JP2012009472A

JP2012009472A - Light-emitting device

Info

Publication number: JP2012009472A
Application number: JP2010141250A
Authority: JP
Inventors: Daisuke Kobayashi; 大介小林
Original assignee: Konica Minolta Opto Inc
Current assignee: Konica Minolta Opto Inc
Priority date: 2010-06-22
Filing date: 2010-06-22
Publication date: 2012-01-12

Abstract

PROBLEM TO BE SOLVED: To suppress a color shift with simple constitution.SOLUTION: The light-emitting device 2A includes: a light emitting element 5 which radially emits light; a first light guide member 10 which guides a part of light on the outer side having a large angle with an optical axis PA, which is a beam of light emitted from a center part of the light emitting element 5; a first reflection surface 26 which reflects a part of light on the inner side having a small angle with the optical axis PA, among the light emitted from the light emitting element 5; and a second reflection surface 28 which further reflects the light reflected by the first reflection surface 26.

Description

本発明は発光装置に関する。 The present invention relates to a light emitting device.

従来より、照明などの用途においてＬＥＤ素子からの光を励起光として用いて蛍光体を発光させることで、白色光を得る発光装置が開発されている。
このような発光装置としては、たとえば、（ｉ）ＬＥＤ素子から出射された青色光により黄色光を出射する蛍光体を用い、それぞれの光を混色させることで白色光とする発光装置や、（ｉｉ）ＬＥＤ素子から出射された紫外光により、青色、緑色、赤色の光を出射する蛍光体を用いて、蛍光体から出射された３色の光を混色させることで白色光とする発光装置などが知られている。これらの発光装置では、配光分布が色ごとに異なるため色ずれが生じる。 2. Description of the Related Art Conventionally, a light emitting device that obtains white light by causing a phosphor to emit light using light from an LED element as excitation light in applications such as lighting has been developed.
As such a light emitting device, for example, (i) a phosphor that emits yellow light by blue light emitted from an LED element, and a light emitting device that produces white light by mixing each light, (ii) ) Using a phosphor that emits blue, green, and red light with ultraviolet light emitted from the LED element, a light emitting device that produces white light by mixing three colors of light emitted from the phosphor Are known. In these light emitting devices, the color distribution is different because the light distribution is different for each color.

色ずれを解消する方法として、特許文献１のように拡散剤を用いる方法が知られている。特許文献１の技術では、蛍光体を含むコーティング樹脂（１０１）で発光素子（１０２）を覆い、そのコーティング樹脂に対し拡散剤を含有させている（段落００２７，００２８，００６４や図１など）。
しかし、（ｉ）拡散剤を用いる場合、拡散剤での光吸収や拡散による発光装置内部への戻り光のために光取出し効率が低下するという問題が存在する。（ｉｉ）拡散剤を用いると、製造工程で生じた拡散剤の密度むらによって配光分布が変化し配光制御が困難になるといった問題や、拡散剤混入工程により製造コストが増加する問題も存在する。 As a method for eliminating color misregistration, a method using a diffusing agent as in Patent Document 1 is known. In the technique of Patent Document 1, the light emitting element (102) is covered with a coating resin (101) containing a phosphor, and a diffusing agent is contained in the coating resin (paragraphs 0027, 0028, 0064, FIG. 1, etc.).
However, when (i) a diffusing agent is used, there is a problem that the light extraction efficiency is reduced due to light absorption by the diffusing agent and return light to the inside of the light emitting device due to diffusion. (Ii) When a diffusing agent is used, there is a problem that the distribution of light distribution changes due to uneven density of the diffusing agent generated in the manufacturing process, making it difficult to control the light distribution, and a problem that the manufacturing cost increases due to the diffusing agent mixing process. To do.

色ずれを解消する他の方法として、特許文献２のように導光部材を使用する方法が考えられる。特許文献２の技術では、光源ユニット（１）に対し複数の導光部材（２０_１〜２０_５）を同心円状に重なるように（入れ子状に）配置し、これら導光部材を支持部材（２１）で支持するという構成を採用している（段落００１６や図１，図２など）。特許文献２の技術によれば、拡散剤を使用しないから、光取出し効率の低下や配光制御の困難性、製造コストの増大といった拡散剤の不都合を解消することができる。 As another method for eliminating the color misregistration, a method using a light guide member as in Patent Document 2 can be considered. In the technique of Patent Document 2, a plurality of light guide members (20 _{1 to} 20 ₅ ) are arranged concentrically (in a nested manner) with respect to the light source unit (1), and these light guide members are supported by a support member (21 ) Is employed (paragraph 0016, FIGS. 1 and 2, etc.). According to the technique of Patent Document 2, since a diffusing agent is not used, inconveniences of the diffusing agent such as a decrease in light extraction efficiency, difficulty in light distribution control, and an increase in manufacturing cost can be solved.

特開２０００−２０８８１５号公報JP 2000-208815 A 特開２００８−０８４６１９号公報JP 2008-084619 A

しかしながら、特許文献２の技術では、互いに大きさが対応する入れ子状の導光部材やこれを支持する支持部材を専用品として製造する必要があり、これら製造にかかる手間やコストなどを考慮すると、特許文献２の発光装置は実用的であるとはいい難い。
したがって、本発明の主な目的は、拡散剤を用いることなく、簡易な構成で色ずれを抑制することができる高効率な発光装置を提供することにある。 However, in the technology of Patent Document 2, it is necessary to manufacture a nested light guide member and a support member supporting the same corresponding to each other in size, and considering the labor and cost for manufacturing these, It is difficult to say that the light-emitting device of Patent Document 2 is practical.
Therefore, a main object of the present invention is to provide a highly efficient light-emitting device that can suppress color misregistration with a simple configuration without using a diffusing agent.

上記課題を解決するため本発明によれば、
放射状に発光する発光素子と、
前記発光素子から放射される光のうち、発光素子の中心部から出射される光の光線を光軸として、前記光軸との成す角が大きい外側の一部の光を導光する第１の導光部材と、
前記発光素子から出射される光のうち、前記光軸との成す角が小さい内側の一部の光を反射する第１の反射面と、
前記第１の反射面で反射された光をさらに反射する第２の反射面と、
を備えることを特徴とする発光装置が提供される。 In order to solve the above problems, according to the present invention,
A light emitting element that emits light radially;
A first light that guides a part of the outer light having a large angle with the optical axis, with the light beam emitted from the central portion of the light emitting element as the optical axis among the light emitted from the light emitting element. A light guide member;
A first reflecting surface that reflects a portion of the light emitted from the light emitting element and having a small angle with the optical axis;
A second reflecting surface for further reflecting the light reflected by the first reflecting surface;
A light emitting device is provided.

本発明によれば、発光素子の光を導光する導光部材と２つの反射面とを準備するという簡易な構成で、拡散剤を用いることなく、発光素子の色ずれを抑制することができる。 According to the present invention, it is possible to suppress color misregistration of a light-emitting element without using a diffusing agent with a simple configuration in which a light guide member that guides light of the light-emitting element and two reflecting surfaces are prepared. .

第１の実施形態にかかる発光装置の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the light-emitting device concerning 1st Embodiment. 図１の発光装置の作用（光の伝播）を説明するための図面である。It is drawing for demonstrating the effect | action (light propagation) of the light-emitting device of FIG. 図１の発光装置の変形例を示す断面図である。It is sectional drawing which shows the modification of the light-emitting device of FIG. 図１の発光装置の変形例を示す断面図である。It is sectional drawing which shows the modification of the light-emitting device of FIG. 第２の実施形態にかかる発光装置の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the light-emitting device concerning 2nd Embodiment. 図５の発光装置の変形例を示す断面図である。It is sectional drawing which shows the modification of the light-emitting device of FIG. 第３の実施形態にかかる発光装置の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the light-emitting device concerning 3rd Embodiment. 第４の実施形態にかかる発光装置の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the light-emitting device concerning 4th Embodiment. 第５の実施形態にかかる発光装置の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the light-emitting device concerning 5th Embodiment. 図９の発光装置の導光部材の概略構成を示す分解断面図である。FIG. 10 is an exploded cross-sectional view illustrating a schematic configuration of a light guide member of the light emitting device of FIG. 9. 図１０の発光装置の作用（光の伝播）を説明するための図面である。It is drawing for demonstrating the effect | action (light propagation) of the light-emitting device of FIG. 第１〜第５の実施形態にかかる発光装置の比較例の概略構成を示す断面図である。It is sectional drawing which shows schematic structure of the comparative example of the light-emitting device concerning 1st-5th embodiment. シミュレーションの結果（配光分布）を示す図面である。It is drawing which shows the result (light distribution) of simulation. シミュレーションの結果（色度ＣＩＥｘ）を示す図面である。It is drawing which shows the result (chromaticity CIEx) of simulation. シミュレーションの結果（色度ＣＩＥｙ）を示す図面である。It is drawing which shows the result (chromaticity CIEy) of simulation.

以下、図面を参照しながら本発明の好ましい実施形態について説明する。 Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

［第１の実施形態］
図１に示すとおり、発光装置２Ａは実装基板４を有している。
実装基板４には放射状に発光する発光素子５が設けられている。
発光素子５は主に、特定波長の光を出射するＬＥＤチップ６と、ＬＥＤチップ６の光の波長を変換する波長変換素子８とで構成されている。 [First Embodiment]
As shown in FIG. 1, the light emitting device 2 A has a mounting substrate 4.
The mounting substrate 4 is provided with light emitting elements 5 that emit light radially.
The light emitting element 5 mainly includes an LED chip 6 that emits light of a specific wavelength, and a wavelength conversion element 8 that converts the wavelength of the light of the LED chip 6.

ＬＥＤチップ６はＬＥＤ素子の一例であり、特定波長の光（本実施形態では青色光）を出射するものである。
ＬＥＤチップ６としては、公知の青色ＬＥＤチップを用いることができる。
青色ＬＥＤチップとしては、Ｉｎ_xＧａ_1-xＮ系をはじめ既存のあらゆるものを使用することができる。青色ＬＥＤチップの発光ピーク波長は４４０〜４８０ｎｍのものが好ましい。
なお、ＬＥＤチップ６の出射光の波長及び蛍光体層中の蛍光体の出射光の波長は限定されず、ＬＥＤチップ６による出射光の波長と、蛍光体による出射光の波長とが補色関係にあり合成された光が白色光となる組合せであればものであれば、ＬＥＤチップ６として使用可能であるが、本発明の効果を得るためには、ＬＥＤチップ６の出射光及び蛍光体の出射光の波長はそれぞれ可視光であることが好ましい。
ＬＥＤチップ６の形態としては、実装基板４上にＬＥＤチップを実装し、そのまま上方または側方に放射させるタイプ、又は、サファイア基板などの透明実装基板４上に青色ＬＥＤチップを実装し、その表面にバンプを形成した後、裏返して基板上の電極と接続する、いわゆるフリップチップ接続タイプなど、どのような形態のＬＥＤチップでも適用することが可能だが、高輝度タイプやレンズ使用タイプの製造方法により適するフリップチップタイプがより好ましい。 The LED chip 6 is an example of an LED element, and emits light having a specific wavelength (blue light in the present embodiment).
A known blue LED chip can be used as the LED chip 6.
As the blue LED chip, any existing one including In _x Ga _1-x N can be used. The emission peak wavelength of the blue LED chip is preferably 440 to 480 nm.
The wavelength of the emitted light from the LED chip 6 and the wavelength of the emitted light from the phosphor in the phosphor layer are not limited, and the wavelength of the emitted light from the LED chip 6 and the wavelength of the emitted light from the phosphor are in a complementary color relationship. As long as the combined light becomes white light, it can be used as the LED chip 6. However, in order to obtain the effect of the present invention, the emitted light from the LED chip 6 and the emission of the phosphors can be obtained. The wavelength of the incident light is preferably visible light.
As a form of the LED chip 6, the LED chip is mounted on the mounting substrate 4, and the blue LED chip is mounted on the transparent mounting substrate 4 such as a sapphire substrate or the like. It can be applied to any form of LED chip, such as flip chip connection type, where bumps are formed on the substrate and then flipped over and connected to the electrodes on the substrate. A suitable flip chip type is more preferred.

図１中の拡大部に示すとおり、波長変換素子８は主にガラス基板８ａとセラミック層８ｂとから構成されたもので、ガラス基板８ａに対しセラミック層８ｂが形成されたものである。
ガラス基板８ａは低融点ガラスや金属ガラスなどから構成されている。ガラス基板８ａは樹脂製の基板とされてもよい。
セラミック層８ｂはガラス基板８ａの上面に形成されている。セラミック層８ｂはガラス基板８ａの上面と下面との両方に設けられてもよい。
セラミック層８ｂはセラミック前駆体、溶媒および蛍光体を含む混合物の焼成体であり、蛍光体が分散した状態で含有されている。
下記では、セラミック前駆体（溶媒を含む。）と蛍光体とについて簡単に説明する。 As shown in the enlarged portion in FIG. 1, the wavelength conversion element 8 is mainly composed of a glass substrate 8a and a ceramic layer 8b, and a ceramic layer 8b is formed on the glass substrate 8a.
The glass substrate 8a is made of low-melting glass or metal glass. The glass substrate 8a may be a resin substrate.
The ceramic layer 8b is formed on the upper surface of the glass substrate 8a. The ceramic layer 8b may be provided on both the upper and lower surfaces of the glass substrate 8a.
The ceramic layer 8b is a sintered body of a mixture including a ceramic precursor, a solvent, and a phosphor, and is contained in a state where the phosphor is dispersed.
Below, a ceramic precursor (a solvent is included) and fluorescent substance are demonstrated easily.

（１）セラミック前駆体
溶媒を含むセラミック前駆体（セラミック前駆体溶液）は金属化合物を含む溶液であるが、透光性のセラミックスを形成することができれば金属の種類に制限はない。
セラミック前駆体溶液は、加水分解等の反応によりゲル化した後、ゲルを加熱、焼成することによりセラミックスが形成されるものであってもよいし、溶媒成分を揮発させることにより、ゲル化することなく直接セラミックスが形成されるものであってもよい。
前者（ゾルゲル溶液）の場合、金属化合物は有機化合物でもよいし無機化合物でもよい。好ましい金属化合物としては、例えば、金属アルコキシド、金属アセチルアセトネート、金属カルボキシレート、硝酸塩、酸化物などが挙げられる。中でも金属アルコキシドは、加水分解と重合反応によりゲル化し易いため好ましく、特にテトラエトキシシランが好ましく用いられる。また、複数種の金属化合物を組み合わせて使用してもよい。 (1) Ceramic precursor Although the ceramic precursor (ceramic precursor solution) containing a solvent is a solution containing a metal compound, the type of metal is not limited as long as a translucent ceramic can be formed.
The ceramic precursor solution may be gelled by a reaction such as hydrolysis, and then the ceramic may be formed by heating and firing the gel, or by gelling the solvent component. Alternatively, ceramics may be directly formed.
In the former case (sol-gel solution), the metal compound may be an organic compound or an inorganic compound. Examples of preferable metal compounds include metal alkoxides, metal acetylacetonates, metal carboxylates, nitrates, and oxides. Of these, metal alkoxides are preferred because they are easily gelled by hydrolysis and polymerization reaction, and tetraethoxysilane is particularly preferred. A plurality of types of metal compounds may be used in combination.

（２）蛍光体
蛍光体は、ＬＥＤチップ６から出射される所定波長の光をそれとは異なる波長の光に変換するものである。本実施形態では、ＬＥＤチップ４から出射される青色光を黄色光に変換するようになっている。
このような蛍光体としては、（Ａ１）又は（Ａ２）の工程と（Ｂ）の工程とを経て形成された焼結体が好ましく使用される。
（Ａ１）Ｙ、Ｇｄ、Ｃｅ、Ｓｍ、Ａｌ、Ｌａ及びＧａの酸化物、又は高温で容易に酸化物になる化合物を、化学量論比で十分に混合して混合原料を得る。
（Ａ２）Ｙ、Ｇｄ、Ｃｅ、Ｓｍの希土類元素を化学量論比で酸に溶解した溶解液を蓚酸で共沈したものを焼成して得られる共沈酸化物と、酸化アルミニウム、酸化ガリウムとを混合して混合原料を得る。
（Ｂ）（Ａ１），（Ａ２）の各工程で得られた混合原料のいずれか一方に対し、フラックスとしてフッ化アンモニウム等のフッ化物を適量混合して加圧し、成形体を得る。その後、成形体を坩堝に詰め、空気中１３５０〜１４５０℃の温度範囲で２〜５時間焼成して、蛍光体の発光特性を持った焼結体を得ることができる。 (2) Phosphor The phosphor converts light having a predetermined wavelength emitted from the LED chip 6 into light having a different wavelength. In the present embodiment, blue light emitted from the LED chip 4 is converted into yellow light.
As such a phosphor, a sintered body formed through the steps (A1) or (A2) and the step (B) is preferably used.
(A1) An oxide of Y, Gd, Ce, Sm, Al, La, and Ga, or a compound that easily becomes an oxide at a high temperature is sufficiently mixed in a stoichiometric ratio to obtain a mixed raw material.
(A2) a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of oxalic acid with a solution obtained by dissolving rare earth elements of Y, Gd, Ce, and Sm in an acid in a stoichiometric ratio with oxalic acid; To obtain a mixed raw material.
(B) An appropriate amount of fluoride such as ammonium fluoride as a flux is mixed and pressed against any one of the mixed raw materials obtained in the steps (A1) and (A2) to obtain a molded body. Thereafter, the molded body is packed in a crucible and fired in the temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a sintered body having the light emission characteristics of the phosphor.

本実施形態ではＹＡＧ蛍光体を使用しているが、蛍光体の種類はこれに限定されるものではない。蛍光体としては、たとえば、Ｃｅを含まない非ガーネット系蛍光体などの他の蛍光体を使用することもできる。 In this embodiment, a YAG phosphor is used, but the type of the phosphor is not limited to this. As the phosphor, for example, another phosphor such as a non-garnet phosphor not containing Ce can be used.

なお、波長変換素子８は、ＬＥＤチップ６の側部にも設置されてもよいし（ＬＥＤチップ６を被覆するように設置してもよいし）、ＬＥＤチップ６から離れた位置に設置されてもよい。 The wavelength conversion element 8 may be installed on the side of the LED chip 6 (may be installed so as to cover the LED chip 6), or installed at a position away from the LED chip 6. Also good.

実装基板４には導光部材１０が設けられている。
導光部材１０はほぼ半球状（お椀形状）を呈しており、内周面１２が曲面状を呈している。導光部材１０の底部には円形状の孔部１４が形成されている。導光部材１０は、発光素子５の中央部から出射される光の光線（光軸ＰＡ）を回転中心とした回転対称体である。
導光部材１０は、発光素子５から発される光の一部であって光軸ＰＡとの成す角が大きい光を導光するための部材である。 A light guide member 10 is provided on the mounting substrate 4.
The light guide member 10 has a substantially hemispherical shape (a bowl shape), and the inner peripheral surface 12 has a curved shape. A circular hole 14 is formed at the bottom of the light guide member 10. The light guide member 10 is a rotationally symmetric body with the light beam (optical axis PA) emitted from the central portion of the light emitting element 5 as the rotation center.
The light guide member 10 is a member for guiding light that is a part of light emitted from the light emitting element 5 and has a large angle with the optical axis PA.

導光部材１０の内部には、第２の導光部材２０が配置されている。導光部材２０は、発光素子５から発される光の一部であって光軸ＰＡとの成す角が小さい光を導光するための部材である。導光部材２０に導光する当該光は、導光部材１０に導光する光よりも、光軸ＰＡとの成す角が小さい。
導光部材２０も、導光部材１０の内周に沿うようなほぼ半球状（お椀形状）を呈しており、光軸ＰＡを回転中心とした回転対称体である。導光部材２０の底部２２は導光部材１０の孔部１４を貫通した状態で実装基板４に支持（接着）されている。
底部２２には空間部２４が形成されており、空間部２４のほぼ中央部に発光素子５が配置されている。上記蛍光体を分散した樹脂を空間部２４に充填して、この部位を波長変換素子８として機能させてもよい。
導光部材１０と導光部材２０との間には、微小な隙間（空気層９）が形成されている。空気層９は導光部材１０，２０より光の屈折率が低い。 A second light guide member 20 is disposed inside the light guide member 10. The light guide member 20 is a member for guiding light that is a part of light emitted from the light emitting element 5 and has a small angle with the optical axis PA. The light guided to the light guide member 20 has a smaller angle with the optical axis PA than the light guided to the light guide member 10.
The light guide member 20 also has a substantially hemispherical shape (a bowl shape) along the inner periphery of the light guide member 10, and is a rotationally symmetric body with the optical axis PA as the center of rotation. The bottom portion 22 of the light guide member 20 is supported (adhered) to the mounting substrate 4 in a state of penetrating the hole portion 14 of the light guide member 10.
A space portion 24 is formed in the bottom portion 22, and the light emitting element 5 is disposed at a substantially central portion of the space portion 24. The space 24 may be filled with a resin in which the phosphor is dispersed, and this portion may function as the wavelength conversion element 8.
A minute gap (air layer 9) is formed between the light guide member 10 and the light guide member 20. The air layer 9 has a lower light refractive index than the light guide members 10 and 20.

導光部材２０には２つの反射面２６，２８が形成されている。
反射面２６は発光素子５の光を全反射する面であり、反射面２８は反射面２６で反射した光を全反射する面である。反射面２６は断面視して直線状を呈している。反射面２８は導光部１０の内周面１２に沿う曲面であり、断面視して曲線状を呈している。反射面２８の高さを「Ｔ１」とした場合、反射面２６は反射面２８の１／２Ｔ１以下の高さ位置に配置されている。 Two reflecting surfaces 26 and 28 are formed on the light guide member 20.
The reflection surface 26 is a surface that totally reflects the light of the light emitting element 5, and the reflection surface 28 is a surface that totally reflects the light reflected by the reflection surface 26. The reflection surface 26 has a straight line shape when viewed in cross section. The reflection surface 28 is a curved surface along the inner peripheral surface 12 of the light guide unit 10 and has a curved shape when viewed in cross section. When the height of the reflective surface 28 is “T1”, the reflective surface 26 is disposed at a height position equal to or lower than 1 / 2T1 of the reflective surface 28.

導光部材１０，２０はガラスまたは樹脂（樹脂成形品）で構成されている。導光部材１０，２０を構成する樹脂としてはシリコーン樹脂やアクリル樹脂、ポリカーボネート樹脂などを使用することができる。 The light guide members 10 and 20 are made of glass or resin (resin molded product). As the resin constituting the light guide members 10 and 20, silicone resin, acrylic resin, polycarbonate resin, or the like can be used.

発光装置２Ａによれば、ＬＥＤチップ６が発光して青色光を出射すると、この青色光はガラス基板８ａを透過してセラミック層８ｂの蛍光体に入射する。
すると、この青色光によって励起された蛍光体から黄色光が出射され、その結果、青色光と蛍光体で生じた黄色光とが重ね合わされ、白色光が発光素子５から出射される。
その後、図２に示すとおり、光軸ＰＡとの成す角が大きい光は導光部材１０に伝播し、外周面１６や内周面１２で反射して発光装置２Ａの外側に出射される。
他方、光軸ＰＡとの成す角が小さい光は導光部材２０に伝播し、反射面２６と反射面２８とで反射して発光装置２Ａの外側に出射される。
特に、導光部材２０に伝播した光線は、反射面２６で反射された後、反射面２８以外では反射作用を受けずに、反射面２８で１回または複数回反射される。その光線を断面視した場合、反射面２６に入射する光の光線と光軸ＰＡとのなす角度を「α」と、反射面２６で反射した光の光線と光軸ＰＡとのなす角度を「β」と、反射面２８で反射した光の光線と光軸ＰＡとのなす角度を「γ」とすると、反射面２６での反射後の角度βは反射前の角度αより大きく、反射面２８での反射後の角度γは反射前の角度βより小さくなる。これらの関係は式（１），（２）で表され、発光装置２Ａでは式（１），（２）の両方の条件を満たしている。
α＜β … （１）
γ＜β … （２） According to the light emitting device 2A, when the LED chip 6 emits light and emits blue light, the blue light passes through the glass substrate 8a and enters the phosphor of the ceramic layer 8b.
Then, yellow light is emitted from the phosphor excited by the blue light. As a result, the blue light and the yellow light generated by the phosphor are superimposed, and white light is emitted from the light emitting element 5.
Thereafter, as shown in FIG. 2, light having a large angle with the optical axis PA propagates to the light guide member 10, is reflected by the outer peripheral surface 16 and the inner peripheral surface 12, and is emitted to the outside of the light emitting device 2A.
On the other hand, light having a small angle with the optical axis PA propagates to the light guide member 20, is reflected by the reflecting surface 26 and the reflecting surface 28, and is emitted to the outside of the light emitting device 2A.
In particular, the light beam propagated to the light guide member 20 is reflected by the reflecting surface 26 and then reflected by the reflecting surface 28 one or more times without receiving a reflecting action other than the reflecting surface 28. When the light beam is viewed in cross section, the angle formed between the light beam incident on the reflecting surface 26 and the optical axis PA is “α”, and the angle formed between the light beam reflected on the reflecting surface 26 and the optical axis PA is “ If the angle formed between β ”and the light beam reflected by the reflecting surface 28 and the optical axis PA is“ γ ”, the angle β after reflection at the reflecting surface 26 is larger than the angle α before reflection, and the reflecting surface 28 The angle γ after reflection at is smaller than the angle β before reflection. These relationships are expressed by equations (1) and (2), and the light emitting device 2A satisfies both conditions of equations (1) and (2).
α <β (1)
γ <β (2)

以上の発光装置２Ａによれば、セラミック層８ｂにおいて拡散剤を含有させることで光を拡散させて青色励起光と蛍光を混色しなくても、発光素子５の光を導光するために、２つの導光部材１０，２０を設置するという簡易な構成で、発光素子５の色ずれを抑制することができる。 According to the light emitting device 2A described above, in order to guide the light of the light emitting element 5 without diffusing light by mixing the diffusing agent in the ceramic layer 8b and mixing blue excitation light and fluorescence, 2 The color shift of the light emitting element 5 can be suppressed with a simple configuration in which the two light guide members 10 and 20 are installed.

なお、第１の実施形態にかかる発光装置２Ａでは、反射面２６と反射面２８とが導光部材２０に形成されていればよく、下記のように変形させてもよい。
たとえば、図３に示すとおり、導光部材２０の外径を導光部材１０の外径と同一とし、上部３０を導光部材１０の上部に密着させてもよい。この場合、導光部材２０を実装基板４に接着しなくてもよい。
図４（ａ）に示すとおり、導光部材１０に底部３２を設けて導光部材２０の底部２２を底部３２に密着させてもよい。この場合、好ましくは、発光素子５の放射状に広がる光の経路を確保できる程度に、実装基板４に凹部３４を形成して発光素子５を実装基板４に埋没させる。
図４（ｂ）に示すとおり、導光部材２０を導光部材１０とほぼ同様の形状とし、導光部材２０の底部２２に孔部３６を形成してもよい。 In the light emitting device 2A according to the first embodiment, the reflecting surface 26 and the reflecting surface 28 may be formed on the light guide member 20, and may be modified as follows.
For example, as illustrated in FIG. 3, the outer diameter of the light guide member 20 may be the same as the outer diameter of the light guide member 10, and the upper portion 30 may be in close contact with the upper portion of the light guide member 10. In this case, the light guide member 20 may not be bonded to the mounting substrate 4.
As shown in FIG. 4A, the light guide member 10 may be provided with a bottom 32 so that the bottom 22 of the light guide member 20 is in close contact with the bottom 32. In this case, preferably, the recessed portion 34 is formed in the mounting substrate 4 and the light emitting device 5 is embedded in the mounting substrate 4 to such an extent that a light path of the light emitting device 5 spreading radially can be secured.
As illustrated in FIG. 4B, the light guide member 20 may have a shape substantially similar to that of the light guide member 10, and the hole 36 may be formed in the bottom portion 22 of the light guide member 20.

［第２の実施形態］
第２の実施形態にかかる発光装置（２Ｂ）は第１の実施形態にかかる発光装置２Ａと下記の点で異なっており、それ以外は第１の実施形態と同様となっている。
図５に示すとおり、実装基板４には凹部３４が形成され、発光素子５が凹部３４に埋没するように実装されている。
導光部材１０には底部３２が形成され、底部３２には突起部４０が形成されている。突起部４０には反射面４２が形成されている。反射面４２は第１の実施形態にかかる反射面２６に相当する面であり、発光素子５が放射した光を全反射する。反射面４２も反射面２８の１／２Ｔ１以下の高さ位置に配置されている。
導光部材２０の外径が導光部材１０の外径と同一となっている。導光部材２０の上部３０が導光部材１０の上部に密着している。 [Second Embodiment]
The light emitting device (2B) according to the second embodiment is different from the light emitting device 2A according to the first embodiment in the following points, and is otherwise the same as in the first embodiment.
As shown in FIG. 5, a recess 34 is formed in the mounting substrate 4, and the light emitting element 5 is mounted so as to be buried in the recess 34.
A bottom portion 32 is formed on the light guide member 10, and a protrusion 40 is formed on the bottom portion 32. A reflective surface 42 is formed on the protrusion 40. The reflecting surface 42 is a surface corresponding to the reflecting surface 26 according to the first embodiment, and totally reflects the light emitted from the light emitting element 5. The reflection surface 42 is also disposed at a height position of 1 / 2T1 or less of the reflection surface 28.
The outer diameter of the light guide member 20 is the same as the outer diameter of the light guide member 10. The upper part 30 of the light guide member 20 is in close contact with the upper part of the light guide member 10.

以上の発光装置２Ｂによれば、発光素子５が放射した光のうち、光軸ＰＡとの成す角が大きい光は導光部材１０に伝播して発光装置２Ａの外側に出射され、光軸ＰＡとの成す角が小さい光は導光部材１０の反射面４２と導光部材２０の反射面２８とで反射して発光装置２Ａの外側に出射される。特に、導光部材２０に伝播した光線は、反射面２８以外では反射作用を受けずに、反射面２８で１回または複数回反射される。
この場合に、発光装置２Ｂによれば、第１の実施形態にかかる反射面２６に相当する面（反射面４２）が導光部材１０に一体形成される点で発光装置２Ａと異なっているものの、発光素子５の光を導光するために、２つの導光部材１０，２０を設置するという簡易な構成で、発光素子５の色ずれを抑制することができる。 According to the light emitting device 2B described above, light having a large angle formed with the optical axis PA out of the light emitted from the light emitting element 5 propagates to the light guide member 10 and is emitted to the outside of the light emitting device 2A. The light having a small angle is reflected by the reflection surface 42 of the light guide member 10 and the reflection surface 28 of the light guide member 20 and emitted to the outside of the light emitting device 2A. In particular, the light beam propagated to the light guide member 20 is reflected by the reflecting surface 28 one or more times without receiving a reflecting action except for the reflecting surface 28.
In this case, the light emitting device 2B differs from the light emitting device 2A in that a surface corresponding to the reflective surface 26 according to the first embodiment (the reflective surface 42) is integrally formed with the light guide member 10. In order to guide the light of the light emitting element 5, the color shift of the light emitting element 5 can be suppressed with a simple configuration in which the two light guide members 10 and 20 are installed.

［第３の実施形態］
第２の実施形態にかかる発光装置（２Ｃ）は第１の実施形態にかかる発光装置２Ａと下記の点で異なっており、それ以外は第１の実施形態と同様となっている。
図６に示すとおり、実装基板４には凹部３４が形成され、発光素子５が凹部３４に埋没するように実装されている。
導光部材１０の内周面１２には反射膜５０が形成されている。反射膜５０は金属材料を蒸着して形成された金属薄膜または誘電体多層膜である。反射膜５０を金属薄膜とする場合には、たとえば、アルミニウムや銀などを形成材料として使用することができ、好ましくはアルミニウムを好適に使用することができる。反射膜５０の表面５０ａは第１の実施形態にかかる反射面２８として機能する面となる。
導光部材２０に代えて反射部材５２が設けられている。反射部材５２は円錐状を呈した部材であり、その頂点が発光素子５に対し対向配置されている。反射部材５２の円錐面（側面）は反射面５４となっている。反射面５４は第１の実施形態にかかる反射面２６に相当する面である。反射膜５０の高さを「Ｔ２」とした場合、反射面５４は反射膜５０の１／２Ｔ２以下の高さ位置に配置されている。 [Third Embodiment]
The light emitting device (2C) according to the second embodiment is different from the light emitting device 2A according to the first embodiment in the following points, and is otherwise the same as in the first embodiment.
As shown in FIG. 6, a recess 34 is formed in the mounting substrate 4, and the light emitting element 5 is mounted so as to be buried in the recess 34.
A reflective film 50 is formed on the inner peripheral surface 12 of the light guide member 10. The reflective film 50 is a metal thin film or a dielectric multilayer film formed by evaporating a metal material. When the reflective film 50 is a metal thin film, for example, aluminum or silver can be used as a forming material, and aluminum can be preferably used. The surface 50a of the reflective film 50 is a surface that functions as the reflective surface 28 according to the first embodiment.
A reflective member 52 is provided in place of the light guide member 20. The reflecting member 52 is a member having a conical shape, and the apex thereof is disposed to face the light emitting element 5. The conical surface (side surface) of the reflecting member 52 is a reflecting surface 54. The reflection surface 54 is a surface corresponding to the reflection surface 26 according to the first embodiment. When the height of the reflective film 50 is “T2”, the reflective surface 54 is disposed at a height position of 1 / 2T2 or less of the reflective film 50.

以上の発光装置２Ｃによれば、発光素子５が放射した光のうち、光軸ＰＡとの成す角が大きい光は導光部材１０に伝播して発光装置２Ａの外側に出射され、光軸ＰＡとの成す角が小さい光は反射部材５２の反射面５４と反射膜５０の表面５０ａとで反射して発光装置２Ａの外側に出射される。
この場合に、発光装置２Ｃによれば、第１の実施形態にかかる反射面２８として機能する面（反射膜５０の表面５０ａ）が導光部材１０に一体形成される点で発光装置２Ａと異なっているものの、発光素子５の光を導光するために、導光部材１０と反射部材５２とを設置するという簡易な構成で、発光素子５の色ずれを抑制することができる。 According to the light emitting device 2C described above, of the light emitted from the light emitting element 5, light having a large angle with the optical axis PA propagates to the light guide member 10 and is emitted to the outside of the light emitting device 2A. The light having a small angle is reflected by the reflecting surface 54 of the reflecting member 52 and the surface 50a of the reflecting film 50 and emitted to the outside of the light emitting device 2A.
In this case, the light emitting device 2C differs from the light emitting device 2A in that the surface functioning as the reflective surface 28 according to the first embodiment (the surface 50a of the reflective film 50) is integrally formed with the light guide member 10. However, color misregistration of the light emitting element 5 can be suppressed with a simple configuration in which the light guide member 10 and the reflecting member 52 are installed in order to guide the light of the light emitting element 5.

なお、第３の実施形態にかかる発光装置２Ｃでは、図７に示すとおり、導光部材１０に底部３２を設けて反射部材５２の底部を底部３２に密着させてもよいし、反射面５４に反射膜５０と同様の金属薄膜または誘電体多層膜を形成してもよい。 In the light emitting device 2 C according to the third embodiment, as shown in FIG. 7, the bottom portion 32 may be provided on the light guide member 10 so that the bottom portion of the reflecting member 52 is in close contact with the bottom portion 32. A metal thin film or a dielectric multilayer film similar to the reflective film 50 may be formed.

［第４の実施形態］
第４の実施形態にかかる発光装置（２Ｄ）は第１の実施形態にかかる発光装置２Ａと下記の点で異なっており、それ以外は第１の実施形態と同様となっている。
図８に示すとおり、実装基板４には凹部３４が形成され、発光素子５が凹部３４に埋没するように実装されている。
導光部材１０には底部３２が形成され、底部３２には突起部４０が形成されている。突起部４０には反射面４２が形成されている。反射面４２は第１の実施形態にかかる反射面２６に相当する面である。
導光部材１０の内周面１２には反射膜５０が形成されている。反射膜５０は金属材料を蒸着して形成された金属薄膜または誘電体多層膜である。反射膜５０を金属薄膜とする場合には、たとえば、アルミニウムや銀などを形成材料として使用することができ、好ましくはアルミニウムを好適に使用することができる。反射膜５０の表面５０ａは第１の実施形態にかかる反射面２８として機能する面となる。反射膜５０の高さを「Ｔ２」とした場合、反射面４２は反射膜５０の１／２Ｔ２以下の高さ位置に配置されている。 [Fourth Embodiment]
The light emitting device (2D) according to the fourth embodiment is different from the light emitting device 2A according to the first embodiment in the following points, and is otherwise the same as in the first embodiment.
As shown in FIG. 8, a recess 34 is formed in the mounting substrate 4, and the light emitting element 5 is mounted so as to be buried in the recess 34.
A bottom portion 32 is formed on the light guide member 10, and a protrusion 40 is formed on the bottom portion 32. A reflective surface 42 is formed on the protrusion 40. The reflecting surface 42 is a surface corresponding to the reflecting surface 26 according to the first embodiment.
A reflective film 50 is formed on the inner peripheral surface 12 of the light guide member 10. The reflective film 50 is a metal thin film or a dielectric multilayer film formed by evaporating a metal material. When the reflective film 50 is a metal thin film, for example, aluminum or silver can be used as a forming material, and aluminum can be preferably used. The surface 50a of the reflective film 50 is a surface that functions as the reflective surface 28 according to the first embodiment. When the height of the reflective film 50 is “T2”, the reflective surface 42 is disposed at a height position equal to or lower than 1 / 2T2 of the reflective film 50.

以上の発光装置２Ｄによれば、発光素子５が放射した光のうち、光軸ＰＡとの成す角が大きい光は導光部材１０に伝播して発光装置２Ａの外側に出射され、光軸ＰＡとの成す角が小さい光は導光部材１０の反射面４２と反射膜５０の表面５０ａとで反射して発光装置２Ａの外側に出射される。
この場合に、発光装置２Ｄによれば、第１の実施形態にかかる反射面２６に相当する面（反射面４２）と、第１の実施形態にかかる反射面２８として機能する面（反射膜５０の表面５０ａ）とが、導光部材１０に一体形成される点で発光装置２Ａと異なっているものの、発光素子５の光を導光するために、導光部材１０のみを設置するという簡易な構成で、発光素子５の色ずれを抑制することができる。 According to the light emitting device 2D, light having a large angle with the optical axis PA among the light emitted from the light emitting element 5 propagates to the light guide member 10 and is emitted to the outside of the light emitting device 2A. The light having a small angle is reflected by the reflecting surface 42 of the light guide member 10 and the surface 50a of the reflecting film 50 and is emitted to the outside of the light emitting device 2A.
In this case, according to the light emitting device 2D, a surface corresponding to the reflecting surface 26 according to the first embodiment (the reflecting surface 42) and a surface functioning as the reflecting surface 28 according to the first embodiment (the reflecting film 50). The surface 50a) is different from the light emitting device 2A in that it is integrally formed with the light guide member 10, but only the light guide member 10 is installed to guide the light of the light emitting element 5. With the configuration, the color shift of the light emitting element 5 can be suppressed.

［第５の実施形態］
第５の実施形態にかかる発光装置（２Ｅ）は第１の実施形態にかかる発光装置２Ａと下記の点で異なっており、それ以外は第１の実施形態と同様となっている。
図９に示すとおり、実装基板４には凹部３４が形成され、発光素子５が凹部３４に埋没するように実装されている。
導光部材１０には底部３２が設けられ、導光部材２０の底部２２が底部３２に密着している。 [Fifth Embodiment]
The light emitting device (2E) according to the fifth embodiment is different from the light emitting device 2A according to the first embodiment in the following points, and is otherwise the same as the first embodiment.
As shown in FIG. 9, a recess 34 is formed in the mounting substrate 4, and the light emitting element 5 is mounted so as to be buried in the recess 34.
The light guide member 10 is provided with a bottom portion 32, and the bottom portion 22 of the light guide member 20 is in close contact with the bottom portion 32.

図９，図１０に示すとおり、導光部材２０の内部には、第３の導光部材６０，第４の導光部材７０が入れ子状に設けられている。
導光部材６０は、導光部材２０の内周に沿うようなほぼ半球状（お椀形状）を呈しており、光軸ＰＡを回転中心とした回転対称体である。導光部材６０は底部６２が導光部材２０の底部２２に密着している。
導光部材６０には２つの反射面６４，６６が形成されている。
反射面６４，６６は、第１の実施形態にかかる反射面２６，２８と同様の光学作用を奏する面である。すなわち、反射面６４は発光素子５の光を全反射する面であり、反射面６６は反射面６４で反射した光を全反射する面である。反射面６４は断面視して直線状を呈している。反射面６６は導光部２０の内周面に沿う曲面であり、断面視して曲線状を呈している。
導光部材２０と導光部材６０との間には、微小な隙間（空気層６８）が形成されている。空気層６８は導光部材２０，６０より光の屈折率が低い。 As shown in FIGS. 9 and 10, a third light guide member 60 and a fourth light guide member 70 are nested inside the light guide member 20.
The light guide member 60 has a substantially hemispherical shape (a bowl shape) along the inner periphery of the light guide member 20, and is a rotationally symmetric body with the optical axis PA as the center of rotation. The bottom portion 62 of the light guide member 60 is in close contact with the bottom portion 22 of the light guide member 20.
Two reflecting surfaces 64 and 66 are formed on the light guide member 60.
The reflecting surfaces 64 and 66 are surfaces that exhibit the same optical action as the reflecting surfaces 26 and 28 according to the first embodiment. That is, the reflective surface 64 is a surface that totally reflects the light of the light emitting element 5, and the reflective surface 66 is a surface that totally reflects the light reflected by the reflective surface 64. The reflection surface 64 has a straight line shape when viewed in cross section. The reflection surface 66 is a curved surface along the inner peripheral surface of the light guide unit 20 and has a curved shape when viewed in cross section.
A minute gap (air layer 68) is formed between the light guide member 20 and the light guide member 60. The air layer 68 has a light refractive index lower than that of the light guide members 20 and 60.

導光部材７０は、導光部材６０の内部に設けられている。
導光部材７０は、導光部材６０の内周に沿うようなほぼ半球状（お椀形状）を呈しており、光軸ＰＡを回転中心とした回転対称体である。導光部材７０は底部７２が導光部材６０の底部６２に密着している。
導光部材７０には２つの反射面７４，７６が形成されている。
反射面７４，７６は、第１の実施形態にかかる反射面２６，２８と同様の光学作用を奏する面である。すなわち、反射面７４は発光素子５の光を全反射する面であり、反射面７６は反射面７４で反射した光を全反射する面である。反射面７４は断面視して直線状を呈している。反射面７６は導光部６０の内周面に沿う曲面であり、断面視して曲線状を呈している。
導光部材６０と導光部材７０との間には、微小な隙間（空気層７８）が形成されている。空気層７８は導光部材６０，７０より光の屈折率が低い。 The light guide member 70 is provided inside the light guide member 60.
The light guide member 70 has a substantially hemispherical shape (a bowl shape) along the inner periphery of the light guide member 60, and is a rotationally symmetric body with the optical axis PA as the center of rotation. The bottom portion 72 of the light guide member 70 is in close contact with the bottom portion 62 of the light guide member 60.
Two reflecting surfaces 74 and 76 are formed on the light guide member 70.
The reflecting surfaces 74 and 76 are surfaces that exhibit the same optical action as the reflecting surfaces 26 and 28 according to the first embodiment. That is, the reflective surface 74 is a surface that totally reflects the light of the light emitting element 5, and the reflective surface 76 is a surface that totally reflects the light reflected by the reflective surface 74. The reflection surface 74 has a straight line shape when viewed in cross section. The reflecting surface 76 is a curved surface along the inner peripheral surface of the light guide unit 60, and has a curved shape when viewed in cross section.
A minute gap (air layer 78) is formed between the light guide member 60 and the light guide member 70. The air layer 78 has a lower light refractive index than the light guide members 60 and 70.

導光部材６０，７０は、導光部材１０，２０と同様に、ガラスまたは樹脂（樹脂成形品）で構成されている。導光部材６０，７０を構成する樹脂としてはシリコーン樹脂やアクリル樹脂、ポリカーボネート樹脂などを使用することができる。 The light guide members 60 and 70 are made of glass or resin (resin molded product), similarly to the light guide members 10 and 20. As the resin constituting the light guide members 60 and 70, silicone resin, acrylic resin, polycarbonate resin, or the like can be used.

以上の光学装置２Ｅによれば、導光部材１０，２０，６０，７０による入れ子状の構造を有しており、導光部材６０，７０は導光部材２０とほぼ同じ形状と光学作用を有している。
そのため、図１１に示すとおり、発光素子５が放射した光のうち、光軸ＰＡとの成す角が大きい光は導光部材１０に伝播して発光装置２Ｅの外側に出射され、光軸ＰＡとの成す角が小さい光は導光部材２０の反射面２６と反射面２８とで反射して発光装置２Ｅの外側に出射され、光軸ＰＡとの成す角が（導光部材２０に入射する光よりも）さらに小さい光は導光部材６０，７０の反射面６４，７４と反射面６６，７６とで反射して発光装置２Ｅの外側に出射される。
特に、導光部材２０に伝播した光線は、反射面２６で反射された後、反射面２８以外では反射作用を受けずに、反射面２８で１回または複数回反射される。
導光部材６０に入射した光のうち、導光部材２０中を透過した光よりも光軸ＰＡに近い光が、導光部材６０と作用する。すなわち、導光部材６０は、導光部材２０を透過した光のうち、光軸ＰＡに近い一部の光に作用する。導光部材６０に伝播した光線は、反射面６４で反射された後、反射面６６以外では反射作用を受けずに、反射面６６で１回または複数回反射される。
導光部材７０に入射した光のうち、導光部材６０中を透過した光よりも光軸ＰＡに近い光が、導光部材７０と作用する。すなわち、導光部材７０は、導光部材６０を透過した光のうち、光軸ＰＡに近い一部の光に作用する。導光部材７０に伝播した光線は、反射面７４で反射された後、反射面７６以外では反射作用を受けずに、反射面７６で１回または複数回反射される。
この場合に、発光装置２Ｅによれば、導光部材６０，７０が増設されている点で発光装置２Ａと異なっているものの、発光素子５の光を導光するために、導光部材１０，２０，６０，７０を設置するという簡易な構成で、発光素子５の色ずれを抑制することができる。 According to the optical device 2E described above, the light guide members 10, 20, 60 and 70 have a nested structure, and the light guide members 60 and 70 have substantially the same shape and optical action as the light guide member 20. is doing.
Therefore, as shown in FIG. 11, light having a large angle formed with the optical axis PA out of the light emitted from the light emitting element 5 propagates to the light guide member 10 and is emitted to the outside of the light emitting device 2E. The light having a small angle is reflected by the reflection surface 26 and the reflection surface 28 of the light guide member 20 and emitted to the outside of the light emitting device 2E, and the angle formed by the optical axis PA is (light incident on the light guide member 20). Smaller light is reflected by the reflection surfaces 64 and 74 and the reflection surfaces 66 and 76 of the light guide members 60 and 70 and is emitted to the outside of the light emitting device 2E.
In particular, the light beam propagated to the light guide member 20 is reflected by the reflecting surface 26 and then reflected by the reflecting surface 28 one or more times without receiving a reflecting action other than the reflecting surface 28.
Of the light incident on the light guide member 60, light closer to the optical axis PA than the light transmitted through the light guide member 20 acts on the light guide member 60. In other words, the light guide member 60 acts on a part of the light transmitted through the light guide member 20 and near the optical axis PA. The light beam propagated to the light guide member 60 is reflected by the reflecting surface 64 and then reflected by the reflecting surface 66 one or more times without receiving a reflecting action except for the reflecting surface 66.
Of the light incident on the light guide member 70, light closer to the optical axis PA than the light transmitted through the light guide member 60 acts on the light guide member 70. That is, the light guide member 70 acts on a part of the light that passes through the light guide member 60 and is close to the optical axis PA. The light beam propagated to the light guide member 70 is reflected by the reflecting surface 74 and then reflected by the reflecting surface 76 one or more times without being subjected to a reflecting action except for the reflecting surface 76.
In this case, the light emitting device 2E differs from the light emitting device 2A in that light guide members 60 and 70 are added, but in order to guide the light of the light emitting element 5, the light guide members 10 and The color shift of the light emitting element 5 can be suppressed with a simple configuration in which 20, 60, and 70 are installed.

第１〜第４の実施形態にかかる発光装置２Ａ，２Ｂ，２Ｃ，２Ｄの構造で十分な色ずれの改善効果はあるが、第５の実施形態にかかる光学装置２Ｅのように、複数の導光部材１０，２０，６０，７０を入れ子構造にすることにより、光学装置５Ｅにおける出射面（各導光部材１０，２０，６０，７０の図９中の上面）での発光を面内で一様にすることができ、かつ、その光をより正面に向けて（図９中の上方に向けて）集光させることができる。 Although the structure of the light emitting devices 2A, 2B, 2C, and 2D according to the first to fourth embodiments has a sufficient effect of improving color misregistration, a plurality of light guides are provided like the optical device 2E according to the fifth embodiment. By making the optical members 10, 20, 60, 70 nested, light emission on the emission surface (the upper surface in FIG. 9 of each light guide member 10, 20, 60, 70) in the optical device 5 E is integrated within the surface. In addition, the light can be focused toward the front (upward in FIG. 9).

第５の実施形態にかかる光学装置２Ｅによれば、複数の導光部材１０，２０，６０，７０を光学的に接触させればフレネル反射を抑えることができ、第１の実施形態にかかる発光装置２Ａと同等の光取り出し効率を実現することができる。
第５の実施形態にかかる発光装置２Ｅでは、導光部材１０，２０，６０，７０の数（入れ子の重数）は適宜変更可能であり、３つの導光部材１０，２０，６０で入れ子構造を構成してもよいし、４つの導光部材１０，２０，６０，７０に対しさらにこれと同様の導光部材を加えた５つ以上の導光部材で入れ子構造を構成してもよい。 According to the optical device 2E according to the fifth embodiment, Fresnel reflection can be suppressed by optically contacting the light guide members 10, 20, 60, and 70, and light emission according to the first embodiment. Light extraction efficiency equivalent to that of the apparatus 2A can be realized.
In the light emitting device 2E according to the fifth embodiment, the number of light guide members 10, 20, 60, and 70 (the number of nestings) can be appropriately changed, and the three light guide members 10, 20, and 60 are nested. Alternatively, a nested structure may be configured by five or more light guide members obtained by adding the same light guide member to the four light guide members 10, 20, 60, and 70.

以上の第１〜第５の実施形態にかかる発光装置２Ａ〜２Ｅによれば、特許文献２の発光装置と比較すると、各発光装置２Ａ〜２Ｅは製造にかかる手間やコストが特許文献２の装置よりも少なくて済むという利点がある。
たとえば、発光装置２Ａ〜２Ｄは特許文献２の装置よりも部品点数が少ない。
特許文献２の装置では、複数の導光部材（２０_１〜２０_５）だけでは自立しないため、これら導光部材を吊り下げ固定するための支持部材（２１）が必須であるのに対し、各発光装置２Ａ〜２Ｅは各導光部材１０，２０などが安定しており、基本的に支持部材が不要であり、仮に支持部材が必要であっても簡素なものでよい。 According to the light emitting devices 2A to 2E according to the first to fifth embodiments described above, the light emitting devices 2A to 2E are devices of Patent Document 2 that are troublesome to manufacture and cost compared to the light emitting device of Patent Document 2. There is an advantage that less than that.
For example, the light emitting devices 2 A to 2 D have fewer parts than the device of Patent Document 2.
In the apparatus of Patent Document 2, since a plurality of light guide members (20 _{1 to} 20 ₅ ) are not self-supporting, a support member (21) for suspending and fixing these light guide members is essential. In the light emitting devices 2A to 2E, the light guide members 10, 20 and the like are stable, basically no support member is required, and even if a support member is necessary, it may be simple.

第１〜第５の実施形態にかかる発光装置２Ａ〜２Ｅによれば、特許文献２の発光装置よりも光取り出し効率が高いという利点がある。
すなわち、特許文献２の発光装置では、発光素子（ＬＥＤチップ１０）を外部から遮断するためにカバー（１３）が必要であり、発光素子の光は、カバーと導光部材によって少なくとも４回は光学面を透過し、フレネル反射損失が大きい。
他方、第１〜第５の実施形態にかかる発光装置２Ａ〜２Ｅでは、導光部材１０，２０自体によって発光素子５を外部から遮断でき、カバーが不要であるため、発光素子５の光は、光学面を透過する回数が特許文献２の装置よりも少なくて済む。接触している光学面同士が密着していれば（図５の発光装置２Ｂ以外では）、反射面２６，２８またはこれに相当する面を含む光路を伝播する光が、光学面でフレネル反射を受ける回数は２回で済む。また、図１の発光装置２Ａ以外では、導光部材１０を透過する光が光学面でフレネル反射を受ける回数は２回で済む。第３，第４の実施形態にかかる発光装置２Ｃ，２Ｄは、反射膜５０として金属薄膜などが使用され反射面で多少の損失は生じうるが、部品構成が簡素になる利点がある。特に、第４の実施形態にかかる発光装置２Ｄでは、光を導光するための部品点数が１つだけで足りるという利点がある。 According to the light emitting devices 2A to 2E according to the first to fifth embodiments, there is an advantage that the light extraction efficiency is higher than that of the light emitting device of Patent Document 2.
That is, in the light emitting device of Patent Document 2, the cover (13) is necessary to block the light emitting element (LED chip 10) from the outside, and the light of the light emitting element is optically transmitted at least four times by the cover and the light guide member. The surface is transmitted and the Fresnel reflection loss is large.
On the other hand, in the light emitting devices 2A to 2E according to the first to fifth embodiments, the light emitting element 5 can be blocked from the outside by the light guide members 10 and 20 themselves, and a cover is unnecessary. The number of times of transmission through the optical surface is less than that of the device disclosed in Patent Document 2. If the contacting optical surfaces are in close contact with each other (other than the light emitting device 2B in FIG. 5), the light propagating on the optical path including the reflecting surfaces 26 and 28 or a surface corresponding thereto reflects Fresnel reflection on the optical surface. You only need to receive it twice. In addition to the light emitting device 2A shown in FIG. 1, the number of times that the light transmitted through the light guide member 10 is subjected to Fresnel reflection on the optical surface may be two. In the light emitting devices 2C and 2D according to the third and fourth embodiments, a metal thin film or the like is used as the reflection film 50 and some loss may occur on the reflection surface, but there is an advantage that the component configuration is simplified. In particular, the light emitting device 2D according to the fourth embodiment has an advantage that only one component is required to guide light.

［シミュレーションとその結果］
図４（ｂ）の発光装置２Ａ，図６の発光装置２Ｃ，図１２の発光装置２Ｘの３つの各発光装置を製造し、それら各発光装置においてフレネル反射損を考慮したシミュレーションを行い、配光分布と角度ごとの色度を計算した。 [Simulation and results]
The light emitting device 2A in FIG. 4B, the light emitting device 2C in FIG. 6, and the light emitting device 2X in FIG. 12 are manufactured, and simulation is performed in consideration of Fresnel reflection loss in each of the light emitting devices. The chromaticity for each distribution and angle was calculated.

図４（ｂ）の発光装置２Ａ，図６の発光装置２Ｃでは、導光部材１０を厚さ１ｍｍ，外径１０ｍｍの半球とし、導光部材２０を厚さ１ｍｍ，外径７．８ｍｍの半球とした。図１２の発光装置２Ｘは第１〜第５の実施形態にかかる発光装置２Ａ〜２Ｅの比較例であり、導光部材１０などに代えて、単レンズ８０を使用している。単レンズ８０では、曲率半径を２．６８ｍｍと、平面部を含めて厚さを１０ｍｍとした。導光部材１０，２０や反射部材５２、単レンズ８０の材質は全てガラス（ＢＫ７）とした。図６の発光装置２Ｃでは、反射膜５０と反射面５４をアルミニウム薄膜で構成した。
発光素子５として、青色ＬＥＤチップと黄色蛍光体（セラミック層８ｂ中の蛍光体）とを組み合わせたものを使用した。導光部材１０，２０や反射部材５２、単レンズ８０による色ずれ発生の効果を確認するため、波長変換素子８（蛍光体の発光部形状）を青色ＬＥＤチップのサイズより大きくした。青色ＬＥＤチップの大きさを０．３５ｍｍ角とし、波長変換素子８（蛍光体の発光部形状）を直径０．７ｍｍの円として、ランバーシャン発光とした。
なお、図４（ｂ）の発光装置２Ａでは、図１〜図４（ａ）の発光装置２Ａと異なり、導光部材２０の内周面３８が球面形状を呈しているが、内周面３８には光線が当たらないため、導光部材２０の肉厚を薄くしなければ、内周面３８はどのような形状であっても、シミュレーション結果に影響を与えない。 In the light emitting device 2A of FIG. 4B and the light emitting device 2C of FIG. 6, the light guide member 10 is a hemisphere having a thickness of 1 mm and an outer diameter of 10 mm, and the light guide member 20 is a hemisphere having a thickness of 1 mm and an outer diameter of 7.8 mm. It was. A light emitting device 2X of FIG. 12 is a comparative example of the light emitting devices 2A to 2E according to the first to fifth embodiments, and uses a single lens 80 instead of the light guide member 10 and the like. In the single lens 80, the radius of curvature was 2.68 mm, and the thickness including the flat portion was 10 mm. The light guide members 10 and 20, the reflecting member 52, and the single lens 80 are all made of glass (BK7). In the light emitting device 2C of FIG. 6, the reflective film 50 and the reflective surface 54 are made of an aluminum thin film.
As the light emitting element 5, a combination of a blue LED chip and a yellow phosphor (phosphor in the ceramic layer 8b) was used. In order to confirm the effect of color misregistration due to the light guide members 10, 20, the reflecting member 52, and the single lens 80, the wavelength conversion element 8 (the shape of the light emitting portion of the phosphor) was made larger than the size of the blue LED chip. The size of the blue LED chip was 0.35 mm square, and the wavelength conversion element 8 (the shape of the light emitting portion of the phosphor) was a circle with a diameter of 0.7 mm, resulting in Lambertian light emission.
4B, unlike the light emitting device 2A shown in FIGS. 1 to 4A, the inner peripheral surface 38 of the light guide member 20 has a spherical shape. Since the light beam does not hit, the simulation result is not affected regardless of the shape of the inner peripheral surface 38 unless the light guide member 20 is thinned.

以上の条件におけるシミュレーションの結果を、図１３〜図１５に示す。
図１５に示すとおり、３つの発光装置２Ａ，２Ｃ，Ｂでは全て光を正面に集光する。
図１６と図１７は角度ごとの色度で、横軸が光軸からの角度を表している。
図１６，図１７に示すとおり、発光装置２Ｘでは、１５〜２０度の角度でＣＩＥｘ，ＣＩＥｙの値が大きくなっている。これはこの角度範囲で黄色いリングができていることを示す。青色ＬＥＤチップと黄色蛍光体とを組み合わせた発光素子の光をレンズで集光すると、一般にこのような黄色いリングができる。
なお、ＣＩＥｘ，ＣＩＥｙの値が０（ゼロ）になっているのは、その方向に光が全く伝播してきていないことを示している。 The simulation results under the above conditions are shown in FIGS.
As shown in FIG. 15, the three light emitting devices 2A, 2C, and B all condense light to the front.
16 and 17 show chromaticity for each angle, and the horizontal axis represents the angle from the optical axis.
As shown in FIGS. 16 and 17, in the light emitting device 2 X, the values of CIEx and CIEy increase at an angle of 15 to 20 degrees. This indicates that a yellow ring is formed in this angular range. In general, such a yellow ring can be formed by collecting light from a light-emitting element in which a blue LED chip and a yellow phosphor are combined with a lens.
Note that the values of CIEx and CIEy being 0 (zero) indicate that no light has propagated in that direction.

これに対し、発光装置２Ａ，２Ｃでは、０〜７０度の角度で色度がほぼ一定であり、色ずれが生じていないことがわかる。光取り出し効率は、発光装置２Ｘで８１．１％、発光装置２Ａで９０．５％、発光装置２Ｃで９２．１％となり、発光装置２Ａ，２Ｃの光取り出し効率は高い。
なお、第２，第４の実施形態にかかる発光装置２Ｂ，２Ｄ，２Ｅも、基本的に光線経路が発光装置２Ａ，２Ｃと変わらないため、発光装置２Ｂ，２Ｄ，２Ｅにおけるシミュレーション結果は発光装置２Ａ，２Ｃにおける結果とほとんど変わらない。
以上のシミュレーション結果から、本発明の好ましい実施形態にかかる発光装置２Ａ〜２Ｅでは、色ずれが起きにくく、光取り出し効率が高いということがわかる。 On the other hand, in the light emitting devices 2A and 2C, it can be seen that the chromaticity is substantially constant at an angle of 0 to 70 degrees, and no color shift occurs. The light extraction efficiency is 81.1% for the light emitting device 2X, 90.5% for the light emitting device 2A, and 92.1% for the light emitting device 2C. The light extraction efficiency of the light emitting devices 2A and 2C is high.
Note that the light-emitting devices 2B, 2D, and 2E according to the second and fourth embodiments also basically have the same light beam path as the light-emitting devices 2A and 2C. Therefore, the simulation results of the light-emitting devices 2B, 2D, and 2E are the light-emitting devices. It is almost the same as the result in 2A and 2C.
From the above simulation results, it can be seen that in the light emitting devices 2A to 2E according to the preferred embodiments of the present invention, color misregistration hardly occurs and the light extraction efficiency is high.

ＰＡ光軸
２Ａ，２Ｂ，２Ｃ，２Ｄ，２Ｅ発光装置
２Ｘ発光装置（比較例）
４実装基板
５発光素子
６ＬＥＤチップ
８波長変換素子
８ａガラス基板
８ｂセラミック層
９空気層
１０（第１の）導光部材
１２内周面
１４孔部
１６外周面
２０（第２の）導光部材
２２底部
２４空間部
２６反射面
２８反射面
３０上部
３２底部
３４凹部
３６孔部
４０突起部
４２反射面
５０反射膜
５２反射部材
５４反射面
６０（第３の）導光部材
６２底部
６４，６６反射面
６８空気層
７０（第４の）導光部材
７２底部
７４，７６反射面
７８空気層
８０単レンズ PA optical axis 2A, 2B, 2C, 2D, 2E Light emitting device 2X Light emitting device (comparative example)
4 mounting substrate 5 light emitting element 6 LED chip 8 wavelength conversion element 8a glass substrate 8b ceramic layer 9 air layer 10 (first) light guide member 12 inner peripheral surface 14 hole 16 outer peripheral surface 20 (second) light guide member 22 bottom portion 24 space portion 26 reflecting surface 28 reflecting surface 30 upper portion 32 bottom portion 34 recessed portion 36 hole portion 40 projecting portion 42 reflecting surface 50 reflecting film 52 reflecting member 54 reflecting surface 60 (third) light guide member 62 bottom portions 64 and 66 reflecting Surface 68 Air layer 70 (Fourth) light guide member 72 Bottom 74, 76 Reflecting surface 78 Air layer 80 Single lens

Claims

A light emitting element that emits light radially;
A first light that guides a part of the outer light having a large angle with the optical axis, with the light beam emitted from the central portion of the light emitting element as the optical axis among the light emitted from the light emitting element. A light guide member;
A first reflecting surface that reflects a portion of the light emitted from the light emitting element and having a small angle with the optical axis;
A second reflecting surface for further reflecting the light reflected by the first reflecting surface;
A light emitting device comprising:

The light-emitting device according to claim 1.
The angle formed between the light axis emitted from the light emitting element and incident on the first reflecting surface and the optical axis is α, and the light beam reflected on the first reflecting surface is formed between the optical axis. A light emitting device satisfying both of the expressions (1) and (2), where β is an angle and γ is an angle formed between a light beam reflected by the second reflecting surface and an optical axis. .
α <β (1)
γ <β (2)

The light emitting device according to claim 1 or 2,
The light emitting device, wherein the first reflecting surface is disposed at a height that is half or less of a height of the second reflecting surface.

In the light-emitting device as described in any one of Claims 1-3,
The light emitting device, wherein the second reflecting surface is a curved surface.

In the light-emitting device as described in any one of Claims 1-4,
A second light guide member for guiding a part of the light on the inner side having a small angle with the optical axis;
The light emitting device, wherein the second light guide member includes the first reflection surface and the second reflection surface.

In the light-emitting device as described in any one of Claims 1-4,
A second light guide member for guiding a part of the light on the inner side having a small angle with the optical axis;
The first reflecting surface is formed on a part of the first light guide member,
The light emitting device, wherein the second light guide member has the second reflecting surface formed thereon.

The light-emitting device according to claim 5 or 6,
The light reflected by the first reflecting surface is emitted outside the second light guide member without receiving a reflecting action except for the second reflecting surface.

In the light-emitting device as described in any one of Claims 1-4,
A reflection member that reflects a part of the light on the inner side having a small angle with the optical axis;
The reflective member is formed with the first reflective surface,
The light emitting device according to claim 1, wherein the second light-reflecting surface is formed on the first light guide member.

In the light-emitting device as described in any one of Claims 1-4,
The light emitting device, wherein the first light guide member is formed with the first reflection surface and the second reflection surface.

The light-emitting device according to claim 8 or 9,
The light emitting device, wherein the second reflecting surface is made of a metal thin film or a dielectric multilayer film.

In the light-emitting device as described in any one of Claims 1-4,
A plurality of light guide members for guiding a part of the light on the inner side having a small angle with the optical axis;
If these light guide members are the second to nth light guide members in the order in which the light acts (n represents an integer of 3 or more), the second to nth light guide members are nested. Arranged,
The light emitting device, wherein the second to nth light guide members are formed with the first reflection surface and the second reflection surface, respectively.

The light-emitting device according to claim 11.
The m-th light guide member (m ≦ n, m represents an integer between 3 and n) is one near the optical axis among the light transmitted through the (m−1) -th light guide member. A light emitting device characterized by acting on the light of the part.

The light-emitting device according to claim 11 or 12,
The light reflected by the first reflecting surface in the second to nth light guide members is not subjected to a reflecting action except for the second reflecting surface, and the second to nth light guides. A light-emitting device that emits light outside a member.