JP5099418B2 - Lighting device - Google Patents

Description

  The present invention relates to a lighting device using a light emitting element.

  LED lamps using light emitting diodes (LEDs) are rapidly expanding in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, and indoor / outdoor advertisements. When such an LED lamp is applied to various uses, it is important to obtain white light emission. Typical methods for realizing white light emission with LED lamps are (1) a method using three LED chips that emit light in blue, green and red colors, and (2) a blue light emitting LED chip between yellow and orange. And (3) a method of combining an ultraviolet light emitting LED chip and a blue, green and red three-color mixed phosphor.

  As the structure of the above-described white LED lamp, for example, a transparent resin mixed with a phosphor is poured into a cup-shaped frame equipped with an LED chip, and this is solidified to form a phosphor-containing resin layer containing the phosphor. The structure etc. which were made are proposed (for example, refer patent document 1). Also proposed is a structure in which a transparent resin mixed with a phosphor is formed into a sheet shape, which is fixed to, for example, a frame on which LED chips are arranged, and a phosphor-containing resin layer is formed. Furthermore, for the purpose of increasing the capacity, a structure called a chip on board (COB) in which a plurality of chips are mounted on a substrate (board) has been proposed. Also in this case, a phosphor-containing resin layer containing the phosphor is formed by filling a transparent resin mixed with the phosphor so as to be embedded in the concave portion in which the plurality of chips are disposed, and solidifying later. It is formed.

  In the white LED lamp as described above, the shade of white light actually obtained depends on the color temperature, and various types can be obtained from whitish white to white close to a light bulb color. And the color rendering properties of these white LED lamps also change. The color rendering property can be expressed by the average color rendering index Ra, and as a rule, the color rendering property is higher as the value is closer to 100. In view of such a situation, a variable color LED lamp capable of changing only the color temperature has been proposed (see, for example, Patent Document 2).

However, in the conventional variable color LED lamp, since only red is added to the white LED lamp, the color temperature can only be lowered with respect to white light. For this reason, the difference (deviation duv) from the black body radiation locus in the uv chromaticity diagram becomes large, and the quality of the color deteriorates, so that a practically usable variable color LED lamp has not yet been realized. It should be noted that the uv chromaticity diagram is considered so that the perceptual chromaticity difference is equal if the difference (duv) between the chromaticity coordinates of the two colors is the same.
JP 2001-148516 A JP 2004-55772 A

  An object of the present invention is to provide an illuminating device that can suppress a deviation from a black body radiation locus from increasing and can change a color temperature. It is another object of the present invention to provide a highly efficient lighting device without reducing the average color rendering index Ra value at an arbitrary color temperature.

The illumination device according to claim 1 includes a blue light emitting element that emits blue light, a white light emitting element that has a yellow phosphor covering the blue light emitting element, a red light emitting element that emits red light, and a green light emitting element. A green light emitting element that generates white light of a predetermined color temperature by controlling a current supplied to the white light emitting element, adjusts a current supplied to the red light emitting element and the green light emitting element, and emits the red light And a color temperature control means for controlling a color temperature by adjusting an output of light emitted from the element and the green light emitting element, and the color temperature control means controls a current supplied to the white light emitting element. When the color temperature is lowered by this, in the range where the lowered color temperature is higher than an arbitrary value, control is performed to adjust the output of light emitted from the red light emitting element and the green light emitting element, respectively. In the range below the temperature, is characterized by reducing the difference between the black body radiation locus performs control to increase the output of light emitted from the red light emitting element as it is the output of the light emitted from the green light emitting element.

The illumination device according to claim 2, and the illumination device according to claim 1, wherein the near-ultraviolet red light-emitting element has a near-ultraviolet light-emitting element that emits near-ultraviolet light and a near-ultraviolet excited red phosphor that covers the near-ultraviolet light-emitting element Is further provided.

According to the illumination device of claim 1, the light emitting device includes the white light emitting element, the red light emitting element, and the green light emitting element, and the current supplied to the red light emitting element and the green light emitting element is adjusted by the color temperature control means, By adjusting the output of light emitted from each element, the color temperature of the entire apparatus can be adjusted, and thus the degree of deviation from the black body radiation locus can be reduced. That is, even when the color temperature of the white light emitting element is lowered, the current supplied to the red light emitting element and the green light emitting element is controlled to control the output of red light and green light emitted from these light emitting elements. The deviation from the black body radiation locus can be reduced. The color temperature control means controls to adjust the output from the red light emitting element and the green light emitting element in the range higher than the arbitrary color temperature, and the output from the red light emitting element in the range lower than the arbitrary color temperature. By performing control to further increase the color temperature, the color temperature of the entire apparatus can be adjusted, and the degree of deviation from the black body radiation locus can be reduced.

  As described above, according to the illuminating device of the present invention, it is possible to provide an illuminating device that can suppress the deviation from the black body radiation locus and can change the color temperature.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

(First embodiment)
FIG. 1 is a block diagram schematically showing a first embodiment of the illumination device of the present invention.

  The lighting device 10 shown in FIG. 1 is adjacent to the white light emitting element 11 disposed in the center, the red light emitting element 12 disposed adjacent to the left side of the white light emitting element 11, and the right side of the white light emitting element 11. The green light emitting element 13 is arranged. These white light emitting element 11, red light emitting element 12, and green light emitting element 13 are each disposed on a substrate 14.

  The white light emitting element 11 includes a blue LED chip 111 and a phosphor-containing resin layer 112 formed so as to cover the blue LED chip 111. The phosphor-containing resin layer 112 is formed by containing a yellow phosphor 114 in the transparent resin 113. In the white light emitting element 11, the blue light emitted from the blue LED chip 111 excites the yellow phosphor 114 to emit yellow light, and white light is generated by mixing the blue light and the yellow light.

The yellow phosphor 114 does not mean a phosphor that emits strict yellow light, but a phosphor that emits a wide range of light from yellow light to orange light. Examples of such phosphors include YAG phosphors such as RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphor (RE represents at least one selected from Y, Gd, and La. The same applies hereinafter), AE ₂ Silicate phosphors such as SiO ₄ : Eu phosphors (AE is an alkaline earth element such as Sr, Ba, Ca, etc .; the same applies hereinafter), oxide phosphors (sialon phosphors, etc.), nitride phosphors (CaAlSiN ₃ : Eu etc.) can be exemplified.

  As the transparent resin 113, a silicone resin, an epoxy resin, or the like can be used. Appropriately heated to a predetermined temperature and cured before use. The particle size (particle diameter) of the yellow phosphor 114 is, for example, such that the average particle diameter is 10 to 20 μm. Thereby, the luminous efficiency of these phosphors, and further the luminous efficiency of the white light emitting element 11 is increased. However, it is not necessary for all of the phosphors 114 to be in this range, and about 70% or more of the whole may be in the above range.

  In addition, the blending ratio of the yellow phosphor 114 can be, for example, 5 to 20% by weight with respect to the transparent resin 113.

  The red light emitting element 12 has a red LED chip 121 at the bottom thereof. The red LED chip 121 can be sealed with the above-described transparent resin, or can be placed as it is in a space defined by the case constituting the red light emitting element 12 without sealing. Moreover, it can also be arranged in the white light emitting element 11.

  The green light emitting element 13 has a green LED chip 131 at the bottom thereof. The green LED chip 131 can be sealed with the above-described transparent resin, or can be placed as it is in a space defined by the case constituting the green light emitting element 13 without sealing. Moreover, it can also be arranged in the white light emitting element 11. Although not particularly shown in FIG. 1, circuit wiring for electrically controlling the blue LED chip 111, the red LED chip 121, and the green LED chip 131 is formed on the substrate 14. The circuit wiring can be directly formed on the substrate 14 when the substrate 14 exhibits insulation properties, but is formed via a predetermined insulating layer when the substrate 14 exhibits electrical conductivity.

  In the illuminating device 10 shown in FIG. 1, white light having a predetermined color temperature is generated by controlling the current supplied (flowed) to the white light emitting element 11, and the red light emitting element 12 and the green light emitting element 13 are controlled. By adjusting the current to flow and controlling the output of light emission from these light emitting elements, the degree of deviation from the black body radiation locus in the light emission of the entire illumination device 10 can be reduced.

  In addition, in the lighting device 10 shown in FIG. 1, the white light emitting element 11 emits white light having a color defined by the color temperature, and the red light emitting element 12 and the green light emitting element 13 cause red and green color changes. By tightening, color rendering can be imparted. Therefore, for example, even when the color temperature is decreased by controlling the current that flows through the white light emitting element 11, the current that flows through the red light emitting element 12 and the green light emitting element 13 is controlled to generate red light emitted from these light emitting elements. The deviation can be reduced by controlling the green color temperature.

  More specifically, in the range where the color temperature is higher than a predetermined color temperature (for example, 4200 K), control is performed to adjust the light emission outputs from the red light emitting element 12 and the green light emitting element 13, respectively. Then, in the range lower than the predetermined color temperature of 4200K (for example, 3000K), the output from the green light emitting element 13 is left as it is, and the control for increasing the light emission output from the red light emitting element 12 is performed. For example, 4200K which is a predetermined color temperature may be included in a range higher than the predetermined color temperature or may be included in a lower range. By controlling the color temperature in this way, the deviation from the black body radiation locus can be reduced.

  In FIG. 1, the white light emitting element 11 is disposed in the center, the red light emitting element 12 is disposed on the left side, and the green light emitting element 13 is disposed on the right side. However, the arrangement order is appropriately changed. be able to. For example, the red light emitting element 12 may be disposed on the right side of the white light emitting element 11 and the green light emitting element 13 may be disposed on the left side of the white light emitting element 11. Further, the red light emitting element 12 and the green light emitting element 13 can be arranged adjacent to each other on either the left or right side of the white light emitting element 11.

  FIG. 2 is a configuration diagram schematically showing a modification of the illumination device shown in FIG. Components that are the same as or similar to those in the lighting device shown in FIG. 1 are denoted by the same reference numerals. In the lighting device 10 shown in FIG. 1, the white light emitting element 11, the red light emitting element 12, and the green light emitting element 13 are arranged independently, but in the present embodiment shown in FIG. In one case, a blue LED chip 111, a red LED chip 121, and a green LED chip 131 are arranged, and the white light emitting element 11, the red light emitting element 12, and the green light emitting element 13 are formed without being separated from each other. .

  In the present embodiment, the blue LED chip 111 is disposed at the center, the red LED chip 121 is disposed on the left side, and the green LED chip 131 is disposed on the right side thereof. Note that this arrangement can be appropriately changed as described above, and the red LED chip 121 is arranged on the right side of the blue LED chip 111 and the green LED chip 131 is arranged on the left side of the blue LED chip 111. it can. Further, the red LED chip 121 and the green LED chip 131 may be arranged on either the left or right side of the blue LED chip 111. Note that the LED chips 111, 121, and 131 of the respective colors are arranged on the substrate 14, respectively.

Moreover, in the illuminating device 20 of this embodiment, the fluorescent substance containing resin layer 112 is formed so that the blue LED chip 111, the red LED chip 121, and the green LED chip 131 may be coat | covered. As described above, the phosphor-containing resin layer 112 is formed by containing the yellow phosphor 114 in the transparent resin 113. The blue light emitted from the blue LED chip 111 excites the yellow phosphor 114 to emit yellow light, and white light is generated by mixing the blue light and the yellow light. The yellow phosphor 114 does not mean a phosphor that emits strict yellow light, but a phosphor containing a wide range of light from yellow light to orange light. Examples of such phosphors include YAG phosphors such as RE ₃ (Al, Ga) ₅ O ₁₂ : Ce phosphors, silicate phosphors such as AE ₂ SiO ₄ : Eu phosphors, and oxide phosphors (sialons). Examples thereof include nitride phosphors (such as CaAlSiN ₃ : Eu) and the like.

  As the transparent resin 113, a silicone resin, an epoxy resin, or the like can be used, and the resin is appropriately heated to a predetermined temperature and cured. The particle diameter of the yellow phosphor 114 is preferably adjusted so that the average particle diameter is, for example, 10 to 20 μm. By adjusting the particle size, the light emission efficiency of the yellow phosphor 114 and the light emission efficiency of the white light emitting element 11 are increased. However, it is not necessary for all of the yellow phosphors 114 to be within this range, and about 70% or more of the whole may be within the above range. In addition, the blending ratio of the yellow phosphor 114 can be, for example, 5 to 20% by weight with respect to the transparent resin 113. Although not particularly shown in FIG. 2, circuit wiring for electrically controlling the blue LED chip 111, the red LED chip 121, and the green LED chip 131 is formed on the substrate 14. The circuit wiring can be directly formed on the substrate 14 when the substrate 14 exhibits insulation properties, but is formed via a predetermined insulating layer when the substrate 14 exhibits electrical conductivity.

  In the illuminating device 20 shown in FIG. 2, by controlling the current that flows through the blue LED chip 111, white light having a predetermined color temperature is emitted, and the current that flows through the red LED chip 121 and the green LED chip 131. By adjusting and controlling the output of the light emission from the red light emitting element 12 and the green light emitting element 13, the degree of deviation from the black body radiation locus in the light emission of the entire lighting device 20 can be reduced. Specifically, the blue LED chip 111 generates a blue light having a color specified by the color temperature, and the red LED chip 121 and the green LED chip 131 cause red and green color changes to adjust the color temperature. It is possible to reduce the deviation from the black body radiation locus when the illumination device 20 is viewed as a whole.

  In the above embodiment, the red light emitting element 12 and the green light emitting element 13 are both configured such that the LED chip itself emits red light and green light. The red light emitting element 12 and the green light emitting element 13 may be configured by using a chip and coating it with a red phosphor and a yellow phosphor. That is, red light and green light are emitted by mixing the blue light from the blue LED chip and the red light and yellow light emitted from the red phosphor and yellow phosphor by excitation of the blue light, respectively. You may comprise as follows.

(Second Embodiment)
FIG. 3 is a block diagram schematically showing a second embodiment of the illumination device of the present invention. Note that the same reference numerals are used for the same or similar components as those of the lighting device shown in FIG.

  The illuminating device 10 of the first embodiment shown in FIG. 1 has a white light emitting element 11, a red light emitting element 12, and a green light emitting element 13, but the illuminating device 30 of the second embodiment shown in FIG. The white light emitting element 11 disposed on the left side, the red light emitting element 12 disposed adjacent to the left side of the white light emitting element 11, and the orange light emitting light emitting orange light disposed adjacent to the right side of the white light emitting element 11. Element 31. The white light emitting element 11, the red light emitting element 12, and the orange light emitting element 31 are all disposed on the substrate 14. Since the white light emitting element 11 and the red light emitting element 12 are configured in the same manner as in the first embodiment described above, description thereof is omitted.

  The orange light emitting element 31 has an orange LED chip 311 at the bottom thereof. The orange LED chip 311 can be sealed with the above-described transparent resin, or can be placed as it is in a space defined by the case constituting the orange light emitting element 31 without sealing. Moreover, it can also be arranged in the white light emitting element 11.

  In the illuminating device 30 shown in FIG. 3, by controlling the current supplied to the white light emitting element 11, white light having a predetermined color temperature is generated, and the current passed through the red light emitting element 12 and the orange light emitting element 31. By adjusting the above and controlling the output of light emission from these light emitting elements, it is possible to reduce the degree of deviation from the black body radiation locus in the light emission of the illumination device 30 as a whole.

  3 emits white light having a hue defined by the color temperature mainly by the white light emitting element 11, and causes red and orange color changes by the red light emitting element 12 and the orange light emitting element 31. By tightening, color rendering can be imparted. For example, even when the color temperature is lowered by controlling the current flowing through the white light-emitting element 11, the currents flowing through the red light-emitting element 12 and the orange light-emitting element 31 are controlled to generate red light emitted from these light-emitting elements. By controlling the orange output, the deviation from the black body radiation locus can be reduced.

  More specifically, in the range where the color temperature is higher than a predetermined color temperature (for example, 4200K), only the light emission output from the orange light emitting element 31 is adjusted, and in the range lower than the predetermined color temperature (for example, 3000K). Controls the adjustment of the light emission output from the red light emitting element 12 in addition to the adjustment of the light emission output from the orange light emitting element 31. By controlling the color temperature in this way, the deviation from the black body radiation locus can be reduced.

  In FIG. 3, the white light emitting element 11 is arranged at the center, the red light emitting element 12 is arranged on the left side, and the orange light emitting element 31 is arranged on the right side, but the arrangement order is appropriately changed. be able to. For example, the red light emitting element 12 may be disposed on the right side of the white light emitting element 11, and the orange light emitting element 31 may be disposed on the left side of the white light emitting element 11. Further, the red light emitting element 12 and the orange light emitting element 31 may be arranged adjacent to each other on either the left or right side of the white light emitting element 11.

  In addition, the blue LED chip 111, the red LED chip 121, and the orange LED chip 311 are disposed in one case that defines the lighting device 30, and the white light emitting element 11, the red light emitting element 12, and the orange light emitting element 31 are separated from each other. It can be set as the structure formed without separating.

  Further, in the above embodiment, the red light emitting element 12 and the orange light emitting element 31 are both configured such that the LED chip itself emits red light and orange light. The red light emitting element 12 and the orange light emitting element 31 may be configured by using a chip and coating it with a red phosphor and an orange phosphor. That is, red light and orange light are emitted by mixing the blue light from the blue LED chip and the red light and orange light emitted from the red phosphor and orange phosphor upon excitation of the blue light, respectively. You may comprise.

(Third embodiment)
FIG. 4 is a block diagram schematically showing a third embodiment of the illumination device of the present invention. Note that the same reference numerals are used for the same or similar components as those of the lighting device shown in FIG.

  4, the red light emitting element 12 is disposed adjacent to the left side of the white light emitting element 11, and the right side of the white light emitting element 11 is adjacent to the right side of the white light emitting element 11. A green light emitting element 13 is arranged. Further, a near ultraviolet light emitting element 41 is arranged on the left side of the red light emitting element 12. The white light emitting element 11, the red light emitting element 12, the green light emitting element 13, and the near ultraviolet light emitting element 41 are all disposed on the substrate 14. Since the white light emitting element 11, the red light emitting element 12, and the green light emitting element 13 are each configured in the same manner as in the first embodiment, description thereof is omitted.

  The near-ultraviolet light emitting element 41 has a near-ultraviolet LED chip 411 that emits near-ultraviolet light, and a phosphor-containing resin layer 412 formed so as to cover the near-ultraviolet LED chip 411. The phosphor-containing resin layer 412 contains, in the transparent resin 413, a near-ultraviolet-emitting red phosphor (hereinafter, referred to as a near-ultraviolet red phosphor) 414 that emits red light when excited by near-ultraviolet light. It is formed by letting.

Examples of such near ultraviolet red phosphors 414 include oxysulfide phosphors such as La ₂ O ₃ S: Eu ³⁺ phosphors, ^germanate phosphors such as manganese-activated magnesium fluorogermanate ( 2.5MgO · MgF ₂ : Mn ⁴⁺ ) or the like can be used. Further, nitride phosphors (for example, AE ₂ Si ₅ N ₈ : Eu or CaAlSiN ₃ : Eu) capable of obtaining various emission colors depending on the composition, oxynitride phosphors (eg, Y ₂ Si ₃ O ₃ N ₄ : Ce), sialon-based phosphors (eg, AEx (Si, Al) ₁₂ (N, O) ₁₆ : Eu), and the like can also be used.

  In the near-ultraviolet light emitting element 41, near-ultraviolet light emitted from the near-ultraviolet LED chip 411 excites the near-ultraviolet red phosphor 414 to emit red light, and the near-ultraviolet light-emitting element 41 as a whole emits red light. To emit light.

  As the transparent resin 413, a silicone resin, an epoxy resin, or the like can be used. These resins are used by appropriately heating to a predetermined temperature and curing. The particle diameter of the near ultraviolet red phosphor 414 is preferably adjusted so that the average particle diameter is, for example, 10 to 20 μm. As a result, the light emission efficiency of the near ultraviolet red phosphor 414 and the light emission efficiency of the near ultraviolet light emitting element 41 are increased. However, it is not necessary for all of the near-ultraviolet red phosphors 414 to be in this range, and about 70% or more of the total may be in the above range. Although not specifically shown in FIG. 4, circuit wiring for electrically controlling the blue LED chip 111, the red LED chip 121, the green LED chip 131, and the near-ultraviolet LED chip 411 is provided on the substrate 14. Is formed. The circuit wiring can be directly formed on the substrate 14 when the substrate 14 exhibits insulation properties, but is formed via a predetermined insulating layer when the substrate 14 exhibits electrical conductivity.

  In the illuminating device 40 shown in FIG. 4, by controlling the current flowing through the white light emitting element 11, white light having a predetermined color temperature is generated, and the current flowing through the red light emitting element 12 and the green light emitting element 13 is generated. By adjusting and controlling the output of light emission from these light emitting elements, the degree of deviation from the black body radiation locus in the light emission of the entire illumination device 40 can be reduced. Specifically, the white light emitting element 11 emits white light having a color defined by the color temperature, and the red light emitting element 12 and the green light emitting element 13 cause red and green color changes. Further, the color temperature is changed by the near ultraviolet light emitting element 41.

  For example, even when the current flowing through the white light emitting element 11 is controlled to lower the color temperature, the current flowing through the red light emitting element 12 and the green light emitting element 13 and further the current flowing through the near ultraviolet light emitting element 41 are controlled. Thus, by controlling the color temperature of each color emitted from these light emitting elements, the deviation from the black body radiation locus can be reduced when viewed in the entire illumination device 40.

  In the present embodiment, the near-ultraviolet light emitting element 41, the red light emitting element 12, the white light emitting element 11, and the green light emitting element 13 are arranged from the left side, but the arrangement order thereof can be changed as appropriate.

  In the present embodiment, the light emitting elements are separated from each other. However, as shown in FIG. 2, the blue LED chip 111, the red LED chip 121, the green LED chip 131, and the vicinity are arranged in a single case. The ultraviolet LED chips 411 can also be arranged and configured. Further, in the third embodiment, the red light emitting element 12 and the green light emitting element 13 are both configured such that the LED chip itself emits red light and green light. The red light emitting element 12 and the green light emitting element 13 may be configured by using a blue LED chip and coating it with a red phosphor and a yellow phosphor. That is, red and green light are emitted by mixing the blue light from the blue LED chip and the red light and yellow light emitted from the red phosphor and yellow phosphor upon excitation of the blue light, respectively. It may be configured.

  In the illuminating device 40 shown in FIG. 4, according to the near-ultraviolet light emitting element 41, a broad red color can be obtained by changing the color temperature, so that the near light emitting element 40 and the green light emitting element 13 are not used. By using only the ultraviolet light emitting element 41, it is possible to reduce the degree of deviation from the black body radiation locus when viewed in the entire illumination device 40. Further, even when the current flowing through the white light emitting element 11 is controlled to lower the color temperature, the current flowing through the near ultraviolet light emitting element 41 is controlled, and the red output (color temperature) emitted from the light emitting element is controlled. Accordingly, it is possible to reduce the deviation of light emission (deviation from the black body radiation locus) when viewed with the entire illumination device 40. In such a case, the white light emitting element 11 and the near-ultraviolet light emitting element LED 41 may be disposed adjacent to each other in, for example, an illumination device configured as shown in FIG.

  Next, examples of the present invention and evaluation results thereof will be described.

Examples 1 and 2
In this example, a lighting device having the configuration shown in FIG. 1 was produced, and the change in color temperature and the decrease in color quality were evaluated. The change and adjustment of the color temperature are performed by adjusting the current supplied to the red LED chip 121 of the red light emitting element 12 and the green LED chip 131 of the green light emitting element 13 and controlling the output of light emission from these light emitting elements. It was. The decrease in color quality was evaluated by the deviation (duv) from the black body radiation locus. This evaluation was performed when the color temperature of the white light emitted from the white light emitting element 11 was decreased from 6700K to 4200K and 3000K, respectively.

  The wavelength of blue light from the blue LED chip 111 was 460 nm. The peak wavelength of red light from the red LED chip 121 of the red light emitting element 12 was 630 nm, and the peak wavelength of green light from the green LED 131 chip of the green light emitting element 13 was 520 nm. Further, the phosphor-containing resin layer 112 of the white light-emitting element 11 is obtained by containing a yellow phosphor having a main wavelength of 540 nm, a yellow phosphor having a main wavelength of 585 nm, and a red phosphor having a main wavelength of 650 nm in the silicone resin. It was. The evaluation results are shown in Table 1.

  In the column of color temperature control in Table 1, ◯ indicates that there is an output by supplying current, and ◎ indicates that the supply and output of current are large. X indicates that there is no light emitting element and no output. The same applies to Tables 2 to 5 below.

Comparative Examples 1 and 2
In this comparative example, the orange light emitting element 13 is used in place of the red light emitting element 12 and the green light emitting element 13 in the illumination device configured as shown in FIG. (Duv) was evaluated. The orange light emitting element 12 has an orange LED chip (orange chip), and the main wavelength of the orange light from the orange LED chip was 595 nm. The results are shown in Table 2.

  From the comparison of the results shown in Table 1 and Table 2, in the illumination devices of Examples 1 and 2, the deviation from the black body radiation locus is controlled by controlling the output of light emission from the red light emitting element 12 and the green light emitting element 13. It can be seen that (duv) can be zero.

  This will be described with reference to the chromaticity diagram shown in FIG. An arrow A indicates an illumination device in the case where the color temperature of light emitted from the white light emitting element 11 is reduced from 6700K to 4200K while adjusting the output of light emitted from the red light emitting element 12 and the green light emitting element 13 in Example 1. 10 shows a change in chromaticity. When the color temperature of light emitted from the white light emitting element 11 is further reduced to 3000 K, the change in chromaticity indicated by the arrow C is shown, and the deviation (duv) from the black body radiation locus (shown by the curve D) gradually increases. Will be. On the other hand, in the second embodiment, as in the first embodiment, when the color temperature is 6700K to 4200K, the output of light emission from the red light emitting element 12 and the green light emitting element 13 is adjusted, and the color temperature is 4200K to 3000K. Up to this point, since the output of the light emission from the red light emitting element 12 is increased, the chromaticity of the light emission as the entire illumination device 10 shows a change along the black body radiation locus D as indicated by the arrow B, The deviation (duv) from the blackbody radiation locus is very close to zero.

Examples 3-7
In Examples 3 to 5, the illumination device 10 having the configuration shown in FIG. It was. The decrease in color quality was evaluated by the deviation (duv) from the black body radiation locus, as in Examples 1 and 2. Moreover, the structure of the light emitting element of each color in these illuminating devices was the same as in Examples 1 and 2. The evaluation results are shown in Table 3.

  In Examples 6 to 7, the illumination device having the configuration shown in FIG. 3 was manufactured, and the deviation (duv) from the black body radiation locus was evaluated, and the color rendering properties (average color rendering index Ra) at that time were evaluated. Examined. The wavelength of blue light from the blue LED chip 111 was 460 nm. The red light emitting element 12 and the orange light emitting element 31 have a red LED chip 121 and an orange LED chip 311, respectively. The main wavelength of the red light from the red LED chip 121 is 630 nm, and the orange light from the orange LED chip 311. The dominant wavelength of light was 595 nm. Further, the phosphor-containing resin layer 112 of the white light-emitting element 11 is obtained by containing a yellow phosphor having a main wavelength of 540 nm, a yellow phosphor having a main wavelength of 585 nm, and a red phosphor having a main wavelength of 650 nm in the silicone resin. It was. The change and adjustment of the color temperature are performed by adjusting the current supplied to the red LED chip 121 of the red light emitting element 12 and the orange LED chip 311 of the orange light emitting element 31 and controlling the output of light emission from these light emitting elements. It was. The decrease in color quality was evaluated in the same manner as in Examples 3-5. An evaluation result is shown in Table 3 similarly to Examples 3-5.

Comparative Examples 3-5
In this comparative example, in the lighting device having the configuration shown in FIG. 1, the color temperature change and the color quality decrease were evaluated, and the color rendering properties (average color rendering evaluation number Ra) at that time were examined. In addition, the structure of each light emitting element in these illuminating devices was made the same as that of the comparative examples 1 and 2, and the fall of the color quality was evaluated similarly to Examples 1 and 2. The evaluation results are shown in Table 4.

  From the comparison of the results shown in Table 3 and Table 4, in the illumination devices of Examples 3 to 5, the average color rendering index Ra is set to 70 by controlling the output of light emission from the red light emitting element 12 and the green light emitting element 13. It can be seen that the above can be improved and the deviation (duv) from the blackbody radiation locus can be made substantially zero. In the illumination devices of Examples 6 and 7, the average color rendering index Ra can be increased to 70 or more by controlling the output of light emission from the red light emitting element 12 and the orange light emitting element 31. Further, It can be seen that the deviation (duv) from the blackbody radiation locus can be made substantially zero.

Examples 8-10
In this example, an illumination device having the configuration shown in FIG. 4 was produced, and the color temperature change and the color quality decrease were evaluated, and the color rendering properties (average color rendering index Ra) at that time were examined. The change and adjustment of the color temperature adjust the current supplied to the red LED chip 121 of the red light emitting element 12, the green LED chip 131 of the green light emitting element 13, and the near ultraviolet LED chip 411 of the near ultraviolet light emitting element 41. This was done by controlling the output of light emission from the light emitting element. The decrease in color quality was evaluated by the deviation (duv) from the black body radiation locus. This evaluation was performed when the color temperature of the white light emitted from the white light emitting element 11 was decreased from 6700K to 4200K and 3000K, respectively.

  Moreover, the white light emitting element 11, the red light emitting element 12, and the green light emitting element 13 were configured in the same manner as in Examples 1 and 2. Further, the near-ultraviolet light emitting element 41 is configured by covering a near-ultraviolet LED chip 411 having a main wavelength of 395 nm with a germanate phosphor that is a near-ultraviolet red phosphor 414. This germanate phosphor was contained in a silicone resin to form a phosphor-containing resin layer 412. The evaluation results are shown in Table 5.

  As is apparent from Table 5, by providing a near-ultraviolet light emitting element 41 in addition to the white light emitting element 11, the red light emitting element 12 and the green light emitting element 13, extremely high color rendering properties (average color rendering index) It can be seen that Ra) can be obtained, and that the deviation (duv) from the blackbody radiation locus can be made substantially zero.

  As mentioned above, although this invention was demonstrated in detail based on the specific example, this invention is not limited to the said specific example, All the deformation | transformation and changes are possible unless it deviates from the category of this invention.

It is a block diagram which shows schematically 1st Embodiment of the illuminating device of this invention. It is a block diagram which shows schematically the modification of the illuminating device shown in FIG. It is a block diagram which shows schematically 2nd Embodiment of the illuminating device of this invention. It is a block diagram which shows schematically 3rd Embodiment etc. of the illuminating device of this invention. It is a chromaticity diagram showing the chromaticity of light emission of the illuminating device obtained in Example 1, 2 of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10, 20, 30, 40 ... Illuminating device, 11 ... White light emitting element, 12 ... Red light emitting element, 13 ... Green light emitting element, 14 ... Board | substrate, 111 ... Blue LED chip, 112 ... Phosphor containing resin layer, 113 ... Transparent Resin, 114 ... phosphor, 121 ... red LED chip, 131 ... green LED chip, 31 ... orange light emitting element, 311 ... orange LED chip, 41 ... near ultraviolet light emitting element, 411 ... near ultraviolet LED chip, 412 ... containing phosphor Resin layer, 413, transparent resin, 414, red phosphor for near ultraviolet.

Claims (2)

A blue light-emitting element that emits blue light, and a white light-emitting element having a yellow phosphor that covers the blue light-emitting element;
A red light emitting element that emits red light;
A green light emitting element that emits green light;
The white light having a predetermined color temperature is generated by controlling the current supplied to the white light emitting element, the current supplied to the red light emitting element and the green light emitting element is adjusted, and the red light emitting element and the green light emitting element Color temperature control means for controlling the color temperature by adjusting the output of light emission from;
Equipped with,
When the color temperature is lowered by controlling the current supplied to the white light emitting element, the color temperature control means is configured to reduce the red color element and the green light emitting element in a range where the lowered color temperature is higher than an arbitrary value. In the range lower than an arbitrary color temperature, the light emission output from the green light emitting element remains unchanged and the light emission output from the red light emitting element is increased. An illumination device characterized by reducing deviation from a black body radiation locus . The illumination device according to claim 1, further comprising a near-ultraviolet light-emitting element that emits near-ultraviolet light and a near-ultraviolet red light-emitting element having a near-ultraviolet excited red phosphor that covers the near-ultraviolet light-emitting element. .

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