JP2014157752A - Led illumination apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve the problem in which an LED device used in an LED illumination apparatus is still poor in color rendering, one reason of which is loss in characteristics due to interaction between used fluorescent bodies, and another reason of which is that an LED device constituted by a blue LED and a fluorescent body is poor in a spectrum of cyan.SOLUTION: An LED device in which a fluorescent body has a separation type structure so as to reduce interaction between fluorescent bodies as little as possible, and an LED device emitting light of cyan color are used in combination, thereby providing an LED illumination apparatus with super high color rendering.

Description

  The present invention relates to an LED lighting device such as an LED bulb, and relates to an lighting device having a high luminous flux value (lumen value) and good color rendering.

  In recent years, lighting devices using LEDs have been put into practical use and are being replaced by incandescent bulbs and fluorescent lamps as well as mercury lamps and halogen lamps. The reason is that the same brightness can be obtained with low power consumption, and it becomes a trump card for eco-products that can significantly reduce the amount of carbon dioxide emissions that cause global warming. For example, the equivalent brightness of a 60W class incandescent bulb can be realized with a 9W LED bulb. In this way, if all lighting is replaced by LED lighting, the reduction target of carbon dioxide emissions can be easily achieved, but the obstacle is that the price difference between the two lighting devices is still large. It is. Considering the lifespan, the price difference is much smaller, so lighting in special places is being replaced by LED lighting because it can also reduce the labor costs of replacing it.

Halogen lamps used in store downlights and spot lighting use the light emitted when a filament is energized and incandescent in the same way as incandescent bulbs, so the color rendering index for evaluating color reproducibility is high. Since the temperature of the filament can be made higher than that of a general incandescent bulb, it can be brightened by about 50%. It also has a long life. The reason is that the filament is made of tungsten, and when incandescent, tungsten sublimes, and in a general incandescent bulb, it is deposited on the glass of the bulb. However, since halogen lamps contain a small amount of halogen gas together with an inert gas in the bulb, they become tungsten halide, and this substance has a high vapor pressure and does not precipitate, but again separates into tungsten and halogen near the filament. This is because the halogen cycle of returning to the filament is repeated.
The color temperature of the halogen lamp is about 2700K to 3000K, the color rendering is the best among the lamps, and this light source is used in a place where color reproducibility is important.

  When replacing halogen lamps (also referred to as halogen lamps) with LED bulbs, the use of halogen lamps is used for lighting in places where color reproducibility is important, such as store lighting and production lighting. And color rendering. As for the brightness, the luminous efficiency of the LED element increases, and the actual value of the LED device for illumination (LED electronic component for illumination) has reached 150 lm / W (5000 K) or 100 lm / W (3000 K) so that there is no problem. It seems, but if color rendering properties are taken into account, the luminous efficiency decreases. For example, a lighting LED device having a color temperature of 3000 K and a device with an average color rendering index Ra = 80 can have a luminous efficiency of 100 lm / W, while a device with Ra = 85 has a low value of 80 lm / W. In other words, if the color rendering is improved, the luminous efficiency is lowered.

As a method for obtaining white light using a semiconductor light emitting element (also referred to as an LED element or an LED chip), as a first step, a YAG-based phosphor powder that emits yellow light that is complementary to blue and blue light is used. It was used. However, the pseudo white light produced by the blue light of the LED element and the yellow light of the YAG phosphor has a low average color rendering index Ra of about 70 units, and the natural color of the object is reproduced by the illumination. Was impossible. The reason why Ra is low is that the red component of light is small.
Therefore, as a second step, phosphor powder that emits green and red light, which are the three primary colors of light, is used with the blue light of the LED element, and the blue light of the LED element and broad from the two types of phosphors are used. Green light and red light with a good light spectrum make up white light, and its average color rendering index Ra has good luminous efficiency and has been improved to 80 units, but the color rendering type with Ra reaching 90 units Then, the luminous efficiency is considerably deteriorated. The reason is as follows.
The LED device for illumination used in LED bulbs that are currently in widespread use is an LED element that emits blue light, a green phosphor that emits broad green light that is excited by the blue light, and a broad red light that is excited by blue light. It is comprised from the red type fluorescent substance which emits. Since the brightness of light is also affected by human visual sensitivity, it is expressed by a luminous flux considering visual sensitivity, and the unit is lm (lumen). Human visibility is highest for yellow light with a wavelength of 555 nm, and low for blue light and red light. Therefore, the lumen value decreases as the red light component due to the phosphor increases. In order to improve the color rendering, generally, long-wave red light is necessary among red light, and the lumen value is lowered accordingly. This is the first factor that the luminous flux value decreases when the color rendering is improved.

  As the third step, if the brightness of the semiconductor light emitting device emitting violet light or ultraviolet light is increased, three kinds of phosphor powders emitting three primary colors of light with violet light or ultraviolet light are used. Can be expected to be 100, which is equivalent to a halogen lamp. Even now, high color rendering LED bulbs using purple LED devices are on the market. More on that later. (See Non-Patent Document 1)

There is an important second factor that the luminous flux value decreases when the color rendering is improved. This is described below.
Generally, a green phosphor and a red phosphor are mixed and used at a blending ratio that can reproduce the color temperature. In this way, when the green phosphor and the red phosphor are mixed and used, an interaction occurs between the phosphors. That is, broad green light is emitted from the green phosphor excited by the blue light from the LED element, but part of the light can also be excitation light of the red phosphor.
FIG. 10 shows a remarkable example of such an interaction. Sample 5 in FIG. 10 is a spectrum when green phosphors and red phosphors are mixed in the same amount, and Sample 6 is a sum of single spectra of green phosphors and red phosphors (that is, both). Spectrum when there is no interaction between the phosphors. The optical characteristic values of both spectra are as follows: Sample 5 has a luminous flux value = 69.0 lm, Ra = 69.0, color temperature = 2300 K, Sample 6 has a luminous flux value = 72.2 lm, Ra = 93.5, and color temperature = 4096. 9K.
As can be seen from the emission spectrum data No. 3, when the same amount is mixed (that is, when the mixing ratio of the green phosphor and the red phosphor is 1: 1), the green light component does not appear at all and red light is emitted. Only the ingredients are larger. That is, the green light is reabsorbed by the red phosphor and converted into red light. As a result, the color temperature is reddish, 2300K, the color reproducibility is deteriorated to Ra = 69.0, and the luminous flux value is also reduced.

The following two things can be understood from this example.
First, Sample 5 mixed with a phosphor is converted from blue light emitted from the LED element into broad green light by the green phosphor, and further, this light is converted into broad red light by the red phosphor. Since the light passes through the two-stage conversion, there is a loss due to the two-stage conversion. That is, there is a loss in the luminous efficiency of white light as a total.

Secondly, the disappearance of the green light component not only changes the color temperature but also greatly impairs the average color rendering index Ra.
Such interaction between phosphors has the effect of degrading the color rendering and deteriorating the luminous efficiency. That is, in order to replace a light source having a high color rendering property and a high luminous flux value such as the halogen lamp described above with an LED bulb, it is important to have a structure that eliminates the interaction between phosphors.

Since most white LED devices currently in widespread use are in the second step, it is difficult to achieve high color rendering and high luminous flux as described above. Therefore, a method of satisfying high color rendering by adding a device using a red light emitting LED element (denoted as a red LED device) to an existing white LED device having a high luminous flux has been taken. Such an example is shown in Patent Document 1.
In this case, a red LED device is additionally used for two white LED devices having different color temperatures (for example, two color temperatures of about 3000K and 4000K). The two white LED devices here are those of the second step described above, and contain twice the loss due to the interaction between the phosphors (since using two color temperature white LED devices). Yes. Also, the red LED device has a sharp spectrum, the total spectrum is unbalanced, and the red light emitting LED element and the blue light emitting LED element have different VFs, so that the driver circuit is complicated. There is also.
Reference 2 describes an example of an illumination device including a blue LED device, a blue-green LED device, an orange LED device, and a red LED device, and further includes a phosphor in order to obtain LED illumination with high luminous flux and high color rendering. However, controlling several types of LED devices becomes very complicated because the static characteristics, temperature, and life characteristics of each LED device are different, which is not practical.
Further, in Non-Patent Document 1, in the third step, a semiconductor light emitting element that emits purple light (referred to as a purple LED chip) is made of a phosphor that emits blue light, broad blue light, green light, and red light. It is mixed with resin and applied in a paste form to provide LED lighting with high color rendering properties. This will be described again in the comparison of the examples. However, the purple LED chip is disadvantageous in that it is lower in luminance and more expensive than the blue LED chip. In addition, since a large amount of purple light having a shorter wavelength than blue light is emitted, there is a drawback that the silicon resin is greatly damaged and has a short life.

JP 2012-3908 A JP 2006-261702 A

"MUSEUM COM SPOT LIGHT", CCS Corporation

When reproducing a halogen lamp with the above-mentioned white LED device for illumination in the second step, a color temperature of 3000 K, a color rendering property of Ra = 90 or more, and a luminous efficiency of 80 lm / W or more, preferably color rendering Ideally, the average value from R1 to R15 is 95 or more and the luminous efficiency is 60 lm / W or more. Conventional LED devices for lighting mainly have a structure in which phosphors for reproducing color temperature and color rendering are mixed with LED elements that emit blue light and arranged on the light extraction surface of the LED elements. In consideration of the interaction between the phosphors, there is no LED device for illumination or LED bulb that is in an optimum condition. In order to realize the ideal LED device for illumination described above, the luminous efficiency of the LED elements and the conversion efficiency of the phosphor powder (efficiency of emitting light of a specific color when excited by blue light) are improved. The structure of the LED device that minimizes the interaction of the LED and the design of the LED lighting device such as the LED bulb are important.
Further, in the case of the white LED device for illumination in the second step, there remains a problem that even if the interaction between the phosphors is optimized, the cyan spectrum becomes a valley and becomes insufficient.
Further, even if purple LED elements and ultraviolet LED elements are further increased in brightness and cost and blue phosphors are used as phosphors, blue phosphors, green phosphors, yellow phosphors will be used. It is the same that the interaction between the phosphor and the red phosphor needs to be considered more than ever.

  The present invention has been made in view of the above-described circumstances, and in particular, as an LED lighting device such as an LED bulb, has a configuration in which the interaction between phosphors is reduced and supplements the cyan spectrum. An object of the present invention is to provide an LED lighting device such as an LED bulb with improved performance.

The invention of claim 1
In a light emitting device comprising a semiconductor light emitting element that emits blue light and a phosphor that emits intrinsic light that is excited by the light of the semiconductor light emitting element,
As the intrinsic light,
A green phosphor that emits green light,
A yellow phosphor that emits yellow light, and
Two or more kinds of phosphors having different emission colors are used among red phosphors emitting red light, and these phosphors have a specific structure that suppresses the interaction between the phosphors, that is, phosphor separation type A light emitting device having a structure (referred to as a phosphor-separated LED device);
A semiconductor light emitting element (referred to as a cyan color LED chip) that emits blue to cyan light having a peak wavelength different from that of the blue light, or a light emitting device using the cyan color LED chip (referred to as a cyan color LED device). LED lighting device characterized by comprising:

  In the second step, the white LED device is obtained by mixing a green phosphor (or yellow phosphor) and a red phosphor in a silicon resin at a certain ratio, and on a light extraction surface of an LED element that emits blue light. In the structure (mixed white LED device) applied to, the light emission efficiency and color rendering are impaired due to the interaction between the green phosphor and the red phosphor. Among the mixed white LED devices, a device having the best color rendering property at a color temperature of about 3000K is, for example, XSM9527 (Sample 7 in FIG. 11) manufactured by Xicato, and the luminous efficiency (lm / W value) and The color rendering index (R1 to R15) is as shown in Table 1, for example.

  The average value from R1 to R15 is 93.8. As described above, the color rendering property is considerably improved, but the light emission efficiency is as extremely low as 38.6 lm / W. This is because there is an interaction between the green phosphor and the red phosphor as described above. Also, the numerical values of R11 and R12 due to the lack of the cyan color spectrum are low.

  In order to improve this, it is important to eliminate the interaction between the green phosphor and the red phosphor, and the phosphor-separated LED device (Sample 2 in FIG. 8) having a phosphor-separated structure that satisfies the interaction is important. The luminous efficiency (lm / W value) and the color rendering index (R1 to R15) are as shown in Table 2 in the same measurement system.

The average value from R1 to R15 is 94.4. The luminous efficiency is as high as 52.3 lm / W. As described above, the color rendering property and the light emission efficiency are improved by adopting the phosphor separation type structure. However, the deficiency of the cyan color spectrum still remains and R11 and R12 are lower than the other evaluation numbers.
In order to improve this, it can be improved by adding the spectrum of the cyan color LED chip or the cyan color LED device emitting this wavelength as a separate configuration, that is, as a light emitting device different from the phosphor separation type LED device. It is.

The invention of claim 2
The phosphor-separated LED device is
Blue light is emitted, has two main surfaces facing each other, one main surface is a light extraction surface, and the other main surface is an electrode formation surface, and is equal to or larger than the light extraction surface. A phosphor-containing film piece having two opposing main surfaces, one main surface being a light incident surface and the other main surface being a light output surface, is overlapped so that the light extraction surface and the light input surface are opposed to each other. Arranged and configured
The phosphor-containing film piece is divided into a plurality of pieces perpendicular to the main surface, and each of the divided regions (denoted as divided regions) is a fluorescent material selected from a green phosphor, a red phosphor, and a yellow phosphor. The LED lighting device according to claim 1, wherein the specific structure is configured by allocating one body to configure the phosphor-containing film piece.

  A structure that forms a phosphor film piece is the most realistic to realize as a single LED device for illumination as a structure that eliminates the interaction between the phosphors. For example, a paste obtained by mixing red phosphor powder in a silicon resin on a plastic sheet by screen printing is printed and cured to form a film-like phosphor-containing film piece. Thereafter, a plurality of blade-width grooves are inserted using a dicer to grind a part of the phosphor-containing film piece and remove the phosphor. Thereafter, the removed red phosphor portion is coated with a paste obtained by mixing a green phosphor powder in a silicon resin and cured. In this way, a phosphor-containing film piece formed by separating the red phosphor region and the green phosphor region is obtained. If this is arranged on the light extraction surface of the semiconductor light emitting element (LED element), a light emitting device having almost no interaction between the red phosphor and the green phosphor can be obtained. In order to add a blue phosphor region or a yellow phosphor region to this, the above method may be repeated.

The invention of claim 3
2. The LED illumination device according to claim 1, wherein a peak wavelength of the cyan color LED chip is in a range of 465 nm to 500 nm.

  The peak wavelength of the cyan color LED chip used to add a cyan color spectrum that is lacking in the spectrum of the phosphor-separated LED device emits the blue light used in the phosphor-separated LED device. Although it depends on the peak wavelength of the semiconductor light emitting device, the range of 465 nm to 500 nm is preferable. In particular, when a peak wavelength near 450 nm is used for the phosphor-separated LED device, a range of 470 nm to 490 nm is preferable. The cyan color LED chip may be used directly on a mounting substrate in a chip-on-board form, or may be used as a cyan color LED device using the cyan color LED chip.

The invention of claim 4
In a light emitting device comprising a semiconductor light emitting element that emits blue light and a phosphor that emits intrinsic light that is excited by the light of the semiconductor light emitting element,
As the intrinsic light,
A green phosphor that emits green light,
A yellow phosphor that emits yellow light, and
Two or more kinds of phosphors having different emission colors are used among red phosphors emitting red light, and these phosphors have a specific structure that suppresses the interaction between the phosphors, that is, phosphor separation type A light emitting device having a structure (referred to as a phosphor-separated LED device);
A light emitting device comprising a semiconductor light emitting device emitting purple light (referred to as a purple LED chip) and a blue phosphor emitting blue light having a broad wavelength distribution excited by light from the semiconductor light emitting device (blue phosphor) LED lighting device, characterized in that it is described as an LED device.

As a method of adding a cyan color spectrum, there is a method using the above-mentioned cyan color LED chip. Generally, the emission spectrum from the LED chip is sharp, and the wavelength range included in the LED chip is narrow and the optimum wavelength LED chip. Sorting is necessary. Instead, it is better to use a light emitting device made of a blue phosphor that emits light having a broad wavelength distribution including blue to cyan, which is excited by light from the purple LED chip, to a purple LED chip that emits purple light. And the like, and more preferable color rendering properties can be obtained.

The LED lighting device of the present invention is an LED device used in the LED lighting device.
A phosphor-separated LED device in which no interaction occurs between the phosphors;
By constructing with a cyan color LED chip that supplements the cyan color spectrum lacking in the spectrum of the phosphor-separated LED device and a cyan color LED device using the cyan color LED chip, A color rendering LED illumination device can be realized. And this LED lighting apparatus is suitable for illumination of places where color rendering properties such as museums and museums are important as LED bulbs, linear light sources and spotlights.
In addition, in order to obtain a cyan color spectrum that is lacking in phosphor-separated LED devices, a purple LED chip and a blue phosphor that emits broad blue light are used rather than a cyan LED chip. Since the configuration includes a broad blue to cyan spectral component, the LED illumination device has a better color rendering property.

It is a layout of the substrate of the LED lighting device of the first embodiment of the present invention. It is a figure of an example of a fluorescent substance separated type LED device, (a) is a top view seen from the top, (b) is sectional drawing in line AA. It is a figure of an example of a cyan-type LED device, (a) is a top view seen from the top, (b) is sectional drawing in line AA. It is a figure of an example of a cyan color LED device, (a) is the top view seen from the top, (b) It is a side view. It is the layout of the board | substrate of the LED lighting apparatus of 2nd Embodiment of this invention. It is a figure of an example of a fluorescent substance separation type LED device and a cyan system color LED device (chip on board). It is a figure of an example of a blue type | system | group fluorescent LED device, (a) is the top view seen from the top, (b) is sectional drawing in line AA. It is emission spectrum data No1 of a light-emitting device. It is emission spectrum data No2 of a light-emitting device. This is emission spectrum data No3 of the light emitting device. This is emission spectrum data No. 4 of the light emitting device.

  Hereinafter, embodiments of a light emitting device of the present invention will be described in detail in the order of first and second embodiments with reference to the drawings.

First, the board | substrate arrangement | positioning figure of the LED lighting apparatus of 1st Embodiment is shown in FIG.
This LED illumination device 1 is arranged in a circle with a substrate diameter of 15.5 mm, and includes nine phosphor-separated LED devices 2 as shown in FIG. 2 and cyan-based color LED devices 3 as shown in FIG. Nine are used. A pair of each of the phosphor-separated LED device 2 and the cyan LED device 3 has a spectrum of Sample 1 shown in FIG. In the phosphor-separated LED device 2 alone, the spectrum is shown as Sample 2 in FIG.

The phosphor-separated LED device 2 emits blue light having a wavelength of about 450 nm and a wavelength of about 450 nm. For example, a blue LED chip having a size of about 1 mm × 1 mm × 0.34 mm is used, and the device size is about 2.6 mm × The structure is 2.6 mm × 0.45 mm and shown in FIG. It is composed of a separation type phosphor film 23, a transparent resin 22 made of silicon resin, and a white resin 20 having a reflective wall in which titanium oxide is mixed with silicon resin. Mounting on an external substrate such as an aluminum base substrate is performed using solder on the electrode 24 of the blue LED chip.
In the separation-type phosphor film 23, the divided regions 23a, 23c, and 23e are red phosphor regions, the divided region 23b is a green phosphor, and the divided region 23d is a yellow phosphor. The size of the phosphor film is a square having a side of about 2.4 mm and a thickness of about 0.1 mm. The divided area of the red phosphor is about 1.5 × 2.4 mm ² , the divided area of the green phosphor is about 0.6 × 2.4 mm ² , and the divided area of the yellow phosphor is about 0.3 × 2. The area of the divided region of the red phosphor is the widest at 0.4 mm ² . The red phosphor is, for example, a mixture in which CaAlSi (ON) ₃ : Eu and CaAlSiN ₃ : Eu are mixed at an optimal weight ratio and dispersed in a silicon resin to a concentration of 55% by weight. The green phosphor uses, for example, CaSc ₂ O ₄ : Ce and is dispersed in a silicon resin so as to have a concentration of 55% by weight. The yellow phosphor, for example, uses La ₃ Si ₆ N ₁₁ : Ce. It is dispersed in silicone resin to a concentration of 55% by weight.
The characteristics of the phosphor-separated LED device 2 are those having a color temperature of about 3000 K, an average color rendering index Ra = 94.9, R9 = 98.3, and a luminous flux value of 54.9 lm (when If = 350 mA). . (See Table 2)

The cyan color LED device 3 has the structure shown in FIG. 3 and emits cyan color light having a wavelength of 473.0 nm, for example, a cyan color LED chip having a size of about 0.35 mm × 0.47 mm × 0.16 mm. 32 is used, and the device size is about 0.74 mm × 0.55 mm × 0.26 mm. It is composed of a transparent resin 31 made of silicon resin and a white resin 30 having a reflecting wall in which titanium oxide is mixed with silicon resin. Mounting on the external substrate is performed using solder on the electrode 33 of the cyan LED chip 32. The flowing current is about 10 mA.
Table 3 shows values obtained by measuring the luminous efficiency (lm / W value) and the color rendering index (R1 to R15) of the LED lighting device 1 using the same measurement system as in Table 2. The color temperature is about 3000K.

The average value from R1 to R15 is 97.2. The luminous efficiency is 53.2 lm / W. In this way, by adding the cyan color LED device 3 to the phosphor-separated LED device 2, the cyan color spectrum is added, the values of R11 and R12 are improved, and the color rendering property is extremely high. It becomes.
To compare with this, the color rendering index (catalog value) of “MUSEUM COM SPOT LIGHT” of “natural light LED” color temperature 3000K using a purple LED chip sold by CCS, which is disclosed in Non-Patent Document 1. ) Is shown in Table 4.

The average value from R1 to R15 is 95.9. The luminous efficiency is 40 lm / W or less.
As described above, the LED of the phosphor separation-type LED device and the cyan color LED device have better average values and luminous efficiencies from the color rendering index R1 to R15 than the “natural light LED” using the purple LED chip. A lighting device is possible. Further, the LED illumination apparatus of the present invention constituted by a device using blue and cyan color LED chips is superior in terms of catalog life and cost.
Here, the LED device having a structure not using the substrate shown in FIG. 3 is used as the cyan color LED device used together with the phosphor-separated LED device 2, but the surface-mount type chip LED 40 shown in FIG. 4 may be used. However, the one 51 using a cyan LED chip like a chip-on-board may be used. However, in the case of the chip LED 40, the size is large and the price is high, and in the case of the chip-on-board 51, the mounting substrate needs to be plated with gold, and the cost is increased.

Next, the board | substrate arrangement | positioning figure of the LED lighting apparatus of 2nd Embodiment is shown in FIG.
This LED illumination device 50 is arranged in a circle with a substrate diameter of 15.5 mm, and directly mounts nine phosphor-separated LED devices 52 and a cyan color LED chip 60 as shown in FIG. 6 on a wiring board. Nine cyan color LED devices 51 connected by wires 61 and covered with a transparent resin 62 to form a chip-on-board are used. Each pair of the phosphor-separated LED device 52 and the cyan color LED device 51 has a spectrum shown in Sample 3 shown in FIG. Only the phosphor-separated LED device 52 has a spectrum shown as Sample 4 in FIG.

The phosphor-separated LED device 52 has substantially the same structure as that shown in FIG. 2, but the separable phosphor film 63 is designed to have a color temperature of 4000K.
That is, the divided regions 63a and 63c are red phosphors, and the divided region 63b is a green phosphor. The size of the phosphor film is a square having a side of about 2.4 mm and a thickness of about 0.1 mm. The divided area of the red phosphor is about 1.55 × 2.4 mm ² , the divided area of the green phosphor is about 0.85 × 2.4 mm ² , and the area of the divided area of the red phosphor is the largest. As the red phosphor, for example, CaAlSi (ON) ₃ : Eu is used and dispersed in a silicon resin to have a concentration of 55% by weight. As the green phosphor, for example, CaSc ₂ O ₄ : Ce is used, which is dispersed in a silicon resin to a concentration of 55% by weight.
The characteristics of the phosphor-separated LED device 52 are those of a color temperature of about 4000 K, an average color rendering index Ra = 96.1, R9 = 95.0, and a luminous flux value of 59.5 lm (If = 350 mA). .

The cyan color LED device 51 uses a cyan color LED chip having a size of about 0.26 mm × 0.48 mm × 0.12 mm, for example, which emits cyan color light having a wavelength of 473.0 nm. The transparent resin 62 is a silicon resin. The flowing current is about 10 mA.
Table 5 shows values obtained by measuring the luminous efficiency (lm / W value) and the color rendering index (R1 to R15) of the LED lighting device 50 using the same measurement system as in Table 2. The color temperature is about 4000K.

The average value from R1 to R15 is 96.8. The luminous efficiency is 56.7 lm / W. In this manner, by adding the cyan-based color LED device 51 to the phosphor-separated LED device 52, a cyan color spectrum is added, and the LED illumination device has good color rendering.
However, although the emission spectrum of the LED illumination device 50 is shown in Sample 3 of FIG. 9, the emission spectrum from the blue LED chip used in the phosphor-separated LED device 52 (high peak shape with a peak wavelength of 445 nm). Therefore, if the emission spectrum of the cyan color LED device 51 (the peak having a peak wavelength of 473 nm) is further increased, the color rendering index R becomes worse. By optimizing the height of these two spectra, the color rendering index R will be even better than the values in Table 5.

Since the phosphor-separated LED devices 2 and 52 use blue LED chips, the blue light spectrum has only components from the blue LED chips. The spectrum from the blue LED chip is sharp and contains few wavelength components, so the cyan spectrum is insufficient. In order to compensate for this, cyan-color LED devices 3 and 51 are added. However, since the spectrum from the LED chip is sharp, an optimum wavelength must be selected. In order to solve this problem, as shown in FIG. 7, a blue phosphor-containing resin that emits blue light having a broad wavelength distribution with purple light on a purple LED chip 72 having an emission peak wavelength in the vicinity of 400 nm. The blue phosphor LED device 70 coated with 71 is used. As a specific blue phosphor, for example, (Sr, Ba) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu is used and dispersed in a silicon resin to have a concentration of 55% by weight.
In FIG. 7, bumps are formed on the electrodes of the purple LED chip, which are used as mounting electrodes 73 on the external substrate. The purple LED chip is mounted like the chip-on-board shown in FIG. Potting may be performed by mixing a phosphor based on silicon resin into a paste.

1,50 LED lighting device 2, 3, 40, 51, 52, 70 Light emitting device 20, 30 Reflecting wall 21, 32, 60, 72 Semiconductor light emitting element (LED element)
22, 31, 62 Transparent resin 23, 63 Phosphor-containing film pieces 24, 33, 73 Electrode 71 Phosphor-containing resin

Claims (4)

In a light emitting device comprising a semiconductor light emitting element that emits blue light and a phosphor that emits intrinsic light that is excited by the light of the semiconductor light emitting element,
As the intrinsic light,
A green phosphor that emits green light,
A yellow phosphor that emits yellow light, and
Two or more kinds of phosphors having different emission colors are used among red phosphors emitting red light, and these phosphors have a specific structure that suppresses the interaction between the phosphors, that is, phosphor separation type A light emitting device having a structure (referred to as a phosphor-separated LED device);
A semiconductor light emitting element (referred to as a cyan color LED chip) that emits blue to cyan light having a peak wavelength different from that of the blue light, or a light emitting device using the cyan color LED chip (referred to as a cyan color LED device). LED lighting device characterized by comprising: The phosphor-separated LED device is
Blue light is emitted, has two main surfaces facing each other, one main surface is a light extraction surface, and the other main surface is an electrode formation surface, and is equal to or larger than the light extraction surface. A phosphor-containing film piece having two opposing main surfaces, one main surface being a light incident surface and the other main surface being a light output surface, is overlapped so that the light extraction surface and the light input surface are opposed to each other. Arranged and configured
The phosphor-containing film piece is divided into a plurality of pieces perpendicular to the main surface, and each of the divided regions (denoted as divided regions) is a fluorescent material selected from a green phosphor, a red phosphor, and a yellow phosphor. The LED lighting device according to claim 1, wherein the specific structure is configured by allocating one body to configure the phosphor-containing film piece.   The LED illumination device according to claim 1, wherein the peak wavelength of the cyan color LED chip is in a range of 465 nm to 500 nm. In a light emitting device comprising a semiconductor light emitting element that emits blue light and a phosphor that emits intrinsic light that is excited by the light of the semiconductor light emitting element,
As the intrinsic light,
A green phosphor that emits green light,
A yellow phosphor that emits yellow light, and
Two or more kinds of phosphors having different emission colors are used among red phosphors emitting red light, and these phosphors have a specific structure that suppresses the interaction between the phosphors, that is, phosphor separation type A light emitting device having a structure;
A light emitting device comprising a semiconductor light emitting device emitting purple light (referred to as a purple LED chip) and a blue phosphor emitting blue light having a broad wavelength distribution excited by light from the semiconductor light emitting device (blue phosphor) LED lighting device, characterized in that it is described as an LED device.

Images