An rgb lighting fixture based on a color space color point switching algorithm

Abstract

The application provides an RGB lighting lamp based on a color space color point switching algorithm, which comprises an LED light source module, an LED driving module, a storage module, an information source module, a configuration for inputting information instructions, a first color space calculation module, a second color space calculation module and a third color space calculation module. The application overcomes the uneven color distribution phenomenon of the CIEXYZ color space, and solves the problem that the color transition does not conform to the color transition perception of the human eye when a linear switching method is used for color transition. An optimized color adjusting path is obtained through the conversion of the color space, so that the transition from an initial color point to a target color point conforms to the color transition of the human eye even if the linear switching method is used.

Description

Technical Field

[0001] This application relates to the technical field of LED light mixing, specifically to an RGB lighting fixture based on a color space color point switching algorithm. Background Technology

[0002] Current RGB mixing lights offer the ability to provide thousands of colors of illumination. How to make the switching between these colors conform to human visual perception has become a key issue that needs to be addressed.

[0003] Currently, most RGB mixing lights on the market use linear switching, which is a linear change in the RGB duty cycle corresponding to two different color points. This switching method is relatively simple and easy to implement, but it does not accurately reflect human perception. When using linear switching for color transitions, as the RGB duty cycle changes, the corresponding color points on the CIE 1931 XYZ color coordinate system exhibit a linear change. Since the CIE 1931 XYZ color coordinate system is a color space with uneven color distribution (e.g., the blue area is very dense, and the color changes significantly from x to 0.3), while the green y component only changes slightly from 0.7 to 0.8. This results in color transitions that do not conform to human perception. Therefore, we need a more uniform color space. Summary of the Invention

[0004] To address the aforementioned technical problems, this application provides an RGB lighting fixture based on a color space color point switching algorithm, comprising:

[0005] LED light source module, including at least three light sources: RGB;

[0006] LED driver module, configured to provide at least 3 PWM signal outputs to control LED light source module;

[0007] The storage module is configured to store basic information about the LED light source module and preset color point information.

[0008] The information source module is configured for inputting information commands.

[0009] The first color space calculation module obtains the initial color point and the target color point, which are respectively included in the initial color coordinates and the target color coordinates in the first color space. It further determines whether the initial color point and the target color point are located in the first color space. If so, it sends the initial color coordinates and the target color coordinates information in the first color space to the second color space calculation module; otherwise, it re-obtains the initial color point and the target color point.

[0010] The second color space calculation module is configured to calculate the initial and target color coordinates for conversion to the second color space based on the initial and target color coordinates; and to calculate the calculation path A;

[0011] The third color space calculation module is configured to convert path A into path B in the first color space, further convert path B into path C in the third color space, and determine whether path C is located in the third color space. If it is, the color adjustment is performed based on path C; otherwise, the process ends.

[0012] More specifically, the first color space includes the CIE XYZ color space; the second color space includes the CIE LAB color space and the CIE LUV color space; and the third color space includes the CIE RGB color space.

[0013] The above technical solution achieves color adjustment by using an algorithm based on color space transformation, overcoming the problem that the differences between CIE RGB space and perceived colors do not completely correspond, and that the uneven distribution of CIE 1931XYZ color space may cause two colors to appear very similar in CIE RGB color space, but to humans they may appear very different.

[0014] Specifically, when the second color space is the CIE LUV color space, the initial color coordinates and the target color coordinates are converted to the CIE LUV color space according to the following formula:

[0015]

[0016] u * =13L * ×(u'-u′ n )

[0017] v * =13L * ×(v'-v′ n )

[0018] in:

[0019]

[0020]

[0021] Xn, Yn, and Zn are the tristimulus values ​​of white stimuli when a CIE standard illuminator illuminates a completely diffuse reflector and then diffusely reflects the light to the observer's eye.

[0022] The above technical solution converts the initial and target color coordinates in the CIE XYZ color space to the CIE LUV color space, preparing for the subsequent determination of the dimming path in the CIE LUV color space.

[0023] Specifically, when the second color space is the CIE LAB color space, the initial color coordinates and the target color coordinates are converted to the CIE LAB color space according to the following formula:

[0024]

[0025] in:

[0026]

[0027] The above technical solution transforms the initial and target color coordinates in the CIE XYZ color space into the CIE LAB color space, preparing for the subsequent determination of the dimming path in the CIE LAB color space.

[0028] Specifically, the initial and target color coordinates for the conversion, and the following formula: Calculate the path function A, where 0 ≤ t ≤ 1, and further, within the range of values ​​of t, uniformly select n intermediate points.

[0029] The above technical solutions are used to obtain the coordinates of the intermediate color point located on the path between the initial color coordinates and the target color coordinates in the CIE LUV and CIE LAB color spaces.

[0030] Specifically, when the second color space is the CIE LUV color space, the initial color coordinates, target color coordinates, and intermediate color point coordinates are converted to the first color space according to the following formula.

[0031]

[0032]

[0033]

[0034]

[0035]

[0036]

[0037]

[0038] The path B is obtained by connecting the initial color coordinates, the target color coordinates, and the intermediate color point coordinates of the transformation.

[0039] The above technical solutions yield the color adjustment path from the initial color coordinates to the target color coordinates in the CIE LUV color space.

[0040] Specifically, when the second color space is the CIE LAB color space, the initial color coordinates, target color coordinates, and intermediate color point coordinates are converted to the first color space according to the following formula:

[0041]

[0042]

[0043] in, The path B is obtained by connecting the initial color coordinates, the target color coordinates, and the intermediate color point coordinates of the transformation.

[0044] The above technical solutions yield the color adjustment path from the initial color coordinates to the target color coordinates in the CIE LUV color space.

[0045] Specifically, the third color space calculation module converts path B into path C based on the Grassmann three-way color mixing principle.

[0046] Specifically, the third color space calculation module uses a linear switching method to adjust the color from the initial color point to the target color point based on the duty cycle of the tristimulus values ​​at each point on path C. The points on path C include the color points corresponding to the initial color point, the target color point, and the intermediate color point being converted in path C.

[0047] The above technical solutions yield a color adjustment path that is more in line with human visual perception than the traditional method of directly connecting the initial and target color coordinates in the CIE XYZ color space.

[0048] Specifically, the LED driver module adopts a two-stage structure of AC-DC and DC-DC; specifically, the front stage of the LED driver module adopts an AC-DC structure, the rear stage adopts a DC-DC structure, and the front and rear stages of the LED driver module can be connected to multiple DC-DC structures.

[0049] Specifically, the output of the LED driver module's front-end can be connected to two or more independent DC-DC circuit structures.

[0050] Through the above technical solutions, the front stage of the LED driver module adopts an AC-DC structure to achieve constant voltage output, and the rear stage adopts DC-DC for dimming control. Furthermore, after the front stage of the LED driver module achieves constant voltage output through AC-DC, it can be connected to multiple DC-DC circuits to better realize dimming control. Attached Figure Description

[0051] The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments and, together with the description, serve to explain the principles of this application. Other embodiments and many anticipated advantages of these embodiments will be readily recognized as they become better understood through reference to the following detailed description. Elements in the drawings are not necessarily to scale. The same reference numerals refer to corresponding similar parts.

[0052] Figure 1 This is a schematic diagram of the structure of an RGB lighting fixture based on a color space color point switching algorithm according to an embodiment of this application;

[0053] Figure 2 This is a flowchart illustrating the implementation of a switching algorithm for RGB lighting fixtures based on a color space color point switching algorithm, according to an embodiment of this application.

[0054] Figure 3 This is a flowchart illustrating the conversion of a first color space to a second color space in an RGB lighting fixture based on a color space color point switching algorithm, according to an embodiment of this application.

[0055] Figures 4-1 to 4-4 This is a specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to the first specific embodiment of this application;

[0056] Figures 5-1 to 5-4 This is a specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to a second specific embodiment of this application;

[0057] Figures 6-1 to 6-4 This is a specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to a third specific embodiment of this application;

[0058] Figure 7 This is a circuit diagram of an RGB lighting fixture based on a color space color point switching algorithm according to an embodiment of this application.

[0059] The meanings of the numbers in the diagram are as follows: Information source module 601, first color space calculation module 602a, second color space calculation module 602b, third color space calculation module 602c, LED driver module 603, LED light source module 604, and storage module 605. Detailed Implementation

[0060] In the following detailed description, reference is made to the accompanying drawings, which form part of the detailed description and illustrate illustrative specific embodiments in which the present application may be practiced. In this regard, directional terms such as “top,” “bottom,” “left,” “right,” “up,” “down,” etc., are used with reference to the orientation of the described figures. Because components of the embodiments can be positioned in several different orientations, directional terms are used for illustrative purposes and are by no means limiting. It should be understood that other embodiments may be utilized or logical changes may be made without departing from the scope of the present application. Therefore, the following detailed description should not be taken in a limiting sense, and the scope of the present application is defined by the appended claims.

[0061] This application proposes an RGB lighting fixture based on a color space color point switching algorithm. Figure 1 A schematic diagram of an RGB lighting fixture based on a color space color point switching algorithm according to this embodiment is shown, as follows: Figure 1 As shown, it includes:

[0062] LED light source module 604 includes at least three light sources: RGB;

[0063] LED driver module 603 is configured to provide at least 3 PWM signal outputs to control the LED light source module;

[0064] Storage module 605 is configured to store basic information of LED light source module 604 and preset color point information;

[0065] Information source module 601 is configured for inputting information commands;

[0066] The first color space calculation module 602a is configured to calculate the coordinates of the initial color point and the target color point in the first color space based on the initial color point and the target color point; and to calculate path B.

[0067] The second color space calculation module 602b is configured to calculate the initial and target color coordinates for conversion into the second color space based on the initial and target color coordinates; and to calculate the calculation path A.

[0068] The third color space calculation module 602c is configured to calculate the conversion of path B into path C in the third color space.

[0069] Specifically, Figure 2 A flowchart of an RGB lighting fixture based on a color space color point switching algorithm according to an embodiment of this application is shown, as follows: Figure 2 As shown, the lamp can execute the following algorithm, including: inputting the initial and target point coordinates (x, y) and the number of points n;

[0070] Determine whether the input initial and target point coordinates exceed the CIE XYZ color space (first color space). If so, this method is not applicable, and new initial and target point coordinates should be re-entered. If not, select the color space to be converted (second color space) based on the characteristics of the initial and target color points. The second color space can be either the CIE LAB color space or the CIE LUV color space.

[0071] Once the second color space is selected, the input initial and target point coordinates are transformed into the second color space to obtain the transformed initial and target point coordinates; the transformed initial and target point coordinates are connected and the linear function is calculated; based on the set value of n, n points are taken on the line.

[0072] The initial and target points and the selected n points are converted to the CIE XYZ color space to obtain a new coordinate group. The new coordinate group is then converted to the CIE RGB color space (the third color space).

[0073] Determine whether the coordinates converted to the CIE RGB color space are out of bounds. If not, end the process; otherwise, return to step "Input initial and target point coordinates (x, y) and the number of points n".

[0074] Figure 3 This document illustrates a flowchart of the conversion from a first color space to a second color space in an RGB lighting fixture based on a color space color point switching algorithm, according to an embodiment of this application. Figure 3 As shown, the values ​​of X, Y, and Z roughly correspond to red, green, and blue, but these values ​​do not actually appear to be red, green, and blue; rather, they are parameters derived from red, green, and blue. The CIE 1931 XYZ color coordinates are derived from the following formula:

[0075]

[0076]

[0077]

[0078] From formula 2, we derive X + Y + Z = Y / y. Substituting this into formulas ① and ③, we can derive:

[0079]

[0080]

[0081] The conversion between CIE 1931 xyz coordinates and RGB duty cycle corresponding to color is based on the Grassmann three-way mixing formula.

[0082] The formula derived from Grassmann's three-way color mixing principle, Ci = Yi / yi:

[0083]

[0084] By reversing the above formula, we can obtain the Grassmann color mixing formula for calculating the duty cycle of the tristimulus values:

[0085]

[0086] In the formula, Yi represents the luminous flux of the three channels at full duty cycle, and x and y represent the color coordinates of the target.

[0087] Specifically, Figures 4-1 to 4-4 A specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to a first specific embodiment of this application is shown, as follows: Figures 4-1 to 4-4 As shown, when the initial color point A (0.24, 0.53), the target color point B (0.21, 0.15), and the number of points n = 40.

[0088] In the CIE XYZ color space, points A and B are directly connected by a straight line. Then, 40 points are taken along this line. Points A and B are first converted to the CIE LUV color space. Then, points A and B are connected again in this space, and 40 points are taken along the line connecting them. These 40 points are then converted to the CIE XYZ color space, and finally to the CIE RGB color space. It can be seen that compared to a direct transition in the CIE XYZ color space, because the conversion is non-linear, the step size between points in the transition process is not consistent. The color transition is more uniform than in the CIE XYZ color space, and the green area is reduced.

[0089] Specifically, Figures 5-1 to 5-4 A specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to a first specific embodiment of this application is shown, as follows: Figure 3 As shown, when the initial color point A (0.55, 0.3), the target color point B (0.24, 0.53), and the number of points n = 40.

[0090] In the CIE XYZ color space, points A and B are directly connected by a straight line. Then, 40 points are taken along this line. Points A and B are first converted to the CIE LUV color space. Then, points A and B are connected again in this space, and 40 points are taken along the line connecting them. These 40 points are then converted back to the CIE XYZ color space, and finally to the RGB color space. It can be seen that compared to a direct transition in the CIE XYZ color space, because the conversion is non-linear, the step size between points in the transition process is not constant. The color transition is more uniform than in the CIE XYZ color space, and the green area is reduced.

[0091] Specifically, Figures 6-1 to 6-4 A specific example diagram of an RGB lighting fixture based on a color space color point switching algorithm according to a first specific embodiment of this application is shown, as follows: Figure 3 As shown, when the initial color point A (0.55, 0.3), the target color point B (0.21, 0.15), and the number of points n = 40.

[0092] In the CIE XYZ color space, points A and B are directly connected by a straight line. Then, 40 points are taken along this line. Points A and B are first converted to the CIE LUV color space. Then, points A and B are connected again in this space, and 40 points are taken along the line connecting them. These 40 points are then converted back to the CIE XYZ color space, and finally to the RGB color space. It can be seen that compared to a direct transition in the CIE XYZ color space, because the conversion is non-linear, the step size between points in the transition process is not constant. The color transition is more uniform than in the CIE XYZ color space, and the green area is reduced.

[0093] Specifically, Figure 7 A circuit diagram of an RGB lighting fixture circuit based on a color space color point switching algorithm according to an embodiment of this application is shown, as follows: Figure 7 As shown, the LED driver module in the dimming and color-tuning device of this application has the following features: the LED driver module adopts a two-stage structure of AC-DC and DC-DC; specifically, the front stage of the LED driver module adopts an AC-DC structure, the rear stage adopts a DC-DC structure, and the rear stage of the LED driver module can be connected to multiple DC-DC structures.

[0094] Through the above technical solutions, the front stage of the LED driver module adopts an AC-DC structure to achieve constant voltage output, and the rear stage adopts DC-DC for dimming control. Furthermore, after the front stage of the LED driver module achieves constant voltage output through AC-DC, it can be connected to multiple DC-DC circuits to better realize dimming control.

[0095] It is obvious that those skilled in the art can make various modifications and alterations to the embodiments of this application without departing from the spirit and scope of this application. In this way, this application also aims to cover such modifications and alterations if they fall within the scope of the claims 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 described in mutually different dependent claims does not indicate that a combination of these measures cannot be used for profit. Any reference numerals in the claims should not be considered limiting in scope.

Claims

1. An RGB lighting fixture based on a color space color point switching algorithm, characterized in that, include: LED light source module, including at least three light sources: RGB; An LED driver module is configured to provide at least three PWM signal outputs to control the LED light source module. The storage module is configured to store basic information of the LED light source module and preset color point information; The information source module is configured for inputting information commands. The first color space calculation module obtains the initial color point and the target color point, and determines whether the initial color point and the target color point are located in the first color space. If so, it sends the initial color coordinates and target color coordinates information in the first color space to the second color space calculation module; otherwise, it re-obtains the initial color point and the target color point. The second color space calculation module is configured to calculate the initial and target color coordinates for conversion into the second color space based on the initial and target color coordinates. And calculation path A; The third color space calculation module is configured to convert path A into path B in the first color space, convert path B into path C in the third color space, and determine whether path C is located in the third color space. If so, color adjustment is performed based on path C; otherwise, the process ends.

2. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, The first color space includes the CIE XYZ color space; the second color space includes the CIE LAB color space or the CIE LUV color space; and the third color space includes the CIE RGB color space.

3. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, When the second color space is the CIE LUV color space, the initial color coordinates and target color coordinates are converted to the CIE LUV color space according to the following formula: ， ， ， in: , ， Here are the chromaticity coordinates of the color sample; Let X, Y, and Z be the chromaticity coordinates of the light source, and X, Y, and Z be the tristimulus values ​​of the sample. The tristimulus value is the value of white stimulus when a CIE standard illuminator illuminates a completely diffuse reflector and then diffusely reflects the light to the observer's eye.

4. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, When the second color space is the CIELAB color space, the initial color coordinates and target color coordinates are converted to the CIELAB color space according to the following formula. ， in: .

5. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, Based on the initial and target color coordinates of the transformation and the following formula: Calculate the function of the path A, where 0≤t≤1, and further, within the range of t, uniformly select n intermediate points.

6. An RGB lighting fixture based on a color space color point switching algorithm according to claim 3, characterized in that, The initial color coordinates, target color coordinates, and intermediate color point coordinates are converted to the first color space according to the following formula: ， ， ， ， ， ， ， The path B is obtained by connecting the initial color coordinates, the target color coordinates, and the coordinates of the intermediate color point after transformation.

7. An RGB lighting fixture based on a color space color point switching algorithm according to claim 4, characterized in that, The initial color coordinates, target color coordinates, and intermediate color point coordinates are converted to the first color space according to the following formula: ， ， in, The path B is obtained by connecting the initial color coordinates, the target color coordinates, and the coordinates of the intermediate color point after transformation.

8. An RGB lighting fixture based on a color space color point switching algorithm according to claim 6 or 7, characterized in that, The third color space calculation module converts path B into path C based on the Grassmann three-way color mixing principle.

9. An RGB lighting fixture based on a color space color point switching algorithm according to claim 8, characterized in that, The third color space calculation module uses a linear switching method to adjust the color of the initial color point to the target color point based on the duty cycle of the tristimulus values ​​of each point on the path C. The points on the path C include the color points in the path C corresponding to the coordinates of the initial color point, the target color point, and the intermediate color point of the conversion.

10. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, The LED driver module adopts a two-stage structure of AC-DC and DC-DC.

11. An RGB lighting fixture based on a color space color point switching algorithm according to claim 1, characterized in that, The output terminal of the LED driver module can be connected to two or more independent DC-DC circuit structures.

Images