1287168 九、發明說明： 【發明所屬之技術領域】 本發明係關於一種取像鏡頭，係應用於數 相機、气攝影機等等，特別是— 了達到低成本、南解析度的取像鏡頭。 ”、 【先前技術】 ' 近年來，相機由傳統的底片型相機演進到前 ΐ所以在取像鏡頭方面的要求就更高 j隹成像Γ貝、像面（取像元件面）入光的遠心要求以及 灸“、、距要長的需求，都大大的提高了取像鏡頭的規格。 ，目前數位取像模組的發展趨勢為輕、薄、短、小、以 之取像鏡頭往往會藉由減少鏡片數 itf t 取的設計、製作與量產都是極大的考驗， 疋t差的要求比較嚴苛的鏡頭，往往會因為用來生產鏡片的 ，仁、模具發生稍微的偏差，就很容易導致取像鏡頭所產生的影 ，品質出現極大的瑕疵，此外，公差嚴格的鏡頭，也會導致鏡片 的組裝不易的問題。在習知技術中，如JP2〇〇3-322792所提出的 ，頭架構，即顯現其為一色差比較高的例子，Jp2〇〇4—〇3796{)較 …、法滿足入光的遠心要求，jP2〇〇4-004566則公差容許度較緊。 因此，目前實在亟需一種取像鏡頭，同時要能提供高晝質與 小型化的特性，另一方面需具有較小的公差敏感度來降低製造與 組裝的困難度，以符合產業利用的需求。 【發明内容】 一,於以上的問題，本發明的主要目的在於提供一種取像鏡 碩，係透過控制鏡片形狀的設計，不但可笋決鏡頭小型化的問題， 並且符合咼畫素、高解析度的光學品質姜求，更具有較小的鏡頭 公差敏感度，而達到降低組裝誤差的效果，從而大體上改善先前 技術所存在之問題。 因此，為達上述目的，本發明所揭露之取像鏡頭，包含第一 鏡片、第二鏡片與第三鏡片，由靠近物面至成像面依排列順序算 起，第一鏡片是正光焦度，第二鏡片是負光焦度，而第三鏡片是 正光焦度；其中，此取像鏡頭必須滿足下列條件： 1287168 0.5 ^|R2/R3| ^5.0 的面之曲率半徑;及 马弟—鏡片中罪近物面的面之曲 入 取像鏡頭的設言十乃#溫错ti ΑΑ Α ^ 0.5 ^|R2/R3| ^5.0 其中，R2、·… R3 ….ι — ______ 有效的ΐ好使士當的控制，可以 解ffff發明的目的、構造、Γ寺ϋϋΐΙ進一牛的暸 解，炫配合貫施例詳細說明如下。 有進V的瞭 【實施方式】 根據本發明所揭露的取像鏡頭，如「第1 _ 3有弟一鏡片10、第二鏡片20、以及第三鏡片3〇,日笛一 度是正光焦度、第二鏡片20是負光焦度以^第三鏡/3()g 中ί斤繪示，本發明之取像鏡頭僅利用三片鏡片，不作所 鏡頭所採取之域配置中（即，第—鏡片1()、第二 $鏡片30分別為正光焦度、負光焦度與正光焦度），更進而可以 有效的設計整體鏡頭的長度。 另外，為了有效降低鏡片之組裝誤差敏感度，此取像鏡頭之 第一鏡片10與第二鏡片20必需滿足下列條件： 〇.5^|R2/R3|^5.0 其中’R2為弟一鏡片中靠近成像面的面之曲率半徑；及 R3為第二鏡片中靠近物面的面之曲率半徑。 而為了進一步降低第二鏡片之偏心敏感度，以提昇組裝及射 出良率，此取像鏡頭之第二鏡片必需滿足下列條件： |d/h|^0.14 . 其中，h為第二鏡片中靠近成像面的面於8〇%視場之主光線高； 及 d為該第二鏡片之靠近成像面的面中，當主光線高為h時 鏡面至鏡心的最大南低落差值。 此外，本實施例所提供之取像鏡頭可包括一光圈40與一紅 外線濾光板50 (IR cut filter)，光圈40是配置於第一鏡片10與物 面之間，用以調節進入的光量，而紅外線濾光板50則配置於第三1287168 IX. Description of the Invention: [Technical Field] The present invention relates to an image taking lens which is applied to a digital camera, a gas camera, etc., in particular, to a low cost, south resolution image taking lens. "[Previous technology]" In recent years, the camera has evolved from a conventional film-type camera to a front-end camera, so the requirements for the image-taking lens are higher. j隹 Imaging the mussel, the image surface (taking the image surface) into the light telecentricity The requirements and the demand for moxibustion, and the long distance, have greatly improved the specifications of the image taking lens. At present, the development trend of digital image capture modules is light, thin, short, and small. The lens for taking images is often tested by reducing the number of lenses. It is a great test, production and mass production. The demanding lens is often used because of the slight deviation of the core and the mold used to produce the lens. It is easy to cause the image produced by the lens, and the quality is extremely embarrassing. In addition, the lens with strict tolerance, It also causes problems in the assembly of the lens. In the prior art, as proposed in JP2〇〇3-322792, the head architecture, that is, an example in which a color difference is relatively high, Jp2〇〇4—〇3796{) is more suitable for the telecentric requirement of the light entering the light. , jP2〇〇4-004566 tolerance tolerance is tight. Therefore, there is an urgent need for an image taking lens, and at the same time, it is required to provide high quality and miniaturization characteristics, and on the other hand, it is required to have a small tolerance sensitivity to reduce the difficulty of manufacturing and assembly to meet the needs of industrial utilization. . SUMMARY OF THE INVENTION Firstly, in view of the above problems, the main object of the present invention is to provide an image capturing mirror, which is designed to control the shape of a lens, and can not only reduce the size of the lens, but also conform to the image and high resolution. The degree of optical quality of the ginger, with a smaller lens tolerance sensitivity, to achieve the effect of reducing assembly errors, thereby substantially improving the problems of the prior art. Therefore, in order to achieve the above object, the image taking lens disclosed in the present invention comprises a first lens, a second lens and a third lens, which are counted from the object surface to the imaging surface, and the first lens is a positive power. The second lens is a negative power, and the third lens is a positive power; wherein the image capturing lens must satisfy the following conditions: 1287168 0.5 ^|R2/R3| ^5.0 radius of curvature of the face; and Ma Di - lens In the face of the sin near the surface of the face into the lens of the lens set ten is #温错 ti ΑΑ Α ^ 0.5 ^|R2/R3| ^5.0 where R2, ... R3 ....ι — ______ effective ΐ The control of the sect can be used to solve the purpose of the ffff invention, the structure, and the understanding of the sacred temple. [Invention] According to the image taking lens disclosed in the present invention, such as "the first _ 3 brothers have a lens 10, a second lens 20, and a third lens 3", the Japanese flute is once a positive power. The second lens 20 is a negative power of the third lens / 3 () g, the imaging lens of the present invention uses only three lenses, not in the domain configuration adopted by the lens (ie, The first lens 1 () and the second lens 30 are positive power, negative power and positive power, respectively, and the length of the overall lens can be effectively designed. In addition, in order to effectively reduce the assembly error sensitivity of the lens The first lens 10 and the second lens 20 of the image taking lens must satisfy the following conditions: 〇.5^|R2/R3|^5.0 where 'R2 is the radius of curvature of the face of the lens near the imaging surface; and R3 It is the radius of curvature of the surface of the second lens close to the object surface. To further reduce the eccentricity sensitivity of the second lens to improve the assembly and ejection yield, the second lens of the image taking lens must satisfy the following conditions: |d/ h|^0.14 . where h is the surface of the second lens near the imaging surface at 8〇% field of view The main ray is high; and d is the maximum south-low drop value of the mirror-to-mirror when the chief ray is high h in the plane of the second lens near the imaging surface. In addition, the image taking lens provided in this embodiment may include An aperture 40 and an IR cut filter 50 are disposed between the first lens 10 and the object surface for adjusting the amount of light entering, and the infrared filter 50 is disposed in the third