TWI607253B - Auto-focus system, method and optical imaging inspection apparatus - Google Patents
Auto-focus system, method and optical imaging inspection apparatus Download PDFInfo
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Description
本發明涉及自動對焦技術，尤指能夠達到快速對焦之自動對焦系統、方法及運用此二者的影像檢測儀器。 The invention relates to an autofocus technology, in particular to an autofocus system, a method and a video detecting instrument capable of achieving fast focusing.
傳統精密檢測通常包含有一光學儀器(例如：線掃描攝影機、面掃描攝影機等)用以對物件的表面取像，再以電腦影像處理技術來檢出異物或圖案異常等瑕疵。然而，在有些情況下，物件並不是乖乖靜止地被檢測儀器取像，而是會產生浮動的情形，一旦位置改變就會產生失焦的情形。 Conventional precision inspection usually includes an optical instrument (for example, a line scan camera, a surface scan camera, etc.) for taking images of the surface of an object, and then using computer image processing technology to detect foreign matter or pattern anomalies. However, in some cases, the object is not imaged statically by the detecting instrument, but is a floating condition, and once the position is changed, a defocus condition occurs.
舉例而言，在對應精密物件(例如面板)進行檢測時，為避免物件於輸送程序中因輸送帶刮傷或污損產生瑕疵，針對部分精密物件會設置氣浮載台，使物件浮空並避免與下方平面直接接觸。於輸送的過程中欲對物件進行檢測，物件因為氣浮的作用，會懸浮在載台上方，懸浮的高度係在相當的範圍值內浮動(例如300um)，由於一般攝影機的景深只有35um，並不能將待測物精準的控制在景深範圍內。是以，搭配所述的氣浮載台勢必要提供一種既快速又有效的對焦方式。 For example, when detecting a precision object (such as a panel), in order to prevent the object from being scratched or scratched by the conveyor belt during the conveying process, an air floating stage is provided for some precision objects to make the object float and Avoid direct contact with the underlying plane. In the process of conveying, the object is to be inspected. The object will float above the stage because of the air floatation. The height of the suspension floats within a considerable range (for example, 300um), because the depth of field of the general camera is only 35um, and The object to be tested cannot be accurately controlled within the depth of field. Therefore, it is necessary to provide a fast and effective focusing mode with the air floating carrier.
本發明揭露一種有別於傳統的自動對焦系統、方法及影像檢測儀器，該自動對焦系統能使一線形光斑的一部分經一物鏡投射到一物件上，並對物件及線形光斑的該部分進行影像擷取以得到一目標影像，及 利用影像處理技術取得目標影像中的該線形光斑的該部分的長、寬與位置，藉以判定物件的對焦狀態，使得物鏡可依據前述判定結果迅速調整到讓物件對焦之位置。 The invention discloses a different autofocus system, method and image detecting instrument. The autofocus system can project a part of a linear spot onto an object through an objective lens, and image the object and the portion of the linear spot. Capture to obtain a target image, and The image processing technology is used to obtain the length, width and position of the portion of the linear spot in the target image, thereby determining the focus state of the object, so that the objective lens can be quickly adjusted to the position where the object is in focus according to the foregoing determination result.
具體而言，本發明之自動對焦系統包括一線形光源、上述的該物鏡、一遮光部件、一影像感測裝置及一對焦調整模組該線形光源係用以產生線形光斑，例如線形的雷射光斑。物鏡用以接收線形光斑的一部分，並將線形光斑的該部分投射至物件。遮光部件設於線形光源與該物鏡之間的光學路徑上，用以部分地遮擋線形光斑，使線形光斑只有該部分進入物鏡。影像感測裝置用以擷取物件與線形光斑的該部分，藉以得到目標影像。對焦調整模組係用以根據目標影像中該線形光斑的該部分的長度、寬度及位置，判定該物件之對焦狀態，藉以調整物鏡與物件之間的距離。 Specifically, the autofocus system of the present invention includes a linear light source, the objective lens, a light shielding component, an image sensing device, and a focus adjustment module. The linear light source is used to generate a linear spot, such as a linear laser. Spot. The objective lens is for receiving a portion of the linear spot and projecting the portion of the linear spot to the object. The light shielding member is disposed on the optical path between the linear light source and the objective lens to partially block the linear spot so that only the portion of the linear spot enters the objective lens. The image sensing device is configured to capture the portion of the object and the linear spot to obtain the target image. The focus adjustment module is configured to determine the focus state of the object according to the length, width and position of the portion of the linear spot in the target image, thereby adjusting the distance between the objective lens and the object.
較佳地，本發明之自動對焦系統可包括一會聚透鏡、一反射鏡、一第一分光鏡、一第二分光鏡及位於該影像感測裝置之前方的一成像透鏡。會聚透鏡的入射面用以接收線形光源所發出的線形光斑。遮光部件設於會聚透鏡的出光面與反射鏡之間。反射鏡用以將線形光斑的該部分反射至第一分光鏡。第一分光鏡用以續將線形光斑反射至物鏡，並允許從物件反射回物鏡的反射光與線形光斑的該部分穿透之。第二分光鏡位於第一分光鏡與成像透鏡之間，用以接收來自第一分光鏡的該反射光與線形光斑的該部分並將之反射至成像透鏡。成像透鏡用以將該反射光與線形光斑的該部分會聚成像於影像感測裝置之一感測面，以產生上述的目標影像。 Preferably, the autofocus system of the present invention may include a converging lens, a mirror, a first beam splitter, a second beam splitter and an imaging lens located in front of the image sensing device. The incident surface of the converging lens is for receiving a linear spot emitted by the linear light source. The light shielding member is disposed between the light emitting surface of the condenser lens and the mirror. A mirror is used to reflect the portion of the linear spot to the first beam splitter. The first beam splitter is configured to continuously reflect the linear spot to the objective lens and allow the reflected light reflected from the object back to the objective lens to penetrate the portion of the linear spot. The second beam splitter is located between the first beam splitter and the imaging lens for receiving the reflected light from the first beam splitter and the portion of the linear spot and reflecting it to the imaging lens. The imaging lens is configured to focus the reflected light and the portion of the linear spot on one of the sensing surfaces of the image sensing device to generate the target image.
較佳地，本發明之自動對焦系統可更包括一驅動裝置，驅動裝置耦接對焦調整模組，用以根據對焦調整模組之判定結果對應驅動物鏡移動，以調整物鏡與物件之間的距離。 Preferably, the autofocus system of the present invention further includes a driving device coupled to the focus adjustment module for adjusting the distance between the objective lens and the object according to the determination result of the focus adjustment module. .
本發明之影像檢測儀器除了包括上述之自動對焦系統之外，更包括一影像擷取裝置及一照明單元。照明單元用以提供物件之照明，影像擷取裝置用以在自動對焦系統之對焦調整模組判定物件為已對焦時，隨即擷取物件的影像。 In addition to the above-described autofocus system, the image detecting apparatus of the present invention further includes an image capturing device and a lighting unit. The illumination unit is configured to provide illumination of the object, and the image capture device is configured to capture an image of the object when the focus adjustment module of the autofocus system determines that the object is in focus.
較佳地，本發明之影像檢測儀器的照明單元可包括一分光鏡及一照明裝置，前述分光鏡與該自動對焦系統之第一、二分光鏡同軸，用以接收來自照明裝置的可見光，並將之反射至物件，以提供照明。 Preferably, the illumination unit of the image detecting apparatus of the present invention may include a beam splitter and an illumination device, the beam splitter being coaxial with the first and second beam splitters of the autofocus system for receiving visible light from the illumination device, and Reflect it to the object to provide illumination.
較佳地，本發明之影像檢測儀器可更包括一濾鏡，其設於影像擷取裝置與照明單元之分光鏡之間，藉以防止從物件反射回來的該線形光斑的該部分進入影像擷取裝置。 Preferably, the image detecting apparatus of the present invention further includes a filter disposed between the image capturing device and the beam splitter of the illumination unit to prevent the portion of the linear spot reflected from the object from entering the image capturing device. Device.
本發明之雷射自動對焦方法，包括下列步驟：(a).產生一道線形光斑；(b).使線形光斑只有一部分經由一物鏡投射至一物件；(c).對物件與線形光斑的該部分進行影像擷取，以擷取得到一目標影像；及(d).根據目標影像中的線形光斑的該部分的長度、寬度及位置，判定物件之對焦狀態；以及(e).根據d步驟的判定結果，對應調整物鏡與物件之間的距離。 The laser autofocus method of the present invention comprises the steps of: (a) generating a linear spot; (b) projecting a portion of the linear spot through an objective lens to an object; (c) the object and the linear spot. Partially performing image capture to obtain a target image; and (d) determining the focus state of the object based on the length, width, and position of the portion of the linear spot in the target image; and (e). The result of the determination corresponds to adjusting the distance between the objective lens and the object.
相對於先前技術，本發明之雷射自動對焦系統及方法首創根據所擷取的上述目標影像中的線形光斑的該部分的長度與寬度，來判定物件距離焦點的遠近，並根據線形光斑的該部分的長度及寬度是否已分別變小至一臨界值，來判定物件是否已經位在焦點上，及根據線形光斑的該部分的位置來判定物件目前是位在焦點上方或下方，其所涉及者僅是簡單幾何形狀的光斑影像處理，這使得負責影像處理的演算法所需處理的畫面畫素的數量不需太多，且在統計光斑的質心位置上也可較為精確，能有效降低因過去光斑亮度不均勻所導致質心忽左忽右的情形發生。 Compared with the prior art, the laser autofocus system and method of the present invention firstly determines the distance of the object from the focus according to the length and width of the portion of the linear spot in the target image captured, and according to the linear spot Whether the length and width of the portion have been reduced to a critical value, respectively, to determine whether the object is already in focus, and determining whether the object is currently above or below the focus according to the position of the portion of the linear spot, the person involved It is only the spot image processing of simple geometry, which makes the number of picture pixels required for the algorithm responsible for image processing not too much, and can be more accurate at the centroid position of the statistical spot, which can effectively reduce the cause. In the past, the uneven brightness of the spot caused the situation that the center of mass suddenly left and right.
100‧‧‧影像檢測儀器 100‧‧‧Image inspection equipment
1‧‧‧自動對焦系統 1‧‧‧Autofocus system
10‧‧‧物鏡 10‧‧‧ Objective
2‧‧‧取像單元 2‧‧‧Image capture unit
20‧‧‧影像檢測單元 20‧‧‧Image detection unit
21‧‧‧影像擷取裝置 21‧‧‧Image capture device
22‧‧‧成像透鏡 22‧‧‧ imaging lens
23‧‧‧濾鏡 23‧‧‧ filter
3‧‧‧照明單元 3‧‧‧Lighting unit
31‧‧‧分光鏡 31‧‧‧beam splitter
32‧‧‧照明裝置 32‧‧‧Lighting device
33‧‧‧準直透鏡 33‧‧‧ Collimating lens
4‧‧‧物件 4‧‧‧ objects
5‧‧‧線形光源 5‧‧‧Linear light source
6‧‧‧光學組件 6‧‧‧Optical components
61‧‧‧會聚透鏡 61‧‧‧Converging lens
62‧‧‧遮光部件 62‧‧‧Shading parts
63‧‧‧反射鏡 63‧‧‧Mirror
64‧‧‧第一分光鏡 64‧‧‧First Beamsplitter
66‧‧‧第二分光鏡 66‧‧‧Second beam splitter
67‧‧‧成像透鏡 67‧‧‧ imaging lens
7‧‧‧影像感測裝置 7‧‧‧Image sensing device
70‧‧‧感測面 70‧‧‧Sense surface
701‧‧‧第一感測區 701‧‧‧First sensing area
702‧‧‧第二感測區 702‧‧‧Second Sensing Area
8‧‧‧對焦調整模組 8‧‧‧Focus adjustment module
9‧‧‧驅動裝置 9‧‧‧ drive
L1~L5‧‧‧條狀光斑 L1~L5‧‧‧ strip spot
第一圖係顯示本發明之影像檢測儀器的系統示意圖。 The first figure shows a system diagram of the image detecting apparatus of the present invention.
第二至六圖係顯示本發明之自動對焦系統在不同的對焦狀態下所取得目標影像的示意圖。 The second to sixth figures show schematic diagrams of the target images obtained by the autofocus system of the present invention in different in-focus states.
第一圖顯示本發明之影像檢測儀器100的一個較佳實施 例，用以對一物件4的表面取像及根據取像結果進行瑕疵檢測，以找出存在於物件4上的瑕疵。影像檢測儀器100包括一自動對焦系統1、一取像單元2、一照明單元3及一影像檢測單元20。其中，自動對焦系統1用以對物件4進行對焦。取像單元2用以在自動對焦系統1對物件4完成自動對焦後對物件4取像，藉以拍攝得到清晰的一待測影像。照明單元3用以提供取像單元2對物件4取像時所需之照明。影像檢測單元20耦接取像單元2，用以接收該待測影像，並以電腦影像處理技術從該待測影像檢出異物或圖案異常等瑕疵。 The first figure shows a preferred implementation of the image sensing apparatus 100 of the present invention. For example, the image of the surface of an object 4 is taken and detected according to the image capturing result to find the flaw existing on the object 4. The image detecting apparatus 100 includes an autofocus system 1, an image capturing unit 2, an illumination unit 3, and an image detecting unit 20. The autofocus system 1 is used to focus on the object 4. The image capturing unit 2 is configured to take an image of the object 4 after the autofocus system 1 performs autofocusing on the object 4, thereby obtaining a clear image to be tested. The illumination unit 3 is used to provide illumination required for the image capturing unit 2 to take an image of the object 4. The image detecting unit 20 is coupled to the image capturing unit 2 for receiving the image to be tested, and detecting a foreign matter or a pattern abnormality from the image to be tested by using a computer image processing technology.
自動對焦系統1包括一線形光源5、一光學組件6、一影像感測裝置7、一對焦調整模組8及一驅動裝置9以及一物鏡10。線形光源5用以產生一道線形光斑，例如線形的紅外線雷射光斑。光學組件6依序包括一會聚透鏡61、一遮光部件62、一反射鏡63、一第一分光鏡64、一第二分光鏡66及一成像透鏡67。 The autofocus system 1 includes a linear light source 5, an optical component 6, an image sensing device 7, a focus adjustment module 8 and a driving device 9, and an objective lens 10. The linear light source 5 is used to generate a linear spot, such as a linear infrared laser spot. The optical component 6 includes a converging lens 61, a light shielding member 62, a mirror 63, a first beam splitter 64, a second beam splitter 66, and an imaging lens 67.
會聚透鏡61的入射面接收線形光源5所發出的該線形光斑。遮光部件62設於線形光源5及物鏡10的光學路徑上，也就是該線形光斑的行進路線上，更具體地說，是設於會聚透鏡61的出光面與反射鏡63之間，用以部分地遮擋該線形光斑而使該線形光斑只有一部分進入該物鏡10，例如擋住一半或將近一半的該線形光斑，只允許該線形光斑的一半或將近一半進入物鏡10的其中一半邊。反射鏡63用以將該線形光斑的該部分反射至第一分光鏡64。第一分光鏡64續將該線形光斑的該部分反射至物鏡10。在此實施例中，由於一半或將近一半的線形光斑已被遮光部件62擋掉，因此物鏡10實際上僅用其半邊來接收未被擋掉的該線形光斑的該部分，並將該線形光斑的該部分投射至物件4。由於照明單元3所產生的光也會經由物鏡10投射到物件4，因此，從物件4反射回來的反射光與從物件4反射回來的該線形光斑的該部分，都會反射進入物鏡10，進而穿透第一分光鏡64。第二分光鏡66係位於第一分光鏡64與成像透鏡67之間，用以接收來自第一分光鏡64的該反射光與該線形光斑的該部分並將之反射至成像透鏡67。成像透鏡67位於影像感測裝置7之前方，用以將該反射光與該線形光斑的該部分會聚成像於影像感測裝置7之一感測面，使得影像感測裝置7對應輸出內容包含物件4與該線形光斑的該部分之一目標影像，簡言之， 影像感測裝置7係用以對物件4與該線形光斑的該部分進行影像擷取，藉以得到該目標影像。 The incident surface of the condenser lens 61 receives the linear spot emitted by the linear light source 5. The light shielding member 62 is disposed on the optical path of the linear light source 5 and the objective lens 10, that is, on the traveling path of the linear spot, more specifically, between the light emitting surface of the condenser lens 61 and the mirror 63, for partially The linear spot is shielded such that only a portion of the linear spot enters the objective lens 10, for example, blocking half or nearly half of the linear spot, allowing only half or nearly half of the linear spot to enter one half of the objective lens 10. A mirror 63 is used to reflect the portion of the linear spot to the first beam splitter 64. The first beam splitter 64 continues to reflect the portion of the linear spot to the objective lens 10. In this embodiment, since half or nearly half of the linear spot has been blocked by the light blocking member 62, the objective lens 10 actually receives only the portion of the linear spot that is not blocked by its half, and the linear spot is This portion is projected onto the object 4. Since the light generated by the illumination unit 3 is also projected to the object 4 via the objective lens 10, the reflected light reflected from the object 4 and the portion of the linear spot reflected from the object 4 are reflected into the objective lens 10 and then worn. The first beam splitter 64 is passed through. The second dichroic mirror 66 is located between the first dichroic mirror 64 and the imaging lens 67 for receiving the reflected light from the first dichroic mirror 64 and the portion of the linear spot and reflecting it to the imaging lens 67. The imaging lens 67 is located in front of the image sensing device 7 for focusing the reflected light and the portion of the linear spot on the sensing surface of the image sensing device 7, so that the image sensing device 7 corresponding to the output content includes the object 4 with one of the target images of the portion of the linear spot, in short, The image sensing device 7 is configured to image the object 4 and the portion of the linear spot to obtain the target image.
對焦調整模組8係耦接該影像感測裝置7，並接收該目標影像及對它進行影像處理與分析，藉以得到該目標影像中的該線形光斑的該部分的長度、寬度及位置等參數，再根據所得到的前述參數來判定物件4目前的對焦狀況(例如判定物件4是位在物鏡10的焦點處，還是位在焦點的上方或下方)，如此，物鏡10的位置就可以根據對焦調整模組8的前述判定結果來調整。簡言之，對焦調整模組8係用以根據該目標影像中該線形光斑的該部分的長度、寬度及位置，判定物件4之對焦狀態，藉以調整物鏡10與物件4之間的距離。 The focus adjustment module 8 is coupled to the image sensing device 7 and receives the target image and performs image processing and analysis thereon to obtain parameters such as the length, width and position of the portion of the linear spot in the target image. And determining the current focus condition of the object 4 according to the obtained parameters (for example, determining whether the object 4 is at the focus of the objective lens 10 or at or above the focus), so that the position of the objective lens 10 can be based on the focus. The aforementioned determination result of the adjustment module 8 is adjusted. In short, the focus adjustment module 8 is configured to determine the focus state of the object 4 according to the length, width and position of the portion of the linear spot in the target image, thereby adjusting the distance between the objective lens 10 and the object 4.
更詳而言之，基於成像原理，當物件4離物鏡10之焦點愈遠，在該目標影像中的該線形光斑的該部分就會愈長且愈粗；反之，當物件4愈接近焦點，在該目標影像中的該線形光斑的該部分就會愈短且愈細；其中，如果物件4是位在焦點的上方，則該線形光斑的該部分的位置就會位在一參考點的一側(例如左側)，而如果物件4是位在焦點的下方，則該線形光斑的該部分的位置就位在該參考點的另一側(例如右側)；而當該目標影像中的該線形光斑的該部分長度與寬度逐漸變小至一臨界值時，表示物件4已經來到焦點處，此時該目標影像中的該線形光斑的該部分看起來就是一個接近點狀的光斑。 More specifically, based on the imaging principle, the farther the object 4 is from the focus of the objective lens 10, the longer and thicker the portion of the linear spot in the target image; conversely, the closer the object 4 is to the focus, The portion of the linear spot in the target image will be shorter and finer; wherein if the object 4 is above the focus, the position of the portion of the linear spot will be at a reference point Side (eg, left side), and if object 4 is below the focus, the portion of the linear spot is positioned on the other side of the reference point (eg, the right side); and when the object is in the target image When the length and width of the portion of the spot gradually decrease to a critical value, it indicates that the object 4 has come to the focus, and the portion of the linear spot in the target image appears to be a point-like spot.
第二至六圖顯示本發明之自動對焦系統在自動對焦之運作過程中由該影像感測裝置7所擷取的目標影像70，每一圖中的目標影像70都標示了一道虛擬中間線，並以此虛擬中間線作為參考點而分成一左側區701與一右側區702。對焦調整模組8對第二圖所示的目標影像70進行影像處理與分析之後(此可利用現有的影像處理分析技術)，就能得到目標影像70中的該線形光斑的該部分L1的長度、寬度及位置等參數，並因此得知該線形光斑的該部分L1係為一較粗較長且位於該參考點一側(也就是位於該左側區701)，故對焦調整模組8此時判定物件4目前是位在焦點的上方，這表示物鏡10需要往上移動，以使該物件4能往焦點趨近。隨後，影像感測裝置7會再擷取一次目標影像70，如果所擷取到的目標影像70係如第三圖所示，則對焦調整模組8對第三圖所示的目標影像70進行影像處理與分 析之後，就能根據該線形光斑的該部分L2的前述參數而得知其係為一較短較細且同樣位於該左側區701，故對焦調整模組8此時判定物件4目前仍是位在焦點的上方，但比先前更靠近焦點(因為該線形光斑的該部分L2變得更短更細了)，這表示物鏡10還需要再往上移動，以使物件4能更往焦點趨近。 2 to 6 are diagrams showing the target image 70 captured by the image sensing device 7 during the operation of the autofocus system of the present invention, and the target image 70 in each of the images is marked with a virtual intermediate line. And using the virtual intermediate line as a reference point, it is divided into a left side area 701 and a right side area 702. After the focus adjustment module 8 performs image processing and analysis on the target image 70 shown in the second figure (this can use the existing image processing analysis technology), the length of the portion L1 of the linear spot in the target image 70 can be obtained. Parameters such as the width and the position, and thus the portion L1 of the linear spot is a thicker and longer side of the reference point (that is, located in the left side 701), so the focus adjustment module 8 is It is determined that the object 4 is currently positioned above the focus, which means that the objective lens 10 needs to be moved upwards so that the object 4 can approach the focus. Then, the image sensing device 7 captures the target image 70 again. If the captured target image 70 is as shown in the third figure, the focus adjustment module 8 performs the target image 70 shown in the third figure. Image processing and points After the analysis, it can be known that the line is adjusted to be shorter and thinner and is also located in the left side area 701 according to the aforementioned parameters of the portion L2 of the linear spot. Therefore, the focus adjustment module 8 determines that the object 4 is still in position at this time. Above the focus, but closer to the focus than before (because the portion L2 of the linear spot becomes shorter and thinner), this means that the objective lens 10 needs to be moved up again so that the object 4 can be closer to the focus. .
如果影像感測裝置7所擷取到目標影像70是如第六圖所示，則對焦調整模組8對第六圖所示的目標影像70進行影像處理與分析之後，就能根據該線形光斑的該部分L5的的長度、寬度及位置等參數而得知，其為係為一較粗較長且位於該參考點另一側(也就是位於該右側區702)，故對焦調整模組8此時判定物件4目前是位在焦點的下方，這表示物鏡10需要往下移動，以使物件4能往焦點趨近。同理，如果影像感測裝置7所擷取到目標影像70是如第五圖所示，則對焦調整模組8此時將判定該物件4目前是位在焦點的下方，但比先前更靠近焦點(因為該線形光斑的該部分L4變得更短更細了)，這表示物鏡10需要再往下移動，以使物件4能再往焦點趨近。 If the target image 70 captured by the image sensing device 7 is as shown in FIG. 6, the focus adjustment module 8 performs image processing and analysis on the target image 70 shown in FIG. 6, and then according to the linear spot. It is known that the length, the width and the position of the portion L5 are such that they are thicker and longer and are located on the other side of the reference point (that is, in the right side region 702), so the focus adjustment module 8 At this time, it is determined that the object 4 is currently positioned below the focus, which means that the objective lens 10 needs to be moved downward so that the object 4 can approach the focus. Similarly, if the target image 70 captured by the image sensing device 7 is as shown in FIG. 5, the focus adjustment module 8 will now determine that the object 4 is currently below the focus, but is closer than before. The focus (because the portion L4 of the linear spot becomes shorter and thinner), this means that the objective lens 10 needs to be moved down again so that the object 4 can approach the focus again.
如果影像感測裝置7所擷取到目標影像70是如第四圖所示，則當對焦調整模組8對第四圖所示的目標影像70進行影像處理與分析之後，就能根據該線形光斑的該部分L3的長度、寬度等參數而得知該部分L3的長度與寬度分別已變小至一臨界值，故對焦調整模組8此時判定物件4目前是位在焦點上，這表示本發明之自動對焦系統1已完成物件4的對焦，此時自動對焦系統1就會立即傳送信號通知取像單元2，以使取像單元2對物件4取像，藉以拍攝得到清晰的該待測影像。 If the image sensing device 7 captures the target image 70 as shown in the fourth figure, after the focus adjustment module 8 performs image processing and analysis on the target image 70 shown in the fourth figure, the line shape can be determined according to the line shape. The length and width of the portion L3 of the portion of the spot L3 are reduced to a critical value, so the focus adjustment module 8 determines that the object 4 is currently in focus, which means The autofocus system 1 of the present invention has completed the focusing of the object 4, and the autofocus system 1 immediately transmits a signal to the image capturing unit 2 to cause the image capturing unit 2 to take an image of the object 4, thereby obtaining a clear image. Measure the image.
復參閱第一圖，驅動裝置9係耦接對焦調整模組8，用以根據對焦調整模組8之判定結果對應驅動物鏡10往上或往下移動，藉以調整物鏡10與物件4之間的距離，直到自動對焦系統1已完成物件4的對焦為止。 Referring to the first figure, the driving device 9 is coupled to the focus adjusting module 8 for moving the objective lens 10 upward or downward according to the determination result of the focus adjusting module 8 to adjust the relationship between the objective lens 10 and the object 4. Distance until the autofocus system 1 has finished focusing the object 4.
照明單元3包括一分光鏡31、一照明裝置32，以及設於分光鏡31與照明裝置32之間的一準直透鏡33。照明單元3之分光鏡31與自動對焦系統1之第一分光鏡64及第二分光鏡66同軸，用以接收來自該照明裝置32的可見光，並將之反射至物件4，以提供照明。 The illumination unit 3 includes a beam splitter 31, an illumination device 32, and a collimator lens 33 disposed between the beam splitter 31 and the illumination device 32. The beam splitter 31 of the illumination unit 3 is coaxial with the first beam splitter 64 and the second beam splitter 66 of the autofocus system 1 for receiving visible light from the illumination device 32 and reflecting it to the object 4 to provide illumination.
取像單元2包括一影像擷取裝置21、一成像透鏡22及一濾 鏡23。影像擷取裝置21用以在自動對焦系統1之對焦調整模組8判定物件4已對焦時，隨即對物件4取像，擷取得到內容包含物件4且清晰的該待測影像。濾鏡23設於影像擷取裝置21與照明單元3之分光鏡31之間，用以過濾特定的波段的光(在此實施例中是指上述的紅外線雷射光斑)，藉以防止該線形光斑的該部分進入影像擷取裝置21。 The image capturing unit 2 includes an image capturing device 21, an imaging lens 22, and a filter Mirror 23. The image capturing device 21 is configured to take an image of the object 4 when the focus adjustment module 8 of the autofocus system 1 determines that the object 4 is in focus, and obtain the image to be tested that contains the object 4 and is clear. The filter 23 is disposed between the image capturing device 21 and the beam splitter 31 of the illumination unit 3 for filtering light of a specific wavelength band (in this embodiment, the above-mentioned infrared laser spot), thereby preventing the linear spot. This portion enters the image capture device 21.
藉由上述設置，本發明之雷射對焦方法包括下列步驟： With the above arrangement, the laser focusing method of the present invention comprises the following steps:
(a).產生一道線形光斑，例如線形的紅外線雷射光斑；此步驟可利用上述的線形光源5予以達成。 (a). Producing a linear spot, such as a linear infrared laser spot; this step can be achieved using the linear light source 5 described above.
(b).使該線形光斑只有一部分經由一物鏡10投射至一物件4，其中物鏡10僅用其半邊接收該線形光斑的該部分至少部分的該雷射光；此步驟可利用上述的遮光部件62予以達成。 (b) projecting only a portion of the linear spot to an object 4 via an objective lens 10, wherein the objective lens 10 receives at least a portion of the laser light from the portion of the linear spot with only its half; this step may utilize the light blocking member 62 described above. To be reached.
(c).對物件4與該線形光斑的該部分進行影像擷取，以擷取得到一目標影像；此步驟可利用上述的影像感測裝置7予以達成。 (c) image capturing the object 4 and the portion of the linear spot to obtain a target image; this step can be achieved by the image sensing device 7 described above.
(d).根據該目標影像中的線形光斑的該部分的長度、寬度及位置，判定該物件之對焦狀態；此步驟可利用上述的對焦調整模組8予以達成。 (d) determining the in-focus state of the object based on the length, width, and position of the portion of the linear spot in the target image; this step can be achieved by using the focus adjustment module 8 described above.
(e).根據對焦狀態的判定結果步驟d之判定結果，對應調整該物鏡10與該物件4之間的距離；此步驟可利用上述的驅動裝置9予以達成。 (e). Adjusting the distance between the objective lens 10 and the object 4 according to the determination result of the determination result of the in-focus state, step d; this step can be achieved by the above-described driving device 9.
另需指出的是，本發明之自動對焦系統及方法除了應用於上述的影像檢測儀器之外，尚可應用於其它需拍攝影像的裝置，例如具有照相功能的手機。 It should be noted that the autofocus system and method of the present invention can be applied to other devices that need to take images, such as a camera with a camera function, in addition to the above-mentioned image detecting instruments.
綜上所述，本發明之自動對焦系統及方法對於對焦與否的判斷上能較為直接。其中，影像感測裝置7所擷取的上述目標影像可利用二值化的影像處理(Image binarization)得出其中的該線形光斑的該部分的長度及寬度，據以判定物件4距離焦點的遠近，並根據該線形光斑的該部分的長度及寬度是否已分別變小至一臨界值，據以判定物件4是否已經位在焦點上。再者，本發明之自動對焦系統及方法可根據上述目標影像中的該線形光斑的該部分的位置，也就是在上述參考點的左邊或右邊(或說是偏左或偏右)來決定物件4目前是位在焦點上方或下方，而不必連續取得 所有遠近位置的長度變化梯度來推估出真正的焦平面方位。此外，相較於傳統雷射對焦系統需要處理各種光點的形狀變化，本發明係利用線形光斑來判定對焦狀態，僅涉及單純的幾何長方形狀，這使得負責影像處理與分析的演算法所需處理的畫面畫素的數量不需太多，且在統計光斑的質心位置上也可較為精確，能有效降低因過去光斑亮度不均勻所導致質心忽左忽右的情形發生。 In summary, the autofocus system and method of the present invention can be relatively straightforward in determining the focus or not. The target image captured by the image sensing device 7 can obtain the length and width of the portion of the linear spot by using binarized image binarization, thereby determining the distance of the object 4 from the focus. And determining whether the object 4 is already in focus depending on whether the length and width of the portion of the linear spot have been reduced to a critical value, respectively. Furthermore, the autofocus system and method of the present invention can determine an object based on the position of the portion of the linear spot in the target image, that is, to the left or right of the reference point (or left or right). 4 is currently above or below the focus, and does not have to be obtained continuously The length gradient of all near and far positions is used to estimate the true focal plane orientation. In addition, compared with the conventional laser focusing system, it is required to process the shape change of various light spots. The present invention utilizes a linear spot to determine the in-focus state, and only involves a simple geometric rectangle, which requires an algorithm responsible for image processing and analysis. The number of processed picture pixels is not too much, and it can be more accurate at the centroid position of the statistical spot, which can effectively reduce the situation in which the center of mass is left and right due to uneven brightness of the spot.
無論如何，任何人都可以從上述例子的說明獲得足夠教導而可據以實施，並據而了解本發明內容確實不同於先前技術，且具有產業上之利用性，及足具進步性。是本發明確已符合專利要件，爰依法提出申請。 In any case, anyone can obtain sufficient teaching from the description of the above examples to implement it, and it is understood that the present invention is indeed different from the prior art, and is industrially usable and progressive. It is the invention that has indeed met the patent requirements and has filed an application in accordance with the law.
100‧‧‧影像檢測儀器 100‧‧‧Image inspection equipment
1‧‧‧自動對焦系統 1‧‧‧Autofocus system
10‧‧‧物鏡 10‧‧‧ Objective
2‧‧‧取像單元 2‧‧‧Image capture unit
20‧‧‧影像檢測單元 20‧‧‧Image detection unit
21‧‧‧影像擷取裝置 21‧‧‧Image capture device
22‧‧‧成像透鏡 22‧‧‧ imaging lens
23‧‧‧濾鏡 23‧‧‧ filter
3‧‧‧照明單元 3‧‧‧Lighting unit
31‧‧‧分光鏡 31‧‧‧beam splitter
32‧‧‧照明裝置 32‧‧‧Lighting device
33‧‧‧準直透鏡 33‧‧‧ Collimating lens
4‧‧‧物件 4‧‧‧ objects
5‧‧‧線形光源 5‧‧‧Linear light source
6‧‧‧光學組件 6‧‧‧Optical components
61‧‧‧會聚透鏡 61‧‧‧Converging lens
62‧‧‧遮光部件 62‧‧‧Shading parts
63‧‧‧反射鏡 63‧‧‧Mirror
64‧‧‧第一分光鏡 64‧‧‧First Beamsplitter
66‧‧‧第二分光鏡 66‧‧‧Second beam splitter
67‧‧‧成像透鏡 67‧‧‧ imaging lens
7‧‧‧影像感測裝置 7‧‧‧Image sensing device
8‧‧‧對焦調整模組 8‧‧‧Focus adjustment module
9‧‧‧驅動裝置 9‧‧‧ drive
Claims (10)
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| Application Number | Priority Date | Filing Date | Title |
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| TW105127152A TWI607253B (en) | 2016-08-24 | 2016-08-24 | Auto-focus system, method and optical imaging inspection apparatus |
| JP2016199546A JP6387381B2 (en) | 2016-08-24 | 2016-10-07 | Autofocus system, method and image inspection apparatus |
| CN201611095248.6A CN107782732B (en) | 2016-08-24 | 2016-12-02 | Automatic focusing system, method and image detection instrument |
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| TW105127152A TWI607253B (en) | 2016-08-24 | 2016-08-24 | Auto-focus system, method and optical imaging inspection apparatus |
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| TWI607253B true TWI607253B (en) | 2017-12-01 |
| TW201809778A TW201809778A (en) | 2018-03-16 |
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| JP (1) | JP6387381B2 (en) |
| CN (1) | CN107782732B (en) |
| TW (1) | TWI607253B (en) |
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| CN109530912B (en) * | 2018-12-28 | 2021-02-09 | 武汉华工激光工程有限责任公司 | Focusing device based on inner coaxiality and focusing method based on inner coaxiality |
| TWI782280B (en) * | 2020-06-01 | 2022-11-01 | 財團法人國家實驗研究院 | Auto focus method for a remote sensing satellite and the satellite therefor |
| TWI786991B (en) | 2021-12-13 | 2022-12-11 | 國立成功大學 | Autofocus system and autofocus method |
| TWI813173B (en) * | 2022-02-18 | 2023-08-21 | 極智光電股份有限公司 | Automatic focusing and imaging system and method、microscope |
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| US20120133819A1 (en) * | 2010-11-25 | 2012-05-31 | Industrial Technology Research Institute | Automatic Focusing Apparatus and Method |
| TW201237534A (en) * | 2011-03-01 | 2012-09-16 | Altek Corp | Auto focusing lens module and calibrating method thereof |
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| TW201237534A (en) * | 2011-03-01 | 2012-09-16 | Altek Corp | Auto focusing lens module and calibrating method thereof |
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Also Published As
| Publication number | Publication date |
|---|---|
| JP2018032005A (en) | 2018-03-01 |
| CN107782732B (en) | 2021-03-02 |
| JP6387381B2 (en) | 2018-09-05 |
| CN107782732A (en) | 2018-03-09 |
| TW201809778A (en) | 2018-03-16 |
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