200949426 九、發明說明： 【發明所屬之技術領域】 本發明涉及光學成像領域，特別是一種基於複數攝像 裝置的成像設備。 -【先前技術】 . 目前，為了拍攝某一物體的整體且細節的影像，可將 整排攝像裝置排列在一起，同時進行取像及影像處理，也 就是所謂的陣列影像。如圖1所示，傳統的成像設備20包括 ®複數攝像裝置10，且所述複數攝像裝置10排成一排，同時 對被拍物體200進行拍攝。如果攝像裝置10距離被拍物體 200較遠，取像範圍102則較大，攝像裝置10距離被拍物體 200較近，取像範圍102則較小。 一般而言，取像範圍102的大小決定取像的解析度，即 取像範圍102越大則取像的解析度越差，而取像範圍102越 小則解析度越高。當取像範圍102較大，攝像裝置10間的距 _離較寬，這時攝像裝置10的排列較沒有問題。 但是，因為拍攝精度的要求，很多時候都需要較高的 解析度，此時攝像裝置10距離被拍物體200較近，攝像裝置 10間的距離受到攝像裝置10尺寸的限制而無法再縮短時， 各攝像裝置10的取像範圍之間就可能出現空隙104,也即不 能同時取得被拍物體200當前位置的完整影像。 【發明内容】 鑒於此，有必要提供一種可取得被拍物體完整且高精 度影像的成像設備。 5 200949426 一種成像設備，其包括複數攝像裝置，用於同時對被 拍物體取像’該複數攝像裝置至少分為二組，該成像設備 還包括光學元件’該光學元件位於至少一組攝像裝置與被 拍物體之間的光路中’用於改變來自被拍物體光線的傳播 -方向，且該組攝像裝置通過該光學元件對被拍物體取像。 - 上述成像設備利用光學元件改變來自被拍物體的部分 或者全部光線的傳播方向，那麼就可以將原本需要排成一 排的複數攝像裝置分散’為攝像裝置之間爭取了空間。同 時，由於位於同一排的攝像裝置的取像範圍之間都可以留 下間隙’因為這些間隙正好由其他排攝像裝置的取像範圍 來填補’如此便有效地解決了因為攝像裝置尺寸限制而導 致不能取得完整影像的問題’從而取得被拍物體完整且高 精度影像。 【實施方式】 請參閱圖2’其為第一較佳實施方式的成像設備3〇的結 ❹構示意圖。成像設備30包括：複數第一攝像裝置301、303、 305、307、309 ’ 複數第二攝像裝置 3〇2、304、306、308， 長條形半透半反射透鏡250。 複數第一攝像裝置301、303、305、307、309排成一排 且取像方向一致，下稱其為：第一排攝像裝置。複數第二 攝像裝置302、304、306、308也排成一排且取像方向一致， 下稱其為：第二排攝像裝置。第一排攝像裝置與第二排攝 像裝置相互平行且取像方向相互垂直。長條形半透半反射 透鏡250與第一排攝像裝置和第二排攝像裝置平行’且位於 6 200949426 第一排攝像裝置和第二排攝像裝置的取像方向的相交處’ 半透半反射透鏡250分別與第一排攝像裝置和第二排攝像 裝置的取像方向呈45度角。在同時垂直第一排攝像裝置和 第二排攝像裝置的方向上，第一排攝像裝置的複數第一攝 •像襞置301、303、305、307、309與第二排攝像裝置的複數 -第二攝像裝置302、304、306、308交替設置。 如此，第一排攝像裝置分別利用來自被拍物體2〇〇並透 ▲過半透半反射透鏡250的光線取像。第二排攝像裝置分別利 〇 用來自被拍物體200並由半透半反射透鏡250反射的光線取 像。由於第一排攝像裝置與第二排攝像裝置的相互平行且 交替設置，使得第一排攝像裝置的取像範圍311與第二排攝 像裝置的取像範圍322也排成一排且交替排列。相對現有技 術，該成像設備30利用半透半反射透鏡250將原本需要排成 一列的複數攝像裝置（3〇1〜309)分成了位置交錯設置的 兩排攝像裝置，為攝像裝置之間爭取了空間。而且每一排 ❹攝像裝置的複數取像範圍之間都可以留下間隙，因為這些 間隙可以由另一排攝像裝置的取像範圍來填補，如此便有 效地解決了因為攝像裝置尺寸限制而導致不能取得完整影 像的問題，從而能夠取得被拍物體完整且高精度影像。後 續可藉由圖像分析即可實現對被拍物體200的光學檢測或 者用於其他用途。 本實施方式中，半透半反射透鏡250作為一個改變來自 被拍物體200光線傳播方向的光學元件，且為一個獨立光學 元件。其他實施方式中，半透半反射透鏡250也可以由複數 7 200949426 半透半反射透鏡組成’每個半透半反射透鏡對應一個攝像 裝置。 請參閱圖3,其為第二較佳實施方式的成像設備5〇的結 構示意圖。成像設備50與圖2所示的成像設備3〇的區別在 •於：成像設備50利用複數反射鏡550代替了成像設備30中的 -半透半反射透鏡250’第一排攝像裝置與第二排攝像裝置平 行且相對設置，在二者的取像方向上，第一排攝像裝置的 複數第一攝像裝置301、303、305、307、309與第二排攝像 、 裝置的複數第二攝像裝置302、304、306、308交替設置。 所述複數反射鏡550排成一排，並與第一排攝像裝置和 第二排攝像裝置平行，且位於二者之間。所述複數反射鏡 550分為二組：第一組反射鏡551和第二組反射鏡552，第一 組反射鏡551和第二組反射鏡552的反射鏡550交替設置，以 分別與第一排攝像裝置與第二排攝像裝置對應。第一組反 射鏡551的反射面面向第一排攝像裝置’並與第一排攝像裝 ❿置的取像方向成45度角。第二組反射鏡552的反射面面向笫 二排攝像裝置’並與第二排攝像裝置的取像方向成45度角。 如此，第一排攝像裝置分別利用來自被拍物體20〇ϋ由 第一級反射鏡551反射的光線取像。第二排攝像裝置分別利 用來自被拍物體200並由第二組反射鏡552反射的光線取 像。同樣，由於第一排攝像裝置與第二排攝像裝置的平行 以及交錯設置’使得第一排攝像裝置的取像範圍311與第二 排攝像裝置的取像範圍322排成一排且交替排列，也解決了 因為攝像裝置尺寸限制而導致不能取得完整影像的問題， 8 200949426 從而能夠取得被拍物體完整且高精度影像。 請參閱圖4,其為第三較佳實施方式的成像設備70的結 構示意圖。成像設備70與圖3所示的成像設備50的區別在 於：成像設備70去掉了第一組反射鏡551。與之對應的，第 一排攝像裝置的取像方向變為與第二排攝像裝置的取像方 .向垂直，從而通過第二組反射鏡552之間的間隔直接對被拍 物體200取像，如此可以減少成像設備70的光學器件。 請參閱圖5,其為第四較佳實施方式的成像設備90的結 ®構示意圖。成像設備90與圖3所示的成像設備50的區別在 於：成像設備90利用複數直角三棱鏡950代替成像設備30 中的複數反射鏡550。複數直角三稜鏡950同樣也分為兩 組：第一組三棱鏡951和第二組三稜鏡952，其位置關係與 複數反射鏡550相同，不再贅述。所有直角三稜鏡950的一 個直角面軍與其對應的攝像裝置的取向方向垂直，以利用 直角三棱鏡950斜面的反射特性將來自被拍物體200的光線 @分別反射到第一排攝像裝置和第二排攝像裝置上。本實施 方式採用直角三稜鏡950的原因是因為三稜鏡950在裝配時 更容易固定。 請參閱圖6,其為第五較佳實施方式的成像設備91的結 構示意圖，成像設備91與圖5所示的成像設備90的區別在 於：成像設備91去掉了第一組三棱鏡951。與之對應的，第 一排攝像裝置的取像方向變為與第二排攝像裝置的取像方 向垂直，從而通過第二組三稜鏡952之間的間隔直接對被拍 物體200取像，如此可以減少成像設備91的光學器件。 9 200949426 特殊情況下，若要求拍攝影像的解析度很高，也許兩 排攝像裝置緊靠時的取像範圍之間仍然存在間隙，那麼就 需要三排甚至更多排攝像裝置來同時取像，下面以三排為 例進行詳細說明。 請參閱圖7,其為第六較佳實施方式的成像設備99的結 -構示意圖。成像設備99具有三排攝像裝置：複數第三攝像 裝置401、404、407 ’複數第四攝像裝置402、405、408， 複數第五攝像裝置403、406、409。複數第三攝像裝置401、 ® 404、407排成一排且取像方向一致，下稱其為：第三排攝 像裝置。複數第四攝像裝置402、405、408排成一排且取像 方向一致，下稱其為：第四排攝像裝置。複數第五攝像裝 置403、406、409也排成一排且取像方向一致，下稱其為： 第五排攝像裝置。三排攝像裝置相互平行，第三排攝像裝 置相對第四排攝像裝置設置，第五排攝像裝置的取像方向 與第三排攝像裝置和第四排攝像裝置設置的取像方向垂 ©直。 成像設備99還包括第三組反射鏡450,第四組反射鏡 460。所述第三組反射鏡450和第四組反射鏡460排成—排且 與第三排攝像裝置、第四排攝像裝置、第五排攝像裝置平 行，並位於第三排攝像裝置和第四排攝像裝置之間。所述 第三組反射鏡450和第四組反射鏡460的複數反射鏡交替排 列且兩個兩個一套，每套之間具有間隔470。第三排攝像| 置通過第三組反射鏡450對被拍物體200取像，第四排攝像 裝置通過第四組反射鏡460對被拍物體200取像，第五排攝 200949426 像裝置透過所述間隔470直接對被拍物體2〇〇取像。如此， 第三排攝像裝置，第四排攝像裝置，第五排攝像裳置的取 像範圍也排成一排且交替排列。 從上述列舉的第一至第六個實施方式可以看出，其原 -理就是利用光學元件改變將來自被拍物體2〇〇的部分或者 •全部光線，藉由反射、透射甚至折射的形式改變為一個或 者複數與原始光線傳播方向不同的光線，那麼就可以將原 ❹本需要排成一排的攝像裝置分成兩組或兩組以上甚至更為 分散的複數攝像裝置，為攝像裝置之間爭取了空間。同時， 由於位於同一排的攝像裝置的取像範圍之間都可以留下間 隙，因為這些間隙可由其他排的攝像裝置的取像範圍來填 補，如此便可有效地解決因為攝像裝置尺寸限制而導致不 月b取得完整影像的問題，從而取得被拍物體完整且高精度 影像。 本技術領域的普通技術人員應當認識到，以上的實施 ❹方式僅是用來說明本發明，而並非用作為對本發明的限 疋’只要在本發明的實質精神範圍之内，對以上實施例所 作的適當改變和變化都落在本發明要求保護的範圍之内。 【圖式簡單說明】 圖1為傳統成像設備結構示意圖。 圖2為第一較佳實施方式之成像設備的結構示意圖。 圖3為第二較佳實施方式之成像設備的結構示意圖。 圖4為第三較佳實施方式之成像設備的結構示意圖。 圖5為第四較佳實施方式之成像設備的結構示意圖。 11 200949426 圖6為第五較佳實施方式之成像設備的結構示意圖。 圖7為第六較佳實施方式之成像設備的結構示意圖。 【主要元件符號說明】 成像設備 20、30、50 ' 70、90、91、99 - 第一攝像裝置 301、303、305、307、309 . 第二攝像裝置 302、304、306、308 攝像裝置 10 空隙 104 取像範圍 ® 半透半反射透鏡 反射鏡 第一組反射鏡 第二組反射鏡 第三攝像裝置 第四攝像裝置 第五攝像裝置 φ 第三組反射鏡 102、311、322、333 250 直角三稜鏡 950 550 第一組三稜鏡 951 551 第二組三稜鏡 952 552 間隔 470 40卜 404 ' 407 402 ' 405 ' 408 403 ' 406 > 409 450 第四組反射鏡 460 12200949426 IX. Description of the Invention: [Technical Field] The present invention relates to the field of optical imaging, and more particularly to an imaging apparatus based on a complex imaging apparatus. - [Prior Art] At present, in order to capture the overall and detailed image of an object, the entire array of cameras can be arranged together, and the image capturing and image processing, that is, the so-called array image, can be performed at the same time. As shown in Fig. 1, a conventional image forming apparatus 20 includes a plurality of image pickup apparatuses 10, and the plurality of image pickup apparatuses 10 are arranged in a row while photographing an object 200 to be photographed. If the image pickup apparatus 10 is far from the object 200 to be photographed, the image pickup range 102 is large, the image pickup apparatus 10 is closer to the object 200 to be photographed, and the image pickup range 102 is smaller. In general, the size of the image capturing range 102 determines the resolution of the image taken, that is, the larger the image capturing range 102 is, the worse the resolution of the image is taken, and the smaller the image capturing range 102 is, the higher the resolution is. When the image capturing range 102 is large and the distance between the image pickup devices 10 is wide, the arrangement of the image pickup device 10 is less problematic. However, because of the accuracy of the shooting accuracy, a high resolution is often required. At this time, the imaging device 10 is closer to the object 200 to be photographed, and the distance between the imaging devices 10 is limited by the size of the imaging device 10 and cannot be shortened. A gap 104 may occur between the image capturing ranges of the respective image pickup apparatuses 10, that is, a complete image of the current position of the object 200 to be photographed cannot be simultaneously obtained. SUMMARY OF THE INVENTION In view of the above, it is necessary to provide an image forming apparatus that can obtain a complete and high-precision image of an object to be photographed. 5 200949426 An imaging apparatus comprising a plurality of imaging devices for simultaneously capturing an image of a captured object. The plurality of imaging devices are at least divided into two groups, the imaging device further comprising an optical component. The optical component is located in at least one group of imaging devices The light path between the objects being photographed is used to change the direction of propagation from the light of the object being photographed, and the group of imaging devices image the object to be photographed by the optical element. - The above-mentioned image forming apparatus uses an optical element to change the direction of propagation of part or all of the light from the object to be photographed, so that the plurality of image pickup apparatuses which are originally required to be arranged in a row can be dispersed. At the same time, gaps can be left between the image capturing ranges of the cameras in the same row 'because these gaps are exactly filled by the image capturing range of other rows of camera devices', thus effectively solving the size limitation of the camera device. The problem of a complete image cannot be obtained', thereby obtaining a complete and high-precision image of the object being photographed. [Embodiment] Please refer to Fig. 2', which is a schematic structural view of an image forming apparatus 3A of the first preferred embodiment. The imaging device 30 includes a plurality of first imaging devices 301, 303, 305, 307, 309', and a plurality of second imaging devices 3, 2, 304, 306, 308, elongated transflective lenses 250. The plurality of first imaging devices 301, 303, 305, 307, and 309 are arranged in a row and the image capturing directions are the same, and are referred to as: the first row of image capturing devices. The plurality of second camera units 302, 304, 306, and 308 are also arranged in a row and the image capturing directions are the same, which is hereinafter referred to as the second row of image capturing devices. The first row of image pickup devices and the second row of image pickup devices are parallel to each other and the image taking directions are perpendicular to each other. The strip-shaped transflective lens 250 is parallel to the first row of camera devices and the second row of camera devices' and is located at the intersection of the image capturing directions of the first row of the camera device and the second row of camera devices. The lens 250 is at an angle of 45 degrees with respect to the image capturing directions of the first row of image pickup devices and the second row of image pickup devices. In the direction of simultaneously perpendicular to the first row of camera devices and the second row of camera devices, the plurality of first camera images 301, 303, 305, 307, 309 of the first row of camera devices and the plurality of second row camera devices - The second camera devices 302, 304, 306, and 308 are alternately disposed. Thus, the first row of image pickup devices respectively take images from the object 2 〇〇 and ray through the transflective lens 250. The second row of camera devices respectively captures light from the object 200 being photographed and reflected by the transflective lens 250. Since the first row of image pickup devices and the second row of image pickup devices are arranged in parallel and alternately with each other, the image capturing range 311 of the first row of image capturing devices and the image capturing range 322 of the second row of image capturing devices are also arranged in a row and alternately arranged. Compared with the prior art, the imaging device 30 divides the plurality of imaging devices (3〇1 to 309) which are originally required to be arranged in a row into two rows of imaging devices which are arranged in a staggered manner by using the transflective lens 250, and strives for the imaging devices. space. Moreover, a gap can be left between the multiple image capturing ranges of each row of camera devices, because these gaps can be filled by the image capturing range of another row of camera devices, thus effectively solving the size limitation of the camera device. The problem of a complete image cannot be obtained, so that a complete and high-precision image of the object being photographed can be obtained. Subsequent optical detection of the object 200 can be achieved by image analysis or used for other purposes. In the present embodiment, the transflective lens 250 serves as an optical element that changes the direction of light propagation from the object 200 to be photographed, and is an independent optical element. In other embodiments, the transflective lens 250 may also be composed of a plurality of 200949426 transflective lenses. Each transflective lens corresponds to one camera. Please refer to FIG. 3, which is a schematic structural view of the image forming apparatus 5A of the second preferred embodiment. The difference between the imaging device 50 and the imaging device 3 shown in FIG. 2 is that the imaging device 50 replaces the semi-transparent lens 250' in the imaging device 30 with the first mirror and the second The row of imaging devices are arranged in parallel and oppositely, and the plurality of first imaging devices 301, 303, 305, 307, 309 of the first row of imaging devices and the second row of imaging devices and the plurality of second imaging devices of the device are arranged in the image capturing direction of the two 302, 304, 306, and 308 are alternately set. The plurality of mirrors 550 are arranged in a row and are parallel to the first row of camera devices and the second row of camera devices and are located therebetween. The plurality of mirrors 550 are divided into two groups: a first group of mirrors 551 and a second group of mirrors 552, and the mirrors 550 of the first group of mirrors 551 and the second group of mirrors 552 are alternately arranged to respectively correspond to the first The row of imaging devices corresponds to the second row of imaging devices. The reflecting faces of the first group of reflecting mirrors 551 face the first row of image pickup devices' and are at an angle of 45 degrees with respect to the image capturing direction of the first row of image pickup devices. The reflecting surface of the second group of mirrors 552 faces the second row of image pickup devices' and is at an angle of 45 degrees with the image capturing direction of the second row of image pickup devices. Thus, the first row of image pickup devices respectively take images by the light reflected from the first object mirror 551 from the object 20 to be photographed. The second row of camera devices utilizes light from the object being photographed 200 and reflected by the second set of mirrors 552, respectively. Similarly, since the parallel and staggered arrangement of the first row of imaging devices and the second row of imaging devices is such that the image capturing range 311 of the first row of image capturing devices and the image capturing range 322 of the second row of image capturing devices are arranged in a row and alternately arranged, It also solves the problem that the complete image cannot be obtained due to the limitation of the size of the camera. 8 200949426 Thereby, it is possible to obtain a complete and high-precision image of the object being photographed. Please refer to FIG. 4, which is a schematic structural view of an image forming apparatus 70 of a third preferred embodiment. The difference between the imaging device 70 and the imaging device 50 shown in Fig. 3 is that the imaging device 70 has removed the first group of mirrors 551. Correspondingly, the image capturing direction of the first row of image capturing devices becomes perpendicular to the image capturing side of the second row of image capturing devices, so that the object to be photographed 200 is directly imaged by the interval between the second group of mirrors 552 Thus, the optics of the imaging device 70 can be reduced. Please refer to FIG. 5, which is a schematic diagram of the structure of the image forming apparatus 90 of the fourth preferred embodiment. The difference between the imaging device 90 and the imaging device 50 shown in Fig. 3 is that the imaging device 90 replaces the complex mirror 550 in the imaging device 30 with a plurality of right angle triangular prisms 950. The complex right angle three 稜鏡 950 is also divided into two groups: a first set of triangular prisms 951 and a second set of three 稜鏡 952, the positional relationship of which is the same as that of the complex mirror 550, and will not be described again. All of the right-angled faces of the right-angled 稜鏡950 are perpendicular to the orientation direction of the corresponding camera device, so that the light rays from the object 200 are reflected to the first row of cameras and the second by the reflection characteristics of the bevel of the right-angled prism 950, respectively. On the camera. The reason why the present embodiment adopts a right angle three 950 is because the three 950 is easier to fix at the time of assembly. Referring to Fig. 6, which is a schematic view showing the structure of the image forming apparatus 91 of the fifth preferred embodiment, the image forming apparatus 91 is different from the image forming apparatus 90 shown in Fig. 5 in that the image forming apparatus 91 has removed the first group of prisms 951. Correspondingly, the image capturing direction of the first row of image capturing devices becomes perpendicular to the image capturing direction of the second row of image capturing devices, so that the object to be photographed 200 is directly imaged by the interval between the second group of three turns 952, This can reduce the optics of the imaging device 91. 9 200949426 Under special circumstances, if the resolution of the image to be photographed is very high, there may still be a gap between the image capturing ranges when the two rows of camera devices are in close proximity, then three or more rows of camera devices are required to simultaneously capture images. The following is a detailed description of three rows. Please refer to FIG. 7, which is a schematic diagram of the structure of the image forming apparatus 99 of the sixth preferred embodiment. The image forming apparatus 99 has three rows of image pickup devices: a plurality of third image pickup devices 401, 404, 407', a plurality of fourth image pickup devices 402, 405, and 408, and a plurality of fifth image pickup devices 403, 406, and 409. The plurality of third cameras 401, 404, and 407 are arranged in a row and the image capturing directions are the same, which is hereinafter referred to as a third row of image pickup devices. The plurality of fourth camera devices 402, 405, and 408 are arranged in a row and the image capturing directions are the same, which is hereinafter referred to as a fourth row of image capturing devices. The plurality of fifth imaging devices 403, 406, and 409 are also arranged in a row and the image capturing directions are the same, which is hereinafter referred to as: the fifth row of image capturing devices. The three rows of image pickup devices are parallel to each other, and the third row of image pickup devices are disposed opposite to the fourth row of image pickup devices, and the image pickup directions of the fifth row of image pickup devices are perpendicular to the image pickup directions set by the third row of image pickup devices and the fourth row of image pickup devices. The imaging device 99 also includes a third set of mirrors 450, a fourth set of mirrors 460. The third group of mirrors 450 and the fourth group of mirrors 460 are arranged in a row and are parallel to the third row of camera devices, the fourth row of camera devices, and the fifth row of camera devices, and are located in the third row of camera devices and fourth Between the camera units. The plurality of mirrors of the third set of mirrors 450 and the fourth set of mirrors 460 are alternately arranged and two or two sets each having a spacing 470 therebetween. The third row of images is taken. The object of the object to be photographed 200 is taken by the third group of mirrors 450, and the image of the object to be photographed 200 is taken by the fourth group of mirrors 460. The fifth row of photographs is 200949426. The interval 470 directly captures an image of the object 2 being photographed. Thus, the imaging ranges of the third row of imaging devices, the fourth row of imaging devices, and the fifth row of imaging devices are also arranged in a row and alternately arranged. As can be seen from the first to sixth embodiments listed above, the original principle is to use optical elements to change the portion or all of the light from the object 2 to be photographed, by means of reflection, transmission or even refraction. For one or more rays that are different from the direction in which the original light is propagating, then the camera device that needs to be arranged in a row can be divided into two or more groups or even more dispersed multiple cameras, for the camera device. The space. At the same time, gaps can be left between the image capturing ranges of the cameras in the same row, because these gaps can be filled by the image capturing range of other rows of camera devices, so that the size limitation of the camera device can be effectively solved. The problem of obtaining a complete image is not obtained for the month b, thereby obtaining a complete and high-precision image of the object being photographed. It should be understood by those skilled in the art that the above-described embodiments are merely illustrative of the invention and are not intended to limit the invention as set forth herein. Appropriate changes and variations are intended to fall within the scope of the invention. [Simple description of the drawing] Fig. 1 is a schematic structural view of a conventional image forming apparatus. 2 is a schematic structural view of an image forming apparatus of the first preferred embodiment. 3 is a schematic structural view of an image forming apparatus of a second preferred embodiment. 4 is a schematic structural view of an image forming apparatus of a third preferred embodiment. Fig. 5 is a schematic structural view of an image forming apparatus of a fourth preferred embodiment. 11 200949426 FIG. 6 is a schematic structural view of an image forming apparatus of a fifth preferred embodiment. Fig. 7 is a schematic structural view of an image forming apparatus of a sixth preferred embodiment. [Description of main component symbols] Imaging device 20, 30, 50' 70, 90, 91, 99 - First imaging device 301, 303, 305, 307, 309. Second imaging device 302, 304, 306, 308 Imaging device 10 Void 104 Image capturing range ® Transflective lens mirror First group of mirrors Second group of mirrors Third camera device Fourth camera device Fifth camera device φ Third group of mirrors 102, 311, 322, 333 250 Right angle三稜鏡950 550 The first group of three 稜鏡 951 551 The second group of three 稜鏡 952 552 interval 470 40 404 '407 402 ' 405 ' 408 403 ' 406 > 409 450 fourth group of mirrors 460 12