201229557 六、發明說明： 【發明所屬之技術領域】 本發明是關於一種影像擷取系統，尤係關於一種能夠縮小系統體積 與提升照明效率之影像擷取系統。 【先前技術】 影像擷取技術中，尤其是應用於生物腔體的影像擷取技術，因生物 腔體内部無光源提供照明，且生物腔體的開口通常較小，因此必須提 供一適當的外部照明能夠通過腔體的開口且提供足夠亮度的照明光 線’使成像系統擷取腔體内部反射的成像光線，以清楚且準確地觀察 或拍攝腔體内部的影像。 一習知技術為一照明系統中利用一環型中空反射鏡用以反射一光 源的光線並搭配透鏡組使照明光線能夠進入腔體的開口，成像光經過 環型中空反射鏡的中空區域以成像，然而一般光源的發光強度分佈為 数伯特(Lambertian)分布或高斯(Qaussian)分布，其中央部份強度較強， 環型中空反射鏡將無法將光源中央部份的光線反射提供照明，造成照 明的效率不佳。 另一習知技術為提供一照明系統，其利用一點光源搭配一反射鏡與 透鏡組將照明光線聚焦至腔體的開口上，再藉由與照明系統離軸設置 的成像系統擷取出腔體的成像光以成像。雖然解決了照明效率不佳的 問題，但由於照明系統與成像系統為離軸設置，因此使用的光學部件 數量較多’製造成本提高。另外系統體積與長度也將會增加，限制系 統的視角度(field of view) ’無法設計成大視角及大光圈的系統，且照明 與成像的視野不同’降低拍攝的準確性。 綜上所述，如何有致縮減系統體積並有效提升光學效率便是目前極 需努力的目標。 201229557 【發明内容】 本發明係提供一種影像擷取系統，利用透鏡物像關係設置光源位 置，使照明光能夠充分進入腔體内部大幅提升照明效率，並將成像與 照明的％件整合在m可達成縮小體積，節省成本的優勢。201229557 VI. Description of the Invention: [Technical Field] The present invention relates to an image capturing system, and more particularly to an image capturing system capable of reducing system volume and improving lighting efficiency. [Prior Art] In the image capturing technology, especially the image capturing technology applied to the biological cavity, since there is no light source inside the biological cavity to provide illumination, and the opening of the biological cavity is usually small, it is necessary to provide an appropriate external Illumination is able to pass through the opening of the cavity and provide illumination light of sufficient brightness to cause the imaging system to capture the imaged light reflected inside the cavity to clearly and accurately view or photograph the image inside the cavity. A conventional technique is to use a ring-shaped hollow mirror to reflect light of a light source and to cooperate with a lens group to enable illumination light to enter an opening of the cavity, and the imaging light passes through a hollow area of the annular hollow mirror for imaging. However, the luminous intensity distribution of a general light source is a Lambertian distribution or a Gaussian distribution, and the central portion has a strong intensity. The annular hollow mirror will not be able to illuminate the central portion of the light source to provide illumination. The efficiency is not good. Another conventional technique is to provide an illumination system that uses a light source with a mirror and a lens group to focus the illumination light onto the opening of the cavity, and then extracts the cavity by an imaging system disposed off-axis with the illumination system. Imaging light to image. Although the problem of poor lighting efficiency is solved, since the illumination system and the imaging system are arranged off-axis, the number of optical components used is large, and the manufacturing cost is increased. In addition, the volume and length of the system will also increase, limiting the system's field of view 'cannot be designed as a system with large viewing angle and large aperture, and the illumination and imaging field of view are different' to reduce the accuracy of shooting. In summary, how to reduce the size of the system and effectively improve the optical efficiency is the goal that is currently in great demand. 201229557 SUMMARY OF THE INVENTION The present invention provides an image capturing system that uses a lens image relationship to set a position of a light source, so that the illumination light can fully enter the interior of the cavity to greatly improve the illumination efficiency, and integrates the imaging and illumination components. Achieve the advantages of reducing the size and saving costs.
依據本發明之一實施例之影像擷取系統，用以擷取具有一開口之一 腔體之一影像，其影像擷取系統包含一第一透鏡組、一光源以及一成 像模組。其中第一透鏡組定義一焦距、一第一光軸位置以及一第二光 軸位置，其中，第一光軸位置以及第二光軸位置位於第—透鏡組之相 對側之一光軸上，並滿足以下關係： 丄+丄-丄 D2 / . 其中，D1為第一光軸位置至第一透鏡組之距離，D2為第二光軸位 置至第一透鏡組之距離，f為焦距；光源偏離第一透鏡組之光軸設置， 且光源至第一透鏡組之距離大於焦距且小於第一光軸位置至第一透鏡 組之距離。光源與第一透鏡組光學耦合並提供一照明光，其中照明光 通過第一透鏡組並匯聚於腔體内部之後發散，以照明腔體的内面。成An image capturing system according to an embodiment of the present invention is configured to capture an image of a cavity having an opening, the image capturing system comprising a first lens group, a light source, and an imaging module. The first lens group defines a focal length, a first optical axis position, and a second optical axis position, wherein the first optical axis position and the second optical axis position are located on an optical axis of the opposite side of the first lens group, And satisfy the following relationship: 丄+丄-丄D2 / . where D1 is the distance from the first optical axis position to the first lens group, D2 is the distance from the second optical axis position to the first lens group, and f is the focal length; Offset from the optical axis of the first lens group, and the distance from the light source to the first lens group is greater than the focal length and less than the distance from the first optical axis position to the first lens group. The light source is optically coupled to the first lens group and provides an illumination light, wherein the illumination light is diverged after passing through the first lens group and concentrating inside the cavity to illuminate the inner face of the cavity. to make
像模組設置於光軸上，用以接受腔體之表面所反射之一成像光，以护 成影像。 V 本發明上述及其他態樣、特性及優勢可由附圖及實施例之說明而可 更加了解。 【實施方式】 請同時參考圖1以及圖2,圖i為示意_示依據本發明—實施例 之影像操取系統；圖2為本發明-實施例之影彳_取系統中決定光源 設置的位置的示意圖。本發明之影像擷取系統用以擷取具有一開口 U 之一腔體1的影像。以下的說明中所使用的上、下、左、右等方位敘 述僅依照圖示上_關位置描述，以方便制，_以限定本發明。 本發明一實施例之影像擷取系統包含：一第一透鏡組2〇、一光源3〇以 201229557 及-成像模組40。其中第一透鏡組2〇的焦點F具有一焦距f、一光轴 X通過第-透鏡組2G ’並在光軸χ上㈣―第_光轴位置A以及_第 -光軸位置B ’其中’第—光軸位置A以及第二光軸位置B位於第一 透鏡組20之相對側，並滿足以下關係： 去+忐=}…式1The image module is disposed on the optical axis for receiving one of the imaging light reflected by the surface of the cavity to protect the image. The above and other aspects, features and advantages of the present invention will become more apparent from the description of the appended claims. [Embodiment] Please refer to FIG. 1 and FIG. 2 simultaneously. FIG. 1 is a schematic diagram showing an image manipulation system according to an embodiment of the present invention. FIG. 2 is a diagram of determining a light source setting in a shadow-taking system according to the present invention. Schematic of the location. The image capturing system of the present invention is used to capture an image of a cavity 1 having an opening U. The above descriptions of the top, bottom, left, and right orientations used in the following description are only described in accordance with the above-described positional description for convenience of the present invention. The image capturing system of the embodiment of the present invention comprises: a first lens group 2, a light source 3, and a 201229557 and an imaging module 40. The focal point F of the first lens group 2A has a focal length f, an optical axis X passes through the first lens group 2G' and is on the optical axis (four) - the optical axis position A and the - optical axis position B ' 'The first optical axis position A and the second optical axis position B are located on the opposite side of the first lens group 20, and satisfy the following relationship: go to +忐=}...1
Dl>f，D2>f···式 2 可以理解的是，式1為透鏡成像公式，其中，D1為第-光軸位置 A至第-透鏡组2〇之距離，D2為第二光轴位置B至第一透鏡組2〇之 距離。光源30包含至少—點光源，可為—發光二極體或—發光光纖， 其偏離光軸X設置’絲源3Q至第—魏組2G之聰大於焦距？且 小於第-絲位置A JL第-透鏡組2Q之雜，較佳者，第—光轴位置 A至第-透鏡組20之距離D1大於二倍距f，題丨設置於第一透 鏡組20的左側且腔體1的開口 i i至第—透鏡組2()之距離實質上等於 第一光軸位置B至第一透鏡組2〇之距離D2。 接續上述’光源30與第-透鏡組2〇光學搞合並提供一照明光 3〇1 ’其中照明光301通過第-透鏡組2〇並匯聚於腔體i内部之後發 散’以照明腔體1内部之-表面12。成像模組4〇設置於光轴χ上， 於-實施例中’成像模組40包含—第二透鏡組41與—影像感測元件 42，成像模組4Q用以接受腔體丨之表面12所反射之—成像光规，成 像光302依序通過腔體1之開D u、第一透鏡組2〇以及第二透鏡租^ 達到影像感測元件42，以形成影像。其中影像感測元件42可為一電荷 耦合元件(Charge Coupled Deviee，CCD)、互補式金屬氧化物半導體 (c〇mplementary Metal 0xide Semiconduct〇r，CM〇s)感測器、軟片⑼叫 或，上之組合。於-實施财，成像模組4Q更包含—光闌43，其設置 ^第-透鏡組2G與統3G之間’用以限制光軸χ外的鱗進又成像 模组40。可以理_是’第-透鏡組2〇及二透鏡組41可為變焦 透鏡組’用以調整焦距以清楚形成影像。 201229557Dl>f, D2> f··· Equation 2 It can be understood that Equation 1 is a lens imaging formula in which D1 is the distance from the optical axis position A to the first lens group 2〇, and D2 is the second optical axis. The distance from the position B to the first lens group 2〇. The light source 30 comprises at least a point light source, which may be a light emitting diode or a light emitting fiber, which is disposed away from the optical axis X. The wire source 3Q to the first group 2G is greater than the focal length. And less than the first wire group A JL first lens group 2Q, preferably, the distance D1 of the first optical axis position A to the first lens group 20 is greater than the double distance f, and the problem is set in the first lens group 20 On the left side and the distance from the opening ii of the cavity 1 to the first lens group 2 () is substantially equal to the distance D2 from the first optical axis position B to the first lens group 2A. The light source 30 and the first lens group 2 are optically combined to provide an illumination light 3〇1 'where the illumination light 301 is diverged after passing through the first lens group 2 and converges inside the cavity i to illuminate the interior of the cavity 1 - surface 12. The imaging module 4 is disposed on the optical axis. In the embodiment, the imaging module 40 includes a second lens group 41 and an image sensing component 42. The imaging module 4Q is configured to receive the surface of the cavity. The reflected-imaging light gauges, the imaging light 302 sequentially passes through the opening D u of the cavity 1, the first lens group 2〇, and the second lens to reach the image sensing element 42 to form an image. The image sensing component 42 can be a Charge Coupled Deviee (CCD), a complementary metal oxide semiconductor (C〇mplementary Metal 0xide Semiconduct〇r, CM〇s) sensor, or a film (9) called or The combination. In the implementation, the imaging module 4Q further includes a diaphragm 43 disposed between the first lens group 2G and the system 3G to limit the scale of the optical axis and the imaging module 40. It is to be understood that the 'first lens group 2' and the second lens group 41 may be zoom lens groups' for adjusting the focal length to clearly form an image. 201229557
的極化方向不同，舉例來說， 第一光學偏極片71與第二光學偏極片72 第一光學偏極片71為一水平方向偏極片 而-光學偏極片72為-垂直方向偏極片，光源3〇透過第一光學偏 極片71發出且經由第-透鏡組2〇反射至成像模組4〇方向的光線，其 偏極化方向與第—光學偏極片72之偏極化方向相差⑽度，將無法通 過第二光學偏極片72，而僅允許與第二光學偏極片72極化方向相同的 成像光302通過，因此可提升影像品質。如圖3所示，於一實施例中， 第-光學偏極片71可環設於第二光學偏極片72周圍，但不以此為限。 可以理解的是，第-光學偏極片71可與光源3Q整合為—模組，用以 發出具有一特定極化方向的照明光3〇i。 於一實施例中，更包含一濾光片，其與光源3〇光學耦合，用以發 出特定波長範圍的照明光3〇1，或者於另一實施例中，濾光片可與成像 模組40光學耦合，使成像模組40僅接收一波長範圍的成像光302。較 佳者，如圖1所示，於一實施例中’更包含兩濾光片8〇、81分別設置 與照明光301與成像光302光學轉合，舉例來說，於圖1的實施例中， 濾光片80設置於光源30與第一光學偏極片71之間；濾光片81設置 於成像模組40的第二透鏡組41與影像感測元件42之間，但不以此為 限。濾光片80、81用以濾除一波長範圍的光線。根據光源30與腔體1 的表面12特性，僅讓特定波長的照明光301與成像光302通過，提升 應用範圍與影像品質。 本發明之影像擷取系統中決定光源設置的位置的方式請參考圖2 與以下說明，要注意的是，為方便說明，圖2中省略成像模組40之圖 示。假設第二光軸位置B上具有一像高r的成像I，則由式1的透鏡成 201229557 ◦的一光軸位置A的方向上具有-虛擬的物〇，此物 第-光之投影位置為 其值為像高乘、7轴位置A距離即為物〇的高度， 。丨豕円r乘以弟一透鏡組2〇的放大率。 包含—第—光錐501的光線，第一光錐501 第-光錐的上，絲請下j絲線別2,其中 第一光錐的下緣光線5012愈第-透二2〇 —光學邊界2〇1 ; 直中雜紅^ e ” 透鏡組20父於一第二光學邊界202， ’、轴位置c與第-光學邊界201位The polarization direction is different. For example, the first optical polarizer 71 and the second optical polarizer 72 are the first polarizer 71 and the optical polarizer 72 is the vertical direction. The polarizing plate, the light source 3 is transmitted through the first optical polarizing plate 71 and reflected by the first lens group 2〇 to the direction of the imaging module 4, and the polarization direction thereof is offset from the first optical polarizing plate 72. The polarization directions are different (10) degrees, and the second optical polarizer 72 cannot pass, but only the imaging light 302 having the same polarization direction as that of the second optical polarizer 72 is allowed to pass, so that the image quality can be improved. As shown in FIG. 3, in an embodiment, the first optical polarizer 71 can be disposed around the second optical polarizer 72, but is not limited thereto. It can be understood that the first optical polarizer 71 can be integrated with the light source 3Q as a module for emitting illumination light 3〇i having a specific polarization direction. In one embodiment, a filter is further included, which is optically coupled to the light source 3A for emitting illumination light 3-1 of a specific wavelength range, or in another embodiment, the filter can be combined with the imaging module. The optical coupling 40 causes the imaging module 40 to receive only imaging light 302 of a range of wavelengths. Preferably, as shown in FIG. 1 , in an embodiment, the two filters 8 , 81 are respectively disposed to be optically coupled with the illumination light 301 and the imaging light 302 , for example, in the embodiment of FIG. 1 . The filter 80 is disposed between the light source 30 and the first optical polarizer 71; the filter 81 is disposed between the second lens group 41 and the image sensing component 42 of the imaging module 40, but not Limited. Filters 80, 81 are used to filter out light in a range of wavelengths. According to the characteristics of the light source 30 and the surface 12 of the cavity 1, only the illumination light 301 of a specific wavelength and the imaging light 302 are passed, thereby improving the application range and image quality. For the manner of determining the position of the light source setting in the image capturing system of the present invention, please refer to FIG. 2 and the following description. It should be noted that the illustration of the imaging module 40 is omitted in FIG. 2 for convenience of explanation. Assuming that the image I of the image height r at the second optical axis position B has a virtual object 方向 in the direction of an optical axis position A of 201229557 式, the projection position of the first light of the object The value is the image height, and the 7-axis position A distance is the height of the object.丨豕円r is multiplied by the magnification of the lens group 2〇. The light containing the first-light cone 501, the first light cone 501 on the first-light cone, the silk is the next j-wire line 2, wherein the lower edge of the first light cone 5012 is the first - transparent 2 - optical boundary 2〇1 ; straight middle red ^ e ” lens group 20 father at a second optical boundary 202, ', axis position c and first-optical boundary 201
學邊界201與第二光學邊界2〇2 ==，而弟一光 篦一氺μ、息田〜 1々、尤釉λ之相對側。要說明的是， 二γ，201與第二光學邊界搬是指第一 ^疋 =出之光線產_作_邊界，例如第—透鏡 == 位置Α的物〇光雜合，並在第二雜㈣β形絲像第先軸 第二光轴位置八發出一第二光錐502的光線， 先隹502匕3-第_光錐的上緣光線簡 =其分別與第一透鏡組20交於第一光學邊 及2。光源30將設置於離軸位置c以及第一透鏡組2〇之第—光學邊 界201之連線與第-光轴位置A與第一透鏡組2〇之第二光學 J連線的交點E。設置於交點E的光源3G發出的照明光則便會 第-透鏡組20之第-光學邊界加與第二光學邊界2〇2之間的範圍， =明f〇i沿著第-光錐的上緣光線削、第二光錐的下緣光線5〇22 與第-透鏡組20光學輕合’並於第一透鏡組2〇的焦點f與腔體i内 部的表面12之間匯聚’而非匯聚於第—光軸位置a或第—透鏡組2〇 的焦點F，因此成像I的高度小於開口内徑的二分之一，照明光細 能夠充分進入腔體1内部大幅提升照明效率。 -另外’由圖2可知’照明光301沿著第一光錐的上緣光線5〇n的 路徑與第-透鏡組2〇光學搞合後偏折的角度較照明光3〇1沿著第二光 錐的下緣光線5G22的路徑與第—透鏡組2G光學_合後偏折的角度 小，因此照明光301於第二光軸位置”照明光3〇1於腔體ι内匯^ 201229557 的交點之間距離光軸X的最高高度的變化較小，使得照明光3〇】可以 有較大的前後移動容許度’即腔體1的開口 11設置於此範圍之間皆可 讓照明光301充分進入腔體1内部。可以理解的是，本發明之影^操 取系統中可根據腔體1的開口 11大小，在垂直光軸X的方向上調整光 源30設置的位置(交點E) ’當交點E的位置距離光軸X較遠時，可以 使用大角度及大光圈的成像模組40。因為本發明之影像擷取系統將負 責成像與照明的元件整合在一系統中，可達成縮小體積，節省成本的 優勢。另外，腔體1可為眼部’開口 U為瞳孔，腔體1亦可為耳鼻喉 部、皮膚、腹腔'胃腔…等等等器官。本發明之影像擷取系統可:廣 泛地應用於内視鏡(光管型或是膠囊型）、生物顯微攝影等領域或任= 級的數位醫療攝影系統。 / 。 另外，光源30的照明光301是直接與第一透鏡組2〇光學耦合， ，並不會S為統30偏離絲X設置而使亮度不均勻，進而提^照明 f率。也因為光源3〇偏離光軸χ設置，所以也不會存在成像時會 鬼影的問題。於一實施例中，腔體Μ開口 u對稱光轴乂，且^口 “ 的開口内大小為二倍的像高r，照明光3〇1通過開口 1 八 圍。較佳者，光源30可為一環型光源’如圖4A所示，盆： 數 本發明圖示）’形成—環型光源。於另—實施例中， 3〇為==含—反織置⑻，_Β所示，其中光源 率。 咐出之先線反射至第一透鏡組2〇，提升照明效 ,’ &上述本發明之影像掏取系統中，根據第-Μ 物體與第—透鏡㈣ 卿弟-先軸位置上的 先干輕合後，在第一光軸位置成像的第-光錐與第 201229557 一光錐的邊緣的交點以決定光源設置的離軸位置。光源為離軸設置且 所發出的照明光直接與第-透鏡組光料合，因此無鬼影以及照明亮 度不均勻的問題。照明光通過第—透鏡組之後匯驗體内部，於腔體 ^開口處提供充分的照明，大幅提升照明效率。另外，設置於離軸位 =源可以梳大的前後職容許度，並且本伽之影像擷取系統 太像與照明的元件整合在'魏中，可達成縮小體積，節省成 尽的優勢。 其目 以;上所述之實施例僅是為說明本發明之技術思想及特點 处在使热！此項胁之人士能夠瞭解本發明之内 明之專利範圍，即大凡依本發明所揭 …又化或修姆，仍應涵蓋在本發明之專利範圍内。y月 之 201229557 【圖式簡單說明】 _ 圖1為依據本發明一實施例之影像擷取系統之示意圖。 圖2為依據本發明一實施例之醫療影像擷取系統中決定光源設置 的位置的示意圖。 圖3為依據本發明一實施例之影像擷取系統之第一光學偏極片與 第二光學偏極片之示意圖。 圖4A為依據本發明一實施例之影像擷取系統之光源之示意圖。 圖4B為依據本發明一實施例之影像擷取系統之光源之示意圖。 【主要元件符號說明】 1 腔體 11 開口 12 表面 20 第一透鏡組 201 第一光學邊界 202 第二光學邊界 30 光源 301 照明光 302 成像光 31 發光二極體 40 成像模組 41 第二透鏡組 42 影像感測元件 201229557 43 光闌 60 反射裝置 71 第一光學偏極片 72 第二光學偏極片 80、81 濾光片 501 第一光錐 5011 第一光錐的上緣光線 5012 第一光錐的下緣光線 502 第二光錐 5021 第二光錐的上緣光線 5022 第二光錐的下緣光線 A 第一光軸位置 B 第二光軸位置 C 離軸位置 F 焦點 f 焦距 r 像高、内徑 X 光軸 I 成像 0 物 E 交點 D1 第一光軸位置至第一透鏡組之距離 12 201229557 D2 第二光軸位置至第一透鏡組之距離The learning boundary 201 and the second optical boundary 2〇2 ==, and the opposite side of the brothers 光一篦μ, 息田~1々, especially glaze λ. It should be noted that the second γ, 201 and the second optical boundary move means that the first light ray is produced, and the second light ray is mixed, for example, the first lens == position Α The fourth (four) β-shaped wire is like the second optical axis of the first axis, and the light of the second light cone 502 is emitted. The upper edge of the first light beam 502 is = 隹 隹 第 第 第 第 = = = = = = = = = The first optical edge and 2. The light source 30 sets the line connecting the off-axis position c and the first optical boundary 201 of the first lens group 2A with the intersection E of the first optical axis position A and the second optical J line of the first lens group 2A. The illumination light emitted by the light source 3G disposed at the intersection E will have a range between the first optical boundary of the first lens group 20 and the second optical boundary 2〇2, = 〇f〇i along the first light cone The edge ray is cut, the lower edge ray 5 〇 22 of the second light cone is optically coupled with the first lens group 20 and converges between the focal point f of the first lens group 2 与 and the surface 12 inside the cavity i. Converging at the first optical axis position a or the focal point F of the first lens group 2〇, the height of the imaging I is less than one-half of the inner diameter of the opening, and the illumination light can sufficiently enter the interior of the cavity 1 to greatly improve the illumination efficiency. - In addition, it can be seen from Fig. 2 that the angle of the illumination light 301 along the path of the upper edge ray 5 〇 n of the first light cone and the first lens group 2 〇 are deflected at an angle smaller than that of the illumination light 3 〇 1 The path of the lower edge ray 5G22 of the two-light cone is smaller than the angle of the optical lens y-folding of the first lens group 2G, so that the illumination light 301 is at the second optical axis position "the illumination light 3 〇 1 is in the cavity ι ^ 201229557 The change from the highest point of the optical axis X between the intersections is small, so that the illumination light can have a large forward and backward movement tolerance, that is, the opening 11 of the cavity 1 is disposed between the ranges to allow illumination light to be 301 fully enters the interior of the cavity 1. It can be understood that in the image manipulation system of the present invention, the position of the light source 30 can be adjusted in the direction of the vertical optical axis X according to the size of the opening 11 of the cavity 1 (intersection point E). 'When the position of the intersection E is far from the optical axis X, a large angle and large aperture imaging module 40 can be used. Since the image capturing system of the present invention integrates components responsible for imaging and illumination into one system, achievable Reduce the size and save cost. In addition, the cavity 1 can be opened for the eyes U is a pupil, and the cavity 1 can also be an organ such as an ear, a nose, a skin, an abdominal cavity, a stomach cavity, etc. The image capturing system of the present invention can be widely applied to an endoscope (light tube type or capsule type). In the field of biological microphotography or any digital medical imaging system of the grade. / In addition, the illumination light 301 of the light source 30 is directly optically coupled with the first lens group 2, and does not deviate from the wire 30. X is set to make the brightness uneven, and thus the illumination f rate. Also, since the light source 3 is offset from the optical axis, there is no problem that ghosting occurs during imaging. In one embodiment, the cavity opening u The symmetrical optical axis 乂, and the size of the opening in the opening of the mouth is twice the image height r, and the illumination light 3〇1 passes through the opening 1 . Preferably, the light source 30 can be a ring-shaped light source ' as shown in Figure 4A, the basin: number of the present invention' In another embodiment, 3〇 is == contains-reverse weave (8), _Β, where the light source ratio. The first line of the sputum is reflected to the first lens group 2〇 to enhance the illumination effect, &<> in the image capturing system of the present invention, according to the first object and the first lens (four) After dry and light, the intersection of the first light cone imaged at the first optical axis position and the edge of the 201229557 light cone determines the off-axis position of the light source setting. The light source is off-axis and the emitted illumination light is directly combined with the first lens group, so there is no problem of ghosting and uneven illumination brightness. After passing through the first lens group, the illumination light passes through the inside of the inspection body to provide sufficient illumination at the opening of the cavity to greatly improve the illumination efficiency. In addition, it is set in the off-axis position = the source can be combed before and after the tolerance, and the image acquisition system of this gamma is too integrated with the lighting components in the 'Weizhong, can achieve a reduction in size, saving the advantage. The embodiments described above are merely for explaining the technical idea and features of the present invention. The subject matter of the invention is to be understood as being within the scope of the invention as defined by the appended claims.于月201229557 [Simple Description of the Drawings] FIG. 1 is a schematic diagram of an image capturing system according to an embodiment of the present invention. 2 is a schematic diagram of determining a position of a light source setting in a medical image capturing system according to an embodiment of the invention. 3 is a schematic diagram of a first optical polarizer and a second optical polarizer of an image capturing system according to an embodiment of the invention. 4A is a schematic diagram of a light source of an image capture system in accordance with an embodiment of the invention. 4B is a schematic diagram of a light source of an image capture system in accordance with an embodiment of the invention. [Main component symbol description] 1 cavity 11 opening 12 surface 20 first lens group 201 first optical boundary 202 second optical boundary 30 light source 301 illumination light 302 imaging light 31 light emitting diode 40 imaging module 41 second lens group 42 image sensing element 201229557 43 aperture 60 reflection device 71 first optical polarization plate 72 second optical polarization plate 80, 81 filter 501 first light cone 5011 upper edge of the first light cone 5012 first light The lower edge of the cone 502 The second cone 5021 The upper edge of the second cone 5022 The lower edge of the second cone A The first optical axis position B The second optical axis position C Off-axis position F Focus f Focal length r Image High, inner diameter X optical axis I imaging 0 object E intersection point D1 distance of the first optical axis position to the first lens group 12 201229557 D2 distance of the second optical axis position to the first lens group