201038976 六、發明說明： 【發明所屬之技術領域】 - 本發明涉及一種聚光型透鏡，尤其涉及一種菲涅爾 透鏡。 【先前技術】 菲涅爾透鏡是一種平面“凸透鏡”，在許多應用領域 取代了凸透鏡，其多是由聚烯烴材料注壓而成之薄片， 也有採用很薄之玻璃製成。在透鏡之一面為光面，另一 〇 面上設有等距之齒紋，藉由這些齒紋可以達到對指定光 譜範圍之光帶通進行反射或者折射，使透過透鏡之光線 彙聚於焦點，實現凸透鏡之作用。 如圖1至圖3所示，傳統之菲涅爾透鏡10包括一入 射面11及一出射面12,所述入射面11上設有多個凸起 之齒紋13，所述齒紋13包括一垂直於入射面11之第一 表面14及一與所述第一表面14相交之第二表面15,且 所述第一表面14與第二表面15相交成朝向於入射面11 〇 之銳角。當從入射面11射入之光線A經過齒紋13之第 二表面15產生折射後，一部分光線A1將彙聚於焦點； 而另一部分光線A2將投射於同一齒紋13之第一表面14 上，由於經過第一表面14之光線A2之入射角大於臨界 角，則光線A2將會產生全反射，且反射方向呈偏離焦 點之發散狀。這將導致一部分從入射面11入射之光線無 法彙聚於焦點，從而降低聚焦光點之光照強度及亮度。 【發明内容】 4 201038976 有鑑於此，有必要括 強度和亮度之菲淫爾透鏡：、一可提高聚焦光點之光照 種菲涅爾透鏡’其包括一入射面及 所述入射面環刮·古夕 出射面’在 直於入射面之第起之齒紋，所述齒紋包括一垂 表面，且所述第一表面盥當祁又之第一 之銳角，·所述當主表相父成朝向於入射面 右上設置有多個凹槽，所述⑽且 ❹201038976 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to a concentrating lens, and more particularly to a Fresnel lens. [Prior Art] Fresnel lenses are planar "convex lenses" that have replaced convex lenses in many applications, mostly from sheets extruded from polyolefin materials or from thin glass. One side of the lens is a smooth surface, and the other side is provided with equidistant teeth, by which the light bandpass of the specified spectral range can be reflected or refracted, and the light transmitted through the lens is concentrated at the focus. Realize the role of the convex lens. As shown in FIG. 1 to FIG. 3, the conventional Fresnel lens 10 includes an incident surface 11 and an exit surface 12, and the incident surface 11 is provided with a plurality of raised ribs 13, and the ribs 13 include A first surface 14 perpendicular to the entrance face 11 and a second surface 15 intersecting the first surface 14, and the first surface 14 intersects the second surface 15 to face an acute angle of the entrance face 11 〇. When the light A incident from the incident surface 11 is refracted by the second surface 15 of the rib 13, a portion of the light A1 will converge at the focus; and another portion of the light A2 will be projected onto the first surface 14 of the same rib 13, Since the incident angle of the light A2 passing through the first surface 14 is greater than the critical angle, the light A2 will produce total reflection, and the reflection direction will be divergent from the focus. This will cause a portion of the light incident from the incident surface 11 to converge at the focus, thereby reducing the illumination intensity and brightness of the focused spot. SUMMARY OF THE INVENTION 4 201038976 In view of this, it is necessary to include a lenticular lens of intensity and brightness: a light-receiving Fresnel lens that enhances the focused spot, which includes an incident surface and the incident surface ring scraping. The ancient eve exit surface 'in the first tooth line straight to the incident surface, the tooth pattern includes a vertical surface, and the first surface is 祁 祁 祁 第一 第一 第一 第一 , , , , , Providing a plurality of grooves toward the upper right side of the incident surface, said (10) and ❹
G ==射面之光學有效面，所述光學有效面:第 之臨界角=—射於第-表面之光線 由在技術’本技術方案提供之菲埋爾透鏡藉 对ί 置多個具有朝向於出射面之光學有 之…L 與第一表面之朝向於入射面 、4又射於第一表面之光線之臨界角之兩件，r 面之光線將會經過折射後囊聚於焦二‘ 了有效提尚聚焦光點之光照強度及亮度。 【實施方式】 :面將結合附圖與實施例對本技術方案之菲淫爾透 鲵作進一步詳細說明。 如圖4及圖5所示，本發明實施方式提供之—種菲 :爾透鏡20’其採用有機玻璃製成。所述 為-圓形透鏡，其包括一入射面21及—出射二:2在0 所逃入射面21上環設有多個凸起之齒紋23，且每個齒 紋23都是環繞入射面21中心之同心圓環。在本實施方 式中，所述菲涅爾透鏡20之折射率為1>5，空氣之折射 5 201038976 率為1.0。 所述齒紋23包括—击古# 枯S直於入射面21之第一表面24 -及—與所述第—表面24相交之第二表面25，且所述第 一表面24與第二表面25才目交成朝向於入射面21之銳 角，每個第-表面24與其對應之第二表面25所形成之 銳角角度不相同。藉由調整第一表面24與第二表面％ 相交之銳角之角度，可實現對菲浬爾透鏡20焦距之調 整。所述第-表面24上設置有多個凹槽％，所述凹槽 Ο 26包括一朝向於出射φ22之光學有效面261，所述光學 1效面，261與第-表面24朝向於入射面21之夾角小於 投射於第-表面24之光線之臨界角之兩倍。所述凹槽 26在第-表面24上均勻設置^緊密排列。在本實施方 式中，可採用超精密機床對第一表面24進行切削加工， 以在第一表面24上形成多個近似錐狀之網點；也可採用 鐳射光線對第一表面24進行打點加工，以在第一表面 24上形成多個近似半圓狀之網點。 〇 當平行光線Β從菲涅爾透鏡2〇之入射面21進入 後，投射到齒紋23之第二表面25,經過第二表面乃之 折射後，一部分光線B1將直接彙聚於菲涅爾透鏡加之 焦點，另外一部分光線B2將會投射於第一表面24之凹 槽26之光學有效面261上。 根據全反射定律，„lsina = „2sin/?，其中nl為菲涅爾 透鏡2〇之折射率，α為光線B2投射於光學有效面261 上之臨界角，η2為空氣之折射率，β等於90度；當光線 Β2之入射角大於臨界角時，就會發生全反射。由於光學 6 201038976 有效面261與第一表面24朝向於入射面21之夹角小於 ' 投射於第一表面24之光線B2之臨界角之兩倍。所述光 - 線B2與光學有效面261所成入射角小於臨界角，投射 於第一表面24之光線B2將在光學有效面261產生折射 後投射於另一相鄰齒紋23之第二表面25，然後再經過 第二表面25之折射後彙聚於菲涅爾透鏡20之焦點。 本發明提供之菲涅爾透鏡藉由在其第一表面上設置 多個具有朝向於出射面之光學有效面之凹槽，且光學有 ® 效面與第一表面之朝向於入射面之夾角小於投射於第一 表面之光線之臨界角之兩倍，投射於光學有效面之光線 將會經過折射後彙聚於焦點，從而可有效提高聚焦光點 之光照強度及亮度。 綜上所述，本發明確已符合發明專利之要件，遂依 法提出專利申請。惟，以上所述者僅為本發明之較佳實 施方式，自不能以此限制本案之申請專利範圍。舉凡熟 〇 悉本案技藝之人士援依本發明之精神所作之等效修飾或 變化，皆應涵蓋於以下申請專利範圍内。 【主要元件符號說明】 菲涅爾透鏡 10、20 入射面 11、21 出射面 12、22 齒紋 13、23 14、24 第一表面 7 201038976 第二表面 15、25 凹槽 26 光學有效面 261 【圖式簡單說明】 圖1係先前技術中菲涅爾透鏡之立體示意圖。 圖2係先前技術中菲涅爾透鏡之局部剖示圖。 圖3係先前技術中菲涅爾透鏡之光學示意圖。 圖4係本發明實施方式中菲涅爾透鏡之局部剖示 圖。 圖5係圖4中菲涅爾透鏡之光學示意圖。G == optical effective surface of the plane, the optical effective surface: the critical angle = - the light incident on the first surface is obtained by the technique of the Philippine lens provided by the technical solution The optics of the exit surface are... L and the critical angle of the first surface facing the incident surface, 4 and the light incident on the first surface, the light of the r-plane will be condensed and then condensed into the focal two' Effectively enhances the light intensity and brightness of the focused spot. [Embodiment]: The present invention will be further described in detail with reference to the accompanying drawings and embodiments. As shown in FIG. 4 and FIG. 5, the phenanthrene lens 20' provided by the embodiment of the present invention is made of organic glass. The circular lens includes an incident surface 21 and an exiting second: 2, and a plurality of raised ribs 23 are arranged on the escaping incident surface 21 of the 0, and each of the ribs 23 surrounds the incident surface. 21 center concentric rings. In the present embodiment, the Fresnel lens 20 has a refractive index of 1 > 5, and the refractive index of air 5 201038976 is 1.0. The ribs 23 include a first surface 24 - which is perpendicular to the incident surface 21 - and a second surface 25 intersecting the first surface 24, and the first surface 24 and the second surface 25 is formed to be an acute angle toward the incident surface 21, and each of the first surface 24 and its corresponding second surface 25 form an acute angle different. The adjustment of the focal length of the Phillips lens 20 can be achieved by adjusting the angle of the acute angle at which the first surface 24 intersects the second surface %. The first surface 24 is provided with a plurality of grooves %, and the groove Ο 26 includes an optical effective surface 261 facing the exit φ22, the optical surface 261 and the first surface 24 facing the incident surface The angle of 21 is less than twice the critical angle of the light projected onto the first surface 24. The grooves 26 are evenly arranged on the first surface 24 to be closely arranged. In the present embodiment, the first surface 24 may be cut by an ultra-precision machine tool to form a plurality of approximately tapered mesh points on the first surface 24; the first surface 24 may also be spotted by laser light. A plurality of approximately semi-circular dots are formed on the first surface 24. When the parallel light ray enters from the incident surface 21 of the Fresnel lens 2, it is projected onto the second surface 25 of the rib 23, and after being refracted by the second surface, a part of the light B1 will directly converge on the Fresnel lens. With the focus, another portion of the light B2 will be projected onto the optically effective surface 261 of the recess 26 of the first surface 24. According to the law of total reflection, „lsina = „2sin/?, where nl is the refractive index of Fresnel lens 2〇, α is the critical angle at which ray B2 is projected on optical effective surface 261, η2 is the refractive index of air, β is equal to 90 degrees; when the incident angle of the ray Β 2 is greater than the critical angle, total reflection occurs. Since the angle between the effective surface 261 of the optical 6 201038976 and the first surface 24 toward the incident surface 21 is less than twice the critical angle of the light B2 projected on the first surface 24. The incident angle of the light-line B2 and the optical effective surface 261 is less than a critical angle, and the light B2 projected on the first surface 24 will be refracted by the optical effective surface 261 and projected onto the second surface of another adjacent rib 23 25, and then condensed through the second surface 25 to converge at the focus of the Fresnel lens 20. The Fresnel lens provided by the present invention has a plurality of grooves having an optical effective surface facing the exit surface on the first surface thereof, and the angle between the optical velocities and the first surface facing the incident surface is smaller than The light incident on the first surface is twice the critical angle, and the light projected on the optical effective surface will be refracted and concentrated in the focus, thereby effectively improving the illumination intensity and brightness of the focused spot. In summary, the present invention has indeed met the requirements of the invention patent, and has filed a patent application in accordance with the law. However, the above description is only a preferred embodiment of the present invention, and it is not possible to limit the scope of the patent application of the present invention. Equivalent modifications or variations made by persons skilled in the art in light of the spirit of the invention are intended to be included within the scope of the following claims. [Description of main component symbols] Fresnel lens 10, 20 Incidence surface 11, 21 Exit surface 12, 22 Ragged 13, 23 14, 24 First surface 7 201038976 Second surface 15, 25 Groove 26 Optical effective surface 261 [ BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a Fresnel lens in the prior art. 2 is a partial cross-sectional view of a Fresnel lens in the prior art. Figure 3 is an optical schematic of a prior art Fresnel lens. Fig. 4 is a partial cross-sectional view showing a Fresnel lens in an embodiment of the present invention. Figure 5 is an optical schematic view of the Fresnel lens of Figure 4.
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