WO2019180959A1 - Light emitting device and lighting fixture - Google Patents

Abstract

The present invention is: a light emitting device, provided with a blue LED 10 with a peak wavelength in the vicinity of 460–480 nm, a red phosphor 21 that is disposed so as to cover the blue LED 10 and is excited by emitted light L_B of the blue LED 10 to emit red light L_R, a green phosphor 23 that is excited by the emitted light L_B of the blue LED 10 to emit green light L_G, and a sealing resin 30 to which a blue–green phosphor 25 that is excited by the emitted light L_B of the blue LED 10 to emit blue–green light L_BG is added, the light emitting device being configured such that, through use of the absorption characteristics of the blue–green phosphor 25, a blue light component in a short-wave-side blue region of the blue LED 10 is dimmed and a component extending from the nearest ultraviolet to the blue short-wavelength side is suppressed; and a lighting fixture using this light emitting device.

Description

Light emitting device and lighting apparatus

The present invention relates to a light emitting device that emits white light by exciting a phosphor with a blue LED (blue light emitting diode) and a lighting apparatus using the light emitting device.

In recent years, LED white illumination (LED lighting fixtures) using LEDs has become widespread. In this LED white illumination, there is a concern about the possibility of retinal damage due to blue light among the effects on the human body (so-called blue light problem).

Measures against this include the evaluation standard for the photobiological safety of lamps and lamp systems: IEC (International Electrotechnical Commission) / EN62471 standard GLS (general lighting service) classification standard. As an evaluation of the influence of blue light on retinal disorders, there is the IEC / TR62778 standard.

As a JIS (Japanese Industrial Standards) standard, JIS C7550 is set based on these standards. If the effective radiance: _Lb evaluation based on this is performed, the LED white illumination is positioned in the risk group 0 (risk exempt group), almost the same as other illumination light sources (such as fluorescent lamps and incandescent lamps). This group is defined by “effective radiance (value): L _b <10 ² (W · m ⁻² · sr ⁻¹ )”.

According to L _b evaluated in our LED white lighting, in straight tube type and base light type lighting fixture, a light source luminance (value) L _b became about 7-20. L _b evaluation because due brightness, large difference due to the shape (the concentration of intermediate light) luminaire, as a whole, a low color temperature, the direction of high color rendering properties of the luminaire, the luminance value L _b is more Low value.

Even in this risk group 0, there is essentially a movement to eliminate the short-wave blue side of blue light as much as possible. In particular, in areas where people with thin iris pupils live (such as Europe and the United States) and the eyes of children who are considered to have high transmittance of short-wave blue light, more gentle LED white illumination with less burden is required.

The device is roughly divided into three as shown below.

The first is a method of cutting the peak wavelength of blue light by about 20 to 30% using a filter, a light diffuser (scattering agent), a light reducing agent, or the like (see, for example, Patent Document 1). Therefore, it does not mean that the short-wave blue side component is reduced.

The second is a method of eliminating the projection of the spectrum in the blue region by using a relatively flat spectrum (spectral distribution) such as sunlight.

The second method results in a luminaire having an extremely high color rendering index. Specifically, LED white illumination is obtained by adopting a phosphor having a waveform that is relatively broad in blue light when excited by a near-ultraviolet or violet LED and approximated to a sunlight spectral distribution. Or there exists LED white illumination etc. which suppressed protrusion of the peak wavelength of blue light by using blue LED from which a plurality of wavelengths differ. However, the effect here is about the same as the first effect, which cuts the peak wavelength portion of blue light by about 20 to 30%.

A third method uses a blue LED having a relatively long wavelength. Specifically, by employing a blue LED of 470nm or longer wavelength, it is possible to reduce to about one order of magnitude the luminance value L _b. Although more essential than the first and second methods, the longer the blue LED is, the wider the spectrum width derived from the crystal structure, resulting in a gradual decrease in the short wave component, and The color rendering is significantly reduced.

WO2015 / 046222

In the first place, the effect of chemical change due to light is stronger as the wave becomes shorter, and the degree of action increases exponentially in the high energy direction (short wave direction).

Here, the concern about retinal damage caused by blue light is that shorter-wave ultraviolet light, near ultraviolet light, and violet light are absorbed by the cornea and the lens before reaching the retina of the eye and are difficult to reach. It is derived from the fact that the first short wave among the light reaching the retina is blue light.

The absorption degree of near-ultraviolet light and violet light in the lens has individual differences and also varies depending on the age. In particular, as the age is younger, the transmittance is higher as it is younger, and in terms of spectral distribution, the proportion of purple light to shortwave blue light reaching the retina increases from childhood to boyhood. Therefore, when considering the safe environment for children, white light is desired that is not limited to safety evaluation standards, but has reduced near-ultraviolet to short-wave blue light as much as possible.

The present invention provides a light emitting device and a luminaire capable of dimming the blue light component in the short-wave side blue region of a blue LED and capable of emitting white light in which near-ultraviolet to short-wave blue light is reduced as much as possible. Objective.

According to one aspect of the invention,
A blue LED having a peak wavelength between 460 and 480 nm;
Arranged over the blue LED,
A red phosphor that emits red light when excited by the emitted light of the blue LED;
A green phosphor that emits green light when excited by the emitted light of the blue LED;
A sealing resin to which a blue-green phosphor that is excited by the emitted light of the blue LED and emits blue-green light having an excitation spectrum peak in the near ultraviolet region is added, and
The blue-green phosphor is provided with a light-emitting device having a characteristic of absorbing a light component in a short-wave side blue region of the blue LED.

According to another aspect of the present invention, the light emitting device according to any one of claims 1 to 5 is further provided, wherein a blending ratio of the blue-green phosphor to the total phosphor is 60% or more. A luminaire for a photolithography chamber using an exposure wavelength smaller than the g-line is provided.

ADVANTAGE OF THE INVENTION According to this invention, the blue light component of the blue wavelength side blue region of blue LED can be reduced, and the light-emitting device and lighting fixture which can light-emit white light which reduced near ultraviolet light-short wave blue light as much as possible can be provided. .

FIG. 1 is a cross-sectional view schematically showing a configuration example of a light emitting device according to an embodiment of the present invention. FIG. 2 is a graph shown for explaining the characteristics of the light emitting device. FIG. 3 is a table showing a comparison of the characteristics of each light emitting device, taking as an example a case where blue-green phosphors are added in the mixing ratios of conditions I to III. FIG. 4 is a graph showing, in comparison with each spectrum of the light emitting device, an example in which a blue-green phosphor is added at a compounding ratio of Condition II. FIG. 5 is a graph showing, in comparison with each spectrum of the light emitting device, an example in which a blue-green phosphor is added at a compounding ratio of Condition III. FIG. 6 is a graph showing the relationship between the color rendering property Ra and the blue light component in the near ultraviolet to short wave side blue region of 450 nm or less. FIG. 7 is a graph showing the relationship of the blending ratio of the blue-green phosphor to all phosphors including other phosphors with respect to the blue light component in the near ultraviolet to short-wave side blue region of 450 nm or less. FIG. 8 (a) is a graph showing the characteristics of each light emitting device in comparison with an example in which a blue-green phosphor is added at a blending ratio of conditions I to III, and FIG. 8 (b) is a graph showing FIG. it is a graph showing an enlarged region W _M of (a). FIG. 9 is a table showing characteristics of each color temperature in comparison with an example of a lighting fixture to which the light emitting device according to the embodiment of the present invention is applied. FIG. 10 is a graph showing the spectral characteristics of each color temperature in a lighting fixture to which the light emitting device according to the embodiment of the present invention is applied. FIG. 11 is a graph showing an example of spectral sensitivity distribution characteristics of an i-line resist.

Next, an embodiment of the present invention will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals. Further, the embodiments described below exemplify apparatuses and methods for embodying the technical idea of the present invention, and the technical idea of the present invention includes the shape, structure, arrangement, etc. of components. It is not specific to the following. The embodiment of the present invention can be variously modified within the scope of the claims.

(Embodiment)
The light emitting device 1 according to the embodiment of the present invention, as shown in FIG. 1 includes a blue LED 10 that emits blue light L _B, and a sealing resin 30 disposed over the blue LED 10. The sealing resin 30 has a green phosphor 23 which is excited to emit light of blue LED 10 (blue light _{L B)} for emitting a green light _{L G} (green-yellow phosphor) is excited to emit light of blue LED 10 containing a red phosphor 21 that emits red light L _R. The sealing resin 30 is added with a blue-green phosphor 25 that is excited by the light emitted from the blue LED 10 and emits blue-green light _LBG .

Emitting device 1 shown in FIG. 1, for example, the recess bottom surface of the package 50 having a narrow recess 50R of the bottom _{50 RB} than the opening _{50 RS,} a structure in which blue LED10 are arranged. The recess 50 </ b> R of the package 50 is filled with the sealing resin 30. A silicone resin or the like can be used for the sealing resin 30.

Blue LED10, for example, having a peak wavelength λp around 460 ~ 480 nm, the entire wavelength band region emits blue light _{L B} of about 400 ~ 500 nm. When the peak wavelength of the blue LED 10 is less than 460 nm, wavelength attenuation in a desired short wavelength region becomes difficult. On the other hand, if it exceeds 480 nm, it is difficult to obtain a color rendering property (Ra = 80 or so) that can withstand general illumination, while it is easy to obtain wavelength attenuation. For this reason, the peak wavelength of the blue LED 10 is preferably in the range of 460 to 480 nm.

As the red phosphor 21, a material similar to (Sr, Ca) AlSiN ₃ : Eu, CaAlSiN ₃ : Eu, or Cax (Si, Al) ₁₂ (O, N) ₁₆ : Eu can be adopted.

The green phosphor 23 is made of Lu ₃ Al ₅₁₂ : Ce, (Ba, Sr) Si ₂ O ₂ N ₂ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu, CaSc ₂ O ₄ : Ce, or , (Ba, Sr, Ca) ₂ SiO ₄ : Eu or the like can be employed.

However, it is particularly preferable to use a Eu-activated phosphor from the viewpoint of enhancing color rendering.

As typical blue-green phosphors 25, for example, (Ca, Sr) ₅ (PO ₄ ) ₃ Cl: Eu, Sr ₃ MgSi ₂ O ₈ : Eu, Sr ₂ P ₂ O ₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, (Sr, Ba) Si ₉ Al ₁₉ ON ₃₁ : Eu, LaAl (Si, Al) ₆ N ₉ O: Ce, Sr ₄ Al ₁₄ O ₂₅ : Eu, BaSi ₂ O ₂ N ₂ : Eu, Ca ₈ A material similar to MgSi ₄ O ₁₆ C ₁₂ : Eu or Lu ₃ (Ga, Al) ₅ O ₁₂ : Ce can be employed.

As will be described later in detail, the light-emitting device 1 according to the present embodiment uses the absorption characteristics (dimming action) of the blue-green phosphor 25 to reduce the blue light component in the short wavelength side blue region of the blue spectrum of the blue LED 10. It is configured to be dimmed. That is, blue-green phosphor 25 mainly rather than being utilized as an emitter, the absorption spectral distribution (≒ excitation spectrum), utilized to consume the blue light L _B of the short side blue region (absorption) Is done. Thus, from the light emitting device 1, the red light _{L R} and is a green light _{L G} and the blue light _{L B} and a blue-green light _{L BG} is synthesized, for example, white light _{L W} without the following blue light component 450nm Is emitted. Therefore, according to the light emitting device 1 according to this embodiment, as output light, white light L _W with reduced as much as possible near-ultraviolet rays to short-wave blue light which is not good for eyes can be emitted.

The operation principle will be described in detail below.

FIG. 2 is a graph shown for explaining the characteristics of the light emitting device 1. Here shows in comparison of the emission spectra _{L S} of the blue spectrum _{L BS} and blue-green phosphor 25 of the excitation spectrum _{E S} and blue LED10 blue green phosphor 25, the normalized data.

As is apparent from this figure, the blue light component of the short-wave blue region of the blue LED 10, in particular, the blue spectrum L _BS in the following areas 450nm is excitation spectrum of the blue-green phosphor 25 having a peak in the near ultraviolet region E It is consumed by _S (≈absorption characteristic). Thus, the lens of the eye to reach the retina tends blue light L _B not be absorbed, it is possible to only dimming possible.

FIG. 3 shows a comparison of simulation results for the characteristics of the light-emitting device 1.

Here, a case will be described in which the color temperature is fixed at 5000 K and the blue-green phosphor 25 is added at a blending ratio of Condition I, Condition II, and Condition III. In FIG. 3, the blending ratio of the blue-green phosphor 25 is an arbitrary value whose numerical value varies depending on the type and quantity of the other phosphors 21 and 23.

Condition II is an example in which the blending ratio of the blue-green phosphor 25 to the other phosphors 21 and 23 is “0.4”. Condition III is an example in which the blending ratio of the blue-green phosphor 25 is set to “0.6”. Condition I is an example in which the blending ratio of the blue-green phosphor 25 is set to “0 (no addition)” so that a color rendering property (average color rendering index) Ra of 90 or more can be secured.

In producing the light emitting device 1 under the condition II, as shown in FIG. 4, the short wavelength side of the relatively long wavelength blue LED 10 (for example, peak wavelength λp = 466 nm) is utilized by utilizing the absorption characteristics of the blue-green phosphor 25. Only the light component in the blue region is absorbed. As a result, the blue light component in the near ultraviolet to short wave side blue region of 450 nm or less could be suppressed to 4.2% of the entire blue region (400 nm to 500 nm).

In addition, in the case of Condition II, as shown in FIG. 3, the color rendering property Ra is 80 or more (about 83.1), and it is not inferior as a general daylight color lighting fixture.

In the case of Condition III, as shown in FIG. 5, the blue light component in the near ultraviolet to short-wave side blue region of 450 nm or less can be reduced to 0% (see FIG. 3).

However, in the case of Condition III, the color rendering property Ra decreases to around 60 as shown in FIG.

FIG. 6 shows the relationship between the color rendering property Ra and the blue light component in the near ultraviolet to short wave side blue region of 450 nm or less. Here, in order to reduce the effective radiance (value) _Lb to about 1, the blue light component in the near ultraviolet to short-wave side blue region of 450 nm or less needs to be 5% or less. Because about one to L _b is 1/100 the value of the maximum limit value of the JIS (Japanese Industrial Standards) Risk Group 0 (Risk exempt groups) of _{L b} evaluation based on standards. On the other hand, in order to realize a color rendering property (Ra = 80 or so) similar to that of general illumination, it is necessary to make the blue light component in the near ultraviolet to short-wave side blue region of 450 nm or less 3% or more.

Next, FIG. 7 shows the relationship of the blending ratio of the blue-green phosphor to all phosphors including other phosphors with respect to the blue light component in the near ultraviolet to short-wave side blue region of 450 nm or less. According to this, in order to set the blue light component in the near-ultraviolet to shortwave side blue region of 450 nm or less shown in FIG. 6 to 3 to 5%, the blending ratio of the blue-green phosphor is 0.35 (35%) to It is preferable to set it as 0.45 (45%).

FIG. 8A shows the characteristics of each light emitting device 1 in comparison with the case where the blue-green phosphor 25 is added at the mixing ratio of Condition I, Condition II, and Condition III. ) is an enlarged view of a region _{W M} in FIG. 8 (a). However, the case where the peak wavelength λp of the blue LED 10 is 467 nm is illustrated.

As is clear from FIGS. 8A and 8B, the light emitting device 1 is configured such that the blue-green phosphor 25 is changed by the long wave shift by setting the blending ratio of the blue-green phosphor 25 to Condition II. Although the color rendering property Ra is reduced to about 80 as compared with the condition I where no addition is made, the blue light component in the near ultraviolet to short wave side blue region of 450 nm or less is suppressed to 4.2% of the entire blue region (400 nm to 500 nm). I was able to.

In addition, by setting the condition III, the color rendering property Ra is reduced to about 60, but the blue light component in the near ultraviolet to short wave side blue region of 450 nm or less can be reduced to 0%.

The light-emitting device 1 according to the present embodiment uses the absorption characteristics of the blue-green phosphor 25 to reduce the blue light components in the near-ultraviolet, violet, and short-wave side blue regions as much as possible, and in the white light _LW . it is obtained by so as to reduce the following blue light _{L B} 450 nm. That is, in the LED white illumination, the blue-green phosphor 25 is provided as a light reducing agent for the light component in the short-wave side blue region of 450 nm or less.

(Application example)
Next, an application example of this embodiment will be described.

Here, a case where the light emitting device according to the embodiment of the present invention is applied to, for example, a lighting apparatus (LED lighting apparatus) in a photolithography room in a semiconductor manufacturing factory will be described as an example.

Before explaining application examples, a brief description will be given of lighting equipment in a photolithography room in a semiconductor manufacturing factory.

In general, a luminaire in a photolithography room in a semiconductor manufacturing factory uses a yellow lamp in which output light of 500 nm or less is cut so that a resist agent to be used is not exposed. However, from the viewpoint of work environment and visibility, there is a demand that it can be replaced with white light. The g-line resist whose spectral sensitivity distribution extends to around 480 nm can be handled only by the above-mentioned yellow lamp, but in the case of an i-line h-line resist, the long wavelength side spectral sensitivity distribution is as shown in FIG. Therefore, it is possible to realize a white lamp using a blue light component on a relatively long wavelength side.

Therefore, a lighting apparatus (not shown) in the photolithography room is configured by using the light emitting device 1 according to this embodiment shown in FIG. In particular, in the luminaire to which the present embodiment is applied, the i-line and h-line resist agent is exposed by using the light-emitting device 1 to which the blue-green phosphor 25 is added in the mixing ratio of the condition III shown in FIG. I will not let you. That is, white illumination for a photolithography room using an exposure wavelength smaller than the g-line can be realized.

FIG. 9 and FIG. 10 show the characteristics when the color temperature of the light emitting device 1 is varied in the lighting fixture to which the light emitting device 1 according to the present embodiment is applied. Here, the case where the blue-green phosphor 25 is added at the same mixing ratio as in the condition III shown in FIG. 3 regardless of the color temperature is illustrated. In FIG. 9, the blending ratio of the blue-green phosphor 25 is an arbitrary value whose numerical value varies depending on the type and quantity of the other phosphors 21 and 23.

In the lighting fixture of the application example, the characteristics when the color temperature is 5000K are the same as those in the condition III of the light emitting device 1 shown in FIG. Specifically, by setting the blending ratio of the blue-green phosphor 25 to “0.6”, as shown in FIGS. 9 and 10, the blue color in the near ultraviolet to short wave side blue region of 450 nm or less from the lighting fixture is obtained. The light component can be 0%. In this case, the color rendering property Ra was 59.4.

Further, when the color temperature is 4000 K, as shown in FIGS. 9 and 10, by setting the blending ratio of the blue-green phosphor 25 to “0.600”, the near-ultraviolet light of 450 nm or less from the luminaire is obtained. The blue light component in the blue region on the short wave side can be set to 0%. In this case, the color rendering property Ra was 59.9.

Further, when the color temperature is 3000 K, as shown in FIGS. 9 and 10, the blending ratio of the blue-green phosphor 25 is set to “0.600”, so that the near-ultraviolet light of 450 nm or less from the luminaire is obtained. The blue light component in the blue region on the short wave side can be set to 0%. In this case, the color rendering property Ra was 63.4.

As described above, when the light-emitting device 1 according to this embodiment is applied as a lighting apparatus for a photolithography room, the blending ratio of the blue-green phosphor 25 regardless of the color temperature (5000K, 4000K, 3000K). By making the condition III, the blue light component of 450 nm or less from the luminaire can be made completely zero. Thus, even at the case where the illumination for photolithography chamber to a white light L _W, sensitive at g-line is less than the exposure wavelength, as long as, for example, i-ray h-ray resist material, avoid being sensitive It becomes possible.

FIG. 11 exemplifies spectral sensitivity characteristics of i-line resist. For example, g-line, h-line, i-line and resist agent of a monochromatic mercury exposure light source (high-pressure mercury lamp) (not shown) Shows the relationship.

To expose the resist agent in the photolithography room, for example, g-line (436 nm), h-line (405 nm), i-line (365 nm), or broad (g, h, i-line) from a high-pressure mercury lamp. ) Is used. When the g-line is used, since a resist agent having sensitivity in a longer wavelength band than that of the resist agent shown in FIG. 11 is used, safe illumination light having no blue light component of 480 nm or less is necessary, and rather yellow Can only be handled with lights.

That is, the light emitting device 1 according to this embodiment, in the case of applying to the lighting fixtures of the white light L _W for photolithography chamber using the g-line is less than the exposure wavelength, ensuring that the resist material is sensitive Can be prevented. In addition, it is possible to obtain white illumination that is easy on the eyes and has excellent visibility and can sufficiently withstand long stays.

As a light source device that can prevent exposure of an ultraviolet-sensitive irradiated object, a light source device that can freely select a wavelength according to the purpose (Reference 1: JP-A-2017-022137) has already been proposed. . In the case of this light source device, although there is an advantage that the selectivity is high and energy loss is small, the configuration is complicated and the cost is high compared to the lighting fixture to which the light emitting device 1 according to the present embodiment is applied. is there. There are also concerns such as variations in the wavelength of each LED and uncertainty of the wavelength on the short wave region side.

In addition, there has already been proposed a lighting apparatus (Reference 2: JP-A-2017-204348) that can cut off light of a specific wavelength that reacts with the photosensitive material from the illumination light source in the process of using the photosensitive material. In this luminaire, the illumination light source is covered with an ultraviolet absorbing member to cut off light of a specific wavelength. There are concerns about variations in the light-absorbing agent having spectral characteristics of proper absorption.

As described above, the light emitting device 1 according to this embodiment, in the case of applying as a lighting fixture of the white light L _W for photolithography chamber using a resist for i-line, by blue-green phosphor 25, an ultraviolet light, Purple light and blue light on the short wave side can be reliably cut. Thus, without any concern as references 1 and 2, the white light L _W without the following blue light components 450 nm, it is possible illumination photolithography chamber. Therefore, as a lighting apparatus for a photolithography room, it is possible to provide highly reliable LED white illumination that has excellent visibility, can sufficiently withstand a long stay, has little burden on the eyes, and is extremely reliable. it can.

In the present embodiment, the case where the blue light component of 450 nm or less is set to zero is exemplified, but the present invention is not limited to this, and if the color temperature is lowered or a longer wavelength blue LED is used, 460 nm or less. The blue light component of is also reduced. Therefore, for example, a light-emitting device capable of setting a blue light component of 460 nm or less to zero can be applied to a luminaire in a photolithography room using a g-line resist.

(Other embodiments)
As mentioned above, although this invention was described by embodiment, it should not be understood that the description and drawing which form a part of this indication limit this invention. From this disclosure, various alternative embodiments, examples and operational techniques will be apparent to those skilled in the art.

As described above, the present invention naturally includes various embodiments that are not described herein. Therefore, the technical scope of the present invention is defined only by the invention specifying matters according to the scope of claims reasonable from the above description.

The light-emitting device of the present invention and a lighting fixture using the light-emitting device can be used for various uses of a light-emitting device and a lighting fixture that excite a phosphor with a blue LED to output white light.

Claims (8)

A blue LED having a peak wavelength between 460 and 480 nm;
Arranged over the blue LED,
A red phosphor that emits red light when excited by the emitted light of the blue LED;
A green phosphor that emits green light when excited by the emitted light of the blue LED;
A sealing resin to which a blue-green phosphor that is excited by the emitted light of the blue LED and emits blue-green light having an excitation spectrum peak in the near ultraviolet region is added, and
The light-emitting device according to claim 1, wherein the blue-green phosphor has a characteristic of absorbing a light component in a short-wave side blue region of the blue LED. The light-emitting device according to claim 1, wherein the blue-green phosphor has a characteristic of absorbing only a light component of 500 nm or less. The blue-green phosphor includes (Ca, Sr) ₅ (PO ₄ ) ₃ Cl: Eu, Sr ₃ MgSi ₂ O ₈ : Eu, Sr ₂ P ₂ O ₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, (Sr, _{Ba) Si 9 Al 19 ON 31} : Eu, LaAl (Si, Al) 6 N 9 O: Ce, Sr 4 Al 14 O 25: Eu, BaSi 2 O 2 N 2: Eu, Ca 8 MgSi 4 O 16 C 12 The light-emitting device according to claim 1, wherein the light-emitting device is at least one of: Eu and Lu ₃ (Ga, Al) ₅ O ₁₂ : Ce. 4. The light emitting device according to claim 1, wherein a blue light component having a wavelength of 450 nm or less in the short wave side blue region is 5% or less of the entire blue region. The light emitting device according to any one of claims 1 to 4, wherein a blending ratio of the blue-green phosphor to all phosphors is set to 35% or more. 6. The light emitting device according to claim 5, wherein a blending ratio of the blue-green phosphor to the total phosphor is set to 35% to 45%. The light emitting device according to any one of claims 1 to 5, wherein a blue light component of 450 nm or less in the short wave side blue region is 0% of the entire blue region. Furthermore, the exposure wavelength smaller than g line | wire provided with the light-emitting device of any one of Claim 1 thru | or 5 which made the compounding ratio with respect to all the fluorescent substances of the said blue-green fluorescent substance 60% or more is used. Lighting equipment for photolithography room.

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