1321650 九、發明說明： 【發明所屬之技術領域】 本發明係一種關於以背光照射液晶面板並以攝影裝置 觀察液晶面板内部之灰塵等缺陷的液晶面板檢查裝置。 【先前技術】 作為一種以背光照射液晶面板並以攝影裝置觀察液晶 面板内部之灰塵等缺陷的液晶面板檢查裝置，已記载於下 列專利文獻1及專利文獻2。 【專利文獻1】特開平1 1 - 326123號公報 【專利文獻2】特開平1〇一227721號公報 專利文獻1之液晶面板檢查裝置’係將背光配置成與 液晶面板之下面對向，將感測器攝影機配置成與液晶面板 之上面對向。以下，將與感測器攝影機對向之側稱為表面’ 將與背光對向之側稱為背面。藉由點亮背光，並以攝影機 拍攝透射過液晶面板之背光的光，來檢查液晶面板内部的 缺陷此時，不僅液晶面板内部的缺陷，連在液晶面板第 1面之保護膜的傷痕或附著於表面的灰塵等，亦會被攝影 機拍攝出來。因此，專利絲（中，為了能區別内部缺陷 與表面灰塵等’係使用傾斜照明帛，使光可從相對液晶面 板表面呈傾斜之方向照射。f先，關掉背光，僅以傾斜照 明光照：液晶面板表面，並以感測器攝影機拍攝其反射 2此日守映出於感測器攝影機者係液晶面板表面之傷痕或 塵等’液晶面板内部的缺陷則不會映出。其二欠，關掉傾 …日-' 明燈，並點亮背光，以攝影機拍攝其透射光。此時映 5 感測器攝景> 機者’係液晶面板内部的缺陷與液晶面板 2面的傷痕或灰塵之兩者。最後，藉由從背光之攝影影像 貝訊減去傾斜照明光之攝影影像資訊，即可求得僅液晶面 板内部之缺陷。 專利文獻2之液晶面板檢查裝置亦與專利文獻1之裝 同亦即，將電視攝影機配置成與液晶面板之表面對 向將背光配置成與液晶面板之第2面對向。在以背光進 〜έ燈檢查别或後，先關掉背光，僅將傾斜照明光照射液 t面板之表面，並以電視攝影機拍攝其反射光。此時映出 。電視攝影機者，係液晶面板表面側之表面保護膜的傷痕 或保護膜上的灰塵等（以下稱為表面缺陷），液晶面板内部 之缺陷則不會映出。另一方s，進行點燈檢查時，係關掉 斜‘、’、月燈 '點売背光，並以攝影機拍攝其透射光。此時 映出於電視攝影機者’係、液晶面板内部的缺陷與液晶面板 表面的缺陷兩者。將傾斜照明光之攝影影像資訊(反射影像 資訊）與背光之光之攝影影像資訊（透過影像資訊）配合座標 位置來予以比#交’即可判斷出於任__攝影影像資訊中均映 出者為液曰a面板之表面缺陷，而僅於背光之光之攝影影像 貧訊映出者則為液晶面板内部之缺陷。 【發明内容】 己.於上述專利文獻丨與專利文獻2之液晶面板檢查 裝置有下列問題點。此等習知技術中，無法區別附著於液 面板月面側之表面的灰塵、以及液晶面板内部的缺陷。 亦即，即使將傾斜照明光照射於液晶面板表面，附著於背 1321650 面側之表面的灰塵亦不會映出於攝影機之影像。另一方 面’當以背光之光進行拍攝時，由於液晶面板背面側之表 面灰塵與液晶面板内部的缺陷兩者均會映出為影像，因此 無法區別該等影像。又，上述專利文獻1與專利文獻2， 係針對具備有偏光板之液晶面板來檢查其内部灰塵等之有 無’而並未提及任何關於貼合偏光板前的液晶面板。雖若 能在貼合偏光板前之階段明確判斷出灰塵等已進入液晶面 板内部’即無需進行後續徒勞的作業（偏光板貼合作業等）， 但專利文獻1與專利文獻2中，並未提及任何關於當要檢 查無偏光板狀態之液晶面板的内部灰塵等時，須進行哪些 步驟。 本發明之目的為提供一種液晶面板檢查裝置，係使用 攝影裝置來檢查無偏光板狀態之液晶面板的裝置，其能區 別附著於液晶面板兩側表面的灰塵影像與液晶面板内部之 缺陷。 、 本發明之液晶面板檢查裝置具備下列（A)〜（B)。（A)支 樓台’係支樓無偏光板狀態的液晶面板；背光，係配置 成面對該液晶面板之一表面；（c)攝影裝置，係配置成面對 該液晶面板之另一表面；（D)第1偏光板，係配置於該液晶 面板與該背光之間；（E)第2偏光板，係配置於該液晶面板 與该攝影裝置之間；（F)傾斜照明光源，係以既定傾斜角度 將照明光照射於該液晶面板之該一表面，其配置成來自該 傾斜照明光源之照明光不通過該第丨偏光板而照射於該一 表面；（G)切換裝置，係用以切換該背光對液晶面板的照明 7 I321650 與該傾斜照明光源對液晶面板的照明。 傾斜照明光源之照明光，最好係在該液晶面板之該一 表面的任意位置中該傾斜角度均為10〜50度之範圍内。 該切換裝置，可包含配置於液晶面板與背光之間的擋 門。該擋門係能在開放狀態與關閉狀態之間進行切換，開 放狀態係指從背光朝向液晶面板之一表面的照明光通過， 關閉狀態係指截斷從背光朝向液晶面板之一表面的照明 _ 光。藉由擋門的設置，使背光可保持點亮狀態進行照明的 切換。 當液晶面板係由第1邊、第2邊、第3邊、以及第4 邊構成的矩形時，該傾斜照明光源可具備下列0)到（d)。（a) 與該液晶面板之該第1邊平行的第丨側燈，係位於較該液 晶面板之該第1邊更靠近該背光側' 且從該液晶面板中心 觀看時位於較該第i邊更遠的位置；（b)與該液晶面板之該 第2邊平行的第2側燈，係位於較該液晶面板之該第2邊 _ 更罪近该背光側、且從該液晶面板中心觀看時位於較該第 2邊更运的位置，（c)與該液晶面板之該第3邊平行的第3 側燈’係位於較該液晶面板之該第3邊更靠近該背光側、 且從該液晶面板中心觀看時位於較該第3邊更遠的位置；（d) 與该液晶面板之該第4邊平行的第4側燈，係位於較該液 晶面板之該第4邊更靠近該背光側、且從該液晶面板尹心 觀看時位於較該第4邊更遠的位置。 本發明可發揮下述效果’亦即當使用攝影裝置檢查無 偏光板狀態的液晶面板時，能區別附著在液晶面板兩側表 8 面之灰塵影像與液晶面板内部的缺陷。 【實施方式】 以下’參照圖式詳細說明本發明之實施例。圖1係本 电月之液曰曰面板檢查裝置—實施例的構成圖，機械式之構 造部分係以前視截面圖顯示。於面板支撐纟10上面，可 放置貼合偏光板前之狀態的液晶面板12。 於面板支撐台1 〇内部配置有傾斜照明光源2〇、第i 偏光板 22、以及擔银"js； ^ 擴散板24。面板支撐台10透過支柱28 固疋於基座26。於基座26上面固定有背光裝置3〇。於背 光裝置3〇上方配置有擋門32。擋門32可藉由擋門驅動機 構34移動於水平方向(亦即箭頭35之方向此擋門”， 此,開放狀態與關閉狀態之間進行切換，開放狀態係指使 ，月光裝* 30朝向液晶面板12下面之照明光通過的狀 態’關閉狀態係指截斷從背光裝s 3G朝向液晶面板下面 之照明光的狀態。 为光裝置3G ’係透過背光開關36來從背光電源38接 收電力之供應。又，傾斜照明光源、2()，係透過傾斜照明開 關4〇來從傾斜照明電源42接收電力之供應。 於面板支撐台1〇上方配置有作為攝影裝置之CCD攝 影機44。於CCD攝影機44與液晶面板Μ之間配置有第2 偏光板4‘6。CCD$影機44之影像係以影像處理冑48進行 處理’藉此可取得液晶面板12㈣之灰塵或附著於液曰曰 面板12兩側表面之灰塵的影像。所取得之影像可映出於 顯示裝置49的畫面。 、 1321650[Technical Field] The present invention relates to a liquid crystal panel inspection apparatus for irradiating a liquid crystal panel with a backlight and observing defects such as dust inside the liquid crystal panel with a photographing device. [Prior Art] A liquid crystal panel inspection apparatus which irradiates a liquid crystal panel with a backlight and observes defects such as dust inside the liquid crystal panel by a photographing device is described in Patent Document 1 and Patent Document 2 below. [Patent Document 1] Japanese Laid-Open Patent Publication No. Hei No. Hei. No. Hei. No. 227721. The sensor camera is configured to face above the liquid crystal panel. Hereinafter, the side opposite to the sensor camera will be referred to as a surface, and the side opposite to the backlight will be referred to as a back surface. By illuminating the backlight and photographing the light transmitted through the backlight of the liquid crystal panel by the camera, the defect inside the liquid crystal panel is inspected. At this time, not only the defect inside the liquid crystal panel, but also the flaw or adhesion of the protective film attached to the first surface of the liquid crystal panel. The dust on the surface, etc., will also be photographed by the camera. Therefore, the patented wire (in order to distinguish between internal defects and surface dust, etc.) uses a tilting illuminator to illuminate light from a direction opposite to the surface of the liquid crystal panel. f First, turn off the backlight and illuminate only with oblique illumination: The surface of the liquid crystal panel and the reflection of the sensor on the surface of the liquid crystal panel. The defects inside the LCD panel are not reflected on the surface of the liquid crystal panel of the sensor camera. Turn off the tilt-day-'lights, and illuminate the backlight, and shoot the transmitted light with the camera. At this time, the screen of the sensor is reflected.] The player's internal defects in the LCD panel and the scratches or dust on the 2 sides of the LCD panel. Finally, by subtracting the photographic image information of the oblique illumination light from the photographic image of the backlight, the defect inside only the liquid crystal panel can be obtained. The liquid crystal panel inspection device of Patent Document 2 is also related to Patent Document 1. In the same manner, the television camera is arranged to face the surface of the liquid crystal panel, and the backlight is arranged to face the second surface of the liquid crystal panel. After the backlight is turned on or off, the back is turned off. Only the surface of the liquid illuminating liquid t-panel is tilted, and the reflected light is taken by a television camera. At this time, the TV camera is a flaw of the surface protective film on the surface side of the liquid crystal panel or dust on the protective film ( Hereinafter, it is called surface defect), and the defects inside the liquid crystal panel are not reflected. On the other side, when lighting inspection, the oblique ', ', moonlight' point backlight is turned off, and the transmitted light is taken by the camera. At this time, it is reflected in the TV camera's system, the defects inside the LCD panel and the defects on the surface of the LCD panel. The photographic image information (reflected image information) of the oblique illumination light and the photographic image information of the backlight light (through the image) Information) with the coordinate position to compare with #交' can be judged in the __ photographic image information is reflected in the liquid 曰 a panel surface defects, and only the backlight light photographic image poor news The present invention has the following problems in the liquid crystal panel inspection apparatus of the above-mentioned Patent Document 专利 and Patent Document 2. In the prior art, The method distinguishes dust attached to the surface of the meniscus side of the liquid panel and defects inside the liquid crystal panel. That is, even if the oblique illumination light is irradiated onto the surface of the liquid crystal panel, dust adhering to the surface on the back side of the back 1321650 does not reflect. On the other hand, when shooting with backlight light, both the surface dust on the back side of the liquid crystal panel and the defects inside the liquid crystal panel are reflected as images, so the images cannot be distinguished. In the above-mentioned Patent Document 1 and Patent Document 2, the liquid crystal panel including the polarizing plate is used to check the presence or absence of dust inside, and there is no mention of any liquid crystal panel before the polarizing plate is bonded. At the stage, it is determined that dust or the like has entered the inside of the liquid crystal panel, that is, there is no need to carry out subsequent futile work (polarizing plate bonding cooperation, etc.), but Patent Document 1 and Patent Document 2 do not mention anything about checking unpolarized light. What steps must be taken when the internal dust of the liquid crystal panel in the panel state is equal. SUMMARY OF THE INVENTION An object of the present invention is to provide a liquid crystal panel inspection apparatus which is a device for inspecting a liquid crystal panel having no polarizing plate state by using a photographing device, which is capable of distinguishing between a dust image attached to both side surfaces of the liquid crystal panel and a defect inside the liquid crystal panel. The liquid crystal panel inspection device of the present invention has the following (A) to (B). (A) a branch wall of a branch building without a polarizing plate; a backlight disposed to face a surface of the liquid crystal panel; (c) a photographing device configured to face another surface of the liquid crystal panel; (D) the first polarizing plate is disposed between the liquid crystal panel and the backlight; (E) the second polarizing plate is disposed between the liquid crystal panel and the imaging device; and (F) the oblique illumination source is Irradiating illumination light on the surface of the liquid crystal panel, the illumination light from the oblique illumination source is not irradiated to the surface through the second polarizing plate; (G) switching device is used for Switching the illumination of the liquid crystal panel by the backlight 7 I321650 and the illumination of the liquid crystal panel by the oblique illumination source. The illumination light for tilting the illumination source is preferably in the range of 10 to 50 degrees in any position on the surface of the liquid crystal panel. The switching device may include a shutter disposed between the liquid crystal panel and the backlight. The door can be switched between an open state and an off state, the open state refers to the passage of illumination light from the backlight toward one surface of the liquid crystal panel, and the closed state refers to the interception of illumination from the backlight toward one surface of the liquid crystal panel. . By setting the door, the backlight can be kept lit to switch the illumination. When the liquid crystal panel is a rectangle composed of the first side, the second side, the third side, and the fourth side, the oblique illumination light source may have the following 0) to (d). (a) a third side light parallel to the first side of the liquid crystal panel is located closer to the backlight side than the first side of the liquid crystal panel and is located at the i-th side when viewed from the center of the liquid crystal panel a farther position; (b) a second side light parallel to the second side of the liquid crystal panel is located closer to the backlight side than the second side of the liquid crystal panel, and viewed from the center of the liquid crystal panel When the position is more transported than the second side, (c) the third side light 'parallel to the third side of the liquid crystal panel is located closer to the backlight side than the third side of the liquid crystal panel, and The liquid crystal panel is located farther than the third side when viewed from the center; (d) the fourth side light parallel to the fourth side of the liquid crystal panel is located closer to the fourth side of the liquid crystal panel The backlight side is located farther than the fourth side when viewed from the liquid crystal panel. According to the present invention, when the liquid crystal panel having no polarizing plate state is inspected by the photographing device, the dust image adhering to the surface of the liquid crystal panel and the inside of the liquid crystal panel can be distinguished. [Embodiment] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Fig. 1 is a structural view of an embodiment of a liquid helium panel inspection apparatus of the present invention, and a mechanical construction section is shown in a front cross-sectional view. On the panel supporting frame 10, a liquid crystal panel 12 in a state before the polarizing plate is attached can be placed. An inclined illumination light source 2〇, an i-th polarizing plate 22, and a silver-loading “js; ^ diffusing plate 24 are disposed inside the panel supporting table 1 . The panel support table 10 is fixed to the base 26 via the stays 28. A backlight device 3 is fixed on the susceptor 26 . A shutter 32 is disposed above the backlight unit 3〇. The shutter 32 can be moved in the horizontal direction (that is, the door in the direction of the arrow 35) by the door drive mechanism 34, thereby switching between the open state and the closed state, and the open state means that the moonlight is mounted toward the liquid crystal The state in which the illumination light under the panel 12 passes is a state in which the illumination light from the backlight s 3G toward the lower surface of the liquid crystal panel is cut off. The optical device 3G' receives the supply of electric power from the backlight power supply 38 through the backlight switch 36. Further, the illuminating light source and 2() are supplied with electric power from the oblique illumination power source 42 via the tilting illumination switch 4. The CCD camera 44 as an imaging device is disposed above the panel support table 1A. The second polarizing plate 4'6 is disposed between the liquid crystal panel 。. The image of the CCD$4 player 44 is processed by the image processing unit 48. Thus, the dust of the liquid crystal panel 12 (4) can be obtained or attached to both sides of the liquid helium panel 12 An image of the dust on the surface. The image obtained can be reflected on the screen of the display device 49. 1321650
圖2為面板支撐台100之立體圖，將其中一部分剖開 來顯示。目3為面板支撐台10之前視截面圖。於圖2與 圖3中，該面板支撐台10係由上板5〇、突出部52、垂直 部54、以及下板56構成，此等構件形成為一體。於面板 支撐台1〇中央形成大型開口，此開口貫通於上下方向。 上板50之上面為支撐液晶面板12的支撐面。上板別之 支撐面的外形尺寸，係較液晶面板之外形尺寸大些許。突 出部52，係隨著從上板50之外周部向下方往外側傾斜突 出。於突出部52内側形成有光源收容部57，於此收容有 傾斜照明光源20。傾斜照明光源2〇係與液晶面板各邊平 行之細長形狀，在本實施例中係以發光二極體構成。於突 出部52之四個邊分別收容有傾斜照明光源2〇。 垂直部54，係較突出部52位於内側的位置，具有與 上板50大致相同程度之外形尺寸。如圖3所清楚顯示' 於垂直部54内壁形成有段部58，於該段部58處固定有擴 散板24與第1偏光板22。下板56，係從垂直部54下端 沿水平方向往外側突出。下板5 6之下面由支柱2 8所支撐。 圖3中，液晶面板12之形狀為矩形，具備第丨邊第 2邊、第3邊、以及第4邊。又，傾斜照明光源2〇，亦與 液晶面板之各邊對應合計具備有4個側燈。例如，第1側 燈2〇a，係位於液晶面板12之第i邊Ua附近，且位於較 第1邊1 3a更靠近背光側的位置、且從液晶面板的中心 觀看時位於較第丨邊13a更遠的位置（在圖3中為位於較第 1邊13a更左側的位置藉由以此方式配置側燈，來自側 1^21650 龙之狀態。當考量由兩個偏光板22，46與液晶面板12構 成之液晶裝置時’此液晶裝置為截斷光通過之模式（遮光模 式）。此時’當以背光之光68照射液晶面板12時，在從CCD 攝影機44觀看的情形下，液晶面板12整體看起來較暗。 其理由如下。當背光之光68通過擴散板24與第1偏光板 22時’會成為僅於一方向振動的直線偏光76。此直線偏 光76 ’其偏光軸因液晶面板12而旋轉9〇度。如此，偏光 轴已旋轉之直線偏光即無法通過第2偏光板46。因此，以 液晶裝置整體來看為遮光模式。 然而’當上述直線偏光76照射於液晶面板12内部的 灰塵78時、亦即照射於存在於2片玻璃板8〇，82所夾之 二間中的灰塵78時，光即會產生漫反射，使偏光狀態變 化。因此’來自灰塵78之散射光84之一部分可通過第2 偏光板46而到達CCD攝影機44。其結果，灰塵78於影 像映出為亮點。又，附著於液晶面板12背面側之表面的 人塵86亦同樣地，光在該處散射，而該散射光92即映出 為儿點而附著於液晶面板12表面側之表面的灰塵8 8， 政射光94亦映出為免點。如此一來，液晶面板I]之内 部灰塵78與附著於表面之灰塵86，88兩者，皆於cCD攝 影機44之影像映出為亮點。 其次，切換至傾斜照明《圖6係顯示關閉擋門32並點 売傾斜照明光源20的狀態。雖然背光裝置30為點亮狀態， 但由於措門32為關閉的狀態，因此背光裝置30之光被擋 門32遮蔽而不會到達液晶面板12的背面。 12 1321650 傾斜妝明光源20之光係以既定傾斜角照射液晶面板i2 的月面。§考里位於圖6左側之傾斜照明光源時朝 向液晶面板12之四個邊中最接近傾斜照明光源20之邊60 的光62、與液晶面板12之背面所夾角度為又，朝向 距離該傾斜照明光源2Q最遠之邊64的光線&與液晶面 板12之背面所夾角度為μ。因此，在液晶面板12之背面 的㈣位置，從傾斜照明光源20照射之光與液晶面板12 之月面所夾角度0，其範圍均在到U之間。為了不映 出液晶面板内部缺陷而僅映出液晶面板兩側表自的灰塵， 其理想角度0為10〜50度的範圍内。本實施例中，0卜Μ 度，02=15度。四個傾斜照明光源2〇之任一個與液晶面板 之位置關係均相同。 圖7,係以示意方式顯示圖6之狀態中因灰塵導致之 光的漫反射狀態。當以傾斜照明光源2〇從傾斜方向將光 照射至液晶面板12之背面時，即會因内部灰塵78使漫反 射光90之強度減弱，而使映出於CCD攝影機44之亮點強 度減弱。其理由如下。2片玻璃板80, 82間之間隙（3例如 為5//m左右，内部灰塵78之最大厚度亦為5“m左右。 此種較薄之灰塵78 ’當從傾斜方向照射光時，漫反射至CCD 攝影機44方向之光9〇的強度即會減弱。另一方面，液晶 面板12之背面或表面的灰塵86, 88例如為數十左右 的尺寸，且為立体形狀。此種因灰塵86，88而漫反射的光 92, 94，會於CCD攝影機44之影像映出為亮點。 由於傾斜照明光源20係傾斜照射於液晶面板12之背 13 ^21650 面’因此透射過液晶面板12之光會直接通過第2偏光板 46(雖說通過’但也僅為與特定偏光方向一致之一部分光）， 不會到達CCD攝影機44。因灰塵78, 86, 88導致之漫反射 光中與特定之偏光方向一致的光，會通過第2偏光板46 到達CCD攝影機44。 以影像處理部48(參照圖1)CCD處理攝影機44之影像 時’當設定既定臨限值並僅將大於該臨限值之檢測強度的 • 像素資料作為亮點取出後，在圖7之狀態下，強度較弱之 因内部灰塵78而產生之漫反射光90即會從影像處理部48 的輸出消失’而僅將因表面灰塵86，88而產生之漫反射光 92，94作為免點取出。因此’從背光之光之亮點位置資料 —減去傾斜照明光源之亮點位置資料後，即會僅剩下内部灰 -塵之壳點位置資料，藉此即能區別内部灰塵與表面灰塵。 其次’說明檢測液晶面板之内部灰塵的順序。圖1中， 使身光開關3 6導通來點亮背光裝置3 〇。先將擂門3 2關閉。 鲁使傾斜照明開關4〇斷開。於面板支撐台1 〇放置貼合偏光 板别之液晶面板12。開啟擋門32，使背光裝置3〇之光通 過擴散板24與第丨偏光板22照射於液晶面板12背面。 捿著，以CCD攝影機44拍攝液晶面板12。此時為圖5所 示之狀態。 “其次，關閉擋門32，截斷朝向液晶面板丨2背面之背 光裝置30的光。先使背光開關36為導通狀態。然後使傾 •=照明開關40導通。不關掉背光裝置3〇之理由如下所述。 田使用螢光燈作為背光裝置3〇時，由於背光裝置3〇從點 14 1321650 ^到穩定狀態為止須花費某程度的時間，因此為了縮短當 才《查複數個液晶面板時的循援拉μFig. 2 is a perspective view of the panel support table 100, a part of which is shown cut away. Head 3 is a front cross-sectional view of the panel support table 10. In Figs. 2 and 3, the panel support table 10 is composed of an upper plate 5, a projection 52, a vertical portion 54, and a lower plate 56, and these members are integrally formed. A large opening is formed in the center of the panel support table 1 , and the opening passes through the vertical direction. The upper surface of the upper plate 50 is a support surface for supporting the liquid crystal panel 12. The outer dimensions of the support surface are slightly larger than the outer dimensions of the liquid crystal panel. The projecting portion 52 protrudes obliquely outward from the outer peripheral portion of the upper plate 50. A light source accommodating portion 57 is formed inside the protruding portion 52, and the oblique illuminating light source 20 is accommodated therein. The oblique illumination source 2 is an elongated shape that is parallel to each side of the liquid crystal panel, and is formed of a light-emitting diode in this embodiment. The oblique illumination light source 2 is accommodated on each of the four sides of the projection 52. The vertical portion 54 is located at the inner side of the projecting portion 52 and has a shape similar to that of the upper plate 50. As clearly shown in Fig. 3, a segment 58 is formed on the inner wall of the vertical portion 54, and the diffusion plate 24 and the first polarizing plate 22 are fixed to the segment 58. The lower plate 56 protrudes outward from the lower end of the vertical portion 54 in the horizontal direction. The lower surface of the lower plate 5 6 is supported by the struts 28. In Fig. 3, the liquid crystal panel 12 has a rectangular shape and includes a second side, a third side, and a fourth side of the third side. Further, the illumination source 2 is tilted, and four side lamps are provided in total for each side of the liquid crystal panel. For example, the first side lamp 2〇a is located near the i-th side Ua of the liquid crystal panel 12, and is located closer to the backlight side than the first side 13a, and is located at the third side when viewed from the center of the liquid crystal panel. 13a farther position (in Figure 3, the position is located further to the left than the first side 13a by configuring the sidelights in this way, from the state of the side 1^21650 dragon. When considering the two polarizers 22, 46 with When the liquid crystal panel 12 constitutes a liquid crystal device, the liquid crystal device is in a mode in which light is cut off (light-shielding mode). At this time, when the liquid crystal panel 12 is illuminated by the backlight 68, the liquid crystal panel is viewed from the CCD camera 44. The whole 12 looks dark. The reason is as follows: When the backlight light 68 passes through the diffusing plate 24 and the first polarizing plate 22, it will become a linearly polarized light 76 that vibrates in only one direction. This linear polarized light 76' has a polarization axis due to liquid crystal. The panel 12 is rotated by 9 degrees. Thus, the linear polarized light that has been rotated by the polarizing axis does not pass through the second polarizing plate 46. Therefore, the liquid crystal device as a whole is in a light blocking mode. However, when the linear polarized light 76 is irradiated onto the liquid crystal panel 12, Internal dust 78 At the time, that is, when the dust 78 is present in two of the two glass plates 8 and 82, the light is diffusely reflected and the polarization state is changed. Therefore, 'a portion of the scattered light 84 from the dust 78 The CCD camera 44 can be reached by the second polarizing plate 46. As a result, the dust 78 is reflected as a bright spot on the image, and the dust 86 attached to the surface on the back side of the liquid crystal panel 12 is similarly scattered by the light. The scattered light 92 is reflected as a dust and adheres to the surface of the surface side of the liquid crystal panel 12, and the political light 94 is also reflected as a point of avoidance. Thus, the internal dust 78 and the adhesion of the liquid crystal panel I] Both the dust 86, 88 on the surface are reflected as bright spots on the image of the cCD camera 44. Next, switching to the oblique illumination "Figure 6 shows the state in which the shutter 32 is closed and the illumination source 20 is tilted. Although the backlight 30 is in the lighting state, but since the door 32 is in the closed state, the light of the backlight device 30 is shielded by the shutter 32 and does not reach the back surface of the liquid crystal panel 12. 12 1321650 The light of the tilting light source 20 is inclined at a predetermined angle. The angle of the moonlit LCD panel i2 The light 62 which is closest to the side 60 of the tilting illumination source 20 among the four sides of the liquid crystal panel 12 when the oblique illumination source is located on the left side of FIG. 6 is opposite to the back surface of the liquid crystal panel 12, and the orientation distance is The angle between the light source & the farthest edge 64 of the oblique illumination source 2Q and the back surface of the liquid crystal panel 12 is μ. Therefore, the light irradiated from the oblique illumination source 20 and the liquid crystal panel 12 are located at the (four) position on the back surface of the liquid crystal panel 12. The angle of the lunar surface is 0, and the range is between U and U. In order not to reflect the internal defects of the liquid crystal panel, only the dust on the sides of the liquid crystal panel is reflected, and the ideal angle 0 is in the range of 10 to 50 degrees. . In this embodiment, 0 Μ degree, 02 = 15 degrees. The positional relationship of any of the four oblique illumination sources 2 is the same as that of the liquid crystal panel. Fig. 7 is a view showing a state of diffuse reflection of light due to dust in the state of Fig. 6 in a schematic manner. When the light is irradiated from the oblique direction to the back surface of the liquid crystal panel 12 by the oblique illumination light source 2, the intensity of the diffuse reflection light 90 is weakened by the internal dust 78, and the intensity of the bright spot reflected by the CCD camera 44 is weakened. The reason is as follows. The gap between the two glass plates 80 and 82 (3 is, for example, about 5/m, and the maximum thickness of the internal dust 78 is also about 5"m. This thin dust 78' is when the light is irradiated from the oblique direction. The intensity of the light 9 反射 reflected in the direction of the CCD camera 44 is weakened. On the other hand, the dust 86, 88 on the back surface or surface of the liquid crystal panel 12 is, for example, a size of several tens of degrees and has a three-dimensional shape. The light, 92, 94, which is diffusely reflected, is reflected as a bright spot on the image of the CCD camera 44. Since the oblique illumination source 20 is obliquely irradiated on the back surface of the liquid crystal panel 12, the light is transmitted through the liquid crystal panel 12. It will pass directly through the second polarizing plate 46 (although through 'but only a part of the light in the direction of the specific polarizing direction), it will not reach the CCD camera 44. The diffuse reflected light and the specific polarized light caused by the dust 78, 86, 88 The light having the same direction passes through the second polarizing plate 46 to reach the CCD camera 44. When the image processing unit 48 (see Fig. 1) CCD processes the image of the camera 44, 'when setting a predetermined threshold and only exceeding the threshold value Detecting intensity • Pixel data as bright After the removal, in the state of Fig. 7, the diffuse reflection light 90 generated by the internal dust 78 with weaker intensity disappears from the output of the image processing unit 48, and only the diffuse reflection due to the surface dust 86, 88 is generated. The light 92, 94 is taken out as a point-free. Therefore, after subtracting the highlight position data of the oblique illumination source from the bright spot position data of the backlight, only the internal gray-dust shell position data is left, thereby The internal dust and surface dust are distinguished. Next, the order of detecting the internal dust of the liquid crystal panel is explained. In Fig. 1, the body light switch 36 is turned on to illuminate the backlight device 3. The trickle 3 2 is turned off first. The switch 4 is disconnected. The liquid crystal panel 12 of the polarizing plate is placed on the panel supporting table 1 . The shutter 32 is opened, and the light of the backlight device 3 is irradiated to the liquid crystal panel 12 through the diffusing plate 24 and the second polarizing plate 22 . Next, the liquid crystal panel 12 is photographed by the CCD camera 44. At this time, it is in the state shown in Fig. 5. "Secondly, the shutter 32 is closed, and the light of the backlight device 30 facing the back surface of the liquid crystal panel 2 is cut off. 36 is the conduction state Then, the tilting light switch 40 is turned on. The reason why the backlight unit 3 is not turned off is as follows. When the field uses the fluorescent lamp as the backlight unit 3, since the backlight unit 3 is turned from the point 14 1321650 ^ to the steady state. It takes a certain amount of time, so in order to shorten the time when it is used to check the number of LCD panels
盾衣時間’最好是使背光裝置3 0 保持點亮狀態。進行傾钭日3 ηΒ喊 I 離^ ^ 丄丁貝斜照明時，由於擋門32為關閉狀 、、’因此走光之光不會照射至液晶面板。傾斜照明光源20 之光’係從傾斜方向柙射5你a ’、 π“·'射至液晶面板12的背面。著， 以CCD攝影機44拍攝 耆 熊。 低1 ζ此時為圖7所示之狀 圖8,係將以上述方式拍攝之液晶面板之影像一部分 大顯示的示意圖。往上下方向與左右方向延伸之線為間 極線70與資料線72 《線為間 被相鄰之2條閘極線7〇與相鄰之2 2料線72包圍的區域為-個像素。圖8⑷，係以背光 之光所拍攝者。位於液θ而 部内部灰塵係映出為亮 而附者於液晶面板之表側或背側之表面的外部灰塵 亦映出為亮點98(在本例中為3個^ 明亦、s & 4A视& ;圃8(B)，係以傾斜照 先源所拍攝者。位於液晶面板内部之内部灰塵的亮點％ 塵^而僅映出附著於液晶面板表側或背側表面之外部灰 塵的免點98。雖因内部灰塵產生之亮點％也許不會完全 4失’但藉由僅將既定臨限值以上之光強度取出作為： :的資料，來使因内部灰塵產生之亮·點9 :看 為消失。 只饤囬术有 影像處理部48(參照圖υ，是儲存圖8(a)之 點的座標位置資料與圖8(B)之影像中亮點的座標位置二 =可將前者之資料與後者之資料的共通部分(此為因外： 火塵產生之亮點的座標位置#料）進行f料删除。剩下來之 15 1321650 資料，即為因内部灰塵產生之亮點的座標位置資料。藉此， 可掌握内部灰塵的有無、以及其位置。 上述的實施例中，雖使用擋門來截斷背光的光，但亦 可將擋門去除。此種狀況下’在進行傾斜照明時係關掉背 光。 【圖式簡單說明】 圖1 ’係本發明之液晶面板檢查裝置一實施例的構成 圖。 圖2，係面板支撐台的立體圖。 圖3,係面板支撐台的前視截面圖。 圖4，係僅顯示照明系統與拍攝系統的前視截面圖。 圖5，係以示意方式顯示圖4之狀態中、因灰塵導致 之光之漫反射狀態的前視截面圖。 圖6，係顯示關閉擋門並使傾斜照明光源點亮之狀態 之與圖4相同的前視截面圖。 圖7，係以示意方式顯示圖6之狀態中、因灰塵導致 之光之漫反射狀態，係與圖5相同之前視截面圖。 圖8(A)、（B)，係將液晶面板之影像一部分放大顯示 的示意圖。 【主要元件符號說明】 10 面板支樓台 12 液晶面板 20 傾斜照明光源 22 第1偏光板 1321650 24 擴散板 30 背光裝置 32 擋門 34 擋門驅動機構 36 背光開關 38 背光電源 40 傾斜照明開關 42 傾斜照明電源 44 CCD攝影機 46 第2偏光板 48 影像處理部 17The shield time ' is preferably such that the backlight unit 30 remains lit. When the tilting day 3 η Β I 离 离 离 ^ ^ ^ ^ ^ ^ 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜 斜The light of the oblique illumination source 20 is emitted from the oblique direction by 5 a', π"·' to the back of the liquid crystal panel 12. The raccoon is photographed by the CCD camera 44. The low 1 ζ is shown in Fig. 7 Fig. 8 is a schematic view showing a part of the image of the liquid crystal panel taken in the above manner, and the line extending in the up and down direction and the left and right direction is the interpolar line 70 and the data line 72. The area surrounded by the gate line 7〇 and the adjacent 2 2 material line 72 is -pixel. Figure 8(4) is the person photographed by the backlight. The liquid is located in the liquid θ and the dust inside is bright. The external dust on the front side or the back side of the liquid crystal panel is also reflected as a bright spot 98 (in this example, 3 明 亦, s & 4A 视 & 圃 8 (B), The person who is photographed. The bright spot of the internal dust inside the liquid crystal panel is dusty, and only the point 98 attached to the external dust on the front or back side of the liquid crystal panel is reflected. Although the bright spot due to internal dust may not be completely 4 Lost' but by taking only the light intensity above the established threshold as: Light due to internal dust. Point 9: It is seen as disappearing. Only the image processing unit 48 (see Figure υ, is the coordinate position data for storing the point of Fig. 8(a) and the image of Fig. 8(B). The coordinate position of the highlight 2 = the common part of the data of the former and the latter's data (this is the coordinate position of the highlight of the fire dust). The remaining 15 1321650 data is the cause. The coordinate position data of the bright spot generated by the internal dust can be used to grasp the presence or absence of internal dust and its position. In the above embodiment, the shutter is used to cut off the backlight light, but the door can be removed. In the case of the backlight illumination, the backlight is turned off. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a configuration diagram of an embodiment of a liquid crystal panel inspection apparatus of the present invention. Fig. 2 is a perspective view of a panel support table. Fig. 4 is a front cross-sectional view showing only the illumination system and the photographing system. Fig. 5 is a schematic view showing the diffuse reflection state of light due to dust in the state of Fig. 4. Front view of the section. Figure 6 is a front cross-sectional view similar to Figure 4 showing a state in which the shutter is closed and the tilting illumination source is illuminated. Figure 7 is a schematic representation of the diffuse reflection of light due to dust in the state of Figure 6. The state is the same as that of Fig. 5. Fig. 8(A) and (B) are schematic diagrams showing a part of the image of the liquid crystal panel in an enlarged manner. [Description of main components] 10 Panel support 12 Liquid crystal panel 20 Inclined illumination Light source 22 First polarizing plate 1321650 24 Diffuser 30 Backlight 32 Door 34 Door drive mechanism 36 Backlight switch 38 Backlight power supply 40 Tilting light switch 42 Tilting power supply 44 CCD camera 46 Second polarizing plate 48 Image processing unit 17