JP5566822B2 - LED bulb - Google Patents

Description

  Embodiments of the present invention relate to LED bulbs.

  Light emitting devices using light emitting diodes (LEDs) are widely used in lighting devices such as backlights for liquid crystal display devices, signal devices, various switches, in-vehicle lamps, and general lighting. In particular, white light emitting LED lamps that combine LEDs and phosphors are attracting attention as an alternative to incandescent light bulbs, and their development is rapidly progressing. As a light bulb to which an LED lamp is applied (hereinafter referred to as an LED light bulb), for example, a globe is attached to a base portion provided with a bulb base, an LED chip is disposed in the globe, and an LED chip lighting circuit is further provided in the base portion. One having an integral lamp structure provided with a lamp is known.

  In a conventional LED bulb, a combination of a blue light emitting LED chip (blue LED) and a yellow phosphor (YAG phosphor, etc.) that absorbs blue light emitted from the blue LED and emits yellow light is applied. The white light is obtained by mixing the blue light emitted from the blue LED and the yellow light emitted from the yellow phosphor by absorbing the blue light. An LED bulb combining a blue LED and a yellow phosphor has a feature that it is easy to ensure brightness. However, white light based on a mixed color of blue light from a blue LED and yellow light from a yellow phosphor has a drawback that it is inferior in color rendering evaluated by an average color rendering index (Ra) or the like.

  LED bulbs that combine conventional blue LEDs and yellow phosphors have a light distribution that is biased toward the blue and yellow components, and the red component is insufficient. It has a drawback that the reflected light when viewed is different from the natural color seen under sunlight. In addition, in conventional LED bulbs, the light emitted from the blue LED is used to generate white light, so it is difficult to equalize the overall brightness of the bulb, which causes glare and local glare. It is difficult to reduce so-called glare.

JP-A-2005-005546 JP 2009-170114 A

  An object of the present invention is to provide an LED bulb that achieves improved color rendering properties and reduced glare.

The LED light bulb according to the embodiment includes an LED module, a base part on which the LED module is installed, and a globe attached to the base part so as to cover the LED module. The LED module includes an ultraviolet or purple LED chip mounted on a substrate. The base portion is provided with a lighting circuit for lighting the LED chip and a base electrically connected to the lighting circuit. On the inner wall surface of the glove, seen contains at least one kind of particles selected et or zinc oxide and cerium oxide beam, ultraviolet or violet light-absorbing layer is provided having a thickness of 600μm or less the range of 10 [mu] m. A fluorescent film is provided on the inner surface side of the globe through an ultraviolet or violet light absorbing layer. The fluorescent film is provided apart from the LED chip, and absorbs ultraviolet or purple light emitted from the LED chip to emit white light.

It is a figure which shows the LED light bulb by 1st Embodiment in a partial cross section. It is a figure which shows the LED light bulb by 2nd Embodiment. It is a figure which shows an example of the relationship between the average particle diameter of the component particle | grains of the ultraviolet or purple light absorption layer of the LED bulb in an Example, and a light beam.

  Hereinafter, an LED bulb according to an embodiment will be described with reference to the drawings. FIG. 1 is a partial cross-sectional view of the LED bulb according to the first embodiment. FIG. 2 is a view showing an LED bulb according to the second embodiment. The LED bulb 1 shown in these drawings includes an LED module 2, a base portion 3 on which the LED module 2 is installed, a globe 4 attached on the base portion 3 so as to cover the LED module 2, and the base portion 3. A base 6 attached to the lower end through an insulating member 5 and a lighting circuit (not shown) provided in the base 3 are provided.

  The LED module 2 includes an ultraviolet or purple LED chip 8 mounted on a substrate 7. A plurality of LED chips 8 are surface-mounted on the substrate 7. For the LED chip 8 emitting ultraviolet to purple light, a light emitting diode of InGaN, GaN, AlGaN or the like is used. A wiring network (not shown) is provided on the surface of the substrate 7 (and further inside if necessary), and the electrodes of the LED chip 8 are electrically connected to the wiring network of the substrate 7. A wiring (not shown) is drawn out on the side surface or bottom surface of the LED module 2, and this wiring is electrically connected to a lighting circuit (not shown) provided in the base portion 3. The LED chip 8 is lit by a DC voltage applied through a lighting circuit.

  A fluorescent film 10 is provided on the inner surface side of the globe 4 via an ultraviolet or violet light absorbing layer 9 containing at least one kind of particles selected from zinc oxide, cerium oxide, and titanium oxide. The ultraviolet to purple light absorbing layer 9 will be described later. The phosphor film 10 absorbs ultraviolet or violet light emitted from the LED chip 8 and emits white light. Unlike the LED module in which the phosphor particles are dispersed in the sealing resin of the LED chip, the phosphor film 10 emits white light. The LED chip 8 is provided so as to be separated from the LED chip 8. The electrical energy applied to the LED bulb 1 is converted into ultraviolet to violet light by the LED chip 8, and further converted into light having a longer wavelength by the fluorescent film 10 and emitted as white light. The white light emitted from the LED bulb 1 differs from the conventional LED bulb combining a blue LED and a yellow phosphor, and is substantially constituted only by the light emission of the fluorescent film 10.

  Since the LED bulb 1 emits the fluorescent film 10 provided on the entire inner surface of the globe 4, unlike the LED module in which the conventional phosphor particles are dispersed in the sealing resin, the entire fluorescent film 10 is surface emitting. The white light spreads from the fluorescent film 10 in all directions. In addition, unlike a conventional LED light bulb combining a blue LED and a yellow phosphor, white light is obtained only by light emission from the phosphor film 10, so that local luminance unevenness and the like can be suppressed. As a result, uniform and soft white light can be obtained without glare. That is, the glare of the LED bulb 1 can be greatly reduced as compared with a conventional LED bulb combining a blue LED and a yellow phosphor.

  The shape of the globe 4 is not particularly limited, and a dome shape as shown in FIG. 1 or a eggplant shape as shown in FIG. 2 can be applied. In FIG. 2, the illustration of the configuration inside the globe 4 is omitted, but the LED bulb 1 shown in FIG. 2 has the same configuration as the LED bulb 1 shown in FIG. 1 except that the shape of the globe 4 is different. Yes. The material for forming the globe 4 may be any material as long as it has translucency. For example, a globe 4 made of glass or resin is used. The globe 4 has a size equivalent to, for example, an incandescent bulb.

  The emission color of the LED bulb 1 is determined by the combination of the emission wavelength of the LED chip 8 and the phosphor constituting the phosphor film 10. In obtaining white light in combination with the UV to purple LED chip 8, the phosphor film 10 is composed of a mixed phosphor (BGR or BYR phosphor) including a blue phosphor, a green to yellow phosphor, and a red phosphor. It is preferable. The mixed phosphor may further include at least one phosphor selected from a blue-green phosphor and a deep red phosphor. Each phosphor constituting the mixed phosphor is not particularly limited, but the combination with ultraviolet to violet light from the LED chip 8 and the color temperature and color rendering properties (average color rendering index Ra, etc.) of the obtained white light From the viewpoint of ()), it is preferable to use the following phosphors.

As the blue phosphor, a phosphor having an emission peak wavelength in the range of 430 to 460 nm is used. For example, a europium (Eu) activated alkaline earth chlorophosphate phosphor having a composition represented by the formula (1) is used. It is preferable to use it.
General _{formula: (Sr 1-xyz Ba x} Ca y Eu z) 5 (PO 4) 3 · Cl ... (1)
(Wherein x, y and z are numbers satisfying 0 ≦ x <0.5, 0 ≦ y <0.1, 0.005 ≦ z <0.1)

As the green to yellow phosphor, a phosphor having an emission peak wavelength in the range of 490 to 580 nm is used. For example, europium (Eu) and manganese (Mn) activated alkaline earth having a composition represented by the formula (2) Aluminate phosphors, europium (Eu) and manganese (Mn) activated alkaline earth silicate phosphors having a composition represented by formula (3), europium having a composition represented by formula (4) It is preferable to use at least one selected from Eu) activated sialon phosphor and europium (Eu) activated sialon phosphor having the composition represented by formula (5).
General _{formula: (Ba 1-xyz Sr x} Ca y Eu z) (Mg 1-u Mn u) Al 10 O 17 ... (2)
(In the formula, x, y, z, and u satisfy 0 ≦ x <0.2, 0 ≦ y <0.1, 0.005 <z <0.5, and 0.1 <u <0.5. Is the number to do)
General _{formula: (Sr 1-xyzu Ba x} Mg y Eu z Mn u) 2 SiO 4 ... (3)
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. 0.02)
General formula: (Si, Al) ₆ (O, N) ₈ : Eu _x (4)
(Wherein x is a number satisfying 0 <x <0.3)
General formula: (Sr _1−x Eu _x ) _α Si _β Al _γ O _δ N _ω (5)
(Where x, α, β, γ, δ, and ω are 0 <x <1, 0 <α ≦ 3, 12 ≦ β ≦ 14, 2 ≦ γ ≦ 3.5, 1 ≦ δ ≦ 3, 20 ≦ ω ≦ 22)

As the red phosphor, a phosphor having an emission peak wavelength in the range of 580 to 630 nm is used. For example, a europium (Eu) activated lanthanum oxysulfide phosphor having a composition represented by formula (6), formula (7 And at least one selected from a europium (Eu) activated couun phosphor having a composition represented by formula (8) and a europium (Eu) activated sialon phosphor having a composition represented by formula (8): preferable.
The general _{formula: (La 1-xy Eu x} M y) 2 O 2 S ... (6)
(In the formula, M represents at least one element selected from Sm, Ga, Sb, and Sn, and x and y satisfy 0.08 ≦ x <0.16 and 0.000001 ≦ y <0.003. Is the number to do)
General formula: (Ca _1-xy Sr _x Eu _y ) SiAlN ₃ (7)
(Wherein x and y are numbers satisfying 0 ≦ x <0.4 and 0 <x <0.5)
General formula: (Sr _1−x Eu _x ) _α Si _β Al _γ O _δ N _ω (8)
(Where x, α, β, γ, δ, and ω are 0 <x <1, 0 <α ≦ 3, 5 ≦ β ≦ 9, 1 ≦ γ ≦ 5, 0.5 ≦ δ ≦ 2, 5 ≦ ω ≦ 15)

As the blue-green phosphor, a phosphor having an emission peak wavelength in the range of 460 to 490 nm is used. For example, europium (Eu) and manganese (Mn) activated alkaline earths having the composition represented by the formula (9) It is preferable to use a silicate phosphor.
General _{formula: (Ba 1-xyzu Sr x} Mg y Eu z Mn u) 2 SiO 4 ... (9)
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. 0.02)

As the deep red phosphor, a phosphor having an emission peak wavelength in the range of 630 to 780 nm is used. For example, a manganese (Mn) -activated magnesium fluorogermanate phosphor having a composition represented by the formula (10) is used. It is preferable to use it.
General formula: αMgO · βMgF ₂ · (Ge _1−x Mn _x ) O ₂ (10)
(In the formula, α, β, and x are numbers satisfying 3.0 ≦ α ≦ 4.0, 0.4 ≦ β ≦ 0.6, and 0.001 ≦ x ≦ 0.5)

  The ratio of the phosphors constituting the mixed phosphor is appropriately set according to the emission color of the LED bulb 1, etc., but the mixed phosphor is, for example, a blue color having a mass ratio of 10 to 60%. Phosphor, blue-green phosphor in the range of 0-10%, green to yellow phosphor in the range of 1-30%, red phosphor in the range of 30-90%, and deep red fluorescence in the range of 0-35% It preferably includes a body. According to such a mixed phosphor, a wide range of white light having a correlated color temperature of 6500K to 2500K can be obtained with the same fluorescent species. In the case of a combination of a conventional blue LED and a yellow phosphor, it is difficult to adjust the light bulb color of 2800K including the deviation with only a combination of two colors, and a red phosphor that emits light by blue excitation should be added. Is required.

  The phosphor film 10 is formed, for example, by mixing a mixed phosphor powder with a binder resin or the like, applying the mixture (for example, slurry) to the inner surface of the globe 4 and then heating and curing the mixture. The mixed phosphor powder preferably has an average particle diameter (median value of particle size distribution (D50)) in the range of 3 to 50 μm. By using the mixed phosphor (phosphor particles) having such an average particle diameter, the absorption efficiency of the ultraviolet to violet light emitted from the LED chip 8 by the phosphor film 10 can be increased. The luminance can be improved. The film thickness of the fluorescent film 10 is preferably in the range of 200 to 800 μm. If the thickness of the fluorescent film 10 is less than 200 μm, the brightness of white light may be insufficient, and if it exceeds 800 μm, the brightness of the LED bulb 1 may be reduced.

  When an LED chip 8 emitting ultraviolet to purple light is used as the excitation source of the LED bulb 1, unlike the conventional LED bulb combining a blue LED and a yellow phosphor, the fluorescent film 10 can be used in various ways as described above. It can be composed of a phosphor. That is, since the selection range of the phosphor species constituting the fluorescent film 10 is widened, the color rendering property of white light emitted from the LED bulb 1 can be enhanced. Specifically, white light having a correlated color temperature of 6500 K or less and an average color rendering index (Ra) of 85 or more can be obtained. By obtaining such white light, it is possible to improve the practicality of the LED bulb 1 as an alternative to the incandescent bulb.

  The LED chip 8 may be an ultraviolet or purple light emitting type LED (emission peak wavelength is 350 to 430 nm), and in particular, the emission peak wavelength is in the range of 370 to 410 nm and the half width of the emission spectrum is 10 to 15 nm. It is preferable to use the LED chip 8. A combination of the LED chip 8 and the phosphor film 10 composed of the above-described mixed phosphor (BGR or BYR phosphor, and a mixed phosphor added with a blue-green phosphor or a deep red phosphor as necessary). When used, stable white light can be obtained for the correlated color temperature (emission color) regardless of the output variation of the LED chip 8, and the yield of the LED bulb 1 can be increased. In the conventional combination of a blue LED and a yellow phosphor, the output variation of the LED chip directly affects the correlated color temperature (light emission color), and thus the yield of the LED bulb is likely to be reduced.

  The plurality of LED chips 8 surface-mounted on the substrate 7 are preferably covered with a transparent resin layer 11. That is, the LED module 2 preferably includes a plurality of LED chips 8 surface-mounted on the substrate 7 and a transparent resin layer 11 provided on the substrate 7 so as to cover the plurality of LED chips 8. For the transparent resin layer 11, for example, a silicone resin, an epoxy resin, or the like is used, and it is particularly preferable to use a silicone resin excellent in ultraviolet resistance. Thus, by covering the plurality of LED chips 8 with the transparent resin layer 11, the light emitted from each LED chip 8 propagates to each other, and the local light intensity that contributes to glare is alleviated. The light extraction efficiency can be increased.

  By the way, when the LED chip 8 of ultraviolet to purple light emission is used as the excitation source of the fluorescent film 10, it is important to suppress leakage of ultraviolet rays from the globe 4. The ultraviolet rays leaking from the globe 4 may adversely affect printed matter, food, medicine, human body, etc. existing in the vicinity of the LED bulb 1 or in the indoor space where the LED bulb 1 is disposed. Therefore, in the LED bulb 1 of this embodiment, the ultraviolet or purple light absorbing layer 9 is provided on the inner wall surface of the globe 4. The ultraviolet to violet light absorbing layer 9 is formed between the inner surface of the globe 4 and the fluorescent film 10. The ultraviolet to violet light absorbing layer 9 is a particle layer containing at least one kind of particles selected from zinc oxide, cerium oxide, and titanium oxide, whereby ultraviolet to violet light that has passed through the fluorescent film 10 is externally transmitted from the globe 4. It is possible to suppress leakage into the space.

  Since at least one kind of particles selected from zinc oxide, cerium oxide, and titanium oxide all transmit visible light and have an absorption peak in the ultraviolet to purple region, the ultraviolet to purple color that has passed through the fluorescent film 10. Light can be absorbed and leakage of ultraviolet or purple light from the globe 4 can be suppressed. All the particles absorb ultraviolet rays in bulk, but particularly zinc oxide has a strong ultraviolet-absorbing ability, so that leakage of ultraviolet to purple light from the globe 4 can be more effectively suppressed. The ultraviolet to violet light absorbing layer 9 preferably has a thickness in the range of 10 to 600 μm. If the thickness of the ultraviolet to violet light absorbing layer 9 is less than 10 μm, there is a possibility that the effect of absorbing ultraviolet to violet light may not be sufficiently obtained, and if it exceeds 600 μm, the luminance of white light emitted from the fluorescent film 10 May decrease.

  The particles (at least one particle selected from zinc oxide, cerium oxide, and titanium oxide) constituting the ultraviolet to violet light absorbing layer 9 preferably have an average particle size of 0.1 μm or less. By constituting the ultraviolet to violet light absorbing layer 9 with particles having such an average particle diameter, scattering of white light emitted from the fluorescent film 10 is suppressed. Accordingly, it is possible to suppress a decrease in the light emission efficiency of the LED bulb 1. When the average particle diameter of the particles constituting the ultraviolet to violet light absorbing layer 9 exceeds 0.1 μm, the scattering of white light emitted from the fluorescent film 10 increases, and the luminous efficiency of the LED bulb 1 is likely to decrease. . That is, by constituting the ultraviolet to violet light absorbing layer 9 with particles having an average particle diameter of 0.1 μm or less, it is possible to provide the LED bulb 1 having excellent luminous efficiency while suppressing leakage of ultraviolet rays from the globe 4. It becomes possible.

  The LED bulb 1 of this embodiment has an ultraviolet to purple light absorbing layer 9 as described above, for example, the amount of leakage of ultraviolet to purple light from the globe 4 (the amount of energy of leaking ultraviolet light) is 0.03 mW / nm / lm (lumens). Less than. If the amount of leakage of ultraviolet rays is such, the color of printed matter existing in the vicinity of the LED bulb 1 or in the indoor space in which the LED bulb 1 is disposed, etc. Deterioration, deterioration of food and chemicals, adverse effects on the human body and the like can be suppressed as much as possible, and the practicality of the LED bulb 1 can be enhanced. Moreover, regarding the luminous efficiency of the LED bulb 1, for example, 40 lm / W or more can be realized. Here, the leakage amount of ultraviolet to purple light is the peak value (unit: mW / nm) of ultraviolet to purple light emission in the range of 370 to 415 nm in the emission spectrum of the LED bulb 1, and the luminous flux (unit: lm) of the LED bulb 1. ) Is the value divided by.

  The LED bulb 1 of this embodiment is manufactured as follows, for example. First, a slurry containing the constituent particles of the ultraviolet to violet light absorbing layer 9 is prepared. The particle slurry is prepared by mixing at least one powder selected from, for example, zinc oxide, cerium oxide, and titanium oxide with a binder resin such as a silicone resin, an epoxy resin, or a urethane resin. In addition, a phosphor slurry containing the phosphor powder is prepared. The phosphor slurry is prepared, for example, by mixing phosphor powder with a binder resin such as silicone resin, epoxy resin, or urethane resin, and filler such as alumina or silica. The mixing ratio of the phosphor and the binder resin is appropriately selected depending on the type and particle size of the phosphor. For example, the binder resin amount is in the range of 1 to 30% by mass with respect to the total amount of the phosphor and the binder resin. It is preferable that It is preferable to appropriately set the type, average particle size, mixing ratio, etc. of the phosphor from the above-described condition range according to the target white light.

  Next, a particle slurry and a phosphor slurry are sequentially applied to the inner surface of the globe 4. The slurry is applied by, for example, a spray method, a dip method, a method of rotating the globe 4, or the like, and uniformly applied to the inner surface of the globe 4. Next, the laminated film of the particle slurry coating film and the phosphor slurry coating film is heated and dried using a heating device such as a dryer or an oven, so that the ultraviolet or purple light absorbing layer 9 is formed on the inner surface side of the globe 4. The phosphor film 10 is formed. The film thickness of the ultraviolet to violet light absorbing layer 9 and the fluorescent film 10 can be adjusted by the solid content, binder viscosity, curing temperature, time, etc. in each slurry. Thereafter, the target LED bulb 1 is manufactured by attaching the globe 4 having the ultraviolet to purple light absorbing layer 9 and the fluorescent film 10 to the base portion 3 on which the LED module 2 and the base 6 are installed.

  Next, specific examples and evaluation results thereof will be described.

Example 1
Eu-activated alkaline earth chlorophosphate ((Sr _0.604 Ba _0.394 Eu _0.002 ) ₅ (PO ₄ ) ₃ Cl) phosphor having an average particle size of 40 μm as a blue phosphor and an average particle size of green to yellow phosphors 17μm of Eu and Mn-activated alkaline earth silicate _{((Sr 0.675 Ba 0.25 Mg 0.0235} Eu 0.05 Mn 0.0015) 2 SiO 4) phosphor and, having an average particle size of 45μm as a red phosphor Eu-activated lanthanum oxysulfide ( (La _0.9 Eu _0.1 ) ₂ O ₂ S) phosphor was prepared.

The above-mentioned blue phosphor, green to yellow phosphor and red phosphor are mixed in a mass ratio of 18.8%, 4.4%, 76.8% so that the color temperature of white light is 3000K. Thus, a mixed phosphor was prepared. Further, cerium oxide (CeO ₂ ) powder having an average particle diameter of 38 nm was prepared as particles constituting the ultraviolet to violet light absorbing layer. Using these mixed phosphors and cerium oxide powder, an LED bulb was produced as follows. First, a cerium oxide powder was dispersed in a silicone resin as a binder resin to prepare a particle slurry. Similarly, the phosphor mixture was dispersed in a silicone resin as a binder resin to prepare a phosphor slurry.

  Next, an amount of particle slurry having a desired film thickness was introduced into the globe, and the globe was rotated while changing the angle so as to spread uniformly on the inner surface of the globe. Using an infrared heater or a dryer, heating was performed until the particle slurry began to harden and the coating film did not flow. Next, an amount of phosphor slurry having a desired film thickness was introduced into the globe, and the globe was rotated while changing the angle in the same manner. Similarly, heating was performed until the phosphor slurry began to harden and the coating film did not flow. Thereafter, heat treatment was performed using an oven or the like under conditions of about 100 ° C. × 5 hours to completely cure the particle slurry coating film and the phosphor slurry coating film.

  The particle layer thus formed (ultraviolet to violet light absorbing layer) had a thickness of 10 μm, and the solid content (particle amount) in the particle layer was about 30% by mass. The thickness of the fluorescent film was 540 μm. In addition, the LED module uses 126 LED chips whose emission peak wavelength is 400 nm and the emission spectrum half-value width is 15 nm, these LED chips are surface-mounted on a substrate, and further covered with silicone resin. did. A glove having a dome shape made of polycarbonate was used. The thickness of the globe is about 1 mm. The LED bulb assembled using these components was subjected to the characteristic evaluation described later.

(Examples 2 to 8)
An LED bulb was assembled in the same manner as in Example 1 except that the film thickness of the particle layer (ultraviolet to violet light absorbing layer) was changed to the thickness shown in Table 1. These LED bulbs were subjected to the characteristic evaluation described later.

(Comparative Example 1)
An LED bulb was assembled in the same manner as in Example 1 except that the phosphor layer was formed directly on the inner surface of the globe without forming the particle layer (ultraviolet to violet light absorbing layer). This LED bulb was subjected to the characteristic evaluation described later.

(Comparative Example 2)
An LED bulb to which a combination of a blue light emitting LED chip and a yellow phosphor (YAG phosphor) was applied was prepared, and this was subjected to characteristic evaluation described later. A fluorescent film made of a yellow phosphor is applied immediately above a blue LED chip, and these constitute an LED bulb.

  Next, the LED bulbs of Examples 1 to 8 and Comparative Examples 1 to 2 are lit in an environment of 25 ° C. (power consumption: 8.7 W), and the luminous flux of white light emitted from each LED bulb and the luminous efficiency Correlated color temperature and average color rendering index Ra were measured. These characteristics were measured by a SLMS total luminous flux measurement system manufactured by Loves Fair. Further, the leakage amount of ultraviolet or purple light when each LED bulb was turned on was measured. The amount of leakage of ultraviolet to purple light is the peak value (unit: mW / nm) of ultraviolet to purple light emission in the range of 370 nm to 415 nm in the spectrum measured by the above measurement system, and the luminous flux of the LED bulb (unit: lm). (Unit: mW / nm / lm). These measurement / evaluation results are shown in Table 1.

  As is clear from Table 1, it can be seen that the LED bulbs according to Examples 1 to 8 have a small amount of leakage of ultraviolet rays and a practical brightness. If the thickness of the ultraviolet or violet light absorbing layer exceeds 600 μm, the luminous efficiency is less than 40 lm / W, and therefore the practicality of the LED bulb is slightly lowered. For this reason, the thickness of the ultraviolet or violet light absorbing layer is preferably 600 μm or less. In addition, the LED bulbs according to Examples 1 to 8 are excellent in the average color rendering index Ra as compared with the LED bulb of Comparative Example 2. Furthermore, when the glare and local glare (glare) at the time of lighting of each LED bulb were visually evaluated, the LED bulbs according to Examples 1 to 8 had less glare than the LED bulb according to Comparative Example 2. It was confirmed that From these facts, it can be seen that the LED bulbs according to Examples 1 to 8 are excellent in practicality as substitutes for incandescent bulbs.

(Examples 9 to 12)
As in the case of Example 1 except that zinc oxide (ZnO) powder having an average particle diameter shown in Table 2 is used as the constituent particles of the ultraviolet to violet light absorbing layer, and the film thickness of the ultraviolet to violet light absorbing layer is 500 μm. I assembled an LED bulb. The characteristics of these LED bulbs were measured and evaluated in the same manner as in Example 1. Table 2 shows the measurement and evaluation results. FIG. 3 shows the relationship between the average particle diameter of the constituent particles of the ultraviolet to violet light absorbing layer and the luminous flux of the LED bulb.

  As is apparent from Table 2 and FIG. 3, when the average particle diameter of the constituent particles of the ultraviolet to violet light absorbing layer exceeds 100 nm, the light flux of the LED bulb is significantly reduced. For this reason, in order to obtain a practical LED light bulb, the average particle diameter of the constituent particles of the ultraviolet to violet light absorbing layer is preferably 100 nm or less. In addition, the leakage amount of the ultraviolet rays of the LED bulbs according to Examples 9 to 12 was all zero. Moreover, it was confirmed that all the light emission from the LED bulbs according to Examples 9 to 12 was excellent in color rendering and further reduced in glare.

(Example 13)
In addition to the blue phosphor, the green to yellow phosphor and the red phosphor similar to those in Example 1, Eu and Mn activated alkaline earth silicate ((μ) having an average particle size of 20 μm as a blue-green (BG) phosphor (( Sr _0.225 Ba _0.65 Mg _0.0235 Eu _0.1 Mn _0.0015 ) ₂ SiO ₄ ) phosphor and Mn-activated magnesium fluorogermanate (3.5 MgO · 0.5 MgF ₂ as a deep red (DR) phosphor having an average particle size of 12 μm) A (Ge _0.75 Mn _0.25 ) O ₂ ) phosphor was prepared.

The above-described blue phosphor, blue-green phosphor, green to yellow phosphor, red phosphor, and deep red phosphor are combined so that the color temperature of white light becomes 2800 K, 26.0%, 0.5%, Mixed phosphors were prepared by mixing at a mass ratio of 3.7%, 64.5%, and 5.3%. Further, titanium oxide (TiO ₂ ) powder having an average particle diameter of 40 nm was prepared as particles constituting the ultraviolet to violet light absorbing layer. Using these mixed phosphors and titanium oxide powder, an LED bulb was produced in the same manner as in Example 1. The film thickness of the ultraviolet to violet light absorbing layer was 600 μm, and the solid content (particle amount) in the particle layer was 1% by mass. The characteristics of this LED bulb were measured and evaluated in the same manner as in Example 1. These measurement / evaluation results are shown in Table 3.

(Examples 14 to 15)
An LED bulb was assembled in the same manner as in Example 13 except that the solid content (particle amount) and film thickness in the ultraviolet to purple light absorbing layer were changed to the values shown in Table 3. The characteristics of these LED bulbs were measured and evaluated in the same manner as in Example 1. These measurement / evaluation results are shown in Table 3.

  As apparent from Table 3, it is understood that practical brightness can be obtained while reducing the amount of ultraviolet light leakage of the LED bulb under various conditions. It was confirmed that all the light emission from the LED bulbs according to Examples 13 to 15 was excellent in color rendering properties and the glare was reduced.

  In addition, although several embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1 ... LED bulb, 2 ... LED module, 3 ... Base | substrate part, 4 ... Globe, 6 ... Base, 7 ... Substrate, 8 ... LED chip, 9 ... Ultraviolet to purple light absorption layer (particle layer), 10 ... Fluorescent film, 11 ... Transparent resin layer.

Claims (12)

An LED module comprising a substrate and an ultraviolet or purple LED chip mounted on the substrate;
A base portion on which the LED module is installed;
A glove attached to the base so as to cover the LED module;
Is formed on the inner wall surface of the glove, seen contains at least one kind of particles selected et or zinc oxide and cerium oxide arm, and ultraviolet or violet light absorbing layer having a thickness of 600μm or less the range of 10 [mu] m,
Fluorescence that is spaced apart from the LED chip and is provided on the inner surface side of the globe via the ultraviolet or violet light absorbing layer, and absorbs ultraviolet or violet light emitted from the LED chip and emits white light. A membrane,
A lighting circuit provided in the base portion for lighting the LED chip;
An LED bulb comprising: a base electrically connected to the lighting circuit. The LED bulb according to claim 1,
The LED bulb, wherein the particles contained in the ultraviolet to violet light absorbing layer have an average particle diameter of 0.1 μm or less. The LED bulb according to claim 1 or 2 ,
The LED bulb characterized in that the amount of leakage of the ultraviolet to purple light from the globe is less than 0.03 mW / nm / lm. The LED bulb according to any one of claims 1 to 3 ,
The LED bulb according to claim 1, wherein the phosphor film includes a blue phosphor, a green to yellow phosphor, and the red phosphor. The LED bulb according to claim 4 ,
The blue phosphor has the general formula: (Sr _1-xyz Ba _x Ca _y Eu _z ) ₅ (PO ₄ ) ₃ Cl
(Wherein x, y and z are numbers satisfying 0 ≦ x <0.5, 0 ≦ y <0.1, 0.005 ≦ z <0.1)
A europium-activated alkaline earth chlorophosphate phosphor having a composition represented by:
The green to yellow phosphor has the general _{formula: (Ba 1-xyz Sr x} Ca y Eu z) (Mg 1-u Mn u) Al 10 O 17
(In the formula, x, y, z, and u satisfy 0 ≦ x <0.2, 0 ≦ y <0.1, 0.005 <z <0.5, and 0.1 <u <0.5. Is the number to do)
Europium and manganese activated alkaline earth aluminate phosphors having the composition represented by:
General _{formula: (Sr 1-xyzu Ba x} Mg y Eu z Mn u) 2 SiO 4
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. 0.02)
Europium and manganese activated alkaline earth silicate phosphors having the composition represented by:
General formula: (Si, Al) ₆ (O, N) ₈ : Eu _x
(Wherein x is a number satisfying 0 <x <0.3)
Europium-activated sialon phosphor having a composition represented by the following formula: (Sr _1-x Eu _x ) _α Si _β Al _γ O _δ N _ω
(Where x, α, β, γ, δ, and ω are 0 <x <1, 0 <α ≦ 3, 12 ≦ β ≦ 14, 2 ≦ γ ≦ 3.5, 1 ≦ δ ≦ 3, 20 ≦ ω ≦ 22)
Is at least one selected from europium activated sialon phosphors having a composition represented by:
The red phosphor has the general _{formula: (La 1-xy Eu x} M y) 2 O 2 S
(In the formula, M represents at least one element selected from Sm, Ga, Sb, and Sn, and x and y satisfy 0.08 ≦ x <0.16 and 0.000001 ≦ y <0.003. Is the number to do)
A europium-activated lanthanum oxysulfide phosphor having a composition represented by:
General formula: (Ca _1-xy Sr _x Eu _y ) SiAlN ₃
(Wherein x and y are numbers satisfying 0 ≦ x <0.4 and 0 <x <0.5)
And a europium-activated couun phosphor having a composition represented by the general formula: (Sr _{1 -x} Eu _x ) _α Si _β Al _γ O _δ N _ω
(Where x, α, β, γ, δ, and ω are 0 <x <1, 0 <α ≦ 3, 5 ≦ β ≦ 9, 1 ≦ γ ≦ 5, 0.5 ≦ δ ≦ 2, 5 ≦ ω ≦ 15)
An LED bulb characterized by being at least one selected from europium-activated sialon phosphors having a composition represented by: The LED bulb according to claim 4 or 5 ,
The LED bulb according to claim 1, wherein the phosphor film further includes at least one phosphor selected from a blue-green phosphor and a deep red phosphor. The LED bulb according to claim 6 ,
The blue-green phosphor has the general _{formula: (Ba 1-xyzu Sr x} Mg y Eu z Mn u) 2 SiO 4
(Wherein x, y, z and u are 0.1 ≦ x ≦ 0.35, 0.025 ≦ y ≦ 0.105, 0.025 ≦ z ≦ 0.25, 0.0005 ≦ u ≦ 0. 0.02)
Europium and manganese activated alkaline earth silicate phosphors having the composition represented by:
The deep red phosphor has the general formula: αMgO.βMgF _2. (Ge _1-x Mn _x ) O ₂
(In the formula, α, β, and x are numbers satisfying 3.0 ≦ α ≦ 4.0, 0.4 ≦ β ≦ 0.6, and 0.001 ≦ x ≦ 0.5)
An LED bulb characterized by being a manganese-activated magnesium fluorogermanate phosphor having a composition represented by: The LED bulb according to any one of claims 4 to 7 ,
The phosphor film is 10% or more and 60% or less of the blue phosphor, 0% or more and 10% or less of the blue-green phosphor, 1% or more of 30% or less of the green to yellow phosphor, or 30% or more. An LED bulb comprising 90% or less of the red phosphor and 0% or more and 35% or less of the deep red phosphor. The LED bulb according to any one of claims 1 to 8 ,
The ultraviolet light emitted from the LED chip has an emission peak wavelength in a range of 370 nm to 410 nm, and a half width of an emission spectrum in a range of 10 nm to 15 nm. The LED bulb according to any one of claims 1 to 9 ,
The white light emitted from the fluorescent film has an correlated color temperature of 6500K or less and an average color rendering index (Ra) of 85 or more. The LED bulb according to any one of claims 1 to 10 ,
The LED module includes: a plurality of the LED chips surface-mounted on the substrate; and a transparent resin layer provided on the substrate so as to cover the plurality of LED chips. . The LED bulb according to any one of claims 1 to 11 ,
The globe has an LED bulb having a dome shape or an eggplant shape.

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