JP2007258202A - Illumination light source - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an illumination light source that has high luminous flux, improves an average color rendering index, and can control a luminescent color. <P>SOLUTION: The illumination light source having a plurality of types of light-emitting diodes having different luminescent colors has at least two blue-based light-emitting diodes having different peak light-emitting wavelengths in the plurality of types of light-emitting diodes having different luminescent colors. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an illumination light source including a light emitting diode that can emit white light and has excellent color rendering as a light source for illumination.

  Conventionally, for example, in supermarkets and clothing stores, in order to stimulate the appearance of products and the willingness to purchase, the products are illuminated and promoted by consumers with the so-called “object color” reflected by the products. Things have been done.

  In such illumination, “color rendering” is used as a standard for evaluating lighting. However, evaluation is performed using “average color rendering index Ra” as a standard for evaluating this color rendering. is doing.

In this case, illumination with a large average color rendering index Ra is a high-quality light source, and even in JIS, the average color rendering index Ra has a value of 90 or more and is said to be a high color rendering light source.
Incidentally, in recent years, light-emitting diodes (hereinafter also referred to as “LEDs”), which are small-sized semiconductor elements with high luminous efficiency and capable of emitting bright colors, have been used as light-emitting elements. Three primary color light emitting diodes (LEDs) can emit white light by mixing these colors. As a result, the light emitting diode is widely used as a backlight light source for a liquid crystal display, for example.

  However, when used as a light-emitting element in this way, it is sufficient to make white light in consideration of the light emission color of the light-emitting element itself, but when using the so-called “object color” as described above, , Color rendering must be considered.

  For this reason, in Patent Document 1 (Japanese Patent Laid-Open No. 10-209504), when light-emitting diodes are used as illumination light sources by simulation, three different-colored light-emitting diodes (LEDs) are used, and the wavelength of each LED is changed. It is shown that the average color rendering index Ra can be 80 or more by setting 455 to 490 nm, 530 to 570 nm, and 605 to 630 nm.

  Further, in Patent Document 2 (Japanese Patent Laid-Open No. 11-177143), a desired correlated color temperature can be obtained only by mixing three colors of a red light emitting diode, a green light emitting diode, and a blue light emitting diode based on actual measurement values. It is shown that the average color rendering index of the thing is low.

  In addition to the red, green, and blue light emitting diodes, the average color rendering index Ra is 88 or more by using three types of light emitting diodes, that is, six types of light emitting diodes, in addition to the red, green, and blue light emitting diodes. An illumination light source is disclosed.

  However, in the illumination light source of Patent Document 1, the wavelength of each LED is calculated by simulation when the light emitting diode is used as the illumination light source. This simulation assumes that the emission spectrum of the light source is a Gaussian distribution type. Therefore, a large error occurs with the actual spectral distribution, and in actuality, the average color rendering index Ra cannot be 80 or more.

The illumination light source disclosed in Patent Document 2 uses six types of light-emitting diodes, and the light-emitting diodes are made of different materials for each wavelength as the light-emitting layer, and each has light-emitting characteristics. , Life and temperature characteristics are different.

  Therefore, when using various types of light emitting diodes with different peak wavelengths, it is difficult to control to emit white light in consideration of these characteristics, and reliability (lifetime) is reduced. Considering the present situation, it is impossible to obtain an illumination light source having an average color rendering index Ra of 88 or more.

  For this reason, Patent Document 3 (Japanese Patent Application Laid-Open No. 2003-45206) proposes an illumination light source using four types of light emitting diodes: a blue light emitting diode, a blue green light emitting diode, an orange light emitting diode, and a red light emitting diode. ing.

As a result, it is possible to provide an LED illumination light source that is highly efficient, has high color rendering properties with an average color rendering index Ra of 90 or more, and can easily control the emission color with LEDs having the minimum number of colors of four types. It is shown.
Japanese Patent Laid-Open No. 10-209504 JP-A-11-177143 JP 2003-45206 A

  By the way, in Patent Document 3, a blue light emitting diode having an emission peak at 450 to 470 nm, a blue-green light emitting diode having an emission peak at 510 to 540 nm, an orange light emitting diode having an emission peak at 580 to 600 nm, and 625 to 650 nm. It is disclosed that by using four types of light emitting diodes of red light emitting diodes having a light emission peak, high color rendering properties with an average color rendering index Ra of 90 or more are exhibited with high efficiency.

  However, in Patent Document 3, the above four types of light-emitting diodes are used by a simulation based on an actual measurement value, and the wavelength of the actual measurement value performed by the inventors of the present application, According to a simulation that is closer to reality by a combination with the wavelength obtained by shifting the actual measurement value, the actual color rendering evaluation number Ra does not become 90 or more.

An object of the present invention is to provide an illumination light source that has a high luminous flux, has an improved average color rendering index, and can easily control the emission color.
In addition, the present invention provides an illumination light source in which variations in chromaticity and luminous flux of LED elements are leveled in units of light emitting element mounting packages, and variations in chromaticity and luminous flux can be reduced between the light emitting element mounting packages. One of the purposes.

  Another object of the present invention is to provide an illumination light source that has a high luminous flux, has an average color rendering index Ra of 90 or more, and can easily control the emission color.

In order to solve the above problems, the present inventors have found the illumination light source of the present invention.
That is, the present invention includes the following aspects (1) to (8), for example.
(1) An illumination light source comprising two or more blue light emitting diodes having different peak emission wavelengths among a plurality of types of light emitting diodes having different emission colors.
(2) An illumination light source including a plurality of types of light emitting diodes having different emission colors,
A red light emitting diode,
A green light emitting diode,
Two or more blue light emitting diodes having different peak emission wavelengths;
The illumination light source according to (1) above, comprising:
(3) The two or more blue light emitting diodes having different peak emission wavelengths are two or more blue light emitting diodes having different peak emission wavelengths having a peak emission wavelength in a range of 380 to 480 nm. The illumination light source according to any one of (1) and (2).
(4) The blue light-emitting diode has a first blue light-emitting diode having a peak light emission wavelength of greater than 450 nm and not more than 480 nm, and a second blue light-emitting diode having a peak light emission wavelength of 380 nm to 450 nm. The illumination light source according to (3), characterized in that
(5) The red light emitting diode is a red light emitting diode having a peak emission wavelength in a range of 600 to 640 nm,
The illumination light source according to any one of (1) to (4), wherein the green light emitting diode is a green light emitting diode having a peak emission wavelength in a range of 500 to 540 nm.
(6) The illumination light source according to any one of (1) to (5), further including a yellow-green light emitting diode.
(7) The illumination light source according to (6), wherein the yellow-green light-emitting diode is a yellow-green light-emitting diode having a peak emission wavelength in a range of 550 nm to 590 nm.
(8) The illumination light source according to any one of (6) and (7), wherein the illumination light source has an average color rendering index Ra of 90 or more.

  According to the illumination light source of the present invention, that is, the illumination light source including the light emitting diodes having different types of emission colors, the illumination light source including the light emitting diodes having different types of emission colors, Since different light emitting diodes have two or more blue light emitting diodes having different peak emission wavelengths, the number of blue light emitting diodes having a low luminous flux can be increased to two or more to improve the luminous flux and emit light. Color control becomes easy.

  In addition, since the green light emitting diode and the two or more blue light emitting diodes can be composed of the same light emitting layer (material) such as InGaN, for example, it can be manufactured at low cost.

  Further, according to an illumination light source that is one embodiment of the present invention, that is, an illumination light source including a red light emitting diode, a green light emitting diode, and two or more blue light emitting diodes having different peak emission wavelengths, By setting the number of low blue light emitting diodes to two or more, the luminous flux can be improved and white light can be emitted by color mixture, the average color rendering index is improved, and the emission color can be easily controlled. .

  In addition, by using at least four types of light emitting diodes in this way, the luminous flux can be increased compared to the case of using three types of light emitting diodes, and the variation of the luminous flux is leveled in units of light emitting element mounting packages. In addition, it is possible to provide an illumination light source that can reduce variations in chromaticity and luminous flux between light emitting element mounting packages.

  An illumination light source according to an embodiment of the present invention, that is, two or more blue light emitting diodes having different peak emission wavelengths have a peak emission wavelength in the range of 380 to 480 nm, and two or more blue colors having different peak emission wavelengths According to the illumination light source which is a light emitting diode, if the peak emission wavelength of two or more blue light emitting diodes is in such a range, the luminous flux can be improved, the average color rendering index can be improved, and the emission color can be controlled. Becomes easy.

An illumination light source according to an embodiment of the present invention, that is, a blue light emitting diode, has a first blue light emitting diode having a peak light emission wavelength of greater than 450 nm and not more than 480 nm, and a peak light emission wavelength of 380 nm to 450 nm. According to the illumination light source composed of one or more second blue light emitting diodes having two blue light emitting diodes, the luminous efficiency can be improved, the average color rendering index can be improved, and the emission color can be controlled. It becomes easy.

  An illumination light source according to an embodiment of the present invention, that is, a red light emitting diode is a red light emitting diode having a peak light emitting wavelength in a range of 600 to 640 nm, and a green light emitting diode has a peak light emitting wavelength in a range of 500 to 540 nm. According to the illumination light source which is a green light emitting diode having a peak emission wavelength in such a range, white light can be emitted by color mixture, the average color rendering index can be improved, and the emission color can be easily controlled. Become.

  According to the illumination light source that is an embodiment of the present invention, that is, the illumination light source including the yellow-green light-emitting diode, by adding the yellow-green light-emitting diode, in the chromaticity diagram, as shown in FIG. The color gamut area connecting the light-emitting diodes becomes larger, closer to white light, and high color rendering properties with an average color rendering index Ra of 90 or more are exhibited.

  In addition, the green light emitting diode and the two or more blue light emitting diodes are composed of the same light emitting layer (material) such as InGaN, and the red light emitting diode and the yellow green light emitting diode are the same such as AlInGaP. Since it can comprise a light emitting layer (substance), it can be manufactured at low cost.

  In addition, by using five or more types of light emitting diodes in this way, the light flux can be increased, and the variation in the light flux is leveled in units of light emitting element mounting packages, and the chromaticity, An illumination light source that can reduce variations in luminous flux can be provided.

Hereinafter, embodiments (examples) of the present invention will be described in more detail with reference to the drawings.
FIG. 1 is a schematic plan view showing a first embodiment of the illumination light source of the present invention, and FIG. 2 is a schematic sectional view taken along line XX of the illumination light source of FIG.

In FIG. 1, the code | symbol 10 has shown the illumination light source of this invention by the whole.
As shown in FIG. 1, the illumination light source 10 of the present invention includes a light emitting element mounting package 12. The light emitting element mounting package 12 is bonded to a substantially rectangular flat plate-like substrate 14 and an outer peripheral upper surface of the substrate 14. The reflector frame body 16 is provided.

  The substrate 14 and the reflector frame 16 form a light emitting element housing recess 18 for housing the light emitting diode 20 as a light emitting element at the center thereof.

  That is, the reflector frame 16 has an opening 22 for accommodating the light emitting diode 20 at the center thereof, and the light emitting element accommodating recess 18 is formed from the substrate 14 and the reflector frame 16 by the opening 22. Is to be formed.

Here, the reflector frame 16 has a tapered inner wall surface in which the opening diameter of the surface (lower surface) facing the substrate is smaller than the opening diameter of the opposite surface (upper surface).
In this case, the shape of the opening 22 is not determined, and can be appropriately changed to, for example, a substantially circular shape or a substantially square shape. However, if the opening portion 22 is substantially circular, the light emitting diode 20 accommodated in the opening portion 22 can be changed. The light to be emitted can be reflected upward by the light reflecting surface 22A, which is the tapered inner wall surface of the substantially circular opening 22, and can be uniformly emitted to the outside.

The substrate 14 functions as a support for supporting the light emitting element, and functions as a wiring substrate by arranging a wiring pattern (not shown).
In the illumination light source 10 of this embodiment, as shown in FIG. 2, the four types of light emitting diodes 20 are spaced apart from each other at a central angle of 90 ° on the same circumference in the light emitting element housing recess 18. It is stored.

  That is, these light emitting diodes 20 are composed of a red light emitting diode 20A, a green light emitting diode 20B, and two blue light emitting diodes 20C and 20D having different peak light emitting wavelengths.

  In this case, the blue light emitting diodes 20C and 20D are desirably two blue light emitting diodes having peak emission wavelengths in the range of 380 to 480 nm and different peak emission wavelengths.

  In the case of this embodiment, the two blue light emitting diodes 20C and 20D are a blue light emitting diode 20C which is a first blue light emitting diode (hereinafter referred to as a “blue light emitting diode”) and a second blue light emitting diode. The light emitting diode is composed of a violet light emitting diode 20D (hereinafter referred to as “violet light emitting diode”).

  That is, since the light emitting diode 20 includes the red light emitting diode 20A, the green light emitting diode 20B, and the two blue light emitting diodes 20C and 20D having different peak light emitting wavelengths, the blue light emitting diode having a low luminous flux is provided. By setting the number of the light emitting diodes 20C and the violet light emitting diode 20D to two, the luminous flux can be improved.

  In addition, as shown in FIG. 3, in the chromaticity diagram, the color gamut area (ABDC) connecting these light emitting diodes 20A, 20B, 20C, and 20D is a red light emitting diode and a green light emitting diode as in the prior art. And the color gamut area (ABC) in the case where the blue light emitting diode is composed of the three primary colors RGB, and is excellent in color reproducibility.

  In this case, the red light emitting diode 20A is a red light emitting diode having a peak light emitting wavelength in the range of 600 to 640 nm, the green light emitting diode 20B is a green light emitting diode having a peak light emitting wavelength in the range of 500 to 540 nm, The blue light emitting diode 20C is desirably a blue light emitting diode having a peak emission wavelength in the range of greater than 450 nm and less than or equal to 480 nm.

  As a result of performing a simulation by shifting the wavelength of the blue light-emitting diode by 5 nm based on the measured value of the blue light-emitting diode, as shown by the one-point difference line of the spectral distribution in FIG. It is desirable that the light emitting diode is composed of a violet light emitting diode having a peak emission wavelength in the range of 380 nm to 450 nm.

  As described above, the red light emitting diode 20A, the green light emitting diode 20B, and the two blue light emitting diodes 20C and 20D having different peak light emission wavelengths, that is, the blue light emitting diode 20C and the violet light emitting diode 20D, By selecting the peak emission wavelength from the above range, the average color rendering index Ra is improved (see Example 1 and Comparative Example 1 described later).

Further, since the green light emitting diode 20B and the two blue light emitting diodes 20C and 20D can be formed of the same light emitting layer (material) such as InGaN, for example, it can be manufactured at low cost. .

  In addition, by using the four types of light emitting diodes in this way, the light flux can be increased, and the variation in the light flux is leveled in units of the light emitting element mounting packages, and the chromaticity, the light flux between the light emitting element mounting packages. The illumination light source which can reduce the dispersion | variation of can be provided.

  The red light emitting diode 20A is not particularly limited, and for example, a GaAsP-based, AlInGaP-based, GaAlAs-based light-emitting diode can be used.

  Further, the green light emitting diode 20B, the blue light emitting diode 20C, and the violet light emitting diode 20D are not particularly limited. For example, a light emitting diode such as a GaN system such as AlInGaN, InGaN, or AlGaN, a ZnO system, or a ZnSe system is used. can do.

  The light emitting element mounting package 12 of the present invention configured as described above is used on a light emitting element connecting wiring pattern layer (not shown) in the light emitting element housing recess 18 from the substrate 14 and the reflector frame 16 in use. For example, the light emitting diodes 20 are mounted so as to be electrically connected via bump electrodes. And the illumination light source 10 is comprised by resin-sealing with transparent resin, such as an epoxy resin and a silicone resin, in the recessed part 18 for light emitting element accommodation in which the light emitting diode 20 was accommodated.

  In this embodiment, as shown in FIGS. 1 and 2, the illumination light source 10 is configured by one light emitting element mounting package 12, but a plurality of light emitting element mounting packages 12 are provided on a common substrate 14. The illumination light source 10 can also be configured by arranging the reflector frame 16 in which a plurality of openings 22 are formed in an appropriate arrangement shape. That is, for example, one illumination light source 10 can be configured as a whole by arranging in a matrix as shown in FIG. 5 and concentric circles as shown in FIG.

  In this embodiment, as shown in FIGS. 1 and 2, one red light emitting diode 20A, a green light emitting diode 20B, a blue light emitting diode 20C, and a violet color are provided in one light emitting element mounting package 12, respectively. Although the light emitting diode 20D is configured, a plurality of these are combined. For example, as shown in FIG. 7, two red light emitting diodes 20A and two green light emitting diodes 20B are provided in one light emitting element mounting package 12, respectively. The blue light emitting diode 20C and the violet light emitting diode 20D may be used.

  Further, although not shown, when the red light emitting diode 20A, the green light emitting diode 20B, the blue light emitting diode 20C, and the violet light emitting diode 20D are arranged in one light emitting element mounting package 12, the number of these light emitting diodes is set. They may be arranged differently.

  For example, when the light emitting layer (material) of the light emitting diode 20A is AlInGaP, there is a concern that the reliability of the red light emitting diode 20A and the light emitting element mounting package 12 may be deteriorated because the light flux is greatly deteriorated at a high temperature.

For this reason, in the case of the light emitting element mounting package 12 used at a high temperature, for example, by disposing the two red light emitting diodes 20A, it is possible to suppress the current value flowing through one red light emitting diode 20A. . Thereby, the reliability of the red light emitting diode 20A and the light emitting element mounting package 12 can be increased.

  Further, in order to reduce the cost of light emitting diodes or to reduce the burden of light emitting diodes having a high luminous flux ratio, for example, two red light emitting diodes 20A, four green light emitting diodes 20B, and blue light emitting diodes 20C are provided. It is also possible to arrange two different violet light emitting diodes 20D in different numbers, such as two.

  Further, the spectral waveforms of the two blue light emitting diodes 20C and 20D can be configured such that two wavelength peaks are remarkably separated as shown in FIG. 8, or as shown in FIG. Two wavelength peaks may be overlapped.

In this embodiment, the red light emitting diode 20A, the green light emitting diode 20B, and two blue light emitting diodes 20C and 20D having different peak light emitting wavelengths, that is, the blue light emitting diode 20C and the violet light emitting diode 20D are used. Three or more blue light emitting diodes, for example, as shown in the spectral distribution diagram of FIG. 21, a blue light emitting diode 20C, a first violet light emitting diode 20D1, and a second violet light emitting diode 20
It is good also as D2.

  Also in this case, the blue light emitting diodes are desirably two or more blue light emitting diodes having a peak light emission wavelength in the range of 380 to 480 nm and having different peak light emission wavelengths.

FIG. 10 is a schematic plan view showing a second embodiment of the illumination light source of the present invention, and FIG. 11 is a schematic sectional view taken along line XX of the illumination light source of FIG.
The light-emitting element mounting substrate 1 shown in FIG. 10 has basically the same configuration as that of the illumination light source 10 of the first embodiment shown in FIGS. The detailed description is omitted.

  1 and 2, the red light emitting diode 20A, the green light emitting diode 20B, two blue light emitting diodes 20C and 20D having different peak light emitting wavelengths, that is, the blue light emitting diode 20C, and a violet color. Although comprised from the light emitting diode 20D, the illumination light source of this embodiment is further provided with the yellow-green light emitting diode 20E.

  That is, in the illumination light source 10 of this embodiment, as shown in FIG. 10, five types of light emitting diodes 20, that is, a red light emitting diode 20 </ b> A, a green light emitting diode 20 </ b> B, and a peak light emission are provided in the light emitting element housing recess 18. Two blue light emitting diodes 20C and 20D having different wavelengths, that is, the blue light emitting diode 20C and the violet light emitting diode 20D are housed concentrically so as to be spaced apart from each other at a central angle of 90 °, and further emit yellowish green light The diode 20E is housed in these central positions.

  According to the illumination light source of this embodiment, since the yellow green light emitting diode 20E is provided, by adding the yellow green light emitting diode 20E, as shown in FIG. 12, in the chromaticity diagram, these light emitting diodes 20A and 20B. , 20C, 20D, 20E, the color gamut area (ABC) in the case where the three primary colors of RGB of the red light emitting diode, the green light emitting diode, and the blue light emitting diode are configured as in the past. The color reproducibility increases, the color reproducibility is excellent, and the high color rendering properties with an average color rendering index Ra of 90 or more are exhibited.

In this case, the red light emitting diode 20A is a red light emitting diode having a peak light emission wavelength in the range of 600 to 640 nm, and the green light emitting diode 20B is 500 to 54.
It is desirable that the green light emitting diode having a peak emission wavelength in the range of 0 nm, and the blue light emitting diode 20C be a blue light emitting diode having a peak emission wavelength in the range of 450 nm to 480 nm or less.

Further, it is desirable that the yellow-green light emitting diode 20E is a yellow-green light emitting diode having a peak emission wavelength in the range of 550 nm to 590 nm.
As a result of performing a simulation by shifting the wavelength of the blue light-emitting diode by 5 nm based on the measured value of the blue light-emitting diode, as shown by the one-point difference line of the spectral distribution in FIG. It is desirable that the light emitting diode is composed of a violet light emitting diode having a peak emission wavelength in the range of 380 nm to 440 nm.

  That is, as described above, the red light emitting diode 20A, the green light emitting diode 20B, the two blue light emitting diodes 20C and 20D having different peak light emission wavelengths, that is, the blue light emitting diode 20C, the violet light emitting diode 20D, and the yellow light emitting diode 20D. By configuring the green light emitting diode 20E and selecting these peak emission wavelengths from the above ranges, the average color rendering index Ra is improved (see Example 3 and Comparative Example 2 described later).

  Further, the green light emitting diode 20B and the two blue light emitting diodes 20C and 20D are composed of the same light emitting layer (material) such as InGaN, and the red light emitting diode 20A and the yellow green light emitting diode 20E are Since it can be composed of the same light emitting layer (material) such as AlInGaP, it can be manufactured at low cost.

  The yellow-green light emitting diode 20E is not limited to the AlInGaP system, and for example, a light emitting diode such as a GaAsP system or a GaAlAs system can also be used.

  In addition, by using the five types of light emitting diodes in this way, the light flux can be increased, and the variation in the light flux is leveled in units of light emitting element mounting packages, and the chromaticity, light flux between the light emitting element mounting packages. The illumination light source which can reduce the dispersion | variation of can be provided.

  In this embodiment, as shown in FIGS. 10 and 11, the illumination light source 10 is configured by one light emitting element mounting package 12. However, similarly to FIGS. 5 and 6, the illumination light source 10 is formed on the common substrate 14. The illumination light source 10 can also be configured by arranging the plurality of light emitting element mounting packages 12 in an appropriate arrangement shape and arranging the reflector frame 16 in which the plurality of openings 22 are formed. That is, for example, one illumination light source 10 can be configured as a whole by arranging in a matrix shape, a concentric circle shape, or the like.

  In this embodiment, as shown in FIGS. 10 and 11, one light emitting element mounting package 12 includes one red light emitting diode 20A, green light emitting diode 20B, blue light emitting diode 20C, and violet. Although composed of the light emitting diode 20D and the yellow-green light emitting diode 20E, similarly to FIG. 7, a plurality of these are combined to form one light emitting element mounting package 12 with two red light emitting diodes 20A and green light emitting elements. A diode 20B, a blue light emitting diode 20C, a violet light emitting diode 20D, and a yellow-green light emitting diode 20E may be used.

Further, although not shown, when the red light emitting diode 20A, the green light emitting diode 20B, the blue light emitting diode 20C, the violet light emitting diode 20D, and the yellow green light emitting diode 20E are disposed in one light emitting element mounting package 12, The number of the light emitting diodes may be different.

  For example, when the light emitting layer (material) of the light emitting diode 20A is AlInGaP, there is a concern that the reliability of the red light emitting diode 20A and the light emitting element mounting package 12 may be deteriorated because the light flux is greatly deteriorated at a high temperature.

  For this reason, in the case of the light emitting element mounting package 12 used at a high temperature, for example, by disposing the two red light emitting diodes 20A, it is possible to suppress the current value flowing through one red light emitting diode 20A. . Thereby, the reliability of the red light emitting diode 20A and the light emitting element mounting package 12 can be increased.

  Further, in order to reduce the cost of light emitting diodes or to reduce the burden of light emitting diodes having a high luminous flux ratio, for example, two red light emitting diodes 20A, four green light emitting diodes 20B, and blue light emitting diodes 20C are provided. It is also possible to arrange them in different numbers, such as two, two violet light emitting diodes 20D, and three yellow-green light emitting diodes 20E.

  Further, the spectral waveforms of the two blue light emitting diodes 20C and 20D can be configured such that two wavelength peaks are remarkably separated as shown in FIG. 13, or as shown in FIG. Two wavelength peaks may be overlapped.

In this embodiment, the red light emitting diode 20A, the green light emitting diode 20B, and two blue light emitting diodes 20C and 20D having different peak light emitting wavelengths, that is, the blue light emitting diode 20C, the violet light emitting diode 20D, and the yellowish green color. The light emitting diode 20E includes three or more blue light emitting diodes, for example, as shown in the spectral distribution diagram of FIG. 21, the blue light emitting diode 20C, the first violet light emitting diode 20D1, and the second violet light emitting. The diode 20D2 may be used.

(Example 1) (red + green + blue + first violet color)
LED package comprising a red light emitting diode made of AlInGaP, a green light emitting diode made of InGaN, and a blue light emitting diode made of InGaN ("UVGB1306L
", Stanley Electric Co., Ltd.) was prepared.

  Then, the red light emitting diode, the green light emitting diode, and the blue light emitting diode are individually turned on, and each light emitting diode for each 5 nm is measured using a measuring device ("OL770 Multi-channel Spectroradiometer", manufactured by Optronic Laboratories, Inc.). Wavelength-relative spectral data was obtained.

  That is, the wavelength-relative spectrum data of each of these light emitting diodes is as shown in FIG. 15 for the red light emitting diode, the peak wavelength is 565 nm, and for the green light emitting diode, as shown in FIG. The peak wavelength was 520 nm. In the blue light emitting diode, the peak wavelength was 465 nm as shown in FIG.

Then, by shifting the wavelength-relative spectrum data of the blue light emitting diode, the wavelength-relative spectrum data of the first violet light emitting diode having a peak wavelength of 440 nm was obtained as shown in FIG.

Then, by using the wavelength-relative spectrum data of each of these light emitting diodes and using the data every 5 nm, the chromaticity coordinates x = y = 0.3333 (correlated color temperature 5
The luminous flux ratio was calculated to be 453 K). As shown in Table 1, red light emitting diode: green light emitting diode: blue light emitting diode: first violet light emitting diode = 44.54
: The luminous flux ratio was 24.57: 16.48: 14.41 (see FIG. 19).

Then, when the average color rendering index was calculated using this relative spectral data, the average color rendering index Ra was 47 as shown in Table 1.
(Comparative example 1) (red + green + blue)
The average color rendering index was calculated in the same manner as in Example 1.

However, in this comparative example 1, it implemented using the wavelength-relative spectrum data of only the red light emitting diode, the green light emitting diode, and the blue light emitting diode without using the wavelength-relative spectrum data of the first violet light emitting diode. .

Moreover, as shown in Table 1, it implemented by the light beam ratio of red light emitting diode: green light emitting diode: blue light emitting diode = 46.28: 22.92: 30.80 (refer FIG. 20).
When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 1, the average color rendering index Ra was 42.

As is apparent from this result, as in the present invention, a blue light emitting diode having a different peak emission wavelength, that is, an illumination light source (Example 1) having a blue light emitting diode and a first violet light emitting diode is more conventional. It can be seen that the average color rendering index Ra is larger and the color rendering property is improved than the three light emitting diodes of red light emitting diode, green light emitting diode, and blue light emitting diode.
(Example 2) (red + green + blue + first violet color + second violet color)
The average color rendering index was calculated in the same manner as in Example 1.

  However, in this Example 2, by shifting the wavelength-relative spectrum data of the blue light emitting diode, as shown in the graph shown in FIG. 21, the wavelength of the first violet light emitting diode whose peak wavelength is 440 nm. -Relative spectral data and wavelength-relative spectral data of a second violet light emitting diode having a peak wavelength of 450 nm were obtained.

  As in Example 1, as shown in Table 1, red light emitting diode: green light emitting diode: blue light emitting diode: first violet light emitting diode: second violet light emitting diode: = 39.15: 21 .73: 12.94: 11.59: 14.59 (see FIG. 22).

When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 1, the average color rendering index Ra was 48.
As is clear from this result, compared to Example 1, when the second violet light emitting diode is added as in Example 2, the average color rendering index Ra is further increased, and the color rendering is improved. You can see that

Example 3 (Red + Green + Blue + First Violet + Yellow Green)
The average color rendering index was calculated in the same manner as in Example 1.
However, in Example 3, by shifting the wavelength-relative spectrum data of the red light emitting diode, the wavelength-relative spectrum data of the yellow-green light emitting diode having a peak wavelength of 565 nm is obtained as shown in FIG. It was.

Then, in the same manner as in Example 1, as shown in Table 2, red light emitting diode: green light emitting diode: blue light emitting diode: first violet light emitting diode: yellow green light emitting diode = 30.70: 9.59: The measurement was performed at a luminous flux ratio of 24.12: 8.82: 26.77 (see FIG. 24).

When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 2, the average color rendering index Ra was 91.
(Comparative Example 2) (Red + Green + Blue + Yellow Green)
In the same manner as in Example 3, the average color rendering index was calculated.

However, in Comparative Example 2, the wavelength-relative spectrum of only the red light emitting diode, the green light emitting diode, the blue light emitting diode, and the yellow green light emitting diode is used without using the wavelength-relative spectral data of the first violet light emitting diode. Performed with data.

  In addition, as shown in Table 2, red light emitting diode: green light emitting diode: blue light emitting diode: yellow green light emitting diode = 31.63: 8.51: 32.37: 27.49 25).

When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 2, the average color rendering index Ra was 88.
As is apparent from this result, as in the present invention, a blue light emitting diode having different peak emission wavelengths, that is, an illumination light source having a blue light emitting diode, a first violet light emitting diode, and a yellow green light emitting diode (Example 3) The first violet light emitting diode is added to the illumination light source (Comparative Example 2) in which the yellow green light emitting diode is added to the three red light emitting diodes of the conventional red light emitting diode, green light emitting diode, and blue light emitting diode. By doing this, it can be seen that the average color rendering index Ra is large and the average color rendering index Ra is 91, which is a high color rendering property.
(Comparative Example 3) (red + green + blue + crimson)
In the same manner as in Comparative Example 2, the average color rendering index was calculated.

However, in Comparative Example 3, a deep red light emitting diode was used instead of the yellow green light emitting diode.
However, in this comparative example 3, by shifting the wavelength-relative spectrum data of the red light emitting diode, as shown in the graph shown in FIG. 26, the peak wavelength is 685 nm of the wavelength-relative wavelength of the crimson light emitting diode. Spectral data was obtained.

  As in Example 1, as shown in Table 2, red light emitting diode: green light emitting diode: blue light emitting diode: crimson light emitting diode = 31.16: 16.67: 22.18: 29.99 (See FIG. 27).

When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 2, the average color rendering index Ra was 39.
As is clear from this result, as compared with the illumination light source (Comparative Example 1) having three colors of light emitting diodes of a conventional red light emitting diode, green light emitting diode, and blue light emitting diode, a deep red color is used as in Comparative Example 3. It can be seen that the average color rendering index Ra decreases when a light emitting diode is added.

This suggests the effectiveness of using two blue light emitting diodes having different peak emission wavelengths.
(Comparative Example 4) (Red + Green + Blue + Yellow Green + Crimson)
In the same manner as in Comparative Example 2, the average color rendering index was calculated.

However, in Comparative Example 4, in addition to the yellow-green light emitting diode, the deep red light emitting diode used in Comparative Example 3 was additionally used.
When the average color rendering index was calculated in the same manner as in Example 1, as shown in Table 2, the average color rendering index Ra was 88.

  As in Example 1, as shown in Table 1, red light emitting diode: green light emitting diode: blue light emitting diode: yellow green light emitting diode: deep red light emitting diode = 22.56: 6.01: 25. The ratio was 73: 23.23: 39.15 (see FIG. 28).

  As is apparent from this result, the deep red light emitting diode is compared with the illumination light source (Comparative Example 2) in which the yellow green light emitting diode is added to the conventional red light emitting diode, green light emitting diode, and blue light emitting diode. It can be seen that the average color rendering index Ra does not change even when the value is added (Comparative Example 4).

The preferred embodiment of the present invention has been described above, but the present invention is not limited to this. In the embodiment of the present invention, the case where a light emitting diode having a steep peak that does not contain a fluorescent material that converts light emitted from the light emitting diode into light having a wavelength longer than the wavelength of the light is used. If necessary, it is also possible to use a light emitting diode containing a fluorescent material. In addition, the illumination light source of the present invention has been described with respect to an embodiment applied to a light emitting element mounting package. However, not only the light emitting element mounting package but also a form of a bare chip, a form in which a light emitting diode is integrated with a member having a lens action, etc. It is also possible to use a lamp type or the like, and various changes and function additions can be made without departing from the object of the present invention.

FIG. 1 is a schematic plan view showing a first embodiment of the illumination light source of the present invention. 2 is a schematic cross-sectional view of the illumination light source of FIG. 1 taken along line XX. FIG. 3 is a chromaticity diagram corresponding to the illumination light source according to the first embodiment of the present invention. FIG. 4 is a spectral distribution diagram illustrating a state in which the simulation is performed by shifting the wavelength of the blue light emitting diode by 5 nm based on the actual measurement value of the blue light emitting diode. FIG. 5 is a perspective view of still another embodiment of the illumination light source of the present invention. FIG. 6 is a perspective view of still another embodiment of the illumination light source of the present invention. FIG. 7 is a schematic plan view showing still another embodiment of the illumination light source of the present invention. FIG. 8 is a spectral distribution diagram of an example of the illumination light source according to the first embodiment of the present invention. FIG. 9 is a spectral distribution diagram of another example of the illumination light source according to the first embodiment of the present invention. FIG. 10 is a schematic plan view showing a second embodiment of the illumination light source of the present invention. 11 is a schematic sectional view taken along line XX of the illumination light source of FIG. FIG. 12 is a chromaticity diagram corresponding to the illumination light source of the second embodiment of the present invention. FIG. 13 is a spectral distribution diagram of an example of the illumination light source according to the second embodiment of the present invention. FIG. 14 is a spectral distribution diagram of another example of the illumination light source according to the second embodiment of the present invention. FIG. 15 is a spectral distribution diagram showing wavelength-relative spectrum data of the red light emitting diode used in the example of the present invention. FIG. 16 is a spectral distribution diagram showing wavelength-relative spectrum data of the green light emitting diode used in the example of the present invention. FIG. 17 is a spectral distribution diagram showing wavelength-relative spectrum data of the blue light emitting diode used in the example of the present invention. FIG. 18 is a spectral distribution diagram showing the wavelength-relative spectrum data of the violet light-emitting diode obtained by shifting the wavelength-relative spectrum data of the blue light-emitting diode used in the example of the present invention. FIG. 19 is a spectral distribution diagram showing Example 1 of the present invention. FIG. 20 is a spectral distribution diagram showing Comparative Example 1 of the present invention. FIG. 21 is a spectral distribution diagram showing the wavelength-relative spectral data of the first violet light-emitting diode used in Example 2 of the present invention and the wavelength-relative spectral data of the second violet light-emitting diode. FIG. 22 is a spectral distribution diagram showing Example 2 of the present invention. FIG. 23 is a spectral distribution diagram showing wavelength-relative spectrum data of the yellow-green light emitting diode used in the example of the present invention. FIG. 24 is a spectral distribution diagram showing Example 3 of the present invention. FIG. 25 is a spectral distribution diagram showing Comparative Example 2 of the present invention. FIG. 26 is a spectral distribution diagram showing the wavelength-relative of the deep red light emitting diode used in the comparative example of the present invention. FIG. 27 is a spectral distribution diagram showing Comparative Example 3 of the present invention. FIG. 28 is a spectral distribution diagram showing Comparative Example 4 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light emitting element mounting board | substrate 10 Illumination light source 12 Light emitting element mounting package 14 Board | substrate 16 Reflector frame 18 Light emitting element accommodation recessed part 20 Light emitting diode 20A Red light emitting diode 20B Green light emitting diode 20C Blue light emitting diode 20D Violet light emitting diode 20E Yellow green light emitting diode 22A Light reflecting surface 22 Opening

Claims (8)

  An illumination light source comprising two or more blue light emitting diodes having different peak emission wavelengths among a plurality of types of light emitting diodes having different emission colors. An illumination light source having light emitting diodes of different types of emission colors,
A red light emitting diode,
A green light emitting diode,
Two or more blue light emitting diodes having different peak emission wavelengths;
The illumination light source according to claim 1, further comprising:   The two or more blue light emitting diodes having different peak emission wavelengths are two or more blue light emitting diodes having different peak emission wavelengths having a peak emission wavelength in a range of 380 to 480 nm. The illumination light source according to either 1 or 2.   The blue light emitting diode has a first blue light emitting diode having a peak emission wavelength greater than 450 nm and not more than 480 nm, and a second blue light emitting diode having a peak emission wavelength of 380 nm to 450 nm. The illumination light source according to claim 3. The red light emitting diode is a red light emitting diode having a peak emission wavelength in a range of 600 to 640 nm;
5. The illumination light source according to claim 1, wherein the green light emitting diode is a green light emitting diode having a peak emission wavelength in a range of 500 to 540 nm.   The illumination light source according to any one of claims 1 to 5, further comprising a yellow-green light emitting diode.   The illumination light source according to claim 6, wherein the yellow-green light-emitting diode is a yellow-green light-emitting diode having a peak emission wavelength in a range of 550 nm to 590 nm. The illumination light source according to claim 6 or 7, wherein the illumination light source has an average color rendering index Ra of 90 or more.

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