Systems and methods for color targeting for accurate whites and saturated colors - Patents.com

Abstract

A method for driving a plurality of LED-based light sources to provide accurate white points and saturated color points, the method including receiving or setting a selectable target chromaticity, determining that the selectable target chromaticity is between two vertices of a global common color gamut, defining an interior region within the global common color gamut, calculating a first oriented distance between the selectable target chromaticity and a transition boundary of the interior region and a second oriented distance between the selectable target chromaticity and a straight edge of the global common color gamut, and modifying the selectable target chromaticity to a modified target chromaticity within a light fixture gamut based at least in part on the calculated first and second oriented distances, or generating activation signals to drive a plurality of light sources based on the selectable target chromaticity based at least in part on the calculated first and second oriented distances.

Description

[Technical field]

[0001] The present disclosure generally relates to lighting systems and methods for color targeting precise white / pastel points and saturated colors using Light Emitting Diodes (LEDs) without requiring a user to change settings or reconfigure the lighting fixture. [Background technology]

[0002] An LED lighting product can only produce colors within its actual color gamut. Due to manufacturing variations inherent in LED technology, no two LEDs are exactly the same. Color differences can be noticeable, especially between different products and LED manufacturers. As a result, no two LED lights produce the exact same color gamut. For example, two LED lights can produce a particular color point that represents white light, but they have different color gamuts and therefore will produce that color point in different ways.

[0003] Despite these differences, it is desirable to be able to specify the exact color of light, especially white light. One typical solution to this problem involves restricting all LED products to a small color gamut common to all of them. This is beneficial because it standardizes the way in which color points are communicated to the products. Using a small common color gamut allows different LED fixtures to accurately target colors within the small common color gamut. However, as the number of LED products in a lighting system increases, the size of the color gamut common to all products decreases. The small size of the common color gamut means that the products can only produce white and pastel colors, but cannot produce saturated colors. Thus, different LED fixtures can accurately target colors within the small common color gamut, but lose the ability to produce saturated colors that lie on the exterior of these color gamuts. Other solutions sacrifice consistency between LED fixtures for the widest possible color gamut (i.e., the most saturated colors). Switching between providing an exact white point and providing fully saturated colors requires changing settings or reconfiguring the LED lighting fixture.

[0004] Thus, there is a need in the art for LED lighting systems and methods that are configured to provide accurate white points and saturated colors without changing settings or reconfiguring the lighting fixture, and the systems and methods described herein exhibit consistent behavior with respect to DMX values ​​and temperature changes. Summary of the Invention [Problem to be solved by the invention]

[0005] The present disclosure relates to an inventive system and method for controlling one or more LED lighting products to provide accurate white / pastel and saturated color points without requiring settings to be changed or lighting fixture reconfiguration. The system disclosed herein includes at least one lighting product including a plurality of light sources, preferably LED-based light sources. The system further includes a controller configured to designate a central portion of an operating gamut as an accurate region for accurately targeting white / pastel colors and an outer portion of the operating gamut as a saturated region for targeting saturated colors. The controller is further configured to blend between the central portion and the outer portion based on the color points requested by a user. [Means for solving the problem]

[0006] In general, in one aspect, a method is provided for driving a plurality of LED-based light sources at a selectable target chromaticity in a color space, the method including receiving or setting a selectable target chromaticity within a global common gamut of the color space, determining that the selectable target chromaticity is between two adjacent vertices of a first plurality of vertices of the global common gamut, defining an inner region within the global common gamut at a transition boundary, and calculating a first directed distance between the selectable target chromaticity and the transition boundary of the inner region and a second directed distance between the selectable target chromaticity and a straight side of the global common gamut between the two adjacent vertices. The method further includes modifying the selectable target chromaticity based at least in part on the calculated first oriented distance and the second oriented distance to a modified target chromaticity within the light fixture gamut or generating an activation signal to drive the plurality of LED-based light sources based on the selectable target chromaticity based at least in part on the calculated first oriented distance and the second oriented distance.

[0007] In an exemplary embodiment, the method further includes calculating a light fixture color gamut, where the light fixture color gamut at least partially encloses the global common color gamut, and the step of calculating the light fixture color gamut includes determining or receiving colorimetric data indicative of colorimetric characteristics of light emitted by the multiple LED-based light sources, where the colorimetric characteristics define the light fixture color gamut.

[0008] In an exemplary embodiment, the light fixture color gamut completely encloses the global common color gamut.

[0009] In an exemplary embodiment, the step of defining the interior region includes defining a global gamut center by calculating an average of chromaticity values ​​of color points at a first plurality of vertices of the global common gamut, extending lines between the global gamut center and each of the first plurality of vertices of the global common gamut, and positioning a second plurality of vertices such that each vertex of the second plurality of vertices intersects one of the lines extending between the global gamut center and each of the first plurality of vertices, and a transition boundary connects the second plurality of vertices.

[0010] In an exemplary embodiment, the step of defining the interior region includes defining a global gamut center by calculating an average of chromaticity values ​​of color points at a first plurality of vertices of the global common gamut, positioning a second plurality of vertices such that each vertex of the second plurality of vertices is between the global gamut center and a respective vertex of the first plurality of vertices, and connecting transition boundaries between the second plurality of vertices, wherein the first plurality of vertices and the second plurality of vertices are not collinear with the global gamut center.

[0011] In an exemplary embodiment, the step of determining that the selectable target chromaticity is between two adjacent vertices of the first plurality of vertices of the global common gamut includes defining a global gamut center by calculating an average of chromaticity values ​​of color points at the first plurality of vertices of the global common gamut; extending a line between the global gamut center and each of the first plurality of vertices of the global common gamut; and determining that the selectable target chromaticity is between the two adjacent lines extending between the global gamut center and the first plurality of vertices of the global common gamut by calculating a third directional distance and a fourth directional distance between the selectable target chromaticity and the lines extending between the global gamut center and the two adjacent vertices of the global common gamut.

[0012] In an exemplary embodiment, the step of calculating the first oriented distance and the second oriented distance includes defining a global gamut center by calculating an average of chromaticity values ​​of color points at a first plurality of vertices of the global common gamut, extending a line between the global gamut center and the selectable target chromaticity, projecting the line onto the global common gamut, and calculating a first oriented distance between the selectable target chromaticity and a first point where the line intersects a transition boundary of the interior region, and a second oriented distance between the selectable target chromaticity and a second point where the line intersects a straight edge of the global common gamut between two adjacent vertices.

[0013] In an exemplary embodiment, the method further includes determining not to modify the selectable target chromaticity if the selectable target chromaticity is within the interior region.

[0014] In an exemplary embodiment, the method further includes determining to modify the selectable target chromaticity if the selectable target chromaticity is outside the interior region.

[0015] In an exemplary embodiment, the method further includes modifying the selectable target chromaticity to a modified target chromaticity within the light fixture gamut and outside the global common gamut based at least in part on a relationship between the calculated first directional distance and the second directional distance.

[0016] In an exemplary embodiment, the method further includes calculating a light fixture gamut, where the light fixture gamut at least partially encloses the global common gamut, where the light fixture gamut includes a third plurality of vertices; and modifying the first color space area into a second color space area, where the first color space area is defined by straight edges of the global common gamut, a transition boundary of the interior region, and a line extending between endpoints of the straight edges and the transition boundary, and where the second color space area is defined by the transition boundary of the interior region and two adjacent vertices of the third plurality of vertices of the light fixture gamut.

[0017] In general, in another aspect, a system is provided that includes a plurality of LED-based light sources configured to generate light defined by a light fixture gamut in a color space, and a controller. The controller is configured to receive or set a selectable target chromaticity within a global common gamut of the color space, determine that the selectable target chromaticity is between two adjacent vertices of a first plurality of vertices of the global common gamut, define an interior region within the global common gamut at a transition boundary, and calculate a first oriented distance between the selectable target chromaticity and the transition boundary of the interior region and a second oriented distance between the selectable target chromaticity and a straight edge of the global common gamut between the two adjacent vertices. The controller is further configured to modify the selectable target chromaticity to a modified target chromaticity within the light fixture gamut based at least in part on the calculated first oriented distance and the second oriented distance, or generate an activation signal to drive the plurality of LED-based light sources based on the selectable target chromaticity based at least in part on the calculated first oriented distance and the second oriented distance.

[0018] In an exemplary embodiment, the controller is further configured to generate another activation signal for driving the plurality of LED-based light sources based on the modified target chromaticity.

[0019] In an exemplary embodiment, the light fixture color gamut at least partially encloses the global common color gamut, the light fixture color gamut being defined by the colorimetric characteristics of light emitted by multiple LED-based light sources.

[0020] In an exemplary embodiment, the modified target chromaticity is outside the global common color gamut.

[0021] It should be understood that all combinations of the above-mentioned concepts, and additional concepts discussed in more detail below (provided such concepts are not mutually inconsistent), are contemplated as part of the inventive subject matter disclosed herein, and in particular, all combinations of claimed subject matter described at the end of this disclosure are contemplated as part of the inventive subject matter disclosed herein. [Brief description of the drawings]

[0022] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosure. [Figure 1] FIG. 1 shows a schematic block diagram illustrating a color lighting system according to the present disclosure. [Diagram 2] FIG. 2 shows a CIE chromaticity diagram including a single specific lighting fixture gamut according to the present disclosure. [Diagram 3] FIG. 3 shows the CIE chromaticity diagram of FIG. 2 including two specific lighting fixture gamuts according to this disclosure. [Figure 4] FIG. 4 illustrates a CIE chromaticity diagram including a specific lighting fixture gamut and a global common gamut within the lighting fixture gamut according to the present disclosure. [Figure 4A] FIG. 4A illustrates another CIE chromaticity diagram including another specific lighting fixture gamut and another global common gamut that is not entirely within the lighting fixture gamut according to the present disclosure. [Diagram 5] FIG. 5 shows the CIE chromaticity diagram of FIG. 4 including the inner region used to precisely target the white point according to the present disclosure. [Figure 5A] FIG. 5A shows another CIE chromaticity diagram that includes another inner region that may be used to precisely target the white point according to the present disclosure. [Figure 6] FIG. 6 is a flow chart illustrating a method for controlling an LED-based lighting product to produce accurate white and saturated colors in accordance with the present disclosure. [Figure 7] FIG. 7 illustrates an exemplary CIE chromaticity diagram showing target chromaticity points within an interior gamut according to this disclosure. [Figure 8] FIG. 8 illustrates an example CIE chromaticity diagram showing target chromaticity points within the global common color gamut but outside the inner region according to this disclosure. [Figure 8A] FIG. 8A shows an enlarged view of general area 8A in FIG. [Figure 9] FIG. 9 illustrates another example CIE chromaticity diagram showing additional target chromaticity points within the global common color gamut but outside the inner region according to this disclosure. [Figure 9A] FIG. 9A shows an enlarged view of general area 9A in FIG. [Figure 9B] FIG. 9B illustrates another exemplary method for stretching a target point according to the present disclosure. [Figure 10] FIG. 10 illustrates an example CIE chromaticity diagram showing an example lighting fixture gamut, an example global common gamut, and example non-overlapping interior regions according to this disclosure. [Figure 11] FIG. 11 illustrates the example CIE chromaticity diagram of FIG. 10 showing a first color space area according to this disclosure. [Figure 12] FIG. 12 illustrates the example CIE chromaticity diagram of FIG. 10 showing a second color space area according to this disclosure. [Figure 13] FIG. 13 illustrates the example CIE chromaticity diagram of FIG. 10 showing a third color space area according to this disclosure. [Figure 14] FIG. 14 illustrates an example CIE chromaticity diagram showing a first modified color space area based on the first color space area shown in FIG. 11 according to this disclosure. [Figure 15] FIG. 15 illustrates an example CIE chromaticity diagram illustrating a second modified color space area based on the second color space area shown in FIG. 12 according to this disclosure. [Figure 16] FIG. 16 illustrates an example CIE chromaticity diagram illustrating a third modified color space area based on the third color space area shown in FIG. 13 according to this disclosure. [Figure 17]FIG. 17 illustrates an exemplary CIE chromaticity diagram showing a central portion of a lighting fixture gamut optimized for color accuracy and an outer portion of a lighting fixture gamut optimized for saturation in accordance with the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] The present disclosure describes various embodiments of systems and methods for controlling one or more LED-based lighting products to provide accurate white / pastel color points and saturated color points without requiring settings to be changed or reconfiguration of the lighting fixture. Applicant recognizes and understands that it would be beneficial to provide accurate shades of white and fully saturated colors within the same system without requiring reconfiguration. A particular goal of the use of certain embodiments of the present disclosure is to define an interior region of the operating gamut to accurately target white / pastel colors while maintaining access to the entire gamut of the lighting fixture to also provide saturated colors.

[0024] Referring to FIG. 1, a schematic block diagram illustrating a color lighting system 100 according to the present disclosure is shown, including light sources 102A-C. The light sources 102A-C are three narrow band, essentially monochromatic light sources, e.g., red, green, and blue light sources. The color lighting system 100 also includes a light source interface 104, a controller 106 including a microprocessor 108, a memory 110, and an external interface 112. The color lighting system 100 can be powered via an external power connection 113, or an internal power source, such as a battery, can be used. The light sources 102A-C shown in FIG. 1 can be provided in a single lighting fixture. However, it should be understood that any number of light sources and corresponding light fixtures can be included in the color lighting system 100. The microprocessor 108 of the controller 106 is configured to receive a request for a selectable target chromaticity via the external interface 112 and, after processing, output one or more control signals to drive the light sources 102A-C via the light source interface 104. The light sources 102A-C are intensity controllable (dimmable) and can be controlled to output light of their respective colors at relative intensities between 0 and 100%.

[0025] Although FIG. 1 shows red, blue, and green light sources 102A-C, it should be understood that any light source color can be used. Furthermore, it should be understood that any suitable number of light sources can be used, for example, additional or fewer light sources can be used. To illustrate the color generation capability of a lighting fixture including light sources 102A-C, FIG. 2 shows a CIE chromaticity diagram, or color space or color system, including a triangular lighting fixture gamut 114. In alternative embodiments, the lighting fixture gamut can have a different shape (e.g., a polygonal shape). A lighting fixture including light sources 102A-C is configured to generate and mix red, green, and blue light in various combinations and proportions to generate light of different temperatures. The light emitted by each light source exhibits unique colorimetric characteristics that can be mapped to corresponding points 116, 118, and 120 having x and y chromaticity coordinates on the CIE chromaticity diagram. The x and y chromaticity coordinates 116, 118, and 120 of the light sources 102A-C define the unique color gamut of the lighting fixture. The lighting fixture gamut 114 specifies all possible colors (or color temperatures) that can be produced by the lighting fixture through additive color mixing. The x and y chromaticity coordinates depend only on the hue and saturation and are independent of the amount of luminous energy. The x and y chromaticity coordinates near the boundary of the lighting fixture gamut 114 are more saturated, while the colors become less saturated as they move from the boundary toward the center point of the lighting fixture gamut 114.

[0026] As mentioned above, due to manufacturing variations inherent in LED technology, no two LEDs are exactly the same. Thus, different lighting fixtures that include red, green, and blue light sources will have different lighting fixture color gamuts. Figure 3 shows the CIE chromaticity diagram of Figure 2 with two unique lighting fixture color gamuts 114 and 122.

[0027] Applicant recognizes and understands that multiple lighting units, each configured to generate variable color light or variable color temperature white light based on additive color mixing of multiple light sources, may not be able to generate light of substantially the same range of colors or color temperatures even if the lighting units employ generally similar light sources. When two or more such lighting units receive instructions (e.g., lighting commands) intended to cause the generation of light of the same color (or color temperature) from the multiple units, each lighting unit may actually generate light of a perceptually different color (or color temperature) based at least in part on their respective different color gamuts (e.g., as determined by the different chromaticity coordinates of the respective "same color" sources). When two or more such lighting units are deployed together, for example, as components of a lighting system (e.g., to provide general lighting or other types of lighting in parallel in a given environment), inconsistent, unpredictable, and generally undesirable artifacts may lead to the generation of variable color light or variable color temperature white light.

[0028] In order to consistently and predictably generate variable color light or variable color temperature white light among multiple lighting units, the light sources of multiple lighting units can be controlled with reference to a global common color gamut 124 and an interior region 126 as shown in Figs. 4, 4A, and 5. The global common color gamut 124 can include all of the color points in a color space that are common to two or more lighting units. As shown in Fig. 4, the global common color gamut 124 can be completely enclosed within each fixture color gamut in the lighting system installation. As shown in Fig. 4A, the global common color gamut 124 can alternatively not be completely enclosed within each fixture color gamut in the lighting system installation. In Fig. 4A, vertices 125A and 125B are inside the color gamut 114, while vertex 125C is outside the color gamut 114. The global common color gamut 124 can be generated in any suitable manner. One exemplary method of generating the global common gamut 124 involves determining the color gamuts that fall within each fixture gamut in the lighting system installation, whether the gamut is a three-sided polygon, a four-sided polygon, or some other shape. For purposes of illustrating this disclosure, a triangular global common gamut as shown in Figures 4, 4A, and 5 is used, although any shape can be used. The global common gamut 124 is a polygon formed by a number of straight sides S1-S3 and a number of vertices 125A-C. Each vertex 125A-C of the global common gamut 124 is located where two adjacent straight sides of the number of straight sides intersect.

[0029] As shown in FIG. 5, a smaller internal region 126 is created within the global common gamut 124 to precisely target the white point. The internal region 126 is defined by the same number of vertices and boundaries connecting these vertices as used to define the global common gamut. In FIGS. 4, 4A, and 5, the global common gamut 124 has three vertices 125A-C, and as shown in FIG. 5, the internal region 126 also has three vertices 127A-C. However, it should be understood that both may have additional vertices. In an exemplary embodiment, each vertex of the internal region 126 is collinear with the center of the global common gamut 124 and the vertices of the global common gamut 124 as shown in FIG. 5. FIG. 5 shows lines L1-L3 figuratively emanating from the center, passing through the vertices 127A-C of the internal region 126, and terminating at the vertices 125A-C of the global common gamut 124 to illustrate this collinearity.

[0030] In other exemplary embodiments, the vertices of the interior region 226 need not have the same collinearity as shown in FIG. 5 and described above. For example, in FIG. 5A, the interior region 226 is defined by vertices 227A-C and a boundary connecting vertices 227A-C. The interior region 226 has the same number of vertices as used to define the global common gamut 224. However, the vertices of the global common gamut 224 and the vertices of the interior region 226 are not collinear with the center of the global common gamut 224. Line L4 extends from vertex 225A of the global common gamut 224 through vertex 227A of the interior region 226 to the ends of lines L5 and L6. As shown in FIG. 5A, line L5 terminates at line L4 at a point closer to vertices 227A and 225A than the point where line L6 terminates at line L4. However, in alternative embodiments, line L5 may terminate at line L4 at a point farther from vertices 227A and 225A than the point at which line L6 terminates at line L4. Line L5 extends from vertex 225B of the global common gamut 224, through vertex 227B of the interior region 226, to a point along line L4. In alternative embodiments, line L5 may terminate at an endpoint of line L4. Line L6 extends from vertex 225C of the global common gamut 224, through vertex 227C of the interior region 226, to an endpoint of line L4. However, in alternative embodiments, line L6 may terminate at a point along line L4. In FIG. 5A, none of lines L4-6 extend through or to the center of the global common gamut 224. However, it should be understood that any other suitable configurations are contemplated, so long as vertices 225A and 227A are connected along line L4, vertices 225B and 227B are connected along line L5, and vertices 225C and 227C are connected along line L6. The portion of lines L4-L6 between global common gamut 224 and interior region 226 defines a color space area, which will be described below.

[0031] The interior region 126 must be completely encompassed by the global common color gamut 124, but should also be large enough to encompass all the white points that are desired to be accurately targeted. The center of the global common color gamut 124 is obtained by averaging the x and y chromaticity coordinates of the vertices 125A-C of the global common color gamut 124. Any selectable target chromaticity within the interior region 126 that is received by the microprocessor 108 of the controller 106 is accurately targeted. In other words, any such selectable target chromaticity that is within the interior region 126 is used as is, and the microprocessor 108 stops further processing, as described further below. In an exemplary embodiment, lighting commands received by the multiple lighting units may be appropriately processed in each lighting unit based on a predetermined relationship between the lighting command and the interior region 126.

[0032] To generate similarly saturated colors among multiple lighting units, the light sources 102A-C can be controlled with reference to the individual fixture gamuts as well as the global common gamut 124 and the interior region 126, as described further below. As used herein, the term "saturated" refers to the amount of saturation in any color that is within the individual fixture gamut 114 and outside the interior region 126. Those colors that are outside the interior region 126 are more saturated (i.e., less white) than those that are within the interior region 126. The term "saturated" refers to all colors, including colors that are on the boundary of the individual fixture gamuts and colors that are within the boundary but outside the boundary of the interior region 126. The term "fully-saturated" is used to refer to colors that are on the boundary of the global common gamut 124 or the light fixture gamut 114 in the appropriate context. In other words, color points designated on the boundary of the global common color gamut 124 before the microprocessor 108 makes modifications in accordance with the present disclosure can be considered "fully saturated" points. Color points on the boundary of the light fixture color gamut 114 after the microprocessor 108 makes modifications in accordance with the present disclosure can be considered "fully saturated" points.

[0033] As used herein for purposes of this disclosure, the term "LED" should be understood to include any electroluminescent diode or other type of carrier injection / junction-based system capable of generating radiation in response to an electrical signal. Thus, the term LED includes, but is not limited to, various semiconductor-based structures, light-emitting polymers, electroluminescent strips, and the like that emit light in response to an electric current. The term LED refers to all types of light-emitting diodes (including semiconductor and organic light-emitting diodes) that may be configured to generate radiation in one or more of various portions of the infrared spectrum, the ultraviolet spectrum, and the visible spectrum (which generally includes emission wavelengths from about 400 nanometers to about 700 nanometers).

[0034] It should also be understood that the term LED does not limit the type of physical and / or electrical packaging of an LED. For example, as discussed above, an LED may refer to a single light emitting device having multiple dies (e.g., which may or may not be individually controllable) each configured to emit a different radiation spectrum. An LED may also be associated with a phosphor that is considered an integral part of the LED (e.g., some type of white LED). In general, the term LED may refer to packaged LEDs, unpackaged LEDs, surface mounted LEDs, chip-on-board LEDs, T-packaged LEDs, radial packaged LEDs, power packaged LEDs, LEDs that include some type of housing and / or optical elements (e.g., diffusing lenses), and the like. In general, the term LED may refer to packaged LEDs, unpackaged LEDs, surface mounted LEDs, chip-on-board LEDs, T-packaged LEDs, radial packaged LEDs, power packaged LEDs, LEDs that include some type of housing and / or optical elements (e.g., diffusing lenses), and the like.

[0035] The term "light source" includes, but is not limited to, LED-based light sources (including one or more LEDs as defined above), incandescent light sources (e.g., filament lamps, halogen lamps), fluorescent sources, phosphorescent sources, high intensity discharge sources (e.g., sodium vapor lamps, mercury vapor lamps, and metal halide lamps), lasers, other types of electroluminescent sources, pyroluminescent sources (e.g., flames), candle luminescent sources (e.g., gas mantle sources, carbon arc radiation sources), photoluminescent sources (e.g., gaseous discharge sources), cathode luminescent sources using electronic satiation, galvanoluminescent sources, crystallo-luminescent sources, kine-luminescent sources, thermoluminescent sources, triboluminescent sources, sonoluminescent sources, radioluminescent sources, and light emitting polymer luminescent sources. This should be understood to refer to any one or more of a variety of radiation sources, including polymers.

[0036] The terms "illumination unit" and "lighting fixture" as used herein refer to an apparatus that includes one or more light sources of the same or different types. A given lighting fixture may have any suitable mounting configuration, enclosure / housing configuration and shape, and / or electrical and mechanical connection configuration for the light sources. Furthermore, a given lighting fixture may also be coupled to and / or packaged with other components, including other components related to the operation of the light sources (e.g., control circuitry). An "LED-based lighting fixture" refers to a lighting fixture unit that includes one or more LED-based light sources as described above, alone or in combination with other non-LED-based light sources.

[0037] The term "controller" as used herein refers to various devices associated with the operation of one or more light sources. The controller can be implemented with dedicated hardware using one or more microprocessors that are programmed using software to perform various functions discussed herein, or as a combination of dedicated hardware to perform some functions and a programmed microprocessor and associated circuitry to perform other functions. Examples of controller components that may be employed in various embodiments of the present disclosure include, but are not limited to, microprocessors, application specific integrated circuits (ASICs), and field-programmable gate arrays (FPGAs).

[0038] In various implementations, the controller may be associated with one or more storage media (generally referred to herein as "memory"; e.g., volatile and non-volatile computer memory such as RAM, PROM, EPROM, and EEPROM, floppy disks, compact disks, optical disks, magnetic tapes, etc.). In some implementations, these storage media may be encoded with one or more programs that, when executed on one or more processors and / or controllers, perform at least a portion of the functions discussed herein. The various storage media may be fixed within a processor or controller, or may be portable such that one or more programs stored on those storage media can be loaded into a processor or controller to implement various aspects of the invention discussed herein.

[0039] The process used to target accurate white point and saturated colors in color lighting system 100 will now be described with reference to Figure 6. It should be understood that various embodiments may not include each of the steps described with reference to Figure 6, and the order of the steps is not limited, i.e., in other embodiments, the process may be performed in an order different from that described without departing from the scope of the present disclosure.

[0040] Before the controller 106 of the color light system 100 can determine whether to output one or more control signals to drive the light sources 102A-C via the light source interface 104, the lighting fixture gamut 114, the global common gamut 124 and the interior region 126 must be defined in step S602.

[0041] At least one lighting fixture color gamut 114 can be predefined and preprogrammed by a lighting fixture manufacturer and stored in memory 110. Alternatively, the lighting fixture color gamut can be calculated using any suitable tool to measure the chromaticity of the lighting fixture's light source and stored in memory 110. For example, the spectral power distribution of the light source can be measured and mapped to a color space, such as the CIE chromaticity diagram. Such data can then be stored in memory 110. In some embodiments, the fixture color gamut is temperature dependent and therefore can be calculated and recalculated as needed.

[0042] The global common color gamut 124 of a lighting fixture or a system including multiple lighting fixtures can also be predefined and preprogrammed by a manufacturer and stored in the memory 110. Alternatively, a professional lighting installer or another user can define a color gamut that includes color points common to all lighting fixtures in the system and store it in the memory 110. In an exemplary embodiment, the global common color gamut can include most, but not all, color points common to all lighting fixtures in the system. In certain cases where the global common color gamut is not completely included within the color gamut of a light fixture, any suitable area mapping can be used to modify the color points selected within the global common color gamut and outside the light fixture color gamut. In other embodiments, a computer program product can be configured to determine and store in the memory 110 a color gamut that includes color points common to all or most lighting fixtures in the system. The center of the global common color gamut 124 can also be defined by a manufacturer or as described herein and stored in the memory 110.

[0043] The interior region 126 of the global common color gamut 124 can be predefined and preprogrammed by a manufacturer and stored in the memory 110. Alternatively, a professional lighting installer or other user can define the interior region 126 to customize all the white points to be precisely targeted. In other embodiments, a computer program product can be configured to determine and store in the memory 110 the interior region 126 based on the input(s) of all the white points to be precisely targeted.

[0044] Once the lighting fixture gamut 114, global common gamut 124 and inner region 126 are defined, a user-selectable target chromaticity can be received or set via the external interface 112 in step S604. For example, a user can input the target chromaticity in the form of red, green and blue values ​​as numbers ranging from 0 to 255 via the external interface, and such values ​​can be processed according to the DMX-512 protocol (in which 8 bits are employed to specify the relative intensity of each light source (i.e., 24-bit color control)). However, it should be understood that virtually any scale may be employed to specify the relative amount of each light source in a given lighting unit to generate a resulting color or color temperature of light in any of the various lighting command formats. In an exemplary embodiment, the DMX values ​​can be weighted values ​​and a dimming curve may be employed.

[0045] After the user-selectable target chromaticity is received by the microprocessor 108, in step S606, it is determined that the target chromaticity is between two adjacent vertices of the global common gamut 124. For example, referring to FIG. 5 and FIG. 7, the microprocessor 108 can divide the global common gamut 124 into three regions based on the number of vertices of the global common gamut, and determine which region the target chromaticity is located in. Since the global common gamut 124 has red, green, and blue points, the global common gamut 124 can be divided into regions RG, GB, and BR as shown in FIG. 5 using the above-mentioned lines L1-L3. The user-selectable target chromaticity can be in any of the three regions. To determine which region the target chromaticity is located in, an equation for each of the lines L1-L3 can be derived, and a directional distance between the target chromaticity and each line can be calculated to determine whether the target chromaticity is above or below each line (or outside or inside each line relative to the center point). Since these lines do not change, they can be calculated when the global common color gamut 124 is defined and stored in memory 110. The following formulas can be used to define each line: TIFF0007664944000001.tif3246, where a represents the slope and b represents the y-intercept. Referring to Figure 5, the above formula (1) defines line L2, the above formula (2) defines line L1, and the above formula (3) defines line L3.

[0046] Once the microprocessor 108 determines which region the target chromaticity is located in, the microprocessor 108 can ignore other regions in step S608. Referring to Figure 7, in an exemplary embodiment, the target chromaticity point P1 is between the center-green line (e.g., line L1) and the center-blue line (e.g., line L3) in the GB region, and the microprocessor 108 focuses on this region. The microprocessor 108 can then use the equation y = ax + b to define the transition boundary 130 of the interior region 126 between vertices 127A and 127C and the boundary 132 of the global common gamut 124 between vertices 125A and 125C.

[0047] Thereafter, the microprocessor 108 can calculate the directional distance between the target chromaticity point P1 and each of the boundaries 130 and 132 in step S610. For example, the microprocessor 108 can calculate d P-b1 and d represents the distance between the target chromaticity point P1 and the boundary 132 (or b2). P-b2 These distances can be defined as the shortest distance between the target chromaticity point and the respective boundary. The boundaries 130 and 132 are not necessarily parallel, but in all practical applications they will be approximately parallel. The use of the shortest distance is a way of treating them as equally valid slopes that may or may not be parallel. These boundaries 130 and 132 will not be perpendicular in practical implementations. The following formulas can be used to calculate the directional distances as described above: It should be appreciated that since K is a function of a (e.g., a cosine function), there are six possible values ​​of K: two for boundaries 130 and 132 as described herein, two more for the boundary of the global common gamut and interior region between vertices 125A and 127A and vertices 125B and 127B (e.g., in region RG), and two more for the boundary of the global common gamut and interior region between vertices 125B and 127B and vertices 125C and 127C (e.g., in region BR). Thus, d P-b1 and d P-b2 The calculation of uses two different values ​​of K, i.e., a value for b1 and a value for b2. K is a scale factor known in advance and can be pre-calculated as a factory setting and thus can be stored in the memory 110. Also, it should be understood that the "±" used in the formula for K is to mean that the sign representing the desired direction should be selected such that positive directional distances are directed away / away from the center 128 and negative directional distances are directed towards / closer to the center 128. For example, in cyan or yellow, positive distances are directed outward from the center, while in purple, positive distances are directed inward towards the center. The appropriate sign should be used such that positive directional distances are directed away / away from the center 128.

[0048] It should be understood that the directional distance can also be determined in other ways. For example, a line can be drawn connecting the center of the global common gamut as described herein to the target chromaticity point P1. The line from the center to point P1 can be projected onto the global common gamut. The distance d P-b1 and d P-b2 can be calculated using a single projection line, which may be particularly suitable when the global common gamut and the inner region are parallel or substantially parallel.

[0049] Based on the directional distance, the microprocessor 108 can determine in step S612 whether the target chromaticity point P1 is within the transition boundary 130 of the internal region 126 or between the transition boundary 130 of the internal region 126 and the boundary 132 of the global common gamut 124. If the target chromaticity point P1 is within the transition boundary 130 of the internal region 126 (as shown in FIG. 7), the user has selected a white point that can be targeted accurately. In this case, the target chromaticity point P1 is within both b1 and b2 relative to the center, so the directional distance d P-b1 and d P-b2 Both are negative. That is, the directional distance d P-b1 and d P-b2 If both directional distances are negative, then both boundaries b1 and b2 are outside the target chromaticity point P1 relative to the center of the global common gamut. If both directional distances are negative, then the microprocessor 108 uses the input values ​​as is to output control signals to the light sources 102A-C in step S614A. In other words, the final target chromaticity is the requested target chromaticity. If the target chromaticity point is within the transition boundary 130 of the inner region 126, no further processing is required. As shown in FIG. 7, the input DMX values ​​for R, G, and B using the global common gamut 124 represent a point P1 that is inside both the global common gamut 124 and the inner region 126. Thus, the color lighting system 100 is optimized for accuracy using the control parameters of the inner region 124.

[0050] On the other hand, if the target chromaticity point is between the transition boundary 130 of the interior region 126 and the boundary 132 of the global common gamut 124, the microprocessor 108 can output modified control signals to the light sources 102A-C as described further below. As shown in Figures 8 and 8A, the input DMX values ​​for R, G, and B using the global common gamut 124 can represent a point P2 that is between the transition boundary 130 of the interior region 126 and the boundary 132 of the global common gamut 124. Because point P2 is outside the interior region 126, the user represents an intent for a more saturated color, and the microprocessor 108 can stretch the point to the modified target chromaticity. Based on the value of point P2 represented in Figures 8 and 8A, the directional distance d P-b1 becomes positive, and the directed distance d P-b2 will be negative because point P2 is outside (or above) transition boundary 130 but inside (or below) boundary 132 relative to center point 128. In other words, target point P2 is above transition boundary 130 and below boundary 132. If at least one directional distance is positive, microprocessor 108 determines in step S614B that the input values ​​must be modified in an outward direction toward boundary 132 of global common gamut 124 and lighting fixture gamut 114. An outwardly modified input value specifies a more saturated color than the originally requested color.

[0051] To determine how far to stretch the target chromaticity point outward, the microprocessor 108 can calculate, in step S616, the point's fractional distance between the boundaries 130 and 132, represented by the ratios R and 1-R. The ratio R can be expressed in terms of the absolute value of the directional distance as follows: TIFF0007664944000003.tif1752

[0052] The ratios R and 1-R, when added together, equal 1 or 100%. The ratio R represents whether the target chromaticity point is closer to the transition boundary 130 of the interior region 126 or to the boundary 132 of the global common gamut 124. If the point is closer to the transition boundary 130, the ratio R is larger because the distance between the point and the boundary 132 is larger than the distance between the point and the transition boundary 130. If the point is closer to the boundary 132, the ratio R is smaller because the distance between the point and the boundary 132 is smaller than the distance between the point and the transition boundary 130. If the point is closer to the transition boundary 130 of the interior region 126, the weighted average favors chromaticities that are closer to the color point targeted by the user. In contrast, if the point is closer to the boundary 132 of the global common gamut 124, the weighted average disfavors chromaticities that are closer to the color point targeted by the user. Based on the location of point P2, the microprocessor 108 stretches the point to the modified target chromaticity MP2, as shown in Figures 8 and 8A. In Figures 8 and 8A, the modified target chromaticity MP2 is adjacent to and slightly outside the target chromaticity point P2. The modified target chromaticity MP2 in Figures 8 and 8A is still within the global common gamut 124.

[0053] Based on the location of point P3, the microprocessor 108 stretches the point to a modified target chromaticity MP3, as shown in Figures 9 and 9A. The modified target chromaticity MP3 in Figure 9 is no longer within the global common gamut 124. Instead, the modified target chromaticity MP3 is stretched outward beyond the global common gamut 124 into a portion of the lighting fixture gamut 114 that does not overlap with the global common gamut 124. Based on the location of point P4, the microprocessor 108 stretches the point P4 to a modified target chromaticity MP4 that is outside the global common gamut 124 and within the lighting fixture gamut 114, as shown in Figures 9 and 9A. Figures 9 and 9A show how slight differences in saturation at the user-selected target points (P3 vs. P4) can result in greatly different saturation at the modified chromaticity points (MP3 vs. MP4). In other words, because P4 is slightly more saturated than P3, the modified point MP4 is more saturated than the modified point MP3 due to the stretching performed by the microprocessor 108 as described herein. In an exemplary embodiment, the modified target chromaticity can be determined from the input dimming ratio as applied to the color gamut of the light fixture.

[0054] If the R, G, and B input values ​​include one or more values ​​equal to zero, this will result in the ratio R mentioned above being zero and the microprocessor 108 will target a fully-saturated color limited only by the optical capability of the LEDs of the lighting unit or fixture. On the other hand, if the input values ​​represent a less saturated color, the ratio R will be larger and the microprocessor will blend between the requested color and the most saturated possible color.

[0055] In an exemplary embodiment, when the user changes the DMX input values, the fixtures respond gradually to the changes by blending between precise white / pastel colors and saturated colors.

[0056] In an exemplary embodiment, the microprocessor 108 can alternatively determine how far to stretch the target chromaticity point outward. Instead of using the fractional distance of the point between the boundaries 130 and 132 as described above, a line L6 can be drawn connecting the center 128 of the global common gamut to the target point P5, and the line can be projected onto the global common gamut 124, as shown in FIG. 9B. As shown in FIG. 9B, the target point P5 is projected onto the global common gamut 124 by distances A and B and distance d P-b1 and d P-b2 , and distance A is measured between vertex 127A of interior region 126 and the point where line L6 intersects transition boundary 130 of interior region 126. Distance B is measured between vertex 127C of interior region 126 and the point where line L6 intersects transition boundary 130 of interior region 126. Microprocessor 108 can calculate a stretched target chromaticity (e.g., MP5) using the same ratios A and B, but as applied to transition boundary 130 and fixture gamut line 114A. In other words, target point P5 is a weighted average of the endpoints of transition boundary 130 and boundary 132. The stretched target uses the same weighted average, but as applied to transition boundary 130 and fixture gamut boundary 114A.

[0057] In an exemplary embodiment, the process of stretching the target chromaticity points outward involves stretching a color space area 134 in the global common gamut 124. For example, FIG. 10 shows an interior region 126 and an area 134 between the interior region 126 and the exterior of the global common gamut 124. As described above, the interior region 26 is always constant, so all fixtures can accurately target the required points within the area 126. The required points between the interior region 126 and the exterior of the global common gamut 124 can be stretched as described above to create saturated colors. In an exemplary embodiment, the color space area 134 or a portion thereof can also be stretched.

[0058] As shown in FIGS. 11-13, the area 134 can be divided into sub-areas 136, 138, and 140. In an exemplary embodiment, the microprocessor 108 can divide the area 134 into three sub-areas based on the number of vertices of the global common gamut 124 and the inner region 126. For example, this subdivision can be performed after or at the same time that the microprocessor 108 determines in which region the target chromaticity is located as described above. For example, the sub-area 136 is a portion of the global common gamut 124 that does not overlap with the inner region 126 and is located between lines L1 and L3 in FIG. 11. Similarly, the sub-area 138 is a portion of the global common gamut 124 that does not overlap with the inner region 126 and is located between lines L1 and L2 in FIG. 12. Also, the sub-area 140 is a portion of the global common gamut 124 that does not overlap with the inner region 126 and is located between lines L2 and L3 in FIG. 13.

[0059] 14-16, subareas 136, 138, and 140 can be modified into subareas 142, 144, and 146, respectively. For example, in FIG. 14, subarea 136, also referred to in this disclosure as color space area, can be modified such that the outer boundary of subarea 136 is limited only by the optical capabilities of the LEDs of the lighting unit or fixture. Subarea 136 can be modified into subarea or color space area 142 if the target chromaticity point is determined to be within color space area 136. Referring back to FIG. 11, color space area 136 is defined by transition boundary 130 of interior region 126, boundary 132 of global common gamut 126, and portions of lines L1 and L3 extending between center 128 and vertices 125A and 125C of global common gamut 126. The color space area 142 in FIG. 14 is defined by the transition boundary 130 of the interior region 126 and two adjacent vertices 150 and 152 of the multiple vertices 150 , 152 , 154 of the lighting fixture gamut 114 .

[0060] Similarly, color space areas 138 and 140 can be modified, if desired, such that their outer boundaries are limited only by the optical capabilities of the LEDs of the lighting unit or fixture. For example, color space area 138 in Figure 12 can become color space area 144 in Figure 15 if the target chromaticity point is determined to be within color space area 138, and color space area 140 in Figure 13 can become color space area 146 in Figure 16 if the target chromaticity point is determined to be within color space area 140. Figure 17 shows modified color space areas 142, 144, and 146 in combination for interior region 126.

[0061] Advantageously, the systems and methods described herein enable users to easily select the correct white / pastel color point and saturated colors within an LED-based light system without changing settings or reconfiguring the light fixture.

[0062] While several inventive embodiments have been described and illustrated herein, those skilled in the art will readily envision various other means and / or structures for performing the functions described herein and / or obtaining one or more of the results and / or advantages thereof, and such variations and / or modifications are deemed to be within the scope of the inventive embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will vary depending on the particular application in which the teachings of the present invention are used. Those skilled in the art will recognize, or be able to ascertain, using no more than routine experimentation, many equivalents to the specific inventive embodiments described herein. Thus, the above-described embodiments are presented by way of example only, and it will be understood that, within the scope of the appended claims and their equivalents, inventive embodiments may be practiced other than as specifically described and claimed. Inventive embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, and / or method described herein. Furthermore, any combination of two or more such features, systems, articles, materials, kits, and / or methods is within the scope of the present disclosure, provided that such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

Claims

1. 1. A method for driving a plurality of LED-based light sources at selectable target chromaticities in a color space, the method comprising: receiving or setting the selectable target chromaticity within a global common gamut of the color space, the global common gamut including one or more color points in the color space that are common to two or more of the plurality of LED-based light sources; determining that the selectable target chromaticity is between two adjacent vertices of a first plurality of vertices of the global common color gamut; defining an interior region within said global common color gamut at a transition boundary; calculating a first oriented distance between the selectable target chromaticity and the transition boundary of the interior region and a second oriented distance between the selectable target chromaticity and a straight edge of the global common gamut between the two adjacent vertices; modifying the selectable target chromaticity to a modified target chromaticity within a light fixture gamut based at least in part on the calculated first directional distance and the second directional distance, the modification being outward toward a boundary of the global common gamut and the light fixture gamut, the light fixture gamut including color points produced by at least one of the plurality of LED-based light sources; or generating activation signals for driving the plurality of LED-based light sources based on the selectable target chromaticity, the selectable target chromaticity being within the interior region; and

2. 2. The method of claim 1 , further comprising: calculating a light fixture gamut, the light fixture gamut at least partially enclosing the global common gamut, the calculating the light fixture gamut comprising determining or receiving colorimetric data indicative of colorimetric characteristics of light emitted by the plurality of LED-based light sources, the colorimetric characteristics defining the light fixture gamut.

3. The method of claim 2 , wherein the light fixture color gamut completely encloses the global common color gamut.

4. The step of defining the interior region comprises: defining a global gamut center by calculating an average of chromaticity values ​​of color points at the first plurality of vertices of the global common gamut; extending a line between the global gamut center and each of the first plurality of vertices of the global common gamut; positioning a second plurality of vertices such that each vertex of the second plurality of vertices intersects one of the lines extending between the global gamut center and each of the first plurality of vertices, the transition boundary connecting the second plurality of vertices; The method of claim 1 , comprising:

5. The step of defining the interior region comprises: defining a global gamut center by calculating an average of chromaticity values ​​of color points at the first plurality of vertices of the global common gamut; positioning a second plurality of vertices such that each vertex of the second plurality of vertices is between the global gamut center and a respective vertex of the first plurality of vertices; connecting the transition boundaries between the second plurality of vertices; Including, The method of claim 1 , wherein the first plurality of vertices and the second plurality of vertices are not collinear with the global gamut center.

6. The step of determining that the selectable target chromaticity is between two adjacent vertices of a first plurality of vertices of the global common color gamut includes: defining a global gamut center by calculating an average of chromaticity values ​​of color points at the first plurality of vertices of the global common gamut; extending a line between the global gamut center and each of the first plurality of vertices of the global common gamut; determining that the selectable target chromaticity is between two adjacent lines extending between the global gamut center and the first plurality of vertices of the global common gamut by calculating a third oriented distance and a fourth oriented distance between the selectable target chromaticity and a line extending between the global gamut center and the two adjacent vertices of the global common gamut; The method of claim 1 , comprising:

7. The step of calculating the first directional distance and the second directional distance includes: defining a global gamut center by calculating an average of chromaticity values ​​of color points at the first plurality of vertices of the global common gamut; extending a line between the global gamut center and the selectable target chromaticity; projecting said line onto said global common color gamut; calculating the first oriented distance between the selectable target chromaticity and a first point where the line intersects the transition boundary of the interior region, and the second oriented distance between the selectable target chromaticity and a second point where the line intersects the straight edge of the global common gamut between the two adjacent vertices; The method of claim 1 , comprising:

8. The method of claim 1 , comprising determining to modify the selectable target chromaticity if the selectable target chromaticity is outside the interior region.

9. 9. The method of claim 8, further comprising modifying the selectable target chromaticity to the modified target chromaticity within the light fixture gamut and outside the global common gamut based at least in part on a calculated relationship between the first directional distance and the second directional distance.

10. The method comprises: calculating the light fixture gamut at least partially enclosing the global common gamut, the light fixture gamut including a third plurality of vertices; modifying a first color space area into a second color space area, the first color space area being defined by the straight edge of the global common color gamut, the transition boundary of the interior region, and a line extending between end points of the straight edge and the transition boundary, and the second color space area being defined by the transition boundary of the interior region and two adjacent vertices of the third plurality of vertices of the light fixture gamut; The method of claim 1 , comprising:

11. a plurality of LED-based light sources configured to generate light defined by a light fixture gamut in a color space; receiving or setting a selectable target chromaticity within a global common gamut of the color space, the global common gamut including one or more color points in the color space that are common to two or more of the plurality of LED-based light sources; determining that the selectable target chromaticity is between two adjacent vertices of a first plurality of vertices of the global common color gamut; a transition boundary defining an interior region within said global common color gamut; calculating a first oriented distance between the selectable target chromaticity and the transition boundary of the interior region and a second oriented distance between the selectable target chromaticity and a straight edge of the global common gamut between the two adjacent vertices; and modifying the selectable target chromaticity to a modified target chromaticity within the light fixture gamut based at least in part on the calculated first directional distance and the second directional distance, the modification being outward toward a boundary of the global common gamut and the light fixture gamut, the light fixture gamut including color points produced by at least one of the plurality of LED-based light sources; or generating activation signals for driving the plurality of LED-based light sources based on the selectable target chromaticity; A controller configured to: Including, the system.

12. The system of claim 11 , wherein the controller is configured to generate activation signals for driving the plurality of LED-based light sources based on the modified target chromaticity.

13. 12. The system of claim 11, wherein the light fixture color gamut at least partially encloses the global common color gamut, the light fixture color gamut being defined by colorimetric characteristics of light emitted by the multiple LED-based light sources.

14. The system of claim 11 , wherein the modified target chromaticity is outside the global common color gamut.

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