IPC分类号：
F21V8/00 | F21S2/00 | F21Y115/10 | F21Y103/33
国民经济行业分类号：
C4350 | C3874 | C4090 | C3879
当前申请(专利权)人：
KABUSHIKI KAISHA TOSHIBA | TOSHIBA MATERIALS CO., LTD.
原始申请(专利权)人：
KABUSHIKI KAISHA TOSHIBA | TOSHIBA MATERIALS CO., LTD.
当前申请(专利权)人地址：
1-1 Shibaura 1-chome, Minato-ku Tokyo, JP | 8 Shinsugita-Cho, Isogo-Ku Yokohama-Shi Kanagawa, JP
工商成立日期：
1875-01-01|2003-10-01
发明人：
OHNO, HIROSHI | KATO, MITSUAKI | HAYASHIHARA, HIROMICHI | KONDO, HIROYASU | TSUDA, RYOJI | OOYA, YASUMASA
摘要：
An optical element according to an embodiment is formed from a material transparent to visible light and has a rotationally symmetrical shape with respect to the central axis. A cavity containing no transparent material is provided inside the optical element. The inner surface of the cavity has a shape in which a boundary line of the cavity along which a plane including the central axis intersects the inner surface includes a curve portion expanding toward the outside of the optical element. In addition, when an origin is set in the cavity, a clockwise direction around the origin along the boundary line is set as a positive direction, a first tangent vector is set at a first point on the boundary line, and a second tangent vector is set at a second point adjacent to the first point in the positive direction, an angle defined by the second tangent vector with respect to the first tangent vector with the clockwise direction being a positive direction is not less than 0°. The inner surface of the cavity does not include any surface recessed inwardly.
技术问题语段：
The technical problem addressed in this patent is how to create an LED illumination apparatus that can approximate the shape of an incandescent light bulb and shine with a wide light distribution (1/2 distribution angle: about 270°) like a clear incandescent light bulb. Additionally, the patent discusses the use of an optical element, like a wide light distribution lens, to increase the distribution angle of the LED.
技术功效语段：
The patent text is discussing the use of an optical element in an illumination apparatus. However, current optical elements result in a reduction of light output ratio because the light beams that return to the LED are absorbed. There is a need for an optical element that can efficiently cause light with a wide light distribution to emerge. The technical effect of this invention is to provide an optical element that can efficiently cause light with a wide light distribution to emerge, resulting in an improved illumination apparatus.
权利要求：
1. An optical element (10) formed from a material transparent to visible light, and including a cylindrical light guide portion (2) having one end on a light source side along a central axis, a hemispherical scattering portion (3) integrally connected to the other end of the light guide portion (2) along the central axis, wherein a cylindrical inside of the light guide portion (2) is smoothly connected to a hollow inside of the scattering portion (3) to form a cavity (1), wherein the light guide portion (2) has the same outer diameter as the scattering portion (3); charactered in that of the inner surface of the cavity (1), the inner surface of the scattering portion (3) is a diffusing surface (3a) which scatters light and wherein the inner surface of the cavity (1) except for the diffusing surface (3a) is a mirror surface; wherein an inner surface of the cavity (1) located in the scattering portion (3) has a shape in which a boundary line of the cavity (1) along which a plane including the central axis intersects the inner surface includes a curve portion expanding toward the exterior of the optical element (10), and when an origin is set in the cavity (1), a clockwise direction around the origin along the boundary line is set as a positive direction, a first tangent vector is set at a first point on the boundary line, and a second tangent vector is set at a second point adjacent to the first point in the positive direction, an angle defined by the second tangent vector with respect to the first tangent vector with the clockwise direction being a positive direction is not less than 0°.
2. The optical element (10) of claim 1, further comprising: a bottom surface located on a one end side of the central axis; and a side surface which is continuous with the bottom surface and extends along the central axis.
3. The optical element (10) of claim 2, wherein the cavity (1) has an opening communicating with the bottom surface, and the inner surface of the cavity (1) has a shape gradually expanding along the central axis toward the opening.
4. An illumination apparatus comprising: an optical element (10) defined in any one of claims 1 to 3; and a light source having a light-emitting surface, the light source being arranged such that the light-emitting surface faces a bottom surface of the optical element (10) located on the one end side of the light guide portion (2); wherein the light source comprises a plurality of light-emitting elements (11) which are annularly arranged at equal intervals in the circumferential direction of the bottom surface (21) of the optical element (10).
5. The illumination apparatus of claim 4. further comprising a substrate on which the plurality of light sources are circularly arranged, wherein the plurality of light sources are arranged on the substrate such that the light-emitting surface of each of the light sources faces the bottom surface of the optical element (10).