.201140042 六、發明說明： 【發明所屬之技術領域】 本發明有關於一種檢査形成於基板等的圖案之圖案檢 査方法'圖案檢查裝置及圖案檢查裝置用攝像頭。 【先前技術】 要檢査如電漿顯示面板或液晶般具有微細圖案的基板 的圖案，以往使用圖14的圖案檢查裝置。 此圖案檢查裝置之結構爲，利用由攝影機64與光學透 鏡系統65構成的攝像頭66，取入被檢查物63的圖案D。 控制部67根據由攝影機64的攝像元件68所得到的信號， 控制光學透鏡系統65與攝像元件68的距離。 此習知的圖案檢查裝置係處理經由攝影機64所取入 的圖案D的數位資料而檢測出被檢查物63的圖案D的缺 陷。其代表性的處理方法有以下方法：比較圖案D無缺陷 下的資料與利用攝像頭66取入的被檢查物63的資料，以 發琪圖案D缺陷。此方法雖然處理簡單，但有攝像系統的 倍率不確定造成資料的比較困難的課題。 爲了克服此課題，有一種鄰接比較方法：比較利用攝 像頭66取入的被檢查物63的資料與鄰接或幾周期前或後 的圖案，找出不是周期性的部分，將其判定爲缺陷。此爲 利用被檢查物6 3的圖案D是周期性之情況的方法。 此外，在使用CMOS元件、CCD元件或MOS元件作爲 攝像元件68時，有攝像元件68的元件單元尺寸與被檢査 201140042 物63的圖案間距不適合致使產生測量誤差的情形。 作爲消除此測量誤差的方法，有專利文獻1所記載的 方法。此專利文獻1所記載的方法係下述方法：在光學透 鏡系統所得之圖案在固態攝像元件上的投影像方面，以最 小檢測缺陷尺寸爲單元尺寸，以整數個單元包含於1個間 距內的方式，在控制部67設定光學透鏡系統的倍率。 然而，即使是專利文獻1所記載的方法，要大面積地 檢查更微細的圖案，也需要時間，檢查上需要許多費用。 因此，一般採用以下方式：使用複數個攝像單元作爲攝像 頭，而以分割被檢查物的區域的方式進行拍，藉以在短時 間內使圖案之取入完成。此處，各攝像單元具有攝影機、 及設於被檢查物與攝影機之間的光學透鏡系統。 [先前技術文獻] [專利文獻] [專利文獻1]特開2003 - 329609號公報 【發明內容】 [發明欲解決之課題] 要例如如專利文獻1所記載的方法般使用複數個攝像 單元’在1個架台上搭載複數個攝像單元比起全部獨立地 設置，更能簡化檢查裝置。 然而’若在1個架台上搭載複數個攝像單元，則有需 要個別將複數個攝像單元的焦點對準於1片被檢查物的表 面。即’各攝像單元每一者皆需要用以使各攝像單元相對 201140042 於被檢查物獨立垂直（Z軸方向）地移動的驅動部。 本發明解決此等以往的課題，目的在於提供一種可簡 潔地實現複數個攝像單元之對焦的結構的圖案檢查方法、 圖案檢查裝置及圖案檢查裝置用攝像頭。 [解決課題之手段] 用以解決前述課題的本發明的圖案檢查裝置，具備： 攝像頭，其掃描周期地並排設置於被檢查物表面的圖案， 同時搭載有攝像元件與光學透鏡系統單元；及控制裝置， 其與隔開一定周期的部分比較，檢查前述圖案的缺陷.，該 圖案檢查裝置之特徵在於：前述攝像頭具有驅動部，該驅 動部使固定有複數個攝像單元的架台相對於前述被檢查物 的表面在接近離開方向上可動，前述攝像單元由具有攝像 元件的攝像元件單元、及在前述接近離開方向上可動的光 學透鏡系統單元構成，前述控制裝置以前述光學透鏡系統 單元的倍率Μ成爲以下範圍的方式，使前述光學透鏡系統 單元移動，將前述各攝像單元的焦點對準於前述被檢査物 的表面，檢測前述圖案的缺陷。 C(N - ΔΝ)/Ρ< M< C(N + ΔΝ)/Ρ 其中，C:前述攝像元件的元件間距，P:前述圖案的 間距，N :前述圖案的投影像間距內的前述攝像元件的元件 數，ΔΝ :前述投影像的容許元件。 此外，本發明的圖案檢査裝置用攝像頭係利用複數個 攝像單元拍攝並排設置於被檢查面的圖案，該圖案檢查裝 201140042 置用攝像頭之特徵在於具備：相對於前述被檢査面在垂直 方向上可動的架台、及安裝於前述架台上的複數個攝像單 元，前述攝像單元由攝像元件及在前述垂直方向上可動的 光學透鏡系統單元所構成。 此外，本發明的圖案檢查方法，其利用搭載有攝像元 件與光學透鏡系統單元的攝像單元掃描周期地並排設置於 被檢查物表面的圖案，與隔開一定周期的部分比較，檢查 前述圖案的缺陷，該方法之特徵在於：以前述光學透鏡系 統單元的倍率Μ成爲以下範圍內的方式，使前述光學透鏡 系統單元移動，將前述各攝像單元的焦點對準於前述被檢 查物的表面後，檢測前述圖案的缺陷。 C(N - ΔΝ)/Ρ< M< C(N + ΔΝ)/Ρ 其中，c:前述攝像元件的元件間距，P:前述圖案的 間距，N :前述圖案的投影像間距內的前述攝像元件的元件 數，ΔΝ :前述投影像的容許元件。 [發明之效果] 依據本發明，可提供一種可簡潔地實現複數個攝像單 元對焦的結構的圖案檢查方法、圖案檢查裝置及圖案檢查 裝置用攝像頭。 【實施方式】 以下，一面參閱圖1〜圖13，一面說明本發明的各實 施形態。 (實施形態1) 201140042 圖1爲說明使用於本發明實施形態1的圖案檢查裝置 的攝像頭結構與原理的槪略結構圖》 此攝像頭100用於讀取在載置於移動台1上的被檢查 物2之表面所形成的圖案3。此攝像頭100在架台4上固 定有3個攝像單元5a、5b、5c。 此外，被檢査物2爲電漿顯示面板或液晶面板等顯示 面板的基板。更具體而言，顯示面板係在前面板與背面板 之間空出間隙而貼合者。電漿顯示面板的情況係將其內部 的空間分隔成各顯示色的放電區域。液晶面板的情況係在 其內部的空間塡充液晶。在前面板或背面板上形成有前述 圖案3,並對於貼合前的前面板或背面板的圖案實施檢査》 控制裝置6以可在將焦點對準於圖案3的狀態下拍攝 被檢查物2的方式調整攝像單元5a、5b、5c。此控制裝置 6是在裝配時執行圖3所示的裝配調整流程圖，詳細後述 之。 攝像單元5 a由攝像元件7 a、及光學透鏡系統單元8 a 所構成’該光學透鏡系統單元8 a配置於攝像元件7 a與被 檢查物2之間，可相對於被檢查物2的表面在接近離開方 向（以下稱爲Z軸方向）上垂直地移動。 攝像單元5b由攝像元件7b、及光學透鏡系統單元8b 所構成’該光學透鏡系統單元8b配置於攝像元件7b與被 檢查物2之間’可在z軸方向上垂直地移動。 攝像單元5 c由攝像元件7 c、及光學透鏡系統單元8 c 201140042 所構成，該光學透鏡系統單元8c配置於攝像元件7c與被 檢查物2之間，可在Z軸方向上垂直地移動》 此外，爲了簡便說明，在圖1中只記載必要最小限度 的部件。 ' 同時，爲了得到必要的讀取特性，光學透鏡系統單元 8a、8b、8c也有複數片透鏡群的結構或使用非球面透鏡等 的結構。圖式省略用以使光學透鏡系統單元8a、8b、8c移 動的驅動系統、或用以控制驅動的控制裝置。 作爲攝像元件7a ' 7b、7c，使用CMOS元件或CCD元 件、MOS元件等的半導體的固態攝像元件。此等元件中有 直線型或區域型，但在本發明，可使用直線型、區域型的 任~型。 藉由被檢查物2與架台4相對移動，安裝於此架台4 上的各攝像單元5a、5b、5c分別掃描被檢查物2的被分配 的區域而讀取圖案3。在本實施形態係藉由被檢查物2與 架台4在圖1之與紙面垂直的方向上相對移動，進行被檢 査物2的X軸方向的掃描。 圖2(a)、圖2(b)、圖2(c)爲分別顯示圖1的具體例的 圖。 架台4的兩側係在由導承9 a、9 b所定位的狀態下被以 相對於被檢查物2的表面在Z軸方向上滑動自如的方式支 撐。利用安裝於固定台12上的主馬達10驅動與形成於此 架台4上的螺絲孔旋緊的螺旋軸1 1旋轉，驅動架台4相對 201140042 動 4 攝 、 Z 元 元 光 置 5 a 同 旋 8b 旋 滑 透 於被檢査物2的表面在Z軸方向上滑動。此處，Z軸驅 部30係由螺旋軸11與主馬達10等構成。 在沿著與X軸方向正交的Y軸方向而配置的架台 上，以預定間隔在Y軸方向上固定有具有攝像元件7a的 像元件單元1 3 a、具有攝像元件7b的攝像元件單元1 3b 具有攝像元件7 c的攝像元件單元1 3 c。 而且，在架台4上，以相對於被檢查物2的表面在 軸方向上垂直滑動自如的方式安裝有光學透鏡系統單 8a、8b、8c。再者，在使光軸與攝像元件單元13a '攝像 件單元13b、攝像元件單元13c —致的狀態下安裝此等 學透鏡系統單元8a、8b、8c。 光學透鏡系統單元8 a係單側藉在Z軸方向上延伸設 的導承1 4a而作定位，並與形成於另—側的螺絲孔旋緊 使得軸心被支撐於與導承1 4a平行的第1螺旋軸1 5a上 利用安裝於架台4上的第1馬達16a驅動第1螺旋軸1 旋轉’而在Z軸方向上驅動光學透鏡系統單元8a滑動。 樣地’利用安裝於架台4上的第2馬達16b驅動第2螺 軸15b旋轉’而在z軸方向上驅動光學透鏡系統單元 滑動。利用安裝於架台4上的第3馬達16c驅動第3螺 軸15c旋轉’而在Z軸方向上驅動光學透鏡系統單元8c 動。光學透鏡系統單元8b係藉導承14b而作定位，光學 鏡系統單元8c係藉導承i4c而作定位。 圖3顯示攝像頭1〇〇的裝配時的流程圖。 201140042 首先，在步驟S1，在相對於被檢查物2的平面對準垂 直方向（Z軸方向）的位置的狀態下，將攝像單元5a、5b、 5c固定於架台4上。此時，如圖4所示，各攝像單元5a、. 5b、5c的攝像元件7a、7b、7c含有Z軸方向的1〇〇 μιη左 右的安裝誤差Azl、Δζ2。 在步驟S2，以攝像單元5a的焦點對準圖案3的方式 使主馬達10運轉而使架台4在Z軸方向上移動來作調整。 此處’所謂攝像單元5 a的焦點對準圖案3的狀態係可在攝 像元件7a得到圖案3的對焦點影像的狀態。 在攝像單元5 a的焦點對準時，立即在步驟S 3測量攝 像單元5a的倍率。然後，在步驟S4，判定在步驟S3測量 的倍率是否爲適合圖案的倍率。 在步驟S4判定不是適合的倍率的情況，在步驟S5調 整攝像單元5a的倍率。 反覆步驟S2、S3、S4、S5的程序，判定倍率是否適合 圖案。然後，若在步驟S 4判定爲適合的倍率，則判斷攝像 單.元5a的調整完畢。若攝像單元5a的調整完畢，接著就 執行步驟S 6 » 在步驟S6，以攝像單元5b及攝像單元5c的焦點對準 圖案3的方式進行調整。具體而言，首先，以可在攝像單 元5b的攝像元件7b得到圖案3的對焦點影像的方式使第 2馬達16b運轉而使光學透鏡系統單元8b在Z軸方向上移 動。接著，以可在攝像單元5 c的攝像元件7 c得到圖案3 • 10 - 201140042 的對焦點影像的方式使第3馬達16c運轉而使光學透鏡系 統單元8c在Z軸方向上移動。 如此藉由進行攝像單元5a、5b、5c的調整，可修補各 攝像單元5a、5b、5c在步驟S1所產生的安裝誤差Azl、 Az2。然而，如此進行過調整的情況，各攝像單元5a、5b、 5 c之像的倍率會微妙地不同。即，在本實施形態係使用圖 3所示的調整流程來進行攝像單元的倍率調整與對圖案的 對焦。 此外，本實施形態的攝像頭只移動攝像單元5a、5b、 5c的光學透鏡系統單元8a、8b、8c即可。即，複數個攝像 單元5a、5b、5c共通的架台4係在Z軸方向上驅動的驅動 機構只要1個即可。因此，相較於各攝像單元每一者皆設 置在Z軸方向上驅動的驅動機構的情況，可簡化結構。由 於結構變得簡單，所以驅動機構的驅動精度良好，驅動機 構的成本也變得便宜。 圖5(a)、圖5 (b)顯示關於本實施形態的攝像單元的結 構與性能的說明圖。由於攝像單元5 a、5 b、5 c的構造相同， 所以此處就攝像單元5b進行說明。 圖5(a)爲攝像單元5b的槪略結構圖。圖5(b)爲顯示使 攝像元件7b與光學透鏡系統單元8b的距離變化的情況的 光學透鏡移動量與焦點移動量之關係的圖。再者，圖5(b) 的圖表爲在固定攝像元件7b的狀態下使光學透鏡系統單 元8 b移動而進行測量的圖表。 -11- 201140042 在本實施形態’爲透鏡公式的1/F=1/L1+1/L2、 M=L2/L1滿足以下的條件： F:光學透鏡系統單元8b的焦點距離=15mm L1·光學透鏡系統單兀8b與被檢查物2的距離==20mm (移動量〇時） L2:光學透鏡系統單元8b與攝像元件7b的距離= 6〇mm (移動量0時） M:倍率=3 (移動量0時） 在以上之關係中，在只使光學透鏡系統單元8b移動的 情況，光學透鏡移動量與焦點移動量大致相同。 圖6中顯示光學透鏡移動量與倍率的變化。此外，圖 7中顯示將ΙΟΟμιη圖案以投影圖案300μιη投影於攝像元件 7b上時的伸展/收縮的變化量。 根據此等圖可得知：若使光學透鏡系統單元8b移動到 〇· 1mm上方（Z軸方向），則由圖5(b)得知，焦點從被檢查物 2的表面在Z軸方向上移動僅約0.1mm。而且，若焦點僅 在Z軸方向上移動約0.1mm，則由圖7得知，ΙΟΟμιη的投 影圖案從300μιη僅收縮約0.6μιη。 —般在裝配攝像頭100時，產生±50 μιη左右的對架台 4的安裝誤差。本實施形態係可使光學透鏡系統單元8b移 動而消除此所產生的誤差。再者，即使是爲了作消除而使 光學透鏡系統單元8b移動最大ΙΟΟμιη的情況，因倍率的 變化而產生的圖案3的伸展收縮相對於3 ΟΟμιη的圖案也爲 -12- 201140042 0.6 μηι。 接著，就在本實施形態下檢查圖案是否沒有問題進行 硏究。以下，就3 00 μιη圖案的0.6μιη的影響進行說明。 首先，就使用到此爲止所說明過的攝像頭100的圖案 檢査裝置進行說明。 首先，圖案檢查裝置利用攝像頭100掃描周期性地排 列於平面狀的被檢查物表面的圖案而進行數位資料化。然 後，以控制裝置6比較隔開一定周期的部分的圖案資料與 所操作的圖案，以檢測圖案的缺陷。 與在圖案資料內不同的部位的圖案比較檢查的方法 (以下稱爲比較檢査法）也被專利文獻1所記載的技術使 用。圖案檢查裝置由於使用固態攝像元件作爲攝像元件， 所以將圖案的一間距份投影於攝像元件時，需要圖案的一 間距份確實地包含於整數個攝像單元中。這是因爲若圖案 的一間距份未包含於整數個攝像單元中，則在比較資料 時，即使是一周期份的圖案也會被判定爲在邊緣部不同， 而產生錯誤檢測。因此，比較檢查法要比較檢查使光學透 鏡系統單元的倍率爲最佳時所取得的資料。 雖然爲了對焦而各攝像單元5a、5b、5c的倍率稍微不 同，但本實施形態的攝像頭1 0 0滿足比較檢查法的比較檢 査所需的倍率的容許値。 接著，在圖8說明本實施形態攝像元件7b上的300μιη 的圖案像依爲了對焦而產生的倍率變化而改變0.6μιη之關 -13- 201140042 係。 如圖8所示，本實施形態的攝像元件7b以單元尺寸爲 ΙΟμπν。在圖1所說明的ιοομπ!的被檢查物2的圖案3係利 用最佳倍率的光學透鏡系統單元8b而被圖案投影於單元 尺寸爲ΙΟμιη的單元30個上以作爲300μιη的投影像17。 如圖8所示，由於本實施形態的單元尺寸爲ΙΟμιη，所 以0.6 μιη的不足量相對於單元爲6%。 要在比較檢査法不影響到檢測結果，就是對焦而產生 的投影像相對於單元的超出量可容許到幾％。再者，單元 的超出量被變換爲倍率的容許範圍。需要決定光學透鏡系 統單元8b的移動量爲此倍率的容許範圍內。 在本實施形態，如以下設定符號的情況，攝像單元5 b 的光學透鏡系統單元8b的倍率的容許量（容許倍率Μ)需要 控制在下述式（1)的範圍內。 C(N - ΔΝ)/Ρ< M< C(N + ΔΝ)/Ρ ...... (1) 此外，C :攝像元件7b的元件間距，P :圖案3的間距， N:投影像17的間距內的攝像元件7b的元件數（整數），ΔΝ: 投影像1 7的容許量（元件）° 圖9顯示到控制裝置6導出攝像單元5a' 5b、5c的安 裝誤差的容許量爲止的一連串的流程圖。 此處，設元件間距C = 1 0、間距P = 1 0 0、元件數N = 30。容許量ΔΝ成爲投影圖案的容許超出份幾單元份的單 位。 -14- 201140042 首先，在步驟S11，根據被檢查對象2所要求的檢查 精度等決定ΔΝ的容許超出份。例如，設被容許的超出量 爲6% ，即AN=0.06單元份。 其次，在步驟S12,將超出容許量ΔΝ代入上述式（1)， 導出容許倍率Μ。若應用於以圖7說明之例，則容許倍率 Μ成爲以下的式（2)的條件。 2.994 < Μ < 3.006 ......(2) 若導出容許倍率Μ，則在步驟S13決定光學透鏡系統 單元8b、8c的移動容許量。 光學透鏡系統單元8b、8c的移動量與倍率之關係取決 於攝像單元5a、5b' 5c的光學設計。基於此倍率的移動容 許量在步驟S14成爲各攝像單元5a、5b、5c的安裝誤差容 許量。 由此等之關係得知，在本實施形態，光學透鏡系統單 元8 b、8 c可移動到0. 1 mm。因此，焦點位置可使其移動到 0.1mm，修補安裝誤差±50μιη，可確認即使將各攝像單元 5a、5b、5c的焦點對準於被檢査物2的表面也無影響。即， 可確認在本實施形態的結構所得到的圖案資料適合比較檢 査法。 以上說明的攝像單元5b的結構爲基本的結構。然而， 藉由光學透鏡設計，可設計成更適當的結構。以下’就其 適當結構的條件，使用攝像單元5少進行說明。 首先，在本實施形態的適當結構的最小條件’固定攝 -15- 201140042 像元件7b，使光學透鏡系統單元8b移動，進行攝像 5b的對焦。此時，因光學透鏡系統單元8b與攝像元ί 的距離變化，而攝像單元5b的倍率變化。然而，如前 此倍率的變化在比較檢查法微小到沒有影響的程度， 可在適合比較檢查法的倍率容許量內對焦。 作爲滿足此種條件的光學透鏡設計之一例，有光 鏡系統單元8b與攝像元件7b的距離更加長的設計。 設計如下：即使各攝像單元5a、5b、5c爲同等倍率， 透鏡系統單元8b與攝像元件7b的距離、光學透鏡系 元8c與攝像元件7c的距離亦更長。這是因爲光學透 統單元8b與攝像元件7b的距離、光學透鏡系統單元' 攝像元件7c的距離越長，使光學透鏡系統單元8b與 元件7b的距離變化時的倍率的變化量越小。此外，由 光學透鏡系統單元8c與攝像元件7c的距離變化時的 的變化量變小，所以在倍率的變化容許量內的光學透 統單元8b、8c的移動容許距離變長。 藉由依此種條件設計’即使在攝像單元5a、5b、 此的安裝精度不細緻的情況，也可修補安裝誤差。此 在需要更縮小倍率變化容許量的範圍的情況’即必須 小攝像單元5a、5b、5c間的倍率誤差的情況’藉由進 種光學透鏡設計亦可應付。 此外，將圖案3投影於攝像π件7a、7b、7c上時 攝像單元5a、5b、5c的焦點深度的硏討也重要。即’ 單元 牛7b 述， 所以 學透 最好 光學 統單 鏡系 8c與 攝像 於使 倍率 鏡系 5c彼 外， 更縮 行此 的各 雖然 -16- 201140042 若焦點深度深，則也沒有對焦的問題，但焦點深度取 光學透鏡系統單元8a、8b、8c的數値孔徑即NA。爲 將圖案3投影於攝像元件7a、7b、7c上時的投影像更 精細化，需要以光學透鏡系統單元8a、8b、8c的NA 的方式進行設計。 要提高光學透鏡系統單元的NA，最好是攝像單元 點深度淺的設計。這是因爲雖然若焦點深度深，則沒 焦的問題，但爲了投影像的高精細化，焦點深度必然變 此外’在焦點深度深的情況，由於到在圖案背後的構 爲止取入作爲圖案投影像，所以有時無法正確的拍攝 此種觀點也是，攝像單元的焦點深度需要變淺。在本 形態，最好攝像單元的焦點深度爲20 μιη以下。 再者’本發明也有省略通常驅動各攝像單元的驅 構或攝像單元內的驅動機構等的特徵。因此，被認爲 不是檢查裝置，也可適用於高速讀取精密圖像的掃描 此外’依據此圖案檢查裝置，則有省略驅動各攝 元的驅動機構或攝像單元內的驅動機構等的特徵β因 可廉價地製造圖案檢査裝置。 (實施形態2) 圖10(a)爲說明本發明實施形態2的圖案檢查裝置 用的攝像"頭的結構與原理的槪略結構圖。圖1 〇(b)爲圖 的A部的放大圖。 決於 了使 加高 提高 的焦 有對 淺。 造物 。由 實施 動機 即使 裝置 像單 此， 所使 10(a) -17- 201140042 本實施形態2的攝像頭200讀取形成於移動台1上所 載置的被檢查物2表面的圖案3。 架台24被支撐爲相對於被檢查物2的表面在z軸方向 上被滑動自如。利用安裝於固定台12上的主馬達1〇，驅 動與形成於此架台24的螺絲孔旋緊的螺旋軸11旋轉，驅 動架台24相對於被檢査物2的.表面在Z軸方向上滑動。 在本實施形態，在架台24上固定有4個攝像單元25 a、 25b ' 25c 、 25d ° 爲了可在將焦點對準於圖案3的狀態下拍攝被檢查物 2’此等攝像單元25a〜25d在對架台24的裝配時已作調整。 攝像單元25a由攝像元件單元26a、及光學透鏡系統單 元28a所構成。攝像元件單元26a具備攝像元件7a，可相 對於被檢查物2的表面在Z軸方向上垂直地移動。光學透 鏡系統單元28a配置於攝像元件單元26a與被檢査物2之 間，可相對於被檢查物2的表面在Z軸方向上垂直地移動。 此外，在本實施形態，攝像元件單元26a與光學透鏡系統 單元28a係被利用可調整彼此距離的驅動部27a，而以成爲 1個單元的方式連結。攝像元件單元26a、光學透鏡系統單 元28a透過驅動部27a安裝於架台24上。 攝像單元25b由攝像元件單元26b、及光學透鏡系統 單元28b所構成。攝像元件單元26b具備攝像元件7b，可 相對於被檢查物2的表面在Z軸方向上垂直地移動。光學 透鏡系統單元28b配置於攝像元件單元26b與被檢查物2 -18 - 201140042 之間，可相對於被檢查物2的表面在Z軸方向上垂直地移 動。攝像元件單元26b與光學透鏡系統單元28b被利用可 調整彼此距離的驅動部27b以成爲1個單元的方式連結。 攝像元件單元26b與光學透鏡系統單元28b係透過驅動部 27b而被安裝於架台24上。 攝像單元25c由攝像元件單元26c、及光學透鏡系統單 元28c所構成。攝像元件單元26c具備攝像元件7c，可相 對於被檢查物2的表面在Z軸方向上垂直地移動。光學透 鏡系統單元28c配置於攝像元件單元26c與被檢查物2之 間，可相對於被檢查物2的表面在Z軸方向上垂直地移動。 攝像元件單元26c與光學透鏡系統單元28c係被利用可調 整彼此距離的驅動部27c而連結。攝像元件單元26c與光 學透鏡系統單元28c係透過驅動部27c而被安裝於架台24 上。 攝像單元25d由攝像元件單元26d、及光學透鏡系統 單元28d所構成。攝像元件單元26d具備攝像元件7d，可 相對於被檢查物2的表面在Z軸方向上垂直地移動。光學 透鏡系統單元28d配置於攝像元件單元26d與被檢査物2 之間，可相對於被檢査物2的表面在Z軸方向上垂直地移 動。攝像元件單元26d與光學透鏡系統單元28d係被利用 可調整彼此距離的驅動部27d而連結。攝像元件單元26d 與光學透鏡系統單元28d係透過驅動部27d而被安裝於架 台24上。 201140042 根據檢查對象或攝像單元25a〜25d的光學結構 要求傾斜角度相對於檢查對象的精度高。在此種情 好如圖10(b)所示，攝像單元25a〜25d在攝像元件單 〜26d與驅動部27a〜27d之間安裝調整軸機構29, 軸機構29可在正交的3軸的周圍的橫搖-縱搖 (roll-pitch-yaw)的3方向Ro、Pi、Ya進行傾斜調整 利用形成此種結構，藉由以控制裝置6控制 27a’可調整光學透鏡系統單元28a與攝像元件7a的 同樣地，藉由以控制裝置6控制驅動部2 7 b，可調 透鏡系統單元28b與攝像元件7b的距離。同樣地， 控制裝置6控制驅動部2 7 c，可調整光學透鏡系統單 與攝像元件7c的距離。同樣地，藉由以控制裝置6 動部27d，.可調整光學透鏡系統單元28d與攝像元供 距離。如此，藉由調整光學透鏡系統單元與攝像元 離，可將攝像單元25a〜25d的焦點面調整爲同一面 用單一的Z軸驅動部25使攝像單元25a〜25d同時 此處，Z軸驅動部30以螺旋軸11與主馬達1〇等構 圖11(a)、圖11 (b)、圖11 (c)顯示圖10(a)的具 在利用導承9a、9b將兩側定位的狀態下，沿著 向配置的架台24被支撐爲相對於被檢査物2的表面 方向上滑動自如。在架台24上，以預定間隔在Y軸 固定有攝像單元25a〜25d。 攝像單元25a的攝像元件單元26a係單側藉在 ，有時 況，最 元2 6 a 該調整 i -偏轉 〇 驅動部 I距離。 整光學 藉由以 元28c 控制驅 卜7d的 件的距 ，可使 移動。 成。 .體例》 γ軸方 在Z軸 方向上 Z軸方 -20- 201140042 向上延伸設置的導承34而作定位，並與形成於另一側的螺 絲孔旋緊，使得軸心被支撐於與導承3 4平行的螺旋軸3 6 上。螺旋軸36係被安裝於架台24上的馬達38驅動旋轉， 驅動攝像元件單元26a在Z軸方向上滑動。使光軸與攝像 元件單元26a —致的光學透鏡系統單元28a係單側藉在z 軸方向上延伸設置的導承35而作定位，並與形成於另一側 的螺絲孔旋緊，使得軸心被支撐於與導承3 5平行的螺旋軸 37上。螺旋軸37係被安裝於架台24上的馬達39驅動旋 轉，驅動光學透鏡系統單元28a在Z軸方向上滑動。 攝像單元2 5 b〜2 5 d的情況也和攝像單元2 5 a相同。攝 像單元25b的攝像元件單元26b利用馬達42驅動旋轉螺旋 軸40而被驅動在Z軸方向上滑動。攝像單元25b的光學透 鏡系統單元2 8 b係被利用馬達4 3驅動旋轉螺旋軸4 1而被 驅動在Z軸方向上滑動。 攝像單元25c的攝像元件單元26c係被利用馬達46驅 動旋轉螺旋軸44而被驅動在Z軸方向上滑動。攝像單元 25c的光學透鏡系統單元28c係被利用馬達47而驅動旋轉 螺旋軸45而被驅動在Z軸方向上滑動。 攝像單元25d的攝像元件單元26d係被利用馬達50驅 動旋轉螺旋軸48而被驅動在Z軸方向上滑動。攝像單元 25d的光學透鏡系統單元28d係被利用馬達51驅動旋轉螺 旋軸49而被驅動在Z軸方向上滑動。 (實施形態3) -21 - 201140042 圖12顯不本發明實施形態3的圖案檢查裝置的槪略平 面圖。 在本實施形態3，與實施形態i的架台*或實施形態2 的架台24對應的架台61係藉由使z軸驅動部3〇的主馬達 1〇運轉而在Z軸方向上移動。在架台61上，複數個攝像 單兀被以隔著架台61排成2行的方式安裝。在本實施形態 的架台61上安裝有8個攝像單元62a〜6 2h。其具體的安 裝方法與實施形態1或實施形態2的結構相同，所以說明 省略。 如此藉由在架台61上安裝複數個攝像單元，可將被檢 査物2的檢査區域分成2個區域，因此可將被檢査物2的 移動距離削減爲1行的情況的一半距離。其結果，相較於 實施形態1或實施形態2的結構，檢查速度變快，可縮短 檢查時間。 圖1 3顯示實施形態3的變形例。 在本實施形態3的變形例，相對於架台61，與圖12 所示的結構同樣，配置成8個攝像單元62a、62c、62e、62g 的一行、及攝像單元6 21)、620、62卜6211的另一行的2行。 在圖13中，在使被檢查物2相對於架台61在X軸方向上 移動而實施讀取的情況，攝像單元讀取被檢查物2的 檢查面的區域E1，攝像單元62b讀取被檢査物2的檢査面 的區域E2，攝像單元62c讀取被檢查物2的檢査面的區域 E3，攝像單元62d讀取被檢査物2的檢査面的區域E4。以 -22- 201140042 下同樣地，以攝像單元62e、62f、62g、62h讀取被檢查物 2的檢查面的區域E5、E6、E7、E8的方式，形成錯開攝像 單元62a〜6 2h的位置的交錯配置。藉由形成此種配置，可 利用1次掃描有效地檢査被檢查物2。 作爲上述各實施形態的主馬達1 〇、第1馬達1 6a、第 2 馬達 16b、第 3 馬達 16c' 馬達 38、39、42、43、46、47、 5 0、5 1，可使用步進馬達或伺服馬達。 [產業上之利用可能性] 本發明可利用於電漿顯示面板或液晶面板等顯示面板 的圖案檢查。 【圖式簡單說明】 圖1爲本發明實施形態1的檢査裝置的攝像頭的槪略 結構圖。 圖2(a)爲用以顯示圖1的具體例的槪略正面圖，圖2(b) 爲用以顯示圖1的具體例的槪略側面圖，圖2(c)爲用以顯 示圖1的具體例的槪略上面圖。 圖3爲關於本實施形態1的攝像頭的裝配調整的流程 圖。 圖4爲用以說明複數個攝像頭的安裝誤差的槪略結構 圖。 圖5 (a)爲本實施形態1的攝像單元的槪略結構圖，圖 5(b)爲顯示本實施形態1的光學透鏡移動量與焦點移動量 之關係的圖。 -23- 201140042 圖6爲顯示本實施形態1的光學透鏡的移動量與倍率 之關係的圖。 圖7爲顯示本實施形態1的光學透鏡移動量與投影圖 案的變化量之關係的圖。 圖8爲顯示本實施形態1的投髟圖案與攝像元件的單 元之關係的圖。 圖9爲關於導出本實施形態1的攝像單元的安裝誤差 的流程圖。 圖10(a)爲本發明實施形態2的檢查裝置的攝像頭的槪 略結構圖，圖10(b)爲本實施形態2的攝像頭的主要部分放 大圖。 圖11(a)爲用以顯示圖10的具體例的槪略正面圖，圖 11(b)爲用以顯示圖10(a)的具體例的槪略側面圖，圖ii(c) 爲用以顯示圖10(a)的具體例的槪略上面圖。 圖12爲本發明實施形態3的攝像頭的槪略結構圖。 圖1 3爲本發明實施形態3的攝像頭的變形例的槪略結 構圖。 圖14爲顯示習知的圖案檢查裝置的槪略圖。 【主要元件符號說明】 1 移動台 2 被檢查物 3 圖案 4 ' 24 ' 61 架台 -24- 201140042 5a 、 5b ' 5c 、 25a〜25d 6 2 a 〜6 2 h 6 7 a〜 7c 8 a〜 8c、 28a- '28d 9 a ' 9b、 14a、 14b ' 14c 、34 ' 3 5 10 11' 36、 37 ' 40、4 44、 45、 48、 49 12 13a 、13b 、13 c、 26a 〜2 6 d 15a 〜1 5 c 16a 〜1 6 c 27a 〜27d 29 30 38 ' 39 ' 42、 43、 46、 47、 50、 5 1 E 1 〜E8 100 200 攝像單元 控制裝置 · 攝像元件 光學透鏡系統單元 導承 主馬達 螺旋軸 固定台 攝像元件單元 第1〜第3螺旋軸 第1〜第3馬達 驅動部 調整軸機構 Z軸驅動部 馬達 被檢查物2的檢查面的區域 攝像頭 攝像頭 -25-BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pattern inspection method for inspecting a pattern formed on a substrate or the like, a pattern inspection device, and a camera for a pattern inspection device. [Prior Art] In order to inspect a pattern of a substrate having a fine pattern like a plasma display panel or a liquid crystal, the pattern inspecting apparatus of Fig. 14 has been conventionally used. The pattern inspection device is configured to take in the pattern D of the inspection object 63 by the camera 66 composed of the camera 64 and the optical lens system 65. The control unit 67 controls the distance between the optical lens system 65 and the imaging element 68 based on the signal obtained by the imaging element 68 of the camera 64. The conventional pattern inspection apparatus detects the defect of the pattern D of the inspection object 63 by processing the digital data of the pattern D taken in by the camera 64. A representative processing method is to compare the data of the pattern D without defects with the data of the object 63 to be inspected by the camera 66 to make the pattern D defect. Although this method is simple in processing, there is a problem that the magnification of the imaging system is uncertain and the data is difficult. In order to overcome this problem, there is a method of adjacency comparison: comparing the data of the object 63 to be inspected by the camera head 66 with the pattern before or after the adjacent or several cycles, and finding a portion which is not periodic, and determining it as a defect. This is a method in which the pattern D of the object to be inspected 6 is periodic. Further, when a CMOS element, a CCD element or a MOS element is used as the image pickup element 68, the size of the element unit of the image pickup element 68 and the pattern pitch of the object 63 to be inspected are not suitable for causing a measurement error. As a method for eliminating this measurement error, there is a method described in Patent Document 1. The method described in Patent Document 1 is a method in which a pattern obtained by an optical lens system is projected on a solid-state image sensor with a minimum detection defect size as a unit size, and an integer number of units are included in one pitch. In the mode, the control unit 67 sets the magnification of the optical lens system. However, even in the method described in Patent Document 1, it takes time to inspect a finer pattern over a large area, and a lot of cost is required for inspection. Therefore, generally, a plurality of image pickup units are used as the camera, and the image is divided so as to divide the area of the object to be inspected, so that the pattern is taken in for a short time. Here, each imaging unit has a camera and an optical lens system provided between the object to be inspected and the camera. [PRIOR ART DOCUMENT] [Patent Document 1] Japanese Laid-Open Patent Publication No. JP-A No. 2003-329609. SUMMARY OF THE INVENTION [Problems to be Solved by the Invention] For example, a plurality of imaging units are used as in the method described in Patent Document 1. The mounting of a plurality of image pickup units on one gantry is more simplistic than the installation of the plurality of image pickup units. However, if a plurality of image pickup units are mounted on one gantry, it is necessary to individually focus the plurality of image pickup units on the surface of one object to be inspected. In other words, each of the image pickup units requires a drive unit for moving the respective image pickup units to the inspection object independently and vertically (Z-axis direction) with respect to 201140042. The present invention has been made in view of the above problems, and an object of the invention is to provide a pattern inspection method, a pattern inspection device, and a camera for a pattern inspection device which can realize a configuration in which a plurality of imaging units are directly focused. [Means for Solving the Problem] The pattern inspection device of the present invention for solving the above-described problems includes: a camera in which a pattern is periodically arranged on a surface of an object to be inspected, and an image pickup device and an optical lens system unit are mounted; and control a device for inspecting a defect of the pattern in comparison with a portion separated by a period of time, the pattern inspection device characterized in that the camera has a driving portion that causes a gantry to which a plurality of image pickup units are fixed to be inspected with respect to the foregoing The surface of the object is movable in a direction away from the direction in which the imaging unit is composed of an imaging element unit having an imaging element and an optical lens system unit movable in the approaching and separating direction, and the control device is multiplied by the magnification of the optical lens system unit. In the following manner, the optical lens system unit is moved, the focus of each of the imaging units is aligned on the surface of the object to be inspected, and the defect of the pattern is detected. C(N - ΔΝ)/Ρ < M <C(N + ΔΝ)/Ρ where C: the element pitch of the imaging element, P: the pitch of the pattern, N: the number of elements of the imaging element in the projection image pitch of the pattern, ΔΝ: the projection image Allowable component. Further, the camera for a pattern inspection device according to the present invention is configured to photograph and arrange a pattern arranged on a surface to be inspected by a plurality of imaging units, and the image inspection device 201140042 is characterized in that the camera is provided to be movable in a vertical direction with respect to the inspection surface to be inspected. And a plurality of imaging units mounted on the gantry, wherein the imaging unit is composed of an imaging element and an optical lens system unit movable in the vertical direction. Further, in the pattern inspection method of the present invention, the pattern of the surface of the object to be inspected is periodically arranged by scanning with the image pickup unit on which the image pickup device and the optical lens system unit are mounted, and the defect of the pattern is checked in comparison with a portion separated by a predetermined period. This method is characterized in that the optical lens system unit is moved such that the magnification of the optical lens system unit is within the following range, and the focus of each of the imaging units is aligned with the surface of the inspection object, and then the detection is performed. Defects of the aforementioned pattern. C(N - ΔΝ)/Ρ < M <C(N + ΔΝ)/Ρ where c: the element pitch of the imaging element, P: the pitch of the pattern, N: the number of elements of the imaging element in the projection image pitch of the pattern, ΔΝ: the projection image Allowable component. [Effects of the Invention] According to the present invention, it is possible to provide a pattern inspection method, a pattern inspection device, and a camera for a pattern inspection device which can realize a configuration in which a plurality of imaging units are in focus. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to Figs. 1 to 13 . (Embodiment 1) 201140042 Fig. 1 is a schematic structural view for explaining a structure and a principle of a camera used in a pattern inspecting apparatus according to Embodiment 1 of the present invention. This camera 100 is used for reading an inspected image placed on the mobile station 1. The pattern 3 formed by the surface of the object 2. This camera 100 has three imaging units 5a, 5b, and 5c fixed to the gantry 4. Further, the inspection object 2 is a substrate of a display panel such as a plasma display panel or a liquid crystal panel. More specifically, the display panel is attached to the gap between the front panel and the back panel. In the case of a plasma display panel, the space inside is divided into discharge areas of respective display colors. In the case of a liquid crystal panel, the space inside is filled with liquid crystal. The pattern 3 is formed on the front panel or the back panel, and the inspection is performed on the pattern of the front panel or the back panel before the bonding. The control device 6 can photograph the inspection object 2 while the focus is on the pattern 3. The image pickup units 5a, 5b, and 5c are adjusted in a manner. This control device 6 executes the assembly adjustment flowchart shown in Fig. 3 at the time of assembly, which will be described in detail later. The imaging unit 5a is constituted by the imaging element 7a and the optical lens system unit 8a. The optical lens system unit 8a is disposed between the imaging element 7a and the inspection object 2, and is movable relative to the surface of the inspection object 2. It moves vertically in the approaching departure direction (hereinafter referred to as the Z-axis direction). The imaging unit 5b is constituted by the imaging element 7b and the optical lens system unit 8b. The optical lens system unit 8b is disposed between the imaging element 7b and the inspection object 2, and is vertically movable in the z-axis direction. The imaging unit 5 c is composed of an imaging element 7 c and an optical lens system unit 8 c 201140042, and the optical lens system unit 8 c is disposed between the imaging element 7 c and the inspection object 2 and is vertically movable in the Z-axis direction. In addition, for the sake of simplicity, only the minimum necessary components are described in FIG. Meanwhile, in order to obtain necessary reading characteristics, the optical lens system units 8a, 8b, and 8c also have a structure of a plurality of lens groups or a structure using an aspherical lens or the like. The drawing omits a drive system for moving the optical lens system unit 8a, 8b, 8c, or a control device for controlling the drive. As the imaging elements 7a' 7b, 7c, a solid-state imaging element of a semiconductor such as a CMOS element, a CCD element, or a MOS element is used. Among these elements, there are a linear type or a regional type, but in the present invention, a straight type or a regional type can be used. By the relative movement of the inspection object 2 and the gantry 4, each of the image pickup units 5a, 5b, and 5c attached to the gantry 4 scans the allocated area of the inspection object 2 to read the pattern 3. In the present embodiment, the inspection object 2 and the gantry 4 are relatively moved in the direction perpendicular to the paper surface of Fig. 1, and the X-axis direction of the inspection object 2 is scanned. 2(a), 2(b), and 2(c) are views showing a specific example of Fig. 1, respectively. Both sides of the gantry 4 are slidably supported in the Z-axis direction with respect to the surface of the inspection object 2 in a state of being positioned by the guides 9a, 9b. The main shaft 10 mounted on the fixed table 12 drives the screw shaft 1 1 screwed to the screw hole formed on the gantry 4 to rotate, and the drive gantry 4 is moved 4 times with respect to 201140042, and the Z-element light is set to 5 a. The surface of the inspection object 2 is slidably slid in the Z-axis direction. Here, the Z-axis drive unit 30 is constituted by the screw shaft 11 and the main motor 10 and the like. The image element unit 13a having the image pickup element 7a and the image pickup element unit 1 having the image pickup element 7b are fixed to the gantry in the Y-axis direction orthogonal to the X-axis direction at predetermined intervals in the Y-axis direction. 3b An imaging element unit 1 3 c having an imaging element 7 c. Further, on the gantry 4, optical lens system sheets 8a, 8b, and 8c are attached so as to be vertically slidable in the axial direction with respect to the surface of the inspection object 2. Further, the optical lens system units 8a, 8b, and 8c are mounted in a state where the optical axis is made coincident with the image pickup element unit 13a' of the image pickup unit 13b and the image pickup element unit 13c. The optical lens system unit 8a is positioned on one side by the guides 14a extending in the Z-axis direction, and is screwed to the screw holes formed on the other side so that the axis is supported parallel to the guides 14a The first screw shaft 15a drives the first screw shaft 1 to rotate by the first motor 16a attached to the gantry 4, and drives the optical lens system unit 8a to slide in the Z-axis direction. The sample "by the second motor 16b attached to the gantry 4 drives the second screw 15b to rotate" to drive the optical lens system unit to slide in the z-axis direction. The third screw 15c is rotated by the third motor 16c attached to the gantry 4 to drive the optical lens system unit 8c in the Z-axis direction. The optical lens system unit 8b is positioned by the guide 14b, and the optical system unit 8c is positioned by the guide i4c. Figure 3 shows a flow chart when the camera 1 is assembled. 201140042 First, in step S1, the imaging units 5a, 5b, and 5c are fixed to the gantry 4 in a state where the position in the vertical direction (Z-axis direction) is aligned with respect to the plane of the inspection object 2. At this time, as shown in Fig. 4, the imaging elements 7a, 7b, and 7c of the respective imaging units 5a, 5b, and 5c include mounting errors Az1 and Δζ2 of 1 μm in the Z-axis direction. In step S2, the main motor 10 is operated to focus the pattern 3 on the imaging unit 5a, and the gantry 4 is moved in the Z-axis direction for adjustment. Here, the state of the in-focus pattern 3 of the image pickup unit 5a is a state in which the focus image of the pattern 3 can be obtained in the image pickup element 7a. When the focus of the image pickup unit 5a is in focus, the magnification of the image pickup unit 5a is measured at step S3. Then, in step S4, it is determined whether or not the magnification measured at step S3 is a magnification suitable for the pattern. In the case where it is determined in step S4 that the magnification is not appropriate, the magnification of the imaging unit 5a is adjusted in step S5. The procedure of steps S2, S3, S4, and S5 is repeated to determine whether the magnification is suitable for the pattern. Then, if it is determined in step S4 that the magnification is appropriate, it is judged that the adjustment of the image pickup unit 5a is completed. When the adjustment of the image pickup unit 5a is completed, step S6 is performed next. In step S6, the focus of the image pickup unit 5b and the image pickup unit 5c is adjusted. Specifically, first, the second motor 16b is operated to obtain the focus image of the pattern 3 in the imaging element 7b of the imaging unit 5b, and the optical lens system unit 8b is moved in the Z-axis direction. Then, the third motor 16c is operated to move the optical lens system unit 8c in the Z-axis direction so that the focus image of the pattern 3 • 10 - 201140042 can be obtained by the image pickup device 7 c of the image pickup unit 5 c . By adjusting the image pickup units 5a, 5b, and 5c in this manner, the mounting errors Az1 and Az2 generated by the respective image pickup units 5a, 5b, and 5c in step S1 can be repaired. However, in the case where the adjustment is performed in this way, the magnification of the image of each of the image pickup units 5a, 5b, and 5c is subtly different. That is, in the present embodiment, the magnification adjustment of the image pickup unit and the focusing of the pattern are performed using the adjustment flow shown in Fig. 3 . Further, the camera of the present embodiment may move only the optical lens system units 8a, 8b, and 8c of the imaging units 5a, 5b, and 5c. In other words, the gantry 4 in which the plurality of imaging units 5a, 5b, and 5c are common is only one driving mechanism that is driven in the Z-axis direction. Therefore, the structure can be simplified as compared with the case where each of the image pickup units is provided with a drive mechanism that is driven in the Z-axis direction. Since the structure is simple, the driving precision of the driving mechanism is good, and the cost of the driving mechanism is also reduced. Fig. 5 (a) and Fig. 5 (b) are explanatory views showing the structure and performance of the image pickup unit of the embodiment. Since the structures of the image pickup units 5a, 5b, and 5c are the same, the image pickup unit 5b will be described here. Fig. 5(a) is a schematic structural view of the image pickup unit 5b. Fig. 5 (b) is a diagram showing the relationship between the amount of movement of the optical lens and the amount of movement of the focus when the distance between the imaging element 7b and the optical lens system unit 8b is changed. Further, the graph of Fig. 5(b) is a graph in which the optical lens system unit 8b is moved while the image pickup device 7b is fixed, and measurement is performed. -11- 201140042 In the present embodiment, 1/F=1/L1+1/L2 and M=L2/L1 of the lens formula satisfy the following conditions: F: focus distance of the optical lens system unit 8b = 15 mm L1·optical The distance between the lens system unit 8b and the object to be inspected 2 == 20 mm (when the amount of movement is )) L2: the distance between the optical lens system unit 8b and the image pickup element 7b = 6 〇 mm (when the amount of movement is 0) M: magnification = 3 ( When the amount of movement is 0) In the above relationship, when only the optical lens system unit 8b is moved, the amount of movement of the optical lens is substantially the same as the amount of movement of the focus. The change in the amount of movement of the optical lens and the magnification is shown in FIG. Further, Fig. 7 shows the amount of change in the stretching/contraction when the ΙΟΟμιη pattern is projected onto the image pickup element 7b in the projection pattern 300 μm. According to these figures, it can be seen that if the optical lens system unit 8b is moved above 〇·1 mm (Z-axis direction), it is known from FIG. 5(b) that the focus is from the surface of the object 2 in the Z-axis direction. The movement is only about 0.1 mm. Further, if the focus is moved by only about 0.1 mm in the Z-axis direction, it is understood from Fig. 7 that the projection pattern of ΙΟΟμη is contracted by only about 0.6 μm from 300 μm. Generally, when the camera 100 is assembled, an installation error of the mount 4 of about ±50 μm is generated. In the present embodiment, the optical lens system unit 8b can be moved to eliminate the error generated thereby. Further, even in the case where the optical lens system unit 8b is moved to the maximum ΙΟΟμηη for the purpose of elimination, the pattern of the stretching and contraction of the pattern 3 due to the change in magnification is -12-201140042 0.6 μηι with respect to the pattern of 3 ΟΟμη. Next, in the present embodiment, it is examined whether or not the pattern is not problematic. Hereinafter, the influence of 0.6 μm of the 300 μm pattern will be described. First, the pattern inspection device of the camera 100 described so far will be described. First, the pattern inspection device scans the pattern periodically arranged on the surface of the object to be inspected by the camera 100 to perform digitization. Then, the control device 6 compares the pattern data of the portion separated by a certain period with the manipulated pattern to detect the defect of the pattern. A method of pattern comparison inspection (hereinafter referred to as a comparison inspection method) of a portion different from the pattern data is also used by the technique described in Patent Document 1. Since the pattern inspection device uses a solid-state image sensor as the image pickup device, when a pitch portion of the pattern is projected on the image pickup device, it is necessary that a pitch portion of the pattern is surely included in an integer number of image pickup units. This is because if a pitch portion of the pattern is not included in an integer number of image pickup units, even when the data is compared, even a pattern of one cycle is judged to be different at the edge portion, and erroneous detection occurs. Therefore, the comparative inspection method is to compare and check the data obtained when the magnification of the optical lens system unit is optimized. Although the magnification of each of the image pickup units 5a, 5b, and 5c is slightly different for focusing, the camera 100 of the present embodiment satisfies the allowable 倍 of the magnification required for the comparative inspection by the comparative inspection method. Next, in Fig. 8, the pattern image of 300 μm on the image pickup element 7b of the present embodiment is changed to 0.6 μm in accordance with the magnification change caused by focusing. -13-201140042. As shown in Fig. 8, the imaging element 7b of the present embodiment has a cell size of ΙΟμπν. The pattern 3 of the inspection object 2 of ιοομπ! illustrated in Fig. 1 is projected onto the unit 30 having the unit size of ΙΟμηη by the optical lens system unit 8b of the optimum magnification as the projection image 17 of 300 μm. As shown in Fig. 8, since the cell size of the present embodiment is ΙΟμιη, the amount of deficiency of 0.6 μm is 6% with respect to the cell. In the case where the comparison check does not affect the detection result, the amount of projection of the projection image generated by focusing with respect to the unit can be tolerated by several %. Furthermore, the excess amount of the unit is converted into an allowable range of magnification. It is necessary to determine the amount of movement of the optical lens system unit 8b within the allowable range of this magnification. In the present embodiment, the allowable amount of magnification (permissible magnification Μ) of the optical lens system unit 8b of the image pickup unit 5b is controlled within the range of the following formula (1). C(N - ΔΝ)/Ρ < M <C(N + ΔΝ)/Ρ (1) Further, C: the element pitch of the image sensor 7b, P: the pitch of the pattern 3, and N: the image sensor 7b within the pitch of the projection image 17 The number of components (integer), ΔΝ: the allowable amount (element) of the projection image 1 7 FIG. 9 shows a series of flowcharts until the control device 6 derives the allowable amount of mounting errors of the imaging units 5a' 5b and 5c. Here, the element spacing C = 1 0, the pitch P = 1 0 0, and the number of components N = 30. The allowable amount ΔΝ becomes a unit of the projection pattern that is allowed to exceed a few unit parts. -14- 201140042 First, in step S11, the allowable excess of ΔΝ is determined based on the inspection accuracy required by the object 2 to be inspected. For example, let the allowable excess amount be 6%, that is, AN = 0.06 unit parts. Next, in step S12, the excess allowable amount ΔΝ is substituted into the above formula (1), and the allowable magnification Μ is derived. When applied to the example described with reference to Fig. 7, the allowable magnification Μ becomes a condition of the following formula (2). 2.994 < Μ < 3.006 (2) When the allowable magnification Μ is derived, the movement allowance amount of the optical lens system units 8b and 8c is determined in step S13. The relationship between the amount of movement of the optical lens system units 8b, 8c and the magnification depends on the optical design of the image pickup units 5a, 5b' 5c. The movement allowance based on this magnification becomes the mounting error tolerance amount of each of the image pickup units 5a, 5b, 5c in step S14. 1毫米。 In this embodiment, the optical lens system unit 8 b, 8 c can be moved to 0. 1 mm. Therefore, the focus position can be moved to 0.1 mm, and the mounting error is repaired by ±50 μm, and it can be confirmed that the focus of each of the image pickup units 5a, 5b, and 5c is not affected by the surface of the inspection object 2. Namely, it was confirmed that the pattern data obtained by the configuration of the present embodiment is suitable for the comparative inspection method. The configuration of the imaging unit 5b described above is a basic configuration. However, by optical lens design, a more appropriate structure can be designed. The following description will be made using the image pickup unit 5 for the conditions of the appropriate configuration. First, in the minimum condition 'fixed image -15-201140042 image element 7b of the appropriate configuration of the present embodiment, the optical lens system unit 8b is moved to focus the image pickup 5b. At this time, since the distance between the optical lens system unit 8b and the imaging element ί changes, the magnification of the imaging unit 5b changes. However, as before, the change in the magnification is small to the extent that the comparison test is small, and the focus can be adjusted within the magnification tolerance suitable for the comparative inspection method. As an example of an optical lens design that satisfies such conditions, there is a design in which the distance between the optical system unit 8b and the imaging element 7b is longer. The design is as follows: Even if the respective imaging units 5a, 5b, and 5c have the same magnification, the distance between the lens system unit 8b and the imaging element 7b, and the distance between the optical lens unit 8c and the imaging element 7c are longer. This is because the longer the distance between the optical lens unit 8b and the image pickup device 7b and the distance between the optical lens system unit 'image pickup device 7c, the smaller the amount of change in magnification when the distance between the optical lens system unit 8b and the element 7b is changed. In addition, since the amount of change when the distance between the optical lens system unit 8c and the imaging element 7c is changed is small, the movement allowable distance of the optical transmissive units 8b and 8c within the allowable change in the magnification becomes long. By designing under such conditions, even in the case where the mounting accuracy of the image pickup units 5a, 5b is not fine, the mounting error can be repaired. In the case where it is necessary to further reduce the range of the magnification change tolerance, that is, the case where the magnification error between the small image pickup units 5a, 5b, and 5c is required, the optical lens design can be handled. Further, when the pattern 3 is projected on the imaging π elements 7a, 7b, and 7c, the depth of focus of the imaging units 5a, 5b, and 5c is also important. That is, the unit cow 7b is described, so it is better to learn the best optical single-lens system 8c and the camera to make the magnification mirror 5c, and the other is more than 16-201140042. If the depth of focus is deep, there is no focus. The problem, but the depth of focus takes the number of apertures of the optical lens system units 8a, 8b, 8c, that is, NA. In order to refine the projected image when the pattern 3 is projected onto the image pickup elements 7a, 7b, and 7c, it is necessary to design the NA of the optical lens system units 8a, 8b, and 8c. To increase the NA of the optical lens system unit, it is preferable to design the camera unit to have a shallow depth. This is because if the depth of focus is deep, there is no problem of focusing. However, in order to increase the definition of the image, the depth of focus must be changed. In addition, when the depth of focus is deep, it is taken as a pattern projection until the structure behind the pattern. Image, so sometimes it is not possible to correctly capture this view. The depth of focus of the camera unit needs to be shallow. In this embodiment, it is preferable that the depth of focus of the imaging unit is 20 μm or less. Further, the present invention also has a feature of omitting a drive that normally drives each image pickup unit or a drive mechanism in the image pickup unit. Therefore, it is considered that it is not an inspection apparatus, and it is also applicable to the scanning of a high-speed reading of a precise image. Further, according to the pattern inspection apparatus, the characteristics of the drive mechanism for driving each of the pixels or the drive mechanism of the image pickup unit are omitted. The pattern inspection device can be manufactured at low cost. (Embodiment 2) Fig. 10 (a) is a schematic structural view showing the configuration and principle of an image capturing head of a pattern inspecting apparatus according to a second embodiment of the present invention. Fig. 1 〇 (b) is an enlarged view of a portion A of the figure. It is decided that the focus of raising the elevation is shallow. Creation. According to the present invention, the camera 200 of the second embodiment reads the pattern 3 formed on the surface of the inspection object 2 placed on the mobile station 1 even if the apparatus is a single image. The gantry 24 is supported to be slidable in the z-axis direction with respect to the surface of the object 2 to be inspected. The main shaft 1A mounted on the fixing table 12 is used to rotate the screw shaft 11 which is screwed with the screw hole formed in the table 24, and the driving table 24 is slid in the Z-axis direction with respect to the surface of the object 2 to be inspected. In the present embodiment, four imaging units 25a, 25b' 25c and 25d are fixed to the gantry 24 so that the imaging unit 2' can be imaged while the focus is on the pattern 3. Adjustments have been made to the assembly of the gantry 24. The imaging unit 25a is composed of an imaging element unit 26a and an optical lens system unit 28a. The imaging element unit 26a is provided with an imaging element 7a, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The optical lens system unit 28a is disposed between the imaging element unit 26a and the inspection object 2, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. Further, in the present embodiment, the image sensor unit 26a and the optical lens system unit 28a are connected so as to be one unit by using the drive unit 27a which can adjust the distance therebetween. The imaging element unit 26a and the optical lens system unit 28a are attached to the gantry 24 via the driving unit 27a. The imaging unit 25b is composed of an imaging element unit 26b and an optical lens system unit 28b. The imaging element unit 26b is provided with an imaging element 7b, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The optical lens system unit 28b is disposed between the imaging element unit 26b and the inspection object 2-18 - 201140042, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The imaging element unit 26b and the optical lens system unit 28b are connected so as to be one unit by the drive unit 27b that can adjust the distance between them. The imaging element unit 26b and the optical lens system unit 28b are attached to the gantry 24 via the driving unit 27b. The imaging unit 25c is composed of an imaging element unit 26c and an optical lens system unit 28c. The imaging element unit 26c is provided with an imaging element 7c, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The optical lens system unit 28c is disposed between the imaging element unit 26c and the inspection object 2, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The imaging element unit 26c and the optical lens system unit 28c are coupled by a driving unit 27c that adjusts the distance therebetween. The imaging element unit 26c and the optical lens system unit 28c are attached to the gantry 24 via the driving unit 27c. The imaging unit 25d is composed of an imaging element unit 26d and an optical lens system unit 28d. The imaging element unit 26d is provided with an imaging element 7d, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The optical lens system unit 28d is disposed between the imaging element unit 26d and the inspection object 2, and is vertically movable in the Z-axis direction with respect to the surface of the inspection object 2. The imaging element unit 26d and the optical lens system unit 28d are coupled by a driving unit 27d that can adjust the distance between them. The imaging element unit 26d and the optical lens system unit 28d are attached to the gantry 24 via the driving unit 27d. 201140042 According to the optical structure of the inspection object or the imaging units 25a to 25d, the inclination angle is required to be high with respect to the inspection target. In this case, as shown in FIG. 10(b), the imaging units 25a to 25d are mounted with the adjustment shaft mechanism 29 between the imaging element sheets sho 26d and the driving portions 27a to 27d, and the shaft mechanism 29 can be orthogonal to the three axes. The tilt adjustment of the three directions Ro, Pi, and Ya of the roll-pitch-yaw is used to form such a structure, and the optical lens system unit 28a and the image pickup element can be adjusted by controlling the control device 6 27a' Similarly to 7a, the distance between the lens system unit 28b and the image pickup element 7b is adjusted by controlling the drive unit 27b with the control device 6. Similarly, the control unit 6 controls the driving unit 27c to adjust the distance between the optical lens system unit and the imaging element 7c. Similarly, the optical lens system unit 28d can be adjusted in distance from the camera unit by the control unit 6 moving portion 27d. In this manner, by adjusting the distance between the optical lens system unit and the imaging element, the focal planes of the imaging units 25a to 25d can be adjusted to the same plane. The imaging units 25a to 25d can be simultaneously used by the single Z-axis driving unit 25, and the Z-axis driving unit. 30. The configuration of Fig. 11(a), Fig. 11(b), and Fig. 11(c) with the screw shaft 11 and the main motor 1A is shown in Fig. 10(a) in a state in which both sides are positioned by the guides 9a and 9b. It is supported along the surface of the object to be inspected 2 so as to be slidable in the direction of the surface of the object 2 to be inspected. On the gantry 24, image pickup units 25a to 25d are fixed to the Y-axis at predetermined intervals. The image pickup device unit 26a of the image pickup unit 25a is borrowed on one side, and in some cases, the optimum distance of the i-deflection 〇 drive portion I is adjusted. The rotator can be moved by controlling the distance of the piece of the drive 7d by the element 28c. to make. The γ-axis side is positioned in the Z-axis direction on the Z-axis side -20- 201140042. The guide 34 is extended upward and is screwed to the screw hole formed on the other side, so that the axis is supported and guided. Bearing 3 4 parallel spiral shafts 3 6 . The screw shaft 36 is driven to rotate by a motor 38 attached to the gantry 24, and drives the image pickup element unit 26a to slide in the Z-axis direction. The optical lens system unit 28a having the optical axis and the imaging element unit 26a is positioned on one side by the guide 35 extending in the z-axis direction, and is screwed to the screw hole formed on the other side, so that the shaft The heart is supported on a screw shaft 37 parallel to the guides 35. The screw shaft 37 is driven to rotate by a motor 39 mounted on the gantry 24, and drives the optical lens system unit 28a to slide in the Z-axis direction. The case of the imaging unit 2 5 b 2 2 5 d is also the same as that of the imaging unit 2 5 a. The image pickup element unit 26b of the image pickup unit 25b is driven to slide in the Z-axis direction by driving the rotary screw shaft 40 with the motor 42. The optical lens system unit 2 8 b of the image pickup unit 25b is driven to slide in the Z-axis direction by driving the rotary screw shaft 41 by the motor 43. The imaging element unit 26c of the imaging unit 25c is driven to slide in the Z-axis direction by the motor 46 driving the rotary screw shaft 44. The optical lens system unit 28c of the image pickup unit 25c is driven to rotate in the Z-axis direction by driving the rotary screw shaft 45 by the motor 47. The image pickup element unit 26d of the image pickup unit 25d is driven to slide in the Z-axis direction by driving the rotary screw shaft 48 by the motor 50. The optical lens system unit 28d of the image pickup unit 25d is driven to slide in the Z-axis direction by the motor 51 driving the rotary screw shaft 49. (Embodiment 3) - 21 - 201140042 Fig. 12 is a schematic plan view showing a pattern inspection apparatus according to a third embodiment of the present invention. In the third embodiment, the gantry 61 corresponding to the gantry* of the embodiment i or the gantry 24 of the second embodiment is moved in the Z-axis direction by operating the main motor 1〇 of the z-axis driving unit 3〇. On the gantry 61, a plurality of imaging units are mounted in two rows with the gantry 61 interposed therebetween. Eight imaging units 62a to 6 2h are attached to the gantry 61 of the present embodiment. The specific mounting method is the same as that of the first embodiment or the second embodiment, and therefore the description thereof is omitted. By mounting a plurality of imaging units on the gantry 61, the inspection area of the inspection object 2 can be divided into two areas. Therefore, the moving distance of the inspection object 2 can be reduced to half the distance of one line. As a result, compared with the configuration of the first embodiment or the second embodiment, the inspection speed is increased, and the inspection time can be shortened. Fig. 13 shows a modification of the third embodiment. In the modification of the third embodiment, a row of eight imaging units 62a, 62c, 62e, and 62g and an imaging unit 6 21), 620, and 62 are arranged in the same manner as the configuration shown in Fig. 12 with respect to the gantry 61. 2 lines of another line of 6211. In FIG. 13, when the inspection object 2 is moved in the X-axis direction with respect to the gantry 61 to perform reading, the imaging unit reads the region E1 of the inspection surface of the inspection object 2, and the imaging unit 62b reads and checks. In the region E2 of the inspection surface of the object 2, the imaging unit 62c reads the region E3 of the inspection surface of the inspection object 2, and the imaging unit 62d reads the region E4 of the inspection surface of the inspection object 2. In the same manner as in the case of -22-201140042, the imaging units 62e, 62f, 62g, and 62h read the areas E5, E6, E7, and E8 of the inspection surface of the inspection object 2, and the positions of the image pickup units 62a to 6h are shifted. Interlaced configuration. By forming such a configuration, the object 2 to be inspected can be efficiently inspected by one scan. As the main motor 1 〇, the first motor 16a, the second motor 16b, and the third motor 16c' motors 38, 39, 42, 43, 46, 47, 50, 5, 1 of the above embodiments, stepping can be used. Motor or servo motor. [Industrial Applicability] The present invention can be applied to pattern inspection of a display panel such as a plasma display panel or a liquid crystal panel. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic structural view of a camera of an inspection apparatus according to a first embodiment of the present invention. 2(a) is a schematic front view for showing a specific example of FIG. 1, FIG. 2(b) is a schematic side view for showing a specific example of FIG. 1, and FIG. 2(c) is for displaying a figure The specific example of 1 is abbreviated from the above figure. Fig. 3 is a flow chart showing the assembly adjustment of the camera of the first embodiment. Fig. 4 is a schematic structural view for explaining mounting errors of a plurality of cameras. Fig. 5 (a) is a schematic structural view of the image pickup unit of the first embodiment, and Fig. 5 (b) is a view showing the relationship between the amount of movement of the optical lens and the amount of focus shift in the first embodiment. -23- 201140042 Fig. 6 is a view showing the relationship between the amount of movement of the optical lens of the first embodiment and the magnification. Fig. 7 is a view showing the relationship between the amount of movement of the optical lens of the first embodiment and the amount of change in the projection pattern. Fig. 8 is a view showing the relationship between the throwing pattern and the unit of the image pickup element in the first embodiment. Fig. 9 is a flow chart for deriving the mounting error of the image pickup unit of the first embodiment. Fig. 10 (a) is a schematic structural view of a camera of an inspection apparatus according to a second embodiment of the present invention, and Fig. 10 (b) is an enlarged view of a main part of the camera of the second embodiment. Figure 11 (a) is a schematic front view showing a specific example of Figure 10, Figure 11 (b) is a schematic side view for showing a specific example of Figure 10 (a), Figure ii (c) is used The above diagram of the specific example of Fig. 10(a) is shown. Figure 12 is a schematic block diagram of a camera according to a third embodiment of the present invention. Fig. 13 is a schematic structural view showing a modification of the camera of the third embodiment of the present invention. Fig. 14 is a schematic view showing a conventional pattern inspection device. [Description of main component symbols] 1 Mobile station 2 Inspected object 3 Pattern 4 ' 24 ' 61 Rack-24 - 201140042 5a , 5b ' 5c , 25a to 25d 6 2 a ~ 6 2 h 6 7 a~ 7c 8 a~ 8c 28a- '28d 9 a ' 9b, 14a, 14b ' 14c , 34 ' 3 5 10 11' 36, 37 ' 40, 4 44, 45, 48, 49 12 13a , 13b , 13 c , 26a ~ 2 6 d 15a ~ 1 5 c 16a ~ 1 6 c 27a ~ 27d 29 30 38 ' 39 ' 42, 43, 46, 47, 50, 5 1 E 1 ~ E8 100 200 Camera unit control unit · Imaging element optical lens system unit guide Main motor screw shaft fixed table image sensor unit first to third screw shafts 1st to 3rd motor drive unit adjustment shaft mechanism Z-axis drive unit Motor inspection object 2 inspection surface area camera head-25-