JP2004335524A

JP2004335524A - Light emitting diode

Info

Publication number: JP2004335524A
Application number: JP2003125078A
Authority: JP
Inventors: Yuji Azuma; 祐二我妻
Original assignee: Harison Toshiba Lighting Corp
Current assignee: Toshiba Lighting and Technology Corp
Priority date: 2003-04-30
Filing date: 2003-04-30
Publication date: 2004-11-25

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting diode that can be adjusted in the angle of luminous intensity distribution without increasing its thickness. <P>SOLUTION: This light emitting diode is constituted by covering the upper part of a light emitting element 14 with a first transparent member 18 and forming a first air space 19 between the transparent member 18 and a base substrate 11. Then the upper part of the first transparent member 18 is covered with a second transparent member 21, and the projecting section 20 of the first transparent member 18 is fitted in the recessed section 22 of the second transparent member 21. At the same time, a second air space 23 is formed of the recess 24 of the second transparent member 21 between the first and second transparent members 18 and 21. In addition, annular convex lenses 25 are formed on one side of the second transparent member 21 opposite to the first transparent member 18 for adjusting the angle of luminous intensity distribution. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【０００１】
【発明の属する技術分野】
本発明は、照明装置などに用いる発光ダイオードに関するものである。
【０００２】
【従来の技術】
一般に、チップ型の発光ダイオードは、携帯電話や小型電子機器の液晶表示部のバックライト光源や各種の照明装置の光源として広く利用されている。図５は従来の発光ダイオードの側面図である。ベース基板１１と反射部材２８とは白色の樹脂で一体的に形成され、ベース基板１１の左右両側に金属製リードフレーム１２ａ、１２ｂを設け、一方のリードフレーム１２ａに形成される第１電極部１３ａに発光素子１４を搭載し、他方のリードフレーム１２ｂに形成される第２電極部１３ｂに金属製ワイヤ１５で接続する。そして、この金属製ワイヤおよび発光素子１４の上部を透明の樹脂製パッケージで被覆する。
【０００３】
このように、ベース基板１１上に配置された金属製リードフレーム１２ａの第１電極部１３ａに半導体チップである発光素子１４を配設し、この発光素子１４を透明な樹脂１６で充填して樹脂製パッケージ内に発光素子１４を封止して発光ダイオードを形成していた。また、配光角を小さくする場合には、図６に示すように透明樹脂１５の前面に凸レンズ１７を配設し、発光素子１４からの光線を前面の凸レンズ１７で屈折させて配光角の調整を行っていた。
【０００４】
【発明が解決しようとする課題】
しかし、凸レンズ１７で集光させる場合などでは、発光素子１４と凸レンズ１７との間の距離が凸レンズ１７のＲ面の半径以上必要となることから、厚みが増すと言った問題がある。
【０００５】
本発明の目的は、発光ダイオードの厚みを増加させることなく配光角を調整できる発光ダイオードを提供することである。
【０００６】
【課題を解決するための手段】
請求項１の発明に係わる発光ダイオードは、電極部が形成されたベース基板上に設置された発光素子と；前記発光素子の上部を被覆し前記ベース基板との間に第１空気層を形成し前記発光素子に対面する反対側に凸部を有した第１透明部材と；前記第１透明部材に対面する側に前記第１透明部材の凸部に嵌合する凹部と前記第１透明部材との間に第２空気層を形成する凹部とが複合された面を有した第２透明部材と；前記第２透明部材の前記第１透明部材に対面する反対側に形成された円環状の凸レンズと；を備えたことを特徴とする。
【０００７】
本発明及び以下の発明において、特に指定しない限り用語の定義及び技術的意味は以下による。
【０００８】
ベース基板は白色の樹脂で反射部材と一体的に形成され、電極部はリードフレームと一体的に形成される。そして、白色樹脂とリードフレームとは一体モールド化される。発光素子は半導体チップであり、電極部から電源が供給されたときに発光する素子である。
【０００９】
第１透明部材は、透明樹脂で形成され発光素子の上部を被覆し、ベース基板との間に第１空気層を形成する。また、発光素子に対面する反対側には凸部を有している。第２透明部材は、透明樹脂で形成され第１透明部材に対面する側に第１透明部材の凸部に嵌合する凹部を有すると共に、第１透明部材との間に第２空気層を形成する凹部とを有する。また、第２透明部材の第１透明部材に対面する反対側には円環状の凸レンズが形成され、この円環状凸レンズで光線を集光し外部に外部に光線を出射する。
【００１０】
従って、第１透明部材と第２透明部材とが接触する境界面は、第１透明部材の凸部と第２透明部材の凹部との嵌合部分と、第２空気槽が形成された部分とを有した複合面となる。発光素子からの光線は第１透明部材と第２透明部材とが接触する境界面に入射され、その境界面の第２空気層の底部に当たった光線は全反射して第１空気層に入射され、第１空気層でさらに全反射して第１透明部材と第２透明部材とが接触する境界面に入射される。一方、第１透明部材と第２透明部材とが接触する境界面の第１透明部材の凸部と第２透明部材の凹部との嵌合部分に当たった光線は、その嵌合部を通過して第２透明部材に入り、第２空気層の傾斜面で全反射し円環状凸レンズで集光されて外部に出射される。
【００１１】
本発明によれば、全反射を利用していることから反射のロスは小さく、また配光角を調整するには、前面の円環状凸レンズの曲率半径を変化させるか第２空気層を作る凹部の傾斜角を変化させることで可能であるので、発光素子からの光線を減衰させることなく、また、発光ダイオードの厚みを増加させることなく配光角を容易に調整できる発光ダイオードを提供できる。
【００１２】
請求項２の発明に係わる発光ダイオードは、請求項１の発明において、前記第１空気層および前記第２空気層に代えて屈折率１以上１．４５未満の低屈折率材料層を配設し、前記第１透明部材および前記第２透明部材を屈折率１．４５以上２未満の高屈折率材料層で一体的に形成したことを特徴とする。
【００１３】
本発明は、第１空気層および第２空気層に代えて屈折率１以上１．４５未満の低屈折率材料層を配設し、第１透明部材および第２透明部材を屈折率１．４５以上２未満の高屈折率材料層で一体的に形成したものである。
【００１４】
本発明によれば、高屈折率材料層の内部に屈折率１以上１．４５未満の傾斜を持った低屈折率材料層を含ませるので、高屈折率材料層２７は一体的に形成され重なる部分がないので、請求項１の発明の効果に加え、さらに光線の出射効率が向上する。
【００１５】
【発明の実施の形態】
以下、本発明の実施の形態を説明する。図１は本発明の第１の実施の形態に係わる発光ダイオードの説明図であり、図１（ａ）は平面図、図１（ｂ）は側面図である。ベース基板１１と反射部材２８とは白色の樹脂で一体的に形成され、ベース基板１１の左右両側に金属製リードフレーム１２ａ、１２ｂが取り付けられる。そして、一方のリードフレーム１２ａに形成される第１電極部１３ａに発光素子１４が搭載して接続され、他方のリードフレーム１２ｂに形成される第２電極部１３ｂと金属製ワイヤ１５で接続される。これにより、発光素子１４に電源が供給されるようにしている。
【００１６】
発光素子１４の上部は第１透明部材１８で被覆される。その際に、第１透明部材１８とベース基板１１（リードフレーム１２）との間に第１空気層１９を形成する。また、第１透明部材１８の発光素子１４に対面する反対側には凸部２０が形成されている。さらに、この第１透明部材１８の上部は第２透明部材２１が被覆される。第２透明部材２１の第１透明部材１８に対面する側には、第１透明部材１８の凸部２０に嵌合する凹部２２が設けられ、また、第２透明部材２１と第１透明部材１８との間に第２空気層２３を形成するための凹部２４が設けられている。一方、第２透明部材２１の第１透明部材１８に対面する反対側には円環状凸レンズ２５が設けられている。この円環状凸レンズ２５は集光性を増すために設けられている。
【００１７】
このように、点光源である発光素子１４の周囲に第１空気層１９を設け、また、第１空気層１９の反対側に円環状の突起（凸部２０）をある間隔で配置した第１透明部材１８を配設し、その第１透明部材１８の突起（凸部２０）と同じ形状の凹部２２および第２空気層２３を形成する凹部２４とを有した第２透明部材２１を重ねていき、第１透明部材１８の凸部２０と第２透明部材２１の凹部２２とを嵌合させると共に、第２空気層２３を形成する。
【００１８】
従って、第１透明部材１８と第２透明部材２１とが接触する境界面は、第１透明部材１８の凸部２０と第２透明部材２１の凹部２２との嵌合部分と、第２空気層２３が形成された部分との複合面となる。また、第２透明部材２１の出光側には配光角を調整するための円環状凸レンズ２５が設けられている。
【００１９】
図２は、第１の実施の形態における発光素子１４からの光線が円環状凸レンズ２５からどのように出射されるかを示した光線追跡図である。光線は大きく分けて２つの動きをする。まず、一つ目は、発光素子１４からの光線が第２空気層２３の底部に当たった場合であり、この場合には光線は第２空気層２３で全反射することになり、発光素子１４側の面に向く光線となる。そして、発光素子１４側の第１空気層１９でも全反射することになり、この反射光が再度第２空気層２３に当たれば同じことを繰り返す。
【００２０】
次に、２つ目は凸部２０と凹部２２とが重なり合った部分に光線があたる場合であり、この場合には、その部分からの光線が前面の第２透明部材２１に入り込み、第２空気層２３を作る傾斜の部分に当たって全反射することになり、全反射した光は円環状凸レンズ２５を通って外部に出射する。なお、円環状凸レンズ２５は集光性を増すために利用している。
【００２１】
第１の実施の形態によれば、発光素子１４からの光線は第１の空気層１９および第２の空気層２３での全反射を利用し、最終的に円環状凸レンズ２５で集光して外部に光線を出射するようにしているので、全体として反射のロスが小さい。また、配光角を調整するには、前面の円環状凸レンズ２５の曲率半径を変化させるか第２空気層２３を形成する凹部２４の傾斜角を変化させることで可能になるので容易に配光角を調整できる。
次に、本発明の第２の実施の形態を説明する。図３は本発明の第２の実施の形態に係わる発光ダイオードの説明図であり、図３（ａ）は平面図、図３（ｂ）は側面図である。この第２の実施の形態は、図１に示した第１の実施の形態に対し、第１空気層１９および第２空気層２３に代えて屈折率１以上１．４５未満の低屈折率材料層２６ａ、２６ｂを配設し、第１透明部材１８および第２透明部材２１を屈折率１．４５以上２未満の高屈折率材料層２７で一体的に形成したものである。図１に示し第１の実施の形態と同一要素には同一符号を付し重複する説明は省略する。
【００２２】
図３において、ベース基材１１のリードフレーム１２ａの第１電極部１３ａに配置された発光素子１４の周囲に、第１空気層１９に代えて低屈折率材料層２６ａを形成し、その上部に高屈折率材料層２７を形成する。高屈折材料層２７は、高屈折率材料の中に低屈折率材料を埋め込んで、高屈折率材料層２７の内部に低屈折率材料層２６ｂを形成し、第１透明部材１８および第２透明部材２１を一体的に形成している。低屈折率材料層２６ａ、２６ｂは、屈折率が１以上で１．４５未満の低屈折率材料を使用し、高屈折率材料層２７としては屈折率１．４５以上２未満の高屈折率材料を使用する。
【００２３】
図４は、第２の実施の形態における発光素子１４からの光線が円環状凸レンズ２５からどのように出射されるかを示した光線追跡図である。第１の実施の形態の場合と同様に、光線は大きく分けて２つの動きをする。まず、一つ目は、発光素子１４からの光線が低屈折率材料層２６ｂの底部に当たった場合であり、この場合には光線は低屈折率材料層２６ｂで全反射することになり、発光素子１４側の面に向く光線となる。そして、発光素子１４側の低屈折率材料層２６ａでも全反射することになり、この反射光が、再度低屈折率材料層２６ｂに当たれば同じことを繰り返す。次に、２つ目は、低屈折率材料層２６ｂの傾斜面部に光線があたる場合で、この場合には、低屈折率材料層２６ｂを作る傾斜面部に当たって全反射することになり、全反射した光は円環状凸レンズ２５を通って外部に出射する。
【００２４】
図４では、高屈折率材料層２７は一体的に形成されており重なる部分がないことから、この重なり部分のロスがなくなり効率はさらに向上する。この場合にも配光角を調整するには、前面の円環状凸レンズ２５の曲率半径を変化させるか埋め込んだ低屈折率材料層２６ｂの傾斜角を変化させることで可能になる。
【００２５】
第２の実施の形態によれば、発光素子１４からの光線は低屈折率材料層２６ａ、２６ｂでの全反射を利用し、最終的に円環状凸レンズ２５で集光して外部に光線を出射するようにしているので全体として反射のロスが小さい。また、高屈折率材料層２７は一体的に形成されており重なる部分がないことから、効率はさらに良くなる。また、配光角を調整するには、前面の円環状凸レンズ２５の曲率半径を変化させるか低屈折率材料層２６ｂを形成する凹部２４の傾斜角を変化させることで可能になるので容易に配光角を調整できる。
【００２６】
【発明の効果】
以上述べたように、請求項１の発明によれば、全反射を利用していることから反射のロスは小さく、また配光角を調整するには、前面の円環状凸レンズの曲率半径を変化させるか第２空気層を作る凹部の傾斜角を変化させることで可能であるので、発光素子からの光線を減衰させることなく、また、発光ダイオードの厚みを増加させることなく配光角を容易に調整できる発光ダイオードを提供できる。
【００２７】
また、請求項２の発明によれば、高屈折率材料層の内部に屈折率１以上１．４５未満の傾斜を持った低屈折率材料層を含ませるので、高屈折率材料層２７は一体的に形成され重なる部分がないので、請求項１の発明の効果に加え、さらに光線の出射効率が向上する。
【図面の簡単な説明】
【図１】本発明の第１の実施の形態に係わる発光ダイオードの説明図。
【図２】本発明の第１の実施の形態における発光素子からの光線が円環状凸レンズからどのように出射されるかを示した光線追跡図。
【図３】本発明の第２の実施の形態に係わる発光ダイオードの説明図。
【図４】本発明の第２の実施の形態における発光素子からの光線が円環状凸レンズからどのように出射されるかを示した光線追跡図。
【図５】従来の発光ダイオードの側面図。
【図６】従来の凸レンズを有した発光ダイオードの側面図。
【符号の説明】
１１…ベース基板、１２ａ…金属製リードフレーム、１３ａ…第１電極部、１３ｂ…第２電極部、１４…発光素子、１５…金属製ワイヤ、１６…透明樹脂、１７…凸レンズ、１８…第１透明部材、１９…第１空気層、２０…凸部、２１…第２透明部材、２２…凹部、２３…第２空気層、２４…凹部、２５…円環状凸レンズ、２６…低屈折率材料層、２７…高屈折率材料層、２８…反射部材[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a light emitting diode used for a lighting device and the like.
[0002]
[Prior art]
2. Description of the Related Art In general, chip-type light emitting diodes are widely used as backlight light sources for liquid crystal display units of mobile phones and small electronic devices and light sources of various lighting devices. FIG. 5 is a side view of a conventional light emitting diode. The base substrate 11 and the reflection member 28 are integrally formed of a white resin, metal lead frames 12a and 12b are provided on both left and right sides of the base substrate 11, and a first electrode portion 13a formed on one of the lead frames 12a. The light emitting element 14 is mounted on the second lead frame 12b, and is connected to the second electrode portion 13b formed on the other lead frame 12b by the metal wire 15. Then, the metal wire and the upper part of the light emitting element 14 are covered with a transparent resin package.
[0003]
As described above, the light emitting element 14 which is a semiconductor chip is disposed on the first electrode portion 13a of the metal lead frame 12a disposed on the base substrate 11, and the light emitting element 14 is filled with the transparent resin 16 to form a resin. The light emitting element 14 is sealed in a package made of a light emitting diode. When the light distribution angle is reduced, a convex lens 17 is provided on the front surface of the transparent resin 15 as shown in FIG. 6, and the light from the light emitting element 14 is refracted by the convex lens 17 on the front surface to reduce the light distribution angle. Adjustments were being made.
[0004]
[Problems to be solved by the invention]
However, when the light is condensed by the convex lens 17 or the like, the distance between the light emitting element 14 and the convex lens 17 needs to be equal to or greater than the radius of the R surface of the convex lens 17.
[0005]
An object of the present invention is to provide a light emitting diode that can adjust a light distribution angle without increasing the thickness of the light emitting diode.
[0006]
[Means for Solving the Problems]
A light emitting diode according to the first aspect of the present invention includes a light emitting device disposed on a base substrate on which an electrode portion is formed; and forming a first air layer between the light emitting device and an upper portion of the light emitting device and the base substrate. A first transparent member having a convex portion on the opposite side facing the light emitting element; a concave portion fitted to the convex portion of the first transparent member on a side facing the first transparent member; and the first transparent member; A second transparent member having a surface in which a concave portion forming a second air layer is interposed therebetween; and an annular convex lens formed on a side of the second transparent member opposite to the first transparent member. And;
[0007]
In the present invention and the following inventions, definitions and technical meanings of terms are as follows unless otherwise specified.
[0008]
The base substrate is formed integrally with the reflection member using white resin, and the electrode portion is formed integrally with the lead frame. Then, the white resin and the lead frame are integrally molded. The light emitting element is a semiconductor chip, which emits light when power is supplied from the electrode portion.
[0009]
The first transparent member is formed of a transparent resin, covers an upper part of the light emitting element, and forms a first air layer between the first transparent member and the base substrate. Further, a convex portion is provided on the opposite side facing the light emitting element. The second transparent member is formed of a transparent resin, has a concave portion on the side facing the first transparent member, the concave portion being fitted to the convex portion of the first transparent member, and forms a second air space between the second transparent member and the first transparent member. And a concave portion. Further, an annular convex lens is formed on the opposite side of the second transparent member facing the first transparent member. The annular convex lens collects light rays and emits light rays to the outside.
[0010]
Therefore, the boundary surface where the first transparent member and the second transparent member are in contact with each other includes a fitting portion between the convex portion of the first transparent member and the concave portion of the second transparent member, and a portion where the second air tank is formed. Is obtained. Light rays from the light emitting element are incident on a boundary surface where the first transparent member and the second transparent member are in contact with each other, and light rays hitting the bottom of the second air layer at the boundary surface are totally reflected and incident on the first air layer. Then, the light is further totally reflected by the first air layer and is incident on a boundary surface where the first transparent member and the second transparent member come into contact with each other. On the other hand, a light beam hitting a fitting portion between the convex portion of the first transparent member and the concave portion of the second transparent member at the boundary surface where the first transparent member and the second transparent member come into contact passes through the fitting portion. And enters the second transparent member, is totally reflected by the inclined surface of the second air layer, is condensed by the annular convex lens, and is emitted to the outside.
[0011]
According to the present invention, since the total reflection is used, the reflection loss is small, and in order to adjust the light distribution angle, the radius of curvature of the front annular convex lens is changed or the concave portion for forming the second air layer is formed. It is possible to provide a light-emitting diode that can easily adjust the light distribution angle without attenuating the light rays from the light-emitting element and without increasing the thickness of the light-emitting diode.
[0012]
According to a second aspect of the present invention, in the light emitting diode according to the first aspect, a low refractive index material layer having a refractive index of 1 or more and less than 1.45 is provided in place of the first air layer and the second air layer. The first transparent member and the second transparent member are integrally formed of a high refractive index material layer having a refractive index of 1.45 or more and less than 2.
[0013]
According to the present invention, a low refractive index material layer having a refractive index of 1 or more and less than 1.45 is provided in place of the first air layer and the second air layer, and the first transparent member and the second transparent member are provided with a refractive index of 1.45. More than two and less than two high refractive index material layers are integrally formed.
[0014]
According to the present invention, the high-refractive-index material layer 27 is formed integrally and overlaps because the low-refractive-index material layer having a gradient of 1 or more and less than 1.45 is included in the high-refractive-index material layer. Since there is no portion, in addition to the effect of the first aspect, the light emission efficiency is further improved.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described. FIG. 1 is an explanatory view of a light emitting diode according to a first embodiment of the present invention. FIG. 1 (a) is a plan view and FIG. 1 (b) is a side view. The base substrate 11 and the reflection member 28 are integrally formed of a white resin, and metal lead frames 12 a and 12 b are attached to both left and right sides of the base substrate 11. The light emitting element 14 is mounted and connected to the first electrode portion 13a formed on one lead frame 12a, and is connected to the second electrode portion 13b formed on the other lead frame 12b by the metal wire 15. . Thus, power is supplied to the light emitting element 14.
[0016]
The upper part of the light emitting element 14 is covered with the first transparent member 18. At this time, a first air layer 19 is formed between the first transparent member 18 and the base substrate 11 (lead frame 12). Further, a projection 20 is formed on the opposite side of the first transparent member 18 facing the light emitting element 14. Further, the upper part of the first transparent member 18 is covered with a second transparent member 21. On the side of the second transparent member 21 facing the first transparent member 18, there is provided a concave portion 22 that fits into the convex portion 20 of the first transparent member 18, and the second transparent member 21 and the first transparent member 18 are provided. A concave portion 24 for forming the second air layer 23 is provided between the first and second air layers. On the other hand, an annular convex lens 25 is provided on the opposite side of the second transparent member 21 facing the first transparent member 18. The annular convex lens 25 is provided to increase the light collecting property.
[0017]
As described above, the first air layer 19 is provided around the light emitting element 14 which is a point light source, and the annular projections (projections 20) are arranged at a certain interval on the opposite side of the first air layer 19. The transparent member 18 is provided, and the second transparent member 21 having the concave portion 22 having the same shape as the projection (convex portion 20) of the first transparent member 18 and the concave portion 24 forming the second air layer 23 is overlapped. Then, the convex portion 20 of the first transparent member 18 and the concave portion 22 of the second transparent member 21 are fitted together, and the second air layer 23 is formed.
[0018]
Therefore, the boundary surface where the first transparent member 18 and the second transparent member 21 come into contact with each other is formed by the fitting portion between the convex portion 20 of the first transparent member 18 and the concave portion 22 of the second transparent member 21 and the second air space. It becomes a composite surface with the portion where 23 is formed. An annular convex lens 25 for adjusting the light distribution angle is provided on the light exit side of the second transparent member 21.
[0019]
FIG. 2 is a ray tracing diagram showing how rays from the light emitting element 14 are emitted from the annular convex lens 25 in the first embodiment. Light rays make two major movements. First, the light beam from the light emitting element 14 strikes the bottom of the second air layer 23. In this case, the light ray is totally reflected by the second air layer 23, It is a light ray directed to the side surface. Then, the first air layer 19 on the light emitting element 14 side is also totally reflected, and the same is repeated when the reflected light hits the second air layer 23 again.
[0020]
Next, the second is a case where a light beam hits a portion where the convex portion 20 and the concave portion 22 overlap. In this case, the light beam from that portion enters the second transparent member 21 on the front surface and the second air The light is totally reflected upon hitting the inclined portion forming the layer 23, and the totally reflected light is emitted to the outside through the annular convex lens 25. In addition, the annular convex lens 25 is used to increase the light collecting property.
[0021]
According to the first embodiment, the light rays from the light emitting element 14 are ultimately condensed by the annular convex lens 25 using the total reflection in the first air layer 19 and the second air layer 23. Since the light beam is emitted to the outside, the reflection loss is small as a whole. Further, the light distribution angle can be adjusted by changing the radius of curvature of the annular convex lens 25 on the front surface or by changing the inclination angle of the concave portion 24 forming the second air layer 23. The angle can be adjusted.
Next, a second embodiment of the present invention will be described. FIG. 3 is an explanatory view of a light emitting diode according to a second embodiment of the present invention. FIG. 3 (a) is a plan view and FIG. 3 (b) is a side view. This second embodiment is different from the first embodiment shown in FIG. 1 in that a low refractive index material having a refractive index of 1 or more and less than 1.45 is used instead of the first air layer 19 and the second air layer 23. The layers 26a and 26b are provided, and the first transparent member 18 and the second transparent member 21 are integrally formed of a high refractive index material layer 27 having a refractive index of 1.45 or more and less than 2. The same elements as those shown in FIG. 1 and the first embodiment are denoted by the same reference numerals, and redundant description is omitted.
[0022]
In FIG. 3, a low-refractive-index material layer 26a is formed instead of the first air layer 19 around the light emitting element 14 arranged on the first electrode portion 13a of the lead frame 12a of the base substrate 11, and on the upper portion thereof. The high refractive index material layer 27 is formed. The high-refractive-index material layer 27 embeds a low-refractive-index material in a high-refractive-index material, forms a low-refractive-index material layer 26b inside the high-refractive-index material layer 27, and forms the first transparent member 18 and the second transparent member. The member 21 is formed integrally. The low refractive index material layers 26a and 26b use a low refractive index material having a refractive index of 1 or more and less than 1.45, and the high refractive index material layer 27 has a high refractive index material having a refractive index of 1.45 or more and less than 2. Use
[0023]
FIG. 4 is a ray tracing diagram showing how rays from the light emitting element 14 are emitted from the annular convex lens 25 in the second embodiment. As in the case of the first embodiment, the light beam roughly divides into two movements. First, the light beam from the light emitting element 14 hits the bottom of the low-refractive-index material layer 26b. In this case, the light beam is totally reflected by the low-refractive-index material layer 26b. The light is directed toward the surface on the element 14 side. Then, the low-refractive-index material layer 26a on the side of the light-emitting element 14 is also totally reflected. When the reflected light hits the low-refractive-index material layer 26b again, the same is repeated. Next, in the second case, a light beam hits the inclined surface of the low refractive index material layer 26b. In this case, the light impinges on the inclined surface forming the low refractive index material layer 26b, and the light is totally reflected. The light exits through the annular convex lens 25 to the outside.
[0024]
In FIG. 4, since the high-refractive-index material layer 27 is formed integrally and has no overlapping portion, there is no loss in the overlapping portion, and the efficiency is further improved. Also in this case, the light distribution angle can be adjusted by changing the radius of curvature of the front annular convex lens 25 or by changing the inclination angle of the embedded low refractive index material layer 26b.
[0025]
According to the second embodiment, the light beam from the light emitting element 14 utilizes the total reflection in the low refractive index material layers 26a and 26b and is finally condensed by the annular convex lens 25 and emitted to the outside. The reflection loss is small as a whole. Further, since the high refractive index material layer 27 is formed integrally and has no overlapping portion, the efficiency is further improved. The light distribution angle can be easily adjusted by changing the radius of curvature of the front annular convex lens 25 or by changing the inclination angle of the concave portion 24 forming the low refractive index material layer 26b. The light angle can be adjusted.
[0026]
【The invention's effect】
As described above, according to the first aspect of the present invention, since the total reflection is used, the reflection loss is small, and in order to adjust the light distribution angle, the radius of curvature of the front annular convex lens is changed. Or by changing the inclination angle of the concave portion forming the second air layer, the light distribution angle can be easily adjusted without attenuating the light rays from the light emitting element and without increasing the thickness of the light emitting diode. An adjustable light emitting diode can be provided.
[0027]
According to the second aspect of the present invention, the high refractive index material layer 27 includes the low refractive index material layer having a gradient of 1 or more and less than 1.45 inside the high refractive index material layer. Since there is no overlapping part, the light emitting efficiency is further improved in addition to the effect of the first aspect of the present invention.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram of a light emitting diode according to a first embodiment of the present invention.
FIG. 2 is a ray tracing diagram showing how a ray from a light emitting element is emitted from an annular convex lens according to the first embodiment of the present invention.
FIG. 3 is an explanatory diagram of a light emitting diode according to a second embodiment of the present invention.
FIG. 4 is a ray tracing diagram showing how rays from a light emitting element are emitted from an annular convex lens according to a second embodiment of the present invention.
FIG. 5 is a side view of a conventional light emitting diode.
FIG. 6 is a side view of a light emitting diode having a conventional convex lens.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Base board, 12a ... Metal lead frame, 13a ... 1st electrode part, 13b ... 2nd electrode part, 14 ... Light emitting element, 15 ... Metal wire, 16 ... Transparent resin, 17 ... Convex lens, 18 ... 1st Transparent member, 19: first air layer, 20: convex portion, 21: second transparent member, 22: concave portion, 23: second air layer, 24: concave portion, 25: annular convex lens, 26: low refractive index material layer , 27: High refractive index material layer, 28: Reflecting member

Claims

A light emitting device installed on a base substrate on which an electrode unit is formed;
A first transparent member which covers an upper portion of the light emitting element, forms a first air layer between the light emitting element and the base substrate, and has a convex portion on a side opposite to the light emitting element;
On the side facing the first transparent member, there was provided a combined surface of a concave portion fitted to the convex portion of the first transparent member and a concave portion forming a second air layer between the first transparent member. A second transparent member;
An annular convex lens formed on the opposite side of the second transparent member facing the first transparent member;
A light emitting diode comprising:

A low refractive index material layer having a refractive index of 1 or more and less than 1.45 is provided in place of the first air layer and the second air layer, and the first transparent member and the second transparent member are provided with a refractive index of 1.45. 2. The light-emitting diode according to claim 1, wherein the light-emitting diode is formed integrally with at least two high refractive index material layers.