JP2013161909A - Led lighting unit and led lighting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve high color rendering properties without reducing luminous efficiency.SOLUTION: The LED lighting unit includes first and second LED light-emitting elements 11, 21 having the wavelengths of outgoing light different from each other, first and second phosphors combined with the first LED light-emitting element 11 and emitting light having wavelengths different from each other by receiving the outgoing light from the first LED light-emitting element 11, and third and fourth phosphors combined with the second LED light-emitting element 21 and emitting light having wavelength different from each other and different from those of the outgoing light from the first and second LED light-emitting elements by receiving the outgoing light from the second LED light-emitting element 21. A first LED device 1 consisting of the first LED light-emitting element 11 and the first and second phosphors, and a second LED device 2 consisting of the second LED light-emitting element 21 and the third and fourth phosphors are arranged alternately.

Description

  The present invention relates to an improvement in a structure for realizing high color rendering without reducing luminous efficiency in an LED lighting unit and an LED lighting device.

  As the LED lighting device, for example, the one shown in Japanese Patent Application Laid-Open No. 2009-206037 has been proposed by the present applicant. As described in paragraphs [0017] to [0034] of the above publication, the LED illumination device includes a blue LED light emitting element and a first LED device made of a yellow fluorescent substance, and a blue LED. An LED light emitting element that emits light and a second LED device that includes two types of phosphors that emit green and orange fluorescence are prepared, and these LED devices are arranged alternately.

  In such an LED lighting device, the first LED device emits white light (color temperature: about 5400K) in which blue light from the LED light emitting element and yellow light from the phosphor are mixed, The LED device 2 emits warm white light (color temperature: about 3300 K) in which blue light from the LED light emitting element and green light and orange light from each phosphor are mixed. In the mixed region of warm white light, these mixed color lights (color temperature: about 4200 K) are synthesized.

  In this case, since the wavelength of the mixed-color light exists widely from the short wavelength region to the long wavelength region of visible light, according to the LED illumination device, balanced irradiation light that is gentle to the human eye is provided. Can be obtained.

  By the way, recently, high color rendering properties have been required even in LED lighting devices. In general, there are an average color rendering index (Ra) and a special color rendering index (Ri) as indices for evaluating the color rendering. The higher the numerical value, the closer to natural light (evaluation number 100), the higher the color rendering is evaluated. For example, in the printing industry, Ra ≧ 95 and Ri ≧ 90 are required as evaluation numbers.

  However, in the above-mentioned publication, the wavelength region is simply broadened by combining two types of LED devices that emit outgoing light having different color temperatures, white light and warm white light, and obtaining these mixed color lights. Therefore, although it is preferable for general indoor lighting, it is not a lighting device suitable for realizing high color rendering properties of Ra ≧ 95 and Ri ≧ 90.

  On the other hand, it is possible to further broaden the wavelength region by increasing the types of phosphors combined with the LED light-emitting element, and to approximate the spectrum distribution of natural light. For example, an LED light emitting element that emits blue light having a wavelength of around 420 [nm] is prepared, and the peak wavelengths of fluorescence from each phosphor are 460 [nm], 515 [nm], 520 [nm], and 620 [ nm] and 635 [nm] are prepared, and these phosphors are blended in the sealing resin of the LED light-emitting element, whereby high color rendering of Ra ≧ 95 and Ri ≧ 90. It is possible to realize sex.

  However, in this case, the phosphor content increases as the types of phosphors combined with the LED light-emitting element increase, so that there is a problem that the light emission efficiency decreases. The luminous efficiency in the above example is 44 lm / W, which is lower than the commercially available high color rendering fluorescent lamp AAA type (luminous efficiency: 58 lm / W).

  The present invention has been made in view of such a conventional situation, and the problem to be solved by the present invention is an LED lighting unit and an LED lighting device capable of realizing high color rendering without reducing luminous efficiency. Is to provide.

  In order to solve the above-described problems, the present invention provides a first LED light emitting element which is combined with a first LED light emitting element and a first LED light emitting element having different wavelengths of emitted light from each other in an LED lighting unit. The first and second phosphors that emit light having different wavelengths and the second LED light emitting element are combined and the emitted light from the second LED light emitting element is incident. In addition, third and fourth phosphors that emit light having wavelengths different from those of the first and second phosphors and different from each other are provided (see claim 1).

  In the present invention, each of the first and second LED light emitting elements is composed of a blue light emitting diode (see claim 2).

  In the present invention, the first and third phosphors are both phosphors emitting green fluorescence, and the second and fourth phosphors are both phosphors emitting red fluorescence (see claim 3). ).

  In the present invention, a first LED device comprising a combination of the first LED light emitting element and the first and second phosphors, and a first LED device comprising a combination of the second LED light emitting element and the third and fourth phosphors. Two LED devices are alternately arranged along the arrangement direction of the first and second LED devices (see claim 4).

  In the present invention, the directivity angles of the adjacent first and second LED devices partially overlap (refer to claim 5).

  Moreover, the LED lighting device according to the present invention includes the LED lighting unit according to claim 1 (see claim 6).

  As described above, according to the present invention, the phosphor is combined with each of the LED light emitting elements, so that it is possible to prevent a reduction in light emission efficiency, and the combination of each LED light emitting element and each phosphor. The wavelength region of the entire LED lighting unit can be broadened, and high color rendering can be realized.

1 is an overall perspective view of an LED lighting device employing an LED lighting unit according to an embodiment of the present invention. It is a top view which shows the state which arranged the 1st, 2nd LED device (device 1, 2) which comprises the said LED illumination unit (FIG. 1) alternately by linear form. It is a longitudinal cross-sectional view of the said 1st LED device (device 1). It is a longitudinal cross-sectional view of a said 2nd LED device (device 2). It is a block block diagram of the said LED illumination unit. It is a figure for demonstrating each directivity angle of each adjacent LED device, and the state in which they overlap. It is a table | surface which compares and compares Ra and Ri of the LED lighting unit (device 1 + 2) by a present Example with Ra and Ri of the LED lighting unit (device 1 + 1 and device 2 + 2) of a comparative example. It is a graph which compares and compares the spectrum distribution of the LED illumination unit (device 1 + 2) by a present Example with the spectrum distribution of the LED illumination unit (device 1 + 1 and device 2 + 2) of a comparative example. It is a figure which plots and shows each emitted light of the LED illumination unit (device 1 + 2) by a present Example, and the LED illumination unit (device 1 + 1 and device 2 + 2) of a comparative example on a chromaticity diagram.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
FIG. 1 shows an LED (Light Emitting Diode) illumination device to which an LED illumination unit according to an embodiment of the present invention is applied. As shown in the figure, the LED lighting device 50 includes a base 51, a translucent cover 52 covering the base 51, and end plates 53 attached to both ends of the base 51 and the translucent cover 52. doing. A cable 54 for wiring is inserted through the through hole formed in the end plate 53.

  As shown in FIG. 2, the LED lighting device 50 includes a substrate 55 that extends linearly. A plurality of first LED devices 1 and second LED devices 2 are mounted on the substrate 55. These first and second LED devices 1 and 2 constitute an LED illumination unit according to this embodiment. The LED devices 1 and 2 are linearly arranged at a predetermined interval, and are alternately arranged along the arrangement direction.

  As shown in FIG. 3, the first LED device 1 includes a first LED chip (LED light emitting element) 11 mounted inside a package 1 </ b> A and a lead frame 13 connected to the LED chip 11 by a bonding wire 12. And a sealing material 14 filled in the package 1A. Here, a pair of chips is provided as the first LED chip 11.

  The first LED chip 11 is composed of a blue light emitting diode, and specifically, a light emitting diode having a wavelength of 448 [nm] is used. The sealing material 14 is blended with first and second phosphors. As these phosphors, those that emit fluorescence having different wavelengths when light emitted from the first LED chip 11 is incident are used. In this example, a phosphor that emits green fluorescence, specifically, a phosphor having a peak wavelength of 515 [nm] is used as the first phosphor, and a phosphor that emits red fluorescence as the second phosphor. Specifically, a phosphor having a peak wavelength of 620 [nm] is used. The first phosphor is, for example, a silicate phosphor, and the second phosphor is, for example, a nitride phosphor.

The specific composition of the sealing material 14 in the first LED device 1 is as follows.
Sealant alone: 1: 1 mixture of KER2500A and KER2500B
(Specifically 2g each)
Phosphor with wavelength 515 [nm]: 0.400 [g]
Phosphor with wavelength 620 [nm]: 0.042 [g]
(The ratio of each phosphor is 9.5: 1)
KER2500A / B is a trade name of Shin-Etsu Chemical Co., Ltd.

  As shown in FIG. 4, the second LED device 2 includes a second LED chip (LED light emitting element) 21 mounted inside the package 2 </ b> A, and a lead frame 23 connected to the LED chip 21 by a bonding wire 22. And a sealing material 24 filled in the package 2A. Here, a pair of chips is provided as the second LED chip 21.

  The second LED chip 21 is composed of a blue light emitting diode as in the case of the first LED chip 11, but the wavelength of the emitted light is different from that of the first LED chip 11. Specifically, a light emitting diode having a wavelength of 465 [nm] is used as the second LED chip 21. The sealing material 24 contains third and fourth phosphors. As these phosphors, when the light emitted from the second LED chip 21 is incident, the phosphor emits fluorescence having a wavelength different from the wavelength of the light emitted from the first and second phosphors. Is used. In this example, a phosphor that emits green fluorescence, specifically, a phosphor having a peak wavelength of 520 [nm] is used as the third phosphor, and a phosphor that emits red fluorescence as the fourth phosphor. Specifically, a phosphor having a peak wavelength of 635 [nm] is used. The third phosphor is, for example, a silicate phosphor, and the fourth phosphor is, for example, a nitride phosphor.

The specific composition of the sealing material 24 in the second LED device 2 is as follows.
Sealant alone: 1: 1 mixture of KER2500A and KER2500B
(Specifically 2g each)
Phosphor with wavelength 520 [nm]: 0.650 [g]
Phosphor with wavelength 635 [nm]: 0.035 [g]
(The ratio of each phosphor is 18.6: 1)

  As shown in FIG. 5, a common power circuit 56 is connected to the first LED device 1 and the second LED device 2. In addition, you may make it provide each LED device 1 and 2 with a separate power supply circuit.

  FIG. 6 shows the directivity angles of the first and second LED devices 1 and 2. In this example, the first and second LED devices 1 and 2 both have a directivity angle of about 120 degrees, and a part of the directivity angles of the adjacent LED devices 1 and 2 overlap each other. (See the shaded area in the figure).

  Next, FIG. 7 shows the results of measuring the chromaticity coordinates (x, y coordinates), average color rendering index (Ra) and special color rendering index (Ri) of the emitted light for the LED unit configured as described above. Show. In the figure, for convenience of illustration, the table is divided into two upper and lower tables.

  In FIG. 7, “device 1 + 2” indicates an LED unit including the first and second LED devices 1 and 2 according to this embodiment, and “device 1 + 1” and “device 2 + 2” are comparative examples, “Device 1 + 1” indicates a configuration in which two first LED devices 1 are arranged, and “Device 2 + 2” indicates an arrangement in which two second LED devices 2 are arranged. The average color rendering index Ra is indicated by an average value of R1 to R8, and the special color rendering index Ri is indicated by R9 to R15, respectively.

  As shown in FIG. 7, the device 1 + 2 according to the present embodiment has Ra = 96.666 and Ra ≧ 95 with respect to the average color rendering index. As for the special color rendering index, Ri = 88.435 for R12 and does not reach 90, but Ri ≧ 90 is achieved for R9 to R11 and R13 to R15. . From this result, it can be said that the device 1 + 2 according to the present embodiment realizes high color rendering. In addition, the luminous efficiency of the emitted light of the device 1 + 2 is 55 lm / W, and a decrease in the luminous efficiency is prevented.

  On the other hand, the device 1 + 1 as a comparative example has Ra = 93.469 with respect to the average color rendering index and does not achieve Ra ≧ 95, and with respect to the special color rendering index, particularly with respect to R11, Ri. = 80.074, which is much lower than 90. Further, in the device 2 + 2 of the comparative example, Ra = 87.395 with respect to the average color rendering index, which is considerably lower than 95, and Ri ≧ 90 is achieved with respect to the special color rendering index. Are only R11 and R14, and all others are smaller than 90.

  Next, FIG. 8 shows a comparison of the spectrum of the emitted light of each device described above. As shown in the figure, in the device 1 + 2 of this example, each spectrum is distributed with a substantially uniform intensity in the wavelength range of visible light having an emission wavelength of 380 [nm] to 780 [nm]. Is broadened. That is, it can be said that a spectral distribution close to the spectral distribution of natural light is realized.

  Next, FIG. 9 shows a plot of the chromaticity coordinates of each device in FIG. 7 with the x axis on the horizontal axis and the y axis on the vertical axis. As shown in the figure, the device 1 + 2 has a hue and saturation intermediate between those of the device 1 + 1 and the device 2 + 2.

  As described above, according to the present embodiment, the first and second LED light emitting elements 11 and 21 each have two types of phosphors (first and second phosphors or third and fourth phosphors). Are combined. In general, it is known that the luminous efficiency decreases as the number of phosphors combined in one LED light-emitting element increases. In the case of this embodiment, a total of four types of fluorescent light, which are first to fourth phosphors, are used. The body is distributed to the first and second LED light emitting elements 11, 21 respectively. As a result, the number of phosphors combined in one LED light-emitting element has been reduced to two, thereby preventing a reduction in light emission efficiency. Further, as shown in FIG. 8, the peak wavelengths of the device 1 + 1 and the device 2 + 2 are slightly shifted from each other, and by combining waveforms with shifted peak wavelengths, the wavelength region of the entire LED lighting unit is broadened. And high color rendering.

  In the above embodiment, the case where the wavelength of the third phosphor is larger than the wavelength of the first phosphor and the wavelength of the fourth phosphor is larger than the wavelength of the second phosphor has been described as an example. However, the application of the present invention is not limited to this. In the present invention, for example, when the wavelength of the third phosphor is larger than the wavelength of the first phosphor and the wavelength of the second phosphor is larger than the wavelength of the fourth phosphor, The present invention is also applicable when the wavelength of the body is larger than the wavelength of the third phosphor and the wavelength of the fourth phosphor is larger than the wavelength of the second phosphor.

  Moreover, in the said Example, although the example using two types of LED light emitting elements called the 1st, 2nd LED light emitting element was shown, you may make it use three or more types of LED light emitting elements.

  Furthermore, in the said Example, although the example which made two types of fluorescent substance combined with one LED light emitting element was shown, if it is in the range which can reduce luminous efficiency, it will be 3 in one LED light emitting element. You may make it combine the fluorescent substance of more than a kind.

  The present invention is useful for an LED lighting unit for realizing high color rendering properties without reducing luminous efficiency.

1: 1st LED device 11: 1st LED chip (LED light emitting element)
14: Sealing material

2: Second LED device 21: Second LED chip (LED light emitting element)
24: Sealing material

50: LED lighting device

JP 2009-206037 A (see paragraphs [0017] to [0034])

Claims (6)

An LED lighting unit,
First and second LED light emitting elements having different wavelengths of emitted light from each other;
First and second phosphors that are combined with the first LED light-emitting element and receive light emitted from the first LED light-emitting element and emit light having different wavelengths; and
A wavelength that is combined with the second LED light-emitting element and the light emitted from the second LED light-emitting element is incident, and is different from the wavelengths of the light emitted from the first and second phosphors and different from each other Third and fourth phosphors that emit light of
LED lighting unit with In claim 1,
The first and second LED light emitting elements are both composed of blue light emitting diodes,
An LED lighting unit characterized by that. In claim 1,
The first and third phosphors are both phosphors emitting green fluorescence, and the second and fourth phosphors are both phosphors emitting red fluorescence.
An LED lighting unit characterized by that. In claim 1,
A first LED device comprising a combination of the first LED light emitting element and the first and second phosphors, and a first LED device comprising a combination of the second LED light emitting element and the third and fourth phosphors. Two LED devices are alternately arranged along the arrangement direction of the first and second LED devices,
An LED lighting unit characterized by that. In claim 4,
The directivity angles of the adjacent first and second LED devices partially overlap,
An LED lighting unit characterized by that.   An LED lighting device comprising the LED lighting unit according to claim 1.

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