

[0080] G. According to the calculation results of C and D and the Grassmann's law of mixture, the duty cycles of the first group of light sources and the second group of light sources to mix color point M are k1' and k2', and k1'+k2'=1;

[0081] H. Let the duty cycles of the two groups of light sources change according to the specified step size, that is, control the RGB three-way to change according to different duty cycles, realize the switching of color point Q to color point M.

[0082] Specifically, Figure 7 A specific example diagram of a dimming and color adjusting method according to the fifth specific embodiment of the present application is shown as follows: Figure 7 As shown, when the initial color point Q is in the color gamut space and the target color point M is on the boundary, the switching steps of color point Q to color point M are as follows:

[0083] A. Group the three RGB light sources: Group 1: B+R; Group 2: G+R; Group 3: G+B;

[0084] B. Calculate the line QM function based on the color coordinates of the initial color point Q and the target color point M;

[0085] C. Calculate the color coordinates of the intersection point F of the line QM and the color gamut boundary BR;

[0086] D. Calculate the duty cycles ηG and ηR (in this example, green G and red R) of the two light sources required to achieve color point M using the formula, where ηG + ηR = 1.

[0087] E. Calculate the duty cycles ηB and ηR (in this example, blue B and red R) of the two light sources required to achieve color point F using the formula, where ηB + ηR = 1.

[0088] F. Based on the calculation results of C and D and Grassmann's law of color mixing, calculate the duty cycles, k1 and k2, of the mixed color point Q of the first group of light sources and the second group of light sources, where k1+k2+1;

[0089] G. Allow k1 and k2 to change according to a specified step size, that is, control the RGB three channels to change according to different duty cycles, so as to switch from color point Q to color point M.

[0090] Specifically, Figure 8 A schematic diagram of a dimming and color-tuning device according to an embodiment of this application is shown, as follows: Figure 8 As shown, the device includes: an LED light source module S803, an LED driver module S802, a computing module S801, an information source module S804, and a storage module S805; wherein, the LED light source module S803 includes at least three light sources: RGB.

[0091] The LED driver module S802 provides at least two PWM signal outputs to control the LED light source module, with PWM signal accuracy reaching 0.1%. The calculation module S801 retrieves information from the storage module S805 according to the instructions from the command input module to calculate the PWM signal that the LED driver module S802 needs to output. The storage module S805 stores the basic information of the LED light source module and the preset color point information, including or mainly including color coordinates x, y and brightness Y. The information source module S804 is for APP, remote control, knob, etc.

[0092] Specifically, Figure 9 A circuit diagram of a dimming and color-tuning device circuit according to an embodiment of this application is shown, such as... Figure 9As shown, the LED driving module in the light-adjusting and color-adjusting device has the following characteristics: an ACDC+DCDC two-stage architecture is adopted, the front-stage CV is output, the rear-stage DCDC is used for light-adjusting control, the constant voltage output rear end can be connected with multiple DCDCs, the circuit can realize 0.1% light-adjusting depth, and the multiple DCDCs are independent of each other, so that the color point can be well realized.

[0093] Obviously, various modifications and changes can be made to the embodiments of the present application by those skilled in the art without departing from the spirit and scope of the present application. In this way, the present application also aims to cover these modifications and changes if they are within the scope of the claims of the present application and their equivalents. The word "comprising" does not exclude the presence of other elements or steps not listed in the claims. The simple fact that certain measures are recited in mutually different dependent claims does not mean that the combination of these measures cannot be used to advantage. Any reference signs in the claims should not be considered as limiting the scope.

Claims

1. A method of dimming and toning, characterized by: The method comprises the following steps: S1: obtaining color coordinates of an initial color point Q and a target color point M; S2: calculating color coordinates of intersection points E and F of a straight line QM and a color gamut boundary according to the color coordinates of the initial color point Q and the target color point M, wherein the color gamut boundary is the color gamut boundary closest to the initial color point Q or the target color point M, calculating dimming duty cycles of a group / two groups of monochromatic light sources achieving the intersection points E and F, calculating dimming duty cycles of the intersection points E and F achieving the initial color point Q and the target color point M according to the dimming duty cycles of the group / two groups of monochromatic light sources achieving the intersection points E and F, and calculating dimming duty cycles of monochromatic light sources achieving the initial color point Q and the target color point M according to the dimming duty cycles of the intersection points E and F achieving the initial color point Q and the target color point M; S3: controlling output PWM signals according to the calculated dimming duty cycles of the monochromatic light sources achieving the initial color point Q and the target color point M, and achieving dimming and color adjusting through switching of different steps / identical steps.

2. The method of claim 1, wherein, The step S2 specifically comprises: when the initial color point Q and the target color point M are on the same color gamut boundary, calculating dimming duty cycles of monochromatic light sources achieving the initial color point Q and the target color point M.

3. The method of claim 1, wherein, The step S2 specifically comprises: when the initial color point Q and the target color point M are not on the same color gamut boundary, calculating dimming duty cycles of two groups of monochromatic light sources achieving the initial color point Q and the target color point M.

4. The method of claim 1, wherein, The step S2 specifically comprises: when the initial color point Q is on the color gamut boundary and the target color point M is not on the color gamut boundary, calculating a function of the straight line QM according to the color coordinates of the initial color point Q and the target color point M, obtaining color coordinates of the intersection point F of the straight line QM and the color gamut boundary, calculating a first dimming duty cycle of two groups of monochromatic light sources achieving the intersection point F, calculating a second dimming duty cycle of two groups of monochromatic light sources achieving the initial color point Q, calculating a third dimming duty cycle of the intersection point F and the initial color point Q achieving the target color point M, and calculating a fourth dimming duty cycle of monochromatic light sources achieving the target color point M according to the first dimming duty cycle, the second dimming duty cycle and the third dimming duty cycle.

5. The method of claim 1, wherein, The step S2 specifically comprises: when judging that the initial color point Q and the target color point M are not located on the color gamut boundary, calculating a straight line QM function according to the color coordinates of the initial color point Q and the target color point M, obtaining the color coordinates of the intersection points E and F of the straight line QM and the color gamut boundary, calculating a first dimming duty cycle of two single-color light sources for realizing the intersection point E and a second dimming duty cycle of two single-color light sources for realizing the intersection point F, calculating a third dimming duty cycle for realizing the intersection point E and the intersection point F of the initial color point Q, calculating a fourth dimming duty cycle for realizing the intersection point E and the intersection point F of the target color point M, calculating a fifth dimming duty cycle of a single-color light source for realizing the initial color point Q and a sixth dimming duty cycle of a single-color light source for realizing the target color point M according to the first dimming duty cycle, the second dimming duty cycle, the third dimming duty cycle and the fourth dimming duty cycle.

6. The method of claim 1, wherein, The step S2 specifically comprises: when judging that the initial color point Q is not located on the color gamut boundary and the target color point M is located on the color gamut boundary, calculating a straight line QM function according to the color coordinates of the initial color point Q and the target color point M, obtaining the color coordinates of the intersection point E of the straight line QM and the color gamut boundary, calculating a first dimming duty cycle of two single-color light sources for realizing the intersection point E, calculating a second dimming duty cycle of two single-color light sources for realizing the target color point M, calculating a third dimming duty cycle for realizing the intersection point E of the initial color point Q and the target color point M, and calculating a fourth dimming duty cycle of a single-color light source for realizing the initial color point Q according to the first dimming duty cycle, the second dimming duty cycle and the third dimming duty cycle.

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