JP2007207532A - Lighting system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting system capable of restraining deterioration of phosphor particles. <P>SOLUTION: The lighting system 1 is composed of a phosphor sheet 51 made of a transparent resin 51a containing fluorescent particles 51b, a light transmitting member 52 covering both main faces 51c of the phosphor sheet 51, and a seal member 53 arranged on side face 51d side of the phosphor sheet 51. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lighting device.

  Light-emitting diodes are rapidly expanding in various fields such as backlights for liquid crystal displays, mobile phones, information terminals, and indoor / outdoor advertisements. In addition, light emitting diodes have long life and high reliability, and have features such as low power consumption, impact resistance, high purity display color, lightness, thinness, and so on. Application is also being attempted. When such a light emitting diode is applied to various uses, it is important to obtain white light.

  As a typical method for realizing white light with a light emitting diode, (1) a method using three light emitting diode chips emitting red, green and blue colors, and (2) a light emitting diode chip emitting blue light and yellow or There are three methods: a method of combining a phosphor that emits red light, and (3) a method of combining a light emitting diode chip that emits ultraviolet light and a mixed phosphor of three colors of red, green, and blue (see, for example, Patent Documents 1 and 2). .

  As the structure of the light-emitting diode, the light-emitting diode chip is placed in a cup shape such as a surface mount type (SMD) or a shell type, and a transparent resin mixed with phosphor particles emitting a desired color is poured and solidified. In general, a phosphor layer containing phosphor particles is formed, but in order to reduce color unevenness and color difference between cups, a phosphor sheet containing phosphor particles is used instead of the phosphor layer. May be placed.

  By the way, in stage lighting devices such as spotlights using light emitting diodes, cyan light, orange light, and red light are emitted in the light emitting diodes that emit white light in order to improve the average color rendering index (Ra). Light emitting diodes are mixed together and condensed by a lens to mix colors.

  However, in this case, the lens cannot completely collect the light and color unevenness occurs on the screen. Further, since various light emitting diodes having different light colors are used, the circuit becomes complicated.

  As a technique for solving these problems, it has been proposed to arrange the phosphor sheet as described above in the optical path. Specifically, for example, when a light emitting diode that emits blue light is used, a phosphor sheet containing green or yellow light emitting phosphor particles, or green or yellow light emitting phosphor particles and red light emitting phosphor particles, When a phosphor sheet containing white light is used as a light emitting diode, a phosphor sheet containing red light emitting phosphor particles is arranged in the optical path.

However, when the phosphor particles contained in the phosphor sheet are not excellent in water resistance, the phosphor particles absorb moisture contained in the atmosphere and, for example, sulfur components contained in the phosphor particles are dissolved. For this reason, the phosphor particles are deteriorated, the luminous flux maintenance factor is lowered, and the phosphor particles may be discolored.
JP 2004-179644 A Japanese Patent Laid-Open No. 2005-934986

  The present invention has been made to solve the above problems. That is, an object of the present invention is to provide an illumination device that can suppress deterioration of phosphor particles.

  The invention according to claim 1 is a phosphor sheet in which phosphor particles are contained in a transparent resin; a light transmissive member that covers both main surfaces of the phosphor sheet; and a side surface of the phosphor sheet. And a sealing member.

The invention according to claim 2 is characterized in that the sealing member is made of a resin that closes a gap between the light transmitting members and has an oxygen permeability of 30000 cc / cm ² · 24 h / atom or less. Item 2. The lighting device according to Item 1. Here, the reason why the oxygen permeability is set to 30000 cc / cm ² · 24 h / atom or less is that when the oxygen permeability exceeds this value, the effect is small, and deterioration under high temperature and high humidity with a particularly high degree of sealing cannot be suppressed. It is.

  The invention described in claim 3 is the lighting device according to claim 2, wherein the resin is an epoxy resin.

  A fourth aspect of the present invention is the illumination device according to any one of the first to third aspects, wherein the seal member is separated from a side surface of the phosphor sheet.

  The invention according to claim 5 further comprises a light emitting element, and the phosphor particles emit visible light when excited by light emitted from the light emitting element. It is an illuminating device as described in.

  According to the first aspect of the present invention, since both main surfaces of the phosphor sheet are covered with the light transmitting member, moisture in the atmosphere is prevented from coming into contact with the phosphor particles on the main surface side of the phosphor sheet. can do. Moreover, since the sealing member is arrange | positioned at the side surface side of a fluorescent substance sheet, it can suppress that the water | moisture content in air | atmosphere contacts fluorescent substance particles in the side surface side of a fluorescent substance sheet. Thereby, deterioration of phosphor particles can be suppressed.

According to the second aspect of the present invention, the gap between the light transmitting members is closed with the sealing member made of a resin having oxygen permeability of 30000 cc / cm ² · 24 h / atom or less. It is possible to suppress moisture in the atmosphere from entering through the gap, and it is possible to suppress moisture in the atmosphere from contacting the phosphor particles on the side surface side of the phosphor sheet. Thereby, deterioration of a fluorescent substance particle can be suppressed favorably.

  According to invention of Claim 3, since the epoxy resin has the outstanding water resistance, deterioration of fluorescent substance particle can be suppressed more.

  According to the invention of claim 4, since the sealing member is separated from the side surface of the phosphor sheet, the phosphor sheet extends in a direction along the main surface of the phosphor sheet due to thermal expansion due to the lighting heat of the lighting device. Even so, it is possible to suppress damage to the seal member. Moreover, since the light transmission member can suppress the film thickness change of the phosphor sheet due to thermal expansion, the color change can be suppressed.

  Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 is a schematic schematic configuration diagram of a lighting device according to the present embodiment, FIG. 2 is a schematic front view of the lighting device according to the present embodiment, and FIG. 3 relates to the present embodiment. It is a typical longitudinal section of a light conversion part. FIG. 4 is a schematic longitudinal sectional view of another light conversion unit according to the present embodiment, and FIG. 5 is a schematic diagram showing an operating state of the illumination device according to the present embodiment.

  The illuminating device 1 shown in FIGS. 1 to 5 is an illuminating device suitable for stage lighting, a spotlight, and the like, and includes an instrument body 2. The instrument body 2 is formed of, for example, a metal rectangular tube box, and a projection as a light emitting unit 3, an aperture unit 4, a light conversion unit 5, a fixing member 6, and a light control unit is provided inside the instrument body 2. The lens 7 is accommodated.

  The light emitting unit 3 includes light emitting diodes (LEDs) 31 as a plurality of light emitting elements that emit blue light, and is arranged so that blue light emitted from these light emitting diodes 31 is irradiated in a predetermined direction. . The light emitting diode 31 is not limited to emitting blue light, and may emit other light colors. As the light emitting diode 31, a surface mount type (SMD) or a shell type, or a high output power light emitting diode having a relatively large light output can be used.

  Further, each light emitting diode 31 may be provided with a diffusion sheet 32 in the blue light irradiation direction. Thereby, the blue light from the light emitting diode 31 can be uniformly irradiated in the direction of the aperture portion 4. However, since the light flux from the light emitting diode 31 is reduced when the diffusion sheet 32 is provided, it is preferably used in combination with a high output power light emitting diode.

  In the aperture section 4, an aperture 42 is formed in a partition wall 41 provided in a predetermined direction where the blue light of the light emitting diode 31 is irradiated. The plurality of light emitting diodes 31 are arranged so as to emit light toward the center of the aperture 42 so that blue light emitted in a region where the aperture 42 is located is mixed.

  The aperture unit 4 blocks non-homogeneous light outside the area of the aperture 42 out of the blue light of the plurality of light emitting diodes 31 provided in the light emitting unit 3, and is directed toward the projection lens 7 via the aperture 42, for example. The light of the light emitting diode 31 is emitted. The aperture area of the aperture 42 can be variably configured so that the non-uniform light can be regarded as a pseudo light source.

  Thus, since the aperture portion 4 is provided so that the aperture 42 is located at a predetermined position where the blue light beams of the plurality of light emitting diodes 31 provided in the light emitting portion 3 are condensed, the aperture 42 is simulated. It can be regarded as a light source.

  As shown in FIG. 3, the light conversion unit 5 includes a phosphor sheet 51 in which phosphor particles 51 b are contained in a transparent resin 51 a, a light transmission member 52 that covers both main surfaces 51 c of the phosphor sheet 51, and a fluorescent light The body sheet 51 is disposed on the side surface 51 d side, and includes a seal member 53 that closes a gap between the light transmission members 52.

  As the transparent resin 51a, for example, a silicone resin, an epoxy resin, or the like can be used. The phosphor particles 51b are excited by the light emitted from the light emitting diode 31 to emit visible light, and white light is generated by the color mixture of the visible light emitted from the phosphor particle 51b and the light emitted from the light emitting diode 31. Anything can be used.

  The phosphor particles 51b are mainly composed of a green or yellow light emitting phosphor. The green light emitting phosphor is excited by blue light emitted from the light emitting diode 31 to emit green light, and the yellow light emitting phosphor is excited by blue light emitted from the light emitting diode 31 to emit yellow light. is there. Further, in order to improve color rendering properties and the like, a red fluorescent material may be used in combination with a green or yellow light emitting material.

The green or yellow light emitting phosphor, for example (Sr, Ca) S: Eu , ZnS: Cu, SrGa 2 S 4: Eu, La 2 O 2 S: sulfide phosphor such as _Eu, RE 3 _(Al, Ga ) ₅ O ₁₂ : YAG phosphor such as Ce (RE represents at least one selected from Y, Gd and La), AE ₂ SiO ₄ : Eu (AE is an alkaline earth element such as Sr, Ba and Ca) Silicate phosphor, n-UVLEDBGR, nitride phosphor, oxynitride phosphor, sialon, organic phosphor, etc. can be used.

  In order to obtain a desired amount of light from the light emitting diode 31, the phosphor sheet 51 is 5-20% by mass, preferably 10-15% by mass, and mixed with the transparent resin 51a. Is formed.

  As the light transmitting member 52, two flat light transmitting members 52 are shown in FIG. 3, but a box-shaped light transmitting member 52 having an opening 52a on the side surface is used as shown in FIG. May be. In this case, the phosphor sheet 51 is placed in the box-shaped light transmission member 52 and the opening 52 a is closed by the seal member 53.

  The light transmitting member 52 is not particularly limited as long as it transmits light. As the light transmission member 52, for example, glass, transparent resin, or the like can be used. Of these, glass is preferably used because it is excellent in water resistance and light transmittance. Moreover, when the surface of the light transmission member 52 is roughened, it also has a function as a diffusion sheet.

The seal member 53 is made of a resin having an oxygen permeability of 30000 cc / cm ² · 24 h / atom or less. Examples of such a resin include an epoxy resin (oxygen permeability: 10 cc / cm ² · 24 h / atom), an acrylic resin (oxygen permeability: 150 cc / cm ² · 24 h / atom), and a polycarbonate (oxygen permeability: 1800 cc / cm ² · 24 h / atom).

  The seal member 53 is provided so as to cover all the side surfaces 51 d of the phosphor sheet 51. The seal member 53 is not necessarily provided so as to cover all the side surfaces 51d of the phosphor sheet 51. For example, as shown in FIG. 4, when a part of the side surface 51 d of the phosphor sheet 51 is covered with the light transmitting member 52, the seal member 53 is covered with the light transmitting member 52 of the phosphor sheet 51. What is necessary is just to cover the side 51d which is not.

  The seal member 53 is separated from the side surface 51 d of the phosphor sheet 51. That is, there is a gap between the seal member 53 and the side surface 51 d of the phosphor sheet 51. In consideration of the deterioration of the phosphor particles 51b due to moisture present in the atmosphere, it is desirable to deaerate air or the like present in the gap.

  The fixing member 6 fixes the light conversion unit 5 at a predetermined position, and is attached to the outer peripheral edge of the light conversion unit 5. The fixing member 6 fixes the light transmitting member 52 by sandwiching it from both sides. By providing the fixing member 6, the light conversion unit 5 can be fixed at a predetermined position, and the main surface 51 c of the phosphor sheet 51 and the light transmitting member 52 can be brought into close contact with each other. Note that the fixing member 6 does not have to hold the light transmitting member 52 from both sides.

  The projection lens 7 controls the area and the like for irradiating the irradiated surface S such as a screen with white light from the light conversion unit 5. The projection lens 7 can be constituted by a spherical lens or a flat lens. In this embodiment, a case where one Fresnel lens is used is shown.

  The instrument body 2 is provided with a moving mechanism (not shown) that relatively changes the distance between the projection lens 7 and the aperture 42 or the light emitting unit 3. This moving mechanism includes a light source focus handle 8 and a lens focus handle 9. By operating these handles 8 and 9 and relatively changing the separation interval between the light emitting unit 3 and the projection lens 7, a screen or the like is obtained. The irradiated area on the irradiated surface S is changed, and the amount of light is changed.

  The front surface of the instrument body 2 on the projection lens 7 side is provided with a plurality of banders 10 on its four sides, and the irradiation range of light from the projection lens 7 is adjusted by appropriately adjusting the opening and closing angles of these banders 10. Can be adjusted to be shielded from light within a desired range.

  A lighting device storage unit 11 is disposed below the fixture body 2, and the lighting device storage unit 11 stores a lighting device 12 that supplies a desired lighting power to the light emitting diode 31. The lighting device 12 converts the supplied commercial power source into a low wattage (W) direct current suitable for the light emitting diode, and from the light emitting diode 31 according to a dimming signal such as a DMX signal output from the outside. White light can be obtained by adjusting the intensity of emitted blue light.

In the present embodiment, since both the main surfaces 51c of the phosphor sheet 51 are covered with the light transmitting member 52, moisture in the atmosphere contacts the phosphor particles 51b on the main surface 51c side of the phosphor sheet 51. Can be suppressed. Further, since the gap between the light transmission members 52 is closed with a sealing member 53 made of a resin having an oxygen permeability of 30000 cc / cm ² · 24 h / atom or less, the gap between the light transmission members 52 is opened in the atmosphere. It is possible to prevent moisture from entering, and to prevent moisture in the atmosphere from contacting the phosphor particles 51b on the side surface 51d side of the phosphor sheet 51. Thereby, deterioration of the phosphor particles 51b can be suppressed. Although it is possible to cover the entire phosphor sheet 51 with glass, in this case, since the glass needs to be melted, the phosphor sheet 51 cannot withstand the heat at the time of melting the glass and deteriorates. There is a fear. In addition, since the epoxy resin is excellent in water resistance, when the epoxy resin is used as the transparent resin 51a, the water resistance of the phosphor sheet 51 can be improved. If the member 52 and the seal member 53 are not provided, the phosphor particles 51b exposed on the surface of the phosphor sheet 51 are deteriorated.

  The phosphor sheet 51 is thermally expanded because the temperature of the phosphor sheet 51 is increased by the irradiation of the blue light emitted from the light emitting diode 31. Here, in the case where the outer peripheral edge of the light conversion unit 5 is sandwiched between the fixing members 6, the phosphor sheet 51 extends in a direction along the main surface 51c of the phosphor sheet 51 due to thermal expansion. If the side surface 51d of the phosphor sheet 51 and the seal member 53 are in close contact, the seal member 53 may be damaged. On the other hand, in the present embodiment, since there is a gap between the phosphor sheet 51 and the seal member 53, the phosphor sheet 51 extends in the direction along the main surface 51c of the phosphor sheet 51 due to thermal expansion. However, the sealing member 53 is not easily damaged. Moreover, since the change of the film thickness of the phosphor sheet 51 due to thermal expansion can be suppressed by the light transmitting member 52, the color change can be suppressed.

  When the outer peripheral edge of the light conversion unit 5 is not sandwiched between the fixing members 6, the phosphor sheet 51 is not only in the direction along the main surface 51c of the phosphor sheet 51 but also in the thickness direction due to thermal expansion. Although the film is stretched, if the phosphor sheet 51 is cooled and contracts, a gap is generated between the phosphor sheet 51 and the light transmitting member 52, and a desired light distribution may not be obtained due to light refraction. On the other hand, in this embodiment, since the sealing member 53 is disposed between the light transmitting members 52, the sealing member 53 expands and contracts following the thermal expansion and contraction of the phosphor sheet 51. Thereby, it is hard to produce a clearance gap between the fluorescent substance sheet 51 and the light transmissive member 52, and desired light distribution can be obtained.

(Example 1 and Comparative Examples 1 and 2)
Hereinafter, Example 1 and Comparative Examples 1 and 2 will be described. In Example 1 and Comparative Examples 1 and 2, different light conversion parts were produced, and the luminous flux maintenance factor after 500 hours from the initial stage and the degree of discoloration of the phosphor particles were examined.

  The light conversion unit used in Example 1 had the same structure as that described in the above embodiment. That is, in addition to the phosphor sheet, a light transmitting member and a sealing member are provided. As the phosphor sheet, a silicone resin containing 15% by mass of ZnS: Eu as a green light emitting phosphor was used, and as the light transmitting member, soda-lime glass having a thickness of 1 mm was used. Moreover, an epoxy resin was used as the seal member.

  The light conversion part used in Comparative Example 1 was only a phosphor sheet, and was neither provided with a light transmitting member nor a sealing member. In addition, the light conversion unit used in Comparative Example 2 was provided with a light transmitting member in addition to a phosphor, but was not provided with a seal member. The phosphor sheets of Comparative Examples 1 and 2 were the same as those in Example 1, and the light transmissive member of Comparative Example 2 was the same as that in Example 1.

  Then, a high-temperature / high-humidity test was performed on the light conversion parts of Example 1 and Comparative Examples 1 and 2 to examine the luminous flux maintenance factor after 500 hours from the initial stage and the degree of discoloration of the phosphor particles. . The high-temperature and high-humidity test was performed by arranging the light conversion parts in test chambers maintained at a temperature of 85 ° C. and a humidity of 85%. The change in efficiency was measured by the gonio method.

The results will be described below.

  As shown in Table 1, the luminous flux maintenance factor in Comparative Examples 1 and 2 was low, and there were many phosphor particles that were discolored. In contrast, the luminous flux maintenance factor in Example 1 was high, and the phosphor particles were not discolored. From these results, it was confirmed that the deterioration of the phosphor particles can be suppressed by providing the light transmitting member and such a sealing member.

(Example 2 and Comparative Examples 3 and 4)
Hereinafter, Example 2 and Comparative Examples 3 and 4 will be described. In Example 2 and Comparative Examples 3 and 4, different light conversion parts were produced, and the luminous flux maintenance factor after 500 hours from the initial stage and the degree of discoloration of the phosphor particles were examined.

  The light conversion unit used in Example 2 had the same structure as that described in the above embodiment. That is, in addition to the phosphor sheet, a light transmitting member and a sealing member are provided. As the phosphor sheet, a material in which an organic phosphor is contained as a red light emitting phosphor in silicone was used, and as the light transmitting member, soda-lime glass having a thickness of 1 mm was used. Moreover, an epoxy resin was used as the seal member.

  The light conversion part used in Comparative Example 3 was a phosphor sheet only, and neither a light transmission member nor a seal member was provided. In addition, the light conversion unit used in Comparative Example 4 was provided with a light transmitting member in addition to a phosphor, but was not provided with a seal member. The phosphor sheet of Comparative Examples 3 and 4 was the same as that of Example 2, and the light transmissive member of Comparative Example 4 was the same as that of Example 2.

  And the high temperature and high humidity test was done with respect to the light conversion part of such Example 2 and Comparative Examples 3 and 4, and the luminous flux maintenance factor after 500 hours with respect to the initial stage and the degree of discoloration of the phosphor particles were examined. . The high-temperature and high-humidity test was performed by arranging the light conversion parts in test chambers maintained at a temperature of 85 ° C. and a humidity of 85%. The change in efficiency was measured by the gonio method.

The results will be described below.

  As shown in Table 2, the luminous flux maintenance factor in Comparative Examples 3 and 4 was low, and many phosphor particles were discolored. On the other hand, the luminous flux maintenance factor in Example 2 was high, and the phosphor particles were not discolored. From these results, it was confirmed that the deterioration of the phosphor particles can be suppressed by providing the light transmitting member and such a sealing member.

  The present invention is not limited to the description of the above embodiment, and the structure, material, arrangement of each member, and the like can be appropriately changed without departing from the gist of the present invention.

It is a typical schematic block diagram of the illuminating device which concerns on embodiment. It is a typical front view of the illuminating device which concerns on embodiment. It is a typical longitudinal cross-sectional view of the light conversion part which concerns on embodiment. It is a typical longitudinal cross-sectional view of the other light conversion part which concerns on embodiment. It is a schematic diagram which shows the operation state of the illuminating device which concerns on embodiment.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Illuminating device, 31 ... Light emitting diode, 5 ... Light conversion part, 51 ... Phosphor sheet, 51a ... Transparent resin, 51b ... Phosphor particle, 51c ... Main surface, 51d ... Side surface, 52 ... Light transmission member, 53 ... Seal member.

Claims (5)

A phosphor sheet containing phosphor particles in a transparent resin;
A light transmissive member covering both main surfaces of the phosphor sheet;
A sealing member disposed on a side surface of the phosphor sheet;
An illumination device comprising: The lighting device according to claim 1, wherein the sealing member is made of a resin that closes a gap between the light transmitting members and has an oxygen transmission rate of 30000 cc / cm ² · 24 h / atom or less.   The lighting device according to claim 2, wherein the resin is an epoxy resin.   The lighting device according to any one of claims 1 to 3, wherein the seal member is separated from a side surface of the phosphor sheet.   5. The illumination device according to claim 1, further comprising a light emitting element, wherein the phosphor particle emits visible light when excited by light emitted from the light emitting element.

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