201132963 六、發明說明： 【發明所屬之技術領域】 本發明係關於一種已貼合偏光板之液晶面板之缺陷檢查 方法。詳細而言，係關於一種於未使液晶面板驅動之狀態 下檢查已貼合偏光板之液晶面板之缺陷的方法》 ' 【先前技術】 液晶電視等係將偏光板於液晶面板之兩面上貼合成正交 偏光而製造。 缺陷檢查係對所使用之原材料、主要製造步驟中所獲得 之構件進行檢查’但亦對已貼合偏光板之液晶面板進行檢 查。 作為已貼合偏光板之液晶面板之缺陷檢查方法，亦有使 液晶面板驅動而進行檢查之方法，但必需進行施加有電荷 之驅動器之搭載等，於檢查出缺陷之情形時為了進行維 修、重做而需要花功夫進行驅動器之卸除等。因此，較佳 為不搭載驅動器，於液晶面板未驅動之狀態下檢查已貼合 偏光板之液晶面板之缺陷。 已知對於液晶面板未驅動之狀態下可見光不透過之常蓴 . ⑯晶之情形而檢查液晶面板内之異物的方法(例如，參照 _ JP 2004 77261 ·Α)。該方法係將液晶面板内之異物作為亮 點而檢測。 然而’作Α已貼合偏光板之液晶面板之缺陷多種多樣 有糊狀物、膜之碎屑等之異物、空氣之捲入、刮痕等^ 等缺陷有時無法根據其形態等而檢測出。期待一種可無= 153880.doc 201132963 漏地檢測出已貼合偏光板之液晶面板之缺陷的方法。 本發明之目的在於，知;供一種於未使液晶面板驅動之狀 態下可無遣漏地檢測出已貼合偏光板之液晶面板之缺陷的 方法。 本發明者對在未使液晶面板驅動之狀態下檢查已貼合偏 光板之液晶面板之缺陷的方法進行努力研討後結果發現， 藉由（1)照射可見光進行檢查並且（2)照射近紅外線進行檢 查而可無遺漏地檢測出缺陷，從而完成本發明。 【發明内容】 即’本發明包含以下所述。 Π]—種已貼合偏光板之液晶面板之缺陷檢查方法，其包括 對已貼合偏光板之液晶面板於未使液晶面板驅動之狀態下 自一面照射光，檢測來自另一面之透過光，並進行信號處 理，該方法係包括可見光照射之檢查、及近紅外線照射之 檢查。 [2] 如[1]之方法’其中可見光照射之光源為金屬齒化物 燈’近紅外線照射之光源為齒素燈，透過光之檢測係使用 CeD(Chairge Coupled Device，電荷耦合器件）相機進行。 [3] 如[1 ]或[2]之方法’其中包括於檢測透過光並進行信號 處理時，將與來源於黑矩陣之格子狀之圖案相對應之週期 性之圖案的信號預先輸入至信號處理裝置，並取消所檢測 之該週期性之圖案之信號而設定信號之基準線。 根據本發明之方法，可發揮以下效果：於未使液晶面板 驅動之狀態下’可無遺漏地檢測出已貼合偏光板之液晶面 153880.doc 201132963 板之缺陷。 【實施方式】 偏光板及液晶面板於被製造之時間點，通常要進行各種 缺陷檢查，並使用無缺陷之偏光板及液晶面板進行貼合， 但會混入無法檢測出缺陷之具有缺陷之偏光板或液晶面 板’或貼合時會捲入異物或空氣，從而導致已貼合偏光板 之液晶面板中存在缺陷。 偏光板通常為如下構成··於偏光膜之兩面上貼合有保護 膜’於其表面上經由黏著劑而貼合有保護膜、分離膜。 作為主要之缺陷，有將分離膜剝離並將偏光板貼合於液 晶面板時膜之碎屑等異物或空氣之捲入、黏著劑之塊、損 傷等。 再者’於液晶電視等中，於偏光板上進而貼合有相位差 板、防眩膜等’通常’多為將該等預先貼合而形成多層 膜，並將其貼合於液晶面板。於本發明中，亦以貼合有該 多層膜之液晶面板作為對象。 缺陷檢查係自已貼合偏光板之液晶面板之一面照射光， 並檢測來自另一面之透過光（已透過該液晶面板之透過光） • 而進打。圖1中表示缺陷檢查裝置之模式圖。於已貼合偏 • 光板之液晶面板1之下方配置有光源2 ,上方配置有相機 3且使已貼合偏光板之液晶面板一邊移動一邊進行檢 查由彳5號處理裝置4處理來自相機之信號，並判斷有無 缺陷。 本發明中’藉由下述方法進行該液晶面板之缺陷檢查： 153880.doc 201132963 (1)可見光照射之檢查，即，對已貼合偏光板之液晶面板於 未使液晶面板驅動之狀態下自一面照射可見光，檢測來自 另一面之透過光，並進行信號處理；以及（2)近紅外線照射 之檢查，即，對該液晶面板於未使液晶面板驅動之狀態下 自一面照射近紅外線，檢測來自另一面之透過光，並進行 信號處理。 可見光照射之檢查與近紅外線照射之檢查中之任一者可 先進行，但不同時進行。 作為發出可見光之光源，可舉出金屬函化物燈。金屬鹵 化物燈主要發出約300〜700 nmi可見光。作為發出近紅外 線之光源之例，可舉出鹵素燈。例如色溫35〇〇。尺之鹵素燈 以波長約700 nm附近為峰值發出3〇〇〜78〇 nm之可見光及 780〜2000 nm之近紅外光。 若將偏光板貼合成正交偏光，即，將2塊偏光板以透過 軸正交之狀態而貼合，則於液晶面板未驅動之狀態下可見 光幾乎不透過，但近紅外線相當強地透過。圖2中模式性 表示偏光板於正交偏光狀態時之透光性（實線）。 作為檢測透過光之相機，通常使用CCD相機。ccd相機 不僅對可見光而且對近紅外線亦具有感度。圖2中模式性 表示CCD之感度特性（虛線）。 由信號處理裝置處理來自相機之信號，並進行缺陷之檢 測。對所得之信號強度設置臨限值，於超過其之情形時為 缺陷。 關於所使用之臨限值，於照射可見光、近紅外線之任一 153880.doc • 6 · 201132963 者而進行檢查之方法中’兩者可使用相同之臨限值，亦可 使用不同之臨限值進行檢查。例如，將基準線設為〇，將 白（亮度高於基準線）側、黑（亮度低於基準線）側分別以 • 32000灰階表現，將5000灰階設為臨限值，於5〇〇〇灰階以 上之情形時為缺陷。 雖目視難以確認，但利用CCD相機可檢測出來源於黑矩 陣之格子狀之圖案。將與該格子狀之圖案相對應之週期性 之圖案之信號預先輸入至信號處理裝置，並取消所檢測之 週期性之圖案之信號而設定基準線。求出來自該基準線之 灰階。 了見光照射之檢查與近紅外線照射之檢查並無特別限 疋’可任一者先進行，而且，亦可將可見光與近紅外線分 另J同時照射至液晶面板之不同部位而進行檢查，但沒有將 可見光與近紅外線重疊照射（同時照射至同一部位）之情 形。可舉出以下方法等：配置各個光源及CCD相機，使已 貼合偏光板之液晶面板移動而依次檢查；配置任一光源與 一台CCD相機，於一方之光照射之檢查結束後，更換光源 而進行另一方之光照射之檢查。 ' 再者’作為所使用之CCD相機之攝像元件，可為線感測 • 器亦可為區域感測器。 實施例 U下’以實施例表示檢查方法，但本發明並不限定於該 實施例。 實施例1 153880.doc 201132963 與圖1所示同樣地，於兩面已貼合偏光板之液晶面板之 下方配董有光源，上方配置有相機，且使於兩面以其透過 轴正父之方式貼合有偏光板之液晶面板一邊移動一邊進行 缺陷檢查。使兩面已貼合偏光板之液晶面板進行上下反 轉’即’於製成電視機之情形時，自表面側及背面側之兩 方進行檢查。 使用金屬鹵化物燈及_素燈作為光源，使用CCd相機作 為相機’且使用光學圖像處理外觀檢查裝置（KUB〇TEC (股）製）作為信號處理裝置而進行檢查。再者，以一方之燈 進^亍光照射之檢查後’換成另一方之燈進行另一方之光照 射之檢查。 於檢查對象之兩面已貼合偏光板之液晶面板係將偏光板 Sumikalan(註冊商標）（住友化學（股）製）之分離膜去除而貼 合於37型電視用液晶面板者。 於信號處理裝置中，為了取消來源於黑矩陣之週期性之 圖案而預先輸入有與其相對應之週期性之圖案之信號，取 消所檢測之週期性之圖案之信號而設定基準線。 將基準線設為〇，於白側、黑側分別設定32000灰階，使 用金屬鹵化物燈之情形時將1 〇〇〇灰階設為臨限值，使用南 素燈之情形時將5〇〇〇灰階設為臨限值，於各自臨限值以上 之情形時為缺陷。 將檢測缺陷之例示於表1。 153880.doc 201132963 [表1]201132963 VI. Description of the Invention: [Technical Field] The present invention relates to a defect inspection method for a liquid crystal panel to which a polarizing plate has been attached. More specifically, the present invention relates to a method of inspecting a defect of a liquid crystal panel to which a polarizing plate has been attached without driving the liquid crystal panel. [Prior Art] A liquid crystal television or the like laminates a polarizing plate on both sides of a liquid crystal panel. Manufactured by orthogonal polarization. The defect inspection checks the raw materials used and the components obtained in the main manufacturing steps. However, the liquid crystal panel to which the polarizing plate has been attached is also inspected. As a method of inspecting a defect of a liquid crystal panel to which a polarizing plate is attached, there is a method of driving a liquid crystal panel to perform inspection. However, it is necessary to mount a driver to which an electric charge is applied, and to perform maintenance and heavy weight when detecting a defect. Doing it takes a lot of effort to remove the drive. Therefore, it is preferable that the driver is not mounted, and the defect of the liquid crystal panel to which the polarizing plate has been attached is inspected while the liquid crystal panel is not driven. A method of inspecting foreign matter in a liquid crystal panel in the case where the visible light is not transmitted in a state where the liquid crystal panel is not driven is known (for example, refer to _ JP 2004 77261 Α). This method detects foreign matter in the liquid crystal panel as a bright spot. However, defects such as liquid crystal panels that have been bonded to a polarizing plate are various, such as foreign matter such as paste, film debris, air entrapment, scratches, etc., and defects cannot be detected depending on the form or the like. . It is expected that a method of detecting the defect of the liquid crystal panel to which the polarizing plate has been attached can be detected by the absence of 153880.doc 201132963. SUMMARY OF THE INVENTION An object of the present invention is to provide a method for detecting a defect of a liquid crystal panel to which a polarizing plate has been attached without detecting a state in which the liquid crystal panel is not driven. The inventors of the present invention conducted an intensive examination of a method of inspecting a defect of a liquid crystal panel to which a polarizing plate has been attached without driving a liquid crystal panel, and found that (1) irradiation with visible light is performed and (2) irradiation of near infrared rays is performed. The inspection can be carried out without fail to detect the defect, thereby completing the present invention. SUMMARY OF THE INVENTION The present invention includes the following. Π] - a method for inspecting a defect of a liquid crystal panel to which a polarizing plate has been attached, which comprises irradiating light from one side of a liquid crystal panel to which a polarizing plate has been attached without detecting the liquid crystal panel, and detecting transmitted light from the other surface, And performing signal processing, which includes inspection of visible light irradiation and inspection of near infrared radiation. [2] The method according to [1], wherein the light source for the visible light irradiation is a metal toothed lamp, and the light source for the near-infrared light is a tooth light, and the light transmission is detected by a CeD (Chairge Coupled Device) camera. [3] The method of [1] or [2] includes detecting a transmitted light and performing signal processing, and inputting a signal of a periodic pattern corresponding to a lattice-like pattern derived from a black matrix to a signal in advance Processing the device and canceling the detected signal of the periodic pattern to set the reference line of the signal. According to the method of the present invention, it is possible to detect the defect of the liquid crystal panel 153880.doc 201132963 which has been bonded to the polarizing plate without causing the liquid crystal panel to be driven. [Embodiment] When a polarizing plate and a liquid crystal panel are manufactured, various defect inspections are usually performed, and a non-defective polarizing plate and a liquid crystal panel are used for bonding, but a defective polarizing plate which cannot detect a defect is mixed. Or the liquid crystal panel 'or when it is attached, foreign matter or air may be caught, resulting in defects in the liquid crystal panel to which the polarizing plate has been attached. The polarizing plate is usually configured as follows: A protective film is bonded to both surfaces of the polarizing film, and a protective film or a separation film is bonded to the surface thereof via an adhesive. As a main defect, foreign matter such as debris of the film or air entrapment, a block of the adhesive, damage, and the like are obtained when the separation film is peeled off and the polarizing plate is bonded to the liquid crystal panel. Further, in a liquid crystal television or the like, a retardation film, an anti-glare film, or the like is bonded to a polarizing plate. Usually, a plurality of films are formed in advance so as to be bonded to each other, and bonded to a liquid crystal panel. In the present invention, a liquid crystal panel to which the multilayer film is bonded is also targeted. The defect inspection is to irradiate light from one surface of the liquid crystal panel to which the polarizing plate is attached, and to detect the transmitted light from the other surface (the transmitted light that has passed through the liquid crystal panel). Fig. 1 is a schematic view showing a defect inspection device. The light source 2 is disposed below the liquid crystal panel 1 to which the polarizing plate is attached, and the camera 3 is disposed above, and the liquid crystal panel to which the polarizing plate is attached is moved while being inspected. The processing signal from the camera is processed by the No. 5 processing device 4. And judge whether there is any defect. In the present invention, the defect inspection of the liquid crystal panel is performed by the following method: 153880.doc 201132963 (1) Inspection of visible light irradiation, that is, the liquid crystal panel to which the polarizing plate has been attached is not driven by the liquid crystal panel. One side illuminates visible light, detects transmitted light from the other side, and performs signal processing; and (2) inspection of near-infrared ray illumination, that is, the liquid crystal panel is irradiated with near-infrared rays from one side without driving the liquid crystal panel, and the detection is from The other side transmits light and performs signal processing. Any of the inspection of visible light irradiation and the inspection of near-infrared radiation may be performed first, but not at the same time. As a light source which emits visible light, a metallization lamp is mentioned. Metal halide lamps emit approximately 300 to 700 nmi of visible light. As an example of a light source that emits near-infrared rays, a halogen lamp can be cited. For example, the color temperature is 35 〇〇. The halogen lamp of the ruler emits visible light of 3 〇〇 to 78 〇 nm and near infrared light of 780 to 2000 nm at a peak of about 700 nm. When the polarizing plates are bonded to the orthogonal polarized light, that is, the two polarizing plates are bonded in a state in which the transmission axes are orthogonal to each other, the visible light is hardly transmitted while the liquid crystal panel is not driven, but the near-infrared rays are transmitted relatively strongly. Fig. 2 schematically shows the light transmittance (solid line) of the polarizing plate in the state of the orthogonal polarization. As a camera that detects transmitted light, a CCD camera is usually used. The ccd camera is sensitive not only to visible light but also to near infrared rays. In Fig. 2, the sensitivity characteristic (dashed line) of the CCD is schematically represented. The signal from the camera is processed by the signal processing device and the defect is detected. A threshold is set for the resulting signal strength, which is a defect when it exceeds its condition. Regarding the threshold value used, in the method of inspecting any of the visible light and near-infrared rays, 153880.doc • 6 · 201132963, 'the same threshold can be used for both, and different thresholds can be used. checking. For example, set the baseline to 〇, white (brighter than the baseline) side, black (brightness below the baseline) side with • 32000 grayscale, and 5000 grayscale as the threshold, at 5〇 It is a defect when the gray scale is above. Although it is difficult to confirm visually, a grid-like pattern derived from a black matrix can be detected by a CCD camera. A signal of a periodic pattern corresponding to the lattice pattern is input to the signal processing device in advance, and a signal of the detected periodic pattern is canceled to set a reference line. Find the gray scale from the baseline. There is no particular limitation on the inspection of the light exposure and the inspection of the near-infrared radiation. In either case, the visible light and the near-infrared light may be simultaneously irradiated to different parts of the liquid crystal panel to be inspected, but There is no case where the visible light and the near-infrared rays are overlapped and irradiated to the same portion at the same time. The following methods may be used: each light source and the CCD camera are arranged, and the liquid crystal panel to which the polarizing plate is attached is moved and sequentially inspected; and any light source and one CCD camera are arranged, and the light source is replaced after the inspection of one light irradiation is completed. The inspection of the other side of the light is carried out. ' Again' as the imaging element of the CCD camera used, it can be a line sensor or a zone sensor. [Embodiment U] The inspection method is shown by way of example, but the invention is not limited to the embodiment. Example 1 153880.doc 201132963 In the same manner as shown in FIG. 1, a light source is disposed under the liquid crystal panel to which the polarizing plate is bonded on both sides, and a camera is disposed on the upper side, and the two sides are attached to the front side of the liquid crystal panel. The liquid crystal panel incorporating the polarizing plate performs defect inspection while moving. When the liquid crystal panel having the polarizing plates bonded to both sides of the polarizing plate is turned upside down, that is, when the television is formed, the inspection is performed from both the front side and the back side. A metal halide lamp and a sensitized lamp were used as a light source, and a CCd camera was used as a camera', and an optical image processing visual inspection device (manufactured by KUB〇TEC Co., Ltd.) was used as a signal processing device. Furthermore, after the inspection of one of the lamps, the illumination of the illumination is replaced by the lamp of the other side, and the inspection of the other illumination is performed. In the liquid crystal panel in which the polarizing plate is bonded to both sides of the inspection object, the separation film of the polarizing plate Sumikalan (registered trademark) (manufactured by Sumitomo Chemical Co., Ltd.) is removed and attached to the liquid crystal panel of the type 37 television. In the signal processing apparatus, in order to cancel the pattern derived from the periodicity of the black matrix, a signal having a periodic pattern corresponding thereto is input in advance, and a signal of the detected periodic pattern is canceled to set a reference line. Set the reference line to 〇, set 32000 gray scales on the white side and black side, and set the 1 〇〇〇 gray scale as the threshold when using the metal halide lamp, and 5 使用 when using the south lamp. The 〇〇 gray scale is set to the threshold value and is a defect when it is above the threshold. An example of detecting defects is shown in Table 1. 153880.doc 201132963 [Table 1]
No. 相機位置 金屬齒化物燈(可見光） 鹵素燈(近紅外镱\ 缺陷形態 模式 灰階峰值 尺寸 模式 灰階峰值 [λ寸 1 表面側 X 黑點 17150 16 背面側白 線狀物 背面側 X - 黑點 16226 9 2 表面側 亮點 32000 73 X • 表面側糊 狀物 背面側 亮點 32000 82 X - - 3 表面側 X - - 黑點 17931 74 背面側氣 泡 背面側 X - - 黑點 19139 63 4 表面側 亮點 32000 551 亮點 30340 105 表面側線 狀PET 背面側 亮點 32000 717 亮點 32000 100 表1中’相機位置表示將液晶面板之哪一面朝向相機配 置而進行檢查。模式表示將缺陷作為黑點或亮點而檢測 出’ X表示黑點亮點皆未檢測出。尺寸係以缺陷之平面圖 像之像素數表示。缺陷形態表示以放大鏡觀察到的缺陷之 狀況。 如上所述’可照射近紅外線而檢測出照射可見光未能檢 測到之缺陷。相反’亦具有可見光可檢測而近红外線無法 檢測之情形。而且，亦具有兩方皆可檢測之情形。 因此’藉由分別進行可見光及近紅外線之檢查而可無遺 漏地檢測出缺陷。 【圖式簡單說明】 圖1係本發明之缺陷檢查裝置之模式圖。 ® 2係模式性表示偏光板於正交偏光狀態時之透光性。 【主要元件符號說明】 1 已貼合偏光板之液晶面板 2 光源 3 相機 4 信號處理裝置 153880.doc •9-No. Camera position Metal toothed lamp (visible light) Halogen lamp (near infrared 镱 \ Defective mode mode Gray scale peak size mode Gray scale peak [λ inch 1 Surface side X black point 17150 16 Back side white line back side X - Black Point 16226 9 2 Surface side bright spot 32000 73 X • Surface side paste back side bright spot 32000 82 X - - 3 Surface side X - - Black point 17931 74 Back side bubble back side X - - Black point 19139 63 4 Surface side bright spot 32000 551 Highlights 30340 105 Surface-side linear PET Back side Highlights 32000 717 Highlights 32000 100 In Table 1, 'camera position indicates which side of the LCD panel is facing the camera for inspection. The mode indicates that the defect is detected as a black or bright spot' X indicates that none of the black lighting points are detected. The size is represented by the number of pixels of the planar image of the defect. The defect form indicates the condition of the defect observed by the magnifying glass. As described above, the visible light can be detected by irradiating near infrared rays. The defect detected. On the contrary, it also has a situation where visible light is detectable and near infrared rays cannot be detected. Moreover, There are cases where both can be detected. Therefore, defects can be detected without missing inspection by visible light and near-infrared light respectively. [Schematic Description] Fig. 1 is a schematic view of the defect inspection device of the present invention. The 2 series mode indicates the light transmittance of the polarizing plate in the direction of the orthogonal polarization. [Description of main components] 1 LCD panel 2 with polarizing plate light source 3 Camera 4 Signal processing device 153880.doc • 9-