200942394 九、發明說明： 【發明所屬之技術領域】 - 本發明係有關於一種光學模仁加工補償方法，特別 地，本方法依據一光學系統的波前誤差進行補償修正。 【先前技術】 隨著光學工業及光電科技的發展，各式各樣的光學元 件與光電系統依不同的需求孕育而生，而光學鏡片即為各 ❹種光學系統中不可或缺的零組件之一。除了一般大眾所熟 知的天文望遠鏡與攝影機之外，在數位相機、雷射印表機、 影印機及投影機等產品上的應用亦已普及化，對光學鏡片 的品質與精度的要求亦愈來愈高。 目前工業用光學鏡片若以使用材料及其製造方法來區 分，主要有傳統之玻璃鏡片研磨拋光、模造玻璃鏡片及塑 膠射出成形等三大類。傳統鏡片研磨抛光的生產方式以一 連串的圓整、成形、研磨、拋光、定心等程序來製作鏡片， ©*僅加工過程緩慢又涉及相當多的技術，尤其非球面鏡片 (aspheric surfaee)製作更不容易。其次，在製造非球面鏡片 方法方面’現今已有業界使用破璃模造加工及塑膠射出成 形(plastic injection molding)技術’且前述兩種技術皆利用 模仁及模具以壓模或射出方式而成形。 還需講述地，目前業界對於非球面鏡片内的模仁加工 部分，亦是將非球面鏡月設計參數輪入電腦數值控制(CNc) 而對該模仁進行加工，然後輸入至CNc鑽石車床進行修正 5 200942394 加工，以切削出使用者所要的鏡面形狀。200942394 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention relates to an optical mold processing compensation method. In particular, the method compensates for the wavefront error of an optical system. [Prior Art] With the development of optical industry and optoelectronic technology, a variety of optical components and optoelectronic systems have emerged according to different needs, and optical lenses are indispensable components in various optical systems. One. In addition to the astronomical telescopes and cameras that are well known to the general public, applications in digital cameras, laser printers, photocopiers, and projectors have become popular, and the requirements for the quality and precision of optical lenses are increasing. The higher the height. At present, industrial optical lenses are mainly classified into three types: conventional glass lens polishing, molded glass lens, and plastic injection molding, depending on the materials used and their manufacturing methods. The traditional lens grinding and polishing method uses a series of rounding, forming, grinding, polishing, centering and other procedures to make the lens. ©* Only the processing process is slow and involves a lot of technology, especially the aspheric surfaee. not easy. Secondly, in the method of manufacturing an aspherical lens, the plastic injection molding technique and the plastic injection molding technique have been used in the industry today, and both of the above techniques are formed by die or injection using a mold and a die. It is also necessary to tell the story. At present, for the mold processing part in the aspherical lens, the aspherical lens design parameter is also wheeled into the computer numerical control (CNc) and the mold core is processed, and then input to the CNC diamond beard for correction. 5 200942394 Machining to cut out the mirror shape desired by the user.
需主意的般對鏡片的模仁形狀精度的要求是以鏡 決定.例如低精度的如眼鏡鏡片等，高精度的如 先碟機讀取頭等’通常對形狀精度的要求從1〇_到（U 間甚或更小。因此，在進行模仁設計時，需預先將 旲W射出過程中產生的收縮、輕曲、變形、内部應力等 效應一併考慮。 不幸的事’對於鏡片製作過程中，影響鏡片形狀之 因素錯綜複雜，於模仁設計時難以考慮周全，因此針對鏡 片的變形狀況進行模仁補償（_pensating)修正是玻璃模 造與塑膠射a成形等鏡片製作方法中非常重要的工作。傳 統做法上’將模造玻璃鏡片或塑膠射出鏡片放置於3D輪 廓掃描儀上’湘3D輪軸描儀掃描光學鏡;i的外形輪 廓，再將掃描完的輪廓利用線性迴歸法(Linear regression) 求出外型輪廓开)狀’以得知鏡片外形計算值與設計值的尺 ❹寸誤差’再依此誤差進行模仁補償。此種補償方式對鏡頭 (或光學系統)每一個鏡片的2個面都需進行補償處理，且 補償效果只能針對單一鏡片，補償過程費時甚久且無法彌 補鏡頭組裝所產生的系統誤差。 簡明地說’非球面玻璃鏡片的精密度對於光學系統性 月b有著相當重要的關係，而在模仁加工過程中，如果模仁 誤差補償技術做的不好，所生產出來的鏡片與設計值不 同’則所組裝的光學系統達不到設計規範的性能。但即使 所有鏡片的精度都達到設計要求，光學組裝亦可能產生誤 200942394 差’使得光學系統效能降低。 一因此如有一種模仁加工補償的方法，不只是針對光 :兀，（鏡片或機構件）進行補償，而是針對光學系統或光 •子儀器進行補償，則可將光學元件製造誤差與光學系 統組 裝誤差一併補償處理。 【發明内容】 • 、因此本發明的目的就是在提供一種光學模仁加工補償 '' 、干/歩儀為量測工具’以量測光學鏡頭的波前誤差， 其中波前誤差可以用Zernike多項式來表示，為光學系統 中鏡片製作誤差與組裝誤差所造成。再將此波前誤差反向 輸入光學設計軟體中，利用光學軟體優化功能調整部分鏡 片外形參數或鏡片間距等，使得光學系統經部分鏡片外形 參數或鏡片間距調整後，其波前與反向輸入之波前誤差吻 合’亦即調整光學系統中部分鏡片外形參數或鏡片間距恰 ❹ 可彌補由干涉儀 量測所得之波前誤差。如此，便能在調校 一個或數個光學元件的情況下使光學系統符合設計要求， 改進了以往針對每個光學元件一一進行模仁補償卻又無法 保證組裝後光學系統品質的困擾。 根據本案之構想，提出一種光學模仁加工補償方法， 係包含下列步驟:(a)依據一光學設計結果以取得一光學系 統的雛形(prototype) ; (b)量測該光學系統的雛形之波前誤 差（wavefront error); (c)將該波前誤差反向（inverse)回饋至 一光學設計軟體，並在該光學設計軟體内選定部分設計參 200942394 3:::學+系統優化以得到-組的設計參數:以及(d)根 參數與該光學設計結果之差異值進行一(： 【實施方式] 術步預定目的所採取之技 且具的、特徵與特點，當可由此得-深入 用來對本發式僅提供參考與說明用，並非 償尺差十補:差係針Λ單-鏡之外形輪麻進行補 全無從補:二差等先學系統誤差，完 能表現。因此，本發明提出 、係適用在光學系統或光學儀器的基本元件（光學鏡 頌）上。以下為本發明之詳細說明。 ❹ 如第1圖所示，此圖為補償的方法之流程圖。首先， 步驟100.依據一光學設计結果以取得一光學系統（光學鏡 頭）的離形(prototype)，其中’前述光學設計結果亦是依使 用者的要求下所設定一光學鏡片（以下簡稱鏡片）的參數， 如一鏡片之鏡面形狀參數（shape parameter)與表明光學系 統中各元件相關位置（將定義一鏡片於該光學系統中所在 位置與方向，如該鏡片的位置、該鏡片與另一鏡片之間的 間距與該鏡片的傾角等）之參數，以及製造該光學鏡片的材 料。再者，為人所熟知的’前述所提及的光學系統的離形 200942394 亦是光學系統之一原型形式（original type) ’在建立在新設 計光學系統過程中，無可避免地’仍存有不可預期的問題， 所以，於開始大量生產該光學系統的產品之前’取得該光 學系統的雛形，以能測試(test)及感受（feel)此新設計光學系 統的功能是有其必要性的。 步驟110:量測該光學系統的離形之波前誤差 (wavefront error)，在該光學系統的雛形之波前誤差所使用 的儀器，於本實施例中’係使用一干涉儀(interferometer)， Φ 然而令人理解地，此干涉儀通常用來量測一球面鏡或平面 鏡的表面狀況（亦是，平面鏡片與球面鏡片（凸面與凹面）光 學元件的表面形狀誤差）’係以準直雷射光穿過標準鏡頭 (平面或球面標準鏡頭）後所形成之標準波前（平面波前或球 面波前)與鏡片的表面做比較以形成干涉圖形，藉由分析干 涉圖形即可得知該鏡片的鏡面表面形狀誤差等狀況。同樣 的，也可用來量測該光學系統的波前誤差。如同量測表面 形狀誤差般，可分析干涉圖形得知系統波前誤差。此波前 ❹ 誤差為光學系統中各光學元件製造時產生之形狀誤差（鏡 面形狀誤差、鏡片偏心與傾斜、光機件尺寸誤差與偏心等） 與系統組裝誤差所累積造成的’一般可用Zernike函數來表 示。 步驟120:將該光學系統的雛形之該波前誤差反向回饋 (negative feedback)至如 Zemax、Code-V 或 OSLO 此類型的 一光學設計軟體來作分析（亦是將取得的Zernike函數輸入 至該光學設計軟體内），並在該光學設計軟體内選定多個設 計參數進行該光學系統優化（optimization)以得到一組的設 200942394 s十參數，而在選定多個設計參數方面為多個鏡片形狀參數 及多個鏡片位置參數，其中前述鏡片形狀參數為該等鏡片 的曲率半徑（radius)、非球面（aspheric)係數、該鏡片之厚 . 度。前述鏡片位置參數為定義該等鏡片於該光學系統中所 在位置與方向之參數，如該鏡片位置、該鏡片與另—鏡片 之間的間距與該鏡片的傾角等。如第2A圖及第2B圖所 示，利用此光學軟體優化功能調整該光學系統中一個或數 個鏡片之設計參數，使補償後的光學系統之波前恰吻合該 傷 光學系統的雛形之反向波前誤差，以補償原光學系統因製 作、組裝所累積的誤差。 步驟130:根據該組的設計參數與該光學設計結果之差 異值以進行一光學模仁補正。 而在步驟130中’在對該光學模仁進行補正後，若補正 不佳，回至步驟120，以得到另一組的設計參數，進行進一 步光學模仁補正。 Ο 最後，還需提及的，在步驟120中所選用的多個設計參 數的選項中可為多個鏡片形狀參數(shape parameter)及多 個鏡片位置參數之一或其兩種參數組合。 以上所述係利用較佳實施例詳細說明本發明，而非限 制本發明的範圍，本案得由熟習此技術之人士任施匠思而 為諸般修飾，然皆不脫本案申請專利範圍所欲保護者。 【圖式簡單說明】 第〗圖係繪示本發明之光學模仁加工補償方法之流程 200942394The requirement for the shape accuracy of the lens of the lens is determined by the mirror. For example, low-precision such as spectacle lens, high-precision such as the first disc reader head, etc., usually the shape accuracy requirement is from 1〇 to (U is even smaller or smaller. Therefore, in the design of the mold, it is necessary to consider the effects of shrinkage, buckling, deformation, internal stress, etc. generated during the injection of 旲W. Unfortunately, the lens is in the process of making the lens. The factors affecting the shape of the lens are complicated and difficult to consider in the design of the mold. Therefore, the correction of the lens compensation for the deformation of the lens is a very important work in the lens manufacturing methods such as glass molding and plastic injection molding. In practice, 'mold the molded glass lens or the plastic injection lens on the 3D contour scanner', the 3D wheel scanner scanning optics; i's outline, and then use the linear regression method to find the outer contour. The contour is opened and the shape is 'to know the calculated value of the lens shape and the size error of the design value' and then the mold compensation is performed according to the error. This compensation method requires compensation for both faces of each lens of the lens (or optical system), and the compensation effect can only be applied to a single lens. The compensation process takes a long time and cannot compensate for the systematic error caused by the lens assembly. Concisely speaking, the precision of the aspherical glass lens has a very important relationship with the optical system month b. In the process of mold core processing, if the mold error compensation technology is not done well, the lens and design value produced are The different 'optical systems assembled' do not meet the performance specifications. But even if the accuracy of all lenses meets the design requirements, optical assembly may also produce errors. 200942394 The difference is that the optical system performance is reduced. Therefore, if there is a method of compensation for mold processing, not only for light: 兀, (lens or machine member) compensation, but for optical system or optical sub-instrument compensation, optical component manufacturing error and optics The system assembly error is compensated for. SUMMARY OF THE INVENTION The object of the present invention is to provide an optical mold processing compensation '', dry/歩 instrument as a measuring tool' to measure the wavefront error of an optical lens, wherein the wavefront error can be Zernike polynomial To indicate that it is caused by lens manufacturing errors and assembly errors in the optical system. Then, the wavefront error is reversely input into the optical design software, and the optical software optimization function is used to adjust some lens shape parameters or lens pitches, so that the optical system is adjusted by partial lens shape parameters or lens spacing, and its wavefront and reverse input. The wavefront error coincides with the adjustment of the lens shape parameters or the lens spacing in the optical system to compensate for the wavefront error measured by the interferometer. In this way, the optical system can be designed to meet the design requirements with one or several optical components adjusted, and the previous method of performing mold compensation for each optical component without improving the quality of the assembled optical system can be improved. According to the concept of the present invention, an optical mold processing compensation method is proposed, which comprises the following steps: (a) obtaining an prototype of an optical system according to an optical design result; (b) measuring a prototype wave of the optical system (front) error (waveform); (c) back-feeding the wavefront error back to an optical design software, and designing the selected portion of the optical design software to participate in 200942394 3::: learning + system optimization to get - The design parameters of the group: and (d) the difference between the root parameter and the optical design result is one (: [Embodiment] The skill, characteristics, and characteristics of the intended purpose of the step are obtained. To provide only reference and explanation for this hair style, it is not a compensation for ten feet: the difference between the needle and the single-mirror is not complete: the second difference is the first systematic error, and the performance is good. Therefore, this book The invention is applicable to the basic elements (optical mirrors) of optical systems or optical instruments. The following is a detailed description of the invention. ❹ As shown in Fig. 1, this figure is a flow chart of the method of compensation. First, the steps 100. An optical design result to obtain a prototype of an optical system (optical lens), wherein the optical design result is also a parameter of an optical lens (hereinafter referred to as a lens) set according to a user's request, such as a lens The shape parameter of the mirror is related to the position of each component in the optical system (the position and orientation of a lens in the optical system will be defined, such as the position of the lens, the spacing between the lens and the other lens, and The parameters of the inclination of the lens, etc., and the material from which the optical lens is made. Furthermore, the known release of the aforementioned optical system 200942394 is also an original type of optical system. Established in the process of designing an optical system, it is inevitable that there are still unpredictable problems. Therefore, before starting mass production of the optical system, the prototype of the optical system can be obtained to test and feel. (feel) The function of this new design optical system is necessary. Step 110: Measure the wavefront error of the optical system (wavefront error), the instrument used in the wavefront error of the prototype of the optical system, in this embodiment 'uses an interferometer, Φ. However, it is understood that the interferometer is usually used for measurement. The surface condition of a spherical or flat mirror (also, the surface shape error of a flat lens and a spherical lens (convex and concave) optical element) is formed by collimating laser light through a standard lens (planar or spherical standard lens) The standard wavefront (planar wavefront or spherical wavefront) is compared with the surface of the lens to form an interference pattern, and the shape of the mirror surface shape of the lens can be known by analyzing the interference pattern. Similarly, it can also be used to measure the wavefront error of the optical system. As with the measurement of the surface shape error, the interference pattern can be analyzed to know the system wavefront error. This wavefront 误差 error is the general usable Zernike function caused by the shape error (mirror shape error, lens eccentricity and tilt, lens size error and eccentricity) generated by the optical components in the optical system and system assembly error. To represent. Step 120: Negative feedback of the wavefront error of the prototype of the optical system to an optical design software such as Zemax, Code-V or OSLO for analysis (also inputting the obtained Zernike function to The optical design software), and selecting a plurality of design parameters in the optical design software for the optical system optimization to obtain a set of 10 parameters of 200942394 s, and multiple lenses in selecting a plurality of design parameters The shape parameter and the plurality of lens position parameters, wherein the lens shape parameter is a radius of curvature, an aspheric coefficient, and a thickness of the lens. The aforementioned lens position parameters are parameters defining the position and orientation of the lenses in the optical system, such as the position of the lens, the spacing between the lens and the other lens, and the inclination of the lens. As shown in FIG. 2A and FIG. 2B, the optical software optimization function is used to adjust the design parameters of one or several lenses in the optical system, so that the wavefront of the compensated optical system coincides with the prototype of the injured optical system. The wavefront error is compensated for the error accumulated in the original optical system due to fabrication and assembly. Step 130: Perform an optical mold replenishment based on the difference between the design parameters of the set and the optical design result. In step 130, after the optical mold is corrected, if the correction is not good, the process returns to step 120 to obtain another set of design parameters, and further optical mold compensation is performed. Finally, it is also mentioned that the options for the plurality of design parameters selected in step 120 may be one of a plurality of lens shape parameters and a plurality of lens position parameters or a combination of the two. The above is a detailed description of the present invention, and is not intended to limit the scope of the present invention. The present invention is modified by those skilled in the art, and is not intended to be protected by the scope of the patent application. By. [Simplified description of the drawings] The first diagram shows the flow of the optical mold processing compensation method of the present invention 200942394
第2 A圖及第2 B圖係分別繪示於一光學系統的雛形及 一光學設計中輸入反向波前誤差之示意圖。 【主要元件符號說明】 100:依據一光學設計結果以取得一光學系統的雛形 (prototype)； 110:量測該光學系統的雛形之波前誤差（wave front error); 120:將該波前誤差反向（inverse)回饋至一光學設計軟 體，並在該光學設計軟體内選定部分設計參數進行該光學 系統優化，使該光學系統之波前與反向輸入之波前誤差相 吻合，以得到一組的設計參數；以及 130:根據該組的設計參數與該光學設計結果之差異值 進行一光學模仁補正。 11Figures 2A and 2B are diagrams showing the input of the inverse wavefront error in the prototype of an optical system and an optical design, respectively. [Description of main component symbols] 100: According to an optical design result to obtain a prototype of an optical system; 110: measuring the wavefront error of the prototype of the optical system; 120: the wavefront error of the optical system Inverse feedback to an optical design software, and selecting a part of the design parameters in the optical design software to optimize the optical system, so that the wavefront of the optical system matches the wavefront error of the reverse input to obtain a a set of design parameters; and 130: an optical mold correction based on the difference between the set of design parameters and the optical design result. 11