Light-emitting module

Abstract

To provide a light-emitting module that is improved in color mixture characteristics.SOLUTION: A light-emitting module comprises a substrate, and N light-emission parts (N: an integre equal to or larger than 4) which include a first light-emission part arranged most closely to the substrate and an Nth light-emission part arranged most closely to a right side of the substrate opposed to a left side, and are arranged at equal intervals on the substrate. Then, the first light-emission part and the Nth light-emission part differ in light emission color, and the inter-coordinate distance between the chromaticity coordinate of light that the first light-emission part emits and the chromaticity coordinate of light that the Nth light-emission part emits is shortest among distances between chromaticity coordinates of lights that two arbitrary light-emission parts extracted from the N light-emission parts emit.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION An embodiment of the present invention relates to a light emitting module. [Background technology]

[0002] There is a known lighting device that uses a light-emitting module with multiple colored LEDs mounted on a board as a light source, changes the lighting state of each LED, and mixes the light emitted from each LED to reproduce multiple patterns of emitted color. In such lighting devices, when producing mixed light from multiple colored LEDs, it is necessary to appropriately mix the light emitted from each LED, and if the light mixing is insufficient, color unevenness occurs in the light emitted from the lighting device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6648594 Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a light emitting module with improved color mixing characteristics. [Means for solving the problem]

[0005] A light emitting module according to an embodiment includes a substrate having a left side and a right side opposite the left side, and a plurality of light emitting unit groups each including N light emitting units (N is an integer equal to or greater than 4) that emit different light colors and are arranged at equal intervals on the substrate. Each light emitting unit group includes a first light emitting unit arranged closest to the left side of the substrate and an Nth light emitting unit arranged closest to the right side of the substrate, and the distance between the chromaticity coordinates of the light emitted by the first light emitting unit and the Nth light emitting unit is the shortest among the distances between the chromaticity coordinates of the light emitted by any two light emitting units extracted from the N light emitting units. [Effects of the Invention]

[0006] According to the embodiment, it is expected that a light emitting module with improved color mixing characteristics can be provided. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 2 is a top view of the light emitting module according to the embodiment. [Figure 2] FIG. 2 is a top view showing an arrangement of light-emitting modules according to an embodiment. [Figure 3] 10 is a table showing an example of light emitted from a light-emitting unit used in an embodiment. [Figure 4] 10 is a flowchart showing a procedure for determining the arrangement of light-emitting units (emission colors) when a light-emitting module of an embodiment has an even number of emission colors. [Figure 5] 4 is a table showing values ​​obtained by calculating the distance between chromaticity coordinates for all combinations of the light-emitting units (emission colors) shown in FIG. 3. [Figure 6] 10 is a table showing some steps of a procedure for creating pairs when the light emitting modules of one embodiment have an even number of light emitting colors. [Figure 7] 10 is a table showing a part of a procedure for determining the arrangement of other light-emitting units (light-emitting colors) when the light-emitting module of one embodiment has an even number of light-emitting colors. [Figure 8]10 is a flowchart showing a procedure for determining the arrangement of light-emitting units (light-emitting colors) when a light-emitting module of an embodiment has an odd number of light-emitting colors. [Figure 9] This is a table showing examples of specific light-emitting units (light-emitting colors) when an embodiment of the light-emitting module has an odd number of light-emitting colors, and the values ​​derived for the distance between the chromaticity coordinates for all combinations of these light-emitting units (light-emitting colors). [Figure 10] 10 is a table showing some steps in a procedure for creating pairs when a light emitting module according to an embodiment has an odd number of light emitting colors. [Figure 11] 10 is a table showing a part of a procedure for determining the arrangement of other light-emitting units (light-emitting colors) when a light-emitting module of an embodiment has an odd number of light-emitting colors. DETAILED DESCRIPTION OF THE INVENTION

[0008] The configuration of a light-emitting module 1 according to one embodiment will be described with reference to Fig. 1. Fig. 1 is a top view of the light-emitting module 1. The light-emitting module 1 includes N (types) light-emitting units 10 and a substrate 20. N is an integer of 2 or greater, and preferably an integer of 4 or greater. In Fig. 1, the light-emitting module 1 includes six (types) light-emitting units 10 (light-emitting unit 10-1 to light-emitting unit 10-6).

[0009] The light-emitting unit 10 includes a solid-state light source such as an LED element, a laser diode element, or an organic EL element. When the light-emitting unit 10 includes an LED element, the light-emitting unit 10 may be a package such as a surface mount device (SMD) or a chip scale package (CSP), or may be a bare chip. The light-emitting unit 10 is mounted on one surface of the substrate 20 using a bonding material. Examples of the bonding material include a non-conductive resin material, a conductive resin material in which a conductive filler is mixed into a resin material, and a metal material such as solder.

[0010] The substrate 20 includes a base material 21 and a pattern wiring (not shown in FIG. 1) disposed on the base material. The base material 21 is configured to be long (rectangular when viewed from above) and includes two opposing short sides (left side 22, right side 23) and two opposing long sides (top side 24, bottom side 25). The base material 21 is made of, for example, ceramic such as alumina or silicon nitride, metal such as aluminum or copper, or resin such as glass epoxy. The pattern wiring is disposed on one surface of the base material, or on both the front surface and the back surface, which is the other surface of the base material. When the substrate 20 is a multilayer substrate configured by stacking a plurality of base materials 21, the pattern wiring may be disposed between the base materials 21.

[0011] In this embodiment, among the light-emitting units 10, the light-emitting unit 10 (light-emitting unit 10a) disposed closest to the left side 22 of the substrate 20 is referred to as the first light-emitting unit 10-1, the light-emitting unit 10 disposed on the opposite side of the left side 22 of the first light-emitting unit 10-1 is referred to as the second light-emitting unit 10-2, and the light-emitting unit 10 disposed on the opposite side of the second light-emitting unit and the first light-emitting unit is referred to as the third light-emitting unit 10-3. In this manner, light-emitting units 10 up to the Nth light-emitting unit 10-N are defined. The Nth light-emitting unit 10-N is the light-emitting unit 10 disposed closest to the right side 23 of the substrate 20. Note that, since N is 6 in FIG. 1, light-emitting units 10 up to the sixth light-emitting unit 10-6 have been defined.

[0012] In this embodiment, the light-emitting units 10 are arranged at equal intervals along the longitudinal direction of the substrate 20 (base material 21). That is, the light-emitting units 10 are arranged so that the distance between adjacent light-emitting units 10 is equal. Specifically, the light-emitting units 10 are arranged so that the distance between the first light-emitting unit 10-1 and the second light-emitting unit 10-2 and the distance between the second light-emitting unit 10-2 and the third light-emitting unit 10-3 (omitted below) are equal. In other words, the light-emitting units 10 are arranged so that the distance between the (N-1)th light-emitting unit 10-(N-1) and the Nth light-emitting unit 10-N is equal regardless of the value of N. The distance between the light-emitting units 10 here may be the distance between the centers of the light-emitting units 10 or the distance between the ends of the light-emitting units 10.

[0013] Furthermore, it is preferable that the distance from the left side 22 of the substrate 20 to the light-emitting unit 10 (first light-emitting unit 10-1) disposed closest to the left side 22 of the substrate 20 is half the distance between the adjacent light-emitting units 10. In addition, it is preferable that the distance from the right side 23 of the substrate 20 to the light-emitting unit 10 (Nth light-emitting unit 10-N) disposed closest to the right side 23 of the substrate 20 is half the distance between the adjacent light-emitting units 10. Here, the distance from the left side 22 (right side 23) to the light-emitting unit 10 is, for example, the shortest distance from the center or end of the light-emitting unit 10 to the left side 22 (right side 23).

[0014] The substrate 20 is configured with pattern wiring so that the lighting of each of the light-emitting units 10 (light-emitting units 10-1 to 10-N) can be controlled individually.

[0015] When the light emitting module 1 is used in a lighting device, it is used as a light source module 2 in which a plurality of light emitting modules 1 are arranged in the longitudinal direction of a substrate 2. Figure 2 shows a top view of the light source module 2 in which a plurality of light emitting modules 1 (light emitting module 1a, light emitting module 1b) are arranged. The light emitting module 1a and the light emitting module 1b are identical. Note that "identical" here means that at least the manufacturing process and concept are identical.

[0016] In the light source module 2, the light emitting modules 1a and 1b are arranged so that the right side 23a of the substrate 20a of the light emitting module 1a and the left side 22b of the substrate 20b of the light emitting module 1b are adjacent to or in contact with each other. In this case, by configuring the light emitting modules 1a and 1b so that the distance between the light emitting unit 10 and the left side 22 (right side 23) is satisfied, the distance between the light emitting unit 10 closest to the right side 23a of the light emitting module 1a (light emitting unit 10-Na; light emitting unit 10-6a in FIG. 2) and the light emitting unit 10 closest to the left side 22b of the light emitting module 1b (light emitting unit 10-1b) becomes equal to the distance between the other light emitting units 10, and therefore the arrangement of the light emitting units 10 does not feel unnatural.

[0017] The light source module 2 may use three or more light emitting modules 1. In the light source module 2, the light emitting units 10 of the same emission color of each light emitting module 1 (in FIG. 2, light emitting module 1a and light emitting module 1b) may be controlled together or individually.

[0018] Furthermore, the light source module 2 may be configured on a single substrate. In this case, two or more groups of light-emitting units 10 corresponding to the light-emitting modules 1 are configured on the substrate.

[0019] Next, the light emitted from the light-emitting unit 10 will be described. In this embodiment, the light-emitting module 1 is arranged so that a plurality of light-emitting units 10 form groups, and the light emitted from the light-emitting units 10 constituting each group has a different emission color. Here, the light emitted from the light-emitting unit 10 may be light emitted from a solid-state light source that is the light source of the light-emitting unit 10, light emitted when the light-emitting unit 10 includes a phosphor and the phosphor is excited by light emitted from the solid-state light source, or a composite light of light emitted from the solid-state light source and light emitted from the phosphor. Here, "different emission colors" refers to different coordinates in a color coordinate system. For example, any color coordinate system, such as chromaticity coordinates on an xy chromaticity diagram, can be applied. Alternatively, "different emission colors" refers to different peak wavelengths (nm) at which the output value is high in the emission spectrum of the light emitted from the light-emitting unit 10. The peak wavelength may be a first peak wavelength, which is the wavelength at which the output of each light-emitting unit 10 is highest, or a second peak wavelength, which is the wavelength at which the output of each light-emitting unit 10 is second highest. In other words, if two light-emitting units 10 have the same first peak wavelength but different second peak wavelengths, or if one light-emitting unit 10 does not have the second peak wavelength, the two light-emitting units 10 will have different emitted colors. Note that the wavelengths compared between the light-emitting units 10 may be wavelengths from the third peak onward, or may be dominant wavelengths.

[0020] 3 shows an example of light emitted from the light-emitting units 10. In this embodiment, the light-emitting module 1 includes six light-emitting units 10 (light-emitting units 10-1 to 10-6), and each light-emitting unit 10 emits light of a different color, either red, green, blue, cyan, amber, or white (color temperature 3000K). That is, the light-emitting module 1 in FIG. 3 includes six different light-emitting units 10: a light-emitting unit 10 that emits red light (hereinafter referred to as red), a light-emitting unit 10 that emits green light (hereinafter referred to as green), a light-emitting unit 10 that emits blue light (hereinafter referred to as blue), a light-emitting unit 10 that emits cyan light (hereinafter referred to as cyan), a light-emitting unit 10 that emits amber light (hereinafter referred to as amber), and a light-emitting unit 10 that emits white light (hereinafter referred to as white). Amber and white, which include phosphors, also have a second peak wavelength, and the emission colors of the light-emitting units 10 differ in the first peak wavelength or the wavelengths after the second peak wavelength.

[0021] As described above, the light-emitting module 1 includes a plurality of light-emitting units 10 that emit light of different emission colors, and in a lighting device using this light-emitting module 1, it is preferable that color unevenness be small when light emitted from the light-emitting units 10 of two or more different emission colors is mixed. Therefore, it is important to determine at which position among the first light-emitting unit 10-1 to the Nth light-emitting unit 10-N each light-emitting unit 10 of a given emission color is to be disposed. Next, a procedure for determining the arrangement of the light-emitting units 10 (emission colors) in the light-emitting module 1 will be described.

[0022] First, a procedure E for determining the arrangement of luminous colors (hereinafter referred to as arrangement determination procedure E) when the light-emitting module 1 has an even number of luminous colors will be described. For simplicity, the following description will be given assuming that the light-emitting module 1 has one light-emitting unit 10 that emits each luminous color. That is, the description will be given assuming that the light-emitting module 1 has 2×M light-emitting units 10 and 2×M luminous colors (N=2×M, where M is an integer equal to or greater than 1, and preferably equal to or greater than 2). FIG. 4 shows a flowchart of arrangement determination procedure E. Arrangement determination procedure E includes three steps, E1 to E3.

[0023] First, in step E1, pairs are created. These pairs are combinations of light-emitting units 10 (emission colors). As mentioned above, since the light-emitting module 1 includes 2×M light-emitting units 10 (2×M types of emission colors), M pairs are created, and there are no light-emitting units 10 (emission colors) that do not form pairs.

[0024] In step E1, first, the distance between the color coordinates of each of the two light-emitting units 10 (emission colors) (hereinafter referred to as the coordinate distance) is derived when any two light-emitting units 10 (emission colors) are extracted from the light-emitting module 1. The coordinate distance is derived for all combinations of any two light-emitting units 10 (emission colors) extracted from the light-emitting module 1. In other words, the light-emitting module 1 has 2×M light-emitting units 10 (2×M types of light-emitting colors), and since there are 2×(M-1) combinations for any one light-emitting unit 10 (light-emitting color), a total of (2×M)×(2×M-1) distances between coordinates can be derived. The distances between coordinates can be derived using a formula for deriving the distance between two coordinates on an xy coordinate system commonly used in mathematics. Furthermore, the color coordinate system used to derive the distances between coordinates is one commonly used in the lighting industry, such as the xy coordinate system or the uv coordinate system. The following explanation will be given using the xy coordinate system.

[0025] A specific example of the above-mentioned procedure will be described using the chromaticity coordinates of the light-emitting units 10 (emission colors) shown in FIG. 3. In the following description of the arrangement determination procedure E, a specific example refers to an example in which the arrangement determination procedure E is applied to the light-emitting units 10 (emission colors) shown in FIG. 3. As shown in FIG. 3, each light-emitting unit 10 (emission color) has a different chromaticity coordinate. The results of deriving the inter-coordinate distance for all combinations of any two light-emitting units 10 (emission colors) shown in FIG. 3 can be summarized as shown in FIG. 5. In FIG. 5, the intersection of a row of any color and a column of any color indicates the inter-coordinate distance on the xy chromaticity coordinate for the combination of the two colors.

[0026] Next, from the inter-coordinate distances derived above, a combination that results in the shortest inter-coordinate distance for each light-emitting unit 10 (emission color) is extracted. Referring to FIG. 5 as a specific example, red has the shortest inter-coordinate distance when combined with amber (inter-coordinate distance 0.202). Green has the shortest inter-coordinate distance when combined with cyan (inter-coordinate distance 0.292). Blue has the shortest inter-coordinate distance when combined with cyan (inter-coordinate distance 0.413). Cyan has the shortest inter-coordinate distance when combined with green (inter-coordinate distance 0.292). Amber is closest when combined with white (coordinate distance 0.131). White is closest when combined with amber (coordinate distance 0.131).

[0027] Next, among the combinations with the shortest coordinate distances extracted earlier, the combination with the longest distance is determined as the first pair. Referring to a specific example, the shortest coordinate distances for each light-emitting unit 10 (emission color) are 0.202, 0.292, 0.413, 0.292, 0.131, and 0.131, and the combination with the longest coordinate distance among these is 0.413, which is the combination of blue and cyan, and this is determined as the first pair.

[0028] Next, pairs are determined from the light-emitting units 10 (light-emitting colors) not selected for the first pair, and first, combinations with a coordinate distance longer than the coordinate distance of the first pair are excluded from the pairs. Referring to a specific example, the light-emitting units 10 not selected for the first pair are red, green, amber, and white. Since the coordinate distance of the first pair is 0.413, the combination of red and green (coordinate distance 0.632) and the combination of green and amber (coordinate distance 0.431) are excluded from the pairs and will not form pairs.

[0029] In this specific example, since the only combination of green and white remaining at this point, green and white are determined to be the second pair, and the remaining red and amber are determined to be the third pair.

[0030] If it is not possible to determine all pairs simply by excluding combinations where the distance between coordinates is longer than the distance between coordinates of the first pair as described above, the second pair and subsequent pairs are determined so that the sum of the distance between coordinates of all pairs is smallest when M-1 pairs are created using all of the (2×M)-2 light-emitting units 10 ((2×M)-2 types of light-emitting colors) that were not selected for the first pair.

[0031] Referring to a specific example, the four light-emitting units 10 not selected for the first pair are red, green, amber, and white. When these are paired, two pairs are created. There are three candidates (combinations) for the two pairs. The three candidates (combinations) are shown in FIG. 6. The first candidates are a pair of red and green and a pair of amber and white, the second candidates are a pair of red and amber and a pair of green and white, and the third candidates are a pair of red and white and a pair of green and amber. Then, for each candidate, the sum of the distances between the coordinates of each pair is calculated, and the candidate with the smallest sum is adopted. In FIG. 6, the sum of the distances between the coordinates of the second candidate is the smallest, 0.577, so the second candidate pair is adopted as the second and third pairs.

[0032] When determining pairs in step E1, it is preferable that two light-emitting units 10 (emission colors) with the shortest inter-coordinate distance among all the light-emitting units 10 not form a pair. Referring to a specific example, as shown in FIG. 5, among all pairs of light-emitting units 10, the pair of white and amber (distance is 0.131) has the shortest inter-coordinate distance, so it is preferable that white and amber not form a pair. Therefore, when determining pairs from the light-emitting units 10 (emission colors) not selected as the first pair, when M-1 pairs are formed using all of the (2×M)-2 (types) light-emitting units 10 (emission colors) not selected as the first pair, the second and subsequent pairs may be determined so that the sum of the inter-coordinate distances of each pair is the second smallest, or the second and subsequent pairs may be determined so that the sum of the inter-coordinate distances of each pair is equal to or less than a specified value.

[0033] Note that, at the beginning of step E1, deriving the inter-coordinate distances in all combinations of extracting any two from the light-emitting parts 10 (light-emitting colors) included in the light-emitting module 1 is one of the methods to facilitate extracting pairs that satisfy the conditions in the subsequent procedures in step E1. If it is possible to extract pairs that satisfy the conditions using other methods in the subsequent procedures in step E1, it is not necessary to derive the inter-coordinate distances in all combinations at the beginning of step E1.

[0034] As described above, pairs are determined in step E1. Referring to specific examples, three pairs of blue and cyan, red and amber, and green and white are determined.

[0035] In the steps after step E2, for each determined pair, it is determined which position among the first light-emitting part 10-1 to the Nth light-emitting part 10-N to arrange. At this time, the light-emitting part 10 (light-emitting color) determined to be arranged at the position of the Xth light-emitting part 10-X and the paired light-emitting part 10 (light-emitting color) are determined to be arranged at the position of the (X + M)th light-emitting part 10-(X + M) (when X is a positive integer where 1 ≤ X ≤ M), or determined to be arranged at the position of the (X - M)th light-emitting part 10-(X - M) (when X is a positive integer where M < X ≤ 2×M).

[0036] In step E1, it is determined that the light-emitting units 10 (emission colors) having a relatively short distance between their chromaticity coordinates are paired, so the color mixing characteristics of the pair are good and color unevenness is small when only the two light-emitting units 10 (emission colors) that make up the pair are turned on. In other words, even if the two light-emitting units 10 (emission colors) that make up the pair are arranged at a certain distance from each other, it is unlikely that this will deteriorate the color mixing characteristics of the light-emitting module 1 (increase color unevenness), and so they can be arranged in accordance with the rules described above. Furthermore, by arranging the light-emitting units 10 (light-emitting colors) in accordance with the above-mentioned rules, when a light source module 2 is constructed in which multiple light-emitting modules 1 are arranged in the longitudinal direction of the substrate 2, the distance from any light-emitting unit 10 (light-emitting color) to the light-emitting unit 10 (light-emitting color) that forms a pair with that light-emitting unit 10 (light-emitting color) on the same light-emitting module 1 will be approximately equal to the distance from any of the above-mentioned light-emitting units 10 (light-emitting color) to the light-emitting unit 10 (light-emitting color) that has the same light-emitting color as the light-emitting unit 10 (light-emitting color) that forms the above-mentioned pair on an adjacent light-emitting module 1, and it is expected that the color mixing characteristics will be improved when multiple light-emitting modules 1 are used.

[0037] Next, in step E2, it is determined which light-emitting unit 10 (light-emitting color) is to be arranged on the outermost side among the light-emitting units 10 (light-emitting colors) mounted on the light-emitting module 1. In other words, in step E2, it is determined which light-emitting color will be the light-emitting unit 10 (first light-emitting unit 10-1) arranged closest to the left side 22 of the substrate 20 of the light-emitting module 1, and which light-emitting color will be the light-emitting unit 10 (Nth light-emitting unit 10-N, the sixth light-emitting unit 10-6 in FIG. 1) arranged closest to the right side 23 of the substrate 20 of the light-emitting module 1.

[0038] In step E2, the two light-emitting units 10 (light-emitting colors) with the shortest distance between their coordinates among all the light-emitting units 10 (light-emitting colors) included in the light-emitting module 1 are determined to be the light-emitting units 10 (light-emitting colors) to be arranged on the outermost sides of the light-emitting module 1. One of the two light-emitting units 10 (light-emitting colors) with the shortest distance between their coordinates among all the light-emitting units 10 (light-emitting colors) included in the light-emitting module 1 is determined to be arranged in the first light-emitting unit 10-1, and the other is determined to be arranged in the (2×M)th light-emitting unit 10-(2×M). Referring to the specific example, as shown in FIG. 5, the distance between the coordinates (0.131) between white and amber is the shortest, so white or amber is arranged in the first light-emitting unit 10-1 position, and the white or amber not selected as the first light-emitting unit 10-1 is arranged in the (2×M)th light-emitting unit 10-(2×M) position (sixth light-emitting unit 10-6) position. In the following description, it is assumed that white is disposed at the position of the first light-emitting unit 10-1 and amber is disposed at the position of the sixth light-emitting unit 10-6.

[0039] As described above, the light-emitting unit 10 (emission color) paired with the light-emitting unit 10 (emission color) disposed at the position of the first light-emitting unit 10-1 is disposed at the (M+1)th light-emitting unit 10-(M+1) position. Furthermore, the light-emitting unit 10 (emission color) paired with the light-emitting unit 10 (emission color) disposed at the (2×M)th light-emitting unit 10-(2×M) position is disposed at the (2×MM)th light-emitting unit 10-(2×MM)=Mth light-emitting unit 10-M position. In the specific example, since the light-emitting module 1 includes 2×3 light-emitting units 10 (M=3), the green light paired with the white light-emitting unit 10-1 is disposed at the position of the fourth light-emitting unit 10-4. Furthermore, the red light paired with the amber light-emitting unit 10-6 is disposed at the position of the third light-emitting unit 10-3.

[0040] In step E2, of the light-emitting units 10 (emission colors) mounted on the light-emitting module 1, which are the combination with the best color mixing characteristics, the two light-emitting units 10 (emission colors) with the shortest distance between chromaticity coordinates are determined to be arranged on the outermost sides of the light-emitting module 1. This is expected to improve the color mixing characteristics of the light-emitting module 1 and reduce color unevenness.

[0041] Next, in step E3, the placement of other light-emitting units 10 (light-emitting colors) whose placement has not yet been determined is determined. The other light-emitting units 10 (light-emitting colors) here are light-emitting units 10 (light-emitting colors) that have not yet been determined to be placed at the positions of the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), or the (2×M)th light-emitting unit 10-(2×M) among the light-emitting units 10 (light-emitting colors) included in the light-emitting module 1 at the end of step E2. If M is 2 or less, there are no other light-emitting units 10 (light-emitting colors) at the end of step E2, and therefore step E3 is not performed, and the placement determination procedure E ends. If M is 3 or more, step E3 is performed.

[0042] First, the case where M is 3 will be described. Since the light-emitting module 1 includes 2×M (types) of light-emitting units 10 (light-emitting colors), when M is 3, two (types) of light-emitting units 10 (light-emitting colors) remain as other light-emitting units 10 (light-emitting colors) at the end of step E2. These two (types) of light-emitting units 10 (light-emitting colors) are light-emitting units 10 (light-emitting colors) that constitute one of the pairs determined in step E1. When M is 3, the light-emitting units 10 (light-emitting colors) to be disposed at the positions of the first light-emitting unit 10-1, the third light-emitting unit 10-3, the fourth light-emitting unit 10-4, and the sixth light-emitting unit 10-6 have been determined up to step E2, so in step E3, the light-emitting units 10 (light-emitting colors) to be disposed at the positions of the second light-emitting unit 10-2 and the fifth light-emitting unit 10-5 are determined. That is, in step E3 when M is 3, the number of other light-emitting units 10 (light-emitting colors) is two, and there are also two positions for disposing the light-emitting units 10 (light-emitting colors), so there are only two candidate patterns for which light-emitting unit 10 (light-emitting color) to dispose at the position of the second light-emitting unit 10-2 (the one not to be disposed at the position of the second light-emitting unit 10-2 is automatically determined to be disposed at the position of the fifth light-emitting unit 10-5). A decision must be made as to which of these two candidate patterns to select.

[0043] At this time, in step E3, the coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the second light-emitting unit 10-2 and the adjacent light-emitting unit 10 (light color) and the coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the fifth light-emitting unit 10-5 and the adjacent light-emitting unit 10 (light color) are all derived, their sum is calculated, and the arrangement that produces the largest sum is determined as the arrangement of the other light-emitting units 10 (light color).

[0044] Referring to a specific example, the other light-emitting units 10 (light-emitting colors) are blue and cyan, and there are two patterns for arranging the other light-emitting units 10 (light-emitting colors), as shown in Figure 7, either blue or cyan is arranged at the position of the second light-emitting unit 10-2. Then, in pattern 1, the coordinate distances between the first light-emitting unit 10-1 and the third light-emitting unit 10-3, which are adjacent to the second light-emitting unit 10-2 (the coordinate distance between the first light-emitting unit 10-1 and the second light-emitting unit 10-2 and the coordinate distance between the second light-emitting unit 10-2 and the third light-emitting unit 10-3) are derived, and the coordinate distances between the fourth light-emitting unit 10-4 and the sixth light-emitting unit 10-6, which are adjacent to the fifth light-emitting unit 10-5 (the coordinate distance between the fourth light-emitting unit 10-4 and the fifth light-emitting unit 10-5 and the coordinate distance between the fifth light-emitting unit 10-5 and the sixth light-emitting unit 10-6) are derived, and the sum of these coordinate distances is derived. The same is true for pattern 2. In a specific example, the sum of the distances between coordinates in pattern 1 is 1.846, and the sum of the distances between coordinates in pattern 2 is 2.236, so pattern 2, which has the largest sum of the distances between coordinates, is determined as the arrangement of the other light-emitting units 10 (light-emitting colors).

[0045] In step E3, the arrangement having the largest inter-coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the second light-emitting unit 10-2 and the adjacent light-emitting unit 10 (light color) and the inter-coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the fifth light-emitting unit 10-5 and the adjacent light-emitting unit 10 (light color) may be determined as the arrangement of the other light-emitting unit 10 (light color).

[0046] 7, the coordinate distance (0.674) between the fourth light-emitting unit 10-4 (green) and the fifth light-emitting unit 10-5 (blue) of pattern 2 is the largest, so pattern 2 is determined as the arrangement of the other light-emitting units 10 (light-emitting colors). Also, in the specific example, as shown in FIG. 5, the coordinate distance between green and blue is the largest among all the light-emitting units 10 (light-emitting colors), so it may be determined that blue is to be arranged at the position of the fifth light-emitting unit 10-5 adjacent to the green fourth light-emitting unit 10-4. In this case, it is automatically determined that the remaining light-emitting unit 10 (light-emitting color), cyan, is to be arranged at the position of the remaining second light-emitting unit 10-2.

[0047] Next, the case where M is 4 or more will be described. Since the light-emitting module 1 includes 2×M (types) light-emitting units 10 (light-emitting colors), when M is 4 or more, at the end of step E2, four or more (types) of light-emitting units 10 (light-emitting colors) remain as other light-emitting units 10 (light-emitting colors). Note that these four or more (types) of light-emitting units 10 (light-emitting colors) each include the light-emitting units 10 (light-emitting colors) that make up the pairs determined in step E1. Then, light-emitting units 10 (light-emitting colors) to be disposed at positions other than the positions of the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), and the (2×M)th light-emitting unit 10-(2×M) are determined.

[0048] At this time, in step E3, the coordinate distances between all light-emitting units 10 (light-emitting colors) arranged at positions other than the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), and the (2×M)th light-emitting unit 10-(2×M) and adjacent light-emitting units 10 (light-emitting colors) are derived, the sum of these distances is calculated, and the arrangement that results in the largest sum is determined as the arrangement of the other light-emitting units 10 (light-emitting colors).

[0049] Specifically, the coordinate distances to be derived are the coordinate distance between the first light-emitting unit 10-1 and the second light-emitting unit 10-2, the coordinate distance between the (2×M−1)th light-emitting unit 10-(2×M−1) and the (2×M)th light-emitting unit 10-(2×M), and the coordinate distance between the Yth light-emitting unit 10-Y and the (Y+1)th light-emitting unit 10-(Y+1) (Y is a positive integer, 3≦Y<2×M−1). Regarding the coordinate distance between the Yth light-emitting unit 10-Y and the (Y+1)th light-emitting unit 10-(Y+1), Y is a positive integer, and the coordinate distance is derived for all Ys that satisfy the condition 3≦Y<2×M. Then, when all the derived coordinate distances are added up, the arrangement of the light-emitting unit 10 (emission color) that produces the largest value is determined as the arrangement of the other light-emitting units 10 (emission colors).

[0050] In addition, when Y=M, that is, the coordinate distance between the Mth light-emitting unit 10-M and the (M+1)th light-emitting unit 10-(M+1) has already been determined in step E2, so this distance does not need to be taken into consideration in step E3.

[0051] Furthermore, in step E3, the placement of the light-emitting units 10 (emission colors) may be determined in order of the longest distance between the coordinates of adjacent light-emitting units 10 (emission colors). For example, when step E2 is completed, the light-emitting units 10 (emission colors) to be placed at the positions of the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), and the (2×M)th light-emitting unit 10-(2×M) have been determined. However, if the distance between the coordinates of another light-emitting unit 10 (emission color) "orange" and the first light-emitting unit 10-1 is the longest, then "orange" is placed at the position of the second light-emitting unit 10-2 adjacent to the first light-emitting unit 10-1. Then, the light-emitting unit 10 (emission color) paired with "orange" is placed at the position of the (M+2)th light-emitting unit 10-(M+2). Next, for positions where the light-emitting unit 10 to be placed next to at least one of the positions has not been decided, the placement of the other light-emitting units 10 (light-emitting colors) is determined by similarly allocating in order the light-emitting units 10 (light-emitting colors) that have the longest inter-coordinate distance.

[0052] In step E3, the arrangement of the light-emitting units 10 (emission colors) is determined so that the distance between the chromaticity coordinates of adjacent light-emitting units 10 (emission colors) is large. This is because two light-emitting units 10 (emission colors) with a large distance between their chromaticity coordinates have poor color mixing characteristics, and arranging them with a large distance between them will result in color unevenness. Therefore, by determining the arrangement of the light-emitting units 10 (emission colors) in accordance with the procedure of step E3, it is expected that the color mixing characteristics of the light-emitting module 1 will be improved and color unevenness will be reduced.

[0053] The procedure of step E3 is performed as described above, and the placement determination procedure E is completed when the light-emitting module 1 has an even number of light-emitting colors, that is, when the light-emitting module 1 has 2×M light-emitting units 10 and 2×M light-emitting colors.

[0054] Next, a procedure O for determining the arrangement of luminous colors (hereinafter referred to as arrangement determination procedure O) when the light-emitting module 1 has an odd number of luminous colors will be described. Note that, for simplicity, the following description will be given assuming that the light-emitting module 1 has one light-emitting unit 10 that emits each luminous color. That is, the description will be given assuming that the light-emitting module 1 has (2×M+1) light-emitting units 10 and (2×M+1) luminous colors (N=2×M+1, where M is an integer equal to or greater than 1, and preferably equal to or greater than 2). FIG. 8 shows a flowchart of the arrangement determination procedure O. The arrangement determination procedure O includes four steps, O1 to O4. Note that detailed descriptions of the effects and other aspects of the same steps as step E will be omitted, but the content described in step E can be applied as is.

[0055] First, in step O1, the light-emitting unit 10 (emission color) to be placed in the center is determined. Here, the light-emitting unit 10 (emission color) to be placed in the center refers to the light-emitting unit 10 placed at the (M+1)th light-emitting unit 10-(M+1) position. In step O1, first, as in step E1, when any two light-emitting units 10 (emission colors) included in the light-emitting module 1 are extracted, the distance between the chromaticity coordinates of the two light-emitting units 10 (emission colors) (hereinafter referred to as the coordinate distance) is derived. For details, refer to the explanation in step E1, and further explanation will be omitted here.

[0056] FIG. 9 shows a specific example in which the light-emitting module 1 includes (2×M+1) light-emitting units 10 (M=3). The upper part of FIG. 9 shows the peak wavelengths and chromaticity coordinates of the seven (seven types) light-emitting units 10 (emission colors) included in the light-emitting module 1. This light-emitting module 1 differs from the light-emitting module 1 shown in FIG. 3 in that it includes a light-emitting unit 10 (hereinafter referred to as Red 2) that emits Red 2. Note that because it includes Red 2, the light-emitting unit 10 corresponding to red in the light-emitting module 1 shown in FIG. 3 is referred to as Red 1. The lower part of FIG. 9 shows the results of calculating the inter-coordinate distance for all combinations of any two light-emitting units 10 (emission colors) included in the light-emitting module 1. In the lower part of FIG. 9, the intersection of a row and a column of any color indicates the inter-coordinate distance on the xy chromaticity coordinate for the combination of the two colors. Note that in the following description of the placement determination procedure O, a specific example refers to an example in which the placement determination procedure O is applied to the light-emitting units 10 (emission colors) shown in FIG. 9.

[0057] Next, in step O1, for each light-emitting unit 10 (emission color), the sum of the coordinate distances between all other light-emitting units 10 (emission colors) is calculated, and the light-emitting unit 10 (emission color) with the largest sum is determined to be disposed at the center. Referring to a specific example, for Red 1, the calculated value is 2.405, which is the sum of 0.036, the coordinate distance between Red 2, 0.632, the coordinate distance between Green, 0.617, the coordinate distance between Blue, 0.632, the coordinate distance between Cyan, 0.202, the coordinate distance between Amber, and 0.286, the coordinate distance between White. Similarly, the calculated sum for Red 2 is 2.536, for Green, 3.071, for Blue, 3.373, for Cyan, 2.816, for Amber, 2.052, and for White, 1.923. From the above, since blue has the largest sum, it is decided in step O1 that blue will be placed at the center.

[0058] Next, in step O2, pairs are created for 2×M (types) of light-emitting elements 10 (emission colors) among the (2×M+1) (types) of light-emitting elements 10 (emission colors) included in the light-emitting module 1, excluding the light-emitting element 10 (emission color) determined to be disposed in the center in step O1. The pairs here are pairs of combinations of light-emitting elements 10 (emission colors), and M pairs are created. The light-emitting element 10 (emission color) determined to be disposed in the center in step O1 does not form a pair. The procedure is the same as step E1, so a description thereof will be omitted here. Note that the derivation of the coordinate distances for all combinations of two light-emitting elements 10 (emission colors) described in step E1 can be omitted because it is performed in the above-mentioned step O1.

[0059] Referring to a specific example (Figure 9), Red 1 is shortest when combined with Red 2 (coordinate distance 0.036). Red 2 is shortest when combined with Red 1 (coordinate distance 0.036). Green is shortest when combined with Cyan (coordinate distance 0.292). Cyan is shortest when combined with Green (coordinate distance 0.292). Amber is shortest when combined with White (coordinate distance 0.131). White is shortest when combined with Amber (coordinate distance 0.131). And since the combination with the longest coordinate distance is 0.292, the combination of Green and Cyan is determined to be the first pair.

[0060] Subsequently, in the specific example (Fig. 9), it is not determined to be disposed at the center, and the light-emitting units 10 (light-emitting colors) that are not selected for the first pair are red 1, red 2, amber, and white. When pairs are formed with these four light-emitting units 10 (light-emitting colors), only the coordinate distance of 0.315 between red 2 and white when they are paired exceeds the coordinate distance of 0.292 between the first pair. Therefore, simply excluding pairs that exceed the coordinate distance of the first pair cannot determine all pairs. Thus, Fig. 10 shows the results of deriving the coordinate distances for all combinations of pairs that satisfy the conditions. In Fig. 10, combinations including the pair of red 2 and white with a coordinate distance exceeding 0.315 are excluded, and the sum of the coordinate distances in the first candidate is minimized to 0.167. However, the first candidate is not preferable because red 1 and red 2 (coordinate distance 0.036), which are the two light-emitting units 10 (light-emitting colors) with the shortest coordinate distance among all the light-emitting units 10, form a pair. Therefore, in the specific example, the second candidate is adopted, and the combination of red 1 and white is selected for the second pair, and the combination of red 2 and amber is selected for the third pair.

[0061] Next, in the steps after step O3, for each determined pair, it is determined which position among the first light-emitting unit 10-1 to the Nth light-emitting unit 10-N (among the (2×M + 1)th light-emitting unit 10-(2×M + 1)) each is to be disposed. At this time, the light-emitting unit 10 (light-emitting color) paired with the light-emitting unit 10 determined to be disposed at the position of the Xth light-emitting unit 10-X is determined to be disposed at the position of the (X + M + 1)th light-emitting unit 10-(X + M + 1) (X is a positive integer where 1 ≦ X < M + 1), or is determined to be disposed at the position of the (X-(M + 1))th light-emitting unit 10-(X-(M + 1)) (X is a positive integer where M + 1 < X ≦ 2×M + 1). By disposing the light-emitting units 10 (light-emitting colors) in this way, in all pairs, the distance (arrangement interval) between the light-emitting units 10 (light-emitting colors) constituting the pair becomes equal. Therefore, there are no pairs with an extremely short distance (arrangement interval) between the light-emitting units 10 (light-emitting colors), and it is expected to reduce color unevenness.

[0062] In step O3, the procedure for determining the light-emitting unit 10 (light-emitting color) to be placed on the outermost side among the light-emitting units 10 (light-emitting colors) mounted on the light-emitting module 1 is the same as step E2 described above, except for the arrangement rules for the light-emitting units 10 (light-emitting colors) described above, so a detailed explanation will be omitted here.

[0063] Referring to a specific example, among all the light-emitting units 10 (light-emitting colors) included in the light-emitting module 1, the two light-emitting units 10 (light-emitting colors) with the shortest inter-coordinate distance are Red 1 and Red 2 (inter-coordinate distance 0.036). Therefore, it is decided that one of Red 1 or Red 2 will be disposed in the first light-emitting unit 10-1, and the other of Red 1 or Red 2 will be disposed in the (2×M+1)th light-emitting unit 10-(2×M+1). In the following description, it is assumed that Red 1 is disposed in the position of the first light-emitting unit 10-1, and Red 2 is disposed in the position of the seventh light-emitting unit 10-7.

[0064] As described above, the light-emitting unit 10 (emission color) paired with the light-emitting unit 10 (emission color) disposed at the position of the first light-emitting unit 10-1 is disposed at the (X+M+1)th light-emitting unit 10-(X+M+1) position, so the white paired with Red 1 is determined to be disposed at the position of the fifth light-emitting unit 10-5. Also, the light-emitting unit (emission color) paired with the light-emitting unit 10 (emission color) disposed at the seventh light-emitting unit 10-7 is disposed at the (X-(M+1))th light-emitting unit 10-(X-(M+1)), so the amber paired with Red 2 is determined to be disposed at the position of the third light-emitting unit 10-3.

[0065] Next, in step O4, the arrangement of the other light-emitting units 10 (light-emitting colors) is determined. In step O4, light-emitting units 10 (light-emitting colors) to be arranged at positions other than the positions of the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), the (M+2)th light-emitting unit 10-(M+2), and the (2×M+1)th light-emitting unit 10-(2×M+1) determined up to step O3 are determined.

[0066] First, the case where M is 3 will be described. Since the light-emitting module 1 includes (2×M+1) (types) of light-emitting units 10 (light-emitting colors), when M is 3, two (types) of light-emitting units 10 (light-emitting colors) remain as other light-emitting units 10 (light-emitting colors) at the end of step O3. These two (types) of light-emitting units 10 (light-emitting colors) are light-emitting units 10 (light-emitting colors) that constitute one of the pairs determined in step O2. When M is 3, the light-emitting units 10 (light-emitting colors) to be disposed at the positions of the first light-emitting unit 10-1, the third light-emitting unit 10-3, the fourth light-emitting unit 10-4, the fifth light-emitting unit 10-5, and the seventh light-emitting unit 10-7 have been determined up to step O3, and therefore, in step O4, the light-emitting units 10 (light-emitting colors) to be disposed at the positions of the second light-emitting unit 10-2 and the sixth light-emitting unit 10-6 are determined. That is, in step O4 when M=3, the number of other light-emitting units 10 (light-emitting colors) is two, and there are also two positions for disposing the light-emitting units 10 (light-emitting colors), so there are only two candidate patterns for which light-emitting unit 10 (light-emitting color) to dispose at the position of the second light-emitting unit 10-2 (the one not to be disposed at the position of the second light-emitting unit 10-2 is automatically determined to be disposed at the position of the sixth light-emitting unit 10-6). A decision must be made as to which of these two candidate patterns to select.

[0067] At this time, in step E3, the coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the second light-emitting unit 10-2 and the adjacent light-emitting unit 10 (light color) and the coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the sixth light-emitting unit 10-6 and the adjacent light-emitting unit 10 (light color) are all derived, their sum is calculated, and the arrangement that produces the largest sum is determined as the arrangement of the other light-emitting units 10 (light color).

[0068] Referring to a specific example, the other light-emitting units 10 (light-emitting colors) are green and cyan, and there are two patterns for arranging the other light-emitting units 10 (light-emitting colors), as shown in Figure 11, in which either green or cyan is arranged at the position of the second light-emitting unit 10-2. Then, in pattern 1, the coordinate distances between the first light-emitting unit 10-1 and the third light-emitting unit 10-3, which are adjacent to the second light-emitting unit 10-2 (the coordinate distance between the first light-emitting unit 10-1 and the second light-emitting unit 10-2 and the coordinate distance between the second light-emitting unit 10-2 and the third light-emitting unit 10-3) are derived, and the coordinate distances between the fifth light-emitting unit 10-5 and the seventh light-emitting unit 10-7, which are adjacent to the sixth light-emitting unit 10-6 (the coordinate distance between the fifth light-emitting unit 10-5 and the sixth light-emitting unit 10-6 and the coordinate distance between the sixth light-emitting unit 10-6 and the seventh light-emitting unit 10-7) are derived, and the sum of the coordinate distances is derived. The same is true for pattern 2. In a specific example, the sum of the distances between coordinates in pattern 1 is 2.071, and the sum of the distances between coordinates in pattern 2 is 2.145, so pattern 2, which has the largest sum of the distances between coordinates, is determined as the arrangement of the other light-emitting units 10 (light-emitting colors).

[0069] In step O4, the arrangement having the largest inter-coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the second light-emitting unit 10-2 and the adjacent light-emitting unit 10 (light color) and the inter-coordinate distance between the light-emitting unit 10 (light color) arranged at the position of the sixth light-emitting unit 10-6 and the adjacent light-emitting unit 10 (light color) may be determined as the arrangement of the other light-emitting unit 10 (light color).

[0070] 11, the coordinate distance (0.667) between the sixth light-emitting unit 10-6 (green) and the seventh light-emitting unit 10-7 (red 2) in pattern 2 is the largest, so pattern 2 is determined as the arrangement of the other light-emitting units 10 (light-emitting colors). Also, in the specific example, as shown in the bottom of FIG. 9, the coordinate distance between red 2 and blue is the largest among all the light-emitting units 10 (light-emitting colors), so it may be determined that green is to be placed at the position of the sixth light-emitting unit 10-6 adjacent to the seventh light-emitting unit 10-7 (red 2). In this case, it is automatically determined that the remaining light-emitting unit 10 (light-emitting color), cyan, is to be placed at the position of the remaining second light-emitting unit 10-2.

[0071] Next, a case where M is 4 or more will be described. Since the light-emitting module 1 includes (2×M+1) (types) of light-emitting units 10 (light-emitting colors), when M is 4 or more, at the end of step O3, four (types) or more of the light-emitting units 10 (light-emitting colors) remain as other light-emitting units 10 (light-emitting colors). Note that these four (types) or more of the light-emitting units 10 (light-emitting colors) each include the light-emitting units 10 (light-emitting colors) that make up the pairs determined in step O2.

[0072] At this time, in step O4, the coordinate distances between all light-emitting units 10 (light-emitting colors) arranged at positions other than the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), the (M+2)th light-emitting unit 10-(M+2), and the (2×M+1)th light-emitting unit 10-(2×M+1) are derived and the sum of these distances is calculated, and the arrangement that results in the largest sum is determined as the arrangement of the other light-emitting units 10 (light-emitting colors).

[0073] Specifically, the coordinate distances to be derived are the coordinate distance between the first light-emitting unit 10-1 and the second light-emitting unit 10-2, the coordinate distance between the (2×M)th light-emitting unit 10-(2×M) and the (2×M+1)th light-emitting unit 10-(2×M+1), and the coordinate distance between the Yth light-emitting unit 10-Y and the (Y+1)th light-emitting unit 10-(Y+1) (Y is a positive integer, 3≦Y<2×M). Regarding the coordinate distance between the Yth light-emitting unit 10-Y and the (Y+1)th light-emitting unit 10-(Y+1), Y is a positive integer, and the coordinate distance is derived for all Ys that satisfy the condition 3≦Y<2×M. Then, when all the derived coordinate distances are added up, the arrangement of the light-emitting units 10 (emission colors) that produces the largest value is determined as the arrangement of the other light-emitting units 10 (emission colors).

[0074] In addition, when Y=M, that is, the coordinate distance between the Mth light-emitting unit 10-M and the (M+1)th light-emitting unit 10-(M+1), and when Y=M+1, that is, the coordinate distance between the (M+1)th light-emitting unit 10-(M+1) and the (M+2)th light-emitting unit 10-(M+2), have already been determined in step O3, so this distance does not need to be taken into consideration in step O4.

[0075] Furthermore, in step O4, the placement may be determined in order from the light-emitting unit 10 (light-emitting color) with the longest distance between the coordinates of adjacent light-emitting units 10 (light-emitting colors). For example, at the end of step O3, the light-emitting units 10 (light-emitting colors) to be placed at the positions of the first light-emitting unit 10-1, the Mth light-emitting unit 10-M, the (M+1)th light-emitting unit 10-(M+1), the (M+2)th light-emitting unit 10-(M+2), and the (2×M+1)th light-emitting unit 10-(2×M+1) have been determined, but if the distance between the coordinates of another light-emitting unit 10 (light-emitting color) "orange" and the first light-emitting unit 10-1 is the longest, then "orange" is placed at the position of the second light-emitting unit 10-2 adjacent to the first light-emitting unit 10-1. Then, the light-emitting unit 10 (light-emitting color) paired with "orange" is placed at the (M+3)th light-emitting unit 10-(M+3) position. Next, for positions where at least one adjacent light-emitting unit 10 has not been decided, the light-emitting unit 10 (light-emitting color) with the longest inter-coordinate distance is similarly assigned in order, thereby determining the placement of the other light-emitting units 10 (light-emitting colors).

[0076] The procedure of step O4 is performed as described above, and the placement determination procedure O is completed when the light-emitting module 1 has an odd number of light-emitting colors, that is, when the light-emitting module 1 has 2×M+1 light-emitting units 10 and 2×M+1 light-emitting colors.

[0077] The above describes the procedures for determining the arrangement of the light-emitting units 10 (emission colors) in the light-emitting module 1, but in the arrangement determination procedures E and O, the step of determining the outermost arrangement may be performed before creating pairs. Also, in the arrangement determination procedure O, the step of determining the outermost arrangement may be performed before the step (O1) of determining the central arrangement.

[0078] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0079] 1 Light-emitting module 10 Light-emitting part 10-1 First light-emitting part 10-2 Second light-emitting part 10-4 Third light-emitting part 10-4 Fourth light-emitting part 10-5 Fifth light-emitting part 10-6 Sixth light-emitting part 20 Substrate 22 Left side 23 Right hand side

Claims

1. a substrate having a left side and a right side opposite the left side; a light-emitting module having a plurality of light-emitting unit groups, each of which has a different light-emitting color and is arranged at equal intervals on the substrate, each of which is made up of N light-emitting units (N is an integer of 4 or more); In one of the light-emitting unit groups, the light-emitting module has a first light-emitting unit arranged closest to the left side of the substrate and an Nth light-emitting unit arranged closest to the right side of the substrate, and the coordinate distance between the chromaticity coordinate of the light emitted by the first light-emitting unit and the chromaticity coordinate of the light emitted by the Nth light-emitting unit is the shortest among the distances between the chromaticity coordinates of the light emitted by any two light-emitting units extracted from the N light-emitting units.

2. a substrate having a left side and a right side opposite the left side; a light-emitting module having a plurality of light-emitting unit groups, each of which has a different light-emitting color and is arranged at equal intervals on the substrate, each of which is made up of N light-emitting units (N is an integer of 4 or more); Each of the light-emitting unit groups includes a first light-emitting unit arranged closest to the left side of the substrate and an Nth light-emitting unit arranged closest to the right side of the substrate, and the coordinate distance between the chromaticity coordinate of the light emitted by the first light-emitting unit and the chromaticity coordinate of the light emitted by the Nth light-emitting unit is the shortest among the distances between the chromaticity coordinates of the light emitted by any two light-emitting units extracted from the N light-emitting units.

3. 3. The light-emitting module according to claim 1 or 2, wherein, in the light-emitting unit group, N is an even number equal to or greater than 4 (M is an integer equal to or greater than 2, and N=2×M), and the names of the light-emitting units are defined from the second light-emitting unit to the (N-1)th light-emitting unit in ascending order of proximity to the first light-emitting unit, and when a combination is derived for the N light-emitting units such that the distance between the chromaticity coordinates of the light emitted by each of the N light-emitting units is shortest in relation to all of the (N-1) light-emitting units different from itself, one of the two light-emitting units constituting the combination with the longest distance between the shortest chromaticity coordinates derived for each of the N light-emitting units is disposed as the Xth light-emitting unit, and the other is disposed as the X+Mth light-emitting unit (X is an integer satisfying 1≦X≦M).

4. The light-emitting module described in claim 1 or 2, characterized in that in the light-emitting unit group, N is an odd number greater than or equal to 5 (M is an integer greater than or equal to 2, and N=2×M+1), and the names of the light-emitting units are defined from the second light-emitting unit to the N-1th light-emitting unit in ascending order of their placement positions from the first light-emitting unit, and when the sum of the distances between the chromaticity coordinates of the light emitted by each of the N light-emitting units in relation to all N-1 light-emitting units different from itself is derived, the light-emitting unit with the largest sum is placed as the M+1th light-emitting unit.

5. the light-emitting module according to claim 4, characterized in that, in the light-emitting unit group, N is an odd number equal to or greater than 5 (M is an integer equal to or greater than 2, and N=2×M+1), and the names of the light-emitting units are defined from the second light-emitting unit to the (N-1)th light-emitting unit in ascending order of proximity to the first light-emitting unit, when a combination is derived in which the distance between the chromaticity coordinates of light emitted by each of the N light-emitting units is shortest in relation to all of the N-1 light-emitting units different from itself, one of the two light-emitting units constituting the combination with the longest distance between the shortest chromaticity coordinates derived for each of the N light-emitting units is disposed as the Xth light-emitting unit, and the other is disposed as the (X+M+1)th light-emitting unit (X is an integer satisfying 1≦X≦M).

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