TWI651549B - Fresnel lens - Google Patents
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Abstract
一種菲涅耳透鏡,包括菲涅耳面。菲涅耳面包括多個使成像光線通過之菲涅耳有效面,二相鄰的菲涅耳有效面之間藉由一菲涅耳無效面互相連接。各菲涅耳無效面在包含該菲涅耳透鏡的一光軸的一截面上之一位於該菲涅耳透鏡的齒峰的一端與一位於該菲涅耳透鏡的齒谷的一端的一連接直線與一參考線夾出一拔模角。光軸與截面重合。參考線平行於光軸且通過菲涅耳有效面之位於齒峰的一端。各拔模角之角度小於90度。這些拔模角包括由光軸自徑向向外角度漸增的第一、第二、第三、第四、第五拔模角。A Fresnel lens comprising a Fresnel face. The Fresnel face includes a plurality of Fresnel effective faces through which the imaging light passes, and two adjacent Fresnel effective faces are interconnected by a Fresnel ineffective face. One of the Fresnel ineffective faces on one of the sections including an optical axis of the Fresnel lens is located at one end of the tooth peak of the Fresnel lens and a connection at one end of the valley of the Fresnel lens The straight line and a reference line clip a draft angle. The optical axis coincides with the cross section. The reference line is parallel to the optical axis and passes through the Fresnel effective surface at one end of the tooth peak. The angle of each draft angle is less than 90 degrees. These draft angles include first, second, third, fourth, and fifth draft angles that are gradually increasing from the radially outward angle of the optical axis.
Description
本發明是有關於一種透鏡,且特別是有關於一種菲涅耳透鏡。This invention relates to a lens and, more particularly, to a Fresnel lens.
在先前技術中,一般的菲涅耳透鏡的光學成像品質常因光線射至菲涅耳無效面造成反射或折射形成雜散光,使成像上出現光斑或光點而影響成像品質。而實務上以射出成形方式製作菲涅耳透鏡時,須設計一拔模角(Draft Angle)使菲涅耳透鏡與模具能夠分離。然而在習知技術中,菲涅耳透鏡的各拔模角皆相同,而導致射至菲涅耳無效面的光線皆以相同角度反射形成雜散光。這樣的設計造成雜散光集中且照度高,因此於成像面上形成明顯的光斑,成像品質與清晰度被影響而下降。故如何降低雜散光照度、提升成像整體清晰度以提高菲涅耳透鏡的光學成像品質是本領域從業人員潛心研究之課題。In the prior art, the optical imaging quality of a typical Fresnel lens is often caused by reflection or refraction of light incident on the Fresnel ineffective surface to form stray light, which causes a spot or a spot on the image to affect the image quality. In practice, when a Fresnel lens is produced by injection molding, a draft angle must be designed to separate the Fresnel lens from the mold. However, in the prior art, the draft angles of the Fresnel lenses are the same, and the rays that are incident on the Fresnel ineffective surface are reflected at the same angle to form stray light. Such a design causes stray light to concentrate and has high illuminance, so that a clear spot is formed on the image plane, and image quality and sharpness are affected and decreased. Therefore, how to reduce the stray illumination and improve the overall sharpness of the imaging to improve the optical imaging quality of the Fresnel lens is a subject of research in the field.
本發明提供一種菲涅耳透鏡,其具有良好的光學成像品質。The present invention provides a Fresnel lens that has good optical imaging quality.
本發明的一實施例的菲涅耳透鏡包括菲涅耳面。菲涅耳面包括多個使成像光線通過之菲涅耳有效面。二相鄰的菲涅耳有效面之間藉由一菲涅耳無效面互相連接。各菲涅耳無效面在包含菲涅耳透鏡的一光軸的一截面上之一位於菲涅耳透鏡的齒峰的一端與一位於菲涅耳透鏡的齒谷的一端的一連接直線與一參考線夾出一拔模角。參考線平行於光軸且通過菲涅耳有效面之位於齒峰的一端。光軸與截面重合。各拔模角之角度小於90度。這些拔模角包括一自光軸徑向向外算起為第一個的第一拔模角、一自光軸徑向向外算起為第二個的第二拔模角、一自光軸徑向向外算起為第三個的第三拔模角、一自光軸徑向向外算起為第四個的第四拔模角及一自光軸徑向向外算起為第五個的第五拔模角。第二拔模角大於第一拔模角。第三拔模角大於第二拔模角。第四拔模角大於第三拔模角。第五拔模角大於第四拔模角。A Fresnel lens according to an embodiment of the present invention includes a Fresnel surface. The Fresnel face includes a plurality of Fresnel effective faces that allow imaging light to pass through. Two adjacent Fresnel effective faces are interconnected by a Fresnel ineffective face. One of a cross section of an Fresnel ineffective plane on one of the optical axes including the Fresnel lens is located at one end of the tooth peak of the Fresnel lens and a connecting line at one end of the valley of the Fresnel lens The reference line clips a draft angle. The reference line is parallel to the optical axis and passes through the Fresnel effective surface at one end of the tooth peak. The optical axis coincides with the cross section. The angle of each draft angle is less than 90 degrees. The draft angle includes a first draft angle calculated from the optical axis radially outward as a first one, and a second draft angle calculated from the optical axis radially outward as a second, a self-light The axis is calculated radially outward as the third third draft angle, one from the optical axis radially outward as the fourth fourth draft angle and one from the optical axis radially outward. The fifth fifth draft angle. The second draft angle is greater than the first draft angle. The third draft angle is greater than the second draft angle. The fourth draft angle is greater than the third draft angle. The fifth draft angle is greater than the fourth draft angle.
基於上述,在本發明實施例的菲涅耳透鏡中,透過在菲涅爾透鏡中設置自光軸徑向向外角度漸增的拔模角,可以有效分散雜散光的照射面積且降低雜散光的照度,進而達到良好的光學成像品質。Based on the above, in the Fresnel lens of the embodiment of the present invention, by providing a draft angle which is gradually increased from the optical axis in the Fresnel lens, the irradiation area of the stray light can be effectively dispersed and the stray light can be reduced. The illuminance, in turn, achieves good optical imaging quality.
為讓本發明的上述特徵和優點能更明顯易懂,下文特舉實施例,並配合所附圖式作詳細說明如下。The above described features and advantages of the invention will be apparent from the following description.
本發明下列多個實施例的菲涅耳透鏡可適用於虛擬實境(VR, virtual reality)等頭戴式模擬立體視覺之顯示裝置,或可攜式電子裝置例如手機、相機、平板電腦、或是個人數位助理(Personal Digital Assistant, PDA)等的光學成像鏡頭,或是照明用光學透鏡。The Fresnel lens of the following embodiments of the present invention can be applied to a display device of a head-mounted analog stereo vision such as virtual reality (VR), or a portable electronic device such as a mobile phone, a camera, a tablet, or It is an optical imaging lens such as a Personal Digital Assistant (PDA) or an optical lens for illumination.
為了詳細說明下列實施例的菲涅耳透鏡的配置關係,下列實施例的菲涅耳透鏡可視為處於由X軸、Y軸以及Z軸所建構的三維空間中,此三軸X軸、Y軸以及Z軸兩兩之間互為垂直。In order to explain the configuration relationship of the Fresnel lens of the following embodiments in detail, the Fresnel lens of the following embodiment can be regarded as being in a three-dimensional space constructed by the X-axis, the Y-axis, and the Z-axis, and the three-axis X-axis and Y-axis And the Z axis is perpendicular to each other.
圖1至圖4為本發明不同實施例的菲涅耳透鏡的截面示意圖。1 to 4 are schematic cross-sectional views of a Fresnel lens according to various embodiments of the present invention.
請先參照圖1,在本實施例中,菲涅耳透鏡100具有菲涅耳面110以及相對此菲涅耳面110的表面120。在本發明的實施例中,表面120可以是平面、凹面、凸面或菲涅耳面,而在本實施例中,表面120以平面為例。圖1所示出的截面包含菲涅耳透鏡100的一光軸I,亦即,光軸I與此圖1的截面(XY平面)重合。Referring first to FIG. 1, in the present embodiment, the Fresnel lens 100 has a Fresnel surface 110 and a surface 120 opposite the Fresnel surface 110. In an embodiment of the invention, the surface 120 may be a planar, concave, convex or Fresnel surface, and in the present embodiment, the surface 120 is exemplified by a plane. The cross section shown in Fig. 1 includes an optical axis I of the Fresnel lens 100, that is, the optical axis I coincides with the cross section (XY plane) of Fig. 1.
菲涅耳面110包括多個使成像光線通過之菲涅耳有效面112。二相鄰的菲涅耳有效面112之間以菲涅耳無效面114互相連接。這些菲涅耳有效面112與這些菲涅耳無效面114之間交錯排列。在本發明的實施例中,菲涅耳有效面112係為一般光學透鏡具有其對應光學功能的曲面。舉例來說,若光學透鏡為會聚透鏡(例如是凸透鏡),則其對應的光學功能的曲面具有會聚功能,若光學透鏡為發散透鏡(例如是凹透鏡),則其對應的光學功能的曲面具有發散功能。因此,當光線通過菲涅耳有效面112時,會被菲涅耳有效面112折射而光線會被會聚或發散。另一方面,當光線通過菲涅耳無效面114時,則會被菲涅耳無效面114折射,而光線以非原光學設計考量的方式出射於菲涅耳透鏡100形成雜散光。在本實施例中,菲涅耳有效面112的形狀以具有會聚功能的凸面為例。於其他的實施例中,菲涅耳有效面112的形狀也可以是具有發散功能的凹面,本發明並不以此為限制。另一方面,在本實施例中,菲涅耳無效面114則是圓錐面。Fresnel face 110 includes a plurality of Fresnel effective faces 112 through which imaging light passes. The Fresnel ineffective faces 114 are interconnected between two adjacent Fresnel effective faces 112. These Fresnel effective faces 112 are staggered between these Fresnel ineffective faces 114. In an embodiment of the invention, the Fresnel effective surface 112 is a curved surface having a generally optical lens having its corresponding optical function. For example, if the optical lens is a converging lens (for example, a convex lens), its corresponding optically functional curved surface has a convergence function. If the optical lens is a diverging lens (for example, a concave lens), the corresponding optically functional curved surface has divergence. Features. Thus, as the light passes through the Fresnel effective surface 112, it is refracted by the Fresnel effective surface 112 and the light is concentrated or diverged. On the other hand, when the light passes through the Fresnel ineffective surface 114, it is refracted by the Fresnel ineffective surface 114, and the light exits the Fresnel lens 100 to form stray light in a non-original optical design consideration. In the present embodiment, the shape of the Fresnel effective surface 112 is exemplified by a convex surface having a converging function. In other embodiments, the shape of the Fresnel effective surface 112 may also be a concave surface having a diverging function, and the invention is not limited thereto. On the other hand, in the present embodiment, the Fresnel ineffective surface 114 is a conical surface.
由另一個觀點來看,這些菲涅耳有效面112與這些菲涅耳無效面114形成自光軸I沿徑向向外的多個齒S,且這些齒S包括中央齒SC以及多個周邊齒SP(於圖1中繪示中央齒SC與五個周邊齒SP作代表),中央齒SC與這些周邊齒SP自光軸I沿徑向向外分別為中央齒SC、第一周邊齒SP1、第二周邊齒SP2、第三周邊齒SP3、第四周邊齒SP4以及第五周邊齒SP5。徑向(Radial Direction)例如是正X軸的方向、負X軸的方向、正Z軸的方向、負Z軸的方向或其他垂直於Y軸的方向,其中光軸I平行於Y軸。在本實施例中,中央齒SC包括中央菲涅耳有效面112c,且光軸I通過中央菲涅耳有效面112c的中心。每一周邊齒SP包括菲涅耳有效面112以及菲涅耳無效面114。每一周邊齒SP具有菲涅耳透鏡100的齒峰以及菲涅耳透鏡100的齒谷。齒峰為該周邊齒SP對應至表面120的最大厚度的位置,而齒谷為該周邊齒SP對應至表面120的最小厚度的位置。各菲涅耳無效面114在包含菲涅耳透鏡100的一光軸I的截面上(即圖1的截面(XY平面)上)之一位於菲涅耳透鏡的100齒峰的一端與一位於菲涅耳透鏡100的齒谷的一端的一連接直線L與一參考線RL夾出拔模角θ。參考線RL平行於光軸I且通過菲涅耳有效面114之位於齒峰的一端。各拔模角θ之角度小於90度。這些拔模角θ包括一自光軸I徑向向外算起第一個的第一拔模角θ1、一自光軸I徑向向外算起第二個的第二拔模角θ2、一自光軸I徑向向外算起第三個的第三拔模角θ3、一自光軸I徑向向外算起第四個的第四拔模角θ4及自光軸I徑向向外算起第五個的第五拔模角θ5。From another point of view, these Fresnel effective faces 112 and the Fresnel ineffective faces 114 form a plurality of teeth S radially outward from the optical axis I, and these teeth S comprise a central tooth SC and a plurality of peripherals The tooth SP (represented by the central tooth SC and the five peripheral teeth SP in FIG. 1), the central tooth SC and the peripheral teeth SP are radially outward from the optical axis I as the central tooth SC and the first peripheral tooth SP1, respectively. The second peripheral tooth SP2, the third peripheral tooth SP3, the fourth peripheral tooth SP4, and the fifth peripheral tooth SP5. The Radial Direction is, for example, the direction of the positive X-axis, the direction of the negative X-axis, the direction of the positive Z-axis, the direction of the negative Z-axis, or other direction perpendicular to the Y-axis, wherein the optical axis I is parallel to the Y-axis. In the present embodiment, the central tooth SC includes a central Fresnel effective surface 112c and the optical axis I passes through the center of the central Fresnel effective surface 112c. Each of the peripheral teeth SP includes a Fresnel effective surface 112 and a Fresnel ineffective surface 114. Each of the peripheral teeth SP has a tooth peak of the Fresnel lens 100 and a valley of the Fresnel lens 100. The tooth peak is a position where the peripheral tooth SP corresponds to the maximum thickness of the surface 120, and the valley is a position where the peripheral tooth SP corresponds to the minimum thickness of the surface 120. One of the Fresnel ineffective faces 114 on one of the sections including the optical axis I of the Fresnel lens 100 (i.e., the cross section (XY plane) of FIG. 1) is located at one end of the 100 tooth peak of the Fresnel lens. A connecting line L at one end of the valley of the Fresnel lens 100 and a reference line RL sandwich the draft angle θ. The reference line RL is parallel to the optical axis I and passes through one end of the Fresnel effective surface 114 at the tooth peak. The angle of each draft angle θ is less than 90 degrees. The draft angle θ includes a first first draft angle θ1 from the optical axis I radially outward, and a second second draft angle θ2 from the optical axis I radially outward. A third third draft angle θ3 from the optical axis I radially outward, a fourth fourth draft angle θ4 from the optical axis I radially outward and a radial direction from the optical axis I The fifth fifth draft angle θ5 is calculated from the outside.
於本實施例中,在第一周邊齒SP1中,第一連接直線L1(第一菲涅耳無效面1141)與第一參考線RL1夾出第一拔模角θ1,且第一菲涅耳無效面1141與第二菲涅耳無效面1142之間僅具有一個第一菲涅耳有效面1121。在第二周邊齒SP2中,第二連接直線L2(第二菲涅耳無效面1142)與第二參考線RL2夾出第二拔模角θ2,且第二菲涅耳無效面1142與第三菲涅耳無效面1143之間僅具有一個第二菲涅耳有效面1122。在第三周邊齒SP3中,第三連接直線L3(第三菲涅耳無效面1143)與第三參考線RL3夾出第三拔模角θ3,且第三菲涅耳無效面1143與第四菲涅耳無效面1144之間僅具有一個第三菲涅耳有效面1121。在第四周邊齒SP4中,第四連接直線L4(第四菲涅耳無效面1144)與第四參考線RL4夾出第四拔模角θ4,且第四菲涅耳無效面1144與第五菲涅耳無效面1145之間僅具有一個第四菲涅耳有效面1124。在第五周邊齒SP5中,第五連接直線L5(第五菲涅耳無效面1145)與第五參考線RL5夾出第五拔模角θ5。這些拔模角θ的大小關係為:第二拔模角θ2大於第一拔模角θ1。第三拔模角θ3大於第二拔模角θ2。第四拔模角θ4大於第三拔模角θ3。第四拔模角θ4大於第三拔模角θ3。第五拔模角θ5大於第四拔模角θ4。換言之,這些拔模角θ的角度大小關係為自光軸I徑向向外漸增。In the present embodiment, in the first peripheral tooth SP1, the first connecting straight line L1 (the first Fresnel invalid surface 1141) and the first reference line RL1 sandwich the first draft angle θ1, and the first Fresnel There is only one first Fresnel effective surface 1121 between the ineffective surface 1141 and the second Fresnel inactive surface 1142. In the second peripheral tooth SP2, the second connecting straight line L2 (the second Fresnel invalid surface 1142) and the second reference line RL2 sandwich the second draft angle θ2, and the second Fresnel invalid surface 1142 and the third There is only one second Fresnel effective surface 1122 between the Fresnel ineffective faces 1143. In the third peripheral tooth SP3, the third connecting straight line L3 (the third Fresnel invalid surface 1143) and the third reference line RL3 sandwich the third draft angle θ3, and the third Fresnel invalid surface 1143 and the fourth There is only one third Fresnel effective surface 1121 between Fresnel ineffective faces 1144. In the fourth peripheral tooth SP4, the fourth connecting straight line L4 (the fourth Fresnel invalid surface 1144) and the fourth reference line RL4 sandwich the fourth draft angle θ4, and the fourth Fresnel invalid surface 1144 and the fifth There is only one fourth Fresnel effective surface 1124 between the Fresnel ineffective faces 1145. In the fifth peripheral tooth SP5, the fifth connecting straight line L5 (the fifth Fresnel ineffective surface 1145) and the fifth reference line RL5 sandwich the fifth draft angle θ5. The magnitude relationship of these draft angles θ is such that the second draft angle θ2 is greater than the first draft angle θ1. The third draft angle θ3 is greater than the second draft angle θ2. The fourth draft angle θ4 is greater than the third draft angle θ3. The fourth draft angle θ4 is greater than the third draft angle θ3. The fifth draft angle θ5 is greater than the fourth draft angle θ4. In other words, the angular relationship of these draft angles θ is gradually increasing radially outward from the optical axis I.
以下表一為一比較實施例的菲涅耳透鏡與圖1的實施例的菲涅耳透鏡在不同的視場角(View of Angle)下所測量到的最大照度。以下表二為比較實施例的菲涅耳透鏡與圖1的實施例的菲涅耳透鏡在不同的視場角下所測量到的雜散光面積。其中,在比較實施例的菲涅耳透鏡中,各拔模角的大小彼此相同。 <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 視場角(度) </td><td> 10 </td><td> 15 </td></tr><tr><td> 比較實施例的菲涅耳透鏡的雜散光最大照度(勒克斯,Lux) </td><td> 0.00196 </td><td> 0.00319 </td></tr><tr><td> 圖1的實施例菲涅耳透鏡的雜散光最大照度(勒克斯,Lux) </td><td> 0.00115 </td><td> 0.00146 </td></tr></TBODY></TABLE>表一 <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> 視場角(度) </td><td> 10 </td><td> 15 </td></tr><tr><td> 比較實施例的菲涅耳透鏡的雜散光面積(毫米<sup>2</sup>) </td><td> 44 </td><td> 36.44 </td></tr><tr><td> 圖1的實施例菲涅耳透鏡的雜散光面積(毫米<sup>2</sup>) </td><td> 88 </td><td> 56.4 </td></tr></TBODY></TABLE>表二 由上述的表一可知,在不同的視場角下,本實施例的菲涅耳透鏡100所產生的雜散光的最大照度皆小於比較實施例的菲涅耳透鏡所產生的雜散光最大照度。由上述的表二可知,在不同的視場角下,本實施例的菲涅耳透鏡100所產生的雜散光的面積皆大於比較實施例的菲涅耳透鏡所產生的雜散光面積。由此觀之,相較於比較實施例的菲涅耳透鏡,本實施例的菲涅耳透鏡100在不同的視場角下,能夠有效地降低雜散光的最大照度且在相同總雜散光能量的情況下分散雜散光分布的面積,以降低雜散光對成像品質的影響。因此,本實施例的菲涅耳透鏡100具有良好的光學成像品質。 Table 1 below shows the maximum illuminance measured at different viewing angles of a Fresnel lens of a comparative embodiment and a Fresnel lens of the embodiment of Fig. 1. Table 2 below is the stray light area measured by the Fresnel lens of the comparative embodiment and the Fresnel lens of the embodiment of Fig. 1 at different viewing angles. Among them, in the Fresnel lens of the comparative example, the size of each draft angle is the same as each other. <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> field of view (degrees) </td><td> 10 </td><td> 15 </td></tr><tr><td> The maximum illuminance of the stray light of the Fresnel lens of the comparative example (lux, Lux) </td><td> 0.00196 </td><td> 0.00319 < /td></tr><tr><td> The maximum illuminance of the stray light of the Fresnel lens of the embodiment of Fig. 1 (lux, Lux) </td><td> 0.00115 </td><td> 0.00146 </ Td></tr></TBODY></TABLE> Table 1 <TABLE border="1" borderColor="#000000" width="85%"><TBODY><tr><td> field of view (degrees) </td><td> 10 </td><td> 15 </td></tr><tr><td> The stray light area of the Fresnel lens of the comparative example (mm<sup>2</sup>) </td><td> 44 </td> <td> 36.44 </td></tr><tr><td> The stray light area of the Fresnel lens of the embodiment of Fig. 1 (mm<sup>2</sup>) </td><td> 88 </td><td> 56.4 </td></tr></TBODY></TABLE> Table 2 As can be seen from Table 1 above, the Fresnel lens 100 of the present embodiment is at different viewing angles. The maximum illuminance of the generated stray light is smaller than the maximum illuminance of the stray light generated by the Fresnel lens of the comparative example. As can be seen from Table 2 above, the area of stray light generated by the Fresnel lens 100 of the present embodiment is larger than the area of stray light generated by the Fresnel lens of the comparative example at different viewing angles. From this point of view, the Fresnel lens 100 of the present embodiment can effectively reduce the maximum illuminance of stray light and the same total stray light energy at different viewing angles compared to the Fresnel lens of the comparative embodiment. The area of the stray light distribution is dispersed to reduce the effect of stray light on the image quality. Therefore, the Fresnel lens 100 of the present embodiment has good optical imaging quality.
此外,在本實施例中,由於各菲涅耳無效面114為圓錐面,並且各菲涅耳無效面114與包含光軸I的截面相交的截線為直線,因此本實施例的菲涅耳透鏡100加工較為容易,且便於射出成型後的測量以及補正計算。並且,應注意的是,在圖1中,以五個周邊齒S以及對應的五個拔模角θ為代表,在第五周邊齒S5沿徑向向外可視需求增設其他的周邊齒。自第五周邊齒S5沿徑向向外所增設的齒數可以依序求作任意或適當的變化,本發明並不以此為限制。Further, in the present embodiment, since each Fresnel ineffective surface 114 is a conical surface, and the intersecting line of each Fresnel ineffective surface 114 intersecting the section including the optical axis I is a straight line, the Fresnel of the present embodiment The lens 100 is easier to machine and facilitates measurement and correction calculations after injection molding. Moreover, it should be noted that in FIG. 1, with the five peripheral teeth S and the corresponding five draft angles θ as representative, other peripheral teeth may be added in the radial direction outward in the fifth peripheral teeth S5. The number of teeth added from the fifth peripheral tooth S5 in the radial direction may be arbitrarily or appropriately changed, and the present invention is not limited thereto.
請參照圖2,圖2所示出的截面包含菲涅耳透鏡100a的一光軸I。圖2的實施例的菲涅耳透鏡100a大致上相似於圖1實施例的菲涅耳透鏡100,而兩者之間的差異在於:菲涅耳面110a中的這些菲涅耳無效面114a分別為在包含光軸I的截面方向上具有曲率之表面,也就是在圖2所示的截面上具有曲率之表面。透過上述的設計,本實施例的菲涅耳透鏡100a能夠更有效地將單一周邊齒SP所造成的雜散光導向不同方向,更能夠避免雜散光過度集中而出現明顯的光點或光斑,以降低雜散光對光學成像品質的影響。Referring to FIG. 2, the cross section shown in FIG. 2 includes an optical axis I of the Fresnel lens 100a. The Fresnel lens 100a of the embodiment of Fig. 2 is substantially similar to the Fresnel lens 100 of the embodiment of Fig. 1, with the difference between the Fresnel faces 110a in the Fresnel face 110a, respectively. It is a surface having a curvature in the direction of the section including the optical axis I, that is, a surface having a curvature on the section shown in FIG. Through the above design, the Fresnel lens 100a of the present embodiment can more effectively guide the stray light caused by the single peripheral tooth SP to different directions, and can prevent the excessive concentration of stray light and the appearance of obvious spots or spots to reduce The effect of stray light on optical imaging quality.
請參照圖3,圖3所示出的截面包含菲涅耳透鏡100b的一光軸I。圖3的實施例的菲涅耳透鏡100b大致上相似於圖1實施例的菲涅耳透鏡100,而兩者之間的差異在於:在菲涅耳透鏡100b中,各齒S在垂直於光軸I的方向(即正X軸的方向、負X軸的方向、正Z軸的方向、負Z軸的方向或在平行於XZ平面的任意方向)上的齒距P(Pitch)彼此相同。以下分別對中央齒SC的齒距Pc以及周邊齒SP的齒距P p分別作出定義。對於中央齒SC而言,中央齒SC在垂直於光軸I的方向上的齒距Pc則被定義為從光軸I至中央齒SC與第一周邊齒SP1(即最靠近中央齒SC的周邊齒SP1)之間的齒谷的距離。對於周邊齒SP而言,各周邊齒SP在垂直於光軸I的方向上的齒距P p被定義為各周邊齒SP在靠近光軸I的一側的齒谷與在遠離光軸I的一側的齒谷之間的距離。中央齒SC的齒距Pc等於各周邊齒SP的齒距P p,且這些周邊齒SP的齒距P p彼此相同。若要製造出具有曲率半徑較大的菲涅耳有效面112的菲涅耳透鏡,且以一定的齒深度來對應設計一齒S的齒距P,則一齒S的齒距P會較大,而這樣的菲涅耳透鏡較難以維持一定的齒數,而難以使得菲涅耳透鏡薄型化。因此,透過以各齒S的齒距P相同的設計,可以在維持一定的齒數的情況下,以較薄的厚度製造出具有較大曲率半徑的菲涅耳有效面112的菲涅耳透鏡100b。同時,透過上述的設計也可以使得菲涅耳面100b容易加工。具有較佳效果的齒距P的範圍為0.05毫米≦P≦0.60毫米。 Referring to FIG. 3, the cross section shown in FIG. 3 includes an optical axis I of the Fresnel lens 100b. The Fresnel lens 100b of the embodiment of Fig. 3 is substantially similar to the Fresnel lens 100 of the embodiment of Fig. 1, with the difference between: in the Fresnel lens 100b, each tooth S is perpendicular to the light The pitch P (Pitch) in the direction of the axis I (i.e., the direction of the positive X-axis, the direction of the negative X-axis, the direction of the positive Z-axis, the direction of the negative Z-axis, or any direction parallel to the XZ plane) is identical to each other. SC hereinafter for the center tooth pitch Pc, and the periphery of the teeth of the tooth pitch P p SP separate definitions. For the center tooth SC, the pitch Pc of the center tooth SC in the direction perpendicular to the optical axis I is defined as the distance from the optical axis I to the center tooth SC and the first peripheral tooth SP1 (ie, closest to the center tooth SC). The distance of the valley between the teeth SP1). For the peripheral teeth SP, the pitch P p of each of the peripheral teeth SP in the direction perpendicular to the optical axis I is defined as the valley of each peripheral tooth SP on the side close to the optical axis I and the distance from the optical axis I The distance between the valleys on one side. SC is the central tooth pitch Pc equal to each peripheral tooth pitch P p of the SP, the SP and the periphery of the teeth pitch P p identical to each other. If a Fresnel lens having a Fresnel effective surface 112 having a large radius of curvature is manufactured, and the pitch P of a tooth S is designed correspondingly with a certain tooth depth, the pitch P of one tooth S is larger. However, such a Fresnel lens is difficult to maintain a certain number of teeth, and it is difficult to make the Fresnel lens thin. Therefore, by designing the same pitch P of each tooth S, it is possible to manufacture the Fresnel lens 100b having the Fresnel effective surface 112 having a large radius of curvature with a relatively small thickness while maintaining a certain number of teeth. . At the same time, the Fresnel surface 100b can be easily processed by the above design. The pitch P of the preferred effect is in the range of 0.05 mm ≦ P ≦ 0.60 mm.
請參照圖4,圖4所示出的截面包含菲涅耳透鏡100c的一光軸I。圖4的實施例的菲涅耳透鏡100c大致上相似於圖1實施例的菲涅耳透鏡100,而兩者之間的差異在於:在菲涅耳透鏡100c中,各齒S在平行於光軸I的方向(即正Y軸的方向、負Y軸的方向、正Z軸的方向、負Z軸的方向或在平行於YZ平面的任意方向)上的齒深度SG(Sag)彼此相同。以下分別對中央齒SC的齒深度SGc以及周邊齒SP的齒深度SG p分別作出定義。對於中央齒SC而言,中央齒SC的齒深度SGc被定義為中央齒SC在光軸I處的頂點至中央齒SC的邊緣的齒谷(即中央齒SC與第一周邊齒SP1之間的齒谷)在平行於光軸I的方向上的距離。對於周邊齒SP而言,周邊齒SP的齒深度SG p被定義為該周邊齒SP的菲涅耳無效面114在包含光軸I的截面上之位於該周邊齒SP的齒峰的一端至位於該周邊齒SP的齒谷的一端在平行於光軸I的方向上的距離。中央齒SC齒深度SG c等於各周邊齒SP的齒深度SG p,且這些周邊齒SP的齒深度SG p彼此相同。由於靠近光軸I的菲涅耳有效面112較平緩,而遠離光軸I的菲涅耳有效面112較傾斜,因此若以同樣的齒深度SG來設計各齒S的齒距,則可以製造出具有距離光軸I較遠的第一周邊齒SP1的菲涅耳透鏡100c,因而可以避免接近成像中心的雜散光產生。同時,透過上述的設計也可以使得菲涅耳面100c容易加工。具有較佳效果的範圍為0.001毫米≦SG≦0.400毫米。 Referring to FIG. 4, the cross section shown in FIG. 4 includes an optical axis I of the Fresnel lens 100c. The Fresnel lens 100c of the embodiment of Fig. 4 is substantially similar to the Fresnel lens 100 of the embodiment of Fig. 1, with the difference between the two: in the Fresnel lens 100c, the teeth S are parallel to the light. The direction of the axis I (i.e., the direction of the positive Y-axis, the direction of the negative Y-axis, the direction of the positive Z-axis, the direction of the negative Z-axis, or any direction parallel to the YZ plane) is the same as each other. SC hereinafter for the central tooth and the surrounding teeth depth of the teeth SP SGc tooth depth separate definitions SG p. For the center tooth SC, the tooth depth SGc of the center tooth SC is defined as the valley of the center tooth SC at the apex of the optical axis I to the edge of the center tooth SC (ie, between the center tooth SC and the first peripheral tooth SP1) The distance of the valleys in the direction parallel to the optical axis I. For the peripheral tooth SP, the tooth depth SG p of the peripheral tooth SP is defined as the Fresnel invalid surface 114 of the peripheral tooth SP located at one end of the tooth peak of the peripheral tooth SP on the section including the optical axis I The end of the valley of the peripheral tooth SP is in a direction parallel to the optical axis I. SC central tooth gear SG c is equal to the depth of each peripheral tooth depth of the teeth SP SG p, peripheral teeth and these teeth SP SG p depths identical to each other. Since the Fresnel effective surface 112 close to the optical axis I is relatively gentle, and the Fresnel effective surface 112 away from the optical axis I is inclined, if the pitch of each tooth S is designed with the same tooth depth SG, it can be manufactured. The Fresnel lens 100c having the first peripheral tooth SP1 farther from the optical axis I can thereby prevent the generation of stray light near the imaging center. At the same time, the Fresnel surface 100c can be easily processed by the above design. A range having a better effect is 0.001 mm ≦ SG ≦ 0.400 mm.
應注意的是,為求圖面清楚展示,圖2至圖4中省略表示第四周邊齒S4、第五周邊齒S5以及對應的第四拔模角θ4、第五拔模角θ5,而其對應的相關敘述本領域的技術人員可參照圖1以及相關段落中得到支持。It should be noted that, in order to clearly show the drawings, the fourth peripheral teeth S4, the fifth peripheral teeth S5, and the corresponding fourth draft angle θ4 and the fifth draft angle θ5 are omitted in FIGS. 2 to 4, and Corresponding related descriptions can be supported by those skilled in the art with reference to Figure 1 and related paragraphs.
綜上所述,本發明上述實施例的菲涅耳透鏡可獲致下述的功效及優點:In summary, the Fresnel lens of the above embodiment of the present invention can achieve the following effects and advantages:
一、 本發明上述多個實施例的菲涅耳透鏡藉由設置自光軸I徑向向外角度漸增的拔模角θ,使得射至菲涅耳有效面112的成像光線最大化,射至菲涅耳無效面114的成像光線最小化,以降低雜散光的最大照度,並且於相同總雜散光能量的情況下分散雜散光分布的面積,使成像整體照度較均勻,降低局部照度不均的現象,進而達到成像清晰度提升的優點。並且,由於人眼的中央視野比起周邊視野敏感許多,故成像中央的清晰度提供人眼較明顯的感受,因此第一拔模角θ1至第五拔模角θ5設置自光軸I徑向向外角度漸增,能夠有效提升成像中央清晰度。1. The Fresnel lens of the above various embodiments of the present invention maximizes the imaging ray incident on the Fresnel effective surface 112 by providing a draft angle θ which is gradually increased from the optical axis I at a radially outward angle. The imaging light to the Fresnel invalid surface 114 is minimized to reduce the maximum illuminance of the stray light, and the area of the stray light distribution is dispersed under the same total stray light energy, so that the overall illumination of the image is relatively uniform, and the local illuminance is uneven. The phenomenon, in order to achieve the advantages of improved imaging clarity. Moreover, since the central field of view of the human eye is much more sensitive than the peripheral field of view, the sharpness of the center of the image provides a more pronounced perception of the human eye, so the first draft angle θ1 to the fifth draft angle θ5 are set from the radial direction of the optical axis I. The outward angle is increasing, which can effectively improve the central definition of the image.
二、若各拔模角θ大於等於1∘小於等於25∘,可以避免拔模角θ過小而於成形過程中脫模困難使透鏡結構受損,亦避免角度過大損失過多光學有效部。2. If each draft angle θ is greater than or equal to 1 ∘ and less than or equal to 25 ∘, the draft angle θ can be prevented from being too small, and the lens structure is difficult to be demolded during the forming process, and the excessive optical effective portion is also avoided.
三、在本發明上述多個實施例中的菲涅耳透鏡可以更增設一自光軸I徑向向外算起為第六個的第六拔模角、一自光軸I徑向向外算起為第七個的第七拔模角、一自光軸I徑向向外算起為第八個的第八拔模角、一自光軸I徑向向外算起為第九個的第九拔模角及一自光軸I徑向向外算起為第十個的第十拔模角,且第六拔模角大於第五拔模角,第七拔模角大於第六拔模角,第八拔模角大於第七拔模角,第九拔模角大於第八拔模角,第十拔模角大於第九拔模角,能夠更有效的降低雜散光的最大照度,降低局部照度不均的現象,進而達到成像清晰度提升。3. The Fresnel lens in the above various embodiments of the present invention may further include a sixth draft angle which is calculated from the optical axis I radially outward as a sixth, and a radial direction from the optical axis I. Calculated as the seventh seventh draft angle, one from the optical axis I radially outward as the eighth eighth draft angle, one from the optical axis I radially outwards as the ninth The ninth draft angle and one from the optical axis I are radially outwardly calculated as the tenth tenth draft angle, and the sixth draft angle is greater than the fifth draft angle, and the seventh draft angle is greater than the sixth The draft angle, the eighth draft angle is greater than the seventh draft angle, the ninth draft angle is greater than the eighth draft angle, and the tenth draft angle is greater than the ninth draft angle, which can more effectively reduce the maximum illumination of stray light , to reduce the phenomenon of uneven local illumination, and thus achieve improved imaging clarity.
四、在上述多個實施例的菲涅耳透鏡100、100a、100b、100c中鄰近菲涅耳面100、100a、100b、100c的一側上,若這些菲涅耳無效面114在包含光軸I的截面上的多個截線在垂直於光軸I的參考平面RP的多個正投影的長度的總和除以這些菲涅耳有效面112在包含光軸I的截面上的多個截線在垂直於光軸I的參考平面RP上的多個正投影的長度的總和的比值滿足小於等於0.230的條件,可以避免損失過多光學有效部,而達到良好的光學成像品質,且具有較佳效果的數值範圍是上述比值滿足小於等於0.230且大於等於0.045。其中,參考平面RP是由X軸與Z軸構成的XZ平面。4. On the side of the Fresnel lenses 100, 100a, 100b, 100c of the above-described plurality of embodiments adjacent to the Fresnel faces 100, 100a, 100b, 100c, if these Fresnel ineffective faces 114 are in the optical axis The sum of the lengths of the plurality of orthographic projections of the plurality of sections on the section perpendicular to the reference plane RP of the optical axis I divided by the plurality of sections of the Fresnel effective plane 112 on the section containing the optical axis I The ratio of the sum of the lengths of the plurality of orthographic projections on the reference plane RP perpendicular to the optical axis I satisfies the condition of 0.230 or less, thereby avoiding the loss of excessive optical effective portions, achieving good optical imaging quality, and having better effects. The numerical range is that the above ratio satisfies 0.230 or less and 0.045 or more. The reference plane RP is an XZ plane composed of an X axis and a Z axis.
雖然本發明已以實施例揭露如上,然其並非用以限定本發明,任何所屬技術領域中具有通常知識者,在不脫離本發明的精神和範圍內,當可作些許的更動與潤飾,故本發明的保護範圍當視後附的申請專利範圍所界定者為準。Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of the invention is defined by the scope of the appended claims.
100、100a、100b、100c‧‧‧菲涅耳透鏡100, 100a, 100b, 100c‧ ‧ Fresnel lens
110、110a、110b、110c‧‧‧菲涅耳面 110, 110a, 110b, 110c‧‧ Fresnel
112‧‧‧菲涅耳有效面 112‧‧‧ Fresnel effective noodles
120‧‧‧表面 120‧‧‧ surface
112c‧‧‧中央菲涅耳有效面 112c‧‧‧Central Fresnel Effective Side
1121‧‧‧第一菲涅耳有效面 1121‧‧‧First Fresnel Effective Face
1122‧‧‧第二菲涅耳有效面 1122‧‧‧Second Fresnel Effective Surface
1123‧‧‧第三菲涅耳有效面 1123‧‧‧ third Fresnel effective surface
1124‧‧‧第四菲涅耳有效面 1124‧‧‧Four Fresnel Effective Surface
1125‧‧‧第五菲涅耳有效面 1125‧‧‧ fifth Fresnel effective surface
114‧‧‧菲涅耳無效面 114‧‧‧ Fresnel invalid face
1141‧‧‧第一菲涅耳無效面 1141‧‧‧First Fresnel Invalid Face
1142‧‧‧第二菲涅耳無效面 1142‧‧‧Second Fresnel Invalid Face
1143‧‧‧第三菲涅耳無效面 1143‧‧‧ Third Fresnel Invalid Face
1144‧‧‧第四菲涅耳無效面 1144‧‧‧Four Fresnel Invalid Face
1145‧‧‧第五菲涅耳無效面 1145‧‧‧Five Fresnel Invalid Face
I‧‧‧光軸 I‧‧‧ optical axis
L‧‧‧連接直線 L‧‧‧Connected straight line
L1‧‧‧第一連接直線 L1‧‧‧ first connection line
L2‧‧‧第二連接直線 L2‧‧‧Second connection line
L3‧‧‧第三連接直線 L3‧‧‧ third connecting line
L4‧‧‧第四連接直線 L4‧‧‧fourth connecting straight line
L5‧‧‧第五連接直線 L5‧‧‧ fifth connection straight line
S‧‧‧齒 S‧‧‧ teeth
SC‧‧‧中央齒 SC‧‧‧Central tooth
SP‧‧‧周邊齒 SP‧‧‧ peripheral teeth
SP1‧‧‧第一周邊齒 SP1‧‧‧first peripheral tooth
SP2‧‧‧第二周邊齒 SP2‧‧‧Second peripheral tooth
SP3‧‧‧第三周邊齒 SP3‧‧‧ Third peripheral tooth
SP4‧‧‧第四周邊齒 SP4‧‧‧4th peripheral tooth
SP5‧‧‧第五周邊齒 SP5‧‧‧ fifth peripheral tooth
SG‧‧‧齒深度 SG‧‧‧ tooth depth
SGc‧‧‧中央齒的齒深度 SGc‧‧‧ tooth depth of the central tooth
SGp‧‧‧周邊齒的齒深度SG p ‧‧‧ tooth depth of the peripheral teeth
P‧‧‧齒距 P‧‧‧ pitch
Pc‧‧‧中央齒的齒距 Pc‧‧‧ the pitch of the central tooth
Pp‧‧‧周邊齒的齒距P p ‧‧‧ pitch of the surrounding teeth
RL‧‧‧參考線 RL‧‧ reference line
RL1‧‧‧第一參考線 RL1‧‧‧ first reference line
RL2‧‧‧第二參考線 RL2‧‧‧ second reference line
RL3‧‧‧第三參考線 RL3‧‧‧ third reference line
RL4‧‧‧第四參考線 RL4‧‧‧ fourth reference line
RL5‧‧‧第五參考線 RL5‧‧‧ fifth reference line
RP‧‧‧參考平面 RP‧‧‧ reference plane
X‧‧‧X軸 X‧‧‧X axis
Y‧‧‧Y軸 Y‧‧‧Y axis
Z‧‧‧Z軸 Z‧‧‧Z axis
θ‧‧‧拔模角 Θ‧‧‧ draft angle
θ1‧‧‧第一拔模角 Θ1‧‧‧first draft angle
θ2‧‧‧第二拔模角 Θ2‧‧‧second draft angle
θ3‧‧‧第三拔模角 Θ3‧‧‧ third draft angle
θ 4‧‧‧第四拔模角 θ 4‧‧‧four draft angle
θ 5‧‧‧第五拔模角 θ 5‧‧‧ fifth draft angle
圖1至圖4為本發明不同實施例的菲涅耳透鏡的截面示意圖。1 to 4 are schematic cross-sectional views of a Fresnel lens according to various embodiments of the present invention.
Claims (10)
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Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4824227A (en) * | 1985-11-20 | 1989-04-25 | North American Philips Corporation | Optimum riser angle for fresnel lenses in projection screens |
TW200933198A (en) * | 2008-01-28 | 2009-08-01 | Grand Plastic Technology Co Ltd | Structure of solar cell concentrator |
US20140226221A1 (en) * | 2011-09-20 | 2014-08-14 | Essilor International (Compagnie Generale D'optique) | Lens having a plurality of surfaces with zones |
CN104813200A (en) * | 2012-11-07 | 2015-07-29 | 松下知识产权经营株式会社 | Diffraction-grating lens, and image-capturing optical system and image-capturing device using said lens |
WO2017125979A1 (en) * | 2016-01-20 | 2017-07-27 | パナソニックIpマネジメント株式会社 | Head-up display |
-
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Patent Citations (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4824227A (en) * | 1985-11-20 | 1989-04-25 | North American Philips Corporation | Optimum riser angle for fresnel lenses in projection screens |
TW200933198A (en) * | 2008-01-28 | 2009-08-01 | Grand Plastic Technology Co Ltd | Structure of solar cell concentrator |
US20140226221A1 (en) * | 2011-09-20 | 2014-08-14 | Essilor International (Compagnie Generale D'optique) | Lens having a plurality of surfaces with zones |
CN104813200A (en) * | 2012-11-07 | 2015-07-29 | 松下知识产权经营株式会社 | Diffraction-grating lens, and image-capturing optical system and image-capturing device using said lens |
WO2017125979A1 (en) * | 2016-01-20 | 2017-07-27 | パナソニックIpマネジメント株式会社 | Head-up display |
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